Abstract: An amorphous hard carbon film comprising a first amorphous carbon layer substantially consists only of carbon formed on a substrate surface and a second amorphous carbon layer substantially consists only of carbon formed on the surface of the first amorphous carbon layer, wherein the transmission electron microscope image of the first amorphous carbon layer is brighter than that of the second amorphous carbon layer when the cross section is observed.

Abstract: A method of manufacturing an oil ring is disclosed. The oil ring includes an annular oil ring body having a pair of rail portions at its axially upper and lower portions and butt ends, and a coil expander assembled in the inner periphery of the oil ring body. A number of oil ring bodies and annular spacers having a smaller diameter than the oil ring bodies are stacked, and then aligned and retained using a jig such that an outer periphery of the oil ring bodies becomes a circle. The aligned oil ring bodies are rotated and a flat region that is substantially level with respect to the outer peripheral sliding surface of the plurality of oil ring bodies is formed. Curved regions extending on both sides of that flat region are formed using a buff or an elastic grindstone.

Abstract: A fuel cell separator having excellent corrosion resistance, electric conductivity and durability comprising a substrate made of austenitic stainless steel, and a nitride layer formed on a surface of the substrate in contact with an oxygen electrode or a current collector on the oxygen electrode side, the nitride layer comprising a solid solution compound phase composed of an Fe4N crystal, in which part of Fe is substituted by at least Cr and Ni.

Abstract: It is a technical common knowledge that a chaplet used in casting of a hollow casting is fusion-bonded with the melt and is incorporated into the casting. However, the adhesion between the chaplet and the casting body is not necessarily satisfactory, thereby incurring the strength reduction of a thin-wall hollow casting. A core for a thin-wall hollow casting according to the present invention is provided with a chaplet mounted thereon. The chaplet has arcuate portion 2 with a gap 5 and a plurality of projections 4 from an outer peripheral of the arcuate portion and is in contact with an inner wall 7 of a mold. The entire arcuate portion of the chaplet is included in a groove 6 formed around an outer peripheral portion of the core body. Only the projections 4 of the chaplet protrude from the core body, when the chaplet is inserted in the groove.

Abstract: A plurality of first inclined faces (51) are provided on a side face of a seal ring (5) to be distanced away from each other. The first inclined face (51) opens to an inner circumferential face (23) and the side face of the seal ring (5). A column portion (54) is provided between adjacent first inclined faces (51). Portions at both ends of the first inclined face (51) serve as converging portions (52) that are conical smoothly-inclined faces, each converging to the adjacent column portion (54). On the column portion (54), the second inclined face (57) is formed.

Abstract: A method and a device for identifying an upper surface and a lower surface of a component having asymmetric upper and lower outer shapes are provided. In particular, a method and a device for identifying orientation of an item that hardly allows visual identification of the upper and lower surface. A disk-like, cylindrical, or annular component having asymmetric upper and lower outer shapes is placed on a reference surface having a reference block, an outer peripheral part of the component on the reference surface is brought into contact with the reference block, and identification of the upper and lower surface of the component is achieved in an inline system based on a gap created between the outer peripheral part of the component and the reference block, using a light source lighting device and a detection camera arranged across the reference block.

Abstract: An internal combustion engine includes: a cylinder block having one or more cylinders, a cylinder liner in a tubular shape disposed inside the cylinder; a piston reciprocating inside the cylinder liner and having a top land portion formed of an outer periphery of the piston sandwiched between a piston head and an uppermost ring groove; and a liner installation ring forming, inside the cylinder, a circular step portion protruding toward the inner periphery of the cylinder liner. The liner installation ring is disposed in the cylinder block or the cylinder liner in such a manner that the bottom face of the liner installation ring face to the uppermost portion of the cylinder liner. The liner installation ring is disposed at a position in accordance with the upper end position of the top land portion when the piston reaches a top dead center. The liner installation ring is set to protrude from the inner periphery of the cylinder liner in an inward direction at a length of 0.05 mm or more to 0.5 mm less.

Abstract: A method and a device for identifying an upper surface and a lower surface of a component having asymmetric upper and lower outer shapes are provided. The components include, for example, disk-like, cylindrical, or annular components, more specifically engine parts having an orientation such as piston rings. In particular, a method and a device for identifying orientation of an item that hardly allows visual identification of the upper and lower surface. A disk-like, cylindrical, or annular component having asymmetric upper and lower outer shapes is placed on a reference surface having a reference block, an outer peripheral part of the component on the reference surface is brought into contact with the reference block, and identification of the upper and lower surface of the component is achieved in an inline system based on a gap created between the outer peripheral part of the component and the reference block, using a light source lighting device and a detection camera arranged across the reference block.

Abstract: A fuel cell separator having excellent corrosion resistance, electric conductivity and durability comprising a substrate made of austenitic stainless steel, and a nitride layer formed on a surface of the substrate in contact with an oxygen electrode or a current collector on the oxygen electrode side, the nitride layer comprising a solid solution compound phase composed of an Fe4N crystal, in which part of Fe is substituted by at least Cr and Ni.

Abstract: A composite chromium plating film containing hard particles in network-shaped microcracks, a surface-occupying ratio of the microcracks being 10 to 20% by area, a distribution density of the microcracks being 1,200 to 2,500/cm, and the amount of the above hard particles being 1 to 15% by mass per 100% by mass of the above entire plating film. This composite chromium plating film has excellent wear resistance and scuffing resistance with small attacking ability to a mating member.

