JP2010025202A - Check valve and compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enlarge a passage cross section area of a check valve, regarding the check valve and a compressor with the check valve. <P>SOLUTION: A circular valve plate 31 is integrally formed in a cylinder of a case 30, and a circular supporting plate 32 is fixed and attached on an end face of the case 30. A first valve element 33 and a second valve element 34 are housed in the cylinder of the case 30 between the supporting plate 32 and the valve plate 31 so as to be movable along the cylinder direction of the case 30. The second valve element 34 is energized to the valve plate 31 by a spring. A pair of sector-shaped valve holes 311 and 312 is formed on the valve plate 31. Three sector-shaped communication holes 321 are formed on the supporting plate 32. A pair of sector-shaped first windows 331 and 332 is formed on the first valve element 33, and a pair of sector-shaped second windows 341 and 342 is formed on the second valve element 34. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a check valve and a compressor using the check valve.

Increasing the cross-sectional area of the check valve that prevents the backflow of fluid is important for reducing the passage resistance and smoothly transferring the fluid. The check valve disclosed in Patent Document 1 is a moving valve having a fixed valve body having a plurality of flow holes, a plurality of protrusions that fit into the flow holes and close the flow holes, and a plurality of flow holes. With body. When the fluid flows in the positive flow direction, the moving valve body is separated from the fixed valve body and the projection is separated from the position where the fixed valve body closes the flow hole, and the fluid passes through the fixed valve body flow hole and the movement valve body flow hole. pass. When the fluid tries to flow in the reverse flow direction, the moving valve body comes into contact with the fixed valve body, the protrusion closes the flow hole of the fixed valve body, and the fluid does not pass through the flow hole of the fixed valve body. That is, backflow is prevented.
Japanese Patent Laid-Open No. 9-133234

  In a check valve having a configuration in which a flow hole is provided in the moving valve body, the passage cross-sectional area of the flow hole can be close to half of the pressure receiving area of the valve body, but more than this, the cross-sectional area of the flow hole, that is, the reverse The passage sectional area of the stop valve cannot be increased.

  An object of the present invention is to increase the passage cross-sectional area of a check valve.

  The first to eighth aspects of the invention are directed to a check valve for preventing a back flow of fluid. In the first aspect of the invention, a valve plate and a plurality of valve bodies disposed downstream of the valve plate are provided. One valve body of the plurality of valve bodies can be contacted and separated from the valve plate, and adjacent valve bodies of the plurality of valve bodies can be contacted and separated from each other, the valve plate Has a valve hole, each of the plurality of valve bodies has a window, and the valve body that can contact and separate from the valve plate has a shielding portion that shields a part of the valve hole, The plate has a shielding portion that shields a part of the window of the valve body that can contact and separate from the valve plate, and one of the adjacent valve bodies is the other of the adjacent valve bodies. A shielding part that shields a part of the window; the other of the adjacent valve bodies has a shielding part that shields a part of the one window; and the valve hole, the one window, and the other window The cross-sectional area of each passage is more than half of the pressure receiving area of the valve plate, and in the state where the valve body that can contact and separate from the valve plate and the valve plate are in contact, and the adjacent valve body is in contact, The passage cross-sectional area in the entire stop valve becomes zero.

When there are a plurality of valve bodies, the cross-sectional area of the valve holes and the window of each valve body can be larger than half the pressure receiving area of the valve body that receives pressure in the positive flow direction of the fluid.
In a preferred example, the plurality of valve bodies are two of a first valve body that contacts and separates from the valve plate and a second valve body that contacts and separates from the first valve body, and the first valve body Has a first window at a position away from the first shielding part that shields a part of the valve hole, and the second valve body is detached from the second shielding part that shields a part of the first window. A second window at a different position.

The configuration in which the number of valve bodies is two is a simple configuration for increasing the passage cross-sectional area of the valve hole and the window of each valve body.
In a preferred example, there is a first stopper that restricts the first valve body to a first maximum separated position farthest from a contact position of the first valve body in contact with the valve plate, and the first maximum separated position. A second stopper for regulating the second valve body is provided at a second maximum separated position farthest from the first valve body.

