JP2009203888A - Variable displacement type swash plate compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a variable displacement type swash plate compressor capable of securing displacement restorability during low rotation, and capable of reducing power during high rotation. <P>SOLUTION: The variable displacement type swash plate compressor 10 is equipped with a crank chamber 16, a rotary shaft 17, a swash plate 23 and a piston 29, and by changing a pressure Pc of the crank chamber 16 on the basis of opening adjustment of a displacement control valve 35 provided in a supply air passage 42 connecting the crank chamber 16 and a delivery chamber 39, a tilt angle of the swash plate 23 is changed, and delivery displacement is controlled. A first air bleed passage 48 and a second air bleed passage 58 connecting the crank chamber 16 and an intake chamber 38 are respectively provided in the rotary shaft 17 and a cylinder block 12, the first air bleed passage 48 has an opening and closing valve 50 moved in a direction closing the first air bleed passage 48 by centrifugal force following rotation of the rotary shaft 17, and the second air bleed passage 58 has a throttle hole 59 used as a fixed throttle. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a variable displacement compressor used in, for example, a vehicle air conditioner.

Generally, a variable capacity compressor (hereinafter simply referred to as “compressor”) capable of variably controlling a discharge capacity is known as a compressor used in a vehicle air conditioner or the like.
In this type of compressor, the pressure in the crank chamber containing the swash plate is controlled using a capacity control valve to adjust the tilt angle of the swash plate and change the stroke of each piston to change the discharge capacity. I am letting.

For example, in the prior art disclosed in Patent Document 1, the open / close valve 33 is disposed in the middle of the extraction passage 29 that connects the crank chamber 15 and the suction pressure region 13a. The on-off valve 33 includes a valve body 36, a spring 37 that biases the valve body 36 in the opening direction, and a counterweight 38. When the rotational speed of the rotary shaft 16 exceeds a predetermined value, the valve body 36 is moved to a position where the valve hole 34 is closed by centrifugal force acting on the counterweight 38. Thereby, the extraction passage 29 is shut off, and the extraction of the refrigerant gas from the crank chamber 15 to the suction pressure region 13a via the extraction passage 29 is stopped. For this reason, during the compression operation with a large discharge capacity, if the rotational speed of the rotary shaft 16 exceeds a predetermined value, the bleed passage 29 is closed by the on-off valve 33, and the pressure in the crank chamber 15 is moderated by the inflow of blow-by gas. Enhanced. Therefore, the pressure in the crank chamber 15 can be gradually increased to reduce the discharge capacity, the compression load is reduced, and the surface pressure of each sliding portion can be reduced.
Japanese Patent Laid-Open No. 10-54350 (pages 4-6, FIGS. 1-3)

  However, in the prior art disclosed in Patent Document 1, when the rotational speed of the rotary shaft 16 is equal to or greater than a predetermined value, the bleed passage 29 is closed by the on-off valve 33 and the crank chamber 15 is connected to the suction pressure region 13a. The derived amount of refrigerant gas becomes zero. In this state, if an attempt is made to increase the discharge capacity of the compressor, the extraction passage 29 is closed and the refrigerant gas from the crank chamber 15 is not rapidly extracted, and the discharge capacity of the compressor increases. It takes a long time until the capacity is restored.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a variable capacity swash plate compressor capable of ensuring capacity return at low revolutions and reducing power at high revolutions. It is to provide.

  In order to achieve the above object, the invention described in claim 1 is a housing, a crank chamber defined in the housing, a rotating shaft rotatably supported in the crank chamber, and an integral body with the rotating shaft. A swash plate that is rotatably and tiltably connected, and a piston that is reciprocally accommodated in a cylinder bore formed in the housing, provided in an air supply passage that connects the crank chamber and a discharge pressure region. In the variable displacement swash plate type compressor, the discharge angle is controlled by changing the inclination angle of the swash plate by changing the pressure of the crank chamber based on the adjustment of the opening of the capacity control valve. A bleed passage that connects the chamber and the suction pressure region is provided, and the bleed passage has an on-off valve and a fixed throttle that are moved in a direction to close the bleed passage by a centrifugal force accompanying the rotation of the rotating shaft. It is characterized in.

According to the first aspect of the present invention, at the time of low rotation, since the centrifugal force accompanying the rotation of the rotating shaft is small, the on-off valve is held with the bleed passage opened. The extraction passage is provided with a fixed throttle that always communicates the crank chamber and the suction pressure region. Accordingly, the bleed passage provided with the on-off valve and the bleed passage provided with the fixed throttle are both in an open state, so that the refrigerant gas flows out from the crank chamber to the suction pressure region quickly. The capacity recoverability at the time of start-up, that is, the return from the OFF operation to the capacity operation can be promptly performed.
On the other hand, at the time of high rotation, the on-off valve is closed by being moved in the direction of closing the extraction passage by the centrifugal force accompanying the rotation of the rotation shaft. Therefore, since only the fixed throttle is in an open state, the amount of refrigerant gas flowing out from the crank chamber to the suction pressure region is reduced, but the inertial force acting on the piston and the swash plate is increased due to high rotation. It is possible to prevent the capacity recoverability at the start-up from being lowered. In addition, at this time, since the flow rate of the refrigerant gas used for the original purpose is increased by reducing the flow rate of the refrigerant gas circulated internally, the power of the compressor can be reduced.

According to a second aspect of the present invention, in the variable capacity swash plate compressor according to the first aspect, the extraction passage includes a first extraction passage formed in the rotating shaft and a second extraction passage formed in the housing. And an opening / closing valve is provided in the first bleed passage and a fixed throttle is provided in the second bleed passage.
According to the second aspect of the present invention, since the opening / closing valve may be provided in the first extraction passage formed in the rotating shaft, the opening / closing operation of the opening / closing valve is performed using the centrifugal force generated by the rotation of the rotating shaft. Can do. Further, by forming the second extraction passage in the housing separately from the first extraction passage, it is possible to easily dispose a fixed throttle having a certain amount of gas outflow.

According to a third aspect of the present invention, in the variable displacement swash plate compressor according to the second aspect, one end side of the first bleed passage is opened to the crank chamber, and the other end side of the first bleed passage is the open / close state. A valve is arranged.
According to the third aspect of the present invention, one end of the first extraction passage formed in the rotating shaft is opened in the crank chamber, and the opening and closing valve is provided at the other end, so that the opening and closing operation of the first extraction passage is easily performed. be able to.

According to a fourth aspect of the present invention, in the variable displacement swash plate compressor according to the first aspect, the extraction passage includes a passage formed at the center of the rotating shaft, and one end side of the passage is connected to the crank chamber. The opening / closing valve is disposed on the other end side of the passage, and the fixed throttle is formed on the other end side of the rotating shaft.
According to the fourth aspect of the present invention, the fixed throttle may be provided on the same member as the rotary shaft provided with the bleed passage having the on-off valve. Cost can be reduced.

The invention according to claim 5 is the variable displacement swash plate compressor according to any one of claims 1 to 4, wherein the on-off valve biases the valve body and the valve body toward an open position. An urging member and a counterweight that moves the valve body to a closed position against the urging force of the urging member by a centrifugal force accompanying the rotation of the rotating shaft.
According to the fifth aspect of the present invention, the counterweight is moved in the outer peripheral direction against the urging force of the urging member by the centrifugal force acting on the counterweight when the rotation speed of the rotating shaft becomes high. Is moved to the closed position. On the other hand, when the rotational speed of the rotating shaft is low, the urging force of the urging member becomes dominant, so that the valve body is held in the open position. Thus, the structure of the on-off valve is simple, and the extraction passage can be reliably opened and closed according to the number of rotations of the rotating shaft.

  According to the present invention, by providing the fixed throttle that is always in communication with the on-off valve that is movable by the centrifugal force accompanying the rotation in the extraction passage, it is possible to ensure capacity return at low speeds and at the same time the compressor at high speeds. The power can be reduced.

(First embodiment)
A variable capacity swash plate compressor (hereinafter simply referred to as “compressor”) according to a first embodiment of the present invention will be described below with reference to FIGS.
The compressor 10 shown in FIG. 1 includes a housing 11 that is an outer shell of the compressor 10. The housing 11 includes a cylinder block 12 having a plurality of cylinder bores 12 a and a cylinder block 12. The front housing 13 is joined to the front side, and the rear housing 14 is joined to the rear side of the cylinder block 12. In FIG. 1, the left side is the front side and the right side is the rear side.
The front housing 13, the cylinder block 12, and the rear housing 14 are integrally fixed by fastening the through bolts 15 passed from the front housing 13 to the rear housing 14 in the front-rear direction, and the housing 11 is formed.

A crank chamber 16 is formed in the front housing 13, and the crank chamber 16 is closed by the cylinder block 12 on the rear side.
A rotary shaft 17 is provided so as to penetrate the vicinity of the center of the crank chamber 16. The rotary shaft 17 is provided with a radial bearing 18 provided on the front housing 13 and another radial bearing 19 provided on the cylinder block 12. It is supported rotatably by.
A shaft sealing mechanism 20 is provided in front of the radial bearing 18 that supports the front portion of the rotating shaft 17 so as to be in sliding contact with the circumferential surface of the rotating shaft 17.
The shaft sealing mechanism 20 includes a lip seal member and the like, and prevents refrigerant in the crank chamber 16 from leaking from between the front housing 13 and the rotating shaft 17.
In this embodiment, the front end of the rotary shaft 17 is connected to an external drive source via a power transmission mechanism (not shown), and the rotary shaft 17 can be rotated by the external drive source.

A lug plate 21 is fixed to the rotary shaft 17 in the crank chamber 16 so as to be integrally rotatable.
A swash plate 23 constituting a capacity variable mechanism 22 is supported on the rotary shaft 17 behind the lug plate 21 so as to be slidable and tiltable in the axial direction of the rotary shaft 17.
A hinge mechanism 24 is interposed between the swash plate 23 and the lug plate 21, and the swash plate 23 is connected to the lug plate 21 and the rotating shaft 17 through the hinge mechanism 24 so as to be capable of synchronous rotation and tilting. ing.

