JP2002130983A - Extruded tube having multiple minute holes for heat exchanger, and heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide extruded tubes for a heat exchanger, in which even when tube ends are tapered by swaging, all of minute holes are made open in at most 1 mm opening-width, in an arrangement of many rows in the transverse direction of the cross section, and further provide a heat exchanger in which the tubes are used. SOLUTION: Minute holes 2 of at most 1 mm opening-width are arranged axially in the intermediate part of the cross section of the tube in many rows. A pair of end minute holes 4 are formed integrally beforehand longitudinally in a width greater than the holes 2 on both ends of the section. In the sectional ends intersecting with the extrusion direction, parts 5 of an adequately smaller width than the holes 4 are formed by plastically deformed by swaging.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat extruded tube made of aluminum for use in a heat exchanger having a large number of openings of 1 mm or less formed in a longitudinal direction of a cross section of the tube through a partition wall. The present invention relates to an extruded tube and a heat exchanger using the same.

[0002]

2. Description of the Related Art A flat multi-hole extruded tube made of aluminum as shown in FIG. 5 is sometimes used as a condenser for a car cooler and other heat exchangers. The extruded tube main body 3a has a large number of rectangular intermediate holes 2a arranged in parallel in the longitudinal direction of the transverse section via the narrow partition wall portion 1, and the openings at both ends in the longitudinal direction are provided with cross sections. Semicircular end micro holes
13 are formed. In such an extruded tube, especially when a gas refrigerant flows, in order to increase the heat radiation area in the tube, each width of the intermediate hole 2a, the end minute hole 13, and the partition wall 1 should be as small as possible. preferable.

[0003] In general, an extruded tube is formed by bending a tube in a meandering shape, or by arranging a large number of tubes cut to an appropriate length in parallel as shown in FIG. There is. In order to fix the extruded tube through the header, a number of flat holes matching the outer periphery of the tube are drilled in the header in advance, and each tube end is inserted into the hole, and the insertion portion is brazed and fixed in a liquid-tight manner. Was. Then, in order to smoothly insert the tube end into the flat hole, the edge of the flat hole is slightly burred, or the end of the extruded tube is swaged slightly as shown in FIG. It is necessary to cut the tip portion into a tapered shape.

[0004]

An extruded tube having multiple holes is formed as shown in FIG. 5, and intermediate holes 2a are formed at equal intervals through a thin partition wall 1 in the longitudinal direction of the cross section. End micro holes 13 are provided at both ends of the long axis. In order to smoothly insert the end of the extruded tube main body 3 into the flat hole of the header 7, it is troublesome to cut the tip of the extruded tube into a tapered shape, and it is generated at the time of cutting. Chips may enter the tube. When the end portion is swaged in a tapered shape as shown in FIG. 6, when each hole is finely formed, the tip of the end minute hole 13 is almost closed as shown in FIG. It was found that the heat exchange medium could not be circulated in the micro holes 13.

[0005] Therefore, the present invention provides a fine multi-hole which can maintain the heat exchange performance as high as possible by preventing the pair of fine holes at the end even if both ends of the extruded tube are reduced by swaging. An object of the present invention is to provide an extruded tube for a heat exchanger having a heat exchanger and a heat exchanger using the same.

[0006]

According to the first aspect of the present invention, the outer periphery of the cross section of the tube is formed to be flat, and the cross section of the tube is extended in the longitudinal direction of the tube through the partition wall 1 respectively. 1
An extruded tube main body 3 formed by extrusion molding in which a large number of intermediate micro holes 2 having an opening width of not more than mm are formed at both ends in the long axis direction of the extruded tube main body 3, and are larger than the intermediate micro holes 2. A pair of end microholes 4 formed integrally in advance with a large width, and cut ends crossing the extrusion direction of the extruded tube body 3 are formed at both ends in the long axis direction, respectively. A swaging portion 5 plastically deformed toward the intermediate fine hole 2 side with a width sufficiently smaller than the width of the hole 4;
And an extruded tube for a heat exchanger having fine multi-holes comprising:

According to a second aspect of the present invention, in the first aspect, a pair of ridges 6 are integrally formed in advance on the opposite surface of the inner surface of the intermediate portion in the longitudinal direction of the end minute hole 4. And an extruded tube for a heat exchanger having a fine multi-hole in which the swaging portion 5 is formed so as to reach the ridge 6. According to a third aspect of the present invention, there is provided a heat exchanger using the extruded tube according to the first or second aspect, wherein both ends of the extruded tube have flat holes 14 in the header 7.
, And the insertion part is liquid-tightly joined to the heat exchanger.

