JP6831812B2 - Vehicle rear structure - Google Patents

Description

The present invention relates to a vehicle rear structure capable of suitably protecting a power storage device mounted on the vehicle rear.

For example, in a hybrid vehicle, a battery (power storage device) may be mounted at the rear of the vehicle. As an example, there is one described in Patent Document 1.
In the structure described in the document, a downwardly recessed recess is provided in the floor portion of the vehicle interior at the rear of the vehicle, and a battery is disposed in the recess. In such a configuration, it is desirable to prevent the battery from being damaged when the vehicle collides backward.
Therefore, in the same document, a reinforcement (rear center member in the same document) is provided under the bottom wall portion of the floor portion. The rear portion of this reinforcement is joined to the rear end of the bottom wall portion and extends to the front side of the vehicle, and the front portion is joined to a floor cross member provided directly under the battery and extending in the vehicle width direction. Further, this reinforce has a plurality of bent portions bent up and down in the side view of the vehicle, and each bent portion is provided with a fragile portion.
According to such a configuration, when the vehicle causes a rear collision and a load input of a predetermined value or more is applied to the rear portion of the vehicle, the reinforcement bends up and down starting from a plurality of fragile portions. This makes it difficult for the rear end member of the vehicle to collide with the battery.

However, in the above-mentioned prior art, there is room for improvement as described below.

That is, in the above-mentioned prior art, when the vehicle has a rear collision, the collision energy is absorbed by bending a plurality of points of the reinforcement up and down, and the rear end member of the vehicle is prevented from approaching the battery. It just does. Therefore, when the rear collision load is considerably large, sufficient energy absorption cannot be achieved only by the bending action of the reinforce, and the rear end member of the vehicle may rush into the front side of the vehicle and collide strongly with the battery. is there. In order to suppress such a risk, it is desirable to arrange the battery considerably forward from the rear end member of the vehicle, but such arrangement may be difficult due to various circumstances. In particular, in the case of a compact car, such an arrangement is more difficult, and it is difficult to appropriately prevent the above-mentioned problems.
Further, in a hybrid vehicle, a fuel tank may be arranged at a position on the front side of the vehicle, but in such a case, the battery is pushed toward the front side of the vehicle and collides with the fuel tank. There is a possibility that this fuel tank will be damaged. Therefore, it is required to appropriately prevent or suppress such a situation.

Japanese Unexamined Patent Publication No. 2016-185739

The present invention has been conceived under the above-mentioned circumstances, and appropriately prevents or suppresses problems such as damage to a power storage device such as a battery mounted on the rear part of the vehicle at the time of a rear collision of the vehicle. Moreover, it is an object of the present invention to provide a vehicle rear structure that has a simple structure and can be manufactured at a low cost.

In order to solve the above problems, the following technical measures are taken in the present invention.

The vehicle rear structure provided by the present invention is provided on the floor portion of the vehicle interior at the rear of the vehicle, and is fixed to a recess that is recessed downward and on the bottom wall portion of the recess so as to be located in the recess. The power storage device, the reinforcement that is joined to the lower surface side of the bottom wall portion of the recess and extends from the rear portion of the bottom wall portion to the front side of the vehicle, and the rear portion of the vehicle in the vehicle front-rear direction at intervals in the vehicle width direction. A vehicle rear structure comprising a floor cross member that is fixed so as to be bridged between a pair of left and right rear side members extending and the front portion of the reinforce is joined, and is one of the reinforces. When the vehicle is provided in the front-rear direction of the vehicle at a portion corresponding to the rear end of the mounting area of the power storage device or a portion near the rear of the vehicle close to this portion, and a load input exceeding a predetermined value is received from the rear side of the vehicle. It is characterized in that it is further provided with a rigid breaking point that enables the power storage device to rotate in a downward-sloping manner by serving as a starting point of bending deformation.

