The present invention relates to a shock absorber.
　This application claims priority based on Japanese Patent Application No. 2018-241206 filed in Japan on December 25, 2018, the contents of which are incorporated herein by reference.
Background technology
[0002]
　Some shock absorbers have two valves that open in the same stroke arranged in parallel (see, for example, Patent Document 1).
Prior art literature
Patent documents
[0003]
Patent Document 1: Japanese Patent Publication No. 2-4-1666
Outline of the invention
Problems to be solved by the invention
[0004]
　By arranging valves that open in the same stroke in parallel, it is possible to open only one valve in the region where the piston speed is low and to open both valves in the region where the piston speed is higher than this. .. In such a structure, it is particularly required to improve the durability of the valve on the low speed side.
[0005]
　The present invention provides a shock absorber that can improve the durability of the valve.
Means to solve problems
[0006]
　According to one aspect of the present invention, the shock absorber is slidably provided in the cylinder, and the piston that divides the inside of the cylinder into one side chamber and the other side chamber, and the upstream side in the cylinder due to the movement of the piston. The first passage and the second passage through which the working fluid flows from the chamber to the chamber on the downstream side, the first damping force generating mechanism provided in the first passage provided in the piston and generating the damping force, and the other side chamber. A second damping force generation mechanism, which is provided in the annular valve seat member arranged in the above and is provided in the second passage parallel to the first passage to generate a damping force, is provided. The second damping force generation mechanism includes a first sub-valve provided on one side of the second passage provided in the valve seat member, a second sub-valve provided on the other side, and the piston and the valve in the second passage. It is provided with a bottomed tubular cap member provided between the seat member and the seat member. The valve seat member is provided in the cap member. The first sub-valve is provided in the other concubine. The second sub-valve is provided in a cap chamber between the bottom of the cap member and the valve seat member. In the second passage, an orifice is arranged on the upstream side or the downstream side of the flow in which the first sub-valve opens. In the region where the piston speed is low, the second damping force generating mechanism opens while the first damping force generating mechanism is closed. In the speed region where the piston speed is higher than the low speed, both the first damping force generation mechanism and the second damping force generation mechanism open.
The invention's effect
[0007]
　According to the above-mentioned shock absorber, it is possible to improve the durability of the valve.
A brief description of the drawing
[0008]
FIG. 1 is a cross-sectional view showing a shock absorber according to the first embodiment of the present invention.
FIG. 2 is a partial cross-sectional view showing the periphery of the piston of the shock absorber according to the first embodiment of the present invention.
FIG. 3 is a partial cross-sectional view showing the periphery of the orifice of the shock absorber according to the first embodiment of the present invention.
FIG. 4 is a hydraulic circuit diagram of a shock absorber according to the first embodiment of the present invention.
FIG. 5 is a characteristic diagram showing a damping force characteristic in the extension stroke of the shock absorber according to the first embodiment of the present invention.
FIG. 6 is a cross-sectional view showing a main part of a shock absorber according to a second embodiment of the present invention.
FIG. 7 is a cross-sectional view showing a main part of a shock absorber according to a third embodiment of the present invention.
FIG. 8 is a cross-sectional view showing a main part of the shock absorber according to the fourth embodiment of the present invention.
FIG. 9 is a cross-sectional view showing a main part of the shock absorber according to the fifth embodiment of the present invention.
FIG. 10 is a partial cross-sectional view showing the periphery of the orifice of the shock absorber according to the fifth embodiment of the present invention.
FIG. 11 is a cross-sectional view showing a main part of the shock absorber according to the sixth embodiment of the present invention.
FIG. 12 is a partial cross-sectional view showing the periphery of the orifice of the shock absorber according to the sixth embodiment of the present invention.
FIG. 13 is a cross-sectional view showing a main part of the shock absorber according to the seventh embodiment of the present invention.
FIG. 14 is a cross-sectional view showing a main part of the shock absorber according to the eighth embodiment of the present invention.
FIG. 15 is a cross-sectional view showing a main part of the shock absorber according to the ninth embodiment of the present invention.
Embodiment for carrying out the invention
[0009]
[First Embodiment] The first embodiment according to the
　present invention will be described with reference to FIGS. 1 to 5. In the following, for convenience of explanation, the upper side in the drawing will be referred to as “upper” and the lower side in the drawing will be referred to as “lower”.
[0010]
　As shown in FIG. 1, the shock absorber 1 of the first embodiment is a so-called double-cylinder type hydraulic shock absorber. The shock absorber 1 includes a cylinder 2 in which an oil solution (not shown) as a working fluid is sealed. The cylinder 2 has a cylindrical inner cylinder 3 and a bottomed cylindrical outer cylinder 4 having a diameter larger than that of the inner cylinder 3 and provided concentrically so as to cover the inner cylinder 3. A reservoir chamber 6 is formed between the inner cylinder 3 and the outer cylinder 4.
[0011]
　The outer cylinder 4 includes a cylindrical body member 11 and a bottom member 12 that is fitted and fixed to the lower side of the body member 11 to close the lower part of the body member 11. The mounting eye 13 is fixed to the bottom member 12 at an outer position opposite to the body member 11.
[0012]
　The shock absorber 1 includes a piston 18 slidably provided inside the inner cylinder 3 of the cylinder 2. The piston 18 defines two chambers in the inner cylinder 3, an upper chamber 19 (one side chamber) which is one cylinder inner chamber and a lower chamber 20 (the other side chamber) which is the other cylinder inner chamber. ing. In other words, the piston 18 is slidably provided in the cylinder 2 and divides the inside of the cylinder 2 into an upper chamber 19 on one side and a lower chamber 20 on the other side. An oil solution as a working fluid is sealed in the upper chamber 19 and the lower chamber 20 in the inner cylinder 3. An oil liquid and a gas as working fluids are sealed in the reservoir chamber 6 between the inner cylinder 3 and the outer cylinder 4.
[0013]
　The shock absorber 1 includes a piston rod 21 whose one end side portion in the axial direction is arranged inside the inner cylinder 3 of the cylinder 2 and is connected and fixed to the piston 18 and the other end side portion extends to the outside of the cylinder 2. ing. The piston rod 21 penetrates the upper chamber 19 and does not penetrate the lower chamber 20. Therefore, the upper chamber 19 is a rod side chamber through which the piston rod 21 penetrates, and the lower chamber 20 is a bottom side chamber on the bottom side of the cylinder 2.
[0014]
　The piston 18 and the piston rod 21 move integrally. The piston 18 moves toward the upper chamber 19 in the extension stroke of the shock absorber 1 in which the piston rod 21 increases the amount of protrusion from the cylinder 2. The piston 18 moves toward the lower chamber 20 in the contraction stroke of the shock absorber 1 in which the piston rod 21 reduces the amount of protrusion from the cylinder 2.
[0015]
　A rod guide 22 is fitted on the upper end opening side of the inner cylinder 3 and the outer cylinder 4. A seal member 23 is fitted in the outer cylinder 4 on the upper side, which is the outer side of the cylinder 2 with respect to the rod guide 22. Both the rod guide 22 and the seal member 23 have an annular shape. The piston rod 21 is slidably inserted inside each of the rod guide 22 and the seal member 23, and extends from the inside of the cylinder 2 to the outside. One end side portion of the piston rod 21 in the axial direction is fixed to the piston 18 inside the cylinder 2, and the other end side portion protrudes to the outside of the cylinder 2 via the rod guide 22 and the seal member 23.
[0016]
　The rod guide 22 supports the piston rod 21 so as to be movable in the axial direction while restricting its radial movement, and guides the movement of the piston rod 21. The seal member 23 is in close contact with the outer cylinder 4 at its outer peripheral portion, and is in sliding contact with the outer peripheral portion of the piston rod 21 moving in the axial direction at its inner peripheral portion. As a result, the seal member 23 prevents the oil liquid in the inner cylinder 3 and the high-pressure gas and the oil liquid in the reservoir chamber 6 in the outer cylinder 4 from leaking to the outside.
[0017]
　The outer peripheral portion of the rod guide 22 has a stepped shape in which the upper portion has a larger diameter than the lower portion. The rod guide 22 fits into the inner peripheral portion of the upper end of the inner cylinder 3 at the lower portion of the small diameter, and fits into the inner peripheral portion of the upper portion of the outer cylinder 4 at the upper portion of the large diameter. A base valve 25 that defines the lower chamber 20 and the reservoir chamber 6 is installed on the bottom member 12 of the outer cylinder 4. The inner peripheral portion of the lower end of the inner cylinder 3 is fitted to the base valve 25. The upper end portion of the outer cylinder 4 is crimped inward in the radial direction to form a locking portion 26. The locking portion 26 and the rod guide 22 sandwich the seal member 23.
[0018]
　The piston rod 21 has a spindle portion 27 and a mounting shaft portion 28 having a smaller diameter than the spindle portion 27. In the piston rod 21, the spindle portion 27 is slidably fitted to the rod guide 22 and the seal member 23, and the mounting shaft portion 28 is arranged in the cylinder 2 and connected to the piston 18 and the like. The end portion of the spindle portion 27 on the mounting shaft portion 28 side is a shaft step portion 29 extending in the direction orthogonal to the axis. A pair of passage notches 30 extending in the axial direction are formed on the outer peripheral portion of the mounting shaft portion 28 at an intermediate position in the axial direction, and a male screw 31 is formed at the tip position on the opposite side of the main shaft portion 27 in the axial direction. Is formed. The passage cutout portion 30 has a so-called two-sided width shape formed by cutting out two positions of the mounting shaft portion 28, which differ by 180 degrees in the circumferential direction, in parallel in a plane.
[0019]
　In the shock absorber 1, for example, the protruding portion of the piston rod 21 from the cylinder 2 is arranged at the upper part and supported by the vehicle body, and the mounting eye 13 on the cylinder 2 side is arranged at the lower part and connected to the wheel side. On the contrary, the cylinder 2 side may be supported by the vehicle body and the piston rod 21 may be connected to the wheel side.
[0020]
　As shown in FIG. 2, the piston 18 is a composite of a metal piston body 35 connected to the piston rod 21 and an annular shape that is integrally mounted on the outer peripheral surface of the piston body 35 and slides in the inner cylinder 3. It is composed of a sliding member 36 made of resin.
[0021]
　The piston body 35 can communicate with a plurality of passage holes 37 capable of communicating the upper chamber 19 and the lower chamber 20 (only one place is shown in FIG. 2 due to the cross section), and the upper chamber 19 and the lower chamber 20 can communicate with each other. There are a plurality of passage holes 39 (only one is shown in FIG. 2 because of the cross section). The piston body 35 is a sintered product, and the passage holes 37 and 39 are formed during sintering. Alternatively, it is formed by cutting with a drill.
[0022]
　The plurality of passage holes 37 are formed at equal pitches with one passage hole 39 sandwiched between them in the circumferential direction of the piston body 35, and form half of the passage holes 37 and 39. The plurality of passage holes 37 have a crank shape having two bending points. In the plurality of passage holes 37, one side in the axial direction of the piston 18 (upper side in FIG. 2) is outside in the radial direction of the piston 18, and the other side in the axial direction of the piston 18 (lower side in FIG. 2) is a piston rather than one side. It is open inward in the radial direction of 18.
[0023]
　On the lower chamber 20 side of the passage hole 37, a first damping force generation mechanism 41 for opening and closing the passage in the passage hole 37 to generate a damping force is provided. By arranging the first damping force generation mechanism 41 on the lower chamber 20 side, the passages in the plurality of passage holes 37 move to the upper chamber 19 side of the piston 18, that is, the upper chamber on the upstream side in the extension stroke. It is a passage on the extension side where the oil liquid flows out from 19 toward the lower chamber 20 on the downstream side. The first damping force generation mechanism 41 provided for the passage in the passage hole 37 suppresses the flow of the oil liquid from the passage in the passage hole 37 on the extension side to the lower chamber 20 to generate the damping force. It is a damping force generation mechanism on the extension side.
[0024]
　The passage holes 39 constituting the other half of the passage holes 37 and 39 are formed at equal pitches with one passage hole 37 sandwiched between them in the circumferential direction of the piston main body 35.
　The plurality of passage holes 39 have a crank shape having two bending points. In the plurality of passage holes 39, the other side in the axial direction of the piston 18 (lower side in FIG. 2) is outside in the radial direction of the piston 18, and one side in the axial direction of the piston 18 (upper side in FIG. 2) is the piston than the other side. It is open inward in the radial direction of 18.
[0025]
　On the upper chamber 19 side of the passage hole 39, a first damping force generation mechanism 42 for opening and closing the passage in the passage hole 39 to generate a damping force is provided. By arranging the first damping force generation mechanism 42 on the upper chamber 19 side, the passages in the plurality of passage holes 39 move to the lower chamber 20 side of the piston 18, that is, the lower chamber on the upstream side in the contraction stroke. It is a passage on the contraction side where the oil liquid flows from the 20 toward the upper chamber 19 on the downstream side. The first damping force generating mechanism 42 provided for the passage in the passage hole 39 suppresses the flow of the oil liquid from the passage in the passage hole 39 on the contraction side to the upper chamber 19 to generate the damping force. It is a damping force generation mechanism on the contraction side.
