JP4412186B2 - Variable capacity compressor - Google Patents

Description

  The present invention relates to a variable capacity compressor, and more particularly to reduction of vibration and noise caused by suction pulsation during variable capacity operation.

  Conventionally, piston type compressors have been provided with a stopper so that the suction reed valve does not vibrate when it generates income. However, in piston type variable displacement compressors, the amount of intake gas differs between the maximum capacity and variable capacity. When starting up, the suction reed valve does not open sufficiently and does not hit the stopper. For this reason, the suction reed valve causes self-excited vibration, which causes suction pulsation, which propagates outside the compressor and generates abnormal noise.

  Therefore, for example, Patent Document 1 discloses a compressor that is provided with an opening degree control valve that controls the opening area of the suction passage to reduce pressure fluctuation at a low flow rate.

JP 2000-136776 A

However, in the above-mentioned Patent Document 1, since the opening degree control valve is operated using the differential pressure due to the gas flow in the suction passage and the spring force, if the effect of the throttle is emphasized, the throttle effect can be obtained even at the maximum capacity. If the performance is reduced and the performance at the maximum capacity is ensured, there is a problem that it is not possible to sufficiently squeeze at a low capacity where the squeezing effect is required.
The present invention has been made to solve such a conventional problem, and can surely reduce the pressure fluctuation at the time of variable capacity, and can sufficiently secure the flow rate at the maximum capacity and maintain the performance. An object is to provide a variable capacity compressor.

The variable capacity compressor according to the present invention is a variable capacity compressor in which the capacity is variably controlled. The variable capacity compressor includes a muffler on the suction passage and adjusts the opening of the suction passage according to the capacity value on the suction passage. A control valve is provided , the opening control valve increases the opening of the suction passage during maximum capacity operation than during variable displacement operation, and the opening control valve is movably disposed in response to suction pressure and the suction passage A valve body that opens and closes, a movable body that is movably disposed in response to the crank chamber pressure, and a biasing member that biases the movable body and the valve body in a direction to separate them from each other .

  By adjusting the opening of the suction passage according to the capacity value with the opening control valve, the opening of the suction passage is increased at the maximum capacity to ensure the performance, and when the capacity is small, the suction passage is throttled to suck in by the muffler The effect of reducing pulsation can be maximized.

Preferably, the capacity is variably controlled by adjusting the crank chamber pressure, and the opening control valve adjusts the opening of the suction passage based on a differential pressure between the suction pressure and the crank chamber pressure. Further, the movable body is the valve body by moving to a position where the urging force is not applied by and the biasing member to maximize the opening of the suction passage at the time of maximum displacement operation, squeeze the opening of the suction passage by the valve body at the time of variable displacement operation It can be configured to move to a position. The movement of the movable body may be restricted by a stopper.

An opening communicating with the suction passage is formed on the inner wall surface of the valve chamber of the opening control valve, and an effective area of the opening for determining the opening of the suction passage is determined by the position of the valve body movably disposed in the valve chamber. Can be adjusted. Alternatively, an opening communicating with the suction passage is formed in the valve body, and the effective area of the opening that determines the opening degree of the suction passage is adjusted by the position of the valve body movably disposed in the valve chamber of the opening degree control valve. Also good.
Further, the suction passage and the suction chamber can be always communicated with each other.

  According to the present invention, since the muffler is provided on the suction passage and the opening control valve for adjusting the opening degree of the suction passage according to the capacity value is provided on the suction passage, the opening degree can be sufficiently obtained at the maximum capacity. Therefore, the suction pulsation can be reduced by the muffler by sufficiently narrowing the opening of the suction passage when the capacity is small and the pulsation needs to be reduced.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
Embodiment 1
FIG. 1 shows the structure of the variable capacity compressor according to the first embodiment. A front housing 2 is connected to the front end portion of the cylinder block 1, and a rear housing 4 is connected to the rear end portion via a valve forming body 3. A crank chamber 5 is defined by the cylinder block 1 and the front housing 2, and a drive shaft 6 is rotatably supported by the cylinder block 1 and the front housing 2 so as to penetrate the crank chamber 5. A front end portion of the drive shaft 6 protrudes from the front housing 2 and is connected to a rotation drive source (not shown) such as an engine or a motor of the vehicle. A rotary support 7 is fixed to the drive shaft 6 in the front housing 2 and a swash plate 8 is attached so as to engage with the rotary support 7. The swash plate 8 is slidable into a guide hole 10 formed in the rotary support 7 with a guide pin 9 protruding from the swash plate 8 with the drive shaft 6 passing through a through hole formed in the center of the swash plate 8. The guide pin 9 and the guide hole 10 are supported so as to rotate integrally with the drive shaft 6 and to be slidable and tiltable in the axial direction of the drive shaft 6. The rotary support 7 is rotatably supported by a thrust bearing 11 disposed on the front end inner wall portion of the front housing 2.

