JP2000024555A - Method and apparatus for electrostatically applying oil to metal wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To certainly and uniformly apply oil to the peripheral surface of a metal wire by utilizing static electricity by cyclically changing charge applied to oil mist in charging the oil mist at a time of the application of oil to the peripheral surface of the metal wire by guiding the metal wire through the oil mist. SOLUTION: A nozzle 3 spraying oil is arranged in a treatment tank 2 to supply oil mist 4 to a region where a metal wire 1 passes and a discharge wire 6 is further arranged between the path line of the metal wire 1 and the nozzle 3 and the metal wire 1 is passed through the charged oil mist 4 to be coated with the oil. As an electrode body, a structure formed by providing a plurality of discharge wires 6 between the electrodes 5a and 5b provided to the inside wall of the treatment tank 2 under tension is pref. and voltage is supplied across the electrodes 5a and 5b through a constant voltage device and a pulse generator to cyclically change the charge applied to the oil mist 4. That is, voltage is supplied across the electrodes 5a and 5b in a pulse like state and the charge of the oil mist 4 is cyclically changed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for applying oil to a peripheral surface of a metal wire such as a welding wire or various steel wires.

[0002]

2. Description of the Related Art For example, in order to prevent rust and smoothly feed a welding wire to a welding machine, a welding wire is coated with oil between a wire and a finished product before winding. That is what is commonly done. Conventionally, the oil is applied to the peripheral surface of the wire by passing the wire through fibers containing oil. However, in this oiling method, the oil does not uniformly adhere to the peripheral surface of the wire, so when feeding the wire to the welding machine, the frictional resistance increases and hinders the wire supply. Oil adheres locally and slips when feeding the wire to the welding machine,
In addition, there is a problem that diffusible hydrogen in the weld metal increases due to the excess oil, leading to welding defects.

[0003] In order to address this problem, a small amount of a uniform coating film can be obtained on the peripheral surface of the welding wire by using an oiling technique utilizing static electricity, that is, by charging mist oil. A technique of uniformly applying oil to the peripheral surface of a wire has been adopted. However,
The traveling speed of the welding wire after finish drawing is 500-1
Since the speed is as high as 000 m / min, it is difficult to uniformly apply the oil over the entire circumference of the wire simply by passing through the charged oil particles.

[0004] On the other hand, Japanese Patent Publication No. 1-17421 discloses that the flow rate of the transport airflow and the voltage applied to the oil particle charging electrode are controlled in accordance with the traveling speed of the wire.
Proposed.

[0005]

However, even if the oil film obtained by the above-mentioned method was considered to be uniform, there is still a portion where oil particles do not adhere from a microscopic viewpoint. At present, it has not been possible to sufficiently solve the above-mentioned problems due to such unevenness of the oil film. Therefore, an object of the present invention is to more reliably and uniformly apply oil to a metal wire peripheral surface using static electricity.

[0006]

The gist of the present invention is as follows. (1) When a metal wire is guided into an oil mist and oil is applied to the peripheral surface of the metal wire, the oil mist is charged.
A method for electrostatically applying oil to a metal wire, characterized by periodically changing an electric charge applied to an oil mist.

(2) The method of (1) above, wherein the potential difference between the discharge wire for charging the oil mist and the metal wire is periodically changed.

(3) In the above (1) or (2),
An electrostatic oiling method for a metal wire, wherein the metal wire is grounded.

(4) An apparatus for guiding a metal wire into an oil mist sprayed into a processing tank and applying oil to a peripheral surface of the metal wire, wherein an electrode body for charging the oil mist is disposed in the processing tank. The said electrode body has the function to change a voltage periodically, The electrostatic lubrication apparatus of the metal wire characterized by the above-mentioned.

(5) In the above (4), an electrostatic oiling apparatus for a metal wire, wherein a nozzle for spraying oil and a discharge wire for charging the oil mist are arranged in the treatment tank.

(6) The electrostatic lubricating apparatus for metal wires according to (5), wherein a discharge wire is arranged between the nozzle and the metal wire.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 and 2 show a preferred embodiment of an electrostatic oiling apparatus used in the method of the present invention. In the illustrated electrostatic oil coating apparatus, a nozzle 3 for spraying oil is disposed inside a processing tank 2 into which a metal wire 1 is introduced, and an area where at least the metal wire 1 in the processing tank 2 passes from the nozzle 3 The oil mist 4 is supplied to the oil mist 4, and a discharge wire 6 for charging the oil mist 4 is arranged between the pass line of the metal wire 1 and the nozzle 3.
To apply oil. Here, the oil mist is charged in the discharge electrolysis. In addition,
In the electrostatic oiling device, the metal wire 1 may be introduced into the treatment tank 2 filled with the oil mist 4, and the position and the direction of the nozzle 3 and the pass line of the metal wire 1 are not limited to the illustrated example. ,
Various modifications are possible. Further, the oil mist may be introduced from outside the processing tank.

As shown in FIGS. 1 and 2, a plurality of electrode bodies 5 for charging the oil mist 4 are arranged in parallel with each other between electrodes 5a and 5b provided on the inner wall of the processing tank 2. In this example, a structure in which two discharge lines 6a and 6b are stretched in the illustrated example is preferable. These discharge wires 6a and 6b are parallel to the metal wire 1 and are not in contact with each other, and when placed between the nozzle and the metal wire, the mist is charged and the metal wire is efficiently attached. It is preferable because it is carried out in an efficient manner.

A positive or negative voltage is supplied from a power supply 7 to the electrodes 5a and 5b, and the oil mist 4 is charged by discharging from the discharge lines 6a and 6b. At this time, it is important to periodically change the charge applied to the oil mist 4 by supplying a voltage to the electrodes 5a and 5b via the constant voltage device 8 and the pulse generator 9.

For example, a voltage is supplied to the electrodes 5a and 5b in the form of a pulse as shown in FIG. 3 by the action of the constant voltage device 8 and the pulse generator 9, and the charge of the oil mist 4 is changed periodically. is there. It should be noted that the periodic change of the voltage of the electrode body includes the pulse shape shown in FIG.
Although a sine-wave-like voltage pattern shown in FIG. 1 may be used, a pulse shape in which the charged state of oil particles is clear and good adhesion can be expected is more preferable. By this operation, the oil mist 4 becomes a collection of oil particles having different electric charges, so that the oil particles are efficiently attached to the peripheral surface of the metal wire 1 and uniform oiling is realized. This point will be described later in detail.

Further, in periodically changing the electric charge applied to the oil mist 4, the potential difference between the discharge wire 6 and the metal wire 1 is periodically changed, wherein the potential of the metal wire 1 is set near the ground. In particular, it is advantageous to ground the metal wire 1 and to apply the voltage intermittently to the discharge wire 6 because the equipment is simple.

That is, when a negative constant voltage is intermittently applied to the discharge line 6 and a voltage pattern in which zero voltage and -A appear alternately as shown in FIG. The particles will be given a zero charge and a negative charge.

Here, a mechanism for uniformly forming the adhesion of the oil particles on the surface of the metal wire 1 in the present invention will be schematically described in comparison with that of the conventional method. FIG. 6 is a schematic diagram of a conventional method in which a metal wire is grounded and a negative charge is always constantly applied to an oil mist. In the conventional method, first, when the negative oil particles reach the surface of the metal wire, as shown in FIG. 3A, the negative oil particles immediately lose their charge due to the grounded metal wire and adhere as particles having zero charge. Next, when the minus oil particles further reach the oil particles attached to the surface of the metal wire, the oil particles reaching the zero-charged oil particles as shown in FIGS. Deposition is performed without losing charge while maintaining a negative charge state. When the minus oil particles further approach the metal wire in such a surface state, the minus oil particles repel each other, as shown in FIG. 9E, and the oil particles reach the bare metal wire surface. It acts as an inhibitor and does not provide a bond between oil particles,
The oil film does not grow uniformly.

On the other hand, according to the present invention, FIG.
When the oil mist 4 is charged according to the voltage pattern shown in (1), non-charged oil particles are present in addition to the negative oil particles.
For this reason, as shown in the schematic diagram of FIG. 7, the repulsion between the minus oil particles is eliminated, and the uncharged oil particles are securely attached to the minus oil particles, and furthermore, the uncharged oil particles are Because minus oil particles will adhere,
Oil particles accumulate one after another and the oil film grows uniformly. As described above, by changing the charge of the oil mist, the charge of the oil mist adhering to the metal wire also changes, the repulsion between the oil mist is weakened, the adhesion is improved, and uniform adhesion becomes possible. In FIG. 5, when positive voltage is intermittently applied instead of negative voltage, and when positive and negative voltages are alternately applied, positive oil particles, uncharged oil particles, and negative oil It is a matter of course that the same effect can be expected as a combination of particles and plus oil particles.

