JPH03281013A - Manufacturing device for pipe with inner groove and non-worked part - Google Patents

Abstract

PURPOSE:To reduce the wear of the ring and the sphere and to improve the workability of the pipe with inner groove and with non-worked part and to improve the life of the press ring or sphere by making the metallic pipe side of the pressing surface of the press ring to the spherical surface and making the outer side from the prescribed position to the taper surface. CONSTITUTION:The spherical surface part 5a1 comes into face contact with the sphere 4, the pressurizing force for the plug with the groove is applied to the sphere 4 and the inner surface groove is formed in the inner surface of pipe. The press ring 6 is moved to the position 6' by R1 with the moving device, the sphere 4 is moved to the position displayed with the dotted line, the revolution radius of the sphere 4 is enlarged by B1, and contacts with the taper surface 5a2. Therefore, the revolutional radius is sufficiently enlarged by B1, the contact of the plug with groove with the inner surface of the metallic pipe is eliminated, the non-worked rough part 22A is formed, this non-worked rough part 22A is also contracted in diameter with the following dies, and the pipe 20 with inner groove and non-worked part which consists of the inner grooved part 21 and the non-worked part 22 of the same outer diameter over the total length is formed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an apparatus for manufacturing internally grooved tubes, which are high-performance heat transfer tubes applied to heat exchangers for air conditioners, refrigerators, etc. This invention relates to an apparatus for producing an internally grooved tube with an unprocessed part, which can freely form grooved parts and unprocessed parts on the surface, and which can significantly improve the service life of the apparatus itself compared to conventional examples. be.

[Prior Art] In the past, smooth copper tubes were mostly used as heat transfer tubes used for heat exchange in refrigerators and air conditioners. However, due to recent demands for resource and energy conservation,
Recently, in order to improve heat transfer performance, an inner grooved tube 20' having a smooth outer surface and a large number of fine continuous grooves 21a' on the inner surface, as shown in FIG. 8, has come into widespread use.

Nowadays, there is a demand for reducing the cost of such an internally grooved tube 20', and the tube itself is becoming considerably thinner.

When connecting the ends of such heat transfer tubes, it is common to expand the ends of the tubes into a bell mouth shape and then connect.
As a result of the thinning of the tube, there is a problem in that the groove becomes a notch effect during tube expansion, making it easy for the tube to crack. Furthermore, when the terminals are connected by brazing, there is a problem in that the solder flows along the grooves on the inner surface, unnecessarily increasing the consumption of the solder.

Therefore, in order to solve these problems, as shown in FIG. A tube with internal grooves 20 has been proposed. This unprocessed part 22 is used for the above-mentioned terminal expansion part, soldering part, or hairpin bending part that does not contribute much to heat transfer, in order to solve the above-mentioned problems such as the occurrence of cracks and excessive consumption of solder. It is something to do.

FIG. 7 is an explanatory sectional view showing a specific example of a manufacturing apparatus for such an internally grooved tube 20 with an unprocessed portion.

The floating plug 1 is inserted into the inside of the raw tube 20A made of a long bare metal tube, and the raw tube 2O is connected to the die 10 held by the die holder 11 and the floating plug 1.
A is drawn and diameter-reduced, and a grooved plug 3 is provided in front of the floating plug 1 to form an inner groove 21a on the inner surface of the tube via a rod 2.

On the outer periphery of the pipe where such a grooved plug 3 is located, a plurality of balls 4, 4 that rotate on their own axis and revolve in the circumferential direction of the pipe to compress the pipe are arranged. .4 is by applying a pressing force toward the center of the tube by a pair of rolling retaining rings 5.6 held on the rotating head 9, and pressing the tube around the outer periphery of the grooved plug 3 in this state. Continuous inner grooves 21a, 21 are formed on the inner surface of the tube by the grooves of the grooved plug 3.
A is to be molded. In the figure, reference numeral 7 denotes a shim for adjusting the interval between the presser rings 5 and 6 and adjusting the pressing force of the balls 4.4.

