Vehicle body rear structure

Abstract

Provided is a frame structure for a vehicle, the frame structure being capable of achieving light weight and improving the degree of freedom of vehicle body design. The vehicle body rear structure (1) is integrally provided with a rear wheel cover part (10) and a rear frame connecting part (26) through die-casting forming, the rear wheel cover part (10) is provided with a bulging part (11) which bulges inwards in the vehicle width direction and covers a rear wheel (3), and at least a part of the rear frame connecting part (26) is arranged in front of the rear end part of the bulging part (11).

Description

Technical Field

[0001] This invention relates to the rear structure of a vehicle body. Background Technology

[0002] In recent years, research and development related to lightweighting, which contributes to energy efficiency, has been underway to ensure that more people can rely on reliable energy and to ensure the pursuit of sustainable and advanced energy. On the other hand, Patent Document 1 discloses a die-cast vehicle rear floor structure that integrates a pair of left and right rear wheel arches, a pair of left and right longitudinal beams arranged along the lower end of the rear wheel arches, a connecting beam connecting the left and right longitudinal beams, and a pair of front and rear crossbeams.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Chinese Patent Application Publication No. 117360634 Summary of the Invention

[0006] In this configuration, the rear frame connects to the die-cast rear floor structure behind the rear wheelhouse. As a result, the overall length of the vehicle (rear overhang) increases, leading to increased weight and reduced freedom in vehicle design.

[0007] The present invention was made in view of the above points, with the object being to provide a vehicle frame structure that enables lightweighting and increases the freedom of vehicle body design, thereby contributing to energy efficiency.

[0008] To address the aforementioned issues, the rear vehicle body structure of the present invention is integrally formed by die casting, comprising a rear wheel arch portion and a rear frame connection portion for connecting to a rear frame. The rear vehicle body structure is characterized in that the rear wheel arch portion has a bulge portion that bulges inward in the vehicle width direction to cover the rear wheel, and at least a portion of the rear frame connection portion is disposed in front of the bulge portion compared to the rear end of the bulge portion.

[0009] Invention Effects

[0010] According to the present invention, it is possible to achieve lightweighting of the rear structure of the vehicle body and increase the freedom of vehicle body design, thereby contributing to energy efficiency. Attached Figure Description

[0011] Figure 1 This is a schematic diagram illustrating the rear structure of the vehicle body according to an embodiment of the present invention, and is a perspective view viewed from the upper front.

[0012] Figure 2This is a schematic diagram illustrating the rear structure of a vehicle body according to an embodiment of the present invention, and is a perspective view viewed from an oblique, upper rear view.

[0013] Figure 3 This is a side view schematically illustrating the rear structure of a vehicle body according to an embodiment of the present invention.

[0014] Figure 4 This is a top view schematically illustrating the rear structure of a vehicle body according to an embodiment of the present invention.

[0015] Figure 5 This is a bottom view schematically illustrating the rear structure of a vehicle body according to an embodiment of the present invention.

[0016] Figure 6 It is a three-dimensional diagram showing the rear frame connection and the opposite ribs.

[0017] Figure 7 yes Figure 5 Enlarged view of Part VII.

[0018] Figure 8 yes Figure 4 Sectional view along line VIII-VIII.

[0019] Figure 9 yes Figure 4 A cross-sectional view along line IX-IX.

[0020] Figure 10 This is a schematic diagram illustrating the rear structure of the vehicle body according to an embodiment of the present invention, and is a bottom view showing the state in which the drive unit is installed.

[0021] Explanation of reference numerals in the attached figures

[0022] 1. Rear structure of the vehicle body

[0023] 2 Foundry Department

[0024] 3 rear wheels

[0025] 4 drive units

[0026] 10 Rear wheel arch

[0027] 11. Bulging section (rear wheel arch body)

[0028] 20 rear bottom panel

[0029] 21. Upper wall section (rear bottom panel main body section)

[0030] 22 Front wall section (rear bottom panel main body section)

[0031] 23. First lower wall section (rear bottom plate panel main body section)

[0032] 24. Rear wall section (rear bottom plate panel main body)

[0033] 25 Second lower wall section (rear bottom panel main body section)

