Abstract: When a powder material (5) is molded by introducing the material into a cavity (11) between a lower punch (2) and a die (1), compression molding the material between upper and lower punches (3 and 2) into a compact (51) of desired shape, and moving up the lower punch (2) to eject the compact (51), a lubricant is applied to the interior surface of the die (1) by fitting a pad (24) around the lower punch (2) and impregnating the pad with the lubricant. Since the lubricant is applied on every molding operation, molding operation can be continuously carried out.

Abstract: When a powder material (5) is molded by introducing the material into a cavity (11) between a lower punch (2) and a die (1), compression molding the material between upper and lower punches (3 and 2) into a compact (51) of desired shape, and moving up the lower punch (2) to eject the compact (51), a lubricant is applied to the interior surface of the die (1) by fitting a pad (24) around the lower punch (2) and impregnating the pad with the lubricant. Since the lubricant is applied on every molding operation, molding operation can be continuously carried out.

Abstract: When a powder material (5) is molded by introducing the material into a cavity (11) between a lower punch (2) and a die (1), compression molding the material between upper and lower punches (3 and 2) into a compact (51) of desired shape, and moving up the lower punch (2) to eject the compact (51), a lubricant is applied to the interior surface of the die (1) by fitting a pad (24) around the lower punch (2) and impregnating the pad with the lubricant. Since the lubricant is applied on every molding operation, molding operation can be continuously carried out.

Abstract: A rare earth sintered magnet is prepared from a corresponding alloy powder, using a mold comprising a die, an upper punch, and a lower punch which is divided into a plurality of punch segments which are independently movable within the die. The method comprises the steps of filling the mold cavity with the alloy powder when one or more selected punch segments are moved to a higher position than the remaining punch segments; moving the selected punch segments down to the position where the selected and remaining punch segments assume the normal shape of the lower punch during the compression step; compressing the alloy powder between the upper and lower punches under a magnetic field while the normal shape of the lower punch is maintained, for thereby molding a compact; and heat treating the compact.

Abstract: When a powder material (5) is molded by introducing the material into a cavity (11) between a lower punch (2) and a die (1), compression molding the material between upper and lower punches (3 and 2) into a compact (51) of desired shape, and moving up the lower punch (2) to eject the compact (51), a lubricant is applied to the interior surface of the die (1) by fitting a pad (24) around the lower punch (2) and impregnating the pad with the lubricant. Since the lubricant is applied on every molding operation, molding operation can be continuously carried out.

Abstract: A rare earth sintered magnet is prepared from a corresponding alloy powder, using a mold comprising a die, an upper punch, and a lower punch which is divided into a plurality of punch segments which are independently movable within the die. The method comprises the steps of filling the mold cavity with the alloy powder when one or more selected punch segments are moved to a higher position than the remaining punch segments; moving the selected punch segments down to the position where the selected and remaining punch segments assume the normal shape of the lower punch during the compression step; compressing the alloy powder between the upper and lower punches under a magnetic field while the normal shape of the lower punch is maintained, for thereby molding a compact; and heat treating the compact.

Abstract: A spline rolling tool including a plurality of forming teeth that are to bite into a cylindrical workpiece so as to roll splines in the workpiece. Each of the forming teeth has an incomplete toothed region in which a crest of each forming tooth is removed such that an upper end of each forming tooth in the incomplete toothed region is defined by an incomplete-toothed region surface that includes a curved surface portion, a flat surface portion and a slant surface portion. The incomplete-toothed region surface is defined at its periphery by a chamfered edge that has a surface roughness of not larger than about 3.2 ?m. Also disclosed is a process of manufacturing the spline rolling tool, which includes a chamfering step of forming the chamfered edge by using a wire brush having abrasive grains that are fixed to bristles of the wire brush.

Abstract: There is provided a rolling die and a method for forming a thread or worm and a spline having a small number of teeth whose number is thirteen or less simultaneously by rolling. By use of rolling dies, the formation of a worm by rolling by use of a thread rolling die starts, and after that, the formation of a spline having a small number of teeth by rolling starts by use of a spline rolling die while continuing the formation of the worm. Accordingly, a rolled material can be rolled forcibly by a driving source from the worm rolled using the thread rolling die. As a result, the spline having a small number of teeth whose number is thirteen or less can be formed by rolling onto the rolled material at the same time as the formation of the worm.

Abstract: A spline rolling tool including a plurality of forming teeth that are to bite into a cylindrical workpiece so as to roll splines in the workpiece. Each of the forming teeth has an incomplete toothed region in which a crest of each forming tooth is removed such that an upper end of each forming tooth in the incomplete toothed region is defined by an incomplete-toothed region surface that includes a curved surface portion, a flat surface portion and a slant surface portion. The incomplete-toothed region surface is defined at its periphery by a chamfered edge that has a surface roughness of not larger than about 3.2 ?m. Also disclosed is a process of manufacturing the spline rolling tool, which includes a chamfering step of forming the chamfered edge by using a wire brush having abrasive grains that are fixed to bristles of the wire brush.

Abstract: There is provided a rolling die and a method for forming a thread or worm and a spline having a small number of teeth whose number is thirteen or less simultaneously by rolling. By use of rolling dies, the formation of a worm by rolling by use of a thread rolling die starts, and after that, the formation of a spline having a small number of teeth by rolling starts by use of a spline rolling die while continuing the formation of the worm. Accordingly, a rolled material can be rolled forcibly by a driving source from the worm rolled using the thread rolling die. As a result, the spline having a small number of teeth whose number is thirteen or less can be formed by rolling onto the rolled material at the same time as the formation of the worm.

Abstract: In forming helical splines with stoppers on a rotary shaft, its large-diameter portion is held between a pair of rolling tools, each of which comprises: a helical teeth forming die having inclined teeth; an aligning teeth die having aligning teeth which are aligned with every other inclined tooth when combined with the helical teeth forming die; and a finishing teeth die having finishing teeth which are equal in pitch to the aligning teeth. Under this condition, the shaft is rolled under pressure by moving the rolling tools, to form helical grooves, and communication grooves communicated with every other helical grooves on the large-diameter portion, leaving stoppers between the communication grooves. Hence, the helical splines are formed by one rolling operation, with burrs formed between the spline grooves and the communication grooves being automatically removed.