JPH07285326A - Heat pump type cooling/heating device for vehicle - Google Patents

Abstract

PURPOSE:To keep the effective temperature of an occupant constant in the environment requiring frequent switching of cooling and heating by starting the distribution of a refrigerant to a heat exchanger outside a car room and a blast in response to the prescribed temperature difference between the estimated value and target value of the blowout temperature when the heating operation state is changed to the cooling operation state. CONSTITUTION:A three-way valve 32 distributing a refrigerant from a compressor 31 to a heat exchanger 38 outside a car room and a heat exchanger 33 in the car room for radiation is controlled by a control device 43 based on the heat environmental information together with a cooling fan 30, the compressor 31, and a blower motor 44. The control device 43 calculates the target value and estimated value of the blowout temperature based on the heat environmental information, adjusts the blast quantity of the cooling fan 30 in response to the difference of them, starts the distribution of the refrigerant with an aperture setting means when the estimated value becomes higher than the target value and the absolute value of the difference becomes the first set value in changing the heating operation to the cooling operation, and starts a blast when the absolute value of the difference becomes the second set value higher than the first set value. The blowout temperature can be lowered to the target value without stopping the compressor 31 under the environmental condition requiring frequent switching of cooling and heating.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat pump type air conditioner for a vehicle which air-conditions a passenger compartment.

[0002]

2. Description of the Related Art A refrigerant flow is reversed by a four-way valve during heating operation and during cooling operation, and an exterior heat exchanger (hereinafter referred to as an outdoor heat exchanger or an outdoor unit) is used as a heat absorber during heating operation. In addition, the vehicle interior heat exchanger (hereinafter referred to as indoor heat exchanger or indoor unit) is used as a radiator, and the outdoor unit is used as a radiator and the indoor unit is used as a heat absorber during cooling operation. A heat pump type air conditioner for a vehicle is known (for example, JP-A-2-
(See JP-A-290475). FIG. 12 shows the configuration of this type of vehicle heat pump type air conditioner.

During the heating operation, the four-way valve 2 is switched as shown by the solid line, and the refrigerant is compressor 1 → four-way valve 2 → first indoor heat exchanger 3 → heating heat exchanger 4 → second indoor heat exchanger 5 → It circulates in the path of expansion valve 6-> outdoor heat exchanger 7-> four-way valve 2-> receiver 8-> compressor 1. At this time, the heat of the high-temperature refrigerant discharged from the compressor 1 in the first indoor unit 3 is radiated to the air introduced by the blower fan 9 to generate warm air. Further, in the heat exchanger 4 for heating, the refrigerant whose temperature has dropped due to heat exchange in the first indoor unit 3 is heated by utilizing the waste heat from the engine 10 and sent to the second indoor unit 5. In the second indoor unit 5, the heat of the refrigerant heated by the heating heat exchanger 4 is transferred to the blower fan 11
Heat is dissipated to the air introduced by and hot air is created. On the other hand, in the outdoor unit 7, the refrigerant whose temperature has dropped due to heat exchange in the second indoor unit 5 absorbs the heat of the outside air introduced by the fan 12. That is, during the heating operation, the outdoor unit 7 is used as a heat absorber and the indoor units 3, 5 are used as radiators to generate warm air.

During cooling operation, the four-way valve 2 is switched as shown by the dotted line, and the refrigerant is compressed from the compressor 1 to the outdoor unit 7 to
The expansion valve 6 → the second indoor unit 5 → the first indoor unit 3 → the four-way valve 2 → the receiver 8 → the compressor 1 circulates in the flow path. At this time, in the outdoor unit 7, the heat of the high-temperature refrigerant discharged from the compressor 1 is radiated to the outside air, and in the first and second indoor units 3 and 5, the refrigerant whose heat is radiated by the outdoor unit 7 and whose temperature is lowered is blower fan. The heat of the air introduced by 9 and 11 is absorbed. That is, during the cooling operation, the outdoor unit 7 is used as a radiator and the indoor units 3 and 5 are used as heat absorbers to produce cold air.

Further, a heat dissipation auxiliary indoor heat exchanger (hereinafter referred to as an auxiliary heat radiator) is connected in parallel with a heat dissipation outdoor heat exchanger (hereinafter referred to as an outdoor unit) to a refrigeration cycle, and the auxiliary heat radiator is connected. For vehicles equipped with a control valve installed in the refrigeration cycle on the upstream side of the indoor heat exchanger for heat absorption of the air conditioning duct (hereinafter referred to as heat absorber), and which has a control valve that adjusts the flow rate distribution of the refrigerant to the outdoor unit and the auxiliary radiator. A heat pump type air conditioner is known (for example, see Japanese Patent Laid-Open No. 63-103727). FIG. 13 shows the configuration of this type of vehicle heat pump type air conditioner.

In summer, the heat absorber 21 is not likely to freeze during normal operation, so that no refrigerant flows to the auxiliary radiator 18,
Refrigerant is caused to flow in the path of the compressor 15 → the outdoor unit 17 → the liquid tank 19 → the expansion valve 20 → the heat absorber 21 → the compressor 15, and the air introduced by the blower fan 23 and passing through the heat absorber 21 is cooled. The cooled air is guided to the air mix door 24, the opening degree of the air mix door 24 is controlled, the air volume of the cooling air passing through the heater core 25 is adjusted, and the temperature is adjusted to a target air temperature.

On the other hand, when there is a possibility that the heat absorber 21 will freeze when the outside air temperature is low in winter or during air conditioning by internal air circulation, the control valve 16 is adjusted to adjust the compressor 15 →
Outdoor unit 17 → liquid tank 19 → expansion valve 20 → heat absorber 21 →
The first path of the compressor 15 and the compressor 15
→ Auxiliary radiator 18 → Liquid tank 19 → Expansion valve 20 → Heat absorber 21 → Compressor 15 flows the refrigerant through two paths, and the outdoor unit 17 and the auxiliary radiator 18 radiate heat. The air introduced by the blower fan 23 is warmed by the auxiliary radiator 18 and sent to the heat absorber 21, so that the heat absorber 21 does not freeze and is cooled by the heat absorber 21 to be sufficient even in winter. Dehumidification can be performed.

[0008]

In the former vehicle heat pump type cooling and heating apparatus described above, the flow of the refrigerant is reversed by the four-way valve 2 during the heating operation and the cooling operation, and the outdoor unit 7 is absorbed by the heat absorber during the heating operation. The indoor units 3 and 5 are used as radiators to generate warm air, and the outdoor unit 7 is used as a radiator during cooling operation, and the indoor units 3 and 5 are used as heat absorbers to generate cold air. There is. Therefore, if heating operation is performed under climatic conditions such as low outdoor temperature, rain or snow, the amount of heat absorbed by the outdoor unit 7 decreases, and assuming that the work of the compressor 1 is constant, The heat radiation amount in the indoor units 3, 5 that radiate the total heat amount of the heat absorption amount from 7 and the work amount of the compressor 1 is reduced, and the heating capacity is reduced. Moreover, under such a climatic condition, a frosting phenomenon is likely to occur, and the number of defrosting operations increases, which may make the heating operation unstable.

The outside temperature of the vehicle compartment (hereinafter referred to as the outside air temperature)
At an intermediate temperature of around 20 ° C, the operating efficiency of the refrigeration cycle is almost the maximum during both heating operation and cooling operation.
Even if the compressor 1 is operated at the lowest rotation speed, the capacity is still excessive, and the heating operation or the cooling operation must be performed while repeatedly stopping the operation of the refrigeration cycle. However, in the case of using an electric compressor, in order to reduce the starting torque and protect the compressor, it is necessary to hold the stopped state for several minutes after the compressor is once stopped to balance the low pressure and the high pressure of the refrigeration cycle. Further, when switching between the heating operation and the cooling operation, the flow direction of the refrigerant is reversed, so that the compressor must be stopped for several minutes in order to balance the pressure in the refrigeration cycle. In the case of a vehicle, if the compressor is stopped for a few minutes, the occupants will feel the change in the air temperature,
Depending on the switching between the heating operation and the cooling operation, the passenger compartment temperature (hereinafter referred to as the inside temperature) causes hunting, and the comfort feeling is impaired.

On the other hand, in the latter vehicle heat pump type cooling and heating apparatus described above, the auxiliary radiator 18 is provided upstream of the heat absorber 21.
If you install this, you can easily prevent fog of the window panel even at low outside air temperature and inside air circulation air conditioning, but to warm the cold air cooled by the heat absorber 21 to the target blowing air temperature, a heater that uses engine cooling water. It is not suitable for vehicles that do not have a large heat source, such as solar cars and electric vehicles, which require some kind of heating means such as electric heaters and electric heaters. Moreover, the amount of heat radiated from the auxiliary radiator 18 is absorbed by the downstream heat absorber 21, so that the auxiliary radiator 18 cannot radiate heat.