When the fluid is flowing forward, the first stopper and the second stopper regulate the first valve body and the second valve body at positions separated from each other, and the first valve body and the second valve body are in contact with each other. There is no.
In a preferred example, the valve plate, the first valve body, and the second valve body are formed in a circular shape, and the valve hole, the first window, and the second window are the valve plate, The first valve body and the second valve body are formed so as to be shifted to positions that are rotationally symmetric about the central axis passing through the center of each circle. When the plurality of valve bodies are the first valve body and the second valve body, the valve hole, the first window, and the second window are rotated by 120 ° about the central axis. It is desirable to shift to a symmetrical position.

When there are two valve bodies, the cross-sectional area of the valve hole and the window of each valve body can be close to 2/3 times the pressure receiving area of the valve body.
In a preferred example, there is provided guide means for guiding the first valve body and the second valve body so as to be movable and non-rotatable in the direction of contact and separation between the first valve body and the second valve body. It has been.

Since the valve body does not rotate, the first window does not overlap the valve hole and the second window does not overlap the first window when the first valve body is in contact with the valve plate.
In a preferred example, a spring is provided to urge the second valve body toward a position in contact with the first valve body and to urge the first valve body toward a position in contact with the valve plate. Yes.

When the fluid tries to flow backward, the spring disposes the second valve body at a position in contact with the first valve body, and the first valve body is disposed at a position in contact with the valve plate, thereby preventing backflow.
In a preferred example, when there are n (an integer greater than or equal to 3) of the valve bodies, the valve holes and the windows of the n valve bodies are centers that pass through the circle centers of the valve plate and the valve bodies. The axis is shifted to a position that is rotationally symmetric at 360 ° / (n + 1) around the axis.

When there are n (3 or more) valve bodies, the passage cross-sectional area of the valve hole and each valve body window can be close to n / (n + 1) times the pressure receiving area of the valve body.
The invention of claim 9 is directed to a compressor that sucks refrigerant from an external refrigerant circuit into a suction pressure region in a housing and discharges the refrigerant from a discharge pressure region in the housing to the external refrigerant circuit. A suction passage extending from the circuit through the housing to the suction pressure region is provided, and the check valve according to any one of claims 1 to 8 prevents a reverse flow of the refrigerant in the suction passage. It is provided in the suction passage to prevent it.

  The refrigerant in the suction pressure region is prevented from flowing back to the external refrigerant circuit, and the evaporator on the external refrigerant circuit is prevented from being heated.

  The present invention has an excellent effect that the cross-sectional area of the check valve can be increased.

Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 1, a front housing 12 is connected to the front end of the cylinder block 11, and a rear housing 13 is connected to the rear end of the cylinder block 11. The cylinder block 11, the front housing 12, and the rear housing 13 constitute an entire housing of the variable displacement compressor 10.

  A rotary shaft 14 is rotatably supported by the front housing 12 and the cylinder block 11 that form the control pressure chamber 121. The rotating shaft 14 obtains a rotational driving force from an external driving source (for example, a vehicle engine) through an electromagnetic clutch (not shown).

  A rotating support 15 is fixed to the rotating shaft 14, and a swash plate 16 is supported on the rotating shaft 14 so as to be slidable and tiltable in the axial direction of the rotating shaft 14. The swash plate 16 can tilt in the axial direction of the rotary shaft 14 and rotates integrally with the rotary shaft 14 by linking a guide hole 151 formed in the rotary support 15 and a guide pin 17 provided on the swash plate 16. Is possible.

  The inclination angle of the swash plate 16 is changed based on the pressure control in the control pressure chamber 121. The maximum inclination angle of the swash plate 16 is defined by the contact between the swash plate 16 and the rotary support 15. The swash plate 16 shown by a chain line in FIG.

  Pistons 18 are accommodated in a plurality of cylinder bores 111 (only one is shown in FIG. 1) penetrating the cylinder block 11. The piston 18 defines a compression chamber 112 in the cylinder bore 111. The rotational movement of the swash plate 16 is converted into the back-and-forth reciprocating movement of the piston 18 via the pair of front and rear shoes 19, and the piston 18 reciprocates in the cylinder bore 111.

  When the piston 18 moves backward in the cylinder bore 111 (moving from the right side to the left side in FIG. 1), the refrigerant in the suction chamber 20, which is the suction pressure region in the rear housing 13, pushes the suction valve 21 away from the suction port 22. 112 is inhaled. When the piston 18 moves forward in the cylinder bore 111 (moving from the left side to the right side in FIG. 1), the refrigerant in the compression chamber 112 pushes away the discharge valve 23 and discharges from the discharge port 24 as a discharge pressure region in the rear housing 13. It is discharged into the chamber 25.

  The rear housing 13 is provided with a capacity control valve 44. The refrigerant in the discharge chamber 25 can be supplied to the control pressure chamber 121 via the supply passage 45 and the capacity control valve 44, and the refrigerant in the control pressure chamber 121 flows out to the suction chamber 20 via the discharge passage 46. . The capacity control valve 44 adjusts the passage cross-sectional area in the supply passage 45 that connects the discharge chamber 25 and the control pressure chamber 121 to adjust the refrigerant supply flow rate from the discharge chamber 25 to the control pressure chamber 121. When the refrigerant supply flow rate increases, the pressure in the control pressure chamber 121 increases, and when the refrigerant supply flow rate decreases, the pressure in the control pressure chamber 121 decreases.

  The refrigerant in the discharge chamber 25 is discharged to the external refrigerant circuit 26 via the discharge passage 27. The refrigerant discharged to the external refrigerant circuit 26 returns to the suction chamber 20 via the suction passage 28. On the external refrigerant circuit 26, a heat exchanger 261 that takes heat from the refrigerant, an expansion valve 262, and an evaporator 263 that transfers heat from the surroundings to the refrigerant are provided. When the temperature of the evaporator 263 on the external refrigerant circuit 26 rises above a predetermined temperature, the electromagnetic clutch described above is turned on and the compressor 10 is operated.

A check valve 29 is provided in the suction passage 28. The check valve 29 prevents the refrigerant from flowing backward from the suction chamber 20 side to the external refrigerant circuit 26 side.
As shown in FIG. 2A, a circular valve plate 31 is integrally formed in a cylinder of a cylindrical case 30 constituting the check valve 29, and a circular support is provided on the end surface of the case 30. The plate 32 is fixed. A circular first valve element 33 is accommodated in the cylinder of the case 30 between the support plate 32 and the valve plate 31 so as to be movable in the cylinder direction of the case 30, and the first valve element 33 and the support plate 32 are accommodated. The second valve element 34 is accommodated in the cylinder of the case 30 so as to be movable in the cylinder direction of the case 30. The second valve body 34 includes a circular disc portion 35 and a cylindrical tube portion 36 integrally formed on the periphery of the disc portion 35. A coil spring 37 is interposed between the disc portion 35 of the second valve body 34 and the support plate 32. The coil spring 37 biases the second valve body 34 toward the valve plate 31.

  As shown in FIG. 4, the valve plate 31 is formed with a pair of fan-shaped valve holes 311 and 312 having the same shape and size. The valve holes 311 and 312 are arranged at rotationally symmetric positions of 120 ° around the central axis L passing through the circular center C1 of the circular valve plate 31. The valve holes 311 and 312 are surrounded by an annular portion 313 and are partitioned by a bridge 314 and a fan-shaped shielding portion 315. The total cross-sectional area of the valve holes 311 and 312 is larger than half of the circular area of the valve plate 31 and is close to 2/3 of the circular area of the valve plate 31 (the pressure receiving area in the moving direction of the valve bodies 33 and 34). .

  Three fan-shaped openings 321 are formed in the support plate 32. The first valve body 33 is formed with a pair of fan-shaped first windows 331 and 332, and the second valve body 34 is formed with a pair of fan-shaped second windows 341 and 342.

  The three through holes 321 in the support plate 32 are formed in the same shape and the same size, and each of the through holes 321 rotates by 120 ° around the central axis L passing through the circle center Co of the circular support plate 32. It is arranged in a symmetrical position.

  The three openings 321 are surrounded by the annular portion 322 and are partitioned by the three bridges 323. A second stopper 43 is erected on each bridge 323 so as to extend toward the valve plate 31, and a guide bar 39 extends toward the valve plate 31 at the intersection of each bridge 323 and the annular portion 322. It is erected. A first stopper 40 is erected so as to extend to the valve plate 31 side at an annular portion 322 in the middle of adjacent guide bars 39.

  The three first stoppers 40 are arranged at a rotationally symmetric position of 120 ° around the central axis L, and the three second stoppers 43 are arranged at a rotationally symmetric position of 120 ° around the central axis L Has been. The three guide bars 39 are disposed at rotationally symmetric positions of 120 ° with the central axis L as the center.

  The first windows 331 and 332 of the first valve body 33 are formed in the same shape and size as the valve holes 311 and 312, and the first windows 331 and 332 are the circular centers C <b> 2 of the circular first valve body 33. Is arranged at a rotationally symmetric position of 120 ° with the central axis L passing through the center. The sum total of the passage sectional areas in the first windows 331 and 332 is larger than half of the circular area of the first valve body 33 and is close to 2/3 of the circular area of the first valve body 33.

  The first windows 331 and 332 are surrounded by an annular portion 333, and are partitioned by a bridge 334 and a fan-shaped first shielding portion 335. Three guide holes 38 are disposed in the annular portion 333 at a rotationally symmetric position of 120 ° with the central axis L as the center. One guide hole 38 is disposed at the intersection of the bridge 334 and the annular portion 333.

  The second windows 341, 342 of the second valve body 34 are formed in the same shape and size as the valve holes 311, 312, and the second windows 341, 342 are central axes passing through the circle center C 3 of the disc part 35. It is arranged at a rotationally symmetric position of 120 ° around L. The total cross-sectional area of the passages in the second windows 341 and 342 is larger than half of the circular area of the second valve body 34 and is close to 2/3 of the circular area of the disc portion 35 of the second valve body 34. The second windows 341 and 342 are surrounded by an annular portion 343 and are partitioned by a bridge 344 and a fan-shaped second shielding portion 345.

  Three guide holes 41 are arranged in the annular portion 343 at a rotationally symmetric position of 120 ° about the central axis L. One guide hole 41 is disposed at the intersection of the bridge 344 and the annular portion 343.

Three through holes 42 are arranged in the annular portion 343 at a rotationally symmetric position of 120 ° about the central axis L. The through hole 42 is disposed in the middle between the adjacent guide holes 41.
As shown in FIGS. 2A and 2B, a guide bar 39 is passed through the guide holes 41 and 38, and a first stopper 40 is passed through the through hole 42. The guide holes 41 and 38 and the guide bar 39 move the first valve body 33 and the second valve body 34 in the cylinder direction of the case 30 (direction of contact and separation between the first valve body 33 and the second valve body 34). A guide means is provided that guides in a non-rotatable manner.

  As shown in FIGS. 3A and 3B, in the guide bar 39, the valve hole 311 of the valve plate 31 and the first shielding portion 335 of the first valve body 33 overlap when viewed in the cylindrical direction of the case 30. As shown in FIG. Further, the guide bar 39 is passed through the guide hole 41 so that the first window 331 of the first valve body 33 and the second shielding part 345 of the second valve body 34 overlap each other when viewed in the cylinder direction of the case 30. ing. The first windows 331 and 332 of the first valve body 33 are shifted by 120 ° with respect to the valve holes 311 and 312 of the valve plate 31, and the second windows 341 and 342 of the second valve body 34 are the first valve The first windows 331 and 332 of the body 33 are shifted by 120 ° in the shifting direction of the first windows 331 and 332 with respect to the valve holes 311 and 312. That is, the valve holes 311, 312, the first windows 331, 332, and the second windows 341, 342 are formed so as to be shifted to positions that are 120 ° rotationally symmetric about the central axis L.

  FIG. 2A shows the valve open state of the check valve 29 when the variable displacement compressor 10 is in an operating state and the refrigerant passes through the suction passage 28. In this state, the second shielding portion 345 and the bridge 344 of the second valve body 34 are in contact with the tip of the second stopper 43 against the spring force of the coil spring 37, and the first shielding portion of the first valve body 33. 335 and the bridge 334 are in contact with the tip of the first stopper 40. The refrigerant passes through the valve holes 311 and 312, the first windows 331 and 332, the second windows 341 and 342, and the passage 321. The first stopper 40 restricts the first valve body 33 to a first maximum separation position that is farthest from the contact position of the first valve body 33 that contacts the valve plate 31. The second stopper 43 restricts the second valve body 34 to a second maximum separated position farthest from the first valve body 33 located at the first maximum separated position.

  FIG. 2B shows a closed state of the check valve 29 when the variable displacement compressor 10 is in an operation stopped state and the refrigerant does not pass through the suction passage 28. In this state, due to the spring force of the coil spring 37, the disc portion 35 of the second valve body 34 is in contact with the first valve body 33, and the second shielding portion 345 of the second valve body 34 is the first of the first valve body 33. The window 331 (a part of the first window 331, 332) is shielded, and the first shielding part 335 of the first valve body 33 is the second window 342 of the second valve body 34 (a part of the first window 341, 342). Shield. Further, the first valve body 33 is in contact with the valve plate 31, the first shielding portion 335 of the first valve body 33 shields the valve hole 311 (part of the valve holes 311, 312) of the valve plate 31, and the valve plate 31. The shielding portion 315 shields the first window 332 (a part of the first windows 331 and 332) of the first valve body 33. That is, when the valve plate 31 and the first valve body 33 are in contact with each other, and the first valve body 33 and the second valve body 34 are in contact with each other, the passage sectional area of the check valve 29 as a whole is zero.

In the first embodiment, the following effects can be obtained.
(1) In the present embodiment, the first windows 331 and 332 are shifted by 120 ° with respect to the valve holes 311 and 312, and the first windows 331 and 332 are shifted in the shifting direction of the first windows 331 and 332 with respect to the valve holes 311 and 312. The second windows 341 and 342 are shifted by 120 ° with respect to 332. Therefore, the passage cross-sectional areas of the valve holes 311, 312, the first windows 331, 332 and the second windows 341, 342 are made larger than the pressure receiving area of the circular valve plate 31, that is, half the circular area of the valve plate 31. be able to.

  (2) The first windows 331 and 332 are shifted by 120 ° with respect to the valve holes 311 and 312, and the first windows 331 and 332 are shifted relative to the first windows 331 and 332 in the shifting direction of the first holes 331 and 332 with respect to the valve holes 311 and 312. The configuration in which the two windows 341 and 342 are shifted by 120 ° can increase the passage sectional areas of the valve holes 311 and 312, the first windows 331 and 332, and the second windows 341 and 342 to nearly 2/3 of the circular area of the valve plate 31. . In other words, the configuration in which the valve hole, the first window, and the second window are shifted around the central axis L increases the passage cross-sectional area of the valve holes 311 and 312, the first windows 331 and 332, and the second windows 341 and 342. It is suitable.

(3) If the first valve body 33 and the second valve body 34 are close to or in contact with each other when the refrigerant is flowing forward, the cross-sectional area of the passage at the time of the positive flow decreases.
When the refrigerant is flowing forward, the first stopper 40 and the second stopper 43 restrict the first valve body 33 and the second valve body 34 to positions separated from each other. Therefore, the 1st valve body 33 and the 2nd valve body 34 do not approach or contact.

