Abstract: The present invention relates to a method of forming a key portion on a sheet metal member, the key portion being useful in coupling of a shaft to a member such as a pulley used in an automobile. According to the method of the invention, an inner metal part of a cylindrical portion of the sheet metal member is pressed in the axial direction so that the inner metal part is removed away and a predetermined place of the inner metal part remains, the remaining metal part being used as the key portion. Pressing the inner metal part in the axial direction of the cylindrical portion can be conducted by a pressing process in which a pressing die is moved in the axial direction of the cylindrical portion. A key portion can be easily formed on the cylindrical portion, and an inner flange can be formed together with the key portion.

Abstract: A sheet metal member thickening method according to the present invention comprises the steps of rotating a disc-shaped sheet metal member held between rotating dies, and pressing a first forming roller and a second forming roller subsequently against a periphery thereof while rotating it, thereby forming a base plate and a thickened peripheral wall thereof. A first forming step comprises plural small steps, including a previous small step in the first forming step and a post small step following the previous one.

Abstract: The present invention relates a method of producing a sheet metal poly-V groove pulley in which a thickened annular peripheral wall of an outer peripheral side of a base plate is holding held and pressed so as to increase the axial length of the annular peripheral wall, thereby forming a drum wall and preliminary ears projected from the root portion of the drum wall, and thereafter a step of forming poly-V grooves and ears is performed so that poly-V grooves and ears which are obtained by further projecting the preliminary ears and have a single layer structure are formed on the drum wall. According to this method, the preliminary ears are previously formed and then further projected so as to form the ears. Even when a sheet metal member is thin, therefore, ears of a single-layer structure which has a sufficient projection degree can be obtained.

Abstract: The present invention is adapted to form, at the center of a plate-like metallic blank, a case-like boss projecting from one lateral side of the blank, by: curving the plate-like metallic blank such that the blank is convex punching a hole in the top of the curved blank: and bending an arcuate portion of the blank between an outer peripheral edge portion and a hole peripheral portion of the blank in the direction opposite to the convex direction thereof with the outer peripheral edge portion of the blank restrained from extending radially outwardly. Thus, the method of the present invention is adapted to form, with the use of a small press machine, a boss having a sufficient thickness and a sufficient projecting height even though the boss has a small inner diameter, without the thickness of the initial material reduced so much in the course of the production steps.

Abstract: To form a seal ring groove in the outer peripheral surface of a steel plate having a circular contour, the present invention provides a method of producing fluid-chamber component elements by which the peripheral portion of the steel plate held by and between a pair of rotary molds is thickened with the use of a roller before the seal ring groove is formed. According to the method of the present invention, a preliminary thickened portion is first formed at the peripheral portion of the steel plate. Then, there is formed, at the outer peripheral surface of the steel plate, a final thickened portion having such a thickness that the seal ring groove can be formed therein. This prevents the steel plate from being buckling by a pushing force applied by a roller at the time when forming the final thickened portion.

Abstract: A lightweight V-grooved pulley obtained from a metal plate and having a cylindrical member with one open end, the cylindrical member having a circumferential surface formed with at least one groove having a substantially V-shaped section is provided in which the material of the metal plate consists of an aluminum alloy containing 2 to 6 wt% of Mg, at least one of 0.005 to 0.2 wt % of Ti, and 0.0005 to 0.02 wt % of B, impurities containing not more than 0.2 wt % of Si, not more than 0.2 wt % of Fe, and not more than 0.5 wt % of Zn, and a balance consisting of Al and an inevitable impurity, and an anodized film is formed on a region including the groove. The material of the metal plate may additionally contain at least one element selected from the group consisting of 0.01 to 2.0 wt % of Cu, 0.02 to 1.0 wt % of Cr, and 0.01 to 0.3 wt % of Zr.

Abstract: The invention presents a manufacturing method of making poly-V pulleys for bending the peripheral end part of the disc-shaped sheet metal blank in concave or convex form, flattening the bent portion so as not to elongate it in the radial direction, increasing the thickness of the peripheral end part of the disc-shaped sheet metal blank, forming the thickened sheet metal blank into a cup form, and forming poly-V grooves at the outer side of the peripheral wall of the cup-shaped blank, and the products thereof. By increasing the thickness of the part corresponding to the peripheral wall of the cup-shaped blank in the stage of the disc-shaped sheet metal blank, the peripheral wall of the cup-shaped blank may be increased in thickness by a simple press machine and at high efficiency.

Abstract: The invention relates to a sheet metal made poly-V pulley in which poly-V grooves (10) to be engaged with poly-V belt are formed in the outer circumference of peripheral wall (5) of a cup-shaped blank (3) integrally forming the peripheral wall (5) extending in the direction orthogonal to the bottom wall (6) at the end part of the bottom wall (6), and annular ears (7, 9) of single layer projecting outward in the radial direction for preventing dislocation of the poly-V belt are formed at both ends of the peripheral wall (5), wherein the end part inner surface side of the bottom wall (6) side of the peripheral wall (5) is bulged inward in the radial direction when forming the ears (7) or before forming the ears (7) to thicken the bottom wall side end part of the peripheral wall, and hence the wall thickness of the bottom wall (6) side end part of the peripheral wall (6) is maintained even when a thin cup-shaped blank (3) is used, so that the problems of the strength, material cost and weight increase may be sol