JPH09122543A - Rotary atomizing head type electrostatic coating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten washing time of a coating material passage to improve workability and to reduce the used quantity of solvent by installing a metallic coating material passage independently of the other coating material passages. SOLUTION: A feed tube 10 is made to have triplex tube construction consisting of an inner periphery side tube 11, an intermediate tube 12 and an outer periphery side tube 13, and flow passages formed by them are so formed as a solid coating material passage 14, a metallic coating material passage 15 and a thinner passage 16 from inside in this order, which are independent on each other. Metallic piping 19 connected to the metallic coating material passage 15 is made as a spiral piping. Therefore, the occurrence of bridge formation phenomenon in the metallic coating material is prevented by the spiral metallic piping 19, and also, since the solid coating material passage 14 and the metallic coating material passage 15 are independent on each other, aluminum powder remaining in the metallic coating material passage 15 is prevented from being mixed in the solid coating material to easily finish the washing of the metallic coating material passage 15 and the like.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary atomizing head type electrostatic coating machine suitable for coating an object to be coated such as a car body.

[0002]

2. Description of the Related Art Generally, as a coating machine for coating an object to be coated such as a car body of an automobile, a rotary atomizing head type electrostatic coating machine is widely used from the viewpoint of coating efficiency and the like. The head type electrostatic coating machine includes a coating machine main body, an air motor provided in the coating machine main body, a rotary shaft which is inserted in an axial direction of the air motor and is rotated by the air motor, and an outside of the coating machine main body. A rotary atomizing head located on the tip side of the rotary shaft, and a feed tube extending axially in the rotary shaft, the tip side extending into the rotary atomizing head; The feed tube is generally composed of a high-voltage generator that charges the paint supplied to the rotary atomizing head to a high voltage, and the feed tube is directed toward the rotary atomizing head toward the paint or the feed tube tip or the rotary atomizing head. Solvent for cleaning adhered paint Discharge, and supplies, and is connected to the color changing valve apparatus and the solvent supply source or the like via a pipe or the like.

Further, the coating machine selectively discharges two kinds of coatings having different properties (inclusion, viscosity, etc.) such as metallic coating containing aluminum powder and solid coating from one coating machine. There are things that came to paint,
For example, it is disclosed in Japanese Utility Model Publication No. 4-106660.

Here, in the coating machine disclosed in Japanese Utility Model Laid-Open No. 4-106660, there are provided two systems of paint supply pipes for supplying paint to a paint nozzle serving as a paint discharge port, and one of them has a spiral shape. The spiral pipe is wound and the other is straight pipe. In addition, solid paint with high viscosity flows through straight pipes with low flow resistance, and metallic paint with low viscosity and aluminum powder contains spiral pipes with long pipe length to prevent bridge phenomenon when charged to high voltage. It is supposed to be distributed.

[0005]

By the way, in the above-mentioned prior art, the two paint supply pipes are joined to one paint nozzle, and the paint nozzle is shared by the metallic paint and the solid paint. For this reason, when cleaning the previous color paint to change the color from metallic paint to solid paint, it is necessary to carefully wash the solid paint so that aluminum powder does not enter the solid paint. However, there is a problem that the amount of thinner used increases.

Further, when the aluminum powder contained in the metallic paint adheres to and remains on the inner peripheral wall of the pipe or the like, when the solid paint is applied, the remaining aluminum powder is mixed with the solid paint to the object to be coated. There is a problem that spraying may occur, resulting in poor coating and degrading coating quality.

The present invention has been made in view of the above-mentioned problems of the prior art. By providing the metallic paint passage independently of the other paint passages, the washing time of the paint passage is shortened and the workability is improved. An object is to provide a rotary atomizing head type electrostatic coating machine capable of reducing the amount of solvent used.

[0008]

A rotary atomizing head type electrostatic coating machine according to the present invention includes a coating machine main body, an air motor provided in the coating machine main body, and an air motor inserted in the axial direction of the air motor. A rotating shaft rotated by an air motor,
A rotary atomizing head located outside the main body of the coating machine and provided on the tip side of the rotary shaft, and an axially extending portion inside the rotary shaft, the tip side extending into the rotary atomizing head. And a high voltage generator for charging the paint supplied to the rotary atomizing head to a high voltage.

