WO2024070280A1

WO2024070280A1 - Method for manufacturing vane, vane, compressor equipped with vane, and refrigeration cycle device

Info

Publication number: WO2024070280A1
Application number: PCT/JP2023/029337
Authority: WO
Inventors: 崇洋佐々木; 泰幸泉; 基信古川
Original assignee: 株式会社富士通ゼネラル
Priority date: 2022-09-29
Filing date: 2023-08-10
Publication date: 2024-04-04
Also published as: JP2024049585A

Abstract

The present invention provides a method for manufacturing a vane to be used in a compressor comprising a cylinder, a piston orbiting along the inner circumference of the cylinder, and end plates sealing both ends of the cylinder, the vane being provided in a vane groove of the cylinder so that a cylinder chamber formed between the cylinder and the piston is divided into an intake chamber and a compression chamber, the method comprising: forming, from a base material with a Cr content exceeding 4.5 wt%, a vane (127) having a tip surface (129a) to slide against the outer circumference of the piston; forming a high hardness coating layer (211) on at least the tip surface (129a) of the vane (127); and nitriding the vane (127) after the formation of the high hardness coating layer (211).

Description

Method for manufacturing vane, vane, compressor including vane, and refrigeration cycle device

The present invention relates to a method for manufacturing vanes, vanes, and compressors and refrigeration cycle devices equipped with vanes.

The compression section of a rotary compressor includes a cylinder, a piston that revolves along the inner periphery of the cylinder, and end plates that close both ends of the cylinder. Some rotary compressors have vanes in the vane grooves of the cylinder that divide the cylinder chamber, which is formed between the inner periphery of the cylinder and the outer periphery of the piston, into a suction chamber and a compression chamber.

The outer peripheral surface of this type of vane has a tip surface that slides against the outer peripheral surface of the piston, a side surface that slides against the inner surface of the vane groove, and an end surface that slides against the end plate. Therefore, the vane is required to have wear resistance so that it does not wear out even when it slides repeatedly, and seizure resistance so that it does not deteriorate even if it is overheated by frictional heat caused by sliding. In particular, the tip surface of the vane is required to have high hardness (wear resistance) so that it can withstand the large surface pressure when it slides against the piston.

JP 2013-155749 A Japanese Patent Application Laid-Open No. 60-26195 Japanese Patent Application Laid-Open No. 11-280648

In Patent Document 1, a vane formed from high-speed steel as a base material is nitrided to form a nitrided diffusion layer over the entire surface of the vane, and then a DLC (diamond-like carbon) layer is formed as a high-hardness coating layer over the entire nitrided diffusion layer. High-speed steel itself is a steel material with a low Cr content (for example, a Cr content of about 3.8 [wt%] to 4.5 [wt%]), and nitriding the vane alone does not provide sufficient wear resistance and seizure resistance. Therefore, a high-hardness coating layer is further formed over the entire surface of the vane to ensure wear resistance and seizure resistance. However, when a high-hardness coating layer is formed over the entire surface of the vane as in Patent Document 1, the multiple vanes to be treated are placed in the treatment furnace at a distance from each other in order to properly attach the particles that form the high-hardness coating layer to the vane surface. This reduces the number of vanes that can be coated at one time, which increases the manufacturing cost of the vanes.

On the other hand, a prior art is also known that discloses a vane made of a steel material with a high Cr content as a base material (Patent Document 2). In Patent Document 2, a vane made of a steel material with a high Cr content as a base material is nitrided to form a nitride diffusion layer on the surface of the vane, ensuring wear resistance and seizure resistance. However, while the vane described in Patent Document 2 has sufficient wear resistance and seizure resistance on the side and end faces, the hardness of the tip face that receives a large surface pressure from the piston is insufficient, and there is a risk of wear on the tip face progressing. In addition, in such a vane, by nitriding the steel material with a high Cr content, a hard and brittle nitride compound layer, a so-called white layer, is formed thickly on the nitride diffusion layer formed on the surface of the vane. For this reason, even if a high-hardness coating layer is formed to further increase the hardness of the vane, there is a risk that the high-hardness coating layer will peel off along with the nitride compound layer, and there is a problem of poor adhesion of the high-hardness coating layer.

Patent Document 3 describes a technique for improving adhesion between a vane having a nitride compound layer formed on its surface by nitriding and a high-hardness coating layer. In Patent Document 3, after nitriding the vane, ions of the constituent molecules of the high-hardness coating layer are irradiated onto the vane before the high-hardness coating layer is formed. This forms a mixed layer on the surface of the vane in which the constituent molecules of the high-hardness coating layer and the constituent molecules of the vane's base material are bonded. Then, by forming a high-hardness coating layer on the mixed layer, it is possible to improve adhesion between the vane having the nitride compound layer formed and the high-hardness coating layer. However, adding a special process for forming a mixed layer as in Patent Document 3 poses the problem of increased manufacturing costs for the vane.

The disclosed technology has been developed in consideration of the above, and aims to provide a vane manufacturing method that ensures the necessary wear resistance and seizure resistance for the tip, side, and end faces of the vane, while reducing the manufacturing costs of the vane, as well as a vane, and a compressor and refrigeration cycle device that include the vane.

