JPH01127183A - Manufacture of hose connector - Google Patents

Abstract

PURPOSE:To improve the product quality and to reduce the manufacturing cost by arranging fittings for connecting with the same material to Al or Al alloy piping with specific wall thickness to perform fillet electron beam welding via a reinforcement member of weld or a prescribed gap. CONSTITUTION:The fittings 2 for connecting with the same material are set to the Al or Al alloy piping 1 with the wall thickness of 0.5-2.5mm and an O ring 4 made of Al or Al alloy material is arranged thereto as the reinforcement member of weld. The fillet electron beam welding is performed on the O ring 4 from the electron beam direction 6. At this time, reinforcement 12 of weld is formed on a weld zone. Or the gap 3 is formed between the piping 1 and the fittings 2 and weld metal 9 is formed by the fillet electron beam welding. By this method, the product quality such as strength and corrosion resistance of the title product hose connector 10 is improved. Since equipment is simplified and the need of the stress relief stage is eliminated, the manufacturing cost is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for manufacturing a hose cap, and particularly to a method for manufacturing a hose cap comprising a thin-walled pipe and a connecting fitting.

[Prior Art] (Background Art) As shown in Fig. 6, air conditioner parts (
For example, the evaporator 61, condenser 62, compressor 63, receiver dryer, expansion valve 64), brake, clutch, etc., may be connected to each other or these parts and other appropriate parts.
As shown in the figure, a pipe 1 (
The distal end of the pipe l having the connecting fitting 2 at its distal end is connected via a hose cap lO.

By the way, in the recent automobile industry, contradictory conditions such as pursuing high quality and cost reduction are required at the same time, and the need for reducing vehicle weight is increasing to improve fuel efficiency.
Even small parts such as bolts, nuts, and bottles are being made of lightweight materials such as aluminum or aluminum alloys, and a similar trend has also been seen with hose fittings, which have partially been put into practical use. This demand for weight reduction also extends to piping, and there is a demand for thinner piping.

(Prior art) However, the two methods of joining the connecting fittings and piping are as follows:
Conventionally, bonding methods using adhesives, brazing, and TIG welding are known.

[Problems to be solved by the invention] However, bonding methods using adhesives have poor heat resistance, adhesive strength,
Currently, it has not been put into practical use because it lacks reliability in terms of repeated bending strength, vibration strength, etc.

Furthermore, the joining method by brazing has the following problems. In other words, ■ pitting corrosion occurs due to the residual flux for removing oxide film mainly composed of chlorides and fluorides (corrosion resistance is not good); ■ chemical conversion treatment and pollution countermeasures are required in the de-fluxing process. To do so.

■If you try to prevent the progression of pitting corrosion due to residual flux, surface treatment and drainage equipment are required. ■After joining, the strength of the hose cap becomes a soft material, and the strength of the caulking between the nylon or rubber hose, etc. In order to improve the strength of the bolts and connecting fittings, re-quenching treatment and the accompanying strain relief process are necessary; ■When joining, the clearance between the piping and the connecting fittings must be tightly controlled; 1. Normally 0. If the thickness is not 5 mm or less, brazing is likely to cause defects, so high precision is required, which in turn reduces workability. ■ If the pipe is made thinner, the difference in mass between the pipe and the connecting fitting will increase, making it difficult to braze. These problems include sometimes melting the pipes and causing a burning phenomenon in the connecting fittings.

On the other hand, the joining method using TIG welding has the following problems.

■In order to improve corrosion resistance and strength, MH, Zn
, When using aluminum alloys containing Cu, etc., micro-cracking is likely to occur due to welding (resulting in decreased strength and leakage). ■ When pipes are made thinner, the difference in mass between the pipes and the connecting fittings becomes larger, and the pipes may be damaged during welding. (This undercut causes fatigue cracks due to the notch effect, which in turn deteriorates the pressure resistance and airtightness of the hose fitting.) Also, the piping is likely to melt.
■Welding thin-walled pipes requires advanced welding technology.

■As in the case of brazing, the hose cap becomes a soft material after joining, so re-quenching and the associated strain relief process are required.

[Means for solving the problem] The first gist of the present invention is to provide a thin-walled pipe made of aluminum or aluminum alloy with a wall thickness of 0.5 to 2.5 mm, and a connecting fitting made of aluminum or aluminum alloy. A method of manufacturing a hose cap is characterized in that a member made of aluminum or an aluminum alloy and serving as a reinforcement is disposed near the fillet portion, and fillet welding is performed by electron beam welding.

The second aspect of the present invention is to connect a thin-walled pipe made of aluminum or aluminum alloy with a wall thickness of 0.5 to 2.5 mm and a Pa connection fitting made of aluminum or aluminum alloy, with a clearance between the two of 1.5 mm. A method of manufacturing a hose cap is characterized in that fillet welding is performed by electron beam welding to a thickness of 0 mm or less.

[Effect] The structure of the present invention will be explained below along with its operation.

