JPH116695A - Grooved streak for heat transfer pipe, and roll for molding the streak - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a grooved streak for a heat transfer pipe in which the contour is easily close to be truly circular by rounding butted parts in the width direction so that a large number of longitudinally inclined grooves are provided in one surface and the surface is the inner side to manufacture a heat transfer pipe, and pressing an expansion plug into the heat transfer pipe for expansion. SOLUTION: A grooved streak 1 for a heat transfer pipe is provided with a plurality of strip-like inner tubular side forming areas la-In parallel to each other along the longitudinal direction on one surface, a large number of parallel grooves 11 which are inclined in the longitudinal direction are formed in at least a part of the inner tubular surface forming areas, and the difference in the total wall thickness on each side part in the width direction in a part of inner tubular surface forming areas (the wall thickness from a fin top part between the grooves formed on the surface to the other surface) is <=0.1 mm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a groove for a heat transfer tube when manufacturing an inner grooved tube by welding, and to a forming roll for forming such a groove for a heat transfer tube. .

[0002]

2. Description of the Related Art Internally grooved tubes are mainly used for heat exchangers of air conditioners and the like. As a method for manufacturing an inner grooved tube, for example, a metal tube is pulled out in a certain direction, a grooved plug is rotatably inserted into the metal tube, and the outer periphery of an insertion portion of the grooved plug of the metal tube is rolled with a rolling tool. There is a so-called rolling method in which the spiral groove on the surface of the plug is transferred to the inner surface of the metal tube by pressing the plug. However, in this manufacturing method, there is a limit in changing a specific factor of the groove shape such as the number of grooves, a twist angle of the groove, and a groove depth, and accordingly, there is also a limit in improving the heat transfer performance.

For this reason, for example, Japanese Patent Application Laid-Open No. 4-158193
As disclosed in Japanese Patent Application Laid-Open Publication No. H10-209, a method is employed in which a plurality of grooves of different types are formed on one side of a metal strip, and the metal strip is rolled into a tube and welded so that the groove is on the inside. JP-A-4-
According to the method described in JP-A-158193, FIG.
As shown in the figure, the metal strip 50 is sandwiched between the groove forming roll 4 and the pressure roll 3 having a smooth peripheral surface while the metal strip 50 having a constant width is fed out by an uncoiler (not shown). While rotating in the direction, the groove 51 is machined on one surface of the metal strip 50 to produce the grooved strip 5. Then
The grooved strips 5 are formed into grooves 5 by a forming roll group (not shown).
The heat transfer tube of a predetermined size is manufactured by rounding along the width direction so that 1 is on the inside, forming a tube, welding the butted portions on both sides sequentially, and further passing through a finishing die to empty the tube.

The forming roll 4 is composed of roll pieces 4a to 4d having a substantially constant length attached to the same shaft 40, and adjacent roll pieces 4a and 4b and 4c and 4c.
In d, a plurality of parallel grooves 41 are formed, each of which has an inverted lead angle with respect to the axis 40. Therefore, one surface of the grooved strip 5 is divided into tube inner surface forming regions 5a to 5d having a predetermined width along the length direction corresponding to the roll pieces 4a to 4d of the forming roll 4, and each of the regions 5a to 5d.
5d has a number of parallel grooves 51 inclined in opposite directions.
Are formed on the inner surface of the heat transfer tube manufactured as described above, and a large number of parallel grooves are formed in each of the regions 5a to 5d by reversing the leads with respect to the tube axis. The coexistence of several different types of grooves can disrupt the flow of the refrigerant in the tube and enhance the heat transfer performance in the tube.

When a cross-fin type heat exchanger is manufactured using the heat transfer tube manufactured as described above, a hole 70 is formed in advance for inserting the heat transfer tube 6 as shown in FIG. For example, many fins 7 made of aluminum alloy
Are arranged so as to overlap with each other at a predetermined pitch along the length direction of the heat transfer tube 6, the heat transfer tube 6 is inserted into the hole 70 of each of the fins 7, and the expansion plug 60 is pushed into the heat transfer tube 6. The heat pipe 6 is expanded so as to be in close contact with the hole 70 of the fin 7.

[0006]

The heat transfer tube disclosed in the above publication is
Although the heat transfer performance in the pipe is improved, when the grooved strip 5 is manufactured by processing the groove 51 in the metal strip 50 as shown in FIG. 18, there are the following problems. In FIG. 18, each end a to e of each of the roll pieces 4 a to 4 d corresponds to each of the regions 5 a to 5 of the grooved strip 5.
d corresponds to each side A to E, but the metal strip 50 has a groove 5
1 is formed, the metal material is deflected in the direction of the arrow in the figure, that is, from the sides A, C, and E of the regions 5a to 5d of the grooved strip 5 to the directions of the other sides B and D. It becomes thicker as it approaches the sides B and D.

