To provide a variable valve gear which is provided with a hydraulic piston which pushes a rocker arm so that an engine valve is brought into a valve-opening state, and recovers hydraulic pressure generated by the ascent and descent of the hydraulic piston as engine drive energy.

A block 7 is arranged above the rocker arm 6 which opens the engine valve (intake valve 2) against a valve spring 5 by the rotation of a camshaft 3. The block is provided with the hydraulic piston 13 and an oil passage 16. The hydraulic piston presses the rocker arm 6 by the hydraulic pressure of a hydraulic pressure chamber 12, and retains the intake valve 2 in a valve-opening state. The oil passage 16 guides a hydraulic fluid to the hydraulic pressure chamber 12 through a check valve 14, and discharges the hydraulic fluid from the hydraulic pressure chamber 12 through a solenoid valve 15. The pressure of the hydraulic pressure chamber 12 is retained by the solenoid valve 15, and released to control the valve-closing timing of the intake valve 2. A hydraulic pressure turbine 20 is provided to the camshaft 3, and the hydraulic pressure turbine 20 and the discharge port 19 of the oil passage of the block 7 are connected to each other by an oil-guiding passage 21. Then an oil-discharging passage 22 is connected to the hydraulic pressure turbine 20.

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