Internal combustion engine combustion diagnosis/control apparatus and combustion diagnosis/control method

An apparatus for diagnosing and controlling combustion of an internal combustion engine including a gas engine which is constituted such that fuel gas is mixed with air and burned in the combustion chamber, wherein are provided;

• a cylinder pressure detector for detecting the pressure in said combustion chamber,
• a crank angle detector for detecting crank rotation angles of the engine,
• a means(step) for calculating the pressure difference P between detected cylinder pressure P and the reference pressure Pb at or before the beginning of compression including inlet pressure(P=P−Pb) from the cylinder pressure detected by said cylinder pressure detector for every crank angle,
• a means (step) for calculating standardized pressure ratio which is the ratio of said pressure difference P to the pressure difference P0, i.e. P/P0, P0 being the pressure difference between the pressure P0 at one or a plurality of predetermined crank angles in the compression stroke and said reference pressure Pb (P0=P−Pb)
• a means (step) for diagnosing the condition of combustion such as the cylinder pressure condition in said combustion chamber using said standardized pressure ratio P/P0, and
• a combustion control apparatus for controlling the combustion condition of the engine on the basis of the result of the combustion condition diagnosis outputted from the combustion condition diagnosis means (step).

An apparatus for diagnosing and controlling combustion of an internal combustion engine including a gas engine which is constituted so that fuel gas is mixed with air and burned in the combustion chamber, wherein are provided;

• a cylinder pressure detector for detecting the pressure in said combustion chamber,
• a crank angle detector for detecting crank rotation angle of the engine,
• a means(step) for calculating the pressure difference P between detected cylinder pressure P and the reference pressure Pb at or before the beginning of compression including inlet pressure (P=P−Pb) from cylinder pressure detected by said cylinder pressure detector for every crank angle in said combustion crank angle range,
• a means (step) for calculating standardized pressure ratio which is the ratio of said pressure difference P to the pressure difference P0, i.e. P/P0, P0 being the pressure difference between the pressure P0 at one or a plurality of predetermined crank angles in the compression stroke and said reference pressure Pb (P=P−Pb),
• a combustion diagnosis apparatus provided with a pressure/analog voltage converting means(step) for outputting at least a part of the result of diagnosis as analog information when diagnosing the condition of combustion such as cylinder pressure condition in said combustion chamber using said standardized cylinder pressure ratio P/P0 and
• a combustion control apparatus for controlling the combustion condition of the engine by reconverting the analog information outputted from said combustion diagnosis apparatus to pressure information.

An apparatus for diagnosing and controlling combustion of an internal combustion engine including a gas engine which is composed so that fuel gas is mixed with air to be burned in its combustion chamber, provided with a cylinder pressure detector to detect the pressure in the combustion chamber, a crank angle detector to detect the crank rotation angle of the engine, and a displaying apparatus to display the cylinder pressure curve, wherein

• a first ring memory for memorizing the cam top crank angle of a reference cam and the cylinder pressure-crank angle curve is provided on the diagnosis apparatus side,
• a second ring memory for memorizing the cylinder pressure-crank angle curve in a certain crank angle range of each cylinder and a single displaying part are provided on the displaying apparatus side,
• the first ring memory on the diagnosis side has a means (step) to start the program by the interrupt of the signal from the crank angle detector after the detection of the cam top crank angle of the reference cam and write in the cylinder pressure wave form, which indicates combustion condition, at a certain interval of crank angle to the ring memory in the determined area corresponding to each cylinder, and
• the pressure-crank angle curves of all cylinder are read out from the determined area of the second ring memory and these pressure curves are displayed on said single displaying part with the pressure curves shifted so that each curve does not overlaps.