JP3799768B2 - Refrigeration cycle equipment for vehicles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicular refrigeration cycle apparatus in which two main and sub evaporators are installed in parallel in one refrigeration cycle. For example, a front seat air conditioner that accommodates a main evaporator on the front side of a passenger compartment. It is suitable for use in a vehicle air conditioner in which a unit is disposed and a rear seat air conditioning unit that houses a sub-evaporator is disposed on the rear side of the vehicle interior.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a vehicle air conditioner in which a front seat air conditioning unit that houses a main evaporator is disposed on the front side of a vehicle interior, and a rear seat air conditioning unit that houses a sub-evaporator is disposed on the rear side of the vehicle interior. In order to improve the comfort of the interior space of the vehicle, it has been widely adopted. In this case, the air conditioning unit for the front seat is provided with a temperature adjusting means, for example, an air mix door for adjusting the air volume ratio between the cold air and the hot air. The air temperature is controlled.
[0003]
In the rear seat air conditioning unit, the capacity control by air volume control is generally used to reduce the size and simplification of the configuration. A device that performs control of the above is also known.
By the way, a temperature sensor for detecting the degree of cooling of the main evaporator (specifically, the air temperature immediately after the main evaporator is blown out) is installed in the front seat air conditioning unit, and the detection temperature of this temperature sensor is preset. The compressor is intermittently operated and the compressor discharge capacity is controlled so that the target temperature is maintained (the frost prevention temperature of the evaporator, specifically, around 0 to 3 ° C.). Thereby, the frost of an evaporator is prevented and the fall of the cooling performance of an evaporator is prevented.
[0004]
In addition, in the middle season of spring and autumn, the target temperature is corrected to a temperature that is higher than the target temperature on the low temperature side in summer by a predetermined value, and the compressor operation rate is reduced, or the compressor is operated at a low capacity. So-called economy control (power saving control) is implemented. Thereby, the power consumption of a compressor can be reduced.
[0005]
[Problems to be solved by the invention]
However, since the main and sub two evaporators are installed in parallel in the refrigeration cycle and the refrigerant discharged from one compressor is circulated to the two evaporators, for the above economy control, When the compressor operating rate is lowered or the compressor is operated at a low capacity, the refrigerant evaporation pressure in the sub-evaporator increases and the refrigerant evaporation temperature rises in conjunction with this. In this case, the refrigerant passage pressure loss to the rear-seat side sub-evaporator is larger than the front-seat side evaporator, and the refrigerant circulation amount to the rear-seat side sub-evaporator is small. As a result, the rear seat air conditioning unit is insufficiently cooled.
[0006]
Such a problem occurs in the same manner even when the refrigerator function is obtained by the cooling action of the sub-evaporator.
Accordingly, in view of the above points, the present invention provides a compressor in which two main and sub evaporators are installed in parallel in one refrigeration cycle, and the cooling degree of the main evaporator is maintained at a target temperature. In the refrigeration cycle apparatus for a vehicle that performs the operation control, the object is to eliminate the shortage of cooling on the side of the sub-evaporator accompanying the execution of economy control (power saving control).
[0007]
[Means for Solving the Problems]
As described above, in the invention according to claims 1 to 12, paying attention to the fact that the cooling on the sub-evaporator side is insufficient due to raising the target temperature of the cooling degree of the main evaporator at the time of economy control. The main evaporator (5) for cooling the main space side and the sub evaporator (6) for cooling the sub space side are provided in parallel so that the cooling degree of the main evaporator (5) is maintained at the target temperature. Furthermore, in the vehicle refrigeration cycle apparatus for controlling the operation of the compressor (2),
The target temperature of the degree of cooling of the main evaporator (5) is the target temperature (T on the low temperature side required for preventing the frost of the main evaporator (5)).₀) And the target temperature (T₀) The higher target temperature (T₁) And when the sub-evaporator (6) is operated, the target temperature (T₁) Is lowered to a predetermined level.
[0008]
According to this, when the economy control is performed when only the main evaporator (5) is operating, the target temperature for the degree of cooling of the main evaporator (5) is set to the target temperature on the high temperature side (T₁), The compressor (2) is operated at a low capacity, or the operating rate of the compressor (2) intermittent operation is reduced, and economy control (power saving control) is performed, and the compressor (2) Power consumption can be reduced.
[0009]
On the other hand, when the sub-evaporator (6) is operated simultaneously with the main evaporator (5), the target temperature (T on the high temperature side for economy control)₁) Is reduced to a predetermined level, the refrigerant evaporation temperature on the sub-evaporator side can be lowered, and insufficient cooling on the sub-evaporator side can be prevented.
Specifically, the main evaporator (5) is arranged and used in the front seat air conditioning unit (40) that air-conditions the space on the front seat side in the passenger compartment, and The sub-evaporator (6) is specifically used in the rear seat air conditioning unit (40) that air-conditions the space on the rear seat side in the vehicle interior.
[0010]
According to this, it is possible to effectively solve the lack of cooling on the rear seat side in the vehicle compartment during economy control.
Further, as in the invention of claim 4, a refrigerator (70) is disposed adjacent to the rear seat air conditioning unit (40), and the cold air cooled by the sub-evaporator (6) in the refrigerator (70). If a part of the engine is circulated, it is possible to effectively solve the insufficient cooling of the rear seat side and the insufficient cooling of the refrigerator (70) during the economy control.
[0011]
Moreover, like the invention of Claim 5, the main evaporator (5) is arrange | positioned as a cooling source of the air-conditioning unit (40) which air-conditions a vehicle interior space, A subevaporator (6) is arrange | positioned of a refrigerator (70). If it arrange | positions as a cooling source, when using a sub-evaporator (6) as a cooling source only for a refrigerator (70), the cooling shortage of a refrigerator (70) can be eliminated effectively.
