JP4735084B2 - Hermetic compressor - Google Patents

Description

  The present invention relates to an inverter-controlled hermetic compressor mainly used in an electric refrigerator-freezer for home use.

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

  Conventionally, as this type of hermetic compressor, there is one using a resin suction muffler (see, for example, Patent Document 1).

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

  5 is a longitudinal sectional view of a conventional hermetic compressor described in Patent Document 1, FIG. 6 is a front view of the conventional suction muffler, and FIG. 7 is a sectional view taken along line AA ′ of the conventional suction muffler of FIG. It is.

  5 to 7, the sealed container 1 includes an electric element 5 including a stator 3 having a winding portion 3 a and a rotor 4, a compression element 6 driven by the electric element 5, and a lower part of the closed container 1. The oil 8 stored in is stored.

The crankshaft 10 has a main shaft portion 11 in which the rotor 4 is press-fitted and fixed, and an eccentric portion 12 formed eccentric to the main shaft portion 11, and an oil pump 13 opens into the oil 8 inside the main shaft portion 11. It is provided as follows. The cylinder block 20 has a substantially cylindrical compression chamber 22 and a bearing portion 23 that supports the main shaft portion 11 and is formed above the electric element 5.

  The piston 30 is inserted into the compression chamber 22 so as to be slidable back and forth, and is connected to the eccentric portion 12 by a connecting means 31. The valve plate 32 seals the end face of the compression chamber 22, and a leaf spring-like movable valve 33 is formed in the valve plate and constitutes a suction valve 35 together with a suction hole 34 communicating with the compression chamber 22. The head 36 forms a high pressure chamber and is fixed to the opposite side of the compression chamber 22 of the valve plate 32. The suction pipe 39 is fixed to the sealed container 1 and connected to the low-pressure side (not shown) of the refrigeration cycle, and guides R134a (not shown), which is a refrigerant gas, into the sealed container 1.

  Here, the sealed container 1 is formed by pressing an iron plate, and the air column resonance frequency in the sealed container 1 is about 500 Hz when the refrigerant gas R134a is used.

  The suction muffler 40 forms a silencing space 41 inside. The silencing space 41 is formed of two rooms, a room A 40a and a room B 40b, which are divided into left and right, and a communication space 40c that connects the room A 40a and the room B 40b. The first communication path 42 communicates the movable valve 33 and the silencing space 41, bends and extends into the silencing space 41 at an angle of about 50 degrees, and the first opening 42 a opens into the silencing space 41. ing. The second communication path 43 communicates the inside of the sealed container 1 and the silencing space 41, and the second opening 43 a extends into the silencing space 41 in the silencing space 41. The A room 40a forms a resonance type muffler of about 500 Hz.

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

The rotor 4 of the electric element 5 rotates the crankshaft 10, and the rotational movement of the eccentric portion 12 is transmitted to the piston 30 through the connecting means 31, so that the piston 30 reciprocates in the compression chamber 22, thereby cooling. R134a refrigerant gas flows into the sealed container 1 from a system (not shown) and is guided into the sealed container 1 through the suction pipe 39. The sucked R134a refrigerant gas passes through the second communication passage 43 of the suction muffler 40, opens to the B room 40b, passes through the first communication passage 42, passes through the suction hole 34, and opens in the compression chamber 22 when the movable valve 33 is opened. Compressed and discharged into the cooling system.

Here, when the refrigerant gas R134a is sucked into the compression chamber 22, the movable valve 33 opens and closes. At this time, the movable valve 33 generates pressure pulsations including various frequencies at the time of opening and closing, and the refrigerant flow. Propagate in the opposite direction. Among the pressure pulsations, when 500 Hz which is the air column resonance mode reaches the inside of the closed container 1, this becomes a vibration source, and noise in the 500 Hz band which is the air column resonance mode of the closed container 1 increases in the closed container 1. However, since the A room 40a forms a resonance muffler of about 500 Hz, the 500 Hz band sound of the pressure pulsation is greatly attenuated in the A room 40a.
JP 2003-172265 A

  However, in the above-described conventional configuration, it is necessary to configure a resonance type muffler for a specific frequency in the silencing space 41 itself of the suction muffler 40, and it is difficult to reduce the volume.

