JP2001071177A - Manufacture of brazing-material coated pipe and manufacturing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformly form a brazing material layer on an outer face of a seamless pipe body, to prevent diffusion of components forming the brazing material layer to a side of the pipe body at the time of forming the brazing material layer, and to enable arbitrary addition of a necessary amount of a prescribed flux or a sacrificial corrosion prevention material to the brazing material layer. SOLUTION: A diameter of a pipe body 55 is reduced by inserting the metallic pipe body 55 through a port 50 of a die having an entrance part and an exit part, and a brazing material layer 71 is coated around the pipe body by force-fitting a brazing material 70 in a non-molten and heated state or in a semi-molten state around the peripheral part of the pipe body 55 inserted into the entrance part of the port of the die, thus a brazing material drawn pipe having the pipe body provided with the brazing material layer is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for producing a brazing material cladding tube suitable for use in a tube such as a heat exchanger, and to a technique for producing a tube clad with brazing material by drawing.

[0002]

2. Description of the Related Art FIG. 11 shows an example of a conventionally known heat exchanger made of aluminum. A heat exchanger A shown in FIG.
And a plurality of tubes 3 connected between the header pipes 1 and 2 and connected to the header pipes 1 and 2 at substantially right angles to the header pipes 1 and 2 and fins joined to the outer surfaces of the tubes 3 4... As a main component. The heat exchanger A shown in FIG. 11 is generally called a parallel flow type, has a high heat exchange efficiency, and is widely used for applications such as on-vehicle use.

FIG. 12 shows another example of an aluminum heat exchanger generally known in the prior art. A heat exchanger B shown in FIG. 12 has a flat tube 5 provided in a meandering state, The fins 6... Brazed to the meandering portion formed by the tube 5 are mainly constituted.
The heat exchanger B shown in FIG. 12 is generally called a serpentine type and is widely used.

[0004] The conventional heat exchanger A shown in FIGS.
B generally has fins 4, 6 and tubes 2, 2 '.
Is composed of a clad plate called a brazing sheet. This brazing sheet 7 is shown in FIG.
As shown in the cross-sectional structure, a brazing material layer 9 made of a brazing alloy such as an Al-Si alloy is roll-rolled on both surfaces (in some cases, one surface) of a thin plate-shaped base material 8 made of aluminum or an aluminum alloy. Fins 4 or fins 6 are formed by processing the brazing sheet 7 into a wave shape, and the tubes 3, 5 are formed by extruded tubes (multi-hole tubes) generally made of an aluminum alloy. Have been.
Also, the brazing sheet 10 whose sectional structure is shown in FIG.
This brazing sheet 10 is also formed by clad-pressing a brazing material layer 9 on one surface of a base material 8 and an Al-Zn-based sacrificial anode material layer 11 on the other surface by roll rolling.

On the other hand, the brazing sheet 7 or the brazing sheet 10 is rounded into a tube as shown in FIG. 15 to form an electric resistance welded tube 15 in which the butted portions 13 are joined. The tube 3 or the tube 6 of the heat exchanger may be configured.
Further, the brazing sheet 7 or the brazing sheet 10 is rounded into a B-shaped section as shown in FIG. 16 to form a tube 16 in which the butted portions are joined, and this tube 16 is used to form the tube 3 or the tube 5 of the heat exchanger. Has also been made.

For example, the enlarged structure of the portion where the fin 4 and the tube 3 are in contact with each other is as shown in FIG. 17, and the brazing material layer 12 formed on one surface of the fin 4 is arranged so as to be in contact with the tube 3. Then, in this state, the fins 4 can be brazed to the tube 3 by charging the brazing material layer 12 in an atmosphere control heating furnace or the like and changing the atmosphere to an argon atmosphere or a nitrogen gas atmosphere and then cooling.
The heat exchanger A having the structure shown in FIG. 11 is to be assembled.

As another method, it is also known to use a tube 16 having a brazing material layer 17 applied to the outer surface thereof, as shown in FIG. As a method of applying the brazing material layer 17, powder of the Al—Si alloy powder is dissolved in a solvent together with a flux and a binder to form a slurry or a paste, and the slurry or the paste is applied to the upper and lower portions of the tube 16 using an application roll. A method of applying to both sides is known.

[0008]

The heat exchangers A and B described above.
When the brazing sheet 7 or the brazing sheet 10 is constituted by the brazing sheet 7 or the brazing sheet 10 and these brazing sheets are rounded and joined by seam welding, the joint seam portion of the tube is different from other portions. In order to form a structure, there is a problem that it is more difficult to prevent the occurrence of a leak and the destruction due to the progress of corrosion at the seam joint as compared with a seamless pipe of an integrally molded product.

