Konceptgenerering av adaptiv kraftbegränsare

Sammanfattning: In an accident, some seatbelt is let out by the seatbelt retractor in the vehicle. This is done to minimize the chest pressure and for the occupant to correctly impact the air bag. In an adaptive load limiter (LLA) the force in the seatbelt could be changed between different levels. In this way the chest pressure and the speed in to the air bag can be optimized and to minimize injuries.The work has been aimed at develop new concept of switching between the high and low force. The goal is to reduce the number of parts, the complexity and the size of the components. The LLA device today is made out of nine components.This work has included brainstorming for ideas of new concepts. The concept have been sketched. The three best concepts have been valued in a concept evaluation matrix. CAD- models have been done. Calculations have been done by hand to see which forces the components will be subjected to. FEM-calculations have also been done to see that components can handle the amount of stress they which they will be subjected to during the switching. Tests of components have also been made to verify the concept on Autolivs test center. The results were then evaluated. The work is ended by recommendations of further development.This thesis has been done on Autoliv Sweden AB in Vårgårda. Autoliv was founded in 1953 in Vårgårda of the two brothers Lennart and Stig Lindblad. Autoliv is world- leading in car safety. Autoliv is currently operating in 27 countries and has over 70 000 employees. They save over 30 000 lives and prevent over 300 000 injuries every year. Autoliv has made seatbelts since 1956.