JP2002126846A - Manufacturing device for roll for form rolling for form rolling work and heat transfer tube with groove on internal face - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a roll for a form rolling from being cracked by depressing elusion of the binding phase of cemented carbide. SOLUTION: The manufacturing device of a heat transfer tube with grooves at the internal face is provided with a fin form rolling 4 and a receiving roll 6 for form rolling fins on one face of cooper sheet material, a lubricant nozzle 3 supplying a lubricant, a plurality of forming rolls 10 for forming the plate sheet material T tubular, and welding structures 14, 16 for welding the both end edges of the plate sheet materials formed tubular. The roll body 32 of the fin form rolling 4 is made of WC-Ni base cemented carbide containing tungsten carbide (WC) and Ni and the mean particle size of WC in the WC-Ni base cemented alloy is 0.5-2 μm, the Ni content is 10-30 wt.%, Co content is 2 wt.% or less. The roll body 32 is provided with a plurality of divided rolls 4A-4D and they are jointed together in diffused junction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roll for rolling and an apparatus for manufacturing a heat transfer tube with an inner surface groove, and more particularly to a technique for preventing roll breakage during rolling.

[0002]

2. Description of the Related Art An inner grooved heat transfer tube is a metal tube having fine grooves and fins formed on an inner surface thereof, and is widely used as a component of a heat exchanger such as a refrigerator or an air conditioner. As one of the methods for manufacturing these heat transfer tubes with inner grooves, there is a method using electric sewing. In this method, a strip-shaped metal plate material is rolled with a roll for forming a groove on the outer peripheral surface to form fine grooves and fins on the surface of the plate material. Roll forming on the strip material,
Roll into a tube with the fin-forming surface inside. Further, the rolled sheet material is heated by an induction heating coil, and both side edges of the sheet material are welded to each other to form an inner grooved heat transfer tube.

[0003]

From the viewpoint of further improving the heat exchange efficiency of the heat transfer tube with the internal groove, the present inventors have made the width of the fin formed inside the heat transfer tube with the internal groove small and reduced. , The tall fins have been improved. However, it has been found that as the fins to be rolled are made thinner and higher, the frequency of occurrence of minute chipping (chipping) in the ridges (groove partition walls) of the roll for rolling is increased. The protruding ridges of the roll for roll forming are portions that form grooves on the inner surface of the heat transfer tube with an inner groove, and when chipping occurs at this portion, adjacent fins and fins are locally continuous to form a defective portion. Occurs. Although such defects have negligible effect on heat exchange efficiency, their mechanical strength is different from other parts, so expand the inner grooved heat transfer tube to fix the radiation fins on the outer periphery of the inner grooved heat transfer tube. When processed, the outer peripheral surface of the inner grooved heat transfer tube rises in correspondence with the above-mentioned defective portion, and there is a problem that the appearance is impaired.

[0004] The inventors of the present invention have studied in detail the mechanism of the occurrence of chipping in the rolling roll during fin rolling, and have elucidated the following unknown causes.

[0005] The conventional roll for roll forming is most commonly used among cemented carbides, and is formed of a WC-Co-based cemented carbide having the highest strength. A general WC-Co cemented carbide contains 70 to 95 wt% WC as hard dispersed particles,
It contains 5 to 30 wt% of Co as a binder component, and the average particle size of WC is about 1 to 4 μm.

[0006] As described above, when a roll for rolling is formed from a cemented carbide containing cobalt as a binder phase component, cobalt has a good affinity for copper, which is a main component of the strip material, and therefore, the roll is formed. In the process in which the forming roll rolls the plate material, the copper of the plate material slightly dissolves in the cobalt binder phase on the roll surface. In addition, when performing fin rolling, it is necessary to supply a soluble oil to the rolling site for lubrication and cooling to perform the rolling process.However, the cobalt binder phase in which copper is dissolved in solid is dissolved by the soluble oil. Because it is easy to be
The cobalt bonded phase gradually elutes into the soluble oil. Furthermore, as the fins become thinner and higher, the working ratio of the rolling roll increases, so that the binder phase elution phenomenon becomes more remarkable, and each ridge of the rolling roll becomes thinner in the first place. As a result, the strength of the ridge becomes more susceptible to a decrease in strength due to elution of the binding phase from the surface of the ridge, and as a result, the frequency of chipping of the ridge increases.

[0007] That is, the problem of chipping of the roll for rolling is that (1) the cemented carbide uses a cobalt binder phase, and (2) the material to be rolled is formed of copper or a copper alloy. (3) The use of a lubricating liquid such as soluble oil for rolling, and (4) The fins to be rolled are becoming thinner and higher. Turned out to be.

The present invention has been made on the basis of the above findings, and has as its object to prevent chipping of a roll for forming by suppressing the elution of a binder phase of a cemented carbide.

