JPH08261169A - Sliding part and scroll - Google Patents

Abstract

PURPOSE: To improve a surface roughness and sliding characteristic of a hard oxidized protecting film by rectifying a multiphase AC power supply converted into a DC power supply, and by smoothing this DC power supply supplied to a sliding part, to supply a stable DC power supply without distortion to a sliding part, and by making uniform the current density in each part of the sliding part, that is, an oxygen generating factor. CONSTITUTION: A compound protecting film 4, comprising a hard oxidized protecting film (Al2 O3 ) 4a and a fluororesin-made soft protecting film 4b, is formed in a surface of volute laps 1b, 2b. A rectifier circuit 7 is connected to a three-phase 200V AC power supply 6 in manufacturing device 5 of the compound protecting film 4. This rectifier circuit 7 is a thyristor control system with a conduction angle adjustable, to convert into a DC power supply. A smoothing circuit 8 is connected to the rectifier circuit 7, to smooth the DC power supply converted by the rectifier circuit 7. Since output voltage of the rectifier circuit 7 is smoothed by the smoothing circuit 8, at both the time of rated capacity and the time of capacity less than the rated, a fluctuation amount of the DC power supply is decreased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sliding part having a sliding part made of an aluminum material and a scroll.

[0002]

2. Description of the Related Art In an aluminum scroll used in a compressor, a composite protective film is formed on the sliding surface of either a fixed scroll or an orbiting scroll to improve sliding characteristics and the like. Proposed. In the case of this configuration, the composite protective film is composed of a hard oxidation protective film obtained based on anodizing the scroll and a soft protective film made of a fluororesin, and in forming the hard oxidation protective film. Uses a rectifier circuit using a thyristor control system to convert a three-phase 200V AC power source into a DC power source and supplies this DC power source to the scroll.

In the above-mentioned anodizing process, the conduction angle of the rectifying circuit is adjusted according to the size (resistance value) of the scroll, and the current value flowing between the anode (scroll) and the cathode can be maintained at a predetermined value. Has been done. Therefore, depending on the size of the scroll, the process may be performed in a state where the rated capacity of the rectifier circuit is less than the rated capacity. 7A and 7B show voltage waveforms output from the rectifier circuit, FIG. 7A being a voltage waveform at the rated capacity of the rectifier circuit, and FIG. 7B being a voltage waveform below the rated capacity. The voltage waveform is shown. As shown in the figure, a voltage waveform with a small amount of fluctuation is obtained at the rated capacity, and when the voltage is below the rated capacity, the fluctuation of the voltage waveform becomes large. Note that FIG.
(A ') is a current waveform with respect to the voltage waveform of (a),
(B ') is a current waveform with respect to the voltage waveform of (b).

[0004]

However, in the above-mentioned prior art, since the hard oxidation protection film is formed by directly applying the DC power source converted by the rectifier circuit to the scroll, as shown in FIG. 7B. In particular, the voltage fluctuation was large when the capacity was below the rated capacity, and the fluctuation of the current flowing in the electrolytic solution was also large.

Since the aluminum material generally contains impurities, there is some variation in the conductivity of each part. Therefore, when the fluctuation of the current flowing in the electrolytic solution becomes large, the current density in each part of the aluminum material, that is, the oxygen generation rate varies. Since the hard oxidation protection film is formed as oxygen is generated on the surface of the aluminum material, if the oxygen generation rate varies, the surface roughness of the hard oxidation protection film deteriorates. Therefore, it is difficult to say that the conventional scroll has a poor surface roughness and that the sliding characteristics and the like have been sufficiently improved.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a sliding component and a scroll having a good surface roughness and a sufficient sliding characteristic.

[0007]

According to a first aspect of the present invention, there is provided a sliding component comprising a sliding portion made of an aluminum material, a hard oxidation protective film formed on the surface of the sliding portion and obtained by anodizing treatment, and fluorine. And a composite protective film made of a soft protective film made of a system resin, wherein the hard oxidation protective film smoothes a DC power source obtained by rectifying a multi-phase AC power source and supplies the DC power source to the sliding portion. It is characterized by being formed by.

According to a second aspect of the present invention, there is provided a scroll having a sliding portion made of an aluminum material and a surface of the sliding portion.
With a hard oxide protective film obtained by anodizing treatment and a composite protective film consisting of a soft protective film made of a fluororesin,
The hard oxidation protection film is characterized in that it is formed based on smoothing a DC power source obtained by rectifying a multi-phase AC power source and supplying the smoothed DC power source to the sliding portion.

