JPH0884948A - Coating booth for car - Google Patents

Abstract

PURPOSE: To neutralize the electrostatic charge of a coated face or scattered dust and thereby obtain a flawless, dust-free coat by arranging an ionized gas generator in an air inflow duct for a coating booth, in the coating booth for the car which eliminates a static electricity from a face to be coated as a pre-coating treatment step. CONSTITUTION: An air inflow duct 3 is arranged on the ceiling of a coating booth 1 ad a forced discharge duct on the floow. In addition, an atmospheric air is supplied to the interior of the coating booth by activating a discharge fan 8, and an ionized gas generator 2 is arranged forward of an air filter 4 in the air inflow duct 3. This ionized gas generator 2 generates a corona discharge by applying a high frequency high voltage to an area between electrodes to ionize an air. When the ionized gas thus generated passes through the filter 4, fine particles captured by an electrostatic charge are neutralized, and these neutralized fine particles are conducted to the coating booth 1. Further, the coated face is neutralized by the ionized gas, and dust is blown off by blasting a compressed air onto the coated face under such a neutralized state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating booth for automobiles or the like in which a coating booth is filled with ionized gas to remove static electricity on the coating surface as a pretreatment for coating.

[0002]

2. Description of the Related Art Sheet metal painting work for automobiles involves repairing the damaged body surface by sheet metal work, making a paper sound, further polishing the surface with a cloth coated with silicone off, and moving it into a painting booth for polishing. Dust adhering to the finished surface is scattered with an air gun, and this partially coated surface is painted. Since a large amount of dust (dust) is adsorbed by the static electricity charged on the coating surface after drying,
This dust is removed one by one with a paper sound.

[0003]

The surface of the coating film, which is an insulator, is apt to generate static electricity, and dust adhering thereto is not sufficiently removed even when air is blown out by an air gun. Rather, the jet stream rubs against the coating film, so that static electricity is generated on the surface of the coating film, and dust floating in the repair area adheres to this surface. Fresh air is always supplied to the coating booth, but it is not dust-free. Dust floating in this booth and dust generated when using an air gun are usually charged. Dust floating during coating adheres to the surface of the charged coating film and reduces coating quality.

[0004]

Means for Solving the Problems An ionization gas generator such as a static elimination gun is arranged in an air inflow duct of a coating booth.
This ionized gas generator, which is placed in front of the air filter, is connected to a compressed air pipe connected to the compasser and a high voltage electric wire extending from a high voltage power source. A forced discharge duct equipped with a spray nozzle is placed on the floor of the coating booth.

[0005]

[Function] The suction fan of the air inflow duct and the exhaust fan of the forced exhaust duct constantly work to flow fresh air into the coating booth. Due to the filtering action of the air filter, dust floating in the coating booth is reduced. When high frequency and high voltage from a high voltage power supply is applied between the needle electrode and the counter electrode of the static eliminator gun, the air passing through it is ionized by air discharge breakdown (corona discharge). This ionized gas is supplied into the coating booth through an air filter. Due to this ionized gas, the electrostatic charge of the floating and charged dust becomes zero (referred to as neutralization), and the dust is smoothly guided to the forced exhaust duct without adhering to the inner wall of the coating booth or the coating surface of the automobile. The electrostatic charge on the painted surface of the car in the paint booth is also neutralized. As a pretreatment for painting, compressed air is blown onto the surface to be painted to scatter dust. Since the electrostatic charge on the coated surface has already been neutralized, dust easily disperses. The dust that has been scattered by the ionized gas is once charged but is immediately neutralized, and is guided to the forced exhaust duct without reattaching to the surface to be coated.

