JP2007278271A - Scroll member and scroll compressor equipped with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the thickness of a wrap of a scroll member to increase the capacity, secure strength, and suppress the deformation amount of the wrap within an allowable range. <P>SOLUTION: A fixed scroll member 126 of a compressor is equipped with a mirror surface 186a and the wrap 187. The wrap 187 having a spiral shape extends perpendicularly from the mirror surface 186a. In the wrap 187, a surface IS87a1 on the inner peripheral side of a part 187a near the winding start positioned near the center is inclined by only an angle θ with respect to a line orthogonal to the mirror surface 186a. Further, the inclination angle of other surfaces OS187a, IS187b, and OS187b of the wrap 187 with respect to the line orthogonal to the mirror surface 186a is zero. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a scroll member and a scroll compressor including the scroll member.

  One type of compressor in a refrigerating apparatus such as an air conditioner is a scroll compressor. In this scroll compressor, the volume of the crescent-shaped compression chamber formed between the spiral wraps of both scroll members is reduced by a movable scroll member that revolves without rotating its shaft with respect to the fixed scroll member. The pressure of the gas refrigerant is increased and discharged from the center.

  In the scroll member of such a scroll compressor, it is desirable to reduce the thickness of the spiral wrap from the viewpoint of improving the suction capacity, but a predetermined thickness is necessary from the viewpoint of securing strength and suppressing deformation.

With regard to the shape of this wrap, in Patent Document 1, while ensuring the thickness of the base end portion, the thickness is gradually reduced toward the free end portion, thereby ensuring both strength securing, deformation amount suppression, and capacity increase. .
Japanese Utility Model Publication No. 4-134686

  However, recently, it has been demanded that the scroll compressor be further increased in capacity without increasing its size.

  An object of the present invention is to provide a scroll member capable of suppressing the thickness of the wrap of the scroll member to increase the capacity, ensuring the strength and suppressing the deformation amount of the wrap to an allowable range, and a scroll compressor including the scroll member. It is to provide.

  The scroll member of the scroll compressor according to the first aspect of the present invention includes a flat portion and a wrap. The spiral-shaped wrap extends substantially perpendicularly from the plane portion. Of the wrap, the first surface on the inner peripheral side in the vicinity of the winding start located near the center is inclined by a first angle with respect to the line orthogonal to the plane portion. Further, in the wrap, the surfaces other than the first surface have an inclination angle smaller than the first angle with respect to a line orthogonal to the plane portion.

  Here, in the vicinity of the start of winding of the lap where the receiving pressure increases near the center, the first surface on the inner peripheral side is inclined at a first angle to greatly increase the strength and suppress deformation, About the part away from the center, it is avoiding that a capacity | capacitance falls significantly as an inclination angle smaller than a 1st angle. In addition, the outer peripheral surface of the vicinity of the winding start of the lap is a surface that performs compression work in contact with the other scroll member, and if a large inclination is given, the contour shape accuracy for each height from the flat portion of the wrap From the first angle, it is difficult to manage the surface accuracy of the inclined surface, such as the accuracy of the R shape at the boundary between the lap and the flat portion, and the leakage of refrigerant gas at the contact portions of both scroll members may increase. The tilt angle is also reduced.

  As described above, in the scroll compressor employing the scroll member of the present invention, since the pressure is relatively low in portions other than the vicinity of the wrap winding start point, the inclination angle emphasizes capacity increase rather than strength and deformation amount. For the first surface on the inner peripheral side of the portion near the start of wrapping, the pressure is relatively high, so the inclination angle is increased with emphasis on strength increase and deformation suppression, and the portion near the start of wrap winding As for the outer peripheral surface, the inclination angle is reduced in consideration of the management of surface accuracy and the degree of sealing of the compression chamber. Therefore, as a whole, the thickness of the wrap is suppressed to be small and a large capacity is ensured. On the other hand, the portion near the start of winding of the wrap with high pressure is inclined at the first angle, thereby ensuring the strength and the amount of deformation. Can be suppressed to an acceptable level.

  In addition, since the inclination angle is also reduced for portions other than the vicinity of the wrap winding start portion, it is advantageous in terms of management of surface accuracy and securing of the degree of sealing of the compression chamber.

  The scroll member according to the second invention is the scroll member according to the first invention, wherein a portion in the vicinity of the winding start of the wrap has a larger thickness at the boundary with the flat portion than the other portions of the wrap.

  The scroll compressor according to the third aspect of the present invention continuously reduces the volume of the sealed space formed by meshing the fixed scroll member and the movable scroll member by rotating the movable scroll member and sucks it into the sealed space. The compressed fluid is compressed. In this scroll compressor, at least one of the fixed scroll member and the movable scroll member is the scroll member of the first invention or the second invention.

  A scroll compressor according to a fourth aspect of the present invention is the compressor according to the third aspect, wherein the first surface of the wrap does not come into contact with the mating scroll member in the relative movement of the fixed scroll member and the movable scroll member. It is.

  Here, only the surface (first surface) of the wrap that does not come into contact with the mating scroll member is inclined (first angle) larger than the other surfaces. Therefore, a large inclination is usually disadvantageous in terms of surface accuracy management, but the surface (first surface) is not in contact with the other scroll member and does not affect the compression chamber sealing degree. , No disadvantages occur.

  A scroll compressor according to a fifth aspect is the compressor according to the fourth aspect, wherein the surface other than the first surface of the wrap has an inclination angle of substantially 0 ° with respect to a line orthogonal to the plane portion.

  Here, the surface of the surface other than the first surface of the wrap, which is a surface that comes into contact with the mating scroll member and affects the degree of sealing of the compression chamber, is most easily managed in terms of surface accuracy. An inclination angle of 0 ° is adopted. Thereby, high surface accuracy of the scroll member can be ensured, and the problem that the gas refrigerant leaks from the meshing portion of both scroll members to the adjacent chamber during the operation of the scroll compressor can be reduced.

  A scroll compressor according to a sixth aspect of the present invention is the compressor according to any one of the third to fifth aspects, wherein the surface other than the first surface of the wrap is subjected to cutting, and the first surface of the wrap Is not cut.

  Here, in view of the fact that the first surface of the lap is not in contact with the mating scroll member with which the first surface is engaged, and high accuracy is not required for the surface accuracy, cutting to the first surface is omitted to reduce costs. I am trying. On the other hand, the surface accuracy of the surfaces other than the first surface of the wrap is increased by cutting in order to improve the degree of sealing of the compression chamber.

  The fact that the first surface is not cut means that the entire first surface is not subjected to costly cutting, and the first surface is cut when cutting to other portions. This includes an event that part of the process has been processed.

  A scroll compressor according to a seventh aspect is the compressor according to the sixth aspect, wherein the scroll member is formed by injecting a material into a forming die and then subjected to cutting. And after shaping | molding with a shaping | molding die, the draft with respect to the shaping | molding die exists in surfaces other than a 1st surface and a 1st surface, and after that, a cutting process is given only to surfaces other than a 1st surface.

  Here, a draft when the mold is pulled is present in the intermediate product of the scroll member before cutting, and the draft is the inclination of the first surface of the lap as it is. Therefore, the first surface of the lap can be set to the first angle without cutting. On the other hand, for the surfaces other than the first surface of the lap, the surface accuracy is improved by cutting and the inclination is made smaller than the first angle to increase the capacity.

  A scroll compressor according to an eighth invention is the compressor according to any one of the third to seventh inventions, and compresses carbon dioxide.

  In a compressor for compressing high-pressure refrigerant such as carbon dioxide, it is necessary to increase the strength of the spiral center where stress is concentrated in the scroll member. In the compressor according to any one of the third to seventh inventions, the first surface located on the inner peripheral side of the vicinity of the winding start near the center is at a first angle (θ) with respect to a line orthogonal to the plane portion. Just tilted. For this reason, in this scroll compressor, the strength of the spiral central portion of the scroll member is increased. Therefore, in this scroll compressor, even when a high-pressure refrigerant such as carbon dioxide is compressed, the sliding component can withstand an increase in stress due to a high differential pressure. Moreover, the tooth height of this scroll member can be made high by this effect. That is, the capacity of the compression chamber can be increased while reducing the diameter of the wrap. When the diameter of the scroll compressor is reduced by reducing the diameter of the scroll member, the body portion of the casing is reduced in diameter. When the diameter of the body portion of the casing is reduced, the casing can exhibit the same pressure resistance strength with a thinner wall thickness than the conventional casing. For this reason, the raw material cost of a casing, etc. can be reduced. In addition, when the diameter of the scroll member is reduced, the spiral portion can be reduced, and the sliding area of the thrust portion where sliding is severe can be increased. Moreover, when such a scroll member is shape | molded by the semi-molten die-casting method etc., the surface roughness of the scroll member becomes smaller than what is obtained by the conventional casting method. For this reason, in this scroll compressor, even when a high-pressure refrigerant such as carbon dioxide is compressed, cracks from the surface of the scroll member hardly occur. Even if the scroll member is an unprocessed product, such damage is unlikely to occur. Carbon dioxide has a small volume circulation volume. For this reason, in the compressor for compressing high-pressure refrigerant such as carbon dioxide, the diameter of the discharge port may be smaller than that of the conventional product. Therefore, the space | interval from a discharge port to a spiral wall surface can be taken large. Therefore, the inclination angle θ of the first surface can be easily increased, and the strength of the spiral center can be further increased. As a result, in this scroll compressor, the scroll member having such a shape is more easily applied, and a greater effect can be obtained.

  In the scroll member according to the first to third inventions and the scroll compressor provided with the scroll member, since the pressure is relatively low for portions other than the vicinity of the wrap winding start portion, the capacity is increased more than the strength and deformation amount of the wrap. Emphasis is placed on reducing the tilt angle, and the pressure on the inner surface near the beginning of winding of the lap is relatively high, so the strength is increased and the tilt angle is increased with emphasis on increased strength and deformation. The inclination angle of the surface on the outer peripheral side in the vicinity of the start of winding is reduced in consideration of the management of surface accuracy and the degree of sealing of the compression chamber. Therefore, as a whole, the thickness of the wrap is suppressed to be small and a large capacity is ensured. On the other hand, the portion near the start of winding of the wrap with high pressure is inclined at the first angle, thereby ensuring the strength and the amount of deformation. Can be suppressed to an acceptable level.

  In the scroll compressor according to the fourth aspect of the invention, only the surface that does not contact the mating scroll member (first surface) is inclined greater than the other surfaces, and the inclination (inclination of the first angle). Hardly affects the degree of sealing of the compression chamber.

  In the scroll compressor according to the fifth aspect of the invention, the surface other than the first surface of the wrap employs an inclination angle of 0 ° that is most easily managed with respect to the surface accuracy. The problem of leaking into the next room can be reduced.

  In the scroll compressor according to the sixth aspect of the invention, in view of the fact that the first surface of the lap is not required to have high surface accuracy, the cutting process on the first surface is omitted. Thereby, cost reduction and shortening of manufacturing time can be aimed at.

  In the scroll compressor according to the seventh aspect of the invention, the draft when the mold is pulled is present in the intermediate product of the scroll member before cutting, and the draft is the inclination of the first surface of the lap as it is. Therefore, the first surface of the lap can be set to the first angle without cutting. On the other hand, for the surfaces other than the first surface of the lap, the surface accuracy can be improved by cutting, and the inclination can be made smaller than the first angle to increase the capacity.

  In the scroll compressor according to the eighth aspect of the invention, even when a high-pressure refrigerant such as carbon dioxide is compressed, the sliding component can withstand the increase in stress due to the high differential pressure. Further, when the scroll compressor is reduced in diameter by reducing the diameter of the scroll member, the body portion of the casing is reduced in diameter. When the diameter of the body portion of the casing is reduced, the casing can exhibit the same pressure resistance strength with a thinner wall thickness than the conventional casing. For this reason, the raw material cost of a casing, etc. can be reduced. In addition, when the diameter of the scroll member is reduced, the spiral portion can be reduced, and the sliding area of the thrust portion where sliding is severe can be increased. Further, when such a scroll member is formed by a semi-molten die casting method or the like, cracks from the surface of the scroll member are generated even when a high-pressure refrigerant such as carbon dioxide is compressed in the scroll compressor. Hard to occur. In this scroll compressor, the diameter of the discharge port may be smaller than that of the conventional product. Therefore, the space | interval from a discharge port to a spiral wall surface can be taken large. Therefore, the inclination angle θ of the first surface can be easily increased, and the strength of the spiral center can be further increased. As a result, in this scroll compressor, the scroll member having such a shape is more easily applied, and a greater effect can be obtained.

<Compressor configuration>
FIG. 1 shows a compressor 1 including a fixed scroll member 124 and a movable scroll member 126 which are scroll members according to an embodiment of the present invention. The compressor 1 constitutes a refrigerant circuit together with an evaporator, a condenser, an expansion valve, and the like, and plays a role of compressing a gas refrigerant in the refrigerant circuit. The compressor 1 mainly has a cylindrical sealed dome shape. The casing 10, the scroll compression mechanism 15, the Oldham ring 39, the drive motor 16, the lower main bearing 60, the suction pipe 19, and the discharge pipe 20 are configured. The scroll compression mechanism 15 includes a fixed scroll member 124 and a movable scroll member 126. Hereinafter, the components of the compressor 1 will be described in detail.

(1) Casing The casing 10 includes a substantially cylindrical trunk casing portion 11, a bowl-shaped upper wall portion 12 that is airtightly welded to the upper end portion of the trunk casing portion 11, and a lower end of the trunk casing portion 11. And a bowl-shaped bottom wall portion 13 which is welded to the portion in an airtight manner. The casing 10 mainly accommodates a scroll compression mechanism 15 that compresses a gas refrigerant and a drive motor 16 that is disposed below the scroll compression mechanism 15. The scroll compression mechanism 15 and the drive motor 16 are connected by a drive shaft 17 disposed so as to extend in the vertical direction in the casing 10. As a result, a gap space 18 is generated between the scroll compression mechanism 15 and the drive motor 16.

(2) Scroll Compression Mechanism As shown in FIG. 1, the scroll compression mechanism 15 mainly meshes with the housing 23, the fixed scroll member 124 disposed in close contact with the upper portion of the housing 23, and the fixed scroll member 124. And a movable scroll member 126.

(2-1) Fixed Scroll Member The fixed scroll member 124 is manufactured by cutting a fixed scroll intermediate body 24 (see FIGS. 2 and 3) formed by a semi-molten die casting method described later. The The fixed scroll intermediate body 24 includes an end plate 84 and a wrap 85 extending perpendicularly from the mirror surface 84 a of the end plate 84.

  As shown in FIGS. 4 to 6, the fixed scroll member 124 mainly has a mirror plate 184 and a spiral shape extending downward from the mirror surface 184 a of the mirror plate 184, similarly to the shape of the fixed scroll intermediate body 24 that is an intermediate product. And an involute wrap 185.

  The end plate 184 is formed with a discharge hole 41 communicating with a compression chamber 40 described later and an enlarged recess 42 communicating with the discharge hole 41. The discharge hole 41 is formed so as to extend in the vertical direction at the central portion of the end plate 184.

  The enlarged recess 42 is a recess formed on the upper surface of the end plate 184 so as to spread in the horizontal direction. Then, a lid 44 is fastened and fixed to the fixed scroll member 124 by a bolt 44a so as to close the enlarged concave portion 42. Then, the cover 44 is covered with the enlarged recess 42, whereby a muffler space 45 is formed as an expansion chamber that silences the operation sound of the scroll compression mechanism 15. The fixed scroll member 124 and the lid body 44 are sealed by being brought into close contact via a packing (not shown).

(2-2) Movable Scroll Member Similarly to the fixed scroll member 124, the movable scroll member 126 also cuts the movable scroll intermediate body 26 (see FIG. 7) formed by a semi-molten die-cast molding method to be described later. Manufactured by. The movable scroll intermediate body 26 includes a mirror plate 86, a wrap 87 extending perpendicularly from the mirror surface 86 a of the mirror plate 86, and a bearing portion 88.

  As shown in FIG. 8, the movable scroll member 126 mainly has a mirror plate 186 and a spiral shape (involute shape) extending upward from the mirror surface 186a of the mirror plate 186, similarly to the shape of the movable scroll intermediate body 26 which is an intermediate product. Lap 187, a bearing portion 188 extending downward from the lower surface of the end plate 186, and groove portions 189 formed at both ends of the end plate 186. The movable scroll member 126 is an outer drive type movable scroll and has a bearing portion 188 that fits into the outer peripheral groove of the drive shaft 17.

  The movable scroll member 126 is supported by the housing 23 by fitting the Oldham ring 39 (see FIG. 1) into the groove portion 189. Further, the upper end of the drive shaft 17 is fitted into the bearing portion 188. The movable scroll member 126 revolves inside the housing 23 without being rotated by the rotation of the drive shaft 17 by being incorporated in the scroll compression mechanism 15 in this way. The wrap 187 of the movable scroll member 126 meshes with the wrap 185 of the fixed scroll member 124, and a compression chamber 40 is formed between the contact portions of both wraps 185 and 187 (see FIG. 9). The compression chamber 40 is displaced toward the center as the movable scroll member 126 revolves, and the volume of the compression chamber 40 contracts. Thereby, in the compressor 1, the gas refrigerant that has entered the compression chamber 40 is compressed.

