JP5934880B2 - Hermetic compressor - Google Patents

Description

  The present invention relates to a hermetic compressor used in a cooling system used in a home electric refrigerator-freezer, a showcase, and the like.

  In recent years, the demand for protecting the global environment has been increasing, and there is a strong demand for particularly high efficiency in refrigerators and other refrigeration cycle apparatuses.

  Conventionally, as this type of hermetic compressor, there is a compressor provided with a discharge muffler independent of a cylinder block (for example, see Patent Document 1).

  In addition, in order to obtain a high silencing effect on the suction muffler, there is one in which an opening end in the suction muffler of the refrigerant gas passage extends to a noise node in a specific frequency region (see, for example, Patent Document 2).

  Hereinafter, the conventional hermetic compressor will be described with reference to the drawings.

  FIG. 5 is a transverse sectional view of a compressor showing a conventional example, and FIG. 6 is a longitudinal sectional view of the compressor.

  5 and 6, the electric compression element 3 is accommodated in the sealed container 1. The electric compression element 3 includes a stator 5 disposed below, a cylinder block 9 that forms a compression chamber 7, a crankshaft 11 that is rotatably supported by the cylinder block 9, and a reciprocating slide in the compression chamber 7. A piston 13 that is freely inserted, a valve plate 17 that is disposed so as to seal the end of the compression chamber 7 and is fixed so as to be sandwiched by the cylinder head 15, and a discharge path 19 are provided.

  The discharge path 19 includes an inlet pipe 23 that communicates the discharge muffler 21 independent of the cylinder block 9 and the cylinder block 9, and an outlet pipe 25 that communicates the discharge muffler 21 and the high-pressure side of the cooling system (not shown). ing.

  The operation of the conventional hermetic compressor configured as described above will be described below.

  When the stator 5 is energized from an external power source, a magnetic field is generated and the crankshaft 11 rotates. Accordingly, the piston 13 reciprocates in the compression chamber 7, and the electric compression element 3 performs a predetermined compression operation.

  Thereby, the refrigerant flowing from the low pressure side of the cooling system (not shown) is sucked into the compression chamber 7 through the valve plate 17. Then, the refrigerant guided to the compression chamber 7 is compressed in the compression chamber 7 by the reciprocating motion of the piston 13, and then guided to the discharge muffler 21 through the inlet pipe 23, and the cooling system (see FIG. (Not shown) is discharged to the high pressure side.

  Here, the compressed refrigerant reaches a high temperature and flows to the discharge muffler 21. However, since the discharge muffler 21 is independent of the cylinder block 9, the compression chamber 7 minimizes heat reception from the high-temperature refrigerant gas. And volume efficiency can be improved.

International Publication No. 86/002703 JP 2003-42064 A

  However, in the conventional configuration in Patent Document 1, discharge pulsation is generated by repeatedly compressing the refrigerant gas in the compression chamber 7, and sound is propagated to a specific frequency in the discharge muffler 21. The dense wave is reflected to form a standing wave. However, the standing wave is not considered, and the discharge muffler 21 resonates, which may increase noise.

  SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and an object of the present invention is to provide a low noise hermetic compressor that avoids an increase in noise due to resonance of a discharge muffler.

  In order to solve the above problems, a hermetic compressor according to the present invention has a discharge muffler having a symmetrical shape with respect to the flow direction of the refrigerant gas, and the inlet end of the discharge muffler of the inlet pipe is connected to the flow of the refrigerant gas of the discharge muffler. It is arranged at a position approximately in the middle of the direction.

  In this way, by making the discharge muffler symmetrical with respect to the flow direction of the refrigerant gas, the opening end in the discharge muffler of the inlet pipe with the largest pressure pulsation can be easily separated from the standing wave of a specific frequency. Can be placed on the part. As a result, an increase in noise due to the resonance of the discharge muffler can be easily avoided.

  In the hermetic compressor of the present invention, the discharge muffler has a symmetrical shape with respect to the flow direction of the refrigerant gas, and the opening end in the discharge muffler of the inlet pipe is arranged substantially in the middle of the flow direction of the refrigerant gas in the discharge muffler. As a result, an increase in noise due to resonance of the discharge muffler can be easily avoided, and a low noise hermetic compressor can be provided.

1 is a cross-sectional view of a hermetic compressor according to Embodiment 1 of the present invention. Vertical sectional view of the hermetic compressor in the first embodiment The principal part disassembled perspective view of the hermetic compressor in the first embodiment Sectional drawing of discharge path of hermetic compressor in Embodiment 2 of the present invention Cross-sectional view of a conventional hermetic compressor Vertical section of a conventional hermetic compressor

The invention of claim 1 is provided with a discharge passage for deriving the refrigerant gas compressed in the compression chamber in the closed container, the discharge passage, and a discharge muffler, one end opened to the discharge in the muffler, the other end Has an inlet pipe communicating with the compression chamber, one end opened in the discharge muffler, and the other end connected to a discharge pipe fixed to the sealed container, and the discharge muffler The inlet pipe and the outlet pipe are formed so as to be symmetrical with respect to the flow direction of the refrigerant gas, and the opening ends of the outlet muffler of the inlet pipe and the outlet pipe are arranged at positions that are not coaxial with each other. The opening end in the discharge muffler is arranged approximately in the middle of the flow direction of the refrigerant gas in the internal space of the discharge muffler.

  In such a configuration, by making the discharge muffler symmetrical with respect to the flow direction of the refrigerant gas, the standing wave in the discharge muffler can be easily formed symmetrically with respect to the flow direction of the refrigerant gas. In addition, a sparse part having a specific resonance frequency such as a standing wave secondary mode that easily affects noise can be generated in the middle of the flow direction of the refrigerant gas in the discharge muffler. As a result, the opening end in the discharge muffler of the inlet pipe that supplies the discharge pulsation can be disposed in the sparse part of the standing wave of the specific frequency, and an increase in noise due to the resonance of the discharge muffler can be avoided. Therefore, a low noise hermetic compressor can be provided.

  According to a second aspect of the present invention, in the first aspect of the present invention, the inner space of the discharge muffler is formed to be substantially cylindrical.

  As a result, the discharge muffler inner space can be simplified, and as a result, it is possible to suppress the occurrence of many resonance frequencies by complicating the distribution of standing waves in the discharge muffler. In addition, the discharge muffler itself may vibrate due to the discharge pulsation, increasing the noise, but by making the discharge muffler itself substantially cylindrical, the rigidity of the discharge muffler itself can be increased and difficult to vibrate. it can. Therefore, it is possible to provide a hermetic compressor with lower noise.

  Embodiments of a compressor according to the present invention will be described below with reference to the drawings. The present invention is not limited to the embodiments.

(Embodiment 1)
1 is a cross-sectional view of a hermetic compressor according to Embodiment 1 of the present invention, FIG. 2 is a vertical cross-sectional view of the hermetic compressor according to Embodiment 1, and FIG. It is a principal part disassembled perspective view of a hermetic compressor.

  In FIGS. 1 to 3, the hermetic container 101 houses an electric element 105 and a compression element 103 driven by the electric element 105 via a crankshaft 111 described later.

  The compression element 103 is inserted into the compression chamber 107 so as to be reciprocally slidable by the cylinder block 109 forming the compression chamber 107, the crankshaft 111 rotatably supported by the cylinder block 109, and the rotation of the crankshaft 111. A piston 113 that reciprocates by movement, a valve plate 117 that is disposed so as to seal the end of the compression chamber 107 and that is fixed so as to be held between the cylinder head 115, and a compressed refrigerant flows. A discharge path 119 is provided.

