JP2001038447A - Molding method of cylindrical forging having bottom and convex part on side - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten a manufacturing time, while improving a material yielding and strength of a product, by stamping a cogging material and molding it into a cylindrical shape, having a bottom, with a backward extrusion die and by stamping the bottom part of the cylindrical mold with a vertical punching press for extrudingly molding a convex part at a bottom outside part. SOLUTION: A cup-like cylinder part 1' is molded by stamping a cogging material R of a given length, whose end verge is chamfered, with a backward extrusion die M1. The cup-like cylinder part 1' is stamped with a vertical punching press die M2 so as to mold it in a shape that a flange part 2' is extruded at outside part of the cylinder part 1'. A flash F is extruded at the flange part 2'. The flash F of the flange part 2' is removed with a trimming die M3 so that the cylinder part 1' having the flange part 2' outside is molded by forging. A finish processing is performed by a machine work to the cylinder part 1' and the flange part 2' to form a product.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for integrally forming a bottomed cylindrical product having a convex portion on a side surface, such as a flange protruding from an outer peripheral wall of a hydraulic or pneumatic cylinder, by forging. About.

[0002]

2. Description of the Related Art Conventionally, the following method has been employed to manufacture a product P having a shape in which a flange 2 protrudes from an outer peripheral wall of a cylinder 1 as shown in FIG. (1) As shown in FIG. 5, a method of manufacturing a product P shown by a virtual line by cutting a forged material R such as stainless steel having a predetermined length. (2) As shown in FIG. 6, a method of manufacturing a product P indicated by a virtual line by cutting a forged material R by forming a cylinder portion (solid) 1 ′ and a flange portion 2 ′ by lateral forging and cutting. . (3) As shown in FIG. 7, the forged material R is extruded rearward into a cup shape (so that it becomes a part of the cylinder portion 1 'in advance).
A method of manufacturing a product P indicated by a virtual line by cutting after forming. (4) As shown in FIG. 8, the forged material R is upset, the cylinder portion (solid) 1 ′ and the flange portion 2 ′ are formed by vertical forging, and then a product P indicated by a virtual line is manufactured by cutting. how to.

[0003] In the manufacturing method of the above (1), the forged material R of a round bar is used.
Cutting the inner part of the cylinder and the flange part of the outer peripheral wall of the cylinder requires a large amount of cutting, it takes a lot of time to manufacture, the material yield is poor, and the cutting cuts the Glenflow (grain flow line). Therefore, there is a disadvantage that the strength of the product is reduced. (2) and (4)
According to the method (1), the inner portion of the solid cylinder portion 1 'is cut out by cutting, so that there is a disadvantage similar to the method (1). Although the method (3) is improved over the methods (1), (2) and (4), the outer peripheral portion of the cylinder portion is also largely cut to form a flange portion. There is the same problem as in the above manufacturing method.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to improve the problems of the above-mentioned conventional manufacturing method, to provide a manufacturing method capable of improving the yield of materials and the strength of products and shortening the manufacturing time. is there.

[0005]

Means for Solving the Problems A step of stamping a forged material with a die for backward extrusion and forming it into a bottomed cylindrical shape, and stamping the bottom of the bottomed cylindrical molded product with a vertical stamping die. And forming a projection on the outer side of the bottom.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a method for forming a bottomed cylindrical forging having a convex portion on a side surface according to the present invention is shown in FIG.
This will be described with reference to the process diagrams shown in (a) to (g). First, a forged material (a bar material such as stainless steel) R having a predetermined length with a chamfered edge shown in FIG. 7A is stamped with a backward extrusion die M1 shown in FIG. ) A cup-shaped cylinder portion 1 'shown in the figure is formed.

Next, a vertical stamping die M2 shown in FIG.
By stamping the cup-shaped cylinder portion 1 ′, a flange portion 2 ′ is formed on the outside of the cylinder portion 1 ′ shown in FIG.
Into a shape protruding. Since the burrs F protrude from the flange portion 2 ', the cutting die M3 shown in FIG.
By removing the burrs F, a cylinder portion 1 'having a flange portion 2' on the outer side as shown in FIG. FIG. 2 is an enlarged detailed view of FIG. Then, the cylinder portion 1 ′ and the flange portion 2 ′ are subjected to finish processing by machining to become a product P shown by a virtual line, and a product P shown in FIG. 3 (a cylinder 1 having a flange 2 on the outer side) can be manufactured. .

[0008]

According to the present invention, by using two types of molds, the forming of the bottomed cylindrical portion and the forming of the convex portion projecting from the outer surface of the bottomed cylindrical portion are separated by forging. Since the molding is performed to approximately the size of the molded product, the yield of the material is improved as compared with the conventional manufacturing method. Also, since there are few parts to be cut, the production time of the product can be shortened,
Since the Glen flow of the metal structure is not cut, there is an effect that the strength of the product is not reduced.

[Brief description of the drawings]

FIG. 1 is a process chart showing an embodiment of a molding method according to the present invention.

FIG. 2 is a detailed explanatory view of a product before finish processing forged by the present invention. (A) is a side view, and (b) is a front sectional view.

FIG. 3 is an explanatory view of a product formed by the present invention. (A)
The figure is a side view. (B) The figure is a front sectional view.

FIG. 4 is an explanatory view of a product having a shape in which a flange is projected from an outer surface of a cylinder. (A) is a side view, and (b) is a front view.

FIG. 5 is an explanatory view of a conventional example of manufacturing the product shown in FIG. 4 by cutting. (A) is a side view, and (b) is a front view.

FIG. 6 is an explanatory view of a conventional example in which the product shown in FIG. 4 is manufactured by horizontal forging and cutting. (A) is a side view, and (b) is a front view.

FIG. 7 is an explanatory view of a conventional example of manufacturing the product shown in FIG. 4 by backward extrusion and cutting. (A) Figure is a side view,
(B) The figure is a front view.

FIG. 8 is an explanatory view of a conventional example in which the product shown in FIG. 4 is manufactured by upsetting, vertical stamping and cutting. (A) is a side view, and (b) is a front view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylinder 1 'Cylinder part 2 Flange 2' Flange part M1 Back extrusion die M2 Vertical press die M3 Punch die P Product R Forged material

Claims (2)

[Claims] 1. A step of stamping a forged material with a die for backward extrusion to form a cylinder with a bottom, and stamping the bottom of the cylindrical article with a bottom with a vertical press die to form the bottom. Forming a protruding portion on the outer portion by projecting the protruding portion. 2. A step of stamping a forged material with a die for backward extrusion to form a cylinder with a bottom, and stamping a bottom of the cylindrical article with a bottom with a vertical press die to form the bottom. A method for forming a bottomed cylindrical forged product having a convex portion on a side surface, comprising a step of projecting a convex portion on an outer portion and a finishing process by machining.