Vehicle body rear part structure

Abstract

In a vehicle body rear part structure comprising a side sill 20 and a rear frame 40, a tip part of a frame floor part 49 is placed on an inner overhang part 27, and an inner roof part 25 is covered by a frame roof part 48, in which state the rear frame 40 is fixed to the side sill 20 by a rivet 65 or the like.

Description

Rear body structure

[0001] The present invention relates to a rear vehicle body structure including a side sill and a rear frame.

[0002] Various vehicle rear body structures including side sills and rear frames have been proposed (see, for example, Patent Document 1 (FIG. 3)).

[0003] Patent Document 1 will be described with reference to the following figure. Figure 12 is a cross-sectional view of a main part of a conventional vehicle rear structure. In this vehicle rear structure, a rear frame 104 is fitted from the inside of the vehicle body onto a side sill 101 consisting of a side sill outer 102 and a side sill inner 103, and the two components are joined at a joint 105. The rear frame 104 is a casting that is thicker than the side sill 101.

[0004] Consider the joining process of the side sill 101 and the rear frame 104. When the side sill 101 is stationary, the rear frame 104 is moved horizontally. In addition, the center of the height direction of the side sill 101 is aligned with the center of the height direction of the rear frame 104.

[0005] That is, in the conventional vehicle rear body structure, the rear frame 104 needs to be raised and lowered while moving horizontally relative to the side sill 101. It is not easy to fit the rear frame 104 while moving it horizontally, which increases the manufacturing cost of the vehicle rear body structure.

[0006] However, there is a demand to provide vehicles at low cost, and as part of this demand, there is a demand to reduce the manufacturing costs of the rear body structure.

[0007] Patent No. 7074039

[0008] An object of the present invention is to provide a rear vehicle body structure that can reduce manufacturing costs.

[0009] The invention according to claim 1 is a vehicle rear structure including a side sill and a rear frame extending rearward from the side sill, wherein the side sill includes a side sill outer disposed on the outside of the vehicle body and a side sill inner disposed on the inside of the side sill outer, the side sill inner comprising an inner wall portion extending vertically, an inner roof portion extending from the upper end of the inner wall portion to the outside of the vehicle body, an inner flange portion extending upward from the tip of the inner roof portion, and an inner overhang portion overhanging laterally towards the inside of the vehicle body from a midpoint in the height direction of the inner wall portion, the front portion of the rear frame comprising a frame wall portion extending vertically to present a U-shaped cross section, a frame roof portion extending from the upper end of the frame wall portion to the outside of the vehicle body, and a frame floor portion extending from the lower end of the frame wall portion to the outside of the vehicle body, the tip portion of the frame floor portion resting on the inner overhang portion and the frame roof portion covering the top of the inner roof portion, In this configuration, the rear frame has a front portion fixed to the side sill.

[0010] In the invention according to claim 1, the leading end of the frame floor is placed on the inner overhang, and the frame roof is placed over the inner roof. In other words, the rear frame can be fixed to the side sill simply by lowering it onto the stationary side sill from above. Horizontal movement of the rear frame is not required; it only needs to be moved from top to bottom. Moving the rear frame downward is easy. This reduces the manufacturing cost of the rear body structure.

[0011] 1 is a side view of a vehicle rear body structure according to the present invention. It is a view taken along arrow 2 in FIG. 1. (a) is a side view of a rear frame, (b) is a cross-sectional view along line b-b in (a), and (c) is a cross-sectional view along line c-c in (a). (a) is an enlarged view of section 4a in FIG. 3(b), (b) is an enlarged view of section b in (a), and (c) is a diagram showing a modified center of the rear frame. (a) is an exploded view of a side sill, and (b) is a cross-sectional view of the side sill. (a) is a diagram explaining the procedure for joining the rear frame to the side sill, (b) is a cross-sectional view along line 6b-6b in FIG. 2, (c) is an enlarged view of section c in (b), and (d) is an enlarged view of section d in (b). (a) is an exploded view of a front end connecting member, and (b) is a cross-sectional view of the front end connecting member. 8A is a diagram illustrating the procedure for joining the rear frame to the side sill and the procedure for joining the front end connecting member to the rear frame, (b) is a cross-sectional view taken along line 8b-8b in FIG. 2, (c) is an enlarged view of part c in (b), (d) is an enlarged view of part d in (b), and (e) is an enlarged view of part e in (b). (a) and (b) are diagrams illustrating the height position of the inner overhanging portion. (a) and (b) are diagrams illustrating modified examples of the inner overhanging portion. (a) and (b) are diagrams illustrating the function of the center of the rear frame. (b) is a cross-sectional view of a main part of a conventional rear vehicle body structure.

