JP2622995B2 - Precision brazing method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a precision brazing method for performing high-quality brazing on a brazed member having a brazing surface communicating with an opening.

(Prior Art) Conventionally, for parts that require only brazing strength, such as heat exchangers, the quality of the parts is determined by checking gas leakage at the brazing part. However, for components that require high reliability, such as waveguides and vacuum components,
The above check items are not enough, and furthermore, the brazing surface needs to flow smoothly and be brazed precisely.

Various measures have been taken to make the flow of the wax smooth according to this need. For example, as shown in FIG. 7, a small gap 32 (for example, 1) is formed between the brazing material 30 (having the core material 30a and the brazing material 30b clad on both surfaces) and the brazing surface of the brazed member 31. / 100 mm), and the brazing material 30 is further projected from the brazing end surface of the brazing member. If brazing is performed in this state, the protruding extra braze 30b smoothly flows into the minute gap 32 due to capillary action, and brazing is performed in a flowable state. Thereafter, the protruding braze 30 is scraped off, and the brazing operation is completed.

(Problems to be solved by the invention) However, recently, there has been a demand for reliability for precision parts,
There is a problem that the requirements are not sufficiently satisfied by the conventional method because the height has become higher and the shape of the parts has become more complicated. Further, such reliability is likely to be impaired when brazing to the open end of the brazed member while evacuating.

The reason why the quality of brazing tends to deteriorate in the above brazed member is as follows.

That is, when heating the member to be brazed, moisture, oil, and the like adhering to the member evaporate and become a gas, and this gas flows according to evacuation, and this gas flow obstructs the flow of the braze and brazes. It is thought to reduce the quality. Moreover, the generation of the above gas is further promoted by evacuation.

When a honeycomb panel as shown in FIG. 8 is manufactured by vacuum brazing, a brazing material 36 is disposed on the inner surfaces of the flat plates 35, 35, and a side panel 37 is disposed between the flat plates 35, 35. doing. However, during brazing, the pressure difference between the inside and outside of the side panel 37 is large (the inside of the side panel 37 is in a sealed state), and the state of the brazing flow is different. There is a problem that a large difference occurs in the size (capacity) of 38.

SUMMARY OF THE INVENTION The present invention has as its basic object to solve the above problems, and provides a precision brazing method capable of improving a brazing flow of a brazing surface communicating with an opening and performing good brazing. is there.

(Means for Solving the Problems) In order to achieve the above object, a precision brazing method according to the present invention includes a method for precision brazing a member to be brazed having an opening and a brazing surface communicating with the opening. Wherein the brazing surface is blocked from the opening, brazing is performed, and then the blocking is released.

The shape and position of the opening are not limited, but may be any as long as they have an opening according to the purpose of use of the member.

If there is more than one brazing surface communicating with this opening,
At least one desired brazing surface is blocked to break communication with the opening.

In the blocking method, the opening is blocked by the brazing member itself, a brazing material, another member, or the like. In addition, it is also possible to block off the opening and the brazing surface halfway, instead of the opening.

This blockage is the space that contains the brazing surface of interest,
It is performed so as to obtain almost hermeticity. Next, the brazing is terminated in the cut-off state, and the brazing member itself and the brazing material used in the above-described blocking method are cut or the other members are removed to release the cut-off and the brazing operation is completed.

Further, it is desirable that the opposed brazing surfaces be separated by the core material of the brazing sheet.

(Operation) That is, according to the present invention, the desired brazing surface is disconnected from the opening and is in a sealed state, so that the space including the brazing surface is a closed space. Gas generated when the brazing member is heated is filled in this closed space, and gas generation is suppressed so as to maintain an equilibrium state. Therefore,
Gas flow generation is also prevented, adverse effects on the braze flow are eliminated, and good braze with good braze flow is achieved.

In the present invention, when vacuuming is performed to perform brazing under a specific atmosphere such as vacuum brazing or an inert gas, the closed space is not completely closed at the beginning of heating. Because it is difficult, it is in a reduced pressure state, after that, due to the increase in the adhesion of the brazing material due to heating, the tightness increases
The gas generated in the closed space is filled in the closed space.

It should be noted that the present invention is not limited to brazing under a specific atmosphere as described above.

And, after brazing, by unblocking,
The desired brazed member is obtained.

Further, if the opposing brazing surfaces are separated by the core material of the brazing sheet, the brazing brazing surfaces do not flow into the other brazing surfaces. Therefore, even when there is a large difference in the heat capacities of the opposing brazing surface portions, an appropriate amount of brazing material flows on each brazing surface, and good brazing can be performed without being restricted by the shape of the brazing portion. it can.

(Embodiment 1 and Embodiment 2) Hereinafter, an embodiment of the present invention will be described with reference to FIG. 1 and FIG.

In this embodiment, brazing is performed so as to form a stepped flange 2 made of an aluminum alloy with both brazed members on both end surfaces of a tube material 1 made of an aluminum alloy which is a brazed member.

That is, the tubular member 1 and the stepped ring member 3 for the stepped flange are prepared.

Further, a circular brazing material 4 having the same diameter as the outer diameter of the tube material 1 is prepared. This circular brazing material 4 was obtained by laminating aluminum brazing on both surfaces of an aluminum alloy core material (not shown).
These are arranged at both ends (openings) of the tube material 1 respectively. The tubular member 1 and the circular brazing member 4 are fitted into the steps of the stepped ring member 3 and placed in a vacuum furnace (not shown). In this vacuum furnace, heating is performed while evacuation is performed.

In this manner, the tube 1 and the stepped ring member 3 are joined by welding the brazing material 4 to the tube material 1 by welding at a predetermined temperature for a predetermined time. A pipe with a flange is obtained by communicating with the ring material 3 (FIG. 2).

The space A surrounded by the pipe 1 and the circular brazing material 4 is
Although almost in a sealed state, the pressure is reduced according to the evacuation through a small gap. On the other hand, according to the heating, gas is generated from the brazed member such as the tube material 1 by evaporation of moisture and the like, and the space A is filled. by the way,
As the heating proceeds, the adhesion to the brazing surface increases, and the airtightness of the space A increases. For this reason, drawing out of gas from the space A due to vacuuming is prevented. Therefore, in the space A, chemical equilibrium is established as a closed space, and generation of gas is suppressed. For this reason, the reduction that the gas flow disturbs the brazing flow is prevented, and good brazing is performed.

It should be noted that the brazing to the opposing brazing surface is isolated by the core material of the circular brazing material 4, so that each brazing does not flow into the other brazing surface, thereby preventing brazing failure due to a difference in heat capacity or the like. be able to.

Next, in Example 2, as shown in FIG. 3, a ring brazing material 5 was used in place of the circular brazing material as shown in FIG. Further, in this embodiment, the stepped ring material 3
, A stepped disk 6 is used.

In the second embodiment, as in the first embodiment, brazing is performed to remove excess ring brazing material 5, and a central portion of the stepped disk 6 is hollowed out to obtain a flanged tube.

In the second embodiment as well, disturbance of the brazing flow due to the gas flow is prevented, and good brazing is performed.

In the second embodiment, since the brazing filler metal has a necessary amount, no trouble is caused by a proper amount of the brazing filler metal. On the other hand, in Example 1, since the brazing filler metal is circular,
When the diameter of the tube material increases, the amount required for brazing
Since a large amount of wax is excessive, there is a possibility that troubles such as partial accumulation of the wax may occur.

Therefore, the second embodiment is suitable for a large-diameter tube or the like.

Embodiment 3 Next, another embodiment will be described with reference to FIGS. 4 and 5. FIG.

That is, a disk-shaped brazing material 11 having the same diameter as the outer diameter of the tube material 10 is brought into contact with an end surface (opening) of the tube material 10 which is a brazing member. The open end of the bottomed cylindrical member 13 is brought into contact. In this state, it is placed in a vacuum furnace (not shown) and heated while evacuating. The space B surrounded by the brazing material 11 and the bottomed cylindrical material 13 is substantially sealed (the other end of the tube material 10 is also sealed), and the space B is evacuated similarly to the above embodiment. Is also depressurized and later filled with gas. Therefore, similarly to the above-described embodiment, the generation of gas is suppressed by the chemical equilibrium, and the brazing flow is improved.

Furthermore, after welding the pipe material 10 and the bottomed cylindrical material 13 through the core material of the brazing material 11 by welding of the brazing material, the brazing material 11 and the bottomed cylindrical material 13 are hollowed out in a circular shape, and a flanged tube is formed. Get your body (Figure 5).

In this embodiment, since the flange portion was brazed directly to the end face of the pipe member 10 via the pipe portion 13a, the difference in heat capacity between the opposed brazing surfaces was reduced. And good brazing can be performed. Further, since the opposed brazing surfaces are isolated by the brazing material core, one of the brazing materials does not go around the other, so that a bad brazing flow can be prevented.

Embodiment 4 Further, another embodiment will be described with reference to FIG.

The fourth embodiment relates to a method of brazing by forming a side panel 21 which is also a brazing member between flat plates 20 and 20 which are brazing members so as to form a honeycomb panel.

That is, the brazing material 22,
A side panel 21 is disposed between the brazing materials 22,22.

In addition, the flat plates 20 and 20 have extra dimensions to the left of the drawing than required dimensions, and a shielding panel 23 is disposed at the left end thereof to block an opening between the flat plates 20 and 20. ing.

Also in the method of the fourth embodiment, the space C surrounded by the flat plates 20, 20, the side panel 21, and the shielding panel 23 is almost in a sealed state, and the gas is heated during the heating of the brazing as in the previous embodiment. Is filled, gas generation is suppressed, and poor brazing can be prevented.

After the brazing heat, the flat plates 20, 20 and the brazing material 22 are cut off along the cutting line 25 to obtain a honeycomb panel.

In this embodiment, a fillet formed by brazing
26 is formed with the same capacity inside and outside the side panel 21,
A stable fixed state is obtained.

In each of the above embodiments, the case of brazing with aluminum brazing to the brazed member made of aluminum alloy was described, but as the present invention, the material of the brazed member is not limited to this, For example, it can be applied to a brazing member made of stainless steel or a titanium alloy. In this case, the material of the brazing material may be selected according to the material of the member to be brazed.

(Effects of the Invention) As described above, according to the present invention, in the method for precision brazing of a brazed member having an opening, at least one of the opposed brazing surfaces communicating with the opening is blocked from the opening. Since the brazing is performed and then the cutoff is released, there is an effect that the gas flow on the brazing surface is suppressed, the flow of the brazing is improved, and precise brazing can be performed.

Further, if the opposing brazing surfaces are separated by a brazing material core material, it is possible to prevent one brazing material from flowing into the other brazing surface side, and to perform brazing between portions having different heat capacities well. There is an effect that can be.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a state before brazing according to an embodiment of the present invention, FIG. 2 is a sectional view showing a state after completion of brazing, and FIG. 3 is a state before brazing according to another embodiment. FIG. 4 is a cross-sectional view showing a state after the completion of brazing, FIG. 5 is a cross-sectional view showing a state before brazing in another embodiment, and FIG. 6 is another embodiment. FIG. 7 is a partially enlarged sectional view showing a state before brazing in a conventional example, and FIG. 8 is a cross-sectional view showing a state before brazing in still another conventional example. FIG. 1, 10… tube material, 2… stepped flange 4… circular brazing material, 5… ring brazing material 6… stepped disc, 11… brazing material 13… bottomed tubular material, 20… Flat plate 21: Side panel 23: Shielding panel 26: Fillet

Claims (2)

(57) [Claims] 1. A precision brazing method for a brazed member having an opening and having a brazing surface communicating with the opening, wherein the brazing surface is cut off from the opening to perform brazing. After that, the brazing method is characterized by unblocking. 2. The brazing sheet according to claim 1, wherein the brazing surfaces facing each other are separated by a brazing sheet core.
The precision brazing method described.