According to such a configuration, in a normal state, in addition to being able to appropriately and efficiently reinforce the concave portion of the floor portion by using a floor cross member, reinforce, or the like, the following effects can be further obtained.
First, when a rear collision of the vehicle occurs and a load input of a predetermined value or more is applied to the rear part of the vehicle, the reinforcement is bent and deformed starting from the position of the rigidity breaking point, but in that case, the power storage device causes the rigidity breaking. It is displaced so as to rotate backward with respect to the point. Therefore, as compared with the conventional technology in which the power storage device collides with the rear end member of the vehicle that has entered the front side of the vehicle without performing such rotation, the damage to the power storage device is reduced, and the power storage device suffers less damage than the conventional technology. The protection performance can be improved. In addition, since it is eliminated that the power storage device is pressed to the front side of the vehicle as it is, when a fuel tank exists on the front side of the vehicle, the power storage device collides with the fuel tank. It is possible to appropriately eliminate the damage caused by these. Further, it is possible to prevent the power storage device from being blown upward.
Secondly, in the present invention, a rigid break point is provided at a predetermined portion of the reinforce, and the power storage device or the like is protected by rotating the power storage device in a downward-sloping manner at the time of a rear collision of the vehicle. It is simple and does not require the use of many large reinforcing members. Therefore, it is possible to appropriately improve the productivity, reduce the manufacturing cost, and reduce the weight of the vehicle.

In the present invention, preferably, a protective member is provided which is fixed on the bottom wall portion of the recess and surrounds at least the front and rear and the upper side of the power storage device to protect the power storage device, and is caused by the load input. When the lower back panel at the rear of the vehicle rushes into the front side of the vehicle, the lower back panel is configured to be able to come into contact with the protective member.

According to such a configuration, in addition to being able to more appropriately protect the power storage device due to the presence of the protective member, when the vehicle causes a rear collision and the lower back panel rushes to the front side of the vehicle, the lower back panel By the action of contacting the protective member and sandwiching the protective member, it is more ensured that the power storage device is not blown upward.

Other features and advantages of the present invention will become more apparent from the following description of embodiments of the invention with reference to the accompanying drawings.

It is a side sectional view of the main part which shows an example of the vehicle rear structure which concerns on this invention. FIG. 2 is a sectional view taken along line II-II of FIG. It is the schematic bottom view of the main part of FIG. It is a side sectional view of the main part which shows the operation example of the vehicle rear structure shown in FIG.

Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.

The vehicle rear structure A shown in FIG. 1 is applied to, for example, a hybrid vehicle, and is an example of a floor portion 2 (rear floor portion) in the passenger compartment 1 of the vehicle, a recess 20 provided in the floor portion 2, and a power storage device. The battery 3, the protective member 4 for the battery 3, the first and second reinforces 5A and 5B, and the rigid break point RP are provided.
The first and second reinforces 5A and 5B correspond to specific examples of reinforces in the present invention, and in the present embodiment, the second reinforce 5B is a tow hook. In the drawings, reference numeral 9 indicates a rear wheel.

The floor portion 2 is configured by using a floor panel made of a thin metal plate. The recess 20 is a downwardly recessed region provided in a portion of the vehicle interior 1 corresponding to the luggage compartment. The rear wall portion of the recess 20 is a lower back panel 6, and the upper portion thereof is a box cross-sectional portion 60 in which a lower back inner panel 6a and a lower back outer panel 6b are combined. Above the box cross section 60 is a rear opening 11 that can be opened and closed by the back door 10. The front wall portion 21 of the recess 20 is provided with a step portion 21a, and the step portion 21a is useful for smoothly bending and deforming the front wall portion 21 at the time of a rear collision of a vehicle described later. A fuel tank 18 is provided on the front side of the front wall portion 21 of the vehicle.

The battery 3 is, for example, a battery for auxiliary equipment such as a lead storage battery, but instead of this, a main battery for driving or the like can be used. The battery 3 is fixed on the bottom wall portion 22 of the recess 20. More specifically, the battery 3 is placed on the tray 7 for the battery, and its upper surface is pressed by the battery clamp 71 to which a downward pressing force is applied by using the J bolt 70, and the battery 3 is pressed on the tray 7. It is fixed to.
The protective member 4 has a portal shape having a plurality of guard plate portions 4a to 4c for surrounding and protecting the front and rear and the upper side of the battery 3. The protective member 4 is fixed on the bottom wall portion 22 by means such as co-fastening with the tray 7 using bolts.

The first and second reinforces 5A and 5B reinforce the floor portion 2 in order to protect the battery 3, and when a load is input from the rear side of the vehicle at the time of a rear collision of the vehicle, this load is directly applied to the battery 3. It is a member for preventing the action on the battery. The first reinforce 5A is, for example, a member having a cross-section hat shape, is joined to the lower surface of the bottom wall portion 22, extends from the lower portion of the lower back panel 6 or a portion in the vicinity thereof to the front of the vehicle, and is front to the floor cross member 8. Are joined. Similar to the first reinforce 5A, the floor cross member 8 is, for example, a member having a cross-section hat shape, and is located at the rear of the vehicle on both sides in the vehicle width direction and in the vehicle front-rear direction, as is often shown in FIG. Both ends are connected to a pair of left and right rear side members 81 that extend, and extend in the vehicle width direction. The floor cross member 8 is located below the mounting area S of the battery 3 or on the front side of the vehicle.

As described above, the second reinforce 5B is a tow hook, and is configured by using, for example, a bent round bar member. The rear portion of the second reinforce 5B is joined to the rear portion of the lower surface portion of the first reinforce 5A, and the front portion thereof is located directly below the rear end portion Sa of the mounting area S of the battery 3. It is joined to the lower surface of the first reinforce 5A. Preferably, as shown in FIG. 2, a concave portion 50 is formed on the lower surface side of the first reinforce 5A, and the concave portion 50 is formed as a means for strengthening the joint between the first and second reinforces 5A and 5B. A means for fitting a part of the second reinforce 5B into the portion 50 is adopted.

In the present embodiment, the rigidity break point RP is defined as a rear region in which the second reinforce 5B overlaps and a front region in which the second reinforce 5B does not overlap in the longitudinal direction of the first reinforce 5A. It is a boundary part. The total rigidity of the first and second reinforces 5A and 5B suddenly changes at the position of the above-mentioned rigidity break point RP, and in the region in front of the rigidity break point RP, the first reinforce 5A has a second Since the reinforce 5B is not joined, the rear region is a region having higher rigidity than the front region. The rigid break point RP is located below the rear end Sa of the mounting area S of the battery 3. In the present embodiment, the battery 3 is mounted on the tray 7, and the tray 7 and the protective member 4 are mounted on the bottom wall portion 22 by using common bolts or the like, and the battery 3 is mounted on the mounting area S. The concept also includes mounting areas for the tray 7 and the protective member 4.

Next, the operation of the vehicle rear structure A described above will be described.

First, in a normal state, the first and second reinforces 5A and 5B, the floor cross member 8 and the like efficiently reinforce the recess 20 of the floor portion 2 so as not to cause insufficient rigidity. it can.

On the other hand, when a rear collision occurs in the vehicle and a forward-looking load F of a predetermined value or more is input to the rear portion of the vehicle, a part of the load F is input to the first and second reinforces 5A and 5B. Here, since the rigid break point RP is provided in the combined structural portion of the first and second reinforces 5A and 5B, the first reinforce 5A is bent and deformed starting from the rigid break point RP. To do. Since the front portion of the first reinforce 5A is joined to the floor cross member 8, it exerts a certain amount of tension when it receives the above-mentioned load F. Therefore, it is ensured that the first reinforce 5A is bent and deformed starting from the rigidity breaking point RP. The bending deformation is performed so that the battery 3 and the protective member 4 rotate in the direction indicated by the arrow Na about the rigidity breaking point RP and form a rearward downward shape (see also FIG. 4). Since the total rigidity of the first and second reinforcements 5A and 5B is larger in the rear region than in the rigidity break point RP than in the front region, the first one can be obtained by inputting a load from the rear of the vehicle. It is further ensured that the Reinforce 5A is bent and deformed at the position of the rigid break point RP.

The rotation of the battery 3 and the protective member 4 is performed while the front wall portion 21 of the recess 20 is deformed, and the front wall portion 21 is provided with a step portion 21a in advance as described above. Therefore, it is possible to smoothly deform the front wall portion 21 starting from the step portion 21a so that the rotational operation of the battery 3 and the protective member 4 is not significantly hindered by the presence of the front wall portion 21.

In this way, if the first reinforcement 5A is bent and deformed at the position of the rigid break point RP to rotate the battery 3 and the protective member 4 in a downward-sloping manner, the battery 3 and the protective member 4 are on the front side of the vehicle. It is possible to reduce the amount of displacement to. As a result, the battery 3 and the protective member 4 are prevented from colliding strongly with the fuel tank 18 located on the front side of the vehicle, and both the fuel tank 18 and the battery 3 are appropriately protected. Of course, in this vehicle rear structure A, each member of the vehicle rear portion on the rear side of the vehicle with respect to the mounting area S of the battery 3 is deformed, and the front wall portion 21 of the recess 20 is deformed, resulting in a collision. Energy can be absorbed efficiently.

When the load F is large, the lower back panel 6 rushes into the front side of the vehicle considerably. In this case, as shown in FIG. 4, the lower back panel 6 lowers the guard plate portion 4b at the rear of the protective member 4. It is appropriately avoided that the back panel 6 comes into contact with the lower back panel 6 and collides with the battery 3 itself. In addition, when the lower back panel 6 comes into contact with the guard plate portion 4b, the protective member 4 is sandwiched between the lower back panel 6 and the deformed front wall portion 21, so that the battery The effect of appropriately preventing the fact that 3 is blown upward can be obtained.

The present invention is not limited to the contents of the above-described embodiments. The specific configuration of each part of the vehicle rear structure according to the present invention can be variously redesigned within the scope intended by the present invention.

In the above-described embodiment, the rigidity breaking point RP is provided at a portion (immediately below the rear end Sa) of the battery 3 in the front-rear direction of the battery 3 that coincides with the rear end Sa of the mounting region S. Is not limited to this. In the present invention, the position may be closer to the rear end Sa of the mounting area S of the battery 3 in the front-rear direction of the vehicle, and may be closer to the rear of the vehicle than the rear end Sa. Even in this case, when the first reinforce 5A is bent at the rigid break point RP, the battery 3 can be rotated in a downward-sloping manner to obtain the effect intended by the present invention.

In the above-described embodiment, the tow hook is used as the second reinforce 5B, which is rational, but the present invention is not limited to this, and a member other than the tow hook is used as the second reinforce 5B. You can also do it. Further, the reinforces referred to in the present invention do not necessarily have to be configured by combining a plurality of reinforces, and for example, the reinforce may be configured by using only the first reinforce 5A described above. In this case, a fragile portion such as a notch portion or a thin-walled portion may be provided in the first reinforce 5A, and this fragile portion may be used as a rigidity break point.
The rigidity break point is a portion where the rigidity of the reinforcement suddenly changes, and is a portion which becomes a starting point of bending deformation of the reinforcement when a load input of a predetermined value or more is applied from the rear side of the vehicle. However, according to the present invention, when the reinforcement is bent and deformed at the position of the rigidity break point, the battery (power storage device) can be rotated so as to be downward-sloping, and the position where the rigidity break point is provided is determined. As described above, in the front-rear direction of the vehicle, it is a portion corresponding to the rear end portion of the mounting area of the power storage device, or a portion closer to the rear of the vehicle approaching this portion.

The power storage device referred to in the present invention is not limited to various batteries, but also includes capacitors and the like. The vehicle to which the present invention is applied is not limited to a hybrid vehicle, but can also be applied to an electric vehicle or a general engine vehicle.

A Vehicle rear structure RP Rigidity break point S Battery mounting area Sa Rear end of battery mounting area 1 Vehicle compartment 18 Fuel tank 2 Floor 20 Recess 22 Bottom wall (concave)
3 Battery (power storage device)
4 Protective members 5A, 5B 1st and 2nd reinforce (reinforce)
6 Lower back panel 8 Floor cross member 81 Rear side member

Claims (2)

A recess that is provided on the floor inside the vehicle interior at the rear of the vehicle and is recessed downward,
A power storage device fixed on the bottom wall of the recess so as to be located in the recess.
A reinforce that is joined to the lower surface side of the bottom wall portion of the recess and extends from the rear portion of the bottom wall portion to the front side of the vehicle.
A floor cross member that is fixed so as to be bridged between a pair of left and right rear side members extending in the front-rear direction of the vehicle at a distance in the vehicle width direction at the rear portion of the vehicle and to which the front portion of the reinforce is joined.
The rear structure of the vehicle, which is equipped with
Of the reinforcements, a load that is provided at a portion of the reinforcement that coincides with the rear end of the mounting area of the power storage device or a portion that is closer to the rear of the vehicle and is greater than or equal to a predetermined value from the rear side of the vehicle. The rear structure of the vehicle is characterized by further provided with a rigid breaking point that enables the power storage device to rotate in a downward-sloping manner by serving as a starting point of bending deformation when an input is received. The vehicle rear structure according to claim 1.
A protective member fixed on the bottom wall portion of the recess and surrounding at least the front and rear and the upper side of the power storage device to protect the power storage device is provided.
A vehicle rear structure in which the lower back panel can come into contact with the protective member when the lower back panel at the rear of the vehicle rushes into the front side of the vehicle due to the load input.

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