JP5195774B2 - Scroll compressor - Google Patents

Description

  The present invention relates to a scroll compressor having a relief hole in a fixed scroll.

  Conventionally, in a scroll compressor, measures such as providing a relief hole in the end plate of the fixed scroll have been taken in order to release the overcompressed gas in the scroll compression chamber and reduce the overcompression loss. For relief holes, the larger the opening area, the better the escape of over-compressed gas.However, because of the relationship with the spiral wrap, there are spatial restrictions on the arrangement of the relief holes. A shape has been proposed.

  For example, in the scroll compressor described in Patent Document 1 (Japanese Patent No. 2551164), there are examples in which relief holes are formed as long holes along the shape of the movable scroll, or small holes are arranged along the lap of the fixed scroll. It is shown.

  In recent years, in order to realize a compressor that is environmentally friendly and achieves energy saving, the compressor has been downsized.

In addition, if a high-strength material such as an iron thixo material is used as the scroll component, it is also noticed that a scroll having a thin wrap can be made and the compressor can be miniaturized.
However, the relief hole for allowing the overcompressed gas to escape to the high-pressure space needs to be smaller than the tooth thickness of the wrap in order to prevent the adjacent compression chambers from communicating with each other, and it is difficult to increase the diameter of the relief hole. In addition, a scroll with a small tooth thickness of the wrap needs to reduce the diameter of the relief hole, and there is a problem that the gas passage through which the relief gas escapes becomes narrower.

  In order to solve this, as disclosed in Patent Document 1, a method is known in which a long hole having a radial length smaller than the tooth thickness of the wrap is formed along the spiral. In this method, the opening area is reduced. There is a problem that sufficient holes cannot be secured, and that long holes are complicated to machine and require high skill.

  There is also a method of arranging a plurality of relief holes having a diameter smaller than the tooth thickness of the wrap along the lap of the fixed scroll, but in this case, in order to enlarge the opening area as much as possible and wide the opening range with respect to the rotation angle. Therefore, the relief hole is often arranged in the vicinity of the lap.

  However, if a small-diameter relief hole is placed near the lap, the lubricating oil that forms an oil film on the lap surface will flow into the relief hole, causing the problem that the relief passage will be further narrowed and overcompressed gas will not escape. To do. In particular, a problem is likely to occur in a compressor that forcibly supplies oil to the compression chamber in order to achieve high efficiency.

  The subject of this invention is providing the scroll compressor which can ensure sufficient opening area of a relief hole, improves the omission of overcompressed gas, and can reduce an overcompression loss.

The scroll compressor of the first invention includes a fixed scroll and a movable scroll in which a spiral wrap is provided on one surface of each end plate. By combining the fixed scroll wrap and the movable scroll wrap with each other, a compression chamber is formed between the adjacent fixed scroll wrap and the movable scroll wrap. The end plate of the fixed scroll is formed with at least one relief hole penetrating the end plate so as to communicate with the compression chamber. The relief hole is formed at a position separated from the wrap of the fixed scroll. The relief hole is at least partially disposed in the closed region. When the movable scroll wrap reciprocates and passes through the relief hole when it makes one revolution , the closed region indicates the forward trajectory of the movable scroll wrap in plan view and the movable scroll lap in plan view. This is the overlapping part of the lap's backward trajectory.

  Here, a relief hole that can communicate with the compression chamber is formed through the end plate of the fixed scroll so as to penetrate the end plate, and each relief hole is formed at a position separated from the wrap of the fixed scroll, and the movable scroll in a plan view. Therefore, a sufficient opening area of the relief hole can be secured, and the overcompression gas can be easily removed to reduce the overcompression loss.

  A scroll compressor according to a second aspect is the scroll compressor according to the first aspect, wherein at least the center of the relief hole is disposed inside the closed region.

  Here, since at least the center of the relief hole is disposed inside the closed region, there is little gas leakage between the compression chambers adjacent through the relief hole.

  The scroll compressor of the third invention is the scroll compressor of the first invention or the second invention, and two or more relief holes are arranged along the longest diagonal line in the closed region.

  Here, since two or more relief holes are arranged along the longest diagonal line in the closed region, a sufficient opening area of the relief holes can be ensured, and overcompression gas can be easily removed to reduce overcompression loss.

