JP5413857B2 - Air conditioner for vehicles - Google Patents

Description

  The present invention relates to a vehicle air conditioner, and more particularly to control of the introduction amount of inside and outside air according to the refrigerant pressure of a refrigeration circuit.

Conventionally, in a vehicle air conditioner having a vapor compression refrigeration circuit mainly composed of a compressor, a radiator, a decompressor, and an evaporator, the pressure on the high pressure side from the compressor to the decompressor of the refrigeration circuit excessively increases. In order to prevent this, the driving of the compressor is stopped when the high-pressure side pressure exceeds a predetermined pressure.
Or the variable capacity compressor which can change capacity | capacitance was provided, and when the high pressure side pressure became more than predetermined pressure, the refrigerant | coolant pressure was reduced by reducing the capacity | capacitance of the said compressor (refer patent document 1).

JP 59-112156 A

However, when the drive of the compressor is stopped as in the prior art or the capacity of the compressor is reduced as in Patent Document 1, the refrigerant flow rate is lowered and the air cooling performance in the evaporator is lowered, so that the passenger compartment As a result, the passenger's occupant may feel uncomfortable.
Further, when the operation is restarted after stopping or limiting the operation of the compressor, the refrigeration cycle of the refrigeration circuit may become unstable.

  The present invention has been made to solve such a problem, and the object of the present invention is to prevent an increase in the refrigerant pressure while preventing the performance of the refrigeration circuit from degrading or becoming unstable. It is providing the vehicle air conditioner.

In order to achieve the above-described object, in the vehicle air conditioner of the first aspect, a duct that is disposed in a vehicle interior of the vehicle and capable of introducing air from the vehicle interior and the exterior of the vehicle, is mounted on the vehicle, and has an interior. A refrigeration circuit in which the refrigerant circulates, a compressor that forms part of the refrigeration circuit, operates to pump the refrigerant in the refrigeration circuit, and forms part of the refrigeration circuit, provided in the duct, An evaporator that cools air passing through the duct using the heat of vaporization of the refrigerant, a vehicle interior temperature detection unit that detects a temperature inside the vehicle interior, and a vehicle exterior temperature detection unit that detects a temperature outside the vehicle interior And a refrigerant pressure detecting means for detecting a refrigerant pressure on the high pressure side of the refrigeration circuit, and an inside / outside air introduction amount capable of adjusting a ratio of an air introduction amount from the vehicle interior to the duct and an air introduction amount from the outside of the vehicle interior. By the adjusting means and the passenger compartment temperature detecting means Refrigerant detected by the refrigerant pressure detecting means by setting a plurality of predetermined pressures having different values when the temperature in the passenger compartment is in a state lower than the outside temperature detected by the outside temperature detecting means. The inside / outside air introduction amount control means for increasing the air introduction amount ratio from the vehicle interior by a predetermined amount by the inside / outside air introduction amount adjustment means each time the pressure becomes larger than each predetermined pressure, and a part of the refrigeration circuit. A blower provided in the duct and driven by a motor to blow air toward the downstream side of the air flow in the duct, and an air introduction amount from the vehicle interior in the duct is increased by the inside / outside air introduction amount control means in response to the, than the supply voltage to the motor when introducing only air from the vehicle outside within the duct, the fan by reducing the supply voltage to the motor It is characterized with blower control means for reducing the air blowing amount, further comprising a that.

