公开(公告)号：US09954344B2

公开(公告)日：2018-04-24

申请号：US15550458

申请日：2016-02-10

Applicant: DENSO CORPORATION

Inventor： Kenji Hattori ,  Masamichi Shibata ,  Toshiya Nakamura ,  Yasuomi Imanaka ,  Hirofumi Suzuki ,  Hiroshi Araki ,  Tomoyuki Watanabe ,  Shin Hase

IPC: H01T13/41 ,  H01T13/40 ,  H01C13/00 ,  F02P15/00

CPC classification number: H01T13/41 ,  F02P13/00 ,  F02P15/00 ,  H01C13/00 ,  H01T13/20

Abstract: A spark plug 1 includes a cylindrical housing, a cylindrical insulator, a center electrode, a terminal bracket, a ground electrode, and a resistor. The insulator is held on the inside of the housing. The center electrode 4 is held on the inside of the insulator, with a tip end being projected therefrom. The terminal bracket is held on the inside of the insulator, with a base end part and being projected therefrom. The ground electrode forms a spark discharge gap G between itself and the center electrode. The resistor contains carbon and is disposed on the inside of the insulator so as to be located between the center electrode 4 and the terminal bracket. In an axial direction X of the spark plug, the resistor has a higher carbon content in a first region positioned on a tip side, compared to a second region positioned on a base end side.

公开(公告)号：US10811852B2

公开(公告)日：2020-10-20

申请号：US16571250

申请日：2019-09-16

Applicant: DENSO CORPORATION

Inventor： Tomoyuki Watanabe

IPC: H01T13/41 ,  H01T1/16 ,  H01C7/108 ,  H01T13/34

Abstract: A spark plug which is capable of further improving load life performance and a resistor material for a spark plug are provided.A spark plug includes a center electrode, a terminal fitting, and a resistor disposed between the center electrode and the terminal fitting. The resistor contains glass, a zirconia-based material and an electrically conducting material. The zirconia-based material contains at least stabilized zirconia.

公开(公告)号：US10050417B2

公开(公告)日：2018-08-14

申请号：US15692254

申请日：2017-08-31

Applicant: DENSO CORPORATION

Inventor： Ryohei Akiyoshi ,  Ken Hanashi ,  Tomoyuki Watanabe

IPC: H01T13/20 ,  H01T13/32 ,  H01T13/02 ,  H01T13/34 ,  H01T13/08 ,  H01T21/02

Abstract: Disclosed herein is a spark plug capable of suppressing electrode consumption caused by a spark discharge and a method of manufacturing the same. A section except a welded section formed by welding a tip surface of a center electrode is defined as an unwelded section in side surfaces of a center chip, and a length of the unwelded section along a center axis of the center chip is defined as an unwelded section length. Under this definition, the welded section is formed in order for an unwelded section length in a side surface opposite to an inclination direction side of the center chip in the center chip to become longer than an unwelded section length in a side surface of the inclination direction side of the center chip in the center chip.

公开(公告)号：US09935429B2

公开(公告)日：2018-04-03

申请号：US15690756

申请日：2017-08-30

Applicant: DENSO CORPORATION

Inventor： Ken Hanashi ,  Ryohei Akiyoshi ,  Tomoyuki Watanabe

IPC: H01T13/20 ,  H01T13/32 ,  H01T13/39 ,  H01T21/02

CPC classification number: H01T13/32 ,  H01T13/39 ,  H01T21/02

Abstract: In the spark plug, at least one of the center chip and the ground chip is bonded with a center electrode or a ground electrode. The selected chip has a first part formed so as to linearly extend along a first center axis of an electrode bonded with the first part and a second part formed so as to extend linearly from a tip end of the first part along a second central axis inclined with respect to the first central axis.

公开(公告)号：US10348060B2

公开(公告)日：2019-07-09

申请号：US15687854

申请日：2017-08-28

Applicant: DENSO CORPORATION

Inventor： Tomoyuki Watanabe ,  Ryohei Akiyoshi ,  Ryuichi Ohno

IPC: H01T13/32

Abstract: When one of a center chip and a ground chip of a spark plug is defined as a first chip and another one is defined as a second chip, a discharge starting ridge line, which is a straight ridge line that forms a boundary between two surfaces having different normal line directions, is formed in a portion closest to the second chip in the first chips, and a distance from the discharge starting ridge line to the second chip is configured to be equal at a portion where the first chip and the second chip are opposed to each other.

公开(公告)号：US09831638B2

公开(公告)日：2017-11-28

申请号：US15473685

申请日：2017-03-30

Applicant: DENSO CORPORATION

Inventor： Tomoyuki Watanabe ,  Hiroshi Araki

IPC: H01T13/41 ,  H01T13/39 ,  H01T13/32

CPC classification number: H01T13/41 ,  H01T13/20 ,  H01T13/32 ,  H01T13/39

Abstract: The spark plug has a shaft shaped center electrode, insulator, terminal fitting, ground electrode and resistor. The insulator has an axially penetrating shaft hole, and the center electrode is held in a tip end side of the shaft hole. The terminal fitting has a shaft and a terminal part. The shaft is held in a base end side of the shaft hole. The terminal part is projected from a base end of the shaft hole to a base end side of the spark plug. The ground electrode faces the center electrode in a tip end side of the shaft hole. The resistor is disposed between the center electrode and the terminal fitting in the shaft hole. An axial length L of the resistor is 15 mm≦L≦22.5 mm. An axial length T of the shaft satisfies a relation of 1.25≦T/L.