JPH11128784A - Electrostatic coating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To supply a fixed amount of coating to be discharged from a storage- type pump to a coating machine in such a state that a high voltage is prevented from leaking to a coating source side and thereby, make a coat finish better. SOLUTION: This electrostatic coating device is of such a construction that a coating is supplied to a storage-type pump 19 through a coating hose 33 which constitutes an insulating coat flow path from a color switching valve device 34, and a gear pump 9 is arranged as a positive displacement pump on a coating outflow hose 8 between the storage-type pump 19 and an electrostatic coating machine 1. Under this construction, the coating contained in a coating hose 33 is drained and the coating hose 33 is cleaned to form a high voltage shut-off part. Thus it is possible to prevent high voltage applied to the coating from leaking. Further, the coating discharged from the storage-type pump 19 can be supplied to the electrostatic coating machine 1 at a constant flow rate complying with coating conditions by a gear pump 9 to make a coat formed by applying the coating uniform.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic coating apparatus suitable for electrostatic coating of a paint having a small electric resistance such as a water-based paint.

[0002]

2. Description of the Related Art In general, paints used for electrostatic coating in which a high voltage is applied to a paint and the charged paint is sprayed toward an object to be coated are roughly classified into a solvent paint and a water-based paint. In recent years, it has become common to refrain from using solvent paints and to use environmentally friendly aqueous paints in view of environmental issues such as pollution. However, since the electric resistance value of the water-based paint is smaller than that of the solvent paint, when this water-based paint is applied by an electrostatic coating device, a high voltage applied to the water-based paint passes through the paint and is applied to a paint tank and a pressure feeder. Leakage to the paint source side, such as a pump, reduces the charging voltage of the paint and reduces the efficiency of applying the paint to an object to be coated.

[0003] Therefore, there is an electrostatic coating apparatus which is configured to prevent leakage of high voltage to the paint source side. This electrostatic coating apparatus is provided with a coating material for supplying one or more colors of coating material. Supply means, formed by an insulating material,
An insulating paint flow path whose upstream side is connected to the paint supply means,
A storage pump provided on the downstream side of the insulating coating flow path, for temporarily storing the coating supplied from the coating supply means, and discharging the coating; and a coating provided on the discharge side of the storage pump. An outflow passage, provided at the tip end of the paint outflow passage, atomizes while applying a high voltage to the paint supplied from the storage pump, and sprays the charged paint charged at a high voltage toward the object to be coated. A coating machine, and before spraying the paint stored in the storage pump by the coating machine, a paint of the paint color remaining in the insulating paint flow path is discharged by a cleaning fluid, and a flow path cleaning means for cleaning. It is composed of

[0004] As this type of electrostatic coating apparatus,
For example, there is one disclosed in JP-A-2-2885.
The electrostatic coating apparatus disclosed in Japanese Patent Application Laid-Open No. Hei 2-2885,
After the paint supplied from the paint supply means is temporarily stored in a spiral coil-shaped reservoir tube serving as a storage pump through an electrically insulating hose or the like serving as an insulating paint flow path, the paint in the electrically insulated hose is aired. By discharging and washing by the channel washing means such as the above, the paint supply means and the reservoir tube are electrically insulated by the electrically insulating hose.

Accordingly, when a high voltage is applied to the paint by the electrostatic coating machine, the high voltage at this time is prevented from leaking to the paint source by the electrically insulating hose. Then, the paint stored in the reservoir tube is extruded from the reservoir tube by air pressure and supplied to a coating machine, so that the coating machine sprays the coating material on the object to be coated.

[0006]

In the above-described prior art electrostatic coating apparatus, the paint stored in the reservoir tube is extruded and supplied to the coating machine side by air pressure. For this reason, when supplying paint to the coating machine,
It is not possible to accurately supply a certain amount of paint according to the coating conditions. As a result, there is a problem that the coating film becomes non-uniform and color unevenness or the like occurs on the painted surface, and the finish of the coating becomes poor.

[0007] Further, since the reservoir tube is formed in a spiral coil shape, the resistance when the paint flows is large, and in this respect, the paint cannot be stably supplied to the coating machine.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to paint a paint discharged from a storage pump while preventing high voltage leakage to a paint source side. It is an object of the present invention to provide an electrostatic coating apparatus capable of improving the finish of coating by supplying a fixed amount to a machine.

[0009]

According to the present invention, there is provided an electrostatic coating apparatus comprising: a paint supply means for supplying a paint of one color or a plurality of colors; and an insulating material having an upstream side connected to the paint supply means. A paint flow path, a storage pump provided at a downstream side of the insulating paint flow path, for temporarily storing paint supplied from the paint supply means, and discharging the paint, and a discharge side of the storage pump. The paint outflow passage provided in, and provided at the tip side of the paint outflow passage, atomized while applying a high voltage to the paint supplied from the storage pump,
A coating machine for spraying the charged paint charged at a high voltage toward the object to be coated, and the coating color remaining in the insulating paint flow path before the coating machine sprays the paint stored in the storage pump. And a flow path cleaning means for discharging the paint by the cleaning fluid and cleaning.

[0010] In order to solve the above-mentioned problems,
A feature of the configuration adopted by the invention according to claim 1 is that the storage type pump is provided with a cylinder, a piston that is slidably displaceable in the cylinder, and a piston that defines a paint chamber in the cylinder, and displaces the piston. An actuator for storing the paint in the paint chamber or discharging the paint in the paint chamber, and supplying the paint discharged from the storage pump to the paint machine in the paint outflow passage at a constant rate. That a mold pump is provided.

With this configuration, when painting is performed, the piston of the storage pump is displaced by the actuator of the storage type pump, and the paint is supplied to the paint chamber in the cylinder from the paint supply means via the insulating paint pipe. Fill with paint and store temporarily. Next, the piston of the storage pump is displaced by the actuator of the storage pump, and the paint in the paint chamber is discharged to the paint outflow passage, and the paint is filled in the paint outflow passage.

In addition, a cleaning fluid is supplied to the insulating paint flow path from the flow path cleaning means in parallel with the paint filling operation into the paint outflow passage or after the paint filling operation and before spraying the paint from the coating machine. Then, one paint remaining in the insulating paint flow path is discharged and washed. As a result, the interior of the insulating paint flow path becomes empty and becomes an insulator, so that the insulating paint flow path that has become an insulator forms a high-voltage interrupting section between the paint supply means and the storage pump.

When a high voltage cut-off portion is formed between the paint supply means and the storage pump, the paint in the paint chamber of the storage pump is sequentially supplied to the positive displacement pump through the paint outflow passage. Drive the pump. This allows
The paint is supplied to the coating machine at a constant flow rate according to the coating conditions by the positive displacement pump, and the coating machine sprays the coating material on the object.

When the paint is sprayed by the coating machine, a high voltage is applied to the paint sprayed from the coating machine in order to increase the efficiency of coating the paint on the object. In this case, the high voltage applied to the paint flows through the paint, but leakage to the paint supply means is prevented by the high voltage cut-off portion formed between the paint supply means and the storage pump. Thereby, the charging voltage of the paint can be maintained at a high state, and the charged paint can be efficiently applied to the object to be coated.

According to a second aspect of the present invention, in the storage pump, the discharge amount of the paint is set to be equal to or more than the discharge amount of the paint by the positive displacement pump. As a result, the paint can be sufficiently supplied from the storage pump to the displacement pump,
The paint supply shortage can be resolved, and the paint can be stably supplied from the positive displacement pump to the coating machine.

According to a third aspect of the present invention, the storage pump is configured to store an amount of paint required for painting one object to be coated in the paint chamber. Thereby, since most of the paint in the paint chamber is discharged by one coating, the resin and the pigment in the paint can be prevented from settling in the paint chamber. Further, the outer dimensions of the storage pump can be reduced.

According to a fourth aspect of the present invention, the positive displacement pump is configured as a flushable gear pump having a washing flow path for washing a shaft supporting a gear. Thereby, at the time of color change of the paint, it is possible to wash the pre-color paint adhered to the shaft supporting the gear and the like.

According to a fifth aspect of the present invention, in the coating machine, a tip cleaning passage made of an insulating material for discharging a cleaning fluid toward the front end side for cleaning the paint adhered to the front end side of the coating machine is provided, A cleaning fluid discharging means for discharging the cleaning fluid in the distal cleaning passage is connected to the distal cleaning passage.

