JP2009203831A - Coolant control mechanism and swash plate compressor using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten a starting time, to shorten a pressure equalization time of a cooling system side, and to prevent an outflow of oil and a coolant. <P>SOLUTION: A slide valve 17 and energizing means 19, 21 are provided wherein, in positive pressure, a flow from a first passage 11 to a third passage 15 is cut off when differential pressure reaches a predetermined value or lower, and the flow is allowed when the differential pressure exceeds the predetermined value, and in counter pressure, a flow from the third passage 15 to the first passage 11 is cut off when the differential pressure reaches the predetermined value or lower, and the flow is allowed when the differential pressure exceeds the predetermined value. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a refrigerant control mechanism that controls the flow of refrigerant on the discharge side and a swash plate compressor including the refrigerant control mechanism.

  Patent Document 1 describes “control valves for air conditioners and variable capacity compressors”.

  This variable capacity compressor is a swash plate compressor, is used in a vehicle air conditioner, is driven by an engine connected without a clutch, and cannot be disconnected from the engine. Therefore, when the vehicle is accelerating or climbing, the high-pressure discharged refrigerant is returned to the inside of the compressor (crank chamber) via the flow control valve to minimize the inclination angle of the swash plate and minimize the discharge amount. Adjust to reduce engine load.

  Hereinafter, stopping an accessory (accessory) of a vehicle such as a compressor for an air conditioner is referred to as accessory off (AC off).

  In addition, this variable capacity compressor uses a check valve that shuts off the discharge port of the compressor and the cooling system of the air conditioner when the discharge pressure decreases.

Further, among the compressors, unlike the above, there are compressors that can be connected to the engine side by a clutch, and compressors that do not have a check valve.
Japanese Patent No. 3780784 (Japanese Patent Laid-Open No. 2001-153042)

  However, in a swash plate type compressor equipped with a flow rate control valve, such as a variable displacement compressor of Patent Document 1, when a check valve is used, when the AC is turned off, the discharge port is discharged by the check valve. And the cooling system (high pressure on the cooling system side) are shut off, and the pressure equalizing function of the flow control valve in the high pressure chamber provided upstream of the discharge port as the discharge pressure (Pd) decreases due to AC off As a result, the pressure (Pd) decreases to the pressure in the crank chamber (inside the compressor) (crank pressure Pc), so even if restarted thereafter, the pressure in the high pressure chamber increases from the reduced state to a predetermined value (returns). ) Takes a long time and the start-up of the compressor is slowed accordingly.

  In addition, immediately after the AC is turned off, the pressure difference (Pd−Ps) between the discharge pressure (Pd) and the suction pressure (Ps) is reduced inside the compressor, but the cooling system is disconnected from the discharge port by a check valve. As a result, the time until the system differential pressure (Pd−Ps) is equalized becomes longer. In particular, when AC off is triggered by an abnormal rise in the discharge pressure (Pd), this abnormal high pressure is applied to the constituent functions on the cooling system side such as an evaporator and a condenser for a long time. In particular, in a cooling system using CO2 (R744) as a refrigerant, various functions may be damaged and reliability may be impaired.

  In the case of a compressor that does not use a check valve, if the compressor is continuously operated with the AC off, lubricating oil or refrigerant flows out from the discharge port to the cooling system, resulting in oil shortage and oil viscosity. If the reduction occurs, there is a risk of seizing inside the compressor. On the cooling system side, for example, when the air volume of the blower is reduced, the evaporator may freeze.

  In view of this, the present invention provides a refrigerant that closes the communication flow path when the differential pressure between the high pressure chamber and the discharge port is equal to or less than a predetermined value, and opens the communication flow path when the differential pressure exceeds a predetermined value in both the forward flow and the reverse flow. By providing the control mechanism and using this refrigerant control mechanism, when AC is turned off, the check valve is used to prevent the pressure drop in the high pressure chamber and reduce the restart time. An object of the present invention is to provide a swash plate compressor that shortens the pressure equalization time and prevents oil and refrigerant from flowing out when a check valve is not used.

  The refrigerant control mechanism according to claim 1 is provided in a communication channel that connects a high-pressure chamber into which a high-pressure refrigerant flows from a compressor and a discharge port that discharges the refrigerant from the high-pressure chamber to an external system side. A refrigerant control mechanism for controlling a flow of the refrigerant, the first flow path, the second flow path, and the third flow path provided in this order from the upstream side of the positive flow refrigerant in the communication flow path. A slide valve disposed in the communication flow path so as to be slidable in both directions and capable of closing the second flow path, a pair of urging means for pressing the slide valve in opposite directions, and the first flow A first bypass passage that is provided in a passage and allows the refrigerant flow through the communication passage when the slide valve moves to the first passage; and the third passage, and the slide When the valve moves to the third flow path, the communication flow path A second bypass flow path that enables all the refrigerant flows, and the pair of urging means has a predetermined differential pressure between the high-pressure chamber pressure and the discharge port when the refrigerant flows positively in the communication flow path. The slide valve is held in the second flow path within a range equal to or lower than the value to block the flow of the refrigerant, and the slide valve is moved to the first flow rate within a range where the differential pressure between the high pressure chamber pressure and the discharge port exceeds a predetermined value. When the refrigerant flows through the second flow path to the third flow path side and allows the refrigerant to flow through the communication flow path via the second bypass flow path, When the pressure is lower than the discharge port pressure, the slide valve is moved from the second flow path to the first flow path so that the refrigerant can flow through the communication flow path via the first bypass flow path. It is characterized by doing.