In the present invention, the specific means for controlling the operation of the compressor (2) so that the degree of cooling of the main evaporator (5) is maintained at the target temperature is as in the invention described in claim 6. The compressor (2) is provided with a capacity variable mechanism (13, 16) that varies the capacity by an external control signal, and the capacity of the compressor (2) is variable by the capacity variable mechanism (13, 16). Alternatively, as in the invention described in claim 7, the compressor (2) is connected to the vehicle-mounted engine (12) via the electromagnetic clutch (10), and the compressor (2) is connected by the electromagnetic clutch (10). The operation may be interrupted.
[0012]
Further, the determination means (S110) for determining whether or not the sub-evaporator (6) is operated is based on opening and closing of the operation switch (67) of the rear seat air conditioning unit (42) as in the eighth aspect of the invention. A determination may be made.
Further, as in the ninth aspect of the invention, the target temperature is preferably corrected according to the outside air temperature.
[0013]
Further, as in the invention described in claim 10, in the predetermined region of the outside air temperature, the target temperature (T on the high temperature side)₁) For the target temperature (T₁) And the target temperature (T₀If the temperature is lowered to an intermediate temperature with the sub-evaporator (6), the power consumption can be reduced by the economy control (power-saving control) of the compressor (2) during the operation of the sub-evaporator (6). Both of the cooling effect can be demonstrated.
[0014]
Further, as in the invention described in claim 11, in a predetermined region of the outside air temperature, the target temperature (T on the high temperature side)₁) For the target temperature (T₀When the sub-evaporator (6) is operated, the cooling effect on the sub-evaporator (6) side can be maximized.
Further, as in the invention described in claim 12, when the outside air temperature is in the first predetermined region, the target temperature on the high temperature side (T₁) For the target temperature (T₁) And the target temperature (T₀) And intermediate temperature (T₂)
When the outside air temperature is in the second predetermined region on the higher temperature side than the first predetermined region, the target temperature (T on the high temperature side)₁) For the target temperature (T₀When the sub-evaporator (6) is operated, the power consumption is reduced by the economy control (power-saving control) of the compressor (2) in the first predetermined region when the sub-evaporator (6) is operated. Both the (6) side cooling effect can be ensured, while the sub-evaporator (6) side cooling effect can be maximized in the second predetermined region on the high temperature side.
[0015]
In addition, the code | symbol in the bracket | parenthesis of each said means shows a corresponding relationship with the specific means of embodiment description later mentioned.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is an overall configuration diagram of a first embodiment of the present invention. The present embodiment shows a refrigeration cycle apparatus applied to a vehicle air conditioner, and the refrigeration cycle 1 includes a compressor 2 that sucks, compresses, and discharges refrigerant. The high-temperature and high-pressure superheated gas refrigerant discharged from the compressor 2 flows into the condenser 3, where the refrigerant is cooled and condensed by exchanging heat with outside air blown from a cooling fan (not shown).
[0017]
The refrigerant condensed in the condenser 3 then flows into a liquid receiver (gas-liquid separator) 4 where the gas-liquid refrigerant is separated inside the liquid receiver 4, and surplus refrigerant (liquid refrigerant in the refrigeration cycle 1 is separated). ) Is stored in the liquid receiver 4. On the outlet side of the liquid receiver 4, refrigerant paths for the main evaporator 5 and the sub-evaporator 6 are provided in parallel.
That is, the liquid refrigerant from the liquid receiver 4 is decompressed to a low pressure by the main expansion valve (decompression means) 7 and enters a gas-liquid two-phase state, and then flows into the main evaporator 5 where it absorbs heat from the conditioned air. Then evaporate.
[0018]
An electromagnetic valve 8, a sub-expansion valve 9 and a sub-evaporator 6 are provided in series on the outlet side of the liquid receiver 4, and this series circuit is connected in parallel to the main expansion valve 7 and the main evaporator 5. Is provided.
Both the expansion valves 7 and 9 are temperature expansion valves having a temperature sensing part for sensing the temperature of the outlet refrigerant of the evaporators 5 and 6, and the degree of superheat of the outlet refrigerant of the evaporators 5 and 6 is set to a predetermined value. The valve opening (refrigerant flow rate) is adjusted so as to maintain the value. The above-described cycle components (2 to 9) are respectively coupled by refrigerant piping. The compressor 2 is a variable displacement type driven by the vehicle traveling engine 12 via the electromagnetic clutch 10, the belt 11, and the like, and includes an electromagnetic pressure control device 13 of a variable displacement mechanism.
[0019]
The electromagnetic valve 8, the electromagnetic clutch 10, and the electromagnetic pressure control device 13 are all connected to an air conditioning electronic control device (hereinafter referred to as ECU) 14, and the ECU 14 is a well-known CPU, ROM, RAM, and the like not shown. These microcomputers and their peripheral circuits are configured to perform arithmetic processing according to a preset program to control the operation of the above-described devices.
[0020]
When the electromagnetic clutch 10 is energized based on a control signal from the ECU 14, the electromagnetic clutch 10 enters a connected state, the power of the vehicle engine 12 is transmitted to the compressor 2, and the compressor 2 enters an operating state. On the other hand, when the energization of the electromagnetic clutch 10 is interrupted, the electromagnetic clutch 10 enters a disengaged state, and the compressor 2 stops.
Next, FIG. 2 shows an example of a specific structure of the compressor 2 and the electromagnetic clutch 10. The compressor 2 is a well-known wobble type. The power of the vehicle engine 12 is transmitted to the rotating shaft 15 of the compressor 2 via the electromagnetic clutch 10, and the rotating shaft 15 rotates. A swash plate 16 is connected to the rotary shaft 15 so as to be integrally rotatable. When the swash plate 16 rotates, the piston 17 reciprocates in the axial direction.
