| 摘要 |
<p>PURPOSE:To make highly accurate, stable control over supercharging pressure performable as well as to improve a rate of fuel consumption, by performing a closed-loop control when the supercharging pressure is in a stationary state and, when it is in a transient state, performing open-loop control, respectively, when the supercharging pressure of a supercharger is controlled. CONSTITUTION:In a suction passage 8, there are provide with a compressor part 7 of a turbosupercharger 2, an intercooler 9 and a throttle valve 11 in order. At the upstream side of a turbine part 14 of the supercharger 2, there is provided with a variable nozzle 3 consisting of a lot of vanes annularly installed in line, and each opening of the variable nozzle 3 is adjusted by an adjusting mechanism 4 whereby a flow velocity of exhaust gas is made controllable. This adjusting mechanism 4 is controlled by an actuator 20, and pressure at the downstream side of the compressor part 7 is made so as to be led into the positive pressure chamber 38 via a control valve 18a. And, this control valve 18a is made so as to be controlled by closed-loop control when the supercharging pressure is in a stationary state but it is in a transident state, by open loop control, respectively, by a control unit 17.</p> |
