JPH052604Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a conductor roll for electroplating in which the collector ring portion of the conductor roll in a continuous electroplating apparatus for steel strips is improved.

(Prior art) A continuous electroplating device for steel strips is one in which a large amount of direct current electricity is passed through a fixed positive electrode, and this current is passed through a plating solution to the continuously moving steel strip to be plated,
It is already known that the steel to be plated is continuously electroplated through a conductor roll that rotates at the same circumferential speed, a collector ring that collects the current in the rotating body, and an electric brush that extracts the current from the rotating body to a fixed part. That is what we are doing.

This conductor roll comes into contact with the moving steel strip to be plated, receives electric current for electroplating while rotating at the same circumferential speed as the moving speed of the steel strip, collects the current to the collector ring, and collects the current from multiple It is provided to bring an electric brush (carbon brush) into contact and to flow current to the fixed part.

The conductor roll and collector ring conventionally have a structure as shown in FIG.
That is, a ring-shaped collector ring 5 is fitted onto the shaft 2 of the conductor roll 1, and nuts 6,
It is tightened at 7. The outer circumferential surface of the shaft 2 and the inner circumferential surface of the collector ring 5 are both machined into a tapered shape with the same slope, and are configured to obtain a compressive force by tightening them with a nut 6.

3 in the figure is a water passage.

(Problems to be Solved by the Invention) This collector ring 5 contacts the shaft 2 and the nuts 6 and 7, receives a large current from the steel strip 9 to be plated via the conductor roll body 1 and the shaft 2, and Friction and sparks generated at the contact portion with the plurality of electric brushes 8 cause a temperature rise and thermal expansion. As a result, a gap is generated between the outer circumferential surface of the shaft 2 and the inner circumferential surface of the collector ring 5, resulting in a decrease in the contact area and a decrease in the crimping force, causing contact between the shaft 2 and the collector ring 5 at the crimped portion. A defective phenomenon occurs, the electrical resistance increases, and the collector ring 5
Furthermore, the temperature rises rapidly, causing a large energy loss and often burning out the collector ring or electric brush, making it impossible to conduct plating current and maintaining stable operating conditions. There was a problem with it disappearing.

As a way to solve this problem, a method was developed in which the inside of the collector ring was cooled with water.
This is proposed in Publication No. 47658. Although this method is effective as a measure to prevent burnout of electric brushes and collector rings, water often leaks from the sealing part of the cooling channel, making it impossible to obtain a sufficient cooling effect, or causing water to splash onto the electric brush. However, secondary problems such as abnormal wear occur.

The present invention solves the problem of temperature rise in the collector ring without relying on a water cooling system.

Conventionally, hard copper has been used as the material for collector rings. This is based on the idea that since the collector ring itself becomes a current-carrying body and slides between it and the electric brush, a material with low electrical resistance and good wear resistance should be selected. On the other hand, the shaft of the conductor roll is
Stainless steel is commonly used to increase corrosion resistance against plating solutions.

These problems give rise to the following problems.

The first problem is that since the collector ring is made of copper, it cannot be shrink-fitted when assembled onto the conductor roll shaft. The reason for this is that due to the material properties of hard copper, its hardness decreases rapidly when heated, and even if it is shrink-fitted, the yield point is low, so the inner peripheral surface of the collector ring (shrink-fit surface)
is easily plastically deformed, insufficient shrinkage fit stress is generated, and as a result, the degree of adhesion of the collector ring to the conductor roll shaft is not increased.

The second problem is that the material of the collector ring has a higher coefficient of thermal expansion than the material of the conductor roll shaft. This means that when the plating current is applied, the conductor roll shaft and collector ring generate heat due to electrical resistance, but due to the difference in thermal expansion at this time, a gap is created in the mating area, which reduces the degree of adhesion and generates a large amount of electricity. This means that it becomes a resistance and further promotes heat generation.

Therefore, in order to solve the above-mentioned problems regarding the collector ring and the conductor roll shaft, the present invention was developed by repeatedly devising various ideas, and as a result, it was discovered that the problem can be solved inexpensively and reliably.

(Means for Solving the Problems) The gist of the present invention is that the collector ring incorporated in the shaft end of the conductor roll for continuous electroplating of steel strips is made of steel, and the copper coating surface formed on the inner surface of the collector ring is made of steel. A conductor roll for electroplating, characterized in that it is assembled by shrink fitting through the collector ring, and either or both of the inner circumferential surface in contact with the roll shaft of the collector ring and the outer circumferential surface in contact with the sliding surface of the electric brush. This is a conductor roll for electroplating which has a copper coating surface on the top.

(Example) and (Operation) The details of the present invention will be described below with reference to the drawings.

FIG. 1 is an elevational sectional view of an apparatus according to an embodiment of the present invention.

In the figure, 5 is a collector ring, 2 is a conductor roll shaft, 1 is a conductor roll body, 6, 7
connects the collector ring 5 to the conductor roll shaft 2
4 is the code 1 of each of the above parts,
Bearings supporting the assemblies 2, 5, 6, and 7, and 8 an electric brush.

Further, 3 is a water passage, 9 is a steel strip to be plated, 11 is a copper coating on the inner peripheral surface of the collector ring, and 12 is a copper coating on the outer peripheral surface of the collector ring.

In the embodiment of the present invention, the collector ring 5
General structural rolled steel (SS41) was used as the material. Since the material of the conductor roll shaft 2 is SUS316 in this embodiment, the coefficient of thermal expansion of the collector ring 5 is sufficiently smaller than that of the conductor roll shaft 2 (the coefficient of linear expansion is SUS316; 16.0 10 ^-6 /℃, SS41;
12.2×10 ^-6 /℃) It is possible to prevent the generation of voids in the joint due to the heat generated when the plating current is applied, and at the same time, the degree of tightness of the joint is improved due to the difference in thermal expansion between the conductor roll shaft 2 and the collector ring 5. A more stable energization state can be obtained.

Further, the collector ring 5 is assembled into the conductor roll shaft 2 by shrink fitting. This allows for a much greater degree of adhesion than before in the initial assembled state, and prevents heat generation. In the embodiment of the present invention, the shrink fit was carried out at a shrink fit distance of 0.2 mm and a shrink fit temperature of 150°C to 200°C, and as a result, a sufficient heat generation prevention effect was obtained.
In addition, good performance was obtained over a long period of time without causing plastic deformation on the inner circumferential surface of the collector ring 5.

Furthermore, in this embodiment, the inner and outer peripheral surfaces of the collector ring 5 are plated with copper to a thickness of 0.1.
Coated with mm. The copper coating on the inner circumferential surface is intended to further reduce the electrical resistance of the fitting portion when the collector ring 5 is shrink-fitted to the conductor roll shaft 2.
In other words, the electrical resistance of the fitting part is determined by the degree of adhesion, and in addition to the shrink fit described above, there are ways to increase the degree of adhesion.
By applying a copper coating to the mating surface, the following advantages can be obtained.

Conventionally, in order to ensure good electrical conductivity at the fitting portion, it has been necessary to maintain precise dimensional accuracy at the fitting surfaces, that is, the inner circumferential surface of the collector ring 5 and the outer circumferential surface of the conductor roll shaft 2. In other words, if the circularity, cylindricity, or taper angle of the mating surfaces are not the same, the contact will be non-uniform and the electrical resistance will increase. However, by applying copper coating to the mating surface and shrink-fitting, the copper part is plastically deformed according to the shape of the conductor roll shaft 2, so that a high degree of adhesion can be obtained and electrical resistance can be minimized.

On the other hand, the copper coating on the outer peripheral surface is for improving the smoothness when sliding with the electric brush 8. Usually, electric brushes have carbon as their main component, and the smoothness during sliding, that is, the electrical conductivity, is better on copper than on steel. Copper coating is applied to the outer peripheral surface so as not to impair this characteristic.

(Effects of the invention) The conductor roll of the invention provides the following effects compared to conventional rolls.

(a) Significant power savings can be achieved by reducing the electrical resistance in the collector ring of the conductor roll. Therefore, after the improvement according to the present invention, stable performance with little voltage drop is obtained, and a large power saving effect can be obtained.

(b) By preventing heat generation and burnout problems in the collector ring of the conductor roll, it is possible to avoid production interruptions such as stopping the plating current or stopping equipment for repairs, resulting in stable operations and improved productivity. is obtained.

[Brief explanation of drawings]

FIG. 1 is an elevational cross-sectional view of an apparatus according to an embodiment of the present invention, and FIG. 2 is an elevational cross-sectional view of a conventional apparatus. 1 is a conductor roll body, 2 is a conductor roll shaft, 3 is a water passage, 4 is a bearing, 5 is a collector ring (made of steel), 6 and 7 are nuts, 8 is an electric brush, 9 is a steel strip to be plated, 11 is a Collector ring inner circumferential surface copper coating, 12 collector ring outer circumferential surface copper coating.

Claims (1)

[Claims for Utility Model Registration] (1) A collector ring built into the shaft end of a conductor roll for continuous electroplating of steel strip is made of steel, and the collector ring is made of steel by shrink fitting through a copper coated surface formed on the inner surface of the collector ring. A conductor roll for electroplating, which is characterized by a built-in conductor roll. (2) The electric appliance according to claim 1 of the utility model registration claim, which has a copper coating on either or both of the inner circumferential surface of the collector ring in contact with the roll shaft and the outer circumferential surface in contact with the sliding surface of the electric brush. Conductor roll for Metsuki.