JP2014163271A - Capacity control device and variable displacement swash plate compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a variable displacement swash plate compressor capable of performing more earlier return operation when liquid refrigerant stays in a crank chamber at starting, and to provide a capacity control device capable of actualizing the variable displacement swash plate compressor.SOLUTION: In the compressor, a differential pressure between a crank pressure Pc and a suction pressure Ps works on a piston 21. A discharge chamber 5b and a crank chamber 9 are communicated with each other via an air supply passage 40f (40a, 40c), the crank chamber 9 and a suction chamber 5a are communicated with each other via an extraction passage 40d, and the discharge chamber 5b and the suction chamber 5a are communicated with each other via a return passage 40g (40c, 40b). In a capacity control device 50, an air supply valve 71 is provided in the air supply passage 40f, and first and second valves 72, 73 are provided in the return passage 40g. The first and second return valves 72, 73 are opened when the suction pressure Ps exceeds a threshold value. Communication passages 65f, 65g reduce the pressure of refrigerant flowing in the return passage 40g when the first and second return valves 72. 73 are opened.

Description

  The present invention relates to a capacity control device and a variable capacity swash plate compressor.

  Conventionally, a variable capacity swash plate compressor (hereinafter simply referred to as a compressor) disclosed in Patent Document 1 is known. This compressor has a compressor body and a capacity control device.

  The compressor body includes a body housing. In the main body housing, a suction chamber, a discharge chamber, and a crank chamber are formed, and a plurality of cylinder bores are formed. A drive shaft is rotatably supported in the crank chamber. In the crank chamber, a swash plate is supported on the drive shaft so as to be integrally rotatable. The inclination angle of the swash plate can be changed. A piston is accommodated in each cylinder bore so as to be able to reciprocate to form a compression chamber. Each piston is connected to a swash plate via a pair of shoes, and the discharge capacity of the compression chamber changes with a stroke corresponding to the inclination angle of the swash plate.

  The capacity control device includes a valve housing fixed to the main body housing. The valve housing is formed with a control chamber communicating with the crank chamber, a high pressure passage communicating with the discharge chamber, and a low pressure passage communicating with the suction chamber. A bellows that is expanded and contracted by a suction pressure that is a pressure of the suction chamber is accommodated in the control chamber. The valve housing is provided with an air supply valve between the control chamber and the high pressure passage, and with first and second bleed valves between the control chamber and the low pressure passage. Furthermore, the control coil which can be excited or demagnetized is provided in the valve housing.

  In this capacity control device, when the control coil is excited, the supply valve is closed and the second extraction valve is opened. On the other hand, when the control coil is demagnetized, the supply valve is opened and the second extraction valve is closed. If the suction pressure increases beyond the threshold, the bellows contracts and the first bleed valve opens. On the other hand, if the suction pressure falls below the threshold value, the bellows expands and the first extraction valve closes.

  When the compressor is started, the control coil can be excited so that the supply valve is closed and the high-pressure refrigerant gas does not move from the discharge chamber to the crank chamber via the high-pressure passage and the control chamber. Here, when the operation stop state of the compressor has continued for a long time, liquid refrigerant that is liquid refrigerant may be accumulated in the crank chamber. In this case, the liquid refrigerant in the crank chamber flows into the control chamber of the capacity control device, and the bellows contracts. At this time, since the first bleed valve is opened due to the contraction of the bellows, and the second bleed valve is also opened due to the excitation of the control coil, the liquid refrigerant in the crank chamber passes through the control chamber and the low pressure passage. It is discharged into the suction chamber.

  For this reason, in this compressor, the crank pressure is reduced early, and the inclination angle of the swash plate is quickly shifted from the minimum value to the expansion direction. That is, in this compressor, even when the liquid refrigerant is accumulated in the crank chamber at the time of startup, the return operation is not hindered by the presence of the liquid refrigerant and can be returned early.

  Then, while the compressor is continuously operated with the control coil of the capacity control device being excited, the bellows is extended by the decrease in the crank pressure, and the first and second bleed valves are closed. Thereby, the bellows can detect the suction pressure which is the pressure of the suction chamber in the low pressure passage.

  For this reason, if the suction pressure decreases due to a decrease in the heat load, the air supply valve opens, and the high-pressure refrigerant gas moves from the discharge chamber to the crank chamber through the high-pressure passage and the control chamber. For this reason, in this compressor, the crank pressure increases and the inclination angle of the swash plate decreases. For this reason, the compressor has a small discharge capacity. On the other hand, if the suction pressure increases due to an increase in heat load, the air supply valve is closed, and the high-pressure refrigerant gas in the discharge chamber is difficult to move into the crank chamber. For this reason, in this compressor, the crank pressure decreases and the inclination angle of the swash plate increases. For this reason, the compressor has a large discharge capacity. Thus, in this compressor, the operation is continued with the discharge capacity corresponding to the heat load.

  Further, when the control coil of the capacity control device is demagnetized, the supply valve is opened and the second extraction valve is closed. Thereby, the high-pressure refrigerant gas in the discharge chamber moves into the crank chamber in a short time. For this reason, in this compressor, the crank pressure rises rapidly, and the inclination angle of the swash plate is quickly minimized. This minimizes the discharge capacity of the compressor. Thus, with this compressor, the load on the vehicle can be quickly reduced when the vehicle is accelerated.

Japanese Patent No. 4861956

  However, in a variable displacement swash plate compressor, it is desired to further speed up the return operation when liquid refrigerant is accumulated in the crank chamber at the time of startup.

  The present invention has been made in view of the above-described conventional situation, and is a variable displacement swash plate compressor capable of further speeding up the return operation when liquid refrigerant is accumulated in the crank chamber at the time of startup. It is an object to be solved to provide a capacity control device capable of realizing the variable capacity swash plate compressor.

The variable displacement swash plate compressor of the present invention includes a main body housing in which a suction chamber, a discharge chamber, a crank chamber and a cylinder bore are formed, a drive shaft rotatably supported in the crank chamber, and the drive in the crank chamber A swash plate that is supported by the shaft so as to be integrally rotatable and is capable of changing the inclination angle; and a piston that is reciprocally accommodated in the cylinder bore to form a compression chamber;
A differential pressure between a crank pressure that is a pressure of the crank chamber and a suction pressure that is a pressure of the suction chamber acts on the piston during a suction stroke,
The discharge chamber and the crank chamber communicate with each other through an air supply passage;
The crank chamber and the suction chamber communicate with each other through an extraction passage;
The discharge chamber and the suction chamber communicate with each other through a return passage;
At least one of the supply passage and the extraction passage is provided with a pressure regulating valve that changes the crank pressure by adjusting a passage opening degree,
The return passage includes a return valve that opens and closes the return passage and opens when the suction pressure exceeds a threshold value, and a throttle that reduces the pressure of the refrigerant flowing through the return passage when the return valve is opened. It is provided (Claim 1).