Further, since it is difficult to manufacture a seamless clad tube by extrusion molding, a method of applying a slurry of a brazing material layer to a seamless tube body and drying and fixing it as described above has been adopted. Since the binder contained in these slurries is contained in the brazing material layer, there has been a problem that the binder is vaporized during brazing, generating unnecessary gas. Assuming that a clad tube coated with a brazing material by extrusion is to be manufactured, considering that the melting point of the Al-Si alloy brazing material is lower than the melting point of aluminum or an aluminum alloy constituting the tube, It is considered that only the brazing filler metal is easily extruded depending on the temperature at the time of extrusion, and it is easy to become a large-scale extrusion equipment that can individually control the temperature control of the pipe and the brazing filler metal, and it is possible to obtain a pipe coated with the brazing filler metal temporarily. Even if it is possible, it is difficult to produce a pipe coated with a brazing material having a uniform thickness, and the adhesion of the brazing material tends to be weak, and the brazing material may easily peel off. .

On the other hand, in the portion where the fins are brazed to the tubular body made of the brazing sheet, the brazing is performed by melting the brazing material layer formed on the brazing sheet or the fins. Before and after melting, the outer diameter of the tube changes, and it becomes necessary to design the heat exchanger in anticipation of the melting of the brazing material layer of the tube, which complicates the design. Had become. Further, as a method of forming a brazing material layer, a method of directly applying a molten brazing material to a tube body is also considered. However, when an Al-Si alloy is used as a brazing material, when a molten Al-Si alloy adheres to the tube body. However, there is a problem that Si contained in the brazing material diffuses into the inside of the tube, and Si diffuses into aluminum or an aluminum alloy constituting the tube, so that pitting corrosion easily occurs in the tube, and corrosion resistance is increased. There is a problem that causes the deterioration of.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and an object of the present invention is to form a brazing material layer uniformly on the outer surface of a tubular body, such as seamless, A method and a method for manufacturing a brazing material cladding tube capable of preventing the required amount of flux, binder or sacrificial anticorrosion material from being freely added to the brazing material layer while preventing the diffusion of the brazing material layer constituent components toward the pipe body. The purpose is to provide the device.

An object of the present invention is to enable the manufacture of a brazing material clad tube coated with a brazing material layer having or not having at least one of a flux and a binder. Since the brazing material layer can be coated on the outer surface of the tube body without performing brazing, a manufacturing method and a manufacturing apparatus capable of obtaining a brazing tube that does not generate gas or binder residue due to vaporization of the binder during brazing are provided. With the goal. In addition, the manufacturing method and apparatus of the present invention can be applied to brazing material coating in which a binder is mixed in order to particularly enhance the brazing material adhesion. Further, according to the present invention, even in a structure having a brazing layer on the outer surface of the tubular body, even after the brazing is performed and the brazing material layer is melted, there is little change in the outer diameter of the tubular body, and the assembly design is improved. An object of the present invention is to provide a brazing material cladding tube which does not need to consider the molten portion of the material layer and facilitates the design of an assembled product by brazing.

[0013]

In order to solve the above-mentioned problems, a manufacturing method of the present invention inserts a metal pipe into a die hole having an inlet and an outlet, and inserts a metal tube into the die at the inlet side of the die. A brazing material layer is provided around the pipe by supplying a brazing material in a heated or semi-molten state at room temperature or not melted around the peripheral portion of the pipe inserted into the pipe, and the pipe and the brazing material layer Forming a brazing material cladding tube comprising: In the present invention, as a pipe inserted into the die hole, a seamless pipe obtained by extrusion molding from aluminum or an aluminum alloy, a perforated pipe, or an electric resistance welded pipe obtained by processing a plate material of aluminum or an aluminum alloy. Preferably, it is used. In the present invention, at least one of a flux and a binder may be mixed with the brazing material to form a brazing material layer. In the present invention, when the brazing material is mixed with a flux, the brazing material is supplied at a room temperature or in a non-molten state while the flux is mixed with the brazing material. It is characterized by supplying brazing material.

In the present invention, it is preferable to use a tube having a groove on the outer periphery as the tube inserted into the die hole. Further, in the present invention, when the thickness of the tube is t, the width of a groove formed on the outer peripheral surface of the tube is W, and the depth of the groove is h, h / t is 0.2 or less, W / h is 1 to 100
It is preferable to set the range to 0.

Next, in order to solve the above-mentioned problems, the manufacturing apparatus of the present invention has a die having a die hole having an inlet and an outlet, and is connected to the inlet of the die hole and integrated with the die. The cylinder device is configured such that a tube made of aluminum or an aluminum alloy can be inserted and the tube can be introduced into a die hole of a die. An aluminum alloy powder brazing material for pipe brazing is press-fitted around the outer periphery of the pipe inserted into the cylinder so that the aluminum alloy powder brazing material is heated to a temperature lower than its melting point in the cylinder device. A heating device capable of heating to a temperature is provided.

