JP2019178647A - Piston type compressor - Google Patents

Abstract

To provide a piston type compressor capable of appropriately changing a flow rate of a coolant that is discharged from a compression chamber to a discharge chamber, and easily performing OFF operation.SOLUTION: In a compressor, a communication angle around a shaft center O where a first communication path 22 and a second communication path 41 communicate with each other is changed per rotation of a drive shaft 3 in accordance with a position of a rotor 11 in a direction of a shaft center O and a flow rate of a coolant discharged from a compression chamber 45 to a discharge chamber 29 is changed. In the compressor, as energization chambers, a first energization chamber 37 and a second energization chamber 43 consist of the drive shaft 3 and the rotor 11. The coolant compressed in the compression chamber 45 is introduced through the first and second communication paths 22 and 41 into the first and second energization chambers 37 and 43. In the second energization chamber 43, a first coil spring 47 is provided as an energization member. In a discharge path 29a, a check valve 20 is provided. The check valve 20 causes a coolant that exceeds a preset pressure, to be discharges from the discharge chamber 29 to an external coolant circuit 100.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a piston type compressor.

  FIG. 18 of Patent Document 1 discloses a conventional piston type compressor (hereinafter simply referred to as a compressor). The compressor includes a housing, a drive shaft, a fixed swash plate, a plurality of pistons, a discharge valve, a control valve, and a rotating body.

  The housing has a cylinder block. A plurality of cylinder bores are formed in the cylinder block, and a first communication path communicating with the cylinder bore is formed. Further, the housing is formed with a swash plate chamber that functions as a suction chamber, a discharge chamber, a control pressure chamber, and a shaft hole. The swash plate chamber communicates with the shaft hole.

  The drive shaft is rotatably supported in the shaft hole. The fixed swash plate can be rotated in the swash plate chamber by the rotation of the drive shaft. The fixed swash plate has a constant inclination angle with respect to a plane perpendicular to the drive shaft. Each piston forms a compression chamber in each cylinder bore. Each piston is connected to a fixed swash plate. A reed valve type discharge valve is provided between the compression chamber and the discharge chamber to discharge the refrigerant in the compression chamber to the discharge chamber. The control valve controls the control pressure in the control pressure chamber.

  The rotating body is provided on the outer peripheral surface of the drive shaft. The rotating body can rotate integrally with the drive shaft in the shaft hole and can move relative to the drive shaft in the axial direction of the drive shaft based on the differential pressure between the control pressure and the suction pressure in the swash plate chamber. ing. Moreover, the 2nd communicating path is formed in the outer peripheral surface of a rotary body. The second communication path intermittently communicates with the first communication path as the drive shaft rotates. Further, a space is formed inside the rotating body by the drive shaft and the rotating body, and an urging member is provided in this space. The urging member urges the rotating body in a direction in which the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber decreases.

  In this compressor, the drive shaft rotates and each piston reciprocates in each cylinder bore, so that in each compression chamber, a suction stroke for sucking refrigerant, a compression stroke for compressing the sucked refrigerant, and a compressed refrigerant And a discharge stroke for discharging the liquid. In this compressor, the communication angle around the shaft center at which each first communication path communicates with the second communication path changes per rotation of the drive shaft depending on the position in the shaft hole of the rotating body. Thereby, in this compressor, it is possible to change the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber.

JP-A-5-306680

  However, in the above compressor, even if the control valve adjusts the control pressure to move the rotor in the axial direction so that the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber is minimized, It is difficult to move to a position where the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber is minimized. This is because, in this compressor, since the rotating body moves based on the differential pressure between the control pressure and the suction pressure, the rotating body moves to a position where the flow rate of refrigerant discharged from the compression chamber to the discharge chamber is minimized. This is because the control pressure and the suction pressure are easily balanced during the process, and the rotating body does not move. For this reason, in this compressor, since it is difficult to reduce the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber to the minimum, the refrigerant in the discharge chamber is transferred to the external refrigerant circuit outside the compressor while rotating the drive shaft. It is difficult to perform an operation state in which no discharge is performed (hereinafter, such an operation state is referred to as an OFF operation).

  Therefore, in this compressor, it is conceivable to move the rotating body to a position where the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber is minimized by increasing the urging force of the urging member. However, in this case, when the rotating body is moved in the axial direction so that the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber increases, the resistance force due to the urging force increases. For this reason, it becomes difficult to suitably increase the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber.

  The present invention has been made in view of the above-described conventional situation, and is capable of suitably changing the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber, and is a piston type compression that facilitates the OFF operation. Providing a machine is an issue to be solved.

The piston type compressor of the present invention has a cylinder block in which a plurality of cylinder bores are formed, a suction chamber, a discharge chamber, a control pressure chamber, a housing in which a shaft hole is formed,
A drive shaft rotatably supported in the shaft hole;
A fixed swash plate that is rotatable in the housing by rotation of the drive shaft and has a constant inclination angle with respect to a plane perpendicular to the drive shaft;
A piston that forms a compression chamber in each cylinder bore and is connected to the fixed swash plate;
A discharge valve for discharging the refrigerant in the compression chamber to the discharge chamber;
A control valve capable of controlling the control pressure in the control pressure chamber;
The drive shaft is provided to rotate integrally with the drive shaft, and is movable relative to the drive shaft in the axial direction of the drive shaft based on a differential pressure between the control pressure and the suction pressure in the suction chamber. With a rotating body,
The cylinder block is formed with a first communication path communicating with the cylinder bore,
The rotating body is formed with a second communication path that intermittently communicates with the first communication path as the drive shaft rotates.
According to the position of the rotating body in the axial direction, the communication angle around the axial center where the first communication path and the second communication path communicate with each other per rotation of the drive shaft is changed, A piston type compressor in which the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber changes,
The drive shaft and the rotating body are configured, and the refrigerant compressed in the compression chamber is introduced from the compression chamber through the first communication passage and the second communication passage, and the compression chamber supplies the discharge chamber. A biasing chamber that biases the rotating body in a direction in which the flow rate of the discharged refrigerant decreases;
A biasing member that is provided in the biasing chamber and biases the rotating body in a direction in which the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber decreases;
A check valve is provided in a discharge passage between the discharge chamber and the external refrigerant circuit, and discharges refrigerant exceeding a set pressure from the discharge chamber to the external refrigerant circuit.

