JP3279477B2 - Internal grooved tube manufacturing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for manufacturing an inner grooved pipe, and more particularly, to an inner grooved pipe for forming a double groove on an inner surface of a metal pipe without increasing a drawing force while applying a rolling pressure. Related to a manufacturing apparatus.

[0002]

2. Description of the Related Art Conventionally, copper or copper alloy bare tubes have been used as heat transfer tubes for heat exchangers. Further, recently, as such a heat exchanger tube for a heat exchanger, an inner grooved tube having high heat transfer performance even with a phase-changing fluid such as chlorofluorocarbon has been frequently used.

[0003] Such a heat exchanger tube for a heat exchanger is an inner grooved tube having a fine spiral groove on the inner surface for improving the heat transfer performance. Recently, an inner groove is provided for improving the heat transfer performance. It is a heavy inner grooved tube.

[0004] Fig. 4 shows an apparatus for manufacturing an inner double grooved pipe, which is one form of a conventional apparatus for manufacturing an inner grooved pipe. The manufacturing apparatus reduces the rolling pressure by rotating a plurality of balls 8 and 9 in a direction perpendicular to the tube axis around the outer peripheral surface of the metal tube 1 in a planetary manner and pushing the metal tube 1 radially on the outer peripheral surface. Two rolling pressure applying means 16 and 17 on the same axis for applying and contracting a tube, locking means 10 for locking the floating plug 2 inside the metal tube 1, and a connecting rod 3 for connecting the floating plug 2 to the floating plug 2. The connected primary grooved plug 4 is rotatably inserted into the metal tube 1 and contracted by the rolling pressure applying means 16 to process the primary groove 11 inside the metal tube 1. The first groove processing means and the secondary grooved plug 6 connected by the connecting rod 3 behind the primary grooved plug 4 are rotatably inserted into the primary grooved metal tube 12. The primary grooved metal tube 12 is contracted by the rolling pressure applying means 17. It is an apparatus for manufacturing the inner surface double grooved tube by a second groove processing means for processing the 2 Tsugimizo 13 therein.

That is, the rolling tools 16 and 17 which are the rolling pressure applying means of the manufacturing apparatus are arranged in two stages, and the groove machining connected to the floating plug 2 is provided at a corresponding position of each of the rolling tools 16 and 17. The grooved plugs 4 and 6 as means are arranged,
The double-grooving process was continuously performed inside the metal tube 1.
Accordingly, by moving the metal tube 1 from left to right (in the direction of arrow A), the metal tube 1 is moved by the primary rolling tool 16 (sphere 8) that rotates in a planetary manner at the position of the primary grooved plug 4. The rolling pressure is applied and the tube is compressed and pressed against the plug 4 with the primary groove, so that the primary groove 11 is continuously formed on the inner surface. Then, the secondary rolling tool 17 and the secondary groove are formed in the same process. The secondary groove 13 is formed by the attached plug 6, and accordingly, the double grooves 11, 13 are formed continuously on the inner surface of the metal tube 1.

[0006] Thus, an inner double grooved tube having high heat transfer performance is manufactured by the manufacturing apparatus.

[0007]

However, according to the conventional apparatus for manufacturing an inner grooved pipe, a rolling tool for rotating the outer peripheral surface of the metal pipe 1 and a floating plug 2 in the metal pipe 1 are provided.
The rolling pressure generated by a rolling tool set (for example, a pair of a rolling tool 16 and a grooved plug 4) composed of grooved plugs connected by a connecting rod 3 generates a large tensile force on the metal tube, Therefore, a large pulling force is required, and the metal tube is easily broken. Furthermore, in order to manufacture a grooved tube with an inner surface having a higher heat transfer performance, when the groove on the inner surface of the metal tube is doubled or more, two or more rolling tool sets are required, and the tensile force on the metal tube is further increased. And the pull-out force increases, and the risk of breakage of the metal tube increases. Furthermore, as shown in FIG. 4, when the rolling tool set has two stages, the structure of the apparatus is complicated, and it is difficult and time-consuming to adjust the two rolling tool sets. Furthermore, in order to manufacture inner grooved tubes with higher heat transfer performance,
If the groove on the inner surface of the metal tube is tripled or more, it is necessary to improve the equipment, and it is extremely difficult to perform initial adjustment and speed change of three or more rolling tool sets. The risk of breakage increases. Further, in order to prevent the metal pipe from being broken, the shapes of the grooves 5, 7 of the grooved plugs 4, 6 must be limited (for example, the grooves 5, 7 are made shallow, the number of the grooves 5, 7 is reduced, etc.). Therefore, the grooves 5 and 7 lack the flexibility of the shape, and it is difficult to manufacture an inner grooved tube having higher heat transfer performance. Further, as the number of rolling tool sets increases, the frictional heat between the metal tube and the rolling tool due to the rolling pressure increases, and it becomes difficult to cool the frictional heat.

