Temperature sensor

Abstract

The invention provides a temperature sensor, which is capable of mitigating stress on the electrode wire and sheath-core wire of the temperature sensing element, wherein the temperature sensor includes a temperature sensing element, a sheath component, a inner burrel and a outer burrel; the temperature sensing element includes a temperature sensing portion and a pair of element electrode wires extending from the temperature sensing portion; the sheath component includes a sheath-core wire connected to the element electrode wire through a connecting portion and a sheath outer pipe packing the sheath-core wire in insulation material; the inner burrel is in metal, which is in a shape of a burrel with bottom, accommodating at least a temperature sensing element and a connection portion as the bottom of the front end, extending in the direction of the element electrode wire and the sheath-core wire; the outer burrel is in metal, which is in a shape of burrel with an opening terminal which is closer to the front end side comparing with the connecting portion and covers the inner burrel in the area of bottom portion of the inner burrel when viewing from the direction perpendicular to the axis of the inner burrel; and the outer burrel disconnects with the inner burrel at a position closer to the front end side comparing with the connecting portion.

Description

technical field [0001] The invention relates to a temperature sensor with temperature sensing elements such as a thermistor element and a Pt resistance element. Background technique [0002] As a temperature sensor for detecting the temperature of exhaust gas of an automobile or the like, a temperature sensor using a resistance temperature change of a thermistor, a Pt resistor, or the like is known (see Patent Documents 1 and 2). [0003] Figure 6 Indicates the general configuration of this type of temperature sensor. Such as Figure 6 As shown in (a), the temperature sensor 500 is constructed by welding the thermistor element 502 and the sheath member 506 and housing them in a metal tube 512 , and filling the gaps in the metal tube 512 with an adhesive 514 such as alumina. [0004] Although the thermistor element 502 is composed of a thermistor sintered body 503 and an element electrode wire 504, since the element electrode wire 504 is an expensive Pt-Rh wire or the like,...

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Problems solved by technology

Moreover, since the shear stress is applied to the joint portion 510 every time the cooling and heating cycle is repeated, the strength of the joint portion 510 may be lowered, and disconnection may occur.

[0009] In addition, the sensor described in Patent Document 1 has a structure in which a thermistor is accommodated in a double-layered tube composed of the inner tube 4 and the metal tube 5 , but since the inner tube 4 and the metal tube 5 are fixed by the TIG welding part 15 at the front end, so the entire barrel is still contracted and the thermistor is squeezed to the rear side

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