JP2588687B2 - Electrostatic powder coating equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic powder coating apparatus which handles multicolor paints and can easily change colors in a short time.

[0002]

2. Description of the Related Art Electrostatic powder coating does not discharge a solvent,
In recent years, it has gained an important position in the field of painting because of its environmental and economic advantages, such as the ability to recover and reuse paint that was not applied during spraying. FIG. 5 is a view for explaining the configuration of a general electrostatic painting line conventionally used. An object to be coated (hereinafter referred to as a work) is loaded on a hanger of the conveyor 1 at a point A on the circulation conveyor 1 and is carried into the coating booth 2. The coating booth 2 has two areas for spray-coating charged powder coating materials from both sides in the work transfer direction. In each area, a plurality of spray guns 3, 7 for spray-coating the powder paint under the control of coating machines 4, 8 are provided, and these spray guns 3, 7 are respectively reciprocator 5, 9, Reciprocate up and down, and successively conveyed workpieces are sequentially painted. The work then enters the baking furnace 19, where it is heated at a predetermined temperature and for a predetermined time to form a film by a melting or thermosetting reaction, then cooled on the conveyor 1 and unloaded at point B.

In addition, each spray gun 3 in the painting booth 2
On the opposite side of 7, there are provided suction ports 10, 10 ′ connected to exhaust fans 14, 18, respectively, for sucking oversprayed paint and sending it to cyclones 12, 16.
Paint which has passed through the cyclone 12, 16 are separated and recovered most part, it is further captured fine powder in bug Huy filter 13 and 17, is exhausted through the exhaust fan 14 and 18. The paint thus recovered is applied to coating machines 4, 8
It is added to the paint supply tank provided in the tank and reused.

[0004]

As described above, the powder paint can significantly increase the paint yield by recovering the overspray paint as compared with the solvent paint. In the case of alternately applying paint, it is necessary to carefully clean not only the paint system but also the paint booth and the collection system when changing colors. That is, coating of the particles have a substantially particle system close to the film thickness, since it does not disperse as high solvent paint also <br/> viscosity during heating and melting, produce spots as different color paint is mixed trace Defective products are generated, and the recovered paint cannot be reused. Performing the entire cleaning every time the color is changed in order to prevent such contamination of the recovered paint results in stopping the operation of the line for a long time, and the equipment operation rate is significantly reduced.

[0005] To eliminate the stoppage at the time of color change, it is sufficient to provide a coating line for each color, but the capital investment increases and the cost merit due to paint recovery is lost. For this reason, a method of exchanging only the collection system at the time of color change is performed. For example, there is a method in which the entire collection system using a cassette filter is unitized and prepared for each color, and the color change is performed by attaching a required collection unit to a painting booth. This method is suitable for small-capacity small-sized coating equipment because paint collection is performed only by a filter, but is not suitable for large-capacity coating lines.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to facilitate cleaning work in a paint booth and to reduce the number of replacement parts at the time of color change.
Another object of the present invention is to provide an electrostatic powder coating apparatus capable of changing colors in a short time by facilitating replacement.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a booth and a recovery system of an electrostatic powder coating apparatus which can handle multicolor paints and can change colors in a short time. wall is made smooth insulating plastic material, cross-section
A paint booth that forms a discharge port at the lower end of the bottom that forms a Y-shape and has a downward slope. a cylindrical collecting trough which is connected to, achieved by the lower portion of the coating deposition unit capable comprises a cyclone can separate detachable, electrostatic powder coating apparatus provided with a plurality for each color of the collection trough and the coating deposited section Is done.

