JPH09303988A - Manufacture of header tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure assembly ability of a tube without providing a clearance for a tube insertion hole and to improve brazing ability between a tube and a header tank. SOLUTION: In manufacture of a header tank in a heatexchanger wherein a tube insertion hole 5 to insert a tube is formed at some point of time in the middle of formation of a header tank material 4A covered with a brazing material made round to form a header tank 4, the tube insertion hole 5 is formed in size larger than the size of the inserting tube. A jig 21 to hold the tube insertion hole is inserted in the tube insertion hole 5 and the header tank element 4A is made round with the jig 21 inserted in the tube insertion hole 5 to form the header tank 4. Further, the tube insertion hole 5 has a joint not covered with a brazing material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a header tank mainly used in a laminated heat exchanger in which a plurality of tubes and fins are laminated.

[0002]

2. Description of the Related Art Generally, a parallel flow type heat exchanger has a plurality of flat tubes which are stacked in parallel with each other via wavy fins. The heat exchange medium is passed between the header tanks in parallel or meandering several times.

The flat tubes are joined by integral brazing by inserting the tube ends into a large number of tube insertion holes provided in the header tank, and the tube insertion holes are provided with protrusions (for brazing). Burring) and a joint surface along the protruding portion are provided.

[0004] As described above, as the one having the projecting portion in the tube insertion hole, for example, the one described in Japanese Patent Application Laid-Open No. 4-62394 is known, and it has a joint surface along the projecting portion. For example, Japanese Patent Laid-Open No. Hei 2
The one described in Japanese Patent Publication No. 169995 is known.

In the invention described in the above-mentioned JP-A-4-62394, a header tank material coated with a brazing material is provided with guide pieces (burrings) extending inward at the upper and lower opening edges, and the outer edges thereof are A tapered portion is formed so as to decrease in diameter toward the inside. In this way, since the guide piece and the tapered portion are formed at the upper and lower opening edges of the tube insertion hole, the guide piece supports the upper and lower peripheral surfaces of the tube to prevent the tube from wobbling, and the tapered portion forms a taper with the tube. The brazing filler metal is easily flowed into the gap between the parts to form a sufficient fillet to improve the brazing property, prevent liquid leakage, and improve the durability of the heat exchanger.

Further, in the invention described in the above-mentioned JP-A-2-169995, a core metal is put in a header tank material, and the header tank material is pressed from the outside by a press die to form a part of the header tank material. Is thinned to form a taper portion, and then a tube insertion hole is formed in the portion where the wall thickness is thinned by the metal fitting for punching. If formed in this way, the tube insertion hole has a tapered portion, and a flat portion is formed around the tapered portion. When the taper portion and the tube are brazed, the groove between the taper portion and the tube is completely closed by the brazing material. In this way, since no groove is formed in the connecting portion between the header tank and the tube and a flat portion is formed around the tube insertion hole, the heat exchange medium flows between the header tanks without leaking, Further, it is possible to eliminate the inconvenience that water or the like is accumulated and the heat exchanger is corroded.

[0007]

However, the tube insertion hole 5 described in Japanese Patent Laid-Open No. 4-62394 is disclosed.
As shown in FIG. 10, since the guide piece (burring) 5b is formed in a state where the brazing material is coated on the joint surface 5a, it will be present on the joint surface 5a due to heat during brazing. There is a problem that the material melts and separates from the joint surface, and a large clearance is generated in the tube insertion hole, which causes brazing failure and reduces the manufacturing yield.

Further, as described in JP-A-2-16995, when a part of the header tank material is thinned to form a taper portion, a core metal is applied to form a joint surface. It is necessary to increase the number of steps, complicate the manufacturing process, and increase the number of manufacturing equipment.

Therefore, in the present invention, the header which can secure the assembling property of the tube and the header tank and can improve the brazing property of the tube and the header tank without generating an extra clearance in the tube insertion hole. A method for manufacturing a tube insertion hole of a tank is provided.

[0010]

SUMMARY OF THE INVENTION The invention described in claim 1 of the present application is a tube for inserting a tube at any point in the process of rolling a header tank material coated with a brazing material to form a header tank. In the method of manufacturing a header tank in a heat exchanger in which an insertion hole is formed, the tube insertion hole is formed to be larger than the size of the tube to be inserted, and a jig for holding the tube insertion hole in the tube insertion hole. Is inserted, and the header tank material is rolled while the jig is inserted into the tube insertion hole to form a header tank.

