JP2660669B2 - Electrodes for corona discharge generation - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode for generating corona discharge used in an electric dust collector or the like.

[0002]

2. Description of the Related Art Conventionally, a corona discharge is generated in air,
An electrostatic precipitator that charges dust in the air and collects it using electric attraction, an ionizer that ionizes and supplies molecules that make up the air, and an electrophotographic copy that charges or removes the photoconductor and developer by corona discharge A corona discharger is used in such machines.

When a corona discharge is generated by this corona discharger, a non-uniform electric field is formed in the air near the electrodes by applying a high voltage to the electrodes using a needle electrode or a wire electrode. In addition, corona discharge is generated by causing partial breakdown of air by the uneven electric field.

[0004]

In a corona discharge generating electrode for generating a corona discharge as described above,
In order to form a local strong electric field during ventilation around the electrode, it is necessary to make it as thin or sharp as possible, but when corona discharge occurs from the electrode, the electrode is oxidized by ionized air molecules. And corrodes electrically. As a result, in the case of a needle electrode, the point with the sharpest tip that discharges the most efficiently is oxidized fastest, and is covered with an insulating oxide film or the tip is shaved and rounded, resulting in an efficient corona discharge. There were inconveniences such as not being performed well.

In the case of a wire electrode, the tip is not oxidized intensively at one point unlike the needle electrode. However, in the conventional wire electrode, the wire diameter is reduced in order to efficiently generate corona discharge. And this is stretched in the air. For this reason, when the surface of the electrode is oxidized or corroded, it is easily cut, and there is a problem such as lack of durability. In order to prevent such a problem, conventionally, electrodes are manufactured using a conductive ceramic having high mechanical strength and oxidation resistance, titanium, or the like, but a sufficient effect has not been obtained. The present invention has been made in view of such circumstances, and does not decrease the corona discharge efficiency even when used for a long time.
It is an object of the present invention to provide a corona discharge generating electrode having excellent durability.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a cord-like material in which fine short fibers made of a polymer material are twisted and knitted, and the ends of the short fibers protrude innumerably on the surface. In addition, a conductive treatment is performed by means such as baking the string-like material, and a corona discharge is generated by applying a high voltage to the string-like material.

[0007]

According to the above configuration, the ends of the myriad of short fibers protruding from the surface of the corona discharge generating electrode made of a string-like material become the needle-like electrodes and perform corona discharge, so that corona discharge can be performed efficiently.

[0008] Also, by knitting in a string shape, the strength as a string can be given, and the physical strength of the corona electrode can be increased. Furthermore, even if the short fiber terminal is oxidized and corroded, corona discharge is generated from a newly generated terminal, so that corona discharge can be efficiently performed over a long period of time.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to an ionizer will be described in detail with reference to the drawings. 1 is an overall perspective view of the ionizer, FIG. 2 is a cross-sectional view taken along line AA of FIG.
4 is a perspective view of the internal structure, FIG. 4 is a cross-sectional view taken along the line BB of FIG. 3, FIG. 5 is a circuit diagram, FIG. 6 is an enlarged view of a corona discharge generating electrode, and FIG.

In these figures, reference numeral 1 denotes a box-shaped main body whose upper surface is covered by an arc-shaped cover 1a, and a blower fan 3 composed of a cross-flow fan which is driven to rotate by a fan motor 2 is housed inside one end. I have. Above the blower fan 3, an air inlet 4 composed of a number of slits is opened, and the air taken into the main body 1 from the air inlet 4 by the rotation of the blower fan 3 divides the inside of the main body 1. The air is sent to an air outlet 6 opened at the other end of the main body 1 through a passage 5 formed between the dividing wall 1b and the bottom plate 1c, and the air outlet 6 is provided with a louver for adjusting the air discharging direction. 7 are provided.

An electrode 8 for generating corona discharge is stretched in a passage 5 in the main body 1 in a direction orthogonal to a ventilation direction. The corona discharge generating electrode 8 is shown in FIGS.
As shown in, twisting a large number of fine conductive short fibers,
In addition, a string-like material 8 having a diameter of about 3 mm to 5 mm by knitting.
a is formed. As the fine short fibers to be used, a conductive material such as a metal, a carbon fiber having a diameter of 10 μm or less, or the like is used. It is manufactured by carbonizing 8a by high temperature treatment.

On the other hand, the string-shaped corona discharge generating electrode 8 formed as described above is attached via a hook 11 to an insulator 10 fixed at a position facing the body 1 with the passage 5 therebetween. In addition, between one end of the corona discharge generating electrode 8 and one of the hooks 11, there is provided a coil bone 12 made of a conductive material for tensioning the electrode 8. Above and below the corona discharge generating electrode 8, a pair of ground electrodes 13 made of a metal plate are fixed to the lower surface of the partition wall 1b and the upper surface of the bottom plate 1c, respectively. One end of the electrode 8 is connected to the ground side of the high voltage power supply 15 as shown in FIG.
The other end of the corona discharge generating electrode 8 is connected to the (−) side of the high voltage power supply 15 via a high voltage cable 17.

The high-voltage power supply 15 is accommodated in a space 1d formed between the cover 1a and the partition 1b of the main body 1, and is connected to a commercial power supply via the power switch 18 together with the fan motor 2. Has become.

When the power switch 18 is turned on in order to remove dust in the air, the blower fan 3 is rotated by the fan motor 2 and at the same time, the corona discharge generating electrode 8 is A high voltage is applied between the ground electrodes 13. As shown in FIG. 6, the cord-shaped corona discharge generating electrode 8 densely knitted with fine fibers has numerous ends 8b of fine fibers protruding from the surface of the cord 8a, and the surface of these terminals 8b. When receiving the electric charges, they repel each other, and the terminal 8b stands upright at right angles to the axial direction of the string-shaped material 8a.

The end 8b of the upright fiber becomes a thin needle electrode, and a corona discharge is generated between the end 8b and the ground electrode 13 to ionize molecules in the air passing through the passage 5. As a result, the air discharged from the air outlet 6 through the passage 5 becomes ionized air, and the newly generated terminal 8b of the corona discharge generating electrode 8 is oxidized and corroded by corona discharge. 8b, the corona discharge is continued only by changing the location where the corona discharge occurs, so that the discharge efficiency does not decrease.

In addition, during long-term use, most of the terminal 8b is consumed, and the entire cord 8a is oxidized and corroded.
When the discharge efficiency is reduced, ionization can be performed again with high efficiency by replacing the electrode 8 with a new corona discharge generating electrode 8.

In the above embodiment, an ionizer is used. An electric precipitator for generating corona discharge in the air to charge and collect dust contained in the air, and a band elimination for a photoreceptor, a developing material, etc. The present invention can be widely applied to an electrophotographic copying machine.

[0018]

As described in detail above, the present invention forms a cord-like corona discharge generating electrode by twisting and knitting fine short fibers made of a conductive material, and applying a high voltage to this electrode. Since the corona discharge is generated, the terminals of countless short fibers generated on the surface of the cord-like material protrude, and since these terminals become needle-shaped electrodes, even if the terminals are oxidized and corroded by corona discharge, Since corona discharge is generated one after another from newly generated terminals, the discharge efficiency does not decrease.

Further, since the string-like material closely formed by the fine short fibers is formed, the string-like material can be given strength, and the diameter of the string-like material is made larger than that of the conventional needle electrode or wire electrode. In addition, since corona discharge is generated from the ends of fine short fibers, the physical strength of the corona discharge generation electrode can be increased without lowering the discharge efficiency, which makes it more durable than conventional wire electrodes Is significantly improved, and since it can be used until all the terminals of the short fiber have disappeared, it can be used with high efficiency for a long time, and has a much longer life than conventional needle electrodes and wire electrodes.

[Brief description of the drawings]

FIG. 1 is a perspective view of an ionizer using a corona discharge generating electrode according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a perspective view showing an internal structure of an ionizer using a corona discharge generating electrode according to an embodiment of the present invention.

FIG. 4 is a sectional view taken along line BB of FIG. 3;

FIG. 5 is a circuit diagram of an ionizer using a corona discharge generating electrode according to an embodiment of the present invention.

FIG. 6 is an enlarged perspective view of a corona discharge generating electrode according to an embodiment of the present invention.

FIG. 7 is a sectional view of a corona discharge generating electrode according to an embodiment of the present invention.

[Explanation of symbols]

 8 Corona discharge generating electrode 8a String 8b Fiber end

Claims (1)

(57) [Claims] A fine short fiber made of a polymer material is tightly twisted and knitted to form a short fiber end (8) on the surface.
b) strands of material which has countless projecting (8a) formed, Katsuko
Of the string-like material (8a) is made conductive by means such as firing.
With corona discharge generating electrode, characterized in that to generate a corona discharge by applying a high voltage to the string-like material (8a).