Abstract: Provided is a method for manufacturing a sintered component having a hole formed therein, in which a sintered component having no defect, such as cracks, can be manufactured with good productivity and also a reduction in tool life accompanied by forming the hole can be suppressed. The method for manufacturing a sintered component includes a molding step of press-molding a raw material powder containing a metal powder and thus fabricating a green body; a drilling step of forming a hole in the green body using a candle-type drill and thus forming a thin-walled portion, of which a thickness Gt as measured between an inner circumferential surface of the hole and an outer surface of the green body is smaller than a diameter Gd of the hole; and a sintering step of sintering the green body after the drilling step.

Abstract: The invention is directed to a method of manufacturing a green compact. The method includes a filling step of filling a compacting space with an insulated coated soft magnetic powder. The compacting space is defined by a die. The die has a through hole with which a part of the outer circumferential surface of the green compact is molded. The die also has a core rod with which another part of the outer circumferential surface of the green compact is molded, and a first punch disposed so as to cover one of opening portions of the through hole, the core rod being inserted and disposed in a space of the through hole. The method also includes a pressurizing step using the first punch and a second punch disposed so as to face the first punch. The method also includes a removing step.

Abstract: An iron-based powder for powder metallurgy includes an iron-based powder and a composite oxide powder, and the composite oxide contains, by mass, from 15% to 30% Si, from 9% to 18% Al, from 3% to 6% B, from 0.5% to 3% Mg, from 2% to 6% Ca, from 0.01% to 1% Sr, and from 45% to 55% O.

Abstract: Provided is a jointed component (A) in which a first member (10) and a second member (20) in which a pillar (22) stands erect on a surface of a base (21) are fixed to each other, the second member. The jointed component includes the first member and the second member including the base and the pillar disposed on the first surface of the base. The pillar is brought into contact with the first member in an axial direction. The second member includes a positioning surface (23) that has a height difference from an end surface of the second member in the axial direction and the second member includes a curved surface at a ridge between the positioning surface and a side surface of the pillar.

Abstract: An iron-based powder for powder metallurgy includes an iron-based powder and a composite oxide powder, and the composite oxide contains, by mass, from 15% to 30% Si, from 9% to 18% Al, from 3% to 6% B, from 0.5% to 3% Mg, from 2% to 6% Ca, from 0.01% to 1% Sr, and from 45% to 55% O.

Abstract: Provided is a stepped die which includes: an inner ring having a cylindrical shape, and an outer ring having a cylindrical shape which is fitted on an outer periphery of the inner ring by shrinkage fitting, in which a recessed portion for molding which has a stepped portion is formed on an inner side of the inner ring. A shrinkage fitting ratio of the outer ring to the inner ring is set to a value which falls within a range of from 0.12% to 0.25%.

Abstract: A low-loss compact and a method for producing the compact are provided. A method for producing a compact by using coated soft magnetic powder that includes coated soft magnetic particles constituted by soft magnetic particles and insulating coatings coating outer peripheries of the soft magnetic particles includes a raw material preparation step and an irradiation step. In the raw material preparation step, a raw compact is prepared by press-forming coated soft magnetic powder. In the irradiation step, part of a surface of the raw compact is irradiated with a laser. Irradiating a part of a surface of a raw compact with laser increases the number of disrupted portions of conductive portions where constituent materials of the soft magnetic particles at the surface of the raw compact have become conductive to each other, and the loss of the compact can be decreased.

Abstract: Provided is a jointed component (A) in which a first member (10) and a second member (20) in which a pillar (22) stands erect on a surface of a base (21) are fixed to each other, the second member. The jointed component includes the first member and the second member including the base and the pillar disposed on the first surface of the base. The pillar is brought into contact with the first member in an axial direction. The second member includes a positioning surface (23) that has a height difference from an end surface of the second member in the axial direction and the second member includes a curved surface at a ridge between the positioning surface and a side surface of the pillar.

Abstract: An internal gear pump includes a pump rotor (4) in which a meshing point between an inner rotor (2) having n teeth and an outer rotor (3) having (n+1) teeth is located rearward, in a rotational direction of the rotor, relative to an eccentric axis (CL) along which a center (OI) of the inner rotor and a center (OO) of the outer rotor are disposed. A tooth-surface curve of the outer rotor (3) near a meshing section thereof is formed by duplicating thereto a tooth-surface shape of the inner rotor (2) near a meshing section thereof.

Abstract: The present invention relates to a method for molding a powder mold product according to which a powder mold product of uniform quality can be molded with excellent productivity. The present invention includes the steps of: preparing raw material powder 3 (a preparing step); interposing a mold assembly-use lubricant between an outer circumferential face 12s of a first punch (a lower punch 12) and an inner circumferential face 10s of a die 10, the lower punch 12 and the die 10 in this state being relatively shifted to apply the mold assembly-use lubricant to the inner circumferential face 10s of the die 10 (an applying step); and packing the raw material powder 3 into a cavity, a powder mold product 100 being molded by the raw material powder 3 being pressed (a molding step).

Abstract: A tooth profile of an inner rotor 2 is formed by an envelope of a group of circular arcs of a locus circle C having a center on a trochoidal curve TC. The envelope of the group of circular arcs is formed by rolling a rolling circle having a predetermined diameter along a base circle without slipping and drawing the trochoidal curve TC based on a point distant from the center of the rolling circle by a distance equivalent to an amount of eccentricity between the two rotors. A diameter d2 of the locus circle C is constant until one point between an addendum point and a dedendum point of the inner rotor and changes from the one point such that a diameter d2B at the dedendum point becomes larger than a diameter d2T at the addendum point of the inner rotor.

Abstract: A compact 10 is obtained by compression-molding coated soft magnetic particles covered with insulating coatings, and is a modified frustum body having, as a main body, a frustum portion 113 sandwiched between plate-shaped portions 111 and 112 arranged in opposing relation. A vertical cross-section of the compact 10 is made up of a trapezoidal surface 113s, a long-side rectangular surface 111s joining to a long side of the trapezoidal surface 113s, and a short-side rectangular surface 112s joining to a short side of the trapezoidal surface 113s.

Abstract: There is provided a sliding member that has sufficient wear resistance and good adhesion to a base formed of a sintered body. The sliding member includes a surface layer formed of a crosslinked fluoropolymer and a base that adheres closely to the surface layer. The base is a sintered body having a full density ratio in the range of 0.75 to 0.96 and is formed of a material having higher thermal conductivity than a fluoropolymer. The surface layer has a thickness in the range of 1 to 300 ?m.

Abstract: In an internal gear pump 9, a diameter of a base circle is set to A mm, a radius of a rolling circle is set to b mm, a diameter of a locus circle is set to C mm, and an amount of eccentricity is set to e mm. A trochoidal curve T is drawn by rolling the rolling circle along the base circle without slipping and by using a locus of a fixed point distant from a center of the rolling circle by e. A tooth profile of an inner rotor 2 having n teeth is formed based on an envelope of a group of the locus circles each having a center on the trochoidal curve T. A pump rotor 1 is formed by combining the inner rotor with an outer rotor having (n+1) teeth. A tooth-profile curve of the inner rotor satisfies the following expression (1). Because K<1 is satisfied, cusps s are not formed at opposite edges of each addendum of the inner rotor 2.

Abstract: An internal gear pump includes an inner rotor having n teeth and an outer rotor having (n+1) teeth. A tooth profile of the inner rotor is an envelope of a group of locus circles (13) each having a diameter C and having a center on a trochoidal curve (T), the trochoidal curve being drawn along a locus of a fixation point, which is located distant from a center of a rolling circle (12) by e, when the rolling circle (12) rolls along a base circle (11) without sliding. A tooth profile of the outer rotor is an envelope of a group of tooth-profile curves of a formation inner rotor, the envelope being obtained by first drawing the formation inner rotor in which a diameter of the locus circle (13) is equal to C? determined from expression (C?t), revolving a center (OI) of the formation inner rotor by one lap along a circle (S) having a diameter (2e) and centered on a center (OO) of the outer rotor, and rotating the formation inner rotor 1/n times during the revolution.

Abstract: When an outer core that is to be mounted on a reactor is seen in plan, the outer core is a compact that has a plan-view shape in which a side of the outer core that is opposite to a facing side of the outer core, which faces the inner cores, has a smaller dimension in a width direction, which is parallel to a facing surface, than the facing side of the outer core. A method of manufacturing such an outer core includes a preparing step and a compacting step. In the preparing step, coated soft magnetic powder including multiple coated soft magnetic particles formed by coating soft magnetic particles with insulating coated films is prepared as raw-material powder of the outer core.

Abstract: An object is to meet the demands for increasing the number of teeth of a rotor in an internal gear pump while maintaining a theoretical discharge amount by using an equivalent body configuration so as to enhance the pump performance relating to discharge pulsation due to the increased number of teeth. In a pump rotor 1 formed by combining of an inner rotor (2) having N teeth and an outer rotor (3) having (N+1) teeth and disposing the rotors eccentrically relative to each other, the relational expression ?Dmax<1.7e·sin(?/180)/sin {?/(180·N)} is satisfied, ?Dmax being a maximum value of a working pitch diameter of the inner rotor (2) and the outer rotor (3), and a working position (G) of the inner rotor (2) and the outer rotor (3) is always located rearward of an eccentric axis (CL) in a rotating direction of the rotor.