| 摘要 |
There is a supercharge pressure control apparatus of a supercharged engine. A bypass is provided to bypass a supercharger turbine arranged between the intake and exhaust passages. A waste gate valve is attached at one end of the bypass and is coupled to an actuator having a pressure chamber communicated with a connecting passage which is branched at a branch point into the first and second passages. A first port is formed in the intake passage downstream near a suction inlet of a compressor and a second port is formed in the intake passage downstream of the first port. In the stationary operating state, the connecting passage is communicated with the second passage by the change-over valve, so that a high pressure from the second port acts on the pressure chamber and the supercharge pressure is maintained at a set level. In the acceleration operating state, the connecting passage is communicated with the first passage for a predetermined time, so that a low pressure from the first port acts on the pressure chamber. When the pressure at the first port reaches the set level, the pressure at the second port exceeds the set level, so that the supercharge pressure over the set level is supplied into the engine. After a preset time, the connecting passage is communicated with the second passage and the pressure is held at the set level.
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