Nippondenso Co., Ltd.

Toyota Jidosha Kabushiki Kaisha

Brother Kogyo Kabushiki-kaisha

Toyota Jidosha Kogyo Kabushiki Kaisha

Toshiaki Mizuno

Mitsunori Takao

Shinichi Abe

Mitsuharu Taura

Mamoru Imaizumi

Hisamitsu Yamazoe

Hidetoshi Amano

Masumi Kinugawa

Hiroki Matsuoka

Hiroshi Haraguchi

Norio Omori

Tasuku Sugimoto

Tomoaki Abe

Shinji Kimura

Toshihiko Muramatsu

Masao Yonekawa

Mikio Sakuma

Toshiaki Sugiura

Kazushi Nakashima

Katsushi Kato

Kenichi Nagase

Akihiro Nakashima

Hirotaka Nakatsuka

Takayuki Kamada

Katuhiko Kodama

Kazuhiro Murakami

Yoshihiro Sakashita

Shinji Iwamoto

Masami Ogata

An improved fuel injection control apparatus, in which a reference pressure is provided to a pressure regulator, for simplifying the fuel supply system by preventing the fuel quantity injected from injection valves into an engine from being influenced by variations in the air intake pressure. A pressure regulating device disposed in a fuel supply pipe between a fuel pump and the fuel injection valve regulates the pressure of fuel supplied from the fuel pump to the fuel injection valve so that the pressure is proportional to the predetermined pressure, without returning fuel from the injection valve to the fuel tank. An intake pressure detecting device detects the pressure in the intake pipe, and a fuel injection quantity correcting device corrects the fuel injection quantity according to deviations of the fuel pressure regulated by the pressure regulating device from a proper value due to the differential pressure between the pre-determined pressure of the pressure regulating means and the intake pressure. Accordingly, he fuel injection quantity injected from the injection valve is corrected based on the operating condition of the engine due to the variation of the intake pressure. As a result, the fuel supply system is simplified.

Fuel injection control apparatus

A catalyst deterioration detection apparatus having oxygen sensors disposed in the upper stream and the lower stream from a ternary catalyst disposed in the exhaust system of an internal combustion engine, controlling so as to make the air/fuel ratio of the internal combustion engine to be in the neighborhood of a theoretical air/fuel ratio in response to an output signal from at least either of the oxygen sensors, detecting a response delay time from a moment an output signal from the upper stream oxygen sensor has been changed to a moment an output signal from the lower stream oxygen sensor has been changed when the air/fuel ratio of the internal combustion engine is changed from the rich side to the lean side or from the lean side to the rich side, and discrimination that the catalyst has deteriorated if the response delay time is shorter than a predetermined value, the catalyst deterioration detection apparatus including a device for permitting the catalyst deterioration detection apparatus to perform the detection operation if a fact that the internal combustion engine is in a predetermined operation state has been detected and a fact that the air/fuel ration has been converged to the neighborhood of the theoretical air/fuel ratio has been detected.

Apparatus for detecting deterioration of catalyst

A paper edge detecting device for a printing apparatus in which a paper margin of a print paper can be detected with high accuracy. A mark printing process is executed upon power-on of a printer, so that a carriage is displaced from an original position H0 to a position corresponding to a set pulse number H.sub.P and stopped at that position to print on the print paper a linear mark M aligned in a direction perpendicular to a displacement direction of the carriage. Thereafter, a mark detection process is executed, and the carriage is displaced from the original position H0 until the mark M is detected by the photosensor. Subsequently, a correction amount generating process is executed to calculate a correction value .alpha. on the basis of the set pulse number H.sub.P and the count value C.sub.P when the mark M is detected by the photosensor.

Paper margin detecting device for use in printing apparatus

An automotive air conditioner controller for controlling the operation of an automotive air conditioner employing a variable displacement compressor capable of gradually or continuously varying its displacement. While the engine of the automobile is idling, the automotive air conditioner controller adjusts the displacement of the compressor to or near to the maximum, varies desired idling speed of the engine according to required cooling ability, and adjusts the actual idling speed of the engine to the desired idling speed. Thus, the engine operates at an improved fuel consumption rate without reducing the cooling ability of the automotive air conditioner.

Apparatus for controlling automotive air conditioner

A sheet detection apparatus is provided which determines the presence or absence of a sheet on a sheet feed path as well as the type of sheet. The apparatus utilizes a light source to direct a predetermined amount of light to a sensor by reflecting off a sheet on the feed path or a reflector in the absence of any such sheet on the path. The presence or absence of the sheet is determined by comparing the output value of the sensor with predetermined reference values.

Sheet detection apparatus with reflecting member

In an abnormality detection apparatus for vehicle engines, a deceleration discriminating circuit discriminates a deceleration state of a vehicle engine on the basis of a running state of the engine detected by a running state detector for detecting a running state of the vehicle engine. When the deceleration discriminating circuit determines that the engine is being in deceleration state, a comparing circuit compares a vehicle speed detected by a vehicle speed detector with a predetermined value. An abnormality deciding circuit is responsive to a comparison result signal from the comparing circuit to decide abnormality of the vehicle speed detector.

Abnormality detection apparatus for vehicle engines

Disclosed is a method of controlling the air-fuel ratio of an air-fuel mixture to be supplied to an internal combustion engine by the selective use of either one of a feedback control mode in which the control is made to maintain the air-fuel ratio at the stoichiometric level and a lean control mode in which the control is made to maintain at the leaner side of the stoichiometric level in accordance with the state of operation of the engine. In this method, the execution of the control in the lean control mode is prohibited for a predetermined period of time during acceleration of the engine at least when the speed of vehicle mounting the engine is below a predetermined speed, and the air-fuel ratio control is made in the feedback control mode in the period of time. Consequently, the period of engine operation in the lean control mode is maximized without impairing the driveability of the engine particularly when the engine is accelerated from low speed. Disclosed also is an apparatus suitable for carrying out this method.

Method for controlling air-fuel ratio for internal combustion engine and

In an internal combustion engine equipped with exhaust gas recirculation system, air/fuel ratio control is effected using various engine parameters including atmospheric pressure. To this end, basic fuel injection duration is first computed, and this basic fuel injection duration is corrected using a correction factor so that a desired air/fuel ratio is obtained irrespective of the change in atmospheric pressure. When EGR is performed a first correction factor is derived or calculated using engine speed data, intake pressure data and atmospheric pressure data. When EGR is not performed, a second correction factor is derived or calculated using atmospheric pressure data. When obtaining the first correction factor, interpolation is used to obtain the value thereof suitable for detected engine speed, intake pressure and atmospheric pressure.

Apparatus for controlling air/fuel ratio for internal combustion engine

The basic fuel injection time duration or the basic injector opening time is computed on the basis of an intake pressure and an engine speed. A start temperature correction value is selected on the basis of the engine temperature at the time of or immediately after the start up of the engine and attenuated in accordance with the time elapsed after the start up of the engine, such that, the lower the engine temperature is at the time of start up, the greater the start temperature correction value is. The rate of fuel injection rate is controlled by correcting the basic fuel injection time on the basis of the start temperature correction value and a condition of the engine.

Method and apparatus for controlling fuel injection rate in internal

Disclosed is a method of controlling the air-fuel ratio of an air-fuel mixture to be supplied to an internal combustion engine. The method employs a feedback control in which the control is made to maintain the air-fuel ratio at the stoichiometric level in accordance with the air-fuel ratio read through the detection of a component of the exhaust gas and, at least during the idling of the engine after the warming up of the same, a lean control in which the control is made to maintain the air-fuel ratio at the leaner side of the stoichiometric level. The lean control is allowed when the mean value of the engine speed over a predetermined period is greater than a predetermined reference value during the idling after warming up of the engine, while the feedback control is conducted when the mean value is below the predetermined reference value. Disclosed also is an apparatus suitable for carrying out this method.

