JPH1183380A - Header tank for heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provided a header tank for a heat exchanger in which a connecting area at a burring formed at an inner circumference of a tube insertion hole is expanded, a brazing characteristic is assured, and a brazing strength is improved. SOLUTION: A header tank of a heat exchanger into which end portions of a plurality of tubes arranged in parallel from each other are inserted is constructed such that a burring 12 formed at a tube insertion hole of the header tank is formed by a hole forming jig 16 for forming the burring 12, and a die 17 having an insertion hole 18 formed to have a narrower width than that in which both a width of an inserting section of the hole forming jig 16 and a width twice of a wall thickness of the header tank raw material are added from each other. A surplus wall thickness α of the header tank raw material at the part where it is made narrower than the insertion hole 18 is pushed wide to form the burring 12 and then the connected area between it and the tube is expanded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger in which the ends of a plurality of tubes are connected to a tube insertion hole of a header tank and brazed. It relates to the header tank of the exchanger.

[0002]

2. Description of the Related Art In general, in a laminated heat exchanger, a plurality of flat tubes and wavy fins are alternately laminated, and both ends of the laminated tubes are inserted into insertion holes provided in left and right tanks. Or a tank is connected to one end of a laminated tube (single tank type). Further, at a required portion of the tank of the parallel flow type heat exchanger, a partition plate for partitioning the tank in the longitudinal direction is provided, the tank is divided in the longitudinal direction, and an inlet joint and an outlet joint provided on the tank are provided. Is provided in a structure in which the heat exchange medium is meandered a plurality of times and flows therethrough.

[0003] The flat tubes are joined by brazing by inserting the ends of the tubes into tube insertion holes provided in a large number of header tanks and integrally brazing the tube insertion holes. Burring is provided.

[0004] Japanese Patent Application Laid-Open No. 61-10843 discloses a tube insertion hole having a burring.
Japanese Unexamined Patent Publication No. 5 and JP-A-2-176397 are known.

For example, in the invention described in Japanese Patent Application Laid-Open No. 61-108435, after a hole smaller than the cross section of the tube is formed in the header tank, a burring process is performed around the hole to reduce the size of the hole. Is larger than the cross section of the tube and forms an upwardly projecting flange around the hole. This flange is connected to the header plate via a rounded portion, the end of the tube is inserted into the hole, and the rounded portion is beaten from outside by a press, so that the inner peripheral surface of the flange is formed on the outer peripheral surface of the tube. A structure is provided in which the header plate and the tube are temporarily fixed to each other to be in close contact with each other.

In the invention described in Japanese Patent Application Laid-Open No. 2-176397, in a header tank composed of a header pipe and a header cover, an opening is formed in the header pipe by cutting out one portion in a circumferential direction at a constant width. Then, a jig for performing burring processing on the header pipe is inserted from the opening to form an elongated hole formed with burring on the side wall of the header pipe.

[0007]

However, in the case of the invention described in the above-mentioned Japanese Patent Application Laid-Open No. 61-108435, a rounded portion is formed when burring is formed.
After the tube is inserted into the insertion hole, the R-shaped portion is crushed to bring the flat surface of the tube into close contact. In this way, a rounded portion is formed, and further the flattened portion is crushed,
The work of bringing the flat surface of the tube into close contact with this is very difficult in practice.

As shown in FIG. 6, when a burring is formed in a header tank which is formed by rolling a flat header tank material into a circular tube shape, a conventional method is used to form a flat or somewhat rounded header tank. Header tank material
It is installed in a mold in which an insertion hole for forming a tube insertion hole is formed, and a hole forming jig is protruded toward the insertion hole of the mold, and the hole forming jig extends along the width of the insertion hole of the mold. In this method, a burring is formed on the inner periphery of the tube insertion hole by pressing the header tank material.

