WO2019049569A1

WO2019049569A1 - Variable displacement compressor

Info

Publication number: WO2019049569A1
Application number: PCT/JP2018/029094
Authority: WO
Inventors: 広明岩下; 土方　康種; 匡志東山
Original assignee: 株式会社デンソー
Priority date: 2017-09-07
Filing date: 2018-08-02
Publication date: 2019-03-14
Also published as: DE112018004928T5; JP6711336B2; JP2019043506A

Abstract

This variable displacement compressor is provided with: a compression mechanism (12); a volume control mechanism (40) for controlling the volume of discharge of a refrigerant from the compression mechanism; a clutch (MGC); and a control device (100) for controlling the volume control mechanism and the clutch to switch between operating modes. The compression mechanism is provided with a volume limiting section for limiting the lower limit of the volume of discharge, to an intermediate volume which is greater than a minimum volume and smaller than a maximum volume. The control device can switch the operating mode to a variable operation mode and an intermittent operation mode. The variable operation mode is an operating mode in which the volume of discharge is changed by the volume control mechanism in a range from the lower limit volume to the maximum volume. The intermittent operation mode is an operating mode in which the state of connection is intermittently switched to a connected state and a disconnected state by the clutch while the volume of discharge is controlled to the lower limit volume by the volume control mechanism.

Description

Variable displacement compressor

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on Japanese Patent Application No. 2017-172047 filed on September 7, 2017, the contents of which are incorporated herein by reference.

The present disclosure relates to a variable displacement compressor capable of changing the discharge capacity of a refrigerant.

Conventionally, a variable displacement compressor applied to a vehicle air conditioner can change the discharge capacity of the compression mechanism by changing the pressure of the control pressure chamber formed in the housing using the discharge refrigerant. . In the variable displacement compressor, the compression efficiency indicated by the ratio of the theoretical power to the actual power tends to decrease near the minimum displacement. Accordingly, in the variable displacement compressor, the coefficient of performance (that is, the abbreviation COP (coefficient of performance)) is likely to decrease when the discharge displacement is near the minimum displacement. The discharge capacity is a geometrical volume of the working space for suction and compression of the refrigerant. For example, in a piston type compressor, the cylinder volume between the top dead center and the bottom dead center of the piston stroke is the discharge volume.

On the other hand, when the displacement control signal value input to the compressor becomes equal to or less than the predetermined value A, the displacement control signal value corresponding to the predetermined discharge displacement and the displacement control signal value corresponding to the minimum displacement are at a predetermined timing. What performs intermittent operation switched by is proposed (for example, refer to patent documents 1). Thereby, in patent document 1, it is going to suppress the driving | operation in the minimum capacity vicinity which compression efficiency falls.

JP, 2011-173491, A

By the way, the discharge displacement of the compressor may change independently of the predetermined displacement control signal value. For example, in the case of using a suction control type displacement control valve that controls the suction pressure of the refrigerant to a target pressure as a method of controlling the discharge displacement of the compressor, the air of the evaporator is When the heat load on the side increases or decreases, the displacement changes so as to maintain the suction pressure of the refrigerant.

Therefore, as in Patent Document 1, when the continuous operation in which the discharge displacement is continuously changed and the intermittent operation in which the discharge displacement is changed intermittently are switched according to the volume control signal value, the continuous operation is performed in a state where the discharge displacement is small. Or, there is a possibility that intermittent operation may be performed in a state where the discharge capacity is large. As described above, in the method of switching between the continuous operation and the intermittent operation according to the capacity control signal value as in Patent Document 1, the compression efficiency can not always be exhibited excellent, and there is room for improvement.

An object of the present disclosure is to provide a variable displacement compressor that can improve compression efficiency by avoiding operation with the minimum displacement.

The present disclosure is applied to a refrigeration cycle apparatus including an evaporator that cools air blown out to a space to be air-conditioned by the latent heat of evaporation of the refrigerant, and is a variable displacement compression capable of changing the displacement of the refrigerant within the range from the minimum capacity to the maximum capacity. It is intended for aircraft.

According to one aspect of the present disclosure, a variable displacement compressor is
A compression mechanism driven by an engine to compress and discharge the refrigerant;
A displacement control mechanism that controls the displacement of the refrigerant discharged from the compression mechanism;
A clutch that switches a state of connection between the compression mechanism and the engine between a state in which driving force of the engine is transmitted to the compression mechanism and a state in which the driving force of the engine is not transmitted to the compression mechanism;
And a controller that controls the displacement control mechanism and the clutch to switch the operation mode.

The compression mechanism is provided with a capacity limiting portion which limits the lower limit displacement of the discharge displacement to an intermediate displacement which is larger than the minimum displacement and smaller than the maximum displacement. Then, the control device can switch the operation mode to the variable operation mode and the intermittent operation mode. However, in the variable operation mode, the discharge temperature is changed in the range from the lower limit capacity to the maximum capacity by the capacity control mechanism in a state in which the connection state is controlled to the connection state by the clutch. It is an operation mode close to the target evaporator temperature. In the intermittent operation mode, the discharge temperature is made to approach the target evaporator temperature by switching the connection state between the connection state and the disconnection state intermittently by the clutch while the discharge capacity is controlled to the lower limit capacity by the capacity control mechanism. It is an operation mode.

In the variable displacement compressor of the present disclosure, since the lower limit capacity of the discharge capacity of the compression mechanism is limited by the capacity limiting unit to an intermediate capacity larger than the minimum capacity, operation of the compression mechanism with the minimum capacity with low compression efficiency It can be avoided.

Here, simply limiting the lower limit capacity of the discharge capacity of the compression mechanism to an intermediate capacity larger than the minimum capacity reduces the variable range of the discharge capacity, for example, the air cooling capacity in the evaporator becomes excessive. It is feared that it will

On the other hand, since the variable displacement compressor according to the present disclosure can switch the operation mode to the variable operation mode and the intermittent operation mode, the switching of the operation mode causes the variable range of the discharge capacity to be reduced. It is possible to avoid problems. That is, according to the variable displacement compressor of the present disclosure, it is possible to improve compression efficiency while appropriately exhibiting the cooling capacity of the evaporator.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic block diagram of the refrigerating-cycle apparatus to which the variable displacement-type compressor of 1st Embodiment was applied. It is a typical sectional view showing the internal structure of the variable displacement compressor of a 1st embodiment. It is an explanatory view for explaining the relation between discharge capacity and COP. It is a schematic diagram which shows the structure of the capacity | capacitance control mechanism of 1st Embodiment. It is a flowchart which shows the flow of the control processing which the control apparatus of 1st Embodiment performs. It is a flowchart which shows the flow of the variable driving | operation process which the control apparatus of 1st Embodiment performs. It is a schematic diagram which shows the operating state of the capacity | capacitance control mechanism in the time of largest capacity | capacitance. It is a schematic diagram which shows the operating state of the variable displacement compressor at maximum capacity. It is a schematic diagram which shows the operating state of the capacity | capacitance control mechanism in the time of a lower limit capacity | capacitance. It is a schematic diagram which shows the operating state of the variable displacement compressor at the time of a minimum capacity | capacitance. It is an explanatory view for explaining the relation between blowing temperature and a capacity control signal value. It is explanatory drawing for demonstrating the determination method of a lower limit signal value. It is a flowchart which shows the flow of the intermittent operation process which the control apparatus of 1st Embodiment performs. It is an explanatory view for explaining a decision threshold at the time of on-off change of a clutch. It is a timing chart which shows an example of change of a blow-off temperature at the time of change of operation mode, a capacity control signal value, a clutch on-off state, discharge capacity, etc. The capacity | capacitance control mechanism of 2nd Embodiment WHEREIN: It is a schematic diagram which shows the state which the air supply passage opened and the extraction passage closed. In a capacity control mechanism of a 2nd embodiment, it is a mimetic diagram showing the state where both the air supply passage and the extraction passage were opened. The capacity | capacitance control mechanism of 2nd Embodiment WHEREIN: It is a schematic diagram which shows the state which the air supply passage closed and the extraction passage opened. It is a figure which shows the motive power at the time of making the compressor operated only by variable operation mode into a comparative example, the compressor of 1st Embodiment 1st Example, and making the compressor of 2nd Embodiment 2nd Example. It is a figure showing a coefficient of performance at the time of making a compressor operated only by variable operation mode into a comparative example, making a compressor of a 1st embodiment into a 1st example, and making a compressor of a 2nd embodiment into a 2nd example. . It is a schematic diagram which shows the capacity | capacitance control mechanism of 3rd Embodiment. It is a schematic diagram which shows the capacity control mechanism of 4th Embodiment. It is a schematic diagram which shows the structure of the displacement control mechanism of 5th Embodiment. It is a flowchart which shows the flow of the variable driving | operation process which the control apparatus of 5th Embodiment performs. It is a flowchart which shows the flow of the control processing which the control apparatus of 6th Embodiment performs. It is a flowchart which shows the flow of the variable driving | operation process which the control apparatus of 6th Embodiment performs. It is an explanatory view for explaining a judgment threshold etc. which are used for switching etc. of operation mode. It is a flowchart which shows the flow of the transition driving | operation process which the control apparatus of 6th Embodiment performs. It is a flowchart which shows the flow of the intermittent operation process which the control apparatus of 6th Embodiment performs.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following embodiments, the portions that are equivalent same or a matters described in the preceding embodiments are denoted by the same reference numerals, it may be omitted from the description. Further, in the embodiment, when describing the only part of the components, with respect to other parts of the components can be applied to components described in previous embodiments. The following embodiments, as long as it does not create an obstacle to the particular combination, even if not specifically stated, it is possible to combine the respective embodiments with each other partially.

First Embodiment
The present embodiment will be described with reference to FIGS. 1 to 15. In the present embodiment, an example will be described in which a variable displacement compressor 10 of the present disclosure (hereinafter, may be simply referred to as a compressor 10) is applied to a refrigeration cycle apparatus 1 for air conditioning a vehicle interior. In the present embodiment, the vehicle interior corresponds to the air conditioning target space.

As shown in FIG. 1, the refrigeration cycle apparatus 1 is constituted by a closed circuit in which a compressor 10, a condenser 50, a gas-liquid separator 60, an expansion valve 70, an evaporator 80 and the like are connected in this order by refrigerant piping and the like. It is done.

The compressor 10 is an engine driven compressor in which a compression mechanism 12 for compressing a refrigerant is driven by an engine EG for traveling a vehicle. The compressor 10 has a clutch MGC. The clutch MGC constitutes a power transmission device PT that transmits the power of the engine EG to the compression mechanism 12 of the compressor 10 together with the belt mechanism VB. The compression mechanism 12 is rotationally driven by transmitting the driving force from the engine EG via the power transmission device PT.

The clutch MGC is in a connected state where the driving force of the engine EG is transmitted to the compression mechanism 12 (ie, in the on state) and in a disconnected state where the driving force of the engine EG is not transmitted to the compression mechanism Switching to the state). The clutch MGC couples the engine EG and the compression mechanism 12 by energization, and releases the coupled state of the engine EG and the compression mechanism 12 when the energization is shut off.

The compressor 10 is configured of an external variable displacement compressor capable of changing the discharge displacement of the refrigerant in the range from the minimum displacement to the maximum displacement by a displacement control signal value Ic from a control device 100 described later. The details of the compressor 10 will be described later.

A condenser 50 is connected to the refrigerant discharge side of the compressor 10. The condenser 50 is disposed between the engine EG and the front grille (not shown) in the engine room (not shown), and is a radiator for heat exchange between the refrigerant discharged from the compressor 10 and the outside air to dissipate the refrigerant. is there.

