| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for molding a product with good productivity and high accuracy and a molded article with low warpage and coaxial property and a mold for it when a hollow shaft and a diameter-expanded part such as a gear is to be integrally molded. SOLUTION: In a mold for blow injection molding wherein a shaft part 1 and a gear part 2 can be integrally molded, by providing a gas penetration controlling pin at the center of the shaft of the gear part 2, penetration of the gas is stopped just before the gear part 2 by means of the controlling pin to form a hollow part 1a in the shaft part 1 caused by feeding of the gas and on the other hand, a hollow part 2a formed after the pin is pulled out is formed in the gear part 2.
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