In the above, one of the pair of rolling press rings 5 and 6 is fixed to the rotary head 9 and does not move, while the other press ring 6 is fixed to the pusher 12. The space between the presser rings 5 and 6 can be changed as the holding rings 5 and 6 are moved by the moving device 14 in the direction of the solid line arrow or the dotted line arrow in the figure. 13 is a bearing provided between the moving device 114, which is a stationary body, and the bushing 12, which is a rotating body, and 8 is a retainer arranged so that the balls 4.4 do not come into contact with each other.

Next, a method for manufacturing the internally grooved pipe 20 with an unprocessed portion using the apparatus configured as described above will be specifically described.

The holding rings 5 and 6 have holding surfaces 5a and 6a for generating a pressing force on the ball 4.4, and when the holding rings 5 and 6 are held apart by the shim 7, the ball 4.4 is pressed against the center of the tube. The maximum pressing force in the direction is applied, and the above-mentioned inner groove 21a is formed on the inner surface of the tube.

Therefore, the pressers 5a and 6a of the conventional presser rings 5 and 6 were formed into a tapered surface as shown in No. 5rgJ or a spherical surface as shown in FIG.

5 and 6, when the moving device 14 shown in FIG. 1 is driven and the pusher 12 is moved in the direction of the solid line arrow, the presser ring 6 is moved by R5 in each figure as a result of this movement. The presser ring 6 moves to the position 6' shown by the dotted line inside, and a separation distance is created between the presser rings 5 and 6.

When the separation distance is established in this way, the pressing force that presses the balls 4 and 4 is released, and the ball 4 shifts to the position shown by the dotted line in FIGS. 5 and 6, and the tube moves only by B2 in FIG. Since they are separated from the surface, the radius of revolution of the balls 4, 4 becomes large, and the action of pressing the pipe against the grooved plug 3 to form the inner groove 21g disappears. While the presser ring 6 is moved in this manner and the radius of revolution of the sphere 4.4 is expanded beyond a certain value, no groove is formed on the inner surface of the tube and it remains an unprocessed portion.

After forming the unprocessed part of the required length, the pusher 12 is moved in the direction of the dotted arrow in the figure by the moving device 14 in FIG. 7, the presser ring 6 is brought into contact with the shim 7, and the revolution of the ball 4. By reducing the radius and applying a pressing force to the ball 4.4 again, the inner groove 21a can be formed again. By appropriately repeating the above steps, an internally grooved tube with an unprocessed portion can be manufactured. Finally, the roughly processed portion 22A shown in FIG. 4(a) is passed through the finishing die 15 held in the die holder 16 to shrink the tube, and as shown in FIG. By doing this, the inner grooved tube 20 with an unprocessed portion is completed.

[Problems to be Solved by the Invention] Although it is possible to manufacture an internally grooved tube with an unprocessed portion in the manner described above, it cannot be said that there are no problems in the conventional example described above.

First, when the presser surfaces 5a, 6a are configured as tapered surfaces as shown in FIG.
Since the holding surfaces 5a, 6a and the ball 4 are in point contact with each other, there is a problem in that both the holding surfaces 5a, 6a and the ball 4 wear rapidly, shortening their lifespan.

Further, when the pressing surfaces 5a, 6a are spherical as shown in FIG. 6, the diameter of the spherical surface is approximately the same as the diameter of the sphere 4. This creates surface contact and prevents the premature wear described above, but if the diameters are almost the same like this,
Even if the holding ring 6 is moved by R3, the orbital radius of the ball 4 is still moving B.

can only pick up very small items. For this reason, the inner surface of the metal tube does not completely separate from the grooved plug 3, and a shallow groove is formed, making it impossible to form a complete unprocessed part.

In order to avoid this, if R1 is increased while the presser ring 6 is moving, the presser surfaces 5a and 6a of the presser rings 5 and 6 are
A corner 5b formed at the end of the corner 5b.

6b and ball 4 come into contact, resulting in damage to ball 4,
This will accelerate the wear and tear of the equipment.

