JPH02200314A - Simple radius bending method - Google Patents

Abstract

PURPOSE:To prevent defects like slipped flaws due to the shoulder of die and multistage foldings due to a preceding phenomenon by performing radius bending as leaving straight parts for edge bent flanges of the workpiece of a stainless steel plate, etc., according to the specified process. CONSTITUTION:At first, a plate spring 4 of which the width is wider than the width of open part 2A1 and the thickness is over the thickness of a work or the strength is over the tensile strength of the work is placed on the upside surface of the open part of a upward U-shaped die 2 or a channel. Then a workpiece 5 of the stainless steel plate, etc., is placed on that plate spring. In this case, the straight parts 5A for the edge bent flanges of the workpiece 5 of the stainless steel plate, etc., are left on both end parts. After that, the workpiece is pressed downward with the body of punch 3A from the upside surface of the work-piece 5 and is performed the radius bending as leaving both the straight parts 5A. As that result, the slipped flaws due to the shoulder of die are not made and the multistage foldings due to the preceding phenomenon are not generated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for round bending silver and metal workpieces used for parts that come into contact with the human body, such as interior and exterior hardware of buildings and kitchen appliance covers.

[Prior Art] Conventionally, the stainless steel round column 7 as shown in FIG. 1 has been manufactured by the following method.

In the figure, 7A and 7B are the semi-cylindrical parts of one side and the other, and 7A1,
7A1 is a joint between the semi-cylindrical portions 7A, and 7B1.7B1 is a joint between the semi-cylindrical portions 7B.

1. In the case of a radius processing method using multi-stage weighting, 2. In the case of a reduction mold 8, etc.

[Problems to be Solved by the Invention] The conventional techniques described above have the following problems.

1. In the case of the rounding method using multi-stage bending, a highly accurate mold is required, resulting in a large number of steps and high costs.

2. In the case of the linear machining method, the workpiece 8A will have sliding scratches 8A1, and if the die groove is deep, the workpiece 8A will be folded in multiple stages as the radius increases, as shown in FIG.

Furthermore, a mold must be manufactured depending on the size of the radius, and the purchase price is high.

The present invention has been devised in view of the above-mentioned problems of the prior art, and its purpose is to provide a device that can do the following.

1. There is a leaf spring between the die and the workpiece, so the shoulders of the die do not slip.

2. Due to the reaction of the leaf spring, the workpiece does not separate from the tip of the rounded punch during the bending process, and multi-stage bending (polygonal rounded corners) does not occur.

3. The mold manufacturing cost is low because the die is constant and the punch radius can be changed depending on the size of the radius.

4. Since the die can be an air vent type, the required tonnage for bending can be reduced.

[Means for Solving the Problems] In order to achieve the above object, the present invention is as follows.

That is, the method of the present application is a simple round bending method consisting of the following steps. A plate spring 4 that is wide and has a thickness greater than the plate thickness of the workpiece or a strong tensile strength is placed.

In the second step, a workpiece 5 such as a stainless steel plate is placed on the upper surface of the leaf spring 4.

In the third step, from the top surface of the workpiece 5 such as a stainless steel plate,
The workpiece 5, such as the stainless steel plate, is bent into a radius by pressing downward with a punch body having a substantially arc-shaped or semi-cylindrical shape, leaving a straight part for the bending flange.

[Function] With reference to FIG. 13, the present invention exhibits the following function.

For products with a large bending radius, there is a phenomenon in which the workpiece (workpiece) leaves the tip of the radius bunch during bending.

That is, that part bends shallowly, and as it progresses further, the bend propagates to the left and right around that position, forming a so-called polygonal rounded surface as shown in Figure 4. However, the leaf spring of the present invention can Due to the back pressure of the leaf spring, which has a strong tensile strength due to the workpiece, the tip of the round bunch does not leave the tip as shown in FIG. 13, and a well-shaped 7-round surface as shown in FIG. 9 can be obtained.

[Embodiments of the invention] Examples will be described with reference to the drawings.

