JPS63185472A - Coating device - Google Patents

Abstract

PURPOSE:To apply a uniform coating as a whole by horizontally spreading a paint coated by an injection nozzle on an upstream side over the surface to be coated with an air blownozzle, and effectively coating the exposed tip edge of the surface to be coated with an injection nozzle on a downstream side. CONSTITUTION:The material 8 to be coated is hung and conveyed by a conveyor line 2 so that the most surface to be coated is almost horizontally placed in a main device body 1. The upstream injection nozzles 3 for almost horizontally injecting a water-soluble paint are respectively provided close to the line 2. The coated paint is spread over the surface to be coated on the downstream side of the nozzle 3 by the air almost horizontally blown from the air blownozzle 4. Scrapers 5 are brought into sliding contact with the inner wall surface of the main body 1 and vertically moved to scrape off the water-soluble paint on the inner wall surface, and the paint is recovered. A solvent-based paint is almost horizontally injected from the downstream injection nozzle 6 onto the metal to be coated on the downstream side of the nozzle 4, and electrostatic coating is carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an apparatus that can reliably coat a large number of metal plates, particularly those stacked together with extremely small gaps, over the entire area of the metal plates and even inside the metal plates.

[Traditional technique]

As an example, a heat exchanger such as a plate fin type heat exchanger in which a large number of plate fins are stacked with small gaps and a tube passes through each fin has conventionally been painted like a coat. First, a conveyance line is installed inside the coating equipment body,
The heat exchanger is suspended from the line and moved. At this time, the plate fins constituting the core of the heat exchanger are positioned approximately horizontally. Therefore, painting was done by spraying solvent-based paint horizontally.

[Problem to be solved]

However, such a coating method is difficult to apply, especially in a heat exchanger having a high density of fins, since the paint is applied only along the edges of the fins 9, as shown in FIG. QQ- It was not possible to paint all the way to the center of the fins 9. Therefore, the rust and corrosion prevention effects were lacking, especially for heat exchangers used under harsh conditions such as in construction machinery. was.

[Means for solving problems]

Therefore, the present invention takes the following configuration in order to eliminate the above problems and provide a highly economical coating apparatus.

That is, a conveyance line 2 is provided within the apparatus main body 1 for suspending and conveying objects to be coated so that most of the surfaces to be coated are positioned substantially horizontally. An upstream injection nozzle 3, an air blow nozzle 4, a scraper 5, and a downstream injection nozzle 6 are provided adjacent to the conveyance line 2, respectively. The upstream spray nozzle 3 sprays water-soluble paint in a substantially horizontal direction at an upstream position of the conveyance line 2. Further, the air blow nozzle 4 is used to spread the paint onto the surface to be coated by blowing air approximately horizontally at a downstream position of the upstream injection nozzle 3. Further, the scraper 5 moves from top to bottom in sliding contact with the inner wall surface of the apparatus main body 1 in order to scrape off and collect the water-soluble paint sprayed onto the inner wall surface of the apparatus main body 1. Further, the downstream injection nozzle 6 is provided downstream of the air blow nozzle 4, and is used to electrostatically spray the solvent-based paint onto the object to be coated in a substantially horizontal direction.

〔Example〕

Next, one embodiment of the present invention will be described based on the drawings. Fig. 1 is an explanatory schematic diagram of this device, cut horizontally, Fig. 2 is an explanatory longitudinal cross-sectional view of the same device, and Fig. 3 is a main part of a heat exchanger showing an example of the object 8 to be coated. The cross-sectional view and FIG. 4 are the same front views. FIG. 6 is a block diagram showing the coating process of this apparatus, and FIG. 7 is a longitudinal sectional explanatory view of the main part of the coating section corresponding to the block diagram. In this embodiment, as shown in FIGS. 2 and 4, the object 8 to be coated is a plate-fin type heat exchanger. That is, in the object to be coated 8, a heat exchanger core consisting of tubes 10 and fins 9 is placed between tanks 11 that are vertically spaced apart. In this heat exchanger, as shown in FIGS. 3 and 4, a large number of fins 9 are stacked with a small gap (for example, fin pinch 4 P -0°6m), and the tubes of the fins 9 A tube 10 is inserted and fixed into the insertion hole. For example, engine cooling water flows through the tube 10, and a cooling air flow flows outside the tube 10 and toward the outer surface of the fins 9. As shown in FIGS. 1 and 2, this coating apparatus is provided with a conveyance line 2 within the apparatus main body 1 for such an object to be coated 8. As shown in FIGS.

