JP2009220717A - Vehicle body rear structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure predetermined mounting rigidity, and to attain light weight. <P>SOLUTION: The vehicle body rear structure 20 is provided with a rear frame 21 extended in a vehicle body longitudinal direction; and a spare tire pan 23 joined to the rear frame 21 and storing a spare tire. The rear frame 21 is a frame of a closed cross section structure and has an obliquely downwardly extended inner flange 42, and the spare tire pan 23 has a slope wall 61 formed on a side and formed along the inner flange 42. The slope wall 61 is joined to the inner flange 42 so as to become linear. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a rear structure of a vehicle body including a rear frame that extends in the longitudinal direction of the vehicle body and a spare tire pan that houses a spare tire.

As a rear structure of a vehicle body, a structure in which front and rear cross members are passed to left and right rear frames and a spare tire pan is attached to a space surrounded by the left and right rear frames and front and rear cross members is known.
This type of vehicle body rear structure is intended to increase the shock absorption capacity and secure the mounting rigidity of the spare tire pan so as to reduce the weight as much as possible.

As a technique that can be adopted in such a vehicle body rear structure, there is known a technique that uses an octagonal cross-section frame in order to improve the impact absorption capability (see, for example, Patent Document 1).
Japanese Patent No. 3070399

  The technique of Patent Document 1 discloses a frame having an octagonal cross section (polygonal cross section) that is formed in a closed cross section and extends in the longitudinal direction of the vehicle body and receives a compressive load in the axial direction when a vehicle collides. The first half of the length from the collision end side is formed in a cross-sectional shape with higher crushing strength than the second half, and the cross-section change between the front half and the second half changes from the first half to the closed cross-sectional shape of the second half The section changing portion is used as a heavy load supporting portion.

However, if such a frame having a polygonal cross section having an impact absorbing action is adopted as it is in the rear body structure of the vehicle body, it is possible to improve the shock absorbing action in the rear body structure, but it is possible to reduce the weight of the rear body structure. Can not.
Further, with respect to the spare tire pan attached to the frame (rear frame), it is desired to improve the rigidity of the single item and to reduce the weight of the single item.

  It is an object of the present invention to provide a vehicle body rear structure that can ensure a predetermined mounting rigidity and can be reduced in weight.

  The invention according to claim 1 is a vehicle body rear structure including a rear frame extending in the longitudinal direction of the vehicle body and a spare tire pan that is joined to the rear frame and accommodates a spare tire. The spare tire pan is formed on the side portion and has a sloped wall portion formed along the inner flange, and the inner flange has a sloped surface. The wall portions are joined so as to be linear.

  In the invention according to claim 2, the inner flange has a horizontal flange portion that is horizontal at the front portion of the spare tire pan, and the rear floor cross member extends from the lower portion of the horizontal flange portion to the vehicle body width inward. The front portion of the spare tire pan is supported by the rear floor cross member.

  According to a third aspect of the present invention, the spare tire pan includes a substantially vertical front wall portion supported by a rear floor cross member at a front portion, and the slope wall portion and the front wall are provided between the slope wall portion and the front wall portion. It is characterized by comprising a triangular wall portion that is continuously formed in the portion and improves the rigidity of the spare tire pan.

In the invention according to claim 1, the rear structure of the vehicle body includes a rear frame extending in the longitudinal direction of the vehicle body, and a spare tire pan that is joined to the rear frame and stores a spare tire.
The rear frame is a frame having a closed cross-sectional structure, and has an inner flange extending obliquely downward. The spare tire pan is formed on the side portion and has an inclined wall portion formed along the inner flange.

Since the sloped wall of the spare tire pan is joined to the inner flange of the rear frame that extends obliquely downward, for example, the transmission line is laid between steel towers with slack. Similar to the principle, in a state where the spare tire is stored in the spare tire pan, a large load is unlikely to act on the inner flange and the slope wall portion extending obliquely downward. Therefore, the predetermined strength can be satisfied even if the mounting rigidity of the rear frame and the spare tire is lowered. Thereby, the weight reduction of a vehicle body rear part structure can be achieved.
Further, since the sloped wall portion is formed in the spare tire pan, for example, the development area of the spare tire pan can be small as compared with the case where the wall surface portion is formed substantially vertically. Therefore, the spare tire pan itself can be reduced in weight, and the cost of the spare tire pan can be reduced.

  In the invention according to claim 2, the inner flange has a horizontal flange portion that is horizontal at the front portion of the spare tire pan, and the rear floor cross member extends from the lower portion of the horizontal flange portion to the vehicle body width inward. Since the front portion of the spare tire pan is supported by the rear floor cross member, the rigidity of the spare tire pan can be improved.