(2-3) Housing The housing 23 is press-fitted and fixed to the body casing portion 11 over the entire outer circumferential surface in the circumferential direction. That is, the body casing portion 11 and the housing 23 are in close contact with each other over the entire circumference. For this reason, the inside of the casing 10 is partitioned into a high-pressure space 28 below the housing 23 and a low-pressure space 29 above the housing 23. The housing 23 is fastened and fixed to the fixed scroll member 124 by a plurality of bolts 38 so that the upper end surface thereof is in close contact with the lower end surface of the fixed scroll member 124. The housing 23 is formed with a housing recess 31 that is recessed at the center of the upper surface, and a bearing portion 32 that extends downward from the center of the lower surface. A bearing hole 33 penetrating in the vertical direction is formed in the bearing portion 32, and the drive shaft 17 is rotatably fitted in the bearing hole 33 via a bearing 34.

(2-4) Others In the scroll compression mechanism 15, a communication passage 46 is formed across the fixed scroll member 124 and the housing 23. The communication passage 46 includes a scroll-side passage 47 formed in the fixed scroll member 124 and a housing-side passage 48 formed in the housing 23. The upper end of the communication passage 46, that is, the upper end of the scroll side passage 47 opens to the enlarged recess 42, and the lower end of the communication passage 46, that is, the lower end of the housing side passage 48 opens to the lower end surface of the housing 23. That is, the lower end opening of the housing side passage 48 serves as a discharge port 49 through which the refrigerant in the communication passage 46 flows into the gap space 18.

(3) Oldham ring The Oldham ring 39 is a member for preventing the rotation of the movable scroll member 126 as described above, and is fitted into an Oldham groove (not shown) formed in the housing 23. . The Oldham groove is an oval groove and is disposed at a position facing each other in the housing 23.

(4) Drive Motor The drive motor 16 is a DC motor, and is mainly rotatable with an annular stator 51 fixed to the inner wall surface of the casing 10 and a slight gap (air gap passage) inside the stator 51. And a rotor 52 housed in the housing. The drive motor 16 is arranged such that the upper end of the coil end 53 formed on the upper side of the stator 51 is at substantially the same height as the lower end of the bearing portion 32 of the housing 23.

  In the stator 51, a copper wire is wound around a tooth portion, and a coil end 53 is formed above and below. Further, the outer peripheral surface of the stator 51 is provided with core cut portions that are notched at a plurality of locations from the upper end surface to the lower end surface of the stator 51 and at predetermined intervals in the circumferential direction. The core cut portion forms a motor cooling passage 55 extending in the vertical direction between the body casing portion 11 and the stator 51.

  The rotor 52 is drivably coupled to the movable scroll member 126 of the scroll compression mechanism 15 via a drive shaft 17 disposed at the axial center of the body casing portion 11 so as to extend in the vertical direction. A guide plate 58 that guides the refrigerant discharged from the discharge port 49 of the communication passage 46 to the motor cooling passage 55 is disposed in the gap space 18.

(5) Lower Main Bearing The lower main bearing 60 is disposed in the lower space below the drive motor 16. The lower main bearing 60 is fixed to the body casing portion 11 and constitutes a lower end side bearing of the drive shaft 17 to support the drive shaft 17.

(6) Suction Pipe The suction pipe 19 is for guiding the refrigerant in the refrigerant circuit to the scroll compression mechanism 15 and is fitted into the upper wall portion 12 of the casing 10 in an airtight manner. The suction pipe 19 penetrates the low pressure space 29 in the vertical direction, and an inner end portion is fitted into the fixed scroll member 124.

(7) Discharge pipe The discharge pipe 20 is for discharging the refrigerant in the casing 10 to the outside of the casing 10, and is fitted into the body casing portion 11 of the casing 10 in an airtight manner. The discharge pipe 20 has an inner end 36 that is formed in a cylindrical shape extending in the vertical direction and is fixed to the lower end of the housing 23. The inner end opening of the discharge pipe 20, that is, the inflow port, is opened downward.

<Manufacturing method of fixed scroll member and movable scroll member>
As described above, the fixed scroll member 124 is manufactured by cutting the fixed scroll intermediate body 24 formed by the semi-melt molding method. The movable scroll member 126 is also manufactured by cutting the movable scroll intermediate body 26 formed by the semi-melt molding method. Hereinafter, the manufacture of the fixed scroll intermediate body 24 and the movable scroll intermediate body 26 by the semi-melt molding method and the manufacture of the fixed scroll member 124 and the movable scroll member 126 by the subsequent cutting process will be described.

(1) Manufacture of fixed scroll intermediate body and movable scroll intermediate body by semi-melt molding method (1-1) Material Iron material which is a raw material of fixed scroll intermediate body 24 and movable scroll intermediate body 26 is C: 2.3. 2.4 wt%, Si: 1.95 to 2.05 wt%, Mn: 0.6 to 0.7 wt%, P: <0.035 wt%, S: <0.04 wt%, Cr: 0.00 to 0 .50 wt%, Ni: 0.50 to 1.00 wt% added billet. A weight ratio here is a ratio with respect to the whole quantity. The billet means a material before final molding which is formed into a cylindrical shape or the like by a continuous casting apparatus after the iron material having the above components is melted in a melting furnace. Here, the content of C and Si is such that the tensile strength and tensile modulus are higher than those of flake graphite cast iron, and the fluidity suitable for molding a sliding part substrate having a complicated shape is provided. Have been determined to satisfy both. The content of Ni is determined so as to constitute a metal composition suitable for improving the toughness of the metal structure and preventing surface cracks during molding.

(1-2) Semi-molten die-cast molding method The above-described iron material is used to mold the fixed scroll intermediate body 24 and the movable scroll intermediate body 26 by a semi-molten die-cast molding method which is a kind of semi-melt molding method. Here, the semi-molten die casting method will be described taking the movable scroll intermediate body 26 as an example.

