JP2014091346A - Vehicle rear part structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle rear part structure which restricts the occurrence of twist at a vehicle rear part against a vertical direction load inputted through a rear side member.SOLUTION: A rear part 10A of a vehicle 10 comprises: a rear floor panel 12; a pair of rear side members 14 which are arranged at both sides of the rear floor panel 12 in a vehicle width direction; a lower back panel 16 which extends from a rear end part of the rear floor panel 12 to an upper side of the vehicle; and quarter panels 20 which are bonded to both sides of the lower back panel 16 in the vehicle width direction. A lower back reinforcement 18 arranged at an upper side of the lower back panel 16 is provided forming a closed section together with the lower back panel 16. The lower back panel 16 includes, in a longitudinal cross-sectional view, an outer vertical wall part 16C which is formed so that a mating face with the rear side member 14 and a mating face with the lower back reinforcement 18 are approximately on a same surface having no positional offset therebetween in a vehicle longitudinal direction.

Description

  The present invention relates to a vehicle rear structure.

  Patent Document 1 below discloses a structure in which an extension of a lower back of a vehicle is superposed on a closed cross section of a rear side member, and an upper connecting portion of the extension is inserted into a closed cross section of the lower back reinforcement.

JP 2001-171557 A JP 2010-162913 A JP 2008-168711 A

  In the technique described in Patent Literature 1, the position of the mating surface of the lower back and the rear side member and the mating surface of the lower back and the lower back reinforcement are different in the vehicle front-rear direction, and the upper portion of the lower back is positioned between the upper and lower mating surfaces. It arrange | positions diagonally so that the side may become a vehicle rear side rather than the lower part side. For this reason, there is a possibility that the torsion of the rear portion of the vehicle may occur with respect to the vertical load input through the rear side member during vehicle travel. There is room.

  In view of the above fact, an object of the present invention is to obtain a vehicle rear portion structure that can suppress the occurrence of twisting of the vehicle rear portion with respect to a vertical load input through a rear side member.

  A vehicle rear structure according to the invention of claim 1 is provided at the rear of the vehicle, and is disposed on both sides of the rear floor in the vehicle width direction of the vehicle and in the vehicle front-rear direction. A pair of rear side members extending along the vehicle, and a lower back that extends from the rear end portion of the rear floor in the vehicle front-rear direction toward the vehicle upper side and that joins the rear end portion of the rear side member in the vehicle front-rear direction. A lower back reinforcement disposed at an upper portion of the lower back and forming a closed cross-section with the lower back; and provided at both ends in the vehicle width direction of the rear portion of the vehicle and extending along the vehicle front-rear direction. A quarter panel joined to a vehicle width direction end of the lower back, and a front surface and a mating surface provided with the rear side member provided in the lower back in a longitudinal sectional view Having a formed wall portion so as to be substantially flush with no offset longitudinal direction of the vehicle between the mating surfaces of the lower back reinforcement.

  According to a second aspect of the present invention, in the vehicle rear portion structure according to the first aspect, the lower back is located on the mating surface with the rear side member from the inner end in the vehicle width direction to the outer side in the vehicle width direction, and the rear floor in the longitudinal sectional view. Between the mating surface and the mating surface of the lower back reinforcement are formed to be substantially the same surface with no offset in the vehicle front-rear direction.

  According to a third aspect of the present invention, in the vehicle rear portion structure according to the first or second aspect, the lower back is a longitudinal sectional view from the vehicle width direction inner side end portion of the mating surface with the rear side member to the vehicle width direction inner side. Thus, the gap between the mating surface with the rear floor and the mating surface with the lower back reinforcement is formed so as to be substantially the same surface with no offset in the vehicle longitudinal direction.

  According to a fourth aspect of the present invention, in the vehicle rear portion structure according to any one of the first to third aspects, the lower back or the lower back reinforcement is a combination of the lower back and the lower back reinforcement. A vertical wall portion formed so as not to be offset in the vehicle front-rear direction with respect to the mating surface in a longitudinal sectional view is provided at the vehicle upper portion from the surface.

  According to a fifth aspect of the present invention, in the vehicle rear portion structure according to any one of the first to fourth aspects, the lower back is an inner end in the vehicle width direction of the mating surface with the rear side member in a cross-sectional view. And between the mating surfaces with the quarter panel are formed to be substantially the same surface with no offset in the vehicle longitudinal direction.

  According to the first aspect of the present invention, the pair of rear side members extending along the vehicle front-rear direction are arranged on both sides of the rear floor in the vehicle width direction, and the vehicle upper side from the rear end of the rear floor in the vehicle front-rear direction. The rear back extends toward the rear, and the rear end of the rear side member in the vehicle front-rear direction is joined to the lower back. A closed cross section is formed by the lower back reinforcement and the lower back arranged on the upper part of the lower back. A quarter panel extends along the vehicle longitudinal direction at both ends in the vehicle width direction of the rear portion of the vehicle, and the rear end portion of the quarter panel is joined to the vehicle width direction end portion of the lower back. Further, the lower back is formed with a wall surface portion so that a space between the mating surface with the rear side member and the mating surface with the lower back reinforcement is substantially the same surface without an offset in the vehicle front-rear direction in a longitudinal sectional view. . Thus, the load in the vertical direction input through the rear side member is efficiently transmitted from the wall surface portion of the lower back to the mating surface of the lower back and the lower back reinforcement. For this reason, generation | occurrence | production of the twist of a vehicle rear part can be suppressed efficiently, without adding components to the up-down direction load from the rear-end part of a rear side member, or increasing a board thickness.

