JP2555183B2 - Inner surface processing heat transfer tube manufacturing method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for manufacturing an inner surface processed heat transfer tube having grooves on the inner surface in a fixed direction.

"Prior Art" A method for manufacturing a heat transfer tube of this type is described in, for example, Japanese Patent Laid-Open No. 54-3705.
As disclosed in Japanese Patent Publication No. 9-A, while giving axial feed to the raw pipe by pulling out, a plug having a predetermined groove is inserted into the raw pipe prior to the pulling, and the outer circumference of the raw pipe is A method of pressing with a plurality of planetary rotating rollers has been proposed.

Further, as disclosed in, for example, Japanese Patent Application Laid-Open No. 55-43360, while continuously feeding a metal strip having a constant width, the metal strip is sandwiched between a groove processing roll and a rolling roll. A groove is formed on the surface of the metal strip, and the metal strip is formed into a tubular shape by a forming roll group in a state where the groove is the inner surface,
There is a method of welding the opposite sides that are facing each other.

"Problems to be solved by the invention" Recently, due to the demand for smaller and lighter heat exchangers, the inner surface processed heat transfer tube has a tube outer diameter of 10 mm or less and a wall thickness of 0.
Although a thin pipe with a small diameter of 3 mm or less is required,
Of the conventional manufacturing methods, when manufacturing such a thin and small diameter heat transfer tube by the former method, it is necessary to manufacture a large diameter and thick tube into a small diameter and thin tube by drawing many times. However, there is a problem that the manufacturing cost of the raw pipe increases. Further, according to this method, the pipe is drawn out if the diameter reduction process and the pipe internal groove process are performed at the same time, so that the drawing force is remarkably increased, and the pipe is easily broken when manufacturing a small diameter thin wall heat transfer pipe. Moreover, it is difficult to form a groove having a deep and sharp shape.

On the other hand, when the latter of the above-mentioned conventional methods is used, there is no problem like the former, but the groove on the inner surface becomes discontinuous due to the bead generated at the welded portion, and the heat transfer performance of the heat transfer tube tends to be directional. When it is installed in the exchanger, it becomes necessary to consider this directionality. Also, when installing the heat transfer tube in the heat exchanger,
The portion of the heat transfer tube is expanded through the hole of the tube plate and fixed to the tube plate. At the time of this tube expansion, the beads are separated and the metal powder adheres to the inside of the tube. Further, this manufacturing method has a problem that when the above-mentioned grooves or protrusions are formed and then formed into a tubular shape by a group of forming rolls, the grooves or protrusions on the surface are crushed or deformed due to pressure of the forming rolls.

An object of the present invention is to provide a method for manufacturing an inner surface processed heat transfer tube, which solves the above problems.

[Means for Solving the Problems] In order to achieve the above-mentioned object, one of the methods of the present invention is to manufacture a raw pipe by forming a continuously fed metal strip into a tubular shape and then welding the abutted opposite sides. Then, a rod is inserted into the element pipe from a portion where the metal strip is being formed into a tubular shape, and a plug having a predetermined groove on a peripheral surface is held in a portion of the rod located inside the element pipe, While moving the tube in the same direction as the feeding direction of the metal strip, the outer periphery of the plug insertion position of the element tube is pressed by several rollers or balls that planetarily rotate about the axis of the element tube. Adopted.

In addition, another one of the methods of the present invention is, in order to achieve the above-mentioned object, after forming a continuously fed metal strip into a tubular shape, and welding the abutted opposite side edges to produce a raw tube. While moving the pipe in the same direction as the feeding direction of the metal strip, the diameter is reduced by passing through a die, and the rod is inserted into the reduced diameter pipe from the portion where the metal strip is being formed into a tubular shape,
A plug having a predetermined groove on its peripheral surface is held on a portion of the rod that is located inside the reduced diameter tube, and the outer periphery of the plug insertion position of the reduced diameter tube is rotated by several planets about the axis of the tube. A structure in which pressure is applied by rollers or balls is adopted.

