JP2009202735A - Air conditioning device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air conditioning device for a vehicle that executes control for satisfying both of a desired blowing-out temperature and desired dehumidification performance when ventilation air is heated by a heating means other than a refrigerating cycle in dehumidification operation. <P>SOLUTION: The air conditioning device for a vehicle is provided with a control device 50 that controls operation of a heat-pump refrigerating cycle 20, an opening degree of an air mix door 8, and conduction of a PTC heater 40 so as to control a blowing-out temperature before ventilation air inside an air conditioning case 1 is blown out into a vehicle cabin. When the control device 50 determines that the actually-measured blowing-out temperature is higher than a prescribed value during dehumidification heating cycle operation, the control device switches from the dehumidification heating cycle operation to cooling cycle operation, and further, supplies power to the PTC heater 40. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicle air conditioner that performs heating and air conditioning in a passenger compartment by operating a heat pump refrigeration cycle and using heat generated from an engine or a battery.

As an example of a conventional vehicle air conditioner, an apparatus including a heater core and a PTC heater that assist in heating operation by a heat pump refrigeration cycle to improve heating performance is known (see, for example, Patent Document 1). The heat pump refrigeration cycle described in Patent Document 1 is formed by connecting a compressor 14, a condenser 16, a liquid tank 17, an expansion valve 18, and an evaporator 19 in this order in an annular manner with refrigerant piping. In the unit case 11 having an air passage for sending the air taken in by the blower toward the vehicle interior, the evaporator 19, the mix door 38, the heater core 36, the PTC heater 35, the condenser are sequentially arranged in the air flow direction. 16 are arranged side by side. The PTC heater 35 plays a role of supplementing the heating performance by being energized at the time of start-up or low load, which tends to have insufficient heating performance.
Japanese Patent Laid-Open No. 11-235919 (see FIG. 1)

  However, when the expansion valve 18 described in Patent Document 1 is not a valve that can electrically adjust the refrigerant pressure after the condenser 16 freely, for example, in the case of a fixed throttle, a differential pressure expansion valve, a constant pressure expansion valve, etc. Since the refrigerant discharged from the compressor 14 during the heating operation with dehumidification (hereinafter referred to as dehumidifying heating operation) flows in the order of the condenser 16, the expansion valve 18, and the evaporator 19, the high-pressure side pressure and the low-pressure for a certain air load condition The side pressure is uniquely determined. For this reason, the dehumidifying performance determined on the low pressure side (the heat absorption performance of the evaporator 19) and the blowing temperature determined on the high pressure side cannot be controlled to desired values simultaneously.

  Further, when a conventional vehicle air conditioner is applied to a hybrid vehicle or the like that travels with a battery when the engine is started and then travels in a hybrid manner with the battery and the engine, the exhaust heat of the engine passes through the heater core 9 during the hybrid travel. May be used for heating. In this case, the heat from the heater core 9 is added to the air from the middle of the dehumidifying heating operation, and the blowing temperature may become too higher than the target blowing temperature.

  At this time, if the number of rotations of the compressor 14 is reduced, the pressure on the high pressure side decreases, and the blowing temperature that has become too high decreases. On the other hand, the endothermic amount of the evaporator 19 decreases and the air temperature at the evaporator outlet increases. Therefore, there is a problem that a necessary dehumidifying amount cannot be secured. In addition, when the dehumidifying operation is first performed in the cooling cycle operation, dehumidification can be performed at the start-up when the hot water flowing through the heater core 9 is not fully raised, but the target blowing temperature cannot be achieved because the heating capacity is insufficient. There is a problem that the heating performance cannot be achieved.

  Therefore, the present invention has been made in view of the above problems, and for a vehicle that performs control that can satisfy both the blowing temperature and the dehumidifying performance when the heating capacity is increased by heating means other than the refrigeration cycle in the dehumidifying operation. An object is to provide an air conditioner.

In order to achieve the above object, the following technical means are adopted. That is, according to the first aspect of the present invention, the compressor (21) that sucks and discharges the refrigerant, and the dehumidifying heating cycle operation that performs dehumidification by the flow of the refrigerant discharged from the compressor (21) and the vehicle interior during the heating cycle operation. The heat exchanger (22) for heating the air to be blown, and the refrigerant cooled by the heat exchanger (22) for heating in the dehumidifying and heating cycle operation and the heating cycle operation is reduced to a pressure determined by the refrigerant pressure before flowing in. A pressure reducing device (24) for performing the heating cycle operation, evaporating the refrigerant decompressed by the pressure reducing device (24) to absorb heat, and dissipating heat during the cooling cycle operation, and a dehumidifying heating cycle operation and cooling Heat pump refrigeration cycle (20) having a heat exchanger (30) for cooling that cools the air blown into the passenger compartment by the endothermic action of refrigerant flowing inside during cycle operation ,
An air intake (3, 4) is formed on one side, and a blow-off opening (11, 12, 13) through which the blown air passes into the vehicle interior is formed on the other side, and the air intake (3, 4) An air conditioning case (1) having a ventilation path (6, 7) through which the blown air passes between the air outlet and the blowout opening (11, 12);
The blown air taken in from the air intake (3, 4) is divided into air that passes through the heating heat exchanger (22) and air that does not pass through the heating heat exchanger (22), and the air volume ratio is determined. Air volume ratio adjusting means (8) to be adjusted;
An exhaust heat utilization heating means (9) provided inside the air conditioning case (1) for heating the blown air using heat generated from the engine or the battery;
An electric auxiliary heating means (40) which is provided inside the air conditioning case (1) and generates heat when energized to heat the blown air;
By controlling the operation of the heat pump refrigeration cycle (20), the operation of the air volume ratio adjusting means (8), and the energization of the electric auxiliary heating means (40), the blowing temperature before the blown air is blown into the vehicle interior is controlled. It is invention which concerns on the vehicle air conditioner provided with the control apparatus (50) to control.

  In the vehicle air conditioner, the control device (50) switches from the dehumidifying heating cycle operation to the cooling cycle operation according to the exhaust heat load applied to the blown air by the exhaust heat utilization heating means (9) during the dehumidifying heating cycle operation. Further, the electric auxiliary heating means (40) is energized.

