JP2786940B2 - Electrostatic coating equipment for conductive paint - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic coating apparatus for applying a conductive paint such as a water-based paint, a slurry paint, and a metallic paint by an electrostatic paint machine to which a high voltage is applied. .

[Conventional technology]

When applying a conductive paint such as a water-based paint with an electrostatic coating machine to which a high voltage is applied, insulate the paint supply type of the coating machine to prevent leakage of the high voltage applied to the electrostatic coating machine. It is necessary to take countermeasures (Japanese Patent Laid-Open No. 55-114366)
No. 56-141869), a multi-color electrostatic coating apparatus for automotive painting, in which dozens of colors of paint are changed and painted.
There is a trouble that the paint supply pipe, the paint tank and the like must be insulated for each paint of each color.

For this reason, in automotive painting, electrostatic painting with an insulating resin paint 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 paint is forgotten.

However, recently, global environmental protection movements have been growing,
The use of organic solvents that generate pollutants such as hydrocarbons has also been called for in the coatings industry.

[Problems to be solved by the invention]

Therefore, in order to recommend coating with a water-based paint, the present invention has taken troublesome insulation measures in a paint supply system such as a paint supply pipe and a paint tank even when performing electrostatic coating with a conductive paint such as a water-based paint. The main technical problem is to eliminate the necessity, and it is also a technical problem to shorten the color change time when performing multi-color coating with a conductive paint.

[Means for solving the problem]

In order to solve these problems, the present invention relates to a conductive paint electrostatic coating apparatus for coating a conductive paint with an electrostatic coater to which a high voltage is applied, a paint inlet, and a paint inlet. A plurality of pumps having a paint discharge port from which a required amount of the introduced conductive paint is pressed out at a predetermined flow rate according to the paint discharge amount of the electrostatic coating machine are installed in an electrically insulated state. Each paint supply pipe connected to each color change valve device having a washing air supply valve and a washing liquid supply valve is detachably connected to the paint inlet of the pump, and the paint discharge port of each pump is connected. An outlet is connected to each switching valve for switching the paint discharge port between an outflow path on the electrostatic coating machine side and an outflow path on the drain tank side, and the outlet tank is connected to the outflow path on the drain tank side. The drainage pipes connected to the Characterized in that it is made to so that.

[Action]

According to the present invention, while no high voltage is applied to the electrostatic coating machine, a paint supply pipe is connected to each paint inlet of each pump, and the conductive paint is supplied into each pump through the paint supply pipe. Introduce.

When the required amount of the conductive paint required for painting is filled in one pump, the paint supply pipe is separated from the paint inlet of each pump.

In addition, the drainage pipe is also separated from the outflow passage on the drainage tank side of each switching valve to which the paint discharge port of each pump is connected.

As a result, the pump is disconnected from the paint supply pipe and the drain pipe, and is maintained in an electrically insulated state.

In this state, while applying a predetermined high voltage to the electrostatic coating machine, the paint discharge port of the pump filled with the required amount of conductive paint is connected to the outlet of the electrostatic coating machine by a switching valve, The conductive paint that is pressed out from the paint discharge port at a predetermined flow rate is supplied to the electrostatic coating machine.

At this time, each paint supply pipe is separated from the paint inlet of each pump, and each drain pipe is also separated from the outlet passage on the drain tank side of each switching valve to which the paint discharge port of each pump is connected. Since it is isolated from the electrostatic coating machine, the high voltage applied to the electrostatic coating machine does not leak to the paint supply system and the drainage system of the conductive paint through each pump.

Therefore, it is not necessary to take troublesome insulation measures for the whole paint supply system and drainage system.

In addition, when the coating is completed by one pump, the next coating can be started immediately by another pump after cleaning the electrostatic coating machine, and the pump that has completed the coating during the cleaning of the electrostatic coating machine. And the paint can be filled in the pump in advance.

Therefore, the interval from the end of the coating to the start of the next coating can be shortened, and in the multicolor electrostatic coating apparatus, the color change time of the coating is reduced.

〔Example〕

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

FIG. 1 is a flow sheet diagram showing an example of the electrostatic coating apparatus according to the present invention, and FIG. 2 is a time chart showing the operation thereof.

In this example, three pumps 2 for alternately supplying a constant amount of conductive paint to an electrostatic coating machine 1 to which a high voltage of 80 to 120 KV is applied.
A, 2B and 2C are installed in an electrically insulated state by well-known insulating means such as an insulator (not shown).

Each of the pumps 2A, 2B, and 2C has a predetermined flow rate corresponding to a paint inlet 3 and a required amount of conductive paint introduced into the cylinder 4 from the paint inlet 3 according to the paint discharge amount of the electrostatic coating machine 1. And a paint discharge port 5 which is pressed out.

The conductive paint introduced into the cylinder 4 is pressed out from the paint discharge port 5 by a piston 8 attached to the tip of an insulating shaft 7 that is reciprocated by a driving device 6 such as a motor or a cylinder. .

Then, for the paint inlet 3 of each pump 2A, 2B, 2C,
Each paint supply pipe connected to each color change valve device 9A, 9B, 9C
10 are detachably connected.

That is, a female coupler 11 is provided at each paint inlet 3 and a male coupler 12 is provided at each paint supply pipe 10, and the male coupler 12 is fixed to a piston rod 14 of an air cylinder 13, Each of the paint supply pipes 10 is detachably connected to the paint inlet 3 of each of the pumps 2A to 2C by engaging and disengaging with the female coupler 11 by expansion and contraction of the piston rod 14.

The female coupler 11 and the male coupler 12 have a check valve structure that is opened when they are fitted to each other.

Further, Kakuirokawa valve device 9A~9C, a plurality of color change valve CV ₁ -C supplying each color of the conductive coating of the same color to each other
And V _3, are provided with a flushing air supply valve CV _A and the cleaning liquid supply valve CV _W supplying high-pressure cleaning air and the high-pressure washing liquid.

Next, the paint discharge port 5 of each of the pumps 2A, 2B, and 2C is provided with a switching valve that switches the paint discharge port 5 to an outflow path 15 on the electrostatic coating machine 1 side and an outflow path 17 on the drain tank 16 side. 18A, 18B, and 18C, respectively.

Further, the outflow passage 15 on the side of the electrostatic coating machine 1 is provided with each switching valve 18.
The manifold is provided with a low pressure cleaning air supply valve 19 and a low pressure cleaning liquid supply valve 20 attached thereto.

Further, a female coupler 21 is provided in the outflow path 17 of each of the switching valves 18A to 18C on the drain tank 16 side, and a male coupler 23 is provided in each drain pipe 22 connected to the drain tank 16. Then, the male coupler 23 is fixed to the piston rod 25 of the air cylinder 24, and is fitted to the female coupler 21 in a detachable manner by the expansion and contraction of the piston rod 25, so that each of the switching valves 18A to 18C is The outflow passage 17 on the drain tank 16 side is detachably connected to each drain pipe 22.

The low-pressure cleaning air supply valve 19 is connected to the insulating pipe 26.
And is directly connected to a low-pressure air supply source 27.

Further, the low-pressure cleaning liquid supply valve 20 is provided at the tip of a pipe 29 for supplying a cleaning liquid from a low-pressure cleaning liquid supply source 28 and is removably fitted with a male coupler 32 which is advanced and retracted by a piston rod 31 of an air cylinder 30. A female coupler 33 is provided, and the cleaning liquid pipe 29 is detachably connected.

The above is the configuration of the electrostatic coating apparatus shown in FIG. 1, and the following operation will be described.

When conducting the electrostatic coating by supplying conductive paint of a desired color alternately from the pumps 2A to 2C to the electrostatic coating machine 1 in order,
For example, when the coating by the pump 2A is completed and the application of the high voltage to the electrostatic coating machine 1 is stopped, the male coupler provided in the pipe 29 of the low-pressure cleaning liquid supply source 28 changes from the state shown in FIG.
32 is connected to the low-pressure cleaning liquid supply valve 20 by the air cylinder 30.
Low pressure cleaning air supply valve
Open and close alternately 19 and low pressure cleaning solution supply valve 20
Electrostatic coating machine 1 from outlet channel 15 provided with 2A switching valve 18A
The remaining paint is washed away from the electrostatic coating machine 1 with low-pressure cleaning air and a low-pressure cleaning liquid.

At the same time, the color change valve device is connected to the female coupler 11 provided at the paint inlet 3 of the pump 2A after painting.
A male coupler 12 provided at the end of a paint supply pipe 10 connected to 9A is fitted with an air syringe 13 and an outflow passage on the drain tank 16 side of a switching valve 18A connecting the paint discharge port 5 of the pump 2A. In the female coupler 21 provided in 17,
The male coupler 23 provided at the end of the drain pipe 22 connected to the drain tank 16 is fitted with an air cylinder 24, and the cleaning air supply valve CV _A and the cleaning liquid supply valve CV _W of the color changing valve device 9A are connected. The paint is alternately opened and closed, and the paint remaining from the color changing valve device 9A to the pump 2A and the switching valve 18A is washed and removed with high-pressure washing air and high-pressure washing liquid and discharged to the drainage tank 16.

Next, when the washing is completed, the paint supply pipe 10 is disconnected from the paint inlet 3 of the pump 2A, and the switching valve 18 is disconnected.
The drainage pipe 22 is disconnected from the outflow passage 17 on the drainage tank 16 side of A, and the pipe 29 for supplying the low-pressure cleaning liquid is also disconnected from the low-pressure cleaning liquid supply valve 20, and the state is returned to the state shown in FIG.

Then, a high voltage is again applied to the electrostatic coating machine 1 and a pump is applied.
The switching valve 18C to which the paint discharge port 5 of 2C is connected is opened, the paint discharge port 5 is connected to the outflow passage 15 on the side of the electrostatic coating machine 1, and the conductive material pre-filled in the cylinder 4 of the pump 2C. The conductive paint is pressed out from the paint discharge port 5 by the piston 8 and is supplied in a constant amount to the electrostatic coating machine 1 to start the next coating.

In this way, the high voltage applied to the electrostatic coating machine 1 is applied to each of the paint supply pipes 10 and the drain pipes via the pumps 2A to 2C.
Since there is no risk at all leaking to 22, an insulating protection throughout the paint supply system that supplies respective colors of conductive paint on a number of color change valve CV ₁ ~CV ₃ provided in Kakuirokawa valve device 9A~9C There is no trouble to give.

When the coating by the pump 2C is completed, the application of the high voltage to the electrostatic coating machine 1 is stopped, and the switching valve connecting the paint discharge port 5 of the pump 2C according to the same procedure as described above.
The paint remaining from the outflow path 15 of the 18C electrostatic coating machine 1 to the electrostatic coating machine 1 is cleaned and removed with the low-pressure cleaning air and the low-pressure cleaning liquid alternately supplied from the low-pressure cleaning air supply valve 19 and the low-pressure cleaning liquid supply valve 20. The high-pressure cleaning air and high-pressure cleaning liquid supplied alternately from the cleaning air supply valve CV _A and the cleaning liquid supply valve CV _W of the color changing valve apparatus 9C are used to remove the remaining paint from the color changing valve device 9C to the pump 2C and the switching valve 18C. Wash and remove with.

Moreover, while this cleaning is being performed, in a pump 2A already cleaning has been completed, the desired color of the conductive coating material is selected in the color change valve CV ₁ ~CV ₃ provided in the color change valve device 9A Fill.

As a result, the pump 2A is ready to start painting at any time when the cleaning of the pump 2C is completed. As compared with the case where a new coating is started, the interval from the end of the coating to the restart of the coating is shortened by the filling time of the coating.

In addition, when the capacity of the cylinders 4 of the pumps 2A to 2C is large and it takes time to clean the inside thereof, as shown in FIG.
The interval between the end of painting and the start of the next painting can be completed by using three occasions when painting by each pump is finished and when painting by the other two pumps is finished respectively. Need not be long.

