Abstract: A plug connector capable of increasing the sealing between a rubber member and an outer circumferential surface of a spark plug insulator for improvement in current leakage resistance. The plug connector includes a conductive part that electrically connects a spark plug and a power supply member for power supply to the spark plug; and a rubber member that covers the conductive part. The spark plug has an insulator and a terminal electrode protruding toward the rear from a rear end of the insulator. The plug connector further includes a ring member arranged on an outer circumference of the rubber member.

Abstract: A plug connector capable of increasing the sealing between a rubber member and an outer circumferential surface of a spark plug insulator for improvement in current leakage resistance. The plug connector includes a conductive part that electrically connects a spark plug and a power supply member for power supply to the spark plug; and a rubber member that covers the conductive part. The spark plug has an insulator and a terminal electrode protruding toward the rear from a rear end of the insulator. The plug connector further includes a ring member arranged on an outer circumference of the rubber member.

Abstract: One object of the invention is to provide a plug cap that more reliably prevents the leakage of current by suppressing the ingress of water from a gap between a terminal body and a rubber member. A plug cap 1 includes an electrical connection portion 5 that electrically connects a spark plug to a plug cord, a terminal body 2 that is provided on the outer periphery of the electrical connection portion 5, and a cylindrical rubber member 3 which is mounted on at least one of one end portion and the other end portion of the terminal body 2 and into which the spark plug or the like is inserted. The terminal body 2 includes a one end-side insertion portion 41 which is formed at one end of the terminal body and into which the spark plug is inserted and the other end-side insertion portion 42 which is formed at the other end of the terminal body and into which the plug cord is inserted.

Abstract: One object of the invention is to provide a plug cap that more reliably prevents the leakage of current by suppressing the ingress of water from a gap between a terminal body and a rubber member. A plug cap 1 includes an electrical connection portion 5 that electrically connects a spark plug to a plug cord, a terminal body 2 that is provided on the outer periphery of the electrical connection portion 5, and a cylindrical rubber member 3 which is mounted on at least one of one end portion and the other end portion of the terminal body 2 and into which the spark plug or the like is inserted. The terminal body 2 includes a one end-side insertion portion 41 which is formed at one end of the terminal body and into which the spark plug is inserted and the other end-side insertion portion 42 which is formed at the other end of the terminal body and into which the plug cord is inserted.

Abstract: A glow plug includes a cylindrical housing having an inward protrusion extending radially inwardly, a threaded portion for screwing the glow plug in an engine plug hole and a sealing portion in a front side of the male threaded portion for airtightly engaging the housing with a given portion of the plug hole, a sheath having a rear sheath end portion airtightly fixed in the housing, a heater disposed in the sheath, a center electrode disposed in the housing and having a front electrode end portion electronically connected with the heater and mechanically connected with the sheath and an outward protrusion protruding radially outwardly, and a combustion pressure sensor having a pressure-sensitive element arranged between a front surface of the inward protrusion and a rear surface of the outward protrusion to generate an electrical signal in response to variations in stress applied thereto.

Abstract: An object of the present invention is to provide an ignition coil which has a structure to make it possible to connect the ignition coil to a spark plug directly and in which an installation space need not be changed largely when the ignition coil is mounted in a cylinder head, and an internal combustion engine ignition system having the ignition coil. In the present invention, a protection metal pipe (31) of an ignition coil (9) is formed so that a rear end side portion of a spark plug (11) in the rear of a rear end surface (23b) of a collar portion (23) in a metal shell (19) can be received in the inside of the protection metal pipe (31) from a front end (31b). The ignition coil (9) has a structure in which the ignition coil (9) is directly connected to the spark plug (11). The protection metal pipe (31) of the ignition coil (9) is formed to serve also as a plughole pipe, so that the outer diameter of the protection metal pipe (31) can be enlarged up to the outer diameter of a conventional plughole pipe.

Abstract: A glow plug comprises a cylindrical housing having an inward protrusion extending radially inwardly, a threaded portion for screwing the glow plug in an engine plug hole and a sealing portion in a front side of the male threaded portion for airtightly engaging the housing with a given portion of the plug hole, a sheath having a rear sheath end portion airtightly fixed in the housing, a heater disposed in the sheath, a center electrode disposed in the housing and having a front electrode end portion electronically connected with the heater and mechanically connected with the sheath and an outward protrusion protruding radially outwardly, and a combustion pressure sensor having a pressure-sensitive element arranged between a front surface of the inward protrusion and a rear surface of the outward protrusion to generate an electrical signal in response to variations in stress applied thereto.

Abstract: A glow plug comprises a plug case, a plug body held in the plug case and a combustion pressure sensor. The plug case has a sealing face formed on an inner surface thereof. The plug body includes a housing having a sealing portion airtightly engaged onto the sealing face of the plug case, a sheath having a rear end portion airtightly fixed in a front end portion of the housing, a heater disposed in the sheath, and a center electrode disposed in the housing and mechanically connected with the housing, the sheath and/or the heater so as to become axially displaced due to variations in combustion pressure. The combustion pressure sensor is arranged between rear end portions of the plug case and the center electrode and has a pressure-sensitive element that converts an axial displacement of the center electrode into an electrical signal for detection of the combustion pressure.

Abstract: An object of the present invention is to provide an ignition coil which has a structure to make it possible to connect the ignition coil to a spark plug directly and in which an installation space need not be changed largely when the ignition coil is mounted in a cylinder head, and an internal combustion engine ignition system having the ignition coil.

Abstract: A plug hole pipe 79 has thread grooves 81 formed on an outer circumferential surface thereof and causes a spark plug 11 to be pressed against a cylinder head 51 when the plug hole pipe is fixedly attached to the cylinder head 51 through screw engagement. The spark plug 11 is configured such that no thread grooves are formed on the outer circumferential surface of a front end portion 25 of a metallic shell 19, and can be vertically inserted into a plug disposition hole 51a formed in the cylinder head 51. By vertically inserting the spark plug 11 into the plug disposition hole 51a while the orientation of a ground electrode 21 is set beforehand in relation to the cylinder head 51, the ground electrode 21 can be oriented in a specific direction.

Abstract: A method of manufacturing a gas sensor, including a substrate electrode layer forming step, and a surface electrode layer forming step. The gas sensor includes first and second processing spaces, an oxygen concentration detection element, an oxygen pumping element, an oxidation catalyst and a combustible gas component concentration detection element.

Abstract: A device and method for measuring combustible-gas concentration and a device and method for measuring hydrocarbon-gas concentration, which exhibit low dependence on oxygen concentration variations as well as low temperature dependence. Paste is applied to the inner surface of a closed-bottom cylindrical solid electrolyte element, thereby forming a layer serving as a reference electrode. Plating with platinum is performed, so as to form a layer serving as a first detection electrode, on the outer surface of the solid electrolyte element only at a portion extending from an end portion of the solid electrolyte element to the vicinity of the interface between a heating resistor and a heating-resistor lead portion, which are formed within a heater element contained in the cylindrical solid electrolyte element. Paste which contains gold powder and 10 parts of indium oxide is applied onto the platinum-plating layer so as to form a layer serving as a second detection electrode, followed by firing.

Abstract: A plug hole pipe 79 has thread grooves 81 formed on an outer circumferential surface thereof and causes a spark plug 11 to be pressed against a cylinder head 51 when the plug hole pipe is fixedly attached to the cylinder head 51 through screw engagement. The spark plug 11 is configured such that no thread grooves are formed on the outer circumferential surface of a front end portion 25 of a metallic shell 19, and can be vertically inserted into a plug disposition hole 51a formed in the cylinder head 51. By vertically inserting the spark plug 11 into the plug disposition hole 51a while the orientation of a ground electrode 21 is set beforehand in relation to the cylinder head 51, the ground electrode 21 can be oriented in a specific direction.

Abstract: A method of manufacturing a gas sensor, including a substrate electrode layer forming step, and a surface electrode layer forming step. The gas sensor includes first and second processing spaces, an oxygen concentration detection element, an oxygen pumping element, an oxidation catalyst and a combustible gas component concentration detection element.

Abstract: A gas sensor which can detect the concentration of a combustible gas component in a measurement gas with high accuracy even when the oxygen concentration of the measurement gas or the element temperature changes and which has an excellent response in detecting the combustible gas component is disclosed. In a gas sensor 1, the oxygen concentration of a measurement gas is adjusted to a predetermined level within a first processing space 9 through operation of a first oxygen pump element 3. The measurement gas having an adjusted oxygen concentration is then introduced into a second processing space 10, where a combustible gas component is burned through the assistance of electrodes 16 and 17 functioning as oxidation catalyst sections. Constant voltage is applied to a combustible gas component concentration detection element 5.

Abstract: A gas sensor includes a first processing chamber 3 into which a gas under measurement is introduced through a first gas passage 2; a second processing chamber 5 into which the gas is introduced from the first processing chamber 3 through a second gas passage 4 and in which combustible gas components burn; a third gas passage 15 for introducing O2 into the second processing chamber 5 under diffusion resistance; oxygen pump element 12 adapted to pump out O2 from or pump into the first processing chamber 3 on the basis of an output from an oxygen-concentration sensor 13, which senses the oxygen concentration of the gas introduced into the second processing chamber 5, to thereby control the oxygen concentration of the gas; and a second oxygen pump including a second inner electrode 10 and a second outer electrode 11 formed on an oxygen-ion conductor 1 in such a manner as to face the interior and exterior, respectively, of the second processing chamber 5, and adapted to pump out O2 which remains unconsumed in burn

Abstract: The gas sensor 1 has the following constituent features: (1) first processing space 9: a measurement gas is introduced thereinto via a first gas passage 11; (2) second processing space 10: a gas contained in the first processing space 9 is introduced thereinto via a second gas passage 13; (3) oxygen concentration detection element 4: adapted to measure the oxygen concentration of a gas contained in the first processing space 9; (4) oxygen pumping element 3: adapted to reduce the oxygen concentration of the measurement gas introduced into the first processing space 9 within a range such that water vapor contained in the measurement gas is not substantially decomposed; (5) oxidation catalyst section 16: adapted to accelerate combustion of a combustible gas component contained in a gas introduced into the second processing space 10; and (6) combustible gas component concentration detection element 5: a constant voltage is applied thereto, and element 5 has an output current which varies according to the amount o

Abstract: A gas sensor 1 including a first processing space 9; a first gas passage 11; a second processing space 10; a second gas passage 13; an oxygen concentration detection element 4; a first oxygen pumping element 3 adapted to reduce the oxygen concentration of exhaust gas introduced into the first processing space 9 within a range such that a water vapor contained in the measurement gas is not substantially decomposed; an oxygen catalyst section 16; and a combustible gas component concentration information generation/output section 5. Also disclosed is a gas sensor system including the above gas sensor and first oxygen pumping operation control means for adjusting the oxygen concentration of the measurement gas introduced into the first processing space within a range such that water vapor contained in the measuring gas is not substantially decomposed.

Abstract: The present invention provides an apparatus for measuring the concentration of a constituent to be detected in exhaust gas, which apparatus is capable of detecting with a high accuracy the concentration of the constituent to be detected in exhaust gas even though oxygen concentration in the exhaust gas varies. In an exhaust gas sensor 1 for use in the measuring apparatus, exhaust gas is introduced into spaces 15, 16 on both sides of an oxygen concentration cell element 4, and the oxidation catalyst activities of first to third electrodes 11 to 13 are adjusted so that there occurs a difference between the space 15 and the space 16 in consumption of the constituent to be detected, which consumption is caused by the oxidation of the constituent. Thus a concentration cell electromotive force is generated in the oxygen concentration cell element 4, and an oxygen pump element 3 pumps oxygen into or out of the space 15 so that the electromotive force is held at an target value EC not more than 10 mV.

Abstract: In accordance with the present invention, there is provided an exhaust gas sensor which comprises an oxygen pump cell made of solid electrolyte having an oxygen ion conductivity, an oxygen sensor cell made of solid electrolyte having an oxygen ion conductivity and disposed in opposition to the pump cell in such a manner as to define therebetween a detection space, and a semiconductor detection element made of oxide semiconductor and disposed in the detection space for detecting a predetermined detected substance in the exhaust gas introduced to the detection space. The concentration of oxygen in the detection space is regulated so as to be included within a predetermined range through control of charge or discharge of oxygen into or from the detection space by means of the oxygen pump cell on the basis of the concentration of oxygen in the exhaust gas, which is detected by the oxygen sensor cell.