| 摘要 |
<p>PURPOSE:To optimize boosted pressure, by feeding output from a knock sensor upon generation of knocking to upper and lower limit judging devices of advancing value, and operating a solenoid valve through a flip flop according to outputs from the upper and lower limit judging devices. CONSTITUTION:In case of fuel of normal octane value, when an engine 1 starts supercharging operation, a pressure switch 21 is operated by discharge pressure of a compressor 3 to close an opening/closing mechanism 19. At the time, knocking is generated, and a retarding signal is generated from an ignition timing controller 16. When the signal reaches a lower limit, output is supplied from a lower limit judging device 33 to a flip flop FF24 to turn off a solenoid valve 13 and open a bypass valve 7 by an actuator 8. As a result, boosted pressure is reduced to prevent generation of knocking. In case of fuel of high octane value, even when the pressure switch 21 is operated under engine supercharged condition, an advancing signal is further generated to provide output H from an upper limit judging device 22 and invert output from the flip flop FF24, thereby increasing the boosted pressure.</p> |
