Method of manufacturing vanes

Abstract

The tip surface of the vane is properly ground. [Solution] The vane manufacturing method is a method for manufacturing a vane 127 having a base material layer 210 made of a base material and a nitrided layer 311 formed by nitriding the material forming the base material layer 210, and includes a step of nitriding the base material layer 210 so that the base material layer 210 is covered with the nitrided layer 311 (step S5), a step of making the lengths of multiple vanes 127 uniform by grinding the back surface 129f of the base material layer 210 on the opposite side of the front surface 129a with respect to the front surface 129a after the step of nitriding the base material layer 210 (step S5) has been performed, and a step of removing the nitrided compound layer 312 from the front surface 129a by grinding the front surface 129a with respect to the back surface 129f with respect to the front surface 129a after the step of grinding the back surface 129f (step S6) has been performed so that the nitrided diffusion layer 313 of the nitrided layer 311 is exposed (step S7).

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a vane.

Background Art

[0002] A rotary compressor including a cylinder, a piston that revolves along the inner peripheral surface of the cylinder, an end plate that closes an end of the cylinder, and a vane that partitions a cylinder chamber surrounded by the cylinder, the piston, and the end plate into a suction chamber and a compression chamber is known (Patent Document 1). After the vane is coated with a nitride layer, the nitride compound layer (white layer) in the nitride layer is removed by grinding the tip surface so that the nitride diffusion layer in the nitride layer is exposed at the tip surface. Such a vane can reduce the number of manufacturing steps and the manufacturing cost by grinding the tip surfaces of a plurality of vanes at once in a state where the plurality of vanes are arranged.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in such a grinding method, when there are variations in the sizes of a plurality of vanes, there are problems such that the base material layer is exposed at the tip surface due to excessive grinding of the tip surface, or the nitride compound layer in the nitride layer remains at the tip surface due to insufficient grinding of the tip surface.

[0005] The disclosed technology has been made in view of such points, and an object thereof is to provide a method for manufacturing a vane that appropriately grinds the tip surface of the vane.

Means for Solving the Problems

[0006] A method for manufacturing a vane according to one aspect of the present disclosure is a method for manufacturing a vane used in a rotary compressor, having a base material layer made of a base material and a nitrided layer formed by nitriding the material forming the base material layer, wherein the nitrided layer includes a nitrided diffusion layer and a nitrided compound layer, and includes the steps of: nitriding the base material layer so that the base material layer is covered by the nitrided layer; after the step of nitriding the base material layer is performed, grinding the back surface of the base material layer opposite to the front surface with respect to the front surface to make the lengths of a plurality of vanes uniform; and after the step of grinding the back surface is performed, grinding the front surface with respect to the back surface so that the nitrided diffusion layer of the nitrided layer is exposed to make the lengths of a plurality of vanes uniform. [Effects of the Invention]

[0007] The vane manufacturing method of this disclosure allows for proper grinding of the vane's tip surface. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a longitudinal cross-sectional view showing a rotary compressor equipped with vanes manufactured by the vane manufacturing method of the embodiment. [Figure 2] Figure 2 is an exploded perspective view showing the compression section. [Figure 3] Figure 3 is a perspective view showing the vane. [Figure 4] Figure 4 is a cross-sectional view showing the tip surface, first side surface, and second side surface of the vane. [Figure 5] Figure 5 is a cross-sectional view showing the tip surface, first end surface, and second end surface of the vane. [Figure 6] Figure 6 is a schematic diagram illustrating the manufacturing method of the vane in the embodiment. [Figure 7] Figure 7 is a cross-sectional view showing the tip surface, first side surface, and second side surface of the vane after nitriding treatment in the vane manufacturing method of the embodiment. [Figure 8] Figure 8 is a perspective view showing multiple length-adjusted vanes in the vane manufacturing method of the embodiment. [Figure 9] Figure 9 is a cross-sectional view showing the tip surface, first side surface, and second side surface of the vane after white layer grinding in the vane manufacturing method of the embodiment. [Figure 10] Figure 10 is a schematic diagram illustrating the vane manufacturing method of a comparative example. [Figure 11] Figure 11 is a cross-sectional view showing the tip surface, first side surface, and second side surface of the vane after adjusting the height for insufficient grinding in the comparative example vane manufacturing method. [Figure 12] Figure 12 is a cross-sectional view showing the tip surface, first side surface, and second side surface of the vane after adjusting the excessive grinding height in the comparative example vane manufacturing method. [Modes for carrying out the invention]

[0009] The method for manufacturing a vane according to the embodiments disclosed herein will be described below with reference to the drawings. However, the technology of this disclosure is not limited by the following description. Furthermore, the same reference numerals are used for identical components, and redundant explanations are omitted. [Examples]

[0010] (Compressor configuration) Figure 1 is a longitudinal cross-sectional view showing a rotary compressor 1 equipped with vanes manufactured by the vane manufacturing method of the embodiment. As shown in Figure 1, the rotary compressor 1 houses a compression unit 12 that draws in refrigerant from an accumulator 25 and discharges the compressed refrigerant into the main body container 10, and a motor 11 that drives the compression unit 12. The high-pressure refrigerant compressed by the compression unit 12 is discharged into the main body container 10 and further discharged to the refrigeration cycle through a discharge pipe 107. The rotary compressor 1 also includes a rotating shaft 15 that transmits the driving force of the motor 11 to the compression unit 12, and an accumulator 25 fixed to the outer circumferential surface of the main body container 10.