[0026]
　The piston body 35 has a substantially disk shape. At the center of the piston body 35 in the radial direction, an insertion hole 44 into which the mounting shaft portion 28 of the piston rod 21 is inserted is formed so as to penetrate in the axial direction. The insertion hole 44 has a small diameter hole portion 45 on one side in the axial direction for fitting the mounting shaft portion 28 of the piston rod 21, and a large diameter hole portion 46 on the other side in the axial direction having a larger diameter than the small diameter hole portion 45. doing.
[0027]
　At the end of the piston body 35 on the lower chamber 20 side in the axial direction, an annular inner seat portion 47 is formed inside the piston body 35 in the radial direction from the opening on the lower chamber 20 side of the passage hole 37. There is. At the end of the piston body 35 on the lower chamber 20 side in the axial direction, a part of the first damping force generating mechanism 41 is located outside the piston body 35 in the radial direction from the opening on the lower chamber 20 side of the passage hole 37. The annular valve seat portion 48 constituting the above is formed.
[0028]
　At the end of the piston body 35 on the upper chamber 19 side in the axial direction, an annular inner sheet portion 49 is formed inside the piston body 35 in the radial direction from the opening on the upper chamber 19 side of the passage hole 39. .. At the end of the piston body 35 on the upper chamber 19 side in the axial direction, a part of the first damping force generating mechanism 42 is located outside the piston body 35 in the radial direction from the opening on the upper chamber 19 side of the passage hole 39. The annular valve seat portion 50 constituting the above is formed.
[0029]
　The insertion hole 44 of the piston body 35 is provided with a large-diameter hole portion 46 on the inner sheet portion 47 side in the axial direction with respect to the small-diameter hole portion 45. The passage in the large-diameter hole portion 46 of the piston body 35 is always in communication with the passage in the passage notch 30 of the piston rod 21.
[0030]
　In the piston body 35, the radial outer side of the valve seat portion 48 has a stepped shape having a lower axial height than the valve seat portion 48. An opening on the lower chamber 20 side of the passage hole 39 on the contraction side is arranged in this stepped portion. Similarly, in the piston main body 35, the radial outer side of the valve seat portion 50 has a stepped shape having a lower axial height than the valve seat portion 50. An opening on the upper chamber 19 side of the passage hole 37 on the extension side is arranged in this stepped portion.
[0031]
　The first damping force generating mechanism 42 on the contraction side includes the valve seat portion 50 of the piston 18, and one disk 62 and a plurality of discs having the same inner diameter and the same outer diameter (in order from the piston 18 side in the axial direction). Specifically, four discs 63), a plurality of discs 64 (specifically, two discs) having the same inner diameter and the same outer diameter, one disc 65, one disc 66, and one disc. It has an annular member 67 of the above. The discs 62 to 66 and the annular member 67 are made of metal. The discs 62 to 66 and the annular member 67 each have a perforated circular flat plate shape having a constant thickness to which the mounting shaft portion 28 of the piston rod 21 can be fitted inside.
[0032]
　The disk 62 has an outer diameter larger than the outer diameter of the inner seat portion 49 of the piston 18 and smaller than the inner diameter of the valve seat portion 50. The disk 62 is always in contact with the inner sheet portion 49. The plurality of discs 63 have an outer diameter substantially equal to the outer diameter of the valve seat portion 50 of the piston 18. The plurality of discs 63 can be seated on the valve seat portion 50.
[0033]
　The plurality of discs 64 have an outer diameter smaller than the outer diameter of the disc 63. The disc 65 has an outer diameter smaller than the outer diameter of the disc 64 and a smaller diameter than the outer diameter of the inner seat portion 49 of the piston 18. The disc 66 has an outer diameter larger than the outer diameter of the disc 64 and a smaller diameter than the outer diameter of the disc 63. The annular member 67 has an outer diameter smaller than the outer diameter of the disc 66 and a larger diameter than the outer diameter of the shaft step portion 29 of the piston rod 21. The annular member 67 is thicker and more rigid than the discs 62 to 66. The annular member 67 is in contact with the shaft step portion 29.
[0034]
　A plurality of discs 63 and a plurality of discs 64 form a contraction-side main valve 71 that can be taken off and seated on the valve seat portion 50. By separating the main valve 71 from the valve seat portion 50, the passage in the passage hole 39 is communicated with the upper chamber 19, and the flow of oil liquid between the main valve 71 and the valve seat portion 50 is suppressed to reduce the damping force. appear. The annular member 67, together with the disc 66, regulates the deformation of the main valve 71 in the opening direction beyond the specified value.
[0035]
　The passage between the main valve 71 and the valve seat portion 50 that appears at the time of valve opening and the passage in the passage hole 39 are moved from the lower chamber 20 on the upstream side in the cylinder 2 to the downstream side by the movement of the piston 18. The first passage 72 on the contraction side through which the oil liquid flows into the chamber 19 is configured. The first damping force generation mechanism 42 on the contraction side that generates damping force includes a main valve 71 and a valve seat portion 50. Therefore, the first damping force generation mechanism 42 is provided in the first passage 72. The first passage 72 is provided in the piston 18 including the valve seat portion 50, and the oil liquid passes through when the piston rod 21 and the piston 18 move to the contraction side.
[0036]
　The first damping force generating mechanism 42 on the contraction side allows both the valve seat portion 50 and the main valve 71 in contact with the valve seat portion 50 to communicate the upper chamber 19 and the lower chamber 20 even when they are in contact with each other. No fixed orifice is formed. That is, the first damping force generation mechanism 42 on the contraction side does not allow the upper chamber 19 and the lower chamber 20 to communicate with each other if the valve seat portion 50 and the main valve 71 are in contact with each other over the entire circumference. In other words, the first passage 72 does not form a fixed orifice that always communicates the upper chamber 19 and the lower chamber 20, and is not a passage that always communicates the upper chamber 19 and the lower chamber 20.
[0037]
　The first damping force generating mechanism 41 on the extension side includes the valve seat portion 48 of the piston 18, and one disk 82 and a plurality of discs having the same inner diameter and the same outer diameter (in order from the piston 18 side in the axial direction). Specifically, it has five discs 83), one disc 84, and one disc 85. The disks 82 to 85 are made of metal. The discs 82 to 85 each have a perforated circular flat plate shape having a constant thickness to which the mounting shaft portion 28 of the piston rod 21 can be fitted.
[0038]
　The disk 82 has an outer diameter larger than the outer diameter of the inner seat portion 47 of the piston 18 and smaller than the inner diameter of the valve seat portion 48. The disk 82 is always in contact with the inner sheet portion 47. As shown in FIG. 3, the disk 82 has a notch 88 that allows the passage in the passage hole 37 to always communicate with the passage in the large-diameter hole portion 46 of the piston 18 and the passage in the passage notch 30 of the piston rod 21. However, it is formed from an intermediate position on the outer peripheral edge side in the radial direction to the inner peripheral edge portion.
[0039]
　As shown in FIG. 2, the plurality of discs 83 have an outer diameter substantially equal to the outer diameter of the valve seat portion 48 of the piston 18, and can be seated on the valve seat portion 48. The disk 84 has an outer diameter smaller than the outer diameter of the disk 83 and smaller than the outer diameter of the inner seat portion 47 of the piston 18. The disc 85 has an outer diameter larger than the outer diameter of the disc 84 and a smaller diameter than the outer diameter of the disc 83.
[0040]
　A plurality of discs 83 constitute a main valve 91 on the extension side that can be taken off and seated on the valve seat portion 48. By separating the main valve 91 from the valve seat portion 48, the passage in the passage hole 37 is communicated with the lower chamber 20, and the flow of oil liquid between the main valve 91 and the valve seat portion 48 is suppressed to reduce the damping force. appear.
[0041]
　The passage between the main valve 91 and the valve seat portion 48 that appears at the time of valve opening and the passage in the passage hole 37 become the lower side from the upper chamber 19 which is the upstream side in the cylinder 2 due to the movement of the piston 18. The first passage 92 on the extension side from which the oil liquid flows out to the chamber 20 is configured. The extension-side first damping force generation mechanism 41 that generates a damping force includes a main valve 91 and a valve seat portion 48. Therefore, the first damping force generation mechanism 41 is provided in the first passage 92. The first passage 92 is provided in the piston 18 including the valve seat portion 48, and the oil liquid passes through when the piston rod 21 and the piston 18 move to the extension side.
[0042]
　The first damping force generation mechanism 41 on the extension side communicates the upper chamber 19 and the lower chamber 20 with both the valve seat portion 48 and the main valve 91 in contact with the valve seat portion 48 even when they are in contact with each other. No fixed orifice is formed. That is, the first damping force generating mechanism 41 on the extension side does not allow the upper chamber 19 and the lower chamber 20 to communicate with each other if the valve seat portion 48 and the main valve 91 are in contact with each other over the entire circumference. In other words, the first passage 92 is not formed with a fixed orifice that always communicates the upper chamber 19 and the lower chamber 20, and is not a passage that always communicates the upper chamber 19 and the lower chamber 20.
[0043]
　On the side opposite to the piston 18 of the first damping force generating mechanism 41 on the extension side, one cap member 101, one passage forming member 102, and one piece in order from the first damping force generating mechanism 41 side. A disc 103, a single disc 104, a plurality of discs 105 having the same inner diameter and the same outer diameter (specifically, two discs), and a valve seat member provided with one O-ring 107 on the outer peripheral side. 106, a plurality of discs 108 having the same inner diameter and the same outer diameter (specifically, three discs), and a plurality of discs 109 having the same inner diameter and the same outer diameter (specifically, two discs), and one disc. The disk 110 and one annular member 111 are provided by fitting the mounting shaft portion 28 of the piston rod 21 inside each of them. A male screw 31 is formed on the mounting shaft portion 28 of the piston rod 21 at a portion protruding from the annular member 111 on the side opposite to the piston 18. A nut 112 is screwed into the male screw 31. The nut 112 is in contact with the annular member 111.
[0044]
　The cap member 101, the passage forming member 102, the discs 103 to 105, the valve seat member 106, the discs 108 to 110, and the annular member 111 are all made of metal. The discs 103 to 105, 108 to 110 and the annular member 111 all have a perforated circular flat plate shape having a constant thickness to which the mounting shaft portion 28 of the piston rod 21 can be fitted inside. The cap member 101, the passage forming member 102, and the valve seat member 106 each form an annular shape in which the mounting shaft portion 28 of the piston rod 21 can be fitted.
[0045]
　The cap member 101 is a bottomed tubular integrally molded product. The cap member 101 is formed by drawing a metal plate. The cap member 101 has a perforated disk-shaped bottom portion 122, an intermediate tapered portion 123 extending from the outer peripheral edge portion of the bottom portion 122 while expanding in diameter in one axial direction of the bottom portion 122, and a bottom portion of the intermediate tapered portion 123. A cylindrical tubular portion 124 extending in the direction opposite to the bottom 122 from the edge portion on the opposite side of the 122, and an intermediate tapered portion from the end edge portion on the opposite side of the intermediate tapered portion 123 of the tubular portion 124. It has an opening diameter expansion portion 125 that extends while expanding the diameter in the direction opposite to that of 123. The cap member 101 is arranged so that the bottom portion 122 faces the piston 18 side. The cap member 101 is fitted to the mounting shaft portion 28 at the inner peripheral portion of the bottom portion 122.
[0046]
　The cap member 101 has a substantially constant thickness, and the outer diameter of the bottom portion 122 is equivalent to the outer diameter of the disk 83 constituting the main valve 91. The cap member 101 is thicker than the disc 83 and has a bottomed tubular shape, and has higher rigidity than the disc 83. Therefore, the cap member 101 is restricted from being deformed in the opening direction of the main valve 91 composed of a plurality of discs 83 by the disc 85 in contact with the cap member 101.
[0047]
　The valve seat member 106 has a perforated disk-shaped main body 132 in which the through hole 131 is formed in the center in the radial direction. The through hole 131 penetrates the main body 132 in the thickness direction. The mounting shaft portion 28 is inserted into the through hole 131. The valve seat member 106 has an inner seat portion 134, an intermediate valve seat portion 135, and an outer valve seat portion 136 in order from the inside in the radial direction of the main body portion 132 on one side in the axial direction of the main body portion 132 in the axial direction of the main body portion 132. On the other side, an inner seat portion 138 and a valve seat portion 139 are provided in order from the inner side in the radial direction of the main body portion 132, respectively.
[0048]
　The inner sheet portion 134 has an annular shape and projects from the inner peripheral edge portion of the main body portion 132 to one side along the axial direction of the main body portion 132. The intermediate valve seat portion 135 also has an annular shape, and protrudes from an intermediate position in the radial direction of the main body portion 132 to the same side as the inner seat portion 134 along the axial direction of the main body portion 132. The outer valve seat portion 136 also has an annular shape, and protrudes from the radial outer peripheral side of the main body portion 132 to the same side as the inner seat portion 134 along the axial direction of the main body portion 132.
[0049]
　The inner sheet portion 138 also has an annular shape, and protrudes from the inner peripheral edge portion of the main body portion 132 to the side opposite to the inner sheet portion 134 along the axial direction of the main body portion 132. The inner sheet portions 134 and 138 both have through holes 131 on the inner side in the radial direction and have the same outer diameter. The valve seat portion 139 also has an annular shape, and protrudes from an intermediate position in the radial direction of the main body portion 132 to the same side as the inner seat portion 138 along the axial direction of the main body portion 132. The intermediate valve seat portion 135 and the valve seat portion 139 have the same inner diameter and the same outer diameter.
