JPS6036326B2 - 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 provides unevenness or spiral grooves on the inner and outer surfaces of the metal tube.

For example, metal pipes (steel pipes, aluminum pipes, etc.) used in heat exchangers have irregularities not only on the outer surface but also on the inner surface, and spiral grooves are formed to improve heat transfer. There are things.

Conventionally, when forming uneven or helical grooves on the inner surface of a metal tube, for example, a plug is inserted into the metal tube while being fed in the direction of the rutting line of the metal tube by drawing, and then the plug is inserted into the metal tube. This was done by press-fitting a die through a metal tube.

However, in such a processing method, when the metal tube flows, an extremely large frictional resistance is generated between the metal tube and the die, so that drawing must be performed with a considerably strong force. Therefore, for example, when applying larger machining or increasing the machining speed, the metal tube must be pulled out with greater force, but doing so may cause damage to the metal tube.
Therefore, within a certain limit, it was not possible to add a larger amount of processing or increase the processing speed. Furthermore, when creating spiral grooves on the inner surface of a metal tube, for example, the die must be rotated, but this causes the metal tube to twist due to the frictional force generated between the metal tube and the die. The drawback was that good processing was not possible.

This invention was made in view of the above circumstances, and by allowing the metal tube to flow without applying any external pulling force, it is possible to increase the degree of processing without damaging the metal tube, and to reduce processing damage. It is an object of the present invention to provide an apparatus for machining the inner and outer surfaces of a metal tube, which can increase productivity and prevent twisting of the metal tube.

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

In the figure, reference numeral 1 denotes a rolling roll support, which is rotatably supported by a frame (not shown) and rotated in the direction of arrow A in Figure 2 by a drive mechanism (not shown). . A metal tube 2, which is a workpiece, is inserted through the center of the rolling roll support 1. In addition, the rolling roll support 1
Inside the metal tube 2, on the outside of the metal tube 2, a plurality of rolling rolls 3, for example, three, which are inclined at a predetermined angle with respect to the axis of the metal tube 2 and pressed against the metal tube 2, are attached to the arm 4. They are each rotatably supported through them. On the other hand, a plug 5 is located inside the metal tube 2 at a position corresponding to the rolling roll 3.
is rotatably supported by a mandrel 6. The outer surface of the plug 5 has a predetermined shape, for example, a helical groove. Further, at a stage adjacent to and after the rolling roll support 1, a drive mechanism (not shown) moves the shafts in the directions of arrows B and C, respectively, around axes 7 and 8 perpendicular to the marking line of the metal tube 2. Rotated guide rolls 9 and 10 are compressed on the upper and lower surfaces of the metal tube 1, respectively, and are arranged to handle and hold the metal tube 1. Further, a hard urethane rubber layer is attached to the surfaces of the guide rolls 9 and 10 that contact the metal tube 2, and furthermore, a hard urethane rubber layer is attached to the surface of the hard urethane rubber layer.
Grooves 9a and 10a are provided along the marking lines, respectively. Next, a case will be described in which a metal tube is processed using an apparatus for processing the inner and outer surfaces of metal tubes having an upper track configuration.

First, the metal tube 2 with the plug 5 inserted therein is inserted into the center of the roll support 1, that is, into the center of the three rolls 3. As the roll support 1 is rotated by a drive mechanism (not shown), each roll 3 revolves around the metal tube 2 and is strongly pressed against the outer surface of the metal tube 2. Therefore, it rotates around its axis. Then, since each rolling roll 3 is inclined at a predetermined angle with respect to the axis of the metal tube 2, when the rolling roll 3 rotates in pressure contact with the metal tube 2, the axial direction of the frictional force generated between the two rolls is reduced. This component becomes a thrust force that moves the metal tube 2 forward, so that the metal tube 2 can be moved in the right direction toward the left in FIG. 1 without applying any external pulling force or the like. At the same time, the outer surface of the metal tube 2 is pressed against the rolling roll 3, so that the inner surface of the metal tube 2 is pressed against the plug 5.
As a result, a helical groove is formed on the inner surface of the metal tube 2. At this time, since the outer periphery of the metal tube 2 is sequentially rolled in the circumferential direction by the rolling rolls 3 revolving around it, the portion passing between the rolling rolls 3 may swing like a hundred swings. In this respect, in this processing apparatus, guide rolls 9 and 10 are arranged at the rear stage of the rolling roll 3, and these guide rolls 9 and 10' cause the metal tube to
Since the metal tube 2 is held in place, it is possible to prevent the metal tube 2 from swinging. Moreover, in this case, since the guide rolls 9 and 10 are arranged close to the rolling roll 3, it is possible to prevent the metal tube 2 from vibrating. That is, when the guide rolls 9, 10 are separated far from the rolling roll 3, the metal tube 2 existing between the guide rolls 9, 10 and the rolling roll 3 can move relatively freely due to its own elasticity. . For this reason, although the metal tube 2 is prevented from a large swinging motion, it vibrates with a small amplitude, and this vibration deteriorates the inner and outer surfaces of the metal tube 2. Therefore, in this invention, the guide roll 9
, 10 are arranged close to the rolling rolls. Note that if the guide rolls 9 and 10 are driven, the metal tube 2
receives the force in the forward direction from the guide rolls 9 and 10 and moves forward even more smoothly.

