WO1999064744A1

WO1999064744A1 - Multi-stage capacity control scroll compressor

Info

Publication number: WO1999064744A1
Application number: PCT/JP1999/002761
Authority: WO
Inventors: Kenji Matsuba; Shigeki Hagiwara; Yoshitaka Shibamoto; Hiroyuki Kuroiwa
Original assignee: Daikin Industries, Ltd.
Priority date: 1998-06-12
Filing date: 1999-05-26
Publication date: 1999-12-16
Also published as: CN1272906A; EP1004773A1; EP1004773A4; JPH11351167A; ES2356224T3; EP1004773B1; KR20010022824A; CN1094566C; JP2974009B1; KR100601270B1; DE69943017D1

Abstract

An asymmetrical volute type scroll compressor, wherein a first bypass valve (27) for setting a discharge capacity to 60 % is installed in a first scroll (21) and a second bypass valve (40) for setting a compressor set load to 50 % is installed outside the volute of the first scroll (21) by communication between a suction side and a discharge side, the first and second bypass valves (27, 40) are closed so as to set a substantial load of the compressor to 100 %, the first bypass valve (27) is open and the second bypass valve (40) is closed so as to set the substantial load of the compressor to 60 %, the first and second bypass valves (27, 40) are opened so as to set the substantial load of the compressor to 30 %, namely a volume percent Vr in operation at the minimum capacity is set at 1 or more so as to perform a reliable operation under a partial load of 50 % or less, whereby the operation under a load of 50 % or less can be changed in multiple stages.

Description

Description Multi-stage capacity control scroll compressor Technical field

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-stage displacement control scroll compressor that enables a partial load operation in a low displacement range. Background art

Conventionally, there is a scroll compressor shown in FIGS. 8 and 9 (a cross-sectional view taken along the line XX in FIG. 8) as a scroll compressor in which a bypass hole is provided in a spiral to enable a partial load operation (Japanese Patent Application Laid-Open No. Japanese Patent Application Publication No. 1705703). This scroll compressor is an asymmetric scroll type scroll compressor in which the end of the spiral of the first scroll 1 is longer than the end of the spiral of the second scroll 2 by π (rad) in the expansion angle. Then, a first fluid working chamber A formed by the inner surface of the first scroll 1 and the outer surface of the second scroll 2 and a second fluid working chamber formed by the outer surface of the first scroll 1 and the inner surface of the second scroll 2 The chamber B and the force S are alternately opened and closed with respect to the single low-pressure board 3, and approximately one turn from the outermost contact point E of the second scroll 2 with respect to the first scroll 1. A common bypass hole 4 common to the first fluid working chamber A and the second fluid working chamber B is provided at a point J that is rewound inward.

The first scroll 1 is provided with a valve hole 5 communicating with the common bypass hole 4, and a bypass passage 6 communicating with the low-pressure port 3 is provided on a side portion of the valve hole 5. In the valve hole 5, a stepped cylindrical bypass valve 7 for opening and closing the common bypass hole 4 is slidably provided. A coil spring 8 is locked at the step of the bypass valve 7, and the upper part of the bypass valve 7 is sealed by a lid member 9 and is separated from the discharge dome 10. Has formed. The operating pressure chamber 11 is connected to an operating pressure line 15 selectively connected to a low pressure line 13 and a high pressure line 14 by an electromagnetic valve 12 via a joint pipe 16. I have. Reference numeral 17 denotes a capillary tube for preventing a short circuit between the high-voltage line 14 and the low-voltage line 13, and reference numeral 18 denotes a case. And 19 is a high pressure port.

As described above, the common bypass hole 4 is provided at the point J where the outermost contact point E of the second scroll 2 with respect to the first scroll 1 is rewound inward by approximately one turn from the force E. I have. Therefore, when the solenoid valve 12 is closed and high-pressure gas is supplied to the operation pressure chamber 11 of the bypass valve 7 and the bypass valve 7 is closed, the discharge capacity becomes the full capacity (100%). On the other hand, when the solenoid valve 12 is opened and the low-pressure gas is supplied to the operating pressure chamber 11 of the bypass valve 7 to open the bypass valve 7, the position of the common bypass hole 4 becomes the compression start point. The discharge capacity is about 60% of the total capacity. Thus, the discharge capacity of the scroll compressor can be switched between 100% and 60%. Note that the position where the outermost contact point E of the second scroll 2 with respect to the first scroll 1 is rewound inward by approximately 3/4 turn, and the position where it is rewound inward by 1 turn. By providing two common bypass holes in the device, three kinds of discharge capacities of 100%, 70%, and 60% can be obtained.

The conventional multi-stage capacity-controlled scroll compressor has the following problems. First, there is a problem that the operation range is limited because the volume ratio Vr becomes considerably small during the partial load operation of 50% or less.

