JP3915528B2 - Air conditioner for vehicles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention particularly relates to a front-seat-side air conditioning unit having a front-seat evaporator for air-conditioning a region on the front-seat side of the vehicle interior, and a rear-seat-side air-conditioning having a rear-seat-side evaporator for air-conditioning the region on the rear seat side of the vehicle interior. The present invention relates to a vehicle air conditioner including a unit.
[0002]
[Prior art]
Conventionally, in Japanese Examined Patent Publication No. 62-58926, in the defroster mode, the outside air introduction mode is forcibly set to introduce outside air having a lower humidity than the inside air into the air passage of the air conditioner and the refrigeration cycle is operated. It is described that the introduced air is dehumidified by the evaporator of the refrigeration cycle, and the dehumidified conditioned air is blown out from the defroster outlet toward the inner surface of the vehicle window glass.
[0003]
Thereby, when the defroster mode is selected, the anti-fogging performance of the vehicle window glass is improved so that the fog of the window glass can be removed rapidly.
[0004]
[Problems to be solved by the invention]
By the way, the above-mentioned prior art relates to a single air conditioner in which an air conditioning unit is disposed only on the front seat side of the vehicle interior as a unit for air conditioning in the vehicle interior, and only one evaporator is provided in the refrigeration cycle. There is no particular problem in the antifogging performance of the vehicle window glass. However, in a dual air-conditioning type refrigeration cycle in which air conditioning units are arranged on both the front and rear seats in the passenger compartment, the front seat air conditioning unit evaporator and rear seat air conditioning unit Since the evaporator and the condenser are used in common, the front seat air conditioning unit and the rear seat air conditioning unit are selected when the defroster mode is selected as the blowing mode of the front seat air conditioning unit. If the simultaneous operation is selected, there arises a problem that the dehumidifying capacity of the front seat evaporator decreases and the anti-fogging performance of the vehicle window glass decreases.
[0005]
More specifically, when the outside air temperature is low from spring to autumn, the front air conditioning unit normally selects the outside air introduction mode as the inside / outside air mode to prevent the vehicle window glass from fogging, and the outside air is It is introduced into the air passage of the seat side air conditioning unit. Therefore, since low temperature outside air flows into the front seat evaporator, the heat load on the front seat evaporator is reduced. For this reason, the opening degree of the expansion valve forming the front seat side pressure reducing means is reduced, and the refrigerant flow rate to the front seat side evaporator is reduced.
[0006]
On the other hand, in the rear seat side air conditioning unit, since the high temperature inside air flows into the rear seat side evaporator, the rear seat side evaporator has a higher heat load than the front seat side evaporator. As a result, the opening degree of the expansion valve constituting the rear seat side pressure reducing means is increased from that of the front seat side expansion valve, and the refrigerant flow rate to the rear seat side evaporator becomes larger than that of the front seat side evaporator.
[0007]
As a result, the refrigerant flow rate to the front seat evaporator connected in parallel with the rear seat evaporator in one refrigeration cycle is reduced, the dehumidifying capacity of the front seat evaporator is reduced, and the vehicle window glass is anti-fogged. This leads to a situation where performance decreases.
[0008]
In addition, when a variable capacity compressor that changes the discharge capacity is used as the compressor of the refrigeration cycle, the heat load of the entire refrigeration cycle is small at low outside air temperature, so the discharge capacity of the variable capacity compressor is small. . As a result, the reduction of the refrigerant flow rate to the front seat side evaporator is further promoted, and the anti-fogging performance is lowered.
[0009]
[Problems to be solved by the invention]
In view of the above, the present invention includes a front seat air conditioning unit that air-conditions the front seat side of the vehicle interior and a rear seat air conditioning unit that air-conditions the rear seat side of the vehicle interior, and the evaporator and rear of the front seat air conditioning unit. An object of the present invention is to secure a dehumidifying capacity of a front-seat-side evaporator at a low outside temperature in a dual air-conditioner type vehicle air-conditioner that is connected in parallel with an evaporator of a seat-side air-conditioning unit.
[0010]
[Means for Solving the Problems]
To achieve the above object, according to the first aspect of the present invention, the front seat side air conditioning unit (1) for air conditioning the front seat side of the vehicle interior and the rear seat side air conditioning unit (26) for air conditioning the rear seat side of the vehicle interior are provided. A front seat side air conditioner unit (1) and a front seat side evaporator (9) and a front seat side blower (8) for blowing air to the front seat side evaporator (9) are arranged, and the rear seat side air conditioner unit (26). The rear seat side evaporator (27) and the rear seat side blower (29) for sending air to the rear seat side evaporator (27) are arranged in the front seat evaporator (9) and the rear seat side evaporator (27). In parallel in the refrigeration cycle (10),
The front-seat side air conditioning unit (1) is a blowing mode in which a conditioned air is blown to the front seat occupant's face side, a foot mode in which the conditioned air is blown to the feet side of the front seat occupant, and the vehicle window glass side is air-conditioned At least the defroster mode that blows out the wind is set,
When the front seat side air conditioning unit (1) and the rear seat side air conditioning unit (26) are operated simultaneously, and the defroster mode is set as the blowing mode of the front seat side air conditioning unit (1) at the time of low outside air temperature. The refrigerant circulation to the rear seat side evaporator (27) is stopped, and the refrigerant circulation flow rate to the front seat side evaporator (9) is increased.
