JPS6279870A - Powder coating device for small articles - Google Patents

Abstract

PURPOSE:To surely obtain a coated film surface which is consistent and has a high grade by using a hollow belt-like conveyor belt having a u-shaped section as a powder tank and a frame body having fine pores 9 on the top surface as an air chamber and forming an air layer between the air chambers. CONSTITUTION:A circulation type powder transfer tank device 5 of a device for coating powder to mainly small particles over the entire part thereof without giving flaws thereto consists of the conveyor belt 6 formed to the hollow belt- like powder tank having the u-shaped section and is further formed with the air chamber 8 toward the lower side thereof by a frame body 7 which is provided with a fan 10 on the outside and is provided with fine holes 9 for ventilation on the top surface. The air film layer (b) is formed between the conveyor belt 6 and the air chamber 8. Then, the articles to be worked are adsorbed by the ejected powder at the falling point where the articles are discharged after heating. The powder is thermally melted to then tacky state. The articles are carried to the powder transfer tank having the air film layer and are embedded into the powder, by which the second coating is executed. The painted surface which is consistant and has the high grade is thus surely obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention mainly relates to a powder coating apparatus for small articles that can uniformly and accurately coat the entire small article without wasting time.

In recent years, the development of industrial products has been rapidly progressing, and there has been a tendency for them to become more and more sophisticated, and more sophisticated products are becoming more compact.The various parts used in these products are changing from main parts to terminal parts. Improving precision has now become an essential element, and there is also a demand for surface strength and abrasion resistance.
There is a strong demand for high precision as well as fineness in the appearance of objects.

Conventionally, the methods for painting small objects include immersing them in a suspended state in a flowing powder, and placing a large number of workpieces in a net-like case and immersing them in a flowing powder. A method is adopted in which the coating is applied by shaking the surface. However, the previous method has problems such as leaving scratches on the hanging part, and the welding method leaves many workpieces on top of each other, so it is extremely difficult to improve accuracy. It is not desirable to improve the accuracy of both methods jointly.

In addition, the method disclosed in Japanese Patent Publication No. 52-22649 requires a cooling water device, and vibrates the heated article and the powder at the same time. The method is structured such that the article is applied while being moved toward the outlet located at the article, and the article and the powder are distributed. Furthermore, the method disclosed in Japanese Patent Application Laid-Open No. 57-110370 is such that the supplied powder is buried below the interface height inside the powder flow chamber installed in the vibration generator, and the bottom part of the powder is buried below the interface height. A sieve screen is built in which has a sieve screen and is inclined toward the center, and the article is dropped onto the center bottom of this sieve screen. The method is such that the powder is vibrated together with the sieve screen, gradually raised toward the outlet along the slanted surface of the sieve screen, and coated, and the article and the powder are simultaneously sieved.

However, although all of the above methods share the method of gradually raising the material toward the exit using vibration, in both of these methods, the heated article is coated by applying vibration. Therefore, there is a drawback that the coated surface inevitably ends up being thin. Further, in order to completely avoid dust pollution caused by the flying up of microscopic powder paint generated by vibration, a large-scale protective case is required.

Furthermore, during the research using the prototype machine related to the present application, it was found that fine powder coating of less than 100μ was applied to the drive unit and each gear, which had a slight heat temperature, especially in the article transfer device (belt conveyor). It adhered to some areas and gradually eroded and caused clogging, causing extremely troublesome mechanical and physical problems.

The present invention is the result of intensive research in view of the above reasons.

” Succeeded in solving both of the two disadvantages at once, - It was equipped with the function of coating each item twice, and it did not create any risk of causing any trouble to the transfer device. The purpose of the present invention is to create and provide a powder coating device that can provide highly accurate and stable coating on coated surfaces without causing any damage.

To the small article of the present invention that achieves this purpose/! An example of the 11-equipment device will be described below with reference to the drawings. Fig. 1 is a schematic perspective view showing the entire coating device of the present invention, and Fig. 2 shows a circulating powder transfer tank device with a U-shaped concave section in cross section, without detracting from the main parts of the present invention. FIG. 1 is an enlarged partially cutaway view of a conveyor belt that has been turned over.

The structure of the present invention is that there is a chute 2 at the end of the delivery side.
Rotates endlessly inside the tunnel furnace 4 with
An article transfer device 1, and (2) a circulating powder transfer tank device 5 in which at least the end side of a dam is located at the point where the article falls, and (2) a spray charge 7 is additionally provided.

At the bottom of the tip of the transfer tank equipment 5, there is a vibrating net floor 11 for sieving the coated articles and the powder outlet, and a powder container 1.
5 to 5, a powder coating device for small articles comprising a tS article equipped with a circulation vibrator 12 for circulating the powder coating material and a device indicated by the five circle symbols and numbers above of the powder collection mechanism 13. The gist of this is that the conveyor belt 6 of the circulating powder transfer tank device 5 is formed into a powder tank with a U-shaped concave cross section, and an external blower 10 is provided on the lower side, and a ventilator is provided on the top surface. An air chamber 8 is formed by a frame 7 provided with pores 9.
The present invention is characterized in that it is assembled into the five devices described above so that an air film layer opening can be formed between the conveyor belt and the air chamber.

The configuration of the present invention will be explained in more detail.

An article transfer device 1 has a chute 2 at the end of the delivery side and rotates in a tunnel-type furnace 4 in an endless manner.

- A supply hopper A for the workpiece A is arranged above the side edge, and the supplied article A is transferred from the transfer device bells 1 to 1.
Arrange them in order so that they do not overlap on the same surface. In this case, it goes without saying that it may be done manually, but a linear feeder may also be installed. Then, the article A is successively heated in the tunnel furnace 4 and advances to the lower side of the tip of the transfer device 1.
The cross section is U, with the end side located in a state where it overhangs at least without a dam.
The powder is sent through the chute 2 to a circulating powder transfer tank device 5 of a conveyor belt formed in the shape of a concave belt. A plurality of frames 3 whose respective lengths are gradually shortened are provided on the surface of the chute through which the articles are sent out, and the drop point of the article to be processed is adjusted. Further, at this sending point, there is a net floor 14 formed with the vibration generator installed therein.
A powder spraying device [11] comprising a powder container 15 and a powder collection and supply mechanism 13 connected to a pipe 12 for circulating the powder is installed. This powder collection and supply mechanism 13 is connected to the end of a belt tank 6 whose cross section is formed into a U-shaped concave belt shape of the circulating powder transfer tank device 5 to which the air film layer opening is attached. Powder is constantly supplied. The powder transfer tank device 5 with the air film layer opening is transferred from the lower side of the tip of the article transfer device 1 to the net floor 14 having a vibration mechanism disposed at the lower side of the tip of the transfer tank device 5. The present invention is constructed in an endless manner.

The present invention is characterized in that the conveyor belt 6 of the circulating powder transfer tank device 5 is formed into a powder tank with a U-shaped cross section, and an external blower IO is provided on the lower side of the belt for ventilation. This apparatus is characterized in that an air chamber 8 is formed by a frame 7 having pores 9 on its upper surface, and an air membrane layer opening is formed between the conveyor belt and the air chamber.

With this configuration, the workpiece I can
It is heated in a tunnel type furnace 4 by the transfer device 1, and is sequentially sent to the circulating transfer tank device 5 whose end side is located at the lower side of the tip of this transfer device. At the same time, the powder coating material is sprayed (one time) by the spraying device [11], and a shock is applied to the powder coating material in the powder transfer tank device 5, bell 1, and tank 6, which has an air film layer port. The paper is dropped as if it were not a reply, is coated (second time) while being buried, and is transferred to the net floor 14. In this case, if the conveyor belt is normally used, the powder coating material sprayed by the spraying device 11, sinking leakage within the belt that occurs during powder transfer, or physical rotational vibration of the belt, etc. As a result, powder particles continue to adhere to the drive part with a slight layer on top and to parts of each gear, causing clogging, which causes mechanical and physical troubles, making cleaning work extremely difficult. However, the powder transfer tank device 5 constituting the gist of the present invention
Air is blown from the external blower 10 to the air chamber 8 in the frame 7, and is further blown from the ventilation holes 9 provided on the top surface of the air chamber, forming an air film between the conveyor belt 6 and the air chamber 8. Since a layer opening is obtained, the powder coating material leaks downward or falls due to vibration, etc. The present invention has created a powder transfer tank device that can reliably eliminate the above-mentioned drawbacks such as drying and scattering.

