Vehicle body rear structure

Abstract

A vehicle body rear structure includes a rear wheel, a rear side frame, and a crush member. The rear wheel is disposed on a vehicle side. The rear side frame is disposed substantially along a vehicle front-rear direction and extends toward a vehicle rear side more than the rear wheel. The crush member is disposed on a vehicle rear side of the rear wheel in such a manner that at least a portion of the crush member overlaps the rear wheel in the vehicle front-rear direction. The crush member is fixed to the rear side frame.

Description

[0001] This application claims priority based on Japanese Patent Application No. 2022-113254, filed on July 14, 2022, the contents of which are incorporated herein by reference. Technical Field

[0002] This invention relates to the rear structure of a vehicle body. Background Technology

[0003] At the rear of the vehicle, a pair of rear side frames extending along the vehicle's longitudinal direction are positioned on the left and right, with bumper beams connected to the rear of the left and right rear side frames. When an impact load is input from the rear of the vehicle, the left and right rear side frames are crushed axially (in the vehicle's longitudinal direction), thereby absorbing the energy of the input impact load.

[0004] In recent years, rear body structures that can absorb more energy of impact loads when they are input from the rear of the vehicle have been proposed (for example, see Japanese Patent Application Publication No. 2004-1634 and Japanese Patent Application Publication No. Hei 6-16154).

[0005] In the rear structure of the vehicle body described in Japanese Patent Application Publication No. 2004-1634, there are downwardly recessed, generally U-shaped side recesses formed at the left and right ends of the rear floor plate. These side recesses are arranged behind the left and right rear wheels in a manner that overlaps with the rear wheels in the longitudinal direction. The concave portion of the side recess, which is in a generally U-shaped shape, extends along the longitudinal direction of the vehicle.

[0006] In this rear structure of the vehicle body, when an impact load is applied from the rear side, the applied load is distributed to the side recesses of the rear frame and rear floor. The applied impact load absorbs energy by crushing the rear frame and side recesses.

[0007] In addition, the rear structure of the vehicle body described in Japanese Patent Application Publication No. 6-16154 has tire abutment members and impact beams arranged in series on the rear side of the left and right rear wheels, opposite to the rear of the rear wheels.

[0008] In this rear structure of the vehicle body, when an impact load is applied from the rear, the load is distributed to the rear side frame and the crash beam. When an impact load is applied to the crash beam from the rear, the crash beam abuts against the rear wheel via the tire contact patch, causing the crash beam to break axially (in the longitudinal direction of the vehicle). As a result, the impact load applied from the rear absorbs energy by breaking the rear side frame and the crash beam. Summary of the Invention

[0009] The rear frame, which is located at the rear of the vehicle, is a long strip extending along the front-rear direction of the vehicle. Therefore, it is believed that the rear frame may bend and deform in the middle of its extension direction due to the input position and direction of the impact load input from the rear of the vehicle.

[0010] Therefore, in the case of the rear structure of the vehicle body described in Japanese Patent Application Publication No. 2004-1634 and Japanese Patent Application Publication No. Hei 6-16154, if the rear frame bends and deforms when an impact load is input, there is a concern that the energy absorption effect of the crushing of the rear frame will not be sufficient.

[0011] The present invention provides a rear vehicle body structure capable of stably crushing the rear frame when subjected to an impact load from behind the vehicle. This improves vehicle collision safety and contributes to the development of sustainable transportation systems.

[0012] The rear vehicle structure of one embodiment of the present invention is characterized by comprising: a rear wheel (e.g., rear wheel Wr in the embodiment) disposed on the side of the vehicle; a rear side frame (e.g., rear side frame 10 in the embodiment) disposed generally along the longitudinal direction of the vehicle and extending rearward beyond the rear wheel; and a crushing member (e.g., muffler 14 in the embodiment) disposed on the rear side of the rear wheel in a manner that at least a portion overlaps with the rear wheel in the longitudinal direction, wherein the crushing member is fixed to the rear side frame.

[0013] In the above structure, when an impact load is input from an object at the rear of the vehicle, the impact load is transmitted to the rear side frame. The rear side frame receives the impact load and gradually crushes, and as the crushing of the rear side frame progresses, a crushing member is trapped between the object at the rear of the vehicle and the rear wheel. During this period, the crushing member crushes together with the rear side frame, absorbing the energy of the impact load from the rear of the vehicle. From this state onwards, as the input of the impact load progresses further, the middle portion of the rear side frame in its extension direction will bend and deform, but because the rear side frame is fixed to the crushing member sandwiched between the object at the rear and the rear wheel, the bending deformation at the middle portion of the rear side frame is limited by the crushing member. As a result, with the bending deformation of the rear side frame limited, the energy of the impact load is sufficiently absorbed through the crushing of the rear side frame and the crushing member.

