Abstract: A soft magnetic material has an iron based powder that has an insulating coating on the surface and an ester wax. The ester wax is added in an amount not less than 0.02% by weight and not more than 0.6% by weight in relation to the soft magnetic material. Consequently, seizure between a metal mold and a material to be molded at the time of molding can be suppressed and the arising of a black residue can be prevented.

Abstract: A mixed powder is obtained by adding at least one kind of solid ester wax to an iron-based powder for powder metallurgy use. The mixed powder is molded. The melting point of the ester wax is 100° C. or lower, the quantity of the ester wax added is in the range of 0.02 wt % or more to 0.6 wt % or less, and the temperature of the mold when the molding is performed is set in a range of (the melting point of the ester wax+10° C.) or more to 200° C. or less. The ester wax thereby liquefies on the surface of the mold and bleeds out when the molding is performed. As a result, molded sintered parts with complex shapes, good surface characteristics, and high densities can be easily obtained.

Abstract: A soft magnetic material includes: a plurality of composite magnetic particles formed from a metal magnetic particle and an insulative coating surrounding a surface of the metal magnetic particle and containing metallic salt phosphate and/or oxide; and a lubricant formed as fine particles added at a proportion of at least 0.001 percent by mass and no more than 0.1 percent by mass relative to the plurality of composite magnetic particles. With this structure, superior lubrication is provided during compacting and desired magnetic characteristics can be obtained after compacting.

Abstract: A compound magnetic material having high heat resistance is provided. A fabrication method of a compound magnetic material includes the step of preparing mixed powder including an organic resin and compound magnetic particles. The long-period heat resistance temperature of the organic resin is at least 200° C. The containing ratio of the organic resin to the compound magnetic particles exceeds 0 mass % and not more than 0.2 mass %. The compound magnetic particle includes a metal magnetic particles, and a coat layer containing metal oxide, directly bound to the surface of the metal magnetic particle. The fabrication method of a compound magnetic material includes the steps of forming a compact by introducing mixed powder into a die having a lubricant applied to its surface and conducting warm-compacting, and applying heat treatment to the compact.

Abstract: An object of the present invention is to provide a soft magnetic material exhibiting excellent magnetic characteristics regardless of the frequency to be applied and a dust core produced from the soft magnetic material. The means for solving the invention is a soft magnetic material that comprises metal magnetic particles 10 containing iron and oxygen. The ratio of oxygen contained in metal magnetic particles 10 is more than 0 and less than 0.05% by mass. A dust core produced using such a soft magnetic material has a coercive force of 2.0×102 A/m or less.

Abstract: A method for making soft magnetic material includes: a first heat treatment step applying a temperature of at least 400 deg C. and less than 900 deg C. to metal magnetic particles (10); a step for forming a plurality of compound magnetic particles (30) in which said metal magnetic particles (10) are surrounded by insulation film (20); and a step for forming a shaped body by compacting a plurality of compound magnetic particles (30). This provides a method for making soft magnetic material that provides desired magnetic properties.

Abstract: The present invention provides a soft magnetic material and a powder magnetic core having desired magnetic characteristics. A soft magnetic material contains a metal magnetic powder 10. The metal magnetic powder 10 is formed from crystals 1 with an average size, as determined from X-ray diffraction, of at least 30 nm. It would be preferable, in the metal magnetic particles 10, for crystal grains 2 to have an average size of at least 10 microns.

Abstract: The method of manufacturing soft magnetic articles comprises a step of preparing a melt solution containing soft magnetic materials and a step of forming soft magnetic particles from the melt solution in a magnetic field by an atomization rapid solidification method.

Abstract: A compound magnetic material having high heat resistance is provided. A fabrication method of a compound magnetic material includes the step of preparing mixed powder including an organic resin and compound magnetic particles. The long-period heat resistance temperature of the organic resin is at least 200° C. The containing ratio of the organic resin to the compound magnetic particles exceeds 0 mass % and not more than 0.2 mass %. The compound magnetic particle includes a metal magnetic particles, and a coat layer containing metal oxide, directly bound to the surface of the metal magnetic particle. The fabrication method of a compound magnetic material includes the steps of forming a compact by introducing mixed powder into a die having a lubricant applied to its surface and conducting warm-compacting, and applying heat treatment to the compact.

Abstract: To lighten the weight of an electromagnetic actuator and a valve-open-close mechanism by forming the stems from a lighter material than conventional. A pair of electromagnets formed of stators and coils are opposed to each other with a gap therebetween. An armature is disposed in the gap so as to be reciprocable between one electromagnet and the other electromagnet by the electromagnets. A first stem for transmitting the movement of the armature from one electromagnet toward the other electromagnet to a valve of the internal combustion engine is inserted in a guide hole formed in the stator of one electromagnet. The first stem is formed of a lighter material than the armature to lighten the weight of the electromagnetic actuator and a valve-open-close mechanism of an internal combustion engine.

Abstract: Provided is a diamond-coated sliding part that is light, has excellent abrasion resistance, that prevents abrasion of the material of an opposite member, and that is effective in reducing power loss. This sliding part is especially useful as an adjusting shim for the valve train mechanism of an internal combustion engine such as an automobile engine in which the base material is silicon nitride or sialon and this base material surface is coated with a diamond coating layer. By performing finish processing on only a small part of peaks of diamond particles protruding from the surface of the diamond coating layer to reduce the height of the protrusions, or by controlling film forming conditions, etc., the profile bearing length ratio (tp) at a cutting level of 0.1 &mgr;m for the sliding surface of the diamond coating layer is made 60% or greater.

