| 摘要 |
PURPOSE:To save the fuel cost by enlarging the partial load operation zone by a method wherein unidirectional valves are provided between the negative pressure chambers of the valve driving actuators and an air intake pipe of the partial operation control type internal combustion engine provided with an air intake interrupting valve and an exhaust air returning valve. CONSTITUTION:The titled internal combustion engine comprises a first cylinder group A and a second cylinder group B. The first cylinder group A is connected with the air intake interrupting valve 26 and the exhaust air returning valve 61 such that when the engine is in a low load operation condition, the valve 26 closes to interrupt the supply of fuel while the valve 61 opens, and the second cylinder group B is operated constantly. In the above type of engine, the unidirectional valves F1 and F2 are provided in conduit pipes, repectively, between the first and second negative pressure chambers 33 and 34 of the negative pressure diaphragm 30 for driving the air intake interrupting valve 26, and the surge tank 13 and the unidirection valve F3 i provided between the negative pressure diaphragm 54 of the exhaust air returning valve 61 and the surge tank 13. Thus, with the above arrangement, when the engine shifts from its low load operation to its high load operation, the negative pressure in the above mentioned negative pressure chambers are maintained by the peak negative pressure within the surge tank 13 so that the load on the engine at the time of the engine shifting to its full cylinders operation can be increased. |
