Denso Corporation

Nippon Soken, Inc.

Nippondenso Co., Ltd.

Other

Keiji Kanao

Shinichi Okabe

Tsunenobu Hori

Tetsuya Miwa

Ken Hanashi

Hironori Osamura

Tohru Yoshinaga

Nobuo Abe

Hiroshi Yorita

Takehiko Kato

Hitoshi Morita

Kenka Tsubota

Tsunetoshi Goto

Kenji Horibe

Taiji Koyama

Masayuki Tamura

Kozo Takamura

Masato Ozawa

Hirofumi Noda

Akio Katoh

Seiki Nakagawa

Kaneo Buma

Kouzou Takamura

Tunenobu Hori

Akio Kato

Kouichi Hirano

In a gas sensor sensing a specific gas component contained in gas to be measured, oxygen ion conductive solid electrolyte is used in a sensing element for sensing the specific gas component. A terminal unit is used, which comprises a pair of insulators, each having an inner side surface, disposed to pinch and hold the base end portion of the sensing element on the pair of electrode-mounted surfaces of the sensing element. The terminal unit comprises two pairs of metal terminals and a spring member. The metal terminals electrically contact electrode pads of the sensing element, pair by pair, respectively, and are disposed on the inner side surfaces of the insulators. The spring members press the pair of insulators at one or more positions of electrode-mounted surfaces of the sensing element in a width direction so that the insulators are pressed to be opposed to each other.

Gas sensor and method of manufacturing thereof

A spark plug includes a tubular metal shell, an insulator, a cylindrical center electrode, and a ground electrode. The ground electrode has an inclined portion, a straight portion, and a bend between the inclined and straight portions. The inclined portion extends obliquely with respect to the axial direction of the center electrode from a base end of the ground electrode, which is joined to an end of the metal shell, to the bend that is positioned closer to the center electrode in the radial direction of the center electrode than the base end. The straight portion extends substantially parallel to the axial direction of the center electrode from the bend to a tip end of the ground electrode. The straight portion has an inner side surface facing the side surface of an end portion of the center electrode through a spark gap in the radial direction of the center electrode.

Spark plug for internal combustion engine and manufacturing method thereof

The gas sensor includes a sensor element having electrode pads formed in its electrode forming surfaces at the proximal end portion thereof, an insert-holding insulator insert-holding the sensor element, a housing insert-holding the insert-holding insulator, and a terminal unit. The proximal end portion of the sensor element is held by the terminal unit which includes a pair of proximal end insulators formed with metal terminals at their inner surfaces, and a spring member pressing the proximal end insulators in a direction that they approach each other. Each of the proximal end insulators includes an insulator contact portion in contact with one of the electrode forming surfaces. The insulator contact portion is located closer to the proximal end of the sensor element than a terminal contact portion at which the metal terminal contacts a corresponding one of the electrode pads.

Gas sensor and method of manufacturing same

Spark plug for internal combustion engine

A spark plug for an internal combustion engine is provided which includes a metal shell, a porcelain insulator, a center electrode, a main ground electrode, and auxiliary ground electrodes. Each of the auxiliary ground electrodes has an end face facing the insulator to define an auxiliary spark gap. The end face includes an increasing-radial distance surface which is located at a distance from a longitudinal center line of the spark plug in a radial direction thereof which increases as approaching to the metal shell. The insulator nose has a wall thickness T meeting a relation of 0.3 mm&#x2266;T&#x2266;0.7 mm. This avoids a great local increase in electrical field strength on the auxiliary ground electrode to minimize excessive discharge within the auxiliary spark gap to enhance carbon fouling resistance and durability of the spark plug.

Spark plug with increased durability and carbon fouling resistance

A gas sensor having a housing, a first insulation porcelain, a metal sealing member interposed between a seat surface of the housing and a contacting surface of the first insulation porcelain. The metal sealing member is made of a Fe-based alloy of containing 10 wt % or less Cr.

Gas sensor

A spark plug for an internal combustion engine is provided which has a center electrode made up of an oxidation resistant alloy-made portion and a thermal conductive metal-made portion. The oxidation resistant alloy-made portion occupies at least a top portion of the center electrode exposed outside a porcelain insulator. The thermal conductive metal-made portion is exposed to a portion of an outer periphery of the center electrode which faces a insulator mount portion of a spark-mounting shell through the porcelain insulator in a direction perpendicular to an axial direction of the center electrode, thereby facilitating transfer or dispersal of heat from the center electrode to the mounting shell through the porcelain insulator to ensure a desired heat range.

