JPH06134359A - Coating material supply device - Google Patents

Abstract

PURPOSE:To decrease the consumption of a washing liquid by efficiently incorporating very small and uniform air bubbles into the washing liquid. CONSTITUTION:This coating material supply device is constituted by providing an air/liquid mixer 37 alternately disposed with plural right and left elements 39a, 39B within a casing 38 between a color change valve device 1 and a washing valve device 31 and simultaneously discharging air and thinner from the washing valve device 31 at the time of color change washing. As a result, the very small air bubbles are uniformly incorporated into the thinner by the air/ liquid mixture 37 at the time of the color change washing. The volume of the thinner occupying in flow passages, such as coating material passage of the color change valve device 1 and coating material pipe 9, is decreased by as much as the total volume-component of these air bubbles.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paint supply device for switching and supplying paints of a plurality of colors to a coating machine such as an electrostatic coating machine.

[0002]

2. Description of the Related Art FIG. 6 and FIG. 7 show a conventional paint supply device.

In the drawing, reference numeral 1 denotes a color change valve device, which is provided on a manifold 2 in which a paint passage (not shown) is formed, and on the most upstream side of the manifold 2. Gate valve 3 connected to a cleaning valve device 15 described later
And a plurality of paint valves 4A, 4B, ... 4M, 4N which are provided on the manifold 2 at the downstream side of the gate valve 3 and whose outlets are respectively connected to the paint passages (the "paint valve 4" as a whole). The pilot valve type spring return type 2 port 2 position switching valve is used as the gate valve 3 and the paint valve 4, and they are normally closed. Also, each paint valve 4A, 4
B, ... 4M and 4N are paint pipes 5A, 5B, ... 5 respectively.
It is connected to the A, B, ... M, N color paint tanks (neither is shown) via M and 5N.

Reference numeral 6 denotes a paint regulator provided on the most downstream side of the manifold 2, and the paint regulator 6 adjusts the valve opening degree in accordance with the control air pressure supplied from the control air pipe 7 to thereby paint. The pressure and the discharge amount are controlled.

Reference numeral 8 denotes a rotary atomizing type electrostatic coating machine. The coating machine 8 is provided with an atomizing head 8A located at the tip end side for atomizing the paint and at the base end side thereof. A plurality of external electrodes (not shown) are arranged on the outer circumference, spaced apart from each other in the circumferential direction. Then, the coating machine 8 atomizes the paint supplied through the trigger valve 10 and the like, which will be described later, by the atomizing head 8A, and electrically charges the particles of the paint by each external electrode, so that the ground potential is reached. It is for painting a coating material.

Reference numeral 9 denotes a paint pipe arranged in the painting machine 8, the tip side of the paint pipe 9 being connected to the atomizing head 8A of the painting machine 8 and the paint regulator 6 at the base end side thereof.
Is connected to the paint passage of the manifold 2 via.

10 is located inside the coating machine 8 and is a paint pipe 9
2 is a trigger valve provided on the downstream side of the paint valve and configured as a pilot air type two-port two-position switching valve. The trigger valve 10 opens and closes in response to pilot air, and The paint is supplied to the atomizing head 8A of the coating machine 8, and the paint is sprayed onto an external object (not shown) through the atomizing head 8A.

Reference numeral 11 denotes a drainage pipe, and the drainage pipe 1
One end of the No. 1 is located upstream of the trigger valve 10 and is provided in the middle of the paint pipe 9, and the other end is connected to a drainage tank 12 provided outside the painting machine 8.

Reference numeral 13 is provided in the middle of the drainage pipe 11,
1 shows a dump valve configured as a pilot air type spring return type 2 port 2 position switching valve, and the dump valve 13 is opened during cleaning so that the paint and thinner remaining in the paint pipe 9 can be drained. It is what is discharged inside.

Reference numeral 14 is a paint regulator 6 and a painting machine 8.
Is a gear type pump provided between the color change valve device 1 and the color change valve device 1.

