Denso Corporation

Ishifuku Metal Industry Co., Ltd.

Tanaka Kikinzoku Kogyo K.k.

Yuki Murayama

Ryozo Kayama

Nobuo Abe

Akimitsu Sugiura

Fumiaki Aoki

Kaori Doi

Tomoo Kawase

Koichi Sakairi

Kunihiro Tanaka

Akari Hasegawa

Shoki Shimizu

Manabu Yoshidome

Noriaki Nishio

Yusuke Todo

Yoshinori Doi

Tadakatsu Koyabu

Toshiyuki Tomine

Hiroki Ichikawa

Shunsuke Yokota

Yusuke Kawamoto

Fumiya Nagata

A first cell includes a first electrode in a measurement gas chamber and a second electrode in a reference gas chamber. A second cell includes a third electrode in the measurement gas chamber and a fourth electrode in the reference gas chamber to cause a current therebetween that corresponds to a concentration of a specific gas component in detected gas in the measurement chamber. A controller selectively implements a normal control and a reduction control. The normal control is to apply a lower voltage to the first electrode and the second electrode to remove oxygen from the detected gas. The reduction control is to apply a higher voltage to the first electrode and the second electrode to reduce the third electrode that is oxidized. The controller prohibits implementation of the reduction control on determination that implementation of the reduction control.

Gas sensor control device

Each of SCUs to includes: a voltage switching unit that performs a first voltage switching to increase an oxygen concentration in a gas chamber and a second voltage switching to decrease the oxygen concentration in the gas chamber after the execution of the first voltage switching; an output change calculation unit that calculates an output change parameter indicating a change in output of the sensor cell according to the voltage switching; a concentration difference calculation unit that calculates a concentration difference parameter indicating a concentration difference in the oxygen concentration or in the concentration of the specific gas in the detection target gas between before the first voltage switching and after the second voltage switching; and a deterioration determination unit that determines a deterioration state of the sensor cell based on the output change parameter and the concentration difference parameter.

A control device performs deterioration diagnosis of a gas sensor including a pump cell and a sensor cell. The control device includes a control unit, a determination value acquisition unit, a diagnosis unit, and a correction unit. The control unit temporarily reduces the oxygen removal capability of the pump cell. The determination value acquisition unit acquires an output ratio of the sensor cell based on an output value of the sensor cell in a state where the oxygen removal capability of the pump cell is temporarily reduced. The diagnosis unit performs deterioration diagnosis of the gas sensor by comparing the output ratio with a determination threshold. The correction unit sets a correction coefficient based on an atmospheric pressure and an oxygen concentration, and also corrects the output ratio using the correction coefficient.

It is to determine whether a temperature rise condition of a first cell or a second cell is satisfied based on whether a first parameter has exceeded a predetermined first threshold or a second parameter has exceeded a predetermined second threshold. After satisfaction of the temperature rise condition, it is to determine that an exhaust gas sensor is in an active state upon determination that a corresponding time condition is satisfied.

Control apparatus

In a gas sensor, a pump cell adjusts a concentration of oxygen in a gas chamber based of a pump cell supply voltage. A sensor cell detects a concentration of a specific gas in a detection target gas after the pump cell has adjusted the concentration of oxygen. In a sensor control unit, a voltage switching part adjusts the pump cell supply voltage to be supplied to the pump cell. A pump cell output control part adjusts a variation range of a pump cell output current of the pump cell before and after a voltage switching process of the pump cell supply voltage to be within a predetermined variation range. A deteriorated state detection part detects a deteriorated state ratio of the sensor cell based on variation of an output current of the sensor cell due to the voltage switching process performed by the voltage switching part.

A microcomputer includes a voltage application unit that selectively applies a normal voltage and a removal voltage higher than the normal voltage to a first cell of the exhaust gas sensor. The first cell is configured to remove, based on the removal voltage, oxygen in an exhaust gas from an internal combustion engine. The microcomputer includes an element temperature measurement unit that measures an element temperature parameter indicative of a temperature of the first cell. The microcomputer includes a termination determination unit that determines, based on the element temperature parameter, a termination time of terminating the application of the removal voltage to the first cell by the voltage application unit.

