PARTIAL DRIVING CONTROL TYPE INTERNAL-COMBUSTION ENGINE

PURPOSE:To reduce a pumping loss in time of partial clinder driving despite a simple construction, by installing each intercept valve in a suction passage and an exhaust passage belonging to each suspension side cylinder of a cylinder number control engine, while fully closing both these valves in time of low revolution or low load. CONSTITUTION:Each of suction intercept valves 12 and 13 is installed in suction passages (a branch pipe from a surge tank 3) 7b and 7c leading to each of suction side cylinders 2b and 2c of a cylinder number control engine 1, and each of exhaust intercept valves 14 and 15 is installed in exhaust pipes 11b and 11c. And, using a suction pressure sensor or an engine speed sensor installed in the surge tank 3, fuel feed to these suspended cylinders is intercepted when suction pressure is above the specified value or engine speed is below that, while both intercept valves are fully closed whereby a pumping loss is reduced. Since there is no need to make both suction and exhaust valves hold in full closure, their structure can be thus simplified.