[0011] In the main body container 10, an upper compression part suction pipe 102T and a lower compression part suction pipe 102S for sucking the low-pressure refrigerant of the refrigeration cycle into the compression part 12 are provided through the main body container 10. Specifically, an upper guide pipe 101T is fixed to the main body container 10, for example, by brazing, and the upper compression part 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, a lower guide pipe 101S is fixed to the main body container 10, for example, by brazing, and the lower compression part 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.

[0012] A discharge pipe 107 for discharging the high-pressure refrigerant compressed by the compression part 12 from the inside of the main body container 10 to the refrigeration cycle is provided through the upper part of the main body container 10. At the lower part of the main body container 10, a base member 310 for supporting the entire rotary compressor 1 is fixed by welding.

[0013] The accumulator 25 includes an accumulator suction pipe 27 for sucking the refrigerant from the refrigeration cycle into the accumulator 25, an upper gas-liquid separation pipe 31T and a lower gas-liquid separation pipe 31S for sending the gaseous refrigerant to the compression part 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 part suction pipe 102T through the upper connecting pipe 104T. The lower gas-liquid separation pipe 31S is connected to the lower compression part suction pipe 102S through the lower connecting pipe 104S.

[0014] Figure 2 is an exploded perspective view showing the compression section 12. As shown in FIGS. 1 and 2, the compression section 12 includes an upper cylinder 121T, a lower cylinder 121S, an intermediate partition plate 140, an upper end plate 160T, and a lower end plate 160S. The upper end plate 160T, the upper cylinder 121T, the intermediate partition plate 140, the lower cylinder 121S, and the lower end plate 160S are stacked in this order and fixed by a plurality of bolts 175. A main bearing portion 161T is provided on the upper end plate 160T. A sub-bearing portion 161S is provided on the lower end plate 160S. 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, whereby the rotating shaft 15 is rotatably supported by the main bearing portion 161T and the sub-bearing portion 161S.

[0015] The motor 11 has a stator 111 disposed outside and a rotor 112 disposed inside. The stator 111 is fixed to the inner peripheral surface 10a of the main body container 10, for example, by shrink fitting or welding. The rotor 112 is fixed to the rotating shaft 15 by shrink fitting.

[0016] Inside the main body container 10, lubricating oil 18 in an amount such that the compression section 12 is substantially immersed is enclosed for lubricating the sliding members of the compression section 12 and for sealing between the high-pressure portion and the low-pressure portion in the cylinder chamber.

[0017] Next, the compression section 12 will be described in detail using Figure 2. The upper cylinder 121T is formed in an annular shape. The upper cylinder 121T has a cylindrical upper hollow section 130T inside, and the upper piston 125T is positioned in the upper hollow section 130T. The upper piston 125T is fitted into the upper eccentric section 152T of the rotating shaft 15 (Figure 1). The lower cylinder 121S is formed in an annular shape. The lower cylinder 121S has a cylindrical lower hollow section 130S inside, and the lower piston 125S is positioned in the lower hollow section 130S. The lower piston 125S is fitted into the lower eccentric section 152S of the rotating shaft 15.

[0018] The upper cylinder 121T is provided with an upper vane groove 128T extending from the upper hollow section 130T toward the outer circumference, and an upper vane 127T is positioned in the upper vane groove 128T. The upper cylinder 121T is provided with an upper spring hole 124T that connects from the outer circumference to the upper vane groove 128T, and an upper spring 126T is positioned in the upper spring hole 124T. The lower cylinder 121S is provided with a lower vane groove 128S extending from the lower hollow section 130S toward the outer circumference, and a lower vane 127S is positioned in the lower vane groove 128S. The lower cylinder 121S is provided with a lower spring hole 124S that connects from the outer circumference to the lower vane groove 128S, and a lower spring 126S is positioned in the lower spring hole 124S.

[0019] One end of the upper vane 127T is pressed against the upper piston 125T by the upper spring 126T, thereby dividing the upper cylinder chamber, which is the space outside the upper piston 125T in the upper hollow portion 130T of the upper cylinder 121T, into an upper intake chamber 131T and an upper compression chamber 133T. The upper cylinder 121T is provided with an upper intake hole 135T that communicates with the upper intake chamber 131T from the outer circumference. The upper compression intake pipe 102T is connected to the upper intake hole 135T. One end of the lower vane 127S is pressed against the lower piston 125S by the lower spring 126S, thereby dividing the lower cylinder chamber, which is the space outside the lower piston 125S in the lower hollow portion 130S of the lower cylinder 121S, into a lower intake chamber 131S and a lower compression chamber 133S. The lower cylinder 121S is provided with a lower intake hole 135S that communicates with the lower intake chamber 131S from the outer circumference. The lower intake port 135S is connected to the lower compression intake pipe 102S.

[0020] 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 restricts the warping of the upper discharge valve 200T are fixed to the upper end plate 160T by upper rivets 202T. An upper end plate cover 170T is positioned above the upper end plate 160T, covering the upper discharge hole 190T, and an upper end plate cover chamber 180T is formed, which is closed by the upper end plate 160T and the upper end plate cover 170T. 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 and the upper cylinder 121T. The upper end plate cover 170T is provided with an upper end plate cover discharge hole 172T that connects the upper end plate cover chamber 180T to the inside of the main container 10. Furthermore, when the compression section 12 is installed inside the main container 10, the inner circumferential surface 10a of the main container 10 is shrink-fitted to the outer circumferential surface 182a of the upper end plate 160T, and is joined to the main container 10 by multiple welds.

[0021] 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 retainer 201S that restricts the warping of the lower discharge valve 200S are fixed to the lower end plate 160S by lower rivets 202S. A lower end plate cover 170S is positioned below the lower end plate 160S, covering the lower discharge hole 190S, and the lower end plate 160S and the lower end plate cover 170S form a lower end plate cover chamber 180S that is closed off (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.

[0022] Furthermore, the compression section 12 is provided with a refrigerant passage hole 136 (see Figure 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.

[0023] The following describes the flow of refrigerant due to the rotation of the rotating shaft 15. As the rotating shaft 15 rotates, the upper piston 125T fitted into the upper eccentric part 152T of the rotating shaft 15 and the lower piston 125S fitted into the lower eccentric part 152S revolve, causing the upper intake chamber 131T and the lower intake chamber 131S to expand in volume and draw in refrigerant. As the refrigerant intake path, the low-pressure refrigerant of the refrigeration cycle is drawn into the accumulator 25 through the accumulator intake 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 intake chamber 131T through the upper connecting pipe 104T and the upper compression section intake pipe 102T. Similarly, the gaseous refrigerant drawn into the lower gas-liquid separation pipe 31S is drawn into the lower suction chamber 131S through the lower connecting pipe 104S and the lower compression section suction pipe 102S.

[0024] Next, the flow of the discharged refrigerant due to 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 through the upper end plate cover discharge hole 172T provided in the upper end plate cover 170T.

[0025] Furthermore, the rotation of the rotating shaft 15 causes the lower piston 125S, fitted into the lower eccentric portion 152S of the rotating shaft 15, to revolve, 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 container 10 from the upper end plate cover discharge hole 172T provided in the upper end plate cover 170T.

[0026] The refrigerant discharged into the main container 10 is guided to the top of the motor 11 through a notch (not shown) connecting the top and bottom on the outer circumference of the stator 111, or a gap (not shown) in the winding portion of the stator 111, or a gap 115 (see Figure 1) between the stator 111 and the rotor 112, and is discharged from a discharge pipe 107 located at the top of the main container 10.

[0027] 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 by the centrifugal force of the rotating shaft 15, passing through the inside of the rotating shaft 15 (not shown). The lubricating oil 18 supplied to the compression section 12 is drawn into the refrigerant, becomes atomized, and is discharged into the main container 10 together with the refrigerant. The lubricating oil 18 that has been discharged into the main container 10 as atomization is separated from the refrigerant by centrifugal force due to the rotational force of the motor 11, and returns to the lower part of the main container 10 as oil droplets. However, some of the lubricating oil 18 is not separated and is discharged into the refrigeration cycle together with the refrigerant. The lubricating oil 18 discharged into the refrigeration cycle circulates through the refrigeration cycle and returns to the accumulator 25, where it is separated and remains in the lower part of the accumulator 25. The lubricating oil 18 remaining in the lower part of the accumulator 25 is drawn into the upper intake chamber 131T and the lower intake chamber 131S together with the intake refrigerant.

[0028] (Characteristic configuration of rotary compressor 1) Next, the characteristic configuration of the rotary compressor 1 will be described. Figure 3 is a perspective view showing the vane 127. Since the upper vane 127T and the lower vane 127S (hereinafter also referred to as vane 127) have the same structure, the upper vane 127T will be described below, and the description of the lower vane 127S will be omitted. 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 which serves as an end plate, and a back surface 129f that is pressed by the upper spring 126T. To elaborate on the lower vane 127S, it has a first side surface 129b and a second side surface 129c that slide against the inner surface of the lower vane groove 128S, a first end surface 129d that slides against the end surface of the intermediate partition plate 140 which serves as an end plate, and a second end surface 129e that slides against the end surface of the lower end plate 160S. The first side surface 129b and the second side surface 129c, and the first end surface 129d and the second end surface 129e are each formed flat.

[0029] 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. On the back surface 129f of the upper vane 127T, an engaging portion 138 is formed by cutting out a part of the flat back surface 129f, into which the end of the upper spring 126T engages. The end of the upper spring 126T engages with the engaging portion 138 of the lower vane 127S.

[0030] As shown in Figure 4, the vane 127 comprises a base material layer 210, a tip surface high-hardness coating layer 220, a first side nitriding diffusion layer 221, a second side nitriding diffusion layer 222, and a tip surface nitriding diffusion layer 223. Figure 4 is a cross-sectional view showing the tip surface 129a, the first side surface 129b, and the second side surface 129c of the vane 127. Figure 4 shows a cross-section where the vane 127 intersects with a plane parallel to the plane along which the first end surface 129d or the second end surface 129e of the vane 127 is aligned. The base material layer 210 is formed of a material with a chromium Cr content exceeding 4.5 wt%. Examples of materials used include SUS440C (a type of martensitic stainless steel) with a chromium content of approximately 16 wt% to 18 wt%, SKD61 (a type of die steel) with a chromium content of approximately 4.8 wt% to 5.5 wt%, and SKD11 (a type of die steel) with a chromium content of approximately 11.0 wt% to 13.0 wt%. In this way, the vane 127 ensures appropriate wear resistance and seizure resistance by forming the base layer 210 with a material having a chromium content exceeding 4.5 wt%. Furthermore, when the vane 127 is formed with a stainless steel having a chromium content exceeding 10 wt%, sufficient wear resistance and seizure resistance can be ensured, especially for the first side surface 129b and the second side surface 129c, which have large sliding surfaces.

[0031] The tip surface 129a of the vane 127 is covered with a tip surface high-hardness coating layer 220 so that the base material layer 210 is not exposed at the tip surface 129a. The tip surface high-hardness coating layer 220 is formed from a material with a Vickers hardness of 1500 HV or higher. Examples of such materials include diamond-like carbon (DLC), chromium nitride (CrN), and dichromium nitride (Cr2N).

[0032] The first side surface 129b of the vane 127 is covered by a first side nitride diffusion layer 221 so that the base material layer 210 is not exposed on the first side surface 129b. The first side nitride diffusion layer 221 is formed by the penetration of nitrogen atoms N into the material on which the base material layer 210 is formed. Examples of such nitride layers include a nitride diffusion layer in which nitrogen atoms N are solid-dissolved in the material on which the base material layer 210 is formed, forming a body-centered cubic α (alpha) phase, and a dense layer in which iron nitride Fe4N is the main component and forms a face-centered cubic γ' (gamma prime) phase. The second side surface 129c of the vane 127 is covered by a second side nitride diffusion layer 222 so that the base material layer 210 is not exposed on the second side surface 129c. The second side nitride diffusion layer 222 is formed in the same manner as the first side nitride diffusion layer 221.

[0033] The tip surface nitride diffusion layer 223 is positioned between the base material layer 210 and the tip surface high hardness coating layer 220 on the tip surface 129a so that the base material layer 210 and the tip surface high hardness coating layer 220 do not come into direct contact. The tip surface nitride diffusion layer 223 is formed in the same manner as the first side surface nitride diffusion layer 221 and the second side surface nitride diffusion layer 222.

[0034] Figure 5 is a cross-sectional view showing the leading edge 129a, the first end face 129d, and the second end face 129e of the vane 127. Figure 5 shows a cross-section where the vane 127 intersects with a plane parallel to the plane along which the first side surface 129b or the second side surface 129c of the vane 127 is aligned. The vane 127 further comprises a first end face nitriding diffusion layer 231 and a second end face nitriding diffusion layer 232. The first end face 129d of the vane 127 is covered by the first end face nitriding diffusion layer 231 so that the base material layer 210 is not exposed at the first end face 129d. The second end face 129e of the vane 127 is covered by the second end face nitriding diffusion layer 232 so that the base material layer 210 is not exposed at the second end face 129e. The first end face nitride diffusion layer 231 and the second end face nitride diffusion layer 232 are formed in the same manner as the first side surface nitride diffusion layer 221, the second side surface nitride diffusion layer 222, and the tip surface nitride diffusion layer 223.

[0035] The vane 127 has a tip surface 129a that is covered with a tip surface high-hardness coating layer 220, thereby ensuring adequate wear resistance of the tip surface 129a so that it does not wear down when the rotary compressor 1 compresses the refrigerant. Furthermore, the vane 127 has a first side surface 129b and a second side surface 129c that are covered with a first side surface nitride diffusion layer 221 and a second side surface nitride diffusion layer 222, respectively, thereby ensuring adequate wear resistance of the first side surface 129b and the second side surface 129c so that they do not wear down when the rotary compressor 1 compresses the refrigerant. Furthermore, the vane 127 is coated with a first end face 129d and a second end face 129e by a first end face nitriding diffusion layer 231 and a second end face nitriding diffusion layer 232, respectively, so that the wear resistance of the first end face 129d and the second end face 129e is adequately ensured so that they do not wear down when the rotary compressor 1 compresses the refrigerant. In addition, since the tip surface 129a is particularly susceptible to wear, it is preferable to ensure wear resistance by a high-hardness coating rather than nitriding treatment.

[0036] Furthermore, the vane 127 has a tip surface nitriding diffusion layer 223 positioned between the base material layer 210 and the tip surface high hardness coating layer 220, which allows the tip surface high hardness coating layer 220 to adhere more strongly to the base material layer 210. Therefore, the vane 127 can prevent the tip surface high hardness coating layer 220 from peeling off from the tip surface 129a when the rotary compressor 1 is compressing the refrigerant.

[0037] (Method for manufacturing vanes in the examples) The method for manufacturing the vane in this embodiment is the method for manufacturing the vane 127 described above. Figure 6 is a schematic diagram illustrating the method for manufacturing the vane in this embodiment. First, a plate 301, which is the material for forming the base material layer 210, is prepared. The plate 301 is cut into the approximate shape of the vane 127 (step S1), and a post-cut vane 302 is formed. A first side surface 129b, a second side surface 129c, and a back surface 129f are formed on the post-cut vane 302, an engaging portion 138 is formed, and the base material layer 210 is formed.

[0038] After cutting, the vane 302 is ground (step S2) to form a vane 303 with a first end face 129d and a second end face 129e. The vane 303 with a rough end face is further ground (step S3) to form a vane 304 with a tip R-face ground, where a tip surface 129a is formed. The vane 304 with a tip R-face ground is further ground (step S4) to form a vane 305 with a fine end face.

[0039] After the end face is polished, the vane 305 is subjected to nitriding treatment (step S5), and the vane 306 is formed after nitriding treatment. Examples of nitriding treatments include gas nitriding, gas soft nitriding, and ion nitriding. During the nitriding treatment, nitrogen atoms N penetrate into the base material layer 210 from the tip surface 129a, the first side surface 129b, the second side surface 129c, the first end face 129d, and the second end face 129e, and the nitrogen atoms N diffuse into the base material layer 210.

