WO2008010344A1

WO2008010344A1 - Method for manufacturing heat exchanger and heat exchanger

Info

Publication number: WO2008010344A1
Application number: PCT/JP2007/059910
Authority: WO
Inventors: Soichi Kato; Hiromichi Ito
Original assignee: Valeo Thermal Systems Japan Corporation
Priority date: 2006-07-21
Filing date: 2007-05-15
Publication date: 2008-01-24
Also published as: JP2008025927A

Abstract

A method for forming a layer of brazing material surely on the outside of burring occurring in a tube insertion hole while boring the brazing material with a boring tool simultaneously with formation of the tube insertion hole in a header. By such method, brazing performance is enhanced by arranging the brazing material with no break for a tube being brazed and the number of processes is reduced. When manufacturing a heat exchanger where a tube is connected to the header (2) of the heat exchanger by using the brazing material (8), a sheetlike brazing material (8) is superposed on the header (2). A large number of tube insertion holes (6) are then bored in the header (2) together with the brazing material (8) by means of the boring tool (16) of a press. Consequently, burring (6a) and the layer of the brazing material (8) on the outer surface thereof are formed simultaneously in the tube insertion hole (6). Thereafter, a tube (1) is inserted into the tube insertion hole (6) and brazed in a furnace.

Description

Manufacturing method of heat exchanger and heat exchanger

Technical field

TECHNICAL FIELD [0001] The present invention relates to a method for manufacturing a heat exchanger and a background art related to the heat exchanger made by this manufacturing method.

[0002] A heat exchanger composed of a pair of headers and a large number of tubes arranged between the pair of headers and configured by inserting the tube into a tube insertion hole formed in the header, In the manufacturing process, the tube is joined to the header by brazing, and the applicant applies a paste-like brazing material after the tube insertion hole is formed in the tube. The force of application of this paste-like brazing material is difficult, and there are many defects in brazing. Manufacturing was unstable. Also, there is a conventional technique shown in Patent Document 1.

Patent Document 1: Japanese Unexamined Patent Application Publication No. 2004-271005

[0003] In the technique shown in Patent Document 1, in addition to the process of forming a large number of tube insertion holes lc in the header 1, a large number of cuts 10a are also formed in the brazing material foil 10 at portions corresponding to the tube insertion holes. And the process of aligning the position of the notch 1 Oa with the tube insertion hole 1c of the header 1, Hold tube 2 and insert tube 2 into tube insertion hole lc. It is said that the brazing material foil is rolled in at the time of insertion, so that the effect of improving the brazing can be obtained.

[0004] By the way, when the tube insertion hole is formed in the header, the header is deformed by a punching tool of the press. As a result, the tube 2 is not reliably inserted into the tube insertion hole lc, and the defect rate increases. For this reason, a technique as shown in Patent Document 2 has been developed.

Patent Document 2: JP 2005-153001

[0005] In Patent Document 2, when straightening the extruded tank 4, a liquid is injected into the tank 4 and a high pressure is applied. At that time, a tube insertion hole 6 is drilled to Prevents deformation. Disclosure of the invention

Problems to be solved by the invention

[0006] However, Patent Document 1 requires a process of forming the tube insertion hole lc in the header and a process of forming the cut 10a in the brazing material foil. Also, when the brazing material is overlaid on the header 1, if the brazing foil notch 10a and the tube insertion hole lc are not aligned and misaligned, the brazing material foil cannot be wound as intended. Failure to braze may occur. Furthermore, in the processing facility of Patent Document 2, it is necessary to inject a liquid into the tank and apply a high pressure. For this reason, the processing equipment requires a liquid storage unit and a pressurizing device, and is large and expensive.

[0007] Therefore, an object of the present invention is to form a brazing material layer on the surface of the burring generated in the tube insertion hole while simultaneously drilling the brazing material with a drilling tool at the time of forming the tube insertion hole in the header. In addition, a brazing material is surely arranged between the tubes to be brazed to improve the brazing property and reduce the number of processes.

