JPH11333342A - Powder coating booth - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently execute the suction of a coating material for an over- sprayed component by forming an air flow passage in which air flows from an aperture side to a recovering device side. SOLUTION: A special shaped pipe P is hung by a hook 15 and is carried in this state into a coating chamber 1a by a chain conveyor 10 when the coating of the special shaped pipe P is carried out in a coating booth 1. The door of a boot side wall is then closed and the spray coating by a coating gun 8 is executed in the state of operating the recovering device 35. The inside of the coating boot 1 is partitioned by a partition panel 20 to the coating chamber 1a and a recovering chamber 1b. This partition panel 20 is formed to a key shape in side view having a horizontal partition section 21 and a perpendicular partition section 22. The section between the horizontal partition section 21 and the ceiling 2 of the booth 1 is formed as the air flow passage 23. As a result, even if the powder coating material rises through a slit 24, the powder coating material is carried to the recovering chamber 1b and is recovered by the recovering device 35.

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 in which an object to be coated is hung inside to perform powder coating.

[0002]

2. Description of the Related Art A coating booth for performing powder coating on a deformed pipe such as a ductile cast iron pipe is basically in the form of a box having one open side, and the coating is performed from this open side. The dust collector is generally provided on the side opposite to the open surface for painting the object to be coated, that is, on the back side as viewed from the worker, and the air is provided from behind the worker to the back of the booth. It is flowing. Powder coating is characterized by higher coating efficiency than coating using solvent-based coatings. However, in order to further improve coating efficiency and reduce coating costs, extra paint (overspray) has been used.
Attempts have been made to collect and reuse the same.

[0003] Dust collection (collection) in this type of coating booth
There are three main methods. FIG. 4 is an explanatory view of a dust collecting method in the conventional booth B, in which an object to be coated in the booth is painted from an opening on the left side of the figure, and air is taken in an arrow direction from an intake port K provided at the right end of the figure. To collect dust. FIG.
(A) collects dust from the upper and lower central portions of the booth B, FIG. (B) collects dust from the bottom of the booth, and (c) shows a combination of these types. It collects dust from the center and bottom.

[0004] However, each of these conventional dust collection methods has the following problems. First, those that collect dust from the upper and lower central part of the booth shown in FIG.
Although a relatively uniform film thickness can be obtained, the flow of air in the lower part of the booth is poor, making it difficult to collect dust efficiently. Also, the one that collects dust from the bottom of the booth shown in FIG. 3B can collect dust relatively efficiently, but creates an airflow that promotes the powder that is heavier than air to fall down. Therefore, there is a problem that the thickness of the lower part is thicker than the upper part of the object to be coated. On the other hand, in the combination type shown in FIG.
It cannot be said that uniform coating can be performed sufficiently efficiently, and a fundamental solution has not been reached.

[0005] In a general coating line for performing coating while continuously transferring the object to be coated, the object to be coated P is usually hung by a hook of a chain conveyer passed through the top to perform the coating. In such a coating line, as shown in FIG. 3, a chain conveyor C is passed over a booth B, and a hook H is suspended in the booth through a slit provided on the ceiling of the booth.

[0006] In powder coating of a deformed tube, so-called hot coating is usually performed in which powder is coated on an object heated to about 200 ° C. Therefore, the air around the painted object is warmed, and an upward airflow from the painted object P to the ceiling of the booth B is generated. The flow velocity of the rising air current reaches 1.0 to 1.5 m / sec at a position 500 mm above the coated object, depending on the size of the coated object and the temperature of the coated object.

On the other hand, with the suction capacity of a normal dust collector or a collecting device used in a booth for powder coating, the flow velocity of the air flow around the coated object is only 0.1 to 0.5 m / sec. If powder coating is performed underneath, the paint is wound up by the rising airflow and passes through a slit on the ceiling of the booth to enter the chain conveyor. The paint that has entered the conveyor contaminates the conveyor and its surroundings, causing a problem that maintenance is troublesome.

In order to prevent the paint wound up by the rising airflow from entering the chain conveyor through the slit, it is conceivable to increase the flow velocity of the air flowing from the slit in the booth ceiling. Even if the suction capacity of the dust collector and recovery device of the booth is increased, the flow velocity of the air flowing through the slit on the ceiling does not become so high due to the structure, and only the flow velocity of the air flowing from the booth opening on the paint side is reduced. It becomes unnecessarily large, and the amount of powder paint adhering to the object to be coated is reduced. As a result, the coating efficiency is deteriorated, and the amount of the powder paint for the overspray increases. Conversely, if the suction capacity of the collection device is small, not only does the collection efficiency decrease, but also the problem that the sprayed powder paint returns to the hand and the workability deteriorates.

