JPH0655261A - Brazing method - Google Patents

Abstract

PURPOSE:To make a brazing quality at each brazing part uniform and appropriate by arranging a heat absorbing jig with fin at a brazing part hard for raising temp. and brazing at one time. CONSTITUTION:A heat absorbing jig 9 covers all the upper surface of a coupling member 6 and has a heat conduction surface 9a coming in contact with a coupling member as well as a heat absorbing fin 9b, which is formed by lowering, etc., that is a skived fin. The heat absorbing jig 9 is arranged on the upper surface of the coupling member 6 and a heat exchanger assembly is charged in a heat furnace for brazing, executing botch brazing under the prescribed brazing temp. by means of vacuum brazing, flux brazing, etc. Heat absorption of the coupling member 6 is accelerated by heat absorbing effect of the heat absorbing jig 9, raising temp. at the same pace with temp. rising speed of other heat exchanger constituting members. By this method, it produces uniform and appropriate brazing joining conditions.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brazing method for various metal structures such as a car cooler and an aluminum heat exchanger for room air conditioners.

[0002]

2. Description of the Related Art For example, as a heat exchanger for a car cooler,
Recently, a multi-flow type or parallel flow type with a basic structure in which a pair of aluminum hollow headers are connected in communication with both ends of multiple aluminum tubes and aluminum corrugated fins are arranged between the tubes. Aluminum heat exchangers, referred to as, tend to be used favorably.

In the manufacture of this heat exchanger, generally, tubes are arranged in parallel at predetermined intervals, and a pair of hollow headers made of an aluminum brazing sheet is inserted at both ends of the tubes, which are formed on the peripheral side walls. Insert the tube end into the hole to combine them into a fitted state, further dispose fins made of aluminum brazing sheet between the tubes, and assemble other accessory parts, and then heat exchanger assembly in this temporarily assembled state. Is placed in a heating furnace for brazing, and batch brazing is performed to integrally bond the whole.

By the way, in this heat exchanger, a refrigerant inlet pipe and an outlet pipe made of aluminum are connected to the header so as to allow a refrigerant to flow therethrough, and a mass and a weight thereof are large at their tips. A structure in which a flange-coupling type coupling member made of aluminum for connecting an external pipe in the form of a block having a large heat capacity is sometimes used.

In the heat exchanger having such a structure, an inlet pipe and an outlet pipe made of an electric brazing pipe made of an aluminum brazing sheet are assembled in a state of being communicated with the header, and external pipes are connected to the tips of these connecting pipes. The aluminum joint member is assembled, and when the heat exchanger assembly is collectively brazed, the header and the inlet pipe, and the inlet pipe and the joint member are collectively brazed.

[0006]

However, in the heat exchanger having the block lump-shaped joint member having a large heat capacity as described above, during brazing, the portion to be brazed between the joint member and the inlet pipe rises. The temperature rate becomes relatively slower than the rate of temperature rise in the parts to be brazed such as tubes and headers and tubes and fins.Therefore, the brazing performance of the brazing parts of the joint members and There is a problem in that the brazing performance of the brazing part is different, resulting in a quality difference between the brazing parts of the heat exchanger.

In particular, when proper brazing of a joint member that is difficult to heat up is attempted, the brazing material is diffused in the brazing portion of the tube or header where the temperature rises easily, and the strength of that portion is reduced and the corrosion resistance is high. Will be reduced.

For this reason, conventionally, the charging speed into the heating furnace, the temperature, etc. have also been adjusted for each type of structure to be collectively brazed, but this method only requires a lot of time and labor for setup change. However, there is a drawback that a sufficient effect is not always exhibited.

In view of the above-mentioned conventional problems, the present invention has a structure having a portion to be brazed having a high temperature rising rate and a portion to be brazed having a relatively slow temperature rising rate. It is an object of the present invention to provide a brazing method capable of collectively brazing each brazed part into a uniform and proper one in terms of quality.

[0010]

For the above object, the present invention is a brazing structure having a portion to be brazed having a high temperature rising rate and a portion to be brazed having a relatively slow temperature rising rate. A brazing method, wherein an endothermic jig having fins is arranged in a portion to be brazed having a slow rate of temperature rise or a region in the vicinity thereof, and the brazing is performed collectively under a predetermined brazing temperature. The attachment method is the main point.

[0011]

According to the above method, during the brazing, the heat-absorbing action of the heat-absorbing jig increases the rate of temperature rise in the portion to be brazed that is difficult to raise, so that the same temperature rise as that in the portion to be brazed that is easy to raise To do. Therefore, the temperature rising rates of the planned brazing portion where the temperature is likely to rise and the originally planned brazing portion where it is difficult to raise the temperature are uniform, and the brazing quality of each brazing portion is uniform and proper.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment in which the brazing method of the present invention is applied to manufacture of a heat exchanger for a multi-flow type air conditioner will be described with reference to the drawings. Needless to say, the brazing method of the present invention is not limited to the heat exchanger and is widely applied to the manufacture of various structures having brazing specifications.

In the heat exchanger shown in FIG. 2,
(1) ... is a flat tube, (2) ... is a fin, (3)
(3) is a header, (4) is a refrigerant inlet pipe, (5) is the same outlet pipe, and (6) is a joint member for connecting an external pipe. In addition, (7) is a side plate. Further, (8) is a partition member for partitioning the inside of the header (3) to allow the refrigerant to meander through the tubes (1) ...

The flat tube (1) is made of an aluminum extruded mold material, and as shown in FIG. 1 (a), the interior is divided into a plurality of chambers by partition walls to improve the pressure resistance. , So-called harmonica tube.
As the tube (1), an electric resistance welded pipe, a brazed pipe, or the like may be used in addition to the above-mentioned extruded pipe.

The corrugated fin (2) is a corrugated sheet material having a width substantially the same as the width of the tube (1) and cut and raised louvers, and the brazing material layer clad aluminum is used as the sheet material. A brazing sheet is used.

The headers (3) and (3) are cylindrical headers formed into a pipe shape by bending one aluminum brazing sheet having a brazing material layer clad on the outer surface or both surfaces in a state where both side edges are butted. Pipe (3a)
(3a), and an aluminum header cap (3b) (3b) as a lid that closes the upper and lower ends of the opening in a state of being externally fitted. The header pipe (3a) is provided with a circumferential slit-shaped tube insertion hole (3c) for inserting the end of the tube (1) on its peripheral wall, and a refrigerant inlet pipe insertion hole (3d). And the same outlet pipe insertion hole (3e) is provided. As the header pipe (3a), in addition to the brazing pipe as described above, an electric resistance welded pipe, an extruded pipe or the like may be used.

The refrigerant inlet pipe (4) and the outlet pipe (5) are
This is due to the electric resistance welded pipe made of aluminum brazing sheet.

The joint member (6) is a flange-coupling type member made of aluminum and has a large heat capacity and is in the form of a block and has a slower heating rate than other heat exchanger constituent members. An inlet pipe insertion hole (6a) is provided on the lower surface of the joint member (6).
And an outlet pipe insertion hole (6b) are provided, and a pair of connecting portions (6c) (6d) for connecting an external pipe are provided on the flat connecting flange surface of the upper surface.

In manufacturing the above heat exchanger, first, the respective heat exchanger constituent members are assembled in a temporary assembled state. That is, by inserting the headers (3) and (3) into both ends of the tubes (1) ... arranged in parallel, and inserting the ends of the tubes (1) into the tube insertion holes (3c), Combination,
Further, the corrugated fins (2) are inserted and arranged between the tubes (1). Furthermore, the refrigerant inlet pipe (4) and the outlet pipe (5)
The base end of the inlet pipe (4) and the outlet pipe (5) of the joint member (6) are inserted and fitted into the insertion holes (3d) (3e) of the header (3). Insertion holes (6a) (6b)
Insert and fit into. In addition, attach the side plate (7) and so on.

Then, the heat exchanger assembly is collectively brazed. In the above heat exchanger assembly, the joint member (6) is a member that is in the form of a block and is less likely to heat up than other heat exchanger constituent members.
The portion to be brazed between the joint member (6) and the inlet pipe (4) or the like is relatively less likely to heat up than the portion to be brazed to the tube (1) and the header (3) or the like. Therefore, the rate of temperature rise of the joint member (6) is increased so that the temperature of the inlet pipe (4) and the like of the joint member (6) to be brazed is made uniform with the rate of temperature rise of other parts to be brazed. For heat absorption jig (9)
To use.

This heat absorbing jig (9) has a heat conducting surface (9a) which covers the entire upper surface of the joint member (6) and is in contact therewith, and also has a heat absorbing surface formed by cutting and raising on the outer surface. The fins (9b), that is, skive fins, are provided.

The heat-absorbing jig (9) may be arranged in the temporary assembly structure only in order to perform the heat-absorbing function, or may be arranged in a self-jig state.
In addition to the heat absorption function, the structure may also have a temporary fixing function for components to be brazed. What is essential is that it has at least fins and has a heat absorbing function.

For brazing, the heat absorbing jig (9) is placed on the upper surface of the joint member (6), and the heat exchanger assembly is placed in a heating furnace for brazing, and the brazing temperature is adjusted to a predetermined value. Bottom, vacuum brazing, flux brazing, etc. are performed collectively by brazing. As a result, the whole is integrally joined and integrated.

During the brazing, heat absorption of the joint member (6) is promoted by the endothermic action of the heat absorbing jig (9), and the temperature is raised at a pace similar to that of other heat exchanger constituent members. I will do it. Therefore, there is no quality difference between the brazed portion of the joint member (6) and the inlet pipe (4) and the brazed portion of the tube (1) and the header (3), etc. With this, a proper brazing and joining state can be obtained.

Moreover, as described above, by disposing the heat absorbing jig (9) on the surface provided with the connecting portions (6c) (6d) for connecting the external pipes, the connecting portion (6c) is brazed during brazing. )
It is possible to prevent dirt from adhering to (6d) or its peripheral portion, and to carry out collective brazing while maintaining good quality of the connecting portions (6c) and (6d).

[0026]

As described above, according to the brazing method of the present invention, the endothermic jig having the fins is arranged at the brazing planned portion where the temperature rise is relatively difficult or the vicinity thereof, and the brazing temperature is set to the predetermined value. Since the batch brazing is performed under high temperature, the rate of temperature rise is made uniform between the part to be brazed that is easy to raise the temperature and the part to be brazed that is difficult to raise the temperature. Can be made uniform and proper.

[Brief description of drawings]

FIG. 1 is a front view of essential parts showing a temporary assembly state of a joint member in a heat exchanger.

FIG. 2A is a perspective view showing a tube, a header and the like in a separated state, and FIG. 2B is a perspective view showing a joint member, an inlet pipe, a heat absorbing jig and the like in a separated state.

3A and 3B show the entire configuration of a heat exchanger, FIG. 3A is a front view and FIG. 3B is a plan view.

[Explanation of symbols]

 9 ... Endothermic jig

Claims (1)

[Claims] 1. A brazing method for a structure, comprising a portion to be brazed having a high rate of temperature rise and a portion to be brazed having a rate of temperature rise relatively slower than that of the braze, wherein the rate of brazing is slow. A brazing method characterized by arranging an endothermic jig having fins in a portion to be brazed or a region in the vicinity thereof and performing collective brazing at a predetermined brazing temperature.