Abstract
Keywords - Bumper, Spoiler, Gas Assisted Injection Moulding, Pedestrian Protection,
Weight reduction.
Abstract - This paper wants to show the R+D work developed together by: F. ASCAMM and PHIRA, in collaboration with ASCAMM Plus ST and APPLUS+ IDIADA. The idea (which has already been patented) is to obtain a new concept of cars bumper. The target is to get a front vehicle bumper incorporating an integrated gas channel with structural properties, with the aim of reducing or eliminating internal reinforcing elements.
The idea here presented is focused in reducing the cars weight and cost through the integra-tion of multiple parts in a single one. Under the bumpers aesthetic skin, the majority of automobiles assemble different parts oriented to absorb impacts. For small impacts or collisions parts called plastic absorbers do this function. To greater impacts the own cars structure and the denominated reinforcing beams receive the energy absorption.
The reinforcing beams (generally made of sheet metal) and the plastic absorbers are manufac-tured independently, and later assembled by the systems supplier. The new bumper presented pretend to integrate the above-mentioned elements in a single part, by means of a single tool (GAIM mould) and in a single injection shot. This concept is possible thanks to the application of an injection technology called GAIN/GAIM: Gas Assisted Injection Moulding. That type of process allows the creation of a great closed internal gas channel in the bumpers skin during its injection cycle. This channel improves the stiffness of the bumpers cross-section and thus allows reducing or eliminating the above-mentioned internal reinforcing elements.
The project status is the following: the firsts GAIM bumper prototypes have been injected successfully, being able to validate the application of this technology in a piece of those dimensions. Two crash test have been simulated: the RCAR (Allianz) and the Lower Leg-form (Pedestrian Protection) in order to see the behaviour of the new bumper in these conditions. The Chrysler Neon free FEM has been used to avoid any problems of confidentiality. In the first test (RCAR), there was no improvement due to the initial Neons front module poor behaviour in crash tests. However, it exists the possibility of including injected foam in the space hollowed by the GAIM bubble, in order to improve the energy absorbing capability of the new concept. Regarding the Pedestrian Protection test (Lower Legform) the results have showed a significant improvement in including the GAIM Bubble in the Spoiler area. All the critical measurements (Tibia deceleration, knee deflection and Shearing displacement) have had better values than the Neons initial design.
In conclusion, after the successfully industrialization of the new GAIM bumper and the good results of crash simulation (specially in pedestrian protection), there is a big opportunity to implement the idea in a new vehicle design, involving an OEM or a Tier One.
In addition, the expertise and knowledge acquired from the GAIM bumper application will be a great-derived benefit of this project to extend the idea to other vehicle components, re-designing them with the GAIM concept.