[0034] 25a Notch

[0035] 26 Rear frame connection

[0036] 26a Relative wall portion

[0037] 26b outer wall portion

[0038] 26c Inner Wall

[0039] 26d lower wall

[0040] 27 Drive Unit Mounting Section

[0041] 31 left and right ribs

[0042] 32 front and rear ribs

[0043] 32a, 32c Front and rear ribs (load transfer ribs, upper side ribs)

[0044] 33 ring ribs

[0045] 34 relative ribs

[0046] 36 ribs

[0047] 37 Anterior and posterior ribs

[0048] 37a, 37b, 37c Front and rear ribs (load transfer ribs, lower side ribs)

[0049] 38 ring ribs

[0050] 39 Reinforcing Ribs

[0051] 40 rear frame

[0052] 41 Front end

[0053] X-clamp Detailed Implementation

[0054] Next, embodiments of the present invention will be described in detail with appropriate reference to the accompanying drawings. In the drawings, "front and rear" refers to the front-to-back direction (front-to-back direction of the vehicle body) in the direction of vehicle travel, and "left and right" refers to the left and right direction (vehicle width direction) as viewed from the driver's seat.

[0055] like Figure 1 as well as Figure 2As shown, the rear body structure 1 of the embodiment of the present invention is constituted by a die-casting casting formed by at least a portion of it using aluminum as the material (aluminum die casting). The rear body structure 1, as a die-casting casting, i.e., the casting part 2, integrally includes a pair of left and right rear wheel arch portions 10 and a rear floor panel portion 20 connecting the pair of left and right rear wheel arch portions 10. Furthermore, the rear body structure 1, as a component different from the casting part 2, has a pair of left and right rear frames 40 (see reference 2). Figure 3 ).

[0056] <Rear wheel arch>

[0057] The rear wheel arch 10 integrally has a bulge 11, a flange 12 and multiple ribs 13.

[0058] The bulge 11 is a rear wheel arch body that bulges inward in the vehicle width direction. The rear wheel 3 of the vehicle is housed on the outer side of the bulge 11 in the vehicle width direction (see reference). Figure 3 The upper part of ).

[0059] The flange portion 12 extends outward from the outer end of the bulge portion 11 in the vehicle width direction.

[0060] Rib 13 extends outward from the bulge 11 in the vehicle width direction.

[0061] <Rear bottom panel>

[0062] The rear floor panel 20 is a plate-shaped portion that connects the protruding portions 11 of the left and right rear wheel arches 10 to each other. The rear floor panel 20, as the main body of the rear floor panel, has an upper wall portion 21, a front wall portion 22, a first lower wall portion 23, a rear wall portion 24, and a second lower wall portion 25.

[0063] Upper Wall Section

[0064] The upper wall portion 21 extends in the front-rear direction and the vehicle width direction.

[0065] Front Wall Section

[0066] The front wall portion 22 extends downward from the front end of the upper wall portion 21.

[0067] First Outer Wall Section

[0068] The first lower wall portion 23 extends forward from the lower end of the front wall portion 22. The middle portion of the first lower wall portion 23 in the vehicle width direction forms a flange portion relative to the front wall portion 22. The end portion of the first lower wall portion 23 in the vehicle width direction extends towards the front side of the rear wheel arch portion 10.

[0069] The Rear Wall Section

[0070] The rear wall portion 24 extends downward from the rear end of the upper wall portion 21.

[0071] The Second Lower Wall Section

[0072] The second lower wall portion 25 extends rearward from the lower end of the rear wall portion 24. The width-direction end of the second lower wall portion 25 extends towards the rear side of the rear wheel arch portion 10. The rear end of the middle portion in the width-direction of the second lower wall portion 25 is located in front of the rear end of the rear wheel arch portion 10 (bulge 11), forming a notch portion 25a. This notch portion 25a ensures space for component placement. Furthermore, the surface finish of the second lower wall portion 25 is improved by machining after casting.

[0073] <Rear frame connection>

[0074] like Figure 4 as well as Figure 6 As shown, the rear floor panel 20 has a pair of left and right rear frame connecting parts 26 for connecting to the rear frame 40.