  According to the second aspect of the present invention, the lower back is formed between the mating surface with the rear floor and the lower back reinforcement in a longitudinal sectional view from the vehicle width direction inner side end of the mating surface with the rear side member. The space between the mating surfaces is substantially the same surface with no offset in the vehicle longitudinal direction. As a result, the load in the vertical direction from the rear end portion of the rear side member is efficiently transmitted from the lower back to the joint portion between the lower back having high rigidity and the quarter panel. For this reason, the torsional rigidity of the rear part of the vehicle can be further improved.

  According to the third aspect of the present invention, the lower back is formed between the mating surface with the rear floor and the lower back reinforcement in a longitudinal sectional view from the vehicle width direction inner side end portion of the mating surface with the rear side member. The space between the mating surfaces is substantially the same surface with no offset in the vehicle longitudinal direction. As a result, the load in the vertical direction from the rear end portion of the rear side member is more efficiently transmitted from the lower back to the mating surface of the lower back and the lower back reinforcement. For this reason, the torsional rigidity at the rear of the vehicle can be further improved.

  According to the fourth aspect of the present invention, in the lower back or the lower back reinforcement, the lower back and the lower back reinforcement are arranged in the vehicle upper part from the mating surface of the lower back and the lower back reinforcement, in the longitudinal direction of the vehicle in the longitudinal direction of the vehicle. A vertical wall is formed so as not to be offset. Accordingly, the torsional rigidity of the rear portion of the vehicle can be further improved by transmitting the load in the vertical direction from the mating surface of the lower back and the lower back reinforcement to the vertical wall portion of the upper portion of the vehicle.

  According to the fifth aspect of the present invention, the lower back has no offset in the vehicle front-rear direction between the vehicle width direction inner end of the mating surface with the rear side member and the mating surface with the quarter panel in a cross-sectional view. The upper and lower loads from the rear end of the rear side member are efficiently transmitted from the lower back to the joint portion between the lower back and the quarter panel having high rigidity. For this reason, the torsional rigidity of the rear part of the vehicle can be further improved.

  According to the vehicle rear portion structure relating to the present invention, it is possible to suppress the occurrence of twisting of the vehicle rear portion with respect to the load in the vertical direction inputted through the rear side member.

It is a rear view which shows the vehicle rear part structure which concerns on 1st Embodiment. It is a longitudinal cross-sectional view which shows the vehicle rear part structure along the 2-2 line in FIG. It is a longitudinal cross-sectional view which shows the vehicle rear part structure along line 3-3 in FIG. FIG. 2 is a cross-sectional view showing the vicinity of a quarter panel and a rear side member of the vehicle rear structure shown in FIG. 1. It is a perspective view which shows the lower back panel and lower back reinforcement of the vehicle rear part structure shown in FIG. It is a perspective view which shows the state which attached the side gusset to the vehicle rear part structure shown in FIG. It is a longitudinal cross-sectional view which shows the rear side member vicinity of the vehicle rear part structure which concerns on a 1st comparative example. It is a longitudinal cross-sectional view which shows the vehicle width direction center part vicinity of the rear floor panel of the vehicle rear part structure which concerns on a 1st comparative example. It is a cross-sectional view showing the vicinity of the quarter panel and rear side member of the vehicle rear structure according to the first comparative example. It is a perspective view which shows the lower back panel etc. which are used for the vehicle rear part structure which concerns on a 2nd comparative example.

  Hereinafter, a first embodiment of a vehicle rear structure according to the present invention will be described with reference to FIGS. Note that an arrow RR appropriately shown in these drawings indicates the vehicle rear side, an arrow UP indicates the vehicle upper side, and an arrow OUT indicates the vehicle width direction outer side.

  FIG. 1 is a rear view showing the overall configuration of the vehicle rear structure 11 according to the present embodiment. FIG. 2 is a longitudinal sectional view showing a configuration in the vicinity of the rear side member of the vehicle rear structure 11 taken along line 2-2 in FIG. 1, and FIG. 3 shows a line 3-3 in FIG. A configuration in the vicinity of the center portion in the vehicle width direction of the vehicle rear portion structure 11 along the line is shown in a longitudinal sectional view. As shown in FIG. 2, the rear portion 10A of the vehicle 10 is provided with a rear floor panel 12 as a rear floor extending substantially along the vehicle front-rear direction and the vehicle width direction on the vehicle lower side. A rear side member 14 extending along the vehicle front-rear direction is provided at the lower portion of the rear floor panel 12. As shown in FIGS. 1 and 2, the rear side member 14 is disposed as a pair on the left and right sides of the rear floor panel 12 in the vehicle width direction. The rear side member 14 has a substantially cross-sectional shape in the vehicle width direction, and flange portions (not shown) formed on both sides of the upper vehicle width direction are joined to the lower surface of the rear floor panel 12, thereby The member 14 and the rear floor panel 12 form a closed cross section.