In order to solve such a problem, a control valve is provided on the discharge side of the compressor, and a heat radiating indoor heat exchanger is provided downstream of the heat absorbing indoor heat exchanger to enable dehumidification during heating operation. Has proposed a heat pump type cooling and heating device for a vehicle (Japanese Patent Application No. 3-345950). In this device, the cooling operation and the heating operation are switched at a temperature at which the boundary temperature at which window fogging does not occur due to the relationship between the inside air temperature and the outside air temperature and the target blow-out air temperature according to the thermal environment conditions substantially match. However, at the time of this switching, the operating efficiency of the refrigerating cycle becomes almost the maximum in both the cooling operation and the heating operation, so that even if the compressor is operated at the minimum rotation speed, it will be overcooled or overheated. Also, if only the air is blown with the compressor stopped, it will be difficult to maintain the anti-fog property of the window panel required for the vehicle, and as a result, the cooling operation and the heating operation will be switched alternately and the occupants will have a relatively short cycle. There is a problem that the occupant's feeling of comfort is impaired because the temperature must be adjusted while hunting the inside temperature around the set temperature.

An object of the present invention is to provide a heat pump type air conditioner for a vehicle, which keeps the sensible temperature of an occupant constant even under environmental conditions where the outside air temperature is around 20 ° C. and frequent switching between cooling operation and heating operation is required. To provide a device.

[0013]

The present invention will be described with reference to FIGS. 1 and 2 showing an embodiment. In the invention of claim 1, a compressor 31 for adding a work amount to a refrigerant, and a compressor 31 A heat exchanger 38 for radiating the heat of the discharged refrigerant to the outside air, and a heat radiating device that radiates the heat of the refrigerant discharged from the compressor 31 to the air blown by the first blowing means 37 to generate warm air The vehicle interior heat exchanger 33, the expansion means 34 connected to the refrigerant outflow side of the heat dissipation vehicle interior heat exchanger 33, the refrigerant outflow side of the expansion means 34 and the refrigerant intake side of the compressor 31,
A heat-absorbing passenger compartment heat exchanger 35 that absorbs the heat of the air blown by the first blower means 37 into the refrigerant to form cold air, and the refrigerant discharged from the compressor 31 provided on the refrigerant discharge side of the compressor 31. A heat pump type air conditioner for a vehicle equipped with a vehicle heat exchanger 38 and a heat dissipation vehicle interior heat exchanger 33, which can be distributed at an arbitrary ratio to a vehicle heat pump type air conditioner, based on thermal environment information. Blow-off air temperature calculating means 43 for calculating a target value of temperature, blow-out air temperature estimating means 43 for estimating a blow-out air temperature based on thermal environment information, and air blowing to the exterior heat exchanger 38 to increase the amount of heat radiation. Second blower means 30 for controlling the blower temperature, and the second blower means 3 according to the difference between the target value and the estimated value of the blown air temperature.
The air flow rate adjusting means 43 for adjusting the air flow rate of 0, and the refrigerant distribution ratio to the vehicle exterior heat exchanger 38 and the heat radiation vehicle interior heat exchanger 33 based on the difference between the target value and the estimated value of the blown air temperature. The opening degree setting means 43 that calculates and sets the opening degree of the refrigerant flow path switching means 32, and the estimated value of the blown-air temperature becomes higher than the target value when the heating operation state shifts to the cooling operation state. After the absolute value of the difference reaches the predetermined temperature T1, the opening degree setting means 43 starts the distribution of the refrigerant to the exterior heat exchanger 38, and the absolute value of the difference between the estimated value and the target value is the predetermined temperature. A control unit 43 is provided which starts blowing air to the vehicle exterior heat exchanger 38 by the air flow rate adjusting unit 43 after T2 (where T2> T1), thereby achieving the above object. In the vehicle heat pump type air conditioner according to claim 2, when the control unit 43 shifts from the cooling operation state to the heating operation state, the estimated value of the blown air temperature becomes lower than the target value, and the absolute value of the difference between them is smaller than the target value. Predetermined temperature T
Until the air flow rate adjusting means 43 reaches 3, the air flow to the exterior heat exchanger 38 is continued until the absolute value of the difference between the estimated value and the target value reaches a predetermined temperature T4 (where T4> T3). The opening degree setting means 43 is configured to continue the distribution of the refrigerant to the vehicle exterior heat exchanger 38. According to the invention of claim 3, a compressor 31 for adding a work amount to the refrigerant,
An exterior heat exchanger 38 for radiating the heat of the refrigerant discharged from the compressor 31 to the outside air, and a first blower 37
The heat-radiating vehicle interior heat exchanger 33 that radiates the heat of the refrigerant discharged from the compressor 31 to the air blown by to generate warm air, and is connected to the refrigerant outflow side of the heat-radiating vehicle interior heat exchanger 33. An expansion vehicle and an endothermic vehicle that is connected to the refrigerant outflow side of the expansion section 34 and the refrigerant intake side of the compressor 31, and absorbs the heat of the air blown by the first air blowing section 37 into the refrigerant to form cold air. The indoor heat exchanger 35,
A refrigerant flow path switching means 32 provided on the refrigerant discharge side of the compressor 31 and capable of distributing the refrigerant discharged from the compressor 31 to the exterior heat exchanger 38 and the heat dissipation interior heat exchanger 33 at an arbitrary ratio. A heat pump type air conditioner for a vehicle provided with the blown air temperature calculation means 43 for calculating a target value of the blown air temperature based on thermal environment information, a blown air temperature detection means for detecting the blown air temperature, and heat exchange outside the vehicle compartment. A second blower 30 for blowing air to the device 38 to increase the amount of heat radiation, and a blower for adjusting the blown amount of the second blower 30 according to the difference between the target value and the detected value of the blown air temperature. Based on the adjustment means 43 and the difference between the target value and the detected value of the blown air temperature, the refrigerant distribution ratio to the vehicle exterior heat exchanger 38 and the heat radiation vehicle interior heat exchanger 33 is calculated to perform the refrigerant flow path switching means 32. The opening of When the opening degree setting means 43 for setting the temperature is changed and the heating operation state is changed to the cooling operation state, the detected value of the blown air temperature becomes higher than the target value and the absolute value of the difference between them becomes the predetermined temperature T5. The distribution of the refrigerant to the exterior heat exchanger 38 is started by the opening degree setting means 43, and is sent after the absolute value of the difference between the detected value and the target value reaches a predetermined temperature T6 (where T6> T5). Control means 43 for starting air blowing to the exterior heat exchanger 38 by the air volume adjusting means 43
And to achieve the above object. Claim 4
In the vehicle heat pump type cooling and heating apparatus, when the control unit 43 shifts from the cooling operation state to the heating operation state, the detected value of the blown air temperature becomes lower than the target value, and the absolute value of the difference between them is a predetermined temperature. Until the temperature reaches T7, the air flow rate adjusting means 43 continues to blow air to the exterior heat exchanger 38 until the absolute value of the difference between the detected value and the target value reaches a predetermined temperature T8 (where T8> T7). Opening degree setting means 4
The distribution of the refrigerant to the vehicle exterior heat exchanger 38 is continued by the method described in No. 3. In the vehicle heat pump type air conditioner according to claim 5, when the distribution amount of the refrigerant to the heat radiating vehicle interior heat exchanger 33 is larger than that of the vehicle exterior heat exchanger 38, the air mix door opening degree provides a stable operation of the refrigeration cycle. The air-mix door opening control means 43 is provided to control the opening so that the minimum opening can be guaranteed. In the vehicle heat pump type cooling and heating apparatus according to the sixth aspect, the control means 43 causes the refrigerant flow path switching means 32 to distribute the refrigerant when the rotation speed of the compressor 31 is equal to or lower than a predetermined rotation speed. The heat pump type air conditioner for a vehicle according to claim 7,
The control unit 43 sets the air flow rate of the first air flow unit 37 to the minimum air flow rate when the refrigerant flow path switching unit 32 is distributing the refrigerant.

[0014]