The inventor of the present invention made extensive efforts to solve the problems of conventional joining methods, and found that the joining method was not TIG welding or brazing, but electron beam welding (hereinafter referred to as E, B, W). (sometimes abbreviated as ), pitting corrosion does not occur in the welded part or the base metal, and corrosion resistance from this aspect can be improved. Furthermore, in combination with the thin wall of the piping, Electron beam welding was adopted as the joining method because the grain boundaries of the welded part are healthy, no microcracks occur, and no decrease in strength or leakage occurs.

However, it has been found that simply welding the pipe and the connecting fitting using electron beam welding causes another problem. In other words, an undercut occurs, and this undercut causes a decrease in fatigue strength, which in turn impairs airtightness.

Therefore, we conducted further research and experiments to find out how to avoid this phenomenon.

If electron beam welding is performed with a member that will serve as a backfill placed near the fillet area, it is possible to prevent undercuts from occurring, and furthermore, the backfill after welding can also help improve strength. I understand (this effect is called the overflow effect).

In addition, as for the arrangement of the member serving as the reinforcement, for example, an O-ring may be provided, or a flange may be formed on the connecting fitting.The dimensions thereof are 0.5 to 10 m
If the width and height exceed the lower limit of the above range, the reinforcement effect will be small, and if the upper limit is exceeded, the melting time during welding will become longer, which is not preferable.

As another method, it was found that if the clearance between the pipe and the connecting fitting was set to 1.0 mm or less, undercarriage/) would not occur.

Here, if the clearance exceeds 1.0 mm, the fifth
As shown in the figure, an undercut occurs, which reduces the pressure resistance and strength of the hose fitting, so 1.
It shall be 0 mm or less.

[Example] The present invention will be explained in more detail below using examples.

(Embodiment of the first invention) (First embodiment) An O-ring made of An and A1 alloy was used as the first O-ring for the aluminum alloy according to the combinations shown in Table 1 for the connection fittings and piping.
They were arranged as shown in Figure (a) and welded by electron beam welding.

In addition, the piping used was a piping with a wall thickness of 1.0 mm, and the O-ring used was an O-ring with a width of 1.5 mm and a height of 1.5 mm.

The state of the welded part after welding is shown in Figure 2 (L).

As can be seen from FIG. 2(a), the welding width of the welded portion 9 was extremely narrow. Further, there was a surplus of 12, and no undercut occurred.

The following various tests were conducted on the hose caps manufactured in this manner.

Bonding Strength Test> A tensile test was conducted in the axial direction from the shape shown in FIG. For comparison, piping and connection fittings made of the aluminum alloy combinations shown in Table 1 were TIG welded and brazed (
prior art).

The results are shown in Table 1.

As shown in Table 1, this example exhibited almost the same tensile strength as the conventional example in which re-hardening was performed, even without re-hardening. Since 3003 is a non-heat-treated alloy, the joint strength does not change even after re-hardening, so no tests were conducted, but in the as-welded state, this example showed higher tensile strength than the conventional example.

Corrosion Resistance Test> A corrosion resistance test was conducted under the following conditions for this example and the conventional example.

■Test piece shape It is shown in Figure 3.

■Test liquid 5%NaOH+0.05%H2304 ■Cycle conditions Repetition of the next condition ・Soak for 2 minutes ff1 (room temperature) ・Dry for 120 minutes (50℃) ■Number of cycles 400 cycles ■Tester Suga tester, DW-UD-2 type The above test results are shown in Table 2.

As can be seen from Table 2, the pitting depth of the hose cap manufactured by the method of the present invention is approximately half that of the TIG welding method for both the connection fittings and piping, and the depth of the pitting corrosion for the hose fittings manufactured by the method of the present invention is approximately half that of the TIG welding method, and that for the connection fittings and piping of the hose fittings manufactured by the brazing method, compared to the TIG welding method. It is about 1/4th of the total cost for the pipes, and 1/6th for the piping, which is extremely good. Note that the values in Table 2 are the average pitting depths of 10 pittings.

Airtightness Test> Next, an airtightness test was conducted on the hose cap shown in FIG. The test conditions are as follows.

・Airtightness test conditions ■Pressure crab 30kg/cm2 ■Medium 2N2 gas ■Temperature: Room temperature (20℃) ■Pressure holding time: 5 minutes When the number of defects after the test (leak defect at n = 200) was investigated, In this example, no defects occurred at all.

Pressure test> Further, a pressure resistance test was conducted on the test piece shown in FIG.

The test conditions are as follows.

・Pressure test conditions ■Pressure crab 45 kg / cm 2 ■Medium: Water ■Temperature: Room temperature (20℃) ■Pressure holding time: 5 minutes Check the number of defects (burst defects at n = 200) after the test However, no defects were observed in this example.

(Second Embodiment) In this example, instead of the O-ring in the first embodiment, a width of 1. o
A collar portion with a height of 1.0 mm was formed on the connecting fitting.

Other points are similar to the first embodiment.

In addition, when various tumor tests were conducted in the same manner as in the first example,
In each test, the same results as in the first example were obtained.

(Embodiment of the second invention) (Third embodiment) In this embodiment, the O-ring shown in the first embodiment or the collar part shown in the second embodiment is not provided, but instead the clearance is set to 0. Electron beam welding was performed with a setting of 7 mm.

As a result, a welded portion shown in FIG. 2(b) was obtained. Second
As shown in Figure (b), the width of the melt-in part was extremely narrow.

When the hose cap thus manufactured was subjected to a joint strength test and a corrosion resistance test in the same manner as in the first example, good results were obtained as in the first example. .

Airtightness Test, Pressure Resistance Test> In this example, an airtightness test and a pressure resistance test were conducted while varying the clearance, and the relationship between the clearance and the number of defects was investigated. The results are shown in FIG.

As shown in FIG. 4, in the conventional example, the clearance is 0.
The number of defects could not be reduced to O unless the thickness was set to 4 to 0.5 mm, but with electron beam welding, the defect number was 1.0 mm.
By setting the number of defects to m or less, it was possible to reduce the number of defects to 0 even in a pressure resistance test. In addition, the airtightness test was 1.3m.
By setting it to m or less, the number of defects could be reduced to 0.

The results of the above examples are summarized in Table 3. As shown in Table 3, it can be seen that the method of the present invention is extremely superior overall.

[Effects of the Invention] According to the invention of the present application, the following various effects can be obtained.

■Hose fittings with high reliability in terms of bonding strength, bending strength, vibration strength, etc. can be obtained.

■Hose fittings with very little pitting corrosion and good corrosion resistance can be obtained.

■No need for chemical conversion treatment or anti-pollution measures in the defluxing process.

■No surface treatment or drainage equipment required.

■The caulking strength of the nylon or rubber hose, etc. and the cap is sufficient, eliminating the need for re-quenching treatment and the associated strain relief process.

■Compared to conventional methods, it is easier to manage the clearance between piping and connecting fittings when joining.

■It is possible to make the pipes thinner.

(2) Even if an aluminum alloy containing Mg, Zn, Cu, etc. is used, no micro-cracking occurs, and therefore a good hose cap with high strength and no leakage can be obtained.

- Even if the piping is made thinner, undercuts do not occur; therefore, thin-walled piping can be used (thus, the weight of the hose cap can be reduced), and a hose cap with excellent fatigue strength can be obtained.

■Advanced welding techniques are not required, so workability is improved.

Compared to 6φTIG welding or normal E, B, and W, 0 can change greatly.

The piping of ω3003 in Table 1 is a non-heat-treated alloy, so even if it undergoes a re-quenching process, it will not change its strength after joining, so no tests were conducted.Table 2: O: Very good, O: Average, Δ: Poor

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view of a hose cap according to an embodiment of the present invention. FIG. 2 is a conceptual diagram showing a welded portion of a hose cap according to a conventional example and an embodiment of the present invention. FIG. 3 is a partial sectional view of the hose cap to show the shape of the test piece. Efg4
The figure is a graph showing the relationship between the clearance and the number of defects in airtightness tests and pressure tests. FIG. 5 is a sectional view of a conventional hose cap showing a state in which the hose cap is welded. FIG. 6 is a conceptual diagram showing the air conditioner system showing the parts where the hose fittings are used. 1... Piping, 2... Connection fittings, 3... Joint (
straight groove), 3C...clearance, 3F...
Clearance (with 7 langes), 4-...O-ring, 5-
...For tightening the metal fittings, bolt hole, 6...electron beam direction, 6...flange, 8...packet, 9...welding full bend, lO...hose cap, 12... I, 61-・
- Evaporator, 62... Capacitor, 63... Compressor, 64... Expansion pulp. θ... Beam irradiation angle, D... Piping outer diameter, d...
Piping inner diameter/Figure 2 (a-) (b) (n=200)

Claims (5)

[Claims] (1) Thin-walled piping made of aluminum or aluminum alloy with a wall thickness of 0.5 to 2.5 mm and connecting fittings made of aluminum or aluminum alloy, and a member made of aluminum or aluminum alloy that will serve as a backing. A method for manufacturing a hose cap, characterized in that the hose cap is disposed near the fillet portion, and fillet welding is performed by electron beam welding. (2) The method for manufacturing a hose cap according to claim 1, wherein the member serving as the extra layer is an O-ring. (3) The method for manufacturing a hose cap according to claim 2, wherein the member serving as the extra layer is a flange portion formed on the connection fitting. (4) The method for manufacturing a hose cap according to any one of claims 1 to 3, wherein the member serving as the overfill has a width of 0.5 to 10 mm and a height of 0.5 to 10 mm. . (5) A thin-walled pipe made of aluminum or aluminum alloy with a wall thickness of 0.5 to 2.5 mm and a connecting fitting made of aluminum or aluminum alloy are joined by electron beam welding with a clearance of 1.0 mm or less between the two. A method for manufacturing a hose cap, characterized by performing fillet welding.