Means for solving the problem

[0008] A method of manufacturing a heat exchanger according to the present invention includes a pair of headers and a number of tubes arranged between the pair of headers, and refrigerant is supplied from one header to the other header through the tubes. In the manufacturing method of the heat exchanger that is made to flow, after the brazing material formed in a sheet shape is superimposed on the header, a number of tube insertion holes are formed in the header together with the brazing material by a punching tool of a press. Burring and forming a layer of brazing material on the surface of the tube insertion hole, and inserting the tube into the tube insertion hole and brazing in the furnace (Claim 1). .

[0009] Thereby, the tube insertion hole is formed together with the brazing material overlapped on the header at a time, and the brazing material is arranged in close contact with the tube insertion hole and the front side of the burring portion. The brazing with the inserted tube is improved.

[0010] In addition, by forming a tube insertion hole in the header together with the brazing material, the brazing material does not use any processing or bonding technique on the header, so that the brazing material force S pulling force By fixing, it is fixed (Claim 2).

[0011] The brazing material has a flux adhered to both or one side thereof (Claim 3). Ma The brazing material is preferably thin-walled toward the tip of the burring (Claim 4). Then, the length of the brazing material is shorter than the total length of the header in the longitudinal direction (Claim 5).

[0012] Further, the brazing material is provided with a notch for preventing the partition plate insertion hole from being blocked at a portion facing the partition plate insertion hole formed in the header, before the tube insertion hole is drilled. Preferably, the notch is in a shape that does not contact the partition plate (claim 7). As a result, during the process of forming the tube insertion hole, the brazing material is stacked on the header, but the partition plate in which the brazing material does not block or contact the partitioning plate insertion hole is smoothly inserted into the partitioning plate insertion hole. be able to. Also, if the brazing material is in contact with the partition plate at the time of brazing, the brazing material is sucked into the header during the brazing process, and troubles are likely to occur in brazing between the partition member and the header. The occurrence of this defect can be completely prevented by appropriately forming the notches.

[0013] In the heat exchanger according to the present invention, in a heat exchanger that brazes a tube to a heat exchange header using a brazing material, a plurality of tube insertion holes drilled in the header by a punching tool; A burring formed in the tube insertion hole, a brazing material layer formed on at least a part of the surface of the burring, and a tube inserted in the tube insertion hole. The insertion hole is brazed through a burring (Claim 8). As a result, the burring of the tube insertion hole becomes a dimension that is two to three times longer than the header thickness, and the joining area with the tube is increased, so that brazing can be performed firmly.

[0014] The brazing material layer formed on at least a part of the surface of the burring is made of a sheet-like brazing material (claim 9).

Next, since the header is deformed by pressure when the tube insertion hole is formed in the header, an apparatus for forming the tube insertion hole has been developed for the purpose of preventing this. This tube insertion hole forming apparatus includes a press drilling tool for drilling a large number of tube insertion holes in a header, and a cored bar inserted into the header, and the cored bar extends in the axial direction. One member is formed with a receiving hole for the punching tool of the press, and one of the two members is moved in the axial direction to change the radial dimension. [0016] Thereby, the core metal force for preventing deformation of the header when the tube insertion hole is formed, the radial dimension can be changed by moving one of the members in the axial direction, so that before the header is heated, In addition, the header can be easily taken out after the burring formed in the tube insertion hole is not caught on the core bar.

[0017] The change in the radial dimension of the cored bar reduces the radial dimension by forming irregularities alternately and continuously on the opposing surfaces of the two members, and both convex parts entering both concave parts. However, the radial dimension is expanded by the contact of the two convex portions. In other words, the change in the radial dimension of the cored bar can be achieved by moving one member of the cored bar in the axial direction by the concave part and the convex part formed on the opposing surface. It is done by butting the part.

[0018] The radial dimension of the cored bar is expanded by abutting the opposing convex parts, but since there is an inclination that preferably forms an inclination on the abutting surface, a slight radial movement ( It is possible to change the amount of increase / decrease by making this inclination angle arbitrarily. In addition, the inclination can smooth the movement of one member of the cored bar in the axial direction.

The invention's effect

As described above, according to the method for manufacturing a heat exchanger of the present invention, when forming the tube insertion hole of the header, the brazing material is simultaneously processed because it is superimposed on the header, and the process is omitted. The brazing material is arranged on the entire surface of the tube insertion hole with good adhesion and over the entire surface, and it is possible to reduce the problem of brazing failure due to brazing (claim 1).

[0020] Since the tube insertion hole is formed in the header together with the brazing material, the brazing material can be securely fixed by pulling on the burring portion without using a processing or bonding method separately on the header. Yes (claims 1 and 2).

[0021] The sheet-like brazing material has a notch for preventing the partition plate insertion hole from being blocked, and the notch is in a shape that does not contact the partition plate. The plate insertion hole is not blocked and does not come into contact with the partition plate, so that it is possible to prevent a problem that the brazing material is sucked into the header during brazing (claims 6 and 7).

[0022] Further, according to the heat exchanger of the present invention, the burring of the tube insertion hole is 2 mm larger than the header thickness. As long as it is about 3 times longer, it is possible to improve the bonding strength and reduce the brazing defect rate by expanding the bonding area with the tube (claim 8).

Brief Description of Drawings

FIG. 1 is a perspective view showing a state in which a tube insertion hole into which a tube is inserted is formed in a header and a brazing material is attached to the surface in the present invention.

FIG. 2 is a perspective view showing the state before the brazing material is overlaid at the stage before the tube insertion hole is formed in the header in the invention of the above.

FIG. 3 is a cross-sectional view in which a tube insertion hole is formed in the header by a punch, and a layer of brazing material is formed on the surface thereof.

FIG. 4 is a cross-sectional view of a tube inserted into a tube insertion hole.

[FIG. 5] FIG. 5 to FIG. 11 show the processing procedure of the tube insertion hole in the header using the punch and the cored bar, which is a tube insertion hole forming device, and FIG. 5a shows the header covering the cored bar. Fig. 5b is a partially enlarged view of the cored bar, showing the state before being worn.

FIG. 6 is an explanatory diagram of a state in which a header is attached to a mandrel (work set).

[FIG. 7] FIG. 7a is an explanatory view of a state in which the radial dimension of the cored bar is enlarged and one member is pressed against the inner surface of the header (Mandrel Slide), and FIG. 7b is a partially enlarged view of the cored bar.

FIG. 8 is an explanatory view of a state where the punch of the press has dropped and a tube insertion hole is formed in the header (piersing).

[FIG. 9] FIG. 9a is an explanatory view of a state in which the punch of the press is returned and a tube insertion hole is formed in the header (pie rce back). Figure 9b is an enlarged cross-sectional view of the main part.

[FIG. 10] FIG. 10a is an explanatory view of a mandrel down state in which the radial dimension of the cored bar is reduced. Figure 10b is an enlarged view of the main part.

FIG. 11 is an explanatory diagram showing a state in which the core strength header is taken out.

Explanation of symbols

[0024] 1 tube

2 Header

6 Tube insertion hole

6a burring 7 Partition hole

8 Raw material

9 Notch to prevent blockage

15 Tube insertion hole forming device

16 punches

17 Core

17a Core metal

17b The other part of the metal core

18 Receiving hole

20a recess

20b Convex

21a recess

21b Convex

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Example 1

1 to 4 show a heat exchanger manufacturing method according to the present invention and a heat exchanger manufactured by the manufacturing method. The heat exchanger includes a tube 1 serving as a heat exchange medium passage such as a refrigerant inside, fins (not shown) alternately arranged with the tube 1, and headers 2 arranged at both ends of the tube 1. Then, the refrigerant flows in and out through the inlet / outlet provided in the header 2.

The header 2 is a hollow body made of aluminum alloy and having a partition wall 3 in the central longitudinal direction, and has two chambers 5 and 5. As shown in FIG. 1, the header 2 has a large number of tube insertion holes 6 and partition plate insertion holes 7 formed on one surface.