Abstract: To lighten the weight of an electromagnetic actuator and a valve-open-close mechanism by forming the stems from a lighter material than conventional. A pair of electromagnets formed of stators and coils are opposed to each other with a gap therebetween. An armature is disposed in the gap so as to be reciprocable between one electromagnet and the other electromagnet by the electromagnets. A first stem for transmitting the movement of the armature from one electromagnet toward the other electromagnet to a valve of the internal combustion engine is inserted in a guide hole formed in the stator of one electromagnet. The first stem is formed of a lighter material than the armature to lighten the weight of the electromagnetic actuator and a valve-open-close mechanism of an internal combustion engine.

Abstract: An electromagnetic actuator for an automotive internal combustion engine is provided which has a stator, the weight of which is reduced. The electromagnetic actuator has a pair of electromagnets each made up of a stator and a coil, an armature disposed between the pair of electromagnets so as to be reciprocable therebetween, and a first stem provided on one side of the armature for transmitting the movement of the armature to external. The stator is formed by powder molding.

Abstract: It is proposed to lessen the weight and improve the mechanical strength of a retainer of a valve open-close mechanism driven by an electromagnetic actuator used in an automotive internal combustion engine. The electromagnetic actuator is mounted in a housing mounted on an internal combustion engine body. A first stem has its tip abutting the valve, which is provided with a retainer and carries a first coil spring. A second stem is provided on the other side of an armature. The second stem has a retainer. Between this retainer and the housing, a second coil spring is mounted. At least one of these parts is made of a metal smaller in specific weight than iron or its alloy. Each retainer has a boss and an arcuate corner portion having a radius of curvature R of 1.0 mm or over between a spring abutting surface and the boss to relieve stress concentration.

Abstract: In a combination of the shim 5 and cam 1 for use in a reciprocating mechanism portion, the shim 5 is made of a material having a hardness higher than that of the sliding surface of the cam 1 and the sliding surface of the shim 5 is finished to within a range of the surface roughness of Rz0.07-0.2 &mgr;m in 10-point mean surface roughness and further the sliding surface of the cam 1 is provided with open pores 1b. In the above combination, the generated torque and the wear of sliding portion are minimized by selecting a shim member whose surface roughness is difficult to deteriorate due to plastic deformation by a injection pump contact with a mating member and corrosion by various impurities mixed in lubricant and the like, and providing the surface of a cam member with an oil film holding function so as to maintain fluid lubrication of the sliding surface.

Abstract: A valve-open-close mechanism is proposed which has parts designed to reduce friction during sliding. The electromagnetic actuator comprises a pair of electromagnets each having a stator and a coil opposed to each other with a gap therebetween, an armature disposed in the gap, and a first stem for transmitting to external the movement of said armature. A retainer and a first return spring are provided on the valve. A second stem is provided at other side of the armature and another retainer and a second return spring are provided for the second stem. A coating film is formed on at least one of the surface or end face of the stem portion of the valve, end faces of the first return spring or second return spring, spring bearing end faces of the retainers, surface or end face of the second stem, and the surface of the armature.

Abstract: A fuel injection pump for high pressure injecting gasoline, fuel whose main component is gasoline or light oil having a sulfur content of 0.05% by weight or less by a reciprocation of a piston sliding relative to a cylinder, wherein at least a sliding surface of the piston to slide on the cylinder is made of ceramic and the surface roughness thereof, expressed in ten-point mean surface roughness Rz, is 0.05-0.4 &mgr;m in a direction perpendicular to the sliding direction and 0.2-0.6 &mgr;m in a direction parallel to the sliding direction while the surface roughness expressed in the ten-point mean surface roughness Rz of a cylinder sliding surface corresponding thereto is 0.2-0.8 &mgr;m in a direction parallel to the sliding direction. By using the above combination of piston and cylinder, the wear resistance of the piston and cylinder is improved, the durability thereof is improved and the production cost can be largely reduced.

Abstract: An electromagnetic actuator for an automotive internal combustion engine is provided which has a stator, the weight of which is reduced. The electromagnetic actuator has a pair of electromagnets each made up of a stator and a coil, an armature disposed between the pair of electromagnets so as to be reciprocable therebetween, and a first stem provided on one side of the armature for transmitting the movement of the armature to external. The stator is formed by powder molding.

Abstract: It is proposed to lessen the weight and improve the mechanical strength of a retainer of a valve open-close mechanism driven by an electromagnetic actuator used in an automotive internal combustion engine. The electromagnetic actuator is mounted in a housing mounted on an internal combustion engine body. A first stem has its tip abutting the valve, which is provided with a retainer and carries a first coil spring. A second stem is provided on the other side of an armature. The second stem has a retainer. Between this retainer and the housing, a second coil spring is mounted. At least one of these parts is made of a metal smaller in specific weight than iron or its alloy. Each retainer has a boss and an arcuate corner portion having a radius of curvature R of 1.0 mm or over between a spring abutting surface and the boss to relieve stress concentration.

Abstract: Provided is a diamond-coated sliding part that is light, has excellent abrasion resistance, that prevents abrasion of the material of an opposite member, and that is effective in reducing power loss. This sliding part is especially useful as an adjusting shim for the valve train mechanism of an internal combustion engine such as an automobile engine in which the base material is silicon nitride or sialon and this base material surface is coated with a diamond coating layer. By performing finish processing on only a small part of peaks of diamond particles protruding from the surface of the diamond coating layer to reduce the height of the protrusions, or by controlling film forming conditions, etc., the profile bearing length ratio (tp) at a cutting level of 0.1 &mgr;m for the sliding surface of the diamond coating layer is made 60% or greater.