Ngk Spark Plug Company, Limited

Kabushiki Kaisha Tokai Rika Denki Seisakusho

Toyota Jidosha Kabushiki Kaisha

Toru Nakamura

Shinji Ichikawa

Tomoaki Kato

Yuichi Yamada

Chikao Nagasaka

Yoshikuni Sato

Masaki Hayashi

Yukihiro Yamamoto

Daisuke Nakano

Toshiyuki Isogai

Shinji Kishida

Hiroaki Nasu

Hiroshi Tsuge

Yoshimasa Kunimatsu

Satoshi Nagasawa

Masaru Sasaki

Naoki Kamiya

Taira Kikuchi

Iwao Kunitomo

Katsunori Hagiwara

Wataru Matutani

Yoshihiro Ohkura

A spark plug comprising: a center electrode extending along an axis; an insulator provided about the outer peripheral surface of the center electrode; a metal shell provided about the outer peripheral surface of the insulator; a noble metal tip provided at the leading end portion of the center electrode; one end of the ground electrode fixed at the leading end of the metal shell, and the other end of the ground electrode forming a gap with the leading end of the noble metal tip; a stopper preventing the noble metal tip from moving relative to the central electrode; a molten portion formed by irradiating laser or electron beam; and a closed space formed between the basal portion of the noble metal tip and the center electrode. The molten portion welds the center electrode and a part of the basal portion of the noble metal tip.

Spark plug for internal combustion engine and manufacturing method thereof

A method for manufacturing an ignition plug is provided. The method includes: preparing an insulator having a cavity provided at a leading end portion thereof by disposing a leading end of a center electrode more inwards in an axial hole than a leading end of the insulator; building the insulator in an interior of a metal shell; disposing a ground electrode at a leading end portion of the metal shell; positioning a center of a through hole of the ground electrode and a center of the cavity of the insulator; and welding the ground electrode and the metal shell together after the positioning step.

Method for manufacturing ignition plug

A control system for controlling the ignition of a plasma-jet spark plug provided in an internal combustion engine senses an operating condition of the internal combustion engine, and determines an ignition mode of the plasma-jet spark plug in accordance with the sensed operating condition. The control system performs an ignition control of breaking down the insulation across a spark discharge gap by applying a first electric power to the plasma-jet spark plug, and producing plasma in the vicinity of the spark discharge gap by applying a second electric power to the spark discharge gap in a state of dielectric breakdown. The control system performs this ignition control according to the ignition mode determined as mentioned above.

Plasma jet ignition plug ignition control

Plasma jet spark plug

The cavity of a plasma jet ignition plug is configured in a stepped shape; i.e., composed of a constricted portion and a diameter-increased portion (). The inner diameter (B) of the constricted portion is made smaller than the inner diameter (A) of the diameter-increased portion. Further, as measured along the direction of the axis O, the length (Y) of the constricted portion is made equal to or greater than the length (X) of the diameter-increased portion. This configuration suppresses a pressure loss produced when the generated plasma expands within the cavity. As a result, the energy of the plasma at the time of jetting is increased, and the igniting performance for an air-fuel mixture can be improved.

Plasma jet ignition plug and ignition device for the same

A plasma jet ignition plug capable of inhibiting occurrence of channeling while reducing removal of energy of plasma through a ground electrode at the time of emission of plasma. A ground electrode of a plasma jet ignition plug projects inward from a front end face of a metallic shell toward an opening end of a cavity which is open at a front end face of an insulator. A projecting distal end which forms a spark discharge gap between the same and a center electrode within a cavity is located inward, with respect to a diametral direction P orthogonal to an axis O, of a position which is located 0.5 mm radially outward from the opening end of the cavity.

Plasma jet ignition plug

A manufacturing method for an ignition plug is provided. The method includes: preparing an insulator having a cavity provided at a leading end portion thereof by disposing a leading end of the center electrode more inwards than a leading end of the insulator; building the insulator in an interior of the metal shell such that the leading end of the insulator is situated closer to a rear end side than the leading end of the metal shell; removing at least part of a leading end portion of the metal shell which projects from a leading end face of the insulator; and disposing the ground electrode at the leading end portion of the metal shell and welding the ground electrode and the metal shell together after the removal step.

