Underactuated Spatial Mechanism of Vehicle Door Latch with Force Constraint

Abstract

Aiming at less space occupation，efficient driving and high-end multi-function of the door latch release branch chain，the type synthesis of single loop spatial mechanism is carried out，and the RRRSR mechanism which could realize power release is obtained. In order to meet the requirements of manual release motion compatibility of the power release branch chain，the RRSSR underactuated mechanism is obtained by reducing the kinematic pair constraints of RRRSR mechanism，which make the mechanism have the motion compatibility with other branch chains. By adding a torsion spring force constraint to the kinematic pair of the mechanism，the flexibility and stability of the mechanism are ensured. The dimension of equation variables is reduced by projection in a specific direction，and the kinematic equation variables of the spatial RRRSR mechanism are minimized，and the relationship between input angle and output angle is obtained analytically. The Adams simulation results show that the RRSSR underactuated mechanism with force constraint can not only complete the power release process，but also has the motion compatibility adaptability under the condition of manual release.

Keywords

• Vehicle door latch;Type synthesis of spatial mechanism;Underactuated mechanism;Dynamics simulation