Rear body structure

Abstract

This invention improves handling stability and ride comfort through efficient transmission of a load, inputted to a rear side member, to an overall vehicle body rear structure.　A brace 18 is provided inclined so as to be displaced to the outer side in a vehicle width direction towards the vehicle rear in plan view. A front fixation unit 26 of the brace 18 is overlaid onto and fixed to a rear floor panel 12 and a rear side member 10. A rear fixation unit 28 is fixed to a lower gate 14 at a location further outward in the vehicle width direction than the rear side member 10. When a load is inputted from a coil spring to the rear side member 10, the load is transmitted from the rear side member 10 to a location more to the outer side of the lower gate 14, in the vehicle-width-direction thereof, than the rear side member 10, said load being transmitted through the rear floor panel 12 and a pair of braces 18.

Description

Technical Field

[0001] The present invention relates to a rear body structure.

Background Art

[0002] In a rear body structure including a pair of rear side members, a rear floor panel provided above the rear side members, a gate lower extending in the vehicle width direction at the rear end of the rear floor panel, and gate pillars extending upward from both ends of the gate lower, a structure in which the upper part of the rear side member and the gate lower are connected by a brace is disclosed (see Patent Document 1).

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In such a rear body structure, when the rear side member supports the upper end of the coil spring that constitutes the suspension device, efficiently transmitting the load input from the coil spring to the entire rear body structure (body skeleton) is advantageous for ensuring the vehicle's handling stability and ride comfort. However, in the above prior art, the load input from the coil spring is transmitted in a form orthogonal to the gate lower from the rear side member via the brace. Therefore, some improvement is required to efficiently transmit the load to the entire rear body structure. The present invention has been made in view of the above circumstances, and an object thereof is to provide a rear body structure that is advantageous for improving handling stability and ride comfort by efficiently transmitting the load input to the rear side member to the entire rear body structure.

Means for Solving the Problems

[0005] To achieve the above objective, one embodiment of the present invention provides a rear body structure for a vehicle comprising: a pair of rear side members extending in the vehicle longitudinal direction at intervals in the vehicle width direction; a rear floor panel provided on the upper part of the rear side members; a gate lower extending in the vehicle width direction from the rear end of the rear floor panel and constituting the lower edge of a gate opening provided at the rear end of the vehicle; a pair of gate pillars extending upward from both ends of the gate lower and constituting the side edges of the gate opening; and a pair of braces extending in the vehicle longitudinal direction and connecting each of the pair of side members to the gate lower, wherein the front end of the brace is a front fixing part that is superimposed and fixed to the floor panel and the side member, the upper part of the brace is a rear fixing part that is superimposed and fixed to the gate lower, and the brace is provided inclined so as to be displaced outward in the vehicle width direction as it approaches the rear of the vehicle in a plan view, and the rear fixing part is fixed to the gate lower at a position outward in the vehicle width direction from the rear side member. [Effects of the Invention]

[0006] According to one embodiment of the present invention, for example, when a load is applied from a coil spring to the rear side member, the load is transmitted from the rear side member to a location on the outer side in the vehicle width direction of the gate lower via the rear floor panel and a pair of braces. Since the outer edge of the lower gate in the vehicle width direction is close to the lower end of the pair of gate pillars, the load is efficiently transmitted from the lower gate to the pair of gate pillars. Therefore, this is advantageous in efficiently transferring the load to the entire rear structure of the vehicle, and is beneficial in improving handling stability and ride comfort. [Brief explanation of the drawing]

[0007] [Figure 1] This is a perspective view of the rear body structure according to the embodiment, as seen from inside the vehicle body. [Figure 2]This is a perspective view of the rear vehicle structure according to the embodiment, as seen from the front of the vehicle. [Figure 3] This is a perspective view of the main part of the rear body structure according to the embodiment, as seen from the front of the vehicle. [Figure 4] This is a plan view of the main part of the rear structure of the vehicle body according to the embodiment. [Figure 5] This is a plan view of the brace. [Figure 6] This is a perspective view of the brace from the front. [Figure 7] This is a perspective view of the brace from the rear. [Figure 8] This is a perspective view of the bulkhead from a diagonal front angle. [Figure 9] This is a perspective view of the bulkhead, seen from almost the opposite direction to Figure 8. [Modes for carrying out the invention]

[0008] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following diagrams, the symbol FR indicates the front of the vehicle, the symbol UP indicates the top of the vehicle, the symbol IN indicates the inside in the vehicle width direction, and the symbol OUT indicates the outside in the vehicle width direction. As shown in Figures 1 and 2, the rear body structure of this embodiment is composed of a pair of rear side members 10, a rear floor panel 12, a gate lower 14, a pair of gate pillars 16, a pair of braces 18, and a pair of bulkheads 20 (see Figures 3 and 4).