One aspect of the method for manufacturing a vane disclosed in this application is a method for manufacturing a vane that is used in a compressor having a cylinder, a piston that revolves along the inner circumferential surface of the cylinder, and end plates that close both ends of the cylinder, and is provided in a vane groove of the cylinder so as to divide the cylinder chamber formed between the cylinder and the piston into a suction chamber and a compression chamber, in which a vane having a tip surface that slides against the outer circumferential surface of the piston is formed from a base material with a Cr content exceeding 4.5 wt %, a high-hardness coating layer is formed on at least the tip surface of the vane, and the vane is subjected to a nitriding treatment after the high-hardness coating layer is formed.

According to one aspect of the vane manufacturing method disclosed in this application, it is possible to ensure the necessary wear resistance and seizure resistance for the tip surface, side surface, and end surface of the vane, while reducing the manufacturing costs of the vane.

FIG. 1 is a vertical cross-sectional view showing a compressor equipped with a vane of an embodiment. FIG. 2 is an exploded perspective view showing a compression section of the compressor of the embodiment. FIG. 3 is a perspective view showing a vane according to the embodiment. FIG. 4 is a cross-sectional view showing a high-hardness coating layer and a nitride diffusion layer of a vane according to an embodiment of the present invention. FIG. 5 is an enlarged cross-sectional view showing the tip of the vane of the embodiment. FIG. 6 is a schematic diagram for explaining a manufacturing method of the vane of the embodiment. FIG. 7 is a flow chart for explaining a manufacturing method of the vane of the embodiment. FIG. 8 is a schematic diagram for explaining an example of a process for forming a high-hardness coating layer in the embodiment. FIG. 9 is a schematic diagram for explaining another example of the process for forming a high-hardness coating layer in the embodiment. FIG. 10 is a schematic diagram showing a refrigeration cycle device including the compressor of the embodiment.

Below, the manufacturing method of the vane and examples of the vane disclosed in the present application are explained in detail with reference to the drawings. Note that the manufacturing method of the vane and the vane disclosed in the present application are not limited to the following examples.

(Compressor configuration)
Fig. 1 is a vertical cross-sectional view showing a compressor equipped with a vane of the embodiment. As shown in Fig. 1, the compressor 1 is a rotary compressor that accommodates a compression section 12 that draws in a refrigerant from an accumulator 25 and compresses the refrigerant and discharges it into the main container 10, and a motor 11 that drives the compression section 12, inside a main container 10, and discharges the high-pressure refrigerant compressed by the compression section 12 into the main container 10 and further into a refrigeration cycle through a discharge pipe 107. The compressor 1 also includes a rotating shaft 15 that transmits the driving force of the motor 11 to the compression section 12, and an accumulator 25 fixed to the outer circumferential surface of the main container 10.

The main container 10 is provided with an upper compression section suction pipe 102T and a lower compression section suction pipe 102S that penetrate the main container 10 to draw low-pressure refrigerant from the refrigeration cycle into the compression section 12. In more detail, the upper guide pipe 101T is fixed to the main container 10, for example, by brazing, and the upper compression section suction pipe 102T passes through the inside of the upper guide pipe 101T and is fixed to the upper guide pipe 101T, for example, by brazing. Similarly, the lower guide pipe 101S is fixed to the main container 10, for example, by brazing, and the lower compression section suction pipe 102S passes through the inside of the lower guide pipe 101S and is fixed to the lower guide pipe 101S, for example, by brazing.

A discharge pipe 107 for discharging the high-pressure refrigerant compressed in the compression section 12 from inside the main container 10 to the refrigeration cycle is provided through the upper part of the main container 10. A base member 310 that supports the entire compressor 1 is fixed to the lower part of the main container 10 by welding.

The accumulator 25 includes an accumulator suction pipe 27 that draws refrigerant from the refrigeration cycle into the accumulator 25, and an upper gas-liquid separation pipe 31T and a lower gas-liquid separation pipe 31S for sending the gaseous refrigerant to the compression section 12. The accumulator suction pipe 27 is connected to the upper part of the accumulator 25. The upper gas-liquid separation pipe 31T is connected to the upper compression section suction pipe 102T via the upper connecting pipe 104T. The lower gas-liquid separation pipe 31S is connected to the lower compression section suction pipe 102S via the lower connecting pipe 104S.

2 is an exploded perspective view showing the compression section 12 of the compressor 1 of the embodiment. As shown in FIGS. 1 and 2, the compression section 12 has an upper cylinder 121T, a lower cylinder 121S, an intermediate partition plate 140, an upper end plate 160T, and a lower end plate 160S, and is stacked in the order of the upper end plate 160T, the upper cylinder 121T, the intermediate partition plate 140, the lower cylinder 121S, and the lower end plate 160S, and is fixed by a plurality of bolts 175. The upper end plate 160T is provided with a main bearing portion 161T. The lower end plate 160S is provided with a sub-bearing portion 161S. The rotating shaft 15 is provided with a main shaft portion 153, an upper eccentric portion 152T, a lower eccentric portion 152S, and a sub-shaft portion 151. The rotating shaft 15 has a main shaft portion 153 and a sub-shaft portion 151 supported by the compression section 12. The main shaft portion 153 of the rotating shaft 15 is fitted into the main bearing portion 161T of the upper end plate 160T, and the sub-shaft portion 151 of the rotating shaft 15 is fitted into the sub-bearing portion 161S of the lower end plate 160S, so that the rotating shaft 15 is rotatably supported by the main bearing portion 161T and the sub-bearing portion 161S.

The motor 11 has a stator 111 arranged on the outside and a rotor 112 arranged on the inside. The stator 111 is fixed to the inner circumferential surface 10a of the main container 10 by, for example, shrink fitting or welding. The rotor 112 is fixed to the rotating shaft 15 by shrink fitting.

