JPH07265985A - Manufacture of heat exchanger provided with inner fins - Google Patents

Abstract

PURPOSE:To obtain a heat exchanging tube having stickiness between a flat tube and inner fins by arranging the grooves extending in the length direction on the side walls at the right and the left sides of the flat tube and crushing these parts. CONSTITUTION:The flat tube 1 provided with flat upper and lower walls 3 and the right side and the left side walls 4 having the grooves 5 extending in the length direction at the middle part on the inner surface is prepared. The inner fins 2 are inserted into this flat tube, and the flat tube including the inner fins is pressure-formed by roll-forming or press-forming. The thin wall part 4a of the side walls 4 at the right and the left sides are plastic- deformed and the opposite walls 5 to the groove become mutually in close contact to eliminate the grooves 5. The plastic deformation is concentrated in the thin part 4a of the right and the left side walls 5, thus, the heat exchanging tube, small in spring back, good in stickiness between the inner fins 2 and the upper and the lower walls 3 is obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a heat exchange tube having inner fins.

[0002]

2. Description of the Related Art Conventionally, as a method of manufacturing a heat exchange tube containing an inner fin, the inner fin is inserted into a flat tube having flat upper and lower walls and left and right side walls having a substantially arcuate cross section,
It is known that the flat tube containing the inner fins is pressed from both upper and lower sides to bring the inner fins into close contact with the upper and lower walls.

[0003]

In the above manufacturing method,
There is a problem that poor adhesion between the flat tube and the inner fin is likely to occur.

An object of the present invention is to provide a method of manufacturing a heat exchange tube having an inner fin, in which poor adhesion between the flat tube and the inner fin is unlikely to occur.

[0005]

A method for manufacturing a heat exchange tube having inner fins according to a first aspect of the present invention is a flat tube having upper and lower walls and left and right side walls having grooves extending in the longitudinal direction in the middle of the inner surface. The inner fin is inserted into the flat tube, and the flat tube with the inner fin is pressed from both the upper and lower sides to eliminate the grooves on the left and right side walls and to bring the inner fin and the upper and lower walls into close contact with each other. Is.

In the method of manufacturing a heat exchange tube having inner fins according to the second aspect of the present invention, a flat tube having upper and lower walls and left and right side walls each having a substantially arcuate cross section is prepared, and the left and right edges of the inner fin are flattened. Forming bent edges along the inner surface of the left and right side walls of the pipe,
Insert the inner fin into the flat tube, pressurize the flat tube with the inner fin from both the upper and lower sides, and bring the left and right side walls of the flat tube into close contact with the left and right bent edges of the inner fin. It is characterized by closely contacting the wall.

[0007]

According to the method of manufacturing a heat exchange tube having inner fins of the first invention, a flat tube having upper and lower walls and left and right side walls having a groove extending in the longitudinal direction in the middle of the inner surface is prepared. Inner fins are inserted into the flat tube, and the flat tube with inner fins is pressed from the upper and lower sides to eliminate the grooves on the left and right side walls, and the inner fin and the upper and lower walls are in close contact with each other. The spring back becomes smaller, and the inner fin and the upper and lower walls are closely attached.

According to the method for manufacturing a heat exchange tube having inner fins of the second invention, a flat tube having upper and lower walls and left and right side walls each having a substantially arcuate cross section is prepared, and the left and right edges of the inner fin are provided. Forming bent edges along the inner surfaces of the left and right side walls of the flat tube, insert this inner fin into the flat tube, press the flat tube with inner fins from the upper and lower sides, and Since the inner fins and the upper and lower walls are in close contact with each other while the left and right folding edges are in close contact, not only the inner fins and the upper and lower walls are in close contact, but also the left and right side walls of the flat tube and the inner fins are both folded. It also adheres to the bent edge.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. In this specification, "aluminum" includes an aluminum alloy.

The method according to the first invention will be described with reference to FIGS.

First, a flat pipe (1) made of extruded aluminum is prepared, which has flat upper and lower walls (3) and left and right side walls (4) having a groove (5) extending in the longitudinal direction in the middle of the inner surface. . The left and right side walls (4) are thicker than the upper and lower walls (3), and the central portion thereof, that is, the portion corresponding to the bottom wall (5a) of the groove (5) is a thin portion (4a). The left and right side walls (4) have an outer surface having a semicircular cross section, the groove (5) has a substantially U-shaped cross section, and the bottom wall (5a) has a semicircular cross section having an outward convex shape. .

Next, an aluminum inner fin (2) is inserted into the flat tube (1). Inner fin
For (2), multi-entry fins are used. To make it easier to insert the inner fin (2),
As shown in, the space between the upper and lower walls (3) is
There is a gap between the upper wall (3) of the flat tube (1) in which the inner fin (2) is inserted and the inner fin (2), which is larger than the height of (4) and serves as a crushing allowance (6). Has occurred. Left and right side walls
The distance between the opposing walls (5b) of the groove (5) of (4) is the crushing allowance (6).
Equal to.

Finally, the flat tube (1) containing the inner fins (2) is pressed from both upper and lower sides by a roll forming device. Then, the thin wall portions (4a) of the left and right side walls (4) are plastically deformed, the opposing walls (5b) of the groove (5) are in close contact with each other, and the groove (5) is eliminated, and the upper and lower walls of the flat tube (1) are removed. (3) and inner fin
(2) and (2) are in close contact with each other, and the heat exchange tube having the inner fins (2) shown in FIG. 3 is manufactured.

In the conventional manufacturing method, since the left and right side walls having a substantially semicircular cross section are uniformly deformed during pressurization, the amount of deformation strain is small, and therefore the springback is large, and the degree of adhesion between the flat tube and the inner fin is large. However, in the manufacturing method according to the present invention, the deformation is
Since it concentrates on the thin wall part (4a) of (4) and causes plastic deformation, the springback is small and therefore the inner fin
A heat exchange tube with good adhesion between (2) and the upper and lower walls (3) can be obtained.

To press-mold the flat tube with the inner fins, not only roll molding but also press molding can be used. Due to the plastic deformation of the thin wall portions (4a) of the left and right side walls (4), the width of the heat exchange tube becomes slightly wider than that of the flat tube (1) before pressurization. Further, the outer surfaces of the left and right side walls (4) have a semi-circular cross-section, and their radii become slightly smaller.

In the above embodiment, the groove (5) has a substantially U-shaped cross section, and the bottom wall (5a) has a semicircular shape with an outwardly convex shape. It can be changed as appropriate as long as it can plastically deform the left and right sidewalls when pressure is applied.
For example, the opposing wall may be tapered so that the groove (5) has a substantially V-shaped cross section, and the bottom wall has a semicircular shape with an outwardly convex shape. Further, the shape of the bottom wall may be an arc shape other than a semicircle, or may be an acute angle shape instead of the arc shape. Also, the distance between the opposing walls (5b) of the grooves (5) on the left and right side walls (4) should be
It need not be exactly equal to (6). Also, the left and right side walls
(4) is not limited to that in the above embodiment, and the outer surface of the left and right side walls (4) may have an acute angle so that the flat tube can be easily crushed.

As the inner fin (2) to be inserted into the flat tube (1), a wave fin (10) as shown in FIG. 4 is used in addition to the above-mentioned multi-entry fin. The wave fins (10) are peaks along the fluid flow direction.
Wavy fin element in which (12) and trough (13) are repeated
(11) has a shape in which adjacent ones are connected in parallel so that the phases thereof are shifted by 180 degrees, and the fluid is a peak portion (12) and a valley portion (13) of the adjacent wavy fin elements (11). ) And can flow in the width direction.

In the above, since the inner fins (2) and (10) inserted into the flat tube (1) each have a flow passage in the width direction, the fluid is mixed in the heat exchange tube. As a result, the heat exchange performance of the heat exchange tube provided with these inner fins (2) (10) is improved.

The heat exchange tube manufactured in this manner is suitable for a refrigerant condensing tube of an aluminum multiflow type condenser, and in addition, an oil cooler,
Also used as radiators, car cooler evaporation tubes, etc.

5 to 9 show a large number of protrusions (23) (3
3) (43) (53) (63) flat plate part (22) (32) (42) (52) (6
2) and flat plate parts (22) (32) (42) (52) (62) bent edge parts (24) (25) (34) (35) (44) (45) provided on both left and right edges (54) (55) (64) (6
Inner fins (21) (31) (41) (51) (61) consisting of 5) are shown.

These inner fins (21) (31) (41) (51)
In order to manufacture a heat exchange tube having (61), inner fins (21) (31) ( 41) (51) (61)
Insert the inner fin (21) (31) (41) (51) (61) into the inner fin (21)
(31) (41) (51) (61) and the upper and lower walls are in close contact with each other.

A belt-shaped inner fin consisting only of a flat plate portion provided with a large number of protrusions has been known in the past, but this belt-shaped inner fin has an advantage that it has a flow passage in the width direction. However, there is a problem that the strength in the length direction is low and the inner fin is deformed during insertion into the flat tube.

The inner fin (2 shown in FIGS. 5 to 9)
1) (31) (41) (51) (61) are all flat plate parts (22) (32) (42) (52)
(62) Bend to both left and right edges (24) (25) (34) (35) (44) (45) (5
4), (55), (64) and (65) are provided, and therefore, the strength in the length direction is large and the insertion work into the flat tube is easy.

The inner fin (21) of FIG. 5 has a flat plate portion (22) provided with a large number of hemispherical projections (23) projecting upward or downward, and folding pieces provided on both edges of the flat plate portion (22). Curved edge (24)
It consists of (25). Left and right bent edges (24) (25) are flat plate (22)
The left and right folding edges (24) and (25) are bent in directions opposite to each other.

The inner fin (31) of FIG. 6 has a large number of semi-circular cut-and-raised protrusions (33) cut or raised upward or downward.
The flat plate part (32) is provided with bent edge parts (34) and (35) provided on both edges of the flat plate part (32). Left and right folding edges (34)
The reference numeral (35) is bent so as to be perpendicular to the flat plate portion (32), and the left and right bent edges (34) and (35) are bent in mutually opposite directions.

The inner fin (41) of FIG. 7 has a large number of triangular cut-and-raised protrusions (43) cut or raised upward or downward.
And a bent edge portion (44) (45) provided on both edges of the flat plate portion (42). Left and right bent edges (44)
The reference numeral (45) is bent so as to be perpendicular to the flat plate portion (42), and the left and right folding edge portions (44) and (45) are bent in mutually opposite directions.

The inner fin (51) of FIG. 8 has a large number of triangular cut-and-raised protrusions (53) cut or raised upward or downward.
The flat plate part (52) is provided with bent edge parts (54) and (55) provided on both edges of the flat plate part (52). Left and right bent edges (54)
Each of the (55) is divided into a plurality of pieces, and is bent so as to be perpendicular to the flat plate portion (52) and alternate upward and downward. The divided parts of the left bent edge portion (54) and the right bent edge portion (55) that face each other are bent in opposite directions.

The inner fin (61) of FIG. 9 has a large number of triangular cut-and-raised protrusions (63) cut or raised upward or downward.
And a bent edge portion (64) (65) provided on both edges of the flat plate portion (62). Left and right folding edges (64)
The reference numeral (65) is bent so as to be perpendicular to the flat plate portion (62), and the left and right bent edges (64) and (65) are bent in opposite directions.

FIG. 10 shows various modifications of the left and right bent edges. What is shown in FIG. 5A is the same as that in FIG. 5, and what is shown in FIG. 5B is that the left and right folding edge portions 70 and 71 are bent in the same direction. .
Compared to the one shown in (A), the left and right bent edges (72) and (73) of the one shown in (C) are not vertically bent but curled. The one shown in (D) is different from the one shown in (B) in that the left and right bent edges (74) and (75) are not curled vertically but curled. What is shown in (E) is the same as that shown in FIG. Compared with the one shown in (E), the left and right bent edges (76) and (77) of the one shown in (F) are not vertically bent but curled in an arcuate cross section.

Next, as shown in FIGS. 10 (C) (D) (F), the left and right bent edges (72) (73) (74) (75) (76) (77) are curled. A manufacturing method according to the second invention for manufacturing a heat exchange tube having fins will be described with reference to FIG.

First, widen the width of the inner fin (82),
The bent edge portion (85) has a shape along the inner surfaces of the left and right side walls (84) of the flat tube (81). As the flat tube (81), the conventional one,
That is, one having flat upper and lower walls (83) and left and right side walls (84) having a substantially arcuate cross section is used. Then insert the inner fin (82) into the flat tube (81), and
(82) The flat tube (81) is pressurized from both upper and lower sides. By doing this, the upper and lower walls (83) of the flat tube (81) and the inner fin (8
Not only with 2), but also with the left and right side walls (84) of the flat tube (81) and the left and right bent edges (85) of the inner fin (82). Therefore, the inner fin (82) and the flat tube (81) are joined more firmly, and the pressure resistance of the resulting heat exchange tube can be improved. As inner fins (82) to be inserted into the flat tubes (81), flat plate parts (22) (32) with protrusions (23) (33) (43) (53) (63) shown in FIGS. ) (42) (5
2) By having (62), the fluids are mixed in the heat exchange tube, and the heat exchange performance of the heat exchange tube provided with the inner fins (82) is improved.

[0032]

According to the method of manufacturing the heat exchange tube having the inner fins of the first invention, the left and right side walls are plastically deformed to reduce the springback after pressurization, and the inner fins and the upper and lower walls are closely attached. The degree will improve. Therefore, poor adhesion between the flat tube and the inner fin is unlikely to occur.

According to the manufacturing method of the heat exchange tube having the inner fins of the second invention, not only the inner fins and the upper and lower walls are in close contact with each other, but also the left and right side walls of the flat tube and the both bent edge portions of the inner fins. As a result, the flat tube and the inner fin are less likely to be poorly adhered.

[Brief description of drawings]

FIG. 1 is a perspective view illustrating a method of manufacturing a heat exchange tube including inner fins according to the first invention.

FIG. 2 is a cross-sectional view in which an inner fin is inserted in a flat tube.

FIG. 3 is a cross-sectional view of a heat exchange tube manufactured after pressurizing the flat tube, that is, manufactured by the method of the first invention.

FIG. 4 is a perspective view when the manufacturing method according to the first invention is applied to another inner fin.

FIG. 5 is a perspective view showing an example of an inner fin having a bent edge portion.

FIG. 6 is a perspective view showing another example of an inner fin having a bent edge portion.

FIG. 7 is a perspective view showing another example of an inner fin having a bent edge portion.

FIG. 8 is a perspective view showing another example of an inner fin having a bent edge portion.

FIG. 9 is a perspective view showing another example of an inner fin having a bent edge portion.

FIG. 10 is a cross-sectional view showing another modified example of the bent edge portion.

FIG. 11 is a transverse cross-sectional view of a main part for explaining the method of manufacturing the heat exchange tube provided with the inner fin according to the second invention.

[Explanation of symbols]

 (1) Flat tube (2) Inner fin (3) Upper and lower wall (4) Side wall (5) Groove (81) Flat tube (82) Inner fin (83) Upper and lower wall (84) Side wall (85) Folded edge

Claims (2)

[Claims] 1. A flat tube having upper and lower walls and left and right side walls having a groove extending in the longitudinal direction in the middle of the inner surface is prepared. Inner fins are inserted into the flat tube, and the flat tube with inner fins is provided on both upper and lower sides. A method of manufacturing a heat exchange tube provided with inner fins, characterized in that the inner fins and the upper and lower walls are brought into close contact with each other by pressurizing the inner fins and removing the grooves on the left and right side walls. 2. A flat tube having upper and lower walls and left and right side walls having a substantially arcuate cross section is prepared, and bent edges are formed on both left and right edges of the inner fin along inner surfaces of the left and right side walls of the flat tube. Insert the inner fin into the flat tube and pressurize the flat tube with the inner fin from both upper and lower sides to bring the left and right side walls of the flat tube into close contact with the left and right bent edges of the inner fin. And a method for manufacturing a heat exchange tube provided with inner fins.