JP2004211567A - Displacement changing mechanism of scroll compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a displacement changing mechanism of a scroll compressor, which can ensure sealing of bypass passages. <P>SOLUTION: The bypass passages 48, 61e, 61f connect compression chambers 67 in the middle of being reduced in their volume and an intake chamber 69. A valve chamber 45 is connected with valve holes 61e that form parts of the bypass passages 48, 61e, 61f, and a valve seat surface 48a is formed on the periphery of an opening of each valve hole 61e. A valve plate 46 is arranged in the valve chamber 45 to be able to engage with and disengage from the valve seat surfaces 48a. The valve plate 46 can be shiftingly changed by driving of drive means 57, 58, 71-73 between an open position where a front end 46a is separated from the valve seat surfaces 48a to open the valve holes 61e and a close position where the front end 46a is seated on the valve seat surfaces 48a to close the valve holes 61e. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to, for example, a scroll compressor used for a vehicle air conditioner, and more particularly to a displacement variable mechanism for changing a discharge capacity of the scroll compressor.
[0002]
[Prior art]
As this type of variable capacity mechanism, there is a mechanism capable of changing the discharge capacity of a scroll compressor by opening and closing a bypass passage connecting a compression chamber and a suction pressure region in the middle of a volume reduction with a spool valve (for example, a scroll compressor). See Patent Document 1.).
[0003]
The spool valve has a spool slidably housed in a cylinder. The spool has a valve portion having an outer diameter substantially equal to the inner diameter of the cylinder to open and close the bypass passage, and a rod portion having an outer diameter smaller than the inner diameter of the cylinder and constituting a part of the bypass passage. I have.
[0004]
[Patent Document 1]
JP 2001-32787 A (pages 6, 7; FIG. 2)
[0005]
[Problems to be solved by the invention]
However, the spool valve of the variable capacity mechanism has a structure in which a port opened on the inner peripheral surface of the cylinder (inner surface of the cylinder) is opened and closed by a valve portion (cylinder) of the spool, so that it is difficult to arrange a seal member on the valve portion. It is. Therefore, leakage of refrigerant gas from the spool valve is prevented by contact between the valve portion of the spool and the inner peripheral surface of the cylinder.
[0006]
If the clearance between the valve portion of the spool and the inner peripheral surface of the cylinder is set small, it is possible to effectively suppress the leakage of the refrigerant gas from the bypass passage. However, when the clearance between the valve portion of the spool and the inner peripheral surface of the cylinder is small, the sliding resistance between the spool and the cylinder increases, and the response of the variable capacity is deteriorated or the actuator for driving the spool is reduced. However, problems such as an increase in size occur.
[0007]
Therefore, conventionally, the clearance between the valve portion of the spool and the inner peripheral surface of the cylinder is set to be large, including suppressing an increase in machining cost due to the high precision setting of the clearance. Therefore, for example, even if the scroll passage is closed and the scroll compressor is operated at the maximum discharge capacity, the desired maximum discharge capacity cannot be realized due to leakage of the refrigerant gas from the spool valve (bypass path). A problem of performance degradation has occurred.
[0008]
An object of the present invention is to provide a variable capacity mechanism of a scroll compressor that can reliably seal a bypass passage.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, a capacity variable mechanism according to the first aspect of the present invention includes a bypass passage, a valve hole, a valve chamber, a valve plate, and a driving type means. The bypass passage connects the compression chamber of the scroll compressor, which is in the process of reducing the volume, to the suction pressure region. The valve hole forms a part of the bypass passage. A valve hole is connected to the valve chamber, and a valve seat surface is formed around the opening of the valve hole in the valve chamber. The valve plate is disposed in the valve chamber so as to be able to approach and separate from the valve seat surface, the end surface is separated from the valve seat surface to open the valve hole, and the end surface is seated on the valve seat surface to open the valve hole. The movement can be switched to a closing position to close. The driving means drives the valve plate.
[0010]
Therefore, for example, if the valve plate is switched to the closing position by the driving means to close the valve hole (bypass passage), the compression chamber in the middle of reducing the volume is not communicated with the suction pressure region, and the compression chamber is The compression work can be performed almost completely from the beginning to the end of the volume reduction. Therefore, the discharge capacity of the scroll compressor is maximized.
[0011]
When the valve plate is switched to the open position by the driving means to open the valve hole (bypass passage), the compression chamber in the middle of volume reduction is communicated with the suction pressure area, and the compression chamber completely performs the compression work. You will not be able to do it. Therefore, the discharge capacity of the scroll compressor is reduced from the maximum.
