Honda Giken Kogyo Kabushiki Kaisha

Honda Giken Kogyo K.k.

Yoshihiko Kobayashi

Shinichi Kitajima

Toshiyuki Suga

Hiroaki Muramatsu

Teruo Wakashiro

Hiroshi Kitagawa

Hiroshi Maruyama

Toshikatsu Takanohashi

Hiroki Kodama

Toshikatu Takanohashi

In an evaporative fuel control system in an internal combustion engine, a purge gas concentration is estimated by a purge gas concentration estimating device based on an air-fuel ratio correcting factor provided when a purge control valve is in its opened state and an air-fuel ratio correcting factor provided when the purge control valve is in its closed state. A lower limit value of an air-fuel ratio correcting factor, set by an air-fuel ratio correcting factor setting device, is determined by an air-fuel ratio correcting factor limit value setting device in accordance with the purge gas concentration estimated by the purge gas concentration estimating device. Thus, the lower limit value of the air-fuel ratio correcting factor can be varied depending upon the concentration of the purge gas, thereby setting an air-fuel ratio control range corresponding to the concentration of the purge gas.

Evaporative fuel control system in internal combustion engine

An evaporated fuel control system in internal combustion engines includes a canister filled with an adsorbent for adsorbing an evaporated fuel in a fuel tank, a purge amount control device provided in the middle of a purge passage connecting an intake passage and the canister, and a fuel supply device. The purge flow rate from the start of purging is integrated, and the purge amount is reduced to a larger extent in response to a purge amount integration value becoming smaller. This improves the nature of an exhaust gas immediately after the start of purging and the like.

Evaporated fuel control system in internal combustion engine

An evaporative emission control system for an internal combustion engine controls purging of evaporative fuel into the intake pipe of the engine. A first control valve is arranged in a communication passage communicating between a charcoal canister and the intake pipe, for supplying the evaporative fuel to the engine at a flow rate dependent on load on the engine. A second control valve is arranged in a bypass passage bypassing the first control valve for supplying the evaporative fuel to the engine at a predetermined flow rate. When a temperature of the engine is below a predetermined value, the first control valve is closed and at the same time the second control valve is made open, to thereby supply the evaporative fuel to the engine at the predetermined i.e. small flow rate. For a predetermined time period after the engine has been warmed up, the first and second control valves are controlled in the same manner. When the engine is idling as well, the same control of the two valves is carried out.

Evaporative emission control system for internal combustion engines

A system for controlling heater mounted on a spark plug which ignites the air-fuel mixture in the combustion chamber of an internal combustion chamber. The heater-on time is determined such that it decreases with increasing engine temperature and increasing alcohol concentration. Current supplied to the heater is also determined such that it increases with increasing alcohol concentration and decreases with increasing engine temperature. Therefore, droplets at the spark plug caused by high alcohol concentration fuel can be removed while eliminating carbon fouling. The engine startablity can thus been improved without shorting the service life of the spark plug. Moreover, fuel injection amount is reduced so as not another fuel be deposited on a droplet fuel which is still being present. The heater is furthermore kept off when a starter motor is turning to supply sufficient power to the motor.

Spark plug heater control system for internal combustion engine

A air-fuel control system for internal combustion engines using a blended fuel composed of gasoline and alcohol for determining or presuming a correction factor due to alcohol concentration in the fuel when an alcohol sensor for detecting the same has failed. An average value of the O.sub.2 feedback correction factor reflecting a deviation between a target air fuel ratio and an actual air-fuel ratio is obtained and based on it, a target value is determined. The average value is compared with upper and lower limits and when it reaches either one, the factor obtained when the sensor operated properly is adjusted by an amount to follow up the target value.

Air-fuel ratio control system for internal combustion engine

A system according to the invention controls the vaporized amount of a blended fuel composed of gasoline and an alcohol such as methanol and contained in a fuel tank mounted at a vehicular internal combustion engine. The methanol concentration in the fuel is sensed and from the sensed value, reid vapor pressure of the fuel is presumed. The pressure in the fuel tank is then regulated at a target pressure by adjusting the amount of vaporized fuel to be removed from the fuel tank and fed to a canister in response to the presumed reid vapor pressure.

Vaporized fuel control system for vehicular internal combustion engine

A system for controlling supply of fuel to a hybrid fuel powered engine during starting. The system has a sensor detecting the alcohol concentration of the fuel, a device for calculating an alcohol correction factor from the detected alcohol concentration, a device for correcting a basic amount of fuel supply in accordance with the alcohol correction factor, a device for increasing or decreasing the factor in increments of a magnitude determined on the basis of the engine coolant temperature once per interval determined on the basis of the engine coolant temperature, and a device for reversing the direction of the increments each time the factor reaches an upper limit value or a lower limit value, whereby the factor is swept over a prescribed range until the engine starts.

System for controlling fuel supply for internal combustion engine

An air-fuel ratio control system for internal combustion engine using fuel containing alcohol corrects an amount of fuel supplied to the engine by a correction amount dependent on load on the engine when the engine is in a predetermined high load region. The concentration of alcohol in the fuel is detected, and the correction amount is decreased to a smaller value as the detected concentration of alcohol in the fuel is higher.

Air-fuel ratio control system for internal combustion engines

A system for controlling an air/fuel ratio of an internal combustion engine supplied with a blended fuel of gasoline and alcohol and equipped with a blowby gas ventilator. An oxygen sensor is provided and an amount of fuel supply is corrected in response to the detected air/fuel ratio within a range having a lower limit set in the lean direction and an upper limit set in the rich direction. At engine starting, injected alcohol may not vaporize but leak into the crankcase and will then vaporize to pass into the air intake passage along with the blowby gas when the engine temperature rises, causing the air/fuel ratio to be become rich beyond the correction lower limit. For that reason, in this system, engine coolant temperature and alcohol content in the fuel are detected. And if the temperature is within a range defined from the alcohol boiling point when the alcohol content is above a reference value, the lower limit of the range is shifted in the leaner direction. The air/fuel ratio can therefore be corrected in the lean direction.

Air/fuel ratio control system for internal combustion engine

An air-fuel ratio control system for an internal combustion engine using an alcohol blended fuel, in which an alcohol concentration-dependent correction coefficient for use in calculating an amount of fuel supplied to the engine is calcuated in response to concentration of alcohol in the fuel defected by an alcohol concentration sensor. An average value of the correction coefficient is calcuated depending on operating conditions of the engine. The amount of fuel supplied to the engine is calculated by the use of the average value of the correction coefficient to thereby control the air-fuel ratio of an air-fuel mixture supplied to the engine.

Growing community of inventors

Haga, Japan

Yoshihiko Kobayashi