When the groove of the plug is formed in a spiral shape with respect to the central axis, the plug is rotatably held by the rod.

"Operation" In the manufacturing process of the raw pipe, by selecting the metal strip with the desired thickness and width, it is possible to easily and continuously produce the raw pipe with the desired thickness and diameter. By continuing the above process, the raw pipe supply work is omitted.

[Examples] Preferred examples of the method of the present invention will be described below with reference to the drawings.

From an uncoiler (not shown), a metal strip 1 made of copper, aluminum, an alloy thereof, or another metal is continuously fed out at a constant speed in a certain direction as shown in FIG. 1 by an appropriate means.

In this embodiment, a metal roll 1 made of copper having a thickness of 0.3 mm and a width of 28 mm is fed at a speed of 50 m / min while forming roll groups.
By 10 to 13, the metal strip 1 is rolled in the width direction and gradually formed into a tubular shape.
It is eluted by IG and other suitable welding means to continuously produce a blank tube 9a with an outer diameter of about 9 mm, and the squeeze roll 1
The element pipe a is continuously supplied to the next inner surface processing apparatus 3 while being shaped by 4,14.

A supporting arm 40 is suspended from above at a suitable position of the portion where the metal strip 1 is formed into a tubular shape, and the rod 4 in a state of being inserted into the inside of the raw pipe a manufactured as described above is fixed to the supporting arm 40. At the same time, as shown in FIG. 2, the rod 4 is rotatably held by the rod 4 so as to be located inside the portion of the raw pipe a which has reached the inner surface processing device 3.

Before the raw material pipe a is supplied to the inner surface processing apparatus 3, it is preferable that the bead cutter 5 removes the bead on the outer surface generated by welding, and the material tube a is passed through an appropriate cooling device 6 to be cooled to room temperature.

As shown in FIG. 2, the inner surface processing apparatus 3 has a housing 30.
A spindle 31 is provided via a bearing 32, and a roller holder 33 is attached to the tip of the spindle 31. Several roller holders 33 are equiangularly centered around the axis of the raw pipe a supplied inside. Install the roller 34 of.

The spindle 31 is rotated in a fixed direction via a belt 35 by a drive device (not shown), and each roller 34 is planet-rotated about the axis of the raw tube a while each roller 34 is rotated.
To press the raw pipe a to the internal plug 41, and to pull and move the raw pipe a in the same direction as the feeding direction of the metal strip 1.
The heat transfer tube c having the groove c1 on the inner surface is continuously manufactured.

This heat transfer tube c is passed through a molding die (not shown) (preferably provided continuously to the inner surface processing device 3) to adjust the outer diameter, and the wall diameter of the outer diameter of 7.94 mm and the groove bottom of c1 is 0.2 mm. Finished and wound into a coil or cut to an appropriate size.

FIG. 3 shows an example of an inner surface processing apparatus for explaining another embodiment of the method of the present invention, which is located in front of the housing 30 in front of the grooved plug 41 and the roller 34. The dice holder 36 is provided, and this dice holder
The die 37 for emptying is held by 36, and the raw pipe a produced continuously by the same method as above is continuously supplied to the die 37.
And then reduce the diameter of the reduced diameter tube b to produce the reduced diameter tube b, and then the inner surface of the reduced diameter tube b is processed by the plug 41 and the roller 34.
The heat transfer tube c having the groove c1 on the inner surface is manufactured.

The other structure of this manufacturing method is the same as the example described with reference to FIG.

In each manufacturing method according to the present invention, as shown in FIG. 4, a ball holder 38 is fixed to the spindle 31 instead of the roller 34, and a plurality of idle balls 39 are held in the holder 38. Spindle 31
It is also possible to make a configuration in which the base tube a or the diameter-reduced tube b is pressed against the grooved plug 41 while the ball 39 is rotated in a planetary manner by rotating in a fixed direction.