  A scroll compressor according to a fourth aspect of the present invention is the scroll compressor according to any one of the first to third aspects, wherein the tip of the wrap of the movable scroll is chamfered. The diameter of the relief hole is larger than the tooth thickness at the chamfered tip of the movable scroll wrap and smaller than the tooth thickness at the center of the movable scroll wrap.

  Here, since the diameter of the relief hole is larger than the tooth thickness of the chamfered tip of the movable scroll wrap and smaller than the tooth thickness of the central portion of the movable scroll wrap, the opening area of the relief hole can be sufficiently secured, Moreover, the gap between the tip of the movable scroll wrap and the relief hole can be closed with an oil seal made of lubricating oil contained in the refrigerant gas, and gas leakage can be prevented.

  A scroll compressor according to a fifth aspect is the scroll compressor according to any one of the first to fourth aspects, wherein two or more relief holes are formed in the closed region. A common counterbore hole communicating with two or more relief holes formed in the closed region is formed on the back side of the end plate of the fixed scroll.

  Here, since a common counterbore hole communicating with two or more relief holes formed in the closed region is formed on the back side of the end plate of the fixed scroll, two or more relief holes are formed in the closed region. Even if it is arranged, the gas escapes through a counterbore hole having a larger diameter than the relief hole, so that the overcompressed gas escapes better.

  A scroll compressor according to a sixth aspect of the present invention is the scroll compressor according to the first aspect of the present invention, wherein the relief hole is a hole that opens to the entire closed region.

  Here, since the relief hole is a hole that opens to the entire range of the closed region, a relief hole with a large diameter can be obtained, a relief hole with a wider opening area can be secured, and the escape of overcompressed gas is even better Thus, the effect of reducing the overcompression loss is improved.

A scroll compressor according to a seventh aspect is the scroll compressor according to any one of the first to sixth aspects, wherein the closed region reciprocates with respect to the relief hole when the wrap of the movable scroll makes one revolution. When passing through, the area formed in the position where the area overlapping with the relief hole becomes the largest .

  Here, since the closed region is a region that becomes the maximum overlapping position when the orbiting scroll wrap makes a reciprocating motion once and reciprocates with respect to the relief hole, the adjacent compression chambers are connected by the relief hole. In addition to preventing problems, the maximum area of relief holes can be secured inside the closed area.

  The scroll compressor according to an eighth aspect of the present invention is the scroll compressor according to any one of the first to seventh aspects, wherein the closed region is a rhombus region in which each side is curved.

  Here, since the closed region is a rhombus region where each side is curved, it is possible to open a relief hole having a large diameter into the rhombus region, and gas leakage between adjacent compression chambers through the relief hole. Can also be reliably reduced.

  According to the first aspect of the present invention, the opening area of the relief hole can be sufficiently secured, the overcompression gas can be easily removed, and the overcompression loss can be reduced.

  According to the second invention, there is little gas leakage between the compression chambers adjacent through the relief holes.

  According to the third aspect of the present invention, a sufficient opening area of the relief hole can be secured, the overcompression gas can be easily removed, and the overcompression loss can be reduced.

  According to the fourth aspect of the present invention, a sufficient opening area of the relief hole can be secured, and the gap between the tip of the movable scroll wrap and the relief hole can be closed with an oil seal made of lubricating oil contained in the refrigerant gas. It is possible to prevent.

  According to the fifth aspect of the invention, even if two or more relief holes are arranged in the closed region, gas escapes through a counterbore hole having a larger diameter than the relief hole.

  According to the sixth aspect of the present invention, a relief hole having a large diameter can be obtained, a relief hole having a wider opening area can be secured, the overcompression gas can be more easily removed, and the effect of reducing the overcompression loss is improved.

  According to the seventh aspect of the present invention, it is possible to surely prevent a problem that adjacent compression chambers are communicated by the relief hole, and it is possible to ensure the maximum opening area of the relief hole inside the closed region.

  According to the eighth aspect of the present invention, it is possible to open a relief hole having a large diameter in the rhombic region, and it is possible to reliably reduce gas leakage between the compression chambers adjacent through the relief hole.

The longitudinal cross-sectional view of the scroll compressor concerning embodiment of this invention. The figure of the state which looked up at the fixed scroll of FIG. 1 from the downward direction. The figure which shows typically arrangement | positioning of the relief hole formed in the fixed scroll of FIG. The figure which shows the state which removed the cover body of the fixed scroll upper part of FIG. VV sectional view taken on the line of FIG. The expanded sectional view of the relief hole vicinity of the fixed scroll of FIG. Explanatory drawing which shows schematically the dimensional relationship between the relief hole of FIG. 1, and the lap | wrap of a movable scroll.

  Next, an embodiment of the scroll compressor of the present invention will be described with reference to the drawings.

Embodiment
Next, an embodiment of the scroll compressor of the present invention will be described with reference to the drawings.

  A scroll compressor 1 shown in FIG. 1 is a high and low pressure dome type scroll compressor, and constitutes a refrigerant circuit together with an evaporator, a condenser, an expansion mechanism, etc., and compresses gas refrigerant in the refrigerant circuit. It is mainly composed of a vertically long cylindrical sealed dome-shaped casing 10, a scroll compression mechanism 15, an Oldham ring 39, a drive motor 16, a lower main bearing 60, a suction pipe 19, and a discharge pipe 20. ing. Hereinafter, the components of the scroll compressor 1 will be described in detail.

[Details of components of scroll compressor 1]
(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 includes a housing 23, a fixed scroll 24 disposed in close contact with the housing 23, and a movable meshing with the fixed scroll 24. And a scroll 26.

  Hereinafter, the components of the scroll compression mechanism 15 will be described in detail.

a) Fixed Scroll As shown in FIGS. 1 to 5, the fixed scroll 24 is mainly composed of a flat end plate 24 a and a spiral (involute) wrap 24 b formed on the lower surface of the end plate 24 a. ing.

  A discharge port 41 communicating with a compression chamber 40 described later is formed in the end plate 24a so as to penetrate substantially the center of the end plate 24a. The discharge port 41 is formed so as to extend in the vertical direction at the central portion of the end plate 24a. The shape of the opening surface of the discharge port 41 is a non-circular shape in order to increase the opening area and reduce the discharge pressure loss. Further, a counterbore space 141 communicating with the discharge port 41 is formed on the upper surface of the end plate 24a. Further, an enlarged recess 42 (see FIG. 1) communicating with the discharge port 41 and the counterbore space 141 is formed on the upper surface of the end plate 24a. The enlarged concave portion 42 is constituted by a concave portion that is provided in the upper surface of the end plate 24a and that extends in the horizontal direction. A lid 44 is fastened and fixed to the upper surface of the fixed scroll 24 by bolts 44 a so as to close the enlarged concave portion 42. And the muffler space 45 which consists of an expansion chamber which silences the driving | running | working sound of the scroll compression mechanism 15 by covering the expansion recessed part 42 with the cover body 44 is formed. The fixed scroll 24 and the lid 44 are sealed by being brought into close contact via a packing (not shown).

  Also, as shown in FIGS. 2 to 4 and FIG. 6, four pairs of round hole-shaped relief holes 61 are formed through the end plate 24 a of the fixed scroll 24 by two. Specifically, the relief hole 61 is disposed so that the compression chamber 40 passes through the four relief holes 61 for each compression process from suction to discharge.

  As shown in FIG. 2, the relief hole 61 is formed at a position separated from the wrap 24 b of the fixed scroll 24.

  Further, as shown in FIG. 3, the relief hole 61 is a closed region that is an overlapping portion of the locus of the wrap 26b of the movable scroll 26 in a plan view, that is, a rhombus region in which each side is curved in this embodiment. Two are arranged inside 62. As a result, a sufficient opening area of the relief passage 70 can be secured, and the escape of the overcompressed gas is improved.

  In this diamond-shaped region 62, as shown in FIG. 3, the wrap 26b of the movable scroll 26 (the reciprocating wrap 26b is 26b1 for the forward direction and 26b2 for the backward direction) makes one revolution. This is the region that is the maximum overlap position when reciprocally passing through the relief hole 61. As a result, it is possible to reliably prevent the adjacent compression chamber 40 from being communicated by the relief hole 61, and to ensure the maximum opening area of the relief hole 61 inside the diamond-shaped region 62.

  The position of the relief hole 61 may be such that at least the center of the relief hole 61 is disposed inside the rhombic region 62.

  In addition, two or more relief holes 61 are arranged along the longer diagonal line 63 in the rhombic region 62, so that the opening area of the relief passage 70 can be sufficiently secured. The diagonal line 63 may be slightly curved in accordance with the degree of curvature of the rhombus region 62.

  Further, as shown in FIG. 7, the diameter D1 of each relief hole 61 is larger than the tooth thickness T1 of the chamfered tip 64 of the wrap 26b of the movable scroll 26 and the central portion of the wrap 26b of the movable scroll 26. Is set to be smaller than the tooth thickness T0. In this case, even when the wrap 26b is in a position overlapping the relief hole 61, the lap 26b communicates for a moment, but is closed by the lubricating oil contained in the refrigerant gas and can be covered with an oil seal. For example, if the tooth thickness T1 at the tip of the wrap 26b of the movable scroll 26 is 1.5 to 1.7 mm and the center tooth thickness T0 is about 2.1 to 2.3 mm, the diameter D1 of the relief hole 61 is 1 What is necessary is just to set to about 9-2.1 mm.

  Further, as shown in FIGS. 4 and 6 to 7, a common counterbore hole 65 communicating with each of the two relief holes 61 is formed on the back surface side (near the upper surface) of the end plate 24 a. Also, as shown in FIG. 6, a relief passage 70 that penetrates the end plate 24 a of the fixed scroll 24 is formed by the relief hole 61 and the counterbore hole 65.

  Further, as shown in FIGS. 1 and 4 to 6, a relief valve 66, which is a check valve for closing each counterbore 65, is provided on the inner surface of the enlarged recess 42 on the upper surface of the end plate 24 a of the fixed scroll 24, and its A relief valve presser 67 is provided for limiting the opening of the relief valve 66 to a predetermined opening or less.

  When the relief hole 61 is formed, the relief hole 61 is formed by finishing the surface of the end plate 24a of the fixed scroll 24 on which the lap 24b is formed (so-called tooth bottom finishing) after the relief hole 61 is formed. It is possible to remove the burrs that sometimes occur.

  When the relief passage 70 penetrating the end plate 24a is formed, first, the relief hole 61 is processed from the formation surface side of the end plate 24b of the end plate 24a to the middle of the end plate 24a, and then a large-diameter seat from the rear side. If the hole 65 is penetrated by forming the counterbore 65, burrs generated on the back side of the end plate 24a when the relief hole 61 is formed can be removed, and processing errors can be absorbed.

b) Movable Scroll As shown in FIG. 1, the movable scroll 26 is mainly formed on the end plate 26a, a spiral (involute) wrap 26b formed on the upper surface of the end plate 26a, and the lower surface of the end plate 26a. The bearing portion 26c and groove portions 26d formed at both ends of the end plate 26a.

  The movable scroll 26 is an outer drive movable scroll. That is, the movable scroll 26 has a bearing portion 26 c that fits outside the drive shaft 17.

  The movable scroll 26 is supported by the housing 23 by fitting an Oldham ring 39 into the groove 26d. Further, the upper end of the drive shaft 17 is fitted into the bearing portion 26c. The movable scroll 26 revolves in 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 26b of the movable scroll 26 is meshed with the wrap 24b of the fixed scroll 24, and a compression chamber 40 is formed between the contact portions of both the wraps 24b and 26b. In the compression chamber 40, the volume between the laps 24b and 26b contracts toward the center as the movable scroll 26 revolves. In the scroll compressor 1 according to the present embodiment, the gas refrigerant is compressed in this way.

c) 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 part 11 and the housing 23 are in close contact with each other in an airtight manner 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. In addition, the fixed scroll 24 is fixed to the housing 23 with a bolt or the like so that the upper end surface is in close contact with the lower end surface of the fixed scroll 24. 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.

d) Others In the scroll compression mechanism 15, a communication passage 46 is formed across the fixed scroll 24 and the housing 23. The communication passage 46 is formed so that a scroll-side passage 47 formed in the fixed scroll 24 and a housing-side passage 48 formed in the housing 23 communicate with each other. The upper end of the communication passage 46 opens into 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 into the lower end surface of the housing 23. In other words, the lower end opening of the housing side passage 48 constitutes a discharge port 49 through which the refrigerant in the communication passage 46 flows out into the gap space 18.

(3) Oldham ring The Oldham ring 39 is a member for preventing the rotational movement of the movable scroll 26 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 brushless DC motor in the present embodiment, and mainly includes an annular stator 51 fixed to the inner wall surface of the casing 10 and a slight gap (air gap) inside the stator 51. The rotor 52 is rotatably accommodated with a passage). 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 26 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 that has flowed out of 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 24.

(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 is opened at a position protruding downward from the inner surface of the body toward the center, and communicates with the gap space 18 that is the high-pressure space 28.

[Operation of scroll compressor 1]
Next, the operation of the scroll compressor 1 will be briefly described with reference to FIG. First, when the drive motor 16 is driven, the drive shaft 17 rotates and the revolving operation is performed without the movable scroll 26 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 to the muffler space 45 through the discharge port 41 and the counterbore space 141. When overcompressed gas is generated inside the compression chamber 40 (when the internal pressure of the compression chamber 40 is equal to or higher than the valve closing pressure of the relief valve 66), the overcompressed gas is discharged to the muffler space 45 through the relief passage 70. . Thereafter, the fluid flows out to the gap space 18 through the communication passage 46 (that is, the scroll side passage 47 and the housing side passage 48) and the discharge port 49, and the space between the guide plate 58 and the inner surface of the body casing portion 11 is lowered. It flows toward. 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. The lubricating oil flowing in the direction and 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 join in the gap space 18 and are discharged from the discharge pipe 20 to the outside of 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.

[Forced refueling and relief arrangement]
Here, there are a rated point and APF as compressor efficiency to be improved in order to realize an energy-saving compressor that is good for the environment.

  The rated point is a point of relatively high differential pressure and high speed, and the point where the contribution ratio is high in APF, which is the point of high annual operating efficiency, is the low compression ratio and low speed.

  Since it is important to reduce the leakage loss in order to improve the rating point, it is necessary to increase the amount of lubricating oil injected into the compression chamber 40.

  In order to improve the APF performance, it is important to reduce the overcompression loss because of low compression. Therefore, a relief passage 70 is provided before the gas is discharged from the discharge port 41, and the overcompressed gas is discharged to the high pressure space. There is a need to.

  Here, since the position of the relief hole 61 is fixed, the relief valve 66 opens at a fixed compression ratio, but the compression ratio at which overcompression occurs varies depending on the operating conditions.

  Therefore, it is usually considered that the relief hole 61 is arranged in accordance with the operating condition with the highest APF contribution rate.

  Therefore, if the relief hole 61 is formed in the vicinity of the lap 24b of the fixed scroll 24, it can be opened over a wide range, and other operating conditions can be covered.

  When the relief hole 61 is arranged between the wrap 24b1 of the fixed scroll 24 and the wrap 24b2 on the inner circumference side of the fixed scroll 24, the opening range is narrow, and the compression chamber on the inner circumference side of the wrap 26b of the movable scroll 26 There is a risk that gas may be transferred between the compression chamber on the outer peripheral side (so-called between the A chamber and the B chamber), but the number of holes can be reduced because the AB chamber can be used as a hole.

  In the present embodiment, in consideration of these points, the relief hole 61 is at a position spaced from the wrap 24b of the fixed scroll 24 so that no gas is transferred between adjacent compression chambers, and The movable scroll 26 is arranged in a rhombus region 62 where each side which is an overlapping portion of the locus of the lap 26b of the movable scroll 26 is curved. As a result, the number of relief holes 61 can be reduced and a large-diameter relief hole 61 can be provided.

<Features of the embodiment>
(1)
In the scroll compressor 1 according to the embodiment, four sets of relief holes 61 that can communicate with the compression chamber 40 are formed in the end plate 24a of the fixed scroll 24 through the end plate 24a. Each relief hole 61 is formed at a position separated from the lap 24b of the fixed scroll 24, and a rhombus region 62 in which each side which is an overlapping portion of the locus of the lap 26b of the movable scroll 26 in a plan view is curved. Is arranged. For this reason, the opening area of the relief hole 61 can be secured sufficiently, the escape of overcompressed gas can be improved, and the overcompression loss can be reduced.

(2)
In addition, since the opening area of the relief hole 61 can be sufficiently secured in this way, the relief passage 70 is not blocked with oil even when the amount of oil injected into the compression chamber 40 is large, and the overcompression loss can be effectively reduced.

(3)
That is, the scroll compressor 1 of the present embodiment is suitable for a small scroll compressor having a scroll having a thin tooth thickness, and by arranging the relief hole 61 inside the rhombic region 62, a sufficient relief flow rate can be obtained. Can be secured, and low-speed performance is improved.

