JPH07286589A - Slide member for compressor - Google Patents

Abstract

PURPOSE:To provide a slide member for a compressor which has sufficient abrasion resistance and impact resistance, in which peeling or cracking of a coating film is restricted, and which has excellent compatibility with counter materials. CONSTITUTION:When a vane 1 which slides to a roller of a rotary compressor is a slide member for a compressor, a nitride layer 3 is formed on an outer surface of its base material, and an ion plating layer 4 comprising Cr2N--type chrome nitride and Cr2-type chrome nitride existing as they are mixed is formed on the nitride layer 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sliding member for a compressor, and more particularly to a sliding part such as a vane or a roller that relatively slides in the compressor.

[0002]

2. Description of the Related Art In a rotary compressor, a roller is eccentrically rotated in a roller housing, a vane is slidably held in a vane groove formed in the roller housing, and a nose portion at an inner end of the vane radial direction is a roller. It is in sliding contact with the outer peripheral surface. Here, as a sliding member for a compressor such as a vane, for example, one having a coating layer formed on a base material for the purpose of improving sliding wear resistance is known (Japanese Patent Laid-Open Publication No. Sho. 64-63692). The coating layer has a relatively low treatment temperature of about 150 to 400 ° C. and forms a dense and smooth coating layer while preventing thermal deterioration of the base material made of, for example, an aluminum alloy or an iron-based alloy. It is formed mainly by the ion plating method because it can be formed.

On the other hand, steel containing Cr, Mo, W and V,
A vane of a rotary compressor made of a material obtained by subjecting cast iron or a sintered alloy to a nitriding treatment is also known (JP-A-60-2).
28794). This vane has the advantage that it has excellent wear resistance and can withstand severe lubrication conditions.

[0004]

However, when the ion plating method is used, since the hardness difference between the base material and the coating film is large, the impact resistance is poor and the coating film is easily peeled off. was there. Specifically, the hardness of the high-speed tool steel (SKH51), which is the base material, is about Hv750, whereas the hardness of the titanium nitride coating film by the ion plating method is about Hv2500, which is considerably high. There is a difference.

On the other hand, in a vane made of a material obtained by subjecting a sintered alloy to nitriding treatment, for example, the hardness of high-speed tool steel (SKH51), which is a base material, is about Hv750 as described above. The hardness of the material obtained by subjecting the speed tool steel to the nitriding treatment is about Hv1250. Therefore, although the hardness of the base material is increased and the wear resistance is considerably improved, there is a problem that the wear resistance in a harsh environment is not always sufficient.

By the way, in the conventional sliding member for a compressor, in order to manufacture a vane having abrasion resistance, a salt bath soft nitriding treatment or a gas nitriding treatment is adopted, and a steel material having a vane shape is formed. A nitriding layer was formed on the surface of, but in these soft nitriding treatments, it is difficult to form a compound layer (Fe ₄ N) important for wear resistance, and it is difficult to control the layer thickness. There was a problem.

On the surface of the compound layer, Fe which is hard and brittle
_{2-3 The} amount of dimensional change and dimensional variation in which the N layer (ε layer) is formed is large, and finishing processing is required after the nitriding treatment. Further, the vane is not necessarily compatible with the wear of the roller and the vane groove. Not ideal.

Therefore, the present invention provides a compressor slide having sufficient wear resistance and impact resistance, suppressing peeling and cracking of the coating film, and being excellent in wear compatibility with the mating material. An object is to provide a moving member.

[0009]

In order to achieve the above object, the present invention provides a sliding component for a compressor that relatively slides in a compressor, which is formed on a base material of the sliding component. Forms a nitride layer, and Cr ₂ N-type chromium nitride and Cr are formed on the nitride layer.
Provided is a sliding member for a compressor in which an ion plating layer in which N-type chromium nitride is mixed is formed.

[0010]

According to the sliding member for a compressor of the present invention having the above-mentioned structure, the abrasion resistance is improved as compared with the sliding member provided with a usual ion plating layer. Further, when such a compressor sliding member is applied to, for example, a vane of a rotary compressor, compatibility with a roller or a vane groove, which is a mating member, in wear is improved.

[0011]

1 and 4 show an example in which a sliding member for a compressor according to a first embodiment of the present invention is applied to a rotary compressor.
It will be explained based on.

In the rotary compressor, as shown in FIG. 3, the roller 30 has a rotating shaft 40 inside the roller housing 20.
The vane 1 is held in the vane groove 20a formed in the roller housing 20 so as to be slidably movable in the radial direction of the roller housing. Vane 1
The nose portion at the inner end in the radial direction of is in sliding contact with the outer peripheral surface of the roller 30. Therefore, the vane 1 and the roller 30, and the vane 1 and the vane groove 20a are in a relative sliding relationship.

A vane 1 which is an example of a sliding member for a compressor.
Has a nitride layer 3 on the base material 2, and further has an ion plating layer 4 on the nitride layer 3. In the first embodiment, the nitride layer 3 and the ion plating layer 4 are formed on both the sliding surface for the vane groove 20a and the sliding surface for the roller 30.

As the material for forming the base material 2, for example, iron-based material, graphite-based material, iron-based sintered material, aluminum-based material,
Examples include titanium materials that have been conventionally used as vane forming materials. Of these, iron-based materials are preferable, and high speed tool steel is particularly preferable.

A nitride layer 3 is formed on the base material 2.
The nitride layer 3 formed on the base material 2 has the function of improving the hardness of the base material, and thus the sliding member for a compressor has improved wear resistance. The nitride layer 3 is formed by subjecting the base material 2 to an ion nitriding treatment. Here, as the ion nitriding method, either a so-called ion pure nitriding treatment or an ion soft nitriding treatment can be adopted. Specifically, in the case of the ion pure nitriding treatment, after degreasing and cleaning the base material 2, the base material 2 is preheated, and the preheated base material 2 is subjected to a pressure of about 0.5 to 10 torr ( H ₂ + N ₂ ) gas atmosphere or NH ₃ gas atmosphere is placed in a closed container, a voltage of 100 to 500 V is applied with the base material 2 as a cathode and the closed container as an anode, and ionized nitrogen generated by glow discharge generated at this time and the mother gas. The base material 2 is nitrided by a heating reaction with the material 2.

[0016] In the case of ion nitrocarburizing treatment, the ion pure nitriding above, (H ₂ + N ₂₎ in place of the gas atmosphere or NH ₃ gas atmosphere, the atmosphere (N ₂ + C
₃ H ₈ ) gas atmosphere or (hydrocarbon-based gas such as C ₄ H ₁₀ , C ₂ H ₂ , CH ₄ ) atmosphere may be used.

The surface hardness of the nitride layer 3 thus formed is Vickers hardness Hv1200 or more. The thickness of the nitride layer 3 is usually 1 μm
m or more, preferably 5 μm or more, and the thickness of the diffusion layer is usually 40 μm or more, preferably 50 μm or more.

More specifically, for example, high speed tool steel (S
KH51) was preheated at 430 ° C. for 2 hours and then gas pressure 4
torr, gas ratio of N ₂ gas and H ₂ gas N ₂ : H ₂ = 7:
3. When the ion pure nitriding treatment was performed for 30 minutes under the condition of temperature of 520 ° C., the base material surface was composed of a compound layer having a thickness of 5 μm and a diffusion layer having a thickness of 80 μm inside the compound layer. A nitride layer 3 having a surface hardness of Hv1200 is formed.

An ion plating layer 4 is formed on the nitride layer 3. The ion plating layer 4 is N
₂ By adjusting the gas pressure, Cr ₂ N-type chromium nitride and CrN-type chromium nitride are mixed. Here, the substrate temperature in the ion plating method is usually controlled to about 200 to 600 ° C. Specifically, nitrogen is used as a reaction gas, Cr is evaporated in the reaction gas, ionized in a gas phase state, and a reaction product of the reaction gas and vaporized material ions (on the surface of the base material negatively biased ( A mixture of CrN and Cr ₂ N) is formed. The hardness of the ion plating layer 4 thus formed is Vickers hardness Hv1800 or higher. The thickness is usually 2 μm or more, preferably 5 μm.
It is m or more.

The ion plating layer 4 formed on the nitrided layer 3 not only has the function or function of further improving the wear resistance of the sliding member for a compressor, but is also dense and smooth, so that it can be used as a mating member. Has less aggression, and the amount of wear of the other party also decreases. Moreover, since the hardness of the base material 2 is improved by the nitride layer 3 interposed between the base material 2 and the ion plating layer 4, the hardness difference between the ion plating layer 4 and the base material is reduced, and The wear resistance is improved and the occurrence of peeling and cracks is suppressed. And, it is particularly important that the ion plating layer 4 is made of a mixed composition film of CrN-type chromium nitride and Cr ₂ N-type chromium nitride so that it is superior in wear resistance to the chromium nitride film of Cr ₂ N-type alone. It means that there is. Note that Cr
The content ratio of N-type chromium nitride and Cr ₂ N-type chromium nitride is 50:50.

FIG. 2 is a sectional view showing a sliding member for a compressor according to a second embodiment of the present invention. In the second embodiment, the vane 1A, which is an example of a sliding member for a compressor, is similar to the first embodiment in that the nitride layer 3 is formed on substantially the entire peripheral surface of the base material 2, but the ion is used. The plating layer 4A is different in that it is formed only on the nose portion that is in sliding contact with the mating roller 30. With such a configuration, the production efficiency is improved and the cost can be reduced as compared with the case where the ion plating layer 4A is formed on the entire surface of the nitride layer 3. The forming material, thickness, and the like of the base material 2, the nitride layer 3, and the ion plating layer 4A are the same as those in the vane 1 shown in FIG.

Using an Amsler type abrasion tester, the sliding resistance of the compressor was tested for abrasion resistance and opponent attack. As shown in FIG. 4, the test piece 13 (corresponding to the vane) was formed into a donut shape (outer diameter 40 mm, inner diameter 16 mm, thickness 10 mm), and its outer peripheral surface was subjected to various surface treatments to give test pieces 1 to 3. The test piece 13 was dipped in the container 11 in which the lubricating oil 12 was stored, and these were used as rotating pieces in the plane contact sliding wear test. On the other hand, 18mm × 15mm × 5m
The mating member 50 (corresponding to a roller) processed into a flat plate of m was pressed as a fixed piece to rotate the rotating piece 13. Test piece 1
To 3, the mating materials were as follows.

Test piece 1 (product of the present invention): SKH5 as base material
1 in which an ion plating layer having a thickness of 4 μm, which is a mixture of CrN-type chromium nitride and Cr ₂ N-type chromium nitride, is formed on the nitride layer having a thickness of 80 μm. Test piece 2 (comparative example): A base material was SKH51, and an ion plating layer having a thickness of 4 μm made of Cr ₂ N-type chromium nitride was formed on a nitride layer having a thickness of 80 μm. Test piece 3 (comparative example): SKH51 base material, thickness 8
A nitride layer of 0 μm is formed. Rotating piece: Monikuro (cast iron containing molybdenum, nickel, chromium)

The test conditions are as follows, and the test results are shown in FIG. Peripheral speed: 1 m / sec (478 rpm) Oil temperature: 75 ° C Load: 100 kg Time: 7 hours Lubricating oil: Ester oil

As is clear from FIG. 5, the wear amount of the nitriding-only test piece 3 was 10.9 μm and the wear amount of the mating material was 1.1 μm, and it did not have sufficient wear resistance. , The opponent's aggressiveness is also high. Further, in the test piece 2 having the ion plating layer made of Cr ₂ N-type chromium nitride, the wear amount was 0.8 μm and the wear amount of the mating material was 0 μm. Therefore, by coating the ion plating layer, the wear resistance is somewhat improved, and the opponent attacking property is reduced. Compared with these, in the test piece 1 having the ion plating layer in which CrN-type chromium nitride and Cr ₂ N-type chromium nitride were mixed, the wear amount was 0.2 μm, the wear amount of the mating material was 0 μm, and It can be seen that the wear resistance is remarkably improved.

[0026]

According to the sliding member for a compressor of the present invention described above, the abrasion resistance is greatly improved and the impact resistance is also excellent, and the peeling and cracking of the film are suppressed. It is possible to reduce the wear amount of the mating material as well as the wear.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a sliding member for a compressor of the present invention.

FIG. 2 is a cross-sectional view showing another embodiment of the sliding member for the compressor of the present invention.

FIG. 3 is a partial explanatory view showing a rotary compressor using a sliding member for a compressor of the present invention.

FIG. 4 is a schematic view showing an Amsler type abrasion tester used in an experimental example.

FIG. 5 is a graph showing the amount of wear in a wear test.

[Explanation of symbols]

 1, 1A Vane as sliding member for compressor 2 Base material 3 Nitriding layer 4 Ion plating layer 20a Vane groove as mating material 30 Roller as mating material

Claims (1)

[Claims] 1. A sliding component for a compressor, which relatively slides in a compressor, wherein a nitride layer is formed on a base material of the sliding component, and Cr ₂ is formed on the nitride layer. N-type chromium nitride and C
A sliding member for a compressor, wherein an ion plating layer in which rN-type chromium nitride is mixed is formed.