[0009]

In order to solve the above-mentioned problems, a roll for rolling according to the present invention comprises a roll body having an uneven structure for rolling on the outer peripheral surface. , Tungsten carbide as hard dispersed particles (W
C) and a WC-Ni-based cemented carbide containing Ni as a binder phase;
The average particle size of C is 0.5-2 μm, the content of Ni is 10-30 wt%, and the content of Co is 2 wt% or less.

According to such a roll for roll forming, nickel is used as a binder phase component instead of cobalt, which has a good affinity for copper. In addition, it is possible to prevent a phenomenon in which copper is dissolved in the binder phase on the roll surface to promote the elution of the binder phase into the lubricating liquid. Therefore, it is possible to suppress a decrease in the strength of the cemented carbide due to the elution of the binder phase from the roll surface, reduce the frequency of occurrence of chipping of the uneven structure, and extend the roll life.

On the other hand, the apparatus for manufacturing a heat transfer tube with inner grooves according to the present invention comprises a fin rolling roll and a receiving roll for rolling a fin on one surface of a metal strip by rolling the metal strip. A lubricating liquid supply mechanism for supplying a lubricating liquid to a contact point between the fin rolling roll and the plate material, and a plate material having the fin formed thereon such that the fin is located on the inner peripheral side. A plurality of forming rolls for forming into a tubular shape, and a welding mechanism for heating and butt-welding both end edges of the plate-shaped strip material formed into a tubular shape, wherein the fin rolling roll is a roll The roll body comprises WC-N containing tungsten carbide (WC) as hard dispersed particles and Ni as a binder phase.
The WC-Ni-based cemented carbide is formed of an i-based cemented carbide, the average particle size of WC in the WC-Ni-based cemented carbide is 0.5 to 2 μm, the content of Ni is 10 to 30 wt%, and the content of Co is 2wt%
It is characterized by the following.

According to such an apparatus for manufacturing a heat transfer tube with internal grooves, nickel is used as a binder phase component of a roll for forming work instead of cobalt having a good affinity for copper. Also in the case of rolling processing of a sheet material containing copper, the phenomenon that copper forms a solid solution with the binder phase on the roll surface and the binder phase elutes into the lubricating liquid can be reduced. Therefore, it is possible to suppress the decrease in strength due to the elution of the binder phase from the roll surface, and to reduce the frequency of occurrence of chipping of the roll for roll forming,
It is possible to reduce the occurrence of abnormal shape of the fin due to the lack of the roll.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment] FIG. 1 is a side view showing a first embodiment of an apparatus for manufacturing a heat transfer tube with an inner surface groove according to the present invention. First, an outline of the apparatus will be described. In the figure, reference numeral 1 denotes an uncoiler, which continuously feeds out a strip T of copper or copper alloy having a constant width and a constant thickness. The fed strip material T is passed between a pair of press rolls 2 and a fin roll 4 and a receiving roll 6 which are arranged opposite to each other.
As shown in (1), fins 35 and grooves inclined with respect to the longitudinal direction are formed on the surface of the strip material T, and the back surface of the strip material T is kept smooth. Fin roll 4
A lubricating liquid nozzle 3 is installed on the upstream side, and a lubricating liquid is continuously supplied from a lubricating liquid supply mechanism (not shown), and a lubricating liquid such as a soluble oil is supplied to a rolling portion.

The sheet material T rolled by the fin roll 4 and the receiving roll 6 passes through a pair of rolls 8 shown in FIG.
And gradually rolled into a tube. Further, the gap amount between the both ends to be abutted by the rolling separator 12 is kept constant, and then the both sides are heated by passing through the induction heating coil 14. The plate material T which has been formed into a tube and heated is passed through a pair of squeeze rolls 16, and is pressed from both sides so that both heated side edges abut and are welded. Since a bead is formed by the protruding molten material on the outer peripheral surface of the heat transfer tube P thus welded, a bead cutter 18 for cutting the bead is provided.

The heat transfer tube P from which the beads have been cut is placed in the cooling tank 20.
After being forced cooled through the sizing rolls 22, the sizing rolls 22 arranged in pairs are passed through the sizing rolls 22 to reduce the diameter to a predetermined outer diameter. Further, the heat transfer tube P having a reduced diameter is wound by the rough coiler 24 and sent to the next step.

Next, the fin roll 4 which is a main feature of the present invention will be described. 2 and 3 are a front view and a cross-sectional view showing the fin roll 4 of the first embodiment. The fin roll 4 has a roll shaft 26 and a roll body fixed to the roll shaft 26. 32 and a pair of side rolls 3 arranged on both sides of the roll body 32
0.

As shown in FIG. 3, an annular flange portion 26A is integrally formed on the outer peripheral surface on one end side of the roll shaft 26, and a male screw portion 26B is formed on the outer peripheral surface on the other end side. . On the outer peripheral surface between the flange portion 26A and the male screw portion 26B, an annular side roll 30, a cylindrical roll body 32, and an annular side roll 30 are sequentially passed, and the nut 28 is screwed into the male screw portion 26B. By doing so, the roll main body 32 is fixed to the roll shaft 26. The inner diameter of the roll body 32 at room temperature is made slightly smaller than the outer diameter of the outer circumferential surface of the roll shaft, and the roll body 32 is heated to a high temperature and then baked on the outer circumferential surface to further prevent rattling. You may.

