KR100214427B1 - Tube for heat exchanger and manufacturing method - Google Patents

Abstract

In the heat exchanger tube according to the present invention, a pair of planar wall portions facing each other at regular intervals are continuous at one end via a U-shaped bent portion, and joined at the other end in contact with each other, or at regular intervals. A pair of forming plates are overlapped with their inner surfaces facing each other, and the abutting portions at both ends are joined to form a single flat tube.

Then, the facing flat wall portion has one or a plurality of curved protrusions protruding inward, and are joined in a state of being in contact with the end portion of the curved protrusion and the inner surface of the flat wall portion or the end portion of the corresponding curved protrusion, thereby becoming a single body.

Therefore, it is very thin and has excellent pressure resistance, and there is no manufacturing problem, so it is excellent in productivity and can be manufactured and supplied at a low cost.

Description

Heat exchanger tube and its manufacturing method

1 is a perspective view of a tube

(A), (b), (c), (d) is sectional drawing which shows the manufacturing process.

3 is a cross-sectional view of the tube of the modification

4 is a perspective view of a tube of still another modification

5 is a cross-sectional view of a tube of another modification

6 is a cross-sectional view of the tube according to the second embodiment.

Fig. 7 is a plan view showing the processing state of the strip-shaped material for manufacture thereof

8 is a cross-sectional view taken along line 8-8 in FIG.

9 is a perspective view of a tube according to a third embodiment

10 is a cross-sectional view of a tube showing a modification.

11 shows another modified example, (a) is a perspective view showing a state where two molding plates are separated, and (b) is a 11-11 in (a) view showing a bonding state of two molding plates. Section following the line

12 shows another modified example, (a) is a perspective view showing a state where the molding plates are separated, and (b) is a line 12-12 of (b) which shows a bonding state of two molding plates. Pouring section

13 is a front view showing one embodiment of a heat exchanger in which a tube according to the present invention is used.

14 is a cross-sectional view of a flat tube made of a conventional extruded material.

* Explanation of symbols for main parts of the drawings

(1), (1 '), (1' '), (1' ''), (21): flat tube (2), (3), (12), (13): flat wall portion

(6), (26): bend protrusion (16): dim pole type protrusion

(P1), (P2): forming plate

The present invention relates to a multiflow type flat tube for a heat exchanger, in particular a condenser for a car-cooler, and a manufacturing method thereof.

In the conventional car-cooler condenser, a serpentine tube type heat exchanger is generally used.

In other words, a hollow extruded flat tube called a harmonica tube is bent in an S shape, and a fin is formed between the parallel portions to form a core.

On the other hand, in recent years, the use of what is called a multiflow heat exchanger is also proposed and put into practical use also in condenser based on the request | requirement of reduction of the flow resistance of a refrigerant | coolant, improvement of heat exchange efficiency, compact weight, etc. in recent years.

For example, as shown in FIG. 13, the multiflow heat exchanger connects a plurality of flat tubes 33 through a pair of left and right pipe headers 31 and 32 so as to communicate with each other. A fin 34 is provided between the adjacent tubes 33 and 33, and is blocked by a partition 35 at a proper position in the longitudinal direction in the headers 31 and 32, so that one header 31 An S-shaped refrigerant circuit is formed from the refrigerant inlet 36 at the upper end of the upper end to the refrigerant outlet 37 at the lower end of the other header 32.

(See US Pat. No. 482594, etc.)

Since the tube 33 used in such a multiflow type heat exchanger requires pressure resistance that can sufficiently withstand the pressure applied by the refrigerant gas used, a porous flat tube made of aluminum extrusion material has been generally used. That is, as shown in FIG. 14, the cross section of the tube is elliptical, and there are one to a plurality of partitions 33b along the longitudinal direction of the tube, so that the inner space is divided into a plurality of independent refrigerant passages 33c. Compartments and formed ones are used.

By the way, as long as the tube 33 made of an extruded tube such as electricity is used, there is a limitation in manufacturing technology for lowering the tube stand H, and furthermore, there is a limit to improving the heat exchange efficiency. there was.

That is, in order to improve the heat exchange efficiency, it is preferable to reduce the flow resistance of the air passing through the core within the limited core area of the heat exchanger as much as possible, and to increase the contact area with the air, but the tube 33 The fact that the height (H) cannot be made low enough consequently increases the flow resistance of the air by the tube, restricts the number of tubes that can be installed within the limited core area, and sufficiently increases the heat transfer contact area with the air. You can.