[0008]

Since the inner wall of the coating booth is formed of an insulating material, no image charge is generated by the charged particles, and therefore, the charged paint particles do not generate an electrostatic attraction with the wall surface. Further, since the wall has a smooth shape, it can be easily cleaned by wiping with an air blow or a mop. Further, by running the gondola as a working scaffold, the cleaning operation is performed quickly and safely. In the recovery system, paint does not adhere to the suction duct or cyclone body with high flow velocity.
Further, since the bag filter is difficult to clean and has a small collection amount and does not greatly affect the collection efficiency, the bag filter is not collected.
Therefore, the change in color change is limited to the collection trough and the paint accumulation portion of the cyclone. All of these exchange parts are moved by a cart and can be exchanged in a short time if they can be set at the exchange position. Cleaning of the removed replacement part is performed off-line and does not affect the availability of the line. Since each replacement part is used for each color, it is not necessary to completely clean the parts, and it is not necessary to clean them every time.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the apparatus of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of an electrostatic powder coating apparatus according to the present invention. The workpiece 20 conveyed by the conveyor is spray-painted with the charged powder paint by the spray guns 22 and 22 'while passing through the painting booth 21. At this time, the overspray paint which is not applied to the work 20 is formed into a cylindrical collecting trough 24 which is exchangeably attached to a lower portion thereof through a discharge port 23 connected to a slope at the bottom of the booth having a Y-shaped cross section and forming a downward slope. Sucked into. One end of the cylinder of the collection trough 24 is closed, and the other end is detachably connected to a suction duct 26 that suctions by driving a suction fan 25, and the paint sucked into the collection trough 24 is sent to a cyclone 27 together with air. . The cyclone 27 is configured to be able to separate a main body and a lower paint depositing section 28, and the paint depositing section 28 constitutes a movable collection unit for each color together with a collected paint tank 29. The air that has exited the cyclone 27 captures the fine paint particles that have not been collected by the bag filter 30,
5 is exhausted.

FIG. 2 is a cross-sectional view showing the details of the painting booth, and shows a state when the electric gondola 31 for work is used. The inner wall 32 of the painting booth 21 is made of an insulative plastic material such as hard vinyl chloride or FRP, and is formed with a curved surface that does not cause powder accumulation. Opening and closing doors (not shown) are provided before and after the booth, and a cut portion 35 serving as a passage for the work hanger 33 and the gondola hanger 34 is provided on the ceiling. In addition, to the Y-shaped cross section
A discharge port 23 having a vertical side surface is formed in a central portion of the bottom which forms a downward slope . A flange 231 for connecting the collection trough 24 is provided outside the outlet 23.

The electric gondola 31 has two rails 341.
And run in forward and reverse directions by a drive motor (not shown). Also, a plurality of fans 36 are provided on the upper part,
The air flowing from the notch 35 flows from the overhead of the worker 37 toward the bottom. In this way, fresh air is always supplied to the worker 37, and the paint scattered from the wall surface due to cleaning is not sucked.

As shown in FIG. 1, a replacement collection trough 241 is mounted on a cart 242 and is placed at a fixed position on a table lifter 40 installed in a pit. Here, when the table lifter 40 is raised, the receiving trough 241 is closed.
The reference numeral 43 and the connection end are set at the connection positions with the discharge port 23 and the suction duct 26, respectively, and can be connected by a simple method using a one-touch fitting or the like. FIG. 3 shows a specific example of these connections, in which the collection trough 241 and the outlet 23
The flanges 244 and 231 respectively provided on the discharge ports 23 are brought into contact with the table lifter 40 with the packing material interposed therebetween.
The plurality of U-shaped brackets 232 pivotally attached to the flange 231 on the side are joined by rotating. Similarly, the flanges 245 and 261 provided on the end surface of the collection trough 241 and the end surface of the suction duct 26 respectively have a plurality of U-shaped metal fittings 26 which are axially mounted on the flange 261 on the suction duct 26 side.
Two rotations are combined.

FIG. 4 is a view showing an example of the structure of a recovery unit attached to the cyclone body. The collection unit 50
A frame 52 mounted on a cart 51, a paint depositing section 28 supported by a support member 521 provided on the upper portion of the frame 52 so as to be able to move up and down, and a collected paint that receives collected paint discharged from the paint depositing section 28. And a tank 29. The paint depositing section 28 includes a hopper 281 and a rotary valve 282, and can take out paint in the hopper 281 to the outside while maintaining a sealed state inside the cyclone 27. The hopper 281 has a flange 283 formed on the upper end surface thereof and connected to the cyclone body, and is supported by the support member 521 below the flange 283. The support member 521 slides along the column 523 by sleeves 522 fixed at four corners, and moves up and down by the operation of the cylinder 53. As shown in FIG. 1, the collection unit 50 is attached and detached by carrying the collection unit 50 below the cyclone main body, operating the cylinder 53 to bring the flange 283 into contact with the main body side flange 271, and connecting them using a fitting.