The inside of the main container 10 is filled with lubricating oil 18, enough to almost completely immerse the compression section 12, to lubricate the sliding members of the compression section 12 and to seal between the high-pressure and low-pressure sections in the cylinder chamber.

Next, the compression section 12 will be described in detail with reference to Figure 2. The upper cylinder 121T has a cylindrical upper hollow section 130T formed therein, and an upper piston 125T is disposed in the upper hollow section 130T. The upper piston 125T is fitted into the upper eccentric section 152T of the rotating shaft 15. The lower cylinder 121S has a cylindrical lower hollow section 130S formed therein, and a lower piston 125S is disposed in the lower hollow section 130S. The lower piston 125S is fitted into the lower eccentric section 152S of the rotating shaft 15.

The upper cylinder 121T is provided with an upper vane groove 128T extending from the upper hollow portion 130T to the outer periphery, and an upper vane 127T is disposed in the upper vane groove 128T. The upper cylinder 121T is provided with an upper spring hole 124T that leads from the outer periphery to the upper vane groove 128T, and an upper spring 126T is disposed in the upper spring hole 124T. The lower cylinder 121S is provided with a lower vane groove 128S that extends from the lower hollow portion 130S to the outer periphery, and a lower vane 127S is disposed in the lower vane groove 128S. The lower cylinder 121S is provided with a lower spring hole 124S that leads from the outer periphery to the lower vane groove 128S, and a lower spring 126S is disposed in the lower spring hole 124S.

When one end of the upper vane 127T is pressed against the upper piston 125T by the upper spring 126T, the space outside the upper piston 125T in the upper hollow portion 130T of the upper cylinder 121T is divided into an upper suction chamber 131T and an upper compression chamber 133T, which are upper cylinder chambers. The upper cylinder 121T has an upper suction hole 135T that communicates with the upper suction chamber 131T from the outer periphery. The upper suction hole 135T is connected to the upper compression section suction pipe 102T. When one end of the lower vane 127S is pressed against the lower piston 125S by the lower spring 126S, the space outside the lower piston 125S in the lower hollow portion 130S of the lower cylinder 121S is divided into a lower suction chamber 131S and a lower compression chamber 133S, which are lower cylinder chambers. The lower cylinder 121S has a lower suction hole 135S that communicates with the lower suction chamber 131S from the outer periphery. The lower compression section suction pipe 102S is connected to the lower suction hole 135S.

The upper end plate 160T is provided with an upper discharge hole 190T that penetrates the upper end plate 160T and communicates with the upper compression chamber 133T. An upper discharge valve 200T, which is a reed valve that opens and closes the upper discharge hole 190T, and an upper discharge valve retainer 201T that regulates the warping of the upper discharge valve 200T are fixed to the upper end plate 160T by an upper rivet 202T. An upper end plate cover 170T that covers the upper discharge hole 190T is disposed on the upper side of the upper end plate 160T, and an upper end plate cover chamber 180T that is closed by the upper end plate 160T and the upper end plate cover 170T is formed. The upper end plate cover 170T is fixed to the upper end plate 160T by a plurality of bolts 175 that fix the upper end plate 160T to the upper cylinder 121T. The upper end plate cover 170T is provided with an upper end plate cover discharge hole 172 that communicates between the upper end plate cover chamber 180T and the inside of the main container 10. When the compression section 12 is provided in the main container 10, the inner peripheral surface 10a of the main container 10 is shrink-fitted to the outer peripheral surface 182a of the upper end plate 160T and is joined to the main container 10 by a plurality of welds V (FIG. 4). The structure of the upper end plate 160T in this embodiment will be described in detail later.

The lower end plate 160S is provided with a lower discharge hole 190S that penetrates the lower end plate 160S and communicates with the lower compression chamber 133S. A lower discharge valve 200S, which is a reed valve that opens and closes the lower discharge hole 190S, and a lower discharge valve holder 201S that regulates the warping of the lower discharge valve 200S are fixed to the lower end plate 160S by a lower rivet 202S. A lower end plate cover 170S that covers the lower discharge hole 190S is arranged below the lower end plate 160S, forming a lower end plate cover chamber 180S that is closed by the lower end plate 160S and the lower end plate cover 170S (see Figure 1). The lower end plate cover 170S is fixed to the lower end plate 160S by a plurality of bolts 175 that fix the lower end plate 160S and the lower cylinder 121S.

The compression section 12 also has a refrigerant passage hole 136 (see FIG. 2) that penetrates the lower end plate 160S, the lower cylinder 121S, the intermediate partition plate 140, the upper end plate 160T, and the upper cylinder 121T and connects the lower end plate cover chamber 180S and the upper end plate cover chamber 180T.

The flow of refrigerant caused by the rotation of the rotating shaft 15 will be explained below. As the rotating shaft 15 rotates, the upper piston 125T fitted into the upper eccentric portion 152T of the rotating shaft 15 and the lower piston 125S fitted into the lower eccentric portion 152S revolve, causing the upper suction chamber 131T and the lower suction chamber 131S to expand in volume while drawing in refrigerant. As a refrigerant intake path, low-pressure refrigerant from the refrigeration cycle is drawn into the accumulator 25 through the accumulator suction pipe 27, and only gaseous refrigerant is drawn into the upper gas-liquid separation pipe 31T and the lower gas-liquid separation pipe 31S. The gaseous refrigerant drawn into the upper gas-liquid separation pipe 31T is drawn into the upper suction chamber 131T through the upper connecting pipe 104T and the upper compression section suction pipe 102T. Similarly, the gas refrigerant drawn into the lower gas-liquid separation pipe 31S passes through the lower connecting pipe 104S and the lower compression section suction pipe 102S and is drawn into the lower suction chamber 131S.

Next, the flow of the discharged refrigerant caused by the rotation of the rotating shaft 15 will be explained. As the rotating shaft 15 rotates, the upper piston 125T fitted to the upper eccentric portion 152T of the rotating shaft 15 revolves, compressing the refrigerant while reducing the volume of the upper compression chamber 133T. When the pressure of the compressed refrigerant becomes higher than the pressure in the upper end plate cover chamber 180T outside the upper discharge valve 200T, the upper discharge valve 200T opens and discharges the refrigerant from the upper compression chamber 133T to the upper end plate cover chamber 180T. The refrigerant discharged into the upper end plate cover chamber 180T is discharged into the main container 10 from the upper end plate cover discharge hole 172 provided in the upper end plate cover 170T.

Also, as the rotating shaft 15 rotates, the lower piston 125S fitted into the lower eccentric portion 152S of the rotating shaft 15 revolves, compressing the refrigerant while reducing the volume of the lower compression chamber 133S. When the pressure of the compressed refrigerant becomes higher than the pressure in the lower end plate cover chamber 180S outside the lower discharge valve 200S, the lower discharge valve 200S opens and discharges the refrigerant from the lower compression chamber 133S to the lower end plate cover chamber 180S. The refrigerant discharged into the lower end plate cover chamber 180S passes through the refrigerant passage hole 136 and the upper end plate cover chamber 180T and is discharged into the main body container 10 from the upper end plate cover discharge hole 172T provided in the upper end plate cover 170T.

The refrigerant discharged into the main container 10 is guided above the motor 11 through a notch (not shown) on the outer periphery of the stator 111 that connects the top and bottom, or through a gap in the winding part of the stator 111 (not shown), or through the gap 115 between the stator 111 and the rotor 112 (see Figure 1), and is discharged from the discharge pipe 107 located at the top of the main container 10.

Next, the flow of the lubricating oil 18 will be explained. The lubricating oil 18 sealed in the lower part of the main container 10 is supplied to the compression section 12 through the inside of the rotating shaft 15 (not shown) by the centrifugal force of the rotating shaft 15. The lubricating oil 18 supplied to the compression section 12 is mixed with the refrigerant and is discharged into the inside of the main container 10 together with the refrigerant in a mist form. The mist of the lubricating oil 18 discharged into the inside of the main container 10 is separated from the refrigerant by the centrifugal force of the rotational force of the motor 11, and returns to the bottom of the main container 10 as oil droplets. However, some of the lubricating oil 18 is not separated and is discharged into the refrigerant together with the refrigerant into the refrigeration cycle. The lubricating oil 18 discharged into the refrigeration cycle circulates through the refrigeration cycle and returns to the accumulator 25, where it is separated inside the accumulator 25 and accumulates in the lower part of the accumulator 25. The lubricating oil 18 accumulated in the lower part of the accumulator 25 is sucked into the upper suction chamber 131T and the lower suction chamber 131S together with the suctioned refrigerant.

(Characteristic configuration of the compressor)
Next, a characteristic configuration of the compressor 1 of the embodiment will be described. The characteristics of the embodiment include a high-hardness coating layer 211 and a nitride diffusion layer 212 formed on the surfaces of the upper vane 127T and the lower vane 127S (hereinafter also referred to as vane 127). Since the upper vane 127T and the lower vane 127S have the same structure, the upper vane 127T will be described below, and a description of the lower vane 127S will be omitted.

Figure 3 is a perspective view showing the vane of the embodiment. As shown in Figure 3, the upper vane 127T has a tip surface 129a that slides against the outer circumferential surface of the upper piston 125T, and a first side surface 129b and a second side surface 129c that slide against the inner surface of the upper vane groove 128T. The upper vane 127T also has a first end surface 129d that slides against the end surface of the upper end plate 160T, a second end surface 129e that slides against the end surface of the intermediate partition plate 140 as an end plate, and a back surface 129f that is pressed by the upper spring 126T. In addition, regarding the lower vane 127S, the lower vane 127S has a first end surface 129d that slides against the end surface of the intermediate partition plate 140 as an end plate, and a second end surface 129e that slides against the end surface of the lower end plate 160S.

The upper vane 127T is formed from a base material that is an iron-based metal material, and the first side surface 129b, the second side surface 129c, the first end surface 129d, and the second end surface 129e are each formed in a flat plate shape. In the embodiment, the upper vane 127T is formed from a base material with a Cr (chromium) content of more than 4.5 [wt%]. Examples of base materials that can be used include SUS440C (a type of stainless steel) with a Cr content of about 16 [wt%] to 18 [wt%], SKD61 (a type of die steel) with a Cr content of about 4.8 [wt%] to 5.5 [wt%], and SKD11 (a type of die steel) with a Cr content of about 11.0 [wt%] to 13.0 [wt%].

In this way, the upper vane 127T is formed from a base material with a Cr content exceeding 4.5 wt% to ensure adequate wear resistance and seizure resistance. Furthermore, when the upper vane 127T is formed from stainless steel with a Cr content exceeding 10 wt%, the wear resistance and seizure resistance of the first side surface 129b and the second side surface 129c, which have a particularly large sliding area, can be sufficiently ensured.

The tip surface 129a of the upper vane 127T is formed in an arc shape when viewed from a direction perpendicular to the first end surface 129d and the second end surface 129e. The back surface 129f of the upper vane 127T has an engagement portion 138 with which the end of the upper spring 126T engages, which is formed by cutting out a part of the flat back surface 129f.

FIG. 4 is a cross-sectional view showing the high-hardness coating layer and nitride diffusion layer of the vane 127 of the embodiment. FIG. 4 is a cross-sectional view perpendicular to the first end face 129d and the second end face 129e of the vane 127. FIG. 5 is a cross-sectional view showing an enlarged tip portion of the vane 127 of the embodiment. FIG. 5 is a cross-sectional view perpendicular to the first side face 129b and the second side face 129c of the vane 127.

As shown in FIG. 4, a high-hardness coating layer 211 is formed on the tip surface 129a of the upper vane 127T. In addition, a nitride diffusion layer 212 is formed on the outer peripheral surface of the upper vane 127T by nitriding treatment on the entire first side surface 129b and the second side surface 129c, the entire first end surface 129d and the entire second end surface 129e, the entire back surface 129f, and the entire surface 138a of the engagement portion 138, except for the outer peripheral edge portion of the tip surface 129a (for example, the portion of the tip surface 129a adjacent to each of the first side surface 129b, the second side surface 129c, the first end surface 129d, and the second end surface 129e). A nitride compound layer 213, a so-called white layer, is formed on the nitride diffusion layer 212. The nitride compound layer 213 may be cut to a predetermined thickness or less in order to ensure the dimensional accuracy and surface accuracy of the nitrided upper vane 127T. In addition, the nitride compound layer 213 may be completely removed from above the nitride diffusion layer 212, exposing the nitride diffusion layer 212 on the outer surface of the upper vane 127T, thereby preventing wear of the porous nitride compound layer 213.

As shown in FIG. 5, a high-hardness coating layer 211 is formed over the entire tip surface 129a of the upper vane 127T. The high-hardness coating layer 211 is, for example, DLC (diamond-like carbon), CrN (chromium nitride), Cr2N (dichromium nitride), etc. The hardness of the high-hardness coating layer 211 is 1500 [HV] or more, and the wear resistance of the tip surface 129a of the upper vane 127T is appropriately ensured. On the other hand, the hardness of the nitride diffusion layer 212 or the nitride compound layer 213 formed on the first side surface 129b, the second side surface 129c, the first end surface 129d, and the second end surface 129e of the upper vane 127T is desirably 900 [HV] or more.

The manufacturing steps of the upper vane 127T will be described later, but in the embodiment, the upper vane 127T has a nitride diffusion layer 212 formed after the formation of the high-hardness coating layer 211. Therefore, the tip surface 129a of the upper vane 127T has an area A where the nitride diffusion layer 212 is not formed, as shown in Figures 4 and 5.

(Method of manufacturing vanes included in a compressor)
A method for manufacturing the vane 127 included in the compressor 1 configured as above will be described. Fig. 6 is a schematic diagram for explaining the method for manufacturing the vane 127 of the embodiment. Fig. 7 is a flow chart for explaining the method for manufacturing the vane 127 of the embodiment.

As shown in Figures 6 and 7, the vane 127 is formed from a base material with a Cr (chromium) content exceeding 4.5 wt% (step S1). This ensures that the vane 127 has adequate wear resistance and seizure resistance. In this embodiment, for example, the vane 127 is formed from stainless steel with a Cr content of approximately 16 wt% to 18 wt%. By forming the vane 127 from stainless steel with a Cr content exceeding 10 wt%, it is possible to adequately ensure wear resistance and seizure resistance, particularly for the first side surface 129b and the second side surface 129c, which have a large sliding area.

Next, in this embodiment, after the vane 127 is formed, the vane 127 is hardened (step S2) to increase the wear resistance and mechanical strength of the base material. After the vane 127 is hardened, the vane 127 is tempered (step S3) to increase the toughness of the base material.

Next, a high-hardness coating layer 211 is formed on the tip surface 129a of the vane 127 (step S4). The high-hardness coating layer 211 is formed by any of a variety of coatings, such as DLC (diamond-like carbon), CrN (chromium nitride), Cr2N (dichromium nitride), etc. This increases the wear resistance of the tip surface 129a of the vane 127.

The high-hardness coating layer 211 is formed by, for example, vacuum deposition or sputtering. In this embodiment, the high-hardness coating layer 211 is formed only on the tip surface 129a of the vane 127, so that the side surfaces 129b, 129c and

end surfaces

129d, 129e on which the high-hardness coating layer 211 is not formed are brought into contact with each other, and multiple vanes 127 can be arranged and coated. This allows the number of vanes 127 that can be coated at one time to be increased, thereby reducing the manufacturing costs of the vanes 127.

The manufacturing method of the embodiment is not limited to having a process of forming the high-hardness coating layer 211 only on the tip surface 129a of the vane 127. If necessary, in addition to the tip surface 129a of the vane 127, for example, when multiple vanes 127 are coated at once as shown in Figures 8 and 9 described later, the high-hardness coating layer 211 may be formed on any one or more of the four surfaces of the first side surface 129b, the second side surface 129c, the first end surface 129d, and the second end surface 129e. In addition to the tip surface 129a of the vane 127, for example, the high-hardness coating layer 211 may be formed on the parts of the first side surface 129b, the second side surface 129c, the first end surface 129d, and the second end surface 129e adjacent to the tip surface 129a.

Subsequently, after the formation of the high-hardness coating layer 211, the vane 127 is subjected to a nitriding treatment. Examples of nitriding treatment include gas nitriding, gas soft nitriding, and ion nitriding. In the nitriding treatment, nitrogen atoms penetrate and diffuse from the surface of the base material to the inside, forming a nitride diffusion layer 212 and a nitride compound layer 213 near the outer surface of the base material. In the embodiment, the nitriding treatment of the vane 127 forms a nitride diffusion layer 212 on the first side surface 129b and second side surface 129c, the first end surface 129d and second end surface 129e, the back surface 129f, and the surface 138a of the engagement portion 138 of the vane 127, and also forms a nitride compound layer 213 on the outer surface side of the nitride diffusion layer 212.

In this embodiment, before the vane 127 is nitrided, the high-hardness coating layer 211 is formed on the tip surface 129a of the vane 127. Therefore, the high-hardness coating layer 211 is not formed on the nitride compound layer 213 (on the outer surface side) formed on the vane 127, so that the adhesion between the high-hardness coating layer 211 and the tip surface 129a is ensured, and the wear resistance and seizure resistance of the tip surface 129a are improved by the high-hardness coating layer 211. Therefore, there is no need to add a special process such as forming a mixed layer to improve the adhesion of the high-hardness coating layer 211, and the manufacturing cost of the vane 127 can be reduced. In addition, by nitriding the vane 127, the wear resistance and seizure resistance of the first side surface 129b and the second side surface 129c, the first end surface 129d and the second end surface 129e of the vane 127 are ensured.

Finally, the nitride layer 213 of the vane 127 is removed (step S6). In this process, the nitride layer 213 is removed so that the thickness of the nitride layer 213 is a predetermined thickness (e.g., 1 μm) or less. Also, in this process, the nitride layer 213 formed on the first side surface 129b and the second side surface 129c, and the first end surface 129d and the second end surface 129e of the vane 127 are removed. This removes the surface layer with minute bulges and minute recesses that occur on the surface of the vane 127 due to the nitriding process, and makes the first side surface 129b and the second side surface 129c, the first end surface 29d and the second end surface 129e flat, thereby ensuring the dimensional accuracy and surface accuracy (flatness) of the vane 127 that slides against the inner surface of the upper vane groove 128T (lower vane groove 128S), the upper end plate 160T (lower end plate 160S), and the end surface of the intermediate partition plate 140.

In the process of scraping the nitride layer 213, the nitride layer 213 may be scraped until it is completely removed, thereby exposing the nitride diffusion layer 212 to the outside of the vane 127. This makes it possible to prevent the nitride layer 213, which is hard but porous and therefore brittle, from being worn down when sliding under high surface pressure. In the embodiment, the nitride compound layer 213 on the first side surface 129b and the second side surface 129c, the first end surface 129d and the second end surface 129e, the back surface 129f, and the surface 138a of the engagement portion 138 of the vane 127 is removed to expose the nitride diffusion layer 212, but for example, the nitride compound layer 213 on the first side surface 129b and the second side surface 129c, which have a large sliding area, may be completely removed to expose the nitride diffusion layer 212, and the nitride compound layer 213 on the first end surface 129d and the second end surface 129e, the back surface 129f, and the surface 138a of the engagement portion 138 may not be completely removed and may cover the nitride diffusion layer 212.

In addition, from the viewpoint of ensuring the wear resistance of the vane 127, since the hardness of the nitride compound layer 213 is higher than that of the nitride diffusion layer 212, there is no problem even if the nitride compound layer 213 is formed on the nitride diffusion layer 212 of the vane 127. Therefore, the manufacturing method of this embodiment is not limited to having a step of removing the nitride compound layer 213, and the nitride compound layer 213 may be left on the nitride diffusion layer 212. In this case, since there is no need to remove the nitride compound layer 213, the number of steps can be reduced and the manufacturing of the vane 127 can be facilitated.

FIG. 8 is a schematic diagram for explaining an example of the process for forming the high-hardness coating layer 211 in the embodiment. FIG. 9 is a schematic diagram for explaining another example of the process for forming the high-hardness coating layer 211 in the embodiment.

In the forming process of forming the high-hardness coating layer 211 on the tip surface 129a of the vane 127, when forming the high-hardness coating layer 211 on the vane 127, the vanes 127 are arranged so that the opposing surfaces of adjacent vanes 127 are in contact with each other, and the high-hardness coating layer 211 is formed on each tip surface 129a of the vanes 127 at once. This increases the number of vanes 127 on which the high-hardness coating layer 211 can be formed in one forming process, thereby reducing the manufacturing cost of the vane 127. Here, the opposing surfaces of adjacent vanes 127 include the first side surface 129b and the second side surface 129c, the first end surface 129d and the second end surface 129e.

Specifically, as shown in FIG. 8, when multiple vanes 127 are arranged in a processing furnace, the side surfaces 129b, 129c of adjacent vanes 127, i.e., the opposing first side surface 129b and second side surface 129c, are arranged so that they are in contact with each other, thereby forming a high-hardness coating layer 211 on each tip surface 129a of the multiple vanes 127. In this way, by using other vanes 127 as masking members for coating the vanes 127, it is possible to reduce the masking process for the surfaces of the vanes 127 that are not to be coated.

