Patents Assigned to Kabushiki Kaisha Riken
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Publication number: 20020009630Abstract: A bipolar current collector separator for a fuel cell composed of a metal plate having flow channels and contact faces that come into contact with electrodes or collectors, wherein a corrosion-resistant layer such as an anodized aluminum layer and a heat-resistant polymer layer is disposed on each of the flow channels.Type: ApplicationFiled: May 29, 2001Publication date: January 24, 2002Applicant: Kabushiki Kaisha RikenInventors: Yunzhi Gao, Akira Kunimoto
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Patent number: 6319377Abstract: A nitrogen oxide sensor enabled to enhance the measurement concentration of a total of nitrogen oxides by oxidizing or reducing the nitrogen oxides on the surfaces of electrodes in addition to the control of an oxygen concentration by an oxygen pump. An electrode (3a) in a gas chamber (18) constructing an oxygen pumping portion (3) is made of a material (e.g., Pt-3 wt % Rh) having a function to oxidize a nitrogen oxide gas.Type: GrantFiled: November 13, 1998Date of Patent: November 20, 2001Assignee: Kabushiki Kaisha RikenInventors: Masaharu Hasei, Yongtie Yan, Yunzhi Gao, Takashi Ono, Akira Kunimoto
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Patent number: 6303011Abstract: A nitrogen oxide sensor includes a solid electrolytic substrate exhibiting oxygen ion conductivity, a noble-metal reference electrode, which is active only to oxygen, formed on one side of the solid electrolytic substrate, and a sensing electrode, which is active to NOx and oxygen, formed on the opposite side of the solid electrolytic substrate. A potential difference across the sensing electrode and the reference electrode is output as a signal indicative of NOx concentration. Nitrogen oxides in a gas to be examined or measured gas are converted to NO2 and to peroxides of nitrogen such as N2O5 and NO3, after which the nitrogen oxides in the gas to be examined or measured gas are sensed by the sensing electrode as the peroxides of nitrogen such as N2O5 and NO3 or as a mixed gas of NO2 and the peroxides of nitrogen.Type: GrantFiled: June 18, 1998Date of Patent: October 16, 2001Assignee: Kabushiki Kaisha RikenInventors: Yunzhi Gao, Yukio Nakanouchi, Akira Kunimoto, Masaharu Hasei, Yongtie Yan, Takashi Ono
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Patent number: 6290828Abstract: A rush current to an oxygen sensor is restricted to very small to secure the high reliability of oxygen sensor. A non-inverting input of an amplifier 30 is grounded. A resistor 31 is connected between an inverting input and an output of said amplifier 30. A limited electric current type oxygen sensor 34 is connected between said inverting input of said amplifier and a reference power supply 33.Type: GrantFiled: January 7, 1999Date of Patent: September 18, 2001Assignee: Kabushiki Kaisha RikenInventor: Osamu Yaguchi
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Patent number: 6274016Abstract: A nitrogen oxide gas sensor wherein an alloy electrode of platinum and rhodium or a cermet electrode of platinum, rhodium, and zirconia or of a rhodium alloy and zirconia is used as the gas sensing electrode. The electrode of the sensor is suitable for measuring nitrogen oxide such as NO and NO2 in an exhaust gas.Type: GrantFiled: June 24, 1999Date of Patent: August 14, 2001Assignee: Kabushiki Kaisha RikenInventors: Masaharu Hasei, Yongtie Yan, Akira Kunimoto
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Patent number: 6270638Abstract: A main heater consisting of first and second fever areas and auxiliary heater arranged on an insulator substrate to maintain a precise sensing temperature. Grounded first fever area is contiguous with second fever area and grounded auxiliary heater, with the resistance ratio of first fever area and second fever area identical to that of the third resistor and the second resistor in bridge circuit control. Pyro-sensor or limit current type oxygen sensor capable of maintaining a high temperature, for example 400° C., operates within the high temperature maintained by the main heater, and DC—DC converter for isolating a first power supply, which supplies electric power to the heater from second power supply. Leakage current of the insulator substrate will not be generated as the insulator substrate deteriorates, thereby protecting the sensor cell leakage current from the heater.Type: GrantFiled: May 19, 1998Date of Patent: August 7, 2001Assignee: Kabushiki Kaisha RikenInventor: Masaya Kaneko
