Rear body structure

Abstract

To provide a vehicle frame structure that can achieve weight reduction and improved freedom of vehicle body design. [Solution] The rear body structure (1) comprises a rear wheel house section (10) and a rear frame connecting section (26) to which a rear frame (40) is connected, which are integrally formed by die-cast molding, the rear wheel house section (10) having a bulge section (11) that bulges inward in the vehicle width direction to cover the rear wheel (3), and at least a portion of the rear frame connecting section (26) is positioned forward of the rear end of the bulge section (11).

Description

Technical Field

[0001] The present invention relates to the structure of the rear part of a vehicle body.

Background Art

[0002] In recent years, in order to enable more people to have access to affordable, reliable, sustainable, and advanced energy, research and development related to weight reduction that contributes to energy efficiency has been carried out. On the other hand, Patent Document 1 discloses a die-cast rear floor body structure in which a pair of left and right rear wheel covers, a pair of left and right longitudinal beams provided along the lower end portions of the rear wheel covers, a connecting beam connecting the pair of left and right longitudinal beams, and a pair of front and rear cross beams are integrated.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In such a structure, the rear frame is connected to the die-cast rear floor body structure behind the rear wheel cover (rear wheelhouse). Therefore, the overall length of the vehicle body (rear overhang) becomes long, resulting in an increase in weight and a decrease in the degree of freedom of vehicle body design.

[0005] In view of the above points, the present invention has been made, and an object thereof is to provide a vehicle frame structure that can achieve weight reduction and an improvement in the degree of freedom of vehicle body design, and thus contribute to energy efficiency.

Means for Solving the Problems

[0006] To solve the above-described problems, the rear part structure of the vehicle body of the present invention is A pair (left and right)The rear wheel well area, A rear floor panel section connecting the left and right pairs of aforementioned rear wheel well sections, A rear body structure comprising a rear frame connecting portion to which the rear frame is connected, integrally formed by die-cast molding, wherein the rear wheel house portion includes a bulge portion that bulges inward in the vehicle width direction and covers the rear wheel, The rear frame connecting portion is provided on the rear floor panel portion. At least a portion of the rear frame connecting portion is positioned forward of the rear end of the bulging portion. [Effects of the Invention]

[0007] According to the present invention, it is possible to reduce the weight of the rear structure of the vehicle body and improve the degree of freedom in vehicle body design, which in turn can contribute to energy efficiency. [Brief explanation of the drawing]

[0008] [Figure 1] This figure schematically shows the rear structure of a vehicle body according to an embodiment of the present invention, and is a perspective view taken from diagonally above and in front. [Figure 2] This figure schematically shows the rear body structure of a vehicle according to an embodiment of the present invention, and is a perspective view taken from diagonally above and behind. [Figure 3] This is a schematic side view showing the rear structure of a vehicle body according to an embodiment of the present invention. [Figure 4] This is a schematic plan view showing the rear body structure of a vehicle according to an embodiment of the present invention. [Figure 5] This is a schematic bottom view showing the rear body structure of a vehicle according to an embodiment of the present invention. [Figure 6] This is a schematic perspective view showing the rear frame connection and opposing ribs. [Figure 7] This is an enlarged view of section VII in Figure 5. [Figure 8] This is a cross-sectional view taken along line VIII-VIII in Figure 4. [Figure 9] This is a cross-sectional view taken along the line IX-IX in Figure 4. [Figure 10] This figure schematically shows the rear body structure of a vehicle according to an embodiment of the present invention, and is a bottom view showing the state in which the drive unit is attached. [Modes for carrying out the invention]

[0009] Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. In the reference drawings, "front and rear" indicates the front-rear direction (vehicle body front-rear direction) in the traveling direction of the vehicle, and "left and right" indicates the left-right direction (vehicle width direction) as viewed from the driver's seat, respectively.

[0010] As shown in FIGS. 1 and 2, the vehicle body rear structure 1 according to an embodiment of the present invention is constituted by a die-cast casting formed at least partially by a die-casting method (aluminum die-casting method) using aluminum as a material. The vehicle body rear structure 1 includes, as a die-cast part 2 that is a die-cast casting, a pair of left and right rear wheel house parts 10 and a rear floor panel part 20 that connects the pair of left and right rear wheel house parts 10 integrally. Further, the vehicle body rear structure 1 includes a pair of left and right rear frames 40 (see FIG. 3) as separate members from the die-cast part 2.

