(1) (extruder parts)The existing extrusion power control mode is to use 6-pole or 4-pole constant speed AC asynchronous motor to drive variable piston pump and vane pump. The variable displacement piston pump changes the variable mechanism of the oil pump according to the needs of extrusion speed to realize the speed regulation function; The vane pump provides auxiliary action and requires hydraulic drive. It has the following disadvantages:
① The host will generate reactive work in standby.
② The actual working time of vane pump when providing auxiliary action in each extrusion cycle is only about ten seconds. The oil is returned through overflow in the rest of the time, which will consume a certain amount of electric energy.
③ The service life of the oil pump will be shortened if it works or idles for a long time.
④ When the main engine is in standby and the motor and oil pump are idling, the hydraulic oil will generate heat.