JP5062160B2 - Refrigeration cycle and compressor - Google Patents

Description

  The present invention relates to a refrigeration cycle or a compressor that can be used in the refrigeration cycle.

  Conventionally, in a refrigeration cycle used for an air conditioner or the like, it is known to use a compressor capable of changing a discharge capacity in order to increase or decrease the cooling capacity. In a swash plate type variable displacement compressor, which is a type of compressor capable of changing the discharge capacity, a part of the compressed refrigerant is introduced into the crank chamber to control the discharge capacity, and the pressure in the crank chamber is reduced. Increasing or decreasing the inclination of the swash plate changes the discharge capacity (for example, Patent Document 1).

However, since the swash plate type variable capacity compressor introduces a part of the compressed refrigerant into the crank chamber and then returns to the suction chamber, the discharge chamber and the suction chamber are in a bypass state via the crank chamber and the efficiency is increased. Is worsening.
JP-A-54-94107

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a refrigeration cycle and a compressor capable of improving the efficiency of a variable capacity compressor.

  In achieving the above object, the invention according to claim 1 is directed to a condenser (7) for cooling the compressed refrigerant, and a first expansion valve for expanding the refrigerant cooled by the condenser (7). (9), a gas-liquid separator (8) that performs gas-liquid separation of the refrigerant that has passed through the first expansion valve (9), and a liquid-phase refrigerant separated by the gas-liquid separator (8). A second expansion valve (10) to be expanded; an evaporator (12) that receives the refrigerant expanded by the second expansion valve (10), receives heat from outside, and evaporates the refrigerant by latent heat of evaporation; The gas-phase refrigerant that has passed through the evaporator (12) is sucked and compressed with a capacity determined in accordance with the pressure of the crank chamber (940) provided inside, and is discharged to the condenser (7). The gas phase refrigerant in the compressor (4) and the gas-liquid separator (8) is transferred to the compressor crank chamber (940). A pipe (13) leads, wherein the and a pipe (13) by the discharge capacity control means for controlling the pressure of the refrigerant is guided to the crank chamber (940) (15).

  Thereby, compared with the case where the pressure of a crank chamber (940) is controlled only by the discharge refrigerant | coolant of a compressor (4) like the past, compression efficiency can be improved.

  According to a second aspect of the present invention, in the first aspect of the present invention, the target discharge capacity determining means for determining a target discharge capacity of the compressor (4) and the first expansion valve (9) are passed. Expansion pressure upstream pressure measuring means for measuring the previous refrigerant pressure, and the discharge capacity control means (15) measures the target discharge capacity determined by the target discharge capacity determination means and the expansion valve upstream pressure measurement. The opening degree of the first expansion valve (9) and the second expansion valve (10) is adjusted based on the refrigerant pressure measured by the means, and the pressure in the crank chamber (940) is adjusted to the compressor ( The discharge capacity of 4) is adjusted to a pressure that becomes the target discharge capacity.

  Thereby, the motive power of a compressor (4) can be reduced compared with the conventional capacity | capacitance control system.

  According to a third aspect of the present invention, in the first aspect of the present invention, a target discharge capacity determining means for determining a target discharge capacity of the compressor (4) and a gas pressure for measuring a refrigerant pressure in the gas-liquid separator. Liquid discharger internal pressure measurement means, the discharge capacity control means (15) has a control valve (14) provided in the pipe (13), the control valve (14) is the target Based on the target discharge capacity determined by the discharge capacity determining means and the refrigerant pressure measured by the gas-liquid separator internal pressure measuring means, the pressure of the crank chamber (940) is determined by the discharge capacity of the compressor (4). The pressure is adjusted to the target discharge capacity.

  Thereby, the motive power of a compressor (4) can be reduced compared with the conventional capacity | capacitance control system.

  According to a fourth aspect of the present invention, in the third aspect of the present invention, the discharge capacity control means (15) is configured such that the first expansion valve (9) is a refrigerant in the gas-liquid separator (8). The pressure is controlled to be higher than the pressure in the crank chamber (940) that realizes the target discharge capacity.

  Thereby, the pressure of the crank chamber (940) can be adjusted to a pressure at which the discharge capacity of the compressor (4) becomes the target discharge capacity only by adjusting the opening of the control valve (14).

  The invention according to claim 5 is the invention according to claim 3 or 4, further comprising operating state switching means for switching the operating state of the refrigeration cycle, wherein the operating state switching means is the discharge capacity control means. (15) The normal operation state in which the discharge capacity of the compressor (4) is controlled, the control valve (14) is closed, the refrigerant is expanded by the first expansion valve (9), and the evaporator ( The first expansion mode operation state to be introduced into 12) is switched.

  Thereby, the operating state of the refrigeration cycle can be switched according to the situation.

  The invention according to claim 6 is the invention according to claim 3, further comprising an operation state switching means for switching an operation state of the refrigeration cycle, wherein the operation state switching means is controlled by the discharge capacity control means (15). The normal operating state for controlling the discharge capacity of the compressor (4), the control valve (14) is closed, the first expansion valve (9) is released, and the refrigerant that has passed through the condenser (7) is removed. The second expansion valve (10) is expanded and switched to the second expansion mode operating state to be introduced into the evaporator (12).

  Thereby, the operating state of the refrigeration cycle can be switched according to the situation.

  The invention according to claim 7 is the invention according to claim 3, further comprising operating state switching means for switching the operating state of the refrigeration cycle, wherein the operating state switching means is controlled by the discharge capacity control means (15). The normal operation state for controlling the discharge capacity of the compressor (4), the control valve (14) are closed, and the first expansion valve (9) and the second expansion valve (10) are used to supply the refrigerant. The third expansion mode operation state is expanded and switched to the evaporator (12) to be switched.

  Thereby, the operating state of the refrigeration cycle can be switched according to the situation.

  The invention according to claim 8 is the invention according to claim 1, further comprising operating state switching means for switching the operating state of the refrigeration cycle, wherein the discharge capacity control means (15) is connected to the pipe (13). A three-way valve (710) that is provided and guides the refrigerant flowing through the pipe (13) to the compressor cylinder chamber (910) or the crank chamber (940); By controlling (710), the discharge capacity control means (15) controls the discharge capacity of the compressor (4), and the gas phase separated by the gas-liquid separator (8). The two-stage compression mode state in which the refrigerant is introduced into the cylinder chamber (910) during the compression process is switched.

