JPH03204114A - Coating device for inside surface of pipe - Google Patents

Abstract

PURPOSE:To coat the inside surface of the metallic pipe without unevenness by inserting the coating member of column like felt material whose diameter is a specific % larger than the inside diameter of metallic pipe from the one end opening part of metallic pipe, spouting the pressurized gas and moving the coating member to the other end. CONSTITUTION:The column like coating member 15 of felt material is formed 3 - 6 % larger than the inside diameter of metallic pipe 1, impregnated with the liquid coating agent 8 and inserted into one end part 1a of the metallic pipe 1. And the air-gun 17 is inserted into the opening and the compressed air 16 is supplied. Therefore, the coating member 15 is moved to the other end part 1c by being pressed with the compressed air while coating the inside surface 7 with the coating agent 8, pushed out from its other end part 1c and drops in the collecting vessel 18. In such a way, to coat the inside surface of metallic pipe with the coating agent without unevenness can be executed.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention provides a method for applying a liquid coating to the inner circumferential surface of a metal tube in order to improve the drawing performance of the manufactured drawn tube in the cold drawing process of metal tubes. The present invention relates to a tube inner surface coating device used for applying a coating agent.

[Prior Art] Generally, a method shown in FIGS. 3 and 4 is used to manufacture a bowed tube of a predetermined shape by cold drawing.

The metal tube l used as the drawing material is made of Ni or C.
It is made of an alloy containing u. In order to manufacture a drawn tube 1b from this metal tube 1, the metal tube 1 is inserted into the drawing opening 3 of the die 2, and the floating plug 4 is locked at a position corresponding to the drawing opening 3. By screwing the end portion 1a into a threaded portion formed on the chuck le and pulling the chuck le in six directions in the figure, a small-diameter drawn pipe 1b is manufactured.

[Problems to be Solved by the Invention] By the way, when manufacturing the drawn tube 1b from the metal tube 1 using the above-mentioned die 2 and floating plug 4, the die 2 and the floating plug 4 that come into contact with the metal tube 1 are Since a large frictional resistance is generated between the two, there is a risk that the metal tube 1 and the drawn tube 1b to be manufactured may be twisted, or that the metal tube 1 may be cut during the drawing process. Therefore, in order to reduce the frictional resistance at the contact portion, lubricating oil 6 is applied to the outer circumferential surface 5 of the metal tube l during the drawing process, and
A liquid coating agent 8 is applied in advance to the inner circumferential surface 7 of the metal tube 1 to reduce frictional resistance, so that normal drawing can be performed.

Here, the work of applying the coating agent 8 to the inner surface 7 of the metal tube 1 is carried out using a coating member made of solid gauze, sponge, etc. that is larger than the inner diameter of the metal tube 1 at one end of the string 9, as shown in FIG. A combination of 9 is used. In this operation, first, the string 9 is passed from the other end 1c of the metal tube l and the other end of the string 9 is brought out to the one end 1a. Next, after impregnating the application member 10 with the coating agent 8, the other end of the string 9 is pulled to contract the application member 10 and draw it from the other end 1c of the metal tube l, thereby applying the coating agent 8 to the metal tube. It is applied to the inner surface 7 of 1.

Note that the reference numeral 11 is a pedestal on which the metal tube I is placed.

However, there is a problem in that the work of applying the coating agent 8 to the inner surface 7 of the metal tube 1 requires a lot of effort and time.

Furthermore, when the gauze or sponge used as the application member 9 is pushed into the metal tube l, the impregnated liquid coating agent 8 is immediately applied to the lower part of the gauze or sponge (the inner surface of the metal tube l). Since the coating agent 8 has a weak retention ability, there is a risk that the amount of the coating agent 8 will run out during the coating process.

Moreover, this applicator 9 is easily worn out while moving on the inner surface 7 of the metal tube 1, and the applicator 9, which has a diameter smaller than the inner diameter of the metal tube 1 due to wear, evenly coats the inner surface 7 of the metal tube 1. It is impossible to do so.

Furthermore, when the coating agent 8 stuck to the coating member 9 is removed with a non-nerg or the like after the work, there is a risk that the coating member 9 itself may deteriorate.

The present invention aims to solve the above problems.

[Means for Solving the Problems] The tube inner surface coating device of the present invention performs cold drawing on a metal tube as a raw material using a die and a floating plug to produce a drawn tube with a smaller diameter than the raw material. A tube inner surface coating device used for applying a liquid coating agent to the inner peripheral surface of the metal tube, the device being made of a cylindrical felt material, the diameter of which is 3 to 6 mm larger than the inner diameter of the metal tube. % larger diameter and is impregnated with a coating agent and inserted into the opening at one end of the metal tube; and a coating member disposed at the opening at one end of the metal tube and blowing out pressurized gas. The device is characterized in that it is equipped with a pressurizing means for moving the end to the other end.

[Function] According to the pipe inner surface coating device of the present invention, the coating member made of felt material sufficiently impregnates the coating agent between the densely packed bristles on the surface thereof, and is coated by the jetting force of the supplied compressed air. By gradually moving the impregnated coating agent to the tip of the bristles, the inner surface of the metal tube can be evenly coated with a plurality of highly elastic bristles like a brush.

In addition, the coating member made of felt material has excellent wear resistance and does not easily shrink in diameter even when passed through the inside of the metal tube, so it is possible to uniformly apply the coating agent to the inner surface of the metal tube. Can be applied.

