Title: Spark plug and method for manufacturing the same
Application Number: 200510053137 Application Date: 2005.03.04
Publication Number: 1665087 Publication Date: 2005.09.07
Approval Pub. Date: Granted Pub. Date:
International Classifi-cation: H01T13/39,H01T13/20
Applicant(s) Name: NGK Spark Plug Co. Address:
Inventor(s) Name: Yoshimoto Osamu
Attorney & Agent: gu huimin yang benliang
Abstract:
     The invention provided a spark plug capable of reducing the occurrence of a crack or a chipping of a noble metal chip joined to an electrode to carry out spark discharge, and capable of improving durability. As for the noble metal tips 30, 90 joined to at least either one of the center electrode and a ground electrode which form a spark discharge gap of the spark plug, beveling parts 32, 92 are formed at outer peripheral edges of their opposing faces 31, 91. In the noble metal chips 30, 90 which are generally formed by being cut from an element material which is extended by rolling and formed in a columnar state, because crystal particles constituting this are stretched along the pillar axis direction, they exert a mechanical characteristic superior in tenacity and strength. Although there is the possibility of the occurrence of the crack and the chipping in the columnar axis direction, durability of the noble metal chips 30, 90 is improved because they can be dispersed by applying the beveling working even if an external force is given.
Time: 13
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