JPS6033545B2 - Color change cleaning device for electrostatic coating machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a color change cleaning device for an electrostatic coating machine, which is equipped with a paint color change function that enables coating of multiple colors of paint with a single electrostatic coating layer.

Conventionally, an electrostatic coating machine equipped with a paint color changing function has a so-called color changing valve device installed in its paint supply system, and the paint supplied to the electrostatic coating machine through this color changing valve device. It has a cleaning device for cleaning. That is, during cleaning, a cleaning fluid such as air or thinner is supplied from the color change valve device to the electrostatic coating machine via the paint supply system to clean the electrostatic coating machine and the paint supply system. The cleaning fluid is also supplied to the paint passage formed inside the color change valve device,
This paint passage is also cleaned. The cleaning fluid supplied to the electrostatic sprayer is temporarily collected in a waste liquid collection container, and then sucked into a waste liquid absorption device via an electrically insulating scarlet liquor hose. The cleaning fluid that has cleaned the internal paint passages is sucked into the drainage suction device via an electrically insulated drainage hose. however,
If you perform color change cleaning after electrostatic painting with metallic paint using the conventional method described above, there will be residual metal in the drain hose, so the residual metal will be charged during the next electrostatic painting, and from outside The disadvantage is that discharge occurs due to the proximity of a ground object or the potential difference between metal particles.

Additionally, in this case, even if an electric discharge does not occur and a fire does not occur, the metal particles will cause a so-called bridging phenomenon, resulting in a short circuit between the high voltage section and the ground section, making electrostatic painting impossible. may also occur. Therefore, in order to eliminate this drawback, it is necessary to install the drain hose sufficiently away from the ground object, prevent the ground object from approaching from the outside, and ensure that the 9E liquid hose has sufficient withstand voltage. Although safety is maintained, such measures are often not possible due to problems such as installation space. Furthermore,
Regarding the discharge that occurs in the drain hose, under normal conditions where the suction air from the 9E liquid absorption device is sufficiently flowing into the drain hose, even if a discharge occurs, the concentration will reach the explosive limit. The risk is considered to be low as the possibility is considered to be low, but if a sufficient flow rate of the suction air cannot be obtained due to the scale liquid suction device being clogged or the suction air stopping, etc. It becomes extremely dangerous. The object of the present invention is to eliminate the various drawbacks of the conventional device described above, and to provide an electrostatic discharge device that can sufficiently wash and drain residual metal in the drain hose, and also shorten the cleaning time and, by extension, the color change time. An object of the present invention is to provide a color changing and cleaning device for a coating machine.

The present invention has an electrostatic coating machine that is supplied with paint during the painting process and a cleaning fluid during the color change cleaning process, and a pseudo-liquid that is positioned opposite the electrostatic coating machine during the color change cleaning process. a collection container, an electrically insulating drainage hose that conveys the interior of the drainage collection container and the 9E liquid suction device, and the BE
A flow path switching valve located near the pole of the liquid recovery container and interposed in the front drain hose, and a cleaning fluid that connects the cleaning fluid inlet of the flow path switching valve and the cleaning fluid supply source. A color changing cleaning device for an electrostatic coating machine is characterized by having a supply system and a valve device interposed in the system.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a first embodiment of the present invention, and FIGS. 2A to 2C sequentially illustrate the cleaning steps of this first embodiment.

In addition, in FIG. 1 and FIG. 2, A indicates the air valve and TH indicates the thinner valve, respectively. In FIGS. 1 and 2, an electrostatic coating machine 1 has a rotary atomizing head la rotated at high speed by an air motor (not shown), etc., and a high voltage is applied, thereby electrostatically atomizing the paint. It is used to paint an object (not shown).

A paint supply system 2 for supplying paint to the rotary atomizing head la has one end connected to the rotary atomizing head la and a pond end connected to the paint circulation 3. A color change valve device 4 and a paint regulator 5 are interposed in the paint supply system 2, and a plurality of paint circulations 3 are provided for each type of paint. On the other hand, the paint circulation 3 has a circulation 6 for cleaning fluid (e.g. air, thinner).
are arranged in parallel, and this circulation 6 is connected to a cleaning fluid inlet 8a of a valve device 8 via a line 7.
One cleaning fluid outlet 8b of this valve device 8 is connected to a cleaning fluid inlet 9a of a three-way valve 9 arranged in parallel with the color change valve device 4.
One cleaning fluid outlet (not shown) of the three-way valve 9 is connected to the paint supply system 2 via a color change valve device 4. The other cleaning fluid discharge valve 9b of the three-way valve 9 is connected to an electrically insulating drainage hose 11.
It is connected to the drainage suction device B via. The drain liquid collection container 12 is used as a rotating atomizing head l of the electrostatic coating machine 1 during color change cleaning.
A three-way valve 13 is arranged in parallel in the vicinity of the pole of this waste liquid collection container 12.

The cleaning fluid inlet 13a of the three-way valve 13 is connected to the cleaning fluid outlet 8c of the valve device 8 via the system 14, and the drain inlet row 3b of the three-way valve 13 is connected to the SE liquid recovery container 12. Further, the fluid discharge port 13c of the three-way valve 13 is connected to the scale liquid suction device B via an electrically insulating liquid drain hose 15. The operation of the color change cleaning device of the present invention having the above configuration is as follows. First, in order to paint the object to be coated with the electrostatic coating machine 1, after moving the 9E liquid collection container 12 to a position where it will not interfere with the painting process, the rotary atomizing head la
Apply high voltage and rotate.

