Built-in reverse-pulling type holder mechanism of plastic injection machine and movable die plate thereof

The utility model provides a built-in reverse redrawing type backform mechanism of injection machine, comprising a push-out oil cylinder and a movable moulding board; the push-out oil cylinder is directly connected with the movable moulding board; the movable moulding board applied in the above built-in reverse redrawing type backform mechanism can directly connect with the push-out oil cylinder without the push rod. The utility model has a reasonable structure, the intensity of the movable moulding board is strengthened, and the stress on the movable moulding board is even, so that the movable moulding board is seldom deformed; during the procedure of injection, no material over flows out from the mold cavity, therefore, the mould has long life span; the utility model also has the advantages of long push-out stroke, thus, the longer(higher) products is facilitated to be processed, so that the utility model has a great applicability; the utility model has a simple structure, easy manufacture and assemble; and the utility model is suitable in the variable injection moulding machines and has a relative wider applicability range and greater market prospect.