  As shown in FIGS. 1 to 3, on the vehicle rear side of the rear floor panel 12, a lower back panel 16 is disposed as a lower back that extends substantially along the vehicle vertical direction and the vehicle width direction. . In FIG. 1, the lower back panel 16 is indicated by a two-dot chain line for easy understanding of the configuration of the rear portion 10 </ b> A of the vehicle 10.

  A lower back reinforcement that is joined to the lower back panel 16 from the vehicle front side of the lower back panel 16 to form a closed cross section with the lower back panel 16 is formed at the upper portion of the lower back panel 16 at the rear portion 10A of the vehicle 10. 18 is provided (see FIGS. 2 and 3). Further, as shown in FIGS. 1 and 4, the rear portion 10 </ b> A of the vehicle 10 is provided with a quarter panel 20 disposed along the vehicle front-rear direction at both ends in the vehicle width direction on the vehicle front side of the lower back panel 16. It has been.

  As shown in FIGS. 1 to 3, the rear floor panel 12 includes a concave portion 12 </ b> B whose center in the vehicle width direction is recessed toward the vehicle lower side with respect to the end portions 12 </ b> A on both sides in the vehicle width direction when viewed from the rear of the vehicle. (See FIG. 1). A rear end portion of the rear floor panel 12 in the vehicle front-rear direction is formed with a concave portion 12B and a bent portion 12C bent upward from the rear end portion of the end portion 12A on both sides in the vehicle width direction. The bent portion 12C is formed over substantially the entire width of the rear floor panel 12 in the vehicle width direction. The bent portion 12C is disposed in surface contact with the front wall of the lower back panel 16, and the bent portion 12C and the lower back panel 16 are joined by welding (in this embodiment, spot welding).

  As shown in FIG. 1, rear floor side panels 22 as rear floors are disposed on both sides of the rear floor panel 12 in the vehicle width direction. A bent portion 22A bent to the vehicle lower side is formed at the rear end portion of the rear floor side panel 22 in the vehicle front-rear direction. The bent portion 22A is arranged in surface contact with the front wall of the lower back panel 16, and the bent portion 22A and the lower back panel 16 are joined by welding (in this embodiment, spot welding).

  At the rear end portion of the rear side member 14 in the vehicle front-rear direction, there are formed three-direction flange portions 14A and 14B that are bent from the wall portion having a substantially hat-like cross section to the left and right sides and the lower side, respectively ( 2 and 4). The flange portions 14A and 14B are arranged in surface contact with the front wall of the lower back panel 16, and the flange portions 14A and 14B and the lower back panel 16 are joined by welding (in this embodiment, spot welding).

  As shown in FIG. 5, the lower back panel 16 includes a vertical wall portion 16 </ b> A that is disposed in the vehicle width direction central portion along the vehicle width direction and the vehicle vertical direction, and the vehicle wall width direction outside of the vertical wall portion 16 </ b> A. A wall portion 16B extending obliquely outward from the vehicle front side from both ends of the vehicle, and an outer vertical wall portion 16C extending from the outer end portion of the wall portion 16B in the vehicle width direction along the vehicle width direction and the vehicle vertical direction. It is equipped with. The aforementioned flange portions 14A and 14B of the rear side member 14 and the bent portion 22A of the rear floor side panel 22 are joined to the outer vertical wall portion 16C of the lower back panel 16 (see FIG. 1).

  As shown in FIGS. 2, 3 and 5, the lower back panel 16 includes a horizontal wall portion extending from the upper end portions of the vertical wall portion 16A, the wall portion 16B, and the outer vertical wall portion 16C toward the vehicle rear side. 16D, an upper vertical wall portion 16E extending from the rear end portion of the lateral wall portion 16D toward the vehicle upper side, and a bent portion bent from the upper end portion of the upper vertical wall portion 16E to the vehicle upper side or the vehicle rear oblique upper side. Part 16F.

  Further, the lower back panel 16 includes a bent flange portion 16G that is bent in a substantially crank shape from the lower end portions of the vertical wall portion 16A, the wall portion 16B, and the outer vertical wall portion 16C to the vehicle rear side.

  As shown in FIGS. 2 and 3, the lower back reinforcement 18 has a vertical wall portion 18 </ b> A disposed substantially along the vehicle vertical direction, and extends from the upper end portion of the vertical wall portion 18 </ b> A toward the vehicle rear side. And a bent portion 18C bent from the rear end portion of the horizontal wall portion 18B to the vehicle upper side or the vehicle rear oblique upper side. The lower end portion 18D of the vertical wall portion 18A is disposed in surface contact with the vertical wall portion 16A, the wall portion 16B, and the upper end portion of the outer vertical wall portion 16C of the lower back panel 16, and is welded (spot welding in this embodiment). (See FIG. 1). The bent portion 18C of the lower back reinforcement 18 is arranged in surface contact with the bent portion 16F of the lower back panel 16, and is joined by welding (in this embodiment, spot welding). In other words, the upper and lower bent portions 18C and the lower end portion 18D of the lower back reinforcement 18 have the upper bent portion 16F and the lower end front edge of the opening cross section formed by the horizontal wall portion 16D and the upper vertical wall portion 16E of the lower back panel 16. By being coupled to the portion (vertical wall portion), a closed cross section is formed at the upper portion of the lower back panel 16 by the lower back reinforcement 18.

