JP3566837B2 - Scroll compressor - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a scroll compressor mainly used for refrigeration and air conditioning for business use and home use.
[0002]
[Prior art]
Electric compressors for refrigeration and air conditioning include those having a reciprocating compressor, a rotary compressor, and a scroll compressor. Currently, it is growing by making use of its features in terms of cost and performance. Among them, scroll compressors have been put to practical use taking advantage of the features of high efficiency, low noise, and low vibration.
[0003]
Japanese Patent Laying-Open No. 05-240176 discloses a technique in which a scroll compressor performs gas injection into two adjacent compression chambers through one injection port to equalize the amount of injection into each compression chamber. . As a result, it is possible to prevent thermal deformation of the scroll member and deterioration in lubricity of oil caused by local heat bias.
[0004]
[Problems to be solved by the invention]
By the way, the diversification of the operation mode is that the scroll compressor is also operated at a variable speed by inverter control or the like to obtain an optimal operation state at each time, and the gas injection is also cut off depending on the operation mode, It is becoming necessary to release the block.
[0005]
However, when performing such a variable speed operation and shutting off or releasing the gas injection, the compression ratio remains constant regardless of the difference in the operating speed or the shutoff or release of the gas injection in the above-described conventional one. Therefore, there is a limit to the efficiency improvement at low speed operation, and in the gas injection cutoff state, the refrigerant gas in the dead volume including the check valve formed around the gas injection port is compressed in the compression chamber in the compression stroke. Later, the refrigerant expands again when it passes through the compression chamber where the next refrigerant starts to be confined, and this also has a large effect at low load when low-speed operation is performed, and the performance is reduced.
[0006]
An object of the present invention is to obtain a high gas injection performance and a large capacity control width during a heating operation or the like where a high load operation is performed at a low injection pressure, while ensuring performance during a low load operation in a gas injection cutoff state. It is an object to provide a scroll compressor.
[0007]
[Means for Solving the Problems]
In a scroll compressor that performs gas injection through an injection port into a compression chamber formed between a fixed scroll and a orbiting scroll that moves in a circular orbit,
In order to achieve the above-described object, the present invention provides a method for controlling a pair of compression chambers in a predetermined low-speed operation of a blade forming a pair of compression chambers between a fixed scroll and a variable-speed orbiting scroll. until winding end from the spiral length position which satisfies the compression ratio of the offset surfaces Ru increase the compression ratio in accordance with the high-speed operation degree for each of the compression chambers to open the inlet side with a predetermined gap above the predetermined low speed operation And, while having a common feature that a control means for shutting off the gas injection in a timely manner and releasing the shutoff is provided,
One feature is that an injection port is provided at a position sequentially communicating with the unsealed area of the pair of compression chambers.
[0008]
With such a configuration, the gas injection can be performed in a timely manner by shutting off and releasing the gas injection, and at the time of low load operation that is a predetermined low-speed operation, both the pair of compression chambers formed by the fixed scroll and the orbiting scroll have offset surfaces. The area that is not sealed by the gap to be formed easily escapes the refrigerant to be drawn in to the outside through the gap even if the gap is small, and does not exhibit the closing function in the range where the offset surface is provided. There is no supercharging of the refrigerant with a volume commensurate with the above, and only the area where the offset surfaces of both the pair of compression chambers are not formed works effectively, and the operation is highly efficient due to the small confined volume as designed at the predetermined low speed operation. At the same time, gas injection is not performed on the part that works effectively in this low-speed operation, and the gas injection port is not used. By preparative is not open, there is no re-expansion due to the compression of the refrigerant in the dead volume portion including a check valve or the like around the injection port here, to improve the performance of the compressor at low load operation. On the other hand, at the time of high-load operation where high-speed operation is performed, the gap between the pair of compression chambers that keeps them closed is small, and the high-speed turning of the orbiting scroll causes the high- speed operation to the predetermined low-speed operation. Since the confinement of the sucked refrigerant is improved and the amount of sucked refrigerant is increased to increase the compression ratio, the compression stroke is supercharged in accordance with the degree of high-speed operation with respect to low-speed operation. High-pressure operation, such as heating, can be achieved by ensuring a high injection flow rate by performing low-pressure gas injection using the entire compression chamber with a large volume including Time performance also improves. Therefore, the efficiency of the compressor is improved from low-load operation to high-load operation, and annual power consumption can be reduced. In addition, gas injection that utilizes a large effective volume ratio between small-capacity operation at low speed and large-capacity operation at high speed, and a wide swivel angle range while the pair of compression chambers are open. Can be performed, the range of capacity control is expanded, and the responsiveness to diversification of driving is improved. Further, since gas injection is performed to both of the pair of compression chambers, generation of vibration and noise due to imbalance of supercharging can be suppressed, and driving comfort is improved.
