DE8320240U1 - Plastic bumper - Google Patents

Description

HOECHST AKTIENGESELLSCHAFT HOE 83 / F 132 G Dr.DA / mü plastic bumpers

More and more, bumpers on vehicles are made of thermoplastic materials Made of plastics. In addition to the corrosion resistance and the low weight, the Freedom of design together with ease of processing are the reason for using plastic bumpers .

The production takes place according to the known plastics processing methods such as pressing, injection molding and preferably in the extrusion blow molding process as a hollow body.

In the course of saving weight and material, attempts are made to keep the weight and thus the wall thickness of the bumpers as low as possible. However, because of their material strength, plastic bumpers are inferior to bumpers made of metal with the same or less wall thickness and no longer meet the EC standard. The EC standard stipulates that when a load of 1000 kg is applied at a speed of H km / h, a temporary deflection of a maximum of 40 mm may occur.

This requirement is met by plastic bumpers with approx. 2 to 3 mm wall thickness for economic reasons aspired is not fulfilled.

In order to still take advantage of plastic bumpers, these are provided with reinforcements made of metal or another material in or on the plastic body are attached or are made directly from a composite of plastic and metal.

A disadvantage of these constructions is that the reinforcement elements are irreversibly deformed when the force is exerted and thus the whole when a repair is carried out

Bumper, so plastic part with reinforcement, expensive and expensive to be replaced, although the plastic part would not be destroyed due to its resilience.

The object of the innovation is a bumper made of reinforced plastic, in which the plastic body and the reinforcement elements are releasably connected to each other.

The figures show a reinforced bumper according to the innovation. Figure 1 shows an enlarged section I-I through the bumper in a preferred form. FIG. 2 shows a view from the rear and FIG. 3 shows a plan view.

In Figure 1, the blown hollow plastic body (1) is with the undercuts (2) to recognize in which the

metallic reinforcement pipes (3) are resiliently engaged. The hollow body (1) is attached to the holder by means of inserts (4) (5) of the motor vehicle attached. The bumper contains one, but preferably two reinforcement tubes. 20th

Figure 2 shows the location of the inserts ⁽¹ O and Armierungsrohre (3) into the undercut (2) of the hollow body (1), wherein the undercuts (2) are preferably longer than the Armierungsrohre (3).
25th

Figure 3 shows that the undercuts (2) extend into the curves (1a) of the hollow body (1).

The plastic hollow body is made in an extrusion blow molding process manufactured. A nozzle with wall thickness regulation is used to convert a long tube-like preform into a corresponding blow molding tool using the inner or outer hose method by blowing compressed air over a Needle molded from the hollow bumper body (1) from plastic. During the blowing process are not on the vehicle visible side by appropriate formation of the blowing

Tool two longitudinally extending circular segment-like indentations (undercuts (2)) are formed, the opening lips of which have a smaller free passage than the diameter of the round indentation.
5

For later attachment to the Amierungsrohren are appropriately shaped in the blow mold in a known manner Metal inserts are inserted and firmly anchored in the plastic during the blow molding process.

The hollow bumper body produced in this way is over the undercuts snapped onto the reinforcement pipes attached to the vehicle and over the inserts to the bumper suspension attached.

In the event of a force acting on the bumper, the hollow body (1) deforms first. Is the force greater
the inserted reinforcement tubes (3) take over the load and deform. If the force is too great, it is

possible that the reinforcement tubes (3) are irreversibly deformed, while the actual bumper is made of plastic
can take its original shape again.

The easy interchangeability of the reinforcement elements then allows the cost-effective repair of damage.

Since the plastic bumper according to the innovation must have high rigidity and at the same time good flexibility in a wide temperature range, it is possible to use
Material for the blow molded plastic bumper preferably modified polypropylene.

Claims (2)

-1J- HOE 83 / F 132 G claims 1. Plastic bumper manufactured using the extrusion blow molding process for vehicles stiffened by a reinforcement of metallic materials, characterized in that, that the reinforcement attached to the vehicle body (3) into one during blow molding of the plastic hollow body (1) produced longitudinal undercut (2) is resiliently engaged. 2. Plastic bumper according to claim 1, characterized in that the reinforcement attached to the vehicle body consists of a steel tube (3) and the undercut (2) formed on the hollow plastic body (1) on its opening is smaller than the outer diameter of the pipe. 3- plastic bumper according to claim 1, characterized in that that the reinforcement attached to the vehicle body consists of two steel pipes (3) connected to one another and the plastic hollow body (1) has two longitudinally extending molded undercuts (2), the opening of which smaller than the outer diameter of the steel pipe ;? is.