JP3632871B2 - Manufacturing method of header tank - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a header tank mainly used in a stacked heat exchanger in which a plurality of tubes and fins are stacked.
[0002]
[Prior art]
In general, a parallel flow type heat exchanger has an inlet side header tank and an outlet side header tank connected to both end sides of a plurality of flat tubes laminated in parallel with each other via a corrugated fin. The heat exchange medium is passed in parallel or several times tortuously.
[0003]
The flat tubes are joined by integral brazing by inserting tube ends into tube insertion holes provided in a large number of header tanks, and the tube insertion holes have projections (burring) and brazing. A joint surface is provided along the protruding portion.
[0004]
Thus, as what has a projection part in a tube insertion hole, what was described in Unexamined-Japanese-Patent No. 4-62394 is known, and as what has a joint surface along this protrusion part, for example For example, what is described in JP-A-2-16999 is known.
[0005]
In the invention described in Japanese Patent Laid-Open No. 4-62394, a header tank material coated with a brazing material is provided with an inwardly extending guide piece (burring) at an upper and lower opening edge, and an outer edge thereof is inward. A taper portion having a reduced diameter is formed. As described above, 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 circumferential surfaces of the tube to prevent the tube from wobbling, and the tapered portion is tapered with the tube. This facilitates the flow of the brazing material into the gap with the part to form a sufficient fillet to improve the brazing property, prevent liquid leakage, and improve the durability of the heat exchanger.
[0006]
In the invention described in Japanese Patent Laid-Open No. 2-169995, a core metal is put into the header tank material, and the header tank material is pressed from the outside by a press die, so that the thickness of a part of the header tank material is reduced. Then, a taper portion is formed, and then a tube insertion hole is formed in a portion where the thickness is reduced by a hole-forming metal fitting. 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. Thus, no groove is formed in the connection portion between the header tank and the tube, and since a flat portion is formed around the tube insertion hole, the heat exchange medium flows between the header tanks without leaking, Furthermore, the inconvenience that moisture etc. accumulate and a heat exchanger corrodes can be eliminated.
[0007]
[Problems to be solved by the invention]
However, in the tube insertion hole 5 described in JP-A-4-62394, as shown in FIG. 10, a guide piece (burring) 5b is formed in a state where a brazing material is coated on the joining surface 5a. Therefore, the brazing material existing on the joining surface 5a is melted and separated from the joining surface due to heat during brazing, and a large clearance is generated in the tube insertion hole, thus causing a brazing failure and lowering the manufacturing yield. There was a problem of letting.
[0008]
In addition, as described in JP-A-2-16995, when forming a tapered portion by reducing the thickness of a part of the header tank material, it is necessary to apply a mandrel to form a joint surface. In addition, the number of processes increases and the manufacturing process becomes complicated, and manufacturing equipment increases.
[0009]
Therefore, in the present invention, the tube of the header tank that can secure the assembling property of the tube and the header tank and improve the brazing property of the tube and the header tank without generating extra clearance in the tube insertion hole. A method for manufacturing an insertion hole is provided.
[0010]
[Means for Solving the Problems]
The invention described in claim 1 of the present application is a heat exchanger in which a tube insertion hole for inserting a tube is formed at any point in the course of forming a header tank by rolling a header tank material coated with a brazing material. In the method for manufacturing a header tank, the tube insertion hole is formed larger than the dimension of the tube to be inserted, and a jig for holding the tube insertion hole is inserted into the tube insertion hole, and the jig is This is a header tank manufacturing method in which a header tank is formed by rounding a header tank material while being inserted into a tube insertion hole.
[0011]
Thus, since a jig is inserted into the tube insertion hole to form the header tank, when the header tank is formed by deforming the flat plate material, the tube insertion hole formed in the header tank material The header tank can be formed without changing the shape and size. Therefore, since the accuracy of forming 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 rounding a flat plate material without inserting a metal core, it was difficult to maintain the forming accuracy of the tube insertion hole. When the tank is molded, the header tank can be formed with improved molding accuracy of the tube insertion hole as described above.
[0012]
In addition, since the jig provided in the tube insertion hole can be applied to a mold used when the header tank is rolled, a large process such as inserting it separately in the longitudinal direction of the header tank like a conventional cored bar. It can be implemented without the need.
[0013]
The invention described in claim 2 of the present application is the method of manufacturing a header tank according to the invention of claim 1, wherein the tube insertion hole has a joint surface not covered with a brazing material.
[0014]
As described above, since the joining surface formed in the tube insertion hole is not coated with the brazing material, the brazing material existing on the joining surface melts at the time of brazing as in the conventional case, and excess clearance is provided in the tube insertion hole. Is eliminated, tube assemblability is ensured, and the tube and header tank can be securely brazed. That is, since there is no brazing material that melts during brazing on the joint surface of the tube insertion hole, the dimension of the gap formed between the tube insertion hole and the tube can be set with high accuracy.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, specific examples of the present invention will be described in detail with reference to the drawings.
