PRESSURE RESPONSIVE MECHANISM IN INTERNAL COMBUSTION ENGINE

PURPOSE:To increase an amount of initial operation and obtain stable hysteresis in the above described device utilizing intake negative pressure, by changing pressure receiving area before and after a start of operation. CONSTITUTION:If an engine is started, intake pipe pressure (intake negaitve pressure) is generated, and this negative pressure is guided to a control chamber 5 in this mechanism through a nipple 2A. The intake negative pressure introduced into the chamber 5 is guided also to a regulating chamber 4 through a small hole 3A in a diaphragm 3. At this time, if capacity of the chamber 4 is formed to fully small size, pressure in the chamber 4 can be equalized to pressure in the control chamber 5. The engine performs complete operation of explosion to reach prescribed intake negative pressure, then the diaphragm 3 is moved rightward against a spring 7, and a retainer plate 8A is unsealed from a seat 9 to change the pressure in the regulating chamber 4 to the atomospheric pressure. In this way, the diaphragm 3 can be operated with stable hysteresis.