JP2003114094A - Heat exchanger header - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flat shaped header 4 having two apertures with high strength at a low cost. SOLUTION: Both end sides of one metal plate sheet is folded inwardly and inversely to each other, the end sides of the sheet from the folded portions are addorsed in a position corresponding to a central portion 4b of the sheet, and folded to the sheet central portion 4b. Respective ends 4a come into contact with a wall surface of the sheet central portions 4b, and folded in an opposite direction to each other along the wall surface, thereby forming a header 4 having two hollow portions 5. A sheet central portion 4b and addorsed portions 4c are formed approximately in a plane, while the folded portion is formed in a circular pipe.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a header used for a heat exchanger such as a condenser and an evaporator of a vehicle air conditioner. In particular, the present invention relates to a header effectively applied to a heat exchanger of a refrigeration cycle in which the pressure on the high-pressure side exceeds the critical pressure of the refrigerant, such as a refrigeration cycle (CO2 cycle) using carbon dioxide (CO2) as a refrigerant.

[0002]

2. Description of the Related Art Generally, a heat exchanger has a structure in which flat tubes and corrugated fins are laminated, and both ends of these flat tubes are inserted and fixed in a header. Also, the above
In the CO2 cycle, the pressure on the high-pressure side reaches about 10 times that of the refrigeration cycle using CFC as the refrigerant. Therefore, for example, in Japanese Patent Laid-Open No. 3-260596, as shown in FIG. 5, the header is formed in a substantially circular tube shape to obtain pressure resistance. In this case, the header needs to be formed in a circular tube shape and the wall thickness of the header needs to be significantly increased, resulting in an increase in the size and weight of the header.

[0003]

[Patent Document 1] Japanese Unexamined Patent Application Publication No.
As disclosed in Japanese Patent Laid-Open No. 1-325784, it is known that the header is formed into a flat shape, the cross section is formed into an oval shape, and the connecting wall is formed in the middle portion. Since the outer shape is not a circular shape but an elliptical shape, it is possible to prevent the size from increasing. However, due to the high pressure resistance, it is necessary to form a thick wall,
As described above, it is not easy to integrally form a cylindrical body having an oval outer shape having a hollow body with a large thickness and two holes, so that the manufacturing cost is significantly increased. (Fig. 6)

It is also known to form an externally elliptical header having two holes by dividing the header into two, as in Japanese Patent Laid-Open No. 11-351783. The manufacturing cost can be reduced as compared with the case of integrally forming. However, because of the two parts, it is not possible to sufficiently reduce the parts cost,
Moreover, the number of assembly steps is increased. In addition, the sealing property of the joint between the two parts becomes a problem. (Figure 7)

In order to solve the above-mentioned problems of the prior art, it is an object of the present invention to provide a flat header having two holes which has high strength and low cost.

[0006]

According to a first aspect of the present invention, in a header for a heat exchanger, both ends of one sheet are bent inwardly in opposite directions to each other, and the sheet is more bent than the bent portion. The ends are folded back to back at the position corresponding to the center of the seat toward the center of the seat, and both ends of the seat contact the wall of the center of the seat and fold in opposite directions along this wall. In the heat exchanger header, which is bent to form two hollow portions, the central portion and the back-to-back portion of the sheet are formed to be substantially flat, and the bent portion has a substantially circular cross section. In this configuration, the back-to-back portion and the seat central wall surface are substantially flat, but the back-to-back portions can be brazed to each other, and the end surface portion of the seat can be brazed to the seat central wall surface. Even if both parts are flat, the pressure resistance is high. Further, since the bent portion where the sheets do not overlap each other is formed in a tubular shape having a substantially circular cross section, the pressure resistance is excellent. That is, since the two-hole header is formed by effectively utilizing the circular tubular portion and the flat portion,
A header with excellent pressure resistance can be obtained. Also, since one sheet is bent to form the header, it can be obtained at low cost.