  In the invention according to claim 3, the spare tire pan includes a front wall portion that is substantially vertical and is supported by the rear floor cross member at the front portion, and the front wall to the front wall between the slope wall portion and the front wall portion. Since the triangular wall part continuously formed in the part is provided, the rigidity of the spare tire pan can be improved.

The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals. Fr is the front of the vehicle body, Rr is the rear of the vehicle body, L is the left side of the vehicle body, and R is the right side of the vehicle body.
1 is a perspective view of a vehicle body rear structure according to the present invention, FIG. 2 is a front view of the vehicle body rear structure shown in FIG. 1, and FIG. 3 is a plan view of the vehicle body rear structure shown in FIG. 4 is a side view of the vehicle body rear structure shown in FIG. 1, FIG. 5 is a sectional view taken along line 5-5 in FIG. 1, and FIG. 6 is a sectional view taken along line 6-6 in FIG.

  The vehicle body rear structure 20 is joined to the left and right rear frames 21 and 21 (the right rear frame is not shown) that extends in the vehicle longitudinal direction, and accommodates a spare tire (not shown) that is joined to the rear frames 21 and 21. The spare tire pan 23 and a rear floor cross member 24 provided at the front portion of the spare tire pan 23 are configured.

The vehicle body 11 is passed to a partition wall 15 that partitions the compartment 12 side and the cargo compartment 13 side, a wheel house 16 that covers a rear wheel (not shown), rear frames 21 and 21, and a spare tire pan 23. A floor panel 17 (see FIG. 6) is provided.
The rear frame 21 includes a rear frame upper 31 having an upper portion and a rear frame lower 32 having a lower portion.

The rear frame upper 31 includes an upper main body 34 formed in a convex shape above the vehicle body in a sectional view, and inner and outer upper flange portions 35 and 36 formed on both sides of the upper main body 34.
The rear frame lower 32 includes a lower main body 37 formed in a convex shape below the vehicle body in a cross-sectional view, and inner and outer lower flange portions 38 and 39 formed on both sides of the lower main body 37.

  Further, the rear frame 21 is formed by joining the inner upper flange portion 35 and the inner lower flange portion 38 and joining the outer upper flange portion 36 and the outer lower flange portion 39. That is, the frame main body 41 is formed in the space portion of the upper main body 34 and the lower main body 37, the inner flange 42 is formed by the inner upper flange portion 35 and the inner lower flange portion 38, and the outer upper flange portion 36 and the outer lower flange portion 39 are outside. A flange 43 is formed.

The rear frame 21 is a frame in which the frame body 41 is formed in a rectangular shape at the front and changes into a substantially octagonal shape at the rear, and front and rear mounting brackets 44 and 45 for attaching a chassis member 56 such as a subchassis to the lower end. Provided.
The inner flange 42 includes an inclined flange portion 46 that extends obliquely downward at the rear and a horizontal flange portion 47 that extends horizontally at the front.

  The rear mount bracket 45 includes a bracket main body 48 attached to the rear frame lower 32 and a stud 49 welded to the bracket main body 48. The front mounting bracket 44 is a bracket having substantially the same configuration as the rear mounting bracket 45. The chassis member 56 is fixed to the rear mount bracket 45 with bolts 57 and is fixed to the front mount bracket 44 with bolts (not shown).

  The stud 49 is provided with a welding flange 51 in the lower middle, a nut portion 52 to which the chassis member 56 is attached is formed at the lower end, and the welding flange 51 and the intermediate portion 53 of the stud 49 are welded to the bracket body 48.

The rear floor cross member 24 is a substantially L-shaped frame in cross-sectional view that extends in the vehicle width direction, and includes upper and lower welding flanges 54 and 55 that are welded to the spare tire pan 23 at the upper and lower ends. Is supported by the rear mounting bracket 45.
Further, as shown in FIGS. 5 and 6, the floor panel 17 is passed to the horizontal flange portion 47 of the inner flange 42 and the front flat portion 63 of the spare tire pan 23.

  7 is a perspective view of the spare tire pan of the rear structure of the vehicle body shown in FIG. 1, FIG. 8 is a sectional view taken along line 8-8 in FIG. 7, and FIG. 9 is a sectional view taken along line 9-9 in FIG. FIG. 10 is a sectional view taken along line 10-10 of FIG.