[0011] <Rear wheel house part> The rear wheel house part 10 integrally includes a bulging part 11, a flange part 12, and a plurality of ribs 13.

[0012] The bulging part 11 is a rear wheel house main body part having a shape that bulges inward in the vehicle width direction. The upper part of the rear wheel 3 (see FIG. 3) of the vehicle is accommodated outside the bulging part 11 in the vehicle width direction.

[0013] The flange part 12 extends outward from the outer end of the bulging part 11 in the vehicle width direction.

[0014] The rib 13 extends outward from the bulging part 11 in the vehicle width direction.

[0015] <Rear floor panel part> The rear floor panel portion 20 is a plate-like portion provided so as to connect the bulging portions 11 of the pair of left and right rear wheel house portions 10 to each other. The rear floor panel portion 20 includes, as a rear floor panel main body portion, 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.

[0016] ≪Upper wall portion≫ The upper wall portion 21 extends in the front-rear direction and the vehicle width direction.

[0017] ≪Front wall portion≫ The front wall portion 22 extends downward from the front end portion of the upper wall portion 21.

[0018] ≪First outer wall portion≫ The first lower wall portion 23 extends forward from the lower end portion of the front wall portion 22. The intermediate portion in the vehicle width direction of the first lower wall portion 23 constitutes a flange portion with respect to the front wall portion 22. The end portions in the vehicle width direction of the first lower wall portion 23 extend to the front side of the rear wheel house portion 10.

[0019] ≪Rear wall portion≫ The rear wall portion 24 extends downward from the rear end portion of the upper wall portion 21.

[0020] ≪Second lower wall portion≫ The second lower wall portion 25 extends rearward from the lower end portion of the rear wall portion 24. The end portions in the vehicle width direction of the second lower wall portion 25 extend to the rear side of the rear wheel house portion 10. The rear end portion of the intermediate portion in the vehicle width direction of the second lower wall portion 25 is located forward of the rear end portion of the rear wheel house portion 10 (bulging portion 11) and constitutes a notch portion 25a. Such a notch portion 25a is for securing a component arrangement space. Also, the surface accuracy of the second lower wall portion 25 is improved by performing cutting processing after casting.

[0021] <Rear frame connection portion> As shown in FIGS. 4 and 6, the rear floor panel portion 20 includes a pair of left and right rear frame connection portions 26 as portions to which the rear frame 40 is connected.

[0022] The rear frame connecting portion 26 is formed across the rear wall portion 24 and the second lower wall portion 25, and is a recess that curves forward. The rear frame connecting portion 26 comprises an opposing wall portion 26a, an outer wall portion 26b, an inner wall portion 26c, and a lower wall portion 26d.

[0023] The opposing 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.

[0024] 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 in the vehicle width direction of the opposing wall portion 26a. The rear frame 40 is connected to the outer wall portion 26b by bolt fastening or the like.

[0025] In this embodiment, the outer wall portion 26b has a projection (base portion) 26b1 that protrudes inward in the vehicle width direction. The tip of the rear frame 40 is fixed to the projection 26b1 by a bolt inserted through a hole formed in the tip surface of the projection 26b1 on the inner side in the vehicle width direction. The head of the bolt is housed in the space on the outer side of the projection 26b1 in the vehicle width direction.

[0026] 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 in the vehicle width direction of the opposing wall portion 26a. The inner wall portion 26c is inclined inward in the vehicle width direction as it approaches the rear. The rear frame 40 is connected to the inner wall portion 26c by bolt fastening or the like.

[0027] In this embodiment, a projection (base portion) 26c1 that protrudes to the rear is formed on the inner wall portion 26c. The tip of the rear frame 40 (more specifically, a flange portion (not shown) attached to the tip of the rear frame 40) is fixed to the projection 26c1 by a bolt inserted through a hole formed on the rear tip surface of the projection 26c1.