[0016]
FIG. 1 shows a front view of a heat exchanger. In this heat exchanger 1, a plurality of flat tubes 2 and corrugated fins 3 are alternately stacked, and both end sides of these stacked flat tubes 2 are The header tank 4 is connected to the header tank 4 by being inserted into tube insertion holes 5 and 5 (to be described later) provided in the header tank 4. The opening at the upper and lower ends of the header tank 4 is closed by a cap 6, an inlet joint 7 is provided in one header pipe, an outlet joint 8 is provided in the other header pipe, and further required locations inside both header pipes A partition plate 9 is provided to allow the heat exchange medium to meander and flow between the inlet joint 7 and the outlet joint 8 a plurality of times. Further, a side plate 10 having a U-shaped cross section is disposed on the upper end side and the lower end side of the laminated flat tubes 2.
[0017]
Next, a method for forming the tube insertion hole 5 for inserting the tube 2 into the header tank 4 of the heat exchanger will be described with reference to the drawings.
[0018]
2 to 5 show a manufacturing process of the tube insertion hole according to the specific example of the present invention, and are a cross-sectional view of a holding metal fitting and a part of a metal fitting and a header tank material. 2 and 3 are a transverse sectional view and a longitudinal sectional view before drilling, and FIGS. 4 and 5 are a transverse sectional view and a longitudinal sectional view after drilling. FIG. 6 is a cross-sectional view showing the tube insertion hole 5 formed in the header tank material 4A. In this example, the header tank material 4A is coated with a brazing material 11 on the surface.
[0019]
As shown in FIG. 2, the holding mold 12 has a protruding portion 13 protruding in an arc shape for holding the header tank material 4 </ b> A, and a fitting 15, which will be described later, is fitted in the central portion of the protruding portion 13 having the arc shape. A fitting portion 14 is formed. An arc-shaped recess for projecting both ends at an acute angle is formed at the front end of the fitting 15 so that the header tank material 4A can be pushed out.
[0020]
Further, as shown in FIG. 3, a slightly inclined step portion 12 a is provided at the edge portion of the insertion portion 14.
[0021]
The flat header tank material 4 </ b> A is held by the protruding portion 13 of the holding mold 12 after being bent into an arc shape.
[0022]
Next, as shown in FIGS. 4 and 5, the fitting 15 penetrates the header tank material 4 </ b> A held by the holding mold 12 while being inserted into the fitting portion 14. As described above, the header tank material 4A is pushed out while being pressed by the metal fitting 15 without protruding a facet, so that the tube insertion hole 5 provided with the burring portion 5b having the tapered joining surface 5a is formed. . The joint surface 5 a of the tube insertion hole 5 is formed in a state where the brazing material is not covered with the above-mentioned fitting, and the tube insertion hole 5 is slightly between the tube 2 and the tube insertion hole 5 than the tube 2. Formed in large dimensions.
[0023]
The tube insertion hole 5 is formed by being cut off while the header tank material 4A is pressed by the metal fitting 15, so that the joining surface 5a not covered with the brazing material is easily formed, and the fitting portion 14 An inclined surface 5c that is continuous with the joint surface 5a is formed at the opening edge of the tube insertion hole 5 along the step 12a provided at the edge.
[0024]
As described above, since there is no brazing material on the joining surface 5a of the tube insertion hole 5, the brazing material existing on the joining surface melts at the time of brazing as in the conventional case, and extra clearance is generated in the tube insertion hole. As a result, the assembly of the tube is secured, and the tube and the header tank can be securely brazed. That is, since there is no brazing material that melts during brazing on the joint surface of the tube insertion hole, the dimension of the gap formed between the tube insertion hole and the tube can be set with high accuracy.
[0025]
As described above, since the joining surface 5a of the tube insertion hole 5 is formed in a state where it is not covered with the brazing material, no extra clearance is generated on the joining surface 5a. For this reason, the tube 2 can be reliably inserted into the tube insertion hole 5, and the inserted tube 2 is held by the burring portion 5b, and the assembling property is improved. Then, the brazing material that melts at the time of brazing is drawn into the gap formed in the tube 2 and the tube insertion hole 5, and the tube 2 and the header tank 4 are brazed. At this time, since the uneven plane of the tube 2 and the joining surface 5a of the tube insertion hole 5 are brazed with an appropriate gap, the brazing property can be improved.
[0026]
Moreover, the brazing material can be smoothly drawn in the gap formed between the tube 2 and the joint surface 5a of the tube insertion hole 5 by the inclined surface 5c, so that the brazing property is improved. Further, a brazing material that melts during brazing is accumulated on the inclined surface 5c, and brazing can be performed without forming a groove between the header tank 4 and the tube 2.
[0027]
Next, a method of rolling the header tank material 4A in which the tube insertion holes 5 are formed into a circular header tank 4 will be described with reference to the drawings.
[0028]
7 to 9 show a manufacturing process in which the header tank material 4A is rolled to form a circular header tank 4, and a part of two molds and a part of a jig for rounding the header tank material are shown. It is sectional drawing shown.
[0029]
The mold 16 includes 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 includes an arc-shaped recess 20 that engages with the arc-shaped recess 17 of the mold 16.
