JPH11348691A - Front part structure of car body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the front part structure of a car body capable of coping with increased sizes of bamper reinforcement and energy absorption without increasing in weight and size. SOLUTION: A side member 20 is extended in the longitudinal direction of a car body, both the end parts of a bamper reinforcement 14 extended in the car width direction, are mounted to each front end part of the side member 20, and an energy absorbing material 16 is set at the front side of the bamper reinforcement 14. A cut-down part 20a receiving at least a part of the bamper reinforcement 14 is formed at the upper end of the front end part of the side member 20, and the bamper reinforcement 14, received by the cut-down part 20a, is mounted to the side member 20 in a interposed state as viewed along the longitudinal direction F-R of the car body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle body front structure, and more particularly, to a vehicle body front structure in which an energy absorbing material is installed on a front side of a bumper reinforcement.

[0002]

2. Description of the Related Art Conventionally, as a vehicle body front structure of this kind,
For example, there is one described in JP-A-5-213123. In such a conventional vehicle body front structure, at a front end portion of a side member extending in the vehicle front-rear direction on both sides of the vehicle body, an inner mounting bracket is joined to an inner side surface portion, and an outer mounting bracket is joined to an outer side surface portion. I have. Then, the mounting flanges of the inner mounting bracket and the outer mounting bracket, and the side surfaces of the bumper reinforcement extending in the vehicle width direction are overlapped and connected by bolts and nuts. In addition, an energy absorbing material is provided in front of the bumper reinforcement so as to absorb a shock in a light collision.

[0003]

In such a conventional structure, when it is necessary to increase the size of the bumper reinforcement or the energy absorbing material in response to an increase in the weight of the vehicle, the length of the side member is reduced. Minutes or
Alternatively, the total length of the vehicle is lengthened. However, when the length of the side member is reduced, it is necessary to increase the thickness of the side member or to add a reinforcing member for the side member in order to maintain energy absorption characteristics at the time of a collision at a medium speed or more. There is a problem that the cost is increased and the weight is further increased. In addition, there is a problem that even if the overall length of the vehicle is increased, the weight is further increased, which has a great effect on the merchantability.

The present invention has been made in view of such problems, and the inventions according to claims 1 to 7 can cope with an increase in the size of a bumper reinforcement and an energy absorbing material without increasing the weight. It is an object of the present invention to provide a vehicle body front structure that can be used.

[0005]

In order to achieve the above object, the invention according to claim 1 of the present invention is directed to a bumper reinforcement in which side members extend in the longitudinal direction of the vehicle body on both sides of the vehicle body and extend in the vehicle width direction. Are attached to the front ends of the side members on both sides, respectively, and the energy absorbing material is installed on the front side of the bumper reinforcement.A part of the front end of the side member includes a bumper reinforcement. A cut-off portion that receives at least a part is formed, and the bumper reinforcement is attached to the side member in an overlapping state when viewed along the vehicle front-rear direction by being received by the cut-off portion. I do.

According to a second aspect of the present invention, in the first aspect, the front end of the portion where the cut-off portion of the front end of the side member is not formed extends forward to near the front end face of the bumper reinforcement. It is characterized by being elongated. According to a third aspect of the present invention, in the first or the second aspect, the front end of the front end of the side member where the cut-out portion is not formed is slightly rearward from the front end surface of the bumper reinforcement. It is characterized by extending to a position.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the cut-off portion of the side member is formed at the upper end or the lower end of the front end of the side member. Features. Claim 5
According to the invention described in claim 4, the cut-off portion of the side member is formed at the upper end of the front end of the side member, and the bumper reinforcement is placed on the cut-off portion before mounting and temporarily It is characterized by being retained.

According to a sixth aspect of the present invention, there is provided the vehicle body as defined in the fourth or fifth aspect, wherein the cutaway portion of the side member is formed from the uppermost edge or the lowermost edge of the upper end or the lower end respectively. An extended portion extending forward and overlapping the bumper reinforcement is formed. According to a seventh aspect of the present invention, in the first aspect of the present invention, the bumper reinforcement is connected to the side wall of the side member and extends substantially in the front direction in the vehicle body. An elongated brace is provided.

[0009]

According to the first aspect of the present invention, the cut-out portion of the side member receives the bumper reinforcement, whereby the bumper reinforcement moves along the vehicle longitudinal direction with respect to the side member. By being mounted in an overlapping state, the bumper reinforcement or the energy absorbing material can be enlarged by an amount corresponding to the overlapping. Even if these become large, there is no need to shorten the side members,
Energy absorption characteristics at the time of a frontal collision can be maintained without increasing the weight of the side members.

According to the second aspect of the present invention, in addition to the effect of the first aspect, the front end of the portion of the front end of the side member where the cutout portion is not formed is formed by the front end face of the bumper reinforcement. By extending forward to the vicinity, the front end of the side member can be crushed at the time of a frontal collision, and the collision energy can be efficiently absorbed. According to the third aspect of the invention, in addition to the effect according to any one of the first and second aspects, the front end of the side member where the cut-off portion is not formed at the front end portion is formed.
By making it slightly behind the front end face of the bumper reinforcement, in a light collision, energy is absorbed by the deformation of the bumper reinforcement located ahead of the front end of the side member and the energy absorbing material. Therefore, damage to the side members can be prevented.

According to the fourth aspect of the present invention, in addition to the effects of any one of the first to third aspects, the cut-off portion of the side member is formed at the upper end or the lower end of the front end of the side member. The portion of the side member where the cutout portion is not formed is collected at the lower end or the upper end to secure the strength of this portion and to secure the absorbed energy at the time of a frontal collision. According to the fifth aspect of the invention, in addition to the effect of the fourth aspect, the bumper reinforcement can be placed on the cut-off portion and temporarily held before the mounting, so that the worker can perform the mounting at the time of mounting. There is no need to work while holding down the pampering reinforcement, and the working efficiency can be improved.

According to the sixth aspect of the invention, in addition to the effects of the fourth or fifth aspect, in addition to the uppermost edge or the lowermost edge of the side member, the side member extends in the forward direction of the vehicle body and overlaps with the bumper reinforcement. Since the extension portion is formed, the extension portion can hold down the bumper reinforcement, so that the burden on the worker to press the bumper reinforcement at the time of installation can be reduced, and work efficiency can be improved. it can. According to the seventh aspect of the present invention, in addition to the effect of any one of the first to sixth aspects, the bumper reinforcement is connected to the side wall of the side member and extends substantially in the forward direction of the vehicle body. Is provided, the brace corresponds to the side wall cut off at the cut-off portion of the side member, and the same strength as that obtained by using the side member having substantially no cut-off portion can be provided.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are views showing a first embodiment of a vehicle body front structure according to the present invention. In the drawing, reference numeral 10 denotes a bumper fascia constituting a bumper skin of a front bumper. A bumper reinforcement 14 extends in the vehicle width direction inside the bumper, and an energy absorbing material 16 is installed in front of the bumper reinforcement 14. ing. The energy absorbing member 16 is formed with a protrusion 16a projecting rearward at an appropriate position.
The energy absorbing member 16 is attached to the bumper reinforcement 14 by being inserted into a mounting hole provided on the front surface of the bumper 4.

The bumper reinforcement 14 is attached to the front end of the side member 20 at both ends in the vehicle width direction. The side member 20 is a strength member extending in the front-rear direction of the vehicle body on both sides of the vehicle body and having a closed cross-sectional structure. Have been. And the bumper reinforcement 14 is received so that it may be mounted on the cut-off part 20a. By attaching the mounting flanges 20c, 20c bent in the vehicle width direction and the back surface of the bumper reinforcement 14 on both sides of the cut-off portion 20a and fastening the bolts and nuts 21 together, the bumper reinforcement 14 is The member 20 is attached to the member 20 so as to overlap with each other when viewed along the vehicle front-rear direction FR. The front end of the portion 20b of the side member 20 where the cutout portion 20a is not formed extends to a position near the front end surface of the bumper reinforcement 14 and slightly behind the front end surface.

In the vehicle body front structure constructed as described above, the bumper reinforcement 14 is mounted on the side member 20 so as to overlap with the side member 20 when viewed in the vehicle longitudinal direction. The thickness of the material 16 or the bumper reinforcement 14 in the front-rear direction of the vehicle body can be increased, so that the energy absorption at the time of a light collision can be effectively performed. The same length as the thing can be secured. Therefore, at the time of a frontal collision at a middle speed or higher, the side member 20 is crushed in the axial direction, and energy can be efficiently absorbed. In order to clarify this effect, as shown in FIG. 3 (a), the bumper reinforcement 14 and the side member 20 were connected to the front and rear of the vehicle body as shown in FIG. 3 (b). Energy characteristics (FS curves) at the time of a frontal collision at a speed of 60 km / h were obtained for each of the cases where the length of the side member 40 was shortened instead of overlapping along the direction. FIG. 4 shows the results. In the present embodiment, the initial reaction force in the initial stage of the collision contributed by the joint between the bumper reinforcement 14 and the side member 20 is higher than that in the case of FIG. It can be seen that the energy absorption efficiency has improved. This is side member 2
Part 20b where no cut-out part 20a of 0 is formed
It is considered that the axial crush of the steel effectively contributed. As another reason, in the case of FIG. 3B, the input from the barrier is transmitted from the bumper reinforcement 14 to the upper side of the side member 20, so that the side member 20
In the present embodiment shown in FIG. 3A, the side member 20 may be broken in a mode other than the axial crush mode without a uniform force acting on the cross section. Portion 20b where portion 20a is not formed
Extends near the front end face of the bumper reinforcement 14, and receives the input from the barrier with the bumper reinforcement 14 and the portion 20b where the cut-out portion 20a is not formed. It is considered that the force acts and the side member 20 is surely crushed in the axial direction.

The front end of the portion 20b where the cut-out portion 20a is not formed is connected to the bumper reinforcement 14.
By extending forward to near the front end face of
The portion that contributes to energy absorption can be increased. However, by setting the front end of the portion 20b where the cutout portion 20a is not formed to be slightly behind the front end surface of the bumper reinforcement 14 as in the present embodiment, a low-speed collision can be achieved. ,
At the time of a so-called light collision, energy can be absorbed by deformation of the bumper reinforcement 14 and the energy absorbing material 16 located forward of the front end of the side member 20, and damage to the side member 20 can be prevented.

Further, as in the present embodiment, the cut-out portion 20a is formed at the upper end of the front end of the side member 20, and the length of the cut-off portion 20a in the vehicle longitudinal direction stabilizes the bumper reinforcement 14. If the bumper reinforcement 14 is long enough to be placed on the side member 20, the bolt nut 2
Before mounting in step 1, it can be placed on the cut-off portion 20a and temporarily held, thereby improving work efficiency.

In this embodiment, the cut-off section 2
Although 0a is formed at the upper end of the front end of the side member 20, the present invention is not limited to this, and it may be formed at the lower end of the front end of the side member 20, or may be formed at the middle part in the vertical direction. . Preferably, it is desirable to secure the strength by forming the cut-off portion 20a at the upper end or the lower end, and collecting the portion 20b where the cut-off portion 20a is not formed at either the lower end or the upper end.

FIG. 5 and FIG. 6 are views showing a second embodiment of the present invention. The same members as those in the first embodiment are denoted by the same reference numerals, and the detailed description thereof will be omitted.
In the second embodiment, the bumper reinforcement 24 is composed of two parts, a front reinforcement 24A and a rear reinforcement 24B.
The two parts 24A and 24B form a closed cross section, and a brace 22 is provided in the closed cross section, which is connected to the side wall of the side member 20 and extends substantially in the extension line toward the front of the vehicle body. This is different from the first embodiment. The brace 22 is joined to either the front reinforcement 24A or the rear reinforcement 24B (in this example, the rear reinforcement 24B), and then joins the front reinforcement 24A and the rear reinforcement 24B to each other. Thus, it is provided inside the reinforcement 24. By providing such a brace 22, the brace 22 corresponds to the side wall cut off at the cut-off portion 20a of the side member 20. Therefore, it is possible to provide the same strength as that using the side member 20 having substantially no cut-off portion 20a.

FIG. 7 is a diagram showing a third embodiment of the present invention. The same members as those in the first embodiment are denoted by the same reference numerals, and the detailed description thereof will be omitted. In this embodiment, an extended portion 20d extending in the vehicle front-rear direction is formed from the uppermost edge of the cutout portion 20a formed at the upper end of the side member 20.
Overlap with the bumper reinforcement 14. Extension part 20d is bumper reinforcement 1
Since the presser 4 is pressed from above, the temporary holding of the pampering reinforcement 14 at the time of attachment can be performed more reliably, and the working efficiency can be improved. In addition, the cutout portion 20 a is formed at the lower end of the side member 20. In this case, by extending the extending portion from the lowermost edge in the front-rear direction of the vehicle, the bumper reinforcement 14 can be temporarily held in the extending portion before mounting. This eliminates the need for the worker to work while holding down the pamper reinforcement during the mounting, and thus improves the working efficiency.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a first embodiment of a vehicle body front structure according to the present invention (a cross-sectional view taken along line 1-1 in FIG. 2).
It is.

FIG. 2 is a perspective view of a vehicle body front structure shown in FIG. 1;

FIG. 3A is a diagram illustrating a main part of the first embodiment, and FIG. 3B is a diagram illustrating a main part of a comparative example, and each illustrates a state in which a collision experiment is performed.

4 is a graph showing an energy characteristic (FS curve) at the time of a frontal collision at a speed of 60 km / h in FIG. 3, where the solid line is that of FIG. 3A and the broken line is that of FIG. 3B. Indicates the result.

FIG. 5 is a sectional view, corresponding to FIG. 1, showing a second embodiment of the vehicle body front structure according to the present invention. You.

FIG. 6 is a perspective view of the vehicle body front structure shown in FIG. 5;

FIG. 7 is a sectional view, corresponding to FIG. 1, showing a third embodiment of the vehicle body front structure according to the present invention. You.

[Explanation of symbols]

 14 Bumper Reinforcement 16 Energy Absorbing Material 20 Side Member 20a Cut-Out Part 20b Part Where Cut-Out Part 20a is Not Formed 20d Extension Part 22 Brace 24 Bumper Reinforcement

Claims (7)

[Claims] A side member extends in the front-rear direction of the vehicle body on both sides of the vehicle body, and bumper reinforcements extending in the vehicle width direction are respectively attached to front end portions of the side members on both sides, and energy is absorbed on the front side of the bumper reinforcement. In the vehicle body front structure in which the members are installed, a cut-out portion for receiving at least a part of the bumper reinforcement is formed at a part of the front end of the side member, and the bumper rain is received by the cut-off portion. The front structure of the vehicle body, wherein the reinforcement is attached to the side member so as to overlap with each other when viewed along the vehicle longitudinal direction. 2. The vehicle body front according to claim 1, wherein the front end of the portion of the side member where the cut-off portion is not formed extends forward to near the front end surface of the bumper reinforcement. Part structure. 3. The front end of the portion of the side member where the cut-off portion is not formed extends to a position slightly behind the front end surface of the bumper reinforcement. 2. The vehicle body front structure according to 2. 4. The vehicle body front structure according to claim 1, wherein the cut-off portion of the side member is formed at an upper end or a lower end of a front end of the side member. 5. A cut-off portion of the side member is formed at an upper end of a front end portion of the side member, and a bumper reinforcement is placed on the cut-off portion and temporarily held before mounting. The vehicle body front structure according to claim 4, wherein: 6. An extended portion is formed extending from the uppermost edge or the lowermost edge of the upper or lower end where the cut-off portion of the side member is formed to extend in the front direction of the vehicle body and overlap with the bumper reinforcement. The vehicle body front structure according to claim 4 or 5, wherein: 7. The bumper reinforcement according to claim 1, further comprising a brace connected to a side wall of the side member and extending substantially in an extension line toward the front of the vehicle body. The vehicle body front structure described in 1.