JP2003284976A - Coating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating apparatus in which a remaining coating material between a forwarding limit of a piston and a coating gun can be efficiently washed. <P>SOLUTION: A valve unit 17 is provided between a coating material inlet 112 of the coating gun 11 and an apex of a coating material pipeline 12. The valve unit comprises a coating material path 172 in which one end is communicated with the coating material inlet of the coating gun and the other end is communicated with the coating material pipeline, a first washing fluid path 177 communicated with the coating material path, a waste liquid path 181 communicated with the coating material path, a first valve 176 for opening and closing the coating material path communicated with the coating material inlet of the coating gun, a second valve 180 for opening and closing the first washing fluid path, and a third valve 184 for opening and closing the waste liquid path. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a coating apparatus,
Particularly, the present invention relates to a coating apparatus suitable for applying a high voltage to a conductive coating such as a water-based coating.

[0002]

2. Description of the Related Art Water-based paints are excellent in terms of preventing fire accidents because they do not contain organic solvents, so that waste liquid treatment is easy and environmentally friendly, and that they do not contain dangerous substances such as organic solvents. Therefore, instead of or together with the organic solvent-based paint, there is an increasing need for an intermediate coating or a top coating.

When electrostatically applying a high voltage to such a water-based paint, unlike an organic solvent-based paint, an external application method or an electrical insulation mechanism of a paint circuit (hereinafter referred to as a voltage block method) is adopted. Need (for example,
See Japanese Patent No. 2790153).

[0004]

The external application method is a method in which a voltage is applied from an external electrode to the paint particles atomized and sprayed by a coating machine to charge the particles, and the particles are contact charged in the paint circuit. Since electricity does not occur, electricity rarely flows through the paint.

However, the external application method has a problem that the coating efficiency is inferior to that of the voltage block method and the amount of coating used increases by about 10%. Further, in principle, the coating gun is easily soiled, and as a result, defects of the coating material are likely to occur. Therefore, it is necessary to increase the frequency of cleaning the coating gun, which is a factor that reduces productivity.

On the other hand, as a conventional voltage block system, there is a relay paint tank insulation system in which the relay paint tank installed on the booth side is floated by an insulating stand so that the range from the coating machine to the relay paint tank is in the charging range. Are known.

However, when the number of coating colors is large, a large space is required on the booth side, and there is a problem that workability is poor when the color is changed frequently or when the amount of paint used is large.

Therefore, a piston is provided in a paint hose that guides the paint to the coating gun, and the paint is supplied to the front of the piston and moved forward to supply the paint to the coating gun and to fill the rear of the piston. It has been proposed to insulate the applied voltage before and after the piston with air (see Japanese Patent Application Laid-Open No. 2001-327897).

By the way, in this coating apparatus, since paint remains structurally between the advance limit of the piston and the coating gun, it is necessary to clean it. However, the piston is retracted to fill the cleaning liquid. Then, there was a problem that it took a long time to change colors.

[0010]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a coating apparatus capable of efficiently cleaning the residual paint between the advance limit of the piston and the coating gun.

(1) In order to achieve the above object, according to the present invention, a coating gun to which a voltage is applied, a paint pipe for guiding the paint to the coating gun, and a watertight slide in the paint pipe. It has a piston that can be provided and a driving means that moves the piston in the paint pipe, and at the time of coating, the paint is injected in front of the piston and the piston is moved toward the coating gun. The coating apparatus further comprises a valve unit provided between the paint inlet of the coating gun and the tip of the paint pipe, the valve unit having one end communicating with the paint inlet of the coating gun and the other end. A paint passage communicating with the paint pipe, a first cleaning fluid passage communicating with the paint passage, a waste liquid passage communicating with the paint passage, and a paint passage communicating with the paint inlet of the coating gun. And closes the first valve, the first
There is provided a coating apparatus having a second valve for opening and closing the cleaning fluid passage of 1. and a third valve for opening and closing the waste fluid passage (claim 1).

In this coating apparatus, since the valve unit is provided between the paint introduction port of the coating gun and the tip of the paint pipe, the first valve, the second valve and the By selectively opening and closing the third valve and supplying the cleaning fluid from the first cleaning fluid passage, the residual paint between the piston forward end and the coating gun can be efficiently removed by an operation different from the paint piping. Can be washed.

Specifically, the cleaning operation is carried out by supplying air or cleaning liquid to the first cleaning fluid passage with the first to third valves opened to remove the residual paint between the piston and the coating gun. Extrude and discard and clean paint passages.

(2) Although not particularly limited in the above invention, in the valve unit according to the above invention, a second cleaning fluid passage communicating with the coating gun side of the first valve,
A fourth valve for opening and closing the second cleaning fluid passage may be further provided (claim 3).

With this coating apparatus, when changing colors, etc.
First valve, second valve, third valve and fourth
Valve is selectively opened and closed to supply the cleaning fluid from the first cleaning fluid passage and the second cleaning fluid passage, respectively. The residual paint can be efficiently washed. In particular, since the cleaning path is divided into two systems, the first cleaning fluid passage and the second cleaning fluid passage, the cleaning can be performed in parallel and the cleaning time can be shortened.

Specifically, the cleaning operation is performed by air or cleaning liquid in each of the first cleaning fluid passage and the second cleaning fluid passage with the first valve closed and the second to fourth valves opened. To supply. As a result, the residual paint between the piston and the painting gun is pushed out by another system and discarded, and the paint passage is washed.

(3) Although not particularly limited in the above invention, in the valve unit according to the above invention, an outer diameter smaller than the inner diameter of the paint passage between the second valve and the tip of the paint pipe in the paint passage. It is also possible to provide the hollow tube of No. 3 and to provide the third valve so as to face the space between the hollow tube and the inner wall of the paint passage (Claim 5).

At this time, it is more preferable to provide a funnel-shaped intake inclined portion at the end of the paint passage on the paint pipe side (claim 6).

In this coating apparatus, a hollow pipe having an outer diameter smaller than the inner diameter of the paint passage is provided between the second valve and the tip of the paint pipe in the paint passage so that the paint passage between them can be It has a so-called double tube structure. Therefore, when the cleaning fluid is supplied from the first cleaning fluid passage, the cleaning fluid passes through the inner space of the hollow tube and is then injected into the front space of the piston, thereby improving the cleaning performance of the residual paint on the front surface of the piston. It will be different. The cleaning fluid after cleaning passes through the outer space of the hollow tube and is discarded from the third valve to the waste fluid passage. The flow is prevented from becoming smooth and staying.

