A full-scale clamping force variable internal high pressure forming machine with internal pressure

Abstract

The invention discloses a variable die assembling force inner high-pressure forming machine, and belongs to the field of pipe forming machining equipment. The variable die assembling force inner high-pressure forming machine comprises a second die assembling oil cylinder proportional servo valve (43) and a first die assembling oil cylinder proportional servo valve (15). One oil port of the second die assembling oil cylinder proportional servo valve (43) communicates with a plunger cavity (41) of a plunger cylinder (3901) and a piston cavity (44) of a piston cylinder (3902), and the other oil port of the second die assembling oil cylinder proportional servo valve (43) is closed. One oil port of the first die assembling oil cylinder proportional servo valve (15) communicates with a piston rod cavity (42) of the piston cylinder (3902), and the other oil port of the first die assembling oil cylinder proportional servo valve (15) is sealed. The second die assembling oil cylinder proportional servo valve (43) and the first die assembling oil cylinder proportional servo valve (15) control the oil pressure of the plunger cavity (41), the piston cavity (44) and the piston rod cavity (42) at the same time. The forming machine is applicable to the situation that the maximum die assembling force is larger than or equal to 20,000 KN, high die assembling control precision is achieved in the range from the zero die assembling force to the maximum die assembling force, meanwhile, the pressure control precision is high, and hydraulic impacts do not exist.

Description

technical field [0001] The invention belongs to the field of pipe forming processing equipment, and in particular relates to an internal high-pressure forming machine with variable clamping force in a full range according to internal pressure. Background technique [0002] Tube high pressure forming technology is an advanced variable-section hollow member manufacturing method, which has been widely used in the production of automotive structural parts, and is also used in the forming of large-diameter closed variable-section tubes in the aerospace industry. The main process is as follows: firstly fill the pipe with liquid, and at the same time seal both ends of the pipe through an axial punch, then increase the liquid pressure inside the pipe through an external supercharger, and use the hydraulic pressure to make the pipe plastically deformed to obtain a variable cross-section pipe fittings. [0003] The internal high pressure forming machine is a plastic forming equipment...

AI Technical Summary

Problems solved by technology

The main disadvantage of this internal high pressure forming machine with constant clamping force is: in the initial stage of forming, there is no liquid or the liquid pressure is very small inside the pipe, and the hydraulic reaction force generated by the internal pressure is zero or very small. At this time, the clamping cylinder is the largest The mold clamping force is all applied to the mold, causing large elastic deformation of the mold, shortening the life of the mold, and affecting the dimensional accuracy of the parts at the same time

The servo valve can adjust the pressure of chamber A and chamber B to achieve the required mold clamping force, but because the volume of chamber A is much larger than that of chamber B, it is very easy to cause overpressure in chamber B, which has a great impact on the piston rod chamber and seriously affects the oil cylinder. seal life, or even damage the cylinder

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