  In the cylinder block 1, a plurality of cylinder bores 12 are arranged around the drive shaft 6, and a piston 13 is slidably accommodated in each cylinder bore 12. Each piston 13 is engaged with the outer peripheral portion of the swash plate 8 via a shoe 14, and when the swash plate 8 rotates together with the drive shaft 6, each piston 13 moves inside the cylinder bore 12 via the shoe 14. Reciprocates in the axial direction.

A suction chamber 15 is defined at the center of the rear housing 4 so as to face the valve forming body 3, and a discharge chamber 16 is defined at the outer periphery of the suction chamber 15 so as to surround the suction chamber 15.
The cylinder block 1 and the rear housing 4 are formed with a communication passage 17 that always communicates the crank chamber 5 and the discharge chamber 16, and a capacity control valve 18 that is an electromagnetic valve is disposed in the communication passage 17. It is installed. Further, the cylinder block 1 is formed with an extraction passage 19 that allows the crank chamber 5 and the suction chamber 15 to communicate with each other.

  Further, the rear housing 4 is formed with a suction port 20 exposed to the outside, and the suction port 20 and the suction chamber 15 are communicated with each other by a suction passage 21. A muffler 22 for reducing suction pulsation is formed in the middle of the suction passage 21, and a valve of the opening control valve V that movably adjusts the opening of the suction passage 21 on the suction passage 21 upstream of the muffler 22. A chamber 23 is formed. The valve chamber 23 and the muffler 22 communicate with each other through a suction port 24 opened in the inner wall surface of the valve chamber 23. In the valve chamber 23, a bottomed cylindrical valve body 25 for opening and closing the suction passage 21 is movably accommodated. The bottom 23 a of the valve chamber 23 communicates with the crank chamber 5 through communication passages 26 and 17.

As shown in FIG. 2, the valve body 25 of the opening control valve V has a suction pressure Ps on the front surface facing the suction port 20 and a pressure Pc on the crank chamber 5 on the rear surface facing the bottom 23 a of the valve chamber 23. The valve body 25 moves in the valve chamber 23 in accordance with the differential pressure between the suction pressure Ps and the pressure Pc of the crank chamber 5.
A part or the whole of the suction port 24 is exposed in the muffler 22 depending on the position of the valve body 25 in the valve chamber 23, whereby the suction port 20 and the suction chamber 15 are configured to communicate with each other. That is, the effective area of the suction port 24 is adjusted based on the position of the valve body 25 in the valve chamber 23, and the opening degree of the suction passage is determined.

  A stopper 23b for restricting the movement of the valve body 25 is disposed on the inner wall portion of the valve chamber 23, and the valve body 25 moves forward in the valve chamber 23 toward the suction port 20 and comes into contact with the stopper 23b. Then, only a part of the suction port 24 is opened, and the passage of the suction gas is throttled. On the other hand, when the valve body 25 retreats in the valve chamber 23 toward the bottom 23a, the suction port 24 is fully opened as shown in FIG.

  Next, the operation of the variable capacity compressor according to the first embodiment will be described. The reciprocating operation of the piston 13 accompanying the rotational drive of the drive shaft 6, that is, the operation of retreating in the cylinder bore 12, causes the refrigerant gas in the suction chamber 15 to push the suction lead portion from the suction port 27 of the valve forming body 3 and into the cylinder bore 12. Then, the forward movement of the piston 13, that is, the forward movement of the cylinder bore 12, pushes the discharge lead portion from the discharge port 28 of the valve forming body 3 and discharges it into the discharge chamber 16.

  By changing the opening of the capacity control valve 18, the amount of gas introduced from the discharge chamber 16 to the crank chamber 5 via the communication passage 17 and the amount of gas discharged from the crank chamber 5 to the suction chamber 15 via the extraction passage 19 are obtained. Is controlled to determine the pressure Pc of the crank chamber 5. When the opening degree of the capacity control valve 18 is changed and the pressure Pc of the crank chamber 5 is changed, the differential pressure between the crank chamber 5 and the cylinder bore 12 via the piston 13 is changed, and the inclination angle of the swash plate 8 is changed. Change. As a result, the stroke of the piston 13, that is, the discharge capacity of the compressor is adjusted.

  For example, when the pressure Pc in the crank chamber 5 is lowered, the inclination angle of the swash plate 8 is increased, the stroke of the piston 13 is increased, and the discharge capacity is increased. Conversely, when the pressure Pc in the crank chamber 5 is increased, the inclination angle of the swash plate 8 is reduced, the stroke of the piston 13 is reduced, and the discharge capacity is reduced.

  Here, at the time of maximum capacity operation, the pressure Pc of the crank chamber 5 is reduced by the setting of the opening degree of the capacity control valve 18, and becomes substantially equal to the suction pressure Ps. Since the crank chamber pressure Pc becomes substantially equal to the suction pressure Ps, the force that urges the valve body 25 of the opening control valve V in a direction in which the crank chamber pressure Pc squeezes the suction passage 21 against the suction pressure Ps. Disappear. For this reason, the valve body 25 of the opening degree control valve V moves backward in the valve chamber 23 toward the bottom 23a by the intake gas flow flowing from the intake port 20 into the intake chamber 15 through the intake passage 21. As a result, as shown in FIG. 3, the suction port 24 is fully opened, and the maximum capacity can be discharged. At this time, since the urging force by the spring or the like does not act on the valve element 25 of the opening control valve V, there is almost no energy loss when the valve element 25 is retracted, and the performance at the maximum capacity operation is ensured.

  On the other hand, during variable displacement operation, the pressure Pc in the crank chamber 5 is increased by setting the opening of the displacement control valve 18 to be higher than the suction pressure Ps. For this reason, the valve body 25 of the opening degree control valve V moves forward in the valve chamber 23 toward the suction port 20, and when the valve body 25 comes into contact with the stopper 23b, as shown in FIG. Advancement is regulated. As a result, only a part of the suction port 24 is opened, and the passage of the suction gas is narrowed. Since the suction gas enters the muffler 22 through the narrowed passage, the effect of the muffler 22 is drawn out to the maximum, and the suction pulsation is sufficiently reduced.

Embodiment 2
FIG. 4 shows the structure of the opening control valve of the variable capacity compressor according to the second embodiment. A bottomed cylindrical valve body 29 is movably accommodated in the valve chamber 23 of the opening degree control valve V, and a bottomed cylindrical movable body 30 is movably accommodated on the rear side of the valve body 29. A spring 31 is disposed between the body 29 and the movable body 30 as a biasing member that biases them in a direction to separate them from each other. A stopper 32 for restricting movement of the movable body 30 is disposed on the inner wall portion of the valve chamber 23 between the valve body 29 and the movable body 30. The suction pressure Ps in the direction of opening the suction port 24 via the suction passage 21 on the front surface of the valve body 29, and the pressure Pc of the crank chamber 5 in the direction of closing the suction port 24 on the rear surface of the movable body 30 via the communication passage 26. Each is acting. The structure of other parts is the same as that of the first embodiment.

  During the maximum capacity operation, the pressure Pc in the crank chamber 5 becomes substantially equal to the suction pressure Ps, so that the valve body 29 is pressed toward the bottom 23 a in the valve chamber 23 by the suction gas flow, and the movable body 30 is moved by the valve body 29. The suction passage is maximized and the urging force of the spring 31 is weakened or retracted to a position where it does not substantially act. Thereby, as shown in FIG. 5, the suction port 24 is fully opened. At this time, the effect of restricting the suction port 24 by the valve body 29 can be substantially eliminated, and the performance at the maximum capacity operation where the efficiency of the compressor is required is ensured.

  On the other hand, during variable displacement operation, the pressure Pc in the crank chamber 5 is increased and becomes higher than the suction pressure Ps, and therefore the suction pressure Ps acting on the valve body 29 of the spring 31 by the movable body 30 moving forward in the valve chamber 23. In this state, the suction passage is closed against the suction gas flow. Thereby, the suction passage is gradually throttled. As shown in FIG. 4, when the movable body 30 comes into contact with the stopper 32, the forward movement of the movable body 30 is restricted, and the urging force acting on the valve body 29 by the spring 31 acts to the maximum, and the flow rate of the intake gas is increased. The resisting squeezing effect increases. As a result, the effect of the muffler 22 is drawn out to the maximum, and the pressure fluctuation is sufficiently suppressed.

  Similarly, even at the time of start-up from the OFF capacity operation that requires the effect of restricting the suction passage, the movable body 30 moves forward until the movable body 30 comes into contact with the stopper 32 as shown in FIG. As a result, the urging force acting on the valve body 29 becomes strong. For this reason, at the time of the capacity recovery start to increase the capacity, a large throttle effect is exhibited against the flow rate of the suction gas, the effect of the muffler 22 is drawn out to the maximum, the pressure fluctuation is sufficiently suppressed, and the abnormal noise is Generation etc. are prevented.

  In the second embodiment, the space between the valve body 29 and the movable body 30 is almost sealed to give a damper effect, and the valve body 29 itself vibrates due to suction pulsation and generates abnormal noise. And the effect of the aperture is secured.

  Further, as shown in FIG. 5, during the maximum capacity operation, the valve body 29 is retracted until it comes into contact with the stopper 32, and the suction port 24 is fully opened to maximize the opening of the suction passage. Even when the movable body 30 reaches the bottom 23 a of the valve chamber 23, the valve body 29 can be separated from the stopper 32 by the biasing force of the spring 31. This makes it possible to exhibit a throttling function against fluctuations in the intake gas flow rate even during maximum capacity operation.

Embodiment 3
In the first embodiment, the suction port 24 is opened on the inner wall surface of the valve chamber 23, and the suction port 24 is opened and closed by moving the cylindrical valve body 25 in the valve chamber 23. However, the present invention is not limited to this. Alternatively, as shown in FIG. 6, a structure may be employed in which a suction port 34 is formed in the valve body 33 that moves in the valve chamber 23, and the suction port 34 is opened and closed by moving the valve body 33. .

  During the maximum capacity operation, the pressure Pc of the crank chamber 5 is reduced and becomes substantially equal to the suction pressure Ps, so the valve of the opening control valve V in the direction in which the crank chamber pressure Pc squeezes the suction passage 21 against the suction pressure Ps. The force for urging the body 33 disappears, and the valve body 33 of the opening degree control valve V moves backward in the valve chamber 23 toward the bottom 23a by the suction gas flow flowing from the suction port 20 to the suction chamber 15 through the suction passage 21. To do. As a result, as shown in FIG. 7, the suction port 34 is fully opened, and the maximum capacity can be discharged. At this time, since the urging force by the spring or the like does not act on the valve element 33 of the opening control valve V, there is almost no energy loss when the valve element 33 is retracted, and the performance at the maximum capacity operation is ensured.

  On the other hand, during variable displacement operation, the pressure Pc in the crank chamber 5 is increased and becomes higher than the suction pressure Ps, so that the valve element 33 of the opening control valve V moves forward in the valve chamber 23 toward the suction port 20. As shown in FIG. 6, the advancement of the valve element 33 is restricted when the valve element 33 comes into contact with the stopper 23b. Thereby, only a part of the suction port 34 is opened, the passage of the suction gas is narrowed, the effect of the muffler 22 is drawn out to the maximum, and the suction pulsation is sufficiently reduced.

  In addition, in the opening degree control valve V having a structure in which the opening degree of the suction passage 21 is adjusted by moving the valve body 33 in which the inlet port 34 is formed as described above, the valve body is the same as in the second embodiment. A movable body can be connected to 33 via a spring to give a damper effect. As a result, it is possible to prevent the valve body 33 itself from vibrating due to the suction pulsation and generating an abnormal noise, and to ensure the effect of throttling.

