JPH06341385A - Vane for compressor - Google Patents

Abstract

PURPOSE:To decrease the vane wear generated in relation to the sliding surfaces between the cylinder block inside surface and a vane groove provided in a rotor by furnishing an ion plating layer chiefly containing Cr and N over the outer surface of the wane which is inserted with possibility of emerging and retracting from/in the vane groove. CONSTITUTION:A front and a rear side-plate 2a, 2b are fixed to the front and rear of a cylinder block 1, and a compressor body 3 is formed. A cylindrical rotor 4 is accommodated in the compressor body 3, and the steel shaft 5 of this rotor 4 is supported on the two side-plates 2a, 2b by bearings 6a, 6b. Vane 8 is inserted in a vane groove 7 provided in the rotor 4. Therein an ion plating layer chiefly containing Cr and N is installed over the outer surface of the vane 8. This permits decreasing the wear of vane 8 generated in relation to the sliding surfaces between the inside surface of the cylinder block 1 and the vane groove 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vane suitable for a vane type compressor for compressing a gas such as a refrigerant gas.

[0002]

2. Description of the Related Art In a vane compressor, side plates are fixed to both sides of a cylinder block having a generally cylindrical or elliptical inner cylinder shape to form a compressor body. A rotor is arranged, a plurality of vane grooves are provided in the rotor or cylinder block toward the radial direction, the vane is inserted and retracted freely, and the vane is pressed against the inner peripheral surface of the cylinder block or the outer peripheral surface of the rotor. On the other hand, by rotating the rotor, the gas in the compression chamber partitioned by the vanes is compressed. This vane type compressor is often used for the purpose of air conditioning by being loaded in a refrigerator or a vehicle. The configuration of the main parts of the conventional vane compressor will be described.

For the cylinder block, flake graphite cast iron is generally used because of its good sliding characteristics and machinability. As the rotor, a steel material integrated with the shaft or a rotor made of an iron-based sintered alloy that is press-fitted into the steel shaft is often used. Since the side plate is required to have seizure resistance on the surface that slides on the rotor or vane, flake graphite cast iron or iron-based sintered alloy, which is a material having good oil retention, is often used. As described above, consideration is given to the material combination from the viewpoint of sliding and the coupling between the rotor and the shaft. However, it has the following problems.

[0004]

Problems such as seizure and wear of the vanes are a problem between the cylinder block and the vanes. In particular, under operating conditions such as low speed and high load where the temperature rises, the oil film between the sliding surfaces becomes thin and easily breaks, resulting in significant wear on the vane and the inner peripheral surface of the cylinder block. Between the rotor and the vane, seizure between the groove surface of the rotor and the side surface of the vane sliding on the groove surface is a problem. For example, the vanes reciprocate in the grooves of the rotor, which wear and seize due to insufficient lubrication. By using a high Si aluminum alloy as the material of the rotor, the tendency of seizure is mitigated, but since the lubricating oil film does not exist on the sliding surface at the time of starting, scratches that occur on the sliding surface due to repeated starting are It becomes large, and eventually seizure occurs. Therefore, it is an object of the present invention to solve the above-mentioned problems of the conventional technology.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention makes it possible to project and retract in the radial direction so as to make sliding contact with a mating member through an ion plating layer, and the ion plating layer is made of Cr and N. Provided is a vane for a compressor, which is a layer containing as a main component.

The vane has a top portion that slides with the cylinder block, a uniform fine mixed phase of metallic chromium and chromium nitride having a thickness of 1 to 20 μm, and 1 to 20 μm on the side surface of the vane that slides with the groove portion of the rotor. Provide the same kind of hard ion plating film with the thickness of.

[0007]

The function of the cylinder block is not only excellent sliding compatibility with the ion plating film provided on the top of the vane but also rigidity and strength of the cylinder block.
By providing a hard ion plating film having a thickness of 1 to 20 μm on the top of the vane that is in sliding contact with the inner peripheral surface of the cylinder block, wear and seizure between both members are at a level where there is no practical problem. . If the thickness of the hard ion plating film is less than 1 μm, it will not withstand wear for a long period of time, and when an aluminum alloy is used as the base, if the hardness of the aluminum alloy is low, it will be depressed due to the load applied. . On the other hand, when it exceeds 20 μm, the adhesiveness is deteriorated and it is easy to peel from the base. As the hard ion plating film, a film made of chromium and nitrogen is used. Ion plating film consisting of chromium and nitrogen is HMV
A hardness of about 1500 to 2200 can be obtained. Particularly preferably, the film has a structure in which chromium and chromium nitride are mixed,
In addition, the hardness is in the range of HMV 1500 to 2000.

The conventional sliding problem was solved by providing the above-mentioned ion plating film containing metallic chromium and nitrogen as the main components on the side surface of the vane that slides in the groove of the rotor. The composition of the coating, its action and hardness are similar to those applied to the top of the vanes.

[0009]

First, the structure of a vane compressor is shown in FIG.
This will be described with reference to FIG. In the figure, a pair of side plates 2a and 2b are fixed to front and rear open portions of a cylinder block 1 having an elliptical inner peripheral surface to form a compressor body. A cylindrical rotor 4 is arranged in the compressor body 3, and a steel shaft 5 of the rotor 4 is connected to the rotor 4. The steel shaft 5 is supported by the bearing portions 6a and 6b of the side plates 2a and 2b, and receives the driving force from the ends. The rotor 4 is provided with vane grooves 7 for accommodating vanes at five locations in the radial direction, and each of the vane grooves has a vane 8.
Is inserted freely. Inside the compressor body 3, a compression chamber 9 surrounded by a cylinder block 1, side plates 2a and 2b, a rotor 4 and vanes is provided.

The periphery of the compressor body 3 is surrounded by a head block 10 that is tightly fixed to one side plate 2a and a case 11 that is tightly fixed to the head block 10. In this case 11, a discharge port 12 communicates with a high pressure chamber 14 surrounded by the compressor body 3 and the case 11, and a suction port 13 communicates with a low pressure chamber 16 separated from a high pressure 14 by a cover 15. When the discharge valve 17 provided in the cylinder block 1 of the high pressure chamber 14 opens, the gas from the compression chamber 9 flows in through the discharge hole 18, while the low pressure chamber 16 is formed in the side plates 2a, 2b. The gas is fed into the compression chamber 9 through the suction hole 19.

The lower portion of the high-pressure chamber 14 is an oil reservoir, and the lubricating oil stored in this oil reservoir is provided with a supply hole formed in the vertical direction of the side plates 2a, 2b by the pressure of the high-pressure chamber 14. 20a, 20b, bearing portion 6a,
6b and the supply grooves 21 formed on the inner surfaces of the side plates 2a, 2b, the vane 8 is pressed against the inner peripheral surface of the cylinder block 1, and the lubrication between the vane groove 7 and the vane 8 is performed. Lubrication between the end surface of the rotor 4 facing the side plate and the bearing portion, and lubrication of the bearing portion. While the rotor 4 rotates and one vane 8 passes through the suction hole 19, gas is sucked from the low pressure chamber 16 into the compression chamber 9 formed between the one vane 8 and the preceding vane 8. , This gas is confined in the compression chamber 9 when one vane 8 passes through the suction hole 19, and is compressed as the volume of the compression chamber 9 becomes smaller, and is discharged when the preceding vane 8 passes through the discharge hole 18. The valve 17 is opened and the high pressure chamber 14 is discharged. In order to prevent the chattering of the vanes, the back pressure chamber 22 is separated from the supply groove 21 and becomes an independent space.

The test material as a vane material is a rapidly solidified powder obtained by air atomization, compression-molded by a cold isostatic press, and hot-extruded. The material was heat-treated (T6 treatment) after cutting, machined and surface-treated. The analysis value, hardness measurement result, coefficient of thermal expansion (RT
The measurement results are shown in Table 1.

[0013]

[Table 1]

The vane was prepared by cutting the extruded material, heat-treating it at T6 and processing it into a predetermined shape, and directed it to the ion plating step. For hard ion plating, the vane is set on a jig, the surface is ultrasonically cleaned in that state, degreasing is performed, and the plate is mounted in the vacuum container of the reactive ion plating apparatus.
After the inside of the container was evacuated to a high vacuum of about 10 ^-5 Torr, the vane was heated to 200 to 300 ° C by the built-in heater, argon gas was introduced, and sputtering was performed at about 0.2 Torr to completely clean the vane surface. I shall. Next, nitrogen gas is introduced into the container, and the flow valve is adjusted so that a predetermined partial pressure of nitrogen gas according to the evaporation rate of Ti, Cr or the like is obtained. Evaporation material Ti, Ti alloy block, Cr, Cr alloy block or Ti
The mixed powder compact of powder and Cr powder is set in advance in the water-cooled copper crucible provided in the vacuum container,
The above materials are vaporized by a hollow cathode type electron gun. Four kinds of coatings described below were provided on the side surface of each vane that slides with the rotor and the top surface that slides with the cylinder block. A film composed of a uniform and fine mixed phase of metallic titanium and titanium nitride was provided by ion plating to give a lap finish. The ion plating of the film is
It was performed by setting a titanium block in a water-cooled copper crucible and irradiating and evaporating it with an electron beam. The obtained titanium nitride has a thickness of 2 to 4 μm and a hardness of 230 in HMV.
It was 0-2700.

A film consisting of a uniform and fine mixed phase of metallic chromium and chromium nitride was provided by ion plating for lapping. It was performed by setting a chrome block in a water-cooled copper crucible and irradiating it with an electron beam to evaporate it. The obtained film has a thickness of 5 to 10 μm and a hardness of H.
It was 1500-1800 in MV.

A film made of a uniform and fine mixed phase of metallic titanium and metallic chromium, and titanium nitride and chromium nitride was provided by ion plating and was lapped. In the water-cooled copper crucible, mixed powder of Ti powder and Cu powder (50:
50) was set and irradiated with an electron beam to evaporate. The thickness of the film obtained is 2-3 μm
The hardness was 1500-2300 in HMV. Metal T
A film consisting of i, metal Al and metal V, and nitrogen was provided by ion plating for lapping. A block of Ti-6Al-4V alloy was set in the water-cooled copper crucible and irradiated with an electron beam to evaporate.
The thickness of the film obtained is 2-3 μm and the hardness is 26 in HMV.
It was 00-2700. As a result of fluorescent X-ray analysis of the film, it was confirmed that Al and V were contained in addition to Ti.

A vane compressor shown in the drawing was assembled with the vanes whose surfaces were ion-plated. For comparison,
A compressor was constructed with the combinations shown in Table 2 including the combinations not subjected to the surface treatment, and the durability test was conducted. The condition of the endurance test is continuous operation at a rotation speed of 550 rpm, and the discharge pressure is 28 kg / cm ² G and the suction pressure is 4 kg / cm ² G, and the torque change and the oil contamination are monitored under the overload condition.
When abnormalities were stopped, the compressor was disassembled and the sliding surface of each part was visually evaluated. For those having no abnormality in torque and oil stain, the same disassembly investigation was conducted after stopping the operation for 250 hours. Table 3 shows the results of the durability test for each combination.

[0018]

[Table 2]

[0019]

[Table 3]

In the comparative example, the oil stains range from 1 to 14
It has stopped due to running for hours. On the other hand, in the combination of the embodiments of the present invention, the result of the investigation after opening after 250 hours of operation showed that although the wear was in progress, there was no failure in the operation.

[0021]

EFFECT OF THE INVENTION A vane type compressor having excellent durability is provided by providing an ion plating film on the tip end of the vane slidingly contacting the inner peripheral surface of the inner cylinder of the cylinder block and the side surface of the vane slidingly contacting the groove of the rotor. be able to.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a compressor using a vane according to an example of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

[Explanation of symbols]

 1 Cylinder Block 2a, 2b Side Plate 4 Rotor 5 Shaft 7 Vane Groove 8 Vane

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsumi Takiguchi 1-37 Hokuto-cho, Kashiwazaki-shi, Niigata Riken Kashiwazaki Plant (72) Inventor Manabu Shinada 1-37 Hokuto-cho, Kashiwazaki-shi, Niigata RIKEN Kashiwazaki Plant

Claims (1)

[Claims] 1. A vane for a compressor, wherein the vane is capable of projecting and retracting in a radial direction and is in sliding contact with a mating member via an ion plating layer, and the ion plating layer is a layer containing Cr and N as main components. .