JP2001058280A - Clad material for coin and clad coin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coin having an excellent discrimination characteristics and a raw material therefor. SOLUTION: The clad material 1 for a coin is composed of a lamination of plural layers and made by a pressurized contact of adjacent layers. A first surface layer 2 of the one surface side is formed with Cu-Zn alloy consisting of >=45 wt.% Zn and the balance essentially of pure Cu or with Cu, and a second surface layer 3 of the other surface side is formed with a non-magnetic metal having a silvery white color. The surface hardness of the first surface layer 2 and the second surface layer 3 is Hv 50 to 250. The clad coin is the one in which a rugged pattern is carved on the surface of a raw material of the coin made by blanking the clad material 1 into the form of a coin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clad coin used for amusement machines or as money, and a clad material as a material thereof.

[0002]

2. Description of the Related Art Coins used in amusement machines include brass,
It is formed of a relatively inexpensive non-magnetic metal material such as a Cu alloy such as nickel silver, aluminum and its alloys, and stainless steel. On the other hand, coins used as money
Most of them are made of one kind of material, but the surface layer and the back layer are made of an expensive material such as silver, and an intermediate layer made of a relatively inexpensive material such as copper is provided between them, and they are pressed against each other. Used clad coins may be used.

[0003] Both coins for amusement machines and coins for money, including clad coins, are formed of the same color metal on the front and back surfaces, and thus have poor discrimination. Particularly, in coins for amusement machines, the coins also identify a game provider and represent a game to be provided, so that excellent discrimination is an important factor as a coin for amusement machines.

The present invention has been made in view of such a problem, and an object of the present invention is to provide a coin having excellent discriminability and a material thereof.

[0005]

A clad material for coins according to the present invention is a clad material for coins in which a plurality of layers are laminated and adjacent layers are pressed against each other, and a first surface layer on one surface side. Is formed of a CuZn alloy or pure Cu having Zn of 45 wt% or less, with the balance being Cu as a main component, and the second surface layer on the other surface side is formed of a silver-white nonmagnetic metal,
The surface hardness of the first surface layer and the second surface layer is Hv50 to 250.
It is said that.

According to this coin cladding material, the first surface layer has a golden or copper color, and the second surface layer has a silvery white color. Further, since the CuZn alloy forming the first surface layer is inexpensive and non-magnetic, the material as a whole is inexpensive, non-magnetic, and is not magnetized. Therefore, when processed into coins, there is no possibility that the electronic machine or the like malfunctions due to the magnetized coins. The surface hardness of the first surface layer and the second surface layer is Hv5.
Since it is 0 to 250, it has a strength that can be used as a coin, and is excellent in punching and engraving. In the present invention, the term “non-magnetic” means a case where an electronic machine or the like using a coin has no adverse effect such as a malfunction and has a magnetic permeability of 1.5 or less.

As the non-magnetic metal material, a non-magnetic stainless steel is preferable because of its relatively low cost and excellent strength, and preferably Cr: 14 to 20 wt%, Ni: 7 to 15 wt%,
Austenitic stainless steel containing the balance Fe as a main component, more preferably 14 to 18 wt% of Cr and 13 of Ni
Austenitic stainless steel containing 15 wt% and the balance Fe as a main component is preferred. Further, the first surface layer and the second
An intermediate layer may be provided between the outer layer and the surface layer, and the intermediate layer may be formed of a non-magnetic metal. In this case, the intermediate layer is preferably formed of the non-magnetic stainless steel from the viewpoint of cost reduction and strength improvement. When the intermediate layer is formed of non-magnetic stainless steel, the second surface layer is preferably formed of a Cu alloy containing Cu and Ni as main components.

[0008] The clad coin of the present invention is formed by stamping an uneven pattern on the surface of a coin material punched from the coin clad material. According to this coin, one surface is copper-colored or golden, and the other surface is silver-white, so that the discrimination is excellent. In addition, since it is nonmagnetic as a whole, malfunction of the electronic machine does not occur. Also,
When the second surface layer or the intermediate layer is formed of non-magnetic stainless steel, the strength is increased and the durability is excellent.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments with reference to the drawings. FIG. 1 is a cross-sectional view of a two-layer clad material for coins according to a first embodiment of the present invention. In this clad material 1, an upper first surface layer 2 and a lower second surface layer 3 are pressed against each other. , Diffusion bonded. In the illustrated example, the first surface layer 2 is arranged above the second surface layer 3, but there is no technical meaning above and below the arrangement.

