JPH0118202Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrostatic coating device, and more particularly to an electrostatic coating device using a conductive coating material such as a slurry paint, a water-soluble paint, or a water-soluble oil coating material.

This type of electrostatic coating equipment is used, for example, in the final process of forming plate-shaped articles such as steel plates, aluminum plates, copper plates, etc., to prevent rust, improve machinability, or prevent scratches that may occur during transportation. There is an electrostatic coating device (electrostatic oil coating device) that electrostatically applies a water-soluble lubricant to form a thin oil film. Oil is vaporizable and forms a gas film on the surface of steel plates, etc., and requires only a relatively small amount of oil to obtain a rust-preventive effect. When removing rust preventive oil etc. and printing etc. on its surface, if it is a water-insoluble rust preventive oil such as mineral oil, it must be degreased with a strong surfactant etc. However, water-soluble antirust oils have become increasingly popular in recent years because they have the advantage of being extremely easy to degrease and can be quickly removed. In addition to the above-mentioned water-soluble oil coating materials, so-called water-based paints such as slurry paints and water-soluble paints have been used in electrostatic coating devices from the viewpoint of resource saving, energy saving, and pollution prevention.

By the way, conductive coating materials such as water-based paints and water-soluble oil coating materials have low electrical resistance, so they are supplied to an electrostatic coating machine (electrostatic coating machine) to which a predetermined high voltage is applied. In this case, if the coating material supply system is grounded, a current will flow through the coating material supply system,
Since the required high voltage is not applied to the electrode tip of the electrostatic coating machine, it is necessary to cut off the high voltage somewhere in the coating material supply system. That is, it is necessary to supply a conductive coating material in an electrically insulated state to an electrostatic coating machine to which a high voltage is applied.

Figure 1 shows a conventional electrostatic coating machine T that is configured to supply a conductive coating material in an electrically insulated state as described above to an electrostatic coating machine T to which a high voltage of approximately 30 to 100 KV is applied. FIG. 1 is a system diagram showing a schematic configuration of an electric coating device.

The conventional apparatus shown in FIG. 1 is designed to supply the conductive coating material while maintaining it in an electrically insulated state.

In other words, in the coating material supply system that supplies conductive coating material to an electrostatic coating machine to which high voltage is applied, the coating material supply hose, coating material supply tank, and the entire system are normally maintained at high voltage. Therefore, when the capacity of the coating material supply tank must be increased, such as when continuous coating is required or a large discharge amount is required, such as in automatic coating equipment, electric shock to the human body, which depends on the capacitance of the coating material supply system, can be avoided. Moreover, leakage current from the surface of the coating material supply tank increases, causing a voltage drop.Furthermore, the larger the coating material supply tank, the larger the area occupied by the coating material supply system. At the same time, the problem arises that the insulating support mechanism becomes larger and more complicated, but the conventional device shown in FIG. 1 has been improved to solve these problems.

The structure and operation of the conventional device shown in FIG. 1 will be briefly explained below.

In the figure, 1 is a coating material replenishment tank containing a conductive coating material such as slurry paint, 2 is a coating material feeding device such as a roller pump that pumps the conductive coating material in the coating material supply tank 1, and 3 is a conductive coating material. 5 is a support stand that supports the coating material dispersion device 3; 6 is a high voltage generator that applies a high voltage to the coating material supply tank 4; A voltage generator 7 is a coating material supply device such as a roller pump that pumps the conductive coating material in the coating material supply tank 4 to the electrostatic coating machine T via a coating material supply hose 8 which also serves as a high voltage cable. , a liquid level control device (not shown) controls the coating material in the coating material supply tank 1 so that the water level in the coating material supply tank 1 is kept constant according to the amount of coating material reduced in the coating material supplying device 2. , and is configured to be fed in a required amount to a coating material supply tank 4 via a coating material dispersing device 3.

Here, the coating material dispersion device 3 is made of an insulating material such as Delrin, and the coating material supply tank 4
A jet nozzle 10 is ejected by compressed air supplied through an air hose 9 which is disposed to face the liquid level of the coating material stored therein and is connected to a compressed air supply source (not shown). The coating material is dispersed and atomized into relatively coarse particles.

