Ngk Spark Plug Company, Limited

Niterra Co., Ltd.

Shunya Mihara

Takehiro Oba

Shogo Nagata

Kenji Masuda

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.

Gas sensor and method for manufacturing the same

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.

Gas sensor

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.

Metal terminal for gas sensor, gas sensor and method for manufacturing gas sensor

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.

Gas sensor and method of manufacturing the same

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 Sof a first opposed surface of a primary surface facing an insertion hole of the separator is larger than an area Sof 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.

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.

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.

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.

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Komaki, Japan

Shunya Mihara