[0050]
　The main body portion 132 is formed with an inner passage hole 141 that penetrates the main body portion 132 in the axial direction between the inner seat portions 134 and 138 and the intermediate valve seat portion 135 and the valve seat portion 139. A plurality of inner passage holes 141 are formed at equal intervals in the circumferential direction of the main body portion 132. The main body 132 has an outer passage hole 143 between the intermediate valve seat 135 and the outer valve seat 136, which is radially outside the valve seat 139 and penetrates the main body 132 in the axial direction. Has been done. The outer passage hole 143 is arranged outside the inner passage hole 141 in the radial direction of the main body portion 132. A plurality of outer passage holes 143 are formed at equal intervals in the circumferential direction of the main body portion 132.
[0051]
　The main body portion 132 is formed with an annular seal groove 145 that is recessed inward in the radial direction at an axially intermediate position on the outer peripheral portion. An O-ring 107 is arranged in the seal groove 145. The valve seat member 106 is fitted to the tubular portion 124 of the cap member 101 in the main body portion 132 with the inner seat portion 134, the intermediate valve seat portion 135, and the outer valve seat portion 136 facing toward the bottom portion 122. There is. Therefore, the valve seat member 106 is provided in the cap member 101. In this state, the O-ring 107 seals the gap between the tubular portion 124 of the cap member 101 and the main portion 132 of the valve seat member 106. The valve seat member 106 is fitted to the mounting shaft portion 28 in the through hole 131.
[0052]
　The cap member 101, the valve seat member 106, and the O-ring 107 form a housing 147 that forms a cap chamber 146 inside. The cap chamber 146 is provided between the bottom 122 of the cap member 101 and the valve seat member 106 in the housing 147. The passage forming member 102, the disc 103, the disc 104, and the plurality of discs 105 are provided in the cap chamber 146. In the valve seat member 106, the intermediate valve seat portion 135 and the outer valve seat portion 136 are arranged on the cap chamber 146 side, and the valve seat portion 139 is arranged on the lower chamber 20 side. The housing 147 is arranged in the lower chamber 20 including the annular valve seat member 106. The valve seat member 106 divides the cap chamber 146 and the lower chamber 20, and is provided facing both the cap chamber 146 and the lower chamber 20.
[0053]
　The passage forming member 102 has an outer diameter smaller than the outer diameter of the bottom portion 122 of the cap member 101. At the center of the passage forming member 102 in the radial direction, a small diameter fitting hole 151 is formed on one side in the axial direction, and a large diameter hole 152 having a diameter larger than that of the small diameter fitting hole 151 is formed on the other side in the axial direction. There is. The passage forming member 102 is formed with a passage groove 153 that penetrates in the radial direction from the large diameter hole 152 to the outer peripheral surface on the side of the large diameter hole 152 in the axial direction. A plurality of passage grooves 153 are provided side by side at equal intervals in the circumferential direction of the passage forming member 102. The passage forming member 102 is formed in such a shape from one member by, for example, cutting. The passage forming member 102 is arranged so that the large diameter hole 152 and the passage groove 153 face the bottom 122 side. The passage forming member 102 is fitted to the mounting shaft portion 28 in the small diameter fitting hole 151. In the passage forming member 102, the passage in the large diameter hole 152 is always in communication with the passage in the passage notch 30 of the piston rod 21.
[0054]
　The passage in the large-diameter hole 152 of the passage forming member 102 and the passage in the passage groove 153 are always connected to the cap chamber 146 and the passage in the passage notch 30 of the piston rod 21. Therefore, the cap chamber 146 has a passage in the large-diameter hole 152 of the passage forming member 102, a passage in the passage groove 153, a passage in the passage notch 30 of the piston rod 21, and a passage in the large-diameter hole 46 of the piston 18. , The passage in the notch 88 of the disk 82, and the passage in the passage hole 37 of the piston 18 are always connected to the upper chamber 19.
[0055]
　The plurality of discs 105 have an outer diameter substantially equal to the outer diameter of the outer valve seat portion 136 of the valve seat member 106. The plurality of discs 105 are always in contact with the inner seat portion 134 and can be seated on the outer valve seat portion 136 and the intermediate valve seat portion 135. The plurality of discs 105 are formed with through holes 161 penetrating in the axial direction at intermediate positions in the radial direction between the inner seat portion 134 and the intermediate valve seat portion 135, respectively. As for the passage in the through hole 161, the passage in the inner passage hole 141 of the valve seat member 106 is always communicated with the cap chamber 146.
[0056]
　The disk 104 has an outer diameter smaller than the outer diameter of the disk 105 and the outer diameter of the passage forming member 102, and is substantially the same as the outer diameter of the inner seat portion 134 of the valve seat member 106. The disk 103 has an outer diameter larger than the maximum outer diameter of the passage forming member 102 and a smaller diameter than the outer diameter of the disk 105.
[0057]
　The plurality of discs 105 constitute a sub-valve 171 (second sub-valve) that can be taken off and seated on the outer valve seat portion 136 and the intermediate valve seat portion 135. The sub valve 171 is provided in the cap chamber 146. The sub-valve 171 communicates with the passage in the outer passage hole 143 and the cap chamber 146 by separating from the outer valve seat portion 136 in the cap chamber 146, and makes the lower chamber 20 a passage in the passage hole 37, that is, the upper part. Communicate with room 19. At this time, the sub valve 171 suppresses the flow of the oil liquid with the outer valve seat portion 136 to generate a damping force. The sub-valve 171 is an inflow valve that opens when the oil liquid flows into the cap chamber 146 from the lower chamber 20 through the passage in the outer passage hole 143. The sub-valve 171 is a check valve that regulates the inflow of oil liquid from the cap chamber 146 to the lower chamber 20 through the passage in the outer passage hole 143.
[0058]
　The passage in the outer passage hole 143, the passage between the sub-valve 171 and the outer valve seat portion 136 appearing at the time of opening the valve, the cap chamber 146, and the passage in the passage groove 153 and the large-diameter hole 152 of the passage forming member 102. The passage in the passage notch 30 of the piston rod 21, the passage in the large-diameter hole 46 of the piston 18, the passage in the notch 88 of the disk 82, and the passage in the passage hole 37 are the piston 18. A second passage 172 is configured in which the oil liquid flows out from the lower chamber 20 on the upstream side in the cylinder 2 to the upper chamber 19 on the downstream side. The second passage 172 is a passage on the contraction side where the oil liquid flows from the lower chamber 20 on the upstream side to the upper chamber 19 on the downstream side in the movement toward the lower chamber 20 side of the piston 18, that is, in the contraction stroke. The second passage 172 includes a passage in the passage notch 30 formed by cutting the piston rod 21. In other words, the second passage 172 is formed by partially cutting out the piston rod 21.
[0059]
　The sub-valve 171, the outer valve seat portion 136, the intermediate valve seat portion 135, the discs 103 and 104, the passage forming member 102, and the cap member 101 constitute a second damping force generation mechanism 173 on the contraction side. .. The second damping force generation mechanism 173 is provided in the second passage 172 on the contraction side. The second damping force generation mechanism 173 opens and closes the second passage 172, suppresses the flow of the oil liquid from the second passage 172 to the upper chamber 19, and generates a damping force. In other words, in the second damping force generation mechanism 173, the outer valve seat portion 136 and the intermediate valve seat portion 135 are provided on the valve seat member 106. The sub-valve 171 constituting the second damping force generation mechanism 173 on the contraction side is a sub-valve on the contraction side.
[0060]
　In the second passage 172, when the second damping force generation mechanism 173 is in the open state, the passage in the notch 88 of the disk 82 becomes the narrowest in the portion where the cross-sectional area of ​​the flow path is fixed, and the second passage is second. It becomes an orifice 175 in the passage 172. The orifice 175 is arranged on the downstream side of the sub valve 171 in which the oil liquid flows in the second passage 172 and the oil liquid flows when the sub valve 171 opens.
[0061]
　The second damping force generation mechanism 173 on the contraction side is provided for both the outer valve seat portion 136, the intermediate valve seat portion 135, and the sub-valve 171 in contact with them, even if they are in contact with the upper chamber 19 and the lower chamber. No fixed orifice is formed to communicate with 20. That is, the second damping force generation mechanism 173 on the contraction side communicates the upper chamber 19 and the lower chamber 20 if the outer valve seat portion 136, the intermediate valve seat portion 135, and the disc 105 are in contact with each other over the entire circumference. I won't let you. In other words, the second passage 172 does not form a fixed orifice that always communicates the upper chamber 19 and the lower chamber 20, and is not a passage that always communicates the upper chamber 19 and the lower chamber 20. The passage forming member 102 is thicker and more rigid than the disc 105 constituting the sub valve 171. The passage forming member 102, together with the disk 103, regulates the deformation of the sub valve 171 in the opening direction beyond the specified value.
[0062]
　The contraction-side second passage 172 that can communicate the upper chamber 19 and the lower chamber 20 is parallel to the first passage 72 that is the contraction-side passage that also allows the upper chamber 19 and the lower chamber 20 to communicate with each other. A first damping force generation mechanism 42 is provided in the first passage 72. A second damping force generation mechanism 173 is provided in the second passage 172. Therefore, the first damping force generation mechanism 42 and the second damping force generation mechanism 173 on the contraction side are arranged in parallel.
[0063]
　The plurality of discs 108 have an outer diameter substantially equal to the outer diameter of the valve seat portion 139 of the valve seat member 106, and are always in contact with the inner seat portion 138 so that they can be seated on the valve seat portion 139. .. The disc 108 has a smaller diameter than the outer diameter of the disc 105, and has higher rigidity than the disc 105.
[0064]
　The plurality of discs 109 have a smaller diameter than the outer diameter of the disc 108 and have an outer diameter substantially the same as the outer diameter of the inner seat portion 138 of the valve seat member 106. The disk 110 has an outer diameter larger than the outer diameter of the disk 109 and a smaller diameter than the outer diameter of the disk 108.
　The annular member 111 has an outer diameter larger than the outer diameter of the disc 110 and slightly smaller than the outer diameter of the disc 108, and is thicker and more rigid than the disc 108.
[0065]
　The plurality of discs 108 constitute a sub-valve 181 (first sub-valve) that can be taken off and seated on the valve seat portion 139. The sub valve 181 is provided in the lower chamber 20. The sub-valve 181 is separated from the valve seat portion 139 to allow the cap chamber 146 and the lower chamber 20 to communicate with each other via the passage in the through hole 161 of the disc 105 and the passage in the inner passage hole 141. As a result, the sub valve 181 communicates the upper chamber 19 with the lower chamber 20. At this time, the sub-valve 181 suppresses the flow of the oil liquid between the sub-valve 181 and the valve seat portion 139 to generate a damping force. The sub valve 181 is a discharge valve that opens when the oil liquid is discharged from the cap chamber 146 to the lower chamber 20 through the passage in the through hole 161 of the disc 105 and the passage in the inner passage hole 141. The sub-valve 181 is a check valve that regulates the inflow of oil liquid from the lower chamber 20 into the cap chamber 146 through the passage in the inner passage hole 141.
[0066]
　A passage in the passage hole 37 of the piston 18, a passage in the notch 88 of the disk 82, a passage in the large diameter hole 46 of the piston 18, a passage in the passage notch 30 of the piston rod 21, and a passage formation. The passage in the large-diameter hole 152 and the passage groove 153 of the member 102, the cap chamber 146, the passage in the through hole 161 of the disk 105, the passage in the inner passage hole 141, and the sub-valve 181 and the sub-valve 181 appearing at the time of valve opening. The passage between the valve seat portions 139 constitutes a second passage 182 in which the oil liquid flows from the upper chamber 19 on the upstream side in the cylinder 2 to the lower chamber 20 on the downstream side due to the movement of the piston 18. The second passage 182 is a passage on the extension side where the oil liquid flows from the upper chamber 19 on the upstream side to the lower chamber 20 on the downstream side in the movement toward the upper chamber 19 side of the piston 18, that is, in the extension stroke. The second passage 182 includes a passage in the passage notch 30 formed by cutting the piston rod 21. In other words, the second passage 182 is formed by partially cutting out the piston rod 21.
[0067]
　The sub-valve 181 and the valve seat portion 139, a plurality of discs 109, the disc 110, and the annular member 111 constitute a second damping force generation mechanism 183 on the extension side. The second damping force generation mechanism 183 is provided in the second passage 182 on the extension side. The second damping force generation mechanism 183 opens and closes the second passage 182, suppresses the flow of the oil liquid from the second passage 182 to the lower chamber 20, and generates a damping force. In other words, in the second damping force generation mechanism 183, the valve seat portion 139 is provided on the valve seat member 106. The sub-valve 181 constituting the extension-side second damping force generation mechanism 183 is an extension-side sub-valve.
[0068]
　In the second passage 182, when the second damping force generation mechanism 183 is in the open state, the passage in the notch 88 of the disk 82 becomes the narrowest in the portion where the cross-sectional area of ​​the flow path is fixed, and the second passage 182. It also becomes an orifice 175 in the passage 182. The orifice 175 is common to the second passages 172 and 182. The orifice 175 is arranged on the upstream side of the sub valve 181 of the oil liquid flow when the oil liquid flows in the second passage 182 and the sub valve 181 opens. The orifice 175 is formed by cutting out a disk 82 that abuts on the piston 18 of the first damping force generation mechanism 41.