[0009] The pair of rear side members 10 are spaced apart in the vehicle width direction and extend in the vehicle longitudinal direction. As shown in Figure 3, the rear side member 10 comprises a bottom wall 1002 and a pair of vertical walls 1004 erected upward from both sides of the bottom wall 1002 in the vehicle width direction, with flange portions 1010 protruding in the vehicle width direction provided at the upper ends of each pair of vertical walls 1004. Each rear side member 10 is joined to the rear floor panel 12 by overlapping each flange portion 1010 with the rear floor panel 12, thereby forming a closed cross-sectional structure between it and the rear floor panel 12. In other words, the rear side member 10 has a pair of flange portions 1010 provided on the outer and inner sides in the vehicle width direction along the extending direction of the rear side member 10 and joined to the rear floor panel 12. A spring seat (not shown) is provided on the bottom wall 1002 of each rear side member 10, and the upper ends of coil springs of a rear wheel suspension device (for example, a torsion beam type suspension device), both not shown, are supported via the spring seat. Therefore, a load is input to the rear side member 10 from the coil spring.

[0010] As shown in FIGS. 1 and 2, the rear floor panel 12 is provided above the rear side member 10 and extends in the vehicle front-rear direction and the vehicle width direction. Reference numeral 22 in the figure indicates a rear panel that extends in the vertical direction and the vehicle width direction between the rear end of the rear floor panel 12 and the gate lower 14.

[0011] As shown in FIGS. 1 and 2, the gate lower 14 and the pair of gate pillars 16 form a gate opening 24 provided at the rear end of the vehicle. The gate lower 14 extends in the vehicle width direction at the rear end of the rear floor panel 12 and constitutes the lower edge portion of the gate opening 24. The gate lower 14 includes a straight portion 14A extending in the vehicle width direction and a pair of curved portions 14B that curve upward as they extend outward in the vehicle width direction from both ends of the straight portion 14A. As shown in FIG. 1, the gate lower 14 has a closed cross-section structure including a bottom wall 1402 extending in the vehicle width direction, a front wall 1404 and a rear wall 1406 standing up from the front and rear of the bottom wall 1402, and an upper wall 1408 connecting the upper ends of the front wall 1404 and the rear wall 1406.

[0012] As shown in FIGS. 1 and 2, the pair of gate pillars 16 extend upward from both ends of the gate lower 14 and constitute the side edge portions of the gate opening 24. Specifically, the pair of gate pillars 16 are connected to the curved portions 14B on both sides of the gate lower 14 and extend upward from the curved portions 14B. As shown in FIG. 2, the gate pillar 16 includes a front wall 1602 extending in the vertical direction, a rear wall 1604 facing the front wall 1602, an outer wall 1606 connecting the outer sides in the vehicle width direction of the front wall 1602 and the rear wall 1604, and an inner wall 1608 connecting the inner sides in the vehicle width direction of the front wall 1602 and the rear wall 1604, presenting a closed cross-sectional structure.

[0013] A pair of braces 18 extend in the vehicle front-rear direction and connect each of the pair of rear side members 10 and the gate lower 14. As shown in FIGS. 1 and 3, the brace 18 is composed of a front fixing portion 26 and a rear fixing portion 28. The front fixing portion 26 is formed at the front end of the brace 18 and is a portion fixed by overlapping the rear floor panel 12 and the rear side member 10. The rear fixing portion 28 is formed at the upper part of the brace 18 and is a portion fixed by overlapping the gate lower 14. Specifically, it is a portion fixed by overlapping the front wall 1404 of the curved portion 14B of the gate lower 14. As shown in FIGS. 5-7, the brace 18 has a length extending from the front fixing portion 26 toward the rear fixing portion 28 and a width orthogonal to the length. As shown in FIGS. 3 and 4, the brace 18 (in the length direction of the brace 18) is provided to be inclined outward in the vehicle width direction as it reaches the rear in plan view, and the rear fixing portion 28 is fixed to the gate lower 14 at a position outside the vehicle width direction of the rear side member 10. Specifically described, as shown in FIG. 4, the front fixing portion 26 includes an inner front fixing portion 26A located inside the vehicle width direction in the width direction of the brace 18 and an outer front fixing portion 26B located outside the vehicle width direction in the width direction of the brace 18. And the inner front fixing portion 26A is located behind the outer front fixing portion 26B.

