Bracket mounting structure

Abstract

To prevent an axle case from being damaged in a bracket mounting structure.SOLUTION: A bracket mounting structure includes an axle case 1 extending in a vehicle width direction of a vehicle and having a central region 11 and a mounting region 12, and a bracket connecting the axle case to a component of the vehicle and having an upper bracket member provided on an upper surface of the axle case and receiving a load of the component of the vehicle from above and a lower bracket member 22 provided on a lower surface of the axle case, wherein an upper surface 222 of the lower bracket member has a first protruding portion 223 protruding in the vehicle width direction from a central portion of the upper surface 222. The first protrusion includes at least a first side 224 and a second side 227 which extend along the contour of the first protrusion and approach each other as they go away from the center of the upper surface in the vehicle width direction, and the lower bracket member is welded to the axle case at the first side and the second side.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a bracket mounting structure. [Background technology]

[0002] Conventionally, vehicles are provided with a bracket mounting structure. Patent Document 1 discloses a structure in which an upper member and a lower member are provided on the upper and lower surfaces of the middle part of an axle case, respectively, and the upper and lower members of a spring seat to which the vehicle weight is applied are welded to the axle case. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-30332 Summary of the Invention [Problem to be solved by the invention]

[0004] When the edge of the lower member of the spring seat extends in the fore-and-aft direction of the vehicle and is welded to the axle case, high stress is generated locally in the axle case, causing the axle case to break.

[0005] The present invention has been made in consideration of these points, and has an object to provide a bracket mounting structure that makes it difficult for the axle case to be damaged. [Means for solving the problem]

[0006] In a first aspect of the present invention, there is provided a bracket mounting structure comprising: an axle case extending in the vehicle width direction, the axle case having a central region and an attachment region that has a length in the vehicle height direction shorter than the length of the central region and extends from an end of the central region in the vehicle width direction; and a bracket that connects the axle case to a component of the vehicle, the bracket having an upper bracket member that is provided on the top surface of the axle case and receives the load of the component from above, and a lower bracket member that is provided on the bottom surface of the axle case, wherein the top surface of the lower bracket member has a first protrusion that protrudes in the vehicle width direction from the center of the top surface, the first protrusion having at least a first side and a second side that extend along the contour of the first protrusion, and that approach each other as they move away from the center of the top surface in the vehicle width direction, and the lower bracket member is welded to the axle case at the first side and the second side.

[0007] In addition, the upper surface of the lower bracket member may further have a second protrusion provided on the opposite side of the first protrusion in the vehicle width direction, and the second protrusion may include at least a third side and a fourth side extending along the contour of the second protrusion, the third side and the fourth side approaching each other as they move away from the center of the upper surface in the vehicle width direction, and the lower bracket member may be welded to the axle case at the third side and the fourth side.

[0008] The first side and the second side may be provided at positions where the section modulus of the axle case at one end of each side is different from the section modulus of the axle case at the other end.

[0009] The first side and the second side may be provided at positions such that the height of the axle case at one end of each side is different from the height of the axle case at the other end.

[0010] In addition, the upper surface of the lower bracket member may be formed in a polygonal shape including the first side, the second side, the third side, and the fourth side, and the entire circumference of the upper surface may be welded to the axle case. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide an effect that the axle case is less likely to be damaged in the bracket mounting structure. [Brief explanation of the drawings]

[0012] [Figure 1] 1 shows the structure of a bracket mounting structure according to the present embodiment. [Figure 2] FIG. 2 is an enlarged view of the vicinity of the bracket in the bracket mounting structure. [Figure 3] FIG. 2 is a cross-sectional view taken along line XX in FIG. [Figure 4] 1 shows the structure of the lower bracket member. [Figure 5] 10 shows the structure of the upper surface of the lower bracket member. [Figure 6] 10 shows the structure of a conventional lower bracket member as a comparative example. [Figure 7] 1 shows the results of a simulation comparing a conventional structure with a structure according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] [Structure of bracket mounting structure S] Fig. 1 is a diagram showing the structure of a bracket mounting structure S according to this embodiment. Fig. 2 is an enlarged view of the vicinity of a bracket 2 in the bracket mounting structure S. Fig. 3 is a cross-sectional view taken along line XX in Fig. 1.

