JPH0818084B2 - Method for manufacturing metal products having arcuate portions at both corners - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a bending process for forming a flange portion in a state where there are no cuts at both corners of a web portion from a metal plate, for example, a large size having a flange portion on the entire circumference. Also relates to a method for producing a metal product having arcuate portions at both corners, the final processing of which can be performed by a small press machine.

[Conventional technology]

Conventionally, from a single metal plate, for example, a panel 3 shown in FIG.
As described above, in order to manufacture a metal product having a shape in which the flange portion 3b having no cuts is provided on the peripheral edge of the web portion 3a, the metal plate is drawn at once with a drawing die equipped with a die and a punch matching the shape and size of the product. Was drawn and processed.

However, in such a method, the shape of the metal product,
It is very uneconomical because it requires a mold that matches each shape for each different size, and a large press machine corresponding to that size is required to manufacture a large panel. Therefore, depending on the size, it may not be possible to manufacture by such a method.

[Problems to be solved by the invention]

The present invention does not have the above-mentioned drawbacks of the prior art and does not require a separate mold for final drawing when the arc-shaped portions at both corners have the same shape, and can easily manufacture a large-sized one. It is an object of the present invention to provide a method for producing a metal product having arc-shaped portions at both corners that can be formed.

In order to achieve this purpose, as shown in FIG. 7, the peripheral portion of one sheet of metal plate 4 is formed by straight portions 4a, 4c, 4e, 4g and corner portions 4b, 4d, 4g.
By dividing into f and 4h and separately processing the straight portion and the corner portion, it is considered that a mold of the same size as the product is not necessary. Therefore, when V bending is performed with a V-shaped die having a V groove and a V-shaped punch in the straight portion and drawing processing is performed in the corner portion, a remarkably conspicuous machining discontinuity occurs at the boundary between adjacent sections, and the appearance Could not be a good product. As described above, there is a problem that is difficult to solve by separately processing the straight portion and the corner portion so that the boundary between them is not conspicuous.

[Means for solving problems]

According to the present invention, when a straight portion is V-bent, a die and a punch having a specific shape are used to approach both corners, and the degree of bending is gradually loosened to be incompletely bent. It was made by clarifying that the above-mentioned problems can be solved by separately drawing each part.

That is, according to the present invention, the V-shaped groove has a constant opening angle and a constant depth and is smoothly continuous to the V-shaped groove of the fixed-shaped groove portion, the opening angle of the V-shaped groove is larger than that of the fixed-shaped groove portion, and the upper end is separated from the fixed-shaped groove portion. Accordingly, a straight V formed by the groove deforming portions which are formed to be inclined downward and constitute both ends of the V groove.
A straight line portion other than the portion included in the corner portion of the bending line along the edge of the metal plate is positioned in the fixed groove portion of the V groove of the V-shaped die having the groove, and the corner portions are formed on both sides of the V groove. Pressing by operating the V-shaped punch in the state of being positioned in the groove deforming portion is carried out for each bending line having arcuate portions at both corners to form a press middle portion in which the corners are left in an incompletely bent state. The present invention relates to a method for producing a metal component having arcuate portions at both corners, which is characterized by drawing the unfinished corners of the pressed intermediate product later to form the finished corners.

[Description of configuration]

Hereinafter, a method for manufacturing a metal product having arcuate portions at both corners according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is a perspective view schematically showing an example of a set of V-type dies and V-type punches which form the main part of the primary press used in the present invention, and FIG. 2 is a perspective view of the V-type dies of FIG. Fig. 3 is a plan view, Fig. 3 is a perspective view showing a main part of an example of a secondary press machine for drawing a corner, and Fig. 4 is a straight part of two edges sandwiching one corner of a metal plate. FIG. 5 is a perspective view of a press intermediate product bent after the primary press, and FIG. 5 is a perspective view of a metal product after the corner portions of the press intermediate product of FIG. 4 have been drawn.

In the method of the present invention, first, a linear portion other than the portion included in the corner portion of the bending line that sandwiches the corner portions of the arc to be bent of the bending line along the edge of the metal plate V-bending is performed using a die and a punch, and the corners of both corners are gradually relaxed from the straight side toward the end, and then bent to an incomplete state to obtain a press intermediate product. To obtain such a press intermediate product, a primary press machine described below is used.

The main part of the primary press comprises a V-shaped die 1 and a V-shaped punch 2 as shown in FIG. The opening angle θ of the V groove 1a provided in the V-shaped die 1 is the bending angle of the peripheral portion of the metal plate 4, for example, the web portion 3a and the flange portion shown in FIG.
It corresponds to the angle formed with 3b and is 90 ° in most cases, but it may take an angle other than 90 ° depending on the workpiece. The V groove 1a of the V-shaped die 1 has a bottom portion 1aa extending along a straight line, and the fixed groove portion 1a has a constant opening angle θ and depth of the V groove 1a.
b and the both ends of the V groove 1a of the fixed groove portion 1ab are smoothly continuous, and the opening angle of the V groove is the opening angle θ of the fixed groove portion 1ab.
Grooves which are formed in a shape that is larger and whose upper end is inclined downward as it moves away from the fixed groove portion 1ab and whose depth becomes shallower as it moves away from the fixed groove portion 1ab and that constitutes both end portions of the V groove 1a. It consists of a deformable part 1ac. Standard groove 1ab
Then, the depth of the V groove 1a and the opening angle θ are constant, so that the upper edge of the side surface 1aba is along a straight line. Since the bottom portion 1aa of the V groove 1a is along a straight line, this groove deformation portion 1ac
The upper edge of the side face 1aca of the
As shown in the drawing, the V groove 1a is inclined downward and the horizontal interval of the V groove 1a is increased.
The side surface 1aca of c preferably has a curved surface. In the illustrated example, the depth of the V groove 1a is zero at the end of the V groove 1a, but this is not always necessary. 1 and 2
In the drawing, the boundary between the surfaces is shown as a solid line so as to be angular so as to be easily seen, but it usually has an appropriate curvature.

The V-shaped punch 2 and the V-shaped die 1 constitute one set of press dies, and the length is almost the same as the entire length of the V-shaped groove 1a, but the groove deformation of the V-shaped groove 1a of the V-shaped die 1 is performed. The portion facing the portion 1ac may be slightly shorter in length, and the shape of the tip may be the same as the shape of the V groove 1a of the fixed groove portion 1ab over almost the entire length, but the V groove 1a Groove deformation part 1a
It is preferable that the end portion of the portion facing c has a curved relief portion so that the incompletely bent state of the metal plate is even more incomplete.

First, the section of the bending line of the metal plate 4 will be described. The shape of a metal product with arcuate parts at both corners is a triangle,
Although a polygon such as a pentagon can be adopted, for example, a right-angled quadrilateral in which four corners are arcuate as shown in FIG. 7 will be described as an example. The bending line set along the periphery of the metal plate 4 is
Corner bend lines Lb, Ld, L included in the arc-shaped corners
It is divided into f, Lh and linear bending lines La, Lc, Le, Lg which are parts other than the part included in the corner part of the linear bending line along the straight edge. . Although the shape and size of the bend of the bending line at the corner of the web 3a of the metal plate 4 varies depending on the product design, the bending of the bending line is almost a perfect circle as shown in FIG. If the radius is R, the radius R is usually a very small value of several mm to ten and several mm. The length of the subsequent straight bending line may be properly selected within the range of R × (3 to 20).

For example, the corner portions 4d and 4f of the metal plate 4 are formed by using the primary press machine having the V-shaped die 1 and the V-shaped punch 2 as main parts.
In order to obtain a press intermediate product in which B is in an incompletely bent state, first, a straight bending line Le along the edges sandwiching the corners 4d and 4f is sandwiched.
The entire length is located on the bottom portion 1aa of the fixed groove portion 1ab of the V-shaped die 1 and the corner portions 4d and 4f are fixed groove portions 1a, respectively.
b The V-shaped punch 2 is actuated in the direction of the arrow in FIG. 1 to be V-bent while being positioned on the groove deformed portions 1ac at both ends, and then along the other edge including the portions to be the corner portions 4d and 4f. The straight bending lines Lc and Lg are also V-bent in the same manner as above. When the length of the straight bending line Le or Lg of the metal plate 4 is long in the above V bending press, the fixed groove portion 1ab of the V-shaped die 1 is used.
The part forming the above is manufactured in advance so that it can be divided into a plurality of parts, and the divided bodies are appropriately connected to each other to form a long fixed groove portion 1a.
Configure b. If the V-shaped punch 2 has a curved relief portion at the end of the V-shaped die 1 facing the groove deforming portion 1ac of the V-shaped die 1 as described above, Similarly, it is preferable that the central portion is preliminarily manufactured so as to be divided into a plurality of pieces, and the divided bodies can be appropriately connected.

