| 摘要 |
Provided are a variable valve device and a control method thereof for actually measuring a variable performance of valve response with changes in temperature environment and accurately correcting valve opening and closing timing of the variable valve based on measurement results. The variable valve device has a hydraulic actuator that implements discharge of operating oil in a pressure chamber of a cylinder by a closing movement of an intake valve, and a hydraulic control valve that controls supply and discharge of the operating oil to and from the hydraulic actuator by opening and closing, and prevents outflow of the operating oil from the pressure chamber during closing, thereby preventing the closing movement of the intake valve. After a signal that closes the hydraulic control valve in a current engine control cycle is output at a prescribed crank angle, the crank angle of a crankshaft, when surge pressure in the pressure chamber has exceeded a prescribed threshold value resulting from closing of the hydraulic control valve, is determined as an operation start crank angle of the hydraulic control valve, and at least either an output crank angle or a waveform of the signal that closes the hydraulic control valve is corrected based on the operation start crank angle, and moreover, the corrected signal is output to the hydraulic control valve in a next control cycle.
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