JPH10121215A - Production of scroll made of aluminum alloy - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a scroll having excellent durability (fatugue strength) by cooling the cast scroll made of Al alloy after a producing process high in temp. and then subjecting it to aging treatment. SOLUTION: The Al alloy is subjected to die casting or molten metal casting to mold into the shape of a scroll. Next, the Al alloy is cooled from the high temp. producing state and is subjected to aging treatment. Or, the Al alloy is cooled from the high temp. state, thereafter, its temp. is raised and hold to a solution treating temp., and is quenched at >=90 deg.C to be subjected to aging treatment. As the Al alloy, an Al-Si alloy contg. 8 to 13% Si as the main alloy components, particularly, an Al-Si-Cu alloy contg. 1 to 4% Cu and 0.5 to 1.5% Mg in addition to Si is preferably used. In the Al-Si alloy, it is possible that, after casting, the alloy is air-cooled to an ordinary temp. and is then subjected to aging treatment, but, after the casting, it is quenched into hot water of >=70 deg.C from the high temp. state of >=500 deg.C and is the subjected to aging treatment, by which its fatigue resistance can further be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a scroll (scroll) of a scroll compressor used for a car cooler, an air conditioner, and the like.

[0002]

2. Description of the Related Art Various types of compressors (compressors) such as car coolers and air conditioners have been used. In recent years, small-sized compressors have been used in view of weight reduction, energy saving, high performance and low noise. Scroll compressors have become widespread. Scrolls (scrolls) of scroll type compressors are generally manufactured by die-casting aluminum alloy, squeeze casting, die-casting or hot-forging an extruded rod. By quenching in warm water until aging treatment, characteristics required for compressor scrolls such as fatigue strength are given.

[0003] In recent years, the use of scroll compressors has increased due to the increase in vehicles equipped with auto air conditioners, and the use of alternative refrigerants in accordance with Freon regulations has led to higher compression. And high reliability is required.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been developed in order to provide a scroll of a scroll type compressor with more excellent characteristics, in particular, with regard to the relationship between the combination of the manufacturing method and the heat treatment and the fatigue strength. The purpose of the present invention is to provide a method of manufacturing an aluminum alloy scroll having more excellent durability (fatigue strength) than the conventional one.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, a method of manufacturing an aluminum alloy scroll according to the present invention is to form an aluminum alloy scroll manufactured by die casting or molten forging from a high-temperature manufacturing process. The first characteristic is that the aging treatment is performed after cooling, and the second characteristic is that the temperature is raised to and maintained at the solution treatment temperature after cooling, and the aging treatment is performed by quenching to a temperature of 90 ° C. or more. .
A third feature is that the aluminum alloy contains 8 to 13% of Si as a main alloy component.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, an aluminum alloy is formed into a scroll shape by die casting or molten forging, cooled from a high-temperature production state, and then subjected to an aging treatment. After cooling from a high-temperature production state, the temperature can be raised to and maintained at the solution treatment temperature, quenched to a temperature of 90 ° C. or higher, and subjected to aging treatment. As an aluminum alloy,
Si: Al-Si containing 8 to 13% as a main alloy component
System alloy, especially Si: Cu: 1-4%, Mg: 0.5-1.
Al-Si-C containing 5%, the balance being Al and impurities
A u-based alloy is preferred.

[0007] Al-Si alloys may be air-cooled to room temperature and then subjected to aging treatment after die casting or molten forging. However, after casting, the alloy is quenched from a high temperature of 500 ° C or more to a hot water of 70 ° C or more. The aging treatment further improves the fatigue resistance characteristics. The aging treatment is preferably performed at 170 to 220 ° C. for about 2 to 6 hours.

[0008] After cooling the Al-Si alloy by die casting or molten forging, the temperature is raised to a solution treatment temperature and maintained.
When aging by quenching to a temperature of 90 ° C or higher, solution treatment is performed at a temperature of 500 to 530 ° C for 4 to 6 hours, and aging is performed.
It is preferably carried out at a temperature of 160 to 180 ° C. for more than 8 hours.
The quenching temperature is desirably 90 to 120 ° C. When quenched at a temperature of 90 ° C or higher, more excellent fatigue strength can be obtained than when quenched at a temperature of less than 90 ° C. 120
When the quenching treatment is performed at a temperature exceeding ℃, it is difficult to obtain sufficient fatigue resistance, water cannot be used for the quenching solution, temperature control becomes more difficult, and the cost increases. In this case, it is desirable that the internal structure of the obtained scroll is a spherical Si particle.

[0009]

Hereinafter, examples of the present invention will be described in comparison with comparative examples. Example 1 A scroll (capacity 90 cc) for a car air conditioner was replaced with Al-S
i-based alloy (Al-10% Si-3% Cu-1% Mg, JIS
(Equivalent to AC8C alloy). The scroll was air-cooled from a high temperature in a production state to a normal temperature and subjected to an aging treatment at a temperature of 175 ° C. for 8 hours to obtain a T5 refined scroll.

Example 2 The same scroll as in Example 1 was used for an Al-Si alloy (Al
(-10% Si-3% Cu-1% Mg, JIS AC8C alloy equivalent)
Was manufactured by forging molten metal under the same conditions as in Example 1. After the production, it was cooled to room temperature, solution-treated at 510 ° C. for 4 hours, quenched in warm water at 90 ° C., and then aged at 175 ° C. for 8 hours to obtain a T6 refined scroll.

Comparative Example 1 The same scroll as in Example 1 was used in Examples 1 and 2.
The same Al-Si alloy was manufactured by forging molten metal under the same conditions as in Examples 1 and 2. After production,
It was cooled to room temperature, solution-treated at 510 ° C. for 4 hours, quenched in hot water at 70 ° C., and then aged at 175 ° C. for 8 hours to obtain a T6 refined scroll.

When the scroll compressor is operated for a long time,
The breaking of the scroll occurs on the fixed side of the scroll, and is likely to occur at the base of the spiral at the center of the scroll (the discharge hole side) where high pressure is applied. In consideration of this, in order to easily evaluate the durability of the scroll, a cantilever bending fatigue test was performed under the following conditions.

Fatigue test conditions Test equipment: hydraulic servo type fatigue tester Test temperature: normal temperature Repetition rate: 1800 cpm Stress ratio: R = 0.1

Further, in order to evaluate the properties of the material, the scrolls obtained in the examples and comparative examples were 100 mm long,
A flat plate having a width of 50 mm and a thickness of 2.0 mm was cut out and subjected to a plate bending fatigue test according to the following conditions.

Flat plate bending fatigue test conditions Test equipment: Schenk type flat plate bending fatigue tester Test temperature: normal temperature Repetition rate: 3600 cpm Stress ratio: R = -1

The results of the cantilever bending fatigue test and the plate bending fatigue test of the T5 tempered scroll of the present invention obtained in Example 1 and the conventional T6 tempered scroll obtained in Comparative Example 1 are shown. Are shown in FIGS. 1 and 2, respectively.

As shown in FIGS. 1 and 2, in both the cantilever bending fatigue test and the plate bending fatigue test,
The fatigue strength of the T6 material of Comparative Example 1 is high on the high load (high stress) side where the number of fracture repetitions is up to about 2 × 10 ^6, but the fatigue strength of the T5 material of Example 1 decreases when the number of fracture repetitions exceeds that. When the number of repeated fractures is 2 × 10 ⁷ , a considerable difference occurs.

The results of the cantilever bending fatigue test of the T6 tempered scroll of the present invention obtained in Example 2 and the conventional T6 tempered scroll obtained in Comparative Example 1 are compared with each other. As shown in FIG. As shown in FIG.
The 90 ° C. hardened material according to the present invention is the same as the conventional 70 ° C.
Compared to the quenched material, the fatigue strength is higher over the entire range from the low cycle side to the high cycle side, and the number of repeated fractures is 1 ×
Of 10 ⁷ definitive fatigue strength is excellent about 17% compared to 70 ° C. quenching material 90 ° C. quenching material.

[0019]

As described above, according to the present invention, it is possible to obtain an aluminum alloy scroll having significantly improved durability (fatigue strength) as compared with a conventional aluminum alloy scroll. It is effective to use for a compressor (compressor).

[Brief description of the drawings]

FIG. 1 is an LN diagram showing the results of a cantilever bending fatigue test of a material of the present invention in comparison with a comparative material.

FIG. 2 is an SN diagram showing the results of a plate bending fatigue test of the material of the present invention in comparison with a comparative material.

FIG. 3 is an LN diagram showing results of a cantilever bending fatigue test of the material of the present invention in comparison with a comparative material.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // C22F 1/00 611 C22F 1/00 611 691 691B

Claims (3)

[Claims] 1. A method for manufacturing an aluminum alloy scroll, comprising cooling an aluminum alloy scroll manufactured by die casting or molten forging from a high-temperature manufacturing process and then aging. 2. After cooling, the temperature is raised to a solution treatment temperature.
The method for producing an aluminum scroll according to claim 1, wherein the aluminum scroll is held and quenched to a temperature of 90 ° C or higher to perform aging treatment. 3. An aluminum alloy containing, as a main alloy component, Si: 8 to 13% (% by weight, the same applies hereinafter).
3. The method for producing an aluminum alloy scroll according to claim 1, wherein the scroll is a Si alloy.