公开(公告)号：US10886708B2

公开(公告)日：2021-01-05

申请号：US16584998

申请日：2019-09-27

Applicant: DENSO CORPORATION

Inventor： Shintaro Itoh ,  Daisuke Tanaka ,  Akimitsu Sugiura ,  Ryota Wakasugi ,  Kaori Doi ,  Kanechiyo Terada ,  Tetsuya Miwa ,  Fumiaki Aoki

IPC: H01T13/32 ,  H01T13/52

Abstract: A spark plug has a tubular ground electrode, an insulator, and a center electrode. The insulator has an insulator protruding portion protruding to a tip end side in a plug axial direction with respect to the ground electrode. The center electrode 4 has an exposed portion exposed through a tip end of the insulator protruding portion. The exposed portion of the center electrode has a first part covering the insulator protruding portion from the tip end side in the plug axial direction, and a second part extending from the first part to a base end side in the plug axial direction and covering the entire circumference of an outer peripheral surface of the insulator protruding portion from an outer peripheral side in a plug radial direction.

公开(公告)号：US10697419B2

公开(公告)日：2020-06-30

申请号：US16079120

申请日：2017-02-13

Applicant: DENSO CORPORATION

Inventor： Daisuke Tanaka ,  Shota Kinoshita ,  Noriaki Nishio ,  Satoru Nakayama

IPC: F02P3/05 ,  F02P15/00 ,  H01T13/20 ,  F02P9/00 ,  H01T13/14 ,  F02P15/10 ,  F02P3/01 ,  F02P7/03 ,  F02P17/12 ,  F02P3/04

Abstract: An ignition control apparatus applied to an internal combustion engine including a spark plug includes an in-cylinder pressure acquisition section, a frequency signal transmitting section which transmits a frequency signal having a predetermined frequency to a switching element, and a weak discharge generating section which causes the frequency signal to be transmitted during an intake stroke and controls the frequency signal such that a weak discharge is generated at the spark plug a plurality of times. The weak discharge generating section controls the frequency signal so as to cause a duty ratio of the switching element to be changed in accordance with the in-cylinder pressure, such that the frequency of generating weak discharges during a time period in which the frequency signal is transmitted becomes higher than a predetermined frequency.

公开(公告)号：US11129268B2

公开(公告)日：2021-09-21

申请号：US15914101

申请日：2018-03-07

Applicant: DENSO CORPORATION ,  PLASMA APPLICATIONS CO., LTD.

Inventor： Shota Kinoshita ,  Fumiaki Aoki ,  Daisuke Tanaka ,  Akimitsu Sugiura ,  Jan Husarik ,  Masashi Kando

IPC: H05H1/46 ,  H05H1/00 ,  H01T15/00 ,  H01T13/50 ,  F02P3/01 ,  H01T13/40 ,  H05H1/52 ,  H01T13/52

Abstract: An ignition apparatus is provided which ignites a mixture of air and fuel gas by plasma to generate an initial flame. The apparatus includes: a spark plug that includes an inner conductor, a cylindrical outer conductor that holds the inner conductor thereinside, and a dielectric that is provided between the inner conductor and the outer conductor, and that generates plasma in a plasma formation space between the inner conductor and the outer conductor; an electromagnetic wave power supply that generates an electromagnetic wave to apply electromagnetic wave power to the spark plug; an evaluation section that evaluates a state of formation of the plasma; a determination section that determines a matching object of the electromagnetic wave based on an evaluation result by the evaluation section; and a coupled state control section that controls a matching condition of the electromagnetic wave so that the electromagnetic wave matches the matching object.

公开(公告)号：US10718310B2

公开(公告)日：2020-07-21

申请号：US15755709

申请日：2016-08-23

Applicant: DENSO CORPORATION ,  THE UNIVERSITY OF TOKYO

Inventor： Masaaki Kono ,  Daisuke Tanaka ,  Takaaki Sato ,  Akimitsu Sugiura ,  Mitsuhiro Tsue ,  Shinji Nakaya

IPC: F02P3/00 ,  F02P3/01 ,  F02P23/04 ,  F02P3/04 ,  F02P15/10 ,  F02P3/05 ,  F02P9/00 ,  F02P15/02 ,  F02P17/12 ,  F02P15/08 ,  F02P5/04 ,  F02P1/00

Abstract: An ignition apparatus includes a plasma device, a first circuit, a second circuit, and a control unit. The plasma device produces a plasma discharge in an air-fuel mixture before an arc discharge is produced. The first circuit causes an ignition plug to start the arc discharge. The second circuit energizes a primary coil in a direction opposite to the direction of the energization by the first circuit during the arc discharge, to maintain energization of the secondary coil in the same direction as the direction of the energization started by an operation of the first circuit, to cause continuation of the arc discharge. The control unit controls operations of the first circuit, the second circuit, and the plasma device.

公开(公告)号：US11181090B2

公开(公告)日：2021-11-23

申请号：US16007174

申请日：2018-06-13

Applicant: DENSO CORPORATION ,  PLASMA APPLICATIONS CO., LTD.

Inventor： Shota Kinoshita ,  Fumiaki Aoki ,  Daisuke Tanaka ,  Akimitsu Sugiura ,  Jan Husarik ,  Masashi Kando

IPC: F02P9/00 ,  F02P3/01 ,  H01T15/00 ,  H01T13/50 ,  F02P23/04

Abstract: In an ignition apparatus, an ignition plug is provided. In the ignition plug, a tubular outer conductor surrounds an inner conductor, and a dielectric member is disposed in the tubular outer conductor to define a plasma formation region between the inner conductor and the dielectric member. The plasma formation region has opposing first and second ends in the axial direction of the tubular outer conductor, and the first end of the plasma formation region communicates with the combustion chamber. A power source is connected between the inner and tubular outer conductors. A controller causes a power source to apply electromagnetic power pulses with intervals therebetween across the inner and tubular outer conductors during an ignition cycle of an engine. Each of the electromagnetic power pulses forms at least a corresponding plasma in the plasma formation region.

