JPH10165857A - Color change device for powder coater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sufficiently remove powder stuck on the inner peripheral surface of a paint hose by causing pressurized air to flow only. SOLUTION: In this device, plural paint tanks A, B, C from which plural kinds of powder paint a, b, c are sent by compressed air are separately connected to plural through holes formed on the same circumference of a fixed plate 71 of a paint change device 7, and on the circumference of the fixed plate 71, an elastic sphere forced feeding device 12 for pushing elastic spheres of a little larger diameter than the inner diameter of a hose 10 into a through hole other than the through holes by compressed air is provided. And in a rotary plate 72 rotated in slidable contact with the fixed plate 71, a connecting hole 11 communicating with one through hole selected from a group of the through holes of the fixed plate 71 is made, and also a switching device 8 is provided for doing the switching between a state in which the connecting hole 11 is connected to a spray gun 9 through the paint hose 10 and a state in which the connecting hole 11 is connected to an elastic sphere discharge hole 83 through the paint hose 10 and compressed air is fed to the spray gun 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color changing apparatus for a powder coating machine which uses a plurality of powder coatings having different colors by switching.

[0002]

2. Description of the Related Art Since a conventional powder coating machine has a single paint tank, when changing colors, first, an injector for sucking up powder paint by a flow of pressurized air and a powder paint tank are used. After closing the open / close valve and blowing out only air from the injector to blow off and clean the powder paint adhering in the paint hose and the internal path of the spray gun, the powder paint remaining in the paint tank The paint tank was taken out, and the inside and outside of the injector and the paint tank were washed by blowing compressed air, and then a new powder paint was put into the paint tank to resume painting.

[0003]

However, if air is simply blown out from the injector installed in the paint tank, the pressure drops due to the resistance when the paint passes through the paint hose and the nozzle of the spray gun. There was a drawback that a sufficient amount of air could not be obtained to blow off the powder paint adhered to the paint hose, and the powder paint remained in the hose.

Originally, in a paint hose, the wind speed at the center was high, and near the inner peripheral surface where the paint adhered, the wind speed was low, so it was difficult to remove the paint. In particular, when the paint hose was curved, The paint adhering to the inner peripheral surface on the inside was difficult to remove.

[0005] As described above, the paint adhered to the paint hose cannot be sufficiently removed only by blowing away by the air flow, and the paint remaining in the paint passage when replaced with another paint (color change). However, there has been a problem that a coating failure occurs when mixed with a new paint.

In addition, there is a problem that cleaning of the paint tank and the injector is required at the time of color change, and cleaning takes time and labor.

[0007]

As a means for solving the above-mentioned problems, the present invention relates to a method in which a plurality of paint tanks for feeding powder paint by means of an injector are arranged on the same circumference of a fixed plate of a paint switching device. It is separately connected to the plurality of through-holes formed above, and an elastic sphere having a diameter slightly larger than the inner diameter of the paint hose is pushed into the through-hole different from the through-hole with compressed air on the circumference of the fixing plate. An elastic sphere pumping device is provided, and a connecting hole for selecting and communicating with one of the through holes of the fixed plate is provided on a rotating plate which is slidably contacting the fixed plate and the connecting hole is connected to the spray gun via a paint hose. State to connect,
The connection hole is connected to the elastic sphere discharge hole via a paint hose, and a change device is provided for changing the state to a state in which pressurized air is supplied to the spray gun. One of the through holes of the fixing plate is connected to the connection hole by the rotation of the rotary plate to connect the paint hose to one of the paint tanks, and the changing device is set in a state where the connection hole is connected to the spray gun. By supplying pressurized air, the powder paint in the paint tank is ejected from the spray gun together with the pressurized air.

At the time of color change, first, the paint tank is shut off from the injector, and only the pressurized air flows into the paint path.
After the paint in the paint path is discharged from the spray gun and the paint path is prewashed, the rotating plate of the switching device is rotated to connect the connection hole to the through hole of the elastic sphere pumping device, and the change device is connected to the connection hole. When the elastic sphere is pushed into the paint hose through the connection hole by pressurized air in a state of being connected to the elastic sphere discharge hole and supplying compressed air to the spray gun, and discharged from the elastic sphere discharge hole of the changing device, Since the elastic sphere has a slightly larger diameter than the paint hose, the elastic sphere moves while elastically contacting the inner peripheral surface of the paint hose, scrapes the residual paint adhered to the inner peripheral surface, and wipes the inner peripheral surface of the paint hose clean.

The elastic sphere discharged from the elastic sphere discharge hole can be reused by washing.

[0010] The inside of the spray gun is washed with high pressure by compressed air.

In this way, when the cleaning of the paint path is completed, the rotating plate of the switching device is rotated to connect the connection hole to a desired through hole, and the changing device is moved to connect the connection hole to the spray gun. Then, pressurized air is supplied to the injector of the desired paint tank, and the powder paint in the paint tank is ejected from the spray gun together with the compressed air.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, reference numerals A, B, and C denote paint tanks, and pressurized powders a, b, and c placed on a fine wire mesh 1 are blown out from pipes 2a, 2b, and 2c, respectively. The air soars.

Numerals 3a, 3b and 3c denote injectors. Powder paints a, b and c are blown up by pressurized air supplied from pipes 5a, 5b and 5c, respectively. Open powder tanks a, b, and c from one of the paint tanks A, B, and C, and supply the powder paints to the paint hoses 6a, 6b, and 6c.

In FIG. 1, 7 is a switching device described in detail in FIGS. 2 to 5, 8 is a changing device described in FIGS. 6 to 9, 9 is a spray gun, and 10 is a switching device 7 and a changing device. 8 is a paint hose for connecting the paint hose.

The switching device 7 includes a fixed plate 71 and a rotating plate 72.
In the fixed plate 71, through-holes 71a, 71b, 71c, 71d and spare through-holes are formed at equal intervals on the same circumference, and the through-holes 71a, 71b, 71c have paint hoses 6a, 6b and 6c are connected, and
1d, a pipe 73 is connected to the back surface, and the pipe 73
A filling tube 74 is set up on the upper surface of
An elastic sphere x composed of a sponge or a cotton ball having a diameter slightly larger than the inner diameter of 0 is filled, and the elastic spheres x are passed one by one by pressurized air ejected from a nozzle 75 connected to the rear end of the pipe 7. The pipe 73, the filling cylinder 74, and the nozzle 75 constitute the elastic sphere pumping device 12 by pressure feeding into the hole 71d.

The rotating plate 72 is in close contact with the fixed plate 71, rotates on a concentric axis, and has a connection hole 11 extending from the center of the front end to near the outer periphery of the rear end. The holes 11 are through holes 71a, 71b,.
‥ and any one of ‥
The front end of 1 is connected to the paint hose 10 in an airtight manner and in a freely rotatable manner.

The changing device 8 comprises a fixed body 81 and a moving body 82. The fixed body 81 has a through hole 84 communicating with the spray gun 9 from the rear surface in the upper stage and an elasticity communicating obliquely downward from the rear surface to the front surface in the lower stage. A sphere discharge hole 83 is formed. The moving body 82 has a through hole 85 communicating with the pressurized air supply pipe 87 at the upper stage and the paint hose 1 at the lower stage.
The moving body 82 moves up and down in close contact with the rear surface of the fixed body 81 so that the through hole 86 is aligned with the through hole 84 at the upper position and the through hole 85 at the lower position. Are aligned with the through holes 84, and the through holes 86 are aligned with the elastic sphere discharge holes 83, respectively.

Hereinafter, the operation of the present embodiment will be described.

At the time of coating, as shown in FIGS. 2 and 3, one through-hole 71a, 71
b ‥‥‥ is set to 1 by the rotation of the rotary plate 72.
6 and 7, the changing device 8 is connected to the spray gun 9 in the state shown in FIGS. 6 and 7, and the injectors 3a, Compressed air is supplied to 3b and 3c to cause one of the powder paints a, b and c in the paint tanks A, B and C to be ejected from the spray gun 9 together with the compressed air.

At the time of color change, first, the opening / closing valves 4a, 4b, 4c of the paint tanks for the paints a, b, c which have been painted are closed, and the paint tanks A, B, C are connected to the injectors 3a, 3a.
b, 3c and only the pressurized air and paint hose 6a,
6b and 6c, and paints a, b and c in the paint hoses 6a, 6b and 6c and the paint hose 10 are spray gun 9
After the paint path has been preliminarily washed out by rotating the rotating plate 72 of the switching device 7 to the position shown in FIGS. 4 and 5, the connection hole 11 is connected to the through hole 71d of the fixed plate 71, and FIG. As shown in FIG. 9, the changing device 8 is connected to the elastic sphere discharge hole 83 by the hose 10 and pressurized air is supplied to the spray gun 9 to eject the elastic sphere x from the nozzle 75 of the elastic sphere pumping device 12. When the compressed air is pushed into the paint hose 10 through the connection hole 11 and discharged from the elastic sphere discharge hole 83 of the change device 8, the elastic sphere x has a slightly larger diameter than the paint hose 10. While moving while resiliently moving, the paint remaining on the inner peripheral surface is scraped off and the inner peripheral surface of the paint hose 10 is wiped clean.

The elastic sphere x discharged from the elastic sphere discharge hole 83 can be reused by washing.

The inside of the spray gun is washed with high pressure by pressurized air supplied from a pressurized air supply pipe 87.

When the cleaning of the paint path from the switching device 7 to the spray gun 9 is completed in this way, the rotating plate 72 of the switching device 7 is rotated to connect the connection hole 11 to the desired through hole 7.
1a, 71b,... And the moving body 82 of the change device 8 is moved upward so that the connection hole 11
0, return to the state connected to the spray gun 9 and open / close valves 4a, 4b, 4c of the desired paint tanks A, B, C, and open the paint tanks A, B, C by injectors 3a, 3b, 3c. Is sprayed from the spray gun 9 together with compressed air.

[Brief description of the drawings]

FIG. 1 is a route diagram according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of the switching device.

FIG. 3 is a sectional view of the same.

FIG. 4 is an exploded perspective view of the switching device.

FIG. 5 is a sectional view thereof.

FIG. 6 is an exploded perspective view of the changing device.

FIG. 7 is a sectional view of the same.

FIG. 8 is an exploded perspective view of the changing device.

FIG. 9 is a sectional view of the same.

[Explanation of symbols]

 A, B, C: paint tank a, b, c: paint x: elastic sphere 3a, 3b, 3c: injector 7: switching device 8: changing device 9: spray gun 10: paint hose 11: connection hole 12: elastic sphere Pumping device 71: fixed plate 71a, 71b, 71c, 71d: through hole 72: rotating plate 83: elastic sphere discharge hole

Claims (1)

[Claims] 1. A plurality of paint tanks for feeding powder paint by an injector are separately connected to a plurality of through holes formed on the same circumference of a fixed plate of a paint switching device, and said fixed plate is An elastic sphere pumping device for pushing an elastic sphere having a slightly larger diameter than the paint hose into the through-hole different from the through-hole with compressed air on the circumference is provided. A connection hole for selecting and communicating one of the through holes is provided, and the connection hole is connected to a spray gun via a paint hose, and the connection hole is connected to an elastic sphere discharge hole via a paint hose. And a color changing device for a powder coating machine provided with a changing device for changing a state in which pressurized air is supplied to the spray gun.