[0040] Figure 7 is a cross-sectional view showing the tip surface 129a, the first side surface 129b, and the second side surface 129c of the nitrided vane 306 in the manufacturing method of the embodiment. A nitrided layer 311 is formed on the surface of the nitrided vane 306 by the diffusion of nitrogen atoms N into the base material layer 210. The surface of the nitrided vane 306 is covered with the nitrided layer 311 so that the base material layer 210 is not exposed on the surface of the nitrided vane 306.

[0041] The nitrided layer 311 comprises a nitride compound layer 312 and a nitride diffusion layer 313. The nitride compound layer 312 is mainly composed of iron nitride Fe2N and Fe3N and is formed from an ε (epsilon) phase with a close-packed hexagonal structure. The nitride compound layer 312 is exposed on the surface of the vane 306 after nitriding. The nitride diffusion layer 313 is formed similarly to the first side nitride diffusion layer 221, the second side nitride diffusion layer 222, the tip surface nitride diffusion layer 223, the first end surface nitride diffusion layer 231, and the second end surface nitride diffusion layer 232. The nitride diffusion layer 313 is formed between the base material layer 210 and the nitride compound layer 312 so that the nitride diffusion layer 313 is not exposed on the surface of the vane 306 after nitriding and so that the base material layer 210 and the nitride compound layer 312 do not come into direct contact.

[0042] The nitride diffusion layer 313 comprises a first side nitride diffusion layer 221, a second side nitride diffusion layer 222, a tip surface nitride diffusion layer 223, a first end surface nitride diffusion layer 231, and a second end surface nitride diffusion layer 232. That is, the first side nitride diffusion layer 221, the second side nitride diffusion layer 222, the tip surface nitride diffusion layer 223, the first end surface nitride diffusion layer 231, and the second end surface nitride diffusion layer 232 are formed by nitride treatment of the base material layer 210.

[0043] As shown in Figure 6, the vane 306 after nitriding is lengthened by grinding the back surface 129f (step S6), forming the length-adjusted vane 307. The length-adjusted vane 307 is formed such that the plane along which the back surface 129f follows is parallel to the straight line along which the front surface 129a follows, and the distance between the front surface 129a and the back surface 129f is equal to a predetermined vane length (hereinafter referred to as the vane length before white layer grinding).

[0044] Multiple length-adjusted vanes 321, manufactured in the same manner as the length-adjusted vane 307, are appropriately placed on the mounting surface 315 such that the back surface 129f of each of the multiple length-adjusted vanes 321 is in contact with the flat mounting surface 315, as shown in Figure 8. Figure 8 is a perspective view showing multiple length-adjusted vanes 321 in the manufacturing method of the embodiment. The multiple length-adjusted vanes 321 are further appropriately arranged so that the first end surface 129d and the second end surface 129e are in close contact. That is, the first end surface 129d of the length-adjusted vane 307 is in close contact with the second end surface 129e of the other length-adjusted vanes 322 among the multiple length-adjusted vanes 321 when the multiple length-adjusted vanes 321 are appropriately arranged. The second end face 129e of the length-adjusted vane 307 is in close contact with the first end face 129d of another length-adjusted vane 323 among the multiple length-adjusted vanes 321 when the multiple length-adjusted vanes 321 are properly aligned.

[0045] Multiple length-adjusted vanes 321 are ground simultaneously using a dedicated grinding wheel driven with respect to the mounting surface 315, with the vanes 321 properly aligned. Specifically, the length-adjusted vanes 307 are ground with respect to the back surface 129f so that the distance between the front surface 129a and the back surface 129f of each of the multiple length-adjusted vanes is equal to a predetermined vane length (step S7), thereby forming white-layer ground vanes 308.

[0046] The trajectory 331 that the grinding wheel used in step S7 passes through during the process in step S7 is positioned on the side of the nitride diffusion layer 313 from the interface between the base material layer 210 and the nitride diffusion layer 313, and on the side of the nitride diffusion layer 313 from the interface between the nitride compound layer 312 and the nitride diffusion layer 313, as shown in Figure 9, when multiple length-adjusted vanes 321 are properly placed on the mounting surface 315. Figure 9 is a cross-sectional view showing the tip surface 129a, the first side surface 129b, and the second side surface 129c of the white layer-ground vane 308 in the vane manufacturing method of the embodiment. That is, the vane length of the white layer-ground vane 308 after the process in step S7 is shorter than the length calculated by subtracting the thickness of the nitride compound layer 312 from the vane length before white layer grinding, and longer than the length calculated by subtracting the thickness of the nitride layer 311 from the vane length before white layer grinding.

[0047] After white layer grinding, the tip surface 129a of the vane 308 is exposed at the tip surface 129a due to the arrangement of the trajectory 331 in step S7, as the nitride compound layer 312 has been removed. Furthermore, the tip surface nitride diffusion layer 223 of the nitride diffusion layer 313 is not removed from the tip surface 129a of the vane 307 after length adjustment in step S7, and remains on the tip surface 129a of the vane 308 after white layer grinding. For this reason, the tip surface 129a of the vane 308 after white layer grinding is covered with the tip surface nitride diffusion layer 223 so that the base material layer 210 is not exposed at the tip surface 129a.

[0048] As shown in Figure 6, the vane 308 after white layer grinding has its first end face 129d and second end face 129e ground to adjust its height (distance between the first end face 129d and the second end face 129e), and the perpendicularity between the tip face 129a and the first end face 129d and the second end face 129e is also adjusted (step S8), forming the height-adjusted vane 309. The height-adjusted vane 309 is formed such that the distance between the first end face 129d and the second end face 129e is equal to a predetermined vane height. The height-adjusted vane 309 is further formed such that the first end face 129d is perpendicular to the tip face 129a, and the second end face 129e is perpendicular to the tip face 129.

[0049] The nitride compound layer 312 of the vane 308 after white layer grinding is removed from the first end face 129d and the second end face 129e during the height adjustment process in step S8. The first side lateral nitride diffusion layer 221 and the second side lateral nitride diffusion layer 222 of the nitride diffusion layer 313 of the vane 308 after white layer grinding are not removed from the first end face 129d and the second end face 129e during the height adjustment process in step S8 and remain on the vane 309 after height adjustment. Therefore, the first end face 129d and the second end face 129e of the vane 309 after height adjustment are covered by the first side lateral nitride diffusion layer 221 and the second side lateral nitride diffusion layer 222 so that the base material layer 210 is not exposed at the first end face 129d and the second end face 129e.

[0050] Multiple height-adjusted vanes, manufactured in the same manner as the height-adjusted vane 309, are appropriately arranged so that the first side surface 129b and the second side surface 129c are in close contact, and the first end surface 129d and the second end surface 129e are in close contact. With the multiple height-adjusted vanes appropriately arranged, the multiple height-adjusted vanes are subjected to CVD (chemical vapor deposition) or PVD (physical vapor deposition) (step S9). The height-adjusted vane 309 is formed when the tip surface 129a is covered with a high-hardness coating layer by the CVD or PVD coating applied to the multiple height-adjusted vanes. The first side surface 129b, the second side surface 129c, the first end surface 129d, and the second end surface 129e of the vane 127 are not covered with the high-hardness coating layer because the CVD or PVD coating was applied with the multiple height-adjusted vanes appropriately arranged. The first side surface 129b, the second side surface 129c, the first end surface 129d, and the second end surface 129e of the vane 127 are covered by a first side surface nitride diffusion layer 221, a second side surface nitride diffusion layer 222, a first end surface nitride diffusion layer 231, and a second end surface nitride diffusion layer 232, respectively, so that the base material layer 210 is not exposed.

[0051] [Comparative example vane manufacturing method] The comparative example vane manufacturing method, as shown in Figure 10, includes the same steps S1 to S5 as the vane manufacturing method of the previously described embodiment, but the steps from step S6 onwards of the vane manufacturing method of the previously described embodiment are replaced with other processes. Figure 10 is a schematic diagram illustrating the comparative example vane manufacturing method. In the comparative example vane manufacturing method, the nitrided vane 306 is formed by performing the steps S1 to S5, similar to the vane manufacturing method of the previously described embodiment.

[0052] After nitriding, the vane 306 is ground to adjust its height (step S101) by grinding the first end face 129d and the second end face 129e, similar to the process in step S8 of the vane manufacturing method of the embodiment described above, thereby forming the height-adjusted vane 401. The height-adjusted vane 401 is formed such that the distance between the first end face 129d and the second end face 129e is equal to the vane height after the height adjustment process in step S101 is performed. The height-adjusted vane 401 is further formed such that the first end face 129d is perpendicular to the tip face 129a, and the second end face 129e is perpendicular to the tip face 129a.

[0053] The nitride compound layer 312 of the vane 306 after nitriding is removed from the first end face 129d and the second end face 129e during the height adjustment process in step S101. The first side nitriding diffusion layer 221 and the second side nitriding diffusion layer 222 of the nitrided diffusion layer 313 of the vane 306 after nitriding are not removed from the first end face 129d and the second end face 129e during the height adjustment process in step S101 and remain on the vane 401 after height adjustment. For this reason, the first end face 129d and the second end face 129e of the vane 401 after height adjustment are covered by the first end face nitride diffusion layer 231 and the second end face nitride diffusion layer 232, respectively, so that the base material layer 210 is not exposed at the first end face 129d and the second end face 129e.

[0054] Multiple height-adjusted vanes, manufactured in the same manner as the height-adjusted vane 401, are appropriately placed on the mounting surface 315 such that the back surface 129f of each of the multiple length-adjusted vanes 321 contacts the flat mounting surface 315, similar to the multiple length-adjusted vanes 321 in the vane manufacturing method of the previously described embodiment. The multiple height-adjusted vanes are further appropriately arranged so that the first end surface 129d and the second end surface 129e are in close contact.

[0055] Multiple height-adjusted vanes 401 are ground simultaneously using a dedicated grinding wheel driven with respect to the mounting surface 315, with the vanes properly aligned. Specifically, the vanes 401 are ground with respect to the back surface 129f so that the distance between each vane's front surface 129a and back surface 129f is equal to the vane length (step S102), forming white-layer ground vanes 402. The nitrided compound layer 312 is removed from the front surface 129a of the white-layer ground vanes 402 as a result of grinding the front surface 129a of the height-adjusted vanes 401, exposing the nitride diffusion layer 313 at the front surface 129a.

[0056] After grinding the white layer, the vane 402 is subjected to a CVD or PVD method (step S103) similar to the treatment in step S9 of the vane manufacturing method of the previously described embodiment, and the tip surface 129a is covered with a high-hardness coating layer 404 to form the comparative example vane 403.

[0057] The distance between the leading edge 129a and the back surface 129f of the multiple height-adjusted vanes 401 may differ for each of the multiple height-adjusted vanes because the plate 301 is roughly cut to the approximate shape of the vane 127 during the process in step S1. For this reason, the multiple height-adjusted vanes may include under-ground and over-ground vanes, as described below.

