Toyota Jidosha Kabushiki Kaisha

Toyota Jidosha Kogyo Kabushiki Kaisha

Nippondenso Co., Ltd.

Nippon Soken, Inc.

Toyota Jidosha Kabushiki

Yoshiki Chujo

Toshiyasu Katsuno

Toshio Tanahashi

Nobuaki Kayanuma

Takatoshi Masui

Hironori Bessho

Toshinari Nagai

Yoshihiko Hyodo

Takehisa Yaegashi

Yasushi Sato

Shinichi Sugiyama

Keiji Aoki

Tokuta Inoue

Toshiaki Konomi

Toshihiko Igashira

Satoshi Iguchi

Kenji Katoh

Yutaka Nonomura

Hiroshi Yorita

Makoto Nakae

Masahiro Shibata

Hiroshi Noguchi

Michiyasu Moritsugu

Ichiro Hosotani

Kohichi Hasegawa

Masahiko Miyahara

Hiroaki Nishimura

Hisataka Okado

Masato Sahashi

Yoshihiko Sano

Koji Tsukada

Keichiro Aoki

A process for fabricating an active electrode for an oxygen sensor involves preparing a solution by dissolving an alkoxide of a metal constituting an oxide semiconductor or solid electrolyte in a mixture of a solvent and diethanol amine, adding chloroplatinic acid to said solution to obtain a precipitation, calcining and pulverizing said precipitation to form a micro-composite power of an oxide of said metal and platinum, and forming an electrode on said oxide semiconductor or solid electrolyte using said composite powder.

Process for fabricating electrode of oxygen sensor

An oxygen concentration detecting apparatus having, a pumping cell and a sensing cell, electrodes formed on both surfaces of each of the pumping and sensing cells, a related support structure forming a closed space by being connected with the pumping and sensing cells, an opening communicating between the closed space and the surrounding environment, an electromotive force detector for detecting an electromotive force generated between the electrodes of the sensing cell, a voltage source for applying a voltage between the electrodes of the pumping cell, a current detector for detecting as a signal representing the oxygen concentration a current flowing in the pumping cell when a voltage is applied between the electrodes of the pumping cell, and a controller for controlling the voltage so that the electromotive force is constant at a specified value at which value the above-mentioned current is 70% or less of the limiting current.

Oxygen concentration detecting apparatus

An oxygen concentration sensor of this invention comprises an element and a diffusion hole. The element is exposed to a gas to be measured and has a chamber portion formed together with an oxygen ion conductive solid electrolyte. The diffusion hole is provided for restricting the flow of said gas to be measured into said chamber portion. Furthermore, the relationship 1.ltoreq.S/(L.multidot.V).ltoreq.5 is established with the diffusion hole having a cross sectional area S (mm.sup.2) and a length L (mm) and the chamber portion having a volume V (mm.sup.3). To do so, the oxygen concentration sensor can provide a stable output even if a pressure of the gas to be measured is abruptly changed.

Oxygen concentration sensor

A liquid mixing ratio detecting apparatus is designed so that an oscillation voltage generated by an oscillation unit is applied to one of a differentiating circuit and an integrating circuit, which is constituted by a combination of a capacitor composed of a pair of opposite electrodes for detecting a mixing ratio of a mixed liquid and a resistor, and a mixing ratio detecting unit produces a signal relating to an inclination rate of one of a differential waveform signal and an integration waveform signal, which is generated by one of the differentiating circuit and the integrating circuit, respectively, thereby obtaining a signal representing the mixing ratio of the mixed liquid on the basis of the produced signal relating to the inclination rate of the waveform signal.

Apparatus for detecting a liquid mixing ratio

A device for detecting a pressure in a combustion chamber comprises a combustion pressure sensor arranged in a cylinder head gasket so that a pressure detecting surface of the sensor is disposed substantially in parallel to a surface of a cylinder head or a cylinder block, and a pressure inlet is provided above the pressure detecting surface to introduce the combustion pressure to the pressure detecting surface. Due to the position of the pressure inlet above the pressure detecting surface, the tightening force of cylinder head bolts is not applied to the pressure detecting surface of the sensor, and thus the reliability of the pressure detection is improved.

Device for detecting combustion pressure of an internal combustion engine

A fuel injector comprising a pair of air passages which are joined at the nozzle opening, whereby fuel injected from the fuel supply bore is joined with the airstreams flowing in the air passages. At this time, the fuel is carried by the airstreams and thus flows through the air passages at a high speed, and accordingly, the fuel is caused to impinge against the inner wall of the nozzle opening at a high speed.

