Abstract: The present invention provides a synchronizer ring excellent in strength and abrasion resisting property, used in a speed change gear. This synchronizer ring according to the invention is consisted of, by weight, C:0.2˜1.0%, Ni:1.0˜6.0%, Mo:0.6˜3.0%, Cu:1.0˜4.0% and the reminder Fe and inevitable impurities, and is made of Fe sintered alloy of which base composition comprises of mainly martonsite and bainite. And the base composition is preferably consisted of, by volume, martensite: 57˜80%, bainite: 17˜40%, austenite: 8% or less.

Abstract: According to an embodiment of the present invention, an improved sliding member is provided that has a sliding surface and a deposition layer formed on the sliding surface by means of an ion-plating method, where the deposition layer is composed mainly of CrN. The improvement comprises the CrN which has a preferred orientation of the plane {110}, where the deposition layer contains boron at a containing ratio not less than 0.05 and not more than 20 weight percent. According to another embodiment of the present invention, an improved sliding member is provided that has a sliding surface and a deposition layer formed on the sliding surface by means of an ion-plating method, where the deposition layer is composed mainly of CrN. The improvement comprises the CrN which has a preferred orientation of the plane {110}, where the deposition layer contains boron, at a containing ratio not less than 0.

Abstract: According to an embodiment of the present invention, an improved sliding member is provided that has a sliding surface and a deposition layer formed on the sliding surface by means of an ion-plating method, where the deposition layer is composed mainly of chrome nitride, including CrN. The improvement comprises the CrN of the chrome nitride which has a preferred orientation of the plane {100}, where the deposition layer contains boron at a containing ratio not less than 0.05 and not more than 20 weight percent. According to another embodiment of the present invention, an improved sliding member is provided that has a sliding surface and a deposition layer formed on the sliding surface by means of an ion-plating method, where the deposition layer is composed mainly of chrome nitride, including CrN. The improvement comprises the CrN of the chrome nitride which has a preferred orientation of the plane {100}, where the deposition layer contains boron, at a containing ratio not less than 0.

Abstract: A cylinder liner formed of a cast iron and having an inner peripheral surface subjected to honing which forms cross-hatching grooves on the surface. A resultant surface roughness ranges from 0.4 &mgr;mR3Z to 0.8 &mgr;mR3Z, and an open phase rate of graphite is not less than 80% at the inner peripheral surface.

Abstract: According to an aspect of the present invention, a piston ring for use in internal combustion engines is provided that is made of matensite-based stainless steel material containing C of not less than 0.4 and not more than 0.8 weight percent, Si of not less than 0.16 and not more than 0.4 weight percent, Mn of not less than 0.1 and not more than 0.4 weight percent, and Cr of not less than 2.0 and not more than 11.0 weight percent, where the steel material of the piston ring has mainly chromium carbide precipitated in the base texture thereof. The steel material of the first compression ring then has a nitriding layer formed thereon. According to another aspect of the present invention, a combination of compression rings, including a first compression ring 1 and a second compression ring 2, for use in internal combustion engines, is provided. The first compression ring 1 is made of martensite-based stainless steel material containing C of not less than 0.16 and not more than 1.

Abstract: The present invention is for producing stably a second pressure ring which both keeps a lubricant-scraping property and prevents the cylinder side from being longitudinally scratched. According to the invention, a second pressure ring made of iron without plating thereon, of which the outer peripheral sliding surface is downwardly divergent and slanted, is provided in which the lower end of the outer peripheral sliding surface is worked upwardly divergently so as to slant in a range of less than 0.15 mm in its axial direction. The junction between the outer peripheral sliding surface and the slanted worked portion is lapped cylindrically for finishing.

Abstract: A valve seat made of an iron base sintered alloy for internal combustion engines comprises of hard particles of hardness 700-1300 Hv dispersed by 3-20% by volume in a matrix phase comprising comprising of a 5-40% psarlite phase, a 20-60% fine carbide dispersed phase, and a 5-20% high alloy diffusd phase. The hard paricles are preferably selected from a group of Mo--Ni--Cr--Si--Co intermetallic compound particles, Cr--Mo--Co intermetallic compound particles, and Fe--Mo alloy particles. The iron base sinteed alloy is conpised of, by weight, C: 0.2-2.0%, Cr: 1.0-9.0%, Mo: 1.0-9.0%, Si: 0.1-1.0%, W: 1.0-50%, V: 0.2-3.0%, one or more Cu, Co and Ni of 0.5-10.0% in total, and the remainder substantial Fe.

