CO-INJECTION TYPE INJECTION MOLDING EQUIPMENT WITH ROTATING AXIAL STARTING MECHANISM

摘要

PURPOSE: To reduce required driving force while enhancing control accuracy by respectively reciprocating a valve pin member and a valve sleeve member in an axial direction. CONSTITUTION: An elongated valve pin member 64 is inserted into an elongated valve sleeve member 56 so as to become concentric to a gate 20 and both valve members 56, 64 are reciprocated in a rotary direction and an axial direction by the action of separation type start mechanisms to control the flow of the fluid passing through the gate 20. The start mechanisms have piston driving type rack members 96 for performing rotary motion and this rotary motion is coverted to the axial motion between the retreat opening position and advance closing position of the valve members 56, 64 corresponding thereto. In one form, the spiral screws of the valve members 56, 64 are engaged with fixed teeth extending in the inside direction from circumferential nozzles to covert the rotary motion of the valve members 56, 64 to the axial motion corresponding thereto.