  According to this invention, during the dehumidifying heating cycle operation, the dehumidifying performance is ensured by the refrigeration cycle operation in accordance with the exhaust heat load amount by the exhaust heat utilization heating unit, and the blowout temperature is added by the electric auxiliary heating unit. By executing the control, it is possible to perform control that can satisfy both the blowing temperature and the dehumidifying performance even when the heating capacity becomes excessive due to the heating of the exhaust heat utilization heating means. That is, even in such a case, a desired air conditioning environment can be provided to the passenger.

  Further, the vehicle air conditioner includes temperature detection means (16) for detecting the blowout temperature, and the control device (50) is configured such that the blowout temperature detected by the temperature detection means (16) during the dehumidifying and heating cycle operation is a predetermined value. If it is determined that the temperature is higher than that, it is preferable to switch from the dehumidifying and heating cycle operation to the cooling cycle operation and further energize the electric auxiliary heating means (40). According to the present invention, since it is detected that the heating capacity is in an excessive state based on the actual blowing temperature, the tendency that the blowing temperature becomes too high can be known more directly.

  The vehicle air conditioner includes a discharge pressure detecting means (17) for detecting the pressure of the refrigerant discharged by the compressor (21), and an exhaust heat load detecting means (15) for detecting the amount of the exhaust heat load. The control device (50) calculates the blowing temperature from the detected discharge pressure (Pd) and the detected amount of exhaust heat load, and when the calculated blowing temperature is higher than a predetermined value during the dehumidifying heating cycle operation. When it is determined, it is preferable to switch from the dehumidifying and heating cycle operation to the cooling cycle operation and further energize the electric auxiliary heating means (40).

  According to the present invention, the blowing temperature is calculated based on the discharge pressure and the exhaust heat load, and it is predicted that the heating capacity will be in an excessive state. Therefore, it is possible to more accurately predict the tendency that the blowing temperature becomes too high. it can.

  Moreover, it is preferable that the said waste heat utilization heating means (9) is comprised with the heater core which supplies the exhaust heat from an engine via an engine cooling water. According to this, when the engine is started during the dehumidifying heating operation and the amount of heat generated from the heater core increases due to the engine cooling water, the current operation cannot balance the blowing temperature and the dehumidifying performance. It is possible to detect in advance, and it is possible to detect in advance a tendency to make the passenger feel uncomfortable.

  The decompression device (24) is preferably a fixed expansion valve. According to this, even in a low-cost refrigeration cycle in which the refrigerant pressure cannot be adjusted over a wide range, both the blowing temperature and the dehumidifying performance can be reduced when the heating capacity becomes too large due to the exhaust heat load from the exhaust heat utilization heating means. A refrigeration cycle that can be controlled and can ensure the comfort of the passenger is obtained.

  In addition, the code | symbol in parentheses in each said technical means and each claim of a claim is an example which shows a corresponding relationship with the specific means of embodiment mentioned later.

  A plurality of modes for carrying out the present invention will be described below with reference to the drawings. In each embodiment, parts corresponding to the matters described in the preceding embodiment may be denoted by the same reference numerals, and redundant description may be omitted. In the case where only a part of the configuration is described in each embodiment, the other parts of the configuration are the same as those described previously. In addition to the combination of parts specifically described in each embodiment, the embodiments may be partially combined as long as the combination is not particularly troublesome.

(First embodiment)
1st Embodiment which is one Embodiment of this invention is described according to FIGS. 1-4. FIG. 1 is a schematic view showing a configuration of a vehicle air conditioner according to the present embodiment. FIG. 2 is a block diagram showing a control configuration in the vehicle air conditioner. In FIG. 1, the thick black arrow indicates the refrigerant flow in the refrigeration cycle during the heating cycle operation, the hatched thick arrow indicates the refrigerant flow in the refrigeration cycle during the dehumidification cycle operation, The refrigerant | coolant flow in the refrigerating cycle at the time of a cooling cycle operation is shown.

  The vehicle air conditioner of the present embodiment includes a heat pump refrigeration cycle 20, a PTC heater 40 that is an electric auxiliary heating means, and a waste heat utilization heating means, and performs an air conditioning operation using the components shown in FIG. For example, it can be used for hybrid vehicles, electric vehicles, fuel cell vehicles, and the like. As the electric auxiliary heating means, it is preferable to select a device with low energy loss that can obtain an output (heat generation amount) equivalent to the input with respect to the input (energization amount). In this embodiment, as an example, a PTC heater is used. 40 is adopted. The exhaust heat utilization heating means is an apparatus that heats the blown air using heat generated from a battery such as a traveling engine or a fuel cell vehicle.

  An air conditioning case 1 having an air ventilation path inside is provided on the back side of an instrument panel in the front of the passenger compartment. The air conditioning case 1 is formed with an air intake port 3 and an indoor air intake port 4 which are air intakes on one side, and air-conditioned air (hereinafter referred to as conditioned air) blown into the passenger compartment passes through the other side. A foot blowout opening 11, a face blowout opening 12, and a differential blowout opening 13 are formed at least.

  The foot blowing opening 11 is an opening through which conditioned air blown to the feet of the passenger in the passenger compartment passes, and the face blowing opening 12 is an opening through which conditioned air blown toward the upper body of the passenger in the passenger compartment passes. The differential blowing opening 13 is an opening through which conditioned air blown to the inner surface of the windshield of the vehicle passes. Each of these openings is connected to the vehicle interior space via a blowout duct (not shown), and is opened and closed by a blowout opening switching door (not shown) corresponding to the blowout mode. The outside air inlet 3 and the inside air inlet 4 can be opened and closed by an inside / outside air switching door 10 in accordance with the air intake mode.

  The air conditioning case 1 includes an inside / outside air switching box provided with an inside / outside air switching door 10 and a blower 5 whose suction part is connected to the outside air inlet 3 and the inside air inlet 4 on one side. For example, at the time of heating such as in winter, the anti-fogging effect can be enhanced by introducing outside air having low humidity from the outside air inlet 3 by performing the outside air intake mode, air-conditioning through the ventilation path, and blowing out to the inner surface of the windshield. . Further, by performing the inside air mode, it is possible to reduce the heating load by introducing high temperature inside air from the inside air inlet 4, air-conditioning through the ventilation path, and blowing out toward the feet of the passengers.

