JPH11248384A - Heat exchanger, method of manufacturing the same, and refrigeration equipment using the heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance heat transfer efficiency between a plurality of heating tubes press fitted in fins while being arranged at a specified interval and the tins by caulking a burring part formed in the fins at the time of press fit thereby bringing the fins into contact with the heating tubes. SOLUTION: The heat exchanger comprises heating tubes 2, fins 3 and bent pipes wherein the tin 3 is provided with a circular rib 3a concentric to a hole for press fitting the heating tube 2. When the heating tube 2 is press fitted, periphery of the hole in the fin 3 is pushed out to form a burring part 3b. The burring part 3b has gently curved root part and forward end slightly touching the heating tube 2. Since the gap between the heating tube 2 and the burring part 3b of the fin 3 is 1 μm or less when the fin 3 is made of a plate of 0.2 mm thick, contact area between the heating tube 2 and the fin 3 can be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger in which a plurality of fins are provided in a straight portion of a heat transfer tube, a method of manufacturing the same, and a refrigeration apparatus using the same, such as a refrigerator and an air conditioner. is there.

[0002]

2. Description of the Related Art As a heat exchanger and a method of manufacturing the same, for example, Japanese Patent Application Laid-Open No. Hei 5-87480, Japanese Patent Publication No. Hei 6-63.
The technology disclosed in Japanese Patent Application Laid-Open No. 710, Japanese Patent Application Laid-Open No. 7-19778, and the like has been proposed.

In these techniques, a fin having a burring process having an opening smaller than the outer diameter of a heat transfer tube to be press-fitted is arranged at predetermined intervals, and a pipe is press-fitted to manufacture a heat exchanger. .

In these techniques, when a heat transfer tube is press-fitted, the burring portion is pushed out, so that the fins are supported on the heat transfer tube and the heat exchanger can be efficiently installed without expanding the diameter of the heat transfer tube. Can be manufactured.

[0005]

However, in each of the above prior arts, the fins are subjected to burring in advance, so that the manufacturing process is complicated. Further, since the heat transfer tube is pressed into the hole hardened by the burring process, a large insertion force is required.

Further, the root of the burring portion becomes a gently curved surface due to the press-fitting of the heat transfer tube, and a gap of several tens of μm is generated between the heat transfer tube and the fin, thereby reducing the heat transfer efficiency between the heat transfer tube and the fin. Let me.

In addition, since the fins are formed with burring portions in advance, if the fins are manufactured alone, the manufactured fins cannot be stacked and stored. Fin management becomes complicated. In addition, a large space is required for the storage.

[0008] In view of the above circumstances, an object of the present invention is to provide a heat exchanger that improves the heat transfer efficiency between a heat transfer tube and a fin and is easy to manufacture. Another object of the present invention is to provide a method for manufacturing the heat exchanger. Still another object of the present invention is to provide a refrigerating device such as an air conditioner and a refrigerator using the heat exchanger.

[0009]

In order to achieve the above object, according to the first aspect of the present invention, a plurality of heat transfer tubes are formed by forming a hole smaller than an outer diameter of the heat transfer tube. In the heat exchanger pressed into the fins arranged at intervals, when the heat transfer tube was pressed into the fin, a burring portion formed on the fin was caulked, and the fin was brought into contact with the heat transfer tube.

[0010] The invention described in claim 2 is the same as the claim 1.
In the invention described in (1), the fin has a rib formed concentrically with the hole around the hole into which the heat transfer tube is press-fitted.

[0011] The invention according to claim 3 is based on claim 1.
Alternatively, in the invention according to claim 2, a cross-sectional shape of the fin attachment portion of the heat transfer tube is formed into an elliptical shape by caulking.

According to a fourth aspect of the present invention, there is provided a heat exchanger wherein a plurality of heat transfer tubes are press-fitted into fins having holes smaller than the outer diameter of the heat transfer tubes and arranged at predetermined intervals. In the method, the heat transfer tube is press-fitted into the fin, and a burring portion of the fin formed by press-fitting the heat transfer tube is caulked.