  As shown in FIG. 7, a mold 80 for semi-molten die-casting the movable scroll intermediate body 26 includes a first mold part 81 and a second mold part 82. The shape of the space formed when the first mold part 81 and the second mold part 82 are combined corresponds to the outer shape of the movable scroll intermediate body 26 to be molded. Further, the outer shape of the wrap molding portion of the second mold portion 82 of the mold 80 is set so as to ensure a draft when the movable scroll intermediate body 26 is separated from the mold 80. Specifically, the shape of the wrap molding portion of the second mold portion 82 is determined so that the entire surface of the wrap 87 is inclined by the first angle θ with respect to a line orthogonal to the mirror surface 86a. Accordingly, the thickness of the wrap 87 of the movable scroll intermediate body 26 at the boundary with the mirror surface 86a becomes t + t1 + t1 with respect to the thickness t of the tip.

  In the semi-molten die casting process, first, the billet is heated to high frequency to be in a semi-molten state. Next, when the billet in the semi-molten state is poured into the mold 80, a predetermined pressure is applied by a die cast machine to form the billet into a desired shape. And by taking out from the metal mold | die 80 and making it cool rapidly, the metal structure will become the whole whitened. Thereafter, when heat treatment is performed, the metal structure of the movable scroll intermediate body 26 changes from a whitened structure to a metal structure composed of pearlite / ferrite matrix and granular graphite.

  The graphitization and pearlization of the whitened structure can be adjusted by adjusting the heat treatment temperature, holding time, cooling rate, and the like. For example, as described in Honda R & D Technical Review Vol.14 No.1 paper "Study on the semi-melting technology of iron", cooling at 0.05 to 0.10 ° C / sec after holding at 950 ° C for 60 minutes By slowly cooling in the furnace at a speed, a metal structure having a tensile strength of about 500 MPa to 700 MPa and a Brinell hardness of about 150 to 200 can be obtained. Such a metal structure is soft and excellent in machinability because it has a ferrite center, but there is a possibility of forming a cutting edge during machining and reducing the tool life. Further, a metal having a tensile strength of about 600 MPa to 900 MPa and a Brinell hardness of about 200 to 350 by air cooling after holding at 1000 ° C. for 60 minutes and further holding for a predetermined time at a temperature slightly lower than the initial temperature. You can get an organization. In such a metal structure, those having hardness equivalent to flake graphite cast iron have machinability equivalent to flake graphite cast iron, and machinability compared to spheroidal graphite cast iron having equivalent ductility and toughness. Is excellent. In addition, by holding the oil at 1000 ° C. for 60 minutes and then cooling with oil, holding it for a predetermined time at a temperature slightly lower than the initial temperature, and then cooling with air, it has a tensile strength of about 800 MPa to 1300 MPa and a Brinell hardness of about 250 to 350. A metal structure can be obtained. Such a metal structure is hard because it has a pearlite center and is inferior in machinability, but has excellent wear resistance. However, there is a possibility of having aggressiveness to the sliding counterpart material due to being too hard.

(2) Manufacture of Fixed Scroll Member and Movable Scroll Member by Cutting Work The fixed scroll intermediate body 24 and the movable scroll intermediate body 26 formed by the above-mentioned semi-molten die-casting method are further subjected to a cutting process to produce a compressor. The final fixed scroll member 124 and the movable scroll member 126 to be incorporated into 1 are obtained.

  The fixed scroll member 124 shown in FIG. 4 is manufactured by machining the fixed scroll intermediate body 24 shown in FIGS. 2 and 3. Of the machining including the drilling of the discharge hole 41 and the like, here, the cutting for making the lap 85 into the lap 185 will be described.

  Here, the wrap 85 is in close contact with the lap 187 of the movable scroll member 126 that is the mating partner, and the surfaces OS85a, IS85b, and OS85b that can be the end portions of the compression chamber 40 and the wrap 187 of the movable scroll member 126 that is the mating partner. The first surface OS85a, IS85b, OS85b is cut and the latter surface IS85a is distinguished from the inner peripheral surface IS85a of the winding start vicinity portion 85a (portion close to the center of the wrap 85) that is not in close contact with the latter. No cutting process is applied. The surfaces OS85a, IS85b, and OS85b are an outer peripheral surface OS85a of the winding start vicinity portion 85a, an inner peripheral surface IS85b, and an outer peripheral surface OS85b of the portion 85b closer to the winding end than the winding start vicinity portion 85a. The surfaces OS85a, IS85b, and OS85b are cut by an end mill, and the inclination shown in FIGS. 2 and 3 is eliminated, so that the surfaces OS185a, IS185b, and OS185b shown in FIGS. 4 and 5 are obtained. In FIG. 5, surfaces OS85a, IS85b, and OS85b indicated by dotted lines are cut to finish the surfaces OS185a, IS185b, and OS185b indicated by solid lines. The inclination angle of these planes OS185a, IS185b, and OS185b with respect to the line orthogonal to the mirror plane 184a is 0 degree. On the other hand, the inner circumferential surface IS85a of the winding start vicinity portion 85a of the wrap 85 is left as it is as the inner peripheral surface of the winding start vicinity portion 185a in the final wrap 185 as well. FIG. 6 shows an enlarged view of the winding start vicinity portion 185a in FIG. In the vicinity of the winding start portion 185a of the wrap 185, the outer surface OS185a is a surface orthogonal to the mirror surface 184a, whereas the inner surface IS85a is a first angle θ with respect to a line orthogonal to the mirror surface 184a. Inclined. Accordingly, the portion 85a in the vicinity of the winding start of the wrap 185 has a larger thickness ta at the boundary with the mirror surface 184a than the other portion 85b of the wrap 185. The portion 85b other than the winding start vicinity portion 85a of the wrap 185 is cut to have the same thickness from the boundary with the mirror surface 184a to the tip, and the thickness is the tip of the winding start vicinity portion 85a shown in FIG. The thickness t is the same.