  (4) When the first valve body 33 is in contact with the valve plate 31, the first windows 331 and 332 overlap the valve holes 311 and 312, or the second windows 341 and 342 overlap the first windows 331 and 332. In such a case, backflow prevention becomes poor.

  Since the first valve body 33 and the second valve body 34 are guided by the guide bar 39 so as to be movable in the direction of contacting and separating from each other and not to rotate, the first valve body 33 and the second valve body 34 are Does not rotate. Therefore, when the first valve body 33 is in contact with the valve plate 31, the first windows 331 and 332 overlap the valve holes 311 and 312, and the second windows 341 and 342 overlap the first windows 331 and 332. Never do.

  (5) When the refrigerant tries to flow backward, the coil spring 37 arranges the second valve element 34 at a position in contact with the first valve element 33 and arranges the first valve element 33 at a position in contact with the valve plate 31. The adoption of the coil spring 37 ensures the prevention of the check valve 29 regardless of the orientation of the check valve 29.

  (6) When the temperature of the evaporator 263 on the external refrigerant circuit 26 rises, the compressor 10 is operated. If the reverse flow of the refrigerant from the suction chamber 20 to the external refrigerant circuit 26 occurs immediately after the operation of the compressor 10 is stopped due to the temperature drop of the evaporator, the evaporator is heated to increase the temperature, and the compressor 10 Will be resumed. The check valve 29 prevents the refrigerant from flowing back from the suction chamber 20 to the external refrigerant circuit 26 when the operation of the compressor 10 is stopped.

  Since the maximum passage sectional area of the check valve 29 for preventing the refrigerant backflow can be made larger than that of the check valve disclosed in Patent Document 1, the passage sectional area of the suction passage 28 can be reduced. This contributes to downsizing of the rear housing 13, that is, downsizing of the compressor 10.

Next, a second embodiment shown in FIGS. 5 and 6A and 6B will be described. The same reference numerals are used for the same components as those in the first embodiment, and detailed description thereof is omitted.
A valve hole 316 larger than a semicircle is formed in the valve plate 31. The first valve body 33 is formed with a pair of first windows 336 and 337 smaller than a semicircle, and the second valve body 34 is formed with a second window 346 larger than the semicircle. The sum total of the passage cross-sectional areas of the first windows 336 and 337 is larger than a semicircle.

  When the first valve body 33 is in contact with the valve plate 31, the shielding part 338 between the first windows 336 and 337 of the first valve body 33 shields a part of the valve hole 316, and the shielding part of the valve plate 31. 317 shields the first window 337 of the first valve body 33 (part of the first windows 336 and 337). Further, the shielding part 347 of the second valve body 34 shields one of the first windows 336 and 337 (a part of the first windows 336 and 337), and the shielding part 338 of the first valve body 33. Shields a part of the second window 346 of the second valve body 34.

In the second embodiment, the same effects as the items (1) and (3) to (6) in the first embodiment can be obtained.
In the present invention, the following embodiments are also possible.

  In the first embodiment, the number of valve bodies may be three or more. When the number of valve bodies is n (≧ 2), the passage cross-sectional area of the valve hole and the window of each valve body can be close to n / (n + 1) times the pressure receiving area of the valve body.

  A check valve 29 may be provided in the discharge passage 27 so as to prevent the reverse flow of the refrigerant in the discharge passage 27. As the compressor in this case, a compressor (clutchless compressor) that is operated while an external drive source (for example, a vehicle engine) is operating is preferable. In the clutchless compressor, when substantial discharge is not performed, it is desirable to stop the refrigerant circulation in the external refrigerant circuit 26, and for this purpose, a check valve 29 may be provided in the discharge passage 27.

The sectional side view of the compressor which shows 1st Embodiment. (A), (b) is a sectional side view of a check valve. (A) is the sectional view on the AA line of Fig.2 (a). (B) is the BB sectional drawing of Fig.2 (a). FIG. The disassembled perspective view which shows 2nd Embodiment. (A), (b) is sectional drawing.