Further, in the manufacturing apparatus of the present invention, there is provided a die having a die hole having an inlet and an outlet, and a cylinder device connected to the inlet of the die hole and integrated with the die. A cylinder main body integrated with a die by connecting a press-fitting chamber provided therein to an inlet side of a die hole; and a cylinder main body formed at a rear side of the cylinder main body from outside the cylinder main body. An introduction part for introducing a tube of aluminum or an aluminum alloy into the press-fitting chamber in the inside and introducing the tube to the inlet side of the die hole, and an insertion hole provided in the cylinder main body and through which the tube is inserted. A pressurizing piston movably provided in the cylinder body along an inner wall of the cylinder body and the syringe body provided in the cylinder body; And a pressing mechanism provided on the rear side of the pressurizing piston to press the pressurizing piston toward the die in the cylinder main body, and a side closer to the die than the pressurizing piston in the cylinder main body. A pressurized chamber is formed freely around the inner surface of the cylinder body, the pressurized piston, the pipe and the die, and the pressurized chamber can be filled with an aluminum alloy powder brazing material for coating the pipe. In addition, a heating device is provided outside the cylinder body, the heating device being capable of heating the aluminum alloy powder brazing material filled in the pressurizing chamber to a temperature lower than its melting temperature.

In the manufacturing apparatus of the present invention, it is preferable that the pressurizing chamber can be freely filled with a flux, a zinc powder, or a binder in addition to the aluminum alloy powder.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to the following embodiments. FIG. 1 is a cross-sectional view showing a state in which a brazing material cladding tube is manufactured using an example of a brazing material cladding tube manufacturing device according to the present invention. FIG. 2 is an example of a brazing material cladding tube manufacturing device according to the present invention. The manufacturing apparatus D of this embodiment includes: a die 51 having a die hole 50;
Cylinder device 5 provided integrally with this die 51
2 as a subject.

The die 51 of this embodiment has an entrance 53
And a die hole 50 having an outlet portion 54. The inlet portion 53 of the die hole 50 is formed of an inclined surface having a relatively large throttle angle.
It is formed from an inclined surface having a smaller aperture angle. It is preferable that the die hole 50 has an approach angle (restriction angle) that can slightly reduce the outer diameter of the tube body 55 through which the die hole 50 is inserted. The inner diameter may be such that the tube 55 is not squeezed as in the structure of the embodiment, that is, the inner diameter may be such that the tube 55 is not penetrated. The shape of the die hole 50 is not limited to a simple inclined surface as shown in FIGS. 1 and 2, but may be an R-shaped inclined surface or a shape having irregularities on the inclined surface. It can be anything.

A cylinder device 52 is provided outside the entrance 53 of the die 51. This cylinder device 5
Reference numeral 2 denotes a cylindrical cylinder body 57 in this embodiment, and a pressurizing piston 58 provided inside the cylinder body 57.
And a pressing mechanism 59 for applying a pressing force to the pressurizing piston 58, and a heating device 60 provided on the outer peripheral portion of the cylinder body 57.

In the cylinder body 57, the dies 51
An opening is formed at the end 57a on the side, the opening covers the entrance 53 side of the die hole 50, and the end 57a is brought into close contact with the back portion of the die 51 so that the cylinder body 57 is joined to the die 51. It is integrated. Further, at the center of the other end wall on the other side of the cylinder body 57, there is formed an introduction portion 63 also serving as an insertion hole for inserting a tube 55 to be processed by the die 51. Further, an insertion hole 65 through which the above-mentioned tube 55 can be inserted is formed at the center of the pressurizing piston 58 provided inside the cylinder main body 57, and the introduction hole 65 is provided inside the cylinder main body 57. The pipe 55 introduced from the portion 63 is configured to be introduced into the die hole 50 through the insertion hole 65. When the pipe 55 into which the pressure piston 58 is inserted is introduced into the die hole 50, the pressure piston 58, the inner surface of the cylinder body 57, the die 51, and the pipe 55 are provided on the die side of the cylinder body 57. A press-fit chamber 64 that is partitioned is formed.

The pressing mechanism 59 includes a pressing chamber 6 formed behind the pressing piston 58 inside the cylinder body 57.
6, a supply pipe 67 connected to the pressurizing chamber 66, and a pressurized fluid supply device 68 connected to the supply pipe 67,
When the pipe 55 is inserted through the cylinder body 52 as shown in FIG.
Can be pressed to the die 51 side. Therefore, in this embodiment, the press-fitting portion is constituted by the pressurizing piston 58, the cylinder body 57, and the pressurizing chamber 64.

The heating device 60 is a heating heater constructed by adding a heating element such as a heating wire to the outer peripheral portion of the cylinder body 57.
By operating 0, the inside of the cylinder body 57 can be heated to a desired temperature. In the present embodiment, to the extent that the powdered brazing material charged into the cylinder body 57 is not melted, as described later, or
Since the heating device 60 may be heated to a semi-molten state, the heating device 60 preferably has a calorific value enough to heat and maintain a powdery brazing material described later at a temperature slightly lower than its melting temperature. For example, as a powdered brazing material, Al-Si
When an alloy powder is used, the melting point is about 640 ° C., and pure aluminum has a melting point of 650 to 660 ° C. Therefore, it is preferable to be able to heat to about 10 ° C. to 30 ° C. lower than these temperatures.

