JPH09314266A - Method and apparatus for manufacturing metal tube with internal groove - Google Patents

Abstract

(57) [Abstract] (Correction) [Problem] To prevent breakage of metal pipe, prevent increase of processing plug, and reduce management labor of manufacturing plug and reduction of manufacturing cost. A manufacturing method and an apparatus therefor are provided. SOLUTION: By moving the pipe in the direction of A while the plug unit 26 is inserted in the metal pipe 1, the pipe is rotated in a planetary manner at the position of the grooved plug 4, and the plurality of spheres 10 are rotated.
And is pressed against the grooved plug to continuously form the primary groove 20 and the fin 22 on the inner surface of the tube to form the primary grooved metal tube 12. Next, the tube is contracted by a plurality of balls 24 to form a primary grooved contracted tube 25. By further moving the fin portion, the fin portion is intermittently cut off by the protruding portion 7 of the protruding plug 6, and the secondary groove 21 is formed on the inner surface of the pipe.
Is formed, and the inner surface double-grooved metal tube 13 is formed. Furthermore, the finishing die 11 reduces the diameter to a predetermined outer diameter,
An inner double grooved metal tube 23 is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for manufacturing a metal tube having an inner groove, and more particularly to a method and an apparatus for manufacturing a tube having a plurality of different grooves on the same inner surface.

[0002]

2. Description of the Related Art Conventionally, copper or copper alloy bare tubes have been used as heat transfer tubes for heat exchangers. Recently, as the heat transfer tube for such a heat exchanger, an inner grooved metal tube having high heat transfer performance even for a fluid such as CFCs that changes in phase has been widely used.

Such a heat transfer tube for a heat exchanger is a metal tube with an inner surface groove having fine spiral grooves on the inner surface for improving the heat transfer performance, and recently, for improving the heat transfer performance, an inner surface groove is formed. It is a double metal tube with inner groove.

FIG. 2 shows an apparatus for producing a double-grooved inner surface metal pipe, which is one form of a conventional apparatus for producing a internally-grooved metal tube. This manufacturing apparatus rotates the outer peripheral surface of the metal tube 1 in a planetary shape in a direction orthogonal to the tube axis and applies a rolling pressure to the metal tube 1 in the radial direction on the outer peripheral surface to contract the metal tube 1. A plurality of spheres 10,
A drawing die 9 for locking the floating plug 2 inside the metal tube 1 is connected to the floating plug 2 by a connecting rod 3, and is inserted into the metal tube 1 in a freely rotatable state so that the ball 1
A grooved plug 4 having a groove 5 for processing a primary groove 20 and a fin 22 inside a metal tube 1 contracted by 0, and a double nut 8 on a connecting rod 3 behind the grooved plug 4 are installed. It is connected and inserted into the primary grooved metal tube 12 in a rotatable state, and the primary grooved metal tube 12 is pulled out in the downstream direction (the direction of arrow A) to thereby insert the primary grooved metal tube 12 into the inside of the primary grooved metal tube 12. Plug 6 with a protrusion having a protrusion 7 for processing the next groove 21
And a finishing die 11 for finishing the metal pipe 13 having a double groove formed on the inner surface thereof into an inner surface double grooved metal pipe 23 having a predetermined outer diameter.

That is, the metal tube 1 is moved from left to right (arrow A in FIG. 2).
Direction), the metal tube 1 is contracted by the plurality of spheres 10 that rotate in a planetary manner at the position of the grooved plug 4 and pressed against the grooved plug 4, and the metal tube 1 is continuously attached to the inner surface of the metal tube 1. The primary grooves 20 and the fins 22 are formed on the surface, and the metal tube 12 with primary grooves is formed. Next, the diameter of the projecting plug 6 to the apex of the projecting portion 7 is larger than the inner diameter of the fin 22 (projection) in the primary grooved metal tube 12 and the primary grooved metal tube 1 is provided.
Since the diameter of the primary groove 20 (recess) in 2 is smaller than the diameter of the primary groove 20 (recess), by moving the metal tube 12 with primary groove in the direction of arrow A in FIG. The fins 22 of the secondary grooved metal tube 12 are intermittently cut or crushed, and the secondary groove 21 corresponding to the shape of the protruding plug 6 is formed on the inner surface of the primary grooved metal tube 12, and the inner surface is formed. An inner double-grooved metal tube 13 having grooves 20 and 21 is formed. Further, the inner surface double-grooved metal tube 13 is reduced in diameter to a predetermined outer diameter by the finishing die 11 to form the inner surface double-grooved metal tube 23.

