JP2002028741A - Louver fin, manufacturing method thereof, and heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a louver fin which can ensure the excellent heat transfer characteristic and improve the drainability of the condensate when the louver fin is used as an outer fin for, for example, an evaporator, and a manufacturing method thereof, and a heat exchanger using the louver fin. SOLUTION: In this fin 1, a ridge surface 3 and a valley bottom surface 4 are formed flat, each louver 2 is formed to a boundary area of ridge and valley flat surfaces, and a ventilation space 5 between adjacent louvers 2 is formed to a boundary area of the ridge and valley flat areas 3 and 4, and the surface direction of each louver 2 is not parallel to the axial direction X of the ridge and valley flat surface. In this heat exchanger, the fin 1 is arranged between tubes, and the line connecting middle points in the width direction of the louver forms an angle with respect to the wind direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a louver fin excellent in heat transfer characteristics used for a heat exchanger such as an evaporator and a condenser, a method of manufacturing the louver fin, and a heat exchanger using the louver fin.

[0002]

2. Description of the Related Art In an evaporator or a condenser, for example, a refrigerant flowing in a tube exchanges heat with air flowing in an air flow gap including a corrugated fin interposed between the tubes. It has been done.

As a fin (100) used in such a heat exchanger such as an evaporator or a condenser, for example, a sheet material such as an aluminum sheet as shown in FIG. A configuration in which a plurality of louvers (102)... Are cut and raised on a surface is known. Since air flows between the louvers (102), the heat exchange efficiency between the flowing air and the refrigerant is improved.

[0004]

However, the louver fin having the above-mentioned conventional structure has the following problems.
That is, the portion (101) where the louver is not cut and raised on the erected side surface of the fin is present at an angle with the cut and raised louver surface (102),
As a result, there is a problem that the heat transfer characteristics are reduced.
Further, when the louver fin having the conventional configuration is used as an outer fin for an evaporator, there is a problem that condensed water generated on the surface tends to accumulate in the portion (101) where the louver is not cut and raised. Was. Further, when the fin pitch is large, there is a problem that the amount of air flowing out without passing between the louvers (102) is significantly increased, and the heat transfer characteristics are further reduced.

The present invention has been made in view of such a technical background, and can ensure excellent heat transfer characteristics. For example, when used as an outer fin for an evaporator, drainage of condensed water is prevented. It is an object of the present invention to provide a louver fin capable of improving the temperature, a method of manufacturing the same, and a heat exchanger using the same.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a louver fin having a metal sheet made of aluminum or the like formed in a meandering shape by performing a predetermined bending operation on the metal sheet made of aluminum or the like so that the fins of the fins are bent. The surface and the valley bottom are formed in a flat surface, each louver is formed up to the boundary region with the valley flat surface, and a ventilation gap between adjacent louvers is formed up to the boundary region with the valley flat surface, and The louver fin is characterized in that the plane direction of the louver is non-parallel to the axial direction of the flat valley surface.

[0007] Since the ventilation gap between the adjacent louvers is formed up to the boundary area with the flat surface of the valley, the heat transfer characteristics are excellent. In addition, there is no portion other than the louver on the erected side surface of the fin, and there is no portion in which the louver is not cut and raised as in the conventional fin.For example, when used as an outer fin for an evaporator, condensation occurs. There is no portion where water accumulates, and condensed water is excellent in drainage.

The plane directions of the louvers are parallel to each other, the midpoints in the width direction of the louvers are aligned on a straight line, and the straight line connecting the midpoints extends in the axial direction of the flat valley plane. Preferably, it is configured so as to be parallel to the surface. With such a configuration, it is possible to further improve the heat transfer characteristics while further reducing the ventilation resistance.

It is preferable that the straight line connecting the midpoints of the louvers in the width direction is not orthogonal to the front line of the fin. With such a configuration, when the heat exchanger is manufactured, it is possible to configure the straight line connecting the midpoints of the louvers in the width direction to have an angle with respect to the flow direction of the wind. And an excellent heat exchanger can be provided.