  The invention described in claim 2 is the refrigerant control mechanism according to claim 1, wherein the flow path member provided with the communication flow path of the refrigerant control mechanism is separate from the compressor side member. The refrigerant control mechanism is unitized on the flow path member.

  The invention described in claim 3 is the refrigerant control mechanism according to claim 1 or 2, wherein the slide position of the slide valve is regulated to a predetermined position in the first flow path. And a second stopper that restricts the third flow path to a predetermined position.

  The invention described in claim 4 is the refrigerant control mechanism according to claim 3, wherein the second stopper of the third flow path applies the refrigerant pressure in the second flow path direction to the slide valve. The slide valve is held at a position that allows a refrigerant to flow in the second bypass flow path by providing a through-hole to be hung and giving a predetermined area to the through-hole.

  The swash plate compressor according to claim 5 comprises a swash plate that is rotated by a driving force from a directly connected engine side and that can adjust an inclination angle with respect to a rotation center axis, a piston, and a cylinder. When the piston is driven by the swinging motion of the rotation, the compression mechanism that compresses the sucked refrigerant and discharges it from the cylinder, the head of the piston is exposed, and the inclination angle of the swash plate changes according to the change in internal pressure The refrigerant control mechanism according to any one of claims 1 to 4, wherein the refrigerant is disposed such that a refrigerant discharged from the crank chamber and the cylinder flows into a high-pressure chamber of the communication flow path, and the communication flow path. And a housing member provided.

  A sixth aspect of the present invention is the swash plate compressor according to the fifth aspect, wherein the refrigerant introduction channel opens to the high pressure chamber and communicates the high pressure chamber and the crank chamber, and the refrigerant. And a flow rate control valve for controlling a flow rate of the refrigerant in the introduction flow path, adjusting a pressure of the crank chamber, and controlling an inclination angle of the swash plate.

  The invention described in claim 7 is the swash plate compressor according to claim 5 or 6, wherein the flow rate control valve senses the suction pressure (Ps) of the refrigerant, and It has a function of sensing the discharge pressure (Pd) and a function of sensing the flow rate of the refrigerant.

  The refrigerant control mechanism according to claim 1 is configured to block the communication flow path when the differential pressure between the high pressure chamber and the discharge port is equal to or less than a predetermined value in both the normal flow and the reverse flow, and communicates when the differential pressure exceeds a predetermined value. By opening the flow path, for example, when used in the swash plate compressor described below, the restart time is prevented by preventing the pressure drop in the high pressure chamber that occurs when the check valve is used due to AC off. This also shortens the pressure equalization time on the cooling system side and prevents oil and refrigerant from flowing out when a check valve is not used.

  In the refrigerant control mechanism according to the second aspect of the invention, the flow path member is separated from the compressor side member, and the refrigerant control mechanism is unitized, so that the refrigerant control mechanism is changed to an apparatus such as a compressor, for example. Since it is not necessary to build in, both the refrigerant control mechanism and the compressor can be manufactured at a low cost.

  Further, since the refrigerant control mechanism of the present invention operates by utilizing the positive pressure and the reverse pressure generated along with the flow of the refrigerant and their changes, a driving force source (actuator) is unnecessary, and the refrigerant control mechanism and the The compressor using can be configured at a lower cost.

  In the refrigerant control mechanism according to the third aspect of the present invention, the first and second stoppers for restricting the slide position of the slide valve to predetermined positions in the first flow path and the third flow path are provided. The slide valve is prevented from detaching from the moving range and functions normally.

  According to a fourth aspect of the present invention, the refrigerant control mechanism includes a through hole in the second stopper, and the refrigerant pressure in the second flow path direction is applied from the through hole to the slide valve, so that the second bypass flow path The slide valve is held in a position that allows flow.

  Accordingly, the position of the slide valve is maintained even when the flow rate of the refrigerant is reduced. As a result, the flow area from the second flow path to the third flow path is kept constant, and the pressure loss of the flow path is reduced. The

  Further, the pressure applied to the second stopper by the refrigerant pressure that pushes back the slide valve and the burden on the portion (member) where the second stopper is locked are reduced.

