Vehicle structure

Abstract

This vehicle structure includes a cross member extending in a vehicle width direction and constituting a frame of a vehicle, a suspension cross member disposed toward the rear of the vehicle relative to the cross member, and a connecting member connecting the cross member and the suspension cross member, wherein the connecting member is joined to at least one of the cross member and the suspension cross member via a flange portion.

Description

Vehicle Structure

[0001] The present invention relates to a vehicle structure.

[0002] Patent Document 1 discloses a structure comprising: a pair of left and right side members extending in the front-rear direction of a vehicle body; a suspension member supported by the pair of left and right side members for suspending front wheels; a connecting body extending in the vehicle width direction along the front end portion of the suspension member and fixed to each side member side; and a bracket plate bridged between the connecting body and the suspension member. By adopting such a configuration, it is intended to suppress the occurrence of the disadvantage that the vibration level at the front end portion of the suspension member becomes remarkably large due to a resonance phenomenon in a process where the frequency of vibration of the suspension member increases due to an impact force during vehicle traveling, thereby preventing abnormal noise with a large sound pressure level from being generated in the vehicle compartment.

[0003] Japanese Unexamined Patent Publication No. 2010-95053

[0004] Incidentally, in a vehicle such as an automobile, a front suspension cross member for suspending front wheels is sometimes provided on the vehicle rear side with respect to a cross member at the forefront of the vehicle that constitutes a frame. When adopting such a structure, the inventors of the present application have conceived of arranging a brace bar extending in the front-rear direction so as to bridge between the front cross member and the front suspension cross member, in order to prevent the space between the front cross member and the rear front suspension cross member from being crushed during a frontal collision. However, a steering gear box is supported by the front suspension cross member. For this reason, a load directed in the vehicle width direction from the steering gear box is applied to the front suspension cross member, relative stress in the vehicle width direction is generated between the front suspension cross member and the cross member, and there is a possibility that a stress concentration portion may occur in the brace bar connecting between these members.

[0005] Therefore, an object of the present invention is to provide a vehicle structure capable of suppressing stress concentration on a connecting member that connects a cross member and a suspension cross member while preventing the space between the cross member and the suspension cross member from being crushed during a frontal collision.

[0006] The present invention comprises the following configuration: a vehicle structure having a cross member extending in the vehicle width direction and constituting the frame of the vehicle; a suspension cross member positioned at the rear of the vehicle relative to the cross member; and a connecting member connecting the cross member and the suspension cross member, wherein the connecting member is joined to at least one of the cross member and the suspension cross member via a flange portion.

[0007] According to the present invention, it is possible to provide a vehicle structure that prevents the space between the cross member and the suspension cross member from collapsing during a frontal collision, while suppressing stress concentration on the connecting member that connects the cross member and the suspension cross member.

[0008] Figure 1 is a plan view of the frame at the front of the vehicle illustrating the vehicle structure according to this embodiment. Figure 2 is a perspective view of the brace bar seen from above. Figure 3 is a perspective view of the brace bar seen from below. Figure 4 is a plan view of the brace bar. Figure 5 is a rear view of the brace bar. Figure 6 is a view taken along arrow A in Figure 2. Figure 7 is a view taken along arrow B in Figure 2. Figure 8 is a side view of the brace bar.

[0009] Embodiments of the present invention will be described in detail below with reference to the drawings. In Figure 1 below, the foreground of the paper indicates the top of the vehicle, the symbol FR (left side in Figure 1) indicates the front of the vehicle, and the symbol LH (bottom of Figure 1) indicates the left side in the vehicle width direction (left side in the direction of travel). The background of the paper is the bottom of the vehicle, the opposite direction of symbol FR (right side in Figure 1) is the rear of the vehicle, and the opposite direction of symbol LH (top of Figure 1) is the right side in the vehicle width direction (right side in the direction of travel). Hereinafter, these directions may simply be referred to as top, bottom, front, rear, left side, and right side.