In the structure shown in FIGS. 1 and 2, the description of the hydraulic seal mechanism in the introduction portion 63 for introducing the pipe 55 into the cylinder body 57 is omitted. Further, the description of the hydraulic seal mechanism is omitted in a portion of the pressurizing piston 58 through which the pipe 55 is inserted. In addition, a water cooling mechanism may be incorporated into the pressurizing piston 58 as necessary, and the temperature may be controlled so that the powdered brazing filler material filled between the pressurizing piston 58 and the die 51 does not reach the melting point as described later. preferable. If the pressurizing piston 58 is cooled by a water cooling mechanism, a part of the powdered brazing material is partially melted with pressurization, and the pressurizing piston 58 and the pipe 5
5 can be prevented.

In order to manufacture a brazing material cladding tube using the manufacturing apparatus D having the structure shown in FIGS. 1 and 2, first, a seamless tube 55 formed by extrusion from aluminum or an aluminum alloy is prepared. Tube 5 used here
5 is an extruded multi-hole tube frequently used in a heat exchanger,
A material having a joint seam such as an electric resistance welded tube may be used.

The above-described tube 55 is introduced into the cylinder main body 57 from the introduction portion 63 of the cylinder main body 57, and is further introduced through the pressurizing piston 58 into the die hole 50 side. The tip of the tube 55 having a predetermined length is drawn out of the die hole 50. At this time, a press-fitting chamber 64 surrounded by the pressurizing piston 58, the die 51, and the cylinder main body 57 is formed in the cylinder main body 57.
Fill. In order to fill the powdery brazing material 70, an opening that can be opened and closed is formed in a portion near the die 51 on the peripheral wall of the cylinder body 57, and the powdery brazing material 70 is filled from the charging hole. It is preferable to adopt a structure in which the charging hole can be closed by a lid or the like.

When the powdered brazing material 70 is filled in the press-fitting chamber 64, the heating device 60 is operated to heat the powdered brazing material 70 to a temperature slightly lower than its melting point (a temperature lower by about 10 ° C. to 30 ° C.). The powdered brazing material 70 is preheated, and the pipe body 60 is pulled out of the die 51 from this state, and at the same time, a fluid pressure is applied to the pressurizing chamber 66 to move the pressurizing piston 58 to the die 51 side. Press with pressure.

The powdered brazing material 70 used here may be mixed with a desired amount of flux in advance. However, when the flux is mixed, the heating temperature of the powdered brazing material 70 is set to the melting point of the powdered brazing material 70 so that the flux does not fly due to heating and the components contained in the flux do not diffuse to the tube body side. It is preferable to set the temperature to such a degree that the powdered brazing material 70 is softened at a lower temperature. When the flux is not added to the powdered brazing material 70, the powdered brazing material 70 may be heated to a temperature at which the powdered brazing material 70 is partially melted.

By the above operation, the pipe 55 is inserted into the die hole 5.
In addition, the powder brazing material 70 in the press-fitting chamber 64 can be compacted to the outer peripheral portion of the tube 55 and the brazing material layer 71 can be formed on the outer peripheral portion of the tube 55 at the same time. 55
The brazing material cladding tube 72 having the cross-sectional structure shown in FIG. In addition, the thickness of the brazing material layer 71 covering the pipe 55 may be about 10 to 20% of the thickness of the pipe 55 in the case of use for a heat exchanger or the like. When the thickness is about 3 to 5 mm, the thickness of the brazing material layer 71 is preferably about 0.3 to 0.5 mm.

In the above-described manner, the brazing material layer 7
In the case of forming 1, since the powdered brazing material 70 is compacted and adhered to the outer peripheral portion of the pipe 55 without completely melting, when the Al-Si alloy is used as the brazing material, Si contained in the brazing material is reduced. There is no risk of diffusion to the tube 55 side.
Here, if Si diffuses toward the pipe body 55 side, when the brazing filler metal pipe 72 is used as a tube for a heat exchanger and is placed in a corrosive environment, pitting is likely to occur, which may cause a problem in corrosion resistance. There is. From these facts, in the method of the present embodiment in which the unfused and heated brazing material is condensed and pulled out to the outer peripheral portion of the tube 55, unnecessary elements in the brazing material are not thermally diffused to the tube 55 side without heat diffusion. Layer 71 can be formed.

The brazing material cladding tube 72 thus obtained
Can be used as a tube for a heat exchanger by brazing to a fin. Then, when brazing to the fins, since the brazing material layer 71 is provided on the outer surface, the fins are brought into a heating furnace in an assembled state where they are in contact with the fins, and heated in the heating furnace to form a portion in contact with the fins. By partially melting the brazing material layer 71, the fins and the brazing material cladding tube 72 can be joined by brazing. At this time, since the brazing material layer 71 is uniformly formed on the entire outer surface of the brazing material cladding tube 72, brazing can be surely performed at the portion where the brazing material is assembled with the fins.

Next, when a brazing material cladding tube is manufactured by the manufacturing apparatus shown in FIGS. 1 and 2, in addition to the powdery brazing material as a material to be charged into the press-fitting chamber 64, zinc powder is added to the above-mentioned flux. You may mix. If the brazing material layer 71 is formed by adding the flux to the powdered brazing material, a predetermined amount of flux is preliminarily mixed into the brazing material layer 71. There is no need to apply a separate flux to the substrate. If zinc powder is mixed with the powdered brazing material and zinc is added to the brazing material layer 71, the brazing material cladding tube 72 is used as a tube of the heat exchanger, and the cooling water or water droplets are always adhered. Even when used in an environment, the brazing material layer containing zinc 7
A sacrificial anticorrosion effect of actively corroding 1 to prevent corrosion of the tube 55 itself can be imparted to the brazing material layer 71, and an anticorrosion effect can be imparted to the tubes of the heat exchanger.

The brazing material cladding tube 72 of this embodiment has a seamless tube 55 inside, and is used as a tube for a heat exchanger. Because there is no seam joint,
Corrosion and leak that are likely to occur at the joint can be eliminated.

On the other hand, as shown by a two-dot chain line in FIG. 1, a plug 90 may be provided inside the tubular body 55 located inside the die hole 50, and the drawing may be performed. By providing the plug 90, a drawing process in which the wall thickness of the tube 55 is made more uniform can be performed, and even a tube having a small wall thickness can be easily drawn.

FIG. 3 shows a cross-sectional structure of a second embodiment of a brazing material cladding tube manufacturing apparatus according to the present invention. The manufacturing apparatus E of the second embodiment is similar to the manufacturing apparatus of the first embodiment. D
Although the configuration is almost the same as that of the first embodiment, the driving mechanism of the pressure piston 58 is different. Other configurations are the same as those in the first embodiment, and thus the same portions are denoted by the same reference numerals and description thereof will be omitted. The manufacturing apparatus E according to the second embodiment differs from the manufacturing apparatus D according to the first embodiment in that hydraulic pressure is not directly introduced into the cylinder body 57, but a plurality of auxiliary cylinder devices 40 are provided outside the cylinder body 57. Provided,
The piston rod 41 of each auxiliary cylinder device 40 is provided so as to penetrate the rear outer wall of the cylinder device 57, and the pressure piston 5 is
8 can be pressed to the die 51 side.
Each auxiliary cylinder device 40 is installed on a pedestal (not shown), and the piston rod 41 is moved by hydraulic pressure from a hydraulic pump 42 connected to each auxiliary cylinder device 40 as shown in FIG.
Is configured to be able to be moved in the left-right direction.

In the manufacturing apparatus E of the second embodiment, the tube 55 is inserted into the die hole 50 as in the case of the manufacturing apparatus D of the first embodiment.
The pressurizing piston 58 is pressed toward the die 51 side, and the powdered brazing material is densely covered around the pipe 55, so that the brazing material layer 71 is formed as in the case of the manufacturing apparatus D of the first embodiment.
The brazing material cladding tube 72 with the attachment can be manufactured. In the device of the second embodiment, the auxiliary cylinder device 40 is provided outside the cylinder device 57. However, the auxiliary cylinder device 40 is formed smaller than that shown in the drawing and is built in the cylinder device 57. Of course, it is good.
The mechanism for pressing the pressurizing piston 58 of the cylinder device 57 toward the die is not limited to the auxiliary cylinder device 40, but is particularly limited as long as it is a device that can generate pressure and press the pressurizing piston 58. is not.

FIG. 4 shows a cross-sectional structure of a third embodiment of the brazing material cladding tube manufacturing apparatus according to the present invention. The manufacturing apparatus F of the third embodiment differs from the manufacturing apparatus of the first embodiment. D
Although the configuration is substantially the same as that of the first embodiment, the inner diameter of the die hole 50 is different. Other configurations are the same as those in the first embodiment, and thus the same portions are denoted by the same reference numerals and description thereof will be omitted. The manufacturing apparatus F of the third embodiment differs from the manufacturing apparatus D of the first embodiment in that the die holes 50
The inner diameter of the die hole 50 'of the die 51 of the third embodiment is the same as that of the die hole 5 of the device of the first embodiment.
The inner diameter of the pipe 55 is slightly larger than the inner diameter of the pipe 55, and the outer diameter of the pipe 55 is not reduced without reducing the diameter of the pipe 55 when coating the brazing material coating layer 71 on the pipe 55. It is configured such that only the brazing material coating layer 71 can be densely coated on the outer peripheral surface of the tube 55 by passing through.
As in the case of the manufacturing apparatus D of the first embodiment, the manufacturing apparatus F of the third embodiment includes a pipe 55 in the die hole 50 '.
At the same time as the pressurizing piston 58 is
Then, the powdered brazing material is pressed and coated around the pipe 55 to form the brazing material cladding tube 72 with the brazing material layer 71 in the same manner as in the case of the manufacturing apparatus D of the first embodiment. be able to.