Method and apparatus for controlling air-fuel ratio in internal

Fuel injection modes including an independent injection mode, group injection mode and simultaneous injection mode are changed over in accordance with an engine operating condition, for example, a load condition. The independent injection mode is selected when the engine is operating in a low load condition, and the fuel injection timing for each cylinder is controlled independently. When the low load condition of the engine changes to an intermediate load condition, the group injection mode is selected and the fuel injection timing is controlled for each group of cylinders formed by grouping the cylinders into at least two groups. The simultaneous injection mode is selected when the intermediate load condition changes to a high load condition, and the fuel injection timing for all the cylinders is controlled to be simultaneous.

Fuel injection mode control for multi-cylinder internal combustion engine

The air-fuel ratio of an air-fuel mixture to be supplied to a combustion chamber is controlled in accordance with a feedback control mode or a lean control mode. In the feedback control mode, the air-fuel ratio is feedback-controlled to be maintained around the stoichiometric air-fuel ratio. In the lean control mode, the air-fuel ratio is controlled to be maintained at a leaner side of the stoichiometric air-fuel ratio. Ignition plugs are ignited at a first ignition timing which is comparatively advanced in the lean control mode and at a second ignition timing which is behind the first ignition timing in the feedback control mode. The ignition plugs are ignited at the second ignition timing for a predetermined period of time after switching from the lean control mode to the feedback control mode and at the first ignition timing for a predetermined period of time after switching from the feedback control mode to the lean control mode.

Method of and apparatus for controlling air-fuel ratio and ignition

The amount of engine acceleration is detected as the amount of change in the absolute pressure in the intake passage, and an asynchronous fuel injection is conducted regardless of the crank position as the amount of acceleration exceeds a predetermined reference value. In ordinary state of engine operation, the synchronous fuel injection is conducted in synchronism with the crank rotation such that the air-fuel ratio of the mixture coincides with the stoichiometric one, upon sensing the air-fuel ratio from the content of oxygen remaining in the exhaust gas. The mixture is made richer or leaner than the stoichiometric one in accordance with the state of operation of the engine. The judging level for the judgement as to whether the asynchronous fuel injection is necessary or not is increased or decreased in accordance with the air-fuel ratio so that the asynchronous fuel injection is conducted taking into account also the air-fuel ratio.

Method of and device for controlling fuel injection in internal

In accordance with an amount of a change or a proportion of the change of at least one of operating parameters, such as a crankshaft rotational speed, an intake pipe pressure, etc., of an internal combustion engine equipped with an electronically controlled fuel injection system, or a rate of incremental change of the amount of the change or the proportion of the change and in dependence on whether air-fuel ratio feedback compensation by the use of an oxygen sensor is effected or not, at least one of control variables, such as a fuel injection quantity, ignition timing, etc., is corrected to ensure stable control of the rotational speed of the engine during its idling and low speed operations.

Method and apparatus for controlling internal combustion engines

Engine operating parameters are detected to see whether the engine is in idle state or not. Then the speed of the engine is detected to determine whether engine speed is varying or not. To this end, a plurality of engine speed data are averaged to find an average engine speed which will be used as a reference value for the comparison with respect to a latest instantaneous engine speed. Ignition timing is either retarded or advanced for maintaining the engine speed at a desired value in such a manner that the amount of correction of the ignition timing is determined by deriving data from a memory in which relationship between the engine speed variation and ignition timing correction amount is stored in the form of a map. In the case that the average engine speed is far deviated from a setting engine speed, the average value is not used as the reference value, but rather the setting speed is used to find the difference. In the case that no setting engine speed is provided, the average engine speed is always used as the reference value. In addition to ignition timing control, the airflow bypassing the throttle valve may be controlled so that idle engine speed does not fluctuate.

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Nagoya, Japan

Toshiaki Mizuno