[0010] Figure 1 is a plan view of the frame 11 at the front of the vehicle illustrating the vehicle structure according to this embodiment. Figure 2 is a perspective view of the brace bar 21L seen from above. Figure 3 is a perspective view of the brace bar 21L seen from below. Figure 4 is a plan view of the brace bar 21L. Figure 5 is a rear view of the brace bar 21L. Figure 6 is a view taken along arrow A in Figure 2. Figure 7 is a view taken along arrow B in Figure 2. Figure 8 is a side view of the brace bar 21L.

[0011] As shown in Figure 1, the vehicle structure according to this embodiment is mainly applied to the front structural part of a vehicle 100 such as an automobile. The type of automobile to which the vehicle structure is applied is not limited and may include an internal combustion engine vehicle (ICEV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), or an electric vehicle (BEV).

[0012] The vehicle 100 is equipped with a frame 11 that constitutes the chassis. The frame 11 has a pair of left and right side members 13, 13. The pair of side members 13, 13 are spaced apart in the vehicle width direction and each extends in the vehicle longitudinal direction. The frame 11 also has a plurality of cross members 15. Note that only the cross member 15 located at the front of the vehicle is shown in Figure 1. These plurality of cross members 15 are spaced apart in the vehicle longitudinal direction. Each cross member 15 extends in the vehicle width direction and is joined to the pair of left and right side members 13, 13.

[0013] Vehicle 100 is equipped with a front suspension member 17 that suspends the front wheels, located on the rear side of the frame 11 relative to the cross member 15 at the very front of the vehicle. The front suspension member 17 is supported at the bottom of the frame 11. The front suspension member 17 has a pair of suspension cross members (hereinafter referred to as suspension cross members) 19, 19 that extend in the vehicle width direction and are spaced apart in the vehicle longitudinal direction. Note that only the suspension cross member 19 on the front side of the vehicle is shown in Figure 1. The front suspension cross member 19 is spaced apart from each other in the vehicle longitudinal direction relative to the cross member 15 at the very front of the frame 11. This suspension cross member 19 has a pair of fixed parts 19a, 19a on the rear side of the vehicle that are spaced apart from each other in the vehicle width direction, and a steering gearbox (not shown) provided for steering the front wheels is fixed to this pair of fixed parts 19a, 19a.

[0014] The vehicle 100 according to this embodiment is equipped with a pair of brace bars 21L and 21R as connecting members between the front cross member 15 and the rear suspension cross member 19. These brace bars 21L and 21R are formed in a symmetrical shape and are spaced apart from each other in the vehicle width direction. The cross member 15 and the suspension cross member 19 are connected in the front-rear direction by the pair of brace bars 21L and 21R. These brace bars 21L and 21R prevent the space between the cross member 15 and the suspension cross member 19 from being crushed in the event of a frontal collision.

[0015] Next, the pair of brace bars 21L and 21R will be described in detail. Since the pair of brace bars 21L and 21R are symmetrical, the brace bar 21L, which is located on the left side of the vehicle 100, will be described, and the description of the brace bar 21R, which is located on the right side of the vehicle 100, will be omitted.

[0016] As shown in Figures 1 to 8, the brace bar 21L has a main body 23, a front connecting portion (first connecting portion) 25, and a rear connecting portion (second connecting portion) 27. These main body 23, front connecting portion 25, and rear connecting portion 27 are each formed by press-forming a metal plate such as a steel plate. The front connecting portion 25 is provided on the side of the main body 23 that connects to the cross member 15 (front side), and the rear connecting portion 27 is provided on the side of the main body 23 that connects to the suspension cross member 19 (rear side). The front connecting portion 25 and the rear connecting portion 27 are each fixed to the main body 23. The front connecting portion 25 is attached to the cross member 15, and the rear connecting portion 27 is attached to the suspension cross member 19.

[0017] The main body portion 23 has a top plate portion 31 that is substantially vertical in the vertical direction, and a pair of left and right side plate portions 33, 33, with the pair of side plate portions 33, 33 extending downward from both side edges of the top plate portion 31 in the vehicle width direction. As a result, the main body portion 23 is formed in a U-shape with the bottom side open when viewed in cross-section in the vehicle width direction. The side plate portion 33 on the rear connection portion 27 side has an overhang portion 34 that gradually extends downward toward the rear connection portion 27. The main body portion 23 also has a mounting piece 35 extending in the vehicle width direction at the end of the side plate portion 33 on the rear connection portion 27 side. The mounting piece 35 of the main body portion 23 extends further outward in the vehicle width direction than the joining piece 47 of the front connection portion 25.