Manufacturing method for ignition plug involves removing leading end portion of shell extended from end surface of insulator

An ignition device for a plasma jet ignition plug is provided. A resistance for decreasing electric noises is not incorporated in a plasma jet ignition plug. A resistance of not less than 1K&#x3a9; and not more than 20K&#x3a9; is provided to a path from a spark discharge circuit to a center electrode, thus reducing the generation of electric noises at the time of trigger discharge. Along with the reduction of the generation of electric noises, a loss of energy at the time of plasma discharge can be reduced by setting an inner resistance provided to a line extending to the center electrode from a plasma discharge circuit to 1&#x3a9; or less. Accordingly, the plasma jet ignition plug can jet flame-shaped plasma sufficiently large for igniting an air-fuel mixture.

Ignition device for plasma jet ignition plug

A plasma jet spark plug and a manufacturing method therefor are disclosed. In a state in which a noble-metal chip having a flange-like outwardly projecting portion is disposed in a communication section of a ground electrode, an electrode base metal of the ground electrode is disposed in a stepped engagement portion of a metallic shell, which retains an insulator therein. While being pressed against a front end portion of the insulator, the noble-metal chip is joined to the electrode base metal, whereby a clearance between the ground electrode (electrode base metal) and the front end portion of the insulator can be closed. Therefore, energy of plasma generated within the cavity does not leak.

Plasma jet spark plug and manufacturing method therefor

A plasma-jet spark plug comprising an insulator and a ground electrode which are disposed apart from each other in an axial direction (O) to prevent a damage of the insulator. The spark plug is capable of reducing an energy loss of the ejected plasma by defining a dimension of a clearance between the insulator and the ground electrode whereby deterioration of the ignitability of the plasma-jet spark plug is prevented.

Plasma-jet spark plug

A plasma-jet spark plug includes a metal shell, an electrical insulator retained in the metal shell, a center electrode held in an axial hole of the electrical insulator to define a cavity by a front end face of the center electrode and an inner circumferential surface of the insulator axial hole and a ground electrode arranged on a front end of the electrical insulator. The ground electrode has an opening defining portion defining an opening for communication between the cavity and the outside of the spark plug. The opening defining portion is located radially inside of or in contact with a first imaginary circular conical surface where the first imaginary circular conical surface has an axis coinciding with an axis of the spark plug and a vertex angle of 120&#xb0; opening toward a front end of the spark plug and passing through a front edge of the insulator axial hole.

Plasma-jet spark plug and ignition system

A vehicle engine starting apparatus has an engine start switch, a display device and a microcomputer. The display device shows the location of the start switch. The microcomputer identifies a specific signal, and controls the display device in accordance with the result of the identification executed by the microcomputer.

Vehicle engine starting apparatus

A vehicular remote control apparatus warns a driver when the driver moves from the inside of a vehicle to the outside of the vehicle while an engine is operating. The vehicular remote control apparatus is located inside the vehicle and includes a transmitter-receiver for generating a first request signal and a portable device for generating a transmission signal in response to the first request signal and transmitting the transmission signal to the transmitter-receiver. The first request signal is transmitted to outside the vehicle. The transmitter-receiver includes a determining device for determining whether the engine is operating and a warning signal transmission device for generating a first warning signal if the engine is operating when receiving the transmission signal and transmitting the first warning signal to the portable device located outside the vehicle. The portable device includes a warning device for giving a warning when the portable device receives the first warning signal.

Vehicular remote control apparatus and engine operation warning method

An apparatus for controlling a vehicle transmission includes a camera that generates an image signal indicating the situation in front and behind the vehicle, a shift operation body that generates an operation signal indicating a shift operation position of the shift operation body that is operated by a driver, and a control unit that controls the transmission in accordance with the operation signal. The control unit determines whether movement of the vehicle is obstructed on the basis of the image signal and invalidates the operation signal to prohibit the operation of the transmission.

Growing community of inventors

Aichi, Japan

Toru Nakamura