[0075] The rear frame connecting portion 26 is formed in the area of ​​the rear wall portion 24 and the second lower wall portion 25, and is a recessed portion that is recessed forward. The rear frame connecting portion 26 has a counter wall portion 26a, an outer wall portion 26b, an inner wall portion 26c, and a lower wall portion 26d.

[0076] The opposite wall portion 26a is part of the rear wall portion 24 of the rear floor panel main body, and extends in the vehicle width direction and the vertical direction.

[0077] The outer wall portion 26b is part of the rear wall portion 24 of the rear floor panel main body, and extends rearward from the outer end of the opposite wall portion 26a in the vehicle width direction. The rear frame 40 is connected to the outer wall portion 26b by bolts or the like.

[0078] In this embodiment, a protrusion (base portion) 26b1 protruding inward in the vehicle width direction is formed on the outer wall portion 26b. The front end of the rear frame 40 is fixed to the protrusion 26b1 by a bolt that passes through a hole formed on the front end face of the protrusion 26b1 in the vehicle width direction. In addition, the head of the bolt is received in the space on the outer side of the protrusion 26b1 in the vehicle width direction.

[0079] The inner wall portion 26c is part of the rear wall portion 24 of the rear floor panel main body, and extends rearward from the inner end of the opposite wall portion 26a in the vehicle width direction. The inner wall portion 26c is inclined inward in the vehicle width direction as it moves rearward. The rear frame 40 is connected to the inner wall portion 26c by bolts or the like.

[0080] In this embodiment, a rearwardly protruding convex portion (base portion) 26c1 is formed in the inner wall portion 26c. The front end of the rear frame 40 (more specifically, the flange portion (not shown) mounted on the front end of the rear frame 40) is fixed to the convex portion 26c1 by bolts that pass through a hole formed in the front end face of the rear side of the convex portion 26c1.

[0081] The lower wall portion 26d is part of the second lower wall portion 25 of the rear bottom panel main body, and extends rearward from the lower end of the opposing wall portion 26a. The lower wall portion 26d connects the lower ends of the outer wall portion 26b and the inner wall portion 26c to each other.

[0082] The rear frame connection portion 26 is located at the rear of the rear floor panel main body, in front of the notch 25a, which is the rear end portion of the rear floor panel main body. Furthermore, the rear frame connection portion 26 is positioned inside the vehicle width direction of the inner end of the bulge 11, and at least a portion of this rear frame connection portion 26 is positioned in front of the rear end of the bulge 11. Therefore, the rear body structure 1 can shorten the rear overhang of the vehicle body, enabling weight reduction and increased freedom in vehicle body design.

[0083] The rear frame connection 26 and the front end 41 of the rear frame 40 are located in front of the rear end of the drive unit 4. The rear part of the drive unit 4 is disposed between the left and right pairs of rear frames 40.

[0084] <Rib Structure>

[0085] like Figure 4 as well as Figure 5 As shown, in order to improve the rigidity of the rear floor panel body, transfer loads, and absorb collision energy, multiple ribs are formed in the rear floor panel body of the rear floor panel section 20.

[0086] <Rib structure on the upper surface>

[0087] like Figure 4 As shown, the rear floor panel 20 has multiple left and right ribs 31, multiple front and rear ribs 32, multiple annular ribs 33, and a pair of opposing ribs 34, which are erected on the upper surface side (interior side). These ribs are capable of transmitting loads and absorbing collision energy along the direction of the rib. In the following description, the front and rear ribs 32a, 32c, 37a, 37b, and 37c (refer to) will be described as inclined towards the inside of the vehicle width direction as they move forward. Figure 5 This is called a load transfer rib.

[0088] Left and right ribs

[0089] The left and right ribs 31 are erected vertically upward from the upper wall portion 21 of the rear floor panel main body and extend in the vehicle width direction. In this embodiment, the two ends of the left and right ribs 31 in the vehicle width direction are respectively connected to the bulge portion 11 of the rear wheel arch portion 10.