Reference numeral 1 denotes a rounding tool suitable for carrying out the method of the present invention, which is composed of an upwardly U-shaped die 2 and a punch 3 configured to be freely inserted into and removed from the opening of the die 2.

The die 2 is composed of a bottom plate part 2A, and left and right wall plate parts 2B and 2C, which are made to stand upwardly on the left and right sides of the two bottom plate parts.

For this die 2, known channel steel can also be used.

2A1 is the width of the opening in die 2, 2B1.2C1
represent the heights of the inner walls of the left and right wall plate portions 2B and 2C, respectively.

The punch 3 is composed of a punch body 3A having a substantially arcuate or semi-cylindrical shape on the lower side, and a flat plate 3B implanted on the upper surface of the punch body 3A.

Also for this punch body 3A, a publicly known carbon steel pipe for piping can be used.

3A1 is the depth of the punch body 3^, and its dimension is equal to or smaller than the radius of the punch body 3A.

3A2 is the chord length of the punch body 3A, and its dimension is equal to or smaller than the diameter of the punch body 3A.

Since the length of the radius of 150-1 arc can be bent in 5 steps, the length of the chord is set to 1 so that the arcs may overlap somewhat.
It was set to 30m.

Commercially available channel steel 150 x 75 x 8 was used as the die.

In a preliminary test, a commercially available carbon steel pipe for piping with an outer diameter of 190 mg+ was cut to a chord length of 13 Gmm and used as Panchiar.

The *i radius bending method of the present invention using the curve tool 1 is as follows.

1J1 process A plate spring with a width wider than the width 2A1 of the opening and with a thickness equal to or greater than the thickness of the workpiece or with strong tensile strength is placed on the upper surface of the opening in the upward U-shaped die 2A5 or known channel steel. Place 4.

A workpiece 5 such as a stainless steel plate is placed on the upper surface of the second process plate spring 4.

In this case, straight portions 5A for end bending flanges of the workpiece 5 such as a stainless steel plate are left at both ends.

3rd step From the top surface of the workpiece 5 such as a stainless steel plate, punch body 3
Press downward with A to bend it into a radius, leaving the inner straight part 5A.

1°, 1" using a known method, Satsushi mold 6.
Bend 2° and 2". After this, bend the radius in the order shown in Figure @10 to get a good result.

[Effects of the Invention] Since the present invention is configured as described above, the following effects are achieved.

1. There is no slippage caused by the die shoulder.

2. Multi-step folding due to preceding phenomena does not occur.

3. If commercially available channel steel is used for the die, it is very inexpensive.

[Brief explanation of the drawing]

Figure 1 is a schematic cross-sectional view of a stainless steel round column, Figure 2 is a schematic longitudinal cross-sectional view of a conventional processing method, Figures 3 and 4.
The figure is a schematic vertical cross-sectional view explaining the problems with the conventional processing method, Figure 5 is a perspective view before processing according to the present invention, Figure 6 is a perspective view of the same during processing, and Figure 7 is a processing state. A vertical cross-sectional view for explaining, FIG. 8 is A-A
Figure 9 is a longitudinal cross-sectional view of the completed state, Figures 10, 11, and 12 are cross-sectional views explaining the state of flange right angle bending, and Figure 13 is a vertical cross-sectional view of the completed state. It is a longitudinal cross-sectional view explaining an effect|action. 100. R processing tool, 216. Dice, 393. Punch, 4. , leaf springs, stainless steel plates, etc. Figure knowledge figure figure figure

Claims (1)

[Claims] A simple radius bending method characterized by comprising the following steps. First step: A leaf spring 4 that is wider than the width of the opening and has a thickness greater than or equal to the thickness of the workpiece or has strong tensile strength is placed on the top surface of the opening in an upward U-shaped die or known channel steel. To do. Second step: Place a workpiece 5 such as a stainless steel plate on the upper surface of the leaf spring 4. 3rd step Press downward from the upper surface of the workpiece 5 such as a stainless steel plate with a punch body configured in a substantially circular arc shape or semi-cylindrical shape to form an end bending flange on the workpiece 5 such as a stainless steel plate. Leaving the straight part and bending it in a radius.