As mentioned above, the rotation of the rolling rolls 3 includes a component in the direction in which the metal tube 2 moves forward, and the frictional force that conventionally acted in the direction of preventing the metal tube 2 from moving forward is not only reduced but also On the contrary, it acts in a direction to actively move the metal tube 2 forward, and the rotation of the guide rolls 9 and 10 also acts in a direction to move the metal tube 2 forward. Therefore, no external force is required, so that even if the degree of machining is increased, the metal tube 2 will not be damaged, and the machining speed can be increased. Moreover, since the rolling rolls 3 are made to revolve around the metal tube 2, there is no need to rotate the metal tube 2, and therefore the longest metal tube can be processed. Further, when the rolling roll 3 rotates while being in pressure contact with the metal tube 2, the metal tube 2 receives a torsional force in the direction in which the rolling roll 3 rotates due to part of the frictional force generated between the two. Therefore, the frictional force is reduced compared to the conventional one, and the guide rolls 9, 1
The metal tube 2 can be prevented from being twisted by the zero gripping force. FIG. 4 shows another embodiment according to the invention.

In this embodiment, before the step of machining the inner and outer surfaces of the metal tube, a rotating body such as a ball 21 is brought into pressure contact with the outer surface of the metal tube 2 while revolving around the metal tube 2, and a drawing plug 22 is inserted into the metal tube. The plug 5 and the extraction plug 22 are rotatably connected to each other by a rod 23. In addition, when processing the metal tube 2 with the above-mentioned Yokozumi processing apparatus, it is carried out as follows. First, two points 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 2 are indented inward.

This recess is formed from one end of the plug 22 to the plug 5.
The location is slightly further back than the distance to the edge of the pond.
Further, the distance between the two recesses is made slightly smaller than the outer diameter of the plug 22. Next, the plugs 22 and 5 connected to each end of the rod 23 are inserted into the metal tube 2 from their tips in a predetermined direction. Thereafter, the tip of the metal tube 2 located ahead of the plug 5 is kissed using a well-known swager. As a result, the plugs 5 and 22 are located within the metal tube 2 between the recess and the opening. In this way, the preparation for processing the metal tube 2 is completed. Next, in order to process the metal tube 2, the opening part is first cut into the balls 21 and 2.
1 and insert it between three rolling rolls 3. Thereafter, the rolling rolls 3 are revolved, and the metal tube 2 is advanced. As the metal tube 2 moves forward, the plugs 5 and 22
It is moved forward by a recess formed in it, and stops when it reaches a predetermined position. That is, when the tip of the plug 22 reaches between the balls 21, 21, the plug 22 touches the ball 21.
, 21, a force directed toward the rear of the metal tube 2 (toward the left in FIG. 4) is applied. At this time, the plug 5 has reached between the three rolling rolls 3, and due to the frictional force acting between it and the advancing metal tube 2, a force is directed toward the front of the metal tube 2 (toward the right in FIG. 4). receive. When these two forces balance, the plugs 5 and 22 stop. Then, when the plugs 5 and 22 reach a predetermined position and stop,
Rolling (vertical diameter) of the metal tube 2 is performed by the balls 21 . The metal tube 2 rolled by the ball 21 is then
The inner surface is processed by the plug 5, and the outer surface is processed by the rolling roll 3. Then, as the processing progresses and the rear end of the metal tube 2 passes between the balls 21, 21, the ball 21
, 21 no longer acts on the plug 22, so that the plugs 5, 22 move forward as the metal tube 2 moves forward.