[0011]
As a result, even when the front and rear air conditioning units (1, 26) are simultaneously operated and the defroster mode is set at a low outside air temperature, the refrigerant circulation flow rate to the front seat evaporator (9) is automatically set. And the dehumidifying capacity of the front seat side evaporator (9) can be secured. Therefore, fogging of the vehicle window glass can be rapidly removed in a short time even at a low outside temperature.
[0012]
According to a second aspect of the present invention, in the first aspect, the compressor of the refrigeration cycle (10) includes a variable capacity compressor (11) that changes a discharge capacity, and the front seat side air conditioning unit (1) and the rear seat When the defroster mode is set as the blowing mode of the front seat air conditioning unit (1) during simultaneous operation of the side air conditioning unit (26) and at a low outside air temperature, the discharge of the variable capacity compressor (11) The capacity is the maximum capacity.
[0013]
As a result, when the variable capacity compressor (11) is used, the refrigerant circulation to the rear seat evaporator (27) is stopped, and at the same time, the discharge capacity of the variable capacity compressor (11) is set to the maximum capacity, It is possible to further increase the refrigerant circulation flow rate to the front seat evaporator (9), and thus the dehumidifying capacity.
[0014]
According to a third aspect of the present invention, in the first aspect, the compressor of the refrigeration cycle (10) includes a fixed capacity type compressor (11) having a fixed discharge capacity, and the operation of the fixed capacity type compressor (11). Is controlled so that the temperature (Te) of the front seat evaporator (9) becomes the target temperature (TEO), and the front seat air conditioning unit (1) and the rear seat air conditioning unit (26) are simultaneously controlled. When the defroster mode is set as the blowing mode of the front seat air conditioning unit (1) during operation and at low outside air temperature, the target temperature (TEO) is fixed at the lowest temperature near the freezing temperature of the condensed water. The operation of the capacity type compressor (11) is intermittently controlled.
[0015]
Thus, when the fixed capacity compressor (11) is used, the refrigerant circulation to the rear seat evaporator (27) is stopped, and at the same time, the operation rate of the intermittent control of the fixed capacity compressor (11) is increased. Thus, the refrigerant circulation flow rate to the front seat side evaporator (9), and thus the dehumidifying capacity, can be further increased.
[0016]
According to a fourth aspect of the present invention, in the first aspect, as the compressor of the refrigeration cycle (10), an electric compressor (11) having an adjustable rotation speed is provided, and the front seat side air conditioning unit (1) and the rear seat side are provided. When the defroster mode is set as the blowing mode of the front seat air conditioning unit (1) during simultaneous operation of the air conditioning unit (26) and at a low outside air temperature, the rotational speed of the electric compressor (11) is maximized. It is characterized by a rotational speed.
[0017]
Thus, when the electric compressor (11) is used, the refrigerant circulation to the rear seat side evaporator (27) is stopped, and at the same time, the number of rotations of the electric compressor (11) is maximized to increase the front seat side evaporator. The refrigerant circulation flow rate to (9), and thus the dehumidifying capacity, can be further increased.
[0018]
According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the outlet refrigerant of the rear seat side evaporator (27) is used as a pressure reducing means for the refrigerant flowing into the rear seat side evaporator (27). A thermal expansion valve (28) for adjusting the degree of superheat, and the front seat side air conditioning unit (1) and the rear seat side air conditioning unit (26) are operated simultaneously and at a low outside temperature. When the defroster mode is set as the blowing mode of (1), the operation of the rear seat blower (29) is stopped and the temperature type expansion valve (28) is closed.
[0019]
Thereby, the temperature-type expansion valve (28) is closed by stopping the operation of the rear seat side blower (29), and the refrigerant circulation to the rear seat side evaporator (27) can be stopped.
[0020]
According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the front seat side air conditioning unit (1) is configured to perform air conditioning with substantially the same amount of airflow toward the foot portion side of the front seat occupant and the vehicle window glass side. The foot defroster mode that blows out the wind at the same time is set, and the front seat air-conditioning unit (1) and the rear seat air-conditioning unit (26) are operated at the same time and when the outside air temperature is low. Even when the foot defroster mode is set as the blowing mode of the unit (1), the refrigerant circulation to the rear seat evaporator (27) is stopped and the refrigerant circulation flow rate to the front seat evaporator (9) is reduced. It is characterized by increasing.
[0021]
Thereby, not only in the defroster mode but also in the foot defroster mode, the dehumidifying ability of the front seat side evaporator (9) at the time of low outside air temperature can be secured, and the fog of the vehicle window glass can be removed rapidly in a short time. .
[0022]
In addition, the code | symbol in the bracket | parenthesis of each said means shows the correspondence with the specific means as described in embodiment mentioned later.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an outline of the overall configuration of the present embodiment. The vehicle air conditioner includes a front seat air conditioning unit 1 and a rear seat air conditioning unit 26 as indoor units. The front seat side air-conditioning unit 1 is disposed on the inner side of the foremost instrument panel (not shown) in the vehicle interior and air-conditions the area on the front seat side of the vehicle interior.
[0024]
The front seat side air conditioning unit 1 has a case 2 and forms an air passage through which air is blown toward the front seat side of the vehicle interior. An inside / outside air switching box 5 having an inside air introduction port 3 and an outside air introduction port 4 is arranged at the most upstream part of the air passage of the case 2. Inside / outside air switching box 5, an inside / outside air switching door 6 as inside / outside air switching means is rotatably arranged.
