JP2630006B2 - Manufacturing equipment for inner grooved pipe with unprocessed part - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an apparatus for manufacturing an internally grooved pipe, which is a high-performance heat transfer pipe applied to a heat exchanger such as an air conditioner or a refrigerator.
In particular, the present invention relates to an apparatus for manufacturing a grooved tube with an unprocessed portion, which can freely form a grooved portion and an unprocessed portion on the inner surface of the Kan, and can significantly improve the service life of the device itself as compared with the conventional example. Things.

[Prior Art] Smooth copper tubes have been used exclusively for heat transfer tubes used for heat exchange in refrigerators and air conditioners.
However, due to recent demands for resource saving and energy saving, recently, in order to enhance the heat transfer performance, the outer surface as shown in FIG.
The inner grooved tube 20 'having a groove is widely used.

And nowadays, there is a demand for cost reduction of the inner grooved tube 20 ', and the tube itself has been considerably thinned.

When connecting at the end of such a heat transfer tube, it is common to expand and connect the end of the tube in a bell-mouth shape, and as a result of the thinning, the groove has a notch effect during this expansion. There is a problem that the pipe is easily broken. Furthermore, when the terminals are connected by brazing, there is also a problem that the flow of the brazing occurs along the groove on the inner surface, which unnecessarily increases the consumption of the brazing.

To solve these problems, FIG. 4 (b)
As shown in the figure, the inner surface groove portion 21 in which the inner surface groove 21a is formed
And an unprocessed inner grooved tube 20 having such a non-processed portion 22 having no groove. This is to use this unprocessed part 22 in the end expansion part, the brazing part or the hairpin bending part that does not contribute much to heat transfer as described above, and try to solve the above-mentioned occurrence of cracks and excessive consumption of wax. Is what you do.

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

The floating plug 1 is inserted into the original tube 20A made of a long bare metal tube, and the original tube 20A is drawn and reduced in diameter by the die 10 held by the die holder 11 and the floating plug 1. A grooved plug 3 for forming an inner surface groove 21a on the inner surface of the tube via the rod 2 is provided at the front.

A plurality of balls 4, 4 for rotating and revolving in the circumferential direction of the tube to press the tube are arranged on the outer periphery of the tube where the grooved plug 3 is located. , 4 are given a pressing force toward the center of the tube by a pair of rolling holding rings 5, 6 held by the rotary head 9, and press the tube on the outer periphery of the grooved plug 3 in this state. With the groove of the grooved plug 3, continuous inner surface grooves 21a, 21a are formed on the inner surface of the tube. In the figure, reference numeral 7 denotes a shim for adjusting the distance between the holding rings 5 and 6 and adjusting the pressing force of the balls 4,4.

In the above, one press ring 5 of the pair of rolling press rings 5 and 6 is fixed to the rotary head 9 and does not move, but the other press ring 6 is fixed to the pusher 12. As it is moved in the direction of the solid arrow or the dotted arrow in the figure by the moving device 14,
It is configured such that the interval between the holding rings 5 and 6 can be changed. 13 is a bearing provided between the moving device 14 side which is a stationary body and the pusher 12 which is a rotating body,
Reference numeral 8 denotes a retainer arranged so that the balls 4, 4 do not contact each other.

Next, a method of manufacturing the inner grooved pipe 20 with the unprocessed portion by 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 balls 4,4, and the holding rings 5 and 6 are spaced apart by shims 7 to hold the balls 4,4.
Is given a maximum pressing force toward the center of the tube, and the above-described inner surface groove 21a is formed on the inner surface of the tube.

Thus, the holding surfaces 5a and 6a of the conventional holding rings 5 and 6 are formed into a tapered surface as shown in FIG. 5 or a spherical surface as shown in FIG.

In FIGS. 5 and 6, when the moving device 14 in FIG. 1 is driven to move the pusher 12 in the direction of the solid line arrow, the presser ring 6 moves by R _{1 in the} drawing, and The presser ring 6 moves to a position 6 'indicated by a dotted line in the figure, and a separation distance is formed between the presser rings 5 and 6. If this way distance, the pressing force for pressing the balls 4, 4 is released, balls 4 only FIG. 5 B ₂ or FIG. 6 B ₃ motion displacement to the position shown by the dotted line in the 5 and 6 FIG. As a result, the orbital radius of the spheres 4 becomes large, and the effect of pressing the tube against the grooved plug 3 to form the inner surface groove 21a is eliminated. While the presser ring 6 is moved in this way and the orbital radii of the balls 4, 4 are enlarged beyond a certain value, no groove is formed on the inner surface of the tube, and the unprocessed portion remains.