A coil spring 25 is wound between the lug plate 21 and the swash plate 23 on the rotary shaft 17, and a slidable cylindrical body 26 urged rearward by the pressing of the coil spring 25 is a rotary shaft. 17 is inserted.
The swash plate 23 is always pressed backward, that is, in a direction in which the inclination angle of the swash plate 23 decreases, by the cylindrical body 26 that receives the urging force of the coil spring 25.
Here, the inclination angle of the swash plate 23 means an angle formed by the surface orthogonal to the rotation shaft 17 and the surface of the swash plate 23.
A stopper portion 23a projects from the front portion of the swash plate 23, and the maximum inclined position of the swash plate 23 is regulated by the stopper portion 23a coming into contact with the lug plate 21, as shown in FIG. It has become. A retaining ring 27 is attached to the rotary shaft 17 behind the swash plate 23,
When the rear part of the swash plate 23 abuts against the retaining ring 27, the minimum inclination angle position of the swash plate 23 is regulated. 1 indicates the maximum tilt angle position of the swash plate 23, and the position indicated by the two-dot chain line in FIG. 1 indicates the minimum tilt angle position of the swash plate 23.

In each cylinder bore 12 a of the cylinder block 12, single-headed pistons 29 are accommodated so as to be able to reciprocate, and the necks of these pistons 29 are anchored to the outer periphery of the swash plate 23 via shoes 30.
When the swash plate 23 is rotationally moved with the rotation of the rotating shaft 17, each piston 29 is reciprocated through the shoe 30.
On the other hand, as shown in FIG. 1, the front side of the rear housing 14 and the rear side of the cylinder block 12 are joined via a valve plate 32.

A suction chamber 38 is formed at the center of the rear housing 14, and the suction chamber 38 communicates with the compression chamber 31 in the cylinder bore 12 a by a suction port 36 provided in the valve plate 32.
A discharge chamber 39 is formed on the outer peripheral side of the rear housing 14, and the discharge chamber 39 and the suction chamber 38 are separated from each other by a partition wall 14a.
The valve plate 32 is for forming the compression chamber 31 together with the piston 29 in the cylinder bore 12a, and has a suction port 36 communicating with the suction chamber 38 on the rear housing 14 side and a discharge port 37 communicating with the discharge chamber 39. Each has a suction valve 33 and a discharge valve 34.

By the way, the refrigerant in the suction chamber 38 is sucked into the compression chamber 31 through the suction port 36 and the suction valve 33 as the piston 29 moves from the top dead center position to the bottom dead center position.
The refrigerant sucked into the compression chamber 31 is compressed to a predetermined pressure by moving from the bottom dead center position of the piston 29 to the top dead center position, and is discharged to the discharge chamber 39 through the discharge port 37 and the discharge valve 34. The

The cylinder block 12 and the rear housing 14 are provided with an air supply passage 42 that allows the discharge chamber 39 and the crank chamber 16 to communicate with each other. An electromagnetic capacity control valve 35 is disposed in the air supply passage 42. The capacity control valve 35 communicates with the suction chamber 38 via the pressure sensitive passage 61. The valve opening of the capacity control valve 35 can be detected by detecting the pressure in the suction chamber 38 or by an external command.
By adjusting the valve opening degree of the capacity control valve 35, the supply amount of the high-pressure refrigerant gas supplied from the discharge chamber 39 to the crank chamber 16 through the air supply passage 42 is changed. Then, the difference in pressure between the crank chamber 16 and the compression chamber 31 with the piston 29 interposed therebetween is changed, and the inclination angle of the swash plate 23 is changed. Thereby, the stroke of the piston 29 is changed, and the discharge capacity is adjusted.

In the center of the cylinder block 12, a shaft hole 43 for inserting the rotary shaft 17 on the front end side and a housing recess 44 communicating with the shaft hole 43 on the rear end side are formed. A rear end portion of the rotating shaft 17 is inserted into the shaft hole 43 through a radial bearing 19.
A passage hole 45 constituting a first extraction passage 48 is formed at the center of the rotating shaft 17, and the passage hole 45 is opened to the crank chamber 16 at the front end side in the vicinity of the radial bearing 18 and the shaft seal mechanism 20. ing. An opening / closing valve 50 is disposed at the rear end of the rotating shaft 17 in the housing recess 44. The on-off valve 50 will be described in detail later. A plug body 60 is fitted to the rear end of the passage hole 45 to close the rear end portion of the passage hole 45.

A thrust bearing 46 and a support spring 47 are interposed between the rear end of the rotating shaft 17 and the valve plate 32.
The housing recess 44 and the suction chamber 38 are communicated with each other through a communication hole 49 formed at the center of the valve plate 32. The communication hole 49 is formed as a throttle hole that restricts the amount of refrigerant gas flowing out from the crank chamber 16 to the suction chamber 38.
The first extraction passage 48 includes a passage hole 45, an accommodation recess 44, an on-off valve 50, and a communication hole 49, and is formed so as to connect the crank chamber 16 and the suction chamber 38.

The on-off valve 50 is provided so as to open and close the first extraction passage 48. As shown in FIG. 2, the rear end peripheral surface of the rotary shaft 17 is cut at the upper and lower portions to form planar seat surfaces 51 and 52. An opening / closing valve hole 53 communicating with the seat surface 51 and the seat surface 52 and communicating with the passage hole 45 is formed in the radial direction. The opening / closing valve hole 53 has a large hole diameter on the seating surface 51 side.
The on-off valve body 54 as a valve body is inserted into the on-off valve hole 53 so as to be openable and closable.
An on-off valve body 54 is arranged on the seat surface 51 side, a counter weight 55 as a mass body is arranged on the seat surface 52 side, and the on-off valve body 54 and the counter weight 55 are integrally connected by a connecting portion 56. .
A spring 57 is provided between the seat surface 51 and the on-off valve body 54 as an urging member that urges the on-off valve body 54 toward the open position.

When the rotational speed of the rotary shaft 17 becomes high, the centrifugal force acting on the counterweight 55 increases, and the counterweight 55 is moved away from the axis of the rotary shaft 17. For this reason, the on-off valve body 54 moves to the axial center side of the rotating shaft 17 against the urging force of the spring 57, contacts the seat surface 51, and the on-off valve hole 53 is closed.
On the other hand, when the rotational speed of the rotary shaft 17 is low, the centrifugal force acting on the counterweight 55 is small, so that the biasing force of the spring 57 biasing the open / close valve body 54 toward the open position is dominant. Become. For this reason, the on-off valve body 54 is moved away from the axis of the rotating shaft 17 by the biasing force of the spring 57, and the on-off valve hole 53 is opened.
The on-off valve 50 shown in FIGS. 1 and 2 represents a valve opening state at a low rotation, and the on-off valve 50 shown in FIG. 3 represents a valve closing state at a high rotation.

  As shown in FIG. 1, the second extraction passage 58 that connects the crank chamber 16 and the suction chamber 38 is provided in the cylinder block 12. A throttle hole 59 corresponding to a fixed throttle for narrowing the flow rate of the refrigerant gas is formed in the valve plate 32 in the second extraction passage 58. The second extraction passage 58 is formed as a passage that always communicates the crank chamber 16 and the suction chamber 38.

FIG. 4 is a block diagram schematically showing this embodiment.
The discharge chamber 39 and the crank chamber 16 are communicated with each other by an air supply passage 42, and a capacity control valve 35 is provided in the middle. The crank chamber 16 and the suction chamber 38 are communicated with each other by a first bleed passage 48 and a second bleed passage 58. The first bleed passage 48 is provided with an opening / closing valve 50 that is operated by centrifugal force. An aperture hole 59 is formed as a fixed aperture.

FIG. 5 is a schematic diagram showing the relationship between the rotational speed N of the rotary shaft 17 and the throttle hole total cross-sectional area As in the present embodiment. Here, if the cross-sectional area of the communication hole 49 provided in the first bleed passage 48 is Aa and the cross-sectional area of the throttle hole 59 provided in the second bleed passage 58 is Ab, the first bleed air during low rotation Since the on-off valve 50 provided in the passage 48 is in the open position, the total sectional area As1 of the throttle hole in the open state is As1 = Aa + Ab. On the other hand, at the time of high rotation, the on-off valve 50 provided in the first bleed passage 48 is in the closed position and only the second bleed passage 58 is open, so that the total sectional area As2 of the throttle hole in the open state is rotated. As2 = Ab at a number Nc1 or more.
The flow rate of the refrigerant gas flowing out from the crank chamber 16 to the suction chamber 38 via the first bleed passage 48 and the second bleed passage 58 is proportional to the total cross-sectional area As of this throttle hole, so that As1 = Aa + Ab at low rotation speed. The flow rate increases, and at high rotation, the flow rate decreases as As2 = Ab. The passage cross-sectional areas of Aa and Ab are set in advance to appropriate values that can achieve both capacity recovery and power reduction. When the on-off valve body 54 is fully open, the opening cross-sectional area of the on-off valve hole 53 is set to Aa or more.

Next, the operation of the variable displacement swash plate compressor configured as described above will be described.
When the rotary shaft 17 is rotated by an external drive source such as a vehicle engine, the swash plate 23 is integrally rotated via the lug plate 21 and the hinge mechanism 24. The rotational movement of the swash plate 23 is converted into the reciprocating linear movement of the piston 29 via the shoe 30, and the piston 29 is reciprocated in the cylinder bore 12a. By the reciprocation of the piston 29, the refrigerant gas is sucked into the compression chamber 31 from the suction chamber 38 via the suction port 36 and the suction valve 33, and is compressed until a predetermined pressure is reached. Through the discharge chamber 39. Most of the high-pressure refrigerant gas discharged to the discharge chamber 39 is guided to an external refrigerant circuit (not shown). A part of the high-pressure refrigerant gas is guided to the crank chamber 16 through the air supply passage 42 and is used for controlling the inclination angle of the swash plate 23.

By changing the opening of the capacity control valve 35 disposed in the air supply passage 42, the amount of refrigerant gas introduced from the discharge chamber 39 into the crank chamber 16 through the air supply passage 42 and the first extraction passage 48 are changed. In addition, the balance with the amount of refrigerant gas discharged from the crank chamber 16 to the suction chamber 38 through the second extraction passage 58 is controlled. By controlling the balance between the amount of refrigerant gas introduced into the crank chamber 16 and the amount of refrigerant gas derived from the crank chamber 16, the crank pressure Pc of the crank chamber 16 is determined.
When the opening degree of the capacity control valve 35 is changed and the crank pressure Pc of the crank chamber 16 is changed, the differential pressure in the crank chamber 16 and the compression chamber 31 via the piston 29 is changed, and the inclination angle of the swash plate 23 is changed. fluctuate. The stroke of the piston 29 is changed by changing the inclination angle of the swash plate 23, and the discharge capacity of the compressor is changed according to the change of the stroke of the piston 29.

Now, when the temperature in the passenger compartment is high and the cooling load is large, the suction pressure Ps in the suction chamber 38 is high, and there is almost no differential pressure between the compression chamber 31 and the crank pressure Pc in the crank chamber 16 via the piston 29 ( Ps≈Pc). At this time, the capacity control valve 35 is controlled in the closing direction, the supply passage 42 is shut off, and the introduction of the high-pressure refrigerant gas from the discharge chamber 39 to the crank chamber 16 is stopped. Further, since Ps≈Pc, the refrigerant gas is not led out from the crank chamber 16 to the suction chamber 38 through the first extraction passage 48 and the second extraction passage 58. For this reason, the swash plate 23 is disposed at the maximum inclination angle position shown by the solid line in FIG. 1, the stroke of the piston 29 is increased, and the compressor is operated with a large discharge capacity.
During such maximum capacity operation, the refrigerant is not circulated through the supply passage 42 and the first and second extraction passages 48 and 58, so the compressor is operated efficiently.

  Next, when the temperature in the passenger compartment decreases and the cooling load decreases, the suction pressure Ps in the suction chamber 38 decreases. At this time, the capacity control valve 35 is controlled in the direction in which the opening degree is opened in accordance with the decrease in the suction pressure Ps. Accordingly, high-pressure refrigerant gas is introduced from the discharge chamber 39 into the crank chamber 16 through the supply passage 42. As a result, the crank pressure Pc in the crank chamber 16 increases, and the differential pressure between the crank pressure Pc in the crank chamber 16 and the pressure in the compression chamber 31 via the piston 29 increases. In accordance with this differential pressure, the inclination angle of the swash plate 23 is reduced, and the discharge capacity is reduced.

  During such variable displacement operation, when the rotational speed of the rotary shaft 17 is low, the centrifugal force accompanying the rotation of the rotary shaft 17 is small, so the on-off valve 50 provided in the middle of the first extraction passage 48. The on-off valve body 54 is held in a state in which the on-off valve hole 53 is opened. The second bleed passage 58 is provided with a throttle hole 59 that always communicates the crank chamber 16 and the suction chamber 38. Accordingly, the first bleed passage 48 provided with the on-off valve 50 and the second bleed passage 58 provided with the throttle hole 59 are both open, so that the refrigerant from the crank chamber 16 to the suction chamber 38 can be obtained. The outflow of gas is performed quickly, and capacity control according to the cooling load is appropriately performed.

  On the other hand, when the rotational speed of the rotating shaft 17 is high, the centrifugal force accompanying the rotation of the rotating shaft 17 increases, and the centrifugal force acting on the counterweight 55 of the on-off valve 50 increases. Due to this centrifugal force, as shown in FIG. 3, the on-off valve body 54 moves against the urging force of the spring 57 toward the axial center of the rotating shaft 17, abuts against the seat surface 51, and the on-off valve hole 53 is closed. The Accordingly, the first bleed passage 48 provided with the on-off valve 50 is closed, and only the second bleed passage 58 provided with the throttle hole 59 is opened, so that the refrigerant from the crank chamber 16 to the suction chamber 38 is obtained. The amount of derived gas is reduced. As a result, the flow rate of the refrigerant gas used for the original purpose is increased by reducing the flow rate of the internally circulated refrigerant gas, so that the power of the compressor can be reduced.

Next, when the temperature in the passenger compartment further decreases and approaches the state where there is almost no cooling load, the suction pressure Ps in the suction chamber 38 further decreases, and the opening of the capacity control valve 35 becomes fully open. Become. In this state, a large amount of high-pressure refrigerant gas is introduced from the discharge chamber 39 into the crank chamber 16 through the supply passage 42. For this reason, the crank pressure Pc in the crank chamber 16 increases, and the differential pressure between the crank pressure Pc in the crank chamber 16 and the pressure in the compression chamber 31 via the piston 29 further increases. The swash plate 23 is disposed at a minimum inclination angle position indicated by a two-dot chain line in FIG. 1, the stroke of the piston 29 is further reduced, and the compressor is operated with a minimum discharge capacity.
In such an OFF capacity operation, the minimum capacity is not zero and has a slight capacity, but at the time of high rotation, the minimum capacity is further reduced by reducing the flow rate of the refrigerant gas circulated internally. Power reduction during OFF capacity operation can be achieved.

Next, capacity recovery at start-up will be described.
The return from the OFF operation to the capacity operation is affected by the derivation of the refrigerant gas from the crank chamber 16 to the suction chamber 38 via the first extraction passage and the second extraction passage.
When the rotary shaft 17 is at a low rotation speed, the first bleed passage 48 provided with the on-off valve 50 and the second bleed passage 58 provided with the throttle hole 59 are both open, so that the crank chamber The refrigerant gas is quickly led out from the suction chamber 16 to the suction chamber 38, and the crank pressure Pc in the crank chamber 16 can be quickly reduced, so that the capacity returnability at the time of startup can be improved.

Further, when the rotary shaft 17 is at a high rotation speed, the first bleed passage 48 provided with the on-off valve 50 is closed, and only the second bleed passage 58 provided with the throttle hole 59 is open. The amount of refrigerant gas discharged from the crank chamber 16 to the suction chamber 38 is reduced. However, since the inertial force acting on the piston 29 and the swash plate 23 becomes large at the time of high rotation, the displacement moves mainly due to the inertial force. Therefore, even if the amount of refrigerant gas derived is reduced, the capacity can be quickly restored at the time of startup.

The variable displacement swash plate compressor 10 according to this embodiment has the following effects.
(1) When the rotational speed of the rotating shaft 17 is low, the centrifugal force accompanying the rotation of the rotating shaft 17 is small, and therefore the on-off valve body 54 of the on-off valve 50 provided in the middle of the first extraction passage 48 is The on-off valve hole 53 is held open. The second bleed passage 58 is provided with a throttle hole 59 that always communicates the crank chamber 16 and the suction chamber 38. Accordingly, the first bleed passage 48 provided with the on-off valve 50 and the second bleed passage 58 provided with the throttle hole 59 are both open, so that the refrigerant from the crank chamber 16 to the suction chamber 38 can be obtained. Since the gas flows out quickly and the crank pressure Pc in the crank chamber 16 can be quickly reduced, the capacity recovery at the time of start-up can be improved.
(2) During capacity operation, if the rotational speed of the rotary shaft 17 is high, the centrifugal force accompanying the rotation of the rotary shaft 17 increases, and the centrifugal force acting on the counterweight 55 of the on-off valve 50 increases. . Due to this centrifugal force, the on-off valve body 54 moves against the urging force of the spring 57 toward the axial center of the rotating shaft 17, abuts against the seat surface 51, and the on-off valve hole 53 is closed. Accordingly, the first bleed passage 48 provided with the on-off valve 50 is closed, and only the second bleed passage 58 provided with the throttle hole 59 is opened, so that the refrigerant from the crank chamber 16 to the suction chamber 38 is obtained. The amount of derived gas is reduced. As a result, the flow rate of the refrigerant gas used for the original purpose is increased by reducing the flow rate of the refrigerant gas circulated inside the compressor, so that the power and efficiency of the compressor can be reduced.
(3) When the rotation shaft 17 is at a high rotation speed, the first extraction passage 48 provided with the on-off valve 50 is closed, and only the second extraction passage 58 provided with the throttle hole 59 is open. Further, the amount of refrigerant gas derived from the crank chamber 16 to the suction chamber 38 is reduced, and the minimum capacity is further reduced particularly during the OFF operation, so that the power can be reduced. In addition, since the inertial force that acts on the piston 29 and the swash plate 23 increases at a high rotation speed, this can be compensated for even if the amount of refrigerant gas derived is reduced, and the capacity returnability at startup is prevented from being lowered. Can do.
(4) Since the opening / closing valve 50 may be provided in the first extraction passage 48 formed in the rotating shaft 17, the opening / closing operation of the opening / closing valve 50 can be performed using the centrifugal force generated by the rotation of the rotating shaft 17. . Further, since the second bleed passage is formed in the cylinder block 12 separately from the first bleed passage 48 and the throttle hole 59 is provided, the throttle hole 59 having a certain amount of gas outflow can be easily provided.
(5) By opening one end of the passage hole 45 formed in the rotating shaft 17 to the crank chamber 16 and providing the open / close valve 50 at the other end, the open / close valve 50 can be effectively arranged in the cylinder block 12. it can.
(6) The on-off valve 50 resists the urging force of the spring 57 by the on-off valve body 54, the spring 57 that urges the on-off valve body 54 toward the open position, and the centrifugal force that accompanies the rotation of the rotary shaft 17. And a counterweight 55 for moving the on-off valve body 54 to the closed position. Therefore, when the rotational speed of the rotary shaft 17 becomes high, the counterweight 55 is moved in the outer peripheral direction against the urging force of the spring 57 due to the centrifugal force acting on the counterweight 55, and the on-off valve body 54 is moved to the closed position. Moved. On the other hand, when the rotational speed of the rotating shaft 17 is low, the urging force of the spring 57 becomes dominant, so that the on-off valve body 54 is held at the open position. Thus, the structure of the on-off valve 50 is simple, and the first extraction passage 48 can be reliably opened and closed according to the number of rotations of the rotary shaft 17.

(Second Embodiment)
Next, a variable capacity swash plate compressor according to a second embodiment will be described with reference to FIG.
The compressor of this embodiment is provided with a function corresponding to the second extraction passage 58 of the first embodiment on the rotating shaft 17, and the other configurations are common.
Therefore, here, for convenience of explanation, some of the reference numerals used in the previous explanation are used in common, explanation of common configurations is omitted, and only the changed parts are explained.