[0028] The lower wall portion 26d is part of the second lower wall portion 25 of the rear floor 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.

[0029] The rear frame connecting portion 26 is located at the rear of the rear floor panel body, forward of the notch 25a which is the rear end of the rear floor panel body. Furthermore, the rear frame connecting portion 26 is provided inward in the vehicle width direction from the inner end of the bulge portion 11 in the vehicle width direction, and at least a portion of the rear frame connecting portion 26 is positioned forward of the rear end of the bulge portion 11. Therefore, the rear body structure 1 can shorten the rear overhang of the vehicle body, thereby achieving weight reduction and increased freedom in vehicle body design.

[0030] The rear frame connecting portion 26 and the front end portion 41 of the rear frame 40 are located in front of the rear end portion of the drive unit 4. The rear of the drive unit 4 is positioned between a pair of left and right rear frames 40.

[0031] <Rib structure> As shown in Figures 4 and 5, the rear floor panel section 20 has multiple ribs formed on the main body of the rear floor panel to improve the rigidity of the main body of the rear floor panel, transmit load, and absorb collision energy.

[0032] <Rib structure on the upper surface> As shown in Figure 4, the rear floor panel 20 includes a plurality of left and right ribs 31, a plurality of front and rear ribs 32, a plurality of annular ribs 33, and a pair of left and right opposing ribs 34, which are erected on the upper side (inside the passenger compartment). These ribs can transmit loads in the direction along the ribs and absorb collision energy. In the following description, the front and rear ribs 32a, 32c, 37a, 37b, 37c (see Figure 5), which are inclined inward in the vehicle width direction as they move forward, will be referred to as load-transmitting ribs.

[0033] ≪Left and Right Ribs≫ The left and right ribs 31 are erected upward from the upper wall portion 21 of the rear floor panel main body and extend in the vehicle width direction. In this embodiment, both ends of the left and right ribs 31 in the vehicle width direction are connected to the bulging portion 11 of the rear wheel house portion 10.

[0034] ≪Front and back ribs≫ The front and rear ribs 32 are erected upward from the upper wall portion 21, front wall portion 22, and first lower wall portion 23 of the rear floor panel main body (they are erected forward from the front wall portion 22) and extend in the front-rear direction. Of the multiple front and rear ribs 32, the front and rear ribs 32 located on the outer side in the vehicle width direction are inclined so as they move forward in the vehicle width direction.

[0035] ≪Load Transfer Rib / Upper Rib≫ Of the multiple front and rear ribs 32, the left and right pair of front and rear ribs 32a on the inner side in the vehicle width direction are load-transmitting ribs (upper ribs) that are inclined inward in the vehicle width direction as they extend forward. The rear ends of the front and rear ribs 32a are located in front of the rear frame connecting 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 connecting portion 26. The front portion of the front and rear ribs 32a extends in the front-rear direction.

[0036] The pair of front and rear ribs 32c located on the outside in the vehicle width direction of the pair of front and rear ribs 32a are load-transmitting 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 32c are located in front of the rear frame connecting 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 connecting portion 26. The rear portions of the front and rear ribs 32a extend in the front-rear direction.

[0037] The angle θ of the inclined portion of the front and rear ribs 32a and 32c with respect to the front-rear direction is 30 degrees or less (for example, 30 degrees).

[0038] ≪Annular Rib≫ The annular rib 33 has a cylindrical shape in plan view and is provided in front of the rear frame connecting portion 26. In this embodiment, the annular rib 33 connects the front and rear ribs 32a, which serve as load-transmitting 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 to extend radially 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 divided either front and rear or left and right at the annular rib 33.

[0039] ≪Opposite Ribs≫ The opposing ribs 34 extend rearward from the opposing wall portion 26a of the rear frame connecting portion 26. In this embodiment, the opposing ribs 34 have a grid shape (for example, a honeycomb shape) when viewed from the rear. The rear end of the opposing ribs 34 is spaced apart from and opposite the front end of the rear frame 40.

[0040] <Rib structure on the lower side> As shown in Figure 5, the rear floor panel 20 includes a plurality of left and right ribs 36, a plurality of front and rear ribs 37, a plurality of annular ribs 38, and a reinforcing rib 39 as ribs erected on the underside (outside the passenger compartment).