  The movable scroll member 126 shown in FIG. 8 is manufactured by machining the movable scroll intermediate body 26 shown in FIG. Of machining, here, cutting for making the lap 87 into a lap 187 will be described.

  Here, the wrap 87 is in close contact with the wrap 185 of the fixed scroll member 124, which is the mating partner, and the surfaces OS87a, IS87b, OS87b, which can be the ends of the compression chamber 40, and the wrap 185 of the fixed scroll member 124, which is the mating partner. The former surface OS87a, IS87b, OS87b is cut and the latter surface IS87a is distinguished from the inner peripheral surface IS87a of the winding start vicinity portion 87a (portion close to the center of the lap 87) that is not in close contact with the latter. No cutting process is applied. The surfaces OS87a, IS87b, and OS87b are an outer peripheral surface OS87a of the winding start vicinity portion 87a, an inner peripheral surface IS87b and an outer peripheral surface OS87b of the portion 87b closer to the winding end than the winding start vicinity portion 87a. The surfaces OS87a, IS87b, and OS87b are cut by an end mill, and the inclination shown in FIG. 7 is eliminated, resulting in the surfaces OS187a, IS187b, and OS187b shown in FIG. In FIG. 8, planes OS87a, IS87b, and OS87b indicated by dotted lines are cut and finished to planes OS187a, IS187b, and OS187b indicated by solid lines. The inclination angle of these planes OS187a, IS187b, OS187b with respect to a line perpendicular to the mirror plane 186a is 0 degree. On the other hand, the surface IS87a on the inner peripheral side of the winding start vicinity portion 87a of the wrap 87 is left as it is as the inner peripheral surface of the winding start vicinity portion 187a in the final wrap 187 as well. The winding start vicinity portion 187a of the wrap 187 has a surface OS187a on the outer peripheral side orthogonal to the mirror surface 186a, whereas a surface IS87a on the inner peripheral side is a first angle θ with respect to a line orthogonal to the mirror surface 186a. Inclined. As a result, the winding start vicinity portion 87a of the wrap 187 has a greater thickness ta at the boundary with the mirror surface 186a than the other portion 87b of the wrap 187. The portion 87b other than the winding start vicinity portion 87a of the lap 187 is cut to have the same thickness from the boundary with the mirror surface 186a to the tip, and the thickness is larger than the thickness ta as shown in FIG. The thickness t is small.

<Operation of compressor 1>
Next, the operation of the compressor 1 will be briefly described. First, when the drive motor 16 is driven, the drive shaft 17 rotates and the revolving operation is performed without the movable scroll member 126 rotating. Then, the low-pressure gas refrigerant is sucked into the compression chamber 40 from the peripheral side of the compression chamber 40 through the suction pipe 19 and is compressed as the volume of the compression chamber 40 changes, and becomes a high-pressure gas refrigerant. The high-pressure gas refrigerant is discharged from the central portion of the compression chamber 40 through the discharge hole 41 to the muffler space 45, and then passes through the communication passage 46, the scroll side passage 47, the housing side passage 48, and the discharge port 49. Then, it flows out into the gap space 18 and flows downward between the guide plate 58 and the inner surface of the body casing portion 11. When the gas refrigerant flows downward between the guide plate 58 and the inner surface of the body casing portion 11, a part of the gas refrigerant is diverted to form a circle between the guide plate 58 and the drive motor 16. Flow in the direction. At this time, the lubricating oil mixed in the gas refrigerant is separated. On the other hand, the other part of the diverted gas refrigerant flows downward in the motor cooling passage 55, flows to the lower motor space, and then reverses to become an air gap passage between the stator 51 and the rotor 52, or to communicate therewith. It flows upward through the motor cooling passage 55 on the side facing the passage 46 (left side in FIG. 1). Thereafter, the gas refrigerant that has passed through the guide plate 58 and the gas refrigerant that has flowed through the air gap passage or the motor cooling passage 55 merge in the gap space 18 and flow into the discharge pipe 20 from the inner end 36 of the discharge pipe 20. And discharged outside the casing 10. The gas refrigerant discharged to the outside of the casing 10 circulates through the refrigerant circuit, and is again sucked into the scroll compression mechanism 15 through the suction pipe 19 and compressed.

  A state in which the gas refrigerant is compressed in accordance with the volume change of the compression chamber 40 is shown in FIGS. 9 to 11 are cross-sectional views of the meshing portion of the wrap 185 of the fixed scroll member 124 and the wrap 187 of the movable scroll member, as viewed from above, and the movable scroll member 126 with respect to the fixed scroll member 124. Is turned, the state changes in the order of FIG. 9A, FIG. 9B, FIG. 10A, FIG. 10B, FIG. 11A, and FIG. As is clear from these figures, the surfaces IS85a and IS87a (surfaces shown by bold lines in the figure; see FIG. 12) on the inner peripheral side of the wraps 185a and 187 in the vicinity of the start of winding are shown in FIG. It does not contact the wrap, does not constitute the end of the compression chamber 40, and does not contribute to the compression work. Therefore, although the first angle θ is inclined, the surface accuracy of these surfaces IS85a and IS87a does not affect the sealing degree of the compression chamber 40.

<Characteristics of compressor 1>
(1)
Since ductile cast iron and high carbon steel, which are high-strength materials, are difficult to form near-net and have poor workability, conventional scroll compressors produce scroll members using ordinary cast iron such as FC250. There are many things.

  On the other hand, in the compressor 1 according to the present embodiment, the fixed scroll intermediate body 24 and the movable scroll intermediate body 26 are formed by using a semi-molten die casting method, thereby achieving high strength and high rigidity. The final fixed scroll member 124 and the movable scroll member 126 are formed in a near net shape.

