JPH054600B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing a laminated heat exchanger for use as an evaporator of a vehicle cooling system.

[Prior Art] A heat transfer medium has a structure in which a large number of flat tubes each having an inlet and an outlet for a heat transfer medium and having a flat thin plate shape are laminated and combined so that each outlet and inlet are connected to each other. In the industry, the laminated heat exchanger is the first type of heat exchanger.
It has a general structure as shown in Figure 0.
A in the figure is an individual flat tube, for example, two metal tank plates 1 and 2, which are much flatter than the pastry shell, are airtightly joined together. The flat tube A
The top part is expanded to provide a refrigerant output port B, and the refrigerant inlet/outlet holes 3 and 4 are connected to this port B.
There are holes on both sides in the flat direction. The inner cavity of the flat tube is divided into two sections by a partition wall provided at the center in the vertical direction, and the refrigerant flows in from the inlet at the upper end of one section and descends, passing through the notch at the lower end of the partition wall. The liquid flows through the other compartment, rises, and flows from the outlet at the upper end of this compartment to the inlet of the adjacent flat tube. Note that 1C is a group of protruding ribs for dividing the flow path of the refrigerant flowing inside the flat tube A into smaller sections.

Of the two tank plates, the flat tube A' located at the outermost side of the stacked flat tube A group is
The outer one is replaced with a short flat end plate 5 lacking a bulge.

As shown in FIG. 11, the method of installing refrigerant supply (or discharge) piping to this heat exchanger is as shown in FIG. Prepare a piping member C that is deformed into a shaped portion 50b, the end of which is hermetically sealed with an end plate 51, and a refrigerant supply (discharge) hole 52 is provided in the cylinder side wall surface.
With the refrigerant supply hole 52 of the piping member C aligned with the refrigerant inlet hole 6 of the end plate,
A method has been adopted in which the end plate 5 is sandwiched between the end plate 5 and a side plate 7, which is an outer wall plate of the heat exchanger, and which is placed outside the end plate 5, and then these three are joined by brazing.

[Problems to be solved by the invention] In the conventional heat exchanger assembly method as described above,
In addition to requiring troublesome processing to airtightly seal one open pipe end of the piping member C,
Depending on the method of transforming a round pipe into a square pipe, it is difficult to form the surfaces that come into contact with the end plate 5 and the side plate 7 into sufficiently smooth flat surfaces, and it is difficult to ensure airtightness. It was difficult to perform a brazing joint.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for manufacturing a heat exchanger that can simplify the work process as much as possible and also allow piping members to be brazed to the heat exchanger body airtightly and firmly.

[Means for Solving the Problems] In order to achieve the above object, the method for manufacturing a heat exchanger of the present invention includes a method for manufacturing a heat exchanger of the present invention, in which a large number of flat tubes constituting flow paths for a heat transfer medium are connected to each other. A method for attaching inlet and outlet piping for a heat transfer medium to a laminated heat exchanger having a structure in which the outlet and inlet of the heat transfer medium are connected to each other in a laminated manner, the method comprising: An arbitrary cross-sectional shape is formed between the end plate that is in contact with each of the end plates of both laminations, and a side plate that serves as an outer wall plate of the heat exchanger and is disposed outside the end plate. A short metal cylindrical joint member provided with a hole for installing the piping is sandwiched so as to surround the heat transfer medium inlet (outlet) provided in the end plate, and the end plate and side A method was adopted in which these three parts were joined by brazing by heating to a temperature higher than the melting temperature of the brazing filler metal that had been clad in advance on each surface of the plate.

[Function] In the above manufacturing method, a short cylindrical joint member is prepared by cutting a long metal cylinder having an arbitrary cross-sectional shape into a predetermined length, and this A hole for installing the output pipe of the heat transfer medium is provided on the cylindrical wall surface of the member, and the joint member is sandwiched in a predetermined position between the end plate and the side plate, the surfaces of which are covered with brazing filler metal. The two plates and the joint member are brazed together by heating above the melting point of the brazing material.

