Hitachi Automotive Systems, Ltd.

Hitachi, Ltd.

Kenji Takada

Hiroshi Sekine

Toshio Hori

Seiji Asano

Kunihiko Suzuki

Koji Matsufuji

Mitsuru Nagase

Tomoaki Horii

Shingo Kimura

Hisahiro Ooba

Heikichi Kamoshita

Masahiro Osato

Provided are a novel exhaust pipe temperature estimation device and a sensor heater control apparatus for an exhaust gas sensor using the same that accurately estimates an estimation exhaust pipe temperature when an internal combustion engine is stopped and restarted in response to a change of an environmental condition of the internal combustion engine and controls an operation of a sensor heater based on the estimated estimation exhaust pipe temperature. Thus, at least first correction information Tz based on a change of an exhaust pipe temperature and an elapsed time at stop, second correction information Ty based on a change of an internal combustion engine temperature at the stop of the internal combustion engine, and third correction information Tz based on a change of a cooling degree due to outdoor air during stop from the stop to restart are obtained, an estimation exhaust pipe temperature at the stop is corrected using at least one or more pieces of the correction information at restart of the internal combustion engine to estimate an estimation exhaust pipe temperature at the restart, and an estimation exhaust pipe temperature during an operation of the internal combustion engine thereafter is obtained using the estimation exhaust pipe temperature as an initial value, and further, a heating operation of a sensor heater is started when the estimation exhaust pipe temperature becomes equal to or higher than a predetermined value.

Exhaust pipe temperature estimation device and sensor heater control apparatus for exhaust gas sensor using exhaust pipe temperature estimation device

Provided is a knock detecting device capable of ensuring knock detection accuracy irrespective of fuel injection conditions even when a period during which injection-valve noise occurs overlaps with a knock determination period. An ECUsubjects signals output from a knock sensor, which detects vibrations of an internal combustion engine, to frequency analysis to calculate frequency components (). The ECUcalculates a background level that indicates the average of the frequency components (). The ECUstores, in association with each other, the number of fuel injections, which indicates the number of fuel injections in a predetermined time period during one combustion cycle, with a learning value, which indicates a frequency-component correction amount (). The ECUdetermines the presence or absence of a knock () on the basis of a knock index, which indicates the ratio of the difference between each frequency component and the learning value corresponding to the number of fuel injections, to the background level ().

Knock detecting device

Control device of an internal combustion engine that determines whether or not to perform sensor element heating control of an air-fuel ratio sensor with high accuracy based on the mass of condensed water in an exhaust pipe. The control device computes the rate of change of condensed water mass in an exhaust pipe based on the saturated water vapor pressure and the water vapor partial pressure of exhaust gas, and computes the rate of change of evaporation mass in the exhaust pipe based on the amount of heat which the condensed water receives in the exhaust pipe. The control device updates the mass of condensed water based on the rate of change of condensed water mass and the rate of change of evaporation mass, and determines whether or not to perform heating control by a heating controlling unit based on the updated mass of condensed water.

Control device controlling sensor heating in internal combustion engine

At the start-up of an engine, the ignition timing and the air-fuel ratio are controlled to prevent overload onto the volume of ISC air and decreased torque and torque difference. The fuel condition based on the amount of ignition timing correction to inhibit rotational fluctuation during idling is determined and the fuel quantity based on the result is corrected. Right after an engine has started and until a pilot burner is created in the heat spot of the catalyst, the ignition retard control is mainly executed, and at the time when it is determined that a pilot burner has been created in the catalyst's heat spot, the lean air-fuel ratio control is to be executed instead of the ignition retard control. Furthermore, when the ignition retard control changes to the lean air-fuel ratio control, the state transition control is executed along the equivalent ISC air volume line so as not to cause torque fluctuation.

Fuel control device and fuel control method

Growing community of inventors

Hitachinaka, Japan

Kenji Takada