JP6187427B2 - Rear body structure of the vehicle - Google Patents

Description

  The present invention relates to a side body structure of a vehicle, and more particularly, to a vehicle equipped with a bumper rain extending in a vehicle width direction attached to a pair of left and right connecting members connected to a pair of left and right rear side frames via a rear end panel. It relates to the rear body structure.

Conventionally, a pair of left and right rear side frames are provided, and bumper reinforcements (hereinafter referred to as the bumper reinforcement) extending in the vehicle width direction through a pair of left and right crash cans capable of absorbing collision energy at the rear ends of the pair of rear side frames. , Abbreviated as bumper rain) is known (for example, Patent Document 1).
Thereby, at the time of rear collision of the vehicle, the collision energy is absorbed by the crash can being crushed and deformed in the axial direction by the collision load transmitted from the bumper rain that reinforces the rear bumper. In addition to the crushing deformation of the crash can, the rear side frame is further subjected to compression deformation and bending deformation to further absorb the collision energy and reduce the impact acting on the passenger compartment.

JP 2009-227069 A

  Incidentally, there is a demand for further improving the collision energy absorption performance at the rear of the vehicle body at the time of a collision. This can be achieved by increasing the overall length of the crash can or increasing the plate thickness of the crash can. However, in this case, there is a possibility that a new problem of increasing the weight of the vehicle body may occur. It is also required to obtain a collision energy absorption performance more stably.

  An object of the present invention is to provide a rear body structure or the like of a vehicle that can improve the collision energy absorption performance of the rear part of the vehicle body at the time of a collision.

The rear body structure of the vehicle according to claim 1 includes a pair of left and right rear side frames extending in the front-rear direction, a rear end panel disposed at a rear end portion of the pair of rear side frames, and the pair of rear side frames. a connecting member a pair of left and right that are connected through a rear end panel, the rear vehicle body structure of a vehicle provided with a bumper reinforcement extending in the key has been the vehicle width direction to the connecting member of said pair, said pair A weakened portion is formed in the lower end side portion of the connecting member, and the rigidity of the lower end side portion of the pair of connecting members is formed lower than the rigidity of the upper end side portion, and the weakened portion is arranged before and after the pair of connecting members. Is formed on the rear side of the central portion in the direction, and when a collision load is applied to the bumper reinforcement from the rear of the vehicle body, the rotation extending in the vehicle width direction of the bumper reinforcement. About the axis to facilitate rotation toward the lower front side, it is characterized in that the rear end surface of the bumper reinforcement is configured to face contact with the rear end panel.

In the rear vehicle body structure of this vehicle, the rigidity of the lower end side portion of the pair of connecting members is formed lower than the rigidity of the upper end side portion. Therefore, when a collision load acts on the bumper reinforcement, the bumper reinforcement is Collision energy can be absorbed by being largely bent and deformed forward and downward about the rotation axis extending in the direction. In addition, the bumper reinforcement can be rotated 90 degrees or more around the rotation axis extending in the vehicle width direction, and the rear end surface of the bumper reinforcement can be brought into surface contact with the rear end panel. It can be dispersed over a wide range through the panel, and a stable collision energy absorption performance can be obtained.

According to a second aspect of the present invention, in the first aspect of the invention, the connecting member has a pair of left and right corners at the lower end, and the weakened portion has a pair of left and right corners at the lower end of the connecting member. It is characterized by a hole part that is cut out .
As a result, the connecting member can be rotationally deformed around the rotation axis extending in the vehicle width direction with a simple configuration.

The invention of claim 3 is characterized in that, in the invention of claim 1 or 2 , the connecting member is formed by a crush can having a substantially cross-shaped longitudinal section in the vehicle width direction .
Thereby, the collision energy absorption performance of the crash can having a substantially cross-shaped longitudinal section in the vehicle width direction can be further improved.

  According to the vehicle rear body structure of the present invention, it is possible to improve the collision energy absorption performance of the vehicle rear portion at the time of a collision.

