Vehicle rear structure

Abstract

To provide a vehicle rear part structure capable of improving strength performance and NV performance of a rear floor panel.SOLUTION: A vehicle rear part structure includes: a rear floor panel 10; a pair of rear side members 16R, 16L; a first cross member 18; a second cross member 20 installed closer to the rear side of a vehicle than the first cross member 18; and one or more brackets 30R, 30L for components to which electrical components 22R, 22L are fastened and which are joined to the rear floor panel 10. A part of the brackets 30R, 30L for components are joined to be overlapped with the rear side members 16R, 16L and the rear floor panel 10. A longitudinal dimension L3 of the brackets 30R, 30L for components is at least 50% of the longitudinal dimension of the inner region 12 which is a portion surrounded by the pair of rear side members 16R, 16L, the first cross member 18 and the second cross member 20 of the rear floor panel 10.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] This specification discloses a rear structure for a vehicle on which electrical components are mounted. [Background technology]

[0002] Electrical components such as an inverter are often mounted in the rear of a vehicle. Many techniques for mounting the electrical components have been proposed in the past. For example, Patent Document 1 discloses a technique for mounting an inverter, which is an electrical component, to a rear floor panel via a bracket. In Patent Document 1, the bracket is fixed to a rear side member and a cross member. With such a configuration, deformation of the rear floor panel can be suppressed to a certain degree. That is, when the electrical components are tilted during driving on rough roads, the electrical components pull the rear floor panel, causing deformation. In the technique of Patent Document 1, the bracket is attached to a frame part, so that tilting of the bracket and therefore the electrical components is suppressed, and deformation of the rear floor panel caused by the tilting of the electrical components can be prevented. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-147058 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the bracket in Patent Document 1 is intended only for mounting electrical components, and the size of the bracket is significantly smaller than that of the rear floor panel. Therefore, with the bracket in Patent Document 1, a difference in rigidity occurs between the rear floor panel and the frame parts that are more rigid than the rear floor panel, which may cause stress concentration and, ultimately, deformation of the panel. In addition, since the rigidity of the entire rear floor panel is not sufficiently improved, there is a risk of vibration of the panel. In other words, the technology in Patent Document 1 has room for improvement in the strength performance and noise and vibration performance (hereinafter referred to as "NV performance") of the rear floor panel.

[0005] Here, in order to improve the strength performance and NV performance of the rear floor panel, it is possible to increase the plate thickness of the rear floor panel. However, increasing the plate thickness of the rear floor panel leads to other problems such as increased weight and increased costs. Therefore, it has been proposed to locally reinforce the rear floor panel by joining another panel material (i.e., a reinforcing member) to the rear floor panel without increasing the plate thickness of the rear floor panel.

[0006] However, providing a reinforcing member separate from the bracket for mounting the electrical components results in an increase in the number of parts. Also, if a bracket is present, the reinforcing member can only be provided in an area that avoids the bracket, which limits the area that can be reinforced. As a result, with the conventional technology, it is difficult to adequately reinforce the rear floor panel, and the strength performance and NV performance of the rear floor panel cannot be sufficiently improved.

[0007] Therefore, this specification discloses a vehicle rear structure equipped with electrical components, which can improve the strength performance and NV performance of the rear floor panel while suppressing increases in weight and cost. [Means for solving the problem]

[0008] The vehicle rear structure disclosed in this specification comprises a rear floor panel that functions as a floor surface of the rear of the vehicle, a pair of rear side members provided at both ends of the rear floor panel in the vehicle width direction and extending in the fore-and-aft direction of the vehicle, a first cross member that is suspended between the pair of rear side members, a second cross member that is suspended between the pair of rear side members rear of the vehicle from the first cross member, and one or more component brackets to which electrical components are fastened and that are joined to the rear floor panel in a state overlapped on the rear floor panel, wherein a portion of the component bracket overlaps with the rear side member in a top view, and the rear side member, the rear floor panel, and the component bracket are joined to each other in an overlapping state at this overlapping portion, and the fore-and-aft dimension of the component bracket is more than 50% of the fore-and-aft dimension of an inner region of the rear floor panel that is surrounded by the pair of rear side members, the first cross member, and the second cross member.

