In recent years, the pearl river delta region has some of the small and medium-sized enterprise molding production of injection molding machine hydraulic system to make use of frequency converter technology and energy saving transformation, a greatly reduces the power consumption in molding production, thereby significantly reduces the production cost of injection molding products, bring considerable economic benefits.

　　Work cycle of injection molding machine injection molding process is a periodic process, starting from the clamping action of hydraulic system in the process of the periodical must complete a series of action: mold, open mold, injection of a whole movement, pressure and ejection products, etc.

　　Work and injection molding machine in one work cycle has close relationship with the hydraulic system of main working parameters of injection pressure, injection rate, clamping force, the holding pressure, etc. Injection pressure is overcoming the molten material flows through the nozzle, flow and mold cavity flow resistance, ensure molding stability, an important factor to ensure precision and qualified rate of injection molding products. When the screw diameter must be the size of the injection pressure is determined by the hydraulic system. Injection rate is characterization of the melt and mold cavity parameters of speed, it directly affect the quality and productivity of products, its size by injecting oil cylinder work flow control. Clamping force is clamping mechanism for injection molding mold can exert maximum clamping force, it with the injection quantity become nominal parameters of injection molding machine specification, for hydraulic - toggle clamping device, the size of the clamping force is determined by the hydraulic system and toggle lever mechanism; For hydraulic clamping device, clamping force size is determined by the injection molding machine hydraulic system.

　　The holding pressure is one of the important molding process parameters, the choice of the holding pressure and holding time directly affects the quality of the injection molding products, the holding pressure and injection pressure as determined by the hydraulic system.

　　Injection molding machine hydraulic system of hydraulic system is an important component of the injection molding machine, it must satisfy the whole work needed throughout all phases of the different requirements of pressure and velocity. Hydraulic system should have good stability and repeatability and high sensitivity, low noise and energy saving, etc. Hydraulic system is mainly composed of hydraulic pressure of chestnut, valves, cylinders and loop.

　　In injection molding production, according to the needs of the injection molding process, the hydraulic system for plastic injection machine work flow and work pressure should be constantly changing, so the injection molding machine hydraulic system consumed power should also be changed with the work flow and work pressure, changing.