  The inventors of the present invention, in a variable capacity swash plate compressor (hereinafter simply referred to as a compressor), the reason why the inclination angle of the swash plate does not easily shift from the minimum value to the enlargement direction, that is, the reason why the swash plate is difficult to return, The first is that the moment in the return direction is small, and the second is that the friction is large. Conventionally, (1) the biasing force of the spring that biases the swash plate opposite to the return direction is large, (2) the inertial force of the piston and the pair of shoes is small, 3) In addition to the small inertial product in the return direction of the swash plate, (4) the difference between the crank pressure, which is the crank chamber pressure during the discharge stroke, and the discharge pressure, which is the pressure in the discharge chamber, for each piston. Since the pressure acts, it was considered that the difference between the crank pressure and the discharge pressure is small. Regarding the differential pressure of (4), if the discharge pressure before return is low, the crank pressure must be lowered. The conventional capacity control device including the capacity control device of Patent Document 1 focuses on rapidly reducing the crank pressure at the time of return.

  However, a differential pressure between the crank pressure and the suction pressure, which is the pressure in the suction chamber, acts on each piston during the suction stroke. For this reason, the first cause should be influenced by (5) a large differential pressure between the crank pressure acting on each piston during the suction stroke and the suction pressure. Regarding the differential pressure of (5), in addition to lowering the crank pressure, means for increasing the suction pressure acting on each piston at the time of return can be established. Thus, the compressor and the capacity control device of the present invention pay attention to increasing the suction pressure acting on each piston when the swash plate is restored.

  In the compressor according to the present invention, the discharge chamber and the suction chamber communicate with each other through the return passage, the return passage is provided with the return valve, and the throttle for reducing the pressure of the refrigerant flowing through the return passage when the return valve is opened. Yes. The return valve opens when the suction pressure exceeds a threshold value, and supplies the refrigerant gas having a high discharge pressure in the discharge chamber to the suction chamber through the throttle. For this reason, the suction pressure acting on each piston at the time of return is higher than in the prior art, and the differential pressure between the crank pressure acting on each piston in the suction stroke and the suction pressure is reduced. For this reason, the inclination angle of the swash plate quickly shifts from the minimum value to the enlargement direction. As a result, in this compressor, even if the liquid refrigerant is accumulated in the crank chamber at the time of startup, the return operation is not hindered by the presence of the liquid refrigerant and can be returned early.

  Therefore, this compressor can further speed up the return operation when the liquid refrigerant is accumulated in the crank chamber at the time of startup.

  If the suction pressure falls below the threshold value, the return valve closes due to the presence of the throttle, and refrigerant gas at a high discharge pressure in the discharge chamber is not supplied to the suction chamber. In the compressor of the present invention, the discharge chamber and the crank chamber communicate with each other through the air supply passage, and the crank chamber and the suction chamber communicate with each other through the extraction passage. At least one of the air supply passage and the extraction passage is provided with a pressure regulating valve that adjusts the passage opening degree. For this reason, the compressor can adjust the crank pressure by adjusting the opening of the passage by the pressure regulating valve, and can adjust the discharge capacity by changing the inclination angle of the swash plate.

  Whether the suction pressure exceeds the threshold value or falls below the threshold value can be based on, for example, a detection unit that detects the suction pressure and transmits a signal, or a pressure-sensitive unit that detects and displaces the suction pressure.

  The pressure regulating valve that adjusts the passage opening of the air supply passage is referred to as an air supply valve, and the pressure regulating valve that adjusts the passage opening of the extraction passage can be referred to as an extraction valve. Further, the pressure regulating valve that adjusts the opening degree of the supply passage and the extraction passage can be referred to as a three-way valve.

  The pressure regulating valve is preferably an air supply valve provided in the air supply passage. Further, it is preferable that an extraction throttle is provided in the extraction passage.

  In this case, the air supply valve increases the passage opening of the air supply passage so that the crank pressure can be increased quickly and the discharge capacity can be increased more quickly than the extraction valve provided in the extraction passage reduces the passage opening. Can be made smaller. Further, since the extraction throttle secures the opening degree of the extraction passage, the crank pressure is not excessively increased, and excellent durability is exhibited.

  The compressor of the present invention is preferably provided with a capacity control device that is integrally provided with an air supply passage, a return passage, an air supply valve, and a return valve.

  In this compressor, the compressor main body and the capacity control device are separated. For this reason, it becomes possible to handle the capacity control device as a single unit such as commercially available or purchased. Furthermore, since the compressor of the present invention functions by attaching a capacity control device to the compressor body, the compressor of the present invention can be easily manufactured.

  The return valve is preferably opened when the variable displacement swash plate compressor is started. In this case, for example, the compressor of the present invention has an operational effect based on the determination based on the start-up of the vehicle, the input of the air-conditioner, or the like in addition to the detection means and the pressure-sensitive means.

  The capacity control device may be formed with a pressure sensitive passage communicating with the crank chamber, a high pressure passage communicating with the discharge chamber, and a low pressure passage communicating with the suction chamber. The capacity control device includes a control coil that can be excited or demagnetized, a first valve body that is opened and closed by receiving the suction pressure of the suction chamber, and that opens when the suction pressure exceeds a threshold value; A first valve seat that contacts and separates the valve body, a second valve body that operates by excitation of the control coil, and a second valve seat that contacts and separates the second valve body may be provided. The return passage may be constituted by a high pressure passage and a low pressure passage. The first valve body and the first valve seat may be disposed between the high pressure passage and the low pressure passage to constitute a return valve. The air supply passage may be constituted by a pressure sensitive passage and a high pressure passage. The second valve body and the second valve seat may be disposed between the pressure-sensitive passage and the high-pressure passage to constitute an air supply valve.

  In this case, if the suction pressure decreases due to a decrease in the thermal load, the air supply valve opens, and the high-pressure refrigerant gas moves from the discharge chamber to the crank chamber through the high-pressure passage and the control chamber. For this reason, in this compressor, the crank pressure increases and the inclination angle of the swash plate decreases. For this reason, the compressor has a small discharge capacity. On the other hand, if the suction pressure increases due to an increase in heat load, the air supply valve is closed, and the high-pressure refrigerant gas in the discharge chamber is difficult to move into the crank chamber. For this reason, in this compressor, the crank pressure decreases and the inclination angle of the swash plate increases. For this reason, the compressor has a large discharge capacity. Thus, in this compressor, the operation is continued with the discharge capacity corresponding to the heat load.

  In this case, the air supply valve is opened by exciting or demagnetizing the control coil. Thereby, the high-pressure refrigerant gas in the discharge chamber moves into the crank chamber in a short time. For this reason, in this compressor, the crank pressure rises rapidly, and the inclination angle of the swash plate is quickly minimized. This minimizes the discharge capacity of the compressor. Thus, with this compressor, the load on the vehicle can be quickly reduced when the vehicle is accelerated.

  The capacity control device may be provided with a third valve body that operates by excitation of a control coil, and a third valve seat with which the third valve body contacts and separates. The third valve body and the third valve seat may be disposed between the high pressure passage and the low pressure passage. The return valve may be composed of a first return valve constituted by a first valve body and a first valve seat, and a second return valve constituted by a third valve body and a third valve seat. The third valve body can be urged in the valve opening direction by the excitation of the control coil.