As shown in FIG. 4, each side roll 30 has a smooth portion 36 having a fixed width on each side edge of the plate material T.
Play a role in forming These smooth portions 36 have the effect of increasing the welding stability during electric resistance welding.

As shown in FIG. 2, on the outer peripheral surface of the roll main body 32, a number of spiral fin rolling grooves 34 are formed in parallel at a constant pitch over the entire surface. Fin rolling groove 3
4 is a value determined according to the characteristics required for the heat transfer tube P, and is not limited in the present invention, but is 5 to 25 in a general heat transfer tube with an inner groove.
゜ is preferred. The depth of the fin rolling groove 34 is not limited, but is generally about 0.1 to 0.3 mm. The higher the fin, that is, the deeper the fin rolling groove 34 is, the more likely it is that the roll is chipped, so that the effect of the present invention is remarkable. The cross-sectional shape of the fin rolling groove 34 is not limited, and may be a triangular cross-section (the tip may be rounded or pointed), a trapezoidal shape, or a semicircular shape. .

Although the dimensions of the heat transfer tube P with an inner groove are not limited in the present invention, when the values of a general heat transfer tube are exemplified, the outer diameter is about 3 to 15 mm, and the outer diameter of the tube wall at the bottom of the groove is small. The thickness is about 0.15 to 0.5 mm. In addition, sheet material T
Preferably, copper or a copper alloy is used as a material of the heat transfer tube P with an inner surface groove, and among them, phosphorus deoxidized copper (for example, JIS1220 alloy), oxygen-free copper, and the like are particularly preferable.

The main feature of this embodiment is that the roll body 32
Is formed of a WC-Ni-based cemented carbide containing tungsten carbide (WC) as hard dispersed particles and Ni as a binder phase. The average particle size of WC in the WC-Ni-based cemented carbide is 0.5-2 μm, the content of Ni is 10-30 wt%, and the content of Co is 2 wt%.
It is as follows.

If the average grain size of WC in the WC-Ni-based cemented carbide is larger than 2 μm, there is a problem that cracks are likely to occur, and if it is smaller than 0.5 μm, the growth of crystal grains is unavoidable. Is difficult. More preferably, W
The average particle size of WC in the C-Ni cemented carbide is 0.5 to 1 μm.
m.

If the content of Ni in the WC-Ni-based cemented carbide is more than 30, the strength of the cemented carbide decreases, and 10 wt%
If it is smaller than this, there occurs a problem that the cemented carbide becomes brittle due to an insufficient bonding phase. More preferably, the content of Ni in the WC-Ni-based cemented carbide is 10 to 20 wt%.

When the content of Co in the WC-Ni cemented carbide is more than 2 wt%, the phenomenon of copper diffusing into cobalt and the phenomenon that the cobalt binder phase elutes into the lubricating liquid cannot be sufficiently prevented. And the effect of the present invention is reduced. A more preferred Co content is 1 wt% or less. Of course, cobalt may not be contained at all. The WC-Ni-based cemented carbide further contains 0.5% each of Cr, Mo, V, and the like.
It may be contained in a range of less than wt%.

WC as a material of the roll body 32
-Ni cemented carbide is preferably transverse rupture strength 300 kgf / mm ² or more conditions are satisfied.

In this embodiment, as a material of the roll body 32, a WC-Ni-based cemented carbide using nickel as a binder component instead of cobalt having good affinity for copper is used. As shown in FIG. 4, when the fin 35 is formed by rolling the plate material T, the copper in the plate material T hardly forms a solid solution with the binder phase on the surface of the roll body 32. Can be reduced to elute into lubricating fluid such as soluble oil. As a result, a decrease in strength due to elution of the binder phase from the roll surface can be suppressed, the frequency of occurrence of chipping of the ridge portion can be reduced, and the roll life can be extended. In addition, since the abnormal shape of the fin can be prevented, it is possible to manufacture a heat transfer tube with an inner groove having excellent aesthetic appearance with high productivity.

[Second Embodiment] FIGS. 5 to 7 show a fin roll 4 according to a second embodiment of the present invention. The fin roll 4 of this embodiment is for manufacturing a heat transfer tube with an inner groove having a W-shaped fin 35 as shown in FIG. 8, and the roll body 32 of the fin roll 4 is Four divided rolls 4A forming an annular shape
4D, and each of the split rolls 4A to 4D is formed of the WC-Ni-based cemented carbide described above.

Then, as shown in FIG.
, A side roll 30, an integrally joined divided rolls 4A to 4D, and a side roll 30 are sequentially passed through the outer peripheral surface between the flange portion 26A and the male screw portion 26B, and the nut 2
The split rolls 4 </ b> A to 4 </ b> E are fixed to the roll shaft 26 by screwing 8 into the male screw portion 26 </ b> B. The inner diameter of the divided rolls 4A to 4E at room temperature is made slightly smaller than the outer diameter of the outer peripheral surface of the roll shaft 26, and the divided rolls 4A to 4E are
E may be heated to a high temperature and then baked on the outer peripheral surface to further prevent rattling. Other configurations are the same as those of the first embodiment.