A plurality of upstream injection nozzles 3, one pair each, are provided at an upstream position of the apparatus main body 1. That is, a pair of nozzles 3a for painting the front side of the object 8 to be coated and a pair of nozzles 3b for painting the back side thereof are sequentially arranged. Next, a pair of air blow nozzles 4 are placed on the downstream side.
There are multiple locations. That is, first, a nozzle 4C for blowing air on the back side of the object table and a nozzle 4d for blowing air on the front side are sequentially arranged. Next, on the downstream side thereof, the inside of the device main body 1 is enlarged, and a plurality of downstream injection nozzles 6 are provided there. That is, a nozzle 6e for electrostatically coating the front side of the object 8 to be coated and a nozzle 6f for electrostatically coating the back side are provided. Note that the upstream injection nozzle 3. The axis of the air blow nozzle 4 is arranged parallel to the long axis of the cross section of the tube 10 with respect to the conveyance line 2. Further, the nozzles 3a, 3b to 4c, and 4d are provided so that their orientations can be changed within a horizontal plane. For example, when the tube 10 is installed obliquely with respect to the longitudinal direction of the fin 9 as shown in FIG. The nozzle 6e is arranged so as to be orthogonal to the conveying line 2, so that the spray angle of the nozzle can be changed in parallel to the tube installation angle. The respective nozzles 38 to 6f are provided so as to be movable in the vertical direction as shown in FIG. is provided with a scraper 5. This scraper 5 moves up and down from the position of the solid line to the position of the chain line as shown in FIG. 2 while in sliding contact with the inner wall surface of the main body 1 of the apparatus. A water stream 12 flows down from above to below in a film form at a position opposite to the nozzle 6.

Also, a drying oven 13° and a product unloading section 14 are installed at a position separate from the main body 1 of the apparatus. Product attachment portions 15 are provided respectively.

[For production]

Next, the operation of this coating device will be explained. First, the object to be coated 8 is suspended from the conveyance line 2 at the product attachment section 15 . At this time, the fins 9 of the object to be coated 8 are positioned horizontally. Then, the conveyance line 2 is moved to guide the object 8 to be coated into the apparatus main body 1. Therefore, a water-soluble paint is injected from a pair of nozzles 3a located on the most upstream side of the main body 1 of the apparatus. At this time, the viscosity of the paint should be relatively high. Then, as shown in FIG. 2, the object to be coated 8 is moved while moving the nozzle 3a up and down. Then, as shown in FIG. 7(a), a paint 16 is applied near one edge of the line 9 to form a pre-fuji between each fin 9. Then, the paint 16 is applied so that this bridge almost completely covers one entire surface of the object 8 to be painted.Next, while the object 8 to be painted is suspended from the line 2, it is turned upside down and A water-soluble paint is sprayed onto the back side of the object 8 using the nozzle 3b in the same manner as described above. Next, air is blown from the nozzle 4c to the back side of the object 8 to be coated, and the coating material 16 that has been bridged to one end edge of the fin 9 is spread inside the fin 9 as shown in FIG. 7(C). Then, the paint 16 reaches the center of the fin 9. However, due to the air blow, almost no paint is left on the tip edge of the fin 9, and that part is exposed.The object 8 to be painted is further inverted and air is blown by the nozzle 4d to remove the paint on the surface side of the object 8. Similarly, spread it out to the center. At the same time, the scraper 5 located on the opposite surface of the upstream injection nozzle 3 and the air blow nozzle 4 is moved from top to bottom to scrape off the paint adhering to the inner wall surface of the apparatus main body 1 downward. Then, the paint is supplied to a stirring device (not shown), its viscosity is adjusted, and it is again injected from the upstream injection nozzle 3.Next, the object to be coated 8 that has passed through the nozzle 4d is sent to the downstream injection nozzle 6. Move to the opposite position. Then, the solvent-based paint is sprayed from the nozzle 6e in a state in which the viscosity is reduced by the water-soluble paint and the paint is electrically charged. At this time, the object to be painted 8 is grounded. Then, the solvent-based paint is mainly adsorbed to the tip edges of the fins 9. Then, as shown in FIG. 7(e), the fin end face is electrostatically coated. Next, the object to be coated 8 is turned over and the back side is similarly electrostatically coated using the nozzle 6r. Then, the heat exchanger may be dried in the drying oven 13 and removed in the product unloading section 14.

