JPH10272559A - Method of joining pipes to the expanded section of roll bond panel type heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of joining a pipe to a swelling portion of a roll bond panel type heat exchanger which can be joined by brazing in a state where a pipe is inserted into an end opening of the swelling portion. SOLUTION: Metal pipes 2a, 2b are provided at end openings 11a, 11b of an expanded tube portion 10 of a roll bond panel type heat exchanger 1.
When the joints are connected in a communicating state, the flux 3 between the inner surfaces of the openings 11a and 11b and the outer peripheral surfaces of the ends of the pipes 2a and 2b.
So that the ends of the pipes 2a and 2b are opened 11a,
The pipes 2a, 2b are joined to the end openings 11a, 11b of the inflatable tube 10 by inserting the brazing material 4 in the openings 11a, 11b or in the vicinity thereof and performing brazing. .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for joining a pipe to an expanded portion of a roll bond panel type heat exchanger used as an evaporator of a refrigerator.

[0002]

2. Description of the Related Art The roll bond panel type heat exchanger is a two-piece metal such as aluminum (including its alloy) having a pattern drawn on an overlapped surface by a pressure-resistant agent. A heat exchanger in which a circuit for refrigerant conduction is formed by applying a swelling pressure to a part that has not been squeezed by a squeezing preventive agent after the plate is squeezed by rolling or the like to form an swelled tube portion along the pattern It is.

In the roll bond panel type heat exchanger,
It is necessary to join a metal pipe for connecting to an external refrigerant circuit to the end opening of the expanded tube portion. Conventionally, as shown in FIG. 4, a pipe (92) is joined to an end opening (91) of a bulging portion (90), and a pipe shape for preventing melting into the inside of the joined portion. The stainless steel sleeve (93) is placed in a state of being inserted in both the opening (91) and the pipe (92), and the butted portion is welded with argon.

[0004] However, the joining of pipes by the argon welding must be performed manually by a skilled worker, which is extremely difficult to automate, and the production efficiency is not good.
In addition, a shortage of skilled workers for performing the joining operation is expected in the future, and a new joining method corresponding to automation has been desired.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has been made in consideration of the above problem. Therefore, the expansion of a roll bond panel type heat exchanger in which a pipe can be easily joined to an end opening of an expansion tube without skill is required. It is an object to provide a method for joining a pipe to a pipe.

[0006]

In order to solve the above-mentioned problems, a method of joining a pipe to a bulging portion of a roll-bonded panel heat exchanger according to the present invention is described in which a pattern is drawn on a superimposed surface with a pressure-resistant agent. The two expanded metal plates are press-bonded, and the expanded metal plate is expanded along the pattern to form an expanded tube portion for refrigerant conduction. When joining a metal pipe in a communicating state to the end opening of the pipe, the end of the pipe is connected to the opening so that the flux is interposed between the inner surface of the opening and the outer peripheral surface of the end of the pipe. It is characterized in that the pipe is joined to the opening at the end of the bulging portion by inserting and brazing by placing a brazing material in or near the opening.

In the above joining method, brazing is performed with a brazing material disposed at or near the opening in a state where the flux is interposed between the inner surface of the end opening of the expanded tube and the outer peripheral surface of the end of the pipe. Therefore, the molten brazing material enters the gap between the pipe and the expanded pipe portion without being repelled by the pressure-resistant agent by the action of the flux, fills the gap, and opens the end opening of the expanded pipe section. Can be joined in a state where a pipe is inserted.

Therefore, if this joining method is adopted,
For example, since the pipe can be joined to the end opening of the expanded part of the roll bond panel type heat exchanger by using any brazing method such as torch brazing or high frequency brazing, the joining work is easy. It is also possible to respond to automation.

Further, according to this method, since the brazing material is not repelled by the remaining pressure-blocking agent and does not enter the deep portion of the expanded tube portion where no flux is present, the deep portion of the expanded tube portion is formed. No contamination by brazing material.

[0010]

Next, an embodiment of the present invention will be described with reference to the drawings.

In the roll bond panel type heat exchanger (1) according to this embodiment, as shown in FIG. 3, a hexagonal section (10) having a hexagonal cross section is provided in a predetermined pattern inside an aluminum plate. Things. The manufacturing method of the roll bond panel heat exchanger (1) is generally as follows. That is, a bonding agent made of graphite is printed in a predetermined pattern on a superposed surface of two aluminum plates by using a screen printing technique. Then, the two aluminum plates are pressed by rolling. Since the printed portion of the anti-compression agent is not press-bonded, a high pressure is applied to this portion to form a bulging portion (10) along a pattern to manufacture the heat exchanger (1). In addition, heat exchanger (1)
At one end in the longitudinal direction, end opening portions (11a) and (11b) of the inflated tube portion (10) are formed so as to protrude, and the end openings (11a) and (11b) are provided with a refrigerant described later. The entrance / exit pipes (2a) and (2b) are joined. The end openings (11a) and (11b) are expanded to have a circular cross section so that the pipes (2a) and (2b) can be inserted.

In this heat exchanger (1), the inlet pipe (2)
The refrigerant introduced from one end opening (11a) through a) passes through the inside of the expansion tube (10) functioning as a refrigerant circuit, and exits from the other end opening (11b) through the outlet pipe (2b). ).

The entrance / exit pipes (2a) and (2b)
Are the end openings (11a) (11) of the inflated tube (10).
This is an aluminum L-shaped pipe having an outer diameter that can be inserted into b). The other ends of the pipes (2a) and (2b) can be connected to an external refrigerant circuit.