Also, a coating material supply tank 4 to which high voltage is applied
The coating material feeding device 7 is supported by insulators 11 and 12, respectively, and is electrically insulated from surrounding ground potential objects.

The high voltage applied to the coating material supply tank 4 by the high voltage generator 6 is then applied to the coating material supply hose 8.
It will be applied to the electrostatic coating machine T via
The coating material is electrostatically atomized and sprayed from the electrostatic atomizer T, and the coating material in the coating material supply tank 1 is continuously and seamlessly transferred to the coating material supply tank 4 to which a high voltage is applied. Since the coating material dispersing device 3 supplies coarse particles from the jet nozzle 10 of the coating material dispersing device 3 instead of dropping the coating material dispersing device 3 to the coating material supply tank 4, there is no electricity between the coating material dispersing device 3 and the coating material supply tank 4. They are isolated and isolated from each other and high voltage is cut off.

Therefore, since no high voltage is applied to the coating material supply system from the coating material dispersion device 3 to the coating material supply tank 1, even if a large capacity tank is used as the coating material supply tank 1, there will be no damage from the surface. Not only will there be no voltage drop at the tip of the electrode of the electrostatic coating machine T due to current leakage, but the risk of electric shock to the human body can also be reduced, and there is no need to insulate and support the coating material supply tank 1. There is an advantage.

However, even with the conventional device improved in this way, high voltage is applied to at least the coating material supply tank 4, coating material supply hose 8, and coating material feeding device 7, and therefore there is still a risk of electric shock to the human body. Gender issues remain.

That is, at present, the coating material supply tank 4 and the coating material feeding device 7 are supported by insulators 11 and 12, respectively, and are fixedly installed on the floor surface of the painting room. When an object approaches, there is a risk of electric shock due to electrical discharge.In particular, if a discharge occurs from the coating material supply hose 8, which also serves as a high voltage cable, to a grounded object, the impact may damage the sheath of the coating material supply hose 8. There is a problem that the items may be damaged.

In addition, in an electrostatic coating device, for example, an electrostatic coating device that electrostatically applies lubricating material such as rust preventive oil to a plate-shaped object such as a steel plate, etc. There is a type of electrostatic oil applicator in which an electrostatic oil applicator is installed in an oil application chamber in which an outlet is formed. It is configured to be freely configured and to be retreated from the conveyance line for maintenance and inspection after completion of oiling work. In this case, for example, the coating material supply hose, such as the coating material supply hose 8, which also serves as a high voltage cable connected to the electrostatic oil applicator disposed in the oil coating chamber, simply moves the oil coating chamber. Not only is it difficult to close the chamber because it requires a length corresponding to the distance, but the repeated bending caused by the movement of the oil application chamber back and forth causes fatigue, which impairs durability. In particular, when a large diameter hose that is difficult to bend is used as the coating material supply hose, there is a problem that the hose deteriorates rapidly and has extremely poor durability.

Therefore, the present invention is designed to keep the coating material supply tank 4, coating material feeding device 7, and coating material supply hose 8 in an electrically insulated state, and to coat the coating material supply tank 4, coating material supply device 7, and coating material supply hose 8, which are exposed to high voltage and have the risk of electric shock as described above. By housing it in the chamber, it eliminates the risk of electric shock to the human body due to these, and at the same time fixes the coating material supply hose connected between the electrostatic coating machine and the coating material supply tank in a fixed position. It is an object of the present invention to solve the problem of deterioration of the coating material supply hose due to movement of the coating chamber.