A gas-liquid separator 60 is connected to the refrigerant outlet side of the condenser 50. The gas-liquid separator 60 is configured to separate the gas-liquid of the refrigerant flowing out of the condenser 50 and to lead out the separated liquid-phase refrigerant.

An expansion valve 70 is connected to the liquid-phase refrigerant outlet side of the gas-liquid separator 60. The expansion valve 70 is a decompression device that decompresses and expands the liquid-phase refrigerant separated by the gas-liquid separator 60. The expansion valve 70 is a thermal expansion valve, and includes a temperature sensing unit 72 that detects the temperature of the refrigerant between the refrigerant outlet side of the evaporator 80 and the refrigerant suction side of the compressor 10. The expansion valve 70 is configured to adjust the valve opening based on the temperature and pressure of the refrigerant drawn into the compressor 10 so that the degree of superheat of the refrigerant drawn into the compressor 10 becomes a predetermined value.

An evaporator 80 is connected to the refrigerant outlet side of the expansion valve 70. The evaporator 80 is disposed in the air conditioning case 92 of the air conditioning unit 90. The evaporator 80 cools the air flowing in the air conditioning case 92, that is, the air blown into the vehicle compartment, by the latent heat of evaporation of the refrigerant decompressed and expanded by the expansion valve 70.

Here, a blower 94 is disposed in the air conditioning case 92. Outside air or inside air introduced from an inside / outside air switching box (not shown) is supplied to the evaporator 80 by the blower 94. The air supplied to the evaporator 80 passes through the evaporator 80 and then blows out into the vehicle compartment through a heater unit (not shown). Further, in the air conditioning case 92, an evaporator temperature sensor 104 is provided which detects the blowout temperature TE of air immediately after passing through the evaporator 80.

The compressor 10 is connected to the refrigerant outlet side of the evaporator 80. The refrigerant evaporated by the evaporator 80 is again sucked by the compressor 10. As described above, in the refrigeration cycle apparatus 1, the refrigerant discharged from the compressor 10 is circulated in the order of the condenser 50, the gas-liquid separator 60, the expansion valve 70, the evaporator 80, and the compressor 10. .

Next, details of the compressor 10 according to the present embodiment will be described with reference to FIGS. 2 and 3. As shown in FIG. 2, the compressor 10 includes a compression mechanism 12 that compresses and discharges the refrigerant.

The compression mechanism 12 has a cylinder block 142, a front housing 144 fixed to one end of the cylinder block 142, and a rear housing 146 fixed to the other end of the cylinder block 142 via a valve plate 16. In the present embodiment, the cylinder block 142, the front housing 144, and the rear housing 146 constitute the housing 14 of the compression mechanism 12.

A control pressure chamber 18 for changing the displacement of the compressor 10 is defined in a region of the housing 14 surrounded by the cylinder block 142 and the front housing 144. The rotary shaft 20 of the compression mechanism 12 is disposed in the housing 14 so as to penetrate the vicinity of the center of the control pressure chamber 18.

The rotating shaft 20 has a tip end on one end side connected to the power transmission device PT. The rotating shaft 20 is rotatably supported by a first radial bearing 144 b disposed in a first shaft hole 144 a formed in the front housing 144 at a circumferential surface on one end side. The rotary shaft 20 is rotatably supported at its other end by a second radial bearing 142 b disposed in a second shaft hole 142 a formed in the cylinder block 142. Although not shown, a shaft seal mechanism for preventing refrigerant leakage from the control pressure chamber 18 is provided between the rotary shaft 20 and the first shaft hole 144a.

The rotating shaft 20 is connected to the lug plate 22 in the control pressure chamber 18. The lug plate 22 is a rotating body that rotates integrally with the rotating shaft 20. The lug plate 22 is supported by a thrust bearing 144 c provided on the inner wall surface of the front housing 144.

Further, the swash plate 24 is accommodated in the control pressure chamber 18. A through hole 242 is provided at a central portion of the swash plate 24, and the rotation shaft 20 is inserted through the through hole 242. A hinge mechanism 26 is provided between the swash plate 24 and the lug plate 22. The swash plate 24 is connected to the lug plate 22 via the hinge mechanism 26 so that the swash plate 24 rotates in synchronization with the rotation shaft 20 and the lug plate 22. Further, the swash plate 24 is configured such that the inclination angle with respect to the rotation shaft 20 is changed along with the sliding movement of the rotation shaft 20 in the axial direction DRax.

A coil spring 25 is wound between the lug plate 22 and the swash plate 24 in the rotation shaft 20. The swash plate 24 is pressed by the biasing force of the coil spring 25 so that its inclination angle is reduced.

Further, a cylindrical member 27 is provided between the swash plate 24 and the cylinder block 142 so as to protrude toward the swash plate 24 from the inner wall surface of the cylinder block 142. The cylindrical member 27 restricts the minimum inclination angle of the swash plate 24 by contacting the swash plate 24.

A plurality of cylinder bores 148 are formed through the cylinder block 142 so as to surround the rotation shaft 20. A single-headed piston 29 is accommodated in the cylinder bore 148 so as to be capable of reciprocating in the axial direction DRax of the rotating shaft 20.

Openings on both axial sides of the cylinder bore 148 are closed by the valve plate 16 and the piston 29. In the cylinder bore 148, a compression chamber 28 whose volume changes in accordance with the movement of the piston 29 in the axial direction DRax is defined. The piston 29 is anchored to the outer peripheral portion of the swash plate 24 via a shoe 30. Then, the rotational movement of the swash plate 24 along with the rotation of the rotational shaft 20 of the compression mechanism 12 is converted to the reciprocating linear movement of the piston 29 via the shoe 30.

A suction chamber 32 and a discharge chamber 34 are defined in the rear housing 146 at a position facing the valve plate 16. The valve plate 16 is provided with a suction port 162 for communicating the suction chamber 32 with the cylinder bore 148, and a suction valve 164 for opening and closing the suction port 162. Further, the valve plate 16 is formed with a discharge port 166 for communicating the discharge chamber 34 with the cylinder bore 148, and a discharge valve 168 for opening and closing the discharge port 166.

Although not shown, a suction passage is formed in the rear housing 146 for communicating the refrigerant flow downstream side of the evaporator 80 and the suction chamber 32 in the refrigeration cycle apparatus 1. Further, the rear housing 146 is formed with a discharge passage for communicating the refrigerant flow upstream side of the condenser 50 with the discharge chamber 34.

The refrigerant flowing into the suction chamber 32 through the suction passage (not shown) is drawn into the compression chamber 28 through the suction port 162 and the suction valve 164 by the movement from the top dead center position to the bottom dead center side of the piston 29. Further, the refrigerant drawn into the compression chamber 28 is compressed to a predetermined pressure by the movement from the bottom dead center position to the top dead center side of the piston 29, and is discharged into the discharge chamber 34 via the discharge port 166 and the discharge valve 168. Ru. Then, the refrigerant discharged into the discharge chamber 34 flows into the condenser 50 through a discharge passage (not shown).

Here, the inclination angle of the swash plate 24 is determined on the basis of the mutual balance of the moment of the rotational movement due to the centrifugal force of the swash plate 24, the moment due to the reciprocal inertia force of the piston 29, the moment due to the pressure of the refrigerant, and the like. The moment due to the pressure of the refrigerant is a moment generated on the basis of the correlation between the pressure in the compression chamber 28 and the pressure in the control pressure chamber 18 acting on the back surface of the piston 29, and corresponds to the pressure fluctuation in the control pressure chamber 18. The inclination angle of the swash plate 24 changes. In the compression mechanism 12, the discharge capacity increases as the inclination angle of the swash plate 24 increases, and the discharge capacity decreases as the inclination angle of the swash plate 24 decreases.

The discharge capacity of the compression mechanism 12 configured as described above is controlled by the capacity control mechanism 40. That is, in the compressor 10 of the present embodiment, the displacement control mechanism 40 controls the pressure of the control pressure chamber 18 to change the inclination angle of the swash plate 24 to change the discharge capacity.

In the housing 14 of the present embodiment, an air supply passage 140 communicating the control pressure chamber 18 with the discharge chamber 34 and a bleed passage 141 communicating the suction chamber 32 with the control pressure chamber 18 are formed.

The displacement control mechanism 40 has an opening adjustment valve 42 for adjusting the passage opening of the air supply passage 140 and a fixed throttle 44 for narrowing the passage opening of the bleed passage 141. The displacement control mechanism 40 is configured to change the displacement of the compression mechanism 12 by adjusting the passage opening degree of the air supply passage 140 by the opening degree adjustment valve 42 and controlling the pressure of the control pressure chamber 18. . The displacement control mechanism 40 of the present embodiment is configured such that the opening degree of the air supply passage 140 is adjusted so that the pressure Ps of the refrigerant drawn into the compression mechanism 12 becomes the target pressure Pso. The opening adjustment valve 42 is attached to the rear housing 146. The structure of the opening adjustment valve 42 of the displacement control mechanism 40 will be described later.

Here, FIG. 3 is an explanatory view for explaining the relationship between the discharge capacity of the compression mechanism 12 and the coefficient of performance (that is, the COP). The horizontal axis of FIG. 3 indicates the discharge capacity, and indicates the state in which the discharge capacity is the minimum capacity at zero percent and the state in which the discharge capacity is the maximum capacity at 100%. The vertical axis of FIG. 3 indicates an annual coefficient of performance that takes into account the yearly use and considers the condition of the heat load and the rotational speed of the compressor 10 that may appear and the frequency of appearance of the condition.

As shown in FIG. 3, the annual coefficient of performance has a peak at about 30% of the discharge capacity, and tends to decrease near the minimum capacity. The main factor is that the refrigerant in the discharge chamber 34 is supplied to the control pressure chamber 18 as a control gas in order to change the discharge capacity. The control gas is supplied from the discharge chamber 34 to the control pressure chamber 18 via the air supply passage 140, then flows to the suction chamber 32 via the bleed passage 141 and is compressed again in the compression chamber 28. That is, the control gas circulates within the housing 14 of the compression mechanism 12. And the work which compressed control gas in compression mechanism 12 turns into extra compression work which does not contribute to cooling of air.

Then, when decreasing the discharge capacity, the amount of control gas increases to increase the pressure of the control pressure chamber 18, and the ratio of the amount of control gas to the amount of refrigerant discharged from the compression mechanism 12 increases. As a result, in the compression mechanism 12, the compression efficiency decreases due to the increase of the control gas circulating in the housing 14 near the minimum displacement, and the annual coefficient of performance decreases with the decrease of the compression efficiency.

Taking these into consideration, the compression mechanism 12 of the present embodiment regulates the minimum inclination angle of the swash plate 24 by the cylindrical member 27 so that the compression mechanism 12 does not operate at the minimum volume where the coefficient of performance decreases. In the present embodiment, the cylindrical member 27 constitutes a capacity limiting portion which limits the lower limit displacement of the discharge capacity of the compression mechanism 12 to an intermediate capacity which is larger than the minimum displacement and smaller than the maximum displacement.

The cylindrical member 27 of the present embodiment has a capacity such that the lower limit capacity of the discharge capacity is larger than when the coefficient of performance is set to the minimum capacity when the compression mechanism 12 is operated in the range from the minimum capacity to the maximum capacity. As a result, the minimum inclination angle of the swash plate 24 is regulated. Specifically, it is desirable to set the lower limit displacement of the discharge displacement in the range of 10% to 50%, so that approximately 30% at which the annual coefficient of performance reaches a peak is included.

