| 摘要 |
PURPOSE:To control the opening of a throttle valve so as to effect automatic restriction of the maximum driving speed by actuating a pressure restracting means which is provided in a passage communicating the intake duct between an air purifier and a supercharger, and the lower course from a secondary throttle valve with each other. CONSTITUTION:At high speed run of an engine, the primary throttle valve 5 is opened widely by an accelerator and the rate of supercharge of air supplied from a supercharger 2 is simultaneously increased, on account of which the pressure around the opened secondary throttle valve 14 is reduced below the atmospheric pressure. Said pressure is therefore delivered to a pressure receiving chamber 9 via a pressure duct 7 to make a push rod 12 go forward so as to increase the opening of a secondary throttle valve 14. On the other hand, a change-over valve 17 is designed so as to be opened when the pressure in the pressure duct 7 is increased over the atmospheric pressure so that the pressure in both the pressure duct 7 and the pressure receiving chamber 9 is released into a duct 15 via a communication passage. Therefore, the pressure receiving chamber 9 may be controlled slightly lower than the atmospheric pressure and full speed control may be effected by setting both a pressure responsive device 8 and the change- over valve 7 so that this pressure corresponds to the prescribed full speed. |
