| 摘要 |
PROBLEM TO BE SOLVED: To ensure the joining strength of a press-fitting part capable of preventing coming-off of a heat generating member and entrance of combustion gas, in a glow plug formed that the heat generating member to generate heat through energization is fitted in a housing and fixed therein. SOLUTION: In the glow plug 1, a columnar heat generating member 3 is press-fitted in an inner hole 22 of a housing 2. By regulating an interference A of the pressed-fitting part, a length B in a press-fitting direction of a pressure- fitting part, and an outside diameter C of the heat generating member to a given relation, the press-fitting part is formed that a tensile strength when the heat generating member 3 and a housing 2 are pulled by each other along a press-fitting direction is set to 1 kN or more and airtightness of the press- fitting part is set to a level that when a pressure of 10 Mpa is applied on the press-fitting part from the heat generating member 3 side, leakage from the outside of the press-fitting part to the internal part of the housing 2 is substantially prevented from occurring.
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