Suspension mounting structure

Abstract

To provide a suspension attachment structure which enables improvement of support rigidity of an attachment part of a suspension arm attached to a vehicle body.SOLUTION: A suspension attachment structure includes: a side sill 4; a rear side member 5 which at least partially overlaps with the side sill 4; a battery protection member 6 which is located at a side of a battery 7 for driving a vehicle and overlaps with the side sill 4 and the rear side member 5; and a bracket 3 serving as a vehicle body attachment part of a rear suspension arm 2. The bracket 3 is fixed to a lower surface of the rear side member 5 and fixed to the side sill 4 and the battery protection member 6.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a suspension mounting structure for a vehicle. [Background technology]

[0002] Patent Document 1 below discloses a vehicle suspension mounting structure. More specifically, it discloses a mounting structure for a trailing arm of a rear suspension to a vehicle body frame. In this mounting structure, the front end of the trailing arm is attached to a suspension bracket fixed to the underside of a rear side member. The rear side member is joined to the side sill at the location of the suspension bracket. The suspension bracket fixed to the underside of the rear side member is also fixed to the side of the side sill. In other words, the front end of the trailing arm is attached to the rear side member and the side sill via the suspension bracket. A reinforcing member is also attached inside the side sill at the suspension bracket mounting portion. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-11199 Summary of the Invention [Problem to be solved by the invention]

[0004] However, even though the above-mentioned reinforcing members are attached, there is a demand for further improvement in the support rigidity of the trailing arm, i.e., the attachment portion of the suspension arm to the vehicle body.

[0005] An object of the present invention is to provide a suspension mounting structure that can improve the support rigidity of the mounting portion of a suspension arm to a vehicle body. [Means for solving the problem]

[0006] The suspension mounting structure according to the present invention includes a side sill and a rear side member that overlaps at least a portion of the side sill in the longitudinal direction of the vehicle. The suspension mounting structure also includes a battery protection member that is located to the side of the vehicle drive battery and overlaps both the side sill and the rear side member in the longitudinal direction of the vehicle. A suspension bracket, which serves as the vehicle body mounting portion of the rear suspension arm, is fixed to the underside of the rear side member and is also fixed to the side sill and the battery protection member. [Effects of the Invention]

[0007] According to the suspension mounting structure of the present invention, the support rigidity of the mounting portion of the suspension arm to the vehicle body can be improved. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view of a rear portion of a vehicle provided with suspension mounting structures according to an embodiment on the left and right sides, as viewed from below. [Figure 2] FIG. 10 is a bottom view of the mounting structure on the left side. [Figure 3] FIG. 2 is a perspective view of the right-side mounting structure as viewed from below and in front. [Figure 4] FIG. 4 is a perspective view of the right-side mounting structure as viewed from below and behind. [Figure 5] FIG. 10 is a cross-sectional view of a vertical section of the right-side mounting structure at the suspension arm vehicle body mounting point, as viewed from the front. [Figure 6] FIG. 4 is a left side view of the mounting structure on the left side. DETAILED DESCRIPTION OF THE INVENTION

[0009] A suspension mounting structure according to an embodiment will be described with reference to the drawings.

[0010] The suspension mounting structure according to this embodiment is shown in Figures 1 to 6. As shown in Figure 1, the suspension mounting structure according to this embodiment is a structure for mounting a rear suspension arm 2 of a rear suspension 1 to a vehicle body. The rear suspension 1 according to this embodiment is a torsion beam axle (TBA) type suspension, and a trailing arm 2 serving as the rear suspension arm 2 extends forward. The front end of the trailing arm 2 is attached to the vehicle body via a suspension bracket 3 (hereinafter simply referred to as bracket 3).

[0011] More specifically, the front end of the trailing arm 2 is attached via a bracket 3 to a side sill 4 and a rear side member 5, which are structurally important to the vehicle body, as well as to a battery protection member 6. The vehicle of this embodiment is a battery electric vehicle (BEV) that is not equipped with an internal combustion engine (ICE), and a battery 7 for driving the vehicle is mounted at the bottom of the vehicle body, covering almost the entire passenger compartment. The battery 7 is attached to the battery protection member 6 via multiple battery brackets, but the battery brackets are not shown in the drawing.

[0012] As shown in Figure 1, the mounting structure for this trailing arm 2 to the vehicle body is provided symmetrically on the right and left sides of the vehicle body. The following explanation will be made with reference to Figures 2 to 6, where Figures 2 and 6 show the mounting structure on the left side, and Figures 3 to 5 show the mounting structure on the right side. Figure 5 is a view of the right bracket 3 cut at a vertical cross section including the mounting center point of the trailing arm 2, viewed from the front to the rear.

[0013] The side sill 4 extends linearly in the longitudinal direction of the vehicle on the side of the floor of the vehicle body. As shown in FIG. 1, the rear end of the side sill 4 reaches the leading edge of the rear wheel arch. Although not shown in the figure, the leading end of the side sill 4 also reaches the trailing edge of the front wheel arch. A B-pillar extends from the center of the side sill 4 toward the roof panel. As shown in FIG. 5, the side sill 4 forms a closed cross section by joining an outer panel and an inner panel, each of which has a hat-shaped cross section, at their flanges. Reinforcing plates are also attached to the inside of the outer panel and inner panel.

[0014] The rear side member 5 is disposed inward in the vehicle width direction relative to the side sill 4 and extends in the vehicle longitudinal direction. In this embodiment, the front end of the rear side member 5 abuts against and is connected to a vertical wall 8a (see FIG. 3) that is part of the floor panel 8. As shown in FIGS. 1 and 5, the rear end of the rear side member 5 reaches the rear panel. As shown in FIG. 5, the rear side member 5 forms a closed cross section by joining a flange of a member having an inverted hat-shaped cross section to the floor panel 8. As shown in FIG. 2, the outer side surface of the rear side member 5 is also joined to the inner side surface of the side sill 4 at the overlapping portion with the side sill 4.

[0015] The battery protection member 6 extends in the vehicle longitudinal direction, outward of the battery 7 in the vehicle width direction and inward of the rear side member 5 in the vehicle width direction. That is, the battery protection member 6 extends in the vehicle longitudinal direction on the side of the battery 7, thereby protecting the battery 7 primarily from the side. As shown in FIG. 1 , the rearmost portion of the battery protection member 6 curves upward and inward, wrapping around above the battery 7, and its rear end reaches the rear panel. Also, although not shown, the front end of the battery protection member 6 is joined to the lower rear end of the front side member. As shown in FIG. 5 , the battery protection member 6 forms a closed cross section by joining an upper plate 6a to the flange of a member having an inverted hat-shaped cross section. However, in the portion forward of the above-mentioned vertical wall 8a and the portion wrapping around above the battery 7, the flange of the member having the inverted hat-shaped cross section is joined directly to the floor panel 8, not to the upper plate 6a.

[0016] The bracket 3 is formed by press-forming a steel plate, similar to the above-described side sill 4, rear side member 5, and battery protection member 6. The bracket 3 of this embodiment is formed by joining five pressed members together by spot welding. Hereinafter, the five members will be referred to as a first member 3a to a fifth member 3e.

[0017] As shown in FIGS. 2 to 5, the first member 3a is welded to the underside of the rear side member 5 and the inner side surface of the side sill 4. The first member 3a is also welded to the second member 3b and the third member 3c, which will be described later. As shown in FIG. 2, the first member 3a has a crank shape when viewed from the bottom, and a flange formed at its outer end (the upper end in FIG. 2) is welded to the inner side surface of the side sill 4. A flange formed at the inner end (the lower end in FIG. 2) of the first member 3a is welded to the second member 3b. The center of the crank shape of the first member 3a is formed as a vertical plate that is parallel to the vehicle fore-and-aft direction, and a mounting hole 30 (see FIGS. 3 and 4) for mounting the bush portion 2a at the front end of the trailing arm 2 is formed in this center.

