JP2010058142A - Method for press-forming cylindrical component with sharp edge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for press-forming a cylindrical metal component, capable of accurately forms a sharp edge on the metal component. <P>SOLUTION: In the method for press-forming a cylindrical metal component 1, in which a sharp edge 25 is formed on the inner peripheral edge where an open edge face 23 and an inner peripheral face 24 are crossed, a bottomed cylindrical part, which is shaped by sealing the open edge in the side to be sharp-edged, is firstly press-formed. The portion other than the open edge is press-formed so as to have the same shape as the cylindrical metal component as a final product. The bottom of the bottomed cylindrical part is press-blanked. Then, ironing is applied to a cut edge surface 22 of the bottomed cylindrical part a plurality of times to push out an excess metal to the open edge side, and crushing is applied to the open edge face 23 a plurality of times to push the excess metal therein, so that the sharp edge 25 is accurately formed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a press forming method for a cylindrical metal part in which an inner peripheral edge where an inner peripheral surface intersects with one opening end surface of the cylindrical portion is a sharp edge.

  As shown in FIG. 3, a cylindrical metal part having a tapered outer peripheral surface is known as a cylindrical metal part used as a part of a pipe connector. The cylindrical portion 2 of the cylindrical metal part 1 has a tapered surface with an outer diameter gradually increasing from one opening end toward the other opening end as a whole, and an inner peripheral surface 4 thereof. Is an inner circumferential cylindrical surface having the same diameter as a whole. The inner peripheral edge where one small-diameter opening end surface 5 of the cylindrical portion 2 and the inner peripheral surface 4 intersect is a sharp edge 6, and the outer peripheral edge of the opening end surface 5 is rounded so that the outer peripheral surface 3 is smooth. It is continuous. The inner peripheral edge of the other large-diameter opening end surface 7 has a tapered surface, and the outer peripheral edge thereof is rounded and smoothly continues to the outer peripheral surface 3. The width (thickness) of the small-diameter opening end face 5 may be as thin as 0.1 to 0.2 mm.

  The cylindrical metal part having such a shape is generally manufactured by lace processing, and the sharp edge 6 is attached with high accuracy. Further, quenching or the like is performed after the lace processing to increase the surface hardness of the open end portion where the sharp edge 6 is formed.

Here, Patent Documents 1 and 2 disclose a method of manufacturing a cylindrical metal part by press working. Patent Document 1 discloses a press forming method for a cylindrical metal part with a flange, and Patent Document 2 discloses a press forming method for a cylindrical metal part without a flange.
JP 2003-245730 A JP 2007-160359 A

  When manufacturing a cylindrical metal part with a sharp edge as shown in FIG. 1 by a conventional press forming method, there is a problem that the sharp edge cannot be formed with high accuracy. In particular, it is difficult to give a sharp edge to the inner peripheral edge of a thin opening end face of 0.2 mm or less by pressing. In addition, the open end with sharp edges requires work to increase the surface hardness by quenching in the subsequent process, so that there are many man-hours to manufacture, and cylindrical metal parts with shear edges cannot be manufactured efficiently. There is a point.

  In view of the above, an object of the present invention is to propose a press molding method for a cylindrical metal part capable of accurately attaching a sharp edge.

  Another object of the present invention is to propose a press forming method for a cylindrical metal part which can attach a sharp edge with high accuracy and can increase the surface hardness of the open end portion provided with the sharp edge.

In order to solve the above problems, the present invention provides a method for press-molding a cylindrical metal part in which the inner peripheral edge where the inner peripheral surface intersects with one opening end surface of the cylindrical part is a sharp edge.
A bottomed cylindrical shape having the same shape as the cylindrical metal component, except that the metal plate material is subjected to drawing and crushing processing, and the opening on the side where the sharp edge is formed in the cylindrical metal component is blocked. Forming part,
After that, press the bottom of the bottomed cylindrical part to form a cylindrical part with both ends open,
The cut surface portion after pressing the bottom of the inner peripheral surface of the cylindrical portion is subjected to multiple times of squeeze processing to make the cut surface portion a smooth inner peripheral surface, and the cut surface portion. Extrude the excess meat to the opening end face side of the cylindrical part,
Next, in a state in which movement of the meat toward the inner and outer peripheral surfaces is constrained, the opening end surface of the tubular portion is subjected to crushing multiple times so that the inner peripheral edge of the opening end surface becomes a sharp edge. It is characterized by being molded into