[0090] Front and back ribs

[0091] The front and rear ribs 32 are erected vertically upward from the upper wall portion 21, the front wall portion 22, and the first lower wall portion 23 of the rear floor panel main body (erected from the front wall portion 22 forward), and extend in the front-rear direction. The front and rear ribs 32 located on the outer side in the vehicle width direction among the plurality of front and rear ribs 32 are inclined in such a way that they tend to be outward in the vehicle width direction as they move forward.

[0092] Load transfer ribs / upper side ribs

[0093] Among the multiple front and rear ribs 32, the left and right pairs of front and rear ribs 32a on the inner side in the vehicle width direction are load-transfer ribs (upper ribs) that are inclined inward in the vehicle width direction as they move forward. The rear ends of the front and rear ribs 32a are located in front of the rear frame connection portion 26. In this embodiment, the rear ends of the front and rear ribs 32a are connected to the opposing wall portion 26a of the rear frame connection portion 26. The front portions of the front and rear ribs 32a extend in the front-rear direction.

[0094] Compared to the pair of front and rear ribs 32a on the left and right, the pair of front and rear ribs 32c on the left and right, located on the outer side in the vehicle width direction, are load transfer ribs (upper ribs) that tend to move inward in the vehicle width direction as they move forward.

[0095] The rear ends of the front and rear ribs 32c are located in front of the rear frame connection portion 26. In this embodiment, the rear ends of the front and rear ribs 32c are connected to the opposing wall portion 26a of the rear frame connection portion 26. The rear portions of the front and rear ribs 32a extend in the front-rear direction.

[0096] The angle θ of the inclined portions of the front and rear ribs 32a and 32c relative to the front and rear direction is less than 30 degrees (e.g., 30 degrees).

[0097] Ring rib

[0098] The annular rib 33, when viewed from above, is cylindrical and is located in front of the rear frame connection portion 26. In this embodiment, the annular rib 33 connects the front and rear ribs 32a, which serve as load transfer ribs, the front and rear ribs 32 adjacent to the front and rear ribs 32a, and the left and right ribs 31. In other words, the front and rear ribs 32a, the front and rear ribs 32 adjacent to the front and rear ribs 32a, and the left and right ribs 31 are formed in a radially extending manner from the annular rib 33. That is, the front and rear ribs 32a, the front and rear ribs 32 adjacent to the front and rear ribs 32a, and the left and right ribs 31 are disconnected at the annular rib 33 either front-to-back or left-to-right.

[0099] Opposite Ribs

[0100] The opposing rib 34 extends rearward from the opposing wall portion 26a of the rear frame connection portion 26. In this embodiment, the opposing rib 34 has a grid shape (e.g., honeycomb shape) when viewed from the rear. The rear end of the opposing rib 34 is separated from and opposite the front end of the rear frame 40.

[0101] <Rib structure on the lower surface>

[0102] like Figure 5 As shown, the rear floor panel 20 has multiple left and right ribs 36, multiple front and rear ribs 37, multiple annular ribs 38, and reinforcing ribs 39 as ribs that are erected on the lower surface side (outer side of the vehicle body).

[0103] Left and right ribs

[0104] The left and right ribs 36 are positioned corresponding to the left and right ribs 31 on the upper side, and are vertically arranged downward from the upper wall portion 21 of the rear floor panel body and extend in the vehicle width direction.

[0105] Front and back ribs

[0106] The front and rear ribs 37 are erected vertically downward from the upper wall portion 21, the front wall portion 22, and the first lower wall portion 23 of the rear floor panel main body at positions corresponding to the upper front and rear ribs 32 and at other positions, and extend in the front-rear direction. The front and rear ribs 37 located on the outer side in the vehicle width direction among the plurality of front and rear ribs 37 are inclined in such a way that they tend to be outward in the vehicle width direction as they move forward.

[0107] Load transfer ribs / lower side ribs

[0108] Among the plurality of front and rear ribs 37, the left and right pairs of front and rear ribs 37a on the inner side in the vehicle width direction are load-transfer ribs (lower ribs) that are inclined inward in the vehicle width direction as they move forward, corresponding to the upper front and rear ribs 32a. The rear ends of the front and rear ribs 37a are located in front of the rear frame connection portion 26. In this embodiment, the rear ends of the front and rear ribs 37a are connected to the opposing wall portion 26a of the rear frame connection portion 26. The front ends of the front and rear ribs 32a extend in the front-rear direction.

