JP7501199B2 - Vehicle rear body structure - Google Patents

Description

This disclosure relates to a rear body structure of a vehicle.

In a vehicle rear body structure that includes a rear end panel that extends in the vehicle width direction below the rear gate opening formed at the rear end of the vehicle body, and a rear side member that is connected to the rear end panel at its rear end and extends in the fore-and-aft direction of the vehicle body, a strength reinforcing member is provided at the joint between the rear end panel and the rear side member to improve the rigidity of the rear of the vehicle body.

For example, Patent Document 1 shows a rear bumper support structure for an automobile that can prevent the bumper stay from collapsing and also increase the strength of the area near the back door opening.

Specifically, as shown in the abstract of Patent Document 1, a strength reinforcement member (reference number 8 in Patent Document 1) with a fixed point on the bumper stay is provided at the approximately vertical joint between the rear side member and the rear end panel, and this strength reinforcement member is further extended to the vicinity of the back door opening to provide a fixed point on the rear end panel. Also, in order to increase the rigidity of the strength reinforcement member 8, a reinforcing plate (reference number 9 in Patent Document 1) is attached to this strength reinforcement member 8 so as to form a closed cross section.

JP 2009-208610 A

As described above, the strength reinforcing member 8 shown in Patent Document 1 is fixed to the bumper stay and has an upper end fixed to the rear end panel. However, the rear end panel has a panel structure that is low in rigidity and strength, and therefore has a problem in that the load is not transferred well between the upper end of the strength reinforcing member and the rear end panel.

For example, a load acting on the rear side member from the road surface or a towing load acting on the towing hook attached to the bumper stay can cause deformation in the rear end panel at the fixing point of the strength reinforcement member to the rear end panel, which can result in insufficient load transmission from the rear side member to the rear end panel.

Conversely, the load acting on the rear end panel during a minor rear collision could cause deformation of the rear end panel at the points where the strength reinforcement members are attached to the rear end panel, which could result in insufficient load transmission from the rear end panel to the rear side member.

In view of the above problems, at least one embodiment of the present invention aims to provide a rear body structure for a vehicle having a rear gate opening, which is capable of efficiently transmitting loads input from the road surface or towing hooks, or collision loads input from the rear of the vehicle, between the underbody and the upper body.

(1) The present invention has been invented to achieve the above-mentioned object, and at least one embodiment of the present invention is a rear body structure for a vehicle having a rear gate opening at a rear end of the vehicle body, the rear body structure including a pair of left and right rear side members provided extending in the fore-and-aft direction of the vehicle, a rear floor panel provided on the rear side members and constituting a vehicle rear luggage compartment floor, a rear end panel provided below the rear gate opening and extending in the vehicle width direction and connected to the rear end of the rear side member, a rear end inner panel that constitutes the rear end panel and is provided inside the vehicle body, and a rear end outer panel that is provided on the outside of the vehicle body, and The rear end brace comprises a closed cross-sectional portion formed by an inner panel and the rear end outer panel, a partition wall provided inside the closed cross-sectional portion and dividing the closed cross-sectional portion in the vehicle width direction, and a rear end brace provided at an angle in the front-to-rear direction of the vehicle, having a lower end connected to the rear side member via the rear floor panel and an upper end connected to the closed cross-sectional portion at a location above the rear floor panel where the partition wall is provided , the rear end brace being connected to the rear end inner panel on the inside of the vehicle body in the vehicle width direction and connected to a pair of left and right rear pillars provided on both the left and right sides of the rear gate opening on the outside of the vehicle width direction .

According to this configuration (1), the rigidity of the rear end panel is improved by providing a closed cross-sectional portion in the rear end panel and setting a bulkhead, which is a partition wall, within the closed cross-sectional portion. Furthermore, by connecting the rear end brace, which is connected to the rear side member, to the closed cross-sectional portion where the partition wall is provided, load is reliably transferred from the rear side member to the rear end panel, and conversely, load is transferred from the rear end panel to the rear side member.

The area above the rear floor panel is called the upper body, and the area below is called the underbody. With the above configuration (1), load is efficiently transferred between the underbody and the upper body.