  In the press molding method of the present invention, in the step of attaching a sharp edge to the opening end of the cylindrical portion, the number of squeezing operations on the inner peripheral surface of the cylindrical portion and the crushing processing of the opening end surface of the cylindrical portion are performed. By controlling the number of times, the surface hardness of the open end of the cylindrical portion is adjusted.

  In the press molding method of the present invention, a bottomed cylindrical portion having a shape in which the opening end on the side to which the sharp edge is attached is sealed is first press molded. At this time, the portions other than the opening end are press-molded so as to have the same shape as the cylindrical metal part as the final product. After pressing the bottom of the bottomed cylindrical part, the inner peripheral edge of the opening end is squeezed and the inner periphery of the opening end is crushed multiple times, thereby sharpening the inner edge of the opening end. It is pressed so that

  In this way, after press-molding the shape other than the opening end, the bottom is removed to form the opening end, and the opening end is subjected to squeeze multiple times to extrude excess meat to the opening end side. On the other hand, a sharp edge can be formed with high accuracy by performing crushing multiple times and pushing in excess meat.

  In addition, by controlling the number of squeezing of the inner peripheral surface and crushing of the opening end face during the formation of sharp edges, the surface hardness of the opening end can be adjusted and desired without requiring a subsequent process such as quenching. An open end having a surface hardness of 5 mm can be formed.

  Embodiments of a press forming method for a cylindrical metal part to which the present invention is applied will be described below with reference to the drawings. The press forming method according to the present embodiment is for press forming the cylindrical metal part 1 having the shape shown in FIG.

  1 and 2 are explanatory views showing a press forming method of the cylindrical metal part 1. While the long metal plate 10 is intermittently sequentially fed along the conveyance path passing through each press working step, each press working region 11 of the metal member 10 is processed, and finally the cylindrical metal Part 1 is obtained.

  First, referring to FIG. 1, slitting is performed on a long metal plate 10 to form a disk-shaped press forming region 11 (blank) (steps 1, 2, and 3). Next, drawing is performed from the upper surface side to the lower surface side of the press-molding region 11 to form a circular recess 12 having a certain depth (steps 4 and 5), and thereafter drawing is performed from the upper surface and the lower surface side, A truncated cone-shaped bottomed cylindrical portion 13 is formed (step 6). The cylindrical portion 14 of the bottomed cylindrical portion 13 is a tapered surface with an outer peripheral surface 15 spreading upward, an inner peripheral surface 16 is a circular inner peripheral surface having a constant inner diameter, and an upper end is outward at an opening end. An annular flange 17 having a constant width is formed. The outer peripheral surface 15 and the inner peripheral surface 16 have the same shape as the outer peripheral surface and inner peripheral surface of the cylindrical metal part 1 that is a finished product.

  Next, the upper surface of the annular flange 17 of the bottomed cylindrical portion 13 is crushed, and the upper surface 18 of the portion on the large-diameter-side opening end surface 7 side of the cylindrical metal part 1 that is a finished product is applied. A shape is imparted (steps 7 and 8). As a result, the bottomed cylindrical part 20 having the same shape as the cylindrical metal part 1 which is a finished product is obtained except for the end part where the sharp edge is formed.

  After this, as shown in FIG. 2, a hole punching process for pressing the bottom of the bottomed cylindrical portion 20 is performed (process 9). By this punching, a cylindrical portion 21 having both ends opened is obtained. A cut end face (fracture surface) 22 remains at the lower end portion of the inner peripheral surface 16 in which the hole is formed in the cylindrical portion 21. The cutting end face 22 is squeezed twice to finish the cutting face 22 into a smooth surface having the same diameter as the other inner peripheral surface portions (steps 10 and 11). By these squeaking processes, excess meat is pushed out to the opening end face 23 side of the cylindrical body 21.

