Injection system with inner-set check valve for die casting machine was development to solve the problems of the long establishment-time in three-stage injection system in traditional die casting machine due to use floating piston to pressurization.Inner-set check valve with spring reset which was installed in pressurization piston rod could rapidly switch off cone face with the help of spring to shorten established-pressure time by pressurization.Injected piston buffer mechanism was designed between the right end of injected piston and inner-set check valve

so the size of oil entrance during slow injection process is increased gradually with the move of injected piston

realizing the proportional acceleration of slow injection velocity.