  The blower 5 includes a centrifugal multiblade fan (for example, a sirocco fan) and a motor that drives the fan. The periphery of the centrifugal multiblade fan is surrounded by a scroll casing. The air conditioning case 1 includes a plurality of case members, and the material thereof is a resin molded product such as polypropylene.

  The blower outlet of the blower 5 is connected to a ventilation path provided so as to extend in the centrifugal direction of the centrifugal multiblade fan. This ventilation path includes, in order from the upstream side of the blown air, a path traversed by the evaporator 30 that is a heat exchanger for cooling, and a foot outlet side path extending from the downstream side of the blower air of the evaporator 30 toward the foot outlet opening 11. 6 and the face blowing side passage 7 extending from the downstream side of the blast air of the evaporator 30 toward the face blowing opening 12, and the air mixing section in which the air flowing through the foot blowing side passage 6 and the face blowing side passage 7 is mixed. It consists of. The foot outlet side passage 6 and the face outlet side passage 7 are partitioned by a partition wall 18 provided in the air conditioning case 1 and arranged so as to be lined up in the transverse direction inside the air conditioning case 1.

  In the ventilation path in the air-conditioning case 1 on the downstream side of the blower air with respect to the blower 5, the evaporator 30, the heater core 9, the condenser 22 (heating heat exchanger), PTC are arranged in order from the upstream side to the downstream side. A heater 40 (electric auxiliary heating means) is disposed.

  The evaporator 30 is arrange | positioned so that the whole channel | path immediately after the air blower 5 may be crossed, and all the air blown off from the air blower 5 passes. The evaporator 30 is a cooling heat that dehumidifies and cools the blown air before flowing into the foot blowing side passage 6 and the face blowing side passage 7 by the endothermic action of the refrigerant flowing inside during the cooling operation and the dehumidifying operation. Functions as an exchange. A post-evaporator temperature sensor 14 that detects the temperature of the air cooled by the evaporator 30 is provided at the outlet of the evaporator 30 through which air passes (downstream part of the evaporator 30). A signal detected by the post-evaporator temperature sensor 14 is input to the control device 50.

  Exhaust heat utilization heating means is provided in the ventilation path in the air conditioning case 1. The heater core 9 is an example of a waste heat utilization heating means, and is a heat exchanger having a heat exchange section. This heat exchanging part is included in a part of the circulation circuit by being connected to an engine or a battery as a heat source by piping. Circulating water exists in the circulation circuit, and the amount of heat generated from the heat generation source is conveyed to the heat exchange unit by the circulating water. The heater core 9 is arranged on the downstream side of the blown air from the evaporator 30 so that at least the heat exchanging portion thereof is located only in the foot outlet side passage 6. The heater core 9 heats the surrounding air by dissipating the heat of the cooling water of the vehicle travel engine flowing inside, for example, during the heating cycle operation.

  The temperature of the cooling water flowing inside the heater core 9 is detected by the water temperature sensor 15 and input to the control device 50. The control device 50 calculates the heating amount that the exhaust heat utilization heating means gives to the blown air using the detected temperature Tw of the water temperature sensor 15 (representing the exhaust heat load amount by the exhaust heat utilization heating means). That is, the control device 50 can calculate the heating capacity of the air conditioner using the detected temperature Tw, and can determine whether or not the calculated heating capacity satisfies the blowing temperature.

  The condenser 22 is disposed such that at least the heat transfer portion is located only in the foot outlet side passage 6, and is disposed further downstream of the blowing air than the heater core 9. The condenser 22 functions as a heating heat exchanger that heats the blown air flowing through the foot outlet side passage 6 by the heat radiation action of the refrigerant flowing inside during the heating cycle operation, the dehumidification cycle operation, and the cooling cycle operation.

  The PTC heater 40 is arranged such that at least its heat transfer portion is located only in the foot outlet side passage 6 and is further arranged downstream of the blower air than the condenser 22. The PTC heater 40 is an auxiliary heating means for heating the blown air flowing through the foot outlet side passage 6 in the heating cycle operation and the cooling cycle operation. The PTC heater 40 includes an energized heat generating element portion, and generates heat when the energized heat generating element portion is energized to warm the surrounding air. The control device 50 can control the amount of heat input to the PTC heater 40 to control the amount of heat generated by the PTC heater 40 and adjust the blowing temperature.

  This energization heating element portion is configured by fitting a plurality of PTC elements in a resin frame formed of a heat-resistant resin material (for example, 66 nylon, polybutadiene terephthalate, etc.). Moreover, the PTC heater 40 may further include a heat exchange fin portion that transmits heat generated from the energized heat generating element portion. This heat exchange fin part is brazed to a corrugated fin obtained by forming a thin aluminum plate into a corrugated shape and an aluminum plate that keeps the corrugated fin in a certain shape and secures a contact area with the PTC element and the electrode plate. It is constituted by doing.

  A passage outlet temperature sensor 16 for detecting the temperature of the air flowing out from the passage is provided in the foot outlet side passage 6 downstream of the PTC heater 40, that is, in the foot outlet side passage 6 before flowing into the air mixing section. Is provided. A signal detected by the passage outlet temperature sensor 16 is input to the control device 50.

  In the ventilation path downstream of the evaporator 30 and upstream of the heater core 9 and the condenser 22, the air that has passed through the evaporator 30 is divided into air that passes through the condenser 22 and air that bypasses the condenser 22. An air mix door 8 is provided that can adjust the air volume ratio of these airs by dividing or switching.

  The air mix door 8 can block part or all of the foot outlet side passage 6 and the face outlet side passage 7 by changing the position of the door body by an actuator or the like. The opening degree of the foot outlet side passage 6 by the air mix door 8 is the ratio at which the transverse opening (hot side opening) of the foot outlet side passage 6 is opened, and ranges from 0 to 100%. It can be adjusted. Further, the opening degree of the face outlet side passage 7 by the air mix door 8 is a ratio in which the opening in the transverse direction (cool side opening) of the face outlet side passage 7 is opened, and is in a range of 0 to 100%. It can be adjusted.

  The heat pump refrigeration cycle 20 performs cooling, heating and dehumidification by the cooling evaporator 30 and the heating condenser 22 by utilizing the state change of the refrigerant (for example, R134a, CO2 etc.) flowing in the refrigeration cycle. It can be carried out.