As described above, the jig is inserted into the tube insertion hole to form the header tank. Therefore, when the header tank is molded by deforming the flat plate-shaped material, the tube formed in the header tank material. The header tank can be molded without changing the shape or size of the insertion hole. Therefore, since the molding accuracy of the tube insertion hole is improved, the assembling property of the tube is improved, and good brazing is possible. In particular, when forming a header tank by rolling a flat material without inserting a core metal, it was difficult to maintain the molding accuracy of the tube insertion hole. When the tank is molded, the header tank can be formed by improving the molding accuracy of the tube insertion hole as described above.

Since the jig provided in the tube insertion hole can be applied to the mold used for rolling the header tank, it is a large-scale tool to be inserted separately in the longitudinal direction of the header tank like a conventional core metal. It can be carried out without requiring various steps.

A second aspect of the present invention is the method of manufacturing a header tank according to the first aspect of the invention, wherein the tube insertion hole has a joint surface which is not covered with a brazing material.

As described above, since the brazing material is not coated on the joint surface formed in the tube insertion hole, the brazing material existing on the joint surface at the time of brazing is melted as in the conventional case, and the brazing material is melted in the tube insertion hole. No extra clearance is generated, the tube can be assembled easily, and the tube and header tank can be reliably brazed. That is, since there is no brazing material that melts during brazing on the joint surface of the tube insertion hole, the size of the gap formed between the tube insertion hole and the tube can be set accurately.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific examples of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a front view of a heat exchanger. In this heat exchanger 1, a plurality of flat tubes 2 and wavy fins 3 are alternately laminated, and these flat tubes 2 are laminated. Both ends are connected to the header tank 4 by being inserted into tube insertion holes 5 and 5 described later, which are provided in the header tank 4. The openings at the upper and lower ends of the header tank 4 are closed by a cap 6, an inlet joint 7 is provided on one header pipe, an outlet joint 8 is provided on the other header pipe, and further, required locations inside both header pipes. Is provided with a partition plate 9 to allow the heat exchange medium to meander a plurality of times between the inlet joint 7 and the outlet joint 8. Further, side plates 10 having a U-shaped cross section are disposed on the upper end side and the lower end side of the laminated flat tubes 2.

Next, a method for forming the tube insertion hole 5 for inserting the tube 2 in the header tank 4 of the heat exchanger will be described with reference to the drawings.

2 to 5 are sectional views of the tube insertion hole manufacturing process according to the embodiment of the present invention, showing a part of the holding metal fittings and the thrust metal fittings, and the header tank material.
2 and 3 are a horizontal sectional view and a vertical sectional view before drilling, and FIG.
5 and 6 are a horizontal cross-sectional view and a vertical cross-sectional view after drilling. Also,
FIG. 6 is a sectional view showing the tube insertion hole 5 formed in the header tank material 4A. In this example, the header tank material 4A has a surface coated with a brazing material 11.

As shown in FIG. 2, the holding die 12 has an arc-shaped protruding portion 13 for holding the header tank material 4A, and a metal fitting to be described later at the center of the arc-shaped protruding portion 13. A fitting portion 14 into which 15 is fitted is formed. The tip of the metal fitting 15 is formed with an arcuate recess for sharply protruding both ends so that the header tank material 4A can be opened.

Further, as shown in FIG. 3, a slightly inclined step portion 12a is provided at the edge of the fitting portion 14.

The flat header tank material 4A is bent in an arc shape and then held by the protruding portion 13 of the holding die 12.

Next, as shown in FIGS. 4 and 5, the metal fitting 15 is pressed through the header tank material 4A held by the holding mold 12 and is inserted into the fitting portion 14 while penetrating.
In this way, the header tank material 4A is pushed out by the pushing metal fitting 15 without being cut out, and the tube insertion hole 5 provided with the burring portion 5b having the tapered joint surface 5a is formed. . The joint surface 5a of the tube insertion hole 5 is formed in a state where the brazing material is not covered by the above-mentioned metal fitting, and the tube insertion hole 5
Is formed between the tube 2 and the tube insertion hole 5 in a size slightly larger than the tube 2.

