GB2032575A

GB2032575A - Bumper structure

Info

Publication number: GB2032575A
Application number: GB7930781A
Authority: GB
Original assignee: Nissan Motor Co Ltd
Current assignee: Nissan Motor Co Ltd
Priority date: 1979-09-05
Filing date: 1979-09-05
Publication date: 1980-05-08
Also published as: GB2032575B

Abstract

A bumper structure supported on a car body (C) by stays (8) comprises a bumper (B) made of synthetic resin, rubber or metal and a stop member (2) made of synthetic resin or rubber, and provided at the central portion of the bumper. The surface (3) of the stop member (2) on the car body side contacts or is positioned close to a rigid portion (4) of the car body. By use of the stop member (2), an external load due to collision is sustained by the rigid portion (4) of the car body and absorbed by the resilient deformation of the stop member (2) without damaging the car body. Large scale deformation of the bumper (B) is also prevented. <IMAGE>

Description

SPECIFICATION Bumper structure The present invention relates to a bumper structure, and particularly to a bumper structure which sustains large scale deformation within a resilient limit.

According to the prior art as shown in Fig. 1, a bumper B is mounted on the front and rear ends of a car body C, respectively, by a pair of bumper stays 8 fixed to corresponding side members 7 extending the length of the car body. However, in the bumper B according to the prior art, when the bumper, formed of, e.g. rubber, synthetic resin such as, for example, polypropylene, fiberglassreinforced plastic, polyvinyl chloride or the like is deformed within its resilient limit by an external load P due to collision or contact with another vehicle, its most vulnerable portion 1 is normally the central portion 9 of the bumper which is situated between the pair of bumper stays 8. For this reason, the central portion 9, or the most vulnerable portion of the bumper, is deformed within a resilient limit by the external load P as shown by the phantom line in Figs. 1 and 2.As a result, the central portion 9 contacts and deforms both the rear upper and lower panels 11 and 12 which form the front and back of the car body C respectively, depending on which end of the car collides, thereby damaging same.

It is an object of the present invention to provide an improved bumper structure in which the problems encountered by the bumper according to the prior art are solved.

It is another object of this invention to provide an improved bumper structure in which a stopper member is provided on the inner surface of the most vulnerable portion of the bumper in order to prevent large scale deformation while absorbing the external load.

It is still another object of this invention to provide an improved bumper structure in which a stopper member is provided on the inner surface of a bumper which prevents large scale deformation while absorbing the external load, and by the aid of that portion of the car body having high rigidity.

In accordance with the present invention, there is provided a bumper structure having a pair of bumper stays firmly fixed to a car body, comprising; a bumper provided with a stopper member, one surface of which is attached to a portion of the inner surface of said bumper and positioned between said bumper stays for preventing large scale deformation of said bumper in the direction of said car body, the opposed surface of said stopper member being in contact with, or disposed close to, a corresponding portion of said car body having high rigidity.

These objects, advantages and features of the present invention will be apparent from the following description in conjunction with the accompanying drawings.

Fig. 1 is a plan view of the rear portion of a car body provided with a bumper according to the prior art; Fig. 2 is a cross-sectional view taken along the line Il-Il in Fig. 1; Fig. 3 is a plan view of the rear of a car body provided with a bumper according to the present invention: Fig. 4 is a cross-sectional view taken along the line IV--IV in Fig. 3; Fig. 5 is a cross-sectional view taken along the line V-V of Fig. 4; Figs. 6 through 9 are views, similar to Fig. 5, of modifications of the present invention; Fig. 10 is a cross-sectional view, similar to Fig.

4, of a second embodiment of the bumper according to the present invention; Fig. 11 is a cross-sectional view, similar to Fig.

4 of a third embodiment of the bumper according to the present invention; and Fig. 12 is a cross-sectional view, similar to Fig.

4, of a modification of the third embodiment of the bumper according to the present invention.