In the compressor of this embodiment, as shown in FIG. 6, a throttle hole 70 communicating with the passage hole 45 on the front side (crank chamber 16 side) from the position where the on-off valve 50 on the rear end side of the rotary shaft 17 is provided. Are perforated in the radial direction. The aperture hole 70 corresponds to a fixed aperture. The passage hole 45 and the accommodation recess 44 communicate with each other through the throttle hole 70.
Here, if the diameter of the throttle hole 70 is d1, and the diameter of the communication hole 49 is d2, the throttle hole 70 is formed to satisfy d1 <d2.
In the first embodiment, the cross-sectional area of the communication hole 49 is Aa, the cross-sectional area of the throttle hole 59 is Ab, and the total cross-sectional area As1 at low rotation is As1 = Aa + Ab, and the total cross-sectional area at high rotation is As2 has been described as As2 = Ab, but in the present embodiment, d1 = Ab = As2,
d1 and d2 are set so that d2 = Aa + Ab = As1.

  When the rotational speed of the rotary shaft 17 is low, the centrifugal force associated with the rotation of the rotary shaft 17 is small, so that the open / close valve body 54 of the open / close valve 50 provided in the middle of the first extraction passage 48 is open / close valve hole. 53 is held open. Further, the rotary shaft 17 is provided with a throttle hole 70 that always communicates the crank chamber 16 and the suction chamber 38. The flow rate of the refrigerant gas in this case is determined by the passage cross-sectional area (diameter d2) of the communication hole 49. By the way, since there is a relationship of d1 <d2 between the diameter d2 of the communication hole 49 and the diameter d1 of the throttle hole 70, the outflow of the refrigerant gas from the crank chamber 16 to the suction chamber 38 passes through the housing recess 44. Since the process is promptly performed and the crank pressure Pc in the crank chamber 16 can be quickly reduced, it is possible to improve the capacity recoverability at the time of startup.

  Further, when the rotational speed of the rotary shaft 17 is high, the centrifugal force accompanying the rotation of the rotary shaft 17 increases, and the centrifugal force acting on the counterweight 55 of the on-off valve 50 increases. Due to this centrifugal force, the on-off valve body 54 moves against the urging force of the spring 57 toward the axial center of the rotating shaft 17, abuts against the seat surface 51, and the on-off valve hole 53 is closed. Therefore, the first extraction passage 48 provided with the on-off valve 50 is closed, and only the throttle hole 70 is open. In this case, the flow rate of the refrigerant gas is determined by the passage cross-sectional area (diameter d1) of the throttle hole 70. It is determined. Therefore, the amount of refrigerant gas discharged from the crank chamber 16 to the suction chamber 38 is reduced. However, since the inertial force acting on the piston 29 and the swash plate 23 becomes large at the time of high rotation, the displacement moves mainly due to the inertial force. Therefore, even if the amount of refrigerant gas derived is reduced, the capacity can be quickly restored at the time of startup. In addition, in this case, since the flow rate of the refrigerant gas circulated inside the compressor during capacity operation is reduced, the flow rate of the refrigerant gas used for the original purpose is increased. Can be planned. Further, the minimum capacity is reduced even during the OFF operation, and the power can be reduced. In addition, the on-off valve 50 shown in FIG. 6 represents the valve closing state.

  In this embodiment, since the first extraction passage 48 and the throttle hole 70 can be formed on the same rotation shaft 17, it is possible to reduce manufacturing man-hours and costs compared to the case where they are provided at different locations. is there.

(Third embodiment)
Next, a variable capacity swash plate compressor according to a third embodiment will be described with reference to FIGS.
In the compressor of this embodiment, the throttle hole 70 of the second embodiment is provided in the on-off valve 50, and other configurations are common.
Therefore, here, for convenience of explanation, some of the reference numerals used in the previous explanation are used in common, explanation of common configurations is omitted, and only the changed parts are explained.

In the compressor of this embodiment, as shown in FIG. 7, a groove 80 having a certain depth is formed at the inlet portion on the seat surface 51 side of the on-off valve hole 53 provided with the on-off valve 50. When a centrifugal force acts on the on-off valve 50 and the on-off valve body 54 contacts the seat surface 51, a groove hole 81 is formed by the on-off valve body 54 and the groove 80, and the passage hole 45 is formed through the groove hole 81. And the housing recess 44 communicate with each other. The slot 81 corresponds to a fixed throttle.
Here, the passage cross-sectional area of the slot 81 when the on-off valve body 54 contacts the seat surface 51 is set to be smaller than the passage cross-sectional area (diameter d2) of the communication hole 49, and the restriction in the second embodiment It is formed to be equivalent to the passage cross-sectional area (diameter d1) of the hole 70.

  When the rotational speed of the rotary shaft 17 is low, the centrifugal force associated with the rotation of the rotary shaft 17 is small, so that the open / close valve body 54 of the open / close valve 50 provided in the middle of the first extraction passage 48 is open / close valve hole. 53 is held open. Further, since the groove 81 is not formed, the flow rate of the refrigerant gas in this case is determined by the passage sectional area (diameter d2) of the communication hole 49. Accordingly, the refrigerant gas flows out from the crank chamber 16 to the suction chamber 38 quickly, and the crank pressure Pc in the crank chamber 16 can be quickly reduced, so that the capacity returnability at the time of startup can be improved.

