Title of the invention: Brake disc mounting structure for railway vehicles, and a brake disc unit using the same.
Technical field
[0001]
The present disclosure relates to a brake disc mounting structure, and more particularly to a structure in which an annular brake disc is mounted on a wheel of a railroad vehicle or a disc body fixed to an axle of a railroad vehicle. Further, the present disclosure relates to a brake disc unit using the mounting structure.
Background technology
[0002]
Conventionally, disc brakes have been used as braking devices for railway vehicles. The disc brake comprises an annular brake disc and a brake lining. The brake disc is fastened to the wheel of a railroad vehicle or to a disc body fixed to an axle. The brake lining is pressed against the sliding surface of the brake disc. The friction between the brake discs and the brake linings brakes the wheels.
[0003]
Patent Document 1 discloses a brake disc fastened to each side surface of a wheel by bolts and nuts. An elastic body such as a disc spring is arranged between the brake disc and the head or nut of the bolt. According to Patent Document 1, by optimizing the elastic modulus of the elastic body, it is possible to reduce the bending load and the tensile load on the bolt.
[0004]
Patent Document 2 discloses a fastening structure between a wheel or a disc body and a brake disc. In the fastening structure, a disc spring is arranged between the brake disc and the nut. In the fastened state of the wheel or disc body and the brake disc, the disc spring is arranged so that its concave surface faces the seat surface of the nut and comes into contact with the outer peripheral portion of the seat surface of the nut. According to Patent Document 2, the stress concentration at the R portion of the screw bottom of the bolt can be reduced by bringing the disc spring into contact with the outer peripheral portion of the bearing surface of the nut.
[0005]
Various elastic bodies have been proposed as the elastic bodies arranged between the members. For example, Patent Document 3 discloses an elastic body arranged above and below the first member when the first member and the second member are fastened with bolts. In Patent Document 3, each of the upper and lower elastic bodies has a conical portion that functions as a disc spring. The upper elastic body is fixed to the head of the bolt and the first member.
[0006]
Further, for example, Patent Document 4 discloses a washer (belleville spring) interposed between the object to be fastened and the head or nut of the bolt. This disc spring has a pressing portion and a spring portion. The pressing portion contacts the head of the bolt or the bearing surface of the nut. The spring portion has a concave surface facing the object to be fastened, and the diameter increases from the pressing portion toward the object to be fastened. The maximum outer diameter of the pressing portion is smaller than the maximum outer diameter of the spring portion. According to Patent Document 4, with this configuration, the load acting on the pressing portion can be concentrated on the central portion of the spring portion, and the spring portion can be reliably compressed and deformed.
Prior art literature
Patent documents
[0007]
Patent Document 1: Japanese Patent No. 4305296
Patent Document 2: Japanese Patent No. 4748390
Patent Document 3: Japanese Unexamined Patent Publication No. 2010-060031
Patent Document 4: Japanese Unexamined Patent Publication No. 2002-323029
Outline of the invention
Problems to be solved by the invention
[0008]
Brake discs for railway vehicles as disclosed in Patent Documents 1 and 2 are thermally deformed by frictional heat generated between the brake lining and the brake disc during wheel braking. This increases the load on the fastening member that fastens the brake disc to the wheel or disc body. In order to reduce the load on the fastening member, a disc spring (elastic body) as disclosed in each patent document can be used. However, for example, in a centrally fastened type brake disc in which a fastening portion is provided in the center of the sliding surface, the space for arranging the disc spring is limited, so that the spring constant of the disc spring cannot be sufficiently reduced. There is. As a result, the reduction of the load on the fastening member becomes insufficient, and the fatigue strength of the fastening member may decrease.
[0009]
It is an object of the present disclosure to improve the fatigue strength of a fastening member in a brake disc for a railway vehicle to be fastened to a mounted member by a fastening member.
Means to solve problems
[0010]
The mounting structure according to the present disclosure is a structure in which an annular brake disc is mounted on the mounted member. The attached member may be a wheel of a railroad vehicle, or may be a disc body fixed to an axle of the railroad vehicle. The mounting structure includes a fastening member and an elastic member. The fastening member fastens the brake disc to the attached member. The fastening member has a bolt and a nut. The bolt includes a shaft portion. The shaft portion penetrates the brake disc and the mounted member. The nut is attached to the end of the shaft on the brake disc side. The elastic member is placed between the nut and the brake disc. The elastic member has a cylindrical member body and a first flange. A shaft portion is inserted into the member body. The first flange is connected to the end on the nut side of both ends of the member body. The first flange projects outward from the member body and comes into contact with the outer peripheral portion of the nut.
The invention's effect
[0011]
According to the present disclosure, it is possible to improve the fatigue strength of the fastening member in the brake disc for a railway vehicle that is fastened to the mounted member by the fastening member.
A brief description of the drawing
[0012]
FIG. 1 is a plan view of the brake disc unit according to the first embodiment.
