JPS6012131B2 - Metal tube inner and outer surface processing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for processing the inner and outer surfaces of a metal tube, which gives a desired shape to the inner and outer surfaces of the metal tube.

For example, some metal tubes (steel tubes, aluminum tubes, etc.) used in heat exchangers have fins, grooves, protrusions, etc. formed on the inner and outer surfaces to improve heat transfer. Conventionally, when processing metal tubes into such shapes, methods have been used to give the inner and outer surfaces of the metal tubes a predetermined shape by extrusion, drawing, rolling, or the like.

With extrusion and drawing methods, it is difficult to obtain sharply shaped grooves or protrusions that improve heat transfer, and drawing requires a relatively large amount of drawing. This has the disadvantage that the metal tube is easily damaged and cannot be processed at high speed. On the other hand, the forming method has the disadvantage that the metal tube must be rotated, and therefore long products cannot be processed. Furthermore, even with a type of drawing machine that rotates rolling rolls, the drawing force becomes excessive as in the previous example, making it impossible to increase the processing speed. The disadvantage is that the large torsional force exerted on the metal tube deteriorates the surface condition of the metal tube and, in extreme cases, creates scale-like patterns due to foot breakage. This invention was made in view of the above circumstances, and it is possible to provide sharply shaped grooves or protrusions on the inner and outer surfaces of metal tubes without pushing out or pulling them out, and even on long products. The object of the present invention is to provide an apparatus for processing the inner and outer surfaces of metal tubes. An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

This device includes a ball die drawing device 2 that rolls a metal tube 1 to a predetermined pipe diameter and thickness, and a ball die drawing device 2 that is placed after this and further applies the inner and outer surfaces of the metal tube 1 processed by the ball die drawing device 2. It consists of a metal tube inner and outer surface processing machine 3 that gives a predetermined shape. First, the spherical die drawing device 2 will be explained.

Reference numeral 21 denotes a frame body, and a ball support body 23 is rotatably supported inside the frame body via bearings 22, 22.

A belt pulley 24 is fixedly attached to one side of the ball support 23, whereby rotational force from a drive source (not shown) is transmitted to the ball support 23 via a belt 25. Furthermore, the metal tube 1 is disposed through the center of the ball support 23 . Further, inside the ball support body 23, a plurality of balls 26 are arranged so as to be rotatable and in pressure contact with the outer surface of the metal tube 1. And ball 2
6 not only shrinks the metal tube 1 but also allows the metal tube 1 to move forward from the left to the right in the figure. Also, metal pipe 1
There is an inclined surface 27a at a position corresponding to the ball 26 inside the
A plug 27 having a diameter is placed in a floating manner. The outer diameter of this plug 29 is made slightly larger than the diameter of the inscribed circle that touches the innermost point of each ball 26, so that it cannot pass between the balls 26. ing. Next, the metal tube inner and outer surface processing machine 3 will be explained.

31 is a frame body, and a rolling roll support body 33 is rotatably supported inside the frame body via bearings 32, 32.

A belt pulley 34 is fixedly attached to the negative side of the roll support 33, and thereby the rotational force from another drive source (not shown) is transmitted to the roll support 33 via the belt 35. be done. Furthermore, the metal tube 1 is disposed to penetrate through the center of the rolling roll support 33 . Further, on the inside of the rolling roll support 33 and on the outside of the metal tube 1, there are a plurality of holes arranged at an angle of inclination 8 to the axis of the metal tube 1 and pressed against the metal tube 1. For example, three rolling rolls 3
6 are rotatably supported via bearings 37, 37, respectively. These rolling rolls 36 are each formed with an inclined portion 36a, a processed portion 36b, and an inclined portion 36c from the left to the right in the figure. The rolling roll 36 smoothly contacts the metal tube 1 through its inclined portion 36a and gives a predetermined shape (for example, a smooth surface) to a part of the outer surface of the metal tube 1. In addition, the rolling roll 36
The processed portion 36b imparts a predetermined shape (for example, a smooth surface) to the entire outer circumference of the metal tube 1, and can also be polished if necessary. On the other hand, a mandrel 38 is floatingly arranged inside the metal tube 1 at a position corresponding to the rolling roll 36.