[0018] A flange is formed on the upper edge of this central portion (the portion shown in cross section in FIG. 5), and this flange is welded to the underside of the rear side member 5. In addition, a flange is also formed on the upper edge of the connecting portion between the central portion and the outer end (see FIGS. 2 and 3), and this flange is also welded to the underside of the rear side member 5. In addition, the lower edge of the connecting portion between the central portion and the inner end (the portion shown by the dotted line in FIG. 5) is welded to a third member 3c (shown by the two-dot chain line in FIG. 5), which will be described later.

[0019] The second member 3b is a member that faces the first member 3a and holds the bushing portion 2a of the trailing arm 2. As shown in FIGS. 4 and 5, an upper portion of the second member 3b is welded to the inner side surface of the rear side member 5. As shown in FIGS. 2 to 4, a flange is formed in the front portion of the second member 3b, and this flange is also welded to the connection portion between the rear side member 5 and the vertical wall 8a. The second member 3b also has a mounting hole 30 (see FIG. 3) for mounting the bushing portion 2a.

[0020] As shown in Figures 2 and 4, the third member 3c is welded at its rear edge to the second member 3b described above, and is also welded near its front end to the underside of the rear side member 5 and the floor panel 8 at the connection between the rear side member 5 and the vertical wall 8a. As shown in Figure 2, a flange is formed on the inner edge of the third member 3c, and this flange is welded to the second member 3b described above. As shown in Figures 2 and 4, a flange is also formed on the outer edge of the third member 3c, and this flange is welded to the inner side surface of the side sill 4. The third member 3c is not shown in Figure 3. As the third member 3c is located in front of the cross section in Figure 5, its position is indicated by a two-dot chain line.

[0021] The second member 3b is fixed to the battery protection member 6 by a fourth member 3d and a fifth member 3e. As shown in FIG. 3, the fourth member 3d is a short angle member. A flange is formed on the outer edge of the fourth member 3d, and this flange is welded to the second member 3b described above. A mounting hole 30 (see FIG. 3) for mounting the bushing portion 2a of the trailing arm 2 is also formed in the flange of the fourth member 3d that is welded to the second member 3b. Therefore, the mounting portion of the bushing portion 2a of the bracket 3 is reinforced by the double layer of the second member 3b and the fourth member 3d.

[0022] The fifth member 3e is also a short angle member, as shown in Figure 3. The outer end of the fifth member 3e is welded to the inner end of the fourth member 3d. A flange is formed on the inner edge of the fifth member 3e, and this flange is welded to the bottom and side surfaces of the battery protection member 6.

[0023] Next, the positional overlapping relationship between the bracket 3 and the side sill 4, rear side member 5, and battery protection member 6, which extend in the vehicle longitudinal direction, will be described. These members satisfy the following (1) to (3): (1) At least a portion of the rear side member 5 overlaps with the side sill 4 in the vehicle longitudinal direction in a bottom view. (2) The battery protection member 6 overlaps with both the side sill 4 and the rear side member 5 in the vehicle longitudinal direction at least in a part of the overlapping area between the side sill 4 and the rear side member 5 in a bottom view. (3) The entire bracket 3 overlaps with the battery 7 in the vehicle longitudinal direction in a bottom view.

[0024] Note that "overlapping in the vehicle longitudinal direction in bottom view" means that there is a range of overlapping with each other in the vehicle longitudinal direction, but does not necessarily mean that they overlap with each other within that overlapping range in side view. In other words, "overlapping in the vehicle longitudinal direction" does not require overlapping in the vehicle vertical direction. However, in this embodiment, at the position where the bracket 3 is provided, the side sill 4, rear side member 5, battery protection member 6, and battery 7 also at least partially overlap with each other in the vehicle vertical direction in side view.

[0025] The above items (1) to (3) will be explained with reference to the bottom view of Fig. 2 and the side view of Fig. 6. As shown in Fig. 6, the above item (1) means that there is an overlapping area between the extension range C of the side sill 4 and the extension range B of the rear side member. Similarly, the above item (2) means that there is an overlapping area between the extension range C of the side sill 4 and the extension range B of the rear side member and the extension range E of the battery protection member 6. In this embodiment, the entire overlapping area between the extension range C and the extension range B is included in the extension range E.

[0026] Since the bracket 3 is joined to all of the side sill 4, rear side member 5, and battery protection member 6, it is disposed within the overlapping range of extension ranges B, C, and E. In other words, the range A of the bracket 3 in the vehicle longitudinal direction is included within the overlapping range of extension ranges B, C, and E. Finally, the above (3) means that the range A of the bracket 3 is included in the extension range D of the battery 7.

[0027] According to the mounting structure described above, the side sill 4, rear side member 5, and battery protection member 6, which provide structural strength and rigidity to the vehicle body, are joined together by the bracket 3, which is made up of the first member 3a to the fifth member 3e. As a result, the strength and rigidity of the vehicle body are improved in the area where the bracket 3 is provided.

[0028] Because the bracket 3 also serves as the vehicle body mounting portion for the trailing arm 2, the suspension mounting structure having the above-described configuration also improves the support rigidity of the rear suspension 1. This allows the rear suspension 1 to function more reliably, and also improves handling stability, vehicle dynamics, and ride comfort.

[0029] As described above, the bracket 3 is joined to the side sill 4, rear side member 5, and battery protection member 6, which provide structural strength and rigidity to the vehicle body, but these members have closed cross sections. Therefore, it is difficult to spot-weld the bracket 3 after the hat-shaped members constituting these members have been assembled into the vehicle body. Therefore, the bracket 3 is divided into the first member 3a through the fifth member 3e, and each member is spot-welded to the hat-shaped member in advance. The hat-shaped members are then assembled into the vehicle body to complete the side sill 4, rear side member 5, and battery protection member 6. The first member 3a through the fifth member 3e are then spot-welded to each other to complete the bracket 3. In other words, unless the bracket 3 is constructed by dividing it into the first member 3a through the fifth member 3e, it is difficult to assemble the side sill 4, rear side member 5, and battery protection member 6 into the vehicle body and spot-weld the bracket 3 to these members.

[0030] In this embodiment, a jack-up point 9 is set at a position adjacent to the bracket 3 of the side sill 4. The vehicle in this embodiment is a BEV that runs on power from a battery 7, which has a large volume and is heavy. BEVs tend to be heavier than internal combustion engine vehicles (ICEVs). For this reason, the jack-up point 9 is required to have higher strength. As described above, the portion where the bracket 3 is provided is the position where the side sill 4, rear side member 5, and battery protection member 6, which provide structural strength and rigidity to the vehicle body, are gathered, and these members are joined to each other by the bracket 3. In other words, the position where the bracket 3 is provided has high strength and is the optimal position for the jack-up point 9.

[0031] The suspension mounting structure according to this embodiment includes a side sill 4, a rear side member 5, and a battery protection member 6. The side sill 4 extends in the vehicle longitudinal direction on a side portion of the floor of the vehicle body. The rear side member 5 extends in the vehicle longitudinal direction inward of the side sill 4 in the vehicle width direction, and at least a portion of the rear side member 5 overlaps with the side sill 4 in the vehicle longitudinal direction in a bottom view (see (1) above). The battery protection member 6 extends in the vehicle longitudinal direction outward of a vehicle drive battery 7 disposed on the floor, and inward of the rear side member 5 in the vehicle width direction. Furthermore, the battery protection member 6 overlaps with both the side sill 4 and the rear side member 5 in the vehicle longitudinal direction in at least a portion of the overlapping area between the side sill 4 and the rear side member 5 in a bottom view (see (2) above).

