Process for two-stage injection molding of air-conditioning blow-out port device

A process for two-stage injection molding of an air-conditioning blow-out port device comprising:

• a housing of synthetic resin, which includes pairs of shaft bores provided in a coaxial arrangement in opposed wall portions of a peripheral wall to extend through the opposed wall portions, and
• a plurality of blades of synthetic resin which each include a pair of support shafts projectingly provided at opposite ends of a blade body disposed within the housing and rotatably fitted in the shaft bores of the housing, the process comprising the steps of:
• closing a pair of housing-forming opposed opening-closing dies to clamp, between both the opening-closing dies, a plurality of first opposed slide dies each including a plurality of shaft bore-forming cores and a plurality of protrusions juxtaposed with the cores, thereby defining a housing-forming cavity so as to include the shaft bore-forming cores and the protrusions;
• primarily injecting a synthetic resin into the cavity to form the housing including the shaft bores and a plurality of recesses in the opposed wall portions, the recesses being formed by the corresponding protrusions of the first slide dies and opened into outer surfaces of the opposed wall portions;
• retreating the first opposed slide dies such that the shaft bore-forming cores and the protrusions are removed from the corresponding shaft bores and recesses formed in the housing, and opening the pair of housing-forming opposed opening-closing dies leaving the housing attached to one of the opening-closing dies;
• closing the one of the opening-closing dies for forming a front edge of each blade body located on a side of a front surface of the housing, while closing another opening-closing die for forming a rear edge of each blade body, the another opening-closing die including a plurality of second opposed slide dies each having a plurality of protrusions corresponding to the recesses formed in the housing, thereby clamping the second slide dies between both of these opening-closing dies, with the housing being clamped between these opening-closing dies and the second slide dies and with the protrusions of the second slide dies being fitted into the recesses of the housing, respectively, while defining blade body-forming cavities between these opening-closing dies;
• using the shaft bores in the housing as support shaft-forming cavities and secondarily injecting a synthetic resin into the blade body-forming cavities and the support shaft-forming cavities to form the blade bodies and the rotatably fitted support shafts of the blow-out port device;
• opening both the opening-closing dies, with the blow-out port device being left on the another opening-closing die by the fitting of the protrusions of the second slide dies into the recesses in the housing;
• and
• separating the protrusions of the second slide dies out of the corresponding recesses, and then bringing a plurality of ejector pins provided on the another opening-closing die into abutment against the rear edges of the blade bodies respectively to push off the blow-out port device from the other opening/closing die.