JPH0233032Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a joint between a tube and a tube plate of a heat exchanger.

[Prior art]

A large number of tube insertion holes are formed in the tube plate of the heat exchanger, and the end portions of the tubes are fitted into the holes, and the fitting portions are joined in a fluid-tight manner. This tube plate is attached to close the opening of the tank body.
The joint between the hole in the tube plate and the tube is required to have high joint strength, and
It is necessary to ensure the sealing performance. in general,
The joints are joined by brazing or welding. Although this brazing has excellent sealing performance, it has the disadvantage of relatively low bonding strength. In addition, when welding is used, although the joint strength is strong, there are problems with sealing performance. Therefore, in recent years, proposals have been made to further cover the welding material with a brazing material after welding.

[Problem to be solved]

However, all welding and brazing metal coating had to be done from the inner surface of the tube plate. This is because a large number of tubes are inserted through the outer surface of the tube plate in parallel to each other, and fins are joined between them. In such a case, if welding and brazing metal coating are performed from the inner surface of the tube plate, the brazing layer and welding layer will be formed only on the inner surface of the tube plate.

[Means for solving problems]

Therefore, the present invention forms a flow path 4 for the brazing material from the inner surface to the outer surface of the tube plate 1,
A brazing material layer 6 is also formed on the outer surface of the tube plate 1, and its structure is as follows.

That is, a plurality of holes 2 are formed in the tube plate 1, and the ends of the tubes 3 are inserted into each hole 2. The insertion portion is joined in a fluid-tight manner. Here, the feature of the present invention is that one or more flow passages 4 for the brazing material are formed on the inner surface of the hole 2 or on the outer surface of the end of the tube 3. Then, leaving the flow passage 4, the insertion part of the end of the tube 3 is welded from the inner surface side of the tube plate 1 to form a weld layer 5.
form. Then, a molten brazing material is applied from the inner surface of the tube plate 1, and the molten brazing material is guided to the outer surface of the tube plate 1 through a flow path 4, and a brazing material layer 6 is formed there. .

[Effect]

Therefore, according to the present tube plate joint, the presence of the flow path 4 allows the brazing metal layer 6 to be formed around the tube insertion portion on the outer surface of the tube plate 1, and the welding layer 5 to be formed on the inner surface of the tube plate 1. Since it is formed, it is easy to manufacture and can satisfy both the strength and sealing properties of the joint.

〔Example〕

Next, one embodiment of the present invention will be described based on the drawings.

Figure 1 is a vertical sectional view of the main part of the main joint, and
The figures to FIG. 4 show the order for forming the joint portion. In this embodiment, a plurality of holes 2 are formed in a tube plate 1 at a distance from each other, and the edges of the holes form a slightly raised burring portion. Next, the tube 3 is a flat tube that substantially matches the hole 2, and has a groove-shaped flow path 4 formed at its end, for example. The flow path 4 only needs to be a gap that allows the molten brazing material to flow between the hole 2 and the tube 3, as shown in FIG. It is sufficient that the fluid flows from the inner surface to the outer surface. Therefore, the flow path 4 may have a depth of about 0.2 to 0.4 mm. Further, in this drawing, two flow passages 4 are formed in one tube 3, but the present invention is not limited to this, and more flow passages 4 may be formed. Further, the shape of this flow path 4 can be arbitrarily selected.

To form the actual brazed structure, first, the end of the tube 3 is inserted into the hole 2 of the tube plate 1 as shown in FIG. 2, and the structure is constructed as shown in FIG. Then, as shown in Figure 4, tube plate 1
The insertion portion of the tube 3 is welded from the inner surface side to form a weld layer 5 there. Note that this welding layer 5
is formed excluding the flow path 4. Next, the tip of the tube 3 and the inner surface of the tube plate 1 are dipped from the inner surface of the tube plate 1 into a brazing filler metal tank (not shown) containing a melted brazing filler metal. Then, the brazing material is sucked up to the outer surface of the tube plate 1 through the flow path 4, and forms a brazing material layer 6 at the hole edge on the outer surface. Of course, a brazing material layer 6 is also formed on the inner surface of the tube plate 1 as shown in FIG.

[Effect of idea]

The tube plate joint of the present invention has the above structure and has the following effects.

(1) At this joint, the insertion portion of the tube 3 is welded from the inner surface of the tube plate 1, leaving the flow path 4, to form the weld layer 5. Then, a molten brazing material is applied from the inner surface of the tube plate, and the brazing material is guided to the outer surface of the tube plate through the flow path 4 to form a brazing material layer 6 there. Therefore, due to the presence of the flow path 4, the welding layer 5 and the brazing material layer 6 can be formed from the inner surface of the tube plate 1, and the brazing material layer 6 can be guided to the hole edge on the outer surface of the tube plate 1 during manufacture. A liquid-tight structure that is easy and reliable can be provided.

(2) The presence of the welding layer 5 can increase the bonding strength between the tube plate 1 and the tube 3, and the presence of the brazing metal layer 6 can ensure sealing performance.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view showing the main parts of the tube-plate joint of the present invention, and FIGS. 2 to 4 are explanatory perspective views for explaining the manufacturing process for constructing the joint. 1...tube plate, 2...hole, 3...tube, 4...flow path, 5...welding layer, 6...brazing metal layer.

Claims (1)

[Scope of utility model registration request] At a tube plate joint portion of a heat exchanger where the end portions of tubes 3 are inserted into a plurality of holes 2 formed in tube plate 1, and the insertion portions are liquid-tightly joined, the inner surfaces of the holes 2 or the tubes are connected to each other. 3
One or more flow passages 4 for brazing filler metal are formed on the outer surface of the end of the tube, and the insertion portion at the end of the tube 3 is welded from the inner surface of the plate 1, leaving the flow passage 4, to form a weld layer 5. At the same time, a molten brazing material is applied from the inner surface, and the molten brazing material is guided to the outer surface of the tube plate 1 through the flow path 4, and a brazing material layer 6 is formed there. Features tube plate joint of heat exchanger.