JP2009024558A - Coolant suction structure of fixed displacement piston type compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase start shock relaxing effect of a fixed displacement piston type compressor using a rotary valve. <P>SOLUTION: A first rotary valve 35 and a second rotary valve 36 are provided on a rotary shaft 21 with corresponding to cylinder blocks 11, 12. A cylinder 41 is formed as one unit on an inner wall surface 401 of a pedestal 40 formed on a rear housing 14. A valve element 42 made of magnetic body is fitted in an inside 411 of the cylinder 41 to define a pressure chamber 412. A permanent magnet 48 is fixed on the inner wall surface 401 in the inside 411 of the cylinder and the valve element 42 can be attracted by the permanent magnet 48. The valve element 42 is energized toward the permanent magnet 48 by spring force of a return spring 47. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is a fixed capacity type comprising a rotary valve having an introduction passage for introducing a refrigerant from a suction pressure region into a compression chamber defined in a cylinder bore by a piston, and the rotary valve rotates integrally with the rotary shaft. The present invention relates to a refrigerant suction structure in a piston type compressor.

  A piston type compressor using a rotary valve (see, for example, Patent Documents 2 and 4) is more effective than a piston type compressor using a reed valve type suction valve (see, for example, Patent Documents 1 and 3). There is little inhalation resistance when inhaling inhalation gas, and energy efficiency is excellent.

  As described in paragraph [0006] of Patent Document 2, when the compressor is started, the torque rapidly increases as the gas is compressed, and this is added to the vehicle engine (internal combustion engine) as a load. Therefore, a starting shock occurs in which the traveling speed of the vehicle decreases for a moment and the vehicle occupant feels a shock.

  In the piston compressor disclosed in Patent Document 2, a rotary valve that rotates integrally with the rotary shaft is provided so as to be movable in the axial direction of the rotary shaft, and the rotary valve has a pressure supplied to the control pressure chamber. Accordingly, the position of the rotating shaft in the axial direction can be changed. In addition, a bypass groove is formed in the rotary valve so that almost all cylinder bores can communicate with a suction port provided to the center of the cylinder block. The rotary valve is disposed at a position in the axial direction of the rotary shaft so that the bypass groove comes to a position where almost all cylinder bores can communicate with the suction port when the operation is stopped and started. Therefore, even when the piston performs an operation of compressing the gas in the cylinder bore at the time of activation, the gas in the cylinder bore returns to the suction port via the bypass groove, so that the activation shock does not occur.

  The clearance on the peripheral surface of the rotary valve needs to be as small as possible so that gas does not leak along the peripheral surface and the rotary valve can rotate. However, in the configuration in which the rotary valve can be moved in the axial direction of the rotary shaft, a clearance that enables the rotary valve to be moved in the axial direction of the rotary shaft is required, but such clearance management is very difficult. It is.

The piston compressor disclosed in Patent Document 3 is provided with a differential pressure sensing on / off valve that opens and closes by a differential pressure between a discharge pressure and a suction pressure. The differential pressure sensing on / off valve is interposed between the low-pressure refrigerant line for introducing refrigerant from the outside of the compressor and the suction chamber in the compressor, and when the compressor is started from a pressure balanced state, the differential pressure The sensing on / off valve is closed, and the flow of refrigerant from the outside of the compressor into the suction chamber is stopped. Thereby, the starting shock is relieved.
JP-A 64-88064 Japanese Patent Laid-Open No. 7-119631 JP 2000-145629 A JP 2006-83835 A

  However, in the compressor disclosed in Patent Document 3, refrigerant remains in the suction chamber even when the differential pressure sensing on / off valve is closed, and this residual refrigerant is sucked into the cylinder bore and compressed. Since the volume of the suction chamber is increased to suppress suction pulsation, a large amount of refrigerant is sucked into the cylinder bore when the differential pressure sensing on / off valve is closed, and the effect of reducing the starting shock is not sufficient. .

  An object of this invention is to raise the effect of starting shock mitigation.

  In the present invention, pistons are accommodated in a plurality of cylinder bores arranged around the rotation shaft, and the piston is interlocked with the rotation of the rotation shaft through a cam body integrated with the rotation shaft. A rotary valve having an introduction passage for introducing a refrigerant from a suction pressure region into a compression chamber defined in the cylinder bore by the piston, wherein the rotary valve rotates integrally with the rotary shaft, and the rotation The shaft is directed to a refrigerant suction structure in a fixed displacement piston compressor connected to an external drive source via a clutch, and the invention of claim 1 includes a suction pressure region in the compressor and an outlet of the introduction passage. Switching means for switching between a communicating state and a blocking state is provided, and the switching means communicates a suction pressure region in the compressor and an outlet of the introduction passage. A valve body that is switched between a position to be shut off and a position to be shut off, a return spring that returns the valve body from the communicating position to the shut-off position, and the valve body that is in the shutting position is communicated with each other by magnetic force. And a permanent magnet attracting from the position side to the blocking position side.

  The pressure in the introduction passage downstream from the valve body when the compressor is operating (when the rotating shaft is rotating) is greater than the pressure in the introduction passage when the compressor is not operating. Is also low. When the operation of the compressor is stopped, the valve body is in a position to be shut off. However, when the operation of the compressor is started, the pressure in the introduction passage downstream from the valve body is reduced and the valve body is shut off. Move from the position to communicate to the position to communicate. When the valve body is in the shut-off position, braking is applied at the start of movement of the valve body due to the magnetic force of the permanent magnet, and the time required for the transition from the shut-off position to the communicating position after the compressor starts operating Becomes longer. Therefore, when the operation of the compressor is started, the starting shock is alleviated. Since the communication between the suction pressure region in the compressor and the outlet of the introduction passage is blocked, the amount of refrigerant to be compressed is small when the switching means is in the blocked state, and the effect of reducing the start shock is high.

