METHOD OF MEASUREMENT AND INJECTION FOR INJECTION MOLDING OF METALLIC MATERIAL

摘要

PROBLEM TO BE SOLVED: To use seal rings on an injection plunger which make it possible to measure volume of molten metal by suction caused by negative pressure while preventing measured material from reflex by tension of seal rings caused by pressure load for injection at the time of injection of the material. SOLUTION: A nozzle mouth and a measuring chamber 15 connected each other are attached to a front end of a melting chamber 11. An injection plunger 19 is inserted into the measuring chamber 15 keeping some sliding clearance 20. Ring grooves 22 are made along peripheral surface of front portion of the plunger 19. Seal rings 21 made of heat-resistant piston rings are fitted to ring grooves 22 keeping some clearance. Molten metal 26 is sucked through the sliding clearance 20 into the measuring chamber 15 and measured, when the nozzle mouth is clogged by cold plug 27 and the plunger 19 is forced to retract causing negative pressure in the chamber. Injection is made when the sliding clearance 20 is shut by tension of the seal rings 21 caused by injection pressure load.