  As shown in FIG. 4, the quarter panel 20 extends substantially along the vehicle vertical direction and the vehicle front-rear direction, and is bent at the rear end portion of the quarter panel 20 in the vehicle width direction inside 20A. It has. The bent portion 20A of the quarter panel 20 is disposed in surface contact with the front wall of the outer vertical wall portion 16C of the lower back panel 16, and the bent portion 20A and the lower back panel 16 are welded (in this embodiment, spot welding). ).

  Here, the vehicle rear portion structure 11 of the present embodiment will be described in more detail. As shown in FIG. 1 and FIG. 2, the lower back panel 16 includes a mating surface (welded surface) between the lower back panel 16 and the flange portions 14 </ b> A and 14 </ b> B of the rear side member 14, and a lower back panel 16. There is provided an outer vertical wall portion 16C as a wall surface portion formed so as to be substantially the same surface with no offset in the longitudinal direction of the vehicle between the mating surface (welded surface) with the lower end portion 18D of the lower back reinforcement 18. Yes. Here, the “offset” is a relative position from a certain point serving as a reference, for example, being deviated in a certain direction from the position serving as the reference point. That is, “no offset” in the present embodiment means that the vehicle is not displaced in the vehicle front-rear direction from the position serving as the reference point.

  In other words, the outer vertical wall portion 16C of the lower back panel 16 allows the upper end of the mating surface of the lower back panel 16 and the flange portions 14A and 14B of the rear side member 14 and the lower back panel 16 and the lower back reinforcement in a longitudinal sectional view. The lower end of the mating surface with the lower end portion 18D of 18 is arranged at substantially the same position in the vehicle front-rear direction. Thus, the load in the vehicle vertical direction (arrows A and B shown in FIG. 1) input from the rear end portion of the rear side member 14 is aligned with the lower back panel 16 having a high rigidity and the lower end portion 18D of the lower back reinforcement 18. It is designed to be transmitted efficiently to the surface.

  As shown in FIGS. 1 and 2, the lower back panel 16 is arranged in the vehicle width direction from the vehicle inner end portion of the mating surface (welded surface) between the lower back panel 16 and the flange portions 14 </ b> A and 14 </ b> B of the rear side member 14. Outside, in a longitudinal sectional view, a mating surface (welded surface) of the lower back panel 16 and the bent portion 12C of the rear floor panel 12 and the bent portion 22A of the rear floor side panel 22, and the lower ends of the lower back panel 16 and the lower back reinforcement 18 The space between the mating surface (welded surface) and the portion 18D is formed to be substantially the same surface with no offset in the vehicle front-rear direction. In other words, the outer vertical wall portion 16C of the lower back panel 16 lowers the lower side in a longitudinal sectional view from the vehicle inner end portion of the mating surface between the lower back panel 16 and the flange portions 14A and 14B of the rear side member 14 in the vehicle width direction outer side. The upper end of the mating surface of the back panel 16 and the bent portion 12C of the rear floor panel 12 and the bent portion 22A of the rear floor side panel 22 and the lower end of the mating surface of the lower back panel 16 and the lower end portion 18D of the lower back reinforcement 18 are They are arranged at substantially the same position in the vehicle longitudinal direction.

  In the present embodiment, as shown in FIG. 1, the vehicle width of the mating surface (welded surface) between the lower back panel 16 and the flange portions 14 </ b> A and 14 </ b> B of the rear side member 14 by the outer vertical wall portion 16 </ b> C of the lower back panel 16. Between the line 26 drawn in the vehicle vertical direction from the inner end of the direction and the mating surface (welded surface) of the lower back panel 16 and the bent portion 20A of the quarter panel 20 is substantially the same surface with no offset in the vehicle longitudinal direction. ing. That is, as shown in FIG. 4, the outer vertical wall portion 16 </ b> C of the lower back panel 16 has a mating surface (welded surface) between the lower back panel 16 and the flange portions 14 </ b> A and 14 </ b> B of the rear side member 14 in a cross sectional view. An inner end portion in the vehicle width direction and an inner end portion of a mating surface (welded surface) between the lower back panel 16 and the bent portion 20A of the quarter panel 20 are disposed at substantially the same position in the vehicle front-rear direction. As a result, the vehicle vertical load input from the rear end portion of the rear side member 14 is efficiently transmitted from the lower back panel 16 to the joint portion between the lower back panel 16 and the quarter panel 20 having high rigidity. Yes.

