JP2003311353A - Heat exchanger core manufacturing method and the heat exchanger core - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an easily-manufactured plate fin type heat exchanger core which uses flat tubes and has high heat exchange performance. <P>SOLUTION: A large number of small slits 1 are formed at predetermined intervals in the longitudinal direction of a thin metal strip, and the thin metal strip is folded in a zigzag manner so that the folds of the metal strip are located at a center in the longitudinal direction of the slits 1 orthogonal thereto. Next, flat tubes 2 are inserted in the slits 1. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plate fin type heat exchanger having flat tubes, and more particularly to a type in which flat tubes are press-fitted into slits provided in the width direction of each plate fin.

[0002]

2. Description of the Related Art Conventionally, as a fin applied to a flat tube, a corrugated fin has been generally used for a condenser of an automobile radiator or a car cooler. It seems that this corrugated fin is technically reaching the saturation point, and at present, there are limits to how much the air resistance can be greatly reduced, how the performance is improved, and how the weight is reduced. Corrugated fins can also be used in radiators for automobiles, condensers for car coolers, and outdoor units for air conditioners exclusively for air conditioning. However, since drainage of condensed water and frost during heating operation pose problems, the inside of the air conditioner can be used. Heat exchanger (evaporator), heat pump outdoor unit, refrigerator,
It couldn't be used at all in a vending machine evaporator,
I have to say that it is a fin with low applicability. This is because when the heat exchanger is finished, the corrugated fins have extremely poor drainage due to their shape, and therefore frost formation and its development are rapid and defrosting is difficult.

A plate fin having a flat hole can remove the above-mentioned drawbacks of the corrugated fin, but unlike the case of using a circular cross-section tube (round tube), inserting the flat tube into the flat hole itself. Is not easy. In order to improve the insertability, it is necessary to make a large clearance between the flat hole and the outer periphery of the flat tube, and if this is done, the adhesion between the tube and the fin becomes poor and the performance may deteriorate. Flat tubes cannot be expanded as well as round tubes, so brazing is required to join the flat tubes to the flat holes.However, to ensure insertability, if a large clearance is used, the clearance will be The material does not rotate, the degree of bonding between the two becomes low, and the heat transfer property deteriorates.
On the contrary, if the clearance is made small to obtain sufficient brazing property, the insertability becomes poor and the productivity is extremely lowered.

If the flat tube is intentionally expanded and then brazed, the final bondability is improved even if the clearance is large. However, in that case, there is a drawback that a pipe expanding process is required, the process is redundant, the productivity is poor, and the capital investment becomes excessive. A flat multi-hole pipe may be used as the heat exchanger for air conditioning, but in this case, the pipe cannot be expanded.

Instead of providing a flat hole in the plate fin, a so-called click-type heat exchanger has also been proposed in which a slit is formed in the width direction from one edge of the plate fin and the flat hole is press-fitted therein. According to this method, it is easy to press-fit the tube from the side of the fin at least with a clearance between the slit and the tube, and as a result, the degree of adhesion between the tube and the fin is enhanced. Also,
Such a plate fin type heat exchanger with slit is
There is a defect in the consistency of aligning a large number of slits by collecting individual plate fins, and the handling thereof is troublesome.

[0006]

It is theoretically possible to form a large number of slits parallel to the width direction on the plate fin and press the flat tube from one edge of the slit, but in practice, it is possible. It is difficult to align the slits of each plate fin to form a fin assembly. In addition, when the tube is fitted, the slits do not align accurately, which results in poor core assembly. Therefore, a heat exchanger core of this type using a flat tube is recognized as being theoretically effective as a heat exchanger core, but at least to the knowledge of the inventor, it has not been put to practical use. It's a reality. Therefore, the present invention provides a method of manufacturing a heat exchanger core, which has substantially the same slit alignment of each plate fin and is substantially the same as a plate fin type heat exchanger excellent in mass productivity, and a heat exchanger core thereof. This is an issue.

[0007]

According to the present invention as set forth in claim 1, a thin strip-shaped metal plate is provided with slits elongated in the longitudinal direction thereof.
A large number of (1) are formed at regular intervals and their slits (1)
A step of forming a meander in a zigzag manner so that the folds are positioned orthogonally to the center of the longitudinal direction of the step, and then inserting the flat tube (2) into the slit (1),
A method for manufacturing a heat exchanger core, comprising:

According to a second aspect of the present invention, in the first aspect, the non-cutting portion is partially left at the folding position.
Except for (3), a fold-back cutting part (4) is provided that cuts most of it, and the element part of the fin is placed between adjacent folds.
(5) was formed, a rising portion (6) was formed at the edge of the slit (1) along the longitudinal direction, and an expanded portion (7) for flat tube guide was formed at the center in the longitudinal direction. It is a manufacturing method of a heat exchanger core. According to the present invention of claim 3, in claim 2, the folded cut portion (4) is cut in a T-shape on both sides of the position of the non-cut portion (3), and a tongue-like shape is formed there. This is a method for manufacturing a heat exchanger core in which the connection portion (3a) remains.