However, the advancing distance is only a short distance until the plug 22 comes into contact with the ball 21, and the plug 5 does not pass between the three rolling rolls 3 due to the advancing distance. Therefore, it goes without saying that the inner and outer surfaces of the metal tube 2 are processed until the rear end of the metal tube 2 passes between the rolling roll 3 and the plug 5. When the rear end of the metal tube 2 passes between the three rolling rolls 3, the plugs 5, 22 and the rod 23 come out of the metal tube 2. Note that the processing may be stopped in the state shown in FIG. 4, and in this case, the metal tube 2 is cut and the plugs 5, 22 and rod 23 are taken out. In this way, the length of the metal tube 2 can be processed even if it is long without being limited by the length of the mandrel 6, and since highly accurate rolling can be performed before processing the inner and outer surfaces,
The advancing state of the metal tube 2 also becomes extremely good. Furthermore, by reversing the rotational directions of the rolling rolls 3 and the balls 21, twisting of the metal tube 2 can be further prevented. 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 of metal tube before processing x wall thickness...12◇ x 0.
5. Number and outer diameter of side balls: 8, 708 Diameter of inscribed circle in contact with balls: 100 Outer diameter of plug 22: 10.10 Outside of rolling roll Diameter...
...350 Diameter of the inscribed circle touching the three rolling rolls...9.55?
Outer diameter of plug 5...90 Number, depth and angle of grooves formed in plug 5...65 0.2 ribs,
140 rod outer diameter
/min, and the wall thickness is 0.5 on the 9.5 side after processing.
We were able to manufacture a metal tube for the skin.

In each of the embodiments described above, the guide rolls 9 and 10 are driven to rotate, but they may be simply supported rotatably without being driven.

Further, in the above embodiment, the rolling roll 3 has a simple cylindrical shape, but the shape is not limited to this, and it may be, for example, a cylindrical shape.

In this way, the area in contact with the metal tube 2 is increased, and good rolling can be performed. In addition, the rolling roll 3
By forming a predetermined shape on the outer surface of the metal tube 2, the outer surface of the metal tube 2 can also be given a predetermined shape. moreover,
In each of the above embodiments, the roll roll 3 is supported rotatably, but if the roll roll 3 is forcibly rotated using a drive source, the rotation of the roll roll 3 relative to the metal tube 2 can be controlled. The speed can be increased and therefore the processing speed can be further increased.

As explained above, according to the apparatus for processing the inner and outer surfaces of a metal tube according to the present invention, a plurality of rolling rolls having an inclination angle with respect to the koji line of the metal tube rotate while revolving around the metal tube to produce a metal tube. Since the inner surface of the metal tube is given a predetermined shape and a plurality of guide rolls rotate to support the metal tube, the metal tube can be advanced by a portion of the rotational force of the rolling rolls, and therefore the external Forces such as drawing are no longer required, making it possible to increase processing efficiency and processing speed to increase productivity, and furthermore, it is possible to prevent twisting of the metal tube.

In addition, since the frictional force between the metal tube and the rolling roll can be reduced, the tensile force applied to the mandrel is reduced, and as a result, double-row inner and outer surface machining is possible, such as intersecting helical grooves. It is also possible to manufacture metal pipes with parallel grooves and helical grooves. Moreover, since the rolling rolls are revolving, there is no need to rotate the metal tube, and therefore long metal tubes can be processed.

Furthermore, since the metal tube is sandwiched between guide rolls placed next to the rolling rolls, it is possible to prevent the metal tube from swinging or vibrating. Processing can be performed even more smoothly. Well, if at least one of the plurality of guide rolls is forcibly rotated, the advance of the metal tube will be smoother, thereby increasing the degree of machining and increasing the machining speed, resulting in more production. It has the effect of increasing sex.

[Brief explanation of the drawing]

FIG. 1 is a schematic longitudinal sectional front view showing an embodiment of the apparatus for processing the inner and outer surfaces of metal tubes according to the present invention, FIG. 2 is a schematic longitudinal sectional side view taken along the low D line in FIG. 1, and FIG. FIG. 4 is a schematic longitudinal sectional side view taken along line mm of FIG. 4, and FIG. 4 is a schematic longitudinal sectional front view showing another embodiment of the present invention. 1... Roll roll support body, 2... Metal tube,
3... Rolling roll, 5... Plug, 6...
... Mandrel, 7, 8... Shaft, 9, 10... Guide roll, 23... Rod. Figure 4 Figure 1 Figure 2 Figure 3

Claims (1)

[Scope of Claims] 1. A plurality of rolling rolls that are rotatably arranged outside a metal tube at an angle of inclination with respect to the axis of the metal tube and are pressed against the metal tube, and the plurality of rolling rolls. a drive mechanism that revolves each of the metal tubes around the metal tube, and a plug that is positioned inside the metal tube at a position corresponding to the plurality of rolling rolls and gives a predetermined shape to the inner surface of the metal tube. A plurality of guide rolls are rotatably supported by a plurality of axes perpendicular to the axis of the metal tube, and are disposed adjacent to and downstream of the rolling roll, and grip the metal tube as a whole. Features: A device for processing the inner and outer surfaces of metal tubes. 2. The internal/external processing device for metal tubes according to claim 1, wherein at least one of the plurality of guide rolls is forcibly rotated by a drive mechanism.