With this configuration, at the time of color change of the paint, the pre-color paint adhered to the tip side of the coating machine can be washed by the washing fluid discharged from the tip washing passage. In addition, after the cleaning, the cleaning fluid in the distal end cleaning passage is discharged by the cleaning fluid discharging means, so that the distal cleaning passage becomes an insulator, so that high voltage leakage due to the cleaning fluid can be prevented.

According to a sixth aspect of the present invention, the paint supply means is constituted by a color change valve device that selects and supplies one paint from a plurality of colors of paint supplied from a paint source. The connection with the mold pump is made by one insulating paint flow path. This makes it easy to route the insulating paint flow path between the color changing valve device and the storage pump.

According to a seventh aspect of the present invention, the paint supply means comprises a paint valve for each color, and the paint valve and the storage pump are connected by an insulating paint flow path for each color. As a result, the paint flows through the dedicated insulating paint flow path for each color, so that even if a part of the previous color paint remains in the insulating paint flow path, it is possible to prevent color mixing with other color paints. it can.

According to the invention of claim 8, the paint supply means is constituted by a paint supply storage pump separate from the storage pump, and an insulating paint flow is provided between the paint supply storage pump and the storage pump. It is connected by road.

With this configuration, the paint supplied from the paint source is stored in the paint supply storage type pump, and the paint is transferred from the paint supply storage type pump to the coating machine side via the insulating paint flow path. To the storage pump. At this time, by discharging the paint with a high discharge pressure from the paint supply storage pump, the supply amount of the paint can be increased and the paint can be supplied to the coating pump on the coating machine in a short time. Further, when the supply amount of the paint is maintained at the same supply amount, the flow area of the insulating paint flow path can be reduced, and the paint remaining in the insulating paint flow path and the cleaning fluid required for cleaning can be reduced. Can be.

According to a ninth aspect of the present invention, the paint supply means comprises a first paint supply means and a second paint supply means for supplying a plurality of colors of paint, and the storage type pump comprises a first paint supply means. A first insulating paint passage connected to the means;
And a second storage pump connected to the second paint supply means by a second insulating paint flow path, and the paint outflow passage is provided with the first storage pump and the positive displacement pump. The first made of an insulating material for connection with the pump
And a second paint outflow passage made of an insulating material for connecting between the second storage type pump and the positive displacement pump, and the flow path cleaning means comprises:
The discharge and washing of the paint are performed by combining the insulating paint flow path and the second paint outflow passage, and the discharge and washing of the paint is performed by combining the second insulating paint flow path and the first paint outflow passage. Configuration.

With such a configuration, for example,
In the case of applying the paint on the first paint supply means side, first, one paint supplied from the first paint supply means via the first insulating paint pipe is filled into the first storage pump. And store temporarily. Next, before this one paint is sprayed from the coating machine, a cleaning fluid is supplied from the channel cleaning means to the first insulating paint flow path, and the one paint remaining in the first insulating paint flow path is supplied. Drain and wash. When the inside of the first insulating paint flow path is cleaned, the inside of the second paint outflow passage is also cleaned by the flow path cleaning means. Thereby, the inside of the first insulating paint flow path is emptied to form a high-voltage cut-off section between the first paint supply means and the first storage pump, and the inside of the second paint outflow passage is emptied. To form a high-voltage cutoff between the positive displacement pump and the second storage pump.

Then, a high voltage cut-off section is formed between the first paint supply means and the first storage pump, and a high voltage cut section is formed between the positive displacement pump and the second storage pump. Then, the paint in the first storage type pump is discharged to the first paint outflow passage, and supplied from the first paint outflow passage to the positive displacement pump. As a result, the paint is supplied to the painting machine at a constant flow rate according to the painting conditions by the positive displacement pump, and is sprayed from the painting machine onto the article to be coated in a state charged with a high voltage.

In this case, the high voltage applied to the paint flows through the paint, but the first paint is supplied by the high voltage cut-off portion formed between the first paint supply means and the first storage pump. Leakage to the supply means is prevented and the positive displacement pump and the second
The leakage to the second storage pump is prevented by the high voltage cut-off portion formed between the storage pump and the second storage pump.

Therefore, even when one paint supplied from the first paint supply means to the first storage pump is being applied by the coating machine, the second paint supply means is followed by the second storage pump. Can be supplied for use in painting. In particular, when a plurality of paints of the same color are prepared by the first paint supply means and the second paint supply means,
The same color paint can be continuously applied, and a preparation operation for supplying the next paint to the storage pump can be performed in parallel with the coating operation.

On the other hand, when the paint in the second storage pump is sprayed from the coating machine, the second insulating paint flow path is emptied and the second paint supply means and the second storage pump are used. The first paint outflow passage is evacuated to form a high voltage cutoff between the positive displacement pump and the first storage pump. Thus, when the paint supplied from the second paint supply means to the second storage pump is being applied by the coating machine, the paint is supplied between the first paint supply means and the first storage pump. Can be distributed.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an electrostatic coating apparatus according to an embodiment of the present invention will be described in detail with reference to FIGS.

First, FIGS. 1 to 3 show a first embodiment of the present invention. Reference numeral 1 denotes a rotary atomizing head-type static type as a coating machine for spraying a coating material onto an object to be coated (not shown). An electrostatic coating machine (hereinafter referred to as an electrostatic coating machine 1) includes a rotary atomizing head 2 which is located at the tip end side and sprays the coating material from the outer peripheral edge in an atomized state by centrifugal force. A paint tube 3 for discharging paint toward the rotary atomizing head 2;
A thinner tube 4 is provided as a tip cleaning passage for discharging a thinner serving as a cleaning fluid toward the distal end side and the rotary atomizing head 2. A paint valve (trigger) for supplying and stopping paint is provided in the paint tube 3. (Valve) 5 is provided.
A drain valve (dump valve) 6 is connected to the paint tube 3 and located upstream of the paint valve 5 and discharges a paint of a previous color remaining in a paint outlet hose 8 to be described later at the time of color change. I have.

Here, the valves 5, 6 and valves 13, 18, 31, 32, 35, 36, 37, 38, 4 described later.
2,43,44,46,49,50,51,52,5
Reference numerals 4, 55 and 56 are formed as pilot air type two-way valves (open / close valves), and form normally closed valves that open when pilot air is supplied, for example.

Reference numeral 7 denotes a high-voltage generator built in the electrostatic coating machine 1. The high-voltage generator 7 includes a power supply cable (not shown).
And the like, and converts the supplied voltage into a predetermined high voltage, and directly applies the high voltage to the paint flowing through the paint tube 3.

Reference numeral 8 denotes a paint outflow hose which is connected to the paint tube 3 of the electrostatic coating machine 1 and serves as a paint outflow passage.
The paint outflow hose 8 is connected to an intermediate pump unit 1 described later.
The paint discharged from 6 is supplied to the electrostatic coating machine 1 side, and the upstream side thereof is connected to a paint passage 14A of a manifold 14 described later.

Reference numeral 9 denotes a gear pump serving as a positive displacement pump provided in the middle of the paint outflow hose 8, and the gear pump 9 comprises:
The drive motor 10 is connected via an insulating shaft 11 to a drive motor 10 disposed in a later-described ground area E1. In the gear pump 9, a driving gear and a driven gear (both not shown) each supported by a shaft are arranged in mesh with each other, and the driving gear is connected to the insulating shaft 11. Further, the gear pump 9 is configured as a flushable gear pump having a washing passage 9A for washing paint adhered to an end face, a shaft, or the like of each gear by a thinner supplied from a thinner supply hose 47 described later. The gear pump 9 supplies the paint discharged from the intermediate pump unit 16 to the electrostatic coating machine 1 at a constant flow rate according to the coating conditions.

Reference numeral 12 denotes a bypass passage having both ends connected to the paint outflow hose 8 so as to straddle the gear pump 9, reference numeral 13 denotes a bypass valve provided in the middle of the bypass passage 12, and the bypass valve 13 is connected to the paint outflow hose 8. , Manifold 1
The valve is opened at the time of washing of 4 and the like, and is circulated by bypassing paint, air, and thinner of the previous color.

Reference numeral 14 denotes a manifold disposed on the discharge side of the intermediate pump unit 16, and a paint passage 14A is formed in the manifold 14. Reference numeral 15 denotes a manifold disposed on the filling side of the intermediate pump unit 16,
The manifold 15 has a paint passage 15A and a drain passage 15A.
B is formed.