Reference numeral 15 denotes a cleaning valve device provided on the upstream side of the manifold 2, and the cleaning valve device 15 is provided in the manifold 16 in which a common passage (not shown) is provided, and in the manifold 16. , An air valve 17 whose outlets are respectively connected to a common passage and a thinner valve 18 as a cleaning liquid valve, and the common passage of the manifold 16 is connected to the gate valve 3 of the color change valve device 1 via a connecting pipe 19. It is connected. In addition, the air valve 17, the thinner valve 18
Are connected to an air source and a thinner source (neither is shown) via an air pipe 20 and a thinner pipe 21, respectively.
The cleaning valve device 15 uses the air when switching the coating color.
By selectively discharging thinner, the manifold 2, the paint regulator 6, the paint pipe 9 and the like of the color change valve device 1 are cleaned.

The coating apparatus using the coating material supply apparatus according to the prior art has the above-mentioned structure. Next, the operation will be described with reference to FIG.

First, in order to spray the color A paint, a predetermined control air is supplied to the paint regulator 6 to open the valve. Next, when the A color paint valve 4A of the color change valve device 1 and the trigger valve 10 in the coating machine 8 are opened, the A color paint in the paint tank is the paint pipe 8A and the paint passage of the color change valve device 1. ,,
It is supplied to the coating machine 8 via the pump 14 and the coating pipe 9, and atomized by the atomizing head 8A of the coating machine 8. The atomized A-color paint particles are charged to a predetermined voltage by each external electrode, and fly and adhere to the external object to be coated along the lines of electric force.

During this time, the paint regulator 6
When the pressure in the paint pipe 9 becomes high, the valve opening is reduced to reduce the discharge amount, and conversely, when the pressure in the paint pipe 9 becomes low, the valve opening is decreased. Is increased to increase the discharge amount of the A-color paint, so that the pressure and discharge amount of the A-color paint are adjusted to the set values.

Next, in order to carry out cleaning after finishing the A color coating process, the A color paint valve 4A and the trigger valve 10 are closed, and the control air supplied to the paint regulator 6 is cut off. Let

Then, the gate valve 3 is opened to connect the cleaning valve device 15 and the color change valve device 1, and the dump valve 13
Is opened to secure the drainage flow path, the control air to the paint regulator 6 is increased to maximize the valve opening degree, and the air valve 17 of the cleaning valve device 15 is opened in this state. As a result, the air flowing from the air valve 17 into the paint passage of the manifold 2 via the common pipe of the manifold 16, the connecting pipe 19, and the gate valve 3 remains in the paint passage, the paint regulator 6, and the paint pipe 9. The A-colored paint is extruded and discharged from the dump valve 13 into the drainage tank 12 through the drainage pipe 11.

Next, by closing the air valve 17 and opening the thinner valve 18, the thinner supplied from the thinner valve 18 causes the paint passage of the color change valve device 1, the paint regulator 6, and the paint pipe 9 The A-color paint attached to the etc. is washed and discharged into the drainage tank 12 through the dump valve 13 and the drainage pipe 11. By repeating the supply of air and thinner a plurality of times, the interior of the paint pipe 9 and the like is cleaned.

On the other hand, during the above-mentioned cleaning process, the dump valve 13 is closed and the trigger valve 10 is opened, so that the air valve 17, the thinner valve 18 to the connecting pipe 19, the paint regulator 6, the paint pipe 9, etc. The air and thinner supplied selectively via the trigger valve 10 and the atomizing head 8
The atomizing head 8A while washing the color A paint remaining between the atomizing head 8A and
To the outside and wash the tip side of the coating machine 8. Also in the second cleaning step, it is preferable that cleaning is performed by alternately supplying air and thinner a plurality of times.