FIG. 6 shows another example of a tube used as a brazing material cladding tube. A tube 75 of this embodiment has a plurality of grooves formed on the outer peripheral surface. Here, the shape of the groove formed in the tubular body 75 may be a groove 76 having a triangular cross section, a flat groove 77 having a rectangular cross section, or a groove having a W cross section. The groove 78 may be a continuous groove, or the groove 79 may have a round cross section (the convex portions between the grooves 79, 79 may have a round shape). FIG. 6 shows four types of these grooves collectively for the sake of simplicity of description. However, a plurality of grooves having the same shape may be formed at predetermined intervals in the circumferential direction in a normal pipe. FIG. 7 shows another example of a flat type brazing material cladding tube used as a tube, and a tube 85 of this example has a plurality of grooves formed on the outer peripheral surface. Here, the shape of the groove formed in the tube body 85 may be a groove 86 having a triangular cross section, a flat groove 87 formed of concave and convex portions having a rectangular cross section, or a groove 88 (groove) having a round cross section. The projections 88, 88 may have a round shape. Although three types of these grooves are collectively described in FIG. 7 for simplicity of description, a plurality of grooves of the same shape may be formed at regular intervals in a circumferential direction in an ordinary pipe.

FIG. 8 shows still another example of a flat type brazing material cladding tube used as a tube.
Reference numeral 9 denotes a plurality (five in the example shown in FIG. 8) of partition walls 8 inside.
9a is formed, and a plurality of grooves are formed on the outer peripheral surface as in the case of the tube body 85 shown in FIG. Here, the shape of the groove formed in the tube 89 is
A groove 86 having a triangular cross section may be used, a groove 87 having a flat cross section formed of concave and convex portions having a rectangular cross section, or a groove 8 having a round cross section may be used.
8 is acceptable. In FIG. 8, three types of these grooves are collectively described for simplicity of description. However, a plurality of grooves having the same shape may be formed at predetermined intervals in a circumferential direction in a normal pipe.

Using the grooved tube having the structure shown in FIG. 6, FIG. 7, or FIG. 8, a brazing material layer is formed on the surface of the tube by the manufacturing apparatus shown in FIG. 1, FIG. 2, FIG. 3, or FIG. Thus, a brazing material cladding tube can be obtained. The brazing material cladding tubes obtained here form a brazing material layer in the grooves of the respective pipes in a compacted manner or adhere to the brazing material, so the brazing material layer is heated and melted in a heating furnace during brazing, and the fins are brazed. Even after this, the height of the protrusion existing between the plurality of grooves does not change. Therefore, the outer dimensions of the tubular body do not change even after brazing, so that it is not necessary to set the mounting dimensions in consideration of the melting amount of the brazing material layer when assembling the heat exchanger. Can be easily set. Therefore, there is an effect that a heat exchanger having accurate dimensions can be easily assembled. Further, since the brazing material is disposed around the inside of the groove, the brazing material having a thickness and an amount corresponding to the number and width of the groove can be accurately provided on the outer periphery of the tube.

The dimensions of the various grooves are preferably in the ranges described below with reference to FIG. As shown in FIG. 9, when the thickness of the tube is t, the width of the groove 77 formed on the outer peripheral surface of the tube is W, and the depth of the groove is h, h / t is set to 0.2 or less. , W / h in the range of 1 to 1,000. Also, when using a groove 76 having a triangular cross section as shown in FIG. 9, the same dimensional ratio can be obtained. If the width and depth of the groove are within these ranges, an appropriate amount of brazing material can be given to the brazing clad tube, which will be appropriate when the fin and brazing clad tube are assembled as a heat exchanger. It can be a material quantity. If the value of W / h is 1000,
As shown in FIG. 10, the height of the protrusion between the grooves (in other words, the depth of the groove 74) is 1 mm with respect to the concave groove 74 having a width of 1 m. 74 is acceptable.

[0042]

As described above, according to the method for manufacturing a brazing filler metal cladding tube of the present invention, the diameter of the tube is reduced by the die hole, and at the same time, the molten state around the peripheral portion of the tube is not heated or half. Since the brazing material in the molten state is press-fitted to cover the brazing material layer around the tube, a brazing material clad tube having the tube and the brazing material layer can be obtained. Also, unlike the conventional method, in which the brazing material is applied together with the binder, the brazing material layer can be directly coated on the outer peripheral portion of the tube without using a binder, so that unnecessary gas generation accompanying the vaporization of the binder during brazing is prevented. It is possible to provide a brazing material cladding tube that does not occur. According to this method, even if the brazing material is made of a material having a lower melting point than the tubular body, the tubular body is reduced in diameter by plastic working, and the brazing material is surrounded by an unmelted state or semi-melted state. Since the brazing material can be adhered in a pressurized state, the brazing material layer can be coated on the outer peripheral portion of the tube without losing the brazing material and diffusing the brazing material component toward the tube.

