JP2865251B1 - Powder coating booth for automotive body coating plant - Google Patents

Abstract

A coating plant in which a large object to be coated, such as an automobile body, is conveyed on a floor surface to perform powder coating, a structure in a booth is simplified to prevent stagnation of the coating and facilitate cleaning. In addition, the present invention provides a powder coating booth in which the volume of the bottom of the booth and the pit portion below the floor for accommodating the collection trough is reduced and the equipment is compact. An inner wall is made of a smooth insulating plastic material, and a bottom portion is divided into a vehicle body transport path portion and both side portions thereof, each having a Y-shaped cross section and a discharge port at a lower end of the bottom portion having a downward slope. A booth section to be formed, a cylindrical collecting trough having a receptacle airtightly coupled to the discharge port, partitioned at the center and connected at both ends to a suction duct leading to a separate cyclone or bag filter, A cyclone capable of detachably separating the paint depositing section; and providing a plurality of the paint depositing sections for each color.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a powder coating booth for a coating plant that handles multicolor powder coatings and powder-coats the outer surface of a large object to be conveyed on the floor.

[0002]

2. Description of the Related Art Solvent-type baking coating has been the mainstream in the exterior coating of the body of an automobile, since it requires a strong aesthetic appearance as well as corrosion protection. However, since the solvent-based paint has a thin one-coat film thickness, it must be applied at least four times, including an anti-corrosion electrodeposition primer, and the paint loss due to overspray is large. In view of the danger of powder coating, there is growing interest in powder coatings, and in some cases it has been adopted up to the middle coating repainting, but it has not yet been used for top coating repainting, which emphasizes appearance. It is.

[0003]

The powder coating can be coated one time thicker than the solvent-based coating, so that the number of coatings can be reduced and the oversprayed coating can be collected and reused. The yield is extremely high and the risk of environmental problems and fire is low. On the other hand, in order to reuse the recovered paint, it is not allowed to mix paint particles of a different color into the recovered paint. Therefore, it is necessary to carefully clean the inside of the paint booth and the paint circulation system when changing the paint color. For this reason, the line must be stopped for a few hours, so that if the color change is frequent, there is a drawback that the line operating rate sharply decreases.

The inventor of the present invention disclosed in Japanese Patent No. 2588687, "a coating booth having an inner wall made of a smooth insulating plastic material and having a Y-shaped cross section and a discharge port formed at a lower end of a downward slope. A cylindrical collecting trough detachably connected to a suction duct, one end of which is closed and the other end of which is detachably connected to a cyclone, having a receiving port which is airtightly connected to the discharge port, and a lower paint depositing section can be detachably separated. An electrostatic powder coating apparatus comprising a cyclone and a plurality of the collecting troughs and the paint depositing section for each color. " This makes it possible to easily replace parts that require a long time for cleaning, and only requires a short cleaning of the booth in the color change work, greatly shortening the line stop time for color change. became.

However, when an object to be coated is conveyed by an overhead conveyor, a hanger or a conveyor rail is used as an earth. However, the charged powder coating easily adheres to these members and accumulates during the coating operation. If the paint falls on the vehicle body due to vibration during transportation, etc., paint failure occurs. Therefore, it is preferable to use a cart that travels on the floor surface for transporting the vehicle body. However, in the case of a large object to be coated such as an automobile body, for example, the width of the painting booth 101 as shown in FIG. In a Y-shaped booth having a required slope, the depth of the pit 102 below the floor is about 4 m, and the entire construction is large.

Further, as shown in FIG. 9, a bogie rail 104 for a transport bogie 103 and a bogie driving chain 10 are provided in a booth.
5 and a chain rail (not shown) and a stand 106 for supporting them must be installed, so that the inside of the booth becomes complicated and paint tends to stay in places where the wind speed is low. . In addition, the length of the body painting booth is usually about 10 m, depending on the painting speed,
Accordingly, the outlet 107 and the collecting trough 108 become longer, making it difficult to exhaust the gas at a uniform wind speed in the longitudinal direction of the coating booth 101, and increasing the capacity of a cyclone (not shown) to make the device tall. As a result, the cleaning work at the time of color change takes time.

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 provide a coating plant in which a large object to be coated, such as an automobile body, is conveyed on the floor to perform powder coating. A powder coating booth with a simplified structure to prevent paint stagnation and easy cleaning, as well as reducing the volume of the bottom of the booth and the pit below the floor to accommodate the collection trough, and making the equipment compact. Is to provide.