Abstract: An object of the present invention is to provide a sliding member which is coated a film having superior wear resistance, superior scuffing resistance and a superior property not to increase an amount of wear on an opponent material (an opponent attacking property). This object can be achieved by providing a sliding member coated by a Cr--V--B--N alloy film 4 on an outer surface 3 thereof. In this case, it is preferable that the Cr--V--B--N alloy film is formed through a physical vapor deposition, particularly ion plating, vacuum deposition, or sputtering. Further, it is preferable that V (Vanadium) content is within the range of 0.1-30 wt. % and the boron (B) content is within the range of 0.05-20 wt. %.

Abstract: A valve seat for an internal combustion engine is provided with a base member in which cobalt-based hard particles are dispersed in a matrix of an iron-based alloy. The matrix of an iron-based alloy comprises (a) carbon in a range of 0.5-1.5 weight %, (b) chromium and/or vanadium in a range of 0.5-10.0 weight % in total and (c) iron as a remainder based on weight of the base member respectively. An amount of the cobalt-based hard particles is in a range of 26-50 weight % based on weight of the base member.

Abstract: A process for manufacturing a valve seat which is made of a sintered Fe alloy and comprises a main layer of a valve seat and a contacting layer, comprises the steps of preparing either a powdery Cu or a powdery material containing Cu in a powdery Fe alloy, forming a green compact body with two green compact body layers, one of which is the main layer and the other of which is the contacting layer, and which are made of the prepared powdery Fe alloy containing Cu, sintering the green compact body. According to the present invention, the infiltration of Cu from the main layer to the contacting layer of the valve seat is not generated as the conventional sintering process for manufacturing the valve seat comprising the two layers without the independent infiltration treatment of Cu, and, therefore, the valve seat obtained of the present invention has an high abrasion resistance without decreasing of a strength of the main layer.

Abstract: A method for producing dimensionally accurate rocker arms formed with a roller-receiving portion at one end. The method of the invention produces rocker arms which have a roller-receiving, fork-like portion at one end of the rocker arm body for receiving a roller contacting a cam. The method uses the steps of inserting between the opposed inner surfaces of the roller-receiving portion an insert jig having a parallel surface and a slant surface inclined inwardly of the jig by a predetermined angle from the parallel surface; placing a pressing jig on an outer surface of the roller-receiving portion, the surface of the pressing jig to be contacted with the outer surface of the roller-receiving portion having a parallel surface and a slant surface inclined outwardly of the pressing jig by a predetermined angle from the parallel surface; and applying pressure to the pressing jig to thereby press the inner surfaces of the roller-receiving portion against the surfaces of the insert jig.

Abstract: In an aspect of the present invention, a synchronizer ring, made of Fe-based sintered alloy, having an internal circumferential surface 101, is provided, the internal circumferential surface 101 being adapted to detachably engage in synchronized sliding with a rotating counterpart member thereof. At least the internal circumferential surface 101 is applied with aqueous vapor treatment to form iron oxide film thereon. In another aspect of the present invention, the iron oxide film has surface roughness not less than 20 .mu.mRz but not more than 55 .mu.mRz. In a further aspect of the present invention, the iron oxide film has a surface roughness not less than 25 .mu.mRz but not more than 35 .mu.mRz. In another aspect of the present invention, the iron oxide film has a thickness not less than 0.05 .mu.m but not more than 5 .mu.m. In a further aspect of the present invention, the major component of the iron oxide film is Fe.sub.3 O.sub.4.

Abstract: A sintered Fe alloy for a valve seat is made of a prepared powdery alloy which comprises C of from 0.3 wt. % to 1.6 wt. %, Cu of from 5 wt. % to 20 wt. %, hard particle of from 5 wt. % to 40 wt. % which consists of at least one species selected from ferroalloy, ceramic and intermetallic compound, and a balance which is a powdery Fe atomizing alloy containing at least one species of from 1 wt. % to 8 wt. % selected from Cr and Mo. The prepared powdery alloy containing the above-mentioned component and content is subject to a press forming process by a compression molding to form a green compact body which is then sintered. The sintered Fe alloy has a high thermal conductivity, a high strength at a high temperature and an excellent abrasion resistance, and, moreover, can be used for a valve seat provided in a high function engine.