[0014] As shown in FIGS. 5-7, bolt insertion holes 2602 and 2604 are provided in the inner front fixing portion 26A and the outer front fixing portion 26B, respectively. As shown in Figures 3 and 4, the inner front fixing portion 26A and the outer front fixing portion 26B are superimposed on the rear floor panel 12 and fixed in a triple-layer configuration to the rear floor panel 12 and the flange portion 1010 of the rear side member 10 by bolts B inserted through the respective bolt insertion holes 2602 and 2604. In other words, the inner front fixing portion 26A is connected to the flange portion 1010 on the inner side in the vehicle width direction, and the outer front fixing portion 26B is connected to the flange portion 1010 on the outer side in the vehicle width direction.

[0015] Furthermore, one bolt insertion hole 2802 is provided in the rear fixing portion 28, closer to the outer side in the vehicle width direction, and two bolt insertion holes 2804 and 2806 are provided in the rear fixing portion 28, closer to the inner side in the vehicle width direction, spaced apart along the length of the brace 18. Therefore, as shown in Figures 3 and 4, the portion of the rear fixing portion 28 that is closer to the outer side in the vehicle width direction is superimposed on the front wall 1404 of the curved portion 14B of the gate lower 14, and is fixed to the gate lower 14 in a double-layered manner by bolts B inserted through bolt insertion holes 2802. Furthermore, the portion of the rear fixing part 28 closer to the inside in the vehicle width direction is superimposed on the front wall 1404 of the curved portion 14B of the gate lower 14, and the gate lower 14 and the front part of the bulkhead 20 (described later) are fixed in a triple layer by bolts B inserted through two bolt insertion holes 2804 and 2806. Here, the two bolt insertion holes 2804 and 2806 constitute an inner rear fixing portion located on the inside in the vehicle width direction in the width direction of the brace 18, and the one bolt insertion hole 2802 constitutes an outer rear fixing portion located on the outside in the vehicle width direction in the width direction of the brace 18. In other words, the rear fixing portion 28 includes inner rear fixing portions 2804 and 2806 and outer rear fixing portion 2802, as shown in Figures 3, 4, 6, and 7. The bulkhead 20 is connected to the brace 18 only at the inner rear fixing points 2804 and 2806.

[0016] As shown in Figures 5-7, both sides of the brace 18 in the width direction are flange portions 1802, and the portion between the flange portions 1802 is a main body portion 1804 that bulges out in one direction in the thickness direction of the brace 18 compared to the flange portions 1802. The cross-section obtained by cutting the brace 18 along the width direction has a hat shape, ensuring the strength and rigidity of the brace 18. Furthermore, since multiple beads 1806 are formed extending along the length of the brace 18 on the main body portion 1804, it is more advantageous in ensuring the strength and rigidity of the brace 18.

[0017] The bulkheads 20 shown in Figures 3 and 4 are provided inside the gate lower 14, on both sides of the gate lower 14 in the vehicle width direction, so as to close off the cross-section of the gate lower 14. The bulkhead 20 is a reinforcing member that reinforces the gate lower 14, and is plate-shaped, installed inside the curved portion 14B of the gate lower 14, and covers the cross-section of the gate lower 14. As shown in Figures 8 and 9, the bulkhead 20 includes a main plate portion 2002 that extends across the bottom wall 1402, top wall 1408, front wall 1404, and rear wall 1406 of the curved portion 14B of the gate lower 14, a front mounting piece 2004 that rises from the front edge of the main plate portion 2002, an upper mounting piece 2006 that is continuous with the front mounting piece 2004 and rises from the upper edge of the main plate portion 2002, and a rear mounting piece 2008 that rises from the rear edge of the main plate portion 2002 in the opposite direction to the front mounting piece 2004 and the upper mounting piece 2006. The front mounting piece 2004 is located at the front of the bulkhead 20 in the longitudinal direction of the vehicle. The front mounting piece 2004 has two bolt insertion holes 2010 and 2012 spaced apart in the vertical direction, and these two bolt insertion holes 2010 and 2012 correspond to two bolt insertion holes 2804 and 2806 (inner rear fixing parts 2804 and 2806) of the rear fixing part 28 that are located closer to the inside in the vehicle width direction.

