INJECTION MOLD

PURPOSE: To provide an injection mold, with which working efficiency can be improved by a method wherein neither supporting part nor runner forming part nor gate forming part is not formed and consequently the process for recovering the supporting part and the like is eliminated. CONSTITUTION: A diaphragm 63 is elastically deformed by the pressure of synthetic rubber filling a gate 57 so as to drive an opening and closing member 62 upwards, resulting in separating a tip part 64 from the edge of a communicating hole so as to pass the synthetic rubber in the gate 57 through the communicating hole in order to inject the synthetic rubber in a cavity 92. When the pouring of the synthetic rubber from a nozzle 38 is brought to an end, the pressure of the synthetic rubber lowers so as to reach a value smaller than the certain value. As a result, the pressure applied to the diaphragm 63 lowers, resulting in lowering the opening and closing member 62 by means of the elastic force of a coned disc spring 65 so as to urge the tip part 64 against the edge of the communicating hole in order to realize the closed state in which the communicating hole is closed. Thus, the synthetic rubber in the gate 57 is separated from that in a pouring hole.