公开(公告)号：US11652335B2

公开(公告)日：2023-05-16

申请号：US17619944

申请日：2020-12-22

Applicant: NGK SPARK PLUG CO., LTD.

Inventor： Seiji Nakano ,  Kengo Fujimura ,  Shota Takaenoki

IPC: H01T13/34 ,  H01T13/36

CPC classification number: H01T13/34 ,  H01T13/36

Abstract: To prevent a sealant from intruding between a flange and a stepped portion during manufacture of a spark plug and to prevent cracking of an insulator during use of the spark plug, a spark plug includes a center electrode including a flange, an insulator having a through-hole extending in an axial-line direction and holding the center electrode, and a sealant filled in the through-hole to fix the flange and the insulator to each other; the insulator including a stepped portion in which the through-hole reduces a diameter toward a front end side and that supports the flange, and a small-diameter portion that is continuous with a front end side of the stepped portion and in which the diameter of the through-hole is smaller than in the stepped portion; an angle θ1 formed by the stepped portion and a plane perpendicular to the axial line and an angle θ2 formed by the plane perpendicular to the axial line and an opposing surface of the flange opposing the stepped portion satisfies θ1−θ2≥6°, and in a cross section including the axial line, a maximum diameter D1 of the flange and a diameter D2 of the through-hole at a rear end of the small-diameter portion in the axial-line direction satisfy 0.15 mm≤(D1−D2)/2.

公开(公告)号：US11005237B2

公开(公告)日：2021-05-11

申请号：US16902321

申请日：2020-06-16

Applicant: NGK SPARK PLUG CO., LTD.

Inventor： Seiji Nakano ,  Kengo Fujimura ,  Shoma Tsumagari

IPC: H01T13/34

Abstract: An ignition plug comprising: an insulator having a through hole extending from a rear-end side toward a forward-end side; a center electrode inserted at least partially into a portion of the through hole on the forward-end side; a metal terminal member inserted at least partially into a portion of the through hole on the rear-end side; and a seal disposed within the through hole and in contact with the center electrode and an inner circumferential surface of the insulator. The seal contains a glass and an electrically conductive substance, and the glass contained in the seal contains Si in an amount of 50 mass % or more as reduced to SiO2 and Na in an amount of 0.1 mass % or more and less than 1 mass % as reduced to Na2O.

公开(公告)号：US11695257B2

公开(公告)日：2023-07-04

申请号：US17802334

申请日：2021-11-04

Applicant: NGK SPARK PLUG CO., LTD.

Inventor： Seiji Nakano ,  Takehito Kuno ,  Kota Yamauchi

IPC: H01T13/34 ,  H01T13/39 ,  H01T13/05

CPC classification number: H01T13/39 ,  H01T13/05 ,  H01T13/34

Abstract: A spark plug has an insulator having a through hole formed along an axial direction, a center electrode which is partially inserted into a portion of the through hole on a forward end side in the axial direction, and a glass seal portion which is in contact with the insulator and the center electrode within the through hole, in which the glass seal portion contains glass and an electrically conductive substance. The glass contains an Si component and a B component in a total amount of 50 mass % or more, as reduced to SiO2 and B2O3, a Zn component in an amount of 20 mass % to 35 mass % as reduced to ZnO, and an alkali metal component. The glass contains, as the alkali metal component, an Na component in an amount less than 1 mass % as reduced to Na2O.

公开(公告)号：US10424901B2

公开(公告)日：2019-09-24

申请号：US16095788

申请日：2017-05-25

Applicant: NGK SPARK PLUG CO., LTD.

Inventor： Jumpei Isasa ,  Seiji Nakano ,  Hirokazu Kurono ,  Kuniharu Tanaka ,  Yutaka Yokoyama ,  Haruki Yoshida ,  Shun Kondo

IPC: H01T13/32 ,  H01T13/20 ,  H01T13/06

Abstract: Provided is a spark plug capable of ensuring fouling resistance with a simple configuration. An insulator includes a step portion formed on an outer circumferential surface thereof. A center electrode is arranged in an axial hole of the insulator. A cylindrical metal shell having a shelf portion formed on an inner circumferential surface thereof is arranged radially outside the insulator. The insulator further includes a front end portion located frontward of the step portion. An outer circumferential surface of the front end portion has an arithmetic average roughness of 0.5 μm or smaller in a circumferential direction. A recess is formed with a depth of 3 to 20 μm in at least part of an end surface and the outer circumferential surface of the front end portion so as to extend from the front toward the rear.

公开(公告)号：US10084288B2

公开(公告)日：2018-09-25

申请号：US15738650

申请日：2016-06-02

Applicant: NGK SPARK PLUG CO., LTD.

Inventor： Hironori Uegaki ,  Seiji Nakano ,  Hirokazu Kurono

IPC: H01T13/34 ,  H01T13/41 ,  H01T13/32

Abstract: A spark plug including a metallic shell having a ground electrode, an insulator held inside the metallic shell and having an axial hole having a small diameter portion, an intermediate diameter portion connected to a rear end of the small diameter portion via a step portion, and a large diameter portion disposed on the rear side of the intermediate diameter portion, a resistor disposed inside the large diameter portion, a center electrode having a flange portion which bulges in a radial direction inside the intermediate diameter portion and comes into contact with the step portion and a leg portion which extends forward from the flange portion and is disposed inside the small diameter portion, and a seal disposed on the rear side of the step portion and electrically connecting the center electrode and the resistor. The rear end of the seal is located inside the intermediate diameter portion.

公开(公告)号：US09871352B2

公开(公告)日：2018-01-16

申请号：US15415173

申请日：2017-01-25

Applicant: NGK Spark Plug Co., LTD.

Inventor： Seiji Nakano ,  Kouta Yamauchi ,  Hironori Uegaki

IPC: H01T13/34 ,  H01T21/02

CPC classification number: H01T13/34 ,  H01T13/41 ,  H01T21/02

Abstract: The spark plug includes: an insulator having a through hole that penetrates therethrough along an axial direction; a center electrode disposed on one end side of the through hole; a metal terminal disposed on the other end side of the through hole; and a conductive seal layer connected to at least one of the center electrode and the metal terminal. The conductive seal layer contains glass and a Cu—Zn alloy. A volumetric percentage of the Cu—Zn alloy in the conductive seal layer is greater than or equal to 44% and not greater than 55%.