In the vehicle air conditioner according to claim 2, a duct that is disposed in a vehicle interior of the vehicle and capable of introducing air from the vehicle interior and the exterior of the vehicle, a refrigeration circuit that is mounted on the vehicle and in which a refrigerant circulates, A compressor that forms part of the refrigeration circuit and operates to pump the refrigerant in the refrigeration circuit; and a part of the refrigeration circuit that is provided in the duct and uses the heat of vaporization of the refrigerant to An evaporator for cooling the air passing through the duct, a vehicle interior temperature detection means for detecting the temperature inside the vehicle interior, a vehicle exterior temperature detection means for detecting the temperature outside the vehicle interior, and a high pressure side of the refrigeration circuit Refrigerant pressure detection means for detecting refrigerant pressure, inside / outside air introduction amount adjustment means capable of adjusting the ratio of the amount of air introduced into the duct from the passenger compartment and the amount of air introduced from the passenger compartment, and the passenger compartment temperature detection The vehicle interior temperature detected by the means is the vehicle interior When the refrigerant pressure detected by the refrigerant pressure detection means rises when the temperature is lower than the vehicle exterior temperature detected by the temperature detection means, the air from the vehicle interior is increased by the inside / outside air introduction amount adjustment means. Inside / outside air introduction amount control means for continuously increasing the introduction amount ratio and a part of the refrigeration circuit, provided in the duct, driven by a motor to blow air toward the downstream side of the air flow in the duct To the motor for introducing only air from outside the vehicle interior in the duct in response to an increase in the amount of air introduced from the vehicle interior in the duct by the blower and the inside / outside air introduction amount control means Blower control means for lowering the amount of air blown by the blower by lowering the supply voltage to the motor rather than the supply voltage .

  According to a third aspect of the present invention, in the air conditioning apparatus for a vehicle according to the first aspect, the inside / outside air introduction amount control means respectively sets a second predetermined pressure having a value lower than the predetermined pressure by a certain amount, and the inside / outside air introduction amount. When the refrigerant pressure detected by the refrigerant pressure detecting means becomes smaller than the second predetermined pressure after increasing the amount of air introduced from the passenger compartment by the adjusting means, the increased pressure from the passenger compartment is reduced. It is characterized by returning to the state before increasing the air introduction amount ratio.

The air-conditioning system 請 Motomeko 4, in any one of claims 1 to 3, characterized by using carbon dioxide as the refrigerant.

In vehicular air conditioning apparatus according to claim 5, in any one of claims 1 to 4, wherein the refrigerant pressure detecting means, from the compressor of the refrigeration circuit, a radiator for reducing the temperature of the refrigerant disposed in the refrigeration circuit The refrigerant | coolant pressure between these is detected.

The vehicle air conditioner according to claim 1 of the present invention using the above means adjusts the ratio of the inside / outside air introduction amount into the duct in a stepwise manner according to the high-pressure side refrigerant pressure of the refrigeration circuit. The temperature difference between the temperature and the evaporator, that is, the cooling load of the evaporator is adjusted, and the work amount of the compressor is adjusted.
By adjusting the work amount of the compressor by such inside / outside air control, it is possible to adjust the refrigerant pressure on the high pressure side of the refrigeration circuit without destabilizing the refrigeration circuit while maintaining the performance of the compressor. It is possible to prevent the refrigerant pressure from being increased.

In particular, rather than simply switching between the internal air circulation mode and the external air introduction mode by setting a plurality of predetermined pressures and increasing the internal air introduction amount ratio by a predetermined amount each time the high-pressure side refrigerant pressure becomes larger than each predetermined pressure. Thus, the inside / outside air introduction amount control according to the high-pressure side refrigerant pressure can be performed more appropriately.
Also, when the outside temperature of the passenger compartment is higher than the temperature inside the passenger compartment, the cooling load of the evaporator can be reliably reduced by efficiently increasing the ratio of the inside air introduction amount, and the high-pressure side refrigerant pressure can be lowered efficiently. Can do.
Furthermore, it is possible to save power by reducing the supply voltage to the motor of the blower in accordance with the inside air introduction amount ratio.

According to the vehicle air conditioner of the second aspect, by continuously adjusting the ratio of the inside / outside air introduction amount into the duct according to the high-pressure side refrigerant pressure of the refrigeration circuit, the air temperature in the duct, the evaporator, The difference in temperature of the compressor, that is, the cooling load of the evaporator is adjusted, and the work amount of the compressor is adjusted.
By adjusting the work amount of the compressor by such inside / outside air control, it is possible to adjust the refrigerant pressure on the high pressure side of the refrigeration circuit without destabilizing the refrigeration circuit while maintaining the performance of the compressor. It is possible to prevent the refrigerant pressure from being increased.

