摘要:
A spark plug including a center electrode and a ground electrode. A center electrode noble metal tip is joined to a leading end portion of a center electrode, and a ground electrode noble metal tip is joined to a center-electrode-side side surface of the ground electrode. A distal end portion of the ground electrode noble metal tip protrudes from a distal-end surface of the ground electrode by 0.1 mm to 1.5 mm. A center-electrode-side side surface of the ground electrode noble metal tip projects from a center-electrode-side side surface by 0.15 mm to 0.6 mm. The ground electrode includes chamfered portions. Thickness lengths and widthwise lengths of the respective chamfered portions achieved within a cross section perpendicular to a center axis of the ground electrode are set to 0.2 mm or more.
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:
In a spark plug in use for an internal combustion engine, a ground electrode is secured to a front end of the metal shell so that a front end surface of the ground electrode faces an elevational side of a front end of the center electrode to cause semi-creeping spark discharges therebetween along a front end surface of the insulator. A front end portion of the center electrode has an electrode base in the axial bore and an electrode front defined diametrically smaller than the electrode base by way of a diameter-variable portion. A diametrical difference between an initial point of the diameter-variable portion of the center electrode and the axial bore of the insulator is 1 mm or less, and the initial point of the diameter-variable portion is retracted by 0.0 mm-1.0 mm from the front end surface of the insulator.
摘要:
A slit yarn wherein both side parts of the slit yarn are folded one or more times, and the folded width is substantially uniform along the direction of length of the yarn. In this slit yarn, when the width is measured at 20 or more points at intervals of 0.5 m, and the fluctuation coefficient X shown in the following Equation (1) is calculated on the basis of the average value W(avg) and the standard deviation W(σ), this X is (for example) approximately 4% or less. Furthermore, in the slit yarn of the present invention, the abovementioned folded parts are ordinarily shape-set. X(%)=W(σ)/W(avg)×100 (1)
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:
In an internal combustion engine, an engine control device 40 judges based on a cooling water temperature of an engine in what state the engine is. When judged that the engine is in a cold state, the engine control device 40 produces an ignition signal to feed it to an igniter 6b so as to spark spark plugs 7 which are individually placed in cylinders at an exhaust stroke or expansion stroke.
摘要:
A spark plug including: a center electrode as defined herein; a substantially cylindrical insulator as defined herein; a cylindrical metal shell as defined herein; and a ground electrode as defined herein, wherein a spark discharge gap is provided between the leading end portion of the center electrode and the leading end portion of the ground electrode, and the ground electrode has a bulging curved face on a side opposite to a side in which the center electrode is provided, and a maximum of width of the ground electrode within a range of ±1 mm from a center point of the spark discharge gap in the axial direction, as viewed in a direction where the center electrode and the ground electrode overlap, is 105% or less of a width of an ordinary portion having a substantially constant width.
摘要:
A slit yarn wherein both side parts of the slit yarn are folded one or more times, and the folded width is substantially uniform along the direction of length of the yarn. In this slit yarn, when the width is measured at 20 or more points at intervals of 0.5 m, and the fluctuation coefficient X shown in the following Equation (1) is calculated on the basis of the average value W(avg) and the standard deviation W(σ), this X is (for example) approximately 4% or less. Furthermore, in the slit yarn of the present invention, the abovementioned folded parts are ordinarily shape-set. X(%)=W(σ)/W(avg)×100 (1)
摘要:
A spark plug including: a center electrode as defined herein; a substantially cylindrical insulator as defined herein; a cylindrical metal shell as defined herein; and a ground electrode as defined herein, wherein a spark discharge gap is provided between the leading end portion of the center electrode and the leading end portion of the ground electrode, and the ground electrode has a bulging curved face on a side opposite to a side in which the center electrode is provided, and a maximum of width of the ground electrode within a range of ±1 mm from a center point of the spark discharge gap in the axial direction, as viewed in a direction where the center electrode and the ground electrode overlap, is 105% or less of a width of an ordinary portion having a substantially constant width.
摘要:
A method of bonding an abrasive solid mass to a desired member with an adhesive, wherein the abrasive solid mass has a porous abrasive structure in which a multiplicity of abrasive grains are held together by a bonding agent. The method includes a sealing-film forming step of forming a sealing film on a surface of the abrasive solid mass, for preventing the adhesive from penetrating into pores formed in the porous abrasive structure.