Gas sensor

Abstract

The invention provides a gas sensor capable of restricting reduction of contact pressure of a terminal metal component relative to an electrode bonding pad of a sensor element and restricting instant power failure between the electrode bonding pad of the plate-shaped sensor element and the terminal metal component. The gas sensor comprises the plate-shaped sensor element a rear end side of which is provided with the electrode bonding pad, an insulation component configured to be the rear end side of the sensor element, the terminal metal component maintained on the insulation component, and a lead a pressed side of which is fixed on a crimping terminal part, wherein the terminal metal component is configured to be opposite to the electrode bonding pad and comprises a main body part, a front end part and the crimping terminal part; the front end part is electrically connected with the electrode bonding pad and the crimping terminal part is connected with a rear end of the main body part; and the terminal metal component is provided with an anti-falling part which is a plate shape of extending from the main body part to the sensor element side. A surface of the anti-falling part facing a rear end is arranged near the rear end side relative to a free end of a front end part, and is abutted to a surface of a surface of the insulation component facing a front end.

Description

technical field [0001] The invention relates to a gas sensor including a sensor element for detecting the concentration of a gas to be detected. Background technique [0002] A gas sensor having a sensor element using a solid dielectric is known as a gas sensor that detects the concentration of oxygen or NOx in exhaust gas of an automobile or the like. [0003] As such a gas sensor, a plurality of electrode pads are provided on the rear end side of a plate-shaped sensor element, and an insulating member is arranged so as to surround the radially outer side of the rear end side of the sensor element, and a terminal metal member is held. A gas sensor based on this insulating member (Patent Document 1). The terminal metal member is electrically connected to the electrode pad, and the rear end side of the terminal metal member is crimped and fixedly connected to the lead wire, thereby outputting the sensor output signal from the sensor element to the outside via the lead wire. ...

AI Technical Summary

Problems solved by technology

Furthermore, when the contact point P is separated from the sensor element, the pressure (hereinafter, referred to as contact pressure) under which the protrusion 400p of the terminal metal member 400 presses the electrode pad of the sensor element decreases, thereby increasing the contact resistance and destabilizing the sensor output.

Moreover, if the contact point P is further away from the sensor element, there will be a momentary disconnection (instantaneous power failure) between the electrode pad and the sensor output signal will not be obtained for a moment.

[0010] In addition, the terminal metal member 400 is also closer to the sensor element than the central axis CL ( Figure 14 is fixed at position B, which is on the left side of the central axis CL, although a force to eliminate the moment M also acts at position B, but since position A is farther away from the lead wire 146 in the direction of axis O than position B, at position A The moment at the place is larger, still as a whole, there is a moment M

[0011] In addition, conventionally, there is a technique in which the diameter of the terminal receiving hole of the insulating member is made substantially the same as the diameter of the lead wire 146, and the crimping terminal portion 400c having a larger diameter than the lead wire 146 is engaged with the periphery of the terminal receiving hole. fixed, thereby preventing the terminal metal member 400a from coming off to the rear end side, but in this case, it is easy to damage the covering layer of the lead wire 146, so it is not preferable.

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