[0025]
The inside / outside air switching door 6 is driven by a servo motor 7, and an inside air introduction mode for introducing inside air (vehicle compartment air) from the inside air introduction port 3 and an outside air for introducing outside air (vehicle compartment outside air) from the outside air introduction port 4. Switch between introduction modes.
[0026]
On the downstream side of the inside / outside air switching box 5, an electric front seat side blower 8 that generates an air flow toward the passenger compartment is disposed. The blower 8 is configured to drive a centrifugal blower fan 8a by a motor 8b. A front seat side evaporator 9 for cooling the air flowing in the case 2 is disposed on the downstream side of the blower 8. The evaporator 9 is a cooling heat exchanger that cools the air blown from the blower 8 and is one of the elements constituting the refrigeration cycle 10.
[0027]
In the refrigeration cycle 10, the refrigerant circulates from the discharge side of the compressor 11 to the front seat side evaporator 9 through the condenser 12, the liquid receiver 13, and the expansion valve 14 that forms the front seat side pressure reducing means. It is a well-known one formed. Further, between the outlet side of the liquid receiver 13 and the suction side of the compressor 11, an expansion valve 28 that forms a rear-seat-side decompression unit and a rear part are provided in parallel with the front-seat side expansion valve 14 and the front-seat side evaporator 9. A seat side evaporator 27 is provided, and a refrigerant circulates in parallel between the front seat side evaporator 9 and the rear seat side evaporator 27.
[0028]
The compressor 11 is rotationally driven by the rotational power of a vehicle engine (not shown) being transmitted through an electromagnetic clutch 11a, a belt, and the like. In this example, the compressor 11 uses an external variable capacity compressor that continuously varies the discharge capacity by a control signal from the outside.
[0029]
The external variable capacity compressor 11 is a known one. For example, a capacity variable device 11b having an electromagnetic pressure control device for controlling the pressure in the swash plate chamber using the discharge pressure and the suction pressure in the swash plate compressor. It has. By controlling the pressure in the swash plate chamber with the variable capacity device 11b, the inclination angle of the swash plate is varied to continuously change the stroke of the piston, that is, the compressor discharge capacity in the range of approximately 0% to 100%. Can do.
[0030]
This electromagnetic pressure control device of the variable capacity device 11b changes the control pressure (swash plate chamber pressure) using the discharge pressure and suction pressure of the compressor 11, and the electromagnetic force is controlled by the control current In shown in FIG. And a valve body that is displaced by a balance between the electromagnetic force of the electromagnetic mechanism and the suction pressure, and the pressure loss of the passage that guides the discharge pressure of the compressor 1 into the swash plate chamber is adjusted by the valve body. Thus, the control pressure is changed.
[0031]
Energization of the variable capacity device 11b to the electromagnetic pressure control device is controlled by the output of the air conditioning control device 40 shown in FIG. 3 to be described later. For example, when the control current In of the variable capacity device 11b is increased, the compressor discharge capacity increases. It is designed to change direction. That is, the control current In of the variable capacity device 11b directly determines the target pressure of the low pressure (suction pressure) Ps of the refrigeration cycle, and the target pressure of the low pressure Ps is inversely proportional to the increase of the control current In. However, as shown in FIG. 2, the discharge capacity of the compressor changes in the increasing direction as the control current In increases.
[0032]
Accordingly, the discharge capacity of the compressor 11 and thus the discharge refrigerant flow rate are increased or decreased by increasing or decreasing the control current In to increase or decrease the actual low pressure Ps, and the temperature of the front seat side evaporator 9 (evaporator outlet temperature) is set to a predetermined value. The cooling capacity of the front seat side evaporator 9 can be controlled so as to be the target temperature (the temperature corresponding to the target pressure of the low pressure Ps). Here, the control current In is specifically variable by duty control, but the value of the control current In may be directly increased or decreased independently of duty control.
[0033]
In the refrigeration cycle 10, the refrigerant is compressed to a high temperature and high pressure by the compressor 11, and the high-pressure gas refrigerant discharged from the compressor 11 is introduced into a condenser (heat radiator) 12, where the gas refrigerant is Heat is exchanged with outside air blown by a cooling fan (not shown) to dissipate heat and condense. The refrigerant that has passed through the condenser 12 is separated into a liquid phase refrigerant and a gas phase refrigerant by the liquid receiver 13, and the liquid phase refrigerant is stored in the liquid receiver 13.
[0034]
The high-pressure liquid refrigerant from the liquid receiver 13 is depressurized to a low-pressure gas-liquid two-phase state by the front seat side temperature type expansion valve 14, and the low-pressure refrigerant after this pressure reduction is supplied from the conditioned air in the front seat side evaporator 9. It absorbs heat and evaporates.
[0035]
As is well known, the front seat side temperature type expansion valve 14 automatically adjusts the valve opening so that the refrigerant superheat degree at the outlet of the front seat side evaporator 9 is maintained at a predetermined value. Therefore, the temperature type expansion valve 14 includes a temperature sensing part that senses the refrigerant temperature at the outlet of the front seat evaporator 9, a first pressure chamber to which a pressure corresponding to the refrigerant temperature sensed by the temperature sensing part is applied, and evaporation. A second pressure chamber to which the refrigerant pressure (cycle low pressure) of the container 9 is applied, and a diaphragm for partitioning the first and second pressure chambers, depending on the pressure difference between the first and second pressure chambers and the spring force. The diaphragm and the valve body are displaced to adjust the refrigerant flow rate.
[0036]
The gas refrigerant that has evaporated in the front seat side evaporator 9 is again sucked into the compressor 11 and compressed. In the refrigeration cycle 10, devices such as the compressor 11, the condenser 12, and the liquid receiver 13 are arranged in an engine room (not shown) on the front side from the vehicle compartment.
[0037]
The rear seat side temperature type expansion valve 28 provided at the refrigerant inlet of the rear seat side evaporator 27 has the same configuration as the front seat side temperature type expansion valve 14, and the high pressure liquid refrigerant from the liquid receiver 13 is supplied to the low pressure gas. The pressure is reduced to a liquid two-phase state, and then circulated to the rear seat evaporator 27.
[0038]
On the other hand, in the front seat side air conditioning unit 1, a front seat side heater core 15 that heats the air flowing in the case 2 is disposed downstream of the front seat side evaporator 9. The heater core 15 is a heat exchanger for heating that uses warm water (engine cooling water) of the vehicle engine as a heat source and heats air (cold air) after passing through the evaporator 9. A bypass passage 16 through which the gas flows is formed.
[0039]
An air mix door 17 is rotatably disposed between the evaporator 9 and the heater core 15. The air mix door 17 is driven by a servo motor 18 so that its rotational position (opening) can be continuously adjusted. The amount of air passing through the heater core 15 (warm air amount) and the amount of air passing through the bypass passage 16 and bypassing the heater core 15 (cold air amount) are adjusted according to the opening degree of the air mix door 17, whereby the front seat in the vehicle interior The temperature of the air blown out to the side is adjusted.
[0040]
At the most downstream part of the air passage of the case 2 is a defroster outlet 19 for blowing conditioned air toward the front window glass W of the vehicle, and the front seat side for blowing conditioned air toward the face of the front seat passenger A total of three types of air outlets are provided: a face air outlet 20 and a front seat-side foot air outlet 21 for blowing air-conditioned air toward the feet of the front seat occupant.
[0041]
A defroster door 22, a front seat side face door 23, and a front seat side foot door 24 are rotatably disposed upstream of the air outlets 19 to 21. These doors 22 to 24 are driven by a common servo motor 25 through a link mechanism (not shown).
[0042]
Next, the rear seat side air conditioning unit 26 will be described. The rear seat side air conditioning unit 26 is disposed on the rear side of the vehicle interior so as to air-condition the rear seat side of the vehicle interior. The rear seat side air conditioning unit 26 has a case 26a that forms an air passage, and a rear seat side blower 29 that sucks and blows in internal air (vehicle compartment air) is disposed upstream of the case 26a. The rear seat blower 29 is configured to drive a centrifugal blower fan 29a by a motor 29b. The aforementioned rear seat evaporator 27 is disposed downstream of the rear seat blower 29 to cool the air flowing in the case 26a.
[0043]
A rear seat heater core 30 that heats air using hot water of the vehicle engine as a heat source is disposed downstream of the rear seat evaporator 27, and is downstream of the rear seat heater core 30, that is, the most downstream portion of the air passage of the case 26a. The rear-seat-side face outlet 31 for blowing air-conditioned air toward the face of the rear-seat occupant and the rear-seat-side foot outlet 32 for blowing air-conditioned air toward the foot of the rear-seat occupant Provided.
[0044]
And the rear seat side face door 33 and the rear seat side foot door 34 are each arrange | positioned rotatably at these blower outlets 31 and 32, respectively. The rear seat side face door 33 and the rear seat side foot door 34 are driven by a common servo motor 35 via a link mechanism (not shown).
[0045]
The rear seat air conditioning unit 26 is also provided with a temperature adjusting means (not shown) corresponding to the air mixing door 17 on the front seat side, so that the temperature of the air blown into the rear seat side space can be adjusted. ing.
[0046]
Next, the outline of the electric control unit of this embodiment will be described with reference to FIG. 3. The air conditioning control device 40 is composed of a known microcomputer including a CPU, a ROM, a RAM, and the like and its peripheral circuits. A control program for air conditioning control is stored in the ROM, and various calculations and processes are performed based on the control program. A sensor detection signal from the sensor group 41, an operation signal from the front seat side air conditioning panel 42, and an operation signal from the rear seat side air conditioning panel 43 are input to the input side of the air conditioning control device 40.
[0047]
The sensor group 41 is provided with an evaporator temperature sensor 41a that is disposed in an air blowing portion of the front seat side evaporator 9 and detects an evaporator blowing air temperature (evaporator cooling temperature) Te, and is detected by the temperature sensor 41a. The cooling capacity of the front seat side evaporator 9 is controlled by varying the discharge capacity of the compressor 11 in accordance with the evaporator blown air temperature Te. In addition to the evaporator temperature sensor 41a, various sensors 41b to 41d for detecting the outside air temperature Tam, the inside air temperature Tr, the solar radiation amount Ts, the hot water temperature Tw, and the like are provided.
[0048]
The front seat side air conditioning panel 42 is disposed in the vicinity of an instrument panel (not shown) in front of the driver's seat in the passenger compartment, and includes the following operation switches 42a to 42e operated by the occupant. The temperature setting switch 42a outputs a signal of the set temperature on the front seat side of the vehicle interior, and the inside / outside air switching switch 42b outputs a signal for manually setting the inside air mode and the outside air mode by the inside / outside air switching door 6.
[0049]
The blowout mode switch 42c outputs a signal for manually setting the face mode, the bi-level mode, the foot mode, the foot defroster mode, and the defroster mode as the front seat side blowout mode. The air volume changeover switch 42d outputs a signal for manually setting on / off of the front seat side blower 8 and air volume change of the front seat side blower 8, and the air conditioner switch 42e outputs an on / off signal of energization of the electromagnetic clutch 11a for compression. The operation of the machine 11 is interrupted.
[0050]
In the face mode, the front-seat face outlet 20 is fully opened, the defroster outlet 19 and the front-seat foot outlet 21 are closed, and the conditioned air is sent from the front-seat face outlet 20 only in front of the passenger compartment. This mode blows out to the face side of the seat occupant. In the bi-level mode, the front air outlet 20 and the foot air outlet 21 on the front seat side are fully opened, the defroster air outlet 19 is closed, and the front seat occupant from both the front air outlet 20 and the foot air outlet 21 on the front seat side. This is a mode in which air-conditioned air is blown out substantially the same amount toward the face side and the foot side of the front seat occupant.
[0051]
In the foot mode, the front-seat face outlet 20 is closed, the front-seat foot outlet 21 is fully opened, the defroster outlet 19 is opened by a small opening, and the conditioned air is mainly emitted from the front seat foot outlet 21. Is blown out toward the passenger's feet, and a small amount of conditioned air is blown out from the defroster outlet 19 to the inner surface side of the window glass W.
[0052]
The defroster mode is a mode in which the face air outlet 20 and the foot air outlet 21 on the front seat side are closed, the defroster air outlet 19 is fully opened, and the conditioned air is blown from the defroster air outlet 19 to the inner surface side of the window glass W. In the foot defroster mode, the front seat face outlet 20 is closed, the defroster outlet 19 and the front seat foot outlet 21 are fully opened, and substantially the same amount of air flows from the front seat foot outlet 21 and the defroster outlet 19. This mode is to blow out the conditioned air.
[0053]
On the other hand, the rear seat side air-conditioning panel 43 is disposed in the rear seat side area or the like of the vehicle interior, and the rear seat side blowing mode switch 43a is manually operated in the face mode, bi-level mode, and foot mode as the rear seat side blowing mode. A signal for setting is output. The rear seat air volume switching switch 43b outputs a signal for manually setting on / off of the rear seat air blower 29 and air volume switching of the rear seat air blower 29. The rear seat air volume switching and blowing mode switching operation signals may also be input from the front seat air conditioning panel 42.
[0054]
On the output side of the air conditioning control device 40, there are an electromagnetic clutch 11a of the compressor 11, a variable capacity device 11b, servo motors 7, 18, 25, 35 serving as electric drive means for each device, a motor 8b of the front seat side blower 8, and The motor 29b of the rear seat blower 29 is connected, and the operation of these devices is controlled by the output signal of the air conditioning controller 40.
[0055]
Next, the operation of this embodiment in the above configuration will be described. First, the outline of the operation as the vehicle air conditioning unit will be described. First, when both the front seat side air conditioning unit 1 and the rear seat side air conditioning unit 26 are operated, the air volume changeover switch 42d of the front seat side air conditioning panel 42 and The air volume changeover switch 43b of the rear seat side air conditioning panel 43 is turned on to operate both the front and rear fans 8 and 29 to blow air to both the air conditioning units 1 and 26.
[0056]
When the air conditioner switch 42e, which is a compressor operation switch of the front seat side air conditioning panel 42, is turned on, the electromagnetic clutch 11a is energized by the air conditioning control device 40 so that the electromagnetic clutch 11a is connected, and the compressor 11 is rotated by the vehicle engine. Driven. Further, the control current In of the variable capacity device 11b of the compressor 11 is calculated by the air conditioning control device 40 by the method of FIG. 4 described later, and the compressor 11 operates in a state of a predetermined discharge capacity.
[0057]
Accordingly, the refrigerant circulates in parallel in the front and rear evaporators 9 and 27 in the refrigeration cycle 10. Therefore, in the front seat side air conditioning unit 1, the blown air is cooled and dehumidified by the evaporator 9, and the conditioned air can be blown out to the front seat side space in the passenger compartment. Similarly, in the rear seat side air conditioning unit 26, the blown air can be cooled and dehumidified by the evaporator 27, and the conditioned air can be blown out to the rear seat side space in the passenger compartment.
[0058]
When both the front and rear air conditioning units 1 and 26 are operated simultaneously as described above, the front and rear temperature expansion valves 14 and 28 have valve openings corresponding to the cooling heat loads of the front and rear evaporators 9 and 27, respectively. The refrigerant having a flow rate adjusted and corresponding to the cooling heat load is always passed through the flow paths of the evaporators 9 and 27. Thereby, the superheat degree of the exit refrigerant | coolant of each evaporator 9 and 27 is adjusted to a predetermined value.
[0059]
Next, when the rear seat air conditioning unit 26 is stopped and only the front seat air conditioning unit 1 is operated alone, only the front seat air volume switching switch 42d is turned on, and the rear seat air volume switching switch 43b is turned off. To do. As a result, the rear seat blower 29 stops and no air is blown to the rear seat evaporator 27, so that the outlet refrigerant of the rear seat evaporator 27 is saturated corresponding to the ambient temperature, and the outlet refrigerant is superheated. Therefore, the rear seat side temperature type expansion valve 28 is in a closed state or a state close to closing. As a result, the circulation of the refrigerant to the rear seat side evaporator 27 is stopped in the refrigeration cycle 10, and the refrigerant circulates only to the front seat side evaporator 9.