  When the swash plate compressor according to claim 5 is operating normally, the refrigerant flows positively through the communication channel by the discharge port pressure (PdL), and the discharge port pressure (PdL) and the high pressure chamber pressure (PdH) Pressure difference (PdH-PPdLs) exceeds a predetermined value, the slide valve moves from the second flow path to the third flow path, and the refrigerant flows through the bypass flow path.

  Further, since the swash plate compressor of the present invention does not use a check valve, immediately after the AC is turned off, the system differential pressure (PdH-PdL) is rapidly increased on the cooling system side as the discharge port pressure (PdL) decreases. Even if the pressure is equalized and, for example, the AC is turned off due to an abnormal increase in the discharge port pressure (PdL), high pressure is not applied to the constituent functions of the cooling system such as the evaporator and condenser. Thus, damage to functions and deterioration of reliability can be avoided.

  Further, when the compressor is continuously operated in the AC off state, the above-described reverse pressure is reduced and the slide valve returns to the second flow path and is closed without using a check valve. Lubricating oil and refrigerant are prevented from flowing out to the system side, and seizure inside the compressor and freezing of the evaporator due to lack of oil and a decrease in oil viscosity are prevented.

  Since the swash plate compressor described in claim 6 does not use a check valve, even if the high pressure chamber and the crank chamber communicate with each other via the flow control valve, if the AC is turned off, the high pressure chamber is cooled. A high-pressure refrigerant (system Pd) flows from the system side and is kept at a high pressure.

  Accordingly, when restarting, it is not necessary to increase (return) the pressure in the high-pressure chamber to a predetermined value, and the swash plate compressor can be started quickly.

  In the swash plate compressor described in claim 7, the flow rate control valve senses the refrigerant suction pressure (Ps), the refrigerant discharge pressure (Pd), and the refrigerant flow rate. The effect of Claim 5 or Claim 6 is acquired.

<One Embodiment>
The refrigerant control mechanism 1 and the swash plate compressor 3 using the same will be described with reference to FIGS. 1 is a longitudinal sectional view of the swash plate compressor 3, FIG. 2 is an exploded perspective view of the refrigerant control mechanism 1, FIG. 3 is a longitudinal sectional view of the communication passage 9, and FIG. FIG. 5 is a longitudinal sectional view showing the state of the refrigerant control mechanism 1 when the swash plate compressor 3 is normally operated, and FIG. 6 is an oblique view. FIG. 7 is a longitudinal sectional view showing a state of the refrigerant control mechanism 1 immediately after the plate compressor 3 is turned off, and FIG. 7 shows a state of the refrigerant control mechanism 1 when the swash plate compressor 3 is operating in an AC off state. 8 is a partially enlarged view of FIG. 5, FIG. 9 (a) is a duty ratio control of the swash plate compressor 3 (refrigerant control mechanism 1) accompanying the AC off and restart, and the rotational speed of the conventional example. Graph showing change, (b) shows changes in pressure (system pressure: PdL, suction pressure: Ps) accompanying the duty ratio control in (a). Graph showing is a graph showing the consumption torque variation of conventional swash plate type compressor 3 due to the duty ratio control of (c) is (a). Further, the left side of FIG. 1 is the front of the swash plate compressor 3.

  The refrigerant control mechanism 1 of the present embodiment includes a high-pressure chamber 5 into which high-pressure refrigerant flows from a swash plate compressor 3 (compressor) and a discharge port that discharges refrigerant from the high-pressure chamber 5 to the cooling system (external system) side. 7 is provided in the communication flow path 9 that communicates with the refrigerant 7, and controls the flow of the refrigerant.

  Further, the refrigerant control mechanism 1 of the present embodiment includes a first flow path 11, a second flow path 13, and a third flow path 15 provided in this order from the upstream side of the positive flow refrigerant in the communication flow path 9. The slide valve 17 is disposed in the communication channel 9 so as to be slidable in both directions, and can close the second channel 13, and coil springs 19 and 21 that press the slide valve 17 in opposite directions to each other (a pair of urging forces) Means) and a semi-cylindrical portion 23 (first bypass flow path) that enables refrigerant flow through the communication flow path 9 when the slide valve 17 moves to the first flow path 11. ), And a semi-cylindrical portion 25 (second bypass flow path) that enables refrigerant flow through the communication flow path 9 when the slide valve 17 moves to the third flow path 15. And.

  The coil springs 19 and 21 have a differential pressure (PdH−PdL) between the high pressure chamber pressure (PdH) and the discharge port pressure (PdL) when the refrigerant flows in the communication flow path 9 in a predetermined value or less. The slide valve 17 is held in the second flow path 13 to block the refrigerant flow, and the pressure difference (PdH−PdL) between the high pressure chamber pressure (PdH) and the discharge port pressure (PdL) exceeds a predetermined value. Then, the slide valve 17 is moved from the second flow path 13 to the third flow path 15 so that the refrigerant can flow in the communication flow path 9 via the semi-cylindrical portion 25.