The first surface layer 2 is made of a relatively inexpensive material, such as 45 wt% or less of Zn, and
It is made of a Zn alloy (brass) or pure Cu, and has a golden or copper color. The CuZn alloy has a microstructure composed of an α-phase single phase or two phases of an α-phase and a β′-phase with good workability, and the Zn content is preferably 43 wt% or less. In order to give a golden color, Zn should be contained at about 10 wt% or more, preferably 30 wt% or more.

The second surface layer 3 is made of a non-magnetic metal material having a silvery white color. As such a metal material,
Al alloys and Ti alloys can be used, but Cu,
Cu alloy containing Ni as a main component, that is, Ni: 10 to 6
0 wt% (preferably Ni: about 10 to 30 wt%), balance C
CuNi alloy (white copper) containing u as a main component, Ni: 10 to 10
33 wt% (preferably about 10 to 20 wt%), Zn: 13
~ 35wt% (preferably about 15 ~ 30wt%), balance Cu
Is preferred.
These Cu alloys are easily available, have excellent pressure contact with the first surface layer 2 formed of a CuZn alloy, and have excellent corrosion resistance.

It is also preferable to use non-magnetic stainless steel as the non-magnetic metal material. Non-magnetic stainless steel
It is an inexpensive material compared to the white copper and nickel silver, and has excellent corrosion resistance and high strength. By using non-magnetic stainless steel,
The strength and durability of the clad coin can be improved, and the coin is less likely to be deformed even if it is severely used, and jamming due to deformation of the coin at the coin slot and discharge port of the electronic machine that uses the coin. Can be prevented.

As the non-magnetic stainless steel, Cr: 14
Austenitic stainless steel containing -20 wt%, Ni: 7-15 wt%, and the balance Fe as a main component is non-magnetic,
It is preferable because it is relatively easily available. In particular, Cr: 14
Austenitic stainless steel containing 18 wt%, Ni: 13-15 wt%, and the balance of Fe as the main component is not only non-magnetic, but also has a relatively low hardness and a small difference in hardness with the first surface layer 2 so that it is punched. It is suitable because it has excellent workability and excellent engraving.

The surface hardness of the first surface layer 2 and the second surface layer 3 is Hv50-250. If it is less than Hv50, the abrasion resistance is poor and the strength is low, so that it is easily deformed. On the other hand, when Hv250 is exceeded, the stamp becomes unclear, and when stamping out the coin material from the clad plate by pressing, the press mold is excessively loaded and the mold is easily worn, so the mold exchange becomes frequent. Productivity decreases. Preferably Hv 80 to 220, more preferably Hv
It is good to be 80-180. First surface layer 2 and second surface layer 3
By reducing the difference in hardness, the punchability can be further improved.

The thickness of the first surface layer 2 and the second surface layer 3 is appropriately determined according to the required coin thickness. Normal,
Although the first surface layer 2 and the second surface layer 3 are formed to have the same thickness,
For example, a layer with low material cost may be made thicker, and the other may be made thinner.

The clad material 1 for coins is punched into an appropriate size by a press to form a coin material, and a concave and convex pattern is imprinted on the surface thereof, thereby forming a clad coin. The peak-to-valley difference from the upper end of the convex to the lower end of the concave of the uneven pattern is usually
It is about 0.01 to 0.1 mm. The influence of the stamp is limited to the stamped irregularities and hardly reaches the inside of the first surface layer 2 and the second surface layer 3. After engraving,
If necessary, the clad coin may be subjected to barrel polishing or the like.

Here, a method of manufacturing the clad material for coins will be briefly described. First, a brass thin plate formed of a CuZn alloy as a material of the first surface layer 2 and a second brass plate
A silver-white thin plate made of a silver-white nonmagnetic metal as a material of the surface layer 3 is prepared, and the thin plates are overlapped and pressed.

As the pressing method, a roll pressing method in which the stacked thin plates are passed through a gap between a pair of pressing rolls and pressed down is preferable because of excellent productivity. In addition, pressure welding may be performed by warm pressure welding performed at a temperature higher than room temperature, hot pressure welding,
Cold welding performed at room temperature is excellent in productivity. The rolling reduction (initial rolling reduction) at the time of cold pressure welding may be usually about 50 to 65%, and then may be reduced at an appropriate rolling reduction as needed to obtain a predetermined thickness.