  The discharge path 119 communicates with a discharge muffler 121 independent from the cylinder block 109, an inlet pipe 123 that connects the inside of the discharge muffler 121 and the compression chamber 107, and a high-pressure side of a cooling system (not shown), and is sealed. An outlet pipe 125 communicating the discharge pipe 102 fixed to the container 101 and the discharge muffler 121 is provided.

  The main body of the discharge muffler 121 is composed of two parts 121a and 121b, and is formed in a substantially cylindrical shape that is symmetrical about the central portion with respect to the flow direction of the refrigerant gas. The opening end in the discharge muffler 121 of the inlet pipe 123 opens in the inner space of the discharge muffler 121 in the middle of the refrigerant gas flow direction (opening end surface position of the one component 121a). Although it is on the same axis, a certain distance is secured.

  The operation and action of the hermetic compressor configured as described above will be described below.

  When the electric element 105 is energized from an external power source, a magnetic field is generated and the electric element 105 rotates. Along with this, the crankshaft 111 rotates, and the piston 113 reciprocates in the compression chamber 107 as the crankshaft 111 rotates, and the compression element 103 performs a predetermined compression operation.

  By this operation, the refrigerant flowing from the low pressure side of the cooling system is sucked into the compression chamber 107 through the valve plate 117. Then, the refrigerant guided to the compression chamber 107 is compressed in the compression chamber 107 by the reciprocating motion of the piston 113, and then guided to the discharge muffler 121 through the inlet pipe 123, and the cooling system from the outlet pipe 125. Is discharged to the high pressure side.

  Here, the compressed refrigerant becomes a high temperature and flows to the discharge muffler 121. However, since the discharge muffler 121 is independent from the cylinder block 109, the compression chamber 107 minimizes heat reception from the high-temperature refrigerant gas. Can be suppressed. As a result, the suction mass (refrigerant circulation amount) of the refrigerant per unit time is increased, so that the volumetric efficiency is improved and the efficiency of the hermetic compressor can be improved.

  Further, the discharge pulsation is generated by the refrigerant gas being repeatedly compressed in the compression chamber 107. By releasing the compressed gas from the inlet pipe 123 to the discharge muffler 121, the discharge pulsation can be attenuated. However, a dense wave that propagates sound is reflected in the discharge muffler 121 to form a standing wave. Yes.

  The dense part of the standing wave (hereinafter referred to as an antinode) has a high sound pressure, and the sparse part (hereinafter referred to as a node) has a low sound pressure. In this standing wave distribution, if the antinode portion of the standing wave is vibrated, the sound increases and the noise attenuation effect cannot be obtained.

  In particular, the size of a hermetic compressor used for a refrigerator is generally about 200 mm in diameter of the hermetic container 101. The size of the discharge muffler 121 independent of the cylinder block 109 cannot be specified because the sound speed in the discharge muffler 121 changes depending on the type of refrigerant gas used, the usage environment, etc. Frequencies that are likely to be amplified are often in the range of 1 to 5 kHz.

  This frequency of 1 to 5 kHz may exist as an eigenvalue of the sealed container 101 or the electric compression element composed of the electric element 105 and the compression element 103. The eigenvalue is discharged by the discharge muffler 121. If the vibration is caused by the pulsation, the noise of the compressor is remarkably increased.

  In the first embodiment, the discharge muffler 121 has a constant shape generated in the discharge muffler 121 by making its outer shape and inner space shape symmetrical with respect to the flow direction of the refrigerant gas. The standing wave can also be made substantially symmetrical with respect to the flow direction of the refrigerant gas. Therefore, the node of the resonance frequency of the standing wave secondary mode that easily affects noise is generated approximately in the middle of the flow direction of the refrigerant gas in the discharge muffler 121. Therefore, the opening end in the discharge muffler 121 of the inlet pipe 123 is disposed at a standing wave node, and as a result, an increase in noise of the hermetic compressor can be easily suppressed.

  Here, in Patent Document 2, it is disclosed that a passage communicating with the outside of the suction muffler is opened at a node of a standing wave formed in the suction muffler to suppress an increase in noise. If it is formed in a complicated shape, it cannot be easily determined in which part of the muffler the node is formed.

  However, in the first embodiment, since the discharge muffler 121 has a symmetrical shape with respect to the flow direction of the refrigerant gas, the node of the resonance frequency of the standing wave secondary mode that easily affects noise is the discharge muffler 121. It can be easily determined that it is in between.

  Further, the discharge muffler 121 of the first embodiment is formed in a substantially cylindrical shape. When the discharge muffler 121 has a complicated configuration, standing waves with various frequencies exist and it is difficult to avoid resonance in the discharge muffler 121. However, by making the discharge muffler 121 substantially cylindrical, It can be simplified and resonance can be easily avoided. In addition, the complicated configuration (internal shape) may cause the discharge muffler 121 itself to vibrate due to the discharge pulsation and increase the noise. The substantially cylindrical shape increases the rigidity of the discharge muffler 121 itself and makes it difficult to vibrate. As a result, an increase in noise of the hermetic compressor can be suppressed.

(Embodiment 2)
FIG. 4 is a sectional view of the discharge path in the second embodiment of the present invention. Since the hermetic compressor main body is not much different from that of the first embodiment, here, the above-described FIG. 1 and FIG.

The discharge pulsation generated when the refrigerant gas is repeatedly compressed in the compression chamber 107 is not sufficiently attenuated by the hermetic compressor, and is supplied to the high pressure side of the cooling system (not shown) via the outlet pipe 125. Propagate. Propagated discharge pulsation may vibrate the piping of the cooling system (not shown), and although noise is not radiated from the hermetic compressor itself, the noise as the cooling system (not shown) is increased. sometimes it intends want, it is very important to sufficiently attenuate the discharge pulsation.

  In the second embodiment, the opening ends in the discharge muffler 121 of the inlet pipe 123 and the outlet pipe 125 are arranged at positions that are not coaxial, and both are substantially in the middle of the flow direction of the refrigerant gas in the discharge muffler 121 (one By disposing at the position of the opening end surface of the component 121a, it is possible to suppress an increase in noise not only in the hermetic compressor but also in the cooling system (not shown) itself.

  The configuration in which the inner space shape and the outer shape of the discharge muffler 121 are symmetrical with respect to the refrigerant gas flow direction is the same as that in the first embodiment.

  As described above, since the hermetic compressor according to the present invention can be provided with low cost, high efficiency, low noise, and reliability, the hermetic compressor used in an air conditioner, a refrigerator-freezer, and the like can be used. Is also applicable.

DESCRIPTION OF SYMBOLS 101 Airtight container 103 Compression element 105 Electric element 107 Compression chamber 109 Cylinder block 111 Crankshaft 113 Piston 115 Cylinder head 117 Valve plate 119 Discharge path 121 Discharge muffler 123 Inlet pipe 125 Outlet pipe

Claims (2)

A discharge path for leading the refrigerant gas compressed in the compression chamber in the sealed container is provided,
The discharge path has a discharge muffler, one end opened in the discharge muffler, the other end communicated with the compression chamber, one end opened in the discharge muffler, and the other end fixed to the sealed container A configuration having an outlet pipe connected to the discharge pipe,
Further, the discharge muffler is formed so as to be symmetric with respect to the flow direction of the refrigerant gas with the central portion as an axis, and the opening ends of the inlet pipe and the outlet pipe in the discharge muffler are not coaxial. arrangement, and the open end of the discharge in the muffler at the inlet tube, the hermetic compressor which is disposed substantially in the middle of the flow direction of the refrigerant gas in the internal space of the discharge muffler.   The hermetic compressor according to claim 1, wherein an inner space of the discharge muffler is formed to have a substantially cylindrical shape.