In the present invention, when charging the oil mist 4 with the voltage pattern shown in FIG. 5, it is advantageous that the voltage applied to the discharge line is in the range of more than 0 and 20 kV or less. Of course, the voltage to be added may be either negative or positive, and the upper limit may be 20 kV. Because
FIG. 8 shows the relationship between the voltage and the amount of oil applied to the metal wire. As shown in FIG. 8, when the applied voltage exceeds 20 kV, the charged oil particles repel each other and the amount of oil applied tends to decrease. This is because the amount of oil applied to the wire cannot be controlled.

In the voltage pattern shown in FIG. 5, the ratio x / X of the voltage application time is 0.3 to 0.5.
It is preferable to set it in the range of 7. Because Figure 9
X / X is 0.3 to 0.3 as shown in FIG.
This is because the oil particle occupied area ratio increases in the range of 7. This is presumably because if the ratio of the uncharged particles to the charged particles is not within an appropriate range, the oil particles aggregate before adhering to the metal wire.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS 700 m / mi using the apparatus shown in FIG.
The oil mist was charged under the conditions shown in Table 1 in accordance with the voltage pattern shown in FIG. 5 in applying oil to the peripheral surface of the welding wire having a diameter of 1.2 mm supplied by n. Further, as one of the comparative examples, an oil coating in which the oil mist was continuously charged at a constant voltage was performed. With respect to the welding wire obtained in this way after the oiling treatment, the feedability of the conduit cable, that is, when the wire having a radius of 30 cm is fed in three rounds in a 10 m long conduit cable, the inside of the conduit cable And the number of clogging at the welding tip was evaluated. Table 1 shows the results.
It is described together. From Table 1, it can be seen that in the example of the invention, clogging of the welding wire in the conduit cable is drastically reduced, and extremely good feedability is obtained. These effects are:
This is because uniform and proper oiling was performed on the metal wire.

[0023]

[Table 1]

[0024]

According to the present invention, it is possible to reliably and uniformly apply oil to a metal wire using static electricity, and particularly to cover the metal wire with a dense oil film even in a microscopic view.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an apparatus of the present invention.

FIG. 2 is a diagram showing an electrode and a power supply system.

FIG. 3 is a diagram showing a voltage pattern applied to a discharge line.

FIG. 4 is a diagram showing a voltage pattern applied to a discharge line.

FIG. 5 is a diagram showing a voltage pattern applied to a discharge line.

FIG. 6 is a schematic diagram showing an attachment mechanism of oil particles.

FIG. 7 is a schematic view showing an attachment mechanism of oil particles according to the present invention.

FIG. 8 is a diagram showing the relationship between the amount of applied oil and the voltage.

FIG. 9 is a diagram showing a relationship between an oil particle occupied area ratio and a voltage application cycle.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal wire 2 Processing tank 3 Nozzle 4 Oil mist 5 Electrode body 5a, 5b Electrode 6a, 6b Discharge wire 7 Power supply 8 Constant voltage device 9 Pulse wave generator

Claims (6)

[Claims] When a metal wire is guided into an oil mist and oil is applied to a peripheral surface of the metal wire, an electric charge applied to the oil mist is periodically changed when the oil mist is charged. An electrostatic oiling method for metal wires. 2. The method according to claim 1, wherein a potential difference between a discharge wire for charging the oil mist and the metal wire is periodically changed. 3. The method according to claim 1, wherein the metal wire is grounded. 4. An apparatus for guiding a metal wire into an oil mist sprayed into a processing tank and applying oil to a peripheral surface of the metal wire, wherein an electrode body for charging the oil mist is disposed in the processing tank. The electrode body has a function of periodically changing a voltage. 5. The electrostatic oiling device for metal wires according to claim 4, wherein a nozzle for spraying oil and a discharge wire for charging the oil mist are arranged in the processing tank. 6. An apparatus according to claim 5, wherein a discharge wire is arranged between the nozzle and the metal wire.