JP2014015883A - Hermetic type compressor - Google Patents

Abstract

An object of the present invention is to reduce the re-expansion amount of the residual working fluid by reducing the residual working fluid remaining in the compression chamber at the top dead center position of the piston, thereby improving the volume efficiency.
A cylinder is provided by providing a slit groove 61 communicating with a discharge hole 19 formed on the outer periphery of a suction reed valve 20 and a communication groove 64 communicating the slit groove 61 with an inner peripheral surface 14b of a cylinder 14. Since the working fluid 3 remaining on the inner peripheral surface 14b of 14 can be reduced and the re-expansion amount of the remaining working fluid 3 can be suppressed, the volumetric efficiency and the efficiency of the hermetic compressor can be improved.
[Selection] Figure 4

Description

  The present invention relates to a hermetic compressor used for a refrigeration cycle apparatus such as a refrigerator, an air compressor, and the like.

  In recent years, in order to protect the global environment, the demand for energy saving has been increasing, and even in compressors used in refrigerators and other refrigeration cycle devices and air compressors used in industrial fields, etc. There is a strong demand for efficiency.

  Conventionally, as this type of hermetic compressor, there is one in which a concave portion is formed on the top surface of a piston that reciprocates in a cylinder to improve efficiency (for example, see Patent Document 1).

  7 is a cross-sectional view of the conventional hermetic compressor described in Patent Document 1, FIG. 8 is a plan view from the top side of the piston of the conventional hermetic compressor, and FIG. 9 is a conventional hermetic type. It is an expanded sectional view of the cylinder principal part of a compressor.

  As shown in FIGS. 7 to 9, the hermetic compressor stores an oil 102 at the bottom and is filled with a working fluid 103 in a hermetic container 101, and further stores a compressor main body 104. The compressor body 104 is elastically supported in the sealed container 101 by a suspension spring 105.

  The compressor body 104 includes an electric element 106 and a compression element 109 that is rotationally driven by the electric element 106. The compression element 109 is disposed below the electric element 106, and the electric element 106 includes a stator 107 and a rotor 108.

  The compression element 109 includes a crankshaft 112 having an eccentric shaft 110 and a main shaft 111, a cylinder 114 that forms a compression chamber 113, and a block 115 that integrally forms a bearing portion 123 that supports the main shaft 111, and a cylinder 114. A piston 116 that reciprocates inside, a valve plate 117 that seals the end surface of the cylinder 114, and a suction hole (not shown) and a discharge hole 119 that are provided in the valve plate 117 and communicate with the inside and outside of the compression chamber 113 are opened and closed. A suction valve 120, a discharge valve 121, and a connecting means 122 for connecting the eccentric shaft 110 and the piston 116 are provided.

  A cylinder head 128 is disposed on the side of the anti-compression chamber 113 of the valve plate 117 so as to cover and cover the valve plate 117, and a head space 129 is formed by the valve plate 117 and the cylinder head 128.

  The main shaft 111 of the crankshaft 112 is rotatably supported by the bearing portion 123 of the block 115, and the rotor 108 is fixed.

  As shown in FIGS. 8 to 9, a recess 125 is formed in the top surface 124 of the piston 116, and at least a part of the recess 125 overlaps a part of the discharge hole 119, and the surface other than the recess 125 of the top surface 124. 126 is flat and parallel to the surface of the valve plate 117 on the compression chamber 113 side.

  Next, the operation of the conventional hermetic compressor will be described.

  The hermetic compressor causes a current to flow through the stator 107 to generate a magnetic field, and rotates the rotor 108 fixed to the main shaft 111, whereby the crankshaft 112 rotates and the connecting means 122 attached to the eccentric shaft 110. , The piston 116 reciprocates in the cylinder 114 and repeats a series of cycles of suction, compression, and discharge strokes.

  When the piston 116 moves in the direction in which the volume of the cylinder 114 increases in the suction stroke, the working fluid 103 in the compression chamber 113 expands, and the pressure in the compression chamber 113 increases the pressure on the low pressure side (not shown) of the refrigeration cycle. When the pressure falls below, the suction valve 120 starts to open, and the low-temperature working fluid 103 returned from the refrigeration cycle flows into the compression chamber 113 through a suction hole (not shown).

  In the compression stroke, when the piston 116 turns from the position of the bottom dead center where the volume of the compression chamber 113 is maximized to the direction of decreasing the volume in the compression chamber 113, the pressure in the compression chamber 113 increases and the compression is performed. Due to the difference between the pressure in the chamber 113 and the pressure on the low pressure side (not shown) of the refrigeration cycle, the suction valve 120 is closed and the compression chamber 113 is closed.

  Thereafter, when the piston 116 further moves in the direction of decreasing the volume of the compression chamber 113, the working fluid 103 is compressed and pressurized to a predetermined pressure.

  In the discharge stroke, when the pressure of the working fluid 103 in the compression chamber 113 increases and becomes higher than the pressure in the head space 129 formed by the valve plate 117 and the cylinder head 128, the discharge valve 121 starts to open due to the pressure difference, The working fluid 103 inside the compression chamber 113 passes through the discharge hole 119 and flows out to the head space 129. Thereafter, the working fluid 103 is discharged from the head space 129 to the high pressure side (not shown) of the refrigeration cycle via the discharge muffler (not shown).

  Further, in the discharge stroke, when the top surface 124 of the piston 116 is closest to the valve plate 117 and is located at a top dead center that minimizes the volume of the compression chamber 113, a recess 125 is formed in the top surface 124 of the piston 116. Therefore, the clearance of the space 127 between the valve plate 117 and the recess 125 is widened, and the passage cross-sectional area of the working fluid 103 that flows across the space 127 from the top surface 124 of the piston 116 and flows to the discharge hole 119 is ensured. Therefore, the flow of the working fluid 103 is improved, and the compression efficiency of the hermetic compressor can be improved.

Japanese Patent Publication No. 8-6689

  However, in the above-described conventional configuration, since the concave portion 125 is provided in the piston 116, when the piston 116 is located at the top dead center, the working fluid 103 that remains without being discharged increases, and the remaining working fluid 103 remains. However, since the volumetric efficiency is reduced due to re-expansion in the suction stroke, there is a problem that the effect of improving the flow of the working fluid 103 in the formation of the recess 125 is offset.

  The present invention solves the above-described conventional problems, and reduces the residual working fluid in the compression chamber at the top dead center position of the piston, thereby reducing the re-expansion of the remaining working fluid during the suction stroke and increasing the volume efficiency. An object of the present invention is to provide a hermetic compressor with improved efficiency.

  In order to solve the above conventional problems, the hermetic compressor of the present invention has a suction hole at a substantially plane symmetrical position with respect to the discharge hole of the valve plate, and the suction valve seat opens and closes the suction hole. The valve has a slit groove formed on the outer periphery of the suction reed valve and communicating with the discharge hole, and a communication groove communicating the slit groove and the inner peripheral surface of the cylinder.

  As a result, the working fluid existing near the inner peripheral surface of the compression chamber at the position near the top dead center of the piston during the compression stroke flows smoothly from the communication groove to the discharge hole side through the slit groove having a small flow resistance. Residue near the suction side inner peripheral surface of the chamber is suppressed. Further, by forming the discharge flow path using the slit groove, the re-expansion of the residual working fluid is reduced, and the volumetric efficiency of the hermetic compressor can be improved. Moreover, since the overcompression resulting from the retention of the working fluid near the inner peripheral surface of the compression chamber can be suppressed, the compressor input can also be reduced.

  The present invention can improve the efficiency of a hermetic compressor, and therefore can provide a hermetic compressor that achieves high efficiency and energy saving.

1 is a longitudinal sectional view of a hermetic compressor according to Embodiment 1 of the present invention. The exploded perspective view of the compression element of the hermetic compressor in Embodiment 1 Top view of suction valve seat of hermetic compressor according to Embodiment 1 Sectional drawing of the principal part by the AA line shown in FIG. 1 of the hermetic compressor in Embodiment 1 (A) Schematic diagram explaining the middle of the suction stroke of the hermetic compressor in the first embodiment, (b) Schematic diagram explaining the end of the suction stroke of the hermetic compressor (near bottom dead center), (c) ) Schematic diagram explaining the middle of the compression stroke of the hermetic compressor, (d) Schematic diagram explaining the discharge stroke (near top dead center) of the hermetic compressor The top view of the suction reed valve assembly part of the hermetic compressor in Embodiment 2 of the present invention Cross section of a conventional hermetic compressor Plan view from the top side of the piston of a conventional hermetic compressor Expanded sectional view of the main part of a cylinder of a conventional hermetic compressor

  1st invention accommodates the electric element in the airtight container, and the compression element driven by the said electric element, The said compression element has a cylinder block provided with the cylinder, The piston which reciprocates in the said cylinder, The gasket includes a gasket that is disposed at an open end of the cylinder block and forms a compression chamber by the cylinder and the piston, a valve seat, and a valve plate, and the valve plate has a substantially surface with respect to the discharge hole and the discharge hole. The valve seat has a suction hole at a symmetric position, the valve seat is configured to open and close the suction hole, a slit groove formed on an outer periphery of the suction lead valve and communicating with the discharge hole, the slit groove, and the cylinder The piston has a communication groove that communicates with the inner peripheral surface of the cylinder, and the piston exists near the inner peripheral surface of the compression chamber at the position near the top dead center during the compression stroke. Dynamic fluid flows smoothly from the communicating groove to the flow path smaller along the slit groove discharge hole side resistance, residual near the suction side inner peripheral surface of the compression chamber is suppressed. In addition, since the amount of re-expansion of the residual working fluid is reduced by using the slit groove to form the discharge flow path, the volumetric efficiency of the hermetic compressor can be improved. Can be improved.

The second invention is provided with a plurality of communication grooves of the suction valve seat, and is present near the inner peripheral surface of the compression chamber near the top dead center during the compression stroke in which the piston operates from the bottom dead center to the top dead center. The working fluid smoothly flows from the plurality of communication grooves to the discharge hole side through the slit groove, and further, the residual on the inner peripheral surface of the compression chamber is suppressed, so that the compressor input can also be reduced and sealed. The efficiency of the mold compressor can be improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a longitudinal sectional view of a hermetic compressor according to Embodiment 1 of the present invention. FIG. 2 is an exploded perspective view of a compression element of the hermetic compressor according to the first embodiment. FIG. 3 is a plan view of the suction valve seat of the hermetic compressor according to the first embodiment. 4 is a cross-sectional view of the main part taken along line AA shown in FIG. 1 of the hermetic compressor according to the first embodiment. 5A and 5B are schematic diagrams for explaining the operation of the hermetic compressor according to the first embodiment. FIG. 5A shows the middle of the suction stroke, FIG. 5B shows the end of the suction stroke (near the bottom dead center), c) shows the middle of the compression stroke, and (d) shows the discharge stroke (near top dead center).

  1 to 5, the hermetic compressor stores oil 2 at the bottom of the hermetic container 1, and a hydrocarbon-based refrigerant having a low global warming potential such as R600a is sealed as the working fluid 3. Yes.

  In addition, the sealed container 1 is formed by drawing a steel plate, and further, a suction pipe 50 having one end communicating with the sealed container 1 and the other end connected to the low pressure side (not shown) of the refrigeration cycle, and A discharge pipe 57 having one end passing through the sealed container 1 and communicating with a discharge muffler (not shown) and connected to the high pressure side (not shown) of the refrigeration cycle is provided.

  In the sealed container 1, a compressor main body 4 including a compression element 9 and an electric element 6 that drives the compression element 9 is accommodated. The compressor body 4 is elastically supported with respect to the sealed container 1 by a suspension spring 5.