For example, when the specific volume ratio Vr of the first and second scrolls 1 and 2 is Vr = 2.3, the volume ratio Vr of the compressor is required to be 1 or more even at a partial load. However, the limit partial load factor is 1/2/3 = 0.44, that is, 44% operation is the limit. Increasing the specific volume ratio Vr lowers the critical partial load factor and enables partial load operation of 50% or less.However, in that case, the efficiency at full load decreases. It is not possible to increase the specific volume ratio Vr. However, in the case of a multi-type air conditioner in which one outdoor unit handles multiple indoor units, it is 20 ° /. 330% load operation is always required, and when the conventional multi-stage capacity-controlled scroll compressor is applied to the multi-type air conditioner, the operation of the compressor is frequently stopped. However, problems such as the inability to set optimal air conditioning conditions occur.

Further, as a load control scroll compressor, there is a method using inverter control of an electric motor in addition to the above-described configuration. However, in that case, an inverter circuit is required, which leads to a significant cost increase. Also, especially for large inverters In addition, there is a problem that harmonics are generated. Furthermore, there is a problem of poor lubrication during the inverter operation, which causes a problem that the reliability of the compressor is reduced.

Also, as described above, if a large number of common bypass holes are provided to achieve low partial load operation of 50% or less, workability and assemblability may be reduced, and common bypass holes may be provided at the center of the first and second scrolls. , The rigidity is reduced. In addition, the gas load in the spirals of the first and second scrolls is significantly reduced, and the balance between the gas load and the centrifugal load of the second scroll on the movable side is lost, resulting in poor lubrication in pin bearings (not shown). And the like, and the second scroll may be overturned. Disclosure of the invention

SUMMARY OF THE INVENTION An object of the present invention is to provide an inexpensive and highly reliable multi-stage displacement scroll compressor capable of changing a partial load operation of 50% or less into multiple stages. In order to achieve the above object, a multi-stage displacement control scroll compressor according to the present invention includes a first bypass passage formed at a predetermined position in a compression chamber and returning compressed gas in a fluid working chamber to a suction port; A first opening / closing means for opening / closing the bypass passage, a second bypass passage communicating between the discharge side and the suction side, and opening / closing the second bypass passage. A second opening / closing means is provided.

According to the above configuration, when the second opening / closing means opens and closes the second bypass passage, the load on the compressor is switched between 100% and the first predetermined percentage. On the other hand, when the first opening / closing means opens and closes the first bypass passage, the discharge capacity of the compressor is switched between 100% and the second predetermined%. Therefore, by combining the opening and closing of the first opening / closing means and the opening / closing of the second opening / closing means, the substantial load of the compressor can be switched to four stages. In this case, the discharge capacity of the compressor is switched to only the second predetermined percentage by the first opening / closing means. Therefore, the fixed volume ratio of the compressor and the second predetermined percentage are set so that the volume ratio when the discharge capacity of the compressor reaches the second predetermined percentage becomes 1 or more. If this is done, keep the volume ratio at 1 or more even when the actual load on the compressor is minimized. And reliable multi-stage load control is performed.

In one embodiment of the multi-stage displacement control scroll compressor of the present invention, the first scroll and the second scroll forming the compression chamber have a spiral end of one scroll larger than a spiral end of the other scroll. It is characterized by exhibiting an asymmetric spiral shape with an extension angle of 180 degrees.

According to the above configuration, the first fluid working chamber formed by the inner surface of the first scroll and the outer surface of the second scroll, and the second fluid formed by the outer surface of the first scroll and the inner surface of the second scroll The working chambers are alternately formed at the same position of the first bypass passage. Therefore, the high-pressure gas in each fluid working chamber is returned to the suction port from only one first bypass passage.

In one embodiment of the multi-stage displacement control scroll compressor according to the present invention, the second bypass passage is provided outside the compressor body. According to the above configuration, the second bypass passage and the second opening / closing means do not need to be formed in the compressor main body, but may be formed between the discharge line and the suction line. Therefore, a multi-stage displacement control scroll compressor is manufactured at low cost.

One embodiment of the multi-stage displacement control scroll compressor according to the present invention is characterized in that a plurality of the second bypass paths and a plurality of second opening / closing means are provided.

According to the configuration, a plurality of the second bypass passages and the second opening / closing means are provided. Therefore, by combining the opening and closing of each of the second opening and closing means and the opening and closing of the first opening and closing means, multi-stage load control of eight or more stages is performed.

In one embodiment of the multi-stage displacement control scroll compressor according to the present invention, the second opening / closing means for opening / closing the second bypass passage is a motor-operated valve that can be controlled to an arbitrary opening.

According to the above configuration, the opening of the second bypass passage is set to an arbitrary opening, so that the load on the compressor is switched between 100% and an arbitrary%. Therefore, the substantial load of the compressor can be switched to any multi-stage by a combination of the opening / closing control of the first opening / closing means and the opening control of the second opening / closing means.

In one embodiment of the multistage displacement control scroll compressor according to the present invention, the second opening / closing means includes a difference between a pilot pressure and the suction side pressure or the discharge side pressure. It is characterized by being operated by pressure.

According to the above configuration, the control system of the second opening / closing means can be simply configured, and the multi-stage capacity control scroll compressor is manufactured at low cost.

Further, one embodiment of the multi-stage displacement control scroll compressor according to the present invention is characterized in that a liquid injection pipe for cooling a low-pressure chamber communicating with the suction port is provided.

According to the above configuration, the low-pressure chamber and the drive motor are cooled by the cooling liquid injected from the liquid injection pipe. Thus, the rise in the temperature of the low-pressure chamber caused by returning the high-pressure gas in the compression chamber to the suction port is prevented, and the temperature of the discharge gas and the motor is reduced.

In one embodiment of the multistage displacement control scroll compressor according to the present invention, the first opening / closing means and the second opening / closing means are operated by a pipe pressure, and a pilot of the first opening / closing means is provided. The port and the pilot port of the second opening / closing means are characterized by being connected to each pilot line via one joint fitting provided at the upper center of the compressor body.

According to the above configuration, only one joint fitting for connecting the pilot ports of the first and second opening / closing means and the respective pilot lines is required to be provided at the upper center of the compressor body, and at the center of the casing top at one location It is taken out from. For this reason, when the casing top is taken out from two eccentric locations, welding of the casing top and the operation pipe is required compared to the case where two elliptical weldings to the operation pipe are required. Can be performed easily, the number of assembly steps is reduced, and the cost is further reduced.

One embodiment of the multi-stage capacity control scroll compressor according to the present invention includes a standard scroll compressor having a fixed discharge capacity, wherein the multi-stage capacity control scroll compressor and the standard scroll compressor are provided. And a compressor connected in parallel.

According to the above configuration, the multi-stage displacement scroll compressor and the standard scroll compressor constitute a twin multi-stage displacement scroll compressor. Therefore, switching to the two load states of unloading and full load by the above-mentioned standard scroll compressor, and n-stage load switching by the multi-stage capacity control scroll compressor By changing the load, the load is switched in 2 X n stages. In this way, load control is performed in multiple stages.

In one embodiment of the multi-stage displacement control scroll compressor according to the present invention, the first opening / closing means operates at a pilot pressure, and a pilot port of the first opening / closing means and the pilot port. It is characterized in that it is connected to the fittings for connecting the pilot line to the port port with screws.

According to the above configuration, the pilot port of the first opening / closing means and the fitting are securely connected by the taper screw. Therefore, a mounting structure that is resistant to vibration of the joint fitting and has high leakage resistance and heat resistance is realized. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a partial cross-sectional view of a first embodiment of a multistage displacement control scroll compressor according to the present invention.

FIG. 2 is a partial cross-sectional view when the discharge capacity of the multi-stage displacement control squeal compressor shown in FIG. 1 is 30%.

FIG. 3 is a partial cross-sectional view of a multi-stage displacement scroll compressor different from FIG.

FIG. 4 is a cross-sectional view of a multi-stage capacity control squeal compressor according to the second embodiment.

FIG. 5 is a partial cross-sectional view of a multi-stage displacement control scroll compressor different from FIG.

FIG. 6 is a configuration diagram of a multi-stage capacity control scroll compressor according to the third embodiment.

FIGS. 7A and 7B are diagrams showing a mounting structure different from the mounting structure of the joint pipe to the lid member in FIGS. 1 and 3 to 5.

FIG. 8 is a partial cross-sectional view of a conventional load control scroll compressor.

FIG. 9 is a cross-sectional view taken along the line XX of FIG. BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments. FIG. 1 is a partial cross-sectional view of a multi-stage displacement control scroll compressor according to a first embodiment. 1st scroll 21, 2nd scroll 22, low pressure port 23, common bypass hole 24, valve hole 25, bypass passage 26, bypass valve 27, coil spring 28, lid member 29, Discharge dome 30, operating pressure chamber 31, solenoid valve 32, low pressure line 33, high pressure line 34, operating pressure line 35, joint pipe 36, cabillary tube 37, casing 38 And the high-pressure port 39 are the first scroll 1, the second scroll 2, the low-pressure port 3, the common bypass hole 4, and the valve in the conventional asymmetric spiral multi-stage capacity control scroll compressor shown in Figs. Hole 5, bypass passage 6, bypass valve 7, coil spring 8, lid member 9, discharge dome 10, operating pressure chamber 11, solenoid valve 12, low pressure line 13, high pressure line 14, operating pressure line It has the same configuration as 15, fitting tube 16, capillary tube 17, casing 18 and high pressure port 19, and operates in the same way That.

In the present embodiment, a second bypass valve 4 for selectively communicating between the suction side communicating with the low-pressure port 23 and the discharge side in the discharge dome 30 outside the spiral in the first scroll 21. 0 is provided. Hereinafter, the bypass valve 27 is referred to as a first bypass valve, and the bypass valve 40 is referred to as a second bypass valve. The second bypass valve 40 has a cylindrical cylinder portion 42 protruding from the high pressure side surface of the end plate 41 of the first scroll 21, and a cylinder portion 42 having a ball at the tip. It is roughly constituted by a sliding valve body 43 and a spring 44 contracted between the valve body 43 and the cylinder part 42.