In particular, by increasing the internal air introduction amount ratio as the high-pressure side refrigerant pressure increases, it is possible to control the internal / external air introduction amount more appropriately according to the high-pressure side refrigerant pressure than simply switching between the internal air circulation mode and the external air introduction mode. It can be performed.
Also, when the outside temperature of the passenger compartment is higher than the temperature inside the passenger compartment, the cooling load of the evaporator can be reliably reduced by efficiently increasing the ratio of the inside air introduction amount, and the high-pressure side refrigerant pressure can be lowered efficiently. Can do.
Furthermore, it is possible to save power by reducing the supply voltage to the motor of the blower in accordance with the inside air introduction amount ratio.

  According to the vehicle air conditioner of the third aspect, the high-pressure side refrigerant pressure becomes smaller than the second predetermined pressure that is lower than the predetermined pressure by a certain amount after the inside air introduction amount ratio is increased according to the high-pressure side refrigerant pressure. In this case, by returning the increase in the ratio of the inside air introduction amount to the original, it is possible to prevent hunting and return the inside / outside air introduction amount satisfactorily.

According to the vehicle air conditioner of the fourth aspect , by using carbon dioxide as the refrigerant, a refrigeration circuit suitable for the environment can be obtained.
According to the vehicle air conditioner of the fifth aspect , the high-pressure side refrigerant pressure can be detected accurately by detecting the high-pressure side refrigerant pressure between the compressor and the radiator.

It is a schematic block diagram of the vehicle air conditioner which concerns on this invention. It is a flowchart which shows the basic inside / outside air control routine performed by the air conditioner ECU of the vehicle air conditioner. It is a flowchart which shows the inside / outside air control routine performed by air conditioner ECU of the vehicle air conditioner which concerns on the Example of this invention. It is a map which shows the inside / outside air introduction amount control which concerns on an Example. It is a map which shows blower control concerning an example.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Referring to FIG. 1, there is shown a schematic configuration diagram of a vehicle air conditioner according to the present invention.
FIG. 1 schematically shows a front portion of a vehicle. An air conditioner (air conditioner) is a vehicle compartment partitioned by a partition wall 6 from an engine room 4 in which a vehicle engine 2 (internal combustion engine) is disposed. It is composed of eight.

A ventilation duct 10 that forms an air passage of the air conditioner is provided in an instrument panel (not shown) in the vehicle interior 8.
The instrument panel has differential, face, and foot air outlets (not shown) formed at predetermined positions, respectively. Three openings 12a, 12b, and 12c for the differential, the face, and the foot that communicate with each other are formed.

Each of the openings 12a, 12b, and 12c is provided with a differential door 14a, a face door 14b, and a foot door 14c for opening and closing the corresponding openings 12a, 12b, and 12c.
On the other hand, on the other end side of the ventilation duct 10, an inside air introduction port 20 communicating with the vehicle interior 8 and an outside air introduction port 22 communicating with the outside of the vehicle interior are formed adjacent to each other. And between the inside air introduction port 20 and the outside air introduction port 22, it can be rotated from the inside air introduction port 20 side to the outside air introduction port 22 side, and by changing the opening degree, The inside / outside air adjustment damper 24 (inside / outside air introduction amount adjusting means) capable of adjusting the ratio of the air introduction amount is provided.

In the ventilation duct 10 configured as described above, an air flow is formed from the inside air introduction port 20 and the outside air introduction port 22 on the other end side to the openings 12a, 12b, and 12c on the one end side.
The ventilation duct 10 is provided with a blower 30 (blower), an evaporator 32 (evaporator), and a heater core 34 in order from the other end side to the one end side.
The blower 30 is provided on the other end side inside the ventilation duct 10, in the vicinity of the air flow downstream side of the inside air introduction port 20 and the outside air introduction port 22. The blower 30 is a so-called centrifugal blower driven by a motor 30 a and has a function of blowing air toward one end of the ventilation duct 10.