[0060]
Next, the capacity control of the compressor 11 will be described with reference to FIG. 4. FIG. 4 is a control routine executed by the air conditioning control device 40. In step S100, the detection signal from the sensor group 41, the air conditioning panels 42, 43 Read operation signals. Next, in step 110, a target blowing temperature TAO of air blown into the vehicle interior is calculated. This target blowing temperature TAO is the temperature of the blowing air to the front seat side of the vehicle interior that is necessary to maintain the front seat side in the vehicle interior at the set temperature Tset set by the occupant regardless of the air-conditioning heat load fluctuation. Is calculated based on the set temperature Tset, the outside air temperature Tam, the inside air temperature Tr, and the solar radiation amount Ts as is well known.
[0061]
Next, the target evaporator temperature TEO of the front seat side evaporator 9 is calculated in step S120. The target evaporator temperature TEO is the target temperature of the air blown from the front seat evaporator 9, and is determined based on the TAO, the outside air temperature Tam, and the like.
[0062]
Next, in step S130, a control current In for compressor capacity control is calculated. This control current In determines the target low pressure of the electromagnetic pressure control device in the capacity variable device 11b of the compressor 11 as shown in FIG. 2, and the control current In is the front seat side evaporator 9. The actual evaporator outlet temperature Te detected by the outlet temperature sensor 41a is determined to be the target evaporator outlet temperature TEO.
[0063]
As a specific calculation method of the control current value In, first, a deviation En (En = Te−TEO) between the actual evaporator outlet temperature Te and the target evaporator outlet temperature TEO is calculated, and based on this deviation En. The control current value In may be calculated by a feedback control technique such as proportional integral control (PI control).
[0064]
Next, in step S140, the control current value In is output to the electromagnetic pressure control device of the capacity variable device 11b of the compressor 11, and the capacity control of the compressor 11 is executed.
[0065]
Next, the control for ensuring the anti-fogging performance of the vehicle window glass at the low outside air temperature will be described with reference to FIG. FIG. 5 is a subroutine that is interrupt-controlled at a predetermined time interval with respect to the basic control routine of FIG. 4. First, in step S200, it is determined whether the front seat blower 8 is operating. When the front seat side blower 8 is operating (that is, when the front seat side air conditioning unit 1 is in operation), the process proceeds to step S210, and the defroster mode or the foot defroster mode is selected as the blowing mode of the front seat side air conditioning unit 1. Judgment is made.
[0066]
Here, the defroster mode is a blowing mode for removing the fog of the window glass W by blowing out the entire amount (or most) of the conditioned air toward the inner surface of the vehicle window glass W. Further, in the foot defroster mode, about half of the air-conditioning air blowing amount is blown out toward the inner surface of the vehicle window glass W, and the remaining half of the air-conditioning air is blown out toward the passenger's feet to remove fogging of the window glass W and the passenger's feet. This is a blowing mode in which heating of the part is performed simultaneously. Therefore, both of these blowing modes are aimed at removing fogging of the window glass W.
[0067]
When the defroster mode or the foot defroster mode is selected, the process proceeds to step S220, and it is determined whether the inside / outside air introduction mode of the front seat air conditioning unit 1 is the outside air introduction mode. If the inside / outside air introduction mode is the inside air introduction mode, the process proceeds to step S230, and the rotational position of the servo motor 7 is controlled to drive the inside / outside air switching door 6 to the position of the outside air introduction mode. That is, whenever the blowing mode of the front seat air conditioning unit 1 is the defroster mode or the foot defroster mode, the inside / outside air introduction mode is set to the outside air introduction mode, and outside air having a lower humidity than the inside air is set to the front seat side air conditioning unit. 1 is introduced.
[0068]
In the next step S240, it is determined whether or not the air conditioner switch 42e, which is a compressor operation switch of the front seat air conditioning panel 42, is turned on. If the air conditioner switch 42e is not turned on, the process proceeds to step S250, the drive circuit of the electromagnetic clutch 11a is turned on, the electromagnetic clutch 11a is connected, and the compressor 11 is activated. That is, when the front seat side blowing mode is the defroster mode or the foot defroster mode, the compressor 11 is forcibly activated even when the air conditioner switch 42e is in the OFF state.
[0069]
In the next step S260, it is determined whether or not the outside air temperature Tam detected by the outside air temperature sensor 41b is equal to or lower than a predetermined temperature To. Here, the predetermined temperature To is a “threshold value” for determining whether the outside air temperature is a low outside air temperature, and is, for example, 15 ° C. When the outside air temperature Tam is higher than the predetermined temperature To, the process returns to step S200, and the outside air introduction mode and the operating state of the compressor 11 in the defroster mode or the foot defroster mode are maintained.
[0070]
On the other hand, when the outside air temperature Tam is equal to or lower than the predetermined temperature To, the process proceeds to step S270, and it is determined whether the blower 29 of the rear seat air conditioning unit 26 is in an operating (ON) state. When the rear seat blower 29 is in the operating state, the process proceeds to step S280 and the rear seat blower 29 is forcibly stopped (OFF).
[0071]
When the rear seat side blower 29 stops, the air blowing to the evaporator 27 of the rear seat side air conditioning unit 26 is stopped, so the degree of superheat of the outlet refrigerant of the rear seat side evaporator 27 disappears, and the rear seat side evaporator 27 The refrigerant at the outlet is in a saturated gas state determined by the ambient temperature. As a result, the temperature type expansion valve 28 of the rear seat air conditioning unit 26 is closed, and the refrigerant circulation to the rear seat evaporator 27 is forcibly stopped.
[0072]
In the next step S290, it is determined whether the discharge capacity of the compressor 11 is maximum. Specifically, it can be determined by the control current In that determines the target low pressure of the electromagnetic pressure control device in the capacity variable device 11b of the compressor 11 described in FIG. That is, when the control current In is equal to or greater than a predetermined value, the target low pressure is equal to or less than the predetermined value, and the discharge capacity of the compressor 11 is maximized. it can. If the discharge capacity of the compressor 11 is not in the maximum state, the process proceeds to step S300 to forcibly set the discharge capacity of the compressor 11 to the maximum state.
[0073]
When the defroster mode or the foot defroster mode is selected as described above and the outside air temperature is low, the refrigerant circulation to the rear seat evaporator 27 is forcibly stopped and the discharge capacity of the compressor 11 is forcibly stopped. Therefore, the refrigerant circulation flow rate to the front seat side evaporator 9 can be maximized, and as a result, the dehumidifying ability of the front seat side evaporator 9 can be maximized. Therefore, the fog removal of the vehicle window glass W in the defroster mode or the foot defroster mode can be quickly performed in a short time, and the vehicle front view can be secured quickly.
[0074]
(Other embodiments)
The present invention is not limited to the above-described embodiment and can be variously modified.
[0075]
(1) In the above-described embodiment, the case where there is one rear seat side air conditioning unit 26 has been described. However, in a vehicle having a large cabin space such as a bus, a plurality of rear seat side air conditioning units 26 are provided. In some cases, a plurality of rear seat evaporators 27 are connected in parallel. Thus, the present invention is similarly applied to a vehicle air conditioner in which a plurality of rear seat evaporators 27 are connected in parallel.
[0076]
{Circle around (2)} In the above-described embodiment, the rear seat side blower 29 is forcibly stopped at a low outside air temperature, thereby closing the rear seat side thermal expansion valve 28, thereby rear seat side evaporation. Although the refrigerant circulation to the evaporator 27 is forcibly stopped, an electric control valve such as an electromagnetic valve is provided in the refrigerant passage of the rear seat evaporator 27, and the electric control valve is closed at a low outside temperature. Then, the refrigerant circulation to the rear seat evaporator 27 may be forcibly stopped.
[0077]
(3) In the above-described embodiment, the variable displacement compressor 11 capable of changing the discharge capacity is used as the compressor 11. However, the compressor 11 has a fixed capacity in which the discharge capacity is fixed to a predetermined capacity. A mold compressor may be used. In this case, the operation of the fixed capacity compressor is intermittently performed, and the operation rate of the intermittent operation is changed to control the evaporator outlet temperature Te to be the target outlet temperature TEO. Therefore, by setting the target outlet temperature TEO to the lowest temperature near the freezing temperature of the evaporator condensate (around 3 to 4 ° C) at low outside air temperature, the operating rate of the intermittent compressor operation is increased and the front seat side evaporation The dehumidifying capacity of the vessel 9 can be increased.
[0078]
(4) In the above-described embodiment, the variable displacement compressor 11 driven by the vehicle engine is used as the compressor 11. However, the electric compressor is rotationally driven by an electric motor that operates using a vehicle-mounted battery as a power source. May be used. In this case, it is possible to control the rotation speed of the electric compressor, that is, the refrigerant discharge capacity by controlling the rotation speed of the electric motor so that the evaporator outlet temperature Te becomes the target outlet temperature TEO. Therefore, the dehumidifying capacity of the front seat side evaporator 9 can be increased by forcibly setting the rotational speed of the electric compressor to the maximum rotational speed at a low outside air temperature.
[0079]
(5) In the above-described embodiment, as the variable displacement compressor 11, the target pressure of the low pressure Ps is set by the control current In of the variable capacity device 11b as shown in FIG. 6 is used as the variable displacement compressor 11 by the control current In of the variable displacement device 11b, as shown in FIG. A flow rate Gro may be set to increase or decrease the discharge capacity so that the compressor discharge flow rate is maintained at the target flow rate Gro (discharge amount control type). This variable displacement compressor of the discharge amount control type is known from Japanese Patent Application Laid-Open No. 2001-107854.
[0080]
(6) In the above embodiment, the variable displacement compressor 11 is provided with the electromagnetic clutch 11a, and the operation of the compressor 11 is interrupted by intermittently energizing the electromagnetic clutch 11a. Since the compressor 11 reduces its discharge capacity to approximately 0%, the electromagnetic clutch 11a is eliminated, and the rotational power of the engine is always variable via pulleys, belts, etc. during operation of the vehicle engine. It may be transmitted to the mold compressor 11. In this case, when the air conditioner switch 42e of the front seat side air conditioning panel 42 is turned off, the discharge capacity of the variable capacity compressor 11 is maintained at a minimum capacity of approximately 0%, and the variable capacity compressor 11 is maintained. Is substantially stopped.
[0081]
(7) In the above-described embodiment, when the front seat side blowing mode is the defroster mode or the foot defroster mode and the ambient temperature is low, the refrigerant circulation flow rate to the front seat side evaporator 9 is maximized. However, since the foot defroster mode is less urgent for the fog removal of the vehicle window glass W than the defroster mode, the refrigerant circulation flow rate to the front seat side evaporator 9 is increased to the maximum. Therefore, the control may be performed only in the defroster mode and not performed in the foot defroster mode.
[0082]
(8) In the above-described embodiment, when the front seat side blowing mode is the defroster mode or the foot defroster mode and the outside air temperature is low, the display of the state in which the rear seat side blower 29 is forcibly stopped. Although not specifically described, display means (for example, an indicator lamp) for displaying the forced stop state of the rear seat side blower 29 may be provided on the rear seat side air conditioning panel 43.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of the overall configuration of a vehicle air conditioner showing an embodiment of the present invention.
FIG. 2 is a control characteristic diagram of a variable capacity compressor used in an embodiment of the present invention.
FIG. 3 is a schematic block diagram of an electric control unit according to an embodiment of the present invention.
FIG. 4 is a flowchart of capacity control of a variable capacity compressor according to an embodiment of the present invention.
FIG. 5 is a flowchart of air conditioning control according to an embodiment of the present invention.
FIG. 6 is a control characteristic diagram of another variable capacity compressor used in the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Front seat side air conditioning unit, 8 ... Front seat side blower, 9 ... Front seat side evaporator,
10 ... Refrigeration cycle, 11 ... Compressor, 26 ... Rear seat air conditioning unit,
27 ... rear seat side evaporator, 28 ... rear seat side expansion valve, 29 ... rear seat side blower.

Claims (6)

A front seat side air conditioning unit (1) for air conditioning the front seat side of the vehicle interior and a rear seat side air conditioning unit (26) for air conditioning the rear seat side of the vehicle interior;
The front seat side air conditioner unit (1) is provided with a front seat side evaporator (9) and a front seat side blower (8) for blowing air to the front seat side evaporator (9),
The rear seat side air conditioning unit (26) is provided with a rear seat side evaporator (27) and a rear seat side blower (29) for blowing air to the rear seat side evaporator (27),
The front seat evaporator (9) and the rear seat evaporator (27) are connected in parallel in the refrigeration cycle (10),
The front-seat-side air conditioning unit (1) is a blow-out mode in which a conditioned air is blown toward the front seat occupant's face, a foot mode in which the conditioned air is blown toward the front-seat occupant's feet, and the vehicle window glass side. At least the defroster mode that blows air-conditioned air is set,
The defroster mode is set as the blowing mode of the front seat side air conditioning unit (1) when the front seat side air conditioning unit (1) and the rear seat side air conditioning unit (26) are operated simultaneously and at a low outside temperature. When this is done, the vehicle air conditioner is characterized in that the refrigerant circulation to the rear seat evaporator (27) is stopped and the refrigerant circulation flow rate to the front seat evaporator (9) is increased. As a compressor of the refrigeration cycle (10), comprising a variable capacity compressor (11) for changing the discharge capacity,
The defroster mode is set as the blowing mode of the front seat side air conditioning unit (1) when the front seat side air conditioning unit (1) and the rear seat side air conditioning unit (26) are operated simultaneously and at a low outside temperature. 2. The vehicle air conditioner according to claim 1, wherein the discharge capacity of the variable capacity compressor (11) is set to a maximum capacity. A fixed capacity compressor (11) having a fixed discharge capacity as a compressor of the refrigeration cycle (10),
By controlling the operation of the fixed capacity compressor (11), the temperature (Te) of the front seat evaporator (9) is controlled to be the target temperature (TEO),
The defroster mode is set as the blowing mode of the front seat side air conditioning unit (1) when the front seat side air conditioning unit (1) and the rear seat side air conditioning unit (26) are operated simultaneously and at a low outside temperature. 2. The vehicle according to claim 1, wherein when the operation is performed, the operation of the fixed capacity compressor (11) is intermittently controlled by setting the target temperature (TEO) to a minimum temperature near a freezing temperature of condensed water. Air conditioner. The compressor of the refrigeration cycle (10) comprises an electric compressor (11) with adjustable rotation speed,
The defroster mode is set as the blowing mode of the front seat side air conditioning unit (1) when the front seat side air conditioning unit (1) and the rear seat side air conditioning unit (26) are operated simultaneously and at a low outside temperature. 2. The vehicle air conditioner according to claim 1, wherein when the electric compressor is operated, the rotational speed of the electric compressor is set to a maximum rotational speed. As a pressure reducing means for the refrigerant flowing into the rear seat evaporator (27), a temperature expansion valve (28) for adjusting the degree of superheat of the outlet refrigerant of the rear seat evaporator (27) is provided.
The defroster mode is set as the blowing mode of the front seat side air conditioning unit (1) when the front seat side air conditioning unit (1) and the rear seat side air conditioning unit (26) are operated simultaneously and at a low outside temperature. 5. The operation of the rear seat side blower (29) is stopped when the operation is performed, and the temperature type expansion valve (28) is closed. 6. Vehicle air conditioner. The front seat air conditioning unit (1) is configured to set a foot defroster mode that simultaneously blows substantially the same amount of conditioned air toward the foot portion side of the front seat occupant and the vehicle window glass side,
When the front seat air conditioning unit (1) and the rear seat air conditioning unit (26) are operated simultaneously and at a low outside air temperature, the foot defroster mode is used as the blowing mode of the front seat air conditioning unit (1). The refrigerant circulation flow to the front seat evaporator (9) is increased by stopping refrigerant circulation to the rear seat evaporator (27) even when set. The vehicle air conditioner as described in any one of thru | or 5.

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