Abstract: A sensor element of an A/F sensor AS has a solid electrolyte layer, a first electrode arranged on one side of the solid electrolyte layer so as to be exposed to the exhaust gas of an internal combustion engine, and a second electrode arranged on the other side of the solid electrolyte layer so as to face an atmospheric air chamber. The sensor element generates a sensor output according to the oxygen concentration in the exhaust gas. A microcomputer supplies oxygen to the first electrode side from the second electrode side via the solid electrolyte layer by applying a predetermined voltage between the pair of electrodes of the sensor element. Moreover, the microcomputer determines a crack abnormality of the solid electrolyte layer based on electric current between the pair of electrodes which is generated with start of the oxygen supply.

Abstract: A sensor element of an A/F sensor AS has a solid electrolyte layer, a first electrode arranged on one side of the solid electrolyte layer so as to be exposed to the exhaust gas of an internal combustion engine, and a second electrode arranged on the other side of the solid electrolyte layer so as to face an atmospheric air chamber. The sensor element generates a sensor output according to the oxygen concentration in the exhaust gas. A microcomputer supplies oxygen to the first electrode side from the second electrode side via the solid electrolyte layer by applying a predetermined voltage between the pair of electrodes and of the sensor element. Moreover, the microcomputer determines a crack abnormality of the solid electrolyte layer based on electric current between the pair of electrodes which is generated with start of the oxygen supply.

Abstract: A shielding part is formed on a detection part in a particulate matter detection element. The detection part has a pair of detection electrodes formed in a comb structure. A shielding layer is made of heat insulating material and formed on the detection part in order to shield a predetermined area having non-uniform electric field intensity. An area having uniform electric field intensity on the detection part is exposed only to exhaust gas as target detection gas when a predetermined voltage is supplied between the detection electrodes in order to detect electric characteristics of the detection part. This structure prevents the area other than the area having the uniform electric field intensity on the detection part from being exposed to the exhaust gas.

Abstract: A shielding part is formed on a detection part in a particulate matter detection element. The detection part has a pair of detection electrodes formed in a comb structure. A shielding layer is made of heat insulating material and formed on the detection part in order to shield a predetermined area having non-uniform electric field intensity. An area having uniform electric field intensity on the detection part is exposed only to exhaust gas as target detection gas when a predetermined voltage is supplied between the detection electrodes in order to detect electric characteristics of the detection part. This structure prevents the area other than the area having the uniform electric field intensity on the detection part from being exposed to the exhaust gas.

Abstract: A proton conductor has a porous sintered body made of tetravalent metallic oxide. Pyrophosphate as tetravalent metallic compound is formed on surfaces and porous walls of the body, and in the inside of each pore of the body. A method produces the proton conductor by immersing the porous sintered body made of tetravalent metallic oxide into liquid solvent containing phosphate, and heating the porous sintered body at 400° C. over 4 hours. A carbon quantity detecting sensor has the proton conductor, a pair of a measuring electrode and a reference electrode, and an electric power source for supplying a predetermined current or voltage to the electrode pair composed of the measuring and reference electrodes. The measuring electrode is formed on one surface of the proton conductor to face the measuring gas. The reference electrode is formed on the other surface of the proton conductor to be apart from the measuring gas.

Abstract: When a learning condition is satisfied, control device performs a feedback control. In the feedback control, a metering valve control value is progressively increased to progressively increase a degree of opening of an inlet metering valve, and a pressure of a common rail is kept constant. When the amount of change in a pressure-reducing valve control value becomes equal to or less than a predetermined value, a current metering valve control value, which is currently supplied to the inlet metering valve, is obtained as a maximum discharge rate control value. Also, an intake initiation control value, at which a high pressure pump begins intake of fuel, is obtained. Then, based on these values, a pump characteristic is obtained. Thereafter, the control device obtains the metering valve control value based on a computed degree of opening of the inlet metering valve and the pump characteristic.

Abstract: When a learning condition is satisfied, control device performs a feedback control. In the feedback control, a metering valve control value is progressively increased to progressively increase a degree of opening of an inlet metering valve, and a pressure of a common rail is kept constant. When the amount of change in a pressure-reducing valve control value becomes equal to or less than a predetermined value, a current metering valve control value, which is currently supplied to the inlet metering valve, is obtained as a maximum discharge rate control value. Also, an intake initiation control value, at which a high pressure pump begins intake of fuel, is obtained. Then, based on these values, a pump characteristic is obtained. Thereafter, the control device obtains the metering valve control value based on a computed degree of opening of the inlet metering valve and the pump characteristic.

Abstract: A gas sensor using oxygen-ion-conductive solid electrolyte layers measures a concentration of a constituent gas such as NOx in a gas mixture such as an exhaust gas mixture of an internal combustion engine. The gas sensor includes a pair of oxygen pumping cells and a sensor cell. Before the constituent gas concentration is measured by the sensor cell, oxygen gas contained in the gas mixture has to be purged because the oxygen gas adversely affects the measurement of the constituent gas concentration. Two pumping cells disposed to face a chamber, into which the gas mixture is introduced, pump out the oxygen gas contained in the gas mixture so that the oxygen concentration is reduced substantially zero. Then, the gas mixture is diffused to the sensor cell where the constituent gas concentration is measured without the adverse influence of the oxygen gas. A marginal ion current which is proportional to the constituent gas concentration is measured by the sensor cell with a high accuracy and sensitivity.

Abstract: It is the primary object of the present invention to provide a catalyst converter which can hold a sufficient amount of catalyst to raise the temperature thereof to the catalyst activation temperature in a short time without enlarging the metal carrier itself. The metal carrier 1 is arranged in the course of an exhaust manifold 3 of an engine 2 and is composed of an alternating winding of a flat sheet 7 and a corrugated sheet 8, wherein slit parts 9 are formed in the flat sheet 7 and the corrugated sheet 8 of the metal carrier 1 in an end portion thereof, on the side the engine 2.