  Furthermore, since the opening ends of the first opening portion 42a and the second opening portion 43a are opposed to each other, they are opened to the sound deadening space 41 in the middle and the flow rate of the refrigerant gas is reduced to perform oil separation. The refrigerant gas that is guided by the first communication passage 42 and contains a large amount of the oil 8 is guided to the compression chamber 22.

  For this reason, a conventional suction muffler that is reduced in size while maintaining the internal shape cannot obtain a sufficient sound reduction level and cannot attenuate the pulsating sound, and compresses the refrigerant gas containing a large amount of oil 8. The performance was getting worse.

  The present invention solves the above-described conventional problems, and an object thereof is to realize a hermetic compressor having low noise and stable performance.

In order to solve the above-described conventional problems, the hermetic compressor according to the present invention includes both the opening end in the silencing space of the communication pipe of the suction muffler and the opening end in the silencing space of the tail pipe in the longitudinal center of the silencing space. The anti-resonance part is generated in the silencing characteristic of the suction muffler and is made to coincide with a specific target frequency by opening it close to the position separated in the flow direction of the refrigerant gas flowing out from the opening end in the silencing space of the tail pipe from This has the effect of effectively reducing the pulsating sound.

Further, the muffling space open end of muffling space open end and said tail pipe of the communicating pipe together is opened in the same direction, the muffling space open end of the communicating pipe, from silencing space within the open end of the tail pipe Also, it extends to a position away from the tail pipe in the flow direction of the refrigerant gas, thereby promoting the oil separation of the refrigerant gas in the suction muffler.

  The hermetic compressor of the present invention can effectively attenuate the pulsation sound even if the noise reduction space of the suction muffler is reduced and promote oil separation of the refrigerant gas, so that the noise is low and the performance can be stabilized. .

The invention described in claim 1
A cylinder piston reciprocates, is formed in a horizontally long shape, and a compression element and a suction muffler forming an internal mute space housed in a sealed container, said suction muffler, one end extending in a vertical direction A communication tube that communicates with the cylinder and has the other end extending in the horizontal direction and opened to communicate with the muffling space, one end communicating with the space in the sealed container , and the other end extending in the horizontal direction. A tail pipe that communicates with the silencing space, and the communication pipe and the tail pipe are arranged close to each other in the horizontal direction within the silencing space, and the opening in the silencing space of the communication pipe end, and the both the muffling space open end of the tail tube, open in the same direction, and wherein the flow direction of the refrigerant gas flowing out from the muffler space open end of the longitudinal direction the tail pipe from the center of the silencing space away in Placed in position, further, the muffling space open end of the communicating tube, but also from the muffling space open end of the tail pipe was extended to a position away in the flow direction of the refrigerant gas from the tail pipe, The anti-resonance part can be generated in the muffler characteristics of the suction muffler, and the pulsating noise in question can be reduced locally by reducing the sound source of a specific frequency to an extremely low level. Promote and stabilize performance.

Further, the opening end in the silencing space of the communication pipe extends to a position farther in the flow direction of the refrigerant gas from the tail pipe than the opening end in the silencing space of the tail pipe, thereby including oil mist. When the refrigerant gas is sucked from the opening end of the communication pipe in the silencing space, the refrigerant gas is sucked in while colliding with the wall surface of the opening end of the communication pipe in the silencing space. As a result, oil separation in the refrigerant gas is promoted. The efficiency can be improved and the performance can be stabilized .

The invention according to claim 2 is the invention according to claim 1 , wherein the anti-resonance frequency of the inhalation muffler is matched with the air column resonance frequency in the sealed container. The acoustic radiation component from the inhalation muffler that excites resonance is drastically reduced, and pulsation noise can be effectively reduced .

The invention according to claim 3 is the invention according to claim 1 or 2 , wherein the open end in the sound deadening space of the communication pipe is positioned above the open end in the sound deadening space of the tail pipe. Since oil is separated at the wall below the opening end in the silencing space and falls below the silencing space, this falling oil is not sucked in from the opening end in the silencing space of the communication pipe, and a higher purity refrigerant gas is cylindered. It can be guided inward, and the efficiency can be dramatically improved and the performance can be stabilized.

The invention according to claim 4 is the invention according to any one of claims 1 to 3 , wherein one surface of the wall constituting the tail tube is shared with the wall forming the silencing space , and the tail is formed. the extension of the wall constituting the tube, which was tilted in the direction in which the sound absorbing space widens, the refrigerant gas including oil mist oil is separated by walls constituting the tailpipe when flowing tail pipe, the refrigerant The oil separated when the gas flows out from the opening end in the silencing space of the tail pipe into the silencing space travels along the extension and moves away from the opening end in the silencing space of the communication pipe into which the refrigerant gas is sucked. Then, since it falls below the silencing space, oil separation in the refrigerant gas is promoted, efficiency can be improved, and performance can be stabilized.

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

(Embodiment 1)
1 is a longitudinal sectional view of a hermetic compressor according to Embodiment 1 of the present invention, FIG. 2 is a longitudinal sectional view of a suction muffler, and FIG. 3 is a sectional view taken along line AA ′ of the suction muffler of FIG. 4 and 4 are acoustic characteristic diagrams of the inhalation muffler.

1 to 4, the present embodiment has an overall height that is lower by about Δ20 mm than the conventional one, for example, stores oil 102 in the bottom of the sealed container 101, an electric element 110, and a compression element 120 driven by the electric element 110. And is filled with a hydrocarbon-based refrigerant having a low warming coefficient such as R600a. A power supply terminal 108 for supplying power to the electric element 110 is attached to the sealed container 101.

  First, the electric element 110 will be described.

  The electric element 110 forms a salient pole concentrated winding DC brushless motor, and includes a stator 112 and a rotor 114, and is connected to an inverter drive circuit (not shown) and a conductor via a power supply terminal 108. It is connected.

  The stator 112 is formed by winding a winding directly on a magnetic pole tooth of a stator core formed of an electromagnetic steel plate with little iron loss via an insulating material. The rotor 114 is disposed on the inner diameter side of the stator 112, and includes a rotor core and a permanent magnet disposed in the rotor core, and is fixed to the main shaft 122 of the crankshaft 121.

  The electric element 110 is operated at a plurality of frequencies between 18 r / s and 81 r / s by inverter driving.

  Next, details of the compression element 120 will be described below.

  The compression element 120 is disposed above the electric element 110.

  The crankshaft 121 constituting the compression element 120 includes a main shaft 122 and an eccentric shaft 124, and an oil supply mechanism 125 that communicates from the lower end of the main shaft 122 immersed in the oil 102 to the upper end of the eccentric shaft 124. The block 126 includes a bearing portion 127 and a cylinder 130 that rotatably support the main shaft 122.

  The piston 128 is reciprocally inserted into the cylinder 130 and forms a compression chamber 134 together with a valve plate 132 disposed on the end face of the cylinder 130. The piston 128 is connected to the eccentric shaft 124 by connecting means 136.

  The suction muffler 140 is fixed by being sandwiched between the valve plate 132 and the cylinder head 138, and is mainly formed of a synthetic resin such as polybutylene terephthalate which is a crystalline resin to which glass fibers are added.

Further, the suction muffler 140 is formed in a horizontally long shape as shown in FIG. 2, forms a sound deadening space 142 inside, and includes a communication pipe 150 and a tail pipe 152 , and one end of the communication pipe 150 is horizontally oriented. A tail end 152 is provided that has an opening end 154 in the silencing space that extends and opens in the silencing space 142 , and a compression chamber opening end 156 that extends in the vertical direction and communicates with the compression chamber 134 of the cylinder 130. Is provided with an opening end 158 in the silencing space whose one end extends in the horizontal direction and opens into the silencing space 142, and an opening end 160 in the sealed container whose other end opens into the sealed container space 141.

Further, the refrigerant gas that flows out from the center in the longitudinal direction of the silencing space 142 from the opening end 158 of the silencing space 142 and the opening end 158 of the silencing space 142 from the longitudinal center of the silencing space 142. In the flow direction, the openings are arranged in the same direction.

  The main component of the pulsating sound is the air column resonance sound of the sealed container inner space 141, and the air column resonance frequency 162 of the sealed container inner space 141 and the antiresonance frequency 171 of the acoustic characteristic 170 of the suction muffler 140 are matched. .

Further, the opening end 154 in the silencing space is extended to a position away from the opening end 158 in the silencing space in the refrigerant gas flow direction .

Further, the muffling space open end 154 extending in the horizontal direction of the communicating pipe 150, and is positioned above the muffler space open end 158 of the tail pipe 152.

  Further, one surface of the wall 212 constituting the tail pipe 152 is shared with the wall 212 of the sound deadening space 142, and the extension part 214 of the wall 212 constituting the tail pipe 152 is inclined in a direction in which the sound deadening space 142 is expanded.

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

  When the electric element 110 is energized from the inverter drive circuit, the rotor 114 rotates together with the crankshaft 121 by the magnetic field generated in the stator 112. As the main shaft 122 rotates, the eccentric shaft 124 rotates eccentrically, and this eccentric motion is converted into a reciprocating motion through the connecting means 136, and the piston 128 is reciprocated in the cylinder 130 to refrigerate the refrigerant gas in the sealed container 101. Is compressed into the compression chamber 134 and compressed.

  Further, in the suction stroke accompanying the compression operation, the refrigerant gas in the sealed container 101 is intermittently sucked into the compression chamber 134 via the suction muffler 140, and after being compressed, the sealed container via the discharge pipe or the like. 101 is sent to a known refrigeration cycle (not shown). The suction muffler 140 is a communication pipe 150, a tail pipe 152, and a sound deadening space 142, and reduces pulsation noise generated by intermittent refrigerant gas suction. Further, the suction muffler 140 is made of polybutylene terephthalate resin that has significantly less heat transfer than metal or the like, and prevents the low-temperature refrigerant returned from the refrigeration cycle from being heated, thereby preventing the performance from deteriorating.

  Here, the silencing effect of the suction muffler 140 will be described in detail.

FIG. 4 shows the acoustic characteristics of the silencing space 142 of the suction muffler 140, where the horizontal axis is frequency, and the vertical axis is the sound pressure level radiated from the open end 160 in the sealed container of the tail tube 152 of the suction muffler 140. Yes, it indicates that the sound volume level increases as the sound pressure level decreases. Also shows the acoustic characteristics 170 of the present embodiment indicated by the solid line, the acoustic characteristics 173 when silencing space within the open end 158 of the tail pipe 152 is set to the longitudinal center line of the suction muffler 140 by the dashed line .

  The opening end 158 in the silencing space of the tail pipe 152 moves away from the opening end 154 in the silencing space of the communication pipe 150, and the anti-resonance frequency 171 moves to the high frequency side like the anti-resonance frequency 174 as it approaches the center line. In addition, when the anti-resonance frequency 171 is close to the resonance frequency 172, the sound reduction is remarkably reduced like the anti-resonance frequency 174.

  From this, the noise reduction volume of the anti-resonance frequency 171 is increased as the opening end 158 of the tail pipe 152 in the noise reduction space is opened at a position away from the center line and the opening end 154 in the noise reduction space of the communication pipe 150 is closer. The pulsating sound can be made extremely low by matching the specific target frequency of the pulsating sound that is a problem of the hermetic compressor with the anti-resonance frequency 171.

Here, the peak level of the resonance frequency 172 of the acoustic characteristic 170 is larger than the peak level of the resonance frequency 175 of the acoustic characteristic 173, but is deviated from a specific target frequency of the pulsating sound that is a problem of the hermetic compressor. The noise is not radiated from the compressor without being amplified.

  For this reason, even if the capacity of the silencing space 142 is reduced by downsizing the compressor and the basic silencing capability as a muffler is reduced, the silencing effect at a specific target frequency can be dramatically improved.

  In addition, by making this specific target frequency coincide with the air column resonance frequency 162 of the sealed container inner space 141, the compressor in the present embodiment can realize extremely low noise characteristics.

  Further, along with the compression operation, the oil 102 stored in the lower part of the sealed container 101 is guided from the lower end of the main shaft 122 to the upper end of the eccentric shaft 124 by the oil supply mechanism 125 of the crankshaft 121, and each sliding part and the sealed container 101 are guided. Although it is sprayed inside and a part becomes oil mist and mixes with refrigerant gas, most is led to the lower part in the airtight container 101, and is stored.

  The refrigerant gas 200 containing the oil mist is guided from the sealed container space 141 into the sound deadening space 142 through the tail tube 152 and sucked from the opening end 154 of the communication pipe 150 in the sound deadening space. At this time, since the opening end 154 in the silencing space of the communication pipe 150 and the opening end 158 in the silencing space of the tail pipe 152 are open in the same direction, the ejection pipe 150 is ejected into the silencing space 142 from the opening end 158 in the silencing space. Most of the refrigerant gas 200 is sucked in while colliding with one end, the wall surface forming the opening end 154 in the silencing space.

  For this reason, the oil mist contained in the refrigerant gas 200 adheres to the wall surface of the opening end 154 in the silencing space, and the oil 102 is separated from the refrigerant gas 200. The separated oil 102 falls to the lower part in the muffler space 142, is discharged from the oil discharge hole 178 to the sealed container space 141, and is stored in the lower part in the sealed container 101.

  From this, the refrigerant gas with higher purity can be led into the cylinder 130 from the opening end 154 in the silence space of the communication pipe 150, and the performance can be stabilized.

Further, the noise reduction space in which the oil mist collides is obtained by extending the opening end 154 in the noise reduction space of the communication pipe 150 from the opening end 158 in the noise reduction space of the tail pipe 152 in the flow direction of the refrigerant gas flowing out from the tail pipe 152. The area of the wall surface constituting the inner opening end 154 is increased, the oil separation action of the refrigerant gas 200 is promoted, and a more efficient and stable performance can be obtained.

  Further, by positioning the opening end 154 in the silencing space of the communication pipe 150 above the opening end 158 in the silencing space of the tail pipe 152, oil is separated on the wall surface below the opening end 154 in the silencing space of the communication pipe 150, The separated oil 102 falls below the silencing space 142. Therefore, the falling oil 102 is not sucked from the open end 154 in the silencer space of the communication pipe 150, and the refrigerant gas with higher purity can be guided into the cylinder 130, and the efficiency is dramatically improved. Stable performance can be obtained.

  Further, one surface of the wall 212 constituting the tail pipe 152 is shared with the wall 212 of the sound deadening space 142, and the extension part 214 of the wall 212 constituting the tail pipe 152 is inclined in the direction in which the sound deadening space 142 spreads, so that the oil Since the refrigerant gas 200 containing mist flows while colliding with the wall 212 constituting the tail tube 152 when flowing in the tail tube 152, the oil 102 is separated in the tail tube 152, and the refrigerant gas 200 is separated from the tail tube 152. It flows out into the silencing space 142 from the opening end 158 of the silencing space 152.

  At this time, the oil 102 travels along the extension 214 in the opposite direction so as to be away from the flow of the refrigerant gas 200, and then falls below the muffler space 142. For this reason, the refrigerant gas 200 sucked from the open end 154 in the silencing space of the communication pipe 150 has a very high refrigerant purity, and can dramatically improve the efficiency of the hermetic compressor and stabilize the performance. .