FIG. 3 shows another embodiment of the conventional apparatus for manufacturing a metal tube with a double groove on the inner surface. This manufacturing apparatus includes two rolling tools 30 and 31 for compressing a metal tube 1 in the radial direction by pushing the metal tube 1 in the radial direction, a drawing die 9 for locking the floating plug 2 inside the metal tube 1, and a floating plug. Groove 5 for processing primary groove 20 and fin 22 inside metal tube 1 which is connected to connecting tube 2 with connecting rod 3 and is rotatably inserted into metal tube 1 and contracted by rolling tool 30.
And a primary grooved plug 4 having a groove, which is connected to the rear of the primary grooved plug 4 by a connecting rod 3 and is inserted into the primary grooved metal tube 12 in a rotatable state to be contracted by a rolling tool 31. As a result, the secondary grooved plug 27 having the groove 28 for processing the secondary groove 29 is provided inside the primary grooved metal tube 12.

That is, the manufacturing apparatus includes the rolling tool 30,
31 are arranged in two stages, and the grooved plugs 4 and 27 connected to the floating plug 2 are arranged at the corresponding positions of the respective rolling tools 30 and 31, and the double grooved machining is continuously performed on the inner surface of the metal pipe 1. Was being done. Therefore, by moving the metal tube 1 from left to right (direction of arrow A), the metal tube 1 is contracted by the primary rolling tool 30 at the position of the primary grooved plug 4 and the primary grooved plug. It is pressed against 4 and continuously 1 on the inner surface
The secondary groove 20 and the fin 22 are formed, and then, in the same process, the secondary groove 29 is formed by the secondary rolling tool 31 and the secondary grooved plug 27. Therefore, the internal groove has the groove 20 and the groove 29. The inner surface double grooved metal tube 32 will be formed.

In this way, an inner double-grooved metal tube having high heat transfer performance was manufactured by the conventional manufacturing apparatus.

[0009]

However, according to the conventional inner surface double grooved metal pipe manufacturing apparatus as shown in FIG. 2, the primary grooved metal pipe 12 at the position of the protruding plug 6 is provided.
Since the diameter of the secondary groove 21 is already determined by the rolling radius of the sphere 10, when the depth of the secondary groove 21 is changed when forming the secondary groove 21 by the plug 6 with the protrusion, the depth of each secondary groove 21 is changed. It is necessary to have many types of plugs with protrusions whose outer diameters differ slightly depending on the size, and it is necessary to manufacture and manage many types of processed plugs according to the depth of the groove. There was a problem that the cost also increased.

Further, according to the conventional apparatus for manufacturing a double-grooved inner surface metal tube as shown in FIG. 3, a rolling tool 31 for rotating the outer peripheral surface of the primary grooved metal tube 12 and a grooved plug 27. Causes a large pulling force on the primary grooved metal tube 12,
Therefore, a large pulling force is required, and the wall thickness of the primary grooved metal tube 12 in the portion processed by the grooved plug 27 is reduced, so that the metal tube is easily broken.

Therefore, an object of the present invention is to separate the rolling pressure application portion and the working plug from each other, thereby reducing the tensile force with respect to the metal tube and the pulling force to prevent the metal tube from breaking, and By allowing the diameter of the metal pipe at the position of the plug to be adjusted freely, the depth of the groove on the inner surface of the metal pipe can be adjusted without changing the processing plug, preventing an increase in the number of processing plugs. An object of the present invention is to provide a method and an apparatus for manufacturing a metal pipe with an internal multi-groove, which can reduce management labor and manufacturing cost.

[0012]

In order to achieve the above-mentioned object, the present invention is designed to move a metal pipe in the pipe axial direction, and
A primary groove is formed on the inner wall surface by inserting a first processing plug that comes into contact with the inner wall surface of the metal tube in the subsequent stage of the position where the next groove is formed,
A metal pipe with a primary groove is contracted by applying a rolling pressure to the metal pipe with a primary groove and the inner wall surface of the metal pipe with a primary groove is contracted. Provided is a method of manufacturing a metal tube with an inner surface groove in which a second processing plug is inserted to form a secondary groove.

In order to achieve the above object, the first rolling pressure applying means for applying a rolling pressure to the outer circumference of the metal pipe and the inside of the position where the rolling pressure of the metal pipe is applied are provided. First groove processing means for contacting the inner wall surface to form a primary grooved metal tube having a primary groove on the inner wall surface, and rolling on the outer circumference of the primary grooved metal tube at a stage subsequent to the first groove processing means Second rolling pressure applying means for applying pressure to contract the primary grooved metal tube, and the compressed tube 1
Second groove processing means provided inside the metal tube with the next groove and contacting the inner wall surface of the metal tube with the primary groove contracted to form a metal tube with multiple grooves having secondary grooves. An apparatus for manufacturing a metal tube with an inner surface groove is provided.

That is, in the apparatus for manufacturing a metal tube with an inner surface groove of the present invention, a second rolling pressure applying means is provided before the second groove processing means,
Since the rolling pressure of the second rolling pressure applying means can be adjusted, the pulling force on the metal tube is reduced and the pulling out force is reduced to prevent the metal tube from being broken, and the position of the second groove processing means. It is possible to freely adjust the diameter of the metal pipe in, and to adjust the depth of the groove on the inner surface of the metal pipe without changing the processing plug that is the groove processing means, prevent the increase of the processing plug, It is possible to reduce the management labor and manufacturing cost of the plug.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The method and apparatus for manufacturing an inner grooved metal tube of the present invention will be described in detail below.

FIG. 1 shows an embodiment of the present invention. This device comprises a first rolling pressure application portion having working rings 14, 15, shims 16, and balls 10, and a grooved plug 4 having a groove 5.
A second rolling pressure applying portion having processing rings 17, 18, shims 19, and balls 24, a protruding plug 6 having a protruding portion 7, a floating plug 2, a connecting rod 3, and a drawing die 9. And it consists of finishing die 11.

The floating plug 2 is obtained by passing the metal tube 1 through the drawing die 9 to draw it.
It is locked inside the metal tube 1 at the position.

Further, the plurality of spheres 10 of the first rolling pressure applying portion which rotate in a planetary shape are pressed by the processing rings 14 and 15 and come into contact with the outer peripheral surface of the metal tube 1, and the inscribed circle diameter thereof is predetermined. The rolling pressure is applied to the metal tube 1 so as to have the dimension. The rolling pressure can be adjusted by changing the thickness of the shim 16.

The grooved plug 4 having a plurality of fine grooves 5 formed on its outer periphery is rotatably attached to the floating plug 2 via a connecting rod 3.

Further, the protruding plug 6 having a plurality of protruding portions 7 on the outer periphery is attached to the rear of the grooved plug 4 via the connecting rod 3.

A double nut 8, a thrust bearing having a small friction, a metal bearing, etc. are installed between the grooved plug 4 and the protruding plug 6 so that the grooved plug 4 and the protruding plug 6 rotate independently. Can be attached so that it can be.

Further, the plurality of spheres 24 rotating in a planetary pattern of the second rolling pressure applying portion located on the outer periphery of the primary grooved metal tube 12 between the grooved plug 4 and the protruding plug 6 are the processing rings. 1
It is pressed by 7 and 18 and contacts the outer peripheral surface of the primary grooved metal pipe 12 so that the inscribed circle diameter becomes a predetermined size.
A rolling pressure is applied to the next grooved metal tube 12. The rolling pressure can be adjusted by changing the thickness of the shim 19.

A plug unit 26 is composed of the floating plug 2, the connecting rod 3, the grooved plug 4, the double nut 8 and the protrusion plug 6. In the plug unit 26, the grooved plug 4 can be held at a predetermined position (a position where a plurality of balls 10 are installed) by the floating plug 2 engaging with the drawing die 9, and the same. In addition, the projection plug 6 can be held behind the grooved plug 4 at a predetermined position (the position behind the plurality of balls 24).

Therefore, the plug unit 26 is provided in the metal tube 1.
1 is moved from left to right in FIG. 1 (in the direction of arrow A), the metal tube 1 is contracted by a plurality of spheres 10 that rotate in a planetary manner at the position of the grooved plug 4. It is pressed against the grooved plug 4, and the primary groove 20 and the fins 22 are continuously formed on the inner surface of the metal tube 1 to form the primary grooved metal tube 12.

Next, the primary grooved metal tube is reduced in diameter to a predetermined inner diameter by a plurality of spheres 24 which are rotated in a planetary pattern between the grooved plug 4 and the protruding plug 6 and have a primary grooved shape. It becomes the reduced tube 25.

The protruding plug 6 located behind the plurality of balls 24 has a plurality of protruding portions 7. The diameter of the protruding plug 6 up to the apex of the protruding portion 7 is within the primary grooved contracted pipe 25. Fin 2
It is larger than the inner diameter of 2 (convex portion) and smaller than the diameter of the primary groove 20 (concave portion) in the contracted tube with primary groove 25. However, by moving the primary grooved contracted tube 25 in the direction of the arrow A in FIG. 1, the protrusions 7 of the protruding plug 6 are intermittently dotted at the fins 22 of the primary grooved contracted tube 25. By shaving or crushing, a secondary groove 21 corresponding to the shape of the protruding portion 7 of the protruding plug 6 is formed on the inner surface of the primary grooved contraction tube 25,
Inner surface double grooved metal pipe 1 having grooves 20 and 21 on the inner surface
3 is formed.