The tube insertion hole 5 is formed by pushing the header tank material 4A while pressing the header tank material 4A by the pushing metal fitting 15, so that the joining surface 5 not covered with the brazing filler metal 5 is formed.
a is easily formed, and an inclined surface 5c continuous with the joint surface 5a is formed at the opening edge portion of the tube insertion hole 5 along the step portion 12a provided at the edge portion of the fitting portion 14.

Thus, the joint surface 5 of the tube insertion hole 5
Since there is no brazing filler metal in a, the brazing filler metal present on the joint surface at the time of brazing does not melt and no extra clearance is generated in the tube insertion hole unlike in the conventional case, so that the tube assembling property is secured. As a result, reliable brazing of the tube and header tank is possible. That is, since there is no brazing material that melts during brazing on the joint surface of the tube insertion hole, the size of the gap formed between the tube insertion hole and the tube can be set accurately.

As described above, since the joint surface 5a of the tube insertion hole 5 is formed without being covered with the brazing material, no extra clearance is generated on the joint surface 5a. Therefore, the tube 2 can be reliably inserted into the tube insertion hole 5, and the inserted tube 2
Are held by the burring portion 5b to improve the assembling property. Then, the brazing material that melts during brazing is drawn into the gap formed between the tube 2 and the tube insertion hole 5, and the tube 2 and the header tank 4 are brazed. At this time, the flat surface of the tube 2 and the joint surface 5 of the tube insertion hole 5
Since a is brazed with an appropriate gap, the brazability can be improved.

Further, since the inclined surface 5c allows the brazing material to be melted to be smoothly drawn into the gap formed between the tube 2 and the joint surface 5a of the tube insertion hole 5, the brazing property is improved. Further, the brazing filler metal that melts during brazing is collected on the inclined surface 5c, and the header tank 4
It is possible to braze without forming a groove between the tube 2 and the tube 2.

Next, a method of rolling the header tank material 4A in which the tube insertion hole 5 is formed to form the circular header tank 4 will be described with reference to the drawings.

7 to 9 show the header tank material 4A.
FIG. 6 is a cross-sectional view showing a manufacturing process for forming a round header into a circular header tank 4 and showing a part of two molds for rounding the header tank material and a part of a jig.

The mold 16 is provided with an arc-shaped recess 17 and an insertion groove 18 into which a jig 21 described later is inserted in the center of the arc-shaped recess 17. The other mold 19 has an arcuate recess 20 that engages with the arcuate recess 17 of the mold 16.
It has.

The header tank material 4A in which the tube insertion hole 5 is formed is held inside the arc-shaped recess 17 of the die 16, and the tube insertion hole 5 is inserted into the tube insertion hole 5.
The jig 21 for holding the size of is inserted. Then, by the other mold 19, the header tank material 4
The end portions of A are brought into contact with each other to form the cylindrical header tank 4.

In this way, the jig 21 is inserted into the tube insertion hole 5.
Since the header tank 4 is formed with the tube inserted thereinto, the size and shape of the tube insertion hole 5 are not deformed, and the header tank 4 provided with the tube insertion hole 5 with high molding accuracy can be molded. Since it is possible to ensure the assemblability of the tube 2 and the header tank 4, it is possible to reduce defective brazing of the tube 2 and the header tank 4 and to improve the manufacturing yield.

The jigs 21 are provided in the mold 16 according to the number of tube insertion holes 5 formed in the header tank material 4A. Therefore, since the jig 21 can be applied to the mold used for rolling the header tank, it does not require a large-scale process such as a separate insertion in the longitudinal direction of the header tank unlike the conventional cored bar. It can be carried out. As a result, it is possible to reduce the number of fixtures by eliminating the need for a conventional cored bar, and to solve the problem that the manufacturing space is narrowed as the number of fixtures increases.

As described above, according to this example, the joint surface is formed in a state where the brazing material is not covered in the tube insertion hole, and the tube insertion hole has a tube-to-tube insertion hole rather than a dimension of the tube to be inserted. A slightly larger size that creates a gap between the two is formed, and a holding die and a metal fitting are used to form a protruding part (burring) or an inclined surface in the tube insertion hole. Since the header tank can be molded with the molding accuracy of the insertion hole secured, the tube can be reliably assembled into the tube insertion hole without creating unnecessary clearance in the tube insertion hole, and the brazability is improved. It is possible to improve and reduce the yield of products.

