RU95111033A - Method of operation and control of internal combustion piston engine - Google Patents

Abstract

FIELD: power engineering and mechanical engineering; internal combustion piston engines with supercharging, cooling of supercharging air to temperature of $$$ and igniting of charge from standby source. SUBSTANCE: according to proposed method, medium and high values of supercharging without knocking in four-stroke gasoline engines equal to $$$ and even higher are obtained owing to early closing of intake valve (internal cooling according to Miller's scheme). Essence of method is that intake valve is closed earlier than necessary to prevent knocking and thus improve ecological characteristics of engine with reduction of nitrogen oxides content and provision of possibility of operation on nonleaded gasoline. Ecological effect can be explained as follows. In supercharged engine with supercharging air cooling after earlier closing of intake valve afresh charge expands when piston moves to bottom dead center. Thanks to expansion, temperature of fresh charge $$$ becomes lower than temperature $$$. The higher supercharging, the earlier the intake valve is closed and the lower temperature $$$. So maximum temperature of cycle is lower and knocking tendency is decreased which makes the engine environmentally oriented. Proposed method can be implemented very simply, by synchronously changing the end and beginning of intake, for instance, by control of intake phases by separate camshaft and changing the angle of turning of camshaft relative to crankshaft. EFFECT: enlarged operating capabilities. 29 cl, 2 dwg

Claims (11)

1. The method of operation and regulation of a reciprocating internal combustion engine with pressurization and mainly with cooling of the charge air and ignition from an external source, including forcing the engine to a significant and high pressurization, characterized in that it prevents detonation by early closing of the intake organs, the intake organs being closed earlier than is necessary from the condition of the absence of detonation, i.e., earlier than such an angle of the end of the inlet that detonation occurs at later angles due to an increase in filling the engine with a fresh charge.  2. The method according to p. 1, characterized in that the angle of closure of the intake with an increase in boost is reduced so that the increase in maximum pressure does not exceed 20% compared with the operation mode without boost.  3. The method according to PP. 1 and 2, characterized in that with increasing boost, the closing angle of the intake organs is set earlier from the condition that the maximum combustion pressure is maintained such as on the corresponding naturally aspirated engine.  4. The method according to PP. 1 to 3, characterized in that it is implemented on a four-stroke gasoline engine with intake organs including intake valves, the early closing of which is carried out at least in part of the modes before the BDC.  5. The method according to PP. 1 - 4, characterized in that the closing angle of the intake valve on a warm running engine is set with deviations of not more than ± 10% of the phases specified by the graph of the dependence of the angle of the end of the intake on the degree of pressure increase in the compressor.  6. The method according to PP. 1 - 5, characterized in that when the inlet duct is blocked by spool devices that shut off the duct earlier than the inlet valve closes, the closing angle of these devices is set earlier than that indicated on the graph for the dependence of the end angle of the intake on the degree of increase in pressure in the compressor.  7. The method according to PP. 1 - 6, characterized in that when lowering the degree of boost due to a decrease in the speed, the closing angle of the intake valve is set later than in the nominal mode.  8. The method according to PP. 1 to 7, characterized in that when lowering the boost associated with a decrease in speed, the phase of the overlap of the inlet tract is increased. 9. The method according to PP. 1 to 8, characterized in that the angle of overlap of the inlet tract is set greater than the angle at which the volume of the cylinder is

where V _a is the cylinder volume in the BDC, π _k is the degree of pressure increase in the compressor of the boost unit.  10. The method according to PP. 1 - 9, characterized in that in the compressor carry out a degree of pressure increase of 1.6-2.2, and in the cylinder, the compression ratio is 0.8-1.5 higher than in the corresponding naturally aspirated engine.  11. The method according to PP. 1 to 10, characterized in that the beginning and end of the inlet are changed synchronously, for example, by changing the angle of rotation of the cam shaft, which controls the phases of the inlet (opening the inlet valves).