On the outer peripheral surfaces of the division rolls 4A to 4D, a large number of spiral fin rolling grooves 34 are formed in parallel at a constant pitch over the entire surface. The fin rolling grooves 34 of the adjacent divided rolls are opposite in the sign of the inclination angle, that is, are symmetrical with respect to the joining surface of the divided rolls. Thus, when the sheet material T is rolled, As shown in FIGS. 5 and 8, a large number of W-shaped fins 35 and grooves are formed at a constant pitch. The absolute value of the inclination angle of the fin rolling groove 34 may be different for each divided roll.

The feature of this embodiment is that divided rolls 4A to 4A
4D is diffusion bonded to each other. That is, the contact surfaces of the split rolls 4A and 4B, 4B and 4C, 4C and 4D are diffusion-bonded. In the case of a conventional split-type roll, the split rolls cannot be diffusion-bonded to each other. The reason is that if the divided rolls are mechanically pressed from both sides and fixed without diffusion bonding, there will be no trouble during rolling in normal use, and if the divided rolls are joined to each other, damage will not occur. This is because it becomes impossible to replace the resulting split rolls individually.

At first, the present inventors also tried means for strongly pressing and fixing each divided roll by a fastening mechanism. However, no matter how much the mechanical fastening force is increased, a defect may occur at the boundary between the divided rolls. Have not been able to prevent the problem sufficiently. As a result of further research, when the divided rolls 4A to 4D are diffusion-bonded, the individual divided rolls cannot be exchanged, but the chipping of the rolls can be suppressed. I found out that there was too much to make up for the inability to exchange.

To perform diffusion bonding, each of the divided rolls 4A
After aligning the positions of the 4D fin rolling grooves 34, these are pressed against each other by using a jig and brought into close contact with each other. Heat to near crystallization temperature. Thereby, the division roll 4
Diffusion of atoms occurs on the contact surfaces of A to 4D, and the divided rolls 4A to 4D are joined to each other. By adopting the diffusion bonding, the division rolls 4A to 4D formed of a high melting point material such as a cemented carbide can be easily bonded.
Further, according to the diffusion bonding, the deformation of the bonding surface is extremely small, and there is no inclusion such as a brazing material. Therefore, the shape accuracy does not decrease as compared with the case where the diffusion bonding is not performed.

By the diffusion bonding of the divided rolls 4A to 4D in this manner, the end faces of the divided rolls 4A to 4D are firmly joined over the entire surface, and the groove partition walls abutted at the bent portions of the fin rolling grooves 34. Even the end faces of the (protrusions between the fin rolling grooves 34) are integrally connected. Therefore, when the rolling line speed is increased, and / or
Alternatively, even when an excessive pressure is applied to the bent portion of the fin rolling groove 34 due to the material flow, the ends of the groove partition walls butted by the bent portion are less likely to be lost. Therefore, the roll body 3
Also when 2 is a split type, the life of the fin roll 4 can be extended in combination with the effect of using the WC-Ni cemented carbide.

In this embodiment, since the side rolls 30 are not diffusion-bonded to the split rolls 4A to 4D, replacement of the side rolls 30 is easy. The side rolls 30 have flat portions 36 having a fixed width on both side edges of the plate material T.
The width and thickness of these flat portions 36 have a great effect on ERW. Therefore,
If the material or thickness of the plate material T is changed, it is necessary to change the size or shape of the side roll 30 in order to adjust the width or thickness of the flat portion 36. If so, it can be easily changed. In advance, the side roll 30
It is advisable to prepare several types with different sizes.

The outer peripheral surfaces of the split rolls 4A and 4D are provided near the side rolls 30 near the side rolls 30.
A conical surface whose outer diameter gradually decreases toward the zero side may be formed. In this case, the thickness (bottom thickness) of the strip material T in the groove after rolling is formed so as to gradually increase toward both side edges of the strip material T. In this case, further, in the same portion, the depth of the fin rolling groove 34 of the divided rolls 4A and 4D is formed so as to gradually decrease toward the side roll 30, and the fin 35 formed on the plate material T is formed. The height may be adjusted to decrease as it approaches the weld. Further, the outer peripheral surface of the side roll 30 may be a tapered surface whose outer diameter decreases outward in the axial direction,
Thereby, the thickness of the plate material in the flat portion 36 may be set to be larger than the thickness of the plate material T in the groove. In each of these cases, it is possible to increase the strength near the weld.