When the V-bending press is performed as described above, straight bending lines Lc and Le
In and, the V-shaped die 1 is bent at the same angle as the opening angle θ of the V groove 1a by the fixed groove portion 1ab and the punch 2, but the corner portion
Due to the shape of the groove deformation portion 1ac, the bending angle of the portion 4d becomes smaller as it approaches the corner side, and the straight bending lines Lc and Le
The bends given from the two directions of and are combined to form the corner 4d, which is bent in an incomplete state.
Lg is bent at the same angle as the opening angle θ of the V groove 1a by the fixed groove portion 1ab of the V-shaped die 1 and the punch 2, but the corner portion 4f is curved depending on the shape of the groove deforming portion 1ac. The bending angle becomes smaller as it gets closer to the side.
Corners 4f are created by combining the bends given from two directions with Lg.
The portion to be bent is bent into an incomplete state as shown in FIG. 4 to obtain a press intermediate product 5 '.

In the method of the present invention, the corners 4d and 4f are bent in an unfinished state as described above, and then individually drawn so that the corners 4d and 4f have the shape of the completed corners. Of. For such drawing, a secondary press machine having a die and a punch that conform to the shape of the finished corner as main parts is used. Although a known secondary press machine may be used, the drawing process will be described by taking the one shown in FIG. 3 manufactured and used by the present inventors as an example. In order to perform drawing with a secondary pressing machine, first, align two already bent bending lines sandwiching a target corner portion of the press intermediate product 5 ′ with predetermined sides of the corner die 6. Place it. Sides 6a and 6b shown in FIG. 3 of the corner die 6 are press intermediate products 5 '.
Since it includes a corner portion and a linear bending portion following the corner portion, the flange portion bent by the straight bending line to form a predetermined angle θ, for example, 90 ° is also in contact with the side wall of the corner die 6. It is said. When the pressing cylinder is operated in such a mounted state and the punch mounting plate 11 attached to the tip of the cylinder rod 12 is lowered downward (in the direction of the arrow), the spring 10 is inserted on the lower surface of the punch mounting plate 11 via the spring 10. The press plate 9 attached by pressing presses the web portion of the press intermediate product 5'between the corner portion die 6 and the press intermediate product 5 '. Further, as the punch mounting plate 11 descends, the corner punch 8 enters between the corner die 6 and the support wall 7 to remove the corner cushion 8'supported by the die pin. The flat portion 8a 'and the flat portion 8a of the corner punch 8 sandwich the arcuate portion of the unfinished corner portion of the press intermediate product 5'and the unfinished corners on both sides of this arcuate portion are sandwiched. The linear portion of the portion is positioned so as not to be clamped in the recess 8b 'following the flat portion 8a' of the corner cushion 8 '. After that, further punch mounting plate 11
And the corner punch 8 is moved to the corner die 6 and the support wall 7.
When it enters between the corner die and the corner cushion 8'and the corner punch 8, the press intermediate product 5 ', which is clamped so as not to generate wrinkles, has a small bending angle, and thus the corner die 6 is formed. Since the edge of the unfinished corner which is separated from the side wall of the is narrowed down so as to be pressed against the side wall of the corner die 6, the metal product 5 bent at a predetermined angle as shown in FIG. 5 can be obtained. is there. At this time, escape due to the repulsive force given to the corner punch 8 by the edge of the press intermediate product 5'is prevented by the support wall 7. In FIG. 3 as well, the boundaries between the surfaces of the corner die 6 are shown by solid lines 6a, 6b, 6c to make the structure easy to understand, but they usually have an appropriate curvature. In particular, it is the principle that the part of the line 6c is almost in conformity with the bending shape at the corner of the bending line set on the metal plate 4, and the corresponding part of the corner punch 8 is also the same. . The above bending work may be performed on a desired corner portion.