[0069]
　The disc 108 constituting the sub valve 181 has a higher rigidity than the disc 105 constituting the sub valve 171, and the sub valve 181 has a higher rigidity than the sub valve 171. Therefore, the sub-valve 171 which is the inflow valve into the cap chamber 146 has a lower valve opening pressure than the sub-valve 181 which is the discharge valve from the cap chamber 146. The sub-valve 181 and the sub-valve 171 open and close independently.
[0070]
　The second damping force generation mechanism 183 on the extension side communicates the upper chamber 19 and the lower chamber 20 with both the valve seat portion 139 and the disk 108 in contact with the valve seat portion 139 even when they are in contact with each other. Is not formed. That is, the second damping force generation mechanism 183 on the extension side does not allow the upper chamber 19 and the lower chamber 20 to communicate with each other if the valve seat portion 139 and the disk 108 are in contact with each other over the entire circumference. In other words, the second passage 182 is not formed with a fixed orifice that always communicates the upper chamber 19 and the lower chamber 20, and is not a passage that always communicates the upper chamber 19 and the lower chamber 20. The annular member 111, together with the disk 110, regulates the deformation of the sub valve 181 in the opening direction beyond the specified value.
[0071]
　In the shock absorber 1, the upper chamber 19 and the lower chamber 20 have the first damping force generating mechanism 41, 42 and the second damping force generating mechanism 1733 as the flow for passing the oil liquid in the piston 18 in the axial direction at least. Communication is possible only via 183. Therefore, the shock absorber 1 is not provided with a fixed orifice that allows the upper chamber 19 and the lower chamber 20 to always communicate with each other, at least on the passage of the oil liquid that passes in the piston 18 in the axial direction.
[0072]
　The extension-side second passage 182 that can communicate the upper chamber 19 and the lower chamber 20 is the extension-side passage 92 that also allows the upper chamber 19 and the lower chamber 20 to communicate with each other, and the upper chamber 19 side. Except for the passage in the passage hole 37 of the above, the passages are in parallel. In the parallel portion between the second passage 182 and the first passage 92, the first passage 92 is provided with the first damping force generating mechanism 41, and the second passage 182 is provided with the second damping force generating mechanism 183. There is. Therefore, the first damping force generation mechanism 41 and the second damping force generation mechanism 183 on the extension side are arranged in parallel.
[0073]
　The second damping force generation mechanism 173, 183 includes the valve seat member 106, the sub valve 181 provided on one side (lower chamber 20 side) of the second passage 172, 182 provided in the valve seat member 106, and the other side (upper chamber). A sub-valve 171 provided on the 19th side) and a bottomed tubular cap member 101 provided between the piston 18 and the valve seat member 106 in the second passages 172 and 182 are provided. The sub valve 181 is provided on the lower chamber 20 side of the valve seat member 106, and the sub valve 171 is provided in the cap chamber 146 between the bottom portion 122 of the cap member 101 and the valve seat member 106.
[0074]
　As shown in FIG. 1, the above-mentioned base valve 25 is provided between the bottom member 12 of the outer cylinder 4 and the inner cylinder 3. The base valve 25 includes a base valve member 191 that separates the lower chamber 20 and the reservoir chamber 6, a disk 192 provided on the lower side of the base valve member 191, that is, on the reservoir chamber 6 side, and an upper side, that is, a lower side of the base valve member 191. It has a disc 193 provided on the chamber 20 side, and a mounting pin 194 for mounting the disc 192 and the disc 193 to the base valve member 191.
[0075]
　The base valve member 191 has an annular shape. A mounting pin 194 is inserted through the base valve member 191 at the center in the radial direction. The base valve member 191 has a plurality of passage holes 195 through which oil and liquid can flow between the lower chamber 20 and the reservoir chamber 6, and is below the passage holes 195 on the radial outside of the base valve member 191. A plurality of passage holes 196 capable of flowing an oil liquid are formed between the chamber 20 and the reservoir chamber 6. The disk 192 on the reservoir chamber 6 side allows the flow of oil liquid from the lower chamber 20 to the reservoir chamber 6 through the passage hole 195, while allowing the oil liquid to flow from the reservoir chamber 6 to the lower chamber 20 through the passage hole 195. Suppress the flow. The disk 193 allows the flow of oil liquid from the reservoir chamber 6 to the lower chamber 20 through the passage hole 196, while suppressing the flow of the oil liquid from the lower chamber 20 through the passage hole 196 to the reservoir chamber 6.
[0076]
　The disk 192, together with the base valve member 191, constitutes a compression valve mechanism 197 on the contraction side that opens a valve in the contraction stroke of the shock absorber 1 to allow oil and liquid to flow from the lower chamber 20 to the reservoir chamber 6 and generate a damping force. ing. The disk 193 and the base valve member 191 form a suction valve mechanism 198 that opens in the extension stroke of the shock absorber 1 and allows oil liquid to flow from the reservoir chamber 6 into the lower chamber 20. The suction valve mechanism 198 applies oil and liquid from the reservoir chamber 6 to the lower chamber 20 without substantially generating damping force so as to make up for the shortage of the liquid mainly caused by the extension of the piston rod 21 from the cylinder 2. It fulfills the function of flowing.
[0077]
　As shown in FIG. 2, when assembling the piston 18 or the like to the piston rod 21, the annular member 67, the disc 66, the disc 65, and the annular member 67, the disc 66, and the disc 65 are inserted into the shaft step portion 29 while the mounting shaft portion 28 of the piston rod 21 is inserted. A plurality of discs 64, a plurality of discs 63, a disc 62, and a piston 18 are stacked in this order. At this time, the piston 18 is oriented so that the small diameter hole portion 45 faces the shaft step portion 29 side. In addition, the disc 82, a plurality of discs 83, the disc 84, the disc 85, and the cap member 101 are sequentially stacked on the piston 18 while the mounting shaft portion 28 is inserted. At this time, the cap member 101 is oriented so that the opening diameter expanding portion 125 faces the side opposite to the piston 18, and the cap member 101 comes into contact with the disc 85 at the bottom portion 122. Further, the passage forming member 102 is superposed on the bottom portion 122 of the cap member 101 while inserting the mounting shaft portion 28. At this time, the passage forming member 102 is oriented so that the large diameter hole 152 and the passage groove 153 face the bottom 122 side.
[0078]
　In addition, the disc 103, the disc 104, the plurality of discs 105, and the valve seat member 106 in which the O-ring 107 is mounted are superposed on the passage forming member 102 while the mounting shaft portion 28 is inserted. .. At this time, in the valve seat member 106, the inner seat portion 134, the intermediate valve seat portion 135, and the outer valve seat portion 136 are oriented toward the plurality of discs 105, and the main portion 132 and the O-ring 107 are capped with the cap member 101. It is fitted to the tubular portion 124 of. Further, the plurality of discs 108, the plurality of discs 109, the discs 110, and the annular member 111 are superposed on the valve seat member 106 while the mounting shaft portion 28 is inserted. In this state, the nut 112 is screwed into the male screw 31 of the piston rod 21 protruding from the annular member 111, and the nut 112 and the shaft step portion 29 clamp the inner peripheral side thereof in the axial direction.
[0079]
　In this state, the main valve 71 is clamped to the inner seat portion 49 of the piston 18 and the disc 65 via the disc 62 on the inner peripheral side, and abuts on the valve seat portion 50 of the piston 18 over the entire circumference. In this state, the main valve 91 is clamped to the inner seat portion 47 of the piston 18 and the disc 84 via the disc 82 on the inner peripheral side, and abuts on the valve seat portion 48 of the piston 18 over the entire circumference. In this state, the inner peripheral side of the sub-valve 171 is clamped to the inner seat portion 134 and the disk 104 of the valve seat member 106, and the entire circumference of the intermediate valve seat portion 135 and the outer valve seat portion 136 of the valve seat member 106. Abut over. In this state, the sub-valve 181 is clamped to the inner seat portion 138 of the valve seat member 106 and the disk 109 on the inner peripheral side, and abuts on the valve seat portion 139 of the valve seat member 106 over the entire circumference.
[0080] [0080]
　The hydraulic circuit diagram of the shock absorber 1 of the first embodiment is shown in FIG. As shown in FIG. 4, the extension-side first damping force generation mechanism 41 is provided in the extension-side first passage 92 connecting the upper chamber 19 and the lower chamber 20. In parallel with the first damping force generation mechanism 41, a second damping force generation mechanism 183 on the extension side is provided in the second passage 182 on the extension side connecting the upper chamber 19 and the lower chamber 20. A first damping force generation mechanism 42 on the contraction side is provided in the first passage 72 on the contraction side connecting the lower chamber 20 and the upper chamber 19. In parallel with the first damping force generation mechanism 42, a second damping force generation mechanism 173 on the contraction side is provided in the second passage 172 on the contraction side connecting the lower chamber 20 and the upper chamber 19. An orifice 175 is provided at a common portion on the upper chamber 19 side of the second damping force generating mechanism 173 and 183 of the second passages 172 and 182. As described above, the shock absorber 1 is not provided with a fixed orifice that allows the upper chamber 19 and the lower chamber 20 to always communicate with each other.
[0081]
　As shown in FIG. 2, of the extension-side first damping force generation mechanism 41 and the second damping force generation mechanism 183, the main valve 91 of the first damping force generation mechanism 41 is a sub-valve of the second damping force generation mechanism 183. It has higher rigidity and higher valve opening pressure than 181. Therefore, in the extension stroke, in the extremely low speed region where the piston speed is lower than the predetermined value, the second damping force generation mechanism 183 opens with the first damping force generating mechanism 41 closed. In the normal speed region where the piston speed is equal to or higher than this predetermined value, both the first damping force generation mechanism 41 and the second damping force generation mechanism 183 open. The sub-valve 181 is an extremely low-speed valve that opens in a region where the piston speed is extremely low and generates a damping force.
[0082]
　That is, in the extension stroke, the piston 18 moves to the upper chamber 19 side, so that the pressure in the upper chamber 19 increases and the pressure in the lower chamber 20 decreases, but the first damping force generating mechanisms 41, 42 and the second. Since neither of the damping force generation mechanisms 173 and 183 has a fixed orifice, the oil liquid does not flow until the second damping force generation mechanism 183 is opened. Therefore, as shown in FIG. 5, the damping force (DF) rises sharply in the extension stroke when the piston speed (PS) is less than the first predetermined value v1. The piston speed (PS) is a region faster than the first predetermined value v1 opened by the second damping force generation mechanism 183, and is slower than the second predetermined value v2 faster than the first predetermined value v1. In the extremely low speed region (v1 or more and less than v2), the second damping force generation mechanism 183 opens with the first damping force generation mechanism 41 closed.
[0083]
　That is, the sub-valve 181 is separated from the valve seat portion 139, and the upper chamber 19 and the lower chamber 20 are communicated with each other by the second passage 182 on the extension side. Therefore, the oil liquid in the upper chamber 19 enters the passage in the passage hole 37 of the piston 18, the orifice 175, the passage in the large diameter hole portion 46 of the piston 18, and the passage in the passage notch 30 of the piston rod 21. , The passage in the large diameter hole 152 and the passage groove 153 of the passage forming member 102, the cap chamber 146, the passage in the through hole 161 of the sub valve 171, the passage in the inner passage hole 141, the sub valve 181 and the valve seat portion. It flows to the lower chamber 20 through the passage between 139. As a result, even in an extremely low speed region (v1 or more and less than v2) in which the piston speed (PS) is lower than the second predetermined value v2, the damping force of the valve characteristic (the characteristic in which the damping force is substantially proportional to the piston speed) can be obtained.
[0084]
　In the extension stroke, in the normal speed region where the piston speed is the second predetermined value v2 or more, the first damping force generating mechanism 41 opens while the second damping force generating mechanism 183 remains open. That is, the sub-valve 181 is separated from the valve seat portion 139, and the oil liquid flows from the upper chamber 19 to the lower chamber 20 in the second passage 182 on the extension side. At this time, in the second passage 182, the flow of the oil liquid is throttled by the orifice 175 provided on the downstream side of the main valve 91, so that the pressure applied to the main valve 91 increases and the differential pressure increases, so that the main valve 91 Is separated from the valve seat portion 48, and the oil liquid flows from the upper chamber 19 to the lower chamber 20 in the first passage 92 on the extension side. Therefore, the oil liquid in the upper chamber 19 flows to the lower chamber 20 via the passage in the passage hole 37 and the passage between the main valve 91 and the valve seat portion 48.
[0085]
　Here, in the extension stroke, in the normal speed region where the piston speed (PS) is the second predetermined value v2 or more, the differential pressure between the upper chamber 19 and the lower chamber 20 is the first predetermined value v1 or more and less than the second predetermined value v2. However, since the first passage 92 does not have a throttle due to the orifice, the oil liquid can be flowed through the first passage 92 at a large flow rate by opening the main valve 91. By this and by narrowing the second passage 182 with the orifice 175, the deformation of the sub valve 181 can be suppressed.
[0086]
　At this time, pressure in opposite directions is applied to the closed sub-valve 171 from the lower chamber 20 and the cap chamber 146. Even if the differential pressure between the upper chamber 19 and the lower chamber 20 becomes large, the pressure increase of the cap chamber 146 causes the pressure of the upper chamber 19 because the orifice 175 is formed on the upstream side of the sub valve 171 in the second passage 182. It becomes gentle with respect to the rise, and suppresses the increase in the pressure difference between the cap chamber 146 and the lower chamber 20. Therefore, it is possible to suppress a large pressure difference between the cap chamber 146 and the lower chamber 20 received by the closed sub-valve 171 and to apply a large back pressure from the cap chamber 146 side to the lower chamber 20 side to the sub-valve 171. Can be suppressed.
