| 摘要 |
PROBLEM TO BE SOLVED: To provide a resin toothed wheel capable of enhancing strength and dimensional precision. SOLUTION: The resin toothed wheel 16 includes a rim 22 provided at the peripheral part of a circular plate 21, teeth 23 provided at the periphery of the rim, a boss 24 provided at the center part of the plate 21 and a circular rib 25 provided between the boss 24 and the rim 22. The resin toothed wheel 16 is injection-molded by injecting a molten material into a cavity from a plurality of gates rectangularly to the plane of the plate 21 at positions having an approximately equal angel distance on the circular rib 25. The resin toothed wheel 16 has a plurality of inner thin-walled parts 27 on the plate 21 between the circular rib 25 and the boss 24 which are symmetrical with respect to a line in the radius direction passing through gate corresponding spots 26. The resin toothed wheel 16 has a plurality of outer thin-walled parts 29 on the plate 21 between the circular rib 25 and the rim 22 which are symmetrical with respect to a line in the radius direction passing through the gate corresponding spots 26. COPYRIGHT: (C)2007,JPO&INPIT |
