JP6951175B2 - Sliding member for compressor - Google Patents

Description

The present disclosure relates to a sliding member of a compressor such as a vane type compressor for an automobile air conditioner, in which the sliding member is nickel-low phosphorus plated for the purpose of reducing the cost of the sliding member such as a vane.

The vane type compressor is, for example, one of a cam ring, a rotor rotatably housed in the cam ring and fixed to a drive shaft, a vane inserted into a plurality of vane grooves provided in the rotor, and a cam ring. It is configured to have a front side member fixed to the end face of the vehicle and a rear side member fixed to the other end surface. The drive shaft is rotatably supported by the front side member and the rear side member via a bearing. For example, the front side member has a suction chamber (for example, a suction chamber in which a suction port for working fluid (refrigerant gas) and the suction port communicate with each other. A low-pressure chamber) is formed, and a discharge chamber (high-pressure chamber) in which a working fluid discharge port and the discharge port communicate with each other is formed in the rear side member (see FIGS. 1 to 8 of Patent Document 1).

Aluminum vanes of vane type compressors are generally nickel-phosphorus hard-plated because they are required to have hardness for wear resistance and toughness against impact in order to avoid sliding between aluminum materials. (See, for example, Patent Documents 2-4.).

International Publication WO2008 / 026496 Japanese Unexamined Patent Publication No. 8-158058 Japanese Unexamined Patent Publication No. 2003-161259 Japanese Unexamined Patent Publication No. 2003-184743

The hardness of Ni-P-based plating increases when it is heat-treated, but on the other hand, there is a problem that the toughness of the plating decreases. Therefore, in order to satisfy both hardness and toughness, for example, Ni-P-B-based plating containing boron as in the technique of Patent Document 2 or Patent Document 3, or cobalt as in the technique of Patent Document 4, for example. Ni-Co-P plating containing the above is used. However, these platings are expensive.

In addition, there are cases where Ni particles adhere to the surface of the vane after plating, and a post-process for removing the Ni particles is required, which further increases the cost.

Therefore, an object of the present disclosure is that, in a sliding member for a compressor in which a plating film is applied to a sliding portion, both the hardness and toughness of the plating film are good, the adhesion of Ni particles is suppressed, and the plating film is formed. It is to provide an inexpensive sliding member for a compressor.

The present inventors consider that the electroless nickel low-phosphorus plating layer is a non-heat-treated layer and contains Ni crystallites, and the crystallite diameter thereof is 8 to 11 nm, so that both the hardness and toughness of the plating film are both. It was found that the above was improved, and the problem of the present invention was solved. That is, the sliding member for a compressor according to the present invention is the sliding member for a compressor in which an electroless nickel plating layer containing phosphorus is formed on the surface of a base material made of an aluminum alloy, and the electroless nickel plating is performed. The phosphorus (P) content of the layer is 1.08 % by mass or more and 1.89 % by mass or less, the boron (B) content is 0% by mass or more and 0.01% by mass or less, and cobalt ( The content of Co) is 0% by mass or more and 0.01% by mass or less, the electroless nickel plating layer is a non-heat-treated layer, the electroless nickel plating layer contains Ni crystals, and X-rays are emitted. crystallite size of the crystallites measured by diffractometry Ri 8~11nm der, the Vickers hardness of the electroless nickel plating layer is not more than than 652Hv 750 Hv, the electroless nickel plating layer scratch strength, than 98N It is characterized by being.

In the sliding member for a compressor according to the present invention, it is preferable that the electroless nickel plating layer does not contain boron (B) and cobalt (Co). According to this configuration, the plating solution used can be inexpensive.

In the sliding member for a compressor according to the present invention, the electroless nickel plating layer is preferably a barrel plating layer. According to this configuration, the accumulation of Ni particles is prevented and the smoothness of the member is improved.

The sliding member for a compressor according to the present invention has a base layer between the base material and the electroless nickel plating layer, and the base layer contains phosphorus (P) in an amount of 6.0 to 11.0 mass. It is preferably an electroless nickel-plated layer containing%, and a non-heat-treated layer. According to this configuration, since the base layer is a medium phosphorus type plating layer, the adhesion to the base material is good and the smoothness is improved.

In the sliding member for a compressor according to the present invention, it is preferable that the base layer does not contain boron (B) and cobalt (Co). According to this configuration, the plating solution used can be inexpensive.