[0058] Figure 11 is a cross-sectional view showing the tip surface 129a, the first side surface 129b, and the second side surface 129c of the vane 411 after grinding height adjustment in the comparative example vane manufacturing method. The vane 411 after grinding height adjustment is formed such that the distance between the interface 412 between the nitride compound layer 312 and the nitride diffusion layer 313 at the tip surface 129a and the back surface 129f is shorter than the vane length. At this time, the trajectory 413 that the grinding wheel used in step S102 passes through in step S102 is positioned on the nitride compound layer 312 side of the interface 412 when the vane 411 after grinding height adjustment is properly placed on the mounting surface 315. Therefore, after adjusting the grinding height, the grinding wheel does not remove the nitride diffusion layer 313 on the tip surface 129a of the vane 411. As a result, after adjusting the grinding height, the nitride compound layer 312 remains on the tip surface 129a of the vane 411, and the nitride diffusion layer 313 is not exposed on the tip surface 129a.

[0059] When the vane 411, after adjusting the height due to insufficient grinding, is processed in step S103 with the nitride compound layer 312 remaining on the tip surface 129a, the nitride compound layer 312 is positioned between the high-hardness coating layer and the nitride diffusion layer 313 that cover the tip surface 129a. Because the nitride compound layer 312 is brittle, the high-hardness coating layer covering the tip surface 129a becomes more prone to peeling off from the tip surface 129a due to the position of the nitride compound layer 312 between the high-hardness coating layer and the nitride diffusion layer 313. In other words, the vane 127 manufactured by the vane manufacturing method of the above-described embodiment can prevent the high-hardness coating layer 220 from peeling off from the tip surface 129a compared to the vane 411 after adjusting the height due to insufficient grinding in the vane manufacturing method of the comparative example.

[0060] Figure 12 is a cross-sectional view showing the tip surface 129a, the first side surface 129b, and the second side surface 129c of the vane 415 after grinding over-height adjustment in the comparative example vane manufacturing method. The vane 415 after grinding over-height adjustment is formed such that the distance between the interface 416 between the base material layer 210 and the nitride diffusion layer 313 at the tip surface 129a and the back surface 129f is longer than the vane length. At this time, the trajectory 417 that the grinding wheel used in step S102 passes through in step S102 is positioned on the base material layer 210 side of the interface 416 when the vane 415 after grinding over-height adjustment is properly placed on the mounting surface 315. Therefore, after adjusting the grinding height, the grinding wheel also grinds the base material layer 210 on the tip surface 129a of the vane 415, and after adjusting the grinding height, the nitride diffusion layer 313 is removed from the tip surface 129a of the vane 415, and the base material layer 210 is exposed on the tip surface 129a.

[0061] After adjusting the height of the excessive grinding, when the vane 415 is processed in step S103 with the base material layer 210 exposed at the tip surface 129a, the high-hardness coating layer covering the tip surface 129a and the base material layer 210 adhere directly to each other. The high-hardness coating layer covering the tip surface 129a becomes more easily peeled off from the tip surface 129a due to the direct adhesion between the high-hardness coating layer and the base material layer 210. In other words, the vane 127 manufactured by the vane manufacturing method of the above-described embodiment can prevent the high-hardness coating layer 220 from peeling off from the tip surface 129a compared to the vane 415 after adjusting the height of excessive grinding in the vane manufacturing method of the comparative example.

[0062] [Effects of the vane manufacturing method in the example] The method for manufacturing the vane in the example is a method for manufacturing a vane 127. The vane 127 is used in a rotary compressor 1 and comprises a base material layer 210 made of a base material and a nitrided layer 311 formed by nitriding the material forming the base material layer 210. The nitrided layer 311 comprises a nitrided diffusion layer 313 and a nitrided compound layer 312. The method for manufacturing the vane in the example is, Step S5 is a step of nitriding the base material layer 210 so that the base material layer 210 is covered by the nitrided layer 311, After the nitriding treatment of the base material layer 210 (step S5) is performed, the length of the multiple vanes 127 is made uniform by grinding the back surface 129f of the base material layer 210 on the opposite side of the front surface 129a, using the front surface 129a as a reference (step S6), After the step of grinding the back surface 129f (step S6) is performed, the step of removing the nitride compound layer 312 from the tip surface 129a by grinding the tip surface 129a with respect to the back surface 129f so that the nitride diffusion layer 313 of the nitride layer 311 is exposed (step S7), It includes.

[0063] In this case, the vane manufacturing method of the embodiment allows for appropriate grinding of the tip surface 129a of the vane 127, even when the tip surface 129a is ground with reference to the back surface 129f, so as not to over-grind the tip surface 129a and expose the base material layer 210 at the tip surface 129a, or to insufficiently grind the tip surface 129a and leave the nitride compound layer 312 on the tip surface 129a. The vane manufacturing method of the embodiment allows for appropriate grinding of the tip surfaces 129a of multiple length-adjusted vanes 321 at once when the multiple length-adjusted vanes 321 are placed on a flat mounting surface 315 after the back surface 129f has been ground, thereby reducing the number of steps required to manufacture the vane 127 and reducing manufacturing costs.

[0064] Furthermore, the vane manufacturing method of the embodiment further includes, after the step of grinding the tip surface 129a (step S7), a step of grinding the first end surface 129d and the second end surface 129e that slide against the upper end plate 160T or the lower end plate 160S or the intermediate partition plate 140 (step S8). In this case, the vane manufacturing method of the embodiment can appropriately manufacture the vane 127 such that the first end surface 129d and the tip surface 129a are perpendicular, and the second end surface 129e and the tip surface 129a are perpendicular.

