| 摘要 |
Provided is a glow plug that can be attached with only one type of housing without preparing a plurality of types of housings for a plurality of types of internal-combustion engines each having the different taper angle of the taper seat surface of an attachment hole and can be used as a common part. The main metal part (2) of a glow plug (1) has an end portion (20) that has the outside surface diameter expanding toward the rear end side in the axial line direction and can be abutted to a seat surface (55) formed in an internal combustion engine (50) by attaching the glow plug (1) into an attachment hole (51) provided in the internal combustion engine (50). When viewed in a cross section taken along an axial line (C1), the outside surface of the end portion (20) has a plurality of steps, including a first abutment surface (21), a second abutment surface (22), and a third abutment surface (23), in which the angles of virtual lines connecting, with a straight line, inflection points provided on both ends of the end portion (20) are different from each other on a per virtual line basis. The first abutment surface (21), the second abutment surface (22), and the third abutment surface (23) are curved surfaces expanding outward. |