  Further, when the refrigerant flows backward in the communication flow path 9, the slide valve 17 is moved from the second flow path 13 to the first flow path 11 side when the high pressure chamber pressure (PdH) is lower than the discharge port pressure (PdL). The refrigerant can flow in the communication flow path 9 through the semi-cylindrical portion 23.

  Further, in the refrigerant control mechanism 1 of the present embodiment, the slide position of the slide valve 17 is restricted to a predetermined position by the first flow path 11 and the predetermined position is restricted by the third flow path 15. The second stopper 29 of the third flow path 15 has a through hole 31 for applying the refrigerant pressure in the direction of the second flow path 13 to the slide valve 17. By giving the predetermined area A, the slide valve 17 is held at a position that allows the refrigerant to flow in the semi-cylindrical portion 25.

  The swash plate compressor 3 is composed of a swash plate 33 that can be rotated by a driving force from a directly connected engine side and can adjust an inclination angle with respect to a rotation center axis, a piston 35 and a cylinder 37. When the piston 35 is driven by swinging with rotation, the compression mechanism 39 that compresses the sucked refrigerant and discharges it from the cylinder 37 and the head 41 of the piston 35 are exposed, and the inclination angle of the swash plate 33 is changed by the change in internal pressure. The crank chamber 43 to be changed, the refrigerant control mechanism 1 arranged so that the refrigerant discharged from the cylinder 37 flows into the high-pressure chamber 5 of the communication flow path 9, and the rear housing 45 (compressor provided with the communication flow path 9) Side member).

  Further, the swash plate compressor 3 of the present embodiment opens to the high pressure chamber 5 and controls the refrigerant introduction flow path 47 that connects the high pressure chamber 5 and the crank chamber 43, and the flow rate of the refrigerant in the refrigerant introduction flow path 47. And an electromagnetic flow rate control valve 49 (flow rate control valve) that controls the inclination angle of the swash plate 33 by adjusting the pressure of the crank chamber 43, and the electromagnetic flow rate control valve 49 senses the refrigerant suction pressure (Ps). A function of sensing the refrigerant discharge pressure (Pd), and a function of sensing the refrigerant flow rate.

  Next, the structure of the swash plate type compressor 3 using the refrigerant control mechanism 1 will be described.

  The swash plate compressor 3 is used in a cooling system for a vehicle air conditioner. The high-temperature and high-pressure refrigerant gas (CO2: R744) adiabatically compressed by the swash plate compressor 3 is liquefied by a condenser (condenser). Then, it is adiabatically expanded by an expansion valve, heated and vaporized while producing cold air by an evaporator (evaporator), and returned to the swash plate compressor 3 for adiabatic compression. Note that an appropriate amount of lubricating oil is mixed in the refrigerant gas.

  As shown in FIG. 1, the swash plate compressor 3 includes a front housing 51, a cylinder block 53, a valve plate 55, and the rear housing 45. The front housing 51 and the rear housing 45 are integrated with a bolt 57. The cylinder block 53 and the valve plate 55 are fixed to the rear housing 45 with bolts 59.

  An input pulley 61 for receiving engine rotation is supported by a bearing on the front housing 51, and the input pulley 61 is splined to a drive shaft 63. The crank chamber 43 is formed between the front housing 51 and the cylinder block 53, and lubricating oil is sealed in the crank chamber 43. A plurality of cylinders 37 are formed in the cylinder block 53 at equal intervals in the circumferential direction, and each piston 35 is engaged with each cylinder 37 to constitute a plurality of compression mechanisms 39.

  The drive shaft 63 is supported by the front housing 51 and the cylinder block 53 at both front and rear ends by needle bearings 65 and 67, and a thrust bearing 69 disposed between the cylinder block 53 is a thrust force applied to the drive shaft 63 in the rearward direction. Is receiving. A lug 71 is spline-connected to the drive shaft 63, a sleeve 73 is slidably attached to the outer periphery of the drive shaft 63, and a journal 75 is swingably connected to the sleeve 73 with a pin. The swash plate 33 is screwed to the outer periphery of the journal 75, and both surfaces of the outer edge portion are slidably connected to the pistons 35 by hemispherical piston shoes 77,77. The lugs 71 and the arms 79 and 81 of the journal 75 are connected to each other via a pin 83 so as to be rotatable.

  The rotational torque from the engine input to the input pulley 61 rotates the drive shaft 63 (lug 71), and this rotation is transmitted to the journal 75 (swash plate 33) via the arms 79 and 81 and the pin 83, and the swash plate 33. While sliding with each piston shoe 77, each piston 35 is reciprocated in the axial direction with a stroke corresponding to the inclination angle to drive each compression mechanism 39, and each compression mechanism 39 has an amount corresponding to this stroke. The refrigerant is sucked, compressed and discharged.