The pipes (2a) and (2b) are formed as follows.
1b).

That is, as shown in FIG. 1, a ring-shaped brazing material (4) is arranged on the outer periphery of the pipes (2a) (2b). The position of the brazing material (4) is determined by the pipe (2a)
(2b) is a position where it comes into contact with the end face of the inflated tube (10) in a state where it is inserted and arranged in the end openings (11a) and (11b).

The type of the brazing material (4) is not particularly limited, but in this embodiment, since the heat exchanger (1) and the pipes (2a) and (2b) are made of aluminum, Al- It is preferable to use a Si-based brazing material.

Next, a flux (3) is applied to the outer peripheral surface from the tips of the pipes (2a) and (2b) to the brazing material (4).

As the flux (3), any flux such as a chloride flux or a fluoride flux used for brazing may be used, but a non-corrosive fluoride flux is preferably used. In the case of this embodiment, the flux (3), which is obtained by mixing a fluoride-based flux composed of a complex of aluminum fluoride and potassium fluoride with water and emulsifying the same, was applied to the position.

Then, the pipes (2a) and (2b) coated with the flux (3) are connected to the opening (11) of the expanded tube (10).
a) Inserted into (11b), and a flux was interposed between the inner surfaces of the openings (1a) and (1b) and the outer peripheral surfaces of the ends of the pipes (2a) and (2b).

Next, as shown in FIG. 2, the end openings (11a) and (11b) of the inflated tube (10) are heated by an automatic brazing device using a torch (5). This heating causes the flux (3) to melt, followed by the brazing material (4)
Melts. It is presumed that the melting of the flux (3) removes the anti-pressing agent present on the inner peripheral surfaces of the openings (11a) and (11b), and the molten brazing material (4)
Is the opening (11a) without being repelled by the anti-pressing agent.
(11b) and the pipes (2a) and (2b) are filled. Further, since the flux (3) is not interposed in the deep portion of the expanded tube portion (10) into which the pipes (2a) and (2b) are not inserted, the anti-compression material remains on the inner peripheral surface as it is. The brazing material (4) is repelled and cannot enter any further.

As described above, the openings (11a) (11
By cooling and solidifying the brazing material (4) filled between the inner surface of the b) and the outer peripheral surface of the end of the pipe (2a) (2b), the end opening (11a) ( 11b)
The pipes (2a) and (2b) are joined to each other in a communicating state.

As described above, this embodiment uses a general torch brazing apparatus to open the end openings (1a) (1) of the expansion tube (10) of the roll bond panel type heat exchanger (1).
The pipes (2a) and (2b) can be joined very easily to b). Therefore, there is no need for skill in the joining operation, and automation can be easily dealt with.

Also, the brazing material (4) has an opening (11a).
(11b) Since it does not enter deeper, the inside of the inflatable tube (10) is not stained with the brazing material.

It should be noted that the present invention is not limited to the above-described embodiment, but may take any form within the scope described in the claims. For example, in this embodiment, the brazing material (4) is melted by an automatic brazing device using a torch (5), but brazing may be performed by high-frequency brazing or other brazing methods. Further, the brazing operation may be performed not only automatically but also manually.

[0025]

According to the present invention, as described above, the present invention relates to a roll bond panel type heat exchanger in which a flux is interposed between an inner surface of an end opening of an expanded tube and an outer peripheral surface of an end of a pipe. Because brazing is performed, by the action of the flux, the dissolved brazing material can be filled in the gap between the pipe and the expanded tube portion without being repelled by the anti-pressing agent,
The pipe can be joined to the end opening of the inflatable tube in an inserted state.

Therefore, it is possible to adopt a brazing method that can easily cope with automation, such as torch brazing or high-frequency brazing, which has been used in the production of other heat exchangers, for example. Can be easily performed from argon welding.

Further, since the brazing material cannot enter the expanded tube portion where there is no flux due to the remaining pressure-resistant adhesive, the inside of the expanded tube portion can be prevented from being contaminated by the brazing material.

[Brief description of the drawings]

FIG. 1 is a view for explaining one embodiment of the present invention, and is a cross-sectional view showing a state before a pipe is inserted into an end opening of a bulging portion.

FIG. 2 is a sectional view showing a state where the pipe is brazed after insertion.

3A and 3B are diagrams showing a roll bond panel type heat exchanger to which pipes are joined, wherein FIG. 3A is a front view, and FIG. 3B is a cross-sectional view taken along line III-III shown in FIG.

FIG. 4 is a cross-sectional view showing a state in which pipes are joined by conventional argon welding.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Roll bond panel type heat exchanger 2a, 2b ... Pipe 3 ... Flux 4 ... Brazing material 10 ... Expansion part 11a, 11b ... Opening

Claims (1)

[Claims] 1. After two metal plates, each of which has a pattern drawn thereon, are pressure-bonded to the overlapping surface by a pressure-resistant agent, the metal plates are expanded along the pattern, so that a refrigerant-conducting expansion portion is formed. When joining a metal pipe to the end opening of the expanded tube portion of the formed roll bond panel heat exchanger in a communicating state, a gap between the inner surface of the opening and the outer peripheral surface of the end of the pipe is formed. By inserting the end of the pipe into the opening so that the flux is interposed between the opening and the brazing by arranging the brazing material in or near the opening, the pipe is inserted into the opening at the end of the expanded tube. A method for joining pipes to a bulging portion of a roll bond panel type heat exchanger, characterized in that: