The utility model relates to a primary-secondary type injection oil cylinder for an
extrusion casting machine. The primary-secondary type injection oil cylinder comprises an injection oil cylinder and a quick oil cylinder, the injection oil cylinder and the rapid oil cylinder are located outside the rapid oil cylinder and have the same telescopic direction. The injection oil cylinder comprises an injection oil cylinder
barrel, an injection oil cylinder
piston, an injection oil cylinder
piston rod, an injection oil cylinder
flange, an injection oil cylinder rear cylinder cover and an injection oil cylinder front cylinder cover; the rapid oil cylinder comprises a rapid oil cylinder
plunger and a rapid oil cylinder cover. The front end of the rapid oil cylinder
plunger is inserted into a central
blind hole of the injection oil cylinder
piston rod, and the rear end of the rapid oil cylinder
plunger is fixedly connected with a rear cylinder cover of the injection oil cylinder through a
flange. And the injection oil cylinder piston can move back and forth in an inner hole of the injection oil cylinder
barrel. According to the
pressure injection oil cylinder, the speed of a traditional
pressure injection oil cylinder can be achieved without an energy accumulator, and meanwhile
pressure injection force is kept stable during pressurizing pressure injection. The
squeeze casting machine is high in structural strength,
energy storage time is not needed, meanwhile, the displacement of the
oil pump is small, and
energy consumption is low.