Next, after the paint passage of the color change valve device 1, the paint regulator 6, the paint pipe 9 and the like have been cleaned in this way, the B color paint valve 4B is opened to enter the paint pipe 9. Preparation for B color coating is performed by filling B color, opening the trigger valve 10 and discarding and spraying a part of the B color paint. And when the preparation for B color painting is completed,
As in the case of the A color coating described above, the B color is supplied to the coating pipe 9 and the B color coating is performed.

[0020]

By the way, in the above-described conventional coating material supply device, during the color change cleaning, the air is discharged from the cleaning valve device 15 which is separate from the color change valve device 1, so that the color change is performed. After the paint in the paint passage of the valve device 1 and the paint pipe 9 has been pushed out into the drainage tank 12, the paint adhered to the paint passage, the pipe wall of the paint pipe 9 and the inner wall is washed away by a thinner.

However, most of the paint clogging the paint passage of the color change valve device 1 and the paint pipe 9 is pushed out by the first air from the washing valve device 15, so the thinner supplied after the pushing out by this air. Has a problem that it only cleans a small amount of paint that has adhered to the paint passage, the paint pipe 9 and other pipe walls, and the consumption efficiency of thinner is low and the cleaning efficiency is reduced.

That is, after the extruding of the paint by air, the paint is only slightly attached to the paint passage, the pipe wall of the paint pipe 9, etc., and the thinner flowing through the paint passage and the paint pipe 9 Not all contribute to cleaning, and only the outer thinner, which is in slight contact with the pipe wall, performs cleaning. Therefore, most thinner is discharged into the drain tank 12 without cleaning. There is a problem that it is discharged and cleaning efficiency is low.

On the other hand, a small hole is formed in the middle of the cleaning liquid passage formed in the housing, and air is sent to the thinner in the cleaning liquid passage through the small hole to mix air bubbles in the thinner and cause turbulent flow. A coating apparatus equipped with a bubble mixing apparatus is known from Japanese Patent Application Laid-Open No. 62-132562. However, in this case, since the bubbles are mixed simply for the purpose of making the thinner flow turbulent, no consideration is given to making the bubbles smaller, uniform, etc. Since they cannot be mixed, bubbles having uneven sizes are unevenly distributed on the outside of the thinner, and there is a problem that the paint adhering to the pipe wall cannot be reliably washed. Further, in this case, since the air bubble mixing device is provided between the thinner source and the thinner valve, a pipeline or an on-off valve connecting the air bubble mixing device and the air source is required, and the entire structure is significantly complicated. The problem is that

The present invention has been made in view of the above-mentioned problems of the prior art, and provides a paint supply device capable of efficiently mixing fine and uniform bubbles into a cleaning liquid and reducing the amount of the cleaning liquid used. The purpose is to do.

[0025]

In order to solve the above-mentioned problems, the structure adopted by the present invention is a color change valve device having a plurality of paint valves, the outflow side of which is connected to a painting machine, and the color change device. In a paint supply device provided on the inflow side of the valve device and including a cleaning valve device including a cleaning liquid valve and an air valve, a tubular casing is provided between the color change valve device and the cleaning valve device, A plurality of gas-liquid mixers, which are arranged in the axial direction of the casing and are formed by twisting a plate, are provided, and the cleaning liquid and the air are simultaneously discharged from the cleaning valve device at the time of cleaning. is there.

[0026]

When the cleaning valve device discharges the cleaning liquid and the air into the gas-liquid mixer at the same time during the color change cleaning, the cleaning liquid and the air are divided by a plurality of elements while flowing through the casing of the gas-liquid mixer. , Stirred, and bubbles are mixed in the cleaning liquid.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS. In the embodiment, the same components as those of the prior art shown in FIGS. 6 and 7 described above are designated by the same reference numerals, and the description thereof will be omitted.