The low pressure side end of the cylinder portion 42 has a shaft hole communicating with the inside of the cylinder portion 42, and a mounting portion 42a provided with a mounting screw on the outer peripheral surface. The end plate 41 is provided with a through hole 45 penetrating the end plate 41, and a mounting hole for fitting the mounting portion 4 2a of the cylinder portion 42 to the upper end of the through hole 45. 45 5a is provided. Then, by screwing the mounting portion 42 a of the cylinder portion 42 into the mounting hole 45 a of the end plate 41, the cylinder portion 42 protrudes from the surface on the high pressure side of the end plate 41 and is fixed. The suction side and the inside of the cylinder portion 42 communicate with each other through the through hole 45 and the shaft hole of the mounting portion 42a. The upper part of the cylinder part 42 is partitioned from the discharge dome 30 to form an operation pressure chamber 46. The operating pressure chamber 46 contains a second solenoid valve. An operation pressure line 48 selectively communicated with the low pressure line 33 and the high pressure line 34 by 47 is connected via a joint pipe 49. Hereinafter, the solenoid valve 32 is referred to as a first solenoid valve, and the solenoid valve 47 is referred to as a second solenoid valve. Reference numeral 50 denotes a capillary tube for preventing a short circuit between the high voltage line 34 and the low voltage line 33.

A step portion having a small diameter on the low pressure side is provided on the outer peripheral surface of the valve body 43, and a spring 44 is mounted on the small diameter portion. Further, a through hole 51 communicating the inside and the outside in the radial direction is provided in the axial middle portion of the cylinder portion 42, and when the valve body 43 slides to the lowermost position, the valve body 43 is closed. The large-diameter portion closes the through hole 51 of the cylinder portion 42. Here, the size of the through hole 51 is set such that the load on the compressor is, for example, 50%.

Therefore, when the second solenoid valve 47 is closed and high-pressure gas is supplied to the operating pressure chamber 46 of the second bypass valve 40 and the valve body 43 is slid downward, the valve body 4 The large diameter portion of 3 closes the through hole 51, and the load of the compressor is set to 100% (hereinafter, the load thus set is referred to as a set load). On the other hand, when the second solenoid valve 47 is opened to supply low-pressure gas to the operating pressure chamber 46 of the second bypass valve 4◦ and the valve body 43 is slid upward, the valve body 4 The through hole 51 of 3 is opened, and the set load of the compressor becomes 50%. That is, in the present embodiment, the second bypass passage is constituted by the through hole 45, and the second opening / closing means is constituted by the second bypass valve 40.

The multi-stage displacement control scroll compressor having the above-described configuration enables multi-stage load control as follows by controlling the opening and closing of the first bypass valve 27 and the second bypass valve 40. First, by closing the second solenoid valve 47 as described above, the second bypass valve 40 is closed, and the set load of the compressor becomes 100%. In this state, when the first solenoid valve 32 is closed and high-pressure gas is supplied to the operating pressure chamber 31 of the first bypass valve 27, the first bypass valve 27 is closed and the discharge capacity is 100%. And Therefore, the real load of the compressor in this case is 100% (== 100% XI 00%) (the state of FIG. 1). When the first solenoid valve 32 is opened and low-pressure gas is supplied to the operating pressure chamber 31 of the first bypass valve 27, the first bypass valve 27 is opened and the discharge capacity becomes 60%. . Therefore, the actual negative load of the compressor in this case is The load is 60% (= 100% X 60%). Next, by opening the second solenoid valve 47, the second bypass valve 40 is opened, and the set load of the compressor becomes 50%. In this state, when the first solenoid valve 32 is opened and the first bypass valve 27 is opened, the discharge capacity becomes 60%. Therefore, the actual load of the compressor in this case is 30% (= 50% X 60%) (the state in FIG. 2).

In this case, the first scroll 21 has a point J (see FIG. 9), which is rewound inward by approximately one turn from the outermost contact point E of the second scroll 22 with respect to the first scroll 21. ), The first bypass valve 27 is provided by drilling only one common bypass hole 24. Therefore, the discharge capacity during the minimum capacity operation is 60%. Therefore, when the specific volume ratio Vr of the first and second scrolls 21 and 22 is 2.3, the volume ratio Vr at the time of the minimum capacity operation is 1.38 (= 2.3 X 0 6) and exhibit a value of “1” or more. That is, according to the present embodiment, highly reliable partial load operation of 50% or less can be performed.

As described above, in the present embodiment, the first scroll 21 of the asymmetric spiral scroll compressor has the second scroll 2 with respect to the first scroll 21.