[0041] ≪Left and Right Ribs≫ The left and right ribs 36 are erected downward from the upper wall portion 21 of the rear floor panel main body at positions corresponding to the upper left and right ribs 31, and extend in the vehicle width direction.

[0042] ≪Front and back ribs≫ The front and rear ribs 37 are erected downward from the upper wall portion 21, front wall portion 22, and 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 (they are erected rearward from the front wall portion 22), and they extend in the front-rear direction. Of the multiple front and rear ribs 37, the front and rear ribs 37 located on the outer side in the vehicle width direction are inclined to move outward in the vehicle width direction as they move forward.

[0043] ≪Load Transfer Rib / Lower Rib≫ Of the multiple front and rear ribs 37, the left and right pair of front and rear ribs 37a on the inner side in the vehicle width direction are load-transmitting 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 connecting 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 connecting portion 26. The front ends of the front and rear ribs 32a extend in the front-rear direction.

[0044] The front and rear ribs 37a and the adjacent front and rear ribs 37b are load-transmitting ribs (lower ribs) that are inclined inward in the vehicle width direction as they extend forward. The rear ends of the front and rear ribs 37b are located in front of the rear frame connecting portion 26. In this embodiment, the rear ends of the front and rear ribs 37b are connected to the annular rib 38.

[0045] The left and right front and rear ribs 37b located outside the left and right front and rear ribs 37b in the vehicle width direction are load-transmitting 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 37c are located in front of the rear frame connecting 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 connecting portion 26. The rear portions of the front and rear ribs 37b extend in the front-rear direction.

[0046] The angle θ of the inclined portion of the front and rear ribs 37a and 37b with respect to the front-rear direction is 30 degrees or less (for example, 30 degrees for the front and rear ribs 37a and 37c, and 15 degrees for the front and rear rib 37b).

[0047] ≪Annular Rib≫ As shown in Figure 7, the annular rib 38 has a cylindrical shape in plan view and is provided in front of the rear frame connecting portion 26. In this embodiment, the annular rib 38 connects the front and rear ribs 37a and 37b, which serve as load-transmitting 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 to extend radially 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 divided either front and rear or left and right at the annular rib 38.

[0048] Reinforcement Ribs As shown in Figure 5, the reinforcing rib 39 improves the rigidity of the rear floor panel 20 and extends downward from the upper wall 21 in the region enclosed by the pair of front and rear left and right ribs 36 and the pair of front and rear ribs 37a. The reinforcing rib 39 exhibits a grid shape (for example, a honeycomb shape) when viewed from below. In this embodiment, the reinforcing rib 39 is connected to the pair of front and rear left and right ribs 36 and the pair of front and rear ribs 37a. Note that the reinforcing rib 39 is not limited to a grid shape, and may be a rib only in the front and rear direction, a rib only in the left and right direction, or a rib with a mixture of these arranged irregularly.

[0049] <Upper and lower load-transfer ribs> As shown in Figures 4 and 5, the lower front and rear ribs 37a, 37b, and 37c are more numerous than the upper front and rear ribs 32a and 32c, acting as load-transmitting ribs that are directed inward in the vehicle width direction as they move forward.

[0050] As shown in Figure 8, in the front and rear ribs 32a and 37a, which act as load-transmitting ribs that move inward in the vehicle width direction as they extend forward, the upright height H2 of the lower front and rear rib 37a is greater than the upright height H1 of the upper front and rear rib 32a. This height relationship is also applicable to the other front and rear ribs 32 and 37, left and right ribs 31 and 36, and annular ribs 33 and 38.

[0051] The rear body structure 1 can suppress the accumulation of electrodeposited paint and prevent deterioration of paint quality by making the upper front and rear ribs 32a lower than the lower front and rear ribs 37a and fewer in number than the lower front and rear ribs 37a and 37b.

[0052] Furthermore, as described above, the front and rear ribs 32a, 32c, 37a, 37b, and 37c, which serve as load-transmitting ribs, only need to be able to transmit the rearward thrust 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 may be connected to the rear frame connection portion 26 (or the opposing wall portion 26a), or they may be located in front of the rear frame connection portion 26 (or the opposing wall portion 26a) and separated from it.

