JP2002248388A - Water curtain forming apparatus and coating booth having the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water curtain forming apparatus, in which the generation of splash is suppressed to be minimized even though a coating booth is made compact. SOLUTION: The water curtain forming apparatus (100) is for forming a water curtain (130) by making a water based fluid overflowed from an over flow tank (102) provided on the upper part to flow down on a curtain plate (106) and the curtain plate has a rugged surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water curtain forming apparatus for use in a coating booth for applying a water-based paint to an object to be coated, and a coating booth having such a water curtain forming apparatus.

[0002]

2. Description of the Related Art Generally, a water curtain forming apparatus is provided for applying a water-based paint to an object to be coated.
Use a painting booth with a booth tank below. In this case, the overspray paint that has not adhered to the object to be coated at the time of coating is supplied from the booth water tank to the overflow tank, overflows there, and flows down on the car template located in front of the object to be coated, by the booth water. Captured by the formed water curtain. The aqueous fluid forming the water curtain capturing the aqueous paint is collected in the booth tank, and then used again for the water curtain. Such a painting booth is called a water curtain type painting booth.

FIG. 3 shows an example of a water curtain type painting booth of such a water-based paint. In FIG. 3, an object 301 is coated with a water-based coating 306 sprayed from a coating gun 302 in a coating chamber 322 of a water curtain type coating booth 300. Overspray paint 304
Is captured by a water curtain 303 flowing down a car template 328 acting as a partition plate in front of the object 301 to be coated, collected in a booth water tank 320 provided at a lower portion of the coating booth 300, and in the collected booth water. Paint is dispersed.

[0004] The collected booth water is supplied by a pump P from a booth water tank 320 to an overflow tank 330 provided above the coating booth to form a water curtain, as shown by an arrow A. By overflowing from the tank 330 and flowing down, the water curtain 303 is formed and reused. In this way, the booth water is circulating in the painting booth 300.

[0005] Considering the incorporation of water-based paints, the fluid forming such a water curtain is preferably one containing water, in particular, one containing water as a main component. Fluids that form the curtain are collectively referred to as aqueous fluids (a fluid composed of only water is also included in the aqueous fluid). As is clear from the above description, the aqueous fluid may include an aqueous paint.

The car template 328 is placed in the coating chamber 300 in the vertical direction (ie, the vertical direction as shown) or obliquely close to the vertical (in the illustrated embodiment, obliquely) in front of the object 301 to be coated. Extending downward from the top of the coating chamber 300 along the lower right direction),
The booth water (aqueous fluid in the booth water tank 320) flows over it to form a liquid film as the water curtain 303. The booth water that has flowed down flows into the booth water tank 320 from the lower edge of the car template 328.

[0007]

As described above, when an object to be coated is coated while the water curtain is flowing down in the coating booth, fine droplets are generated from the flowing water curtain. Therefore, in the conventional water curtain type painting booth, no problem occurred because the distance between the object to be coated and the water curtain was sufficiently large.

In recent years, to meet the need for space saving,
The painting booth has been required to be more compact, and as a result, the distance between the object to be coated and the water curtain has been reduced. However, in this case, if the distance between the object to be coated and the water curtain is too short, there is a problem that the quality of the coating deteriorates if such droplets adhere to the object to be coated.

Specifically, in the case of the coating conditions generally employed in the above-described coating booth, if the distance between the object to be coated and the water curtain is set to about 100 cm or less, the quality of the coating will be reduced. This distance cannot be reduced further while ensuring the quality of the coating, because of the adverse effects of This is one of the obstacles to achieving a demand for a more compact paint booth and a smaller footprint for installing the paint booth.

[0010] Accordingly, an object of the present invention is to provide a water curtain forming apparatus which minimizes the generated splash while making the painting booth more compact. In other words, a water curtain forming apparatus capable of shortening the distance between the object to be coated and the water curtain, while ensuring the quality of the coating, as compared with the case of using the above-mentioned conventional painting booth is provided. It is to be.

[0011]

An object of the present invention is to provide a water curtain forming apparatus for forming a water curtain by causing an aqueous fluid to flow down on a car template by overflow from an overflow tank provided at an upper part thereof. It has been found that the problem is solved by a device characterized by having an uneven surface.