  Thereby, the operating state of the refrigeration cycle can be switched according to the situation.

  The invention according to claim 9 is the invention according to claim 1, further comprising operating state switching means for switching the operating state of the refrigeration cycle, wherein the discharge capacity control means (15) is connected to the pipe (13). A three-way valve (810) that is provided and guides the refrigerant flowing through the pipe (13) to the compressor suction port or the crank chamber (940), and the operation state switching means includes the three-way valve (810) By controlling the discharge capacity of the compressor (4) by the discharge capacity control means (15), and the gas-phase refrigerant separated by the gas-liquid separator (8) is compressed. The refrigerant is introduced into the machine inlet, and the state is switched between the refrigerant cooling mode state in which the liquid refrigerant is introduced into the evaporator (12).

  Thereby, the efficiency improvement effect by reduction of an evaporator pressure loss can be acquired by switching the operation state of a refrigerating cycle according to a condition.

  In addition, the code | symbol in the parenthesis attached | subjected to each said means is an example which shows a corresponding relationship with the specific means as described in embodiment mentioned later.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1, 2, 3, and 4 to 6. In the present embodiment, the refrigeration cycle and the compressor of the present invention are applied to a vehicle air conditioner.
(Configuration of this embodiment)
FIG. 1 is a diagram showing a configuration of a vehicle air conditioner in the present embodiment.

  The engine 1 is a traveling drive source mounted on the vehicle. A drive pulley 2 is provided on the output shaft of the engine 1. The drive pulley 2 rotates in conjunction with the drive of the engine 1. The compressor 4 is a component part of the refrigeration cycle 6 of the vehicle. A passive pulley 3 is provided on the drive shaft of the compressor 4. A belt 5 that is a power transmission member is wound around the drive pulley 2 and the passive pulley 3. Thereby, the compressor 4 is driven by the engine 1.

  Next, the compressor 4 in this embodiment is demonstrated using FIG. FIG. 4 is a sectional view of the compressor 4.

  The compressor 4 includes a housing 901 serving as an outer shell. The housing 901 includes a front housing 901a, a middle housing 901b, and a rear housing 901c. The front housing 901a includes a boss portion 901d through which one end of the shaft 920 passes. The boss portion 901d has a cylindrical shape, and a seal member 901e that seals between the shaft 920 and the front housing 901a is disposed therein. Further, a space serving as a crank chamber 940 described later is formed inside the front housing 901a. A control port 970 connected to the space serving as the crank chamber 940 is opened on the side surface of the front housing 901a. Further, a front bearing 901f that supports the shaft 920 is provided between the space serving as the crank chamber 940 and the inside of the boss 901d.

  The middle housing 901b is fastened to the front housing 901 by fastening means such as bolts via sealing means such as a gasket. The middle housing 901b includes a rear bearing 901g that supports the rear end of the shaft 920 at the center. In the middle housing 901b, a plurality of cylindrical cylinder chambers 910 are formed around the rear side bearing 901g.

  The rear housing 901c is fastened to the middle housing 901b by a fastening means such as a bolt via a gasket or a valve plate. A suction chamber 960 described later is provided in the center of the rear housing 901c. A discharge chamber 950, which will be described later, is formed around the suction chamber 960.

  The suction chamber 960 is a space for sucking the refrigerant to be compressed through a suction port (not shown). The cylinder chamber 910 is a space for compressing the refrigerant guided from the suction chamber 960 together with a piston 911 described later. Further, the discharge chamber 950 is a space into which the refrigerant compressed by the piston 911 and the cylinder chamber 910 is introduced and sent out through a discharge port (not shown).

  The passive pulley 3 shown in FIG. 1 is connected to the shaft 920. A swash plate 930 is attached to the lug plate 920b attached to the shaft 920 via a link mechanism so that the inclination angle of the shaft 920 can be varied. A CS passage (not shown) is provided in the shaft 920. The CS passage inlet 921 and the CS passage outlet 922 provided on the side surface of the shaft 920 are the inlet and outlet of the CS passage.

  A piston 911 is attached to the swash plate 930 via a shoe. The piston 911 is slidably inserted into the cylinder chamber 910.

  Hereinafter, the operation of the compressor 4 will be described. When the shaft 920 is rotated by the engine 1, the swash plate 930 rotates with the shaft 920. At this time, the crank chamber 940 is filled with the refrigerant introduced through the control port 970, and the inclination of the swash plate 930 is caused by the difference between the pressure in the crank chamber 940 and the pressure of the suction refrigerant introduced into the cylinder chamber 911. The corner is determined. The piston 911 reciprocates in the cylinder chamber 910 by the inclination and rotation of the swash plate 930. At this time, the stroke amount of the reciprocating motion of the piston 911 varies depending on the inclination angle of the swash plate 930. That is, by changing the pressure in the crank chamber 940, the discharge capacity of the compressor 4 changes.

  Further, in the compressor 4 in the present embodiment, the refrigerant is introduced through the control port 970 when the pressure in the crank chamber 940 is increased. When the pressure in the crank chamber 940 is reduced, the introduction of the refrigerant from the control port 970 is stopped. At this time, the refrigerant in the crank chamber 940 is guided to the suction chamber through a CS passage (not shown).

  Next, the configuration of the refrigeration cycle 6 will be described with reference to FIG. The refrigeration cycle 6 includes a compressor 4, a condenser 7, a first expansion valve 9, a gas-liquid separator 8, a second expansion valve 10, and an evaporator 12.

  The condenser 7 is a heat exchanger that condenses and liquefies the high-temperature and high-pressure refrigerant compressed by the compressor 4. The first expansion valve 9 is an electromagnetic valve that decompresses and expands the refrigerant flowing out of the condenser 7. The gas-liquid separator 8 is a container for gas-liquid separation of the gas-liquid two-phase refrigerant decompressed and expanded by the first expansion valve 9. The second expansion valve 10 is an electromagnetic valve that decompresses and expands the liquid refrigerant separated by the gas-liquid separator 8. The evaporator 12 is a heat exchanger that receives the refrigerant expanded by the second expansion valve 10, receives heat from the outside, and evaporates the refrigerant by latent heat of evaporation.