After forming the unprocessed portion of the required length, the pusher 12 is moved in the direction of the dotted arrow in the drawing by the moving device 14 in FIG. And the pressing force is again applied to the spheres 4, 4 so that the inner surface groove 21a is formed again. By appropriately repeating the above, an inner grooved tube with an unprocessed portion can be manufactured. Finally, FIG. 4 (a)
As shown in FIG. 3B, the rough polished portion 22A shown in FIG.
As shown in FIG. 6, the tube 20 having the unprocessed portion and the inner groove is completed by using the same outer diameter tube.

[Problems to be Solved by the Invention] According to the above, it is possible to manufacture an inner grooved tube with an unprocessed portion, but it cannot be said that the conventional example described above has no problems.

First, when the holding surfaces 5a, 6a are formed as tapered surfaces as shown in FIG. 5, the holding surfaces 5a, 6a and the ball 4 are in point contact, and the holding surfaces 5a, 6a and the ball 4 In both cases, there is a problem that wear progresses quickly and their life is shortened.

When the pressing surfaces 5a and 6a are spherical as shown in FIG. 6, the diameter of the spherical surface is substantially the same as the diameter of the sphere 4. It progress of the premature wear becomes surface contact by is prevented, if such diameter so that substantially identical, even if the pressing ring 6 is moved by R _1, the mobile width B ₃ of the revolution radius of the sphere 4 Only very small things can be taken. For this reason, the inner surface of the metal tube does not completely separate from the grooved plug 3, so that a shallow groove is formed, and a complete unprocessed portion cannot be formed. Increasing the moving width R ₁ of the ferrule 6 in order to avoid it, a corner portion formed at an end portion of the pressing surface 5a and 6a of the pressing ring 5 and 6
The ball 4 comes into contact with the balls 5b and 6b, resulting in damage to the ball 4 and premature wear of the device.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, to significantly improve the processing efficiency, and to greatly extend the life of the apparatus itself. An object of the present invention is to provide an apparatus for manufacturing a grooved tube.

Means for Solving the Problems The present invention focuses on the shape of the rolling press surface of a press ring that applies a pressing force to a ball, and the press surface of such a press ring has a spherical surface on the metal tube side. It is configured such that the outer side from a predetermined position is a tapered surface, or a portion corresponding to the tapered surface is configured as a spherical surface having a larger spherical radius than the metal tube side spherical surface instead of the tapered surface. is there.

[Function] If the metal tube side of the pressing surface of the rolling press ring is formed as a spherical surface, when a large pressing force for forming the inner surface groove is required, the ball and the pressing surface come into surface contact, and the wear is reduced accordingly. Is less likely to occur. On the other hand, if the rolling press ring is separated to increase the orbital radius of the sphere to form an unprocessed portion, the outer side of the press surface is formed as a tapered surface or a spherical surface with a large diameter. , The orbital radius of the ball can be made sufficiently large, and a complete unprocessed portion can be formed. Moreover, by forming a tapered surface or a spherical surface with a large diameter on the outer side from a predetermined position from the spherical surface of the pressing surface, the corner of the end of the pressing surface is widely present on the outer side, Even if the ring is sufficiently separated, there is no danger that the corners of the end of the holding surface will come into contact with the surface of the ball, and there is also a risk that the corners may scratch the surface of the ball or wear them both as in the conventional example. Completely eliminated.

[Example] Hereinafter, the present invention will be described with reference to examples.

FIG. 1 is an explanatory view showing an example of the configuration of the rolling press surface of the press ring 5 according to the present invention. FIG. 1 shows only the holding ring 5 side, but it goes without saying that the holding ring 6 side is also configured symmetrically.

In the present invention, the metal tube side of the holding ring 5 is centered.
Configured to spherical 5a ₁ comprising with a radius r ₁ from P _1. The spherical portion 5a ₁ is composed of substantially the same diameter as the outer peripheral surface of the sphere 4. On the other hand, if it is formed in the longitudinal or the spherical surface of the radius r ₁ to a point to Q ₁ about 50 ° with respect to the horizontal direction of the metal tube as shown in Figure, the radius r ₁ to a point to Q ₁ about the 50 ° Once formed in a spherical, tapered surface 5a ₂ is formed from the point to Q ₁ about the 50 ° in the direction as if the tangent of the spherical surface 5a _1.

FIG. 2 is an explanatory view showing a configuration near the holding ring portion of the apparatus according to the present invention in which the pair of holding rings 5 and 6 having the above-described rolling holding surfaces are arranged.

Shown in solid lines in FIG. 2, which shows the status of the holding ring 5 and 6 when forming the inner surface groove in the metal tube surface, the spherical 4 spherical portion 5a ₁ is in surface contact Ball 4
Is applied to the above-mentioned grooved plug 3 to form an inner groove on the inner surface of the tube.

Then, the holding ring 6 is moved to the second position by the moving device described above.
It is moved away by R ₁ in position 6 'shown by a dotted line in FIG. This movement of the R _1, balls 4 also moves to the position indicated by a dotted line in the figure, the revolution radius of the sphere 4 is sufficiently enlarged by B _1.

In the present invention, as described above, the revolving radius B ₁ of the sphere 4
When sufficient expansion only is made, spheres 4 will be in contact with the tapered surface 5a ₂ described above. By contacting this manner the tapered surface 5a _2, radius of revolution different from the case of FIG. 6 described above is sufficient expansion of only B ₁ is made, no longer has contact with grooved plug 3 and the metal pipe surface , An unprocessed portion 22A (see FIG. 4 (a)) is formed, and the unprocessed portion 22A is also contracted by the subsequent die 15 (see FIG. 7), so that the entire length as shown in FIG. 4 (b) is obtained. An inner grooved tube 20 with an unprocessed portion formed of an inner grooved portion 21 and an unprocessed portion 22 having the same outer diameter is formed.

In this case, while the unprocessed portion is being formed, the ball 4 and the tapered surface 5a ₂ are in point contact with each other, but the portion where the unprocessed portion 22 is formed has a short length. The point contact time is extremely short, and the risk of wear due to the point contact is extremely small.

However, if you want to avoid such point contact,
Instead of forming the tapered surface 5a _2, it may be configured as Figure 3.

That is, the tube side of the pressing ring 5 is approximately the same semi-r small spherical portion 5a ₁ consisting of ₁ form the radius of the sphere 4 as shown in FIG. 1, a position Q of about 45 ° from the metal pipe surface _{From 2} ,
Centers are formed in the large spherical 5a ₃ consisting of a large radius r ₂ is P _2.

By forming such a large spherical 5a _3, on expansion of the radius of revolution becomes sufficiently possible, 5a ₃ with respect to the tapered surface 5a ₂ is the area of contact only sphere 4 min which is the spherical surface As a result, the wear during the formation of the unprocessed portion becomes smaller, and the life of the device can be further extended.

Although the above is an example in which two surfaces having different radii are combined, the pressing surface may be configured with two or more spherical surfaces whose radius gradually increases.

[Effects of the Invention] As described above, with the apparatus according to the present invention, in the manufacture of an inner grooved tube with an unprocessed portion, the sphere contacts the spherical portion of the rolling holding surface of the holding ring during the inner groove machining. The wear of the ring and ball is small, and the life can be prolonged.However, while the unprocessed part is being formed, the ball moves to the tapered surface or large spherical surface of the holding surface, so the inscribed circle diameter of the ball is sufficient. The metal tube can be moved farther in the direction in which it becomes larger, the metal tube can be sufficiently separated from the grooved plug, and a complete unprocessed portion can be formed. In addition, it is possible to improve the life of the holding ring and the ball.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing the structure of a holding surface according to the present invention, and FIG.
FIG. 3 is an explanatory view showing a state in which the revolving circle of the ball is moved by the press ring shown in FIG. 1, FIG. 3 is an explanatory view showing another configuration of the press surface according to the present invention, and FIG. a) is a cross-sectional view showing the state of formation of the unprocessed portion, FIG. 5 (b) is a cross-sectional view showing the state of the unprocessed portion after contraction of the tube, and FIGS. FIG. 7 is an explanatory sectional view showing an apparatus for manufacturing a grooved pipe with an unprocessed portion, and FIG. 8 is an explanatory sectional view showing an inner grooved pipe. 1: Floating plug, 2: Rod, 3: grooved plug, 4: sphere, 5,6,6 ': ferrule, 5a _1, 6a _1: spherical portion, 5a _2, 6a _2: tapered face, 5a _3: Large spherical surface, 7: Shim, 8: Retainer, 9: Rotating head, 10: Pulling die, 11: Dice holder, 12: Pusher, 13: Bearing, 14: Moving device, 15: Finishing die, 16: Finishing die holder, 20 : Internal grooved tube with unprocessed portion, 21: grooved portion, 21a: internal groove, 22: unprocessed portion.

Claims (2)

(57) [Claims] A sphere that rotates on the outer circumference of the pipe and revolves in the circumferential direction of the pipe to press the pipe is disposed on the outer peripheral side of the grooved plug provided inside the metal pipe. Depending on the pressing force of the rotating ball, a continuous inner surface groove is formed on the inner surface of the metal tube by the groove of the grooved plug, while a pressing force on the metal tube is applied to the ball outside the ball. A pair of rolling press rings that are configured to be capable of being divided into two in the axial direction of the metal tube are arranged, and the sphere is moved in the radial direction of the tube by adjusting the facing distance between the pair of rolling press rings. In a device configured to be capable of increasing and decreasing the pressing force of the ball, a metal tube side of a pressing surface of the pressing ring is formed into a spherical surface, and an unprocessed portion is formed in which a side outside a predetermined position is formed as a tapered surface. Equipment for manufacturing inner grooved pipes. 2. The apparatus according to claim 1, wherein the tapered surface is replaced by another spherical surface having a larger spherical radius than the metal tube side spherical surface.