[0087]
　The shock absorber 1 is provided with a flow path for flowing oil liquid from the upper chamber 19 to the lower chamber 20 in parallel in the extension stroke of the first passage 92 and the second passage 182, and the main valve 91 and the sub valve 181 are provided in parallel. There is. The orifice 175 is connected in series with the sub valve 181.
[0088]
　As described above, in the normal speed region where the piston speed (PS) is the second predetermined value v2 or more in the extension stroke, the main valve 91 opens to allow the oil liquid to flow at a large flow rate through the first passage 92. be able to. As a result, the flow rate flowing through the passage between the sub valve 181 and the valve seat portion 139 is reduced. Therefore, the valve rigidity of the sub valve 181 can be reduced.
　Therefore, for example, as shown in FIG. 5, the rate of increase in the damping force (DF) with respect to the increase in the piston speed in the normal speed region (v2 or higher) is reduced from the broken line X1 to the solid line X2. You can do things. In other words, the slope of the increase rate of the damping force (DF) on the extension side with respect to the increase in the piston speed (PS) in the normal speed region (v2 or more) can be laid down more than in the extremely low speed region (less than v2). As a result, the degree of freedom in design can be expanded.
[0089]
　Of the first damping force generation mechanism 42 and the second damping force generation mechanism 173 on the contraction side, the main valve 71 of the first damping force generation mechanism 42 is more rigid than the sub valve 171 of the second damping force generation mechanism 173. High valve opening pressure. Therefore, in the contraction stroke, the second damping force generation mechanism 173 opens with the first damping force generating mechanism 42 closed in the extremely low speed region where the piston speed is lower than the predetermined value. In the normal speed region where the piston speed is equal to or higher than this predetermined value, both the first damping force generation mechanism 42 and the second damping force generation mechanism 173 open. The sub valve 171 is an extremely low speed valve that opens in a region where the piston speed is extremely low and generates a damping force.
[0090]
　That is, in the contraction stroke, the piston 18 moves to the lower chamber 20 side, so that the pressure in the lower chamber 20 increases and the pressure in the upper chamber 19 decreases. However, since neither the first damping force generating mechanism 41, 42 nor the second damping force generating mechanism 173, 183 has a fixed orifice, the oil liquid does not flow until the second damping force generating mechanism 173 is opened. Therefore, the damping force rises sharply. In the region where the piston speed is higher than the third predetermined value at which the second damping force generation mechanism 173 opens, and in the extremely low speed region where the piston speed is faster than the third predetermined value and lower than the fourth predetermined value. The second damping force generation mechanism 173 opens with the first damping force generation mechanism 42 closed.
[0091]
　That is, the sub-valve 171 is separated from the outer valve seat portion 136, and the lower chamber 20 and the upper chamber 19 are communicated with each other in the second passage 172 on the contraction side. Therefore, the oil liquid in the lower chamber 20 contains the passage in the outer passage hole 143, the passage between the sub valve 171 and the outer valve seat portion 136, the cap chamber 146, the passage groove 153 of the passage forming member 102, and the large-diameter hole. Above through the passage in 152, the passage in the passage cutout 30 of the piston rod 21, the passage in the large diameter hole 46 of the piston 18, the orifice 175, and the passage in the passage hole 37 of the piston 18. It flows into the room 19. As a result, the damping force of the valve characteristic (the characteristic in which the damping force is substantially proportional to the piston speed) can be obtained even in the extremely low speed region where the piston speed is lower than the fourth predetermined value.
[0092]
　In the contraction stroke, in the normal speed region where the piston speed is equal to or higher than the fourth predetermined value, the first damping force generating mechanism 42 opens while the second damping force generating mechanism 173 remains open. That is, the sub-valve 171 is separated from the outer valve seat portion 136, and the oil liquid flows from the lower chamber 20 to the upper chamber 19 in the second passage 172 on the contraction side. At this time, since the flow rate of the oil liquid is throttled by the orifice 175 in the second passage 172, the differential pressure generated in the main valve 71 becomes large, the main valve 71 is separated from the valve seat portion 50, and the contraction side. The oil liquid is flowed from the lower chamber 20 to the upper chamber 19 in the first passage 72 of the above. Therefore, the oil liquid in the lower chamber 20 flows through the passage in the passage hole 39 and the passage between the main valve 71 and the valve seat portion 50. As a result, a damping force having valve characteristics (damping force is substantially proportional to the piston speed) can be obtained even in a normal speed region in which the piston speed is equal to or higher than the fourth predetermined value. The rate of increase in the damping force on the contraction side with respect to the increase in the piston speed in the normal speed region is lower than the rate of increase in the damping force on the contraction side with respect to the increase in the piston speed in the extremely low speed region. In other words, the slope of the rate of increase in the damping force on the contraction side with respect to the increase in piston speed in the normal speed region can be laid down more than in the extremely low speed region.
[0093]
　In the contraction stroke, in the normal speed region where the piston speed is equal to or higher than the fourth predetermined value, the differential pressure between the lower chamber 20 and the upper chamber 19 becomes larger than in the low speed region. However, since the first passage 72 is not throttled by the orifice, the oil liquid can flow through the first passage 72 at a large flow rate by opening the main valve 71. As a result, the flow rate flowing through the sub valve 171 becomes small, so that the valve rigidity of the sub valve 171 can be reduced. Therefore, the piston speed can reduce the damping force in the normal speed region, and the degree of freedom in design can be expanded.
[0094]
　When the piston speed is high, the differential pressure between the lower chamber 20 and the upper chamber 19 becomes large, but by narrowing the second passage 172 with the orifice 175, the inside of the cap chamber 146 communicating with the upper chamber 19 via the orifice 175. The pressure is the pressure between the lower chamber 20 and the upper chamber 19. Therefore, it is possible to prevent the differential pressure between the lower chamber 20 and the upper chamber 19 from becoming too large. By opening the main valve 71 and allowing the oil liquid to flow at a large flow rate through the first passage 72, deformation of the sub valve 171 can be suppressed.
[0095]
　Pressure is applied to the closed sub-valve 181 from the lower chamber 20 and the cap chamber 146 in opposite directions. At this time, although the differential pressure between the lower chamber 20 and the upper chamber 19 is large, the lower chamber 20 and the cap chamber 146 communicate with each other by opening the sub valve 171 with the cap chamber 146 on the downstream side of the sub valve 181. An orifice 175 is provided between the upper chamber 19 and the upper chamber 19. Therefore, it is possible to prevent the pressure in the cap chamber 146 from dropping too much, and it is possible to raise the pressure in the cap chamber 146 in accordance with the pressure rise in the lower chamber 20. Therefore, the differential pressure generated on the upstream side and downstream side surfaces of the sub valve 181 is small, and it is possible to suppress the application of a large back pressure from the lower chamber 20 side to the cap chamber 146 side to the sub valve 181.
[0096]
　In the above shock absorber 1, a flow path for flowing oil liquid from the lower chamber 20 to the upper chamber 19 is provided in parallel between the first passage 72 and the second passage 172 in the contraction stroke, and the main valve 71 and the sub valve 171 are arranged in parallel. It is provided. The orifice 175 is connected in series with the sub valve 171 in the second passage 172.
[0097]
　In the contraction stroke, the damping force characteristic by the damping valve mechanism 197 is also combined.
[0098]
　In the extension stroke, the differential pressure between the upper chamber 19 and the lower chamber 20 becomes large in the normal speed region where the piston speed is equal to or higher than the second predetermined value. Since the pressure rise can be suppressed, the deformation of the sub valve 171 due to the back pressure can be suppressed. In the contraction stroke, the differential pressure between the lower chamber 20 and the upper chamber 19 is larger in the normal speed region where the piston speed is equal to or higher than the fourth predetermined value, but the oil liquid is flowed in a large flow rate in the first passage 72. And, by narrowing the downstream side of the second passage 172 from the sub valve 171 with the orifice 175, the deformation of the sub valve 171 can be suppressed. Therefore, the durability of the sub valve 171 can be improved.
[0099]
　In the extension stroke, the differential pressure between the upper chamber 19 and the lower chamber 20 is larger in the normal speed region where the piston speed is equal to or higher than the second predetermined value, but the oil liquid is flowed in a large flow rate in the first passage 92. By narrowing the second passage 182 with the orifice 175, the deformation of the sub valve 181 can be suppressed. In the contraction stroke, the differential pressure between the lower chamber 20 and the upper chamber 19 becomes large in the normal speed region where the piston speed is equal to or higher than the fourth predetermined value, but the lower chamber 20 and the cap chamber 146 communicate with each other when the sub valve 171 is opened. Moreover, the cap chamber 146 has an orifice 175 provided between the cap chamber 146 and the upper chamber 19, so that the flow of the oil liquid to the upper chamber 19 is restricted. Therefore, the differential pressure between the lower chamber 20 and the cap chamber 146 is small, and the deformation of the sub valve 181 due to the back pressure can be suppressed. Therefore, the durability of the sub valve 181 can be improved.
[0100]
　Since the second damping force generation mechanisms 173 and 183 that are independent in the contraction stroke and the expansion stroke are provided, the degree of freedom in setting the damping force characteristics is high.
[0101]
　In Patent Document 1 described above, two oil chambers are connected by parallel flow paths, and valves are provided in each of these flow paths, so that valves that open in the same stroke are arranged in parallel. .. By adopting a structure in which valves that open in the same stroke are arranged in parallel in this way, one valve is opened in the region where the piston speed is slower than the other valve, and both in the region where the piston speed is higher than this. The valve can be opened. In such a structure, it is particularly required to improve the durability of the valve on the low speed side.
[0102]
　On the other hand, in the shock absorber 1 of the first embodiment, the second damping of the second passages 172 and 182 parallel to the first passages 72 and 92 of the piston 18 provided with the first damping force generating mechanisms 41 and 42 is provided. The sub-valve 181 and the sub-valve 171 of the force generating mechanisms 173 and 183 are provided on the valve seat member 106 arranged in the lower chamber 20. At the same time, a bottomed cylindrical cap member 101 is provided between the piston 18 and the valve seat member 106 in the second passages 172 and 182, and the valve seat member 106 is arranged inside the cap member 101. At this time, the sub valve 181 is provided on the lower chamber 20 side, and the sub valve 171 is provided in the cap chamber 146 between the bottom portion 122 of the cap member 101 and the valve seat member 106. Then, the orifice 175 is arranged on the upstream side of the flow during the extension stroke when the sub valve 181 of the second passage 172 opens. As a result, the orifice 175 throttles the flow of the oil liquid that opens from the lower chamber 20 to the cap chamber 146 and flows to the upper chamber 19 during the contraction stroke. Therefore, the differential pressure between the cap chamber 146 and the lower chamber 20 becomes smaller, and the closed sub-valve 181 that receives the back pressure from the lower chamber 20 receives the same pressure as the lower chamber 20 from the cap chamber 146. , The back pressure (differential pressure) received will be suppressed. Therefore, the durability of the sub valve 181 can be improved.
[0103]
　The second passages 172 and 182 are not always communicating passages and do not have a always communicating fixed orifice. Therefore, the effect of suppressing the back pressure received by the sub valve 181 is high.
[0104]
　Since the piston rod 21 is inserted into the piston 18, the cap member 101, and the valve seat member 106, the piston 18, the cap member 101, and the valve seat member 106 can be arranged compactly.
[0105]
　Since the orifice 175 is formed by cutting out the disk 82 that abuts on the piston 18 in the first damping force generating mechanism 41 on the extension side, the orifice 175 can be easily formed.
[0106]
　Since each of the second passages 172 and 182 is formed by cutting out the piston rod 21, the second passages 172 and 182 can be easily formed.
[0107]
　Since the sub-valve 171 which is the inflow valve into the cap chamber 146 has a lower valve opening pressure than the sub-valve 181, the sub-valve 171 is opened from the lower chamber 20 during the contraction stroke, and the oil liquid easily flows into the cap chamber 146. Therefore, when the pressure in the lower chamber 20 is lower, the closed sub-valve 181 receives the same pressure as the lower chamber 20 from the cap chamber 146, and the back pressure received is suppressed. Therefore, the durability of the sub valve 181 can be further improved.
　Since the differential pressure between the cap chamber 146 and the lower chamber 20 does not increase in both expansion and contraction strokes, it is possible to use a thin pressed part for the cap member 107. Therefore, it is advantageous in terms of manufacturability and weight reduction.
[0108]
[Second Embodiment]
　Next, the second embodiment will be described mainly based on FIG. 6 with a focus on differences from the first embodiment. The parts common to the first embodiment are represented by the same name and the same reference numerals.
[0109]
　In the shock absorber 1A of the second embodiment, as shown in FIG. 6, a housing 147 composed of a cap member 101, a valve seat member 106, and an O-ring 107 similar to those of the first embodiment, and a passage formed inside the housing 147. The member 102, the disk 103, the disk 104, the contraction side subvalve 171 and the extension side subvalve 181 on the opposite side of the valve seat member 106 from the subvalve 171 have their axial orientations opposite to those of the first embodiment. It is provided.