Reference numeral 16 denotes an intermediate pump unit provided between the manifolds 14 and 15;
17N, drain valves 18A, 18B,... 18N, storage pumps 19A,
19B,... 19N, filling valves 31A, 31B,.
The discharge valves 32A, 32B,... 32N are roughly constituted.

.. 17N are paint passages 14A of the manifold 14 and paint passages 1 of the manifold 15.
A, B,... N color paint passages connected to 5A, 1
.., 18N are located on the side of the manifold 15 and are provided with a paint flow path 17A of A color, a paint flow path 17B of B color,
The drain valves 18A, 18B,... 18N are connected to the drain passage 15B of the manifold 15, respectively.

Reference numeral 19A denotes a storage pump for A color provided at an intermediate position of the paint passage 17A for A color, and 19B denotes a storage pump for B color provided at an intermediate position of the paint passage 17B for B color. , 19N denote storage pumps for N colors provided at intermediate positions of the paint flow passages 17N for N colors, respectively. And temporarily stores the paint, and discharges the stored paint.

Here, a specific configuration of the storage pump 19 will be described with reference to FIG. 2. The storage pump 19 includes a base plate 20 formed as a thick plate,
An opening side is provided with a large-diameter cylindrical cylinder 22 with a bottom attached to the base plate 20 via bolts 21, 21,..., And is provided in the cylinder 22 so as to be displaceable in the axial direction. A piston 24 which defines a paint chamber 23 and an air cylinder 25 which is attached to the bottom 22A of the cylinder 22 and serves as an actuator for displacing the piston 24 are roughly constituted.

The air cylinder 25 includes a small-diameter bottomed tubular tube 26 attached to the bottom 22 A of the cylinder 22, and a piston 27 inserted into the tube 26 so as to be axially displaceable. , One end of the piston 27
And a piston rod 28 whose other end extends axially through the bottom 22A of the cylinder 22 and is connected to a piston 24 in the cylinder 22. An air chamber 29 on the 28 side and an air chamber 30 on the bottom 26A side are defined.

The base plate 20 has a paint chamber 23
, A filling passage 20A and a discharge passage 20B are formed, and the filling passage 20A is connected to filling valves 31A, 31B,.
, 17N are connected to the paint flow passages 17A, 17B,. Further, the discharge passage 20B is connected to the discharge valves 32A, 32
2B,... 32N. Further, in the tube 26 of the air cylinder 25, air passages 26B and 26C are formed at both ends in the axial direction.
B and 26C are connected to an air source (neither is shown) via an air valve.

The storage pump 19 having the above-described structure is configured such that the working air a is supplied from the air passage 26B to the air chamber 29 in the tube 26, whereby the piston 2
7 is moved in the retreating direction shown by the arrow (a), and the piston 24 connected to the piston 27 via the piston rod 28 is moved together in the retreating direction. Thus, the paint is filled and stored in the paint chamber 23 from the filling passage 20A of the base plate 20. Here, the paint chamber 23 is set to have a size capable of storing an amount of paint necessary for painting one object to be coated.

On the other hand, when the working air b is supplied to the air chamber 30 from the air passage 26C, the piston 27 moves the piston 24 in the forward direction indicated by the arrow (b). Thus, the paint stored in the paint chamber 23 is discharged from the discharge passage 20 </ b> B of the base plate 20 and supplied to the gear pump 9 via the paint outflow hose 8.

The discharge amount Q1 of the storage type pump 19 is set to the following expression 1 with respect to the discharge amount Q2 of the gear pump 9;
It is set to be equal to or slightly larger than 2.

[0047]

[Equation 1] Q1 ≧ Q2

Thus, the storage type pump 19 supplies the paint sufficiently to the gear pump 9 to prevent a shortage of the paint supply.

31N are filling valves connected between the filling passage 20A of the storage pumps 19A, 19B,... 19N and the paint flow passages 17A, 17B,. , ... 31N are the paint chambers 23
The valve is opened when the interior is filled with paint.

32N are discharge valves connected to the discharge passage 20B of the storage pumps 19A, 19B,... 19N, and the discharge valves 32A, 32B,.
Opens when the paint is discharged from the paint chamber 23.

Reference numeral 33 denotes a paint hose as an insulating paint passage formed in a tubular shape from a material having high electrical insulation, low moisture absorption and surface tension, for example, an insulating resin material such as polytetrafluoroethylene or nylon. Paint hose 3
Reference numeral 3 denotes an upstream side connected to a gate valve 38 of a color changing valve device 34 described later, and a downstream side connected to a paint passage 15A of the manifold 15. And the paint hose 33 is
The paint and thinner are discharged from the inside thereof, and when they are washed and emptied, they become insulators and exhibit high electrical insulation.

Numeral 34 denotes a color change valve device as a paint supply means connected to the upstream side of the paint hose 33.
Reference numeral 4 denotes an A color paint valve 35A, a B color paint valve 35B, an N color paint valve 35N, an air valve 36, a thinner valve 37, and a gate valve 38 serving as flow path cleaning means. 3
6, 37, and 38, which are collectively mounted. The manifold 39 has a paint passage 39 for communicating the valves 35, 36, 37, and 38 with each other.
A is formed. The paint valve 35A is an A color paint source for supplying the A color paint under pressure, the paint valve 35B is a B color paint source for supplying the B color paint, and the paint valve 35N is an N color paint for supplying the N color paint. (Not shown).

The color changing valve device 34 is provided with a color A, a color B,
... An arbitrary paint is supplied to the intermediate pump unit 16 by selecting and opening the paint valve 35 of any paint color among the N paints. In addition, at the time of color change, the air valve 36 and the thinner valve 37 serving as the flow path cleaning means are opened to discharge the paint remaining in the manifold 39, the paint hose 33, and the like, for cleaning.

Reference numeral 40 denotes a drain passage 15B of the manifold 15.
The drain hose 40 is formed of the same insulating resin material as the paint hose 33,
The downstream side is connected to a waste liquid tank (not shown).

Reference numeral 41 denotes a thinner hose connected to the thinner tube 4 for supplying thinner to the thinner tube 4 of the electrostatic coating machine 1. The thinner hose 41 forms a leading end cleaning passage together with the thinner tube 4. ing. The thinner hose 41 is formed of the same insulating resin material as the paint hose 33, and the upstream side thereof is connected to a thinner source (not shown) for supplying thinner under pressure.

On the upstream side of the thinner hose 41, a thinner valve 42 for supplying and stopping the thinner to the electrostatic coating machine 1 is provided.
In the middle of the thinner hose 41, a cleaning gate valve 43 for supplying and stopping the thinner in the same manner as the thinner valve 42 is provided.
Is provided. Further, an air valve 44 serving as a cleaning fluid discharging means is provided upstream of the thinner hose 41, and the air valve 44 is connected to an air source (not shown) for supplying compressed air. This is for supplying and stopping air for discharging the thinner in the inside.

A drain hose 45 is located near the upstream side of the cleaning gate valve 43 and connected to the thinner hose 41. The drain hose 45 is formed of the same insulating resin material as the paint hose 33. ing. The drain hose 45 discharges the thinner in the thinner hose 41 to the waste liquid tank by air from the air valve 44, and a drain valve 46 is provided in the middle thereof.

Reference numeral 47 denotes a thinner supply hose connected to the inlet side of the washing passage 9A for supplying thinner to the washing passage 9A of the gear pump 9.
It is formed of the same insulating resin material as the paint hose 33, and its upstream side is connected to a thinner source. Also, 4
Reference numeral 8 denotes a thinner discharge hose connected to the outlet side of the cleaning passage 9A for discharging the thinner flowing out of the cleaning passage 9A to a waste liquid tank. The thinner discharge hose 48 is made of the same insulating resin as the paint hose 33. It is formed of a material.

On the upstream side of the thinner supply hose 47, a thinner valve 49 for supplying and stopping the thinner to the gear pump 9 and an air for discharging the thinner in the thinner supply hose 47 and the thinner discharge hose 48 are provided. An air valve 50 for supplying and stopping is provided. A cleaning gate valve 51 is provided in the thinner supply hose 47, and a thinner discharge valve 52 is provided in the thinner discharge hose 48.

Reference numeral 53 denotes a paint passage 14A of the manifold 14.
To supply air and thinner to the manifold.
The air thinner hose 53 is formed of the same insulating resin material as the paint hose 33, and the upstream side thereof is connected to an air source and a thinner source. On the upstream side of the air thinner hose 53, an air valve 54 for supplying and stopping air supplied from an air source and a thinner valve 55 for supplying and stopping thinner supplied from a thinner source are provided.・ Thinner hose 53
A washing gate valve 56 is provided on the downstream side.

Reference numeral 57 denotes a drain hose connected to the drain valve 6 of the electrostatic coating machine 1.
The waste paint and thinner are discharged into the waste liquid tank by the air supplied from the air valve 54.

The electrostatic coating apparatus according to the present embodiment has the above-described configuration. Next, the operation thereof will be described in detail with reference to the time characteristic diagram shown in FIG.

First, as an operation for applying the color A paint, a preparation operation until the paint tube 3 is filled with the color A paint will be described.

First, in the preparation operation for painting the A color paint,
As a first step, there is an operation of filling and storing the A-color paint in the storage pump 19A. In this case, the color changing valve device 34
The paint valve 35A, the gate valve 38, and the filling valve 31A of the A color are opened, and the working air a is supplied to the air chamber 29 of the storage pump 19A. Thereby, the storage pump 19A
Moves in the retreating direction shown by the arrow (a),
An A-color paint supplied from the A-color paint source through a paint hose 33 and a paint flow passage 17A is filled into the paint chamber 23 and temporarily stored therein.

Next, as a second stage, there is a cleaning operation of the paint hose 33 and a filling operation of the A color paint on the electrostatic coating machine 1 side. In this case, by opening the gate valve 38 and the drain valve 18A, and alternately opening the thinner valve 37 and the air valve 36, the thinner and the air are supplied under pressure and the paint hose 33 is opened.
The A-color paint remaining inside is drained from the drain hose 40 to the waste tank, and the paint hose 33 and the drain hose 40 are cleaned and emptied. As a result, the paint hose 33 and the drain hose 40 are used as insulators, and a high voltage cut-off section E3 (line O1-O1 and line O2) to be described later for cutting off high voltage from the electrostatic coating machine 1.
(The range between -O2).

When cleaning the paint hose 33,
The discharge valve 32A and the paint valve 5 are opened, and the storage pump 19A is opened.
In addition to supplying the working air b to the air chamber 30, the gear pump 9 is driven by the drive motor 10. This allows
The A-color paint in the paint chamber 23 is discharged by the piston 24 moving in the forward direction shown by the arrow (b), and is supplied from the paint outflow hose 8 to the gear pump 9. The paint of the color A supplied to the gear pump 9 is filled into the paint tube 3 from the gear pump 9, and a part of the paint is discarded and blown from the paint tube 3.

Next, as a third step, there is an operation of washing the paint of A color thrown away from the paint tube 3. In this case, the thinner supplied from the thinner source is first discharged from the thinner hose 41 and the thinner tube 4 toward the tip of the paint tube 3 and the rotary atomizing head 2 by opening the thinner valve 42 and the cleaning gate valve 43. Then, the paint of A color attached to the tip of the paint tube 3 and the rotary atomizing head 2 is washed.
After cleaning the tip of the paint tube 3 and the rotary atomizing head 2 in this manner, the air valve 44 and the drain valve 46 are opened, and thinner remaining in the thinner hose 41 is discharged from the drain hose 45 to the waste tank. After discharging, the thinner hose 41 and the drainage hose 45 are emptied to form a part of the high-voltage interrupting section E3.

The thinner supply hose 47, the thinner discharge hose 48, the air thinner hose 53, and the drain hose 57
Are empty before the filling operation of the A-color paint, and each of them forms a part of the high-voltage interrupting portion E3.

Here, the color changing valve device 34, the thinner valve 42,
49, 55, and the air valves 44, 50, 54 are connected to a grounded ground region E1 (region on the right side of the line O1-O1 in FIG. 1).
It is arranged in. Further, the electrostatic coating machine 1, the gear pump 9, the bypass valve 13, the intermediate pump unit 16, the cleaning gate valves 43, 51, 56, the drain valve 46, the thinner discharge valve 5
Reference numeral 2 denotes a high-voltage charging area E2 (area on the left side of the line O2-O2 in FIG. 1) which is charged to a high voltage when a high voltage is applied to the paint by the high-voltage generator 7. .

On the other hand, between the line O1-O1 and the line O2-O2, a paint hose 33 made of an insulating resin material, drain hoses 40, 45, 57, thinner hose 41, thinner supply hose 47, thinner discharge hose 48 , Air thinner hose 53, the paint hose 33,
The paints and thinners in the drainage hoses 40, 45, 57, thinner hose 41, thinner supply hose 47, thinner discharge hose 48, and air thinner hose 53 are discharged, washed, and emptied, so that the lines O1 -O1 are drawn. High voltage cut-off section E for cutting off the high voltage from high voltage generator 7 between O2 and O2.
3 can be formed.

Next, a description will be given of a painting operation when the A-color paint is sprayed toward the object to be coated. In this case, the discharge valve 32A is opened, and the working air b is supplied to the air chamber 30 of the storage pump 19A. Then, the paint valve 5 is opened and closed according to the shape of the object to be coated, and the gear pump 9 is driven in accordance with the opening and closing. Thus, the A-color paint is discharged from the paint tube 3 to the rotary atomizing head 2 and sprayed from the rotary atomizing head 2 toward the object to be coated. At this time, since the paint at a flow rate according to the coating conditions can be supplied quantitatively from the gear pump 9 serving as a positive displacement pump, a coating film formed by this coating can be formed uniformly.

At the time of this coating, a high voltage is applied to the paint flowing through the paint tube 3 by the high voltage generator 7 and the paint sprayed from the rotary atomizing head 2 is used as the charged paint. By flying toward the object connected to the ground, the paint application efficiency is improved.

At this time, in the present embodiment, the paint hose 33, the drain hoses 40, 45, 57, and the thinner hose 4 located between the line O1-O1 and the line O2-O2 in FIG.
1. A high voltage cut-off portion E3 is formed in the thinner supply hose 47, the thinner discharge hose 48, and the air thinner hose 53. For this reason, the high voltage applied to the paint from the high voltage generator 7 is cut off by the high voltage cut-off section E3, so that the high voltage applied to the paint source side and the thinner source side of each color arranged in the earth area E1 is reduced. Voltage leakage can be prevented.

Next, in applying the B color paint, A
The color changing operation when changing the color from the color paint to the B color paint will be described.

First, as a first stage, A which is a paint of a previous color is used.
There is an operation to discharge and wash color paint. At the time of this A color paint washing operation, the washing gate valve 56, the bypass valve 13,
The drain valve 6 is opened, and the air valve 54 and the thinner valve 55 are opened.
Are alternately opened. Thereby, the air thinner supplied from the air source and the thinner source is supplied to the air thinner hose 53,
Paint passage 14A of manifold 14, paint outflow hose 8
The A color paint remaining inside these is discharged from a drain hose 57 to a waste tank and washed. Also,
At the time of the washing operation of the A-color paint, the A-color paint remaining in the paint tube 3 is discharged and washed by temporarily opening the paint valve 5.

Further, the gear pump 9 is driven to discharge and wash the color A paint adhered to the gears, passages and the like of the gear pump 9. At this time, the thinner valve 49 and the cleaning gate valve 5
1. The thinner discharge valve 52 is opened and the thinner supply hose 47 is opened.
Supplies thinner to the washing passage 9A of the gear pump 9, and discharges the A-color paint adhered to the end faces, shafts and the like of the gears of the gear pump 9 to wash it.

After the paint tube 3, the paint outflow hose 8, the gear pump 9, and the manifold 14 have been washed in this way, the air valve 54 is finally opened, whereby the air thinner hose 53 and the paint passage 14 of the manifold 14 are opened.
A, the thinners in the bypass passage 12, the paint outflow hose 8, and the drain hose 57 are discharged, and the insides thereof are emptied. After cleaning the end faces, shafts, and the like of the gears of the gear pump 9, the air valve 50 is finally opened to discharge the thinner in the cleaning passage 9A, the thinner supply hose 47, and the thinner discharge hose 48 of the gear pump 9. And empty these interiors.

