Method and apparatus for controlling supercharge pressure for a turbocharger

Claim 1

A method of controlling supercharge pressure for a turbocharger, which comprises the steps of: (a) detecting actual engine speed CN, intake air flow rate Q, supercharge pressure P, etc,; (b) reading a basic control amount D and a target supercharge pressure P s from a look-up table in accordance with operating conditions of the engine thus detected; (c) comparing the actual supercharge pressure P with a predetermined first target value (P s + P o ) of supercharge pressure; (d) comparing the actual supercharge pressure P with a predetermined second target value (P s - P o ) of the supercharge pressure in accordance with the result of the first comparison; (e) maintaining the same control condition as that performed at previous time by adding a previous control amount Δ d to the basic control amount D if the results of said first and second comparisons satisfy a certain condition (P - P o ≦ P < P + P o ); and (f) calculating a feedback correction amount Δ d' by adding or subtracting a predetermined value α to or from the previous control amount Δ d and controlling the opening of a control valve in accordance with the result of the first comparison (P > P + P o ) or the second comparison (P < P - P o ) either in the direction of opening or in the direction of closure of the control valve.

Claim 2

A method of controlling supercharge pressure for a turbocharger, which comprises the steps of: (a) detecting actual engine speed CN, intake air flow rate Q, supercharge pressure P, etc,; (b) reading a basic control amount D and a target supercharge pressure P s from a look-up table in accordance with operating conditions of the engine thus detected; (c) comparing the actual supercharge pressure P with a predetermined first target value (P s + P o ) of supercharge pressure; (d) comparing the actual supercharge pressure P with a predetermined second target value (P s - P o ) of the supercharge pressure in accordance with the result of the first comparison; (e) maintaining the same control condition as that performed at previous time by adding a previous control amount Δ d to the basic control amount D if the results of said first and second comparisons satisfy a certain condition (P - P o ≦ P < P + P o ); and (f) calculating a feedback correction amount Δ d' by adding or subtracting a predetermined value α to or from the previous control amount Δ d and controlling the opening of a control valve in accordance with the result of the first comparison (P > P + P o ) or the second comparison (P < P - P o ) either in the direction of opening or in the direction of closure of the control valve.

Claim 9

An apparatus for controlling supercharge pressure for a turbocharger for supercharging intake air, which comprises: (a) a plurality of detecting means for detecting operating conditions of the engine, such as supercharge pressure, intake air flow rate, etc; (b) a control valve provided at an inlet portion of an exhaust gas turbine for controlling the flow speed of the exhaust gas flowing into the exhaust gas turbine; (c) means for calculating a basic control amount for the control valve in accordance with the operating conditions of the engine; (d) means for setting up at least one target supercharge pressure in accordance with the operating conditions of the engine; (e) means for calculating the deviation between the actual supercharge pressure thus detected and the at least one target supercharge pressure; (f) means for determining a feedback control zone for the control valve in accordance with the operating condition of the engine; and (g) means for correcting the basic control amount in such that the opening of the control valve is controlled so as to reduce the opening when the actual supercharge pressure is lower than the target value, to increase the opening thereof when the actual pressure is higher than the target value, and to maintain the opening thereof to a predetermined value when the actual pressure is equal to the target valve.

Claim 10

An apparatus for controlling supercharge pressure for a turbocharger for supercharging intake air, which comprises: (a) a plurality of detecting means for detecting operating conditions of the engine, such as supercharge pressure, intake air flow rate, etc; (b) a control valve provided at an inlet portion of an exhaust gas turbine for controlling the flow speed of the exhaust gas flowing into the exhaust gas turbine; (c) means for calculating a basic control amount for the control valve in accordance with the operating conditions of the engine; (d) means for setting up at least one target supercharge pressure in accordance with the operating conditions of the engine; (e) means for calculating the deviation between the actual supercharge pressure thus detected and the at least one target supercharge pressure; (f) means for determining a feedback control zone for the control valve in accordance with the operating condition of the engine; and (g) means for correcting the basic control amount in such that the opening of the control valve is controlled so as to reduce the opening when the actual supercharge pressure is lower than the target value, to increase the opening thereof when the actual pressure is higher than the target value, and to maintain the opening thereof to a predetermined value when the actual pressure is equal to the target valve.

Claim 11

An apparatus for controlling supercharge pressure for a turbocharger, which comprises: (a) a plurality of detecting means (6, 25, 26, 27, 28) for detecting operating conditions of the engine, such as intake air flow rate, supercharge pressure, engine speed, etc; (b) a control flap valve (20f) provided at an inlet of an exhaust gas turbine for controlling the flow speed of the exhaust gas flowing into the exhaust gas turbine and having a shaft member (20h); (c) an actuator (20) coupled to said shaft member of said control flap valve through arm and rod means; (d) an electromagnetic valve (24) provided between an liaison path and said actuator for controlling said actuator in accordance with a control signal; and (e) an electronic control unit (23) having a microprocessor including a CPU, a RAM, and a ROM for producing said control signal and for controlling said electromagnetic valve in accordance with the operating conditions of the engine.

Claim 12

An apparatus for controlling supercharge pressure for a turbocharger, which comprises: (a) a plurality of detecting means (6, 25, 26, 27, 28) for detecting operating conditions of the engine, such as intake air flow rate, supercharge pressure, engine speed, etc; (b) a control flap valve (20f) provided at an inlet of an exhaust gas turbine for controlling the flow speed of the exhaust gas flowing into the exhaust gas turbine and having a shaft member (20h); (c) an actuator (20) coupled to said shaft member of said control flap valve through arm and rod means; (d) an electromagnetic valve (24) provided between an liaison path and said actuator for controlling said actuator in accordance with a control signal; and (e) an electronic control unit (23) having a microprocessor including a CPU, a RAM, and a ROM for producing said control signal and for controlling said electromagnetic valve in accordance with the operating conditions of the engine.