Vehicle frame structure

Abstract

At the joint between the cross member and the aluminum side member, twisting of the side member during a side collision is suppressed, and cracking of the side member is also suppressed. [Solution] A bracket 60 connects a side member 30 and a cross member 40. The side member 30 is a square tubular member made of aluminum. The cross member 40 is a square tubular member made of steel. The bracket 60 has an abutment wall 61 and a pair of clamping flanges 62, 67. The abutment wall 61 abuts against a tubular end portion 40A at the end of the cross member 40 in the vehicle width direction. The pair of clamping flanges 62, 67 extend outward in the vehicle width direction from the abutment wall 61 and clamp the side member 30 in the vertical direction.

Description

[Technical Field]

[0001] Disclosed herein is a vehicle frame structure. [Background technology]

[0002] The vehicle's framework includes side members and cross members. The side members are located on the outer sides of the vehicle width and extend in the front-to-rear direction of the vehicle. The cross members extend in the vehicle width direction. In other words, the cross members are located so as to cross from one side of the vehicle to the other.

[0003] For example, in Patent Document 1, both the side members (side frames) and the cross members (horizontal frames) are made of extruded aluminum. The ends of the cross members in the vehicle width direction are joined to the side members. The cross members are rectangular tubular. Multiple block-shaped ribs are provided on the sides of the side members. Slits are formed between adjacent ribs. The cross members are inserted into these slits.

[0004] In Patent Document 2, a bracket is interposed between the cross member and the side member (rocker). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 7-172349 [Patent Document 2] Japanese Patent Application Laid-Open No. 2017-24490 Summary of the Invention [Problem to be solved by the invention]

[0006] During a side collision, a collision load is applied to the side members inward in the vehicle width direction. At this time, the cross member holds the side members in place. If the center of gravity of the cross section of the side members is misaligned with the center of the cross member in the height direction, the side members may twist (collapse) around the center of gravity of the cross section.

[0007] Furthermore, if the cross member is rectangular, the side of the side member will make line contact with the end of the cross member. If the side member is made of aluminum, the deformation of the side member will be localized (point elongation). This means that, unlike uniform elongation, where the deformation point and its surroundings are uniformly deformed, the deformation load will be concentrated at the line contact point. This can lead to cracks occurring at the load-bearing points.

[0008] Therefore, this specification discloses a vehicle frame structure that can suppress twisting of the side members during a side collision at the joints between the cross members and the side members, and can also suppress cracking of the side members. [Means for solving the problem]

[0009] This specification discloses a vehicle frame structure. The structure includes a side member, a cross member, and a bracket. The side member extends in the fore-and-aft direction of the vehicle. The side member is disposed at an end in the vehicle width direction. The cross member extends in the vehicle width direction. The bracket connects the side member and the cross member. The side member is a square tubular member made of aluminum. The cross member is a square tubular member made of iron. The bracket includes an abutment wall and a pair of clamping flanges. The abutment wall abuts against the tubular end at the end of the cross member in the vehicle width direction. The pair of clamping flanges extend from the abutment wall outward in the vehicle width direction and clamp the side member in the up-and-down direction.

[0010] According to the above configuration, the abutment wall is inserted between the tubular end of the cross member and the side member. This prevents cracking of the side member during a side collision. Furthermore, the side member is clamped between the pair of clamping flanges. This prevents twisting of the side member during a side collision.

[0011] In the above configuration, the vehicle frame structure may include a battery pack. The battery pack is supported by being suspended from the side member. The bracket includes a battery flange. The battery flange is fastened to an upper wall of the battery pack.

[0012] According to the above-described configuration, the bracket is also fastened to the battery pack, so that the collision load received by the side member is distributed to the cross member and the frame of the battery pack.

[0013] In the above configuration, the vehicle frame structure may further include a battery pack. The battery pack is fastened to the lower wall of the side member. The battery pack is suspended and supported by the side member. The inner wall of the side member has a stepped structure. A relatively upper portion of the inner wall protrudes inward in the vehicle width direction beyond a relatively lower portion of the inner wall. Furthermore, a connecting portion is provided extending in the vehicle width direction. The connecting portion connects the upper portion and the lower portion. The lower of the pair of clamping flanges engages with the connecting portion.

[0014] According to the above configuration, the clamping flanges are caught on the connecting portion, so that the side member can be clamped by the pair of clamping flanges without interfering with the fastening structure between the battery pack and the side member.