[0018] The main body portion 23 has a reinforcing plate 37 inside. As shown in Figure 8, the reinforcing plate 37 is positioned approximately in the center in the vertical direction between the pair of side plate portions 33, 33 of the main body portion 23, and extends along the longitudinal direction (front-to-back direction) of the main body portion 23. On the rear connection portion 27 side, the reinforcing plate 37 is bent to match the shape of the protruding portion 34 of the side plate portion 33 that protrudes downward, and is inclined downward. The reinforcing plate 37 is assembled by welding both edges of it to the inner surfaces of the pair of side plate portions 33, 33 so as to close the lower surface of the main body portion 23. Thus, by assembling the reinforcing plate 37, the main body portion 23 has a closed cross-section surrounded by the top plate portion 31, the pair of side plate portions 33, 33 and the reinforcing plate 37. Furthermore, since the reinforcing plate 37 is positioned approximately in the center of the main body 23 in the vertical direction, the main body 23 can be reinforced in a balanced manner along its longitudinal direction.

[0019] Furthermore, the end of the reinforcing plate 37 on the front connection portion 25 side is bent downward to avoid the bolts passed through the bolt insertion holes 33a and 43a described later, then folded back upward and extends further upward (see Figure 8). As a result, the reinforcing plate 37 has a vertical wall portion 39 extending in the vertical direction at the end on the front connection portion 25 side. By providing the vertical wall portion 39 at the front end of the reinforcing plate 37 in this way, the strength of the reinforcing plate 37 can be increased, and the rigidity of the main body portion 23 can be further increased.

[0020] The front connecting portion 25 has a top plate portion 41 that is substantially vertical in the vertical direction, and a pair of side plate portions 43, 43, with the pair of side plate portions 43, 43 extending downward from both side edges of the top plate portion 41 in the vehicle width direction. As a result, the front connecting portion 25 is formed in a U-shape with the lower side open in a cross view in the vehicle width direction. The front connecting portion 25 has flange portions 45 extending toward the cross member 15 side (front side) at the front edge of each side plate portion 43. The flange portions 45 also have a connecting piece 47 that protrudes toward the vehicle width direction at the end (front end) on the cross member 15 side.

[0021] The front connecting portion 25 is formed in a U-shape by an upper plate portion 41 and a pair of side plate portions 43, 43, having a vehicle width dimension slightly larger than that of the main body portion 23. The front connecting portion 25 is placed over the main body portion 23 from above so as to cover it. The pair of side plate portions 33, 33 of the main body portion 23 and the pair of side plate portions 43, 43 of the front connecting portion 25 each have bolt insertion holes 33a, 43a that communicate with each other when they are superimposed. For example, the front connecting portion 25 is attached to the main body portion 23 by passing bolts through the mutually communicating bolt insertion holes 33a, 43a of the main body portion 23 and the front connecting portion 25 and fastening them with nuts. In this way, the front connecting portion 25 is placed over the main body portion 23 from above, and the overlapping portion of the side plate portion 33 of the main body portion 23 and the side plate portion 43 of the front connecting portion 25 is fastened with fastening members such as bolts and nuts, thereby easily connecting the main body portion 23 and the front connecting portion 25.