By using a seamless pipe made of aluminum or aluminum alloy as the pipe, a brazing material clad pipe having a clad structure that does not have a seam joint, which is provided in an electric resistance welded pipe, can be obtained. This brazing material cladding tube can be used as a tube for a heat exchanger, and when used as a tube for a heat exchanger, the brazing material layer coated on the tube can be used for joining with the fins.

If a plurality of grooves are provided in the circumferential direction of the outer peripheral surface of the tube, the grooves can be securely filled with a brazing filler material. Therefore, when the thickness of the tube is t, the width of the groove is W, and the depth of the groove is h, h / t
Is 0.2 or less and W / h is in the range of 1 to 1,000, so that the outer peripheral portion of the tubular body can be coated with a necessary and sufficient amount of brazing material. Also, when the brazing material layer is compacted and filled in the groove on the peripheral surface of the tube, even when the brazing material is melted and brazed at the time of brazing, the outer diameter of the tube other than the groove does not change. The outer diameter of the tube does not change before and after. Therefore, when a brazing material cladding tube is applied to a tube for a heat exchanger and fins are brazed to the tube, the tubes and fins for the heat exchanger are assembled and the brazing material is heated and melted in a heating furnace to braze. However, since the mounting position of the fins with respect to the tube does not change, the heat exchanger can be assembled without considering the variation during brazing, and the heat exchanger assembly design can be simplified. it can.

Next, the manufacturing apparatus of the present invention is provided with a die and a cylinder device, and the aluminum or aluminum alloy tube is reduced in diameter by the die, and at the same time, the aluminum alloy brazing material in the unmelted heated state or semi-molten state by the cylinder device. Can be applied to the outer peripheral portion of the tubular body. On this occasion,
Even if the brazing material is made of a material having a lower melting point than the tube, the tube can be reduced in diameter by plastic working, and the brazing material can be adhered to its surroundings in an unfused state or a semi-molten pressure state. Therefore, the brazing material layer can be coated on the outer peripheral portion of the tube without dispersing the brazing material component toward the tube without losing the brazing material.

Further, in the manufacturing apparatus according to the present invention, the pressing mechanism presses the pressurizing piston provided on the cylinder body, and the pressurizing piston causes the powdery brazing material of aluminum or aluminum alloy to pass through the die. By press-fitting, the brazing material layer can be coated simultaneously with the withdrawal of the tube.

In these manufacturing apparatuses, the flux or the zinc powder can be mixed with the brazing material layer coated on the pipe body by making it possible to freely fill the flux or the zinc powder in addition to the aluminum alloy brazing material. If the flux is added to the brazing material, it is not necessary to separately apply a flux when brazing the brazing material drawing tube to another member, and the brazing workability can be improved. In addition, if zinc is added to the powdered brazing material, the brazing material layer containing zinc can be coated on the outer periphery of the tube, so that the tube can be used as a tube for a heat exchanger and used in a corrosive environment. In this case, the brazing material layer can be selectively corroded to impart a sacrificial anticorrosion effect to the corrosion of the pipe body to the brazing material layer. Further, by adding an appropriate binder to the brazing material, the brazing material layer can be coated on the outer peripheral portion of the tubular body with a stronger fixing force, so that a material that is difficult to peel off in a subsequent processing step can be provided.

[Brief description of the drawings]

FIG. 1 is a first view of an apparatus for manufacturing a brazing material cladding tube according to the present invention.
Sectional drawing which shows the state which is manufacturing the brazing material cladding tube using embodiment.

FIG. 2 is a first view of a brazing material cladding tube manufacturing apparatus according to the present invention.
Sectional drawing which shows embodiment.

FIG. 3 shows a second embodiment of the brazing material cladding tube manufacturing apparatus according to the present invention.
Sectional drawing which shows embodiment.

FIG. 4 shows a third embodiment of the brazing material cladding tube manufacturing apparatus according to the present invention.
Sectional drawing which shows the state which is manufacturing the brazing material cladding tube using embodiment.

FIG. 5 is a sectional view of a brazing material cladding tube manufactured from the state shown in FIG. 1;

FIG. 6 is a view showing various examples of a shape of a groove formed on an outer peripheral portion of a tubular body used for manufacturing a brazing material cladding tube according to the present invention.

FIG. 7 is a view showing various examples of a shape of a groove formed on an outer peripheral portion of a tubular body used for manufacturing a flat brazing material clad tube according to the present invention.

FIG. 8 is a view showing various examples of a shape of a groove formed on an outer peripheral portion of a pipe used for manufacturing a brazing filler metal pipe formed of a flat multi-hole pipe according to the present invention.

FIG. 9 is a view showing an example of the relationship between the interval and the size of grooves formed in the outer peripheral portion of a tube used for manufacturing the brazing material cladding tube according to the present invention.

FIG. 10 is a view showing another example of the relationship between the intervals and the dimensions of the grooves formed in the outer peripheral portion of the tubular body used for manufacturing the brazing material cladding tube according to the present invention.

FIG. 11 is a side view showing an example of a generally used parallel flow heat exchanger.

