JPH02197506A - Production of scroll vane - Google Patents

Abstract

PURPOSE:To reduce a loss in driving of a scroll vane and to improve the durability and reliability of the vane by forming a layer contg. a solid lubricant dispersed and embedded in Al on the top of the lap of the vane when the body of the vane is formed. CONSTITUTION:A solid lubricant is dispersed in an Al-based material to prepare a powdery mixture. This mixture and an Al-based material for forming the body of a scroll vane 5 are simultaneously molded by powder metallurgical processing to form the body of the vane 5 and a layer 8 contg. the dispersed solid lubricant on the top of the lap 7 of the vane. Spiral laps 16b, 17b are perpendicularly formed on the opposite surfaces of a pair of end plates 16a, 17a. Gas is compressed or expanded by engaging the laps 16b, 17b.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a method for manufacturing a scroll blade used in a scroll fluid machine such as a scroll compressor.

(Prior art) A scroll compressor has a structure in which a fixed side scroll blade and an orbiting side scroll blade are meshed with each other, each having a spiral wrap formed on a pair of end plates.The orbiting scroll blade is rotated so that both wraps are in contact with each other. By doing so, the compression chamber formed by both scroll blades gradually decreases toward the center, compressing the fluid sucked in from the outer periphery of both wraps, and discharging compressed gas from the discharge port in the center. be.

Conventionally, the combinations of materials for the fixed scroll blades and orbiting scroll blades that make up the compression mechanism of this type of scroll compressor include: ■ Iron-based materials, mainly cast iron, were used for both the fixed scroll blades and the orbiting scroll blades. (2) Types in which iron-based materials are used for the fixed scroll blades and aluminum-based materials are used for the orbiting scroll blades are known.

However, the combination of these materials has the following drawbacks.

In the case of the combination of materials listed in ■ above, (a) If iron-based materials with high specific gravity are used for the orbiting scroll blades, the centrifugal force during operation will increase, resulting in increased bearing load and sliding loss. There were other problems. In particular, during high-speed operation, the centrifugal force becomes extremely large, resulting in severe wear between the main shaft and bearings as well as between sliding surfaces, which tends to cause seizing phenomena and significantly reduce reliability and durability. Resulting in. Furthermore, there is a problem in that compressed gas leaks due to wear between the sliding surfaces of both scroll blades, resulting in a significant reduction in compression performance.

(b) In order to improve the precision of scroll blades, it is necessary to precisely machine the mounting surfaces and sliding surfaces, but iron-based materials have low machinability, making machining difficult and reducing productivity. There was a problem of low

In the case of the above material combination (2), (c) the aluminum-based material and the iron-based material have significantly different coefficients of thermal expansion, so the clearance between both scrolls had to be increased, leading to a decrease in performance.

(d) Similar to (b) above, precision machining is extremely difficult due to the low machinability of iron-based materials.

In addition to compensating for the shortcomings of these iron-based materials, in order to meet the recent demands for smaller, lighter, and faster scroll compressors of this type, both fixed scroll blades and orbiting scroll blades are made of aluminum-based materials. A method using the is currently being developed.

(Problems to be Solved by the Invention) The above-mentioned fixed scroll blades and orbiting scroll blades using aluminum materials have excellent workability and are lightweight, so they are not suitable for steady sliding. Although it has the advantage of exhibiting good sliding properties and wear resistance, it also has the advantage that when the lubricating oil on the sliding surface runs out due to extreme pressure being applied or due to dilution of the lubricating oil by refrigerant, for example, When aluminum-based materials are used, adhesive wear tends to occur between the sliding surfaces, resulting in low reliability.

Therefore, in order to compensate for the drawbacks caused by aluminum-based materials, a thin film formation method such as vapor deposition or sputtering is used to apply a solid lubricant such as carbon-based or molybdenum-based lubricant to the sliding surface, that is, the top surface of the lap of both scroll blades. Attempts have been made to form a film using However, the solid lubricant layer formed by the thin film method lacks durability and has problems such as peeling off easily, and a separate process for forming the solid lubricant layer must be performed after forming the scroll blades. Therefore, there was also a problem that manufacturing costs increased.

The present invention has been made in order to address the problems of the prior art described above, and is a solid material for suppressing adhesive wear of scroll blades using an aluminum-based material that is excellent in machining and can suppress the effects of centrifugal force. It is an object of the present invention to provide a method for manufacturing a scroll blade that facilitates the formation of a lubricant layer and improves its durability.

[Structure of the Invention] (Means for Solving the Problems) That is, the method for manufacturing a scroll blade of the present invention involves forming spiral wraps upright on opposing plate surfaces of a pair of mirror plates, and interlocking these wraps. In manufacturing a scroll blade that compresses or expands gas, a mixed powder in which a solid lubricant is dispersed in an aluminum-based material that forms the vicinity of the top of the wrap, and an aluminum-based material that forms the scroll blade body. The present invention is characterized in that a dispersed layer of the solid lubricant is simultaneously molded in the vicinity of the top of the wrap integrally with the scroll blade body by a powder metallurgy method.

(Function) In the method for manufacturing a scroll blade of the present invention, a solid lubricant dispersion layer in which a solid lubricant is dispersed and embedded in aluminum is formed near the top of the wrap at the same time as the scroll blade main body is formed. In the process, a scroll blade having a solid lubricant dispersion layer integrally formed therein is obtained.

Furthermore, the obtained solid lubricant dispersion layer has excellent durability because it is firmly bonded to the base material aluminum. Therefore, it is possible to sufficiently and stably exhibit the characteristics of the aluminum-based material, such as the ability to suppress the friction of sliding parts during high-speed operation due to the small centrifugal force.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing a manufacturing process using a powder metallurgy method in which the present invention is applied to manufacturing a scroll blade for use in a scroll compressor. In the figure, reference numeral 1 denotes a mold for forming a scroll blade, which forms a spiral groove 1b, which becomes a wrap forming part, at the bottom of a cavity 1a, which becomes an end plate part of the scroll blade.

First, in the groove 1b of the scroll blade forming mold 1, a carbon-mixed aluminum powder 2 made by mixing 3% by volume of carbon (graphite), which is a solid lubricant, with 12% by weight S1-containing aluminum powder produced by an air atomization method is placed. Fill it by a predetermined amount using a vibration method or the like (Fig. 1-A).

Next, the groove 1 filled with carbon-mixed aluminum powder 2 is
The aluminum powder 3 containing 12% by weight of S1 is filled into the cavity 1a and the aluminum powder 3 (FIG. 1-B).

After this, the filled carbon-mixed aluminum powder 2 and the 12 wt% S1-containing aluminum powder 3 are subjected to pressure molding conditions (for example, 400°C, 200 kg/c+/ ) that enable processing in the superplastic processing region. At the same time, pressure is applied with the bunch 4 to form the scroll blade into the desired scroll blade shape (Fig. 1-○), and then the sliding surface is cut to increase the precision to form the scroll m5 into the desired shape.
get. The resulting scroll TA5 has a spiral wrap 7 formed upright on one surface of the end plate 6, and a solid lubricant dispersion layer 8 integrally formed near the top of the wrap 7. (Figure 1-D).

In this way, by using powder mixed with carbon as a solid lubricant in the aluminum powder that forms the area near the top of the wrap, and by forming the scroll blades using powder metallurgy at the same time as the end plate, the solid lubricant is dispersed in the area near the top of the wrap. The layer can be formed simultaneously with the scroll blade body, and the resulting solid lubricant layer is formed integrally with the scroll blade body. Also,
Since the aluminum-based material produced by powder metallurgy is used, the resulting scroll blade is formed into a near net shave, and is also highly free-cutting, making it easy to machine the sliding surfaces and the like.

According to the above molding method, a pair of scroll blades for use in a scroll compressor is obtained by molding, for example, according to the respective shapes of the fixed scroll blade and the orbiting scroll blade.

Here, in this example, as the scroll blade forming material,
Although an aluminum material containing 121 ffm% of Sl was used, since the required mechanical strength varies depending on the conditions, an appropriate aluminum material may be selected as appropriate. In addition, solid lubricant materials are not limited to carbon, but MoS2
, ON, SIN, SIC, etc. can be used.

According to the above-mentioned material structure, many hard points are formed on the surface of the scroll blade due to the St component contained in the aluminum-based material, so that the load resistance is improved. Moreover, since a dispersed layer of carbon, which is a solid lubricant, is formed on the surface of each lap of the orbiting scroll blade and the fixed scroll blade, adhesive wear due to sliding between the aluminum materials of the top of the lap and the end plate is avoided. This results in a material pm combination with a low coefficient of friction and high abrasion.

The thickness of the solid lubricant dispersion layer formed in the vicinity of the top of the wrap varies depending on the amount of solid lubricant dispersed and the conditions of use of the scroll blade itself, but it should be approximately 5 μm or more and preferably an appropriate thickness. It is 20μ or more. Also,
The amount of solid lubricant dispersed varies depending on the material used, but is preferably about 30% by volume to I5% by volume relative to the base material.

Next, examples of use of fixed scroll blades and orbiting scroll blades manufactured according to the above molding method will be described.

FIG. 2 is a sectional view showing a schematic configuration of a scroll compressor using the fixed and orbiting scroll blades. In the figure, 11 is a sealed container, and the inside thereof is a frame 1.
It is separated into two spaces communicated by 2. A cylindrical convex portion 12a is provided at the center of the frame 12, and a main shaft 13 is rotatably supported in an opening 12b within the convex portion 12a. A rotor 14 is attached to the lower part of the main shaft 13, and a stator 15 is press-fitted into the closed container 11 so as to be located on the outer periphery of the rotor 14.

The crankshaft portion 13a formed on the upper part of the main shaft 13 includes
The orbiting scroll blade 16 is supported with zero rotation, and the fixed scroll blade 1 is supported on the outer peripheral protrusion 12b of the frame 12.
7 is fixedly installed.

These orbiting scroll W16 and fixed scroll IA
17 are manufactured by the above-mentioned molding method, and have a structure in which spiral wraps 16b and 17b are provided upright on opposing plate surfaces of the end plate portions 16as and 17a, and the orbiting scroll blades 16 The wrap 16b of the fixed scroll blade 17 and the wrap 17b of the fixed scroll blade 17 are arranged so as to mesh with each other, and a compression chamber 18 is formed by these wraps 16b and 17b. Also, both wraps 16b.

A dispersion layer 19 of carbon, which is a solid lubricant, is formed near the top of the blade 17b, and this solid lubricant dispersion layer allows the mirror plate portions 16a of the opposing scroll blades 16 and 17 to be separated.
, 17a. Between the orbiting scroll blade 16 and the frame 12, there is a mechanism for preventing rotation of the orbiting scroll blade 16 during the orbiting motion, such as an Oldham ring 2.
0 is set.

A discharge port 21 for discharging compressed gas into the closed container 11 is formed in the center of the fixed scroll W17, and both wraps 16b, 17b are formed in the outer peripheral part.
A suction pipe 22 that leads gas to the compression chamber 18 formed by
is formed.

The compressed gas discharged into the closed container 11 from the discharge port 21 is led out to the outside from a discharge pipe 23 that is attached to penetrate the side of the closed container 11.

As a result of actual machine testing of the scroll compressor with the above configuration, high load (high load) operation and high speed operation (150
Good abrasion resistance and low vibration properties were obtained under conditions of (Hz).

In addition, using a wear resistance tester, a scroll blade made of a combination of aluminum-based material with the solid lubricant dispersion layer produced according to this example integrally formed on the top of the wrap, and a scroll blade made of a combination of aluminum-based material and iron-based material/iron-based material were tested. When the relationship between torque and load and friction coefficient and load was evaluated for a scroll blade (conventional example) consisting of a combination, results as shown in FIGS. 3 and 4 were obtained.

