GB604295A - Improvements in pre-combustion chamber internal combustion engines - Google Patents

Abstract

604,295. Self-ignition engines. MORRIS, H. L., and ERICSON, G. R. June 8, 1945, 14600. Convention date, April 26, 1944. [Class 7 (iii)] In a self-ignition engine having a precombustion chamber 8 communicating with a main combustion chamber 6 by way of a restricted orifice 9 and a fuel injector 10 injecting substantially the entire fuel charge into the precombustion chamber during the period of the ignition lag and while the pressure in the main chamber is greater than in the precombustion chamber, the dimensions of the restricted passage are such as to control the rate of flow back of the fuel charge from the precombustion chamber to the main chamber whereby the rate of pressure rise in the main chamber does not exceed 50 lbs./sq. inch per degree of crank-shaft travel, the full charge being subjected to partial combustion in the precombustion chamber. The term ignition lag is defined as the theoretical period of time which the same fuel charge as is injected into the precombustion chamber would require to be brought to spontaneous combustion point by the temperature and pressure conditions in the main combustion chamber if the charge were injected into and remained in the main combustion chamber only. The exhaust valve 2 is located in the main combustion chamber. In the case of a four-stroke cycle engine, both the inlet and exhaust valves may be in the cylinder head. The type of fuel nozzle is chosen so as to direct the jet of fuel into the orifice 9. An air jacket 29 surrounds the walls of the precombustion chamber, thereby minimizing cooling of the walls of the chamber and assisting ignition. The fuel injection is timed to take place between 20 degrees and 10 degrees before top dead-centre and the duration of the injection is dependent on the manual or governor control of the amount of fuel supplied. Combustion in the precombustion chamber is started 5 degrees before top dead-centre. The description refers in detail to the pressures, conditions, &c. obtaining within the precombustion' chamber and main combustion chamber at times corresponding to various positions of the piston between 30 degrees before and 15 degrees after top dead-centre.