(2) In some embodiments, the partition walls are provided at both left and right ends of the rear end panel in correspondence with the positions of the pair of left and right rear side members.

With this configuration (2), the partition walls are provided at both left and right ends of the rear end panel in correspondence with the positions of the pair of left and right rear side members, so that the rigidity of the rear end panel can be improved across the entire width of the vehicle with a simple structure, and further, load can be efficiently transferred between the rear side members and the rear end panel.

(3) In some embodiments, a pair of rear pillars are provided on both the left and right sides of the rear gate opening, and the lower ends of the rear pillars are respectively connected to the left and right ends of the rear end panel on which the partition wall is provided.

This configuration (3) allows efficient load transmission between the rear pillar and the rear end panel. Therefore, for example, a load acting on the rear side member from the road surface or a towing load acting on a towing hook attached to the bumper stay is efficiently transmitted from the rear side member to the rear end panel and further to the rear pillar. Furthermore, loads acting on the rear end panel or rear pillar during a minor collision from the rear are efficiently transmitted to the rear side member.

(4) In some embodiments, the partition wall extends in the fore-and-aft direction of the vehicle and has a front flange at its front end that connects to the rear end inner panel and a rear flange at its rear end that connects to the rear end outer panel, and the upper end of the rear end brace is fastened to the rear end inner panel together with the front flange by bolts.

This configuration (4) ensures a secure connection between the rear end brace, the partition wall, and the rear end panel. This ensures that loads are transferred between the rear side member and the rear end panel.

(5) In some embodiments, the lower end of the rear pillar is fastened to the rear end outer panel together with the rear flange by bolts.

This configuration (5) ensures a secure connection between the rear pillar, the partition wall, and the rear end panel. This ensures a secure load transfer between the rear side member, the rear end panel, and the rear pillar.

According to at least one embodiment of the present invention, a rear body structure of a vehicle having a rear gate opening can efficiently transmit loads input from the road surface or towing hooks, or collision loads input from the rear of the vehicle, between the underbody and the upper body.

1 is a perspective view seen from inside the vehicle compartment, showing an outline of the overall configuration of a rear vehicle body structure of a vehicle according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view of line AA in FIG. 1. 2 is a perspective view showing an outline of the overall configuration of the rear vehicle body structure of the vehicle according to the embodiment shown in FIG. 1, as viewed from the rear of the vehicle. FIG. 2 is a plan view seen from above, illustrating a state in which a rear end brace and a rear end panel are joined together in the rear vehicle-body structure for the vehicle according to the embodiment shown in FIG. 1 . FIG. 5 is a conceptual diagram of a cross section taken along line BB in FIG. 4. FIG. 5 is a schematic cross-sectional view of line BB in FIG. 4, showing another embodiment. FIG. 5 is a schematic cross-sectional view of line BB in FIG. 4, showing another embodiment.

Below, an embodiment of the present invention will be described in detail with reference to the drawings. However, the relative arrangement of components described as an embodiment or shown in the drawings is not intended to limit the scope of the present invention, but is merely an explanatory example. Note that the directions of up, down, front, back, left and right in the description are defined as the direction in which a passenger looks forward from the driver's seat. In each figure, "FR" indicates the front, "RHD" indicates the right, and "UPR" indicates the top.

One embodiment of the present invention will be described with reference to Figures 1 to 5. Figure 1 shows a rear body structure 3 of a vehicle 1. Figure 1 is a perspective view of the rear of the vehicle 1 seen from inside the passenger compartment. The vehicle 1 is provided with a rear gate opening 5 at the rear of the vehicle body that is opened and closed by a back door (not shown).

As shown in FIG. 1, a pair of left and right rear pillars 7 are provided to form the rear gate opening 5, and a rear end panel 9 is provided at the lower end of the rear pillars 7, which forms the lower side of the rear gate opening 5 and extends in the vehicle width direction.

A rear floor panel 11 that forms the floor is disposed at the bottom of the rear passenger compartment, which is used as the luggage space or passenger compartment of the vehicle 1. Both sides of the rear floor panel 11 are connected to the rear wheel house 13, and the rear end of the rear floor panel 11 is connected to the rear end inner panel 9a that is disposed substantially perpendicular to the rear end panel 9 (see FIG. 5).

A spare tire recess 15 for storing a spare tire is formed in the rear of the rear floor panel 11. A pair of rear side members 17 with an inverted hat-shaped cross section (a concave shape that opens upward) extend in the front-rear direction of the vehicle along the sides of the rear wheel house 13 on the underside of the rear floor panel 11 on both sides of the vehicle.

As shown in FIG. 1, the rear side member 17 has a rear side member flange 17a formed at the upper opening, and the rear floor panel 11 is disposed on the upper surface of the rear side member flange 17a. Note that FIG. 1 only shows the rear side member 17 on the left side of the vehicle, and the right side of the vehicle has a similar structure.

The rear floor panel 11 and the rear side members 17 form a closed cross-sectional portion (not shown) in the vehicle width direction. The rear end of the rear side member 17 is connected to the rear end inner panel 9a of the rear end panel 9 (see Figure 5).

A reinforcing member 19 is provided, one end of which is connected to the rear side member 17 and the other end of which is connected to the rear end panel 9 to reinforce the area around the rear gate opening 5.

As shown in Figures 1 and 2, the reinforcing member 19 is a plate-shaped sheet metal member that is inclined in the fore-and-aft direction of the vehicle, with its lower end 21 located on the lower side of the incline being connected by bolts 23 to the rear side member 17 via the rear floor panel 11, and its upper end 25 located on the upper side of the incline being connected by bolts 27 to the rear end inner panel 9a above the rear floor panel 11, forming a so-called brace structure in which the roughly horizontal rear side member 17 and the roughly vertical rear end panel 9 are reinforced by an oblique member. In this way, the reinforcing member 19 is composed of a rear end brace 29.

As shown in FIG. 2, the rear end panel 9 is formed of a rear end inner panel 9a provided inside the vehicle body and a rear end outer panel 9b provided outside the vehicle body, with a closed cross-sectional portion 31 formed between them, and the upper end portion 25 of the rear end brace 29 is connected to the rear end panel 9 by a bolt 27 to the rear end inner panel 9a.

The closed cross-section portion 31 is provided with a bulkhead 33, which is a partition wall that divides the closed cross-section portion 31 in the vehicle width direction, thereby increasing the rigidity of the rear end panel 9.

As shown in Figures 1 and 4, the rear end brace 29 is provided with multiple beads 35 that are formed in an uneven shape along the vehicle width direction and extend along the vehicle front-rear direction for reinforcement.

As shown in Figures 2 to 4, rear bumper stays 39 are provided on the extension of the rear side member 17 toward the rear of the vehicle to support the left and right sides of the rear bumper beam 37 that extends in the vehicle width direction, and the front end of the rear bumper stays 39 are connected to the rear end of the rear side member 17 via the rear end inner panel 9a.

A towing eyebolt 41 is attached to the rear end of the rear bumper stay 39 on the left side of the vehicle, and the towing load is directly input to the rear side member 17 via this towing eyebolt 41.

Next, the bulkhead (partition wall) 33 will be described. The bulkhead 33 is provided at both left and right ends of the rear end panel 9, which extends in the vehicle width direction in correspondence with the positions of the pair of left and right rear side members 17. In other words, it is provided only at both left and right ends. The lower ends of the pair of left and right rear pillars 7 are joined to both left and right ends of the rear end panel 9 where the bulkhead 33 is provided.

As shown in FIG. 4, the bulkhead 33 is made of a plate-shaped member made of sheet metal, extends in the fore-and-aft direction of the vehicle, and has a front flange 33a at its front end that connects to the rear end inner panel 9a, and a rear flange 33b at its rear end that connects to the rear end outer panel 9b.

As shown in FIG. 4, the upper end 25 of the rear end brace 29 has fastening portions at the inner and outer portions in the vehicle width direction. The inner portion in the vehicle width direction is fastened to the rear end inner panel 9a together with the front flange 33a of the bulkhead 33 by bolts 27a. The outer portion in the vehicle width direction is fastened to the lower end of the rear pillar 7 by bolts 27b.

On the other hand, the rear flange 33b of the bulkhead 33 is fastened to the rear end outer panel 9b by bolts 43.

As shown in FIG. 4, the shape of the bulkhead 33 in a plan view is such that the front flange 33a and the rear flange 33b are bent in opposite directions, but this is not limited thereto, and the front flange 33a and the rear flange 33b may be bent in the same direction to form an approximately U-shape.

The transmission of loads in the rear structure of the vehicle body configured as described above will be explained with reference to Figure 5. Figure 5 is a conceptual diagram of the cross-sectional shape taken along line B-B in Figure 4, and shows the directions of the input load and the transmitted load.

(Input from the road surface)
When the vehicle is traveling, an input load (arrow F1) is input from the road surface to the rear side member 17, which is a frame member of the vehicle, and is transmitted to the rear end panel 9 in the following order: input F1 from the road surface → rear side member 17 → rear end brace 29 → bulkhead 33, and further to the rear pillar 7.

Therefore, load is transferred more efficiently from the underbody to the upper body than if the rear end brace 29 were not present. Furthermore, because the rear end brace 29 is attached to a portion of the rear end panel 9 where the bulkhead 33 is installed, which has high rigidity, the input load (arrow F1a) transmitted from the rear end brace 29 is received by the bulkhead 33, and the load is transferred to the entire rear end panel 9. If the bulkhead 33 were not present, the input load transmitted from the rear end brace 29 would not be able to be received, and there is a risk that the surface deformation of the rear end panel 9 would be significant.

In this way, the load is efficiently transferred from the underbody to the upper body. As already explained, the area above the rear floor panel is called the upper body, and the area below is called the underbody.

(Input when towing)
When towing another vehicle, the towing load (arrow F2) input to the rear side member 17, which is a frame member of the vehicle, through the towing eye bolt 41 can be distributed not only to the rear side member 17 but also to the rear end panel 9 side through the rear end brace 29 because the rear end brace 29 is provided and is connected to a portion having high rigidity by the bulkhead 33. That is, the load can be distributed to the load borne by the rear side member 17 side (arrow F2a) and the load borne by the rear end brace 29 side (arrow F2b). Therefore, the load can be efficiently transmitted from the underbody to the upper body.

(Input during a minor collision)
Regarding a light collision load (arrow F3) input during a light collision with the rear of the vehicle, because the rear end brace 29 is connected to a portion whose rigidity is increased by the bulkhead 33, the light collision load (arrow F3) is transmitted from the rear end panel 9, which receives the collision load, to the rear end brace 29, and a shear input (arrow F3a) is applied to the upper surface of the rear side member 17, thereby suppressing deformation of the rear end of the rear floor panel 11. In other words, if the rear end brace 29 were not installed, there is a risk of deformation such that the rear end panel 9 is bent at the rear end of the rear floor panel 11 at part C in Figure 5.

According to the embodiment described above, the rigidity of the rear end panel 9 is improved by providing a closed cross-sectional portion 31 in the rear end panel 9 and providing a bulkhead 33 as a partition wall within the closed cross-sectional portion 31. Furthermore, the rear end brace 29 connected to the rear side member 17 is joined to a portion of the rear end panel 9 whose rigidity is increased by the installation of the bulkhead 33, so that load transfer from the rear side member 17 to the rear end panel 9 and conversely, load transfer from the rear end panel 9 to the rear side member 17 is ensured. Therefore, load transfer is efficient between the underbody and the upper body.

In addition, the bulkheads 33 are provided only at the left and right ends of the rear end panel 9 in correspondence with the positions of the pair of left and right rear side members 17, so the rigidity of the rear end panel 9 can be improved across the entire width of the vehicle with a simple structure.

Furthermore, because the lower end of the rear pillar 7 is connected to both the left and right ends of the rear end panel 9 on which the bulkhead 33 is provided, the load is efficiently transferred between the rear pillar 7 and the rear end panel 9. Therefore, the load is more effectively transferred between the underbody, including the rear side members, and the upper body, including the rear end panel and the rear pillar.

The bulkhead 33 has a front flange 33a that connects to the rear end inner panel 9a and a rear flange 33b that connects to the rear end outer panel 9b, and the upper end 25 of the rear end brace 29 is fastened to the rear end inner panel 9a together with the front flange 33a by bolts 27a (see FIG. 4), ensuring a secure connection between the rear end brace 29, bulkhead 33, and rear end panel 9. This ensures that load is transmitted between the rear side member 17 and the rear end panel 9.

