Abstract: A gas sensor includes a sensor element having electrode pads, metal terminal members connected to the respective electrode pads, separators, and lead wires connected to the rear ends of the metal terminal members. Each metal terminal member has a forward locking portion and a rear locking portion provided at the forward and rear ends, respectively. The separator is composed of a forward separator and a rear separator connected to each other. The forward separator includes a first locking portion having a rearward-facing surface, and the rear separator includes a second locking portion having a forward-facing surface. The metal terminal member is held between the forward separator and the rear separator in a state in which the forward locking portion is in locking engagement with the rearward-facing surface and the rear locking portion is in locking engagement with the forward-facing surface.

Abstract: A gas sensor includes a sensing element that includes an electrode pad, a metal terminal, and a separator. The metal terminal includes a lead-wire-connecting portion, a main body, a protruding piece that protrudes from a front-end side, and an elastic portion connected to an end of the protruding piece and to the electrode pad. An area S1 of a first opposed surface of a primary surface facing an insertion hole of the separator is larger than an area S2 of a second opposed surface of a secondary surface facing the insertion hole, and a part of the second opposed surface contacts an inner circumferential surface of the separator forming the insertion hole, and the first opposed surface is separated from the inner circumferential surface, where surfaces of the main body and the protruding piece that are located opposite the elastic portion are the primary surface and the secondary surface.

Abstract: An insulating separator of a gas sensor is formed to be dividable into a forward separator having a terminal disposition hole, and a rear separator having four terminal disposition holes. The insulating separator has a ventilation path formed between the forward separator and the rear separator. As a result, moisture and the like which enter the insulating separator from a forward side of the forward separator through the terminal disposition hole can be discharged outward of the insulating separator through the ventilation path. As a result, corrosion of metal terminals caused by entry of moisture can be reduced, whereby transmission of a sensor signal and application of current or voltage through the metal terminals can be appropriately implemented.

Abstract: A gas sensor includes a sensor element, metal terminals, a tubular separator that holds 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 includes a gas sensor element having a detection portion, a metallic shell holding the gas sensor element, and a tubular body made of metal, which is welded in a state of being externally fitted to a front side or a rear side of the metallic shell. In the present invention, the tubular body is tightly fitted to a tapered portion that is provided at an outer surface of the metallic shell and is radially narrowed toward the tubular body. The tubular body is welded at the tapered portion.

Abstract: A gas sensor is provided with a metal shell protecting member formed of a material superior in heat resistance to a metal shell, whereby a high-temperature measurement target (exhaust gas) is prevented from being in direct contact with a region, of a protector internal region of the metal shell, on the front side relative to a protector opposing surface. That is, in the gas sensor, it is possible to suppress corrosion, due to high temperature, of a region, of the protector internal region of the metal shell, on the front side relative to the protector opposing surface (an inner surface and a front end surface of a protector fixing portion), while the metal shell is formed of a material (SUS430) that can be subjected to working (crimping or the like) accompanied with deformation. Therefore, heat resistance of the entire sensor can be improved.

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: 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 gas sensor includes a sensor element having an electrode pad and a metal terminal member including a forward metal terminal member connected to the electrode pad, and a rear metal terminal member connected to the forward metal terminal member and a lead wire. The rear metal terminal member includes a forward end portion, a central portion, and a lead-wire connection portion. The forward end portion and the central portion are integrally connected through a first neck portion smaller in sectional area than the forward end portion and the central portion. The central portion and the lead-wire connection portion are integrally connected through a second neck portion smaller in sectional area than the central portion and the lead-wire connection portion. The first neck portion is greater in moment of inertia of area than the second neck 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 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: A sensor includes a detector element, a connection terminal, and a separator. The contacting portion is in contact with a conductive member so as to overlap the conductive member in a thickness direction, which is a direction of thickness of the detector element between the principal surfaces. The separator includes an element accommodation space that accommodates a portion of an element contact portion and an element back portion, and a partition wall that separates the element accommodation space from a terminal accommodation space that accommodates the contacting portion and a portion of the conductive member and that is adjacent to the element accommodation space in the thickness direction. A frame main body is disposed in an element-side region, which is a region on an element-accommodation-space side in the thickness direction in a region obtained by extending the terminal accommodation space toward the front side in the axial direction.

Abstract: A metal terminal of a gas sensor includes a forward terminal member and a rear terminal member. The forward terminal member is made of a material superior in heat resistance to and greater in “0.2% yield strength” than a material of the rear terminal member. The forward terminal member has heat resistance suitable for a portion which comes into contact with a high-temperature detection element and is larger in an elastic deformation region than the rear terminal member, thereby providing good contact with the detection element and thus facilitating maintenance of electrical contact with the detection element. The rear terminal member is unlikely to have springback at a signal-wire connection portion to be connected to a lead wire, thereby facilitating maintenance of electrical connection with the lead wire.

Abstract: A sensor includes: a detection element; a separator including an insertion portion into which a rear side of the detection element is inserted, and a plurality of terminal housing portions that are disposed surrounding a circumference of the insertion portion around an axial direction, and extend in the axial direction; and a connection terminal that is electrically connected to an electrical connection terminal portion to form a current path. The connection terminal includes a frame body portion and an element contact portion. The sensor further includes a first regulation portion that is located at a position closer to the detection element relative to the frame body portion, in a direction in which a first main surface and a second main surface oppose each other, and regulates the movement of the frame body portion in a direction approaching the detection element.

Abstract: A gas sensor includes a gas sensor element that extends in an axial direction and that includes a detector, which detects a specific gas in a mixed gas; a metal shell that surrounds a periphery of the gas sensor element to hold the gas sensor element; a base that is disposed on a rear side of the metal shell and that covers a rear end portion of the gas sensor element, the base being made of a polymer material; and a metal tube that connects the metal shell and the base to each other and that includes a rear portion and a front portion, the rear portion being integrated with the base, the front portion forming an exposed portion that is exposed from the base. A part of the exposed portion of the tube is connected to the metal shell, and the base is disposed apart from the metal shell.

Abstract: A sensor includes a detector element including a detecting portion and an element back portion on which two or more electrical connection terminal portions are formed; two or more connection terminals which each include an oblong frame main body that extends in an axial direction and an element contact portion that is electrically connected to a corresponding one of the electrical connection terminal portions; a separator that accommodates the connection terminals and the element back portion; and a base that surrounds an outer periphery of the separator. The separator includes a partition wall that is made of a resin material and partitions a plurality of accommodation spaces from each other. The accommodation spaces include an element accommodation space that accommodates portions of the element contact portions and the element back portion, and a plurality of terminal accommodation spaces which each accommodate one of the two or more frame main bodies.

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.

Abstract: A gas sensor includes a sensing element that includes an electrode pad, a metal terminal, and a separator. The metal terminal includes a lead-wire-connecting portion, a main body, a protruding piece that protrudes from a front-end side, and an elastic portion connected to an end of the protruding piece and to the electrode pad. An area S1 of a first opposed surface of a primary surface facing an insertion hole of the separator is larger than an area S2 of a second opposed surface of a secondary surface facing the insertion hole, and a part of the second opposed surface contacts an inner circumferential surface of the separator forming the insertion hole, and the first opposed surface is separated from the inner circumferential surface, where surfaces of the main body and the protruding piece that are located opposite the elastic portion are the primary surface and the secondary surface.

Abstract: A gas sensor includes a sensor element having electrode pads, metal terminal members connected to the respective electrode pads, separators, and lead wires connected to the rear ends of the metal terminal members. Each metal terminal member has a forward locking portion and a rear locking portion provided at the forward and rear ends, respectively. The separator is composed of a forward separator and a rear separator connected to each other. The forward separator includes a first locking portion having a rearward-facing surface, and the rear separator includes a second locking portion having a forward-facing surface. The metal terminal member is held between the forward separator and the rear separator in a state in which the forward locking portion is in locking engagement with the rearward-facing surface and the rear locking portion is in locking engagement with the forward-facing surface.

Abstract: A gas sensor includes a protective cover having a resin cylindrical cover portion at a rear end thereof, that can be airtightly attached to an attachment hole, and that can prevent a decrease in quality and a molding defect. A plurality of vertical ribs, which extend substantially parallel to an axis of a cylindrical cover portion, are formed on an outer peripheral surface of the cylindrical cover portion so that protrusions and recesses are provided in a circumferential direction. Due to the presence of the vertical ribs, as compared with an existing cylindrical cover portion that has a smooth outer peripheral surface without the vertical ribs, defects of the outer peripheral surface are not likely to occur in a molding process. Moreover, because slipping is not likely to occur when an operator holds and twists the cylindrical cover portion with his/her fingers, an attachment operation can be smoothly performed.