[0053] <Rear frame> As shown in Figures 3 and 4, the rear frame 40 is a cylindrical metal member extending in the front-rear direction. The rear frame 40 has a closed cross-sectional shape (octagonal in this embodiment) when viewed from the front. The rear frame 40 extends rearward from the rear floor panel 20. The front part of the rear frame 40 overlaps with the rear floor panel 20 in a plan view, and the rear part of the rear frame 40 protrudes behind the rear floor panel 20 in a plan view. The front end portion 41 of the rear frame 40 is connected to the rear frame connecting portion 26. Bumper beams (not shown) are mounted on the rear ends of the pair of left and right rear frames 40.

[0054] As shown in Figure 9, the distance W2 in the vehicle width direction between the rear frame 40 and the rear frame connecting portion 26 on one side in the vehicle width direction (for example, the left side) and the vehicle body end on the other side in the vehicle width direction (for example, the right side) is positioned so as to be within 70% (and greater than 50%) of the overall vehicle width W1.

[0055] <Rear frame mounting structure> As shown in Figures 4 and 6, the front end portion 41 of the rear frame 40 is connected to the rear frame connecting portion 26, facing the opposing rib 34 at a distance from it. That is, the outer wall portion of the front end portion 41 of the rear frame 40 is attached to the outer wall portion 26b of the rear frame connecting portion 26 by bolt fastening. Here, the protrusion 26b1 of the outer wall portion 26b is integrated with the lower part of the bulge portion 11 and is accessible from the outside in the vehicle width direction of the bulge portion 11. Therefore, bolt fastening can be performed using a jig X from the outside in the vehicle width direction of the bulge portion 11 of the rear wheel house portion 10 (see Figure 9).

[0056] As shown in Figure 3, the rear frame connecting portion 26, that is, the front end portion 41 of the rear frame 40 connected to the rear frame connecting portion 26, is positioned to overlap with the rear wheel 3 in a side view. The front end portion 41 of the rear frame 40 may also be positioned to overlap with the wheel 3a of the rear wheel 3 in a side view, 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 to which the rear frame 40 is connected is positioned to overlap with the tire 3b of the rear wheel 3 in a side view, and is accessible from the outside of the bulge portion 11 of the rear wheel house portion 10 (the space where the rear wheel 3 is housed, which is configured on the outside in the vehicle width direction of the bulge portion 11).

[0057] As shown in Figures 4 and 6, the inner wall portion of the front end portion 41 of the rear frame 40 is attached to the inner wall portion 26c of the rear frame connecting portion 26 by bolt fastening via a flange member (not shown). The bolt fastening can be performed from the rear of the inner wall portion 26c.

[0058] <Mounting structure of the drive unit> As shown in Figure 10, the drive unit 4 includes a power source (e.g., a motor) 4a for rotating a pair of left and right rear wheels 3, and a pair of left and right transmission units (e.g., shafts) 4b for transmitting the rotational force of the power source 4a to the rear wheels 3. The drive unit 4, more specifically the power source 4a of the drive unit 4, is located below the upper wall 21 in an area enclosed by the upper wall 21, the front wall 22, and the rear wall 24, and is attached to a plurality of drive unit mounting parts 27 by bolt fastening or the like. The plurality of drive unit mounting parts 27 are arranged to surround the reinforcing rib 39, which will be described later.

[0059] The drive unit mounting portion 27 is provided on each of the lower wall portions 26d of the left and right pair of rear frame connecting portions 26. Since the drive unit mounting portion 27 is provided on the rear frame connecting portion 26, which has improved strength due to the connection of the rear frame 40, the drive unit 4 can be held securely.

[0060] <Load transfer during rear-end collisions> During a rear-end collision, the rear impact load is transmitted from the left and right pair of rear frames 40 to the rear frame connecting portion 26 of the rear body structure 1. The rear impact load transmitted to the rear frame connecting portion 26 is then transmitted forward, distributed in the vehicle width direction, via the upper and lower front and rear ribs 32 and 37. Therefore, the rear body structure 1 can effectively transmit the rear impact load and effectively absorb collision energy as a whole, including the middle portion of the rear floor panel in the vehicle width direction.

