Temperature sensor

Abstract

The present invention provides a temperature sensor, used for measuring temperature of EGR gas and the like, and capable of further improving thermal response. The temperature sensor comprises a bottom cylindrical metal pipe (2), a heat-sensitive element (4) arranged on an inner bottom face of the metal pipe (2) and provided with a pair of terminal electrodes, and a pair of conductors (5) connected to the terminal electrodes, the bottom of the metal pipe (2) is provided with a through hole (2a), and the heat-sensitive element (4) is configured to block the through hole (2a). Thereby, at least a part of the heat-sensitive element (4) is bared outwards from one end part of the metal pipe (2), and thermal response is improved by directly contacting with an external discharge gas and the like.

Description

technical field [0001] The present invention relates to a temperature sensor suitable for temperature measurement of EGR (Exhaust Gas Recirculation) gas, for example. Background technique [0002] In cars equipped with diesel engines, etc., adopting O 2 An EGR (Exhaust Gas Recirculation: Exhaust Gas Recirculation) system that reduces the emission of nitrogen oxides (NOx) by sending less exhaust gas to the combustion process and lowering the combustion temperature. [0003] In this EGR system, a temperature sensor for detecting the temperature of EGR gas is installed at the suction port of the EGR valve (exhaust gas recirculation control valve), and optimal oxygen content control is performed. [0004] Conventionally, as a temperature sensor for detecting the temperature of EGR gas or the like, for example, Patent Documents 1 and 2 propose a thermistor in which a conical glass-type thermistor is inserted into a metal tube together with a filler such as cement or silicone oil...

AI Technical Summary

Problems solved by technology

[0010] That is, in the techniques described in the conventional patent documents 1 and 2, when a filler such as cement or silicone oil is inserted into the metal pipe, the heat capacity increases, so the thermal responsiveness deteriorates. When having sex, there is a bad condition of discomfort

Furthermore, as in the technology described in Patent Document 3, when a plate-shaped element on which a temperature-sensitive resistance film is formed is bonded to the bottom of the metal tube, although the responsiveness is improved, further speed-up of the thermal responsiveness is required.

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