According to a fourth aspect of the present invention, in the heat exchanger according to the third aspect, a dimple (10) for holding a gap is formed at the center of the tongue-shaped connecting portion (3a) in the direction of the folded back curve. It is a manufacturing method of a core. The present invention according to claim 5 provides
In Claims 2 to 4, the start-up part (6) is
This is a method of manufacturing a heat exchanger core that also serves as a spacer that specifies the interval between the facing element portions (5). The present invention according to claim 6 is the spacer part (8) according to any one of claims 2 to 5, wherein a space between the opposing element parts (5) is specified on both edges of the element part (5). Is a method for manufacturing a heat exchanger core in which the heat is cut or raised.

According to a seventh aspect of the present invention, in any one of the first to sixth aspects, the slits (1) are provided between the slits (1) and between the slits (1) and an edge of the strip-shaped metal plate. A method for manufacturing a heat exchanger core is provided with a louver group (9) formed by cutting and raising a large number of louvers (9a) spaced apart from each other, or with a large number of slits, small wavy bends and dimples. The present invention according to claim 8 is a heat exchanger core manufactured by the method according to any one of claims 1 to 7.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. 1 is an explanatory perspective view of a heat exchanger core of the present invention, FIG. 2 is an explanatory view showing a manufacturing process of the fin, and FIG. 3 is a developed state of the fin. Also,
FIG. 4 is an enlarged view of the IV portion, FIG. 5 is an enlarged horizontal cross-sectional view of an essential portion showing a state in which the element portions 5 are folded back in a zigzag shape, and FIG. 6 is a schematic vertical cross-sectional view of the louver group 9. As shown in FIG. 1, this heat exchanger core is formed by folding a thin strip metal plate into a fin to form a fin, and pressing a flat tube 2 into an elongated slit 1 formed in the width direction from one edge of the fin. is there.

In the step, a thin strip-shaped metal plate is press-molded as shown in FIGS. 3 and 4, and a large number of elongated slits 1 are formed.
Are formed at regular intervals in the width direction and the longitudinal direction, and the slits are formed so that the longitudinal direction thereof is parallel to the longitudinal direction of the strip-shaped metal plate. As shown in FIGS. 3 and 4, the shape of the slit 1 is such that circular expanding portions 7 and 7a are formed at both ends and a center of the longitudinal direction, and a pair of rising portions is formed between the expanding portions 7 and 7a. The part 6 is formed by bending.
The distance between the pair of opposing rising portions 6 is equal to that of the flat tube 2
Is formed to be slightly smaller than the thickness of. Then, at the position of the widened portion 7 of the slit 1, a narrow non-cutting portion 3 is slightly left on both edges of the strip-shaped metal plate, and the other portions are cut in the width direction to form a folded cut portion 4.

At the position of the non-cutting portion 3, the folding cut portion 4 is cut into a T-shape. Further, between the slits 1 and between the slits 1 and the edge of the strip-shaped metal plate, there are provided louver groups 9 formed by cutting and raising a large number of louvers 9a spaced apart from each other in the longitudinal direction. And louver groups 9 on both sides
Except for the above, a pair of spacer portions 8 are cut and formed at both ends in the longitudinal direction of the other louver group 9. The louver 9a
Instead of, a large number of slits, small wavy bent portions, dimples, or other heat exchange promoting means may be provided. Each of the spacer portions 8 is provided in a trapezoidal shape, has a first spacer 8a and a second spacer 8b, the first spacer 8a is formed wide and short, and the second spacer 8b is narrow and long. Is formed long. In the tongue-shaped connecting portion 3a, when the respective element portions 5 are bent and formed in a zigzag manner, the first spacer 8a and the second spacer 8b are in contact with each other as shown in FIG. Is specified.

Further, a dimple 10 as shown in FIGS. 15A and 15B can be formed on the bent top of the tongue-shaped connecting portion 3a. The dimple 10 has rigidity at the folded-back portion so as to specify the gap between the opposing element portions 5. That is, when the rigidity of the folded back bent portion is low, the tongue-shaped connecting portion 3a may be easily bent as shown in FIG. The dimple 10 is not a basic essential requirement. This is because the gap between the opposing element portions 5 can be specified by other means. The strip-shaped metal plate formed in this manner is sent to the downstream side of the arrow as shown in FIG. 2, compressed at the downstream side, and folded in a zigzag manner via the tongue-shaped connecting portion 3a.