Accordingly, it is an object of the present invention to reduce the rolling pressure, to easily adjust a plurality of rolling pressure applying means, and to easily cool frictional heat between the metal pipe and the rolling pressure applying means. It is an object of the present invention to provide an apparatus for manufacturing an inner grooved pipe that can be used.

[0009]

According to the present invention, two sets of rolling pressure applying means comprising a plurality of spheres and a plurality of roll-shaped rotating bodies supporting the spheres are provided. Device structures arranged at the positions of the groove processing means.

[0010] In this case, the rolling pressure applying means is connected to each set of roll-shaped rotating bodies supporting the sphere via a thrust bearing, which is a small friction member, and is supported by one rotating body. The groove processing means corresponding to the plurality of rolling pressure applying means can be independently rotated.

[0011] The roll-shaped rotator in each set of the rolling pressure applying means is configured such that the outer diameter of the rear set in the moving direction of the metal tube is larger than the outer diameter of the front set. It is desirable.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an apparatus for manufacturing an internally grooved pipe according to the present invention will be described in detail.

FIG. 1 shows an embodiment of the present invention. This apparatus comprises a first rolling pressure applying means, a second rolling pressure applying means,
A groove processing device including a groove processing means, a second groove processing means, a spacer 26, a reinforcing ring (rotary body) 24, and a rotary head 27, a floating plug 2, a connecting rod 3, a drawing die 10, and a finishing die Consists of eighteen.

The floating plug 2 is locked inside the metal tube 1 at the position of the drawing die 10 by passing the metal tube 1 through the drawing die 10.

Further, the plurality of balls 8 which freely rotate in the outer peripheral direction and the drawing direction of the metal tube 1 supported by the plurality of backup rolls 21 which are the first rolling pressure applying means of the groove forming device are provided by the backup roll. 21 and is brought into contact with the outer peripheral surface of the metal tube 1 so that the inscribed circle diameter thereof has a predetermined size.

The outer diameter of the second rolling pressure applying means of the groove forming apparatus is equal to that of the backup roll 2 of the first rolling pressure applying means.
The plurality of spheres 9 that freely rotate in the outer peripheral direction and the drawing direction of the metal tube 12 supported by the backup roll 22 larger than the outer diameter of
And comes into contact with the outer peripheral surface of the metal tube 12, so that the inscribed circle diameter thereof has a predetermined size.

Further, each of the backup rolls 2
1 and 22 are connected to the reinforcing ring 24 by a shaft 25.
And the rotating head 27. Here, thrust bearings 19 are provided between the backup rolls 21 and 22 and between the backup rolls 21 and 22 and the reinforcing ring 24 to reduce frictional force.

The spheres 8 and 9 are of the same size, and the installation position is determined by the pacer 26 so that they do not touch each other.

Here, the grooved plug 4 having a plurality of fine grooves 5 formed on the outer periphery, which is the first groove processing means, is rotatably attached to the floating plug 2 via the connecting rod 3.

Further, a grooved plug 6 having a smaller outer diameter than the grooved plug 4 having a plurality of fine grooves 7 formed on the outer periphery, which is a second groove processing means, is connected via the connecting rod 3 to the grooved plug 6. It is mounted behind the plug 4.

A thrust bearing 19 and a metal bearing having a small friction are installed between the grooved plug 4 and the grooved plug 6 so that the grooved plug 4 and the grooved plug 6 rotate independently. It is attached so that it can be.

A plug unit 28 is constituted by the floating plug 2, the connecting rod 3, the grooved plug 4, the grooved plug 6, and the thrust bearing 19. The plug unit 28 can hold the grooved plug 4 at a predetermined position (the inside of the metal tube 1 where the plurality of balls 8 are installed) by engaging the floating plug 2 with the drawing die 10. Similarly, the grooved plug 6 can be held at a predetermined position behind the grooved plug 4 (inside the metal tube 12 where the plurality of balls 9 are installed). Has become.

Here, FIG. 2 schematically shows an example of the arrangement of the plurality of balls 8 and the backup roll 21 installed on the outer peripheral surface of the metal tube 1. The same arrangement is also applied to the second rolling pressure applying means. Become. As shown in FIG. 2, one ball 8 is supported by two backup rolls 21 adjacent to each other. Here, the number of the spheres 8 and the number of the backup rolls 21 are four respectively, but the number is not limited to four, but may be three or more.

In FIG. 1, the plurality of spheres 8 and spheres 9
Is rotated simultaneously via the plurality of backup rolls 21 and 22 by the rotation of the rotating body including the rotating head 27 and the reinforcing ring 24.

