JPS6056538B2 - electrostatic coating equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrostatic coating device that can electrostatically coat both metallic paint and solid paint.

Conventionally, when electrostatically painting metallic paints, the metal powder contained in the metallic paints is connected to each other in a chain due to the influence of the high voltage (usually 90,000 Vo) applied to the electrostatic paint machine. However, there is a difficulty in that a bridging phenomenon (or pearl chain phenomenon) occurs in which high voltage is lost through the chain metal powder.

If high voltage is lost due to the formation of chain metal powders, not only will the essential functions of electrostatic coating be impaired, but also accidents such as fires will easily occur because arcs are likely to occur between the metal powders in the paint. It will become. In order to prevent the formation of the bridging phenomenon described above, it is possible to supply metallic paint to an electrostatic sprayer using an electrically insulating hose with a small diameter that makes it difficult for metal powder to form a chain. When using an insulating hose, it is extremely difficult to supply the necessary amount of solid paint, which has a much higher viscosity than metallic paint, to an electrostatic sprayer.

However, in the past, although there were industrially multicolored paints with different characteristics, both metallic paints and solid paints were mixed and supplied in the same paint supply color change cleaning equipment, so either The supply color change cleaning was performed while the characteristics of one paint system were lost, and it can be used for both electrostatic painting of metallic paints and electrostatic painting of solid paints, and is There has never been an electrostatic coating device that can secure the necessary and sufficient discharge amount and prevent the bridging phenomenon from occurring in the case of metallic paints. An object of the present invention is to provide an electrostatic coating method for metallic paints that can efficiently supply paints to an electrostatic coating machine without impairing any of the characteristics of paints of multiple colors with different characteristics. It is an object of the present invention to provide an electrostatic coating device that can be used in common with electrostatic coating of solid paints.

The basic structure of the present invention is that a color change cleaning device and an electrostatic coating machine are connected via an on/off valve, and a color change cleaning device for metallic paint is used in an electrostatic coating device that supplies paint. and a color change cleaning device for solid paint are provided separately, and an on/off valve corresponding to each color change cleaning device is provided, and a flow path between each color change cleaning device and each of the on/off valves is provided. The diameter of the flow path is small enough to prevent the bridging phenomenon from occurring in metallic paint systems.
For solid paint systems, this is an electrostatic coating device with a large diameter channel through which highly viscous paint can easily flow.

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows a first embodiment of the present invention, in which an electrostatic coating machine 1 is a rotary atomizing head type electrostatic coating machine having a rotating atomizing head 1a.

That is, the rotary atomizing head 1a is rotated (10,000 R.p.m. to 30,000 R.p.m.) by an air motor 1c supported by an insulating support 1b, and at the same time A high voltage (approximately 90,000 V) is applied to electrostatically atomize the supplied paint. The object to be coated (as shown) is
Naturally, it is located opposite the rotary atomizing head 1a. The electrostatic coating machine 1 is provided with a metallic paint supply system 2 for supplying metallic paint and a solid paint supply system 3 for supplying solid paint independently from each other,
Each of these supply systems 2, 3 is constructed with a flexible hose made of electrically insulating material.

The supply system 2 is connected to a color change cleaning device 4 for metallic paint, and air is provided in the supply system 2 between the color change cleaning device 4 and the electrostatic coating machine 1 and in the vicinity of the electrostatic coating machine 1. An operated on-off valve 5 is interposed. The color change cleaning device 4 includes valve devices V1 to Vn! for turning on and off the metallic paints of colors A to N, respectively. Further, an air valve A1 and a thinner valve TH are interposed between the circulation systems X and Y for supplying cleaning fluids such as air and thinner and the above-mentioned supply system 2.
have. Portions 2a and 2b of the supply system 2, which are located on both sides of the on-off valve 5, are connected to small-diameter hoses that tend to cause bridging (e.g., hose inner diameter φ3.5 or less, hose length 800 or more), but the only part that needs to be a small diameter hose is the part 2b. The reason is that the on-off valve 5 is
Even if a high voltage is applied to the range up to , the portion 2b of the supply system 2 maintains electrical insulation, so the high voltage applied to the rotary atomizing head 1a will not be lost. This is because there is no such thing. On the other hand, a supply system 3 for supplying solid paint to the electrostatic coating machine 1 is connected to a color change cleaning device 4'' for solid paint.

An air-operated on-off valve 5'' is interposed in the supply system 3 between the color change cleaning device 4'' and the electrostatic coating machine 1 and in the vicinity of the electrostatic coating machine 1. The color change cleaning device 4'' has valve devices V1'' to Vn'' for turning on and off the solid paints of colors a' to n'', respectively, and also has air and thinner as cleaning fluids. It has an air valve A1 and a thinner valve TH interposed between the supply circulations x' and Y' and the above-mentioned supply system 3. Supply system 3 on-
Portions 3a and 3b of the supply system 3 are located on both sides of the off-valve 5.
b must both be constructed with electrically insulating hoses of large diameter. The reason for this is to reduce the flow path resistance of the solid paint. The operation of the first embodiment will be explained below.

Now, in order to electrostatically paint the metallic paint color a, both the valve device V1 and the on-off valve 5 are opened, and at the same time, the paint of color a is supplied to the electrostatic coating machine 1, and at the same time, the rotary atomizing head 1a
rotates while applying high voltage to the

Then, the a-color metallic paint is electrostatically atomized by the rotating atomizing head 1a, and is applied to an object to be coated (not shown). Next, in order to electrostatically apply metallic paint color B, first open the thinner valve TH and the air valve A in sequence, and then open the on-off valve 5 to open the rotary atomizing head. Air and thinner as cleaning fluids are supplied to 1a.

Here, the supply system 2 and the rotary atomizer head 1a are cleaned while rotating the rotary atomizer head 1a without applying a high voltage. When this cleaning is completed, the valve device V2 and the on-off valve 5 are opened to supply the paint of color b to the rotary atomizing head 1a, and a high voltage is applied to the rotary atomizing head 1a. The color b paint is electrostatically atomized by rotating it. Furthermore, when performing electrostatic coating of solid paint, the effect is exactly the same as in the case of electrostatic coating of metallic paint.

FIG. 2 shows a second embodiment of the present invention, in which components with the same reference numerals as in FIG. 1 indicate components with the same names and having the same functions.

This embodiment is characterized by the on-off valve 5,
5" is an integral structure, and furthermore, an on-off valve 5,5"
The paint supply system 6 from the to the electrostatic coating machine 1 is made common. Here, since solid paint and metallic paint flow together in the paint supply system 6, a large diameter electrically insulating hose is used to reduce the flow path resistance of the solid paint. Furthermore, the portion 2b is constructed with a small diameter electrically insulating hose, which is similar to the first embodiment. As explained above, according to the electrostatic coating device of the present invention, it is possible to efficiently supply both metallic paint and solid paint to a coating machine without impairing their characteristics, and it is possible to efficiently supply both metallic paint and solid paint to a coating machine. It is now possible to perform electrostatic painting with a machine,
Not only does the installation space for the device decrease, but also the supply of paint and color change/cleaning are performed smoothly, resulting in an increase in work efficiency such as a reduction in the time required for each process.

[Brief explanation of drawings]

FIG. 1 is a side view of essential parts showing a first embodiment of an electrostatic coating apparatus of the present invention, and FIG. 2 is a side view of essential parts showing a second embodiment of the present invention. 1... Electrostatic coating machine, 2... Metallic paint supply system, 3... Solid paint supply system, 4,
4...Paint/color change cleaning device, 5,5...
...On-off valve.

Claims (1)

[Claims] 1. In an electrostatic coating device that connects a color change cleaning device and an electrostatic coating device via an on/off valve and supplies paint,
A color change cleaning device for metallic paints and a color change cleaning device for solid paints are provided separately, and an on/off valve corresponding to each color change cleaning device is provided, and each color change cleaning device is connected to each of the on/off valves.・The diameter of the flow path leading to the off valve is small enough to prevent the bridging phenomenon from occurring in metallic paint systems, and large in diameter to allow high viscosity paint to flow easily in solid paint systems. Electrostatic coating equipment.