Nissan Motor Company Limited

Hiroshi Takao

Shinji Kimura

Kazuo Matoba

Kenji Ikezawa

Shigeo Ishitani

Hiroyuki Aoki

Satoshi Ambe

Masaaki Uchida

Yoshio Akimune

Kinmochi Togawa

Yoshitaka Hata

Katsuhiro Kishida

Kimmochi Togawa

Yasuhiko Ohsawa

Masazumi Ishikawa

Akira Oyamada

Junichi Takimoto

Keishi Negita

Katsunori Aoki

Koki Sone

Masayuki Tohda

Masaharu Ohshima

The electrically controlled force transmitting apparatus includes a drive member having an electrically conductive surface and a driven member having an electrically conductive surface, which are arranged to be opposed to each other with a small space therebetween, a fibrous member provided in the space between the opposed electrically conductive surfaces of the drive and driven members, and a voltage supply source connected across the electrically conductive surfaces, whereby by applying a voltage across the opposed surfaces, there is induced a shear stress and a force is transmitted from the drive member to the driven member. The space in which the fibrous member is arranged is preferably filled with an electrically insulating fluid medium.

Electrically controlled force transmitting method and electrically

At least a portion of an oxygen sensor element support to which portion an oxygen sensor element directly contacts is constructed of an heat insulating material having very low thermal conductivity, so that the heat release from the oxygen sensor element is minimized.

Method of making an oxygen sensor

A process for forming a thin dense layer from a paste of powder in organic vehicle, comprises applying the paste onto a substrate by a screen printing technique, drying and sintering the applied paste under sintering conditions, and repeating the above procedure at least one more time, so as to yield a thin dense sintered layer which is longer in lifetime and more stable in quality than those obtained by known techniques.

Process for forming a thin dense sintered layer

In an oxygen sensor comprising an oxygen ion conductive solid electrolyte, an electronically conductive reference electrode layer formed on one side of the electrolyte layer, an electronically conductive measurement electrode layer formed on the other side of the electrolyte layer, and a partition layer of an electrochemically inactive material formed on the outer side of the reference electrode layer, at least one of the reference and measurement electrode layers has a plurality of openings through which two layers which put therebetween the one of the electrode layers are united with each other.

Method of producing a flat thin film type oxygen sensor

Flat thin film type oxygen sensor

A method of producing an oxygen sensing element which is essentially an oxygen concentration cell in the form of a lamination of relatively thin layers. The first step of the method is to prepare a lamination of a ceramic shield layer, an inner or reference electrode layer, a solid electrolyte layer and an outer or measurement electrode layer which is formed by sintering metal particles applied to the solid electrolyte layer surface in the form of a paste or slurry and dried. Then an additional measurement electrode layer, preferably not thicker than 1.0 micron, is formed on the outer surface of the sintered measurement electrode layer by a physical vapor deposition technique such as ion plating, sputtering or vacuum evaporation. Preferably this electrode layer is formed by a two-stage vapor deposition process wherein the first stage deposition is terminated before the deposited layer becomes thicker than 0.5 microns. The addition of the vapor-deposited measurement electrode layer improves the responsiveness and durability of the oxygen sensing element.

Method of producing solid electrolyte oxygen-sensing element of

A method of producing a flat solid electrolyte layer of a flat film type oxygen sensor is disclosed. The method comprises in steps, (a) preparing first and second electrolyte pastes each containing stabilizer, the content of stabilizer in the first electrolyte paste being smaller than that in the second electrolyte paste, (b) applying the first electrolyte paste onto an electrode layer and then applying the second electrolyte paste onto the outer face of the first electrolyte paste to form a layered paste heap on the electrode layer, and (c) firing the layered paste heap to form a solid electrolyte layer on the electrode layer. With this production method, the stabilizer is uniformly and homogeneously distributed into the body of the fired electrolyte layer.

Method of producing flat solid electrolyte layer of flat film type

A device comprising an oxygen-sensitive element to be disposed in a combustion gas exhausted from a combustor to detect deviation of actual air/fuel ratio from a stoichiometric ratio. The element is a combination of two oxygen concentration cells each having a solid electrolyte layer, a measurement electrode layer formed on one side of the electrolyte layer, a reference electrode layer formed on the opposite side and covered with a shield layer. Either measurement electrode layers or reference electrode layers of the two cells are connected to each other, and a constant DC voltage is applied to the element to force a current to flow through solid electrolyte layers of both cells to cause migration of oxygen ions therethrough, from the measurement electrode to the reference electrode in one cell and reversely in the other. The device has a circuit to make a comparison between a fixed reference voltage and an output voltage developed between the measurement and reference electrodes of one cell of the element to produce a high-or-low level control signal according to the result of the comparison. The output voltage is independent of the internal resistance of the element and is scarcely affected by the temperature of the element.

Device for producing control signal for feedback control of air/fuel

A device comprising an oxygen-sensitive element to be disposed in combustion gas exhausted from a combustor to detect deviation of actual air/fuel mixing ratio of a mixture supplied to the combustor from a stoichiometric ratio. The element is a combination of two oxygen concentration cells each having a solid electrolyte layer, a measurement electrode layer formed on one side of the electrolyte layer and a reference electrode layer formed on the opposite side and covered with a shield layer. The device includes DC power supply means for forcing a current to flow through the solid electrolyte layer of each cell thereby to cause migration of oxygen ions therethrough, from the measurement electrode to the reference electrode in one cell and reversely in the other cell, and a circuit to make a comparison between first and second output voltages respectively developed by the first and second cells to examine which one of these two output voltages is higher than the other and produce a control signal according to the result of the comparison. The signal-producing function is not influenced by the temperature of the element so that a correct control signal can be produced even when the element is not yet sufficiently heated.

A device having an oxygen sensing probe to be disposed in a combustion gas to detect actual air/fuel ratio values of an air-fuel mixture subjected to combustion. The probe is a combination of two oxygen concentration cells each having a porous solid electrolyte layer such as of zirconia, a porous measurement electrode layer on one side of the solid electrolyte layer and a reference electrode layer on the other side, with a shield layer thereon. Either the shield layers of the two cells or the solid electrolyte layers of the two cells are provided by a single layer which serves also as a substrate of the entire probe. The device includes DC power supply means for forcing a current to flow through the solid electrolyte of each cell thereby to cause oxygen ions to migrate through each solid electrolyte layer, from the reference electrode layer to the measurement electrode layer in one cell and reversely in the other cell. Both air/fuel ratios above a stoichiometric ratio inclusive and air/fuel ratios below the soichiometric ratio inclusive can be detected by this device.

Device for detection of air/fuel ratio from oxygen partial pressure in

A method of detecting numerical values for air/fuel ratio of either a lean air-fuel mixture or a rich mixture supplied to, for example, a combustion engine by means of an oxygen sensor disposed in the exhaust gas. The sensor comprises a porous measurement electrode layer on one side of a porous solid electrolyte layer, e.g., of zirconia and a porous reference electrode layer on the other side with a shield layer thereon, so that the reference electrode layer communicates with the exhaust gas through pores in the sensor. Measurement is accomplished by keeping a DC current flowing between the two electrode layers to establish a reference oxygen partial pressure on the reference electrode side. The intensity of the current is made below a critical value above which an EMF generated by the sensor becomes substantially constant unless the air/fuel ratio changes across the stoichiometric ratio, and the direction of the current flow is chosen depending on whether the air-fuel mixture is a lean one or a rich one.

Method of detecting air/fuel ratio in combustor by detecting oxygen in

An apparatus comprising a probe having an oxygen ion conductive solid electrolyte layer, a potentiometer and a DC power source connected to the probe. The probe comprises a porous and electronically conductive reference electrode layer on one side of the solid electrolyte layer, a similar measurement electrode layer on the other side of the electrolyte layer and a separation layer of an inactive material on the outer side of the reference electrode layer. The separation layer or the solid electrolyte layer, or both, has a porous structure and is formed such that the reference electrode communicates with an exterior atmosphere only through this porous structure, while either the separation layer or the electrolyte layer serves as a substrate of the probe. During measurement, the DC power source keeps a current flowing through the electrolyte layer between the two electrode layers to maintain a reference oxygen partial pressure at the interface between the electrolyte layer and the reference electrode layer.

Apparatus for measurement of oxygen concentration

An oxygen sensor comprises a solid electrolyte having one surface covered with a porous metallic film and the other surface on which a sinter of a metal and an oxide of the metal is disposed. Electromotive force (EMF) is developed between the film and the sinter during its use.

Oxygen sensor with a sintered reference source of oxygen

A first layer of a metal/metal oxide sinter which acts as a reference source of oxygen is affixed on a flat surface of a base member, a second layer of solid electrolyte is affixed on the first layer and a third layer of metal is affixed on the second layer so that upon exposure of the third layer to exhaust gases or the like, an EMF (electromotive force) is developed between the first and third layers.

Oxygen sensor

A high temperature abrasion-resistant material in the form of a sintered mass such as a board consists of NiO and/or CoO, Ni and/or Co, and a solid lubricant such as CaF.sub.2. The concentration of the total oxide in the mass is maximum at the surface and continuously decreases as the depth from the surface increases, but the concentration of the total metal is substantially zero at the surface and continuously increases as the depth increases. The lubricant is uniformly distributed. This material is produced by firstly sintering a powder mixture of the ingredients in a non-oxidizing atmosphere into a mass of a desired shape and subsequently heating the sintered mass in an oxidizing atmosphere.

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Kamakura, Japan

Hiroshi Takao