JP2007309198A - Swash plate type compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve control response by reducing variable control start necessary pressure difference of swash plate angles and improve controllability by enabling to perform minute displacement change easily and accurately in a low displacement range in relation to control of a control valve in a swash plate compressor. <P>SOLUTION: In this swash plate type compressor, a plurality of cylinder bores is arranged in a radial shape, pistons are inserted in every cylinder bores in such a manner that the same can freely reciprocate, and each piston is engaged with a swash plate for converting rotary motion of a compressor drive shaft to reciprocating motion of the piston, a control valve capable of adjusting crank chamber pressure is provided between a delivery chamber and a crank chamber, a passage capable of making communication among the plurality of cylinder bores, and means controlling communication/non-communication of the passage (especially a piston valve 18) is provided. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a swash plate compressor suitable for a vehicle air conditioner and the like, and more particularly to a swash plate compressor capable of variably controlling the capacity with high responsiveness even in a low capacity range. The swash plate compressor in the present invention is a concept of a compressor including a so-called oscillating plate compressor having an oscillating plate.

  In the case of a swash plate type variable capacity compressor used for a vehicle air conditioner, etc., the crank chamber pressure is controlled by giving a differential pressure to the discharge chamber pressure by a control valve arranged between the discharge chamber and the crank chamber. There is provided a mechanism for adjusting the capacity and thereby changing the capacity by changing the swash plate angle (piston stroke) (for example, Patent Document 1). An example of such a swash plate type variable capacity compressor is shown in FIG.

In the swash plate type variable displacement compressor 100 connected to the refrigeration circuit 101 illustrated in FIG. 9, a plurality of cylinder bores 103 are arranged radially in the cylinder block 102, and the pistons 104 can reciprocate in the cylinder bores 103, respectively. Each piston 104 is engaged via a shoe 107 with a swash plate 106 for converting the rotational movement of the compressor drive shaft 105 into the reciprocating motion of the piston 104, and the swash plate 106 is driven. The rotor 108 and the hinge mechanism 109 fixed to the shaft 105 are rotated together with the drive shaft 105. A discharge chamber 111 and a suction chamber 112 are formed in the cylinder head 110, and a control valve 114 capable of adjusting the crank chamber pressure is provided between the discharge chamber 111 and the crank chamber 113. An axial adjustment screw 115 is disposed at one end of the drive shaft 105, and an orifice filter 117 serving as a filter having an orifice function, which is sealed by an O-ring 116, is provided adjacent thereto. This portion is connected to the suction chamber 112 through the passage 118.
Japanese Patent Laid-Open No. 2002-5022

However, the conventional swash plate type variable displacement compressor as described above generally has the following problems.
First, in the low capacity region, the swash plate angle (piston stroke) tends to become unstable and tends to hunting. Particularly in the case of a low capacity, even a slight change in swash plate angle increases the rate of change with respect to the capacity, making it difficult to control.

  Further, in the control by the control valve, the variable start required differential pressure at which the control is started is almost determined by the refrigerant characteristics (specific heat ratio) and the compressor size, so that it is difficult to largely adjust the variable start required differential pressure. When the control is started in the direction of decreasing the swash plate angle from the maximum capacity operation (zero differential pressure in the control valve), the control start delay is delayed until the variable required differential pressure is reached by the control by the control valve. This will lead to deterioration of controllability.

  Accordingly, an object of the present invention is to improve control responsiveness by reducing the differential pressure required to start variable the swash plate angle in the control of the control valve in the swash plate compressor, and change the capacity slightly in the low capacity range. Therefore, it is possible to improve the controllability so that the control can be performed easily and accurately.

  In order to solve the above problems, a swash plate compressor according to the present invention includes a plurality of cylinder bores arranged radially in a cylinder block, and pistons are reciprocally inserted into the cylinder bores. A swash plate compressor that is engaged with a swash plate for converting the rotational movement of the drive shaft into a reciprocating motion of the piston, and is provided with a control valve capable of adjusting the crank chamber pressure between the discharge chamber and the crank chamber. In addition, a passage capable of communicating between the plurality of cylinder bores is provided, and means for controlling communication / non-communication in the passage is provided.

  In other words, the configuration is such that specific cylinder bores in all cylinder bores can communicate with each other, so that compression work is basically not performed in the specific cylinder bores that are communicated, and the same compression work is performed in the remaining cylinder bores. It was made to let you. In this case, by setting the inside of the cylinder bore during the rest as the suction chamber pressure, a load is applied to the swash plate in a direction to reduce the swash plate angle due to the differential pressure between the cylinder bore pressure and the crank chamber pressure. As a result, it is possible to reduce the variable starting differential pressure required by the control valve for changing the swash plate angle with respect to the remaining cylinder bores. By reducing the variable starting differential pressure difference, it is possible to improve control response for capacity control.

