JP2002364995A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve brazing performance by forming substantially elliptical insertion holes 51 of the header plate 5 of a heat exchanger 1 such that the central part inflates outward when a compression force is applied to an enlarged part 2a being inserted into the insertion hole 51 at the time of brazing. SOLUTION: In the heat exchanger 1 where the end part 21 of the flat tube 2 of a core 4 comprising the flat tubes 2 and radiation fins 3 laid in layers alternately are inserted, orthogonally to the insertion holes 51, into a header plate 5 provided with a row of insertion holes 51 and clad with a brazing material, the end part 21 is enlarged to form an enlarged part 2a, side plates 6 and 6 are arranged at the opposite ends of a pair of header plates 5 and 5 and an assembly held by a jig is brazed integrally in a brazing furnace, the insertion holes 51 are formed into substantially elliptical shape.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminate in which a header plate (core plate), a core, a side plate (bracket) and the like are assembled and an assembled body held by a jig is integrally brazed in a brazing furnace. Type heat exchanger.

[0002]

2. Description of the Related Art A heat exchanger 1 is entirely made of aluminum and has a core 4 in which a number of flat tubes 2 and a number of corrugated fins 3 are alternately stacked as shown in FIG. . The core 4 has header plates 5 and 5 connected to the top and bottom, and side plates 6 and 6 joined to the left and right. As shown in FIG. 3A, the header plate 5
Oval insertion holes 51 are arranged in a row. Flat tube 2
3 are inserted into the insertion holes 51 as shown in FIG. 3 (C), and are flared as shown in FIG. 3 (D).
a. Header tanks 50, 50 are joined to the header plates 5, 5, respectively.

[0003] The heat exchanger 1 is manufactured in the following steps. 1) The flat tubes 2 and the corrugated fins 3 are alternately laminated to form a core 4, and an end 21 of each flat tube 2 is formed.
Is inserted into each of the header plates 5, 5.
1, and the flared portion 2a is formed by flaring. 2) The side plates 6 and 6 are arranged on both sides of the core 4 and are held by a stainless steel jig 7 to form an assembled body 10. 3) One of the header plates 5 is horizontally supported by a jig to suspend the core 4 and the like, and is carried into a brazing furnace, heated and brazed integrally.

[0004] As shown in FIG.
1 has a substantially elliptical cross section, the end portion 21 of the flat tube 2 has a substantially elliptical or substantially elliptical cross section, and the flared portion 2a has a substantially truncated cone shape. Assembled body 10
When heated in a furnace, as shown in FIG.
While the flat tube 2 is pulled downward by its own weight,
The jig 7 and the core 4 receive a thermal stress due to a difference in thermal expansion.

[0005]

As shown in FIG. 5A, prior to insertion, the conventional insertion hole 51 has a substantially oblong shape, and the end 21 of the flat tube 2 has a substantially elliptical shape. ing. As shown in FIG. 5 (b), the end 21 is deformed into a substantially elliptical shape by insertion, and further, as shown in FIG. And formed into a substantially frustoconical shape.

[0006] In the brazing furnace, an external force is applied to the flared portion 2a by pulling the flat tube 2 downward by its own weight or the like. For this reason, as shown in FIG. 5D, the force F for compressing the flared portion 2a from the long diameter side is formed by the substantially oblong insertion hole 51.
Is added. Further, a compression force P is generated in the header plate 5 due to a difference in thermal expansion between the jig 7 and the core 4. As a result, the central portion of the flared portion 2a bulges and deforms inward, the clearance K between the insertion hole 51 and the flared portion 2a is increased or formed, and the brazing property of this portion is deteriorated. .

[0007] An object of the present invention is to deform the central portion of the flared portion outwardly when a compressive force is applied from the long diameter side to the flared portion which is inserted into the insertion hole of the header plate and expanded. The present invention is to provide a heat exchanger having improved brazing properties by forming the insertion hole into a substantially elliptical shape.

[0008]

According to the present invention, an end portion of a flat tube is inserted into a header plate in which insertion holes are arranged, and the inserted end portion is widened to form a widened portion. In a heat exchanger for brazing an assembled body held by a tool together in a furnace, the insertion hole has a substantially elliptical shape.

[0009]

According to the present invention, both the insertion hole formed in the header plate and the flared portion at the end of the flat tube have a substantially elliptical shape. For this reason, when an external force compressing the longer diameter side is applied to the flared portion, the central portion on the shorter diameter side swells and deforms outward. As a result, the clearance between the flared portion and the insertion hole is reduced, and the brazing property is improved.

According to the second aspect of the present invention, a pair of header plates in which insertion holes are arranged and clad with a brazing material are provided.
Insert both ends of the flat tube of the core in which the flat tubes and the radiation fins are alternately laminated, orthogonally into the insertion holes, widen both ends to form a widened portion, and furthermore, a pair of header plates. In a heat exchanger for brazing an assembled body held by a jig while abutting both ends of a side plate to both ends of a side plate, an insertion hole has a substantially elliptical shape. This configuration also has the same effect as the first aspect.

According to the third aspect of the present invention, the flared portion is formed in a substantially elliptical truncated cone shape having a cross section substantially similar to the insertion hole. For this reason, when an external force that compresses the longer diameter side is applied to the flared portion, the central portion on the shorter diameter side can be easily deformed outward, and the clearance between the flared portion and the insertion hole is more reliably reduced.

[0012]

FIG. 1 shows a heat exchanger 1 according to an embodiment of the present invention, which is mounted on a motorcycle or the like for cooling engine cooling water and is used as a radiator.
The heat exchanger 1 is made of aluminum and includes a core 4 in which a large number of flat tubes 2 and a large number of corrugated fins 3 are alternately laminated as shown in FIG. The corrugated fin 3 has a structure in which a thin band-shaped aluminum plate is formed in a meandering shape, and a louver (not shown) is formed in a portion where air flows.

Above and below the core 4, header plates 5, 5 having outer peripheral edges 52, 52 are arranged. Header tanks 50, 50 are fitted to the outer peripheral edges 52, 52 and joined to the header plates 5, 5, respectively. Side plates 6, 6 are arranged on both left and right sides of the core 4.

Both ends 21, 21 of the flat tube 2 are inserted into a number of insertion holes 51 drilled at predetermined intervals in the header plates 5, 5, and are expanded by a tube opening device (not shown). It is formed in the enlarged portion 2a. Insertion hole 51
Has a substantially elliptical shape, and the flat tube 2 is a cylindrical body having a substantially elliptical or substantially elliptical cross section, and has a flow path 11 through which cooling water passes.

The flat tube 2, the header plate 5 and the side plate 6 are all made of an aluminum plate, and a predetermined surface is clad with a brazing material. The heat exchanger 1 is integrally brazed as follows. 1) The flat tubes 2 and the corrugated fins 3 are alternately laminated, and header plates 5 and 5 are arranged above and below the tubes, respectively. 2) The end 2 of the flat tube 2 is formed by the tube opening device.
1 is enlarged to form an enlarged portion 2a. 3) A pair of side plates 6, 6 are arranged on the left and right sides of the core 4 and fixed with a stainless steel jig 7 (see FIG. 4) to form an assembled body 10 (see FIG. 4). Braze together.

In this integral brazing operation, a stainless steel jig 7 is used as shown by a white arrow shown in FIG.
Thermal expansion difference between the aluminum and the aluminum assembly 10,
In addition, the weight of the assembled body 10 is added. For this reason, a downward pulling force is applied to the flat tube 2 by its own weight, as indicated by a white arrow shown in FIG. As a result, both ends on the longer diameter side of the flared portion 2a receive the load F in the compression direction due to the edge of the insertion hole 51.

In the present invention, as shown in FIG. 1C and FIG. 2A to FIG. 2D, the insertion hole 51 formed in the header plate 5 is formed into a substantially elliptical shape, and 2), the end 21 of the substantially elliptical flat tube 2 is inserted. As shown in FIG. 2C, the end portion 21 is formed in a substantially elliptically-conical shape to form a flared portion 2a. For this reason,
In the integral brazing operation, even if the end portion 21 receives the compressive force F in the long axis direction due to the downward pulling force of the flat tube 2 due to the core's own weight, the direction in which the short diameter expands as shown in FIG. Generates a stress E. As a result, the clearance (gap) between the insertion hole 51 and the flared portion 2a is reduced, and brazing is reliably performed.

The flared portion 2a may have a substantially long truncated cone shape with the minor diameter side slightly swelling outward. It is possible to surely reduce the clearance with 51.

[Brief description of the drawings]

FIG. 1 is a front view and a sectional view of a main part of a heat exchanger according to the present invention.

FIG. 2 is a stress diagram generated in a flared portion of the flat tube of the present invention.

FIG. 3 is a front view and a cross-sectional view of a main part of a conventional heat exchanger.

FIG. 4 is a front view of an assembled body of the heat exchanger and a cross-sectional view of a main part.

FIG. 5 is a stress diagram generated in a flared portion of a conventional flat tube.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heat exchanger 2 Flat tube 3 Corrugated fin (radiation fin) 4 Core 5 Header plate 6 Side plate 7 Jig made of stainless steel 2a Mouth expansion part 10 Assembly 21 End part 50 Header tank 51 Insertion hole

Claims (3)

[Claims] 1. A header plate in which insertion holes are lined up,
A heat exchanger for inserting the end of the flat tube and widening the inserted end to form a flared portion and brazing the assembled body held by the jig in a furnace. A heat exchanger wherein the insertion hole has a substantially elliptical shape. 2. Both ends of the flat tube of a core in which flat tubes and radiating fins are alternately laminated on a pair of header plates clad with brazing material in which insertion holes are arranged in line, and the both ends of the core are orthogonal to the insertion holes. The brazing furnace inserts the both ends into a flared portion by widening the both ends to form a flared portion. The heat exchanger according to claim 1, wherein the insertion hole has a substantially elliptical shape. 3. The heat exchanger according to claim 1, wherein the flared portion has a substantially elliptical truncated cone shape having a cross section substantially similar to the insertion hole. Heat exchanger.