[0014] The bracket mounting structure S has an axle case 1 and a bracket 2. The axle case 1 is a component that houses an axle shaft, a differential gear mechanism, and the like, not shown.

[0015] The axle case 1 extends in the width direction of the vehicle and has a central region 11 and a mounting region 12. The central region 11 has a region that bulges out vertically in the height direction of the vehicle to accommodate a differential gear mechanism.

[0016] The attachment region 12 is a region that extends from the end portions in the vehicle width direction of the central region 11. The attachment region 12 extends from each of the two ends in the vehicle width direction of the central region 11. The attachment region 12 has a region with a rectangular cross section.

[0017] The mounting region 12 has a length in the vehicle height direction that is shorter than the length of the central region 11. The length in the vehicle height direction near the boundary between the central region 11 and the mounting region 12 of the axle case 1 gradually decreases from the center of the central region 11 toward the outside in the vehicle width direction.

[0018] The height of the upper surface of the axle case 1 near the boundary between the central region 11 and the mounting region 12 gradually decreases from the center of the central region 11 toward the outside in the vehicle width direction. Also, the height of the lower surface of the axle case 1 near the boundary between the central region 11 and the mounting region 12 gradually increases from the center of the central region 11 toward the outside in the vehicle width direction.

[0019] Since the central region 11 has regions that bulge out upward and downward, the section modulus of the central region 11 is greater than the section modulus of the mounting region 12. As shown in Figure 2, in the axle case 1, the section modulus changes significantly near the boundary between the central region 11 and the mounting region 12 in the vehicle width direction of the axle case 1.

[0020] Because the axle case 1 has a cavity, the section modulus of the front and rear ends is larger than that of the center portion in the vehicle longitudinal direction of the axle case 1. As shown in Figure 3, the section modulus of the axle case 1 changes significantly near the boundary between the center portion and the front end and near the boundary between the center portion and the rear end in the vehicle longitudinal direction of the axle case 1.

[0021] The bracket 2 is a component that connects the axle case 1 to a vehicle component. The vehicle component is, for example, a chassis frame (not shown). Specifically, the bracket 2 is connected to a suspension (not shown), and connects the axle case 1 to the chassis frame via the suspension.

[0022] The bracket 2 has an upper bracket member 21 and a lower bracket member 22. The upper bracket member 21 is attached to the top surface of the axle case 1. The upper bracket member 21 receives the load W of the vehicle components from above. The lower bracket member 22 is attached to the bottom surface of the axle case 1. The suspension and chassis frame are placed on the axle case 1 via the bracket 2, so the weight of the vehicle and cargo is applied to the axle case 1.

[0023] A road reaction load R is applied upward via the wheel to the end tube provided at the end of the mounting region 12 opposite the central region 11 in the vehicle width direction. Therefore, when the loads W and R cause downward convex bending deformation in the axle case 1, tensile stress is generated on the underside of the axle case 1.

[0024] [Structure of the lower bracket member 22] Fig. 4 is a diagram showing the structure of the lower bracket member 22. Fig. 4 is a diagram showing the vicinity of the lower bracket member 22 of the bracket mounting structure S shown in Fig. 1 as viewed from below. Fig. 5 is a diagram showing the structure of the upper surface 222 of the lower bracket member 22.

[0025] The lower surface 221 of the lower bracket member 22 is formed in a polygonal shape. The lower bracket member 22 is, for example, hexagonal. As shown in FIG. 2, the height of the upper surface 222 of the lower bracket member 22 varies along the lower surface of the axle case 1 so that the inner end is positioned lower than the outer end in the vehicle width direction. As shown in FIG. 5, the upper surface 222 of the lower bracket member 22 is formed in a polygonal shape including a first side 224, a second side 227, a third side 231, and a fourth side 234. The upper surface 222 of the lower bracket member 22 is hexagonal. In FIGS. 1 and 2, the lower bracket member 22 is depicted schematically, and the horizontal area of ​​the member is constant; however, in this embodiment, the area of ​​the upper surface 222 is smaller than the area of ​​the lower surface 221.

[0026] An upper surface 222 of the lower bracket member 22 is welded to the lower surface of the axle case 1. As shown in Fig. 5, the upper surface 222 of the lower bracket member 22 has a first protrusion 223 and a second protrusion 230. The first protrusion 223 is a portion that protrudes from the center of the upper surface 222 of the lower bracket member 22 in the vehicle width direction. Specifically, the first protrusion 223 protrudes inward from the center of the upper surface 222 of the lower bracket member 22 in the vehicle width direction.

[0027] The first protruding portion 223 is formed in a horizontal V-shape and includes a first side 224 and a second side 227. The first side 224 and the second side 227 are sides that extend along the outline of the first protruding portion 223. The first side 224 and the second side 227 are sides that approach each other as they move away from the center of the upper surface 222 of the lower bracket member 22 in the vehicle width direction. Specifically, the first side 224 and the second side 227 are sides that approach each other as they move away from the center of the upper surface 222 of the lower bracket member 22 toward the inside in the vehicle width direction.

[0028] The first side 224 is inclined with respect to the front-rear direction of the vehicle (the up-down direction in FIG. 5 ) so that one end 225 of the first side 224 is located more inward in the vehicle width direction than the other end 226 of the first side 224. The second side 227 is inclined with respect to the front-rear direction of the vehicle so that one end 228 of the second side 227 is located more inward in the vehicle width direction than the other end 229 of the second side 227. One end 225 of the first side 224 and one end 228 of the second side 227 are connected. The first side 224 and the second side 227 are symmetrical with respect to the front-rear direction of the vehicle, centered on the connection point between one end 225 of the first side 224 and one end 228 of the second side 227.

[0029] In this embodiment, the entire periphery of the upper surface 222 of the lower bracket member 22 is welded. That is, the lower bracket member 22 is welded to the axle case 1 at the first side 224 and the second side 227.

[0030] 6 is a diagram showing the structure of a conventional lower bracket member 3 as a comparative example. The conventional lower bracket member 3 differs from lower bracket member 22 in that it does not have a first protrusion and that the side of lower bracket member 3 extending in the front-to-rear direction of the vehicle is welded to the axle case 1.

[0031] In a structure in which the edges extending in the longitudinal direction of the vehicle are welded in this way, stress concentration occurs, resulting in high stress in the axle case 1. One example of the causes of this stress concentration is that 1. large cross-sectional change in the axle case 1 in the width direction of the vehicle, 2. large cross-sectional change in the axle case 1 in the longitudinal direction of the vehicle, and 3. tension (underside) - 1. to 3. occur at the same location on the weld.

[0032] In contrast, in the bracket mounting structure S, as described above, the upper surface 222 of the lower bracket member 22 has a first protrusion 223 that includes at least the first side 224 and the second side 227, and the lower bracket member 22 is welded to the axle case 1 at the first side 224 and the second side 227. As a result, of the aforementioned causes of high stress generation, 1 and 2 occur at different points in the weld, which distributes the stress and makes it less likely for high stress to occur in the axle case 1. Also, by ensuring that the welded portion of the lower bracket member 22 is not positioned in a position where the axle case 1 has a large change in section modulus in the vehicle width direction and the longitudinal direction of the vehicle overlap, it is possible to make it less likely for high stress to occur in the welded portion.