[0015] In the above-described configuration, the side members may have ribs formed therein, the ribs extending in the vehicle width direction, and at least one of the upper wall and the lower wall of the cross member being aligned in height with the ribs.

[0016] According to the above configuration, it is possible to transmit the load from the rib to the cross member. [Effects of the Invention]

[0017] According to the vehicle frame structure disclosed in this specification, twisting of the side members during a side collision at the joints between the cross members and the side members is suppressed, and cracking of the side members can also be suppressed. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is an exploded perspective view illustrating a vehicle structure. [Figure 2] FIG. 2 is an exploded perspective view of the vehicle frame structure. [Figure 3] FIG. 3 is an exploded perspective view of the vehicle frame structure, facing in the opposite direction to FIG. 2. [Figure 4] FIG. 2 is a perspective view illustrating a vehicle frame structure around a bracket. [Figure 5] 5 is a cross-sectional view taken along the line AA in FIG. 4. [Figure 6] FIG. 2 is a cross-sectional view taken along line AA, illustrating a state in which a vehicle is involved in a side collision. DETAILED DESCRIPTION OF THE INVENTION

[0019] 1 to 6 show an example of a vehicle frame structure according to this embodiment. The vehicle frame structure according to this embodiment is mounted on an electric vehicle (BEV). The vehicle frame structure according to this embodiment includes a battery pack 10, a frame 20, a seat cross member 40, and a bracket 60.

[0020] In Figures 1 to 6, the front-to-rear direction of the vehicle is indicated by the FR axis. The width direction of the vehicle is indicated by the RW axis. The vertical direction is indicated by the UP axis. The positive direction of the FR axis is the front. The positive direction of the RW axis is the right direction. The positive direction of the UP axis is the height direction.

[0021] 2 to 6 illustrate the structure of the right side of the vehicle. However, based on the symmetrical structure of the vehicle body, the structure of the left side of the vehicle also corresponds to those shown in FIGS. 2 to 6.

[0022] 1. Vehicle structure FIG. 1 shows an exploded perspective view of a vehicle structure around the passenger compartment. A battery pack 10 is disposed under the floor of the passenger compartment. The battery pack 10 is supported by a frame 20. The frame 20 is a frame-shaped framework member. For example, the frame 20 supports the entire periphery of the battery pack 10.

[0023] A seat cross member 40 is fixed to the frame 20. The seat cross member 40 is a cross member extending in the vehicle width direction, for example. A pair of seat cross members 40 are provided side by side in the vehicle front-rear direction, for example.

[0024] A floor carpet 52 is laid on the frame 20 and the battery pack 10. In other words, the upper wall of the battery pack 10 also serves as a floor panel. Furthermore, a seat 54 is fastened to the seat cloth 40 through fastening holes 52A in the floor carpet.

[0025] 2. Battery pack 1, the battery pack 10 is a large box-shaped component. For example, the battery pack 10 is disposed on the floor of a vehicle compartment. The battery pack 10 supplies power to a rotating electric machine (not shown) that is a drive source for the vehicle. The battery pack 10 is suspended and supported by a frame 20.

[0026] 4, the battery pack 10 includes a battery case 11 and a plurality of battery cells 19. The battery case 11 houses the battery cells 19. The battery cells 19 are formed of, for example, nickel-metal hydride secondary batteries, lithium-ion secondary batteries, or all-solid-state batteries.

[0027] The battery case 11 includes an upper case 12 and a lower case 15. The upper case 12 and the lower case 15 include flanges 14, 17. Referring to Figure 5, the flanges 14, 17 are fastened to the bottom wall 38 of the side member 30 by bolts 16. With this fastening, the battery pack 10 is suspended and supported by the frame 20.

[0028] 3. Frame 1, the frame 20 is a skeleton member that is rectangular in plan view. The frame 20 includes a pair of frame cross members 22, 22 and a pair of side members 30, 30. The frame cross members 22 and the side members 30 are manufactured by extrusion molding of aluminum material.

[0029] The frame cross member 22 extends in the vehicle width direction and is connected to the ends of the side members 30 in the vehicle front-rear direction.

[0030] The side members 30 extend in the fore-and-aft direction of the vehicle. The side members 30 are also disposed at both ends of the vehicle in the vehicle width direction. The side members 30 are disposed, for example, at both ends of the vehicle interior in the vehicle width direction. The side members 30 are rectangular tubular members made of aluminum. That is, the side members 30 include an upper wall 32, an outer wall 34, an inner wall 36, and a lower wall 38. The side wall on the outer side in the vehicle width direction is the outer wall 34. The side wall on the inner side in the vehicle width direction is the inner wall 36. The thickness of these wall members may be equal to the thickness of the wall members of the seat cross 40.

[0031] Further, reinforcing ribs 37A, 37B, and 37C are formed inside the side member 30. The ribs 37A and 37B extend in the vehicle width direction. The rib 37C extends in the height direction. Referring to FIG. 2, the height H10 of the ribs 37A and 37B may be equal to the height H1 of the seat cloth 40. As will be described later, the height positions of the rib 37A and the lower wall 48 of the seat cloth 40 are aligned. Furthermore, the height positions of the rib 37B and the upper wall 42 of the seat cloth 40 are aligned. In other words, the rib 37A and the lower wall 48 are arranged on a horizontal plane. Similarly, the rib 37B and the upper wall 42 are arranged on a horizontal plane.

[0032] 5, a fastening hole 38A is drilled in a lower wall 38 of side member 30. Fastening hole 38A passes through lower wall 38. A weld nut 16A is provided inside side member 30. Weld nut 16A is disposed on lower wall 38 so as to be coaxial with fastening hole 38A.

[0033] As will be described later, clamping flanges 62, 67 that clamp the side member 30 from above and below are provided on the bracket 60. The upper clamping flange 62 faces the upper wall 32 of the side member 30. The lower clamping flange 67 faces the connecting portion 36C of the side member 30.

[0034] The inner wall 36 of the side member 30 has a stepped structure. This stepped structure includes an upper portion 36A, a lower portion 36B, and a connecting portion 36C. The upper portion 36A is a relatively upper portion of the inner wall 36. The lower portion 36B is a relatively lower portion of the inner wall 36. The upper portion 36A protrudes more inward in the vehicle width direction than the lower portion 36B. The connecting portion 36C connects the upper portion 36A and the lower portion 36B. The connecting portion 36C extends in the vehicle width direction.

[0035] The clamping flanges 62, 67 extend outward in the vehicle width direction from the abutment wall 61. The lower clamping flange 67 engages (gets caught on) the connecting portion 36C of the inner wall 36. In other words, the clamping flange 67 has a shape that does not interfere with fastening the battery pack 10 to the side member 30.

[0036] Additionally, fastening holes 32A are drilled in the top wall 32 of the side member 30. Additionally, weld nuts 32C are provided on the inner surface of the top wall 32. Fastening holes 62A are drilled in the clamping flange 62 of the bracket 60. The fastening holes 32A and 62A are aligned with each other, and bolts 62C are screwed in. In this way, the bracket 60 is fastened to the side member 30.

[0037] For example, the fastening surfaces between the bracket 60 and the side member 30 may be only one surface each of the clamping flange 62 and the upper wall 32. In other words, the abutment wall 61 and the upper portion 36A of the inner wall 36, as well as the clamping flange 67 and the connecting portion 36C, may not be fastened to each other.

[0038] 5, a reinforcing member 82 may be provided on the outer side of the side member 30 in the vehicle width direction. For example, in order to suppress cracking of the outer wall 34 during a side collision of the vehicle, the reinforcing member 82 is provided on the outer side of the outer wall 34. The reinforcing member 82 has, for example, a hat-shaped cross section and is welded to the outer wall 34.

[0039] 4. Seat cloth 1, the seat cross 40 is a frame member that supports the seat 54. For example, the bottom surface of the seat 54 is fastened to the seat cross 40 via a seat bracket (not shown).

[0040] The seat cross member 40 is a cross member extending in the vehicle width direction. For example, a pair of seat cross members 40 are provided spaced apart in the vehicle front-rear direction. The vehicle width direction ends of the seat cross members 40 are connected to the side members 30 via brackets 60. This connection structure will be described later.

[0041] 2, the seat cross 40 is a rectangular tubular member. That is, the seat cross 40 includes an upper wall 42, side walls 44 and 46, and a lower wall 48. A height dimension H1 of the seat cross 40 is smaller than a height dimension H3 of the side member 30 (see FIG. 3).

[0042] The sheet cloth 40 is, for example, a rectangular tubular member made of iron. The sheet cloth 40 is, for example, an electric resistance welded steel pipe. That is, the sheet cloth 40 is obtained by forming a steel material into a rectangular shape and then welding the seams.