According to the apparatus for manufacturing a heat transfer tube with an inner surface groove having the above structure, the divided rolls 4A to 4D are diffusion-bonded to each other, so that the end faces of the divided rolls 4A to 4D are firmly bonded over the entire surface. Then, even the end faces of the respective groove partition walls butted at the bent portion of the fin rolling groove 34 are integrally connected. Therefore, when the line speed of the rolling is increased, when a tall fin is rolled, and / or when excessive pressure is applied to the bending portion of the fin rolling groove 34 due to the material flow, the bending portion may be used. The ends of the butted groove partition walls are unlikely to be chipped, and the WC-Ni-based cemented carbide is used as the material of the split rolls 4A to 4D, and the corrosion resistance of the roll main body 32 is improved, and the life of the fin rolls is extended. Can be extended.

[Third Embodiment] FIG. 9 shows a fin roll 4 used in a device for manufacturing a heat transfer tube with an inner surface groove according to a third embodiment of the present invention. In this embodiment, the split roll 4
A to 4D are common to the second embodiment in that they are diffusion-bonded to each other, but the diameters of the outer peripheral surfaces of the divided rolls 4A to 4D are not constant, and the mating surfaces of the divided rolls 4A and 4B Near and divided roll 4C and divided roll 4D
In the vicinity of the mating surface with the rolls 4A to 4D
The difference is that the outer diameter is relatively reduced. Therefore, two concave portions 40 are formed on the outer peripheral surface of the fin roll 4.
Are formed over the entire circumference.

The mating surfaces of the split rolls 4A and 4B and of the split rolls 4C and 4D are individually formed when the fins 35 are rolled into the sheet material T by the fin rolls 4. The fin 35 corresponds to a position where the fin 35 is formed last, and a material flow is generated toward these mating surfaces as shown by an arrow R in FIG. For this reason, in the region S on the inner surface of the inner grooved heat transfer tube shown in FIG. 8, the flowed material is concentrated and the height of the fins 35 tends to be excessively large. In this case, chipping easily occurs. The third embodiment is for solving this problem.

When the direction of the axis of the fin roll 4 is reversed, the material flows toward both ends and the center of each W-shaped fin 35. In this case, Near the mating surface between the side roll 30 and the split roll 4A, near the mating surface between the split roll 4B and the split roll 4C, and the split roll 4D and the side roll 30.
In the vicinity of the mating surface with the rolls 4A to 4D
Should be relatively reduced, so that three concave portions 40 should be formed on the outer peripheral surface of the fin roll 4. However, when rolling is performed in a direction in which the material flows toward both ends and the center of each W-shaped fin 35, deformation due to the material flow is likely to occur at both side edges of the strip material T. , It may interfere with later welding,
It is preferable to perform the rolling in the direction shown in FIG. 5, that is, the direction in which the material does not flow toward both side edges of the strip material T. The same applies to the case where the fins 35 are formed not in a W-shape but in a V-shape, or when formed in a “VVV” shape bent five times.

The cross section of the recess 40 has a wide V
The shape may be a letter shape or a rounded shape. The width W1 and the depth D1 of the concave portion 40 are determined when the fins 35 are rolled by the fin rolling rolls 4 and the mating surfaces of the split rolls 4A and 4B and the split rolls 4C and 4D. The material flow generated toward the surface should be set so as to be able to be absorbed in these concave portions 40, and so that the fin 35 is not locally raised in a region corresponding to the mating surface.

The width W1 and the depth D1 of the concave portion 40 satisfying this condition are not limited, but in the case of a general heat transfer tube with an inner surface groove, the depth D1 is 3 to 20% of the thickness of the plate material T. Preferably, the content is more preferably about 5 to 10%. If the depth D1 of the concave portion 40 is too small, it is difficult to prevent the fin 35 from being raised in the region on the fin rolling end side. Conversely, if the depth D1 of the recess 40 is too large, the fins 35 will be too low at the corresponding portions, which will affect the heat exchange performance. Further, the width W1 of the concave portion 40 is preferably 3% or more of the width of the plate material T. If it is too small, the effect of preventing the fin 35 from becoming high in the region on the fin rolling end side decreases. The width W1 of the concave portion 40 is equal to the width of the split roll 2.
It may be made equal to the width of one step. In this case, the outer peripheral surface of each split roll is inclined over the entire surface.

In this embodiment, the fin rolls 4 form fins 35, grooves, and flat portions 36 as shown in FIG. In this rolling process, the material pressed down to form the groove flows along the fin rolling groove 34 from the fin rolling start side to the fin rolling end side. A concave portion 40 is formed on the fin rolling end portion of the surface, and the processing amount is reduced by that amount, so that the material flow is absorbed in these portions, and excess metal material may enter the depth of the fin rolling groove 34. Can be prevented. Therefore, the fins 3 are formed in the area corresponding to the recess 40.
The height of 5 does not become too large.

At the position corresponding to the concave portion 40 of the fin roll 4, a slight convex portion 42 may be formed on the surface of the plate material T as shown in FIG. The thickness is desirably 75% or less of the thickness of the strip material T before rolling. This is because if it is too large, this part becomes hard and roll forming becomes difficult.