In this case, the width of the insertion hole of the mold is determined in consideration of the thickness of the header tank material and the width of the insertion portion of the hole forming jig.
The width obtained by adding the thickness of the header tank material twice and the width of the insertion portion of the hole forming jig was defined as the width of the insertion hole. Therefore, the header tank material is pressed by only one half of the width of the insertion portion of the hole forming jig, the burring formed on the inner periphery of the tube insertion hole is small, and is joined to the uneven plane of the tube. Since the joint area of the burring is small, there has been a problem that the brazing property cannot be secured.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a header tank for a heat exchanger capable of increasing the joining area of burring, securing brazing properties, and improving brazing strength.

[0011]

According to the present invention, at least one end of a plurality of tubes arranged in parallel with each other is inserted into a tube insertion hole formed with burring of a header tank, and is integrally brazed to the header tank. The burring formed in the tube insertion hole of the header tank is formed by placing the header tank material on a mold having an insertion hole for forming a burring, and forming a straight blade portion. Is formed by penetrating the header tank material above the insertion hole with a hole forming jig formed therein, and the insertion hole of the mold is formed with the width of the insertion portion of the hole forming jig and the tube. This is a header tank of the heat exchanger having a configuration formed to have a width smaller than a width obtained by adding both widths twice as large as the plate thickness.

As described above, the width of the insertion hole of the mold is formed to be smaller than the width obtained by adding both the thickness of the header tank material twice and the width of the insertion portion of the hole forming jig. For,
A tube insertion hole is formed in the header tank material by the blade portion of the hole forming jig, and further, the hole forming jig is protruded through the insertion hole of the mold to form burring on the inner periphery of the tube insertion hole. The extra thickness of the header tank material, which is the difference between the width of the insertion portion of the hole forming jig and the width obtained by adding twice the thickness of the header tank material minus the width of the insertion hole,
Burring is formed while pressing and extending.
Therefore, the area of the formed burring increases, and the joining area between the tube and the uneven plane increases, so that the brazing property of the tube and the tube insertion hole is ensured, and the header tank and the tube of the heat exchanger are brazed. Strength can be improved.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

Referring to FIG. 1, a heat exchanger 1 according to the present embodiment comprises:
A plurality of flat tubes 2 are stacked in parallel with each other via wavy fins 3, and both ends of these flat tubes 2 are inserted into tube insertion holes 7 provided in a header tank 4,
It is integrally joined to each header tank 4 by brazing. In FIG. 1, reference numeral 8 denotes an inlet joint, and 9 denotes an outlet joint.

As shown in FIGS. 2 and 6, the header tanks 4 are made of a brazing sheet of a predetermined shape having clad material coated on both sides thereof, as shown in FIGS.
The header tank material 4A is rolled up and both ends are joined to end portions 4B and 4B.
B is formed in a cylindrical shape. As shown in FIGS. 3 and 4, tube insertion holes 7 are provided in the header tank material 4 </ b> A corresponding to the arrangement intervals of the flat tubes 2. The upper and lower openings of the header tank 4 are closed by blind caps 10 as shown in FIG.

Next, a method of forming the tube insertion hole 7 and the burring 12 will be described.

The burring 12 of this embodiment is shown in FIG.
As shown in (b), the tube insertion hole 7 is formed simultaneously with the mold 17 and the hole forming jig 16 when the tube insertion hole 7 is formed in the header tank material 4A. That is, by pressing a hole forming jig 16 formed in a plate shape having a predetermined thickness and a predetermined width and having a linear blade portion 15 at a tip portion into an insertion hole 18 of a mold 17, cutting is performed from the beginning of pressing. Blade 15 of hole forming jig 16 in header tank material 4A
Is formed, and then the header tank material 4A is cut along the recess 19 to form the tube insertion hole 7 and the burring 12 at the same time. The joining surface 12a of the burring 12 is formed in a plane parallel to the flat surface of the flat tube 2 so as to be along the flat surface of the flat tube 2.