First, FIGS. 1 to 4 relate to a first embodiment of the present invention, in which 31 is a cleaning valve device applied to this embodiment in place of the cleaning valve device 15 described in the prior art. Shows,
The cleaning valve device 31 is the cleaning valve device 15 described in the related art.
Almost the same as the above, as shown in FIG.
And a manifold 32 in which the manifold 32 is formed.
Of the air valve 33 and the thinner valve 34, which are provided to face each other and have their outlets connected to the common passage 32A, respectively.
5, the air source and the thinner source (neither is shown) are respectively connected via the thinner pipe 36. However, the cleaning valve device 31 according to the present embodiment is connected to the gate valve 3 of the color change valve device 1 via a gas-liquid mixer 37, which will be described later, and discharges air and thinner simultaneously during color change cleaning. Different from the technology.

Reference numeral 37 denotes a gas-liquid mixer provided by connecting between the cleaning valve device 31 and the color change valve device 1. The gas-liquid mixer 37 is a long cylinder as shown in FIG. Formed from a casing 38 having flanges 38A and 38A formed at both ends, and a total of six left elements 39A and right elements 39B arranged alternately in the axial direction of the casing 38. The casing 38 is configured as a mixing stirrer, the inflow side of which is connected to the common passage 32A of the manifold 32 through one flange portion 38A, and the outflow side of which is the flow of the gate valve 3 through the other flange portion 38A. It is connected to the entrance 3A. Each of the elements 39A and 39B is formed by twisting a plate body such as an iron plate to the left and right by 180 degrees, and the left element 39A and the right element 39B are arranged so as to be offset from each other by 90 degrees. Further, the gas-liquid mixer 37 has the cleaning valve device 3 at the time of color change cleaning.
By dividing the air and thinner flows that simultaneously flow in from 1 according to the number of elements 39A, 39B, fine air bubbles are mixed into the thinner.

The paint supply device according to the present embodiment has the above-mentioned structure, and its basic operation is not different from that of the prior art. Therefore, the operation during color change cleaning, which is a feature of this embodiment, will be described with reference to FIGS. 3 and 4.

First, when the coating of the color A is completed, the trigger valve 10 is closed, the dump valve 13 is opened, the gate valve 3 is opened, and the cleaning valve device 31 and the color changing valve device 1 are opened.
And are connected via a gas-liquid mixer 37.

Next, when air is discharged from the air valve 33 of the cleaning valve device 31 into the common passage 32A of the manifold 32, this air passes through the gas-liquid mixer 37 and the gate valve 3 and the paint of the color change valve device 1 is discharged. The A-color paint, which has flowed into the passage and is in the paint passage, the paint regulator 6, the paint pipe 9 and the like, is pushed out into the external drain tank 12 and discharged.

Next, when the thinner valve 34 is opened intermittently while the air valve 33 is still open, the air from the air valve 33 and the thinner from the thinner valve 34 together form a common passage of the manifold 32. Each element 3 flows into the gas-liquid mixer 37 via 32A and flows through the gas-liquid mixer 37.
By being divided and stirred by 9A and 39B, minute bubbles a are mixed in the thinner to form a gas-liquid mixed fluid.
Then, as shown in FIG. 4, the gas-liquid mixed fluid flows into the drainage tank 12 while cleaning the paint P adhering to the paint passage of the color change valve device 1, the pipe wall of the paint pipe 9, and the like. The interior of the paint pipe 9 and the like is cleaned by repeating the cleaning with the gas-liquid mixed fluid a plurality of times. Further, the tip side of the coating machine 8 is also washed with a gas-liquid mixed fluid of air and thinner.

Note that, as shown in FIG. 3, the filling of B color and the like are not different from those of the prior art, and therefore the description thereof will be omitted.

Thus, according to this embodiment, between the color change valve device 1 and the washing valve device 31, the left side inside the casing 38,
Since the gas-liquid mixer 37 in which the right elements 39A and 39B are alternately arranged is provided, and the air and thinner are simultaneously discharged from the cleaning valve device 31 at the time of color change cleaning,
The gas-liquid mixer 37 can uniformly mix the minute bubbles a into the thinner.