For example, when a metal strip made of deoxidized copper having a width of 30 mm and a plate thickness of 0.5 mm is used, and a groove is formed on the metal strip to produce a grooved strip 5, as shown in FIGS. The groove depth h at the side portions B and D of each of the regions 5a to 5d of the strip 5 is considerably deeper than the groove depth h at the other side portions A, C and E. Therefore, even though the groove bottom thickness t of each of the regions 5a to 5d is substantially equal in each portion in the width direction, the total thickness T is considerably larger at the side portions B and D than at the side portions A, C and E. growing. This is because each of the roll pieces 4a to 4d in FIG.
When the roll 41 rotates, the ends of the grooves 41 of the roll pieces 4 a to 4 d contact the metal strip 50 first at the ends of the a, c, and e sides. This is because the position of contact with the ridge 50 shifts to the b and d sides, so that the material becomes uneven and accumulates in the groove 41 as it approaches the ends b and d.

When the heat transfer tube 6 obtained by forming the grooved strip 5 into a tubular shape and welding as described above is passed through the hole 70 of the fin 7 as shown in FIG. As shown by 22, since the depth of the groove 51 at the portions A, C, and E in the heat transfer tube 6 is smaller than the depth of the groove 51 at the portions B and D, the outer shape is expanded to an elliptical shape. . Therefore, a gap 71 is formed between the hole 70 of the fin 7 and the outer peripheral surface of the heat transfer tube 6, and the adhesion is reduced. As described above, when the gap 71 is formed between the heat transfer tube 6 and the hole 70 of the fin 7,
In addition to the heat transfer performance of the heat exchanger being reduced, moisture easily accumulates in the gap 71 when the heat exchanger is used, so that the heat exchanger is easily corroded. On the other hand, if the expansion rate of the heat transfer tube 6 is increased to close the gap 71, the groove 51 in the heat transfer tube 6 is crushed, and the heat transfer performance in the tube is reduced.

[0009] The disadvantages shown in FIGS.
8, adjacent regions 5a, 5 of the processed grooved strip 5
The grooves 51 in b and 5c, 5d typically appear when the inclination with respect to the longitudinal direction is reversed. However, for example, the grooves 51 in the regions 5a and 5c are inclined in the length direction, and no grooves are formed in the regions 5b and 5d adjacent to them, or the grooves formed in the regions 5b and 5d are grooves. Even in the case of extending along the width direction of the attachment 5 or along the length direction of the attachment 5, the above-described tendency of the above-described inconvenience appears, although the degree is different.

An object of the present invention is to provide a plurality of strip-shaped tube inner surface forming regions which are parallel to each other along the length direction on one surface, and to at least a part of the tube inner surface forming regions, a large number of tubes inclined with respect to the length direction. In the groove with parallel grooves formed, the heat transfer tube is manufactured by rolling in the width direction so that the one surface is on the inside and welding the butted portions on both sides, and a pipe expansion plug is pushed into the heat transfer tube to expand the tube. In this case, an object of the present invention is to provide a groove for a heat transfer tube whose outer shape is more likely to be a perfect circle. Another object of the present invention is to provide a grooved strip forming roll suitable for manufacturing a grooved strip for a heat transfer tube that can solve the above-mentioned problems.

[0011]

SUMMARY OF THE INVENTION A groove for a heat transfer tube according to the present invention has the following structure to solve the above-mentioned problems. That is, the groove with a heat transfer tube according to claim 1 has a plurality of strip-shaped tube inner surface forming regions 1a to 1n parallel to each other along the length direction on one surface, and at least a part of the tube inner surface forming regions. Is formed with a number of parallel grooves 11 inclined with respect to the length direction, and the total thickness of both side portions in the width direction in the partial tube inner surface forming region (the fin top portion between the grooves formed on the one surface and 0.1mm difference in thickness to the other side)
It is characterized as follows.

According to a second aspect of the present invention, in the heat transfer tube groove according to the first aspect, the other part of the tube inner surface formation region is formed in the other part of the tube inner surface formation region. A number of parallel grooves 11 inclined in the opposite direction to the grooves 11 formed in the region are formed, and the difference in the total thickness of both side portions in the width direction of the other part of the tube inner surface forming region is 0.1 mm. It is characterized as follows.

The grooved roll for heat transfer tubes according to the present invention is configured as follows to solve the above-mentioned problems. That is, the grooved roll for heat-transfer tubes according to claim 3 has a groove 11 on one surface of the metal strip 10 while rotating with the metal strip 10 sandwiched between the pressure roll 3 and the smooth roll. In the groove forming roll for heat transfer tubes for forming the heat transfer tube, the groove forming roll for heat transfer tubes 2 includes a plurality of roll pieces 2a to 2n having a predetermined length fixed to the coaxial 20; A plurality of parallel grooves 21 having a predetermined lead angle with respect to the axis 20 are formed on the peripheral surface of the roll piece. Is characterized in that the diameter of the end on the side where one end thereof comes into contact with the metal strip 10 last is smaller than the diameter of the other end.

The grooved roll for heat transfer tubes according to claim 4 is the same as the grooved roll for heat transfer tubes according to claim 3, except that a shaft 20 is formed on the peripheral surface of another part of the roll pieces. A plurality of parallel grooves 21 having a lead angle opposite to that of the grooves 21 formed in some of the roll pieces are formed, and the other one of the roll pieces is rotated once. In this case, one end of 21 formed on the roll piece is formed such that the diameter of the end on the side that comes into contact with the metal strip 10 at the end is smaller than the diameter of the other end. I have.

According to a fifth aspect of the present invention, there is provided a grooved roll for heat transfer tubes according to the third or fourth aspect, wherein both ends of the roll piece in which the groove 21 is formed are provided. Is characterized in that the difference in outer diameter is 0.5 mm or less.

In the grooved forming roll for heat transfer tubes according to the present invention, the outer shape of the roll piece in which the groove 21 is formed is (a) a maximum outer diameter portion (when the roll piece makes one rotation, One in which one end of the groove 21 is conically tapered in the direction from the last end on the side in contact with the metal strip 10) to the minimum outer diameter portion (the other end of the roll piece); ) Includes those that decrease in the shape of an arc from the maximum outer diameter portion to the minimum outer diameter portion, and (c) those that decrease stepwise in the direction from the maximum outer diameter portion to the minimum outer diameter portion.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a groove for forming a heat transfer tube and a groove forming roll according to the present invention will be described with reference to FIGS. First Embodiment FIGS. 1 to 3 show a heat transfer tube grooved roll according to a first embodiment of the present invention. FIG. 1 is a partial plan view of a grooved forming roll for a heat transfer tube of the first embodiment and a grooved line being processed, FIG. 2 is a half sectional view of a similar forming roll, and FIG. 3 is a forming roll and a pressure roll. FIG. 4 is a partial perspective view showing a state in which a groove is processed.

The forming roll 2 is made of cemented carbide, and the shaft 2
Roll pieces 2a, 2b, 2c,
2d. Roll pieces 2a, 2
A number of grooves 21 having a predetermined lead angle θ1 with respect to the axis 20 are formed in parallel on the peripheral surface of the roll c, and a predetermined lead angle with respect to the axis 20 is formed on the peripheral surfaces of the other roll pieces 2b and 2d. θ
A number of grooves 21 having two are formed. A groove 21 formed in the roll pieces 2a and 2c;
The grooves 21 formed in b and 2d have the same inclination but opposite angles.

The outer periphery of each of the roll pieces 2a to 2d is such that the positions of their ends a, c, and e are the maximum outer diameter portions D1.
The end portions b and d are cut in a conical taper shape so that the positions of the ends b and d are the minimum outer diameter portions D2. Each roll piece 2a ~
The maximum outer diameter portion D1 of 2d is φ100 mm, and the minimum outer diameter portion D2 is φ99.9 mm. As shown in FIG. 2, the level (distance from the center of the shaft 20) of the groove 21 of each of the roll pieces 2a to 2d is constant, and the depth H of the groove 21 is constant.
Is designed to be 0.4 mm at the maximum outer diameter portion D1, and each groove 21 is gradually shallower from the maximum outer diameter portion D1 toward the minimum outer diameter portion D2.

Example 1 As shown in FIG. 3, a molding roll 2 of the first embodiment and a pressure roll (outer diameter φ100 mm) 3 having a smooth peripheral surface were used, A metal strip 10 made of deoxidized copper having a width of 0.5 mm and a width of 30 mm is sandwiched, and the pressing amount is adjusted so that the depth h of the groove 11 formed at the portion of the maximum outer diameter portion D1 becomes 0.2 mm. A grooved strip 1 for a heat transfer tube having a large number of parallel grooves 11 to which the grooves 21 of the roll pieces 2a to 2d are respectively transferred is formed in each of the pipe inner surface forming regions 1a to 1d which are parallel to the strip along the width direction. processed. On the other hand, the same material as that of the forming roll 2 is used, and each of the roll pieces 4a to 4d having an outer diameter φ of 100 mm is formed in the respective roll pieces 4a to 4d.
A conventional forming roll 4 as shown in FIG. 19 having grooves 41 having a lead angle similar to that of FIG. The forming roll 4 and the pressing roll 3 sandwich the metal strip 50 of the same material and size as in the above-described embodiment, and the depth of the groove 51 formed by each of the portions b and d of the forming roll 4 is zero. 2 mm, the grooves 4 of the roll pieces 4a to 4d are formed in the respective tube inner surface forming regions 4a to 4a parallel to each other in a strip shape along the length direction.
A grooved strip 5 having a large number of parallel grooves 51 to which each 1 was transferred was machined.

Regarding the grooved strip 1 according to the embodiment and the grooved strip 5 according to the conventional example, both ends A, B, C, D,
E and the total thickness T at the center thereof (T = t (groove bottom thickness) + h (groove depth) in FIG. 4) were measured, and were as shown in FIG. In FIG. 5, the measurement result of the conventional grooved strip is indicated by a solid line, and the measurement result of the grooved strip of the embodiment is indicated by a dotted line. According to the measurement result, both ends of each pipe inner surface forming region are shown. The difference of the total thickness T in the portion is slightly more than 0.11 mm in the conventional grooved strip,
It was 0.02 mm in the groove with a groove of the example.

A large number of the grooved strips 1 of the first embodiment are manufactured, formed into a tubular shape by a conventional method using a forming device (not shown), and the butted portions on both sides thereof are welded. Vacuum with a die and outer diameter φ9.
A 53 mm heat transfer tube was manufactured. Using these heat transfer tubes, a cross-fin type heat exchanger was manufactured in the manner described with reference to FIG. 21. However, since each heat transfer tube has a small difference in the total wall thickness at each portion, the heat transfer tubes were expanded almost in a perfect circle. Thus, no gap was formed between the hole 70 of the fin 7 and the outer peripheral surface of the heat transfer tube.

Second Embodiment FIG. 6 shows a heat transfer tube grooved roll according to a second embodiment of the present invention. This figure is a half plan view of the forming roll on the feeding side of the grooved strip.
Each of the roll pieces 2a to 2d has a large number of parallel grooves 2 substantially similar to those in the forming roll of the first embodiment.
1 is formed. The material and size of each of the roll pieces 2a to 2d are substantially the same as those of the first embodiment, but their peripheral surfaces are reduced in an arc shape from the maximum outer diameter portion D1 toward the minimum outer diameter portion D2. Is formed.

Example 2 As shown in FIG. 3, the grooved strip 1 was processed under the same conditions as in Example 1 using the forming roll 2 of the second embodiment and the pressure roll 3 having a smooth peripheral surface. , Each tube inner surface forming region 1a to
1d and the total thickness T at the center of each side.
Was measured, and the result shown by the dotted line in FIG. 7 was obtained. FIG. 7 also shows the measurement results of the conventional example shown in FIG. 5 by a solid line for comparison. According to the measurement results, the difference in the total thickness T in each portion of each of the regions 1a to 1d of the grooved strip 1 was less than 0.03 mm. The outer diameter φ is obtained by the grooved strip 1 processed by using the forming roll 2 of FIG.
When a 9.53 mm welded heat transfer tube was manufactured and expanded in the manner described with reference to FIG. 21, the tube could be expanded to a shape close to a perfect circle, and between the hole 70 of the fin 7 and the peripheral surface of the heat transfer tube. No gap was formed.

Third Embodiment FIG. 8 shows a heat transfer tube grooved roll according to a third embodiment of the present invention. This figure is a half plan view of the forming roll on the feeding side of the grooved strip.
Each of the roll pieces 2a to 2d has a large number of parallel grooves 2 substantially similar to those in the forming roll of the first embodiment.
1 is formed. The material and size of each of the roll pieces 2a to 2d are substantially the same as those of the first embodiment, but their peripheral surfaces are stepwise (stepped) from the maximum outer diameter portion D1 toward the minimum outer diameter portion D2. )).

Example 3 As shown in FIG. 3, a grooved strip 1 was processed under the same conditions as in Example 1 by using the forming roll 2 of the third embodiment and a pressure roll 3 having a smooth peripheral surface. , Each tube inner surface forming region 1a to
1d and the total thickness T at the center of each side.
Was measured, and the result shown by the dotted line in FIG. 9 was obtained. FIG. 9 also shows the measurement results of the conventional example shown in FIG. 5 by a solid line for comparison. According to the above measurement results, the difference in the total thickness T in each portion of each of the regions 1a to 1d of the grooved strip 1 was about 0.02 mm. The outer diameter φ is obtained by the grooved strip 1 processed by using the forming roll 2 in FIG.
When a 9.53 mm welded heat transfer tube was manufactured and expanded in the manner described with reference to FIG. 21, the tube could be expanded to a shape close to a perfect circle, and between the hole 70 of the fin 7 and the peripheral surface of the heat transfer tube. No gap was formed.

Example 4 In manufacturing the grooved strip 1 having the same groove forming pattern as in Example 1, the difference between the maximum outer diameter portion D1 and the minimum outer diameter portion D2 of the grooved strip forming roll 2 was changed within a predetermined range. Case No. 1-9
(However, No. 1 is a conventional example having an outer diameter difference of 0) Forming roll 2
Are manufactured, and each forming roll and the pressing roll 3 of FIG.
And a grooved strip processing experiment was performed under the same conditions as in Example 1 to measure the difference in the total thickness of each grooved strip in each part in the width direction. The results are shown in Table 1.

[0028]

[Table 1]

As is clear from the results in Table 1, No. 1 which is a conventional example. The grooved groove processed using the forming roll 1 has a difference in total thickness in the width direction of 0.11 mm,
In the embodiment according to the present invention, No. 2-No. Each of the grooved strips processed using the forming rolls No. 9 had a total thickness difference in the width direction of 0.1 mm or less.

Next, the above-mentioned No. 1 to No. Pipe-forming welding using the grooved strip processed by the forming roll of No. 9,
These are passed through a finishing die and evacuated to an outer diameter of φ9.
Each 53 mm heat transfer tube was manufactured. For each of these heat transfer tubes, a tube expansion experiment was performed as shown in FIG. 21 to check the adhesion of the fins 7 to the holes 70. As a result, the difference in total thickness in the width direction of the grooved strip exceeded 0.1 mm. In the heat transfer tube using the conventional grooved strip of No. 1 described above, a gap was formed between the heat transfer tube and the hole 70 of the fin 7 and the adhesion was not good. N of the embodiment of the present invention which is 1 mm or less
o. In the heat transfer tube using the grooves 2 to 9, no gap was formed between the heat transfer tube and the hole 70 of the fin 7, and the adhesion between the two was good.

FIG. FIG. 11 shows the processing state of the grooved strip 1 (region 1c) by the forming roll 2 (roll piece 2c) of No. 3 in FIG. The processing state of the grooved strip 1 (region 1c) by the forming roll 2 (roll piece 2c) of No. 9 is shown in an enlarged manner. FIG. 1 in which the maximum outer diameter D1-the minimum outer diameter D2 of the forming roll 2 is 0.05 mm.
In the forming roll 2 of No. 0, the grooves 11 are formed uniformly in the width direction of the region 1c of the grooved strip 1. In contrast,
Maximum outer diameter portion D1-minimum outer diameter portion D2 of forming roll 2 = 0.
In the forming roll 2 of FIG. 11 which is 60 mm, in the width direction of the region 1c of the grooved strip 1, the minimum outer diameter portion D of the roll 2
The groove 11 is scarcely formed in the portion where 2 contacts. As described above, when a portion without the groove 11 according to the design is formed in the grooved strip 1, the heat transfer performance in the pipe is reduced. From the state of FIG. 10 and FIG. 9 as shown in FIG.
It is clear that when the forming roll 2 having a large difference between the diameter and the minimum outer diameter portion D2 is used, it is necessary to increase the amount of pressure in order to make the groove 11 of the grooved strip 1 sufficient. However, an increase in the amount of pressurization causes breakage of the forming roll, shortens the life of the tool, and consequently reduces the productivity. Therefore, the difference between the maximum outer diameter portion and the minimum outer diameter portion of the forming roll 2 (both ends of the roll piece). It is preferable that the difference between the outer diameters is 0.5 mm or less. The limitation in claim 5 shows this preferred case.

Example 5 A forming roll 2 is formed by two roll pieces 2a and 2b as shown in FIG. 12 (h), by four roll pieces 2a to 2d as shown in FIG. (I) As shown in the drawing, grooves 21 formed of six roll pieces 2a to 2f are formed in adjacent roll pieces, and grooves 21 formed between adjacent roll pieces are inclined in opposite directions, and grooves 2 of forming roll 2 shown in FIG.
Each of the forming rolls according to the embodiment of the present invention in which the apex angles α of 1 were 20, 30 and 40 degrees, respectively. Each forming roll has a maximum outer diameter portion of φ100 mm as in Example 1,
The minimum outer diameter portion was φ99.90 mm, and the depth H of the groove 21 was 0.4 mm at the maximum outer diameter portion, similarly to the first embodiment. On the other hand, other forming rolls having the same structure, an outer diameter of 100 mm, no difference in the outer diameter in the length direction, and a groove depth H of 0.4 mm were constant and a conventional structure was manufactured. Using a metal strip made of deoxidized copper having a width of 30 mm and a plate thickness of 0.5 mm, a groove depth at the center of each roll piece is obtained by combining each of the above-mentioned forming rolls with a roll similar to the pressing roll 3 in FIG. Adjust the amount of pressure so that the height h is 0.2 mm,
Each groove was processed. Then, for each groove, when the difference in the total thickness in the width direction was measured,
The results were as shown in Table 2. As is clear from the measurement results in Table 2, when the lengths of the forming rolls are the same, the number of roll pieces, and the grooved groove to be machined in inverse proportion to the size of the angle of the groove apex angle α. Although the total thickness difference in the width direction shows a tendency to be smaller, the grooved groove processed by the conventional forming roll has a total thickness difference in the width direction of more than 0.1 mm, The grooved portions processed by the forming rolls of the examples according to the present invention each have a total thickness difference of 0.1 mm or less in the width direction.

[0033]

[Table 2]

Fourth Embodiment FIG. 14 is a partial plan view showing a grooved strip forming roll and a grooved strip being processed according to a fourth embodiment. The figure is a half plan view of the exit side of the grooved strip 1 in the forming roll 2, and the forming roll 2 is constituted by roll pieces 2a to 2d fixed to the coaxial 20, and the a-side end of the roll piece 2a, A narrow smooth portion is formed at the e-side end of the roll piece 2d. In the roll pieces 2a and 2c, a number of parallel grooves 21 having a lead angle in the same direction with respect to the axis 20 are formed on the peripheral surface, respectively, and the roll pieces 2a and 2c are formed.
The roll pieces 2b and 2d adjacent to the c.
A large number of parallel grooves 21 are respectively formed along the directions. The a-side end of the roll piece 2a and the c-side end of the roll piece 2c are their maximum outer diameters, each having a diameter of 100 mm, and the b-side end of the roll piece 2a and the d-side end of the roll piece 2c. The portions are their minimum outer diameters, each of which is about 0.1 mm smaller than their maximum outer diameter. The outer diameter of the roll pieces 2b and 2d is φ
100 mm, and there is no difference in outer diameter at each part in the length direction. The depth of the groove 21 of the roll pieces 2a, 2c is 0.4 mm at the maximum outer diameter part, and the level of the groove bottom of each groove 21 is configured to be substantially equal. The depth of the groove 21 of the roll pieces 2b, 2d is 0.4 mm.