As is clear from Fig. 3, the scroll blade manufactured according to this example has a small torque value up to high loads and a very small friction coefficient, and does not cause problems such as seizure up to high loads. Do you get it. On the other hand, the scroll blade of the comparative example had a large torque value and friction coefficient from the initial stage (it was found that seizing occurred at low loads).

As described above, the scroll blade manufactured according to the manufacturing method of the present invention can reliably prevent sliding between aluminum-based materials due to the solid lubricant dispersion layer formed integrally with the main body near the top of the wrap. Compared to conventional ones using iron-based materials, the coefficient of friction can be lowered, reducing sliding loss, and the sliding surface with excellent wear resistance can be obtained with a high level of seizure. Leakage of compressed gas due to wear between the sliding surfaces of the blades can be suppressed to a small level, thereby making it possible to provide a scroll compressor with high durability and reliability. Additionally, it has superior stability in abnormal situations compared to conventional ones using aluminum-based materials, and this also results in significantly improved reliability.

Furthermore, since both scroll blades are made of aluminum material with approximately the same coefficient of thermal expansion, the coefficient of thermal expansion in the height direction of the wrap is the same, making it possible to set the clearance between both scroll blades small, allowing operation. It is possible to prevent performance degradation, and by reducing the weight of the drive unit, the influence of centrifugal force is small and high-speed operation is possible, and it is also possible to reduce input and noise.

In addition, since aluminum-based materials have excellent free-cutting properties, precision machining of sliding surfaces can be easily performed, improving productivity.Since the solid lubricant dispersion layer is molded integrally with the scroll blade body, a separate process is required. Since this is not necessary, the manufacturing cost itself can be made almost the same as that of a product simply made of an aluminum-based material.

Note that the present invention is not limited to the above embodiments,
Various modifications can be made without departing from the gist of the invention. For example, in the embodiments described above, the present invention was applied to the manufacture of scroll blades used in scroll fluid machines having a compression function, but it can also be applied to scroll blades used in scroll fluid machines having an expansion function.

[Effects of the Invention] As explained above, according to the method for manufacturing a scroll blade of the present invention, a scroll blade that can reliably and stably prevent severe wear caused by aluminum-based materials over a long period of time can be obtained at a low cost. Therefore, it is possible to provide a highly reliable scroll fluid machine with excellent durability and low drive loss.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the manufacturing process of an embodiment of the present invention, Fig. 2 is a sectional view showing the schematic configuration of a scroll compressor using scroll blades manufactured according to an embodiment of the invention, and Fig. 3 is a graph showing the torque-load relationship between a scroll blade manufactured according to an embodiment of the present invention and a conventional product,
FIG. 4 is a graph showing the relationship between the coefficient of friction and the load of a scroll blade manufactured according to an embodiment of the present invention and a conventional product. 1... Mold for forming scroll blades, 2...
・Carbon mixed aluminum powder, 3...S1-containing aluminum powder, 5...Scroll blade, 6.
...End plate part, 7...Wrap, 8...
...Solid lubricant dispersion layer. Applicant Toshiba Corporation Patent Attorney Sasa Suyama − Kiku! (Kgf) Third cargo! (Kgf)

Claims (1)

[Scope of Claims] In manufacturing a scroll blade that compresses or expands gas by forming spiral wraps upright on opposing plate surfaces of a pair of end plates and meshing these wraps, the top of the wraps is provided. Using a mixed powder in which a solid lubricant is dispersed in an aluminum-based material forming the vicinity portion and an aluminum-based material forming the scroll blade body, a dispersed layer of the solid lubricant is formed in the vicinity of the top of the wrap. A method for manufacturing a scroll blade, characterized in that the scroll blade is simultaneously molded integrally with the scroll blade main body by a powder metallurgy method.