It should be noted that the present invention is of course not limited to the above-mentioned embodiment, and can also be applied to a structure in which the tube 10 is disposed on the fin 9 as shown in FIG. 5, for example. In this case, the axis of each nozzle should be orthogonal to the conveyance line.
Also, in this example, an example in which the fin spacing is extremely small (for example, the fin pitch is 0.6 and the crane fin plate thickness is 0.3 m) has been described, but the same applies to cases where the fin pinch is larger than that. It can be carried out. Moreover, it can be applied not only to plate fins but also to corrugated fins.

It is also possible to provide a separate dryer between the area coated with the water-soluble paint and the area coated with the solvent-based paint.

〔Effect of the invention〕

This coating equipment has the above-mentioned configuration, and is a highly reliable coating equipment that can evenly coat heat exchangers that have fins that are stacked with high density and small gaps, and has a high rust and corrosion prevention effect. can be provided.

That is, first, the paint applied by the upstream injection nozzle 3 is horizontally spread on the surface to be painted by the air blow nozzle 4. Then, the leading edge of the surface to be painted exposed by the air blow from the air blow nozzle 4 can be effectively painted by the downstream injection nozzle 6. As a result, uniform coating can be applied as a whole.

Moreover, since the paint sprayed by the upstream spray nozzle 3 is water-soluble and is reused by the scraper 5, a highly economical coating apparatus can be provided. That is, this coating device has a transport line 2 that suspends and transports the object to be painted so that most of the surface to be painted is located approximately horizontally, and the water-soluble paint is sprayed approximately horizontally, and air blowing is also carried out. Since the nozzle 4 sprays horizontally, a lot of paint adheres to the inner wall surface of the apparatus main body l, but it can be scraped off by the scraper 5 and reused.

[Brief explanation of the drawing]

Fig. 1 is an explanatory schematic diagram of this device, cut horizontally, Fig. 2 is an explanatory longitudinal cross-sectional view of the same device, and Fig. 3 is a main part of a heat exchanger showing an example of the object 8 to be coated. The cross-sectional view and FIG. 4 are the same front views. FIG. 5 is a plan view of the fins 9 showing the painted state of a conventional heat exchanger, FIG. 6 is a block diagram showing the painting process of this device, and FIG. 7 is a diagram of the painted part corresponding to the same block diagram. FIG. l...Device main body 2...Transportation line 3...
Upstream injection nozzle 4...Air blow nozzle 5...Scraper 6...Downstream injection nozzle 7...Painting section 8...Object to be painted 9...Fin 10...Tube 11... ·tank
12...Water flow 13...Drying oven 1
4...Product unloading department 15...Product installation department Patent attorney Kubo 1) Takumi Figure 6 Figure 7 (d) (e)

Claims (1)

[Claims] The apparatus main body (1) has a conveyor line (2) for suspending and conveying the object to be coated so that most of the surface to be coated is positioned approximately horizontally, and The paint is applied to the surface to be painted by an upstream injection nozzle (3) which is provided and sprays the water-soluble paint in a substantially horizontal direction at an upstream position, and an air blow which sprays the water-soluble paint in a substantially horizontal direction at a downstream position thereof. Air blow nozzle to spread (4)
a scraper (5) that slides against the inner wall surface of the main body (1) and moves from top to bottom to scrape and collect the water-soluble paint sprayed onto the inner wall surface; and the air blow nozzle (4). a downstream injection nozzle (which sprays a solvent-based paint almost horizontally onto the object to be coated at a downstream position for electrostatic coating);
6) A coating device comprising: