| 摘要 |
PURPOSE:To attain a spark advance in case a negative (neg.) pressure at the same level is applied both to the advancing and retarding ports, by forming No.1 neg. pressure chamber with case seal bellows and part of retarding diaphragm, and No.2 neg. pressure chamber with the case and a diaphragm for spark advance. CONSTITUTION:When a neg. pressure is introduced to a spark advance port 8, the atmospheric pressure will draw up a spark advance diaphragm 10, and now a rod 7 rises to provide a spark advance corresponding to a bevel plate 71 at the tip of rod proceeeding and making contact with a max. spark advance stopper 144. When a neg. pressure is introduced to a spark retardation port 9, on the other hand, the atmospheric pressure in the upper part will depress a diaphragm for spark retardation 11, and the rod 7 now sinks to provide a spark retardation corresponding to a max. angle retardation stopper 72 proceeding and making contact with a spring receptacle plate 16. If a neg. pressure at the same level is introduced both to the spark advancing and retarding ports 8, 9, an upward pull is provided because the area of diaphragm 10 receiving the neg. pressure is larger than that of the diaphragm 11, and now the rod 7 will rise to provide spark advance. |
