JP3947671B2 - Air conditioner for vehicles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle air conditioner including a hybrid compressor capable of obtaining a driving force by a motor (engine) and an electric motor of a vehicle.
[0002]
[Prior art]
In a conventional vehicle air conditioner equipped with a hybrid compressor (for example, Japanese Patent Laid-Open No. 10-291415), the compressor driving method is limited by the operation / non-operation of the engine. Drive control considering power is not performed. Therefore, the situation where the power consumption of the vehicle air conditioner is large can be considered.
[0003]
[Problems to be solved by the invention]
When the compressor is driven by the engine, the rotational speed of the compressor depends on the rotational speed of the engine, and if the engine rotational speed increases, the rotational speed of the compressor similarly increases. When the rotation speed of the compressor becomes higher than necessary, the cooling capacity is adjusted by controlling the clutch on / off in the fixed capacity type compressor, and the compressor is restarted during this on / off control. Sometimes, there is a problem that a torque shock occurs when the clutch is engaged, or extra power is consumed to make a difference between the high pressure and the low pressure between the discharge side and the suction side.
[0004]
Therefore, an object of the present invention is to solve the above-described problems in a vehicle air conditioner equipped with a hybrid compressor, and particularly reduce the power consumption of the compressor when the vehicle is traveling at high speed (at high engine speed). And reducing torque shock due to clutch on / off control.
[0005]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, a vehicle air conditioner according to the present invention includes a hybrid compressor that uses an electric motor driven by power supply and a prime mover for driving the vehicle as a power source, and the power source for the compressor Compressor power source selection means capable of selecting either an electric motor or the prime mover, and refrigeration cycle heat load estimation means for estimating a heat load on the refrigeration cycle having a correlation with the power of the compressor In the vehicle air conditioner, the vehicle speed signal of the vehicle or the rotational speed signal of the prime mover is detected, the thermal load to the refrigeration cycle is estimated, and the compressor is driven by referring to the detected amount and the estimated value. As a criterion for selecting the drive source, as the heat load on the refrigeration cycle increases, the compressor drive source is moved forward from the prime mover. Rotational speed of the vehicle speed or the prime mover of the switching point is switched to the motor becomes a predetermined value such that the high speed, by preset criteria characteristic line extending continuously in order to partitioning the driving regions by the drive region and the electric motor by a motor And the predetermined value forming the judgment reference characteristic line is changed according to the type of physical quantity used for estimating the heat load to the refrigeration cycle, and the detected amount of the vehicle speed signal or the rotational speed signal of the prime mover is When the motor is larger than a predetermined value, the motor is selected as a drive source for the compressor. When the detected amount is equal to or smaller than the predetermined value and the motor is in a driving state, the motor is selected as the drive source for the compressor. It consists of what is characterized by.
[0006]
That is, in the vehicle air conditioner according to the present invention, when the vehicle speed is high or the rotational speed of the prime mover (engine rotational speed) is high, it is more efficient to drive the compressor with the electric motor than to drive the compressor with the prime mover. In this way, the power consumption is reduced by switching the power source in this way, and the generation of torque shock due to the clutch on / off control can be avoided by driving the motor.
[0007]
The air-conditioning system of this detects the rotational speed signal of the vehicle speed signal or engine, this detected value is larger than a predetermined value and selects the electric motor as a driving source of the compressor, sensing the amount of the predetermined When the prime mover is not more than the value and the prime mover is in a driving state, the prime mover is selected as a drive source for the compressor. However, the predetermined value can be changed according to the value of the heat load applied to the refrigeration cycle. .
[0008]
Further, in this vehicle air conditioner, a blower that blows air into the vehicle interior, an outside air temperature detection means that detects the outside air temperature, a vehicle interior air temperature detection means that detects the vehicle interior air temperature, and the evaporator outlet air An evaporator outlet air temperature detecting means for detecting the temperature, and an air volume detecting means for detecting a physical quantity correlated with the air volume of the blower, wherein the refrigeration cycle heat load estimating means is used for air conditioning the vehicle interior. When introducing the outside air into the ventilation duct through which air passes, the heat load on the refrigeration cycle is estimated from the outside air temperature, the evaporator outlet air temperature and the physical quantity, and the vehicle interior air is circulated into the ventilation duct. When the inside air is circulated, the heat load on the refrigeration cycle can be estimated from the cabin air temperature, the evaporator outlet air temperature, and the physical quantity.
[0009]
The refrigeration cycle heat load detecting means includes an outside air temperature detecting means for detecting the outside air temperature, and a solar radiation amount detecting means for detecting the amount of solar radiation. It is also possible to estimate the heat load on the cycle.
[0010]
Furthermore, the predetermined value is different between when the outside air is introduced into the ventilation duct through which air for air conditioning the vehicle interior passes and when the inside air is circulated through the ventilation duct. It can be set as follows.
[0011]
The vehicle air conditioner according to the present invention includes a hybrid compressor using a power source driven by power supply and a motor for driving the vehicle as a power source, and either the motor or the motor as a power source of the compressor. In a vehicle air conditioner comprising a compressor power source selecting means capable of selecting the vehicle interior air temperature detecting means for detecting a vehicle interior air temperature, the prime mover is selected as a power source for the compressor. When only the electric motor is selected as the power source of the compressor from the state in which the vehicle interior temperature TrO is detected, the vehicle interior temperature TrO is detected when only the motor is selected. When the pressure rises by more than Ty, the prime mover is selected as the power source for the compressor, and only the motor is selected as the power source for the compressor. If only the electric motor or between a state in which a power source is continued, the predetermined value Ty, 'and still set, the vehicle interior temperature is the predetermined value Ty than the TrO' smaller predetermined value Ty rose above At the time, the power source of the compressor may be switched to the prime mover . In other words, the optimum power source is selected based on the vehicle interior temperature based on the state of the power source used at that time, rather than judging based on the rotational speed or only the rotational speed.
[0012]
In this configuration, there is a state in which only the motor is used as a power source for a predetermined time or more from the time when only the motor is selected as the power source of the compressor from the state where the prime mover is selected as the power source of the compressor. If it continues, the predetermined value Ty can be updated to a more optimal switching condition by resetting it to a smaller value .
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a system configuration diagram of a vehicle air conditioner according to an embodiment of the present invention. The refrigeration cycle 1 is provided with a hybrid compressor 4 that uses either an engine 2 as a prime mover of a vehicle and an electric motor 5 (motor) driven by power supply, or both simultaneously as a power source. 2 is transmitted by the electromagnetic clutch 3. The high-temperature and high-pressure refrigerant compressed by the hybrid compressor 4 having the two drive sources is cooled by exchanging heat with the outside air by the condenser 6, and condensed and liquefied. Gas liquid is separated by the liquid receiver 7, and the liquid refrigerant is decompressed by the expansion valve 8. The decompressed low-pressure refrigerant flows into the evaporator 9 and exchanges heat with the air blown by the blower 12. The refrigerant evaporated and vaporized in the evaporator 9 is again sucked into the hybrid compressor 4 and compressed.
[0014]
The ventilation duct 13 through which air for air conditioning the vehicle passes is provided with a blower 12, an evaporator 9, an air mix damper 10, and a heater core 11. On the downstream side of the ventilation duct 13, blowout ports 41, 42, 43 such as DEF, VENT, and FOOT are provided, and a predetermined blowout port is selected by each damper (not shown). .
[0015]
As various sensors for air conditioning control, an evaporator outlet air temperature sensor 14 for detecting the air temperature Te after passing through the evaporator 9 is provided, and the detected signal is input to an air conditioning control device 15 that performs air conditioning control. The Further, the air conditioning controller 15 includes an outside air temperature Tam, an indoor air temperature Tr, a solar radiation amount Rsun, a heater hot water temperature Tw, a remaining battery charge Bt as electric power supply means (detected by the electric power source detection means), and an engine speed. Signal groups 16 such as a signal Ne, a vehicle speed signal SP, and an accelerator opening signal ACC are input. As output signals, an electric motor speed control signal 17 and a clutch control signal 18 are output.
[0016]
The air conditioning control device 15 also functions as a compressor power source selection means. When the hybrid compressor 4 is driven by the electric motor 5, the clutch 3 is turned off by the clutch control signal 18 and then the rotational speed of the electric motor 5 is reached. The rotational speed of the electric motor 5 is controlled by giving the control signal 17 as a duty signal. On the contrary, when the compressor 4 is driven by the engine 2, the output of the rotation speed control signal 17 of the electric motor 5 is stopped and the clutch 3 is turned on.
[0017]
In such a vehicle air conditioner, the air temperature Te after passing through the evaporator 9 is controlled by controlling the rotation speed of the motor 5 when the compressor is driven by the motor 5, and the clutch is turned on when the compressor is driven by the engine 2. / Off control or compressor capacity control.
[0018]
The various control modes will be described below.
<Switching conditions at high speed>
When the compressor is driven by the engine, when the vehicle travels at a high speed (for example, 80 km / h to 120 km / h), the rotational speed of the compressor increases as the rotational speed of the engine increases. In a fixed-volume compressor that controls the evaporator outlet air temperature by on / off control of the compressor clutch, as the rotational speed increases, the clutch on / off cycle becomes shorter, and the compressor is frequently stopped and restarted. The startup will be repeated. When the compressor is restarted, there is a problem that a torque shock is generated when the clutch is engaged, or excess power is consumed to make a difference between the high pressure and the low pressure on the discharge side and the suction side again. Therefore, during high-speed running where the cycle of clutch on / off control is shortened, if the compressor is driven by an electric motor, clutch on / off control is not performed. Increase can be prevented.
