| 摘要 |
PURPOSE:To prevent the abnormal operation of a check valve and efficiently introduce and store the intake negative pressure in a negative pressure chamber by installing a damper chamber for attenuating the pressure pulsation in a negative pressure passage, on one side of the negative pressure passage between an intake manifold and the check valve. CONSTITUTION:On one side of the connecting pipe 12 of a check valve V installed in a negative pressure conduit 4, a cylinder part 15 whose inside is formed to a damper chamber 14 is formed, and is allowed to communicate to the connecting pipe 12 and a negative pressure passage 5 through a through hole 16. A diaphragm 17 is installed in close to the damper chamber 14. The positive pressure wave and negative pressure wave reach alternately into the damper chamber 14 in an intake manifold, accompanied with the opening and closing of the intake valve of an engine. When the positive pressure wave reaches, the diaphragm 17 is pressed to an atmosphere chamber 19 side, and the capacity of the damper chamber 14 is increased, while if the negative pressure wave reaches, the capacity is reduced. Accordingly, pulsation is attenuated, and since a relatively stable negative pressure acts in the valve box 6 of the check valve V, a valve body 10 opening/closing operates precisely. |