  Thereafter, the crushing process is performed twice on the opening end surface 23 in a state where the inner and outer surfaces of the cylindrical portion 21 are constrained (steps 12 and 13). As a result, the sharp edge 25 (6) is accurately formed at the inner peripheral edge where the inner peripheral surface 24 and the opening end surface 23 intersect. Further, a rounded surface is provided between the opening end surface 23 and the outer peripheral surface 26.

  Here, the number of squeeze openings for the inner peripheral surface portion continuous to the opening end face 23 and the number of crushing processes for the opening end face 23 are not limited to two, and may be three or more. Further, by repeatedly performing these processes on the opening end, the surface hardness of the opening end can be increased. Therefore, by controlling the number of times of these processes, an open end having a desired surface hardness can be formed, and there is no need to increase the surface hardness by post-processing such as quenching.

  Next, after the sharp edge 25 is formed, the annular flange 27 of the cylindrical portion 21 is pressed and removed from the metal plate 10 (step 15). Thereby, the cylindrical metal component 1 is obtained. After this, scrap cutting is performed on the portion of the metal plate 10 after being removed (step 16).

(Other embodiments)
The above example relates to a press forming method of a cylindrical metal part having the shape shown in FIG. The target metal part may be a cylinder other than a cylinder, for example, a polygonal cylinder such as a quadrangle. In the above example, the outer peripheral surface is a cylindrical metal member having a tapered inner surface and the inner peripheral surface is a circular inner peripheral surface having the same inner diameter, and the outer peripheral surface and the inner peripheral surface are both tapered. Metal parts can also be manufactured by the press molding method of the present invention.

It is explanatory drawing which shows the press molding method of the cylindrical metal component to which this invention is applied. It is explanatory drawing which shows the press molding method of the cylindrical metal component to which this invention is applied. It is a half sectional view showing an example of a cylindrical metal part that can be manufactured by the press molding method of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylindrical metal part 2 Cylindrical part 3 Outer peripheral surface 4 Inner peripheral surface 5 Open end surface 6 Sharp edge 7 Open end surface 10 Metal plate material 11 Press-forming area | region 12 Concave part 13 Bottomed cylindrical part 15 Outer peripheral surface 16 Inner peripheral surface 17 Circle Annular flange 20 Bottomed cylindrical part 21 Cylindrical part 22 Cut end face 23 Open end face 24 Inner peripheral face 25 Sharp edge 26 Outer peripheral face 27 Annular flange

Claims (2)

In the press molding method of the cylindrical metal part in which the inner peripheral edge where the inner peripheral surface intersects with one opening end surface in the cylindrical part is a sharp edge,
A bottomed cylindrical shape having the same shape as the cylindrical metal part, except that the metal plate material is subjected to drawing and crushing processing, and the opening on the side where the sharp edge is formed in the cylindrical metal part is blocked. Forming part,
Pressing the bottom of the bottomed cylindrical part to form a cylindrical part having both ends open,
The cut surface portion after pressing the bottom of the inner peripheral surface of the tubular portion is subjected to multiple squeeze processing to make the cut surface portion a smooth inner peripheral surface, and the excess of the cut surface portion. Extrude the meat on the side of the opening end face of the tubular part,
In a state where the inner and outer peripheral surfaces of the tubular portion are constrained, the opening end surface of the tubular portion is subjected to crushing a plurality of times, and the inner peripheral edge of the opening end surface is shaped to be a sharp edge. Press forming method for cylindrical metal parts with sharp edges. In the press molding method of the cylindrical metal part provided with the sharp edge according to claim 1,
In the step of attaching a sharp edge to the opening end of the cylindrical portion, the cylindrical shape is controlled by controlling the number of squeezing operations on the inner peripheral surface of the cylindrical portion and the number of crushing operations on the opening end surface of the cylindrical portion. A method for press-molding a cylindrical metal part having a sharp edge, wherein the surface hardness of the opening end of the part is adjusted.

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