In the sliding member for a compressor according to the present invention, the film thickness of the electroless nickel plating layer formed on the surface of the base material, or the base layer and the electroless nickel formed on the surface of the base material. The total film thickness of the plating layers is preferably 15 to 30 μm. According to this configuration, the film thickness of the plating film is optimum for the vane to be used.

In the sliding member for a compressor according to the present invention, the electroless nickel plating layer is preferably a non-dispersion type plating film in which ceramic fine particles are not dispersed in the layer. The hardness and scratch strength of the plating film can be increased.

According to the present disclosure, in a sliding member for a compressor in which a plating film is applied to a sliding portion, both the hardness and toughness of the plating film are satisfied, adhesion of Ni particles is suppressed, and the plating film is inexpensive. A sliding member for a compressor can be provided.

The relationship between the phosphorus content of the electroless nickel-plated layer and the nickel crystallite diameter in the examples is shown. The relationship between the nickel crystallite diameter and the hardness of the electroless nickel-plated layer in the examples is shown. The relationship between the nickel crystallite diameter and the scratch strength of the electroless nickel plating layer in the examples is shown. It is sectional drawing which shows the structural example of the vane type compressor provided with the vane which comprises the sliding member which concerns on this embodiment. It is sectional drawing cut along the line AA of FIG.

Hereinafter, one aspect of the present invention will be described with reference to the accompanying drawings. The embodiments described below are examples of the present invention, and the present invention is not limited to the following embodiments. In addition, the components having the same reference numerals in the present specification and the drawings shall indicate the same components. Various morphological changes may be made as long as the effects of the present invention are exhibited.

First, a sliding member for a compressor will be described. Examples of the compressor include a vane type compressor and a swash plate type compressor. 4 and 5 show the configuration of a vane type compressor as an example. This vane type compressor includes a cam ring 1, a rotor 3 rotatably housed in the cam ring and fixed to a drive shaft 2, and a vane 5 inserted into a plurality of vane grooves 4 provided in the rotor 3. A rear side member 6 fixed to the rear end surface of the cam ring 1 and a shell member 7 surrounding the front end surface and the outer peripheral surface of the cam ring 1 and fitting to the rear side member 6 are provided. .. The drive shaft 2 is rotatably supported by the shell member 7 and the rear side member 6 via bearings. The shell member 7 is formed with a suction port 8 for working fluid (refrigerant gas) and a suction chamber (low pressure chamber) 9 communicating with the suction port 8, and the rear side member 6 has a discharge port 10 for working fluid and its discharge. A discharge chamber (high pressure chamber) 11 communicating with the outlet 10 is formed. A compression space 12 is defined between the inner peripheral surface of the cam ring 1 and the outer peripheral surface of the rotor 3, and the compression space 12 is partitioned by the vane 5 to form a plurality of compression chambers 13, and the volume of each compression chamber is increased. Is changed by the rotation of the rotor 3.

In the vane compressor, during rotation of the rotor 3, the tip surface of the vane 5 and the inner peripheral surface of the cam ring 1, both side surfaces of the vane 5 and the inner surface of the rear side member 6 and the shell member 7, the front and back surfaces of the vane 5 and the vane groove. The inner surface of 4 slides on each other. Therefore, not only high hardness and wear resistance are required for the vane 5, but also foreign matter enters between the rotor 3, the cam ring 1, the rear side member 6, and the shell member, causing scratches on the surface of the vane 5. Even in this case, it is strongly required that the plating layer formed on the surface of the vane 5 does not peel off. When the base material of the vane 5 is formed from a material containing aluminum as a main component for the purpose of weight reduction or the like, if a plating film is formed on the surface of the base material of the vane 5, the hardness and peeling resistance are as described above. Both requirements can be met well. Further, the cam ring 1, rear side member 6, shell member 7, rotor 3, etc. of the vane compressor can be considered as sliding materials, and a plating film can be formed on the surface thereof to satisfy the requirements for hardness and wear resistance. can.

Similarly, in the case of a swash plate compressor, a plating film can be formed at a portion where the members slide to meet the requirements for hardness and wear resistance.

The material of the sliding member is, for example, an aluminum alloy. Examples of the aluminum alloy include aluminum alloys such as 2000 series, 4000 series, 5000 series, 6000 series, and 7000 series, and high silicon-containing aluminum alloys such as ADC10, ADC12, ADC14, and A390. In the present embodiment, the material of the sliding member is preferably an aluminum alloy.

Next, a sliding member for a compressor on which a plating film (also referred to as a plating layer) is formed will be described. In the compressor sliding member according to the present embodiment, an electroless nickel plating layer is formed at least at the sliding portion. That is, the sliding member for a compressor according to the present embodiment is the sliding member for a compressor in which an electroless nickel plating layer containing phosphorus is formed on the surface of a base material made of an aluminum alloy. The phosphorus (P) content of the plating layer is 1.0% by mass or more and 2.0% by mass or less, the boron (B) content is 0% by mass or more and 0.01% by mass or less, and cobalt. The content of (Co) is 0% by mass or more and 0.01% by mass or less, the electroless nickel plating layer is a non-heat-treated layer, and the electroless nickel plating layer contains Ni crystallites. The crystallite diameter of the crystallites measured by the linear diffraction method is 8 to 11 nm.

In the present embodiment, precipitation is formed using a electroless plating bath containing a nickel salt such as nickel sulfate or nickel chloride as a nickel ion supply source and a phosphorus compound such as sodium hypophosphite as a reducing agent. The ratio of the nickel salt and the phosphorus compound in the plating bath is appropriately adjusted according to the composition of the plating film. The plating bath contains a stabilizer for preventing decomposition of the plating solution and suppressing precipitation of the plating, a pH adjuster such as sodium hydroxide and aqueous ammonia, a complexing agent containing an organic acid such as sodium acetate and sodium citrate, and citrate. A buffer such as sodium citrate can be added. The plating film can be formed by immersing the surface to be plated of the base material in a plating bath for a certain period of time. The temperature of the plating bath is determined in consideration of the stability of the bath, the deposition rate, and the like, but it is appropriate to set the temperature in the range of, for example, 60 to 95 ° C, preferably 70 to 90 ° C. Further, the film thickness of the plating film can be appropriately adjusted by adjusting the immersion time in the plating bath.

The phosphorus (P) content of the electroless nickel-plated layer is 1.0% by mass or more and 2.0% by mass or less. Generally, a nickel-plated film having a phosphorus content of 8 to 10% by mass belongs to the "medium phosphorus" type, and a nickel-plated film having a phosphorus content of 10 to 11% by mass belongs to the "medium-high phosphorus" type. Belongs. Nickel plating films with a phosphorus content of 8 to 11% by mass, including these types, are excellent in ease of use of the plating bath, high precipitation rate of the plating film, and good adhesion of the film. It is said to be highly versatile. In the present embodiment, the phosphorus (P) content is 1.0% by mass or more and 2.0% by mass or less, and the "low phosphorus" type is compared with the above "medium phosphorus" type and "medium high phosphorus" type. It belongs to the plating film. If the phosphorus (P) content is less than 1.0% by mass, the electroless nickel plating layer cannot be formed or the film forming rate becomes slow. When the phosphorus (P) content exceeds 2.0% by mass, the desired Ni crystallites cannot be obtained. Due to the characteristics of the plating solution for forming the "low phosphorus" type nickel plating layer, it is difficult for Ni particles to be generated, and it is possible to remove the post-process for removing the Ni particles.

The content of boron (B) in the electroless nickel plating layer is 0% by mass or more and 0.01% by mass or less, and it is preferable that boron (B) is not contained. It is preferable that the plating solution does not contain a boron component substantially. Since boron is not blended, the plating solution can be inexpensive.

The content of cobalt (Co) in the electroless nickel-plated layer is 0% by mass or more and 0.01% by mass or less, and it is preferable that cobalt (Co) is not contained. It is preferable that the plating solution does not contain a cobalt component substantially. Since the cobalt component is not blended, the plating solution can be inexpensive.

The electroless nickel plating layer is a non-heat treatment layer. By using the non-heat-treated layer, the toughness of the plating layer can be increased, and the hardness of the base material does not decrease.

The electroless nickel-plated layer contains Ni crystals, and the crystallite diameter of the crystals measured by the X-ray diffraction method is 8 to 11 nm. By setting the crystallite size in this range, necessary and sufficient hardness can be obtained without heat treatment. That is, the Vickers hardness of the electroless nickel plating layer can be set to 650 Hv or more and 750 Hv or less. The upper limit of the Vickers hardness of the electroless nickel-plated layer may be 700 Hv. If the crystallite diameter of the crystallite is less than 8 nm, the plating film does not have a high hardness, and for example, the Vickers hardness falls below 650 Hv. When the crystallite diameter of the crystallite exceeds 11 nm, the film forming rate becomes slow and it is difficult to form a film.

The electroless nickel plating layer is preferably a non-dispersion type plating film in which ceramic fine particles are not dispersed in the layer. A dispersed plating film in which ceramic fine particles are dispersed in a layer can obtain high hardness. However, since the scratch strength tends to be weak, in the present embodiment, it is preferable to satisfy the hardness and the scratch strength without using the effect of the composite. Further, since the plating layer does not contain ceramic fine particles, there is no attack on the mating member when sliding.

The electroless nickel plating layer is preferably a barrel plating layer. By combining with the barrel plating method, the accumulation of Ni particles is prevented and the smoothness of the member is improved.

The sliding member for a compressor according to the present embodiment has a base layer between a base material and an electroless nickel plating layer, and the base layer contains 6.0 to 11.0% by mass of phosphorus (P). It is preferably an electroless nickel-plated layer and a non-heat-treated layer. By providing a medium to medium to high phosphorus type electroless nickel plating layer as the base layer, the adhesion to the base material can be improved and the smoothness of the plating film can be improved. Further, by providing the base layer, it is possible to suppress the generation of Ni particles and omit the step of removing the Ni particles. The phosphorus (P) in the base layer is preferably 6.5 to 10.5% by mass, and more preferably 7.0 to 10.0% by mass. The most stable film-forming reactivity and smoothness of electroless nickel plating can be obtained in the range of 6.0 to 11.0% by mass of phosphorus (P) in the base layer. On the other hand, if it is less than 6.0% by mass or more than 11.0% by mass, abnormal grain growth or the like is likely to occur due to a decrease in reactivity or an increase in side reactions, and there is a problem such as a decrease in smoothness. The base layer is a non-heat-treated layer. By using the non-heat-treated layer, the toughness of the plating layer can be increased, and the hardness of the base material does not decrease.

The underlying layer preferably does not contain boron (B) and cobalt (Co). Similar to the electroless nickel plating layer, the plating solution for the base layer can be inexpensive.

In the sliding member for a compressor according to the present embodiment, the film thickness of the electroless nickel plating layer formed on the surface of the base material is preferably 15 to 30 μm, more preferably 18 to 25 μm. By setting the film thickness to 15 to 30 μm, it is possible to satisfy the substantial hardness for wear resistance and the toughness against impact. If the film thickness is less than 15 μm, both hardness and toughness may not be satisfied, and if the film thickness exceeds 30 μm, the film may be easily peeled off and the productivity may be lowered.

In the sliding member for a compressor according to the present embodiment, the total film thickness of the base layer and the electroless nickel plating layer formed on the surface of the base material is preferably 15 to 30 μm, preferably 18 to 25 μm. Is more preferable. By setting the total film thickness to 15 to 30 μm, the hardness for wear resistance and the toughness against impact can be satisfied. If the total film thickness is less than 15 μm, both hardness and toughness may not be satisfied, and if the total film thickness exceeds 30 μm, the film may be easily peeled off, and productivity and economy are reduced. There is a risk of The base layer formed on the surface of the base material is preferably 1 to 15 μm, more preferably 3 to 10 μm. The electroless nickel-plated layer formed on the base layer is preferably 15 to 25 μm.

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

The samples shown in Samples 1 to 9 were prepared. A vane made of a high silicon aluminum alloy (Al-10.5 to 20% by mass Si) was immersed in the plating bath shown in Table 1 to form an electroless nickel plating layer, and then washed with water. The film thickness was adjusted by the immersion time so as to have the film thickness shown in Table 1. When forming a plating film having a base layer, first, the vane was immersed in a plating bath for a base layer to form a base layer, and then washed with water. Further, it was immersed in a plating bath for an electroless nickel plating layer to form an electroless nickel plating layer on the base layer, and then washed with water.

Table 1 shows the results of Samples 1-9.

[Layer composition]
The compositions of the electroless nickel plating layer and the base layer were determined by fluorescent X-ray analysis.
[Crystalline diameter]
The nickel crystallite diameter of the electroless nickel plating layer was determined by an X-ray diffraction method.
[Film thickness]
The film thickness was determined by measuring from the cut surface by magnified observation using an optical microscope.
[Hardness]
The hardness of the electroless nickel plating layer or the hardness of the electroless nickel plating layer having the underlying layer was determined by a Micro Vickers hardness tester (JIS Z 2244-2009).
[Scratch strength]
A scratch test was performed on the electroless nickel-plated layer or the electroless nickel-plated layer having a base layer. For the scratch test, a load-variable friction and wear system HHS3000 manufactured by Shinto Kagaku Co., Ltd. was used, and an indenter having a conical diamond tip with an apex angle of 120 ° and a radius of curvature of 0.2 mm was used as a measuring indenter. The load at the position where cracks were first confirmed in the scratch marks formed by sweeping the surface of the plating film in the vertical direction while gradually increasing the range of length of 10 mm from 0N to 98N was obtained from the sweep distance. The scratch strength was used.

FIG. 1 shows the relationship between the phosphorus content of the electroless nickel plating layer and the crystallite diameter of nickel. FIG. 2 shows the relationship between the nickel crystallite diameter and the hardness of the electroless nickel plating layer. FIG. 3 shows the relationship between the nickel crystallite diameter of the electroless nickel plating layer and the scratch strength.

As shown in FIG. 1, all of the samples of the examples have nickel crystallite diameters in the range of 8 to 11 nm. As shown in FIG. 2, in all the examples in which the nickel crystallite diameter was in the range of 8 to 11 nm, the Vickers hardness was 650 Hv or more. In FIG. 2, the Vickers hardness of Comparative Example (Sample No. 7) in which the nickel crystallite diameter is 5.1 nm is 692 Hv, but the high hardness is obtained by dispersing the ceramic particles in the electroless nickel plating layer. This is because of the combined effect of making it. In the comparative examples other than sample number 7, the ceramic particles were not dispersed, and the Vickers hardness was less than 650 Hv. As shown in FIG. 3, in each of the examples in which the nickel crystallite diameter was in the range of 8 to 11 nm, the scratch strength was 98 N or more. In FIG. 3, the scratch strength of Comparative Example (Sample No. 7) in which the nickel crystallite diameter was 5.1 nm was as small as 18.0 N. In the comparative example of sample number 7, as shown in FIG. 2, the Vickers hardness was high, but the scratch strength was low, and both could not be compatible.

In the examples, the adhesion of Ni particles was suppressed.

1 Cam ring 1a Flange part 2 Drive shaft 3 Rotor 4 Vane groove 5 Vane 6 Rear side member 7 Shell members 6a, 7a Side block parts 6b, 7b Head part 8 Suction port 9 Low pressure chamber 10 Discharge port 11 High pressure chamber 11a First high pressure chamber 11b 2nd high pressure chamber 12 Compression space 13 Compression chamber 15 Discharge valve accommodation chamber 17 Through hole

Claims (7)

In a sliding member for a compressor in which an electroless nickel plating layer containing phosphorus is formed on the surface of a base material made of an aluminum alloy.
The phosphorus (P) content of the electroless nickel plating layer is 1.08 % by mass or more and 1.89 % by mass or less, and the boron (B) content is 0% by mass or more and 0.01% by mass or less. Moreover, the content of cobalt (Co) is 0% by mass or more and 0.01% by mass or less.
The electroless nickel plating layer is a non-heat treatment layer.
The electroless nickel plating layer includes a crystallite of Ni, crystallite diameter of the crystallite measured by X-ray diffractometry Ri 8~11nm der,
The Vickers hardness of the electroless nickel-plated layer is 652 Hv or more and 750 Hv or less.
A sliding member for a compressor , wherein the electroless nickel-plated layer has a scratch strength of 98 N or more. The sliding member for a compressor according to claim 1 , wherein the electroless nickel-plated layer does not contain boron (B) and cobalt (Co). The sliding member for a compressor according to claim 1 or 2 , wherein the electroless nickel-plated layer is a barrel-plated layer. An underlayer is provided between the base material and the electroless nickel plating layer.
Any one of claims 1 to 3 , wherein the base layer is an electroless nickel-plated layer containing 6.0 to 11.0% by mass of phosphorus (P) and is a non-heat-treated layer. The sliding member for a compressor described in 1. The sliding member for a compressor according to claim 4 , wherein the base layer does not contain boron (B) and cobalt (Co). The film thickness of the electroless nickel plating layer formed on the surface of the base material, or the total film thickness of the base layer and the electroless nickel plating layer formed on the surface of the base material is 15 to 30 μm. The sliding member for a compressor according to any one of claims 1 to 5 , wherein the sliding member for a compressor is characterized by the above. The sliding member for a compressor according to any one of claims 1 to 6 , wherein the electroless nickel plating layer is a non-dispersion type plating film in which ceramic fine particles are not dispersed in the layer.

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