Next, another embodiment will be described. In another embodiment, as shown in Figures 6A and 6B, the rear pillar reinforcement 45 provided at the lower end of the rear pillar 7 to reinforce the rear pillar 7 extends to the position of the bulkhead 33 and is fastened to the rear end outer panel 9b together with the rear flange 33b of the bulkhead 33 by bolts 43.

Figure 6A shows the rear pillar reinforcement 45 being fastened to the outside of the rear end outer panel 9b. Figure 6B shows the rear pillar reinforcement 45 being fastened to the inside of the rear end outer panel 9b.

In either the configuration of FIG. 6A or FIG. 6B, the rear pillar reinforcement 45 at the lower end of the rear pillar 7 is fastened to the rear end outer panel 9b together with the rear flange 33b of the bulkhead 33 by the bolt 43, so that the connection between the rear pillar 7, the bulkhead 33, and the rear end panel 9 is secure. This ensures that the load is transmitted between the rear side member 17, the rear end panel 9, and the rear pillar 7.

According to at least one embodiment of the present invention, the rear body structure of a vehicle having a rear gate opening can efficiently transmit loads input from the road surface or towing hooks, or collision loads input from the rear of the vehicle, between the underbody and the upper body, making it suitable for use in the rear body structure of a vehicle.

Reference Signs List 1 vehicle 3 rear body structure 5 rear gate opening 7 rear pillar 9 rear end panel 9a rear end inner panel 9b rear end outer panel 11 rear floor panel 13 rear wheel house 15 spare tire recess 17 rear side member 19 reinforcing member 23, 27, 43 bolts 27a, 27b bolt 29 rear end brace 31 closed cross section portion 33 bulkhead (partition wall)
33a Front flange 33b Rear flange 37 Rear bumper beam 39 Rear bumper stay 41 Towing eye bolt

Claims (5)

A rear body structure of a vehicle having a rear gate opening at a rear end of the vehicle body,
A pair of left and right rear side members extending in a front-rear direction of the vehicle;
a rear floor panel that is provided on the rear side member and that constitutes a rear luggage compartment floor of the vehicle;
a rear end panel that is provided below the rear gate opening and extends in a vehicle width direction and is connected to a rear end of the rear side member;
a rear end inner panel that configures the rear end panel and is provided inside the vehicle body, and a rear end outer panel that is provided outside the vehicle body;
a closed cross-sectional portion formed by the rear end inner panel and the rear end outer panel;
a partition wall provided inside the closed cross-sectional portion and partitioning the closed cross-sectional portion in a vehicle width direction;
a rear end brace that is provided at an angle in the vehicle longitudinal direction, a lower end of which is connected to the rear side member via the rear floor panel, and an upper end of which is connected to the closed cross-sectional portion above the rear floor panel at a location where the partition wall is provided;
Equipped with
the rear end brace is connected to the rear end inner panel on an inner side of the vehicle body in the vehicle width direction, and is connected to a pair of left and right rear pillars provided on both the left and right sides of the rear gate opening on an outer side of the vehicle body in the vehicle width direction . The rear body structure of a vehicle according to claim 1, characterized in that the partition walls are provided at both left and right ends of the rear end panel in correspondence with the positions of the pair of left and right rear side members. The rear body structure of a vehicle according to claim 2, characterized in that a pair of rear pillars are provided on both the left and right sides of the rear gate opening, and the lower ends of the rear pillars are respectively connected to the left and right ends of the rear end panel on which the partition wall is provided. The rear body structure of a vehicle according to any one of claims 1 to 3, characterized in that the partition wall extends in the vehicle longitudinal direction, has a front flange at its front end that is joined to the rear end inner panel, and a rear flange at its rear end that is joined to the rear end outer panel, and the upper end of the rear end brace is fastened to the rear end inner panel together with the front flange by bolts. The rear body structure of a vehicle according to claim 4, characterized in that the lower end of the rear pillar is fastened together with the rear flange to the rear end outer panel by bolts.

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