[0012] An embodiment of the present invention will be described below with reference to the accompanying drawings. In the drawings, front, rear, top, bottom, inside and outside of the vehicle body are defined relative to the driver sitting in the vehicle.

[0013] [Vehicle Body Rear Structure] As shown in FIG. 1 , the vehicle body rear structure 10 includes a side sill 20 , a rear frame 40 extending rearward from the side sill 20 , and a rear wheel house 12 disposed outside the rear frame 40 .

[0014] 2, the rear vehicle body structure 10 includes a floor cross member 14 that is disposed in front of the rear frame 40 and extends from the side sill 20 toward the inside of the vehicle body, and a front end connecting member 60 that connects the front end of the rear frame 40 to the floor cross member 14. Note that the floor panel is omitted from FIG. 2.

[0015] [Rear Frame] As shown in Fig. 3(a), the rear frame 40 is a long material that extends in the front-rear direction. Preferably, the rear frame 40 is a die-cast product made of an aluminum alloy. The aluminum alloy is a light alloy, which can reduce the weight of the rear frame 40. However, to further reduce the weight, the first groove 41 and the second groove 42 are hollowed out.

[0016] By providing the first groove 41 and the second groove 42, further weight reduction is achieved, but strength is reduced. Therefore, preferably, the first groove 41 is provided with a plurality of I-shaped ribs 43 (two in this example) extending up and down, and the second groove 42 is provided with a plurality of I-shaped ribs 43 (six in this example) extending up and down. The portions above the first groove 41 and the second groove 42 form frame flange portions 44. In addition, inner rib-like flanges 45 are shown by dashed lines between the first groove 41 and the second groove 42 and below the second groove 42.

[0017] The rear frame 40 shown in Fig. 3(a) is offset in the front-to-back direction of the drawing, and therefore the cross section differs depending on the location in the fore-and-aft direction of the vehicle body. Therefore, the cross section at the front will be described with reference to Fig. 3(b), and the cross section at the center will be described with reference to Fig. 3(c).

[0018] 3(b), the front portion of the rear frame 40 has a frame wall portion 47 extending vertically, a frame roof portion 48 extending from the upper end of the frame wall portion 47 to the outside of the vehicle body, a frame flange portion 44 extending upward from the tip of the frame roof portion 48, and a frame floor portion 49 extending from the lower end of the frame wall portion 47 to the outside of the vehicle body, and presents a U-shaped cross section that gradually widens outward. The first groove 41 is reinforced by an I-shaped rib (43 in FIG. 3(a)) that crosses the U-shaped cross section.

[0019] Preferably, the rear frame 40 further includes an inner rib-like flange 45 that projects laterally toward the inside of the vehicle body from the upper end of the frame wall portion 47. Details of the inner rib-like flange 45 will be described later with reference to FIG.

[0020] 3(c), the center of the rear frame 40 includes a frame wall portion 47 extending vertically, a frame roof portion 48 extending from the upper end of the frame wall portion 47 to the outside of the vehicle body, a frame flange portion 44 extending upward from the tip of the frame roof portion 48, and a frame floor portion 49 extending from the lower end of the frame wall portion 47 to the outside of the vehicle body. Preferably, the rear frame 40 further includes an inner rib-like flange 45 projecting laterally from the lower end of the frame wall portion 47 to the inside of the vehicle body. The second groove 42 is reinforced by an I-shaped rib 43 that crosses the U-shaped cross section.