[0008]

SUMMARY OF THE INVENTION The present invention relates to a powder coating booth for an automobile body coating plant which can handle multicolor paints and can change colors in a short time.
The inner wall is made of smooth insulating plastic material,
A bottom portion is divided into a vehicle body conveyance path portion and both side portions thereof, each having a booth portion forming a discharge port at a lower end of the bottom portion having a Y-shaped cross section and forming a downward slope, and a receiving port connected to the discharge port in an airtight manner. A cylindrical collecting trough connected to a suction duct leading to a separate cyclone or a bag filter having a partition at the center and both ends leading to a separate cyclone or a bag filter; and a cyclone capable of detachably separating a lower paint depositing portion. This is achieved by providing a plurality of parts for each color.

[0009] Further, by providing an adjusting duct for supplying a uniform airflow which is supplied from an air supply duct to the ceiling of the booth section and flows downward through a filter, and a floor is provided in the booth section at the time of painting. By raising the panel, the transportation of the vehicle body is not hindered, and at the time of cleaning, the floor panel is lowered to form a gondola, and a gondola for cleaning work that can travel in the booth is additionally provided. In addition, by arranging a compressed air pipe or a shower pipe in which air nozzles or hot water shower nozzles are arranged in a row, it is more effectively achieved.

[0010]

FIG. 8 shows the shape of the bottom of a painting booth 101 according to the present invention. As shown in FIG. 8, the booth bottom is divided into a space C between the bogie rails 104 and spray portions A and B on both sides, each of which has a Y-shaped downward slope. As is apparent from this figure, the depth Hl of the divided bottom is 1 / fraction of the bottom depth H2 when not divided, and the depth of the pit 102 can be reduced. In this case, a bogie rail 104, a bogie driving chain 105, a chain rail, and their supporting bases 10 are provided on the bottom portion C.
6 and the like, the shape becomes complicated and cleaning in a short time becomes insufficient. Therefore, the paint in the exhaust gas discharged from the discharge port 107 of the bottom C is not collected. The collection of the overspray paint is performed on the exhaust from the bottoms A and B.

[0011] Further, the center of the collection trough 108 is partitioned,
By suctioning from both ends by the suction duct 109, the difference in the exhaust speed in the longitudinal direction of the discharge port 107 of the long coating booth 101 becomes small, and the collection trough 108
It is possible to eliminate the stagnation of paint in the back. Therefore, in order to collect the staying paint, it is not necessary to replace the collection trough 108 for each color at the time of color change. If a drain is provided at the lower part of the trough, only warm water cleaning is required. This means that the color change work time can be saved and the pit space for trough replacement can be reduced.

By dividing the booth bottom as described above and further dividing the collecting trough attached to each into two parts at the center, the number of cyclones and suction fans increases, but
Since the capacity per unit is small and a small cyclone can be used, the equipment is compact, the color changing operation is easy, and the color changing time is shortened.

An embodiment of a powder coating booth according to the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a view for explaining the structure of a powder coating booth according to the present invention.
Is a booth inner wall 2 having a discharge port 107 at the lower end of each of bottoms A, B, and C having a plurality of Y-shaped cross sections, the work being provided on both sides thereof. No. 1 is supplied with air from the utility deck 3 and the air supply duct 5 and generates a downward airflow through the filter 4 provided on the booth ceiling. 1 and N
o. 2 Adjustment duct 6 and outlet 1 at the lower end of the booth bottom
07 and the collecting troughs 7, 8, 9 which are respectively connected to the discharge ports of the bottoms E, D of the work saw deck 3 to receive the exhaust air discharged from above and to be sucked from both ends by the suction ducts.
And a recovery system containing

The vehicle body 10 is mounted on a carrier 11 and is supported by a gantry 12 and is supported by a trolley rail 13 laid at a floor level.
It runs on the chain drive. 2 and 3 are diagrams for explaining the operation mechanism. Drive chain 1
4 is driven by a motor (not shown) along a chain rail 16 provided inside a discharge duct 15 surrounding it. A slit 17 is formed in the upper surface of the discharge duct 15, a cylindrical pin receiver 18 is disposed at a predetermined interval of the chain link, and a pin receiver 19 is protrudingly provided at the front of the carrier 11. The pin 1 is inserted into the pin receivers 18 and 19, and the two are engaged with each other.
1 is running.

FIG. 4 is a plan view showing a planar arrangement of the powder coating booth l. When the vehicle body 10 is conveyed into the booth inner wall 2 from the entrance at the bottom of the figure, the vehicle body 10 is first painted from above by a plurality of electrostatic spray guns 21 arranged side by side at the top of the booth. At this time, the spray gun 21 reciprocates right and left by the reciprocator 22 in order to equalize the spray density in the horizontal direction. Next, the body 10 is painted from both sides by spray guns 23 and 24 arranged in a plurality of rows. The guns arranged in each row reciprocate up and down by reciprocators 25 and 26, respectively. The interval between the spray guns 23 and 24 is
The positions of the reciprocators 25 and 26 are moved back and forth according to the width of 0, and set to appropriate positions. In FIG. 4, the spray gun 24 is moved from the booth inner wall 2 to the work saw deck 3.
It shows the state moved inside.

