Denso Corporation

Satoru Kadowaki

Yasuhiro Mizutani

Tsunenobu Hori

Kazutaka Suzuki

Ken Hanashi

Hidekazu Hattori

Naoyuki Kawazoe

Tooru Matsumoto

Hiroya Ishiguro

Kenka Tsubota

Hirotaka Aida

Yasutake Ishino

Shoichiro Emmei

Toshikazu Shimizu

Fuminori Nakashima

Seiichiro Suzuki

Yoshinobu Takeuchi

A spark plug has a cylindrical housing case, a cylindrical glass insulator, a center electrode, and an earth electrode fixed to the cylindrical housing case. The earth electrode has a projected part which is projected toward the center electrode. The projected part has a facing surface which faces the center electrode and is most close to the center electrode in a spark discharge gap. This gap is formed between the center electrode and the earth electrode. The facing surface is covered with a plating layer. A base material, with which the earth electrode is made, is exposed on a side surface of the projected part around the facing surface of the projected part. The base material of the earth electrode is made of Ni alloy containing not less than 90 wt % Ni, and preferably, Ni within a range of 90 wt % to 98 wt %.

Spark plug of internal combustion engine having an earth electrode having an exposed side surface on a projecting part

A spark plug for use in an internal combustion engine. The spark plug is equipped with a metal shell, a ground electrode joined to the metal shell, and a center electrode disposed in the metal shell. The ground electrode has a protrusion formed on a top end thereof. The metal shell and the ground electrode are covered with a plated layer which has a thickness of 2 &#x3bc;m to 18 &#x3bc;m, which minimizes the possibility of peeling of the plated layer from the ground electrode while keeping the plated layer as thin as possible without sacrificing the resistance to corrosion on the ground electrode.

Structure of spark plug designed to ensure improved productivity

A method of manufacturing a spark plug having an attachment fitting, an insulator, a center electrodeand an earth electrode. While fixed to attachment fitting, earth electrodehas a convex partformed by projecting a part of an opposed surfacetoward center electrode, and a concave partformed toward the opposed surfacefrom the earth electrode's back surface. The convex partis disposed so that the extension of a shaft center of the convex partpasses through the area in which the concave partis formed. The relation Ss is realized when an area of an opening of the concave partis set to Sand an average cross-section area of a cross section of the convex partperpendicular to an axial direction of the spark plug is set to s.

Method for manufacturing spark plug for internal-combustion engine

A spark plug for an internal-combustion engine comprises an attachment fitting, an insulator, a center electrodeand an earth electrode. While fixed to the attachment fitting, the earth electrodehas a convex partformed by projecting toward the center electrodea part of the opposed surface, which faces the center electrode, of the earth electrode and a concave partformed toward the opposed surfacefrom the earth electrode's back surfacewhich is the reverse side of the opposed surfaceof the earth electrode. The convex partis disposed so that the extension of a shaft center of the convex partmay pass through the area in which the concave partis formed. A relation of S&#x3e;=s is realized when an area of an opening of the concave partis set to Sand an average cross-section area of a cross section of the convex partperpendicular to an axial direction of the spark plug is set to s.

Spark plug for internal-combustion engine and method for manufacturing the same

A spark plug for an internal combustion engine is provided which includes a metal shell, a porcelain insulator, a center electrode, and a ground electrode. The center electrode is retained in the porcelain insulator to define a spark gap between itself and the ground electrode. The porcelain insulator has a nose made up of an upright portion and a tapered portion continuing from the upright portion toward a top end thereof. The tapered portion has a diameter decreasing toward the top end of the porcelain insulator. The upright portion has an outer wall extending substantially parallel to an inner wall of the metal shell, thereby inducing the formation of side sparks between the tapered portion and the metal shell before the insulation resistance between the center electrode and the metal shell drops, thereby giving a signal indicative of such an event to an operator.

Spark plug designed to minimize drop in insulation resistance

An image information displaying system comprises a transparent support, a hologram screen attached to the transparent support, a radiation unit for radiating image information on the hologram screen, a sensor for detecting the ambient condition within the viewing angle of the hologram screen, and a controller for controlling the radiation unit based on the signal from the sensor. The image information displaying system, which is inexpensive, long in service life, superior in eye-catching effect and low in running cost, consumes less energy and is controlled by a central control unit connected thereto through a communication line. The lower-end of the hologram screen is 80 to 180 cm from the floor level.

Image information displaying system and hologram display apparatus

Hologram and process for producing hologram

There is provided a hologram with excellent heat resistance. The hologram comprises a hologram film (10) in which a diffraction grating has been recorded, a substrate (11) situated on one side of the hologram film (10) via a bonding material (13), and a polymer film (12) situated on the other side of the hologram film (10) via a bonding material (13), wherein the thickness of the polymer film (12) is no greater than 100 .mu.m. Otherwise, the polymer film (12) is subjected to prior heat treatment. There is further provided a production process for holograms with minimal appearance defects. The process comprises preparing a photopolymer (210) coated onto a substrate (211) and affixing the photopolymer surface (301) onto a photographed object original (213), exposing it to laser light to converting it into a hologram (201), then releasing the hologram (201) from the photographed object original (213) to expose the hologram surface (302) and finally affixing a protective film (215) onto the hologram surface (302), such that the bonding strength A between the substrate (211) and the hologram (201) is greater than the bonding strength B between the hologram (201) and the protective film (215).

An apparatus synthesizes the image of a viewer and a second image into a synthesized image and displays the synthesized image. The apparatus is capable of aligning the line of sight of the viewer with the line of sight of the displayed image of the viewer and correctly reproducing colors on the synthesized image. The apparatus has a transparent hologram screen (15) on which a diffuser is recorded, a camera (25) for imaging a viewer (81) through the hologram screen, a synthesizer (28) for synthesizing the image of the viewer and a second image into a synthesized image, and a projector (11) for projecting signal light (31) containing the synthesized image onto the hologram screen. In place of the synthesizer, a display unit may be arranged behind the viewer. The hologram screen (15) may be combined with a mirror or a half-mirror.

Growing community of inventors

Mie-ken, Japan

Satoru Kadowaki