1 is a perspective view of a rear part of a vehicle body viewed from the left side of a vehicle according to a first embodiment. It is a side view. It is the perspective view seen from the left lower side. It is a disassembled perspective view. It is a top view of a crash can. It is a side view. It is explanatory drawing of the deformation | transformation state of the crash can at the time of a rear collision, Comprising: (a) is a state before a collision, (b) is a middle state of a collision, (c) is a side view which shows a late state of a collision.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The following description exemplifies a case where the present invention is applied to a vehicle, and does not limit the present invention, its application, or its use. In the figure, the direction of arrow F is assumed to be the front, the direction of arrow L is assumed to be left, and the direction of arrow U is assumed to be upward.

Embodiment 1 of the present invention will be described below with reference to FIGS.
As shown in FIGS. 1 to 4, a vehicle V includes a pair of left and right rear side frames 1 extending in the front-rear direction, a rear end panel 2 disposed at a rear end portion of the pair of rear side frames 1, and a pair of vehicles. A pair of left and right crash cans 3 (connecting members) connected to the rear side frame 1 via a rear end panel 2, and a bumper reinforcement (hereinafter referred to as a bumper reinforcement) attached to the pair of crash cans 3 and extending in the vehicle width direction. 4) and the like.

First, the premise structure of the vehicle V is demonstrated.
An opening 5 that is opened and closed by a lift gate (not shown) is formed at the rear of the vehicle V. A cargo space at the rear of the vehicle body is formed in the opening 5 and is configured to be accessible from the outside by opening and closing the lift gate. The opening 5 is formed in a substantially rectangular shape by a roof panel 6, a pair of left and right rear pillars 7 supporting the roof panel 6, and a rear cross member 11. A side outer panel 8 is connected to the side of the rear pillar 7.

A rear floor panel 9 that forms the bottom of the cargo space is disposed in the cargo space.
A side portion of the rear floor panel 9 is cut out in conformity with the wheel house inner 10 and connected to a lower end portion of the wheel house inner 10. The rear floor panel 9 is formed with a recess 9a capable of storing a spare tire (not shown).

Next, the pair of left and right rear side frames 1 and the rear end panel 2 will be described.
As shown in FIGS. 2 to 4, a pair of left and right rear side frames 1 extending in the front-rear direction are arranged on the lower surface side of the rear floor panel 9 near the outer end in the vehicle width direction.
The pair of rear side frames 1 is formed of a high-tensile steel plate and forms a closed cross section extending in the front-rear direction in cooperation with the rear floor panel 9.

  A middle part of the pair of rear side frames 1 is provided with a collision energy absorbing mechanism (not shown) capable of absorbing the collision energy by actively bending and deforming the rear half part upward (bending deformation) at the time of rear collision. Yes. A rear end panel 2 is coupled to the rear end portions of the pair of rear side frames 1.

The upper half of the rear end panel 2 and the rear end member 12 cooperate to form a closed cross section extending in the vehicle width direction on the upper side of the rear side frame 1.
The upper end flange portion of the rear end member 12 is joined to the upper end flange portion of the rear end panel 2, and the lower end flange portion of the rear end member 12 is joined to the front surface of the middle stage portion of the rear end panel 2. Further, the front surface of the lower end portion of the rear end panel 2 is joined to the upper end of the rear end portion of the rear side frame 1.

Next, the left and right pair of crash cans 3 will be described.
As shown in FIGS. 2 to 4, the pair of left and right crash cans 3 are connected via the rear end panel 2 so as to be coaxially disposed at the rear ends of the pair of left and right rear side frames 1. . The pair of crash cans 3 absorbs collision energy by collapsing by axial compression deformation in the front-rear direction due to a collision load acting from the middle part in the vertical direction of the bumper rain 4 at the time of a rear collision, and achieves an intended energy absorption performance. Each size is made of steel.
Since the pair of crash cans 3 has a symmetrical structure, the left crash can 3 will be mainly described below.

The crash can 3 has a closed cross section that extends in the front-rear direction by joining the top wall portion and the bottom wall portion of the outer panel 3a to the top wall portion and the bottom wall portion of the inner panel 3b, respectively.
The front end portion of the crash can 3 is joined to a flat set plate 13 by welding, and the set plate 13 is fastened and fixed to a mounting portion provided on the rear end panel 2 by a plurality of bolts 14. An inner panel 4 a of the bumper line 4 is joined to the rear end portion of the crash can 3.

As shown in FIGS. 5 and 6, the crash can 3 has an axially orthogonal cross section formed in a substantially cross shape by four projecting portions 3 s to 3 v extending in the front-rear direction provided on the top, bottom, left, and right top surface portions. .
The upper end portion of the projecting portion 3s and the lower end portion of the projecting portion 3t protrude rearward as compared with the other portions to form the mounting portion of the inner panel 4a of the bumper line 4.
Grooves 3x extending in a concave shape in the vertical direction are formed in the vicinity of the rear ends of the protrusion 3u and the protrusion 3v, respectively. Thereby, at the time of a rear collision, the crush deformation (buckling deformation) of the crash can 3 in the axial direction can be promoted, and the collision energy absorption performance is enhanced.

As shown in FIGS. 2, 3, 5, and 6, the left and right corners of the lower end on the rear end side of the protruding portion 3 t have a pair of left and right first hole portions 3 y (fragile portions) and the first A pair of left and right second hole portions 3z (fragile portions) disposed in front of the hole portion 3y is formed. The pair of first hole portions 3y are respectively disposed so as to be located directly below the protruding portion 3u and the groove portion 3x of the protruding portion 3v in a side view.
Thereby, the rigidity of the protrusion 3t can be made weaker than the rigidity of the protrusion 3s, and the rear end of the crash can 3 extends in the vehicle width direction when a collision load acts on the bumper rain 4 at the time of a rear collision. It can be rotated and deformed by 90 degrees or more around the rotation axis toward the lower front side. Moreover, since the front-rear direction position of the first hole 3y and the front-rear direction position of the groove part 3x are aligned, the rotational deformation of the crash can 3 can be promoted.

  As shown in FIG. 2 to FIG. 4, the bumper line 4 forms a closed cross section that extends in the vehicle width direction in cooperation with an inner panel 4 a having a substantially hat-like longitudinal section and a flat outer panel 4 b. A bumper fascia 15 that covers the outer side of the outer panel 4b is attached to the bumper line 4.

Based on FIG. 7A to FIG. 7C, the deformation behavior of the crash can 3 at the time of a rear collision by the obstacle B will be described using an experimental model. For convenience of explanation, the bumper fascia of the vehicle V is omitted. Further, contact and surface contact with the set plate 13 interposed therebetween are simply expressed as contact and surface contact.
As shown in FIG. 7A, the obstacle B installed behind the bumper rain 4 moves forward at a predetermined speed and collides with the outer panel 4b. In the initial stage of the collision, the collision load acts on the lower half of the crash can 3 more than the upper half of the crash can 3 while the lower half of the crash can 3 is crushed and deformed in the front-rear direction including the groove 3x and the first hole 3y. Rotational deformation is started toward the front lower side around the rotation axis extending in the width direction.

  As shown in FIG. 7B, in the middle of the collision, the crash can 3 is rotated and deformed due to the crushing deformation of the lower half, so that the outer panel 4b changes to a substantially horizontal state rotated approximately 90 degrees with respect to the initial position. ing. At this time, the collision load that is not absorbed by the crash can 3 is transmitted to the rear side frame 1 from the path passing through the crash can 3 and the path from the edge portion of the outer panel 4b, and both the compression deformation and the bending deformation of the rear side frame 1 are started. Is done.

As shown in FIG. 7C, in the latter half of the collision, the crash can 3 is further rotated and deformed, so that the outer panel 4b is changed to a substantially vertical state rotated about 180 degrees with respect to the initial position.
Thereby, a large collision load can be absorbed using the rotational deformation of the crash can 3. Further, even if the outer panel 4b and the rear end panel 2 come into contact with each other, a surface contact state is established, so that the collision load can be dispersed over a wide range via the rear end panel 2.
Moreover, since the rear side frame 1 is bent and deformed upward from the middle part by the operation of the collision energy absorbing mechanism, the influence of the collision load on the passenger compartment can be minimized.

