JPH0512132Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention attaches a hollow resin bumper body to the front of the bumper reinforcement, and uses elastic deformation of the bumper body to absorb impact energy at the time of a collision. This invention relates to a vehicular bumper capable of absorbing water.

[Prior Art] Conventionally, as shown in FIG. 2, this type of vehicle bumper conventionally includes a metal bumper reinforcement 1 and a bumper reinforcement 1 that is attached to the front surface of the bumper reinforcement 1 with bolts 2. The bumper body 3 consists of a resin bumper body 3 having a hollow structure made by blow molding or the like, and the bumper body 3 has a stepped recess 31 along the longitudinal direction on the surface facing the bumper reinforcement 1 in order to improve shock absorption performance. (Utility Model Application No. 58-194942, Utility Model Application No. 61-
(See Publication No. 11449).

By the way, in a vehicle bumper having such a configuration, when an impact force is applied to the bumper body 3 at the time of a collision, the outer shell portion 32 of the bumper body 3 excluding the surface in contact with the bumper reinforcement 1 first undergoes elastic deformation. However, when the impact force is large, the concave portion 31 is further elastically deformed through the outer shell portion 32 as shown by the two-dot chain line in FIG. 2, and absorbs the impact energy in stages. At this time, an excessive tensile load is applied to the inner surfaces of the upper and lower corners 33, 33 of the bumper body 3 on the bumper reinforcement 1 side, which correspond to the base of the outer shell portion 32, and these parts are plastically deformed and cracks occur. There was a problem that arose. FIG. 3 is an enlarged view of section A in FIG.
It can be seen that the amount of deformation is large locally. When the corner portion 33 is plastically deformed,
The shape will not be restored and the bumper body 3 will not be able to be reused.

Note that to prevent this, it is possible to increase the radius of curvature of the corner portion 33, but increasing the radius of curvature of this portion is not preferable because it impairs the sense of unity with the vehicle when it is attached to the vehicle.
In other words, modern vehicle bumpers account for an important weight in appearance, and various design considerations have been made to improve the sense of unity with the vehicle. It cannot be done.

If the radius of curvature of the corner portion 33 is small, when the bumper body 3 is blow-molded, the corner portion 33
3 has a thick wall and is even more disadvantageous in terms of conditions.

[Problems to be solved by the invention] This invention was made in view of the above-mentioned problems. When the hollow structure bumper body is elastically deformed, the upper and lower corners of the bumper body on the bumper reinforcement side undergo plastic deformation. It is an object of the present invention to provide a bumper for a vehicle that does not cause cracks due to deformation and has an excellent appearance.

[Means to solve the problem] The measures taken to achieve the above purpose are as follows:
As shown in the figure, the upper and lower corner portions 33, 33 of the bumper main body 3 on the side of the bumper reinforcement 1 are each inwardly stepped and formed to have three continuous small corner portions.

[Operation] When an impact force is applied to the bumper body 3, the outer shell portion 32 is elastically deformed to protrude vertically as shown by the two-dot chain line in FIG. 1, and the bumper reinforcement 1 side of the bumper body 3 is Upper and lower corner parts 33, 33
A tensile load acts on the inner surface of each. In this invention, the upper and lower corner portions 33, 33 are each inwardly stepped and formed to have three continuous small corner portions A, B, and C, so that the tensile load is applied to each of the small corner portions A, B, and C. 1, as before.
Not concentrating on one spot. Therefore, the amount of deformation of the upper and lower corner portions 33, 33 can be suppressed within an allowable range, and no cracks will occur in the upper and lower corner portions 33, 33 due to plastic deformation.

After the shock is absorbed by the elastic deformation of the outer shell portion 32, the shape of the outer shell portion 32 including the upper and lower corner portions 33, 33 is restored by the elastic restoring force.

[Example] Hereinafter, an example of this invention will be described in detail with reference to the drawings.

FIG. 1 shows an enlarged sectional view of the main parts of the vehicle bumper according to the invention, corresponding to FIG. 3, in which 1 is a bumper reinforcement, 2 is a bolt, and 3 is a bumper body. Since the configuration is the same as the conventional one shown in FIG. 2, the explanation will be omitted.

In this invention, the bumper body 3 has upper and lower corner portions 33, 3 on the side of the bumper reinforcement 1.
3 has three consecutive small corner portions A, B, and C each having a small radius of curvature and are stepped inwardly.

Note that the resin bumper body 3 having a hollow structure is generally formed by blow molding, but it is also possible to construct a hollow structure by joining two pieces that are injection molded in two parts, which changes the gist of this invention. Various changes are possible within the scope.

[Effects of the invention] As described above, this invention has a configuration in which the upper and lower corners of the bumper reinforcement side of the hollow resin bumper body are each inwardly stepped and formed into three continuous small corner parts. As a result, when an impact force is applied to the bumper body and the outer shell portion is elastically deformed to protrude vertically, the tensile load that acts on the inner surface of the upper and lower corners is dispersed to the three small corners of the upper and lower corners. Unlike conventional products, cracks do not occur at the upper and lower corners due to plastic deformation, and therefore the resiliency is high, and the radius of curvature of the three small corners at the upper and lower corners can be reduced, resulting in an excellent appearance. There is.

Furthermore, the three consecutive small corner parts created by inward step molding of the upper and lower corners have good moldability even if the radius of curvature is small, and the upper and lower corners become thick when blow molding. There is an effect that can be avoided.

[Brief explanation of the drawing]

FIG. 1 is an enlarged sectional view of main parts corresponding to FIG. 3 showing one embodiment of a vehicle bumper according to this invention, and FIG.
The figure is a cross-sectional view of a conventional vehicle bumper, and FIG. 3 is an enlarged cross-sectional view of section A in FIG. 2. 1...Bumper reinforcement, 3...Bumper body, 32...Outer shell portion, 33...Corner portion, I, Ro, Ha...Small corner portion.

Claims (1)

[Scope of utility model registration request] A bumper for a vehicle consists of a bumper reinforcement and a hollow resin bumper body attached to the front of the bumper reinforcement, and absorbs shock through elastic deformation of the bumper body. A bumper for a vehicle, characterized in that the upper and lower corner portions of the bumper reinforcement side of the main body are each stepped inwardly to form three continuous small corner portions.