Nippondenso Co., Ltd.

Tomomi Eino

Toshio Kondo

Akio Kobayashi

Toshihiko Muramatsu

Jun Yamada

Hisashi Iida

Shigenori Isomura

Kiyoshi Nagata

Susumu Harada

Toshihiro Suzumura

Masahiko Tajima

Shuji Sakakibara

Yoshihiro Okuda

Naofumi Fukue

An apparatus for detecting an abnormality of a fuel transpiration prevention system which includes a canister with an absorbing device and a control valve provided in a passage between a fuel tank and an intake pipe of an internal combustion engine so that a fuel gas generated within the fuel tank is absorbed by the absorbing device of the canister and introduced into the intake pipe by opening and closing the control valve in accordance with an operating state of said internal combustion engine. The apparatus includes a pressure detecting device for detecting a pressure within the fuel tank and a deviation calculating unit responsive to the output of the pressure detecting device for calculating a deviation between the pressure detected when the control valve opens the passage and the pressure detected when the control valve closes the passage. The apparatus decides an abnormality of the fuel gas supply system on the basis of the deviation calculated by the deviation calculating unit. This arrangement allows accurate abnormality detection throughout the fuel transpiration prevention system.

Abnormality detecting apparatus for use in fuel transpiration prevention

A fuel injection control for an internal combustion engine having electromagnetic fuel injectors determines a basic fuel injection time width of a fuel injection pulse signal applied to the electromagnetic fuel injectors in accordance with detected conditions of engine operation parameters, stores maximum fuel injection time width values predetermined in correspondence to values of a predetermined one of the engine operation parameters, reads one of the predetermined maximum fuel injection time width values corresponding to the values of the predetermined engine operation parameter and corrects the same in accordance with the values of the other engine operation parameters, and corrects the basic fuel injection time width in accordance with the corrected predetermined maximum fuel injection time width value, thereby controlling the air-fuel ratio at a desired air-fuel ratio under every operating condition of the engine, while simultaneously preventing a misoperation of continuous fuel supply from occuring in the electromagnetic fuel injectors as before.

Fuel injection control

An electronic control system for fuel injection into an engine controls an air-fuel ratio at a desired air-fuel ratio during a high load operation of the engine. The electronic control system performs the operations of detecting operating parameters of the engine, computing by a computing unit a time width in accordance with the detected operating parameters, selecting a maximum time width value of the injection pulse from a preliminarily stored table of maximum time width values thereof in accordance with the value of at least one of the detected operating parameters, comparing the computed time width value with the selected maximum time width value, limiting the computed time width value in accordance with the selected maximum time width value, and applying the injection pulse to the fuel injectors, thereby controlling the air-fuel ratio under the high load conditions at a desired air-fuel ratio and also preventing the malfunction of continuous fuel supply from occurring in the fuel injectors.

Electronic control for fuel injection

The amount of fuel supplied to an internal combustion engine is determined by controlling the opening interval of each fuel injection valve by correcting a standard interval obtained from the amount of intake air and engine speed by first to third correction factors. The first correction factor is dependent on coolant and intake air temperatures, while the second correction factor is dependent on a gas sensor output indicative of the air/fuel ratio of the mixture supplied to the engine. A plurality of third correction factors is provided for different amounts of intake air. Some of the third correction factors corresponding to intake air amounts at which the engine has been operated, are corrected in accordance with the value of the second correction factor. The state of correction is detected and when third correction factor has been corrected in the same direction by a relatively large amount, all of the third correction factors, which have been stored in a memory, are uniformly modified to renew the stored data.

Method and apparatus for controlling air/fuel ratio in internal

In the method of feedback controlling the air-fuel ratio of an internal combustion engine, the feedback control is stopped for a predetermined period of time at a specified time or condition of the engine, and the air-fuel ratio is controlled in accordance with a control signal having a value corresponding to the average value of the integrated compensation signals. In addition, a factor affecting the center value of the controlled air-fuel ratio is adjusted in accordance with the output signal of a comparator circuit generated during the time that the feedback control is being stopped.

Method of feedback controlling air-fuel ratio

A fuel cut-off apparatus is used with an electronically-controlled fuel injection system of the type in which metering of fuel in accordance with the operating conditions of an engine is controlled by the pulse time width of an injection pulse signal applied to electromagnetic fuel injectors. The fuel cut-off apparatus includes a delay circuit, whereby when a fuel cut-off condition is attained during deceleration periods of the engine, the fuel supply to the engine is cut-off after a predetermined time delay.

Growing community of inventors

Kariya, Japan

Tomomi Eino