Other configurations may be the same as in the second embodiment. According to the third embodiment, when the fin 35 and the groove are rolled by the fin rolling roll 4, the material pressed down to form the groove moves from the fin rolling start side to the fin rolling end side. Even if it flows along the fin rolling groove 34, the material flow can be absorbed by the concave portion 40 formed on the fin rolling end side portion of the outer peripheral surface of the fin rolling roll 4, and It is possible to prevent excess metal material from invading. Therefore, the height of the fin 35 does not become excessively high in the region corresponding to the concave portion 40, and interference between the fin 35 and the edge of the fin rolling groove 34 can be prevented, and damage to the edge is suppressed. Therefore, the use of the fin roll 4 is synergistic with the fact that the WC-Ni cemented carbide is used as the material of the split rolls 4A to 4D and that the split rolls 4A to 4D are diffusion bonded. It is possible to extend the life even further.

[Fourth Embodiment] FIG. 11 shows a fin roll 4 and a receiving roll 6 according to a fourth embodiment of the present invention. The other parts are the same as those of the above-described embodiments, and the description is omitted.

In this embodiment, instead of forming the concave portion 40 in the fin roll 4, the outer peripheral surface of the receiving roll 6 is provided with the mating surface of the split roll 4 A and the split roll 4 B and the split roll 4 C and the split roll 4 C. Two recesses 44 are formed over the entire circumference at positions facing the mating surface with the roll 4D, respectively. The width and the depth of the concave portion 44 are set similarly to the concave portion 40 of the second embodiment.

According to such an embodiment, when the fins 35 are rolled by the fin rolling rolls 4, the sheet material T
Of the recess 4 is elastically deformed into the recess 44 and escapes.
The amount of processing in the portion facing 4 is relatively reduced. Therefore, even if the material pressed down at the time of forming the groove flows from the fin rolling start side to the fin rolling end side, the material flow can be absorbed by the concave portion 44, and the fins 35 become excessive in these regions. Is prevented from rising to
As shown in FIG. 2, it is possible to roll the fins 35 having a substantially uniform height. Therefore, interference between the fin 35 and the edge of the fin rolling groove 34 is reduced, and damage to the edge due to the interference can be prevented. Therefore, the WC-Ni-based cemented carbide is used as the material of the split rolls 4A to 4D; ,
The service life of the fin roll 4 can be further extended in synergy with the fact that the division rolls 4A to 4D are diffusion-bonded.

[Fifth Embodiment] Next, FIG. 13 and FIG.
Reference numeral 4 denotes a main part of the fifth embodiment of the present invention. In this embodiment, the fin rolling roll 4 or the receiving roll 6
Instead of changing the shape of the fin rolling step, that is, a thickness adjusting mechanism of the plate material T shown in FIG. 13 is provided between the pressing roll 2 and the fin rolling roll 4 in FIG. It is characterized in that the thickness of the strip material T is adjusted before fin rolling.

The thickness adjusting mechanism of this embodiment includes a grooving roll 46 and a receiving roll 52 which are arranged to face each other. The outer peripheral surface of the receiving roll 52 is flat,
On the outer peripheral surface of the grooving roll 46, gently protruding ridges 48 are formed at positions corresponding to the mating surfaces of the split rolls 4A and 4B and the mating surfaces of the split rolls 4C and 4D. ing. These ridges 48
Is not limited, but may be set to be the same as the width W1 and the depth D1 of the recess 40 in the third embodiment.

In this embodiment, as shown in FIG. 1, the strip material T is continuously fed from the uncoiler 1, and the fed strip material T is received by the grooved roll 46 via the pair of pressing rolls 2. It passes between rolls 52 (not shown in FIG. 1). Then, a pair of shallow concave grooves 50 are formed on the surface of the plate member T by being pressed down by the protrusions 48.

Next, the sheet material T having the concave groove 50 formed on the surface thereof is transferred to the fin roll 4 and the receiving roll 6 shown in FIG.
And the W-shaped fin 3
5 is formed. At this time, near the fin rolling end point,
Since the groove 50 is previously formed in the strip material T and the processing amount in the portion facing the groove 50 is relatively reduced, the material pressed down by the fin rolling roll 4 starts fin rolling. Material flow can be absorbed by the concave groove 50, the fins 35 are prevented from becoming excessively high in these regions, and the fins 35 having a substantially uniform height can be formed. Rolling becomes possible. Therefore, the interference between the fin 35 and the edge of the fin rolling groove 34 is reduced, the edge is prevented from being damaged by the interference, and the WC-Ni cemented carbide is used as the material of the split rolls 4A to 4D. The service life of the fin roll 4 can be further extended in synergy with the fact that 4A to 4D are diffusion-bonded.

Although a plurality of embodiments have been described above, the present invention is not limited to only the above-described embodiments. For example, the uneven structure formed on the outer peripheral surface of the roll body 32 is not a spiral groove, but a large number. Independent dimples, or grooves extending in the roll axis direction or the circumferential direction.