Referring to Fig. 3, there is shown a bumper B according to the present invention, which is formed of rubber, synthetic resin such as, for example, polypropylene, fiberglass-plastic, polyvinyl chloride or the like. The bumper B is supported at the rear of a car body C by a pair of bumper stays 8 fixed to a pair of side members 7 extending the length of the car body C. The bumper B is formed integrally with a stopper member 2, of the same material as the bumper, at the rear of its central portion 9 which is situated between the pair of bumper stays 8. The surface 3 of the stopper 2 is disposed close to, or in contact with, a rear portion 4 of the car body which has high rigidity and reinforced by a cross member 13 secured to the rear ends of respective side members 7.

In the first embodiment shown in Figs. 4 and 5, the stopper 2 consists of a number of parallel bars 5 hexagonal in cross-section as shown in Fig. 5 and the surface 3 of the stopper 2 which is formed by an assembly of end surfaces of these bars 5 is arranged so as to come into face-to-face contact, or be in close disposition with, the rigid portion 4 between the upper and lower rear panels 11 and 12 which form the rear portion of the car body C.

In this embodiment, the rigid portion 4 is an upper portion of the lower rear panel 1 2 which is improved in strength by mounting the cross member 1 3 onto the rear ends of the side members 7.

As described above, the stopper 2 consists of a plurality of parallel bars 5 of hexagonal crosssection, but bars 5, rectangular or circular in crosssection as shown in Figs. 6 and 7, may also be used.

Moreover, the stopper 2 may also consist of a plurality of strips 6 which extend in the horizontal or vertical directions as shown in Figs. 8 and 9.

Due to the above formation, the stopper 2 can absorb and divert the external load P exerted on the bumper B. The stopper 2 can also prevent possible large scale deformation at the most vulnerable portion 1 of the bumper B, while the surface 3 of the stopper 2 can be maintained in contact with the surface of the rigid portion 4.

Consequently, according to the first embodiment, the central portion 9, which suffers large scale deformation, begins deforming when the external load P due to a collision is exerted thereon and the surface 3 of the stopper 2 formed by the bars 5 at the rear of the central portion 9 comes into contact with the rigid portion 4 of the rear panels 11 and 12, with the result that the stopper 2 absorbs the external load P by resiliently deforming and as the load P is exerted overall on the rigid portion 4, the load P is distributed accordingly. Consequently, the central portion 9 of the bumper B is prevented from violently striking the rear panels 11 and 12.In this case, the external load P is exerted on the rigid portion 4 with a low surface pressure due to the surface 3 of the stopper 2, so that the rear panels 11 and 12 are prevented from being partially deformed and/or prevented from having their painted surfaces damaged, as in the case of the conventional bumper B shown in Figs. 1 and 2.

The bumper B according to the present invention returns to its original state immediately the resilient deformation of the stopper is restored.

Fig. 10 shows a second embodiment of the bumper B according to the present invention which comprises a plurality of mounting legs 1 5 which are formed on the back of the most vulnerable portion 1, that is, the portion which is subject to large scale deformation of the bumper B. The stopper 2, made of synthetic resin such as specified above as materials for the bumper, rubber or the like, is mounted over the legs 1 5 as a separate member, the surface 3 of the stopper 2 -being formed flat so as to abut against, or be positioned close to, the rigid portion 4 of the car body C. As mentioned heretofore, the surface 3 of the stopper 2 is formed flat, but it may also be formed so that its surface conforms to the surface configuration of the rigid portion 4 of the car body C.

Also, in the second embodiment described above, the external load P is absorbed by the resilient deformation of the stopper 2 as in the case of the first embodiment, and is sustained overall by the rigid portion 4 of the car body C.

Figs. 11 and 1 2 respectively show a crosssectional view of the third embodiment of the bumper B according to the present invention. In this embodiment, the bumper B is made of a metal and the stopper 2, formed of a resin, rubber, or the like such as mentioned above is provided at the back of the most vulnerable portion or the portion which is subject to large scale deformation.

The stopper 2 shown in Fig. 11 is fitted in the bumper B with upper and lower bent portions 17, 1 8 of the bumper B being fitted into receptive grooves 1 6 provided on the upper and lower legs of the stopper 2 so as to be fixed to the bumper B.

The stopper 2 is provided at its center with å pressure receiving portion 1 9 which extends to contact the inner surface of the bumper B. The stopper 2 shown in Fig. 12 is mounted in the bumper B in the same way as the stopper 2 in Fig.

11. In this case, as in the first embodiment, a plurality of bars 5 project from the inner surface of the bumper B to form the surface 3 of the stopper 2 which is an assembly of the end surfaces of the bars.

Accordingly, the stopper 2 made of the resilient material is mounted onto the back of the most vulnerable portion 1 or the portion which is subject to the largest scale of deformation of the metal bumper B. As in the first embodiment described above, the external load P is absorbed by the resilient deformation of the stopper 2 and is sustained overall by the rigid portion 4 of the car body C when the external load P is exerted.

As a result, damage to the car body by large scale deformation of the bumper without damage to the bumper itself is completely prevented.

Moreover, in each embodiment described above, description has been made of the case where the most vulnerable portion, or the portion subject to the largest scale of deformation, is t'h, central portion of the bumper situated between the bumper stays. However, in the case of a bumper whose bumper side is not fixed to the car body, this bumper side is also a portion which is subject to large scale deformation so that the present invention is applicable to this case as well as the embodiments described above.

Furthermore, in the above embodiments, deseription has been made as to the rear bumper, but it should be noted that the invention is applicable to the front bumper as well. In this case, one of the portions of the car body having high rigidity is a front pane! apron positioned in front of a radiator core support.

Claims

1. A bumper structure having a pair of bumper stays firmly fixed to a car body, comprising; a bumper provided with a stopper member, one surface of which is attached to a portion of the inner surface of said bumper and positioned between said bumper stays for preventing large scale deformation of said bumper in the direction of said car body, the opposed surface of said stopper member being in contact with, or disposed close to, a corresponding portion of said car body having high rigidity.

2. A bumper structure as claimed in claim 1, wherein said stopper member is made of a synthetic resin.

3. A bumper structure as claimed in claim 1, wherein said stopper member is made of rubber.

4. A bumper structure as claimed in claim 1, wherein said bumper is made of synthetic resin and said stopper member is integrally formed therewith.

5. A bumper structure as claimed in claim 1, wherein said bumper is made of metal.

6. A bumper structure as claimed in claim 1, wherein said stopper member is separately formed from said bumper.

7. A bumper structure as claimed in claim 1, wherein said stopper member comprises a plurality of bars respectively, having a hexagonal shape in cross-section.

8. A bumper structure as claimed in claim 1, wherein said stopper member comprises a plurality of bars respectively, having a circular shape in cross-section.

9. A bumper structure as claimed in claim 1, wherein said stopper member comprises a plurality of bars respectively, having a rectangular shape in cross-section.

10. A bumper structure as claimed in claim 1, wherein said stopper member comprises a plurality of strips extending in the vertical direction.

11. A bumper structure as claimed in claim 1, wherein said stopper member comprises a plurality of strips extending in the horizontal direction.

12. A bumper structure as claimed in claim 1, wherein said stopper member comprises a plurality of strips extending in the diagonal direction.

13. A bumper structure as claimed in claim 1, wherein the surface of the said stopper member is formed in a shape which conforms to the surface of said portion of said car body having high rigidity.

14. A bumper structure substantially as described with reference to, and as illustrated'in, Figs. 3 to 5, or Figs. 3 to 5 as modified by any of Figs.6to 9, or Fig. 10, or Fig. 11,orFig. 12,ofthe accompanying drawings.