  Further, when the rotational speed of the rotary shaft 17 is high, the centrifugal force accompanying the rotation of the rotary shaft 17 increases, and the centrifugal force acting on the counterweight 55 of the on-off valve 50 increases. Due to this centrifugal force, the on-off valve body 54 moves against the urging force of the spring 57 toward the axial center of the rotating shaft 17, abuts against the seat surface 51, and the on-off valve hole 53 is closed. At this time, only the groove hole 81 is opened, and the passage sectional area of the groove hole 81 is smaller than the passage sectional area of the communication hole 49, so that the amount of refrigerant gas led out from the crank chamber 16 to the suction chamber 38 is reduced. However, since the inertial force acting on the piston 29 and the swash plate 23 becomes large at the time of high rotation, the displacement moves mainly due to the inertial force. Therefore, even if the amount of refrigerant gas derived is reduced, the capacity can be quickly restored at the time of startup. In addition, in this case, since the flow rate of the refrigerant gas circulated inside the compressor during capacity operation is reduced, the flow rate of the refrigerant gas used for the original purpose is increased. Can be planned. Further, the minimum capacity is reduced even during the OFF operation, and the power can be reduced. In addition, the on-off valve 50 shown in FIG. 7 represents the valve closing state.

  In this embodiment, since it is only necessary to form the groove 80 in the opening / closing valve hole 53 in which the opening / closing valve 50 is provided, the configuration can be further simplified and the number of manufacturing steps and costs can be reduced.

The present invention is not limited to the first to third embodiments described above, and various modifications are possible within the scope of the gist of the invention. For example, the following modifications may be made.
In the second and third embodiments, the fixed throttle provided at the other end of the rotating shaft 17 has been described as the throttle hole 70 or the groove hole 81, but the plug body 60 that blocks the rear end portion of the passage hole 45. A fixed restrictor may be provided in this portion, and the passage hole 45 and the accommodating recess 44 may be in continuous communication.
In the third embodiment, the groove 80 is provided on the seating surface 51 side of the opening / closing valve hole 53, but a groove may be provided on the surface of the opening / closing valve body 54. In addition, a through-hole that allows the passage hole 45 and the housing recess 44 to communicate with each other may be provided inside the on-off valve body 54 to provide a fixed throttle.
In the first to third embodiments, the type of the refrigerant is not particularly specified, but the type of the refrigerant is not particularly limited. For example, it is preferable to use chlorofluorocarbon or carbon dioxide. The refrigerant may be gas or liquid.

It is a longitudinal section showing the whole compressor composition concerning a 1st embodiment. It is a sectional side view which expands and shows the on-off valve which concerns on 1st Embodiment. It is an important section expanded sectional view concerning a 1st embodiment. It is a block diagram which shows a 1st embodiment typically. It is a schematic diagram which shows the relationship between the rotation speed which concerns on 1st Embodiment, and a throttle hole total cross-sectional area. It is a principal part expanded sectional view concerning 2nd Embodiment. It is a principal part expanded sectional view which concerns on 3rd Embodiment. It is a D direction arrow directional view concerning a 3rd embodiment.

Explanation of symbols

10 Compressor 11 Housing 12 Cylinder block 12a Cylinder bore 16 Crank chamber 17 Rotating shaft 23 Swash plate 31 Compression chamber 35 Capacity control valve 38 Suction chamber 39 Discharge chamber 42 Air supply passage 48 First extraction passage 49 Communication hole 50 On-off valve 58 Second Extraction passage 59 Restriction hole (fixed restriction)

Claims (5)

A housing; a crank chamber defined in the housing; a rotating shaft rotatably supported in the crank chamber; a swash plate coupled to the rotating shaft so as to be integrally rotatable and tiltable; and the housing A piston accommodated in a cylinder bore formed in the cylinder bore so as to be reciprocally movable, and based on an opening adjustment of a capacity control valve provided in an air supply passage connecting the crank chamber and a discharge pressure region, In the variable displacement swash plate compressor that changes the inclination angle of the swash plate and controls the discharge capacity by changing the pressure,
A bleed passage that connects the crank chamber and the suction pressure region is provided, and the bleed passage has an open / close valve and a fixed throttle that are moved in a direction to close the bleed passage by a centrifugal force accompanying rotation of the rotary shaft. A variable capacity swash plate compressor characterized by The bleed passage has a first bleed passage formed in the rotating shaft and a second bleed passage formed in the housing, and an open / close valve is provided in the first bleed passage, and a fixed throttle is formed in the second bleed passage. The variable capacity swash plate compressor according to claim 1, wherein the compressor is provided. The variable capacity swash plate type according to claim 2, wherein one end side of the first bleed passage is opened to the crank chamber, and the other end side of the first bleed passage is provided with the on-off valve. Compressor. The bleed passage includes a passage formed at the center of the rotating shaft, one end side of the passage is opened to the crank chamber, and the opening / closing valve is disposed on the other end side of the passage. The variable capacity swash plate compressor according to claim 1, wherein the fixed throttle is formed on the other end side. The on-off valve includes a valve body, a biasing member that biases the valve body toward an open position, and the valve body against a biasing force of the biasing member due to a centrifugal force accompanying rotation of the rotating shaft. A variable capacity swash plate compressor according to any one of claims 1 to 4, further comprising a counterweight that moves the valve to a closed position.

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