[0008]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an extruded tube for a heat exchanger having a fine multi-hole according to the present invention, in which a swaging portion 5 is formed at a cut end thereof.
FIG. 1B is a side view, and FIG. 1B is a sectional view taken along the line BB of FIG. 1A. FIG. 2A is a side view of the extruded tube before the swaging process, and FIG.
FIG. 4A is a cross-sectional view taken along line BB of FIG. FIG. 3A is an explanatory cross-sectional view of a main part of a heat exchanger using the extruded tube of the present invention, and FIG. 4 is an enlarged view taken along line AA in FIG. FIG. 3B is an enlarged view of a portion B in FIG. FIG. 4 is an explanatory view showing an example of a heat exchanger to which the extrusion tube of the present invention is applied.

The extruded tube is made of aluminum or an alloy thereof, and is continuously extruded using a die as an example. The outer periphery of the cross section of the tube is formed flat, and a large number of rectangular intermediate holes 2 having an opening width of 1 mm or less are arranged in parallel in the long axis direction through partition walls 1 which are extremely thin in the long axis direction. It was done. At both ends in the major axis direction, there are intermediate micro holes 2
A pair of end micro holes 4 integrally formed in advance with a larger width (about 2 to 4 times in this example) is formed as shown in FIG.
A pair of ridges 6 are formed on surfaces facing each other at an intermediate portion in the major axis direction. Then, as shown in FIG. 2, the extruded tube main body 3 formed by extrusion is cut in a direction intersecting the extrusion direction, and swaging portions 5 are formed at both ends in the long axis direction of the cut portion. This swaging part 5
Is formed in a taper that becomes thinner toward the end face of the tube, and its tip reaches the ridge 6.

In this example, as shown in FIG. 3, the flat hole 14 of the header 7 into which the tip of the extruded tube body 3 is inserted is not or hardly burred in the long axis direction, and is not burred in the short axis direction. Since the processed portion 15 is formed, the extruded tube main body 3 is swaged only in the long axis direction and the outer periphery of the distal end portion is tapered, so that the flat hole 14 is formed.
Can be easily inserted. That is, the header 7 in this example is formed by pressing a pipe made of aluminum. After the flat hole is formed, the edge of the flat hole is burred. At this time, the pipe is easily deformed in the short axis direction, but is not easily plastically deformed in the long axis direction because the rigidity of the pipe material acts strongly. In the case where burring is not performed in the short axis direction, it is preferable to perform swaging in the short axis direction of the cross section at the end of the extruded tube main body.

The extruded tube body 3 thus constructed
Is inserted into the flat hole 14 of the header 7 as shown in FIGS. The flat holes 14 are formed at regular intervals so as to be spaced apart from each other in the axial direction of the header 7, and the inner periphery thereof is aligned with the outer periphery of the extrusion tube main body 3. Therefore, the tip of the tapered swaging portion 5 is inserted into the flat hole 14 of the extruded tube body 3 and press-fitted as shown in FIG. Make sure that the end that has passed through is in contact. Then, the contact portions are brazed and fixed. In the brazing, there is a case where a brazing material is supplied to the insertion portion, and a case where the surface of one of the parts that comes into contact with each other is coated with the brazing material in advance. In the latter case, the brazing material is melted in a high-temperature furnace and then cooled and solidified, so that the contact portions can be brazed and fixed in a liquid-tight manner.

As shown in FIG. 4, fins 11 are arranged between the outer surfaces of the respective extruded tube bodies 3, and the portions between the fins 11 and the contact portions with the extruded tube bodies 3 are similarly brazed. Note that this example is a condenser for a car cooler as an example, and a refrigerant is supplied from an inlet pipe 9 of a left header 7, and the presence of a pair of partitions 12 causes the plurality of partitions 12 to be parallelized in a plurality of extrusion tube bodies 3. Meandering in a flow and multi-pass type,
It reaches the lower part of the partition 12 of the right header 7. Then, air is blown to the outer surface of the extrusion tube main body 3 and the outer surface of the fins 11, heat exchange is performed between the blown air and the refrigerant, and the refrigerant flows out to the outside as liquid from the outlet pipe 10. is there.

[0013]

Next, an example of an extruded tube for a heat exchanger having a fine multi-hole according to the present invention will be described. 1 and 2, the width W in the major axis direction of the cross section of the extruded tube main body 3 is about 16 mm, and the thickness Y in the minor axis direction is about 1.6 mm. The width of the intermediate portion fine hole 2 in the major axis direction is 0.5.
It is a rectangle having a height of about 5 mm and a height of about 0.8 mm, and the thickness of the partition wall 1 is about 0.2 mm. The intermediate minute holes 2 and the partition walls 1 are arranged at equal intervals, and the end minute holes 4 are arranged at the both ends. The end minute hole 4 has a width in the long axis direction of about 1.55 mm, and the distance from the surface of the partition wall 1 to the center of the ridge 6 is. It is about 0.67 mm. The thickness u of the outer periphery of the extruded tube body 3 is 0.4
1A of the swaging portion 5 was about 0.65 mm. Needless to say, these values can be appropriately changed according to the conditions of various heat exchangers.