In the electrostatic powder coating, a predetermined amount of powder is discharged from a nozzle at the tip of a spray gun by compressed air, and is charged by passing between high-voltage electrodes facing the vicinity of the nozzle. When the charged particles coming out of the nozzle approach the vehicle body by the compressed air carrying force in the electric field created by the gun tip electrode and the grounded vehicle body, the charged particles generate an attractive force between the charged particles and the image charge generated on the vehicle body. Paint adheres to the car body. In addition, the charged particles passing through a place away from the vehicle body are discharged from the bottom outlet or stay in the booth by the action of the airflow and gravity in the booth inner wall 2 without being sucked into the vehicle body. Become.

In the embodiment shown in FIG. It is created by the air supply blown down from the regulating duct 6 through the filter 4 and the exhaust air from the collecting troughs 7 and 8 respectively connected to the bottoms A, B, C. As described above, the recovered paint is reused only for the exhaust from the collection trough 8, and the recovered paint is not reused for the exhaust from the collection trough 7. Therefore, if the exhaust from the inside of the booth inner wall 2 is mainly performed from the bottoms A and B, the paint recovery efficiency is increased. Therefore, the discharge duct 15 in FIG. 2 is supplied with air from a plurality of supply ducts 151 and is uniformly discharged from the slit 17.

FIG. 5 is a view showing the state of the airflow at the bottom C. The airflow discharged upward from the slit 17 prevents the airflow from the booth from entering the drive chain 14 in the discharge duct 15. ing. In addition, the transport trolley 1
If the air supply from the air supply duct 151 is adjusted in advance so that the air pressure inside the area surrounded by the bottom 1 and the bottom C becomes higher than the air pressure on the bottom A and the side B, the bottom C from the bottom A and the bottom C can be obtained. The airflow exits the collection trough 7 along the path indicated by the arrow without exhaust from the booth flowing into the inside.

As shown in FIG. 1, a work deck 3 is provided on both sides of the booth inner wall 2 so that a worker enters and exits for painting or cleaning. Is the No. of the ceiling. Since the air flows downward from the 2 adjusting duct 6 through the filter 4 and flows from the bottoms D and E to the collection trough 9 through the sawboard 301 laid on the floor, exhaust gas leaking from the inside of the booth inner wall 2 is discharged to the outside. Does not scatter.

FIG. 6 is a diagram showing an example of a recovery system from the bottoms AE to the exhaust to the outside. The collecting trough 8 connected to the outlets 107 of the bottoms A and B is closed at the center and connected at both ends to a suction duct 27, and is sucked by a suction fan 30 via a cyclone 28 and a bag filter 29. As disclosed in the above-mentioned patent, the cyclone 28 is configured to be able to separate a main body and a lower paint depositing portion, and the paint depositing portion constitutes a movable collection unit for each color together with a collection paint tank. . The air that has exited the cyclone 28 captures fine paint particles that have not been collected by the bag filter 29 and is exhausted from the outlet of the suction fan 30. On the other hand, bottom C, D
And the collection troughs 7 and 9 connected to the outlets of E and E are closed at the center and both ends are connected to suction ducts, respectively, and are sucked by the suction fan 32 through the bag filter 31,
It is being released into the atmosphere.

FIG. 7 is a sectional view of the same powder coating booth as FIG. 1, but shows a state at the time of cleaning. In this drawing, the spray guns 24 and 25 are retracted from the inside of the booth inner wall 2 into the work deck 3, and a gondola 33 for cleaning work is shown in the booth. The gondola 33 is a pair of rails 34 mounted on the booth ceiling in the longitudinal direction of the booth.
, And can run in the forward and reverse directions by the drive of the motor 35. The main body of the gondola 33 is composed of a beam 36 forming the upper surface, four corner pillars 37, and a floor panel 38 made of an expanded metal, a lattice or the like. By operating the wire winder, the floor panel 38 can be moved up and down by the guide pillars 39 fixed on both sides guided by the corner posts 37. In the figure, the floor panel 38 indicated by a broken line indicates the raised position, and at this time, the gondola 33 does not hinder the conveyance of the vehicle body 10.

In the powder coating booth for an automobile body coating plant as described above, the color changing operation is performed as follows. When the last painted body exits the painting booth 1, the supply of paint to the spray guns 21, 23, 24 is stopped, and paint hoses and paint in the gun are purged into the booth. To the outside of the inner wall 2. Next, while the suction fans 30 and 32 are in operation, the hoisting machine is operated to lower the floor panel 38 from the raised position to the lowered position, whereby a gondola 33 is formed, and the worker 40 moves from the working tape deck 3 to the gondola 33. You can transfer.

