Honda Giken Kogyo Kabushiki Kaisha

Katsuhiko Kimura

Masahiko Asakura

Tomohiko Kawanabe

Minoru Muroya

Noritaka Kushida

Hiroshi Hasebe

Yasunari Seki

Takanori Shiina

Kouji Matsuura

Toshio Shioya

Shin'ichi Kubota

A method for indicating a shift operation for a manual transmission gear includes a step for comparing a detected vehicle speed with a reference speed which is determined and changed on the basis of a detected engine temperature and a step for indicating the shift operation on this basis of a result of the comparison. When a temperature parameter relating to the engine operation is lower than a predetermined reference temperature value, the reference vehicle speed is raised so that the indication of the shift operation will not be generated.

Method of indicating a shift operation of a manual transmission gear of

An apparatus for sensing the concentration of oxygen in a gas such as engine exhaust gas includes an oxygen concentration sensor formed of an oxygen pump element and a sensor cell element, each based on a solid electrolytic member formed of a material such as ZrO.sub.2, and is provided with a limiter circuit which functions to reduce the level of current supplied to the oxygen pump element when a voltage produced by the sensor cell element indicates that this current level is such as to produce a 'blackening' phenomenon whereby deterioration of the oxygen pump element will occur and oxygen concentration sensing reliability will be lowered. The apparatus also includes a delay circuit which functions such that a reduction of the oxygen pump element current level is delayed by a predetermined time interval, after an increase of the sensor cell element voltage to the 'blanking' region is detected, thereby preventing fluctuations in the oxygen pump element current level due to transient increases in sensor cell element voltage and increasing the sensing reliability.

Oxygen concentration sensing apparatus

The valve opening of an exhaust gas recirculating valve is controlled in response to operating conditions of the engine so as to regulate the amount of exhaust gas recirculation to values appropriate to the operating conditions of the engine. The valve opening of the exhaust gas recirculating valve is varied by a predetermined value when the engine is determined to be in a predetermined accelerating condition or a predetermined decelerating condition. Further, the predetermined value is corrected in accordance with the detected shift lever position. Preferably, the valve opening of the exhaust gas recirculating valve is increased or decreased by a predetermined incremental value or a predetermined decremental value when the engine is in the predetermined accelerating condition or the predetermined decelerating condition, and the predetermined incremental value or the predetermined decremental value is corrected in accordance with the detected position of the shift lever.

Exhaust gas recirculation method for internal combustion engines

An air/fuel ratio control system for an internal combustion engine having an air supply system for controlling the air/fuel ratio of mixture to be supplied to the engine, and an oxygen concentration sensing device for sensing the oxygen concentration in the exhaust gas of the internal combustion engine. The oxygen concentration sensing device includes a pair of solid electrolyte members operating as an oxygen pump element to which a pump current is supplied, and a sensor cell element. An open/close valve is provided in the air supply system and controlled by a duty ratio control circuit which causes the open/close valve to be opened for a calculated valve open time period in each of successive predetermined cycles in response to a result of detection of air/fuel ratio. When the calculated valve open time period exceeds a predetermined upper limit, the supply of the pump current is stopped so that the blackening phenomenon of the solid electrolyte members is avoided.

Air/fuel ratio control system for an internal combustion engine with a

Method for controlling an oxygen concentration sensor for sensing an oxygen concentration in an exhaust gas of an internal combustion engine, which sensor includes an oxygen pump element and a heater element, comprises steps for controlling a pump current and a heat current control in response to a result of a detection of engine load. When the engine is operating in a predetermined high load range, the supply of the pump current to the oxygen pump element is stopped, and the heat current to the heater element is reduced when the engine operation in the high load range has continued for more than a predetermined time period. The heater current to the heater element is stopped when the engine load is in a first predetermined load range, and when the engine operation in a second load range which is lighter than the first load range has continued for a predetermined time period.

Method for controlling an oxygen concentration sensor for sensing an

An air intake side secondary air supply system for an internal combustion engine including an open/close valve disposed in an air intake side secondary air supply passage and an oxygen concentration sensor producing an output signal whose level is substantially proportional to an oxygen concentration of the exhaust gas, executes a duty ratio control of the open/close valve for a feedback control of the air fuel ratio of mixture to be supplied to the engine. When the air/fuel ratio has changed from rich to lean with respect to a target air/fuel ratio, a correction value for reducing the valve open period during the air/fuel ratio is detected to be lean, is increased. On the other hand, when the air/fuel ratio has changed from lean to rich with respect to the target air/fuel ratio, a correction value for increasing the valve open period during the air/fuel ratio is detected to be rich, is increased.

Air intake side secondary air supply system for an internal combustion

An oxygen concentration sensing device and an air/fuel ratio control system for an internal combustion engine which include a pair of solid electrolyte members having oxygen ion permeability which are arranged to face each other to form a restricted region between them. One of the solid electrolyte members is operative as an oxygen pump element when a pump current is supplied across the electrodes thereof. The sensing device is provided with a current supply part including a limit command circuit which generates a current stop command signal when the magnitude of the pump current exceeds a reference limit level. With the current stop command signal, the supply of the pump current is stopped so as to prevent an overcurrent to the oxygen pump element. The air/fuel ratio control system includes an air/fuel ratio detection part and an air/fuel ratio control part operated by an air/fuel ratio detection signal. The detection of the air/fuel ratio and the supply of the pump current are stopped under a predetermined operating condition of the engine.

Device for sensing an oxygen concentration in gaseous body with a pump

An air intake side secondary air supply system for an internal combustion engine having an air intake system using a carburetor and an air intake side secondary air supply passage leading to the downstream of the carburetor, and equipped with a fuel increment control system. The system includes an oxygen concentration sensor producing an output signal whose level is substantially proportional to an oxygen concentration of the exhaust gas, and an open/close valve disposed in the air intake side secondary air supply passage controlled in accordance the output signal of the oxygen concentration sensor. The system is adapted close the open/close valve continously to stop the air/fuel ratio control when an operation of the fuel increment control system is detected.

A fuel injection system having a fuel distributor which is connected to a fuel supply tube. The main fuel nozzles are fitted into openings in the lower surface of the fuel distributor and holes in the intake manifold near the main combustion chambers. A holding member supports the mid portion of the fuel nozzles and is connected to the fuel distributor. A fuel branching member is connected to the upper surface of the fuel distributor to supply fuel to the sub fuel injection nozzle. A cap seals the second end of the branched fuel passage from the atmosphere. An accommodating chamber is formed within a holding cylinder which is fitted about the leading end portion of the sub fuel injection nozzle. A fuel mixer is fitted within the accommodating chamber to emulsify the fuel. The emulsion is then injected into the unit sub intake passage through an emulsion tube. A holding member retains the sub fuel injection nozzle about its mid portion and is attached to the fuel branching member. The fuel branching member is attached to the fuel distributor to securely mount the sub fuel injection nozzle. A regulator valve is attached to the branched fuel passage to regulate the fuel pressure of the main injection nozzles and the sub injection nozzles.

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Wako, Japan

Katsuhiko Kimura