The louver fin having the above structure can be manufactured with high manufacturing efficiency and low cost by the following manufacturing method. That is, in the method of manufacturing a louver fin according to the present invention, a plurality of folded band portions serving as a ridge top surface or a valley bottom surface of the fin are arranged in parallel with each other at a predetermined interval in the sheet length direction, and between the folded band portions. A plurality of louvers were formed in parallel with each other between the folded band portions by providing a plurality of slits in a region in a non-orthogonal direction to the axis direction of the folded band portion. A metal sheet such as aluminum is prepared, and the louver is bent in a mountain fold or a valley fold with respect to the folded band along a folding line that is non-parallel to the axial direction of the folded band, thereby forming the metal sheet. Is formed in a meandering shape in which the folded band portions alternately become a peak or a valley bottom.

A louver fin having the above structure can be manufactured simply by forming a plurality of slits in a metal sheet in advance to form a louver portion, and bending the louver in a mountain fold or a valley fold with respect to a folded band portion. In addition, since there is no need to perform the operation of raising the louver in the cutting and raising operation as in the related art, the production efficiency is excellent and the cost is low. Further, when the louver is bent with respect to the folded band portion, since the louver is bent along a folded line which is non-parallel to the axial direction of the folded band portion, the surface direction of each louver in the obtained fin is a flat surface of the mountain valley. Becomes non-parallel to the axial direction.

Preferably, a hole is formed in the metal sheet at an intermediate portion of the folded line. Due to the formation of the holes in the folded lines, the bending operation is very easy, and the louver fins of excellent quality can be provided because the folded lines can be reliably bent at the desired folded lines.

The angle θx between the folding line in the metal sheet and the axial direction of the folding strip is preferably in the following range. When the angle θx is in such a range, the heat transfer characteristics can be further improved.

Tan ⁻¹ (1.01 × t / Lp) ≦ θx ≦ 45 ° (t: louver thickness, Lp: louver pitch)

In the heat exchanger of the present invention, a plurality of heat exchange tubes are connected to the hollow header in a communicating state,
In the heat exchanger in which the louver fins are disposed between these tubes, the louver fins having the above-described configuration are used as the louver fins, and an angle θy between a straight line connecting the midpoint in the width direction of the louver and the flow direction of the wind. Are arranged in the following range.

-90 ° ≦ θy ≦ 90 ° (θy ≠ 0 °)

Since the louver fin having the above structure is used, the louver fin has excellent heat transfer characteristics. Furthermore, since the straight line connecting the midpoints in the width direction of the louvers is arranged so as to have the above angle θy with respect to the flow direction of the wind, even when the fin pitch is large, the wind passes between the louvers. It is possible to effectively prevent the gas from passing through without passing through, and to further improve the heat transfer characteristics.

When the following relationship is established between the angle θx between the plane direction of the louver and the axis direction of the flat surface of the mountain and the valley, the heat transfer characteristic is further improved while the ventilation resistance is further reduced. Can be.

0 ° ≦ θx + θy ≦ 45 °

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1 showing a louver fin (1) according to an embodiment of the present invention, (2) is a louver, (3) is a top of the fin, (4) is a bottom of the fin, (5) is a ventilation gap formed between the louvers.

The louver fin (1) is a louver fin used for a heat exchanger such as an evaporator and a condenser.
FIG. 3 is a view showing a state where a metal sheet (10) made of aluminum or the like is formed by performing a predetermined bending operation.
As shown in (1), all of the fin top (3), valley bottom (4) and side louvers (2) of the fin are formed in a flat surface, and each bent portion is formed into a meandering shape by bending. ing. That is, the louver (2) on the side surface is bent at right angles to both the crest surface (3) and the valley bottom surface (4) arranged in parallel between the upper and lower sides. Each of the louvers (2) is formed up to the boundary region between the peak surface (3) and the valley bottom surface (4), whereby a ventilation gap (5) formed between the adjacent louvers (2) is formed. It is formed up to the boundary region between the surface (3) and the valley bottom surface (4) (see FIG. 1). Since the ventilation gap (5) is formed up to the boundary region between the flat surfaces (3) and (4), the heat transfer characteristics can be excellent.

Further, each bent portion is formed in a right angle, and a louver (2) on the side surface is suspended from both the crest surface (3) and the valley bottom surface (4). There is no portion other than the louver, and there is no portion where the louver is not cut and raised, such as a conventional fin, on the side surface.For example, even when used as an outer fin for an evaporator, condensed water does not collect. Therefore, the drainage of the condensed water can be made excellent.