  Further, since the specific cylinder bore is suspended with respect to the compression work and only the remaining cylinder bores can perform the compression work, the capacity is reduced as compared with the case where all the cylinder bores perform the compression work. In this low capacity state, when a predetermined amount of capacity is changed, it is necessary to change the swash plate angle to a greater extent than when all cylinder bores perform compression work. Therefore, the angle change width of the swash plate can be increased. Therefore, when controlling the swash plate angle (piston stroke) for changing the capacity in the low capacity region, the minute angle changing control which is difficult to control becomes unnecessary, and a relatively large angle changing control may be performed. . As a result, in a low capacity region, a minute capacity change can be easily and accurately performed, and the control state can be stabilized.

  The swash plate compressor according to the present invention is basically configured as a variable capacity compressor by controlling the communication between the cylinder bores. However, in this configuration, the swash plate is connected to the compressor drive shaft. Therefore, the present invention can be applied to both a compressor having a configuration in which the angle can be varied and a compressor having a fixed swash plate angle. Further, as described at the beginning, in the present invention, the swash plate compressor is a concept of a compressor including a so-called oscillating plate compressor having an oscillating plate.

  That is, in the swash plate compressor according to the present invention, for example, the swash plate is composed of a swash plate whose angle with respect to the compressor drive shaft can be varied, and a piston valve cylinder is formed at the center of the cylinder block in the radial direction of the compressor. In addition, a piston valve is provided in the piston valve cylinder so as to be movable in the axial direction of the compressor. The piston valve is urged toward the crank chamber by an urging means, A communication passage is provided between the piston valve cylinder for some cylinder bores, a piston valve groove is provided on the outer peripheral surface of the piston valve, and the piston valve groove communicates with the communication passage by movement of the piston valve. In some cases, the cylinder bores are communicated with each other by being configured to communicate with each other. Can means for controlling communication / non-communication of the ability passage and said its passage is a structure that is configured. That is, this is a case where the present invention is applied to a compressor having a swash plate capable of varying the angle.

  Alternatively, in the swash plate compressor according to the present invention, for example, the swash plate is formed of a swash plate whose angle with respect to the compressor drive shaft is fixed, and a piston valve cylinder is formed at the center of the cylinder block in the radial direction of the compressor. In addition, a piston valve is provided in the piston valve cylinder so as to be movable in the axial direction of the compressor. The piston valve is urged toward the crank chamber by an urging means, A communication passage is provided between the piston valve cylinder for some cylinder bores, a piston valve groove is provided on the outer peripheral surface of the piston valve, and the piston valve groove communicates with the communication passage by movement of the piston valve. In some cases, the cylinder bores are communicated with each other by being configured to communicate with each other. Can means for controlling communication / non-communication of the ability passage and said its passage is a structure that is configured. That is, this is a case where the present invention is applied to a compressor having a swash plate with a fixed angle.

  In the swash plate compressor according to the present invention, the piston valve is moved by a differential pressure between a crank chamber pressure introduced from the crank chamber side and a suction pressure introduced from the suction chamber side. Can do. Alternatively, by providing a dedicated actuator (for example, an electromagnetic actuator), the piston valve can be moved by the dedicated actuator regardless of the crank chamber pressure and the suction pressure.

  In particular, when the piston valve is moved by the pressure difference between the crank chamber pressure and the suction pressure, it is preferable that a piston ring is attached to the piston valve in order to perform a necessary seal between the pressures on both sides.

  In order to move the piston valve smoothly, the piston valve is preferably provided with a resin coating (particularly, a resin coating capable of realizing a low sliding resistance).

  According to the swash plate compressor according to the present invention, it is possible to control the communication / non-communication between the cylinder bores so that the compression work is basically not performed in the specific cylinder bores that are communicated. The acting load on the swash plate with respect to the cylinder bore can be a load in the direction of decreasing the swash plate angle, so that the variable differential starting required differential pressure by the control valve for the swash plate angle change with respect to the remaining non-communicating cylinder bore Can be reduced. Thereby, the loss at the time of capacity control operation can be reduced, the performance can be improved, and the control response can be improved.