At point J (see FIG. 9), which is wound back approximately one turn inward from the outermost contact point E of 2, (see FIG. 9), the discharge capacity is 60 by communicating with the low pressure port 23. A first bypass valve ₂₇ for setting / ₀ is provided. Further, a second bypass valve 40 for selectively setting the suction side and the discharge side to communicate with each other outside the spiral of the first scroll 21 to set the set load of the compressor at 50% is provided. By opening and closing the first solenoid valve 32 and the second solenoid valve 47, the first bypass valve 27 and the second bypass valve 27 The bypass valve 40 is opened and closed. Therefore, if the second bypass valve 40 and the first bypass valve 27 are closed, the actual load on the compressor can be reduced to 100%. Also, if the second bypass valve 40 is closed and the first bypass valve 27 is opened, the actual load on the compressor can be reduced to 60%. Further, when the second bypass valve 40 and the first bypass valve 27 are opened, the actual load of the compressor can be reduced to 30%.

That is, according to the present embodiment, it is possible to perform highly reliable partial load operation of 50% or less by setting the volume ratio Vr at the time of the minimum capacity operation to “1” or more. In such a case, the multi-stage capacity control scroll compressor having the above-described configuration can

(1) A conventional asymmetric spiral type multi-stage capacity control scroll having a bypass valve (27) is provided with a through hole (45) penetrating the end plate (41) outside the spiral of the first scroll (21) in the compressor. A simple configuration can be achieved simply by screwing the mounting portion 42a of the cylinder portion 42 to the upper end. In addition, the second scroll valve 40 provided outside the spiral does not require the same precision as the first scroll valve 27 provided inside the spiral. Therefore, it can be provided inexpensively with a small number of parts.

FIG. 3 is a partial cross-sectional view showing a modified example of the multi-stage capacity control squeal compressor shown in FIG. The first scroll 61, the second scroll 62, the first bypass valve 63, the first solenoid valve 64, the low-pressure line 65, and the high-pressure line 66 in the multistage displacement scroll compressor shown in Fig. 3 The operating pressure line 67, the high pressure port 68, the second bypass valve 69, the through hole 70, the second solenoid valve 71, and the operating pressure line 72 are used in the multistage displacement control scroll compressor shown in FIG. 1st scroll 21, 2nd scroll 22, 1st bypass valve 27, 1st solenoid valve 32, low pressure line 33, high pressure line 34, operating pressure line 35, high pressure port 39, (2) It has the same configuration as the bypass valve 40, the through hole 45, the second solenoid valve 47, and the operation pressure line 48, and operates similarly.

In the present embodiment, the first and second bypass valves 63 and 72 are connected via one joint pipe 74 attached to the center of the top surface of the casing 73 with the operating pressure lines 67 and 72. 6 Connected to 9. Two holes 74a and 74b are provided alternately in the joint pipe 74, and the operation pressure line 67 is connected to the first hole 74a by the first pipe bolt joint 75. On the other hand, an operating pressure line 72 is connected to the second hole 74 b by a second pipe bolt joint 76. Further, an operating pressure chamber 78 of the first bypass valve 63 is connected to the first hole 74 a by a first pipe 77, and a second bypass valve 79 is connected to the second hole 74 b by a second pipe 79. The operation pressure chamber 80 of 69 is connected.

In this way, the two operating pressure lines 67, 72 are combined with one joint pipe 74 and pulled out from the center of the top of the casing 73, thereby reducing assembly man-hours and further reducing costs. You can do it.

FIG. 4 is a partial cross-sectional view illustrating a multi-stage displacement control scroll compressor according to the second embodiment. First scroll 81, Second scroll 82, Low pressure port 83, Bar The bypass valve 84, the first solenoid valve 85, the low pressure line 86, the high pressure line 87, the operating pressure line 88, the joint pipe 89 and the high pressure port 90 are the multi-stage displacement control scrolls shown in Fig. 1. First scroll 21, second scroll 22, low pressure port 23, first bypass valve 27, first solenoid valve 32, low pressure line 33, high pressure line 34, operating pressure line 35 in compressor , Has the same configuration as the joint pipe 36 and the high-pressure port 39, and operates similarly. In the multi-stage displacement control scroll compressor shown in FIG. 1, a second bypass valve 40 is provided above a through hole 45 formed in the end plate 41 of the first scroll 21, and a second bypass valve 40 is provided. The set load of the compressor is switched between 100% and 50% by selectively opening and closing the suction port and the suction side and the discharge side. However, the selective communication between the suction side and the discharge side can be performed by other methods. In FIG. 4, the low-pressure line 86 and the high-pressure line 87 are connected by a bypass passage 93 provided with a second solenoid valve 91 and a capillary tube 92, so that the suction side and the discharge side are connected. It allows selective communication with the side. In addition, the above-mentioned capillary tube 92 prevents a short circuit between the high-pressure line 87 and the low-pressure line 86. Hereinafter, for example, a case in which the second solenoid valve 91 is configured so that the set load of the compressor when the second solenoid valve 91 is opened is 50% will be described as an example of the multi-stage capacity control scroll compressor according to the present embodiment. The operation will be described.

The multi-stage capacity control scroll compressor performs multi-stage load control as follows by controlling the opening and closing of the first solenoid valve 85 and the second solenoid valve 91. First, by closing the second solenoid valve 91, the set load of the compressor becomes 100%. When the first solenoid valve 85 is closed in this state, the first bypass valve 84 is closed, and the discharge capacity becomes 100%. Therefore, the actual load of the compressor in this case is 100%. Further, when the first solenoid valve 85 is opened, the first bypass valve 84 is opened, and the discharge capacity becomes 60%. Therefore, the actual load of the compressor in this case is 60%. Next, by opening the second solenoid valve 91, the set load of the compressor becomes 50%. In this state, when the first solenoid valve 85 is opened, the discharge capacity becomes 60%. Therefore, the actual load on the compressor in this case is 30%. In this way, as in the case of the first embodiment, the volume ratio Vr at the time of the minimum capacity operation is set to a value equal to or more than “1”, and a highly reliable partial load operation of 50% or less is performed. You can do it.

In the above embodiment, the suction side and the discharge side are connected by a very simple method of connecting the low pressure line 86 and the high pressure line 87 with a bypass passage 93 provided with a second solenoid valve 91. It allows selective communication with the side. Therefore, unlike the first embodiment, there is no need to provide the second bypass valve 40 in the compressor main body, and the cost can be further reduced.

Note that, by using an electric valve whose opening can be controlled by a stepping motor or the like instead of the second solenoid valve 91, the set load of the compressor can be arbitrarily changed in multiple stages. Therefore, in this case, by combining the opening and closing of the first solenoid valve 85, it is possible to perform a reliable multi-stage load control of 50% or less with high reliability.

FIG. 5 is a partial cross-sectional view showing a modification of the multi-stage capacity control squeal compressor shown in FIG. First scroll 101, second scroll 1◦2, low-pressure port 103, bypass valve 104, first solenoid valve 105, low-pressure line in the multi-stage displacement control scroll compressor shown in Fig. 5 106, high-pressure line 107, operating pressure line 108, fitting tube 109 and high-pressure port 110 are the first scroll in the multi-stage capacity control scroll compressor shown in Fig. 1. , 2nd scroll 22, low pressure port 23, 1st no-pass valve 27, 1st solenoid valve 32, low pressure line 33, high pressure line 34, operating pressure line 35, joint pipe 36 and high pressure port It has the same configuration as 39 and operates similarly. However, it is assumed that the bypass valve 104 is provided at a position where the discharge capacity is set to 50%.

In FIG. 5, the low-pressure line 106 and the high-pressure line 107 are connected to each other by a bypass passage 1 provided with a second solenoid valve 111 for setting the set load of the compressor to 75% when the compressor is opened. 1 3 and the bypass passage 1 1 4 with the 3rd solenoid valve 1 1 2 to set the load of the compressor at the time of opening to 65%. Then, by controlling the opening and closing of the first solenoid valve 105, the second solenoid valve 111, and the third solenoid valve 112, multi-stage load control is performed as follows.

First, the set load of the compressor becomes 100% by closing the second solenoid valve 111 and the third solenoid valve 112. When the first solenoid valve 105 is closed in this state, The first bypass valve 104 closes, and the discharge capacity becomes 100%. Therefore, the actual load of the compressor in this case is 100 ° / ₀ . When the first solenoid valve 105 is opened, the first bypass valve 104 is opened and the discharge capacity becomes 50%. Therefore, the actual load on the compressor in this case is 50%. Next, by closing the third solenoid valve 112 while opening the second solenoid valve 111, the set load of the compressor becomes 75%. When the first solenoid valve 105 is closed in this state, the discharge capacity becomes 100%. Therefore, the actual load of the compressor in this case is 75%. Next, by opening the second solenoid valve 11 1 and the third solenoid valve 112, the set load of the compressor becomes 49% (= 75% X 65%). When the first solenoid valve 105 is opened in this state, the discharge capacity becomes 50%. Therefore, the actual load of the compressor in this case is 24% (= 75% X65% X50%). Thus, by setting the volume ratio Vr at the time of the minimum capacity operation to a value of “1” or more, highly reliable multi-stage load control of 50% or less can be performed. In the above description, four-stage load control has been described as an example, but a maximum of eight stages of load control is possible.

FIG. 6 is a configuration diagram of a multi-stage capacity control scroll compressor according to the third embodiment. In this embodiment, a multi-stage capacity control scroll compressor (hereinafter referred to as a capacity controller) having any one of the above embodiments and a scroll compressor (hereinafter referred to as a non-capacity control) having a standard structure (non-capacity control) , Standard equipment) to perform high multi-stage load control of 50% or less.

The standard compressor 1 2 1 is a non-capacity control type scroll compressor that has a maximum discharge capacity 1/2 that of the maximum capacity required by the system to be supplied with high-pressure gas (hereinafter simply referred to as the required maximum capacity). is there. The capacity controller 122 is, for example, a multi-stage capacity control squeal compressor shown in FIG. 5, and has a maximum discharge capacity of 112, which is the required maximum capacity of the system. The capacity controller 122 controls the opening and closing of the bypass valve (see Fig. 5) by opening and closing the first solenoid valve 123 to switch the discharge capacity between 100% and 50%. The set load of the compressor is switched between 100% and 75% by opening and closing the second solenoid valve 124, and the compressor is opened and closed by opening and closing the third solenoid valve 125. The set load is switched between 100% and 65%. It should be noted that the capacity controller 122 has a nozzle, for example, outside the spiral of the first scroll. A liquid injection pipe 126 is provided, and a liquid line 127 from the system side is connected.

The multi-stage displacement scroll compressor having the above configuration operates as follows. First, the standard machine 1 2 1 is set to the unload state. In this state, the capacity controller 122 sets the substantial load to 24% as described above. Then, the discharge capacity from the standard machine 122 to the system is 0% of the required maximum capacity (= 50% X 0%), and the discharge capacity from the capacity control machine 122 to the system is 1% of the required maximum capacity. 2 ° /. (= 50% X 24%), the actual discharge capacity to the system is 12% of the required maximum capacity (= standard equipment 0% + capacity control equipment 12%). Similarly, if the actual load of the capacity controller 122 is set to 50%, the discharge capacity to the system will be 25% of the required maximum capacity (= 50% X 50%). The capacity is 25% of the required maximum capacity. When the real load of the capacity controller 122 is set to 75%, the actual discharge capacity to the system is 37.5% of the required maximum capacity. Also, when the real load of the capacity controller 122 is set to 100%, the real discharge capacity to the system becomes 50% of the required maximum capacity.

Next, the standard machine 122 is brought into a full load (100%) state. In this state, the capacity controller 122 sets the substantial load to 24% as described above. Then, the discharge capacity from the standard machine 122 to the system is 50% of the required maximum capacity (= 50% x 100%), and the discharge capacity from the capacity controller 122 to the system is the required maximum capacity. The actual discharge capacity to the system is 62% of the required maximum capacity (= 50% for standard equipment + 12% for capacity control equipment). Similarly, if the real load of the capacity controller 122 is set to 50%, the real discharge capacity to the system will be 75% of the required maximum capacity. Also, if the real load of the capacity controller 122 is set to 75%, the real discharge capacity to the system will be 87.5% of the required maximum capacity. Further, when the real load of the capacity controller 122 is set to 100%, the real discharge capacity to the system becomes 100% of the required maximum capacity.

In this case, in the displacement controller 122, since the high-temperature and high-pressure gas in the discharge dome is returned to the suction side, the compression unit including the first scroll and the second scroll, The temperature of the motor driving the scroll You. Therefore, in the present embodiment, a liquid injection pipe 126 is provided in the capacity controller 122 to inject a liquid refrigerant from the system side. Therefore, the injected liquid refrigerant flows down from the compression section composed of the first scroll and the second scroll to the motor side that rotationally drives the second scroll, and the compression section and the motor are cooled. In this way, the discharge gas and motor temperature are reduced, and the operable range is expanded. The mounting of the liquid injection pipe to the capacity controller can be applied to the multi-stage capacity controller scroll compressor in the first and second embodiments.

As described above, in the present embodiment, the standard machine 1 2 1 having the maximum discharge capacity of 1/2 of the maximum capacity required by the system and the maximum discharge capacity of 1/2 of the maximum capacity required by the system are used. A twin-stage multi-stage capacity control scroll compressor is composed of the capacity controller 1 2 and Therefore, at the same time as switching the standard machine 12 1 between the unload state and the full load state, the effective load of the capacity controller 122 is switched to 24%, 50%, 75%, and 100%. The actual displacement of the twin multi-stage scroll compressors to the system is 12%, 25%, 37.5%, 50%, 62%, 7% of the required maximum capacity of the system. It is possible to switch to 8 levels of 5%, 87.5% and 100%. Also, if the real load of the capacity controller 122 is switched to a maximum of eight levels, the real discharge capacity from the twin multi-step capacity control scroll compressor to the system can be switched to 16 levels. In the above description, for the sake of simplicity, the maximum discharge capacity of the standard unit 122 and the capacity control unit 122 is assumed to be 1/2 of the required maximum capacity of the system, but is not limited to this. Instead, it should be set appropriately according to the required actual discharge capacity.

Incidentally, the above embodiments (hereinafter, representative first embodiment) joint pipe 3 6 connected to the operating chamber 3 1 of the Ebaipasu valve ₂ 7 in has its distal end to the lid member (2) 9 It is installed by inserting it into the drilled hole and sealed with O-ring 52. However, such a mounting structure is vulnerable to vibration of the joint pipe 36, and leakage may occur depending on use conditions. There is also the problem of heat resistance. Therefore, in the fourth embodiment, a mounting structure as shown in FIGS. 7A and 7B is adopted.