  In this case, the return valve has the second return valve in addition to the first return valve, and the effects of the present invention are more reliably produced.

  In the capacity control device, a detection passage communicating with the suction chamber may be defined from the low pressure passage. The first valve body can be opened when the suction pressure in the detection passage becomes higher than a threshold value (Claim 7).

  In this case, the suction pressure acts on the crank pressure by the detection passage. For this reason, the displacement of the first valve body is stabilized, and the effects of the present invention are more reliably generated.

The capacity control device of the present invention includes a main body housing in which a suction chamber, a discharge chamber, a crank chamber, and a cylinder bore are formed, a drive shaft that is rotatably supported in the crank chamber, and an integral rotation on the drive shaft in the crank chamber. A swash plate that is supported in such a manner that the tilt angle can be changed, and a piston that is accommodated in the cylinder bore so as to reciprocate and forms a compression chamber,
A differential pressure between a crank pressure that is a pressure of the crank chamber and a suction pressure that is a pressure of the suction chamber acts on the piston during a suction stroke,
The discharge chamber and the crank chamber communicate with each other through an air supply passage, the crank chamber and the suction chamber communicate with each other through an extraction passage, and the discharge chamber and the suction chamber communicate with each other through a return passage,
A capacity control device used in a variable capacity compressor that controls the discharge capacity by changing the pressure in the crank chamber,
The air supply passage;
The extraction passage;
The return path;
An air supply valve for adjusting a passage opening of the air supply passage;
An extraction throttle for restricting the extraction passage;
A return valve for adjusting the opening of the return passage;
A throttle for reducing the pressure of the refrigerant flowing through the return passage when the return valve is opened is provided (Claim 8).

  When the capacity control device of the present invention is assembled to the compressor body, the compressor exhibits the effects of the present invention.

  The compressor according to the present invention can further speed up the return operation when liquid refrigerant is accumulated in the crank chamber at the time of startup. Further, the capacity control apparatus of the present invention can realize this compressor.

It is sectional drawing of the compressor of Example 1. FIG. 1 is a schematic structural diagram of a compressor of Example 1. FIG. It is explanatory drawing of the piston in the compressor of Example 1. FIG. 1 is a cross-sectional view of a capacity control device according to a first embodiment. 1 is an enlarged cross-sectional view of a capacity control device according to a first embodiment. It is explanatory drawing of a load in connection with the capacity | capacitance control apparatus of Example 1. FIG. FIG. 3 is a cross-sectional view of the capacity control device according to the first embodiment at the time of startup. FIG. 4 is a cross-sectional view of the capacity control device according to the first embodiment during normal operation. FIG. 4 is a cross-sectional view of the capacity control device according to the first embodiment during OFF operation. 6 is a cross-sectional view of a capacity control device according to Embodiment 2. FIG. FIG. 6 is an enlarged cross-sectional view of a capacity control device according to a second embodiment. FIG. 6 is a cross-sectional view of a capacity control device according to a second embodiment at the time of startup. FIG. 6 is a cross-sectional view of a capacity control device of Example 2 during normal operation. FIG. 6 is a cross-sectional view of the capacity control device of Example 2 during OFF operation.

  Embodiments 1 and 2 embodying the present invention will be described below with reference to the drawings.

Example 1
A variable capacity swash plate compressor (hereinafter referred to as a compressor) according to the first embodiment includes a compressor body 10 and a capacity controller 50 as shown in FIG.

  In the compressor body 10, a plurality of cylinder bores 1 a are concentrically formed in the cylinder block 1 in parallel at equal angular intervals. The cylinder block 1 is sandwiched between a front housing 3 positioned at the front and a rear housing 5 positioned at the rear, and is fastened by a plurality of bolts 7 in this state. A crank chamber 9 is formed inside the cylinder block 1 and the front housing 3. The rear housing 5 is formed with a suction chamber 5a and a discharge chamber 5b.

  A shaft hole 3 a is formed in the front housing 3, and a shaft hole 1 b is formed in the cylinder block 1. A drive shaft 11 is rotatably supported in the shaft holes 3a and 1b via a shaft seal device 9a and radial bearings 9b and 9c. A pulley or electromagnetic clutch (not shown) is provided on the drive shaft 11, and a belt (not shown) driven by a vehicle engine or motor is wound around the pulley or electromagnetic clutch.

  In the crank chamber 9, a lug plate 13 is press-fitted into the drive shaft 11, and a thrust bearing 15 is provided between the lug plate 13 and the front housing 3. A swash plate 17 is inserted through the drive shaft 11. The lug plate 13 and the swash plate 17 are connected by a link mechanism 19 that supports the swash plate 17 so that the inclination angle can be changed.

  A piston 21 is housed in each cylinder bore 1a so as to be able to reciprocate. A valve unit 23 is provided between the cylinder block 1 and the rear housing 5. The compressor valve unit 23 includes a suction valve plate 25, a valve plate 27, a discharge valve plate 29, and a retainer plate 31. The valve plate 27 is provided with a suction port 23a and a discharge port 23b. The cylinder block 1, the front housing 3, the rear housing 5, and the valve unit 23 are examples of the main body housing of the present invention.

  The suction valve plate 25 is formed with a suction lead portion 25a capable of opening and closing the suction port 23a by elastic deformation and a discharge port 25b communicating with the discharge port 23b. The discharge valve plate 29 is formed with a discharge lead portion 29a capable of opening and closing the discharge ports 23b and 25b by elastic deformation.

  Between the swash plate 17 and each piston 21, shoes 33a and 33b that are paired in the front and rear are provided, and the swinging motion of the swash plate 17 is caused to reciprocate by each pair of shoes 33a and 33b. It is supposed to be converted. Each compression chamber 24 is formed by the cylinder bore 1 a, the piston 21 and the valve unit 23.

  A control valve chamber 5c is formed in the rear housing 5, and the crank chamber 9 and the control valve chamber 5c are connected by a first passage 40a. The control valve chamber 5c and the suction chamber 5a are connected by a second passage 40b, and the control valve chamber 5c and the discharge chamber 5b are connected by a third passage 40c. A capacity control device 50 is provided in the control valve chamber 5c. The crank chamber 9 and the suction chamber 5a communicate with each other through an extraction passage 40d. As shown in FIG. 2, an extraction throttle 40e is formed in the extraction passage 40d. The first passage 40a and the third passage 40c correspond to an air supply passage 40f that connects the crank chamber 9 and the discharge chamber 5b. The third passage 40c and the second passage 40b correspond to a return passage 40g that connects the discharge chamber 5b and the suction chamber 5a.

  As shown in FIG. 4, in the capacity control device 50, a recess 51 a is formed at the tip of the first housing 51. The concave portion 51 a has a pressure-sensitive chamber 53 inside by fixing a lid member 54 a of a bellows 54 as a pressure-sensitive body to the tip side. The bellows 54 includes a lid member 54a, a seat member 54b facing the lid member 54a, and a bellows 54c attached between the lid member 54a and the seat member 54b. The bellows 54c is evacuated. The seat member 54b has a stopper portion 54d that protrudes toward the lid member 54a in the bellows 54c. Further, a stopper member 54e that protrudes toward the stopper portion 54d within the bellows 54c is fixed to the lid member 54a. In the bellows 54c, a spring 54f having a biasing force is provided between the stopper member 54e and the seat member 54b in a direction in which the stopper member 54e and the seat member 54b are separated from each other.