  The compression element 9 includes a crankshaft 12, a cylinder block 15, a piston 16, connection means 22, and the like. The crankshaft 12 includes an eccentric shaft 10 and a main shaft 11, and an oil supply mechanism 51 including a spiral groove is provided on the surface of the main shaft 11.

  The electric element 6 includes a stator 7 screwed by a bolt (not shown) below the cylinder block 15 and a rotor 8 disposed inside the stator 7 and shrink-fitted to the main shaft 11.

  The cylinder block 15 is integrally formed with a cylinder 14 that forms the compression chamber 13 and a bearing portion 23 that rotatably supports the main shaft 11.

  Further, on the end surface 14a of the cylinder 14, a valve plate 17 having a suction hole 18 and a discharge hole 19 communicating with the inside and outside of the compression chamber 13, a suction valve seat 60 made of thin plate steel, the end surface 14a of the cylinder 14 and the valve The gasket 63 that is sandwiched between the seats 60 to prevent the working fluid 3 from leaking from the compression chamber 13 and the cylinder head 52 that covers the valve plate 17 both seal the end surface 14 a of the cylinder 14 with the head bolt 53. It is fixed to.

  The suction valve seat 60 is formed with a suction reed valve 20 that is provided with a slit groove 61 so that the suction hole 18 of the valve plate 17 can be opened and closed.

  The gasket 63 prevents the reciprocating piston 16 from coming into contact with the suction valve seat 60 at the top dead center, and manages the clearance between the suction valve seat 60 and the piston 16 so as to keep it below a certain value. A shape having a relief hole 65 (inner diameter of 26 mm in this embodiment) larger than the outer diameter of piston 16 (25 mm in this embodiment) and a thickness of 0.2 to 0.5 mm (in this embodiment 0.35 mm) Are using things.

  Further, a suction muffler 54 is gripped and fixed between the valve plate 17 and the cylinder head 52. The valve plate 17 has a discharge valve 21 that opens and closes the discharge hole 19 fixed to a surface facing the cylinder head 52, and a head space 56 is formed between the valve plate 17 and the cylinder head 52.

  Further, the valve plate 17 has a suction hole 18 at a substantially plane symmetrical position with respect to the discharge hole 19. The suction valve seat 60 has a thickness of 0.1 to 0.3 mm (0.2 mm in this embodiment), and a slit groove 61 (groove width of 1 mm in this embodiment) formed on the outer periphery of the suction reed valve 20. The discharge hole 19 has a communication shape, and has a communication groove 64 that connects the slit groove 61 and the inner peripheral surface 14 b of the cylinder 14. The communication groove 64 is substantially plane-symmetric with respect to the discharge hole 19. Is arranged.

  Next, the operation and action of the hermetic compressor having the above configuration will be described.

  In the hermetic compressor, the crankshaft 12 is rotated by causing a current to flow through the stator 7 to generate a magnetic field and rotating the rotor 8 fixed to the main shaft 11. Along with this, the piston 16 reciprocates in the cylinder 14 via the connecting means 22 rotatably attached to the eccentric shaft 10.

  As the piston 16 reciprocates, the working fluid 3 is sucked into the compression chamber 13 through the suction muffler 54, compressed, and then discharged from the discharge hole 19, and passes through the head space 56 to be a refrigeration cycle (see FIG. (Not shown).

  Next, suction, compression, and discharge strokes of the working fluid 3 by the compressor body 4 will be described with reference to FIG.

  In the intake stroke, as shown in FIG. 5A, the piston 16 operates in the direction of the arrow x that increases the volume of the compression chamber 13, whereby the working fluid 3 in the compression chamber 13 expands, The pressure drops. When the pressure in the compression chamber 13 falls below the pressure in the suction muffler 54, the suction valve 20 opens due to the difference between the pressure in the compression chamber 13 and the pressure in the suction muffler 54. Accordingly, the low-temperature working fluid 3 returned from the refrigeration cycle is once opened from the suction pipe 50 into the sealed container 1 and then flows into the compression chamber 13 through the suction muffler 54.