[0018] As shown in Figures 3 and 4, the front mounting piece 2004 is joined to the front wall 1404 of the curved portion 14B of the gate lower 14 and the rear fixing portion 28 of the brace 18 by overlapping them. The rear fixing portion 28 of the brace 18, the front wall 1404 of the curved portion 14B of the gate lower 14, and the front mounting piece 2004 of the bulkhead 20 are fixed together in a triple-layer configuration by bolts B inserted through the two bolt insertion holes 2804 and 2806 (inner rear fixing portion 2804 and 2806) of the rear fixing portion 28 and the two bolt insertion holes 2010 and 2012 of the front mounting piece 2004. In other words, in the longitudinal direction of the vehicle, the front part of the bulkhead 20 is connected to the rear fixing part 28 of the brace 18, with the gate lower 14 in between. Furthermore, the upper mounting piece 2006 of the bulkhead 20 is welded to the upper wall 1408 of the curved portion 14B of the gate lower 14, and the rear mounting piece 2008 of the bulkhead 20 is welded to the rear wall 1406 of the curved portion 14B of the gate lower 14. As shown in Figure 4, the bulkhead 20 is inclined so as to be displaced inward in the vehicle width direction as it approaches the rear of the vehicle in a plan view.

[0019] Next, I will explain the effects and benefits. According to this embodiment, the brace 18 is provided at an angle such that, in a plan view, it is displaced outward in the vehicle width direction as it approaches the rear of the vehicle. The front fixing portion 26 of the brace 18 is fixed to the rear floor panel 12 and the rear side member 10 in overlapping position, and the rear fixing portion 28 is fixed to the gate lower 14 at a position where the rear fixing portion 28 is outward in the vehicle width direction from the rear side member 10. Therefore, when a load is applied from the coil spring to the rear side member 10, that load is transmitted from the rear side member 10 to the gate lower 14 on the outer side in the vehicle width direction via the rear floor panel 12 and the pair of braces 18. Since the outer edges of the gate lower 14 in the vehicle width direction are close to the lower ends of the pair of gate pillars 16, the load is efficiently transmitted from the gate lower 14 to the pair of gate pillars 16. Therefore, this is advantageous in efficiently transferring the load to the entire rear structure of the vehicle, and is beneficial in improving handling stability and ride comfort.

[0020] Furthermore, in this embodiment, since the rear fixing portions 28 of the pair of braces 18 are fixed to the curved portions 14B located at both ends in the longitudinal direction of the gate lower 14, the rear fixing portions 28 of the pair of braces 18 can be brought closer to the lower ends of the pair of gate pillars 16. This is advantageous in efficiently transmitting the load applied to the rear side member 10 from the gate lower 14 to the gate pillars 16 via the braces 18. Therefore, this is advantageous in efficiently transferring the load to the entire rear structure of the vehicle, and is advantageous in improving handling stability and ride comfort.

[0021] Furthermore, in this embodiment, the length of the brace 18 is inclined outward in the vehicle width direction as it approaches the rear of the vehicle in a plan view. This makes the brace 18 more easily deformed by the collision load applied during a rear-end collision, which reduces the obstruction of the crushable effect and is advantageous in improving the energy absorption efficiency during a rear-end collision.

[0022] Furthermore, in this embodiment, the inner front fixing portion 26A of the brace 18 is located further back than the outer front fixing portion 26B, which is advantageous in ensuring a large gap between the inner front fixing portion 26A and the outer front fixing portion 26B. Therefore, when viewed from above, a large area can be secured where the front fixing portion 26 of the brace 18 overlaps with the rear side member 10, which is advantageous in improving the mounting rigidity of the front fixing portion 26 of the brace 18. Therefore, it is advantageous not only for efficiently transmitting the load applied to the rear side member 10 to the pair of gate pillars 16 from the gate lower 14 via the pair of braces 18, but also for suppressing the deformation of the gate pillars 16 that causes them to tilt forward when the vehicle body undergoes torsional deformation. In other words, it is advantageous for improving the torsional rigidity of the vehicle body, which in turn is advantageous for improving handling stability and ride comfort.

[0023] Furthermore, in this embodiment, the front portion of the bulkhead 20, which is a reinforcing member of the gate lower 14 and is provided on both sides of the gate lower 14 in the vehicle width direction inside the gate lower 14, is connected to the rear fixing portion 28 of the brace 18, sandwiching the gate lower 14 in the vehicle longitudinal direction. Therefore, since the brace 18 is more easily deformed by the collision load applied during a rear-end collision, the obstruction of the crushable effect during a rear-end collision can be reduced, which is even more advantageous in improving the energy absorption efficiency during a rear-end collision.

[0024] Furthermore, in this embodiment, the bulkhead 20 is provided inclined so as to be displaced inward in the vehicle width direction as it approaches the rear of the vehicle in a plan view. Therefore, in addition to the brace 18 being more easily deformed by the collision load applied during a rear-end collision, the bulkhead 20 is also more easily deformed, which further reduces the obstruction of the crushable effect during a rear-end collision and is even more advantageous in improving the energy absorption efficiency during a rear-end collision.

[0025] Furthermore, in this embodiment, the rear fixing portion 28 includes inner rear fixing portions 2804 and 2806 located on the inside in the vehicle width direction in the width direction of the brace 18, and outer rear fixing portion 2802 located on the outside in the vehicle width direction in the width direction of the brace 18, and the bulkhead 20 is connected to the brace 18 only to the inner rear fixing portions 2804 and 2806. Therefore, compared to the case where the bulkhead 20 is fixed to the brace 18 by both the outer rear fixing part 2802 and the inner rear fixing parts 2804 and 2806, the bulkhead 20 is more easily deformed by the collision load applied during a rear collision of the vehicle, which is even more advantageous in enhancing the energy absorption effect during a rear collision of the vehicle. [Explanation of symbols]

[0026] 10 Rear side member 1002 Bottom wall 1004 A pair of vertical walls 1010 Flange 12 Rear floor panel 14 Gate Roar 14A Straight section 14B Curved section 1402 Bottom wall 1404 Front wall 1406 Back wall 1408 Upper wall 16 Gate Pillar 1602 Front wall 1604 Back wall 1606 Exterior Wall 1608 Interior wall 18 Brace 1802 Flange section 1804 Main body 1806 Bead 20 bulkhead 2002 Main body panel 2004 Front mounting piece 2006 Upper mounting piece 2008 Rear mounting piece 2010, 2012 Bolt insertion holes 22 Rear Panel 24 Gate opening 26 Front fixation part 26A Medial front fixation part 26B Outer front fixation part 2602, 2604 Bolt insertion holes 28 Rear fixing part 2804, 2806 Bolt insertion holes (inner rear fixing part) 2802 Bolt insertion hole (outer rear fixing part) B bolt

Claims

1. A rear body structure of a vehicle comprising: a pair of rear side members extending in the vehicle longitudinal direction with a gap in the vehicle width direction; a rear floor panel provided on the upper part of the rear side members; a gate lower extending in the vehicle width direction from the rear end of the rear floor panel and forming the lower edge of a gate opening provided at the rear end of the vehicle; a pair of gate pillars extending upward from both ends of the gate lower and forming the side edges of the gate opening; and a pair of braces extending in the vehicle longitudinal direction and connecting each of the pair of side members to the gate lower, The front end of the brace is a front fixing portion that is fixed to the floor panel and the side member by overlapping them. The upper part of the brace is a rear fixing part that is superimposed on and fixed to the gate lower. The brace is provided at an angle such that, in a plan view, it is displaced outward in the vehicle width direction as it approaches the rear of the vehicle, and the rear fixing portion is fixed to the gate lower at a position outward in the vehicle width direction from the rear side member. A rear body structure characterized by the following.

2. The gate lower comprises a straight section extending in the vehicle width direction and a pair of curved sections that curve upward from both ends of the straight section outward in the vehicle width direction and connect to the lower end of the gate pillar. The aforementioned rear fixing portion is fixed to the curved portion. The rear body structure of the vehicle according to claim 1, characterized in that it is as described above.

3. The rear side member has a pair of flange portions provided on the outer and inner sides in the vehicle width direction along the extending direction of the rear side member, which are joined to the rear floor panel. The front fixing portion includes an inner front fixing portion located on the inside in the vehicle width direction in the width direction of the brace and connected to the flange portion on the inside in the vehicle width direction, and an outer front fixing portion located on the outside in the vehicle width direction in the width direction of the brace and connected to the flange portion on the outside in the vehicle width direction. The inner front fixing portion is positioned rearward of the outer front fixing portion. The rear body structure of the vehicle according to claim 2, characterized by its features.

4. The gate lower has a closed cross-sectional structure, Inside the gate lower, bulkheads are provided on both sides of the gate lower in the vehicle width direction, respectively, to close the cross-section of the gate lower. In the longitudinal direction of the vehicle, the front portion of the bulkhead is connected to the rear fixing portion of the brace, with the gate lower in between. The rear body structure of a vehicle according to any one of claims 1 to 3.

5. The bulkhead is provided in a plan view, inclined so as to displace inward in the vehicle width direction as it approaches the rear of the vehicle. The rear body structure of the vehicle according to feature 4.

6. The rear fixing portion includes an inner rear fixing portion located on the inside in the vehicle width direction in the width direction of the brace, and an outer rear fixing portion located on the outside in the vehicle width direction in the width direction of the brace. The bulkhead is connected to the brace only at the inner rear fixing portion. The rear body structure of the vehicle according to claim 5, characterized in that it is as described above.

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