As a result, as shown in FIG. 4, only the total volume of the bubbles a uniformly mixed in the thinner Th occupy the thinner Th in the paint passage of the color change valve device 1 or the paint pipe 9 or the like. It is possible to reliably reduce the capacity, the amount of thinner required for cleaning is significantly reduced, the cleaning efficiency is improved, and the cleaning cost can be effectively reduced.

Further, since the minute bubbles a can be uniformly mixed in the thinner Th by the gas-liquid mixer 37, uneven cleaning caused by uneven distribution of uneven bubbles outside the thinner Th can be prevented. The paint P adhering to the paint passage of the color change valve device 1 and the pipe wall such as the paint pipe 9 can be effectively washed, the reliability and the like can be greatly improved, and the superposition due to the rupture of the bubbles a and the like. The sonic effect allows the paint P adhering to the pipe wall to be crushed and easily melted, and the cleaning effect can be greatly enhanced.

Further, in this embodiment, since the gas-liquid mixer 37 is provided between the color change valve device 1 and the cleaning valve device 31, as in the prior art disclosed in JP-A-62-132562. , No need for a conduit or an on-off valve for supplying air to the bubble mixing device provided on the upstream side of the thinner valve,
The entire structure can be simplified and compactly formed.

Next, FIG. 5 shows a second embodiment of the present invention. The feature of this embodiment is that an injector is provided on the inflow side of the gas-liquid mixer, and a thinner from a thinner valve is inserted through the injector. This is because air is mixed and the mixture of thinner and air is divided and stirred by a gas-liquid mixer.
In this embodiment, the same components as those in the first embodiment described above are designated by the same reference numerals, and the description thereof will be omitted.

In the figure, reference numeral 41 denotes a cleaning valve device according to this embodiment, and the cleaning valve device 41 is substantially the same as the cleaning valve device 31 described in the first embodiment, and a manifold 4 to be described later.
2, an air valve 43, and a thinner valve 44, and is connected to the gate valve 3 of the color change valve device 1 via the gas-liquid mixer 37. However, the cleaning valve device 41 according to this embodiment is different from that according to the first embodiment in that an injector 45 described later is provided in the manifold 42.

Reference numeral 42 denotes a manifold which is flange-connected to the inflow side of the gas-liquid mixer 37 and has a common passage 42A formed therein. The manifold 42 has a gas-liquid mixer 37.
The air valve 43 is provided in the upstream opening facing the common passage 42A.
A thinner valve 44 is vertically connected to the common passage 42A on the downstream side of the air valve 43.

Reference numeral 45 denotes an injector provided in the manifold 42, and the injector 45 is the common passage 4
An air nozzle 45A fitted on the most upstream side of 2A and configured to squeeze and eject the air from the air valve 43, and the air nozzle 45.
A throat 45B that is fitted to the most downstream side of the common passage 42A so as to face A and that circulates the mixture of thinner and air to the gas-liquid mixer 37 side while squeezing the mixture.

Thus, in this embodiment having such a configuration, it is possible to obtain substantially the same operational effects as those of the first embodiment described above.

In each of the above embodiments, the cleaning valve device 3 is used.
1 and 41 and the color change valve device 1 are separately formed, and both are connected by the gas-liquid mixer 37, but the present invention is not limited to this, and for example, a single manifold having a common passage. A cleaning valve device including an air valve and a thinner valve is provided on the most upstream side of the above, and a color changing valve device including a plurality of paint valves is provided downstream of the cleaning valve device to integrally form a paint mixing device. Alternatively, in this case, a gas-liquid mixer may be provided between the washing valve device and the color change valve device and in the middle of the common passage.

Further, in each of the above-mentioned embodiments, the case of cleaning with thinner was described as an example, but in the case of the water-based paint, water can be used as the cleaning liquid.

Further, in each of the above embodiments, the thinner valve 34 is intermittently opened and closed while the air valve 33 is kept open, so that the gas-liquid mixer 37 generates the gas-liquid mixed fluid. As mentioned above, instead of this, the air valve 3
After the valve 3 is opened, the thinner valve 34 may be opened after a predetermined time has elapsed, and the valves 33 and 34 may be continuously opened to perform cleaning with the gas-liquid mixed fluid.

On the other hand, in each of the above embodiments, the gas-liquid mixer 37
The left and right elements 39A and 39B have been described as being alternately arranged in threes therein, but instead of this, one, two, or four or more left and right elements are alternately arranged. You may arrange.

Further, in each of the above-mentioned embodiments, the case where the invention is applied to the coating apparatus equipped with the rotary atomizing type electrostatic coating machine has been described as an example. However, the liquid pressure atomizing type coating machine and the air atomizing type are used. It can be widely applied to other painting machines such as painting machines.

[0049]

As described in detail above, according to the present invention, a cylindrical casing is provided between the color change valve device and the cleaning valve device,
A plurality of elements are arranged in the axial direction of the casing, and a gas-liquid mixer including an element formed by twisting a plate is provided, and the cleaning liquid and the air are simultaneously discharged from the cleaning valve device at the time of cleaning. When the cleaning valve device discharges the cleaning liquid and air to the gas-liquid mixer at the same time during color change cleaning, the flow of the cleaning liquid and air is divided and agitated by multiple elements while flowing in the casing, and the minute amount is contained in the cleaning liquid. Air bubbles are mixed uniformly.

As a result, the volume of the cleaning liquid occupying in the flow passage such as the paint passage of the color change valve device can be reliably reduced by the total volume of the air bubbles uniformly mixed in the cleaning liquid, which is necessary for the cleaning. It is possible to reduce the amount of cleaning liquid, improve cleaning efficiency, and effectively reduce cleaning cost.

Further, it is possible to effectively prevent uneven cleaning caused by uneven distribution of non-uniform bubbles on the outside of the cleaning liquid, and to clean the paint adhered to the pipe wall such as the paint passage of the color change valve device. The reliability and the like can be improved, and the paint adhering to the tube wall can be easily melted while being pulverized by the ultrasonic effect due to the bursting of air bubbles and the like, and the cleaning effect can be enhanced.

Further, since the gas-liquid mixer is provided between the color change valve device and the cleaning valve device, as described in the prior art, the air bubble mixing device provided on the upstream side of the cleaning liquid valve is filled with air. It is possible to simplify the entire structure and to make it compact in size by eliminating the need for a pipeline or an on-off valve for supplying.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing a paint supply device according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing an enlarged main part in FIG.

FIG. 3 is a time chart showing an operating state of the paint supply device.

FIG. 4 is an explanatory diagram showing a state of thinner in which bubbles are mixed by a gas-liquid mixer.

FIG. 5 is a cross-sectional view showing an enlarged main part of a paint supply device according to a second embodiment of the present invention.

FIG. 6 is an overall configuration diagram showing a conventional paint supply device.

FIG. 7 is a time chart showing an operating state of a conventional paint supply device.

[Explanation of symbols]

 1 Color change valve device 4 Paint valve 8 Coating machine 31,41 Washing valve device 33,43 Air valve 34,44 Thinner valve (washing liquid valve) 37 Gas-liquid mixer 38 Casing 39A Left element 39B Right element a Bubble Th thinner

Claims (1)

[Claims] 1. A color change valve device comprising a plurality of paint valves, the outflow side of which is connected to a coating machine, and a wash valve device provided on the inflow side of the color change valve device, the wash valve device comprising a wash liquid valve and an air valve. In a coating material supply device provided with, between the color change valve device and the cleaning valve device, a tubular casing, and a plurality of elements arranged in the axial direction of the casing and formed by twisting a plate body, A paint supply device characterized by comprising a gas-liquid mixer consisting of (3) and discharging the cleaning liquid and air from the cleaning valve device at the same time during cleaning.