Here, the color change valve device 4 is operated to cause the paint circulation 3 and the rotary atomizing head la to communicate with each other via the paint supply system 2, and the paint is supplied to the rotary atomizing head la to keep it static. Electric painting is performed. Next, the electrostatic coating machine 1 shown in FIG.
In order to paint with another color, follow the steps shown in Figure 2 A to C for cleaning.

The first cleaning step is shown in FIG. 2A.

That is, the valve device 8 is operated to allow the line 7 and the line 10 to pass through each other, the three-way valve 9 is actuated to allow the line 10 and the drain hose 11 to pass through each other, and furthermore, the drain absorber Activate B to start suction. Then, a cleaning fluid such as thinner or air flows into the drain hose 11 through the system line 7, valve device 8, system line 10, and three-way valve 9, and after cleaning the inside of the drain hose 11, the 8E liquid It flows into suction device B. The second cleaning step is shown in Figure 2.

In this cleaning process, the valve device 8, the three-way valve 9, and the color change valve device 4 are operated respectively to cause the system 7, the system 10, and the paint supply system 2 to move with respect to each other. The paint passage (not shown), the paint supply system 2, and the rotary atomization head la are cleaned. At the same time, 9E liquid collection container 12
to the position shown in the figure, operate the three-way valve 13 to connect the 9F liquid recovery container 12 and the 9E liquid hose 15, and further,
Activate the drainage suction device B. As a result, the drained liquid that has fallen and scattered from the rotating atomizing head la into the 9E liquid recovery container 12 is sucked into the drained liquid suction device B through the drain hose 15. The third cleaning step is shown in FIG. 2C.

In this cleaning process, the valve device 8 is operated to allow the line 7 and the line 14 to pass through each other, and the three-way valve 13 is actuated to allow the line 14 and the drain hose 15 to pass through each other. Activate the drainage suction device B. Then, the cleaning fluid becomes BE
The liquid flows into the liquid hose 15, washes the liquid drain hose 15, and is then sucked into the liquid liquid suction device B. In addition, the drain hose 15
It is possible to use a Teflon hose with a length of 3 [m] and an internal diameter of 4.6 [skin], and a cleaning thinner of 1500 [m].
cc/min] and air was 4 [k9/min], the time required for cleaning was 2 seconds.

FIG. 3 shows a second embodiment of the present invention, and in FIG.
Components with the same numbers as those in the figures indicate components with the same names that perform the same functions.

The feature of this embodiment is that the rotary atomizing head la of the electrostatic coating machine 1 and the paint circulation 3 are connected to the paint supply system 2, which is equipped with a cleaning air valve 4'a and a cleaning thinner valve. Color change valve 4 having 4'b
', and an on/off valve 4'' having a flow path switching function is installed in the paint supply system 2 between the color change valve 4' and the rotary atomizing head la.In this embodiment, , 8E To clean the liquid hose 15, the three-way valve 13 is operated to allow the line 14 to pass through the scale liquid hose 15, and at the same time, the valve device 8 is opened to allow the cleaning fluid to flow into the drain hose 15. What is necessary is to allow it to flow in. In addition, in the above second embodiment,
Of course, the air valve 4'a and the thinner valve 4'b are connected to an air supply source for cleaning and a thinner supply source for cleaning, respectively.

Further, in the first and second embodiments, the reference numeral 13 indicates a three-way valve, but this is not limited to a three-way valve, and it goes without saying that a three-way valve may also be used.

As explained above, according to the color change cleaning device of the present invention, the residual metal in the simulated liquid hose can be sufficiently cleaned and flowed down, so even when metallic paint is used, the ignition phenomenon due to electric discharge can be prevented. This can be reliably prevented, and since the cleaning path in each cleaning process is short, the cleaning time can also be shortened. Furthermore, since the three-way valve 13 is closed during painting, paint, scale liquid, etc. that have fallen into the drain liquid collection container 12 are collected by the drain hose 15.
Since it is reliably prevented from flowing down inside the 8E liquid hose, and the bridging phenomenon inside the 8E liquid hose is also reliably prevented, the situation where the high voltage part is shorted to the ground object and electrostatic painting becomes impossible is also prevented. can do.

[Brief explanation of drawings]

FIG. 1 is a front view showing a first embodiment of the present invention, FIGS. 2A to 2C are views showing a cleaning process, and FIG. 3 is a view showing a second embodiment of the present invention. 1... Electrostatic coating machine, 2... Paint supply system, 3... Paint circulation, 4... Color change valve device, 6... Circulation for cleaning fluid, 8... Valve device, 9
... Three-way valve, 11... Drainage hose, 12... Scale liquid collection container, 15... Drainage hose, B... 8E liquid suction device. Figure 1 Figure 2 Figure 2 Figure 3

Claims (1)

[Claims] 1. In the painting process, the paint is changed in color. In the cleaning process, the electrostatic coating machine is supplied with cleaning fluid, and the waste liquid collection container is located opposite to the electrostatic coating machine in the color change cleaning process. an electrically insulating drain hose that communicates between the inside of the liquid collection container and the drain absorption device; a flow path switching valve that is located very close to the drain recovery container and is interposed in the drain hose; It is characterized by having a cleaning fluid supply system that communicates the cleaning fluid inlet of the flow path switching valve with a cleaning fluid supply source, and a valve device interposed in the system, Color change cleaning device for electrostatic coating machines.