[Example] Fig. 1 and Fig. 2 show an embodiment of the tube inner surface coating device of the present invention, and the same components as those shown in Fig. 3 and Fig. 4 are given the same reference numerals. Therefore, the explanation will be omitted.

A feature of the tube inner surface coating apparatus of the present invention is that a felt material is used as the coating member, and compressed air or the like is applied as means for moving the coating member from one end 1a to the other end IC inside the metal tube 1. A pressurizing means that blows out pressurized gas is used.

FIG. 1 shows the operation of applying a coating agent 8 to the inner surface 7 of a metal tube 1, and reference numeral 15 in the figure is a cylindrical application member made of felt material. This application member 15 is
It is made of wool (approximately 70% of the total) mixed with a small amount of nylon or polyester, and its entire surface is densely packed with multiple hairs that are highly elastic and have excellent abrasion resistance. . Here, the diameter of this application member 15 is formed to be 3 to 6% larger than the inner diameter of the metal tube l. This coating member 15 is impregnated with a liquid coach ink agent 8 made of a plastic resin mixed with a coating material, and is inserted into one end 1a of the metal tube l.

Furthermore, an air gun (pressurizing means) 17 is inserted into one end 1a of the metal tube l for supplying pressurized gas 16 such as compressed air from its opening to the opening at the other end 1c. (See Figure 2). The coating member 1 that has passed through the inside of the metal tube 1 and has been pushed out is attached to the other end 1c of the metal tube 1.
A collection container 18 for collecting 5 is provided.

Using the tube inner surface coating device with the above configuration,
To apply the coating agent 8 to the inner surface 7 of the metal tube l,
First, the coating member 15 is impregnated with the coating agent 8, and the coating member 15 is inserted into the opening of one end 1a of the metal tube l. Then, insert the air gun 17 into the opening,
Compressed air 16 is supplied. As a result, the application member 15 is pressed by the compressed air and moves toward the other end IC side while applying the coating agent 8 to the inner surface 7.
c and falls into the collection container 18.

Here, the metal tube l coated with the liquid coating agent 8 is
The inner surface 7 of the inner surface 7 is dried to form a uniform coating, which allows the drawing operation as shown in FIG. 3 to be carried out normally.

By the way, the application part flat plate 15 made of the above-mentioned felt material
The coating agent 8 is sufficiently impregnated between the densely packed hairs on the surface, and the coating agent 8 is gradually moved to the tips of the hairs by the jet force of the supplied compressed air 16, thereby improving the elasticity. The inner surface 7 of the metal tube 1 can be evenly coated with a plurality of bristles rich in color like a brush.

Second, the coating member 15 made of felt material has excellent wear resistance and does not easily reduce in diameter even when passing through the inside of the metal tube 1. The coating agent 8 can be applied uniformly to the surface.

Furthermore, compressed air 16 is applied to the applicator 15 inserted into one end 1a of the metal tube 1 and impregnated with 1 nicoating agent.
Because it only ejects and moves, work efficiency is greatly improved.

Note that the pressure value of the f2 compressed air 16 mentioned above is 1
, 0-3, 0 kg/am' (gauge pressure). This is the optimum pressure value for the application member 15 to efficiently apply the coating agent 8 to the inner surface 7 of the metal tube 1 and move.

Further, the corresponding value between the diameter of the application member 15 and the inner diameter d of the metal tube l is as follows.

Diameter of coating member D (mm) Inner diameter of metal tube d (mm
)25 26.5 26 27.5 27 28.5 28 29.5 29 30.0 [Effects of the Invention] As explained above, according to the tube inner surface coating apparatus of the present invention, the application member made of felt material By fully impregnating the coating agent between the densely packed bristles on the surface, and gradually moving the coating agent to the tips of the bristles using the jet force of the supplied compressed air, the highly elastic The bristles can be used to evenly coat the inner surface of metal tubes like a brush.

In addition, the coating member made of felt material has excellent wear resistance and does not easily shrink in diameter even when passed through the inside of the metal tube, so it is possible to uniformly apply the coating agent to the inner surface of the metal tube. Be able to apply it.

Furthermore, since the work is completed by simply blowing out pressurized gas and moving the application member impregnated with the coating agent inserted into one end of the metal tube, work efficiency can be greatly improved.

[Brief explanation of drawings]

Figures 1 and 2 show an embodiment of the coating device for the inner surface of a pipe according to the present invention. FIG. 3 is a cross-sectional view showing the cold drawing process, and FIG. 4 is a schematic view showing the conventional process of applying a coating agent to the inner surface of a metal tube. It is. 8... Coating agent, 5... Application member, 16... Compressed air (pressurized gas), 17...
Air gun (pressurizing means).

Claims (1)

[Scope of Claims] When a raw metal tube is subjected to cold drawing using a die and a floating plug to produce a drawn tube of a predetermined shape with a smaller diameter than the raw material, the inner circumferential surface of the metal tube is This is a tube inner surface coating device used for applying a coating agent to a metal tube, and is made of a cylindrical felt material, the diameter of which is 3 to 6% larger than the inner diameter of the metal tube, and is used to apply a liquid coating agent to the metal tube. a coating member impregnated and inserted into an opening at one end of the metal tube; and a coating member disposed at the opening at one end of the metal tube and moving the coating member to the other end by jetting out pressurized gas. A tube inner surface coating device characterized in that it is equipped with a pressurizing means.