  The first housing 51 is formed with a pressure-sensitive hole 51 b that allows communication between the outside and the pressure-sensitive chamber 53. The first housing 51 is covered with a cylindrical filter 52 for removing foreign substances. Therefore, the crank pressure Pc, which is the pressure of the crank chamber 9, is introduced into the pressure sensitive chamber 53 through the first passage 40a and the pressure sensitive hole 51b. The pressure sensitive hole 51b corresponds to a pressure sensitive passage.

  The first housing 51 is formed with a high-pressure hole 51c and a low-pressure hole 51d that extend in the radial direction. The high pressure hole 51c corresponds to a high pressure passage. The high-pressure hole 51c communicates with the third passage 40c. For this reason, the discharge pressure Pd which is the pressure of the discharge chamber 5b is introduced into the high-pressure hole 51c through the third passage 40c. The low pressure hole 51d corresponds to a low pressure passage. The low pressure hole 51d communicates with the second passage 40b. For this reason, the suction pressure Ps which is the pressure of the suction chamber 5a is introduced into the low pressure hole 51d through the second passage 40b. The suction pressure Ps is the pressure in the suction chamber 5a, not the outlet pressure of the evaporator upstream from the suction chamber 5a.

  The first housing 51 is formed with a first shaft hole 51e extending in the axial direction and having a tip communicating with the pressure-sensitive chamber 53 and intersecting the high-pressure hole 51c. The first housing 51 is formed with a second shaft hole 51f that communicates with the first shaft hole 51e, extends in the axial direction, and intersects the low-pressure hole 51d. As shown in FIG. 5, a second valve seat 71a having a slightly smaller diameter is formed between the pressure sensing chamber 53 and the first shaft hole 51e. A third valve seat 73a having a slightly smaller diameter than the first shaft hole 51e is formed between the first shaft hole 51e and the second shaft hole 51f.

  As shown in FIG. 4, a fixed iron core 55, a guide 56, and a second housing 57 are fixed to the rear end of the first housing 51. A movable iron core 58 is provided in the guide 56 so as to be movable in the axial direction, and a control spring 59 is provided between the fixed iron core 55 and the movable iron core 58. Shaft holes 58 a and 55 a are also formed in the movable iron core 58 and the fixed iron core 55, and the rear end of the first rod 60 extending in the axial direction is press-fitted into the shaft hole 58 a of the movable iron core 58. The first rod 60 is slidably inserted through the shaft hole 55a of the fixed iron core 55.

  A control coil 62 is fixed around the guide 56. A connector 63 is fixed behind the control coil 62. A cover 64 is provided around the control coil 62 and around a part of the connector 63. In the connector 62, lead wires (not shown) each having a tip connected to the control coil 62 are provided. The first housing 51, the second housing 57, the filter 52, the cover 64, and the connector 62 are examples of the valve housing of the present invention.

  A second rod 61 coaxial with the first rod 60 is provided at the tip of the first rod 60 with a gap therebetween. As shown in FIG. 5, the second rod 61 is located on the rear end side and has the same diameter as the first rod 60, and on the front end side, the second rod 61 is slightly larger in diameter than the first rod 60. 2 part 61d and it is located between the 1st part 61c and the 2nd part 61d, and consists of the small diameter part 61b smaller in diameter than the 1st rod 60. The second portion 61d is fixed to the seat member 54b of the bellows 54. The second rod 61 corresponds to the first valve body.

  A cylindrical spool 65 is press-fitted into the tip of the first rod 60, and the first portion 61 c of the second rod 61 can slide within the spool 65. The first rod 60 and the spool 65 correspond to a second valve body that moves integrally.

  The spool 65 is integrated with the large-diameter portion 65a slidable in the first shaft hole 51e and the large-diameter portion 65a on the rear side, and has a medium-diameter portion 65h slightly smaller in diameter than the large-diameter portion 65a and on the rear side. It is integrated with the medium diameter part 65h and has a small diameter part 65b slightly smaller in diameter than the medium diameter part 65h. The small diameter portion 65 b is located between the front end surface 60 a of the first rod 60 and the rear end surface 61 a of the first portion 61 c in the second rod 61. The small diameter portion 65b is movable in the third valve seat 73a.

  The large diameter portion 65 a of the spool 65 is formed with a first hole 65 c extending in the radial direction and communicating or not communicating with the high pressure hole 51 c of the first housing 51 and the small diameter portion 61 b of the second rod 61. In addition, the middle diameter portion 65h is formed with a second hole 65d that is located behind the first hole 65c and extends in the radial direction and communicates with the small diameter portion 61b. Further, a third hole 65e communicating with the front end surface 60a and the rear end surface 61a is formed in the small diameter portion 65b.

  The medium diameter portion 65h and the small diameter portion 65b have communication passages 65f and 65g with respect to the first shaft hole 51e and the third valve seat 73a. These communication passages 65f and 65g allow the second hole 65d to communicate with the second shaft hole 51f. The communication paths 65f and 65g correspond to throttles that reduce the pressure of the refrigerant.

  In this capacity control device 50, the second valve seat 71a and the tip 71b of the large-diameter portion 65a of the spool 65, which is a part of the second valve body, serve as a pressure regulating valve that adjusts the passage opening of the air supply passage 40f. The air supply valve 71 is configured.

  The middle diameter portion 65h side of the first hole 65c of the large diameter portion 65a of the spool 65 is a first valve seat 72a. The first return valve 72 that adjusts the opening degree of the return passage 40g is configured by the first valve seat 72a and the tip 72b of the second portion 61d of the second rod 61 that is the first valve body. ing.

  Further, the third valve seat 73a of the first housing 51 and the boundary passage 73b of the spool 65 which is a part of the second valve body and the boundary 73b of the communication passage 65g adjust the passage opening degree of the return passage 40g. A 2 return valve 73 is configured.

  Here, the biasing force of the spring 54f of the bellows 54 shown in FIG. 4 is Fb1, the biasing force of the control spring 59 is Fb2, and the pressure receiving area of the bellows 54 in the pressure sensing chamber 53 is Sb, as shown in FIG. The cross-sectional area of the second portion 61d of the rod 61 is S1, and the cross-sectional area of the small diameter portion 61b of the second rod 61 is S3. Further, the area based on the radius of the outer periphery of the large diameter portion 65a in the spool 65 is S2, and the area of the rear end surface 61a of the first portion 61c of the second rod 61 is S4. Furthermore, the biasing force that biases the first rod 60 when the control coil 62 is excited is Fφ.

In this case, the load acting on the bellows 54 with the first and second return valves 72 and 73 opened is
Fb1 = Pc (Sb−S1) + Pd (S1−S3) −Pd (S4−S3) + PsS4
= Pc (Sb-S1) + Pd (S1-S4) + PsS4
It is.

If S1≈S4 or S1 = S4,
Fb1 = Pc (Sb−S1) + PsS4
Is established.