As a method of preventing the powder paint from entering the chain conveyor, a method of forcibly blowing air from a slit in the ceiling of the booth can be considered. However, according to this method, unless the distance from the painted object to the booth ceiling is equal to or greater than a certain value, the ascending airflow in the booth and the forcedly sent air interfere with each other to generate turbulence.
There is no problem when the ceiling of the booth can be relatively high, but when the ceiling of the booth cannot be made high due to restrictions such as the ceiling height of the installation location, turbulence tends to occur.
Since this turbulence causes a bad influence on the coating, the flow velocity of the air forcedly fed from the slit in the ceiling of the booth must be reduced, and as a result, the desired effect cannot be obtained in many cases.

[0010]

As described above, in the conventional coating booth, although the coating efficiency is reduced and the film thickness is reduced due to the improvement of the suction capacity of the recovery device, the powder coating is increased due to the increased film thickness. When the discharge amount is increased, the amount of the powder exceeds the suction capacity of the collection device, and the collection efficiency is reduced and the workability is deteriorated. On the other hand, when the suction capacity of the collection device is improved to improve the collection efficiency and workability, the coating efficiency has been reduced. For this reason, it has been difficult for the conventional painting booth structure to simultaneously improve the coating efficiency, the collection efficiency, the workability, and the like. Therefore, an object of the present invention is to solve the above-mentioned problems in the conventional coating booth by making the suction flow rate of the powder coating material recovery device in the coating booth adjustable.

[0011]

In order to solve the above problems, the present invention employs the following configuration. That is, the coating booth according to the present invention is open on the near side of the coating room,
In the powder coating booth where a paint collection device is provided on the back side and a conveyor that conveys the object is provided on the top, the opening is adjusted between the coating position of the object and the collection device. In addition to providing a partition panel having a possible ventilation hole, a partition is provided between the ceiling and the upper part of the coating chamber to form an air flow passage through which air flows from the opening side to the collection device side. .

It is preferable to provide an air flow passage at the bottom of the coating booth, through which air flows from the coating chamber where the objects to be coated are located to the collection device side. It is more effective if the opening amount of the air flow passage can be adjusted.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described more specifically based on embodiments of the present invention shown in the drawings.

As shown in FIGS. 1 and 2, the coating booth 1 is formed in a box shape by a ceiling 2, a bottom 3, a back panel 4, and left and right side walls 5, 6, and a front surface is formed with an opening 7.
The coating gun 8 is provided in this portion. Above the ceiling 5 of the booth 1, there is provided a chain conveyor 10 which is a device for transferring objects to be coated. The chain conveyor 10 is housed in a housing 11 having a groove shape in the left-right direction, and a slit 12 is formed at the bottom of the housing, that is, at the ceiling of the booth. The chain conveyor 10 is provided with a hook 15 that hangs down in the painting booth. A rod 16 connects the chain conveyor 10 and the hook 15. The housing 11 of the chain conveyor has a ventilation hole 1 communicating with the outside.
3,... Are provided.

The interior of the painting booth 1 includes a partition panel 20.
The chamber is partitioned into a coating room 1a and a collection room (chamber) 1b. The partition panel 20 includes a horizontal partition 21
And is formed in a key shape in a side view having a vertical partition portion 22,
The horizontal partition 21 is arranged below the ceiling 2 of the booth 1 with an interval therebetween, and an air flow passage 23 through which an air flow flows is formed between the two. The horizontal partition 21 is provided with a similar slit 24 immediately below the slit 12, and the hook 15 is connected to the slit 12, 24.
Through the coating room 1a.

At the center in the vertical direction of the vertical portion 22 of the partition panel 20, an elongated lateral slit-shaped ventilation hole 25,.
Is formed in a lattice-shaped ventilation window 26 in which is formed.
A sliding type panel 29 having a plurality of slit-shaped ventilation holes 27,... Formed at the same pitch as the ventilation holes 25,. It is attached so that it can be fixed at the position. The sliding panel 29 is a means for adjusting the opening of the ventilation window 26. When the slit-shaped ventilation holes 27,... Are completely overlapped with the slit-shaped ventilation holes 25,. A large amount of air in 1a flows into the collection chamber 1b through the ventilation window and the slit-shaped ventilation holes of the sliding panel. Also, the slit-shaped ventilation holes 25 of the ventilation window 26 and the slit-shaped ventilation holes 2 of the sliding panel are provided.
By adjusting the degree of overlap with 7, ..., the amount of airflow flowing through this portion can be adjusted, and when the sliding panel is fixed so that both slit-shaped ventilation holes are completely staggered, this portion There is almost no airflow from the coating room 1a passing through to the collection room 1b.

The bottom 3 of the coating booth 1 is formed in a trapezoidal shape slightly lifted from the floor surface, and between the bottom 3 and the lower end of the vertical portion 22 of the partition panel 20, a coating chamber 1 is provided.
An air flow passage 30 that communicates with the collection chamber 1b is formed. The opening degree of the air flow passage 30 depends on the partition panel 2.
The shutter can be adjusted by an up / down sliding shutter 32 attached to the shutter. A blower-type collecting device 35 for sucking and collecting the powder paint together with the air is installed inside the collecting chamber 1b. The paint sucked by the collecting device 35 is separated from the air by a separating device such as a filter, and the air is discharged outside the booth. Also,
The recovered powder coating is sent to the coating gun 8 via a reprocessing device (not shown) and reused.

On the left and right side walls 5, 6 of the coating booth 1, there are formed openings through which objects to be coated pass. The openings are opened and closed by sliding doors 40. The chain conveyor 10 carries an object to be painted into the painting chamber through an opening provided in one side wall 5 of the painting booth 1, and carries out the object to be painted through an opening in the other side wall 6. During the loading and unloading, the sliding door 40 on the side wall is opened and closed during the painting operation.

When an object to be coated (a deformed tube in the illustrated example) P is to be coated in the coating booth 1, the deformed tube P is heated to a predetermined coating temperature, and the chain conveyor 10 is hung by a hook 15. To carry it into the coating room 1a. In the example shown in the drawing, two deformed tubes can be simultaneously coated. When the object to be coated is carried in, the sliding door 40 on the side wall of the booth is closed, and spray coating is performed by the coating gun 8 with the collection device 35 operating.

In this coating booth 1, the ceiling has a double structure, and air is constantly flowing from the opening 7 to the collection chamber 1b. Even if it rises through 24, it is carried to the collection chamber by the airflow toward the collection chamber and collected by the collection device 35. Therefore, paint hardly enters the position of the chain conveyor 10. Also, from the coating room 1a to the collection room 1
(b) are provided at two places, that is, the upper and lower central part (ventilation window part 26) and the bottom part (flow passage 30), and the degree of opening thereof is adjustable. The condition of the airflow in the booth can be adjusted according to the length, shape, coating conditions, etc. of the booth. Therefore, a stable and uniform coating film can be obtained.

The shape and size of the ventilation hole of the ventilation window 26 and the means for adjusting the opening thereof are not limited to those shown in the drawings, but may be any suitable one according to the conditions of use.
For example, instead of using an elongated slit, a perforated plate having a large number of round or square holes may be used as a panel. Further, in the illustrated example, two objects are simultaneously coated, but only one object may be applied, or three or more objects may be applied simultaneously.

[0022]

As described above, in the coating booth according to the present invention, the suction speed of the entire booth can be efficiently suctioned while keeping the suction speed of the entire booth within a range that does not adversely affect the coating. It is no longer necessary to increase the capacity of the recovery device beyond necessity. In addition, it is possible to prevent the paint from entering the conveyor provided on the ceiling by generating an airflow flowing to the collection device side with the ceiling having a double structure.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a coating booth of the present invention.

FIG. 2 is a front view thereof.

FIG. 3 is a side sectional view of a conventional painting booth.

FIG. 4 is an explanatory diagram of a dust collection method in a conventional painting booth.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Painting booth 2 Ceiling part 3 Bottom part 4 Back panel 7 Opening 10 Chain conveyor 12 Slit 15 Hook 22 Partition panel 23 Air flow path 25 Slit 26 Vent window part 30 Air flow path 35 Recovery device P Modified pipe (object to be coated)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takaaki Exit 1-12-19 Kitahorie, Nishi-ku, Osaka-shi, Osaka Inside Kurimoto Ironworks Co., Ltd. No. 19 Inside Kurimoto Ironworks Co., Ltd. (72) Yoshisada Michiura 1-12-19 Kitahorie, Nishi-ku, Osaka City, Osaka Prefecture Inside Kurimoto Ironworks Co., Ltd. (72) Noriyuki Nakamura 19 Ikedanakacho, Neyagawa City, Osaka Prefecture No. 17 Nippon Paint Co., Ltd. (72) Inventor Yuji Hashimoto 3-4-2, Ishibashi, Ikeda-shi, Osaka Inside Cotem Co., Ltd. (72) Daisuke Shibata 3-4-27, Ishibashi, Ikeda-shi, Osaka In Cotem Co., Ltd.

Claims (2)

[Claims] 1. A powder coating booth having an opening on the near side of a coating room, a collecting device for paint on the back side, and a conveyor for conveying the object on the top is provided in a powder coating booth. A partition panel having a ventilation hole whose degree of opening can be adjusted is provided between the coating position and the collection device, and a partition is provided between the ceiling and the upper portion of the coating chamber, so that air flows from the opening side to the collection device side. A powder coating booth characterized by forming a circulating air flow passage. 2. The powder coating booth according to claim 1, wherein an air flow passage through which air flows from the coating chamber side to the collection device side is also provided at the bottom of the coating chamber.