METHOD FOR PREVENTING BACK FLOW FROM OCCURRING IN INJECTION MOLDING MACHINE AND BACK FLOW CHECK RING FOR INJECTION MOLDING MACHINE USED FOR PRACTICING IN ITS USE

摘要

PURPOSE: To decrease the amt. of back blow of a molten resin and to prevent the amt. of back flow at every shot from being deviated. ;CONSTITUTION: A front side back flow check ring 4 has slits 4c arranged each other at an interval in the peripheral direction at its apex and one inclined face 4a inclining to the crosssection in the radial direction provided on the back end. On the other hand, a back side back flow check ring 5 has another inclined face 5a provided on the apex and a seal face 5b provided on the back end. The angle of inclination between one inclined face 4a and another inclined face 5a brought into surface contact with each other can be made into an arbitrary angle within a range in which a counterforce for moving reversely the front side back check ring 4 and the back side back flow check ring 5 toward the outside in the radial direction of a cylinder 1 is generated and the mechanical strength can be kept.;COPYRIGHT: (C)1996,JPO