[0032] Furthermore, the suspension bracket 3 that attaches the rear suspension arm 2 to the vehicle body is fixed to the underside of the rear side member 5, and is also fixed to the side sill 4 and the battery protection member 6. Therefore, the bracket 3 connects the side sill 4, rear side member 5, and battery protection member 6, which impart structural strength and rigidity to the vehicle body, to one another, improving the strength and rigidity of the vehicle body in the area where the bracket 3 is provided. Because the bracket 3 is also the vehicle body attachment portion of the rear suspension arm 2, it also improves the support rigidity of the rear suspension 1. As a result, the rear suspension 1 can function more reliably, and handling stability, vehicle dynamics, and ride comfort can also be improved.

[0033] Furthermore, according to the suspension mounting structure of this embodiment, the entire suspension bracket 3 overlaps with the battery 7 in the vehicle longitudinal direction in a bottom view (see (3) above). As described above, the strength and rigidity of the vehicle body are improved in the portion where the suspension bracket 3 is provided. This also applies to loads from the side of the vehicle body. Therefore, it is possible to effectively resist a side impact load input to the portion where the suspension bracket 3 is provided, and the above mounting structure can effectively protect the battery 7 from the side impact load.

[0034] Furthermore, according to the suspension mounting structure of this embodiment, a jack-up point 9 is set at a position adjacent to the suspension bracket 3 on the side sill 4. Although the vehicle weight increases due to the battery 7 used to drive the vehicle, by providing the jack-up point 9 adjacent to the portion of the vehicle where the suspension bracket 3 is located, where the strength and rigidity of the vehicle body are improved, the jack-up point 9 can effectively support the vehicle weight.

[0035] The suspension mounting structure of the present invention is not limited to the above-described embodiment. For example, in the above-described embodiment, as described above, the bracket 3, side sill 4, rear side member 5, battery protection member 6, and battery 7 at least partially overlap one another in the vehicle vertical direction in a side view. However, these members do not necessarily have to overlap one another in the vehicle vertical direction. Also, in the above-described embodiment, the battery protection member 6 extends to the rear panel to protect the battery 7 from a rear-end collision. However, the battery protection member 6 only needs to extend in the vehicle fore-and-aft direction at least to the side of the battery 7, and does not have to extend to the rear panel. [Explanation of symbols]

[0036] 1. Rear suspension 2 Trailing arm (rear suspension arm) 3 Suspension bracket 4 Side sill 5 Rear side member 6 Battery Protection Members 7. Battery (for driving vehicles) 9 Jacking points

Claims

1. A suspension mounting structure, a side sill extending in the front-rear direction of the vehicle on a side of a floor portion of the vehicle body; a rear side member extending in a vehicle longitudinal direction inward of the side sill in a vehicle width direction and at least a portion of which overlaps with the side sill in the vehicle longitudinal direction in a bottom view; a battery protection member that extends in the vehicle longitudinal direction outward in the vehicle width direction with respect to a battery for driving the vehicle that is disposed on the floor portion and inward in the vehicle width direction with respect to the rear side member, and that overlaps with both the side sill and the rear side member in the vehicle longitudinal direction in at least a portion of an overlapping area between the side sill and the rear side member in a bottom view; and a suspension bracket that attaches the rear suspension arm to the vehicle body. a suspension mounting structure, wherein the suspension bracket is fixed to the lower surface of the rear side member and is also fixed to the side sill and the battery protection member.

2. 2. The suspension mounting structure according to claim 1, wherein the suspension bracket entirely overlaps the battery in the vehicle front-rear direction in a bottom view.

3. 3. The suspension mounting structure according to claim 2, wherein a jack-up point is provided on the side sill at a position adjacent to the suspension bracket.

4. A suspension mounting structure as described in claim 1, wherein the battery protection member extends to the rear end of the vehicle in the fore-and-aft direction of the vehicle.

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