In the vehicle heat pump type cooling and heating apparatus according to claim 1, when the heating operation state is changed to the cooling operation state,
After the estimated value of the blown air temperature becomes higher than the target value and the absolute value of the difference between them reaches a predetermined temperature T1, distribution of the refrigerant to the vehicle exterior heat exchanger 38 is started, and the target value of the blown air temperature becomes The refrigerant is distributed to the vehicle exterior heat exchanger 38 and the heat dissipation vehicle interior heat exchanger 33 in accordance with the distribution ratio calculated based on the estimated value. Furthermore, the absolute value of the difference between the estimated value of the blowing air temperature and the target value is the predetermined temperature T2 (however, T2
> T1), the air flow to the exterior heat exchanger 38 is started to increase the heat radiation amount, and thereafter, the air flow rate is adjusted according to the difference between the target value and the estimated value of the blowing air temperature. During normal heating operation, all the refrigerant discharged from the compressor 31 is radiated through the refrigerant flow path switching means 32 and the heat-radiating vehicle interior heat exchanger 3 is used.
3, the total of the input of the compressor 31 and the heat absorption amount of the heat absorbing vehicle interior heat exchanger 35 is radiated from the heat radiating vehicle interior heat exchanger 33. The estimated value of the blowing air temperature becomes higher than the target value, and the absolute value of the difference between them is the predetermined temperature T.
When it becomes 1, when the refrigerant is diverted to the vehicle exterior heat exchanger 38 by the refrigerant flow path switching means 32 while the second air blowing means 30 is stopped, the amount of heat radiated from the heat radiating vehicle interior heat exchanger 33 is reduced. Part of the heat is also radiated from the exterior heat exchanger 38. At this time, since the second blowing unit 30 is stopped, the heat of most of the refrigerant is not radiated from the exterior heat exchanger 38 as in the normal cooling operation. Moreover, since the high pressure of the refrigeration cycle is reduced by diverting the refrigerant to the vehicle exterior heat exchanger 38, the input of the compressor 31 is reduced and the heat radiation amount from the heat radiation vehicle interior heat exchanger 33 is reduced. Further, when the absolute value of the difference between the estimated value of the blown-air temperature and the target value reaches the predetermined temperature T2, if air is blown to the exterior heat exchanger 38 to increase the amount of heat radiation, the heat radiation vehicle The amount of heat released from the indoor heat exchanger 33 is further reduced.
That is, even under environmental conditions where the outside air temperature is around 20 ° C. and frequent switching between cooling operation and heating operation is required, the blowing air temperature can be reduced to the target value without stopping the compressor 31 in the heating operation state. You can In the vehicle heat pump type heating and cooling apparatus according to claim 2, when the cooling operation state is changed to the heating operation state, the estimated value of the blown air temperature becomes lower than the target value, and the absolute value of the difference between them reaches a predetermined temperature T3. Until the difference between the estimated value of the blown air temperature and the target value reaches a predetermined temperature T4 (where T4> T3), the heat exchanger 38 outside the vehicle interior continues. Continue to distribute refrigerant to. During the normal cooling operation, all the refrigerant discharged from the compressor 31 is sent to the vehicle exterior heat exchanger 38 via the refrigerant flow path switching means 32, and the input of the compressor 31 and the heat absorption amount of the heat absorbing vehicle interior heat exchanger 35 are exchanged. The total heat is radiated from the vehicle exterior heat exchanger 38 and the heat radiation vehicle interior heat exchanger 33. When the cooling operation state is changed to the heating operation state, the flow of the refrigerant to the vehicle exterior heat exchanger 38 and the air blown by the second air blower 30 are not suddenly stopped, and the estimated value of the blown air temperature is higher than the target value. Continues to be blown to the exterior heat exchanger 38 until the absolute value of the difference becomes a predetermined temperature T3, and the absolute value of the difference between the estimated value of the blown air temperature and the target value is a predetermined value. The distribution of the refrigerant to the exterior heat exchanger 38 is continued until the temperature reaches T4. As a result, heat is continuously radiated from the vehicle exterior heat exchanger 38 for a while after switching to the heating operation state, and all the heat of the refrigerant is radiated from the heat radiation vehicle interior heat exchanger 33 as in the normal heating operation state. Therefore, the amount of heat released from the heat-radiating vehicle interior heat exchanger 33 can be gradually increased. In other words, even under environmental conditions where the outside air temperature is around 20 ° C. and frequent switching between cooling operation and heating operation is required, the compressor 31 remains in the cooling operation state.
It is possible to raise the temperature of blown air to the target value without stopping. In the vehicle heat pump type cooling and heating apparatus according to claim 3, when the heating operation state is changed to the cooling operation state,
After the detected value of the blown-air temperature becomes higher than the target value and the difference between them reaches the predetermined temperature T5, the heat exchanger 38 outside the vehicle interior
Of the refrigerant to the outside heat exchanger 38 and the heat radiation passenger compartment heat exchanger 33 according to the distribution ratio calculated based on the target value and the detected value of the blown air temperature. . Further, after the difference between the detected value of the blown air temperature and the target value reaches a predetermined temperature T6 (where T6> T5), air blowing to the exterior heat exchanger 38 is started to increase the heat radiation amount, and thereafter. , The blow rate is adjusted according to the difference between the target value and the detected value of the blown air temperature. During normal heating operation, all the refrigerant discharged from the compressor 31 is sent to the heat radiation vehicle interior heat exchanger 33 via the refrigerant flow path switching means 32, and the heat input to the compressor 31 and the heat absorption quantity of the heat absorbing vehicle interior heat exchanger 35. Is radiated from the heat radiating vehicle interior heat exchanger 33. When the detected value of the blowing air temperature becomes higher than the target value and the absolute value of the difference between them reaches a predetermined temperature T5,
Refrigerant flow path switching means 3 with the second blowing means 30 stopped
When the refrigerant is diverted to the vehicle exterior heat exchanger 38 by 2, the part of the amount of heat radiated from the heat dissipation vehicle interior heat exchanger 33 is also radiated from the vehicle exterior heat exchanger 38. At this time, since the second blowing unit 30 is stopped, the heat of most of the refrigerant is not radiated from the exterior heat exchanger 38 as in the normal cooling operation. Moreover, since the high pressure of the refrigeration cycle is reduced by diverting the refrigerant to the vehicle exterior heat exchanger 38, the input of the compressor 31 is reduced and the heat radiation amount from the heat radiation vehicle interior heat exchanger 33 is reduced. further,
When the absolute value of the difference between the detected value of the blown-air temperature and the target value reaches a predetermined temperature T6, if air is blown to the heat exchanger 38 outside the vehicle to increase the amount of heat radiation, the heat inside the vehicle for heat radiation is released. The heat radiation amount from the exchanger 33 is further reduced. That is, even under environmental conditions where the outside air temperature is around 20 ° C. and frequent switching between cooling operation and heating operation is required, the blowing air temperature can be reduced to the target value without stopping the compressor 31 in the heating operation state. You can In the vehicle heat pump type cooling and heating apparatus according to claim 4, when the cooling operation state shifts to the heating operation state, the detected value of the blown air temperature becomes lower than the target value and the difference between them reaches a predetermined temperature T7. The ventilation to the outdoor heat exchanger 38 is continued, and further, until the difference between the detected value of the blown air temperature and the target value becomes equal to or higher than a predetermined temperature T8 (however, T8> T7), the outdoor heat exchanger 38 is supplied. Continue distribution of refrigerant. During normal cooling operation, all the refrigerant discharged from the compressor 31 is the refrigerant flow path switching means 3
2 is sent to the vehicle exterior heat exchanger 38, and the sum of the input of the compressor 31 and the heat absorption amount of the heat absorption vehicle interior heat exchanger 35 is the sum of the vehicle exterior heat exchanger 38 and the heat radiation vehicle interior heat exchanger 33.
Heat is radiated from. When shifting from the cooling operation state to the heating operation state, the flow of the refrigerant to the exterior heat exchanger 38 and the air blown by the second air blower 30 are not suddenly stopped, and the detected value of the blown air temperature is higher than the target value. Continues to be blown to the exterior heat exchanger 38 until the absolute value of the difference between them becomes a predetermined temperature T7, and the absolute value of the difference between the detected value of the blown air temperature and the target value is a predetermined value. The distribution of the refrigerant to the exterior heat exchanger 38 is continued until the temperature reaches T8.
As a result, heat is continuously radiated from the vehicle exterior heat exchanger 38 for a while after switching to the heating operation state, and all the heat of the refrigerant is radiated from the heat radiation vehicle interior heat exchanger 33 as in the normal heating operation state. Therefore, the amount of heat released from the heat-radiating vehicle interior heat exchanger 33 can be gradually increased. That is, even under an environmental condition where the outside air temperature is around 20 ° C. and it is frequently necessary to switch between the cooling operation and the heating operation, the blowing air temperature can be raised to the target value without stopping the compressor 31 in the cooling operation state. it can. In the vehicle heat pump type air conditioner according to claim 5, when the distribution amount of the refrigerant to the heat radiating vehicle interior heat exchanger 33 is larger than that of the vehicle exterior heat exchanger 38, the air mix door opening degree provides a stable operation of the refrigeration cycle. Control so that the minimum opening can be guaranteed. The heat exchanger 3 for radiating heat from the vehicle exterior heat exchanger 38
When the amount of refrigerant distributed to 3 is large and the air mix door control during cooling is performed to reduce the air mix door opening, the high pressure of the refrigeration cycle rises, and the compressor 31 is stopped to protect the refrigeration cycle. Will have to. Therefore, even in such a case, stable operation of the refrigerating cycle can be guaranteed by controlling the air mix door opening to be equal to or more than the minimum opening. In the vehicle heat pump type cooling and heating apparatus according to the sixth aspect, the refrigerant flow path switching means 32 distributes the refrigerant when the rotation speed of the compressor 31 is equal to or lower than a predetermined rotation speed. In the cooling operation state, when the estimated value or the detected value of the blowing air temperature is lower than the target value, the compressor 3 is used to reduce the cooling capacity.
Decrease the rotation speed of 1. Further, in the heating operation state, when the estimated value or the detected value of the blown air temperature is higher than the target value, the rotation speed of the compressor 31 is lowered in order to lower the heating capacity. However, when the rotation speed of the compressor 31 is lower than a predetermined rotation speed that is sufficiently low, it is difficult to set the temperature of the blown air to the target value simply by lowering the rotation speed of the compressor 31. Therefore, when the rotation speed of the compressor 31 is equal to or lower than the predetermined rotation speed,
By distributing the refrigerant to the vehicle exterior heat exchanger 38 and the heat dissipation vehicle interior heat exchanger 33, the temperature of the blown air can be raised to the target value in the cooling operation state, or can be lowered to the target value in the heating operation state. The outside temperature can be 20 ℃
It is possible to set the vehicle interior temperature to the target value even under environmental conditions in which switching between the front and rear cooling operation and the heating operation is frequently required. In the vehicle heat pump type cooling and heating apparatus according to the seventh aspect, the amount of air blown by the first air blower 37 is minimized when the refrigerant flow switching unit 32 is distributing the refrigerant. Under environmental conditions where the outside air temperature is around 20 ° C. and the switching between the cooling operation and the heating operation is frequently required, the refrigerant flow path switching means 32.
The vehicle exterior heat exchanger 38 and the heat radiation vehicle interior heat exchanger 33
In order to keep the vehicle interior temperature constant by distributing the refrigerant to the air conditioner, raising the blown air temperature to the target value in the cooling operation state, or lowering the blown air temperature to the target value in the heating operation state. The blowing air temperature fluctuates. At this time,
By setting the air flow rate of the first air blower 37 to the minimum air flow rate, the blown air does not directly hit the body of the occupant and is mixed with the surrounding air, so that the occupant directly feels the fluctuation of the blown air temperature. There is no such thing.