According to a second aspect of the invention, in the header for a heat exchanger according to the first aspect, a plurality of slits for inserting a flat tube are formed in the central portion of the sheet, and slits are also formed in the back-to-back portions according to the slit positions. Since the flat tube is formed, the flat tube can be easily inserted and assembled, and brazing defects can be reduced.

According to the third aspect of the present invention, in the heat exchanger header according to the second aspect, the width of the slit at the back-to-back portion is set to be larger than the slit width at the central portion, so that when the flat tube is inserted at the slit portion. Positioning in the insertion direction of can be easily performed.

According to a fourth aspect of the present invention, in the heat exchanger header according to any one of the first to third aspects, since the brazing material is clad on the outer surface of the sheet, the brazing of the header fitting portion and the flat tube are performed. The brazing with the header and the header is surely performed, and the one having high brazing strength is obtained.

According to a fifth aspect of the present invention, in the heat exchanger header according to any one of the first to fourth aspects, the slits at the center of the seat are narrowed inward at both ends in the length direction. Since the slanted surface is formed on the flat tube, it is easy to insert and assemble the flat tube.

[0011]

Embodiments of the present invention will be described with reference to the drawings. 1 shows a heat exchanger such as a condenser and an evaporator of a vehicle air conditioner, FIG. 1 (a) shows a plan view, and FIG. 1 (b) shows a front view. In the heat exchanger 1, the flat tubes 2 and the corrugated fins 3 are laminated, and both ends of the flat tubes 2 are inserted and fixed in the headers 4 and 4. In this heat exchanger 1, the heat exchange medium that has flowed in from one header 4 passes through the inside of the flat tube 2 and heat is exchanged with the outside air during the passage, and reaches the other header 4 where the heat exchanger 1 Emitted from.

The structure of the header 4 will be described with reference to FIGS. The header 4 is formed of a flat sheet made of a metal plate. Explaining the manufacture of the header 4, first, both ends of the sheet are bent inwardly in opposite directions to each other, and a portion closer to the end of the sheet than each bent portion corresponds to the central portion 4b of the sheet. Fold them in the direction of contacting the center of the seat with the back to back by overlapping each other at the position. And both ends 4a
Are brought into contact with the wall surface of the central portion 4b of the seat, and then bent along the wall surface in the directions away from each other, that is, in the opposite directions.
Two hollow parts 5 are formed.

Since the central portion 4b of the sheet is formed to be substantially flat, the cross-sectional shape is substantially straight, and both end portions 4a overlap the wall surface of the central portion 4b. The back-to-back portion 4c is formed substantially flat like the central portion 4b,
Corresponding parts on both sides of the sheet overlap. Then, the non-overlapping portions are bent so as to form a substantially circular cross section, that is, a part of a circular pipe, and form two holes. That is, in the flat sheet central portion 4b and the back-to-back portion 4c, the corresponding portions of the sheets are overlapped with each other, and the non-overlapping portions, that is, the bent portions are formed in a circular tube shape, so that the pressure resistance is high. Can be very high. Therefore, even if a high-pressure heat exchange medium flows in the hollow portion 5, the header as a whole has sufficient durability.

The back-to-back portions 4c are brazed to each other, and both end portions 4a of the seat are attached to the wall surface 4b at the center of the seat.
Since they are brazed, the pressure resistance is high even if they are flat. Furthermore, since the brazing material is clad on the outer peripheral surface of the sheet and brazed at these flat mating portions, a wide brazing area can be secured and brazing strength can be improved.

As shown in FIG. 3, a slit 6 for inserting the flat tube 2 is opened in the central portion 4b of the seat,
A slit 7 is also formed in the back-to-back portion 4c at the same position. The height H1 of the slit 7 is equal to the slit 6
Is formed slightly higher than the height H2. Therefore, when the heat exchanger 1 is assembled, the flat tube 2 can be smoothly inserted without being caught when the tip of the flat tube 2 is inserted into the slit 6 and then into the slit 7. Moreover, since the flat tube 2 is guided in the insertion direction by the slit 7, it is possible to prevent the flat tube 2 from being inserted obliquely. In addition, as shown in FIG. 4, the width B1 of the slit 7 is formed to be larger than the width B2 of the slit 6, and the flat tube 2 has the width B1.
Positioning is done in the insertion direction. Therefore, when the flat tube 2 is inserted into the header 4, the arrangement position of the flat tube 2 can be prevented from varying in the insertion direction.

