Abstract: A gas sensor (1) including a sensor element (10); a metallic shell (138); a tubular outer surface member (190) attached directly or indirectly to the metallic shell, constitutes an outer surface of the gas sensor, and extends toward a rear end side in relation to the metallic shell; and a tubular protection member (210, 220) which is detachably fixed to a fixation region C1, C2 of an outer circumference of the outer surface member. The protection member includes a first arc portion (212), a second arc portion (222), and a fixation portion (214,224) brought into contact with and is fixed to the fixation region. When the protection member fixed to the outer circumference of the outer surface member by fixing the fixation portion to the fixation region is viewed in the axial O direction, the first arc portion and the second arc portion cover in total at least 90% of the entire circumference of the outer surface of the outer surface member.

Abstract: A gas sensor including: a sensor element extending in an axial direction; a metal shell surrounding and supporting the sensor element; an exterior tube that is tubular and is mounted to a rear end of the metal shell; a metal terminal including a first end connected to a lead wire and a second end electrically connected to the sensor element; a separator that is tubular and is disposed in the exterior tube and contains the metal terminal and the sensor element; and a holder being in contact with the separator in the axial direction. The holder includes ribs formed in a frontward face or a rearward face of the holder and arranged at predetermined intervals in a circumferential direction. Each of the ribs occupies a region having a length equal to or greater than a thickness of the holder, as viewed in the axial direction.

Abstract: A sensor (1) comprising: a sensor element (10); metal terminals; and a front side separator (90) and a rear side separator (95) to hold the metal terminals, the metal terminals each include a front side metal terminal (30) and a rear side metal terminal (40) respectively held by the front side separator and the rear side separator, a first connection portion (33) is provided on a rear side of the front side metal terminal, a second connection portion (43) is provided on a front side of the rear side metal terminal, and an axis P2 of one of the first and the second connection portion, in all of the plurality of metal terminals, is displaced toward a radially outer side of the sensor element relative to an axis P1 of a counterpart thereof, and the first connection portion and the second connection portion are in contact with each other.

Abstract: A gas sensor includes a gas sensor element for detecting the concentration of a specific gas in a gas under measurement, a tubular housing having an opening, a sealing member closing the opening, and a heat dissipating member having a rear end located at the same position or forward of the rear end of the housing. The heat dissipating member reduces heat transferred from the forward end side of the gas sensor to the sealing member and includes a connection portion connected to the housing, and a main portion extending rearward from the connection portion such that a gap is formed between the main portion and the housing. The main portion has heat dissipating openings for establishing communication between the gap and a space on the outer circumferential side of the heat dissipating member. The heat dissipating openings are formed on the rear end side of the main portion.

Abstract: Disclosed is a manufacturing method of a gas sensor. The gas sensor has a plate-shaped sensor element with at least one pair of electrode pads, a separator disposed around the sensor element, and at least one pair of opposed metal terminals held in an insertion hole of the separator and electrically connected at contact regions thereof to the respective electrode pads. The manufacturing method includes mounting the metal terminals in the insertion hole of the separator with use of a mounting jig. The mounting jig has a flat portion interposed between the contact regions of the metal terminals during the mounting of the metal terminals in the separator so as to prevent contact and entanglement of the opposed metal terminals.

Abstract: A gas sensor (1) including a sensor element (10) and a separator (90) having an element hole (90 h), as viewed from one of a forward-end or a rear-end side in the axial direction. The separator has end surfaces (90 e) located axially farthest toward the one of the forward-end or the rear-end side, recess regions (90 h), (90 r 1) and (90 r 2) recessed from the end surfaces, and regions R1 and R2. First regions R1 are determined by eliminating a region SB occupied by the sensor element from a region SA defined by imaginary short-side lines and the outer edge of the separator. Second regions R2 are determined by eliminating the region SB from a region SC defined by imaginary long-side lines and the outer edge of the separator. S2/S1?0.5 is satisfied, where S1 is the total area of R1 and R2, and S2 is the total area of the recess regions.

Abstract: A gas sensor including a plate-shaped sensor element having an electrode pad on an outer surface of the sensor element on a rear end side thereof, and a metal terminal member electrically connected to the electrode pad. The metal terminal member includes a body portion and an element abutting portion extending from the body portion and bent toward the electrode pad. A portion of the element abutting portion is in contact with the electrode pad in a state in which the element abutting portion is elastically deflected. The element abutting portion has a flat main surface facing the sensor element, and a sloping surface provided on at least one of end portions in a width direction of the metal terminal member. The sloping surface is connected to the main surface and extends toward an opposite side in a thickness direction of the element abutting portion.

Abstract: A gas sensor is configured to inhibit wear of a metal member contacting with a member containing ceramic. The gas sensor comprising: a first member containing ceramic; and a metal member contacting with the first member, wherein a hardness h1 of a contact part of the metal member contacting with the first member is greater than a hardness h2 of a reference part exhibiting a maximum thickness of the metal member.

Abstract: A gas sensor includes a gas sensor element for detecting the concentration of a specific gas in a gas under measurement, a tubular housing having an opening, a sealing member closing the opening, and a heat dissipating member having a rear end located at the same position or forward of the rear end of the housing. The heat dissipating member reduces heat transferred from the forward end side of the gas sensor to the sealing member and includes a connection portion connected to the housing, and a main portion extending rearward from the connection portion such that a gap is formed between the main portion and the housing. The main portion has heat dissipating openings for establishing communication between the gap and a space on the outer circumferential side of the heat dissipating member. The heat dissipating openings are formed on the rear end side of the main portion.

Abstract: A gas sensor includes a sensor element, metal terminals, a tubular separator holding the metal terminals, lead wires connected to rear ends of the metal terminals, and an elastic member that holds the lead wires extending rearward from the separator. Each metal terminal includes a forward end portion electrically connected to an electrode portion, a central portion, and a lead wire connection portion. The forward end portion or the central portion is held by the separator. The central portion and the lead wire connection portion are connected to each other through a neck portion. The rearward-facing rearmost surface of the central portion is engaged with a forward-facing surface of the separator, and the circumferential length of a first connection portion between the central portion and the neck portion is longer than the circumferential length of a second connection portion between the lead wire connection portion and the neck portion.

Abstract: A gas sensor including: a sensor element extending in an axial direction; a metal shell surrounding and supporting the sensor element; an exterior tube that is tubular and is mounted to a rear end of the metal shell; a metal terminal including a first end connected to a lead wire and a second end electrically connected to the sensor element; a separator that is tubular and is disposed in the exterior tube and contains the metal terminal and the sensor element; and a holder being in contact with the separator in the axial direction. The holder includes ribs formed in a frontward face or a rearward face of the holder and arranged at predetermined intervals in a circumferential direction. Each of the ribs occupies a region having a length equal to or greater than a thickness of the holder, as viewed in the axial direction.

Abstract: A sensor (1) comprising: a sensor element (10); metal terminals; and a front side separator (90) and a rear side separator (95) to hold the metal terminals, the metal terminals each include a front side metal terminal (30) and a rear side metal terminal (40) respectively held by the front side separator and the rear side separator, a first connection portion (33) is provided on a rear side of the front side metal terminal, a second connection portion (43) is provided on a front side of the rear side metal terminal, and an axis P2 of one of the first and the second connection portion, in all of the plurality of metal terminals, is displaced toward a radially outer side of the sensor element relative to an axis P1 of a counterpart thereof, and the first connection portion and the second connection portion are in contact with each other.

Abstract: In a circular cross section obtained by cutting a protector along a plane which is orthogonal to an axial direction and passes through gas introduction holes, the gas introduction holes are arranged asymmetrically in the circumferential direction of a circumferential wall of the protector. When the circular cross section is bisected into first and second divisional regions by a straight line which passes through the center of the circular cross section and does not pass through any gas introduction holes, the total opening area of gas introduction holes located in the first divisional region is smaller than the total opening area of gas introduction holes located in the second divisional region.

Abstract: Disclosed is a manufacturing method of a gas sensor. The gas sensor has a plate-shaped sensor element with at least one pair of electrode pads, a separator disposed around the sensor element, and at least one pair of opposed metal terminals held in an insertion hole of the separator and electrically connected at contact regions thereof to the respective electrode pads. The manufacturing method includes mounting the metal terminals in the insertion hole of the separator with use of a mounting jig. The mounting jig has a flat portion interposed between the contact regions of the metal terminals during the mounting of the metal terminals in the separator so as to prevent contact and entanglement of the opposed metal terminals.

Abstract: A gas sensor (1) including a sensor element (10) and a separator (90) having an element hole (90h), as viewed from a particular side which is a forward-end side or a rear-end side. The separator has end surfaces (90e) located farthest in an axial direction toward the particular side, recess regions (90h), (90r1) and (90r2) recessed from the end surfaces, and first regions R1 and second regions R2. First regions R1 are determined by eliminating a region SB occupied by the sensor element from a region SA defined by imaginary short-side lines and the outer edge of the separator. Second regions R2 are determined by eliminating the region SB from a region SC defined by imaginary long-side lines and the outer edge of the separator. A relation of S2/S1?0.5 is satisfied, where S1 is the total area of R1 and R2, and S2 is the total area of the recess regions.

Abstract: A gas sensor includes a sensing element having an electrode pad a metal terminal, and a separator that has insertion holes in which the metal terminal is held. The metal terminal includes a main body and an elastic portion that is integrally connected to the main body and is elastically connected to the electrode pad at a predetermined contact point. The main body includes a front-end-side restricting portion and a rear-end-side restricting portion that restrict the movement of the main body by contacting wall surfaces of the insertion hole when the main body moves in a direction intersecting the direction of an axial line. The contact point is located between the front-end-side restricting portion and the rear-end-side restricting portion in the direction of the axial line. The front-end-side restricting portion and the rear-end-side restricting portion are connected to each other so that a flat board portion is interposed therebetween.

Abstract: Disclosed is a manufacturing method of a gas sensor. The gas sensor has a plate-shaped sensor element with at least one pair of electrode pads, a separator disposed around the sensor element, and at least one pair of opposed metal terminals held in an insertion hole of the separator and electrically connected at contact regions thereof to the respective electrode pads. The manufacturing method includes mounting the metal terminals in the insertion hole of the separator with the use of a mounting jig. The mounting jig has a flat portion interposed between the contact regions of the metal terminals during the mounting of the metal terminals in the separator so as to prevent contact and entanglement of the opposed metal terminals.

Abstract: In a circular cross section of a protector obtained by cutting the protector along a plane which is orthogonal to the axial direction and passes through gas introduction holes, one gas introduction hole and another gas introduction hole having an opening area different from that of the one gas introduction hole are arranged along an imaginary line passing through the center of the circular cross section such that the two gas introduction holes are located on opposite sides with respect to the center of the circular cross section.

Abstract: A metal terminal includes a front-side terminal member and a rear-side terminal member. The front-side terminal member includes a female connection portion, and the rear-side terminal member includes a male connection portion. The female connection portion has an insertion port in which the male connection portion is inserted. The insertion port is formed in a shape that prevents the insertion port and the male connection portion from coming into contact with each other when the male connection portion is inserted therein. The female connection portion includes a terminal contact portion which brings the male connection portion and the female connection portion into contact with each other by pressing the male connection portion toward the female connection portion inside the female connection portion.

Abstract: A gas sensor includes a sensing element having an electrode pad a metal terminal, and a separator that has insertion holes in which the metal terminal is held. The metal terminal includes a main body and an elastic portion that is integrally connected to the main body and is elastically connected to the electrode pad at a predetermined contact point. The main body includes a front-end-side restricting portion and a rear-end-side restricting portion that restrict the movement of the main body by contacting wall surfaces of the insertion hole when the main body moves in a direction intersecting the direction of an axial line. The contact point is located between the front-end-side restricting portion and the rear-end-side restricting portion in the direction of the axial line. The front-end-side restricting portion and the rear-end-side restricting portion are connected to each other so that a flat board portion is interposed therebetween.