Abstract: A combination oil ring includes a pair of upper and lower side rails and a spacer expander arranged there between, the spacer expander including a plurality of upper pieces and lower pieces alternately arranged in a circumferential direction with the pieces axially and circumferentially apart from each other, a coupling piece coupling pieces adjacent to each other, and flange portions formed standing at inner circumferential-side end portions of the upper pieces and the lower pieces so as to press the side rails, and a through hole being formed in the flange portions, wherein side rail support portions that project axially are formed at portions in the circumferential direction of outer circumferential-side end portions of the upper pieces and the lower pieces.

Abstract: The valve seat includes an iron-based sintered alloy subjected to oxidation treatment, which is obtained by subjecting an iron-based sintered alloy including: 4 mass % to 15 mass % of Co particles; and hard particles each containing at least one compound of an intermetallic compound, a carbide, a silicide, a nitride, or a boride that has one or more kinds of elements selected from group 4a to 6a elements in a periodic table, and having a hardness of from 600 HV to 1,600 HV to oxidation treatment, and which has an oxide mainly including triiron tetraoxide (Fe3O4) and cobalt oxide (CoO) formed on a surface and in an interior of the iron-based sintered alloy. The iron-based sintered alloy subjected to oxidation treatment has an area ratio of the oxide of from 5% to 25% in a cross section thereof in a state prior to installation on the cylinder head.

Abstract: A combination oil ring includes a pair of upper and lower side rails and a spacer expander arranged there between, the spacer expander including a plurality of upper pieces and lower pieces alternately arranged in a circumferential direction with the pieces axially and circumferentially apart from each other, a coupling piece coupling pieces adjacent to each other, and flange portions formed standing at inner circumferential-side end portions of the upper pieces and the lower pieces so as to press the side rails, and a through hole being formed in the flange portions, wherein side rail support portions that project axially are formed at portions in the circumferential direction of outer circumferential-side end portions of the upper pieces and the lower pieces.

Abstract: In a combination oil ring, when a line passing through a center of a segment width is a first intermediate line, a length of a line segment between a position on an engine combustion chamber side and a position on a side distant from the engine combustion chamber on a contour curve at a position at a distance of 3 ?m from an outer peripheral vertex toward an inner peripheral side in a segment radial direction is L, and an intermediate line of the line segment L is a second intermediate line, the second intermediate line is located on the side more distant from the engine combustion chamber than the first intermediate line, and the outer periphery vertex of the segment is located on the second intermediate line or on the side more distant from the engine combustion chamber than the second intermediate line.

Abstract: A combination oil ring includes a pair of upper and lower side rails and a spacer expander arranged therebetween, the spacer expander including a plurality of upper pieces and lower pieces alternately arranged in a circumferential direction with the pieces axially and circumferentially apart from each other, a coupling piece coupling pieces adjacent to each other, and flange portions formed standing at inner circumferential-side end portions of the upper pieces and the lower pieces so as to press the side rails, and a through hole being formed in the flange portions, wherein side rail support portions that project axially are formed at portions in the circumferential direction of outer circumferential-side end portions of the upper pieces and the lower pieces.

Abstract: Provided is a valve seat having excellent strength and wear resistance. In a valve seat using an iron-based sintered alloy, an oxide mains composed of triiron tetroxide is formed by oxidation treatment on the surface and interior of the iron-based sintered alloy, and the average area ratio of the oxide mainly composed of triiron tetroxide in a cross section of the iron-based, sintered alloy in the state prior to installation on a cylinder head is 5 to 20%. Preferably, the iron-based sintered alloy contains hard particles formed from at least one compound of carbides, silicides, nitrides, borides, and intermetallic compounds containing one or more elements selected from groups 4a to 6a of the periodic table, and the average area ratio of the hard particles in the cross section of the iron-based sintered alloy in the state prior to installation on a cylinder head is 5 to 45%.

