JPS59110460A - Joining method - Google Patents

Abstract

PURPOSE:To perform joining with improved joining efficiency by dipping the end of one pipe body to be fitted into the other pipe body by >=2 times in a molten solder bath to form a coating film having a collar-shaped thick walled part thereon then fitting the end to the end of the other pipe body. CONSTITUTION:The high pressure air introduced, via a guide pipe 16, into a pipe body 15 consisting of Al, etc. held by a holding body from its open end is ejected and in this state the joining end of the body 15 is dipped in molten solder 7. An ultrasonic oscillation is propagated, via an oscillation diaphragm 9, to the solder 7 to dislodge the oxide film from the outside circumferential surface on the above-described joining end and to stick the solder 7 on the fresh surface. The pipe body 15 formed with a primary solder film 18 on the joining end is removed upward from the solder 7 and is cooled. While compressed air is ejected from the above-described joining end, the body 15 is immersed in the solder 7 to form a secondary covering film 19 formed with a collar-shaped part 19a on the side opposite from the open end side of the body 15 on the film 18. The joining end of such body 15 upon cooling is fitted to a pipe body 20 consisting of, for example, copper, etc. and the joined part of both is heated to the solder melting temp. or above and is joined under application of an ultrasonic oscillation thereon.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a joining method suitable for joining dissimilar metal pipe bodies.

[Technical background of the invention and its problems]

In general, fusion welding of tubes made of dissimilar metals, such as copper and aluminum, is difficult. Therefore, a pair of dissimilar metal tube bodies are joined by soldering, that is, by soft soldering. In this case, one of the pair of dissimilar metal tubes is immersed in a solder bath, and a solder coating film (2
).

However, after fitting the joining end of the tube (1) to the other tube (3), the amount of solder is insufficient to heat it above the melting point of the solder, as shown in Figure 2. In this way, a solder rod (4) is wrapped around a small gap between the joints to replenish the amount of solder required for joining.

Attaching such solder # (4) to the joint requires a great deal of skill, especially when the tube is small. In addition, there is also the inconvenience of having to process the solder rod (4) to a size that matches the pipe body to be joined. Therefore, these problems have been an obstacle to automating soldering of pipes.

[Purpose of the invention]

The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a joining method that does not require replenishment of solder using a solder rod.

[Summary of the invention]

Soldering of the mating parts of a pair of tubes, where the end of one tube is fitted into the end of the other tube, is done when the end of one tube is fitted into the other tube. was immersed in a molten solder bath at least twice to form a solder coating film having a thick flange-like part, and this solder coating film was used to join the pair of tube bodies by soldering. It is something.

[Embodiments of the invention]

Hereinafter, the present invention will be described in detail based on examples with reference to the drawings.

FIG. 3 shows a solder coating device used in one embodiment of the bonding method of the present invention. The solder bath (5) is designed to melt the solder (power) by an electric heater (6). An ultrasonic horn (8) that generates ultrasonic waves is installed adjacent to this solder bath (5). A diaphragm (9) is attached to this ultrasonic horn (8).

The tip of the diaphragm (9) extends into the solder bath (5) and is designed to propagate ultrasonic vibrations to the molten solder (7). On the other hand, a fixing plate α0) is provided above the solder bath (5). A pneumatic cylinder (11) is mounted on this fixed plate QO). The piston rod of this pneumatic cylinder aυ (one is the solder bath (
5), it moves forward and backward in the directions of arrows (13a) and (13b). A tubular holder αa is screwed onto the tip of the width of the piston rod. This holder I
is for holding the pipe body (15) to be joined in a detachable manner. Then, one end of this holder I is closed, and the other end is connected to a compressed air source (not shown) through a flexible guide tube, and the tube ( The compressed air is guided through the pipe body U.
! At symmetrical positions across i1, a pair of cooling nozzles (17), (17) have their open ends connected to the tube body (
X5).

These cooling nozzles (17) and αη are connected to a cooling air source (not shown).

Next, the bonding method of this embodiment using the solder coating apparatus having the above configuration will be described. First, drive the pneumatic cylinder qυ to move the piston rod (12) in the direction of the arrow (13).
b) direction and stopped at the holding body (IJ'cl limit position).Thus, the tubular body α9 made of, for example, aluminum is fitted and held in the holding body 0.

Then, compressed air is guided from the compressed air source to the pipe body 9 through the guide pipe (16) and the holder I, and high pressure air is blown out from the opening of this pipe body. Next, the piston rod (one rod) is lowered in the direction of the arrow (13a), and the joint end of the tube body α is heated to a temperature of 400 to 420° C. in the molten solder bath (5).
solder (force immersion) and ultrasonic horn (8)
is activated, and the ultrasonic vibration is propagated to the molten solder (force) through the diaphragm (9).Then, the oxide film on the outer peripheral surface of the joint end of the tube body CIQ peels off, and the molten solder (
The solder (7) comes into close contact with the newly oxidized surface of the tube (05), and the solder (7) comes into close contact with the tube (1).At this time, high pressure air is blown out from the opening of the tube. There is no solder (no force is applied inside the tube 151, and the opening of the tube 05) is not blocked.After 2 to 3 seconds, the iston rod 0 is removed. Cooling air is blown to cool the tube body (lω to 200'O or less. As a result, a primary solder coating film edge with a uniform thickness is formed at the joint end of the tube body 5). (See Figure 4).The amount of solder in this next solder coating α barrel is insufficient for bonding. Therefore, while blowing out compressed air from the open end of the tube Q51, melt the molten solder. (Immerse in the force for 0.5-3 seconds.

At this time, the ultrasonic horn (8) is not activated. Then, most of the second coating film is melted.

However, the axis of the primary coating film near the solder surface did not melt completely due to the influence of the outside air, and on the contrary, small slivers of solder were added, resulting in a blob-like accumulation of solder. Then, in the same way as the second solder coating film, when the tube (1) is pulled up and cooled, the fifth
A secondary solder coating film as shown in the figure is formed. This secondary solder coating film has a uniform thickness for the most part, but the part opposite to the opening of the tube a9 has a flange-like part (19a). And the flange-shaped part (19a) is the same as the solder rod (4),
It serves as a source of solder for bonding. However, the tube body (1
The joint end of step 5) is fitted into a tube body made of copper or the like. Next, the joint between the two is heated to a temperature higher than the solder melting temperature using, for example, a gas burner, and
Ultrasonic vibrations are applied by an ultrasonic horn (not shown). Then, the molten solder in the brim-shaped portion (i9a) enters the small gap between the tube body (F21) by capillary action, and the gap is filled with the molten solder. When 1 and the tube body (2) are cooled to room temperature, they are completely soldered and joined together.In this way, according to the joining method of this embodiment, the soldering of a pair of tube bodies is as easy as when joining. Since the solder necessary for bonding can be supplied without wrapping the solder rod, it is extremely efficient and suitable for automation.Furthermore, compressed air can be jetted out from the tube during solder coating. yoυ
Since the tube opening is prevented from being blocked, the step of attaching and removing the sealing material to the tube opening can be omitted.

In the above embodiment, the opening end of the tube body is prevented from being blocked by blowing out compressed air. If the other end is closed, the air remaining inside expands, and the expansion of this air may be used to prevent the open end from being blocked. Further, in the above embodiments, bonding between dissimilar metals such as aluminum and copper is exemplified, but it goes without saying that the present invention can also be applied to bonding between similar metals. Furthermore, if the amount of solder in the solder coating layer is small, the number of times the tube is dipped into the molten solder is not limited to two times, but may be increased as appropriate. Further, in the above embodiment, ultrasonic waves are applied during soldering, but soldering may be performed using flux without being limited to this.

Furthermore, in some cases, cooling nozzles (l'v, α7
) may be omitted and cooling may be performed by natural air cooling.

〔Effect of the invention〕

The present invention provides a method for soldering a fitting portion of a pair of tubes, in which an end of one tube is fitted to an end of the other tube, when one tube is fitted into the other tube. The end of the body is immersed in a molten solder bath at least twice to form a solder coating film with a thick flange-like part. This eliminates the inconvenience of winding the solder nearby and supplying the solder one by one.

As a result, we believe that welding performance has improved and welding work is highly suitable for automation.

[Brief explanation of drawings]

1 and 2 are cross-sectional views of the main parts for explaining conventional solder joints, and FIG. 4 and 5 are sectional views of essential parts showing a solder coating film formed in a bonding method according to an embodiment of the present invention. (5): Solder bath, (8): Ultrasonic horn. (L51 = Tube (one side). α81 primary solder coating film. (11: Secondary soldering film, (201: Tube (
the other).

Claims (3)

[Claims] (1) In a joining method in which the end of one of a pair of tubes is fitted to the end of the other tube and the fitted portions are joined by soldering, the end of the one tube is immersing the tube in a molten solder bath and then pulling it up to deposit a primary solder coating film on the outer peripheral surface of the end of the one tube;
The end of the above-mentioned one tube on which the above-mentioned -next solder coating film has been applied is immersed again in the above-mentioned molten solder bath, and then pulled up to the side opposite to the opening side of the above-mentioned one of the above-mentioned pipe bodies with the above-mentioned -next solder coating film applied. forming a secondary solder coating film having a brim-like thick portion on the secondary solder coating film; A joining method comprising the steps of: fitting the pair of tube bodies together, and then heating and joining the pair of tube bodies by soldering. (2) - To form the next solder coating film -X
2. The joining method according to claim 1, wherein ultrasonic vibrations are applied to said one tube while the tube is immersed in a molten solder bath. (3)-While one tube is immersed in a molten solder bath to form the next solder coating film and the second solder coating film, gas is blown out from the open end of the one tube. The joining method according to claim 1 or 2, characterized in that the opening end is prevented from being blocked.