| 摘要 |
PURPOSE:To prevent overflow and percolation of fuel in a float chamber, by providing a fuel pump with a means for controlling the discharge pressure of the fuel pump when the temperature of intake air is higher than a certain level. CONSTITUTION:In ordinary operation of an engine when the temperature of intake air is lower than a prescribed level, an air chamber 1b of a fuel pump 1' is communicated with a connector 9 of a vaccum switch valve 10 via a connector 8, and opened to the atmosphere via a port 11a, valve spring part 10c, port 10a and dust filter 10b. Therefore, the fuel pump 1' supplies fuel to the float chamber 6 of a carburetor 5 under a normal fuel discharging pressure. On the other hand, when the temperature of intake air becomes higher than said prescribed level, a sensor switch 15 is turned ON by a sensor for detcting the temperature of intake air and current is supplied to the valve 10, so that its valve body 11 is moved downward. Resultantly, the negative pressure at the vacuum outlet port 14' is transmitted via the valve 10 into the air chamber 1b, so that the discharge pressure of the pump 1' is lowered. |
