JPH09276934A - Method for pressing metallic sheet and die used for it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a method for pressing a metallic sheet to a desired shape in a low cost by using a metallic mold composed of a die and a punch having specific shapes. SOLUTION: The metallic sheet 4 is set on the dies 6, 7 and pressed the punch 3 downward. The metallic sheet 4 is pressed between the fixed die 6, the main surface of the movable die 7 and the punch 3. A prescribed part at both sides formed with a first pressing is bent by a prescribed angle to the center part and the center part is curved. The metallic sheet 4 worked with the first pressing is sent to a second pressing with an automatic sending device. The curving part at the center part of the metallic sheet is curved to the reverse direction with the second pressing so as to enclose a punch by pressing the metallic sheet 4 worked with the first pressing, with the punch.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for pressing a metal plate and a mold used for the method.

[0002]

2. Description of the Related Art Conventionally, when a metal plate is formed into a shape as shown in FIG. 9, the following press working has been used. In the first press working, as shown in FIG. 10, the punched metal plate 4 is formed with dies 106 and 107 and a punch 103.
Set between As the punch 103 is pressed, both sides of the metal plate 4 are squeezed between the punch 103 and the dies 106 and 107 to form a predetermined angle. The metal plate processed as described above has a shape as shown in FIG. The molded product processed by the first press working is sent to the second press working. In the second press working, as shown in FIG. 12, the metal plate having the shape shown in FIG. 11 is bent into a shape as shown in FIG. 9 by pressing the punch 110 to bend the bottom so as to wrap the punch 110. According to the above-mentioned processing method, when the first press working is performed, the die and the punch are rubbed against the portion shown in FIG. In some cases, when the sheet is cut, the cut sheet remains in the mold and becomes a scratch due to a dent, or the press machine is stopped between the molded product and the mold in many cases. In order to solve the above-mentioned problems, lubricant oil has been used, and a mold having a complicated structure such as a cam type double-acting mold has been used.

[0003]

However, when a lubricant is used, degreasing is required, and a die having a complicated structure is disadvantageous in that the price is high and the die body is large. . Therefore, an object of the present invention is to provide a metal plate press working method capable of press working a metal plate into a desired shape at low cost, and a die used therefor.

[0004]

Means for Solving the Problems The present inventor has made intensive studies in order to solve the above-mentioned problems of the prior art. As a result, instead of simply bending both side portions of the metal plate at a right angle to the central portion as in the pressing step shown in FIG. 11, for example, a die and a punch having a special shape as shown in FIG. 3 are used. By pressing using a die, both side portions of the metal plate are bent at right angles to the central portion, and the central portion is curved, for example, into a semi-cylindrical surface, so that the metal plate can be processed. It has been found that it is possible to prevent scratches on both sides of the.
Further, the same effect can be obtained not only when the parts on both sides of the metal plate are bent at a right angle to the central part but also when bent at an angle other than a right angle. Furthermore, the same effect can be obtained not only when the central portion of the metal plate is curved into a semi-cylindrical surface shape, but also when it is curved or bent into an arbitrary shape as shown in FIG. The present invention was devised based on the above examination. That is, the method for pressing a metal plate according to the present invention comprises the steps of bending the predetermined portions on both sides of the metal plate 4 by a predetermined angle with respect to the central portion and bending the central portion by the first pressing, The step of bending the central portion of the metal plate 4 in the direction opposite to the bending direction of the first pressing by the above-mentioned pressing. In a typical embodiment of the method for pressing a metal plate according to the present invention, by the first press working, predetermined portions on both sides of the metal plate are bent substantially at right angles to the central portion, and the central portion is halved. Bend into a cylindrical surface. A mold according to the present invention has a movable member having a convexly curved surface and a fixed member provided adjacent to the movable member, and when the movable member descends from a reference position by a predetermined distance, the movable member moves. A die in which both side surfaces of the main surface of the member and the fixing member are inclined at a predetermined angle with respect to the main surface, and a concave portion whose bottom surface is curved in a convex shape is formed; A punch having a convex portion having a shape corresponding to the concave portion of the die on its main surface. A die according to the present invention has a concave portion on a main surface thereof, both side surfaces of the concave portion are inclined at a predetermined angle with respect to the main surface, and a bottom surface of the concave portion is convexly curved. And a punch having a convex portion having a shape corresponding to the concave portion on its main surface. According to the metal plate pressing method of the present invention configured as described above, by the first press processing, the predetermined portions on both sides of the metal plate are bent at a predetermined angle with respect to the central portion, and the central portion is curved. By doing so, it is possible to effectively prevent the portions on both sides of the metal plate from being scratched by the mold and the protective sheet from being cut during the first press working. And this 1st press process can be performed by using the metal mold | die by this invention.