(4) Although not particularly limited in the above invention, in the valve unit according to the above invention, at least one of the inlet of the first cleaning fluid passage, the outlet of the waste liquid passage and the inlet of the second cleaning fluid passage is provided. More preferably, after electrically connecting the electrically insulating pipes to all of them and cleaning the valve unit, it is more preferable to fill the electrically insulating pipes with an insulating fluid such as air or an organic solvent (claim 2,
4).

Even if a high voltage is applied at the time of coating with the next color, the piping for supplying the cleaning fluid to the valve unit is made into an electrically insulating piping and the electrically insulating piping is filled with the insulating fluid for cleaning. The current can be prevented from leaking from the electrically insulating pipe.

(5) In the above invention, if a conductive coating material is used as the coating material (Claim 7), the effect of the present invention is more exerted, but it can also be applied to a non-conductive coating material.
In particular, in the coating apparatus of the present invention, most of the paint in the paint pipe is extruded, so that the portion that needs to be washed at the time of color change is significantly reduced, and the sliding action of the piston prevents the paint from adhering to the inner wall of the paint pipe. Greater cleanliness as the colored paint is scraped off. As a result, it is possible to use a conductive paint and a non-conductive paint that should not be mixed in nature.

[0023]

According to the invention described in claims 1 to 7, it is possible to efficiently clean the residual paint between the advance limit of the piston and the coating gun by an operation other than the operation for cleaning the paint pipe. Therefore, the cleaning time can be shortened, and the color change time can be shortened, and the production speed of the coating process can be increased.

According to the third aspect of the present invention, the cleaning path of the valve unit is divided into two systems, that is, the first cleaning fluid passage and the second cleaning fluid passage. Therefore, the cleaning time can be further shortened and the cleaning property can be improved.

According to the fifth aspect of the present invention, since the supplied cleaning fluid is sprayed from the hollow tube to the front space of the piston, the cleaning performance of the residual paint on the front surface of the piston is improved.

According to the sixth aspect of the present invention, the funnel-shaped intake inclined portion makes the flow of the fluid into the outer space of the hollow tube smooth, and prevents the residual paint from accumulating.

According to the second and fourth aspects of the present invention, even if a high voltage is applied during the next color coating, it is possible to prevent the current from leaking from the electrically insulating pipe.

According to the seventh aspect of the present invention, it is possible to use the conductive paint and the non-conductive paint that should not be originally mixed together in the same paint pipe.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. First Embodiment FIG. 1 is a schematic view showing a usage pattern of a coating apparatus of the present invention, FIG.
3 is a schematic configuration diagram showing an embodiment of the coating apparatus of the present invention, FIG.
FIG. 3 is a sectional view showing an embodiment of a valve unit according to the coating apparatus of the present invention.

As shown in FIGS. 1 and 2, the coating apparatus 1 of this embodiment is a bell-type electrostatic coating gun 11 to which a high voltage of −90 kV to −60 kV is applied, and this coating gun 11.
Flexible paint pipe 12 (hereinafter, also referred to as paint hose 12) for guiding the paint to the paint pipe 12
And a manifold 131 of the color change valve unit 13 inside the paint pipe 12 for performing a color change operation of the paint.
14 that can slide in a watertight state inside the container, drive means 15 that moves this piston 14, and paint hose 1
Valve unit 1 provided between the 2 and the coating gun 11
7 and.

The coating apparatus 1 of this embodiment can be mounted on a coating robot R and used in a coating line as shown in FIG. 1, for example. In the example shown in the figure, the coating robot R
The coating gun 11 is attached to the hand H, the coating hose 12 is fixed to the arm A using the mount M, and the drive means 15 is arranged outside the coating booth. The valve unit 17 described later is mounted on the mount M2.
Is fixed to the arm A using. The hose connected to the valve unit 17 is inserted inside the arm A.

In this case, it is preferable to install at least the driving means 15 outside the coating booth, which is possible with the coating apparatus 1 of this embodiment. This is for the following reason. That is, there is no problem if all paints used in the coating booth are non-solvent type (non-dangerous substances), but if it is a mixed line of solvent type paint and non-solvent type paint, use it for the coating equipment. It is necessary to make the drive motor and electric wiring used to be explosion-proof specifications, which increases the cost of equipment. However, the drive motors 154, 155 that require explosion-proof specifications
Since it is installed outside the painting booth, it is not necessary to make these explosion-proof even for mixed lines of solvent-based paint.
The cost can be reduced. Further, the driving means 15
Installing the outside of the painting booth will also improve the workability of maintenance and inspection.

The bell type electrostatic coating gun 11 has a trigger valve in the gun body, and when the trigger valve is opened based on a command signal from the control unit of the coating apparatus 1, the paint hose 12
The paint supplied from the gun reaches the bell cup 111 provided at the tip of the gun body, and the bell cup 111 is rotated at a high speed, so that the paint supplied
Is atomized from the tip edge of the and is radially sprayed. The coating gun 11 used in the present invention is not particularly limited, and is not limited to the bell-type electrostatic coating gun, and any electrostatic coating gun such as an air atomization type electrostatic coating gun may be used. Therefore, detailed illustration is omitted in FIGS. 1 and 2.

The paint hose 12 according to this embodiment is shown in FIG.
The tip on the left side is the paint passage 1 of the valve unit 17.
The color change valve unit 13 has an outlet connected to the inlet of the color change valve unit 13. This paint hose 12 is used for the coating robot R when the coating gun 11 is mounted on the coating robot R as shown in FIG.
Bends depending on the work posture of the paint hose, so even if the paint hose bends and the paint hose bends, the piston 1
4 is preferably made of nylon-based, polytetrafluoroethylene-based, or urethane-based resin so that it can move smoothly. However, if the paint pipe 12 can be linearized at least within the moving range of the piston 14, it can be made of metal such as stainless steel. In this case, the metal such as stainless steel needs to be insulated on the outside with resin or the like.

Although the paint piping of the present invention is not limited, the paint hose 12 is provided with an inner surface layer made of a material having excellent wear resistance and is provided so as to surround the inner surface layer to prevent expansion due to the internal pressure of the piping. It is more preferable to form the reinforcing material and the outer surface layer that is provided so as to surround the reinforcing material and that is made of a flexible material that can follow the curve of the paint hose 12.

By the way, the length of the paint hose 12 can be appropriately set according to the amount of the paint used, such as long when the amount of the paint used is large and shortened when the amount of the paint used is small.