As described above, since the car template of the water curtain forming apparatus of the present invention has an uneven surface, it is possible to suppress the generation of droplets and / or to increase the flow rate when compared with a car template having a smooth surface. This allows the aqueous fluid to flow down as a water curtain. This is because when the aqueous fluid flows down on an uneven surface, the flowing resistance increases, and as a result, the flowing speed decreases, as compared with the case where the aqueous fluid flows down on a smooth surface. It is presumed that this is because

[0013] In the water curtain forming apparatus of the present invention, the uneven surface of the car template can reduce the speed of the water curtain flowing down as compared with the smooth surface. There is no particular limitation as long as the generation of the droplets can be relatively reduced, and the projections and depressions may have any form. However, if the degree of unevenness is too large, it may disturb the flow of the water curtain,
The turbulence may cause droplets. Therefore, in consideration of this, the form of the unevenness, the degree of the unevenness (the protruding distance or the depressed distance from the reference plane) and the like are considered in consideration of the allowable degree of the splash (the amount, size, the distance of the splash, etc.). Can be selected as appropriate.

The state of the unevenness on the uneven surface may be ordered or disordered. An ordered textured surface is one in which the surface on the car template through which the aqueous fluid flows has regular projections and / or depressions, ie, the dimensions (or dimensions) of the projections and / or depressions. ) And / or arrangement is regular. A disordered irregular surface is one in which such protrusions and / or depressions are irregular.

[0015] Specifically, the ordered uneven surface may be a perforated sheet provided with holes regularly, preferably a perforated sheet made of metal (for example, perforated metal), a mesh, preferably a metal mesh (for example, a thin metal mesh and three-dimensional It can be formed by an uneven surface providing element such as a metal mesh such as a wire mesh. The car template having such an uneven surface may be formed by providing, for example, laminating, an uneven surface providing element on a flat sheet, preferably a metal sheet.

In particular, it is particularly preferable to provide a plain-woven metal mesh on a flat metal sheet (for example, made of stainless steel). Instead of a plain-woven metal mesh, a mesh such as a plain tatami-woven wire mesh, a wire net, or a tie-lot woven wire mesh may be used.

The disordered uneven surface can be formed by roughening the sheet surface by adhering a granular material, for example, sand or metal powder, to a flat sheet, preferably a metal sheet. Preferably, it can be formed by shaving the surface of a metal sheet, for example, roughening the sheet surface by sandblasting. The sheet thus roughened is called a roughened sheet. In the case of a roughened sheet, since the sheet itself has an uneven surface, the roughened sheet itself can be used as a car template, and in combination with a flat sheet as in the case of the perforated sheet described above. It is not necessary to form a car template.

Further, the present invention provides a water curtain type coating booth for coating an object to be coated with a water-based paint, wherein the coating booth comprises the above-described water curtain forming apparatus of the present invention.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described in more detail with reference to the accompanying drawings. FIG. 1 schematically shows a perspective view of a specific example of the water curtain forming apparatus of the present invention.
In the water curtain forming apparatus 100 of the present invention, an overflow tank 102 is disposed at an upper portion thereof, and an aqueous fluid is supplied thereto.

In the illustrated embodiment, the aqueous fluid is supplied to the overflow tank 102 from the bottom thereof via a line 110, and the supplied aqueous fluid is supplied to the overflow wall 102 as a weir on the front wall surface 104 of the overflow tank 102 as indicated by an arrow B. (Functioning) Overflowing over the upper edge and flowing down on the substantially vertically arranged car template 106 as shown by arrow C to form a water curtain as a liquid film.

The upper portion of the car template 106 also serves as the front wall surface 104 of the overflow tank, and the substrate to be coated (not shown, oblique left front side in FIG. The arrangement location is indicated by a point 108.). still,
The water curtain forming apparatus 100 of the present invention has plates 120 at both ends 122 of the overflow tank 102 for attaching to an angle (not shown) mounted in the coating booth.

In this specification, the terms "before" and "after" are used to refer to the object (point 10)
8) is used to mean “forward” or “backward” with reference to the case where the user sees the image. When the target element is an object to be coated, the term “forward” or “rearward” is used with reference to the case where the water curtain forming apparatus 100 is viewed from there. Thus, the paint gun is located behind the workpiece (ie, point 108),
The water curtain forming device 100 is located in front of the object to be coated, the object to be coated is located in front of the coating gun, and the object to be coated is located in front of the water curtain forming device 100.

FIG. 2 is a schematic perspective view showing a part of the water curtain forming apparatus shown in FIG. The illustrated embodiment shows a state in which an aqueous fluid flows down on the car template 106 to form a water curtain 130.