[0109] The front and rear ribs 37b, adjacent to the front and rear ribs 37a, are load-transfer ribs (lower ribs) that are inclined inward in the vehicle width direction as they move forward. The rear ends of the front and rear ribs 37b are located in front of the rear frame connection 26. In this embodiment, the rear ends of the front and rear ribs 37b are connected to the annular rib 38.

[0110] Compared to the pair of left and right front and rear ribs 37b, the pair of left and right front and rear ribs 37b located on the outer side in the vehicle width direction are load-transfer ribs (lower ribs) that tend to be inclined towards the inner side in the vehicle width direction as they move forward. The rear ends of the front and rear ribs 37c are located in front of the rear frame connection portion 26. In this embodiment, the rear ends of the front and rear ribs 37c are connected to the opposing wall portion 26a of the rear frame connection portion 26. The rear portions of the front and rear ribs 37b are provided in the front-rear direction.

[0111] The angle θ of the inclined portions of the front and rear ribs 37a and 37b relative to the front and rear direction is less than 30 degrees (for example, the front and rear ribs 37a and 37c are 30 degrees, and the front and rear ribs 37b are 15 degrees).

[0112] Ring rib

[0113] like Figure 7 As shown, the annular rib 38 is cylindrical in shape when viewed from above and is located in front of the rear frame connection portion 26. In this embodiment, the annular rib 38 connects the front and rear ribs 37a and 37b, which serve as load transfer ribs, the front and rear ribs 37 adjacent to the front and rear ribs 37b, and the left and right ribs 36. In other words, the front and rear ribs 37a and 37b, the front and rear ribs 37 adjacent to the front and rear ribs 37b, and the left and right ribs 36 are formed in a radial manner extending from the annular rib 38. That is, the front and rear ribs 37a, the front and rear ribs 37 adjacent to the front and rear ribs 37b, and the left and right ribs 36 are disconnected at the annular rib 38 at either the front and rear or left and right sides.

[0114] Strengthening Ribs

[0115] like Figure 5 As shown, the reinforcing rib 39 is a component that improves the rigidity of the rear bottom panel 20. It extends downward from the upper wall portion 21 in the area surrounded by a pair of left and right ribs 36 and a pair of front and rear ribs 37a. When viewed from below, the reinforcing rib 39 has a grid shape (e.g., honeycomb shape). In this embodiment, the reinforcing rib 39 is connected to the pair of left and right ribs 36 and the pair of front and rear ribs 37a. Furthermore, the reinforcing rib 39 is not limited to a grid shape; it can also be a rib that runs only along the front-rear direction, a rib that runs only along the left-right direction, or a rib that is irregularly arranged and exists in a mixture of these directions.

[0116] <Load transfer ribs at the top and bottom>

[0117] like Figure 4 as well as Figure 5 As shown, the lower front and rear ribs 37a, 37b, and 37c are more numerous than the upper front and rear ribs 32a and 32c, which are load transfer ribs that tend to move inward in the vehicle width direction as they move forward.

[0118] like Figure 8As shown, among the front and rear ribs 32a and 37a, which are load-transfer ribs that tend to move inward in the vehicle width direction as they move forward, the vertical installation height H2 of the lower front and rear rib 37a is greater than the vertical installation height H1 of the upper front and rear rib 32a. Furthermore, this height relationship can also be applied to other front and rear ribs 32 and 37, left and right ribs 31 and 36, and annular ribs 33 and 38.

[0119] The rear structure 1 of the vehicle body can suppress the accumulation of electrophoretic paint and prevent the deterioration of the spraying quality by making the upper front and rear ribs 32a lower than the lower front and rear ribs 37a and making the upper front and rear ribs 32a less than the lower front and rear ribs 37a and 37b.

