1. Internal high pressure process:

·The high-pressure forming process in pipe fittings is to introduce high-pressure water into the steel pipe to form the required shape of the pipe wall.

·Internal high pressure forming is widely used in automobile frame, engine bracket, exhaust pipe, camshaft, axle, chassis and other parts, and it is one of the effective means of automobile lightweight.

2. Internal high-voltage complete equipment composition：

l Main engine of internal high pressure forming hydraulic press:

·Used for die closing and pressure control. During die closing, the pressure can be controlled in linkage according to the pressure in the pipe, which increases the flexibility of the process. Generally, four-column hydraulic press or frame hydraulic press is used. The workbench and slider meet the requirements of the process for stress concentration and have good rigidity.

l Internal high pressure system:

·Booster cylinder, servo hydraulic system. The low-pressure side of the booster cylinder is driven by hydraulic oil and controlled by proportional servo valve, and the high-pressure side is emulsion (95% water) with a pressure of 250-400MPa.

·1-2 groups of booster cylinders are used, and 2 sets of booster cylinders are used when one mold has two holes.

·The high-pressure cavity adopts double-layer cylinder structure, which reduces the stress of materials, increases reliability and prolongs service life.

l Water (95% water +5% emulsion) system: including quick liquid filling, pressure cylinder liquid replenishment, pre-filling liquid, emulsion filtration system, etc.

l Side cylinder system: side cylinder servo control system (2 sets or 4 sets), 4 sets of systems can meet the requirements of 1 mold and 2 points, and the position of side cylinder is linked with the pressure of booster cylinder to realize the function of feeding.

l Punching and sealing system: the pipe wall punching system realizes quick punching, and the sealing system is used for sealing the side punch.

l Mold: mold base, mold cavity, servo side cylinder (2 sets or 4 sets), punching and ejecting cylinder and sealing cylinder.

l Electrical system: high current, weak current, multi-axis linkage (4-axis or 7-axis) servo control, control interface and control software.