Then, in order to solve the above-mentioned problem,
A feature of the configuration adopted by the invention of claim 1 is that the feed tube has a triple tube structure from an inner peripheral side tube, an intermediate tube and an outer peripheral side tube arranged substantially coaxially, and the inner peripheral side of each of the tubes. The inside of the tube serves as a first paint passage, the interior paint tube and the intermediate tube serve as a second paint passage, and the intermediate tube and the outer circumference tube serve as a solvent passage for cleaning the tip, Further, one of the first and second paint passages is used as a metallic paint passage, and the metallic paint passage is connected to a metallic paint supply source side through a spiral pipe wound in a spiral shape. It is configured to do.

With this configuration, the metallic paint is discharged and supplied from the metallic paint passage to the rotary atomizing head while flowing through the spiral pipe, and the charged paint particles charged to a high voltage from the rotary atomizing head. Is sprayed onto the object to be coated. Further, because other paint, for example, solid paint, is discharged and supplied toward the rotary atomizing head from another paint passage provided independently of the metallic paint passage,
Even if the aluminum powder remains in the metallic paint passage, it will not be mixed into other paints such as solid paint. This makes it possible to easily clean the metallic paint passage and spiral piping.

According to a second aspect of the present invention, a check valve for elastically opening and closing the opening of the solvent passage is provided at the tip of the outer peripheral tube to prevent the solvent in the solvent passage from dripping. It is provided.

With this configuration, the solvent can be prevented from dripping from the solvent passage except during cleaning, so that the occurrence of coating failure due to the solvent dripping can be prevented.

According to a third aspect of the present invention, the spiral pipe is provided behind the air motor so as to wind around the outer periphery of the other paint passage and the solvent passage, and is provided in the main body of the coating machine. Therefore, the spiral pipe can be compactly arranged in the main body of the coating machine.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION A rotary atomizing head type electrostatic coating apparatus using a rotary atomizing head type electrostatic coating machine according to an embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

First, FIGS. 1 to 4 show a first embodiment of the present invention, and 1 shows a rotary atomizing head type electrostatic coating machine (hereinafter referred to as electrostatic coating machine 1) according to the present embodiment. Electrostatic coating machine 1
Is a front housing 2, a rear housing 3, which will be described later.
Air motor 7, rotary atomizing head 9, feed tube 10,
Solid piping 18, metallic piping 19, check valve 2
1. The high voltage generator 22 is generally configured.

Reference numeral 2 denotes a front housing which constitutes the main body of the coating machine, and the front housing 2 has a tubular portion 2A and a bottom portion 2.
It is formed in a bottomed cylindrical shape that opens from B and forward. An air motor 7 is mounted in the cylindrical portion 2A, and communication holes 17A, 17 to be described later are provided in the center of the bottom portion 2B.
B and 17C are formed.

Reference numeral 3 is a rear housing provided behind the front housing 2, and the rear housing 3 is a tubular portion 3.
It is formed in a bottomed cylindrical shape that opens forward from A and the bottom portion 3B, and a pipe connection space 4 is formed inside the cylindrical portion 3A.
Further, an insulation support 5 for attaching the electrostatic coating machine 1 to a reciprocator or an arm (not shown) of a painting robot is fixed to the bottom portion 3B. Further, the rear housing 3 is covered by the cover 6 on the outer peripheral side together with the front housing 2 described above.

Reference numeral 7 indicates a turbine type air motor provided in the front housing 2, 8 indicates a hollow rotary shaft inserted in the axial direction of the air motor 7, and the rotary shaft 8
A feed tube 10, which will be described later, is inserted therein. The air motor 7 is supplied with compressed air from the outside to rotate the rotary atomizing head 9 described later together with the rotary shaft 8 at a high speed.

Reference numeral 9 denotes a bell-shaped rotary atomizing head attached to the tip of the rotary shaft 8. A high voltage is applied to the rotary atomizing head 9 by a high voltage generator 22 via the rotary shaft 8 and the like. It is supposed to be done. When the paint is discharged from the feed tube 10 in a state where the rotary atomizing head 9 is rotated at a high speed by the air motor 7, the paint is sprayed as a liquid thread toward the object to be coated while charging the paint to a high voltage. Is.

Reference numeral 10 denotes a feed tube provided in the rotary shaft 8 so as to extend in the axial direction. The feed tube has a base end side attached to the bottom portion 2B of the front housing 2 and a front end side protruding from the rotary shaft 8. It extends into the rotary atomizing head 9.

Here, as shown in FIGS. 2 and 3, the feed tube 10 has a small diameter inner peripheral side tube 11 and a medium diameter inner peripheral side tube 11 arranged substantially coaxially so as to cover the inner peripheral side tube 11. The intermediate tube 12 and a large-diameter outer peripheral tube 13 arranged substantially coaxially so as to cover the intermediate tube 12.
It has a triple tube structure. In addition, a solid paint passage 14 through which the solid paint that forms the first paint passage flows is formed inside the inner tube 11 and a metallic paint path that forms a second paint passage is formed between the inner tube 11 and the intermediate tube 12. An annular metallic paint passage 15 through which the paint flows, and an annular thinner through which a thinner (solvent) for washing the paint adhering to the rotary atomizing head 9 and the like flows between the intermediate tube 12 and the outer peripheral tube 13 Passage 1
It is 6.

Reference numerals 17A, 17B and 17C are communication passages formed in the center of the bottom portion 2B of the front housing 2. The communication passages 17A, 17B and 17C are solid paint passages 14, metallic paint passages 15, thinner passages 16 and solid pipes. 18, the metallic pipe 19, and the thinner pipe 20 are communicated with each other.

Reference numeral 18 is a solid pipe located in the pipe connection space 4 and connected to the solid paint passage 14 via a communication passage 17A, and 19 is connected to the metallic paint passage 15 via a communication passage 17B. Metallic piping provided, 20 is a thinner piping provided in communication with the thinner passage 16 through the communication passage 17C, respectively, the solid pipe 18 is formed as a straight straight pipe,
As a result, the resistance during distribution is reduced, and the solid paint having high viscosity can be smoothly distributed. The metallic pipe 19 is formed as a long spiral pipe in which the outer circumferences of the solid pipe 18 and the thinner pipe 20 are spirally wound along the inner peripheral wall of the pipe connection space 4.
This prevents the bridging phenomenon of aluminum powder that occurs when the metallic paint is charged to a high voltage by lengthening the pipe length.

Reference numeral 21 denotes a check valve which is provided at the tip of the outer peripheral tube 13 of the feed tube 10 and which is made of a rubber material having elasticity. The check valve 21 always has its tip at the outer circumference of the intermediate tube 12 by its elastic force. When the thinner is supplied from a thinner supply source 29, which will be described later, the supply pressure at this time is received so that the tip is separated from the intermediate tube 12. And open the thinner passage 16
It is designed to discharge thinner from.

Reference numeral 22 denotes a high voltage generator built in the outer peripheral side of the front housing 2, and the high voltage generator 22
The input side of is connected to an external power source via the high voltage cable 22A, and the output side is connected to the air motor 7 via an electrode plate (neither is shown). Then, the high voltage generator 22 converts the voltage supplied from the external power source into a predetermined high voltage, supplies the high voltage from the air motor 7 to the rotary atomizing head 9 via the rotary shaft 8, and the rotary fog is generated. The paint sprayed from the chemical head 9 is directly charged to a high voltage.

Reference numeral 23 denotes a solid paint supply valve located on the outer peripheral side of the rear housing 3 and connected to the solid pipe 18. The solid paint supply valve 23 is a 2-port 2-position valve as shown in FIG. Formed as a solenoid on-off valve of
When the valve is closed, the supply of the solid paint to the solid paint passage 14 side is stopped and the valve is opened to open the solid paint passage 1.
Solid paint is supplied to the 4 side.

Reference numeral 24 denotes a metallic paint supply valve which is located on the outer peripheral side of the rear housing 3 and is connected to the metallic pipe 19. The metallic paint supply valve 24 is formed as a 2-port 2-position electromagnetic on-off valve. In the closed state, the supply of the metallic paint to the metallic paint passage 15 side is stopped, and the valve is opened to supply the metallic paint to the metallic paint passage 15 side.

Reference numeral 25 denotes a manifold for branching and distributing the paint between the solid paint supply valve 23 side and the metallic paint supply valve 24 side, and the manifold 25 is a paint supply pipe 2
Manifold 31 of switching valve mechanism 30 described later via 6
It is connected to the.