公开(公告)号：US10833487B2

公开(公告)日：2020-11-10

申请号：US16454510

申请日：2019-06-27

Applicant: DENSO CORPORATION

Inventor： Yuuki Kawata ,  Daisuke Tanaka ,  Daisuke Shimamoto ,  Naoto Hayashi

IPC: H01T13/34 ,  H01T13/08

Abstract: An ignition apparatus for an internal combustion engine includes a center electrode, a ground electrode, an insulator, a housing, and an insulator protective wall portion. The ground electrode is disposed such that a discharge gap is formed between the ground electrode and the center electrode. The insulator holds the center electrode on an inner side of the insulator. The housing holds the insulator on an inner side of the housing. The insulator protective wall portion is arranged to surround an outer circumference side of a distal end portion of the insulator. A distal end of the insulator protective wall portion is positioned further towards a distal end side than a distal end of the insulator is and further towards a proximal end side than a distal end of the center electrode is. The insulator protective wall portion includes an inward protruding portion that protrudes towards a side surface of the center electrode.

公开(公告)号：US10454252B2

公开(公告)日：2019-10-22

申请号：US16143857

申请日：2018-09-27

Applicant: DENSO CORPORATION

Inventor： Daisuke Tanaka ,  Fumiaki Aoki ,  Akimitsu Sugiura

IPC: H01T13/32 ,  H01T13/04 ,  H01T13/38

Abstract: A spark plug for an internal combustion engine is provided which has a center electrode and a ground electrode. The ground electrode includes an upright portion extending in a lengthwise direction of the spark plug and an extension bent from the upright portion in a radial direction of the spark plug. The extension has a slant surface which is shaped to be inclined away from the center electrode downstream in a flow of air-fuel mixture within a combustion chamber when the spark plug is mounted in the engine. This results in an increase in in distance by which a starting point on the ground electrode where a spark is created is moved on the slant surface, thereby increasing a length of time the spark is moved downstream and then blown out to increase the probability of successful ignition of the air-fuel mixture.

公开(公告)号：US20180363618A1

公开(公告)日：2018-12-20

申请号：US16007174

申请日：2018-06-13

Applicant: Denso Corporation ,  Plasma Applications Co., Ltd.

Inventor： Shota Kinoshita ,  Fumiaki Aoki ,  Daisuke Tanaka ,  Akimitsu Sugiura ,  Jan Husarik ,  Masashi Kando

IPC: F02P9/00 ,  F02P23/04

Abstract: In an ignition apparatus, an ignition plug is provided. In the ignition plug, a tubular outer conductor surrounds an inner conductor, and a dielectric member is disposed in the tubular outer conductor to define a plasma formation region between the inner conductor and the dielectric member. The plasma formation region has opposing first and second ends in the axial direction of the tubular outer conductor, and the first end of the plasma formation region communicates with the combustion chamber. A power source is connected between the inner and tubular outer conductors. A controller causes a power source to apply electromagnetic power pulses with intervals therebetween across the inner and tubular outer conductors during an ignition cycle of an engine. Each of the electromagnetic power pulses forms at least a corresponding plasma in the plasma formation region.

公开(公告)号：US10951011B2

公开(公告)日：2021-03-16

申请号：US16912751

申请日：2020-06-26

Applicant: DENSO CORPORATION

Inventor： Daisuke Tanaka ,  Fumiaki Aoki ,  Naoto Hayashi ,  Daisuke Shimamoto

IPC: H01T13/32

Abstract: A spark plug includes a housing, an insulator, a center electrode, and an earth electrode. The earth electrode has a gap-forming surface which forms a discharge gap between the gap-forming surface and a tip surface of the center electrode. The insulator includes an insulator protrusion protruding on the tip side of the housing in a plug axial direction. At least one of cross-sections passing through a plug center axis and parallel to the plug axial direction is referred to as an axial parallel cross-section. The outer peripheral surface of the insulator protrusion includes an insulator inclined surface extending inward toward the tip in the plug axial direction, in a straight line or a curve that is convex inward, in the axial parallel cross-section. In the axial parallel cross-section, a virtual straight line passing through both ends of the insulator inclined surface passes through the gap-forming surface.

公开(公告)号：US10855057B2

公开(公告)日：2020-12-01

申请号：US16520392

申请日：2019-07-24

Applicant: DENSO CORPORATION

Inventor： Ryota Wakasugi ,  Fumiaki Aoki ,  Daisuke Tanaka ,  Akimitsu Sugiura ,  Tetsuya Miwa ,  Kanechiyo Terada

IPC: H01T13/20

Abstract: In a spark plug for an internal combustion engine, a cylindrical insulator is arranged radially inside a cylindrical ground electrode, and includes an insulator protruding portion protruding further toward a distal end side in an axial direction than a distal end of the ground electrode. A center electrode is held radially inside the insulator, and includes an exposed portion exposed from a distal end of the insulator protruding portion. The spark plug generates a discharge from the exposed portion to the ground electrode, in a discharge gap formed along a surface of the insulator protruding portion. At least one of the exposed portion and the insulator protruding portion includes a flow inlet that is open on an outer circumferential surface thereof, a flow outlet that is open toward the discharge gap, and a communication passage communicating between the flow inlet and the flow outlet.