While the gondola 33 slowly reciprocates from the solid line position to the broken line position shown in FIG. 4, the worker 40 uses the air nozzle to remove the paint adhered to the inside of the boot inner wall 2.
Blow away with compressed air for cleaning. Alternatively, the compressed air pipe having the air nozzles arranged in a row is connected to the body frame of the gondola 33.
By arranging them in a system, the work can be automated. At the same time, the paint discharged from the bottoms A and B is collected by the cyclone 28. When the dry cleaning is completed, the suction fans 30 and 32 are stopped, and the collection unit for each color of the cyclone 28 is removed. Next, gondola 33
60 ° C from the shower nozzles arranged in the main body frame
The hot water at the highest possible temperature is blown out, and the inside of the booth is cleaned, and the inside of the cyclone is washed by flowing hot water at the above temperature from the connection part above the cyclone 28, and after these washing parts are dried, The color changing operation is completed by connecting the recovery unit for the next paint color to the cyclone 28.

[0025]

As described above, according to the powder coating booth for an automobile body coating plant of the present invention, in the large booth having a large bottom area, the bottom portion required for collecting the overspray paint without stagnation is required. The pit depth can be reduced while maintaining the slope. If the flow velocity of the air flow in the collection trough is 20 m / sec, the paint does not accumulate, but the flow velocity decreases as the air flow is farther from the suction port, so that the capacity of the suction fans 30 and 32 is increased to eliminate stagnation. I have to do it. According to the present invention, since the collection trough is divided into two parts at the center, the flow velocity is hardly reduced, so that the exhaust from the booth becomes uniform and the capacity of the suction fan does not need to be increased more than necessary.

Further, the booth bottom C has a complicated shape including the above-mentioned carriage transporting means and is difficult to clean. However, the paint trapped by the bag filter 31 from the exhaust passing through the bottom C is not collected (not reused). ), So there is no need to complete the cleaning. In this case, the exhaust air from the booth is mainly discharged through the bottoms A and B by the air flow discharged from the slit 17 on the upper surface of the discharge duct 15 in which the drive chain 14 is provided. Almost no effect. Further, the cleaning gondola 33 used in the present invention has a structure in which the floor panel 38 can move up and down with respect to the gondola main body, and does not hinder the transportation of the vehicle body when it is at the ascending position. Therefore, the gondola 33 does not have to be moved into and out of the painting booth 1 each time the work is switched, and only the raising and lowering of the floor panel 38 is sufficient, so that no time is required for preparation.

As a result, the large-sized powder coating booth for a body coating plant according to the present invention can suppress excessive capital investment, shorten the line stoppage time due to color change work, and improve the equipment operation rate. Was.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view for explaining a configuration of a powder coating booth according to the present description.

FIG. 2 is a cross-sectional view for explaining a vehicle body transfer mechanism according to the present invention.

FIG. 3 is a side view showing a relationship between a transport vehicle and a drive chain in FIG. 2;

FIG. 4 is a plan view showing an arrangement of a powder coating booth.

FIG. 5 is a cross-sectional view showing a state of airflow in a booth bottom C including a transport mechanism.

FIG. 6 is a diagram showing an example of a recovery system from the booth bottom section AE to exhaust to the outside.

FIG. 7 is a cross-sectional view showing the state of the powder coating booth of the present invention during cleaning.

FIG. 8 is a cross-sectional view showing the shape of the bottom of the powder coating booth according to the present invention.

FIG. 9 is a cross-sectional view showing one configuration example of a conventional large-sized powder coating booth.

[Explanation of symbols]

 1 powder coating booth 2 booth inner wall 3 work sink deck 4 filter 7, 8, 9 collection trough

Claims (4)

(57) [Claims] An inner wall surface is made of a smooth insulating plastic material, and a bottom portion is divided into a vehicle body transport path portion and both side portions thereof, each having a Y-shaped cross section and a discharge port at a lower end of the bottom portion having a downward slope. A booth section to be formed, a cylindrical collecting trough having a receptacle that is airtightly coupled to the discharge port, partitioned at the center, and both ends connected to a suction duct leading to a separate cyclone or bag filter, A powder coating booth for an automobile body coating plant, comprising: a cyclone capable of detachably separating the paint depositing section of the above. 2. The vehicle body painting plant according to claim 1, wherein an adjustment duct is provided at a ceiling portion of the booth section to supply a uniform airflow downward from the air supply duct through the filter and downward. For powder coating booth. 3. A cleaning operation in which a gondola is formed in the booth by forming a gondola by raising the floor panel at the time of painting so as not to hinder the conveyance of the vehicle body and lowering the floor panel at the time of cleaning. 2. The powder coating booth for an automobile body coating plant according to claim 1, further comprising a gondola. 4. A powder coating booth for an automobile body coating plant according to claim 3, wherein a compressed air pipe or a shower pipe in which an air nozzle or a hot water shower nozzle is arranged in line is arranged on the frame of the gondola.