[0033] The mechanism for alleviating stress concentration has been explained above using the first protruding portion 223 as an example, but in this embodiment, a second protruding portion 230 having a function similar to that of the first protruding portion 223 is also provided. The second protruding portion 230 is provided on the opposite side of the first protruding portion 223 in the vehicle width direction. Specifically, the second protruding portion 230 is a portion that protrudes outward in the vehicle width direction from the center of the upper surface 222 of the lower bracket member 22.

[0034] The second protruding portion 230 includes at least a third side 231 and a fourth side 234. The third side 231 and the fourth side 234 are sides that extend along the outline of the second protruding portion 230. The third side 231 and the fourth side 234 are sides that approach each other as they move away from the center of the upper surface 222 of the lower bracket member 22 in the vehicle width direction.

[0035] The third side 231 is inclined with respect to the front-rear direction of the vehicle such that one end 232 of the third side 231 is located outward in the vehicle width direction of the vehicle than the other end 233 of the third side 231. The fourth side 234 is inclined with respect to the front-rear direction of the vehicle such that one end 235 of the fourth side 234 is located outward in the vehicle width direction of the vehicle than the other end 236 of the fourth side 234. One end 232 of the third side 231 and one end 235 of the fourth side 234 are connected. The third side 231 and the fourth side 234 are symmetrical with respect to the front-rear direction of the vehicle, with respect to the connection point between the one end 232 of the third side 231 and the one end 235 of the fourth side 234. Furthermore, the third side 231 and the fourth side 234, and the first side 224 and the second side 227 are symmetrical with respect to the center of the upper surface 222 of the lower bracket member 22 in the vehicle width direction of the vehicle.

[0036] The lower bracket member 22 is welded to the axle case 1 at the third side 231 and the fourth side 234. As a result, in the bracket mounting structure S, stress generated when welding the axle case 1 is dispersed, making it less likely that high stress will occur in the axle case 1.

[0037] The first side 224 and the second side 227 are located in positions where the section modulus of the axle case 1 at one end 225, 228 of each side is different from the section modulus of the axle case 1 at the other end 226, 229. Specifically, for example, one end 225, 228 of each of the first side 224 and the second side 227 is located in the central region 11, and the other end 226, 229 is located in the mounting region 12. As a result, in the bracket mounting structure S, stress generated when welding the axle case 1 is dispersed, making it less likely that high stress will occur in the axle case 1.

[0038] The first side 224 and the second side 227 are provided such that the height of the axle case 1 at one end 225, 228 of each side is different from the height of the axle case 1 at the other end 226, 229. Specifically, for example, one end 225, 228 of each of the first side 224 and the second side 227 is located in the central region 11, and the other end 226, 229 is located in the mounting region 12. As a result, in the bracket mounting structure S, stress is dispersed, making it less likely that high stress will occur in the axle case 1.

[0039] The entire periphery of the upper surface 222 of the lower bracket member 22 is welded to the axle case 1. Therefore, in the bracket mounting structure S, the lower bracket member 22 can be firmly fixed to the axle case 1.

[0040] Although the above description has been given of welding the lower bracket member 22 to the axle case 1, the upper bracket member 21 may also be welded to the axle case 1 in the same manner as the lower bracket member 22 described above.

[0041] Figure 7 shows the results of a simulation comparing a conventional structure with a structure according to the present invention. Figure 7(a) shows the results of a simulation in which a conventional lower bracket member 3 is fixed to the axle case 1. Figure 7(b) shows the results of a simulation in which a lower bracket member 22 according to the present invention is fixed to the axle case 1.

[0042] In this simulation, the degree of stress concentration was verified when a lower bracket member 3 of a conventional structure was fixed to an axle case 1 of the same shape, and when a lower bracket member 22 according to the present invention was fixed to the axle case 1. The numerical values ​​shown are merely values ​​corresponding to the specific shapes and dimensions of each part used in the simulation, and the numerical values ​​themselves do not limit the present invention.

[0043] As shown in Figure 7(a), in the conventional structure, the portion of the lower bracket member 3 that runs along the straight edge in the fore-and-aft direction of the vehicle is welded, causing high stress at corner A. In contrast, in the configuration shown in Figure 7(b), although stress is concentrated at corner A and tip B, it was confirmed that the stress value is mitigated compared to the conventional structure.

[0044] [Effects of the bracket mounting structure S according to this embodiment] In the bracket mounting structure S of this embodiment, the upper surface 222 of the lower bracket member 22 has a first protrusion 223 that protrudes from the center of the upper surface 222 in the vehicle width direction, and the first protrusion 223 includes at least a first edge 224 and a second edge 227 that extend along the contour of the first protrusion 223, and which approach each other as they move away from the center of the upper surface 222 of the lower bracket member 22 in the vehicle width direction, and the lower bracket member 22 is welded to the axle case 1 at the first edge 224 and the second edge 227.

[0045] As a result, in the bracket mounting structure S, the causes of high stress are prevented from concentrating in the same location, and the stress generated in the axle case 1 can be dispersed. Therefore, high stress is less likely to be generated in the axle case 1, making the axle case 1 less likely to be damaged.

[0046] The present invention has been described above using embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments, and various modifications and changes are possible within the scope of the gist of the present invention. For example, all or part of the device can be configured by functionally or physically distributing or integrating any unit. Furthermore, new embodiments resulting from any combination of multiple embodiments are also included in the embodiments of the present invention. The effects of the new embodiments resulting from the combination also have the effects of the original embodiments. [Explanation of symbols]

[0047] S···Bracket mounting structure 1. Axle case 11...Central area 12. Mounting area 2 bracket 21 Upper bracket member 22 Lower bracket member 221...Bottom surface 222...Top surface 223...1st protrusion 224...First side 225...one end 226...other end 227...Second side 228...one end 229...other end 230...Second protrusion 231... Third side 232...one end 233...other end 234... Side 4 235...one end 236...other end 3. Conventional lower bracket member

Claims

1. an axle case extending in a vehicle width direction of a vehicle, the axle case having a central region and an attachment region having a length in a height direction of the vehicle shorter than a length of the central region and extending from an end of the central region in the vehicle width direction; a bracket for connecting the axle case to a component of the vehicle, the bracket having an upper bracket member provided on an upper surface of the axle case and receiving a load from above of the component, and a lower bracket member provided on a lower surface of the axle case; Equipped with an upper surface of the lower bracket member has a first protruding portion protruding in the vehicle width direction from a center portion of the upper surface; the first protruding portion includes at least a first side and a second side extending along a contour of the first protruding portion, the first side and the second side approaching each other as the first side and the second side move away from the center of the upper surface in the vehicle width direction, A bracket mounting structure in which the lower bracket member is welded to the axle case at the first side and the second side.

2. an upper surface of the lower bracket member further includes a second protruding portion provided on an opposite side to the first protruding portion in the vehicle width direction; the second protruding portion includes at least a third side and a fourth side extending along a contour of the second protruding portion, the third side and the fourth side approaching each other as the second protruding portion moves away from the center of the upper surface in the vehicle width direction, The lower bracket member is welded to the axle case at the third side and the fourth side. The bracket mounting structure according to claim 1 .

3. The first side and the second side are provided at positions where the section modulus of the axle case at one end of each side is different from the section modulus of the axle case at the other end of each side. The bracket mounting structure according to claim 1 or 2.

4. The first side and the second side are provided at positions where the height of the axle case at one end of each side is different from the height of the axle case at the other end of each side. The bracket mounting structure according to claim 1 or 2.

5. an upper surface of the lower bracket member is formed in a polygonal shape including the first side, the second side, the third side, and the fourth side, and the entire periphery of the upper surface is welded to the axle case; The bracket mounting structure according to claim 2 .

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