The grooved strip 1 processed by using the forming roll 2 of the fourth embodiment has a strip-shaped tube inner surface forming area 1a parallel to the length direction corresponding to the roll pieces 2a to 2d.
1d are formed, and the smooth portions 1 are formed on both side edges in the width direction.
h is formed. Tube inner surface forming regions 1a, 1c of grooved strip 1
Are formed with a large number of parallel grooves 11 inclined with respect to the length direction, and the other regions 1b and 1d are formed with a number of parallel grooves 11 along the width direction. The difference in the total thickness in the width direction of the grooved strip 1 is 0.1 mm or less. Therefore, when the heat transfer tube formed by welding with the grooved strip 1 is expanded in the manner shown in FIG. 21, the outer shape is expanded so as to be closer to a perfect circle. Other configurations, operations, and effects of the forming roll and the groove with a groove according to this embodiment are substantially the same as those of the first embodiment, and thus description thereof will be omitted.

Fifth Embodiment FIG. 15 is a partial plan view of a grooved strip forming roll according to a fifth embodiment and a grooved strip being processed. The figure is a half plan view of the exit side of the grooved strip 1 in the forming roll 2.
Is composed of roll pieces 2a to 2d fixed to the coaxial 20 and spacers 2g with smooth peripheral surfaces interposed between the roll pieces 2a and 2b and between the roll pieces 2c and 2d, respectively. Narrow smooth portions are formed at the end and the e-side end of the roll piece 2d, respectively. Roll pieces 2a, 2c and 2b, 2
In d, a large number of parallel grooves 21 having a lead angle in the opposite direction to the axis 20 are formed on the peripheral surface. A side end of roll piece 2a, c of roll pieces 2b, 2c
The side end and the e-side end of the roll piece 2d are their maximum outer diameters, each having a diameter of 100 mm, and the other end of each of the roll pieces 2a to 2d is their minimum outer diameter. 0.1 mm larger than their maximum outer diameter
It is getting cheaper. Groove 21 of roll pieces 2a to 2d
Has a maximum outer diameter of 0.4 mm, and each groove 21
Are configured so that the levels at the inner bottom are substantially equal. The outer diameter of the spacer 2g is substantially equal to the minimum outer diameter of the roll pieces 2a, 2b and 2c, 2d on both sides thereof.

The grooved strip 1 processed by using the forming roll 2 of the fifth embodiment has a strip-shaped tube inner surface forming area 1a parallel to the length direction corresponding to the roll pieces 2a to 2d.
1d are formed, a smooth region 1g is formed in a portion corresponding to each spacer 2g, and a smooth portion 1h is formed in both side edges. A large number of parallel grooves 11 inclined with respect to the length direction are formed in the tube inner surface forming regions 1a to 1d of the grooved strip 1. The difference in the total thickness in the width direction of the grooved strip 1 is 0.1 mm or less. Accordingly, when the heat transfer tube welded by pipe forming by the grooved strip 1 is expanded in the manner shown in FIG. 21, the outer shape is expanded so as to be closer to a perfect circle. Other configurations and actions of the forming roll and grooved strip of this embodiment,
The effects are almost the same as those in the first embodiment, and the description thereof is omitted.

Sixth Embodiment FIG. 16 is a partial plan view of the grooved strip forming roll of the sixth embodiment and the grooved strip being processed. The figure is a half plan view of the exit side of the grooved strip 1 in the forming roll 2.
Is constituted by roll pieces 2 a to 2 f fixed to the coaxial 20. In the roll pieces 2a, 2c and 2e, a large number of parallel grooves 21 having a predetermined lead angle with respect to the axis 20 are formed on the peripheral surface, respectively. The grooves 21 of the roll pieces 2a and 2e and the The groove 21 is
The lead angle with respect to the shaft 20 is reversed. The peripheral surfaces of the roll pieces 2b, 2d, 2f are smooth. The a-side end of the roll piece 2a, the d-side end of the roll piece 2c, and the e-side end of the roll piece 2e are their maximum outer diameters, each having a diameter of 100 mm.
The other ends of 2c and 2e are their minimum outer diameters, and both are about 0.1 mm smaller than their maximum outer diameters. Groove 21 of roll pieces 2a, 2c, 2e
Has a maximum outer diameter of 0.4 mm, and each groove 21
Are configured so that the levels at the inner bottom are substantially equal. The outer diameter of the roll pieces 2b and 2f is the roll piece 2
The minimum outer diameter portions of a, 2c and 2e and the outer diameter of the roll piece 2d are equal to the maximum outer diameter portions of the roll pieces 2c and 2e, respectively.

The grooved strip 1 processed by using the forming roll 2 of the sixth embodiment has a strip-shaped tube inner surface forming area 1a parallel to the length direction corresponding to the roll pieces 2a to 2f.
To 1f are respectively formed. In the tube inner surface forming regions 1a, 1c, 1e of the grooved strip 1, a number of parallel grooves 11 inclined with respect to the length direction are respectively formed. The difference in the total thickness in the width direction of the grooved strip 1 is 0.1 mm or less. Therefore, the heat transfer tube welded by pipe forming with the grooved strip 1 is shown in FIG.
When the tube is expanded in the manner of 1, the outer shape is expanded to a state closer to a perfect circle. Other configurations, operations, and effects of the forming roll and the groove with a groove according to this embodiment are substantially the same as those of the first embodiment, and thus description thereof will be omitted.

Seventh Embodiment FIG. 17 is a partial plan view of the grooved strip forming roll of the seventh embodiment and the grooved strip being processed. The figure is a half plan view of the exit side of the grooved strip 1 in the forming roll 2.
Is constituted by roll pieces 2 a to 2 f fixed to the coaxial 20. The configuration of the roll pieces 2a, 2c and 2e is almost the same as that of the sixth embodiment, and the configuration of the roll pieces 2b, 2d and 2f is the same as that of the sixth embodiment. A large number of parallel grooves 21 intersecting at right angles to the shaft 20 are formed.

The grooved strip 1 processed by using the forming roll 2 of the seventh embodiment has a strip-shaped tube inner surface forming area 1a parallel to the length direction corresponding to the roll pieces 2a to 2f.
To 1f are respectively formed. In the tube inner surface forming regions 1a, 1c, 1e of the grooved strip 1, a large number of parallel grooves 11 inclined with respect to the length direction are respectively formed, and in the other tube inner surface forming regions 1b, 1d, 1f, A large number of grooves 11 parallel to each other along the length direction are formed. The difference in the total thickness in the width direction of the grooved strip 1 is 0.1 mm or less. Therefore, when the heat transfer tube welded by pipe forming by the grooved strip 1 is expanded in the manner shown in FIG. 22, the outer shape is expanded to a state closer to a perfect circle. The other configurations, operations, and effects of the forming roll and the groove with a groove according to this embodiment are almost the same as those of the sixth embodiment, and thus description thereof will be omitted.

[0042]

The groove with a groove for a heat transfer tube according to the first and second aspects has a plurality of band-shaped tube inner surface forming regions 1a to 1n parallel to each other along the length direction on one surface, and these tube inner surfaces are formed. A large number of parallel grooves 11 along the length direction in the formation regions 1a to 1n
The difference in the total thickness of both sides of the area where
Since it is formed as follows, when a welded heat transfer tube manufactured using this grooved strip is expanded by inserting a pipe expansion plug inside when manufacturing a cross fin heat exchanger, for example, The tube is expanded in a state in which the diameter is close to a perfect circle, and the adhesion between the fin and the outer peripheral surface of the heat transfer tube can be secured.

According to a third aspect of the present invention, there is provided a grooved roll for heat transfer tubes, wherein the metal strip is arranged between the roll and the pressure roll having a smooth peripheral surface.
In the heat-transfer-tube grooved-roll forming roll for forming the groove 11 on one surface of the metal strip 10 while rotating the metal strip 10 therebetween, the heat-transfer-tube grooved-row forming roll 2 has a predetermined length fixed to the coaxial 20. A plurality of roll pieces 2a to 2n of which the number of parallel grooves 21 having a predetermined lead angle with respect to the axis 20 are formed on the circumferential surface of the roll pieces 2a to 2n, When the roll piece makes one rotation, one end of the groove 21 is formed so that the diameter of the end that is in contact with the metal strip 10 at the end is smaller than the diameter of the other end. It can be used to smoothly process the groove for a heat transfer tube according to claim 1 or 2.

According to a fifth aspect of the present invention, there is provided a heat-transfer tube grooved strip forming roll according to the third or fourth aspect, wherein the difference between the outer diameters of both ends of the roll piece in which the groove 21 is formed. Since it is 0.5 mm or less, the grooved groove processed using this is a welded heat transfer tube with an inner groove that can smoothly expand in a state close to a perfect circle without lowering the heat transfer performance in the tube. Can be manufactured.

[Brief description of the drawings]

FIG. 1 is a partial plan view of a grooved roll for heat transfer tubes according to a first embodiment of the present invention and a grooved line being processed.

FIG. 2 is a half cut sectional view of the forming roll of FIG. 1;

FIG. 3 is a partial perspective view showing a state where a grooved groove is being processed by a processing device using the forming roll of FIG. 1;

4 is a partially enlarged cross-sectional view of a groove with a groove processed by the processing apparatus of FIG. 3;

5 is a graph showing a comparison of the total thickness at each position in the width direction of the grooved strip processed by the processing apparatus of FIG. 3 and a grooved strip processed by a conventional processing apparatus.

FIG. 6 is a half plan view of a grooved roll for heat transfer tubes according to a second embodiment.

FIG. 7 shows a comparison of the total thickness at each position in the width direction between a grooved groove processed using the forming roll of FIG. 6 and a grooved groove processed using a conventional forming roll. It is a graph.

FIG. 8 is a half plan view of a grooved roll for heat transfer tubes according to a third embodiment.

FIG. 9 shows a comparison of the total thickness at each position in the width direction between a grooved groove processed using the forming roll of FIG. 8 and a grooved groove processed using a conventional forming roll. It is a graph.

FIG. It is a partial expanded sectional view showing the state where a grooved roll is processed by a forming roll of a third embodiment.

FIG. It is a partial expanded sectional view showing the state where a grooved roll is processed by the forming roll of the ninth embodiment.

FIG. 12H is a schematic plan view of a forming roll composed of two roll pieces, and FIG. 12I is a schematic plan view of a forming roll composed of six roll pieces.

FIG. 13 is a partially enlarged cross-sectional view showing a portion where a groove of a forming roll is formed.

FIG. 14 is a partial plan view of a forming roll according to a fourth embodiment and a groove with a groove being processed.

FIG. 15 is a partial plan view of a forming roll according to a fifth embodiment and a groove with a groove being processed.

FIG. 16 is a partial plan view of a forming roll according to a sixth embodiment and a groove with a groove being processed.

FIG. 17 is a partial plan view of a forming roll according to a seventh embodiment and a groove with a groove being processed.

FIG. 18 is a partial perspective view showing a processing apparatus using a conventional heat transfer tube grooved strip forming roll and a grooved strip being processed by the processing apparatus.

FIG. 19 is a partially enlarged cross-sectional view of a conventional forming roll and a groove with a groove being processed by the forming roll.

FIG. 20 is a graph showing a difference in total thickness, a difference in groove depth, and a groove bottom thickness at each position in a width direction of a grooved strip processed by a conventional forming roll.

FIG. 21 is a partial plan cross-sectional view showing a state in which a heat transfer tube with an inner surface groove is expanded in a manufacturing process of the cross fin heat exchanger.

FIG. 22 is a partially enlarged cross-sectional view showing a state in which a heat transfer tube welded and formed using a conventional groove for a heat transfer tube is expanded and fixed in a hole of a fin of a cross-fin heat exchanger.

[Explanation of symbols]

 1,5 Grooved strip 10,50 Metal strip 11,51 Groove 1a-1g, 5a-5d Tube inner surface forming area 2,4 Grooved strip forming roll 20,40 Shaft 21,41 Groove 2a-2f, 4a-4d Roll Piece 2g Spacer 3 Pressure roll 6 Heat transfer tube 60 Expansion plug 7 Fin 70 Hole 71 Gap a to g End of roll piece in grooved strip forming roll A to E End of each area of grooved strip D1 Maximum outer diameter D2 Minimum outer diameter part H Depth of groove 21 h Depth of grooves 11, 51 T Total thickness t Groove bottom thickness

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yasutoshi Mori 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Inside Furukawa Electric Co., Ltd.

Claims (5)

[Claims] 1. A plurality of tube-shaped tube inner surface forming regions 1a to 1n parallel to each other along a length direction on one surface, and at least a part of the tube inner surface forming regions includes a large number of tubes inclined with respect to the length direction. A parallel groove 11 is formed, and the difference in the total thickness (the thickness between the top of the fin between the grooves formed on one surface and the other surface) in the width direction both sides in the part of the tube inner surface forming region is reduced. 0.
Grooves for heat transfer tubes, characterized in that they are less than 1 mm. 2. A plurality of parallel grooves 11 inclined in a direction opposite to the grooves 11 formed in the part of the tube inner surface forming region are formed in another part of the tube inner surface forming region. The difference in the total wall thickness of both sides in the width direction of a part of the tube inner surface forming region is 0.1
The groove for a heat transfer tube according to claim 1, wherein the groove is not more than mm. 3. A heat-transfer tube grooved strip forming roll for forming a groove 11 on one surface of a metal strip 10 while rotating the metal strip 10 with the pressure roll 3 having a smooth peripheral surface. The heat transfer tube grooved strip forming roll 2 includes a plurality of roll pieces 2 a to 2 n having a predetermined length fixed to the coaxial 20. A large number of parallel grooves 21 having corners are formed, and one end of the groove 21 comes into contact with the metal strip 10 lastly when the part of the roll piece makes one rotation. A grooved roll for heat transfer tubes, wherein the diameter of the end on the side is smaller than the diameter of the other end. 4. On the peripheral surface of another part of the roll pieces, a number of parallel grooves 21 having a lead angle opposite to that of the grooves 21 formed on the part of the roll pieces with respect to the shaft 20. Is formed, and when the roll piece makes one rotation, one end of the groove 21 formed in the roll piece is the end on the side where the one end of the groove 21 finally comes into contact with the metal strip 10. The grooved roll for a heat transfer tube according to claim 3, wherein the diameter of the portion is formed smaller than the diameter of the other end. 5. The difference in outer diameter between both ends of the roll piece in which the groove 21 is formed is 0.5 mm or less.
Or the grooved roll for heat transfer tubes according to 4.