[0012]
In the present invention, the opening and closing of the bypass passage, that is, the change of the discharge capacity of the scroll compressor is performed by the contact and separation of the end surface (plate surface) of the valve plate with respect to the valve seat surface. Therefore, the sealing of the bypass passage in a state where the valve plate is arranged at the closing position is performed by the end surface of the valve plate sitting on the valve seat surface. Therefore, as compared with a configuration in which a port opened on the inner peripheral surface of the cylinder (inner surface of the cylinder) is opened and closed by a valve portion (cylinder) of a spool as in Patent Document 1, for example, the mobility of the valve plate is not hindered. It becomes easy to enhance the adhesion between the end surface of the valve plate and the valve seat surface. As a result, it is possible to reliably seal the bypass passage in a state where the valve plate is disposed at the closed position, and it is possible to suppress a decrease in the performance of the scroll compressor due to gas leakage from the bypass passage.
[0013]
According to a second aspect of the present invention, in the first aspect, when the valve plate is located at the open position, the compression chamber and the suction pressure region are always in communication until the compression chamber in the middle of volume reduction is reduced to a predetermined volume. The bypass passage is configured such that That is, the compression chamber hardly performs the compression work from the start of the volume reduction to the reduction to the predetermined volume. Therefore, for example, after the compression chamber is caused to perform a compression work to a predetermined volume, the gas is recompressed, that is, wasted compression, as compared with a variable capacity mechanism that realizes a small discharge capacity by connecting the compression chamber to the suction pressure region. Power loss of the scroll compressor caused by work can be suppressed.
[0014]
According to a third aspect of the present invention, in the second aspect, the valve hole forms a portion of the bypass passage on the compression chamber side of the valve chamber. A plurality of valve holes are provided, and the plurality of valve holes are respectively connected to the compression chamber and the valve chamber at different positions. The valve plate simultaneously opens and closes a plurality of valve holes at different positions on the end face. Therefore, the above-mentioned constant communication between the compression chamber and the suction pressure region in the middle of volume reduction can be easily achieved without complicating the configuration. That is, for example, when opening and closing a plurality of valve holes with a spool valve as in Patent Literature 1, it is necessary to use a plurality of spool valves due to the scattering of the plurality of valve holes. However, according to the valve plate adopted by the present invention, it is possible to appropriately cope with the problem by a simple method using only a size corresponding to the dispersion of the plurality of valve holes.
[0015]
According to a fourth aspect of the present invention, in the third aspect, the valve plate simultaneously opens and closes a second valve hole that constitutes a portion of the bypass passage on the suction pressure region side of the valve chamber. Therefore, in a state where the valve plate is located at the closing position, both valve holes are closed at the same time, so that the sealing of the bypass passage can be more reliably performed.
[0016]
According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the fixed scroll member has a spiral wall provided on a substrate. The valve chamber is arranged on the back side of the substrate of the fixed scroll member. The valve seat surface of the valve chamber is provided by a substrate of the fixed scroll member. The valve plate is arranged along the substrate of the fixed scroll member. That is, the valve plate is arranged such that the end surface is parallel to the back surface of the substrate.
[0017]
With such a valve plate arrangement, it is possible to suppress an increase in the size of the scroll compressor in the axial direction due to the provision of the variable capacity mechanism. In other words, by adopting the valve plate as the opening / closing means of the bypass passage, a compact design in which the opening / closing means is arranged along the substrate of the fixed scroll member is also free.
[0018]
According to a sixth aspect of the present invention, in the fifth aspect, the valve plate has an annular shape or a partially annular shape. A discharge passage for guiding compressed gas from the compression chamber to the discharge chamber is provided at the center (through hole) of the valve plate. As described above, by disposing the discharge passage using the center portion of the valve plate that is not used for opening and closing the valve hole, the compression chamber and the discharge chamber on the center side can be connected with the shortest distance. Therefore, the flow of gas from the compression chamber on the center side to the discharge chamber can be made smooth, and the deterioration of the efficiency of the scroll compressor due to the pressure loss due to the pipe resistance between the compression chamber and the discharge chamber is suppressed. can do.
[0019]
A seventh aspect of the present invention is the sealing member according to any one of the first to sixth aspects, wherein the end face of the valve plate or the valve seat face of the valve chamber seals the bypass passage in a state where the valve plate is disposed in the closed position. Are arranged. Therefore, it is possible to more reliably seal the bypass passage in a state where the valve plate is disposed at the closed position. In other words, by adopting a configuration in which a valve plate is used as the opening / closing means of the bypass passage and the valve plate is brought into contact with or separated from the valve seat surface, a seal that improves the sealing performance of the bypass passage at the closed position of the valve plate. The members can be arranged without impairing the mobility of the valve plate.
[0020]
The invention of claim 8 refers to a preferred embodiment of the driving means in any one of claims 1 to 7. That is, the valve chamber is divided into a communication chamber located on the valve hole side and constituting a part of the bypass passage and a back pressure chamber on the opposite side to the valve hole, depending on the arrangement of the valve plate. The driving means adjusts the opening degree of the control passage based on a command from the outside, a biasing spring for biasing the valve plate toward the open position, a control passage connecting the back pressure chamber and the discharge pressure region. And a control valve.
[0021]
Therefore, when the control valve opens the control passage, the high-pressure gas in the discharge pressure region is introduced into the back pressure chamber through the control passage, and the pressure in the back pressure chamber increases. Therefore, the valve plate moves to the closing position against the force based on the spring force of the urging spring and the pressure in the communication chamber, and the bypass passage is closed. Therefore, the discharge capacity of the compression mechanism becomes maximum. Conversely, when the control passage closes the control passage, the high-pressure gas in the discharge pressure region is not introduced into the back pressure chamber, and the pressure in the back pressure chamber decreases. Therefore, the valve plate moves to the open position by the force based on the spring force of the urging spring and the pressure in the communication chamber, and the bypass passage is opened. Therefore, the displacement of the compressor is reduced from the maximum.
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment in which the present invention is embodied in a hybrid compressor (combined drive type compressor) as a scroll compressor will be described. Note that the left side of FIG. 1 is the front of the hybrid compressor C, and the right side is the rear.
[0023]
First, an outline of a hybrid compressor (hereinafter simply referred to as a compressor) C will be described.
As shown in FIG. 1, a compressor C for compressing a refrigerant constituting a refrigeration cycle of a vehicle air conditioner includes a housing 11 in which a compression mechanism 12 and an electric motor 21 are housed, and a power transmission mechanism on an outer wall of the housing 11. 22 are provided. The compression mechanism 12 is of a scroll type and has a configuration in which the discharge capacity can be changed. The power transmission mechanism 22 receives power from an engine (internal combustion engine) E, which is a driving source of the vehicle.
[0024]
The compressor C is used by switching between the power from the engine E via the power transmission mechanism 22 and the power from the electric motor 21. As described above, since the compressor C includes the electric motor 21, air conditioning (cooling) can be performed even when the engine E is stopped. Therefore, it can be said that the vehicle air conditioner of the present embodiment is a mode particularly suitable for an idling stop vehicle and a hybrid vehicle.
[0025]
Next, details of the compressor C will be described.
As shown in FIG. 1, the housing 11 is formed by joining and fixing a lid 11b to the rear end of a cylindrical container 11a having a bottom on the front side. A rotation shaft 13 is rotatably arranged in the housing 11. An insertion hole 34 is formed at the center of the bottom of the housing 11a of the housing 11 so as to pass therethrough. The front end side of the rotating shaft 13 is inserted through the insertion hole 34, and the front end side of the rotating shaft 13 is rotatably supported by the housing 11 through the bearing 35 in the insertion hole 34. At the front end side of the rotating shaft 13 in the housing 11, a lip seal 37 that seals the rotating shaft 13 is provided.
[0026]
On the rear end side of the container 11a in the housing 11, a shaft support member 31 having a through hole 31a formed in the center thereof is fixed. The rear end side of the rotating shaft 13 is inserted through an insertion hole 31a of the shaft support member 31, and is rotatably supported by the shaft support member 31 through a bearing 32 in the insertion hole 31a.
[0027]
The power transmission mechanism 22 includes a pulley 17 and an electromagnetic clutch 18. The pulley 17 is rotatably supported outside the housing 11, and transmits power from the engine E to the rotating shaft 13. The electromagnetic clutch 18 permits power transmission between the pulley 17 and the rotary shaft 13 when turned on (energized), and shuts off this power transmission when turned off (de-energized).
[0028]
A stator 15 is provided on the inner peripheral surface of the container 11a in the front region in the housing 11. The rotor 14 is fixed to the compressor shaft 19 in the housing 11 so as to be located on the inner peripheral side of the stator 15. The electric motor 21 is constituted by the stator 15 and the rotor 14. The electric motor 21 integrally rotates the rotor 14 and the rotating shaft 13 by supplying power to the stator 15.
[0029]
A fixed scroll member 41 is housed and fixed in the housing 11 at the open end of the container 11a. The fixed scroll member 41 has a cylindrical outer peripheral wall 62 erected on the outer peripheral side of a disk-shaped substrate 61, and a spiral wall 63 erected inside the outer peripheral wall 62 on the substrate 61. The fixed scroll member 41 is joined to the rear surface of the shaft support member 31 with the distal end surface of the outer peripheral wall 62.
[0030]
An eccentric shaft 43 is provided at a rear end of the rotating shaft 13 at a position eccentric with respect to the axis L of the rotating shaft 13. A bush 51 is externally fitted and fixed to the eccentric shaft 43. A movable scroll member 42 is supported by the bush 51 so as to be relatively rotatable via a bearing 52 so as to face the fixed scroll member 41. The movable scroll member 42 is formed by arranging a spiral wall 66 on a substrate 65 having a disk shape toward the fixed scroll member 41.
[0031]
The fixed scroll member 41 and the movable scroll member 42 are meshed with each other via spiral walls 63, 66, and the distal end surfaces of the spiral walls 63, 66 are connected to the substrates 61, 42 of the other scroll members 41, 42. 65. Accordingly, the substrate 61 and the spiral wall 63 of the fixed scroll member 41 and the substrate 65 and the spiral wall 66 of the movable scroll member 42 define a compression chamber 67.
[0032]
A rotation preventing mechanism 68 is provided between the substrate 65 of the movable scroll member 42 and the shaft support member 31 facing the substrate 65. The rotation preventing mechanism 68 includes a plurality of annular holes 68a provided on the back surface of the substrate 65 in the movable scroll member 42, and a plurality of pins 68b projecting from the rear end surface of the shaft support member 31 and loosely fitted in the annular holes 68a. It consists of
[0033]
A suction chamber 69 is formed between the outer peripheral wall 62 of the fixed scroll member 41 and the outermost peripheral portion of the spiral wall 66 of the movable scroll member 42 as a suction pressure area. In the container 11 a of the housing 11, a suction port 50 is formed on an outer peripheral surface corresponding to a housing area of the electric motor 21. An external pipe connected to a low-pressure side heat exchanger of an external refrigerant circuit (not shown) is connected to the suction port 50. In the housing 11, a suction passage 39 is formed on the outer peripheral portion of the shaft support member 31, which communicates the housing area of the electric motor 21 with the suction chamber. Therefore, the low-pressure refrigerant gas from the external refrigerant circuit is introduced into the suction chamber 69 via the suction port 50, the housing area of the electric motor 21 in the housing 11, and the suction passage 39. Since the relatively low-temperature suction refrigerant gas passes near the electric motor 21, the thermal environment of the electric motor 21 is improved.
[0034]
In the fixed scroll member 41, a first housing recess 61b is formed in a part of the rear surface 61a of the substrate 61 in a region from near the center to near the outer peripheral edge. By closing the first housing recess 61b with the lid 11b, a discharge chamber 70 as a discharge pressure region is defined in the housing 11 between the fixed scroll member 41 and the lid 11b. An external pipe connected to a high-pressure side heat exchanger of an external refrigerant circuit (not shown) is connected to the discharge chamber 70 via a discharge port 53 formed in the lid 11b of the housing 11.
[0035]
At the center of the substrate 61 in the fixed scroll member 41, a discharge hole 61c as a discharge passage is formed penetrating in the front and back directions, and the compression chamber 67 and the discharge chamber 70 on the center side are connected through the discharge hole 61c. I have. In the discharge chamber 70, the fixed scroll member 41 is provided with a discharge valve 55 composed of a reed valve for opening and closing the discharge hole 61c. The opening of the discharge valve 55 is regulated by a retainer 56 fixed to the fixed scroll member 41 in the discharge chamber 70.
[0036]
When the rotation shaft 13 is driven to rotate by the engine E or the electric motor 21, in the compression mechanism 12, the movable scroll member 42 is moved to the center of the fixed scroll member 41 (the axis L) via the eccentric shaft 43. It is turned (revolved) around. At this time, the orbiting scroll member 42 is prevented from rotating by the rotation preventing mechanism 68, and only the orbital movement is allowed.
[0037]
The orbiting of the movable scroll member 42 with respect to the fixed scroll member 41 causes the compression chamber 67 to move from the outer peripheral side of the spiral walls 63 and 66 of the scroll members 41 and 42 to the center side while reducing the volume, thereby providing a suction chamber. The low-pressure refrigerant gas taken into the compression chamber 67 on the outer peripheral side from 69 is compressed. The compressed high-pressure refrigerant gas is discharged from the central compression chamber 67 to the discharge chamber 70 via the discharge hole 61c and the discharge valve 55.
[0038]
Next, the variable capacity mechanism of the compressor C will be described.
As shown in FIGS. 2 and 3A, a second housing recess 61 d is formed on the back surface 61 a of the substrate 61 in the fixed scroll member 41. The second housing recess 61d is formed in a horseshoe shape (an annular portion partially separated) so as to avoid the first housing recess 61b. In the housing 11, the valve chamber 45 is defined by partitioning the opening of the second housing recess 61d by the end surface of the lid 11b. A valve plate 46 is displaceably housed in the valve chamber 45.
[0039]
The valve plate 46 has a flat plate shape and a horseshoe shape such that the valve plate 46 fits into the second housing recess 61d. That is, the discharge hole 61c is provided at the center (through hole) of the valve plate 46, and it can be said that the valve plate 46 has a shape that avoids the discharge hole 61c. An O-ring 47 is attached to the outer peripheral surface of the valve plate 46, and the valve plate 46 can slide on the inner peripheral surface of the valve chamber 45 through the O-ring 47.
[0040]
The inside of the valve chamber 45 is divided into a communication chamber 48 on the fixed scroll member 41 side and a back pressure chamber 49 on the lid 11b side by the housing arrangement of the valve plate 46. The communication chamber 48 and the back pressure chamber 49 are shut off by the O-ring 47 of the valve plate 46. In the communication chamber 48, a horseshoe-shaped valve seat surface 48 a is formed on the substrate 61 so as to face a horseshoe-shaped front plate surface (hereinafter referred to as a front end surface) 46 a of the valve plate 46. I have. The valve plate 46 is arranged along the substrate 61 such that the front end surface 46a is parallel to the rear surface 61a of the substrate 61.
[0041]
A first valve hole 61e as a valve hole is formed in the substrate 61 of the fixed scroll member 41 so as to penetrate in the front and back directions. One end of the first valve hole 61 e is opened to the compression chamber 67 in the middle of decreasing the volume, and the other end is opened to the communication chamber 48 on the valve seat surface 48 a of the substrate 61. A plurality of first valve holes 61e are provided. The plurality of first valve holes 61e are used until the compression chamber 67 of the maximum volume located at the outermost peripheral portion, which is the start position of the volume reduction, is reduced (moved) to a predetermined volume (for example, 20% of the maximum volume). Connections to the compression chamber 67 and the communication chamber 48 are made at different positions so that the first valve holes 61e are alternately connected to the compression chamber 67 in the middle of the volume reduction.
[0042]
A second valve hole 61f as a second valve hole is formed in the substrate 61 of the fixed scroll member 41 so as to penetrate in the front and back directions. The communication chamber 48 and the suction chamber 69 are connected via the second valve hole 61f. The second valve hole 61f is open to the communication chamber 48 at a position different from the first valve hole 61e on the valve seat surface 48a of the substrate 61. In the present embodiment, the first valve hole 61e, the second valve hole 61f, and the communication chamber 48 form a bypass passage that connects the compression chamber 67 and the suction chamber 69 that are in the process of reducing the volume.
[0043]
The valve plate 46 is separated from the valve seat surface 48a in the communication chamber 48 to open the first valve hole 61e and the second valve hole 61f, and the first valve hole 61e is seated on the valve seat surface 48a. Then, the movement is switched to the closing position for closing the second valve hole 61f. The front end surface 46a of the valve plate 46 is provided by a rubber coat 46b applied to the valve plate 46. Therefore, at the closing position of the valve plate 46, the elastic deformation of the rubber coat 46b ensures that the first valve hole 61e and the second valve hole 61f are closed by the front end surface 46a.
[0044]
The driving means for driving the valve plate 46 includes an urging spring 57 disposed in the communication chamber 48, a control valve 58 composed of an electromagnetic three-way valve, and a first passage 71 connecting the discharge chamber 70 and the control valve 58. , A second passage 72 connecting the back pressure chamber 49 and the control valve 58, and a third passage 73 connecting the suction chamber 69 and the control valve 58. For easy understanding, the control valve 58 is indicated by a symbol in FIGS. 1, 3A and 3B.
[0045]
A plurality of the urging springs 57 are arranged between the valve seat surface 48a of the substrate 61 and the front end surface 46a of the valve plate 46 so as to avoid the opening of the first valve hole 61e and the opening of the second valve hole 61f. Have been. The valve plate 46 is urged by a spring force of an urging spring 57 in a direction in which the front end surface 46a is separated from the valve seat surface 48a. A first passage 71 is connected to the first port 58a of the control valve 58, a second passage 72 is connected to the second port 58b, and a third passage 73 is connected to the third port 58c.
[0046]
In the present embodiment, the first passage 71, the internal passage of the control valve 58, and the second passage 72 form a control passage connecting the back pressure chamber 49 and the discharge chamber 70. The control valve 58 opens and closes a control passage based on an external command. That is, the control valve 58 switches the connection destination of the second passage 72 between the first passage 71 and the third passage 73 when the solenoid 58d is demagnetized based on an external command. In other words, the control valve 58 switches the connection destination of the back pressure chamber 49 between the suction chamber 69 and the discharge chamber 70 by the excitation and demagnetization of the solenoid 58d.
[0047]
For example, as shown in FIG. 3B, when the solenoid 58d is demagnetized, the first passage 71 and the second passage 72 are connected via the control valve 58. Accordingly, the high-pressure refrigerant gas in the discharge chamber 70 is introduced into the back pressure chamber 49 via the first passage 71, the control valve 58, and the second passage 72. In this state, since the third passage 73 is closed by the control valve 58, the refrigerant gas in the back pressure chamber 49 is not led out to the suction chamber 69. Accordingly, the pressure in the back pressure chamber 49 increases, and the valve plate 46 moves to the closing position against the spring force of the urging spring 57 and the force based on the pressure in the communication chamber 48, and the first valve hole 61e. And the second valve hole 61f is closed.
[0048]
In a state where the first valve hole 61e and the second valve hole 61f are closed, the compression chamber 67 which is in the middle of reducing the volume does not communicate with the suction chamber 69, and the compression chamber 67 almost completely performs the compression work. The discharge capacity of the compression mechanism 12 is maximized. The maximum discharge capacity of the compression mechanism 12 is realized, for example, when the engine E is selected as the drive source of the compression mechanism 12. Therefore, even if the rotation speed of the rotary shaft 13 is low due to the idling state of the engine E, it is possible to secure a large amount of refrigerant discharged per unit time of the compression mechanism 12, that is, to exert a high cooling capacity.
[0049]
Further, as shown in FIG. 3A, when the solenoid 58d is excited, the second passage 72 and the third passage 73 are connected via the control valve 58. Therefore, the refrigerant gas in the back pressure chamber 49 is led to the suction chamber 69 via the second passage 72, the control valve 58, and the third passage 73. In this state, since the first passage 71 is closed by the control valve 58, the high-pressure refrigerant gas in the discharge chamber 70 is not introduced into the back pressure chamber 49. Accordingly, the pressure in the back pressure chamber 49 decreases, and the valve plate 46 moves to the open position by the force based on the spring force of the urging spring 57 and the pressure in the communication chamber 48, and the first valve hole 61e and the second The valve hole 61f is opened.
[0050]
In a state where the first valve hole 61e and the second valve hole 61f are opened, any one of the first valve holes 61e and the communication holes are not changed until the compression chamber 67 in the middle of the volume reduction is reduced to a predetermined volume. Through the chamber 48 and the second valve hole 61f, it is always in communication with the suction chamber 69. Therefore, the compression chamber 67 cannot perform the compression work completely, and the discharge capacity of the compression mechanism 12 is reduced from the maximum. The reduction of the discharge capacity of the compression mechanism 12 from the maximum is realized, for example, when the electric motor 21 is selected as the drive source of the compression mechanism 12. The compression mechanism 12 having a reduced discharge capacity requires less torque to drive it. Therefore, the size of the compressor C can be reduced by reducing the size of the electric motor 21.
[0051]
The present embodiment having the above configuration has the following effects.
(1) The opening and closing of the bypass passages 48, 61e and 61f, that is, the change of the discharge capacity of the compressor C is performed by the contact and separation of the front end surface (plate surface) 46a of the valve plate 46 with respect to the valve seat surface 48a. Therefore, the sealing of the bypass passages 48, 61e and 61f in a state where the valve plate 46 is arranged at the closing position is performed by the front end surface 46a of the valve plate 46 sitting on the valve seat surface 48a. Therefore, the mobility of the valve plate 46 is inhibited as compared with a configuration in which a port opened on the inner peripheral surface of the cylinder (inner surface of the cylinder) is opened and closed by a valve portion (cylinder) of the spool as in Patent Document 1, for example. Therefore, it is easy to enhance the adhesion between the front end surface 46a of the valve plate 46 and the valve seat surface 48a. Therefore, it is possible to reliably seal the bypass passages 48, 61e, and 61f in a state where the valve plate 46 is disposed at the closed position, and the compressor C caused by the leakage of the refrigerant gas from the bypass passages 48, 61e, and 61f. Can be suppressed from deteriorating.
[0052]
(2) The bypass passages 48, 61e, and 61f, when the valve plate 46 is located at the open position, keep the compression chamber 67 and the suction chamber 69 until the compression chamber 67 in the middle of reducing the volume is reduced to a predetermined volume. Are always connected. That is, at the open position of the valve plate 46, the compression chamber 67 hardly performs the compression work until the volume is reduced to the predetermined volume after the volume reduction starts. Therefore, for example, after the compression chamber is caused to perform a compression work to a predetermined volume, the compression chamber is re-compressed, i.e., wasted, as compared with a capacity variable mechanism that communicates the compression chamber with the suction pressure region to realize a small discharge capacity. Power loss of the compressor C due to the compression work can be suppressed.
[0053]
(3) The first valve hole 61e forms an upstream side (compression chamber 67 side) of the bypass passages 48, 61e, and 61f. A plurality of first valve holes 61e are provided, and the plurality of first valve holes 61e are respectively connected to the compression chamber 67 and the communication chamber 48 at different positions. The valve plate 46 simultaneously opens and closes the plurality of first valve holes 61e at different positions on the front end surface 46a. Therefore, the above-described constant communication between the compression chamber 67 and the suction chamber 69 in the middle of the volume reduction can be easily achieved without complicating the configuration.
[0054]
That is, for example, when opening and closing a plurality of valve holes with a spool valve as in Patent Document 1, it is necessary to use a plurality of spool valves due to the scattering of the plurality of valve holes. However, according to the valve plate 46 adopted in the present embodiment, it is possible to suitably cope with a simple configuration using only the size corresponding to the dispersion of the plurality of first valve holes 61e.