  The sleeve 73 has a biasing force of a return spring 85 disposed between the lug 71 and a differential pressure (PdH-PdL) between the pressure of the high pressure chamber 5 (PdH) and the outlet port pressure (PdL) of each cylinder 37. As described below, the electromagnetic flow control valve 49 controls the differential pressure (PdH-PdL), thereby resisting the return spring 85 and the swash plate 33 (sleeve 73 and journal 75). Is moved in the axial direction.

  When the swash plate 33 moves to the cylinder block 53 side, the inclination angle (stroke of each piston 35) of the swash plate 33 decreases, and when the inclination angle of the swash plate 33 becomes zero (destroke), the stroke and the discharge amount are minimized. . Further, when the swash plate 33 moves to the lug 71 side, the inclination angle and stroke increase, and when the journal 75 abuts the lug 71, the inclination angle, stroke, and discharge amount become maximum.

  The rear housing 45 is formed with a refrigerant suction chamber 87 and a refrigerant discharge chamber 89 that communicate with the cylinders 37. A suction valve is disposed between the valve plate 55 and the refrigerant suction chamber 87. A discharge valve is arranged between the discharge chamber 89. The refrigerant suction chamber 87 is connected to the evaporator side via a refrigerant flow path, and the refrigerant discharge chamber 89 is connected to the condenser side via another refrigerant flow path. The high pressure chamber 5 is formed on the side of the communication flow path 9 of the refrigerant discharge chamber 89.

  The electromagnetic flow control valve 49 is disposed inside the rear housing 45, communicates with the refrigerant suction chamber 87 via flow paths 91 and 93, and communicates with the refrigerant discharge chamber 89 (high pressure chamber 5). It communicates via the refrigerant introduction flow path 47 and communicates with the crank chamber 43 via the flow path 91. Further, the electromagnetic flow control valve 49 is provided with ports (functions for detecting the refrigerant suction pressure Ps, the discharge pressure Pd, and the flow rate), respectively, for inputting the refrigerant suction pressure (Ps) and the discharge pressure (Pd). The flow rate of the refrigerant is detected based on the differential pressure (Pd−Ps). The electromagnetic flow rate control valve 49 is adjusted in opening degree by the duty ratio control of the controller, moves the refrigerant between the high pressure chamber 5 and the crank chamber 43 via the refrigerant introduction passage 47 and the passage 91, and differential pressure ( Pd−Ps) is controlled to adjust the tilt angle of the swash plate 33, and when the AC is off, the tilt angle of the swash plate 33 is made zero.

  Further, an appropriate gap is provided between the piston 35 and the cylinder 37, and a refrigerant gas containing lubricating oil is blown into the crank chamber 43 from this gap, and is agitated and mixed with the refrigerant. The hemispherical sliding part between the piston 35 and the piston shoe 77, the sliding part with the piston shoe 77 on the swash plate 33, the sliding part between the drive shaft 63 and the sleeve 73, the sleeve 73 and the journal 75 The sliding portion of the arm 79, 81 and the sliding portion of the pin 83 are lubricated and cooled. The oil mist moves from oil flow paths 95 and 97 provided at the front portion of the front housing 51 to the lip seal 99 between the drive shaft 63 and the front housing 51, and the oil mist is rotated by the rotation (centrifugal force) of the drive shaft 63. Lubricating oil is separated from the mist, and the needle bearings 65 and 67 are lubricated and cooled.

  The first and second stoppers 27 and 29 constituting the refrigerant control mechanism 1 are positioned in the first flow path 11 and the third flow path 15 by snap rings 101 and 103 attached to the rear housing 45, respectively.

  The slide valve 17 is a cylindrical member having a bottom 105, the coil spring 19 presses the slide valve 17 toward the third flow path 15 between the stopper 27 and the bottom 105, and the coil spring 21 uses the stopper 29 as a support point. The slide valve 17 is pressed toward the first flow path 11 side.

  In the swash plate compressor 3, when the vehicle stops the engine and the rotation of the swash plate compressor 3 stops, the discharge pressure (Pd) of the refrigerant discharged into the high pressure chamber 5 decreases and the suction pressure (Ps) Since the differential pressure (Pd−Ps) disappears, as shown in FIG. 4, the slide valve 17 is held in the second flow path 13 by the biasing force of the coil springs 19 and 21, and the pressure equalization of the electromagnetic flow control valve 49 is performed. The pressure (crank pressure Pc) of the high-pressure chamber 5 and the crank chamber 43 is maintained at an equal pressure by the function.

  Further, when the vehicle travels, a predetermined inclination angle is given to the swash plate 33, and a refrigerant having a discharge pressure (Pd) is discharged into the high-pressure chamber 5, and as indicated by an arrow in FIG. 5, the discharge pressure (Pd) The refrigerant flows forward, the pressure difference (PdH−PdL) between the pressure in the high-pressure chamber 5 (PdH) and the system pressure (PdL) equal to the pressure in the discharge port 7 exceeds the set value, and the slide valve 17 The refrigerant flows through the semi-cylindrical portion 25 by bending and moving from the second flow path 13 to the third flow path 15.

  Next, for example, in order to cut (reduce) the torque consumption of the engine as the vehicle accelerates, if the AC is turned off from the above state, it is necessary for the crank chamber 43 through the electromagnetic flow rate control valve 49 controlled by the duty ratio. Pressure is applied, the inclination angle of the swash plate 33 is minimized, and the pressure difference (PdH−PdL) becomes lower than the set value due to a decrease in the discharge pressure (Pd), causing a temporary counter pressure. With this reverse pressure, the coil spring 19 is bent and the slide valve 17 returns from the third flow path 15 to the first flow path 11 as shown in FIG. 6, and the refrigerant flows backward from the cooling system side via the semi-cylindrical portion 23. As a result, the pressure in the high-pressure chamber 5 rapidly becomes equal to the system pressure (PdL), and the system pressure (PdL) also decreases to prevent damage to the evaporator and the like. Further, since the pressure in the high pressure chamber 5 is maintained at the system pressure (PdL), if the swash plate compressor 3 is restarted from this state, it is not necessary to raise the pressure in the high pressure chamber 5 from zero. It can be started with.

  When the swash plate compressor 3 starts stable operation with the AC off, the differential pressure (PdH-PdL) is maintained below the set value as shown in FIG. Since it returns to the 2nd flow path 13 from a position and this is closed, the outflow of lubricating oil and a refrigerant | coolant to the cooling system side is prevented similarly to the function of a non-return valve.

FIG. 8 is a partially enlarged view of FIG. 5. F1: Reaction force of the coil spring 21 pressing the slide valve 17 to the second flow path 13 side, F2: Move the slide valve 17 to the third flow path 15 side. Force
F2 = A (area of the through hole 31 of the stopper 29) × (PdD−PdL), and when F2> F1, the slide valve 17 is held at the position of FIG.

  Further, when the refrigerant flows from the second flow path 13 to the third flow path 15 via the semi-cylindrical portion 25, a pressure loss (PdH-Pdm) occurs, and when the third flow path 15 becomes longer, the second flow path 13 is increased. Is reduced to PdL and the pressure loss is increased to (PdH + Pdm). Therefore, the force (F2) that presses the slide valve 17 toward the third flow path 15 side becomes PdD due to the addition of dynamic pressure, and the differential pressure ( PdH−PdL) is maximized.

  Here, as shown in FIG. 8, when the slide valve 17 moves to a position where it comes into contact with the stopper 29, the differential pressure (PdH-PdL) is maximized, so that F2 is also maximized, and F2> F1 and the slide valve 17 is While being held at the position of FIG. 8, the slide valve 17 is held at this position even if the flow rate of the refrigerant is reduced. As a result, the flow area from the second flow path 13 to the third flow path 15 is kept constant, and the pressure loss of the flow path is reduced.

  Further, the force represented by the product of the area A of the through hole 31 provided in the stopper 29 and the pressure (PdL) acts in a direction to push the bottom portion 105 of the slide valve 17 back to the second flow path 13 side. Accordingly, the force applied to the rear housing 45 is reduced, and the locking portion of the snap ring 103 to the rear housing 45 is protected.

  Next, the function of the refrigerant control mechanism 1 will be described with reference to the graph of FIG.

  A graph 111 in FIG. 9A shows the duty ratio control when the swash plate compressor 3 (refrigerant control mechanism 1) is AC-off and return control (restart) as shown in FIG. These show the rotation speed change accompanying this duty ratio control of the conventional swash plate type compressor using a check valve and a flow control valve.

  As indicated by the graph 111, when the AC is turned off at the arrow 113, the duty ratio signal is stopped as indicated by the arrow 115, and then when the restart is performed, the duty ratio signal is applied again as indicated by the arrow 117. . Moreover, as the graph 121 shows, the rotation speed of a prior art example rises before and after AC-off like the graph 123, and if it restarts, it will return to the rotation speed before a raise like the arrow 125. FIG.

  The graphs 131, 141, 151, and 161 in FIG. 9B show changes in the system pressure (PdL) and the suction pressure (Ps) in the swash plate compressor 3 and the conventional example with AC off and restart, respectively. Yes. As indicated by the graph 131, the system pressure (PdL) of the swash plate compressor 3 rapidly decreases as indicated by an arrow 133 as AC is turned off, and returns to the original pressure as indicated by an arrow 135 when restarted. However, in the conventional example, as indicated by the graph 141, even when AC is turned off, it takes time for the cooling system side to decrease in pressure due to the check valve cutoff function. Similarly, in the swash plate compressor 3, the suction pressure (Ps) also rapidly increases as AC is turned off and decreases to the original pressure when restarted. However, in the conventional example, as shown in the graph 161, the AC pressure is reduced. Even if it is turned off, the cooling system side is slow to rise due to the check valve blocking function, and it takes time to drop. .