The plane direction of each louver (2) is non-parallel to the axial direction (X) of the flat surface (3) (4). Further, as shown in FIG. 2, the plane direction of each louver (2) is parallel to each other, and the midpoint (P) in the width direction of each louver (2) is aligned on a straight line. In addition, since the straight line (Q) connecting the midpoint (P) is configured to be parallel to the axial direction (X) of the flat surfaces (3) and (4), the ventilation resistance is suppressed. Further, the heat transfer characteristics can be further improved.

In this embodiment, the line (R) connecting the opposing side end faces (8) of the adjacent louvers (2) is substantially in the plane direction (S) of the louver (2). It is configured so as to be orthogonal or orthogonal, so that the heat transfer characteristics can be further improved while suppressing the ventilation resistance.

Further, in the present embodiment, the straight line (Q) connecting the midpoint (P) in the width direction of the louver (2) is configured not to be orthogonal to the front line (K) of the louver fin (1). When the heat exchanger (20) is manufactured using the louver fins (1), the straight line (Q) connecting the midpoint (P) in the width direction of the louver (2) is defined by the wind flow direction ( J) can be configured to have an angle with respect to
As a result, a heat exchanger (20) having excellent heat transfer characteristics can be manufactured.

The method for producing the louver fin (1) of the present invention is not particularly limited, but the following production method is preferred.

First, a metal sheet (10) made of aluminum or the like as shown in FIG. 4 is prepared. This sheet (10)
Is arranged such that a plurality of folded strips (11) serving as ridge tops (3) or valley bottoms (4) of the fins are arranged parallel to each other at predetermined intervals in the sheet length direction and inclined with respect to the sheet width direction. A plurality of slits (12) are provided in a region between the folded band portions (11) in a direction non-perpendicular to the axial direction (X) of the folded band portion (11). A plurality of louvers (2) for connecting them are formed in parallel between the strips (11).

The means for forming the slit as described above is not particularly limited, and examples thereof include a chemical etching method and an electric discharge machining method.

The width of the slit (12) is not particularly limited, and may have a predetermined slit width (m) as in the present embodiment, or may have a predetermined slit width (m).
May be substantially absent, that is, a form in which a cut is simply made.

The angle between the axis of the slit (12) and the axis (X) of the folded band (11) is 45 ° to 45 °.
It is preferable to set 90 ° -tan ⁻¹ (1.01 × t / Lp), since the heat transfer characteristics can be further improved while suppressing the ventilation resistance.

(13) is a folded line, and the folded line (13) is non-parallel to the axial direction (X) of the folded band (11). In this embodiment, the folded line is (13) is a line orthogonal to the axial direction of the louver (2). In addition, one hole (14) is formed at the center in the length direction of the folding line (13). In addition, this hole (1
The shape of 4) is not particularly limited, and may be any shape such as a circle, an ellipse, and a rectangle. Also,
The number of the holes (14) to be provided is not particularly limited. However, if the occupation ratio of the holes (14) in the length direction of the folding line (13) increases, the strength of the bent portion cannot be sufficiently ensured, and Fins (1)
It is not preferable to increase the amount more than necessary, since the product strength is lowered and the durability is lowered.

Then, the louver (2) is bent in a mountain fold or a valley fold at right angles to the folded band (11) along the folded line (13), and the metal sheet (10) is bent.
Is formed into a right-angled meandering shape in which the folded band portions (11) alternately become a peak (3) and a valley (4) to obtain a louver fin (1) shown in FIG. At this time, since the hole (14) is formed at the center in the length direction of the folding line (13), the bending operation becomes very easy, and the desired folding line (1) is formed.
Since the louver fin (1) excellent in quality can be provided because the louver fin (1) can be reliably bent in (3).

The bending operation can be performed by, for example, a conventionally known gear meshing method, but is not particularly limited to this method.

The angle .theta.x between the folding line (13) of the metal sheet (10) and the axial direction (X) of the folding band (11) is set in the following range, which further improves the heat transfer characteristics. It is preferable in that it can be performed.

Tan ⁻¹ (1.01 × t / Lp) ≦ θx ≦ 45 ° (t: louver thickness, Lp: louver pitch)

The metal sheet (10) includes:
For example, an aluminum sheet, an aluminum alloy sheet, an aluminum brazing sheet clad with a brazing material layer, or the like is used.