[0019]
Also, the compressor clutch on / off control is frequent not only when traveling at high speed but also when the refrigeration cycle heat load is low, such as when the outside air temperature is low. Therefore, an electric motor may be selected as the compressor drive source even under conditions where the refrigeration cycle heat load is low. Here, the refrigeration cycle heat load is a value having a correlation with the compressor power, and is estimated from the outside air temperature, the passenger compartment air temperature, the blower air volume, the inside / outside air switching mode, the evaporator outlet air temperature, the solar radiation amount, and the like. Value.
[0020]
As specific control, for example, as shown in FIG. 2, the vehicle speed at the switching point for switching to the electric motor may be set higher as the refrigeration cycle heat load increases. In FIG. 2, if the vehicle speeds at the switching points in certain refrigeration cycle heat loads q1 and q2 are respectively set as s1 and s2, the relationship of s1 ≧ s2 is established when q1> q2, and the smaller the refrigeration cycle heat load, Further, the condition is that the compressor is driven by the electric motor as the vehicle speed (or engine speed) increases.
[0021]
Here, by detecting three points of the outside air temperature Tam (when the outside air is introduced) or the vehicle interior air temperature Tr (when the inside air is circulated), the evaporator outlet air temperature Teva, and the blower voltage BLV, The load Q may be estimated.
(When introducing outside air) Q = f (Tam, Teva, BLV)
(At the time of inside air circulation) Q = f (Tr, Teva, BLV)
[0022]
Further, the refrigeration cycle heat load may be estimated from the outside air temperature and the amount of solar radiation. In this case, as shown in FIGS. 3A and 3B, the power source can be determined by changing the switching point according to the presence or absence of solar radiation. Further, since the refrigeration cycle heat load is different between the introduction of the outside air and the circulation of the inside air, the switching point may be changed depending on each circulation mode. Here, in FIG. 3, if the vehicle speeds at the switching points at a certain outside air temperature t1, t2 are respectively set as s1, s2, the relationship of s1 ≧ s2 is established when t1> t2, and the lower the outside air temperature is, the more the vehicle speed As the speed increases, the condition is that the compressor is driven by the electric motor.
[0023]
<Compressor power source switching control when vehicle is stopped>
When the vehicle is in an idling state, the driving force of the engine cannot be used when the engine is automatically stopped by the idling stop mechanism in a hybrid vehicle or the like. Therefore, the engine speed is detected, and when the engine speed is a predetermined value or less (for example, 1000 rpm or less), the compressor may be driven by an electric motor.
[0024]
<Prerequisites for using motor drive>
Basically, the compressor drive source is determined based on the switching conditions as described above. However, when the electric motor is used as the compressor drive source, the following conditions must be satisfied.
[0025]
<Switching conditions by refrigeration cycle heat load>
In summer, the temperature in the passenger compartment when the air conditioner is started is often 60 ° C to 70 ° C. Even after the air conditioner is activated, the seats, dashboards, etc. still have heat, and if the compressor capacity is insufficient, the room temperature may rise rapidly due to residual heat of the seats.
[0026]
Therefore, if only the electric motor is selected as the drive source for the compressor, the remaining heat of the seat is large, so if the room temperature suddenly rises, it is necessary to immediately select the engine as the compressor power source. . Therefore, when switching from the state where the engine is selected as the compressor power source to driving only the electric motor, the vehicle interior temperature Tr after the switching is the predetermined value Ty ° C. with respect to the vehicle interior temperature TrO at the moment of switching. The engine may be selected as the compressor power source when the temperature rises (for example, 5 ° C.) or more.
[0027]
Here, if the value of Ty is set too small, there is a possibility that the idle stop is canceled and the engine is operated every time a signal is waited.
[0028]
In addition, when the room temperature rises slowly while the compressor is driven only by the electric motor, if Ty is set to 5 ° C., for example, it takes time to rise 5 ° C. from the target room temperature, and the room temperature is higher than the target temperature. There is a risk that a high and unpleasant situation will last for a long time. Therefore, when a predetermined time (for example, 1 minute) has elapsed since the drive source is switched to the electric motor, the value of Ty is decreased by a predetermined value, for example, the setting is changed from 5 ° C. to 3 ° C. If the temperature rises by 3 ° C. or more from the temperature, the engine is switched to drive, so that an unpleasant situation in which the room temperature becomes 5 ° C. or more higher than the target temperature does not continue for a long time.