The object of the present invention is to provide a new inner surface with an unprocessed part that can solve the problems of the prior art as described above, significantly improve machining efficiency, and greatly extend the life of the device itself. The present invention aims to provide a manufacturing device for grooved pipes.

[Means for Solving the Problems] The present invention focuses on the shape of the rolling holding surface of the holding ring that applies pressing force to the sphere, and the holding surface of such a holding ring has a spherical surface on the metal tube side. It is configured so that the side outward from a predetermined position is a tapered surface, or instead of a tapered surface, the part corresponding to the tapered surface is configured as a spherical surface with a larger radius than the spherical surface on the metal tube side. be.

[Function] If the metal tube side of the holding surface of the rolling holding ring is configured as a spherical surface, when a large pressing force is required to form the inner groove, the ball and the holding surface will come into surface contact, which will reduce wear. is less likely to occur. On the other hand, when the rolling presser ring is spaced apart in an attempt to increase the orbital radius of the sphere to form an unprocessed part, the outer side of the presser surface is formed into a tapered surface or a spherical surface with a large diameter. , it becomes possible to make the radius of revolution of the sphere sufficiently large, and it is possible to form a completely unprocessed part. Moreover, by forming a tapered surface or a spherical surface with a large diameter on the outside from a predetermined position from the spherical surface of the presser surface, the corner of the end of the presser surface is located on the outer side of the presser surface. Even if the rings are spaced sufficiently apart, there is no risk that the end corners of the presser surface will come into contact with the surface of the ball, and there is no risk of the corners damaging the surface of the ball or damaging both, as in the conventional example. completely resolved.

[Example] The present invention will be described below with reference to Examples.

FIG. 1 is an explanatory diagram showing an example of the structure of the rolling press surface of the press ring 5 according to the present invention. Figure 1 shows the presser ring 5.
Although only the side is shown, it goes without saying that the presser ring 6 side is also constructed symmetrically with this side.

In the present invention, the metal tube side of the presser ring 5 has a center P
, a spherical surface 5a having a radius r from .

It is composed of This spherical portion 5a+ has approximately the same diameter as the outer peripheral surface of the sphere 4. On the other hand, as shown in the figure, if a spherical surface with a radius of 1 is formed up to a point Qi at about 50° with respect to the longitudinal direction, that is, the horizontal direction, then the point Q at about 50°
A tapered surface 5az is formed in a direction that is tangent to the spherical surface 5a.

FIG. 2 is an explanatory diagram showing the structure of the vicinity of the presser ring portion of the device according to the present invention, in which the pair of presser rings 5 and 6 having rolling presser surfaces as described above are arranged.

The solid line in FIG. 2 shows the condition of the holding rings 5 and 6 when an inner groove is formed on the inner surface of the metal tube, and the spherical portion 5a is in surface contact with the ball 4. Ball 4
A pressing force is applied to the grooved plug 3 described above, and an inner groove is formed on the inner surface of the tube.

Next, the presser ring 6 is moved and separated by R to the position 6' shown by the dotted line in FIG. 2 by the above-mentioned moving device. Due to this movement of R, the ball 4 also moves to the position shown by the dotted line in the figure, and the orbital radius of the ball 4 is B,
only sufficiently expanded.

In the present invention, as mentioned above, B of the orbital radius of the sphere 4,
When the sphere 4 is sufficiently expanded, it comes into contact with the above-mentioned tapered surface 5a2. By contacting the tapered surface 5a2 in this way, unlike the case shown in FIG. 6 described above, the revolution radius is sufficiently expanded by B, and the grooved plug 3 no longer contacts the inner surface of the metal tube. A roughly processed portion 22A (see FIG. 4(a)) is formed,
The subsequent die 15 (see Fig. 7) roughens the rough processing part 2.
2A is also shrunk to form an internally grooved tube 20 with an unprocessed part, which consists of an internally grooved part 21 and an unprocessed part 22 having the same outer diameter over the entire length, as shown in FIG. 4(b).

