JPS60189659A - Plastic bumper - Google Patents

Abstract

PURPOSE:To keep up impact strength in a bumper without entailing any drop in its deposition characteristic as well as to prevent any damage even in time of a light collision, by installing each concave part in a setting flange of a reinforce of a plastic bumper and also top and bottom walls of a bumper outer cover. CONSTITUTION:On an inner side wall surface 101 of both top and bottom setting flanges 10b and 10c of a bumper reinforce 10, there are provided with plural concave parts 11 over the whole width of these setting flanges at regular intervals. On an outer side wall surface 201 of a spot where these setting flanges 10b and 10c of the bumper reinforce 10 of a bumpter outer cover 20, there are provided with plural concave parts 21 like in case of the inner side wall surface 101 of these setting flanges 10b and 10c. These concave parts 21 are installed in a position corresponding to a general part 12 of the said setting flanges 10b and 10c.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Industrial Field of Application The present invention relates to bumpers for vehicles, and particularly to resin bumpers.

(2) Background of the technology Generally, vehicles are equipped with bumpers to prevent damage to the vehicle in the event of a collision.In recent years, from the perspective of reducing the weight of vehicles, bumper reinforcement has been improved by replacing the bumper skin with There are also some that use a resin pamba made of resin.

There is one shown in Utility Model Application Publication No. 56-135338. As shown in Figures 1 and 2, some of this type are made of engineering plastic such as polycarbonate resin that extends in the vehicle width direction, and have mounting flanges LB on the top and bottom.
, lc and a substantially U-shaped bumper reinforcement 1 in cross section.
and a bumper skin 2 which is made of the same resin as the bumper reinforcement 1 and has a substantially U-shaped cross section, which is welded and bonded to the bumper reinforcement 1 so as to cover it. Some have a structure in which a shock absorber is placed between them.

And this Kizukito (Nba B is Panpan Inforce 1)
The upper and lower mounting flanges 1b', 1c are brought into contact with the inner end of the bumper skin, and are welded and integrated by means such as vibration welding or hot plate welding. Even if the Pan Pan Inforce 1 was completely welded, the strength of the welded portion and the thicker portion would be low, and there was a problem that the thicker portion would be damaged in the event of a light collision.

This is because the impact strength of the material changes depending on the thickness of the material.
If the thickness exceeds a certain value, the impact strength will drop significantly, so the thickness of the part where the end of the bumper skin 2 and the mounting flanges lb and 1c of the Pan Pan Inforce 1 are welded (indicated by d in Fig. 2) is this. This is because if the thickness exceeds a predetermined value, the welded portion will have lower impact strength than other thinner portions. (FIG. 6 is a reference graph showing experimental values showing the thickness dependence of the Fizot impact strength of polycarbonate).

However, in order to solve this problem, if the thickness of the welded portion of the bumper skin and the mounting flange was made thinner than the other portions, there was a problem that the welding could not be completed completely due to insufficient rigidity.

(4) Purpose of the invention This invention was made in view of the above problems.
The purpose is to provide pan-pan in-force and bamba epidermal dissolution.

(5) Structure and object of the invention is to create a system consisting of a resin-made pan-pan reinforcement consisting of a vertical wall and upper and lower mounting flanges, and a resin-made bumper skin that has a substantially U-shaped cross section and covers the pan-pan reinforcement. This is achieved by providing a plurality of recesses that are thinner than the general portion over the entire width on the inner wall surface of the mounting flange of the bumper reinforcement, and on the outer wall surface of the bumper skin.

(6) Examples of the invention Next, embodiments of the present invention will be described based on the drawings.

It consists of a pan pan inforce 10 made of recarbonate resin and a sareta damper skin 2o made of polycarbonate resin. The Pan Pan Inforce 10 is formed with a vertical wall 10a, an upper mounting flange 1'Ob, and a lower mounting flange 10c in a substantially U-shaped cross section. A plurality of recesses 11 are provided on the inner wall surfaces 1o1 of the upper and lower mounting flanges 10b and 10c at predetermined intervals across the entire width of the mounting flanges. The four parts 11 are formed into a relatively gently tilted shape, and the thickness of the mounting flange in the recess 11 is about 4 times that of the other general part 12 (where the recess 11 is not provided).
It is formed to have a wall thickness of 0.

On the other hand, the bumper skin 2o has a substantially U-shaped cross section and is formed to cover the punching reinforcement 1o. At the edge of this skin, that is, on the outer wall surface 201 where the flanges 10b and 10c of the Bambare reinforcement 1o are welded, the mounting flange 10b is attached.
A recess 21 is provided in the same manner as the inner wall surface 101 of , , 10c. This recess 21 is located on the mounting flange 10.
It is provided at a position corresponding to the general portion 12 of the mounting flanges 10b and 10c, and has the same vertical shape as the recess 11 of the mounting flanges 10b and 10c. The area is approximately 40% of the area where the area is not provided.

The length of the four parts 21 in the front-rear direction is approximately the same as the recess 11 of the mounting flange 10c described above.

Therefore, when these bumper reinforcements 10 and bumper skin are welded, the shape is not flat, but the thickness is constant at any part in the vehicle width direction (see Figures 4 and 5), and the welded part The thickness D is 140
4, it is possible to maintain a wall thickness that does not cause a decrease in impact strength compared to parts other than the welded part, and
The thickness of the general part of the skin and reinforcement flange is the same as before, so the rigidity required for normal vibration welding and hot plate welding is ensured, and these shapes can be easily formed by injection molding. However, it does not become a cost amplifier.

(7) Effects of the invention: Four parts are provided on the upper and lower walls of the bumper skin, and the wall thickness is kept relatively small even at the welded part, so impact strength can be maintained without reducing weldability. This has the effect that even in the event of a light collision, damage will not occur from the welded part of the bumper skin and reinforcement.

■It is a sectional view along the line. FIG. 6 is a graph of experimental values showing the thickness dependence of the isot impact strength of polycarbonate, which is one of the engineering plastics.

10...Bumper reinforcement 10a...vertical wall 10b, 10e...Mounting flange 101...Inner wall surface of mounting flange 11... Recessed part of mounting flange 12... General part of installation 72 inches 20...Bumper skin 201...Outer wall of Bamba epidermis

Claims (1)

[Claims] A bumper reinforcement made of resin consisting of a vertical wall and upper and lower mounting flanges, a bumper skin made of resin that has a substantially U-shaped cross section and covers the damper reinforcement, and upper and lower mounting flanges of the bumper reinforcement. In the resin bumper formed by welding to the bumper skin, a plurality of recesses are provided in the inner wall surface of the mounting flange of the bumper reinforcement, which are thinner than the general portion, extending in the vehicle width direction;
A resin bumper characterized in that a recess is provided in a portion of the outer wall surface of the bumper skin that corresponds to the general portion where the recess of the flange is not provided.