[0005]

Embodiments of the present invention will be described below with reference to the drawings. The pressing method according to the embodiment of the present invention includes punching, bending (first pressing), and bending (second pressing), but the punching is omitted here. FIG. 1 is a sectional view of a metal plate 4 that has been punched. FIG. 2 is a perspective view of the metal plate 4 of FIG. FIG. 3 is a cross-sectional view showing a state where the metal plate 4 of FIG. 1 is set in a pressing device immediately before the first press working. In FIG. 3, 6 is a fixed die.
Is a movable die, and 3 is a punch. As shown in FIG. 3, in the pressing method according to the embodiment of the present invention, the metal plate 4 is set on the dies 6 and 7, and the punch 3 is pressed downward. The metal plate 4 is pressed between the main surface of the fixed die 6 and the movable die 7 and the punch 3 as shown in FIG. The predetermined portions on both sides formed by the first press work are bent at a predetermined angle with respect to the central portion,
In addition, FIG.
6 is a perspective view of the metal plate 4 of FIG. In the above case, in the first press working, the die 10 is conventionally used.
The punch 103 does not bend by bending the metal plate 4 perpendicular to the metal plate 4 with respect to 6 and 107, but bends predetermined portions on both sides at a predetermined angle with respect to the central portion and bends the central portion. (Figs. 5 and 6)
By adopting the shape of (3), the lowest point is a portion (Fig. 5-A) that forms a predetermined angle with the central part, and when pressure is applied from the punch 3, the lowest point is used as a reference, The portion bent at a predetermined angle (FIG. 5-B) is pressed against the die 6 in a plane. As a result, scratches caused by squeezing can be prevented. In addition, by curving the central portion, it is possible to maintain the predetermined angle required for the final processed shape. The metal plate 4 processed by the first press working is sent to the second press working by an automatic feeder, but the feeder is omitted here. In the second press working, as shown in FIG. 7, the metal plate 4 having the shape of FIG. 5 processed by the first press working is curved at the central portion of the metal plate so as to wrap the punch 10 by pressing the punch 10. The part is bent in the opposite direction and molded into the shape shown in FIG. With respect to each of the final processed shapes (FIG. 8), the same effect can be obtained by adjusting the shapes of the die and the punch to be subjected to the second press processing to the shapes of the above (FIG. 8). Further, the above-mentioned processing steps are the same for the case where the metal sheet is coated with the protective sheet, and the above-mentioned first pressing method has the effect of preventing the protective sheet from being peeled or cut.
FIG. 8 shows an example of a metal plate processed by changing the shapes of the die and punch of the second press working die.

[0006]

As described above, according to the present invention,
The metal plate can be pressed into a desired shape at low cost.

[Brief description of drawings]

FIG. 1 is a sectional view for explaining a press working method according to an embodiment of the present invention.

FIG. 2 is a perspective view for explaining a press working method according to an embodiment of the present invention.

FIG. 3 is a sectional view for explaining a press working method according to an embodiment of the present invention.

FIG. 4 is a sectional view for explaining a press working method according to an embodiment of the present invention.

FIG. 5 is a sectional view for explaining a press working method according to an embodiment of the present invention.

FIG. 6 is a perspective view for explaining a press working method according to an embodiment of the present invention.

FIG. 7 is a sectional view for explaining a press working method according to an embodiment of the present invention.

FIG. 8 is a cross-sectional view for explaining the press working method according to the embodiment of the present invention.

FIG. 9 is a perspective view for explaining a press working method according to a conventional technique.

FIG. 10 is a cross-sectional view for explaining a press working method according to a conventional technique.

FIG. 11 is a cross-sectional view for explaining a press working method according to a conventional technique.

FIG. 12 is a cross-sectional view for explaining a press working method according to a conventional technique.

[Explanation of symbols]

 1 Press Machine 2 Punch Support Member 3 Punch 4 Metal Plate 5 Positioning Member 6 Fixed Die 7 Movable Die

Claims (4)

[Claims] 1. A first press process bends predetermined portions on both sides of a metal plate at a predetermined angle with respect to a central portion, and
A metal plate, comprising: a step of bending the central portion; and a step of bending the central portion of the metal plate in a direction opposite to a bending direction of the first pressing process by a second pressing process. Stamping method. 2. The first press working is such that the predetermined portions on both sides of the metal plate are bent substantially at right angles to the central portion, and the central portion is curved into a semi-cylindrical surface. The method for pressing a metal plate according to claim 1, characterized in that. 3. A movable member having a convexly curved surface and a fixed member provided adjacent to the movable member,
When the movable member descends from the reference position by a predetermined distance, the entire main surface of the movable member and the fixed member, both side surfaces thereof are inclined at a predetermined angle with respect to the main surface, and
A die comprising: a die having a concave portion whose bottom surface is curved in a convex shape; and a punch having a convex portion having a shape corresponding to the concave portion of the die on its main surface. 4. A die having a concave portion on its main surface, both side surfaces of the concave portion being inclined at a predetermined angle with respect to the main surface, and a bottom surface of the concave portion being convexly curved. A die comprising a punch having a convex portion having a shape corresponding to the concave portion of the die on its main surface.