FIG. 2 is a cross-sectional view taken along the line II-II of the brake disc unit shown in FIG.
FIG. 3 is a perspective view of an elastic member included in the brake disc unit shown in FIG. 1. FIG.
FIG. 4 is a vertical cross-sectional view of the elastic member shown in FIG.
FIG. 5 is a cross-sectional view showing a part of the brake disc unit according to the second embodiment.
FIG. 6 is a vertical cross-sectional view of an elastic member included in the brake disc unit shown in FIG.
FIG. 7 is a vertical cross-sectional view showing a modified example of the elastic member shown in FIGS. 3 and 4.
FIG. 8 is a vertical cross-sectional view showing a modified example of the elastic member shown in FIG.
FIG. 9 is a graph showing the relationship between the flange height of the elastic member according to the embodiment and the maximum stress generated in the fastening member.
Embodiment for carrying out the invention
[0013]
The mounting structure according to the embodiment is a structure in which an annular brake disc is mounted on the mounted member. The attached member may be a wheel of a railroad vehicle, or may be a disc body fixed to an axle of the railroad vehicle. The mounting structure includes a fastening member and an elastic member. The fastening member fastens the brake disc to the attached member. The fastening member has a bolt and a nut. The bolt includes a shaft portion. The shaft portion penetrates the brake disc and the mounted member. The nut is attached to the end of the shaft on the brake disc side. The elastic member is placed between the nut and the brake disc. The elastic member has a cylindrical member body and a first flange. A shaft portion is inserted into the member body. The first flange is connected to the end on the nut side of both ends of the member body. The first flange projects outward from the member body and comes into contact with the outer peripheral portion of the nut (first configuration).
[0014]
In the first configuration, an elastic member having a member body and a first flange is arranged between the nut of the fastening member and the brake disc. This elastic member is interposed between the nut attached to the shaft portion of the bolt and the brake disc, and absorbs the deformation of the fastening member due to the deformation of the brake disc. That is, when the brake disc is deformed by frictional heat between the brake disc and the brake lining and a compressive load is applied to the elastic member, the first flange is bent and the elastic member is greatly deformed as a whole. As a result, the deformation of the fastening member due to the deformation of the brake disc is absorbed by the elastic member, so that the load on the fastening member can be reduced.
[0015]
In the first configuration, the nut of the fastening member is in contact with the first flange of the elastic member. The first flange projects outward from the tubular member body and comes into contact with the outer peripheral portion of the nut. Therefore, in the fastening member, the inner peripheral portion of the nut, that is, the connecting portion between the nut and the shaft portion of the bolt is not restrained by the elastic member, and the nut and the shaft portion are allowed to be deformed. Therefore, the stress generated in the fastening member is relaxed, and the load on the fastening member can be reduced.
[0016]
As described above, according to the first configuration, in the brake disc for a railway vehicle to be fastened to the attached member by the fastening member, the load on the fastening member can be reduced, so that the fatigue strength of the fastening member is improved. Can be made to.
[0017]
In the above mounting structure, the outer peripheral surface of the elastic member can include the first curved portion in the vertical cross-sectional view of the elastic member. The first curved portion connects the member main body and the first flange (second configuration).
[0018]
According to the second configuration, the member main body and the first flange are connected by the first curved portion on the outer peripheral surface of the elastic member. Therefore, when a compressive load acts on the elastic member and the first flange bends, it is possible to prevent stress concentration from occurring at the base portion (connection portion with the member main body) of the first flange.
[0019]
In the above mounting structure, the elastic member can further have a second flange. The second flange is connected to the end of both ends of the member body opposite to the first flange. The second flange projects outward from the member body and comes into contact with the brake disc (third configuration).
[0020]
According to the third configuration, in the elastic member, first and second flanges are provided at both ends of the cylindrical member body, respectively. As a result, when the compressive load due to the deformation of the brake disc acts on the elastic member, the second flange is bent in addition to the first flange, so that the elastic member is deformed more greatly. Therefore, the deformation of the fastening member due to the deformation of the brake disc can be more reliably absorbed by the elastic member, and the load on the fastening member can be further reduced.
[0021]
In the third configuration, the outer peripheral surface of the elastic member can include the second curved portion in the vertical cross-sectional view of the elastic member. The second curved portion connects the member main body and the second flange (fourth configuration).
[0022]
According to the fourth configuration, the member main body and the second flange are connected by the second curved portion on the outer peripheral surface of the elastic member. Therefore, when a compressive load acts on the elastic member and the second flange bends, it is possible to prevent stress concentration from occurring at the base portion (connection portion with the member main body) of the second flange.
[0023]
The brake disc unit according to the embodiment is a brake disc unit for railway vehicles. The brake disc unit includes the brake disc, the mounted member, and a mounting structure of any one of the first to fourth configurations.
[0024]
Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In each figure, the same or equivalent configurations are designated by the same reference numerals, and the same description is not repeated.