Therefore, the plug unit 28 is provided in the metal tube 1.
By moving the metal tube 1 from left to right in FIG. 1 (in the direction of arrow A) in a state in which the metal tube 1 is inserted, the metal tube 1 is contracted by a plurality of balls 8 which freely rotate at the position of the grooved plug 4. Then, it is pressed against the grooved plug 4, the primary groove 11 and the fin 15 are continuously formed on the inner surface of the metal tube 1, and the primary grooved tube 12 is formed.

The outer diameter of the grooved plug 6 is the same as
It is smaller than the inner diameter of the fin 15 (projection) in the next grooved tube 12. However, by moving the primary grooved tube 12 in the direction of arrow A in FIG.
A rolling pressure 2 is applied to the grooved plug 6 at a position of the grooved plug 6 by a plurality of balls 9 freely rotating simultaneously with the ball 8.
The groove 7 of the grooved plug 6 intermittently cuts the fin 15 of the primary grooved tube 12, and the grooved plug 6 is formed on the inner surface of the primary grooved tube 12. A secondary groove 13 corresponding to the shape of the groove 7 is formed, and the groove 1 is formed on the inner surface.
A secondary grooved tube 14 having a groove 1 and a groove 13 is formed.

Further, the secondary grooved tube 14 is provided with a finishing die 1
8, the inner diameter of the tube 23 is reduced to a predetermined outer diameter.

With the construction of the apparatus for manufacturing an inner grooved pipe as described above, the rolling pressure is reduced particularly by supporting the plurality of balls 8, 9 of the rolling pressure applying means with the backup rolls 21, 22. For this reason, the pulling force on the metal tube can be reduced, the pulling force can be reduced, and the breakage of the metal tube can be prevented.

Further, by arranging a plurality of rolling pressure applying means in the same rotating body, adjustment of the plurality of rolling pressure applying means can be simplified in a short time. Cooling against frictional heat between the metal tube and the rolling pressure applying means can be easily performed.

[0030]

As described above, according to the apparatus for manufacturing an internally grooved pipe of the present invention, the rolling pressure can be reduced, and the adjustment of the plurality of rolling pressure applying means can be simplified in a short time. There is an advantage that cooling of frictional heat between the metal tube and the rolling pressure applying means can be easily performed.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an embodiment of a manufacturing apparatus according to the present invention.

FIG. 2 is an explanatory view showing a cross section of a rolled portion in one embodiment of the manufacturing apparatus according to the present invention.

FIG. 3 is a schematic view showing one embodiment of a conventional apparatus for manufacturing an inner grooved pipe.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal tube 2 Floating plug 3 Connecting rod 4 Slotted plug 5 Groove 6 Slotted plug 7 Groove 8 Ball 9 Ball 10 Drawing die 11 Primary groove 12 Primary grooved tube 13 Secondary groove 14 Secondary grooved tube 15 Fin 16 Rolling Tool 17 Rolling Tool 18 Finishing Die 19 Thrust Bearing 20 Backup Roll 21 Backup Roll 22 Backup Roll 23 Inner Groove Tube 24 Reinforcement Ring 25 Shaft 26 Spacer 27 Rotary Head 28 Plug Unit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FIF28F 1/40 F28F 1/40 D (72) Inventor Tadao Otani 3550 Kida Yomachi, Tsuchiura-shi, Ibaraki Pref. Hitachi Cable, Ltd. System Materials (56) References JP-A-7-60334 (JP, A) JP-A-57-6016 (JP, A) JP-A-60-15015 (JP, A) (58) Fields studied (Int. Cl. ⁷ , DB name) B21C 1/00-19/00 B21C 37/20 B21D 53/06 B21H 3/00 F28F 1/40

Claims (2)

(57) [Claims] 1. An apparatus for manufacturing an inner grooved tube having a groove on an inner wall surface, comprising: a moving means for moving a metal tube in a tube axis direction; a plurality of spheres; and a plurality of roll-shaped rotating members for supporting the plurality of spheres. And at least two sets of rolling pressure applying means, wherein the plurality of spheres are in contact with the outer periphery of the metal tube and apply a rolling pressure, and inside the metal tube at the position of the rolling pressure applying means. And at least two groove processing means for forming a groove in the inner wall surface in contact with the inner wall surface of the metal tube, wherein the rolling pressure applying means includes a thrust bearing in which each set of roll-shaped rotating bodies is interposed. An inner grooved pipe manufacturing apparatus characterized in that the pipes are connected by a rotating body and are supported by a single rotating body. 2. The sphere of said rolling pressure applying means has the same size, and the outer diameter of the rear set of roll-shaped rotating bodies of each set of said rolling pressure applying means is the outer diameter of the front set. The apparatus for manufacturing an internally grooved pipe according to claim 1, wherein the pipe is larger than the pipe.