27 is located on the outer peripheral side of the rear housing 3 like the paint supply valves 23 and 24 described above, and the thinner pipe 2
0 shows a thinner supply valve which is connected to 0, and the thinner supply valve 27 is formed as a 2-port / 2-position electromagnetic opening / closing valve, and is connected to a thinner supply source 29 through a thinner supply pipe 28. The thinner supply valve 27 supplies the thinner supplied from the thinner supply source 29 to the thinner passage 16 side by opening the thinner supply valve 27.

Reference numeral 30 denotes a switching valve mechanism connected to the electrostatic coating machine 1 via a paint supply pipe 26. The switching valve mechanism 30
Is composed of a manifold 31, a paint switching valve 32, a thinner valve 36, an air valve 37, etc., which will be described later.

Reference numeral 31 is a manifold connected to the paint supply pipe 26, and 32 is a paint switching valve attached to the manifold 31. The paint switching valve 32 is formed as a 3-port 2-position electromagnetic switching valve. The inflow side is connected to a color change valve device 40 described later via a paint pipe 33,
The outflow side is connected to a waste liquid tank 35 via a flow path (not shown) in the manifold 31 and a drain pipe 34. The paint switching valve 32 switches the paint or the like supplied from the paint pipe 33 between the manifold 31 side and the waste liquid tank 35 side.

Reference numeral 36 denotes a thinner valve attached to the manifold 31, and 37 denotes an air valve attached to the manifold 31, respectively. The thinner valve 36 and the air valve 37 are formed as electromagnetic opening / closing valves of two ports and two positions. . Further, the thinner valve 36 is connected to the thinner supply source 29, and the air valve 37
Is connected to the air supply source 38.

Reference numeral 39 denotes a flashable gear pump provided in the middle of the paint pipe 33. The flashable gear pump 39 supplies the paint supplied from the color changing valve device 40 to the electrostatic coating machine 1 side at a predetermined flow rate. Is. Also,
The flashable gear pump 39 has a thinner valve that opens and closes a thinner passage for washing each gear and shaft, and a bypass passage that opens and closes a bypass passage that bypasses the thinner supplied during color change washing for each gear. And a valve (neither shown).

Reference numeral 40 denotes a color change valve device, and the color change valve device 4
0 is a manifold 41 and paint valves 42A, ... 42N and 42a, ... 42 attached to the manifold 41.
n, a thinner valve 43 for cleaning and an air valve 44 attached to the most upstream portion of the manifold 41, and an air operated paint attached to the most downstream portion of the manifold 41 to keep the pressure of the paint constant. It is composed of a regulator 45 (hereinafter, referred to as AOPR45). Also, the paint valves 42A, ... 42N and 42a ,.
, 42N are connected to paint supply lines 46A, ... 46N of solid paints of A color, ... N color, and paint valves 42a, ... 42n are paints of metallic paint of a color, ... 46n are connected to the supply lines 46a. Further, the thinner valve 43 is used for the thinner supply source 29.
In addition, the air valves 44 are connected to the air supply sources 38, respectively.

The rotary atomizing head type electrostatic coating apparatus according to this embodiment has the above-mentioned construction, and its operation will be described below.

First, the case of applying the metallic paint of color a will be described.

First, the paint valve 42a of the color changing valve device 40 is opened, and the paint switching valve 32 of the switching valve mechanism 30 is connected to the paint pipe 33 and the manifold 31 in order to form the supply passage of the metallic paint of color a. While switching to communicate with
The metallic paint supply valve 24 of the electrostatic coating machine 1 is opened.

Next, in the state of each valve described above, compressed air is supplied to the air motor 7 to rotate the rotary shaft 8, and the rotary atomizing head 9 attached to the tip of the rotary shaft 8 is rotated at high speed. , Drives the flashable gear pump 39. As a result, the metallic paint of color a is applied to the paint supply line 46a.
From the AOPR 45 at a constant pressure while flowing into the flow path in the manifold 41 from the paint valve 42a.
A constant flow rate is supplied from the flashable gear pump 39 toward the switching valve mechanism 30.

The a-color metallic paint supplied from the flashable gear pump 39 toward the switching valve mechanism 30 flows into the flow path in the manifold 31 through the paint switching valve 32, and the paint is supplied from the flow path. It is supplied to the manifold 25 side via a pipe 26.

Further, the a-color metallic paint flowing from the paint supply pipe 26 into the manifold 25 flows to the side of the metallic paint supply valve 24 which is in an open state, and the metallic paint supply valve 24 allows the metallic pipe 19 to flow through the metallic pipe 19. It is distributed and supplied to the metallic paint passage 15, and is discharged and supplied from the metallic paint passage 15 toward the rotary atomizing head 9.