Further, inclined surfaces 6a are formed at both ends of the slit 6 (upper and lower portions in FIG. 4) so that the opening length of the slit 6 is gradually shortened toward the inside of the header 4. Therefore, when inserting the flat tube 2 into the slit 6, it is easy to insert. At the time of brazing, the brazing material is accumulated in the gap between the inclined surface 6a and the outer circumference of the flat tube 2, and brazing between the flat tube 2 and the header 4 is strengthened.

In the heat exchanger 1 of the above-described embodiment, the heat exchange medium flows from the one header 4 to the other header 4. However, a partition is provided in the header 4 so that the heat exchange medium is the header. The heat exchanger is not limited to the configuration of the above embodiment, and may be made to make a U-turn in 4 to flow.

【The invention's effect】

According to the heat exchanger header of the first aspect of the present invention, both ends of one sheet are bent inwardly in opposite directions, and the sheet is closer to the end than the bent portion. Is folded back to back at a position corresponding to the center of the seat in the direction of the center of the seat, and both ends of the seat are in contact with the wall of the seat center and are bent in opposite directions along the wall. Two hollow portions are formed, the central portion of the seat and the back-to-back portion are formed to be substantially flat, and the bent portion is formed to have a substantially circular tubular shape. Therefore, the circular tubular portion and the flat portion are effectively used to As a result, a header with excellent pressure resistance can be obtained at low cost.

Since the width of the slit at the back-to-back portion is formed to be larger than the width of the slit at the central portion and the slit at the back-to-back portion is used to position the flat tube in the insertion direction, the flat tube is inserted into the header. At this time, it is possible to prevent the arrangement position of the header from varying in the insertion direction.

[Brief description of drawings]

FIG. 1 is a heat exchanger to which the present invention is applied, in which (a) shows a plan view and (b) shows a front view.

2 shows a cross-sectional view of the header of the heat exchanger of FIG.

3 shows a cross-sectional view taken along the line AA in FIG.

FIG. 4 shows a cross-sectional view of the slit portion of the header of the heat exchanger of FIG.

FIG. 5 shows a conventional header.

FIG. 6 shows another conventional header.

7A and 7B show still another conventional header, in which FIG. 7A is a transverse sectional view and FIG. 7B is a perspective view.

[Explanation of symbols]

1 heat exchanger 2 Flat tube 3 corrugated fins 4 header 6 slits 7 slits

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Claims (5)

[Claims] 1. A sheet in which both ends of one sheet are bent inwardly in opposite directions to each other, and the end side of the sheet with respect to the bent portion is back-to-back at a position corresponding to the central portion of the sheet. A header for a heat exchanger in which two end portions of the sheet are bent in the direction of the central portion and both ends of the sheet come into contact with the wall surface of the central portion of the sheet and are bent in opposite directions along the wall surfaces to form two hollow portions. The heat exchanger header is characterized in that the central portion and the back-to-back portion of the sheet are formed to be substantially flat, and the bent portion has a substantially circular cross section. 2. The sheet according to claim 1, wherein a plurality of slits for inserting a flat tube are formed in a central portion of the sheet, and slits are also formed in a back-to-back portion in accordance with the slit positions. Heat exchanger header. 3. The heat exchanger header according to claim 2, wherein the width of the slit in the back-to-back portion is set larger than the width of the slit in the central portion. 4. The heat exchanger header according to claim 1, wherein a brazing material is clad on the outer surface of the sheet. 5. The inclined surface is formed at both ends of the slit in the central portion of the seat in the lengthwise direction so as to become narrower toward the inside, according to any one of claims 1 to 4. The heat exchanger header described.