The invention discloses an internal high-pressure forming
machine with variable mold clamping force. The internal high-pressure forming
machine comprises a
machine body, a hydraulic
system and a liquid-filled
system, wherein a long-
stroke oil cylinder is arranged on the upper part of the machine body, and an upper sliding block is connected to the front end of a
piston rod of the long-
stroke oil cylinder; an upper die is installed on the lower surface of the upper sliding block; a short-
stroke oil cylinder is arranged at the bottom of the machine body, the short-stroke oil cylinder comprises a
plunger oil cylinder and four auxiliary
piston oil cylinders, a lower sliding block is installed on the upper end of the short-stroke oil cylinder, and a lower die is installed on the upper surface of the lower sliding block; horizontal positioning oil cylinders are respectively installed on the left and right side walls of the upper part of the machine body, and positioning blocks are installed on the front ends of
piston rods of the horizontal positioning oil cylinders; axial feeding oil cylinders are respectively installed on the left and right side walls of the lower part of the machine body, and sealing punches are installed on the front ends of piston rods of the axial feeding oil cylinders; a pressure cylinder is arranged on the liquid-filled
system; the hydraulic system is used for supplying working media for driving all of the oil cylinders to operate. The invention further discloses an internal high-pressure forming
processing method. According to the internal high-pressure forming machine, the mold clamping force can change according to a given load curve as the internal
high pressure of a tube changes, so that the quality of a formed part and the production efficiency are increased.