  In the piston type compressor of the present invention, when the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber is large, including the case where the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber is maximum, The refrigerant pressure exceeds the set pressure. For this reason, the refrigerant in the discharge chamber is discharged to the external refrigerant circuit. On the other hand, when the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber is small, including the case where the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber is the minimum, the refrigerant pressure in the discharge chamber becomes the set pressure. Below. For this reason, the refrigerant in the discharge chamber is not discharged to the external refrigerant circuit. Thus, this compressor can be turned off.

  Here, in this compressor, the refrigerant compressed in the compression chamber is introduced from the compression chamber into the biasing chamber via the first communication passage and the second communication passage. The pressure of the refrigerant compressed in the compression chamber is higher than the control pressure. For this reason, the urging chamber urges the rotating body in a direction in which the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber decreases with the urging member by the pressure of the introduced refrigerant. For this reason, the rotating body can be suitably moved in a direction in which the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber decreases in the axial direction. Thereby, in this compressor, it becomes possible to suitably reduce the flow rate of the refrigerant until the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber is minimized. Thereby, since the pressure of the refrigerant in the discharge chamber is suitably lower than the set pressure, this compressor can easily perform the OFF operation.

  Thus, in this compressor, it is not necessary to excessively increase the urging force of the urging member to urge the rotating body in a direction in which the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber decreases. For this reason, when the rotating body is moved in a direction in which the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber increases in the axial direction, the biasing force of the biasing member is unlikely to become resistance. Further, the urging force of the urging chamber due to the refrigerant introduced into the urging chamber gradually decreases as the pressure inside the compressor is equalized by continuing the OFF operation or stopping the operation of the compressor. For these reasons, it is easy to suitably increase the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber when returning from the OFF operation or operation stop state to the normal operation state.

  Therefore, the piston type compressor of the present invention can suitably change the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber and can easily perform the OFF operation.

  The compressor of the present invention preferably includes an auxiliary biasing member that is provided in the control pressure chamber and biases the rotating body in a direction in which the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber increases. In this case, since the rotating body easily moves in the direction in which the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber increases, the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber can be suitably increased. It becomes possible.

  In the compressor of the present invention, the biasing member may be a coil spring extending in the axial direction. And it is also preferable that a coil spring is latched by the rotating body at one end side, and is latched by the drive shaft at the other end side. In this case, when the rotating body is biased in a direction in which the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber decreases, the coil spring extends beyond the free length and is discharged from the compression chamber to the discharge chamber. When increasing the flow rate of the refrigerant, the urging force of the coil spring that attempts to return to the free length acts on the rotating body. For this reason, it becomes easy to increase the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber. The free length refers to the length of the coil spring in a state where no load is applied.

  In the compressor according to the present invention, the drive shaft includes a first passage communicating with the suction chamber, a second passage communicating with the second communication passage, and a third passage connecting the first passage and the second passage. Is preferably formed. In this case, the refrigerant can be suitably sucked from the suction chamber into the compression chamber through the first to third passages and the second communication passage.

  The piston type compressor of the present invention can suitably change the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber, and can easily perform the OFF operation.

FIG. 1 is a cross-sectional view of the piston compressor according to the first embodiment at the maximum flow rate. FIG. 2 is a cross-sectional view of the piston-type compressor according to the first embodiment at a minimum flow rate. FIG. 3 is an enlarged cross-sectional view of a main part illustrating the drive shaft, the rotating body, and the like at the maximum flow rate in the piston compressor of the first embodiment. FIG. 4 is an enlarged cross-sectional view of a main part illustrating the drive shaft, the rotating body, and the like at the minimum flow rate in the piston compressor of the first embodiment. FIG. 5 is an enlarged cross-sectional view of a main part illustrating a drive shaft, a rotating body, and the like at the minimum flow rate in the piston type compressor of the second embodiment.

  Embodiments 1 and 2 embodying the present invention will be described below with reference to the drawings. These compressors are single-head piston compressors. These compressors are mounted on a vehicle and constitute a refrigeration circuit of an air conditioner.

Example 1
As shown in FIGS. 1 and 2, the compressor of the first embodiment includes a housing 1, a drive shaft 3, a fixed swash plate 5, a plurality of pistons 7, a valve forming plate 9, a rotating body 11, A control valve 13 and a suction mechanism 15 are provided. The valve forming plate 9 is an example of the “discharge valve” in the present invention.

  The housing 1 includes a front housing 17, a rear housing 19, and a cylinder block 21. In the present embodiment, the front-rear direction of the compressor is defined with the side where the front housing 17 is located as the front side of the compressor and the side where the rear housing 19 is located as the rear side of the compressor. 1 and 2 is defined as the upper side of the compressor, and the lower side of the page is defined as the lower side of the compressor to define the vertical direction of the compressor. In FIG. 3 and subsequent figures, the front-rear direction and the vertical direction are displayed in correspondence with FIGS. In addition, the front-back direction in an Example is an example, and the attitude | position of the compressor of this invention is suitably changed according to the vehicle etc. which are mounted.