FIG. 2 shows one specific embodiment of the car template 106 used in the water curtain forming apparatus 100 of the present invention. In this embodiment, the car template 106 is composed of a flat metal plate 132 and a wire mesh 134 laminated thereon, whereby the car template has an uneven surface, over which the aqueous fluid flows.

In the water curtain forming apparatus of the present invention, in a particularly preferred embodiment, a metal wire mesh, particularly a plain-woven metal wire mesh, is used to form the uneven surface of the car template. The mesh opening such as a wire mesh can be appropriately selected in consideration of the type of the aqueous fluid of the water curtain to be applied, the flow rate, the amount of generated droplets, and the like. About 20 mesh is preferable.

[0026]

EXAMPLE A 20-mesh plain woven wire mesh (stainless steel, SUS304) is laminated on a flat metal plate (stainless steel, SUS304) to form a car template having an uneven surface ("plain woven" in FIG. 4 described later). 1) having a car template formed of a flat metal plate having no wire mesh (referred to as a “flat plate” in FIG. 4 described later). An experiment was conducted under the following conditions, and the appearance of the droplets was visually observed.

Shape of car template: vertical length 3
000mm x width 300mm Supply aqueous fluid flow rate (1m / minute): 5L / min · m-6
5 L / min.m, Type of aqueous medium: Aude Recycle F-2000 diluted paint solution (solid content: 10%) The experimental results are shown in the graph of FIG.

However, in the graph of FIG. 4, the evaluation symbols mean the following states: Evaluation symbol Spread distance ◎ Within 200 mm ○ Within 500 mm △ Within 800 mm × longer than 800 mm

Note that the droplet reaching distance means a distance at which the droplet does not substantially reach a place beyond the distance and away from the car template. Also, in the graph, the plot located between the evaluation symbols means that the splash distance was between those symbols.

From these results, when the car template surface has irregularities, it is possible to reduce the splashing distance as compared with the conventional water curtain forming apparatus. The distance between the paint and the water curtain can be smaller, resulting in a more compact painting booth.
When the distances are made equal, the flow rate of the aqueous fluid can be increased, and as a result, the water curtain can be formed stably and uniformly.

[0031]

In the above-described water curtain forming apparatus, since the car template has the uneven surface, the generation of the splash caused by the water curtain can be suppressed. The distance between them can be reduced, so that the painting booth can be made more compact.

For example, when a conventional water curtain forming apparatus is used, it is substantially impossible to reduce the distance between the water curtain and the object to be coated to about 100 cm or less in consideration of the quality of coating. When the same conditions as those described above are applied, and when the water curtain forming apparatus of the present invention is used, the distance can be reduced to about 10 to 50 cm.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically showing a water curtain forming apparatus of the present invention.

FIG. 2 is a perspective view schematically showing a part of the water curtain forming apparatus of FIG.

FIG. 3 schematically shows a water curtain type painting booth of the prior art.

FIG. 4 is a graph showing the results of Examples.

[Explanation of symbols]

Reference Signs List 100: Water curtain forming device, 102: Overflow tank, 104: Front wall surface, 106: Car template, 108: Coating object, 120: Plate, 122: End of overflow tank, 130: Water curtain, 1
32: Flat plate, 134: Wire mesh, 301: Coating object,
302 ... paint gun, 303 ... water curtain, 30
4: overspray paint, 306: water-based paint, 320
... booth tank, 322 ... painting chamber, 328 ... car template, 330 ... overflow tank.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Noriyuki Sasaki 19-17 Ikedanakamachi, Neyagawa-shi, Osaka Nippon Paint Co., Ltd. (72) Inventor Tadayuki Sakai 1st Toyota Town, Toyota-shi, Aichi Prefecture Company F term (reference) 4D073 BB03 DC06 DC09 DC14 DC22 DC30 4D075 AA71 AA76 AA90 CA48 EA06

Claims (5)

[Claims] 1. A water curtain forming apparatus for forming a water curtain by causing an aqueous fluid to flow down on a car template by overflow from an overflow tank provided at an upper part, wherein the car template has an uneven surface. Equipment to do. 2. The apparatus according to claim 1, wherein the uneven surface is formed by a perforated sheet or a roughened sheet provided on a flat plate. 3. The apparatus according to claim 2, wherein the perforated sheet is selected from a punched metal and a mesh. 4. The apparatus according to claim 3, wherein the mesh is a plain woven wire mesh. 5. A water curtain type coating booth for coating an object to be coated with an aqueous paint, comprising a water curtain forming apparatus according to any one of claims 1 to 4. .