  In place of this embodiment, for example, even when the bent portion of the rear floor panel 12 and the bent portion of the rear floor side panel 22 extend obliquely with respect to the vehicle vertical direction, A gap between the bent portion of the rear floor panel 12 and the bent portion of the rear floor side panel 22 (welded surface) and the mated surface (welded surface) of the lower back panel 16 and the lower end portion 18D of the lower back reinforcement 18 What is necessary is just to be formed so that it may become substantially the same surface without an offset in the vehicle front-back direction.

  Further, as shown in FIGS. 1 and 3, the lower back panel 16 has a longitudinal section on the inner side in the vehicle width direction (between the pair of left and right rear side members 14) from the vehicle inner end of the joint with the rear side member 14. When viewed, there is a gap between the mating surface (welded surface) of the lower back panel 16 and the bent portion 12C of the rear floor panel 12 and the mating surface (welded surface) of the lower back panel 16 and the lower end portion 18D of the lower back reinforcement 18. A vertical wall portion 16A and a wall portion 16B are formed so as to be substantially on the same plane with no offset in the vehicle longitudinal direction. In other words, the vertical wall portion 16A and the wall portion 16B of the lower back panel 16 allow the upper end of the mating surface of the lower back panel 16 and the bent portion 12C of the rear floor panel 12 and the lower back panel 16 and the lower back reinforcement to be viewed in a vertical sectional view. The lower end of the mating surface with the lower end portion 18D of the ment 18 is disposed at substantially the same position in the vehicle front-rear direction. As a result, the load in the vehicle vertical direction input from the rear end of the rear side member 14 is distributed to the thin lower back panel 16 without stress concentration, and the lower back panel 16 and the lower back reinforcement 18 having a high load rigidity are distributed. Is efficiently transmitted to the mating surface with the lower end 18D.

  In place of this embodiment, for example, even when the bent portion of the rear floor panel 12 extends in an oblique direction with respect to the vehicle vertical direction, the lower back panel 16 and the bent portion of the rear floor panel 12 are viewed in a longitudinal sectional view. The mating surface (welding surface) and the mating surface (welding surface) between the lower back panel 16 and the lower end portion 18D of the lower back reinforcement 18 are formed to be substantially the same surface with no offset in the vehicle longitudinal direction. It only has to be.

  As shown in FIGS. 2 and 3, the lower back reinforcement 18 has a longitudinal section extending from the mating surface (welded surface) between the lower back panel 16 and the lower end portion 18 </ b> D of the lower back reinforcement 18 to the upper part of the vehicle. The vertical wall portion 18A is formed so as not to be offset substantially in the vehicle front-rear direction with respect to the mating surface. Thus, the load is efficiently transmitted from the mating surface between the lower back panel 16 and the lower end portion 18D of the lower back reinforcement 18 to the vertical wall portion 18A at the upper part of the vehicle.

  The thin lower back panel 16 has a stress distribution structure in which vertical, horizontal, and diagonal beads are not set in the vertical wall portion 16A, the wall portion 16B, and the outer vertical wall portion 16C. As a result, the vehicle vertical load input from the rear end of the rear side member 14 is dispersed without concentrating stress on the lower back panel 16.

Moreover, the rigidity of the terminal of the lower back panel 16 is ensured by providing the bending flange part 16G bent in a substantially crank shape at the lower end of the lower back panel 16.
In addition, it may replace with the bending flange part 16G in the lower end of the lower back panel 16, and may provide the outer periphery bead and the rigidity of the terminal of the lower back panel 16 may be ensured.

  Next, the operation and effect of the vehicle rear structure 11 of the present embodiment will be described.

  As shown in FIGS. 1 and 2, the lower back panel 16 includes a mating surface between the lower back panel 16 and the flange portions 14 </ b> A and 14 </ b> B of the rear side member 14, and a lower back panel 16 and a lower back reinforcement in a longitudinal sectional view. The outer vertical wall portion 16C is formed so that the space between the lower end portion 18D of the ment 18 and the mating surface is substantially the same surface with no offset in the vehicle longitudinal direction. Accordingly, the load in the vehicle vertical direction (arrows A and B shown in FIG. 1) input from the rear end portion of the rear side member 14 when the vehicle is traveling, etc., is applied to the lower back panel 16 and the lower back reinforcement 18 having high rigidity. Can be efficiently transmitted to the mating surface with the lower end 18D. That is, the load in the vehicle vertical direction can be transmitted in the shear direction (surface direction of the lower back panel 16) to the mating surface between the lower back panel 16 having high rigidity and the lower end portion 18D of the lower back reinforcement 18. Thereby, even if it is a thin-plate lower back panel 16, the twist of 10 A of rear parts of the vehicle 10 can be suppressed efficiently, without adding components with respect to the load of a vehicle up-down direction, and an increase in board thickness.

  As shown in FIGS. 1 and 2, the lower back panel 16 is disposed on the outer side in the vehicle width direction from the inner end portion in the vehicle width direction of the mating surface between the lower back panel 16 and the flange portions 14 </ b> A and 14 </ b> B of the rear side member 14. In a longitudinal sectional view, the mating surface of the lower back panel 16 and the bent portion 12C of the rear floor panel 12 and the bent portion 22A of the rear floor side panel 22, and the mating surface of the lower back panel 16 and the lower end portion 18D of the lower back reinforcement 18 are shown. Is substantially the same surface with no offset in the vehicle longitudinal direction. That is, as shown in FIG. 1, the vehicle width direction inner end of the mating surface (welded surface) between the lower back panel 16 and the flange portions 14 </ b> A and 14 </ b> B of the rear side member 14 by the outer vertical wall portion 16 </ b> C of the lower back panel 16. The line 26 drawn in the vertical direction of the vehicle and the mating surface of the lower back panel 16 and the bent portion 20A of the quarter panel 20 are substantially the same surface with no offset in the vehicle longitudinal direction. Thus, the vehicle vertical load input from the rear end of the rear side member 14 can be efficiently transmitted from the lower back panel 16 to the joint between the lower back panel 16 and the quarter panel 20 having high rigidity. That is, the torsional rigidity of the rear portion 10A of the vehicle 10 is further improved by transmitting the load in the vehicle vertical direction from the lower back panel 16 to the joint portion between the lower back panel 16 and the quarter panel 20 having high rigidity in the shear direction. be able to.

  1 and 3, the lower back panel 16 includes a pair of left and right rear side members 14 and a mating surface between the lower back panel 16 and the bent portion 12C of the rear floor panel 12 in a longitudinal sectional view. The vertical wall portion 16A and the wall portion 16B are formed so that the gap between the lower back panel 16 and the mating surface of the lower end portion 18D of the lower back reinforcement 18 is substantially the same surface with no offset in the vehicle longitudinal direction. Yes. As a result, the vehicle vertical direction load input from the rear end portion of the rear side member 14 can be more efficiently transmitted to the mating surface between the lower back panel 16 having high rigidity and the lower end portion 18D of the lower back reinforcement 18. it can. Thereby, the torsional rigidity of the rear portion 10A of the vehicle 10 can be further improved.

  Further, as shown in FIGS. 2 and 3, the lower back reinforcement 18 has a mating surface in a longitudinal sectional view from the mating surface of the lower back panel 16 and the lower end portion 18 </ b> D of the lower back reinforcement 18 to the upper part of the vehicle. The vertical wall portion 18A is formed so as not to be offset substantially in the vehicle longitudinal direction. Thereby, the rigidity in the vertical direction of the mating surface between the lower back panel 16 and the lower end portion 18D of the lower back reinforcement 18 is further increased, and the vehicle is more effective than the mating surface between the lower back panel 16 and the lower end portion 18D of the lower back reinforcement 18. A load can be efficiently transmitted to the upper vertical wall portion 18A. That is, the torsional rigidity of the rear portion 10A of the vehicle 10 can be further improved by transmitting the load in the vehicle vertical direction from the lower back panel 16 to the vertical wall portion 18A of the lower back reinforcement 18 in the shear direction.

  Furthermore, the thin lower back panel 16 has a stress distribution structure in which vertical, horizontal, and diagonal beads are not set in the vertical wall portion 16A, the wall portion 16B, and the outer vertical wall portion 16C. As a result, the vehicle vertical load input from the rear end portion of the rear side member 14 is dispersed without concentrating the stress on the lower back panel 16, and the lower back panel 16 and the lower back reinforcement 18 having high rigidity in a wide range are distributed. The load can be transmitted to the mating surface with the lower end 18D and the joint between the lower back panel 16 and the quarter panel 20. Thereby, the high torsional rigidity of the rear portion 10A of the vehicle 10 can be ensured.

  A general lower back structure of an automobile includes a lower back panel and a lower back reinforcement, a back door opening is formed in a closed cross section, and a lower extension thereof is a thin plate structure of one lower back panel. . Therefore, it is necessary to increase the rigidity of the lower back panel with respect to the input from the rear side member. For example, the rigidity is increased by increasing the thickness of the lower back panel, adding another member such as a side gusset or center gusset to the lower back panel, and further increasing the thickness of the other member. . In addition, in order to reduce the weight of the lower back panel, vertical bead and horizontal bead are set on the lower back panel, and measures to increase rigidity and strength are incorporated.

  However, increasing the plate thickness of the lower back panel, adding another member to the lower back panel, and increasing the plate thickness of another member further increase the weight of the vehicle and increase the cost. End up. In order to improve fuel economy and steering stability, it is desirable to improve rigidity at a light weight and low cost.

  In the vehicle rear structure 11 of the present embodiment, the plate thickness of the lower back panel 16 and the lower back reinforcement 18 can be reduced, and the separate parts (side gusset, center gusset) are eliminated or the plate thickness of the separate parts is reduced. be able to. Thereby, weight reduction and cost reduction are realizable.

