JPS6033814A - Processing device of metallic tube with grooved inner surface - Google Patents

Abstract

PURPOSE:To improve the processing speed of a metallic tube with grooved inner surface and to make the double-grooves forming process easy by arranging the 1st and 2nd inner surface-groove processing parts on a straight line and installing continuous tube-drawing devices between both processing parts and at the rear side of the 2nd processing part. CONSTITUTION:A metallic tube 1 to be processed is sent to the 1st inner surface-groove processing part through a die 2; the tube 1 is subjected to the 1st reduction of diam. and the formation of the 1st groove 16 with the aids of a grooved plug, a processing head 5, and plural steel balls 6 for formation, and then is drawn by a caterpillar drawing device 19 through a sizing die 18. Successively, the metallic tube 1 is introduced to the 2nd inner surface-groove processing part through a tube guide 21, and is subjected to the 2nd reduction of diam. and the formation of double grooves 13 with the aids of a grooved plug 12, a processing head 22, and plural steel balls 11 for reduction, and then is drawn by the 2nd caterpillar drawing device 24 through a finish die 26, and is wound up by a winder. In this way, the resistance burdened on the tube 1 to be processed on the way of process can be dispersed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for processing internally grooved metal tubes, particularly internally double grooved metal tubes.

Conventionally, a method as shown in FIG. 1 has been proposed as a method for processing a metal tube with internal grooves, and a method as shown in FIG. is proposed.

That is, in the conventional method for processing a metal tube with internal grooves, as shown in FIG. A grooved plug 4, a part where the inner groove is formed by a plurality of tube shrinking steel balls 6 rotating planetarily in a head 5 rotating in the direction of the arrow 10, and a part of the finishing die 7. While being subjected to frictional resistance and plastic deformation resistance, the tubes are pulled in the direction of arrow 8 by means such as a continuous drawing machine and moved in the axial direction, thereby continuously forming grooves on the inner surface of the tube.

Processing is possible if the sum of the above resistances is smaller than the product of the cross-sectional area of the tube 1 in the portion after the finishing die 7 and the tensile strength of the tube material in that portion, that is, the strength of the material. Among the resistances applied to the tube 1, the plastic deformation resistance has speed dependence, and when the tensile speed exceeds a certain value, the sum of the resistances exceeds the material strength, and as a result, the tube 1 breaks and becomes difficult to process. It becomes impossible to continue.

On the other hand, the conventional processing method for metal tubes with internal double grooves is as follows:
A method as illustrated in FIG. 2 is used. That is, in the same figure, in addition to the above-mentioned steel balls 6 for pipe shrinking, another set of steel balls 11 for pipe shrinking is housed in the processing head 5, and another set of steel balls 11 for pipe shrinking is housed at a position in the pipe relative to this steel ball 6. A grooved plug 12 is arranged. floating plug 3
, the first grooved plug 4, and the second grooved plug 12 are rotatably connected to each other by a rod 9.

In this state, when the metal tube 1 is continuously moved in the direction of arrow 8 to perform internal groove processing, the double grooves 13 are continuously formed, but the frictional resistance in the steel ball 11 and the grooved plug 12 Due to the addition of plastic deformation resistance, the sum of the resistances greatly increases the strength of the material, which often causes the tube 1 to break as described above. Therefore, in the case of the conventional method, double grooving can only be performed under a certain narrow range of processing conditions.

Therefore, an object of the present invention is to improve the machining speed of internally grooved metal tubes by eliminating the drawbacks of the prior art as described above and dispersing the resistance applied to the tube to be processed during machining. An object of the present invention is to provide a processing device that facilitates the processing of attached pipes.

That is, the present invention provides an internally grooved metal pipe processing apparatus in which a first internally grooved part and a second internally grooved part are arranged in a straight line, and a continuous pipe drawing device is provided after the double jaw part. This is a metal tube processing device with internal grooves.

The present invention will be described below with reference to one embodiment of the present invention shown in FIGS. 3 and 4.

FIG. 3 is a schematic view showing an embodiment of the present invention for machining an inner double groove, and FIG. 4 is a detailed view of the main part thereof. In FIGS. 3 and 4, a metal tube 1 to be processed is supplied from an uncoiler 14 to a processing device, passes through a die 2 held by a gouer foil 15, and is sent to a first inner groove processing section. The first inner groove processing section includes a grooved plug 4 located in the metal tube 1, a processing head 5 rotatably provided on the outer periphery of the metal tube 1 corresponding to the grooved plug 4, and a processing head 5 accommodated in the processing head 5. A plurality of tube shrinking steel balls 6 and a holder 17 that roll in contact with the outer circumferential surface of the metal tube 1 and the inner circumferential surface of the processing head, respectively.
A sizing die 18 is held in the tube, where the tube 1 to be processed undergoes a first shrinking process and a first groove 16 is formed in the inner surface of the tube by a grooved plug. After that, the pipe is pulled out by a caterpillar 19, which is a continuous pipe drawing device. Furthermore, metal tube 1
is supplied to the second internal groove processing section through the tube guide 21 within the holder 20. As in the first case, the second internal groove processing section includes a grooved plug 12 and a rotating processing head 22.
, a plurality of steel balls 1 for pipe shrinking that are housed in the processing head 22 and roll in contact with the outer circumferential surface of the metal tube 1 and the inner circumferential surface of the processing head.
1, and a finishing die 26 held in a holder 23. Here, the metal tube 1 is subjected to a second shrinking process, and a second groove is formed on the inner surface of the metal tube by a grooved plug 12 to form a double groove 13, and then passed through a finishing die 26. As a result, the outer diameter of the tube is drawn to a predetermined value, and the tube is wound up by a winder 25 while being pulled by a second caterpillar 24, which is a second continuous drawing device.

In the embodiments described above, a caterpillar was used as the continuous drawing device, but other drawing devices such as a continuous drawing machine may also be used.

According to the present invention, since the first processing head 5 and the second processing head 22 are provided separately, single groove processing can be performed without using the second processing head. In this case as well, since the first grooved part and the finishing die part are insulated by the first caterpillar 19, the resistance applied to the metal tube to be machined when pulled by the second caterpillar is due to the finishing die 26.
There is only resistance of . Therefore, compared to the known internal grooving method shown in FIG. 1, when the tube is drawn through the finishing die 26, there is less resistance to the tube and the sizing die 18 requires less gluing. Furthermore, since the finishing die 26 greatly increases the glue duct, it is possible to form grooves in areas where the tube has a large cross-sectional area, and the overall processing speed can be increased.

Furthermore, the apparatus of the present invention can also be used to perform processing without forming any internal grooves. In other words, by not using the processing heads 5 and 22 and using a normal floating plug and die, it can be used as a tandem drawing machine that can perform drawing twice in one process, so high reduction can be achieved. It can also be used as a highly efficient steel pipe drawing machine.

However, when using a flat pipe of a certain length to machine the inner surface with double grooves as a holding method for a grooved plug, it is necessary to use a long rod to hold the grooved plug instead of a floating plug. It may also be held on an external fixed part.

Since the present invention is configured as described above, it has the following effects.

(1) Double-grooved heat exchanger tubes can be made with high efficiency in one process.

(2) It is possible to process ordinary internally grooved pipes at higher speeds than before.

(3) It is possible to process deep grooved metal tubes that have greater processing resistance than ordinary internally grooved tubes.

(4) It can also be used as a tandem drawing machine that can perform drawing twice in one step without forming internal grooves.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing an example of a conventional internal groove processing device, FIG. 2 is a cross-sectional view showing an example of a conventional internal double-grooved pipe processing device, and FIG. 3 is a cross-sectional view showing an example of a conventional internal groove processing device. A schematic diagram showing an example of a pipe processing apparatus, and FIG. 4 is a cross-sectional view showing the main part of FIG. 3. 1. Pipe to be processed, 2. Die, 3. Floating plug, 4.12.. Grooved plug, 5.22. Processing head, 6.11.. Steel ball, 16.. Inner groove, 18.. Zizing die, 19.24 Caterpillar extraction device, 21.
・Tube guide, 26... Finishing die.

Claims (1)

[Claims] (1) In an internally grooved metal tube processing device in which a first internally grooved part and a second internally grooved part are arranged in a straight line,
An apparatus for processing an internally grooved metal tube, characterized in that a continuous tube drawing device is provided between both processing sections and after the second internal groove processing section.