| 发明名称 | Spark plug | ||
| 摘要 | It is an object of the present invention to provide a spark plug having a ground electrode joined securely by electric resistance welding. The spark plug includes a cylindrical metal shell and a ground electrode joined by electric resistance welding to an end portion of the metal shell. The metal shell has a high hardness region formed with a Vickers hardness of 3×102 to 5×102 Hv in the end portion thereof in such a manner that the high hardness region, when viewed in cross section along a plane including an axis of the spark plug and an axis of the ground electrode, has a length d of 0.3 to 0.8 mm from a ground electrode side welding boundary to a metal shell side welding boundary in a direction of load applied during the electric resistance welding. | ||
| 申请公布号 | US8952601(B2) | 申请公布日期 | 2015.02.10 |
| 申请号 | US201113994778 | 申请日期 | 2011.12.22 |
| 申请人 | NGK Spark Plug Co., Ltd. | 发明人 | Kuno Takehito;Yoshimoto Osamu;Tanaka Tomoo |
| 分类号 | H01T13/02;C22C19/03;H01T13/32;H01T21/02;C22C19/00;H01T13/39 | 主分类号 | H01T13/02 |
| 代理机构 | Kusner & Jaffe | 代理人 | Kusner & Jaffe |
| 主权项 | 1. A spark plug, comprising: a cylindrical metal shell; a ground electrode joined by electric resistance welding to an end portion of the metal shell, wherein the metal shell has a high hardness region formed with a Vickers hardness of 3×102 to 5×102 Hv in the end portion thereof in such a manner that the high hardness region, when viewed in cross section along a plane including an axis of the spark plug and an axis of the ground electrode, has a length d of 0.3 to 0.8 mm from a ground electrode-side welding boundary to a metal shell-side welding boundary in a direction of load applied during the electric resistance welding. | ||
| 地址 | Aichi JP | ||