Nippondenso Co., Ltd.

Denso Corporation

Toyota Jidosha Kogyo Kabushiki Kaisha

Toyota Jidosha Kabushiki Kaisha

Hideaki Norimatsu

Akira Masuda

Mitsuo Nakamura

Toshio Kondo

Sigenori Kitajima

Nobuyuki Kobayashi

Akio Kobayashi

Nobuya Watabe

Eiji Takemoto

Yoshihiko Tsuzuki

Nobuhito Hobo

Masahiko Miyaki

Masahiko Tajima

Yoshimune Konishi

Yoshiaki Sato

Nobuyuki Ito

Sigenori Isomura

Sigenori Kitazima

Eizi Matumoto

Koichi Furuta

An illumination device has an illumination unit which glows when current flows through a load thereof, at least one instruction unit for instructing the illumination unit to glow, a PWM signal generating unit which generates a plurality of PWM signals based on that the instruction unit instructed the illumination unit to glow, and a time difference setting unit for setting a time difference between one of the plurality of PWM signals and an other thereof based on that the instruction unit instructed the illumination unit to glow. The load of the illumination unit is divided into a plurality of portions which are respectively connected with each other in parallel and connected with the PWM signal generating unit. The plurality of PWM signals are generated for currents flowing through the plurality of divided portions of the load of the illumination unit.

Illumination device

Provided is a tire air pressure monitoring system capable of sufficiently lowering the electric power dissipation in a monitoring unit. The monitoring unit acquires, on the basis of information on transmission intervals included in transmitted signals from sensor units, the next transmission timings of signals to be transmitted from the sensor units and is switched from a sleep mode to a waking-up mode to receive the transmitted signals from the sensor unit in synchronism with the next transmission timings. This can efficiently set the monitoring unit in a waking-up condition, i.e., a signal receivable condition, thereby preventing useless electric power dissipation and reducing the electric power consumption.

Tire air pressure monitoring system

A tire internal pressure monitor ECU is switched between a monitoring mode where internal pressures of tires of a vehicle are monitored, and a registering mode where ID codes assigned to sensor units provided in the tires are registered. In the registering mode, when receiving the ID code from the sensor unit, the ECU registers the ID code along with instructing an auxiliary device to operate a predetermined conduct that can be seen from an outside of the vehicle. Namely, the predetermined conduct of the auxiliary device notifies completion of registering the ID code, which results in enhancing operation efficiency in registering of the ID code.

Tire internal pressure monitor system and ID code registering method in the same

A fuel injection pump is described wherein a plunger is rotatingly and reciprocally movable in an enclosure to define a compression chamber which is connected to a fuel inlet during an intake stroke of the plunger and to a fuel outlet during a compression stroke thereby to initiate injection of fuel to the outlet. A solenoid valve is responsive to a voltage applied from a voltage source for providing a pressure relief action on the fuel in the compression chamber. A control unit is responsive to the onset of fuel injection to determine a basic timing at which fuel is to be terminated and corrects the basic timing as a function of the source voltage to compensate for a voltage variation thereof which would otherwise affect on the operation of the solenoid valve. The solenoid valve is then energized at the corrected timing.

Fuel injection pump having voltage variation compensation

The air-to-fuel ratio of a combustible mixture supplied to an engine is controlled by a feedback loop which includes an integration circuit for integrating the output signal of an oxygen sensor which detects the oxygen concentration in the exhaust gases of the engine, to produce an output voltage. The output of the sensor is applied to the integration circuit through a switch which opens in response to predetermined conditions of the engine whereby the output voltage of the integration circuit is held at a value occurring just before the switch opens.

Air-to-fuel ratio correcting arrangement in a fuel supply control system

A system for controlling an oxygen concentration in exhaust gases emitted from a combustion engine. An oxygen sensor which changes a resistance in response to a sensed presence and absence of oxygen in exhaust gases is connected in series with an electric power source and a transistor to produce an output voltage indicative of the sensed presence and absence of oxygen. A comparator compares magnitudes of the sensor output voltage with a predetermined magnitude. In response to an output voltage of the comparator, the transistor controls a biasing current flowing from the electric power source to the sensor so that, when either presence or absence of oxygen is sensed, the sensor output voltage is kept substantially at the predetermined magnitude irrespective of temperature dependent changes in the resistance of the oxygen sensor.

System for controlling an oxygen concentration in exhaust gases

An air-fuel ratio control system comprises a first oxygen concentration detector arranged upstream of a three-way catalyst for purifying the exhaust gas in the exhaust system of an internal combustion engine, a second oxygen concentration detector arranged downstream of the three-way catalyst, a discrimination circuit for detecting and discriminating a specific operating condition of the internal combustion engine in response to a signal representing operating factors of the internal combustion engine such as the amount of intake air and vehicle speed, and a change-over circuit impressed with the signals from the first and second oxygen concentration detectors. The change-over circuit produces selectively the detection signal of the second oxygen concentration detector in response to the output signal of the discrimination circuit only when the discrimination circuit detects a predetermined operating condition of the internal combustion engine, and the detection signal of the first oxygen concentration detector when the internal combustion engine is under the other operating conditions.