[0025]

[Brake disc unit configuration]
First, the first embodiment of the present disclosure will be described. FIG. 1 is a plan view of the brake disc unit 100 according to the first embodiment. The brake disc unit 100 is used for railway vehicles.
[0026]
As shown in FIG. 1, the brake disc unit 100 includes a brake disc 10, a mounted member 20, and a plurality of mounting structures 30.
[0027]
The brake disc 10 forms an annular shape. The brake disc 10 is attached to the attached member 20 by the attachment structure 30. The mounting structure 30 is arranged along the circumferential direction of the brake disc 10.
[0028]
In the present embodiment, the attached member 20 is a wheel of a railway vehicle. The attached member 20 may be a disc body fixed to the axle of a railway vehicle. The brake disc 10 is provided so as to be substantially coaxial with the attached member 20. The brake disc 10 is arranged on both sides of the attached member 20.
[0029]
The materials of the brake disc 10 and the attached member 20 are particularly limited. It is not something that will be done. As the material of the brake disc 10, for example, steel, aluminum composite material, or the like, which is generally used for the brake disc, can be adopted. As the material of the attached member 20, a material generally used for wheels or discs for railway vehicles can be adopted.
[0030]
FIG. 2 is a sectional view taken along line II-II of the brake disc unit 100 shown in FIG. In FIG. 2, only one of the brake discs 10 mounted on both sides of the mounted member 20 is shown, and the other is omitted.
[0031]
With reference to FIG. 2, the brake disc 10 has a front surface 101 and a back surface 102. The surface 101 is an outward surface in the thickness direction of the brake disc unit 100. The surface 101 is a sliding surface on which a brake lining (not shown) is pressed. The back surface 102 faces the side surface of the attached member 20. When the brake disc 10 has a plurality of longitudinal fins extending in the radial direction, the back surface 102 is the top surface of the vertical fins.
[0032]
The thickness direction of the brake disc unit 100 is the stacking direction of the brake disc 10 and the mounted member 20, and coincides with each thickness direction of the brake disc 10 and the mounted member 20. Hereinafter, the thickness direction of the brake disc unit 100, the brake disc 10, or the attached member 20 may be simply referred to as the thickness direction. Further, the radial direction of the brake disc unit 100, the brake disc 10, or the mounted member 20 may be simply referred to as the radial direction.
[0033]
The brake disc 10 includes a plurality of fastening holes 103. The plurality of fastening holes 103 are arranged at intervals along the circumferential direction of the brake disc 10. Each of the fastening holes 103 is a through hole that penetrates the brake disc 10 in the thickness direction.
[0034]
Each fastening hole 103 includes a large diameter portion 1031 and a small diameter portion 1032. The diameter of the large diameter portion 1031 is larger than the diameter of the small diameter portion 1032. The large diameter portion 1031 and the small diameter portion 1032 are arranged in this order from the front surface 101 to the back surface 102 of the brake disc 10. The large diameter portion 1031 opens to the surface 101. The small diameter portion 1032 opens on the back surface 102.
[0035]
The attached member 20 has a plurality of fastening holes 203. The plurality of fastening holes 203 are formed in the attached member 20 corresponding to the plurality of fastening holes 103 of the brake disc 10. The brake disc 10 is attached to both sides of the attached member 20. Therefore, in the thickness direction, the fastening hole 103 of one brake disc 10, the fastening hole 203 of the attached member 20, and the fastening hole of the other brake disc (not shown) are arranged in this order.
[0036]
The mounting structure 30 is a structure for mounting the brake disc 10 to the mounted member 20. The mounting structure 30 is provided for each fastening hole 103 of the brake disc 10. The mounting structure 30 includes a fastening member 301 and an elastic member 302.
[0037]
The fastening member 301 fastens the brake disc 10 to the attached member 20. The fastening member 301 is inserted into the fastening hole 103 of the brake disc 10 and the fastening hole 203 of the attached member 20. The fastening member 301 has a nut 3011 and a bolt 3012.
[0038]
The nut 3011 is housed in the fastening hole 103 of the brake disc 10. More specifically, the nut 3011 is arranged in the large diameter portion 1031 of the fastening hole 103.
[0039]
The bolt 3012 includes the shaft portion 3012a. The shaft portion 3012a extends from the nut 3011 toward the mounted member 20 side. The shaft portion 3012a extends through the brake disc 10 and the attached member 20 in the thickness direction.
[0040]
The shaft portion 3012a is inserted into the fastening hole 103 of the brake disc 10 and the fastening hole 203 of the attached member 20. More specifically, the shaft portion 3012a is inserted into the fastening hole 103 of the brake disc 10, the fastening hole 203 of the attached member 20, and the fastening hole (not shown) of another brake disc.
