| 摘要 |
<p>PURPOSE:To prevent excessive rise of the supercharging pressure, by providing a valve opening pressure control means which lowers the valve opening pressure of a diaphragm type control valve for a certain while after acceleration of an engine, and thereby compensating delay of response at the time of rapid acceleration. CONSTITUTION:In case that the speed of fluctuation of the supercharging pressure is slow, a delay means 15 does not function substantially and the supercharging pressure introduced into a first chamber 11b is equal to that introduced into a second chamber 11c. The valve opening pressure P0 of a diaphragm type control valve 9 is determined by the formula, P0=F/DELTAS, where F is the setting load of a coil spring 11f and DELTAS is the area difference of the first chamber 11b and the second chamber 11c. When an engine 1 is accelerated rapidly by depressing the accelerator pedal deeply, a turbine 5 is driven at a high speed and the supercharging pressure is raised rapidly. The raised supercharging pressure is introduced immediately into the second chamber 11c but it is not introduced immediately into the first chamber 11b since a delay means 15 is connected operatively to the first chamber 11b. Thus, the diaphragm type control valve 9 is opened and the valve opening pressure is not raised to a level higher than P0 that is the valve opening pressure at the time when the engine is operated steadily.</p> |