[0028] The tube 1 is fitted into the tube insertion hole 6 and then brazed in the furnace. In order to properly attach the brazing material to the tube insertion hole 6, the following manufacturing method is used in the present invention. Has adopted.

[0029] FIG. 2 shows an extruded header 2 and a brazing material 8 above it. The state before the brazing material 8 is superimposed on the header 2 is shown. The header 2 is formed with an insertion hole 7 for a partition plate used for changing the flow of the refrigerant (2 pass, 4 pass).

[0030] The brazing material 8 is formed with a notch 9 for blocking prevention at a position corresponding to the insertion hole 7 of the partition plate. The notch 9 is formed larger in width and length than the insertion hole 7 of the partition plate. The brazing material 8 is made of a metal (aluminum alloy) that has a known material strength having a melting point lower than that of the joining base material, and is formed into a sheet shape with the same shape as the top shape of the header 2, and the upper and lower surfaces thereof. Alternatively, a flux is applied on one side. The longitudinal dimension of the brazing material 8 is shorter than the longitudinal dimension of the header.

[0031] After the header 2 and the brazing material 8 are subjected to the pretreatment described above, the brazing material 8 is superimposed on the header 2. Then, the punching tool (bunch 16) of the press of the tube insertion hole forming device 15 as described below is dropped, and the hole is processed. That is, due to the relationship between the punch 16 and the receiving hole 18 of the metal core 17 (see FIG. 7A), the tube insertion hole 6 is subjected to burring.

FIG. 3 shows a state in which the tube insertion hole 6 is formed, the burring 6a extends in the direction of the core bar, is formed to be 2 to 3 times the thickness of the header 2, and the brazing material 8 is also It extends to the entire surface of the paring 6a of the entrance hole 6, and the force is also formed in close contact with the burring 6a so that it is firmly bonded. The thickness of this brazing material 8 is about 200 m, and it becomes thinner as it goes inside the hole.

FIG. 4 shows a state in which the tube 1 (shown by a two-dot chain line) is inserted into the tube insertion hole 6. In this state, the brazing material 8 is evenly arranged between the tube 1 and the burring 6a of the tube insertion hole 6, and the tube 1 is securely brazed to the header 2 during brazing in the furnace.

[0034] FIGS. 5 to 11 show the movement of the device 15 for forming the tube insertion hole 6 in the header 2 and the core bar 17 of the device, and the processing procedure thereby. In FIG. 5 (a), as a tube insertion hole forming device 15, a punch 16 which is a drilling tool attached to the press upward and placed inside the header 2 to prevent deformation during processing. And a header 2 is shown.

The cored bar 17 has a rod-like shape and has a split surface in the axial direction and is composed of two members 17a and 17b. When the header 2 is inserted into the cored bar 17, one member 17a The top surface of the header 2 A number of receiving holes 18 into which the punches 16 are inserted are formed on the upper surface of the structure in contact with the inner surface. Further, a concave portion and a convex portion are continuously formed on the opposing surfaces of both members 17a and 17b of the cored bar 17, respectively.

[0036] A concave portion 20a and a convex portion 20b are formed on the opposing surface of one member 17a, and a concave portion 21a and a convex portion 21b are formed on the opposing surface of the other member 17b. And the convex part 20b and the convex part 21b are abutted like FIG.5 (b). In this state, the radial dimension of the cored bar 17 is slightly smaller than the inner diameter direction of the header 2. The metal core 17 is connected to a drive device (not shown) for supporting and moving the metal core 17 on one left side thereof.

FIG. 6 shows a state (work set) in which the header 2 is inserted into the cored bar 17. The cored bar 17 is in the state shown in FIG. Since the others are the same, the same reference numerals are assigned to the same members.