In addition, in each of the above-described embodiments, the plug 41 is connected to the rod 4
Although it is rotatably attached to the rod 41, the plug 41 can be fixed to the rod 4 as long as the groove on the surface of the plug 41 is a straight line parallel to the central axis thereof.

Further, in each of the above methods, the grooved plugs 41 are provided at two front and rear positions in the drawing direction, and the rollers 34 or the balls 39 are provided at the front and rear two positions corresponding to the respective plugs. It can also be implemented by pressurizing a tube or a reduced diameter tube to the plug.

"Effect of the invention" The method of manufacturing an inner surface processed heat transfer tube according to the present invention does not require drawing in the raw tube manufacturing step, thereby reducing the drawing force and easily manufacturing a heat transfer tube having a smaller diameter and a thinner wall. The rod of the plug is passed through the raw pipe or the reduced-diameter pipe that is being produced from the molding part of the metal strip so that the raw pipe manufacturing and the inner surface processing are continued, and the raw pipe supply is continuous at the same time as the raw pipe manufacturing. Since it is unnecessary to repeat the supply of the raw pipe, the manufacturing cost can be further reduced.

Further, since the groove or the protrusion is processed after forming the raw pipe, the groove or the protrusion is not crushed or deformed.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of an apparatus for a manufacturing process of a raw pipe in the method of the present invention, FIG. 2 is a sectional view showing an example of an apparatus for an inner surface processing step, and FIG. 3 is another manufacturing method of the present invention. FIG. 4 is a cross-sectional view showing an example of an apparatus for the inner surface processing step, and FIG. 4 is a partial cross-sectional view illustrating another apparatus for carrying out each manufacturing method according to the present invention. Description of main symbols in the figure 1 is a metal strip, 10 to 13 are forming roll groups, 2 is welding means,
3 inner surface processing device, 31 is a spindle, 33 is a roller holder, 34 is a roller, 38 is a ball holder, 39 is a ball,
4 is a rod, 40 is a support arm, 5 is a bead cutter, a
Is a blank tube, b is a reduced diameter tube, c is a heat transfer tube, and c1 is a groove or protrusion on the inner surface of the heat transfer tube.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tomoshige Okawa 2-6-1, Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd. Luminium Kogyo Co., Ltd. (56) Reference JP 61-42419 (JP, A) JP 64-112094 (JP, A) JP 61-140309 (JP, A) JP 62- 263821 (JP, A)

Claims (3)

(57) [Claims] 1. A continuous strip of metal strip is formed into a tubular shape, and the abutted side edges are welded together to produce a raw tube.
A rod is inserted into the raw pipe from a portion where the metal strip is being formed into a tubular shape, and a plug having a predetermined groove is held on a peripheral surface of a portion of the rod located in the raw pipe.
While moving the element pipe in the same direction as the feeding direction of the metal strip, the outer periphery of the plug insertion position of the element tube is pressed by several rollers or balls which planetarily rotate about the axis of the element tube. A method for manufacturing an inner surface processed heat transfer tube, which is characterized by the above. 2. A continuous strip of metal strip is formed into a tubular shape, and then both sides of the butted side are welded together to produce a raw tube,
While moving this element tube in the same direction as the feeding direction of the metal strip, the diameter is reduced by passing through a die, and the rod is inserted into the reduced diameter tube from the portion where the metal strip is being formed into a tubular shape, A plug having a predetermined groove on its peripheral surface is held on a portion of the rod that is located inside the reduced diameter tube, and the outer periphery of the plug insertion position of the reduced diameter tube is rotated by several planets about the axis of the tube. A method for manufacturing an inner surface processed heat transfer tube, which comprises pressurizing with a roller or a ball. 3. The plug is rotatably held by the rod, and the groove on the peripheral surface of the plug is formed in a spiral shape.
The method for manufacturing the inner surface processed heat transfer tube according to claim 1.