  However, the scroll intermediates 24 and 26, which are semi-molten die-cast materials, are made strong by heat treatment, but the rigidity (Young's modulus) is constant and cannot be adjusted. Therefore, as the strength increases, the wraps 185 and 187 are simply thinned. If this is the case, the amount of deformation (deflection) of the laps 185 and 187 will increase during operation, and noise and wear may occur. In order to avoid this noise and wear, if the gap between the laps 185 and 187 is set large so as to allow a large amount of deformation, the degree of sealing of the compression chamber is lowered and the compression performance is lowered.

  In order to avoid this, rather than simply thinning the wraps 185 and 187, it is possible to increase the rigidity of the entire wraps 185 and 187 by thickening the base portion on the end plate 184 and 186 side and thinning the tip portion. However, if the base part is thickened as a whole, there is a demerit that the volume of the compression chamber is reduced. Further, by leaving an inclination on the side surfaces of the laps 185 and 187 where high accuracy is required, quality control (accuracy control as a surface) becomes difficult, and there is a risk of performance deterioration.

  Therefore, in the compressor 1 according to the present embodiment, the portions 185a and 187a in the vicinity of the winding start of the wraps 185 and 187 in which the pressure received from the refrigerant gas compressed near the center is increased to the inner surfaces IS85a and IS87a. While the inclination of the first angle θ is increased to greatly increase the strength and control the deformation amount, the portions 185b and 187b away from the center of the wraps 185 and 187 avoid the inclination and avoid a decrease in capacity. Yes. Further, the surfaces OS185a, OS187a on the outer peripheral side of the wraps 185a, 187a in the vicinity of the winding start are the surfaces that perform compression work in contact with the other scroll member. Since the refrigerant gas may become difficult and leakage of the refrigerant gas at the contact portion between the scroll members 124 and 126 may increase, the inclination is eliminated. The surfaces IS85a and IS87a on the inner peripheral side of the wraps 185a and 187a in the vicinity of the winding start of the wraps 185a and 187a are inclined at a first angle θ, but these surfaces IS85a and IS87a are compressed in contact with the other scroll member. Since it does not affect the degree of sealing of the chamber 40, no demerit occurs.

  As described above, in the compressor 1, the portions 185b and 187b other than the portions 185a and 187a in the vicinity of the winding start of the wraps 185 and 187 are inclined with an emphasis on increasing the capacity rather than the strength and the deformation amount because the pressure is relatively low. The angle is set to zero, and the inner circumferential surfaces IS85a and IS87a of the portions 185a and 187a in the vicinity of the winding start of the laps 185 and 187 are inclined with an emphasis on increasing strength and suppressing deformation because the pressure is relatively high. (First angle θ) For the surfaces OS185a and OS187a on the outer peripheral side of the wraps 185 and 187 in the vicinity of the winding start, the inclination angle is set to zero in consideration of surface accuracy management and the degree of sealing of the compression chamber 40 Yes. Therefore, as a whole, the thickness of the wraps 185 and 187 is kept small and a large capacity is ensured, while the winding start vicinity portions 185a and 187a of the high pressure wraps 185 and 187 are inclined by the first angle θ. Thus, the strength can be secured and the deformation amount can be suppressed to an allowable level.

  Note that the portions 185b and 187b other than the portions 185a and 187a in the vicinity of the winding start of the wraps 185 and 187 are also set to have an inclination angle of zero, which is advantageous in terms of management of surface accuracy and securing the degree of sealing of the compression chamber 40. ing.

(2)
In the compressor 1, the scroll members 124 and 126, except for the surfaces IS85a and IS87a that are inclined at the first angle θ, all other surfaces OS185a, IS185b, OS185b, OS187a, IS187b, and OS187b have an inclination angle of zero. It is said. As described above, since the surfaces that perform compression work in contact with the laps of the mating scroll members are made to have an inclination angle of zero, the surface accuracy of these surfaces can be easily managed, and the compressor 1 is in operation. The problem that the gas refrigerant leaks into the outer compression chamber 40 from the meshing portions of the wraps 185 and 187 of the scroll members 124 and 126 can be reduced.

(3)
The compressor 1 is a surface that does not come into contact with the other wraps 187 and 185 with which the inner peripheral surfaces IS85a and IS87a of the wraps 185a and 187a and the vicinity of the winding start vicinity 185a and 187a mesh, and has high surface accuracy. In view of the fact that is not required, the cutting process to these surfaces IS85a and IS87a is omitted. As a result, the cost is reduced and the time required for the cutting process is shortened.

(4)
In the compressor 1, a draft when the mold is pulled is present in the intermediate bodies 24 and 26 of the scroll members 124 and 126 before cutting, and the draft is directly inclined to the surfaces IS85a and IS87a of the laps 185 and 187. It has become. Therefore, the surfaces IS85a and IS87a of the laps 185 and 187 can be set to the first angle θ without cutting.

(5)
In the compressor 1, in the scroll members 124 and 126, the portions 185a and 187a in the vicinity of the winding start of the wraps 185 and 187 have inner surfaces OS185a and OS187a that are orthogonal to the mirror surfaces 184a and 186a. The circumferential surfaces IS85a and IS87a are inclined by a first angle θ with respect to a line orthogonal to the mirror surfaces 184a and 186a. As a result, the portions 85a and 87a in the vicinity of the winding start of the wraps 185 and 187 have a larger thickness ta at the boundary with the mirror surfaces 184a and 186a than the other portions 85b and 87b of the wraps 185 and 187. For this reason, in this compressor 1, the strength of the portions 185a and 187a in the vicinity of the winding start of the wraps 185 and 187 in the scroll members 124 and 126 is increased. Therefore, in the compressor 1, even when a high-pressure refrigerant such as carbon dioxide is compressed, the scroll members 124 and 126 can withstand an increase in stress due to a high differential pressure. Moreover, the tooth height of the scroll members 124 and 126 can be increased by this effect. That is, the capacity of the compression chamber 40 can be increased while reducing the diameter of the wraps 185 and 187. And if the compressor 1 can reduce in diameter in this way, the trunk | drum casing part 11 will be reduced in diameter. The diameter-reduced body casing portion 11 can exhibit the same pressure resistance strength with a thinner wall thickness than a conventional body casing. For this reason, the raw material cost etc. of the trunk | drum casing part 11 can be reduced. Further, the diameter of the wraps 185 and 187 of the scroll members 124 and 126 can be reduced. For this reason, the sliding area of a thrust part with severe sliding can be enlarged.