[0014] Alternatively, the crushing member may be a muffler for exhaust noise reduction (e.g., muffler 14 in the embodiment).

[0015] In this situation, there is no need to specially design impact-absorbing crushing components; the exhaust muffler can efficiently absorb impact loads. Therefore, by adopting this structure, it is possible to curb the increase in vehicle production costs while simultaneously further improving vehicle safety.

[0016] Alternatively, the crushing member can be fixed in the rear frame at a position slightly forward of the midpoint (midpoint cp) between the rear wheel and the rear end of the rear frame.

[0017] In this configuration, the crushing member is fixed at a position slightly forward of the aforementioned midpoint of the rear frame. Therefore, when an impact load is applied from the rear of the vehicle, and the rear frame begins to crush from the rear, the position of the crushing member is less likely to change significantly. Consequently, when an impact load is applied from the rear of the vehicle, the crushing member is stably clamped between the object behind the vehicle and the rear wheel. Thus, with this structure, bending deformation of the rear frame at the midpoint can be more reliably limited when an impact load is applied from the rear of the vehicle.

[0018] Preferably, the crushing member is located below the rear frame and fixed to the lower surface of the rear frame (e.g., the lower surface 14u in the embodiment).

[0019] In this scenario, when an impact load is input from the rear of the vehicle, if a crushing member is inserted between the object at the rear of the vehicle and the rear wheel, the crushing member effectively suppresses the vertical bending deformation of the rear frame from below. Therefore, compared to fixing the crushing member to the side of the rear frame, the rear frame is less prone to torsional deformation. Thus, with this structure, the rear frame can be crushed more stably when an impact load is input from the rear of the vehicle.

[0020] The rear vehicle body structure of the present invention, when subjected to an impact load from the rear of the vehicle, can limit the bending deformation of the rear side frame by means of a crushing member sandwiched between the rear object and the rear wheel. Therefore, when the rear vehicle body structure of the present invention is adopted, the rear side frame can be stably crushed when subjected to an impact load from the rear of the vehicle. Attached Figure Description

[0021] Figure 1 This is a bottom view of the rear of the vehicle in the embodiment.

[0022] Figure 2 The vehicle along the implementation method Figure 1 A sectional view along line II-II.

[0023] Figure 3 This is a perspective view of the part of the vehicle equipped with a muffler, viewed from below.

[0024] Figure 4 This is a perspective view of a vehicle in an embodiment where a muffler is installed.

[0025] Figure 5 This is a schematic side view of a vehicle in which the vehicle's deformation behavior is represented sequentially by (A), (B), and (C). Detailed Implementation

[0026] The embodiments of the present invention will now be described based on the accompanying drawings. It should be noted that, in the following description, "front and back," "up and down," and "left and right" refer to directions relative to the vehicle's direction of travel unless otherwise specified. Furthermore, arrows indicating the front of the vehicle (FR), the top of the vehicle (UP), and the left side of the vehicle (LH) are shown in appropriate locations in the drawings.

[0027] Figure 1 This is a view of the rear of vehicle 1 according to this embodiment from below. Figure 2 It is along Figure 1 A sectional view along line II-II.

[0028] exist Figure 1 , Figure 2 In the diagram, the symbol Wr represents the rear wheels positioned on the left and right sides of vehicle 1. The rear wheels Wr are symmetrically positioned on the left and right sides of vehicle 1. Additionally, a pair of rear side frames 10 are separately positioned on the lower rear of the vehicle body. Figure 1 Although only the left half of the rear of vehicle 1 is shown, the rear side frame 10 is also configured on the right side of the rear of the vehicle.

[0029] The left and right rear side frames 10 extend generally along the longitudinal direction of the vehicle. The front end of each rear side frame 10 is connected to a lower side beam (not shown) below the side of the passenger compartment, located closer to the front of the vehicle than the rear wheel Wr. A rear floor plate (not shown) is mounted on the upper surface of the left and right rear side frames 10. Each left and right rear side frame 10 extends rearward beyond the rear wheel Wr. Furthermore, a bumper beam 11 for the rear bumper is connected to the rear end of each left and right rear side frame 10.