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Patent number: 6211496Abstract: The MoSi2 heating element has not been so resistant under the low-temperature heating, because the low-temperature oxidation, which is attributable to the grain boundary oxidation, occurred. In the present invention, long life under the low-temperature heating is attained by the following two structures. (1) The MoSi2 grains have a network structure and are linked three dimensionally. (2) The secondary, silica-bearing oxide or glass phase forms a net-like structure around the MoSi2 grains.Type: GrantFiled: February 19, 1999Date of Patent: April 3, 2001Assignee: Kabushiki Kaisha RikenInventors: Tetsuo Uchiyama, Wan Jiang
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Patent number: 6190039Abstract: A main heater, auxiliary heater and guard heater arranged on an insulator substrate to absorb leakage current, thereby maintaining precise sensing temperature. The main heater is parallel with a bridge circuit containing the auxiliary heater, and the main and auxiliary heater s are typically adjacently arranged with a guard heater there between, electrically interconnected to maintain target temperature of the main heater, regardless of leakage current typically resultant from insulation substrate deterioration.Type: GrantFiled: June 22, 1998Date of Patent: February 20, 2001Assignee: Kabushiki Kaisha RikenInventor: Osamu Yaguchi
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Patent number: 6143165Abstract: The present invention discloses a NOx sensor consisting of at least a pair of electrodes formed in touch with an ion conductive solid electrolyte; wherein the first electrode is composed of oxides of a metal (Cr, Mo or W) selected from 6a Group or a substance containing said oxides and an electric conductive material and the concentration of NOx in the test gas is detected by the change of the electromotive force between the first and second electrodes.Type: GrantFiled: March 16, 1998Date of Patent: November 7, 2000Assignee: Kabushiki Kaisha RikenInventors: Hideyuki Kurosawa, Masaharu Hasei, Noboru Yamazoe, Norio Miura
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Patent number: 6126902Abstract: A stable sensor designed to detect accurately the total NOx concentration under 100 ppm in terms of the NO gas concentration is made up of a first cell and a second cell with a gas diffusion aperture provided between the two cells. The first cell has a partition wall of a substrate of oxygen ion conductor containing zirconia as the main component and permitting a gas to be detected to enter the zirconia substrate; oxygen pumping electrodes are also formed on the first cell substrate which functions to expel oxygen in an atmosphere of the first cell to the outside and to reduce NO.sub.2 of the NOx gas to be detected to NO gas.Type: GrantFiled: June 3, 1997Date of Patent: October 3, 2000Assignee: Kabushiki Kaisha RikenInventors: Akira Kunimoto, Yongtie Yan, Masaharu Hasei, Hideyuki Kurosawa, Yukio Nakanouchi
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Patent number: 6057259Abstract: Nitrogen oxides are removed from an exhaust gas containing nitrogen oxides and oxygen in a proportion larger than its stoichiometric proportion relative to unburned components in the exhaust gas, by (i) disposing an exhaust gas cleaner in a flow path, the exhaust gas cleaner comprising a first catalyst composed of 0.2-20 parts by weight (on a metal basis) of silver or silver oxide supported on a porous inorganic oxide, and a second catalyst composed of 1-50 parts by weight of tungsten and/or vanadium supported on a porous inorganic oxide; (ii) introducing oxygen-containing organic compounds having 2 or more carbon atoms or a fuel containing the oxygen-containing organic compounds into the exhaust gas on the upstream side of the exhaust gas cleaner; and (iii) bringing the exhaust gas into contact with the exhaust gas cleaner at a temperature of 150-650.degree. C., thereby causing a reaction of the nitrogen oxides with the oxygen-containing organic compounds to remove the nitrogen oxides.Type: GrantFiled: May 12, 1995Date of Patent: May 2, 2000Assignees: Kabushiki Kaisha Riken, Agency of Industrial Science TechnologyInventors: Tatsuo Miyadera, Kiyohide Yoshida
