| 摘要 |
PURPOSE:To correctly advance ignition timing, by providing an extensible seal member between an atmospheric air chamber and spark advance operating lever simultaneously providing a vent hole in a side wall of the atmospheric air chamber and preventing a change of air pressure in a distributor main unit from propagating to the atmospheric air chamber. CONSTITUTION:A bellows-like seal member 13 is interposed between the side wall of an atmospheric air chamber A and spark advance operating lever 11, and one bead part of the seal member 13 is fitted to an annular groove 14 in the periphery of an intermediate part of the operating lever 11, simultaneously the periphery of the operating lever 11 is surrounded by the barrel part of said member, further the other bead part is held between an annular groove 15 in the periphery of a connecting tube 5 and internal surface of a cylindrical part 7. Further a vent hole 3, opening the inside of the atmospheric air chamber A to the atmosphere, is provided in the side wall of the atmospheric air chamber A. In this way, even if air pressure is changed in a distributor main unit 6, its propagation to the atmospheric air chamber A is prevented by the seal member 13 to hold the inside of the atmospheric air chamber A always to the atmospheric pressure, then pressure responsive operation of a diaphragm 2 can be accurately performed to control the ignition timing to always correct spark advance. |