In Fig. 7A, a male thread 1 32 is provided at the taper at the end of the joint pipe 1 31. On the other hand, a female screw 134 is provided in the tapered hole of the lid member 133. Then, the tapered portion at the tip of the joint pipe 13 1 is screwed into the tapered hole of the lid member 133, and the joint pipe 13 1 is attached to the lid member 133. By sealing with a taper screw in this way, a mounting structure that is resistant to vibration of the joint pipe 13 1 and has high leakage resistance and heat resistance can be obtained. In FIG. 7B, the joint pipe main body 135 and the pipe body 136 are separated, and the pipe body 136 is formed integrally with the lid member 137. Then, the tip of the tube 136 is made to protrude through the hole 13 of the casing 138 and is welded at the hole 13. Then, the tapered hole of the joint pipe main body 135 is screwed into the taper portion at the tip of the pipe 136. Thus, the tube 1 36 configured integrally with the lid member 1 37, by coupling with the joint tube body 1 ₃ 5 and tapered thread, the tube 1 36 strong leak resistance and heat resistance to vibration of The height and mounting structure can be obtained.

In each of the above embodiments, as shown in FIG. 9, the end of the spiral of the first scroll 21, 61, 81, 101 is more than the end of the spiral of the second scroll 22, 62, 82, 102. The outermost contact point E of the second scroll 22, 62, 82, 102 with respect to the first scroll 21, 61, 8 1, 10 1 is extended by π (rad) by the extension angle, A so-called asymmetric spiral scroll compressor is described as an example. However, the present invention is not limited to this, and may be applied to a so-called symmetric scroll type scroll compressor in which the spiral ends of a pair of symmetric scrolls are shifted from each other by π (rad) at the expansion angle. Applicable. However, in the case of this symmetric spiral scroll compressor, the first fluid working chamber A formed by the inner surface of the first scroll and the outer surface of the second scroll, the outer surface of the first scroll, and the inner surface of the second scroll Since the second fluid working chamber B is formed not in the same position but in opposition to each other, the first bypass valve for changing the displacement of the compressor is provided in the first fluid working chamber A. And the second fluid working chamber B need to be provided at positions facing each other.

Claims

The scope of the claims

1. a first bypass passage (26) formed at a predetermined position in the compression chamber and sucking the compressed gas in the fluid working chamber and returning it to the port (23);

First opening / closing means (27) for opening / closing the first bypass passage (26);

A second bypass passage (45) communicating the discharge side and the suction side,

A multi-stage displacement control mouth opening and closing the second bypass passage (45) and a second opening / closing means (40) for releasing a predetermined amount of high-pressure gas on the discharge side to the suction side when the second bypass passage (45) is opened. Compressor.

2. The multi-stage capacity controlled squealer compressor according to claim 1,

In the first scroll (21) and the second scroll (22) forming the compression chamber, the end of the spiral of one scroll is longer than the end of the spiral of the other scroll by an extension angle of 180 degrees. A multi-stage displacement control scroll compressor characterized by exhibiting an asymmetric spiral shape.

3. The multi-stage capacity control scroll compressor according to claim 1,

The multistage displacement control scroll compressor, wherein the second bypass passage (93) is provided outside the compressor body.

4. The multi-stage capacity control scroll compressor according to claim 1 or claim 3,

A multi-stage displacement control scroll compressor comprising a plurality of the second bypass passages (1 1 3, 1 1 4) and a plurality of second opening / closing means (1 1, 1, 1 1 2).

5. The multi-stage capacity control squeal compressor according to claim 3,

The multistage displacement control scroll compressor, wherein the second opening / closing means for opening / closing the second bypass passage (93) is an electric valve that can be controlled to an arbitrary opening.

6. The multi-stage displacement scroll compressor according to claim 1,

The second opening / closing means (40) is operated by a differential pressure between a pilot pressure and a pressure on the suction side or a pressure on the discharge side. Machine.

7. The multi-stage capacity-controlled scroll compressor according to claim 1, A multi-stage volume control scroll compressor comprising a liquid injection pipe (126) for cooling a low-pressure chamber communicating with the suction port (23).

8. The multi-stage displacement scroll compressor according to claim 1,

The first opening / closing means (63) and the second opening / closing means (69) are operated by pilot pressure.

The port port of the first opening / closing means (63) and the port port of the second opening / closing means (69) are connected to each other via one joint fitting (74) provided at the upper center of the compressor body. A multi-stage capacity-controlled scroll compressor connected to the pilot lines (67, 72).

9. A multi-stage capacity-controlled scroll compressor (122) according to claim 1,

Equipped with a fixed scroll displacement standard scroll compressor (121)

A multi-stage capacity-controlled scroll compressor, wherein the multi-stage capacity-controlled scroll compressor (1 22) and the standard squeal compressor (1 21) are connected in parallel.

10. The multi-stage displacement scroll compressor according to claim 1,

The first opening / closing means is operated at a pipe pressure,

The pilot port of the first opening / closing means and a fitting (131,135) for connecting a pilot line to the pilot port are connected by screws. Compressor.