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Patent number: 6019881Abstract: The present invention discloses a NO.sub.x sensor consisting at least of a pair of the first and the second electrodes formed in touch with an oxygen conductive solid electrolyte; wherein at least the first elelctrode is composed of oxides of an element selected from 7a Group or 8 Group, especially from Mn, Fe, Co, and Ni or a substance containing said oxides or of hybrid oxides (including the one of oxygen deficiency expressed by ABO.sub.3, AB.sub.2 O.sub.4, A.sub.2 BO.sub.4 and ACBO.sub.4 including 7a Group and 8 Group. A NO.sub.x sensor acording to the present invention has a good sensitivity without being affected by the concentration of CO.sub.2 and detects NO.sub.x concentration in an exhaust gas at a temperature above 600.degree. C.Type: GrantFiled: September 25, 1998Date of Patent: February 1, 2000Assignee: Kabushiki Kaisha RikenInventors: Hideyuki Kurosawa, Masaharu Hasei, Yukio Nakanouchi
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Patent number: 6008479Abstract: In an infrared radiation source containing hot-pressed molybdenum disilicide reinforced with silicon carbide whiskers as the illuminant thereof, terminal portions of the illuminant having a protective dense silica film of 5 to 20 .mu.m in thickness formed on the surface thereof which portions are to be heated at a temperature of 400 to 800.degree. C. are either set to have a current density of at most 12 A/mm.sup.2 or disposed in dry air having a relative humidity at 25.degree. C. of at most 30% (absolute humidity: 0.00588). As a result, the low-temperature oxidation phenomenon that would otherwise be developed in the terminal portions of the illuminant is suppressed. Thus, there can be obtained an infrared radiation source containing an illuminant made of molybdenum disilicide reinforced with silicon carbide whiskers and having a long serviceable life span.Type: GrantFiled: September 26, 1997Date of Patent: December 28, 1999Assignees: Fuji Electric Co., Ltd., Kabushiki Kaisha RikenInventors: Wan Jiang, Kenichi Tsuji, Tetsuo Uchiyama, Mutsumi Nagumo, Satoru Sakaue, Masahiro Uno
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Patent number: 5974871Abstract: An impact and a vibration are applied to a portion of a piston ring on which a belt body is wound, and a vibration is also applied to the belt body. A position where a desired tension can be obtained is obtained by using a master gauge having an outer diameter equal to the inner diameter of a cylinder, and the like. When measuring the tension, a measuring mechanism is moved to this position. The frictional force between the piston ring and the belt body can be considerably decreased, and a closed gap need not be measured every time measurement is performed. Accordingly, the tension of the piston ring can be stably measured at high precision within a short period of time.Type: GrantFiled: March 27, 1998Date of Patent: November 2, 1999Assignee: Kabushiki Kaisha RikenInventors: Hiroyuki Kanda, Takeshi Kuwahara
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Patent number: 5972128Abstract: There is provided a piston ring, which has improved wear resistance and seizure resistance, and which does not abrade the cylinder liner made of flaky-graphite cast iron having a hardness of from HRB 85-95.The composition:C: 3.0-3.5%;Si: 2.2-3.2%;Mn: 0.4-1.0%;P: not more than 0.2%;S: not more than 0.12%;Cr: 0.1-0.3%;V: 0.05-0.2%;Ni: 0.8-1.2%;Mo: 0.5-1.2%;Cu: 0.5-1.2%; andB: 0.05-0.1% are contained in the cast iron.The structure:from 2 to 20% by area of the undissolved carbides and fine graphite are dispersed in a matrix consisting of either tempered martensite or bainite or both.The hardness:HRC 32-45.Type: GrantFiled: October 27, 1997Date of Patent: October 26, 1999Assignee: Kabushiki Kaisha RikenInventor: Tetsuya Miwa