[0021] [Inner Rib-Like Flange] As shown in Fig. 4(a), the thickness t1 of the inner rib-like flange 45 at its base is set to be approximately equal to the thickness t2 of the frame wall portion 47. The inner rib-like flange 45 is a pointed tapered rib whose thickness decreases toward its tip due to a draft angle during casting. The pointed tapered rib may have a protruding tip, but is preferably round with a radius R, as shown in Fig. 4(b). The round shape helps prevent chipping at the tip.

[0022] The inner rib-like flange 45 is a tapered rib with a pointed tip, which can suppress weight increase. Furthermore, the tapered rib with a pointed tip ensures a draft angle during casting, making it extremely easy to separate the inner rib-like flange 45 from the casting mold.

[0023] 4( c ), the inner rib-like flange 45 may protrude toward the inside of the vehicle body from midway in the height direction of the frame wall portion 47. Thus, the inner rib-like flange 45 can protrude from any position on the frame wall portion 47.

[0024] [Side Sill] Next, the structure of the side sill 20 will be described with reference to Figures 5(a) and (b). As shown in Figure 5(a), the side sill 20 is composed of a side sill outer 21 arranged on the outside of the vehicle body, a reinforcing member 22 arranged on the inside of the vehicle body from the side sill outer 21, and a side sill inner 23 arranged on the inside of the vehicle body from the reinforcing member 22. Note that the reinforcing member 22 is not an essential component, as it is provided as needed.

[0025] The side sill outer 21, the reinforcing member 22, and the side sill inner 23 are preferably press-formed products made of steel plate. Press-formed products are also called pressed parts.

[0026] [Side sill inner] The side sill inner 23 comprises an inner wall portion 24 extending vertically, an inner roof portion 25 extending from the upper end of the inner wall portion 24 to the outside of the vehicle body, an inner flange portion 26 extending upward from the tip of the inner roof portion 25, an inner protrusion portion 27 protruding laterally toward the inside of the vehicle body from midway along the height of the inner wall portion 24, and an inner floor portion 28 extending from the lower end of the inner wall portion 24 to the outside of the vehicle body.

[0027] 5(a), the inner protruding portion 27 is a cut-and-raised piece 32 obtained by, for example, making a cut 31 in the inner wall portion 24 and bending it by about 90 degrees as shown by the arrow. The cut-and-raised piece 32 is formed simultaneously during the pressing process.

[0028] As shown in FIG. 5B, the side sill outer 21, the reinforcing member 22, and the side sill inner 23 are stacked on top of each other and joined together by spot welding nuggets 33 or the like, thereby obtaining the side sill 20.

[0029] [Effect of the cut-and-raised piece] An opening 34 corresponding to the size of the cut-and-raised piece 32 is formed in the inner wall portion 24. This opening 34 serves as a passage for paint when electrodeposition coating is applied to the side sill 20. Because the opening 34 is sufficiently large, a sufficient amount of paint flows in and out of the opening 34. As a result, electrodeposition coating of the side sill 20 is performed well, and the rust prevention performance of the side sill 20 is improved.

[0030] [Method of Joining Vehicle Rear Body Structure at a Portion Not Including Front End Connecting Member 60] A method of joining the side sill 20 and the rear frame 40 in the cross section taken along line 6b-6b in FIG. 2 will be described with reference to FIGS. 6(a) to 6(d).

[0031] 6(a), first, the rear frame 40 is moved downward relative to the stationary side sill 20. Specifically, the leading end of the frame floor 49 is placed on the inner protrusion 27 as indicated by the arrow (1), the frame roof 48 is placed on the inner roof 25 from above as indicated by the arrow (2), and the frame flange 44 is attached to the inner flange 26.

[0032] 6(b), the joining portions are joined by at least one of mechanical fastening, fusion welding, and adhesive bonding (rivets 65 in this example). Mechanical fastening may be performed using bolts or screws in addition to rivets 65. Fusion welding may be performed using friction stir welding, spot welding, laser welding, or the like. Adhesion is preferably performed using a one-component adhesive or a two-component adhesive.

[0033] As shown in Fig. 6(c), the side sill outer 21, the reinforcing member 22, the inner flange portion 26 of the side sill inner 23, and the frame flange portion 44 may be joined together with, for example, rivets 65. Also, as shown in Fig. 6(d), the inner protrusion 27 and the frame floor portion 49 may be joined together with, for example, rivets 65.

[0034] [Front End Connecting Member] Details of the front end connecting member 60 shown in Figure 2 will be described with reference to Figures 7(a) and (b). As shown in Figure 7(a), the front end connecting member 60 comprises a connecting portion floor 61, a connecting portion wall 62 rising from one end of the connecting portion floor 61, and a connecting portion roof 63. Preferably, the connecting portion floor 61 and the rising connecting portion wall 62 are integrally formed by press-forming a steel plate into an L-shaped cross section. Alternatively, the connecting portion roof 63 is obtained by press-forming a steel plate into an I-shaped cross section.

[0035] 7(b), the connecting roof 63 is placed on the connecting wall 62 to form a generally U-shaped cross section, but the two are not yet joined together.

[0036] [Method of joining the rear vehicle body structure at a portion including the front end connecting member 60] The method of joining the side sill 20, the rear frame 40, and the front end connecting member 60 in the cross section taken along line 8b-8b in Figure 2 will be described with reference to Figures 8(a) to 8(e). As shown in Figure 8(a), first, the connecting portion floor 61 and the connecting portion wall 62 are raised relative to the stationary side sill 20, and the connecting portion floor 61 is brought into contact with the inner protrusion 27 (arrow (3)).

[0037] Next, the rear frame 40 is moved from top to bottom. Specifically, the leading end of the frame floor 49 is placed on the inner overhang 27 as shown by arrow (4), the frame roof 48 is placed over the inner roof 25 as shown by arrow (5), and the frame flange 44 is attached to the inner flange 26. At the same time, the inner rib-like flange 45 is placed on the upper end of the connecting wall 62 (arrow (6)).

[0038] That is, the rear frame 40 is set by moving from top to bottom on the connecting portion floor portion 61 and connecting portion wall portion 62, which have an L-shaped cross section with an open top.

[0039] Next, as shown by arrow (7), the connecting roof portion 63 is placed on the frame roof portion 48, and as shown by arrow (8), one end of the connecting roof portion 63 is placed on the inner rib-like flange 45. Then, as shown in Figure 8(b), the joining portions are joined by at least one of mechanical fastening, fusion welding, and adhesive bonding.

[0040] As shown in Figure 8(c), the side sill outer 21, the reinforcing member 22, the inner flange 26 of the side sill inner 23, and the frame flange 44 are joined together, for example, with rivets 65. As shown in Figure 8(d), the inner protrusion 27, the frame floor 49, and the connecting portion floor 61 are joined together, for example, with rivets 65. As shown in Figure 8(e), the inner rib-like flange 45, the connecting portion wall 62, and the connecting portion roof 63 are joined together, for example, with rivets 65.

[0041] 8(b), the connecting portion floor portion 61 is shaped to fit the frame floor portion 49, the connecting portion wall portion 62 is shaped to fit the frame wall portion 47, and the connecting portion roof portion 63 is shaped to fit the frame roof portion 48. Therefore, the front end connecting member 60 can surround the front end of the rear frame 40.

[0042] 9(a), for a rear frame 40 having a height dimension H1, the inner protrusion 27 is provided at a middle position in the height direction of the inner wall 24. As shown in FIG. 9(b), for a rear frame 40 having a height dimension H2 greater than the height dimension H1, the inner protrusion 27 is provided at a lower position in the height direction of the inner wall 24.

[0043] In other words, the inner protrusion 27 can protrude from the middle of the height direction of the inner wall portion 24 at any height, and as a result, the height dimension of the rear frame 40 can be freely selected, thereby increasing the freedom of design of the rear frame 40.

[0044] 10(a), the inner protrusion 27 may be a bracket 36 that is separate (a separate part) from the inner wall 24. The bracket 36 is preferably an angle (an angle iron), but may also be a horizontally extending strip plate (an I-section steel plate).

[0045] As shown in Fig. 10(b), the bracket 36 is joined to the inner wall portion 24 by mechanical bonding, fusion welding, or adhesive. The height position of the bracket 36 can be set arbitrarily. In other words, the same effects as those in Figs. 9(a) and (b) can be obtained.

[0046] 11( a), the center of the rear frame 40 includes a frame wall portion 47 extending vertically, a frame roof portion 48 extending from the upper end of the frame wall portion 47 to the outside of the vehicle body, a frame flange portion 44 extending upward from the tip of the frame roof portion 48, a frame floor portion 49 extending from the lower end of the frame wall portion 47 to the outside of the vehicle body, and an inner rib-like flange 45 projecting laterally from the lower end of the frame wall portion 47 to the inside of the vehicle body. The rear wheel house 12 is brought into contact with the frame flange portion 44 by moving laterally from the outside to the inside of the vehicle body. The floor panel 16 is also placed on the inner rib-like flange 45 by moving it from top to bottom.

[0047] As shown in FIG. 11B, the rear wheel house 12 is joined to the frame flange portion 44 with, for example, rivets 65, and the floor panel 16 is joined to the inner rib-like flange 45 with, for example, rivets 65.

[0048] Based on the above, the present invention can be summarized as follows: As shown in Fig. 1, a vehicle rear structure 10 includes a side sill 20 and a rear frame 40 extending rearward from the side sill 20, and as shown in Fig. 5(a), the side sill 20 includes a side sill outer 21 disposed on the outside of the vehicle body and a side sill inner 23 disposed on the inside of the vehicle body relative to the side sill outer 21, and the side sill inner 23 includes an inner wall portion 24 extending vertically, an inner roof portion 25 extending from the upper end of the inner wall portion 24 to the outside of the vehicle body, an inner flange portion 26 extending upward from the tip of the inner roof portion 25, and an inner protrusion portion 27 protruding laterally toward the inside of the vehicle body from a midpoint in the height direction of the inner wall portion 24, As shown in Figure 3(b), the front portion of the rear frame 40 comprises a frame wall portion 47 extending vertically to present a U-shaped cross section, a frame roof portion 48 extending from the upper end of the frame wall portion 47 to the outside of the vehicle body, and a frame floor portion 49 extending from the lower end of the frame wall portion 47 to the outside of the vehicle body; as shown in Figure 6(a), the tip of the frame floor portion 49 is placed on the inner protrusion portion 27, and the frame roof portion 48 is placed over the inner roof portion 25; and in this configuration, the front portion of the rear frame 40 is fixed to the side sill 20, as shown in Figure 2.

[0049] As shown in Figure 6(a), the rear frame 40 can be set simply by moving it from top to bottom onto the side sill inner 23. Since no lateral movement is required, manufacturing is easier and manufacturing costs can be reduced.

[0050] Preferably, as shown in Fig. 3(b), the rear frame 40 further includes an inner rib-like flange 45 that protrudes laterally toward the inside of the vehicle body from the upper end of the frame wall portion 47. Alternatively, as shown in Fig. 4(c), the rear frame 40 further includes an inner rib-like flange 45 that protrudes laterally toward the inside of the vehicle body from a midpoint in the height direction of the frame wall portion 47.

[0051] The reinforcing effect of the inner rib-like flange 45 can increase the strength of the rear frame 40. Changing the height position of the inner rib-like flange 45 can change the load distribution characteristics during a collision. Furthermore, when a front end connecting member 60 is provided as shown in FIG. 8( b), a portion of the front end connecting member 60 can be joined to the inner rib-like flange 45 as shown in FIG. 8( e), making it easier to attach the front end connecting member 60.

[0052] Preferably, as shown in FIGS. 10( a ) and 10 ( b ), the inner protruding portion 27 is a bracket 36 that is separate from the inner wall portion 24 .

[0053] The bracket 36 can have any cross-sectional shape, such as an L-shaped cross section or a horizontally extending I-shaped cross section. Because it is a separate component, the bracket 36 can be attached to the inner wall portion 24 at any height. As a result, the degree of freedom in designing the rear frame 40 is increased.

[0054] Preferably, as shown in FIGS. 5( a ) and 5 ( b ), the inner protruding portion 27 is a cut-and-raised piece 32 formed by making a cut 31 in the inner wall portion 24 and bending it.

[0055] The inner protrusion 27 is formed integrally with the inner wall 24, eliminating the need for a separate component. The inner protrusion 27 can be provided at any height on the inner wall 24. This increases the degree of freedom in designing the rear frame 40. Furthermore, an opening 34 is formed in the inner wall 24 by cutting and raising. This opening 34 is used as an entrance and exit for paint during electrodeposition coating.

[0056] Preferably, as shown in Figure 2, the rear body structure 10 further includes a floor cross member 14 that extends perpendicular to the side sill inner 23 toward the inside of the vehicle body, and a front end connecting member 60 that connects the rear frame 40 and the floor cross member 14, and as shown in Figure 8 (b), this front end connecting member 60 consists of a connecting portion floor portion 61 that runs along the frame floor portion 49, a connecting portion wall portion 62 that runs along the frame wall portion 47, and a connecting portion roof portion 63 that runs along the frame roof portion 48, and the front end connecting member 60 surrounds the front end of the rear frame 40.

[0057] As shown in Figure 2, the front end connecting member 60 connects the rear frame 40 and the floor cross member 14, thereby increasing the strength of the vehicle rear body structure 10 against a rear collision. The front end connecting member 60 firmly fixes the front portion of the rear frame 40, which is a die-cast product, to the side sill inner 23 and floor cross member 14, which are pressed steel plate products. Also, as shown in Figure 8(a), the front end connecting member 60 can be assembled by moving the rear frame 40 downward, making it easier to assemble the rear frame 40 and the front end connecting member 60.

[0058] Preferably, as shown in Figure 11(a), the vehicle rear structure 10 further includes a rear wheel house 12 and a floor panel 16, and the center of the rear frame 40 is provided with a frame wall portion 47 extending vertically, a frame roof portion 48 extending from the upper end of the frame wall portion 47 to the outside of the vehicle body, a frame flange portion 44 extending upward from the tip of the frame roof portion 48, a frame floor portion 49 extending from the lower end of the frame wall portion 47 to the outside of the vehicle body, and an inner rib-like flange 45 protruding laterally from the lower end of the frame wall portion 47 to the inside of the vehicle body, and as shown in Figure 11(b), the rear wheel house 12 is joined to the frame flange portion 44, and the floor panel 16 is joined to the inner rib-like flange 45.

[0059] The rear wheel house 12 and the rear frame 40 can be assembled in the left-right direction, and the floor panel 16 and the rear frame 40 can be assembled in the up-down direction, which facilitates assembly of the rear part of the vehicle body and improves productivity.

[0060] Preferably, the rear frame 40 is a die-cast product made of aluminum alloy, and the front end connecting member 60 is a press-formed product made of steel plate. As shown in FIG. 2, the rear frame 40 and the front end connecting member 60 are joined by at least one of mechanical fastening, fusion welding, and adhesive bonding (in this embodiment, rivets 65).

[0061] It is possible to join dissimilar materials, such as aluminum alloy and steel plate.

[0062] Preferably, as shown in FIGS. 3(a) and 3(c), the rear frame 40 has a plurality of I-shaped ribs 43 that cross the U-shaped cross section.

[0063] The strength and rigidity of the rear portion of the vehicle body can be increased while suppressing an increase in the weight of the rear frame 40. Impact energy can be absorbed in the event of a rear collision.

[0064] Preferably, as shown in Figures 3(a) to (c), the rear frame 40 has an inner rib-like flange 45 that protrudes laterally from the frame wall portion 47 toward the inside of the vehicle body, and as shown in Figure 4(a), this inner rib-like flange 45 is a pointed tapered rib, and the thickness t1 of the base of this tapered rib is set to be approximately equal to the thickness t2 of the frame wall portion 47.

[0065] Providing the inner rib-like flange 45 can increase the strength and rigidity of the rear frame 40. Providing this inner rib-like flange 45 over the entire length of the rear frame 40 can reduce the weight of the rear frame 40 while maintaining or improving the strength and rigidity of the rear frame 40.

[0066] 4(a) and 4(c), the inner rib-like flange 45 can be provided at any height position on the frame wall portion 47. If the height position of the floor panel 16 shown in FIG. 11(b) changes, the height position of the inner rib-like flange 45 can be easily changed to match the height position of the floor panel 16. As a result, the degree of freedom in designing the floor panel 16 is increased.

[0067] Furthermore, since the inner rib-like flange 45 is formed as a tapered rib with a pointed tip, a draft angle is ensured, which facilitates demolding after casting and increases the productivity of cast rear frames.

[0068] The present invention is suitable for a vehicle rear body structure including a side sill and a rear frame.

[0069] 10...rear body structure, 12...rear wheelhouse, 14...floor cross member, 16...floor panel, 20...side sill, 21...side sill outer, 22...reinforcing member, 23...side sill inner, 24...inner wall portion, 25...inner roof portion, 26...inner flange portion, 27...inner protrusion portion, 28...inner floor portion, 31...notch, 32...raised piece, 36...bracket, 40...rear frame, 43...I-shaped rib, 44...frame flange portion, 45...inner rib-shaped flange, 47...frame wall portion, 48...frame roof portion, 49...frame floor portion, 60...front end connecting member, 61...connecting portion floor portion, 62...connecting portion wall portion, 63...connecting portion roof portion.

Claims

1. A vehicle rear structure including a side sill and a rear frame extending from the side sill toward the rear of the vehicle body, wherein the side sill includes a side sill outer disposed on the outside of the vehicle body and a side sill inner disposed on the inside of the side sill outer, wherein the side sill inner comprises an inner wall portion extending vertically, an inner roof portion extending from the upper end of the inner wall portion to the outside of the vehicle body, an inner flange portion extending upward from the tip of the inner roof portion, and an inner overhang portion overhanging laterally toward the inside of the vehicle body from the middle of the height direction of the inner wall portion, wherein the front portion of the rear frame comprises a frame wall portion extending vertically to present a U-shaped cross section, a frame roof portion extending from the upper end of the frame wall portion to the outside of the vehicle body, and a frame floor portion extending from the lower end of the frame wall portion to the outside of the vehicle body, wherein the tip of the frame floor portion rests on the inner overhang portion and the frame roof portion is placed over the inner roof portion, In this configuration, the rear frame is a vehicle rear structure whose front portion is fixed to the side sill.

2. A vehicle rear structure as claimed in claim 1, wherein the rear frame further comprises an inner rib-like flange that projects laterally inward from the upper end or midway in the height direction of the frame wall portion.

3. A vehicle rear structure according to claim 1, wherein the inner protruding portion is a bracket separate from the inner wall portion.

4. A vehicle rear structure according to claim 1, wherein the inner protruding portion is a cut-and-raised piece formed by cutting and bending the inner wall portion.

5. A vehicle rear structure as claimed in claim 1, further comprising a floor cross member extending inward of the vehicle body perpendicular to the side sill inner, and a front end connecting member connecting the rear frame and the floor cross member, the front end connecting member comprising a connecting floor portion that runs along the frame floor portion, a connecting wall portion that runs along the frame wall portion, and a connecting roof portion that runs along the frame roof portion, the front end connecting member surrounding the front end of the rear frame.

6. A vehicle rear structure as claimed in claim 1, further comprising a rear wheel house and a floor panel, wherein the centre of the rear frame comprises a frame wall section extending vertically, a frame roof section extending from the upper end of the frame wall section to the outside of the vehicle body, a frame flange section extending upward from the tip of the frame roof section, a frame floor section extending from the lower end of the frame wall section to the outside of the vehicle body, and an inner rib-like flange projecting laterally from the lower end of the frame wall section to the inside of the vehicle body, wherein the rear wheel house is joined to the frame flange section and the floor panel is joined to the inner rib-like flange.

7. A vehicle rear structure according to claim 1, wherein the rear frame is provided with a plurality of I-shaped ribs that cross the U-shaped cross section.

8. A vehicle rear structure according to claim 5, wherein the rear frame is a die-cast product of aluminum alloy, the front end connecting member is a press-formed product of steel plate, and the rear frame and the front end connecting member are joined by at least one of mechanical fastening, fusion welding, and adhesive bonding.

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