Method and device for manufacturing spark plug

A method for manufacturing a spark plug comprising:

• a tubular insulator extending in the direction of an axis;
• a tubular metallic shell provided around the insulator;
• and the insulator and the metallic shell being fixed together by a crimp portion provided at a rear end portion of the metallic shell and bent inward in the radial direction, the method comprising:
• a crimping step of pressing the rear end portion of the metallic shell along the direction of the axis using a tubular shell pressing jig in a state in which the metallic shell having the insulator inserted thereinto is supported by a tubular receiving member,
• wherein the receiving member is made movable in relation to the shell pressing jig in the radial direction of the receiving member at least when the metallic shell is pressed by the shell pressing jig;
• and
• the crimping step includes an eccentricity adjusting step of reducing an eccentricity between a center axis of the shell pressing jig and the axis of the insulator in the radial direction.

A device for manufacturing a spark plug comprising a tubular insulator extending in the direction of an axis;

• a tubular metallic shell provided around the insulator;
• and talc charged between the insulator and the metallic shell, the device comprising:
• a tubular receiving member for supporting the metallic shell;
• and
• a tubular talc pressing jig which is movable along the direction of the axis,
• wherein the talc is pressed by moving the talc pressing jig in a state in which the metallic shell having the insulator inserted thereinto is supported by the receiving member;
• and
• the receiving member is made movable in relation to the talc pressing jig in the radial direction of the receiving member at least when the talc is pressed by the talc pressing jig.

A device for manufacturing a spark plug comprising a tubular insulator extending in the direction of an axis;

• a tubular metallic shell provided around the insulator;
• and the insulator and the metallic shell being fixed together by a crimp portion provided at a rear end portion of the metallic shell and bent inward in the radial direction, the device comprising:
• a tubular receiving member for supporting the metallic shell;
• and
• a tubular shell pressing jig which is movable along the direction of the axis,
• wherein, in a state in which the metallic shell having the insulator inserted thereinto is supported by the receiving member, the shell pressing jig is moved so as to press the rear end portion of the metallic shell to thereby form the crimp portion;
• and
• the receiving member is made movable in relation to the shell pressing jig in the radial direction of the receiving member at least when the metallic shell is pressed by the shell pressing jig.