JP2528201B2 - Charging device for electrostatic coating - Google Patents

Description

TECHNICAL FIELD The present invention relates to a charging device for electrostatic coating that applies a high voltage to the side of an object to which a conductive coating such as a water-based coating is electrostatically coated.

[Conventional technology]

When applying a high voltage to the coating machine side and connecting the object side to earth, and performing electrostatic coating of conductive paint such as water-based paint, make sure that the high voltage applied to the coating machine does not leak. Since it is necessary to take insulation measures in the paint supply system of the conductive paint connected to the coating machine (JP-A-55-114366 and JP-A-56-1418).
No. 69 gazette), in the case of a multicolor coating device for automobile painting, which paints dozens of colors by changing colors, it is necessary to insulate the paint supply pipe and paint tank for each color paint. There is.

For this reason, in automotive painting, electrostatic painting with an insulating resin paint that consumes a large amount of harmful organic solvents occupies the mainstream, and at present the use of non-polluting water-based paint is withdrawn.

However, recently, the global movement for environmental conservation has increased,
The use of organic solvents that generate pollutants such as hydrocarbons in the coatings industry has been called for.

[Problems to be Solved by the Invention]

Therefore, the present invention applies a high voltage to the side of the article to be conveyed in an electrically insulated state when electrostatically coating a conductive coating such as a water-based coating, and connects the coating machine side to the ground for coating. At the same time as eliminating the trouble of applying insulation measures to the paint supply system of the machine,
A technical problem is to prevent spark discharge from being generated when a high voltage is applied to an object to be coated during transportation.

[Means for solving the problem]

In order to solve this problem, the present invention relates to a charging device for electrostatic coating that applies a high voltage to an object to be transferred that is conveyed in an electrically insulated state, in which a contactor that moves integrally with the object to be coated is provided. A current collecting rail for slidingly applying a high voltage to the object to be coated is provided, and along the current collecting rail, a portion of the contactor in sliding contact is covered with a nonflammable electric insulating oil. It is characterized in that a cover for storing insulating oil is provided.

[Action]

According to the present invention, when a high voltage is applied from the current collecting rail via the contactor to an object to be coated conveyed in an electrically insulated state, an electrostatic field is generated between the object to be coated and the coating machine connected to the ground. By the action of the electric field formed, the paint particles sprayed from the coater are sucked and adsorbed on the surface of the article to be coated.

Therefore, even when a conductive paint such as a water-based paint is electrostatically coated, it is not necessary to take troublesome insulation measures for the paint supply system of the coating machine.

Further, in the current collecting rail, the portion where the contact is slidably contacted is covered with the non-combustible electric insulating oil, so that there is no fear of causing a spark explosion accident due to the spark discharge generated between the current collecting rail and the contact.

〔Example〕

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

FIG. 1 is a front view showing an example of a charging device for electrostatic coating according to the present invention, and FIG. 2 is a sectional view taken along the line AA.

In this example, along the coating zone Z in which the coating machine connected to the ground is installed, the insulating conveyor 1 that carries each of the objects W to be coated on the insulating carriage 2 and conveys them in an electrically insulated state, and the insulating carriage 2
There is provided a charging device 3 for electrostatic coating that applies a high voltage to the object W to be transported by.

The charging device 3 slides the contacts 4 provided on each insulating trolley 2 on the object W to be coated on each insulating trolley 2 to make a contact with the contactor 4.
A current collecting rail 5 for applying a high DC voltage of about 120 KV is provided, and contacts 4 are provided along the current collecting rail 5.
The non-flammable electrical insulating oil 6 is used to cover the part where
A cover 7 for storing the electric insulating oil 6 is provided so as to be covered with a liquid phase of about m.

The current collecting rail 5 is fixed horizontally to the upper ends of the insulating columns 8, 8 ... Standing at a predetermined interval along the coating zone Z, and both ends thereof are about 0.5 to 2 m long. 500 ~
It is made of 5000 MΩ high resistance material.

Further, the contactor 4 is formed of a metal leaf spring, a chain, or the like, and is brought into sliding contact with the surface of the current collecting rail 5.

Further, the cover 7 is formed with a slit 9 for inserting the contactor 4 of the insulating carriage 2 on the upper surface thereof, and a supply pipe 10 for electric insulating oil and an overflow pipe 11 for discharging excess electric insulating oil on the side surface. Are opened and connected in the cover 7.

Further, as the electric insulating oil 6, for example, mineral oil, silicone oil, or mixed oil of mineral oil and alkylbenzene is used.

Therefore, a high voltage is applied from the current collecting rail 5 to the object W to be coated on the insulating trolley 2 of the insulating conveyor 1 and conveyed in the coating zone Z via the contacts 4 provided in each insulating trolley 2. An electrostatic field is formed between the article W to be coated and a coating machine connected to the ground, and the electric field action causes the paint particles sprayed from the coating machine to be sucked and adsorbed on the surface of the article W. .

Therefore, even when performing electrostatic coating with a conductive coating such as a water-based coating, it is not necessary to take troublesome insulation measures in the coating supply system of the coating machine.

Further, since the surface of the current collecting rail 5 is covered with the electric insulating oil 6 stored in the cover 7, when the contactor 4 of the insulating trolley 2 is in sliding contact with the current collecting rail 5 or during sliding contact, Spark discharge is unlikely to occur, and even if a spark discharge occurs, the spark does not go out.Therefore, air containing evaporated organic solvent flows in from other coating zones where an insulating resin paint such as clear paint is applied. However, there is no danger of ignition and explosion.

Therefore, since the object W to be coated can be safely coated while being continuously conveyed as usual, the coating productivity is not reduced.

Further, there is no possibility that the charged state of the article to be coated W becomes unstable due to the spark discharge and the surface of the current collecting rail 5 is oxidized and the durability thereof is impaired.

In particular, as described above, if both ends of the current collecting rail 5 are made of high resistance material, the spark discharge generated when the contactor 4 makes sliding contact is surely prevented.

〔The invention's effect〕

As described above, according to the present invention, even when performing electrostatic coating using a conductive coating material such as a water-based coating material, it is not necessary to take troublesome insulation measures for the coating material supply system of the coating machine, which increases equipment costs. Moreover, there is a very excellent effect that the electrostatic coating can be performed with high productivity and safety.

Therefore, the present invention is very useful because it can promote the shift from electrostatic coating with an insulating resin coating to electrostatic coating with a non-polluting water-based coating.

[Brief description of drawings]

FIG. 1 is a front view showing an example of a charging device for electrostatic coating according to the present invention, and FIG. 2 is a sectional view taken along the line AA. Explanation of reference symbols W: coating object, 1 ... insulation conveyor, 2 ... insulation carriage,
3 ... Electrostatic charging device, 4 ... Contactor, 5 ... Current collecting rail, 6 ... Electrical insulating oil, 7 ... Cover.

Claims (1)

(57) [Claims] 1. An article to be coated (W) conveyed in an electrically insulating state.
In a charging device for electrostatic coating that applies a high voltage to a substrate, a contactor (4) that moves integrally with the object to be coated (W) is brought into sliding contact to apply a high voltage to the object to be coated (W). A current collecting rail (5) is provided, and along the current collecting rail (5), a portion of the contactor (4) in sliding contact is covered with a nonflammable electric insulating oil (6). A charging device for electrostatic coating, comprising a cover (7) for storing (6).