Denso Corporation

Nippondenso Co., Ltd.

Takehiro Watarai

Kazuhiko Miura

Yoshinobu Hirose

Kenji Kato

Katsuhide Akimoto

Satoshi Hayashi

Yoshinobu Takeuchi

Makoto Ito

Tomoo Kawase

Keigo Mizutani

Hiromi Hiramatsu

Tomoyuki Kanda

Norikazu Kajiyama

Fuminori Nakashima

Tsunetoshi Goto

Kenzi Kato

Shinro Oda

Junji Moriwaki

Katuhide Akimoto

A gas sensor element includes a main body having a solid electrolyte body on which a measurement gas-side electrode and a reference gas-side electrode are provided, a trap layer covering an outer peripheral surface of the main body to trap poisoning substances contained in a measurement gas, and a waterproof protective layer covering an outer peripheral surface of the trap layer. In the protective layer, there is formed at least one measurement gas introduction port for introducing the measurement gas to the measurement gas-side electrode via the trap layer.

Gas sensor element

A gas sensor element has a first cell, a second cell, and a solid electrolyte layer having proton conductivity commonly used by the first cell and the second cell. The first cell has a first cathode and a first anode exposed to the target detection gas containing hydrogen atoms. The second cell has a second anode, a second cathode, and a shield layer with which the second anode is covered. A voltage is supplied to the first and second cells. A gas concentration of the target detection gas is calculated on the basis of a difference between a current of the first cell and a current of the second cell because the current in the first cell is a sum of proton conductivity current and an electron conductivity current. The current in the second cell is an electron conductive current only.

Gas sensor element and method of detecting concentration of target detection gas

A glow plug with combustion pressure sensor is disclosed having a cover and a housing with which a piezoelectric element is hermetically accommodated. A lead wire having flexibility is employed to supply electric power to a heating member. The lead wire, fixedly connected to the heating member, extends through an insertion bore of the cover and is hermetically bonded to an inner circumferential wall of the insertion bore. When the heating member is axially displaced upon receipt of a combustion pressure, the lead wire flexes to absorb the resulting displacement, causing a joint portion between the cover and the lead wire to have no drag against the displacement. This allows the piezoelectric element to detect the combustion pressure with high precision.

Glow plug with combustion pressure sensor

A combustion pressure sensor for detecting a combustion pressure in a combustion chamber of an engine is disclosed as having a housing mounted to an engine head in a gastight structure, a pressure sensor carried on the housing at a base end portion thereof, a transfer member having a pressure-receiving portion exposed to the combustion chamber to be axially slidable in the housing to transfer a combustion pressure from the combustion chamber to the pressure sensor, and a seal member disposed between the pressure-receiving portion of the transfer member and the housing in a gastight sealing structure to block an intrusion of combustion gas from the combustion chamber into the housing. The seal member includes a flexible portion with low rigidity that can stretch and absorb load acting on the pressure sensor when mounting the housing onto an engine cylinder.

Combustion pressure sensor

A combustion pressure sensor for detecting a pressure in the combustion chamber of an internal combustion engine includes a heat releasing member disposed between a housing and a pressure transmitting member at a position forward of a load detecting section and slidable relative to the pressure transmitting member for releasing heat through heat transfer from combustion gas, which has entered an axial hole of the housing from the combustion chamber, to the housing.

A combustion pressure sensor for an internal combustion engine is provided. The sensor includes a sensing element such as a piezoelectric device sensitive to a physical load applied thereto to produce an electric signal indicative thereof and a bendable member. The bendable member is bent upon application of the combustion pressure in the engine to apply the physical load to the sensing element. Specifically, the physical load is applied to the sensing element which arises from the bend deformation of the bendable member, thus eliminating the need for a complete surface-to-surface contact between the sensing element and the bendable member. This results in a decreased unit-to-unit variation in sensitivity of combustion pressure sensors and ensures the stability of output characteristics of the combustion pressure sensor.

Combustion pressure sensor designed to ensure stability of output characteristic and sensitivity

A method of improving an output characteristic of an angular rate sensor including, for example, a fork oscillator and an improved structure of an angular rate sensor are provided. The improvement of the output characteristic is achieved by adjusting a physical structure of the oscillator to minimize unwanted vibrations of the oscillator or noises of a sensor output. The adjustment of the physical structure is achieved by trimming away an edge portion of the oscillator or a supporter for supporting the oscillator on a base.

Angular rate sensor and method of improving output characteristic thereof

A drive circuit supplies a FB feedback signal having a predetermined frequency to drive electrodes to vibrate a vibrator. An angular velocity detecting circuit detects a vibratory movement caused in a direction normal to an oscillating direction of the vibrator based on a sensing signal of angular velocity sensing electrodes, thereby generating an angular velocity signal. A signal input circuit supplies a diagnostic signal having a frequency different from that of the FB signal, which is entered into the vibrator via diagnosing electrodes. A diagnosis circuit generates a breakdown signal based on a signal responsive to the diagnostic signal which is obtained from at least one of the drive electrodes and the angular velocity sensing electrodes.

Angular velocity sensor and diagnosis system for this sensor

Structure of angular rate sensor

A drive circuit supplies a FB (feedback) signal having a predetermined frequency to drive electrodes to vibrate a vibrator. An angular velocity detecting circuit detects a vibratory movement caused in a direction normal to an oscillating direction of the vibrator based on a sensing signal of angular velocity sensing electrodes, thereby generating an angular velocity signal. A signal input circuit supplies a diagnostic signal having a frequency different from that of the FB signal, which is entered into the vibrator via diagnosing electrodes. A diagnosis circuit generates a breakdown signal based on a signal responsive to the diagnostic signal which is obtained from at least one of the drive electrodes and the angular velocity sensing electrodes.

An angular rate sensor is provided which measures the angular rate of motion applied to a moving object and which features the structure minimizing electrical noise of an output. The angular rate sensor includes generally a first tuning fork, a second tuning fork, and a torsion beam. The first tuning fork includes two tines and serves as a drive oscillator and a measuring oscillator. The second tuning fork includes two tines which extend in the same direction as the first and second tines partially surrounding the first tuning fork and which connect at ends thereof with ends of the tines of the first tuning fork through a stem extending substantially perpendicular to the tines of the first and second tuning forks. The torsion beam extends substantially along the center line of the sensor and supports the stem on a base. The width of the torsion beam is smaller than an overall width of the first tuning fork, thereby minimizing leakage of energy of self-excited oscillation from the drive oscillator to the measuring oscillator and achieving effective transmission of vibratory energy to the measuring oscillator which is produced by the Coriolis force resulting from application of angular motion to the sensor.

Structure of angular rate sensor for minimizing output noise

Drive electrodes and sensing electrodes are formed on a front face of a piezoelectric body of a vibrator. A first reference electrode is formed on a rear face. Second reference electrodes are formed on side faces of arm bars of the vibrator at a position corresponding to the sensing electrodes. The second reference electrodes are connected to the first reference electrode formed on said rear face.

Angular velocity sensor, related method for manufacturing the sensor,

An angular velocity detector includes vibrator made of piezoelectric material and having a pair of arms. A pair of driving electrodes are attached to the arms in order to generate vibrations in the arms. A pair of detecting electrodes, which are attached to the arms, detect the vibrations of the arms. Therefore, the pair of driving electrodes can cause the arms to vibrate uniformly and stably, so that a S/N ratio of the angular velocity sensor can be improved.

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Kuwana, Japan

Takehiro Watarai