JPH11101586A - Flat tube for heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve durability and stiffness by bending a single metal plate and constituting integrally an inner fin part inside and a tube body part at an outer periphery, and bending the inner fin part so that the bottom sides of the cylindrical parts with a triangular section are arranged alternately up and down for forming. SOLUTION: A flat tube for heat exchanger has a pair of mutually parallel plane parts 1 and 1b and has a cylindrical tube body part 1 where the section is bent. Also, it has an inner fin part 4 where a first triangular part 2 that is bent in a sectional triangular shape where a bottom side 2a touches the first plane part 1a, and a second triangular part 3 that is bent in sectional triangular shape where an adjacent side 2b is shared and a bottom side 3a touches the second plane part 1b in parallel are arranged in one piece alternately in the longer direction of the section of the tube body part 1. Then, the tube body part 1 is stuck to the entire outer periphery of the inner fin part 4 for joining, thus substantially the entire outer periphery of the tube body part is doubly overlapped 1 and stiffness is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a flat tube having an inner fin, wherein both the inner fin and the flat tube are formed by bending a single metal plate.

[0002]

2. Description of the Related Art Conventionally, as a flat tube used in a heat exchanger such as an oil cooler, a tube in which a corrugated fin is brazed and fixed therein has been widely used. There is also known a single metal plate bent to integrally form an inner fin and a flat tube.

[0003]

In particular, a flat tube used for an oil cooler or the like having a high internal pressure has been demanded to have a high reliability which is not easily deformed by the internal pressure and is resistant to damage from the outer surface. Therefore, the present invention has the following configuration in order to solve the problem.

[0004]

A flat tube for a heat exchanger according to the present invention comprises a pair of first flat portions 1a and a second flat portion 1a which are parallel to each other.
A tubular tube main body 1 having a flat surface portion 1b and having a flat cross-section, and a bottom surface 2a formed on a first flat surface portion 1a;
Is parallel to the first triangular portion 2 whose outer periphery is bent in a triangular shape, is adjacent to the first triangular portion 2 and shares the adjacent side 2b, and the outer periphery of the cross section in which the base 3a is in parallel to the second flat portion 1b is bent in a triangular shape The inner fin portion 4 integrally disposed inside the tube main body 1 so that the formed second triangular portion 3 and the second triangular portion 3 are alternately arranged in the longitudinal direction of the cross section of the tube main body 1.
The tube main body 1 is tightly joined to the entire outer periphery of the inner fin portion 4 so that the entire outer periphery of the tube main body 1 is substantially double overlapped with the tube main body. The portion 1 and the inner fin portion 4 are formed by bending a single metal plate. According to the flat tube of the present invention, since the entire outer periphery of the tube main body 1 is substantially double overlapped, liquid leakage hardly occurs against damage from the outer surface side, and can withstand a large internal pressure. Particularly, since the inner fin portion 4 is bent in a triangular shape, the tube does not deform even when a large internal pressure is applied.

[0005] Next, the present invention according to claim 2 is a preferred embodiment according to claim 1, wherein a hole 6 or a cut-and-raised portion is formed in the adjacent side 2b of the inner fin portion 4. It is a flat tube for exchangers. By forming the hole 6 or the cut-and-raised portion on the adjacent side 2b of the inner fin portion 4 as described above, the fluid flowing in the tube can be stirred, and the heat transfer performance can be improved.

[0006]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of a main part of a flat tube for a heat exchanger of the present invention, FIG. 2 is an explanatory view showing a manufacturing process thereof, and FIG. 3 is a sectional view of the flat tube.
This flat tube is obtained by bending a single metal plate to integrally form an inner fin portion 4 inside and a tube main body portion 1 on the outer periphery thereof. The inner fin portion 4 is formed by bending a cylindrical portion having a triangular cross-section such that the bottom sides are alternately arranged vertically, and the top portions are in contact with each other. Then, at the end of the inner fin portion 4, the metal plate is bent so as to be in close contact with the entire outer periphery of the inner fin portion 4 to form the tube main body 1. The surface of the metal plate is coated with a brazing material in advance. And it inserts in a high temperature furnace, brazes and fixes between each contact part in a liquid-tight manner, and completes the flat tube for this heat exchanger.

FIGS. 4 and 5 show another embodiment of the present invention. This embodiment is different from the first embodiment in that a rectangular hole 6 is formed in the adjacent side 2b of the inner fin portion 4. FIG. Is the point that was drilled. Thereby, the fluid flowing through the tube is stirred, and the transfer performance of the heat exchanger is improved. The hole 6 is formed only on the common adjacent side 2 b of the first triangular portion 2 and the second triangular portion 3. Next, FIGS. 6 and 7
FIG. 4 shows still another embodiment of the present invention.
5 is different from the example of FIG. 5 only in that the hole 6 is formed in a circular shape. Instead of these holes 6, the adjacent side 2b
A large number of cut-and-raised portions may be formed.

[0008]

According to the flat tube for a heat exchanger of the present invention, the entire outer periphery of the tube main body 1 is substantially adhered to the entire outer periphery of the inner fin portion 4 by joining the tube main body 1 to the entire outer periphery thereof. Because it is a double overlap,
The tube is highly resistant to damage from the outer surface of the tube and less likely to cause liquid leakage. And a tube with high pressure resistance can be obtained. Moreover, the inner fin portion 4 is composed of the first triangular portion 2 and the second triangular portion 3, and the respective bottom sides 2a, 3a are joined in parallel to the inner surface of the tube main body 1, so that the internal pressure increases. Does not allow internal deformation, and from that point, the pressure resistance is extremely high. Furthermore, since the inner fin portion 4 and the tube main body portion 1 are formed by bending a single metal plate, the tube is highly integrated, and from this point of view, a flat tube for a heat exchanger with high pressure resistance can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part showing a first example of a flat tube for a heat exchanger of the present invention.

FIG. 2 is an explanatory view showing a manufacturing process of the flat tube.

FIG. 3 is a sectional view of the flat tube.

FIG. 4 is an essential part perspective view showing a second example of the flat tube for a heat exchanger of the present invention.

FIG. 5 is an explanatory view showing a manufacturing process of the flat tube.

FIG. 6 is an essential part perspective view showing a third example of the flat tube for a heat exchanger of the present invention.

FIG. 7 is an explanatory view showing a manufacturing process of the flat tube.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tube main body part 1a 1st plane part 1b 2nd plane part 2 1st triangular part 2a bottom 2b Adjacent side 3 2nd triangular part 3a bottom 4 Inner fin part 5 Wax fillet 6 hole

Claims (2)

[Claims] 1. A tubular tube main body 1 having a pair of first flat portions 1a and second flat portions 1b parallel to each other and having a flat cross section formed by bending, and a first flat portion 1a. A first triangular portion 2 whose outer periphery is bent in a triangular shape in which the bottom 2a is in parallel contact with the first triangular portion 2 and which is adjacent to the first triangular portion 2 and shares the adjacent side 2b with the second flat portion 1b;
a and the second triangular portion 3 whose outer periphery is bent in a triangular shape in parallel with each other and are integrally disposed inside the tube main body 1 so as to alternate in the longitudinal direction of the cross section of the tube main body 1. An inner fin portion 4 is provided, and the entire outer periphery of the tube main body 1 is substantially double overlapped by tightly joining the tube main body 1 to the entire outer periphery of the inner fin portion 4. A flat tube for a heat exchanger, wherein the tube body 1 and the inner fin portion 4 are formed by bending a single metal plate. 2. The flat tube for a heat exchanger according to claim 1, wherein a hole 6 or a cut-and-raised portion is formed in the adjacent side 2b of the inner fin portion 4.