[0009]
In this case, if the injection port is provided at a position where the injection port starts to communicate with the unsealed region of the pair of compression chambers from near the start time of the closing function exhibited according to the high-speed operation degree , the injection port is not sealed when the injection port starts to communicate. Since the volume of the region is maximized, the influence of the refrigerant re-expanded in the dead volume can be minimized, and it is effective to perform only one of them.
[0010]
Further, if the injection port is provided at a position where the time during which the injection port communicates with both of the unsealed areas of the pair of compression chambers is substantially equal, the injection flow rates to the pair of compression chambers are substantially equal, and The imbalance of the supercharging in the compression chamber is eliminated, and the driving comfort is further improved.
[0011]
According to the present invention, the swirl angle range of the pair of compression chambers sequentially communicating with the unsealed area, and the swing angle range while the pair of compression chambers are open to one unsealed area, is opened to the other unsealed area. It is also characterized in that an injection port is provided at a position smaller than the turning angle range during the operation.
[0012]
In such a configuration, the injection surface using both the pair of compression chambers is used to improve the capacity at the time of high-speed operation, expand the capacity control width, and balance the supercharging while maintaining the offset surface of one compression chamber. By increasing the forming range and reducing the minimum capacity so as to be suitable for low-speed operation, the capacity control range is expanded, and the opening area and opening time of the injection port to this one compression chamber are shortened. As a result, the injection flow rate is reduced, and it is possible to prevent the injection gas from easily flowing backward due to the expansion of the offset surface, thereby preventing the injection performance from being reduced due to the backflow of the refrigerant. In this case, the maximum swing angle range while the injection port is open to the unsealed area of one compression chamber is 65% or less of the maximum swing angle range while the injection port is open to the unsealed area of the other compression chamber. If provided at a certain position, the effect of the backflow of the refrigerant during gas injection can be sufficiently suppressed.
[0013]
The present invention also provides an injection port at a position where a swing angle range when the one compression chamber is open to an unsealed area is larger than a swing angle range when the one compression chamber is open to the other compression chamber. Is also characterized.
[0014]
In such a configuration, the gas injection at a low pressure over one of the pair of compression chambers at a low pressure over a long time makes it possible to sufficiently secure the overall injection amount while suppressing the problem of the backflow of the refrigerant due to not being sealed. It is possible to further improve the performance under high load operation such as during heating.
[0015]
In each of the above cases, the present invention provides a muffler that covers the outer surface having the discharge port of the compression mechanism in a sealed container containing the compression mechanism and its drive mechanism, and a hole through which an injection pipe connected to the injection port has play. When the muffler is provided, the muffler temporarily receives the refrigerant discharged from the compression mechanism in a large space formed between the compression mechanism and the muffler, diffuses and fills the space, and muffles the sound. Or in cooperation with other existing holes, the refrigerant in the muffler once diffused and muffled flows through the muffler and the next closed space formed by the closed container in a state where it is appropriately restricted, and diffuses again. Since the silencing hole is used to muffle while filling, the silencing effect can be enhanced by using the installation structure of the injection pipe.
[0016]
Further objects and features of the present invention will be apparent from the following description and drawings, and each feature exerts various effects alone or in combination as necessary.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, some embodiments of the present invention will be described with reference to FIGS.
[0018]
(Embodiment 1)
The first embodiment is an example of a case where a horizontally mounted scroll compressor for refrigeration and air conditioning is used, and FIG. 1 shows the entire configuration.