Next, operations and effects of the rear vehicle body structure of the vehicle V will be described.
According to the rear vehicle body structure of the vehicle V, since the rigidity of the lower end side portion of the pair of crash cans 3 is formed lower than the rigidity of the upper end side portion, when a collision load acts on the bumper rain 4, the bumper rain 4 The collision energy can be absorbed by being largely bent and deformed downward and forward about the rotation axis extending to the front. Further, since the bumper rain 4 can be rotated 90 degrees or more around the rotation axis extending in the vehicle width direction, and the outer panel 4b of the bumper rain 4 can be brought into surface contact with the rear end panel 2, the collision load is applied to the rear end panel 2. And a stable collision energy absorption performance can be obtained .

  Since the first and second holes 3y and 3z are formed in the lower end side portion of the pair of crash cans 3, the crash can 3 can be rotated and deformed around the rotation axis extending in the vehicle width direction with a simple configuration.

  The first and second holes 3y and 3z, when a collision load acts on the bumper rain 4 from the rear of the vehicle body, promotes rotation toward the front lower side around the rotation axis extending in the vehicle width direction of the bumper rain 4, Since the outer panel 4b of the bumper rain 4 is configured to come into surface contact with the rear end panel 2, the outer panel 4b of the bumper rain 4 can be brought into surface contact with the rear end panel 2 reliably, and the collision load is distributed over a wide range via the rear end panel 2. can do.

  Since the connecting member is formed by the crush can 3 having a substantially cross-shaped longitudinal cross section in the vehicle width direction, the first and second holes 3y and 3z are formed on the rear side of the center portion in the front-rear direction of the crush can 3. The crash energy absorption performance of the crash can 3 having a cross-shaped longitudinal section in the vehicle width direction can be further improved.

Next, a modified example in which the embodiment is partially changed will be described.
1) In the above-described embodiment, the example in which the fragile portion is configured by the four first and second hole portions provided at the corners of the projecting portion of the crash can has been described. The number of holes can be set arbitrarily according to the required specifications. Moreover, it may replace with a hole part and a notch part and a bead part may be sufficient.
Furthermore, the crush can is composed of upper and lower divided bodies, and the rigidity of the lower end portion can be made lower than the rigidity of the upper end portion by providing differences in the material and thickness of the upper and lower divided bodies. It is.

2] In the above-described embodiment, the example in which the connecting member is configured by a crush can having a substantially vertical cross-section is described, but the same effect can be obtained even if the connecting member is configured by a crush can having a rectangular vertical cross-section. . In addition, when the connecting member does not need an axial compression deformation function at the time of a light collision, a bumper stay can be used instead of the crash can.

3) In the above embodiment, an example has been described in which the outer panel rotates approximately 180 degrees relative to the initial position and comes into surface contact with the rear end panel. However, surface contact that can be expected to absorb impact energy by rotating at least 120 degrees or more. An area can be secured. Preferably, the rotational deformation is 160 degrees or more.

4) In addition, those skilled in the art can implement the present invention with various modifications added without departing from the spirit of the present invention, and the present invention includes such modifications. is there.

V Vehicle 1 Rear side frame 2 Rear end panel 3 Crash can 3y First hole 3z Second hole 4 Bumper rain 4b Outer panel

Claims (3)

A pair of left and right rear side frames extending in the front-rear direction, a rear end panel disposed at a rear end portion of the pair of rear side frames, and a pair of left and right connected to the pair of rear side frames via the rear end panel A vehicle rear body structure comprising: a connecting member; and a bumper reinforcement attached to the pair of connecting members and extending in a vehicle width direction.
Forming a fragile portion on the lower end side portion of the pair of connecting members, and forming a lower end portion rigidity of the pair of connecting members lower than that of the upper end portion ;
The fragile portion is formed on the rear side of the center portion in the front-rear direction of the pair of connecting members, and when a collision load acts on the bumper reinforcement from the rear of the vehicle body, the bumper reinforcement of the bumper reinforcement A rear body structure of a vehicle, wherein the rear end surface of the bumper reinforcement is brought into surface contact with the rear end panel by accelerating rotation toward a front lower side around a rotation axis extending in a vehicle width direction. . The connecting member has a pair of left and right corners at the lower end;
2. The rear body structure of the vehicle according to claim 1, wherein the fragile portion includes a hole portion in which a pair of left and right corner portions of a lower end portion of the connecting member is cut out . The rear body structure of the vehicle according to claim 1 or 2, wherein the connecting member is formed by a crush can having a substantially cross-shaped longitudinal section in the vehicle width direction .