Further, according to a fifth aspect of the present invention, in the refrigeration equipment, the plurality of heat transfer tubes are press-fitted into fins having holes smaller than the outer diameter of the heat transfer tubes and arranged at predetermined intervals. By crimping a burring portion formed on the fin, the heat exchanger having the elliptical cross-sectional shape of the fin mounting portion of the heat transfer tube is moved through the heat exchanger so that the major axis of the heat transfer tube flows through the heat exchanger. They were arranged so as to be parallel or perpendicular to the direction.

[0014]

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

FIGS. 1 to 4 show an embodiment of the heat exchanger according to the present invention. FIG. 1 is a perspective view of the heat exchanger according to the present invention, and FIG. 2 is a side view of the heat exchanger in FIG. FIG. 3 is an enlarged cross-sectional view showing a state in which the heat transfer tubes and the fins of the heat exchanger in FIG. 1 are connected, and FIG. 4 is a characteristic diagram showing heat exchange characteristics of the heat exchanger.

In FIG. 1, a heat exchanger 1 includes a heat transfer tube 2 formed in a hairpin shape, fins 3 and a vent pipe 4. The fin 3 has a rib 3a formed concentrically with a hole into which the heat transfer tube 2 is press-fitted. The burring portion 3 formed by press-fitting the heat transfer tube 2
b is swaged from the periphery and is in contact with the heat transfer tube 2. In addition, 100 indicates the flow direction of air to the heat exchanger 1.

With such a configuration, the gap between the heat transfer tube 2 and the burring portion 3b of the fin 3 has a thickness of 0.1 mm.
When using 2 mm aluminum fins 3, 1
μm or less, and the contact area between the heat transfer tube 2 and the fin 3 increases.

The flow rate of air applied to the conventional heat exchanger in which the heat transfer tubes are press-fitted into the fins and the heat exchanger 1 of the present invention, which has been caulked after press-fitting, are changed to obtain an equivalent heat transfer coefficient α of the heat exchanger and ventilation. FIG. 4 shows the result of measuring the resistance ΔP.

As is apparent from FIG. 1, the heat exchanger 1 of the present invention has a substantially improved heat transfer efficiency of about 20% and a reduced ventilation resistance of about 15%. This is because the contact with the heat transfer tube is insufficient, and the burring portion that has been expanded so as to protrude into the air passage is formed so as to be in contact with the heat transfer tube by caulking.

The caulking of the burring portion 3b may be caulked so as not to deform the heat transfer tube 2,
The heat transfer tube 2 may be deformed to such an extent that the fine grooves formed therein are not crushed (about several percent of the diameter), and the cross section may be formed into an elliptical shape.

The ribs 3a are provided to prevent the fins 3 from buckling when the burring portion 3b is swaged. Therefore, only the fins having the ribs 3a are used as shown in FIG. Instead, a flat plate without ribs 3a may be used. Further, as shown in FIG. 2, a slit 3c may be formed.

5 to 11 show a method of manufacturing a heat exchanger according to the present invention. FIG. 5 is a side sectional view showing a heat transfer tube press-fitting process, and FIG. 6 shows a heat transfer tube press-fitting process. Front view, FIG. 7 is an enlarged view showing a contact state between a press-fitted heat transfer tube and a fin, FIG. 8 is a side sectional view showing a caulking step,
9 is a front view showing a caulking step, FIG. 10 is a front view showing a caulking step when the heat transfer tube is formed into an ellipse, and FIG.
FIG. 4 is an enlarged view showing a state of contact between the heat transfer tubes and the fins after caulking.

As shown in FIGS. 5 and 6, the heat transfer tube 2 is inserted into the holes 3d for press-fitting the heat transfer tubes and the fins 3 formed with the ribs 3a concentrically with the holes 3d and arranged at predetermined intervals. It is positioned and press-fitted so that its axis coincides with the axis of the hole 3d.