Fuel injector for use in an engine

An oxygen sensor having a body formed of a solid electrolyte material on which electrodes are provided, and a diffusion chamber formed on one side of the body. The diffusion chamber is connected to the space in which the gas to be detected exists, i.e., the interior of the intake or exhaust pipe of an internal combustion engine. A plate is mounted on the body in which a pin-hole is formed for controlling the speed of diffusion of oxygen ions so that the concentration of oxygen ions in the diffusion chamber is equal to that in the detection space. A pore of pores is provided in a plate member forming the diffusion chamber, to enable a rapid equalization of the pressures of the detection space and diffusion chamber while maintaining a control of the diffusion of oxygen ions via the pin-hole.

Oxygen sensor

An engine control system having an oxygen density sensor arranged in an intake system at a position downstream of a throttle valve for detecting the amount of air newly introduced into the engine. The sensor is a limit electric current detection type capable of detecting a continuously changing density of the oxygen. An amount of fuel to be injected is calculated in accordance with the output level of the sensor by using mapped data of the output level of the sensor signal. A precise detection of new air is made possible while maintaining the advantages of the known D-J system. An ignition timing also may be calculated by the signal from the oxygen sensor.

Engine control system

A fuel injection system for an internal combustion engine wherein an oxygen sensor for detecting a limit electric current is employed for providing a signal indicating an oxygen partial pressure in the gas introduced into the engine. The sensor detects an amount of air newly introduced into the engine. In addition to a map for calculating a basic fuel injection amount from the oxygen partial pressure, a second map is provided for calculating the basic fuel amount from a parameter such as a degree of opening of the throttle valve. A degree of activation of the oxygen sensor is determined by detecting the impedance of the sensor. When it is determined that the oxygen sensor is not activated, the second map is employed in place of the first map to calculate the basic fuel amount based on the degree of opening of the throttle valve.

Internal combustion engine having electric controlled fuel injection

A control device for an internal combustion engine having an oxygen sensor, and calculation means for calculating a weight of oxygen fed to the internal combustion engine. The oxygen sensor outputs a signal corresponding only to a density of oxygen contained in intake gas fed to the engine. The oxygen sensor has a diffusion layer having pores through which oxygen molecules pass, the pores having a diameter less than or equal to the mean free path of the oxygen molecules contained in the intake gas.

Device for controlling an internal combustion engine

An engine control system having an oxygen density sensor arranged in an intake system at a position downstream of a throttle valve for detecting the amount of air newly introduced into the engine. The sensor is a limit electric current detection type capable of detecting a continuously changing density of oxygen. An amount of fuel to be injected is calculated in accordance with the output level of the sensor by using mapped data of the output level of the sensor signal. The sensitivity of the sensor is detected and multiplied by the output value of the sensor for obtaining a precise oxygen partial pressure. Instead of calculating the basic fuel amount from the output level of the oxygen density sensor, a normal intake pressure sensor with an intake pressure-engine speed map can be employed. In the latter case, the oxygen partial pressure from the oxygen density sensor is used for correcting the calculated basic fuel amount. The sensitivity of the sensor is also corrected.

In a double air-fuel sensor system including two air-fuel ratio sensors upstream and downstream of a catalyst converter provided in an exhaust gas passage, an actual air-fuel ratio is adjusted in accordance with the outputs of the upstream-side air-fuel ratio sensor and the downstream-side air-fuel ratio sensor. The adjustment of the air-fuel ratio by the downstream-side air-fuel ratio sensor is stopped when the engine is in a predetermined state.

Double air-fuel ratio sensor system having improved response

In a double air-fuel ratio sensor system including two air-fuel ratio sensors upstream and downstream of a catalyst converter provided in an exhaust passage, the actual air-fuel ratio is adjusted in accordance with an air-fuel ratio correction amount calculated by using the output of the upstream-side air-fuel ratio sensor and an air-fuel ratio feedback control parameter such as delay time periods, skip amounts, or integration amounts calculated by using the output of the downstream-side air-fuel ratio sensor, and the calculation of the air-fuel ratio feedback control parameter is prohibited when the downstream-side air-fuel ratio sensor is in an abnormal state.

Double air-fuel ratio sensor system in internal combustion engine

In a double air-fuel sensor system including two air-fuel ratio sensors upstream and downstream of a catalyst converter provided in an exhaust gas passage, a delay operation is performed upon the output of the downstream-side air-fuel ratio sensor, so that the actual air-fuel ratio is adjusted in accordance with the output of the upstream-side air-fuel ratio sensor and the delayed output of the downstream-side air-fuel ratio sensor.

In a double air-fuel sensor system including two air-fuel ratio sensors upstream and downstream of a catalyst converter provided in an exhaust gas passage, an air-fuel ratio correction amount is gradually changed in accordance with the output of the upstream-side air-fuel ratio sensor, and the actual air-fuel ratio is adjusted in accordance with the air-fuel ratio correction amount. The gradual-change speed of the air-fuel ratio correction amount is changed in accordance with the output of the downstream-side air-fuel ratio sensor.

Growing community of inventors

Mishima, Japan

Yoshiki Chujo