摘要:
In a spark plug having a noble metal layer disposed on a firing end of an electrode, the noble metal layer being laser welded to the firing end of the electrode, and subsequently heat treated to increase a crystallized granulation particle size of the noble metal layer.
摘要:
A spark plug 100 comprised of a metal shell 1, an insulator 2, a center electrode 3 and a ground electrode 4. A rear-end face of the ground electrode 4 is welded to a front-end face of the metal shell 1, and a bent portion 5 located at the intermediated position in the longitudinal direction is bent toward the center of the spark plug 100. The ground electrode 4 assumes a circular-shape with a diameter of 2 mm or less whereby an inflow of an air-fuel mixture is not disturbed even when the air-fuel mixture directly flows into a back face of the ground electrode 4. The ground electrode 4 is comprised of an outer layer 4A made of a nickel alloy and an inner layer 4B made of pure copper with an excellent thermal conductivity, in which a ratio of a cross-sectional area of the inner layer 4B to the entire cross-sectional area of the ground electrode 4 is 10% or more to 35% or less. Thus, the spark plug 100 which is excellent in heat sinking ability and can prevent a spring back phenomenon due to a difference in a coefficient of thermal expansion.
摘要:
A spark plug comprising: a center electrode extending in a direction of an axis of said spark plug; a cylindrical insulator which has a shaft hole, and which holds said center electrode in said shaft hole in a state where a tip end of said center electrode is projected from a tip end face of said insulator; a metal shell which holds said insulator; and a ground electrode in which one end is joined to a tip end face of said metal shell, and which extends from said one end toward another end, wherein said ground electrode has an inner side face which faces said center electrode, and an outer side face which is a back face with respect to said inner side face, said outer side face is formed as an arcuately curved face when viewed from a side of said another end in an extending direction of said ground electrode, and a columnar noble metal tip is joined to said inner side face.
摘要:
An ammonium gas sensor is provided. The ammonium gas sensor includes: a solid electrolyte layer having oxygen ion conductivity; a detection electrode formed on one surface of the solid electrolyte layer; a reference electrode that is a counter electrode of the detection electrode; a selective reaction layer covering the detection electrode; and a protection layer covering the selective reaction layer and made from a porous material; wherein the detection electrode includes a noble metal as a main component; the selective reaction layer includes oxide represented by AxMyOz as a main component, where A is one or more kind(s) of metal, M is vanadium, tungsten, or molybdenum and x, y, z are atomic ratios; and the protection layer includes the oxide that is in an amount smaller than a content of the oxide included in the selective reaction layer.
摘要:
A method for producing a spark plug, the spark plug including: a center electrode; an insulator which holds the center electrode therein in a state where a tip end portion of the center electrode protrudes therefrom; a metal shell which holds the insulator therein; a ground electrode which is fixed to the metal shell, the ground electrode having an inner side face having a width that is smaller as it advances toward a tip end side, in a portion of the inner side face positioned between a pair of tapered faces; and a discharge portion which is bonded to the inner side face of the ground electrode by laser welding so as to attain a diameter of 0.8 mm or less and a height of 0.5 mm or more, a discharge gap being formed between the discharge portion and the tip end portion of said center electrode, the method including: forming the tapered faces before the discharge portion is laser-welded to the inner side face.
摘要:
In a glow plug and a spark plug, the surface of a main metal shell is coated with a chromate film in which the quantity of trivalent chrome is 95 wt % or more of the contained chrome components and which has a thickness of 0.2 μm to 0.5 μm.
摘要:
An object of the invention is to provide a higher-durability spark plug provided with a center electrode and a side electrode to form a spark discharge gap between the center electrode and the side electrode, at least one of the center electrode and the side electrode including a precious metal member facing the spark discharge gap, in which a sweating phenomenon of the precious metal member can be suppressed while spark abrasion, oxidation abrasion and abnormal abrasion of the precious metal member can be suppressed. In the invention, the spark plug (100) comprises a center electrode (3), and a side electrode (4) located on one side of the center electrode (3) so that a spark discharge gap (G) is formed between the center electrode (3) and the side electrode (4). The center electrode (3) and the side electrode (4) include first and second precious metal tips (33) and (43) respectively. The first and second precious metal tips (33) and (43) face the spark discharge gap (G) so that the spark discharge gap (G) is formed. The precious metal tips (33) and so on contain Ir as a main component, 0.3 mass % to 43 mass % of Rh, 5.2 mass % to 41 mass % of Ru, and 0.4 mass % to 19 mass % of Ni.
摘要:
A noble-metal chip 30, 90 joined to at least either a center electrode or a ground electrode, the center and ground electrodes forming a spark discharge gap, and having a circumferential edge of its facing end surface 31, 91 removed so as to form an edge-removed portion 32, 92. The edge-removal length is 0.01 mm or more and a ratio of the edge-removal length to a radius of the noble-metal chip is less than 0.3. The noble-metal chip is made of iridium or an alloy that contains iridium in an amount of 70% by weight or more, and crystal grains constituting the noble-metal chip 30, 90 extends in the axial direction. Also disclosed is a method for manufacturing the spark plug.
摘要:
A spark plug of the present invention is made of an Ir alloy including a specific amount of (1) Rh, (2) Pt, or (3) Rh and Pt or Rh and Ru. The spark plug comprises tips for a center electrode and for a ground electrode that are each 0.6 to 1.8 mm in diameter and 0.2 to 0.7 mm in thickness and for an interlayer made of an Ir alloy including Ni of 40 mass % that has a diameter slightly larger or smaller than that of each tip for the center electrode and for the ground electrode and has a thickness of 0.1 to 0.6 mm. These tips can be manufactured according to the powder processing method, the dissolution method, and so on. The tip for the center electrode is joined to the end surface of the basic body of the center electrode, which is made of a Ni alloy (Inconel 600), according to laser welding. The tip for the interlayer and the tip for the ground electrode are brought into contact with a predetermined position of the ground electrode, and are joined while being pressed according to electric resistance welding. Other parts, such as an insulator and main metal fittings, are each made of general materials and have a general structure. This spark plug is excellent in resistance to lead corrosion, and the tip for the ground electrode is prevented from peeling and falling off from the base because of a thermal expansion difference.
摘要:
A spark plug includes a center electrode, an insulator provided outside the center electrode, a metallic shell provided outside the insulator, a ground electrode disposed to oppose the center electrode, and a spark discharge portion fixed on at least one of the center electrode and the ground electrode for defining a spark discharge gap. The spark discharge portion is formed from an alloy containing Ir as a main component, Rh in an amount of 0.2 to 10 wt. %, and Pt in an amount not greater than 10 wt. %. The ratio WPt/WRh of the Pt content to the Rh content falls within the range of 0.1-1.5.