[0120] Furthermore, as described above, the front and rear ribs 32a, 32c, 37a, 37b, and 37c, which serve as load transfer ribs, only need to be able to transfer the rear collision load input to the rear frame connection portion 26 forward. That is, the rear ends of the front and rear ribs 32a, 32c, 37a, 37b, and 37c can be connected to the rear frame connection portion 26 (opposite wall portion 26a), or they can be located in front of the rear frame connection portion 26 (opposite wall portion 26a) and separate from it.

[0121] <Rear frame>

[0122] like Figure 3 as well as Figure 4 As shown, the rear frame 40 is a cylindrical metal component extending in the front-to-back direction. When viewed from the front, the rear frame 40 has a closed cross-sectional shape (octagonal in this embodiment). The rear frame 40 extends rearward from the rear floor panel 20. When viewed from above, the front portion of the rear frame 40 overlaps with the rear floor panel 20, and the rear portion of the rear frame 40 protrudes rearward from the rear floor panel 20 when viewed from above. The front end 41 of the rear frame 40 is connected to the rear frame connecting portion 26. Bumpers (not shown) are mounted on the rear ends of the pair of left and right rear frames 40.

[0123] like Figure 9 As shown, the rear frame 40 and the rear frame connecting part 26 on one side (e.g., the left side) in the vehicle width direction are located at a distance W2 in the vehicle width direction between them and the end of the vehicle body on the other side (e.g., the right side) in the vehicle width direction, which is within 70% (and greater than 50%) of the overall width W1 of the vehicle body.

[0124] <Rear frame mounting structure>

[0125] like Figure 4 as well as Figure 6As shown, the front end 41 of the rear frame 40 is connected to the rear frame connecting portion 26 in a state where it is separated from and opposite the opposing rib 34. That is, the outer wall of the front end 41 of the rear frame 40 is bolted to the outer wall 26b of the rear frame connecting portion 26. Here, the protrusion 26b1 of the outer wall 26b is integrated with the lower part of the bulge 11 and can be approached from the outside of the bulge 11 in the vehicle width direction. Therefore, bolt fastening can be performed from the outside of the bulge 11 in the vehicle width direction of the rear wheel arch portion 10 using a clamp X (see reference). Figure 9 ).

[0126] like Figure 3 As shown, the rear frame connection portion 26, that is, the front end portion 41 of the rear frame 40 connected to the rear frame connection portion 26, is positioned to overlap with the rear wheel 3 when viewed from the side. The front end portion 41 of the rear frame 40 may also be positioned to overlap with the rim 3a of the rear wheel 3 when viewed from the side, or it may be positioned to overlap with the tire 3b of the rear wheel 3. In this embodiment, the portion of the outer wall portion 26b for connecting the rear frame 40 is positioned to overlap with the tire 3b of the rear wheel 3 when viewed from the side, and can be accessed from the outside of the bulge 11 of the rear wheel cover portion 10 (the space for accommodating the rear wheel 3 formed on the outside of the bulge 11 in the vehicle width direction).

[0127] like Figure 4 as well as Figure 6 As shown, the inner wall of the front end 41 of the rear frame 40 is bolted to the inner wall 26c of the rear frame connecting portion 26 via a flange member (not shown). The bolts can be tightened from behind the inner wall 26c.

[0128] <Mounting Structure of the Drive Unit>

[0129] like Figure 10 As shown, the drive unit 4 has a power source (e.g., a motor) 4a for rotating a pair of left and right rear wheels 3, and a pair of transmission parts (e.g., shafts) 4b for transmitting the rotational force of the power source 4a to the rear wheels 3. More specifically, the power source 4a of the drive unit 4 is located below the upper wall portion 21, in the area surrounded by the upper wall portion 21, the front wall portion 22, and the rear wall portion 24, and is mounted to multiple drive unit mounting portions 27 by bolts or the like. The multiple drive unit mounting portions 27 are arranged to surround the reinforcing ribs 39, which will be described later.

[0130] The drive unit mounting portion 27 is provided on the lower wall portion 26d of each of the pair of left and right rear frame connecting portions 26. The drive unit mounting portion 27 is provided on the rear frame connecting portion 26, which is strengthened by connecting the rear frame 40, so that the drive unit 4 can be properly held.

