Hitachi, Ltd.

Hitachi Automotive Systems, Ltd.

Kenichi Kotabe

Kenji Mizushima

Seiji Asano

Kunihiko Suzuki

Akihito Numata

Eisaku Fukuchi

Shingo Kimura

Sadato Horiuchi

Heikichi Kamoshida

Shigeru Nishita

Makoto Muto

There is provided an engine control device which can accurately calculate a compensation coefficient used for transient compensation of an ignition timing without involving a complicated and large-scale calculation model in order to prevent a combustion deterioration and the like caused by a mechanical response delay and the like of the variable valve timing mechanism at a transition time such as an acceleration/deceleration time. The angular difference between each current real phase of the intake/exhaust valvesandand a target phase set based on an engine load equivalent amount such as an intake air amount is obtained; the shift amount or its correlation value between a current real intake air amount and a theoretical intake air amount value calculated using a pressure inside an intake manifold when each phase of the intake/exhaust valves has reached the target phase is obtained; further a compensation coefficient for matching the shift amount or its correlation value with the angular difference is obtained; and the compensation coefficient is used to perform transient compensation of an ignition timing.

Engine control device

In an apparatus for diagnosing an exhaust gas purifying device, a catalyst deterioration level detectordetects the deterioration level of a catalyst from a relationship between a catalyst-upstream air-fuel-ratio detectorand a catalyst-downstream air-fuel-ratio detector. A catalyst-deterioration-level correction sectioncorrects the catalyst deterioration level detected by the catalyst deterioration level detectorbased on a falling response ratio representing the ratio between a falling response index of the catalyst-upstream air-fuel-ratio detectorand a falling response index of the catalyst-downstream air-fuel-ratio detectoror based on a rising response ratio representing the ratio between a rising response index of the catalyst-upstream air-fuel-ratio detectorand a rising response index of the catalyst-downstream air-fuel-ratio detector. A catalyst deterioration judgment sectiondetermines that the catalyst is deteriorated from information provided by the catalyst-deterioration-level correction section. This allows any deteriorated catalyst to be precisely detected even if an air-fuel ratio sensor downstream of the catalyst is degraded in terms of rising response.

Apparatus for diagnosing exhaust gas purifying device

There is provided an air amount computing unit, and a fuel control unit, of an internal combustion engine that calculates a cylinder flow-in air amount during a transient state without response delay and so as not to have any inflection point in changes of flow rate and that allows a desirable air-fuel ratio to be kept. The air amount computing unit has air amount detecting means for detecting an air amount passing through an intake throttle section of the internal combustion engine, air amount computing means for obtaining a calculated value of the air amount passing through the intake throttle section from an throttle opening angle, means for obtaining an air amount flowing into a cylinder of the internal combustion engine by excluding an air amount filled into an intake manifold by filtering by a difference between a value of the air amount passing through the intake throttle section of this time and a previous filtering value, a first filter based on the air amount detected by the air amount detecting means, a second filter based on the calculated value of the air amount obtained by the air amount computing means, selecting means for selecting an input value and a previous output value of the first filter when the internal combustion engine is in a static state and selecting an input value and a previous output value of the second filter when the internal combustion engine is in a transient state and a third filter for inputting a selected value selected by said selecting means, wherein the output of the third filter is determined to be an air amount flowing into the cylinder.

Air amount computing unit and fuel control unit of internal combustion engine

Growing community of inventors

Mito, Japan

Kenichi Kotabe