The slits 1 of the respective element portions 5 thus folded are aligned with each other due to the presence of the tongue-shaped connecting portion 3a, and the flat tube 2 can be easily press-fitted therein. The flat tube 2 is press-fitted from the expanded portion 7 of the slit 1, and the rising portion 6 presses the flat surface of the flat tube 2. The rising portion 6 and the outer surface of the flat tube 2 can be joined by brazing. In addition, when brazing is performed, the tongue-shaped connecting portion 3a can be cut or removed thereafter. In that case, the air resistance on the fin side can be reduced.

In the actual manufacture of the fins, a strip-shaped metal plate is continuously press-formed, the fins are sequentially fed to the downstream side, and the fins are compressed and bent at the tongue-shaped connecting portion 3a.
When the required number of element parts 5 are counted, the tongue-shaped connection parts 3a are cut to form fins for one heat exchanger, and the fins can be kept in a focused state as a whole. Then, it suffices to insert the flat tubes 2 into the respective slits 1 as described above.

Next, FIGS. 7 to 9 show a second embodiment of the development view of the fins used in the heat exchanger core of the present invention. The difference of this example from that of FIGS. 3 and 4 is that Only the respective shapes of the rising portion 6, the expanding portion 7, and the spacer portion 8 are provided. First, as shown in FIGS. 8 and 9, the rising portions 6 are bent at their leading edges so that the leading edges of the adjacent element portions 5 come into contact with each other. At this time, the spacer portion 8 contacts the flat surface of the element portion 5. Also,
The expanding portion 7 is formed linearly as shown in FIG.

Next, FIGS. 10 to 11 are development views of other fins. In this example, in FIG. 7 to FIG. 9, the spacer portion 8 is not present and the expansion portion 7 is formed in a circular shape. It is a thing. The rising portion 6 also serves as the spacer portion 8. Then, as shown in FIG. 12, the edges of the rising portions 6 come into contact with the facing element portions 5 and form the spacers.

Next, FIGS. 13 to 14 are an enlarged view and a transverse cross-sectional view of a main part showing a developed state and an assembled state of yet another fin. In this example, a rising portion 6a having a low height and a rising portion 6 having a high height are erected on both sides of the slit 1,
The edge of the high rising portion 6 is bent.
The rising portion 6 also serves as a spacer for specifying the interval between the element portions 5 as shown in FIG.

[0020]

According to the method of manufacturing the heat exchanger core of the present invention, a large number of slits 1 are formed on the thin strip-shaped metal plate at regular intervals.
And the slit 1 is formed in a zigzag manner so that the folded portion is positioned at the center of the slit 1 in the longitudinal direction at right angles to the slit 1, the slits 1 can be reliably manufactured in an aligned state. The flat tubes 2 can be easily inserted into the respective slits 1, and a manufacturing method with high reliability and mass productivity can be provided.

Further, in the above structure, at the folding position,
A folded cut portion 4 that cuts most of the non-cut portion 3 is provided, a rising portion 6 is formed at the edge of the slit 1 along the longitudinal direction, and a flat tube guide expansion portion 7 is formed at the center in the longitudinal direction. Can be formed. With this configuration, both edges of each element portion 5 serve as cutting end surfaces, and the leading edge effect of the fluid can be formed there to enhance the heat exchange performance. The rising portion 6 of the slit 1 can improve the contact state between the flat tube 2 and the slit 1 and improve heat transfer between them. At the same time, the presence of the widened portion 7 of the slit 1 enables the flat tube 2 to be easily press-fitted into the slit 1, thereby improving mass productivity.

In the above structure, the folded cut portion 4 can be cut into a T-shape on both sides of the position of the non-cut portion 3, and the tongue-shaped connecting portion 3a can be left there. Thereby,
It is possible to increase the independence of the respective element portions 5 and to make the opposing surfaces parallel to each other. In the above structure, the dimples 10 for holding the gap can be formed at the center of the tongue-shaped connecting portion 3a in the folding and bending direction. Thereby, the interval between the opposing element portions 5 can be specified. Further, in the above structure, the rising portion 6 can also serve as a spacer for specifying the interval between the element portions 5 facing each other. As a result, it becomes possible to make the intervals of the element portions 5 exactly parallel.