  The electric element 110 of the present embodiment is a salient pole concentrated winding type DC brushless motor. However, even in a distributed winding type induction motor, the suction muffler 140 having a small internal volume with a reduced size in the height direction according to the present invention. By using this, noise can be reduced, performance can be stabilized, and the hermetic compressor can be downsized.

  In particular, in the electric element 110 using a rare earth magnet capable of obtaining a strong magnetic force, the dimension in the height direction can be further reduced, so that the effect of the present invention that can reduce noise even when the height is low is remarkable. Thus, the height of the hermetic compressor can be further reduced.

  Further, in the hermetic compressor according to the present invention, the rotation speed is operated in a wide range by the inverter, and the scattering state of the oil 102 varies greatly depending on the rotation speed. Even in high-speed operation in which the oil 102 is easily sucked, the flow rate of the refrigerant gas that collides with the wall 212 of the tail tube 152 increases and the oil separation action is promoted, so that the oil 102 can be sucked into the compression chamber 134 in a wide operating range. This can prevent and improve the efficiency of the hermetic compressor and stabilize the performance.

  As described above, the hermetic compressor of the present invention can optimize the acoustic characteristics of the suction muffler 140 and can reliably separate the oil 102 in the refrigerant gas. it can.

  As described above, since the hermetic compressor according to the present invention can reduce noise and stabilize the performance of the compressor, it is not limited to an electric refrigerator-freezer for home use, but also an air conditioner, a vending machine, and other refrigeration units. Widely applicable to devices etc.

1 is a longitudinal sectional view of a hermetic compressor according to Embodiment 1 of the present invention. Cross-sectional view of the suction muffler in the same embodiment FIG. 2 is a cross-sectional view of the suction muffler of FIG. Acoustic characteristics diagram of inhalation muffler in the same embodiment Vertical section of a conventional hermetic compressor Front view of conventional suction muffler A-A 'line sectional view of the conventional suction muffler of FIG.

DESCRIPTION OF SYMBOLS 101 Sealed container 102 Oil 120 Compression element 128 Piston 130 Cylinder 140 Suction muffler 141 Sealed container inner space 142 Silent space 150 Communication pipe 152 Tail pipe 154,158 Opening end in the silenced space 162 Air column resonance frequency 171 174 Anti-resonance frequency 212 Wall 214 Extension

Claims (4)

A cylinder piston reciprocates, is formed in a horizontally long shape, and a compression element and a suction muffler forming an internal mute space housed in a sealed container, said suction muffler, one end extending in a vertical direction A communication tube that communicates with the cylinder and has the other end extending in the horizontal direction and opened to communicate with the muffling space, one end communicating with the space in the sealed container , and the other end extending in the horizontal direction. A tail pipe that communicates with the silencing space, and the communication pipe and the tail pipe are arranged close to each other in the horizontal direction within the silencing space, and the opening in the silencing space of the communication pipe end, and the both the muffling space open end of the tail tube, open in the same direction, and wherein the flow direction of the refrigerant gas flowing out from the muffler space open end of the longitudinal direction the tail pipe from the center of the silencing space away in Placed in position, further, the muffling space open end of the communicating pipe, hermetic compressor which is extended to a position away in the flow direction of the refrigerant gas from the tail pipe than silencing space within the open end of the tail pipe Machine. Wherein the anti-resonant frequency of the suction muffler, hermetic compressor according to claim 1, the air column resonance frequency is matched in the closed vessel. 3. The hermetic compressor according to claim 1 , wherein an opening end in the silencing space of the communication pipe is positioned above an opening end in the silencing space of the tail pipe . The surface of the wall constituting the tail pipe is shared with the wall forming the silencing space, and the extension portion of the wall constituting the tail pipe is inclined in the direction in which the silencing space expands. The hermetic compressor according to claim 3.