  The front housing 17 has a front wall 17a extending in the radial direction and a peripheral wall 17b that is integral with the front wall 17a and extends rearward from the front wall 17a in the direction of the axis O of the drive shaft 3, and is substantially cylindrical. It has a shape. A first boss portion 171, a second boss portion 172, and a first shaft hole 173 are formed in the front wall 17a. The first boss portion 171 protrudes forward in the direction of the axis O. A shaft seal device 25 is provided in the first boss portion 171. The second boss portion 172 protrudes rearward in the direction of the axis O in a swash plate chamber 31 described later. The first shaft hole 173 passes through the front wall 17a in the direction of the axis O. A suction port 174 is formed in the peripheral wall 17b. The suction port 174 is connected to the evaporator 102 provided outside the compressor via the pipe 101.

  A control pressure chamber 27, a discharge chamber 29, and a discharge passage 29a are formed in the rear housing 19. The control pressure chamber 27 is located on the center side of the rear housing 19. The discharge chamber 29 is formed in an annular shape and is located on the outer peripheral side of the control pressure chamber 27. The discharge passage 29 a communicates with the discharge chamber 29, extends from the rear housing 19 in the direction of the axis O and opens to the outside of the rear housing 19. A portion of the discharge passage 29a that opens to the outside of the rear housing 19 is a discharge port 29b. The discharge passage 29a is connected to a condenser 103 provided outside the compressor via a pipe 105. The evaporator 102 and the condenser 103 are connected via a pipe 106 and an expansion valve 104. The evaporator 102, the condenser 103, the expansion valve 104, and the pipes 101, 105, and 106 constitute an external refrigeration circuit 100.

  A check valve 20 is provided in the discharge passage 29a. That is, the check valve 20 is disposed between the discharge chamber 29 and the external refrigeration circuit 100, more specifically, between the discharge chamber 29 and the condenser 103. The check valve 20 prevents refrigerant gas from flowing into the discharge chamber 29 from the external refrigeration circuit 100 side. On the other hand, the check valve 20 is opened to discharge refrigerant gas from the discharge chamber 29 toward the condenser 103. A predetermined set pressure for opening the check valve 20 is set in advance. The set pressure can be set as appropriate.

  The cylinder block 21 is located between the front housing 17 and the rear housing 19. A plurality of cylinder bores 21 a are formed in the cylinder block 21. The cylinder bores 21a are arranged at equiangular intervals in the circumferential direction. Each cylinder bore 21a extends in the axis O direction. The number of cylinder bores 21a can be designed as appropriate.

  The cylinder block 21 is joined to the front housing 17, thereby forming a swash plate chamber 31 between the front wall 17 a and the peripheral wall 17 b of the front housing 17. The swash plate chamber 31 communicates with the suction port 174. Therefore, the low-pressure refrigerant gas that has passed through the evaporator 102 is sucked into the swash plate chamber 31 through the suction port 174. Thereby, the swash plate chamber 31 also functions as the “suction chamber” of the present invention.

  The cylinder block 21 is formed with second shaft holes 23, support walls 24, and the same number of first communication passages 22 as the cylinder bores 21a. The second shaft hole 23 is located on the center side of the cylinder block 21 and extends in the direction of the axis O. The rear side of the second shaft hole 23 is positioned in the control pressure chamber 27 by the cylinder block 21 being joined to the rear housing 19 via the valve forming plate 9. Thus, the rear side of the second shaft hole 23 communicates with the control pressure chamber 27.

  The support wall 24 is located on the center side of the cylinder block 21 and in front of the second shaft hole 23. The second shaft hole 23 is partitioned from the swash plate chamber 31 by the support wall 24. The support wall 24 is provided with a third shaft hole 240 and a throttle passage 241. The third shaft hole 240 is coaxial with the first shaft hole 173 and penetrates the support wall 24 in the direction of the axis O. The first to third shaft holes 173, 23, and 240 are examples of the “shaft hole” in the present invention.

  The throttle passage 241 passes through the support wall 24 in the direction of the axis O at a position different from the third shaft hole 240. Thereby, the throttle passage 241 makes the front side of the second shaft hole 23 communicate with the swash plate chamber 31.

  Each first communication passage 22 extends in the radial direction of the cylinder block 21 and is connected to each cylinder bore 21 a and the second shaft hole 23. Thus, each cylinder bore 21 a communicates with the second shaft hole 23 through each first communication path 22.

  The valve forming plate 9 is provided between the rear housing 19 and the cylinder block 21. The rear housing 19 and the cylinder block 21 are joined via the valve forming plate 9.

  The valve forming plate 9 includes a valve plate 91, a discharge valve plate 92, and a retainer plate 93. The valve plate 91 has the same number of discharge holes 910 as the cylinder bore 21a. Each cylinder bore 21 a communicates with the discharge chamber 29 through each discharge hole 910.

  The discharge valve plate 92 is provided on the rear surface of the valve plate 91. The discharge valve plate 92 is provided with the same number of discharge leads 92 a as the discharge holes 910. Each discharge reed valve 92a can open and close each discharge hole 910 by elastic deformation. The retainer plate 93 is provided on the rear surface of the discharge valve plate 92. The retainer plate 93 regulates the maximum opening of each discharge reed valve 92a.

  The drive shaft 3 extends from the front side of the compressor toward the rear side in the direction of the axis O. The drive shaft 3 has a screw portion 3a, a first diameter portion 3b, and a second diameter portion 3c. The threaded portion 3 a is located at the front end of the drive shaft 3. The drive shaft 3 is connected to a power source such as an engine or a motor (not shown) via the screw portion 3a. That is, the compressor is a so-called clutchless mechanism that is connected to a power source without using a clutch mechanism. Note that the compressor and the power source may be coupled via a clutch mechanism.

  The first diameter portion 3b is continuous with the rear end of the screw portion 3a and extends in the direction of the axis O. The second diameter portion 3c is continuous with the rear end of the first diameter portion 3b and extends in the direction of the axis O. The second diameter portion 3c has a smaller diameter than the first diameter portion 3b. Thereby, the step part 3d is formed between the 1st diameter part 3b and the 2nd diameter part 3c.

  The drive shaft 3 is formed with a first passage 30a, a second passage 30b, and a third passage 30c. The 1st channel | path 30a is formed in the 1st diameter part 3b, is extended in the radial direction of the 1st diameter part 3b, and is opened to the outer peripheral surface of the 1st diameter part 3b. The second passage 30b is formed in the second diameter portion 3c, extends in the radial direction of the second diameter portion 3c, and opens to the outer peripheral surface of the second diameter portion 3c. Here, the 2nd channel | path 30b is formed in the long hole shape extended in the axial center O direction. The third passage 30c is formed from the first diameter portion 3b to the second diameter portion 3c, and extends in the direction of the axis O. The third passage 30c connects the first passage 30a and the second path 30b. The rear end of the third passage 30c extends to the rear end of the second diameter portion 3c, that is, the rear end of the drive shaft 3.

  A sealing member 33 is press-fitted at the rear end of the third passage 30c. Thereby, the sealing member 33 is fixed to the second diameter portion 3 c and is integrated with the drive shaft 3.

  The drive shaft 3 is rotatably inserted into the housing 1 while the first diameter portion 3b is supported by the first shaft hole 173 and the third shaft hole 240. Thereby, the first diameter portion 3 b is rotatable in the swash plate chamber 31. Further, the second diameter portion 3 c is located in the second shaft hole 23 and is rotatable in the second shaft hole 23. Further, the drive shaft 3 is inserted through the shaft seal device 25 in the first boss portion 171. Thereby, the shaft seal device 25 seals between the inside of the housing 1 and the outside of the housing 1.

  The fixed swash plate 5 is press-fitted into the first diameter portion 3 b of the drive shaft 3 and is disposed in the swash plate chamber 31. As a result, the fixed swash plate 5 can be rotated together with the drive shaft 3 in the swash plate chamber 31 by the rotation of the drive shaft 3. Here, the fixed swash plate 5 has a constant inclination angle with respect to a plane perpendicular to the drive shaft 3. In the swash plate chamber 31, a thrust bearing 35 is provided between the second boss portion 172 and the fixed swash plate 5.

  The fixed swash plate 5 is formed with a connection path 5 a that extends in the radial direction and opens into the swash plate chamber 31. The connection path 5a communicates with the first path 30a. As a result, the first to third passages 30 a to 30 c communicate with the swash plate chamber 31.

  Each piston 7 is accommodated in each cylinder bore 21a. A compression chamber 45 is formed in each cylinder bore 21 a by each piston 7 and the valve forming plate 9.

  Each piston 7 has an engaging portion 7a. In each engagement portion 7a, hemispherical shoes 8a and 8b are provided. The pistons 7 are connected to the fixed swash plate 5 by these shoes 8a and 8b. Thereby, the shoes 8 a and 8 b function as a conversion mechanism that converts the rotation of the fixed swash plate 5 into the reciprocating motion of each piston 7. Therefore, each piston 7 can reciprocate in the cylinder bore 21 a between the top dead center of the piston 7 and the bottom dead center of the piston 7. Hereinafter, the top dead center and the bottom dead center of each piston 7 will be referred to as the top dead center and the bottom dead center, respectively.

  As shown in FIGS. 3 and 4, the rotating body 11 is formed in a substantially cylindrical shape having an outer peripheral surface 11 a, a recess 11 b, a front surface 111, a rear surface 112, and a protruding portion 113. The recess 11b extends forward in the direction of the axis O from the bottom wall 110 side, and is open to the front surface 111. The rotating body 11 is spline-coupled to the outer peripheral surface of the second diameter portion 3c in a state where the second diameter portion 3c of the drive shaft 3 is inserted into the recess 11b. Thus, the rotating body 11 is attached to the drive shaft 3 and disposed in the second shaft hole 23, and can rotate integrally with the drive shaft 3 in the second shaft hole 23. 3 and 4, the external refrigerant circuit 100 is not shown for ease of explanation. The same applies to FIG. 5 described later.

  By disposing the rotating body 11 in the second shaft hole 23, a first urging chamber 37 is defined in the second shaft hole 23. The first biasing chamber 37 is configured by the inner peripheral surface of the second shaft hole 23, the support wall 24, the drive shaft 3, and the front surface 111 of the rotating body 11. As described above, since the front side of the second shaft hole 23 communicates with the swash plate chamber 31 through the throttle passage 241, the first biasing chamber 37 communicates with the swash plate chamber 31 through the throttle passage 241. Thus, the suction pressure acts on the front surface 111 of the rotating body 11.

  On the other hand, the rear surface 112 faces the control pressure chamber 27. Further, the protruding portion 113 protrudes rearward from the rear surface 112, that is, toward the control pressure chamber 27. As a result, a control pressure acts on the rear surface 112 and the protruding portion 113.

  Thus, the rotating body 11 can move in the second shaft hole 23 in the axial center O direction, that is, in the second shaft hole 23 in the front-rear direction with respect to the drive shaft 3 by the differential pressure between the suction pressure and the control pressure. It has become. The suction pressure and the control pressure will be described later.

  Moreover, the 2nd energizing chamber 43 is divided in the recessed part 11b by inserting the 2nd diameter part 3c in the recessed part 11b. The second urging chamber 43 is configured by the inner peripheral surface of the recess 11b, the bottom wall 110 of the recess 11b, and the rear end of the second diameter portion 3c. The first urging chamber 37 and the second urging chamber 43 are examples of the “urging chamber” of the present invention. Here, since the sealing member 33 is fixed to the second diameter portion 3c, the second urging chamber 43 is not in communication with the first to third passages 30a to 30c. A first coil spring 47 is provided in the second urging chamber 43. The first coil spring 47 is an example of the “biasing member” in the present invention. The first coil spring 47 extends in the direction of the axis O and is in contact with the bottom wall 110 and the second diameter portion 3c. Accordingly, the first coil spring 47 biases the rotating body 11 toward the rear side in the direction of the axis O.

  On the other hand, a second coil spring 48 is provided in the control pressure chamber 27. The second coil spring 48 is an example of the “auxiliary biasing member” in the present invention. The second coil spring 48 extends in the direction of the axis O and is in contact with the wall surface of the control pressure chamber 27, that is, the rear housing 19 and the rear surface 112 of the rotating body 11. Accordingly, the second coil spring 48 biases the rotating body 11 toward the front side in the direction of the axis O. Here, the biasing force of the second coil spring 48 is set smaller than the biasing force of the first coil spring 47.

  Further, the rotating body 11 is formed with a second communication passage 41 and an introduction passage 44. The second communication path 41 includes a first path 41a and a main body path 41b. The first path 41a extends in the radial direction of the rotating body 11 and communicates with the second path 30b. Here, since the second passage 30b has a long hole shape extending in the direction of the axis O, even if the rotating body 11 moves in the direction of the axis O in the second shaft hole 23, the first path 41a and the second passage 30b. The communication area with the two passages 30b is constant.

  The main body passage 41b is recessed in the outer peripheral surface 11a and communicates with the first path 41a. The main body passage 41b is formed on the outer peripheral surface 11a so as to extend from the approximate center in the front-rear direction of the rotating body 11 toward the front side. Although not shown in detail, the main body passage 41b is gradually formed larger in the circumferential direction of the outer peripheral surface 11a as it goes to the front side of the rotating body 11. In other words, the first portion 411 formed small in the circumferential direction of the outer peripheral surface 11a is positioned on the rear end side of the main body passage 41b, and the second portion 412 formed large in the circumferential direction of the outer peripheral surface 11a is formed in the main body passage 41b. It is located on the front end side. The shape of the main body passage 41b can be designed as appropriate.

  The main body passage 41 b is intermittently communicated with each first communication passage 22 by the rotation of the drive shaft 3 and the rotation of the rotating body 11 in the second shaft hole 23. As a result, the communication angle around the axis O that communicates with each first communication path 22 changes per rotation of the drive shaft 3 in the main body passage 41b depending on the position of the rotating body 11 in the second shaft hole 23. Hereinafter, the communication angle around the axis O where the first communication passage 22 and the main body passage 41b communicate with each other per rotation of the drive shaft 3 is simply referred to as a communication angle.

  The introduction passage 44 communicates with the second urging chamber 43, extends in the direction of the axis O, and opens to the front surface 111. Thus, the introduction passage 44 allows the second urging chamber 43 and the first urging chamber 37 to communicate with each other, and thus the second urging chamber 43 and the second shaft hole 23. The introduction passage 44 has a larger opening area than the throttle passage 241. 1 to 4, the shapes of the throttle passage 241 and the introduction passage 44 are exaggerated for ease of explanation. The same applies to FIG. 5 described later.

  As shown in FIGS. 1 and 2, the control valve 13 is provided in the rear housing 19. The control valve 13 is connected to the swash plate chamber 31 by the first control passage 13a. The control valve 13 is connected to the discharge chamber 29 by the second control passage 13b. Further, the control valve 13 is connected to the control pressure chamber 27 by the third control passage 13c. The first control passage 13 a is formed in the rear housing 19 and the cylinder block 21. The second and third control passages 13 b and 13 c are formed in the rear housing 19. The control valve 13 adjusts the valve opening degree by sensing the suction pressure that is the pressure of the refrigerant gas in the swash plate chamber 31. The control valve 13 causes a part of the refrigerant gas in the discharge chamber 29 to flow through the control pressure chamber 27. At this time, the control valve 13 controls the discharge pressure that is the pressure of the refrigerant gas in the discharge chamber 29 to the control pressure that is the pressure of the refrigerant gas in the control pressure chamber 27. Further, the control pressure chamber 27 can reduce the control pressure by a bleed passage (not shown).

  The suction mechanism 15 includes a connection path 5 a, first to third paths 30 a to 30 c, a second communication path 41, and each first communication path 22. The suction mechanism 15 sucks the refrigerant gas in the swash plate chamber 31 into each compression chamber 45. That is, the refrigerant gas in the swash plate chamber 31 reaches the first path 41 a of the second communication path 41 through the connection path 5 a and the first to third paths 30 a to 30 c. Then, the refrigerant gas reaching the first path 41 a is sucked into the compression chambers 45 through the main body passage 41 b and the first communication passages 22.

  In the compressor configured as described above, the fixed swash plate 5 rotates in the swash plate chamber 31 as the drive shaft 3 rotates. As a result, each piston 7 reciprocates between the top dead center and the bottom dead center in each cylinder bore 21a, and in each compression chamber 45, a suction stroke for sucking refrigerant gas from the swash plate chamber 31 and a suction stroke are performed. The compression stroke for compressing the refrigerant gas and the discharge stroke for discharging the compressed refrigerant gas are repeated. In the discharge stroke, the refrigerant gas is discharged into the discharge chamber 29 by the valve forming plate 9. Thereafter, the refrigerant gas in the discharge chamber 29 is discharged to the condenser 103 through the discharge port 29 a and the check valve 20.

  In the compressor, the rotary body 11 is moved in the direction of the axis O in the second shaft hole 23 during the suction stroke and the like, so that each compression chamber 45 is rotated per one rotation of the drive shaft 3. The flow rate of the refrigerant gas discharged from the discharge chamber 29 to the discharge chamber 29 can be changed.

  Specifically, when the flow rate of the refrigerant gas discharged from each compression chamber 45 to the discharge chamber 29 is increased, the control valve 13 increases the control pressure of the control pressure chamber 27. Thereby, the variable differential pressure that is the differential pressure between the control pressure and the suction pressure is increased.

  For this reason, when the control pressure which acts on the rear surface 112 and the protrusion part 113 of the rotary body 11 becomes large, the rotary body 11 resists the urging | biasing force of the 1st coil spring 47, and is 2nd from the state shown in FIG. The inside of the shaft hole 23 starts to move forward in the direction of the axis O. At this time, the biasing force of the second coil spring 48 assists the forward movement of the rotating body 11. As a result, the second communication path 41 moves forward relative to each first communication path 22. Thereby, the main body passage 41b is in a state of communicating with each first communication passage 22 in a portion formed small in the circumferential direction of the outer peripheral surface 11a. For this reason, in this compressor, a communication angle becomes small gradually.

  Then, as the variable differential pressure becomes maximum, as shown in FIG. 3, the rotating body 11 is moved forward most in the second shaft hole 23 and comes into contact with the step portion 3d. Thereby, in the main body channel | path 41b, it will be in the state connected to each 1st communicating path 22 in the 1st site | part 411, and a communicating angle becomes the minimum.

  As described above, when the communication angle is minimized, the rotating body 11 is rotated, so that in the second communication passage 41, the main body passage 41 b passes through the compression chambers 45 from the top dead center to the bottom of the piston 7. Only when moving toward the point, it is in a state of communicating with each first communication path 22. Thereby, the refrigerant gas sucked into each compression chamber 45 is compressed when each compression chamber 45 is in a compression stroke. Thus, in this compressor, the flow rate of the refrigerant gas discharged from each compression chamber 45 to the discharge chamber 29 is maximized when each compression chamber 45 reaches the discharge stroke.

  Here, the flow of the refrigerant gas discharged from each compression chamber 45 to the discharge chamber 29 increases, including the case where the flow rate of the refrigerant gas discharged from each compression chamber 45 to the discharge chamber 29 is maximum. The pressure of the refrigerant gas in the chamber 29 exceeds the set pressure of the check valve 20. For this reason, the check valve 20 is opened, and the refrigerant gas in the discharge chamber 29 is discharged to the condenser 103.

  On the contrary, in this compressor, when the flow rate of the refrigerant gas discharged from each compression chamber 45 to the discharge chamber 29 is decreased, the control valve 13 decreases the control pressure in the control pressure chamber 27. Thereby, the variable differential pressure, which is the differential pressure between the control pressure and the suction pressure, is reduced.

  For this reason, the control pressure which acts on the rear surface 112 and the protrusion part 113 of the rotary body 11 becomes small, whereby the rotary body 11 is moved from the state shown in FIG. 3 to the second shaft hole 23 by the biasing force of the first coil spring 47. The inside starts to move backward in the direction of the axis O. At this time, although the biasing force of the second coil spring 48 acts on the rotating body 11, the biasing force of the second coil spring 48 is smaller than the biasing force of the first coil spring 47. For this reason, the urging force of the second coil spring 48 is unlikely to hinder the backward movement of the rotating body 11. Thus, the second communication passage 41 moves rearward relative to the first communication passage 22 as the rotating body 11 moves rearward. Thereby, the main body passage 41b is in a state of communicating with each first communication passage 22 at a portion that is largely formed in the circumferential direction of the outer peripheral surface 11a. For this reason, in this compressor, the communication angle gradually increases.

  Then, the variable differential pressure becomes smaller, and the rotating body 11 moves further backward in the second shaft hole 23, so that the main body passage 41b communicates with each first communication passage 22 in the vicinity of the second portion 412. It becomes a state and a communication angle becomes larger. In this way, by increasing the communication angle, the main body passage 41b can be used not only while each piston 7 moves in the compression chamber 45 from the top dead center toward the bottom dead center, Even while moving from the bottom dead center toward the top dead center to a certain extent, the first communication passages 22 are communicated with each other. As a result, a part of the refrigerant gas sucked into each compression chamber 45 while each piston 7 is moving from the top dead center toward the bottom dead center is transferred from the bottom dead center to the top dead center. When moving toward the center, the air is discharged to the upstream side of each compression chamber 45, that is, to the outside of each compression chamber 45 through each first communication passage 22 and second communication passage 41. As a result, the flow rate of the refrigerant gas compressed when each compression chamber 45 is in the compression stroke is reduced. Thus, in this compressor, the flow rate of the refrigerant gas discharged from each compression chamber 45 to the discharge chamber 29 when each compression chamber 45 enters the discharge stroke is reduced to a minimum.

  Thereby, in this compressor, the pressure of the refrigerant gas in the discharge chamber 29 is lower than the set pressure of the check valve 20. For this reason, the check valve 20 is closed, and the refrigerant gas in the discharge chamber 29 is not discharged to the condenser 103. Thus, this compressor is turned off.

  Here, in this compressor, when the check valve 20 is closed, refrigerant gas (hereinafter referred to as residual gas) lower than the set pressure remaining in each compression chamber 45 causes the first energizing chamber 37 and the second energizing chamber 37. It is introduced into the energizing chamber 43. Specifically, when the check valve 20 is closed, the residual gas is introduced into the first urging chamber 37 via the main passages 41 b of the first communication passages 22 and the second communication passages 41. Here, the first urging chamber 37 communicates with the swash plate chamber 31 through the throttle passage 241 and also communicates with the second urging chamber 43 through the introduction passage 44. For this reason, as shown by the black arrows in FIG. 4, the residual gas flows from the first energizing chamber 37 through the introduction passage 44 and is also introduced into the second energizing chamber 43. At this time, since the opening area of the introduction passage 44 is larger than that of the throttle passage 241, the residual gas introduced into the first urging chamber 37 is more likely to flow through the introduction passage 44 than through the throttle passage 241. It becomes easy to be introduced into the second urging chamber 43.

  In this way, in the process of being introduced into the first and second energizing chambers 37 and 43, the residual gas is decompressed, but the pressure of the residual gas is the flow rate of the refrigerant gas discharged from each compression chamber 45 to the discharge chamber 29. Is higher than the control pressure in the control pressure chamber 27 in a state where the pressure decreases to a minimum. For this reason, the insides of the first and second urging chambers 37 and 43 are higher in pressure than the inside of the control pressure chamber 27. Thereby, as shown by the white arrow in FIG. 4, the first and second urging chambers 37 and 43 urge the rotating body 11 together with the first coil spring 47 to the rear side of the compressor by the pressure of the residual gas. . For this reason, the rotating body 11 can suitably move rearward in the second shaft hole 23 until the protruding portion 113 contacts the wall surface of the control pressure chamber 27, that is, the rear housing 19. Then, the rotating body 11 moves most rearward in the second shaft hole 23 and the protrusion 113 contacts the rear housing 19, so that the main body passage 41 b communicates with each first communication passage 22 at the second portion 412. It becomes a state to do. As a result, the communication angle is maximized and the flow rate of the refrigerant gas discharged from each compression chamber 45 to the discharge chamber 29 is minimized.

  As described above, in this compressor, the rotating body 11 can be suitably moved to the rear in the second shaft hole 23 to a position where the flow rate of the refrigerant gas discharged from each compression chamber 45 to the discharge chamber 29 is minimized. it can. Thereby, in this compressor, it is possible to suitably reduce the flow rate of the refrigerant gas discharged from each compression chamber 45 to the discharge chamber 29 to the minimum. And since the flow rate of the refrigerant gas discharged from each compression chamber 45 to the discharge chamber 29 is minimized, the pressure of the refrigerant gas in the discharge chamber 29 is preferably in a state lower than the set pressure of the check valve 20. . For this reason, in this compressor, it is easy to perform OFF operation including maintenance of OFF operation.

  Thus, in this compressor, it is not necessary to excessively increase the biasing force of the first coil spring 47 to bias the rotating body 11 to the rear side of the compressor. For this reason, when increasing the flow rate of the refrigerant gas discharged from each compression chamber 45 to the discharge chamber 29, the urging force of the first coil spring 47 is unlikely to become resistance. Further, the urging force of the first and second urging chambers 37 and 43 due to the residual gas gradually decreases as the pressure inside the compressor is equalized by continuing the OFF operation or stopping the operation of the compressor. For this reason, in this compressor, it is easy to suitably increase the flow rate of the refrigerant gas discharged from each compression chamber 45 to the discharge chamber 29 when returning from the OFF operation state or the operation stop state to the normal operation state. Yes.

  Therefore, the compressor of the first embodiment can suitably change the flow rate of the refrigerant gas discharged from each compression chamber 45 to the discharge chamber 29 and can easily perform the OFF operation.

  Further, in this compressor, a second coil spring 48 is provided in the control pressure chamber 27, and the second coil spring 48 urges the rotating body 11 forward of the compressor. Thus, even when the first and second urging chambers 37 and 43 urge the rotating body 11 together with the first coil spring 47 to the rear side of the compressor due to the pressure of the residual gas, the rotating body 11 It is easy to move forward in the biaxial hole 23. Thus, in this compressor, it is possible to suitably increase the flow rate of the refrigerant gas from a state where the flow rate of the refrigerant gas discharged from each compression chamber 45 to the discharge chamber 29 is small, including the case of OFF operation. ing.

  Further, in this compressor, since the swash plate chamber 31 also functions as a suction chamber, it is not necessary to secure a space for the suction chamber in the housing 1, and the housing 1 can be downsized. Further, since the suction mechanism 15 includes the connection path 5a, the first to third paths 30a to 30c, the second communication path 41, and the first communication paths 22, the configuration of the suction mechanism 15 is simplified. Thus, the refrigerant gas can be suitably sucked from the swash plate chamber 31 into the compression chambers 45.

(Example 2)
As shown in FIG. 5, in the compressor of the second embodiment, in the rotating body 11, the first locking portion 110 a is formed on the bottom wall 110 of the recess 11 b. Further, a second locking portion 33 a is formed on the sealing member 33. The first locking portion 110a and the second locking portion 33a protrude into the second urging chamber 43 and face each other. In addition, the shape of the 1st latching | locking part 110a and the 2nd latching | locking part 33a can be designed suitably.

  In the second urging chamber 43, the first coil spring 47 is locked to the bottom wall 110 on the rear side through the first locking portion 110a and the second diameter portion on the front side through the second locking portion 33a. 3c, that is, locked to the drive shaft 3.

  Further, in this compressor, unlike the compressor of the first embodiment, the second coil spring 48 is not provided in the control pressure chamber 27. Other configurations of the compressor are the same as those of the compressor according to the first embodiment, and the same components are denoted by the same reference numerals and detailed description thereof is omitted.

  In this compressor, the rotating body 11 moves to the farthest rear in the second shaft hole 23, and the flow rate of the refrigerant gas discharged from each compression chamber 45 to the discharge chamber 29 is minimized, whereby the first coil spring 47. Will extend beyond the free length. Thereby, when increasing the flow rate of the refrigerant gas discharged from the compression chambers 45 to the discharge chambers 29, the urging force of the first coil spring 47 that attempts to return to the free length acts on the rotating body 11. That is, at this time, a biasing force that biases the rotating body 11 forward of the compressor acts. Thus, even in this compressor, the rotating body 11 can easily move forward in the second shaft hole 23 in increasing the flow rate of the refrigerant gas discharged from each compression chamber 45 to the discharge chamber 29. Moreover, in this compressor, since the 2nd coil spring 48 becomes unnecessary, a number of parts can be decreased. Other functions of this compressor are the same as those of the compressor of the first embodiment.

  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 can be appropriately modified and applied without departing from the spirit of the present invention. Needless to say.

  For example, you may comprise the compressor of Example 1, 2 as a double-headed piston type compressor.

  In the compressors of the first and second embodiments, the first coil spring 47 may be provided in the first biasing chamber 37. Further, the second urging chamber 43 may be omitted to configure the compressor.

  Furthermore, in the compressors of the first and second embodiments, the introduction passage 44 is formed in the rotating body 11, but the present invention is not limited thereto, and the introduction passage 44 may be formed on the outer peripheral surface of the second diameter portion 3c. Moreover, you may form the introduction channel | path 44 in the rotary body 11 and the outer peripheral surface of the 2nd diameter part 3c, respectively.

  In the compressors according to the first and second embodiments, the second communication passage 41 is configured only by the main body passage 41b, and the first energizing chamber is not formed by forming the connection passage 5a and the first to third passages 30a to 30c. The refrigerant gas in 37 may be sucked into the compression chambers 45 through the second communication passage 41 and the first communication passages 22.

  Furthermore, in the compressors of the first and second embodiments, the rotating body 11 moves rearward in the second shaft hole 23 in the direction of the axis O, so that the discharge chambers are discharged from the compression chambers 45 per rotation of the drive shaft 3. The flow rate of the refrigerant gas discharged to 29 may be increased.

  In the compressors of the first and second embodiments, the communication angle increases, so that the flow rate of the refrigerant gas discharged from each compression chamber 45 to the discharge chamber 29 per rotation of the drive shaft 3 increases, and the communication angle The flow rate of the refrigerant gas discharged from the respective compression chambers 45 to the discharge chambers 29 per rotation of the drive shaft 3 may be reduced by reducing.

  Further, in the compressors of the first and second embodiments, instead of the shoes 8a and 8b, a swing plate is supported on the rear surface side of the fixed swash plate 5 via a thrust bearing, and the swing plate and each piston 7 are supported. A wobble type conversion mechanism that connects the two by a connecting rod may be adopted.

  In the compressors of the first and second embodiments, the suction port 174 may be formed in the rear housing 19 and a suction chamber communicating with the suction port 174 may be formed. In this case, the suction chamber and the swash plate chamber 31 may communicate with each other, or the suction chamber and the swash plate chamber 31 may not communicate with each other.

  Further, in the compressors of the first and second embodiments, the swash plate chamber 31 and the second shaft hole 23 are communicated with each other by the throttle passage 241. However, the present invention is not limited to this, and the swash plate chamber 31 and the second shaft hole 23 are throttled. The communication may be performed by a passage having an opening area larger than that of the passage 241.

  The present invention can be used for a vehicle air conditioner or the like.

DESCRIPTION OF SYMBOLS 1 ... Housing 3 ... Drive shaft 5 ... Fixed swash plate 7 ... Piston 9 ... Valve formation plate (discharge valve)
DESCRIPTION OF SYMBOLS 11 ... Rotating body 13 ... Control valve 20 ... Check valve 21a ... Cylinder bore 22 ... 1st communicating path 23 ... 2nd shaft hole (shaft hole)
27 ... Control pressure chamber 29 ... Discharge chamber 29a ... Discharge passage 30a ... First passage 30b ... Second passage 30c ... Third passage 31 ... Swash plate chamber (suction chamber)
37 ... 1st energizing room (energizing room)
41 ... 2nd communicating path 43 ... 2nd energizing chamber (energizing chamber)
45 ... Compression chamber 47 ... First coil spring (biasing member)
48 ... Second coil spring (auxiliary biasing member)
DESCRIPTION OF SYMBOLS 100 ... External refrigerant circuit 173 ... 1st shaft hole (shaft hole)
240 ... third shaft hole (shaft hole)
O ... axis

Claims (4)

A housing having a cylinder block in which a plurality of cylinder bores are formed, a suction chamber, a discharge chamber, a control pressure chamber, and a shaft hole;
A drive shaft rotatably supported in the shaft hole;
A fixed swash plate that is rotatable in the housing by rotation of the drive shaft and has a constant inclination angle with respect to a plane perpendicular to the drive shaft;
A piston that forms a compression chamber in each cylinder bore and is connected to the fixed swash plate;
A discharge valve for discharging the refrigerant in the compression chamber to the discharge chamber;
A control valve capable of controlling the control pressure in the control pressure chamber;
The drive shaft is provided to rotate integrally with the drive shaft, and is movable relative to the drive shaft in the axial direction of the drive shaft based on a differential pressure between the control pressure and the suction pressure in the suction chamber. With a rotating body,
The cylinder block is formed with a first communication path communicating with the cylinder bore,
The rotating body is formed with a second communication path that intermittently communicates with the first communication path as the drive shaft rotates.
According to the position of the rotating body in the axial direction, the communication angle around the axial center where the first communication path and the second communication path communicate with each other per rotation of the drive shaft is changed, A piston type compressor in which the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber changes,
The drive shaft and the rotating body are configured, and the refrigerant compressed in the compression chamber is introduced from the compression chamber through the first communication passage and the second communication passage, and the compression chamber supplies the discharge chamber. A biasing chamber that biases the rotating body in a direction in which the flow rate of the discharged refrigerant decreases;
A biasing member that is provided in the biasing chamber and biases the rotating body in a direction in which the flow rate of the refrigerant discharged from the compression chamber to the discharge chamber decreases;
A piston type compression comprising a check valve provided in a discharge passage between the discharge chamber and an external refrigerant circuit, and discharging a refrigerant exceeding a set pressure from the discharge chamber to the external refrigerant circuit. Machine.   The piston type compression according to claim 1, further comprising an auxiliary biasing member provided in the control pressure chamber and biasing the rotating body in a direction in which a flow rate of a refrigerant discharged from the compression chamber to the discharge chamber increases. Machine. The biasing member is a coil spring extending in the axial direction,
The piston-type compressor according to claim 1, wherein the coil spring is locked to the rotating body at one end side and locked to the drive shaft at the other end side.   The drive shaft is formed with a first passage communicating with the suction chamber, a second passage communicating with the second communication passage, and a third passage connecting the first passage and the second passage. The piston type compressor according to any one of claims 1 to 3.

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