Air-fuel ratio control system

An air-fuel ratio control system comprises a comparator circuit for comparing a predetermined reference level with an output signal of a first oxygen sensor disposed upstream of a three-way catalyst for purifying the exhaust gas in the exhaust system of an internal combustion engine, the comparator circuit producing a signal indicative of whether the output signal of the first oxygen sensor is higher (lean) or lower (rich) than a predetermined air-fuel ratio, a delay circuit for delaying at least one of the output signals of the comparator circuit, and a delay time adjusting circuit for adjusting the delay time of the signal delayed by the delay circuit, in accordance with the value of the output signal of a second oxygen sensor disposed downstream of the three-way catalyst.

A closed-loop air-to-fuel ratio control system having an oxygen responsive sensor and a feedback circuit. The sensor is disposed in an exhaust passage to produce a voltage indicative of the oxygen concentration in the exhaust gas. This voltage is integrated in the feedback circuit with the integration constant predetermined to vary with respect to the time. Air-to-fuel ratio of the mixture to be supplied to the engine is corrected to the predetermined air-to-fuel ratio in response to the integrated voltage. With the integration constant decreasing with respect to the time, the air-to-fuel ratio is speedily returned to the predetermined ratio.

Method and system to control the mixture air-to-fuel ratio

The combination of a fuel supply system, an exhaust gas oxygen concentration sensor, a feedback control circuit connected to the fuel supply system and to the exhaust gas oxygen concentration sensor, a disabling circuit connected to the feedback control circuit and a fuel increment signal generating circuit connected to the fuel supply system and the disabling circuit. The combination controls the air-fuel mixture to be supplied to the engine. The combination is speed sensitive, i.e., when a predetermined engine speed is exceeded, the disabling circuit disconnects the feedback control circuit from the fuel supply system and the fuel increment signal generating circuit generates a signal which is applied to the fuel supply system in order to increase the fuel quantity supplied by the fuel supply system.

Air-fuel ratio feedback control system

In an air-to-fuel ratio feedback control system of the type in which the output detection signal of an air-to-fuel ratio detector adapted to detect the concentration of an exhaust gas constituent of an internal combustion engine is compared with a preset value in a comparison circuit whose output signal in turn is utilized to feedback control the air-to-fuel ratio of mixture supplied to the engine, the preset value of the comparison circuit is changed to another value in response to the occurrence of a condition which requires the stopping of the feedback control of the air-to-fuel ratio of mixture supplied to the engine, thereby preventing the occurrence of malfunction during transient periods such as the periods of opening and closing of the feedback control system loop.

Air-to-fuel ratio feedback control system with improved transitions

In an air-to-fuel ratio feedback control system, air-to-fuel ratio of mixture supplied to an engine is controlled to be stoichiometric in response to the oxygen concentration in exhaust gases during normal operating conditions of the engine, whereas it is controlled irrespective of the oxygen concentration during specific operating conditions such as heavy load and no load conditions of the engine. Sensor output signal indicative of the oxygen concentration which is integrated to control the air-to-fuel ratio is cut off and integrator output signal is increased or decreased by a predetermined value during the specific conditions so that the mixture is controlled to be richer or leaner as desired than the stoichiometry.

Air-to-fuel ratio feedback control system for internal combustion engines

A closed loop air-to-fuel ratio control system having an oxygen responsive sensor and a feedback circuit is disclosed. The sensor is disposed in an engine exhaust passage to produce a voltage indicative of the oxygen concentration in the exhaust gas. This voltage is integrated in the feedback circuit to cause the mixture air-to-fuel ratio to be corrected in response thereto. The integration is controlled by the integration controller to shift the mixture air-to-fuel ratio to the one other than the stoichiometric ratio. This integration controller can be made responsive to specific engine operating conditions such as throttle valve movement.

Method and system for controlling the mixture air-to-fuel ratio

An air-to-fuel ratio feedback control system which normally functions to correct the air-to-fuel ratio of a mixture supplied to an internal combustion engine to a predetermined air-to-fuel ratio in accordance with an output signal of an air-to-fuel ratio detector disposed in an exhaust passage. The system detects an inoperable period of the air-to-fuel ratio detector due to a low engine temperature and stops the feedback correction of the air-to-fuel ratio to prevent erroneous correction. Furthermore, during the full load operation and idling operation the system holds the feedback correction of the air-to-fuel ratio respectively at a little smaller and larger than the stoichiometric ratio irrespective of the output of the air-to-fuel ratio detector and enables to easily return to substantially the stoichiometric one when the engine operating condition returns to normal operation.

Air-to-fuel ratio feedback control system

A closed loop air-to-fuel ratio control system having an oxygen responsive sensor and a feedback circuit is disclosed. The sensor is disposed in an exhaust passage to produce a voltage indicative of the oxygen concentration in the exhaust gas. This voltage is integrated in the feedback circuit to cause the mixture air-to-fuel ratio to be corrected in response thereto. During specific engine conditions such as engine idling and low temperature of the exhaust gas, the integration is stopped to thereby switch off the closed loop to an open loop. The engine, on this occasion, can be supplied with the air-fuel mixture of an arbitrary ratio irrespective of the oxygen concentration in the exhaust gas, resulting in the optimum air-to-fuel control well-matched to the engine conditions.

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Kariya, Japan

Hideaki Norimatsu