FIG. 12 is a side view showing an example of a serpentine heat exchanger used as an example.

FIG. 13 is a cross-sectional view showing an example of a commonly used brazing sheet having a two-layer clad structure.

FIG. 14 is a cross-sectional view showing an example of a commonly used brazing sheet having a three-layer clad structure.

FIG. 15 is a cross-sectional view showing an example of a tube configured using a brazing sheet.

FIG. 16 is a cross-sectional view showing another example of a tube configured using a brazing sheet.

FIG. 17 is a side view showing an assembled state of a fin and a tube configured by using a brazing sheet.

FIG. 18 is a perspective view of a tube configured using a brazing sheet.

[Explanation of symbols]

A, B: heat exchanger, D: manufacturing device, 50: die hole, 51: die, 52: cylinder device, 53: inlet, 54: outlet , 55 ... tubular body, 57 ... cylinder body, 58 ... pressing piston, 59 ... pressing mechanism, 60 ...
・ Heating device, 63 ・ ・ ・ Introduction part, 64 ・ ・ ・ Press-fitting chamber, 65 ・ ・ ・ Insertion hole, 66 ・ ・ ・ Pressure chamber, 68 ・ ・ ・ Fluid supply device, 70 ・ ・ ・
Powdered brazing material, 71 ... brazing material layer, 72 ... brazing material cladding tube, 76, 77, 78, 79 ... groove, 86, 87, 88
··groove.

Claims (9)

[Claims] 1. A room temperature or heated state in which a metal tube is inserted into a die hole having an inlet portion and an outlet portion, and is not melted around a peripheral portion of the tube inserted into an inlet portion of the die hole. Alternatively, a brazing material clad tube comprising supplying a semi-molten brazing material and coating the brazing material layer around the tube to form a brazing material clad tube including the tube and the brazing material layer. Manufacturing method. 2. A seamless pipe, a perforated pipe obtained by extrusion molding from aluminum or an aluminum alloy, or an electric resistance welded pipe obtained by processing a plate material of aluminum or an aluminum alloy as a pipe inserted into the die hole. The method for producing a brazing material clad tube according to claim 1, wherein any one of the following is used. 3. The method according to claim 1, wherein at least one of a flux and a binder is mixed with the brazing material to form a brazing material layer. 4. A normal temperature state or a non-melted heated state when a flux is mixed with the brazing material, and a normal temperature state or a semi-molten state when a flux is not mixed with the brazing material. The brazing material cladding tube according to claim 1 or 2, wherein the brazing material is supplied. 5. The method for producing a brazing material clad tube according to claim 1, wherein a tube grooved on the outer periphery is used as the tube inserted into the die hole. 6. When the thickness of the tube is t, the width of a groove formed on the outer peripheral surface of the tube is W, and the depth of the groove is h,
The method according to any one of claims 1 to 4, wherein / t is 0.2 or less and W / h is in a range of 1 to 1000. 7. A die having a die hole having an inlet portion and an outlet portion, and a cylinder device connected to the inlet portion side of the die hole and integrated with the die, wherein the cylinder device is A tube made of aluminum or an aluminum alloy is configured to be insertable and the tube can be introduced into the die hole of the die, and for brazing the tube around the outer periphery of the tube inserted into the cylinder device at the entrance of the die hole. A press-fitting portion capable of press-fitting the aluminum alloy powder brazing material is provided, and a heating device capable of heating the aluminum alloy powder brazing material to a heating temperature lower than its melting point is provided in the cylinder device. Manufacturing equipment for brazing material cladding tubes. 8. A die having a die hole having an inlet and an outlet, and a cylinder device connected to the inlet of the die hole and integrated with the die, wherein the cylinder device is A cylinder body integrated with a die by connecting a press-fitting chamber provided inside to a die hole inlet side, and an aluminum press-fitting chamber formed inside the cylinder body from outside the cylinder body and formed on the rear side of the cylinder body. Or, an introduction portion for introducing an aluminum alloy tube and introducing the tube to the inlet side of the die hole, and an insertion hole provided in the cylinder body and through which the tube is inserted, the inside of the cylinder body is provided. A pressurizing piston movably provided in the cylinder body along the pipe introduced into the cylinder body and the inner wall of the cylinder body, and a rear portion of the pressurizing piston in the cylinder body And a pressing mechanism that presses the pressurizing piston toward the die in the cylinder main body.The cylinder main body inner surface is closer to the die than the pressurizing piston in the cylinder main body. A pressurizing chamber is formed freely by being surrounded by the pressurizing piston, the tube, and the die, and the pressurizing chamber can be freely filled with an aluminum alloy powder brazing material for coating the tube. An apparatus for manufacturing a brazing material cladding tube, wherein a heating device is provided outside the cylinder body so as to be capable of heating the aluminum alloy powder brazing material filled in the pressurizing chamber to a temperature lower than its melting temperature. 9. The apparatus according to claim 7, wherein the press-fitting chamber is freely filled with a flux, a zinc powder, or a binder in addition to the aluminum alloy powder.