Design of Compliant Bistable Mechanism for Rear Trunk Lid of Cars

In traditional rear trunk lid designs, extra devices (e.g., hydraulic actuators and spring mechanisms) are employed to compensate the lid weight and reduce the efforts for both opening and closing it. Such devices often consist of a number of parts, thus leading to high costs for manufacture, assembly and maintenance. In this paper, we designed a compliant bistable mechanism to keep the lid’s two states and compensate the lid weight, which leads to a system that requires only a small input force to switch between the two states. In the design, the pseudo-rigid-body model (PRBM) was employed to model the compliant mechanism, a particle swarm optimizer was used to optimize the PRBM parameters, and promising results were presented and discussed. The use of complaint mechanism can lead to reduction of the costs for manufacture, assembly and maintenance.