After the pressure welding, diffusion annealing is performed to improve the bonding between the first and second surface layers. The annealing temperature is lower than the lower melting point mp of the melting points of the materials forming the first and second surface layers, preferably (mp-100) ° C to (mp-250).
℃, usually about 700-800 ℃, 1-2
It may be heated for about a minute or more. The upper limit of the heating time is not particularly defined, but from the viewpoint of productivity, about several tens minutes or less is sufficient. Note that when annealing at a high temperature of about 500 ° C. or more, it is preferable to perform annealing in an inert gas atmosphere such as nitrogen gas in order to prevent oxidation.

After the diffusion annealing, if necessary, a finishing reduction of about 10% or less, preferably 5% or less may be performed for the purpose of adjusting the outer shape and adjusting the hardness. The clad material manufactured as described above is slit into an appropriate width as necessary, and punched into an outer shape of a coin to obtain a coin material.

FIG. 2 shows a second embodiment of the present invention.
The sectional view of clad material 21 for layer coins is shown. The clad material 21 for coins according to the present embodiment has an intermediate layer 24 provided between an upper first surface layer 22 and a lower second surface layer 23, and adjacent layers are pressed and diffusion bonded. is there. Also in this embodiment, there is no point in distinguishing the first surface layer 22 and the second surface layer 23 from top and bottom.

The first surface layer 22 and the second surface layer 2 of this embodiment
3 is basically the first surface layer 2 and the second surface layer 3 of the first embodiment.
It can be formed of the same as described above. The intermediate layer 24
Is provided in order to reduce the material cost or further improve the strength, as a material, the material cost is low, non-magnetic metal having corrosion resistance, for example, pure Cu,
CuZn alloy and non-magnetic stainless steel are preferred. As a non-magnetic stainless steel, relatively easily available and low-cost C
An austenitic stainless steel containing r: 14 to 20 wt%, Ni: 7 to 15 wt%, and the balance being Fe is preferable. Although the engraving property is not required for the intermediate layer 24, the first
If the difference in hardness between the surface layer 22 and the second surface layer 23 increases, the punching property decreases, so that Cr: 14 to 18 wt%, N
i: Austenitic stainless steel containing 13 to 15 wt% and the balance Fe as a main component is preferable. The intermediate layer 24
Is intended to reduce the material cost, it is preferable that the thickness is larger than the first surface layer 22 and the second surface layer 23.

When the intermediate layer 24 is formed of non-magnetic stainless steel, the material of the second surface layer 23 is CuNi having Cu and Ni as main components, which has good press contact with non-magnetic stainless steel and good engraving. It is preferable to use an alloy or a CuNiZn alloy.

The clad material 21 for coins is formed by laminating thin plates as the material of each layer and pressing them together.
It is manufactured by performing diffusion annealing at 800 ° C. and applying a finishing reduction of 10% or less, preferably 5% or less as necessary. The annealing time is about several minutes to several tens as described above.
Minutes.

Hereinafter, the present invention will be further described with reference to examples, but the present invention is not limited to the above embodiments and the following examples.

[0026]

EXAMPLE A first surface layer thin plate (2 mm thick) made of brass and a second surface thin plate (2 mm thick) made of a silver-white non-magnetic metal material as shown in Table 1 below were prepared. , And passed through the gap between the pair of reduction rolls to reduce the initial reduction rate to 6
The pressure was set to 0% and cold pressing was performed at the second rolling reduction shown in the same table, and both thin plates were pressed to obtain a laminate having a two-layer structure in which the first surface layer was pressed against the second surface layer.

Further, a thin plate for the first surface layer (plate thickness 1 mm) made of brass described in the same table, a thin plate for the intermediate layer (plate thickness 2 mm) made of pure Cu or nonmagnetic stainless steel, a silver-white nonmagnetic metal Prepare a second surface layer thin plate (1 mm thick) made of a material, superimpose these thin plates, and reduce the initial rolling reduction to 60%.
Further, cold roll pressing was performed at the second rolling reduction shown in the same table to obtain a laminate having a three-layer structure in which the first surface layer was pressed against the second surface layer via the intermediate layer.

[0028]

[Table 1]

These laminates were subjected to diffusion annealing at the annealing temperatures shown in Table 2 with an annealing time of 3 minutes. Thereafter, a finish reduction was performed at a reduction ratio shown in the same table to obtain a clad material having a thickness of 1.24 mm. Tensile test pieces and magnetic permeability measurement pieces were collected from this clad material. Also, a coin material having a diameter of 25 mm was punched out of the clad material by a press. At the time of punching, the first surface layer (brass layer) was used as the die side. After punching, the surface hardness of the obtained coin material was measured. In addition, the concavo-convex pattern was stamped on both surfaces of the coin material using a stamping die having a concentric concavo-convex pattern formed thereon. The hardness at the center of each layer after the marking was measured and found to be almost equal to the surface hardness of the coin material.

The results of these investigations are also shown in Table 2. In Table 2, the magnetic properties are as follows.
A sample having a magnetic permeability of more than 1.2 and 1.5 or less was evaluated as ○, and a sample having a magnetic permeability of more than 1.5 was evaluated as ×. In addition, the engraving property of the first surface layer (brass layer) was good for all samples, and Table 2 shows the engraving property of the second surface layer. When the edge of the engraved unevenness did not collapse, the unevenness pattern was clear and marked ◎, when the unevenness slightly collapsed was evaluated as ○, and when the unevenness was severe and the unevenness pattern was unclear, × did. Although the punching properties were generally good, it was presumed that Sample Nos. 7 and 8 had a higher pressing force than the other samples, and that the mold was greatly worn during mass production.

[0031]

[Table 2]

As shown in Tables 1 and 2, Samples Nos. 1 to 6 and Nos. 11 to 16 satisfying the hardness conditions of the present invention were all non-magnetic and had good engraving properties. In addition, Nos. 1-4, 7- using nonmagnetic stainless steel for the second surface layer or the intermediate layer.
10, 13, and 14 were also confirmed to have high strength and excellent durability.

[0033]

According to the present invention, the first surface layer has a copper color or a golden color, and the second surface layer has a silvery white color. Further, since the CuZn alloy forming the first surface layer is inexpensive and non-magnetic, the material as a whole is inexpensive, non-magnetic, and is not magnetized. Therefore, when processed into coins, there is no possibility that the electronic machine or the like malfunctions due to the magnetized coins. In addition, since the surface hardness of each surface layer is set to Hv50 to 250, it has a strength that can be used as a coin,
Excellent engraving.

[Brief description of the drawings]

FIG. 1 is a sectional view of a clad material for coins according to an embodiment.

FIG. 2 is a cross-sectional view of a clad material for coins according to another embodiment.

[Explanation of symbols]

 1,21 Clad material for coins 2,22 First surface layer 3,23 Second surface layer 24 Intermediate layer

Continued on the front page (72) Inventor Hiroki Matsuda 2-19-1, Minami Suita, Suita-shi, Osaka Sumitomo Special Metals Co., Ltd. F-term (reference) 4A067 AA03 AA07 BB01 BD02 EB00 EB11

Claims (9)

[Claims] 1. A coin clad material in which a plurality of layers are laminated and adjacent layers are pressed against each other, wherein the first surface layer on one surface side is Zn 45 wt% or less, and the balance Cu
The second surface layer on the other surface side is formed of a non-magnetic metal exhibiting silver white, and the surface hardness of the first surface layer and the second surface layer is Hv50 to 250. Clad material for coins. 2. The cladding material for coins according to claim 1, wherein the second surface layer is formed of non-magnetic stainless steel. 3. The non-magnetic stainless steel is Cr: 14 to 2
The clad material for coins according to claim 2, wherein the clad material is an austenitic stainless steel containing 0 wt%, Ni: 7 to 15 wt%, and the balance being Fe. 4. The non-magnetic stainless steel is Cr: 14-1.
The clad material for coins according to claim 3, wherein the clad material is an austenitic stainless steel containing 8 wt%, Ni: 13 to 15 wt%, and the balance Fe as a main component. 5. A coin cladding material wherein an intermediate layer is provided between a first surface layer on one surface side and a second surface layer on the other surface side, and adjacent layers are pressed against each other. One surface layer is formed of a CuZn alloy or a pure Cu containing 45 wt% or less of Zn and a balance of Cu as a main component.
The surface layer is formed of a silver-white nonmagnetic metal,
The surface hardness of the surface layer and the second surface layer is Hv50 to 250.
Wherein the intermediate layer is formed of a non-magnetic metal. 6. The clad material for coins according to claim 5, wherein the intermediate layer is formed of non-magnetic stainless steel. 7. The clad material for coins according to claim 6, wherein the nonmagnetic stainless steel is the austenitic stainless steel according to claim 3 or 4. 8. A method according to claim 1, wherein the second surface layer is composed mainly of Cu and Ni.
8. The cladding material for coins according to claim 6, wherein the cladding material is made of a u alloy. 9. A clad coin having a concave-convex pattern imprinted on the surface of a coin material punched from the clad material for coins according to claim 1. Description: