Technical field
[0001]The present invention relates to a front axle beam, in particular for example, to front axle beam used in a vehicle such as a lorry or a bus.
BACKGROUND
[0002]Front axle beam (hereinafter may be referred to as "front axle") is mainly used to support the vehicle body front wheels of the vehicle are mounted. The front axle, as a component for transmitting the load of the vehicle body to the left and right front wheels, and, as a structural safety components, is important. The front axle, by securing a front wheel of the steering performance while securing the wheel in position, responsible for the running stability. Further, during braking, the front axle is a transmission path for transmitting the braking forces of the wheels. In this way, the front axle, running property, a steering resistance, and strongly affect parts in braking performance. Since required high rigidity for the front axle, the front axle weight is greater. On the other hand, from the viewpoint of fuel efficiency, weight reduction of the front axle is required.
[0003]
　JP 2003-285771 (Patent Document 1) proposes a front axle which can reduce the aerodynamic resistance during vehicle travel. The invention described in Patent Document 1 is aimed at improving fuel economy by reducing the aerodynamic drag.
[0004]
　JP-10-119504 (Patent Document 2), front axle including a front axle body formed by light alloy such as aluminum alloy, and a reinforcing member which tensile stress is formed in the material higher than the light alloy It discloses.
[0005]
　JP-9-175103 (Patent Document 3) discloses a front axle which is formed by aluminum alloy casting was cast steel at a specific site. The invention described in Patent Documents 2 and 3 reduce the weight by using a light alloy such as aluminum alloy.
CITATION
Patent Document
[0006]
Patent Document 1: JP 2003-285771 Patent Publication
Patent Document 2: JP-A 10-119504 JP-
Patent Document 3: JP-A 9-175103 JP
Summary of the Invention
Problems that the Invention is to Solve
[0007]
　As the structure of the front axle, lightweight and highly rigid construction is demanded. That is, the fuel consumption in view of the first needs, it is desired front axle is lightweight. The request from the motion performance of the vehicle to be advanced as the second needs, namely, achieving the safety stop of the vehicle is demanded by braking from higher running speed. Therefore, the increase in stiffness corresponds to an increase in applied load on the front axle is required.
[0008]
　The weight reduction and high rigidity is these two needs for the front axle, generally conflicting requirements on. Currently, new front axle that can respond as much as possible to the conflicting request is being sought.
[0009]
　Front axle that can achieve both weight reduction and high rigidity can be utilized in many cases of different design scene showing a typical example as follows.
(1) Since the stiffness of the front axle is efficiently enhanced shape, the same rigidity as the conventional, more or lighter front axle can be realized in a more compact front axle. That is, it is possible to reduce the weight of the front axle of the same rigidity.
(2) an improvement in rigidity of the front axle can be achieved with little increase of the same size and weight as conventional or size and weight. That is, it highly rigid and lightweight front axle.
[0010]
　On the other hand, around the front axle, the moving parts of the engine and steering are arranged densely. Therefore, the front axle, is also required to fit into tight spaces so as not to interfere with these peripheral parts. Therefore, new technologies capable of enhancing the rigidity without increasing the size of the front axle, in particular sought.
[0011]
　In such circumstances, an object of the present invention is to provide a new front axle beam capable of increasing the rigidity in a compact and lightweight.
Means for Solving the Problems
[0012]
　Front axle beam according to an embodiment of the present invention includes a beam portion, and the king pin mounting portion in the longitudinal ends of the beam portion. Beam portion includes a first flange portion, a second flange portion opposite the first flange portion, a web portion connecting standing the first flange portion and the second flange portion. Web portion, in cross-section of the beam portion, a first inclined portion inclined in one direction relative to the vehicle height direction, in other cross-section of the beam portion, opposite to the first direction relative to the vehicle height direction comprising a second inclined portion inclined in direction.
The invention's effect
[0013]
　According to the present invention, the front axle beam capable of increasing the rigidity is obtained. By using the front axle beam, it is possible to weight reduction and performance improvement of the vehicle. In the present invention, to improve the rigidity by the use of a web portion having a specific shape. Therefore, it is possible to improve the rigidity without increasing the overall size of the front axle, which is determined by the outer shape of the flange.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014]
[1] Figure 1 is a perspective view showing a front axle of the first embodiment schematically.
FIG. 2 is a perspective view schematically showing a tilt change of the front axle as shown in FIG.
FIG. 3 shows a front view when viewing the front axle as shown in FIG. 1 from the front schematically.
[Figure 4A] Figure 4A is a diagram schematically showing an example of a horizontal cross section of the inclined change portion shown in FIG.
[Figure 4B] Figure 4B is a diagram schematically showing another example of a horizontal cross section of the inclined change portion shown in FIG.
[Figure 4C] Figure 4C is a diagram schematically showing another example of a horizontal cross section of the inclined change portion shown in FIG.
[Figure 5A] Figure 5A is a view showing a cross section taken along line VA-VA in FIG. 4A ~ Figure 4C schematically.
[Figure 5B] Figure 5B is a view showing a cross section taken along a line VB-VB in FIG. 4A ~ Figure 4C schematically.
[Figure 5C] Figure 5C is a view showing a cross section taken along a line VC-VC in FIG. 4A ~ Figure 4C schematically.
FIG. 6 is a schematic diagram for explaining a brace structure of the inclined change portion.
[7] FIG. 7 is a diagram showing an example of a change in the angle X of the inclination of the inclined change portion.
[8] FIG. 8 is a schematic view for explaining an arch shape of the inclined change portion.
[9] FIG. 9 is a schematic diagram showing a draft of the flange portion.
[10] FIG 10 is a perspective view showing a front axle of the second embodiment schematically.
FIG 11A] FIG 11A with respect the front axle of the second embodiment, a diagram schematically showing an example of a horizontal cross section of the inclined change portion.
FIG 11B] FIG 11B, with respect to the front axle of the second embodiment, which is a diagram schematically showing another example of a horizontal cross section of the inclined change portion.
FIG 11C] FIG 11C, with respect to the front axle of the second embodiment, which is a diagram schematically showing another example of a horizontal cross section of the inclined change portion.
FIG 12A] FIG 12A is a view showing a cross section taken along a line XIIA-XIIA in FIG. 11A ~ FIG 11C schematically.
[Figure 12B] Figure 12B is a view showing a cross section taken along a line XIIB-XIIB of FIG. 11A ~ FIG 11C schematically.
[FIG. 12C] FIG 12C is a view showing a cross section taken along line XIIC-XIIC of FIG. 11A ~ FIG 11C schematically.
FIG 13A] FIG 13A with respect the front axle of the third embodiment, a diagram schematically showing an example of a horizontal cross section of the inclined change portion.
FIG 13B] FIG 13B, with respect to the front axle of the third embodiment and illustrating schematically another example of the horizontal cross section of the inclined change portion.
[FIG. 13C] FIG 13C, with respect to the front axle of the third embodiment and illustrating schematically another example of the horizontal cross section of the inclined change portion.
[Figure 14A] Figure 14A is a view showing a cross section taken along a line XIVA-XIVA of FIG. 13A ~ FIG 13C schematically.
FIG 14B] FIG 14B is a view showing a cross section taken along a line XIVB-XIVB in FIG. 13A ~ FIG 13C schematically.
FIG 14C] FIG 14C is a view showing a cross section taken along a line XIVC-XIVC in FIG. 13A ~ FIG 13C schematically.
[Figure 15A] Figure 15A is a perspective view of another example of the shape shown schematically waving.
[FIG. 15B] FIG 15B is a perspective view schematically showing another example of the corrugation.
[FIG. 15C] FIG 15C is a perspective view schematically showing another example of the corrugation.
[16] FIG 16 is a schematic diagram for explaining an example of a die forging process.
DESCRIPTION OF THE INVENTION
[0015]
　As a result of intensive studies, the present inventors have found that the particular structure, a front axle which can increase the rigidity newly found that obtained. The present invention is based on this new finding.
[0016]
　Hereinafter, embodiments of the present invention will be described. As will be described by way of example embodiments of the present invention in the following description, the present invention is not limited to the examples described below.
[0017]
　In this specification, when referring to the direction of the members constituting the front axle and which, unless otherwise stated, it refers to a direction in a state of arranging the front axle in the direction of use. For example, the term vertical direction of the front axle, unless otherwise stated, the vertical direction in a state of arranging the front axle in the direction of use (a direction parallel to the direction of gravity, a vertical Vt to be described later.) It means. The up-down direction (vertical direction) is the same direction as the vehicle height direction. Front axle is provided with kingpin mounting portion on the end portion. Vehicle height direction from the shape of the kingpin mounting portion can be identified. Kingpin is because mounted along the vehicle height direction. Similarly, the horizontal and longitudinal directions, means a direction in a state of arranging the front axle in the direction of use. That is, the horizontal direction correctly is the vehicle width direction. Vehicle width direction can be specified from the position of the kingpin mounting portion. Kingpin is because it is attached to both sides of the width of the vehicle. Incidentally, the front and rear of the front axle, respectively, means the same direction as and the rear front axle (direction Fw later) ahead of the vehicle is disposed. However, if the front axle is in the form of a symmetrical before and after the one direction and the front to the other direction as the rear. Front and rear, a vehicle length direction. Vehicle length direction can be specified from the vehicle height direction and vehicle width direction. In this specification, the term "cross section" is specifically described as long as it is determined from the context even without means a cross section perpendicular to the longitudinal direction of the front axle (described below "longitudinal direction LD").
[0018]
　(Front axle beam)
　front axle of the embodiment (front axle beam) includes a beam portion, and the king pin mounting portion in the longitudinal ends of the beam portion. Beam portion includes a first flange portion, a second flange portion opposite the first flange portion, a web portion connecting standing the first flange portion and the second flange portion. Web portion, in cross-section of the beam portion, a first inclined portion inclined in one direction relative to the vehicle height direction, in other cross-section of the beam portion, opposite to the first direction relative to the vehicle height direction comprising a second inclined portion inclined in direction. The second inclined portion and the first inclined portion is desirably alternately in the longitudinal direction. Incidentally, the cross section of the beam portion means a section perpendicular to the longitudinal direction of the beam portion.
[0019]
　In another aspect, the front axle of this embodiment includes a beam portion, and two kingpin mounting portion. Two kingpin mounting portions are provided respectively on both longitudinal ends of the beam portions, each corresponding. Hole for accommodating the kingpin provided on the kingpin mounting portion is vacant vehicle height direction. Beam portion, the web portion connecting the first flange portion located above, and a second flange portion which is disposed below the first flange portion, and a first flange portion and the second flange portion including the door. Hereinafter, the longitudinal direction of the beam portion, sometimes referred to as "longitudinal direction LD".
[0020]
　Web portion includes an inclined change portion including a plurality of first inclined portion and a plurality of second inclined portion. Each of the plurality of first inclined portion, in a cross section perpendicular to the longitudinal direction, is inclined in one direction with respect to the vertical direction (up-down direction, the vehicle height direction). Each of the plurality of second inclined portions, in a cross section perpendicular to the longitudinal direction, are inclined in the opposite direction to the one direction with respect to the vertical direction. A first inclined portion and the second inclined portions are arranged alternately along the longitudinal direction LD.
[0021]
　Conventional web portion is generally have a parallel plate shape in a vertical direction (straight shape). In this case, anisotropy occurs in the rigidity of the front axle. That is, the front axle is strong in bending of the vehicle height direction, the bending of the vehicle length direction weaker than the vehicle height direction. For this reason, we want to also improve rigidity against the vehicle length direction of bending. As a countermeasure, the web portion of the present embodiment, there is a first inclined portion and the second inclined portion inclined in opposite directions to each other with respect to the vehicle height direction. This anisotropy of the strength of the front axle is reduced. When a first inclined portion and the second inclined portion are arranged unevenly, anisotropic distribution of rigidity of a portion disposed biased is an anisotropic distribution of rigidity of the deployed position without bias Unlike, poor balance. Therefore, it is desirable that a first inclined portion and the second inclined portion are arranged alternately along the vehicle width direction (longitudinal direction LD). Further, it is desirable that a first inclined portion and the second inclined portions are adjacent. According to this configuration, as described later, since the bracing structure is formed by adjacent portions of the first inclined portion and the second inclined portion, it is possible to increase the rigidity of the front axle. In one aspect, the web portion includes an inclined change portion which changes its inclination relative to the vehicle height direction (vertical direction). Inclined changing unit, for example, a waviness section is changing as wavy surface. Incidentally, portions other than the inclined change portion of the web portion may have the same straight shape as conventional web portion described above.
[0022]
　A first inclined portion and the second inclined portion, are connected so as to be arranged alternately. However, a first inclined portion is formed between the second inclined portion, there may be a portion which is not inclined with respect to the vertical direction.
[0023]
　In the cross section perpendicular to the longitudinal direction LD, the inclined change portion may be linear, may not be linear, and may include a linear portion and a curved portion. Each first and second inclined portions may independently contain vertical parallel portions.
[0024]
　Sum of the number and the number of the second inclined portion of the first inclined portion may be 5 or more, may be 6 or more (3 or more wavelengths). There is no particular limitation on the upper limit of these numbers can be arbitrarily determined according to the length and properties sought in the tilt change unit. In one example, the number of the first inclined portion and the sum of the number of the second inclined portion may be 50 or less. The inclination changing unit may, with respect to the longitudinal direction of the center of the front axle, if it is symmetrical, one of the number one of the first and second ramps, one more than the other number.
[0025]
　Inclined changing part is formed on at least a portion of the web portion. Tilt changes part may be formed over the entire longitudinal direction of the web portion may be formed only on part of the length of the web portion. Tilt changes of one example, is formed on all or part of the region between the two spring mounting seat. Since this region is longer in the longitudinal direction, the weight reduction effect is large when applying the inclined change portion in this portion. That is, when considering the waves of a certain wavelength, it can increase the number of waves by forming an inclined change portion in this portion. The flange portion of the area for the change in shape is small, it is possible to repeatedly form the same undulating shape. Merit Therefore, by forming the inclined change portion in the region between the two spring mounting seat, when manufactured by a manufacturing method including a die forging process, and an advantage that the mold is punching easy, die design becomes easy there is an advantage of such. Tilt changes of another example, in addition to all or part of the region between the two spring mounting seat, two spring mounting seat area is not a region between (e.g., a spring mounting seat and the kingpin mounting portion and it may be formed in a region) between.
[0026]
　Regard the inclination angle of the inclined change portion with respect to the vertical direction, the maximum value of the absolute value of the angle is limited by the height of the protrusion amount and the web portion of the flange portion from the web portion. Inclination angle of the inclined change portion with respect to the vertical direction, for example, may be in the range of 5 ° ~ 45 °. The The angle (angle X), described in the first embodiment.
[0027]
　The main rigidity required for the front axle, the vertical direction (height direction, the vertical direction) stiffness against bending stiffness against bending in the longitudinal direction (longitudinal direction of the vehicle), and include stiffness against twisting. According to the front axle of the present embodiment, it is possible to improve these rigid.
[0028]
　In top of the first flange portion, the connection between the web portion and the first flange portion (hereinafter may be referred to as "first connecting portion") has a shape protruding in the longitudinal direction of the vehicle . In top of the second flange portion, the connection between the web portion and the second flange portion (hereinafter may be referred to as "second connecting portion") has a shape protruding in the longitudinal direction of the vehicle . One of the first connecting portion and the second connecting portion may have the shape protruding in the vehicle length direction, both the first connecting portion and second connecting portion, tension in the longitudinal direction of the vehicle it may have a shape that issue.
[0029]
　In another aspect, the inclined change portion, the first connection between the web portion and the first flange portion, and are selected from the second connection between the web portion and the second flange portion at least one connection part may have a wavy shape and wavy along the longitudinal direction LD. Examples of wavy shape, undulation consists of curved shape (e.g. corrugation of sinusoidal), and include undulation including linear partial shape (e.g. wavy shape of the rectangular wave-like undulating shape or triangular waveform) is .
[0030]
　Both of the first connection portion and the second connecting portion, when having a shape protruding in the longitudinal direction of the vehicle, in the middle of the cross section of the first flange portion and the second flange portion, a first inclined portion it is preferable that the second inclined portion is a linear shape.
[0031]
　In another aspect, the inclined change portion, both the first connecting portion and second connecting portion may have the above-mentioned undulating shape. In this case, the first connecting portion of the wavy shape of the phase, it is preferable that the second connecting portions of the wavy shape of the phase has become substantially opposite phase. Here, the "reverse phase substantially", a first connecting portion of the wavy shape of the phase, and the second connection portion of the wavy shape of the phase is approximately 180 ° along the longitudinal direction LD (e.g. 160 in the range of ° ~ 200 °, and typically means that the 180 °) misalignment.
[0032]
　Shape protruding in the vehicle length direction is preferably a shape with six or more points of the projecting portion.
[0033]
　In another aspect, the wavy shape may be a shape including a wave of more than three wavelengths. Waving shape by a shape including a wave of more than three wavelengths, it is possible to realize a higher stiffness.
[0034]
　The front axle of this embodiment, it is preferable that the second inclined portion and the first inclined portion adjacent.
[0035]
　In another aspect, the front axle of the present embodiment, the angle of the inclined change portion with respect to the vertical direction in the cross section perpendicular to the longitudinal direction LD (described later angle X) is, though continuously changes along the longitudinal direction LD it may be. Or the angle may be changed discontinuously along the longitudinal direction LD.
[0036]
　Inclined change portion in a cross section perpendicular to the longitudinal direction LD is, to rotate back and forth oscillation about the intermediate portion of the inclined change portion in the cross-section may vary along the longitudinal direction LD. Here, the middle portion of the inclined change portion is a portion located between the first connecting portion and second connecting portion, for example the central portion (center point and the vicinity thereof described in the first embodiment) is there. Alternatively, the inclined change portion in a cross section perpendicular to the longitudinal direction LD, like the pendulum of a fulcrum of the first connection or the second connection part may vary along the longitudinal direction LD. From the viewpoint of the front axle strength, the flange portion, the web portion, the seat portion (spring mount seat), and kingpin mounting portion is desirably integrally ones. Further, for the same reason, the front axle is preferably produced by forging.
[0037]
　The following description with reference to the accompanying drawings, embodiments of the present invention. The embodiments described below are exemplary, at least a portion of the configuration in the following embodiment, can be replaced with the above-described configuration. In the following description, it may be omitted from redundant explanation are denoted by the same reference numerals to like parts. The following figures are all schematic and may be different from the actual shape, further, in some cases are omitted unnecessary portions in the description.
[0038]
　(First Embodiment)
　In the first embodiment, an example of a front axle of the embodiment. A perspective view of the front axle 100 of the first embodiment, schematically shown in FIG.
[0039]
　Referring to FIG. 1, the front axle (front axle beam) 100 includes a beam portion 110, and two kingpin mounting portions 150 respectively provided at both ends in the longitudinal direction LD of the beam portion 110. Incidentally, in the figure, it may exhibit longitudinal direction LD and forward direction Fw of the beam portion 110. The kingpin mounting portion 150, through hole kingpin is attached is formed. Normally, the front axle 100 has a symmetrical shape, and have a generally arcuate shape as a whole.
[0040]
　Beam unit 110 includes a web portion 120, a first flange portion 131 and the second flange portion 132,. The first flange portion 131 is located above the second flange portion 132 is disposed below the first flange portion 131. Web portion 120, and connects the first flange portion 131 and a second flange portion 132. That is, the first flange portion 131 faces the second flange portion 132. Web portion 120 is standing on the second flange portion 132, connected to the first flange portion 131 and a second flange portion 132.
[0041]
　Each of the first flange portion 131 and the second flange portion 132, which protrudes in the longitudinal from the vehicle height direction of the upper and lower ends of the web portion 120 (longitudinal direction of the vehicle), generally extends in the front-rear substantially horizontally. However, the first flange portion 131 and the second flange portion 132, respectively, may not extend horizontally.
[0042]
　The upper surface of the beam part 110 (upper surface of the first flange portion 131) has two spring mounting seat 111 is formed. Spring is arranged in the spring mounting seat 111, a vehicle body (including the engine) is mounted on the spring.
[0043]
　Web portion 120 includes an inclined change portion 121. The inclination of the inclined change portion 121, the inclined change portion 121 is changed along the longitudinal direction LD as wavy. In the example shown in FIG. 1, the inclined change portion 121 is formed between the two spring mounting seat 111. However, the inclined change portion 121 (the same applies to the other embodiments) which may also be formed on other portions as needed.
[0044]
　A perspective view of a portion of the inclined change portion 121, shown schematically in FIG. For ease of understanding, in the perspective view of FIG. 2 shows the outline of the first flange portion 131 by a dotted line. Further, a front view when viewed front axle 100 from the front is schematically shown in FIG. In FIG. 3, showing a portion of the inclined change portion 121 by hatching.
[0045]
　2, the connection between the web portion 120 and the first flange portion 131 and the first connecting portion 120a, the second connecting the connection between the web portion 120 and the second flange portion 132 the part 120b. In one example described in the first embodiment, both the first connecting portion 120a and a second connecting portion 120b has a wavy shape and wavy along the longitudinal direction LD. That is, in the top of the first flange portion 131, the first connecting part 120a has a shape protruding in the longitudinal direction of the vehicle. In top of the second flange portion 132, the second connecting portion 120b has a shape protruding in the longitudinal direction of the vehicle.
[0046]
　Inclined changing unit 121 includes a plurality of first inclined portion 121a and a plurality of second inclined portions 121b. The first inclined portion 121a and a second inclined portion 121b, are arranged alternately along the longitudinal direction LD.
[0047]
　Part of the horizontal cross section of the inclined change portion 121 of the first connecting portion 120a, schematically shown in Figure 4A. At the midpoint in the vertical direction of the inclined change portion 121, a portion of the horizontal cross section of the inclined change portion 121, shown schematically in Figure 4B. Part of the horizontal cross section of the inclined change portion 121 of the second connecting part 120b, shown schematically in Figure 4C.
[0048]
　Line VA-VA in FIG. 4A ~ Figure 4C, the line VB-VB, and the line VC-VC cross section (cross section perpendicular to the longitudinal direction LD), respectively, FIG. 5A, schematically shown in FIGS. 5B and 5C,. The cross-section shown in FIG. 5A is a sectional view taken along the line first inclined portion 121a. The cross-section shown in FIG. 5C is a cross-section at the second inclined portion 121b. In the sectional view shown in FIG. 5A, 5B and 5C,, omitted hatching. Also in the following diagram displaying the cross-section perpendicular to the longitudinal direction LD, sometimes not hatched.
[0049]
　The position in the longitudinal direction LD on the horizontal axis, when the longitudinal axis a position in the front-rear direction, the inclined change portion 121 of the first connecting part 120a has a wavy shape as shown in Figure 4A. Similarly, the inclined change portion 121 of the second connecting portion 120b has a wavy shape as shown in FIG. 4C.
[0050]
　As shown in FIG. 5A, each of the plurality of first inclined portion 121a, in a cross section perpendicular to the longitudinal direction LD, it is inclined in one direction with respect to the vertical direction (vertical direction) Vt. On the other hand, as shown in FIG. 5C, each of the plurality of second inclined portions 121b, in a section perpendicular to the longitudinal direction LD, it is inclined in the direction opposite to the first direction with respect to the vertical direction Vt.
[0051]
　The first inclined portion 121a and a second inclined portion 121b are arranged alternately along the longitudinal direction LD. Ie their inclined portion forms a brace structure (truss structural elements). Figure superimposed a cross in cross section and 5C in FIG. 5A, schematically shown in FIG. As shown in FIG. 6, the first inclined portion 121a and a second inclined portion 121b, to form a brace structure. Therefore, the front axle 100 which includes an inclined change portion 121, it is possible to realize high rigidity.
[0052]
　Thickness of the inclined change portion 121 may be a substantially constant irrespective of the position may be different depending on the position.
[0053]
　Although FIG. 4A ~ Figure 4C, as part of the inclined change portion 121, corrugated shape in the connecting portions 120a and 120b showed a range including the waves of 2.5 wavelength. An example of the amplitude of the corrugation of the first inclined portion 121a (amplitude Am1), and an example of the amplitude of the corrugation of the second inclined portion 121b (amplitude Am2), shown in FIGS 4A. Their amplitudes may be different may be the same in the first connecting portion 120a and a second connecting portion 120b, also not changed may be changed by the position in the longitudinal direction LD it may be.
[0054]
　As shown in FIGS. 4A and 4C, inclined change portion 121 has a wavy shape. This wavy shape, the waving second moment than conventional straight shape is not a shape is improved rigidity increases, it said from the viewpoint of strength of materials.
[0055]
　The are waves of phases shown in phase and 4C of the wave shown in FIG. 4A, it shifted so that the first inclined portion 121a and a second inclined portion 121b are alternately arranged along the longitudinal direction LD. In the example shown in FIG. 4A ~ Figure 4C, the wave of the phase shown in FIG. 4C is the inverse of the wave of the phase shown in FIG. 4A, in particular are offset 180 °.
[0056]
　In the example shown, the inclined change portion 121 in FIG. 4B, no waving shape. That is, in the middle of the horizontal section of the first flange portion 131 and the second flange portion 132, and the first inclined portion 121a and a second inclined portion 121b is linear shape. However, that may have a corrugated shape is inclined change portion 121 at the midpoint in the vertical direction of the inclined change portion 121 (e.g., see FIG. 11B to be described later).
[0057]
　As shown in FIG. 5A, in a cross section perpendicular to the longitudinal direction LD, the front-side surface of the first inclined portion 121a is inclined to face obliquely upward direction Duf, the surface of the rear side, obliquely It is inclined so as to be directed downward. On the other hand, as shown in FIG. 5C, in a cross section perpendicular to the longitudinal direction LD, the front-side surface of the second inclined portion 121b is inclined to face obliquely downward direction Ddf, the surface of the rear side It is inclined to face obliquely upward.
[0058]
　Here, as shown in FIG. 5A ~ FIG 5C, in a cross section perpendicular to the longitudinal direction LD, the angle between the inclined change portion 121 and the vertical direction (vertical direction) Vt is the angle X. More specifically, the line connecting the point 120ac and the point 120Bc, the angle between the vertical direction Vt, an inclined change part 121 and the vertical Vt an angle X formed by. As shown in FIGS. 5A ~ FIG 5C, the point 120ac, in a cross section perpendicular to the longitudinal direction LD, of the first connecting portion 120a, located in the center in the longitudinal direction Hfb. A point 120bc, in a cross section perpendicular to the longitudinal direction LD, of the second connecting portion 120b, positioned in the center in the longitudinal direction Hfb.
[0059]
　Furthermore, when looking at the front of the direction Fw right hand (the state in FIG. 5A ~ FIG 5C), the angle of turn counterclockwise by a positive angle, the angle of turn in a clockwise direction and a negative angle. In that case, the angle X of the first inclined portion 121a shown in Figure 5A becomes positive. On the other hand, the angle X of the second inclined portion 121b shown in FIG. 5C becomes negative. Angle X is alternately changes the plus and minus along the longitudinal direction LD. In a preferred example, the angle X is varied continuously. An example of such a change in the angle X, shown in Figure 7. As shown in FIG. 7, the angle X becomes positive in the first inclined portion 121a, the angle X is negative in the second inclined portion 121b. Angle X is continuously changed with a change in position in the longitudinal direction LD. In this case, the first inclined portion 121a and a second inclined portion 121b is adjacent. Figure 7 shows a wave of 3.5 wavelength.
[0060]
　In Figure 7, the maximum value of the absolute value of the angle X showed an example is the same in all of the first inclined portion 121a and a second inclined portion 121b. However, the maximum value of the absolute value of the angle X may be different in their respective parts of the. The maximum value of the absolute value of the angle X is related to the amplitude of undulating shape.
[0061]
　FIG 5A ~ FIG 5C, showing the center point 121Ct. Center point 121ct, in a horizontal section through the midpoint of the vertical inclination changing portion 121 is a point located in the longitudinal direction of the center of the inclined change portion 121.
[0062]
　Longitudinal direction LD inclined change portion 121 in a cross section perpendicular to the referred to as "back-and-forth rotating vibration" is a reciprocal vibration including the rotation around the portion between the first connecting portion 120a and a second connecting portion 120b (hereinafter as if there is) to, it varies along the longitudinal direction LD. Incidentally, in the example shown in the figure shows an example of back-and-forth rotating vibration about the center point 121Ct, the center of the back-and-forth rotating vibration may be offset from the center point 121Ct.
[0063]
　Through slightly the point shifted forward direction Fw from the center point 121ct of Figure 5A, and a part of the cross section parallel to the vertical direction Vt and a longitudinal LD, schematically shown (hatched in FIG. 8 is omitted to). Cross-section shown in FIG. 8 corresponds to a cross section along line VIII-VIII in FIG. 4A ~ Figure 4C. As shown in FIG. 8, the first inclined portion 121a has a second flange portion 132 to form the arch portion of the bottom surface. The arch has a semi-dome-like shape when viewed from the rear. On the other hand, the second inclined portion 121b has a first flange portion 131 to form an arch portion of the bottom surface. The arch has a semi-dome-like shape when viewed from the front. As shown in FIG. 8, the front axle 100, the orientation is arranged a number different these arches shapes. In contrast, the web portion of the common front axle is flat and does not include an arch shape. Therefore, the front axle of the present embodiment is different from the general front axle, it is possible to realize high rigidity.
[0064]
　In the schematic diagram of FIG. 5A ~ FIG 5C is omitted displayed for the gradient of the flange portion. However, the flange portion of the front axle to be produced by a usual die forging is (also applies to other embodiments of) the slope having a (inclination with respect to the mold opening direction) for demolding. Such gradient, shown in FIG. Referring to FIG. 9, the surface of the first flange portion 131 is inclined with respect to the horizontal direction HD, there is draft Y. Similarly, the surface of the second flange portion 132 is inclined from the horizontal direction HD, there is draft Y. Incidentally, draft Y may be different depending on the position of the flange portion. In any case, a flange portion which is produced by a general manufacturing method comprising the common type forging step has a shape capable of stamping.
[0065]
　Further, the corners of the flange portion is a schematic view of FIG. 5A ~ 5C are unrounded. However, in general has a corner portion of the flange portion is rounded shape (R shape). Further, a corner portion of the boundary between the flange portion and web portion (corner portion Crn of Figure 5A) is generally (also applies to the other embodiments) having a rounded shape.
[0066]
　(Second Embodiment)
　In the first embodiment has been described an example having the shape both of the first connecting portion 120a and a second connecting portion 120b is waving. However, it may have only one of these connection portions is waved shape. An example of the tilt change portion 121 of such a front axle 100, shows a fragmentary perspective view in FIG. 10. Further, it shows a part of a horizontal cross-sectional view of FIG. 11A ~ FIG 11C.
[0067]
　Figure 11A shows a portion of a horizontal cross section of the inclined change portion 121 of the first connecting portion 120a is schematically shown. Figure 11B shows a portion of a horizontal cross section of the inclined change portion 121 at the midpoint in the vertical direction of the inclined change portion 121 schematically. Figure 11C shows a portion of a horizontal cross section of the inclined change portion 121 of the second connecting portion 120b schematically.
[0068]
　Line XIIA-XIIA in FIG. 11A ~ FIG 11C, the line XIIB-XIIB, and the line XIIC-XIIC cross section (cross section perpendicular to the longitudinal direction LD), respectively, Fig. 12A, schematically illustrated in FIGS. 12B and 12C,. Since portions other than the inclined change portion 121 is similar to front axle 100 described in the first embodiment, the redundant description will be omitted.
[0069]
　Inclined changing part 121 shown in FIGS. 10 to 12C, of ​​the two connections 120a and 120b, a shape only the second connecting portion 120b is waving. The first connecting portion 120a is straight. Referring to FIG. 11B, having a horizontal cross section is also wavy shape of the web portion 120 at an intermediate point between the first flange portion 131 and the second flange portion 132. However, its amplitude is about half the amplitude of the wavy shape of the second connection portion 120b.
[0070]
　Also in the front axle 100 of the second embodiment, the inclined change portion 121 includes a plurality of first inclined portion 121a and a plurality of second inclined portions 121b. The first inclined portion 121a and a second inclined portion 121b, are arranged alternately along the longitudinal direction LD. As shown in FIG. 12A, the first inclined portion 121a, in a cross section perpendicular to the longitudinal direction LD, it is inclined in one direction with respect to the vertical direction (vertical direction) Vt. On the other hand, as shown in FIG. 12C, the second inclined portion, in a cross section perpendicular to the longitudinal direction LD, it is inclined in the direction opposite to the first direction with respect to the vertical direction Vt. As a result, the inclination of the inclined change portion 121 varies along the longitudinal direction LD. Specifically, the inclination of the inclined change portion 121, a first connecting portion 120a like a pendulum to a fulcrum, varies along the longitudinal direction LD. Unlike the example shown in the figure, as in the pendulum (inverted pendulum) to pivot the second connecting portion 120b, the inclination of the inclined change portion 121 may vary along the longitudinal direction LD. In that case, the inclined change portion 121 has a shape obtained by inverting the top and bottom of the inclined change portion 121 of Fig. 10. Alternatively, Figure 10 is rotated 180 °, the second flange portion 132 of the first flange portion 131 and the second flange portion may be a first flange portion.
[0071]
　Also in the front axle 100 of the second embodiment, the angle X, as shown in FIG. 7, alternately changes the plus and minus along the longitudinal direction LD.
[0072]
　Also in the front axle 100 of the second embodiment, a first inclined portion 121a and the second inclined portions 121b constituting a brace structure. Further, the inclined change portion 121 can be a vertical arcuate shape that the first flange portion 131 and the bottom surface, and vertical arcuate shape that the second flange portion 132 and the bottom surface regarded as being arranged alternately . Moreover, can be regarded as the longitudinal arch shape in the longitudinal direction of the waving shape is continuous. Therefore, even the front axle 100 of the second embodiment, it is possible to realize high rigidity.
[0073]
　(Third Embodiment)
　In the above embodiment, the cross section of the inclined change portion 121 (the longitudinal direction LD in the cross section perpendicular) is, if a linear (i.e., when the inclination is constant in cross-section) has been described. However, the cross section of the inclined change portion 121 may not be straight. An example of the tilt change portion 121 of such a front axle 100, shows a cross-sectional view in a horizontal direction in FIGS. 13A ~ FIG 13C.
[0074]
　13A shows a portion of a horizontal cross section of the inclined change portion 121 of the first connecting portion 120a is schematically shown. Figure 13B shows a portion of a horizontal cross section of the inclined change portion 121 at the midpoint in the vertical direction of the inclined change portion 121 schematically. Figure 13C shows a portion of a horizontal cross section of the inclined change portion 121 of the second connecting portion 120b schematically. These cross-section, is similar to the cross section shown in FIGS. 4A ~ Figure 4C, without redundant description.
[0075]
　Line XIVA-XIVA of FIG. 13A ~ FIG 13C, the line XIVB-XIVB, and the line XIVC-XIVC cross section (cross section perpendicular to the longitudinal direction LD), respectively, Fig. 14A, schematically illustrated in FIGS. 14B and 14C,. Since portions other than the inclined change portion 121 is similar to front axle 100 described in the first embodiment, the redundant description will be omitted.
[0076]
　Inclined changing part 121 shown in FIGS. 13A ~ 14C are both two connections 120a and 120b has a wavy shape. Like the front axle of the embodiments described above, the inclined change portion 121, and a plurality of first inclined portion 121a and a plurality of second inclined portions 121b, they are arranged alternately along the longitudinal direction LD ing. That is, the inclination of the inclined change portion 121 varies along the longitudinal direction LD as undulating surface thereof.
[0077]
　As shown in FIGS. 14A and FIG. 14C, the cross section of the first and second inclined portions 121a and 121b of the front axle 100 of the third embodiment includes a curved portion rather than straight. In this case, the first inclined portion 121a, in a cross section perpendicular to the longitudinal direction LD, is inclined in one direction with respect to the vertical direction (vertical direction) Vt. On the other hand, the second inclined portions 121b, in the section perpendicular to the longitudinal direction LD, are inclined in the direction opposite to the first direction with respect to the vertical direction Vt.
[0078]
　Also in the front axle 100 of the third embodiment, a first inclined portion 121a and the second inclined portion 121b it can be regarded as constituting a brace structure. Further, the inclined change portion 121, an arch shape that the first flange portion 131 and the bottom surface (half dome), arcuate (semi-dome shape) which the second flange portion 132 to the bottom surface and are arranged alternately there. For semi-dome shape is effective in improving the weight and stiffness, even front axle 100 of the third embodiment, it is possible to realize high rigidity.
[0079]
　Note that in the example of the case has been described having the shape both of the first connecting portion 120a and a second connecting portion 120b is waving. However, it may have only one of the wavy shape. For example, the front axle 100 described in the second embodiment, the cross section of the inclined change portion 121 (cross section perpendicular to the longitudinal direction LD) may comprise a curved portion. Since the semi-dome shape even in such a case are formed, it is possible to realize the weight reduction and high rigidity.
[0080]
　Incidentally, wavy shape is not limited to the shape illustrated in the above embodiment. For example, wavy shape, as shown in FIG. 15A, may be shaped as connecting the semicircular. Or wavy shape, as shown in FIG. 15B, it may be a rectangular wave. Or wavy shape, as shown in FIG. 15C, or may be triangular. These wavy shape can be replaced by any of the wavy shape of the embodiment. Even when using these wavy shape, the structure described above (brace structure, arcuate, semi-dome shape) is achieved. Therefore, even when using these wavy shape, the above-mentioned effects can be obtained.
[0081]
　The results of the simulation conducted by the present inventors, wavy shape preferably includes a wave of more than three wavelengths. That is, a connection portion 120a and / or 120b, the shape protruding in the vehicle length direction is preferably a shape with six or more points of the projecting portion.
[0082]
　(An example of a manufacturing method of the front axle)
　is not particularly limited to the manufacturing method of the front axle of this embodiment can be prepared using known techniques. For example, the front axle of this embodiment may be manufactured by a manufacturing method comprising a hot forging process. An example of a method of manufacturing the front axle will be described below. Incidentally, only the method for producing a front axle of this embodiment is not, may be prepared by a method other than the method described below.
[0083]
　First, a billet as a material. Then, the billet is processed into a preform having a shape suitable for die forging (preforming step). The preforming step, and the step of squeezing the billet may include bending beating process. Then, the preform was die forging, forming a forged product having a shape of the front axle (die forging step). In this die forging process, the shape is imparted waving the web portion. These preliminary molding step and the mold forging step is carried out in hot. Thus forgings are obtained having the shape of the front axle. The resulting forged product may be subjected to various processes as needed. Examples of these processes, burr punching process, shaping step, bending-up process, the heat treatment step, the surface treatment process, drilling process, and the like coating process.
[0084]
　An example of a die forging step of the manufacturing process of the front axle of this embodiment will be described. The stamping direction SD of the press mold, the beam 110 after it has been die forging a cross section (including the inclined change portion 121) shown in FIG. 16. Beam portion 110 shown in FIG. 16 is a beam portion 110 of the front axle 100 described in the second embodiment.
[0085]
　When forming the general shape of the front axle by die forging typically perform forging to the front-rear direction of the front axle side is pressed against the mold. At this time, the portion to be inverse gradient during die cutting can not be molded by die forging. Therefore, the web portion is preferably free of shape which is inverse gradient when die forging. That is, the web portion is preferably free a portion to be a blind spot when viewing the web portion from the front and rear. Tilt changes 121 described in the first to third embodiment does not include a shape that a reverse gradient when die forging. Therefore, the inclined change portion 121 of the front axle 100 described in the first to third embodiments, if only reflect the corrugation in the mold design to mold, can be easily formed by using a general type forging step. That is, the front axle of this embodiment can be easily prepared by conventional manufacturing methods.
Industrial Applicability
[0086]
　The present invention can be used in the front axle beam.
DESCRIPTION OF SYMBOLS
[0087]
　100: front axle (front axle
　beam) 110: beam portion
　120: web portion
　120a: first connecting portion
　120b: second connecting part
　121: inclined change portion
　121a: first inclined portion
　121b: second inclined portion
　131: first flange portion
　132: second flange portion
　150: kingpin mounting portion
　LD: longitudinal
　Fw: forward direction

The scope of the claims
[Requested item 1]A first flange portion, a second flange portion opposite to the first flange portion, a beam portion and a web portion connecting stand with the first flange portion and the second flange portion the a kingpin mounting portion in the longitudinal ends of the beam portion, a front axle beam comprising,
　said web portion,
　in cross-section of the beam portion, a first inclined in one direction relative to the vehicle height direction an inclined portion,
　in other cross-section of the beam portion, and a second inclined portion inclined in a direction opposite said one direction relative to the vehicle height direction, a front axle beam.
[Requested item 2]
　Wherein the first inclined portion and the second inclined portion, said longitudinal located alternately in the front axle beam according to claim 1.
[Requested item 3]
　In top of the first flange portion, the first connecting portion between said web portion said first flange portion has a shape protruding in the longitudinal direction of the vehicle, according to claim 1 or claim 2 of the front axle beam.
[Requested item 4]
　In top of the second flange portion, a second connecting portion between said web portion and the second flange portion has a shape projecting in the vehicle length direction, front axle according to claim 3 beam.
[Requested item 5]
　Wherein the first flange portion and the middle of the cross section of said second flange portion, wherein the first inclined portion and the second inclined portion is a linear shape, the front axle beam according to claim 4.
[Requested item 6]
　Shape protruding to the vehicle length direction, a shape with six or more points of the projecting portion, the front axle beam according to any one of claims 3-5.
[Requested item 7]
　Wherein the second inclined portion and the first inclined portion adjacent the front axle beam according to any one of claims 1 to 6.