A color change valve unit 13 is connected to the right end of the paint hose 12, and each end of the manifold 131 and the paint hose 12 are watertightly connected by a joint. In the color change valve unit 13 shown in the figure, a switching valve 132 to which different paint is supplied from a paint supply source (not shown), a switching valve 133 to which compressed air is supplied, a cleaning liquid (for conductive paint, cleaning In the case of pure water, a non-conductive paint, it means a cleaning thinner. The same applies hereinafter.) And a switching valve 134 is provided. In the figure, the paint is supplied to the six switching valves 132 on the left side, but the number of these switching valves 132 may be more or less, and may be increased or decreased depending on various conditions such as the number of coating colors of the coating line to be applied. You can In addition,
The compressed air supplied to the switching valve 133 is used to push out the paint and the cleaning liquid at the time of color change, and the cleaning liquid supplied to the switching valve 134 is used to clean the pipe at the time of color change.

In the color change valve unit 13 of this embodiment, the inner diameter of the manifold 131 is equal to that of the paint hose 1.
It is formed so as to have an inner diameter substantially equal to 2. This allows the piston 14 to move smoothly from the right end of the manifold 131 to the left end of the paint hose 12.

Although not particularly limited in the present invention, the manifold 131 of the color change valve unit 13 is preferably made of an insulating material such as a synthetic resin, especially when a conductive paint is used as the paint. When the manifold 131 is made of a conductive material such as metal, the manifold 131 and the switching valves 132, 133, 1
An electric current may leak from 34 to the paint supply source side through the conductive paint.

In the coating apparatus 1 of this embodiment, from the right end of the manifold 131 of the color change valve unit 13 to the left end of the paint hose 12, a piston 14 capable of sliding in a watertight state inside these, and the piston 14 are appropriately installed. And a driving means 15 for moving at a proper speed.

As shown in the enlarged view of FIG. 3, the piston 14 includes a piston body 141 made of an insulating material, and two O-rings 142a, 142b (hereinafter collectively referred to as generically called "insulating material") for preventing leakage of paint. Also referred to as an O-ring 142), the axial length of the piston body 141 is made as short as possible so that the paint hose 12 can move smoothly even if the paint hose 12 bends. Piston body 141
Is preferably made of an insulating material such as nylon which is not deteriorated by water or an organic solvent, and the O-ring 142 is made of a material such as rubber having appropriate elasticity and having excellent wear resistance and solvent resistance. Preferably.

The O-ring 142 secures the watertightness of the paint and the like before and after the piston 14, and also the piston 1
It also has the function of improving the slidability of No. 4 and has a function of scraping off the previous color paint adhered to the inner wall of the paint hose 12 at the time of color change.

With the piston 14 retracted to the retracted limit position shown by the chain double-dashed line in FIG.
When the paint is injected into 3 and the piston 14 is advanced toward the coating gun 11, the conductive paint attached to the inner wall of the paint hose 12 is also scraped forward by the O-ring 142. Only air will exist in the rear. Therefore, even if a high voltage is applied to the coating gun 11, the piston is blocked before and after the piston 14, and the current is prevented from leaking to the rear end side of the coating hose 12.

Although not particularly limited in the present invention, as shown in FIG. 3, the piston body 141 is divided into two O-rings 142a and 142b at one end, the outer peripheral surface of the piston body 141, and the inner wall of the paint hose 12. A through hole 143 having an opening in the space S1 and the other end opening inside the hollow cable 151 described later is formed.

Due to the existence of the through hole 143, the piston 1
The paint filled in the front space S3 of No. 4 is the O-ring 142a.
Even if the paint leaks into the space S1 beyond the O-ring 142a due to deterioration or wear of the paint, the leaked paint reaches the inside of the hollow cable 151 through the through hole 143. Therefore, the paint leak can be detected by the paint detector 31 provided at the right end of the hollow cable 151.

Returning to FIG. 1 and FIG. 2, the driving means 15 for moving the piston 14 has a piston body 1 at the tip.
The hollow cable 151 fixed to 41 and two pairs of push-out rollers 152 provided near the color change valve unit 13 and rotating by sandwiching the hollow cable 151.
152 and a pulling device 153 for winding the hollow cable 151.

The push rollers 152, 152 are rotated by drive motors (not shown), and mainly the piston 14
Hollow cable 1 as it advances towards the painting gun 11.
A driving force is applied to 51, and when the piston 14 is returned in the direction opposite to the coating gun 11, the hollow cable 151 is unpinched and made free. The push-out roller 152 controls the push-out amount of the paint according to the movement of the piston 14, and the gear pump and the like conventionally required are not necessary in this embodiment. In addition, since the two pairs of extrusion rollers 152 and 152 have a mechanical structure that sandwiches the hollow cable 151 and moves the piston 14 forward, in principle, when the paint hose 12 reaches an abnormally high pressure so that the paint hose 12 ruptures, the extrusion roller 152 moves. Slip. Therefore, the safety is further enhanced.

On the other hand, the pulling device 153 is rotated in both forward and reverse directions by a drive motor (not shown) so that when the piston 14 advances toward the coating gun 11, the hollow cable 151 is fed in the same direction. Rotate to. Further, by rotating in the opposite direction, it functions when the piston 14 is returned in the direction opposite to the coating gun 11. At this time, as described above, the extrusion roller 152 is connected to the hollow cable 1.
Since it becomes free with respect to 51, the time required for the returning operation of the piston 14 is shortened by the amount that the rotation speed of the pulling device 153 is increased.

A hollow cable is adopted as the cable 151 of the present example, and it is configured to detect the leakage of the paint as described above, but the cable of the present invention is not limited to the hollow cable, It may be a real cable. Further, the pushing rollers 152 are not limited to two pairs, and may be one pair or three or more pairs.

Incidentally, it is preferable that the hollow cable 151 is made of an insulating material, but when a metal (conductive) cable is used for the cable 151 in order to enhance rigidity and durability, insulation is provided around the outer circumference of the cable 151. It is more preferable to form a coating layer to prevent current from leaking through the cable 14 due to residual humidity, moisture, paint, etc. behind the piston 14.

Particularly in this embodiment, the valve unit 17 is provided between the tip of the paint hose 12 and the coating gun 11. As shown in an enlarged scale in FIG. 3, the valve unit 17 has a valve block 171. The valve block 171 has the right end communicated with the paint hose 12 and the left end with the paint inlet 112 of the paint gun 11. Is formed with a paint passage 172. A screw hole 175 for mounting a paint hose 174 reaching the paint inlet 112 of the coating gun 11 is formed at the left end of the paint passage 172.