  Thereafter, in the compression stroke, as shown in FIG. 5B, when the operation of the piston 16 turns from the bottom dead center in the direction of the arrow y in which the volume of the compression chamber 13 decreases, the pressure in the compression chamber 13 increases and the compression is performed. The suction valve 20 is closed by the difference between the pressure in the chamber 13 and the pressure in the suction muffler 54. Along with this, the compression chamber 13 is closed, and the piston 16 operates in a direction in which the volume of the compression chamber 13 further decreases, so that the working fluid 3 is compressed as shown in FIG. The pressure is increased to.

In the discharge stroke, when the pressure of the working fluid 3 in the compression chamber 13 increases and becomes higher than the pressure in the head space 56 formed by the valve plate 17 and the cylinder head 52, as shown in FIG. Due to the pressure difference, the discharge valve 21 starts to open. as a result,
The working fluid 3 inside the compression chamber 13 passes through the discharge hole 19 and flows out to the head space 56.

  By repeating these suction / compression cycles, the working fluid 3 continuously passes from the head space 56 via the discharge muffler (not shown) to the high pressure side (not shown) of the refrigeration cycle through the discharge pipe 57. Flowing into.

  On the other hand, at the top dead center position of the piston 16, a clearance of 0.05 to 0.1 mm (0.08 mm in this embodiment) is provided between the top surface 16a of the piston 16 and the valve seat 60 in order to avoid collision between the two. ) Is formed, and this clearance leaves a minute volume called dead volume in the compression chamber 13. Similarly, the space formed by the escape hole 65 of the gasket 63, the end surface 14a of the cylinder 14 and the side surface of the piston 16 is also a dead volume in the compression chamber 13. Furthermore, the space in the slit groove 61 of the suction valve seat 60 is also dead volume.

  These dead volumes cause the working fluid 3 inside the compression chamber 13 to remain in the compression stroke, and the remaining working fluid 3 re-expands in the suction stroke, thereby reducing the amount of the working fluid 3 flowing in and improving the volume efficiency. Reduce.

  Further, in the vicinity of the top dead center of the compression stroke, when the clearance between the top surface 16a of the piston 16 and the suction valve seat 60 becomes narrow, the resistance that the working fluid 3 flows to the discharge hole 19 increases. Therefore, the working fluid 3 forms a discharge channel while bypassing the dead volume in the slit groove 61 of the suction valve seat 60 having a relatively large channel area and the dead volume of the escape hole 65 of the gasket 63 to form a discharge hole. 19 is discharged.

  At this time, the configuration of the hermetic compressor in the first embodiment includes a communication groove 64 that communicates the slit groove 61 of the suction valve seat 60 and the inner peripheral surface 14b of the cylinder 14, so that the top dead center of the compression stroke In the vicinity, the shortest flow path that leads from the dead volume near the escape hole 65 of the gasket 63 of the compression chamber 13 and the inner peripheral surface 14 b to the discharge hole 19 through the communication groove 64 and the slit groove 61 provided in the suction valve seat 60. It is formed. Therefore, the working fluid 3 located near the suction side inner peripheral surface 14 b of the compression chamber 13 smoothly flows from the communication groove 64 along the slit groove 61 toward the discharge hole 19, and the suction side inner periphery of the compression chamber 13. Residuals near the surface 14b are suppressed. Further, by forming the discharge channel using the slit groove 61, the increase in dead volume is suppressed, the amount of re-expansion of the residual working fluid 3 in the suction stroke is reduced, and the volume efficiency of the hermetic compressor is improved. be able to. Moreover, since the overcompression resulting from retention of the working fluid 3 near the inner peripheral surface 14b of the compression chamber 13 can be suppressed, the compressor input can be reduced and the efficiency is improved.

  As described above, in the present embodiment, the volume of the residual working fluid is reduced by reducing the discharge flow loss in the compression chamber at the top dead center position of the piston and reducing the residual working fluid. Efficiency can be improved and the efficiency of a hermetic compressor can be improved.

(Embodiment 2)
FIG. 6 is a plan view of a suction reed valve assembly part of a hermetic compressor according to a second embodiment of the present invention. In addition, the same code | symbol is attached | subjected and demonstrated to the component which is the same as that of Embodiment 1, or is equivalent.

As shown in FIG. 6, the hermetic compressor according to the second embodiment of the present invention has a communication groove 164 a that communicates the slit groove 161 of the valve seat 160 and the inner peripheral surface 14 b of the cylinder 14 as in the first embodiment. 164b and 164c, and the communication groove 164a is arranged at a substantially plane symmetrical position with respect to the arrangement of the discharge holes 19. With this configuration, during the compression stroke in which the piston 16 operates from the bottom dead center to the top dead center, it is close to the inner peripheral surface 14b of the compression chamber 13 away from the discharge hole 19 (outer peripheral edge portion of the top surface of the piston 16). The working fluid 3 positioned at the position can be guided to the discharge hole 19 along the communication grooves 164a, 164b, 164c and the slit groove 161 by forming three discharge channels.

  As a result, the overcompression that occurs when the working fluid 3 stays near the inner peripheral surface 14b of the compression chamber 13 can be further suppressed, and the efficiency of the hermetic compressor can be improved.

  Further, since a plurality of communication grooves 164a, 164b, and 164c are provided, discharge is performed from the vicinity of the inner peripheral surface 14b of the compression chamber 13 through the communication grooves 164a, 164b, 164c and the slit groove 161 provided in the suction valve seat 161. A plurality of discharge passages communicating with the holes 16 are formed. The working fluid 3 located near the inner peripheral surface 14b of the compression chamber 13 by these discharge paths has a loss of the discharge flow path that flows from the communication grooves 164a, 164b, and 164c toward the discharge hole 19 through the slit groove 161. It is further suppressed. As a result, it is possible to suppress over-compression that occurs due to retention of the working fluid 3 in the vicinity of the inner peripheral surface 14b of the compression chamber 13, thereby reducing the compressor input.

  As described above, according to the present embodiment, by reducing the discharge flow loss in the compression chamber at the top dead center position of the piston and reducing the re-expansion amount of the residual working fluid by reducing the residual working fluid. The volumetric efficiency can be improved and the efficiency of the hermetic compressor can be improved.

  As described above, since the hermetic compressor according to the present invention can improve the compressor efficiency by improving the volumetric efficiency, it is not limited to an electric refrigerator for home use, but also an air conditioner, a vending machine, other refrigeration apparatuses, It can be widely applied to industrial compressors such as air compressors.

DESCRIPTION OF SYMBOLS 1 Airtight container 6 Electric element 9 Compression element 13 Compression chamber 14 Cylinder 14a Open end 14b Inner peripheral surface 15 Cylinder block 16 Piston 17 Valve plate 18 Suction hole 19 Discharge hole 20 Suction lead valve 60 Suction valve seat 61 Slit groove 63 Gasket 64, 164a, 164b, 164c communication groove

Claims (2)

An electric element and a compression element driven by the electric element are accommodated in a sealed container. The compression element includes a cylinder block having a cylinder, a piston that reciprocates in the cylinder, and an open end of the cylinder block. A gasket that forms a compression chamber by the cylinder and the piston, a suction valve seat, and a valve plate, wherein the valve plate has a suction hole at a substantially plane symmetrical position with respect to the discharge hole and the discharge hole. The suction valve seat includes: a suction reed valve that opens and closes the suction hole; a slit groove that is formed on an outer periphery of the suction lead valve and communicates with the discharge hole; and an inner peripheral surface of the slit groove and the cylinder A hermetic compressor having a communication groove that communicates with each other. The hermetic compressor according to claim 1, further comprising a plurality of communication grooves for suction valve seats.