The features of each embodiment may be combined as appropriate. For example, the concave portion 40 may be formed on the fin roll 4 as shown in FIG. 9 and the concave portion 44 may be formed on the receiving roll 6 as shown in FIG. Mechanisms may be combined. Also,
The side roll 30 may be integrally diffusion bonded with the roll body 32 if necessary.

[0055]

EXAMPLES Next, the effects will be demonstrated with reference to examples of the present invention. Rolled fin rolls using a conventional WC-Co based cemented carbide (conventional example), fin rolls having too much nickel content even with a WC-Ni based cemented carbide (comparative example),
And fin rolls using three types of fin rolls (examples) using a WC-Ni-based cemented carbide within the composition range of the present invention.
The comparison was made based on the total weight (ton) of the rolled sheet material. The composition of each alloy is as follows.

Conventional example: WC-15 wt% Co, average particle size of WC: 2 μm Comparative example: WC-32.0 wt% Ni, average particle size of WC:
Less than 2 μm, trace element (total 1 wt% or less): Cr, C
o, Al Example: WC-18.7 wt% Ni, average particle size of WC:
Less than 1 μm, trace elements (total 1 wt% or less): Cr, Co

The common dimensions of the fin rolls are as follows. Roll outer diameter: 150 mm Sheet material width: 26 mm Fin roll groove shape: W type Lead angle between fin roll groove and roll circumferential direction: 14 ゜ Fin height: 0.20 mm Rolling conditions are any Is also as follows. Rolling speed: 150 m / min. Table 1 shows the result of using soluble oil during rolling.

[0058]

[Table 1]

[0059]

As described above, according to the roll for roll forming according to the present invention, nickel is used as a binder component instead of cobalt, which has good affinity for copper, and therefore contains copper. Even when the material is rolled, it is possible to prevent copper from forming a solid solution in the binder phase on the roll surface and promoting elution of the binder phase into the lubricating liquid. Therefore, it is possible to suppress a decrease in the strength of the cemented carbide due to the elution of the binder phase from the roll surface, reduce the frequency of occurrence of chipping of the concavo-convex structure, and extend the roll life.

According to the apparatus for manufacturing a heat transfer tube with an inner groove according to the present invention, nickel is used as a binder phase component of a roll for forming work instead of cobalt having a good affinity for copper. Also, when the sheet material containing copper is rolled, the phenomenon that copper is dissolved in the binder phase on the roll surface and the binder phase is eluted into the lubricating liquid is reduced. Therefore, it is possible to suppress a decrease in strength due to the elution of the binding phase from the roll surface, reduce the frequency of occurrence of chipping of the roll for rolling, and reduce the occurrence of fin shape abnormality due to chipping of the roll.

The roll body is composed of a plurality of divided rolls,
When these are diffusion-bonded to each other, even the end faces of the respective groove partition walls butted at the bent portions of the fin rolling grooves are integrally connected, so that the ends of the groove partition walls butted by the bent portions are connected. Hard to break, roll body is WC-Ni
In combination with the effect formed by the cemented carbide, the life of the fin roll can be extended.

On both sides of the fin roll, side rolls having a smooth surface are arranged coaxially, and these side rolls can be replaced with other side rolls having different outer diameters. Can easily respond to changes.

When the outer diameter of the fin rolling roll and / or the receiving roll is relatively reduced at the position at the end of the material flow, the fins are excessively high due to the bias of the material. Phenomenon can be prevented. Therefore, the interference between the fin and the edge of the fin rolling groove is reduced, and the edge is prevented from being damaged by the interference.
It is possible to further extend the service life of the fin roll roll by synergistic with the effect formed by the Ni-based cemented carbide and the effect of diffusion bonding of the split rolls to each other.

Further, a thickness adjusting mechanism for rolling the sheet material and partially adjusting the thickness thereof is provided at a stage preceding the fin rolling roll, and the sheet material is positioned at the end of the material flow. When the thickness is reduced, it is possible to prevent a phenomenon that the fins become excessively high due to the bias of the material. Therefore, the interference between the fin and the edge of the fin rolling groove is reduced, and the edge is prevented from being damaged by the interference.
It is possible to further extend the service life of the fin roll roll by synergistic with the effect formed by the Ni-based cemented carbide and the effect of diffusion bonding of the split rolls to each other.

[Brief description of the drawings]

FIG. 1 is a side view showing a first embodiment of an apparatus for manufacturing a heat transfer tube with an inner surface groove according to the present invention.

FIG. 2 is a front view showing the vicinity of a fin roll of the manufacturing apparatus.

FIG. 3 is a sectional view of a fin roll of the manufacturing apparatus.

FIG. 4 is a plan view showing a fin rolling step of the manufacturing apparatus.

FIG. 5 is a plan view illustrating a fin rolling process according to a second embodiment.

FIG. 6 is a front view showing the vicinity of a fin rolling roll according to a second embodiment.

FIG. 7 is a cross-sectional view of a fin rolling roll according to a second embodiment.

FIG. 8 is a partially developed plan view of an internally grooved heat transfer tube manufactured by the second embodiment.

FIG. 9 is a front view showing the vicinity of a fin roll of a third embodiment.

FIG. 10 is a cross-sectional view showing a strip material rolled by a fin rolling roll according to a third embodiment.

FIG. 11 is a front view showing the vicinity of a fin roll of a fourth embodiment.

FIG. 12 is a cross-sectional view showing a strip material rolled by a fin rolling roll according to a fourth embodiment.

FIG. 13 is a front view showing a plate member thickness adjusting mechanism according to a fifth embodiment.

FIG. 14 is a front view showing the vicinity of a fin roll of a fifth embodiment.

[Explanation of symbols]

 Reference Signs List 1 Uncoiler 3 Lubricating liquid nozzle (lubricating liquid supply mechanism) 4 Fin roll (rolling roll) 6 Receiving roll T Plate strip 10 Forming roll 14 Induction heating coil 30 Side roll 32 Roll body 34 Fin rolling groove ( Concavo-convex structure) 4A to 4D Dividing roll 35 Fin 40, 44 Concavity 46 Grooving roll (thickness adjusting mechanism) 52 Receiving roll (thickness adjusting mechanism) 48 Protrusion

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shin Kikuchi 128-7 Ogimachi, Aizuwakamatsu-shi, Fukushima Prefecture Wakamatsu Manufacturing Co., Ltd. (72) Inventor Takao Fukamin 128-7 Ogimachi, Aizuwakamatsu-shi, Fukushima Prefecture Shin Shin Mitsubishi Copper Wakamatsu Works (72) Inventor Kotaro Nagahara 128-7 Ogimachi, Aizuwakamatsu-shi, Fukushima Prefecture Mitsubishi Shindoh Wakamatsu Works F-term (reference) 4E063 AA01 BB06 EA01 KA04 KA15 MA17

Claims (8)

[Claims] 1. A roll body having an uneven surface for rolling formed on an outer peripheral surface thereof, the roll body comprising tungsten carbide (WC) as hard dispersed particles and WC containing Ni as a binder phase. -Formed of a Ni-based cemented carbide, the average particle size of WC in the WC-Ni-based cemented carbide is 0.5 to 2 μm, and the content of Ni is 10 to 30 wt.
%, And the content of Co is 2 wt% or less. 2. The roll body according to claim 1, wherein the roll body is formed by a plurality of divided rolls having rolling grooves formed on an outer peripheral surface thereof and arranged coaxially with each other, and these divided rolls are diffusion bonded to each other. Item 7. The roll for rolling according to Item 1. 3. A fin roll and a receiving roll for rolling a fin on one surface of the plate by rolling a metal plate between them, and the fin roll and the plate. A lubricating liquid supply mechanism for supplying a lubricating liquid to a contact point, and a plurality of forming rolls for forming a plate member on which the fins are formed into a tubular shape so that the fins are located on the inner peripheral side. A welding mechanism for heating and butt-welding both end edges of the plate material formed into a tubular shape; the fin roll includes a roll body; and the roll body includes hard dispersed particles. Containing tungsten carbide (WC) as binder and Ni as binder phase
-Formed of a Ni-based cemented carbide, the average particle size of WC in the WC-Ni-based cemented carbide is 0.5 to 2 µm, the content of Ni is 10 to 30 wt%, and the content of Co is Is 2w
An apparatus for manufacturing a heat transfer tube with an inner surface groove, wherein the heat transfer tube is not more than t%. 4. The roll body is constituted by a plurality of divided rolls having fin rolling grooves formed on the outer peripheral surface and arranged coaxially with each other, and these divided rolls are diffusion-bonded to each other. The apparatus for manufacturing a heat transfer tube with an inner surface groove according to claim 3. 5. The heat transfer tube according to claim 4, wherein the lead angles of the fin rolling grooves formed on each of the divided rolls are different between adjacent divided rolls. manufacturing device. 6. Side rolls having a smooth surface are arranged coaxially on both sides of the fin roll, and these side rolls are interchangeable with other side rolls having different outer diameters. The apparatus for manufacturing a heat transfer tube with an inner surface groove according to any one of claims 3 to 5. 7. The outer diameter of the fin rolling roll and / or the receiving roll is such that the outer diameter of the fin rolling roll is opposite to the region where individual fins are finally formed on the strip with the rotation of the fin rolling roll. The apparatus for manufacturing a heat transfer tube with an inner surface groove according to any one of claims 3 to 6, wherein the diameter is relatively reduced in a region in the vicinity of the joint surface. 8. A thickness adjusting mechanism for rolling the plate material and partially adjusting the thickness thereof before the fin rolling roll, the thickness adjusting mechanism comprising: The roll has a function of relatively reducing the thickness of the sheet material in a region near the diffusion bonding surface where individual fins are finally formed on the sheet material. 7. The apparatus for manufacturing a heat transfer tube with an inner surface groove according to any one of 6.