| 摘要 |
PURPOSE:To prevent Venturi negative pressure from being reduced at the low- speed and high-load time and maintain density of mixture to the specified value by having a throttle valve opening restricting device connected to and coincide with the revolutional speed setter of an engine so that said device will be placed in the opening restricted condition at a low-speed revolution time. CONSTITUTION:In an engine E whose revolutional speed is maintained to the revolutional speed set by a speed setter 4 by controlling opened degree of a throttle valve 2 by means of a governor 1, a valve opening restricting device 5 is connected to and coincides with the revolutional speed setter 4 or a sensor 6. When the engine is revolved at a low speed, the opening restricting device 5 is set in a restriction operating condition A, that is, said device 5 restricts the throttle valve 2 to keep the open degree thereof over the specified middle value. When the engine is revolved at a high speed, said device 5 is set in a restriction releasing condition, that is, the device 5 permits the throttle valve 2 to be opened fully. A Venturi negative pressure at the low-speed running time of the engine is therefore ensured, whereby preventing reduction in torque and sufficiently ensuring the quantity of intake air at high speed running time of the engine. The engine may then maintain a high power. |
