摘要:
An engine that re-circulates its exhaust gas suffers decreased accuracy in estimating an EGR rate real-time especially while the operating state of the engine is in a transitional state, which often results in torque fluctuations and deteriorated exhaust gas.A sensor for directly detecting an EGR flow rate is disposed in an EGR path. An EGR rate and in-cylinder oxygen concentration are calculated from the output value of that sensor. In addition, when this EGR rate calculation method is used, the calculation is properly switched between a steady operation state characterized by a low load and small rotational fluctuations and a transitional operating state including the acceleration and deceleration. This makes it possible to correctly estimate the EGR rate and the in-cylinder oxygen concentration under a wide range of engine operation conditions, and thereby to avoid the fluctuation of torque and the deterioration of exhaust gas.
摘要:
An engine that re-circulates its exhaust gas suffers decreased accuracy in estimating an EGR rate real-time especially while the operating state of the engine is in a transitional state, which often results in torque fluctuations and deteriorated exhaust gas.A sensor for directly detecting an EGR flow rate is disposed in an EGR path. An EGR rate and in-cylinder oxygen concentration are calculated from the output value of that sensor. In addition, when this EGR rate calculation method is used, the calculation is properly switched between a steady operation state characterized by a low load and small rotational fluctuations and a transitional operating state including the acceleration and deceleration. This makes it possible to correctly estimate the EGR rate and the in-cylinder oxygen concentration under a wide range of engine operation conditions, and thereby to avoid the fluctuation of torque and the deterioration of exhaust gas.
摘要:
A thermal type gas flowmeter comprising a sensor element which, in turn, comprises at least one first heating resistor, two or more resistors in fluid and a second heating resistor which is disposed between the first heating resistor and a housing supporting the sensor element. The first and second heating resistors are electrically independent from each other. A temperature sensing unit is provided between the first and second heating resistors. A temperature of the first or second heating resistor is controlled by a temperature sensed by the temperature sensing unit.
摘要:
A thermal type gas flowmeter comprising a sensor element which, in turn, comprises at least one first heating resistor, two or more resistors in fluid and a second heating resistor which is disposed between the first heating resistor and a housing supporting the sensor element. The first and second heating resistors are electrically independent from each other. A temperature sensing unit is provided between the first and second heating resistors. A temperature of the first or second heating resistor is controlled by a temperature sensed by the temperature sensing unit.
摘要:
A thermal flow meter corrects flow rate detection errors produced by vaporization of liquid phase components included in a gas to be measured. The thermal flow meter includes a correction circuit 500 that applies respectively different predetermined voltages to heating resistors consisting of first heating resistor Rh1 and second heating resistor Rh2 of a sensor element disposed in the gas to be measured to set a first temperature state and a second temperature state, calculates a first flow rate value Q1 of the gas to be measured in the first temperature state and a second flow rate value Q2 of the gas to be measured in the second temperature state, and calculates a flow rate correction value ΔQ based on a ratio (Q1/Q2) between the first flow rate value and second flow rate value or a fourth-power value (Q1/Q2)4 of the ratio to correct a flow rate of the gas to be measured.
摘要:
A control apparatus of an EGR control valve has an EGR control valve has an exhaust gas recirculation passage to circulate exhaust gas of an combustion engine from an exhaust gas passage to an intake air passage. A measurement unit measures a flow rate of EGR gas flowing in the exhaust gas recirculation passage, and a controller receives an input from the measurement unit and closes the EGR control valve if the EGR-gas flow rate is smaller than a predetermined threshold value when the EGR gas is flowing from the exhaust side to the intake side of the internal combustion engine.
摘要:
A conventional technique performs valve close control of an EGR valve after an EGR-gas back flow is detected. Therefore, the conventional technique has a subject that, if an EGR-gas flow direction changes from forward flow to back flow, a back flow condition will last not only for a response delay time of a detector but also for the judgment time by calculation processing and the actuation time of the EGR control valve. There is provided a control apparatus of an EGR control valve, comprising: an EGR control valve which is provided in an exhaust gas recirculation passage to circulate exhaust gas of an combustion engine from an exhaust gas passage to an intake air passage; measurement means for measuring a flow rate of EGR gas flowing in the exhaust gas recirculation passage; and control means for receiving an input from the measurement means and closing the EGR control valve if the EGR-gas flow rate is smaller than a predetermined threshold value when the EGR gas is flowing from the exhaust side to the intake side of the internal combustion engine.
摘要:
A control device for an engine, capable of accurately estimating the quantity of exhaust heat from the engine and performing engine control which improves the exhaust quality and fuel consumption of the engine in various operating conditions thereof, by using the accurate estimated value of the quantity of exhaust heat. A control device for an engine is provided with an exhaust flow rate sensor for directly sensing the flow rate of exhaust gas discharged from the engine, an exhaust temperature estimating device for sensing or estimating the temperature of the exhaust gas discharged from the engine, and an exhaust heat quantity estimating device for estimating, based on an output of the exhaust flow rate sensor and an output of the exhaust temperature estimating device, the quantity of heat of the exhaust gas discharged from the engine.
摘要:
A control device for an engine, capable of accurately estimating the quantity of exhaust heat from the engine and performing engine control which improves the exhaust quality and fuel consumption of the engine in various operating conditions thereof, by using the accurate extimated value of the quantity of exhaust heat. A control device for an engine is provided with an exhaust flow rate sensor for directly sensing the flow rate of exhaust gas discharged from the engine, an exhaust temperature estimating device for sensing or estimating the temperature of the exhaust gas discharged from the engine, and an exhaust heat quantity estimating device for estimating, based on an output of the exhaust flow rate sensor and an output of the exhaust temperature estimating device, the quantity of heat of the exhaust gas discharged from the engine.
摘要:
There is provided a thermal type flow meter capable of accurately detecting a flow rate even when a fluid temperature varies rapidly or when the fluid temperature is high. A probe includes: a first main heating resistor; a second main heating resistor set at a temperature different from that of the first main heating resistor; and a sub-heating resistor for heating lead wires of the two main heating resistors. A CPU of a sensor control circuit finds a fluid temperature by using the two main heating resistors, and finds a fluid flow rate by using at least one of the two main heating resistors.