| 摘要 |
<p>PURPOSE:To improve the fuel consumption without reducing the startability of an engine by mounting a compression ratio variation device which increases the compression ratio when the engine starting time is detected and reduces the compression ratio when the time after the engine start is detected. CONSTITUTION:A valve timing variation device 17 which controls the compression ratio by regulating the timing at which an intake valve 7 is to be opened and closed is mounted on an intake valve cam shaft 15 of cam shafts 15 and 16 which drive the intake valve 7 and an exhaust valve 8 to be opened or closed, respectively, and said device 17 is controlled by an electronic control unit 30. According to the receival of the output signal from a crank angle sensor 20 or a starter switch 21, the electronic control unit 30 determines whether the engine is being started or operated after the starting. When the starting time of the engine is determined, the variation device 17 is controlled to increase the compression ratio, that is, to advance the valve closing timing for the intake valve 7 and when the time following the starting of the engine is determined, said device 17 is controlled to decrease the compression ratio, that is, to delay the valve closing timing for the intake valve 7.</p> |