[0019]
To explain this, a scroll-type compression mechanism 2 is provided at one end, an electric motor 3 for driving the compression mechanism 2 is provided at an intermediate part, and an oil reservoir at a lower portion of the closed vessel 1 is provided at the other end. An oil pump 6 for sending out the oil 4 in the lubrication target 5 to the lubrication target portion is provided.
[0020]
The compression mechanism 2 is formed by engaging the blades 11a and 12a of the fixed scroll 11 and the orbiting scroll 12 with each other in the same manner as in the related art. While moving the pair of compression chambers 13A and 13B from the outer peripheral side communicating with the suction port 14 shown in FIGS. 1 to 3 to the inner peripheral side communicating with the discharge port 15, the volume is reduced and compression is performed for discharge.
[0021]
The support and drive and the guide structure of the fluid to be sucked, compressed and discharged in the closed vessel 1 may be configured in any manner. Further, the oil pump 6 may be of any type. In the first embodiment, the compression mechanism 2 integrates the fixed scroll 11 with a main bearing member 9 fixed to one end side by bolting and engages the fixed scroll 11 between the main bearing member 9 and the fixed scroll 11. The combined orbiting scroll 12 is sandwiched. The electric motor 3 includes an annular stator 3a fixed to the closed container 1 by welding or the like, and a rotor 3b disposed inside the stator 3a. The crank for orbitally driving the orbiting scroll 12 of the compression mechanism 2 on the rotor 3b. The shaft 16 is fixed.
[0022]
The crankshaft 16 is supported at the other end of the closed casing 1 by an auxiliary bearing member 17 fixed to the closed casing 1 by welding or the like, and a main shaft 18 on the opposite side is supported by the main bearing member 9. The auxiliary bearing member 17 and the main bearing member 9 have a rolling bearing 21 and a sliding bearing 22 for the bearing. The main shaft 18 is fitted with a revolving shaft 12c projecting at an eccentric position on the back surface of the revolving scroll 12 via an eccentric bearing 23 held so as to be able to reciprocate on a diameter line of the main shaft 18, and the main bearing member is rotated when the main shaft 18 is rotated. In cooperation with the Oldham ring 28 provided between the rotating scroll 9 and the orbiting scroll 12, the orbiting scroll 12 is turned so as to make a circular orbital movement without rotating with respect to the fixed scroll. However, the above bearing structure can be variously changed. The oil pump 6 is attached to the auxiliary bearing member 17.
[0023]
Since the first embodiment is a scroll compressor for refrigeration and air conditioning, the fluid sucked, compressed and discharged by the compression mechanism 2 is a refrigerant, and a chlorine-free refrigerant such as a fluorocarbon hydrogen-based refrigerant is used. In particular, oil 4 compatible with the oil is used. Even if the refrigerant does not have chlorine and lubricity cannot be expected, the oil 4 is compatible with the oil 4 so that the mechanical sliding portion of each part in the closed container 1 is formed by the refrigerant. By being carried, lubricity is improved.
[0024]
A gas suction pipe 32 is connected to the suction port 14, and a gas discharge pipe 34 is connected to the discharge port 15 through a refrigerant passage 33 on the oil reservoir 5 in the sealed container 1.
[0025]
The oil pump 6 is driven by the crankshaft 16 together with the compression mechanism 2, sends out the oil 4 in the oil reservoir 5 to an oil passage 35 formed vertically through the crankshaft 16, and first supplies the oil 4 to the eccentric bearing 23. A part of the oil 4 after being supplied to the eccentric bearing 23 is supplied to the sliding bearing 22 and the compression mechanism 2 through gaps and a predetermined passage in each part, and the rest is returned to the lower oil reservoir 5. .
[0026]
Further, the discharge port 15 is provided with a check valve 42 for preventing the orbiting scroll 12 from rotating backward when the compression mechanism 2 is stopped, and a check valve guide 43 for regulating the movement of the orbiting scroll 12.
