JPH11297455A - Discharge electrode needle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain dusting of metallic particles due to abrasion and to continue a stable discharge chracteristic for a long time by arranging a male screw in the base end part of a needle main body manufactured with zirconium oxide, having a specific resistance in a specific range, and threadedly engaging the male screw with a female screw of a stainless steel short tube-like needle holder. SOLUTION: A male screw 2 is arranged in the base end part of a needle main body 1 manufactured by zirconium oxide, having a specific resistance value of 5 to 20 MΩ/cm, and a female screw 4 is arranged in the half part of the inner peripheral surface of a needle holder 3 composed of a stainless short tube. The male screw 2 of the needle main body 1 is threadedly engaged with this female screw 4, and a discharge electrode needle having the needle main body 1 detachably and replaceably held in the needle holder 3 is arranged in the center in a nozzle being a grounding side electrode. High frequency output of an oscillating circuit is converted into high voltage by a high frequency transformer to be impressed on the needle holder 3, and ions generated by discharge is blown upon an object to be charge neutralized together with air. This zirconium oxide can prevent an electric shock by the needle itself, and is hardly damaged at handling time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge electrode needle used for a static eliminator or the like.

[0002]

2. Description of the Related Art The material of conventional discharge electrode needles is mostly stainless steel or tungsten, and these metals are liable to be abraded by electric discharge, so that they generate dust. Adhered to devices etc., causing trouble.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to reduce the generation of metal particles due to abrasion due to the use of a metal material having high abrasion resistance, to maintain a stable discharge characteristic for a long time, and to reduce electric shock. It is to provide a discharge electrode needle.

[0004]

According to the present invention, there is provided a discharge electrode needle comprising:
The needle body is made of zirconium oxide having a specific resistance of 5 MΩ / cm to 20 MΩ / cm.

Zirconium oxide is a metal having high abrasion resistance and has a relatively high specific resistance itself. Therefore, zirconium oxide has a small amount of abrasion due to discharge and suppresses abnormal discharge such as spark discharge, and is stable. Discharge characteristics can be maintained.
If the specific resistance of zirconium oxide is less than 5 MΩ / cm, electric shock is likely to occur, and if it exceeds 20 MΩ / cm, the discharge current is reduced and the ion generation performance is reduced.

[0006] The discharge electrode needle of the present invention has a specific resistance of 5M.
A needle main body is manufactured from Ω / cm to 20 MΩ / cm zirconium oxide, a male screw is provided at a base end of the needle main body, and the male screw is screwed into a female screw of a short tubular needle holder made of stainless steel. It is preferable to use the main body in a structure held by a short tubular needle holder.

[0007]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a needle body 1 of a discharge electrode needle according to the present invention. The needle body 1 has a specific resistance of 5 MΩ / cm.
It is made of zirconium oxide of ２０20 MΩ / cm, and is provided with a male screw 2 on the outer periphery of the base end.

FIG. 2 shows a needle holder 3 for holding the needle body 1. The needle holder 3 is formed of a short tube made of stainless steel, and a female screw 4 is provided on a half portion of the inner peripheral surface thereof.
By screwing the male screw 2 of the needle main body 1 into the female screw 4, the needle main body 1 is used while being detachably (exchangeably) held on the needle holder 3.

FIG. 3 shows an example in which the above-mentioned discharge electrode needle is applied to an air gun type static eliminator. The discharge electrode needle holding the needle body 1 in the needle holder 3 is installed at the center of the nozzle 4 serving as the ground electrode. In this static eliminator, an oscillating circuit 6 is oscillated by a DC power supply 5, a high-frequency high voltage is output from a high-frequency transformer 7, and applied to the needle holder 3 via a capacitor 8 and a resistor 9 for controlling discharge current. As a result, a discharge is generated between the needle body 1 and the nozzle 4, and positive and negative ions generated by the discharge are blown to the object to be neutralized together with air.

[0011]

According to the present invention, since the needle body is made of zirconium oxide having a specific resistance of 5 MΩ / cm to 20 MΩ / cm, the following effects can be obtained. Since zirconium oxide has high abrasion resistance, there is almost no generation of metal particles due to abrasion. Since zirconium oxide, a metal with a relatively high specific resistance, was selected as the material of the needle body, abnormal discharge such as spark discharge can be suppressed by the resistance value of the needle itself, and stable discharge characteristics can be maintained for a long time. . Among the zirconium oxides, the specific resistance value is 5 MΩ / c
Since we chose zirconium oxide of m ~ 20MΩ / cm,
Electric shock can be prevented by the needle itself while sufficiently securing a discharge current required for static elimination. Since zirconium oxide has high strength, there is little breakage during handling.

[0012] An external thread is provided at the base end of the needle main body, and the external thread is screwed into the internal thread of the stainless steel short tubular needle holder to hold the needle main body in the short tubular needle holder.
Replacement of the needle body and connection to a high-voltage power supply can be easily performed.

[Brief description of the drawings]

FIG. 1 is a front view of a needle main body of a discharge electrode needle according to the present invention.

FIG. 2 is a cross-sectional view of a state where the needle main body is held by a needle holder.

FIG. 3 is a block diagram showing an example in which the discharge electrode needle of FIG. 2 is applied to an air gun type static eliminator.

[Explanation of symbols]

 1 Needle body 2 Male screw 3 Needle holder 4 Female screw

Claims (2)

[Claims] (1) a specific resistance value of 5 MΩ / cm to 20 MΩ / c;
A discharge electrode needle characterized in that the needle body is made of zirconium oxide. 2. A material having a specific resistance of 5 MΩ / cm to 20 MΩ / c.
The needle body is made of zirconium oxide having a length of m, a male screw is provided at the base end of the needle body, and this male screw is screwed into a female screw of a stainless steel short tubular needle holder to attach the needle body to the short tubular needle holder. A discharge electrode needle, wherein the discharge electrode needle is held.