Explanation of symbols

  10: Variable capacity compressor. 13 ... A rear housing constituting the housing. 20: A suction chamber as a suction pressure region. 20: Discharge chamber as a discharge pressure region. 26: External refrigerant circuit. 28: Inhalation passage. 29 ... Check valve. 31 ... Valve plate. 311, 312 ... valve holes. 33 ... 1st valve body. 331, 332, 336, 337 ... the first window. 335 ... 1st shielding part. 338: A shielding part. 34 ... Second valve body. 341, 342, 346 ... second window. 345 ... 2nd shielding part. 347: A shielding part. 37 ... Coil spring. 39: A guide bar constituting guide means. 40: First stopper. 38, 41 ... Guide holes constituting guide means. 43 ... Second stopper. C1, C2, C3 ... Center of the circle. L: Center axis.

Claims (9)

In a check valve that prevents back flow of fluid,
A valve plate,
A plurality of valve bodies disposed downstream of the valve plate,
One of the plurality of valve bodies can be contacted and separated from the valve plate, adjacent valve bodies of the plurality of valve bodies can be contacted and separated from each other, and the valve plate has a valve hole. Each of the plurality of valve bodies has a window, the valve body that can contact and separate from the valve plate has a shielding portion that shields a part of the valve hole, and the valve plate A shielding portion that shields a part of the valve body window that can contact and separate from the valve plate, wherein one of the adjacent valve bodies is a part of the other window of the adjacent valve body; And the other of the adjacent valve bodies has a shielding part that shields a part of the one window, and the passage of the valve hole, the one window, and the other window is cut off. The area is half or more of the pressure receiving area in the valve plate, the valve body that can be contacted and separated from the valve plate and the valve plate are in contact, and the adjacent valve body is in contact, Check valve cross-sectional area is zero in the entire check valve.   The plurality of valve bodies are two of a first valve body that contacts and separates from the valve plate and a second valve body that contacts and separates from the first valve body, and the first valve body includes the valve hole. A first shielding part that shields a part of the first window and a first window, and the second valve body includes a second shielding part that shields a part of the first window and a second window. The check valve according to Item 1.   A first stopper for restricting the first valve body to a first maximum separated position farthest from a contact position of the first valve body in contact with the valve plate; and the first valve body in the first maximum separated position. The check valve according to claim 2, wherein a second stopper that restricts the second valve body is provided at a second maximum separation position farthest from the first position.   The valve plate, the first valve body, and the second valve body are formed in a circular shape, and the valve hole, the first window, and the second window are the valve plate, the first valve body, and the second valve body, respectively. The check valve according to any one of claims 2 and 3, wherein the check valve is formed so as to be shifted to a rotationally symmetric position about a central axis passing through each circle center of the second valve body.   The check valve according to claim 4, wherein the valve hole, the first window, and the second window are formed so as to be shifted to a position that is rotationally symmetrical by 120 ° about the central axis.   A guide means is provided for guiding the first valve body and the second valve body so as to be movable and non-rotatable in the direction of contact and separation between the first valve body and the second valve body. The check valve according to any one of claims 4 and 5.   A spring is provided for biasing the second valve body toward a position in contact with the first valve body and biasing the first valve body toward a position in contact with the valve plate. The check valve according to claim 6.   When there are n (an integer greater than or equal to 3) valve bodies, the valve holes and the windows of each of the n valve bodies are centered on a central axis that passes through the center of each circle of the valve plate and each valve body. The check valve according to claim 1, wherein the check valve is formed so as to be shifted to a rotationally symmetrical position of 360 ° / (n + 1). In the compressor that sucks the refrigerant from the external refrigerant circuit to the suction pressure region in the housing and discharges the refrigerant from the discharge pressure region in the housing to the external refrigerant circuit,
9. A suction passage extending from the external refrigerant circuit through the housing to the suction pressure region is provided, and the check valve according to claim 1 is a refrigerant in the suction passage. A compressor provided in the suction passage so as to prevent backflow of the air.

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