[0030]
The header tank material 4 </ b> A in which the tube insertion hole 5 is formed is held inside the arc-shaped recess 17 of the mold 16, and a jig 21 for holding the size of the tube insertion hole 5 in the tube insertion hole 5. Is inserted. Then, the end of the header tank material 4 </ b> A is brought into contact with the other mold 19 to form a circular header tank 4.
[0031]
Thus, in order to form the header tank 4 with the jig 21 inserted into the tube insertion hole 5, the tube insertion hole 5 having a good forming accuracy is provided without the size and shape of the tube insertion hole 5 being deformed. The header tank 4 can be molded. Since it is possible to ensure the ease of assembly of the tube 2 and the header tank 4, it is possible to reduce the brazing failure between the tube 2 and the header tank 4 and to improve the production yield.
[0032]
The jig 21 is 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 a mold used when the header tank is rolled, it does not require a large process that is separately inserted in the longitudinal direction of the header tank, unlike a conventional cored bar. Can be implemented. As a result, it is possible to reduce the number of equipment by eliminating the need for a conventional metal core, and it is possible to solve the problem that the manufacturing space is reduced as the number of equipment is increased.
[0033]
Thus, according to this example, the joining surface is formed without covering the tube insertion hole with the brazing material, and the tube insertion hole is located between the tube insertion hole and the tube insertion hole rather than the dimension of the tube to be inserted. Form a slightly larger dimension that creates a gap, and further form a protruding part (burring) or inclined surface in the tube insertion hole with a holding mold and a fitting, etc. Since the header tank can be molded while ensuring molding accuracy, the tube can be securely assembled to the tube insertion hole without generating unnecessary clearance in the tube insertion hole, improving the brazeability. Product yield can be reduced.
[0034]
【The invention's effect】
The invention described in claim 1 of the present application is a heat exchanger in which a tube insertion hole for inserting a tube is formed at any point in the course of forming a header tank by rolling a header tank material coated with a brazing material. In the method for manufacturing a header tank, the tube insertion hole is formed larger than the dimension of the tube to be inserted, and a jig for holding the tube insertion hole is inserted into the tube insertion hole, and the jig is This is a header tank manufacturing method in which a header tank is formed by rounding a header tank material while being inserted into a tube insertion hole.
[0035]
Therefore, since a jig is inserted into the tube insertion hole to form a header tank, when the header tank is formed by deforming a flat plate material, the shape of the tube insertion hole formed in the header tank material The header tank can be formed without changing the size. Therefore, since the accuracy of forming 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 rounding a flat plate material without inserting a metal core, it was difficult to maintain the forming accuracy of the tube insertion hole. When the tank is molded, the header tank can be formed with improved molding accuracy of the tube insertion hole as described above.
[0036]
The invention described in claim 2 of the present application is the method of manufacturing a header tank according to the invention of claim 1, wherein the tube insertion hole has a joint surface not covered with a brazing material.
[0037]
Therefore, since the joining surface formed in the tube insertion hole is not coated with the brazing material, the brazing material existing on the joining surface melts during brazing as in the conventional case, and extra clearance is generated in the tube insertion hole. As a result, the assembly of the tube is ensured, and the tube and the header tank can be securely brazed. That is, since there is no brazing material that melts during brazing on the joint surface of the tube insertion hole, the dimension of the gap formed between the tube insertion hole and the tube can be set with high accuracy.
[0038]
As described above, according to the present invention, the tube insertion hole can be manufactured with improved molding accuracy. Therefore, the assembling property of the tube is ensured, and the brazing property between the tube and the header tank is improved. As a result, it is possible to provide a heat exchanger with a good yield rate.
[Brief description of the 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 process of forming a tube insertion hole in a header tank material according to a specific example of the present invention.
FIG. 3 is a schematic longitudinal sectional view showing a part of a process of forming a tube insertion hole in a header tank material according to a specific example of the present invention.
FIG. 4 is a schematic cross-sectional view showing a part of a process of forming a tube insertion hole in a header tank material according to a specific example of the present invention.
FIG. 5 is a schematic longitudinal sectional view showing a part of a process 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 a process of forming a header tank according to a specific example of the present invention.
FIG. 8 is a schematic cross-sectional view showing a part of a process of forming a header tank according to a specific example of the present invention.
FIG. 9 is a schematic cross-sectional view showing a part of a process of forming a header tank according to a specific example 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]
DESCRIPTION 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 part 5c Inclined surface 6 Cap 7 Inlet joint 8 Outlet joint 9 Partition plate 10 Side plate 11 Brazing material 12 Holding mold 12a Step part 13 Projection part 14 Insertion part 15 Butting metal fitting 16 Mold 17 Recess 18 Insertion groove 19 Mold 20 Recess 21 Jig

Claims (2)

In a method of manufacturing a header tank in a heat exchanger in which a tube insertion hole for inserting a tube is formed at any time in the course of forming a header tank by rounding a header tank material coated with a brazing material,
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, and the jig is inserted into the tube insertion hole. A method of manufacturing a header tank, wherein the header tank material is rolled 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 that is not covered with a brazing material.

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