JP2891523B2 - Heat exchanger manufacturing method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a heat exchanger made of metal such as aluminum used for a room air conditioner or the like, and more particularly, to a method in which a heat exchanger core is bent in a width direction of a flat tube. The present invention relates to a method for manufacturing a formed non-planar heat exchanger.

2. Description of the Related Art In recent years, as a heat exchanger for a room air conditioner, a so-called multi-flow type heat exchanger, which has advantages of high heat exchange performance and low pressure loss, has been favorably used.

In this heat exchanger, as shown in FIG. 2, a plurality of aluminum flat tubes (3) are passed between a pair of hollow cylindrical aluminum headers (1) and (2) on the left and right sides. The aluminum corrugated fins (4) are arranged between the tubes (3). The refrigerant flows into one of the headers (1) from the inlet pipe (5), and at the same time, is diverted into the flat tubes (3) to exchange heat with the air flowing through the gap between the tubes (3). It merges in the other header (2) and flows out of the outlet pipe (6). In some cases, the inside of the headers (1) and (2) is partitioned to make the refrigerant meander a plurality of times.

In this multi-flow type heat exchanger, as shown in FIG. 2, for the purpose of effectively utilizing a narrow installation space to enhance heat exchange performance, a heat exchanger core (7) is used. May be configured as an L-shaped heat exchanger bent and formed in an L-shape in the width direction of the flat tube (3) at an intermediate position in the length direction of the flat tube (3).

For example, as shown in FIG. 3, the production of such an L-shaped heat exchanger is performed by inserting a straight flat tube material (9) into a tube insertion hole (8) formed in the side surface of the header (1) (2). ), A corrugated fin (4) is arranged between the tubes (9) of the skeleton, and the whole is joined together by brazing to form a flat skeleton. Make a heat exchanger substrate. Thereafter, the core of the heat exchanger base is
This is performed by bending the flat tube material (9) into an L-shape in the width direction of the flat tube material (9) at a predetermined position in the longitudinal direction.

As another manufacturing method, an L-shaped skeleton may be manufactured using a flat tube that has been subjected to a bending process in advance, and after corrugated fins are arranged between the tubes, the whole may be collectively brazed.

However, in the manufacture of this type of non-planar type multi-flow heat exchanger, in any case, the flat tube material (9) is, as shown in FIG. The flattened tube material (9) must be subjected to a bending process, so that the flattening tube material (9) shrinks due to compressive bending stress on the inside in the width direction and elongates on the outside in the width direction due to tensile bending stress. Yields
As a result, there is a possibility that the pressure resistance to the refrigerant may not be sufficient, or cracks may occur, especially on the outer side in the width direction of the flat tube (3) in the heat exchanger.

In order to cope with this, the tube width may be shortened to increase the section modulus.However, shortening the tube width also shortens the width of the fins arranged between the tubes, resulting in heat exchange performance. This is not preferable because it results in deterioration of the device.

The present invention solves the conventional problems as described above, and uses a non-planar type multi-flow heat exchanger in which a heat exchanger core is bent, using a flat tube wider than before,
It is an object of the present invention to provide a method that can be manufactured without causing a defect such as a decrease in pressure resistance and a crack or the like on a widthwise outside of a bent portion of the flat tube.

Means for Solving the Problems In the above object, the present invention provides a heat exchanger core formed by alternately arranging a plurality of flat tubes and fins, wherein both ends of each tube communicate with side surfaces of a pair of hollow headers. A method for manufacturing a heat exchanger wherein the heat exchanger core is connected and the heat exchanger core is bent in one direction in the width direction of the flat tube, wherein at least one or more partitions the interior in the width direction as the flat tube. The thickness of one end outer wall in the width direction is set to be larger than the thickness of the other end outer wall, and the thickness of the partition wall is the thickness of the one end outer wall and the thickness of the other end outer wall. Using a flat tube material made of an extruded mold material set in the middle of the wall thickness, performing a bending process in the width direction with the thick side on the outside to form a bend of the heat exchanger core. Features of heat exchanger A summary of the manufacturing method.

In the above method, the flat tube has at least one or more partition walls inside, and the thickness of one end outer wall in the width direction is set to be larger than the thickness of the other end wall, and the thickness of the partition wall is reduced. A flat tube material made of an extruded die set at an intermediate point between the thickness of the outer wall at one end and the thickness of the outer wall at the other end is used. In this way, the thickness of each outer wall and the partition wall of both ends of the tube material is adjusted according to the stress caused by the bending process.
By properly setting each wall, the adverse effect of stress due to bending can be effectively avoided in the entire region in the width direction. For this reason, the possibility that defects such as cracks occur in the wall portions such as the outer side end outer wall and the partition wall outside the bending of the flat tube due to the bending process is reduced or reduced,
After the bending, the pressure resistance of the wall and the like is not reduced or suppressed.

Examples Hereinafter, examples of the present invention will be described.

The heat exchanger to be manufactured is an aluminum L-type multi-flow heat exchanger as shown in FIG. 4 described above. It should be noted that the method of the present invention is not limited to the production of the L-shaped heat exchanger as shown in the figure, but the point is that the heat exchanger core (7) is oriented in one of the width directions of the flat tube (3). The present invention is intended to cover a wide range of non-planar type heat exchangers, and accordingly includes U-shaped, arc-shaped, etc. heat exchangers.

In the manufacture of this heat exchanger, basically, as shown in FIG. 3, the scale ton is manufactured by combining the headers (1) and (2) with the linear flat tube material (9). Disposing a corrugated fin (4) between tube materials (9); and joining and integrating the whole by batch brazing to produce a planar heat exchanger substrate.
A step of bending the heat exchanger base into an L-shape in the width direction of the flat tube (9) at a predetermined position in the lengthwise middle of the flat tube material (9). In some cases, as described above, a method of manufacturing an L-shaped skeleton by using a flat tube that has been subjected to a bending process in advance, arranging corrugated fins between the tubes, and brazing the whole as a whole is employed. May be done.

In the manufacture of the heat exchanger, a flat tube material (9) having a cross section as shown in FIG. 1 is used.

That is, the flat tube material (9) in the figure is of a multi-hole type in which the interior is partitioned into four chambers in the width direction by three partition walls (10), (11) and (12).

The wall thickness of the flat tube material (9) is set as follows.

That is, the thickness a of the outer wall (13) at one end in the width direction is set to an appropriate thickness that can withstand the pressure of the refrigerant flowing in the tube, and the thickness e of the outer wall (14) at the other end in the width direction is The thickness is set to be larger than the thickness a of the end outer wall (13). The specific size of the wall thickness e is set on a case-by-case basis depending on the bending, tube width B, and the like to be applied to the tube material (9).

The tube width B is 6 in terms of the performance of the heat exchanger.
-20 mm, preferably 6-16 mm, and more preferably 10-14 mm. If it is smaller than the lower limit, the width of the fins interposed between the tubes becomes smaller and the heat exchange performance is degraded. Inconveniences such as an increase in resistance and an increase in pressure loss occur.

The thickness b, c, d of each partition wall (10) (11) (12)
The thickness a of the thin end outer wall (13) is shown in FIG.
And the thickness e of the thick end outer wall (14) must be set to an intermediate value, and the thickness of the thin end outer wall (13) is gradually increased from the partition wall (10) side. It is preferable to set so that The wall thickness of the partition walls (10), (11) and (12) is determined by how far the partition wall is located on the neutral axis when the tube material (9) is bent in the width direction and how far away the partition wall is. Therefore, for example, the thicknesses b and c of the partition walls (10) and (11) that are not located outside the neutral axis are substantially equal to the thickness a of the thin end outer wall (13). The thickness of the partition wall (12) located outside the neutral axis may be set to be slightly thicker. In some cases, the partition walls (10), (11), and (12) may all be set to the same thickness.

The thickness f of the upper and lower outer walls (15) of the flat tube material (9) is set to be constant in the width direction in FIG. 1, but gradually toward the thick end outer wall (14). You may make it set so that it may become thick.

The production of the flat tube material (9) having such a cross-sectionally uneven wall thickness can be easily performed with good productivity by extrusion using an extrusion die having an extrusion molding hole having the cross-sectional shape, for example, a porthole die. .

And, using this straight flat tube material (9),
This is combined with the headers (1) and (2), the corrugated fins (4), etc., and the whole is integrally joined as described above to produce a flat heat exchanger base. The flat tube material (9) is bent in an L-shape in the width direction to be bent, thereby producing a multi-flow heat exchanger having an L-shaped heat exchanger core. I do.

In this bending step, no defect such as a crack is generated in the outer bent portion of the flat tube material (9), and the outer bent portion of the obtained heat exchanger tube (3) also has a sufficient pressure resistance. Will have. In addition, partition wall (10)
(11) Since the thicknesses of (12) and (12) are set as described above, they do not cause defects such as tearing during bending.

Effect of the Invention As described above, the present invention relates to a method for manufacturing a non-planar multi-flow heat exchanger in which a heat exchanger core is bent or curved, and as a flat tube, at least one or more partition walls inside. The thickness of one end outer wall in the axial direction is set to be larger than the thickness of the other end outer wall, and the thickness of the partition wall is the thickness of the one end outer wall and the thickness of the other end outer wall. Since the flat tube material made of the extruded die material set in the middle is used, the adverse effects of the stress due to bending can be effectively avoided at the outer walls at both ends and the partition wall, and the bending of the flat tube can be prevented by bending. In addition to the possibility that defects such as cracks are generated or reduced in the wall portion such as the outer side end outer wall and the partition wall, the pressure resistance strength of the wall portion and the like after bending is not reduced or reduced. Restrained It is. Therefore, a flat tube wider than before can be used, and a heat exchanger of this type having high heat exchange performance can be manufactured. In addition, there is an advantage that the bending of the tube material can be performed speedily, which can contribute to an improvement in the productivity of the heat exchanger.

In addition, since the flat tube material is made of an extruded material, it is possible to easily manufacture a flat tube having the above-described flat wall structure.

[Brief description of the drawings]

1 to 3 show an embodiment of the present invention. FIG. 1 is a sectional perspective view showing an example of a flat tube material used in the method of the present invention, and FIG. 2 is a perspective view of a heat exchanger. Figure,
FIG. 3 is a perspective view showing a tube, a header, and a fin in a separated state. FIG. 4 is a sectional perspective view of a flat tube material used in a conventional heat exchanger. (1) (2) ... header, (3) ... flat tube,
(4) fin, (7) heat exchanger core, (9) flat tube material, (10) (11) (12) partition wall, (13)
(14) ... End outer wall.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B21D 53/08 F28F 1/02

Claims (1)

(57) [Claims] An end of each tube of a heat exchanger core formed by alternately arranging a plurality of flat tubes and fins is connected at both ends to side surfaces of a pair of hollow headers, and the heat exchanger core is A method for manufacturing a heat exchanger bent in one direction in a width direction of a flat tube, wherein the flat tube has at least one or more partition walls that partition the inside in the width direction, An extruded mold member in which the thickness of one end outer wall is set to be larger than the thickness of the other end outer wall, and the thickness of the partition wall is set to an intermediate value between the thickness of the one end outer wall and the thickness of the other end outer wall. A method for manufacturing a heat exchanger, comprising: using a flat tube material made of aluminum; and bending the flat tube material in the width direction with the thick side outside.