Abstract: The valve seat includes an iron-based sintered alloy subjected to oxidation treatment, which is obtained by subjecting an iron-based sintered alloy including: 4 mass % to 15 mass % of Co particles; and hard particles each containing at least one compound of an intermetallic compound, a carbide, a silicide, a nitride, or a boride that has one or more kinds of elements selected from group 4a to 6a elements in a periodic table, and having a hardness of from 600 HV to 1,600 HV to oxidation treatment, and which has an oxide mainly including triiron tetraoxide (Fe3O4) and cobalt oxide (CoO) formed on a surface and in an interior of the iron-based sintered alloy. The iron-based sintered alloy subjected to oxidation treatment has an area ratio of the oxide of from 5% to 25% in a cross section thereof in a state prior to installation on the cylinder head.

Abstract: A combination oil ring prevented from freeze up of the side rails and spacer expander, that is, a combination oil ring of the present invention provided with a top and bottom pair of side rails 11 and 12 and a spacer expander 13 having large numbers of top pieces 14 and bottom pieces arranged separated in the axial direction and circumferential direction and alternating in the circumferential direction, connecting pieces 16 connecting adjoining top pieces 14 and bottom pieces 15, and ear parts 17 and 18 formed rising up at the inner circumference side ends of the top pieces 14 and bottom pieces 15 for pushing against the side rails 11 and 12, in which combination oil ring 10, grooves 19 and 20 are formed in at least one surfaces of top surfaces of the top pieces 14 and bottom surfaces of the bottom pieces 15, and through holes 17a and 18a by which the grooves 19 and 20 are communicated are formed in the ear parts 17 and 18.

Abstract: Provided is a high-toughness coating film having excellent wear resistance, in particular, resistance to cracking and peeling. A high-toughness coating film (2) includes a composition containing a mixture of metallic chromium, in which nitrogen is dissolved, and Cr2N. A content of the nitrogen in the high-toughness coating film is 2.0 to 8.5 mass %, and IP, which is expressed by total of each diffraction peak intensity of Cr2N/(total of each diffraction peak intensity of metallic chromium+total of each diffraction peak intensity of Cr2N), is 3 to 40% when 2? is in a range of 30° to 90°, where ? is an incident angle in X-ray diffraction of the high-toughness coating film.

Abstract: A piston ring which is provided with a carbon-based coating which has a low friction property and wear resistance, that is, a piston ring which has a carbon-based coating formed over its sliding surface, in which piston ring, the coating is a multilayer coating comprised of two types of layers having different hardnesses laminated in at least two layers, a hardness difference between the two types of layers is 500 to 1700 HV, a high hardness layer has the same or greater thickness than a low hardness layer, and the coating as a whole has a thickness of 5.0 ?m or more. The high hardness layer has a thickness of 5 to 90 nm. The surface on which the coating is formed has a base material roughness of 1.0 ?mRz or less.

Abstract: A cylinder liner for insert casting which is excellent in heat conductivity with a cylinder block is provided, the cylinder liner for insert casting of the present invention comprising a cylinder liner for insert casting 2 which is formed with projections 5 with heights of 0.3 to 1.2 mm and undercut parts 6 in a ratio of 20 to 80/cm2 on an outer circumferential surface 4 over which, in turn, a thermally sprayed layer 7 is covered, wherein the thermally sprayed layer 7 is comprised of a ferrous material and wherein a ratio of a surface area of a thermally sprayed layer 7 surface at a certain region on the outer circumferential surface 4 of the liner with an area of the region is 12 to 23. The thermally sprayed layer preferably has a thickness of 0.01 to 0.2 mm. The thermally sprayed layer is preferably formed using a wire shaped thermal spraying material.

Abstract: Provided is a valve seat having excellent strength and wear resistance. In a valve seat using an iron-based sintered alloy, an oxide mains composed of triiron tetroxide is formed by oxidation treatment on the surface and interior of the iron-based sintered alloy, and the average area ratio of the oxide mainly composed of triiron tetroxide in a cross section of the iron-based, sintered alloy in the state prior to installation on a cylinder head is 5 to 20%. Preferably, the iron-based sintered alloy contains hard particles formed from at least one compound of carbides, silicides, nitrides, borides, and intermetallic compounds containing one or more elements selected from groups 4a to 6a of the periodic table, and the average area ratio of the hard particles in the cross section of the iron-based sintered alloy in the state prior to installation on a cylinder head is 5 to 45%.

