| 摘要 |
PROBLEM TO BE SOLVED: To attain a positive integral formation of a hard main body constituting a lid member and a soft circumferential edge part formed at a circumferential edge of the main body while reducing its cost, perform an easy prevention of occurrence of burrs and improve its sealing-closed characteristic. SOLUTION: A communication between one cavity for a hard main body and the other cavity for a soft circumferential edge is shut off by inserting a shutter device 4 provided with a separating protrusion 43 having a step part 44 corresponding to a step part 30 of a lid member at an interface portion between the cavity for the soft main body and the cavity for the soft circumferential edge, synthetic resin is primarily injected into the cavity for the hard main body, thereafter the separating protrusion 43 is retracted in such a way that its step part 44 is projected out of the hard main body 11, thereby the step part 30 of the lid is exposed in the cavity for the soft circumferential edge, synthetic resin is secondary injected into the cavity for the soft circumferential edge so as to cause the soft circumferential edge and the protrusion rib to be integrally formed. |
