SEALING STRUCTURE FOR MOLDING MACHINE

摘要

PURPOSE:To develop prominent sealing property and prevent the leakage of material by a method wherein a clearance between a cylinder or a chamber for supplying material to the molding machine and a plunger is sealed by a spring washer. CONSTITUTION:The spring washer 5 is made of a spring material such as phosphor bronze or the like so as to be capable of sliding smoothly in the injection cylinder 1 of steel, provided with a diameter same as or slightly larger than the diameter of the injection plunger 4, is capable of being inserted into and fixed to the injection cylinder 1 so that whose inside is faced to the high-pressure side of the cylinder and whose rear side is faced to the direction of the root of the injection plunger 4 and is protruded slightly from the outer periphery of the injection plunger 4 at the outer peripheral rim thereof. The spring washer 5 is attached so as to be capable of enlarging the outer diameter thereof by deforming elastically under cambering rearwardly in case the spring washer 5 receives a pressure from the forward side of the injection plunger 5 while the outer peripheral rim section thereof contacts strongly with the internal surface of the injection cylinder 1 as the internal pressure of the same cylinder is increased and whereby a good seal may be produced between the injection plunger 4 and the injection cylinder 1.