Isuzu Ceramics Research Institute Co. Ltd.

Kenro Nakashima

A rocker arm for rocking on a rocker arm shaft is constructed to include two arms: a first rocker arm rocked positively by the rotating motion of a cam; and a second rocker arm for actuating the opening/closing actions of an intake/exhaust valve. At a running time of an engine at a high speed/under a high load, an electromagnet of an electromagnetic drive device is excited to move a movable pin forward thereby connect the first and second rocker arms to each other. At a running time of the engine at a low speed/under a low load, on the other hand, the electromagnet of the electromagnetic drive device for a selected cylinder is unexcited so that the movable pin is returned to an initial position by the force of a return spring to disconnect the first and second rocker arms.

Valve resting mechanism for cylinder control type engine

In the combustion chamber structure of the gas engine the combustion chamber members are formed with the sub-communication holes allowing communication between the main combustion chambers and the pre-combustion chambers and also with throat holes in which throat hole valves are installed. This structure avoids excessively high compressed air pressure in the main combustion chambers during the compression stroke and reduces the compression work to improve performance. The sub-communication holes open at the wall surfaces situated in the main combustion chambers and also at the upper wall surfaces of the pre-combustion chambers. The axes of the ports of the sub-communication holes opening to the main combustion chambers extend toward the center axes of the throat holes. The axes of the ports of the sub-communication holes opening to the pre-combustion chambers extend offset from the center axes of the pre-combustion chambers. Hence, this gas engine can reduce the compression work, lower the maximum pressure of the compressed air at the end of the compression stroke, prevent the gas fuel from remaining in the pre-combustion chambers, and enhance the air utilization factor, improving thermal coefficient.

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Fujisawa, Japan

Kenro Nakashima