[0055]
(4) The valve plate 46 simultaneously opens and closes the second valve hole 61f that constitutes the portion of the bypass passages 48, 61e, 61f on the suction chamber 69 side of the communication chamber 48. Therefore, when the valve plate 46 is located at the closing position, both the valve holes 61e and 61f are closed at the same time, and the sealing of the bypass passages 48, 61e and 61f can be made more reliable.
[0056]
(5) The valve plate 46 is arranged along the substrate 65 of the fixed scroll member 41. With such an arrangement of the valve plate 46, it is possible to suppress an increase in the size of the compressor C in the direction of the axis L due to the provision of the variable capacity mechanism. In other words, by adopting the valve plate 46 (plate-like body) as the opening / closing means of the bypass passages 48, 61e, 61f, a compact design in which the opening / closing means is arranged along the substrate 65 of the fixed scroll member 41 is also free. is there.
[0057]
In particular, the compressor C is a composite drive type in which the power from the engine E via the power transmission mechanism 22 disposed in the housing 11 and the power from the electric motor 21 built in the housing 11 are switched. It is. Accordingly, the compressor C tends to be large in size by including the power transmission mechanism 22 and the electric motor 21. Use of such a compact variable capacity mechanism in the compressor C is particularly effective in suppressing an increase in the size of the compressor C.
[0058]
(6) The valve plate 46 has an annular shape in which a part is separated. A discharge hole 61c for discharging the compressed gas from the compression chamber 67 on the center side to the discharge chamber 70 is provided at the center (through hole) of the valve plate 46. As described above, by disposing the discharge hole 61c using the central portion of the valve plate 46 that is not used for opening and closing the first valve hole 61e and the second valve hole 61f, the central compression chamber 67 and the discharge chamber 70 are disposed. Can be connected with the shortest distance. Therefore, the flow of gas from the compression chamber 67 on the center side to the discharge chamber 70 can be made smooth, and the pressure of the compressor C caused by the pressure loss due to the pipe resistance between the compression chamber 67 and the discharge chamber 70 can be increased. Efficiency deterioration can be suppressed.
[0059]
(7) The front end surface 46a of the valve plate 46 is provided with a rubber coat 46b for sealing the bypass passages 48, 61e and 61f in a state where the valve plate 46 is disposed at the closed position. Therefore, the sealing of the bypass passages 48, 61e, and 61f in a state where the valve plate 46 is disposed at the closed position can be more reliably performed. That is, the valve plate 46 is adopted as the opening / closing means for the bypass passages 48, 61e, and 61f, and the valve plate 46 is configured to come into contact with and separate from the valve seat surface 48a. The rubber coat 46b for improving the sealing performance of the bypass passages 48, 61e, 61f can be arranged without hindering the mobility of the valve plate 46.
[0060]
It should be noted that, for example, the following embodiments can be implemented without departing from the spirit of the present invention. In the above embodiment, only one valve plate 46 is provided. Therefore, the discharge capacity of the compressor C can be changed only in two stages: the maximum discharge capacity when the valve plate 46 is arranged at the closed position, and the minimum discharge capacity when the valve plate 46 is arranged at the open position. Did not. By changing this, the valve plate 46 is divided into a plurality of parts so that the discharge capacity of the compressor C can be changed in three or more stages.
[0061]
That is, for example, the valve plate 46 of the above embodiment is divided into a first and a second two. A first group of valve holes 61e that allows the maximum volume of the compression chamber 67 in the middle of volume reduction to a certain volume (> predetermined volume) to be constantly communicated with the suction chamber 69 is formed by the first divided body of the valve plate 46. Open and close. Further, the first valve hole group 61e, which enables the communication from the certain volume to the predetermined volume of the compression chamber 67 in the middle of the volume reduction to the suction chamber 69, is opened and closed by the second divided body of the valve plate 46. In this case, when both the first and second divided bodies are arranged at the closed position, the discharge capacity of the compressor C becomes maximum, and when both divided bodies are arranged at the open position, the discharge capacity of the compressor C becomes minimum. Become. When the first divided body is located at the open position and the second divided body is located at the closed position, the discharge capacity of the compressor C becomes an intermediate capacity between the maximum and the minimum.
[0062]
In the above-described embodiment, the valve plate 46 has a shape in which a part of an annular shape is separated in order to avoid the base ends of the discharge valve 55 and the retainer 56 (see FIG. 2). However, for example, when a short valve is used for the discharge valve 55 and the retainer 56, and a configuration is adopted in which the base ends of the members 55 and 56 are arranged closer to the center side (the discharge hole 61 c side) of the fixed scroll member 41. The valve plate 46 may be formed in an annular shape so as to surround the discharge valve 55 and the retainer 56. Also in this case, the same effect as (6) of the above embodiment can be obtained.
[0063]
In the above embodiment, when the valve plate 46 is switched to the open position, the bypass passages 48, 61e, and 61f communicate with the compression chamber 67 until the compression chamber 67 in the middle of reducing the volume is reduced to a predetermined volume. The configuration was such that the chamber 69 was always in communication. However, the present invention is not limited to this. The bypass passage may be configured such that after the compression chamber performs compression work to a predetermined volume, the compression chamber communicates with the suction pressure region. By doing so, the number of the first valve holes 61e can be reduced, and the configuration of the bypass passage can be simplified.