Incidentally, in the section of means and action for solving the above-mentioned problems for explaining the constitution of the present invention, the drawings of the embodiments are used in order to make the present invention easy to understand. It is not limited to.

[0016]

1 and 2 show the structure of an embodiment. The refrigeration cycle of this embodiment includes a compressor 31, a three-way valve 32, an outdoor heat exchanger (outdoor unit) 38, a check valve 70, a heat radiation indoor heat exchanger (radiator) 33, a liquid tank 36, an expansion valve 34, and An indoor heat exchanger for heat absorption (heat absorber) 35 is provided. The compressor 31 is an electric or hydraulic drive type compressor whose work can be controlled by a signal from the outside, and is provided outside the vehicle, for example, in the engine room. A three-way valve 32 is provided on the refrigerant discharge side of the compressor 31, and the three-way valve 32 switches whether the refrigerant discharged from the compressor 31 is guided to the outdoor unit 38 or bypasses the outdoor unit 38 and is guided to the radiator 33. .

In the following, the former refrigerant flow path through the outdoor unit 38 in the refrigeration cycle, that is, the compressor 31, the three-way valve 32, the outdoor unit 38, the check valve 70, and the radiator 3 will be described.
3-> liquid tank 36-> expansion valve 34-> heat absorber 35-> the flow path of the compressor 31 is called the first flow path, and the latter refrigerant flow path that bypasses the outdoor unit 38 in the refrigeration cycle, that is, the compressor 31-> three-way valve 32-> The flow path of the radiator 33 → the liquid tank 36 → the expansion valve 34 → the heat absorber 35 → the compressor 31 is called a second flow path. In this embodiment, the three-way valve 32 is controlled to switch to the first flow path during normal cooling operation, and to switch to the second flow path during normal heating operation.

The outdoor unit 38 radiates the heat of the high temperature refrigerant discharged from the compressor 31 to the outside air. Cooling fan 3
0 is for blowing air to the outdoor unit 38 to increase the amount of heat radiation, and the rotation speed is controlled by the control device 43 described later. The check valve 70 blocks the reverse flow of the refrigerant so that the refrigerant does not flow into the outdoor unit 38 during the heating operation by the second flow path. Further, the radiator 33 and the heat absorber 35 are provided in an air conditioning duct 39 arranged in the front part of the vehicle compartment such as the back side of the instrument panel, and the heat of the high-temperature refrigerant discharged from the compressor 31 by the radiator 33 is provided. Radiates heat to the air blown by the blower fan 37, and the heat absorber 35 causes the blower fan 37
The heat of the air blown by is absorbed by the refrigerant. further,
A liquid tank 36 is provided between the radiator 33 and the heat absorber 35.
An expansion valve 34 is installed, and a liquid tank 36 separates the gas and liquid of the refrigerant, and the expansion valve 34 adiabatically expands and liquefies the refrigerant that is compressed and liquefied by the compressor 31 to be vaporized. Therefore, the upstream side of the expansion valve 34, that is, the radiator 33 side is the high pressure side in this refrigeration cycle, and the downstream side of the expansion valve 34, that is, the heat absorber 35 side is the low pressure side.

On the upstream side of the duct 39, there are provided an inside air introduction port 40 for introducing air in the vehicle interior and an outside air introduction port 41 for introducing outside air in response to traveling wind pressure. An intake door 42 driven by the illustrated actuator is provided, and the inside air inlet 40 and the outside air inlet 4 are provided.
Open and close 1 with any ratio. The blower fan 37 installed upstream of the duct 39 is driven by a blower motor 44, introduces air from the inside air inlet 40 and the outside air inlet 41 according to the opening / closing ratio of the intake door 42, and is arranged downstream of the duct 39. Heat absorber 35 and radiator 3
Blow to 3.

An air mix door 46 is provided on the upstream side of the radiator 33. The air mix door 46 is opened and closed by an actuator (not shown) to adjust the ratio of the air passing through the radiator 33 and the air bypassing the radiator 33. The air absorbed by the heat absorber 35 and cooled is partly passed through the radiator 33 to be warmed according to the opening degree of the air mix door 46, and the rest bypasses the radiator 33 and is blown out as cold air. It That is, the ratio of cold air to warm air is adjusted according to the opening degree of the air mix door 46. The opening Xdsc of the air mix door 46 is the air mix door 46.
Is 0% (fully closed, Xdsc =
0), and at this time, the air volume distribution between cold air and warm air is 10
It will be 0%. On the other hand, the opening Xdsc when the air mix door 46 is at the position shown is 100% (fully open, Xdsc
= 100), and at this time, the air volume distribution between the cold air and the warm air is 100%.

An air mix chamber 47 is provided downstream of the air mix door 46 of the duct 39, where cold air and warm air are mixed to produce temperature-controlled conditioned air. Downstream of the air mix chamber 47, a ventilator outlet 51 that blows conditioned air toward the upper body of the occupant,
A foot outlet 52 that blows out the conditioned air toward the feet of the occupant and a defroster outlet 53 that blows out the conditioned air toward the windshield are installed, and the ventilator doors 55 and 53 are provided at the respective outlets 51 to 53.
A foot door 56 and a defroster door 57, and an actuator (not shown) that drives each door are provided. The ventilator outlet 51 has center vent outlets 51b and 51c at the center of the vehicle instrument.
Side vent outlets 51 on both sides of the instrument
a and 51d are provided.

Further, the duct 39 is provided with a recirculation duct 71 for recirculating air from the air mix chamber 47 to the inside air inlet 40. Air mix chamber 47
A recirculation door 74 is provided at the side air intake port 72, and the air intake port 72 is opened and closed by being driven by an actuator (not shown). That is, the amount of recirculated air is adjusted according to the opening degree of the recirculation door 74. Further, a switching door 75 is provided on the side of the inside air introduction port 40, and is driven by an actuator (not shown) to adjust the ratio between the recirculated air introduced into the air conditioning duct 39 and the inside air.

Various physical quantities used in this specification will now be defined. Tsuc; inlet air temperature of heat absorber 35 (detected by heat absorber inlet temperature sensor 58) Tout; outlet air temperature of heat absorber 35 (detected by heat absorber outlet temperature sensor 59) Tvsc; outlet air temperature of radiator 33 ( Temperature detected by radiator outlet temperature sensor 60) Tv; Temperature of blown air from ventilator outlet 51 Tamb; Air temperature outside the vehicle compartment (outside air temperature) (Detected by outside air temperature sensor 62) Tic; Air temperature inside vehicle (inside air temperature) ) (Detected by the room temperature sensor 63) Tptc; Set value of vehicle interior temperature (hereinafter referred to as set room temperature) (set by the room temperature setting device 64) Tof; Target blown air temperature Td of cooling and heating device; Refrigerant discharged from the compressor 31 Temperature (detected by a refrigerant heat detection sensor (not shown)) Qsun; (Detected by the sensor 61) Xdsc; Opening degree of air mix door 46 Xint; Opening degree of intake door 42 Hz; Frequency of compressor 31 (value proportional to rotation speed) Vfan; Voltage applied to blower motor 44

The control device 43 includes a microcomputer, a memory, an A / D converter, an actuator drive circuit,
The sensor 58 to 60, the room temperature setting device 64, the blowout port mode switch 65 for switching the blowout port, the blower fan switch 66, the blower motor 44, the cooling fan 30, which includes an interface circuit and the like.
Each door actuator, compressor 31, three-way valve 3
2 etc. are connected. The control device 43 executes a control program described later to control the air conditioning in the vehicle compartment. That is,
Tsuc, Tout, Tv from sensor and setting device
Xdsc, Wcomp, To based on thermal environment information such as sc, Tv, Qsun, Tamb, Tic, Tptc
The target cooling / heating conditions such as f are calculated, and the compressor 31, the blower motor 44, the cooling fan 30, the actuators of the respective doors, etc. are controlled so that the vehicle interior has the target cooling / heating conditions. In particular, in a state where the outside air temperature is around 20 ° C. where the cooling operation and the heating operation are frequently switched, the three-way valve 32
The cooling fan 30 controls the refrigerant flow path, and the cooling fan 30 adjusts the heat radiation amount of the outdoor unit 38 to perform air conditioning control so that the sensible temperature of the occupant does not change according to the switching of the air conditioning operation.

When the outside air temperature is about 20 ° C.
The air sucked by the heat absorber 35 is blown out into the passenger compartment with a temperature difference of about ± 5 ° C. according to the thermal environment conditions of the vehicle. As described above, the operating efficiency of the refrigeration cycle reaches almost the maximum when the outside air temperature is about 20 ° C., and therefore, if the cooling operation and the heating operation are simply performed alternately, the blown air temperature is greatly hunted and the occupant occupies. Makes you feel uncomfortable. Therefore, there is a need for a temperature control method that reduces the amount of heat released into the vehicle interior during heating and increases the amount of heat released into the vehicle interior during cooling.

In the heat pump type air conditioner for a vehicle of this embodiment, the following equation is established during the cooling operation and the heating operation.

## EQU00001 ## Qcond + Qsc = Qeva + Wcomp where Qcond: heat dissipation amount of the outdoor heat exchanger (outdoor unit) 38 Qsc; heat dissipation amount of the heat dissipation indoor heat exchanger (radiator) 33 Qeva; heat absorption indoor heat exchanger (heat absorption) Heat absorption amount of the air conditioner) Wcomp; Input of the compressor 31 Since the fluctuation of the heat load (temperature and humidity) of the air flowing into the heat absorber 35 during the steady operation is small, the right side of Expression 1 (Qeva
+ Wcomp) can be regarded as almost constant.

FIG. 3 shows the heat dissipation amount Qcond of the exterior heat exchanger and the heat dissipation interior heat exchanger of the three-way valve when the air mix door opening Xdsc is 100% during constant speed running. It is a figure which shows the ratio of the heat radiation amount Qsc. Here, the opening of the three-way valve 32 is 0% when all of the refrigerant discharged from the compressor 31 flows into the outdoor unit 38 (on the cooling side), and conversely, 100% when all the refrigerant discharged flows into the radiator 33. (Heating side) The opening degree of the three-way valve 32 is 10
In the case of 0%, all the heat quantity of (Qeva + Wcomp) is radiated from the radiator 33, and as the opening degree of the three-way valve 32 becomes smaller, the heat radiation quantity Qsc from the radiator 33 decreases and from the outdoor unit 38. Heat dissipation Qcond
Will increase. Here, the air mix door opening Xdsc
Is assumed to be 100%, the conditioned air is cooled by the heat absorber 35 and then warmed by the radiator 33, so that the three-way valve 3
Even if the opening degree of 2 becomes 0%, the heat radiation amount Qs from the radiator 33
c does not become 0.

The blown air temperature Tv of the ventilator 51 can be calculated by the following equation.

(2) Tv = Tsuc + Qsc / (ρair · Vai
r · Cpair) where, Tsuc: intake air temperature of the heat-absorbing passenger compartment heat exchanger 35 Qsc; heat radiation amount of the heat-dissipating passenger compartment heat exchanger 33 ρair; air density Vair; air volume Cpair; air specific heat

FIG. 4 shows the interior of the vehicle with respect to the opening of the three-way valve calculated by Equation 2 when the amount of heat released from the heat-radiating vehicle interior heat exchanger with respect to the opening of the three-way valve has a value as shown in FIG. Indicates the temperature of the blown air. In the figure, the blowing air temperature when the cooling fan 30 is ON and when it is OFF is shown. When the cooling fan 30 is operated, the heat radiation amount Qcond from the outdoor unit 38
While the amount Qsc of heat released from the radiator 33 decreases, the temperature Tv of the blown air decreases. In this way, by controlling the opening degree of the three-way valve 32 and the operation and stop of the cooling fan 30, the blowing air temperature Tv can be controlled in a wide range.
It becomes possible to adjust the temperature inside the vehicle while changing the temperature.

During normal heating operation, the compressor 3
The total of the input of 1 and the amount of heat absorbed by the heat absorber 35 is radiated from the radiator 33. Here, if the three-way valve 32 is switched and the refrigerant is made to flow to the outdoor unit 38 while the cooling fan 30 of the outdoor unit 38 is stopped, a part of the amount of heat radiated from the radiator 33 is also radiated from the outdoor unit 38. Become so. At this time, since the cooling fan 30 is stopped, most of the heat is not radiated from the outdoor unit 38 as in the normal cooling operation. Further, since the high pressure of the refrigeration cycle is lowered by flowing the refrigerant into the outdoor unit 38, the input of the compressor 31 is lowered and the amount of heat radiated from the radiator 33 is reduced. Furthermore, in the state where the flow of the refrigerant is the first flow path during the normal cooling operation,
When the cooling fan 30 of the outdoor unit 38 is switched from stop to low speed and further to high speed, the amount of heat radiation from the outdoor unit 38 gradually increases and the amount of heat radiation from the radiator 33 decreases, and the normal cooling operation is started.

On the other hand, during the normal cooling operation, the total of the input of the compressor 31 and the heat absorption of the heat absorber 35 is radiated from the outdoor unit 38 and the radiator 33. Radiator 33 during cooling
In order to increase the amount of heat released from the air mix door and raise the temperature of the blown air, the opening Xdsc of the air mix door 46 may be increased. Further, as the cooling fan 30 of the outdoor unit 38 is switched from high speed to low speed and then stopped, the amount of heat radiation from the outdoor unit 38 decreases, and conversely the amount of heat radiation from the radiator 33 increases. When the cooling fan 30 is stopped and the three-way valve 32 is switched to allow the refrigerant to flow through the second flow path, normal heating operation is performed. In this way, the three-way valve 3
The refrigerant flow path is switched by 2 and the operation speed of the cooling fan 30 of the outdoor unit 38 is switched, so that the compressor 3 can operate even in an intermediate temperature state of about 20 ° C.
It is possible to continue the air-conditioning operation without stopping No. 1 and easily lower the blown-air temperature to the target temperature during heating, or easily raise the blown-air temperature to the target temperature during cooling.

5 to 10 are flow charts showing the temperature control of the control unit 43. The operation of the embodiment will be described with reference to these flowcharts. When a main switch (not shown) of the cooling and heating device is turned on, the control device 43 starts the temperature adjustment control. In step S1, the room temperature Tptc and the inside air temperature Ti set by the above-mentioned sensor and operation member are set.
c, outside air temperature Tamb, heat absorber outlet air temperature Tout, heat absorber inlet air temperature Tsuc, blowing air temperature Tv, blower voltage Vfan, solar radiation amount Qsun, compressor discharge refrigerant temperature Td, compressor frequency Hz, air mix door opening Xdsc, etc. To detect. Step S2
Then, the target blowing air temperature Tof is calculated based on the detected sensor value, and the process proceeds to step S3 to set the blowing port mode according to the target blowing air temperature Tof. Here, VENT is a mode for blowing out the conditioned air from the ventilator outlet 51, and FOOT is a mode for blowing out the conditioned air from the foot outlet 52. Furthermore, B
/ L is a mode in which conditioned air is blown out from both the ventilator outlet 51 and the foot outlet 52.

Next, in step S4, the cooling operation or the heating operation is selected according to the target blown air temperature Tof. In this embodiment, the target blown air temperature Tof
Although the cooling operation or the heating operation is selected in accordance with the above, the cooling operation or the heating operation may be selected based on the temperature difference between the intake air temperature Tsuc of the heat absorber 35 and the target blowout air temperature Tof. . Alternatively,
The cooling operation or the heating operation may be selected based on the temperature difference between the target blown air temperature Tof and the temperature related to the fogging of the window panel. In step S5,
The intake door 42 according to the target blowing air temperature Tof
Calculate the opening degree of. Target airflow temperature Tof during cooling
When the target air temperature Tof is high or when the target air temperature Tof is high during heating, the intake door opening is reduced to reduce the amount of outside air taken in and the influence of the outside air temperature Tamb is reduced to achieve the target air temperature Tv. The wind temperature is brought close to Tof. On the contrary, in the state where the target blowing air temperature Tof is about 20 ° C. in the intermediate temperature state, the operation efficiency of the refrigeration cycle is high, so that even if a large amount of outside air is taken in, there is sufficient air conditioning capacity, and the opening degree of the intake door 42 is increased. Increase the intake of fresh air.

At step S6, the target blowing air temperature T
The blower voltage Vfan is set according to of. The blower voltage Vf is set when the target blowing air temperature Tof is high during heating or when the target blowing air temperature Tof is low during cooling.
Increase an to improve heating and cooling capabilities. On the other hand, 2
The blower voltage Vfan is set so that the amount of air flow is almost the minimum in the state of the intermediate temperature of about 0 ° C. In the state of the intermediate temperature of about 20 ° C., as described above, the switching of the refrigerant flow path by the three-way valve 32, the operation of the cooling fan 30 of the outdoor unit 38,
Since it is frequently stopped, the temperature Tv of the air blown into the passenger compartment
Fluctuation may increase. However, by making the blower voltage Vfan almost minimum, the blown air does not directly hit the body of the occupant and is mixed with the surrounding air, so that the occupant does not directly feel the fluctuation of the blown air temperature Tv. . In step S7, the estimated blown air temperature Tmix is calculated based on the air mix door opening Xdsc, the heat absorber outlet air temperature Tout, and the radiator outlet air temperature Tvsc. A temperature detection sensor may be provided downstream of the air mix chamber 47 or in the air outlets 51 to 53 to directly detect the temperature of the air blown. In step S8, the difference Δθ between the target blowing air temperature Tof and the estimated blowing air temperature Tmix is calculated, and the process proceeds to step S9 to determine the operation mode selected in the above step. When the cooling operation is selected, the process proceeds to step S10, and when the heating operation is selected, the process proceeds to step S20.

-Cooling operation-When the cooling operation is selected, the target blown air temperature Tof and the estimated blown air temperature Tmix are selected in step S10.
And the difference Δθ with respect to the predetermined values + S and −S. If the difference Δθ is smaller than the predetermined value −S, the process proceeds to step S11 to increase the frequency Hz of the compressor 31 by ΔHz, and the difference Δθ is larger than the predetermined value + S. In this case, the process proceeds to step S13 and the frequency Hz of the compressor 31 is decreased by ΔHz. When the difference Δθ is in the range of −S to + S, the compressor 31 is operated at the current frequency. That is,
When the estimated value Tmix of the blown air temperature is lower than the target value Tof, the operating speed of the compressor 31 is reduced to reduce the cooling capacity, and when the estimated value Tmix is higher than the target value Tof, the operating speed of the compressor 31 is increased. Increase cooling capacity. When the estimated value Tmix is substantially equal to the target value Tof, the operating speed of the compressor 31 is not changed.

In step S14, the compressor 31
It is determined whether the frequency Hz is lower than the preset frequency Hzset. As described above, when the estimated value Tmix of the blown air temperature is lower than the target value Tof, the operating frequency of the compressor 31 is lowered in order to reduce the cooling capacity. At this time, the current compressor frequency H
When z is equal to or higher than the set frequency Hzset, the estimated value Tmix of the blown air temperature can be brought close to the target value Tof by simply lowering the frequency Hz of the compressor 31. However, the current compressor frequency H
When z is lower than the set frequency Hzset, it is difficult to bring the temperature of the blown air to the target value Tof by merely lowering the compressor frequency Hz. Therefore, as described above, the refrigerant flow path is switched by the three-way valve 32. The operating speed of the cooling fan 30 is controlled to bring the temperature of the blown air close to the target value Tof.

The compressor frequency Hz is the set frequency H
If lower than zset, steps S15 to S17
At, the target value Tof of the blowing air temperature and the estimated value Tmi
When the difference Δθ from x is large, the opening control of the air mix door 46 during heating is performed even during the cooling operation, the three-way valve 32 is switched to the second flow path for heating, and the cooling fan 30 is further used. The temperature of the blown air is raised to the target temperature by stopping. When the difference Δθ is small, the cooling fan 30 is operated, the air-mix door control during cooling is performed by switching to the first flow path for cooling, and normal cooling operation is performed. In step S15, it is selected whether the air mix door control during cooling or the air mix door control during heating is performed based on the difference Δθ between the target value Tof of the blown air temperature and the estimated value Tmix. A hysteresis characteristic is provided for control switching of the air mix door 46. There is no problem if the air mix door control during heating is performed when the three-way valve 32 is switched to the first flow path for cooling, but when the air-mixing door control is switched to the second flow path for heating, When the air mix door control is performed, the opening degree of the air mix door becomes small, the high pressure of the refrigeration cycle rises, and the compressor 31 may have to be stopped in order to protect the refrigeration cycle. Therefore, in this embodiment, the air mix door control and the control of the three-way valve 32 are linked. That is, in step S16, when the air mix door control during heating is selected based on the difference Δθ between the target value Tof of the blowing air temperature and the estimated value Tmix, the three-way valve 32 is switched to the second flow path for heating. When the air mix door control during cooling is selected, the three-way valve 32 is switched to the first flow path for cooling. As a result, it is possible to prevent the opening of the air mix door from falling below the minimum opening that can guarantee stable operation of the refrigeration cycle.

In step S17, the cooling fan 30 is switched on or off based on the difference Δθ between the target value Tof of the blown air temperature and the estimated value Tmix. That is, when the difference Δθ is large, the cooling fan 30 is stopped, and when the difference Δθ is small, the cooling fan 30 is operated at the low speed Lo. A hysteresis characteristic is provided for the switching control of the operation and stop of the cooling fan 30. Switching point b of this hysteresis characteristic
1 and b2 are switching points a1 of the hysteresis characteristics of the control of the air mix door 46 and the three-way valve 32 described above.
The value is smaller than a2. Thus, as the estimated value Tmix of the blowing air temperature becomes higher than the target value Tof during the cooling operation and the difference Δθ (= Tof−Tmix) increases, the operating speed of the cooling fan 30 changes from high speed Hi to low speed Lo, and further While switching to the stop, the refrigerant flow path is switched from the cooling first flow path to the heating second flow path, whereby the blown-air temperature can be gradually brought close to the target value Tof.

The compressor frequency is the set frequency Hzs
If it is equal to or greater than et, normal cooling operation control is performed in steps S31 to S33. First, in step S31, the mix door 46 adjusts the ratio of cold air and warm air to control the temperature of blown air to the target value Tof. In the following step S32, the three-way valve 32 is switched to the first flow path for cooling, and the cooling fan 30 is operated in step S33.

-Heating operation-When the heating operation is selected, the difference Δθ between the target blown air temperature Tof and the estimated blown air temperature Tmix is compared with predetermined values + S and -S in step S20, and the difference Δθ is predetermined. If it is smaller than the value −S, the process proceeds to step S21, the frequency Hz of the compressor 31 is decreased by ΔHz, and the difference Δθ is obtained.
Is larger than the predetermined value + S, the process proceeds to step S23, and the frequency Hz of the compressor 31 is increased by ΔHz. When the difference Δθ is in the range of −S to + S, the compressor 31 is operated at the current frequency. That is, when the estimated value Tmix of the blowing air temperature is lower than the target value Tof, the operating speed of the compressor 31 is increased to increase the heating capacity, and when the estimated value Tmix is higher than the target value Tof, the operating speed of the compressor 31 is increased. Lower to reduce heating capacity. When the estimated value Tmix is substantially equal to the target value Tof, the operating speed of the compressor 31 is not changed.

In step S24, the compressor 31
It is determined whether the frequency Hz is lower than the preset frequency Hzset. As described above, when the estimated value Tmix of the blown air temperature is higher than the target value Tof, the operating frequency Hz of the compressor 31 is lowered to reduce the heating capacity. Therefore, when the current compressor frequency Hz is equal to or higher than the set frequency Hzset, the estimated value Tmix of the blown air temperature can be brought close to the target value Tof by simply lowering the frequency of the compressor 31. However, when the current compressor frequency Hz is lower than the set frequency Hzset, it is difficult to set the blowing air temperature to the target value Tof by merely lowering the compressor frequency Hz. While switching the refrigerant flow paths, the operating speed of the cooling fan 30 is controlled to bring the temperature of the blown air close to the target value Tof.

The compressor frequency Hz is the reference frequency H
If it is lower than zset, in steps S25 to S27, the target value Tof and the estimated value Tmi of the blowing air temperature are set.
When the difference Δθ from x is small, the opening degree of the air mix door 46 is controlled during cooling even during heating operation, the three-way valve 32 is switched to the first flow path for cooling, and the cooling fan 30 is further used. To lower the temperature of the blown air. When the difference Δθ is large, the cooling fan 30
Is stopped and the second flow path during heating is switched to perform air mix door control during heating to perform normal heating operation. In step S25, the target value T of the blowing air temperature
The air mix door control during heating or the air mix door control during cooling is selected based on the difference Δθ between the of and the estimated value Tmix. A hysteresis characteristic is provided for control switching of the air mix door 46. There is no problem if the air mix door control during heating is performed when the three-way valve 32 is switched to the first flow path for cooling, but when the air-mixing door control is switched to the second flow path for heating, If you do air mix door control,
There is a possibility that the opening degree of the air mix door becomes small and the high pressure of the refrigeration cycle rises, and the compressor 31 must be stopped in order to protect the refrigeration cycle. Therefore, in this embodiment, the air mix door control and the control of the three-way valve 32 are linked. That is, in step S26, when the air mix door control during cooling is selected based on the difference Δθ between the target value Tof of the blown air temperature and the estimated value Tmix, the three-way valve 32 is switched to the first flow path for cooling. When the air mix door control during heating is selected, the three-way valve 32 is switched to the second flow path for heating. As a result, the opening of the mix door can be prevented from becoming equal to or lower than the minimum opening that can guarantee stable operation of the refrigeration cycle.

In step S27, the operation of the cooling fan 30 is switched on and off based on the difference Δθ between the target value Tof and the estimated value Tmix of the blowing air temperature. That is, the difference Δθ
When is large, the cooling fan 30 is stopped, and when the difference Δθ is small, the cooling fan 30 is operated at low speed Lo. A hysteresis characteristic is provided for the switching control of the operation and stop of the cooling fan 30. Switching point d of this hysteresis characteristic
1, d2 are switching points c1 of the hysteresis characteristics of the control of the air mix door 46 and the three-way valve 32 described above,
The value is smaller than c2. Thus, as the estimated value Tmix of the blowing air temperature becomes lower than the target value Tof during the heating operation and the difference Δθ (= Tof−Tmix) becomes smaller, the operating speed of the cooling fan 30 is changed from the stop to the low speed Lo. It is possible to switch to the high speed Hi and also to switch the refrigerant channel from the second channel for heating to the first channel for cooling to gradually bring the blown-air temperature closer to the target value Tof.

The compressor frequency is the set frequency Hzs
If it is equal to or greater than et, normal heating operation control is performed in steps S34 to S36. First, in step S34, the mix door 46 adjusts the ratio of cold air and warm air, and controls the blown air temperature to be the target value Tof. In the following step S35, the three-way valve 32 is switched to the second flow path for heating, and in step S36, the cooling fan 30 is stopped.

FIG. 11 is a diagram showing the temperature control result of the embodiment at an outside air temperature of 20 ° C. This experiment is 2000cc
A heat pump type air conditioner for a vehicle of the embodiment was mounted on a class sedan vehicle. However, in this experiment, two electromagnetic valves were used instead of the three-way valve to switch between the first flow path for cooling and the second flow path for heating. In the figure, Pd is the discharge pressure of the compressor 31, Ps is the suction pressure of the compressor 31, Tfoot is the foot blowing air temperature, Tve.
nt is the vent blowing air temperature, and Tic is the inside air temperature.
As for environmental conditions, the outside air temperature was constant at 20 ° C, no solar radiation was applied for 25 minutes from the start, and solar radiation was applied for 25-60 minutes. The driving condition of the vehicle is from start to stop for 10 minutes,
40 km / h constant speed running for 10 to 38 minutes, 38 to 4
The vehicle was driven at a constant speed of 60 km / h for 8 minutes and stopped for 48 to 60 minutes. The set room temperature Tptc was set to 25 ° C. Immediately after the start of the operation of the cooling and heating device, the inside of the vehicle was in a condition of 20 ° C. and no sunlight, so the temperature control of the inside of the vehicle was started from the normal heating operation, but the cooling fan 30 was stopped at about 4 minutes. Temperature control for the intermediate temperature in the heating operation state in which the three-way valve is turned on / off has started. After that, when the vehicle shifts to the constant speed running of 40 km / h, the cooling fan 30
Even when the air conditioner is stopped, the amount of heat released from the outdoor unit 38 increases due to the influence of traveling wind, so the three-way valve is turned on / of.
The frequency of F is increasing. When solar radiation is applied from the state without solar radiation after 25 minutes have elapsed, temperature control is performed for the intermediate temperature for operating the cooling fan 30 in the first cooling air passage in the heating operation state that has been continued until then, and then the vehicle interior It will not be possible to reduce the temperature of the blown air to the target value,
At about 30 minutes, the heating operation state is switched to the cooling operation state, and the temperature control control for the intermediate temperature in the cooling operation state is performed. When in the heating operation state, the blowing air temperature was higher than the set room temperature Tptc in the bi-level blowing mode, but after shifting to the cooling operation state, the blowing air temperature was lower than the set room temperature Tptc in the vent blowing mode. . When the vehicle is stopped after 48 minutes have elapsed, the heat load on the vehicle increases. Therefore, the normal cooling operation is started after performing temperature control for the intermediate temperature several times. The experiment was conducted for 60 minutes by changing the amount of solar radiation and the vehicle speed, but the passenger compartment was maintained at a room temperature of 25 ° C set by the passengers. Thus, when the outside air temperature is around 20 ° C., the three-way valve 32 is opened at 0% and 1 degree regardless of the heating operation and the cooling operation.
Since the temperature of the passenger compartment is adjusted by alternately adjusting the temperature to 00%, the foot blowing air temperature Tfoot and the vent blowing air temperature T
Although the fluctuation of the vent is large, since the blower voltage Vfan is set to almost the minimum voltage, the conditioned air blown into the passenger compartment is mixed with the surrounding air before it reaches the passengers. The Tic becomes almost constant, and the passenger can maintain a comfortable state in the passenger compartment without feeling a change in the blown air temperature.

In the above embodiment, the three-way valve 32 switches the refrigerant flow path to either the first flow path or the second flow path, but instead of the three-way valve 32, the first flow path and the second flow path. A control valve or a solenoid valve that can adjust the flow rate distribution of the refrigerant to the continuous or multi-step may be used.

In the structure of the above embodiment, the compressor 31 is a compressor, the outdoor heat exchanger 38 is a vehicle exterior heat exchanger, and the blower fan 37 is a first blower.
The heat radiation indoor heat exchanger 33 is a heat radiation vehicle interior heat exchanger, the expansion valve 34 is an expansion means, the heat absorption indoor heat exchanger 35 is a heat absorption vehicle interior heat exchanger, and the three-way valve 32 is a refrigerant flow path switching. The control device 43 controls the blowing air temperature calculating means, the blowing air temperature estimating means, the blowing air amount adjusting means, the opening setting means, the control means and the air mix door opening control means, and the cooling fan 30 controls the second blowing means. Respectively.

[0048]

As described above, according to the invention of claim 1, when the heating operation state is changed to the cooling operation state, the estimated value of the blown air temperature becomes higher than the target value, and the absolute value of the difference therebetween is obtained. After the value reaches the predetermined temperature T1, the distribution of the refrigerant to the exterior heat exchanger is started, and the absolute value of the difference between the estimated value of the blown air temperature and the target value is the predetermined temperature T2.
Since the air blow to the exterior heat exchanger is started after (T2> T1), it is necessary to frequently switch between cooling operation and heating operation when the outside temperature is around 20 ° C. However, the blowing air temperature can be reduced to the target value without stopping the compressor in the heating operation state. According to the invention of claim 2, when the cooling operation state is changed to the heating operation state, the estimated value of the blown air temperature becomes lower than the target value and the absolute value of the difference between them reaches the predetermined temperature T3. Continue to blow air to the outdoor heat exchanger,
Further, since the distribution of the refrigerant to the exterior heat exchanger is continued until the difference between the estimated value of the blowing air temperature and the target value reaches the predetermined temperature T4 (where T4> T3), the outside air temperature is Even under the environmental conditions where it is necessary to frequently switch between the cooling operation and the heating operation at around 20 ° C., the blowing air temperature can be raised to the target value without stopping the compressor in the cooling operation state. According to the invention of claim 3, when the heating operation state is changed to the cooling operation state, the detected value of the blowing air temperature becomes higher than the target value and the difference between them becomes a predetermined temperature T5, and then the outside heat of the vehicle compartment is reached. The distribution of the refrigerant to the exchanger is started, and further, when the difference between the detected value of the blown air temperature and the target value reaches a predetermined temperature T6 (where T6> T5), the air is blown to the heat exchanger outside the vehicle compartment. Since it was started, even under environmental conditions where the outside air temperature is around 20 ° C and it is often necessary to switch between cooling operation and heating operation, the blowing air temperature can be set to the target value without stopping the compressor in the heating operation state. Can be lowered to. According to the invention of claim 4, when the cooling operation state is changed to the heating operation state, the heat exchange outside the vehicle is performed until the detected value of the blowing air temperature becomes lower than the target value and the difference between them reaches a predetermined temperature T7. Continues to blow air to the air conditioner, and continues to distribute refrigerant to the heat exchanger outside the vehicle until the difference between the detected value of the blown air temperature and the target value becomes equal to or higher than the predetermined temperature T8 (T8> T7). Therefore, even under environmental conditions where the outside air temperature is around 20 ° C and frequent switching between cooling operation and heating operation is required, the blowing air temperature can reach the target value without stopping the compressor in the cooling operation state. Can be raised. According to the invention of claim 5, when the distribution amount of the refrigerant to the heat radiating passenger compartment heat exchanger is larger than that to the passenger compartment heat exchanger, the air mix door opening degree is the minimum opening degree that can guarantee stable operation of the refrigeration cycle. Since the control is performed as described above, the outside temperature is 20
It is possible to guarantee stable operation of the refrigeration cycle even under environmental conditions in which switching between cooling operation and heating operation around ℃ is frequently required. According to the invention of claim 6, when the number of rotations of the compressor is equal to or lower than a predetermined number of rotations, the refrigerant flow passage switching means distributes the refrigerant, so that the temperature of the blown air can be raised to the target value in the cooling operation state. The temperature of the blown air can be lowered to the target value in the heating operation state, and the vehicle interior temperature can be set to the target value even under the environmental conditions where the outside air temperature is around 20 ° C and switching between the cooling operation and the heating operation is frequently required. Can be set. According to the invention of claim 7, the amount of air blown by the first air blower is minimized while the refrigerant is being distributed by the refrigerant flow path switching means.
Even if the air-conditioning operation and the heating operation are frequently switched at an intermediate temperature of around ℃, the blowing air directly mixes with the surrounding air without directly hitting the occupant's body. You don't feel it directly.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment.

FIG. 2 is a block diagram showing the configuration of one embodiment following FIG.

[Fig. 3] Constant speed running and air mixing door opening Xd
The figure which shows the ratio of the heat radiation amount Qcond of the vehicle exterior heat exchanger and the heat radiation amount Qsc of the heat radiation vehicle interior heat exchanger with respect to the opening degree of a three-way valve when sc is 100%.

FIG. 4 is a temperature of the air blown into the passenger compartment with respect to the opening of the three-way valve, which is calculated by Equation 2 when the amount of heat released from the heat-radiating passenger compartment heat exchanger with respect to the opening of the three-way valve has a value as shown in FIG. FIG.

FIG. 5 is a flowchart showing temperature control.

FIG. 6 is a flowchart showing temperature control control continued from FIG. 5;

FIG. 7 is a flowchart showing temperature control control continued from FIG. 6;

FIG. 8 is a flowchart showing temperature control control continued from FIG. 7.

9 is a flowchart showing temperature control control continued from FIG. 8;

FIG. 10 is a flowchart showing temperature control control continued from FIG. 9;

FIG. 11 is a diagram showing a temperature control result of the example at an outside air temperature of 20 ° C.

FIG. 12 is a block diagram showing a configuration of a conventional vehicle heat pump type air conditioner.

FIG. 13 is a block diagram showing the configuration of another conventional vehicle heat pump type air conditioner.

[Explanation of symbols]

 30 Cooling fan 31 Compressor 32 Three-way valve 33 Radiating indoor heat exchanger (radiator) 34 Expansion valve 35 Endothermic indoor heat exchanger (heat absorber) 36 Liquid tank 37 Blower fan 38 Outdoor heat exchanger (outdoor unit) 39 Duct 40 Inside Air Inlet 41 Outside Air Inlet 42 Intake Door 43 Control Device 44 Blower Motor 46 Air Mix Door 47 Air Mix Chamber 51 Ventilator Outlet 52 Foot Outlet 53 Defroster Outlet 55 Ventilator Door 56 Foot Door 57 Defroster Door 58 Heat Sink Inlet Temperature Sensor 59 Heat absorber outlet temperature sensor 60 Radiator outlet temperature sensor 61 Solar radiation sensor 62 Outside air temperature sensor 63 Room temperature sensor 64 Room temperature setting device 65 Outlet mode switch 66 Blower fan switch 70 check valve 71 re-circulation duct 72 air intake 74 recirculation door 75 switching door

Claims (7)

[Claims] 1. A compressor for adding work to a refrigerant, an exterior heat exchanger for radiating heat of the refrigerant discharged from the compressor to the outside air, and a compressor for discharging air blown by a first blowing means from the compressor. A heat radiation vehicle interior heat exchanger that radiates the heat of the generated refrigerant to generate warm air, an expansion means connected to the refrigerant outflow side of the heat radiation vehicle interior heat exchanger, and a refrigerant outflow side of the expansion means. An endothermic passenger compartment heat exchanger that is connected to the refrigerant suction side of the compressor and that absorbs the heat of the air blown by the first blower into the refrigerant to form cold air, and is provided on the refrigerant discharge side of the compressor. A heat pump type for a vehicle provided with a refrigerant flow path switching means capable of distributing the refrigerant discharged from the compressor to the vehicle exterior heat exchanger and the heat dissipation vehicle interior heat exchanger at an arbitrary ratio. A heating device, which includes a blowing air temperature calculating unit that calculates a target value of blowing air temperature based on thermal environment information, an blowing air temperature estimating unit that estimates a blowing air temperature based on thermal environment information, and the outside of the vehicle compartment. Second blowing means for blowing air to the heat exchanger to increase the amount of heat radiation, and adjusting the blowing quantity of the second blowing means according to the difference between the target value and the estimated value of the blowing air temperature. The air flow rate adjusting means, and calculates the refrigerant distribution ratio to the exterior heat exchanger and the heat dissipation vehicle interior heat exchanger based on the difference between the target value and the estimated value of the blown air temperature to calculate the refrigerant flow. The opening degree setting means for setting the opening degree of the path switching means and the estimated value of the blowing air temperature becomes higher than the target value when the heating operation state is changed to the cooling operation state, and the absolute value of the difference therebetween is Has it reached the predetermined temperature T1? Distribution of the refrigerant to the vehicle exterior heat exchanger is started by the opening degree setting means, and the absolute value of the difference between the estimated value and the target value reaches a predetermined temperature T2 (where T2> T1). To a control means for starting the air flow to the exterior heat exchanger from the vehicle by the air flow rate adjusting means from the heat pump type air conditioner for a vehicle. 2. The vehicle heat pump type cooling and heating apparatus according to claim 1, wherein the control unit causes the estimated value of the blown air temperature to be higher than the target value when the cooling operation state is changed to the heating operation state. Until the absolute value of the difference becomes a predetermined temperature T3, the air flow rate adjusting means continues to blow air to the exterior heat exchanger, and the absolute value of the difference between the estimated value and the target value is further increased. A heat pump type air conditioner for a vehicle, characterized in that the opening degree setting means continues to distribute the refrigerant to the outside heat exchanger until a predetermined temperature T4 (where T4> T3) is reached. 3. A compressor for adding work to the refrigerant, an exterior heat exchanger for radiating the heat of the refrigerant discharged from the compressor to the outside air, and a compressor for discharging the air blown by the first blowing means from the compressor. A heat radiation vehicle interior heat exchanger that radiates the heat of the generated refrigerant to generate warm air, an expansion means connected to the refrigerant outflow side of the heat radiation vehicle interior heat exchanger, and a refrigerant outflow side of the expansion means. An endothermic passenger compartment heat exchanger that is connected to the refrigerant suction side of the compressor and that absorbs the heat of the air blown by the first blower into the refrigerant to form cold air, and is provided on the refrigerant discharge side of the compressor. A heat pump type for a vehicle provided with a refrigerant flow path switching means capable of distributing the refrigerant discharged from the compressor to the vehicle exterior heat exchanger and the heat dissipation vehicle interior heat exchanger at an arbitrary ratio. A heating device, including a blowing air temperature calculating means for calculating a target value of the blowing air temperature based on thermal environment information, a blowing air temperature detecting means for detecting a blowing air temperature, and blowing air to the vehicle exterior heat exchanger. Second air blowing means for increasing the amount of heat radiation, and air blowing amount adjusting means for adjusting the air blowing amount of the second air blowing means according to the difference between the target value and the detected value of the air blowing air temperature, The opening of the refrigerant flow path switching means by calculating the refrigerant distribution ratio to the exterior heat exchanger and the heat dissipation interior heat exchanger based on the difference between the target value and the detected value of the blown air temperature. When the air-conditioning operation state is changed from the heating operation state to the cooling operation state, the detected value of the blowing air temperature becomes higher than the target value, and the absolute value of the difference between them becomes a predetermined temperature T5. The opening setting means The distribution of the refrigerant to the exterior heat exchanger is started, and the air flow rate adjustment is performed after the absolute value of the difference between the detected value and the target value reaches a predetermined temperature T6 (where T6> T5). A heat pump type cooling and heating apparatus for a vehicle, comprising: a control unit that starts blowing air to the vehicle exterior heat exchanger. 4. The vehicle heat pump type cooling and heating apparatus according to claim 3, wherein the control unit causes the detected value of the blowing air temperature to be higher than the target value when the cooling operation state shifts to the heating operation state. Until the absolute value of the difference becomes a predetermined temperature T7, the air flow rate adjusting means continues to blow air to the exterior heat exchanger, and the absolute value of the difference between the detected value and the target value is A heat pump type cooling and heating apparatus for a vehicle, wherein the opening degree setting means continues to distribute the refrigerant to the outside heat exchanger until a predetermined temperature T8 (where T8> T7) is reached. 5. The heat pump type air conditioner for a vehicle according to claim 1, wherein a distribution amount of the refrigerant to the heat radiating passenger compartment heat exchanger is larger than that of the vehicle exterior heat exchanger. At the same time, the heat pump type air conditioner for a vehicle is provided with an air mix door opening control means for controlling the air mix door opening so as to be equal to or more than the minimum opening that can guarantee stable operation of the refrigeration cycle. 6. The vehicle heat pump type cooling and heating apparatus according to claim 1, wherein the control unit controls the refrigerant flow path switching unit when the rotation speed of the compressor is equal to or lower than a predetermined rotation speed. A heat pump type air conditioner for a vehicle, characterized in that the refrigerant is distributed by means of. 7. The heat pump type cooling and heating apparatus for a vehicle according to claim 1, wherein the control unit is configured to perform the refrigerant flow distribution by the refrigerant flow path switching unit. A heat pump type air conditioner for a vehicle, characterized in that the amount of air blown by the air blower No. 1 is set to a minimum amount of air flow.