[0061] In the event of a rear-end collision, the rear frame 40 deforms such that its rear end lifts. Specifically, 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. The rear structure 1 of the vehicle body has lower front and rear ribs 37 that deform in the tension direction that are higher and more numerous than upper front and rear ribs 32 that deform in the compression direction, so the rear-end load can be suitably transmitted via the lower front and rear ribs 37, which are less prone to deformation.

[0062] Furthermore, in the rear body structure 1, the angle θ of the front and rear ribs 32a, 32c, 37a, 37b, and 37c, which serve as load-transmitting ribs, with respect to the longitudinal direction is set to 30 degrees or less, thereby suppressing deformation of the ribs and effectively transmitting rear impact loads.

[0063] Furthermore, since the rigidity of the rear body structure 1 in the width direction is improved by the reinforcing ribs 39, deformation of the rear floor panel main body due to rear impact loads is suppressed, and rear impact loads can be transmitted more effectively.

[0064] Furthermore, the rear body structure 1 distributes the rear impact load to multiple front and rear ribs 32 and 37 by annular ribs 33 and 38, thereby enabling more effective transmission of the rear impact load.

[0065] An embodiment of the present invention provides a rear body structure 1 which integrally comprises a rear wheel house portion 10 and a rear frame connecting portion 26 to which a rear frame 40 is connected, by die-cast molding, wherein the rear wheel house portion 10 includes a bulging portion 11 that bulges inward in the vehicle width direction and covers the rear wheel 3, and at least a part of the rear frame connecting portion 26 is positioned forward of the rear end of the bulging portion 11. Therefore, the rear body structure 1 can shorten the rear overhang of the vehicle body by enabling the forward positioning of the rear frame 40. In other words, the rear body structure 1 can achieve weight reduction and increased freedom in vehicle body design.

[0066] In the rear body structure 1, the rear frame connecting portion 26 is provided at a position such that the distance in the vehicle width direction from the vehicle body end opposite to the rear frame connecting portion 26 in the vehicle width direction is within 70% of the overall width of the vehicle body. Therefore, the rear body structure 1 can withstand the load even during an offset rear-end collision, with both the left and right rear frames 40 bearing the load. In other words, the rear body structure 1 can reduce the input of the rear-end load to the left and right rear frames 40 during an offset rear-end collision, thereby achieving weight reduction including the rear frames 40.

[0067] In the rear body structure 1, the rear floor panel portion 20 is provided with opposing ribs 34 extending in the front-rear direction, and the opposing ribs 34 are positioned opposite the front end portion 41 of the rear frame 40. Therefore, the rear body structure 1 can effectively receive and transmit the rear impact load from the rear frame 40. Furthermore, the rear body structure 1 allows for adjustment of the length of the opposing ribs 34 according to the position of the front end 41 of the rear frame 40, thereby improving the degree of freedom in the installation position of the rear frame 40.

[0068] The rear body structure 1 integrally comprises a pair of left and right rear wheel well sections 10 and a rear floor panel section 20 connecting the pair of left and right rear wheel well sections 10, formed by die-cast molding, and the rear frame connecting section 26 is provided on the rear floor panel section 20. Therefore, the rear body structure 1 can improve the degree of freedom in the installation position of the rear frame connecting portion 26. In addition, since the rear body structure 1 can distribute the rearward impact load from the rear frame 40 to the left and right rear wheelhouse portions 10, it is possible to make the rear frame 40 smaller and shorten the rear overhang.

[0069] In the rear body structure 1, the rear end of the rear floor panel 20 is located between the left and right pair of rear wheel wells 10, and the rear frame connecting portion 26 is provided in front of the rear end of the rear floor panel 20. Therefore, the rear body structure 1 can secure space for component placement even when the rear overhang is shortened, and can ensure freedom in the body design. In addition, the rear body structure 1 can achieve miniaturization and weight reduction of the rear floor structure by making the left and right pair of rear wheelhouse sections 10 and the rear floor panel section 20 into a single die-cast section 2.