[0022] The rear connection portion 27 includes a front plate portion 51, an upper flange portion (flange portion) 53, a lower flange portion (flange portion) 55, and a pair of side flange portions (flange portions) 57, 57. The front plate portion 51 has a planar shape that is substantially perpendicular to the front-rear direction. The upper flange portion 53 extends from the upper edge of the front plate portion 51 toward the suspension cross member 19 side (rear side). The upper flange portion 53 has a protruding piece 63 that projects toward the suspension cross member 19 side, closer to the center in the vehicle width direction (see Figures 1, 2, 4, and 5). The lower flange portion 55 extends from the lower edge of the front plate portion 51 toward the suspension cross member 19 side. The lower flange portion 55 has a protruding piece 65 that projects toward the suspension cross member 19 side, closer to the outer side in the vehicle width direction (see Figure 5). The pair of side flange portions 57, 57 extend from both side edges of the front plate portion 51 in the vehicle width direction toward the suspension cross member 19 side (rear side). Each side flange portion 57 also has a connecting piece 67 that protrudes in the vehicle width direction at the end (rear end) on the suspension cross member 19 side. The connecting piece 67 of the rear connection portion 27 extends further outward in the vehicle width direction than the connecting piece 47 of the front connection portion 25.

[0023] The rear connection portion 27 has a pair of mounting pieces 35, 35 of the main body portion 23 abutting against its front plate portion 51. The pair of mounting pieces 35, 35 of the main body portion 23 and the front plate portion 51 of the rear connection portion 27 have bolt insertion holes 35a, 51a that communicate with each other when they are superimposed. For example, the rear connection portion 27 is attached to the main body portion 23 by passing a bolt through the mutually communicating bolt insertion holes 35a, 51a of the main body portion 23 and the rear connection portion 27 and fastening it with a nut. In this way, the main body portion 23 and the rear connection portion 27 can be easily connected by abutting the mounting pieces 35 of the main body portion 23 against the front plate portion 51 of the rear connection portion 27 and fastening the superimposed portion of the mounting pieces 35 of the main body portion 23 and the front plate portion 51 of the rear connection portion 27 with fastening members such as bolts and nuts.

[0024] As described above, the brace bars 21L and 21R, which consist of a main body portion 23, a front connecting portion 25, and a rear connecting portion 27, are positioned between the cross member 15 and the suspension cross member 19 (see Figure 1). Specifically, the brace bar 21L is positioned slightly to the left in the vehicle width direction between the cross member 15 and the suspension cross member 19, and the brace bar 21R is positioned slightly to the right in the vehicle width direction between the cross member 15 and the suspension cross member 19. The front connecting portion 25 of the brace bars 21L and 21R is joined to the cross member 15, and the rear connecting portion 27 is joined to the suspension cross member 19. It is preferable that the brace bars 21L and 21R be positioned near the fixed portion 19a on the suspension cross member 19 to which a load is input from the steering gearbox. Therefore, it is preferable that the positions of the brace bars 21L and 21R overlap with the fixed portion 19a in the vehicle width direction.

[0025] The front connection portion 25 is joined to the cross member 15 by a pair of flange portions 45, 45 that extend from a pair of side plate portions 43, 43 toward the cross member 15 (front side). Specifically, a joining piece 47 formed on the flange portion 45 of the front connection portion 25 and protruding in the vehicle width direction is superimposed on the rear surface of the cross member 15, and the edge of the joining piece 47 is arc welded to the cross member 15. In this way, the front connection portion 25 is joined to the cross member 15.

[0026] The rear connection portion 27 has an upper flange portion 53, a lower flange portion 55, and a pair of side flange portions 57 that extend from the front plate portion 51 toward the suspension cross member 19 side (rear side), and these are joined to the suspension cross member 19. Specifically, the protruding pieces 63 and 65 of the upper flange portion 53 and the lower flange portion 55 abut against the front surface of the suspension cross member 19, and the edges of these protruding pieces 63 and 65 are arc-welded to the suspension cross member 19. In addition, joining pieces 67 formed on the side flange portion 57 of the rear connection portion 27 and extending in the vehicle width direction are superimposed on the front surface of the suspension cross member 19, and the edges of these joining pieces 67 are arc-welded to the suspension cross member 19. In this way, the rear connection portion 27 is joined to the suspension cross member 19.

[0027] In this way, the front connecting portion 25 of the brace bars 21L and 21R is joined to the cross member 15, and the rear connecting portion 27 of the brace bars 21L and 21R is joined to the suspension cross member 19, thereby connecting the cross member 15 and the suspension cross member 19 by the brace bars 21L and 21R.

