Ceramic heater and glow plug

Abstract

There is a demand for further improvement in durability of a ceramic heater mounted in a glow plug or the like, since the ceramic heater is used under severe environments. A ceramic heater (11) is provided with a heat-generating resistance element (13); a first lead section (15) and a second lead section (17); a first electrode extracting section (19) and a second electrode extracting section (21) which are electrically connected to end portions of the lead sections (15, 17), respectively; a ceramic base body (23) wherein the heat-generating resistance element (13), the first lead section (15), the second lead section (17), the first electrode extracting section (19) and the second electrode extracting section (21) are embedded; and a first electrode (25) and a second electrode (27) which are formed on a surface of the ceramic base body (23). In the first electrode extracting section (19), an area (S1) of a portion connected with the first electrode (25) is larger than an area (S2) of a portion connected with the first lead section (15).

Description

technical field [0001] The present invention relates to, for example, heaters for ignition or flame detection of combustion-type vehicle heaters, heaters for ignition of various combustion equipment such as petroleum fan air heaters, heaters for glow plugs, and oxygen sensors. Ceramic heaters used for heaters for sensors, heaters for heating measuring equipment, etc. Background technique [0002] As a ceramic heater used in a glow plug or the like of an automobile engine, for example, a ceramic heater including a ceramic base and a ceramic embedded in the ceramic base to generate resistance heat by energizing electrodes connected to both ends is known. heating stuff. In such a ceramic heater, the ceramic heating element includes: a direction changing portion in a U-shape or the like that extends from a base end portion on one side and changes direction at the front end portion to reach the base end portion on the other side; Each base end portion of the direction changing ...

AI Technical Summary

Problems solved by technology

[0008] However, as described in Patent Document 3, when the electrode extraction portion is formed in a direction perpendicular to the ceramic heating element and the cross-sectional area of ​​the electrode extraction portion is formed larger than that of the ceramic heating element, the cross-sectional area of ​​the electrode extraction portion The larger the area, the smaller its own resistance value, which can make the contact resistance value of the electrode extraction part and the lead part and the contact resistance value of the electrode extraction part and the electrode formed on the surface smaller. However, by increasing the There is a problem that the strength of the ceramic heater decreases due to the volume of the electrode extraction part

In addition, since an expensive noble metal is used for the electrode extraction part, there is a problem that the manufacturing cost of the ceramic heater increases

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