The structural improvement of large precision punching machines. Currently, precision punching machines provide power through the uniform rotation of the crankshaft. This power transmission structure ensures the smooth operation of the slider during the working stage of precision punching machines. When manufacturing large specification and large stroke precision punching machines, it can only reduce the number of strokes, increase the transmission ratio, and even increase the number of gear transmissions, thereby limiting the improvement of precision punching machine productivity. To break through this limitation, only structural modifications can be made. However, the modification of large tonnage precision punching machines in the market has made the structure of the punching machine more complex and large, resulting in cumbersome maintenance and use in the later stage.
In order to fundamentally solve the problems of low stroke frequency, complex structure, and difficult maintenance of large tonnage precision punching machines, Weidman has adopted a new structure for large tonnage precision punching machines. The improved new large tonnage punching machine has a large gear, crankshaft, connecting rod, and slider inside its body. The eccentric pin shaft supporting the large gear is located on the body, and the crankshaft is fixedly connected to the connecting rod, and the connecting rod is hinged to the slider. There is also a connecting rod and a swing rod inside the body. There is a connecting rod pin on the large gear, one end of the curved rod is hinged to the connecting rod pin, the other end of the curved rod is hinged to the swinging rod through the swinging rod pin, and the other end of the swinging rod is fixedly connected to the crankshaft.
The large gear is offset relative to the crankshaft, and the large gear is hinged with the curved rod, and the curved rod is hinged with the swinging rod. The swinging rod is fixed together with the crankshaft, and the crankshaft drives the connecting rod to push the slider up and down. When the large gear rotates clockwise, the swinging rod is pushed to rotate by the curved rod. Due to the deviation between the large gear and the crankshaft, the distance between the center of the connecting rod pin and the center of the crankshaft changes within a certain range during rotation, resulting in a change in the angle between the swinging rod and the curved rod. As a result, when the gear rotates at a constant speed, the crankshaft rotates at a variable speed, reflecting that the speed of the slider is accelerated and slowed down compared to ordinary precision punching machines. As long as the parameters are designed reasonably, the slider can decelerate near the bottom dead center and accelerate on the return journey. This ensures reliable travel times during the operation of the punching machine.