That is, the painting by the pump 2A is completed and the electrostatic painting machine 1
When the application of the high voltage to is stopped, while the electrostatic coating machine 1 is being cleaned with the low-pressure cleaning air and the low-pressure cleaning liquid alternately supplied from the low-pressure cleaning air supply valve 19 and the low-pressure cleaning liquid supply valve 20. Only, the inside of the pump 2A is cleaned with the high-pressure cleaning air and the high-pressure cleaning liquid supplied from the cleaning air supply valve CV _A and the cleaning liquid supply valve CV _{W of} the color changing valve device 9A. Even if the cleaning in 2A has not been completed, the cleaning is interrupted.

Then, when the application of the high voltage to the electrostatic coating machine 1 is stopped after the coating of the next pump 2C is completed, the color change is performed only while the electrostatic coating machine 1 is being cleaned. Valve device 9A
The inside of the pump 2A is washed again with the high-voltage washing air and the high-pressure washing liquid supplied from the washing air supply valve CV _A and the washing liquid supply valve CV _W , and the washing is completed.

Then, when the coating of the next pump 2B is completed and the application of the high voltage to the electrostatic coating machine 1 is stopped and the cleaning of the electrostatic coating machine 1 is started, the cleaning is completed until the cleaning is completed. , it is filled to the color change valve device 9A of color change valve CV ₁ ~CV ₃ selected desired color of the conductive pump 2A the paint washing was terminated.

By doing so, it is possible to shorten the color change time in the multi-color coating and increase the coating productivity.

〔The invention's effect〕

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

In addition, it has an excellent effect that the interval from the end of painting to the start of the next painting can be shortened, and the color change time in multicolor painting can be shortened. There is usefulness that it is possible to promote the transition from the electrostatic coating with a water-soluble coating to the electrostatic coating with a water-soluble coating.

[Brief description of the drawings]

FIG. 1 is a flow sheet diagram showing an example of the electrostatic coating apparatus according to the present invention, and FIG. 2 is a time chart showing the operation thereof. DESCRIPTION OF SYMBOLS 1 ... Electrostatic coating machine, 2A, 2B, 2C ... Pump, 3 ... Paint inlet, 5 ... Paint discharge port, 9A, 9B, 9C ... Color change valve device, CV _A ... Cleaning air supply valve, CV _W … Cleaning liquid supply valve, 10… Paint supply piping, 11… Female coupler, 12… Male coupler, 13… Air cylinder, 15… Outflow on the electrostatic coating machine side , Drain tank, 17 ... Outflow path on drain tank side, 18A, 18B, 18C ... Switching valve, 21 ... Female coupler, 22 ... Drain piping, 23 ... Male coupler , 24 …… Air cylinder.

Claims (1)

(57) [Claims] 1. A paint inlet (3) and a paint inlet (3) for a conductive paint electrostatic coating apparatus for coating a conductive paint with an electrostatic paint machine (1) to which a high voltage is applied. A plurality of pumps (2A) having a paint discharge port (5) from which a required amount of conductive paint introduced from the nozzle is pressed out at a predetermined flow rate in accordance with the paint discharge amount of the electrostatic coating machine (1); 2B), (2C)
Are installed in an electrically insulated state, and the respective pumps (2A),
Color change valve devices (9A), (9B) each having a cleaning air supply valve (CV _A ) and a cleaning liquid supply valve (CV _W ) for the paint inlet (3) of (2B) and (2C). , (9C), the paint supply pipes (10) connected to each other are detachably connected, and the paint discharge ports (5) of the pumps (2A), (2B), (2C) are connected to the paint supply pipes (10). Each switching valve (18A), (18B), which connects the discharge port (5) to the outflow path (15) on the electrostatic coating machine (1) side and the outflow path (17) on the drainage tank (16) side.
(18C), and each drainage pipe (22) connected to the drainage tank (16) is detachably connected to the outflow channel (17) on the drainage tank (16) side. An electrostatic coating apparatus for a conductive paint, characterized in that: