JP3166474B2 - Heat pump type air conditioner for vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat pump for a vehicle having a vapor compression refrigeration cycle for heating / cooling conditioned air by circulating refrigerant discharged from a compressor through a heat exchanger outside the vehicle compartment and a heat exchanger inside the vehicle compartment. The present invention relates to a heating and cooling system.

[0002]

2. Description of the Related Art A conventional heat pump type air conditioner for a vehicle is disclosed in Japanese Patent Application Laid-Open No. 2-290475. This cooling / heating device is provided with a vapor compression refrigeration cycle that circulates a refrigerant pumped by a compressor to a heat exchanger outside the vehicle compartment or a heat exchanger inside the vehicle, and controls the flow of the refrigerant with a four-way valve during heating operation and cooling operation. By using the heat exchanger outside, the heat exchanger outside the vehicle compartment is used as a heat sink during the heating operation, the heat exchanger inside the vehicle is used as the radiator, and the heat exchanger outside the vehicle compartment is used as the radiator during the cooling operation, Use the vehicle interior heat exchanger as a heat sink. In addition, this air conditioner has two heat exchangers inside the vehicle, and in a heating operation, heats the refrigerant pipe connecting the heat exchangers inside the vehicle with the waste heat of the engine, thereby heating the refrigerant, thereby increasing the heating performance. I try to improve.

In a heat pump type air conditioner for a vehicle disclosed in Japanese Patent Application Laid-Open No. 1-296056, heating is performed by a heat exchanger that absorbs heat from engine waste heat without using a heat exchanger outside the vehicle compartment during a heating operation. I have to.

However, in the former air conditioner, when the outside air temperature is low, such as during rainfall or snowfall, or when the vehicle is running, the amount of heat absorbed from the outside air by the outside heat exchanger in the vehicle interior heat exchanger is small and the temperature of the refrigerant is not so high. As a result, there is a problem that the amount of heat radiated by the heat exchanger inside the vehicle compartment is so small that satisfactory heating performance cannot be obtained. The former and latter air conditioners both use the waste heat of the engine to improve the heating performance.However, at the beginning of heating, the engine itself is cold, so there is almost no waste heat of the engine. Therefore, there was a problem in the initial heating performance.

[0005] In order to solve the above problems, the present applicant has proposed a heat pump type cooling and heating apparatus as described in Japanese Patent Application No. 3-345950. FIG. 11 shows a refrigeration cycle of this heat pump type cooling / heating device. In FIG. 11, during the cooling operation, the three-way valve 32 is switched to the solid line position, and the refrigerant discharged from the compressor 31 is discharged from the heat exchanger 38 outside the heat radiating compartment → the heat exchanger 33 inside the heat radiating car → the liquid tank 36 → the expansion valve. The heat circulates in the order of 34 → heat absorbing heat exchanger 35 → compressor 31, and the heat absorbing heat exchanger 35 absorbs the heat of the conditioned air into the refrigerant to produce cool air for cooling the vehicle interior. During the heating operation, the three-way valve 32 is switched to the position indicated by the dotted line, and the refrigerant discharged from the compressor 31 is discharged from the bypass pipe 150 to the heat exchanger 3 for heat radiation inside the vehicle.
3 → liquid tank 36 → expansion valve 34 → heat-absorbing vehicle interior heat exchanger 35 → compressor 31 circulates in this order, and heat-radiating vehicle interior heat exchanger 33 radiates the heat of the refrigerant to air-conditioned air for vehicle interior heating. Make warm air. In this manner, when the heating operation is performed, the refrigerant is bypassed to bypass the exterior heat exchanger 38 and the interior heat exchanger 35 is used as a heat absorber, and the exterior heat exchanger is used as a heat absorber as in the previous example. In this case, the amount of heat absorbed by the refrigerant can be increased even at a low outside air temperature as compared with the case where the temperature is low, and the heating performance can be improved.

[0006]

However, since the above-described exterior heat exchanger 38 is in direct contact with the outside air,
At a low outside air temperature, the temperature and pressure of the outside heat exchanger 38 are lower than those of other parts of the refrigeration cycle, so that the refrigerant enters the inside of the outside heat exchanger through the gap between the three-way valve 32 and the check valve 70. Flows, and the refrigerant stays in a liquid state, that is, so-called “cooling down of the refrigerant” easily occurs. For this reason, the refrigerant | coolant amount in the refrigeration cycle at the time of heating runs short, and the heating capacity may run short.

It is an object of the present invention to provide a heat pump type cooling / heating apparatus for a vehicle which can quickly return a refrigerant staying in a heat exchanger outside a vehicle compartment to a refrigeration cycle during heating.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1 showing an embodiment, the present invention is directed to an air-conditioning air generating means 37 for generating air-conditioning air to be blown into a vehicle cabin, and a compressor for pumping refrigerant. A refrigerant inflow side connected to the refrigerant discharge side of the compressor 31 and radiating heat of the refrigerant to the outside air; a refrigerant discharge side of the compressor 31 and a refrigerant outflow side of the heat exchanger 38 outside the vehicle interior; A refrigerant inflow side is connected to the heat radiation interior heat exchanger 33 that radiates heat of the refrigerant to the conditioned air to generate warm air, and a refrigerant inflow side is connected to the refrigerant outflow side of the heat radiation interior heat exchanger 33. Expansion means 34 for adiabatically expanding the refrigerant, and a refrigerant inflow side connected to the refrigerant outflow side of the expansion means 34 and a refrigerant outflow side connected to the refrigerant inflow side of the compressor 31, thereby dissipating the heat of the air-conditioned wind Exchange 38 and the heat-radiating inner heat exchanger 3
3, a heat-absorbing vehicle interior heat exchanger 35 which absorbs the refrigerant adiabatically expanded by the expansion means 34 through at least one of the expansion means 34 to generate cool air, and a refrigerant discharged from the compressor 31 at least during the cooling operation. During the heating operation, the refrigerant discharged from the compressor 31 is transferred to the outside heat exchanger 3.
The present invention is applied to a heat pump type cooling / heating device for a vehicle including refrigerant flow path switching means 100 and 101 for bypassing the heat exchanger 8 and leading to the heat exchanger 33 for heat dissipation. Then, a switching control means for controlling the refrigerant flow switching means so as to guide the refrigerant to the exterior heat exchanger 38 at the end of the heating operation is provided, thereby solving the above problem. The invention according to claim 2 is characterized in that, when the heating operation is performed between the operation of the vehicle and the stop thereof, the refrigerant flow switching means is configured to guide the refrigerant to the exterior heat exchanger in response to the compressor stop command. It is intended to be controlled. The invention according to claim 3 further comprises a detecting means for detecting a physical quantity related to the pressure or temperature of the high pressure system or the low pressure system of the refrigeration cycle, and heat exchange outside the vehicle compartment even when the detected physical quantity reaches a predetermined value or more. The refrigerant flow switching means is controlled to guide the refrigerant to the vessel. According to a fourth aspect of the invention, the refrigerant flow switching means is controlled so that the refrigerant is guided to the exterior heat exchanger for a predetermined time or a predetermined amount at the end of the heating operation. The invention of claim 5 is
When the refrigerant is guided to the outside heat exchanger under the control of the switching control means, the compressor further includes compressor control means for gradually reducing the refrigerant discharge amount of the compressor. According to a sixth aspect of the present invention, the amount of refrigerant discharged is reduced by gradually lowering the rotation speed or the discharge capacity of the compressor.

[0009]

According to the first aspect of the present invention, the refrigerant is guided to the exterior heat exchanger at the end of the heating operation. According to the second aspect of the invention, when the heating operation is performed during the period from the operation of the vehicle to the stop thereof, the refrigerant is guided to the exterior heat exchanger in response to the compressor stop command. According to the third aspect of the present invention, even when the physical quantity related to the pressure or temperature of the high pressure system or the low pressure system of the refrigeration cycle reaches a predetermined value or more, the refrigerant is guided to the exterior heat exchanger. In the invention according to claim 4, the refrigerant is guided to the exterior heat exchanger for a predetermined time or a predetermined amount at the end of the heating operation. According to the fifth aspect of the invention, when the refrigerant is guided to the exterior heat exchanger, the refrigerant discharge amount of the compressor is gradually reduced. According to the sixth aspect of the present invention, the refrigerant discharge amount is reduced by gradually decreasing the rotation speed or the discharge capacity of the compressor.

[0010] In the means and means for solving the above-mentioned problems which explain the constitution of the present invention, figures of some embodiments are used to make the present invention easy to understand. It is not limited to the embodiment.

[0011]

【Example】

(1) First embodiment (an embodiment corresponding to claims 1 to 3): One embodiment of the present invention will be described with reference to FIGS.
FIG. 1 shows a configuration of a vehicle heat pump type air conditioner according to the present invention, and the same components as those in FIG. 11 are denoted by the same reference numerals. The compressor 31 is installed at a location outside the vehicle compartment such as an engine room, and a compressor whose rotation speed can be changed, such as an electric compressor or a hydraulically driven compressor, is used. An external heat exchanger 38 is connected to the discharge side of the compressor 31 via a two-way valve 100 as a refrigerant flow switching means. The vehicle interior heat exchanger 33 is connected.

The outside heat exchanger 38 is provided outside the vehicle room such as an engine room, and is a vehicle outside condenser that radiates heat of the refrigerant discharged from the compressor 31 to the air to generate warm air. The heat-dissipating vehicle interior heat exchanger 33 is provided in a duct 39 arranged at the front of the vehicle interior, such as the back side of the instrument panel, and dissipates heat of the refrigerant discharged from the compressor 31 to the air. Is done.

The refrigerant inlet side pipe of the exterior heat exchanger 38 and the bypass pipe 15 for bypassing the exterior heat exchanger 38
0, a two-way valve 101 is interposed. The two-way valve 101 and the above-described two-way valve 100
It can be switched between an open position communicating the refrigerant inflow pipe of the heat exchanger 38 and the outside heat exchanger 38, and a closed position closing the same. During the heating operation, the two-way valve 100 is in the closed position,
Is switched to the open position, and at this time, the refrigerant discharged from the compressor 31 flows into the heat-dissipating interior heat exchanger 33 via the bypass pipe 150, that is, bypasses the exterior heat exchanger 38.

On the other hand, during the cooling operation, the two-way valve 100 is switched to the open position, and the two-way valve 101 is switched to the closed position.
At this time, the refrigerant discharged from the compressor 31 is guided to the exterior heat exchanger 38, and the refrigerant flowing out of the exterior heat exchanger 38 is guided to the heat radiation interior heat exchanger 33. Further, during the refrigerant recovery operation, both the two-way valves 100 and 101 are switched to the open position, and at this time, the heat refrigerant discharged from the compressor 31 flows to both the outside heat exchanger 38 and the bypass pipe 150. The heat refrigerant that has flowed into the exterior heat exchanger 38 evaporates the liquid refrigerant that is retained (sleeping) in the exterior heat exchanger 38 and is expelled to the outside of the exterior heat exchanger 38 to perform a heating operation cycle. To return to. The check valve 70 is for preventing the refrigerant from flowing backward from the heat-radiating interior heat exchanger 33 to the exterior heat exchanger 38.

The refrigerant outflow side of the heat exchanger 33 is connected to the refrigerant inflow side of the heat exchanger 35 through a liquid tank 36 and an expansion valve 34. The expansion valve 34 adiabatically expands the liquid refrigerant from the heat-dissipating vehicle interior heat exchanger 33 into mist and flows into the heat-absorbing vehicle interior heat exchanger 35. The heat absorbing passenger compartment heat exchanger 35 is an evaporator that absorbs the heat of the air passing therethrough into the refrigerant flowing from the expansion valve 34 to generate cool air. Heat-exchanger interior heat exchanger 3
5 is connected to the refrigerant inflow side of the compressor 31.

The air-conditioning duct 39 is provided with a blower fan 37 driven by a blower fan motor 44, and also has an inside air introduction pipe 40 for introducing vehicle interior air, and an outside air introduction pipe 41 for receiving outside air under running wind pressure. Is connected, and an intake door 42 is provided at a boundary between the outside air introduction pipe 41 and the air conditioning duct 39. Introductory tubes 40, 4
The outside air and inside air introduced from 1 are sent to the heat-absorbing vehicle interior heat exchanger 35 by a blower fan 37 and are cooled when passing through the heat exchanger 35.

In the air conditioning duct 39, an air mix door 46 is provided between the heat exchanger 33 for heat dissipation and the heat exchanger 35 for heat absorption. The air mixing door 46 is driven to open and close by an air mixing door actuator (not shown) driven by the control device 43, and the amount of air that is heated by passing through the heat exchanger 33 for heat dissipation and the heat exchanger 33. The blowing temperature is adjusted by adjusting the mixture ratio (air volume distribution) with the amount of air that has been bypassed and still cooled.

An air mixing chamber 47 is provided downstream of the heat-dissipating heat exchanger 33 of the air-conditioning duct 39 as a room for sufficiently mixing the cold air and the hot air to produce an air-conditioned air at an appropriate temperature. ing. Air mix chamber 47
Includes a ventilator outlet 51 for blowing conditioned air toward the upper body of the occupant, a foot outlet 52 for blowing conditioned air toward the feet of the occupant, and a defroster outlet for blowing conditioned air toward the front window. A ventilator door 55 for opening and closing the ventilator outlet 51 and a foot door 56 for opening and closing the foot outlet 52 are provided.
And a defroster door 5 for opening and closing the defroster outlet 53
7 are provided. The ventilator door 55, the foot door 56, and the defroster door 57 (hereinafter, collectively referred to as a mode door) are driven by a mode door actuator (not shown) driven by the control device 43.

A circulation passage 71 communicating with the inside air introduction pipe 40 is connected to the air mix chamber 47.
An opening 72 from the circulation passage 71 to the air mix chamber 47 is provided with an entrance door 74 of the circulation passage 71, and a branch 73 between the circulation passage 71 and the inside air introduction pipe 40 is provided with an exit door 75. Is provided. Entrance side door 74
The outlet door 75 is driven by an actuator (not shown) connected to the control device 43 to open and close the opening 72 and the branch 73, respectively. That is, the entrance side door 7
When the door 4 and the exit side door 75 are open, the temperature-controlled air circulates from the air mix chamber 47 to the upstream side of the blower fan 37.

The control device 43 includes a heat-absorbing vehicle interior heat exchanger suction air temperature sensor 58 for detecting a suction air temperature Tsuc of the heat-absorbing vehicle interior heat exchanger 35, and a heat-absorbing vehicle interior heat exchanger 3
And a ventilator outlet air temperature sensor 60 for detecting the outlet air temperature Tvent of the ventilator outlet 51 and the ventilator outlet air temperature sensor 60 for detecting the outlet air temperature Tout of the ventilator. A solar radiation sensor 61 for detecting the solar radiation Qsun to the outside, an outside air temperature sensor 62 for detecting the outside air temperature Tamb, and a room temperature sensor 63 for detecting the vehicle interior temperature Tic are connected. Each is entered.

The control device 43 includes an air conditioning setting panel 8.
9 is connected to a room temperature setting device 64, an air outlet mode switch 65, and a blower fan switch 66, and the operation position of a temperature setting lever (not shown) from the room temperature setting device 64 (depending on the set temperature Tptc). It is input to the control device 43. Here, as the outlet mode for blowing air into the passenger compartment, a vent mode for blowing air mainly to the upper body of the occupant, a foot mode for blowing air mainly to the feet of the occupant,
A bi-level mode for blowing air to both the upper body and the feet of the occupant can be set, and any of the modes can be selected by operating the outlet mode switch 65. The blower fan switch 66 is for selecting the air volume of the blower fan 37.

Further, the control device 43 includes a refrigerant temperature sensor 67 for detecting a refrigerant discharge temperature Td at the outlet side of the heat exchanger 33 and a blow-off air temperature Tv of the heat exchanger 33 for heat radiation. A heat-discharged vehicle interior heat exchanger outlet temperature sensor 68 is also connected.

The control device 43 includes the above-mentioned sensors 61 to 63
Target output temperature To on the basis of the detected output and the set temperature Tptc.
Is calculated, and based on the calculation result, the air mix door opening, the input value of the compressor 31, the blower fan air volume, the outlet mode, and the like are calculated. Then, the compressor 31, the blower fan 44, the air mix door actuator, the mode door actuator, and the like are driven and controlled based on the calculated values.

Further, the control device 43 determines whether or not warm-up control (rapid heating control at the beginning of heating) is performed based on the target blow-out temperature during the heating operation, and in the case of warm-up control, the target blow-out temperature To. Δθ1 is obtained from the temperature Tv and the outlet air temperature Tv of the heat-dissipating vehicle interior heat exchanger 33, and the set temperature Tset determined by the limit temperature at which the heat-absorbing vehicle interior heat exchanger 35 starts freezing and the heat-absorbing vehicle interior heat exchange. Δθ2 is obtained from the blow-out air temperature Tout of the heater 35,
Based on Δθ1 and Δθ2, the heat absorbing interior heat exchanger 3
5 is controlled so as to increase the compressor input while preventing freezing. Further, the control device 43 constitutes a switching control means,
As will be described in detail later, if the heating operation is performed when the outside air temperature is equal to or lower than a predetermined value, the refrigerant discharge temperature becomes equal to or higher than a predetermined value (after the refrigeration cycle satisfies predetermined conditions).
The refrigerant recovery operation is performed by switching the two-way valves 100 and 101, and thereafter the refrigerant recovery operation is periodically performed.

In the configuration of the above embodiment, the blower fan 37 functions as the air-conditioning air generating means, the expansion valve 34 functions as the expanding means,
The two-way valves 100 and 101 constitute refrigerant flow switching means, and the outside air temperature sensor 62 and the refrigerant temperature sensor 67 constitute detection means, respectively.

Next, the detailed procedure of the cooling / heating control by the control device 43 will be described with reference to the flowcharts of FIGS. In FIG. 2, first, in step S201, constants used in a comparison expression described later are set. Step S202
Then, various data are read. These data are
The operating position of the temperature setting lever, ie, the set temperature Tptc, the amount of solar radiation Qsun, the outside temperature Tamb, the set fan switch operation information Vfan-set, and the air conditioner switch on / off information A /
Csw, refrigerant discharge temperature Td, current operation mode judgment Ope-mod
e. Here, the current operation mode indicates a cooling operation, a heating operation, or a blowing operation.

In step S203, it is determined whether the air conditioner switch is on or off. If it is determined that the air conditioner switch is on, the process proceeds to step S204 to perform air conditioning control, and the position of the temperature setting lever is determined. As a result, if the set temperature lever is on the lower side of the set temperature, the cooling operation is performed in step S205, if it is on the higher side, the heating operation is performed in step S206, and if it is in the intermediate position, the air blowing operation is performed in step S207.

In the heating operation in step S206, the two-way valve 100 is switched to the closed position, and the two-way valve 101 is switched to the open position.
8 is led to the heat exchanger 33 for radiating heat inside the vehicle. Next, in step S208, it is determined whether or not the outside air temperature Tamb is equal to or lower than a predetermined temperature. If the outside air temperature Tamb is equal to or lower than the predetermined temperature, the process proceeds to step S209, and it is determined whether the refrigerant discharge temperature Td is equal to or higher than the predetermined temperature. If the refrigerant discharge temperature Td is equal to or higher than the predetermined temperature, the process proceeds to step S210 in FIG. That is, the condition that the outside air temperature Tamb is equal to or lower than the predetermined temperature is a condition in which the liquid refrigerant easily stays in the heat exchanger 38 outside the vehicle compartment. Therefore, it is determined that the condition for the refrigerant recovery operation has been satisfied, and the process proceeds to step S210.

In step S210, it is determined whether or not a predetermined time has already elapsed from the start of the cooling / heating device or from the previous cooling recovery operation. When step S210 is affirmed, the process proceeds to step S211 to determine whether or not the current refrigerant recovery operation has been performed for a preset time. If the current refrigerant recovery operation has not been started yet, or has been started but has not been performed for a predetermined time, step S211 is denied, and step S2 is performed.
Twelve refrigerant recovery operations are performed. Steps S210 to S21
By the control of 2, the refrigerant recovery operation can be performed at a predetermined cycle.

FIG. 5 shows the details of the refrigerant recovery operation. First, in step S212A, the two-way valves 100, 1
01 are both switched to the open position, that is, it is determined whether or not the refrigerant is flowing into the exterior heat exchanger 38. If step S212A is denied, that is, if the refrigerant recovery operation has not been performed yet, step S21
At 2B, both the two-way valves 100 and 101 are switched to the open position, and thereafter, the process returns to the processing of FIG. Step S2
If 12A is affirmative, that is, if the refrigerant recovery operation is being performed, step S121B is skipped and the process returns.

When the two-way valves 100 and 101 are switched to the open positions, most of the heat refrigerant having a temperature equal to or higher than the predetermined temperature discharged from the compressor 31 flows through the bypass pipe 150, but a part of the heat refrigerant flows outside the vehicle compartment. To the vessel 38. The heat refrigerant that has flowed into the exterior heat exchanger 38 evaporates the liquid refrigerant that is retained (sleeping) in the exterior heat exchanger 38 and is expelled to the outside of the exterior heat exchanger 38 to perform a heating operation cycle. To return to. Thereby, the heating capacity can be improved.

Thereafter, in step S213 of FIG. 3, the compressor 31 is controlled, in step S214 the blower fan 37 is controlled, and in step S215, the air mix door actuator, the outlet mode actuator and the suction port actuator are controlled to control the air flow. Controls mix door opening, outlet mode and inlet. Thereafter, the process returns to step S202 in FIG.

On the other hand, if it is determined in step S208 in FIG. 2 that the outside air temperature Tamb exceeds the predetermined value, the temperature and pressure of the outside heat exchanger 38 are high and the liquid refrigerant stays in the outside heat exchanger 38. Since it is not the condition to execute, step S210
The process skips steps S212 to S213. Further, even when the outside air temperature Tamb is equal to or lower than the predetermined value and the liquid refrigerant stays in the heat exchanger 38 outside the vehicle, it is determined in step S
If it is determined in 209 that the refrigerant discharge temperature Td is lower than the predetermined value, it is not possible to evaporate and expel the staying refrigerant, and in this case also, skip steps S210 to S212 and proceed to step S213.

In the cooling operation in step S205,
The two-way valve 100 is switched to the open position, and the two-way valve 101 is switched to the closed position, and all the refrigerant discharged from the compressor 31 is guided to the exterior heat exchanger 38. Next, steps S213 to S2
At 15, the compressor 31, the blower fan 37 and each door actuator are controlled. During the cooling operation, since the refrigerant always flows through the outside heat exchanger 38, the problem that the refrigerant stays in the outside heat exchanger 38 does not occur.
No refrigerant recovery operation is performed. Further, in the air blowing operation of step S207, both the two-way valves 100 and 101 are switched to the open position, that is, the position of the cooling recovery operation, and thereafter, while the compressor 31 is kept stopped, the steps S214 and S214 are performed.
At 215, the blower fan and each door actuator are controlled. In this case, the conditioned air from the blower fan 37 is blown into the vehicle compartment without adjusting the temperature. Further, if it is determined in step S203 that the air conditioner switch is off, the above-described actuators, blower fans, and compressors are stopped in steps S216 to S218 in FIG.

According to the above procedure, if the heating operation is performed when the outside air temperature Tamb is equal to or lower than the predetermined value, the operation is switched to the refrigerant recovery operation when the refrigerant discharge temperature Td becomes equal to or higher than the predetermined value. Later, the operation returns to the heating operation. Thereafter, the refrigerant recovery operation is periodically performed at predetermined time intervals. By performing the refrigerant recovery operation periodically as described above, it is possible to always exert a satisfactory heating capacity. That is, the first
Even after most of the refrigerant that has accumulated in the exterior heat exchanger 38 during the second refrigerant recovery operation is returned to the heating cycle, the refrigerant is gradually removed from the gap between the two-way valve 100 and the check valve 70 little by little. It may flow into the outdoor heat exchanger 38 and stay in a liquid state. However, if the refrigerant recovery operation is performed periodically as described above, the liquid refrigerant in the exterior heat exchanger 38 can be returned to the refrigeration cycle during the heating operation each time. The amount of refrigerant in the inside can always be maintained at a predetermined amount or more, and satisfactory heating performance can always be obtained. In the above control, steps S208 to S212 performed by the control device 43 correspond to switching control means.

FIGS. 6A and 6B show experimental data during the heating operation by the present inventors. FIG. 6A shows the rotational speed of the compressor and the refrigerant discharge temperature, and FIG. . This data indicates that the outside air temperature is between 0 and
It is a value at 2 ° C., that is, under conditions where the liquid refrigerant easily stays in the heat exchanger 38 outside the vehicle compartment. In this example, after the start of the heating operation, when the refrigerant discharge temperature reaches 60 ° C., the first refrigerant recovery operation is performed only for 30 seconds, and thereafter, the refrigerant recovery operation is periodically performed every 10 minutes for 30 seconds. Will be As a result of the refrigerant recovery operation, the liquid refrigerant remaining in the exterior heat exchanger 38 is gradually vaporized, and the pressure in the exterior heat exchanger 38 is increased. Is discharged from Therefore, even after the refrigerant recovery operation, an appropriate amount of refrigerant circulates on the cycle side during heating, and heating performance can be sufficiently exhibited. Note that the refrigerant of an appropriate amount or more is stored in the liquid tank 36 or an accumulator (not shown) (usually arranged on the refrigerant suction side of the compressor 31).
It is the same as in a general refrigeration cycle that the refrigerant circulation amount in the cycle is properly maintained. Above, 3 every 10 minutes
Although the example in which the refrigerant recovery operation is performed for 0 seconds has been described, the time interval and the refrigerant recovery operation time can be appropriately selected. For example, the longer the outdoor air temperature, the longer the refrigerant recovery operation time interval, and the longer the refrigerant recovery operation time. It may be shorter. If the heating performance decreases during the refrigerant recovery operation, for example, the rotation speed of the compressor 31 may be increased to improve the refrigeration capacity and maintain the heating performance.

(2) Second Embodiment (Embodiment Corresponding to Claims 4 to 9): Next, the second embodiment of the present invention will be described with reference to FIGS.
An example will be described. In this embodiment, the compressor 31
Is performed, the refrigerant recovery operation is also performed.

In step S301 of FIG. 7, constants used in the comparison expression are set, and in step S302,
Read various information. The information to be read is the information described in step S202 of FIG. 2 and the on / off state Ign of the ignition key. In step S303, it is determined whether or not the ignition key has just been switched from on to off (compressor stop command has been issued). If the result is affirmative, the process proceeds to step S323 in FIG. Step S323
Then, each actuator such as a mode actuator and an air mix door actuator is stopped.

In step S324, it is determined whether or not the cooling operation has been performed during the current operation of the cooling and heating apparatus. This can be determined by storing the fact that the cooling operation has been performed using a flag or the like. If the cooling operation is not being performed, a refrigerant recovery operation is performed in step S325. According to this, the refrigerant recovery operation is performed when the ignition key is turned off during the heating operation, or when the ignition key is turned off during the blowing operation after switching to the air blowing operation after the heating operation. The details of the refrigerant recovery operation are the same as the processing shown in FIG. By performing the refrigerant recovery operation when the ignition key is turned off, the refrigerant in the exterior heat exchanger 38 can be returned to the cycle during the heating operation, and the refrigerant retention amount in the exterior heat exchanger 38 at the next heating time Can be reduced to a minimum.

On the other hand, if it is determined in step S324 that the cooling operation has been performed, the flow proceeds to step S326, skipping the refrigerant recovery operation in step S325. That is, the fact that the cooling operation is performed means that the refrigerant has circulated through the exterior heat exchanger 38, and in this case, the amount of the refrigerant retained in the exterior heat exchanger 38 is considered to be extremely small. Therefore, the refrigerant recovery operation is not performed.

In steps S326 and S327, the blower fan 37 and the compressor 31 are stopped. When the compressor is stopped, the rotational speed of the compressor 31 is gradually reduced, so that the refrigerant discharge amount is gradually reduced. According to this, when the refrigerant recovery operation is performed in step S325, the heat refrigerant can be guided to the exterior heat exchanger 38 by a predetermined amount, and the compressor 3
The driver does not feel uncomfortable due to the sudden stop of the vehicle. In step S328, it is determined whether or not the ignition key is off. If it is on, the process returns to step S302. If it is off, the vehicle is stopped in step S329 and the process ends.

On the other hand, if step S303 in FIG. 9 is denied, the process proceeds to step S304. Step S30
The processing in steps S203 to S316
215 is the same as the process. That is, also in the present embodiment, if the heating operation is performed when the outside air temperature Tamb is equal to or lower than the predetermined value, the operation is switched to the refrigerant recovery operation when the refrigerant discharge temperature Td becomes equal to or higher than the predetermined value, and the heating operation is performed after a predetermined time has elapsed. Return to Thereafter, the refrigerant recovery operation is periodically performed at predetermined time intervals. Therefore, as described above, the amount of refrigerant in the refrigeration cycle during heating can always be maintained at a predetermined amount or more, and satisfactory heating performance can always be obtained.

When the air blowing operation is performed in step S308, the process proceeds to step S317 in FIG. 9 to determine whether or not the air conditioner has just changed from the heating operation to the air blowing operation. Step S31
If the result is negative, the process proceeds to step S315, and if the result is positive, the process proceeds to step S313. That is, the refrigerant recovery operation is performed immediately after the operation is changed from the heating operation to the blow operation (immediately after the stop of the compressor is instructed). As a result, the refrigerant in the exterior heat exchanger 38 can be returned to the cycle during the heating operation, and the amount of refrigerant retained in the exterior heat exchanger 38 during the next heating can be reduced to a minimum.

If it is determined in step S304 that the air conditioner switch is off, the flow advances to step S323 in FIG. That is, even when the air conditioner switch is switched from ON to OFF (compressor stop command is output), the refrigerant recovery operation is performed unless the cooling operation is performed, and the outside heat of the vehicle at the next heating is performed as described above. The amount of refrigerant retained in the exchanger 38 can be reduced to a minimum.

FIGS. 10A and 10B show experimental data during the heating operation by the present inventors. FIG. 10A shows the rotational speed of the compressor and the refrigerant discharge temperature, and FIG. . This data also shows that the outside air temperature is 0 ~ 2 ℃
, That is, under the condition that the liquid refrigerant easily stays in the vehicle exterior heat exchanger 38. In this example, about 3 hours after the start of the experiment
The refrigerant recovery operation is performed in one minute, and when the ignition key is turned off after a lapse of 40 minutes, the refrigerant recovery operation is performed.
At that time, the compressor rotation speed, that is, the refrigerant discharge amount gradually decreases, and the compressor 31 stops around 43 minutes. When the ignition key is turned off in this way, a refrigerant recovery operation for flowing the refrigerant into the outside heat exchanger 38 is performed. As a result, the temperature of the liquid refrigerant in the heat exchanger 38 outside the vehicle compartment rises,
The gas is vaporized by the increase in the pressure, and is mostly discharged from the heat exchanger 38 outside the vehicle compartment. If the refrigerant recovery operation is performed at the end of the operation as described above, the refrigerant recovery operation can be performed without affecting the heating performance at all, so that the refrigerant recovery operation can be performed very effectively. However, since the refrigeration cycle operates even after the end of the operation, it is necessary to quickly reduce the compressor speed as shown in FIG. 10 so that the occupant does not feel uncomfortable.

The time and cycle of the refrigerant recovery operation can be variously changed according to the thermal environment in the vehicle compartment and the state of the refrigeration cycle. For example, the second and subsequent refrigerant recovery operation times after the start of the heating operation may be shorter than the first recovery operation time, or may be shorter as the refrigerant discharge temperature is higher. Alternatively, after the refrigerant recovery operation is performed a predetermined number of times, no more is performed, or after the refrigerant recovery operation is performed a predetermined number of times, the cycle of the refrigerant recovery operation is increased, or the discharge temperature and the vehicle The refrigerant recovery operation time may be set according to the temperature difference of the outdoor heat exchanger. Further, whether or not to perform the first refrigerant recovery operation after the start of the heating operation is determined based on the refrigerant discharge temperature Td of the heat-radiating vehicle interior heat exchanger 33, that is, the temperature of the high-pressure system of the refrigeration cycle. For example, the heat absorbing vehicle interior heat exchanger 35
The determination may be made based on the temperature of the low-pressure system such as the refrigerant discharge temperature. Alternatively, the determination may be made based on the refrigerant discharge pressure instead of the refrigerant discharge temperature.

According to the first aspect of the present invention, the refrigerant is guided to the exterior heat exchanger at the end of the heating operation, so that the amount of refrigerant retained in the exterior heat exchanger during the next heating operation is reduced to a minimum. be able to. At the end of heating operation,
Normally, since the refrigeration cycle is at high temperature and high pressure, the heat refrigerant that has accumulated in the exterior heat exchanger can be reliably returned to the heating operation cycle. According to the second aspect of the present invention, when the heating operation is performed during the period from the operation of the vehicle to the stop thereof, that is, when there is a possibility that the refrigerant may remain in the heat exchanger outside the vehicle, the compressor stop instruction is issued. The refrigerant was guided to the heat exchanger outside the vehicle in response to
The accumulated refrigerant can be returned to the cycle during the heating operation, and the amount of refrigerant accumulated in the exterior heat exchanger during the next heating operation can be reduced to a minimum. According to the third aspect of the present invention, even when the physical quantity related to the pressure or the temperature of the high-pressure system or the low-pressure system of the refrigeration cycle reaches a predetermined value or more, the refrigerant is guided to the exterior heat exchanger. Evaporation of the heat refrigerant retained in the outdoor heat exchanger is promoted, and this can be reliably returned to the cycle during the heating operation. In addition, when the physical quantity is equal to or more than the predetermined value, a sufficient heating capacity is obtained, so that a decrease in the heating performance due to the heat of the refrigerant being radiated to the outside air by the heat exchanger outside the vehicle compartment is suppressed to a minimum. it can. According to the invention of claim 4,
Since the refrigerant is guided to the exterior heat exchanger for a predetermined time or a predetermined amount at the end of the heating operation, the amount of heat released to the outside air in the exterior heat exchanger can be suppressed to a minimum.
A decrease in heating performance can be suppressed. According to the fifth and sixth aspects of the present invention, when the refrigerant is introduced into the exterior heat exchanger at the end of the heating operation, the refrigerant discharge amount of the compressor is gradually reduced. Will not be given to the crew.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of a vehicle heat pump type air conditioner according to the present invention.

FIG. 2 is a flowchart for explaining the operation of the first embodiment.

FIG. 3 is a flowchart following FIG. 2;

FIG. 4 is a flowchart following FIG. 2;

FIG. 5 is a flowchart showing details of a refrigerant recovery operation.

FIG. 6 is a view showing experimental data in the first embodiment.

FIG. 7 is a flowchart illustrating the operation of the second embodiment.

FIG. 8 is a flowchart following FIG. 7;

FIG. 9 is a flowchart following FIG. 7;

FIG. 10 is a view showing experimental data in the second embodiment.

FIG. 11 is a diagram showing a configuration of a refrigeration cycle of a conventional vehicle heat pump air conditioner.

[Explanation of symbols]

REFERENCE SIGNS LIST 31 compressor 33 heat-dissipating vehicle interior heat exchanger 34 expansion valve (expansion means) 35 heat-absorbing vehicle interior heat exchanger 37 blower fan (air-conditioning wind generating means) 38 vehicle exterior heat exchanger 43 control device (switch control means, compressor control) Means) 44 Blower fan motor 46 Air mix door 51 Ventilator outlet 52 Foot outlet 53 Defroster outlet 61 Solar radiation sensor 62 Outside air temperature sensor (detection means) 63 Room temperature sensor 67 Refrigerant temperature sensor (detection means) 100, 101 Two-way valve (Refrigerant channel switching means)

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B60H 1/22 B60H 1/32

Claims (6)

(57) [Claims] And conditioned air generating means for 1. A generating conditioned air to be blown into the passenger compartment, a compressor for pumping refrigerant, the refrigerant inflow side is connected to the refrigerant discharge side of the compressor, for radiating heat of the refrigerant to the outside air An exterior heat exchanger, a refrigerant inflow side connected to a refrigerant discharge side of the compressor and a refrigerant outflow side of the exterior heat exchanger, and radiating heat of the refrigerant to the conditioned air to generate warm air. A heat exchanger; a refrigerant inflow side connected to the refrigerant outflow side of the heat-dissipating vehicle interior heat exchanger; expansion means for adiabatically expanding the refrigerant; and a refrigerant inflow side connected to the refrigerant outflow side of the expansion means; The refrigerant outflow side is connected to the refrigerant inflow side of the compressor, and the heat of the conditioned air is adiabatically expanded by the expansion means through at least one of the exterior heat exchanger and the heat radiation interior heat exchanger. A heat absorbing vehicle interior heat exchanger that absorbs heat into the refrigerant to produce cool air; and, during cooling operation, guides refrigerant discharged from the compressor to at least the vehicle exterior heat exchanger. During heating operation, discharges refrigerant from the compressor to the vehicle exterior heat exchanger. A heat pump type cooling / heating device for a vehicle, comprising: a refrigerant flow path switching unit that bypasses an exchanger and guides the refrigerant to the heat-radiating vehicle interior heat exchanger, wherein the refrigerant is guided to the vehicle exterior heat exchanger at the end of the heating operation. A heat pump type cooling and heating device for a vehicle, comprising a switching control means for controlling a refrigerant flow switching means. 2. The switching control means according to claim 1, wherein said switching control means guides refrigerant to said heat exchanger outside said vehicle in response to a command to stop the compressor when said heating operation is performed during a period from a start of operation of said vehicle to a stop of said vehicle. The vehicle heat pump type cooling and heating apparatus according to claim 1 , wherein the refrigerant flow switching means is controlled. 3. A refrigeration cycle further comprising a detecting means for detecting a physical quantity related to a pressure or a temperature of a high-pressure system or a low-pressure system of the refrigeration cycle, wherein the switching control means determines that the detected physical quantity has reached a predetermined value or more. and controlling the refrigerant flow path switching means to direct coolant to the vehicle exterior heat exchanger also 請
The vehicle heat pump air conditioner according to claim 1 . Wherein said switching control means, claims, characterized in that to control the refrigerant flow path switching means so that the refrigerant during the heating operation ends is led to the outer heat exchanger for a predetermined time or a predetermined amount 2. The heat pump type cooling and heating device for vehicles according to 1 . Wherein when the refrigerant in the vehicle exterior heat exchanger by the control of the switching control means is guided, according to claim 1, further comprising a compressor control means for gradually decreasing the refrigerant discharge amount of the compressor 4. The heat pump type cooling / heating device for vehicles according to item 1. Wherein said compressor controlling means, wherein, characterized in that reducing the refrigerant discharge amount by lowering gradually the rotational speed or the discharge capacity of the compressor
Item 6. A heat pump air conditioner for vehicles according to item 5 .