[0110]
　The disc 85 of the first embodiment is not provided on the side opposite to the piston 18 of the main valve 91 on the extension side similar to that of the first embodiment, and a plurality of discs 84 similar to those of the first embodiment are provided (specifically). There are three). On the opposite side of these discs 84 from the main valve 91, a sub-valve 181 composed of a plurality of (specifically, three) discs 108 is stacked. A valve seat member 106 is superposed on the side of the sub-valve 181 opposite to the disk 84, with the inner seat portion 138 and the valve seat portion 139 facing the sub-valve 181 side.
[0111]
　Further, the inner seat portion 134, the intermediate valve seat portion 135, and the outer valve seat portion 136 facing to the side opposite to the sub valve 181 of the valve seat member 106 are contracted by a plurality of (specifically, two) discs 105. The sub-valve 171 on the side is overlapped. A disc 104, a disc 103, and a passage forming member 102 are superposed on the sub valve 171 in this order. In the passage forming member 102, the small diameter fitting hole 151 is oriented so as to face the disk 103 side.
[0112]
　Then, the cap member 101 abuts the bottom portion 122 on the large-diameter hole 152 and the passage groove 153 side of the passage forming member 102 so as to cover the valve seat member 106, the sub valve 171, the disk 104, the disk 103, and the passage forming member 102. The tubular portion 124 is covered with the valve seat member 106 so as to be fitted to the main portion 132 and the O-ring 107.
[0113]
　On the side of the bottom portion 122 of the cap member 101 opposite to the passage forming member 102, one disc 211 and one disc 109 similar to the first embodiment, both of which are the same disc 110 as the first embodiment. And the annular member 111 are overlapped with each other. A nut 112 is provided on the opposite side of the annular member 111 from the disk 110 by being screwed into the male screw 31. The disk 211 is made of metal. The disc 211 has a perforated circular flat plate shape having a constant thickness to which the mounting shaft portion 28 of the piston rod 21 can be fitted inside. The outer diameter of the disc 211 is the same as the outer diameter of the disc 110.
[0114]
　In the second embodiment, the axial distance of the passage forming member 102 from the piston 18 is longer than that in the first embodiment due to the above arrangement. Therefore, in accordance with this, the piston rod 21A of the second embodiment is formed with a passage notch 30A that is longer in the axial direction than the passage notch 30 of the piston rod 21 of the first embodiment. The passage in the passage notch 30A communicates with the passage in the large-diameter hole 152 of the passage forming member 102.
[0115]
　In such a second embodiment, in the contraction stroke, the passage in the outer passage hole 143, the passage between the sub-valve 171 to be opened and the outer valve seat portion 136, the cap chamber 146, and the passage of the passage forming member 102. It consists of a passage in the groove 153 and the large-diameter hole 152, a passage in the passage notch 30A of the piston rod 21A, a passage in the large-diameter hole 46 of the piston 18, and a passage in the notch 88 of the disk 82. Oil liquid flows from the lower chamber 20 to the upper chamber 19 through the orifice 175 and the passage in the passage hole 37. These form the second passage 172A on the contraction side.
[0116]
　In the extension stroke, an orifice 175 consisting of a passage in the passage hole 37 of the piston 18, a passage in the notch 88 of the disk 82, a passage in the large diameter hole 46 of the piston 18, and a passage notch of the piston rod 21A. The passage in 30A, the passage in the large-diameter hole 152 and the passage groove 153 of the passage forming member 102, the cap chamber 146, the passage in the through hole 161 of the disk 105, and the passage in the inner passage hole 141. The oil liquid flows from the upper chamber 19 to the lower chamber 20 through the passage between the sub valve 181 to be opened and the valve seat portion 139. These form the second passage 182A on the extension side.
[0117]
　The shock absorber 1A of the second embodiment has the same hydraulic circuit, operation and damping force characteristics as the shock absorber 1 of the first embodiment.
[0118]
[Third Embodiment]
　Next, the third embodiment will be described mainly based on FIG. 7, focusing on the differences from the first embodiment. The parts common to the first embodiment are represented by the same name and the same reference numerals.
[0119]
　As shown in FIG. 7, the shock absorber 1B of the third embodiment has a piston rod 21B having a structure partially different from that of the piston rod 21. The piston rod 21B is formed with a passage notch 30B extending to the shaft step 29 instead of the passage notch 30. A groove portion 215 extending in the radial direction and communicating with the passage notch 30B is formed in the shaft step portion 29 of the spindle portion 27 of the piston rod 21B. The passage in the passage notch 30B communicates with the passage in the large-diameter hole 152 of the passage forming member 102. As a result, the large-diameter hole 152 of the passage forming member 102 and the passage in the passage groove 153 are always in communication with the upper chamber 19 via the passage in the passage notch 30B and the passage in the groove 215.
[0120]
　In the third embodiment, the piston 18B has a structure partially different from that of the piston 18. The piston 18B includes a piston body 35B whose configuration is partially different from that of the piston body 35. The piston body 35B is formed with an insertion hole 44B having the same diameter as the small diameter hole portion 45, instead of the insertion hole 44 having the small diameter hole portion 45 and the large diameter hole portion 46 of the first embodiment.
[0121]
　Further, in the third embodiment, the first damping force generation mechanism 41B on the extension side, which is partially different in configuration from the first damping force generation mechanism 41 of the first embodiment, is provided. The first damping force generation mechanism 41B has a disc 82B in which the notch 88 is not formed, instead of the disc 82 in which the notch 88 of the first embodiment is formed.
[0122]
　In such a third embodiment, in the contraction stroke, the passage in the outer passage hole 143, the passage between the sub-valve 171 to be opened and the outer valve seat portion 136, the cap chamber 146, and the passage of the passage forming member 102. Oil liquid flows from the lower chamber 20 to the upper chamber 19 through the passage in the groove 153 and the large diameter hole 152 and the passage in the passage notch 30B and the groove 215 of the piston rod 21B. These form the second passage 172B on the contraction side.
[0123]
　In the second passage 172B, the passage in the passage groove 153 of the passage forming member 102 is the orifice 175B having the narrowest passage cross-sectional area in the fixed portion. The orifice 175B is arranged on the downstream side of the sub valve 171 in which the oil liquid flows in the second passage 172B and the oil liquid flows when the sub valve 171 opens.
[0124]
　In the extension stroke, the passage in the groove 215 and the passage notch 30B of the piston rod 21B, the passage in the large diameter hole 152 and the passage groove 153 of the passage forming member 102, the cap chamber 146, and the through hole of the sub valve 171. The oil liquid flows from the upper chamber 19 to the lower chamber 20 through the passage in 161, the passage in the inner passage hole 141, and the passage between the sub-valve 181 to be opened and the valve seat portion 139. These form the second passage 182B on the extension side.
[0125]
　Also in this second passage 182B, the passage in the passage groove 153 of the passage forming member 102 is the orifice 175B having the narrowest passage cross-sectional area in the fixed portion. The orifice 175B is arranged on the upstream side of the sub valve 181 of the oil liquid flow when the oil liquid flows in the second passage 182B and the sub valve 181 opens.
[0126]
　The shock absorber 1B of the third embodiment has the same hydraulic circuit, operation and damping force characteristics as the shock absorber 1 of the first embodiment.
[0127]
[Fourth Embodiment]
　Next, the fourth embodiment will be described mainly based on FIG. 8 with a focus on differences from the first embodiment. The parts common to the first embodiment are represented by the same name and the same reference numerals.
[0128]
　In the shock absorber 1C of the fourth embodiment, as shown in FIG. 8, the passage forming member 102 and the disk 103 of the first embodiment are not provided. Further, it has a housing 147C having a structure partially different from that of the housing 147. The housing 147C includes a valve seat member 106C having a structure partially different from that of the valve seat member 106, and a cap member 101C having a structure partially different from that of the cap member 101.
[0129]
　The valve seat member 106C is provided with a through hole 131C in the radial center of the main body portion 132. The through hole 131C includes a large-diameter hole portion 221 on the inner sheet portion 134 side in the axial direction and a small-diameter hole portion 222 on the inner sheet portion 138 side in the axial direction. The large diameter hole portion 221 has a larger diameter than the small diameter hole portion 222. The valve seat member 106C fits into the mounting shaft portion 28 in the small diameter hole portion 222. A plurality of passage cutouts 223 penetrating the inner seat portion 134 in the radial direction are formed in the valve seat member 106C at equal intervals in the circumferential direction.
[0130]
　In order to communicate with the passage in the large diameter hole portion 221 of the valve seat member 106C, the piston rod 21C of the fourth embodiment has a piston rod of the first embodiment having a length in the axial direction of the piston rod 21C of the passage notch 30C. It is longer than 21.
[0131]
　The cap member 101C of the fourth embodiment has a bottom portion 122C having an outer diameter larger than the outer diameter of the bottom portion 122 of the first embodiment, and an intermediate tapered portion 123 having an axial length and a radial width of the first embodiment. It has a smaller intermediate tapered portion 123C and a tubular portion 124C having an axial length longer than that of the tubular portion 124. The cap member 101C has a bottom portion 122C that regulates deformation of the sub-valve 171 on the contraction side beyond the specified direction in the opening direction.
[0132]
　In the fourth embodiment, a plurality of (specifically, two) discs 104 are provided. The disk 104 is in contact with the bottom 122C of the cap member 101C.
[0133]
　In such a fourth embodiment, in the contraction stroke, the passage in the outer passage hole 143, the passage between the sub-valve 171 to be opened and the outer valve seat portion 136, the cap chamber 146, and the through hole 161 of the sub-valve 171 are used. Inside passage, passage in passage notch 223 and large diameter hole 221 of valve seat member 106C, passage in passage notch 30C of piston rod 21C, and passage in large diameter hole 46 of piston 18. Oil liquid flows from the lower chamber 20 to the upper chamber 19 through the orifice 175 formed by the passage in the notch 88 of the disk 82 and the passage in the passage hole 37. These form the second passage 172C on the contraction side.
[0134]
　In the extension stroke, an orifice 175 consisting of a passage in the passage hole 37 of the piston 18, a passage in the notch 88 of the disk 82, a passage in the large diameter hole 46 of the piston 18, and a passage notch of the piston rod 21C. The passage in 30C, the passage in the large-diameter hole portion 221 and the passage notch 223 of the valve seat member 106C, the passage in the inner passage hole 141, and the passage between the sub-valve 181 and the valve seat portion 139 to be opened. The oil liquid flows from the upper chamber 19 to the lower chamber 20 via the above. These form the second passage 182C on the extension side. The passage in the passage notch 223 is always in communication with the passage in the through hole 161 of the disk 105.
[0135]
　The shock absorber 1C of the fourth embodiment has the same hydraulic circuit, operation and damping force characteristics as the shock absorber 1 of the first embodiment.
[0136]
[Fifth Embodiment]
　Next, the fifth embodiment will be described mainly based on FIGS. 9 and 10, focusing on the differences from the third and fourth embodiments. The parts common to the third and fourth embodiments are represented by the same names and the same reference numerals.
[0137]
　In the shock absorber 1D of the fifth embodiment, as shown in FIG. 9, the first damping force generating mechanism 41B including the disk 82B, the piston 18B and the piston rod 21B, and the fourth embodiment are the same as those of the third embodiment. Similar to the above, the cap member 101C and a plurality of (specifically, two) discs 104 are provided.
[0138]
　In the fifth embodiment, the housing 147D has a structure partially different from that of the housing 147C. The housing 147D includes a valve seat member 106D that differs from the valve seat member 106C in that a passage notch 223 is not formed.
[0139]
　Further, it has a second damping force generation mechanism 173D whose configuration is partially different from that of the second damping force generation mechanism 173. The second damping force generation mechanism 173D includes a sub-valve 171D in which the disc 105D abutting on the valve seat member 106D is partially different from the disc 105 in the sub-valve 171. As shown in FIG. 10, the disk 105D is formed with a notch 231 extending from the inside to the inner peripheral edge portion of the radial through hole 161. As for the passage in the notch 231, the passage in the passage notch 30B of the piston rod 21B and the passage in the large diameter hole 221 of the valve seat member 106D are always communicated with the passage in the inner passage hole 141.
[0140]
　In such a fifth embodiment, in the contraction stroke, the passage in the outer passage hole 143 shown in FIG. 9, the passage between the sub-valve 171D to be opened and the outer valve seat portion 136, the cap chamber 146, and the sub-valve 171D. Through the passage in the through hole 161, the passage in the notch 231 of the disk 105D, the passage in the large diameter hole 221 of the valve seat member 106D, and the passage in the passage notch 30B of the piston rod 21B. , Oil liquid flows from the lower chamber 20 to the upper chamber 19. These form the second passage 172D on the contraction side.
[0141]
　In the second passage 172D, the passage in the notch 231 of the disk 105D is the narrowest orifice 175D in the portion where the cross-sectional area of ​​the flow path is fixed. The orifice 175D is arranged on the downstream side of the sub valve 171D in which the oil liquid flows in the second passage 172D and the oil liquid flows when the sub valve 171D opens.
[0142]
　In the extension stroke, the passage in the passage notch 30B of the piston rod 21B, the passage in the large-diameter hole 221 of the valve seat member 106C, the passage in the notch 231 of the disk 105D, and the inner passage of the valve seat member 106C. Oil liquid flows from the upper chamber 19 to the lower chamber 20 through the passage in the hole 141 and the passage between the sub-valve 181 to be opened and the valve seat portion 139. These form the second passage 182D on the extension side.