As a result, the discharge is directed toward the rotary atomizing head 9,
The supplied a-color metallic paint becomes charged paint particles charged to a high voltage by the high voltage generator 22 in the rotary atomizing head 9, and is sprayed as a liquid thread from the rotary atomizing head 9,
It flies along the lines of electric force formed between itself and the object to be coated, and it is applied to the object to be coated.

Here, the metallic paint causes a bridging phenomenon due to the aluminum powder when it is charged to a high voltage, but in the present embodiment, the metallic piping 19 is a long spiral piping so that the bridging phenomenon at this time is eliminated. It prevents the occurrence.

Next, a case of cleaning the a-color metallic paint remaining and adhering to each part when changing the color of the a-color metallic paint to the other-color paint will be described.

First, the paint valve 42a is closed, the paint switching valve 32 is switched to connect the paint pipe 33 and the drainage pipe 34, and the bypass valve of the flushable gear pump 39 is opened to connect the bypass passage. Let In this state, the air valve 44 is opened to allow compressed air from the air supply source 38 to flow through the manifold 41, the AOPR 45,
The paint pipe 33, the paint switching valve 32, and the drainage pipe 34 are circulated, and the a-color metallic paint remaining in these pipe lines is extruded.

At this time, the air valve 37 of the switching valve mechanism 30 is opened to allow compressed air from the air supply source 38 to flow through the manifold 31 and the paint supply pipe 2.
6, the metallic paint supply valve 24, the metallic pipe 19, the metallic paint passage 15 are circulated through the manifold 25, and the a-color metallic paint remaining in these pipes is extruded.

When the extrusion of the metallic paint of color a is completed, the thinner valve 43 is opened and the thinner supply source 29
By the thinner from the flow path in the manifold 41, AO
PR45, paint pipe 33, paint switching valve 32, drainage pipe 3
The paint adhered to the inner wall of 4 is washed. At the same time, the thinner valve 36 is opened, and the thinner from the thinner supply source 29 causes the passage in the manifold 31, the paint supply pipe 26, the passage in the manifold 25, the metallic paint supply valve 24, and the metallic pipe 19 to flow. , Metallic paint passage 1
The paint attached to the inner wall of 5 is washed.

Here, from the manifold 31 of the switching valve mechanism 30 described above to the metallic paint passage 15 of the electrostatic coating machine 1.
Since the metallic paint passage 15 is provided separately from the solid paint passage 14 during the cleaning up to, the remaining aluminum powder does not mix with the solid paint which is the next color paint, and the metallic paint supply valve 24 The metallic pipe 19 and the metallic paint passage 15 need only be simply cleaned.

Further, at the time of this cleaning, the thinner supply valve 2
By opening 7 and supplying thinner from the thinner supply source 29 to the thinner passage 16 through the thinner pipe 20,
The check valve 21 is opened by the pressure when the thinner is supplied, and the thinner is discharged toward the rotary atomizing head 9. As a result, the metallic paint of a color attached to the tip of the rotary atomizing head 9 and the feed tube 10 is cleaned.

When the cleaning of each cleaning part is completed,
Thinner valves 43, 36, thinner supply valve 27 and air valve 4
4, 37 are closed. At this time, since the thinner supply valve 27 is closed, the thinner supply pressure to the thinner passage 16 side disappears. Therefore, the check valve 21 is brought into close contact with the outer peripheral surface of the intermediate tube 12 by its elastic force, and the thinner drips from the thinner passage 16. Prevent falling.

Next, the case of applying the A color solid paint will be described.

First, the paint valve 42A of the color changing valve device 40 is opened, and the paint switching valve 32 of the switching valve mechanism 30 is connected to the paint pipe 33 and the manifold 31 in order to form a supply channel for the A color solid paint. While switching to communicate with
The metallic paint supply valve 24 of the electrostatic coating machine 1 is closed and the solid paint supply valve 23 is opened.

Next, in the above valve operating state, the flash atomizing pump 39 is rotated while the rotary atomizing head 9 is rotated at a high speed.
Drive. As a result, the solid paint of A color flows from the paint supply line 46A into the flow path in the manifold 41 via the paint valve 42A, and is discharged from the AOPR 45 at a constant pressure while being switched from the flashable gear pump 39 to the switching valve mechanism 30. Is supplied at a constant flow rate toward.

The A-color solid paint supplied from the flashable gear pump 39 toward the switching valve mechanism 30 flows into the flow path in the manifold 31 via the paint switching valve 32 and passes through the paint supply pipe 26. Manifold 2
It is supplied to the 5 side.

Further, the A-color solid paint flowing from the paint supply pipe 26 into the manifold 25 flows to the solid paint supply valve 23 side which is in an open state, and the solid paint supply valve 23 connects the solid pipe 18 to the solid paint supply valve 23. It is circulated and supplied to the solid paint passage 14, and is discharged and supplied from the solid paint passage 14 toward the rotary atomizing head 9.

As a result, the discharge is directed toward the rotary atomizing head 9,
The supplied A color solid paint is sprayed as charged paint particles from the rotary atomizing head 9 and applied to the object to be coated.

Although the solid paint has a higher viscosity than the metallic paint, the solid pipe 18 is a straight pipe and is linearly formed to the solid paint passage 14 to reduce the flow resistance to reduce the flow resistance. To ensure smooth distribution.

Thus, according to this embodiment, the feed tube 10 has a triple tube structure from the inner peripheral side tube 11, the intermediate tube 12 and the outer peripheral side tube 13 so that the inside of the inner peripheral side tube 11 is solid-coated. A passage 14 is formed, and the inner tube 11 and the intermediate tube 1 are provided.
2 is a metallic paint passage 15, and a space between the intermediate tube 12 and the outer peripheral side tube 13 is a thinner passage 16
In addition, the solid pipe 18 connected to the solid paint passage 14 is a straight pipe, and the metallic pipe 19 connected to the metallic paint passage 15 is a spiral spiral pipe. Therefore, when a solid paint having high viscosity is applied, the paint can be smoothly distributed by the solid pipe 18 formed in a straight shape, and even if the metallic paint is charged to a high voltage, the spirally wound metallic pipe 19 is used. Therefore, it is possible to prevent the bridge phenomenon from occurring.

Moreover, in this embodiment, since the solid paint passage 14 and the metallic paint passage 15 are independently provided, even when the metallic paint is changed to the solid paint, the remaining aluminum powder is solid. It is possible to prevent the mixture from being mixed in the paint, improve the finish of the solid paint, and improve the reliability of the electrostatic coating machine 1. In particular, the painting machine is attached to the tip of the arm of a painting robot, etc., and it is desired to make it smaller. Inevitably, the paint passage is formed in a complicated and complicated state. Although it is difficult to remove the aluminum powder, the aluminum powder according to this embodiment can surely solve this problem.

Further, since it is possible to prevent aluminum powder from being mixed in the solid paint, the metallic paint supply valve 2
4. The cleaning of the metallic pipe 19 and the metallic paint passage 15 can be easily performed, and the cleaning time can be shortened to improve workability and reduce the amount of thinner used.

Further, since the metallic pipe 19 is provided in the pipe connection space 4 so as to wind around the outer periphery of the solid pipe 18 and the thinner pipe 20, the respective pipes 18, 19, 20 are efficiently arranged in the pipe connection space 4. The electrostatic coating machine 1 can be arranged well, and the electrostatic coating machine 1 can be downsized.

Next, FIG. 5 shows a second embodiment of the present invention. The feature of this embodiment is that the solid paint supply path and the metallic paint supply path are completely independent of each other. is there. In this embodiment, the same components as those in the above-described first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In the figure, reference numeral 51 is a rotary atomizing head type electrostatic coating machine according to the present embodiment (hereinafter referred to as electrostatic coating machine 51), and 52 is located on the rear side of the electrostatic coating machine 51. A supply valve unit provided separately from the coating machine 51 is shown. The supply valve unit 52 is composed of a solenoid opening / closing valve with two ports and two positions, and a solid paint supply valve 53 connected to the solid pipe 18 and a metallic pipe 19 are connected. It is composed of a metallic paint supply valve 54 connected thereto and a thinner supply valve 55 connected to the thinner pipe 20, and the thinner supply valve 55 is connected to a thinner supply source 29.

Reference numeral 56 denotes a solid paint supply means for supplying solid paint to the solid paint passage 14, and the solid paint supply means 56 is a paint supply pipe 57.
Switching valve mechanism 58 connected to the solid coating material supply valve 53 via a solid paint supply valve 53, a flashable gear pump 60 provided in the middle of the coating material pipe 59 for quantitatively supplying the coating material to the switching valve mechanism 58, and a and b colors. The color changing valve device 61 for selectively supplying solid paints of m colors and n colors. The structure of the switching valve mechanism 58 is composed of a paint switching valve, a thinner valve, an air valve, and the like, and there is no difference from the switching valve mechanism 30 described in the first embodiment, so the description thereof is omitted.

Here, the color changing valve device 61 is similar to the color changing valve device 40 described in the first embodiment in that the manifold 6 is used.
2 and a paint valve 63 attached to the manifold 62
a, 63b, ... 63m, 63n, a thinner valve 64 for cleaning, which is attached to the most upstream part of the manifold 62, an air valve 65, and the most downstream part of the manifold 62, to keep the pressure of the paint constant. Although it is composed of the air operated paint regulator 66,
The color change valve device 61 according to the present embodiment includes the paint valve 63a,
63b, ... 63m, 63n are all a color, b color, ... m
Color, n-color solid paint supply lines 67a, 67b, ...
The difference is that they are connected to 67m and 67n.

On the other hand, reference numeral 68 denotes a metallic paint supply means for supplying metallic paint to the metallic paint passage 15, and the metallic paint supply means 68 is connected to the metallic paint supply valve 54 via a paint supply pipe 69. Switching valve mechanism 70, a flashable gear pump 72 provided in the middle of a paint pipe 71 for quantitatively supplying paint to the switching valve mechanism 70, and metallic paints of A color, B color, ... M color, N color And a color changing valve device 73 for selectively supplying C. The configuration of the switching valve mechanism 70 is also composed of a paint switching valve, a thinner valve, an air valve, etc., and since there is no difference from the switching valve mechanism 30 described in the first embodiment, description thereof will be omitted.

Here, the color changing valve device 73 is the same as the color changing valve device 40 described in the first embodiment.
4 and a paint valve 75 attached to the manifold 74
A, 75B, ... 75M, 75N, a thinner valve 76 for cleaning and an air valve 77 attached to the most upstream portion of the manifold 74, and the most downstream portion of the manifold 74 to keep the pressure of the paint constant. Although it is composed of the air operated paint regulator 78,
The color change valve device 73 according to the present embodiment includes the paint valve 75A,
75B, ... 75M, 75N are all A color, B color, ... M
Color, N color metallic paint supply lines 79A, 79B,
The difference is that they are connected to 79M and 79N.

In this way, in this embodiment having the above-mentioned structure, it is possible to obtain substantially the same function and effect as in the first embodiment described above. Since the solid paint supplying means 56 for supplying the paint and the metallic paint supplying means 68 for supplying the metallic paint to the metallic paint passage 15 are completely independent from each other, it is possible to prevent the aluminum powder of the metallic paint from mixing with the solid paint. In addition to more reliable prevention and improvement in coating quality, the cleaning time of the metallic paint can be greatly shortened, and workability can be further improved and thinner consumption can be reduced.

Further, in the present embodiment, the supply valve unit 5 comprising the solid paint supply valve 53, the metallic paint supply valve 54 and the thinner supply valve 55 on the rear side of the electrostatic coating machine 51.
Since 2 is provided separately from the electrostatic coating machine 51, maintenance and design changes of the supply valves 53, 54, 55 can be easily performed.

In the first embodiment, the solid paint supply valve 23, the metallic paint supply valve 24 and the thinner supply valve 27 are integrally provided with the electrostatic coating machine 1. However, the solid paint supply valve, the metallic paint valve The paint supply valve and the thinner supply valve may be provided separately from the electrostatic coating machine. Further, also in the second embodiment, the solid paint supply valve, the metallic paint supply valve and the thinner supply valve may be provided integrally with the electrostatic coating machine.

In each of the above embodiments, the solid paint passage 14 is provided as the first paint passage in the inner peripheral side tube 11, and the solid paint passage 14 is provided as the second paint passage between the inner peripheral side tube 11 and the intermediate tube 12. Although the metallic paint passage 15 is provided, the metallic paint passage may be formed inside the inner tube 11 and the solid paint passage may be formed between the inner tube 11 and the intermediate tube 12.

Further, in each of the above-described embodiments, the case where the metallic pipe 19 as the spiral pipe is arranged on the downstream side of the metallic paint supply valves 24 and 54 is illustrated, but the metallic pipe is arranged on the upstream side of the metallic paint supply valve. It may be arranged in the.

[0072]

As described above in detail, according to the first aspect of the invention, the feed tube has the triple tube structure from the inner peripheral side tube, the intermediate tube and the outer peripheral side tube. , A second paint passage and a solvent passage are formed, and among the first and second paint passages,
Since either one is configured as a metallic paint passage that is connected to the metallic paint supply source side through a spiral pipe, when applying metallic paint,
The spiral pipe prevents the bridging phenomenon by the aluminum powder, and the metallic paint charged with high voltage can be sprayed from the rotary atomizing head toward the object to be coated. Further, since the metallic paint passage is provided independently of other paint passages, even if aluminum powder remains in the metallic paint passage, it will not be mixed into the solid paint, and therefore,
Coating quality can be improved by preventing coating defects due to the mixing of aluminum powder. Moreover, since the metallic paint passage and the spiral pipe can be easily cleaned, the cleaning work time can be shortened and the workability can be improved, and the amount of thinner used during cleaning can be reduced.

According to the second aspect of the present invention, by providing the check valve for elastically opening and closing the opening of the solvent passage at the tip of the outer peripheral side tube, the check valve is used to remove the solvent from the inside of the solvent passage except when cleaning. Since it is possible to prevent the solvent from dripping, it is possible to prevent the occurrence of coating defects due to the solvent dripping, and it is possible to improve the reliability of the rotary atomizing head type electrostatic coating machine.

According to the third aspect of the present invention, the spiral pipe is arranged behind the air motor so as to wind around the outer periphery of the other paint passage and the solvent passage. It can be compactly arranged in the main body of the coating machine, and the electrostatic coating machine can be downsized.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a rotary atomizing head type electrostatic coating machine according to a first embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view showing a portion A shown in FIG.

FIG. 3 is a cross-sectional view of a rotary shaft and a feed tube viewed from the direction of arrows III-III in FIG.

FIG. 4 is a circuit configuration diagram showing an overall configuration of a coating apparatus using the rotary atomizing head type electrostatic coating machine in FIG.

FIG. 5 is a circuit configuration diagram showing an overall configuration of a rotary atomizing head type electrostatic coating device according to a second embodiment of the present invention.

[Explanation of symbols] 1 rotary atomizing head type electrostatic coating machine 2 front housing (coating machine main body) 7 air motor 8 rotating shaft 9 rotary atomizing head 10 feed tube 11 inner peripheral side tube 12 intermediate tube 13 outer peripheral side tube 14 solid Paint passage (first paint passage) 15 Metallic paint passage (second paint passage) 16 Thinner passage (solvent passage) 19 Metallic piping (spiral piping) 21 Check valve 22 High voltage generator

Claims (3)

[Claims] 1. A coating machine body, an air motor provided in the coating machine body, and an axial direction of the air motor,
A rotary shaft that is rotated by the air motor, a rotary atomizing head that is located outside the coating machine main body and is provided on the tip side of the rotary shaft, and a tip that is provided by axially extending inside the rotary shaft. In a rotary atomizing head type electrostatic coating machine comprising a feed tube whose side extends into the rotary atomizing head and a high voltage generator for charging the paint supplied to the rotary atomizing head to a high voltage, The feed tube has a triple tube structure composed of an inner peripheral side tube, an intermediate tube and an outer peripheral side tube arranged substantially coaxially, and the inside peripheral side tube of each of the tubes serves as a first paint passage, and A second paint passage is provided between the peripheral tube and the intermediate tube,
A solvent passage for cleaning the tip is provided between the intermediate tube and the outer peripheral side tube, and one of the first and second paint passages is a metallic paint passage, and the metallic paint passage is a spiral. A rotary atomizing head type electrostatic coating machine, characterized in that it is connected to the metallic paint supply source side via a spiral pipe wound in a spiral shape. 2. A check valve for elastically opening and closing the opening of the solvent passage in order to prevent the solvent in the solvent passage from dripping down at the tip of the outer peripheral tube. The rotary atomizing head type electrostatic coating machine described in 1. 3. The spiral pipe is arranged behind the air motor so as to wind around the outer periphery of the other paint passage and the solvent passage, and is provided on the main body of the coating machine. Rotary atomizing head type electrostatic coating machine.