  Moreover, even when the scroll compressor 1 is operated at high speed, there is an advantage that there is little leakage between the adjacent compression chambers 40 through the relief holes 61. Therefore, low speed performance can be improved while maintaining high speed performance.

(4)
Furthermore, the scroll compressor 1 according to the present embodiment has a simple structure in which a plurality of round hole-shaped relief holes 61 are formed in the rhombic region 62, and thus the productivity is good.

(5)
Furthermore, in the scroll compressor 1 of this embodiment, the position of the relief hole 61 is such that at least the center of the relief hole 61 is disposed inside the rhombic region 62, so that the compression chamber adjacent through the relief hole 61 is located. There is little gas leakage between 40.

(6)
Furthermore, in the scroll compressor 1 of the present embodiment, two or more relief holes 61 are arranged along the longest diagonal line 63 in the rhombus region 62, so that a sufficient opening area of the relief holes 61 is ensured. It is possible to improve the escape of overcompressed gas and reduce overcompression loss.

(7)
Furthermore, in the scroll compressor 1 of the present embodiment, the tip 64 of the wrap 26a of the movable scroll 26 is further chamfered, and the diameter D1 of the relief hole 61 is chamfered at the tip 64 of the wrap 26a of the movable scroll 26. Is larger than the tooth thickness T1 of the movable scroll 26 and smaller than the tooth thickness T0 of the central portion of the wrap 26a of the movable scroll 26, so that a sufficient opening area of the relief hole 61 can be secured, and an oil seal with lubricating oil contained in the refrigerant gas can be used. The gap between the tip of the wrap 26a of the movable scroll 26 and the relief hole 61 can be closed, and gas leakage can be prevented.

(8)
Furthermore, in the scroll compressor 1 of the present embodiment, two or more relief holes 61 are formed in the diamond-shaped region 62 that is a closed region. On the back side of the end plate 24 a of the fixed scroll 24, a common counterbore hole 65 communicating with the two or more relief holes 61 formed in the rhombic region 62 is formed. For this reason, even if two or more relief holes 61 are arranged in the diamond-shaped region 62, gas escapes through the counterbore hole 65 having a larger diameter than the relief hole 61, so that the overcompressed gas can be easily removed.

  In addition, since the relief valve 66 may be provided for each common counterbore 65, the number of relief valves 66 can be reduced.

(9)
Furthermore, in the scroll compressor 1 of the present embodiment, the diamond-shaped region 62 is the maximum overlapping position when the wrap 26a of the movable scroll 26 reciprocates with respect to the relief hole 61 when making a revolving motion once. It is an area. Accordingly, it is possible to reliably prevent the adjacent compression chamber 40 from being communicated by the relief hole 61, and to ensure the maximum opening area of the relief hole inside the rhombic region 62.

(10)
In the scroll compressor 1 of the embodiment, as a region for providing the relief hole 61, a rhombus region in which each side is curved in a closed region that is an overlapping portion of the locus of the wrap 26b of the movable scroll 26 in a plan view. 62. Accordingly, it is possible to open the relief hole 61 having a larger diameter in the rhombic region 62 than in the case where a plurality of relief holes are formed in the vicinity of the wrap of the fixed scroll as in the prior art, and the adjacent compression through the relief hole 61. Gas leakage between the chambers 40 can also be reliably reduced.

  Further, the arrangement of the relief holes 61 can be easily determined from the position, shape, and arrangement of the rhombic region 62.

<Modification of Embodiment>
(A)
In the scroll compressor 1 of the embodiment, an example in which a plurality of round hole-shaped relief holes 61 are formed in the rhombic region 62 is shown, but the present invention is not limited to this, and various shapes are used. It is also possible to form a relief hole 61. As a modification of the present invention, for example, the relief hole 61 may be a rhombus hole that opens in the entire range of the rhombus region 62. In this case, a relief hole having a large diamond shape can be obtained, and a relief hole having a wider opening area can be secured. As a result, the escape of the overcompression gas is further improved, and the effect of reducing the overcompression loss is improved.

(B)
Moreover, you may manufacture the fixed scroll 24 and the movable scroll 26 using high strength materials, such as an iron thixo material. In this case, downsizing of the scroll component can be achieved and the thickness of each wrap can be reduced, but in this case as well, the wrap 26b of the movable scroll 26 such as the diamond-shaped region 62 as in the above-described embodiment. If the relief hole 61 is formed in the closed region of the overlapping portion of the locus, the above-described effect can be obtained.

(C)
Further, the fixed scroll 24 and the movable scroll 26 may be made of different materials. Also in this case, downsizing can be achieved, the wrap thickness can be reduced, and the above-described effects can be achieved.

(D)
Furthermore, in the scroll compressor 1 of the embodiment, the diameters of the plurality of round hole-shaped relief holes 61 are not particularly limited. For example, according to the tooth thickness of the wrap of the fixed scroll 24 and / or the movable scroll 26. The diameter of the relief hole 61 may be changed and set.

  For example, when the tooth thickness of the wrap 24b of the fixed scroll 24 is smaller on the inlet side (outer peripheral side) than on the outlet side (center side), the diameter of the relief hole 61 is also corresponding to the inlet side (outer peripheral side). ) May be set small and the exit side (center side) may be set large.

(E)
Further, the relief hole 61 is arranged adjacent to the fixed scroll 24 in order to set one opening angle of the compression chamber 40 adjacent to the wrap 24b of the fixed scroll 24 to the suction side or to widen the opening angle range. You may arrange | position so that it may be biased to the outer peripheral side or the inner peripheral side from the center between the lap | wraps 24b.

  The present invention can be variously applied to a scroll compressor having a relief hole.

1 Scroll compressor 24 Fixed scroll 24a End plate 24b Wrap 26 Movable scroll 26a End plate 26b Wrap 40 Compression chamber 61 Relief hole 62 Rhombus region (closed region)
63 Diagonal line 65 Counterbore hole 66 Relief valve 70 Relief passage

Japanese Patent No. 2551164

Claims (8)

A fixed scroll (24) and a movable scroll (26) provided with a spiral wrap (24b, 26b) on one surface of each end plate (24a, 26a);
The wrap (24b) of the fixed scroll (24) and the wrap (26b) of the movable scroll (26) are combined with each other, whereby the wrap (24b) of the adjacent fixed scroll (24) and the movable scroll (26) are combined. ) Is formed between the wrap (26b) and a compression chamber (40),
In the end plate (24a) of the fixed scroll (24), at least one relief hole (61) that can communicate with the compression chamber (40) is formed through the end plate (24a).
The relief hole (61) is formed at a position spaced from the wrap of the fixed scroll (24), and at least a part thereof is disposed in the closed region (62) ,
When the wrap (26b) of the movable scroll (26) reciprocates and passes through the relief hole (61) when the wrap (26b) of the movable scroll (26) makes one revolution, the closed region (62) The trajectory (26b1) in the forward direction of the wrap (26b) of the scroll (26) and the trajectory (26b2) in the backward direction of the wrap (26b) of the movable scroll (26) in plan view are overlapping portions.
Scroll compressor (1). At least the center of the relief hole (61) is located inside the closed region (62);
The scroll compressor (1) according to claim 1.   The scroll compressor (1) according to claim 1 or 2, wherein two or more relief holes (61) are arranged along a longest diagonal line in the closed region (62). The tip of the wrap of the movable scroll (26) is chamfered,
The diameter of the relief hole (61) is larger than the tooth thickness of the chamfered tip of the wrap (26b) of the movable scroll (26) and smaller than the tooth thickness of the central portion of the wrap of the movable scroll (26). ,
The scroll compressor (1) according to any one of claims 1 to 3. Two or more relief holes (61) are formed in the closed region (62),
A common counterbore hole (65) communicating with the two or more relief holes (61) formed in the closed region (62) is formed on the back side of the end plate (24a) of the fixed scroll (24). Being
The scroll compressor (1) according to any one of claims 1 to 4. The relief hole (61) is a hole that opens to the entire range of the closed region (62).
The scroll compressor (1) according to claim 1. The closed area (62), when passing back and forth relative to the relief hole (61) when the wrap (26b) of the movable scroll (26) rotates one round revolves, said relief hole (61 ) Is a region formed at a position where the area overlapping with
The scroll compressor (1) according to any one of claims 1 to 6. The closed region is a rhombic region (62) with curved sides.
The scroll compressor (1) according to any one of claims 1 to 7.

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