JP3316082B2 - Heat exchanger header tank - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a header tank for a laminated heat exchanger in which the brazing of a tube insertion hole is improved when brazing a header tank to a flat tube.

[0002]

2. Description of the Related Art In general, in a laminated heat exchanger, inlet and outlet header tanks are connected to both ends of a plurality of flat tubes laminated in parallel via corrugated fins (both tank types). A stacked heat exchanger is known in which a header tank is connected to one end of a flat tube (single tank type), and a heat exchange medium is meandered a plurality of times between inlet and outlet joints provided in the header tank. Have been.

[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 a burring is formed in the tube insertion holes for brazing. Is provided.

[0004] Japanese Patent Application Laid-Open No. 61-23569 discloses a tube having a burring in the tube insertion hole.
No. 8 is known.

In the header tank described in the above publication,
As shown in FIG. 11, a burring 23 projecting into the header tank 21 is formed in each tube insertion hole 22 provided in the header tank 21.
Facilitates insertion of the flat tube 24,
The burring 23 has a structure capable of joining with a larger area.

[0006] Also, in a header tank composed of a tank plate and an end plate, when the tube insertion hole is formed in the end plate at the time of press molding, it is formed in a bulging shape projecting outward between the tube insertion holes. At the same time, a burring is formed on the inner periphery of the tube insertion hole, and the burring has a structure that can be joined with a large area.

Further, the burring is formed so as to be parallel to each other so as to be uniformly in contact from the insertion inlet to the back, and to be parallel to the tube inserted into the tube insertion hole.

[0008]

However, in the conventional header tank, the burring of the tube insertion hole is parallel to each other so that the burring is uniformly contacted from the entrance of the insertion hole to the end at the back. Since it was formed so as to be parallel to the surface of the tube to be inserted, there was no place where a brazing pool part was formed in which the brazing material melted during brazing was formed. The brazing material flowed out from between the burring of the tube insertion hole and the flat tube, and the brazing failure between the flat tube and the tube insertion hole is likely to occur,
There is a problem that air leaks are likely to occur and the yield of heat exchanger production is reduced.

Accordingly, the present invention provides a header tank for a heat exchanger in which the brazing property between a tube insertion hole and a tube is enhanced, brazing properties and airtightness are improved, and the yield of heat exchanger production is improved. It is intended to be.

[0010]

In the header tank of the heat exchanger of the present invention, at least one end of a plurality of tubes arranged in parallel with each other is inserted into a burring provided in a tube insertion hole of the header tank. A laminated heat exchanger that is joined to the header tank by integral brazing, wherein the joining surfaces of the burring are attached to the inner tip of the burring projecting into the header tank in the direction in which the burring projects. Formed into an expanding shape and said
The burring is formed by cutting a header tank forming plate with a hole forming jig, and the burring is formed by providing a wedge-shaped brazing portion between the tube and the tube. The inner tip portion of the burring is a cut surface of the plate cut by the hole forming jig.

[0011]

In such a header tank, when a flat tube is inserted into each of the tube insertion holes of the header tank to perform integral brazing, the molten brazing material is interposed between the joint surface of the burring and the flat tube. While entering
The brazing material accumulates in the wedge-shaped brazing portion, and the brazed joint between the burring and the flat tube is performed without the molten brazing material flowing out of the tube insertion hole between the burring and the flat tube and coming out.

[0012] Therefore, since the brazing portion in which the joining surfaces of the burrings are formed so as to expand toward each other in the protruding direction of the burring is provided at the inner end portion of the burring provided in the tube insertion hole, the burring is flattened in the tube insertion hole. When the tube is inserted and brazed, a brazing portion is formed at the inner end portion of the burring, and reliable brazing between the joint surface of the burring and the flat tube becomes possible. As a result, the brazing property of the flat tube during brazing is improved, and airtight leakage between the joint surface of the burring and the flat tube due to poor brazing can be reliably prevented, thereby improving the yield of heat exchanger manufacturing. Can be planned.

[0013]

An embodiment 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 FIG. 2, both of the header tanks 4 are composed of a tank plate 5 and an end plate 6 which are divided in a direction perpendicular to the air flow direction A. As shown in FIG.
Is closed by Further, as shown in FIGS. 3 and 4, tube insertion holes 7 are formed in the end plates 6 of the header tanks 4 facing each other.
Are provided corresponding to the arrangement intervals.

As shown in FIGS. 3 and 4, the end plate 6 has a bulging portion 11 having a shape in which the surface between the tube insertion holes 7 bulges outward.
Is formed. That is, the bulging portion 1 curved between the tube insertion holes 7 in the circumferential direction and the axial direction of the end plate 6.
1 to prevent a decrease in strength due to the formation of a large number of tube insertion holes 7.

Each of the tube insertion holes 7 is, for example, as shown in FIG.
As shown in FIG. 2, the mold 17 and the hole forming jig 16 are formed at the same time as the bulging portion 11, and as shown in FIGS.
A burring 12 is formed in a portion of the bulging portion 11 close to the tube insertion hole 7.
2a is a flat tube 2 inserted into the tube insertion hole 7.
The flat tube is formed on a plane parallel to the flat surface of the flat tube so as to follow the flat surface.

Further, at the inner end portion of the burring 12, that is, at the end portion of the burring 12 located in the end plate 6, the joining surface 12a is formed into a tip shape which spreads outward to approximately half the thickness of the burring 12. A wedge-shaped space portion 13 is formed between each of the flat surfaces of the flat tube 2 inserted into the tube insertion hole 7 and the front end surface that spreads outward. Department.

The burring 12 and the brazing pool 13 are formed, for example, by a mold 17 and a hole forming jig 16 as shown in FIGS. 11 is formed at the same time as forming the same.
That is, a hole forming jig 16 formed in a plate shape having a predetermined thickness and a predetermined width and provided with a linear blade portion 15 at a distal end portion is cut into the insertion opening 18 of the mold 17 from the beginning of pressing. By the pressing force until the end is formed, a V-shaped depression 19 corresponding to the blade portion 15 of the hole forming jig 16 is formed in the end plate 6, and then the end plate 6 is cut along the depression 19 to form a tube. Insertion hole 7 and burring 12
The joining surface 12a of the burring 12 as shown in FIG.

In such a header tank 4, when the flat tube 2 is inserted into each of the tube insertion holes 7 of the end plate 6 mounted on the tank plate 5 to perform integral brazing, FIG. As shown, the molten brazing material 20 enters between the joint surface 12a of the burring 12 and the flat tube 2, and the brazing material 20 is stored in the wedge-shaped brazing portion 13.
Is the burring 12 of the tube insertion hole 7 and the flat tube 2
Without entering the gap between the burring 12 of the tube insertion hole 7 and the flat tube 2, and the joining surface 12 a of the burring 12 and the flat tube 2 are brazed.

Therefore, by forming the joining surface of the burring at the inner end portion of the burring so as to extend outward to approximately half of the burring thickness, a wedge-shaped solder pool is provided at the inner end portion of the burring. Reliable brazing between the joint surface of the burring and the flat tube can be performed. As a result, the brazing property at the time of brazing the flat tube is improved, and the airtight leak between the joint surface of the burring and the flat tube due to poor brazing can be reliably prevented,
The yield of heat exchanger production can be improved.

In the above-described embodiment, the inner end portion of the burring, that is, the end portion of the burring located in the end plate is formed so that the joining surface extends outward to approximately half the burring thickness. Has described the case where the wax pool is provided at the inner end portion of the burring. However, the present invention is not limited to this, and the wax pool may be provided by forming a shape as shown in FIG. 8 or FIG.

The brazing portion 13 shown in FIG. 8 is formed at the tip of the inside of the burring 12 so as to extend outward over the entire thickness of the burring 12.
In the brazing portion 13 shown in FIG. 9, the inner tip portion of the burring 12 is formed in a tip shape bent so as to spread outward, and the same effect as in the above embodiment can be obtained.

Although the description has been given of the case where the header tank is applied to a header tank composed of a tank plate and an end plate, the present invention is not limited to this. Further, in the embodiment, the case where the header tank is provided at both ends of the tube has been described.
The present invention is not limited to this, and can be applied to, for example, one having a header tank 4 on only one side as shown in FIG.

[0025]

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 burring provided in a tube insertion hole of a header tank, and the tube is inserted into the header tank. an integral brazed laminated heat exchanger to be joined by the inside tip portion of the burring projecting header tank, the bonding surface of the burring toward the projecting direction of the burring is formed in a shape spreading from each other and A wedge-shaped solder pool portion provided between the tube and the tube; the burring is formed by cutting a header tank forming plate with a hole forming jig; The inner tip portion of the burring constituting a portion is a cut surface of the plate cut by the hole forming jig, so that Since wax reservoir of wedge shape inner end portion of the grayed are formed, reliable brazing the burring joint surface and the flat tubes is possible. As a result, the brazeability of the flat tube during brazing is improved, airtight leakage between the burring joint surface and the flat tube due to poor brazing can be reliably prevented, and the production yield of the heat exchanger is improved. Can be achieved.

[Brief description of the drawings]

FIG. 1 is a front view showing a heat exchanger according to one embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a header tank.

FIG. 3 is a front view of an end plate.

FIG. 4 is a side view of an end plate.

FIG. 5 is a vertical sectional view of a header tank.

FIGS. 6A to 6C are a perspective view and a longitudinal sectional view showing a state in which a hole forming jig and a tube insertion hole are formed.

FIG. 7 is a longitudinal sectional view of an end plate showing a brazing state during brazing.

FIG. 8 is a longitudinal sectional view showing a burring shape according to another embodiment of the present invention.

FIG. 9 is a longitudinal sectional view showing a burring shape according to another embodiment of the present invention.

FIG. 10 is a perspective view of a single-tank type stacked heat exchanger according to another embodiment of the present invention.

FIG. 11 is a longitudinal sectional view showing a conventional header tank.

[Explanation of symbols]

 Reference Signs List 1 heat exchanger 2 flat tube 4 header tank 7 tube insertion hole 12 burring 13 wax pool

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-17396 (JP, A) JP-A-51-134256 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F28F 9/00-9/26 B21D 19/08 B23K 1/00 330 B23K 1/14

Claims (1)

(57) [Claims] At least one end of a plurality of tubes arranged in parallel with each other is inserted into a burring provided in a tube insertion hole of a header tank, and is joined to the header tank by integral brazing. in exchanger, the inside distal end portion of the burring projecting header tank is formed in a shape joining surface of the burring toward the projecting direction of the burring spreads each other and said Ju
The burring is formed by cutting a header tank forming plate with a hole forming jig, and further forms the brazing pool portion. The header tank of a heat exchanger, wherein the inner end portion of the burring is a cut surface of the plate cut by the hole forming jig.