Injection molded thermoplastic integrated front end reinforcement and method of making same

Abstract

A vehicle body front end preassembly and method of making a vehicle front end assembly is disclosed. The vehicle body front end preassembly includes a frame to which an integrated front end module formed by an injection molding process is secured. The integrated front end module extends transversely across the vehicle and is provided with a plurality of fastener receptacles that are integrally molded as part of the integrated front end module. A plurality of reinforcement ribs are integrally molded as part of the integrated front end module. Unpainted body panels are secured to some of the fastener receptacles. The frame, injection molded integrated front end module, and body panels are then hot dipped in an electro-coating bath. According to the method of the present invention, the integrated front end module is injection molded to include integrally molded fastener receptacle and integrally molded reinforcement ribs that are injection molded from a fiber reinforced thermoplastic polymer. A partially assembled vehicle body is provided that has partially unattached body panels that are secured to the frame. Unattached body panels are secured to the integrated front end module. The preassembly is then immersed in an electro-coat bath, painted and then baked in a paint oven.

Description

TECHNICAL FIELD [0001] The present invention relates to injection molding an integrated front end reinforcement for a vehicle. BACKGROUND ART [0002] Many components are assembled to the front end of a vehicle that require precise alignment and durable mounting mechanisms. Headlights, parking lights, a decorative grill and a radiator are parts that may be attached directly or indirectly to a grill opening reinforcement. Grill opening reinforcements have been found to be helpful in tying together such components with the forward section of front fenders and the frame of a vehicle as it is being assembled. [0003] Other integrated front end modules that support other parts include bumper reinforcements, radiator supports, and inner fender reinforcements. These parts are relatively large and must maintain close tolerances for critical dimensions to meet strict fit and finish standards. [0004] Grill opening reinforcements and other integrated front end modules have traditionally been manu...

AI Technical Summary

Benefits of technology

The present invention provides a method for making a vehicle front end assembly with an integrated front end reinforcement module. This module includes fastener bosses, fastener receptacles, and reinforcement ribs made of fiber reinforced thermoplastic polymer. The method involves molding the front end reinforcement panel and then attaching it to a frame to form a basic vehicle body / frame pre-assembly. The pre-assembly is then immersed in an electro-coat bath and painted before being assembled with unpainted body panels, brackets, and other components to form the vehicle body. The use of fiber reinforced thermoplastic polymer reduces labor and tooling costs and improves fit and finish. The grill opening reinforcement is stable even after heating and paint baking. The method also reduces weight and scrap compared to traditional methods.

Problems solved by technology

Metal integrated front end modules are heavy and add to the overall vehicle weight.

Being formed in multiple pieces, metal integrated front end modules require labor intensive assembly operations.

Also, the SMC process is relatively slow requiring a large number of mold cavities to manufacture parts on a production basis.

In normal vehicle assembly operations, vehicle subassemblies are subject to electro-coating at temperatures in excess of 450° F. and after painting vehicle subassemblies are cycled through paint drying ovens where they are exposed to temperatures in excess of 200° F. Prior attempts to utilize injection molded thermoplastic parts that are attached to automobile vehicle bodies prior to electro-coating and paint drying oven exposure have been unsuccessful when attempted with large parts such as grill opening reinforcements and other large integrated modules.

Exposure of large weight bearing parts to high temperatures results in a loss of dimensional stability since the weight of parts attached to injection molded parts causes the injection molded parts to sag.

This results in poor fit and finish and difficulties in assembling components after being exposed to high temperatures.

Images