JPH1110384A - Brazing wire brazing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the joining efficiency and to prevent the development of defective joining by using a heat resistant metal-made thin cored wire filling brazing filler metal in the inner part as a fin fixed material together with a brazing wire for heat exchanger. SOLUTION: The metallic wire is formed into the cored wire 4 having hollow cross section and the powdery brazing filling metal 5 is filled in the inner part to make the brazing wire 10. Then, the butting surface, i.e., the slit of the metallic wire formed at the time of forming the cored wire 4, is closed at the room temp. and is opened at a little by heating at the time of brazing, to enable the formation of a melt-out part 9 of the brazing filler metal 5. The brazing wires 10 are welded and tack-welded to a fin 1 with a suitable interval. At this time, the brazing filler metal melt-out part 9 is made to the retracting position by about 90 deg. from the tack-welded point to avoid the closing. The brazing filler metal 5 is melted at the brazing temp. by charging in a heating furnace and the molten brazing filler metal 7 is flowed onto the joining surface between the fin 1 and the cored wire 4, and joined.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brazing wire and a brazing method, and more particularly to a brazing wire and a brazing wire for joining a large number of members to be joined at one time, such as joining fins of a heat exchanger. Related to brazing method.

[0002]

2. Description of the Related Art A conventional technique for joining fins of a heat exchanger will be described with reference to FIG. 3. In FIG. 3, (A) is an overall perspective view, and (B) is a support for fixing and supporting the fins. A plan view and a sectional view showing the shape of the rod, and (C) shows a welding state of the support rod and the fin. As shown in FIG. 1A, a large number of metal flat fins 1 of a heat exchanger are stacked one above the other and sandwiched by a vice 12 in a state where the fins 1 are kept spaced by spacers 2. And fix it. Next, a metal solid round bar-shaped support rod 40 shown in (B) is applied to the side surface of the fin 1 and, as shown in (C), each of the fin 1 and the metal is manually formed by electric resistance welding. The black round part 41 with the round bar is joined. Vice 1 holding plate fin 1 and spacer 2
Numeral 2 is to release the urging force by the vise 12 after the joining is completed to remove the spacer 2.

[0003]

In such a joining method, the number of joints to be joined becomes extremely large in proportion to the number of fins. During resistance welding, it is difficult to determine the target position of the welding electrode, and thus poor fusion is likely to occur. Therefore, the quality of the joint is not always good. SUMMARY OF THE INVENTION In view of the above technical problems, the present invention relates to a brazing wire and a brazing method capable of joining a large number of members to be joined with high efficiency without occurrence of defective fusion, such as joining of fins of a heat exchanger. The purpose is to provide.

[0004]

According to the first aspect of the present invention, there is provided a cored wire having a hollow portion formed along an axis and a brazing material elution portion formed between the hollow portion and an outer surface.
And a brazing wire made of the brazing material 5 filled in the hollow portion 8. As shown in FIG. 2A, the metal wire 4 is formed into a C-shaped cross section, and the C-shaped slit portion is made to function as a brazing material eluting portion 9 while filling the inside with a powdered brazing material 5 as shown in FIG. Can be configured. Further, the brazing material elution portion 9 is closed at room temperature, and may be opened in a slit shape so that the brazing material 5 can be eluted during heating. Also, the brazing material elution portion 9 is not necessarily formed in a slit shape, but may be formed in a dotted line or a cored wire 4 along the axial direction.
May be formed in such a manner that a part thereof is thinned and the part is eluted by heating.

As a technique similar to the present invention, there is a flux-cored welding rod, which welds itself, and in the present invention, the cored wire 4 does not melt,
It functions as a fixed support, and the eluted brazing material 5 contributes to joining, and has a different basic idea.

According to a second aspect of the present invention, the brazing wire 4 is heated by heating the brazing wire 4 to elute the brazing material 5 from the brazing material elution portion 9 to the outer surface side of the cored wire 4. It is a feature.

According to the invention, a large number of members to be joined 1 are brazed by a brazing wire 10 like a fin joint of a heat exchanger.
When the wire 10 is temporarily fixed to the member 1 to be joined, the wire 10 is filled with the powdered brazing material 5 only by heating the plurality of welding points to the brazing temperature. Therefore, the brazing material 5 is eluted and flows into the gap with the member 1 to be joined by capillary action or the like, and can be joined at one time, so that the number of joining steps can be reduced and it is economical. Further, since the brazing material 5 flows into the gap (joined portion) between the member 1 to be joined and the wire 10 and enters in a molten state,
There is no defect such as poor fusion, and the quality of the joint is good.
The elution heating of the brazing material 5 may be performed by igniting a fire at the joint. However, it is preferable to put the product body as the member to be joined 1 in a heating furnace and raise the temperature because deformation after heating is small.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, and are merely illustrative examples. Only.

FIG. 2A shows a brazing wire according to an embodiment of the present invention. As described above, a metal wire 4 is formed into a hollow C-shaped cross section (hereinafter referred to as a cored wire 4), and a powder brazing material 5 is contained therein. And the C-shaped slit portion is made to function as a brazing material elution portion 9. Cored wire 4
Is formed into a tubular shape by rolling a flat material into a tubular shape and at the same time filling the powdered brazing material 5, but the C-shaped slit portion 9 tends to open by heating when heated. The C-shaped slit portion 9 may be configured to be closed at room temperature and open slightly in a slit shape such that the brazing material 5 can be eluted during heating.

FIG. 2B shows a state in which the brazing wire is temporarily fixed to the fin 1 or its supporting member 13 by electric resistance welding or the like, and FIG. 2C shows a state where the joint of the brazing wire 10 is heated. This shows a state in which the brazing material 5 is eluted and joined. In the figure, reference numeral 6 denotes a weld metal obtained by electric resistance welding, and reference numeral 7 denotes a brazed metal after brazing. It is preferable that the C-shaped slit portion 9 is fixed so as to be located at an angular position retracted by about 60 to 150 °, preferably about 90 ° from the welding position so as not to be closed at the time of temporary fixing welding.

Next, a technique according to an embodiment of the present invention for joining the fins 1 of the heat exchanger will be described with reference to FIG. 1. First, the upper and lower support plates 13 of the heat exchanger and a large number of metal flat plates will be described. The support plate 13 and the fin 1
Each of the members is clamped and fixed with a vice 12 in a state where the spacers 2 hold the spaces therebetween.

Next, a brazing wire 10 is brought into contact with the side surface of the fin 1 as shown in FIG.
Temporarily welding to the state of (B). At this time, a part of the cored wire 4 which is the outer shell of the wire 10 is temporarily attached to the melting fin 1.
Does not dissolve. The tack welding may be performed at appropriate intervals between the upper and lower support plates 13 and the fins 1, and there is no need to weld all the fins 1.

Next, the wire in the state shown in FIG. 1A to which the wire 10 is temporarily attached is heated in a vacuum heating electric furnace (not shown). The heating temperature depends on the melting temperature of the powder brazing material 5. For example, about 1050 for nickel brazing
C. and about 800.degree. C. for copper brazing. When heated to the above-mentioned temperature, the powdered brazing material 5 melts out, and the outflowing brazing material 7 flows to the fin 1 side to find a gap (a phenomenon similar to a capillary phenomenon), and as shown in FIG. It is led out to the joint of the fin unit 1.

Therefore, it is natural that the cored wire 4 is made of a heat-resistant metal which does not melt even in the above-mentioned state. A slightly meandering state as shown in FIG.

[0015]

As described above, according to the present invention, a large number of members to be joined can be joined with high efficiency without the occurrence of defective fusion as in the joining of the fins 1 of the heat exchanger.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention for joining fins of a heat exchanger, (A) is an overall perspective view thereof, (B) and (C).
FIG. 3A is an enlarged view of a circle of FIG.

2 (A) is a brazing wire 4 according to an embodiment of the present invention, and (B) is a state in which the brazing wire 4 is temporarily fixed to a fin or its supporting member by electric resistance welding or the like,
(C) shows a state in which the joining portion of the brazing wire 4 is heated and fully joined.

3A and 3B show a conventional technique for joining fins of a heat exchanger, wherein FIG. 3A is an overall perspective view, and FIG. 3B is a plan view and a sectional view showing the shape of a support rod for fixing and supporting the fins. ,
(C) shows the welding state of the support rod and the fin.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fin 2 Spacer 4 Cored wire 40 Solid support rod 5 Powder brazing material 6 Electric resistance welding metal 7 Brazing metal 8 Hollow part 9 Brazing material elution part 10 Brazing wire

Claims (2)

[Claims] 1. A hollow portion formed along an axis, a cored wire having a brazing material elution portion formed between the hollow portion and an outer surface, and a brazing material filled in the hollow portion. Brazing wire to do. 2. A brazing method, characterized in that the brazing wire according to claim 1 is heated to elute the brazing material from the brazing material elution portion to the outer surface side of the cored wire.