Nippondenso Co., Ltd.

Minoru Hotta

Hiroshi Ikeda

Yasuhito Takasu

Masahiko Tajima

Kouichi Shimizu

Keiji Wakahara

Yoshinori Maegawa

An open/close means M1 opens or closes an EGR passage. An engine load detecting means M2 detects an engine load, such as an intake air amount or an intake air pressure. Either an open. condition or a closed condition of the open/close means M1 is specified as a referential state, while the other is specified as a non-referential state. A memory means M3 memorizes engine loads at the referential state and the non-referential state. A constant acceleration judging means M4 makes a judgement as to whether or not the operational condition of the engine is in a constant accelerating condition. An open/close control means M5 switches the open/close means M1 from the referential state to the non-referential state in response to a constant accelerating condition detected by the constant acceleration judging means M4. An estimating means M8 calculates an estimated engine load to be measured if the open/close means M1 is maintained at the referential state under the continuous constant accelerating condition at the time an actual engine load is detected in the non-referential state, based on a plurality of detection values of the engine load values memorized in the referential state. An abnormality judging means M7 compares the estimated engine load calculated by the estimating means M6 with the actual engine load detected in the non-referential state, thereby making a judgement as to whether the exhaust gas recirculating operation is normal or abnormal.

Exhaust gas recirculation system

An apparatus for detecting a misfire in an internal combustion engine for a vehicle includes a rotational speed change quantity computing unit which detects a rotational speed of the engine and computes a change quantity of the rotational speed of the engine, a misfire determination value correction coefficient setting unit which detects a load on the engine and sets a correction coefficient of a misfire determination value based on a result of detection of the engine load, a misfire determination value setting unit for setting a misfire determination value based on the set misfire determination value correction coefficient, and a misfire determining unit for determining whether a misfire has occurred in the engine by comparing the change quantity of the rotational speed of the engine from the rotational speed change quantity computing unit with the misfire determination value from the misfire determination value setting unit. The misfire detecting apparatus further includes a misfire detection result invalidating unit for invalidating a result of misfire determination by the misfire determining unit.

Apparatus for detecting misfire in internal combustion engines for

A knock control system which detects a knock occurring in an engine, a knock detector for detecting the occurrence of the knock in accordance with a knock sensor signal produced by the sensor, a first adjuster for adjusting knock control factors so as to suppress the knock on the basis of a detected signal from the knock detector, a converter for converting the knock sensor signal so as to make the frequency distribution of the knock sensor signal equal to an exponential distribution, a standard deviation calculator for calculating the standard deviation of the exponential distribution, and a second adjuster for adjusting knock control factors so that this standard deviation reaches a predetermined value, whereby the standard deviation of the frequency distribution of the knock sensor signal can be easily detected, thus making it possible to reduce the load on the electronic control system and prevent the knock detection precision from being reduced by the characteristic change of the knock sensor, engine.

Growing community of inventors

Nagoya, Japan

Minoru Hotta