On the other hand, during the above-described washing operation of the A-color paint, the B-color paint, which is the next color paint, is supplied to the storage pump 19B.
Are performed in parallel. During the operation of storing the B color paint, the B color paint valve 35 of the color changing valve device 34 is operated.
B, the gate valve 38 and the filling valve 31B are opened, and the operating air a is supplied to the air chamber 29 of the storage type pump 19B to move the piston 24 in the retreating direction. 33, the paint chamber 23 is filled with the paint of B color which is supplied under pressure via the paint flow passage 17B.

When the B type paint is filled in the storage type pump 19B, the gate valve 38 and the drain valve 18B are opened, and the thinner valve 37 and the air valve 36 are opened alternately. As a result, the B color paint remaining in the paint hose 33 and the manifolds 15 and 39 is discharged to the waste liquid tank via the drain hose 40 by the thinner and the air, and is washed.

As described above, the paint hose 33 and the manifolds 15 and 3 located on the upstream side of the intermediate pump unit 16
After cleaning the nozzle 9, the thinner in the paint hose 33, the paint passages 15A and 39A of the manifolds 15 and 39, the drain passage 15B, and the drain hose 40 is discharged by opening the air valve 36. Empty the interior.

Next, as a second stage, there is an operation of filling the electrostatic coating machine 1 with the B color paint. In this case, the discharge valve 32
B, the paint valve 5 is opened, and the air chamber 3 of the storage pump 19B is opened.
0 and the gear pump 9 is driven. Thereby, the B color paint in the paint chamber 23 is supplied from the paint outflow hose 8 to the gear pump 9. The B color paint supplied to the gear pump 9 is filled into the paint tube 3 from the gear pump 9, and a part of the paint is discarded and blown from the paint tube 3.

Next, as a third step, there is an operation of washing the B color paint thrown away from the paint tube 3. In this case, first, the thinner valve 42 and the cleaning gate valve 43 are opened, and the thinner is discharged from the thinner hose 41 and the thinner tube 4 toward the tip of the paint tube 3 and the rotary atomizing head 2,
The B color paint adhered to the tip of the paint tube 3 and the rotary atomizing head 2 is washed.

After the tip of the paint tube 3 and the rotary atomizing head 2 have been cleaned, the thinner remaining in the thinner hose 41 is removed from the drain hose 45 by opening the air valve 44 and the drain valve 46. Discharge and empty the interior.

Thus, the paint hose 33 made of an insulating resin material, the drain hoses 40, 45, 57, the thinner hose 41, the thinner supply hose 47, and the thinner discharge hose 4
8. By emptying the air thinner hose 53,
The high-voltage interrupting portion E3 can be formed with high insulation in the range between the line O1-O1 and the line O2-O2.

When the paint of the B color is filled in the paint tube 3 in this manner, the paint of the B color is supplied in a fixed amount by the gear pump 9 in the same manner as the painting operation of the A color paint.
As a result, the B color paint is discharged from the paint tube 3 toward the rotary atomizing head 2 of the electrostatic coating machine 1, and the B color paint is sprayed on the object to be coated. Then, the high voltage applied to the paint at this time is reliably cut off by the high voltage cut-off section E3 and does not leak to the earth region E1.

Therefore, according to the present embodiment, the paint discharged from the storage type pump 19 is supplied to the electrostatic coating machine 1 side by using the gear pump 9 serving as a positive displacement type pump. Paint can be supplied to the electrostatic coating machine 1 accurately and quantitatively according to the flow rate, so that the coating can be uniform and the coating finish can be improved, and the reliability of the electrostatic coating device can be improved. Can be.

The storage type pump 19 is connected to the cylinder 22.
A piston 2 defining a paint chamber 23 in the cylinder 22
4. Since the piston 24 is constituted by an air cylinder 25 or the like for displacing the piston 24 in the axial direction, the paint is stably filled and stored in the paint chamber 23 by supplying / discharging air to / from the air cylinder 25 and discharged. In this respect, the coating finish can be improved.

Further, since the discharge amount Q1 of the storage type pump 19 is set to be equal to or slightly larger than the discharge amount Q2 of the gear pump 9, it is possible to prevent the supply of paint to the gear pump 9 from being insufficient. Thus, the paint can be stably supplied to the electrostatic coating machine 1.

The paint chamber 23 of the storage pump 19 is
The size of the storage pump 19 can be reduced to a necessary minimum because the size is set to be able to store an amount of paint necessary for painting one object to be coated. Can be reduced in size.

Further, since the gear pump 9 is configured as a flushable gear pump having a washing passage 9A for washing the paint adhered to the end faces, shafts, and the like of the built-in gears, the paint of the previous color is thoroughly washed. Thus, it is possible to prevent the occurrence of coating failure due to color mixing with the residual paint.

Further, a thinner tube 4 and a thinner hose 41 are provided in the electrostatic coating machine 1 as a tip cleaning passage, and the rotary atomizing head 2 and
Since the paint adhering to the tip of the paint tube 3 can be washed, coating failure due to color mixing can be prevented. In addition, since the thinner hose 41 for supplying the thinner to the thinner tube 4 is connected to the air valve 44 serving as a cleaning fluid discharging means, the air supplied from the air valve 44 empties the thinner hose 41 after the tip cleaning. To cut off high voltage.

On the other hand, the paint supply means is constituted by the color changing valve device 34, and the color changing valve device 34 and the intermediate pump unit 16 are connected by one paint hose 33. It can be easily performed, and the assembling workability can be improved.

FIGS. 4 and 5 show a second embodiment of the present invention. The feature of this embodiment is that the paint supply means is constituted by a paint valve for each color. And the storage pump are connected by using a dedicated paint hose for each color. Note that, in the present embodiment, the first
The same reference numerals are given to the same components as those of the embodiment, and the description thereof will be omitted.

61N are paint hoses for each color forming an insulating paint flow path according to the present embodiment, which are used in place of the paint hose 33 according to the first embodiment.
The paint hoses 61A, 61B,... 61N are made of a material having high electrical insulation, low hygroscopicity and surface tension, for example, an insulating resin material such as polytetrafluoroethylene, nylon or the like, like the paint hose 33. Is formed. And paint hoses 61A, 61B, ... 61N
The paint valves 62A, 62B,... 62N of the colors A, B,..., N described later on the upstream side, and the paint flow passages 17A, 17B,.
17N.

62N are paint hoses 6A.
, N are paint valves provided on the upstream side of 1A, 61B,... 61N as paint supply means, and the paint valves 62A, 62B,.
1 (a range on the right side of the line O1-O1), the paint valve 62A is a paint source of A color, the paint valve 62B is a paint source of B color,
The paint valve 62N is connected to an N-color paint source.

63N are ground areas E.
The gate valves 63A, 63B,... 6 are connected to the paint hoses 61A, 61B,.
3N is connected to the air thinner passage 64A of the manifold 64. Further, the manifold 64 is connected to an air valve 65 and a thinner valve 66 serving as a flow path cleaning means in the air thinner passage 64A.

67N are drain hoses for each color connected to the drain valves 18A, 18B,... 18N of the intermediate pump unit 16. The drain hoses 67A, 67B,.
67N are formed of the same insulating resin material as the paint hose 61, and are connected to a waste liquid tank disposed in the ground area E1.

The electrostatic coating apparatus according to the present embodiment has the above-described configuration, and its operation is as shown in a time characteristic diagram shown in FIG. 5, and is shown in FIG. 3 according to the first embodiment. There is no significant difference from the time characteristic diagram shown.

However, in the present embodiment, the paint hoses 61A, 61B,.
A, 67B,... 67N are provided. Therefore, the operation differs from the first embodiment in that the gate valves 63A, 63B,.
61B,... Paints in the air valve 65, thinner valve 66
This is a point that the valve is opened only when the air supplied from the air is exhausted by the thinner and is washed.

Thus, in the present embodiment, the paint hoses 61A, 61B,.
A, 67B,... 67N are provided, for example, even if paint remains in the paint hoses 61A, 61B,. Can be.

FIGS. 6 to 8 show a third embodiment of the present invention. The feature of this embodiment is that the paint supply means is constituted by a paint supply storage pump. In the present 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.