[0029]
【The invention's effect】
As described above, according to the vehicle air conditioner of the present invention, it is possible to reduce the power consumption of the compressor, particularly when traveling at a high speed, and to prevent a large torque shock that occurs at the time of high compressor rotation. It becomes possible.
[Brief description of the drawings]
FIG. 1 is a system configuration diagram of a vehicle air conditioner according to an embodiment of the present invention.
FIG. 2 is a relationship diagram between a vehicle speed and a heat load on a refrigeration cycle showing an example of a compressor power source switching condition.
FIG. 3 is a relationship diagram between a vehicle speed and an outside air temperature showing an example of a compressor power source switching condition depending on the presence or absence of solar radiation.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Refrigeration cycle 2 Engine 3 Electromagnetic clutch 4 Hybrid compressor 5 Electric motor 6 Condenser 7 Receiver 8 Expansion valve 9 Evaporator 10 Air mix damper 11 Heater core 12 Blower 13 Ventilation duct 14 Evaporator outlet air temperature sensor 15 Air-conditioning control device 16 Signal group 17 Motor rotation speed control signal 18 Clutch control signals 41, 42, 43

Claims (5)

A hybrid compressor using a motor driven by power supply and a motor for driving a vehicle as a power source, and a compressor power source capable of selecting either the motor or the motor as a power source of the compressor In a vehicle air conditioner comprising selection means and refrigeration cycle heat load estimation means for estimating a heat load on a refrigeration cycle having a correlation with the power of the compressor, a vehicle speed signal of the vehicle or a rotation speed signal of the prime mover is obtained. And detecting the heat load on the refrigeration cycle and referring to the detected amount and the estimated value to select a drive source of the compressor and use the refrigeration as a criterion for selecting the drive source. As the heat load on the cycle increases, the vehicle speed at the switching point for switching the compressor drive source from the prime mover to the motor or the rotational speed of the prime mover Of a predetermined value such that fast, set in advance the criteria characteristic line extending continuously in order to partitioning the driving regions by the drive area and the motor according to the prime mover, and wherein forming the criteria characteristic line When the predetermined value is changed according to the type of physical quantity used for estimating the heat load on the refrigeration cycle, and the detected amount of the vehicle speed signal or the rotational speed signal of the prime mover is larger than the predetermined value, the drive source of the compressor The motor is selected as above, and when the detected amount is not more than the predetermined value and the prime mover is in a driving state, the prime mover is selected as a drive source of the compressor. A blower for blowing air into the passenger compartment, an outside air temperature detecting means for detecting the outside air temperature, a passenger compartment air temperature detecting means for detecting the passenger compartment air temperature, and an evaporator outlet air temperature detection for detecting the evaporator outlet air temperature. And a blast amount detecting means for detecting a physical quantity correlated with the blast volume of the blower, wherein the refrigeration cycle heat load estimating means circulates outside air into the ventilation duct through which air for air conditioning the vehicle interior passes. When introducing outside air to be introduced, the heat load on the refrigeration cycle is estimated from the outside air temperature, the evaporator outlet air temperature and the physical quantity, and the inside air circulation for circulating the inside air into the ventilation duct is performed. The vehicle air conditioner according to claim 1 , wherein a heat load on the refrigeration cycle is estimated based on an outlet air temperature and the physical quantity. As the refrigeration cycle thermal load detection means, the refrigeration cycle thermal load detection means includes an outside air temperature detection means for detecting an outside air temperature and a solar radiation amount detection means for detecting the amount of solar radiation. and estimating the heat load on the air conditioner for a vehicle according to claim 1. The predetermined value is set to be different between when the outside air is introduced into the ventilation duct through which air for air-conditioning the vehicle interior passes and when the inside air is circulated in the ventilation duct. The vehicle air conditioner according to claim 1 or 3 , wherein A hybrid compressor using a motor driven by power supply and a motor for driving a vehicle as a power source, and a compressor power source capable of selecting either the motor or the motor as a power source of the compressor In a vehicle air conditioner comprising a selection means and a passenger compartment air temperature detection means for detecting a passenger compartment air temperature, from the state where the prime mover is selected as a power source of the compressor, the power source of the compressor When only the electric motor is selected, the vehicle interior temperature TrO at the time when only the electric motor is selected is detected. After that, when the vehicle interior temperature rises above the TrO by a predetermined value Ty or more, The motor is selected as a power source, and only the motor is used as a power source for a predetermined time or more from the time when only the motor is selected as the power source of the compressor. If the condition continues, the predetermined value Ty, 'and still set, the vehicle interior temperature is the predetermined value Ty than the TrO' smaller predetermined value Ty at the time of the rise above the power source of the compressor The vehicle air conditioner is switched to the prime mover .

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