[0030] The left and right rear side frames 10 are connected to each other in the middle of their length direction by a crossbeam 12. The left and right rear wheels Wr are positioned on the outer side of the connection position between the rear side frames 10 and the crossbeam 12 in the vehicle width direction.

[0031] Additionally, an exhaust pipe 13 connected to an engine (not shown) is located on the lower rear side of vehicle 1. A muffler 14 for exhaust noise reduction is connected to the exhaust pipe 13. The muffler 14 has a housing 15 of a predetermined shape that houses a muffler mechanism, and a tailpipe 16 extending from the rear of the housing 15 toward the rear of the vehicle. The housing 15 and the muffler mechanism inside are primarily made of metal. The muffler mechanism consists of, for example, multiple muffler chambers divided into several layers, and connecting pipes that communicate with each other.

[0032] In this embodiment, the muffler 14 is used as a crushing member, as described later. That is, when the muffler 14 receives an impact load from the rear of the vehicle, it absorbs the energy of the impact load by crushing the housing 15 and the internal silencing mechanism.

[0033] Figure 3 This is a perspective view showing the mounting position of the muffler 14 on the lower surface of the rear side of vehicle 1. Figure 4 This is a perspective view of vehicle 1 with the muffler 14 installed. It should be noted that... Figure 3 The image shows the state where the muffler 14 has been removed.

[0034] The muffler 14 is fixed to the lower surface 10u of the rear frame 10 via a metal bracket 20. The bracket 20 has an upper flange 20u fixed to the lower surface 10u of the rear frame 10, a lower flange 20l fixed to the upper surface of the housing 15 of the muffler 14, and a connecting wall 20c connecting the upper flange 20u and the lower flange 20l. A reinforcing rib 21 is formed in the connecting wall 20c extending along the direction connecting the upper flange 20u and the lower flange 20l.

[0035] like Figure 2 As shown, the muffler 14 is fixed in the rear frame 10 at a position slightly forward of the midpoint cp between the rear wheel wr and the rear end of the rear frame 10. That is, the upper flange 20u of the fixing bracket 20 is fixed at the aforementioned midpoint cp position slightly forward of the lower surface 10u of the rear frame 10.

[0036] Here, as Figure 1 As shown, the housing 15 of the muffler 14 is formed in a generally trapezoidal shape in a top (low) view. Specifically, the housing 15 of the muffler 14 is formed such that its front-to-back width gradually decreases from the inside to the outside in the vehicle width direction. The narrower portion of the outer side of the housing 15 in the vehicle width direction is located behind the rear wheel wr. Therefore, a portion of the muffler 14 is configured to overlap with the rear wheel wr in the front-to-back direction on the rear side of the rear wheel wr.

[0037] It should be noted that in this embodiment, the muffler 14 is disposed below each of the left and right rear frames 10, but the muffler 14 may also be disposed below only one side of the left and right rear frames 10.

[0038] Figure 5 This is a schematic side view showing the deformation behavior of vehicle 1 when an impact load is applied to vehicle 1 from the rear object 30, represented sequentially by (A), (B), and (C).

[0039] The following is for reference Figure 5This will illustrate the deformation behavior of vehicle 1 when an impact load is applied from the rear of the vehicle.

[0040] For example, when an impact load is applied from object 30 to the rear bumper at the rear of the vehicle, the impact load is transmitted as a load toward the front of the vehicle via the rear bumper to the rear of the rear frame 10 (see reference). Figure 5 (A)).

[0041] The rear frame 10 is subjected to impact loads and gradually crushes from the rear side toward the front side (see reference). Figure 5 (B)

[0042] Thus, when the rear frame 10 is crushed and deformed beyond a specified amount, the impact load is also transmitted to the rear of the muffler 14, which is then sandwiched between the vehicle object 30 and the rear wheel Wr. During this period, the muffler 14 and the rear frame 10 are crushed together in the longitudinal direction, absorbing energy from the rear of the vehicle.

[0043] As the impact load input progresses further from this state, the mid-section of the rear frame 10 in the extension direction sometimes bends upward. However, at this time, the lower surface 10u of the rear frame 10 is fixed to the muffler 14 sandwiched between the rear object 30 and the rear wheel wr. Therefore, the bending deformation at the mid-section of the rear frame 10 is limited by the muffler 14 (see reference). Figure 5 (C)).

