JPH093569A - Gold alloy for sliding contact - Google Patents

Abstract

PURPOSE: To reduce the transfer of wear particle and to bring a slip ring and a brush into smooth contact with each other by incorporating specific amounts of Be and Ru into an Au-Ag-Ni type gold alloy for sliding contact. CONSTITUTION: The gold alloy for sliding contact has a composition consisting of, by weight, 20-60% Ag, 2-7% Ni, 0.1-1%, in total, of either or both of Be and Ru, and the balance Au with inevitable impurities. By using this gold alloy, the occurrence of transfer of the wear particle forming at the time of sliding between a slip ring and a brush to the brush as a mating material can be reduced. In this alloy, the preferred ranges of Ag content and Ni content are 20-40% and 3-5%, respectively, and the preferred range of the content of Be and/or Ru is 0.1-0.5%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gold alloy used for a sliding contact such as a commutator of a small precision motor, and in particular, it shows excellent characteristics when used as a slip ring material for a VTR head. The present invention relates to a gold alloy for moving contacts.

[0002]

2. Description of the Related Art Conventionally, a slip ring of a VTR head has a sliding contact material such as Au-Ag alloy (for example, A
u-10% by weight Ag alloy).
-Slip ring made of Ag alloy sliding contact material is A
It rotates at high speed in a state of being in contact with a brush made of a u-Ag-Pd alloy. However, VTRs for home use
The rotational speed of the slip ring of the VTR for business use is at most 2000 rpm, while the rotational speed of the slip ring of the commercial VTR is 5 rpm.
Since high-speed rotation of 000 to 10,000 rpm is required, the Au-Ag alloy has a drawback that it has low hardness and is easily worn. Therefore, Ni is added to the Au-Ag alloy to increase the hardness and improve the wear resistance of Ag: 30 to 60% by weight and Ni: 4 to 10% by weight, and the balance is Au and inevitable impurities. A of composition
A gold alloy for a u-Ag-Ni-based sliding contact has been provided (see JP-A-6-73470).

[0003]

However, in recent years, the performance of general household VTRs and commercial VTRs has been improved, and the rotational speeds of slip rings used in these VTRs are required to be higher and higher. It's coming. For such high-speed rotation of the slip ring, the conventional Au-Ag-N
The i-system sliding contact gold alloy can withstand the slip ring rotation speed of about 10000 rpm, but when the slip ring rotation speed becomes 15000 rpm or more, wear powder generated during sliding between the slip ring and the brush is generated. However, there was a problem that the smooth ring was gradually transferred to the brush, and gradually accumulated, which hindered smooth contact between the slip ring and the brush.

[0004]

Means for Solving the Problems Accordingly, the present inventors have:
From this point of view, as a result of research to obtain a gold alloy for sliding contacts, which is more excellent as a slip ring, the result of the conventional Au alloy
The gold alloy for sliding contacts obtained by adding 0.1 to 1% by weight of one or two of Be and Ru to a gold alloy for sliding contacts of Ag-Ni system is a conventional Au alloy. -Ag-Ni
1500 less than the gold alloy for sliding contacts
The inventors have found that even when the slip ring is rotated at a high speed of 0 rpm or more, there is little transfer and the smooth contact between the slip ring and the brush is not hindered.

The present invention has been made on the basis of such knowledge, and is weight% (hereinafter,% means weight%).
Then, (1) Ag: 20 to 60%, Ni: 2 to 7%, B
e: a gold alloy for sliding contacts, containing 0.1 to 1% and the balance being Au and inevitable impurities, (2)
Ag: 20-60%, Ni: 2-7%, Ru: 0.1
Gold alloy for sliding contacts, containing 1% and the rest being Au and inevitable impurities, (3) Ag: 20-
60%, Ni: 2 to 7%, Be and Ru totaling 0.
A gold alloy for sliding contacts, containing 1 to 1% and the balance being Au and inevitable impurities, (4) From the gold alloy for sliding contacts according to (1), (2) or (3) above It is characterized by the slip ring.

In the gold alloy for sliding contacts according to the present invention, A
It is not preferable to set the g content to 20 to 60% because if the Ag content is less than 20%, the Au content increases and the welding resistance decreases. On the other hand, if the Ag content exceeds 60%, the corrosion resistance increases. This is not preferable because it lowers the noise and causes noise. A more preferable composition range of the Ag content of the gold alloy for sliding contacts of the present invention is 20
４０40%. Further, the Ni content is set to 2 to 7% because when Ni is less than 2%, the wear resistance and the corrosion resistance are not improved, while when Ni is contained in excess of 7%, the ductility decreases and the casting This is because it is not preferable because the workability and workability are deteriorated. The more preferable composition range of the Ni content of the gold alloy for sliding contacts of the present invention is 3
~ 5%. Furthermore, one or two of Be and Ru contained in the gold alloy for sliding contacts according to the present invention may be used in an amount of 0.1 to 0.1%.
The reason for limiting the content to 1% is that if the content of these components is less than 0.1%, the transition inhibition is not sufficiently performed, while if the content exceeds 1%, oxides are easily formed on the surface and the contact resistance value increases. In addition, it is not preferable because the workability is significantly deteriorated. A more preferable composition range of one or two of Be and Ru contained in the gold alloy for sliding contacts of the present invention is 0.1 to 0.5%.

[0007]

EXAMPLES Gold alloys for sliding contacts of the present invention (hereinafter referred to as the gold alloys of the present invention) 1 to 15 having the component compositions shown in Tables 1 and 2 in a normal vacuum melting furnace, and gold alloys for comparative sliding contacts. (Hereinafter, referred to as comparative gold alloy) 1 to 4 and conventional sliding contact gold alloy (hereinafter referred to as conventional gold alloy) 1 are melted,
Each is cast into an ingot having dimensions of 5 mm in length, 5 mm in width, and 100 mm in length, and the obtained ingot is cold-rolled under normal conditions and slitted to give a thickness of 0.8 mm and a width: After making a plate material of 30.5 mm into a cylindrical shape by bending this plate material, both ends are welded to produce a pipe, and this pipe is expanded to a predetermined size,
Used as a material for slip rings. Next, this material was cut and processed into a ring, the obtained ring was incorporated into a VTR head as a slip ring, and each of the slip rings was brought into contact with a brush.

The slip ring thus mounted on the VTR head plays a role of detecting an electric signal generated from the VTR head rotating about its axis. The material of the brush is Au-Ag-, which is commonly used.
A Pd-based alloy was used. The present invention gold alloy 1 ~
15, a VTR head equipped with a slip ring made of comparative gold alloys 1 to 4 and conventional gold alloy 1 was used at a temperature of 40.
Rotation speed: 15000 rp under conditions of ° C and humidity: 60%
m, no-load current value at the start of operation: rotate at 30 mA,
The time required for the gold alloy of the slip ring to transfer to the brush surface over 3 mm ² (corresponding to the area of a circle with a diameter of 2 mm) was measured, and the no-load current value after 3000 hours of operation was measured. The results are shown in Tables 1 and 2.

[0009]

[Table 1]

[0010]

[Table 2]

[0011]

From the results shown in Tables 1 and 2, B
Conventional gold alloy 1 containing no e and Ru and comparative gold alloys 1-2 containing small amounts of Be and Ru which are outside the scope of the present invention
Since the slip ring consisting of 3 mm ² has a short transition time, the transfer to the brush surface is remarkable and 3000 mm ^2.
Although the contact resistance increases due to the transition due to the large no-load current value after the time of rotation, the slip rings made of the gold alloys 1 to 15 of the present invention do not undergo the transition from the slip ring even after being rotated for 3000 hours. Further, it can be seen that the contact resistance hardly increases because the no-load current value hardly changes. On the other hand, the slip rings made of the comparative gold alloys 3 to 4 containing a larger amount of Be and Ru than those of the present invention have no transition to the brush surface,
It can be seen that the no-load current value is large because the resistance value of itself is large.

As described above, the gold alloy for sliding contacts according to the present invention can reduce the transfer of the slip ring rotating at high speed to the brush surface, and has an excellent effect on the development of the electric industry such as VTR. It is a thing.

Claims (4)

[Claims] 1. Ag: 20-60%, Ni:
2 to 7%, Be: 0.1 to 1%, and the balance being Au and inevitable impurities. 2. By weight%, Ag: 20-60%, Ni:
2 to 7%, Ru: 0.1 to 1%, and the rest of the composition is Au and inevitable impurities. 3. Ag: 20-60%, Ni:
A gold alloy for sliding contacts, which has a composition of 2 to 7%, 0.1 to 1% of Be and Ru in total, and the balance of Au and inevitable impurities. 4. A slip ring for a VTR head, which is made of the gold alloy for sliding contacts according to claim 1, 2, or 3.