As another example of arranging multiple vanes 127 in a processing furnace, as shown in FIG. 9, adjacent vanes 127 may be arranged so that their respective side faces 129b, 129c, i.e., the opposing first side face 129b and second side face 129c, are in contact with each other, and adjacent vanes 127 may be arranged so that their respective end faces 129d, 129e, i.e., the opposing first end face 129d and second end face 129e, are in contact with each other. This further increases the number of vanes 127 that can form a high-hardness coating layer 211 in a single formation process, and further reduces the manufacturing cost of the vanes 127.

(Configuration of refrigeration cycle device)
Here, a description will be given of an example of a refrigeration cycle device 2 including the compressor 1. Fig. 10 is a schematic diagram showing a refrigeration cycle device 2 including the compressor 1 of the embodiment.

As shown in FIG. 10, the refrigeration cycle device 2 of the embodiment includes a compressor 1 having a main container 10 and an accumulator 26, a condenser (either the first heat exchanger 4 or the second heat exchanger 6) that condenses the refrigerant compressed by the compressor 1, an expansion valve 5 as a pressure reducer that reduces the pressure of the refrigerant condensed by the condenser, an evaporator (the other of the first heat exchanger 4 or the second heat exchanger 6) that evaporates the refrigerant reduced in pressure by the expansion valve 5, and a pipe 7 through which the refrigerant discharged from the compressor 1 circulates.

A four-way valve 8 for switching the flow of the refrigerant is provided in the flow path of the pipe 7 through which the refrigerant discharged from the compressor 1 flows. For example, when the refrigeration cycle device 2 is in cooling operation, the refrigerant circulates as shown by the solid arrows in FIG. 10, the first heat exchanger 4, which is the indoor heat exchanger, corresponds to the condenser, and the second heat exchanger 6, which is the outdoor heat exchanger, corresponds to the evaporator. Note that when the refrigeration cycle device 2 is in heating operation, the refrigerant circulates as shown by the dotted arrows in FIG. 10, the second heat exchanger 6, which is the outdoor heat exchanger, corresponds to the condenser, and the first heat exchanger 4, which is the indoor heat exchanger, corresponds to the evaporator.

(Effects of the embodiment)
As described above, in the manufacturing method of the vane 127 of the embodiment, the upper vane 127T (lower vane 127S) having a tip surface 129a that slides against the outer peripheral surface of the upper piston 125T (lower piston 125S) is formed from a base material having a Cr content exceeding 4.5 [wt %], a high-hardness coating layer 211 is formed on at least the tip surface 129a of the upper vane 127T (lower vane 127S), and after the formation of the high-hardness coating layer 211, the upper vane 127T (lower vane 127S) is subjected to a nitriding treatment. In this way, by forming the high-hardness coating layer 211 on the tip surface 129a of the upper vane 127T (lower vane 127S) before subjecting the upper vane 127T (lower vane 127S) to nitriding treatment, it is possible to prevent the high-hardness coating layer 211 from being formed on the nitride compound layer 213, thereby ensuring adhesion between the high-hardness coating layer 211 and the tip surface 129a, and the wear resistance and seizure resistance of the tip surface 129a are improved by the high-hardness coating layer 211. Therefore, there is no need to add a process for improving the adhesion of the high-hardness coating layer 211, and the manufacturing cost of the upper vane 127T (lower vane 127S) can be reduced. In addition, by nitriding the upper vane 127T (lower vane 127S), the wear resistance and seizure resistance of the first side surface 129b and second side surface 129c, first end surface 129d and second end surface 129e of the upper vane 127T (lower vane 127S) are ensured.

Therefore, according to the manufacturing method of the vane 127 of the embodiment, the wear resistance and seizure resistance required for the tip surface 129a, the first side surface 129b and the second side surface 129c, and the first end surface 129d and the second end surface 129e of the vane 127 are ensured, and the manufacturing cost of the vane 127 is reduced. Also, for example, by forming the high-hardness coating layer 211 only on the tip surface 129a of the vane 127, it becomes possible to arrange multiple vanes 127 and coat them by bringing the side surfaces 129b, 129c and the end surfaces 129d, 129e, on which the high-hardness coating layer 211 is not formed, into contact with each other. This allows the number of vanes 127 that can be coated at one time to be increased, thereby reducing the manufacturing cost of the vane 127.

In addition, the manufacturing method of the vane 127 of the embodiment cuts the nitride compound layer 213 on the nitride diffusion layer 212 formed on the first side 129b and second side 129c, first end face 129d and second end face 129e of the vane 127. This cuts the surface layer of the vane 127 that has been slightly deformed due to the nitriding process, ensuring the dimensional accuracy and surface accuracy of the vane 127 that slides against the inner surface of the upper vane groove 128T (lower vane groove 128S), the upper end plate 160T (lower end plate 160S), and the end face of the intermediate partition plate 140.

In addition, the manufacturing method of the vane 127 of the embodiment exposes the nitride diffusion layer 212 by scraping the nitride layer 213. This removes the nitride layer 213, thereby preventing the nitride layer 213 from peeling off from the vane 127.

In addition, in the manufacturing method of the vane 127 of the embodiment, the vane 217 is quenched and then tempered before forming the high-hardness coating layer 211 on the vane 127. This further increases the wear resistance (hardness) of the base material of the vane 127.

In addition, in the manufacturing method of the vane 127 of the embodiment, when forming the high-hardness coating layer 211 on the vane 127, multiple vanes 127 are arranged so that the opposing surfaces of adjacent vanes 127 are in contact with each other, and the high-hardness coating layer 211 is formed on each tip surface 129a of the multiple vanes 127 at once. This increases the number of vanes 127 on which the high-hardness coating layer 211 can be formed in one formation process, thereby reducing the manufacturing cost of the vane 127. In addition, by using other vanes 127 as masking members for coating the vane 127, the masking process for the surfaces of the vane 127 that are not to be coated can also be reduced.

In addition, the manufacturing method of the vane 127 of the embodiment forms the high-hardness coating layer 211 using either DLC, CrN, or Cr2N. This ensures that the hardness of the high-hardness coating layer 211 is 1500 [HV] or more, so that the wear resistance of the tip surface 129a of the vane 127 can be appropriately ensured.

In addition, the manufacturing method of the vane 127 in the embodiment uses stainless steel as the base material to form the vane 127. As a result, the vane 127 is formed from stainless steel with a Cr content exceeding 10 wt %, so that the wear resistance and seizure resistance of the first side surface 129b and the second side surface 129c, which have a particularly large sliding area, can be sufficiently ensured.

In this embodiment, a two-cylinder rotary compressor having two cylinders 121, an upper cylinder 121T and a lower cylinder 121S, is exemplified as the compressor 1, but a one-cylinder rotary compressor having only one cylinder 121 may also be used.

1 Compressor 2 Refrigeration cycle device 4 First heat exchanger (condenser)
5 Expansion valve (pressure reducer)
6 Second heat exchanger (evaporator)
121T Upper cylinder (cylinder)
121S Lower Cylinder (Cylinder)
125T upper piston (piston)
125S Lower piston (piston)
127 Vane 127T Upper Vane (Vane)
127S Lower vane (vane)
128T Upper vane groove (vane groove)
128S Lower vane groove (vane groove)
129a: tip surface; 129b: first side surface; 129c: second side surface; 129d: first end surface; 129e: second end surface; 129f: rear surface; 131T: upper suction chamber (suction chamber)
131S Lower suction chamber (suction chamber)
133T Upper compression chamber (compression chamber)
133S Lower compression chamber (compression chamber)
140 Intermediate partition plate (end plate)
160T Upper end plate (end plate)
160S Lower end plate (end plate)
211 High-hardness coating layer 212 Nitride diffusion layer 213 Nitride compound layer A region

Claims

A method for manufacturing a vane used in a compressor including a cylinder, a piston that revolves along an inner circumferential surface of the cylinder, and end plates that close both ends of the cylinder, the vane being provided in a vane groove of the cylinder so as to divide a cylinder chamber formed between the cylinder and the piston into a suction chamber and a compression chamber, comprising the steps of:
The vane has a tip surface that slides against an outer circumferential surface of the piston, and is formed from a base material having a Cr content of more than 4.5 [wt%],
forming a high-hardness coating layer on at least the tip surface of the vane;
the vane is subjected to a nitriding treatment after the formation of the high-hardness coating layer.
forming a nitride diffusion layer by the nitriding treatment on the vane having a side surface that slides against the inner surface of the vane groove and an end surface that slides against the end plate;
removing the nitride compound layer on the nitride diffusion layer formed on the side surface and the end surface of the vane;
A method for manufacturing the vane of claim 1 .
The nitride compound layer is removed to expose the nitride diffusion layer.
A method for manufacturing the vane according to claim 2.
Before forming the high hardness coating layer on the vane, the vane is quenched and then tempered.
A method for manufacturing a vane according to any one of claims 1 to 3.
When forming the high-hardness coating layer on the vane, a plurality of the vanes are arranged so that the opposing surfaces of the adjacent vanes are in contact with each other, and the high-hardness coating layer is formed on each tip surface of the plurality of vanes at the same time.
A method for manufacturing the vane of claim 1 .
The high-hardness coating layer is formed using any one of DLC, CrN, and CrN.
A method for manufacturing the vane of claim 1 .
The vane is formed using stainless steel as a base material.
A method for manufacturing the vane of claim 1 .
A vane is used in a compressor including a cylinder, a piston that revolves along an inner circumferential surface of the cylinder, and end plates that close both ends of the cylinder, the vane being provided in a vane groove of the cylinder so as to divide a cylinder chamber formed between the cylinder and the piston into a suction chamber and a compression chamber,
a tip surface that slides against the outer circumferential surface of the piston, a first side surface and a second side surface that slide against each inner surface of the vane groove of the cylinder, and a first end surface and a second end surface that slide against each end plate, the tip surface being formed from a base material having a Cr content of more than 4.5 [wt%];
A high-hardness coating layer is formed at least on the tip surface,
a nitride diffusion layer is formed on at least the first side surface, the second side surface, the first end surface, and the second end surface;
The vane, wherein the tip surface has a region where a nitride diffusion layer is not formed.
the nitride diffusion layer is exposed at the first side surface, the second side surface, the first end surface, and the second end surface;
The vane of claim 8.
The high-hardness coating layer is any one of DLC, CrN, and CrN;
The vane of claim 8.
Formed from stainless steel as the base material,
The vane of claim 8.
The hardness of the high-hardness coating layer is 1500 [HV] or more.
The vane of claim 8.
A compressor comprising the vane according to any one of claims 8 to 12, the cylinder, the piston, and the end plate.
A refrigeration cycle device comprising the compressor according to claim 13, a condenser for condensing the refrigerant compressed by the compressor, a pressure reducer for reducing the pressure of the refrigerant condensed by the condenser, and an evaporator for evaporating the refrigerant reduced in pressure by the pressure reducer.