  Moreover, the compression work of a specific cylinder bore can be suspended by the above communication, and only the remaining cylinder bores can perform the compression work, thereby realizing a low capacity. In this low capacity state, the angle change width of the swash plate for capacity change can be increased, and even a minute capacity change can be easily and accurately performed, and the control is performed by hunting or the like. It becomes possible to carry out stably without accompanying.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a swash plate type compressor according to Embodiment 1 of the present invention, and shows a case where the present invention is applied to a compressor having a structure capable of changing the angle of the swash plate. In FIG. 1, in a swash plate type variable displacement compressor 1 connected to a refrigeration circuit 2, a plurality of cylinder bores 4 are radially arranged in a cylinder block 3, and pistons 5 are reciprocally inserted in the cylinder bores 4, respectively. Has been. Each piston 5 is engaged via a shoe 8 with a swash plate 7 for converting the rotational movement of the compressor drive shaft 6 into a reciprocating motion of the piston 5, and the swash plate 7 is fixed to the drive shaft 6. The rotor 9 and the hinge mechanism 10 are rotated together with the drive shaft 6. A discharge chamber 12 and a suction chamber 13 are formed in the cylinder head 11, and a control valve 15 capable of adjusting the crank chamber pressure is provided between the discharge chamber 12 and the crank chamber 14. A suction valve (not shown) made of a reed valve is provided between the suction chamber 13 and the cylinder bore 4, and a discharge valve (not shown) made of a reed valve is provided between the discharge chamber 12 and the cylinder bore 4. Is provided. An axial adjustment screw 16 is disposed at one end of the drive shaft 6.

  A piston extending in the axial direction of the compressor (axial direction of the drive shaft 6) is disposed at the central portion of the cylinder block 3 in the radial direction of the compressor, that is, at the central portion of the arrangement of the plurality of cylinder bores 4 radially disposed on the cylinder block 3. A valve cylinder 17 is formed, and a piston valve 18 is provided in the piston valve cylinder 17 so as to be movable in the axial direction of the compressor. The piston valve 18 is urged toward the crank chamber 14 by a spring 19 as urging means. For some specific cylinder bores 4 in all the cylinder bores 4, a communication passage 20 is provided between the piston valve cylinder 17 and a piston valve groove 21 extending annularly is provided on the outer peripheral surface of the piston valve 18. When the piston valve groove 21 and the communication path 20 communicate with each other due to the movement of the piston valve 18, the specific cylinder bores 4 are communicated with each other. That is, it is configured such that communication / non-communication between specific cylinder bores 4 can be controlled via the communication path 20 and the piston valve groove 21 by the axial movement of the piston valve 18. The piston valve cylinder 17 is communicated with the suction chamber 13 through a passage 22.

  The piston valve 18 can be moved by a differential pressure between the pressure on the crank chamber 14 side and the pressure on the suction chamber 13 side. An enlarged view of the piston valve 18 installation portion is shown in FIG. 2, and a structural example of the piston valve 18 is shown in FIG. As shown in FIG. 3, in this embodiment, a blow-by escape hole 24 through a filter 23 is provided in the central portion of the piston valve 18. In this embodiment, the bottom surface of the piston valve groove 21 is provided with a passage 25 (hole) between the bores (cylinder bores) that are stopped by communication and the suction side. A passage 26 with the suction side is also formed on the bottom surface of the piston valve 18 on the side opposite to the crank chamber so as to ensure communication with the suction side even when the piston valve 18 moves to the right side in FIG. The piston valve 18 is preferably provided with a piston ring (not shown) on its outer peripheral surface in order to ensure a differential pressure between the pressure on the crank chamber 14 side and the pressure on the suction chamber 13 side. . In order to make the piston valve 18 move in the axial direction more smoothly, the piston valve 18 is preferably provided with a resin coating having a low sliding resistance on the outer peripheral surface thereof.

  The communication control between the cylinder bores by the piston valve 18 will be described with reference to FIG. 4 (during compression operation) and FIG. 5 (when a specific cylinder bore has stopped compression operation [when valve is deactivated]) (FIG. 4, In FIG. 5, the main part for operation | movement description is circled.

  As shown in FIG. 4, when the crank chamber pressure is substantially equal to the suction chamber pressure (that is, when there is no differential pressure therebetween), the piston valve 18 is in the initial state, and the piston valve 18 is pushed by the spring 19. Therefore, the piston valve groove 21 is located at a position different from the communication path 20, and the communication path 20 is closed, and normal compression work is performed in the cylinder bore 4. By setting the load of the spring 19, the movable variable starting required differential pressure can be arbitrarily set.

  As shown in FIG. 5, in the position where the piston valve 18 is moved by the differential pressure between the pressure on the crank chamber 14 side (crank pressure) and the pressure on the suction chamber 13 side (suction pressure), some specific cylinder bores 4 and pistons Since the radial communication passages 20 provided between the valve cylinders 17 are communicated with each other by the piston valve groove 21 and the refrigerant mainly moves between the cylinder bores 4 communicated with each other. Basically, the refrigerant repeatedly moves at the suction pressure. However, in order to adjust the pressure with respect to the suction pressure, the piston valve groove 21 is in communication with the suction side as shown in FIG.

  With respect to some specific cylinder bores 4 that can communicate with the piston valve cylinder 17 via the communication passage 20 and the piston valve groove 21, compression / pause is adjusted by controlling communication / non-communication by movement of the piston valve 18. Therefore, the capacity (flow rate) of the compressor 1 can be controlled. For the remaining cylinder bores 4 not connected by the communication path, the capacity can be controlled by changing the angle of the swash plate 7 (change in piston stroke). At this time, the cylinder bore 4 in the idle state is at the suction pressure, and a load acts in a direction to reduce the swash plate angle due to the differential pressure with respect to the crank pressure. Therefore, the variable required differential start differential pressure of the swash plate angle change can be reduced. .

  Further, the specific cylinder bore 4 communicated as described above does not substantially perform the compression work, and only the remaining cylinder bore 4 performs the compression work, so that a low discharge capacity state appears. Since only this low capacity region can be controlled in the entire swash plate angle (piston stroke) changing region, the controllability is improved, and even when the capacity is to be changed slightly, the change control can be performed accurately and reliably.

  Thus, the piston valve 18 operated by the crank pressure intermittently bypasses the inside of the cylinder bore and the suction side, thereby stopping the operation of the discharge valve and the suction valve and controlling the flow rate (capacity), and the crank pressure. By combining a region for displacement control by changing the swash plate angle change (piston stroke change) via the control valve 15, the variable starting required differential pressure can be reduced. Thereby, the loss at the time of capacity operation is reduced and the capacity is improved, and at the same time, the control response is also improved.

  FIG. 6 illustrates a case in which, in the case of nine cylinders, six cylinders are paused and the remaining three cylinders are capacity controlled. That is, the six bores (cylinder bores) that are hatched are valve pause control bores, and the connected bore pressure maintains the suction pressure by communication with the suction side. The three bores that are not hatched are capacity control bores.

  FIG. 7 shows a swash plate compressor according to Embodiment 2 of the present invention, and shows a case where the present invention is applied to a compressor having a structure in which the angle of the swash plate is fixed. In the swash plate compressor 31 shown in FIG. 7, unlike the structure shown in FIG. 1, the swash plate 32 has a fixed angle. Since the swash plate angle is fixed, the hinge mechanism 10 in FIG. 1 does not exist. Since other structures conform to the structure of the compressor 1 shown in FIG. 1, the same reference numerals as those shown in FIG.

  In this way, in the present invention, the communication / non-communication control structure of the specific cylinder bore 4 can be applied to a fixed angle swash plate compressor (so-called fixed capacity compressor), thereby fixing the fixed capacity compressor. Can be brought into a state close to a variable capacity compressor capable of switching between a normal capacity state and a low capacity state. That is, by communicating between specific cylinder bores 4, compression work is not performed on the communicated cylinder bores 4, and compression work can be performed only on the remaining cylinder bores 4. Low discharge capacity can be realized by reducing the number of cylinders that perform compression work. In this case, since the swash plate angle changing mechanism is not required, the present invention can be implemented at low cost. The other actions and effects of the movement of the piston valve 18 are the same as in the first embodiment.

  FIG. 8 shows a swash plate compressor 41 according to a third embodiment of the present invention. In this embodiment, a differential pressure between the crank pressure and the suction pressure is used to move the piston valve 18 as compared with the second embodiment. Instead, a dedicated actuator 42 is provided. In this embodiment, the actuator 42 is connected to the piston valve 18, and the piston valve 18 is moved in the same direction as the actuator 42 extends and contracts in the compressor axial direction. As the actuator 42, for example, an electromagnetic actuator or the like can be used, and an actuator that can arbitrarily control the movement of the piston valve 18 is preferable. Since other structures conform to the structure of the compressor 31 shown in FIG. 7, the same reference numerals as those shown in FIG. However, the structure provided with the dedicated actuator 42 can also be applied to the first embodiment shown in FIG.

