Title:
SPARK PLUG AND MANUFACTURING METHOD THEREFOR
Document Type and Number:
Japanese Patent JP2019175707
Kind Code:
A
Abstract:
To provide a spark plug in which a reduction of diameter of a spark plug and improvement of voltage endurance are compatible, and to provide a manufacturing method therefor.SOLUTION: A gap between an outside 31 of a center electrode 3 at a base end side, and an inside 21 of an insulator 2 is filled with conductive glass powder, and then heated and cooled thus manufacturing a spark plug 1. A size Tmm of the gap and an average particle size X of the conductive glass powder satisfy a relation of the following formula I. In the spark plug 1, the maximum diameter Ymm of a gas cavity 411 adjacent to the inside 21, out of the gas cavities 41 existing in the conductive glass seal part 4 at an interval 150 between the inside 21 and the outside 31, and the size Tmm of the interval 150 satisfy the relation of the following formula VI. 1056(X-0.144)+204(X-0.144)(T-0.2)+10.6X-40.6T<5.46 ... (I), 444Y-13T<26.6 ... (VI).SELECTED DRAWING: Figure 3
Inventors:
WATANABE TOMOYUKI
Application Number:
JP2018063033A
Publication Date:
October 10, 2019
Filing Date:
March 28, 2018
Export Citation:
Assignee:
DENSO CORP
International Classes:
H01T13/20; H01T13/34; H01T21/02
Domestic Patent References:
| JP2013187049A | 2013-09-19 |
Foreign References:
| WO2013031232A1 | 2013-03-07 |
Attorney, Agent or Firm:
Patent Business Corporation Aichi International Patent Office