[0041]
A nut 3011 is attached to one end of the shaft portion 3012a. The bolt 3012 has a head (not shown) at the other end of the shaft portion 3012a. The shaft portion 3012a has at least a threaded portion at the end on the nut 3011 side. The nut 3011 has a threaded portion corresponding to the threaded portion of the shaft portion 3012a. The threaded portion of the shaft portion 3012a fits into the threaded portion of the nut 3011.
[0042]
The elastic member 302 is arranged between the nut 3011 of the fastening member 301 and the brake disc 10. The elastic member 302 is arranged so as to overlap the fastening hole 103 of the brake disc 10. In this embodiment, the elastic member 302 is housed in the fastening hole 103.
[0043]
The elastic member 302 includes a top surface 3021, a bottom surface 3022, and an outer peripheral surface 3023. The top surface 3021 faces the seat surface of the nut 3011 of the fastening member 301. The bottom surface 3022 faces the bottom surface of the large diameter portion 1031 of the fastening hole 103. The outer peripheral surface 3023 faces the inner wall surface of the large diameter portion 1031. The outer peripheral surface 3023 connects the outer peripheral edge of the top surface 3021 and the outer peripheral edge of the bottom surface 3022.
[0044]
The elastic member 302 has a member main body 3024 and flanges 3025 and 3026 protruding outward from the member main body 3024.
[0045]
The member body 3024 has a cylindrical shape. The shaft portion 3012a of the fastening member 301 is inserted into the member main body 3024.
[0046]
The flange 3025 is provided at both ends of the member main body 3024 at the end of the fastening member 301 on the nut 3011 side. The flange 3025 extends outward from the member body 3024. The flange 3025 approaches the bearing surface of the nut 3011 toward the outer peripheral side of the elastic member 302. The flange 3025 contacts the outer peripheral portion of the bearing surface of the nut 3011.
[0047]
The flange 3026 is provided at both ends of the member main body 3024 on the opposite side of the flange 3025. The flange 3026 extends from the member body 3024 to the outer peripheral side of the elastic member 302. The flange 3026 approaches the bottom surface of the large diameter portion 1031 of the fastening hole 103 toward the outer peripheral side of the elastic member 302. The flange 3026 contacts the outer peripheral portion of the bottom surface of the large diameter portion 1031.
[0048]
Hereinafter, the elastic member 302 will be described in more detail with reference to FIGS. 3 and 4.
[0049]
FIG. 3 is a perspective view of the elastic member 302. FIG. 4 is a cross-sectional view of the elastic member 302 cut along a plane including the central axis X. Hereinafter, in the elastic member 302, a cross section cut in a plane including the central axis X is referred to as a vertical cross section, and a cross section cut in a plane orthogonal to the central axis X is referred to as a cross section. Further, in the elastic member 302, the direction in which the central axis X extends is referred to as an axial direction, the direction orthogonal to the central axis X is referred to as a radial direction or a lateral direction, the top surface 3021 side is referred to as an upper surface, and the bottom surface 3022 side is referred to as a lower surface.
[0050]
With reference to FIGS. 3 and 4, the elastic member 302 has, for example, a substantially cylindrical shape. In the present embodiment, the outer diameter of the elastic member 302 decreases from both ends in the axial direction toward the center. That is, as shown in FIG. 4, the elastic member 302 has a maximum outer diameter ODa at both ends in the axial direction and a minimum outer diameter ODb at the central portion in the axial direction. The elastic member 302 has a substantially constant inner diameter ID over the entire axial direction.
[0051]
The maximum outer diameter ODA of the elastic member 302 is equal to or less than the diameter of the seat surface of the nut 3011 (FIG. 2) of the fastening member 301. When the shape of the seat surface of the nut 3011 is not circular, the maximum outer diameter ODA of the elastic member 302 is equal to or less than the transfer length of the seat surface of the nut 3011. The transfer length of the seat surface of the nut 3011 means the maximum dimension of the seat surface of the nut 3011. When the shape of the elastic member 302 is a polygonal cylinder or the like, the maximum lateral dimension of the elastic member 302 is set to be equal to or less than the diameter of the seat surface of the nut 3011 or the transfer length.
[0052]
In the elastic member 302, the member body 3024 and the flanges 3025 and 3026 are integrally formed. In FIG. 4, the boundary between the member main body 3024 and the flanges 3025 and 3026 is shown by the alternate long and short dash line B. Of the elastic member 302, the cylindrical portion surrounded by the alternate long and short dash line B is the member main body 3024, and the portion projecting to the outside of the cylindrical portion is the flange 3025, 3026. The member body 3024 has a substantially constant outer diameter ODb and inner diameter ID over the entire axial direction. Each of the flanges 3025 and 3026 has a substantially annular shape and has an outer diameter ODA.
[0053]
The flange 3025 is connected to the upper part of the member main body 3024. The flange 3025 projects outward of the member body 3024 in the radial direction of the elastic member 302 and extends slightly upward. The top surface 3025a of the flange 3025 constitutes the top surface 3021 of the elastic member 302 together with the top surface 3024a of the member main body 3024. The top surface 3024a of the member body 3024 rises outward in the radial direction of the elastic member 302. The top surface 3025a of the flange 3025 is continuous with the top surface 3024a of the member body 3024 and rises outward in the radial direction of the elastic member 302. That is, the top surface 3021 of the elastic member 302 is a tapered surface that gently rises and slopes from the inside to the outside in the radial direction. However, the shape of the top surface 3021 is not limited to this. On the top surface 3021, the outer portion in the radial direction may be located above the inner portion, and for example, even if the outer portion (outer peripheral portion) in the radial direction is provided with a convex portion protruding upward. good.
[0054]
The flange 3026 is connected to the lower part of the member main body 3024. The flange 3026 projects outward of the member body 3024 in the radial direction of the elastic member 302 and extends slightly downward. The bottom surface 3026b of the flange 3026 constitutes the bottom surface 3022 of the elastic member 302 together with the bottom surface 3024b of the member body 3024. The bottom surface 3024b of the member body 3024 descends outward in the radial direction of the elastic member 302. The bottom surface 3026b of the flange 3026 is continuous with the bottom surface 3024b of the member body 3024 and descends outward in the radial direction of the elastic member 302. That is, the bottom surface 3022 of the elastic member 302 is a tapered surface that gently descends from the inside to the outside in the radial direction. However, the shape of the bottom surface 3022 is not limited to this. On the bottom surface 3022, the outer portion in the radial direction may be located below the inner portion, and for example, the outer portion (outer peripheral portion) in the radial direction may be provided with a convex portion protruding downward. ..
[0055]
The outer peripheral surface 3023 of the elastic member 302 includes curved portions 3023a and 3023b in a vertical cross-sectional view of the elastic member 302. The curved portion 3023a is arranged on the upper part of the outer peripheral surface 3023. The curved portion 3023a smoothly connects the member main body 3024 and the upper flange 3025. The curved portion 3023b is arranged at the lower part of the outer peripheral surface 3023. The curved portion 3023b smoothly connects the member main body 3024 and the lower flange 3026.
[0056]
In the present embodiment, the outer peripheral surface 3023 is composed of only curved portions 3023a and 3023b having the same radius of curvature in the vertical cross-sectional view of the elastic member 302. That is, the outer peripheral surface 3023 is a single arc surface that is concave inward in the radial direction of the elastic member 302 as a whole. However, the outer peripheral surface 3023 does not have to be composed of only the curved portions 3023a and 3023b, and may include a straight portion in a vertical cross-sectional view of the elastic member 302. Further, the radii of curvature of the curved portions 3023a and 3023b may be different from each other. Each of the curved portions 3023a and 3023b may be a single arc as in the present embodiment, but may be composed of a plurality of arcs having different radii of curvature.
[0057]
The flanges 3025 and 3026 have flange widths Wa and Wb, respectively. The flange width Wa is an axial dimension of the outer peripheral edge portion of the flange 3025. The flange width Wb is an axial dimension of the outer peripheral edge portion of the flange 3026. Flange widths Wa and Wb are It may be, for example, 2 mm to 4 mm, although it depends on the usage conditions of the brake disc unit 100 (FIG. 2).
[0058]
The flanges 3025 and 3026 have a flange height H. In the present embodiment, the flanges 3025 and 3026 have the same flange height H, but may have different flange heights from each other. The flange height H is the protrusion height of the flanges 3025 and 3026 to the outside of the member main body 3024, and is the maximum dimension of the flanges 3025 and 3026 in the radial direction of the elastic member 302. The flange height H is preferably 5 mm or less, although it depends on the usage conditions of the brake disc unit 100 (FIG. 2) and the like. By setting the flange height H to 5 mm or less, the stress generated in the fastening member 301 (FIG. 2) can be reliably reduced. The flange height H is preferably 1 mm or more so that the spring constant of the elastic member 302 does not increase.
[0059]
The wall thickness of the member body 3024, that is, the difference between the outer diameter ODb and the inner diameter ID can be, for example, 5 mm to 15 mm. Further, for example, the maximum length La of the elastic member 302 in the axial direction may be 6 mm to 20 mm, and the minimum length Lb may be 2 mm to 16 mm.
[0060]
[effect]
In the brake disc unit 100 according to the present embodiment, the elastic member 302 is arranged between the nut 3011 of the fastening member 301 and the brake disc 10. When a compressive load due to thermal deformation of the brake disc 10 acts on the elastic member 302, in the elastic member 302, the flanges 3025 and 3026 bend toward the center in the axial direction, and the fastening member 301 due to the deformation of the brake disc 10 Deformation is absorbed. Therefore, the load on the fastening member 301 can be reduced, and the fatigue strength of the fastening member 301 can be improved.
[0061]
The elastic member 302 comes into contact with the outer peripheral portion of the nut 3011 of the fastening member 301 by the flange 3025. The elastic member 302 does not come into contact with the inner peripheral portion of the nut 3011. Therefore, in the fastening member 301, the connection portion between the nut 3011 and the shaft portion 3012a of the bolt 3012 is not restrained by the elastic member 302, and the nut 3011 and the shaft portion 3012a are allowed to be deformed. Therefore, the stress generated in the fastening member 301 is relaxed, and the load on the fastening member 301 can be reduced.
[0062]
The mounting structure 30 according to the present embodiment is adopted for a centrally fastened type brake disc 10 in which a fastening portion is provided in the center of the surface (sliding surface) 101. In the central fastening type brake disc 10, the nut 3011 of the fastening member 301 and the elastic member 302 are housed in the large diameter portion 1031 of the fastening hole 103. Therefore, the maximum outer diameter ODA of the elastic member 302 is inevitably equal to or less than the diameter of the seat surface of the nut 3011 or the transfer length. When there is such a restriction on the outer diameter, it is difficult to realize a low spring constant with a general disc spring, so that it may not be possible to sufficiently reduce the load on the fastening member 301. On the other hand, since the elastic member 302 of the present embodiment has flanges 3025 and 3026 at both ends in the axial direction, the amount of deformation is large and the spring constant is low as compared with a general disc spring having the same outer diameter. Can have. Therefore, even in the central fastening type brake disc 10 in which the outer diameter of the elastic member 302 is restricted, the load on the fastening member 301 can be sufficiently reduced.
[0063]
In the case of the central fastening type brake disc 10, since the fastening member 301 is housed in the fastening hole 103, there are restrictions on the dimensions of the fastening member 301, and it is difficult to increase the strength of the fastening member 301 itself. Further, in the centrally fastened type brake disc 10, since the fastening hole 103 is arranged on the surface (sliding surface) 101 where heat is input, the load on the fastening member 301 due to the thermal deformation of the brake disc 10 increases. Tend. Therefore, it is particularly preferable that the mounting structure 30 according to the present embodiment is applied to the centrally fastened type brake disc 10. That is, according to the mounting structure 30, since the elastic member 302 can be greatly deformed by the deflection of the flanges 3025 and 3026, the thermal deformation of the brake disc 10 is absorbed and the load on the fastening member 301 is prevented from increasing. Can be done. However, the mounting structure 30 can also be applied to brake discs other than the centrally fastened type.
[0064]
In this embodiment, flanges 3025 and 3026 are provided at both ends of the elastic member 302 in the axial direction, respectively. That is, the elastic member 302 is formed so as to be substantially vertically symmetrical. Therefore, when assembling the brake disc unit 100, the operator does not need to be aware of the upper and lower sides of the elastic member 302, and workability can be improved.
[0065]
In the present embodiment, the elastic member 302 includes curved portions 3023a and 3023b in the outer peripheral surface 3023 in a vertical cross-sectional view. The curved portions 3023a and 3023b smoothly connect the flanges 3025 and 3026 and the member main body 3024. Therefore, when the flanges 3025 and 3026 are bent by the compressive load, it is possible to suppress the occurrence of stress concentration at the base of the flanges 3025 and 3026, and it is possible to prevent the flanges 3025 and 3026 from being damaged.
[0066]

Next, the second embodiment of the present disclosure will be described. FIG. 5 is a cross-sectional view showing a mounting structure 40 of the brake disc unit 200 according to the second embodiment. FIG. 6 is a vertical sectional view of the elastic member 402 included in the mounting structure 40. The brake disc unit 200 according to the second embodiment is different from the brake disc unit 100 (FIG. 2) according to the first embodiment in the shape of the elastic member 402 of the mounting structure 40.
[0067]
As shown in FIG. 5, the elastic member 402 includes a top surface 4021, a bottom surface 4022, and an outer peripheral surface 4023, as in the first embodiment. The elastic member 402 has a cylindrical member body 4024 and a flange 4025 on the top surface 4021 side, as in the first embodiment. Unlike the first embodiment, the elastic member 402 does not have a flange on the bottom surface 4022 side.
[0068]
The flange 4025 is provided at the end of the fastening member 301 on the nut 3011 side of both ends of the member main body 4024. The flange 4025 extends from the member main body 4024 to the outer peripheral side and the nut 3011 side of the elastic member 402, and comes into contact with the outer peripheral portion of the seat surface of the nut 3011.
[0069]
With reference to FIG. 6, the flange 4025 on the upper part of the elastic member 402 has the same configuration as the flange 3025 (FIGS. 3 and 4) of the first embodiment. The flange 4025 projects outward of the member body 4024 in the radial direction of the elastic member 402. The top surface 4025a of the flange 4025 constitutes a tapered top surface 4021 together with the top surface 4024a of the member main body 4024. On the other hand, since there is no flange at the bottom of the elastic member 402, the bottom surface 4022 of the elastic member 402 is composed of only the bottom surface of the member body 4024. The bottom surface 4022 is an annular surface substantially parallel to the radial direction of the elastic member 402.
[0070]
The outer peripheral surface 4023 includes a curved portion 4023a and a straight portion 4023c in a vertical cross-sectional view of the elastic member 402. The curved portion 4023a is arranged on the upper part of the outer peripheral surface 4023. The curved portion 4023a smoothly connects the member main body 4024 and the flange 4025. The curved portion 4023a may be a single arc, or may be composed of a plurality of arcs having different radii of curvature. The straight portion 4023c extends straight from the curved portion 4023a toward the bottom surface 4022 along the axial direction of the elastic member 402.
[0071]
As described above, in the present embodiment, the flange 4025 is provided on only one of both ends of the elastic member 402 in the axial direction. Therefore, when the brake disc 10 is deformed and a compressive load is applied to the elastic member 402, the flange 4025 bends toward the center in the axial direction, and the deformation of the brake disc 10 is absorbed. Therefore, the load on the fastening member 301 can be reduced.
[0072]
The elastic member 402 is in contact with the outer peripheral portion of the nut 3011 of the fastening member 301 by the flange 4025, and is not in contact with the inner peripheral portion of the nut 3011. The elastic member 402 does not restrain the connection portion between the nut 3011 and the shaft portion 3012a of the bolt 3012, and allows the nut 3011 and the shaft portion 3012a to be deformed. Therefore, the stress generated in the fastening member 301 can be relaxed, and the load on the fastening member 301 can be reduced.
[0073]
As described above, also in the present embodiment, the load on the fastening member 301 can be reduced and the fatigue strength of the fastening member 301 can be improved as in the first embodiment.
[0074]
Although the embodiment according to the present disclosure has been described above, the present disclosure is not limited to the above embodiment, and various changes can be made as long as the purpose is not deviated.
[0075]
For example, in the first embodiment, the elastic member 302 has a substantially constant inner diameter ID over the entire axial direction. However, the inner diameter ID of the elastic member 302 does not have to be constant.
[0076]
FIG. 7 is a vertical cross-sectional view of the elastic member 502 according to the modified example of the elastic member 302 (FIG. 4) in the first embodiment. As shown in FIG. 7, the inner and outer diameters of the elastic member 502 become smaller from both ends in the axial direction toward the center. That is, the elastic member 502 has a maximum inner diameter IDa at both ends in the axial direction and a minimum inner diameter IDb at the central portion in the axial direction. Further, the elastic member 502 has a maximum outer diameter ODa at both ends in the axial direction and a minimum outer diameter ODb at the central portion in the axial direction, similarly to the elastic member 302 in the first embodiment.
[0077]
In the elastic member 502, one flange 5025 extends outward and upward from the member main body 5024. Therefore, the top surface 5025a of the flange 5025 comes into contact with the outer peripheral portion of the seat surface of the nut 3011 in the brake disc unit 100 shown in FIG. In the example shown in FIG. 7, the top surface 5025a is substantially parallel to the radial direction of the elastic member 502. However, as in the first embodiment, the top surface 5025a may be inclined so as to rise toward the outside in the radial direction of the elastic member 502.
[0078]
The other flange 5026 extends outward and downward from the member body 5024. Therefore, the bottom surface 5026b of the flange 5026 comes into contact with the outer peripheral portion of the bottom surface of the large diameter portion 1031 of the fastening hole 103 in the brake disc unit 100 shown in FIG. In the example shown in FIG. 7, the bottom surface 5026b is substantially parallel to the radial direction of the elastic member 502. However, the bottom surface 5026b may be inclined so as to descend toward the outside in the radial direction of the elastic member 502 as in the first embodiment.
[0079]
The member main body 5024 and the flanges 5025 and 5026 are smoothly connected by curved portions 5023a and 5027a provided on the outer peripheral surface 5023 and the inner peripheral surface 5027 of the elastic member 502, respectively.
[0080] [0080]
Further, for example, in each of the above embodiments, the flanges 3025, 4025 of the elastic members 302, 402 extend outward from the member main bodys 302, 4024. However, the flanges 3025 and 4025 are not limited to those described in the above embodiments, as long as they can protrude from the member main body 3024 and 4024 and come into contact with the outer peripheral portion of the nut 3011.
[0081]
FIG. 8 is a vertical cross-sectional view of the elastic member 602 according to the modified example of the elastic member 402 (FIG. 6) in the second embodiment. As shown in FIG. 8, in the elastic member 602, the flange 6025 projects outward from the member body 6024. The flange 6025 extends substantially in the axial direction of the member body 6024. Since the flange 6025 is arranged outside the member main body 6024 in the radial direction of the elastic member 602, it comes into contact with the outer peripheral portion of the seat surface of the nut 3011 in the brake disc unit 100 shown in FIG. In the example shown in FIG. 8, the flange 6025 The top surface 6025a is substantially parallel to the radial direction of the elastic member 602. However, as in the second embodiment, the top surface 6025a may be inclined so as to rise toward the outside in the radial direction of the elastic member 602. The member main body 6024 and the flange 6025 are smoothly connected by curved portions 6023a and 6027a provided on the outer peripheral surface 6023 and the inner peripheral surface 6027 of the elastic member 602, respectively.
[0082]
In the brake disc units 100 and 200 according to each of the above embodiments, the brake disc (not shown) mounted on the side opposite to the brake disc 10 shown in FIGS. 2 and 5 with respect to the mounted member 20, and the head of the bolt 3012. Any of the elastic members 302, 402, 502, and 602 can be arranged between the elastic members 302, 402, 502, and 602 (not shown). In the elastic member 402 or the elastic member 602, the flanges 402, 6025 may be arranged toward the head of the bolt 3012, but the flanges 402, 6025 may be arranged toward the brake disc side. That is, the elastic member 402 or the elastic member 602 may be in contact with the inner peripheral portion of the seat surface of the head of the bolt 3012 on the bottom surface. A general disc spring may be arranged between the brake disc and the head of the bolt 3012 instead of the elastic members 302, 402, 502, 602.
Example
[0083]
Hereinafter, the present disclosure will be described in more detail by way of examples. However, the present disclosure is not limited to the following examples.
[0084]
A model having a centrally fastened type brake disc for the Shinkansen and a mounting structure for mounting this brake disc to the mounted member was produced and analyzed by the finite element method (FEM analysis). The model has the same configuration as the brake disc unit 100 shown in FIG.
[0085]
In the FEM analysis, the maximum stress generated in the fastening member 301 was calculated assuming that the stop brake was applied while the railway vehicle was traveling at 360 km / h. In the FEM analysis, after keeping the flange widths Wa and Wb of the elastic member 302 constant, the flange height H is changed to 2.3 mm, 2.9 mm, and 4.8 mm, and the maximum stress is calculated for each flange height H. did.
[0086]
FIG. 9 is a graph showing the relationship between the flange height H and the maximum stress generated in the fastening member 301. In the graph of FIG. 9, the maximum stress when a disc spring is used instead of the elastic member 302 is shown by a broken line.
[0087]
As shown in FIG. 9, in the mounting structure 30 for mounting the brake disc 10 to the mounted member 20, when the elastic member 302 having the flanges 3025 and 3026 is used, the fastening member is compared with the case where the disc spring is used. The maximum stress generated in 301 becomes smaller. That is, it can be seen that the load on the fastening member 301 can be reduced by the elastic member 302.
[0088]
From this example, it was confirmed that when the flange height H is 5 mm or less, the maximum stress generated in the fastening member 301 is smaller than when the disc spring is used. Therefore, in order to surely reduce the load on the fastening member 301, it can be said that it is preferable that the flange height H is 5 mm or less. From the viewpoint of realizing a low spring constant, the flange height H is preferably 1 mm or more.
Description of the sign
[0089]
100,200: Brake disc unit
10: Brake disc
20: Attached member
30, 40: Mounting structure
301: Fastening member
3011: Nut
3012: Bolt
3012a: Shaft
302, 402, 502, 602: Elastic member
3023, 4023: Outer peripheral surface
3023a, 3023b, 4023a, 5023a, 6023a: Curved part
3024, 4024, 5024, 6024: Member body
3025, 3026, 4025, 5025, 5026, 6025: Flange
The scope of the claims
[Claim 1]
A structure in which an annular brake disc is attached to a wheel of a railroad vehicle or a member to be attached which is a disc body fixed to the axle of the railroad vehicle.
A fastening member for fastening the brake disc to the attached member, a bolt including the brake disc and a shaft portion penetrating the attached member, and a nut attached to the end portion of the shaft portion on the brake disc side. And the fastening member having
An elastic member placed between the nut and the brake disc,
Equipped with
The elastic member is
The tubular member body into which the shaft is inserted and
A first flange that is connected to both ends of the member body on the nut side, projects outward from the member body, and comes into contact with the outer peripheral portion of the nut.
Has a mounting structure.
[Claim 2]
The mounting structure according to claim 1
The outer peripheral surface of the elastic member is a mounting structure including a first curved portion connecting the member body and the first flange in a vertical cross-sectional view of the elastic member.
[Claim 3]
The mounting structure according to claim 1 or 2,
The elastic member is further
A second flange that is connected to both ends of the member body on the opposite side of the first flange and protrudes outward from the member body to come into contact with the brake disc.
Has a mounting structure.
[Claim 4]
The mounting structure according to claim 3
The outer peripheral surface of the elastic member is a mounting structure including a second curved portion connecting the member body and the second flange in a vertical cross-sectional view of the elastic member.
[Claim 5]
It is a brake disc unit for railway vehicles,
With an annular brake disc,
The attached member, which is a disc body fixed to the wheel of the railway vehicle or the axle of the railway vehicle,
The mounting structure according to any one of claims 1 to 4 and
Brake disc unit.