Then, the articles are further separated from the powder by the vibration of the throat bed 14 and sent to the product recovery surface 16.

On the other hand, the sieved powder is collected into the powder container 15 on the net bed 14, and fluidly circulated by the circulation vibrator 12 to the spraying device 11 equipped with the powder collection and supply mechanism 13. This is the mechanism by which this is done.

Therefore, at least the conveyor bell 1-6 forming the U-shaped concave belt shape of the powder transfer tank device 5 and the peripheral portion of the spray device 11 that sprays when the article falls are covered with a cover sheet. It is also characterized by being covered with etc.

That is, by using the transfer tank device carrying the air film layer of the present invention, we have succeeded in greatly reducing vibrations generated when the conveyor belt rotates, as well as the shaking off of powder due to shaking. It is also characterized in that there is no need to take large-scale blocking measures to prevent dust from flying up, and the present invention simply installs the spray area of the powder paint and the net floor. It has a simple characteristic of just covering the surrounding area. As described above, the apparatus for powder coating small articles of the present invention has originality that does not belong to the apparatus and method of either the above-mentioned Japanese Patent Publication No. 52-22649 or Japanese Patent Application Laid-open No. 57-110370. In the best condition, this air film layer is sprayed when the workpiece is heated and falls, and the adhering powder coating inevitably melts and becomes sticky from a macroscopic perspective. The two-time coating method, in which the powder is deposited in the powder transfer tank and then further coated, is extremely rational, and it is possible to reliably obtain a uniform and high-grade coating surface, and it is This more than satisfies the demand for high precision, and together with its contribution, the present invention can produce extremely significant effects.

[Brief explanation of drawings]

FIG. 1 is a perspective view schematically showing the entire coating apparatus of the present invention, and FIG. It is a partially cutaway enlarged view showing an air film layer by cutting away a front part. B. Processed articles. μ: Air film layer, C: Powder. 1 Article transfer device, 2... Chute, 4... Tunnel type furnace, 5... Circulating powder transfer tank device, 6... Belt tank with a U-shaped concave cross section, 7... Frame body, 8...・Air chamber, 9・
Ventilation pores, 10... External blower, 1]... Powder spraying device, 12... Pipe, 13... Supply device, 14...
・Net floor with vibration device, 15...Powder container, 16...
・Product recovery aspect. A. Goods supply hopper. Patent Applicant Kobayashi Co., Ltd. Representative Director Satoshi Kobayashi 2nd 1st

Claims (1)

[Scope of Claims] 1. An article transfer device that has a chute at the end of the delivery side and rotates endlessly in a tunnel furnace, and at least the end side is located at the point where the article falls. In addition, there is a circulating powder transfer tank equipped with a spraying device, and a vibrating net floor at the bottom of the tip of the transfer tank, which is equipped with a function to sieve the painted articles and powder and a powder collection mechanism. In a powder coating apparatus for small articles consisting of five parts, the conveyor belt of the circulating powder transfer tank apparatus has a cross section of U.
It is formed into a concave band-shaped powder tank, and furthermore, an air chamber is formed by a frame body equipped with an external blower and ventilation holes on the lower side, and an air film layer is provided between the conveyor belt and the air chamber. An apparatus for powder coating small articles, characterized in that it is constructed as obtained and incorporated into the apparatus configuration consisting of the five parts described above. 2. At least the weir constituting the above U of the powder transfer tank device
A powder coating device for small articles according to claim 1, comprising a conveyor belt forming a concave belt shape and a peripheral portion of a spraying device installed side by side that sprays the article when it falls, covered with a cover sheet or the like. .