In response to such a problem, it has recently been proposed to use a sealing tube for a tube.

(E.g., Japanese Patent Application Laid-Open No. 62-207572, etc.), when using an electric sealing tube, the tube wall can be made sufficiently thin, for example, about 0,4-0,5 mm, resulting in a tube height. Can be made extremely low, such as 1.5-1.7 mm. However, in the use as a condenser, as described above, the refrigerant gas sent from the compressor is a high pressure, so the tube of the extremely thin electric sealing tube is not enough to withstand the pressure of the refrigerant gas, and thus cannot be applied to practical use. .

For this reason, as shown in Japanese Patent Application Publication No. 62-207572, which was previously described in the conventional proposal, an inner fin material formed into a wave shape in the width direction is separately inserted into the flat sealing tube and soldered to the inner wall of the pipe wall. By joining, the fan member also has the function of a reinforcing member so that it can withstand the gas pressure at the time of cooling.

By the way, in the tube of such a conventional electric sealing tube, its manufacture is cumbersome, especially the work which inserts inner pin material in the whole length of the ultra-thin flat tube of height 1.5-1.7 mm is quite difficult, and more Furthermore, there existed a drawback that the productivity fell and manufacturing cost increased.

SUMMARY OF THE INVENTION The object of the present invention is to solve the above-mentioned problems and to lower the tube height sufficiently to improve the heat exchange efficiency, to provide a sufficient internal pressure, and to provide a heat exchanger tube most suitable for a patented condenser that can be easily manufactured. I would like to.

Another object of the present invention is to provide a method for producing such a heat exchanger tube.

Another object of the present invention will become more apparent from the following detailed description of the embodiments.

In the above-mentioned object, the heat exchanger tube according to the present invention has a pair of planar wall portions facing each other with a constant distance therebetween, one end of which is continuous through a U-shaped bent portion, and the other end of the tube for each other is joined to each other. It is a flat tube, and the flat wall portion described above has one or a plurality of curved protrusions projecting inward, and the inner surface of the flat wall portion facing the end of the curved protrusion, or the corresponding protrusion protruding from the wall portion. To be joined in contact with the end of the bending protrusion to be characterized in that it is bound to a single body.

In addition, another heat exchanger tube according to the present invention overlaps the bending protrusions in which a pair of forming plates having one or a plurality of bending protrusions formed on the inner surface thereof face each other from the inside, and joins both edges to form a single body. Characterized in that the flat tubular tube is joined in contact with the inner surface of the flat wall portion of the forming plate facing each other, or the end portion of the corresponding curved protrusion protruding from the wall portion, to form a unitary body. will be.

In the method for manufacturing a heat exchanger tube according to the present invention, a band-shaped material having a constant width is formed with one or a plurality of curved protrusions on each of the left and right sides of the central bending preliminary section. Next, in the central bending preliminary section where the belt-shaped material in which the bent projection is formed is folded to form a U-shaped cross section, the ends of the belt-shaped material are brought into contact with each other. This elliptical shape is formed of a flat tube which is in contact with the inner surface of the flat wall facing the end of the aforementioned curved projection, or the end of the corresponding curved projection protruding from the surface, and the end of the curved projection described above. It is characterized by joining the surface in contact with the soldering.

According to another method of manufacturing a heat exchanger according to the present invention, a band-shaped material having a constant width is formed on each of the left and right sides of the central bending preliminary part, respectively, and one or more curved protrusions are formed. In the central bending preliminary section where the strip-shaped material in which the projection is formed is folded in a U-shape so that both ends of the strip-shaped material abut each other, the cross-section is elliptical and It is formed of a flat tube which is in contact with the inner surface of the planar wall portion facing the end, or the end of the corresponding curved protrusion protruding from the surface, and then the portion where both ends of the belt-shaped material described above abut and the electric flexion. The surface abutting with the end of the projection is characterized in that the joining by soldering.

The above-mentioned curved protrusions are formed as a continuous double folded wall folded in the longitudinal direction of the tube, and by arranging the curved protrusions to alternately protrude from both opposing flat wall portions of the tube, the curved protrusions form an internal space in the tube. By separating the plurality of independent refrigerant passages may be formed.