A hollow pipe 190 having a flange 189 at the left end is inserted and fixed between the first valve 176, which will be described later, and the paint hose 12 in the paint passage 172. The passage 172 includes the internal space 192 of the hollow tube 190, the outside of the hollow tube 190, and the paint passage 1.
It is partitioned into a space 191 between the inner wall of 72 and the space 19
1 communicates with a waste liquid passage 181 described later. In the example shown in the figure, the outer space 191 of the hollow tube 190 is
Is formed with a funnel-shaped inlet slope 173 at the right end of the first cleaning fluid passage 177 during color change cleaning.
The cleaning liquid introduced from (1) passes through the paint passage 172 and is jetted toward the piston 14, and then is smoothly introduced into the external space 191 by the suction inclined portion 173, and is introduced into the drain tank 22 via the waste liquid passage 181. Be guided.

The paint passage 172 is opened / closed by a first valve 176 provided in the middle of the paint passage 172, thereby turning on / off the supply of the paint from the paint hose 12 to the paint gun 1.
It can be turned off. As shown in the figure, the first valve 176 includes a valve seat 176a formed on the valve block 171, a valve body 176b that abuts and separates from the valve seat 176a, and a valve rod fixed to the valve body 176b. 176c
And a piston 176d fixed to the valve rod 176c and a cylinder 176e in which the piston 176d is inserted, and a driving fluid (for example, air) not shown is supplied to the front and rear of the piston 176d in the cylinder 176e. The valve body 176b opens and closes the opening of the valve seat 176a.

The valve block 171 is provided with a first cleaning fluid passage 177 which communicates with the above-mentioned coating passage 172 on the side of the coating hose 12 of the first valve 176. In the example shown in the figure, the first cleaning fluid passage 177 is used.
A screw hole 179 for mounting the insulating hose 178 reaching the switching valve unit 20 is formed at the right end of the.

The first cleaning fluid passage 177 is opened and closed by a second valve 180 provided in the middle of the passage.
Thereby, the supply of the extrusion air and the cleaning liquid from the switching valve unit 20 can be turned ON / OFF.
The second valve 180 includes a valve seat 180a formed in a valve block 171 and a valve seat 18a as shown in FIG.
Valve body 180b that abuts and separates from 0a, and valve body 180
It has a valve rod 180c fixed to b, a piston 180d fixed to the valve rod 180c, and a cylinder 180e in which the piston 180d is inserted, and a driving fluid (for example, air) not shown in the drawing is stored in the cylinder 180e. Piston 180
By supplying before and after d, the valve body 180b moves to the valve seat 180a.
Open and close the opening.

Further, the valve block 171 is provided with a waste liquid passage 181 which is on the paint hose 12 side of the first valve 176 of the above-mentioned paint passage 172 and which communicates with the external space 191 of the hollow tube 190. There is. In the example shown in the figure, a screw hole 183 for mounting the insulating hose 182 reaching the drain tank 22 is formed at the right end of the waste liquid passage 181.

The waste liquid passage 181 is opened / closed by a third valve 184 provided in the middle thereof, whereby the supply of the waste liquid to the drain tank 22 can be turned on / off. As shown in the figure, the third valve 184 includes a valve seat 184a formed in the valve block 171, a valve body 184b that abuts and separates from the valve seat 184a, and a valve rod fixed to the valve body 184b. 184c and valve rod 184c
Has a piston 184d fixed to the piston 184d and a cylinder 184e into which the piston 184d is inserted. By supplying a driving fluid (for example, air) (not shown) before and after the piston 184d inside the cylinder 184e, the valve body 184b is formed. The opening of the valve seat 184a is opened and closed.

Further, the valve block 171 is provided with a second cleaning fluid passage 185 which communicates with the above-mentioned paint passage 172 on the painting gun 11 side of the first valve 176. In the example shown in the figure, the second cleaning fluid passage 185
A screw hole 187 for mounting the insulating hose 186 reaching the switching valve unit 21 is formed at the left end of the.

The second cleaning fluid passage 185 is opened and closed by a fourth valve 188 provided in the middle thereof,
As a result, the supply of the extrusion air and the cleaning liquid from the switching valve unit 21 can be turned ON / OFF.
As shown in the figure, the fourth valve 188 includes a valve seat 188a formed in the valve block 171 and a valve seat 18a.
8a, a valve body 188b that abuts and separates from the 8a, and a valve body 188.
It has a valve rod 188c fixed to b, a piston 188d fixed to the valve rod 188c, and a cylinder 188e in which the piston 188d is inserted, and a drive fluid (for example, air) not shown in the drawing is stored in the cylinder 188e. Piston 188
By supplying before and after d, the valve body 188b moves to the valve seat 188a.
Open and close the opening.

By the way, application of high pressure to the coating gun 11, switching of the trigger valve, color change valve unit 13
The switching of the switching valves 132, 133, 134, the operation of the drive motor of the extrusion roller 152, the operation of the drive motor of the pulling device 153, and the switching of the valves of the valve unit 17 are performed by control signals from a control device (not shown). Controlled.

A control signal sent from a management device (not shown) and a detection signal from a position sensor for detecting the current position of the piston 14 are input to such a control device. The position sensor is arranged at a position where a detection signal is sent when the piston 14 is located rearward of the color change valve unit 13, that is, a position of the piston 14 shown by a chain double-dashed line in FIG. Position), a position for sending a detection signal when the piston 14 is positioned slightly forward of the color change valve unit 13 (hereinafter, also referred to as an application position), and the piston 14 is a part of the coating gun 11. It is desirable to provide it at a position (hereinafter, also referred to as a forward limit position) where a detection signal is sent when the valve unit 17 is located at the forward limit, which is a position immediately before the valve unit 17.

Next, the operation will be described. FIG. 4 shows a one-cycle procedure for supplying paint to the coating apparatus 1 of the present embodiment, applying the paint from the coating gun 11 to the object to be coated, and waiting for the next object to be coated. is there.

First, the coating is started from the state where the piston 14 is in the application possible position. In this state, the piston 14 is located slightly in front of the color change valve unit 13, and the space S3 of the paint hose 12 from the piston 14 to the bell cup 113 is filled with the paint P to be applied to the object to be coated. ing. As described above, this filling amount is approximately equal to the amount of the coating material applied by the coating gun 11. Further, in the paint hose 12 behind the piston 14, the space S2 is filled with air. Further, in the state of the valve block 17, the first valve 176 opens the paint passage 172, and the other valves, that is, the second valve 180, the third valve 184 and the fourth valve 188 are all closed. . As a result, the paint hose 12 communicates only with the paint hose 174 reaching the paint inlet 112 of the coating gun 11 via the paint passage 172.

From this state, a high voltage is applied to the coating gun 11 and the trigger valve 112 is opened (step 1). As a result, an electric current flows from the coating gun 11 to the conductive coating P, but the space S2 behind the piston 14 is filled with air, so that this exerts the function of a so-called voltage block, and the front and rear of the piston 14 concerned. Electrically insulated by.

Almost at the same time as the opening operation of the trigger valve 112, the pushing roller 152 is operated to feed the cable 151 and the piston 14 is advanced toward the coating gun 11. The opening operation of the trigger valve 112 and the piston 14
The coating robot R
Depending on the posture, the bell cup 113 of the coating gun 11 may face sideways or obliquely upward. Therefore, in order to stabilize the initial discharge amount and the atomization pattern, the pushing operation of the piston 14 is performed by the trigger valve 112. The opening operation may be preceded by 0.1 to 0.3 seconds. By doing so, particularly in a rotary atomizing type coating gun, it becomes an effective means for preventing paint sagging at the tip of the feed tube.

The pushing speed when pushing out the piston 14 is related to the discharge amount from the bell cup 113. That is, when the extrusion speed is increased, the discharge amount increases, and when the extrusion speed is decreased, the discharge amount decreases, so that the optimum extrusion speed is sent from the control device to the driving means 15.

When the piston 14 advances toward the coating gun 11, the paint P is supplied to the coating gun 11 as described above, but the piston 14 reaches the forward limit position immediately before the valve unit 17 and is provided there. When detected by the position sensor, the pushing roller 152 and the pulling device 1
At the same time as stopping 53, the application of high voltage to the coating gun 11 is stopped, and the coating on the article is completed (steps 3 and 4).

The operations thereafter are the color change cycle.
When the coating color of the next object to be coated is the same, the following color change cycle is not performed and the process jumps to step 12.

First, with the piston 14 in the forward limit position as shown in FIG. 3, the paint P remaining between the tip of the piston 14 and the coating gun 11 is washed. This involves closing the first valve 176 and opening the fourth valve 188. At the same time, the second valve 180 and the third valve 184 are also opened (step 5). And
Extrusion air is supplied through the switching valve units 20 and 21 (steps 6 and 7).

Extrusion air supplied through the switching valve 21 reaches the second cleaning fluid passage 185 through the insulating hose 186 and passes through the opened fourth valve 188. Here, although the previous color paint P remains between the closed first valve 176 and the coating gun 11, it is pushed out to the coating gun 11 by the previous extruding air and discarded.

Next, the valve of the switching valve unit 21 is switched to supply the cleaning liquid (step 8). The cleaning liquid passes through the insulating hose 186 to reach the second cleaning fluid passage 185, and further passes through the opened fourth valve 188 to reach the paint passage 172, the paint hose 174, and the coating gun 11, and from here. Be discarded. By continuing the supply of the cleaning liquid for a predetermined time, the paint passage 172 from the first valve 176 to the coating gun 11 can be cleaned.

Next, the valves of the switching valve unit 21 are switched again to supply the extruded air (step 1
0). This allows the insulating hose 186, second
Cleaning fluid passage 185, paint passage 172, paint hose 1
The cleaning liquid filled in 74 and the coating gun 11 is pushed out from the coating gun 11 and discarded.

After this, steps 8 and 10 may be repeated a plurality of times, but at the end, extruded air is supplied for several seconds to collect air in the second cleaning fluid passage 185 and the insulating hose 186. deep. Thereby, even if a high voltage is applied to the coating gun 1 during the next color coating, the current can be prevented from leaking through this path. Therefore, it is desirable to adopt an insulating hose 186 and make its length 3 m or more.

On the other hand, the extruded air supplied through the switching valve 20 reaches the first cleaning fluid passage 177 through the insulating hose 178, and the opened second valve 180.
Pass through. Here, between the closed first valve 176 and the piston 14, the internal space 19 of the hollow tube 190 is provided.
Although the pre-colored paint P remains in both 2 and the external space 191, the extruded air that has passed through the second valve 180 is guided to the internal space 191 of the hollow tube 190, so that the residual paint P remains there. Push it to the piston 14 side. The extruded front color paint P, the paint P remaining on the front surface of the piston 14, and the paint P remaining in the outer space 191 of the hollow tube 190 are opened by the pressure of the extruding air. 184 and is pushed out to the third valve 184.
Is discharged to the drain tank 22 through the waste liquid passage 181 and the insulating hose 182.

Next, the valve of the switching valve unit 20 is switched to supply the cleaning liquid (step 9). This cleaning liquid reaches the first cleaning fluid passage 177 through the insulating hose 178, and further passes through the second valve 180 that is opened to reach the internal space 192 of the hollow tube 190. Then, the internal space 192 is injected toward the piston 14. This injection cleans the tip of the piston 14 and prevents the color mixture of the previous color paint. Piston 14
The cleaning liquid injected into the front space S3 of the hollow pipe 190 reaches the waste liquid passage 181 from the external space 191 of the hollow tube 190 via the third valve 184, and is discarded to the drain tank 22 via the insulating hose 182. By continuing the supply of the cleaning liquid for a predetermined time, the paint passage 172 from the piston 14 to the first valve 176 can be cleaned. It should be noted that due to the intake inclined portion 173 formed at the right end of the paint passage 172, the piston front space S3 to the external space 191 of the hollow tube 190 is increased.
The flow of cleaning liquid to the unit becomes smooth.

Next, the valves of the switching valve unit 20 are switched again to supply the extruded air (step 1
1). This allows the insulating hose 178, the first
Cleaning fluid passage 177 and internal space 19 of hollow tube 190
2, front space S of piston 14, outer space 191, hollow tube 190, waste liquid passage 181, and insulating hose 182
The cleaning liquid that has been filled in is discharged to the drain tank 22 and discarded. After that, the above steps 9 and 11 may be repeated a plurality of times, but at the end, the extruded air is supplied for several seconds to supply the first cleaning fluid passage 177 and the insulating hose 178, and the waste liquid passage 181 and the insulating material. Hose 18
Store air in 2 respectively. Thereby, even if a high voltage is applied to the coating gun 11 during the next color coating, the current can be prevented from leaking through these paths.
Therefore, it is desirable that the insulating hoses 178 and 182 are adopted and the lengths thereof are each set to 3 m or more.

In this example, in the cleaning steps of Steps 5 to 11, independent cleaning systems are formed before and after the first valve 176, and cleaning is performed in parallel, so that the cleaning time is shortened accordingly. In addition, cleaning performance is improved by cleaning separately.

Returning to FIG. 4, when the cleaning around the valve unit 17 is completed, the first valve 1 of the valve unit 17 is
76 is opened and the second to fourth valves 180, 18 are opened.
Close 4,188. Then, the extrusion rollers 152, 15
2 is made free, and the pulling device 153 is rotated in the opposite direction to the conventional one, whereby the piston 14 is retracted (step 12). When the piston 14 retracts, the air behind the piston 14 (on the right side in the figure) is compressed. Therefore, in order to make the operation of the piston 14 smooth, install a dump valve or the like and keep it open. Is preferred.

When it is detected by the position sensor that the piston 14 has reached the backward limit position (step 13), the switching valves 133 and 134 of the color change valve unit 13 are alternately opened and closed, and the paint in front of the piston 14 is opened. Hose 12
A cleaning liquid and extrusion air are supplied to the inner space S3 (step 14). However, in the coating apparatus 1 of this example, since the cleaning from the valve unit 17 to the coating gun 11 has been completed, the main color paint remaining on the inner wall of the paint hose 12 and the color change valve unit 13 is mainly cleaned. It is a step for. Therefore, this step 14 may be omitted if there are other cleaning means.

When the inside of the paint hose 12 becomes clean, one of the switching valves 132 of the color change valve unit 13 is opened to supply the paint P of the next color into the paint hose 12 in front of the piston 14 (step 15). . At this time, the opening / closing timing of the switching valve 132 is controlled in accordance with the amount of paint used so that the filling amount is suitable for the coating color. This minimizes the amount of paint left over and discarded after painting.

When the next color paint P is supplied, the extrusion roller 15
2, 152 and the pulling device 153 are driven to advance the piston 14 (step 16). When it is detected by the position sensor that the piston 14 has reached the position where the piston 14 can be applied slightly ahead of the color change valve unit 13 (step 17), the pushing roller 152 and the pulling device 153 are stopped and the coating gun 1
The trigger valve of No. 1 is closed, and the coating start signal for the next color is waited (step 18).

The following effects can be expected in the coating apparatus 1 of this embodiment. First, since the piston 14 is provided in the paint hose 12 and the conductive paint P is supplied to the front of the piston 14 and pushed out to the coating gun 11, an air layer is formed behind the piston 14. This is the function of the so-called voltage block. Therefore, the existing bell-type electrostatic coating gun or the like having high coating efficiency can be used as it is, and both the adoption of the conductive coating and the improvement of coating efficiency can be achieved. Further, since the existing painting gun can be used as it is, there is no need to replace or modify the painting gun.

Further, by controlling the extrusion speed of the piston, the discharge amount can be easily controlled, and an expensive device such as a gear pump conventionally required can be substituted.
A reduction in equipment costs is achieved.

Further, even in the color changing operation, the piston can be used to push out the paint to the trigger valve, so that the amount of the paint to be discarded at the time of the color change is minimized, and the cost of the paint is reduced and environmental measures such as waste liquid treatment are taken. It is advantageous in terms.

The amount of paint used (discharging amount) per coating gun varies depending on the change of the coating cycle time, the difference of the object to be coated, the difference in the coating color such as the solid content of the coating, the required quality such as the film thickness, and the like. However, in the coating apparatus of the present embodiment, the length of the paint hose 12 is set to the maximum amount of paint to be used, and the amount of paint required is filled in this to apply the paint. You can deal with it flexibly.

Furthermore, the coating apparatus 1 of this embodiment can be applied not only to the conductive paint but also to the non-conductive paint as it is.

Further, since all the paint in the paint hose 12 is pushed out by the piston 14, the area to be cleaned is remarkably reduced, which makes it possible to clean the inside of the system in a short time. Further, as a result of the improved cleanability, it is possible to change the color of the conductive paint and the non-conductive paint with the same coating device.

Further, in the coating apparatus 1 of this embodiment, the paint is filled into the paint hose 12 immediately before the coating,
The problem of pigment settling does not occur even with metallic paints and mica paints. Also, when applied to a coating gun using a cartridge, the problem of pigment settling is solved.

In addition to this, the piston body 141 has a first
Through hole 143 of which one end has two O-rings 142a,
Since it is exposed to the space S1 partitioned by 142b and the other end is exposed to the inside of the first hollow cable 151a, the paint filled in the space S3 in front of the piston 14 is O-ring 142.
Even if leakage occurs due to deterioration or wear of a, this is detected by the paint detector 31 via the first through hole 143 and the hollow cable 151. Therefore, the deterioration / wear state of the O-ring 142 can be inspected without disassembling the piston 14, and the leakage of the paint can be prevented.

Further, in the coating apparatus 1 of this embodiment, since the hollow pipe 190 is provided in the paint passage 172, the cleaning liquid supplied from the switching valve unit 20 is the piston 14
Is jetted toward the front side, which improves the cleaning performance of the front space S3 of the piston 14. Further, since the intake slope portion 173 is formed at the right end of the paint passage 172,
The cleaning liquid that has cleaned the front space S3 of the piston 14 is smoothly guided to the external space 191.

Further, since the cleaning operation is performed in parallel before and after the first valve 176, the color changing time can be shortened. Furthermore, after the cleaning is completed, the insulating hoses 178, 1
Since 82 and 186 are filled with air, even if a high pressure is applied to the coating gun 11 at the time of the next color coating, the insulating hoses 178, 182 and 186 are blocked and leakage from this can be prevented.

Second Embodiment FIG. 5 is an enlarged sectional view of a valve unit 17 showing another embodiment of the coating apparatus of the present invention. In this example, as compared with the above-described first embodiment, the fourth valve 188 of the first embodiment is used.
The switching valve unit 21 and the insulating hose 186 are omitted. The same members as those shown in FIG. 3 are designated by the same reference numerals, and detailed description thereof will be omitted.

A hollow tube 190 is provided in the paint passage 172 formed in the valve block 171, and the collar portion 189 of the first embodiment shown in FIG. 3 is omitted.
The basic function is the same as that of the first embodiment, and the hollow tube 19
The inner space 192 of 0 serves as a passage for the paint, and the hollow tube 1
The external space 191 of 90 communicates with the waste liquid passage 181 via the third valve 184.

Next, the operation of this example will be described. FIG. 6 shows a one-cycle procedure for supplying paint to the coating apparatus 1 of the present embodiment, applying the paint from the coating gun 11 to the object to be coated, and waiting for the next object to be coated. is there.

Since the operation from step 1 to step 4 in the figure is the same as that of the first embodiment described in FIG. 4,
The color change cycle of step 5 will be described. When the coating color of the next object to be coated is the same, the following color change cycle is not performed and the process jumps to step 9.

First, as shown in FIG. 5, with the piston 14 in the forward limit position, the paint P remaining between the tip of the piston 14 and the coating gun 11 is washed. To do this, all of the first valve 176, the second valve 180 and the third valve 184 are opened (step 5). Then, the extrusion air is supplied through the switching valve unit 20 (step 6).

Extrusion air supplied through the switching valve 20 passes through the insulating hose 178, reaches the first cleaning fluid passage 177, and passes through the opened second valve 180. Here, since the previous color paint P remains between the front space S3 of the piston 14 and the coating gun 11, the extruded air reaching the second valve 180 is from here to the coating gun 11 side and the piston 14 Branch to the side and extrude residual paint respectively. That is, the extruded air from the second valve 180 is applied to the paint passage 172 exposed by the second valve 180.
Between the paint gun 11 and the paint gun 11
Extrude to and discard. On the other hand, similarly, the second valve 18
The extruded air from 0 removes the paint remaining between the paint passage 172 exposed by the second valve 180 and the piston 14 from the outer space 191 of the hollow tube 190 and the third valve 18.
4. It is pushed out to the drain tank 22 through the waste liquid passage 181 and the insulating hose 182 for disposal.

Next, the valve of the switching valve unit 20 is switched to supply the cleaning liquid (step 7). This cleaning liquid is also used for the insulating hose 17 like the above-mentioned extruded air.
8 to the first cleaning fluid passage 177 and further to the second valve 180 which is open. Then, from here, one reaches the paint hose 174 and the coating gun 11 from the opened first valve 176, and is discarded from here. By continuing the supply of the cleaning liquid for a predetermined time, the paint passage 172 from the first valve 176 to the coating gun 11 can be cleaned. The other passes through the internal space 192 of the hollow tube 190 and jets toward the piston 14. As a result, the cleanability of the previous color paint remaining in the front space S3 of the piston 14 is improved. Then, the cleaning liquid injected into the front space S3 of the piston 14 reaches the waste liquid passage 181 from the external space 191 of the hollow tube 190 via the third valve 184, and is discarded into the drain tank 22 via the insulating hose 182. To be done. By continuing the supply of the cleaning liquid for a predetermined period of time, the piston 14 moves to the first valve 17
The paint passage 172 leading to 6 can be cleaned. It should be noted that the intake inclined portion 17 formed at the right end of the paint passage 172.
3 facilitates the flow of the cleaning liquid from the piston front space S3 to the external space 191 of the hollow tube 190.

Next, the valves of the switching valve unit 20 are switched again to supply the extruded air (step 8).
As a result, the insulating hose 178, the first cleaning fluid passage 177, the internal space 192 of the hollow tube 190, the front space S3 of the piston 14, and the external space 19 of the hollow tube 190 are provided.
1. Waste liquid passage 181, insulating hose 182, and paint passage 17 on the painting gun 11 side of the second valve 180.
The cleaning liquid filled in 2 and the paint hose 174 is pushed out to the drain tank 22 or the coating gun 11 and discarded.
After this, steps 6 and 7 may be repeated a plurality of times, but at the end, extrusion air is supplied for several seconds to
Air is stored in the cleaning fluid passage 177 and the insulating hose 178, and the waste fluid passage 181 and the insulating hose 182, respectively. Thereby, even if a high voltage is applied to the coating gun 11 during the next color coating, the current can be prevented from leaking through these paths. Therefore, it is desirable that the insulating hoses 178 and 182 are adopted and the lengths thereof are each set to 3 m or more.

In this example, in the cleaning steps of step 5 to step 8, since the cleaning system is constituted by the extruded air and the cleaning liquid from one switching valve 20, the apparatus structure and control can be simplified accordingly. It also contributes to cost reduction.

Returning to FIG. 6, when the cleaning around the valve unit 17 is completed, the first valve 1 of the valve unit 17 is
Leave 76 open and the second and third valves 18
Close 0,184. Then, the extrusion rollers 152, 15
2 is made free, and the pulling device 153 is rotated in the direction opposite to that in the past, whereby the piston 14 is retracted (step 9). When the piston 14 retracts, the air behind the piston 14 (on the right side in the figure) is compressed. Therefore, in order to make the operation of the piston 14 smooth, install a dump valve or the like and keep it open. Is preferred.

When the position sensor detects that the piston 14 has reached the backward limit position (step 10), the switching valves 133 and 134 of the color change valve unit 13 are alternately opened and closed to remove the paint in front of the piston 14. Hose 12
A cleaning liquid and extrusion air are supplied to the inner space S3 (step 11). However, in the coating apparatus 1 of this example, since the cleaning from the valve unit 17 to the coating gun 11 has been completed, the main color paint remaining on the inner wall of the paint hose 12 and the color change valve unit 13 is mainly cleaned. It is a step for. Therefore, this step 14 may be omitted if there are other cleaning means.

When the inside of the paint hose 12 becomes clean, one of the switching valves 132 of the color change valve unit 13 is opened to supply the paint P of the next color into the paint hose 12 in front of the piston 14 (step 12). . At this time, the opening / closing timing of the switching valve 132 is controlled in accordance with the amount of paint used so that the filling amount is suitable for the coating color. This minimizes the amount of paint left over and discarded after painting.

When the next color paint P is supplied, the extrusion roller 15
2, 152 and the pulling device 153 are driven to advance the piston 14 (step 13). When it is detected by the position sensor that the piston 14 has reached the position where the piston 14 can be applied slightly ahead of the color change valve unit 13 (step 14), the extrusion roller 152 and the pulling device 153 are stopped, and the coating gun 1
The trigger valve of No. 1 is closed and the coating start signal for the next color is waited for (step 15).

The following effects can be expected in the coating apparatus 1 of this embodiment. First, since the piston 14 is provided in the paint hose 12 and the conductive paint P is supplied to the front of the piston 14 and pushed out to the coating gun 11, an air layer is formed behind the piston 14. This is the function of the so-called voltage block. Therefore, the existing bell-type electrostatic coating gun or the like having high coating efficiency can be used as it is, and both the adoption of the conductive coating and the improvement of coating efficiency can be achieved. Further, since the existing painting gun can be used as it is, there is no need to replace or modify the painting gun.

Further, by controlling the extrusion speed of the piston, the discharge amount can be easily controlled, and an expensive device such as a gear pump conventionally required can be substituted.
A reduction in equipment costs is achieved.

Further, even in the color changing operation, the paint can be pushed out to the trigger valve by using the piston, so that the amount of the paint to be discarded at the time of the color changing is minimized, and the cost of the paint is reduced and the environmental measures such as waste liquid treatment are taken. It is advantageous in terms.

Further, the amount of paint used (discharging amount) per coating gun varies depending on the change of the coating cycle time, the difference of the object to be coated, the difference in the coating color such as the solid content of the paint, the required quality such as the film thickness, and the like. However, in the coating apparatus of the present embodiment, the length of the paint hose 12 is set to the maximum amount of paint to be used, and the amount of paint required is filled in this to apply the paint. You can deal with it flexibly.

Further, the coating apparatus 1 of this embodiment can be applied to not only the conductive paint but also the non-conductive paint as it is.

Further, since all the paint in the paint hose 12 is pushed out by the piston 14, the area to be cleaned is remarkably reduced, which makes it possible to clean the inside of the system in a short time. Further, as a result of the improved cleanability, it is possible to change the color of the conductive paint and the non-conductive paint with the same coating device.

Further, in the coating apparatus 1 of this embodiment, the paint is filled into the paint hose 12 immediately before the coating,
The problem of pigment settling does not occur even with metallic paints and mica paints. Also, when applied to a coating gun using a cartridge, the problem of pigment settling is solved.

In addition to this, the piston body 141 is provided with a first
Through hole 143 of which one end has two O-rings 142a,
Since it is exposed to the space S1 partitioned by 142b and the other end is exposed to the inside of the first hollow cable 151a, the paint filled in the space S3 in front of the piston 14 is O-ring 142.
Even if leakage occurs due to deterioration or wear of a, this is detected by the paint detector 31 via the first through hole 143 and the hollow cable 151. Therefore, the deterioration / wear state of the O-ring 142 can be inspected without disassembling the piston 14, and the leakage of the paint can be prevented.

Further, in the coating apparatus 1 of the present embodiment, since the hollow pipe 190 is provided in the coating passage 172, the cleaning liquid supplied from the switching valve unit 20 is the piston 14
Is jetted toward the front side, which improves the cleaning performance of the front space S3 of the piston 14. Further, since the intake slope portion 173 is formed at the right end of the paint passage 172,
The cleaning liquid that has cleaned the front space S3 of the piston 14 is smoothly guided to the external space 191.

Further, since the first valve 176 is subjected to the cleaning operation with only one system of extrusion air and the cleaning liquid,
The device configuration and control can be simplified, contributing to cost reduction and shortening the color change time. Further, since the insulating hoses 178 and 182 are filled with air after the cleaning is completed, even if a high pressure is applied to the coating gun 11 at the time of the next color coating, the insulating hoses 178 and 182 are blocked by the leakage, and leaks from this area occur. Can be prevented.

The embodiments described above are described for facilitating the understanding of the present invention and not for limiting the present invention. Therefore, each element disclosed in the above-described embodiment is intended to include all design changes and equivalents within the technical scope of the present invention.

[Brief description of drawings]

FIG. 1 is a schematic view showing a usage pattern of a coating apparatus of the present invention.

FIG. 2 is a schematic configuration diagram showing an embodiment of a coating apparatus of the present invention.

FIG. 3 is a sectional view showing an embodiment of a valve unit according to the coating apparatus of the present invention.

FIG. 4 is a flowchart showing an example of the operation of the coating apparatus of FIGS. 2 and 3.

FIG. 5 is a cross-sectional view showing another embodiment of the valve unit according to the coating apparatus of the present invention.

6 is a flowchart showing an example of the operation of the coating apparatus of FIG.

[Explanation of symbols]

1 ... Coating equipment 11 ... Painting gun 111 ... Bell cup 112 ... Paint inlet 12 ... Paint hose (paint piping) 13 ... Color change valve unit 14 ... Piston 15 ... Driving means 151 ... Hollow cable 152 ... Extrusion roller 153 ... Pulling device 17 ... Valve unit 171 ... Valve block 172 ... Paint passage 173 ... Inclination slope 176 ... First valve 177 ... First cleaning fluid passage 178 ... Insulating hose (electrically insulating piping) 180 ... second valve 181 ... Waste liquid passage 182 ... Insulating hose (electrically insulating piping) 184 ... Third valve 185 ... Second cleaning fluid passage 186 ... Insulating hose (electrically insulating piping) 188 ... Fourth valve 190 ... Hollow tube 191 ... External space 192 ... Internal space

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiromi Nonomura             Nissan, Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan             Inside the automobile corporation (72) Inventor Yasuo Takamizu             2-6-1, Nishi-Shinjuku, Shinjuku-ku, Tokyo Stocks             In-house company (72) Inventor Masumi Hara             5050 Asahi Sana, Nitta-dong, Asahizen-cho, Owariasahi-shi, Aichi             Click Co., Ltd. F-term (reference) 4F034 AA03 BA27 BB04 DA16

Claims (7)

[Claims] 1. A paint gun to which a voltage is applied, a paint pipe for guiding paint to the paint gun, a piston slidably provided in the paint pipe in a watertight state, and the piston in the paint pipe. In a coating device for injecting the coating material in front of the piston and moving the piston toward the coating gun at the time of coating, a coating material introducing port of the coating gun and the coating pipe. Further comprising a valve unit provided between the paint unit and one end, the valve unit has a paint passage, one end of which communicates with the paint inlet of the paint gun and the other end of which communicates with the paint pipe,
A first cleaning fluid passage communicating with the paint passage, a waste liquid passage communicating with the paint passage, a first valve for opening and closing the paint passage communicating with the paint inlet of the coating gun, and the first cleaning A coating apparatus having a second valve that opens and closes a fluid passage and a third valve that opens and closes the waste fluid passage. 2. A cleaning fluid is supplied to the inlet of the first cleaning fluid passage through an electrically insulating pipe, and the waste liquid reaching the outlet of the waste liquid passage is discarded through the electrically insulating pipe, and after cleaning. The coating apparatus according to claim 1, wherein the electrically insulating pipe is filled with an insulating fluid. 3. The method according to claim 1, further comprising a second cleaning fluid passage communicating with the coating gun side of the first valve, and a fourth valve opening / closing the second cleaning fluid passage. The described coating equipment. 4. The cleaning fluid is supplied to the inlet of the second cleaning fluid passage through an electrically insulating pipe, and after cleaning, the electrically insulating pipe is filled with an insulating fluid. Coating equipment. 5. A hollow pipe having an outer diameter smaller than the inner diameter of the paint passage is provided between the second valve and the tip of the paint pipe in the paint passage, and the third valve is 5. The space is provided so as to face the space between the hollow pipe and the inner wall of the paint passage.
The coating apparatus according to any one of 1. 6. The coating apparatus according to claim 5, wherein a funnel-shaped inlet inclined portion is provided at the tip of the paint passage on the paint pipe side. 7. The coating material is a conductive coating material.
The coating apparatus according to any one of 1.