Next, FIG. 5 shows a heat exchanger (20) according to one embodiment of the present invention. The heat exchanger (20) is, for example, a condenser used in a refrigeration cycle for a car cooler, and has flat tubes (22) and the louver fins (1) arranged alternately in a vertical direction.
(25) (25) is a pair of left and right headers connected to both ends of the flat tube (22) in a communicating state.

The flat tube (22) is a so-called harmonica tube which is made of an extruded aluminum material and is internally partitioned into a plurality of chambers by partition walls to improve heat transfer performance and pressure resistance. In addition, as the flat tube (22), a tube made of an electric resistance welded tube can also be used. The header (25), in which the louver fins (1) are interposed between the flat tubes (22), (22), is used to bring the aluminum brazing sheet clad with the brazing material layer into an abutting state on both side edges. The header pipe (25 a) is formed into a pipe shape by bending, and an aluminum lid (25 b) for closing the opening at both ends of the header pipe (25 a) in an outer fitting state.

On the peripheral side walls of the headers (25) and (25), tube insertion holes (30) are provided at predetermined intervals along the length direction thereof.
0) are inserted and connected to both ends of each tube (22).

A refrigerant inlet pipe (26) is connected to the upper outside of the right header (25), and a refrigerant outlet pipe (27) is connected to the lower outside of the right header (25). Each of the left and right headers (25) (25) is provided with a partition plate (28) for partitioning in the longitudinal direction thereof, and the refrigerant flowing from the refrigerant inlet pipe (26) into the right header (25) is a tube group. Flows in a meandering manner around all the refrigerant flow passages formed by the above and flows out of the refrigerant outlet pipe (27), and in the meantime, flows through the air flow gap including the louver fins (1) formed between the tubes (22). It exchanges heat with and condenses. In addition,
(29) is a side plate arranged outside the outermost fin (1).

In this construction, the front line (K) of the louver fin (1) is arranged so as to be parallel to the front line (M) of the flat tube (22), so that it is shown in FIG. The straight line (Q) connecting the midpoint (P) of the louver (2) in the width direction has an angle θy with respect to the wind flow direction (J) (the width direction of the tube). Therefore, even when the fin pitch is small, as well as when the fin pitch is large, it is possible to effectively prevent the wind from passing through the louvers (2) without passing through the louvers (2). Can be improved.

The following relationship is established between the angle θx between the plane direction (S) of the louver (2) and the axial direction (X) of the flat valleys (3) and (4), and the angle θy. It is preferred to employ This makes it possible to further improve the heat transfer characteristics while reducing the ventilation resistance.

0 ° ≦ θx + θy ≦ 45 °

[0044]

According to the louver fin of the present invention, since the ventilation gap between the adjacent louvers is formed up to the boundary region with the flat surface of the valley, the louver fin has excellent heat transfer characteristics. In addition, since the erected fins are all louvers and there are no parts where the louvers are not cut and raised as in the prior art, for example, when used as an outer fin for an evaporator, there is no part where condensed water accumulates. It is excellent in drainage of water.

The plane directions of the louvers are parallel to each other, the midpoint in the width direction of each louver is aligned, and the straight line connecting the midpoints is the axial direction of the flat valley plane. When it is configured so as to be parallel with respect to, the heat transfer characteristics can be further improved while reducing the ventilation resistance.

When the straight line connecting the midpoints of the louvers in the width direction is not perpendicular to the front line of the fin, the midpoints of the louvers in the width direction are connected when the heat exchanger is manufactured. It is possible to configure the straight line so as to have an angle with respect to the flow direction of the wind, so that the heat transfer characteristics of the heat exchanger can be improved.

According to the louver fin manufacturing method of the present invention, a plurality of slits are provided in advance in the metal sheet to form a louver portion, and the louver is formed into a mountain fold or a valley fold with respect to the folded band. It can be manufactured only by bending, and it is not necessary to perform the operation of raising the louver in the cutting and raising operation as in the related art, so that the production efficiency is excellent and the cost is low. Also, when bending, it is folded along the folding line that is non-parallel to the axis direction of the folded band, so that the surface direction of each louver in the obtained fin is non-parallel to the axis direction of the flat valley plane Can be made.

When a hole is formed in the middle of the folded line of the metal sheet, the bending operation can be performed very easily, and the metal sheet can be reliably bent at a desired folded line. There is an advantage that quality products can be manufactured.

The angle θx between the folding line in the metal sheet and the axial direction of the folding band is tan ⁻¹ (1.01 ×
When the condition of (t / Lp) ≦ θx ≦ 45 ° is satisfied, the heat transfer characteristics can be further improved.