  When starting up, the pressure state is not stable, and when the communication between the suction pressure area in the compressor and the outlet of the introduction passage is started, the pressure state in the introduction passage changes greatly, and the valve body is likely to hunt It has become. However, in the present invention, by using the permanent magnet, the magnetic force acting on the valve body suddenly attracts the valve body from the communicating position side to the shut-off position side as the valve body moves away from the permanent magnet. Hunting of the valve body can be suppressed even if the pressure state fluctuates somewhat.

When the operation of the compressor is stopped, the valve body returns to the shut-off position by the spring force of the return spring. The use of the return spring is a simple configuration for returning the valve body to the position where it is shut off.
In a preferred example, the permanent magnet is fixed to a housing constituting the fixed displacement type piston compressor.

  When trying to move toward the position where the valve body in the blocking position communicates, the magnetic force of the permanent magnet attached to the housing brakes the movement of the valve body. The housing is suitable as a permanent magnet mounting location.

In a preferred example, the valve element contacts the permanent magnet when in the blocking position.
The configuration in which the valve body and the permanent magnet are brought into contact with each other is suitable for increasing the acting force of the magnet that is retained at the position where the valve body is blocked.

In a preferred example, the valve body and the permanent magnet are in surface contact.
The configuration in which the valve body and the permanent magnet are brought into surface contact is suitable for increasing the acting force of the magnet that keeps the valve body in a position where the valve body is blocked.

In a preferred example, when the switching means is in the shut-off state, the valve body is disposed at a position for shutting off the inlet of the introduction passage from the suction pressure region in the compressor.
Since the communication between the suction pressure region in the compressor and the inlet of the introduction passage is blocked, the amount of refrigerant compressed when the switching means is in the blocked state is small, and the effect of reducing the start shock is high.

  In a preferred example, a rear housing is connected to a cylinder block forming the cylinder bore, a suction chamber is formed in the rear housing, and the valve body is provided in the rear housing.

  In a preferred example, the valve body moves in the direction of the axis of the rotating shaft and is switched between the communicating position and the blocking position, and the permanent magnet intersects the moving direction of the valve body. It is fixed on the inner wall surface of the rear housing.

  The present invention has an excellent effect that the effect of reducing the start-up shock can be enhanced.

Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 1, a front housing 13 is connected to one cylinder block 11 of a pair of connected cylinder blocks 11, 12, and a rear housing 14 is connected to the other cylinder block 12. The cylinder blocks 11, 12, the front housing 13 and the rear housing 14 constitute an entire housing of the fixed displacement piston compressor 10. A discharge chamber 131 as a discharge pressure region in the compressor is formed in the front housing 13, and a discharge chamber 141 as a discharge pressure region in the compressor and a suction chamber 142 as a suction pressure region in the compressor are formed in the rear housing 14. Is formed. The inside of the compressor means the inside of the entire housing of the fixed displacement type piston compressor 10, and the outside of the compressor means the outside of the entire housing of the fixed capacity type piston type compressor 10.

  A valve plate 15, a valve forming plate 16 and a retainer forming plate 17 are interposed between the cylinder block 11 and the front housing 13. A valve plate 18, a valve forming plate 19, and a retainer forming plate 20 are interposed between the cylinder block 12 and the rear housing 14. Discharge ports 151 and 181 are formed on the valve plates 15 and 18, and discharge valves 161 and 191 are formed on the valve forming plates 16 and 19. The discharge valves 161 and 191 open and close the discharge ports 151 and 181. Retainers 171 and 201 are formed on the retainer forming plates 17 and 20. The retainers 171 and 201 regulate the opening degree of the discharge valves 161 and 191.

  A rotating shaft 21 is rotatably supported on the cylinder blocks 11 and 12. Shaft holes 111 and 121 are provided through the cylinder blocks 11 and 12, and a rotating shaft 21 is passed through the shaft holes 111 and 121. The outer peripheral surface of the rotating shaft 21 is in contact with the inner peripheral surfaces of the shaft holes 111 and 121, and the rotating shaft 21 is directly supported by the cylinder blocks 11 and 12 through the inner peripheral surfaces of the shaft holes 111 and 121. . The outer peripheral surface portion of the rotating shaft 21 in contact with the shaft hole 111 is a seal peripheral surface 211, and the outer peripheral surface portion of the rotating shaft 21 in contact with the shaft hole 121 is a seal peripheral surface 212.

  A swash plate 23 as a cam body is fixed to the rotating shaft 21. The swash plate 23 is accommodated in a swash plate chamber 24 between the cylinder blocks 11 and 12. A lip seal type shaft seal member 22 is interposed between the front housing 13 and the rotating shaft 21. The shaft seal member 22 prevents gas leakage from between the front housing 13 and the rotating shaft 21. A protruding end portion of the rotating shaft 21 that protrudes outward from the front housing 13 is connected to a vehicle engine 26 that is an external drive source via an electromagnetic clutch 25. The rotating shaft 21 obtains a rotational driving force from the vehicle engine 26 via the electromagnetic clutch 25.

  As shown in FIG. 2A, the cylinder block 11 is formed with a plurality of cylinder bores 27 arranged around the rotation shaft 21. As shown in FIG. 2B, the cylinder block 12 is formed with a plurality of cylinder bores 28 arranged around the rotation shaft 21. A double-headed piston 29 is accommodated in the cylinder bores 27 and 28 that form a pair in the front and rear (the front housing 13 side is the front side and the rear housing 14 is the rear side).

