JPH11216521A - Curling method of punching material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a curling method of the punching material in producing a vessel with a curled peripheral margin using a punching material. SOLUTION: The first bent part 4 is formed by bending the tip edge of a periphery part 3 to be curled of a compact 1 in the obtuse angle state with a narrow cross section width to one side. Then, after the periphery part 3 which being curled inward from this bent part is bent further in the same direction in almost right-angled state, the curled bent part is formed and finished by being bent along the periphery part 3. By this simple method, the safe curl can be formed without having a defect such as the coil breaks due to the punch hole 2 and the like on the finished plane.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for curling a punching material when manufacturing a container having a curled peripheral portion using the punching material.

[0002]

2. Description of the Related Art For example, when manufacturing a cooking sieve using a punching material, as shown in FIG. 2A, a molded body having a punch hole 12 and formed into a predetermined shape by press molding or the like. As shown in FIG. 2B, a ring-shaped metal band 14 having no punch hole obtained in advance is abutted on the peripheral portion 13 of the coil 11 so as to overlap, and a top 15 of the winding machine is formed. The metal band 14 is brought into contact with the outer periphery of the upper surface of the peripheral portion 13 of the molded body 11 by using, and is bent so as to surround the peripheral portion 13 to cover the peripheral portion 13, and the leading edge of the peripheral portion 13 is caulked. They were wrapped round and protected safely.

[0003]

In this method, it is necessary to separately prepare a band having no punch hole, and a portion covered with the band may be loosened during use. Although not shown, as a means for solving this problem, a method of directly curling the peripheral portion of the main body with a frame of the same winding machine using a similar winding machine can be considered, but since the punching material has holes, If this is curled, it will cause the board to break,
Since the curling is not performed uniformly and the finished surface becomes uneven, and there are problems in terms of safety and quality, it has been necessary to adopt the method using the above-mentioned band. The inventor of the present invention has completed the curling method of the punching material of the present invention as a result of intensive studies in view of the problem of the method using the metal band.

[0004]

That is, a first aspect of the present invention is to form a molded article obtained by using a punching material by bending a leading edge of a peripheral edge having a predetermined width into one side with a narrow sectional width at an obtuse angle. To form a first bent portion, and then to form a second bent portion by bending the inward edge portion of the first bent portion further in the same direction at a substantially right angle. A curling method for a punching material, characterized in that the material is finished into a curled bent portion along a peripheral portion.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The method for curling a punched material according to the present invention comprises the steps of:
First, one side is bent at an obtuse angle with a narrow cross-sectional width to form a first bent portion, and then a peripheral portion which is inwardly inward from the first bent portion is further bent in the same direction at a substantially right angle. After forming the second bent portion, the first and second bent portions are bent along the peripheral edge to form a curled bent portion and finish. There is no particular limitation on the material of the punching material used and the size of the punch hole, and a molding machine for curling can be easily formed using a general-purpose press die.

[0006]

According to the method of curling a punched material of the present invention, a first bent portion is formed by bending a leading edge of a peripheral portion of a molded product, which is to be curled, into an obtuse angle with a narrow sectional width on one side. The bent portion is bent in the same direction by bending the peripheral portion further inward in the same direction to form a second bent portion, and the bent portion is formed into a curled shape. Thus, it is possible to form a safe curl without obstacles such as hip breakage.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below more specifically with reference to the accompanying drawings. In FIG. 1A, reference numeral 1 denotes a molded body having a predetermined shape obtained by molding using a punching plate, reference numeral 2 denotes a punch hole formed in the molded body 1, and reference numeral 3 denotes a formed body. It is a peripheral portion extending in the horizontal direction. The peripheral portion 3 of the molded body 1 forms curls in the following order using a general-purpose press die (not shown).

First, a first bent portion is formed by bending the distal end edge 4 of the peripheral edge portion 3 at one side (lower side in the figure) where a curl is to be formed at a relatively narrow sectional width at an obtuse angle. Since the bending is performed at a shallow bending angle that forms an obtuse angle, the bending can be uniformly and smoothly maintained at a predetermined bending angle without causing a hip break or the like in the punch hole 2 due to the bending.

Next, as shown in FIG. 1B, the peripheral portion 3 which has entered the first bent portion 4 formed on the peripheral portion 3 (indicated by the same reference numeral as the front edge 4 for convenience of explanation). Is bent substantially at right angles in the same direction (downward in the figure) to form a second bent portion 5. As a result, the first bent portion 4 comes into a shallow state toward the lower surface side of the substantially left horizontal peripheral portion 3.

From this state, as shown in FIG. 1C, the first bent portion 4 and the second bent portion 5 are put together to carry out the final press forming, whereby a highly safe curl 6 is formed. Can be formed.

[0011]

The method for curling a punching material according to the present invention comprises:
The leading edge of the peripheral portion of the molded article, which is to be curled, is bent to one side at an obtuse angle with a narrow cross-sectional width to form a first bent portion.
A very simple method of forming a second bent portion by sequentially bending the peripheral portion that has entered inside from the bent portion in the same direction at a substantially right angle, and then finishing these bent portions in a curled shape, provides an extremely simple method. It is possible to form a curl excellent in quality and safety without obstacles such as buckling due to punch holes.

In this method, since the formed body itself formed of a punching material is processed, it is possible to easily form a curl with a smaller number of parts as compared with the conventional rim winding method by attaching the band. It is excellent in that it can.

[Brief description of the drawings]

FIG. 1A is a diagram illustrating a first method of curling a punching material according to the present invention.
It is a longitudinal cross-sectional view which shows the procedure of.

FIG. 1B is a vertical sectional view showing the second procedure.

FIG. 1-c is a longitudinal sectional view showing a finished state.

FIG. 2A is a longitudinal sectional view showing a first procedure of a conventional edge winding method.

FIG. 2B is a longitudinal sectional view showing the second procedure.

FIG. 2C is a longitudinal sectional view showing the finished state.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 11 Molded body 2, 12 Punch hole 3, 13 Peripheral part 4 1st bending part 5 2nd bending part 6 Curl 14 Metal band 15 frames

Claims (1)

[Claims] 1. A first bent portion is formed by bending a leading edge of a peripheral edge having a predetermined width of a molded body obtained by using a punching material at a narrow cross-sectional width to one side at an obtuse angle, and then forming the first bent portion. Forming a second bent portion by further bending the peripheral portion that has entered inside from the bent portion in the same direction at a substantially right angle, and then finishing both of the bent portions into a curled bent portion along the peripheral portion. A method for curling a punching material.