[0064]
In the above embodiment, the valve plate 46 is moved between the open position and the closed position by adjusting the pressure of the back pressure chamber 49 by the control valve 58. This is changed so that the valve plate is moved directly between the open position and the closed position by being directly driven by the electromagnetic actuator.
[0065]
The technical idea that can be grasped from the above embodiment will be described below.The scroll compressor is for a vehicle air conditioner, and the scroll compressor is driven by a power from an engine that is a driving source for driving the vehicle and a power from a built-in electric motor. The variable displacement mechanism according to any one of claims 1 to 8, wherein the variable capacity mechanism is a compound drive type that is used by switching between power and power.
[0066]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention of the said structure, it becomes possible to ensure the sealing of a bypass passage, and it can suppress the performance fall of a scroll compressor resulting from the leakage of the refrigerant gas from this bypass passage.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a hybrid compressor.
FIG. 2 is a sectional view taken along line 1-1 of FIG. 1;
3A is an enlarged view of a main part of FIG. 1 and shows a state where a valve plate is arranged at an open position, and FIG. 3B is a view showing a state where the valve plate is arranged at a closed position.
[Explanation of symbols]
41: fixed scroll member, 42: movable scroll member, 45: valve chamber, 46: valve plate, 46a: front end face as end face, 46b: rubber coat as seal member, 48: communication chamber, 48a: valve seat face, 49 ... back pressure chamber, 57 ... urging spring, 58 ... control valve, 61 ... substrate of fixed scroll member, 61a ... back surface, 61c ... discharge hole as discharge passage, 61e ... first valve hole as valve hole, 61f ... A second valve hole as a second valve hole, 63: a spiral wall of the fixed scroll member; 67, a compression chamber; 69, a suction chamber as a suction pressure area; 70, a discharge chamber as a discharge pressure area; 71, a control passage , A second passage forming a control passage, C ... a hybrid compressor as a scroll compressor.

Claims (8)

In a scroll compressor in which a compression chamber partitioned between a movable scroll member and a fixed scroll member is moved toward the center while reducing the volume by turning the movable scroll member with respect to the fixed scroll member to compress the gas,
A bypass passage connecting the compression chamber and the suction pressure area in the middle of volume reduction,
A valve hole constituting a part of the bypass passage;
A valve chamber having the valve hole connected thereto and a valve seat surface formed around the opening of the valve hole;
An open position where the end face is separated from the valve seat surface to open the valve hole, and a closing position where the end surface is seated on the valve seat surface and closes the valve hole in the valve chamber. A valve plate that can be switched between a position and a position;
And a driving means for driving the valve plate. In a state where the valve plate is disposed at the open position, the bypass passage is configured to always communicate the compression chamber and the suction pressure area until the compression chamber in the middle of volume reduction is reduced to a predetermined volume. The variable capacity mechanism according to claim 1. The valve hole constitutes a portion of the bypass passage on the compression chamber side with the valve chamber as a boundary. The valve hole is provided with a plurality of the valve holes, and the plurality of valve holes are located at different positions from each other. 3. The variable displacement mechanism according to claim 2, wherein the valve plate is configured to simultaneously open and close a plurality of valve holes at different positions on an end face. 4. 4. The variable displacement mechanism according to claim 3, wherein the valve plate simultaneously opens and closes a second valve hole that constitutes a portion of the bypass passage on the suction pressure region side of the valve chamber. The fixed scroll member has a spiral wall provided upright on a substrate, the valve chamber is disposed on the back side of the fixed scroll member substrate, and the valve seat surface of the valve chamber is provided by the fixed scroll member substrate. The capacity variable mechanism according to any one of claims 1 to 4, wherein the valve plate is arranged along a substrate of the fixed scroll member. The valve plate has an annular shape or an annular shape in which a part thereof is separated from each other, and a discharge passage for leading compressed gas from the compression chamber to the discharge chamber is provided at a central portion of the valve plate. The variable capacity mechanism according to claim 5, wherein The sealing member which seals a bypass passage in a state where a valve plate is arranged in a closing position is arranged in an end face of the above-mentioned valve plate, or a valve seat surface of a valve room. Variable capacity mechanism. According to the arrangement of the valve plate, the valve chamber is divided into a communication chamber located on the valve hole side and constituting a part of the bypass passage, and a back pressure chamber on the opposite side to the valve hole, and the driving means is A biasing spring for biasing the valve plate toward the open position, a control passage connecting the back pressure chamber and the discharge pressure region, and a control valve for adjusting an opening degree of the control passage based on an external command. The capacity variable mechanism according to any one of claims 1 to 7, comprising:

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