Venting device for die

Abstract

Abstract PURPOSE:To obtain products having good quality and high strength without cavities by opening a venting valve for dies open during injection to discharge gases, and closing the valve in a prescribed position in the mid-way of advancing of an injection cylinder to prevent the oozing of the injected melt to the outside. CONSTITUTION:When a starting switch for injection is turned on while a stationary die 2 and a movable die 3 are held closed, a plunger 6 advances to charge molten metal 37 into cavities 4. As the plunger 6 advances, a striker 7 integral with the plunger advances as well and when the striker disengages from a limit switch 32, a switch 32 is turned on, by which a solenoid 24 is energized and a valve 14 is retreated by the repulsive force of a compression spring to close its opening, thus preventing the ejection of the metal 37 through an air releasing port 23 thoroughly. Since the gases in the cavities 4 are throughly discharged before the valve 14 is closed, such defects as formation of cavities by the gases contained in products are obviated.

Inventors

• 👤 Takahiko Takeshima
• 👤 竹嶋　孝彦

Bibliographic Details