In addition, the aforementioned curved protrusion partially recesses the flat wall portion of the tube, thereby forming a plurality of dimple-shaped protrusions, and the joints of the dimple-shaped protrusions have several joints. It may be to be formed as a refrigerant passage of.

Example 1

In the embodiment shown in Figs. 1 and 2, the tubes 1 for heat exchanger are mutually facing, for example, the upper and lower flat wall portions 2, 3 facing each other at an interval of 0.8 mm. It is continuous through the curved part 4 of shape, and the other end is welded 5 in the state which joined, and the cross section is an elliptical shape and becomes an electric sealing pipe formed in flat shape. In addition, the two curved protrusions 6 protruding from the inside are formed in the flat wall portions 2 and 3 described above so as to be alternately arranged in the width direction of the tube 1. have.

The curved projection 6 is formed by a curved double wall in which the aforementioned flat wall portion 2 is folded inward into a V shape and the two walls are brought into close contact with each other. The curved projections 6 are continuously formed along the longitudinal direction of the tube 1. It is.

Then, these curved protrusions 6 abut against inner surfaces of the flat wall portions 2 and 3 facing the ends of the curved protrusions, respectively, and the curved protrusions 6 and the flat wall portions 2 are brazed. ) And (3) as a unitary body, and the curved protrusions 6 themselves are joined together by soldering the adhesion surfaces of both walls of the curved double wall by soldering. These joining is performed using the applied solder by using the double-sided aluminum braging sheet which apply | coated both sides with solder as a raw material of a tube. The joining operation is performed simultaneously with the soldering operation of the fins 24 and the tube 1, the tubes 1, and the headers 21 and 22 at the time of assembling the heat exchanger.

Therefore, the tube 1 after the aforementioned soldering operation is performed, and the inner space of the tube 1 is divided into a plurality of sections in the width direction of the tube 1 with the flexion protrusion 6 as a partition wall, and the independent refrigerant passage (8) is formed.

In addition, the size of the tube 1 described above is preferably 0.15-0.5 mm, especially for example, 0.4 mm, tube width (w) of 12-20 mm, particularly for example, the tube wall thickness t thereof. 16 mm, tube height h is 1.2-2.0 mm, in particular 1.6 mm, for example.

The manufacturing of the tube 1 described above is performed in a band-shaped aluminum brazing sheet having a constant width as shown in FIG. 2 (b). One or a plurality of electric flexures 6 protruding from one side of each side are formed.

As shown in FIG. 2A, the formation of the curved protrusions 6 is perpendicular to the surface of the raw material with one side of the curved protrusions 6 in order to correctly set the formation position of the curved protrusions 6 in advance. A bead portion having a V-shape in which two surfaces are approximately deformed by forming an inclined shape so as to have an angle? (6 mm), and then, as shown in FIG. 2 (b), it was set as the shape which pressed the both surfaces of the bead part 6 전기 which contacted previously, and it shape | molds to a predetermined shape. It can be most suitably carried out by performing a regular trim processing.

Next, as shown in FIG. 2 (c), the band-shaped material 7 having the aforementioned bent protrusions 6 formed at the center in the width direction thereof is formed so as to have a U-shaped cross section. Bend with a radius of curvature of the bent, and bend the ends 7a, 7a so that they face each other, and make the ends 7a, 7a abut each other, so that the abutment is sealed. By welding 5, a part thereof is enlarged, and as shown in FIG. 2 (d), a flat tube having a predetermined dimension having an elliptical cross section is produced.

FIG. 3 shows a tube 1 'of the modified example, and projects at a lower height at a position corresponding to each of the flat wall portions 2 and 3, which the curved protrusions 6a and 6b face up and down. The ends of the bent projections 6a and 6b at the corresponding positions are joined together by soldering in a state where they are in contact with each other, thereby forming a single piece.

The other configuration is the same as in the above-described embodiment, and its manufacture is also carried out according to the above-described embodiment. FIG. 4 shows the tube 1 ″ of another modification, and the flat wall portions 2, 3 which are band-shaped materials facing each other from above and below each other, for example, at an interval of 0.8 mm, One end is continuous through the U-shaped bent portion (4) in which the bending preliminary government is folded, and the other end is made of a flat tube having an elliptical cross section joined together in a state where both end faces of the material are in contact with each other. .

At the other edges of the aforementioned flat wall portions 2 and 3, bent portions 2a and 3a for joining, each having a constant width, which are rolled inward and are in parallel, are formed. (2a) and (3a) are soldered 5 in the state which overlapped with each other. By taking such a joining structure, the workability is improved and the furnace ( Even in the case of soldering in the furnace, stable soldering is possible.

In this way, the joining of the bent portions 2a and 3a may be performed by soldering or electric welding. In the case of joining by soldering, it is also preferable from the viewpoint of workability to perform all at once in a furnace together with other heat exchanger components such as tubes. These solder joints are performed by using the aluminum brazing sheet coated on both sides with solder as the material of the tube, and the solder applied on both sides is used for the bonding. The joining operation is performed simultaneously with the soldering operation of the fins 24 and the tube 1, the tubes 1, the headers 21 and 22 in assembling the heat exchanger. The other structure is the same as the above-mentioned embodiment, and its manufacture is performed according to the above-mentioned embodiment.

FIG. 5 shows a tube 1 of another variant, and projects at low heights at the corresponding positions of the two flat wall portions 2, 3, which the bent projections 6a, 6b face up and down. The ends of the bent projections 6a and 6b at the corresponding positions are joined together by soldering in a state in which they are in contact with each other to form a unitary body.

Other configurations are the same as those shown in FIG. 4, and the manufacturing is carried out in accordance with FIG.

Example 2

6 to 8 show another embodiment.

In the present embodiment, the tube 11 is formed such that the curved protrusions 16 projecting inwardly from the upper and lower flat wall portions 12 and 13 partially recess the flat wall portions 12 and 13 described above. Thus, the cross-sections formed inside the flat wall portions 12 and 13 are formed so that the dimple-shaped protrusions having substantially hemispherical or U-shape are located at positions corresponding to each other from the top and bottom, and the ends of the dimple-shaped protrusions are in contact with each other. It is soldered and made in one piece.

Therefore, the inner space of the tube 11 is formed of the labyrinth type refrigerant passage 18 which is complexly refracted by the junction of the aforementioned dimple-shaped bending protrusion 16.

For this reason, in the tube 11 of this embodiment, while the refrigerant flows through the refrigerant passage 18, the bent projections 16 are stirred to further promote heat exchange.

The other structure of this tube 11 is the same as that of the Example shown in FIG. 1 and FIG. 2, and abbreviate | omits detailed description.

In addition, as shown in FIG. 7 and FIG. 8, the manufacture of the tube 11 uses the strip | belt-shaped aluminum brazing sheet 17 of fixed width at the predetermined | prescribed position of this sheet 17. As shown in FIG. A curved example in which the dimple-shaped curved protrusions 16 are formed and the curved protrusions 16 are positioned at the center in the width direction of the material so that the surfaces on which the curved protrusions 16 are formed face each other, as indicated by the dotted lines in FIG. After folding to form a U-shaped cross section at the government, the two ends of the material are brought into contact with each other and bonded by electric welding (5) to produce a flat tube material. The same applies to the case of the embodiment shown in.

Also in the case of the present embodiment (2), as the modified example, the bent projections 16 are formed in the upper and lower flat wall portions 12 and 13 with different positions, and the inner side of the flat wall portion facing the ends thereof. The surfaces may be brought into contact with each other, and the surfaces may be joined by soldering to form a single body.

Example 3

9 shows another embodiment.

In the present embodiment, the tube 21 is a flexure projection 26 in which two forming plates P1 and P2 are formed, in which the flexure protrusions 26 are formed to protrude inward so as to be alternately arranged in the width direction thereof. ) Are formed as a single body by joining the two edges overlapping each other so that faces formed from each other can face each other from the inside.

Two curved projections 26 are formed on the forming plates P1 and P2 on both the upper and lower sides.

On both edges of the above-mentioned forming plates P1 and P2, the bent portions 22a and 23a are formed by being folded in an L shape, respectively, and the bent portions 22a and 23a in contact with each other are in that state. The solders are joined to each other to form a single body.

However, instead of such soldering, it may be bonded by electric welding.

The other structure of this tube 21 is substantially the same as the case of Example (1) (2) mentioned above, and detailed description is abbreviate | omitted.

Also in the case of the present embodiment (3), as a modification thereof, the curved projections 26 are formed at positions corresponding to each other of the top and bottom flat wall portions 22 and 23, and the ends thereof abut each other and are in contact with each other. It may join by silver soldering and may consist of a single body.

Moreover, for the purpose of improving the assemblability of such a tube 21, it is preferable to make them temporarily fixed before joining both plates P1 and P2 into a single body.

For example, as shown in FIG. 10, the bent part 23a of the lower plate P2 is formed in a C shape in the whole length of the tube 21 ', and the bent part 23a is bent of the upper plate P1. The portion 22a may be enclosed.

In this case, the bent portions 22a and 23a respectively formed on both plates P1 and P2 are formed, and the bent portions 22a of the upper plate P1 are formed on the bent portions 23a of the lower plate P2. It can be easily assembled by inserting it.

In addition, as shown in Fig. 11A, a part of the bent portion 23a of the lower plate P2 is formed with a protrusion 23b that protrudes laterally, and the bent portion 22a of the upper plate P1 is formed. The cutting groove 22b is formed at the sympathetic position of b, and as shown in FIG. 11 (b), the protrusions 23b are bent and fixed toward the cutting groove 22b in a state where both plates P1 and P2 overlap. The tube 21 'may be assembled by bending and fixing the tube 21' protrusion 23b toward the cutting groove 22b.

Alternatively, as shown in Fig. 12 (a), protrusions 23c, which rise upwardly, are formed on the bent portions 23a of the lower plate P2, and correspond to the bent portions 22a of the upper plate P1. The engaging hole 22c into which the above-mentioned protrusion 23c can be fitted is formed, and as shown in FIG. 12 (b), the protrusion 23c is overlapped in the state where both plates P1 and P2 overlap. The tube 21 'may be assembled by pressing to fix it in the coupling hole 22c.

In the above embodiment, the bent portion 26 is formed along the longitudinal direction of the tubes 21, 21 ′, 21 ″, 21 ′ ″, but the planar wall portions 22, 23 are partially formed. It is recessed inwardly and formed so that the cross-section formed in the inside of the flat wall parts 12 and 13 is a hemispherical or U-shaped dimple-shaped protrusion at a position corresponding to each other from the top and bottom, and the tip of the dimple-shaped protrusion is The parts may be soldered in contact with each other to form a single piece.

In this case, the inner space of the tube is formed of a labyrinthic refrigerant passage that is complexly refracted by the junction of the dimple-shaped protrusions described above, and the refrigerant is agitated by the curved protrusions while the refrigerant flows through the refrigerant passage. Further promoted.

In addition, in Example 3, although the bent part was bent outward, it may be bent inward.

The tube for heat exchanger according to the present invention is made of a flat tube by bonding one sheet of band-shaped material bent as described above, or by bonding two sheet plates in an overlapping state, and thus the thickness of the tube wall. It can be made thin enough, and it is possible to produce a flat tube of a foil-like tube with a very low tube height.

In addition, the tube described above is formed in a single body by joining in the state where the gold bumps are formed on the flat wall portions facing each other from above and the ends thereof are in contact with the inner surface of the opposite flat wall portion or the ends of the gold crack projections facing each other. In addition, the aforementioned bent protrusion also serves as a reinforcing member, and has excellent compressive strength and pressure resistance, and can be made in no way inferior to a flat tube made of extruded material in terms of strength as a condenser tube.

Moreover, also in the manufacturing surface, since a predetermined bending process can be formed in advance on a flat strip-like material, it can be manufactured by joining by a normal joining method, so there is no difficulty in manufacturing, and it is excellent in productivity and manufactured at low cost. Can be supplied.

Further, when continuously forming the bent projections in the longitudinal direction of the tube, the pressure resistance of the tube and the bending strength in the longitudinal direction can be further improved, and when the bent projections are formed by dimple-shaped projections, the interior Since the refrigerant flowing through the stirring is agitated by the dimple-shaped projection, the heat exchange efficiency can be further improved.

Claims (12)

A pair of flat wall portions (2) and (3) facing each other at regular intervals are continuous at one end via U-shaped bends (4), and joined at opposite ends (5). It is a flat tube (1), and the aforementioned two flat wall portions (2), (3) has one or a plurality of curved protrusions 6 protruding inward, and the ends of the curved protrusions 6 face each other. Tubes for heat exchangers, characterized in that they are joined in a state of being in contact with the inner surfaces of the planar wall portions 2 and 3 or the end portions of the corresponding curved projections 6 protruding from the wall portions, and are unitary. The curved projection 6 is formed of two curved walls alternately formed at both flat wall portions 2 and 3, and two walls are in close contact with each other along the longitudinal direction of the tube. The tube for heat exchanger, characterized in that the inner space of the tube is formed into a plurality of independent refrigerant cylinders by the curved projections 6, respectively. The method of claim 1, wherein the bent projections 16 are formed by dimple-shaped projections by partially recessing the planar wall portions 12 and 13 inwardly, so that the junction portions of the dimple-shaped projections 16 are multiple. A tube for a heat exchanger, characterized in that the inner space of the tube is formed of a labyrinth refrigerant passage. A flat wall portion (2) (3) has bending portions (2a) (3a) for joining parallel to each other at its other end, and the bent portions (2a) (3a) overlap each other. Heat exchanger tube, characterized in that made in one piece by joining in. Both bent portions 22a and 23a are overlapped with the bent projections 26, which are formed by forming the forming plates P1 and P2 having one or a plurality of bent protrusions 26 formed on the inner surface of the flat wall, inward. A flat tube 21 made of a single body bonded to each other, and the inner end of the flat wall of the forming plate facing each other, or the end of the corresponding bent protrusion 26 formed in the wall thereof. A tube for heat exchanger, characterized in that formed in one piece by joining in abutted state. The forming plate (P1) (P2) has bending portions 22a and 23a for joining parallel to each other at both ends thereof, and the bending portions 22a and 23a are overlapped with each other. Heat exchanger tube, characterized in that made in one piece by joining in In the band-shaped material 7 having a constant width, one or more curved protrusions 6 protruding only from one side to each other on both the left and right sides of the central bending preliminary section are formed, and then the curved protrusions 6 are formed. The cross-section in the width direction of the material is elliptical by folding the band-shaped material in which the cross section is formed in the center bending preliminary section to make the cross section U-shaped, and putting the ends of the material back together. And the flat tube 1 in which the tip of the above-mentioned curved protrusion 6 is in contact with the end of the corresponding curved protrusion 6 protruding from the inner surface of the flat wall portion on the opposite side or protruding from the inner surface thereof. A method for manufacturing a heat exchanger tube, characterized in that the surface formed in contact with the end of the bent projection (6) is joined by soldering. The curved projection (6) according to claim 7, wherein the curved projection (6) is formed of a curved double wall in which two walls are in close contact with each other along the longitudinal direction of the strip-shaped material, and protrudes from the upper and lower flat wall portions (2) and (3). A method of producing a tube for heat exchanger, characterized in that the bending protrusions (6) are alternately formed in the width direction of the tube so as to partition the inner space of the tube (1) into a plurality of independent refrigerant passages. The method according to claim 7, wherein a plurality of bending protrusions (16) are formed in a strip-like material with dimple-shaped protrusions, so that the inner space of the tube (11) is joined to the end of the dimple-shaped bending protrusions by a joining portion. Method for manufacturing a tube for heat exchanger, characterized in that formed in the refrigerant passage. In the band-shaped material 7 having a constant width, one or more curved protrusions 6 protruding only on one side from each side on the left and right sides of the central bending preliminary section are formed, and then the curved protrusions 6 are formed. The cross-section in the width direction of the material is elliptical, and the bent projections are formed by folding the formed strip-shaped material in the center bending preliminary section to be U-shaped so that the end faces are opposite to both ends of the material. (6) formed of a flat tube (1) in contact with the end of the planar wall (2) on the opposite side, the inner surface of (3) or the corresponding end of the corresponding curved protrusion (6) projecting from the inner surface The method of manufacturing a heat exchanger tube according to claim 1, wherein a surface in which both ends of the material are in contact with each other and a surface in contact with the ends of the bending protrusions (6) are soldered together. The curved projection 6 is formed of a curved double wall in which two walls are in close contact with each other along the longitudinal direction of the strip-shaped material 7, and protrudes from both upper and lower planar wall portions 2, 3. The curved protrusions (6) are alternately formed in the width direction of the rule tube, so that the inner space of the tube (1) is partitioned and formed into a plurality of independent refrigerant passages, respectively. The method according to claim 10, wherein a plurality of flexing protrusions are formed in a strip-like material by dimple-shaped protrusions 16, and the inner space of the tube 11 is joined by the joint portion where the ends of the dimple-type bending protrusions 16 abut. Method for manufacturing a tube for heat exchanger, characterized in that formed by a labyrinth refrigerant passage