[0034]

According to the first aspect of the present invention, a tube insertion hole for inserting a tube is formed at any point in the process of rolling a header tank material coated with a brazing material to form a header tank. In the method for manufacturing a header tank in a heat exchanger, the tube insertion hole is formed larger than the size of the tube to be inserted, and a jig for holding the tube insertion hole is inserted into the tube insertion hole, In the header tank manufacturing method, the header tank material is rolled to form the header tank while the jig is inserted into the tube insertion hole.

Therefore, since the jig is inserted into the tube insertion hole to form the header tank, the tube insertion hole formed in the header tank material is formed when the flat plate material is deformed to form the header tank. The header tank can be molded without changing the shape or size of the.
Therefore, since the molding accuracy of the tube insertion hole is improved, the assembling property of the tube is improved, and good brazing is possible. In particular, when forming a header tank by rolling a flat material without inserting a core metal, it was difficult to maintain the molding accuracy of the tube insertion hole. When the tank is molded, the header tank can be formed by improving the molding accuracy of the tube insertion hole as described above.

A second aspect of the present invention is the method of manufacturing a header tank according to the first aspect of the invention, wherein the tube insertion hole has a joint surface not covered with a brazing material.

Therefore, since the joining surface formed in the tube insertion hole is not covered with the brazing material, the brazing material present on the joining surface at the time of brazing is melted as in the conventional case, and an excessive amount is left in the tube insertion hole. Clearance is not generated, tube assembly is ensured, and tubes and header tanks can be brazed reliably. That is,
Since there is no brazing material that melts at the time of brazing on the joint surface of the tube insertion hole, the size of the gap formed between the tube insertion hole and the tube can be set accurately.

As described above, according to the present invention, it is possible to manufacture the tube insertion hole while improving the molding accuracy, so that the assembling property of the tube is secured and the brazing property of the tube and the header tank is improved. To do. As a result, it is possible to provide a heat exchanger having a good yield rate.

[Brief description of drawings]

FIG. 1 is a front view of a heat exchanger according to a specific example of the present invention.

FIG. 2 is a schematic cross-sectional view showing a part of a step of forming a tube insertion hole in a header tank material according to the embodiment of the present invention.

FIG. 3 is a schematic vertical sectional view showing a part of a step of forming a tube insertion hole in a header tank material according to the embodiment of the present invention.

FIG. 4 is a schematic cross-sectional view showing a part of a step of forming a tube insertion hole in a header tank material according to the embodiment of the present invention.

FIG. 5 is a schematic vertical sectional view showing a part of a step of forming a tube insertion hole in a header tank material according to a specific example of the present invention.

FIG. 6 is a cross-sectional view showing a tube insertion hole formed in a header tank material according to a specific example of the present invention.

FIG. 7 is a schematic cross-sectional view showing a part of the process of forming the header tank according to the embodiment of the present invention.

FIG. 8 is a schematic cross-sectional view showing a part of the process of forming the header tank according to the embodiment of the present invention.

FIG. 9 is a schematic cross-sectional view showing a part of the process of forming the header tank according to the embodiment of the present invention.

FIG. 10 is a cross-sectional view showing a tube insertion hole formed in a header tank material according to a conventional example.

[Explanation of symbols]

 1 heat exchanger 2 tube 3 fin 4 header tank 4A header tank material 5 tube insertion hole 5a joint surface 5b burring portion 5c inclined surface 6 cap 7 inlet joint 8 outlet joint 9 partition plate 10 side plate 11 brazing filler metal 12 holding mold 12a Step portion 13 Projection portion 14 Fitting portion 15 Pushing metal fitting 16 Mold 17 Recessed portion 18 Insertion groove 19 Mold 20 Recessed portion 21 Jig

Claims (2)

[Claims] 1. Manufacturing of a header tank in a heat exchanger in which a tube insertion hole for inserting a tube is formed at any point on the way to form the header tank by rolling the header tank material coated with the brazing material. In the method, the tube insertion hole is formed to be larger than the size of the tube to be inserted, a jig for holding the tube insertion hole is inserted into the tube insertion hole, and the jig is inserted into the tube insertion hole. A method of manufacturing a header tank, wherein the header tank material is rolled as it is to form a header tank. 2. The method of manufacturing a header tank according to claim 1, wherein the tube insertion hole has a joint surface which is not covered with a brazing material.