| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress deterioration in accuracy and strength of a shaft portion in a motor with a speed reduction mechanism in which a resin-made gear case and the shaft portion for rotatably supporting a worm wheel are integrally molded. <P>SOLUTION: A communicating hole 45 for communicating both sides with a wall portion 44 sandwiched is provided on the wall portion 44 for segmenting through-holes 43a, 43b each penetrating a shaft portion 40 of the gear case 31 in a shaft direction. With this configuration, in injection molding of the gear case 31, an air can be flowed inside a small-diameter column portion 41b via the communicating hole 45 in pulling out a second bar-like molding die 91 forming the inside of the small-diameter column portion 41b. Since a space between the small-diameter column portion 41b and the second bar-like molding die 91 does not become a vacuum state, a sink or a void can be prevented. Since the deterioration in accuracy of the shaft portion 40 or in strength can be prevented, the yield of the gear case 31 can be improved. <P>COPYRIGHT: (C)2009,JPO&INPIT |