[0027]
A condenser 44, an expansion valve 45, a gas-liquid separator 46, a capillary tube 47, and an evaporator 48 are sequentially connected between the gas discharge pipe 34 and the gas suction pipe 32, and a compression mechanism in the closed vessel 1 is connected. 2 including the refrigeration cycle connected in a ring. Although shown as a non-heat pump type for simplicity of description, a heat pump type refrigeration cycle is configured to perform low-load cooling and high-load heating, and has a switching structure (not shown). It is assumed that
[0028]
The fixed scroll 11 is provided with one injection port 51 for performing gas injection into the compression chamber 13 as shown in FIGS. An injection pipe 52 is connected to the injection port 51 via a check valve 54 and a check valve guide 55, and a gas refrigerant supply pipe 53 from the gas-liquid separator 46 is connected to the injection pipe 52. I have. As a result, the gas refrigerant in the gaseous phase separated into gas and liquid by the gas-liquid separator 46 is injected into the compression chamber 13 through the refrigerant supply pipe 53, the injection pipe 52, and the injection port 51, and the reverse flow of the refrigerant once injected is reversed. It is blocked by the stop valve 54. Since such gas injection increases the efficiency of the compressor in the compression mechanism 2, the heating capacity is improved accordingly.
[0029]
In accordance with the diversification of the operation of the refrigeration system, the gas injection may be performed in a timely manner in accordance with the operation state of the refrigeration system. A one-way solenoid valve 56 is provided, and the opening and closing of the refrigeration system is controlled as needed along with the operation of the refrigeration system. This control can be performed by a microcomputer together with, for example, the operation control of the refrigeration apparatus, but is not particularly limited thereto. In addition, in order to diversify the operation, in the first embodiment, in addition to the heat pump type that can also be used for cooling and heating, the electric motor 3 is controlled by, for example, an inverter so that the orbiting scroll 12 can be orbitally driven at a variable speed. It is.
[0030]
Furthermore, while ensuring the performance at low load operation in the gas injection cutoff state, the high injection performance and the large capacity control width are obtained during the heating operation etc. where the high load operation is performed at the low injection pressure while the injection pressure is low. to reason, the pair of compression chambers 13A between the fixed scroll 11 and the speed variable orbiting scroll 12, the blade 11a forming a 13B, of 12a, wherein at a predetermined low speed operation the pair of compression chambers 13A, 13B is defined until spiral length position C1, winding from C2 end end D1, D2 which satisfies the compression ratio, the high speed operation degree with respect to the predetermined low speed operation and release to open the suction port 14 side with one compression chamber 13A a predetermined gap S of depending offset surface 11b of Ru enhances the compression ratio, is provided with 12b.
[0031]
The turning angle of the orbiting scroll 12 changes from 0 ° to 330 ° in the order shown in (a) to (h) of FIG. 3 and returns to (a) at 360 °. And the operation in the cooling mode or the heating mode in which the refrigeration cycle is set is performed.
[0032]
At the time of a low-load operation such as a cooling operation or a low-speed operation, a region that is not sealed by the gap S formed by the offset surfaces 11b and 12b of the pair of compression chambers 13A and 13B formed by the fixed scroll 11 and the orbiting scroll 12 is the gap S Even if it is small, the refrigerant to be drawn in easily escapes to the outside through the gap S, and does not exhibit the closing function in the range where the offset surfaces 11b and 12b are provided. For this reason, there is no supercharging of the refrigerant in a volume corresponding to the entire size of the compression chambers 13A and 13B, and only a range of the compression chambers 13A and 13B that does not have the offset surfaces 11b and 12b works effectively to a predetermined amount. The operation is achieved with high efficiency by the confined volume as designed at low speed operation. Further, the gas injection is not performed and the injection port 51 does not have to be opened in a portion where the offset surfaces 11b and 12b of the compression chambers 13A and 13B are not provided, and a check valve 54 around the injection port 51 is provided here. Since the re-expansion due to the compression of the refrigerant in the dead volume portion including the valve stop chamber 57 and the like can be eliminated, the performance of the compressor at low load operation is improved.
