Apparatus for controlling pressurized air supply to engines

Abstract

An apparatus for controlling pressurized air supply to an engine has an intake passage connected to the engine at the downstream end thereof. A throttle valve is disposed at a downstream side of the intake passage. A supercharger control valve is disposed at an upstream side of the throttle valve in the intake passage. A supercharger passage containing a supercharger is connected to the intake passage at both upstream and downstream sides of the supercharger control valve. An actuator has an actuating body for dividing the actuator into a first and second pressure chambers. The actuating body is operatively connected to the supercharger control valve to close and open it according to the movement of the actuating body. A compression coil spring is provided in the first pressure chamber for normally pressing the actuating body to open the supercharger control valve. A change-over valve comprises a first pressure-receiving chamber communicating with the first pressure chamber and a second pressure-receiving chamber communicating with the second pressure chamber and the portion of the intake passage between the throttle valve and the supercharger control valve, and a valve body for selectively effecting the communication between the first and second pressure-receiving chambers and between the second pressure-receiving chamber and the portion of the intake passage between the throttle valve and the supercharger valve. A pressure introducing passage communicates with the first pressure chamber at its one end and to the downstream of the throttle valve in the intake passage at its other end.