Abstract: The invention is directed to an iron series sintered alloy superior in abrasion resistance, preferably usable for slipping parts such as valve seats used in internal combustion engines, vanes in compressors and so forth. The sintered alloy is of base matrix of a mixed structure comprising the primary phase of in area ratio 30.about.95% mainly of Fe having a hardness of 400 Hv or above with precipitated fine carbide of 10 .mu.m or smaller, and the secondary phase of in area ratio 5.about.70% softer than said primary phase, consisted of pure iron or carbon steel or low alloy steel. This base matrix will include in area ratio 1.about.20% infiltrated or previously added Cu phase or Cu alloy phase, or will include dispersed therein in area ratio 1.about.20% hard particles having average diameter of 20.about.100 .mu.m and a hardnessof 700.about.1500 Hv such as Fe--Mo paricles, Cr--Mo--Co intermetallic compound particles, C--Cr--W--Co particles, etc.

Abstract: A synchronizer ring performing synchronous sliding operation with and separating operation from a rotating object member, is composed of an Fe sintered alloy. The Fe sintered alloy comprises carbon of from 1.2 wt. % to 2.0 wt. %, copper of from over 15.0 wt. % to 25.0 wt. %, and the balance being iron and incidental impurities. A free Cu phase is precipitated in a matrix of the synchronizer ring. The synchronizer ring has a high scuffing resistance, an excellent friction characteristic, and sufficient abrasion resisting property and strength, and moreover, provides an easy manufacture thereof by means of a size working and is stable in quality.

Abstract: The invention is directed to a joined type valve seat which is joined into the cylinder head of an aluminum alloy in an internal combustion engine by resistance welding and, in particular, to an improved joined type valve seat superior in strength, rigidity, and abrasion resistance, whereby no cracks are caused when running the engine or when joining the valve seat to the engine block by resistance welding. The valve seat is made of a material having a tensile strength of 300 MPa or above, a radial crushing strength of 500 MPa or above, an elongation of 0.6% or more, a thermal conductivity of 15 W/(m.multidot.K) or above, a coefficient of thermal expansion of 10.times.10-.sup.6 (1/K) or above, and an electric resistivity of 50 .mu..OMEGA..multidot.cm or below.

Abstract: A valve seat for an internal combustion engine provided with a base member, wherein said base member comprises; a matrix of iron-based alloy comprising (a) carbon in a range of 0.5-1.5 weight % based on weight of said base member, (b) at least one element selected from a group consisting of nickel, cobalt and molybdenum in a range of 2.0-20.0 weight % in total based on weight of said base member and (c) iron as a remainder; cobalt-based hard particles dispersed in said matrix in a range of 26-50 weight % based on weight of said base member.

Abstract: A machine element has a shaft and at least a fitting member such as a cam or gear mounted on the shaft by pressure-fit. The fitting member has a bore for receiving the shaft. The shaft is formed with protrusions at least an area of the shaft on which the fitting member is fitted. The protrusions preferably extend continuously or discretely, peripherally or helically on the outer surface of the shaft and have a diameter larger than than the remaining areas of the shaft. The bore of the fitting member is formed with at least an inner chordal surface having a perpendicular from the center of the bore smaller than the radius of the protrusions. The fitting member is configured to be forced onto the protrusions of the shaft with at least one inner chordal surface forming a corresponding outer surface on the protrusions in a shaving and/or deforming operation.

Abstract: The present invention is directed to a method of applying a magnetic thin film on a substrate by alloy electroplating in which the alloy content in the deposition is defined by an electric current density in the course of the plating operation. The magnetic thin film is superior in uniformity and formability on a complicated substrate. The method comprises the step of changing the electric current density from a low value to a high value, and vice versa at predetermined intervals during plating to laminate different alloy-content plated layers into a multilayer thin film, and improving the magnetic characteristics of the film by heat treatment.

Abstract: A camshaft made of cast iron containing at least one element selected from the group consisting of Bi, Te, Se, As, Sb and Sn in a total amount of 0.0001 to 0.1 weight %, preferably, 0.001 to 0.1 weight %. The cast iron may further contain at least one element selected from the group consisting of Ni, Cu and Co, in an amount of 0.2 to 5.0 weight %. Furthermore, in the camshaft of the present invention, a carbide area ratio at the sliding surface of the cam lobe portion is not less than 40%, the chilled carbide has an average grain diameter of not more than 15 .mu.m, and the sliding surface of the cam lobe portion has a hardness of not less than HRC 53.