  That is, the first and second return valves 72 and 73 are not affected by the discharge pressure Pd, and when the crank pressure Pc and the suction pressure Ps are lowered, the opening degree of the return passage 40g is reduced and the normal operation state is established.

The load acting on the first rod 60 and the spool 65 in the state where the first return valve 72 is closed is
Fb1 + Fb2 = Pc (Sb−S1) −Pc (S2−S1) + PsS2 + Fφ
It is.

If Sb = S2 is set,
Fb1 + Fb2-PsS4 = Fφ
Is established.

  That is, in the normal operation state in which the first return valve 72 is closed, the capacity control device 50 can control the suction pressure Ps by the value of the current supplied to the control coil 62.

  Although not shown, a condenser is connected to the discharge chamber 5b of the compressor shown in FIG. 1 via a check valve, the condenser is connected to the expansion valve, the expansion valve is connected to the evaporator, An evaporator is connected to the suction chamber 5a of the compressor. These compressors, condensers, expansion valves, and evaporators constitute an air conditioner that is mounted on a vehicle and performs air conditioning in the passenger compartment.

  In the compressor configured as described above, when the drive shaft 11 is rotationally driven, the lug plate 13 and the swash plate 17 rotate synchronously with the drive shaft 11, and each stroke is performed according to the inclination angle of the swash plate 17. The piston 21 reciprocates in each cylinder bore 1a. For this reason, the refrigerant in the suction chamber 5a is sucked into the compression chambers 24, compressed, and discharged into the discharge chamber 5b. During this time, a differential pressure between the crank pressure Pc and the discharge pressure Pd acts on each piston 21 during the discharge stroke, as shown in FIG. Further, a differential pressure between the crank pressure Pc and the suction pressure Ps acts on each piston 21 during the suction stroke.

  As shown in FIGS. 7 to 9, the capacity control device 50 adjusts the air supply valve 71 and the first and second return valves 72 and 73 according to the suction pressure Ps and the crank pressure Pc, so that the compressor main body 10 is adjusted. Control.

  That is, when the compressor has been shut down for a long time and liquid refrigerant has accumulated in the crank chamber 9, as shown in FIG. 7, the pressure sensitive chamber 53 has a high pressure due to the liquid refrigerant in the crank chamber 9. A crank pressure Pc is introduced. The suction pressure Ps acts on the rear end surface 61a of the second rod 61. For this reason, the bellows 54 is reduced until the stopper portion 54d contacts the stopper member 54e. For this reason, the 2nd rod 61 moves ahead.

  On the other hand, the control coil 62 shown in FIG. 4 is excited, and the movable iron core 58 approaches the fixed iron core 55. For this reason, as shown in FIG. 7, the 1st rod 60 and the spool 65 have moved to the front end side. For this reason, the front-end | tip part 71b of the spool 65 moves to a front end side, and is seated on the 2nd valve seat 71a, and the air supply valve 71 closes. For this reason, the first passage 40a and the third passage 40c do not communicate with each other, and the air supply passage 40f is closed.

  Further, with the movement of the second rod 61 accompanying the reduction of the bellows 54 and the movement of the first rod 60 and the spool 65 toward the distal end side, the distal end portion 72b of the second rod 61 is separated from the first valve seat 72a. . For this reason, the first hole 65c of the large diameter portion 65a of the spool 65 and the small diameter portion 61b of the second rod 61 communicate with each other, and the first return valve 72 opens the inlet of the return passage 40g. As the first rod 60 and the spool 65 move toward the distal end side, the boundary 73b of the spool 65 moves away from the third valve seat 73a. For this reason, the second hole 65d communicates with the second shaft hole 51f, and the second return valve 73 opens the outlet of the return passage 40g.

  Therefore, the third passage 40c, the high pressure hole 51c, the first hole 65c, the small diameter portion 61b, the second hole 65d, the first shaft hole 51e, the communication passages 65f and 65g, the second shaft hole 51f, the low pressure hole 51d, and the second Through the passages 40b, the refrigerant having the discharge pressure Pd is introduced into the suction chamber 5a at a pressure lower than the discharge pressure Pd through the communication passages 65f and 65g, which are throttled, so that the suction pressure Ps in the suction chamber 5a is lower than the conventional pressure. Become higher.

  For this reason, the differential pressure Pc−Ps acting on each piston 21 during the suction stroke is reduced. For this reason, the inclination angle of the swash plate 17 quickly shifts from the minimum value to the enlargement direction. As a result, in this compressor, even when the liquid refrigerant is accumulated in the crank chamber 9 at the time of startup, the return operation is not hindered by the presence of the liquid refrigerant and can be returned early. .

  Further, in the state where the control coil 62 shown in FIG. 4 is excited, if the liquid refrigerant in the crank chamber 9 is less than a certain amount, the crank pressure Pc is lowered and the suction pressure Ps is lowered from the set pressure. As shown in FIG. 8, the bellows 54 is extended by the biasing force of the spring 54f. For this reason, the 2nd rod 61 moves back, and the front-end | tip part 72b of the 2nd rod 61 seats on the 1st valve seat 72a. For this reason, the first hole 65c of the large-diameter portion 65a of the spool 65 and the small-diameter portion 61b of the second rod 61 are disconnected, the first return valve 72 is closed, and the inlet of the return passage 40g is closed. The third valve seat 73a of the first housing 51 and the communication passages 65f and 65g of the spool 65 are in communication with each other, and the second return valve 73 keeps the outlet of the return passage 40g open.

  At this time, since the control coil 62 shown in FIG. 4 is excited, the suction pressure Ps acts on the pressure receiving area S2 of the first rod 60 and the spool 65 shown in FIG. 6, and the first rod 60 and the spool 65 become the suction pressure. Displaces according to Ps. For this reason, if the suction pressure Ps changes due to the magnitude of the thermal load, the opening degree of the passage between the tip 71b of the spool 65 and the second valve seat 71a is displaced, and the intake valve 71 opens the passage of the supply passage 40f. Adjust the degree. In the state shown in FIG. 8 in which the distal end portion 72b of the second rod 61 is seated on the first valve seat 72a and the first return valve 72 is closed, the crank pressure Pc acts on the bellows 54 and the spool 65. , Sb and S2 are set equal to each other, the action on the bellows 54 and the spool 65 is canceled out.

  For this reason, when the air supply valve 71 opens the air supply passage 40 f, a high discharge pressure Pd is appropriately introduced into the crank chamber 9. If the crank pressure Pc increases, the differential pressure Pc-Ps acting on each piston 21 during the intake stroke increases, and the differential pressure Pd-Pc acting on each piston 21 during the discharge stroke decreases. For this reason, the inclination angle of the swash plate 17 becomes small, the stroke of each piston 21 becomes short, and the discharge capacity per one rotation of the drive shaft 11 becomes small.

  Further, when the air supply valve 71 closes the air supply passage 40f, the high discharge pressure Pd is not appropriately introduced into the crank chamber 9. If the crank pressure Pc decreases, the differential pressure Pc-Ps acting on each piston 21 during the intake stroke is reduced, and the differential pressure Pd-Pc acting on each piston 21 during the discharge stroke increases. For this reason, the inclination angle of the swash plate 17 is increased, the stroke of each piston 21 is increased, and the discharge capacity per one rotation of the drive shaft 11 is increased.

  The crank pressure Pc is also increased by the high-pressure blow-by gas that leaks into the crank chamber 9 from the gap between the cylinder bore 1a and the piston 21 shown in FIG. Further, the crank pressure Pc is guided to the suction chamber 5a through the extraction passage 40d provided with the extraction throttle 40e, and does not become excessively high.

  On the other hand, if the control coil 62 shown in FIG. 4 is demagnetized, the movable core 58 is separated from the fixed core 55 by the biasing force of the spring 59 regardless of the expansion / contraction of the bellows 54, and the first rod 60 and the spool 65 are moved rearward. Move in a short time. For this reason, as shown in FIG. 9, the tip 71b of the spool 65 quickly moves to the rear side of the second valve seat 71a, and the air supply valve 71 quickly increases the passage opening degree of the air supply passage 40f. . For this reason, the discharge chamber 5b and the crank chamber 9 communicate quickly. Thereby, the high-pressure refrigerant gas in the discharge chamber 5b moves into the crank chamber 9 in a short time.

  Further, since the high discharge pressure Pd is introduced into the pressure sensitive chamber 53, the bellows 54 is reduced until the stopper portion 54d contacts the stopper member 54e. For this reason, the 2nd rod 61 moves ahead.

  On the other hand, since the first rod 60 and the spool 65 are moved rearward, the boundary 73b of the spool 65 is seated on the second valve seat 73a, and the second hole 65d and the second shaft hole 51f are disconnected. The exit of the return passage 40g is closed.

  For this reason, in this compressor, the crank pressure Pc rises rapidly, and the inclination angle of the swash plate 17 is quickly minimized. This minimizes the discharge capacity of the compressor. Thus, with this compressor, the load on the vehicle can be quickly reduced when the vehicle is accelerated.

  Therefore, this compressor can further speed up the return operation when liquid refrigerant is accumulated in the crank chamber 9 at the time of startup.

  Further, in this compressor, the supply valve 71 can adjust the crank pressure Pc by adjusting the passage opening degree of the supply passage 40c, and can adjust the discharge capacity by changing the inclination angle of the swash plate 17. It is. For this reason, the operation is continued with the discharge capacity corresponding to the heat load. At this time, the supply valve 71 increases the passage opening degree of the supply passage 40c, so that the crank pressure Pc can be increased rapidly and the discharge capacity can be decreased rapidly. Further, since the bleed throttle 40e secures the passage opening degree of the bleed passage 40d, the crank pressure Pc does not become excessively high, and excellent durability is exhibited.

  Moreover, since this compressor consists of the compressor main body 10 and the capacity | capacitance control apparatus 50, it is possible to purchase the capacity | capacitance control apparatus 50 independently. Furthermore, since the compressor functions by attaching the capacity control device 50 to the compressor body 10, the compressor can be easily manufactured.

(Example 2)
The compressor of the second embodiment employs a capacity control device 80 shown in FIG. In the capacity control device 80, a high pressure hole 81a, a low pressure hole 81b, and a pressure detection hole 81c extending in the radial direction are formed in the first housing 81, respectively. The high pressure hole 81a corresponds to a high pressure passage. The high-pressure hole 81a communicates with the third passage 40c. For this reason, the discharge pressure Pd that is the pressure of the discharge chamber 5b is introduced into the high-pressure hole 81a through the third passage 40c. The low pressure hole 81b corresponds to a low pressure passage. The low pressure hole 81b communicates with the second passage 40b. For this reason, the suction pressure Ps which is the pressure of the suction chamber 5a is introduced into the low pressure hole 81b through the second passage 40b. Further, the pressure detection hole 81c corresponds to a detection passage. The pressure detection hole 81c communicates with a third passage 40h that connects the control valve chamber 5c and the suction chamber 5a separately from the second passage 40b. For this reason, the suction pressure Ps ′, which is the pressure of the suction chamber 5a, is also introduced into the pressure detection hole 81c through the third passage 40h.

  The first housing 81 is formed with a first shaft hole 81d extending in the axial direction and having a tip communicating with the pressure sensing chamber 53 and intersecting the high pressure hole 81a. The first housing 81 has a second shaft hole 81e that communicates with the first shaft hole 81d and extends in the axial direction and intersects the low-pressure hole 81b. As shown in FIG. 11, a second valve seat 91a having a slightly smaller diameter than the first shaft hole 81d is formed between the pressure sensing chamber 53 and the first shaft hole 81d. A third valve seat 93a having a slightly smaller diameter than the first shaft hole 81d is formed between the first shaft hole 81d and the second shaft hole 81e. Further, the first housing 81 is formed with a third shaft hole 81f that communicates with the second shaft hole 81e, extends in the axial direction, and intersects the pressure detection hole 81c.

  As shown in FIG. 10, a second rod 83 coaxial with the first rod 60 is provided at the tip of the first rod 60 with a gap therebetween. As shown in FIG. 11, the second rod 83 is located on the rear end side and has a first portion 83 c having the same diameter as the first rod 60, and on the front end side, the second rod 83 is slightly larger in diameter than the first rod 60. 2 part 83d, and is located between the 1st part 83c and the 2nd part 83d, and consists of the small diameter part 83b smaller than the 1st rod 60 in diameter. The second portion 83d is fixed to the seat member 54b of the bellows 54. The second rod 83 corresponds to the first valve body.

  A cylindrical spool 82 is press-fitted into the tip of the first rod 60, and the first portion 83 c of the second rod 83 can slide within the spool 82. The first rod 60 and the spool 82 correspond to a second valve body that moves integrally.

  The spool 82 is integrated with the large-diameter portion 82a slidable in the first shaft hole 81d, the large-diameter portion 82a on the rear side, and the first medium-diameter portion 82h slightly smaller in diameter than the large-diameter portion 82a, The first medium diameter portion 82h is integrated with the first medium diameter portion 82h, the small diameter portion 82i slightly smaller in diameter than the first medium diameter portion 82h, and the rear portion is integrated with the small diameter portion 82i, and the second medium diameter slightly larger than the small diameter portion 82i. And a diameter portion 82b. The small diameter portion 82 i is located between the front end surface 60 a of the first rod 60 and the rear end surface 83 a of the first portion 83 c in the second rod 83. The small diameter portion 82i is movable in the third valve seat 93a.

  A large diameter portion 82 a of the spool 82 is formed with a first hole 82 c that extends in the radial direction and communicates or disconnects the high pressure hole 81 a of the first housing 51 and the small diameter portion 83 b of the second rod 83. The large-diameter portion 82a is formed with a second hole 82d that is located behind the first hole 82c and extends in the radial direction and communicates with the small-diameter portion 83b. Further, a third hole 82 e that communicates between the front end surface 60 a of the first rod 60 and the rear end surface 83 a of the second rod 83 is formed in the second medium diameter portion 82 b of the spool 82.