[0009]

According to the above means, the multi-phase AC power supply is rectified and converted into the DC power supply, and the DC power supply is smoothed and supplied to the sliding portion. For this reason, a stable direct current power without distortion is supplied to the sliding portion, so that the current density in each portion of the sliding portion, that is, the oxygen generation rate is made uniform. Therefore, since the surface roughness of the hard oxidation protection film is improved, the sliding characteristics of the sliding parts and the scroll are sufficiently improved.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS.
It will be explained based on. 2 and 3 show a fixed scroll 1 and an orbiting scroll 2 made of an aluminum material. Here, the fixed scroll 1 has an end plate 1a.
And a spiral wrap 1b (corresponding to a sliding portion) provided upright on the end plate 1a.

The orbiting scroll 2 includes an end plate 2a and an end plate 2a.
The spiral wrap 2b of the orbiting scroll 2 is meshed with the spiral wrap 1b of the fixed scroll 1. The tip surfaces of the spiral wraps 1b and 2b are in close contact with the end plates 2a and 1a on the opposite side,
The side surfaces of and 2b are in line contact with each other. This allows
A discharge port 1c is formed in the central portion of the fixed scroll 1 in which two compression chambers 3, 3 which are point-symmetric with respect to the centers of the spiral wraps 1b and 2b are formed. Then, when the orbiting scroll 2 orbits with respect to the fixed scroll 1 and the line contact portions of both the spiral wraps 1b and 2b move toward the center of the spiral (the discharge port 1c), the internal volume of the compression chamber 3 decreases. As a result, the gas in the compression chamber 3 is compressed and discharged from the discharge port 1c. The fixed scroll 1 and the orbiting scroll 2 correspond to sliding parts and are used in a scroll type fluid machine such as a car air conditioner.

On the surfaces of the spiral wraps 1b and 2b, as shown in FIG. 1, a composite protective film 4 consisting of a hard oxide protective film (Al2 O3) 4a and a soft protective film 4b made of a fluororesin is formed. There is. Hereinafter, the manufacturing apparatus 5 for the composite protective film 4
And the manufacturing method will be described in detail.

First, in FIG. 4, a rectifier circuit 7 is connected to the three-phase 200V AC power supply 6. This rectifier circuit 7
Is a thyristor control system whose conduction angle can be adjusted, and converts the three-phase 200V AC power supply 6 into a DC power supply by three-phase full-wave rectification. A smoothing circuit 8 is connected to the power supply line (+) 7a and the power supply line (−) 7b of the rectifier circuit 7. The smoothing circuit 8 includes a choke coil 8a inserted in a power supply line (+) 7a and a capacitor 8b connected between the power supply line (+) 7a and the power supply line (-) 7b.
And a resistor 8c connected between the power supply line (+) 7a and the power supply line (-) 7b, the DC power supply converted by the rectifier circuit 7 is smoothed.

5A and 5B show voltage waveforms output from the smoothing circuit 8, FIG. 5A being a voltage waveform when the rectifying circuit 7 has a rated capacity, and FIG. 5B being a rated capacity. Shows the voltage waveform when it is below. In this case, since the output voltage of the rectifier circuit 7 is smoothed by the smoothing circuit 8, the fluctuation amount of the DC power source is small both at the rated capacity and at the time of falling below the rating. In addition, (a ') of FIG.
The current waveform with respect to the voltage waveform of (a), (b '),
It is a current waveform with respect to the voltage waveform of (b).

The power supply line (+) 7a of the rectifier circuit 7 has a structure shown in FIG.
As shown in FIG. 3, the workpiece 9 is connected to the
Cathode plates 10 and 10 are connected to b (cathode). The object 9 to be processed is composed of scrolls 1 and 2, and functions as an anode as described later. A sulfuric acid aqueous solution is stored in the electrolytic bath 11, and the spiral wrap 1b of the fixed scroll 1, the spiral wrap 2b of the orbiting scroll 2, and the cathode plates 10 and 10 are immersed in the sulfuric acid aqueous solution.

Then, the DC power source smoothed by the smoothing circuit 8 is applied between the scrolls 1 and 2 and the cathode plates 10 and 10, and when a current starts to flow in the sulfuric acid aqueous solution, the surface of the spiral wraps 1b and 2b. Electrode reaction of the formula (1) occurs, and electrons are extracted from the water molecules toward the spiral wraps 1b and 2b.

2H2 O → O2 + 4H + + 4e- (to scrolls 1 and 2) (1) As a result, oxygen is generated on the surfaces of the spiral wraps 1b and 2b, and the generated oxygen causes the surface of the spiral wraps 1b and 2b. A porous hard oxidation protection film 4a is formed on the surface. The following equation (2) shows the electrode reaction in the cathode plate 10. 4H + + 4e- (from cathode plate 10) → 2H2 (2)

A current detector 12 is inserted in the power supply line (-) 7b of the rectifier circuit 7. The current detector 12 is composed of a moving coil type ammeter 12a and a shunt 12b, and the moving coil type ammeter 12a displays the value of the current flowing through the device. Therefore, while watching the display of the current detector 12, the conduction angle of the rectifier circuit 7 is adjusted according to the size (resistance value) of the scrolls 1, 2, and the scroll 1,
The current flowing between 2 and the cathode plate 10 is maintained at a predetermined value. Reference numeral 15 indicates an anodic oxidation processing section including a rectifying circuit 7, a smoothing circuit 8, an electrolytic cell 11 and a current detector 12.

A sealing treatment tank 13 is provided on the side of the electrolytic cell 11. A nickel acetate solution is stored in the sealing treatment tank 13, and the scrolls 1 and 2 after the formation of the hard oxidation protection film 4a are washed with water and then immersed in the nickel acetate solution. Then, when the nickel acetate solution is allowed to stand for 1 to 5 minutes while being heated to about 60 to 80 ° C., a hydration reaction occurs (formation of Al2 O3 .H2 O), and the hole of the hard oxidation protection film 4a is half closed.

On the side of the sealing treatment tank 13, a lubrication treatment tank 14 made of stainless steel is provided. The lubrication tank 14 contains polytetrafluoroethylene (PTF).
E) The lubrication treatment solution in which the particles are dispersed is stored,
The scrolls 1 and 2 for which the sealing treatment has been completed are washed with water and then immersed in a lubricating treatment solution. Then, if the lubrication treatment solution is allowed to stand for 5 minutes or more while being heated to about 30 to 40 ° C., the hard oxide protective film 4a is coated with PTFE in the lubrication treatment solution.
Particles are adsorbed.

After the adsorption of the PTFE particles is completed, the scrolls 1 and 2 are dried to obtain the scrolls 1 and 2.
The surface treatment of is completed. Thereafter, when the scrolls 1 and 2 slide while making contact with the other side, the PTFE particles are deformed to form a thin soft protective film 4b made of a fluororesin, and the hard oxidation protective film 4a is sufficiently sealed. To be done.

The reason why the hard oxidation protection film 4a is semi-sealed in the above-mentioned sealing treatment step is that the PTFE is used in the lubricating treatment step.
This is because the particles are easily adsorbed on the hard oxidation protection film 4a. An insulating sheet (not shown) made of vinyl chloride is attached to the inner surface of the lubrication treatment tank 14.
4 and the lubricating treatment solution are electrically insulated by an insulating sheet. Therefore, even if a stray current is applied to the lubrication processing tank 14 from surrounding equipment, the lubrication processing solution is prevented from being decomposed.

A carrier (not shown) movable in the horizontal direction and the vertical direction is provided above each of the processing tanks 11, 13, and 14, and a plurality of hangers (not shown) are provided in the carrier. Is hung. Then, scrolls 1 and 2 are suspended from the hangers, and the scrolls 1 and 2 are supplied to the processing tanks 11, 13 and 14 based on the horizontal and downward movement of the carrier.

According to the above embodiment, the rectified output of the rectifying circuit 7 is smoothed and supplied to the scrolls 1 and 2.
Therefore, even in an operating state where the capacity is below the rated capacity, as shown in (b) and (b ') of FIG. Therefore, since the oxygen generation rate in each part of the scrolls 1 and 2 is made uniform, the surface roughness of the hard oxide film 4a is improved to the same level as in the rated operation. As a result of forming an oxide film having a film thickness of 20 μm and a hardness of HV450 using the AC8C material, the surface roughness of this example was improved to RZ4.2 in comparison with the conventional surface roughness RZ9.5.

Moreover, since the soft protective film 4b is formed on the surface of the hard oxidation protective film 4a, the abrasion resistance on the surface of the spiral wrap 1b and the surface of the orbiting scroll 2b is improved and the frictional resistance is reduced. Therefore, the initial sliding characteristics of the scrolls 1 and 2 are improved and the familiar time is shortened, and the sealability of the compression chambers 3 formed between the scrolls 1 and 2 is improved.

By the way, since the anodic oxidation treatment is carried out at a relatively low voltage below the rated capacity, the fluctuation of the rectified output becomes large, and the surface roughness of the hard oxidation protection film tends to be deteriorated. Therefore, it is generally believed that the hard oxidation protection film has a poor surface roughness, and it has rarely been applied to parts that require high sliding characteristics. For this reason, in the past, the fact is that the requirement for high sliding characteristics has been met by surface measures such as adding Ni to the electrolytic solution and cutting the hard oxidation protection film.

In the present embodiment, attention is paid to the fact that when the fluctuation of the power source becomes large, the current density in each part of the object to be processed, that is, the oxygen generation rate varies, and the surface roughness of the hard oxidation protection film deteriorates. It was devised to take fundamental measures against the cause of the deterioration of the degree of deterioration, and it is possible to break the convention that the hard oxide protective film has poor surface roughness.

Although the smoothing circuit 3 is composed of the choke coil 3a, the capacitor 3b and the resistor 3c in the first embodiment, the present invention is not limited to this, and the second embodiment of the present invention will be described. As shown in FIG. 6, the smoothing circuit may be composed of the choke coil 3a.

In the first and second embodiments, the composite protective film 4 is formed on both the spiral wrap 1b of the fixed scroll 1 and the spiral wrap 2b of the orbiting scroll 2, but the invention is not limited to this. No, swirl wrap 1
Alternatively, only one of b and 2b may be formed.

Although the thyristor control type rectifier circuit 7 is used in the first and second embodiments, the present invention is not limited to this, and a thyristor control type rectifier circuit is used, for example. Is also good.

Further, in the above-mentioned first and second embodiments, the sealing treatment step was carried out in order to adsorb the PTFE particles to the scrolls 1 and 2, but the present invention is not limited to this, and the hard oxide protective film is not limited thereto. It may be omitted when a fluorine-based resin that easily bonds to 4a is used.

Further, in the above-mentioned first and second embodiments, the scrolls 1 and 2 are exemplified as the sliding parts, but the invention is not limited to this, and mechanical parts such as shafts and gears, cylinders, valves and the like. It is applied to all sliding parts that require high sliding characteristics such as automobile parts.

[0033]

As is clear from the above description, according to the sliding component and the scroll of the present invention, the surface roughness of the hard oxidation protection film can be improved, and therefore the sliding portion wear resistance is improved. And the frictional resistance is reduced. Therefore, the improvement of the initial sliding characteristics and the shortening of the running-in time are realized.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view of a main part showing a first embodiment of the present invention.

FIG. 2 is a sectional view showing the overall structure of a scroll.

FIG. 3 is a sectional view taken along the line EE in FIG.

FIG. 4 is a schematic view of a surface treatment apparatus.

FIG. 5 is a diagram showing a voltage waveform and a current waveform of a DC power supply.

FIG. 6 is a schematic view of an anodizing unit showing a second embodiment of the present invention.

FIG. 7 is a view corresponding to FIG. 5 showing a conventional example.

[Explanation of symbols]

1 is a fixed scroll (sliding part, scroll), 2 is an orbiting scroll (sliding part, scroll), 1b and 2
b is a spiral wrap (sliding part), 4a is a hard oxidation protection film, 4
b represents a soft protective film, and 4 represents a composite protective film.

Claims (2)

[Claims] 1. A composite protective film comprising a sliding portion made of an aluminum material and a hard oxidation protective film formed on the surface of the sliding portion and obtained by anodizing treatment and a soft protective film made of a fluororesin. The sliding component, wherein the hard oxidation protection film is formed based on smoothing a DC power source obtained by rectifying a multi-phase AC power source and supplying the smoothed DC power source to the sliding portion. 2. A sliding portion made of an aluminum material, and a composite protective film formed on the surface of the sliding portion and made of a hard oxide protective film obtained by anodizing treatment and a soft protective film made of a fluororesin. The scroll is characterized in that the hard oxidation protection film is formed on the basis of smoothing a DC power source obtained by rectifying a multi-phase AC power source and supplying the smoothed DC power source to the sliding portion.