JP2521102Y2 - Electrostatic coating equipment for conductive paint - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to an electrostatic coating apparatus for coating a conductive coating such as a water-based coating, a slurry coating or a metallic coating by an electrostatic coating machine to which a high voltage is applied. .

[Conventional technology]

When coating conductive paint such as water-based paint with an electrostatic coating device to which a high voltage is applied, insulate the paint supply system of the coating machine to prevent leakage of the high voltage applied to the electrostatic coating machine. It is necessary to take measures (Japanese Patent Laid-Open No. 55-1143).
No. 66, No. 56-141869), in a multicolor electrostatic coating device for automobile painting, in which dozens of colors of paint are recolored and painted, the paint supply pipes and paints for each paint of each color There is the trouble that the tank etc. must be insulated.

For this reason, in automobile coating, electrostatic coating with an insulating resin coating that consumes a large amount of harmful organic solvents still occupies the mainstream, and the fact is that the use of non-polluting water-based coatings is foreseen.

However, recently, the global movement for environmental conservation has increased,
In the paint industry as well, there are calls for regulations on the use of organic solvents that produce pollutants such as hydrocarbons.

[Problems to be solved by the device]

Therefore, the present invention recommends coating with a water-based paint, so even when conducting multicolor electrostatic coating with a conductive paint such as a water-based paint, a troublesome insulation measure for the paint supply system such as the paint supply pipe and the paint tank. The main technical issue is to eliminate the need for coating, shorten the cleaning time of the previous color paint in multicolor electrostatic coating, and reliably prevent the color mixture of the previous color paint and the next color paint. Doing this is also a technical issue.

[Means for solving the problem]

In order to solve this problem, the present invention relates to a conductive paint electrostatic coating apparatus for coating a conductive paint with an electrostatic coating machine to which a high voltage is applied, and a pump chamber having a paint inlet and a paint discharge port. Is formed of a bag-shaped film that can be filled with the required amount of conductive paint required for painting, and is displaced so as to squeeze and squeeze the expanded bag-shaped film that is filled with the conductive paint introduced from the paint inlet. A membrane pump that presses out the conductive paint from the paint discharge port at a predetermined flow rate according to the paint discharge amount of the electrostatic coating machine is installed in an electrically insulated state, and the paint is applied to the paint inlet. It is characterized in that the supply pipe is detachably connected.

[Action]

According to the present invention, when the high voltage is not applied to the electrostatic coating machine, the paint supply pipe is connected to the paint inlet of the membrane pump, and the pump chamber of the membrane pump formed by the bag-shaped membrane body is connected. Introduce conductive paint to.

Then, when the pump chamber is filled with the required amount of conductive paint necessary for painting, the paint supply pipe connected to the paint inlet is disconnected from the paint inlet, and the entire membrane pump is electrically insulated. To do.

In this state, a predetermined high voltage is applied to the electrostatic coating machine, and the bag-shaped film body forming the pump chamber of the membrane pump is displaced so as to be pressed and crushed to fill the bag-shaped film body. The conductive paint is squeezed out from the paint discharge port at a predetermined flow rate and supplied in a fixed amount to the electrostatic coating machine, and electrostatic coating with the conductive paint is started.

At this time, since the membrane pump and the paint supply pipe for supplying the conductive paint to the paint inlet of the membrane pump are separated from each other and electrically insulated, the high voltage applied to the electrostatic coating machine is It does not leak into the paint supply system of conductive paint such as supply piping.

Therefore, it is not necessary to take troublesome insulation measures for the paint supply system, and in a multicolor electrostatic coating apparatus having a paint supply system for dozens of colors, enormous equipment costs are not required for implementing the insulation measures. Become.

Next, when the conductive paint that is pressed out by the film from the membrane pump is used up and the coating with the paint is finished, the application of high voltage to the electrostatic coating machine is stopped and the same paint is applied inside the membrane pump. Refilling is performed, or in the case of a multicolor electrostatic coating apparatus, the previous color paint remaining in the membrane pump is washed and removed with a cleaning liquid or cleaning air, and then the next color paint is filled.

During this cleaning, the membrane pump does not have a piston that reciprocates in the cylinder, unlike a normal piston pump, so the pre-color paint remaining inside must be cleaned and removed at high speed without any color residue. You can

That is, in the piston pump in which the piston reciprocates in the cylinder, the paint adheres not only to the front side of the piston but also to the back side of the cylinder, and the inner peripheral wall of the cylinder and the piston slidingly contacting the inner peripheral wall of the piston. The paint is also attached to the packing, and if the paint is not removed by washing, the color mixture of the previous color paint and the next color paint may occur, so it takes time to wash the previous color paint. While the color change time from the end of painting of the color paint to the start of painting of the next color paint is long, the membrane pump that does not have a piston inside changes the color by performing high-speed washing. The time can be greatly reduced.

〔Example〕

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

1 and 2 are flow sheet diagrams showing an example of the electrostatic coating apparatus according to the present invention.