The evaporator 32 forms a part of the refrigeration circuit 40, the refrigerant circulating in the refrigeration circuit 40 is evaporated inside, and the air passing through the outside of the evaporator 32 using the heat of vaporization, that is, in the ventilation duct 10. It has the function of cooling the air.
The heater core 34 has a function of heating the air passing through the heater core 34 in the ventilation duct 10 by heating the heater core 34 as the cooling water that has been heated through the engine 2 flows through the heater core 34. ing.

An air mix door 36 is provided at a position directly upstream of the air flow of the heater core 34. The air mix door 36 has a function of adjusting the amount of air reheated by the heater core 34 out of the amount of air cooled by the evaporator 32 by opening and closing and adjusting the amount of air flow to the heater core 34. Yes.
In the refrigeration circuit 40, CO ₂ (carbon dioxide), which is a natural refrigerant suitable for the environment, circulates inside to form a refrigeration cycle. The compressor 42, the gas cooler are arranged in the order of the refrigeration cycle. (Heat radiator) 44, high temperature part 46a of internal heat exchanger 46, decompressor 48, evaporator 32, accumulator 50 (gas-liquid separator), and low temperature part 46b of internal heat exchanger 46 are inserted. .

  The compressor 42 is a variable capacity compressor, and a pulley 42b is provided at one end via an electromagnetic clutch 42a. The pulley 42b is connected to a pulley 2a provided at one end of the drive shaft of the engine 2 via a belt 2b. The compressor 42 is connected and disconnected by the electromagnetic clutch 42a, so that power from the engine 2 is transmitted and disconnected. The compressor 42 has a function of compressing the refrigerant in the refrigeration circuit 40 and sending it to the radiator 44 by operating with the power transmitted from the engine 2.

  The gas cooler 44 cools the high-temperature and high-pressure refrigerant compressed by the compressor 42, and the internal heat exchanger 46 exchanges heat between the refrigerant passing through the high-temperature part 46a and the refrigerant passing through the low-temperature part 46b. The decompressor 48 depressurizes the refrigerant to form a mist, and the accumulator 50 removes the liquid phase component remaining in the refrigerant that has evaporated at the evaporator 32 to a low temperature and low pressure.

Further, an air conditioner ECU (electronic control unit) 60 is provided in the passenger compartment 8, and the air conditioner ECU 60 is a storage device (ROM, RAM, And a central processing unit (CPU), a timer counter, and the like.
A high pressure side refrigerant pressure sensor 62 (refrigerant pressure detecting means) is provided between the compressor 42 and the radiator 44 of the refrigeration circuit 40 and detects the high pressure side refrigerant pressure in the refrigeration circuit 40 on the input side of the air conditioner ECU 60. A vehicle interior temperature sensor 64 (vehicle interior temperature detection means) provided in the vehicle interior 8 for detecting the vehicle interior temperature Tin, an outdoor air temperature sensor 66 (vehicle interior outside temperature detection means) provided outside the vehicle interior for detecting the outside air temperature Tamb, etc. The various sensors are electrically connected.

The output side of the air conditioner ECU 60 is electrically connected to an actuator 24a for driving the inside / outside air adjustment damper 24, a motor 30a for the blower 30, an actuator 36a for driving the air mix door 36, a clutch controller 42c for the electromagnetic clutch 42a, and the like. Has been.
The air conditioner ECU 60 has a function of controlling various devices based on information from the sensors to perform air conditioning control (hereinafter also referred to as air conditioner control). For example, the air conditioner ECU 60 adjusts the blower voltage BLV supplied to the motor 30a of the blower 30. (Air blower control means), or by controlling the opening degree of the inside / outside air adjusting damper 24 according to the high-pressure side refrigerant pressure in the refrigeration circuit 40 to adjust the ratio of the amount of air introduced into the ventilation duct 10 Air control is performed (inside / outside air introduction amount control means).