[0009] The component bracket, to which the electrical components are fastened, is fastened to the rear side member, and the fore-aft dimension of the component bracket is set to 50% or more of the fore-aft dimension of the inner region, so that the component bracket functions as a reinforcing member that reinforces a wide area of ​​the rear floor panel. In other words, the component bracket not only functions as a bracket, but also as a reinforcing member. As a result, deformation and vibration of the rear floor panel can be effectively suppressed without increasing the plate thickness of the rear floor panel. As a result, the strength performance and NV performance of the rear floor panel can be improved while suppressing increases in weight and cost.

[0010] In this case, the component bracket may cross in the vehicle front-rear direction a reinforcing bead having the largest planar size among the one or more beads formed in the inner region.

[0011] Stress tends to concentrate near the periphery of the reinforcing bead. By having the component bracket cross this reinforcing bead in the front-to-rear direction, stress concentration is alleviated and deformation and vibration of the rear floor panel are more effectively suppressed.

[0012] In addition, a canister bracket for mounting an exhaust canister is further joined to the rear surface of the rear floor panel, and at least one of the one or more component brackets overlaps with the canister bracket when viewed from above, and at this overlapping portion, the canister bracket, the rear floor panel, and the component bracket are joined to each other in an overlapping state.

[0013] With this configuration, the rigidity of the component bracket is improved, and the rear floor panel is more strongly reinforced, resulting in more effective suppression of deformation and vibration of the rear floor panel.

[0014] In addition, two component brackets in total are provided, one on each end of the rear floor panel in the vehicle width direction, and one component bracket is joined to each of the pair of rear side members.

[0015] By providing component brackets on both the left and right sides of the vehicle, torsional deformation of the rear floor panel is effectively suppressed.

[0016] In addition, the vehicle width direction dimension of the part bracket may be larger than the vehicle width direction dimension of the inner region, and the right end of the part bracket may be joined to the right rear side member, and the left end of the part bracket may be joined to the left rear side member, together with the rear floor panel.

[0017] With this configuration, a wide area of ​​the rear floor panel can be reinforced with the component bracket, so deformation and vibration of the rear floor panel can be more effectively suppressed.

[0018] In addition, at least one of a front portion and a rear portion of the component bracket may be joined to at least one of the second cross member and the first cross member, together with the rear floor panel.

[0019] With this configuration, the rigidity of the component bracket is further improved, and deformation and vibration of the rear floor panel are more effectively suppressed.

[0020] Further, an area of ​​the component bracket that does not overlap with the electrical component in a top view may be larger than an area that overlaps with the electrical component in a top view.

[0021] The area of ​​the component bracket that does not overlap with the electrical components is usually considered to be a portion that does not function as a bracket. Because this portion that does not function as a bracket is large, the component bracket can reinforce a wide area of ​​the rear floor panel. As a result, deformation and vibration of the rear floor panel are more effectively suppressed. Effect of the Invention

[0022] The technology disclosed in this specification makes it possible to improve the strength performance and NV performance of a rear floor panel while suppressing increases in weight and cost. [Brief description of the drawings]

[0023] [Figure 1] FIG. 2 is a schematic perspective view of the rear of the vehicle. [Diagram 2] FIG. 2 is a schematic exploded perspective view of the rear of the vehicle. [Diagram 3] FIG. [Figure 4] FIG. 4 is a diagram illustrating the dimensional relationship at the rear of the vehicle. [Diagram 5] 5 is a cross-sectional view taken along the line AA in FIG. [Figure 6] 10A and 10B are diagrams for explaining locations where stress is likely to concentrate when there is no component bracket. [Figure 7] 13A and 13B are diagrams showing an example of another component bracket. [Figure 8] 13A and 13B are diagrams showing an example of another component bracket. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] The vehicle rear structure will be described below with reference to the drawings. In each drawing, "Fr", "Up", and "Rh" respectively mean the front, upper, and right side of the vehicle. In each drawing, the component bracket 30 is hatched for ease of understanding.