[Example] The method for manufacturing a heat exchanger of the present invention will be specifically described below with reference to the accompanying drawings. Fig. 1 is a front view of a heat exchanger as an evaporator for an automobile air conditioner, Fig. 2 is a sectional view taken along the line A--I of Fig. 1, and Fig. 3 is a partially enlarged sectional view of the right end of Fig. 1. , and FIG. 4 is an exploded perspective view showing the separated state of the end plate, side plate, joint member, and piping before brazing, where A is a flat tube and each flat tube is a As seen in the cross-sectional view of Figure 3, two tank plates 1 and 2 are formed into a skin shape in the middle of an extremely flat confectionery, for example, and their concave surfaces face each other. It is formed by brazing and joining together. B
is a bulge formed at the top end of the flat tube A and serves as a refrigerant inlet/outlet port, and is connected to the tank plate 1.
and molding simultaneously at the time of molding 2. Reference numeral 1a2a denotes a partition wall provided on tank plates 1 and 2, respectively, to vertically divide the flat tube A into two parts.The lower end part d of the partition wall lacks a wall and is divided into two compartments a and b. It forms a communication path for the internal space of the pipe. 3 and 4 are bulging portions B that serve as refrigerant inlet and outlet ports.
A refrigerant inlet hole and an outlet hole are provided on both flat sides of the refrigerant, and the inlet hole 3 of one flat tube A is connected to the outlet hole 4 of the adjacent flat tube A on one side of this flat tube, and the outlet hole The hole 4 is connected so as to communicate with the inlet hole 3 of the adjacent flat tube A on the other side. Further, a flange-like portion 1b2b is provided at the lower end of each flat tube A, and the lower ends of adjacent flat tubes are connected by brazing the adjacent flange-like portions 1b against each other. . Numerous ribs 1c and 2c are provided on one side of the tank plates 1 and 2, excluding the bulging portion B, and serve to subdivide the refrigerant flow path and improve the assembly strength of the flat tubes. There used to be. 11 is a corrugated fin sandwiched between adjacent flat tubes A for increasing the heat transfer surface area.

Among the flat plates A group that are laminated together, the flat plates A' located at the left and right outer ends are the tank plates located on the outer side of the two tank plates 1 or 2, as shown in Figure 3. is replaced with an end plate 5 that lacks the bulge B. A side plate 7 is disposed outside the end plate 5 at a certain distance and serves as an outer wall plate of the evaporator. Reference numeral 8 denotes a joint member which is sandwiched between the end plate 5 and the side plate 7 and joined together by brazing, and has a short metal cylinder shape. It is arranged at a position where it can surround the inlet (outlet) hole 6 of the. Reference numeral 12 denotes a pipe through which the refrigerant supplied from the receiver of the refrigeration system via the pressure reducing device is sent to the evaporator as a heat exchanger, and a joint 13 for connection to the refrigerant supply is installed at one end of the pipe. The other end is brazed to the joint member 8. Reference numerals 10 and 14 respectively designate pipes for discharging refrigerant from the heat exchanger and joints for connecting these pipes to the suction side pipe of the refrigerant compressor.

As shown in FIG. 4, the end plate 5 and the side plate 7 each have a bulge 5 for positioning the joint member 8 and increasing brazing strength.
a and 7a are formed by press molding. Reference numeral 15 denotes a hole for fitting the pipe 10 or 12, which is bored in the wall surface of the cylindrical joint member 8.

Next, a method of assembling an evaporator having the above configuration will be explained. Tank plates 1 and 2 as constituent materials of flat tube A have a plate thickness of 0.4 to 0.8.
For example, filler metal with a thickness of 10 to 12% of the thickness of the plate material is applied to both surfaces of an aluminum plate (JISA-3003, etc.)
Using A4004, A4104, etc., which has been clad in advance by melt plating or other methods, it is pressed and cut into the desired shape and dimensions.

End plate 5 is tank plate 1 or 2
It may be made of the same material as the soldering material, and it is also possible to clad the brazing material on both surfaces, and a bulge 5a with a height of 2 to 5 mm for positioning the joint member 8 is formed by a pressing method. At the same time, a refrigerant outlet hole 6 is bored in this bulging portion 5a.

The side plate 7 is made of an aluminum plate having a thickness of 0.5 to 2.0 mm, for example, A3003, and has a brazing material of 10 to 12% of the plate thickness, for example, on the surface (the side to be joined with the joint member 8).
Using a cladding of A4004, A4104, etc.
The positioning bulge 7a of the joint member 8 is formed by press working.

The joint member 8 is made by extruding aluminum and has a cross section of an arbitrary shape such as a rectangle or an ellipse as shown in the figure, and a wall thickness of 0.5 to 1.0 mm. It is created by cutting it into a cylindrical shape. Prior to or after the cutting process, holes 15 for fitting the pipes 10 and 12 are bored in the cylinder wall surface.

The pipe 10 is made of aluminum (A3003A, etc.), and one end 10a of the pipe is drawn to a length of several mm to match the diameter of the pipe fitting hole 15 provided in the joint member 8.

The corrugated fin 11 for increasing the heat transfer area is
It is made by bending a thin aluminum plate made of material such as A3003 with a thickness of 0.06 to 0.13 into a serpentine shape. This aluminum plate was not subjected to cladding treatment with brazing filler metal on either surface.

As a preliminary step for brazing assembly, each component of the evaporator created as described above is cleaned of dirt and foreign substances such as oil and fat adhering to the surface, which can prevent brazing, using a solvent such as Triclean. After that, first place the side plate 7 on one end surface of a tightening jig for temporarily assembling the evaporator, then attach the joint member 8 and the corrugated fin 11, then the end plate 7, the tank plate 1, the corrugated fin 11, and the tank plate. 2, tank plate 1, corrugated fin 11,
The tank plates 2... are stacked one after another to form the evaporator shown in Figure 1.Finally, the side plate 7 on the other end is applied, and then a tightening force is applied to the tightening jig. to complete the temporary assembly. Thereafter, the evaporator is placed in a brazing furnace in a vacuum, air, or nitrogen atmosphere, and the brazing assembly of the evaporator is completed by a known method.