When the heat transfer tube 2 is press-fitted,
The periphery of d is extruded to form a burring portion 3b. At this time, for example, as shown in FIG. 7, the burring portion 3 b has a gentle curved surface at the root portion and a shape in which the tip is slightly in contact with the heat transfer tube 2.

After the press-fitting of the heat transfer tube 2, the burring portion 3b is caulked by the caulking jig 8 inserted between the adjacent fins 3, as shown in FIGS. At this time, as shown in FIG. 9, if a burring jig 8 having a circular pressurizing portion is used, the burring portion 3b can be caulked in a state where the cross section of the heat transfer tube 2 is circular. In addition, as shown in FIG. 10, the use of the caulking jig 8 having an elliptical pressurizing portion allows the cross section of the heat transfer tube 2 to be formed in an elliptical shape.

When the burring b 3b is swaged, FIG.
As shown in FIG. 1, the burring portion 3b of the fin 3 comes into contact with the heat transfer tube 2 from its root.

When the burring portion 3b is swaged, the fins 3 are pulled at the root of the burring portion 3b.
a deforms to prevent the fins 3 from buckling. Therefore,
In the case of a fin having a strength that does not cause buckling due to caulking, the rib may not be formed.

FIG. 12 shows an air conditioner using the heat exchanger according to the present invention, and FIG. 12 is a configuration diagram of the air conditioner.

In FIG. 1, reference numeral 10 denotes an indoor unit of an air conditioner. Reference numeral 11 denotes a cross-flow fan, which is rotatably disposed in the indoor unit 10 and is rotationally driven by a drive source (not shown). Reference numeral 12 denotes a heat exchanger, in which a heat transfer tube is formed into an elliptical shape, and
1.

The heat exchanger 12 is provided with an air flow 1
The heat transfer tubes are arranged so that the major axis of the heat transfer tubes is parallel to 00.

Therefore, the ventilation resistance of the air passing through the heat exchanger 12 is reduced, and the power for operating the recirculation fan 11 can be reduced.
It is possible to reduce the size of devices such as a motor that drives the motor 1, to save power, and to reduce the size of the indoor unit 10.

FIGS. 13 to 15 show a refrigerator using the heat exchanger according to the present invention. FIG. 13 is a structural view of the refrigerator, and FIG. 14 is a perspective view of the heat exchanger used in the refrigerator. FIG. 15 is an enlarged view showing a connection state between the heat transfer tubes and the fins of the heat exchanger in FIG.

In FIG. 13, 19 is a refrigerator. Reference numeral 20 denotes a housing of the refrigerator 10, and includes a refrigerator compartment 21, a freezer compartment 22, and a freezer compartment 2.
An outlet 23 for sending out cool air toward 1, a cool air communication hole 24 for circulating cool air from the freezer compartment 22 to the refrigerator compartment 21, a return hole 25 for sucking cool air in the refrigerator compartment 22, and a return hole for sucking cool air in the refrigerator compartment 21. 26, a passage 27 for guiding the cool air sucked from each return hole 25, 26 is formed.

A door 28 is swingably supported by the opening of the refrigerator compartment 21. A door 29 is swingably supported by the opening of the freezing compartment 22. Reference numeral 30 denotes a compressor, which is arranged below the housing 20. Reference numeral 31 denotes a fan, which is disposed on the upper part of the housing 20 so as to face the outlet 23, and 32 denotes a heat exchanger, which is disposed in the passage 27. This heat exchanger 32, as shown in FIG.
The fins 3 are arranged on the heat transfer tube 2 so that the distance from the upstream side to the downstream side of the air flow 100 in the refrigerator becomes narrower, and as shown in FIG. Is formed so as to be orthogonal to the flow 100 of FIG.

In such a heat exchanger 32, the heat transfer tubes 2 are press-fitted into a plurality of groups of fins 3 arranged at predetermined intervals in advance.
After caulking the burring portion 3b formed on the fin 3,
It can be formed by meandering the heat transfer tube 2.