[0033]
On the other hand, during a high-load operation such as a heating operation, which is a high-speed operation, the pair of compression chambers 13A and 13B having the unclosed region is filled with the refrigerant sucked by the small gap S and the high-speed turning of the orbiting scroll 12. The confinement of the refrigerant increases, the suction amount of the refrigerant increases, and the compression ratio is increased in accordance with the high-speed operation degree for the predetermined low-speed operation. Therefore, the compression stroke is supercharged in accordance with the high-speed operation degree for the low-speed operation. In addition, by performing low-pressure gas injection using the entire compression chambers 13A and 13B having a large volume including the areas where the offset surfaces 11b and 12b are present, the cycle-side gas generation amount is reduced as shown in FIG. The reference balance point O0 with respect to the compressor-side gas suction amount is shifted to O1, which is on the low pressure P1 side from the reference pressure P, and the injection flow rate is controlled. Than the flow rate Q0 to ensure a high injection flow rate is shifted to Q1 is a large flow rate side, so are increased needs sufficiently actual refrigerant discharge amount also improves performance during high-load operation of the heating and the like.
[0034]
Therefore, in the first embodiment, the efficiency of the compressor is improved from low load operation to high load operation, and annual power consumption can be reduced. In addition, since the effective volume ratio between the low-capacity operation at low speed and the high-capacity operation at high speed can be increased, the width of the capacity control is expanded, and the versatility is improved. Further, since gas injection is performed in both the pair of compression chambers 13A and 13B, generation of vibration and noise due to imbalance of supercharging can be suppressed, and driving comfort is improved.
[0035]
Further, in the first embodiment, the injection port 51 is moved to an unsealed area of the pair of compression chambers 13A and 13B by changing the state from FIG. 3A to FIG. 3B and changing the state from FIG. As shown by the change in f), the closing function is provided at a position where the closing function is started from near the start time of the closing function that is exhibited according to the high-speed operation degree with respect to the low-speed operation . By doing so, the volume of the unsealed area when the injection port 51 starts to communicate is maximized, so that the influence of the re-expansion of the refrigerant in the dead volume can be minimized. This is effective even if only one of them is implemented.
[0036]
In addition, the time during which the injection port 51 communicates with both of the unsealed areas of the pair of compression chambers 13A and 13B is determined by the changes in (a) to (e) of FIG. 3 and the (e) to (e) of FIG. (H) As shown by the change in (a), they are provided at substantially equal positions. In this way, the injection flow rates to the pair of compression chambers 13A and 13B become substantially equal, and the imbalance of supercharging in the pair of compression chambers 13A and 13B is eliminated, and the driving comfort is further improved.
[0037]
In one embodiment, each of the offset surfaces 11b and 12b has an offset amount of 0.5 mm, a length of the offset in the range of the rotation angle of the orbiting scroll 12 of 180 °, and a diameter of the injection port 51 of 2 or less. .2Mm, turning angle range -2 ° to 163 ° while opening into the compression chamber 13A of the injection port 51, the turning angle range during the opening into the compression chamber 13B is a 178 ° 343 °, both 165 ° and good results were obtained.
[0038]
In the first embodiment, the offset surface 11b is formed to be longer than the orbiting scroll 12 while maintaining the involute shape of the blade 11a, and the extended portion of the offset surface 11b is also formed in the involute shape. Accordingly, the effective area of the compression chamber 13B during the high-speed operation of the orbiting scroll 12 is increased by the extension, and the performance of the compressor under a high load is further improved, and the capacity control range is further expanded.
[0039]
However, it is not essential to provide such an extension, and it may be employed as needed. Also, regardless of whether or not the blade 11a has an extended portion, the offset surface 11b of the blade 11a may be omitted and the offset surface 11b may be provided even if this area is provided on the surface of the blade 12a of the orbiting scroll 12 facing the same. The effect of the setting of the position of the injection port 51 and the effect of the injection timing remain unchanged. The same applies to the other offset surface 12b, which can be omitted and provided on the surface of the opposing blade 11a. In addition, the same operation and effect can be obtained by providing an offset surface in which a necessary offset amount is allocated to a predetermined position on both of the opposing surfaces of the blades 11a and 12a.
