MANUFACTURING METHOD OF SPARK PLUG

PROBLEM TO BE SOLVED: To provide a technology for suppressing reduction in precision of a spark discharge gap of a spark plug.SOLUTION: The spark plug comprises: a center electrode extending in an axial direction; a main fitting that is provided in an outer periphery of the center electrode; and a rod-like ground electrode of which the proximal end is joined to the main fitting and the distal end is bent at an axial line side. A manufacturing method of the spark plug includes a bending step of bending a non-bent ground electrode that is the non-bent ground electrode, by pressing it to a predetermined curved surface that a flexure spacer includes. The flexure spacer can be divided into two or more members including: a first member including a fitting part for fitting the flexure spacer to a fixture; and a second member including the predetermined curved surface in contact with the non-bent ground electrode.SELECTED DRAWING: Figure 2 【課題】スパークプラグの火花放電間隙の精度の低下を抑制する技術を提供する。【解決手段】軸線方向に伸びる中心電極と、中心電極の外周に設けられた主体金具と、棒状の接地電極であって、基端が主体金具に接合されると共に、先端が軸線側に屈曲された接地電極と、を備えるスパークプラグの製造方法であって、未屈曲の前記接地電極である未屈曲接地電極を、曲げスペーサが有する所定の曲面に押しつけることにより屈曲させる屈曲工程を備え、曲げスペ−サは、曲げスペーサを固定治具に取付ける取付け部を含む第１の部材と、未屈曲接地電極と接触する所定の曲面を含む第２の部材と、を含む２以上の部材に分割可能に構成されている。【選択図】図２