Internal combustion engine with an auxiliary combustion chamber

摘要

Disclosed is an internal combustion engine having no intake throttle valve and comprising a main chamber and an auxiliary chamber which are interconnected with each other via a connecting passage. An annular raised portion is formed on the inner wall of the auxiliary chamber, and the auxiliary chamber is divided into a first auxiliary chamber and a second auxiliary chamber by the annular raised portion. The connecting passage is tangentially connected to the inner wall of the second auxiliary chamber. The nozzle of a fuel injector is disposed in the auxiliary chamber and is directed to the recess which is formed in the second auxiliary chamber beneath the annular raised portion at a position located opposite to the inner wall to which the connecting passage is tangentially connected with respect to the axis of the auxiliary chamber. The spark gap of a spark plug is located in the recess of the second auxiliary chamber. The sum of the volumes of the auxiliary chamber and the connecting passage is more than 80 percent of the sum of the volumes of the auxiliary chamber, the connecting passage and the main chamber when said piston reaches the top dead center position. The exhaust gas is recirculated into the intake system of the engine so that the exhaust gas recirculating rate becomes 30 through 40 percent. The amount of the fuel injected from the injector is so regulated that the total air-fuel ratio is increased to within 30 through 100:1 in accordance with a decrease in the level of the load of the engine. The ignition timing is advanced to within the range of 15 through 50 degrees before the top dead center position of the compression stroke in accordance with a decrease in the level of the load of the engine.