[0040]
In the first embodiment, as shown in FIGS. 1 and 2, the muffler 71 covers the outer surface of the compression mechanism 2 having the discharge port 15 in the closed casing 1 in which the compression mechanism 2 and the driving mechanism such as the electric motor 3 are incorporated. When a hole 72 through which an injection pipe 52 connected to the injection port 51 passes with play is provided, the muffler 71 forms a large space between the compression mechanism 2 and the refrigerant discharged from the compression mechanism 2. The muffler 71 once diffused and muffled, in addition to the muffler 71 receiving once at 73 and diffusing and filling the space 73 to muffle the sound, alone or in cooperation with other existing holes. Since the refrigerant inside is shared with the muffler 71 and the next closed space 74 formed by the closed container 1 in a state where it is appropriately narrowed and diffused and filled again, the muffler 71 shares a sound deadening hole. Installation structure of jection pipe 52 can be enhanced silencing effect utilized.
[0041]
(Embodiment 2)
The second embodiment has the same basic configuration as that of the first embodiment, and differs in the opening position of the injection port. Therefore, the same members are denoted by the same reference numerals, and overlapping illustration and description will be omitted.
[0042]
In the second embodiment, as shown in FIG. 5, the turning angle range during opening to one compression chamber 13 </ b > B shown by changes in (f) to (h) in FIG. The injection port 51 is provided at a position smaller than the swivel angle range during opening to the other compression chamber 13A indicated by the changes in a) to (f).
[0043]
Thereby, the offset surface of one of the compression chambers 13B is achieved by injection using both the pair of compression chambers 13A and 13B to improve the capacity at the time of high-speed operation, expand the capacity control width, and balance the supercharging. As shown in FIG. 5, the formation range of 11b is made larger than that of the first embodiment, and the minimum capacity is made smaller so as to be suitable for low-speed operation. The opening area and the opening time of the injection port 51 to the one compression chamber 13B are shortened so that the injection flow rate is reduced, and the expansion of the offset surface 11b suppresses the tendency of the injection gas to flow backward. As a result, it is possible to prevent the injection performance from lowering.
[0044]
The rotation angle range of the injection port 51 during heating while the injection port 51 is open to a region not sealed by the offset surface of the compression chamber, and the change amount of the refrigerant flow rate on the evaporator side with respect to the compression chamber without the offset surface are shown in FIG. 6, there is a certain correlation, and the maximum swivel angle range in which the injection port 51 is open to a region not sealed by the offset surface 11b in the large range of the one compression chamber 13B is smaller than that of the other compression chamber 13A. If it is provided at a position that is 65% or less of the maximum swirl angle range opened to a region that is not sealed by the offset surface 12b, it is preferable because the influence of the backflow of the injection gas is sufficiently suppressed.
[0045]
According to one embodiment, the swivel angle range of the injection port 51 while the injection port 51 is open to the compression chamber 13A indicated by the changes (h), (a) to (h) in FIG. The swivel angle range during opening to one compression chamber 13B is 223 °, which is indicated by changes in FIGS. 5F to 5H, and is 99 ° from 210 ° to 309 °. The maximum swivel angle range open to the region not to be closed is about 44% of the maximum swivel angle range open to the other sealed compression chamber 13A, and favorable results were obtained. Further, the length of the offset surface 11b is 255 ° in the turning angle range . Other data is the same as in the first embodiment.
[0046]
(Embodiment 3)
Embodiment 3, if the basic structure of the first embodiment are common, the size relationship of the turning angle range during the opening against the pair of compression chambers of the injection port, carried Of the second embodiment. Therefore, a description will be given with reference to the drawings and reference numerals of the first embodiment.
[0047]
The injection port 51 is provided at a position where the swivel angle range when the one compression chamber 13A is open to the unsealed area is larger than the swivel angle range when the one compression chamber 13B is open to the other compression chamber 13B. By doing so, the long-term low-pressure gas injection into one compression chamber 13B of the pair of compression chambers 13A and 13B suppresses the problem of the backflow of the refrigerant due to the lack of sealing, and the overall injection A sufficient amount can be secured, and the performance in high-load operation such as during heating can be further improved.
[0048]
【The invention's effect】
According to one feature of the present invention, during a low-load operation at a predetermined low-speed operation, both the pair of compression chambers formed by the fixed scroll and the orbiting scroll exhibit a closing function in a range where the offset surface is provided. There is no supercharging of the refrigerant in a volume commensurate with the overall size of the compression chamber, and only the area that does not form an offset surface works effectively to achieve a small confined volume as designed at a predetermined low-speed operation. In addition to achieving high efficiency in operation, gas injection is not performed in the part that works effectively in this low speed operation and the gas injection port does not open, so the dead volume including the check valve etc. around the injection port here Since there is no re-expansion due to the compression of the refrigerant in the portion, the performance of the compressor under low load operation is improved. At the time of high-load operation, which is high-speed operation, the pair of compression chambers sucked according to the degree of high-speed operation with respect to the predetermined low-speed operation due to the small gap that keeps them from being sealed and the high-speed turning of the orbiting scroll. Since the confinement of the refrigerant is improved and the suction amount of the refrigerant is increased to increase the compression ratio, the compression stroke is supercharged according to the high-speed operation degree with respect to the low-speed operation, and includes a region having the offset surface. By performing low-pressure gas injection using the entire compression chamber with a large volume, a high injection flow rate can be secured, and the actual refrigerant discharge amount can be sufficiently increased. Performance also improves.
[0049]
Therefore, the efficiency of the compressor is improved from low-load operation to high-load operation, and annual power consumption can be reduced. In addition, a gas that utilizes a large effective volume ratio between low-capacity operation at low speed and high-capacity operation at high speed, and a wide swivel angle range while open to both the pair of compression chambers. Since injection can be performed, the capacity control range is expanded, and the responsiveness to diversification of driving is improved. Further, since gas injection is performed to both of the pair of compression chambers, generation of vibration and noise due to imbalance of supercharging can be suppressed, and driving comfort is improved.
[0050]
In this case, if the injection port is provided at a position where the injection port starts to communicate with the unsealed region of the pair of compression chambers from near the start time of the closing function exhibited according to the high-speed operation degree , the injection port is not sealed when the injection port starts to communicate. Since the volume of the region is maximized, the influence of the refrigerant re-expanded at the dead volume can be minimized, and it is effective to perform only one of the operations.
[0051]
Further, if the injection port is provided at a position where the time during which the injection port communicates with both of the unsealed areas of the pair of compression chambers is substantially equal, the injection flow rates to the pair of compression chambers are substantially equal, and The imbalance of the supercharging in the compression chamber is eliminated, and the driving comfort is further improved.
[0052]
According to another feature of the present invention, the injection using both the pair of compression chambers enhances the capacity at the time of high-speed operation, expands the capacity control range, and balances the supercharging while one of the compression chambers is used. By increasing the range of formation of the offset surface and reducing the minimum capacity so as to be suitable for lower speed operation, the capacity control range is expanded, and the opening area of the injection port to one of the compression chambers and It is possible to reduce the injection flow rate by shortening the opening time, to suppress the injection gas from easily flowing backward due to the expansion of the offset surface, and to prevent the injection performance from deteriorating due to the reverse flow of the refrigerant.
[0053]
In this case, the injection port is provided at a position where the maximum swing angle range opened to the unsealed area of one compression chamber is 65% or less of the maximum swing angle range opened to the unsealed area of the other compression chamber. Accordingly, the influence of the backflow of the refrigerant at the time of gas injection can be sufficiently suppressed.
[0054]
According to still another feature of the present invention, the gas injection at a low pressure for one of the pair of compression chambers at a low pressure for a long time suppresses the problem of the backflow of the refrigerant due to the non-sealing, and the injection amount as a whole is sufficiently increased. , And performance in high-load operation such as during heating can be further improved.
[0055]
According to another feature of the present invention, the sound deadening effect can be enhanced by using the installation structure of the injection pipe.
[Brief description of the drawings]
FIG. 1 is a vertical sectional view of a scroll compressor according to a first embodiment of the present invention.
FIG. 2 is a sectional view of a main part of the compressor of FIG.