[0021]
Further, the displacement of the plurality of pistons 17 is changed by changing the inclination angle of the swash plate 16 to vary the discharge capacity (hereinafter simply referred to as capacity) of the compressor 2. Therefore, the swash plate 16 is swingably connected to the rotary shaft 15, and specifically, the swash plate 16 is supported by the spherical support portion 18 so as to be swingable. The inclination angle of the swash plate 16 depends on the pressure acting on the front and rear of the piston 17, that is, the pressure in the crank chamber 19 acting on the back surface of the piston 17, that is, the control pressure Pc, and the pressure in the cylinder 20 where the piston 17 reciprocates. It changes depending on the balance with (discharge pressure Pd and suction pressure Ps). Therefore, the inclination angle of the swash plate 16 can be changed by adjusting the control pressure Pc in the crank chamber 19.
[0022]
The gas refrigerant compressed by the cylinder 20 of the compressor 2 is discharged into the discharge chamber 21, and the gas refrigerant is discharged from here through the discharge port (not shown) to the condenser 3 side in FIG. The refrigerant is sucked into the cylinder 20 of the compressor 2 through the suction chamber 22. The suction chamber 22 communicates with the refrigerant outlet side of the main evaporator 5 and the sub-evaporator 6 in FIG. 1 through the suction port 22a.
[0023]
The pressure (control pressure) Pc in the crank chamber 19 is changed by the electromagnetic pressure control device 13 using the refrigerant discharge pressure Pd in the discharge chamber 21 and the refrigerant suction pressure Ps in the suction chamber 22. ing.
The electromagnetic pressure control device 13 includes a discharge pressure chamber 24 that communicates with the discharge chamber 21, a suction pressure chamber 25 that communicates with the suction chamber 22, and a control pressure chamber 26 that communicates with the crank chamber 19. It has been. The discharge pressure chamber 24 communicates with the control pressure chamber 26 via a variable throttle 28 whose opening degree is adjusted by a valve body 27. In the present example, the valve element 27 and the variable throttle 28 constitute a variable throttle mechanism. The suction pressure chamber 25 communicates with the control pressure chamber 26 via a fixed throttle 29. The communication relationship between these rooms is shown in FIGS.
[0024]
Further, a bellows (pressure responsive mechanism) 30 made of an expandable / contractible material is disposed inside the suction pressure chamber 25, and a predetermined internal pressure Pb is set in the bellows 30 in advance. The bellows 30 expands and contracts due to a change in the suction pressure Ps with respect to Pb. The valve element 27 is displaced via the rod 31 by the expansion and contraction of the bellows 30. The bellows 30 and the valve body 27 are also acted on by the electromagnetic force of the electromagnetic mechanism.
[0025]
In other words, the electromagnetic mechanism of this example includes an electromagnetic coil 32, a fixed magnetic pole member 33, and a movable magnetic pole member (plunger) that is attracted in the direction of the fixed magnetic pole member 33 (the direction in which the bellows 30 extends) by the electromagnetic force of the electromagnetic coil 32. 34 and a coil spring 35 that applies a spring force to the movable magnetic pole member 34. A rod 36 is connected to the center of the movable magnetic pole member 34. The rod 36, the valve body 27, and the rod 31 are connected together and displaced together.
[0026]
3 and 4 are schematic diagrams for explaining the operation of the electromagnetic pressure control device 13 described above, and the arrangement state of each part of the electromagnetic pressure control device 13 is different from that in FIG.
FIG. 3 shows a state where the capacity of the compressor 2 is increased. When the suction pressure Ps rises above the internal pressure Pb of the bellows 30 due to an increase in the cooling load, the bellows 30 contracts. 3A, the valve body 27 is displaced in the same direction, and the opening degree of the variable throttle 28 is decreased. Accordingly, the pressure loss between the discharge pressure chamber 24 and the control pressure chamber 26 increases, and the control pressure Pc in the control pressure chamber 26 decreases.
[0027]
Due to the decrease in the control pressure Pc, the pressure in the crank chamber 19 decreases and the back pressure of the piston 17 decreases, so that the swash plate 16 tilts as shown by the arrow (2) in FIG. The inclination angle θ of the plate 16 increases. As a result, the stroke of the piston 17 increases and the capacity of the compressor 2 increases. As a result, the cycle circulation refrigerant flow rate increases and the cooling capacity increases, so that the suction pressure Ps gradually decreases.
[0028]
When the suction pressure Ps is decreased below the internal pressure Pb of the bellows 30, the bellows 30 expands, so that the rods 31 and 36 move in the direction of the arrow (3) in FIG. 27 is displaced in the same direction to increase the opening of the variable throttle 28. Therefore, the pressure loss between the discharge pressure chamber 24 and the control pressure chamber 26 decreases, and the control pressure Pc in the control pressure chamber 26 increases.
[0029]
When the pressure in the crank chamber 19 increases due to the increase in the control pressure Pc, the swash plate 16 stands and the inclination angle θ of the swash plate 16 decreases as shown by the arrow (4) in FIG. The stroke of 17 is reduced and the capacity of the compressor 2 is reduced. As a result, the cycle circulation refrigerant flow rate decreases and the cooling capacity decreases, so the suction pressure Ps gradually increases.
[0030]
As described above, the bellows 30 expands and contracts in response to the change in the suction pressure Ps, so that the control pressure Pc is adjusted and the capacity of the compressor 2 is variably controlled. The set pressure of the suction pressure Ps is varied. The direction of the electromagnetic force of the electromagnetic coil 32 is a direction in which the bellows 30 extends, and therefore, the electromagnetic force of the electromagnetic coil 32 acts on the valve body 27 in the direction of increasing the opening degree of the variable throttle 28.