[0044] As a result, the impact load input from the rear of the vehicle is fully absorbed by the crushing of the rear frame 10 and the muffler 14.

[0045] As described above, when an impact load is input from the rear of the vehicle, the rear vehicle body structure of this embodiment can limit the bending deformation of the rear side frame 10 by means of the muffler 14 (crushing member) sandwiched between the object 30 at the rear and the rear wheel Wr. Therefore, when the rear vehicle body structure of this embodiment is adopted, the rear side frame 10 can be crushed stably when an impact load is input from the rear of the vehicle.

[0046] Therefore, by adopting the rear structure of the vehicle body according to this embodiment, the collision safety of the vehicle can be improved, which contributes to the development of a sustainable transportation system.

[0047] Furthermore, in this embodiment, the rear structure of the vehicle body utilizes the exhaust muffler 14 as a crushing member located on the rear side of the vehicle behind the rear wheels. Therefore, there is no need to specially provide a crushing member for shock absorption; the existing muffler 14 can efficiently absorb impact loads. Thus, by adopting the structure of this embodiment, the increase in the product cost of the vehicle 1 can be suppressed, while simultaneously further improving the safety of the vehicle 1.

[0048] Furthermore, in the rear structure of this embodiment, the muffler 14, which serves as a crushing member, is fixed to a position slightly forward of the midpoint cp between the rear wheel wr and the rear end of the rear side frame 10 within the rear side frame 10. Therefore, by positioning the muffler 14 close to the base end side (lower side beam side) of the side frame 10, the position of the muffler 14 is less likely to change significantly when an impact load from the rear of the vehicle is applied and the rear side frame 10 begins to crush from the rear. Consequently, when an impact load from the rear of the vehicle is applied, the muffler 14 is stably clamped between the object 30 and the rear wheel wr at the rear of the vehicle. Therefore, with the structure of this embodiment, the bending deformation of the rear side frame 10 at the midpoint can be more reliably limited when an impact load from the rear of the vehicle is applied.

[0049] Furthermore, in the rear structure of this embodiment, the muffler 14, which serves as a crushing member, is fixed to the lower surface 14u of the rear side frame 10 below it. Therefore, when an impact load is input from the rear of the vehicle, and the muffler 14 is sandwiched between the object 30 and the rear wheel Wr on the rear side of the vehicle, the rear side frame 10 will not twist, and the bending deformation of the rear side frame in the vertical direction can be stably restricted. That is, in this structure, the bending deformation of the rear side frame in the vertical direction can be restricted from the position directly below the rear side frame 10, so the rear side frame 10 is less likely to twist compared to the case where the muffler is fixed to the side of the rear side frame 10.

[0050] Therefore, with the structure of this embodiment, the rear frame 10 can be crushed more stably when an impact load is input from the rear of the vehicle.

[0051] It should be noted that the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from its spirit.

[0052] For example, in the above embodiment, only a portion of the muffler 14, which is a crushing member, is arranged on the rear side of the rear wheel Wr in a manner that overlaps with the rear wheel Wr in the front-rear direction. However, the entire crushing member may also be arranged on the rear side of the rear wheel Wr in a manner that overlaps with the rear wheel Wr in the front-rear direction.

[0053] Furthermore, in the above embodiment, the muffler 14, as a crushing member, is arranged on the rear side of the rear wheel Wr in a manner that overlaps with the rear wheel Wr in the longitudinal direction. However, the crushing member is not limited to the muffler 14. The crushing member can also be a functional component other than the muffler 14. Moreover, the crushing member can also be a component specifically designed for shock absorption.

Claims

1. A rear structure of a vehicle body, characterized in that, The rear structure of the vehicle body includes: The rear wheels are located on the side of the vehicle; The rear frame is configured along the longitudinal direction of the vehicle and extends rearward beyond the rear wheels. as well as A crushing member is configured on the rear side of the rear wheel in a manner that at least a portion overlaps with the rear wheel in the longitudinal direction. The crushing component is fixed to the rear frame. The crushing member is fixed in the rear frame at a position slightly forward of the midpoint between the rear wheel and the rear end of the rear frame, thereby limiting the bending deformation of the rear frame at the midpoint when an impact load is input from the rear of the vehicle.

2. The rear structure of the vehicle body according to claim 1, characterized in that, The crushing component is a muffler used for exhaust noise reduction.

3. The rear structure of the vehicle body according to claim 1 or 2, characterized in that, The crushing member is located below the rear frame and is fixed to the lower surface of the rear frame.

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