JPH049631B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of brazing fins, such as a method of brazing fins for promoting radiation heat transfer to a tube.

[Prior Art] Fig. 5 is a longitudinal cross-sectional view showing a method of brazing fins, which is carried out, for example, in the heat exchange of a conventional Stirling engine. A certain heater tube, 2, is for promoting heat transfer by radiation heat transfer, and a fin having a flange 2a, 3 is a brazing material for thermally coupling the heater tube 1 and the fin 2 by brazing.

FIG. 6 is a longitudinal cross-sectional view of the fin 2. FIG.

Next, the steps of the brazing method will be explained. Fifth
As shown in the figure, a plurality of fins 2 are arranged in parallel around a heater tube 1 so that their inner peripheries are in contact with the heater tube 1, and a brazing material 3 is applied around the fins 2.
Next, this is placed in a furnace and brazed in the furnace.
A large number of defective brazing parts 5 as shown in the figure occur. In this brazing defective portion 5, the adjacent fins 2 are brazed together, and the heater tube 1 and the fins 2 are not in close contact with each other by the brazing material.

Therefore, a heat insulating layer of air is formed between the fins 2 and the heater tube 1, and the fins 2 no longer function as a heat transfer promoting member. The reason for this is that, as shown in FIG. 6, since the fins 2 are manufactured by punching with a press, the bent portions of the fins 2 are not at right angles, and a portion having a curvature is inevitably formed. Therefore, as shown in FIG. 5, when the fin 2 is inserted into the heater tube 1, the adjacent fin 2
If a gap A occurs between the fins 2 and the brazing metal is applied from the outside of the fins 2, the brazing metal 3 will suddenly retract when the adjacent fins 2 are in close contact with each other in front of the gap A during brazing in the furnace. However, because of the gap A, the flow of the brazing material 3 is stopped, and a defective region 5 of the brazing material 3 as shown in FIG. 7 occurs.

[Problem that the invention seeks to solve]

Since the conventional fin brazing method is configured as described above, the heater tube 1 as shown in FIG.
Many defects occurred in which the fins 2 were not soldered and adjacent fins 2 were soldered together. Also,
It is very difficult to press the bent portion of the fin 2 at right angles, and it is almost impossible to apply the brazing material 3 to the gap A between the fin 2 and the member 1 to be joined.

This invention was made to solve the above-mentioned problems, and it is possible to reliably braze the fin 2 to the heater tube 1 without changing the bending part of the fin 2 or the method of applying the brazing material to the conventional method. The purpose of this invention is to obtain a method for brazing fins.

[Means for solving problems]

A method for brazing fins according to the present invention includes forming irregularities on the edge of a contact portion of a fin having a hole passing through a member to be welded and a flange at the end thereof, and forming a plurality of fins in contact with the member to be welded. The fins are arranged in parallel so that the peripheries of the holes touch the peripheries of the parts to be welded, and the brazing material is poured between the inner circumference of the fins and the parts to be welded from the uneven surface to braze the fins and the parts to be welded. be.

[Effect]

The unevenness formed on the fin in this invention is
To make it easier for brazing material to flow between a member to be joined and a fin. This ensures that the brazing portion reaches the gap between the member to be welded and the fin, thereby eliminating defects where the fins are brazed together and the member to be joined and the fin are not brazed together.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view showing a state in which a fin is brazed to a member to be joined. In the figure, 1 is a member to be joined, such as a heater tube, 4 is a fin for promoting heat transfer, and 3 is a wax for thermally bonding the heater tube 1 and fin 4 by brazing. It is a material.

FIG. 2 is a cross-sectional view of the fin 4, which has a flange 4a at one end, a hole that penetrates the member 1 to be welded, and an uneven surface 4 at the edge of the contact portion with the member 1 to be welded.
For example, the unevenness 4b is formed by cutting the fin 4 into a wave shape.

Next, the steps of the brazing method will be explained. 1st
As shown in the figure, a plurality of fins 4 having unevenness 4b are inserted and arranged in parallel around the heater tube 1 so that the periphery of the hole contacts the heater tube 1.
Apply waxing material 3 around it. At this time, Finn 4
Since one end surface is cut out in a wave shape, the brazing material enters from the recessed part of the fin 4 to the heater tube 1, and the contact between adjacent fins 4 is only at the convex part due to the wave shape. Therefore, during brazing in the furnace,
Where the adjacent Finn 4 comrades are in contact,
Since the brazing material 3 is not drawn in suddenly and the brazing gap does not suddenly shrink or expand, the brazing material 3
As shown in the figure, brazing is reliably performed between the heater tube 1 and the fins 4. Furthermore, since the brazing material 3 is used for brazing without waste, the weight of the joined product can be reduced, and the flow of the brazing material 3 becomes smooth, improving the workability of applying the brazing material 3.

In addition, in the above embodiment, the member to be joined 1 of the fin 4
As shown in FIG. 4, several slit-like notches are cut out on the edge of the contact area of the fin 4 with the member 1 to be welded. Alternatively, the unevenness 4b may be formed. Furthermore, the material of the fins 4, the material of the heater tube 1, and the type of brazing material 3 are not specified.

〔Effect of the invention〕

As described above, according to the present invention, unevenness is formed on the edge of the contact portion of the fin, which has a hole passing through the welded member and has a flange at one end, with the welded member. The fins are placed side by side so that their peripheries touch the peripheries of the parts to be welded, and the brazing metal is poured between the inner periphery of the fins and the parts to be welded from the uneven surface to braze the fins and the parts to be welded. The present invention has the effect that a method for brazing fins that can reliably braze the fins with the members to be joined can be obtained.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view showing a method for brazing fins according to an embodiment of the present invention, FIG. 2 is a vertical cross-sectional view of a fin according to an embodiment of the present invention, and FIG. 3 is an embodiment of the present invention. FIG. 4 is a vertical cross-sectional view of a fin according to another embodiment of the present invention, and FIG. 5 shows a conventional fin brazing method. FIG. 6 is a vertical cross-sectional view of a fin according to a conventional fin brazing method, and FIG. 7 is a vertical cross-sectional view showing a fin brazed by a conventional fin brazing method. 1... Member to be joined, 3... Brazing material, 4... Fin, 4
a...Flange, 4b...Irregularities, and in the drawings, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Scope of Claims] 1. A fin having a hole passing through the member to be joined and a flange at one end has an unevenness on the edge of the contact portion with the member to be joined, and a plurality of fins,
The fins are arranged in parallel so that the periphery of the hole contacts the periphery of the member to be welded, and a brazing material is poured between the inner periphery of the fin and the member to be welded through the unevenness to braze the fin and the member to be welded. A method for brazing fins. 2. The fin brazing method according to claim 1, wherein the member to be joined is a tube and the fin is cylindrical. 3. The method for brazing fins according to claim 1 or 2, wherein the unevenness is formed by cutting the fins into a wave shape. 4. The fin brazing method according to claim 1 or 2, wherein the unevenness is formed by cutting the fin into a slit shape.