In FIG. 1, a membrane pump 2 for quantitatively supplying a conductive paint to an electrostatic coating machine 1 to which a high voltage of 80 to 120 KV is applied.
However, a bag-shaped film body 5 such as a bellows flam that is installed in an electrically insulated state, and whose pump chamber is attached and displaced at the tip of an insulating shaft 4 that is reciprocated by a driving device 3 such as a motor or an air cylinder is displaced. Formed and paint inlet 6
The conductive paint introduced from the above is squeezed out from the paint discharge port 7 at a predetermined flow rate according to the paint discharge amount of the electrostatic coater 1 and supplied to the electrostatic coater 1 in a fixed amount.

The paint inlet 6 is provided with a female coupler 8 for opening and closing the paint inlet 6, and the female coupler 8 is fixed at a fixed position.

Further, the paint supply pipe 9 which is detachably connected to the paint inlet 6 of the membrane pump 2 and supplies the conductive paint into the membrane pump 2 has its rear end side connected to the color changing valve device 10. A male coupler 11 which is detachably fitted to the female coupler 8 of the paint inlet 6 is provided on the tip side thereof, and the male coupler 11 is fixed to the piston rod 13 of the air cylinder 12 and The expansion and contraction of the rod 13 allows it to move back and forth from the required insulation distance toward the female coupler 8 of the paint inlet 6 fixed in place.

The female coupler 8 and the male coupler 11 have a check valve structure that is opened when they are fitted to each other. Also,
Color change valve device 10 includes a plurality of color change valve CV ₁ ~CV ₃ for selectively supplying the respective colors of the conductive coating, the cleaning liquid supply valve CV _W for supplying washing air supply valve CV _A cleaning liquid supplying cleaning air It is provided.

Then, before the high voltage is not applied to the electrostatic coating machine 1, before the coating is started, the piston rod 13 of the air cylinder 12 is extended and the male coupler 11 of the coating material supply pipe 9 fixed to the piston rod 13 is extended. To the paint inlet 6 of the membrane pump 2.
By fitting the female coupler 8 provided in the above, the paint supply pipe 9 and the paint inlet 6 are connected to each other.

Next, the color change valve CV ₁ provided in the color change valve device 10
One of CV ₃ is opened, and the conductive paint of a desired color selected by the valve is supplied from the paint supply pipe 9 into the membrane pump 2 through the paint inlet 6, and at the same time,
The bag-shaped film body 5 is retracted by the drive device 3, and the conductive paint is introduced into the pump chamber of the membrane pump 2 made of the film body 5.

Then, when the membrane pump 2 is filled with a required amount of conductive paint necessary for painting of the electrostatic coater 1, the piston rod 13 of the air cylinder 12 is contracted to cause the piston rod 13 to contract.
The male coupler 11 of the paint supply pipe 9 fixed to is detached from the female coupler 8 of the paint inlet 6 and retracted to its original position.

In this state, a predetermined high voltage is applied to the electrostatic coating machine 1, the driving device 3 of the membrane pump 2 is activated, and the insulating shaft 4 of the driving device 3 is filled with the conductive paint to swell. By squeezing and displacing the bag-shaped film body 5, the conductive paint filled in the film body 5 is squeezed out from the paint discharge port 7 at a predetermined flow rate and supplied to the electrostatic coating machine 1 in a fixed amount. , Start electrostatic coating of conductive paint.

At this time, the membrane pump 2 that supplies the electro-conductive paint to the electrostatic coating machine 1 and the paint supply pipe 9 that supplies the electro-conductive paint into the film pump 2 are insulated from each other with a required distance maintained therebetween. The high voltage applied to the electrostatic coating machine 1 does not leak to the paint supply pipe 9 or the color changing valve device 10.

Therefore, the paint supply pipe 9 and the color change valve device
There is no need to insulate the entire paint supply system such as the paint tank or the paint pipe that supplies the conductive paint to the color change valves CV _{1 to} CV ₃ of the color change valve device 10 and the color change valve device 10.

Next, when the conductive paint filled in the membrane pump 2 is used up and the coating with the paint is completed, the application of high voltage to the electrostatic coating machine 1 is stopped, and the paint is provided at the tip of the paint supply pipe 9. The male coupler 11 is re-fitted to the female coupler 8 provided at the tip of the paint inlet 6, and the cleaning air supply valve CV _A and the cleaning liquid supply valve CV _W provided in the color changing valve device 10 are alternately opened and closed. The conductive paint remaining in the membrane pump 2 and the electrostatic coating machine 1 is washed and removed from the coating material supply pipe 9 by the cleaning air and the cleaning liquid supplied by these valves, and then discharged from the electrostatic coating machine 1.

At this time, since the piston or the like does not exist in the membrane pump 2, the conductive paint remaining inside can be washed and removed at high speed and thoroughly.

Then, when this cleaning is completed, the next color selected by the color change valves CV _{1 to} CV ₃ of the color change valve device 10 in the membrane pump 2 is moved backward while the film body 5 in the membrane pump 2 is retracted by the drive device 3. Introduce conductive paint that becomes paint.

Then, when the required amount of paint is filled in the membrane pump 2, after disconnecting the paint supply pipe 9 connected to the paint inlet 6, a high voltage is applied again to the electrostatic coating machine 1 to apply the next color paint. Start electrostatic coating of.

By doing so, the previous color paint remaining in the membrane pump 2 is quickly washed and the next color paint is filled in the membrane pump 2 rapidly, and the color change time in multicolor painting is greatly shortened. It is also possible to prevent coating failure due to color mixture of the previous color paint and the next color paint.

The cleaning air and the cleaning liquid for cleaning the inside of the membrane pump 2 are
Not only the case where the paint is supplied from the paint supply pipe 9, but the case where the paint is supplied through a dedicated pipe separately provided may be used.

Further, in FIG. 1, in order to install the membrane pump 2 in an electrically insulated state, the membrane body 5 of the membrane pump 2 is displaced by an insulating shaft 4 which is reciprocally moved by a driving device 3 such as a motor or an air cylinder. Although not limited to this, as shown in FIG. 2, the membrane body 5 of the membrane pump 2 is formed of a stretchable material such as latex and the conductive paint is introduced with the membrane body 5 sandwiched therebetween. The membrane body 5 may be displaced by introducing insulating oil into the membrane pump 2 on the side opposite to the side at a predetermined flow rate according to the coating material discharge amount of the electrostatic coating machine 1.

That is, the membrane pump 2 shown in FIG. 2 is provided with an insulating oil inflow / outlet port 14 on the side opposite to the side where the paint inflow port 6 and the paint discharge port 7 are provided with the film body 5 interposed therebetween. 14
The insulating oil supply pipe 16 made of an insulating material and the insulating oil discharge pipe 17 are connected to the
A flow meter 20 for detecting the flow rate of the insulating oil supplied from the insulating oil tank 18 by the gear pump 19 and adjusting the flow rate is interposed in the 16.

Then, when the paint supply pipe 9 is connected to the paint inlet 6 of the membrane pump 2 and the paint is introduced into the membrane pump 2, the switching valve 15 causes the insulating oil inflow / outlet port of the membrane pump 2.
14 is connected to the insulating oil discharge pipe 17 and is discharged from the inside of the membrane pump 2 to the insulating oil tank 18 in an amount corresponding to the amount of paint introduced.

When the membrane body 5 in the membrane pump 2 expands and the membrane pump is filled with a required amount of paint, the insulating oil inflow / outflow port 14
Is switched to the insulating oil supply pipe 16 side, and the insulating oil which is quantitatively supplied from the pipe 16 by the gear pump 19 is introduced into the membrane pump 2, and the film body 5 in the membrane pump 2 is displaced in the direction for pressing out the paint. Let

As a result, the membrane pump 2 can quantitatively supply the conductive coating material to the electrostatic coating machine 1 to which a high voltage is applied while keeping the electrically insulating state, and at the same time, the conductive coating material remaining inside the electrostatic coating machine 1 can be supplied. The washing can be performed at high speed without leaving any color.

[Effect of device]

As described above, according to the present invention, even when electrostatic coating is performed with a conductive paint such as a water-based paint, it is not necessary to take troublesome insulation measures in the paint supply system of the conductive paint. Even with a multicolor electrostatic coating apparatus having a color paint supply system, there is a very excellent effect that electrostatic coating can be performed with a non-polluting water-based coating without increasing equipment costs.

In addition, the color change time of the conductive paint in multicolor painting can be shortened and the color mixture of the previous color paint and the next color paint can be prevented, so that it is highly practical and can be used with an insulating resin paint that consumes a large amount of organic solvent. There is a usefulness that it is possible to promote the shift from the electric coating to the electrostatic coating with the water-based coating.

[Brief description of drawings]

1 and 2 are flow sheet diagrams showing an example of the electrostatic coating apparatus according to the present invention. Explanation of symbols 1 ... Electrostatic coating machine, 2 ... Membrane pump, 5 ... Membrane body, 6 ...
... Paint inlet, 7 ... Paint outlet, 8 ... Female coupler, 9 ... Paint supply pipe, 11 ... Male coupler.

Claims (1)

(57) [Scope of utility model registration request] Claim: What is claimed is: 1. An electrostatic coating device for a conductive paint, wherein a conductive paint is applied by an electrostatic coating machine (1) to which a high voltage is applied, having a paint inlet (6) and a paint discharge port (7). The pump chamber is formed of a bag-shaped film body (5) that can be filled with a required amount of conductive paint necessary for painting, and is filled with the conductive paint introduced from the paint inflow port (6) and bulged like a bag. Membrane (5)
The membrane pump (2), which squeezes and displaces the paint, presses the conductive paint from the paint discharge port (7) at a predetermined flow rate according to the paint discharge amount of the electrostatic coating machine (1). Installed in the state, the paint inlet (6)
The paint coating pipe (9) is detachably connected to the paint painting pipe (9).