  As shown in FIG. 1, the rotational movement of the swash plate 23 that rotates integrally with the rotary shaft 21 is transmitted to the double-headed piston 29 via the shoe 30, and the double-headed piston 29 reciprocates back and forth in the cylinder bores 27 and 28. To do. The double-headed piston 29 partitions compression chambers 271 and 281 in the cylinder bores 27 and 28.

  An in-axis passage 31 is formed in the rotating shaft 21 along the rotating axis 210 of the rotating shaft 21. An inlet 311 of the in-shaft passage 31 is in the end surface 213 of the rotating shaft 21 in the cylinder block 12 and opens to the suction chamber 142 in the rear housing 14. An outlet 312 of the in-shaft passage 31 is formed on the rotating shaft 21 in the shaft hole 111 so as to open to the seal peripheral surface 211 of the rotating shaft 21. An outlet 313 of the in-shaft passage 31 is formed in the rotating shaft 21 in the shaft hole 121 so as to open to the seal peripheral surface 212 of the rotating shaft 21.

  As shown in FIG. 2A, a communication path 32 is formed in the cylinder block 11 so as to communicate with the cylinder bore 27 and the shaft hole 111. As shown in FIG. 2B, a communication passage 33 is formed in the cylinder block 12 so as to communicate with the cylinder bore 28 and the shaft hole 121. As the rotary shaft 21 rotates, the outlets 312 and 313 of the in-shaft passage 31 communicate with the communication passages 32 and 33 intermittently.

  When the double-headed piston 29 is in the intake stroke state on the cylinder bore 27 side (stroke in which the double-headed piston 29 moves from the left side to the right side in FIG. 1), the outlet 312 and the communication path 32 communicate with each other. When the double-headed piston 29 is in the suction stroke state on the cylinder bore 27 side, the refrigerant in the in-shaft passage 31 of the rotating shaft 21 is sucked into the compression chamber 271 of the cylinder bore 27 via the outlet 312 and the communication passage 32.

  When the double-headed piston 29 is in the discharge stroke state on the cylinder bore 27 side (stroke in which the double-headed piston 29 moves from the right side to the left side in FIG. 1), the communication between the outlet 312 and the communication path 32 is blocked. When the double-headed piston 29 is in the discharge stroke state on the cylinder bore 27 side, the refrigerant in the compression chamber 271 pushes the discharge valve 161 away from the discharge port 151 and is discharged into the discharge chamber 131. The refrigerant discharged into the discharge chamber 131 flows out to the external refrigerant circuit 34 through the passage 341.

  When the double-headed piston 29 is in the intake stroke state on the cylinder bore 28 side (stroke in which the double-headed piston 29 moves from the right side to the left side in FIG. 1), the outlet 313 and the communication path 33 communicate with each other. When the double-headed piston 29 is in the suction stroke state on the cylinder bore 28 side, the refrigerant in the in-shaft passage 31 of the rotating shaft 21 is sucked into the compression chamber 281 of the cylinder bore 28 via the outlet 313 and the communication passage 33.

  When the double-headed piston 29 is in a discharge stroke state on the cylinder bore 28 side (stroke in which the double-headed piston 29 moves from the left side to the right side in FIG. 1), the communication between the outlet 313 and the communication path 33 is blocked. When the double-headed piston 29 is in the discharge stroke state on the cylinder bore 28 side, the refrigerant in the compression chamber 281 pushes the discharge valve 191 away from the discharge port 181 and is discharged into the discharge chamber 141. The refrigerant discharged into the discharge chamber 141 flows out to the external refrigerant circuit 34 through the passage 342.

  A heat exchanger 37 for removing heat from the refrigerant, an expansion valve 38, and a heat exchanger 39 for transferring ambient heat to the refrigerant are interposed on the external refrigerant circuit 34. The expansion valve 38 controls the flow rate of the refrigerant according to the change in the gas temperature on the outlet side of the heat exchanger 39. The refrigerant that has flowed into the external refrigerant circuit 34 returns to the suction chamber 142.

  A portion of the seal peripheral surface 211 of the rotary shaft 21 becomes a first rotary valve 35 integrally formed with the rotary shaft 21, and a portion of the seal peripheral surface 212 of the rotary shaft 21 is a second rotary integrally formed with the rotary shaft 21. It becomes the valve 36. That is, the rotating shaft 21 is a rotary valve. The rotation axis 210 is the rotation axis of the rotary valve, and the end surface 213 of the rotation shaft 21 (that is, the end surface of the rotary valve) intersects the rotation axis 210 of the rotary valve. The in-shaft passage 31 and the outlets 312 and 313 constitute an introduction passage for the rotary valve, the shaft hole 111 is a valve housing chamber for housing the first rotary valve 35, and the shaft hole 121 is for the second rotary valve 36. It is a valve storage chamber for storing.

  As shown in FIGS. 3 and 4, the pedestal 40 is integrally formed on the end wall of the rear housing 14 that forms the suction chamber 142, and the cylinder 41 is integrally formed on the inner wall surface 401 of the pedestal 40. The rotation axis 210 of the rotation shaft 21 intersects the inner wall surface 401 perpendicularly.

  A spool-shaped valve element 42 made of a magnetic material is slidably fitted in the cylinder 411 of the cylinder 41. The valve body 42 includes a disk-shaped piston portion 43 and a cylindrical portion 44, and the cylindrical portion 44 has an introduction port 441 that opens to the outer peripheral surface of the cylindrical portion 44 and communicates with the cylinder interior 442 of the cylindrical portion 44. It is formed as follows. The cylinder interior 442 is an internal passage of the valve body 42. The piston part 43 partitions the pressure chamber 412 in the cylinder 411 of the cylinder 41. The pressure chamber 412 communicates with the suction chamber 142 through a communication port 413 formed in the cylinder 41.

  A cylindrical guide tube 45 is integrally formed on the end surface of the cylinder block 12 on the rear housing 14 side so as to face the cylinder 41. A cylinder 451 of the guide cylinder 45 communicates with an inlet 311 of the in-axis passage 31 (introduction passage). The distal end of the guide cylinder 45 and the distal end of the cylinder 41 are separated from each other, and the cylindrical portion 44 of the valve body 42 is slidably fitted to the guide cylinder 45. A circlip 46 is attached to the inner peripheral surface of the guide tube 45, and a return spring 47 is interposed between the circlip 46 and the piston portion 43. The return spring 47 biases the valve body 42 so as to approach the pedestal 40. As the valve body 42 approaches the pedestal 40, the volume of the pressure chamber 412 decreases.

  A permanent magnet 48 is fixed to the inner wall surface 401 of the base 40 in the cylinder 411 of the cylinder 41. The permanent magnet 48 protrudes from the inner wall surface 401 of the cylinder 411, and the piston portion 43 of the valve body 42 can come into surface contact with the permanent magnet 48.

  In the state shown in FIG. 4, the entire introduction port 441 is in a position where it is exposed in the suction chamber 142, and the in-shaft passage 31 passes through the inside 451 of the guide tube 45, the inside 442 of the cylinder portion 44 and the introduction port 441. And communicated with the suction chamber 142. In this state, the valve body 42 is separated from the permanent magnet 48, and FIG. 4 shows a state in which the valve body 42 is in a position where the in-shaft passage 31 and the suction chamber 142 are communicated. In the state shown in FIG. 3, the entire introduction port 441 is in a position where it enters the cylinder 411, and communication between the in-shaft passage 31 and the suction chamber 142 is blocked. In this state, the valve body 42 is in surface contact with the permanent magnet 48, and FIG. 3 shows a state in which the valve body 42 is in a position where the shaft passage 31 and the suction chamber 142 are blocked.

  As shown in FIG. 1, the electromagnetic clutch 25 is subjected to excitation / demagnetization control by the control computer C. An air conditioner operation switch 49, a room temperature setting device 50 and a room temperature detector 51 are signal-connected to the control computer C. When the air conditioner operation switch 49 is in the ON state, the control computer C uses the electromagnetic clutch 25 based on the temperature difference between the target room temperature set by the room temperature setter 50 and the detected room temperature detected by the room temperature detector 51. Controls current supply (excitation demagnetization) to.

  When the detected temperature is lower than the target temperature, or when the detected temperature is higher than the target temperature and the temperature difference between the detected temperature and the target temperature is less than the tolerance, the control computer C supplies current to the electromagnetic clutch 25. To stop. At this time, the electromagnetic clutch 25 is disengaged and the rotational driving force of the vehicle engine 26 is not transmitted to the rotating shaft 21. When the detected temperature is higher than the target temperature and the temperature difference between the detected temperature and the target temperature exceeds the allowable difference, the control computer C supplies current to the electromagnetic clutch 25. At this time, the electromagnetic clutch 25 is in a connected state, and the rotational driving force of the vehicle engine 26 is transmitted to the rotating shaft 21.

  It is assumed that the fixed displacement piston compressor 10 is in an operation stop state (a state where the electromagnetic clutch 25 is disconnected). In this state, the pressure in the compressor is balanced, and the valve body 42 is in the position to be blocked as shown in FIG. 3 by the spring force of the return spring 47. When the operation of the fixed displacement piston compressor 10 is started, the refrigerant in the shaft passage 31 and the refrigerant in the cylinders 451 and 442 are sucked into the compression chamber 271 (see FIG. 1) and the compression chamber 281. Therefore, the pressure in the in-shaft passage 31 and the in-cylinders 451 and 442 is reduced by this suction action. That is, the pressure in the in-shaft passage 31 and the cylinders 451 and 442 is lower than the pressure in the suction chamber 142. The pressure in the suction chamber 142 has spread to the pressure chamber 412, and the pressure in the pressure chamber 412 corresponds to the pressure in the suction chamber 142. The pressure in the pressure chamber 412 is opposed to the pressure in the cylinders 451 and 442 and the spring force of the return spring 47 via the valve body 42.

  The sum of the spring force of the return spring 47 and the magnetic force of the permanent magnet 48 is the difference produced between the pressure in the pressure chamber 412 and the pressure in the cylinders 451 and 442 when the fixed displacement piston compressor 10 is operated. It is set to lose pressure. Therefore, the differential pressure generated between the pressure in the pressure chamber 412 and the pressures in the cylinders 451 and 442 when the operation of the fixed displacement piston compressor 10 is started is determined by the spring force of the return spring 47 and the valve body. It overcomes the sum of the attractive force by the magnetic force when 42 and the permanent magnet 48 are in contact. As a result, the valve body 42 moves from the blocking position shown in FIG. 3 to the communicating position shown in FIG. When the valve body 42 is in a communicating position, the refrigerant in the suction chamber 142 passes to the compression chambers 271 and 281 via the introduction port 441, the cylinder interior 442, the cylinder interior 451, the shaft passage 31, and the communication passages 32 and 33. Inflow.

  When the operation of the fixed displacement piston compressor 10 is stopped, the refrigerant in the in-shaft passage 31 and the refrigerant in the cylinders 451 and 442 are not sucked into the compression chamber 271 (see FIG. 1) and the compression chamber 281. The pressures in the in-shaft passage 31 and the cylinders 451 and 442 increase. Therefore, the pressure in the in-shaft passage 31 and the cylinders 451 and 442 and the pressure in the pressure chamber 412 are balanced, and the valve element 42 is moved from the position shown in FIG. Move to the blocking position shown in.