.. 71N are paint hoses for each color forming an insulating paint flow path according to the present embodiment, which are used in place of the paint hose 33 according to the first embodiment.
The paint hoses 71A, 71B,... 71N are made of a material having high electrical insulation, low hygroscopicity and surface tension, for example, an insulating resin material such as polytetrafluoroethylene, nylon, or the like. Is formed. Also, paint hoses 71A, 71B,...
71N, the upstream side is connected to a later-described paint supply storage type pump 72A, 72B,... 72N, and the downstream side is a paint flow passage 17A, 17B,
... 17N. However, the pipe diameters of the paint hoses 71A, 71B,... 71N according to the present embodiment are set to be smaller than the pipe diameter of the paint hose 33 according to the first embodiment.

72A, 72A, 72B,...
.. 74N, which are provided separately from the storage type pump 19 according to this embodiment, and connected to the paint hoses 71A, 71B,... 71N via discharge valves 74A, 74B,. , N-color paint supply storage pump, and the paint supply storage pump 72
A, 72B,... 72N are configured in the same manner as the storage type pump 19 according to the first embodiment, and are disposed in a grounded ground area E1 (range rightward from the line O1-O1). Further, the paint supply storage pumps 72A, 72B,.
72N are connected to paint sources of A, B,..., N colors.

In the paint supply storage pump 72 according to the present embodiment, the working air b supplied when the paint is discharged has a higher pressure than the supply pressure when the paint is supplied from the paint source. Is set to

73N are filling valves connected to the filling sides of the paint supply storage pumps 72A, 72B,... 72N. The filling valve 73 supplies the paint into the paint supply storage pump 72. The valve opens when filling.

74N are discharge valves connected to the discharge sides of the paint supply storage pumps 72A, 72B,... 72N. The discharge valve 74 is provided by the paint supply storage pump 72. The valve is opened when the liquid is discharged.

.. 75N are ground areas E.
.. 71N and the gate valves 75A, 75B,.
5N is connected to an air thinner passage 76A of the manifold 76. Further, the manifold 76 is connected to an air valve 77 and a thinner valve 78 serving as flow path cleaning means in the air thinner passage 76A.

79N are drainage hoses for each color connected to the drainage valves 18A, 18B,... 18N of the intermediate pump unit 16. The drainage hoses 79A, 79B,.
79N are formed of the same insulating resin material as the paint hose 71, and are connected to a waste liquid tank disposed in the ground area E1.

The electrostatic coating apparatus according to the present embodiment has the above-described configuration, and its operation is as shown in the time characteristic diagram shown in FIG. 7, and is shown in FIG. 3 according to the first embodiment. There is no significant difference from the time characteristic diagram shown.

In this embodiment, however, the paint hoses 71A, 71B,...
, 79N, and the paint hose 71A,
.. 71B, upstream of 71N,...
2A, 72B,... 72N, filling valves 73A, 73B,.
3N, and discharge valves 74A, 74B,... 74N are provided. Therefore, the operation differs from the first embodiment in the primary storage operation and the secondary storage operation of the paint in the paint application preparation operation.

Therefore, using the time characteristic diagram shown in FIG.
The primary storage operation of the paint in the preparation operation for painting the A color paint,
The secondary storage operation will be described.

First, when filling (primary storage) the paint of color A into the paint supply storage pump 72A as the first stage, the filling valve 73A is opened and the paint supply storage pump 72A is operated. Supply air a. Thus, A
The paint of color A, which is supplied under pressure from a paint source of color, is filled in the paint supply storage pump 72A.

Next, as the second stage, the filling of the A color paint stored in the paint supply storage pump 72A into the storage pump 19A of the intermediate pump unit 16 (secondary storage) requires the discharge valve 74A, The filling valve 31A is opened, the working air b is supplied to the paint supply storage pump 72A, and the working air a is supplied to the storage pump 19A. As a result, the A-color paint in the paint supply storage pump 72A is filled into the storage pump 19A on the electrostatic coating machine 1 side through the paint hose 71A.

Although the pipe diameter of the paint hose 71A is set to be small, the paint supply storage pump 7
Since the pressure of the operating air b for discharging the paint from 2A is set to a high pressure, A in the paint supply storage type pump 72A is
The color paint can be supplied to the storage pump 19A in a short time.

When the color change from the A color paint to the B color paint is performed, the primary storage operation of the B color paint is performed in parallel with the application of the A color paint, and the secondary storage operation of the B color paint is performed. This is performed as the first stage of the replacement operation. Thus, the color change operation can be performed in the same operation time as in the first embodiment.

Thus, according to the present embodiment, since the paint hoses 71A, 71B,... 71N are provided for each color, for example, the paint hoses 71A, 71B,.
Even when the paint remains in the 71N, it is possible to prevent color mixing with another color paint and to prevent the occurrence of coating failure.

Further, in the present embodiment, the paint hose 7
, 72N is provided upstream of 1A, 71B,... 71N, and is directed from the paint supply storage pumps 72A, 72B,... 72N to the storage pumps 19A, 19B,. The working air b for discharging the paint is set to a high pressure. This allows
Even when the pipe diameter of the paint hose 71 is set to a small diameter,
The paint can be supplied to the storage pump 19 in a short time, and workability at the time of supplying the paint can be improved. Furthermore, by reducing the diameter of the paint hose 71, paint remaining in the paint hose 71 can be reduced, and the amount of thinner required for cleaning and the cleaning time can be reduced, so that productivity is improved and running costs are reduced. Can be achieved.

FIGS. 9 to 12 show a fourth embodiment of the present invention. The feature of this embodiment is that first and second paint supply means for supplying paints of a plurality of colors are provided. 1st, 2nd
Is provided, and the paint is selectively supplied from the first and second storage pumps to the positive displacement pump. In the present embodiment, the same components as those in the first embodiment are given the same reference numerals,
The description is omitted.

Reference numeral 81 denotes a paint outflow hose forming a paint outflow passage according to the present embodiment, which is used in place of the paint outflow hose 8 according to the first embodiment.
1 is a paint tube 3 of the electrostatic coating machine 1 located on the downstream side.
Hose section 81A connected to the
It is composed of a first branch hose portion 81B and a second branch hose portion 81C which are provided by bifurcating the upstream side of 1A. The branch hose portions 81B and 81C are
Like the paint hose 33 according to the first embodiment, it is formed of an insulating resin material.

Further, a gate valve 82 is provided in the middle of the first branch hose portion 81B in a high-voltage charging area E5 described later, and on the upstream side of the gate valve 82, the high-voltage charging area E5 is provided. And the drain valve 83 is connected. A drain hose 84 formed of an insulating resin material is connected to the drain valve 83, and the drain hose 84 is connected to a waste tank (not shown) disposed in a later-described ground area E4.
It is connected to the. And the first branch hose 81B,
The drain hose 84 forms a third high-voltage interrupting section E8 to be described later by discharging and washing the paint and thinner inside.

On the other hand, as shown in FIG. 10, a gate valve 85 is provided in the middle of the second branch hose section 81C in the high voltage charging area E5. The drain valve 86 is connected to the charging area E5. A drain hose 87 formed of an insulating resin material is connected to the drain valve 86.
Is a waste liquid tank (not shown) disposed in the ground area E4
It is connected to the. And the second branch hose 81C,
The drainage hose 87 forms a fourth high-voltage cutoff section E11 described later by discharging and washing the paint and thinner inside.

Reference numeral 88 denotes a manifold provided on the upstream side of the first branch hose portion 81B, and a paint passage 88A is formed in the manifold 88.

Reference numeral 89 denotes a first intermediate pump unit provided on the upstream side of the manifold 88. The first intermediate pump unit 89 is the same as the intermediate pump unit 16 according to the first embodiment. , B color,... N color paint flow passages 90A, 90B,.
B,... 91N, first storage pumps 92A, 92B,.
92N, filling valves 93A, 93B,... 93N, discharge valve 94
A, 94B,... 94N.

.., 95N are paint flow passages 9
, 90A, and 90N, a first paint hose for each color forming a first insulating paint flow path.
Reference numeral 5 is formed of an insulating resin material similarly to the paint hose 33 according to the first embodiment.

.. 96N are paint hoses 9A, 9B,.
The first paint valves of colors A, B,..., N serving as first paint supply means provided on the upstream side of 5A, 95B,... 95N, and the paint valves 96A, 96B,. The paint valve 96A is connected to a paint source of A color, the paint valve 96B is connected to a paint source of B color, and the paint valve 96N is connected to a paint source of N color.