[0043] The seat cross 40 has a fastening hole 42A drilled in the upper wall 42. Referring to Fig. 5, a weld nut 42C is provided on the inner surface of the upper wall 42. The bracket 60 also has a fastening hole 63A drilled in the cross flange 63.

[0044] When fastening the bracket 60 to the seat cross 40, the upper wall 42 and the cross flange 63 are brought into contact with each other. The fastening holes 42A of the upper wall 42 and the fastening holes 62A of the cross flange 63 are aligned. Then, the bolts 63C are threaded into the fastening holes 42A and 62A. This fastens the bracket 60 to the seat cross 40.

[0045] For example, the fastening surfaces between the bracket 60 and the seat cross 40 are only one surface each of the cross flange 63 and the top wall 42. That is, referring to FIG. 2, the cross flange 65 and the side wall 44, and the cross flange 64 and the side wall 46 may not be fastened together.

[0046] 5. Bracket 2 and 3, bracket 60 connects seat cross member 40 and side member 30. Bracket 60 is obtained by, for example, press-forming a steel material. The thickness of bracket 60 may be the same as that of seat cross member 40, for example.

[0047] The bracket 60 has a structure in which flanges protrude from the front and rear of an abutment wall 61, which is a main surface. Referring to Fig. 2, cross flanges 63, 64, 65 and a battery flange 66 extend inward in the vehicle width direction from the abutment wall 61. For example, the cross flanges 63, 64, 65 are erected relative to the abutment wall 61. The cross flanges 64, 65 are also disposed perpendicular to the cross flange 63. In other words, the cross flanges 63, 64, 65 form a wall structure that surrounds the bracket on three sides.

[0048] Furthermore, a rib 63B is provided to suppress bending deformation of the contact wall 61 relative to the cross flange 63. The rib 63B is formed across the contact wall 61 and the cross flange 63. Similarly, a rib 66B is formed across the cross flanges 64, 65 and the battery flange 66.

[0049] The width W2 of the cross flange 63 may be equal to the width W1 of the seat cross member 40. The width refers to the dimension along the longitudinal axis of the vehicle in FIG. 2. The height H2 of the cross flanges 64, 65 exceeds the height H1 of the seat cross member 40. That is, as illustrated in FIG. 4, when the seat cross member 40 is fastened to the bracket 60, the seat cross member 40 and the battery pack 10 are spaced apart in the height direction.

[0050] As described above, the seat cross 40 and the bracket 60 are fastened to each other via the upper wall 42 and the cross flange 63. The cross flanges 64, 65 then sandwich the seat cross 40 in the vehicle front-rear direction. In other words, the seat cross 40 is restrained by the cross flanges 64, 65.

[0051] The battery flange 66 is connected to the lower ends of the abutment wall 61 and the cross flanges 64, 65. The battery flange 66 extends perpendicular to the abutment wall 61 and the cross flanges 64, 65. Fastening holes 66A are drilled in the battery flange 66 for fastening to the battery pack 10 (see FIG. 4).

[0052] 3, sandwiching flanges 62, 67 extend outward in the vehicle width direction from contact wall 61. For example, sandwiching flanges 62, 67 are erected relative to contact wall 61. Sandwiching flanges 62, 67 are erected in the opposite direction to cross flanges 63, 64, 65.

[0053] A separation distance H4 in the height direction between the sandwiching flanges 62, 67 may be the same as the height dimension H3 of the upper portion 36A of the side member 30. In other words, the sandwiching flanges 62, 67 sandwich the side member 30 in the up-down direction.

[0054] 6. Joint structure between side member and seat cloth Referring to FIG. 3, the clamping flanges 62, 67 of the bracket 60 clamp the side member 30. In this state, the fastening holes 62A, 32A are aligned. The bracket 60 clamps the side member 30 in the up-and-down direction, but does not restrict it in the fore-and-aft direction of the vehicle. Therefore, the fastening holes 62A, 32A are aligned by sliding the bracket 60 relative to the side member 30. After the alignment, a bolt 62C (see FIG. 5) is screwed into the fastening holes 62A, 32A. In this way, the bracket 60 is fastened to the side member 30.

[0055] 2, the seat cross 40 is fitted into the cross flanges 63, 64, and 65. For example, the seat cross 40 may be fastened to the side members 30 at both ends in the vehicle width direction. In such a case, the seat cross 40 is inserted into the U-shaped enclosure formed by the cross flanges 63, 64, and 65 from below the enclosure.

[0056] When the fastening holes 42A, 62A are aligned, the bolt 63C (see FIG. 5) is screwed in. This fastens the seat cross 40 to the bracket 60. That is, the seat cross 40 and the side member 30 are fastened together via the bracket 60.

[0057] 5, the upper wall 42 of the seat cross member 40 is aligned in height with the rib 37B. The lower wall 48 is aligned in height with the rib 37A. This arrangement allows for smooth load transmission from the side member 30 to the seat cross member 40. Instead of the configuration shown in FIG. 5, at least one of the upper wall 42 and the lower wall 48 may be aligned in height with the ribs 37A and 37B.

[0058] 5, a tubular end portion 40A at the end of the seat cross member 40 in the vehicle width direction abuts against an abutment wall 61 of a bracket 60. The side member 30 is clamped between clamping flanges 62, 67 in the vertical direction.

[0059] Furthermore, the battery flange 66 of the bracket 60 is fastened to the upper wall of the battery pack 10. Specifically, the battery flange 66 and the upper case 12 are fastened together with bolts 66C (see FIG. 4).

[0060] Referring to Fig. 6, vehicle crash tests include a crash test using a mobile progressive deformable barrier. In this test, a barrier collides with a parked vehicle. In a vehicle side crash test using a mobile progressive deformable barrier, as shown in Fig. 6, a rocker panel 80 collides with a barrier 90. The barrier 90 enters, for example, from above the side member 30, toward the inside in the vehicle width direction.

[0061] At this time, the side member 30 receives the collision load from the barrier 90. The side member 30 is further supported by the seat cross member 40. At this time, a moment is generated in the side member 30 in the counterclockwise direction on the page, twisting it about the cross-sectional center of gravity P1.

[0062] This twisting of the side member 30 is suppressed by the sandwiching flanges 62, 67. That is, the sandwiching flanges 62, 67 sandwich the side member 30 from above and below, suppressing deformation of the side member 30.

[0063] Furthermore, when the seat cross 40 receives the side member 30, the tube end 40A of the seat cross 40 abuts against the inner wall 36 of the side member 30 via the abutment wall 61. That is, the load (reaction load) of the tube end 40A is input to the inner wall 36 in a state where it is dispersed over the surface by the abutment wall 61. This suppresses cracking of the inner wall 36. [Explanation of symbols]

[0064] 10 battery pack, 11 battery case, 20 frame, 30 side member, 32 upper wall of side member, 34 outer wall of side member, 36 inner wall of side member, 36A upper part, 36B lower part, 36C connection part, 38 lower wall of side member, 40 seat cross (cross member), 40A tube end, 42 upper wall of seat cross, 44, 46 side walls of seat cross, 48 ​​lower wall of seat cross, 60 bracket, 61 abutment wall of bracket, 62, 67 clamping flange of bracket, 63, 64, 65 cross flange of bracket, 66 battery flange.

Claims

1. a side member extending in the vehicle front-rear direction and disposed at an end in the vehicle width direction; A cross member extending in the vehicle width direction; a bracket that connects the side member and the cross member; Equipped with The side members are rectangular tube members made of aluminum, The cross member is a rectangular tube member made of iron, The bracket is a contact wall that contacts a tube end portion at a vehicle width direction end of the cross member; a pair of clamping flanges extending outward in the vehicle width direction from the abutment wall and clamping the side member in the up-down direction; A vehicle frame structure comprising:

2. 2. A vehicle frame structure according to claim 1, a battery pack suspended and supported by the side members; The bracket includes a battery flange fastened to an upper wall of the battery pack. Vehicle frame structure.

3. 2. A vehicle frame structure according to claim 1, a battery pack fastened to a lower wall of the side member and suspended and supported by the side member; the inner wall of the side member has a stepped structure, a relatively upper portion of the inner wall protrudes more inward in the vehicle width direction than a relatively lower portion of the inner wall, and a connecting portion connecting the upper portion and the lower portion extends in the vehicle width direction; The lower one of the pair of clamping flanges engages with the connecting portion. Vehicle frame structure.

4. 2. A vehicle frame structure according to claim 1, The side members each have a rib formed therein that extends in the vehicle width direction, At least one of the upper wall and the lower wall of the cross member is aligned in height with the rib. Vehicle frame structure.

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