Abstract: A brake drum which can improve the drag strength, strength and rigidity in the diametrical direction, joint strength, and heat radiating ability, that is, a brake drum which is used for a drum brake, wherein the drum has a plurality of the projections at the outer circumferential surface, the plurality of the projections are formed at the outer circumferential surface as a whole when casting a brake drum, and at least part of the projections have thin-waisted shapes. A height of the projections is 0.3 to 5.0 mm, while the number of projections is 5 to 100/cm2. The brake drum is produced by centrifugal casting.

Abstract: The present invention prevents anchoring between a space expander and a side rail of a combination oil ring.

Abstract: A support member with excellent contact with the member to which the support member is attached, that is, a metal support member which supports a shaft directly or through a bearing and which has a plurality of the projections at its outer circumferential surface, wherein the plurality of the projections are formed at the outer circumferential surface as a whole at the time of casting of the support member and wherein at least part of the projections have thin-waisted shapes or a plastic support member which supports a shaft directly or through a bearing and which has a plurality of the projections at its outer circumferential surface, wherein the plurality of the projections are formed at the outer circumferential surface as a whole at the time of molding of the support member and wherein at least part of the projections have thin-waisted shapes.

Abstract: A support member with excellent contact with the member to which the support member is attached, that is, a metal support member which supports a shaft directly or through a bearing and which has a plurality of the projections at its outer circumferential surface, wherein the plurality of the projections are formed at the outer circumferential surface as a whole at the time of casting of the support member and wherein at least part of the projections have thin-waisted shapes or a plastic support member which supports a shaft directly or through a bearing and which has a plurality of the projections at its outer circumferential surface, wherein the plurality of the projections are formed at the outer circumferential surface as a whole at the time of molding of the support member and wherein at least part of the projections have thin-waisted shapes.

Abstract: A cooling system for a piston of an internal combustion engine includes a cooling channel (34) designed as an oil passage embedded in the piston and arranged adjacent to a top ring groove, and an oil supply portion (8) that supplies oil to the cooling channel. An amount of oil supplied from the oil supply portion to the cooling channel is made larger when an amount of heat generated in a combustion chamber is large than when the amount of heat generated in the combustion chamber is small.

Abstract: To provide a piston ring tension measurement apparatus which can stably measure a piston ring for suitable tension, the piston ring tension measurement apparatus of the present invention comprises: a table 1 which supports a measured piston ring 5; a first band 3 which is to be wound around an outer circumferential part of the measured piston ring 5 and which is fastened at its two end sides by fasteners 4 and 6; a second band 8 which is to be wound around an outer circumferential part of the measured piston ring 5 where the first band 3 is not wound; a fastener 11 for fastening one end side of the second band 8; a tension imparting means 14, 15, and 16 for making the second band 8 move in a direction squeezing the measured piston ring 5; and a load cell 10 which measures a tension which is imparted to the second band 8.

Abstract: A piston ring which is provided with a carbon-based coating which has a low friction property and wear resistance, that is, a piston ring which has a carbon-based coating formed over its sliding surface, in which piston ring, the coating is a multilayer coating comprised of two types of layers having different hardnesses laminated in at least two layers, a hardness difference between the two types of layers is 500 to 1700 HV, a high hardness layer has the same or greater thickness than a low hardness layer, and the coating as a whole has a thickness of 5.0 ?m or more. The high hardness layer has a thickness of 5 to 90 nm. The surface on which the coating is formed has a base material roughness of 1.0 ?mRz or less.

Abstract: A brake drum which can improve the drag strength, strength and rigidity in the diametrical direction, joint strength, and heat radiating ability, that is, a brake drum which is used for a drum brake, wherein the drum has a plurality of the projections at the outer circumferential surface, the plurality of the projections are formed at the outer circumferential surface as a whole when casting a brake drum, and at least part of the projections have thin-waisted shapes. A height of the projections is 0.3 to 5.0 mm, while the number of projections is 5 to 100/cm2. The brake drum is produced by centrifugal casting.