| 摘要 |
PURPOSE:To prevent the sharp elevation and lowering of a valve lift and generation of shock noise by restricting the control timing for the stop and start of valve operation at the time when the lift amount of the tappet is little. CONSTITUTION:A hydraulic chamber 26 is formed between a tappet 22 driven by a cam 21 and the stem end 29 of a valve 28, and is connected to an accumulator 37 through a circuit 36. When an opening and closing valve 39 is opened by being controlled by an opening and closing valve control unit 44, the hydraulic chamber 26 communicates to the accumulator 37, and the operation of the valve is suspended. Said opening and closing valve control unit 44 transmits the hydraulic pressure applied from an oil pressure source to the opening and closing valve 39 through a circuit 71 and a distributor. Said opening and closing valve control unit 44 is equipped with a means for detecting that the lift amount of the tappet 22 is less than a prescribed amount, and executes the switching between the start and stop of the operation of the valve, at the time when the lift amount is little. |