[0143]
　In the second passage 182D, the passage in the notch 231 of the disk 105D is the narrowest orifice 175D in the portion where the cross-sectional area of ​​the flow path is fixed. The orifice 175D is arranged on the upstream side of the sub valve 181 of the oil liquid flow when the oil liquid flows in the second passage 182D and the sub valve 181 opens.
[0144]
　The shock absorber 1D of the fifth embodiment has the same hydraulic circuit, operation and damping force characteristics as the shock absorber 1 of the first embodiment.
[0145]
[Sixth Embodiment]
　Next, the sixth embodiment will be described mainly based on FIGS. 11 and 12, focusing on the differences from the fourth embodiment. The parts common to the fourth embodiment are represented by the same name and the same reference numerals.
[0146]
　As shown in FIG. 11, the shock absorber 1E of the sixth embodiment has a cap member 101E having a structure partially different from that of the cap member 101C. The cap member 101E does not have the intermediate tapered portion 123C of the fourth embodiment, and has a bottom portion 122E having a large outer diameter of the bottom portion 122C and a tubular portion 124E having a long axial length of the tubular portion 124C. There is.
[0147]
　The shock absorber 1E has a valve seat member 106E whose configuration is partially different from that of the valve seat member 106C of the fourth embodiment. The valve seat member 106E is not formed with a passage notch 223. The valve seat member 106E has a through hole 131E in the center in the radial direction. In the through hole 131E, a large-diameter hole portion 221E is formed on the inner seat portion 138 and the valve seat portion 139 in the axial direction, and has a smaller diameter than the large-diameter hole portion 221E and fits into the mounting shaft portion 28. Is formed on the inner seat portion 134, the intermediate valve seat portion 135, and the outer valve seat portion 136 in the axial direction.
[0148]
　Similar to the fourth embodiment, a plurality of (specifically, two) discs 104 and a contraction-side sub-valve 171 are provided inside the housing 147E including the cap member 101E, the valve seat member 106E, and the O-ring 107. There is. The sub valve 171 abuts on the inner seat portion 134, the intermediate valve seat portion 135, and the outer valve seat portion 136 of the valve seat member 106E. The plurality of discs 104 are provided between the sub valve 171 and the bottom portion 122E of the cap member 101E.
[0149]
　The housing 147E, the contraction side sub-valve 171 and the plurality of discs 104 are provided with the axial direction opposite to that of the fourth embodiment.
[0150]
　The shock absorber 1E has a second damping force generation mechanism 183E on the extension side, which is partially different in configuration from the second damping force generation mechanism 183. The second damping force generation mechanism 183E includes a sub valve 181E. The sub-valve 181E has a partially different configuration from the disc 108 in that the disc 108E that abuts on the inner seat portion 138 and the valve seat portion 139 of the valve seat member 106E is different from the sub-valve 181 of the fourth embodiment. As shown in FIG. 12, the disk 108E is formed with a notch 241 extending from an intermediate position inside the valve seat portion 139 in the radial direction to an inner peripheral edge portion.
[0151]
　As shown in FIG. 11, the sub valve 181E is also provided with the axial direction opposite to that of the fourth embodiment, similarly to the valve seat member 106E. That is, a plurality of (specifically, three) discs 84 and the sub-valve 181E are stacked on the extension-side main valve 91 in this order. At that time, in the sub-valve 181E, a plurality of (specifically, two) discs 108 are arranged on the side of the axial disc 84, and one disc 108E is arranged on the side opposite to the axial disc 84. Then, on the side of the sub-valve 181E opposite to the axial disc 84, the valve seat member 106E with the O-ring 107 mounted, the sub-valve 171 and a plurality of discs 104 are stacked in this order, and the valve seat member 106E, A cap member 101E is covered so as to cover the sub valve 171 and a plurality of discs 104.
[0152]
　The notch 241 of the disc 108E of the sub valve 181E is formed in a range radially inside the valve seat portion 139. The passage in the notch 241 communicates the passage in the passage notch 30C of the piston rod 21C and the passage in the large diameter hole 221E of the valve seat member 106E with the passage between the sub valve 181E and the valve seat portion 139. .. The passage in the notch 241 communicates with the cap chamber 146 via the passage in the inner passage hole 141 and the through hole 161 of the sub valve 171.
[0153]
　A disc 242, a disc 109, a disc 110, and an annular member 111 are stacked on the side of the bottom 122E of the cap member 101E opposite to the disc 104. The disc 242 is made of metal. The disc 242 has a perforated circular flat plate shape having a constant thickness to which the mounting shaft portion 28 of the piston rod 21 can be fitted inside. The outer diameter of the disc 242 is the same as the outer diameter of the disc 110.
[0154]
　In such a sixth embodiment, in the contraction stroke, when the sub-valve 171 is separated from the outer valve seat portion 136, it is between the passage in the outer passage hole 143 and the opened sub-valve 171 and the outer valve seat portion 136. , The cap chamber 146, the passage in the through hole 161 of the sub valve 171, the passage in the inner passage hole 141 of the valve seat member 106E, the passage in the notch 241 of the disk 108E, and the valve seat member 106E. The lower chamber is passed through the passage in the large-diameter hole portion 221E, the passage in the passage notch 30C of the piston rod 21C, the passage in the notch 88 of the disk 82, and the passage in the passage hole 37 of the piston 18. Oil liquid flows from 20 to the upper chamber 19. These form the second passage 172E on the contraction side.
[0155]
　At this time, in addition to the passage in the notch 88 of the disc 82 becoming the orifice 175, the passage in the notch 241 of the disc 108E becomes the orifice 245. The orifice 175 and the orifice 245 are arranged in series on the downstream side of the sub valve 171 of the oil liquid flow when the oil liquid flows in the second passage 172E and the sub valve 171 opens.
[0156]
　In the extension stroke, the passage in the passage hole 37 of the piston 18, the passage in the notch 88 of the disk 82, the passage in the large diameter hole 46 of the piston 18, and the passage in the passage notch 30C of the piston rod 21C. From the upper chamber 19 to the lower chamber via the passage in the large-diameter hole portion 221E of the valve seat member 106E, the passage in the notch portion 241 of the disk 108E, and the passage between the sub valve 181E and the valve seat portion 139. Oil liquid flows in 20. These form the second passage 182E on the extension side.
[0157]
　Also at this time, in addition to the passage in the notch 88 of the disk 82 becoming the orifice 175, the passage in the notch 241 of the disk 108E becomes the orifice 245. The orifice 175 and the orifice 245 are arranged in series on the upstream side of the sub valve 181E of the oil liquid flow when the oil liquid flows in the second passage 182E and the sub valve 181E opens.
[0158]
　In the shock absorber 1E of the sixth embodiment, the degree of freedom in setting the orifice is increased by the two series orifices of the orifice 175 and the orifice 245.
[0159]
[7th Embodiment]
　Next, the 7th embodiment will be described mainly based on FIG. 13 with a focus on differences from the 3rd embodiment. The parts common to the third embodiment are represented by the same name and the same reference numerals.
[0160]
　As shown in FIG. 13, the shock absorber 1F of the seventh embodiment has a piston 18F having a configuration partially different from that of the piston 18B of the third embodiment. In the piston 18F, the piston body 35F is different from the piston body 35B.
[0161]
　An insertion hole 44F is formed in the piston main body 35F at the center in the radial direction so as to penetrate in the axial direction. The insertion hole 44F fits the mounting shaft portion 28 of the piston rod 21. The piston body 35F allows communication between a plurality of passage holes 37F capable of communicating the upper chamber 19 and the lower chamber 20 (only one place is shown in FIG. 13 due to the cross section), and the upper chamber 19 and the lower chamber 20 can communicate with each other. There are a plurality of passage holes 39F (only one is shown in FIG. 13 because of the cross section). The piston body 35F is a sintered product. Passage holes 37F and 39F are formed in the piston body 35F at the time of sintering or by cutting with a drill.
[0162]
　The plurality of passage holes 37F are parallel to the axial direction of the piston body 35F. The plurality of passage holes 39F are also parallel to the axial direction of the piston body 35F.
[0163]
　At the end of the piston body 35F on the lower chamber 20 side in the axial direction, an annular inner seat portion 47F is formed inside the piston body 35F in the radial direction from the opening on the lower chamber 20 side of the passage hole 37F. .. At the end of the piston body 35F on the lower chamber 20 side in the axial direction, a valve seat portion 48F is formed which surrounds the opening on the lower chamber 20 side of each passage hole 37F in an annular shape with the inner seat portion 47F. ..
[0164]
　At the end of the piston body 35F on the upper chamber 19 side in the axial direction, an annular inner seat portion 49F is formed inside the piston body 35F in the radial direction from the opening on the upper chamber 19 side of the passage hole 39F. .. At the end of the piston body 35F on the upper chamber 19 side in the axial direction, a valve seat portion 50F is formed which surrounds the opening of each of the passage holes 39F on the upper chamber 19 side in an annular shape with the inner seat portion 49F. ..
[0165]
　At the end of the piston body 35F on the lower chamber 20 side in the axial direction, a step portion 251 is cut at each opening position of the passage hole 39F in the circumferential direction so as to be located axially inside the inner seat portion 47F. It is missing and formed. The step portion 251 always communicates the passage hole 39F at which the position matches with the lower chamber 20. At the end of the piston body 35F on the upper chamber 19 side in the axial direction, a step portion 252 is cut at each opening position of the passage hole 37F in the circumferential direction so as to be located axially inside the inner seat portion 49F. It is missing and formed. The step portion 252 always communicates the passage hole 37F in which the position is matched with the upper chamber 19.
[0166]
　In the seventh embodiment, the main valve 71F on the contraction side, which is partially different in configuration from the main valve 71, is provided. The main valve 71F is provided with the disc 63F at an intermediate predetermined position in the stacking direction of the plurality of discs 63. The disk 63F is formed with a protrusion 255 that projects radially outward on one side in the axial direction. The protrusion 255 protrudes toward the valve seat portion 50F. The protrusion 255 presses the outer peripheral side of one disc 63, which is closer to the valve seat portion 50F than the disc 63F, against the valve seat portion 50F. The main valve 71F always abuts on the inner seat portion 49F and takes off and sits on the valve seat portion 50F. The main valve 71F and the valve seat portion 50F form a first damping force generation mechanism 42F on the contraction side.
[0167]
　In the seventh embodiment, the extension side main valve 91F having a configuration partially different from that of the main valve 91 is provided. The main valve 91F is provided with a disc 83F at an intermediate predetermined position in the stacking direction of a plurality of discs 83. The disk 83F is formed with a protrusion 256 that projects radially outward. The protrusion 256 protrudes toward the valve seat portion 48F. The protrusion 256 presses the outer peripheral side of one disc 83, which is closer to the valve seat portion 48F than the disc 83F, against the valve seat portion 48F. The main valve 91F always abuts on the inner seat portion 47F and takes off and sits on the valve seat portion 48F. The main valve 91F and the valve seat portion 48F form the first damping force generation mechanism 41F.
[0168]
　In the seventh embodiment, the passage between the main valve 71F and the valve seat portion 50F, the passage in the passage hole 39F, and the passage in the step portion 251 appearing at the time of opening the valve in the contraction stroke are the second on the contraction side. It constitutes one passage 72F. The passage between the main valve 91F and the valve seat portion 48F that appears when the valve is opened in the extension stroke, the passage in the passage hole 37F, and the passage in the step portion 252 form the first passage 92F on the extension side. ing.
[0169]
[Eighth Embodiment]
　Next, the eighth embodiment will be described mainly based on FIG. 14, focusing on the differences from the third embodiment. The parts common to the third embodiment are represented by the same name and the same reference numerals.
[0170]
　As shown in FIG. 14, the shock absorber 1G of the eighth embodiment has a piston 18G having a structure partially different from that of the piston 18B of the third embodiment. In the piston 18G, the piston body 35G has a partially different configuration from the piston body 35B.
[0171]
　An insertion hole 44G is formed in the piston main body 35G in the center in the radial direction so as to penetrate in the axial direction. The insertion hole 44G fits the mounting shaft portion 28 of the piston rod 21B. The piston body 35G is provided with a plurality of passage holes 37G in which the upper chamber 19 and the lower chamber 20 can communicate with each other, and a plurality of passage holes 39G in which the upper chamber 19 and the lower chamber 20 can communicate with each other. The piston body 35G is a sintered product. In the piston body 35G, passage holes 37G and 39G are formed at the time of sintering or by cutting with a drill.
[0172]
　The plurality of passage holes 37G extend parallel to the axial direction of the piston body 35G. The plurality of passage holes 39G also extend parallel to the axial direction of the piston body 35G. The plurality of passage holes 37G are formed inside the piston body 35G in the radial direction with respect to the plurality of passage holes 39G.
[0173]
　A recess 261 is formed in the center in the radial direction at the end of the piston body 35G on the lower chamber 20 side in the axial direction. The recess 261 is recessed toward the upper chamber 19 side in the axial direction. At the bottom position of the recess 261, an annular inner sheet portion 47G is formed inside the piston body 35G in the radial direction from the opening on the lower chamber 20 side of the passage hole 37G. The bottom position of the recess 261 is outside the opening on the lower chamber 20 side of the passage hole 37G in the radial direction of the piston body 35G, and is radially outside the opening on the lower chamber 20 side of the passage hole 39G. An annular valve seat portion 48G is formed on the inner side of the wheel.
