Abstract: A theoretical analysis of negative rear angle locking toggle mechanisms was carried out.Through actual measurement of the displacements of cross heads and movable templates, the displacement, velocity and acceleration of the locking mechanism were realtimely analyzed.It showed that the ratio of mold moving to the cylinder speed was related to the parameters of the clamping mechanism.Actual measurement and theoretical estimation were in good agreement.The opening and closing characteristic was excellent.

Key words: negative rear angle, clamping mechanism, motion relationship, speed