The evaporator taken out from the brazing furnace is airtightly joined with the refrigerant supply and discharge pipes 10 and 12 to the mounting hole 15 of the joint member 8 by brazing using a torch lamp, etc. The final product is completed by assembling joints 13 and 14. In addition, piping 10
It is also possible to perform the brazing of the pipes 10 and 12 simultaneously in the above-mentioned brazing process by appropriately adjusting the direction in which the pipes 10 and 12 are fixed.

5 to 8 are perspective views respectively showing other examples of the shape of the joint member 8, and the joint member ₈₁ in FIG. The aim is to improve brazing joint strength and mechanical strength. The joint member ₈₂ shown in FIG. 6 has a relatively small rectangular tube shape, and by arranging a plurality of joint members in parallel between the end plate 5 and the side plate 7, it can be made similar to the embodiment shown in FIG. You can get the effect. The coupling members 8 ₃ and 8 ₄ shown in FIGS. 7 and 8 each have an elliptical or semi-elliptical shape.

FIG. 9 is an exploded perspective view of the flat tube A illustrating another embodiment of the structure of the flat tube A, in which the tank plates 1 and 2 in the embodiment shown in FIGS. In place of the stamped-out rib groups 1b and 2b for dividing the refrigerant flow path, which are provided respectively in the refrigerant flow path, a corrugated flow divider plate 18 made of a thin aluminum plate pleated in a direction perpendicular to the flow direction of the refrigerant is used. Both compartments a and b in flat tube A
When the evaporator is brazed and assembled, it is joined to both tank plates 1 and 2, and is used to improve the structural strength of the flat tube and the heat exchange capacity. In the above-mentioned embodiment, each pair of ribs of the stamped-out rib groups 1c and 2c provided on both tank plates 1 and 2, which tend to be located opposite each other, intersect in an X shape and are in point contact. On the other hand, the fact that they are joined by line contact contributes to such improved characteristics.

[Effects of the Invention] The method of manufacturing a heat exchanger according to the present invention has the following effects.

(b) The manufacturing method of fitting parts for installing piping for supplying and discharging heat transfer medium to a heat exchanger has traditionally been a process of cutting long round pipes to size, and partially converting round pipes into square pipes. In contrast, the manufacturing method of the present invention consists of the following steps: deforming the square pipe into shape, making a sealing plug for the open end of the square pipe, and brazing the plug to the open end. The manufacturing process can be extremely simplified since it consists of only the process of cutting a long pipe with a shape to a fixed size and the process of drilling a single hole for installing the pipe.

(b) When brazing the joint member between the end plate and the side plate, the brazing surface (outer surface of the square pipe) formed by transforming a conventional round pipe into a square pipe In contrast, the brazing surface formed by cutting according to the present invention is extremely flat, making it difficult to perform airtight brazing because it is difficult to finish a good flat surface. will be held.

[Brief explanation of the drawing]

FIG. 1 is a front view of an evaporator for an automobile air conditioner manufactured by the manufacturing method of the present invention, FIG. An enlarged vertical sectional view, FIG. 4 is an exploded perspective view explaining the piping installation structure at the right end of FIG. 1,
5 to 8 are perspective views of a joint member showing examples of the shape of a pipe joint member, FIG. 9 is an exploded perspective view of a flat pipe, illustrating another example of the internal structure of the flat pipe, and FIGS. 10 and 11 are a partial vertical cross-sectional view of an evaporator and an exploded perspective view of a piping joint, illustrating a conventional evaporator piping installation method. In the figure, A: flat tube, B: bulge of flat tube,
1, 2...tank plate, 5...end plate, 7...side plate, 8...coupling member, 1
0, 11...Piping, 15...Piping fitting hole.

Claims (1)

[Claims] 1. A large number of flat tubes forming a heat transfer medium flow path are stacked and combined such that the heat transfer medium outlet and inlet of each adjacent flat tube are connected to each other. A method for attaching inlet and outlet piping for a heat transfer medium to a laminated heat exchanger having a structure, the method comprises: an end plate abutting each of both laminated end surfaces of the flat tube laminate; and an end plate disposed on the outside of the end plate. A short cylindrical joint member made of metal, which has an arbitrary cross-sectional shape and has a hole for installing the piping in the cylindrical wall surface, is installed between the installed side plate as an outer wall plate of the heat exchanger. The end plate is sandwiched so as to surround the inlet (outlet) of the heat transfer medium, and is heated to a temperature higher than the melting temperature of the brazing filler metal that has been clad in advance on the surfaces of the end plate and the side plate. A method for manufacturing a heat exchanger, characterized by heating and joining these three components by brazing.