  The spare tire pan 23 is a bilaterally symmetric member, the left and right slope wall portions 61, 62, the front flat portion 63 formed in front of these slope wall portions 61, 62 and in the vehicle width direction, The front wall portion 69 extending substantially vertically downward from the front flat portion 63 is connected to the front end portion 61a of the left slope wall portion 61, the left end portion 82 of the front wall portion 69, and the front flat portion 63. Right-side first and second triangular walls connecting the first and second triangular wall portions 64, 65 on the left side with the front end portion 62a of the right slope wall portion 62, the right end portion 83 of the front wall portion 69, and the front flat portion 63. Portions 66 and 67, rear flat portions 68 connecting the lower ends 61b and 62b of the slope wall portions 61 and 62 at the rear portions of the left and right slope wall portions 61 and 62, and the left and right slope wall portions 61 and 62, respectively. A substantially vertical first connecting the lower ends 61b and 62b, the lower end 84 of the front wall portion 69, and the rear flat portion 68. A cylindrical wall surface portion 71, a second cylindrical wall surface portion 72 extending obliquely inward from the lower end 71 a of the first cylindrical wall surface portion 71, and a bottom surface portion connecting the lower end 72 a of the second cylindrical wall surface portion 72. 73, left and right slope wall side welding flanges 75, 76 provided on the left and right slope wall parts 61, 62 and connected to the slope flange parts 46, 46 of the inner flanges 42, 42, and the front flat part 63 The left and right front flat portion side welding flanges 77 and 78 are provided and connected to the horizontal flange portion 47 of the inner flange 42.

FIGS. 11A and 11B are comparative views of the vehicle body rear structure shown in FIG. 1, FIG. 11A shows a vehicle body rear structure 110 of a comparative example, and FIG. 11B shows a vehicle body rear part of the embodiment. Structure 20 is shown.
In (a), in the vehicle body rear structure 110, the inner flange 112 of the rear frame 111 is formed horizontally.
In the spare tire pan 114, a horizontal welding flange 115 to which the inner flange 112 is welded extends horizontally inward of the vehicle body, and a side wall portion 116 extends from the horizontal welding flange 115 substantially vertically. A bottom surface portion 117 extends horizontally inward of the vehicle body.

  In (b), the spare tire pan 23 has an inclined wall portion 61 (including an inclined wall portion-side weld flange 75) extending obliquely downward, and first and second cylindrical wall surface portions 71 and 72 (see FIG. 7). ) Is extended substantially vertically, and the bottom surface portion 73 is extended horizontally inwardly of the vehicle body.

  Here, when designing the spare tire pans 23 and 114 having the storage volume of the height H1 and the diameter D1, the dimensions of the horizontal welding flange 115 of the spare tire pan 114 of the comparative example shown in FIG. If the dimension of the side wall part 116 is A2 (A2 = H1), the dimension of the slope wall part 61 of the spare tire pan 23 of the embodiment shown in FIG. 5B is B1, and the dimension of the side wall part 86 is B2, then A1 + A2 > B1 + B2. That is, the development area of the spare tire pan 23 can be made smaller than the development area of the spare tire pan 114. Therefore, the spare tire pan 23 of the embodiment can be lighter than the spare tire pan 114 of the comparative example.

  In (a), in the vehicle body rear structure 110 of the comparative example, when a spare tire (not shown) is stored in the spare tire pan 114 and a vertical load W1 acts on the horizontal welding flange 115, the load W1 is horizontal. It acts as it is as a load in the peeling direction for peeling the welding flange 115.

  In (b), in the vehicle body rear structure 20 of the embodiment, when a spare tire (not shown) is housed in the spare tire pan 23 and a vertical load W1 acts on the slope wall side welding flange 75, the load W1 is decomposed into a load W2 parallel to the slope wall portion 61 and a load W3 perpendicular to the slope wall portion 61, and a load for peeling the slope wall portion side welding flange 75 becomes a load W3. That is, W1> W3.

  That is, the spare tire pan 23 of the example is superior in the peel strength of the welded portion as compared with the spare tire pan 110 of the comparative example. Further, the spare tire pan 23 may be less rigid in the flanges 46 and 75 (see FIG. 7) than the spare tire pan 110. Thereby, the spare tire pan 23 can be lower in rigidity than the spare tire pan 110, and the weight of the vehicle body 11 can be reduced.

That is, as shown in FIGS. 1 and 7, the vehicle body rear structure 20 includes a rear frame 21 that extends in the longitudinal direction of the vehicle body, and a spare tire that is joined to the rear frame 21 and stores a spare tire (not shown). And a pan 23.
The rear frame 21 is a frame having a closed cross-sectional structure, and has an inner flange 42 extending obliquely downward. The spare tire pan 23 has a slope wall portion 61 formed along the inner flange 42 while being formed on the side portion.

  Since the slope wall portion 61 of the spare tire pan 23 is joined to the inner flange 42 of the rear frame 21 that extends obliquely downward, for example, the transmission line is slackened so that the gap between the steel towers is increased. In the state where the spare tire is housed in the spare tire pan 23, a large load is unlikely to act on the inner flange 42 and the slope wall portion 61 that extend obliquely downward. Therefore, even if the mounting rigidity of the rear frame 21 and the spare tire is lowered, the predetermined strength can be satisfied. Thereby, weight reduction of the vehicle body rear part structure 20 can be achieved.

  In addition, since the slope wall portion 61 is formed in the spare tire pan 23, for example, the development area of the spare tire pan 23 can be small as compared with the case where the wall surface portion is formed substantially vertically. Accordingly, the spare tire pan 23 itself can be reduced in weight, and the cost of the spare tire pan 23 can be reduced.

  As shown in FIGS. 1 and 6, the inner flange 42 has a horizontal flange portion that is horizontal at the front portion of the spare tire pan 23, and the rear floor cross member extends inward of the vehicle body width from the lower portion of the horizontal flange portion. 24 is extended, and the front flat portion 63 and the front wall portion 69 of the spare tire pan 23 are supported by the rear floor cross member 24, so that the rigidity of the spare tire pan 23 can be improved.

  As shown in FIGS. 1 and 7, the spare tire pan 23 includes a substantially vertical front wall portion 69 supported by the rear floor cross member 24 at a front portion, and includes a slope wall portion 61 and a front wall portion 69. Since the triangular wall portions 64 and 65 are formed continuously from the inclined wall portion 61 to the front wall portion 69, the rigidity of the spare tire pan 23 can be improved.

  As shown in FIG. 7, the vehicle body rear structure 20 according to the present invention is provided with the first and second triangular wall portions 64 and 65. However, the present invention is not limited to this, and the first and second triangular wall portions are provided. 64 and 65 may be one triangular wall part. However, it is possible to secure higher spare tire pan rigidity by dividing the triangular wall portion into two triangular wall portions such as the first and second triangular wall portions 64 and 65.

  The vehicle body rear structure according to the present invention is suitable for use in passenger cars such as sedans and wagons.

1 is a perspective view of a vehicle body rear structure according to the present invention. It is a front view of the vehicle body rear part structure shown by FIG. It is a top view of the vehicle body rear part structure shown by FIG. It is a side view of the vehicle body rear part structure shown by FIG. FIG. 5 is a sectional view taken along line 5-5 of FIG. FIG. 6 is a sectional view taken along line 6-6 of FIG. FIG. 2 is a perspective view of a spare tire pan having a vehicle body rear structure shown in FIG. 1. FIG. 8 is a cross-sectional view taken along line 8-8 in FIG. 7. FIG. 9 is a cross-sectional view taken along line 9-9 in FIG. 7. FIG. 10 is a cross-sectional view taken along line 10-10 of FIG. FIG. 2 is a comparative study diagram of the vehicle body rear structure shown in FIG. 1.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 20 ... Car body rear part structure, 21 ... Rear frame, 23 ... Spare tire pan, 24 ... Rear floor cross member, 42 ... Inner flange, 61 ... Slope wall part, 64, 65 ... Triangle wall part (1st, 2nd triangle wall part) ), 69: Front wall portion.

Claims (3)

In a vehicle body rear structure including a rear frame extending in the longitudinal direction of the vehicle body and a spare tire pan that is joined to the rear frame and stores a spare tire,
The rear frame is a frame having a closed cross-sectional structure, and has an inner flange extending obliquely downward, and the spare tire pan is formed on a side portion and along the inner flange. Having a slope wall,
The vehicle body rear structure, wherein the slope wall portion is joined to the inner flange so as to be linear.   The inner flange has a horizontal flange portion that is horizontal at a front portion of the spare tire pan, and a rear floor cross member extends inward of the vehicle body width from a lower portion of the horizontal flange portion, and the spare floor cross member The vehicle body rear portion structure according to claim 1, wherein a front portion of the tire pan is supported.   The spare tire pan includes a substantially vertical front wall portion supported by the rear floor cross member at a front portion, and between the slope wall portion and the front wall portion, from the slope wall portion to the front wall portion. The vehicle body rear structure according to claim 2, further comprising a triangular wall portion that is continuously formed to improve rigidity of the spare tire pan.

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