  Graphs 171 and 181 in FIG. 9 (c) show changes in the consumption torque of the conventional example using the swash plate compressor 3 and the check valve accompanying AC off and restart, respectively. Like 173 and 183, the consumption torque decreases at a stretch. When restarted, in the swash plate compressor 3, the consumption torque returns to the original value as indicated by an arrow 175, but in the conventional example, it is necessary to circulate the refrigerant in the cooling system as the check valve is opened. The return of the consumption torque is delayed by the amount of work as indicated by an arrow 183.

  Next, effects of the refrigerant control mechanism 1 and the swash plate compressor 3 configured as described above will be described.

  When the refrigerant control mechanism 1 is used in the swash plate compressor 3 that does not use a check valve as described above, even if the AC is turned off, the high pressure chamber 5 is prevented from being reduced in pressure by the inflow system pressure (Pd). Therefore, at the time of restarting, it is not necessary to increase the pressure of the high pressure chamber 5 from a low pressure state to a predetermined value, and it is possible to start up as quickly as possible.

  Further, immediately after AC off, the differential pressure (Pd-Ps) is quickly equalized even on the cooling system side. Therefore, in the cooling system using CO2 (R744) as the refrigerant, such as the swash plate compressor 3, For example, even when the AC is turned off due to an abnormal increase in the discharge pressure (Pd), damage to functions such as an evaporator and a capacitor constituting the cooling system is prevented, and a decrease in reliability can be avoided.

  Further, since the lubricating oil and refrigerant are prevented from flowing out to the cooling system without using a check valve, seizure inside the swash plate compressor 3 due to oil shortage or oil viscosity reduction, Freezing is prevented.

  Further, since the refrigerant control mechanism 1 operates by using the positive pressure and the reverse pressure generated in the refrigerant flow, a driving force source (actuator) is unnecessary, and accordingly, the refrigerant control mechanism 1 and the swash plate compressor 3 are connected. Therefore, it can be configured at a low cost.

  Further, by providing the stoppers 27 and 29, the slide valve 17 is prevented from leaving the normal movement range, and the refrigerant control mechanism 1 functions normally.

  Further, by applying a refrigerant pressure to the slide valve 17 from the through hole 31 provided in the stopper 29, the slide valve 17 is held at a position that allows the refrigerant flow in the bypass passage 25, and the flow rate of the refrigerant is reduced. Even so, since the slide valve 17 is held in this position, the flow area from the second flow path 13 to the third flow path 15 is kept constant, and the pressure loss of the flow path is reduced.

  In addition, the force applied to the stopper 29 and the snap ring 103 is alleviated by the refrigerant pressure from the through hole 31 that pushes back the slide valve 17, and the engaging portion between the snap ring 103 and the rear housing 45 is protected.

  Further, the swash plate compressor 3 obtains the above effect by using the refrigerant control mechanism 1.

[Other Embodiments Included within the Scope of the Present Invention]
It should be noted that the present invention is not limited to the above-described embodiment, and various modifications can be made within the technical scope of the present invention.

  For example, the refrigerant control mechanism of the present invention can be unitized on the flow path member separate from the rear housing 45 of the swash plate compressor 3, as in the configuration of claim 2, and as a result, the refrigerant control mechanism Therefore, it is possible to manufacture both the refrigerant control mechanism and the swash plate compressor at a low cost.

3 is a longitudinal sectional view of a swash plate compressor 3. FIG. 3 is an exploded perspective view of the refrigerant control mechanism 1. FIG. 3 is a longitudinal sectional view of a communication flow path 9. FIG. It is a longitudinal cross-sectional view which shows the state of the refrigerant control mechanism 1 when an engine is stopped and rotation of the swash plate type compressor 3 is stopped. It is a longitudinal cross-sectional view which shows the state of the refrigerant | coolant control mechanism 1 when the swash plate type compressor 3 is drive | operating normally. It is a longitudinal cross-sectional view which shows the state of the refrigerant | coolant control mechanism 1 immediately after the swash plate type compressor 3 is turned off AC. It is a longitudinal cross-sectional view which shows the state of the refrigerant | coolant control mechanism 1 when the swash plate type compressor 3 is operate | moving in the state of AC off. It is the elements on larger scale of FIG. (A) is a graph showing the duty ratio control of the swash plate compressor 3 (refrigerant control mechanism 1) accompanying AC off and restart, and a graph showing the rotational speed change of the conventional example, and (b) is a duty ratio control of the above (a). The graph which shows the change of the accompanying pressure (system pressure PdL, the suction pressure Ps), (c) is a graph which shows the consumption torque change of the swash plate type compressor 3 accompanying the duty ratio control of said (a), and a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Refrigerant control mechanism 3 Swash plate type compressor 5 High pressure chamber 7 Discharge port 9 Communication flow path 11 1st flow path 13 2nd flow path 15 3rd flow path 17 Slide valve 19, 21 Coil spring (a pair of urging means)
23 Semi-cylindrical part (first bypass flow path)
25 Semi-cylindrical part (second bypass flow path)
27 First stopper 29 Second stopper 31 Through hole provided in second stopper 29 33 Swash plate 35 Piston 37 Cylinder 37
39 Compression mechanism 43 Crank chamber 45 Rear housing (compressor side member)
47 Refrigerant introduction flow path 49 Electromagnetic flow control valve (flow control valve)

Claims (7)

A communication channel (9) that connects the high-pressure chamber (5) into which high-pressure refrigerant flows from the compressor (3) and the discharge port (7) that discharges the refrigerant from the high-pressure chamber (5) to the external system side. A refrigerant control mechanism (1) for controlling the flow of the refrigerant,
In the communication channel (9), a first channel (11), a second channel (13), and a third channel (15) provided in this order from the upstream side of the positive-flowing refrigerant,
A slide valve (17) disposed in the communication channel (9) to be slidable in both directions and capable of closing the second channel (13);
A pair of biasing means (19, 21) for pressing the slide valve (17) in opposite directions;
A first flow path is provided in the first flow path (11) and enables a refrigerant flow through the communication flow path (9) when the slide valve (17) moves to the first flow path (11). A bypass channel (23);
A second flow path is provided in the third flow path (15) and enables a refrigerant flow through the communication flow path (9) when the slide valve (17) moves to the third flow path (15). A bypass channel (25),
The pair of biasing means (19, 21)
When the refrigerant flows positively in the communication channel (9),
When the pressure difference (PdH−PdL) between the high-pressure chamber pressure (PdH) and the discharge port (PdL) is not more than a predetermined value, the slide valve (17) is held in the second flow path (13) to Shut off the flow,
The slide valve (17) is moved from the second flow path (13) to the third flow path within a range in which the differential pressure (PdH-PdL) between the high pressure chamber pressure (PdH) and the discharge port (PdL) exceeds a predetermined value. (15) moved to the side, enabling the flow of the refrigerant in the communication channel (9) through the second bypass channel (25),
When the refrigerant flows backward in the communication channel (9),
When the high pressure chamber pressure (PdH) is lower than the discharge port pressure (PdL), the slide valve (17) is moved from the second flow path (13) to the first flow path (11) side, and the first A refrigerant control mechanism (1) characterized in that the refrigerant flow in the communication channel (9) is enabled via the bypass channel (23). A refrigerant control mechanism according to claim 1,
The flow path member provided with the communication flow path (9) of the refrigerant control mechanism (1) is provided separately from the member (45) on the compressor (3) side,
The refrigerant control mechanism (1), wherein the refrigerant control mechanism (1) is unitized on the flow path member. The refrigerant control mechanism according to claim 1 or 2, wherein
The slide position of the slide valve (17) is
A first stopper (27) that restricts the first flow path (11) to a predetermined position;
A refrigerant control mechanism (1) having a second stopper (29) for regulating the third flow path (15) at a predetermined position. A refrigerant control mechanism according to claim 3,
The second stopper (29) of the third flow path (15) has a through hole (31) for applying a refrigerant pressure in the direction of the second flow path (13) to the slide valve (17);
The slide valve (17) is held at a position that allows the refrigerant to flow in the second bypass flow path (25) by giving a predetermined area to the through hole (31). Refrigerant control mechanism (1). A swash plate (33) that is rotated by a driving force from a directly connected engine side and that can adjust an inclination angle with respect to a rotation center axis;
When the piston (35) is driven by a swing accompanying rotation of the swash plate (33), the sucked refrigerant is compressed and discharged from the cylinder (37). A compression mechanism (39);
A crank chamber (43) in which the head (41) of the piston (35) is exposed, and the inclination angle of the swash plate (33) changes due to a change in internal pressure;
The refrigerant control mechanism according to any one of claims 1 to 4, wherein the refrigerant discharged from the cylinder (37) is arranged so as to flow into the high-pressure chamber (5) of the communication channel (9). 1) and
A swash plate compressor (3) comprising a housing member (45) provided with the communication channel (9). A swash plate compressor according to claim 5,
A refrigerant introduction channel (47) that opens to the high pressure chamber (5) and communicates the high pressure chamber (5) and the crank chamber (43), and controls the flow rate of the refrigerant in the refrigerant introduction channel (47). And a flow rate control valve (49) for adjusting the pressure of the crank chamber (43) and controlling the inclination angle of the swash plate (33). A swash plate compressor according to claim 5 or 6,
The flow rate control valve (49) has a function of sensing the refrigerant suction pressure (Ps), a function of sensing the refrigerant discharge pressure (Pd), and a function of sensing the refrigerant flow rate. Swash plate compressor (3).

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