Metal deforming – By use of tool acting during relative rotation between tool... – During rotation of work
Patent
1998-03-17
1999-08-24
Larson, Lowell A.
Metal deforming
By use of tool acting during relative rotation between tool...
During rotation of work
72110, B21H 118
Patent
active
059411139
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to a method of forming a cylindrical portion of a cylindrical member made of a sheet metal, the cylindrical portion being connectedly disposed on an outer periphery of a base plate of the cylindrical member. Specifically, the present invention relates to a method of forming the cylindrical portion of the cylindrical member made of the sheet metal, so that it has sufficient thickness and a length suitable for providing a belt winding portion around which a flat belt, a V-shaped belt, a poly-V-belt or the like are to be wound, and teeth on an inner surface or an outer surface of the cylindrical portion.
BACKGROUND OF THE INVENTION
A method of forming a cylindrical member connectedly provided with a cylindrical portion arranged at an outer periphery of a circular base plate, and projecting to one side, by means of employing a sheet metal as a base material, is known wherein pressing dies are employed to draw an outer periphery of the sheet metal, and shape it in a cylindrical state, thereby forming the base plate and the cylindrical portion.
The cylindrical portion of the cylindrical member formed by the present method has substantially the same thickness as that of the base material or the sheet metal. In forming a pulley, a gear or the like by use of such a cylindrical member, it is often required to decrease the thickness of the cylindrical portion and increase the length thereof.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a method of forming a cylindrical portion of a cylindrical member made of a sheet metal, so that the thickness of the cylindrical portion arranged on the cylindrical member and the length thereof can be respectively decreased or increased.
In order to achieve the above object, a method of forming a cylindrical portion of a cylindrical member made of a sheet metal according to the present invention, comprises the steps: whose outer periphery is connectedly provided with the cylindrical portion projecting to one side of the base plate, into rotating dies, dies, so as to thin the cylindrical portion, and extend it axially, roller is moved according to phases, from an opening end side of the cylindrical portion to a root portion side thereof.
By performing the method, the cylindrical portion is not widened toward the end (in a wide-based state like a trumpet-shape), and it is subjected to thinning and extending. The reasons why thinning and extending is performed are described below.
As shown in FIG. 8, a cylindrical portion 2 of the cylindrical member 1 is fitted into a rotating die R1, the cylindrical member 1 is rotated with the rotating die R1 while pressing a full length of the cylindrical portion 2 against the rotating die RI by means of a forming roller R2, so that the cylindrical portion 2 is thinned and axially extended. However, in this case, the cylindrical portion 2 extended by shaping is widened toward the end. The reasons will be presumed as follows. A thickness of the cylindrical portion 2 subjected to pressure by the forming roller R2 plastically flows to the opening end side of the cylindrical portion 2 in a lower direction, as indicated by arrows in the figure, with the result that the cylindrical portion 2 is thinned while it is axially extended. On the other hand, when the pressure exerted by the forming roller R2 is released, a phenomenon of restoring the thickness occurs, wherein the thickness of the cylindrical portion 2 plastically flows in a reverse direction, to a certain degree. Consequently, the extended cylindrical portion 2 is shrunken at an outer periphery thereof so that the cylindrical portion 2 is widened toward the end. An arrow P indicates a pressing direction by the forming roller R2.
On the other hand, according to the present invention, in case of employing the method wherein the cylindrical portion of the cylindrical member fitted into the rotating dies is pressed against the rotating dies by the forming roller to be thinned and extended axially, the pressed portion
Fujii Naoki
Harada Kunihiro
Kanemitsu Toshiaki
Kabushiki Kaisha Kanemitsu
Larson Lowell A.
LandOfFree
Method of forming a cylindrical portion of a cylindrical member does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of forming a cylindrical portion of a cylindrical member , we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of forming a cylindrical portion of a cylindrical member will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-456903