Nippondenso Co., Ltd.

Kenji Ikuta

Shigenori Isomura

Yukihiro Yamashita

Toshihiro Suzumura

Hisashi Iida

Keigi Honjoh

Takanori Takahashi

In an apparatus for detecting a saturation gas amount absorbed by a catalytic converter disposed in an exhaust system of an engine, an air-to-fuel ratio detecting device is disposed in a region of the engine exhaust system downstream of the catalytic converter for monitoring exhaust gas, which has passed through the catalytic converter, to detect an air-to-fuel ratio of an air-fuel mixture causing the exhaust gas. An air-to-fuel ratio changing device serves to change an air-to-fuel ratio of an air-fuel mixture fed to the engine by a correction quantity in a given direction, and serves to maintain changing the air-to-fuel ratio during a correction time. A change increasing device serves to increase the correction quantity and/or the correction time by the air-to-fuel ratio changing device to execute an air-to-fuel ratio changing process again in cases where the air-to-fuel ratio detected by the air-to-fuel ratio detecting device does not vary even when the air-to-fuel ratio changing device executes changing the air-to-fuel ratio. A saturation gas amount calculating device serves to calculate a saturation gas amount absorbed by the catalytic converter on the basis of the correction quantity and the correction time in cases where the air-to-fuel ratio detected by the air-to-fuel ratio detecting device varies when the air-to-fuel ratio changing device executes changing the air-to-fuel ratio.

Method and apparatus for detecting saturation gas amount absorbed by

In an air-fuel ratio control system for an internal combustion engine, a target air-fuel ratio is set on a side opposite to a direction of deviation of a monitored upstream side air-fuel ratio in such a manner as to counterbalance or offset the deviation of the upstream side air-fuel ratio. The deviation of the upstream side air-fuel ratio may be derived in the form of an mount of a particular component adsorbed in a catalytic converter. A learned value may be used to correct the monitored upstream side air-fuel ratio. Further, a monitored downstream side air-fuel ratio may be used to monitor the setting of the target air-fuel ratio.

Air-fuel ratio control system for internal combustion engine

An air-fuel ratio control system for an internal combustion engine includes two air-fuel ratio sensors, one upstream of a catalytic converter and the other downstream of the catalytic converter. When an output of the downstream air-fuel ratio sensor has been inverted between rich and lean, a target air-fuel ratio is corrected by a skip amount in a direction opposite to that of the inversion. On the other hand, at no inversion, the target air-fuel ratio is corrected by an integral amount in a direction opposite to deviation of the output of the downstream air-fuel ratio sensor. A fuel injection amount is derived based on a differential between the target air-fuel ratio and an output of the upstream air-fuel ratio sensor. An engine operating condition, the output of the downstream air-fuel ratio sensor or a deterioration degree of the catalytic converter may be used to change the skip amount and the integral amount.

An assist air control system for an internal combustion engine introduces, via an assist air passage bypassing a throttle valve, a portion of intake air flowing in an intake pipe upstream of the throttle valve to an area where fuel is injected from a fuel injection valve, so as to facilitate atomization of the injected fuel. The assist air passage includes a flow control unit for opening and closing the assist air passage. The degree of opening of the assist air passage is limited to a value that is reduced as an engine temperature increases, while increased as an engine load increases. The opening degree of the flow control unit may be controlled electrically, mechanically, or both. In this case, the electrically controlled opening degree value is set smaller than the mechanically controlled opening degree value.

Assist air control system for internal combustion engine

In a fuel injection system for an internal combustion engine, engine cylinders are divided into a plurality of cylinder groups. An air passage is provided for supplying mixing air to areas near injection holes of fuel injection valves so as to facilitate atomization of fuel injected from the respective fuel injection valves. The air passage is opened synchronously with a fuel injection of each fuel injection valve such that the mixing air is selectively distributed to the above-noted areas per cylinder group. The mixing air is distributed for such a cylinder group that includes the engine cylinder being injected with the fuel from the corresponding fuel injection valve. The air passage includes a branch portion for the distribution of the mixing air to the above-noted areas. Capacities of the air passage from the branch portion to the respective fuel injection valves may be set substantially equal to each other so as to further facilitate the atomization of the injected fuel.

Fuel injection system for multi-cylinder internal combustion engine

A fuel injection system for an internal combustion engine introduces, via an air passage bypassing a throttle valve, a portion of intake air flowing in an induction system of the engine to an area where fuel is injected from a fuel injection valve, so as to facilitate atomization of the injected fuel. The air passage includes therein a flow control unit for opening and closing the air passage. During an engine idling, a total opening time of the air passage effected by the flow control unit is variably controlled for adjusting a supply mount of the intake air through the air passage so as to realize a target idling engine speed. As a result, the intake air fed through the air passage works not only to facilitate the atomization of the injected fuel, but also to control the idling engine speed to the target value.

Fuel injection system for internal combustion engine

A fuel injection system for a multi-cylinder internal combustion engine is provided. This fuel injection system includes a plurality of fuel injection valves each arranged to inject fuel into an intake port of each cylinder of the engine, an air passage connected to a portion of an air intake passage leading to the intake ports, a plurality of branch air passages each communicating with a preselected portion around an injection nozzle of each fuel injection valve, an air control valve, connecting between the air passage and the plurality of branch air passages, for selectively introducing a portion of intake air in the air intake passage to the preselected portions around the injection nozzles of the fuel injection valves. The air control valve is arranged to selectively assume first and second valve positions, the first valve position being to establish communications between the air passage and the branch air passages in sequence according to rotation of the engine, the second valve position being to establish communication between the air passage and all the branch air passages to supply the intake air in the air passage uniformly to all the branch air passages when an opening period of time during which one of the fuel injection valves is open partly overlaps with that of another fuel injection valve.

An engine temperature is measured an opening of a door is detected so an electrical conduction is made to a heater for heating a sensor element by setting a target element temperature to a relatively high level if such engine temperature (cooling water temperature Thw) is relatively low or, on the other hand, by setting the target element temperature to a relatively low level if the cooling water temperature is relatively high. Then the element temperature is detected and the heater is turned off when the element temperature has reached the target temperature.

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Rolling Hills Estates, CA, United States of America

Kenji Ikuta