  The valve body 42 has a suction chamber 142 (suction pressure) in the compressor according to the pressure level in the introduction passage (in-shaft passage 31) corresponding to the operation state and the operation stop state of the fixed displacement piston compressor 10. The area) and a position where the outlets 312 and 313 of the introduction passage are communicated with each other and a position where they are blocked are arranged. The valve body 42, the return spring 47, and the permanent magnet 48 include switching means 52 that can be switched between a state in which the suction chamber 142 (suction pressure region) in the compressor communicates with the outlets 312 and 313 of the introduction passage and a state in which the suction passage 142 is disconnected. Constitute.

  In the state of FIG. 3, the switching means 52 is in a state in which the outlet 312 (see FIG. 1) and outlet 313 of the introduction passage and the suction chamber 142 are shut off. In the state of FIG. The outlet 312 (see FIG. 1) and the outlet 313 are in communication with the suction chamber 142.

  A waveform E1 in the graph of FIG. 5A is an example showing a torque change in the fixed displacement piston compressor 10 when the operation of the fixed displacement piston compressor 10 is started, and FIG. A line D <b> 1 in the graph is an example showing a change in the position of the valve element 42. The horizontal axis in the graph of FIG. 5A represents time, and the vertical axis represents torque. Time To represents the time when the electromagnetic clutch 25 is switched from the demagnetized state to the excited state. The time T1 represents the time when the introduction port 441 starts to be exposed to the suction chamber 142, that is, the time when the communication between the suction chamber 142 and the cylinder 442 starts. The horizontal axis in the graph of FIG. 5B represents time, and the vertical axis represents the position of the valve element 42. A position L1 represents a blocking position (a position of the valve body 42 shown in FIG. 3), and a position L2 represents a communicating position (a position of the valve body 42 shown in FIG. 4). The difference (T1-To) represents the elapsed time from the time To when the electromagnetic clutch 25 is switched from the demagnetized state to the excited state until the introduction port 441 starts to communicate with the suction chamber 142.

  A waveform E2 in the graph of FIG. 5C is an example showing a torque change in the fixed displacement piston compressor when the operation of the fixed displacement piston compressor without the permanent magnet 48 is started. A line D2 in the graph of FIG. 5D is an example showing a change in the position of the valve element 42. In the graph of FIG. 5C, the horizontal axis represents time, and the vertical axis represents torque. Time To represents the time when the electromagnetic clutch 25 is switched from the demagnetized state to the excited state. The time T2 represents the time when the introduction port 441 starts to be exposed to the suction chamber 142, that is, the time when the communication between the suction chamber 142 and the cylinder 442 starts. The horizontal axis in the graph of FIG. 5D represents time, and the vertical axis represents the position of the valve element 42. The difference (T2−To) represents the elapsed time from the time To when the electromagnetic clutch 25 is switched from the demagnetized state to the excited state until the introduction port 441 starts to communicate with the suction chamber 142.

In the first embodiment, the following effects can be obtained.
(1) As is clear from the graphs of FIGS. 5A and 5C, the elapsed time (T1-To) is longer than the elapsed time (T2-To). If the elapsed time (T1-To) is long, rapid torque fluctuation in the fixed displacement piston compressor 10 in a short time is alleviated.

  The difference between the elapsed time (T1-To) and the elapsed time (T2-To) is due to the difference in the presence or absence of the permanent magnet 48, and is at a position where the fixed displacement piston compressor 10 is shut off when the operation is started. A certain valve body 42 is delayed by the magnetic force of the permanent magnet 48 from starting to move from the blocking position to the communicating position. Therefore, the elapsed time (T1-To) is longer than the elapsed time (T2-To). As a result, when the operation of the fixed displacement piston compressor 10 is started, the starting shock is alleviated.

  In addition, the amount of refrigerant that is compressed is small while the communication between the suction chamber 142 and the inlet 441 in the fixed displacement piston compressor 10 is blocked (that is, the valve body 42 is in the blocking position). The effect of suppressing torque fluctuation, that is, the effect of reducing the start shock is high.

  (2) When the valve body 42 is biased from the position where it communicates with the magnetic force of the permanent magnet 48 to the position where the valve element 42 is blocked, in addition to the spring force of the return spring 47, The permanent magnet 48 acting on the valve body 42 has the maximum magnetic force. Therefore, the spring force of the return spring 47 for retaining the valve element 42 at the position where the valve element 42 is blocked can be reduced as compared with the case where the permanent magnet 48 is not provided.

  When the communication between the suction chamber 142 and the introduction port 441 is started, the pressure in the introduction passage varies greatly, and the valve element 42 is easily hunted. When the valve element 42 is separated from the position where the valve element 42 is blocked (the position where the valve element 42 is attracted to the permanent magnet 48), the magnetic force of the permanent magnet 48 that acts on the valve element 42 so as to attract the valve element 42 toward the position where the valve element 42 is blocked decreases rapidly. Therefore, after the valve body 42 is separated from the permanent magnet 48, the moving speed of the valve body 42 is larger than that when the permanent magnet 48 is not provided. Therefore, it is possible to suppress the hunting of the valve element 42 even if the fluctuation of the pressure state in the introduction passage is large.

  (3) When the operation of the fixed displacement piston compressor 10 is stopped, the valve body 42 returns to the shut-off position by the spring force of the return spring 47. The use of the return spring 47 is a simple configuration for returning the valve body 42 to the position where it is shut off.

  (4) The valve body 42 moves in the direction of the rotation axis 210 of the rotation shaft 21. An inner wall surface 401 of the rear housing 14 that intersects the moving direction of the valve body 42 (the direction of the rotation axis 210) is suitable as a location where the permanent magnet 48 is attached.

  (5) When the valve body 42 is in the blocking position, the valve body 42 and the permanent magnet 48 are in contact with each other. The configuration in which the valve body 42 and the permanent magnet 48 are brought into contact with each other is suitable for increasing the acting force of the permanent magnet 48 that keeps the valve body 42 in a position where the valve body 42 is blocked.

  (6) The valve element 42 in the blocking position is retained in the blocking position in a state where it is in surface contact with the permanent magnet 48. The configuration in which the valve body 42 and the permanent magnet 48 are in surface contact is suitable for increasing the acting force of the permanent magnet 48 that keeps the valve body 42 in a position where the valve body 42 is blocked.

  (7) When the valve body 42 is in the position where the valve body 42 is blocked, the introduction port 441 which is the inlet of the cylinder body 442 of the valve body 42 enters the cylinder 411 and is shielded, and when the valve body 42 is in a position where it communicates, It is outside the cylinder 411 and exposed in the suction chamber 142. The configuration in which the introduction port 441 enters and exits the cylinder 411 is suitable for increasing the introduction port 441 and securing a sufficient cross-sectional area of the introduction passage.

Next, a second embodiment shown in FIGS. 6A and 6B will be described. The same reference numerals are used for the same components as those in the first embodiment.
A communication chamber 53 and a valve hole 541 are formed in the rear housing 14, and a plate-shaped opening / closing plate 55 made of a magnetic material is accommodated in the communication chamber 53 so that the valve hole 541 can be opened and closed. The valve hole 541 extends through the partition wall 54 that separates the communication chamber 53 and the suction chamber 142. An inlet 311 of the in-shaft passage 31 is in the end surface 213 of the rotating shaft 21 in the cylinder block 12 and opens to the communication chamber 53 in the rear housing 14.

  A piston 56 is fitted in the cylinder 411, and a transmission rod 57 is integrally formed with the piston 56. An opening / closing plate 55 is secured to the tip of the transmission rod 57. A ring-shaped permanent magnet 58 is fitted and fixed to the valve hole 541. A flat valve seat surface 581 is formed on the surface of the permanent magnet 58 on the communication chamber 53 side, and the opening / closing plate 55 contacts and separates from the valve seat surface 581. The sealing surface 551 of the opening / closing plate 55 that is in contact with the valve seat surface 581 is formed as a flat surface. That is, when the opening / closing plate 55 closes the valve hole 541, the seal surface 551 of the opening / closing plate 55 is in surface contact with the valve seat surface 581. The piston 56, the transmission rod 57, and the opening / closing plate 55 constitute a valve body 59 that opens and closes the valve hole 541, and the valve body 59 partitions the pressure chamber 412 in the cylinder 411.

  A return spring 60 is interposed between the piston 56 and the partition wall 54. The return spring 60 biases the piston 56 in a direction to push it into the cylinder 411. 6B, the valve body 59 is in a position where the valve hole 541 is opened and the communication chamber 53 and the suction chamber 142 are communicated. In FIG. 6A, the valve body 59 closes the valve hole 541 and the communication chamber 53 is connected. And the suction chamber 142 are disconnected from each other. The return spring 60 biases the valve body 59 from the communicating position toward the blocking position.

  A plurality of stoppers 552 protrude from the back surface of the opening / closing plate 55 facing the end surface 213 of the rotating shaft 21. The stopper 552 can be brought into contact with and separated from the tip of the cylindrical portion 123 protruding from the end surface 122 of the cylinder block 12. In the state where the valve body 59 is disposed at the communicating position shown in FIG. 6B, the stopper 552 is in contact with the tip of the cylindrical portion 123, and the valve body 59 is blocked at the position shown in FIG. 6A. The stopper 552 is separated from the tip of the cylindrical portion 123 in the state of being disposed at the position.

  When the fixed displacement piston compressor 10 is in the operation stop state, the valve element 59 is arranged at the position shown in FIG. 5A by the spring force of the return spring 60, and the refrigerant in the suction chamber 142 is connected to the communication chamber. Inflow to 53 is impossible. When the operation of the fixed displacement piston compressor 10 is started, the refrigerant in the shaft passage 31 and the refrigerant in the communication chamber 53 are sucked into the compression chamber 271 (see FIG. 1) and the compression chamber 281. By this suction action, the pressure in the in-shaft passage 31 and the communication chamber 53 is lowered. That is, the pressure in the shaft passage 31 and the communication chamber 53 is lower than the pressure in the suction chamber 142. Therefore, the valve body 59 is disposed at a communicating position shown in FIG. 6B, and the refrigerant in the suction chamber 142 passes through the valve hole 541, the communication chamber 53, and the in-shaft passage 31, and the compression chamber 271 (see FIG. 1). ) And the compression chamber 281.

  The valve body 59, the return spring 60, and the permanent magnet 58 are switched between a state in which the suction chamber 142 (suction pressure region) in the compressor communicates with the outlet 312 (see FIG. 1) and the outlet 313 of the introduction passage and a state in which the suction chamber 142 is shut off. The switching means 52A is configured.

  When the valve body 59 is in the blocking position, the magnetic opening / closing plate 55 is attracted to the permanent magnet 58. Therefore, the effect of mitigating the starting shock at the start of operation of the fixed displacement piston compressor 10 is high. Further, since the volume of the communication chamber 53 that accommodates the plate-shaped opening / closing plate 55 can be reduced, the effect of reducing the start shock is high as in the case of the first embodiment.

Next, a third embodiment shown in FIGS. 7A and 7B will be described. The same reference numerals are used for the same components as those in the first embodiment.
A piston 61 is slidably fitted into the cylinder 41, and the piston 61 defines a pressure chamber 412 in the cylinder 411. The piston 61 is provided so as not to contact the permanent magnet 48 fixed on the inner wall surface 401 of the base 40.

  A transmission rod 62 is connected to the piston 61. The transmission rod 62 enters the in-axis passage 31A. The in-shaft passage 31A includes a small-diameter passage 314 and a large-diameter passage 315 having a larger diameter than the small-diameter passage 314. A disc 63 is fixed to the tip of the transmission rod 62 in the small diameter passage 314, and a cylindrical circumferential surface 64 is fixed to the transmission rod 62 in the large diameter passage 315.

  The disc 63 is fitted in the small diameter passage 314 so as to be slidable in the direction of the rotation axis 210 of the rotary shaft 21, and the cylindrical circumferential surface body 64 is slidable in the direction of the rotary axis 210 of the rotary shaft 21, and The outlet 313 is fitted in the large-diameter passage 315 so that it can be opened and closed. In the cylinder of the cylindrical circumferential surface body 64, an in-axis passage 31A between the disc 63 and the circumferential surface body 64, and an in-axis passage 31A between the inlet 311 of the in-axis passage 31A and the circumferential surface body 64 are provided. And communicate with.

  As shown in FIG. 7B, when the circumferential surface body 64 is in a position to close the outlet 313, the disk 63 is upstream of the outlet 312 in the in-shaft passage 31A, and the refrigerant in the in-shaft passage 31A. Cannot flow into the compression chamber 271 through the outlet 312. As shown in FIG. 7A, when the circumferential surface body 64 is in a position to open the outlet 313, the disc 63 is located downstream of the outlet 312 in the in-shaft passage 31A, and the refrigerant in the in-shaft passage 31A. Can flow into the compression chamber 271 through the outlet 312.

  A return spring 65 is interposed between the step 316 between the small diameter passage 314 and the large diameter passage 315 and the circumferential surface body 64. The return spring 65 urges the disc 63, the circumferential surface body 64, the transmission rod 62, and the piston 61 as a whole toward the pressure chamber 412 so as to push the piston 61 into the cylinder 411.

  When the fixed displacement piston compressor 10 is in the operation stop state, the disc 63 and the circumferential surface body 64 are held at the blocking position shown in FIG. 7B by the spring force of the return spring 65. In this state, the piston 61 is slightly separated from the permanent magnet 48.

  When the operation of the fixed displacement piston compressor 10 is started, the refrigerant in the space 317 (a part of the shaft passage 31A) between the disc 63 and the end of the shaft passage 31A is sucked into the compression chamber 271. As a result, the pressure in the space 317 decreases. Therefore, the disc 63 and the circumferential surface body 64 are arranged from the blocking position shown in FIG. 7B against the spring force of the return spring 65 to the communicating position shown in FIG. When the operation of the fixed displacement piston compressor 10 is stopped, the disk 63 and the circumferential surface body 64 are returned to the blocking position shown in FIG. 7B by the spring force of the return spring 65. The disc 63, the circumferential surface body 64, the transmission rod 62, and the piston 61 constitute a valve body that partitions the pressure chamber 412 in the cylinder 411.

  The valve body is provided in the compressor according to the pressure in the space 317 [part of the introduction passage (in-shaft passage 31A)] corresponding to the operation state and the operation stop state of the fixed displacement piston compressor 10. The suction chamber 142 (suction pressure region) and the outlets 312 and 313 of the introduction passage are switched between a position where the suction chamber 142 is communicated with a position where the suction passage 142 is blocked. The valve body, the return spring 65, and the permanent magnet 48 constitute switching means 52B that can be switched between a state in which the suction chamber 142 (suction pressure region) in the compressor communicates with the outlets 312 and 313 of the introduction passage and a state in which it is shut off. To do.

  In the third embodiment, the same effect as in the first embodiment can be obtained. Further, in the third embodiment, the refrigerant that can flow into the compression chambers 271 and 281 when the disk 63 and the circumferential surface body 64 are in the blocking position is in the space 317, the outlets 312 and 313, and the communication path 32. , 33 is only the refrigerant in the first and second embodiments. Therefore, the effect of reducing the start-up shock is higher than in the first and second embodiments.

Next, a fourth embodiment shown in FIGS. 8A and 8B will be described. The same reference numerals are used for the same components as those in the first embodiment.
A permanent magnet 66 is fixed to the piston portion 43 of the valve body 42, and a joining plate 67 made of a magnetic material is fixed to the base 40.

  When the fixed displacement piston compressor 10 is in the operation stop state, the valve element 42 is held at the blocking position shown in FIG. 8A by the spring force of the return spring 47. In this state, the permanent magnet 66 is attracted to the bonding plate 67 by magnetic force.

  When the operation of the fixed displacement type piston compressor 10 is started, the valve body 42 is cut off as shown in FIG. 8A against the spring force of the return spring 47 and the attractive force of the permanent magnet 66. To the communicating position shown in FIG. The disc 63, the circumferential surface body 64, the transmission rod 62, and the valve body 42 constitute a valve body that partitions the pressure chamber 412 in the cylinder 411. The valve body 42, the return spring 47, the permanent magnet 66, and the joining plate 67 are switched so as to switch between a state in which the suction chamber 142 (suction pressure region) in the compressor communicates with the outlets 312 and 313 of the introduction passage. The means 52C is configured.

In the fourth embodiment, the same effects as in the third embodiment can be obtained.
Next, a fifth embodiment of FIG. 9 will be described. The same reference numerals are used for the same components as those in the first embodiment.

  The entire housing of the fixed displacement piston compressor 10A is composed of a cylinder block 12, a front housing 13, and a rear housing 14. A swash plate 23 is provided in a swash plate chamber 24 between the cylinder block 12 and the front housing 13. Contained. The single-head piston 68 linked to the swash plate 23 reciprocates in the cylinder bore 28 as the swash plate 23 rotates. The rotary shaft 21 is provided with a rotary valve 36 corresponding to the cylinder block 12, and the rear housing 14 is provided with a valve body 42 and a permanent magnet 48.

In the fifth embodiment, the same effect as in the first embodiment can be obtained.
In the present invention, the following embodiments are also possible.
The first rotary valve 35 and the second rotary valve 36 may be formed separately from the rotary shaft 21.

In the first embodiment, a ring-shaped permanent magnet may be fitted to the inner peripheral surface of the cylinder 41.
In the first embodiment, only the piston portion 43 of the valve body 42 may be formed of a magnetic material.

The technical idea that can be grasped from the embodiment described above will be described below.
[1] The introduction passage has an inlet on an end surface of the rotary valve and an outlet on a peripheral surface of the rotary valve, and the introduction passage has a direction of a rotation axis of the rotation shaft inside the rotation shaft. And an outlet of the introduction passage passes through a peripheral surface of the rotating shaft and communicates with the passage in the shaft, and the valve body is connected to the introduction passage from the inlet of the introduction passage. The valve body is fitted in the shaft passage so as to be slidable in the direction of the rotation axis, and the valve body is moved in the direction of the rotation axis in the shaft passage to shut off the communicating position. The fixed capacity according to any one of claims 1 to 6, wherein the shut-off position is a position where the valve body blocks the outlet of the introduction passage from the in-shaft passage. Type refrigerant compressor .

The side sectional view of the whole compressor which shows a 1st embodiment. (A) is the sectional view on the AA line of FIG. (B) is the BB sectional drawing of FIG. FIG. FIG. (A) is a graph which shows the torque change of a fixed capacity type piston type compressor provided with a permanent magnet. (B) is a graph which shows the position change of the valve body in the fixed capacity type piston type compressor provided with the permanent magnet. (C) is a graph which shows the torque change of the fixed capacity type piston type compressor which is not provided with the permanent magnet. (D) is a graph which shows the position change of the valve body in the fixed capacity | capacitance type piston type compressor which is not provided with the permanent magnet. (A), (b) is a partial expanded sectional side view which shows 2nd Embodiment. (A), (b) is the partial expanded sectional view which shows 3rd Embodiment. (A), (b) is a fragmentary sectional side view which shows 4th Embodiment. The sectional side view of the whole compressor which shows a 5th embodiment.

Explanation of symbols

  10, 10A ... Fixed capacity piston type compressor. 11, 12 ... Cylinder block. 111, 121 ... Shaft holes as valve accommodating chambers. 131, 141: Discharge chamber as a discharge pressure region. 14: Rear housing. 142: A suction chamber as a suction pressure region in the compressor. 21 ... Rotating shaft. 210: A rotational axis. 211, 212 ... Seal peripheral surface. 213 ... End face. 23 ... A swash plate as a cam body. 25: Electromagnetic clutch. 26: Vehicle engine as an external drive source. 27, 28 ... Cylinder bore. 271,281 ... Compression chamber. 29 ... Double-headed piston. 31, 31 </ b> A.. 311 ... Entrance. 312,313 ... Exit. 35: First rotary valve. 36: Second rotary valve. 401 ... Inner wall surface. 42, 59 ... Valve body. 47, 60, 65... Return spring. 48, 58, 66 ... permanent magnets. 52, 52B, 52C ... switching means. 68 ... One-headed piston.

Claims (7)

Pistons are accommodated in a plurality of cylinder bores arranged around the rotation shaft, and the piston is interlocked with the rotation of the rotation shaft through a cam body integrated with the rotation shaft. A rotary valve having an introduction passage for introducing a refrigerant from a suction pressure region into a compression chamber defined in the cylinder bore, wherein the rotary valve rotates integrally with the rotary shaft; In the refrigerant suction structure in the fixed displacement piston compressor connected to the external drive source via
Switching means for switching between a state in which the suction pressure region in the compressor and the outlet of the introduction passage communicate and a state in which the suction passage is shut off is provided, and the switching means is provided between the suction pressure region in the compressor and the introduction passage. A valve body that is switched between a position that communicates with the outlet and a position that shuts off the outlet, a return spring that returns the valve body from the communicating position to the shut-off position, and a magnetic force that acts on the valve body at the shut-off position. A refrigerant suction structure in a fixed displacement piston compressor comprising a permanent magnet that is attracted from the communicating position side to the blocking position side.   The refrigerant suction structure in the fixed displacement piston compressor according to claim 1, wherein the permanent magnet is fixed to a housing constituting the fixed displacement piston compressor.   The refrigerant suction structure in the fixed displacement piston compressor according to claim 2, wherein the valve body contacts the permanent magnet when the valve body is in the blocking position.   The refrigerant suction structure in the fixed displacement piston compressor according to claim 3, wherein the valve body and the permanent magnet are in surface contact.   5. The valve body according to claim 1, wherein when the switching unit is in the shut-off state, the valve body is disposed at a position for shutting off the inlet of the introduction passage from the suction pressure region in the compressor. A refrigerant suction structure in the fixed displacement piston compressor described in 1.   The rear housing is connected to a cylinder block forming the cylinder bore, a suction chamber is formed in the rear housing, and the valve body is provided in the rear housing. 6. A refrigerant suction structure in a fixed displacement piston compressor according to claim 5.   The valve body moves in the direction of the axis of the rotary shaft and is switched between the communicating position and the shut-off position, and the permanent magnet is an inner part of the rear housing that intersects the moving direction of the valve body. The refrigerant suction structure in the fixed displacement piston compressor according to claim 6 fixed on a wall surface.

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