| 摘要 |
A thin-walled closed metal sleeve in which a heating wire is placed is attached in a socket which is formed with a bore with a carefully smoothly finished inner surface free from grooves or ridges and accurately dimensioned to a predetermined diameter; the outer diameter of the glow plug sleeve is formed to be just slightly larger and the sleeve is then press-fitted, after having been axially aligned with the bore by axially pressing it into the bore; preferably, the end portion of the bore through which the sleeve is inserted is slightly chamfered or funnel-shaped. The manufacturing step of dimensioning and finishing the bore is preferably carried out by ball calibration, that is, by pressing a hardened steel ball therethrough. |