[0025] 1 and 2, the rear of the vehicle is provided with a rear floor panel 10, a right rear side member 16R, a left rear side member 16L, a first cross member 18, and a second cross member 20. In the following description, when there is no need to distinguish between the right rear side member 16R and the left rear side member 16L, the suffixes R and L will be omitted and they will be referred to as "rear side member 16."

[0026] The rear floor panel 10 is a panel material that functions as the floor surface of the rear part of the vehicle. The rear floor panel 10 is joined by welding to a pair of rear side members 16, a first cross member 18, and a second cross member 20, which are framework members. The rear floor panel 10 may be made of a single panel material, or may be made by connecting multiple panel materials in the surface direction.

[0027] The rear side member 16 is a frame member that is long in the front-rear direction of the vehicle and has higher rigidity than the rear floor panel 10. In this example, the rear side member 16 has a generally groove shape that opens toward the upper side of the vehicle. The rear side member 16 is joined to the bottom surface of the rear floor panel 10 by welding.

[0028] The first cross member 18 is a skeletal member that is long in the vehicle width direction and is a member with higher rigidity than the rear floor panel 10. Both ends of the first cross member 18 in the vehicle width direction are joined to the pair of rear side members 16. In other words, the first cross member 18 is suspended between the pair of rear side members 16. In this example, the first cross member 18 has a generally groove shape that opens downwardly of the vehicle. The first cross member 18 is joined to the upper surface of the rear floor panel 10 by welding.

[0029] The second cross member 20 is a skeletal member that is long in the vehicle width direction and is a member with higher rigidity than the rear floor panel 10. This second cross member 20 is disposed rearward of the first cross member 18. Both ends of the second cross member 20 in the vehicle width direction are joined to a pair of rear side members 16. In other words, the second cross member 20 is suspended between the pair of rear side members 16. In this example, the second cross member 20 has a generally groove shape that opens toward the top of the vehicle. This second cross member 20 is joined to the bottom surface of the rear floor panel 10 by welding.

[0030] Here, the rear floor panel 10 has an area surrounded by a pair of rear side members 16, a first cross member 18, and a second cross member 20. Hereinafter, this area will be referred to as the "inner area 12." Note that, in order to clearly distinguish the boundaries from lines of other members, the boundaries of the inner area 12 are only shown in Figures 2 and 4. Also, in Figure 4, the reference numerals of some elements have been omitted in order to clarify the dimension lines.

[0031] In the inner region 12, a reinforcing bead 14 is formed which is locally raised upward. Although not shown in the drawings, the actual rear floor panel 10 has many other raised and depressed portions in addition to the reinforcing bead 14. The reinforcing bead 14 is the bead with the largest planar size among the multiple beads provided in the inner region 12. More specifically, as shown in Figs. 3 and 4, the reinforcing bead 14 spans almost the entire width of the inner region 12, and the vehicle width direction dimension W2 of the reinforcing bead 14 is 80% or more of the vehicle width direction dimension W1 of the inner region 12 (i.e., the distance from the left end of the right rear side member 16R to the right end of the left rear side member 16L). In addition, the vehicle front-rear direction dimension L2 of the reinforcing bead 14 is 30% or more of the vehicle front-rear direction dimension L1 of the inner region 12 (i.e., the distance from the rear end of the first cross member 18 to the front end of the second cross member 20).

[0032] As is apparent from Figs. 1 and 2, a right component bracket 30R and a left component bracket 30L are joined to the upper surface of the rear floor panel 10. In the following, when there is no need to distinguish between the right component bracket 30R and the left component bracket 30L, they will be referred to as "component bracket 30". This component bracket 30 functions as a reinforcing member that reinforces the rear floor panel 10, and also functions as a bracket for mounting a branch box 22R and an inverter 22L, which will be described later. The detailed configuration of the component bracket 30 will be described later.

[0033] The inverter 22L is an electrical component that converts power from DC to AC or AC to DC. The branch box 22R is an electrical component that collects multiple electrical wirings. Hereinafter, when there is no need to distinguish between the branch box 22R and the inverter 22L, they will be referred to as "electrical components 22."

[0034] The front part of the electrical component 22 is fixed to the first cross member 18, and the rear part of the electrical component 22 is fixed to the rear floor panel 10 via a component bracket 30. Specifically, a first bracket 24 is fixed to the front part of the electrical component 22, and a tip of the first bracket 24 is fastened to the first cross member 18. A second bracket 26 is fixed to the rear part of the electrical component 22, and the second bracket 26 is fastened to the component bracket 30. The component bracket 30 is provided with fastening holes 36 (see Figs. 2 and 3) for fastening to the second bracket 26. As shown in Fig. 1, in this example, the branch box 22R is fastened to the right component bracket 30R, and the inverter 22L is fastened to the left component bracket 30L.

[0035] Next, a detailed description will be given of the configuration of the component bracket 30. As described above, the component bracket 30 is a panel material that is joined by welding to the upper surface of the rear floor panel 10. The component bracket 30 is sized to straddle the reinforcing bead 14 in the vehicle front-rear direction, and its outer end in the vehicle width direction overlaps with the rear side member 16 in a top view.

[0036] The component bracket 30 has an island-shaped raised portion 32 that is raised from the surrounding area. A fastening hole 36 for fastening the electrical component 22 is formed in this island-shaped raised portion 32. A weld nut (not shown) is provided on the rear surface of the component bracket 30 at a position concentric with the fastening hole 36. When fixing the electrical component 22, the fastening hole of the second bracket 26 is aligned with the fastening hole 36, and a fastening bolt (not shown) is screwed into the weld nut.

[0037] That is, the component bracket 30 functions as a bracket for fixing the electrical component 22 to the rear floor panel 10. However, the component bracket 30 is sufficiently larger in size than the size required for the bracket to function. That is, the electrical component 22 is fastened only to the fastening holes 36 of the island-shaped raised portion 32. Therefore, if the component bracket 30 is only to be used as a bracket, it is sufficient for the component bracket 30 to be approximately one size larger than the island-shaped raised portion 32. However, in this example, as shown in FIG. 3, the component bracket 30 is sufficiently larger than the island-shaped raised portion 32.

[0038] 4, the vehicle front-rear direction dimension L3 of the component bracket 30 is equal to or more than 50% of the vehicle front-rear direction dimension L1 of the inner region 12. As described above, the component bracket 30 crosses the reinforcing bead 14, which is the largest bead in the inner region 12, in the vehicle front-rear direction. It can also be said that the range of the component bracket 30 that does not overlap with the electrical component 22 in a top view is larger than the range that overlaps with the electrical component 22 in a top view.

[0039] As described above and as shown in Figs. 3 and 4, the outer end of the part bracket 30 in the vehicle width direction overlaps with the rear side member 16 in a top view. Specifically, the right part bracket 30R has its right end overlapping with the right rear side member 16R, and the left part bracket 30L has its left end overlapping with the left rear side member 16L. In this overlapping portion, the rear side member 16, the rear floor panel 10, and the part bracket 30 are joined by welding in an overlapping state. The black circles in Figs. 3 and 4 indicate the joint points 50a between the part bracket 30 and the rear floor panel 10, and the cross marks in Figs. 3 and 4 indicate the joint points 50b between the part bracket 30, the rear floor panel 10, and the rear side member 16. Fig. 5 is a cross-sectional view taken along line AA in Fig. 4.

[0040] As is clear from the above description, in this embodiment, the component bracket 30 is joined to the rear side member 16, and is made larger than the size required for the component bracket 30 to function as a mounting bracket. The reason for this configuration will be explained.

[0041] As stated repeatedly, the electrical component 22 is fastened only to the island-shaped raised portion 32 of the component bracket 30. Therefore, if the component bracket 30 is used only as a mounting bracket for the electrical component 22, a size of the component bracket 30 that is slightly larger than the island-shaped raised portion 32 is sufficient. However, as described above, in this example, the component bracket 30 is made significantly larger than the island-shaped raised portion 32. The reason for this configuration is that the component bracket 30 is also used as a reinforcing member for the rear floor panel 10.

[0042] That is, if there is no component bracket 30 or if the component bracket 30 is small, the difference in rigidity between the high-rigidity frame member and the low-rigidity rear floor panel 10 becomes large. As a result, stress is likely to concentrate in weak parts of the rear floor panel 10, which is likely to cause deformation or vibration of the rear floor panel 10. In particular, stress is likely to concentrate in the inner region 12, near the rear side member 16, at the base of the rising edge of the reinforcing bead 14, and around the corners of the reinforcing bead 14, i.e., the cross-hatched areas in FIG. 6.

[0043] In order to alleviate such rigidity differences and stress concentrations, in this example, a part of the component bracket 30 joined to the rear floor panel 10 is also joined to the rear side member 16. With this configuration, a part of the load transmitted to the component bracket 30 and the rear floor panel 10 is distributed to the high-rigidity rear side member 16, and stress concentration is alleviated. In addition, by making the component bracket 30 a size and shape that covers a relatively wide area of ​​the rear floor panel 10, especially the areas where stress is likely to concentrate, the rigidity differences can be alleviated and stress concentration can be alleviated. As a result, deformation and vibration of the rear floor panel 10 can be effectively suppressed, and the strength performance and NV performance of the rear floor panel 10 can be effectively improved.

[0044] Furthermore, without the parts bracket 30, the rear floor panel 10 is prone to deformation such that the entire inner region 12 is twisted. That is, the inner region 12 is prone to deformation such that one of the left and right ends of the inner region 12 is twisted upward toward the front and the other is twisted upward toward the rear. In this example, a right parts bracket 30R joined to the right rear side member 16R and a left parts bracket 30L joined to the left rear side member 16L are provided. In this way, by providing the parts brackets 30 on both the left and right sides, the twisting deformation of the rear floor panel 10 can be effectively suppressed.

[0045] In this example, the component bracket 30 is used as a reinforcing member that suppresses deformation of the rear floor panel 10, and is also used as a mounting bracket that mounts the electrical component 22 to the rear floor panel 10. With this configuration, the number of components can be reduced compared to when the reinforcing member and the mounting bracket are prepared separately.

[0046] Although not shown in Figures 1 to 3, an exhaust canister 40 (see Figure 4) containing a purification material for purifying exhaust gas is disposed below the rear floor panel 10. The exhaust canister 40 is suspended and supported by two canister brackets 42L, 42R. Both canister brackets 42L, 42R are joined to the rear surface of the rear floor panel 10 by welding.

[0047] 4, the inner end of the right component bracket 30R in the vehicle width direction overlaps with the canister bracket 42R in a top view, and in this overlapping portion, the right component bracket 30R, the rear floor panel 10, and the canister bracket 42R are overlapped with each other and joined by welding. With this configuration, the rear floor panel 10 is more strongly reinforced, and the strength performance and NV performance of the rear floor panel 10 are further improved.

[0048] The configuration described above is merely an example, and other configurations may be changed as long as the component bracket 30 joined to the rear floor panel 10 is capable of mounting the electrical components 22, is joined to the rear side member 16, and has a front-to-rear dimension L3 that is 50% or more of the front-to-rear dimension L1 of the inner region 12. Therefore, the shape, etc. of the component bracket 30 may be changed as appropriate.

[0049] In the above example, the component bracket 30 is not joined to the first cross member 18 and the second cross member 20. However, the component bracket 30 may be shaped to overlap at least one of the first cross member 18 and the second cross member 20 in a top view, and may be joined to at least one of the first cross member 18 and the second cross member 20. Therefore, for example, as shown in FIG. 7, the front part of the right component bracket 30R may be joined to the first cross member 18, and the rear part may be joined to the second cross member 20. In FIG. 7, the black triangle indicates a joining point 50c where the right component bracket 30R, the rear floor panel 10, and the first cross member 18 or the second cross member 20 are joined to each other. With such a configuration, the rigidity difference can be more reliably alleviated, and deformation of the rear floor panel 10 can be more reliably suppressed. Furthermore, as long as the fore-aft dimension L3 of the component bracket 30 is equal to or more than 50% of the fore-aft dimension L1 of the inner region 12, the component bracket 30 may have a shape that does not cross the reinforcing bead 14 in the fore-aft direction, as in the left component bracket 30L in Figure 7.