In this case, the ball 4 and the tapered surface 5az come into point contact during the formation of the unprocessed part, but the forming part of the unprocessed part 22 has a short length, and due to its nature, most of the tube is closer than the grooved part 21. The time required for point contact is extremely short, and the risk of wear due to point contact is extremely small.

However, if it is desired to avoid such point contact, a configuration as shown in FIG. 3 may be used instead of forming the tapered surface 5a2.

That is, as shown in FIG. 1, on the tube side of the retaining ring 5, there is a small spherical surface portion 5a having a radius r that is approximately the same as the radius of the sphere 4.
, is formed at a position Q2 approximately 45° from the metal tube surface.
A large spherical surface 5a having a large radius r2 and whose center is P2 is formed.

By forming such a large spherical surface 5ai, it is possible to sufficiently expand the radius of revolution, and the contact area with the sphere 4 is increased by the amount that 5ai is a spherical surface with respect to the tapered surface 5a2. The wear during the formation of the unprocessed portion is reduced accordingly, making it possible to further extend the life of the device.

Although the above is an example in which two surfaces with different radii are combined, the presser surface may be configured with two or more spherical surfaces with gradually increasing radii.

[Effects of the Invention] As described above, with the apparatus according to the present invention, in the production of an internally grooved tube with an unprocessed part, the balls come into contact with the spherical part of the rolling press surface of the presser ring during the process of forming the internal grooves. , there is less wear on the ring and the ball, which can lengthen its life. On the other hand, while the unprocessed part is being formed, the ball moves to the tapered surface of the holding surface or to the large spherical surface, so the diameter of the orbital inscribed circle of the ball is sufficient. The metal tube can be moved far enough away from the grooved plug to form a complete unprocessed part, and the workability of the internally grooved pipe with the unprocessed part is improved. Also, it becomes possible to improve the life of the holding ring and the ball.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the configuration of the presser surface according to the present invention, and FIG.
The figure is an explanatory diagram showing how the ball is moved for revolution by the presser ring shown in Fig. 1, Fig. 3 is an explanatory diagram showing another configuration of the presser surface according to the present invention, and Fig. 4 ( a) is a cross-sectional view showing the state of formation of the rough-processed part, FIG. FIG. 7 is an explanatory cross-sectional view showing a manufacturing apparatus for a grooved tube with an unprocessed part, and FIG. 8 is an explanatory cross-sectional view showing an inner grooved tube. 1: Floating plug, 2: Rod, 3: Grooved plug, 4: Ball, 5.6.6+ presser ring, 5al, 6a+: Spherical section, 5 ax * 6 a2: Tapered surface section, 5a, Two-person spherical section, 7: Shim, 8: Retainer, 9: Rotating head, 10: Drawing die, 11: Die holder, 12: Butcher 13: Bearing, 4 5 6 0 1 1a 2 Moving device, Finishing die, Finishing die holder, With unprocessed part Internally grooved pipe, grooved section, internal groove, unprocessed section.

Claims (2)

[Claims] (1) A ball that rotates on the outer circumference of the tube and revolves in the circumferential direction of the tube to compress the tube is placed on the outer circumferential side of the grooved plug provided inside the metal tube, and Depending on the pressing force of the ball, the groove of the grooved plug forms a continuous internal groove on the inner surface of the metal, while the outside of the ball is configured to be able to apply a pressing force to the metal tube. A pair of rolling retainer rings are arranged which are divided into two in the axial direction of the metal tube, and the ball is moved in the radial direction of the tube by adjusting the facing interval of the pair of rolling retainer rings. An apparatus for producing an internally grooved tube with an unprocessed part, in which the pressing force of the holding ring is configured to have a spherical surface on the metal tube side and a tapered surface on the side outward from a predetermined position. . (2) An apparatus for manufacturing an internally grooved tube with an unprocessed portion, in which the tapered surface is replaced by a separate spherical surface having a larger radius than the spherical surface on the metal tube side.