  As shown in FIG. 1, the components of the heat pump refrigeration cycle 20 are configured to exchange heat between the compressor 21 that sucks and discharges the refrigerant and the refrigerant and air discharged from the compressor 21 during the heating cycle operation. A condenser 22 for heating, an expansion valve 24 as a decompression device for decompressing the refrigerant flowing from the condenser 22 during the heating cycle operation, and an outdoor heat exchanger 25 for evaporating the refrigerant decompressed by the expansion valve 24 during the heating cycle operation. And an electromagnetic valve 26 provided so as to control the refrigerant flow from the outdoor heat exchanger 25 to the compressor 21, and an accumulator 27 for separating the refrigerant from gas and liquid, and these are connected in an annular shape by piping. (Heating cycle operation path (compressor 21 → condenser 22 → three-way valve 23 → expansion valve 24 → branch section 32 → outdoor heat exchanger 25 → solenoid valve 26) Accumulator 27 → compressor 21)). Furthermore, a discharge pressure sensor 17 that detects the pressure of the high-pressure refrigerant discharged by the compressor 21 is provided at the outlet of the compressor 21.

  Further, in the heat pump refrigeration cycle 20, a dehumidification cycle operation path (expansion valve 24 → branch part 32 → branch part 34 → solenoid valve 31 → evaporator 30 → accumulator 27 → compressor 21) is configured such that each component is annularly formed by piping. It is formed by connecting. In this dehumidification cycle operation path, the refrigerant depressurized by the expansion valve 24 during the dehumidification cycle operation does not flow into the outdoor heat exchanger 25 but flows into the evaporator 30 and then sucked into the compressor 21 via the accumulator 27. It is a route. A three-way valve 23 is provided in the middle of the pipe connected to the downstream side of the condenser 22.

  Furthermore, in the heat pump refrigeration cycle 20, the cooling cycle operation path (condenser 22 → three-way valve 23 → branch portion 33 → outdoor heat exchanger 25 → branch portion 32 → branch portion 33 → solenoid valve 28 → expansion valve 29 → evaporation The container 30 → the accumulator 27 → the compressor 21) is formed by connecting the respective components in a ring shape by piping. In the cooling cycle operation path, the refrigerant cooled by exchanging heat with the blown air in the condenser 22 during the cooling cycle operation is branched without passing through the expansion valve 24 by switching the three-way valve 23 to the flow path on the branch portion 33 side. It flows into the outdoor heat exchanger 25 through the section 33, passes through the flow path opened by the electromagnetic valve 28, is decompressed by the expansion valve 29, then flows into the evaporator 30, and passes through the accumulator 27 to the compressor 21. It is a route to be inhaled.

  The outdoor heat exchanger 25 is disposed outside the vehicle compartment of the vehicle, and exchanges heat between the outside air forcedly blown by the outdoor fan and the refrigerant. The expansion valve 24 and the expansion valve 29 have a mechanism in which the refrigerant pressure after flowing out of the expansion valve is determined by the refrigerant pressure before flowing into the expansion valve. For example, the expansion valves 24 and 29 include a fixed expansion valve (for example, a capillary tube) such as a fixed throttle, a differential pressure type expansion valve that generates a constant differential pressure before and after, and the like. When a fixed expansion valve is employed, a fixed throttle is directly connected to the outlet of the condenser 22, and an accumulator cycle is configured in which the outlet refrigerant of the condenser 22 is directly decompressed and expanded by the fixed throttle. The decompressed low-pressure refrigerant absorbs heat by the evaporator 30 and evaporates, and the refrigerant that has passed through the evaporator 30 flows into the accumulator 27, and the accumulator 27 separates the gas and liquid at the outlet refrigerant of the evaporator 30. The gas refrigerant in the accumulator 27 can be sucked into the compressor 21.

  The compressor 21 can perform rotation speed control and ON-OFF control. The compressor 21 is applied with an AC voltage whose frequency is adjusted by an inverter, and the rotational speed of the motor is controlled. The inverter is supplied with DC power from a vehicle-mounted battery and is controlled by the control device 50. The compressor 21 is also a variable capacity compressor that can change the compression capacity of the refrigerant. The compressor 21 is provided with a capacity control valve that is a capacity control mechanism that changes the discharge capacity. The capacity control valve is an electromagnetically driven valve, for example, an open / close valve that can repeatedly open and close the refrigerant supply passage by duty control. The capacity control valve is controlled by a control device 50 to supply a duty signal type current having a binary value of ON-OFF as a capacity control signal, thereby controlling the valve opening time.

  The capacity control valve is actuated by the capacity control signal from the control device 50, and the control pressure Pc in the case of the compressor 21 changes. When the control pressure Pc changes, the stroke of the piston or the like changes and the capacity of the compressor 21 changes.

  The duty signal is a pulsed current signal that repeats ON and OFF every short time. ON / OFF of the signal corresponds to opening and closing of the capacity control valve. The capacity of the compressor 21 decreases when the capacity control valve is opened, and increases when the capacity control valve is closed. That is, when the capacity needs to be reduced, a signal for increasing the valve opening time is sent to increase the control pressure Pc, and when the capacity needs to be increased, a signal for shortening the valve opening time is sent to decrease Pc. By changing the duty ratio of the pulse signal in this way, the capacity of the compressor 21 can be changed steplessly and freely controlled.

  The control device 50 is a device that controls the air conditioning in the vehicle interior, and includes signals from the microcomputer and various switches on the operation panel 51 provided in the front of the vehicle interior, the post-evaporator temperature sensor 14, the water temperature sensor 15, An input circuit to which sensor signals are input from a passage outlet temperature sensor 16, an outside air temperature sensor, an evaporator temperature sensor (fin sensor), a discharge pressure sensor 17, a refrigerant temperature sensor at the outlet of the outdoor heat exchanger 25, and the like, and various actuators And an output circuit for sending an output signal. The microcomputer includes a memory such as a ROM (read only storage device) and a RAM (read / write storage device), a CPU (central processing unit), and the like, and is based on an operation command transmitted from the operation panel 51 or the like. It has various programs used for calculation.

  The control device 50 receives the air conditioner environment information, the air conditioner operating condition information, and the vehicle environment information, calculates them, and calculates the capacity to be set for the compressor 21. The control device 50 is also an air conditioner control amplifier, and outputs a capacity control signal of a duty signal suitable for the capacity as a current to the capacity control valve to control the capacity of the compressor 21.

  When an occupant operates the operation panel 51, operation signals such as operation / stop of the air conditioner and set temperature are input to the control device 50, and detection signals of various sensors are input, the compressor 21 and the blower are accordingly input. 5, the operation of each device such as the PTC heater 40 and the electromagnetic valves 26, 28, and 31 is controlled by the control device 50.

  Next, the operation of each operation mode (cooling, heating, dehumidification) of the vehicle air conditioner according to the above configuration will be described. When the air conditioner switch of the operation panel 51 is in the ON state, the control device starts the compressor 21, and determines that the operation mode to be operated from the temperature set by the occupant and the signals received from the various sensors is the cooling operation. The flow direction of the valve 23 is controlled to the branching portion 33 side (broken line in FIG. 1), the electromagnetic valve 28 is opened, and the electromagnetic valve 26 and the electromagnetic valve 31 are closed. Further, the control device 50 controls the blowout opening switching door so that the blowout mode is the face blowout because of the cooling operation.

  The flow of the refrigerant during the cooling cycle operation is the flow indicated by the white thick arrow in FIG. 1, and the high-temperature and high-pressure gas refrigerant discharged from the compressor 21 flows into the condenser 22 and passes through the condenser 22. Although the surrounding air is deprived of heat and cooled, since the blowing mode is face blowing, the amount of air passing through the periphery of the condenser 22 is small and the degree of cooling is not large. Then, the refrigerant passes through the branch portion 33 by the three-way valve 23 and flows into the outdoor heat exchanger 25. When the refrigerant passes through the outdoor heat exchanger 25, heat is taken away by the air blown by the outdoor fan, and the mist is cooled. A refrigerant.

  Thereafter, the mist refrigerant passes through the electromagnetic valve 28, is decompressed by the expansion valve 29, flows into the evaporator 30, and absorbs heat from the blown air flowing through the ventilation path in the air conditioning case 1 by the blower 5. The refrigerant is vapor-liquid separated by the accumulator 27 and then sucked into the compressor 21. The cool air absorbed and cooled by the evaporator 30 further travels through the ventilation path and is mainly blown out from the face blowing opening 12 toward the upper body of the occupant to cool the passenger compartment.

  Next, the flow of the refrigerant when the heating cycle operation is performed will be described. When the control device 50 activates the compressor 21 when the air conditioner switch of the operation panel 51 is ON, and determines the mode to be operated from the temperature set by the occupant and the signals received from the various sensors as the heating cycle operation, The flow direction of the three-way valve 23 is controlled to the expansion valve 24 side, the electromagnetic valve 26 is opened, and the electromagnetic valve 28 and the electromagnetic valve 31 are closed. Further, the control device 50 controls the blowout opening switching door so that the blowout mode becomes the foot blowout or the differential blowout according to the set temperature because it is during the heating operation.

  The refrigerant flow during the heating cycle operation is the flow indicated by the thick black arrows in FIG. 1, and the high-temperature and high-pressure gas refrigerant discharged from the compressor 21 flows into the condenser 22 and passes through the condenser 22. The surrounding air blows away heat and cools and condenses. Then, the refrigerant flows into the expansion valve 24, and the expansion valve 24 reduces the refrigerant pressure to an appropriate superheat degree at the outlet of the outdoor heat exchanger 25, and the expansion valve 24 is a fixed throttle valve. In some cases, the pressure is reduced to a predetermined low pressure. Thus, the refrigerant decompressed to a low pressure by the expansion valve 24 passes through the branch portion 32 and flows into the outdoor heat exchanger 25, and absorbs heat from the air blown by the outdoor fan when passing through the outdoor heat exchanger 25. Evaporate. The gas refrigerant evaporated in the outdoor heat exchanger 25 passes through the branch portion 33, passes through the electromagnetic valve 26, is separated into gas and liquid by the accumulator 27, and is then sucked into the compressor 21.

  Low-temperature air (for example, outside air in winter) taken into the air-conditioning case 1 during the heating cycle operation passes through the evaporator 30 and then flows mainly through the foot outlet side passage 6 by the air mix door 8 and by the condenser 22. Heated and becomes warm air. When the differential blow mode is performed during heating, the warm air passes through the condenser 22 and then blows out toward the inner surface of the front window through the differential blow opening 13 opened by the blow opening switching door. . When the foot blowing mode is performed during heating, the warm air passes through the condenser 22 and then blows out toward the passenger's feet through the foot blowing opening 11 opened by the blowing opening switching door.

  When the bi-level mode during the heating cycle operation is performed, the low-temperature air taken into the air-conditioning case 1 flows through each of the foot outlet side passage 6 and the face outlet side passage 7 by the air mix door 8. Will be divided by the appropriate air volume ratio. The low-temperature air flowing through the foot outlet side passage 6 becomes hot air heated by the condenser 22 and then heated by the PTC heater 40 to rise in temperature. The temperature is adjusted by mixing with the low-temperature air that has flown, and the air is blown out toward the passenger's feet through the foot blowing opening 11. On the other hand, the low-temperature air flowing through the face outlet side passage 7 does not pass through the heating means such as the condenser 22 and is not heated, and the warm air heated in the foot outlet side passage 6 at the air mixing section without being heated. And the temperature is adjusted, and the air is blown out toward the upper body of the occupant through the face blowing opening 12. In this way, air with an appropriate temperature difference (for example, 10 to 15 ° C.) is blown out between the upper body of the occupant and the feet of the occupant. Can be provided. In addition, when the target air temperature is high, it is good to carry out the heating by the heater core 9 positively.

  Next, the flow of the refrigerant when the dehumidification cycle operation is performed will be described. When the control device 50 activates the compressor 21 when the air conditioner switch of the operation panel 51 is in the ON state, and determines the mode to be operated from the temperature set by the occupant and the signals received from the various sensors as the dehumidifying operation, The flow direction of the valve 23 is controlled to the expansion valve 24 side, the electromagnetic valve 31 is opened, and the electromagnetic valve 26 and the electromagnetic valve 28 are closed. Further, since the control device 50 is in the dehumidifying operation, the control device 50 controls the blowout opening switching door so as to mainly perform differential blowout, foot blowout or rear foot blowout.

  In the dehumidification cycle operation, the refrigerant flows through the evaporator 30 and the condenser 22, and the blown air in the air conditioning case 1 is first cooled and dehumidified by the evaporator 30, and then heated by the condenser 22 to become warm air. This warm air is mainly blown out toward the inner surface of the front window through the differential blow-off opening 13 to exhibit an anti-fogging effect and dehumidify and heat the vehicle interior.

  The flow of the refrigerant during the dehumidification cycle operation is the flow indicated by the hatched thick arrows in FIG. 1, and the high-temperature and high-pressure gas refrigerant discharged from the compressor 21 flows into the condenser 22 and passes through the condenser 22. The surrounding air blows away heat and cools and condenses. Then, the refrigerant is depressurized by the expansion valve 24, and the refrigerant pressure is depressurized to an appropriate superheat degree at the outlet of the expansion valve 24. Thereafter, the refrigerant does not flow into the outdoor heat exchanger 25. 34 and flows into the evaporator 30. Inside the evaporator 30, the blower 5 absorbs heat from the blown air flowing through the ventilation path in the air conditioning case 1 and evaporates, and after being separated into gas and liquid by the accumulator 27, it is sucked into the compressor 21.

  The air that has been absorbed by the evaporator 30 and is cooled and dehumidified further passes through the ventilation path and is heated by the condenser 22. After passing through the condenser 22, the air is blown out toward the inner surface of the front window through the differential blowing opening 13 opened by the blowing opening switching door.

  Next, the operation of the vehicle air conditioner will be described with reference to FIGS. FIG. 3 is a chart showing the relationship between the progress of the water temperature of the heater core 9 and the operation cycle in the dehumidifying and heating operation and the dehumidifying and cooling operation. FIG. 4 is a flowchart showing a control flow when switching from the dehumidifying and heating operation to the dehumidifying and cooling operation. First, when an air conditioning operation command is input to the control device 50 by operating the operation panel 51 or the like, the air conditioning control processing is started, and the control device 50 starts a control program stored in a memory such as ROM or RAM to start RAM control. Initialize data stored in the.

  And the control apparatus 50 reads each data, such as setting conditions and the present air-conditioning environment conditions, by each signal being input from the operation panel 51 and various sensors (step 10), and uses the program memorize | stored in ROM. Then, the target blow temperature TAO of the air blown into the passenger compartment is calculated, and the blower level (the air volume of the blown air) of the blower 5 is calculated (step 20).

  Next, the control device 50 determines whether or not to proceed to step 30 and perform the dehumidifying and heating operation. The dehumidifying and heating operation is performed under the condition that both the humidity detected by the humidity sensor satisfies the dehumidifying operation start condition and the TAO is equal to or higher than a predetermined temperature (for example, 5 ° C.) or the operation panel 51. When both the dehumidifying operation switch is turned on and the TAO is above the predetermined temperature are satisfied. If any of these conditions is satisfied, the determination in step 30 is YES, and the process proceeds to step 80. In addition, when TAO is lower than a predetermined temperature, dehumidification heating operation is not performed because dehumidification is possible in the cooling operation.

  If neither of the above two conditions is satisfied, the determination in step 30 is NO, the process proceeds to step 40, and the control device 50 executes a process of calculating the opening degree of the inside / outside air switching door 10. This opening degree is calculated so that the temperature difference between the temperature of air sucked into the air-conditioning case 1 (hereinafter referred to as intake air temperature) and TAO is as small as possible. When the opening degree of the inside / outside air switching door 10 is calculated in step 40, the process proceeds to step 50, where the operation mode of the refrigeration cycle is set to the cooling cycle operation or the heating cycle operation. Determined according to the temperature difference.

  Next, the process proceeds to step 60, where the opening of the blowing opening switching door is determined based on the TAO and the blowing air volume, and the blowing mode is set to “Face”, “Bi-level”, “Foot”, “Foot / Dif”, Decide to be one of “def”. As described above, the control data determined in Steps 40, 50, and 60 is output to each device for control (Step 70). Thereafter, the process returns to Step 10 described above to repeat the processing, thereby continuing the air conditioning operation. Go.

  When it is determined in step 30 that either of the above two conditions is satisfied, the process proceeds to step 80, and each operation is performed so that the operation of the refrigeration cycle becomes the aforementioned dehumidification cycle operation to perform the dehumidification heating operation. Control the equipment. In this dehumidifying and heating operation, as shown in FIG. 3, even if the engine is started, the coolant temperature is still low and the temperature of the blown air is not increased. The PTC heater 40 is stopped in the maximum hot state where the foot outlet side passage 6 is opened to 100%. Therefore, the blowing temperature does not tend to increase.

  Next, the control device 50 determines whether or not the actual blowing temperature detected by the passage outlet temperature sensor 16 is higher than a predetermined value (step 90). The predetermined value is a value stored in the control device 50. For example, a temperature calculated so as to rise and fall with a certain width with respect to the target blowout temperature TAO may be adopted as the predetermined value.

  And when it determines with actual blowing temperature not being higher than predetermined value by step 90, the control apparatus 50 performs the process which maintains and continues the present dehumidification heating operation (step 95), and after. The air-conditioning operation is continued by returning to step 10 and repeating the process. Even in this case, the temperature of the cooling water is still low, the blowing temperature does not tend to rise rapidly, the opening degree of the air mix door 8 is in the maximum hot state, and the PTC heater 40 is stopped.

  Thereafter, when the temperature of the cooling water rises as time passes after the engine is started, the amount of heat generated from the heater core 9 which is the exhaust heat utilization heating means increases and the amount of heat released to the surrounding air increases. Then, when passing through the heater core 9, the blown air is heated, and further, the heating in the condenser 22 is added, and the temperature of the air blown out to the downstream air mixing unit rapidly increases. In such a situation, the blowing temperature becomes excessively high (the blowing temperature indicated by the broken line in FIG. 3), and the blowing wind that gives the passenger discomfort is provided in the vehicle interior. In order to suppress this, when the number of rotations of the compressor 21 is decreased to reduce the pressure on the high pressure side, the blowout temperature decreases, but conversely, the endothermic amount of the evaporator 30 decreases, and the air temperature after the evaporator decreases. As a result, the necessary amount of dehumidification cannot be ensured, resulting in the occurrence of window fogging and discomfort to the passengers.

  If it is determined in step 90 that the actual blowing temperature is higher than the predetermined value before such a situation occurs, the control device 50 proceeds to step 100 and starts the cooling cycle operation described above. In order to satisfy the calculated target blowout temperature TAO, in addition to the capacity control of the compressor 21, the opening control of the air mix door 8, and the control of other devices, the PTC heater 40 is energized to blow air into the vehicle interior. Air is heated (cooling dehumidification operation shown on the right side of FIG. 3). Thereafter, the air conditioning operation is continued by returning to step 10 and repeating the process.

  The cooling and dehumidifying operation performed in step 100 is an operation in which dehumidification is performed by a cooling cycle operation, and heating of the blown air is performed by the heater core 9 and the PTC heater 40. The control device 50 maintains the dehumidification capability by the refrigeration cycle by switching from the dehumidifying heating operation to the cooling dehumidifying operation, and the amount of heat decreased by the heat radiation of the condenser 22 is the heat radiation amount of the heater core 9 and the PTC heater 40. Can be supplemented. Furthermore, desired conditioned air can be provided to the occupant by appropriately controlling the opening degree of the air mix door 8 so as to achieve the target blowing temperature TAO.

  Further, after switching to the cooling and dehumidifying operation, as shown in FIG. 3, the amount of heat generated from the engine increases, so the temperature of the cooling water rises and the heating amount of the heater core 9 also rises. For this reason, the control device 50 once reduces the energization amount of the PTC heater 40 that has been operated at the maximum capacity and cools the opening of the air mix door 8 so that the face blowing side passage 7 is largely opened. Adjust the opening to the side. This control can provide air conditioning that adjusts the blow-out temperature to the target value while maintaining the necessary dehumidifying performance even if the coolant temperature rises with time.

  Next, another embodiment of the determination in step 90 will be described with reference to FIG. FIG. 5 is a flowchart showing another form of the control flow shown in FIG. This control flow is different from the control flow of FIG. 4 in that the process of step 85 is added and the determination of step 90A is different. The other steps are the same and have the same effects.

  Only different points will be described below. The control device 50 proceeds to step 85 after the process of step 80, reads the refrigerant pressure (discharge pressure Pd) on the high-pressure side of the refrigeration cycle detected by the discharge pressure sensor 17, and further detects the heater core detected by the water temperature sensor 15. The cooling water temperature Tw of No. 9 is read, and the outlet temperature is calculated using these temperatures (step 90). Next, it is determined whether or not the calculated blowing temperature is higher than a predetermined value (step 90A). This predetermined value is the same value as the predetermined value used for the determination in step 90 above.

  If it is determined in step 90A that the calculated value of the blow-out temperature is not higher than the predetermined value, the control device 50 executes the process of step 95 described above, and thereafter returns to step 10 and performs the process. The air conditioning operation is continued by repeating. On the other hand, if it is determined in step 90A that the calculated value of the blowing temperature is higher than the predetermined value, as described above, the processing of step 100 is executed, and the air conditioning operation is performed to ensure the target blowing temperature while maintaining the necessary dehumidifying performance. .

  The effect of the vehicle air conditioner according to this embodiment will be described below. The control device 50 of the vehicle air conditioner of the present embodiment controls the operation of the heat pump refrigeration cycle 20, the opening of the air mix door 8, and the energization of the PTC heater 40 so that the blown air in the air conditioning case 1 is the vehicle. A control device 50 is provided for controlling the blowing temperature before being blown into the room. During the dehumidifying and heating cycle operation, the control device 50 switches from the dehumidifying and heating cycle operation to the cooling cycle operation according to the exhaust heat load applied to the blown air by the heater core 9, and further energizes the PTC heater 40.

  According to this control, even when the heating amount of the heater core 9 which is an example of the exhaust heat utilization heating means becomes large and the heating capacity becomes excessive, the cooling cycle operation and the heating by the heater core 9 are performed before the blowing temperature rises too much. Since the dehumidification and heating operation combined with the heating by the PTC heater 40 are performed, the air conditioning that can satisfy both the target blowing temperature and the dehumidifying performance can be performed. In other words, when the heating capacity becomes too high, we switched to dehumidification in the cooling cycle operation, and compensated for the reduced heating capacity in the refrigeration cycle operation using the PTC heater 40 with a low body COP to ensure passenger comfort can do.

  If the controller 50 determines that the blowout temperature actually measured in step 90 is higher than a predetermined value during the dehumidifying and heating cycle operation, the control device 50 switches from the dehumidifying and heating cycle operation to the cooling cycle operation, and further energizes the PTC heater 40. .

  According to this control, since it is detected using the actual blowing temperature that the heating capacity is in an excessive state, the tendency that the blowing temperature becomes too high can be directly detected, and the controllability of the blowing temperature is more stable. Can be.

  Further, the control device 50 calculates the blowing temperature from the discharge pressure Pd detected in step 85 and the detected water temperature Tw, and the blowing temperature calculated in step 90A is higher than a predetermined value during the dehumidifying heating cycle operation. If it is determined, the dehumidifying and heating cycle operation is switched to the cooling cycle operation, and the PTC heater 40 is energized.

  According to this control, the blowing temperature is calculated and predicted from the amount of heat released from the condenser based on the discharge pressure Pd and the amount of exhaust heat load and the amount of heat generated by the exhaust heat utilization heating means, and the heating capacity becomes excessive. Is detected in advance, so that the tendency that the blowing temperature becomes too high can be predicted more accurately.

  In addition, by adopting the heater core 9 as the exhaust heat utilization heating means, when the engine is started during the dehumidifying heating operation and the amount of heat generated from the heater core increases due to the influence of the engine cooling water, It is possible to directly detect that the balance between the temperature and the dehumidifying performance cannot be achieved, and it is possible to detect in advance that the passenger feels uncomfortable.

  In addition, by adopting a fixed expansion valve as the decompression device, even in a low-cost refrigeration cycle in which the refrigerant pressure cannot be adjusted in a wide range, the heating capacity is increased due to the exhaust heat load other than the refrigeration cycle such as the heater core 9. If it becomes too much, the situation can be detected in advance and air conditioning can be implemented to ensure the comfort of the passengers.

(Other embodiments)
The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  For example, although the PTC heater 40 is employed as the electric auxiliary heating means in the above embodiment, the present invention is not limited to this. The electric auxiliary heating means may be another device as long as it is energized to generate heat from a heating element or the like to heat surrounding air or an object.

  Moreover, in the said embodiment, although the PTC heater 40 is arrange | positioned in the downstream of blowing air rather than the condenser 22, even if it arrange | positions in the upstream of blowing air rather than the condenser 22, heating cycle operation | movement and There is no change in the effect of heating the blown air during the cooling cycle operation corresponding to the transition region.

  In the air conditioning case 1 of the above embodiment, the foot outlet opening 11, the face outlet opening 12, and the differential outlet opening 13 are formed on the other side, but a rear foot outlet opening or the like may be formed in addition to this. Air-conditioning air blown to the feet of the passengers in the rear seat passes through the rear foot outlet. Each of these openings formed in the air conditioning case 1 is connected to the vehicle interior space via a blowout duct, and is opened and closed by a blowout opening switching door (not shown) corresponding to the blowout mode. It has become.

It is the schematic which showed the structure of the vehicle air conditioner which concerns on 1st Embodiment. It is the block diagram which showed the control structure in the vehicle air conditioner. It is the chart which showed the relationship between the water temperature progress of the heater core at the time of the dehumidification heating operation and dehumidification cooling operation of the vehicle air conditioner, and an operation cycle. It is the flowchart which showed the flow of control of the vehicle air conditioner. It is the flowchart which showed the other form of the control flow of the vehicle air conditioner shown in FIG.

Explanation of symbols

1 ... Air-conditioning case 3 ... Outside air intake (air intake)
4 ... Inside air intake (air intake)
6 ... Foot outlet side passage (ventilation path)
7… Face outlet side passage (ventilation path)
8 ... Air mix door (air volume ratio adjusting means)
9. Heater core (heating means using exhaust heat)
11 ... Foot outlet opening (outlet opening)
12 ... Face outlet opening (outlet opening)
13 ... Differential outlet opening (outlet opening)
15 ... Water temperature sensor (exhaust heat load detection means)
16 ... Passage outlet temperature sensor (temperature detection means)
20 ... Heat pump refrigeration cycle 21 ... Compressor 22 ... Condenser (heat exchanger for heating)
24 ... Expansion valve (pressure reducing device)
25 ... Outdoor heat exchanger 30 ... Evaporator (cooling heat exchanger)
40 ... PTC heater (electrical auxiliary heating means)
50 ... Control device

Claims (5)

A compressor (21) that sucks and discharges refrigerant, and heats the air blown into the vehicle compartment during dehumidification heating cycle operation and heating cycle operation in which dehumidification is performed by the refrigerant discharged from the compressor (21) flowing in A heat exchanger for heating (22), a pressure reducing device for reducing the refrigerant cooled by the heating heat exchanger (22) during the dehumidifying heating cycle operation and the heating cycle operation to a pressure determined by the refrigerant pressure before flowing in ( 24) an outdoor heat exchanger (25) that evaporates and absorbs heat by the refrigerant decompressed by the decompression device (24) during the heating cycle operation, and dissipates heat during the cooling cycle operation, and during the dehumidifying heating cycle operation and the cooling A heat pump refrigeration cycle having a cooling heat exchanger (30) for cooling the blown air into the passenger compartment by the endothermic action of the refrigerant flowing inside during cycle operation And (20),
Air intakes (3, 4) are formed on one side, and blow-off openings (11, 12, 13) through which the blown air passes toward the vehicle interior are formed on the other side, and the air intake (3 , 4) and an air-conditioning case (1) having a ventilation path (6, 7) through which the blown air passes between the blow-off openings (11, 12),
The blown air taken in from the air intake port (3, 4) is divided into air that passes through the heating heat exchanger (22) and air that does not pass through the heating heat exchanger (22), and its air volume. An air volume ratio adjusting means (8) for adjusting the ratio;
Exhaust heat utilization heating means (9) provided inside the air conditioning case (1) and heating the blown air using heat generated from an engine or a battery;
An electric auxiliary heating means (40) provided in the air conditioning case (1) and generating heat when energized to heat the blown air;
The blown air is blown into the vehicle interior by controlling the operation of the heat pump refrigeration cycle (20), the operation of the air volume ratio adjusting means (8), and the energization of the electric auxiliary heating means (40). A control device (50) for controlling the previous outlet temperature;
With
The control device (50) changes from the dehumidifying heating cycle operation to the cooling cycle operation according to the exhaust heat load applied to the blown air by the exhaust heat utilization heating means (9) during the dehumidifying heating cycle operation. The vehicle air conditioner is characterized in that the electric auxiliary heating means (40) is switched and further energized. Temperature detecting means (16) for detecting the blowing temperature,
When the control device (50) determines that the blowing temperature detected by the temperature detecting means (16) is higher than a predetermined value during the dehumidifying and heating cycle operation, the control device (50) changes from the dehumidifying and heating cycle operation to the cooling cycle operation. The vehicle air conditioner according to claim 1, characterized in that the electric auxiliary heating means (40) is switched and further energized. A discharge pressure detecting means (17) for detecting the pressure of the refrigerant discharged by the compressor (21), and an exhaust heat load detecting means (15) for detecting the amount of the exhaust heat load,
The control device (50) calculates the blowing temperature from the detected discharge pressure (Pd) and the detected amount of exhaust heat load,
If it is determined that the calculated blowing temperature is higher than a predetermined value during the dehumidifying and heating cycle operation, the dehumidifying and heating cycle operation is switched to the cooling cycle operation, and the electric auxiliary heating means (40) is energized. The vehicle air conditioner according to claim 1.   The vehicle air conditioning according to any one of claims 1 to 3, wherein the exhaust heat utilization heating means (9) comprises a heater core that supplies exhaust heat from the engine via engine cooling water. apparatus.   The vehicle air conditioner according to any one of claims 1 to 4, wherein the pressure reducing device (24) is a fixed expansion valve.

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