JPS6324778B2 - - Google Patents

Description

[Detailed description of the invention] TECHNICAL FIELD The present invention relates to an improvement in a ring manufacturing method.

Recently, there has been a demand for hollow rings due to resource conservation and rising metal costs.

To manufacture a hollow ring, generally the left and right sides of the thin strip 1 shown in FIG. 1a are bent in the same direction as shown in FIG. The ends of both sides are bent inward into an L shape as shown in Figure c to form a hollow flat shape, and then this hollow flat material 3 is cut to a desired length and bent into a circle as shown in Figure d. Ring 5 with seam 4 in the axial direction
After that, the seam 4 of this ring 5 is
It was brazed to form a flat hollow ring 5'.

However, this ring manufacturing method, in which a ring with an appropriate cross-sectional shape is made from thin strip material 1 and the joints of the rings are brazed, may cause gaps due to unevenness in the joints, discoloration, or corrosion in the brazed parts. It is something that occurs. Further, even if it is desired to reduce the thickness of the band material 1, it cannot be made very thin considering brazing properties, and if the thickness is 0.3 mm or less, it cannot be brazed and a hollow ring cannot be made.

The present invention has been made to solve these problems, and aims to provide a method for manufacturing a hollow ring that is seamless, has a thin plate thickness, and has an appearance similar to that of ordinary products.

The ring manufacturing method of the present invention includes cutting a pipe,
The feature is that the upper and lower ends of the cut piece are folded back inward to create a hollow ring.

The details will be explained below with reference to the drawings. As shown in FIG. The upper and lower ends 7a and 7b are sequentially folded inward by flat drawing as shown in figures c to g, and finally folded back symmetrically as shown in figure h to form a flat hollow ring 8.

In addition, to make this flat hollow ring, cut piece 7
The upper and lower end portions 7a, 7b may be manufactured by press processing or processing using a pressure edge machine and a press machine in combination. Further, the hollow ring manufactured by the ring manufacturing method according to the present invention is the flat hollow ring 8 described above.
The present invention is not limited to this, but a round-shaped hollow ring 8' as shown in FIG. 3a may also be used. Also flat type,
In any of the hollow rings of the instep round shape, the inner folded portions may be pressed up and down to eliminate gaps as shown in Figure 3b, or the inner folded portions may be made smaller to eliminate gaps as shown in Figure 3c. The gap may be made larger, and if further reinforcement is required, the tip of the inner folded portion may be supported by coming into contact with the inner surface of the outer surface portion, as shown in FIG. 3d.

As mentioned above, the ring manufacturing method of the present invention involves cutting a pipe and folding both the upper and lower ends of the cut piece inward to make a hollow ring.Therefore, there is no seam, and there is no discoloration or corrosion caused by brazing. It is possible to easily manufacture even thin plates that cannot be brazed.

Next, in order to clarify the effects of the ring manufacturing method of the present invention, specific examples and conventional examples thereof will be described.

Example A pipe 6 made of Pt with a thickness of 0.2 mm and a diameter of 22 mm as shown in Fig. 2 a is cut into a length of 11 mm.
Next, the upper and lower ends 7a and 7b of this cut piece 7 are sequentially folded inward by flat drawing process as shown in Figures c to h to obtain a cut piece 7 with a height of 5 mm and a thickness of 1 mm. Gap between upper and lower folded parts 2
A flat hollow ring 8 with an inner diameter of 20 mm was made.

Conventional Example The left and right sides of a strip material 1 made of Pt with a thickness of 0.2 mm and a width of 11 mm as shown in Fig. 1 a are bent by 3 mm in the same direction as shown in Fig. b to form a cross-sectional groove shape of 5 mm in width. Next, the tips of both sides of this grooved material 2 are bent inward into an L shape as shown in Figure c to form a hollow flat shape with a thickness of 1 mm and a gap of 2 mm between the left and right folded parts. 3 is cut into a length of 67 mm and bent into a circle as shown in Figure d to form a ring 5 with a seam 4 in the axial direction.
Brazed as shown in Figure e to a diameter of 22 mm and an inner diameter of 20 mm.
A flat hollow ring 5' was made.

However, when we inspected 10 hollow rings each of the example and the conventional example made as described above, it was found that the hollow ring 8 of the example had no seams and was a flawless ring with an appearance equivalent to that of a normal product. All 10 of the conventional hollow rings 5' had gaps due to the difference in level at the seam 4, and the brazed parts were discolored, so they had no commercial value as rings.

As detailed above, according to the ring manufacturing method of the present invention, there is no seam even in the case of an extremely thin plate of 0.3 mm or less, and a hollow ring with the same appearance as a regular product can be easily manufactured. effective.

In addition, the amount of metal used can be significantly reduced, manufacturing can be done at low cost, and the product value can be increased. Moreover, since the board thickness can be made as thin as 0.3 mm or less, it becomes possible to add a hole-cut watermark pattern, providing decorative properties, as well as improving air permeability and preventing fingers from getting stuffy. It's also effective.

[Brief explanation of the drawing]

FIGS. 1a to 1e are perspective views showing steps in a conventional method for manufacturing a hollow ring, FIGS. 2a to 2h are sectional views showing steps in an embodiment of the method for manufacturing a ring according to the present invention, and FIG. 3a , b, c, and d are cross-sectional views showing other examples of hollow rings manufactured by the ring manufacturing method according to the present invention. 6... Pipe, 7... Cut piece, 7a, 7b...
Both upper and lower ends of the cut piece, 8...flat hollow ring,
8'...A round-shaped hollow ring.

Claims (1)

[Claims] 1. A method for manufacturing a ring, which comprises cutting a pipe and folding both the upper and lower ends of the cut piece inward to make a hollow ring.