摘要:
An air/fuel ratio sensor has an oxygen sensor cell including a primary measuring element in direct contact with a gas such as exhaust gases of an automotive engine, and an oxygen pump cell formed by inner and outer electrodes and a cover of an oxygen ion conductive solid electrolyte which confines the primary measuring element within a gas diffusion control space, and which has a small gas diffusion hole. The primary measuring element is formed with a central opening whose center lies right below the gas diffusion hole, in order to reduce a burden imposed on the oxygen pump cell and prevent overshoot in a sensor response characteristic. The oxygen sensor cell may be composed of the primary measuring element of a transition metal oxide connected with a pair of electrodes for measurement of an electrical resistance of the primary element, or may be composed of an oxygen ion conductive solid electrolyte substrate sandwiched between a reference electrode and the primary measuring element which serves as a measuring electrode.
摘要:
The invention relates to a gas sensor element which utilizes a change in the electric resistance of a porously fired TiO.sub.2 layer. To improve the speed of response of the gas sensor element, and also to strengthen the adhesion of the fired TiO.sub.2 layer to a ceramic substrate, at least one kind of metal oxide which hardly undergoes solid phase reaction with TiO.sub.2 and serves as a sintering suppressing agent, such as Er.sub.2 O.sub.3, Sm.sub.2 O.sub.3 and/or In.sub.2 O.sub.3, is added to TiO.sub.2 in advance of firing. The speed of response is further enhanced by the addition of at least one kind of noble metal such as Pt and/or Rh to TiO.sub.2 together with the sintering suppressing oxide(s).
摘要翻译:本发明涉及一种气体传感器元件,其利用烧结TiO 2层的电阻的变化。 为了提高气体传感器元件的响应速度,并且还增强了烧结的TiO 2层与陶瓷基板的粘附性,至少一种与TiO 2几乎不发生固相反应并用作烧结抑制剂的金属氧化物 ,例如Er 2 O 3,Sm 2 O 3和/或In 2 O 3。 与烧结抑制氧化物一起添加至少一种贵金属如Pt和/或Rh至TiO 2,进一步提高了响应速度。
摘要:
A system and method for controlling an air/fuel mixture for an internal combustion engine are disclosed in which an integration constant used for a calculation of an integration portion included in a feedback correction coefficient (.alpha.) of the air/fuel mixture ratio after a relationship between an actual air/fuel mixture raito and target (stoichiometric) air/fuel mixture ratio has been inverted is set and varied according to an engine driving condition, so that the integration constant meets requirements of a stability during an engine steady driving condition and a favorable responsive characteristic during an engine transient condition. In a preferred embodiement, a fuzzy control is applicable to the calculation of the integration constant.
摘要:
An air-fuel ratio control system for an automotive internal combustion engine provided with a three-way catalytic converter disposed in an exhaust gas passageway of the engine. The air-fuel ratio control system is comprised of an oxygen sensor disposed in the exhaust gas passageway downstream of the catalytic converter. The air-fuel ratio of air-fuel mixture to be supplied to the engine is controlled toward a stoichiometric value to cause the three-way catalytic converter to efficiently work under the action of a control unit including a microcomputer. In the control unit, a control constant is set in accordance with the output voltage of the oxygen sensor, and a cycle signal (pulse signal) is cyclically generated. The control constant is compulsorily minutely vibrated under the action of the cycle signal, thereby obtaining an air-fuel ratio correction coefficient. The amount of fuel to be supplied to the engine is calculated in accordance with the air-fuel ratio correction coefficient and injected from a fuel injector valve.