  FIG. 6 shows an example in which side gussets are provided in the vehicle rear structure 11 of the present embodiment. As shown in FIG. 6, a substantially planar side gusset 30 is disposed on the vehicle rear side of the outer vertical wall portion 16 </ b> C of the lower back panel 16. The side gusset 30 is disposed in surface contact with the outer vertical wall portion 16C, and the side gusset 30 and the outer vertical wall portion 16C are joined by welding (spot welding). That is, in the vehicle rear portion structure 11 of the present embodiment, the platform can be unified in a structure in which the welding surface of the side gusset 30 is substantially the same surface with no offset in the vehicle front-rear direction in a longitudinal sectional view. For this reason, the shape of the side gusset designed for each vehicle can be shared. As a result, the mold cost of the side gusset 30 can be reduced, facilities for assembling the lower back panel 16 can be simplified, and further cost reduction can be achieved.

  Further, the vehicle rear structure of the present embodiment makes it easy to mold each part and form a mating surface, making it easy to manufacture and reducing processing costs.

  7 to 9 show the vehicle rear structure 101 of the first comparative example. As shown in FIGS. 7 and 8, a lower back panel 102 is provided at the rear end portion of the rear floor panel 12 and the rear side member 14 in the rear portion 100 </ b> A of the vehicle 100. The lower back panel 102 is disposed substantially along the vertical direction of the vehicle and has a vertical wall portion 102A to which the rear end portions of the rear floor panel 12 and the rear side member 14 are joined, and an obliquely upward rearward direction of the vehicle from the upper end portion of the vertical wall portion 102A. An inclined portion 102B extending toward the side, and an upper vertical wall portion 102C extending substantially upward from the upper end portion of the inclined portion 102B.

  The lower back reinforcement 104 includes a joining portion 104A joined to the upper vertical wall portion 102C, a lateral wall portion 104B extending from the upper end portion of the joining portion 104A toward the vehicle front side, and a vehicle upper side from the front end portion of the lateral wall portion 104B. And a vertical wall portion 104C extending toward the side. Further, the lower back reinforcement 104 includes a horizontal wall portion 18B extending from the upper end portion of the vertical wall portion 104C toward the vehicle rear side, and a bent portion 16F of the lower back panel 102 formed at the rear end portion of the horizontal wall portion 18B. And a bent portion 18C to be joined.

  As shown in FIG. 9, the lower back panel 102 includes an inclined portion 102D extending from the vehicle width direction outer side end portion of the vertical wall portion 102A toward the vehicle front diagonally outer side, and a vehicle width direction outer end portion of the inclined portion 102D. And a bent portion 102E that is bent outward in the vehicle width direction and joined to the bent portion 20A of the quarter panel 20.

  In the vehicle rear structure 101, as shown in FIG. 7, the lower back panel 102 is in a longitudinal sectional view with respect to a mating surface (welded surface) between the lower back panel 102 and the flange portions 14A and 14B of the rear side member 14. The mating surface (welded surface) between the lower back panel 102 and the joint 104A of the lower back reinforcement 104 is offset to the vehicle rear side by the inclined portion 102B.

  As shown in FIG. 8, the lower back panel 102 is between the pair of left and right rear side members 14 with respect to a mating surface (welded surface) between the lower back panel 102 and the bent portion 12 </ b> C of the rear floor panel 12 in a longitudinal sectional view. Thus, the mating surface (welded surface) between the lower back panel 102 and the joint 104A of the lower back reinforcement 104 is offset to the vehicle rear side by the inclined portion 102B.

  As shown in FIG. 9, the mating surface of the lower back panel 102 and the bent portion 20 </ b> A of the quarter panel 20 with respect to the mating surface (welded surface) of the lower back panel 102 and the flange portions 14 </ b> A and 14 </ b> B of the rear side member 14. (Welding surface) is offset to the vehicle front side by the inclined portion 102D.

  In such a vehicle rear structure 101, the vehicle vertical load input through the rear side member 14 during vehicle travel is applied to the mating surface of the lower back panel 102 and the joint 104A of the lower back reinforcement 104, or the lower back panel. It is difficult to efficiently transmit to the mating surface between 102 and the bent portion 20A of the quarter panel 20. For this reason, there is a possibility that displacement in the vertical direction occurs at the rear end portion of the rear side member 14 and the rigidity is lowered.

  On the other hand, in the vehicle rear structure 11 according to the present embodiment, the lower and upper ends of the lower back panel 16 and the lower back reinforcement 18 are provided with a load in the vehicle vertical direction that is input via the rear side member 14 when the vehicle is traveling. It can be efficiently transmitted to the mating surface with 18D and the junction with the quarter panel 20. For this reason, the vertical displacement of the rear end portion of the rear side member 14 can be suppressed, and the high torsional rigidity of the rear portion 10A of the vehicle 10 can be ensured.

  FIG. 10 shows a vehicle rear portion structure 121 of the second comparative example. As shown in FIG. 10, a lower back panel 122 is provided at the rear end portion of the rear floor panel 12 and the rear side member 14 (see FIG. 7, etc.) at the rear portion 120 </ b> A of the vehicle 120. A plurality of beads 122A extending substantially in the vehicle vertical direction are formed on the vertical wall portion 16A at the center in the vehicle width direction of the lower back panel 122 and the wall portions 16B on both sides in the vehicle width direction of the vertical wall portion 16A. The bead 122A is formed so as to protrude in a convex shape toward the vehicle rear side. The plurality of beads 122A are arranged substantially parallel to the vehicle width direction.

  In such a vehicle rear structure 121, by forming a plurality of beads 122 </ b> A on the lower back panel 122, the rigidity of the lower back panel 122 itself is increased, but the vehicle vertical direction load input through the rear side member 14 is increased. It is difficult to disperse the lower back panel 122 without stress concentration.

  On the other hand, in the vehicle rear portion structure 11 of the present embodiment, no beads (vertical, horizontal, oblique directions) are set in the vertical wall portion 16A, the wall portion 16B, and the outer vertical wall portion 16C of the lower back panel 16. The load in the vertical direction of the vehicle input via the rear side member 14 is dispersed without concentrating the stress on the lower back panel 16, and the lower back panel 16 having a wide range and the lower end 18D of the lower back reinforcement 18 Thus, the load can be transmitted to the mating surface or the joint between the lower back panel 16 and the quarter panel 20.

  In the vehicle rear structure 11 of the present embodiment, the lower back reinforcement 18 is provided on the front side of the vehicle above the lower back panel 16, but the lower back reinforcement is provided on the rear side of the vehicle above the lower back panel. Also good. In this case, the lower back panel is provided with a vertical wall portion formed so as not to be offset in the vehicle front-rear direction with respect to the mating surface in a longitudinal sectional view from the mating surface of the lower back panel and the lower back reinforcement. It is preferable to provide.

  Moreover, although the vehicle rear part structure 11 of this embodiment is provided with all the five patterns of structures shown in FIGS. 1 to 4, it is not limited to this. For example, the lower back panel 16 may have a structure including any one or more of five patterns, but the lower back panel 16 includes a mating surface between the lower back panel 16 and the flange portions 14A and 14B of the rear side member 14, and a lower It is preferable that the space between the back panel 16 and the mating surface of the lower end portion 18D of the lower back reinforcement 18 is substantially the same surface with no offset in the vehicle longitudinal direction. Further, for example, a structure in which any two or more patterns are combined among the five patterns of structures may be used.

10 vehicle 10A rear part 11 vehicle rear part structure 12 rear floor panel (rear floor)
12C Bend (Mating surface with lower back)
14 Rear side members 14A, 14B Flange (mating surface with lower back)
16 Lower back panel (lower back)
16C Outside vertical wall (wall surface)
18 Lower back reinforcement 18A Vertical wall 18D Lower end (mating surface with lower back)
20 Quarter panel 20A Bent part (rear end)
22 Rear floor side panel (rear floor)
22A Bent part (mating surface with lower back)

Claims (5)

A rear floor provided at the rear of the vehicle and extending along the vehicle longitudinal direction and the vehicle width direction;
A pair of rear side members disposed on both sides of the rear floor in the vehicle width direction and extending along the vehicle longitudinal direction;
A lower back that extends from the rear end of the rear floor in the vehicle front-rear direction toward the vehicle upper side and to which the rear end of the rear side member in the vehicle front-rear direction is joined.
A lower back reinforcement which is disposed on an upper portion of the lower back and forms a closed cross-section with the lower back;
A quarter panel provided at both ends in the vehicle width direction of the rear portion of the vehicle and extending along the vehicle front-rear direction, the rear end portion being joined to the vehicle width direction end portion of the lower back;
A wall surface portion provided in the lower back and formed so that a gap between the mating surface with the rear side member and the mating surface with the lower back reinforcement is substantially the same surface with no offset in the vehicle front-rear direction in a longitudinal sectional view. When,
A vehicle rear structure having:   The lower back is positioned between the mating surface with the rear floor and the mating surface with the lower back reinforcement in a longitudinal sectional view from the vehicle width direction inner end of the mating surface with the rear side member in the vehicle width direction outer side. The vehicle rear portion structure according to claim 1, wherein the vehicle rear portion structure is formed so as to be substantially on the same plane without offset in the front-rear direction.   The lower back is located on the vehicle width direction inner side end of the mating surface with the rear side member from the inner side in the vehicle width direction, and is between the mating surface with the rear floor and the mating surface with the lower back reinforcement in a longitudinal sectional view. The vehicle rear portion structure according to claim 1 or 2, wherein the vehicle rear portion structure is formed so as to be substantially on the same plane with no offset in the front-rear direction.   The lower back, or the lower back reinforcement, is a vertical portion formed in the vehicle upper portion from the mating surface of the lower back and the lower back reinforcement so as not to be offset in the vehicle front-rear direction with respect to the mating surface in a longitudinal sectional view. The vehicle rear portion structure according to any one of claims 1 to 3, further comprising a wall portion.   The lower back is formed so that a gap between the inner end of the mating surface with the rear side member in the cross-sectional view and the mating surface with the quarter panel is substantially the same surface with no offset in the vehicle front-rear direction. The vehicle rear portion structure according to any one of claims 1 to 4, wherein the vehicle rear portion structure is provided.

Images