  The first medium diameter portion 82h and the small diameter portion 82i have communication passages 82f and 82g with respect to the first shaft hole 81d and the third valve seat 93a. These communication passages 82f and 82g can communicate the second hole 82d with the second shaft hole 81f. The communication paths 82f and 82g correspond to throttles that reduce the pressure of the refrigerant.

  In the capacity control device 80, the second valve seat 91a and the tip end portion 91b of the large diameter portion 82a of the spool 82, which is a part of the second valve body, are used as pressure regulating valves for adjusting the passage opening degree of the air supply passage 40f. The air supply valve 91 is configured.

  Further, the middle diameter portion 82h side in the first hole 82c of the large diameter portion 82a of the spool 82 is a first valve seat 92a. The first return valve 92 that adjusts the opening degree of the return passage 40g is configured by the first valve seat 92a and the distal end portion 92b of the second portion 83d of the second rod 83 that is the first valve body. ing.

  Further, the third valve seat 93a of the first housing 51 and the boundary passage 93b of the spool 82 which is a part of the second valve body and the boundary 93b of the communication passage 82g are used to adjust the opening degree of the return passage 40g. A two-return valve 93 is configured.

  Other configurations of the second embodiment are the same as those of the first embodiment. For this reason, the same code | symbol is attached | subjected about the same structure and detailed description is abbreviate | omitted.

  In this capacity control device 80, as shown in FIGS. 12 to 14, the compressor body 10 is controlled by adjusting the air supply valve 91 and the first and second return valves 92 and 93 in accordance with the suction pressure Ps ′. .

  That is, when the compressor has been stopped for a long time and liquid refrigerant has accumulated in the crank chamber 9, as shown in FIG. 12, the pressure sensitive chamber 53 has high pressure due to the liquid refrigerant in the crank chamber 9. A crank pressure Pc is introduced. Further, the suction pressure Ps ′ acts on the rear end face 83 a of the second rod 83. For this reason, the bellows 54 is reduced until the stopper portion 54d contacts the stopper member 54e. For this reason, the 2nd rod 83 moves ahead.

  On the other hand, the control coil 62 shown in FIG. 10 is excited, and the movable iron core 58 approaches the fixed iron core 55. For this reason, as shown in FIG. 12, the 1st rod 60 and the spool 82 have moved to the front end side. For this reason, the front-end | tip part 91b of the large diameter part 82a of the spool 82 moves to a front end side, and is seated on the 2nd valve seat 71a, and the air supply valve 91 closes. For this reason, the first passage 40a and the third passage 40c do not communicate with each other, and the air supply passage 40f is closed.

  Further, the first hole 82c of the large diameter portion 82a of the spool 82 and the small diameter portion 83b of the second rod 83 communicate with each other, and the first return valve 92 opens the inlet of the return passage 40g. Further, the third valve seat 93a of the first housing 51 and the communication passages 82f, 82g of the spool 82 communicate with each other, and the second return valve 93 opens the outlet of the return passage 40g.

  Therefore, the third passage 40c, the high pressure hole 81a, the first hole 82c, the small diameter portion 83b, the second hole 82d, the first shaft hole 81d, the communication passages 82f and 82g, the second shaft hole 81e, the low pressure hole 81b, and the second A high discharge pressure Pd is introduced into the suction chamber 5a through the passage 40b, and the suction pressure Ps in the suction chamber 5a becomes higher than in the prior art.

  At this time, in the capacity control device 80 of the second embodiment, the suction pressure Ps ′ acting by the pressure detection hole 81c and the third passage 40h is not the suction pressure Ps acting by the low pressure hole 81b and the second passage 40b. 83 acts on the rear end face 83a.

  In the capacity control device 50 of the first embodiment, the suction pressure Ps acting by the low pressure hole 81b and the second passage 40b acts on the rear end surface 61a of the second rod 61, and the first return valve 72 is opened and closed by the suction pressure Ps. . When the return passage 40g is opened by opening the first return valve 72, the suction pressure Ps acting on the rear end surface 61a of the second rod 61 is slightly increased by the discharge pressure Pd. Therefore, it is difficult for the first return valve 72 to reduce the passage opening.

  On the other hand, the capacity control device 80 of the second embodiment is not the suction pressure Ps in which the pressure immediately increases due to the influence of the discharge pressure Pd by the opening of the first return valve 92, but the pressure detection hole 81c and the third Since the first return valve 92 is opened and closed by the suction pressure Ps ′ that is acted by the passage 40h and is not easily affected by the discharge pressure Pd due to the opening of the first return valve 92, the first return valve 92 is stably opened. Reduce the opening.

  For this reason, in this compressor, even when the liquid refrigerant is accumulated in the crank chamber 9 at the time of startup, the compressor can be returned more stably and earlier than in the first embodiment.

  Further, in the state where the control coil 62 shown in FIG. 10 is excited, if the liquid refrigerant in the crank chamber 9 is less than a certain amount, the crank pressure Pc is lowered and the suction pressure Ps is lowered from the set pressure. As shown in FIG. 13, the bellows 54 is extended by the urging force of the spring 54f. For this reason, the 2nd rod 83 moves back, and the front-end | tip part 92b of the 2nd rod 83 seats on the 1st valve seat 91a. For this reason, the first hole 82c of the large diameter portion 82a of the spool 82 and the small diameter portion 83b of the second rod 83 are disconnected, the first return valve 92 is closed, and the inlet of the return passage 40g is closed. The third valve seat 93a of the first housing 51 and the communication passages 82f and 82g of the spool 82 are in communication with each other, and the second return valve 93 keeps the outlet of the return passage 40g open.

  At this time, since the control coil 62 shown in FIG. 10 is excited, as in the first embodiment, if the suction pressure Ps ′ changes due to the magnitude of the thermal load, the tip end portion 91b of the spool 82 and the second valve seat 91a. And the air supply valve 91 adjusts the passage opening of the air supply passage 40f.

  For this reason, when the air supply valve 91 opens the air supply passage 40f, the inclination angle of the swash plate 17 is appropriately reduced as in the first embodiment, and the discharge capacity per one rotation of the drive shaft 11 is reduced. Further, the inclination angle of the swash plate 17 is appropriately increased, and the discharge capacity per one rotation of the drive shaft 11 is increased.

  On the other hand, if the control coil 62 shown in FIG. 10 is demagnetized, the first rod 60 and the spool 82 move backward in a short time as in the first embodiment. For this reason, as shown in FIG. 14, the tip end portion 91b of the spool 82 quickly moves to the rear side of the second valve seat 91a, and the air supply valve 91 quickly increases the passage opening degree of the air supply passage 40f. . For this reason, as in the first embodiment, the high-pressure refrigerant gas in the discharge chamber 5b moves into the crank chamber 9 in a short time.

  Therefore, in this compressor, as in the first embodiment, the crank pressure Pc rises rapidly, the inclination angle of the swash plate 17 is quickly minimized, and the discharge capacity of the compressor is minimized. Thus, with this compressor, the load on the vehicle can be quickly reduced when the vehicle is accelerated.

  Therefore, this compressor can produce an effect superior to that of the first embodiment. Other functions and effects are the same as those of the first embodiment.