[0065] Furthermore, the vane manufacturing method of the embodiment further includes a step of covering the tip surface 129a with the tip surface high hardness coating layer 220 after the step of grinding the first end surface 129d and the second end surface 129e (step S8) has been performed (step S9). In this case, the vane manufacturing method of the embodiment can appropriately manufacture the vane 127 such that the first end surface 129d and the tip surface 129a are perpendicular to each other, and the second end surface 129e and the tip surface 129a are perpendicular to each other.

[0066] Incidentally, although the base material layer 210 described above is formed from a material with a chromium Cr content exceeding 4.5 wt%, it may also be formed from a material with a chromium Cr content less than 4.5 wt%. Even when the base material layer 210 is formed from a material with a chromium Cr content less than 4.5 wt%, the vane 127 is coated with a first end face nitriding diffusion layer 231 and a second end face nitriding diffusion layer 232, respectively, so that the first end face 129d and the second end face 129e do not wear down when the rotary compressor 1 compresses the refrigerant, and the wear resistance of the first end face 129d and the second end face 129e is appropriately ensured.

[0067] Incidentally, the vane manufacturing method of the embodiment described above includes the process of covering the tip surface 129a with the tip surface high hardness coating layer 220 in step S9, but the process of step S9 is not required. Even when the process of step S9 is not performed, the vane manufacturing method can properly grind the tip surface 129a so that the base material layer 210 is not exposed on the tip surface 129a and the nitride compound layer 312 does not remain on the tip surface 129a. Furthermore, even when the process of step S9 is not performed, the vane 127 has adequate wear resistance to the tip surface 129a because the tip surface 129a is covered with the tip surface nitride diffusion layer 223, so that the tip surface 129a does not wear down when the rotary compressor 1 compresses the refrigerant.

[0068] Incidentally, the vane manufacturing method of the embodiment described above includes a step S8 in which the first end face 129d and the second end face 129e are ground to adjust the height of the vane 127, but the step S8 is not required. Even if the step S8 is not performed, the vane manufacturing method can still properly grind the tip surface 129a so that the base material layer 210 is not exposed at the tip surface 129a and the nitride compound layer 312 does not remain on the tip surface 129a.

[0069] Incidentally, the first end face 129d and the second end face 129e of the vane 127 described above are covered by the first end face nitride diffusion layer 231 and the second end face nitride diffusion layer 232, respectively. However, in the process of step S8, the base material layer 210 may be exposed at the first end face 129d and the second end face 129e. Even when the base material layer 210 is exposed at the first end face 129d and the second end face 129e, the abrasion resistance of the first end face 129d and the second end face 129e is adequately ensured because the abrasion of the first end face 129d and the second end face 129e against the upper end plate 160T or the lower end plate 160S or the intermediate partition plate 140 is small.

[0070] Although examples have been described above, the examples are not limited to those described above. Furthermore, the components described above include those that can be easily imagined by a person skilled in the art, those that are substantially the same, and those that fall within the so-called equivalent range. Moreover, the components described above can be combined as appropriate. Furthermore, at least one of various omissions, substitutions, and modifications of the components can be made without departing from the gist of the examples. [Explanation of symbols]

[0071] 1: Rotary compressor 127: Bane 127S: Lower vane 127T: Upper vane 129a: Tip surface 129b: 1st side 129c:Second side 129d: First end surface 129e: 2nd end face 129f: Back 140: Intermediate partition plate 160S: Lower end plate 160T: Upper end plate 210: Base material layer 220: High-hardness coating layer on the tip surface 221: First side nitriding diffusion layer 222: Second side nitride diffusion layer 223: Tip surface nitride diffusion layer 231: First end-face nitriding diffusion layer 232: Second end-face nitriding diffusion layer 301: Board 302: Vanes after cutting 303: Vane after roughening of the end face 304: Vane after grinding of the tip R surface 305: Vane after precision grinding of the end face 306: Vanes after nitriding treatment 307: Vane after length adjustment 308: Vane after grinding the white layer 309: Vane after height adjustment 311: Nitride layer 312: Nitride compound layer 313: Nitride diffusion layer 321: Multiple length-adjustable vanes

Claims

1. Used in rotary compressors, A base material layer consisting of the base material, The material forming the base layer is subjected to a nitriding treatment to form a nitrided layer. A method for manufacturing vanes, The nitride layer comprises a nitride diffusion layer and a nitride compound layer. A step of nitriding the base material layer so that it is covered with a nitride layer, After the step of nitriding the base material layer is performed, the step of making the lengths of the multiple vanes uniform by grinding the back surface of the base material layer opposite to the tip surface with respect to the tip surface, After the step of grinding the back surface is performed, the step of grinding the tip surface with respect to the back surface so that the nitride diffusion layer of the nitride layer is exposed, thereby making the lengths of the multiple vanes uniform, A method for manufacturing vanes containing vanes.

2. After the step of grinding the tip surface is performed, the step of grinding the end surface of the base material layer that slides against the end plate is performed. A method for producing a vane according to claim 1, further comprising:

3. After the step of grinding the end face is performed, the step of covering the tip surface with a high-hardness coating layer is performed. A method for producing a vane according to claim 2, further comprising:

4. The aforementioned base material layer is formed from a material with a chromium content exceeding 4.5 wt%. A method for producing a vane according to claim 1.

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