In the above electrostatic powder coating apparatus,
The color changing operation is performed in the following order. First, the supply of the paint to the spray guns 22 and 22 'is stopped, and the paint in the paint hose and the gun is purged into the painting booth 21 by compressed air. Next, when the operator 37 enters the booth while riding the gondola 31, the opening / closing door of the booth is closed, and the fan 36 above the gondola 31 is driven. While the gondola 31 is running slowly in this state, the worker 37 cleans the surrounding wall using an air nozzle or a mop, and the like.
The cleaning is completed when 1 reciprocates in the booth 21. At the same time, the door is opened and the gondola 31 is returned to the standby position outside the booth.

When cleaning of the booth 21 is completed, the fan 36
Is stopped, the empty truck on the table lifter 40 is raised to the receiving position of the collecting trough 24 to disengage the connection with the discharge port 23 and the suction duct 26, and the collecting trough 24 is lowered on the bogie, moved to the standby position and exchanged. Collection trough 2
41 is mounted as described above. At the same time, the recovery unit 50 is disengaged from the cyclone body,
The operation of the cylinder 53 lowers the surface of the flange 283 and exchanges it for a recovery unit for exchange. Note that the bag filter 30 is difficult to clean, the amount of the captured paint is small, and the bag filter 30 is fine and is not collected and used. Therefore, cleaning by color change is not required.

[0016]

As described above, according to the electrostatic powder coating apparatus of the present invention, a structure that requires cleaning when changing colors and that requires a long time for cleaning can be easily replaced. Only the inside of the booth needs to be cleaned, and the booth has a structure that makes it easy to clean, and provides the auxiliary means that allows the cleaning worker to work quickly and safely. It has become possible to remarkably reduce the line stop time due to the necessary color change.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of an electrostatic powder coating apparatus according to the present invention.

FIG. 2 is a diagram for explaining details of a coating booth according to the present invention.

FIG. 3 is a diagram showing an example of connection between a collection trough, a painting booth, and a suction duct.

FIG. 4 is a view for explaining the structure of a collection unit according to the present invention.

FIG. 5 is a view for explaining a configuration of a conventional electrostatic coating line.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 21 Painting booth 22, 22 'Spray gun 27 Cyclone 30 Bag filter 20 Work 23 Outlet 24, 241 Collection trough 25 Suction fan 26 Suction duct 28 Paint accumulation part 29 Collection paint tank 31 Electric gondola 40 Table lifter 50 Collection unit

Claims (6)

(57) [Claims] An inner wall surface is made of a smooth insulating plastic material, has a Y-shaped cross section, and has a downwardly sloped bottom, forming a discharge port at a lower end thereof , and a receiving port which is hermetically connected to the discharge port. the a, can detachably separating a cylindrical collecting trough which the other end one end is closed is detachably connected to a suction duct leading to the cyclone, the paint deposition portion of the lower
That includes a cyclone, electrostatic powder coating apparatus characterized by comprising a plurality for each color the collection trough and the coating deposited section. 2. The electrostatic powder coating apparatus according to claim 1, wherein the insulating plastic material is a hard vinyl chloride material or an FRP material. 3. An electric gondola suspended from the booth during operation of the coating apparatus and suspended in the booth during cleaning with a worker on the painting booth. The electrostatic powder coating device according to claim 1, which is additionally provided. 4. The electrostatic powder coating according to claim 1, wherein a table lifter is provided in the underfloor pit below the discharge port, for raising and lowering a bogie for placing and transferring a collection trough for replacement. apparatus. 5. The paint depositing section according to claim 1, wherein the paint depositing section includes a cover attached to a truck.
Les chromatography beam onto vertically movable engaged with the electrostatic powder coating apparatus according to claim 1, which is unitized with the recovery paint tank is housed in the frame. 6. An upper surface of the electric gondola, which takes in outside air from an opening of the ceiling of the painting booth, generates an air flow from above to below in the booth, and supplies fresh air to an operator. The electrostatic powder coating device according to claim 3, further comprising a fan.