The invention discloses a triangular connecting rod-toggle rod transmission mechanism with a large force
magnification ratio for a
servo press. The mechanism comprises a
servo motor, an upper pin shaft, an upper toggle rod, a triangular connecting rod, a
crank, a middle pin shaft, a lower toggle rod, an unloading oil cylinder and an ejecting oil cylinder, wherein the output shaft of the
servo motor is connected with the
crank through a transmission mechanism; the
crank is connected with the connecting rod; the connecting rod is connected with the upper toggle rod and the lower toggle rod respectively; the upper toggle rod is hinged and fixed on the
machine body; the lower toggle rod is connected with a slider capable of linearly reciprocating up and down along a guide rail of the
machine body through a wedged overload protection block and the unloading oil cylinder; the upper toggle rod and the lower toggle rod have different lengths and are asymmetric; and the connecting rod is triangular. As symmetric toggle rods are changed into asymmetric toggle rods, and a linear connecting rod is changed into the triangular connecting rod, a relatively large force
magnification ratio is obtained, the drive torque required by the crank is remarkably reduced, and the capacity and cost of the servo motor are reduced under the condition of guaranteeing compact structure of the
machine body, enough
stroke of the slider and monotonous descending of the slider.