To achieve this objective, the present invention provides an electrostatic coating machine to which a high voltage is applied from a high voltage generator via a high voltage cable to a coating material supply tank which is maintained in an electrically insulated state. In an electrostatic coating device for conductive coating material, which is configured such that the conductive coating material is fed by a feeding device through a coating material supply hose, the coating can move freely forward and backward from the conveyance line of the object to be coated. The inside of the chamber is divided into two by a partition wall,
a coating material spraying chamber in which a loading/unloading port for loading and unloading the object to be coated is formed and the electrostatic coating machine is disposed so as to face the object to be coated; and a coating material spraying chamber adjacent to the coating material spraying chamber via the partition wall. A coating material supply chamber is formed in which the conductive coating material is supplied with the high voltage cut off, and the coating material supplying device and the coating material supplying device are each maintained in an electrically insulated state. and disposed within the coating material supply chamber.

Hereinafter, the present invention will be explained based on embodiments shown in the drawings.

FIG. 2 is a sectional view from the front showing an example of an electrostatic oil applicator as an electrostatic coating apparatus according to the present invention, and FIG. 3 is a sectional view from the top.

In the figure, C is a painted chamber (in this case, an oiled chamber), and the inside thereof is made of vinyl chloride, for example.
It is divided into two parts by a partition wall 13 made of an insulating material such as acrylic, epoxy, polyethylene, polypropylene, acetal resin, or fluororesin to form a lubricant spray chamber 14 and a lubricant supply chamber 15. A running wheel 16 is fixed to the bottom,
It is configured to be movable on rails 17.

The oil-coating material spraying chamber 14 is formed with an inlet 19 and an outlet 20 for carrying in and out an oil-coated article 18 such as a steel plate that is transported at a required speed. Electrostatic oil applicators T are disposed facing each other on the upper and lower surfaces. The electrostatic oil applicator T is
Case body 21 with built-in air motor (not shown)
and a cup-shaped body 23 fixed to the tip of the rotary shaft 22 of the air motor to be driven to rotate at high speed and to which a high voltage is applied. Fixed to the ceiling and floor. In addition, 26 is an electrostatic oil applicator T arranged upward on the floor of the oil applicator chamber C.
This is a flange-shaped cover that is fitted into the insulating support 24 of the insulator 25 and attached to the top of the insulator 25.

Further, 27 is a protective cover for preventing conductive oil particles sprayed from the electrostatic oil applicator T from adhering to the insulating support 24 and the insulator 25 and causing insulation defects. , is formed into a rectangular shape from an insulating material, and is provided with a circular through hole 28 at a predetermined position through which the electrostatic oil applicator T is inserted and which serves as an air outlet to be described later. This protective cover 2
7 is fixed to the inner wall and bulkhead 13 of the oil application chamber C with its peripheral edge fixed at a required distance parallel to the ceiling and floor of the oil application chamber C, thereby connecting the protective cover 27 and the oil application chamber C. A positive pressure chamber 29 is formed between the ceiling or floor of the vehicle, into which a required amount of air is introduced from an air supply fan (not shown) to maintain a positive pressure state.

On the other hand, in the lubricant supply chamber 15 adjacent to the lubricant spraying chamber 14 via the partition wall 13, there is a lubricant supply tank 30, which is separated from the liquid level of the lubricant stored in the tank 30. A lubricating material dispersing device 31 and a lubricating material feeding device 33 that feed the lubricating material in the lubricating material supply tank 30 to the electrostatic lubricating machine T via the lubricating material supply hose 32 are arranged. are arranged respectively.

The lubricating material supply tank 30 is placed on a tank pedestal 36 that is vertically movably supported on the top of an insulator 34 fixed to the floor of the lubricating chamber C via a spring 35.

The lubricant dispersion device 31 includes a lubricant supply tank 30
A lubricant is fed under pressure from a lubricant replenishment tank (not shown) suspended above and disposed outside the lubricant chamber C via a lubricant supply hose 37, which is then used as a compressed air supply source ( The lubricant is dispersed and atomized into relatively coarse particles by compressed air supplied through an air hose 38 connected to the lubricant supply tank 30 (not shown).

The tank pedestal 36 on which the lubricant supply tank 30 is mounted controls a pump 39 that is inserted into the lubricant supply hose 37 and pumps the lubricant, so that the oil in the lubricant supply tank 30 is controlled. An actuator 42 is attached that comes into contact with and separates from a limit switch 41 connected to a liquid level control device 40 for keeping the water level of the lubricant constant.
The spring 35 elastically contracts or springs in accordance with the increase or decrease of the lubricant stored in the lubricant supply tank 30, and the tank holder 36 moves up and down, causing the actuator 42 to act on the limit switch 41 and apply the lubricant. The water level of the lubricant in the lubricant supply tank 30 is always maintained constant.

The lubricant supply device 33 includes a lubricant supply hose 32
The pump 43 is inserted into the lubricating material supply tank 30 and pumps the lubricating material in the lubricating material supply tank 30 to the electrostatic lubricating machine T, and the electric motor 44 that drives the pump 43. The pump is placed on a pump pedestal 46 constructed above an insulator 45 fixed to the floor surface of the pump.

The lubricating material supply hose 32 has one end connected to the pump 4.
3 to the lubricant supply tank 30, and the other end is branched in the middle, and is inserted into the retractable insulator 47 which is inserted through the partition wall 13 from inside the lubricant supply chamber 15, and is connected to the lubricant spraying chamber 14. It extends into the positive pressure chamber 29, and each branch end is connected to an electrostatic oil applicator T, respectively.

In addition, in this embodiment, the lubricating material supply chamber 15
In addition to the lubricating material supply tank 30, lubricating material feeding device 33, and lubricating material dispersing device 31, a high voltage generator 48 is also disposed at the same time, and the high voltage cable 4
Similarly to the case where 9 is the lubricant supply hose 32,
The retractable insulator 50 is inserted through the partition wall 13 and extends from the inside of the lubricating material supply chamber 15 into the positive pressure chamber 29 of the lubricating material spraying chamber 14, and its ends are connected to the electrostatic lubricating machine T, respectively. It is connected.

The above is the configuration of the electrostatic oil applicator shown in this embodiment, and its operation will be explained next.

When applying electrostatic oil to the object 18 to be oiled that is being conveyed at a required speed, first the electrostatic oil applicator T is operated to drive the cup-shaped body 23 to rotate at a high speed.

At the same time, the high voltage generator 48 connects the electrostatic oil applicator T via the high voltage cable 49 to DC, for example.
While applying a high voltage of about -80 to 120KV,
The lubricating material feeding device 33 is operated to supply the lubricating material stored in the lubricating material supply tank 30 to the electrostatic lubricating machine T via the lubricating material supply hose 32.

As a result, the lubricant supplied to the electrostatic lubricator T is atomized and sprayed from the tip of the cup-shaped body 23 by electrostatic force and centrifugal force, and
The surface will be electrostatically oiled.

Here, the lubricating material supply hose 3 is connected to the electrostatic lubricating machine T to which a high voltage for electrostatically atomizing the lubricating material is applied.
Even if the conductive lubricant is supplied through the conductive lubricant 2, the lubricant supply tank 30 and lubricant feeder 33 to which high voltage is applied through the conductive lubricant are insulators 34 and 45, respectively. The lubricating material supply tank 30 and the lubricating material dispersing device 31 are electrically insulated and separated, and high voltage is cut off, and the lubricating material dispersing device 31 is supported and maintained in an electrically insulated state. Since no high voltage is applied to the lubricating material supply system leading to the lubricating material supply tank via the lubricating material supply hose 37,
There is no voltage drop at the electrode tip of the electrostatic oil applicator T due to current leaking from the surface of the large-capacity lubricating material replenishment tank, and there is no need to insulate and support the replenishment tank.

In particular, in the device of the present invention, the lubricant supply tank 30 and the lubricant feeder 33, which are maintained at a high voltage, are both formed in the lubricant chamber C.
5, there is no fear that a human body or other grounded object will be exposed to electric shock in close proximity, and the lubricating material supply hose 32 can be fixed and arranged in a well-organized manner, and the lubricating material supply hose 32 can be installed in Even when the hose C is moved on the rail 17 to advance and retreat from the conveyance line of the object to be oiled 18, the length corresponding to the moving distance is not required as in the conventional case, and a large diameter hose is used. Of course, there is no deterioration due to bending,
Its durability is significantly improved.

Although this is not an effect of the present invention, when the conductive lubricant is sprayed in the lubricant spraying chamber 14, a required amount of air is introduced into the positive pressure chamber 29 to maintain a positive pressure state. Through hole 28 through which the electrostatic oil applicator T is inserted
Since air is blown out from the electrostatic oil applicator T
Conductive lubricating material particles sprayed and floating enter the positive pressure chamber 29 and insulate the insulating support 2 of the electrostatic lubricating machine T.
4 and the insulator 25 to cause insulation defects.

In addition, conductive lubricating material particles adhering to the surface of the electrostatic lubricating machine T fixed upward on the floor of the lubricating chamber C may flow down in the form of droplets. A collar-shaped cover 26 is attached to the top of the insulator 26 to prevent conductive lubricant from adhering to the surface of the insulator 26 and causing insulation failure.

In the above-mentioned embodiment, the conductive lubricant is used as a means for replenishing the lubricant from the lubricant supply tank constituting the lubricant supply system to the lubricant supply tank 30 with the high voltage cut off. Although the case has been described in which the lubricating material dispersing device 31 that disperses and atomizes and supplies the lubricant is applied, the present invention is not limited to this, and other known means may be applied.

In addition, in the embodiment, an electrostatic oil applicator that electrostatically atomizes a conductive lubricant such as a water-soluble rust preventive oil by a so-called bell-shaped electrostatic oil applicator T having a cup-shaped body 23 will be described. However, it goes without saying that the present invention can also be applied to general electrostatic coating equipment that uses conductive paints such as slurry paints and water-soluble paints.

As described above, according to the present invention, a coating material supply tank and a coating material feeding device maintained at a high voltage are formed in a coating chamber separated from a coating material spraying chamber by a partition wall. Because it is located in the material supply room, there is no risk of a human body or other grounded object coming close to the coating material supply system and receiving an electric shock, unlike in the conventional case. This has the excellent effect that the coating material supply hose that supplies the coating material can be fixedly disposed with good finish, and its durability can be significantly improved.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing a conventional electrostatic coating device for conductive coating materials, FIG. 2 is a sectional view from the front showing an example of the electrostatic coating device for conductive coating materials according to the present invention Figure 3 is a sectional view seen from the plane. Explanation of symbols, C...painting chamber (oil application chamber), T...electrostatic coating machine (electrostatic oil coating machine), 13...
Partition wall, 14... Coating material spraying chamber (oil coating material spraying chamber),
15... Coating material supply chamber (oil coating material supply chamber), 18...
...Object to be coated (object to be oiled), 30...Coating material supply tank (oiling material supply tank), 32...Coating material supply hose (oiling material supply hose), 33...Coating material feeding device ( 34, 45... Insulator, 48... High voltage generator, 49... High voltage cable.

Claims (1)

[Scope of utility model registration request] A coating material is supplied from a coating material supply tank 30 maintained in an electrically insulated state by a coating material feeding device 33 to an electrostatic coating machine T to which a high voltage is applied from a high voltage generator 48 via a high voltage cable 49. hose 32
In an electrostatic coating device for a conductive coating material, which is configured such that the conductive coating material is fed through a partition wall 13, the interior of the coating chamber C, which can move forward and backward with respect to the conveyance line of the object to be coated 18, is connected to the partition wall 13. Thus, the coating material spraying chamber 14 is divided into two parts, and has a loading/unloading port 20 through which the object 18 to be coated is carried in and out, and in which the electrostatic coating machine T is disposed so as to face the object 18 to be coated; A coating material supply chamber 15 is formed adjacent to the coating material spraying chamber 14 via a partition wall 13, and the coating material supply tank 30 is provided with the conductive coating material while the high voltage is cut off. An electrostatic coating device for a conductive coating material, characterized in that a material feeding device 33 is arranged in the coating material supply chamber 15 while being maintained in an electrically insulated state.