JPS6125660A - Coating device - Google Patents

Abstract

PURPOSE:To coat the outer surface of an object uniformly without the intrusion of the coating liquid into the inside of the object by providing a sealing device that expands and contracts corresponding to the injection of pressurized air and deairing in and from the hollow of the object to be coated. CONSTITUTION:A frame 31 to which an elastic sealing material 32 consisting of rubber tube etc. is airtightly inserted into the hollow 20 of the object to be coated, and pressurized air 33 is injected into an inside space 34 from the end 311 of the frame 31. Then, the sealing material 31 expands and thrusted against the wall face 21 of the hollow and is abutted on the inner wall face 21 liquid-tightly. Thus, the object 2 is connected with the frame 31 and supported. By descending the frame 31 in a receiving tank 1 under this condition, the object 2 is immersed into the coating liquid 11 keeping the inside liquid-tightly. After coating, the body can be removed by pulling up the frame 31 and releasing pressurization.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a dip coating apparatus, and more particularly, to a coating apparatus that can uniformly coat the outer surface of a hollow object to be coated without allowing a coating liquid to penetrate into the hollow space. Regarding.

(Prior Art) In the round coating method in which a hollow object to be coated, such as a cylindrical drum, is immersed in a coating liquid and its outer peripheral surface is coated, it is necessary to prevent the coating liquid from penetrating into the drum. For this purpose, as shown in Figure 5.

A lid 201 is provided at the bottom of the drum 200. However, in order to continuously coat the drum 200, attaching and detaching the lid 201 requires time and effort. Moreover.

It is necessary to clean the lid 201 after each process. Therefore, the coating operation is extremely inefficient.

Moreover, in this method, the drum is immersed in the coating liquid,
Further, a drum support means must be provided separately for lifting the drum, making the device complicated.

(Object of the Invention) An object of the present invention is to provide a coating device that can uniformly coat the outer surface of a hollow object to be coated without allowing the coating liquid to penetrate inside the object. Another object of the present invention is to provide a coating device in which means for preventing the coating liquid from entering the hollow cavity of the object to be coated can also serve as means for supporting the object to be coated. Still another object of the present invention is to provide a coating device that is easy to operate and can form a coating layer at low cost.

(Structure of the Invention) The coating device of the present invention is a device for immersing an object to be coated in a coating liquid in a coating liquid storage tank and applying the coating liquid to the object to be coated. Sealing means are disposed within the cavity that can expand and contract in response to the injection and degassing of pressurized air, thereby achieving the above object.

(Example) The present invention will be described below with reference to examples.

As shown in FIGS. 1 and 2, the coating device of the present invention has the following features:
It has a coating liquid storage tank 1 and a sealing means 3 arranged in a hollow cavity 20 of an object to be coated 2 such as a cylindrical drum. The storage tank 1 stores a coating liquid 11. The sealing means 3 includes a frame 3 and an elastic sealing material 32 held in the frame 31 in an airtight manner.
It consists of One end 311 of the frame 31 is connected to an external pressurized air supply means (not shown), and the other end 312 is open within the cavity 20 of the object to be coated. This opening 313 is provided over the circumferential surface of the hollow inner wall surface 21 .

The elastic sealing material 32 is held in this opening 313 in an airtight manner.

When pressurized air 33 is injected from one end 311 of the frame 31 into the space 34 formed by the frame 31 and the elastic sealing material 32, the elastic sealing material 32 is forced into the hollow space by the pressure of the pressurized air 33. It expands toward the wall surface 2I and comes into contact with the hollow inner wall surface 21 in a liquid-tight manner (a state in which no liquid enters).

The elastic sealing material 32 is, for example, a cylindrical rubber tube.

Another example of the sealing means 3 is shown in FIGS. 3 and 4. Here, the other end 312 of the frame 31 is connected to the hollow 2 of the object to be coated.
0, openings 313 are provided along the inner wall surface 21 only at at least the upper and lower ends of the inner wall surface 21. The elastic sealing material 32 has a ring shape and is held in the opening 313 in an airtight manner. When the pressurized air 33 is injected into the space 34, the elastic sealing material 32 similarly expands along the hollow inner wall surface 21 in the direction of the inner wall surface 21 and at least near the upper end and lower end of the inner wall surface 21. It comes into liquid-tight contact with the

Needless to say, each of the elastic sealing materials 32 described above has elasticity and strength sufficient to withstand the pressure of the pressurized air 33 and the frictional force with the object 2 to be coated, and is insoluble in the coating liquid 11. Nor.

The shape of the storage tank 1 is not particularly limited. Its volume is
In order to reduce movement of the coating liquid surface due to taking in and out of the object to be coated, it is preferable that the volume is large relative to the external volume of the object to be coated. The material may be any material as long as it is insoluble in the coating solution2.Aluminum, stainless steel, or synthetic resin is usually used.

The object to be coated only needs to be hollow, and its cross-sectional shape, cross-sectional size, length, material, etc. are not particularly limited. For example, in the case of a drum used for an electrophotographic photoreceptor, aluminum having a cylindrical shape is used.

Dip coating is applied to the object to be coated 2 using the above-mentioned apparatus in the following manner. First, the frame 31 with the elastic sealant 32 airtightly mounted thereon is inserted into the hollow 20 of the object to be coated.

Then, pressurized air 33 is injected into the frame space 34 from one end 311 of the frame 31. The sealing material 31 expands and is pressed against the inner wall surface 21 of the hollow cavity, so as to contact the inner wall surface 21 in a liquid-tight manner. As a result, the object 2 to be coated is connected and supported by the frame 31. The object 2 to be coated is immersed in the coating liquid 11 in the storage tank 1 by pulling down the frame 31. Since the pressurized state of the sealing means 3 is maintained continuously, the sealing material 3
2 seals the inner wall surface 21 of the cavity of the object to be coated in a liquid-tight manner;
As a result, the coating liquid 11 is prevented from penetrating into the hollow cavity 20. Next, the object 2 to be coated is removed from the coating liquid 11 by pulling the frame 31 upward.

Then, the object 2 to be coated on which the predetermined coating layer has been formed is removed from the frame 31 by releasing the pressurized state. The coating layer of the coated object 2 thus obtained is uniform. There is also little variation between lofts. Moreover,
Successive dipping operations can be performed quickly. It goes without saying that means for replenishing the coating liquid 11 into the storage tank 1 can be provided as appropriate.

The coating apparatus of the present invention is suitably used in fields where extremely fineness and high precision are required, such as the manufacture of photosensitive drums for electrophotography, but it can of course be applied to other fields as well.

(Effects of the Invention) According to the present invention, by arranging the sealing means that can be expanded and contracted by pressurized air in the hollow of the object to be coated, the inside of the object to be coated can be prevented from being coated with the coating liquid. It can definitely be prevented. Since the sealing means also has the function of supporting the object to be coated, there is no need to provide a separate supporting means.

As a result, the device has a simple construction and is extremely easy to operate. Continuous operation is also possible and can be carried out quickly. Therefore, coating can be done inexpensively.

[Brief explanation of the drawing]

1 and 2 are front sectional views of main parts showing one embodiment of the device of the present invention, and FIGS. 3 and 4 are front sectional views of main parts showing other embodiments of the device of the present invention, respectively. , 5th
The figure is a front sectional view of a main part showing an example of the conventional technology. 1, 100... Coating liquid storage tank, 2.200... Object to be coated. 3...Sealing means, 11.110...Coating liquid,
20... Cavity of object to be coated, 21... Inner wall surface of object to be coated, 31... Frame. 32... Elastic sealing material, 33... Pressurized air, 34...
··space. 201... Lid, 311 One end of the middle frame body, 312...
The other end of the frame. 313...Frame opening. that's all

Claims (1)

[Scope of Claims] 1. In an apparatus for immersing an object to be coated having a hollow cavity in a coating liquid in a coating liquid storage tank and applying the coating liquid to the object to be coated, the inside of the hollow of the object to be coated is A coating device in which a sealing means that can expand and contract in response to the injection and degassing of pressurized air is arranged. 2. The sealing means includes a frame body having one end connected to an external pressurized air supply means and the other end opening at least near the upper end and the lower end of the hollow inner wall surface of the object to be coated, and the frame body opening. The coating device according to claim 1, further comprising an elastic sealing material that is maintained in an airtight state. 3. The coating device according to claim 2, wherein the elastic sealing material is a rubber tube or a rubber packing.