[0131] <Load transfer during a rear collision>

[0132] In the event of a rear-end collision, the rear-end collision load is transferred from the pair of left and right rear frames 40 to the rear frame connection 26 of the rear vehicle body structure 1. The rear-end collision load transferred to the rear frame connection 26 is distributed in the vehicle width direction via the upper and lower front and rear ribs 32 and 37, and is simultaneously transferred forward. Therefore, the rear vehicle body structure 1 can properly transfer the rear-end collision load and can properly absorb the collision energy in the entire middle part of the vehicle width direction, including the rear floor panel.

[0133] Here, in the event of a rear-end collision, the rear frame 40 deforms in such a way that its rear end is lifted. That is, the upper front and rear ribs 32 deform in the compression direction, and the lower front and rear ribs 37 deform in the tension direction. In the rear structure 1 of the vehicle body, the lower front and rear ribs 37 that deform in the tension direction are higher and more numerous than the upper front and rear ribs 32 that deform in the compression direction, so that the rear-end collision load can be properly transferred through the less deformable lower front and rear ribs 37.

[0134] In addition, in the rear structure 1 of the vehicle body, the front and rear ribs 32a, 32c, 37a, 37b, and 37c, which serve as load transfer ribs, are set at an angle θ relative to the front and rear directions of less than 30 degrees. Therefore, the deformation of the ribs can be suppressed and the rear collision load can be properly transferred.

[0135] In addition, the rear structure 1 of the vehicle body improves the rigidity of the central part in the vehicle width direction by reinforcing ribs 39, thus suppressing the deformation of the main body of the rear floor panel caused by the rear collision load and more properly transmitting the rear collision load.

[0136] In addition, the rear structure 1 of the vehicle body disperses the rear collision load to multiple front and rear ribs 32 and 37 through the annular ribs 33 and 38, thus enabling more appropriate transfer of the rear collision load.

[0137] The rear structure 1 of the vehicle body of the present invention is integrally formed by die casting, having a rear wheel cover 10 and a rear frame connection 26 for connecting to the rear frame 40. The rear wheel cover 10 has a bulge 11 that bulges inward in the vehicle width direction to cover the rear wheel 3. At least a portion of the rear frame connection 26 is disposed in front of the rear end of the bulge 11.

[0138] Therefore, the rear structure 1 can shorten the rear overhang of the vehicle body by aligning the rear frame 40 at the front. In other words, the rear structure 1 enables weight reduction and increases the freedom of vehicle body design.

[0139] In the rear structure 1 of the vehicle body, the rear frame connection 26 is located at a position within 70% of the overall width of the vehicle body, from the end of the vehicle body located on the opposite side of the rear frame connection 26 in the vehicle width direction.

[0140] Therefore, even in the event of an offset rear-end collision, the rear structure 1 can bear the load through both sides of the left and right rear frames 40. In other words, the rear structure 1 can reduce the input of the rear-end collision load to the left and right rear frames 40 during an offset rear-end collision, and can achieve weight reduction including the rear frames 40.

[0141] In the rear structure 1 of the vehicle body, the rear floor panel 20 has opposing ribs 34 that extend in the front-rear direction and are located opposite to the front end 41 of the rear frame 40.

[0142] Therefore, the rear structure 1 can properly bear and transmit the rear collision load from the rear frame 40. In addition, the rear structure 1 can adjust the length of the relative rib 34 according to the position of the front end 41 of the rear frame 40, which can improve the freedom of the installation position of the rear frame 40.

[0143] The rear structure 1 of the vehicle body is integrally formed by die casting, having a pair of left and right rear wheel arch portions 10 and a rear floor panel portion 20 connecting the pair of left and right rear wheel arch portions 10, and the rear frame connecting portion 26 is provided on the rear floor panel portion 20.

[0144] Therefore, the rear structure 1 can increase the freedom of the mounting position of the rear frame connection 26. In addition, the rear structure 1 can distribute the rear collision load from the rear frame 40 to the left and right rear wheel arches 10, thus enabling the rear frame 40 to be miniaturized and the rear overhang to be shortened.

[0145] In the rear structure 1 of the vehicle body, between the pair of left and right rear wheel arch portions 10, the rear end of the rear floor panel portion 20 is located in front of the rear end of the bulge portion 11 in the pair of left and right rear wheel arch portions 10, and the rear frame connecting portion 26 is located in front of the rear end portion of the rear floor panel portion 20.

[0146] Therefore, even with a shortened rear overhang, the rear structure 1 can still ensure space for component placement and maintain freedom in vehicle design. Furthermore, by integrating the left and right rear wheel arches 10 and the rear floor panel 20 into a single cast part 2, the rear structure 1 achieves miniaturization and weight reduction of the rear floor structure.

[0147] In the rear structure 1 of the vehicle body, the front end 41 of the rear frame 40 and the rear end of the drive unit 4 disposed between the left and right pairs of rear frames 40 are located in front.

[0148] Therefore, the rear structure 1 of the vehicle body can ensure the placement space of the drive unit 4 while shortening the rear overhang. In addition, the rear structure 1 of the vehicle body can firmly hold the drive unit 4.

[0149] In the rear structure 1 of the vehicle body, the rear frame connecting part 26 is located on the inner side in the vehicle width direction compared to the inner end of the bulge part 11.

[0150] Therefore, the rear structure 1 of the vehicle body can position the rear frame 40 further forward.

[0151] In the rear structure 1 of the vehicle body, the rear frame connecting part 26 is configured such that the rear frame 40 can be connected from the outside of the rear wheel arch part 10.

[0152] Therefore, the rear structure 1 of the vehicle body can achieve the frontal configuration of the rear frame 40 while preventing a reduction in installation operability.

[0153] In the rear structure 1 of the vehicle body, the rear frame connecting part 26 is positioned at a position that overlaps with the rear wheel 3 when viewed from the side.

[0154] Therefore, the rear structure 1 can shorten the rear overhang of the vehicle body by realizing the frontal configuration of the rear frame 40.

[0155] The above describes the embodiments of the present invention, but the present invention is not limited to the above embodiments and can be appropriately modified without departing from the spirit of the present invention.

Claims

1. A vehicle body rear structure integrally having a rear wheel house portion and a rear frame connecting portion for connecting a rear frame by die casting, the vehicle body rear structure characterized by, the rear wheel house portion having a bulging portion bulging toward an inner side in a vehicle width direction to cover a rear wheel, at least a part of the rear frame connecting portion being disposed forward of a rear end portion of the bulging portion.

2. The vehicle body rear structure according to claim 1, characterized in that, the rear frame connecting portion is provided at a position within 70% of a total width of the vehicle body in the vehicle width direction from a vehicle body end portion on an opposite side of the rear frame connecting portion in the vehicle width direction.

3. The vehicle body rear structure according to claim 1, characterized in that, integrally having by die casting: a pair of left and right rear wheel house portions; and a rear floor panel portion connecting the pair of left and right rear wheel house portions, the rear frame connecting portion is provided to the rear floor panel portion.

4. The vehicle body rear structure according to claim 3, characterized in that, the rear floor panel portion has an opposite rib provided extending in a front-rear direction, the opposite rib is provided at a position opposite to a front end portion of the rear frame.

5. The vehicle body rear structure according to claim 3, characterized in that, a rear end portion of the rear floor panel portion is located forward of rear end portions of the bulging portions in the pair of left and right rear wheel house portions between the pair of left and right rear wheel house portions, the rear frame connecting portion is provided forward of the rear end portion of the rear floor panel portion.

6. The vehicle body rear structure according to claim 1, characterized in that, a front end portion of the rear frame is located forward of a rear end portion of a drive unit disposed between the pair of left and right rear frames.

7. The vehicle body rear structure according to claim 1, characterized in that, the rear frame connecting portion is disposed inward in the vehicle width direction from an inner end portion of the bulging portion in the vehicle width direction.

8. The vehicle body rear structure according to claim 1, characterized in that, the rear frame connecting portion is configured in a manner capable of connecting the rear frame from an outer side of the rear wheel house portion in a vehicle width direction.

9. The vehicle body rear structure according to claim 1, characterized in that, the rear frame connecting portion is disposed at a position overlapping the rear wheel in a side view.

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