[0028] As described above, according to the vehicle structure of this embodiment, the cross member 15 and the suspension cross member 19 are connected by brace bars 21L and 21R, thereby increasing the strength of the suspension cross member 19 in the longitudinal direction of the vehicle. Furthermore, even in the event of a frontal collision of the vehicle 100, the brace bars 21L and 21R maintain the distance between the cross member 15 and the suspension cross member 19, thereby protecting the front suspension member 17.

[0029] Here, the brace bars 21L and 21R connecting the cross member 15 and the suspension cross member 19 are joined to the cross member 15 at the flange portion 45 of the front connecting portion 25, and to the suspension cross member 19 at the upper flange portion 53, lower flange portion 55, and side flange portion 57 of the rear connecting portion 27. In other words, the brace bars 21L and 21R are joined to the cross member 15 and the suspension cross member 19 via the flange portion 45, upper flange portion 53, lower flange portion 55, and side flange portion 57, which are easily elastically deformed by load. Therefore, even if relative stress is generated between the cross member 15 and the suspension cross member 19 from the steering gearbox or the like supported by the suspension cross member 19, the stress can be relieved by these flange portions (flange portion 45, upper flange portion 53, lower flange portion 55, and side flange portion 57), reducing stress concentration.

[0030] Thus, according to the vehicle structure of this embodiment, it is possible to realize a vehicle structure that prevents the space between the cross member 15 and the suspension cross member 19 from collapsing during a frontal collision, while suppressing stress concentration on the brace bars 21L and 21R.

[0031] Furthermore, the flange portion 45 of the front connection portion 25 and the side flange portion 57 of the rear connection portion 27 of the brace bars 21L and 21R each have connecting pieces 47 and 67 that protrude in the vehicle width direction, with connecting piece 47 being joined to the cross member 15 and connecting piece 67 being joined to the suspension cross member 19. Therefore, the ability to absorb stress in the vehicle width direction can be increased at the connection points of the brace bars 21L and 21R to the cross member 15 and the suspension cross member 19, and stress concentration on the brace bars 21L and 21R can be further reduced.

[0032] Furthermore, by configuring the brace bars 21L and 21R with a main body 23 and front and rear connecting parts 25 and 27 connected to the main body 23, relative stress between the cross member 15 and the suspension cross member 19 can be absorbed between the main body 23 and the front and rear connecting parts 25 and 27. In addition, by connecting the front and rear connecting parts 25 and 27 to the main body 23, the brace bars 21L and 21R connecting the cross member 15 and the suspension cross member 19 can be easily constructed.

[0033] Thus, the present invention is not limited to the embodiments described above. It is also intended and within the scope of protection to be provided for the combination of each configuration of the embodiments, as well as for modifications and applications by those skilled in the art based on the description in the specification and well-known technology.

[0034] As described above, the following matters are disclosed in this specification: (1) A vehicle structure comprising: a cross member extending in the width direction of the vehicle and constituting the frame of the vehicle; a suspension cross member positioned at the rear of the vehicle relative to the cross member; and a connecting member connecting the cross member and the suspension cross member, wherein the connecting member is joined to at least one of the cross member and the suspension cross member via a flange portion. With this vehicle structure, stress concentration on the connecting member connecting the cross member and the suspension cross member can be suppressed. Furthermore, even in the event of a frontal collision of the vehicle, the connecting member can maintain the distance between the cross member and the suspension cross member, thereby protecting the suspension member equipped with the suspension cross member.

[0035] (2) The vehicle structure according to (1), wherein the connecting member has flange portions on both sides in the vehicle width direction, the connecting pieces having been formed to extend toward the vehicle width direction, and the connecting pieces are joined to at least one of the cross member and the suspension cross member. With this vehicle structure, the ability to absorb stress in the vehicle width direction can be increased at the joints of the connecting member with the cross member and the suspension cross member, and stress concentration on the connecting member can be further reduced.

[0036] (3) The vehicle structure according to (1) or (2), wherein the connecting member comprises a main body and a connecting portion connected to the main body. With this vehicle structure, the relative stress between the cross member and the suspension cross member can be absorbed between the main body and the connecting portion of the connecting member.

[0037] (4) The vehicle structure according to (3), wherein the connecting portion comprises a first connecting portion attached to the cross member and a second connecting portion attached to the suspension cross member. With this vehicle structure, a connecting member that connects the cross member and the suspension cross member can be easily constructed by connecting the first connecting portion and the second connecting portion to the main body.

[0038] (5) The vehicle structure according to (4), wherein the first connecting part is placed over the main body from above and connected. With this vehicle structure, the main body and the first connecting part can be easily connected by placing the first connecting part over the main body from above and fastening the overlapping portion of the main body and the first connecting part with fastening members such as bolts and nuts.

[0039] (6) The vehicle structure according to (4) or (5), wherein the main body has a mounting piece extending in the vehicle width direction, and the mounting piece is connected to the second connecting portion. With this vehicle structure, the main body and the second connecting portion can be easily connected by fastening the mounting piece of the main body and the second connecting portion with fastening members such as bolts and nuts.

[0040] (7) The vehicle structure according to any one of (3) to (6), wherein the main body has a closed cross section. With this vehicle structure, high rigidity can be obtained because the main body has a closed cross section, and the strength between the cross member and the suspension cross member can be increased.

[0041] (8) The vehicle structure according to any one of (3) to (7), wherein the main body is formed in a U-shape with an open bottom and has a reinforcing plate assembled to close the bottom. With this vehicle structure, a highly rigid main body having a closed cross-section can be easily formed.

[0042] (9) The vehicle structure according to (8), wherein the reinforcing plate is positioned in the center of the main body in the vertical direction. With this vehicle structure, the main body can be reinforced in a balanced manner along the longitudinal direction by the reinforcing plate.

[0043] (10) The vehicle structure according to (8) or (9), wherein the reinforcing plate has a vertical wall portion extending in the vertical direction at at least one end. With this vehicle structure, the strength of the end of the reinforcing plate can be increased, thereby further increasing the rigidity of the main body.

[0044] 11 Frame 15 Cross member 17 Front suspension member 19 Suspension cross member 21L, 21R Brace bar (connecting member) 23 Main body 25 Front connection part (first connection part) 27 Rear connection part (second connection part) 31 Top plate part 33 Side plate part 35 Mounting piece 37 Reinforcement plate 39 Vertical wall part 41 Top plate part 43 Side plate part 45 Flange part 47 Joining piece 51 Front plate part 53 Upper flange part (flange part) 55 Lower flange part (flange part) 57 Side flange part (flange part) 63, 65 Protruding piece 67 Joining piece 100 Vehicle

Claims

1. A vehicle structure comprising: a cross member extending in the width direction of the vehicle and constituting the frame of the vehicle; a suspension cross member positioned behind the cross member of the vehicle; and a connecting member connecting the cross member and the suspension cross member, wherein the connecting member is joined to at least one of the cross member and the suspension cross member via a flange portion.

2. The vehicle structure according to claim 1, wherein the connecting member has flange portions on both sides in the vehicle width direction, the connecting pieces being formed to extend toward the vehicle width direction, and the connecting pieces are joined to at least one of the cross member and the suspension cross member.

3. The vehicle structure according to claim 1, wherein the connecting member comprises a main body and a connecting portion connected to the main body.

4. The vehicle structure according to claim 3, wherein the connecting portion comprises a first connecting portion attached to the cross member and a second connecting portion attached to the suspension cross member.

5. The vehicle structure according to claim 4, wherein the first connecting portion is connected by being placed over the main body portion from above.

6. The vehicle structure according to claim 4, wherein the main body portion has a mounting piece extending in the vehicle width direction, and the mounting piece is connected to the second connecting portion.

7. The vehicle structure according to claim 3, wherein the main body has a closed cross-section.

8. The vehicle structure according to claim 3, wherein the main body is formed in a U-shape with an open bottom and has a reinforcing plate assembled to close the bottom.

9. The vehicle structure according to claim 8, wherein the reinforcing plate is located in the center of the main body in the vertical direction.

10. The vehicle structure according to claim 8 or 9, wherein the reinforcing plate has a vertical wall portion extending in the vertical direction at at least one end.

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