〔The invention's effect〕

According to the method for manufacturing a metal product having arcuate portions at both corners according to the present invention described in detail above, since bending is performed by drawing at the corner bending line separately from bending at the straight bending line, bending If the shape of the arc-shaped portions at both corners of the product is the same, there is no need to manufacture another mold for the final drawing process. Since the bending at the corner bending line is performed only on one side of the metal plate, it can be performed by a small press machine. When the straight bending line is long, the portion forming the fixed groove portion of the V-shaped die. Also, the device is generalized by preliminarily manufacturing the central portion of the V-shaped punch so that it can be divided into a plurality of parts, and connecting the divided bodies appropriately to form a long V-shaped die and V-shaped punch. You can do it.

Moreover, when bending along the corner bending line, first, the bending angle is gradually reduced from the flange side, which is bent at a predetermined angle with the web side, along with the bending along the straight bending line. There is an incomplete bending state, and after that, the web side is constrained and drawn by drawing, so that the boundary between the bent portion at the corner bending line and the bending portion at the straight bending line is No discontinuity was found at all, and no discontinuity was found even on the straight bending line, and it is possible to obtain a panel of excellent quality, for example, as a panel used for an exterior or the like.

[Brief description of drawings]

FIG. 1 is a perspective view schematically showing an example of a set of V-type dies and V-type punches that form the main part of the primary press used in the present invention, and FIG. 2 is a schematic view of the V-type dies of FIG. Fig. 3 is a plan view, Fig. 3 is a perspective view showing a main part of an example of a secondary press machine for drawing a corner, and Fig. 4 is a straight part of two edges sandwiching one corner of a metal plate. Is a perspective view of a press intermediate product which is V-bent by a primary press, FIG. 5 is a perspective view of a metal product after the corner portions of the press intermediate product of FIG. 4 have been drawn, and FIG. FIG. 7 is a perspective view showing an example, and FIG. 7 is an explanatory view showing bending sections of a metal plate. In the drawing 1 …… V-shaped die 1a …… V groove 1aa …… bottom 1ab …… shaped groove 1aba …… shaped groove side 1ac …… groove deformed portion 1aca …… groove deformed side 2 …… V-shaped punch 3 …… Panel 3a …… Web part 3b …… Flange part 4 …… Metal plate 4a, 4c, 4e, 4g …… Straight part 4b, 4d, 4f, 4h …… Corner part 5 …… Metal product 5 ′ …… Press Intermediate product 6 …… Corner die 6a, 6b, 6c …… Boundary between surfaces 7 …… Supporting wall 8 …… Corner punch 8a …… Flat surface 8 ′ …… Corner cushion 8a ′… … Plane 8b ′ …… Concave 9 …… Presser plate 10 …… Spring 11 …… Punch mounting plate 12 …… Cylinder rod La, Lc, Le, Lg …… Linear bending line Lb, Ld, Lf, Lh… … Corner bend line

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Noriyuki Utsunomiya 3-4-1 Marunouchi, Chiyoda-ku, Tokyo Within Nisshin Steel Co., Ltd. (72) Tadaaki Omori 3-4-1, Marunouchi, Chiyoda-ku, Tokyo Nisshin Steel Co., Ltd. (72) Inventor Fumio Fujiwara 4-11-5 Hatchobori, Chuo-ku, Tokyo Tsukiboshi Kogyo Co., Ltd. (72) Inventor Kihachi Yamamoto 4-11-5 Hatchobori, Chuo-ku, Tokyo Moon Hoshi Kogyo Co., Ltd. (72) Inventor Shuetsu Tamura 4-11-5, Hatchobori, Chuo-ku, Tokyo Tsukiboshi Kogyo Co., Ltd.

Claims (1)

[Claims] 1. A V-shaped groove having a constant opening angle and a constant depth and smoothly connecting to the V-shaped groove of the fixed groove, the opening angle of the V-shaped groove being larger than that of the fixed groove, and the upper end being away from the fixed groove. Therefore, a fixed groove portion of the V groove of a V-type die having a straight V groove which is formed to be inclined downward and constitutes both end portions of the V groove is formed on the edge of the metal plate. The V-shaped punch is actuated and pressed while the straight line portion other than the portion included in the corner portion of the bending line is positioned and the corner portions are positioned in the groove deformation portions on both sides of the V groove. This is done for each bending line that has arcuate parts at both corners to make a press intermediate product in which the corners are left in an unfinished bent state, and then the unfinished corners of the press intermediate product are respectively drawn and completed. Metal having arcuate portions at both corners, characterized by having the shape of a corner Method for producing goods.