JPH0428995B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a heat exchanger used in automobile oil coolers, air conditioner heat exchangers, etc. The present invention relates to a heat exchanger constructed by brazing component parts together in a furnace.

(Prior art) Aluminum heat exchangers that are integrally brazed in a furnace using the VB method generally have a metal (e.g. aluminum) inlet with threaded holes for piping installation. A hole is provided around the opening in one end face of each of the joint and the exit joint, and the hole that fits into the annular protrusion formed integrally with each of these joints, and is connected to the entrance joint and the exit joint. The inlet and outlet joints and the core are temporarily assembled and then brazed together in a furnace.

FIG. 4 shows a core part 13 consisting of a core plate 2, a tube 3 each composed of a pair of tube plates 3a and 3b, and an inlet joint 1.
2 is a cross-sectional view of a part of a conventional heat exchanger in which points are brazed together, and an annular projection 9a integrally formed in the joint 1 around an opening 14 on one end surface of the inlet joint 1 is provided on the core plate 2. The threaded hole 7 for attaching the pipe is inserted through the joint 1 at a position close to the annular projection 9a.

In the structure shown in FIG. 4, when the inlet joint 1 and the outlet joint (not shown) are brazed together with the core part 13 in a furnace, the brazing material is attached to the annular protrusion 9a and the hole 9b. In addition, the brazing material clad on the surface of the core plate 2 travels along the bottom surface of the joint 1 and into the threaded hole 7 for installing the pipe due to surface tension and capillary action. This caused the inconvenience that the filler metal would clog the threads of the screw hole 7 and cause the screw hole 7 to malfunction.

In order to solve this problem, two proposals have been made in the prior art. One is to make the screw hole 7a for installing the pipe a cap screw hole 7a, as shown in FIG. forming a groove 8;
The purpose of this annular groove 8 is to trap the flow of brazing material toward the screw hole 7 during the brazing process.

(Problem to be solved by the invention) However, forming a blind screw hole as shown in Fig. 5 is difficult to process in a soft material such as aluminum, and it is necessary to ensure the effective number of screw threads. Therefore, it is necessary to increase the dimension indicated by A, which is disadvantageous in terms of mounting on a vehicle. Also, in the case where the annular groove 8 is formed as shown in Fig. 6, when the screw hole 7 and the annular groove 8 are close to each other (in Fig. 6,
If the dimensions shown in (a) are small, there is a drawback that the infiltration of the brazing material into the screw hole 7 cannot be completely prevented.

(Means for solving the problem) In the present invention, in the heat exchanger of the type described above, an annular groove is formed around the annular protrusion of each of the inlet joint and the outlet joint, and the annular groove and the An annular convex portion is formed on these joints around the annular groove between the joint and the hole.

(Function) The molten brazing filler metal used for brazing the joint and the core part passes between the annular protrusion of the joint and the hole of the core plate that fits into it, and creeps up due to its surface tension and capillary action. , the brazing metal on the surface of the core plate runs down the bottom surface of the joint,
Even if it tries to flow toward the screw hole for piping installation,
The annular groove and the annular protrusion catch the flow of the brazing material to prevent it from entering the screw hole.

(Example) An example of the present invention will be described with reference to FIGS. 1, 2, and 3.

The heat exchanger has a generally oval aluminum inlet joint 1 and an outlet joint 10 that constitute a joint for assembling piping, and these joints 1 and 10 have an inlet 5 and an outlet 6 for fluid, respectively. are penetrated therethrough, and screw holes 7 for piping attachment are penetrated on both sides of these inlets and outlets (see FIG. 2). Since the inlet joint 1 and the outlet joint 10 have the same structure, only one of them 1 will be described.

An annular protrusion 9a is formed on the periphery of the opening 14 of the inlet 5 on one end surface of the inlet joint 1, and is fitted into a hole 9b formed in the aluminum core plate 2, which is a component of the core part 13. There is. The core part 13 has a plurality of tubes 3 each formed by a pair of aluminum tube plates 3a, 3b, and an inlet opening 3a' is provided in the top wall of the enlarged portion of the tubes 3, and an inlet opening 3a' is provided in the bottom wall of the enlarged portion of the tubes 3. An outlet opening (not shown) is formed in the tube, and a plurality of tubes 3 are stacked with the inlet opening 3a' and the outlet opening aligned with each other. The top tube 3 is brazed to the core plate 2 with its inlet opening 3a' aligned with the hole 9b in the core plate 2. Furthermore, the bottom wall of the enlarged portion of the lowermost tube 3 has no outlet opening, and another core plate 11 is brazed to this bottom wall.

Aluminum corrugated fins 4 are inserted between the core plate 2 and the tube 3, between the tubes 3, and between the tube 3 and another core plate 11. and fins 4 constitute the core portion 13. The structure of the enlarged part on the outlet side of each tube 3 is the same as the structure of the enlarged part on the inlet side described above, and the difference is that in the enlarged outlet side, the opening formed in the bottom wall becomes the inlet opening The opening formed in the top wall serves as the exit opening. Thus, the outlet opening provided in the top wall of the enlarged portion of the uppermost tube 3 aligns with the hole (not shown) at the right end in FIG. 3 of the core plate 2. With the above configuration, the fluid to be heat exchanged (for example, oil) flows into the core portion 13 from the inlet joint 1, flows inside each tube 3 to the right in FIG. 3, and reaches the outlet joint 10. At this time, since cooling air is forced to flow through the air passages between the corrugated fins 4 of the core portion 13, heat exchange occurs between this air and the oil.

Both surfaces of the core plates 2 and 11 and the inner and outer surfaces of each tube plate 3a and 3b are coated with a brazing material. The annular projections 9a of the inlet joint 1 and the outlet joint 10 are fitted into the holes 9b of the core plate 2, and a plurality of tube plates 3a, 3b and another core plate 11 are connected to the corrugated fin as shown in FIG. After temporarily assembling and fixing 4 by stacking them with 4 interposed between them, they are brazed together in a furnace to form a heat exchanger. In order to solve this problem, in the present invention, an annular groove 1a is formed around the annular protrusion 9a of each of the inlet joint 1 and the outlet joint 10 as shown in FIG. In addition, this annular groove 1
An annular convex portion 1b is formed between the screw hole 7a and the screw hole 7.

Due to the annular groove 1a and the annular protrusion 1b formed in this way, the gap between the annular protrusion 9a and the hole 9b of the core plate 2 is created by surface tension and capillary action during brazing in a furnace. In addition to the molten brazing material passing through the core plate, excess brazing material on the surface of the core plate also flows through the screw hole 7.
It is prevented from creeping up towards the screw hole 7 and entering into the screw hole 7. That is, the annular groove 1a and the annular convex portion 1b
captures the excess brazing material heading toward the screw hole 7.

By configuring it in this way, the excess brazing filler metal is not allowed to enter the screw hole 7 even when the dimension A shown in FIG. 5 is not made large, and even when the dimension B shown in FIG. 6 is small. can be made certain.

In FIG. 1, an example of dimensions regarding the annular groove 1a and the annular convex portion 1b is shown. The width C of the annular groove is approximately
1.5mm, the depth E of the annular groove is approximately 0.5mm, the height D of the annular protrusion is approximately 1.5mm, and the total of dimensions D and E is approximately
It becomes 2.0mm. Note that the annular groove 1a and the annular convex portion 1
There is no particular correlation between the dimensions and b.

Although the above embodiments are made of aluminum heat exchangers, the present invention is of course applicable to heat exchangers made of other metals (eg, copper or alloys thereof).

(Effects of the Invention) According to the present invention, when a heat exchanger is constructed by brazing the components of the heat exchanger together in a furnace, the excess brazing material is used as a screw for installing the pipes at the inlet joint and the outlet joint. Since it is prevented from penetrating into the holes, a heat exchanger of stable quality can be obtained without causing malfunction of the screw holes.

[Brief explanation of drawings]

Figure 1 is a partially sectional side view of an aluminum heat exchanger that is an embodiment of the present invention, and -
Figure 2 is a plan view of the heat exchanger in Figure 1, Figure 3 is a front view of the heat exchanger, and Figures 4 to 6 are partial sectional views of conventional examples taken along the line. . 1...Inlet joint, 1a...Annular groove, 1b
...Annular convex portion, 2...Core plate, 3...Tube, 3a, 3b...Tube plate, 4...
...Colgate Finn, 5...Entrance, 6...Exit,
7... Screw hole for piping installation, 9a... Annular projection,
9b...hole, 10...exit joint, 11...
Another core plate, 13... core portion, 14... opening.

Claims (1)

[Scope of Claims] 1. An inlet joint through which a fluid inlet and a threaded hole for piping attachment are provided, an outlet joint through which a fluid outlet and a threaded hole for piping attachment are provided, and the inlet joint. and a metal member connected to the inlet and outlet joints, each having a hole on one end surface of each of the inlet and outlet joints that fits into an annular protrusion formed integrally with the inlet and outlet joints. In the heat exchanger, the inlet and outlet joints and the core part are brazed together in a furnace, and the one end surface of each of the inlet joint and the outlet joint has a core part including a core plate. . A heat exchanger characterized in that an annular groove is formed around the annular projection, and an annular protrusion is formed around the annular groove between the annular groove and the screw hole.