[0006]

[Example] An air inflow duct 3 is installed on the ceiling of the coating booth 1.
A forced exhaust duct 7 is arranged on the floor surface, and fresh air is constantly supplied into the coating booth by an exhaust fan 8 and a suction fan (not shown). Air filter 4 in this air inflow duct
The ionized gas generator 2 is arranged in front of. The ionized gas generator applies high frequency and high voltage between the facing electrodes to cause air discharge breakdown (corona discharge) and ionize air. The high voltage power supply 5 generates a high voltage of about 7,000 volts. A static elimination gun 11 as the ionized gas generator 2 is shown in FIG. A plurality of needle electrodes 13 are radially arranged around the counter electrode 12 to obtain a uniform ion distribution. The compressed air pipe 6 connected to a high-pressure air generator such as a compressor is connected to the tubular counter electrode 12.

The generated ionized gas is the air filter 4
When passing through, it neutralizes the fine particles (very small dust) captured by the electrostatic charge and guides them to the coating booth.
Since these particles are so small that they originally pass through the air filter, they accumulate in the air filter after long-term use. The released particulates are forced exhaust duct 7
Released immediately from. After a predetermined time, the coating booth is filled with ionized gas. The charged coating surface is neutralized by this ionized gas. Blow compressed air onto the surface to be painted or the masking area to blow off the dust that had adhered. The surface potential of the clean coated surface after this pretreatment is always kept at zero by the ionized gas in the coating booth.

The dust blown off by the exhaust fan 8 at the exit of the forced exhaust duct 7 is exhausted to the outside of the coating booth. A spray nozzle 9 and a filter are arranged in the forced discharge duct. These are to deal with pollution problems. When a resin gun or water-based paint is sprayed onto the cleaned surface to be painted using a paint gun, harmful volatile components such as thinner and paint powder float in the paint booth. These are guided to the forced discharge duct 7, and the circulating water in the duct is sprayed from the spray nozzle 9 to be adsorbed and captured. Since the electrostatic potential of the surface to be coated and the dust that floats is zero (neutralization), there is no risk of dust reattaching during painting. The paint applied to the surface to be coated is evenly dispersed. If dust adheres to the painted surface, the applied paint wraps around the dust and the coating film distribution becomes uneven.
After painting, this dust will be removed by applying paper, but this work requires meticulous attention and time.
In the case of a metallic paint in which fine metal particles are dispersed, the fine metal particles are non-uniformly dispersed when the coated surface is charged with an electrostatic charge. This is the reason why metallic coating is difficult. In the present invention, since the coated surface is not charged, the fine metal particles are uniformly dispersed and a fine coating finish is possible.

In the embodiment shown in FIG. 3, an electrode is printed on the back surface of an alumina substrate 16, and a high frequency power source 14 with a built-in high voltage transformer is connected to an ion generator having a titanium electrode 15 attached to the surface thereof. It is arranged in the inflow duct 3. No compressed air is needed. The ionized gas generator 2 may be an appropriate place in the coating booth.

[0010]

In summary, according to the present invention, since the ionized gas generator is arranged in front of the air filter in the air inflow duct and the forced exhaust duct is provided under the floor of the coating booth, the coating booth is filled with the ionized gas during the pretreatment of coating. However, the electrostatic charge of the surface to be coated or dust that scatters can be neutralized, and an excellent coating film without dust adhesion can be provided. The time required to remove dust on the repainted surface has been significantly shortened, and the coating quality and work quality have been greatly improved.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of a state where a coating booth is filled with ionized gas.

FIG. 2 is a cross-sectional view of a static eliminator gun.

FIG. 3 is an explanatory diagram of an ion generator.

[Explanation of symbols]

 1 Painting booth 2 Ionized gas generator 3 Air inflow duct 4 Air filter 7 Forced exhaust duct

Claims (4)

[Claims] 1. A coating booth for an automobile or the like in which an ionized gas generator is arranged in an air inflow duct of the coating booth. 2. A coating booth for an automobile or the like in which an ionized gas generator is arranged in front of an air filter in an air inflow duct, and a spray nozzle is provided in a forced exhaust duct 7 under the floor of the coating booth. 3. A coating booth for an automobile or the like in which a static elimination gun is arranged in an air inflow duct of the coating booth, and compressed air and an output line of a high-voltage power source are guided to the static elimination gun. 4. A coating booth for an automobile or the like in which an ionized gas generator is arranged in the coating booth to ionize the gas in the coating booth.