Compact structure of spark plug designed to ensure desired heat range

A spark plug includes a metal shell, an insulator, a center electrode, a ground electrode, a first noble metal chip, and a second noble metal chip. The metal shell has a threaded portion with an outer diameter of equal to or less than 14 mm for installing the spark plug to an internal combustion engine. The parameters in the structure of the spark plug, such as an end surface area S of the first noble metal chip, a length A of the first noble metal chip, an end surface area Q of the second noble metal chip, a length B of the second noble metal chip, an air pocket size L, a space G of a spark gap, a ratio L/G, and a thickness T of the insulator, have suitable dimensional ranges determined through experimental investigation. The structure ensures high performance and a long service life for the spark plug.

High performance, long-life spark plug

A power-saving type of ignition apparatus is provided with a spark plug of which electrodes () are regulated in their shapes to lower an amount of energy required for its ignition. To face to a tip () of a center electrode () extending from a mounting bracket (), a cylindrical protrusion () is built on one surface () of an earth electrode (). The protrusion extends toward the center electrode to form a discharge gap () between the protrusion and the tip of the center electrode. Both of the tip of the center electrode and the protrusion of the earth electrode are 2.3 [mm] or less in each diameter (D, D), thus an amount of energy required for ignition being limited to 17 [mJ] or less.

Spark plug and ignition apparatus using same

A spark plug for an internal combustion engine is provided which includes a metal shell, a porcelain insulator, a center electrode, a main ground electrode, and auxiliary ground electrodes. Each of the auxiliary ground electrodes has an inner side surface facing the center electrode through the porcelain insulator to define an auxiliary spark gap between itself and a nose of the porcelain insulator so as to occupy a minimum distance between the porcelain insulator and the auxiliary ground electrode. This avoids a great local increase in electrical field strength on the auxiliary ground electrode to minimize excessive discharge within the auxiliary spark gap to enhance carbon fouling resistance and durability of the spark plug.

A spark plug includes a metal shell, an insulator, a center electrode, a ground electrode, and a terminal fixed to the insulator. The dimensional parameters in the structure of the spark plug, such as a maximum diameter A of the terminal and a diameter B of the insulator satisfy a dimensional relationship defined through experimental investigation. The structure facilitates an attachment of a plug cap to the spark plug.

Spark plug

A ground electrode has one end portion fixed to a metal housing, a bent portion provided at an intermediate portion thereof, and the other end portion positioned in a confronting relationship with a center electrode to form a spark discharge gap. The ground electrode contains either Ni or Fe as a main component and at least one additive selected from the group consisting of Cr and Al. A cross-sectional area S of the ground electrode is not less than 2 mmand not greater than 3 mm. An average value D of crystal grain diameters in a thickness direction is not less than 100 &#x3bc;m at least at the bent portion.

A spark plug according to the invention includes a metal shell that has a threaded portion with an outer diameter of 10 mm or less, or equal to 12 mm, an insulator, a center electrode, and a ground electrode. The spark plug has an improved structure in which an end portion of the insulator tapers toward an end thereof that protrudes from an end of the metal shell, and dimensional parameters, including a space G of the spark gap in the spark plug, a taper degree of the end portion of the insulator that is represented by an outer diameter difference (D&#x2212;D) in the end portion, and a size Tof the air pocket formed in the spark plug, each have an effective range determined based on the experimental investigation results from the inventors. The structure ensures high insulation properties and high ignition capability of the spark plug.

Spark plug with high insulation properties and high capability to ignite air-fuel mixture

A spark plug is disclosed as including a metal shellformed with first and second boresand a stepped sectionbetween the first and second bores, and a porcelain insulatorhaving a largest-diameter section, which is accommodated in the first bore and a small-diameter sectionaccommodated in the second bore. The first and second bores of the metal shell have a dimensional relationship, lying in a value equal to or less than 1.8 mm, which is expressed as (D&#x2212;D)/2 where Drepresents an inner diameter of the first bore of the metal shell and Drepresents an inner diameter of the second bore of the metal shell.

A spark plug includes a metal shell, an insulator, a center electrode, and a ground electrode. The metal shell has a threaded portion with an outer diameter of equal to or less than 10 mm, or equal to 12 mm for installing the spark plug in an internal combustion engine. The dimensional parameters in the structure of the spark plug, such as a clearance X between the center electrode and the insulator, a surface-creeping distance Y outside the metal shell, a protruding length Yof the insulator, an air pocket size Z, and a surface-creeping distance W inside the metal shell satisfy the dimensional relationships defined through experimental investigation in the invention. The structure ensures a high capability of the spark plug to ignite the air-fuel mixture even when the insulator thereof is fouled with carbon.

Growing community of inventors

Aichi-ken, Japan

Keiji Kanao