Moreover, this mandrel 38 is connected to the rod 3 in the plug 27.
They are rotatably connected via 9. mandrel 38
A predetermined shape is formed on the outer surface of the rolling roll 3.
When rolling the metal tube 1 with the processed portion 36b of No. 6, a predetermined shape (for example, a spiral groove) is given to the inner surface of the metal tube 1. A gear 40 is provided at one end of the rolling roll 36, respectively.
are integrally attached. These gears 40 are meshed with internal gears 41, respectively. This internal gear 4
1 is rotatably supported by the frame 31 via a bearing 42. Further, a belt wheel 43 is fixedly attached to one side of the internal gear 41, so that rotational force from another drive source (not shown) is applied to the internal gear 41 via a belt 44. further transmitted to the rolling roll 36
transmitted to. Next, a case will be described in which processing is performed using the apparatus for processing the inner and outer surfaces of metal tubes having the above configuration.

First, two locations spaced apart by approximately 180° in the circumferential direction of the outer circumferential portion extending a predetermined distance rearward from the tip of the metal tube 1 are indented inward. The location where this recess is formed is located slightly toward the rear of the distance from one end of the plug 27 to the pond end of the mandrel 38. Further, the distance between the two recesses is made slightly smaller than the outer diameter of the plug 27. Next, plug 27
, the mandrel 38 and the rod 39 connecting them are inserted into the metal tube 1 from its tip in a predetermined direction. Thereafter, the tip of the metal tube 1 located at the front end of the mandrel 38 is kissed by a well-known swager. As a result, the plug 27 and the mandrel 38 are located within the metal tube 1 between the recess and the opening. In this way, the preparation for processing the metal tube 1 is completed. Next, in order to process the metal tube 1, first pass the opening part between the balls 26, 26 and the rolling rolls 36, 36, 36.
Insert it in between.

After that, the ball support 23 and the rolling roll support 33
Rotate. As the rolling roll support 33 rotates, the rolling roll 36 is in pressure contact with the metal pipe 1.
It revolves around and rotates on its own axis. At this time, since the rolling rolls 36 are inclined with respect to the metal tube 1, the metallic tube 1 moves forward due to the frictional force acting between the rolling rolls 36 and the metal tube 1. As the metal tube 1 moves forward, the plug 27 and the mandrel 38 are moved forward by the recess formed in the metal tube 1, and stop at a predetermined position. That is, the inclined portion 27a of the plug 27 is connected to the ball 26.
, 26, the plug 27 receives a force directed toward the rear of the metal tube 1 (toward the left in FIG. 2) by the balls 26, 26. At this time, the mandrel 38 has reached between the rolling rolls 36, 36, and 36, and due to the frictional force acting between it and the advancing metal tube 1, it moves toward the front of the metal tube 1 (toward the right in FIG. 2). The plug 27 and the mandrel 38 stop when these two forces are balanced.When the plug 27 and the mandrel 38 reach a predetermined position and stop, the ball 26 causes the inclined part 27a of the plug 27 to stop. The metal tube 1 is rolled (diameter reduced) along the line.The metal tube 1 rolled by the balls 26 is then processed on the inner surface by the mandrel 38 and on the outer surface by the rolling rolls 36, respectively.
As the machining progresses, the rear end of the metal tube 1 becomes the ball 26, 2.
6, the plug 2 by the balls 26, 26
Since no pressing force is applied to 7, the plug 27 moves forward as the metal tube 1 moves forward. However, the distance the plug 27 moves forward is only a short distance before it hits the balls 26, 26, and the mandrel 38
does not pass between the rolling rolls 36, 36, 36. Therefore, it goes without saying that the inner and outer surfaces of the metal tube 1 are processed until the rear end of the metal tube 1 passes between the rolling roll 36 and the mandrel 38. When the rear end of the metal tube 1 passes between the three rolling rolls 36, the plug 27 and the mandrel 38 come out of the metal tube 1. However, the processing may be stopped in the state shown in FIG. 2, in which case the metal tube 1 is cut and the plug 27 and mandrel 38 are taken out. Furthermore, the mandrel 38 receives a rotational force centering on the koji wire due to the frictional force with the metal tube 1, but it is made rotatable relative to the rod 39, and ``because it is rotated according to the rotational force, the metal The groove provided on the inner surface of the tube 1 is not deformed.The metal tube 1 is connected to the ball die drawing device 2.
When machining with metal pipe inner and outer surface processing machine 3
The balls 26 and rolling rolls 36 against the metal tube 1 are also subjected to torsional force when being processed by the
By reversing the rotation of the metal tube 1, the torsional force acting on the metal tube 1 can be offset, making it possible to faithfully give a predetermined shape to the inner and outer surfaces of the metal tube 1 and increase the manufacturing speed. .

Furthermore, if the belt pulleys 34 and 43 are respectively rotated in reverse, the rolling roll 36 will have an extremely high relative speed with respect to the metal tube 1, and as a result, high-speed processing becomes possible. Next, the present invention will be further clarified by introducing data obtained when spiral grooves were actually formed on the inner surface of a metal tube using the processing apparatus having the above configuration.

Outer diameter x inner thickness of metal tube before processing...120 x 0.
5. Number and outer diameter of side balls: 8, 7◇Inscribed circle diameter in contact with 8 balls: 100 Outer diameter of plug: 11, outer diameter of rod × Length...8 short ×
Outer diameter of 15-sided rolling roll...3503 rolling.

Diameter of the inscribed circle in contact with the mandrel...9.55◇Outer diameter of the mandrel...9.2◇Number, depth and angle of grooves formed in the mandrel, . ,,． ,300,15 ribs,
150 Number of revolutions of the balls...100 pm Number of revolutions of the rolling rolls...1000 pm Number of rotations of the rolling rolls...266 ratio pm As described above, the metal When I processed the pipe, the wall thickness was 0 at the 10th outer seat.
．． A metal tube with four ribs was obtained.

The acceleration rate was 10'min. Furthermore, grooves in good condition were formed on the inner surface of the metal tube after manufacture. In the above embodiment, the ball 26 is used as a roller to be rolled on the outer surface of the metal tube 1 when processing the diameter and thickness of the metal tube 1 to predetermined values, but the ball 26 is not limited to this, for example. A needle-shaped member may also be used.

In addition, when using a needle-shaped member, it is desirable to arrange|position it obliquely with respect to the metal tube 1 similarly to the rolling roll 36, for example. Further, although the above embodiment is provided with a mechanism for forcibly rotating the rolling roll 36, this mechanism is not necessarily required. As explained above, the apparatus for processing the inner and outer surfaces of metal tubes according to the present invention includes a rotating die drawing device for metal tubes, and a device disposed downstream of the rotating die drawing device to further impart a predetermined shape to the inner and outer surfaces of the metal tube. a metal tube inner and outer surface processing machine, the rolling rolls in the metal tube inner and outer surface processing machine are arranged to be inclined with respect to the bag line of the metal tube; Since the mandrel and the rod are connected together, the metal tube can be advanced by part of the rotational force of the rolling rolls. It has the advantage that it is possible to provide grooves or protrusions with a round shape, and it is also possible to process even the largest products.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view showing an embodiment of an apparatus for processing the inner and outer surfaces of metal tubes according to the present invention, and FIG. 2 is a cross-sectional view of essential parts along line D--D in the Japanese military map. 2...Metal tube, 2...Ball die drawing device, 3...Metal tube inner and outer surface processing machine "2 pieces, 31...Frame body, 23...Ball support ~ 24, 34, 43...Belt wheel , 26...
...To the ball 27...Plug, 33...Roll roll support t 36...Roll roll, 38...Mandrel "39
...Rod, 40...Gear 41...Internal gear. Fig. 1 Fig. 2

Claims (1)

[Claims] 1. A rotating die drawing device for rolling a metal tube, and a metal tube inner and outer surface processing machine arranged after the rotating die drawing device and further imparting a predetermined shape to the inner and outer surfaces of the metal tube processed by the rotating die drawing device. The rotating die drawing device includes a plurality of rotating bodies that are pressed against the outer surface of the metal tube, a drive mechanism that causes each of the plurality of rotating bodies to revolve around the metal tube, and a drive mechanism that causes the plurality of rotating bodies to revolve around the metal tube. The metal tube inner and outer surface processing machine is comprised of a plug floating at a position corresponding to the plurality of rotating bodies inside, and the metal tube inner and outer surface processing machine rotates outwardly of the metal tube at an inclined angle with respect to the axis of the metal tube. a plurality of rolling rolls that are freely arranged and press-welded to the metal tube; a drive mechanism that causes each of the rolling rolls to revolve around the metal tube; and a drive mechanism that corresponds to the plurality of rolling rolls inside the metal tube. It consists of a mandrel that is suspended in a position that
The apparatus for processing the inner and outer surfaces of a metal tube, wherein the plug and the mandrel are connected by a rod.