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Patent number: 5965051Abstract: A ceramic heating element includes a heat-generating portion 1 formed of a ceramic composite material with 3 to 40 vol. % of silicon carbide (SiC) whiskers and the balance substantially of molybdenum disilicide (MoSi.sub.2), and electrode portions 2a and 2b provided on both ends of the heat-generating portion 1.Type: GrantFiled: January 22, 1996Date of Patent: October 12, 1999Assignees: Fuji Electric Co., Ltd., Kabushiki Kaisha RikenInventors: Noritomo Hirayama, Nobuhisa Kato, Mutsumi Nagumo, Masahiro Uno, Yohichi Yamashita, Wan Jiang, Tetsuo Uchiyama, Kenichi Tsuji
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Patent number: 5935529Abstract: An exhaust gas cleaner for removing nitrogen oxides by reduction from an exhaust gas containing nitrogen oxides, sulfur oxides, moisture, unburned or partially burned components and oxygen, a content of oxygen in the exhaust gas being larger than a stoichiometric amount required for completely oxidizing or burning the unburned or partially burned components, wherein the exhaust gas cleaner consists essentially of a first catalyst consisting essentially of a first porous inorganic oxide carrying at least one silver component, and at least one transition metal component selected from the group consisting of copper, iron, cobalt, nickel and compounds thereof; and a second catalyst selected from the group consisting of (a) a catalyst consisting essentially of a porous titania, (b) a catalyst consisting essentially of a second porous inorganic oxide carrying a titanium component, (c) a catalyst consisting essentially of the second porous inorganic oxide carrying at least one first component selected from the groupType: GrantFiled: September 6, 1996Date of Patent: August 10, 1999Assignee: Kabushiki Kaisha RikenInventors: Mika Saito, Kiyohide Yoshida
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Patent number: 5904203Abstract: A compact stacked mold is provided by reducing the sand-metal ratio. Cavities (11, 12) are formed on upper and lower sides (13, 14) of a chill plate (10) corresponding to one half of a cam profile, and the upper and lower sides (13, 14) are aligned with parting surfaces of a mold (15).Type: GrantFiled: November 13, 1996Date of Patent: May 18, 1999Assignees: Kabushiki Kaisha Riken, Riken Castec CorporationInventor: Sumitoshi Mai
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Patent number: 5897759Abstract: The present invention discloses a NOx sensor consisting at least of a pair of the first and the second electrodes formed in touch with an ion conductive solid electrolyte; wherein at least the first electrode is selected from hybrid oxides having perovskite structure expressed by MSnO.sub.3 (M is at least an element selected from Mg, Ca, Sr, Ba, Mn, Co, Ni, Zn and Cd, hybrid oxides having pseudo-perovskite structure expressed by M.sub.2 SnO.sub.4 (M is at least an element selected from Mg, Ca, Sr, Ba, Mn, Co, Zn and Cd) or a substance containing said hybrid oxides and the second electrode is selected from a noble metal or a electro conductive ceramics which does not have electro conductivity in the atmosphere of NOx and the concentration of NOx in the test gas is detected by the change of the electromotive force between the first and second electrodes.Type: GrantFiled: September 11, 1996Date of Patent: April 27, 1999Assignee: Kabushiki Kaisha RikenInventors: Hideyuki Kurosawa, Masaharu Hasei, Noboru Yamazoe, Norio Miura
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Patent number: RE37443Abstract: An electric powered bicycle having a dip sensor or switch and/or a gradient sensor or switch. The bicycle has front and rear wheels each rotatably supported by a frame; a chain slung between the wheels and a chainset for transferring manual power to the wheels; an electric motor coupled to one of the wheels for driving the wheel directly; and a power supply capable of supplying electric power to the motor. The dip gradient sensors are associated with a pulse width modulation circuit.Type: GrantFiled: February 18, 1999Date of Patent: November 13, 2001Assignee: Kabushiki Kaisha RikenInventor: Osamu Yaguchi