[0031]
On the other hand, since the electromagnetic force of the electromagnetic coil 32 is proportional to the control current In flowing through the electromagnetic coil 32, the control pressure Pc is increased by increasing the opening of the variable throttle 28 as the control current In increases. Reduce compressor capacity. Therefore, as shown in FIG. 5, the set pressure of the suction pressure Ps increases as the control current In increases. Thus, by changing the control current In, the suction pressure Ps changes and the evaporator blown air temperature can be adjusted.
[0032]
As can be understood from the above description of the variable capacity operation, in this embodiment, the swash plate 16 also serves as a variable capacity member, and this swash plate (capacity variable member) 16 and the electromagnetic pressure control device 13. Thus, a variable capacity mechanism is configured.
Next, FIG. 6 is an overall layout diagram showing a vehicle mounted state of the vehicle air conditioner provided with the refrigeration cycle apparatus of the present embodiment. The engine 12, the compressor 2, and the condenser described above are installed in the engine room 37 in front of the vehicle. 3, the liquid receiver 4 etc. are mounted.
[0033]
On the other hand, a front seat air conditioning unit 40 is disposed in an inner portion of a front instrument panel 39 in the passenger compartment 38, and a rear seat air conditioning unit 42 is disposed in a trunk room 41 behind the passenger compartment 38. Since both the front seat air conditioning unit 40 and the rear seat air conditioning unit 42 have known configurations, an outline thereof will be briefly described.
As shown in FIG. 7, the front seat air conditioning unit 40 is provided with a centrifugal blower 44 on the inlet side of the air conditioning case 43, and air in the vehicle compartment (inside air) drawn from a known inside / outside air switching box 45 or Air outside the passenger compartment (outside air) is blown through the air conditioning case 43 by the blower 44. The blown air passes through the main evaporator 5 and is cooled, and then the warm air that passes through the heating heat exchanger 47 by the air mix door (temperature control means) 46 and the cool air that passes through the bypass passage 47a. The air volume ratio between the warm air and the cool air is adjusted by the air mix door 46, and the temperature of the air blown into the passenger compartment is controlled.
[0034]
The hot air and the cold air are mixed in the air mixing chamber 48 to become air of a desired temperature, and are blown out into the vehicle interior through one or a plurality of blowing openings 52 to 54 selected by the blowing mode doors 49 to 51.
The heating heat exchanger 46 heats air using hot water (cooling water) from the vehicle engine 12 as a heat source. Of the blowout openings 52 to 54, the defroster blowout opening 52 is for blowing air to the inner surface of the windshield of the vehicle through the defroster duct 52a in FIG. 6, and the face blowout opening 53 is in FIG. It is for blowing air to the upper body of the passenger in the passenger compartment via the face duct 53a, and the foot outlet opening 54 is for blowing air to the passenger's feet in the passenger compartment.
[0035]
Further, an evaporator outlet temperature sensor (cooling degree detection means) comprising a thermistor for detecting an outlet air temperature immediately after passing through the evaporator 6 is provided in a portion of the air conditioning case 43 immediately after the air outlet of the main evaporator 5. 55 is provided.
FIG. 8 shows an outline of the rear seat air conditioning unit 42. A centrifugal blower 57 is provided at the outlet of the air conditioning case 56 of the rear seat air conditioning unit 42, and is provided on one end side of the air conditioning duct 56. The air in the rear part of the passenger compartment 38 is sucked from the suction port 58, and this suction air is passed through the air cleaning filter 59 and the sub-evaporator 6. Accordingly, the intake air is deodorized and dedusted by the air cleaning filter 59 and then cooled and dehumidified by the sub-evaporator 6.
[0036]
The cold air that has passed through the sub-evaporator 6 is introduced from the blow-out opening 60 into a pillar duct 61 (FIG. 6) at the rear of the vehicle disposed along the pillar at the rear of the vehicle, and downward from the ceiling at the rear of the vehicle by the pillar duct 61. It is blown out.
Next, the control system of the present embodiment will be described with reference to FIG. 1 described above. Various sensors for detecting information necessary for air conditioning control are connected to the input terminal of the ECU 14 in addition to the evaporator outlet temperature sensor 55. Is done. Specifically, a solar radiation sensor 62 that is a means for detecting the amount of solar radiation incident on the vehicle interior, an internal air sensor 63 that is a means for detecting the temperature inside the vehicle interior (inside air temperature), and a means for detecting the temperature outside the vehicle interior (outside air temperature). A certain outside air sensor 64 or the like is connected. In addition to this, the input terminal of the ECU 14 includes a front seat temperature setting device 65 for manually setting a desired temperature by the passenger in the vehicle, and an operation switch (for the front seat air conditioning unit 40). An auto air conditioner switch 66 and an operation switch 67 of the rear seat air conditioning unit 42 are connected.
[0037]
The signals from the sensors 55, 62 to 64, the front seat temperature setting device 65, the two operation switches 66, 67 and the like are A / D converted by an input circuit (not shown) in the ECU 14, and then the microcomputer. Is configured to be input to. The ECU 14 is supplied with power from an in-vehicle battery (not shown) when an ignition switch (not shown) of the engine 12 is turned on and an operation switch (automatic air conditioner switch) 66 of the front seat air conditioning unit 40 is turned on.
[0038]
Next, the operation of the present embodiment will be described. When the ignition switch of the vehicle engine 12 is turned on and the operation switch 66 of the front seat air conditioning unit 40 is turned on when the vehicle engine 12 is in an operating state, The electromagnetic clutch 10 is brought into a connected state by the ECU 14, and the compressor 2 is driven by the engine 12 to be in an operating state. Since the blower 44 of the front seat air conditioning unit 40 is also activated by the ECU 14, the air blown from the blower 44 is cooled by the main evaporator 5 of the front seat air conditioning unit 40 and becomes cold air.
[0039]
The cold air is reheated by the heating heat exchanger 47 by an amount determined by the opening degree of the air mix door 46, whereby the temperature of the air blown into the passenger compartment is changed to a target temperature (a target blown air temperature TAO described later). Can be adjusted. This temperature-adjusted air is blown out from any one or more of the blowout openings 52 to 54 into the vehicle interior.
In this state, when the operation switch 67 of the rear seat air conditioning unit 42 is turned on, the electromagnetic valve 8 is opened by the ECU 14, the refrigerant is circulated to the sub-evaporator 6, and the blower 57 is operated by the ECU 14. In this state, the cold air cooled by the sub-evaporator 6 blows out to the rear of the passenger compartment.
[0040]
Next, in this embodiment, the control process performed by the microcomputer of ECU14 is demonstrated concretely based on the flowchart of FIG.
First, when the ignition switch of the vehicle engine 12 is turned on and the operation switch 66 of the front seat air conditioning unit 40 is turned on, the control routine of FIG. 9 is started. In step S100, the values of the sensors 55 and 62 to 64 are read, and signals from the front seat temperature setting unit 65, the operation switch 67 of the rear seat air conditioning unit 42, and the like are read.
[0041]
In the next step S110, it is determined whether or not the operation switch 67 of the rear seat air conditioning unit 42 is in the ON (closed) state. If the operation switch 67 is in the ON state, the process proceeds to step S120, and the broken line in FIG. 1st target evaporator blowing air temperature TEO determined from the characteristic (map) a to show₁To decide. When the operation switch 67 is in the OFF state, the process proceeds to step S130, and the first target evaporator blown air temperature TEO determined from the characteristic (map) b shown by the solid line in FIG.₁To decide.
[0042]
Here, the broken line characteristic a and the solid line characteristic b in FIG. 10 are preset and stored in the ROM of the microcomputer, and the first target evaporator outlet temperature TEO₁Is determined corresponding to the outside air temperature Tam. That is, the solid line characteristic b, which is a characteristic when the rear seat air conditioning unit 42 is not operated (only the front seat air conditioning unit 40 is operated), is an intermediate temperature range of the outside air temperature Tam (in the example of FIG. Since the necessity for cooling and dehumidification decreases at ° C), the first target evaporator outlet temperature TEO₁The target temperature T on the high temperature side₁(In the example of FIG. 10, it is corrected to 12 ° C.). This is to perform economy control (power saving control) by reducing the capacity of the compressor 2, as will be described later.
[0043]
On the other hand, the first target evaporator outlet temperature TEO is used to ensure cooling capacity at high temperatures in summer when the outside air temperature Tam exceeds 25 ° C.₁Is the target temperature T on the high temperature side in inverse proportion to the increase in the outside air temperature Tam₁Gradually decreases. On the other hand, in the low temperature range where the outside air temperature Tam is lower than 17 ° C., the first target evaporator outlet temperature TEO is used in order to ensure the dehumidifying ability to prevent fogging of the window glass.₁Decreases as the outside air temperature Tam decreases.
[0044]
On the contrary, the broken line characteristic a which is the characteristic at the time of the operation of the air conditioning unit 42 for the rear seat is the solid line characteristic b in the intermediate temperature range of the outside air temperature Tam (10 ° C. to 25 ° C. in the example of FIG. 10). Than the first target evaporator outlet temperature TEO₁Is lowered by a predetermined value.
In the characteristics of FIG. 10, TEO is used to prevent frost in the main evaporator 5.₁Minimum target temperature T on the low temperature side₀Is 0 ° C.
[0045]
As described above, the first target evaporator outlet temperature TEO corresponds to whether the operation switch 67 of the rear seat air conditioning unit 42 is on or off, that is, whether the rear seat air conditioning unit 42 is operated.₁Is determined by either the broken line characteristic a or the solid line characteristic b in FIG.
Next, the process proceeds to step S140, and based on the sensor value read in step S100, a target blowing temperature TAO (hereinafter referred to as TAO) that is a target temperature of the conditioned air blown out to the front seat side of the vehicle interior according to the following formula 1. Is calculated (determined).
[0046]
[Expression 1]
TAO = Tset * Kset-Tr * Kr-Tam * Kam-Ts * Ks + C
Tset: set temperature of front seat temperature setting device 65
Tr: The inside air temperature detected by the inside air sensor 63
Tam: outside air temperature detected by the outside air sensor 64
Ts: amount of solar radiation detected by the solar radiation sensor 62
Kset, Kr, Kam, Ks: Control gain
C: Constant
In the next step S150, the second target evaporator outlet temperature TEO₂To decide. This second target evaporator outlet temperature TEO₂As shown in FIG. 11, it is performed based on the TAO.
[0047]
That is, FIG. 11 is a characteristic (map) preset and stored in the ROM of the microcomputer. Based on this map, the higher the TAO, the higher the second target evaporator outlet temperature TEO.₂Determine to be higher. In the region where TAO is higher than 26 ° C, TAO is set at a high temperature target temperature T which is constant at 12 ° C.₁To keep in. Also in the characteristics of FIG.₂Minimum target temperature T on the low temperature side₀Is 0 ° C.
[0048]
In the next step S160, the first and second target evaporator outlet temperatures TEO₁, TEO₂Are compared, and the smaller target evaporator outlet temperature is selected as the final target evaporator outlet temperature TEO. That is, TEO₁Is TEO₂When it is smaller, the process proceeds to step S170, and the actual main evaporator outlet temperature TE detected by the main evaporator outlet temperature sensor 55 and the first target evaporator outlet temperature TEO.₁And TE = TEO₁A control current value In is determined.
[0049]
Specifically, in step S170, the control current value In of the electromagnetic coil 32 of the electromagnetic pressure control device 13 is calculated and output based on the following formulas 2 and 3. The feedback control according to Equations 2 and 3 is proportional-integral control (PI control).
[0050]
[Expression 2]
En = TE-TEO₁
[0051]
[Equation 3]
In = In-1-Kp {(En-En-1) +. Theta./Ti.En}
However, En: Evaporator outlet temperature deviation
Kp: proportionality constant
θ: Sampling time
Ti: integration time
In the electromagnetic pressure control device 13, the set pressure of the suction pressure Ps is determined according to the control current value In calculated as described above, and the capacity of the compressor 2 is variably controlled so as to be the set pressure. As a result, the actual evaporator outlet temperature TE is the first target evaporator outlet temperature TEO.₁Maintained.
[0052]
In the determination of step S160, TEO₁Than TEO₂When is smaller, the process proceeds to step S180, where the actual main evaporator outlet temperature TE and the second target evaporator outlet temperature TEO.₂And TE = TEO₂A control current value In is determined. And the capacity | capacitance of the compressor 2 is variably controlled based on this control electric current value In, As a result, the actual evaporator blowing temperature TE becomes 2nd target evaporator blowing temperature TEO.₂Maintained.
[0053]
By the way, as shown in FIG. 10, when only the front seat air conditioning unit 40 is operating in the intermediate temperature range (17 ° C. to 25 ° C.) of the outside air temperature, the first target evaporator blowout is performed by the solid line characteristic b. Temperature TEO₁Set temperature T on the high temperature side₁(For example, it is corrected to 12 ° C.), so that the capacity of the compressor 2 can be reduced and the compressor driving power of the engine 12 can be reduced.
[0054]
On the other hand, when the rear seat air conditioning unit 42 is also operating, the first target evaporator blowout is performed in the first predetermined temperature range (less than 10 ° C to less than 23 ° C) of the outside air temperature by the broken line characteristic a of FIG. Temperature TEO₁Set temperature T on the high temperature side₁And low temperature set temperature T₀Intermediate temperature T between₂(For example, 5 ° C). This TEO₁Since the capacity of the compressor 2 is increased by lowering, the refrigerant evaporation pressure (suction pressure Ps) in both the evaporators 5 and 6 becomes lower than in the case of the solid line characteristic b. Thereby, since the refrigerant | coolant evaporation temperature in both the evaporators 5 and 6 becomes low, lack of the air_conditioning | cooling capability in the air conditioning unit 42 for rear seats can be prevented.
[0055]
Furthermore, in the second predetermined temperature range (25 ° C. to 35 ° C.) higher than the first predetermined temperature range, the first target evaporator outlet temperature TEO.₁Set temperature T on the low temperature side₀And the same level (0 ° C). Thereby, the cooling capacity of the rear seat air conditioning unit 42 on the high temperature side can be further enhanced.
In FIG. 1, function realizing means corresponding to each step of the flowchart shown in FIG. 9 is shown as a block diagram in the ECU 14.
[0056]
(Second Embodiment)
FIG. 12 shows the second embodiment, and the first target evaporator outlet temperature TEO.₁The broken line characteristic a when the rear seat air conditioning unit is operated is changed as shown in FIG. 12, and the first target evaporator outlet temperature TEO is changed.₁Is expanded to a range of 10 ° C to 30 ° C in the intermediate temperature range of the outside air temperature.
[0057]
According to the first embodiment, in the second predetermined temperature range (25 ° C. to 35 ° C.) on the high temperature side of the outside air temperature, the first target evaporator outlet temperature TEO.₁Set temperature T on the low temperature side₀Is reduced to the same level (0 ° C.), the capacity of the compressor 2 is increased and the compressor driving power is increased. However, according to the second embodiment, the outside air temperature is the second predetermined temperature range ( 25 ° C to 35 ° C) when the first target evaporator outlet temperature TEO₁Intermediate temperature T of 5 ° C₂Therefore, the capacity of the compressor 2 is reduced as compared with the first embodiment, and the compressor driving power can be reduced.
[0058]
That is, the period during which power saving of the engine 12 can be achieved with respect to changes in the outside air temperature becomes longer, and the power saving effect can be increased.
(Third embodiment)
FIG. 13 shows the third embodiment, and the first target evaporator outlet temperature TEO.₁The broken line characteristic a at the time of operation of the rear seat air conditioning unit is changed as shown in FIG. 13, and the first target evaporator outlet temperature TEO in the entire range of 5 ° C. to 35 ° C. of the outside air temperature.₁Low temperature side target temperature T₀And the same level (0 ° C). Therefore, when the rear seat air conditioning unit is in operation, the power saving effect by the economy control cannot be exhibited, but the cooling capacity of the rear seat air conditioning unit 42 can always be maximized.
[0059]
(Fourth embodiment)
FIG. 14 shows a fourth embodiment, and in a first predetermined temperature range from a low temperature range to an intermediate temperature range (for example, 20 ° C.), the first target evaporator outlet temperature TEO.₁The broken line characteristic a when the rear seat air conditioning unit is operated is set to the same characteristic as the solid line characteristic b (when only the front seat air conditioning unit 40 is operated), and the power saving effect by economy control is exhibited.
[0060]
On the other hand, in the second predetermined temperature range from the intermediate temperature range of the outside air temperature to the high temperature range (for example, the outside air temperature = 20 ° C. to 35 ° C. range), the broken line characteristic a is lowered from the solid line characteristic b. According to this, in the second predetermined temperature range from the intermediate temperature range to the high temperature range of the outside air temperature, the refrigerant evaporation temperature in both the evaporators 5 and 6 becomes low, and in particular, the lack of the cooling capacity in the rear seat air conditioning unit 42 is effective. And can improve the cooling feeling of the passenger compartment at high temperatures.
[0061]
(Fifth embodiment)
15 and 16 show a fifth embodiment. In the first embodiment described above, as shown in FIG. 8, in the rear seat air conditioning unit 42, the sub-evaporator 6 is used only for cooling the cold air blown into the vehicle interior, but in the fifth embodiment, The sub-evaporator 6 is also used for cooling the refrigerator 70.
[0062]
That is, in the fifth embodiment, the refrigerator 70 is arranged adjacent to the side of the rear seat air conditioning unit 42 (the side in the vehicle left-right direction). The intake side duct 71 of the refrigerator 70 communicates with the blowout side of the centrifugal blower 57, and the exhaust side duct 72 of the refrigerator 70 communicates with the suction side of the blower 57. Thereby, the air blown from the blower 57 circulates in the refrigerator 70 along the path indicated by the arrow A in FIG.
[0063]
Here, the path of arrow A flows by bypassing the sub-evaporator 6 in the rear seat air conditioning unit 42, but in the blower 57, the reflux air from the refrigerator 70 and the cold air that has passed through the sub-evaporator 6 are mixed. Therefore, the inside of the refrigerator 70 can be cooled by circulating low-temperature air through the path indicated by the arrow A in the refrigerator 70.
In addition, since the door 73 is rotatably provided in the exit part of the exhaust side duct 72, when not using the refrigerator 61, the door 73 is operated to the obstruction | occlusion position 73a (FIG. 16) of the exhaust side duct 72. It is only necessary to stop the air circulation along the route indicated by the arrow A.
[0064]
Moreover, in this example, the 1st blowing opening part 60 and the 2nd blowing opening part 60a are provided as a blowing opening part provided in the blowing side of the air blower 57, and two places (for example, the ceiling side of a vehicle rear part and the vehicle side rear part) are provided. Cold air is blown out to the seat section of the rear seat).
(Other embodiments)
(1) In the fifth embodiment, the refrigerator 70 is disposed adjacent to the rear seat air conditioning unit 42 and the sub-evaporator 6 of the rear seat air conditioning unit 42 is also used for cooling the refrigerator 70. The seat air conditioning unit 42 may be eliminated and the sub-evaporator 6 may be installed exclusively for cooling the refrigerator 70. That is, the present invention can be similarly implemented in a refrigeration cycle apparatus in which a main evaporator 5 for air conditioning and a sub-evaporator 6 for refrigerator are installed in parallel.
[0065]
(2) In the first embodiment, the case where the capacity of the compressor 2 is controlled for controlling the blown air temperature (cooling degree) of the main evaporator 5 has been described. However, the compressor 2 is of a fixed capacity type. May be used to control the blown air temperature (cooling degree) of the main evaporator 5 by intermittently controlling the electromagnetic clutch 10 to intermittently operate the compressor 2. Since such a temperature (cooling degree) control method is well known, detailed description thereof is omitted.
[0066]
(3) In the first embodiment, the evaporator outlet temperature TE is detected as a physical quantity related to the degree of cooling of the main evaporator 5, but the suction pressure of the compressor 2 is used instead of the evaporator outlet temperature TE. The control of the flowchart of FIG. 9 can also be performed by detecting Ps, the surface temperature of the main evaporator 5, the refrigerant evaporation temperature of the main evaporator 5, or the like.
(4) In the first embodiment, the electromagnetic pressure control device 13 is used as the capacity variable mechanism of the compressor 2, but an actuator such as a servo motor is used without using the electromagnetic pressure control device 13. Thus, a mechanism for directly driving and controlling the capacity variable member can be used. In addition, the capacity variable mechanism of the compressor 2 is not limited to the mechanism that changes the inclination angle of the swash plate 16, and the present invention can be applied to various known mechanisms as well.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of a refrigeration cycle apparatus for vehicle air conditioning according to a first embodiment of the present invention.
FIG. 2 is a longitudinal sectional view of the variable capacity compressor in the first embodiment.
FIG. 3 is a schematic diagram for explaining the operation of the compressor of FIG. 2 at a large capacity.
FIG. 4 is a schematic diagram for explaining the operation of the compressor of FIG. 2 when the capacity is small.
5 is a characteristic diagram showing the relationship between the control current In and the set pressure of the suction pressure Ps of the electromagnetic pressure control device installed in the compressor of FIG. 2;
FIG. 6 is a perspective view showing a vehicle mounted state of the vehicle air conditioner in the first embodiment.
7 is a schematic cross-sectional view of the front seat air conditioning unit of FIG. 6. FIG.
8 is a schematic cross-sectional view of the rear seat air conditioning unit of FIG. 6;
FIG. 9 is a flowchart showing a control process of the first embodiment.
FIG. 10 shows a first target evaporator outlet temperature TEO in the first embodiment.₁It is a characteristic view which shows the correlation with the outside temperature Tam.
FIG. 11 shows a target outlet temperature TAO and a second target evaporator outlet temperature TEO in the first embodiment.₁It is a characteristic view which shows correlation with these.
FIG. 12 shows a first target evaporator outlet temperature TEO in the second embodiment.₁It is a characteristic view which shows the correlation with the outside temperature Tam.
FIG. 13 shows a first target evaporator outlet temperature TEO in the third embodiment.₁It is a characteristic view which shows the correlation with the outside temperature Tam.
FIG. 14 shows a first target evaporator outlet temperature TEO in the fourth embodiment.₁It is a characteristic view which shows the correlation with the outside temperature Tam.
FIG. 15 is a schematic top view of a rear seat air conditioning unit according to a fifth embodiment, a part of which is a cross-sectional view.
FIG. 16 is a schematic longitudinal sectional view of a rear seat air conditioning unit according to a fifth embodiment.
[Explanation of symbols]
2 ... Compressor, 5 ... Main evaporator, 6 ... Sub-evaporator, 13 ... Electromagnetic pressure control device,
16 ... Swash plate, 40 ... Air conditioning unit for front seats, 42 ... Air conditioning unit for rear seats,
55. Evaporator outlet temperature sensor (cooling degree detection means).

Claims (12)

A main evaporator (5) for cooling the main space side;
A sub-evaporator (6) that is provided in parallel with the main evaporator (5) and cools the sub-space side;
A compressor (2) for compressing and discharging the gas refrigerant evaporated in the main evaporator (5) and the sub-evaporator (6),
In the vehicle refrigeration cycle apparatus for controlling the operation of the compressor (2) such that the degree of cooling of the main evaporator (5) is maintained at a target temperature,
Target temperature of the cooling degree of the main evaporator (5), and the main evaporator (5) low-temperature side of the target temperature required for the prevention of Frost (T _0), the target temperature of the low temperature side (T ₀ ) It can be corrected between the higher target temperature (T ₁ ) on the higher temperature side,
A vehicular refrigeration cycle apparatus wherein the high temperature side target temperature (T ₁ ) is lowered to a predetermined level when the sub-evaporator (6) is operated. A main evaporator (5) for cooling the main space side;
A sub-evaporator (6) that is provided in parallel with the main evaporator (5) and cools the sub-space side;
A compressor (2) that compresses and discharges the gas refrigerant evaporated in the main evaporator (5) and the sub-evaporator (6);
A cooling degree detecting means (55) for detecting the cooling degree of the main evaporator (5);
Target temperature determining means (S120, S130, S150, S160) for determining a target temperature of the degree of cooling of the main evaporator (5);
Control means (S170, S180) for controlling the operation of the compressor (2) such that the actual cooling degree of the main evaporator (5) is maintained at the target temperature;
Determination means (S110) for determining whether the sub-evaporator (6) is activated or not,
The target temperature determining means sets the target temperature to a lower target temperature (T ₀ ) necessary for preventing frost of the main evaporator (6) and a higher temperature than the lower target temperature (T ₀ ). It can be corrected between the target temperature (T ₁ ) on the side,
When the operating state of the sub-evaporator (6) is determined by the determining means (S110), the target temperature (T ₁ ) on the high temperature side is lowered to a predetermined level by the target temperature determining means. A refrigeration cycle apparatus for vehicles characterized by the above. The main evaporator (5) is disposed in a front seat air conditioning unit (40) that air-conditions the space on the front seat side in the passenger compartment,
The vehicle refrigeration cycle according to claim 1 or 2, wherein the sub-evaporator (6) is disposed in a rear seat air conditioning unit (42) for air-conditioning a space on the rear seat side of the vehicle interior. apparatus. A refrigerator (70) is arranged adjacent to the rear seat air conditioning unit (42), and a part of the cold air cooled by the sub-evaporator (6) circulates in the refrigerator (70). The vehicular refrigeration cycle apparatus according to claim 3. The main evaporator (5) is disposed as a cooling source of an air conditioning unit (40) for air-conditioning the vehicle interior space,
The refrigeration cycle device for vehicles according to claim 1 or 2, wherein said sub-evaporator (6) is arranged as a cooling source of a refrigerator (70). The compressor (2) includes a variable capacity mechanism (13, 16) that varies the capacity by an external control signal.
The capacity of the compressor (2) is varied by the capacity variable mechanism (13, 16) so that the cooling degree of the main evaporator (5) is maintained at the target temperature. The vehicle refrigeration cycle apparatus according to any one of claims 1 to 5. The compressor (2) is connected to an in-vehicle engine (12) via an electromagnetic clutch (10),
2. The cooling degree of the main evaporator (5) is maintained at the target temperature by intermittently operating the compressor (2) by the electromagnetic clutch (10). The refrigeration cycle apparatus for vehicles as described in any one of thru | or 5. The determination means (S110) determines whether or not the sub-evaporator (6) is operated based on opening and closing of an operation switch (67) of the rear seat air conditioning unit (42). 4. The vehicle refrigeration cycle apparatus according to 4. The vehicular refrigeration cycle apparatus according to any one of claims 1 to 8, wherein the target temperature is corrected according to an outside air temperature. In a predetermined area of the outside temperature, the hot side of the target temperature (T _1), to an intermediate temperature (T ₂₎ with the hot side of the target temperature (T ₁₎ and the cold side of the target temperature (T ₀₎ The vehicular refrigeration cycle apparatus according to claim 9, wherein the vehicular refrigeration cycle apparatus is pulled down. 10. The vehicle according to claim 9, wherein, in a predetermined region of the outside air temperature, the high temperature side target temperature (T ₁ ) is lowered to a level equivalent to the low temperature side target temperature (T ₀ ). Refrigeration cycle equipment. When the outside temperature is in the first predetermined region, intermediate the hot side of the target temperature (T _1), and the hot side of the target temperature (T ₁₎ and the cold side of the target temperature (T ₀₎ While reducing to temperature (T ₂ ),
When the outside air temperature is in the second predetermined region on the higher temperature side than the first predetermined region, the target temperature (T ₁ ) on the high temperature side is equal to the target temperature (T ₀ ) on the low temperature side. The vehicular refrigeration cycle apparatus according to claim 9, wherein the refrigeration cycle apparatus for the vehicle according to claim 9 is lowered.

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