[0038] In FIGS. 7 (a) and 7 (b), the other member 17b of the cored bar 17 is powered to the right in the axial direction, and the abutting state of the convex part 20b and the convex part 21b changes, and both convex parts 20b , 2 lb. Inclination force formed in the radial direction The dimension in the radial direction is expanded, and the upper surface of one member 17a comes into contact with the inner surface of the header 2 (Man drei slide) ₀

[0039] FIG. 8 shows a state where the punch 16 of the press is dropped and the tube insertion hole 6 is formed in the header 2 (Piercing). The other core 17 is the same as the previous stage and is stationary.

[0040] FIGS. 9 (a) and 9 (b) show a state in which the punch 16 of the press is returned and the insertion hole 6 is formed in the header 2 (Pierce back). In this state, as shown in FIG. 3, a burring 6 a is provided in the tube insertion hole 6, and one member 17 a of the core bar 17 remains in contact with the header 2. That is, the burring 6a extends into the receiving hole 8 of the opposite member 17a.

[0041] In FIGS. 10 (a) and 10 (b), the other member 17b of the metal core 17 is moved to the left in the axial direction, the convex portion 20b fits into the concave portion 21a, and the convex portion 21b fits into the concave portion 20a. The radial dimension is reduced. Specifically, one member 17a falls downward, and a gap δ is generated between the upper surface of the member 17a and the inner surface of the header 2 (Mandrel down).

[0042] In FIG. 11, since the radial dimension of the core bar 17 has decreased (one member 17a has dropped), the burring 6a of the tube insertion hole 6 has no catching force, and the header 2 has been moved. From core 17 The state where da 2 is removed is shown (work reject). In the tube insertion hole 6 formed in this way, as shown in FIG. 4, the tube 1 (shown by a two-dot chain line) is inserted in the next step, and the brazing material 8 is burring the insertion hole 6. Compared with the conventional structure in which the burring 6a is sufficiently interposed between the header 6 and the burring 6a by 2 to 3 times the thickness of the header 2, the brazing strength can be improved.

Claims

The scope of the claims

[1] In a method of manufacturing a heat exchanger comprising a pair of headers and a large number of tubes arranged between the pair of headers, wherein the refrigerant flows through one header force tube to the other header,

After the brazing material formed in a sheet shape is superimposed on the header, a number of tube insertion holes are bored in the header together with the brazing material with a punching tool of the press, and a ring and at least the tube ring are formed in the tube insertion hole. A method for producing heat exchangers, characterized in that a layer of brazing material is formed on a part of the surface, and a tube is inserted into the tube insertion hole and brazed in a furnace.

[2] The method for producing a heat exchanger according to claim 1, wherein the brazing material can be fixed to the header by forming a tube insertion hole in the header together with the brazing material.

[3] The method for manufacturing a heat exchanger according to claim 1 or 2, wherein the brazing material has a flux attached to both surfaces or one surface thereof.

[4] The method for producing a heat exchanger according to any one of [1] to [3], wherein the brazing material is formed in a thin shape toward the tip of the burring.

[5] The method for manufacturing a heat exchanger according to any one of claims 1 to 4, wherein a longitudinal dimension of the brazing material is set shorter than a longitudinal dimension of the header.

[6] In the brazing material, a notch for preventing the partition plate insertion hole from being blocked is formed at a position facing the partition plate insertion hole formed in the header, before the tube insertion hole is drilled. The method for producing a heat exchanger according to any one of claims 1 to 5, wherein:

7. The method for manufacturing a heat exchanger according to claim 6, wherein the notch has a shape that does not contact the partition plate.

[8] In a heat exchanger that brazes a tube to a heat exchange header using brazing material,

A number of tube insertion holes drilled in the header by a press drilling tool, a burring formed in the tube insertion hole, a brazing material layer formed on at least a part of the burring, and inserted in the tube insertion hole Tube and

A heat exchanger characterized in that the tube is brazed to the tube insertion hole via a burring by brazing in a furnace.

[9] The brazing filler metal layer formed on at least a part of the surface of the burring is made of a sheet-like brazing filler metal. The heat exchanger according to claim 8, wherein: