Metal deforming – By use of roller or roller-like tool-element – With non-roller metal deforming station
Reexamination Certificate
1999-10-04
2001-07-10
Larson, Lowell A. (Department: 3725)
Metal deforming
By use of roller or roller-like tool-element
With non-roller metal deforming station
C072S274000
Reexamination Certificate
active
06257038
ABSTRACT:
TECHNICAL FIELD
The invention relates to a method of manufacturing a columnar material of metal having a precise outside dimension.
BACKGROUND ART
Conventionally, substantially column-shaped parts, for example, a columnar material of metal having a precise outside dimension and used for shaft parts are manufactured by machining an outer periphery of a material by means of a lathe and abrasive finishing the same. With such method, it is possible to obtain a high dimensional accuracy on the order of about 0.01 mm. However, this method offers a problem of the need of much work time and cost in the grinding process, and furthermore a problem in that chip is generated from machining of the material to be prone to produce waste of the material.
A drawing working method with a die has been conventionally known as a method of manufacturing a columnar material of metal. With this method, it is possible to reduce work time and cost as compared with the method by means of machining and grinding. With the drawing working, however, it is difficult to obtain an accuracy on the order of 0.05 mm or less because an excess thickness portion runs off in a longitudinal direction of a material to change a length of a column-shaped body and a spring back phenomenon is caused due to elasticity of a metallic material to generate changes in diameter and length of the material when the metallic material leaves a die as shown in FIG.
2
.
DISCLOSURE OF INVENTION
The invention has been accomplished in order to solve the above described problems of the prior art and to provide a method of manufacturing a columnar material of metal, which has a dimensional accuracy on the order of about 0.01 mm, without the need of much work time and cost.
To solve the above described problems, the method of manufacturing a columnar material, according to the invention, comprises equally forming a multiplicity of longitudinal grooves on an outer periphery of a column-shaped raw material of metal, and then uniformly squeezing tip ends of portions between the respective longitudinal grooves to make the same flat to obtain a target outside dimension.
Preferably, the longitudinal grooves are formed by rolling, and squeezing of the tip ends is performed by means of drawing working. This is because such procedure is superior in terms of cost.
It is preferable in terms of work that the longitudinal grooves have a pitch amounting to 9 to 13% of a diameter of the column-shaped raw material, and squeezing be applied to 50% or less of a height of the tip ends. Here, the height of the tip ends corresponds to a height extending from the bottom of the longitudinal grooves to tips of the tip ends.
According to the present method, a spring back phenomenon is avoided by permitting excess thickness portions, which are generated upon application of drawing working, to run off into the longitudinal grooves, whereby tip end portions between the respective longitudinal grooves can be precisely and easily worked to provide a target outside dimension. Therefore, it is possible to obtain a columnar material of metal having a dimensional accuracy on the order of about 0.01 mm without performing machining and grinding as in the prior art.
REFERENCES:
patent: 2110275 (1938-03-01), Rabe
patent: 2586011 (1952-02-01), Doelter
patent: 3-272805 (1991-04-01), None
patent: 5-305383 (1993-11-01), None
Asakura Takashi
Ozawa Junzo
Takahashi Masafumi
Aoyama Seisakusho Company, Ltd.
Conlin David G.
Daley, Jr. William J.
Dike, Bronstein, Roberts & Cushman, Intellectual Property Practi
Larson Lowell A.
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