JPH0241106A - Manufacture of precious metal chain for decoration - Google Patents

Abstract

PURPOSE:To improve the soldering strength of a connection of bent frame having small spring-back by cutting off a precious metal tape material having a specified sectional area, bending and forming it in the square-shaped form to prepare the frame while knitting the frames sequentially into a chain and then soldering and finish polishing the connection of bent frame. CONSTITUTION:A precious metal or precious metal alloy tape material having a sectional area smaller than that of the thickness dimension of the thickest portion multiplied by the width dimension of the widest portion, for example Au tape material 1 having a flat trapezoidal section having 0.15mm thickness, 0.33mm upper side width and 0.53mm lower side width is cut to 2.5mm length, bent and formed in square-shaped form to having 0.85mm sides to prepare box-shaped frames 2 while sequentially knitting the frames into a precious metal chain 5 for decoration. Then said chain is put in an electric furnace to solder the connection 4 of each bent frame 2 at 650-850 deg.C of soldering temperature. To remove the surplus solder from the connection 4, said chain is polished by a centrifugal barrel machine for 10 minutes and burnished by a buffing machine.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for manufacturing decorative precious metal chains such as bangles, necklaces, etc.

(Prior Art) Conventionally, in order to manufacture a decorative precious metal chain, a tape material 1' made of a precious metal or a precious metal alloy is cut to a required length as shown in FIG. Pieces 2' are formed by bending and forming the pieces into a character shape, and the pieces are successively interlinked to knit a decorative precious metal chain 3' as shown in FIG. 2C.

(Problems to be Solved by the Invention) The ornamental precious metal chain 3' thus knitted has a bending joint 4' in each piece 2'. If this bent joint 4' is not brazed, it will not have sufficient tensile strength and will easily break when worn. In particular, it may be difficult to braze materials with high material hardness. This is because when the piece 2' is made by bending the cut tape material 1' into the shape of an opening, the bent joint 4' will open due to springback as shown in Figure 3, so if it is brazed, As shown in FIG. 4, only a portion of the tape material 1' was brazed to the wall thickness, and the chain 3' did not have sufficient tensile strength.

In addition, in the conventional manufacturing method, after the bending joint 4' is brazed, the corners of each piece 2' of the chain 3' are cut as shown in Fig. 2d, so that a visually beautiful decoration can be obtained. However, the cutting process required skill and produced a large amount of precious metal scraps, causing problems such as recovery losses. In addition, the curls caused by the cut may make it uncomfortable to wear.

Therefore, according to the present invention, it is possible to make a piece with small springback, and therefore, a piece with sufficiently high strength can be obtained by brazing the bending joint, and also has sufficient decorativeness without cutting work, so that it can be worn easily. The purpose of the present invention is to provide a method for making a decorative precious metal chain that is comfortable to wear.

(Means for Solving the Problems) In order to solve the above problems, the method for manufacturing a decorative precious metal chain of the present invention has a cross-sectional area smaller than the thickness dimension of the thickest part multiplied by the width dimension of the widest part. Cut a tape material of a precious metal or a precious metal alloy with a cross-sectional area to the required size, bend it into a shape of a letter to make pieces, and then interlock them one after another to weave a decorative precious metal chain. brazing,
It is characterized by a polished finish.

(Function) As described above, the method for manufacturing the decorative metal area of the present invention is to use a precious metal or precious metal alloy having a cross-sectional area smaller than the cross-sectional area obtained by multiplying the thickness of the thickest part by the width of the widest part. Since the tape material is used, the bending strength of the material is reduced, so when the pieces are made by cutting them to the required size and folding them into a square shape, pieces with small springback are obtained, and these pieces are sequentially made. When knitting ornamental precious metal chains in interlocking fashion, the folded joints of the pieces come into close contact, so when the folded joints are subsequently brazed, the joint area increases and the joint strength is increased. Brazing of the bending joints can be done by barrel polishing, electrolytic polishing, or puff polishing afterward to achieve sufficient decorativeness, and there is no cutting work required, resulting in a high yield, and the decoration is comfortable to wear. A precious metal chain is obtained.

(Example) An example of the method for manufacturing a decorative noble metal chain of the present invention and a conventional example will be described.

First, one embodiment will be described with reference to FIGS. 1A to 1C. 1st
As shown in figure a, the thickness is 0.15 mm, the upper side width is 0.33 beads,
A tape material l made of Au with a flat trapezoidal cross section with a width of 0.53 mm at the bottom is cut into 2.5 cm lengths, and as shown in Figure 1, it is bent and formed into a shape of 0.85 + nm on each side to form a box. The decorative precious metal chain 3 is knitted by making the shaped pieces 2 and interlinking them one after another as shown in Fig. 1C.Then, the decorative precious metal chain 3 is placed in an electric furnace and brazed at a temperature of 650 to 850°C. The bent joints 4 of each piece 2 were brazed. Then, in order to remove the excess brazing material from the joint 4, a centrifugal barrel machine is used to
After polishing for 0 minutes, polishing was performed by puff polishing.

Next, a conventional example will be explained with reference to FIGS. 2a to 2d.

As shown in Figure 2a, the thickness is 0.15 mm and the width is 0.53 mm.
The tape material 1' made of Au was cut to a length of 2.5 mm, and as shown in Fig. 2, the tape material 1' was bent and formed into a square shape of 0.85 mm on each side to form a box-shaped piece 2'. Decorative precious metals are interlinked as shown in Figure 2 C! 113' was knitted, and then the same process as in the previous example was performed.

Finally, the corner corner of each piece 2' of the ornamental precious metal chain 3' was cut using a diamond cutting tool as shown in FIG. 2d.

The tensile strength of each of five decorative precious metal chains 3.3' of the example and the conventional example having a length of 20 cm thus prepared was measured, and the results shown in the table below were obtained.

As is clear from the table above, the tensile strength of the decorative precious metal chains of the conventional examples varied widely from 12 kg/- to 36 kg/10 wTl, whereas the tensile strength of the decorative precious metal chains of the example varied from 39 kg/s (to 45 kg/-). The variation is small,
Moreover, it has a high average value of 42 kg, which means that it has a stable and strong tensile strength.

In the above example, tape material 1 with a flat trapezoidal cross section was used as the tape material with a cross-sectional area smaller than the cross-sectional area obtained by multiplying the thickness dimension of the thickest part by the width dimension of the widest part. The material is not limited to a tape material having a flat spindle-shaped cross-section, a flat drum-shaped cross-section, a flat wave-shaped cross-section, or the like.

(Effects of the Invention) As can be seen from the above explanation, according to the method of manufacturing a decorative blue metal region of the present invention, pieces with small springback can be made, and therefore the brazing of the bending joints of the pieces has sufficient strength. To obtain a decorative precious metal steel which can obtain a high quality product, has sufficient decorative properties without cutting work, is free from burrs, and is comfortable to wear.

Furthermore, according to the method for producing decorative precious metal steel of the present invention, the cross-sectional area of the tape material used is smaller than the cross-sectional area obtained by multiplying the thickness dimension by the width dimension, so the amount of precious metal bullion input can be significantly reduced. Can be done.

Furthermore, since no cutting work is required, there is no loss in collecting scrap materials, which improves productivity.

[Brief explanation of the drawing]

Figures 1a to 1C are diagrams showing the method for manufacturing decorative precious metal steel of the present invention, Figures 2a to d are diagrams showing the conventional method for manufacturing decorative precious metal steel, and Figure 3 is the bending of pieces by the conventional method. FIG. 4 is a diagram showing a state in which the joint portion is opened due to springback, and FIG. 4 is a diagram showing a state in which the bent joint portion of FIG. 3 is brazed.

Claims (1)

[Claims] 1. Cut a tape material of precious metal or precious metal alloy to the required size with a cross-sectional area smaller than the cross-sectional area obtained by multiplying the thickness dimension of the thickest part by the width dimension of the widest part, and fold it into a shape to form a piece. A method for manufacturing a decorative precious metal chain, which comprises making a decorative precious metal chain by sequentially interlinking the pieces, and then brazing the bent joints of the pieces and polishing them.