[0070] In the rear body structure 1, the front end portion 41 of the rear frame 40 is located in front of the rear end portion of the drive unit 4 which is positioned between the left and right pair of rear frames 40. Therefore, the rear body structure 1 can shorten the rear overhang while securing space for the drive unit 4. In addition, the rear body structure 1 can firmly hold the drive unit 4.

[0071] In the rear body structure 1, the rear frame connecting portion 26 is provided further inward in the vehicle width direction than the inner end of the bulging portion 11 in the vehicle width direction. Therefore, the rear structure 1 of the vehicle body allows the rear frame 40 to be positioned further forward.

[0072] In the rear body structure 1, the rear frame connecting portion 26 is configured to connect to the rear frame 40 from the outside of the rear wheel house portion 10. Therefore, the rear body structure 1 can achieve a forward positioning of the rear frame 40 while preventing a decrease in ease of installation.

[0073] In the rear body structure 1, the rear frame connecting portion 26 is positioned so as to overlap with the rear wheel 3 when viewed from the side. Therefore, the rear body structure 1 can shorten the rear overhang of the vehicle body by enabling the rear frame 40 to be positioned forward.

[0074] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above and can be modified as appropriate without departing from the spirit of the invention. [Explanation of symbols]

[0075] 1. Rear structure of the vehicle body 2 Die-cast parts 3 Rear wheels 4 Drive Unit 10 Rear wheel arch section 11. Bulging section (rear wheel well main body) 20 Rear floor panel section 21 Upper wall section (rear floor panel main body) 22 Front wall section (rear floor panel main body section) 23. First lower wall section (rear floor panel main body section) 24 Rear wall section (rear floor panel main body) 25. Second lower wall section (rear floor panel main body section) 25a Notch 26 Rear frame connection section 26a Opposing wall section 26b External wall 26c Inner wall 26d Lower wall part 27 Drive unit mounting section 31 Left and right ribs 32 Front and rear ribs 32a, 32c Front and rear ribs (load-transfer ribs, upper ribs) 33 Annular Ribs 34 Opposing Ribs 36 Left and right ribs 37 Front and rear ribs 37a, 37b, 37c Front and rear ribs (load-transfer ribs, lower ribs) 38 Annular Ribs 39 Reinforcement Ribs 40 Rear frame 41 Front end X Jig

Claims

1. A rear body structure comprising, integrally by die-cast molding, a pair of left and right rear wheelhouse sections, a rear floor panel section connecting the pair of left and right rear wheelhouse sections, and a rear frame connecting section to which the rear frame is connected, The rear wheel well section includes a bulge that extends inward in the vehicle width direction and covers the rear wheel. The rear frame connecting portion is provided on the rear floor panel portion. At least a portion of the rear frame connecting portion is positioned forward of the rear end of the bulging portion. A rear body structure characterized by the following.

2. The rear frame connecting portion is positioned such that the distance in the vehicle width direction from the vehicle body end opposite to the rear frame connecting portion in the vehicle width direction is within 70% of the total width of the vehicle body. The rear body structure of the vehicle according to feature 1.

3. The rear floor panel section is provided with opposing ribs extending in the front-rear direction, The opposing ribs are provided in a position opposite to the front end of the rear frame. The rear body structure of the vehicle according to feature 1.

4. Between the left and right pair of rear wheel wells, the rear end of the rear floor panel is located forward of the rear end of the bulge in the left and right pair of rear wheel wells. The rear frame connecting portion is provided in front of the rear end of the rear floor panel portion. The rear body structure of the vehicle according to feature 1.

5. The front end of the rear frame is located in front of the rear end of the drive unit, which is positioned between the left and right pair of rear frames. The rear body structure of the vehicle according to feature 1.

6. The rear frame connecting portion is provided further inward in the vehicle width direction than the inner end of the bulging portion in the vehicle width direction. The rear body structure of the vehicle according to feature 1.

7. The rear frame connecting portion is configured to allow connection of the rear frame from the outside of the vehicle to the rear wheel well portion. The rear body structure of the vehicle according to feature 1.

8. The rear frame connecting portion is positioned so as to overlap with the rear wheel when viewed from the side. The rear body structure of the vehicle according to feature 1.

Images