Abstract: A pressed article includes a main body, a recess portion, a pin, and a groove portion. The main body has a plate shape. The recess portion is provided in a first surface of the main body facing one side in a plate thickness direction of the main body. The pin is provided at a position corresponding to the recess portion on a side of a second surface opposite to the first surface of the main body, is formed to have an outer shape smaller than that of the recess portion when viewed in the plate thickness direction of the main body, and protrudes in the plate thickness direction of the main body. The groove portion is recessed from the second surface of the main body toward the first surface and is provided to surround at least a part of the periphery of the pin.

Abstract: A preparatory molding roll 4 having a convex push surface 41 is pushed to an outer peripheral surface of a work 1A while the work 1A is chucked by a pair of molds 2 and 3 and is rotated by applying axial propelling force, to bend inward the outer peripheral surface of the work in a radial direction. The work is then chucked by the preparatory molding roll and the upper and lower molds. Next, the preparatory molding roll is moved back and the work is crushed in the axial direction to form a bent portion 1a. A molding roll 5 is pushed to mold the outer shape of the work. A grooved roll 6 is next pushed to the outer peripheral surface of the work and a groove 1b is formed on the outer peripheral surface.

Abstract: A preparatory molding roll 4 having a convex push surface 41 is pushed to an outer peripheral surface of a work 1A while the work 1A is chucked by a pair of molds 2 and 3 and is rotated by applying axial propelling force, to bend inward the outer peripheral surface of the work in a radial direction. The work is then chucked by the preparatory molding roll and the upper and lower molds. Next, the preparatory molding roll is moved back and the work is crushed in the axial direction to form a bent portion 1a. A molding roll 5 is pushed to mold the outer shape of the work. A grooved roll 6 is next pushed to the outer peripheral surface of the work and a groove 1b is formed on the outer peripheral surface.

Abstract: An annular groove portion is formed between portions corresponding to groove portions and thereafter the groove portions are formed while the annular groove is pressed. Consequently, since the stress produced due to a plastic deformation in forming the groove portions can be absorbed by the annular groove having a smaller rigidity than the groove portions, no undesirable plastic deformation of the groove portions occurs and hence the accuracy of the finished size of the multi-stage pulley can be improved. Furthermore, the capital investment in groove forming rollers can be reduced and the manufacturing cost of the multi-stage pulley can be reduced.

Abstract: The manufacturing cost of a multi-stage pulley is reduced without coaxially arranging a plurality of groove forming sections. While a portion between groove sections 103 is being pushed by a pushing roller 204, the groove sections 103 are successively formed. While a portion of workpiece W2 pushed by a groove forming roller 206 to form one groove section 103a and a portion of workpiece W2 pushed by a groove forming roller 207 to form the other groove section 103b are being shifted from each other in the circumferential direction, one groove section (103a) and the other groove section (103b) are simultaneously formed. Due to the foregoing, when the groove sections 103 are formed, it is possible to prevent the deformation of the groove section 103 and the groove section 103 which is adjacent to it. Accordingly, it is possible to enhance the yield of the multi-stage pulley 100 without coaxially arranging a plurality of groove forming sections.

Abstract: An annular groove portion is formed between portions corresponding to groove portions and thereafter the groove portions are formed while the annular groove is pressed. Consequently, since the stress produced due to a plastic deformation in forming the groove portions can be absorbed by the annular groove having a smaller rigidity than the groove portions, no undesirable plastic deformation of the groove portions occurs and hence the accuracy of the finished size of the multi-stage pulley can be improved. Furthermore, the capital investment in groove forming rollers can be reduced and the manufacturing cost of the multi-stage pulley can be reduced.

Abstract: A disk material is plastic-formed to form an inner cylindrical portion of a rotor and a cover member which covers an end side of the rotor. After that, the disk material is slit inwardly from an outside thereof in a radial direction of the disk material to form an outer cylindrical portion of the rotor and a pulley corresponding portion which will be the pulley. Finally, the pulley corresponding portion is plastic-formed to form a pulley groove. Thereby, even when the location of the pulley relative to the outer cylindrical portion are different, same processes can be applied to these different type pulley integrated rotors until the disk material is slit. That is, many different type pulley integrated type rotors can be manufactured with low cost while maintaining high concentric accuracy between the pulley and the rotor.

Abstract: In forming a multi-grooved V pulley by roll forming, a preliminary forming method is disclosed for preventing the occurrence of a top roll accompanied by a crack along each annular ridge of the pulley. A preliminary form roller is pressed against an annular material to fabricate a preliminary form having, in a sectional view, a corrugation including linear flat root portions and ridges alternating with them on the bottom surface of a wide annular groove. Next, a finish form roller having a plurality of annular V-shaped protrusions is pressed against the linear flat root portions of the preliminary form to thereby finish roll the preliminary form. The forward end of each V-shaped protrusion is kept off from the slopes of the corrugation ridges, and therefore is not broken under a bending moment.

Abstract: A multi-stepped pulley, and a method and apparatus for manufacturing the same, wherein the mechanical strength is increased while keeping down an increase of mass and a rise of manufacturing costs by pressing against portions of a surface of a hollow metal material having a circular cross-section corresponding to a connection portion of a plurality of pulleys by pressing rollers and simultaneously crushing the material in an axial direction so as to integrally form first and second rims, first and second webs, and a connection portion thereof.

Abstract: A workpiece W2 is grasped by inserting a first jig into a concave portion which is formed in a rotor forming process, and by interfitting a second jig to a convex portion which is also formed in the rotor forming process. Thereby, the workpiece W2 is firmly grasped, and a groove-forming roller can be strongly pressed into the workpiece W2. A time for forming a pulley groove is shortened, and a manufacturing cost thereof is reduced.

Abstract: A ring-shaped flange is molded at one end of a cylindrically-shaped body in a flange molding process. In an edge surface molding process performed after the flange molding process, a cylindrically-shaped body thinner than a hot rolled steel plate, a truncated cone-shaped connecting portion extending in an axial direction from the body, and a smallest diameter portion thinner than the body at the other end of the body are molded. Next, in a slotting process, a slotting punch is driven in from the slanting surface of the connected portion to form the other guide-molded portion, and in a trimming process, the flange is trimmed off in order to remove the unnecessary volume to form a poly V-pulley from the work.

Abstract: A shield member is placed in a case, and connector pins extend through respective through capacitors and are soldered to the shield member. A core is inserted in the case, and has an engaging member engaging an upstanding portion of the case, the core having a gap fitted over a ridge on the case. A printed-circuit board has positioning holes fitted over pins on the core. The connector pins have respective upper ends inserted through and soldered to through holes defined in the printed-circuit board. Attachment holes defined in the printed-circuit board are held in registry with threaded holes defined in an upper end of the upstanding portion of the case, and the printed-circuit board is fastened to the upstanding portion by screws threaded through the attachment holes into the threaded holes. A shield cover is bent over into alignment with an upper edge of the shield member, and teeth on the shield member are bent inwardly onto and soldered or spot-welded to the shield cover.