  In the first and second embodiments, the first and second return valves 72 and 73 are connected to the return passage 40g when the compressor is started based on the crank pressure Pc and the suction pressure Ps, which are the internal pressures of the compressor. However, the first and second return valves 72 and 73 need only increase the passage opening of the return passage 40g when the compressor is started based on at least the suction pressure Ps. Also, the following modifications are possible.

(Modification 1)
It is also possible to configure the capacity control device to increase the passage opening of the return passage 40g based on the determination of whether or not the vehicle is being started, the start of the air conditioner, or the like.

(Modification 2)
Further, based on the determination by the detection signal for detecting the crank pressure Pc, the capacity control device can increase the passage opening of the return passage 40g.

  In the above, the present invention has been described with reference to the first and second embodiments. However, the present invention is not limited to the first and second embodiments, and is appropriately modified and applied without departing from the spirit of the present invention. Needless to say, it can be done.

  For example, as a capacity control device provided with a return valve, in addition to the capacity control devices 50 and 80 for controlling the passage opening degree of the air supply passage 40f in the variable displacement swash plate compressor as described above, the passage of the extraction passage 40d A capacity control device that controls the opening degree, and a capacity control device that controls the passage opening degree of the supply passage 40f and the extraction passage 40d may be used.

  The present invention is applicable to an air conditioning system.

5a ... Suction chamber 5b ... Discharge chamber 9 ... Crank chamber 1a ... Cylinder bore 1, 3, 5, 23 ... Body housing (1 ... Cylinder block, 3 ... Front housing, 5 ... Rear housing, 23 ... Valve unit)
DESCRIPTION OF SYMBOLS 11 ... Drive shaft 17 ... Swash plate 24 ... Compression chamber 21 ... Piston Pc ... Crank pressure Ps, Ps' ... Suction pressure 40f ... Supply passage 40d ... Extraction passage 40g ... Return passage 71 ... Pressure regulation valve (supply valve)
72, 73 ... return valve (72 ... first return valve, 73 ... second return valve)
40e ... Extraction throttle 10 ... Compressor body 50, 80 ... Capacity control device 51, 57, 52, 64, 62 ... Valve housing (51 ... First housing, 57 ... Second housing, 52 ... Filter, 64 ... Cover, 62 …connector)
51b, 53a ... pressure sensitive passage (51b ... pressure sensitive hole, 53b ... adjusting hole)
51c ... High pressure passage (high pressure hole)
51d ... Low pressure passage (low pressure hole)
62 ... Control coil 61 ... First valve body (second rod)
60, 65 ... second valve body (60 ... first rod, 65 ... spool)
72a ... 1st valve seat 71a ... 2nd valve seat 73a ... 3rd valve seat 81c ... Detection passage (pressure detection hole)

Claims (8)

A main body housing in which a suction chamber, a discharge chamber, a crank chamber, and a cylinder bore are formed; a drive shaft that is rotatably supported in the crank chamber; and a tilt that is rotatably supported by the drive shaft in the crank chamber A swash plate whose corners are supported so as to be changeable, and a piston which is reciprocally accommodated in the cylinder bore and forms a compression chamber,
A differential pressure between a crank pressure that is a pressure of the crank chamber and a suction pressure that is a pressure of the suction chamber acts on the piston during a suction stroke,
The discharge chamber and the crank chamber communicate with each other through an air supply passage;
The crank chamber and the suction chamber communicate with each other through an extraction passage;
The discharge chamber and the suction chamber communicate with each other through a return passage;
At least one of the supply passage and the extraction passage is provided with a pressure regulating valve that changes the crank pressure by adjusting a passage opening degree,
The return passage includes a return valve that opens and closes the return passage and opens when the suction pressure exceeds a threshold value, and a throttle that reduces the pressure of the refrigerant flowing through the return passage when the return valve is opened. A variable capacity swash plate compressor characterized in that it is provided. The pressure regulating valve is an air supply valve provided in the air supply passage,
The variable displacement swash plate compressor according to claim 1, wherein an extraction throttle is provided in the extraction passage.   3. The variable capacity swash plate compressor according to claim 2, wherein a capacity control device is provided integrally with the air supply passage, the return passage, the air supply valve, and the return valve.   4. The variable displacement swash plate compressor according to claim 3, wherein the return valve opens when the variable displacement swash plate compressor is started. In the capacity control device, a pressure sensitive passage communicating with the crank chamber,
A high-pressure passage communicating with the discharge chamber;
A low pressure passage communicating with the suction chamber is formed;
The capacity control device includes a control coil that can be excited or demagnetized, and
A first valve body that opens and closes by receiving the suction pressure of the suction chamber and opens when the suction pressure exceeds the threshold;
A first valve seat to which the first valve body comes in contact with and separates;
A second valve element that operates by excitation of the control coil;
A second valve seat to which the second valve body comes in contact with and separates from, and
The return passage is constituted by the high pressure passage and the low pressure passage,
The first valve body and the first valve seat are arranged between the high pressure passage and the low pressure passage to constitute the return valve,
The air supply passage is constituted by the pressure sensitive passage and the high pressure passage,
5. The variable displacement swash plate compression according to claim 3, wherein the second valve body and the second valve seat are arranged between the pressure-sensitive passage and the high-pressure passage to constitute the air supply valve. Machine. The capacity control device includes a third valve element that operates by excitation of the control coil,
A third valve seat that contacts and separates the third valve body;
The third valve body and the third valve seat are disposed between the high pressure passage and the low pressure passage,
The return valve includes a first return valve constituted by the first valve body and the first valve seat;
A second return valve composed of the third valve body and the third valve seat;
6. The variable displacement swash plate compressor according to claim 5, wherein the third valve body is biased in the valve opening direction by excitation of the control coil. In the capacity control device, a detection passage communicating with the suction chamber is partitioned from the low pressure passage,
The variable displacement swash plate compressor according to claim 6, wherein the first valve body is opened when the suction pressure in the detection passage becomes higher than a threshold value. A main body housing in which a suction chamber, a discharge chamber, a crank chamber, and a cylinder bore are formed; a drive shaft that is rotatably supported in the crank chamber; and a tilt that is rotatably supported by the drive shaft in the crank chamber A swash plate whose corners are supported so as to be changeable, and a piston which is reciprocally accommodated in the cylinder bore and forms a compression chamber,
A differential pressure between a crank pressure that is a pressure of the crank chamber and a suction pressure that is a pressure of the suction chamber acts on the piston during a suction stroke,
The discharge chamber and the crank chamber communicate with each other through an air supply passage, the crank chamber and the suction chamber communicate with each other through an extraction passage, and the discharge chamber and the suction chamber communicate with each other through a return passage,
A capacity control device used in a variable capacity compressor that controls the discharge capacity by changing the pressure in the crank chamber,
The air supply passage;
The extraction passage;
The return path;
An air supply valve for adjusting a passage opening of the air supply passage;
An extraction throttle for restricting the extraction passage;
A return valve for adjusting the opening of the return passage;
A capacity control device comprising a throttle for reducing the pressure of the refrigerant flowing through the return passage when the return valve is opened.

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