Patent ID: 8181509
Filing Date: 2012-05-22
Classification: F02B,F02D,Y02T

Abstract:
1. An apparatus for determining an abnormality of a control valve, the apparatus being applied to an internal combustion engine having: a first supercharger comprising, a first turbine disposed in an exhaust gas passage of the engine, and a first compressor disposed in an intake air passage of the engine and driven by the first turbine which is driven by an exhaust gas flowing in the exhaust gas passage; a second supercharger comprising, a second turbine disposed in the exhaust gas passage at a downstream side of the first turbine, and a second compressor disposed in the intake air passage at an upstream side of the first compressor and driven by the second turbine which is driven by the exhaust gas; a first passage section whose one end is connected to the exhaust gas passage at an upstream side of the first turbine and whose the other end is connected to the exhaust gas passage between the first turbine and the second turbine; a first control valve, disposed in the first passage section, for varying a flow passage area of the first passage section depending on an opening degree of the first control valve; a second passage section whose one end is connected to the intake air passage between the first compressor and the second compressor and whose the other end is connected to the intake air passage at the downstream side of the first compressor; and a second control valve, disposed in the second passage section: for opening the second passage section so as to allow an air to pass through the second passage section when a pressure of an air in the second passage section at an upstream side of the second control valve is larger than a pressure of an air in the second passage section at the downstream side of the second control valve by a first pressure or more; and for closing the second passage section so as not to allow an air to pass through the second passage section when the pressure of the air in the second passage section at an upstream side of the second control valve is not larger than the pressure of the air in the second passage section at the downstream side of the second control valve by the first pressure or more, the apparatus for determining an abnormality of a control valve comprising: control-valve-operating-means for operating the first control valve in such a manner that the first compressor compresses an air introduced into the first compressor and discharges the compressed air, when the engine is operated in a first operating area in which a new air amount which is an amount of an air introduced into a combustion chamber from an outside of the engine is smaller than or equal to a first threshold new air amount; pressure-obtaining-means for obtaining: a between-compressors-pressure which is a pressure of an air in the intake air passage between the first compressor and the second compressor; a first-compressor-downstream-side-pressure which is a pressure of an air in the intake air passage at a downstream side of the first compressor and at an upstream side of a pressure loss generating member disposed between the first compressor and the combustion chamber; and a supercharging pressure which is a pressure of an air in the intake air passage at a downstream side of the pressure loss generating member; abnormality-determining-means for determining, if a supercharging-pressure-abnormal-state which is a state where the obtained supercharging pressure is smaller than a referential supercharging pressure determined based on an operating condition of the engine by a second pressure or more occurs when the engine is operated in the first operating area, that: the first control valve is abnormal and the second control valve is normal if the first-compressor-downstream-side-pressure is larger than a first threshold pressure which is larger than or equal to the between-compressors-pressure; and either one of the first control valve and the second control valve is abnormal if the first-compressor-downstream-side-pressure is smaller than or equal to the first threshold pressure.