Patents by Inventor Takehiro Watarai
Takehiro Watarai has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 10379077Abstract: 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.Type: GrantFiled: November 2, 2015Date of Patent: August 13, 2019Assignee: DENSO CORPORATIONInventors: Makoto Ito, Takehiro Watarai
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Publication number: 20170343505Abstract: 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.Type: ApplicationFiled: November 2, 2015Publication date: November 30, 2017Inventors: Makoto ITO, Takehiro WATARAI
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Patent number: 8715474Abstract: 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.Type: GrantFiled: March 5, 2012Date of Patent: May 6, 2014Assignee: Denso CorporationInventors: Keigo Mizutani, Takehiro Watarai, Norikazu Kajiyama
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Publication number: 20120228154Abstract: 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.Type: ApplicationFiled: March 5, 2012Publication date: September 13, 2012Applicant: DENSO CORPORATIONInventors: Keigo MIZUTANI, Takehiro WATARAI, Norikazu KAJIYAMA
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Publication number: 20120103057Abstract: In a PM detection sensor, a gas introduction hole is formed in a cover unit which surrounds a PM detection element. The gas introduction hole faces a detection part having detection electrodes of a comb structure. A projected part generated when an opening part of the gas introduction hole is projected on the detection part is within an inside area of the detection part. The projected area of the opening part of the gas introduction hole is positioned within the inside area having a uniform electric field intensity between the detection electrodes. The target detection gas is directly introduced through the gas introduction hole to the area having the uniform electric field intensity generated on the detection part. PM contained in the target detection gas is captured and accumulated on the area having the uniform electric field intensity but not on the area having non-uniform electric field intensity.Type: ApplicationFiled: October 27, 2011Publication date: May 3, 2012Applicant: DENSO CORPORATIONInventors: Takehito KIMATA, Takehiro Watarai
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Patent number: 7905209Abstract: 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.Type: GrantFiled: August 26, 2008Date of Patent: March 15, 2011Assignee: Denso CorporationInventors: Tsunetoshi Goto, Takehiro Watarai, Yoshinobu Hirose
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Patent number: 7624620Abstract: 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.Type: GrantFiled: June 20, 2007Date of Patent: December 1, 2009Assignee: Denso CorporationInventors: Yoshinobu Hirose, Takehiro Watarai
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Patent number: 7555932Abstract: 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.Type: GrantFiled: April 20, 2007Date of Patent: July 7, 2009Assignee: Denso CorporationInventors: Yoshinobu Hirose, Takehiro Watarai
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Publication number: 20090126472Abstract: A combustion pressure sensor has a cylindrical housing having a fixing functional member fixed to an engines head, and a sealing functional member disposed on the inner side of the fixing member, a transmission member disposed on the inner side of the sealing member through an opening to face a combustion chamber and to be movable along the axial direction, a detecting unit disposed between the sealing member and the transmission member to detect a combustion pressure in the combustion chamber in response to the movement of the transmission member, and a seal member for shielding the opening from the combustion chamber. The members are connected with each other at a connection area such that extension and contraction in the axial direction in each of the functional members is independent of the other one.Type: ApplicationFiled: November 19, 2008Publication date: May 21, 2009Applicant: DENSO CORPORATIONInventors: Yoshinobu Hirose, Takehiro Watarai
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Publication number: 20090056660Abstract: 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.Type: ApplicationFiled: August 26, 2008Publication date: March 5, 2009Applicant: DENSO CORPORATIONInventors: Tsunetoshi GOTO, Takehiro Watarai, Yoshinobu Hirose
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Publication number: 20080223139Abstract: A combustion pressure sensor for detecting a pressure in the combustion chamber of an internal combustion engine includes a seal member sealing a clearance between a housing and a pressure transmitting member slidably inserted through an axial hole of the housing. The seal member is fixed to the housing at a position forward of a load detecting section disposed between the housing and the pressure transmitting member. The seal member is not fixed to the pressure transmitting member.Type: ApplicationFiled: November 30, 2007Publication date: September 18, 2008Applicant: DENSO CORPORATIONInventors: Yoshinobu Hirose, Takehiro Watarai
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Publication number: 20070289370Abstract: 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.Type: ApplicationFiled: June 20, 2007Publication date: December 20, 2007Applicant: DENSO CORPORATIONInventors: Yoshinobu Hirose, Takehiro Watarai
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Publication number: 20070245806Abstract: 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.Type: ApplicationFiled: April 20, 2007Publication date: October 25, 2007Applicant: DENSO CORPORATIONInventors: Yoshinobu Hirose, Takehiro Watarai
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Patent number: 6973820Abstract: 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.Type: GrantFiled: June 14, 2004Date of Patent: December 13, 2005Assignee: Denso CorporationInventors: Takehiro Watarai, Fuminori Nakashima, Hiromi Hiramatsu
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Publication number: 20040261502Abstract: 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.Type: ApplicationFiled: June 14, 2004Publication date: December 30, 2004Applicant: Denso CorporationInventors: Takehiro Watarai, Fuminori Nakashima, Hiromi Hiramatsu
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Patent number: 6415643Abstract: 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.Type: GrantFiled: March 23, 2001Date of Patent: July 9, 2002Assignee: Denso CorporationInventor: Takehiro Watarai
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Patent number: 6282957Abstract: 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.Type: GrantFiled: October 12, 2000Date of Patent: September 4, 2001Assignee: Denso CorporationInventors: Katsuhide Akimoto, Takehiro Watarai, Kenji Kato, Kazuhiko Miura
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Publication number: 20010010169Abstract: 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.Type: ApplicationFiled: March 23, 2001Publication date: August 2, 2001Applicant: DENSO CorporationInventor: Takehiro Watarai
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Patent number: 6223597Abstract: 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.Type: GrantFiled: January 12, 2000Date of Patent: May 1, 2001Assignee: Denso CorporationInventor: Takehiro Watarai
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Patent number: 6182508Abstract: An angular rate sensor is provided which measures the angular rate of a moving object such as an automotive vehicle. The angular rate sensor includes an installation base and an oscillator. The oscillator is excited to oscillate in a preselected direction perpendicular to an axis of rotation of the moving object and provides a signal indicative thereof. The installation base is used for installation of the sensor on the moving object and has an improved orientation structure for orienting the oscillator relative to the installation base during installation of the oscillator on the installation base so that the oscillator may oscillate in the preselected direction. The angular rate sensor is disposed within a casing through improved vibration isolators for absorbing unwanted vibrations impinging upon an operation of the sensor.Type: GrantFiled: December 17, 1997Date of Patent: February 6, 2001Assignee: Denso CorporationInventors: Yoshinobu Takeuchi, Satoshi Hayashi, Takehiro Watarai, Shinro Oda, Junji Moriwaki, Tomoyuki Kanda, Katuhide Akimoto