[0050] In addition, in the above description, two component brackets 30 are provided, one on each side, but only one component bracket 30 may be provided. In other words, only one of the right component bracket 30R and the left component bracket 30L, which has a smaller vehicle width dimension than the inner region 12, may be provided.

[0051] 8, the component bracket 30 may have a vehicle width dimension larger than the vehicle width dimension W1 of the inner region 12. In this case, the right end of the component bracket 30 is joined to the right rear side member 16R, and the left end is joined to the left rear side member 16L, both of which are joined to the rear floor panel 10. With this configuration, a wider range can be reinforced, and deformation and vibration of the rear floor panel 10 can be more reliably prevented. [Explanation of symbols]

[0052] 10 rear floor panel, 12 inner area, 14 reinforcing bead, 16L left rear side member, 16R right rear side member, 18 first cross member, 20 second cross member, 22L inverter (electrical component), 22R branch box (electrical component), 24 first bracket, 26 second bracket, 30 component bracket, 30L left component bracket, 30R right component bracket, 32 island-shaped raised portion, 36 fastening hole, 40 exhaust canister, 42L, 42R canister bracket, 50a, 50b, 50c joint points.

Claims

1. The rear floor panel functions as the floor surface at the rear of the vehicle. a pair of rear side members provided at both ends of the rear floor panel in a vehicle width direction and extending in a vehicle front-rear direction; a first cross member disposed between the pair of rear side members; a second cross member that is disposed between the pair of rear side members and is located rearward of the first cross member; one or more component brackets to which electrical components are fastened and which are joined to the rear floor panel in a state of being overlapped on the rear floor panel; a portion of the component bracket overlaps with the rear side member in a top view, and the rear side member, the rear floor panel, and the component bracket are joined to one another in an overlapping state at the overlapping portion, a front-rear dimension of the component bracket is equal to or greater than 50% of a front-rear dimension of an inner region of the rear floor panel that is a portion surrounded by the pair of rear side members, the first cross member, and the second cross member, a range of the component bracket that does not overlap with the electrical component in a top view is larger than a range of the component bracket that overlaps with the electrical component in a top view; A vehicle rear structure comprising:

2. 2. The vehicle rear structure according to claim 1, the component bracket crosses in a vehicle front-rear direction a reinforcing bead having a largest planar size among the one or more beads formed in the inner region, A vehicle rear structure comprising:

3. 3. A vehicle rear structure according to claim 1, A canister bracket for mounting an exhaust canister is further joined to the rear surface of the rear floor panel. At least one of the one or more component brackets overlaps with the canister bracket in a top view, and the canister bracket, the rear floor panel, and the component bracket are joined to each other in an overlapping state at the overlapping portion. A vehicle rear structure comprising:

4. A vehicle rear structure according to any one of claims 1 to 3, The component bracket is provided on each end of the rear floor panel in a vehicle width direction, and two of the component brackets are provided in total. One of the component brackets is joined to each of the pair of rear side members. A vehicle rear structure comprising:

5. A vehicle rear structure according to any one of claims 1 to 3, A vehicle width direction dimension of the component bracket is larger than a vehicle width direction dimension of the inner region, a right end portion of the component bracket is joined to the right rear side member, and a left end portion of the component bracket is joined to the left rear side member together with the rear floor panel. A vehicle rear structure comprising:

6. A vehicle rear structure according to any one of claims 1 to 5, A vehicle rear structure, characterized in that at least one of the front and rear portions of the component bracket is joined to at least one of the second cross member and the first cross member, together with the rear floor panel.

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