  In the above-described first and third embodiments, the valve body does not fully close the suction port when the capacity is OFF, and the suction passage and the suction chamber are always in communication. It is also possible to adopt a configuration in which the suction port is fully closed during capacity operation and OFF operation.

  In the first to third embodiments, the opening degree control valve V that movably adjusts the opening degree of the suction passage 21 is disposed on the suction passage 21 on the upstream side of the muffler 22. It can also be disposed on the passage 21.

It is sectional drawing which shows the structure of the variable capacity compressor which concerns on Embodiment 1 of this invention. It is a figure which shows typically the mode of the opening degree control valve at the time of the variable displacement driving | operation in Embodiment 1. FIG. It is a figure which shows typically the mode of the opening degree control valve at the time of the maximum capacity | capacitance driving | operation in Embodiment 1. FIG. It is a figure which shows typically the mode of the opening degree control valve at the time of the variable capacity | capacitance driving | operation in Embodiment 2. FIG. It is a figure which shows typically the mode of the opening degree control valve at the time of the maximum capacity | capacitance driving | operation in Embodiment 2. FIG. It is a figure which shows typically the mode of the opening degree control valve at the time of the variable displacement driving | operation in Embodiment 3. FIG. FIG. 10 is a diagram schematically showing the state of an opening degree control valve at the time of maximum capacity operation in Embodiment 3.

Explanation of symbols

  1 cylinder block, 2 front housing, 3 valve forming body, 4 rear housing, 5 crank chamber, 6 drive shaft, 7 rotation support, 8 swash plate, 12 cylinder bore, 13 piston, 15 suction chamber, 16 discharge chamber, 17, 26 communication passage, 18 capacity control valve, 20 suction port, 21 suction passage, 22 muffler, 23 valve chamber, 23a bottom, 23b, 32 stopper, 24, 34 suction port, 25, 29, 33 valve body, 30 movable body, 31 Spring.

Claims (8)

In a variable capacity compressor whose capacity is variably controlled,
Provided with a muffler on the suction passage and an opening control valve for adjusting the opening of the suction passage according to the capacity value on the suction passage ,
The opening control valve increases the opening of the suction passage during maximum capacity operation than during variable capacity operation,
The opening control valve is
A valve body that is movably arranged to receive suction pressure and opens and closes the suction passage;
A movable body arranged to be movable under the pressure of the crank chamber;
An urging member that urges the movable body and the valve body in a direction to separate them from each other;
Variable displacement compressor characterized in that it comprises a. The variable displacement compressor according to claim 1 , wherein the opening degree control valve maximizes the opening degree of the suction passage during maximum capacity operation. The capacity is variably controlled by adjusting the crank chamber pressure,
The variable displacement compressor according to claim 1 or 2 , wherein the opening degree control valve adjusts an opening degree of the suction passage based on a differential pressure between the suction pressure and the crank chamber pressure. The movable body moves to a position where the opening of the suction passage is maximized by the valve body during maximum capacity operation and the biasing force by the biasing member does not act, and the opening of the suction passage is driven by the valve body during variable displacement operation. The variable capacity compressor according to any one of claims 1 to 3, wherein the compressor moves to a position where the pressure is reduced. The variable capacity compressor as described in any one of Claims 1-4 provided with the stopper which controls the movement of the said movable body. An opening communicating with the suction passage is formed on the inner wall surface of the valve chamber of the opening control valve, and the opening that determines the opening of the suction passage is determined by the position of the valve body that is movably disposed in the valve chamber. The variable capacity compressor according to any one of claims 1 to 5 , wherein the area is adjusted. An opening communicating with the suction passage is formed in the valve body, and an effective area of the opening that determines the opening degree of the suction passage is adjusted by the position of the valve body movably disposed in the valve chamber of the opening degree control valve. The variable capacity compressor according to any one of claims 1 to 5 . The variable capacity compressor according to any one of claims 1 to 7 , wherein the suction passage and the suction chamber are always in communication.

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