In such a heat exchanger 32, since the heat transfer tube 2 is elliptical, a turbulent flow is likely to be generated on the downstream side of the heat transfer tube 2, so that the heat transfer efficiency is higher than in the case where the cross section is circular. Is improved by about 20%. On the other hand, the generation of turbulence increases the ventilation resistance in the heat exchanger 32 by about 10%, but the refrigerator 1 including the return holes 25 and 26 and the passage 27
Nine ventilation resistance increases by several percent.

Accordingly, the cooling efficiency can be improved, and the power consumption of the refrigerator 19 can be reduced. In addition, fan 31
Can be reduced in size to expand the storage space in the refrigerator 19.

[0038]

As described above, according to the heat exchanger of the present invention, the contact area between the heat transfer tubes and the fins can be increased, the heat transfer efficiency can be improved, and a high-performance heat exchanger can be provided. .

Further, according to the heat exchanger manufacturing method of the present invention, a heat exchanger having high heat exchange efficiency can be manufactured only by using a simple caulking jig.

Further, in the refrigeration equipment using the heat exchanger according to the present invention, the heat exchange efficiency of the heat exchanger is improved, so that power saving can be achieved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a heat exchanger according to the present invention.

FIG. 2 is a side sectional view of the heat exchanger in FIG.

FIG. 3 is an enlarged cross-sectional view showing a state of connection between the heat transfer tubes and the fins of the heat exchanger in FIG.

FIG. 4 is a characteristic diagram showing heat exchange characteristics of the heat exchanger.

FIG. 5 is a side sectional view showing a step of press-fitting the heat transfer tube.

FIG. 6 is a front view showing a press-fitting step of the heat transfer tube.

FIG. 7 is an enlarged view showing a contact state between a press-fitted heat transfer tube and a fin.

FIG. 8 is a side sectional view showing a caulking step.

FIG. 9 is a front view showing a caulking step.

FIG. 10 is a front view showing a caulking step when the heat transfer tube is formed into an ellipse.

FIG. 11 is an enlarged view showing the state of contact between the heat transfer tubes and the fins after caulking.

FIG. 12 is a configuration diagram of an air conditioner using the heat exchanger according to the present invention.

FIG. 13 is a configuration diagram of a refrigerator using the heat exchanger according to the present invention.

FIG. 14 is a perspective view of a heat exchanger used in the refrigerator shown in FIG.

FIG. 15 is an enlarged view showing a state in which the heat transfer tubes and the fins of the heat exchanger in FIG. 14 are connected.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Heat exchanger, 2 ... Heat transfer tube, 3 ... Fin, 3a ... Rib,
3b: burring portion, 3d: hole, 10: indoor unit of air conditioner, 12 heat exchanger, 19: refrigerator, 32: heat exchanger.

Claims (5)

[Claims] 1. A heat exchanger formed by press-fitting a plurality of heat transfer tubes into fins having holes smaller than the outer diameter of the heat transfer tubes and arranged at predetermined intervals. A heat exchanger wherein a burring portion formed on the fin is caulked when press-fitted, and the fin is brought into contact with the heat transfer tube. 2. The heat exchanger according to claim 1, wherein the fin is formed with a rib concentric with the hole around the hole into which the heat transfer tube is press-fitted. 3. The heat exchanger according to claim 1, wherein a cross-sectional shape of the fin mounting portion of the heat transfer tube is formed into an elliptical shape by caulking. 4. A method for manufacturing a heat exchanger, wherein a plurality of heat transfer tubes are press-fitted into fins having holes smaller than the outer diameter of the heat transfer tubes and arranged at predetermined intervals. And crimping a burring portion of the fin formed by press-fitting the heat transfer tube. 5. A method in which a plurality of heat transfer tubes are press-fitted into fins having holes smaller than the outer diameter of the heat transfer tubes and arranged at predetermined intervals, and then crimping a burring portion formed in the fins. The heat exchanger in which the cross-sectional shape of the fin mounting portion of the heat transfer tube is formed in an elliptical shape is arranged such that the long diameter of the heat transfer tube is parallel or orthogonal to the flow direction of air passing through the heat exchanger. Characterized refrigeration equipment.