FIG. 3 is an explanatory diagram showing a progress state of compression in a compression chamber of the compressor of FIG. 1 and a change in an opening position of an injection port.
FIG. 4 is a graph showing a balance point between a cycle-side gas generation amount and a compressor-side gas suction amount, and a relationship between an injection pressure and an injection flow rate.
FIG. 5 is an explanatory diagram showing a state of progress of compression in a compression chamber of a compressor and a change in an opening position of an injection port according to a second embodiment of the present invention.
FIG. 6 is a graph showing a relationship between an offset amount of a scroll blade and a refrigerant circulation amount on an evaporator side.
[Explanation of symbols]
2 Compression mechanism 3 Electric motor 11 Fixed scroll 11a Blade 11b, 12b Offset surface 12 Orbiting scroll 12a Blade 13A, 13B Compression chamber 14 Suction port 15 Discharge port 51 Injection port

Claims (7)

In a scroll compressor that performs gas injection through an injection port into a compression chamber formed between a fixed scroll and a orbiting scroll that moves in a circular orbit,
The blades forming a pair of compression chambers between the fixed scroll and the orbiting scroll with variable speed, from a spiral length position where the pair of compression chambers satisfy a specified compression ratio to a winding end at a predetermined low-speed operation. , each of the compression chambers to open the inlet side with a predetermined gap offset surface Ru increase the compression ratio in accordance with the high-speed operation degree with respect to the predetermined low speed operation is provided, sequentially in a closed non regions of the pair of compression chambers A scroll compressor, comprising: an injection port at a communication position; and control means for appropriately shutting off gas injection and canceling the shutoff. 2. The scroll compressor according to claim 1, wherein the injection port is provided in at least one of the pair of compression chambers in an unsealed region at a position starting from near a start point of a closing function performed according to the high-speed operation degree . 3. The scroll compressor according to any one of claims 1 and 2, wherein the injection port is provided at a position where times during which the injection port communicates with both of the pair of compression chambers are substantially equal. In a scroll compressor that performs gas injection through an injection port into a compression chamber formed between a fixed scroll and a orbiting scroll that moves in a circular orbit,
The blades forming a pair of compression chambers between the fixed scroll and the orbiting scroll with variable speed, from a spiral length position where the pair of compression chambers satisfy a specified compression ratio to a winding end at a predetermined low-speed operation. , each of the compression chambers to open the inlet side with a predetermined gap offset surface Ru increase the compression ratio in accordance with the high-speed operation degree with respect to the predetermined low speed operation is provided, sequentially in a closed non regions of the pair of compression chambers Injection into a position where the swivel angle range while communicating with and opening to one unsealed area of the pair of compression chambers is smaller than the swiveling angle range while opening to the unsealed area of the other compression chamber. A scroll compressor comprising a port and a control means for shutting off gas injection and releasing the shutoff. The injection port is provided at a position where the maximum swing angle range opened to the unsealed area of one compression chamber is 65% or less of the maximum swing angle range opened to the unsealed area of the other compression chamber. The scroll compressor according to claim 4. In a scroll compressor which performs gas injection through an injection port to a compression chamber between a fixed scroll and an orbiting scroll,
The blades forming a pair of compression chambers between the fixed scroll and the orbiting scroll with variable speed, from a spiral length position where the pair of compression chambers satisfy a specified compression ratio to a winding end at a predetermined low-speed operation. , each of the compression chambers to open the inlet side with a predetermined gap offset surface Ru increase the compression ratio in accordance with the high-speed operation degree with respect to the predetermined low speed operation is provided, sequentially in a closed non regions of the pair of compression chambers The injection port is located at a position where the swivel angle range when communicating with and opening to the unsealed area of the one compression chamber is larger than the swiveling angle range when opening to the unsealed area of the other compression chamber. A scroll compressor, comprising a control means for shutting off gas injection and canceling the shutoff. 7. A muffler for covering an outer surface having a discharge port of a compression mechanism in a sealed container having a compression mechanism and a drive mechanism built therein, wherein a hole through which an injection pipe connected to an injection port passes with play is provided. A scroll compressor according to any one of the preceding claims.

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