Patent ID: 8245398
Filing Date: 2012-08-21
Classification: B29C,B29D,B29L,F16J,Y10T

Abstract:
1. A seal-ring shape forming method by which a synthetic-resin seal ring is formed in a shape such that abutment joint ends of the seal ring face each other with a predetermined gap, the seal ring being molded such that the abutment joint ends are separated from each other, the abutment joint ends being provided at one point on a circumference of the seal ring and able to be joined to each other, the seal-ring shape forming method comprising: a first process of fitting the seal ring into an annular gap while the abutment joint ends face each other with a substantially predetermined gap, the annular gap being formed between an inner circumferential surface of a hole portion provided in an outer circumferential jig and an outer circumferential surface of an inner circumferential jig disposed in the hole portion; a second process of passing the seal ring through a heating region in the annular gap, the outer circumferential jig and the inner circumferential jig being maintained at a constant temperature higher than a glass transition temperature of a resin material for the seal ring in the heating region; and a third process of passing the seal ring passed through the heating region through a cooling region in the annular gap, the outer circumferential jig and the inner circumferential jig being maintained at a constant temperature lower than the glass transition temperature of the resin material for the seal ring in the cooling region.