Abstract: In mounting a combined oil control ring in a ring groove formed in a piston, the combined oil control ring is mounted in a form that an opening between but ends of an oil ring body is widened. In such an operation, it is likely that a coil expander falls off the oil ring body thus making the mounting operation cumbersome. To overcome such a drawback, a relationship L1<L2 is established. Here L1 means a axial distance between open peripheries of the groove portion and L2 means a maximum axial distance between peripheries of the groove portion.

Abstract: A top ring has gas seal and oil control functions realizing approximately the same amount of oil consumption and blow-by gas as realized by three rings. A piston assembly includes a piston body having a top land portion and a ring groove on its periphery, and a piston ring having a U-shaped cross section including upper and lower leg portions and a base portion connecting the leg portions, and attached to the top land portion. Axial length from boundary of the base portion of the piston ring and the upper leg portion to a lower surface of the lower leg portion is larger than that from an upper surface of the top land portion to lower surface of the ring groove fitting the lower leg portion. Alternatively, axial grooves are on a thrust side of the top land portion, or a V-shaped annular groove is in a second land portion.

Abstract: The piston ring of the present invention comprises a thermal spray coating comprising chromium carbide particles having an average particle size of 5 ?m or less, and a matrix metal composed of a Ni—Cr alloy or a Ni—Cr alloy and Ni at least on an outer peripheral surface, said thermal spray coating having an average pore diameter of 10 ?m or less and a porosity of 8% or less by volume. A piston ring having excellent wear resistance, scuffing resistance and peeling resistance with little attackability on a mating member is obtained by forming a homogeneous thermal spray coating having a fine microstructure.

Abstract: A thermal spray coated piston ring having improved initial running-in propery, and having scuffing resistance and wear resistance is provided. The spray coating film (3) of the piston ring (1) contains from 2 to 40 mass % of Sn and from 5 to 50 mass % of graphite, and if necessary, P, Sb, Co, Be, Cr, Mn, Si, Cd, Zn, Fe, Ni and/or Pb, the balance essentially consisting of Cu.

Abstract: An internal combustion engine includes: a cylinder block having one or more cylinders, a cylinder liner in a tubular shape disposed inside the cylinder; a piston reciprocating inside the cylinder liner and having a top land portion formed of an outer periphery of the piston sandwiched between a piston head and an uppermost ring groove; and a liner installation ring forming, inside the cylinder, a circular step portion protruding toward the inner periphery of the cylinder liner. The liner installation ring is disposed in the cylinder block or the cylinder liner in such a manner that the bottom face of the liner installation ring face to the uppermost portion of the cylinder liner. The liner installation ring is disposed at a position in accordance with the upper end position of the top land portion when the piston reaches a top dead center. The liner installation ring is set to protrude from the inner periphery of the cylinder liner in an inward direction at a length of 0.05 mm or more to 0.5 mm less.

Abstract: In a corner portion (2) defined between an outer peripheral surface (4) and a lower-side surface (3) of a steel piston ring (1), a groove (5, 6) having either an approximately quadrangular shape with a length of one side of 0.05 to 0.4 mm or an approximately quarter circular shape having a radius of 0.05 to 0.4 mm is formed. A sharp edge (9) formed by the groove (5, 6) performs an oil scraping function and the groove (5, 6) works to reduce an oil pressure of a second land or a third land clearance between the cylinder bore and the piston.

Abstract: A valve lifter, in which an amorphous hard carbon film is coated at least on the surface that slides against a cam, is characterized in that the surface of a base material (substrate) has an arithmetic mean roughness of Ra 0.01 to 0.03 micrometers, and the maximum length of the scratch on the base surface is made to be equal to or shorter than 250 micrometers.

Abstract: A manufacturing method of a piston ring is developed, wherein the method provides a countermeasure for wear of butt ends of the ion plating film coated piston ring and a countermeasure for breakage of the piston ring and the piston ring manufactured at a low cost. A thickness of the film (2) in the vicinity of butt ends (7) of a piston ring (1) is made greater than the thickness of the film (2) at other outer peripheral surface. Piston ring blanks (5) are rotated around their own axes toward an evaporation source (4) and a speed is lowered when the butt ends (7) face the evaporation source (4).

Abstract: A three-piece combined oil-control ring comprises a pair of upper and lower side rails 222 in the axial direction and a spacer expander 224. The spacer expander is located between the side rails 222, and pushes the side rails from their inner peripheral side to generates the tension of the side rails 222. The ears of the spacer expander made of austenitic stainless steel in contact with inner peripheral surfaces of the side rails, are subjected to gas-nitriding at a temperature of 470° C. or higher to form a 10 to 60 ?m thick gas-nitriding surface-layer comprising a phase having peaks at 2?=40° and 2?=46° by Cu—K ? X-ray diffraction. In addition or alternatively, a resin coating film (31) is formed on at least surfaces of the spacer expander (7) faced to the side surfaces of the side rails or on at least surfaces of the side rails (5,6) faced to the spacer expander (7).

Abstract: The piston ring of the present invention comprises a thermal spray coating comprising chromium carbide particles having an average particle size of 5 ?m or less, and a matrix metal composed of a Ni—Cr alloy or a Ni—Cr alloy and Ni at least on an outer peripheral surface, said thermal spray coating having an average pore diameter of 10 ?m or less and a porosity of 8% or less by volume. A piston ring having excellent wear resistance, scuffing resistance and peeling resistance with little attackability on a mating member is obtained by forming a homogeneous thermal spray coating having a fine microstructure.