In any of the above configurations, the spacer portions 8 for specifying the intervals between the element portions 5 facing both edges of the element portion 5 can be cut and raised or formed so as to project. As a result, it is possible to accurately maintain the distance between the element portions 5. In any of the above configurations, a louver group 9 formed by cutting and raising a large number of louvers 9a can be provided between the slits 1 and between the slits 1 and the strip-shaped metal plate in the longitudinal direction thereof so as to be spaced apart from each other. Thereby, for the fluid flowing parallel to the flat tube 2,
The heat exchange performance can be improved by dividing the boundary layer on the surface of the element portion 5. The heat exchanger core manufactured by any of the above methods has high reliability and mass productivity.

[Brief description of drawings]

1 is a schematic explanatory perspective view of a method for manufacturing a heat exchanger core of the present invention.

FIG. 2 is an explanatory view showing a method for manufacturing fins used in the heat exchanger core.

FIG. 3 is a plan view showing a developed state of the fin.

FIG. 4 is an enlarged view of a main part of the fin.

FIG. 5 is a cross-sectional view of a main part showing an assembled state of the fin.

FIG. 6 is a schematic vertical sectional view of a louver group 9 of the fin.

FIG. 7 is a plan view showing a developed state of another fin used in the heat exchanger core.

FIG. 8 is an enlarged view of a main part of the fin.

FIG. 9 is a transverse cross-sectional view of a main part showing an assembled state of the fin.

FIG. 10 is a plan view showing a developed state of another fin used in the heat exchanger core.

FIG. 11 is an enlarged view of a main part of the fin.

FIG. 12 is a transverse cross-sectional view of a main part showing an assembled state of the fin.

FIG. 13 is an enlarged view of a main part of still another fin used in the heat exchanger core.

FIG. 14 is a lateral cross-sectional view of a main part showing an assembled state of the fin.

FIG. 15 is a perspective view and a front view showing another example of the tongue-shaped connecting portion 3a of the other fin.

16 is an explanatory diagram of a defect in the case where there is no dimple in FIG.

[Explanation of symbols]

1 slit 2 Flat tube 3 Non-cutting part 3a Tongue-shaped connection part 4 Folded cutting part 5 Element part 6 startup section 6a Startup section 7,7a Expansion part 8 Spacer 8a First spacer 8b Second spacer 9 louvers 9a louver 10 dimples

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yutaka Urano             3-25-3 Yoyogi, Shibuya-ku, Tokyo Toyo             Inside Radiator Co., Ltd. F-term (reference) 3C030 CA03

Claims (8)

[Claims] 1. A thin strip-shaped metal plate is formed with a large number of slits (1) elongated in the longitudinal direction thereof at regular intervals, and a fold is positioned at the center of the slit (1) in the longitudinal direction so as to be orthogonal to it. A method for manufacturing a heat exchanger core, comprising: a step of forming a zigzag bend, and a step of inserting a flat tube (2) into the slit (1). 2. The folded cut section (4) according to claim 1, wherein the folded position is provided with a folded cut section (4) for cutting most of the non-cut section (3) which is partially left,
A fin element part (5) is formed between adjacent turns, and a rising part is formed at the edge of the slit (1) along the longitudinal direction.
A method for manufacturing a heat exchanger core, wherein (6) is formed, and an expanded portion (7) for a flat tube guide is formed at the center in the longitudinal direction. 3. The cut-back portion (4) according to claim 2, wherein the folded-back cutting portion (4) is cut in a T shape at both sides of the position of the non-cutting portion (3), and the tongue-like connecting portion (3a) is cut there. Of the heat exchanger core in which the heat is left. 4. The method for manufacturing a heat exchanger core according to claim 3, wherein a dimple (10) for maintaining a gap is formed in the center of the tongue-shaped connecting portion (3a) in the folding curve direction. 5. The method for manufacturing a heat exchanger core according to claim 2, wherein the rising portion (6) also serves as a spacer that specifies a distance between the facing element portions (5). 6. The element portion according to any one of claims 2 to 5, wherein the element portion (5) faces both edges of the element portion (5).
A method for manufacturing a heat exchanger core, in which a spacer portion (8) for specifying the interval of (5) is cut and raised or formed in a protruding manner. 7. The louver according to claim 1, wherein a plurality of louvers are spaced apart from each other in the longitudinal direction between the slits (1) and between the slits (1) and the edge of the strip-shaped metal plate. A method for manufacturing a heat exchanger core provided with a louver group (9) formed by cutting and raising (9a) or provided with a large number of slits, small wavy bent portions, and dimples. 8. A heat exchanger core manufactured by the method according to claim 1.