(6)
In the compressor 1, the scroll members 124 and 126 are manufactured by a semi-melt molding method. For this reason, the surface roughness of the scroll members 124 and 126 is smaller than that obtained by the conventional casting method. For this reason, in this compressor 1, even when a high-pressure refrigerant such as carbon dioxide is compressed, cracks from the surfaces of the scroll members 124 and 126 hardly occur.

<Modification>
In the above embodiment, the intermediate members 24 and 26 of the scroll members 124 and 126 of the compressor 1 are manufactured by a semi-melt molding method such as a semi-melt die casting method, but the present invention is not limited to this. Absent. For example, even in the case of a scroll member cast by injecting high-temperature hot metal material into the mold, the slope of the inner peripheral surface of the vicinity of the winding start of the lap center that does not contact the other scroll member in the compression operation By increasing only the angle, it is possible to ensure a large compression chamber volume while increasing strength and reducing deformation.

  However, in the case of a scroll member using a high-strength material that cannot be expected to have a relatively high rigidity compared to an increase in strength, the problem of deformation (deflection) in the vicinity of the winding start at the center of the wrap is highlighted. Therefore, the usefulness of the present invention for increasing the rigidity of only this portion is increased.

The longitudinal cross-sectional view of the compressor which concerns on one Embodiment of this invention. The bottom view of a fixed scroll intermediate body. III-III sectional drawing of FIG. The bottom view of a fixed scroll member. VV sectional drawing of FIG. FIG. 6 is a partially enlarged view of FIG. 5. The longitudinal cross-sectional view of the metal mold | die which shape | molds a movable scroll intermediate body. The longitudinal cross-sectional view of a movable scroll member. The figure which shows a mode that a gas refrigerant is compressed by the meshing state change of the lap | wrap of both scroll members. The figure which shows a mode that a gas refrigerant is compressed by the meshing state change of the lap | wrap of both scroll members. The figure which shows a mode that a gas refrigerant is compressed by the meshing state change of the lap | wrap of both scroll members. (A) The figure which shows the range of the surface of the inner peripheral side of the winding start vicinity part of the lap | wrap of a fixed scroll member. (B) The figure which shows the range of the surface of the inner peripheral side of the winding start vicinity part of the wrap of a movable scroll member.

Explanation of symbols

1 Compressor (Scroll compressor)
40 Compression chamber (sealed space)
81 Molding die 82 Molding die 124 Fixed scroll member 126 Movable scroll member 184a Mirror surface of fixed scroll member 185 Fixed wrap member wrap 185a Near wrap winding start portion of fixed scroll member IS85a Inner peripheral surface of wrap winding start portion OS185a Surface on the outer peripheral side in the vicinity of the winding start of the wrap 185b Part of the fixed scroll member wrap away from the center IS185b Surface on the inner peripheral side of the wrap away from the center OS185b Part of the wrap away from the center Outer surface 186a Mirror surface of movable scroll member 187 Movable scroll member wrap 187a Movable scroll member wrap start vicinity portion IS87a Inner wrap surface portion of wrap winding start portion OS187a Wrap start portion vicinity The outer peripheral side surface of the portion remote from the center of the inner circumferential side surface OS187b lap portion remote from the center of the portion IS187b wrap away from the center of the wrap circumferential side surface 187b movable scroll member

Claims (8)

Scroll members (124, 126) of the scroll compressor,
Plane portions (184a, 186a);
A first surface (IS85a, IS87a) that extends substantially perpendicularly from the plane portion, has a spiral shape, and is located on the inner peripheral side of the winding start vicinity portion (185a, 187a) close to the center is orthogonal to the plane portion. A wrap (185, 187), which is inclined with respect to a line by a first angle (θ), and a surface other than the first surface has an inclination angle with respect to a line orthogonal to the plane portion smaller than the first angle. ,
A scroll member comprising: The vicinity of the winding start (185a, 187a) of the wrap has a larger thickness at the boundary with the flat portion (184a, 186a) than the other portions of the wrap,
The scroll member according to claim 1. The volume of the sealed space (40) formed by meshing the fixed scroll member (124) and the movable scroll member (126) is continuously reduced by turning the movable scroll member to move into the sealed space. A scroll compressor (1) for compressing a sucked fluid,
At least one of the fixed scroll member and the movable scroll member is the scroll member according to claim 1 or 2.
Scroll compressor. The first surface (IS85a, IS87a) of the wrap is a surface that does not come into contact with a mating scroll member in relative movement of the fixed scroll member and the movable scroll member.
The scroll compressor according to claim 3. Surfaces other than the first surface of the wrap (OS185a, IS185b, OS185b, OS187a, IS187b, OS187b) have an inclination angle of substantially 0 ° with respect to a line orthogonal to the plane portion.
The scroll compressor according to claim 4. Surfaces other than the first surface of the wrap are subjected to cutting,
The first surface (IS85a, IS87a) of the lap is not cut.
The scroll compressor according to any one of claims 3 to 5. The scroll member is a member manufactured by injecting a material into a mold (81, 82) and then being subjected to the cutting process,
The wrap has a draft with respect to the mold after molding by the mold, and the cutting process is performed only on the surfaces other than the first surface and the first surface. To be
The scroll compressor according to claim 6. Compresses carbon dioxide,
The scroll compressor according to any one of claims 3 to 7.

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