The width Y of the insertion hole 18 of the mold 17, the thickness X of the hole forming jig 16, and the thickness Z of the header tank material 4 A have the following relationship.

The width Y of the insertion hole 18 of the mold 17 is formed to be equal to or larger than the thickness X of the hole forming jig 16 and the thickness Z of the header tank material 4A is taken into consideration. The width is smaller than the width obtained by adding the plate thickness Z twice as large as 4A and the plate thickness X of the hole forming jig 16.

The width Y of the insertion hole 18 and the hole forming jig 16
And the thickness Z of the header tank material 4A can be expressed by the following equation.

X <Y <X + 2Z Conventionally, as shown in FIGS. 7A and 7B, the width Y of the insertion hole 18 is twice the plate thickness Z of the header tank material 4A and the hole forming jig. The width was formed to be the same as the width obtained by adding the 16 sheet thicknesses X.

Y = X + 2Z Therefore, the header tank material 4A has a width of 1 obtained by subtracting the left and right plate thicknesses Z of the header tank material 4A from the width Y of the insertion hole 18.
Burring was formed by being pressed only for the length of / 2.

(Y-2Z) / 2 = X / 2 That is, in the related art, the burring 12 is formed so that the header tank material 4A is pressed only for approximately the length of X / 2 and protrudes in the direction of the insertion hole 18. Was. For this reason, the length of the protruding burring is only about X / 2, and the area of the burring is small.
The contact area of the joint surface 12a of the burring 12 was reduced, so that the brazing property was not secured and the brazing strength could not be improved.

However, according to the present embodiment, as described above, the width Y of the insertion hole 18 of the mold 17 has a relationship represented by the following equation.

Y-2Z <X Therefore, as shown in FIG. 5 (b), the header tank material 4A has an arbitrary α in the plate thickness Z of the header tank material 4A as compared with the width Y of the insertion hole 18. The extra thickness is required.

Y = X + 2Z−2α (Y <X + 2Z) (α: arbitrary width and thickness) For this reason, the header tank material 4A has a width Y of the insertion hole 18.
The length corresponding to 幅 of the width obtained by subtracting the left and right plate thicknesses Z of the header tank material 4A and the extra thickness α are pressed to form burring.

[0027] Therefore, in this example, the burring 12 protruding in the direction of the insertion hole 18 is formed while the hole forming jig 16 pushes and widens the extra thickness α. That is, the extra thickness α
Extend the header tank material 4A by the amount of burring 12
Is formed, the joining surface 12a of the burring 12 is enlarged by an extra thickness α.

Thereafter, the header tank material 4A is transferred to a rounding step, and both ends of the header tank material 4A are slightly shifted from the flat header tank material 4A shown in FIG. 6A as shown in FIG. 6B. After being bent, as shown in FIGS. 6c and 6d, the header tank material 4A is sequentially bent so as to gradually become round, and finally, as shown in FIG. 7e, the joining ends 4B, 4B come into contact with each other. The header tank 4 is formed by being rounded so as to be round.

Then, the tube 2 is inserted into the tube insertion hole 7, and the uneven surface of the tube 2 is brought into contact with the joining surface 12a of the burring 12, so that the tube 2 is
The brazing material clad on the surface and the surface of the header tank is melted and brazed integrally.

As described above, the header tank of the heat exchanger according to the present embodiment has an optional extra thickness α on the inner peripheral surface of the tube insertion hole 7.
Since the burring 12 having the enlarged joint area 12a is formed by the same amount, the contact area for joining with the uneven plane of the tube 2 is increased, and the brazing property of the tube 2 and the tube insertion hole 7 can be secured. Brazing strength can be improved.

Further, since the burring 12 is formed by expanding the area while the excess thickness α is pressed, it is possible to obtain a desired burring length by appropriately setting the thickness α. Can be.

In the above-described example, the header tank is made of a brazing sheet of a predetermined shape having clad material coated on both sides as a header tank material, and the header tank material is rolled and joined at both ends to form a circle. Although the description has been given taking the example of a tubular shape, the present invention is also applicable to the case of a two-piece header pipe.

[0033]

As described above, according to the present invention, at least one end of a plurality of tubes arranged in parallel with each other is inserted into a tube insertion hole formed with burring of a header tank, and is integrated with the header tank. In the heat exchanger joined by brazing, the burring formed in the tube insertion hole of the header tank is formed by placing the header tank material on a mold having a burring formation insertion hole, and forming a straight line. A hole forming jig in which a blade portion is formed is formed so as to penetrate the header tank material on the insertion hole, and the insertion hole of the mold has a width corresponding to a width of an insertion portion of the hole forming jig. This is a header tank of the heat exchanger having a configuration formed to have a width smaller than a width obtained by adding both widths of the tube thickness twice.

As described above, the width of the insertion hole of the mold is formed to be narrower than the width obtained by adding both the thickness of the header tank material twice and the width of the insertion portion of the hole forming jig. For,
A tube insertion hole is formed in the header tank material by the blade portion of the hole forming jig, and further, the hole forming jig is protruded through the insertion hole of the mold to form burring on the inner periphery of the tube insertion hole. The extra thickness of the header tank material, which is the difference between the width of the insertion portion of the hole forming jig and the width obtained by adding twice the thickness of the header tank material minus the width of the insertion hole,
Burring is formed while pressing and extending.
Therefore, the area of the formed burring increases, and the joining area between the tube and the uneven plane increases, so that the brazing property of the tube and the tube insertion hole is ensured, and the header tank and the tube of the heat exchanger are brazed. The strength can be improved.

[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 cross-sectional view showing a header tank.

FIG. 3 is a front view showing a header tank.

FIG. 4 is a side view showing a header tank.

FIG. 5 (a) and (b) relate to a specific example of the present invention.
It is a longitudinal cross-sectional view which shows the formation state of a hole formation jig and a tube insertion hole.

FIGS. 6A to 6E are schematic end views showing header tank materials that are sequentially rounded.

FIGS. 7A and 7B are longitudinal sectional views showing a state in which a hole forming jig and a tube insertion hole are formed according to a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heat exchanger 2 Flat tube 3 Wavy fin 4 Header tank 4A Header tank material (brazing sheet) 4B Header tank material end 7 Tube insertion hole 8 Inlet joint 9 Outlet joint 10 Cap 12 Burring 12a Joining surface 15 Blade portion 16 Hole formation Jig 17 Mold 18 Insertion hole 19 Depression X Thickness of hole forming jig Y Width of insertion hole Z Thickness of tank plate α Extra thickness

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Sadao Haiya 39, Higashihara, Chiyo-ji, Odai-gun, Osato-gun, Saitama Prefecture Inside of Xexel Konan Plant (72) Inventor Takashi Sugita Higashihara, Oji-gun, Onan-gun, Saitama No. 39 Inside the Xexel Gangnam Plant (72) Inventor Katsuji Akiyama Higashihara, Chiyo-ji, Odai-gun, Osato-gun, Saitama 39 Inventor Takafumi Umehara Takahara Uenohara, Chiyo-ji, Chiyo-ji, Konan-cho, Osato-gun, Saitama No. 39 Inside Zexel Gangnam Plant

Claims (1)

[Claims] 1. A heat exchanger in which at least one end of a plurality of tubes arranged in parallel with each other is inserted into a tube insertion hole formed with burring of a header tank and is joined to the header tank by integral brazing. A burring formed in the tube insertion hole of the header tank is a hole forming jig in which a header tank material is placed on a mold having an insertion hole for forming a burring, and a straight blade portion is formed. The through hole of the mold is formed so as to penetrate the header tank material on the insertion hole, and the width of the insertion portion of the mold and the width of twice the plate thickness of the tube. A header tank for a heat exchanger, wherein the header tank is formed to have a width smaller than a width obtained by adding both.