.. 97N are ground areas E.
The gate valves 97A, 97B,... 9 connected to the paint hoses 95A, 95B,.
7N is connected to the air thinner passage 98A of the manifold 98. Further, the manifold 98 is connected to an air valve 99 and a thinner valve 100 serving as a flow path cleaning means in the air thinner passage 98A.

101N are drain valves 91A, 91B,... 9 of the first intermediate pump unit 89.
The drain hoses 101A, 101B,... 101N are formed of the same insulating resin material as the paint hose 33 according to the first embodiment.

Reference numeral 102 denotes a paint passage 88 of the manifold 88.
A is an air thinner hose connected to A. The air thinner hose 102 is a paint hose 3 according to the first embodiment.
3 is formed of the same insulating resin material, and its upstream side is connected to an air source and a thinner source. In addition, air
An air valve 103 and a thinner valve 104 are provided on the upstream side of the thinner hose 102, and a cleaning gate valve 105 is provided on the downstream side.

Reference numeral 106 denotes a manifold provided on the upstream side of the second branch hose portion 81C of the paint outflow hose 81.
A paint passage 106A is formed in the manifold 106.

Reference numeral 107 denotes a second intermediate pump unit provided on the upstream side of the manifold 106. The second intermediate pump unit 107 has the same colors as A, B, ... N-color paint flow passage 108
A, 108B,... 108N, drainage valves 109A, 109
B,... 109N, second storage pump 110A, 110
.. 110N, filling valves 111A, 111B,.
N, and discharge valves 112A, 112B,... 112N.

.. 113N are the second paint passages 108A, 108B,.
In the second paint hose for each color forming the insulating paint flow path, the paint hose 113 is formed of an insulating resin material, similarly to the paint hose 33 according to the first embodiment.

.. 114N are second paint valves of colors A, B,... N serving as second paint supply means provided upstream of the paint hoses 113A, 113B,. The paint valves 114A, 114B,... 114
N is disposed in the ground area E4, and the paint valve 114A is
Color paint source, paint valve 114B is B color paint source, paint valve 1
14N is connected to an N-color paint source, and the first paint valve 96
A, 96B,... 96N are supplied with the same color paint.

115N are located in the ground area E4 and the paint hoses 113A, 113B,.
A gate valve connected to the gate valve 113N;
, 115N are connected to the air thinner passage 116A of the manifold 116. The manifold 116 is connected to an air valve 117 and a thinner valve 118 serving as a flow path cleaning means in the air thinner passage 116A.

.. 119N are drain valves 109A, 109 of the second intermediate pump unit 107.
B,... 109N are drain hoses for each color, and the drain hoses 119 are formed of the same insulating resin material as the paint hose 33 according to the first embodiment.

Reference numeral 120 denotes the paint passage 1 of the manifold 106.
The air thinner hose 120 is formed of the same insulating resin material as the paint hose 33 according to the first embodiment, and the upstream side thereof is connected to an air source and a thinner source. ing. An air valve 121 and a thinner valve 122 are provided on the upstream side of the air thinner hose 120, and a cleaning gate valve 123 is provided on the downstream side.

Here, in the present embodiment, FIGS.
The area on the right side of the line O1 -O1 shown in FIG. 3 is a grounded ground area E4, which includes first paint valves 96A, 96B,... 96N and second paint valves 114A, 114A.
.. 114N, gate valves 97A, 97B,.
N, 115A, 115B,... 115N, air valves 99, 1
03, 44, 50, 117, 121, thinner valve 100,
104, 42, 49, 118 and 122 are provided. The area on the left side of the line O2-O2 is the high voltage generator 7
When the paint is charged with a high voltage, the high voltage charging area E5 is charged to the high voltage. The high voltage charging area E5 includes gate valves 82 and 85, drain valves 83 and 86,
The gear pump 9, the electrostatic coating machine 1 and the like are provided.

Further, a region between the line O3 -O3 and the line O4 -O4 is a switching region E6 for switching between a ground region and a high voltage charging region. When the first high-voltage interrupting portion E7 is formed between the lines O1 -O1 and O3 -O3, it becomes a high-voltage charging area, and the first branch hose portion 81B and the like of the paint outflow hose 81 are cleaned. A ground region is formed when a third high-voltage interrupting portion E8 is formed between the line O2-O2 and the line O4-O4, and a first intermediate pump unit 89 and the like are provided.

The area between the line O5-O5 and the line O6-O6 is a switching area E9 for switching between the earth area and the high voltage charging area.
13 is cleaned to form a high-voltage charging area when the second high-voltage interrupting section E10 is formed between the lines O1-O1 and O5-O5, and the second branch hose section 81C of the paint outflow hose 81 is formed. Are grounded when the fourth high-voltage interrupting section E11 is formed between the lines O2 -O2 and O6 -O6 after being cleaned, and the second intermediate pump unit 107 is provided. Have been.

The electrostatic coating apparatus according to the present embodiment has the above-described configuration, and its basic operation is almost the same as that according to the first embodiment.

However, in the present embodiment, the fork is branched into two branches upstream of the paint outflow hose 81, and the first intermediate pump unit 89, the first paint hose 95, and the first paint valve 96 are provided on the upstream side. And the second intermediate pump unit 107, the second
And a second paint valve 114 are provided.

Accordingly, as shown in the time characteristic diagrams shown in FIGS. 11 and 12, the first intermediate pump unit 89, the first paint hose 95, the first paint valve 96 and the like are used to apply the A-color paint. In this case, the first high voltage cut-off portion E7 is formed by filling the first reservoir pump 92A with paint, discharging the paint A in the first paint hose 95A, and washing the paint. I do.

Further, the fourth high-voltage cutoff section E11 is formed by cleaning the second branch hose section 81C. Thus, when the paint discharged from the first storage pump 92A is being coated by the electrostatic coating machine 1, the second
Since the intermediate pump unit 107, the second paint valve 114, and the like are in the ground area E4, the second color paint can be filled into the second storage type pump 110 in parallel with the painting of the A color paint.

On the other hand, the second intermediate pump unit 107,
When applying the A color paint using the second paint hose 113, the second paint valve 114, etc., the second paint hose 113 discharges the A color paint and cleans the second paint hose. Is formed. Further, the third high-voltage cut-off portion E8 is formed by cleaning the first branch hose portion 81B.

As a result, the second storage pump 110A
When the paint ejected from the paint is applied by the electrostatic coating machine 1, the first intermediate pump unit 89, the first paint valve 96 and the like are in the earth region E4, so that the painting operation of the A-color paint is performed in parallel. Then, the next color paint can be charged into the first storage type pump 92.

Thus, according to the present embodiment, when the paint discharged from the first storage pump 92 is being applied, a coating preparation operation for filling the second storage pump 110 with the paint is performed. Also, when the paint discharged from the second storage pump 110 is being applied, a coating preparation operation for filling the first storage pump 92 with the paint can be performed. As a result, even when paints of the same color are continuously applied, one paint work can be performed in parallel with the other paint preparation work, so that setup time at the time of painting can be reduced, and workability can be reduced. Can be improved.

Although the fourth embodiment has exemplified the case where the paint valves 96 and 114 are provided in the ground area E4 (the paint source side), the present invention is not limited to this. A paint supply storage pump is provided at E4 (paint supply side) as paint supply means, and the paint supply storage pump is connected to the storage pumps 9 provided in the switching areas E6 and E9.
It is good also as a structure which supplies a paint to 2,110.

Further, in each of the embodiments, the case where the rotary atomizing head type electrostatic coating machine 1 is used as a coating machine is exemplified. However, the present invention is not limited to this, and for example, a spray gun type electrostatic coating machine is used. Other electrostatic coating machines may be used.

[0148]

As described in detail above, according to the first aspect of the present invention, the paint discharged from the storage type pump is supplied to the coating machine by the positive displacement pump. Can be supplied to the coating machine at a constant flow rate according to the coating conditions. As a result, the paint can be stably sprayed from the coating machine, so that the coating can be uniform and the finish of the coating can be improved, and the reliability of the electrostatic coating device can be improved.

Further, since the storage type pump is constituted by a cylinder, a piston, an actuator and the like, by displacing the piston by the actuator,
The paint can be smoothly filled and discharged, and the paint can be supplied stably to improve the paint finish.

According to the second aspect of the present invention, since the discharge amount of the paint by the storage pump is set to be equal to or larger than the discharge amount of the paint by the positive displacement pump, the discharge is supplied from the storage pump to the positive displacement pump. Insufficient supply of paint can be resolved, and paint can be supplied stably to improve the paint finish.

According to the third aspect of the present invention, most of the paint in the paint chamber can be discharged by one coating.
It is possible to prevent the resin and pigment in the paint from precipitating in the paint chamber, thereby preventing paint defects and improving the paint finish. Further, since the external dimensions of the storage pump can be reduced, the electrostatic coating apparatus can be reduced in size.

According to the fourth aspect of the present invention, since the positive displacement pump is constituted by a flushable gear pump,
When the color of the paint is changed, the paint of the previous color adhering to the shaft or the like supporting the gears can be washed, and coating failure due to color mixing can be prevented.

According to the fifth aspect of the present invention, at the time of color change of the paint, the pre-color paint adhered to the tip side of the coating machine can be washed by the washing fluid discharged from the tip washing passage,
Coating defects due to color mixing can be prevented. Moreover,
After this cleaning, the cleaning fluid in the tip cleaning passage is discharged by the cleaning fluid discharge means, and high-voltage leakage can be prevented by using the tip cleaning passage as an insulator. it can.

According to the sixth aspect of the present invention, the color changing valve device serving as the paint supply means and the storage type pump can be connected by one insulating paint flow path. The arrangement of the insulating paint flow path between the mold pump and the mold pump can be facilitated, and the workability of assembly can be improved.

According to the seventh aspect of the present invention, by providing a dedicated paint valve and an insulating paint flow path for each color, even if paint remains after washing, it is possible to eliminate color mixing with other color paints. As a result, the cleaning time can be shortened, and coating defects due to color mixing can be prevented.

According to the invention of claim 8, the paint supplied from the paint source side is filled in the paint supply storage type pump and temporarily stored therein, and the paint supply storage type pump is insulated from the insulating paint flow path. When the paint is discharged to the coating material, the paint is supplied at a high supply pressure, so that the paint can be supplied in a short time to the storage type pump on the coating machine side through the insulating paint flow path. Can be reduced in diameter. As a result, the amount of paint remaining in the insulating paint flow path, the amount of thinner required for cleaning, and the cleaning time can be reduced, so that productivity can be improved and running costs can be reduced.

According to the ninth aspect of the present invention, even when one paint supplied from the first paint supply means to the first storage type pump is applied by the coating machine, the second paint supply means can be used. The paint to be used for the next coating can be supplied to the second storage pump. In particular, when the same color paint is applied continuously, the preparation work can be performed in parallel with one of the paint work, so that the setup time at the time of paint can be reduced, and workability can be reduced. Can be improved.

[Brief description of the drawings]

FIG. 1 is a system diagram showing an overall configuration of an electrostatic coating apparatus according to a first embodiment of the present invention.

FIG. 2 is an enlarged longitudinal sectional view of the storage pump in FIG.

FIG. 3 is a characteristic diagram showing an operation state of each valve.

FIG. 4 is a system diagram showing an overall configuration of an electrostatic coating apparatus according to a second embodiment of the present invention.

FIG. 5 is a characteristic diagram showing an operation state of each valve.

FIG. 6 is a system diagram showing an overall configuration of an electrostatic coating device according to a third embodiment of the present invention.

FIG. 7 is a characteristic diagram showing an operation state of each valve.

FIG. 8 is a characteristic diagram showing the operating state of each valve, following FIG. 7;

FIG. 9 is a system diagram showing an overall configuration of an electrostatic coating device according to a fourth embodiment of the present invention.

FIG. 10 is a system diagram showing the entire configuration of the electrostatic coating device, following FIG. 9;

FIG. 11 is a characteristic diagram showing an operation state of each valve.

FIG. 12 is a characteristic diagram showing the operating state of each valve, following FIG. 11;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 rotary atomizing head electrostatic coating machine 4 thinner tube (tip washing passage) 7 high voltage generator 8,81 paint outflow hose (paint outflow passage) 9 gear pump 9A washing passage 19 storage pump 22 cylinder 24 piston 25 air cylinder (Actuator) 33, 61, 71 Paint hose (insulating paint flow path) 34 Color change valve device (paint supply means) 41 Thinner hose (tip washing passage) 44 Air valve (wash fluid discharge means) 62 Paint valve (paint supply means) 72 paint supply storage pump (paint supply means) 81B first branch hose part (first paint outflow passage) 81C second branch hose part (second paint outflow passage) 92 first storage pump 95 First paint hose (first insulating paint flow path) 96 First paint valve (First paint supply means) 110 Second storage pump 113 Second Paint hose (second insulating paint flow path) 114 Second paint valve (second paint supply means) E3, E7, E8, E10, E11 High voltage cutoff section Q1 Discharge amount of storage pump Q2 Discharge of gear pump Amount

Claims (9)

[Claims] 1. A paint supply means for supplying one or more colors of paint, an insulating paint flow path formed of an insulating material and having an upstream side connected to the paint supply means, and a downstream side of the insulation paint flow path. A storage pump for temporarily storing the paint supplied from the paint supply means and discharging the paint, a paint outflow passage provided on the discharge side of the storage pump, and a paint outflow passage. A coating machine that is provided on the tip side of the coating machine and atomizes while applying a high voltage to the coating material supplied from the storage type pump, and sprays the charged coating material charged at a high voltage toward the object to be coated; Before spraying the paint stored in the storage type pump, the paint of the paint color remaining in the insulating paint flow path is discharged by a cleaning fluid, and a flow path cleaning unit for cleaning, the electrostatic coating apparatus, The storage pump is And a piston slidably disposed in the cylinder to define a paint chamber in the cylinder. A paint is stored in the paint chamber or discharged from the paint chamber by displacing the piston. An electrostatic coating apparatus, comprising: a displacement pump that supplies a constant amount of paint discharged from the storage pump to the coating machine in the paint outlet passage. 2. The electrostatic coating apparatus according to claim 1, wherein the storage type pump sets a discharge amount of the paint to be equal to or more than a discharge amount of the paint by the positive displacement pump. 3. The electrostatic coating apparatus according to claim 1, wherein the storage type pump is configured to store an amount of paint required for painting one object to be coated in the paint chamber. 4. The electrostatic coating apparatus according to claim 1, wherein the positive displacement pump is configured as a flashable gear pump provided with a washing flow path for washing a shaft supporting a gear. 5. A tip washing passage made of an insulating material which discharges a cleaning fluid toward the tip in order to wash paint adhered to the tip of the coating machine, wherein the tip washing passage is provided. 2. The electrostatic coating apparatus according to claim 1, wherein a cleaning fluid discharging means for discharging the cleaning fluid in the front end cleaning passage is connected to the cleaning device. 6. The paint supply means is constituted by a color change valve device which selects and supplies one paint from a plurality of paints supplied from a paint source, wherein the color change valve device and the storage type pump are provided. 2. The electrostatic coating apparatus according to claim 1, wherein the connection is made by one insulating paint flow path. 7. The paint supply means is constituted by paint valves for each color, and between each paint valve and the storage type pump,
2. The electrostatic coating device according to claim 1, wherein the electrostatic coating device is connected by an insulating paint channel for each color. 8. The paint supply means is constituted by a paint supply storage pump separate from the storage pump, and an insulating paint flow path is provided between the paint supply storage pump and the storage pump. The electrostatic coating device according to claim 1, wherein the electrostatic coating device is connected. 9. The paint supply means comprises a first paint supply means and a second paint supply means for supplying paints of a plurality of colors, and the storage type pump supplies the first paint supply means with a first paint supply means. A first storage pump connected by a first insulating paint flow path and a second storage pump connected to a second paint supply means by a second insulating paint flow path; The passage connects a first paint outflow passage made of an insulating material that connects between the first storage pump and the positive displacement pump, and connects between the second storage pump and the positive displacement pump. A second paint outflow passage made of an insulating material, and the flow passage cleaning means is provided with a first insulating paint flow passage and a second paint outflow passage.
2. The structure according to claim 1, wherein the discharge and the cleaning of the paint are performed by combining with the paint outflow passage of the present invention, and the discharge and the wash of the paint are performed by combining the second insulating paint flow passage and the first paint outflow passage. The electrostatic coating apparatus according to the above.