Subsequently, the structure of the opening adjustment valve 42 of the displacement control mechanism 40 of the present embodiment will be described with reference to FIG. As shown in FIG. 4, the opening adjustment valve 42 has a valve body 421 for adjusting the opening degree of the air supply passage 140, a suction pressure response mechanism 422 for generating a force F1 corresponding to the pressure of the suction chamber 32, and a suction pressure An electromagnetic mechanism 423 that generates an electromagnetic force F2 opposed to the force F1 of the response mechanism 422 is provided. The opening adjustment valve 42 changes the position of the valve body 421 by balancing the force F1 and the electromagnetic force F2 according to the pressure in the suction chamber 32.

The suction pressure response mechanism 422 is accommodated in a pressure sensing chamber 420 a formed in the valve housing 420, and has a bellows 422 a that can be elastically expanded and contracted in the moving direction of the valve body 421. The pressure of the suction chamber 32 is introduced into the pressure sensing chamber 420a via the pressure introducing passage 420b. In the bellows 422a, a portion fixed to the inner wall surface of the pressure sensing chamber 420a constitutes a fixed end 422b, and a portion opposite to the fixed end 422b constitutes a movable end 422c displaced by elastic expansion and contraction. A push rod 422d is integrally connected to the movable end 422c of the bellows 422a. Although not shown, a spring for pressing the bellows 422a in the extending direction is provided inside the bellows 422a.

On the other hand, the electromagnetic mechanism 423 has an electromagnetic coil 423a, and a plunger 423b is disposed on an inner peripheral portion of the electromagnetic coil 423a so as to be axially displaceable. A movable core 423c is integrally formed at an end of the plunger 423b, and a fixed core 423d is disposed opposite to the movable core 423c. The electromagnetic mechanism 423 is configured to generate an electromagnetic force F2 between the movable iron core 423c and the fixed iron core 423d according to the capacitance control signal value Ic (for example, control current) supplied to the electromagnetic coil 423a. .

Further, a valve body 421 is integrally formed on the end of the plunger 423b opposite to the movable core 423c. Further, a push rod 422 d is integrally connected to the valve body 421. The plunger 423b, the valve body 421, and the push rod 422d of this embodiment are integrally configured, and are integrally displaced in the axial direction of the plunger 423b.

When the electromagnetic force F2 becomes constant, the opening adjustment valve 42 contracts the bellows 422a as the pressure in the suction chamber 32 increases, and the valve body 421 opens the passage opening of the air supply passage 140 accordingly. Displace in the direction to make smaller. As a result, the amount of refrigerant supplied to the control pressure chamber 18 is reduced, whereby the pressure of the control pressure chamber 18 is reduced.

On the other hand, in the opening adjustment valve 42, when the electromagnetic force F2 becomes constant, the bellows 422a extends as the pressure in the suction chamber 32 decreases, and the valve body 421 opens the passage of the air supply passage 140 accordingly. Displace in the direction to increase the degree. As a result, the amount of refrigerant supplied to the control pressure chamber 18 is increased, whereby the pressure of the control pressure chamber 18 is increased.

Here, the opening degree of the air supply passage 140 is determined by the balance of the force F1 and the electromagnetic force F2 according to the pressure of the suction chamber 32. That is, when the displacement control signal value supplied to the electromagnetic coil 423a increases and the electromagnetic force F2 becomes larger than the force F1 corresponding to the pressure in the suction chamber 32, the valve body 421 sets the passage opening degree of the air supply passage 140 Displace in the direction to make smaller. As a result, the amount of refrigerant supplied to the control pressure chamber 18 is reduced, whereby the pressure of the control pressure chamber 18 is reduced. As a result, when the inclination angle of the swash plate 24 is increased, the discharge displacement is increased.

On the other hand, when the displacement control signal value Ic supplied to the electromagnetic coil 423a decreases and the electromagnetic force F2 becomes smaller than the force F1 corresponding to the pressure in the suction chamber 32, the valve body 421 opens the passage of the air supply passage 140. Displace in the direction to make As a result, the amount of refrigerant supplied to the control pressure chamber 18 is increased, whereby the pressure of the control pressure chamber 18 is increased. As a result, as the inclination angle of the swash plate 24 becomes smaller, the discharge displacement becomes smaller.

The displacement control mechanism 40 configured in this manner has a configuration in which the opening degree of the air supply passage 140 is determined by the balance of the force F1, the electromagnetic force F2, etc. according to the pressure of the suction chamber 32. The capacitance may change independently of the capacitance control signal value Ic.

Next, an outline of the control device 100 of the present embodiment will be described. The control device 100 shown in FIG. 1 is composed of a known microcomputer including a processor, a memory and the like and its peripheral circuit. The memory is configured of a non-transitional tangible storage medium.

The control device 100 compresses the sensor detection signals from the air conditioning sensor groups 101 to 105 and various control signals from the various air conditioning operation switches provided on the air conditioning operation panel 110 disposed near the instrument panel in the front of the vehicle compartment. It controls various devices including the machine 10. Further, the control device 100 stores a control program and the like of an air conditioning control device and the like in a memory, and performs various arithmetic processing based on the control program and the like.

As the air conditioning sensor group, an outside air sensor 101 for detecting the outside air temperature Tam, an inside air sensor 102 for detecting the inside air temperature Tr, a sunshine sensor 103 for detecting the amount of solar radiation Ts entering the vehicle interior, the above-mentioned evaporator temperature sensor 104, A compressor rotational speed sensor 105 and the like are provided. As evaporator temperature sensor 104, a temperature sensor which detects temperature of a heat exchange fin of evaporator 80 as blow-off temperature TE, for example can be adopted.

The compressor rotational speed sensor 105 is a sensor that detects the rotational speed Ne of the compressor 10. The compressor rotation number sensor 105 is not limited to one that directly detects the rotation number Ne of the compressor 10, and may be configured to calculate the rotation number Ne of the compressor 10 from the engine rotation number, for example.

As various air conditioning operation switches provided on the air conditioning operation panel 110, an air conditioner switch for issuing an operation command signal of the compressor 10, a temperature setting switch serving as temperature setting means for setting a set temperature Tset of a vehicle compartment, and the like are provided.

Further, a clutch MGC, a displacement control mechanism 40 and the like are connected to an output side of the control device 100 via drive circuits (not shown) for driving various actuators which are peripheral circuits. The various devices are controlled by the output signal of the control device 100.

Next, the operation of the compressor 10 of the present embodiment will be described. In the compressor 10 of the present embodiment, the lower limit displacement of the discharge displacement is set not to the minimum displacement but to the intermediate displacement in order to avoid the operation at the minimum displacement at which the compression efficiency decreases.

Here, if the lower limit capacity of the discharge capacity is simply limited to an intermediate capacity larger than the minimum capacity, the variable range of the discharge capacity becomes smaller, for example, the air cooling capacity in the evaporator 80 becomes excessive. Are concerned.

Therefore, the compressor 10 of the present embodiment is configured to switch the operation mode of the compression mechanism 12 to the variable operation mode and the intermittent operation mode by the control device 100. The variable operation mode is an operation mode in which the displacement control mechanism 40 changes the discharge displacement in the range from the lower limit displacement to the maximum displacement with the clutch MGC controlling the engine EG and the compression mechanism 12 in a connected state. The intermittent operation mode is an operation mode in which the engine EG and the compression mechanism 12 are intermittently switched between the connected state and the disconnected state by the clutch MGC while the displacement control mechanism 40 controls the discharge displacement to the lower limit displacement.

Hereinafter, control processing for switching the operation mode performed by the control device 100 will be described with reference to FIG. 5 and the like. Each control step of the control process shown in FIG. 5 constitutes a function implementing unit that implements various functions executed by the control device 100.

When the air conditioner switch is turned on while the engine EG is in operation, control device 100 controls clutch MGC to the on state and executes the control process shown in FIG. 5 after setting the initial setting of the operation mode to the variable operation mode. Do. The control process shown in FIG. 5 is executed by the control device 100 at a predetermined cycle.

As shown in FIG. 5, in step S10, the control device 100 reads various signals from the air conditioning sensor groups 101 to 105 connected to the input side and the air conditioning operation panel 110. Subsequently, in step S20, the control device 100 calculates a target blowout temperature TAO of air blown into the vehicle compartment. The target blowout temperature TAO is a blowout temperature required to maintain the passenger compartment at the set temperature Tset of the temperature setting switch, and is calculated based on the following formula F1.

TAO = Kset × Tset−Kr × Tr−Kam × Tam−Ks × Ts + C (F1)
In the symbols shown in the above-mentioned Formula F1, Tset represents a set temperature, Tr represents an internal temperature, Tam represents an external temperature, Ts represents a solar radiation amount, and Kset, Kr, Kam, and Ks represent control gains. C is a constant for correction.

Subsequently, in step S30, the control device 100 calculates the target evaporator temperature TEO of the blowout temperature TE of the air blown out from the evaporator 80. Specifically, control device 100 refers to a control map that defines the correspondence between target air outlet temperature TAO and target evaporator temperature TEO, and determines target evaporator temperature TEO from target air outlet temperature TAO calculated in step S20. calculate. In the control map, the target evaporator temperature TEO is associated with the target outlet temperature TAO such that the target evaporator temperature TEO increases as the target outlet temperature TAO increases. The control map is stored in advance in the memory.

Subsequently, in step S40, the control device 100 calculates a variable signal value Ic_cal which is a first candidate of the capacitance control signal value Ic to be output to the capacitance control mechanism 40. The variable signal value Ic_cal is calculated by feedback control such as PI control or PID control so that the outlet temperature TE of the evaporator 80 approaches the target evaporator temperature TEO.

Subsequently, in step S50, the control device 100 determines whether the current operation mode of the compression mechanism 12 is the variable operation mode or the intermittent operation mode. As a result of the determination process, when the operation mode is the variable operation mode, the control device 100 proceeds to step S60 and executes the variable operation process. When the operation mode is the intermittent operation mode, the control device 100 proceeds to step S70 and executes the intermittent operation process.

In the present embodiment, after the flow of the variable operation process is described with reference to the flowchart of FIG. 6, the flow of the intermittent operation process is described with reference to the flowchart of FIG. The control steps of the control process shown in FIGS. 6 and 13 constitute a function implementing unit that implements various functions executed by the control device 100.

In the variable operation process, as shown in FIG. 6, the control device 100 determines in step S100 whether or not the blowout temperature TE of the evaporator 80 is smaller than the target evaporator temperature TEO. When the blowout temperature TE of the evaporator 80 becomes equal to or higher than the target evaporator temperature TEO, by operating the compression mechanism 12 in the variable operation mode, the state where the cooling capacity of the evaporator 80 can be properly maintained or the evaporator 80 is cooled It is considered that there is a lack of ability due to lack of ability.

Therefore, when the blowout temperature TE of the evaporator 80 becomes equal to or higher than the target evaporator temperature TEO, the control device 100 maintains the clutch MGC in the on state in step S110. Further, in step S120, the control device 100 determines the capacitance control signal value Ic as the variable signal value Ic_cal calculated in step S40 of FIG. Then, at step S130, control device 100 operates compression mechanism 12 in the variable operation mode. That is, the control device 100 outputs the variable signal value Ic_cal to the capacitance control mechanism 40 as the capacitance control signal value Ic.

Here, the displacement control mechanism 40 controls the opening adjustment valve 42 such that the passage opening degree of the air supply passage 140 decreases as the displacement control signal value Ic increases. For example, when the displacement control signal value Ic is large, the displacement control mechanism 40 controls the opening adjustment valve 42 so that the passage opening degree at which the air supply passage 140 is closed as shown in FIG. 7. In this case, in the compression mechanism 12, the pressure of the control pressure chamber 18 is reduced by stopping the supply of the refrigerant from the discharge chamber 34 to the control pressure chamber 18. As a result, as shown in FIG. 8, in the compression mechanism 12, the displacement of the swash plate 24 increases to the maximum displacement as the inclination angle of the swash plate 24 becomes the maximum inclination angle.

On the other hand, when the displacement control signal value Ic is small, as shown in FIG. 9, the displacement control mechanism 40 controls the opening adjustment valve 42 so that the passage opening degree at which the air supply passage 140 is fully opened. . In this case, in the compression mechanism 12, the pressure of the control pressure chamber 18 is increased by the increase of the supply amount of the refrigerant from the discharge chamber 34 to the control pressure chamber 18. As a result, as shown in FIG. 10, in the compression mechanism 12, the displacement of the swash plate 24 is reduced to the lower limit by the minimum inclination angle. In the compression mechanism 12 of the present embodiment, the lower limit displacement of the discharge displacement is limited by the cylindrical member 27 to an intermediate displacement. For this reason, in the variable operation mode, the compression mechanism 12 is not operated at the minimum capacity with low compression efficiency.

Returning to FIG. 6, when the blowout temperature TE of the evaporator 80 is smaller than the target evaporator temperature TEO in the determination process of step S100, the control device 100 determines that the variable signal value Ic_cal is a predetermined lower limit signal in step S140. It is determined whether the value is equal to or less than the value Ic_min. The lower limit signal value Ic_min is a determination threshold for determining whether or not the discharge displacement of the compression mechanism 12 is the lower limit displacement from the displacement control signal value Ic.

Here, when using the displacement control mechanism 40 that controls the pressure Ps of the refrigerant sucked into the compression mechanism 12 to be the target pressure Pso as in the present embodiment, the blowout temperature TE of the evaporator 80 and the displacement control signal value The Ic has a correlation as shown in FIG. In the present embodiment, the displacement control signal value Ic corresponding to the target evaporator temperature TEO is identified based on a control map in which the blowout temperature TE and the displacement control signal value Ic are associated in advance, and the identified displacement control signal value Ic is greater than the identified displacement control signal value Ic. The lower value is set to the lower limit signal value Ic_min.

As described above, the discharge capacity of the compression mechanism 12 may change depending on the heat load on the air side of the evaporator 80 regardless of the capacity control signal value Ic. Therefore, in the present embodiment, the lower limit signal value Ic_min is set as a variable threshold value corresponding to the target evaporator temperature TEO which changes in correlation with the heat load on the air side of the evaporator 80. Specifically, as shown in FIG. 12, the lower limit signal value Ic_min is a variable threshold that decreases with the increase of the target evaporator temperature TEO.

Returning to FIG. 6, when the variable signal value Ic_cal becomes larger than the lower limit signal value Ic_min in step S140, it is considered that the discharge displacement of the compression mechanism 12 is not the lower limit displacement. In this case, the control device 100 proceeds to step S110 and maintains the operation mode in the variable operation mode.

On the other hand, when the variable signal value Ic_cal becomes equal to or less than the lower limit signal value Ic_min in step S140, it is considered that the discharge displacement of the compression mechanism 12 is the lower limit displacement. In this case, even if the discharge capacity of the compression mechanism 12 becomes the lower limit capacity, it is considered that the cooling capacity of the evaporator 80 satisfies the required cooling capacity required. Thus, the control device 100 proceeds to step S150 and maintains the clutch MGC in the on state. Further, in step S160, control device 100 determines capacitance control signal value Ic as lower limit signal value Ic_min. Then, in step S170, the control device 100 operates the compression mechanism 12 in the intermittent operation mode. That is, the control device 100 outputs the lower limit signal value Ic_min to the capacitance control mechanism 40 as the capacitance control signal value Ic.

The above is the description of the variable driving process. Hereinafter, the flow of the intermittent operation process will be described with reference to the flowchart of FIG. The intermittent operation process shown in FIG. 13 is a process executed in step S70 of FIG.

As shown in FIG. 13, in step S200, control device 100 determines whether or not clutch MGC is in the on state. As a result, when it is determined that the clutch MGC is in the on state, the control device 100 determines in step S210 whether or not the outlet temperature TE of the evaporator 80 is smaller than a predetermined off-side threshold Toff. The off-side threshold Toff is a determination threshold for switching the clutch MGC from the on state to the off state. The off-side threshold Toff is, as shown in FIG. 14, set to a temperature lower than the target evaporator temperature TEO in order to avoid frequent switching of the clutch MGC.

If the outlet temperature TE of the evaporator 80 is smaller than the off-side threshold Toff, the control device 100 sets the clutch MGC to the off state in step S220. Thereby, the operation of the compression mechanism 12 is stopped.

Further, in step S230, control device 100 determines the capacitance control signal value as the lower limit signal value Ic_min. Then, in step S240, control device 100 maintains the operation mode of compression mechanism 12 in the intermittent operation mode, and resets timer counter t_cnt in step S250.

Here, in the intermittent operation mode, the timer counter t_cnt measures a period in which the cooling capacity of the evaporator 80 is insufficient for the required cooling capacity which is required even if the clutch MGC is switched to the on state. Is a counter for

If the blowout temperature TE of the evaporator 80 is smaller than the off-side threshold Toff, the controller 100 is not in the capability shortage state, so the control device 100 resets the timer counter t_cnt in step S250.

On the other hand, when the blowout temperature TE of the evaporator 80 is larger than the off-side threshold Toff, the control device 100 determines whether the blowout temperature TE of the evaporator 80 is larger than the target evaporator temperature TEO in step S260. .

As a result, when the blowout temperature TE of the evaporator 80 is larger than the target evaporator temperature TEO, the control device 100 determines whether or not the timer counter t_cnt is equal to or more than a preset reference time t_set in step S270. Do.

When the timer counter t_cnt is equal to or more than a preset reference time t_set, it is considered that the capacity shortage state of the evaporator 80 can not be avoided even if the intermittent operation mode is continued. Therefore, control device 100 maintains clutch MGC in the on state in step S280, and determines the displacement control signal value as variable signal value Ic_cal in step S290. Then, in step S300, control device 100 switches the operation mode of compression mechanism 12 to the variable operation mode, and resets timer counter t_cnt in step S250.

Here, when the outlet temperature TE of the evaporator 80 is determined to be equal to or lower than the target evaporator temperature TEO in step S260, the control device 100 proceeds to step S310. Also, when it is determined in step S270 that the timer counter t_cnt is less than the reference time t_set, the control device 100 causes the process to proceed to step S310. Then, control device 100 maintains clutch MGC in the on state in step S310, and determines the displacement control signal value as lower limit signal value Ic_min in step S320. In step S330, control device 100 maintains the operation mode of compression mechanism 12 in the intermittent operation mode.

On the other hand, when it is determined in the determination process of step S200 that the clutch MGC is in the off state, the control device 100 determines that the outlet temperature TE of the evaporator 80 is higher than the predetermined on side threshold value Ton in step S340. It is determined whether or not it is large. The on-side threshold Ton is a determination threshold for switching the clutch MGC from the off state to the on state. As shown in FIG. 14, the on-side threshold Ton is set to a temperature higher than the target evaporator temperature TEO in order to avoid frequent switching of the clutch MGC.

If the blowout temperature TE of the evaporator 80 is larger than the on-side threshold Ton, the control device 100 sets the clutch MGC to the on state in step S350. Thereby, the operation of the compression mechanism 12 is resumed.

Further, in step S360, control device 100 determines the capacity control signal value as the lower limit signal value Ic_min. Then, control device 100 maintains the operation mode of compression mechanism 12 in the intermittent operation mode in step S370, and starts counting of timer counter t_cnt in step S380.

On the other hand, when the blowout temperature TE of the evaporator 80 becomes equal to or less than the on-side threshold Ton, the control device 100 sets the clutch MGC to the off state in step S390. Thereby, the operation of the compression mechanism 12 is maintained in the stop state.

Further, in step S400, control device 100 determines the capacitance control signal value as the lower limit signal value Ic_min. Then, in step S410, control device 100 maintains the operation mode of compression mechanism 12 in the intermittent operation mode.

By the above control process, the compressor 10 can switch the operation mode to either the variable operation mode or the intermittent operation mode. That is, even if the control device 100 according to the present embodiment sets the discharge capacity to the lower limit capacity, a case where the air cooling capacity in the evaporator 80 satisfies the required cooling capacity required for the evaporator 80 is satisfied. Switch from the variable operation mode to the intermittent operation mode. Further, even if the control device 100 sets the discharge capacity to the lower limit capacity, the operation mode is satisfied when the capacity insufficient condition for the cooling capacity of the air in the evaporator 80 is insufficient for the required cooling capacity required for the evaporator 80 is satisfied. From the intermittent operation mode to the variable operation mode.

Here, FIG. 15 shows the outlet temperature TE of the evaporator 80, the capacity control signal value Ic, the on / off state of the clutch MGC, the discharge capacity, etc. when the operation mode changes in the order of variable operation mode, intermittent operation mode, variable operation mode. It is a timing chart which shows an example of change.

As shown in FIG. 15, when the blowout temperature TE of the evaporator 80 decreases to near the target evaporator temperature TEO while the compression mechanism 12 is operated in the variable operation mode, the capacity control signal value Ic decreases and the discharge is performed. The capacity also decreases (t0 to t1 in FIG. 15).

Then, when the blowout temperature TE falls to a temperature lower than the target evaporator temperature TEO and the variable signal value Ic_cal falls to the lower limit signal value Ic_min, the operation mode switches from the variable operation mode to the intermittent operation mode (t1 in FIG. 15 → t2). As a result, the displacement control signal value Ic is determined to be the lower limit signal value Ic_min, and the discharge displacement becomes the lower limit displacement.

After switching from the variable operation mode to the intermittent operation mode, when the blow-out temperature TE becomes lower than the off-side threshold Toff, the clutch MGC switches from the on state to the off state (t2 → t3 in FIG. 15). As a result, when the operation of the compression mechanism 12 is stopped, the blowout temperature TE rises.

Then, when the blow-out temperature TE rises to a temperature higher than the on-side threshold Ton, the clutch MGC is switched from the off state to the on state (t3 → t4 in FIG. 15). As a result, when the operation of the compression mechanism 12 is resumed, the blowout temperature TE is lowered.

When the operation of compression mechanism 12 is resumed and blowout temperature TE attains a temperature lower than off-side threshold Toff again in a time shorter than reference time t_set, clutch MGC is switched from the on state to the off state (t4 → t5 in FIG. 15). ).

As described above, in the intermittent operation mode, the blowing temperature TE is maintained near the target evaporator temperature TEO by switching the clutch MGC on and off in a state where the discharge displacement is controlled to be the lower limit displacement.

Then, in the intermittent operation mode, in a state where the clutch MGC is maintained in the on state, the operation mode is changed from the intermittent operation mode to the variable operation mode when the capacity insufficient state in which the cooling capacity of the evaporator 80 is insufficient continues for a predetermined time. Switch to That is, if the blowout temperature TE exceeds the target evaporator temperature TEO until the reference time t_set after the clutch MGC is switched to the ON state, the operation mode switches from the intermittent operation mode to the variable operation mode (tn in FIG. 15 → tn + 1). As a result, the displacement control signal value Ic is determined as the variable signal value Ic_cal while the clutch MGC is maintained in the on state, whereby the blowout temperature TE is controlled to approach the target evaporator temperature TEO.

In the compressor 10 according to the present embodiment described above, since the lower limit of the discharge capacity of the compression mechanism 12 is limited to an intermediate capacity larger than the minimum capacity by the cylindrical member 27 which is a capacity limiting portion, the compression efficiency is low. The operation of the compression mechanism 12 at the minimum capacity can be avoided. Moreover, since the compressor 10 of this embodiment can switch the operation mode to the variable operation mode and the intermittent operation mode, it is possible to avoid the problem caused by the decrease of the variable range of the discharge capacity by the switching of the operation mode. It becomes. That is, according to the compressor 10 of the present embodiment, the compression efficiency can be improved while appropriately exhibiting the cooling capacity of the evaporator 80.

In particular, the compression mechanism 12 of the present embodiment is set to a capacity whose lower limit capacity is larger than that in the case where the coefficient of performance is set to the minimum capacity when the compression mechanism 12 is operated. According to this, it is possible to increase the coefficient of performance in the intermittent operation mode as compared with the case of operating with the minimum capacity.

Further, in the control device 100 according to the present embodiment, even when the discharge capacity is set to the lower limit capacity, a capacity satisfying condition satisfying the required cooling capacity required of the evaporator 80 for the air cooling capacity in the evaporator 80 is satisfied. Switch from the variable operation mode to the intermittent operation mode. According to this, since it is possible to prevent the cooling capacity of the air in the evaporator 80 from becoming excessive, it is possible to improve the compression efficiency while appropriately exhibiting the cooling capacity in the evaporator 80.

Here, the capability satisfaction condition is a condition that is satisfied when the blowout temperature TE of the evaporator 80 is lower than the target evaporator temperature TEO and the variable signal value Ic_cal is equal to or less than the lower limit signal value Ic_min. However, the lower limit signal value Ic_min is a variable threshold that becomes smaller as the target evaporator temperature TEO rises. According to this, it is avoided that the variable operation mode is switched to the intermittent operation mode when the outlet temperature TE of the evaporator 80 becomes equal to or higher than the target evaporator temperature TEO, that is, the cooling capacity of the evaporator 80 is insufficient. can do.

Furthermore, in the control device 100 according to the present embodiment, even when the discharge capacity is set to the lower limit capacity, a capacity shortage condition in which the cooling capacity of air in the evaporator 80 is insufficient for the required cooling capacity required for the evaporator 80 is satisfied. To the variable operation mode from the intermittent operation mode. According to this, since it is possible to avoid the shortage of the cooling capacity of air in the evaporator, it is possible to improve the compression efficiency while properly exhibiting the cooling capacity in the evaporator.

Here, the insufficient capability condition is a condition that is satisfied when a state in which the outlet temperature TE of the evaporator 80 is higher than the target evaporator temperature TEO continues for a predetermined period while the connected state is controlled to the connected state by the clutch MGC. It has become. As described above, if the condition of insufficient capability is a condition that is satisfied when the state where the outlet temperature TE of the evaporator 80 is higher than the target evaporator temperature TEO is maintained for a predetermined period, the intermittent operation mode to the variable operation mode Frequent switching can be suppressed.

Second Embodiment
Next, a second embodiment will be described with reference to FIG. 16 to FIG. In this embodiment, in the intermittent operation mode, the amount of refrigerant circulated through the air supply passage 140, the control pressure chamber 18, and the extraction passage 141 is smaller than in the variable operation mode. It is different from the first embodiment in that it is configured.

As shown in FIGS. 16 to 18, the displacement control mechanism 40 of the present embodiment has a displacement control valve 45 capable of adjusting both the passage opening degree of the air supply passage 140 and the passage opening degree of the bleed passage 141. There is. The displacement control mechanism 40 controls the pressure of the control pressure chamber 18 by adjusting the passage opening degree of the air supply passage 140 and the passage opening degree of the bleed passage 141 by the displacement control valve 45 to control the displacement of the compression mechanism 12. It is configured to change.

The displacement control valve 45 has a three-way valve type valve structure. The volume control valve 45 includes a valve body 451 for adjusting the passage opening degree of the air supply passage 140 and the passage opening degree of the extraction passage 141, a suction pressure response mechanism 452 for generating force corresponding to the pressure of the suction chamber 32, and suction pressure response mechanism. It has an electromagnetic mechanism 453 which generates an electromagnetic force opposite to the force of the mechanism 452. The suction pressure response mechanism 452 is configured in the same manner as the suction pressure response mechanism 422 described in the first embodiment. The electromagnetic mechanism 453 is configured in the same manner as the electromagnetic mechanism 423 described in the first embodiment.

In the capacity control valve 45, the passage opening degree of the bleed passage 141 decreases as the passage opening degree of the air supply passage 140 increases, and as the passage opening degree of the air supply passage 140 decreases, the passage opening degree of the bleed passage 141 increases. It is configured to be Specifically, the capacity control valve 45 is configured to open the air supply passage 140 and close the bleed passage 141 in the intermittent operation mode.

When the displacement control signal value Ic supplied to the electromagnetic mechanism 453 decreases and the electromagnetic force becomes smaller than the force corresponding to the pressure in the suction chamber 32, for example, as shown in FIG. , The bleed passage 141 is closed and the air supply passage 140 is displaced to the open position. As a result, the amount of refrigerant supplied to the control pressure chamber 18 is increased, whereby the pressure of the control pressure chamber 18 is increased. As a result, as the inclination angle of the swash plate 24 becomes smaller, the discharge capacity is reduced.

Also, when the displacement control signal value Ic supplied to the electromagnetic mechanism 453 increases from the state shown in FIG. 16, for example, as shown in FIG. 17, the valve body 451 of the displacement control valve 45 Move both 141 to the open position.

Furthermore, when the displacement control signal value Ic supplied to the electromagnetic mechanism 453 increases and the electromagnetic force becomes larger than the force corresponding to the pressure in the suction chamber 32, for example, as shown in FIG. Body 451 opens bleed passage 141 and displaces air supply passage 140 to a closed position. As a result, the amount of refrigerant supplied to the control pressure chamber 18 is reduced, whereby the pressure of the control pressure chamber 18 is reduced. As a result, when the inclination angle of the swash plate 24 is increased, the discharge capacity is increased.

Other configurations and operations are similar to those of the first embodiment. The compressor 10 of the present embodiment can obtain the same effects and advantages as those of the first embodiment from the same configuration and operation as those of the first embodiment.

In particular, in the present embodiment, the displacement control mechanism 40 includes the displacement control valve 45 that opens the air supply passage 140 and closes the bleed passage 141 in the intermittent operation mode. According to this, since it is possible to stop the circulation of the refrigerant inside the housing 14 in the intermittent operation mode, it is possible to further improve the compression efficiency.

Here, FIG. 19 shows the case where the compressor operated only in the variable operation mode is a comparative example, the compressor 10 of the first embodiment is a first example, and the compressor 10 of this embodiment is a second example. It is a figure which shows the motive power of the compressor 10. Moreover, FIG. 20 is a figure which shows the coefficient of performance of a comparative example, 1st Example, and 2nd Example. Note that the power shown in FIG. 19 and the coefficient of performance shown in FIG. 20 indicate the conditions of the heat load and the rotational speed of the compressor 10 that may appear and the frequency of appearance of the conditions, assuming the actual use. There is.

In the first embodiment and the second embodiment, unlike the comparative example, the compressor 10 may stop in the intermittent operation mode. For this reason, as shown in FIG. 19, the power of the compressor is smaller in the first embodiment and the second embodiment than in the comparative example. The coefficient of performance is higher in the first embodiment and the second embodiment than in the comparative example, as shown in FIG.

In the second embodiment, unlike the first embodiment, the bleed passage 141 is closed in the open state of the air supply passage 140 in the intermittent operation mode, so that it is accompanied by the circulation of the refrigerant in the housing 14 in the intermittent operation mode. Loss is suppressed. For this reason, as shown in FIG. 19, the power of the compressor is smaller in the second embodiment than in the first embodiment. As shown in FIG. 20, the coefficient of performance is higher in the second embodiment than in the first embodiment.

Third Embodiment
Next, a third embodiment will be described with reference to FIG. The present embodiment is different from the first embodiment in that the displacement control mechanism 40 is configured to adjust the passage opening degree of the bleed passage 141 to control the pressure of the control pressure chamber 18.

As shown in FIG. 21, the displacement control mechanism 40 has a fixed throttle 46 for reducing the passage opening degree of the air supply passage 140 and an opening adjustment valve 47 for adjusting the passage opening degree of the bleed passage 141. The displacement control mechanism 40 is configured to change the discharge displacement of the compression mechanism 12 by adjusting the opening degree of the bleed passage 141 by the opening adjustment valve 47 and controlling the pressure of the control pressure chamber 18. The displacement control mechanism 40 of this embodiment is configured such that the passage opening degree of the opening degree adjustment valve 47 is adjusted so that the pressure of the refrigerant drawn into the compression mechanism 12 becomes the target pressure.

Although not shown, the opening adjustment valve 47 is a valve element for adjusting the opening of the bleed passage 141, a suction pressure response mechanism for generating a force corresponding to the pressure of the suction chamber 32, and a force corresponding to the force of the suction pressure response mechanism. It has an electromagnetic mechanism that generates an electromagnetic force. The opening control valve 47 is configured to be able to close the bleed passage 141. The suction pressure response mechanism and the electromagnetic mechanism are configured in the same manner as the suction pressure response mechanism 422 and the electromagnetic mechanism 423 described in the first embodiment.

When the displacement control signal value Ic supplied to the electromagnetic mechanism decreases and the electromagnetic force becomes smaller than the force corresponding to the pressure in the suction chamber 32, the opening adjustment valve 47, for example, a position where the valve body closes the bleed passage 141 Displace. As a result, the amount of refrigerant flowing from the control pressure chamber 18 to the suction chamber 32 is reduced, whereby the pressure in the control pressure chamber 18 is increased. As a result, as the inclination angle of the swash plate 24 becomes smaller, the discharge capacity is reduced.

Further, the opening adjustment valve 47 opens the bleed passage 141 when the displacement control signal value Ic supplied to the electromagnetic mechanism 453 increases and the electromagnetic force becomes larger than the force corresponding to the pressure of the suction chamber 32. Displace to position. As a result, the amount of refrigerant flowing from the control pressure chamber 18 to the suction chamber 32 increases, and the pressure in the control pressure chamber 18 decreases. As a result, when the inclination angle of the swash plate 24 is increased, the discharge capacity is increased.

In particular, in the present embodiment, the displacement control mechanism 40 is configured to include the opening adjustment valve 47 capable of closing the bleed passage 141. According to this, since it is possible to stop the circulation of the refrigerant inside the housing 14 in the intermittent operation mode, it is possible to further improve the compression efficiency.

Fourth Embodiment
Next, a fourth embodiment will be described with reference to FIG. The present embodiment is different from the first embodiment in that a pressure responsive valve 48 is disposed in place of the fixed throttle 44 with respect to the bleed passage 141.

As shown in FIG. 22, the displacement control mechanism 40 is configured to include two valves such as an opening degree adjusting valve 42 and a pressure responsive valve 48. The pressure responsive valve 48 is configured to reduce the opening degree of the bleed passage 141 as the pressure difference between the discharge chamber 34 and the control pressure chamber 18 decreases. The pressure difference between the discharge chamber 34 and the control pressure chamber 18 decreases as the passage opening degree of the air supply passage 140 increases, and increases as the passage opening degree of the air supply passage 140 decreases. For this reason, the pressure responsive valve 48 is configured to reduce the passage opening degree of the bleed passage 141 as the passage opening degree of the air supply passage 140 increases. The pressure responsive valve 48 is configured to be able to close the bleed passage 141.

In particular, in the present embodiment, the displacement control mechanism 40 is configured to include the pressure responsive valve 48 capable of closing the bleed passage 141. According to this, since it is possible to stop the circulation of the refrigerant inside the housing 14 in the intermittent operation mode, it is possible to further improve the compression efficiency.

Fifth Embodiment
Next, a fifth embodiment will be described with reference to FIGS. 23 and 24. FIG. In the present embodiment, the capacity control mechanism 40 is configured such that the opening degree of the air supply passage 140 is adjusted so that the flow rate Gr of the refrigerant discharged from the compression mechanism 12 becomes the target flow rate Gro. It is different from the one embodiment.

As shown in FIG. 23, the displacement control mechanism 40 has an opening adjustment valve 49 for adjusting the passage opening of the air supply passage 140 and a fixed throttle 44 for narrowing the passage opening of the bleed passage 141. The opening adjustment valve 49 includes a valve 491, a throttling portion 492 for throttling the outlet side of the discharge chamber 34, a differential pressure response mechanism 493 that generates a force corresponding to the differential pressure ΔP generated before and after the throttle portion 492, a differential pressure response mechanism An electromagnetic mechanism 494 that generates an electromagnetic force opposing to the force of 493 is provided. The electromagnetic mechanism 494 is configured in the same manner as the electromagnetic mechanism 423 of the first embodiment.

Here, the differential pressure ΔP generated before and after the throttle portion 492 is in proportion to the flow rate of the refrigerant discharged from the compression mechanism 12. Therefore, it becomes possible to control the flow rate of the refrigerant discharged from the compression mechanism 12 by controlling the differential pressure ΔP.

The differential pressure response mechanism 493 is accommodated in a differential pressure introducing chamber 490a formed in the valve housing 490, and has a bellows 493a elastically extendable in the moving direction of the valve body 491. The pressure on the downstream side of the narrowed portion 492 is introduced into the differential pressure introduction chamber 490a via the first pressure introduction passage 490b. In the bellows 493a, a portion fixed to the inner wall surface of the differential pressure introducing chamber 490a constitutes a fixed end 493b, and a portion opposite to the fixed end 493b constitutes a movable end 493c displaced by elastic expansion and contraction. The pressure on the upstream side of the throttle portion 492 acts on the fixed end 493 b of the bellows 493 a via the second pressure introduction passage 490 c. Further, a push rod 493 d is integrally connected to a movable end 493 c of the bellows 493 a. Although not shown, a spring for pressing the bellows 493a in the extending direction is provided inside the bellows 493a.

When the electromagnetic force is constant, the opening adjustment valve 49 shrinks the bellows 493a as the differential pressure ΔP increases, and the valve body 491 reduces the opening degree of the air supply passage 140 accordingly. Displace. As a result, the amount of refrigerant supplied to the control pressure chamber 18 is reduced, whereby the pressure of the control pressure chamber 18 is reduced.

On the other hand, in the opening adjustment valve 49, when the electromagnetic force becomes constant, the bellows 493a expands as the differential pressure ΔP decreases, and the valve body 491 increases the opening degree of the air supply passage 140 accordingly. Displace in the direction of As a result, the amount of refrigerant supplied to the control pressure chamber 18 is increased, whereby the pressure of the control pressure chamber 18 is increased.

Here, the passage opening degree of the air supply passage 140 is determined by the balance of the force F1 and the electromagnetic force F2 according to the pressure difference ΔP. That is, when the displacement control signal value Ic supplied to the electromagnetic mechanism 494 increases and the electromagnetic force F2 becomes larger than the force F1 according to the differential pressure ΔP, the valve 491 reduces the opening degree of the air supply passage 140. Displace in the direction of As a result, the amount of refrigerant supplied to the control pressure chamber 18 is reduced, whereby the pressure of the control pressure chamber 18 is reduced. As a result, when the inclination angle of the swash plate 24 is increased, the discharge displacement is increased.

On the other hand, when the displacement control signal value Ic supplied to the electromagnetic mechanism 494 decreases and the electromagnetic force F2 becomes smaller than the force F1 corresponding to the differential pressure ΔP, the valve body 421 increases the opening degree of the air supply passage 140 Displace in the direction of As a result, the amount of refrigerant supplied to the control pressure chamber 18 is increased, whereby the pressure of the control pressure chamber 18 is increased. As a result, as the inclination angle of the swash plate 24 becomes smaller, the discharge displacement becomes smaller.

Next, the variable driving process performed by the control device 100 of the present embodiment will be described with reference to FIG. FIG. 24 corresponds to FIG. 6 of the first embodiment. In FIG. 24, the same steps as those in FIG. 6 are denoted by the same reference numerals as those in the first embodiment.

As shown in FIG. 6, the control device 100 calculates the flow rate Gr_cal of the refrigerant discharged from the compression mechanism 12 in step S102. The flow rate Gr of the refrigerant changes in proportion to the capacity control signal value Ic. Therefore, the control device 100 refers to the control map that defines the correspondence between the variable signal value Ic_cal and the flow rate Gr_cal of the refrigerant, and based on the variable signal value Ic_cal calculated in step S40 of FIG. Calculate

Subsequently, the control device 100 calculates the density 100_cal of the refrigerant drawn into the compression mechanism 12 in step S104. The density __cal of the refrigerant drawn into the compression mechanism 12 is determined by the temperature and pressure of the refrigerant drawn into the compression mechanism 12. The temperature and pressure of the refrigerant drawn into the compression mechanism 12 are correlated with the temperature TE of the evaporator 80. For this reason, the control device 100 refers to a control map that defines the correspondence between the blowout temperature TE of the evaporator 80 and the density __cal of the refrigerant drawn into the compression mechanism 12, and based on the blowout temperature TE of the evaporator 80. The density ρ_cal of the refrigerant drawn into the compression mechanism 12 is calculated.

Subsequently, the control device 100 estimates the displacement of the discharge capacity of the compression mechanism 12 based on the flow rate Gr_cal of the refrigerant at step S106, the density __cal of the refrigerant sucked into the compression mechanism 12, and the rotational speed Ne of the compression mechanism 12. Calculate V.

Control device 100 estimates estimated capacity V, for example, using the following formula F2.

V = Gr_cal / (ρ_cal × Ne × η) (F2)
However, η shown in Formula F2 is volumetric efficiency in the compression mechanism 12, and is set to a predetermined value. The volumetric efficiency η may be determined based on the rotational speed Ne because the rotational speed Ne of the compression mechanism 12 has a large influence.

Subsequently, in step S108, the control device 100 determines whether the estimated capacity V is equal to or less than the lower limit capacity V_min. As a result, when the estimated displacement V of the compression mechanism 12 becomes larger than the lower limit displacement V_min, the control device 100 maintains the clutch MGC in the on state in step S110. Further, in step S120, the control device 100 determines the capacitance control signal value Ic as the variable signal value Ic_cal. Then, at step S130, control device 100 operates compression mechanism 12 in the variable operation mode. That is, the control device 100 outputs the variable signal value Ic_cal to the capacitance control mechanism 40 as the capacitance control signal value Ic.

On the other hand, when the estimated displacement V of the compression mechanism 12 becomes equal to or less than the lower limit displacement V_min, the control device 100 proceeds to step S150 and maintains the clutch MGC in the on state. Further, in step S160, control device 100 determines capacitance control signal value Ic as lower limit signal value Ic_min. Then, in step S170, the control device 100 operates the compression mechanism 12 in the intermittent operation mode. That is, the control device 100 outputs the lower limit signal value Ic_min to the capacitance control mechanism 40 as the capacitance control signal value Ic.

The above is the description of the variable driving process. The intermittent operation process of the present embodiment is the same as the intermittent operation process described in the first embodiment. Therefore, the description of the intermittent operation process of the present embodiment is omitted.

In the compressor 10 according to the present embodiment, the displacement control mechanism 40 changes the discharge displacement according to the displacement control signal value Ic such that the flow amount Gr of the refrigerant discharged from the compression mechanism 12 becomes the target flow amount Gro. There is. Even when the discharge capacity is set to the lower limit capacity, the control device 100 according to the present embodiment satisfies the condition that the cooling capacity of air in the evaporator 80 satisfies the required cooling capacity required of the evaporator 80. Switch from the variable operation mode to the intermittent operation mode. The capability satisfying condition is a condition that is satisfied when the estimated displacement V obtained by estimating the discharge displacement of the compression mechanism 12 becomes equal to or less than the lower limit displacement V_min. According to this, since it is possible to prevent the cooling capacity of the air in the evaporator 80 from becoming excessive, it is possible to improve the compression efficiency while appropriately exhibiting the cooling capacity in the evaporator 80.

Sixth Embodiment
Next, a sixth embodiment will be described with reference to FIGS. 25 to 29. The present embodiment is different from the first embodiment in that a transition operation mode is provided as an operation mode of the compression mechanism 12. Of the drawings, FIG. 25 corresponds to FIG. 5 of the first embodiment, and FIG. 26 corresponds to FIG. 6 of the first embodiment. In FIG. 25 and FIG. 26, the same steps as those in FIG. 5 and FIG.

As shown in FIG. 25, the control device 100 determines in step S50A whether the current operation mode of the compression mechanism 12 is the variable operation mode, the intermittent operation mode, or the transition operation mode. As a result of the determination process, when the operation mode is the variable operation mode, the control device 100 proceeds to step S60 and executes the variable operation process. When the operation mode is the intermittent operation mode, the control device 100 proceeds to step S70 and executes the intermittent operation process. Furthermore, when the operation mode is the transition operation mode, the control device 100 proceeds to step S80 and executes transition operation processing.

First, the flow of the variable driving process will be described with reference to the flowchart of FIG. As shown in FIG. 26, the control device 100 determines in step S100A whether or not the outlet temperature TE of the evaporator 80 is smaller than the first determination threshold Tth1. The first determination threshold Tth1 is set to a temperature lower than the target evaporator temperature TEO, as shown in FIG.

When the blowout temperature TE of the evaporator 80 becomes equal to or higher than the first determination threshold Tth1, the control device 100 maintains the clutch MGC in the ON state in step S110, and changes the displacement control signal value Ic in step S120. Determine the value Ic_cal. Then, at step S130, control device 100 operates compression mechanism 12 in the variable operation mode.

On the other hand, when the blowout temperature TE of the evaporator 80 is smaller than the first determination threshold Tth1, the control device 100 shifts to step S150 to maintain the clutch MGC in the on state, and in step S160, the displacement control signal value Ic. Is determined as the lower limit signal value Ic_min. Then, in step S180, control device 100 operates compression mechanism 12 in the transition operation mode. That is, the control device 100 outputs the lower limit signal value Ic_min to the displacement control mechanism 40 as the displacement control signal value Ic while maintaining the clutch MGC in the on state.

Next, the flow of the transition operation process will be described with reference to the flowchart of FIG. The transition operation mode is an operation mode in which the lower limit signal value Ic_min is maintained as the displacement control signal value Ic while the clutch MGC is maintained in the on state.

As shown in FIG. 28, in step S500, the control device 100 determines whether the outlet temperature TE of the evaporator 80 is larger than the target evaporator temperature TEO. As a result, when the outlet temperature TE of the evaporator 80 is larger than the target evaporator temperature TEO, it is considered that the cooling capacity of the evaporator 80 is insufficient and the capacity is insufficient. Therefore, when the blowout temperature TE of the evaporator 80 becomes higher than the target evaporator temperature TEO, the control device 100 maintains the clutch MGC in the on state in step S510, and in step S520, the capacity control signal value Ic. Is determined as the variable signal value Ic_cal. Then, in step S530, control device 100 operates compression mechanism 12 in the variable operation mode.

On the other hand, when the blowout temperature TE of the evaporator 80 becomes equal to or lower than the target evaporator temperature TEO, the control device 100 determines that the blowout temperature TE of the evaporator 80 is lower than the second determination threshold Tth2 in step S540. It is determined whether the The second determination threshold Tth2 is set to a temperature lower than the first determination threshold Tth1, as shown in FIG.

If the temperature TE of the evaporator 80 is lower than the second determination threshold Tth2, it is considered that the cooling capacity of the evaporator 80 is in excess of the required cooling capacity required. Therefore, when the blowout temperature TE of the evaporator 80 becomes lower than the second determination threshold Tth2, the control device 100 switches the clutch MGC to the off state in step S550, and the capacity control signal value in step S560. Determine Ic as the lower limit signal value Ic_min. Then, in step S570, control device 100 operates compression mechanism 12 in the intermittent operation mode.

On the other hand, when the blowout temperature TE of the evaporator 80 becomes a temperature equal to or higher than the second determination threshold Tth2, the control device 100 maintains the clutch MGC in the on state in step S580, and in step S590, the displacement control signal value Ic. Is determined as the lower limit signal value Ic_min. Then, in step S600, control device 100 causes compression mechanism 12 to operate in the transition operation mode.

Next, the flow of the intermittent operation process will be described with reference to the flowchart of FIG. As shown in FIG. 29, the control device 100 determines in step S700 whether the clutch MGC is in the on state. As a result, when it is determined that the clutch MGC is in the on state, the control device 100 determines whether the outlet temperature TE of the evaporator 80 is higher than the target evaporator temperature TEO in step S710.

If the blowout temperature TE of the evaporator 80 becomes equal to or less than the target evaporator temperature TEO, the control device 100 determines whether the blowout temperature TE of the evaporator 80 is the first determination threshold Tth1 or more in step S720. .

As a result, when the blowout temperature TE of the evaporator 80 becomes lower than the first determination threshold Tth1, the control device 100 sets the clutch MGC to the OFF state in step S730. On the other hand, when the outlet temperature TE of the evaporator 80 becomes equal to or higher than the first determination threshold Tth1, the control device 100 maintains the clutch MGC in the on state in step S740. Then, in step S750, control device 100 determines that capacity control signal value Ic is lower limit signal value Ic_min, and in step S760, maintains the operation mode of compression mechanism 12 in the intermittent operation mode.

Further, when the blowout temperature TE of the evaporator 80 becomes larger than the target evaporator temperature TEO in the determination process of step S710, the control device 100 controls the blowout temperature TE and the target evaporator temperature TEO in step S770. The integrated value ΔΔE of the temperature difference ΔE with the above is calculated. In the intermittent operation mode, the integrated value 把握 ΔE is used to grasp an insufficient capacity state where the cooling capacity of the evaporator 80 is insufficient for the required cooling capacity.

Subsequently, in step S780, the control device 100 determines whether the outlet temperature TE of the evaporator 80 is equal to or higher than a fourth determination threshold Tth4. The fourth determination threshold Tth4 is set to a temperature higher than the target evaporator temperature TEO, as shown in FIG.

When the blowout temperature TE of the evaporator 80 is equal to or higher than the fourth determination threshold Tth4, it is considered that the capacity shortage state of the evaporator 80 can not be avoided even if the intermittent operation mode is continued. Therefore, control device 100 maintains clutch MGC in the on state in step S790, and determines the displacement control signal value as variable signal value Ic_cal in step S800. Then, in step S810, control device 100 switches the operation mode of compression mechanism 12 to the variable operation mode.

Further, when the blowout temperature TE of the evaporator 80 becomes lower than the fourth determination threshold Tth4 in the determination process of step S780, the control device 100 determines that the integration value ΔΔE is equal to or more than the preset integration threshold in step S820. It is determined whether the

If the integrated value ΔΔE is equal to or higher than the integration threshold, it is considered that the capacity shortage state of the evaporator 80 can not be avoided even if the intermittent operation mode is continued. Therefore, the control device 100 shifts to step S790 and switches the operation mode to the variable operation mode.

On the other hand, when the integrated value ΔΔE is smaller than the integration threshold, it is considered that the capacity shortage state of the evaporator 80 is not continuously generated while the intermittent operation mode is continued. Therefore, the control device 100 proceeds to step S740, and maintains the operation mode in the intermittent operation mode with the clutch MGC in the on state.

On the other hand, when it is determined in step S700 that the clutch MGC is in the off state, the control device 100 determines that the outlet temperature TE of the evaporator 80 is higher than the third determination threshold Tth3 in step S830. It is determined whether or not it is large. The third determination threshold Tth3 is set to a temperature higher than the target evaporator temperature TEO and lower than the fourth determination threshold Tth4, as shown in FIG.

As a result, when the outlet temperature TE of the evaporator 80 is higher than the third determination threshold Tth3, the control device 100 resets the integrated value ΔΔE in step S840, and switches the clutch MGC to the on state in step S850. On the other hand, when the outlet temperature TE of the evaporator 80 becomes equal to or lower than the third determination threshold Tth3, the control device 100 maintains the clutch MGC in the OFF state in step S860. Then, the control device 100 determines the capacity control signal value Ic to be the lower limit signal value Ic_min in step S870, and maintains the operation mode of the compression mechanism 12 in the intermittent operation mode in step S880.

In the compressor 10 of the present embodiment, the variable operation mode → the transition operation mode when the capacity satisfying condition that the cooling capacity of the air in the evaporator 80 satisfies the required cooling capacity is satisfied even if the discharge capacity is set to the lower limit capacity. → The operation mode switches in the order of the intermittent operation mode. As described above, by interposing the transition operation mode before switching from the variable operation mode to the intermittent operation mode, it is possible to suppress the frequent occurrence of switching from the variable operation mode to the intermittent operation mode.

Further, in the compressor 10 according to the present embodiment, even if the discharge capacity is set to the lower limit capacity, variable operation is possible from the intermittent operation mode when the capacity insufficient condition in which the cooling capacity of air in the evaporator 80 is insufficient for the required cooling capacity is satisfied. Switch to operation mode. The capacity shortage condition is a condition that is satisfied when the integrated value ΔΔE exceeds a predetermined integration threshold in a period in which the clutch MGC is in the on state. According to this, it is possible to suppress frequent switching from the intermittent operation mode to the variable operation mode.

(Other embodiments)
Having described exemplary embodiments of the present disclosure, the present disclosure is not limited to the above embodiments, for example, can be variously modified as follows.

Although the above-mentioned each embodiment demonstrated the example which the space in which the swash plate 24 in the housing 14 was accommodated becomes the control pressure chamber 18, it is not limited to this. As described in JP-A-2016-98679, the compression mechanism 12 controls a space defined by a moving body for changing the inclination angle of the swash plate 24, the rotation shaft 20, the lug plate 22 and the like. It may be configured to function as 18.

In each of the embodiments described above, the compression mechanism 12 is illustrated as having the single-headed piston 29, but is not limited thereto. The compression mechanism 12 may be configured to have, for example, a double-ended piston.

Although the above-mentioned each embodiment demonstrated the example which applies the compressor 10 of this indication with respect to the refrigerating-cycle apparatus 1 for air-conditioning a vehicle interior, it is not limited to this. The compressor 10 of the present disclosure can be widely applied to, for example, a refrigeration cycle apparatus for cooling the inside of a trailer of a trailer.

In the above embodiment, the elements constituting the embodiments, except such case where they are considered principally apparent that essential that clearly to be particularly essential, it is needless to say not necessarily indispensable.

In the above embodiment, when numerical values such as the number, numerical value, amount, range and the like of the constituent elements of the embodiment are mentioned, it is clearly indicated that they are particularly essential and clearly limited to a specific number in principle. It is not limited to that particular number except in cases such as, etc.

In the above embodiment, when referring to the shape, positional relationship, etc. of the component etc., unless otherwise specified or in principle when limited to a specific shape, positional relationship, etc., the shape, positional relationship, etc. but it is not limited to equal.

(Summary)
According to the first aspect of the present invention described in part or all of the above-described embodiments, the variable displacement compressor has a lower limit displacement of the discharge displacement greater than the minimum displacement and less than the maximum displacement relative to the compression mechanism. There is provided a capacity limiting unit for limiting to an intermediate capacity. The control device is configured to be able to switch the operation mode to the variable operation mode and the intermittent operation mode. However, the variable operation mode is an operation mode in which the displacement control mechanism changes the discharge displacement in the range from the lower limit displacement to the maximum displacement by controlling the clutch in the connected state. The intermittent operation mode is an operation mode in which the clutch is used to intermittently switch between the connected state and the disconnected state while the displacement control mechanism controls the discharge displacement to the lower limit displacement.

According to the second aspect, the variable displacement compressor has a capacity that is larger than that obtained when the compression mechanism is operated in the range from the minimum capacity to the maximum capacity and the lower limit capacity is set to the minimum capacity. It is set. According to this, it is possible to increase the coefficient of performance in the intermittent operation mode as compared with the case of operating with the minimum capacity.

According to the third aspect, the compression mechanism of the variable displacement compressor includes a suction chamber for introducing the refrigerant into a compression chamber for compressing the refrigerant, and a discharge chamber for extracting the refrigerant compressed in the compression chamber. And a housing provided with a control pressure chamber for changing the displacement. The compression mechanism is configured such that the discharge capacity increases as the pressure in the control pressure chamber decreases. The housing is formed with an air supply passage for introducing the refrigerant in the discharge chamber to the control pressure chamber, and a bleed passage for introducing the refrigerant in the control pressure chamber to the suction chamber. The capacity control mechanism is configured to reduce the circulation amount of the refrigerant circulating through the air supply passage, the control pressure chamber, and the bleed passage in the intermittent operation mode as compared with the variable operation mode. According to this, since the loss accompanying the circulation of the refrigerant inside the housing is suppressed in the intermittent operation mode, the compression efficiency can be further improved.

According to the fourth aspect, the capacity control mechanism of the variable displacement compressor is configured to open the air supply passage and close the bleed passage during the intermittent operation mode. According to this, since it is possible to stop the circulation of the refrigerant inside the housing at the time of the intermittent operation mode, it is possible to further improve the compression efficiency.

According to the fifth aspect, in the capacity control mechanism of the variable displacement compressor, the passage opening degree of the bleed passage decreases as the passage opening degree of the air supply passage increases, and the passage opening degree of the air supply passage decreases. The displacement control valve is configured such that the passage opening degree of the bleed passage increases. According to this, when the passage opening degree of the air supply passage is increased so that the pressure of the control pressure chamber is increased, the passage opening degree of the bleed passage is decreased, so that the discharge capacity can be reduced rapidly. Further, in the variable displacement compressor of the present disclosure, when the passage opening degree of the air supply passage is reduced so that the pressure in the control pressure chamber is decreased, the passage opening degree of the extraction passage is increased. can do.

In addition, in the variable displacement compressor according to the present disclosure, when the discharge capacity decreases, the passage opening degree of the bleed passage decreases, and the circulation amount of the refrigerant in the housing decreases, so compression efficiency can be improved. it can.

According to the sixth aspect, the displacement control mechanism of the variable displacement compressor controls the opening degree adjusting valve for adjusting the passage opening degree of the air supply passage, and extracts the bleed air as the pressure difference between the discharge chamber and the control pressure chamber decreases. It includes a pressure responsive valve that reduces the passage opening degree of the passage. Thus, the displacement control mechanism may be configured to include two valves. Also according to this configuration, when the discharge capacity decreases, the passage opening degree of the bleed passage decreases, and the circulation amount of the refrigerant in the housing decreases, so that the compression efficiency can be improved.

According to the seventh aspect, the controller of the variable displacement compressor is satisfied with the ability to cool air in the evaporator to satisfy the required cooling ability required of the evaporator even if the discharge capacity is set to the lower limit capacity. When the condition is satisfied, the variable operation mode is switched to the intermittent operation mode. According to this, since it is possible to prevent the cooling capacity of air in the evaporator from becoming excessive, it is possible to improve the compression efficiency while appropriately exhibiting the cooling capacity in the evaporator.

According to the eighth aspect, the control device of the variable displacement compressor calculates the displacement control signal value to be output to the displacement control mechanism so that the difference between the blowout temperature and the target evaporator temperature becomes smaller. The displacement control mechanism is configured to change the discharge displacement in accordance with the displacement control signal value so that the pressure of the refrigerant drawn into the compression mechanism becomes the target pressure. The capability satisfaction condition is a condition that is satisfied when the blowout temperature is lower than the target evaporator temperature and the displacement control signal value is less than or equal to a predetermined determination threshold. According to this, it is possible to avoid switching from the variable operation mode to the intermittent operation mode when the blowout temperature becomes equal to or higher than the target evaporator temperature, that is, in a state where the cooling capacity of the evaporator is insufficient.

According to the ninth aspect, in the variable displacement compressor, the determination threshold is a variable threshold that decreases as the target evaporator temperature increases. The displacement of the compressor may change depending on the heat load on the air side of the evaporator regardless of the value of the displacement control signal. For this reason, it is desirable that the determination threshold value to be compared with the capacity control signal value be a variable threshold value corresponding to the target evaporator temperature that changes in correlation with the heat load on the air side of the evaporator.

According to the tenth aspect, the control device of the variable displacement compressor calculates a displacement control signal value to be output to the displacement control mechanism so that the difference between the blowout temperature and the target evaporator temperature is reduced. The displacement control mechanism is configured to change the displacement according to the displacement control signal value so that the flow rate of the refrigerant discharged from the compression mechanism becomes the target flow rate. Then, the capability satisfaction condition is satisfied when the estimated displacement of the discharge displacement estimated based on the flow rate of the refrigerant discharged from the compression mechanism, the number of rotations of the compression mechanism, and the blowout temperature becomes smaller than the lower limit displacement. It has become. According to this, since it is possible to prevent the cooling capacity of air in the evaporator from becoming excessive, it is possible to improve the compression efficiency while appropriately exhibiting the cooling capacity in the evaporator.

According to the eleventh aspect, the controller of the variable displacement compressor is insufficient in the cooling capacity required for the air in the evaporator and the required cooling capacity required for the evaporator even if the discharge capacity is set to the lower limit capacity. When the condition is satisfied, the intermittent operation mode is switched to the variable operation mode. According to this, since it is possible to avoid the shortage of the cooling capacity of air in the evaporator, it is possible to improve the compression efficiency while properly exhibiting the cooling capacity in the evaporator.

According to the twelfth aspect, in the variable displacement compressor, the condition where the blowout temperature becomes higher than the target evaporator temperature is continued for a predetermined period while the insufficient capacity condition controls the connection state to the connection state by the clutch. It is a condition that holds in the case.

Here, it may be considered as a condition that is satisfied when the blowout temperature becomes higher than the target evaporator temperature in the state where the compression mechanism is connected to the engine as the insufficient capacity condition. However, in this case, frequent occurrence of switching from the intermittent operation mode to the variable operation mode is concerned when the blow-out temperature becomes near the target evaporator temperature.

On the other hand, if the condition of insufficient capacity is a condition that is satisfied when the condition where the outlet temperature is higher than the target evaporator temperature is maintained for a predetermined period, frequent switching from the intermittent operation mode to the variable operation mode is suppressed. be able to.

According to the thirteenth aspect, in the variable displacement compressor, the integrated capacity value of the difference between the outlet temperature and the target evaporator temperature integrated during the period in which the clutch is in the engaged state in the underperformance condition is The condition is satisfied when the predetermined integration threshold value is exceeded. As described above, if the insufficient capacity condition is a condition that is satisfied when the integrated value of the difference between the outlet temperature and the target evaporator temperature in the intermittent operation mode exceeds a predetermined integration threshold, the intermittent operation mode to the variable operation mode The frequency of switching to can be suppressed.

According to the fourteenth aspect, the control device of the variable displacement compressor is switchable to the transition operation mode in which the displacement control mechanism controls the discharge displacement to the lower limit displacement by the displacement control mechanism in a state in which the connection state is controlled to the connection state by the clutch. It is configured. And, even if the control device sets the discharge capacity to the lower limit capacity, the variable operation mode → transition when the capacity satisfying condition satisfying the required cooling capacity required of the evaporator for the air cooling capacity in the evaporator is satisfied. Switch the operation mode in the order of operation mode → intermittent operation mode. As described above, by interposing the transition operation mode before switching from the variable operation mode to the intermittent operation mode, it is possible to suppress the frequent occurrence of switching from the variable operation mode to the intermittent operation mode.

Claims

A variable capacity applicable to a refrigeration cycle apparatus (1) including an evaporator (80) including an evaporator (80) for cooling air blown into a space to be air conditioned by latent heat of evaporation of the refrigerant, and capable of changing the discharge capacity of the refrigerant in the range from the minimum capacity to the maximum capacity Type compressor, and
A compression mechanism (12) driven by the engine (EG) to compress and discharge the refrigerant;
A volume control mechanism (40) for controlling the discharge volume of the refrigerant discharged from the compression mechanism;
A clutch (MGC) that switches a connection state between the compression mechanism and the engine between a connection state in which the driving force of the engine is transmitted to the compression mechanism and a disconnection state in which the driving force of the engine is not transmitted to the compression mechanism;
And a control device (100) for switching the operation mode by controlling the displacement control mechanism and the clutch.
The compression mechanism is provided with a capacity limiting section (27) for limiting the lower limit capacity of the discharge capacity to an intermediate capacity which is larger than the minimum capacity and smaller than the maximum capacity.
The controller is
The discharge temperature of the air blown out from the evaporator by changing the discharge displacement in the range from the lower limit displacement to the maximum displacement by the displacement control mechanism while the connection state is controlled to the connection state by the clutch. Variable operation mode, which brings the temperature close to the target evaporator temperature,
The outlet temperature is switched to the target evaporator temperature by switching the connection state between the connection state and the disconnection state intermittently by the clutch in a state where the discharge capacity is controlled to the lower limit capacity by the capacity control mechanism. With intermittent operation mode,
Switchable variable displacement compressor.
The lower limit capacity is set to a capacity at which the coefficient of performance when the compression mechanism is operated in the range from the minimum capacity to the maximum capacity is larger than that when the minimum capacity is set. Variable displacement compressor.
The compression mechanism includes a suction chamber (32) for introducing a refrigerant into a compression chamber (28) for compressing a refrigerant, a discharge chamber (34) for discharging a refrigerant compressed in the compression chamber, the discharge It has a housing (14) provided with a control pressure chamber (18) for changing the capacity, and the discharge displacement becomes larger as the pressure in the control pressure chamber becomes smaller,
The housing is formed with an air supply passage (140) for introducing the refrigerant in the discharge chamber to the control pressure chamber, and a bleed passage (141) for introducing the refrigerant in the control pressure chamber to the suction chamber.
The capacity control mechanism is configured such that a circulation amount of the refrigerant circulating through the air supply passage, the control pressure chamber, and the bleed passage is smaller in the intermittent operation mode than in the variable operation mode. The variable displacement compressor according to claim 1 or 2.
The variable displacement compressor according to claim 3, wherein the capacity control mechanism is configured to open the air supply passage and close the bleed passage during the intermittent operation mode.
In the capacity control mechanism, the passage opening degree of the bleed passage decreases as the passage opening degree of the air supply passage increases, and the passage opening degree of the bleed passage increases as the passage opening degree of the air supply passage decreases. A variable displacement compressor according to claim 3 or 4, comprising a displacement control valve (45) configured to:
The displacement control mechanism adjusts the opening degree of the air supply passage, and the opening degree of the bleed passage as the pressure difference between the discharge chamber and the control pressure chamber decreases. The variable displacement compressor according to claim 3 or 4, comprising a pressure responsive valve (48) to be reduced.
Even if the control device sets the discharge capacity to the lower limit capacity, the variable condition is satisfied if a capacity satisfying condition for satisfying the required cooling capacity required for the evaporator is satisfied. The variable displacement compressor according to any one of claims 1 to 6, wherein the operation mode is switched to the intermittent operation mode.
The control device calculates a capacity control signal value to be output to the capacity control mechanism such that a difference between the blowout temperature and the target evaporator temperature is reduced.
The displacement control mechanism is configured to change the discharge displacement in accordance with the displacement control signal value so that the pressure of the refrigerant drawn into the compression mechanism becomes a predetermined target pressure.
The variable capacity type according to claim 7, wherein the capability satisfaction condition is a condition that is satisfied when the blowout temperature is lower than the target evaporator temperature and the capacity control signal value becomes equal to or less than a predetermined determination threshold. Compressor.
The variable displacement compressor according to claim 8, wherein the determination threshold is a variable threshold that decreases with an increase in the target evaporator temperature.
The control device calculates a capacity control signal value to be output to the capacity control mechanism such that a difference between the blowout temperature and the target evaporator temperature is reduced.
The capacity control mechanism is configured to change the discharge capacity in accordance with the capacity control signal value such that the flow rate of the refrigerant discharged from the compression mechanism becomes a predetermined target flow rate.
The capacity satisfying condition is that the estimated displacement of the discharge capacity estimated based on the flow rate of the refrigerant discharged from the compression mechanism, the number of rotations of the compression mechanism, and the blowout temperature is smaller than the lower limit capacity. The variable displacement compressor according to claim 7, which is a condition that holds true.
Even when the control device sets the discharge capacity to the lower limit capacity, the intermittent operation is performed when a capacity shortage condition in which the cooling capacity of air in the evaporator is insufficient for the required cooling capacity required for the evaporator is established. The variable displacement compressor according to any one of claims 1 to 10, wherein the operation mode is switched to the variable operation mode.
The insufficient capacity condition is a condition that is satisfied when a state in which the blowout temperature is higher than the target evaporator temperature is continued for a predetermined period while the connection state is controlled to the connection state by the clutch. The variable displacement compressor according to 11.
The insufficient capacity condition is that the integrated value of the difference between the blowout temperature and the target evaporator temperature integrated in the period in which the clutch is in the connected state in the intermittent operation mode exceeds a predetermined integration threshold. The variable displacement compressor according to claim 11, which is a condition that holds true.
The controller is
In a state where the connection state is controlled to the connection state by the clutch, the displacement control mode is configured to be switchable to a transition operation mode in which the discharge displacement is controlled to the lower limit displacement.
Even if the discharge capacity is set to the lower limit capacity, the variable operation mode → the transition when the capacity satisfying condition satisfying the required cooling capacity required for the evaporator is satisfied. The variable displacement compressor according to any one of claims 1 to 6, wherein the operation mode is switched in the order of an operation mode → the intermittent operation mode.