The heat exchanger of the present invention has excellent heat transfer characteristics because the louver fins having the above structure are used. Furthermore, the angle θy between the straight line connecting the midpoints of the louvers in the width direction and the flow direction of the wind is −90 ° ≦ θy ≦ 90 °
(Θy ≠ 0 °), so that even when the fin pitch is large, it is possible to effectively prevent the wind from passing without passing between the louvers. As a result, the heat transfer characteristics can be further improved.

0 ° ≦ θx + between the angle θy between the plane direction of the louver and the axial direction of the flat surface of the mountain valley and the angle θy.
When the relationship of θy ≦ 45 ° holds, the heat transfer characteristics can be further improved while reducing the ventilation resistance.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a louver fin according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA in FIG.

FIG. 3 is a front end view of the louver fin.

FIG. 4 is a plan view showing a metal sheet before bending.

FIG. 5 is a perspective view showing a heat exchanger according to one embodiment of the present invention.

FIG. 6 is a sectional view taken along line BB in FIG. 5;

FIG. 7 is a perspective view showing a conventional louver fin.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Louver fin 2 ... Louver 3 ... Crest surface 4 ... Valley bottom 5 ... Ventilation gap 10 ... Metal sheet 11 ... Folded band part 12 ... Slit 13 ... Folded line 14 ... Hole J ... Wind flow direction K ... Front of louver fin Line P: Midpoint in the width direction of the louver Q: Straight line connecting the midpoints R: Line connecting the side end faces S: Surface direction of the louver W: Front line of the louver fin X: Axial direction of the flat surface of the valley

Claims (8)

[Claims] 1. A plurality of folded strips serving as crests or valley bottoms of fins are arranged in parallel with each other at predetermined intervals in a sheet length direction, and the folded strips are provided in a region between the folded strips. A metal sheet made of aluminum or the like in which a plurality of louvers are formed in parallel in a manner in which a plurality of slits are provided in a non-orthogonal direction with respect to the axial direction so as to connect them between the folded band portions is prepared. By folding the louver in a mountain fold or a valley fold with respect to the folded band along a folded line that is non-parallel to the axial direction of the folded band, the folded band of the metal sheet alternates. A method for producing a louver fin, wherein the louver fin is formed into a meandering shape that becomes a peak or a valley bottom. 2. The method for manufacturing a louver fin according to claim 1, wherein a hole is formed in an intermediate portion of the folded line of the metal sheet. 3. The method of manufacturing a louver fin according to claim 1, wherein an angle θx between a folding line in the metal sheet and an axial direction of the folding band portion is in the following range. tan ⁻¹ (1.01 × t / Lp) ≦ θx ≦ 45 ° (t: louver thickness, Lp: louver pitch) 4. A louver fin having a metal sheet made of aluminum or the like formed in a meandering shape, wherein the metal sheet made of aluminum or the like is subjected to a predetermined bending operation so that the tops and bottoms of the fins become flat. Each louver is formed up to the boundary region with the flat valley surface, the ventilation gap between the adjacent louvers is formed up to the boundary region with the flat valley surface, and the plane direction of each louver is flat. A louver fin characterized by being non-parallel to the axial direction of the surface. 5. A plane direction of each of the louvers is parallel to each other, and a midpoint in a width direction of each louver is aligned on a straight line, and a straight line connecting the midpoints is a flat mountain-valley surface. The louver fin according to claim 4, wherein the louver fin is configured to be parallel to the axial direction of the louver fin. 6. The louver fin according to claim 5, wherein a straight line connecting midpoints in the width direction of the louver is not orthogonal to a front line of the fin. 7. A heat exchanger in which a plurality of heat exchange tubes are connected to a hollow header in a communicating state, and louver fins are disposed between the tubes, wherein the louver fins are used as the louver fins. The angle θy between the straight line connecting the midpoint in the width direction of the louver and the flow direction of the wind in which the louver fin according to item 1 is used
Is arranged so as to be in the following range. -90 ° ≦ θy ≦ 90 ° (θy ≠ 0 °) 8. The heat exchanger according to claim 7, wherein the following relationship is established between an angle θx formed by a plane direction of the louver and an axial direction of the flat surface of the valley and the angle θy. 0 ° ≦ θx + θy ≦ 45 °