  Thus, instead of using the differential pressure between the crank pressure and the suction pressure, by providing the dedicated actuator 42, the piston valve 18 can be moved in an arbitrary direction at an arbitrary timing by the operation of the actuator 42 by an external signal. Therefore, the degree of freedom of control is greatly increased. The other actions and effects of the movement of the piston valve 18 are the same as in the second embodiment. In the third embodiment, the actuator 42 and the piston valve 18 are configured as separate members. However, a structure equivalent to the piston valve 18 is configured in the actuator 42 and configured as an integrated actuator member. It is also possible.

  The present invention is applicable to any compressor as long as it is a multi-cylinder compressor having a swash plate.

It is a longitudinal cross-sectional view of the swash plate type compressor which concerns on Example 1 of this invention. FIG. 2 is an enlarged longitudinal sectional view of a main part of the swash plate compressor in FIG. 1. The piston valve in the swash plate type compressor of FIG. 1 is shown, (A) is a top view, (B) is sectional drawing, (C) is a side view, (D) is a bottom view. It is a fragmentary longitudinal cross-section which shows one operation state of the swash plate type compressor of FIG. It is a fragmentary longitudinal cross-section which shows another operating state of the swash plate type compressor of FIG. FIG. 2 is a schematic horizontal and vertical sectional view showing an operation example of each cylinder of the swash plate compressor of FIG. 1. It is a longitudinal cross-sectional view of the swash plate type compressor which concerns on Example 2 of this invention. It is a longitudinal cross-sectional view of the swash plate type compressor which concerns on Example 3 of this invention. It is a longitudinal cross-sectional view of the conventional swash plate type compressor.

Explanation of symbols

1, 31, 41 Swash plate compressor 2 Refrigeration circuit 3 Cylinder block 4 Cylinder bore 5 Piston 6 Compressor drive shaft 7 Swash plate (variable angle)
8 Shoe 9 Rotor 10 Hinge mechanism 11 Cylinder head 12 Discharge chamber 13 Suction chamber 14 Crank chamber 15 Control valve 16 Axial adjustment screw 17 Piston valve cylinder 18 Piston valve 19 Spring 20 Communication passage 21 Piston valve groove 22 Passage 32 to the suction chamber Swash plate (fixed angle)
42 Actuator

Claims (7)

  A plurality of cylinder bores are radially arranged in the cylinder block, and pistons are reciprocally inserted into the cylinder bores, respectively. Is a swash plate compressor provided with a control valve capable of adjusting the crank chamber pressure between the discharge chamber and the crank chamber, and provided with a passage capable of communicating between the plurality of cylinder bores. In addition, a swash plate compressor characterized in that means for controlling communication / non-communication in the passage is provided.   The swash plate is a swash plate whose angle with respect to the compressor drive shaft is variable, and a piston valve cylinder is formed at the center of the cylinder block in the compressor radial direction, and the compressor axial direction is within the piston valve cylinder. A piston valve is movably provided in the cylinder, and the piston valve is urged toward the crank chamber side by the urging means, and is connected to the piston valve cylinder with respect to several cylinder bores in all the cylinder bores. The piston valve groove is provided on the outer peripheral surface of the piston valve, and when the piston valve groove and the communication path are communicated by the movement of the piston valve, the cylinder bores communicate with each other. By configuring as above, a passage capable of communicating between the cylinder bores and communication / non-communication in the passage are provided. Wherein the Gosuru means is configured, the swash plate type compressor according to claim 1.   The swash plate is composed of a swash plate whose angle with respect to the compressor drive shaft is fixed, and a piston valve cylinder is formed at the center of the cylinder block in the radial direction of the compressor, and the axial direction of the compressor is within the piston valve cylinder. A piston valve is movably provided in the cylinder, and the piston valve is urged toward the crank chamber side by the urging means, and is connected to the piston valve cylinder with respect to several cylinder bores in all the cylinder bores. The piston valve groove is provided on the outer peripheral surface of the piston valve, and when the piston valve groove and the communication path are communicated by the movement of the piston valve, the cylinder bores communicate with each other. By configuring as above, a passage capable of communicating between the cylinder bores and communication / non-communication in the passage are provided. Wherein the Gosuru means is configured, the swash plate type compressor according to claim 1.   The swash plate compression according to claim 2 or 3, wherein the piston valve is moved by a differential pressure between a crank chamber pressure introduced from the crank chamber side and a suction pressure introduced from the suction chamber side. Machine.   The swash plate compressor according to claim 2 or 3, wherein the piston valve is moved by a dedicated actuator.   The swash plate compressor according to any one of claims 2 to 5, wherein a piston ring is attached to the piston valve.   The swash plate compressor according to any one of claims 2 to 6, wherein the piston valve is coated with a resin coating.

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