Hereinafter, the inside / outside air control executed by the air conditioner ECU 60 in the vehicle air conditioner according to the present invention configured as described above will be described in detail.
First, basic inside / outside air control will be described. Here, the inside air circulation mode in which the inside air introduction port 20 is opened by the inside / outside air regulating damper 24 and the outside air introduction port 22 is closed, and the outside air introduction mode in which the inside air introduction port 20 is closed and the outside air introduction port 22 is opened. An air introduction mode can be selected.

Referring to FIG. 2, a basic inside / outside air control routine executed by the air conditioner ECU 60 of the vehicle air conditioner is shown in a flowchart, which will be described below.
First, in step S1, each information is read from the various sensors. Specifically, the high pressure side refrigerant pressure Pd is read from the high pressure side refrigerant pressure sensor 62, the vehicle interior temperature sensor 64 is read from the vehicle interior temperature Tin, the outside air temperature sensor 66 is read from the outside air temperature Tamb, and the blower voltage BLV of the motor 30a of the blower 30 is read.

  In the next step S2, it is determined whether or not the high-pressure side refrigerant pressure Pd read in step S1 is higher than a predetermined pressure Pa set in advance. The predetermined pressure Pa is set to a value slightly lower than the upper limit pressure at which normal operation of the compressor 42 is ensured, for example. If the determination result is false (No), the routine is returned. On the other hand, if the determination result is true (Yes), the process proceeds to step S3.

In step S3, it is determined whether or not the outside air temperature Tamb read in step S1 is higher than the vehicle interior temperature Tin. If the determination result is false (No), the routine is returned. On the other hand, if the determination result is true (Yes), that is, if the outside air temperature Tamb is higher than the vehicle interior temperature Tin, the process proceeds to step S4.
In step S4, it is determined whether or not the air introduction mode is set to the outside air introduction mode. When the determination result is false (No), that is, when the inside air circulation mode is set, the routine is returned. On the other hand, if the determination result is true (Yes), the process proceeds to step S5.

In step S5, the inside / outside air adjustment damper 24 is controlled so as to switch the air introduction mode from the outside air introduction mode to the inside air circulation mode, and in the next step S6, the blower voltage BLV supplied to the motor 30a is reduced to a preset predetermined voltage. Let
In step S7, the high-pressure side refrigerant pressure Pd is read again. In step S8, it is determined whether or not the high-pressure side refrigerant pressure Pd is higher than the second predetermined pressure Pb. The predetermined pressure Pb is set to a value lower than the predetermined pressure Pa. For example, the predetermined pressure Pb is set to a value sufficiently lower than the upper limit pressure at which normal operation of the compressor 42 is ensured. If the determination result is false (No), the process returns to step S7 to repeat the determination of the high-pressure side refrigerant pressure Pd. If the determination result is true (Yes), the process proceeds to step S9.

In step S9, the inside / outside air adjustment damper 24 is returned to the outside air introduction mode to return to normal inside / outside air adjustment damper control.
In the next step S10, the blower voltage BLV is returned to the original value before being lowered in step S6, the normal blower voltage control is restored, and the routine is returned.
As described above, in the inside / outside air control, when the vehicle interior temperature Tin is lower than the outside air temperature Tamb during operation in the outside air introduction mode, the high pressure side refrigerant pressure Pd of the refrigeration circuit 40 becomes equal to or higher than the predetermined pressure Pa. The inside / outside air adjustment damper 24 is switched to the inside air circulation mode.

By switching to the inside air circulation mode, the air temperature in the ventilation duct 10 decreases, and the temperature difference between the air temperature and the evaporator 32 decreases. Thereby, since the cooling load of the evaporator 32 is reduced, the work amount in the compressor 42 is also reduced, and the high-pressure side refrigerant pressure Pd can be lowered.
Further, when the high-pressure side refrigerant pressure Pd is lowered and becomes smaller than the second predetermined pressure Pb as described above, the normal control is restored. Since the second predetermined pressure Pb is set to a value lower than the predetermined pressure Pa, it is possible to prevent a hunting phenomenon that repeatedly switches between the internal air circulation mode and the external air introduction mode before and after the predetermined pressure Pa. The normal control can be satisfactorily restored.

In addition, switching to the inside air circulation mode and reducing the blower voltage BLV supplied to the motor 30a of the blower 30 can save power.
As described above, in the vehicle air conditioner, by adjusting the work amount of the compressor by the above-described inside / outside air control, the performance of the compressor 42 is maintained and the refrigeration circuit is destabilized. In addition, the high-pressure side refrigerant pressure Pd of the refrigeration circuit 40 can be reduced and the increase in the refrigerant pressure can be suppressed.

Next, examples of the present invention will be described. In this embodiment, the inside / outside air adjustment damper 24 can adjust the opening degree in stages.
Referring to FIGS. 3 to 5, FIG. 3 is a flowchart showing an inside / outside air control routine executed by the air conditioner ECU 60 according to the embodiment, and FIG. 4 is a map showing inside / outside air introduction amount control according to the embodiment. Reference numeral 5 denotes a map showing blower control according to the embodiment. Hereinafter, description will be made along the flowchart of FIG. 3 with reference to FIGS.

  First, Step S20 and Step S21 are the same as S1 and S3 in the flowchart of FIG. 2 described above, and each information is read from the various sensors and the like, and whether or not the outside air temperature Tamb is larger than the vehicle interior temperature Tin. Is determined. If the determination result in step S21 is false (No), the routine is returned. If the determination result is true (Yes), the process proceeds to step S22.

In step S22, inside / outside air adjustment damper control is performed.
In the inside / outside air adjustment damper control, as shown in FIG. 4, the opening degree θ of the inside / outside air adjustment damper is adjusted according to the high-pressure side refrigerant pressure Pd.
Specifically, when the high-pressure side refrigerant pressure Pd increases, predetermined pressures Px1, Px2, and Px3 are set as threshold values for the high-pressure side refrigerant pressure Pd, and each time the high-pressure side refrigerant pressure Pd becomes equal to or higher than the predetermined pressure, The opening degree of the air adjustment damper 24 is rotated to the inside air circulation mode side, that is, the outside air introduction port 22 side.

  Specifically, when the high-pressure side refrigerant pressure Pd increases from the state of the outside air introduction mode with the opening degree θamb to close the inside air introduction port 20 and becomes larger than the predetermined pressure Px1, the inside / outside air adjustment damper 24 is turned on. The opening degree θa is a predetermined amount rotated to the outside air inlet 22 side. Further, when the high-pressure side refrigerant pressure Pd rises and becomes larger than the predetermined pressure Px2, the opening degree θb is obtained by further rotating the inside / outside air adjustment damper 24 toward the outside air inlet side. When the high-pressure side refrigerant pressure Pd becomes larger than the predetermined pressure Px3, the inside / outside air adjusting damper 24 is rotated to the opening degree θin for closing the outside air introduction port 22, that is, the inside air circulation mode.

On the other hand, when the high-pressure side refrigerant pressure Pd decreases, the second predetermined pressures Py1, Py2, Py3 set to a value lower by a predetermined amount than the predetermined pressures Px1, Px2, Px3 are set. Each time the refrigerant pressure Pd becomes smaller than the second predetermined pressure, the opening degree of the inside / outside air adjustment damper is returned by a predetermined amount.
Specifically, from the state of the inside air circulation mode, that is, the opening degree θin, when the high-pressure side refrigerant pressure Pd becomes Py3 or less, the inside / outside air adjustment damper opening degree becomes the opening degree θb, and further when Py2 or less, the opening degree When θa further becomes Py3 or less, the opening degree θamb, that is, the outside air introduction mode is switched.

And after performing the said inside / outside air adjustment damper control, blower voltage control is performed in the following step S23.
In the blower voltage control, the blower voltage BLV is adjusted according to the inside / outside air adjustment damper opening θ based on the map of FIG.
In the map of FIG. 5, the blower voltage BLV is set to decrease by a predetermined amount as the opening degree of the inside / outside air adjustment damper 24 moves from the opening degree θamb on the outside air introduction mode side to the opening degree θin on the inside air introduction mode side. .

Then, after executing the control in step S24, the routine returns.
As described above, in the inside / outside air control in this embodiment, a plurality of predetermined pressures Px1, Px2, and Px3 are set, and each time the high-pressure side refrigerant pressure Pd becomes larger than the predetermined pressure, the inside air introduction amount ratio is set to a predetermined amount. It is supposed to increase.
Each time the predetermined pressures Px1, Px2, Px3 are set to a predetermined lower value, the second predetermined pressures Py1, Py2, Py3 are set, and the high-pressure side refrigerant pressure Pd becomes smaller than the second predetermined pressure. The opening degree θ of the inside / outside air adjustment damper 24 is returned.

Furthermore, the blower voltage BLV is also controlled according to the opening degree θ of the inside / outside air switching damper 24.
As described above, in the vehicle air conditioner according to the embodiment of the present invention, the same effect as the basic inside / outside air control can be obtained, and the opening degree of the inside / outside air regulating damper 24 can be set by setting a plurality of predetermined pressures. Since θ is adjusted stepwise, it is possible to more appropriately control the inside / outside air introduction amount according to the high-pressure side refrigerant pressure Pd.

Although the description about embodiment of the vehicle air conditioner concerning this invention is finished above, embodiment is not restricted to the said embodiment.
For example, in the above embodiment, the blower voltage is controlled together with the control of the introduction amount of the inside / outside air, but the inside / outside air control in which the control of the blower voltage is not performed as shown by the one-dotted line in FIGS. .

In the above-described embodiment, the three predetermined pressures Px1, Px2, and Px3 are set as the predetermined pressure. However, the predetermined pressure may be set in any number of steps. Moreover, in order to perform the inside / outside air control according to the high-pressure side refrigerant pressure Pd more appropriately, the control may be made to continuously increase the inside air introduction amount ratio as the high-pressure side refrigerant pressure Pd increases.
In addition, the configuration of the refrigeration circuit 40, the compressor 42, and the inside / outside air adjustment damper 24 is not limited to that of the above embodiment, and in the above embodiment, the refrigeration circuit 40 includes an internal heat exchanger 46 and an accumulator. However, the present invention is not limited to such a configuration. For example, a configuration in which an internal heat exchanger is not provided, or a configuration in which a receiver is provided on the downstream side of the refrigeration cycle of the radiator may be used.

Moreover, in the said embodiment, although the compressor 42 is a variable capacity type, it is not restricted to the said variable capacity type.
Further, in the above embodiment, the inside / outside air introduction damper 24 is provided as the inside / outside air introduction amount adjusting means. However, the configuration of the inside / outside air introduction amount adjusting means is not limited to this, for example, the inside air introduction port and the outside air introduction port. A configuration in which a damper is provided for each of these may be used.

  In the above embodiment, the high-pressure side refrigerant pressure Pd, the vehicle interior temperature Tin, and the outside air temperature Tamb are detected by the high-pressure side refrigerant pressure sensor 62, the vehicle interior temperature sensor 64, the outside air temperature sensor 66, and the like. You may detect by.

2 Engine 10 Ventilation duct 20 Inside air introduction port 22 Outside air introduction port 24 Inside / outside air adjustment damper (inside / outside air introduction amount adjusting means)
30 Blower (blower)
30a Motor 32 Evaporator
40 Refrigeration circuit 42 Compressor 44 Gas cooler (radiator)
48 Pressure reducer 60 Air conditioner ECU (inside / outside air introduction amount control means, blower control means)
62 High-pressure side refrigerant pressure sensor (refrigerant pressure detection means)
64 Vehicle interior temperature sensor (vehicle interior temperature detection means)
66 Outside temperature sensor (vehicle exterior temperature detection means)

Claims (5)

A duct disposed in a vehicle interior of the vehicle and capable of introducing air from the vehicle interior and the exterior of the vehicle;
A refrigeration circuit mounted in the vehicle, in which a refrigerant circulates;
A compressor that forms part of the refrigeration circuit and that operates to pump the refrigerant in the refrigeration circuit;
An evaporator that forms part of the refrigeration circuit, is provided in the duct, and cools air passing through the duct using heat of vaporization of the refrigerant;
Vehicle interior temperature detecting means for detecting the temperature in the vehicle interior;
Vehicle exterior temperature detection means for detecting the temperature outside the vehicle compartment;
Refrigerant pressure detection means for detecting the refrigerant pressure on the high pressure side of the refrigeration circuit;
An inside / outside air introduction amount adjusting means capable of adjusting the ratio of the amount of air introduced from the passenger compartment into the duct and the amount of air introduced from the passenger compartment;
When the passenger compartment temperature detected by the passenger compartment temperature detection means is lower than the passenger compartment outside temperature detected by the passenger compartment temperature detection means, a plurality of predetermined pressures having different values are set, and the refrigerant pressure An inside / outside air introduction amount control means for increasing a ratio of the amount of air introduced from the vehicle interior by a predetermined amount by the inside / outside air introduction amount adjustment means each time the refrigerant pressure detected by the detection means becomes larger than the respective predetermined pressures;
A blower that forms part of the refrigeration circuit, is provided in the duct, is driven by a motor, and blows air toward the downstream side of the air flow in the duct;
Supply voltage to the motor when only air from outside the vehicle interior in the duct is introduced in response to an increase in the amount of air introduced from the vehicle interior in the duct by the inside / outside air introduction amount control means Rather than lowering the supply voltage to the motor, blower control means for lowering the amount of air blown by the blower,
A vehicle air conditioner comprising: A duct disposed in a vehicle interior of the vehicle and capable of introducing air from the vehicle interior and the exterior of the vehicle;
A refrigeration circuit mounted in the vehicle, in which a refrigerant circulates;
A compressor that forms part of the refrigeration circuit and that operates to pump the refrigerant in the refrigeration circuit;
An evaporator that forms part of the refrigeration circuit, is provided in the duct, and cools air passing through the duct using heat of vaporization of the refrigerant;
Vehicle interior temperature detecting means for detecting the temperature in the vehicle interior;
Vehicle exterior temperature detection means for detecting the temperature outside the vehicle compartment;
Refrigerant pressure detection means for detecting the refrigerant pressure on the high pressure side of the refrigeration circuit;
An inside / outside air introduction amount adjusting means capable of adjusting the ratio of the amount of air introduced from the passenger compartment into the duct and the amount of air introduced from the passenger compartment;
When the passenger compartment temperature detected by the passenger compartment temperature detecting means is lower than the passenger compartment outside temperature detected by the passenger compartment outside temperature detecting means, the refrigerant pressure detected by the refrigerant pressure detecting means increases. Accordingly, the inside / outside air introduction amount control means for continuously increasing the air introduction amount ratio from the vehicle interior by the inside / outside air introduction amount adjusting means,
A blower that forms part of the refrigeration circuit, is provided in the duct, is driven by a motor, and blows air toward the downstream side of the air flow in the duct;
Supply voltage to the motor when only air from outside the vehicle interior in the duct is introduced in response to an increase in the amount of air introduced from the vehicle interior in the duct by the inside / outside air introduction amount control means Rather than lowering the supply voltage to the motor, blower control means for lowering the amount of air blown by the blower,
A vehicle air conditioner comprising:   The inside / outside air introduction amount control means sets a second predetermined pressure that is a certain amount lower than each of the predetermined pressures, and increases the amount of air introduced from the vehicle interior by the inside / outside air introduction amount adjustment means. When the refrigerant pressure detected by the refrigerant pressure detecting means becomes smaller than the second predetermined pressure, the increased air introduction amount ratio from the vehicle interior is returned to the state before the increase. The vehicle air conditioner according to claim 1.   The vehicle air conditioner according to any one of claims 1 to 3, wherein carbon dioxide is used as the refrigerant.   5. The refrigerant pressure detection means detects a refrigerant pressure between the compressor of the refrigeration circuit and a radiator provided in the refrigeration circuit for reducing the temperature of the refrigerant. Any one of the vehicle air conditioners.

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