[0174]
　At the end of the piston body 35G on the upper chamber 19 side in the axial direction, an annular inner seat portion 49G is formed inside the piston body 35G in the radial direction from the opening on the upper chamber 19 side of the passage hole 37G. .. At the end of the piston body 35G on the upper chamber 19 side in the axial direction, the outside of the opening on the upper chamber 19 side of the passage hole 37G in the radial direction of the piston body 35G, and on the upper chamber 19 side of the passage hole 39G. An annular intermediate valve seat portion 265 is formed inside the piston body 35G in the radial direction from the opening. At the end of the piston body 35G on the upper chamber 19 side in the axial direction, an annular outer valve seat portion 50G is formed on the outer side in the radial direction of the piston body 35G from the opening on the upper chamber 19 side of the passage hole 39G. There is.
[0175]
　In the eighth embodiment, the main valve 71G on the contraction side is provided instead of the main valve 71. The main valve 71G is composed of a plurality of (specifically, two) discs 63G. The main valve 71G always abuts on the inner seat portion 49G, and abuts on the intermediate valve seat portion 265 and the outer valve seat portion 50G so as to be able to take off and sit. The main valve 71G opens and closes the passage in the passage hole 39G on the contraction side. The intermediate valve seat portion 265, the outer valve seat portion 50G, and the main valve 71G form a second damping force generation mechanism 42G on the contraction side.
[0176]
　On the side of the main valve 71G opposite to the axial piston 18G, a plurality of (specifically, two) disks 65G having an outer diameter smaller than the outer diameter of the main valve 71G are provided. An annular member 67G is provided on the side of the disk 65G opposite to the main valve 71G in the axial direction. The outer diameter of the annular member 67G is the same as the outer diameter of the main valve 71G, and the annular member 67G is in contact with the shaft step portion 29. The annular member 67G regulates the deformation of the main valve 71G in the opening direction beyond the specified value. The disk 63G is formed with a through hole 267 at a position between the intermediate valve seat portion 265 and the inner seat portion 49G. A through hole 268 is also formed in the disk 65G by aligning the radial position with the through hole 267. These through holes 267 and 268 always communicate the passage in the passage hole 37G to the upper chamber 19.
[0177]
　In the eighth embodiment, the extension side main valve 91G is provided instead of the main valve 91. The main valve 91G is composed of a plurality of (specifically, five) discs 83G. The main valve 91G always abuts on the inner seat portion 47G and abuts on the valve seat portion 48G so as to be able to take off and sit. The main valve 91G opens and closes the passage in the passage hole 37G on the extension side. The side of the main valve 91G opposite to the piston 18G is in contact with the disk 84.
[0178]
　In the eighth embodiment, the passage between the main valve 71G and the outer valve seat portion 50G that appears when the valve is opened in the contraction stroke and the passage in the passage hole 39G form the first passage 72G on the contraction side. There is. Further, the passage between the main valve 91G and the valve seat portion 48G, the passage in the passage hole 37G, and the passage in the through holes 267 and 268, which appear when the valve is opened in the extension stroke, are the first passages on the extension side. It constitutes 92G.
[0179]
　The main valve 91G, the disc 84, the disc 85, the bottom portion 122 of the cap member 101, and the intermediate tapered portion 123 are arranged in the recess 261 of the piston body 35G of the piston 18G. As a result, the axial length of the entire component mounted on the mounting shaft portion 28 of the piston rod 21B is shortened.
[0180]
[9th Embodiment]
　Next, the 9th embodiment will be described mainly based on FIG. 15 with a focus on differences from the 3rd embodiment. The parts common to the third embodiment are represented by the same name and the same reference numerals.
[0181]
　As shown in FIG. 15, the shock absorber 1H of the ninth embodiment has a piston 18H having a structure partially different from that of the piston 18B of the third embodiment. In the piston 18H, the piston main body 35H has a partially different configuration from the piston main body 35.
[0182]
　An insertion hole 44H is formed in the piston main body 35H at the center in the radial direction so as to penetrate in the axial direction. The insertion hole 44H fits the mounting shaft portion 28 of the piston rod 21. The piston body 35H allows communication between a plurality of passage holes 37H capable of communicating the upper chamber 19 and the lower chamber 20 (only one place is shown in FIG. 15 due to the cross section), and the upper chamber 19 and the lower chamber 20. There are a plurality of passage holes 39H (only one is shown in FIG. 15 because of the cross section). In the piston body 35H, the passage holes 37H and 39H are formed by cutting.
[0183]
　The plurality of passage holes 37H have a linear shape as a whole. The plurality of passage holes 37H are inclined with respect to the axial direction of the piston body 35H. The plurality of passage holes 39H are also linear as a whole. The plurality of passage holes 39H are also inclined with respect to the axial direction of the piston body 35H. In the plurality of passage holes 37H, the upper chamber 19 side is located outside the lower chamber 20 side in the radial direction of the piston body 35H. In the plurality of passage holes 39H, the lower chamber 20 side is located outside the upper chamber 19 side in the radial direction of the piston body 35H. The piston body 35H has a shape that makes no distinction between the front and back sides, and has the same shape regardless of which direction the piston rod 21 is attached to in the axial direction.
[0184]
　At the end of the piston body 35H on the lower chamber 20 side in the axial direction, an annular inner seat portion 47H is formed inside the piston body 35H in the radial direction from the opening on the lower chamber 20 side of the passage hole 37H. .. At the end of the piston body 35H on the lower chamber 20 side in the axial direction, an annular valve seat portion 48H is formed on the outer side in the radial direction of the piston body 35H from the opening on the lower chamber 20 side of the passage hole 37H. .. The inner seat portion 47H is recessed inward in the axial direction of the piston body 35H from the valve seat portion 48H.
[0185]
　At the end of the piston body 35H on the upper chamber 19 side in the axial direction, an annular inner sheet portion 49H is formed inside the piston body 35H in the radial direction from the opening on the upper chamber 19 side of the passage hole 39H. .. At the end of the piston body 35H on the upper chamber 19 side in the axial direction, an annular valve seat portion 50H is formed on the outer side in the radial direction of the piston body 35H from the opening on the upper chamber 19 side of the passage hole 39H. ..
[0186]
　In the ninth embodiment, the second damping force generation mechanism 42H having a configuration partially different from that of the second damping force generation mechanism 42 is provided. The second damping force generation mechanism 42H has a main valve 71H which is different from the main valve 71 in that a plurality of (specifically, three) disks 62 are provided.
[0187]
　In the ninth embodiment, the first damping force generation mechanism 41H having a configuration partially different from that of the first damping force generation mechanism 41B is provided. The first damping force generation mechanism 41H has a main valve 91H. The main valve 91H differs from the main valve 91 in that a plurality of (specifically, two) discs 82H are provided on the opposite side of the disc 82B from the disc 83. The side of the disc 82H opposite to the disc 82B is in contact with the inner sheet portion 47H. The outer diameter of the disc 82H is smaller than the outer diameter of the disc 82B.
[0188]
　In the ninth embodiment, the passage between the main valve 71H and the valve seat portion 50H that appears when the valve is opened in the contraction stroke and the passage in the passage hole 39H constitute the first passage 72H on the contraction side. .. Further, the passage between the main valve 91H and the valve seat portion 48H, which appears when the valve is opened in the extension stroke, and the passage in the passage hole 37H form the first passage 92H on the extension side.
[0189]
　In the 7th to 9th embodiments, changes to the 3rd embodiment have been described as an example, but any of the structures of the 7th to 9th embodiments has the first, second, fourth to sixth embodiments. Applicable to.
[0190]
　Further, the above embodiment shows an example in which the present invention is used for a double-cylinder type hydraulic shock absorber, but the present invention is not limited to this, and the outer cylinder is eliminated and the side opposite to the upper chamber 19 of the lower chamber 20 in the cylinder 2. It may be used for a monotube type hydraulic shock absorber that forms a gas chamber with a slidable compartment, and is used for any shock absorber including a pressure control valve using a packing valve having a structure in which a sealing member is provided on a disk. be able to.
[0191]
　According to the first aspect of the embodiment described above, the shock absorber is slidably provided in the cylinder in which the working fluid is sealed and in the cylinder, and the inside of the cylinder is divided into one side chamber and the other side chamber. The piston to be partitioned, the piston rod connected to the piston and extended to the outside of the cylinder, and the movement of the piston causes the working fluid to flow out from the chamber on the upstream side to the chamber on the downstream side in the cylinder. The first passage and the second passage, the first damping force generating mechanism provided in the first passage provided in the piston, and the annular valve seat member arranged in the other side chamber are provided. The first passage is provided with a second damping force generating mechanism provided in the second passage in parallel with the first passage to generate a damping force. The second damping force generation mechanism includes a first sub-valve provided on one side of the second passage provided in the valve seat member, a second sub-valve provided on the other side, and the piston and the valve in the second passage. It is provided with a bottomed tubular cap member provided between the seat member and the seat member. The valve seat member is provided in the cap member. The first sub-valve is provided in the other concubine. The second sub-valve is provided in a cap chamber between the bottom of the cap member and the valve seat member. In the second passage, an orifice is arranged on the upstream side or the downstream side of the flow in which the first sub-valve opens. In the region where the piston speed is low, the first damping force generation mechanism is opened while the valve is closed, and in the speed region where the piston speed is higher than the low speed, the first damping force generation mechanism is opened. And the second damping force generation mechanism both open. This makes it possible to improve the durability of the valve.
[0192]
　In the second aspect, in the first aspect, the second passage is not a communication passage at all times.
[0193]
　In the third aspect, in the first or second aspect, the piston rod is inserted into the piston, the cap member, and the valve seat member.
[0194]
　A fourth aspect is, in any one of the first to third aspects, the orifice is formed by cutting out a disk in contact with the piston in the first damping force generating mechanism.
[0195]
　A fifth aspect is in any one of the first to fourth aspects, the second passage is formed by cutting out the piston rod.
[0196]
　In the sixth aspect, in any one of the first to fifth aspects, the second sub-valve, which is the inflow valve into the cap chamber, has a lower valve opening pressure than the first sub-valve.
[0197]
　In the seventh aspect, in any one of the first to sixth aspects, the cap member is a pressed part.
Industrial applicability
[0198]
　According to the above-mentioned shock absorber, it is possible to improve the durability of the valve.
Description of the sign
[0199]
　1,1A 　to 1H Shock absorber
　2 Cylinder
18, 18B, 18F to 18H Piston
　19 Upper chamber (one side chamber)
　20 Lower chamber (other side chamber)
　21,21B Piston rods
　41, 41B, 41F to 41H First damping force generation mechanism
　42 , 42B, 42F to 42H 1st damping force generation mechanism
　72, 72F to 72H 1st passage
　92, 92F to 92H 1st passage
　101, 101C, 101E Cap members
　106, 106C to 106E Valve seat members
　122, 122C, 122E Bottom
　146 Cap chamber
　171, 171D Sub valve (second
　sub valve) 172, 172A to 172E Second passage
　173, 173D Second damping force generation mechanism
　175, 175B, 175D, 245 Piston 181, 181E
　Sub valve (first
　sub valve) 182, 182A to 182E 2nd passage
　183,183E 2nd damping force generation mechanism
The scope of the claims
[Claim 1]
　A cylinder in which a working fluid is sealed, a piston
　slidably provided in the cylinder and partitioning the inside of the cylinder into a one-side chamber and another side chamber, and a piston
　connected to the piston and extended to the outside of the cylinder. The piston rod is 　provided in
　the first passage and the second passage through which the working fluid flows from the chamber on the upstream side to the chamber on the downstream side in the cylinder due to the movement of the piston, and the first passage
provided in the piston. It is provided in the first damping force generation mechanism that generates the damping force and the
　annular valve seat member arranged in the other side chamber, and is provided in the second passage parallel to the first passage to generate the damping force. A second damping force generating mechanism for generating
　is provided, and
　the second damping force generating mechanism is provided on one side of the second passage provided on the valve seat member and a second sub-valve provided on the other side. The sub-valve is
　provided with a bottomed tubular cap member provided between the piston and the valve seat member in the second passage,
and the
　valve seat member is provided in the cap member, and the first sub-valve is provided. Is provided in the other side chamber, the second sub-valve is provided in the cap chamber between the bottom of the cap member and the valve seat member, and
　the second passage is on the upstream side of the flow in which the first sub-valve opens. Or, in
　the region where the orifice is arranged on the downstream side and the piston speed is low, the first damping force generating mechanism opens while the first damping force generating mechanism is closed.
　A
　shock absorber in which both the first damping force generating mechanism and the second damping force generating mechanism open in a speed region where the piston speed is higher than the low speed .
[Claim 2]

　The shock absorber according to claim 1, 　wherein the second passage is not a communication passage at all times .
[Claim 3]

　The shock absorber according to claim 1 or 2 　, wherein the piston rod is inserted into the piston, the cap member, and the valve seat member .
[Claim 4]

　The shock absorber according to any one of claims 1 to 3 　, wherein the orifice is formed by cutting out a disk in contact with the piston in the first damping force generating mechanism .
[Claim 5]

　The shock absorber according to any one of claims 1 to 4, 　wherein the second passage is formed by cutting out the piston rod .
[Claim 6]
　The shock absorber according to
　any one of claims 1 to 5, wherein the second sub-valve, which is an inflow valve into the cap chamber, has a lower valve opening pressure than the first sub-valve .
[Claim 7]

　The shock absorber according to any one of claims 1 to 6, 　wherein the cap member is a pressed part .