JPH09136247A - Precious metal grinding method, precious metal grinding tool, and ultrasonic grinding device provided with its tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily grind complicated parts and recessed parts and also grind without leaving any mark of grinding on the surface by grinding a precious metal containing at least one of gold, silver, and platinum while an ultrasonic vibration is given to a metal lower in hardness than the precious metal. SOLUTION: To use an ultrasonic grinding machine, an ultrasonic wave oscillator is started so as to give an ultrasonic vibration from the top end part 14a of a hand piece 14 to, for example, a copper round bar 11 of a grinding tool 10 through a holder 13, and the hand piece 14 is moved so as to press the top end of the round bar 11 lightly, for example, to a platinum precious metal. Then the top end of the round bar 11 is moved along the surface of the precious metal for grinding. Thus the platinum is ground with the copper round bar 11 with a hardness lower than it while ultrasonic vibration is given to it so as to easily grind complicated parts and recessed parts and also give remarkable luster to the surface of the platinum without using any abrasive grains.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a noble metal polishing method, a noble metal polishing tool, and an ultrasonic polishing apparatus having the same.

[0002]

2. Description of the Related Art A noble metal such as gold, silver or platinum, which is used as a base metal for rings and necklaces to which jewels are stone-fixed, is usually formed into a predetermined shape by a casting method. Therefore, extremely fine irregularities (casting surface) are formed on the surface of the precious metal due to the dried fine particles of gypsum used as a mold. When such irregularities are formed, the original luster (gloss) of the precious metal is lost, and the commercial value thereof decreases. Therefore, it becomes necessary to polish the surface of the cast noble metal to flatten the ultrafine irregularities so as to obtain gloss.

As one method of flattening the surface of a noble metal such as gold, silver or platinum, a tip portion 51 called "hand spatula" or "stick spatula" as shown in FIG.
There is a method in which a person directly polishes a noble metal by using a tool in which a is a rod made of cemented carbide or steel having a length of about 30 mm, and a body portion 51b having a length of about 15 cm is attached to the rod. The cemented carbide is mainly a powder of tungsten carbide that is sintered, and is an alloy that is much harder than precious metals. The reason why such cemented carbide or steel is used is that the surface of the noble metal can be flattened by crushing the projections of the extremely fine irregularities.

As another method, a rod made of cemented carbide is attached to a handpiece as a vibration source of an ultrasonic device via a tool holder, and noble metal is polished by utilizing strong vibration of ultrasonic waves. There is a method.

[0005]

However, since the former method is a manual method, a certain amount of space is required to move the "hand spatula" back and forth while strongly rubbing it against the precious metal. Therefore, it is easy to polish relatively wide and flat parts and convex parts, but it is difficult to grind fine and complicated parts and concave parts that are characteristic of precious metals such as rings and necklaces, and these parts cannot be polished sufficiently. There was a problem.

According to the latter method, the frequency is 25k.
Since the ultrasonic vibration with the frequency of 20 Hz and the amplitude of 20 to 40 μm is used, the polishing can be performed only by bringing the cemented carbide rod into contact and rubbing lightly. Therefore, the casting surface can be removed even in the intricate fine parts and concave portions can do. However, in this method, since ultrasonic vibration is applied through a very hard rod made of cemented carbide, it is possible to remove the casting surface and give gloss, but the surface of the precious metal is roughened and the precious metal is There are innumerable traces of cemented carbide rods left. Therefore, this method can be used only for a limited part of the details that are not so noticeable even if the above-mentioned traces remain. Furthermore, this method is said to be difficult to polish due to the shape of jewelry made of precious metal, for example, the intricate fine parts and recesses on the back side of a ring, because cemented carbide cannot be bent and used very hard. There was a problem.

Further, in any of the above-mentioned methods, polishing a noble metal for a long time damages the rod of cemented carbide having a high hardness, and if the scratch is left and polishing continues, the noble metal is scratched. Is transferred, and the gloss of the precious metal cannot be obtained. Therefore, there has been a problem that a very troublesome work such as grinding a cemented carbide with a grindstone such as diamond must be frequently performed to keep the cemented carbide free from scratches.

Therefore, an object of the present invention is to easily grind fine parts and concave portions of precious metal such as gold, silver or platinum used as a base metal for rings and necklaces and to polish the surface of the precious metal. It is an object of the present invention to provide a noble metal polishing method capable of performing polishing without leaving a trace, a noble metal polishing tool, and an ultrasonic polishing apparatus including the same.