  The refrigeration cycle 6 in the present embodiment has a pipe 13 for guiding the gas-phase refrigerant in the gas-liquid separator 8 to the crank chamber 940 through the control port 970 of the compressor 4 in addition to the above configuration, and the pipe 13 Discharge capacity control means 15 for controlling the pressure of the refrigerant guided to the chamber 940 is provided.

  The discharge capacity control means in the present embodiment includes a control valve 14 provided in the pipe 13, a temperature sensor 11, an air conditioner ECU 31, and the like. The control valve 14 is an electromagnetic valve that controls the pressure of the gas-phase refrigerant carried by the pipe 13 before introducing it into the crank chamber 940. The temperature sensor 11 is a temperature detection unit that is attached to the outlet side pipe of the condenser 7 and measures the temperature inside the outlet side pipe. The air conditioner ECU 31 is an electronic arithmetic unit that determines a target discharge capacity based on information from sensors 32 to 35 described later. The air conditioner ECU 31 estimates the pressure of the gas-phase refrigerant separated by the gas-liquid separator 8 from the refrigerant temperature measured by the temperature sensor 11 and the opening of the first expansion valve 9. It also has a function as an internal pressure measuring means. The air conditioner ECU 31 controls the pressure in the crank chamber 940 by adjusting the opening of the control valve 14 so that the discharge capacity of the compressor 4 becomes the target discharge capacity. The air conditioner ECU 31 controls the first expansion valve 9 so that the refrigerant pressure in the gas-liquid separator 8 is always higher than the pressure in the crank chamber 940 that achieves the target discharge capacity.

  Next, the air conditioning unit 21 will be described. The air conditioning unit 21 is a device that regulates the temperature of the wind generated by the air conditioning fan 23 and supplies it to the passenger compartment. The air conditioning unit 21 has an air conditioning case 22 constituting an outer shell. In the air conditioning case 22, the above-described evaporator 12, heater core 24, air mix door 25 and the like are installed. The heater core 24 is a heating heat exchanger in which engine cooling water for cooling the engine 1 flows. The wind that has passed through the heater core 24 is heated by exchanging heat with the engine coolant. The air mix door 25 is a temperature adjusting unit that changes a mixing ratio of the cool air cooled by passing through the evaporator 12 and the warm air heated by passing through the heater core 24. On the downstream side of the air conditioning case 22, there are provided a plurality of air outlets (not shown) for blowing the air mixed with the cool and warm air by the air mix door 25 toward the inner surface of the window glass in the passenger compartment and the upper and lower occupants. Yes.

  Next, changes on the Mollier diagram of the refrigeration cycle 6 will be described with reference to FIG.

  FIG. 2 is a Mollier diagram showing the refrigeration cycle 6 in the present embodiment. Between the point A3 and the point B3, the condenser 7 cools and condenses the refrigerant by exchanging heat with the outside air, and enters a low-temperature and high-pressure liquid phase state. Between the point B3 and the point C3, the refrigerant is depressurized by the first expansion valve 9 to be in a gas-liquid two-phase state. At point C3, the gas-liquid separator 8 separates the refrigerant into a gas-phase refrigerant and a liquid-phase refrigerant, the liquid-phase refrigerant is introduced into point D3, and the gas-phase refrigerant is introduced into the pipe 13 shown in FIG. Between the point D3 and the point E3, the refrigerant is depressurized by the second expansion valve 10 to be in a gas-liquid two-phase state. Between the point E3 and the point F3, the evaporator 12 absorbs heat by exchanging heat with the wind sent by the above-described air-conditioning fan 23 by the evaporator 12, and evaporates to become a gas-phase refrigerant. Between the point F3 and the point A3, the refrigerant is compressed by the compressor 4 to be in a high temperature and high pressure state.

  Next, the structure of the control part of the vehicle air conditioner in this embodiment is demonstrated. The air conditioner ECU 31 illustrated in FIG. 1 includes a CPU, a ROM, a RAM, and the like. In addition to the signal from the temperature sensor 11 described above, the air conditioner ECU 31 detects an inside air temperature sensor 32 that detects the temperature inside the vehicle, an outside air temperature sensor 33 that detects the outside air temperature, and the amount of solar radiation irradiated to the inside of the vehicle. Indication of activation of the solar radiation sensor 34, an after-evaporator temperature sensor 35 that detects an after-evaporator temperature that is the air temperature immediately after passing through the evaporator 12, a temperature setter 36 that sets a target temperature in the passenger compartment, and the compressor 4 A signal is input from the air conditioner switch 37 or the like.

  The air conditioner ECU 31 performs predetermined arithmetic processing based on the input signals. After the arithmetic processing, the discharge capacity control means in the air conditioner ECU 31 controls the refrigerant pressure in the crank chamber 940 of the compressor 4 by using the first expansion valve 9, the second expansion valve 10, and the control valve 14, and compresses them. The discharge capacity of the machine 4 is changed.

  Next, a control routine performed by the air conditioner ECU 31 will be described with reference to FIGS. FIG. 5 is a flowchart showing a control routine executed by the air conditioner ECU 31. In this routine, when the air conditioner switch is turned on and the air conditioner system is activated, signals from the sensors 32 to 35 and the temperature setting unit 36 are input in step S10.

  Next, in step S20, based on the signals from the inside air temperature sensor 32, the outside air temperature sensor 33, the solar radiation sensor 34, and the temperature setting device 36, the target blowing temperature TAO of the blowing air into the passenger compartment is calculated based on the following Equation 1. To calculate.

[Equation 1]
TAO = Kset × Tset-Kr × Tr-Kam × Tam-Ks × Ts-C (° C.)
Here, Kset, Kr, Kam, and Ks are coefficients of each signal value, Tset, Tr, Tam, and Ts are target temperature, vehicle interior temperature, outside air temperature, solar radiation intensity signal, and C is a control constant. Therefore, the target blowout temperature TAO is obtained by adding disturbances such as the outside air temperature Tam and the solar radiation amount Ts to the deviation between the target temperature Tset set by the temperature setting device 36 and the vehicle interior temperature Tr detected by the inside air temperature sensor 32. It can be said that the target temperature is calculated.

  Further, the target outlet temperature TAO is a temperature that is calculated to be lower as the vehicle interior temperature Tr detected by the internal air temperature sensor 32 is higher than the target temperature Tset set by the temperature setter 36. Therefore, it can be said that the lower the target blowing temperature TAO, the higher the vehicle interior cooling load.

  Then, based on the target outlet temperature TAO calculated in step S20 and the map shown in FIG. 6, a target air temperature TEO that is a target value of the temperature after passing through the evaporator is calculated. Here, the map of FIG. 6 is set so that the target air temperature TEO becomes lower as the target blowing temperature TAO is lower, that is, as the vehicle interior cooling load is higher.

  The air conditioner ECU 31 has a TEO-target discharge capacity map and a target discharge capacity-target crank chamber pressure map that are obtained in advance through experiments or the like and that correspond to the characteristics of the compressor. After TEO is determined, the air conditioner ECU 31 refers to the TEO-target discharge capacity map, and the target discharge capacity is determined in step S30 by the target discharge capacity determining means included in the air conditioner ECU 31. Thereafter, in step S40, the target crank chamber pressure is determined by referring to the target discharge capacity-target crank chamber pressure map based on the determined target discharge capacity. This is the target refrigerant pressure in the crank chamber 940 of the compressor 4 described above. The discharge capacity control means in the air conditioner ECU 31 controls the first expansion valve 9, the second expansion valve 10, and the control valve 14 so that the refrigerant pressure in the crank chamber 940 of the compressor 4 approaches the target crank chamber pressure. At least one of the openings is adjusted.

  Next, the operation mode of the vehicle air conditioner in this embodiment will be described. The present embodiment is characterized by having an operation state switching means that has two operation modes and switches the operation mode in accordance with the vehicle interior cooling load. After calculating the target crankcase pressure in step S40 in the flowchart of FIG. 5, the air conditioner ECU 31 switches between the variable capacity operation mode and the maximum discharge capacity operation mode according to the calculated target crankcase pressure.

  In the variable capacity operation mode of the vehicle air conditioner in the present embodiment, the opening degrees of the first expansion valve 9, the second expansion valve 10, and the control valve 14 are adjusted by the discharge capacity control means in the air conditioner ECU 31, and compressed. The discharge capacity of the machine 4 is controlled.

  On the other hand, in the maximum discharge capacity operation mode, the control valve 14 is closed, the second expansion valve 10 is opened, and expansion is performed by the first expansion valve 9 (hereinafter referred to as a first expansion mode operation state). By closing the control valve 14, the supply of the refrigerant to the crank chamber 940 of the compressor 4 is shut off. At this time, the refrigerant existing in the crank chamber 940 flows out to the suction chamber 960 through a CS passage (not shown). Therefore, the internal pressure of the crank chamber 940 decreases, and the discharge capacity of the compressor 4 becomes the maximum discharge capacity (approximately 100%).

  The refrigeration cycle in the first expansion mode operating state will be described with reference to FIG. FIG. 3 is a Mollier diagram in the refrigeration cycle in the first expansion mode operating state. Between the point A4 and the point B4, the temperature of the refrigerant is lowered by exchanging heat with the outside air by the condenser 7, and the liquid phase is in a low temperature and high pressure state. Between the point B4 and the point C4, the refrigerant is depressurized by the first expansion valve 9 to be in a gas-liquid two-phase state. At point C4, the gas-liquid separator 8 separates the gas-phase refrigerant and the liquid-phase refrigerant. Between the point E4 and the point D4, the evaporator 12 absorbs heat by exchanging heat with the wind sent by the above-described air-conditioning fan 23 by the evaporator 12 and evaporates. It becomes a gas phase refrigerant. Between the point D4 and the point A4, the refrigerant is compressed by the compressor 4 to be in a high temperature and high pressure state.

Note that the gas-liquid separation efficiency at the point C4 varies depending on the amount of cooling load in the vehicle interior, such as the amount of refrigerant sealed in the refrigeration cycle 6 and the flow rate of refrigerant circulating in the refrigeration cycle 6.
(Effect of this embodiment)
As described above, in the present embodiment, in the variable capacity operation mode, the pressure in the crank chamber 940 is controlled using only the gas-phase refrigerant of the gas-liquid separator 8. The refrigerant bypassed to the suction chamber via the crank chamber can be eliminated, and as a result, the compression efficiency can be improved.

  The first expansion valve 9 is controlled by the air conditioner ECU 31 so that the refrigerant pressure in the gas-liquid separator 8 is always higher than the pressure in the crank chamber 940 that achieves the target discharge capacity. The pressure in the crank chamber 940 can be adjusted to a pressure at which the discharge capacity of the compressor 4 becomes the target discharge capacity only by adjusting the opening of the valve 14.

  In addition, since the two modes can be used properly, the operating state of the refrigeration cycle can be switched according to the magnitude of the cooling load in the passenger compartment.

Further, in the present embodiment, in the first expansion mode operation state in which the discharge capacity of the compressor 4 is the maximum discharge capacity, the refrigerant containing a large amount of the liquid phase refrigerant that has been liquid phase refrigerant by the gas-liquid separator 8 is supplied to the evaporator 12. Since it is supplied, the cooling capacity of the refrigeration cycle 6 can be further improved.
(Second Embodiment)
Next, features of the second embodiment of the present invention will be described with reference to FIGS.

  In the said 1st Embodiment, the opening degree of the 1st expansion valve 9, the 2nd expansion valve 10, and the control valve 14 of a vehicle air conditioner is adjusted with the discharge capacity control means in air-conditioner ECU31, and the compressor 4 The variable displacement operation mode for controlling the discharge capacity of the first expansion mode and the first expansion mode operating state in which the control valve 14 is closed, the second expansion valve 10 is opened, and the first expansion valve 9 performs expansion are switched. However, this embodiment adopts the second expansion mode operation state in which the control valve 14 is closed, the first expansion valve 9 is opened, and the second expansion valve 10 performs expansion instead of the first expansion mode operation state. It is characterized by doing.

  The 2nd expansion mode operation state in this embodiment is demonstrated using FIG. FIG. 7 is a Mollier diagram showing the second expansion mode operating state. Between the point A5 and the point B5, the temperature of the refrigerant is lowered by exchanging heat with the outside air by the condenser 7, and a low-temperature and high-pressure liquid phase state is obtained. Between the point B5 and the point C5, the refrigerant is decompressed by the second expansion valve 10 to be in a gas-liquid two-phase state. Between the point C5 and the point D5, the evaporator 12 absorbs heat by exchanging heat with the wind sent by the air-conditioning fan 23, and evaporates to become a gas-phase refrigerant. Between the point D5 and the point A5, the refrigerant is compressed by the compressor 4 to be in a high temperature and high pressure state.

  In addition, even if the condensation of the refrigerant in the condenser 7 is incomplete, the gas-liquid separator 8 can be operated as a receiver in the refrigeration cycle, so that the liquid phase refrigerant is supplied to the second expansion valve 10. Can do.

In addition, since the two modes can be used properly, the operating state of the refrigeration cycle can be switched according to the magnitude of the cooling load in the passenger compartment.
(Third embodiment)
Next, features of the third embodiment of the present invention will be described with reference to FIGS.

  In the first embodiment, the opening degree of the first expansion valve 9, the second expansion valve 10, and the control valve 14 of the vehicle air conditioner is adjusted by the discharge capacity control means in the air conditioner ECU 31, and the compressor 4 The variable capacity operation mode for controlling the discharge capacity and the first expansion mode operating state in which the control valve 14 is closed, the second expansion valve 10 is opened, and the first expansion valve 9 performs expansion are switched. In this embodiment, instead of the first expansion mode operation state, the third expansion mode operation state is adopted in which the control valve 14 is closed and expansion is performed using both the first expansion valve 9 and the second expansion valve. It is characterized by that.

  The third expansion mode operating state in the present embodiment will be described with reference to FIG. FIG. 8 is a Mollier diagram showing a third expansion mode operating state in the present embodiment. Between the point A2 and the point B2, the temperature of the refrigerant is lowered by exchanging heat with the outside air by the condenser 7, and the liquid phase is in a low temperature and high pressure state. The refrigerant is decompressed by the first expansion valve 9 between the point B2 and the point C2. At point C2, the gas-liquid separator 8 separates the refrigerant into a gas phase and a liquid phase. However, since the pipe that flows out only the gas phase is closed, the refrigerant passes again in the gas-liquid two-phase state. Between the point D2 and the point E2, the refrigerant is depressurized by the second expansion valve 10 to be in a gas-liquid two-phase state. Between the point E2 and the point F2, the evaporator 12 absorbs heat by exchanging heat with the wind sent by the above-described air-conditioning fan 23, and evaporates to become a gas-phase refrigerant. Between the point F2 and the point A2, the refrigerant is compressed by the compressor 4 to be in a high temperature and high pressure state.

  Thereby, it can be operated as a two-stage expansion refrigeration cycle in the third expansion mode operating state.

In addition, since the two modes can be used properly, the operating state of the refrigeration cycle can be switched according to the compensation for the cooling load in the passenger compartment.
(Fourth embodiment)
Next, features of the fourth embodiment of the present invention will be described with reference to FIGS. 9, 8, and 4. FIG.

  In the first to third embodiments, the control valve 14 is used in at least one of the variable capacity operation mode and the maximum discharge capacity operation mode. However, in this embodiment, the variable capacity operation mode operation is performed without using the control valve. It is characterized by. In this embodiment, the maximum discharge capacity operation mode is not provided.

  The operation of the refrigeration cycle in this embodiment will be described with reference to FIGS. In addition, description is abbreviate | omitted about the part similar to 1st, 2nd embodiment. In the present embodiment, when the refrigerant pressure in the crank chamber 940 of the compressor 4 shown in FIG. 4 is controlled, the opening degrees of the first expansion valve 9 and the second expansion valve 10 shown in FIG. This is done by adjusting the discharge capacity control means. Thereby, the control valve in 1st thru | or 3rd embodiment can be eliminated from a refrigerating cycle.

  In the present embodiment, an expansion valve upstream pressure measuring means for measuring the refrigerant pressure before passing through the first expansion valve 9 is provided. The expansion valve upstream pressure measuring means in the present embodiment calculates the refrigerant pressure upstream of the first expansion valve 9 by the air conditioner ECU 31 from the information from the temperature sensor 11 that measures the temperature of the refrigerant that has passed through the condenser 7. Calculated.

  The Mollier diagram showing the movement of the variable capacity operation mode state in the refrigeration cycle in FIG. 9 has the same form as the Mollier diagram in the third expansion mode operating state in the third embodiment described with reference to FIG. Between the point A2 and the point B2, the temperature of the refrigerant is lowered by exchanging heat with the outside air by the condenser 7, and the liquid phase is in a low temperature and high pressure state. The refrigerant is decompressed by the first expansion valve 9 between the point B2 and the point C2. Between the first expansion valve 9 and the second expansion valve 10, the gas-liquid separator 8 separates the refrigerant into a gas phase and a liquid phase, the liquid phase refrigerant goes to point D2, and the gas phase refrigerant is shown in FIG. To the pipe 13 shown in FIG. Between the point D2 and the point E2, the refrigerant is decompressed by the second expansion valve 10. Between the point E2 and the point F2, the evaporator 12 absorbs heat by exchanging heat with the wind sent by the above-described air-conditioning fan 23, and evaporates to become a gas-phase refrigerant. Between the point F2 and the point A2, the refrigerant is compressed by the compressor 4 to be in a high temperature and high pressure state.

Thereby, variable displacement operation can be performed without using the control valve 14 in the first to third embodiments.
(Fifth embodiment)
Next, features of the fifth embodiment of the present invention will be described with reference to FIGS. In addition, the same code | symbol was attached | subjected to the site | part similar to 1st thru | or 4th embodiment.

  In the first to third embodiments, the control valve 14 is used in each operation mode. However, in this embodiment, the three-way valve 710 and the pipe 720 leading from the three-way valve 710 to the cylinder chamber 910 of the compressor 4 are the same. A piping 730 that leads from the three-way valve 710 to the crank chamber 940 of the compressor 4 is used. In this embodiment, in addition to the variable capacity operation mode or the first to third expansion modes in the first to third embodiments, a high efficiency operation mode is provided, and each operation mode is switched by the operation state switching means.

  First, the variable capacity operation mode of the vehicle air conditioner in the present embodiment will be described with reference to FIG. In the variable capacity operation mode of the vehicle air conditioner in this embodiment, the gas-phase refrigerant in the gas-liquid separator 8 is introduced into the pipe 730 to the crank chamber 940 through the pipe 13 by the three-way valve 710. Thereafter, the pipe 730 leads to the crank chamber 940 through the control port 970 of the compressor 4. Then, the discharge capacity of the compressor 4 is varied by the refrigerant introduced into the crank chamber 940. At this time, the refrigerant pressure in the crank chamber 940 is controlled by adjusting the opening degree of at least one of the first expansion valve 9, the second expansion valve 10, and the three-way valve 710. At this time, the shape of the Mollier diagram is similar to that of FIG. 2 showing the variable capacity operation mode of the first embodiment.

  Next, the maximum discharge capacity operation mode of the vehicle air conditioner in the present embodiment will be described with reference to FIG. When 100% capacity operation is performed in the refrigeration cycle shown in FIG. 10, the three-way valve 710 is closed and expansion is performed by at least one of the first expansion valve 9 and the second expansion valve 10. By closing the three-way valve 710, the pressure by the refrigerant is not supplied to the crank chamber 940 of the compressor 4. At this time, the refrigerant existing in the crank chamber 940 flows out to the suction chamber 960 through a CS passage (not shown). Therefore, the pressure in the crank chamber is reduced, and the discharge capacity of the compressor 4 is approximately 100%. Further, the Mollier diagram in the maximum discharge capacity operation mode of the present embodiment draws the same shape as the maximum discharge capacity operation mode in the first to third embodiments.

  Next, the highly efficient operation mode of the vehicle air conditioner in this embodiment is demonstrated using FIG. FIG. 10 is a diagram showing a refrigeration cycle in the present embodiment.

  When performing high efficiency operation in the refrigeration cycle shown in FIG. 10, expansion is performed by the first expansion valve 9 and the second expansion valve 10. Then, the gas-phase refrigerant in the gas-liquid separator 8 is introduced into the pipe 720 to the cylinder chamber 910 during the compression process by controlling the three-way valve 710 through the pipe 13. Thereafter, the refrigerant introduced by the pipe 720 is guided to the cylinder chamber 910 of the compressor 4 to operate as a two-stage compression / two-stage expansion gas injection cycle. A check valve (not shown) is provided in the middle of the pipe 720. The check valve prevents the refrigerant from flowing back from the cylinder chamber 910. At this time, the pressure by the refrigerant is not supplied to the crank chamber 940 of the compressor 4. Therefore, the refrigerant existing in the crank chamber 940 escapes to the suction chamber 960 through a CS passage (not shown). As a result, the pressure in the crank chamber is reduced, so that the discharge capacity of the compressor 4 is approximately 100%.

  The movement of the refrigeration cycle in the high efficiency operation mode shown in FIG. 10 will be described with reference to FIG. FIG. 11 is a Mollier diagram showing a high-efficiency operation mode in the present embodiment.

  Between the point A7 and the point B7, the temperature of the refrigerant is lowered by exchanging heat with the outside air by the condenser 7, and the refrigerant enters a low-temperature and high-pressure liquid phase state. The refrigerant is decompressed by the first expansion valve 9 between the point B7 and the point C7. At point C7, the gas-liquid separator 8 separates the refrigerant into a gas phase and a liquid phase, the liquid phase refrigerant is introduced into point D7, and the gas phase refrigerant is introduced into the pipe 13 shown in FIG. Between the point D7 and the point E7, the refrigerant is depressurized by the second expansion valve 10 to be in a gas-liquid two-phase state. Between the point E7 and the point F7, the evaporator 12 absorbs heat by exchanging heat with the wind sent by the above-described air-conditioning fan 23, and evaporates to become a gas-phase refrigerant. Between the point F7 and the point A7, the refrigerant is compressed by the compressor 4 to be in a high temperature and high pressure state. The refrigerant separated by the gas-liquid separator 8 passes through the pipe 13 and the three-way valve 710 from the point C7, and is introduced into the cylinder chamber 910 in the compressor 4 during the compression process, that is, the point G7. Thereby, it will be in a two-stage compression state.

From the above, in the high-efficiency operation mode in the present embodiment, the power of the compressor can be reduced by performing the two-stage compression.
(Sixth embodiment)
Next, features of the sixth embodiment of the present invention will be described with reference to FIGS. In addition, the same code | symbol was attached | subjected to the site | part similar to 1st thru | or 5th embodiment.

  In the first to third embodiments, the control valve 14 is used in each operation mode. However, in this embodiment, the three-way valve 810, the pipe 820 from the three-way valve 810 to the suction chamber 960 of the compressor 4, and the compressor 4 are used. The operation mode switching means switches to an operation mode using the pipe 830 to the crank chamber 940 of the engine.

  In this embodiment, in addition to the variable capacity operation mode or the maximum discharge capacity operation mode in the first to third embodiments, a high efficiency operation mode is provided.

First, the variable capacity operation mode of the vehicle air conditioner in the present embodiment will be described with reference to FIG. FIG. 12 is a diagram showing a refrigeration cycle in the present embodiment.
In the variable capacity operation mode in the present embodiment, the gas-phase refrigerant in the gas-liquid separator 8 is introduced into the three-way valve 810 through the pipe 13. Then, the refrigerant is introduced into the pipe 830 to the crank chamber 940 by the three-way valve 810. Thereafter, the refrigerant is guided from the pipe 830 to the crank chamber 940 through the control port 970. The refrigerant introduced into the crank chamber 940 varies the discharge capacity of the compressor 4. At this time, the refrigerant pressure in the crank chamber 940 is controlled by adjusting the opening of at least one of the first expansion valve 9, the second expansion valve 10, and the three-way valve 810. At this time, the Mollier diagram is the same as FIG. 2 showing the variable capacity operation mode of the first embodiment.

  Next, the maximum discharge capacity operation mode of the vehicle air conditioner in the present embodiment will be described with reference to FIG. When the maximum discharge capacity operation is performed in the refrigeration cycle shown in FIG. 12, the three-way valve 810 is closed, and expansion is performed by at least one of the first expansion valve 9 and the second expansion valve 10. By closing the three-way valve 810, the pressure by the refrigerant is not supplied to the crank chamber 940 of the compressor 4. At this time, the refrigerant existing in the crank chamber 940 flows out to the suction chamber 960 through a CS passage (not shown). Therefore, the pressure in the crank chamber is reduced, and the discharge capacity of the compressor 4 is approximately 100%. The Mollier diagram in the maximum discharge capacity operation mode of the present embodiment draws the same shape as the maximum discharge capacity operation mode in the first to third embodiments.

  Next, the highly efficient operation mode of the vehicle air conditioner in this embodiment is demonstrated using FIG. When performing high-efficiency operation in the refrigeration cycle shown in FIG. 12, the first expansion valve 9 is used for expansion. Therefore, the second expansion valve 10 is opened. Then, the gas-phase refrigerant in the gas-liquid separator 8 is introduced into the three-way valve 810 through the pipe 13. Thereafter, the three-way valve 810 is controlled, whereby the refrigerant is introduced into the pipe 820 to the suction chamber 960. The refrigerant introduced into the suction chamber 960 of the compressor 4 through the pipe 820 can increase the suction pressure of the compressor 4. At this time, the pressure by the refrigerant is not supplied to the crank chamber 940 of the compressor 4. Therefore, the refrigerant existing in the crank chamber 940 is discharged to the suction chamber 960 through a CS passage (not shown), and the pressure in the crank chamber is reduced. Therefore, the discharge capacity of the compressor 4 is approximately 100%.

  The movement of the refrigeration cycle in the high efficiency operation mode shown in FIG. 12 will be described with reference to FIG. FIG. 13 is a Mollier diagram showing a high-efficiency operation mode in the present embodiment.

  Between the point A8 and the point B8, the temperature of the refrigerant is lowered by exchanging heat with the outside air by the condenser 7, and the liquid phase is in a low temperature and high pressure state. The refrigerant is decompressed by the first expansion valve 9 between the point B8 and the point C8. At point C8, the gas-liquid separator 8 separates the refrigerant into a gas phase and a liquid phase. The liquid-phase refrigerant separated by the gas-liquid separator 8 absorbs heat by the evaporator 12 by exchanging heat with the wind sent by the above-described air-conditioning fan 23, and the state is changed from the point D8 to the point F8. Change. Further, the gas-phase refrigerant separated by the gas-liquid separator 8 is introduced to the point E8 through the pipe 13 and the three-way valve 810 shown in FIG. Between the point E8 and the point F8, the refrigerant that has passed through the distiller 12 and the gas-phase refrigerant separated by the gas-liquid separator 8 are mixed. At this time, the temperature of the refrigerant is lower than that in the state of passing through the evaporator 12. Between the point F8 and the point A8, the refrigerant is compressed by the compressor 4 to be in a high temperature and high pressure state.

As described above, in the high-efficiency operation mode in the present embodiment, an efficiency improvement effect can be obtained by reducing the evaporator pressure loss.
(Other embodiments)
In the said embodiment, although utilized for the vehicle air conditioner, this invention is not limited to this, You may apply to another refrigerating cycle.

  For example, in the above embodiment, the pressure in the crank chamber 940 is controlled using only the gas-phase refrigerant of the gas-liquid separator 8 in the variable capacity operation mode, but the present invention is not limited to this. The gas phase refrigerant of the gas-liquid separator 8 and the refrigerant discharged from the compressor 4 may be used in combination for the pressure control of the crank chamber 940. Thereby, compared with the case where the pressure of a crank chamber is controlled only with the discharge refrigerant | coolant of a compressor like the conventional compressor, compression efficiency can be improved.

  In the compressor 4 in the above embodiment, the crank chamber is depressurized only by the CS passage. However, the present invention is not limited to the above embodiment, and the depressurization is performed through the control port 970 and other flow paths. You may go.

  In the above embodiment, the swash plate type variable capacity compressor is adopted. However, the present invention is not limited to the above embodiment, and other variable capacity compressors such as a swash plate type compressor are adopted. You may make it do.

  In the fifth embodiment, at least one of the first expansion valve 9 and the second expansion valve 10 is used for the expansion, but the present invention is not limited to this, and the third embodiment The two-stage expansion structure shown in FIG.

  In the sixth embodiment, at least one of the first expansion valve 9 and the second expansion valve 10 is used when performing expansion in the maximum discharge capacity operation mode. However, the present invention is limited to this. Instead, the two-stage expansion structure shown in the third embodiment may be used.

  The present invention is not limited to the above-described embodiment, and may be implemented in any form as long as it does not depart from the invention described in the claims.

It is a figure which shows the vehicle air conditioner in 1st Embodiment thru | or 6th Embodiment. It is a Mollier diagram in the first embodiment. It is a Mollier diagram in the first embodiment. It is a partial sectional view of the compressor in a 1st embodiment. It is a flowchart figure which shows the control flow in 1st Embodiment. It is a TAO-TEO map in 1st Embodiment. It is a Mollier diagram in the second embodiment. It is the Mollier diagram in 3rd Embodiment thru | or 4th Embodiment. It is a figure of the refrigerating cycle in 4th Embodiment. It is a figure of the refrigerating cycle in a 5th embodiment. It is a Mollier diagram in the fifth embodiment. It is a figure of the refrigerating cycle in a 6th embodiment. It is a Mollier diagram in the sixth embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Engine 2 ... Drive pulley 3 ... Passive pulley 4 ... Compressor 5 ... Belt 6 ... Refrigerating cycle 7 ... Condenser 8 ... Gas-liquid separator 9 ... 1st expansion valve 10 ... 2nd expansion valve 11 ... Temperature sensor DESCRIPTION OF SYMBOLS 12 ... Evaporator 13 ... Piping 14 ... Control valve 21 ... Air conditioning unit 22 ... Air conditioning case 23 ... Air conditioning fan 24 ... Heater core 25 ... Air mix door 31 ... Air conditioner ECU
32 ... Inside air temperature sensor 33 ... Outside air temperature sensor 34 ... Insolation sensor 35 ... Evaporator post-temperature sensor 36 ... Temperature setting device 37 ... Air conditioner switch 710 ... Three-way valve 720 ... Pipe to cylinder chamber 730 ... Pipe to crank chamber 810 ... Three-way valve 820 ... Piping to suction port 830 ... Piping to crank chamber 901 ... Housing 901a ... Front housing 901b ... Middle housing 901c ... Rear housing 901d ... Boss portion 901e ... Seal member 901f ... Front side bearing 901g ... Rear side bearing 910 ... Cylinder chamber 911 ... Piston 920 ... Shaft 920b ... Lug plate 921 ... CS passage inlet 922 ... CS passage outlet 930 ... Swash plate 940 ... Crank chamber 950 ... Discharge chamber 960 ... Suction chamber

Claims (9)

A condenser (7) for cooling the compressed refrigerant, a first expansion valve (9) for expanding the refrigerant cooled in the condenser (7), and the first expansion valve (9). A gas-liquid separator (8) for performing gas-liquid separation of the refrigerant, a second expansion valve (10) for expanding the liquid-phase refrigerant separated by the gas-liquid separator (8), and the second In response to the pressure of the evaporator (12) that receives the refrigerant expanded by the expansion valve (10), receives heat from the outside, and evaporates the refrigerant by latent heat of vaporization, and the crank chamber (940) provided inside A compressor (4) that sucks and compresses the gas-phase refrigerant that has passed through the evaporator (12) with a determined capacity and discharges it to the condenser (7);
A pipe (13) for guiding the gas-phase refrigerant in the gas-liquid separator (8) to the compressor crank chamber (940), and the pressure of the refrigerant led to the crank chamber (940) by the pipe (13). A refrigeration cycle comprising discharge volume control means (15) for controlling.   The refrigerating cycle of Claim 1 WHEREIN: The target discharge capacity determination means which determines the target discharge capacity of the said compressor (4), The expansion valve which measures the refrigerant | coolant pressure before passing the said 1st expansion valve (9) Further comprising an upstream pressure measuring means, wherein the discharge capacity control means (15) is configured to obtain a target discharge capacity determined by the target discharge capacity determining means and a refrigerant pressure measured by the expansion valve upstream pressure measuring means. Based on this, the opening degree of the first expansion valve (9) and the second expansion valve (10) is adjusted, and the pressure of the crank chamber (940) is adjusted to the discharge capacity of the compressor (4). A refrigerating cycle characterized by adjusting the pressure to be a capacity.   The refrigeration cycle according to claim 1, wherein target discharge capacity determining means for determining a target discharge capacity of the compressor (4) and gas-liquid separator internal pressure measurement for measuring refrigerant pressure in the gas-liquid separator (8). The discharge capacity control means (15) includes a control valve (14) provided in the pipe (13), and the control valve (14) is determined by the target discharge capacity determination means. Based on the measured target discharge capacity and the refrigerant pressure measured by the gas-liquid separator internal pressure measuring means, the pressure of the crank chamber (940) is changed to the discharge capacity of the compressor (4) as the target discharge capacity. A refrigeration cycle characterized by adjusting to pressure.   The refrigeration cycle according to claim 3, wherein the discharge capacity control means (15) realizes the first expansion valve (9) and the refrigerant pressure in the gas-liquid separator (8) achieves the target discharge capacity. The refrigeration cycle is controlled so as to be higher than the pressure in the crank chamber (940).   5. The normal operation according to claim 3, further comprising an operating state switching unit that switches an operating state of the refrigeration cycle, wherein the operating state switching unit controls a discharge capacity of the compressor (4) by the discharge capacity control unit. And the first expansion mode operation state in which the control valve (14) is closed, the refrigerant is expanded by the first expansion valve (9), and introduced into the evaporator (12). Refrigeration cycle.   In Claim 3, The operation state switching means which switches the operation state of the said refrigerating cycle is further provided, The said operation state switching means controls the discharge capacity of the said compressor (4) by the said discharge capacity control means (15) normally In an operating state, the control valve (14) is closed, the first expansion valve (9) is released, and the refrigerant that has passed through the condenser (7) is expanded by the second expansion valve (10). A refrigeration cycle, wherein the second expansion mode operating state to be introduced into the evaporator (12) is switched.   In Claim 3, The operation state switching means which switches the operation state of the said refrigerating cycle is further provided, The said operation state switching means controls the discharge capacity of the said compressor (4) by the said discharge capacity control means (15) normally In the operating state, the control valve (14) is closed, the refrigerant is expanded using the first expansion valve (9) and the second expansion valve (10), and introduced into the evaporator (12). A refrigeration cycle that switches between a third expansion mode operation state.   In claim 1, further comprising an operation state switching means for switching the operation state of the refrigeration cycle, the discharge capacity control means (15) is provided in the pipe (13), the refrigerant flowing through the pipe (13), The compressor cylinder chamber (910) or the three-way valve (710) leading to the crank chamber (940) is provided, and the operating state switching means controls the discharge capacity control by controlling the three-way valve (710). A normal operating state in which the discharge capacity of the compressor (4) is controlled by means (15), and the gas-phase refrigerant separated in the gas-liquid separator (8) in the cylinder chamber (910) during the compression step. A refrigeration cycle characterized by switching between a two-stage compression mode state to be introduced.   In claim 1, further comprising an operation state switching means for switching the operation state of the refrigeration cycle, the discharge capacity control means (15) is provided in the pipe (13), the refrigerant flowing through the pipe (13), It has a three-way valve (810) that leads to the compressor suction port or the crank chamber (940), and the operation state switching means controls the three-way valve (810), thereby controlling the discharge capacity control means (15 ), The normal operating state in which the discharge capacity of the compressor (4) is controlled, and the gas-phase refrigerant separated by the gas-liquid separator (8) is introduced into the compressor inlet, and the liquid-phase refrigerant is A refrigerating cycle characterized in that it switches between the state of a refrigerant cooling mode introduced into the evaporator (12).

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