| 摘要 |
The cylinder head includes, for each cylinder, two annular valves concentric between them and the cylinder. The inlet valve ensures sealing of gas by a valve seat in the cylinder, and has a return system which tends to maintain the valve on its seat in the open or closed position under the effect of hydraulic pressure which is applied to the exit valve. The exit valve is located at the interior of the inlet valve and resting on it, and ensures the sealing by use of a valve seat which is located on the inlet valve. It has a return mechanism which tends to lift it from the seat, and is opened and closed by a cam, a piston and a volume of oil. The position of the hydraulic piston which corresponds with the closure of the two valves puts the volume of oil in connection with a source of pressure such that the pressure applied on the exit valve is sufficient to assure the sealing on its seat, but insufficient for opening the inlet valve. A part of the course of the hydraulic piston controls the opening and closing of the exit valve, and the other part of its course controls the displacement of the assembly of two valves and hence the opening and closing of the inlet valves. The displacement of the two valves is controlled by a single cam by cylinder.
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