Further, the inner surface double-grooved metal tube 13 is reduced to a predetermined outer diameter by the finishing die 11 to form the inner surface double-grooved metal tube 23.

With the above-described structure of the apparatus for manufacturing a metal tube with an inner groove, particularly, since the second rolling pressure applying portion is provided between the grooved plug 4 and the protruding plug 6, a small number of processed plugs are provided. Now it is possible to process many kinds of groove depth.

As described above, one embodiment of the present invention has been described. The diameter of the protrusion of the plug with a protrusion to the apex of the protrusion is larger than the inner diameter of the fin (convex portion) of the contracted tube with a primary groove and the primary groove is As long as the condition that the diameter is smaller than the diameter of the primary groove (recess) in the contracted tube is satisfied, the inner diameter of the metal tube with the primary groove can be freely contracted by the second rolling pressure application section. , Protrusion 7
Any number, shape, and height of protrusions may be used.

[0030]

As described above, according to the method and apparatus for manufacturing a metal tube with an inner surface groove of the present invention, the second rolling pressure applying section is provided in front of the plug with protrusions, and the second rolling pressure is applied. Since the rolling pressure of the section can be adjusted, the pulling force on the metal pipe is reduced and the pulling out force is reduced to prevent the metal pipe from breaking, and the diameter of the metal pipe at the position of the protruding plug can be freely set. The depth of the groove on the inner surface of the metal pipe can be adjusted without changing the protruding plug, preventing the increase of processing plugs such as protruding plugs and grooved plugs, and managing labor of processing plugs. It has become possible to reduce manufacturing costs.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of an apparatus for manufacturing a metal tube with an inner groove according to the present invention.

FIG. 2 is a schematic view showing an embodiment of a conventional apparatus for manufacturing a metal tube with an inner groove.

FIG. 3 is a schematic view showing an embodiment of a conventional apparatus for manufacturing a metal tube with an inner groove.

[Explanation of symbols]

 1 Metal Tube 2 Floating Plug 3 Connecting Rod 4 Groove Plug 5 Groove 6 Groove 6 Plug 7 Protrusion 8 Double Nut 9 Drawing Die 10 Ball 11 Finishing Die 12 Primary Grooved Metal Pipe 13 Inner Double Grooved Metal Pipe 14 Machining Ring 15 Machining ring 16 Shim 17 Machining ring 18 Machining ring 19 Shim 20 Primary groove 21 Secondary groove 22 Fin 23 Inner surface double grooved metal tube 24 Ball 25 Primary grooved contracted tube 26 Plug unit 27 Grooveed plug 28 Groove 29 Secondary Groove 30 Rolling Tool 31 Rolling Tool 32 Metal Tube with Inner Double Groove

Claims (4)

[Claims] 1. A method of manufacturing a metal tube with an inner groove having a groove on an inner wall surface, wherein the metal tube is moved in a pipe axis direction, and a first processing plug that contacts the inner wall surface is provided inside the metal tube. The primary groove is formed by inserting the primary groove on the inner wall surface, and by applying a rolling pressure to the primary grooved metal pipe having the primary groove formed at the subsequent stage of the formation position of the primary groove. The secondary grooved metal pipe is contracted, and a second processing plug that comes into contact with the inner wall surface of the contracted primary grooved metal pipe is inserted into the contracted primary grooved metal pipe. A method of manufacturing a metal tube with an inner surface groove, which comprises forming a secondary groove. 2. The inner grooved metal according to claim 1, wherein the application of the rolling pressure changes a diameter of the primary grooved metal tube to be contracted by adjusting the rolling pressure. Pipe manufacturing method. 3. A manufacturing apparatus of a metal tube with an inner groove having a groove on an inner wall surface thereof, wherein a moving means for moving the metal tube in a tube axis direction and a first rolling means for applying a rolling pressure to an outer circumference of the metal tube. Rolling pressure applying means, and a metal tube with a primary groove provided inside the position of the metal tube to which the rolling pressure is applied and in contact with the inner wall surface and having a primary groove on the inner wall surface. And a first groove forming means for forming a groove, and at a subsequent stage of the first groove forming means, a rolling pressure is applied to the outer periphery of the primary grooved metal tube to contract the primary grooved metal tube. Second rolling pressure applying means and a secondary groove provided inside the contracted metal tube with a primary groove and having a secondary groove in contact with the inner wall surface of the compressed metal tube with a primary groove. And a second grooving means for forming the multi-grooved metal pipe described above. 4. The apparatus for manufacturing a metal tube with an inner surface groove according to claim 3, wherein the second rolling pressure applying means has a function of adjusting the rolling pressure.