A control apparatus is provided for controlling an exhaust gas sensor. The exhaust gas sensor includes a first cell, a second cell configured to output electric current depending on the concentration of a measurement target component in exhaust gas from which oxygen has been removed by the first cell, and a heater configured to heat the first and second cells. The control apparatus includes a heater controlling unit, a current detecting unit configured to detect the electric current outputted from the second cell, and a deterioration determining unit. The deterioration determining unit causes the heater controlling unit to change output of the heater and thereby changes the temperature of the first cell. During the change in the output of the heater, the deterioration determining unit determines, based on an amount of change in the electric current detected by the current detecting unit, whether or not the second cell is deteriorated.

Control apparatus for exhaust gas sensor

An ignition apparatus for an internal combustion engine provided with an ignition coil and a spark plug. An ECU enables operation of a plurality of continuous discharges in the spark plug and also detects a flow speed of a combustible air/fuel mixture. In a first discharge, a supply of a primary current terminates the first discharge, with energy remaining in the ignition coil, from an initiation of the ignition to an initiation of the spark plug, when the detected flow speed exceeds a predetermined first threshold. Thereafter, a second discharge is performed by shutting off the primary current.

Ignition apparatus for internal combustion engines

An ignition control system is applied to an internal combustion engine having an ignition coil, a switching element and a measurement detection part which detects at least one of a primary and a secondary voltages and a secondary current. The ignition coil has a primary coil and a secondary coil. The switching element performs conduction and interruption the primary current to the primary coil. The ignition control system has a primary current control unit generating a spark discharge at the ignition plug by passing the primary current through the primary coil, and perform interruption of the primary current, and a discharge short-circuiting determination part determining a generation of discharge short-circuiting based on a measured value. The primary current control unit generates the spark discharge again when discharge short-circuiting occurs.

Ignition control system

A spark plug has a center electrode and an earth electrode. The center electrode is faced to the earth electrode so that a spark discharging gap is formed between the center electrode and the earth electrode. An electrode chip is formed on at least one of the center electrode and the earth electrode. The electrode chip has a composition containing 40 to 60 mol % of aluminum and iridium as a remainder thereof. In the composition of the electrode chip, it is possible to replace part of the iridium with 1 to 20 mol % of at least one metal selected from nickel, iron, cobalt, platinum and rhodium.

Spark plug for internal combustion engine of motor vehicles

A spark plug for use in an internal combustion engine has a center electrode, an earth electrode, and an electrode chip formed on at least one of the center electrode and the earth electrode. A spark discharge gap is formed between the center electrode and the earth electrode. The electrode chip has a base section, a chromium rich layer formed on at least a part of the base section, and a diffusion layer formed between the base section and the chromium rich layer. The base section contains chromium within a range of 5 to 45 mass %, an element X within a range of 0.5 to 25 mass %, and a remainder composed of tungsten and unavoidable impurity. The chromium rich layer is larger in content of chromium than the base section. The element X contained in the base section is comprised of at least one of molybdenum, silicon, aluminum and lead.

Spark plug for internal combustion engine

In a spark plug, a center electrode includes a base member and a discharge chip that has a higher melting point than the base member. The base member and the discharge chip are joined to each other by both a weld and a diffusion layer. The weld is formed, by fusion welding, along an outer periphery of an interface between the base member and the discharge chip into an annular shape. The weld is made up of those parts of the base member and the discharge chip which are molten and mixed together during the fusion welding and solidified after the fusion welding. The diffusion layer is formed radially inside the annular weld. The diffusion layer is made up of those parts of the base member and the discharge chip which are diffused into each other across the interface between the base member and the discharge chip.

Spark plug for internal combustion engine and method of manufacturing the same

A spark plug for an internal-combustion engine. The spark plug includes a central electrode, an insulator that holds the central electrode inside, a housing that holds the insulator inside, a ground electrode that forms a spark gap with the central electrode. The ground electrode includes a ground base member connected to the housing, and a ground protrusion protruding from a confronting face of the ground base member confronting the central electrode. The ground protrusion has a diameter of 0.9 to 1.4 mm. The spark plug is configured to satisfy &#x3b8;&#x2267;&#x2212;53R+49, where R [mm] is a curvature radius of a base member corner and &#x3b8;[degrees] is an angle formed by a shortest connecting line between the base member corner and a protrusion corner and a plane perpendicular to an axial direction of the ground protrusion.

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Kariya, Japan

Yuki Murayama