Another object of the present invention is to relatively softly bend and use, and to easily grind intricate fine parts and recesses on the back side of jewelry such as rings made of precious metals. A polishing tool of noble metal capable of performing the above and an ultrasonic polishing apparatus provided with the same.

Still another object of the present invention is that even if a noble metal is polished for a long time, the tool itself is not damaged, so that no very troublesome work such as sharpening with a grindstone such as diamond is required at all. Another object of the present invention is to provide a polishing tool and an ultrasonic polishing device equipped with the same.

[0011]

In order to achieve the above object, a method for polishing a noble metal according to the present invention is a noble metal containing at least one of gold, silver and platinum, which has a hardness lower than that of the noble metal. It is characterized by polishing while applying ultrasonic vibration to the. In this way, by polishing a metal having a hardness lower than that of a precious metal while applying ultrasonic vibration,
The surface of the precious metal can be flattened (smoothed) without leaving scratches (polishing) on the precious metal, and the original beautiful luster of the precious metal can be obtained. Further, since ultrasonic vibration is used, it is possible to easily polish fine portions and concave portions of the noble metal without requiring any skilled technique. As in the present invention, a metal having a hardness lower than that of a noble metal can be used to polish the noble metal without leaving a polishing mark because the ultrasonic vibration causes the metal as the polishing means and the noble metal as the object to be polished to be relatively It is presumed that this is because the noble metal is impacted by a large acceleration due to ultrasonic vibration while being diffused and applied to a contact area having a large area. On the other hand, when ultrasonic vibration is applied through a rod made of cemented carbide, innumerable traces of the rod made of cemented carbide remain on the precious metal because the ultrasonic vibration causes the rod and the precious metal made of cemented carbide. It is presumed that this is because the noble metal surface is roughened by being concentratedly applied only to the very narrow contact point with.

The noble metal polishing tool of the present invention is made of gold,
A polishing tool for polishing a noble metal containing at least one of silver and platinum by ultrasonic vibration, comprising a polishing portion made of a metal having a hardness lower than that of the noble metal.

According to one aspect of the present invention, at least a part of the polishing portion is covered with a metal harder than the polishing portion. In this case, the polishing portion is reinforced, and even if ultrasonic vibration is applied to the precious metal through the polishing portion for a long time, the polishing portion may break or bend unnecessarily. There is no end.

As one aspect of the present invention, one end side of the polishing section is brazed to a metal rod harder than the polishing section. Even in this case, the polishing portion is reinforced, and even if ultrasonic vibration is applied to the precious metal through the polishing portion for a long time, the polishing portion may be broken or unnecessarily bent. There is no end.

As one aspect of the present invention, one end side of the polishing section is formed in a flat plate shape. In this case, since the polishing portion is geometrically reinforced by the width of the flat plate, even if ultrasonic vibration is applied to the precious metal through the polishing portion for a long time, the polishing portion may be broken, It will not be bent unnecessarily.

As one aspect of the present invention, one end side of the polishing section is curved. As a result, it is possible to easily polish intricate fine parts and recesses on the back side of jewelry such as precious metal rings.

In one aspect of the present invention, the metal having a hardness lower than that of the noble metal is copper. Thus, the reason why copper is used is that the polished portion is easily curved and is relatively inexpensive. In this specification, metals such as copper and platinum mean not only pure metals but also metals containing a very small amount of different metals.

In addition, the ultrasonic polishing apparatus of the present invention includes a polishing section for the above-mentioned noble metal, a holder for holding the polishing section, and an ultrasonic wave applying ultrasonic vibration to the polishing section via the holder. And a sound wave vibration source.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a view for explaining a first embodiment of the present invention, (a) is a perspective view of a noble metal polishing tool, and (b) is an ultrasonic wave with the polishing tool attached. It is a perspective view of a polishing device.

In FIG. 1 (a), a polishing tool 10 for polishing a noble metal has a copper rod 11 having a mirror surface and a diameter of 1.2 mm and a length of 40 mm, an inner diameter of 1.2 mm and a wall thickness of 0. 2 mm, 23 mm long, 0.3 mm wide slit 1
2a is formed on the stainless steel pipe 12. The round bar 11 is passed through a pipe 12, and the round bar 11 is reinforced by covering about half of its length with the pipe 12. Further, when a force is applied to the pipe 12 from the outside, the gap between the slits 12 a is narrowed, and the round bar 11 is fixed to the pipe 12.

As shown in FIG. 1B, the polishing tool 10 includes a holder 13 and a handpiece 1 for ultrasonic machining.
4 attached. The holder 13 is formed with a hole having a diameter substantially the same as the diameter of the pipe 12. Polishing tool 1
0 is held in the holder 13 by being inserted into this hole and screwed with a screw 13a.

The holder 13 is held on the handpiece 14 by being screwed together with the tip portion 14a of the handpiece 14.

The handpiece 14 is shaped and sized so that it can be grasped by one hand, and the cord 14b.
Is connected to an ultrasonic oscillator (not shown).
Thereby, the handpiece 14 can apply ultrasonic vibration to the copper rod 11 of the polishing tool 10 through the holder 13 from the tip portion 14a. In this embodiment, the ultrasonic vibration has a frequency of 25 kHz, an amplitude of 20 to 40 μm, and an output of about 40 W.

Next, the operation of this embodiment will be described. FIG.
To use the ultrasonic polishing apparatus shown in (b), an ultrasonic oscillator (not shown) is activated to start the tip portion 1 of the handpiece 14.
4a of copper round bar 1 of polishing tool 10 via holder 13
While applying ultrasonic vibration to 1, the tip of the round bar 11 is lightly pressed against a noble metal (not shown) made of platinum (for example, a ring, bracelet, necklace, etc.) by moving the handpiece 14. Then, polishing is performed while moving the tip of the round bar 11 along the surface of the precious metal. It should be noted that since noble metals such as platinum, gold, and silver as the objects to be polished have a low hardness when they are pure and are easily deformed or scratched, they are usually alloyed to have a high hardness.

As described above, in the present embodiment, platinum is polished while being ultrasonically vibrated by the copper round bar 11 having a hardness lower than that of platinum, so that fine parts and concave portions of platinum are easily polished. It is possible to give a very beautiful shiny luster to the surface of platinum without using abrasive grains. In addition, no polishing marks are left on the surface of platinum unlike when polishing with cemented carbide. Further, even if platinum is polished for a long time, the round bar 11 itself of the polishing tool 10 is not damaged, and therefore, it is not necessary to perform a very troublesome work such as grinding the round bar 11 with a grindstone such as diamond. However, since the hardness of copper is lower than that of platinum, if the polishing is continued for a long period of time, the tip of the round rod 11 will be rounded.

Next, second to fourth embodiments of the present invention will be described with reference to FIG.

FIG. 2A is a perspective view of a polishing tool 20 used in the second embodiment of the present invention. This polishing tool 20
Is different from the polishing tool 10 shown in FIG.
Regarding 0, it is only the point where the round bar 21 projects from both ends of the pipe 22, and the other points are the same. According to this embodiment, even if the tip of the round bar 21 is rounded due to long-term use, the other end can be used for polishing.

FIG. 2B is a perspective view of the polishing tool 24 used in the third embodiment of the present invention. This polishing tool 24
Is different from the polishing tool 10 shown in FIG.
With respect to No. 4, the tip 25a of the round bar 25 on the side projecting from the pipe 26 is processed into a flat plate shape by pressurization, and the other points are the same. According to this embodiment, the round bar 25 is formed by forming the round bar 25 into a flat plate shape.
However, even if the polishing tool 24 is used for a long period of time, the round bar 25 is hardly broken or unnecessarily bent.

FIG. 2C is a perspective view of a polishing tool 27 used in the fourth embodiment of the present invention. This polishing tool 27
Is made by brazing a copper polishing rod 28 and a brass, iron or stainless steel round rod 29. The brazing may be performed after making a hole in the end surface of the round bar 29 and inserting the bar 28 in this hole. According to this embodiment, since the copper rod 28 and the round rod 29 are brazed to reinforce the rod 28, the polishing tool 2
Even if 7 is used for a long period of time, there is an advantage in that the bar 28 hardly breaks or bends unnecessarily.

Next, regarding the fifth embodiment of the present invention,
It will be described with reference to FIG. 3, which is a perspective view of the ultrasonic polishing apparatus.

The ultrasonic polishing apparatus of this embodiment has a polishing tool 30 for polishing a noble metal, a holder 33 for holding the polishing tool 30, and a hand piece 34 for applying ultrasonic vibration. The polishing tool 30 has a diameter of 1.2 mm,
A round copper rod 31 with a length of 40 mm and a curved tip, an inner diameter of 1.2 mm, a wall thickness of 0.2 mm, a length of 23 mm and a width of 0.3
and a stainless steel pipe 32 in which a slit 32a of mm is formed. The structure of the polishing tool 30 is the same as that shown in FIG. 1 except that the tip of the round bar 31 is curved.
It is similar to that of (a).

As shown in FIG. 3, the polishing tool 30 is attached to a handpiece 34 for ultrasonic processing via a holder 33. The holder 33 is formed with a hole having substantially the same diameter as the diameter of the pipe 32. The polishing tool 30 is held in the holder 33 by being inserted into this hole and screwed with a screw 33a.

The holder 33 is held by the handpiece 34 by being screwed together with the tip portion 34a of the handpiece 34.

The handpiece 34 is shaped and sized so that it can be grasped by one hand, and the cord 34b.
Is connected to an ultrasonic oscillator (not shown).
As a result, the handpiece 34 can apply ultrasonic vibration to the copper round bar 31 of the polishing tool 30 from the tip portion 34 a of the handpiece 34 via the holder 33.

Next, the operation of this embodiment will be described. FIG.
In order to use the ultrasonic polishing apparatus shown in (1), an ultrasonic oscillator (not shown) is activated to apply ultrasonic vibration from the tip portion 34a of the handpiece 34 to the copper round bar 31 of the polishing tool 30 via the holder 33. Then, the handpiece 34 is moved to lightly press the tip of the round bar 31 against a noble metal made of gold, which is not shown. Then, polishing is performed while moving the tip of the round bar 31 along the surface of the precious metal.

As described above, in the present embodiment, gold is polished with the copper round bar 31 having a hardness lower than that of the gold while ultrasonically vibrating the gold, so that fine portions and concave portions of gold can be easily polished. In addition, it is possible to give a very beautiful luster to the surface of gold without using abrasive grains. In addition, no polishing marks are left on the surface of gold unlike when polishing with a cemented carbide. Furthermore, even if the gold is polished for a long time, the round bar 31 of the polishing tool 30 is not damaged, so that it is not necessary to perform a very troublesome work such as polishing the round bar 31 with a grindstone such as diamond.

Further, since the round end 31 of the copper round bar is curved, it is possible to easily grind fine intricate parts and recesses on the back side of a ring made of precious metal such as gold. Also, since copper is relatively soft, it is easy to bend it.

Next, regarding the sixth embodiment of the present invention,
This will be described with reference to FIG. Here, FIG. 4A is a perspective view of a noble metal polishing tool, and FIG. 4B is a perspective view of an ultrasonic polishing apparatus in which a polishing tool of a modified example of this polishing tool is mounted.

In FIG. 4A, a polishing tool 40 for polishing a noble metal is a flat plate 41 of silver (pure silver) having a width of 2 mm, a thickness of 0.5 mm and a length of 40 mm, and a wall thickness of 0.25 m.
It is composed of a brass flat pipe 42 having a length of m and a length of 23 mm. The flat plate 41 is passed through a pipe 42, and the flat plate 41 is reinforced by being covered with the pipe 42 for about half the length thereof. Furthermore, the flat plate 41 is tightly fixed to the pipe 42 by applying a force to the pipe 42 from the outside. Further, the pipe 42 has a hole 42a formed therethrough.

Flat plate 4 attached to this polishing tool 40
1 has a curved front end like the round bar 31 shown in FIG. As a result, it is possible to easily grind fine intricate parts and recesses on the back side of a precious metal ring or the like. Further, since the flat plate 41 is not pressed to have a partially flat plate shape, it is more robust against ultrasonic vibration than the one shown in FIG. 2B and is less likely to be bent or bent. .

A polishing tool 45 similar to this polishing tool 40
Is attached to a handpiece 44 for ultrasonic processing via a holder 43, as shown in FIG. The polishing tool 45 is a flat silver plate 46 whose tip is obliquely processed.
And a pipe 47 similar to the pipe 42.
The holder 43 is formed with a slit 43b having a width substantially the same as the width of the pipe 47. The polishing tool 45 is held in the holder 43 by being inserted into the slit 43b and screwed with the screw 43a through the hole 42a.

The holder 43 is held by the handpiece 44 by being screwed together with the tip end 44a of the handpiece 44.

The handpiece 44 is the same as that described with reference to FIG. 3, and is connected to an ultrasonic oscillator (not shown) via a cord 44b. As a result, the handpiece 44 can apply ultrasonic vibration to the silver flat plate 46 of the polishing tool 45 from the tip portion 44a of the handpiece 44 through the holder 43.

Next, the operation of this embodiment will be described. FIG.
To use the ultrasonic polishing apparatus shown in (b), an ultrasonic oscillator (not shown) is activated to start the tip portion 4 of the handpiece 44.
4a of the polishing tool 45 through the holder 43 and the silver plate 4
While applying ultrasonic vibration to 6, the handpiece 44 is moved to lightly press the tip of the flat plate 46 against a precious metal made of platinum, which is an object to be polished (not shown). Then, polishing is performed while moving the tip of the flat plate 45 along the surface of the noble metal.

As described above, in the present embodiment, platinum is polished by the flat plate 45 made of silver having a hardness lower than that of the platinum while applying ultrasonic vibration, so that the fine portion and the concave portion of platinum can be easily polished. It is possible to give a very beautiful luster to the surface of platinum without using abrasive grains. In addition, no polishing marks are left on the surface of platinum unlike when polishing with cemented carbide. Furthermore, even if platinum is polished for a long time, polishing tool 4
The flat plate 46 of No. 5 itself is not damaged, so that it is not necessary to carry out a very troublesome work such as polishing the flat plate 46 with a grindstone such as diamond.

Further, in this embodiment, since the flat plate 46 is covered with the pipe 47, the flat plate 46 is reinforced more strongly than when the round bar is simply covered with the pipe. Even if ultrasonic vibration is applied to platinum through the polishing tool 45 for a long time, the flat plate 46 is hardly broken or unnecessarily bent.

In the above embodiment, copper or silver was used as the metal of the polishing portion, but the present invention is not limited to this, and any metal having a hardness lower than that of the noble metal to be polished can be used for polishing. It can be used as a part. Typical metals are copper (pure copper), silver (pure silver), platinum (pure platinum), gold (pure gold), and palladium (pure palladium). These can be used because, as described above, a normal noble metal is alloyed to increase hardness.

[0049]

As described above, according to the present invention,
It is possible to easily grind fine parts and recesses of precious metals such as gold, silver or platinum used as metal for rings and necklaces, and also to polish without leaving a marking on the surface of precious metals. Like

Further, it can be bent relatively softly and used, and it becomes possible to easily grind intricate fine parts and concave portions on the back side of jewelry such as rings made of precious metal.

Further, even if the noble metal is polished for a long time, the tool itself is not damaged, so that it is not necessary to perform a very troublesome work such as polishing with a grindstone such as diamond.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a first embodiment of the present invention.

FIG. 2 is a diagram for explaining second to fourth embodiments of the present invention.

FIG. 3 is a diagram for explaining a fifth embodiment of the present invention.

FIG. 4 is a diagram for explaining a sixth embodiment of the present invention.

FIG. 5 is a view showing a conventional noble metal polishing tool.

[Explanation of symbols]

 10 Polishing Tool 11 Round Bar 12 Pipe 12a Slit 13 Holder 13 Screw 14 Handpiece 14a Tip 14b Code

Claims (8)

[Claims] 1. A method for polishing a noble metal, which comprises polishing a noble metal containing at least one of gold, silver and platinum while applying ultrasonic vibration to a metal having a hardness lower than that of the noble metal. 2. A polishing tool for polishing a noble metal containing at least one of gold, silver and platinum by ultrasonic vibration, which has a polishing portion made of a metal having a hardness lower than that of the noble metal. Polishing tool. 3. The noble metal polishing tool according to claim 2, wherein at least a part of the polishing portion is covered with a metal harder than the polishing portion. 4. The noble metal polishing tool according to claim 2, wherein one end side of the polishing portion is brazed to a metal rod harder than the polishing portion. 5. The noble metal polishing tool according to claim 2, wherein one end side of the polishing portion is formed in a flat plate shape. 6. The noble metal polishing tool according to claim 2, wherein one end side of the polishing portion is curved. 7. The noble metal polishing tool according to any one of claims 2 to 6, wherein the metal having a hardness lower than that of the noble metal is copper. 8. A noble metal polishing tool according to any one of claims 2 to 7, a holder for holding the polishing tool, and a supersonic wave applying ultrasonic vibration to the polishing tool via the holder. An ultrasonic polishing apparatus, comprising: an ultrasonic vibration source.