According to an experiment, when both ends of the cross section of the extruded tube main body 3 in the longitudinal direction are swaged,
Due to the presence of the ridges 6 arranged in the end minute holes 4 at both ends, it was found that the plastic deformation of the tip of the swaging portion 5 was stopped by the ridges 6 and it was difficult to further deform inward. . Therefore, the opening at the end of the end minute hole 4 is sufficiently secured, and the heat exchange medium can be circulated there. In addition, the ridges 6 increase the heat radiation area mainly in portions other than the swaging, and promote heat exchange. Note that θ in FIG. 1B was set to about 12 °. The length L of the swaging portion 5 in the extrusion direction was about 3 mm. By doing so, it has been found that the end can be easily fitted into the flat hole 14 of the header 7.

[0015]

According to the extrusion tube of the present invention,
End micro holes 4 are formed at both ends in the major axis direction of the cross section, and the width of the end micro holes 4 is formed larger than that of the intermediate micro holes 2. Is formed, and the plastic deformation of the processed part of the swaged part 5 is formed sufficiently smaller than the width of the fine hole 4 at the end. It is possible to prevent the fine holes from being blocked by plastic deformation of the aging processing portion 5, to ensure the flow path of the heat exchange medium even at both ends in the longitudinal direction of the cross section, and to improve the heat exchange performance. Moreover, due to the presence of the swaging portion 5, the extruded tube can be easily inserted into the flat hole of the header, and the extruded tube for a heat exchanger with high productivity can be obtained.

In addition to the above configuration, in the case where a pair of ridges 6 are integrally formed in advance in the minute hole 4 at the end, the positioning of the swaging portion 5 is facilitated by the ridge 6 and the swaging process is performed. The processing accuracy of the part 5 can be improved. In addition, the ridges 6 increase the heat radiation area mainly in portions other than the swaging, and promote heat exchange. Next, according to the heat exchanger of the present invention, it is easy to insert both ends of the extruded tube into the flat holes of the header, and it is easy to manufacture and the end minute holes 4 are not closed. The heat exchange medium can be circulated through all the fine holes of the tube, and a high-performance heat exchanger can be provided.

[Brief description of the drawings]

FIG. 1 is an extruded tube for a heat exchanger having a fine multi-hole according to the present invention, which has a swaging portion 5 at a cut end thereof.
FIG. 1A is a side view thereof, and FIG.
FIG. 1B is a cross-sectional view taken along the line BB in FIG.

2 (A) is a side view of the extruded tube before the cutting end is swaged, and FIG. 2 (B) is a view of FIG. -B arrow sectional drawing.

FIGS. 3A and 3B are cross-sectional views illustrating a main part of a heat exchanger using the extrusion tube of the present invention, wherein FIG. 3A is an enlarged view taken along the line AA in FIG. 4 and FIG. FIG.

FIG. 4 is an explanatory view showing an example of a heat exchanger to which the extrusion tube of the present invention is applied.

FIG. 5 is an end view showing an example of a conventional extrusion tube.

FIG. 6 is a cross-sectional view when the extrusion tube is swaged.

FIG. 7 is an end view when the extruded tube is swaged.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Partition wall part 2 Intermediate part fine hole 2a Intermediate part hole 3 Extruded tube main body 3a Extruded tube main body 4 End part fine hole 5 Swaging part 6 Ridge 7 Header 9 Inlet pipe 10 Outlet pipe 11 Fin 12 Partition 13 End part fine Hole 14 Flat hole 15 Burring processing part

Claims (3)

[Claims] 1. The outer periphery of a cross section of a tube is formed flat,
An extruded tube main body 3 formed by extrusion molding in which a large number of intermediate micro holes 2 having an opening width of 1 mm or less are arranged in the longitudinal direction of the section via a partition wall portion 1 in the longitudinal direction of the section, respectively; A pair of end micro holes 4 formed at both ends in the major axis direction of the longitudinal direction and having a width larger than that of the intermediate micro holes 2, and intersecting the extrusion direction of the extruded tube main body 3; A swaging portion 5 formed at each of both ends of the cut end portion in the long axis direction and plastically deformed toward the intermediate portion fine hole 2 with a width sufficiently smaller than the width of the end portion fine hole 4; An extruded tube for a heat exchanger having fine multi-holes comprising: 2. A pair of protrusions 6 according to claim 1, wherein a pair of ridges 6 are integrally formed in advance on an opposite surface of the inner surface of the intermediate portion in the long axis direction of the end minute holes 4 so as to reach the ridges 6. An extruded tube for a heat exchanger having a fine multi-hole in which the swaging portion 5 is formed. 3. A heat exchanger using the extruded tube according to claim 1 or 2, wherein both ends of the extruded tube are inserted into the flat holes 14 of the header 7, and the inserted portion is a liquid. Tightly joined heat exchanger.