JP3931433B2 - Air conditioner for vehicles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle air conditioner equipped with a compressor that can be driven by one of an engine and an electric motor, and more particularly to control of a cooling fan that cools a radiator and a condenser.
[0002]
[Prior art]
The cooling fan that cools the radiator and condenser is controlled by the engine water temperature and the refrigerant pressure value on the high-pressure side of the refrigeration cycle (hereinafter referred to as high pressure). When the water temperature or high pressure exceeds the reference value, the cooling fan drive voltage is set to Hi. When the water temperature and high pressure were both low, the cooling fan drive voltage was set to Low or OFF.
[0003]
[Problems to be solved by the invention]
However, in hybrid vehicles and eco-run vehicles in which an air conditioner is operated by an electric motor even when the engine is stopped, the drive voltage of the cooling fan may be set to Hi even when the engine is stopped.
On the other hand, the power consumption (power consumption) of the compressor is a characteristic that rises to the left, and the power consumption of the cooling fan is a characteristic that rises to the right, so there is an optimum operating point that minimizes the power consumption of the entire air conditioning system To do.
[0004]
Here, when the compressor is driven by an electric motor (hereinafter, when the motor is driven), the energy generated by the engine is stored in a battery and the electric motor is driven by the electric power. Then, the power consumption of the compressor is larger than when the compressor is driven by the engine (hereinafter, when the engine is driven) (see FIG. 5A), and the characteristic of rising to the left becomes remarkable.
Therefore, as shown in FIG. 5B, the optimum operating point A when the engine is driven differs from the optimum operating point B when the motor is driven.
[0005]
However, since the conventional cooling fan control was performed in the same way as when the engine was driven when the motor was driven, the power consumption of the entire air conditioning system moved away from the minimum optimum operating point when the motor was driven. In addition, extra power is consumed when the motor is driven. For this reason, when the motor is driven by battery power, the duration time is shortened.
[0006]
OBJECT OF THE INVENTION
The present invention has been made in view of the above circumstances, and an object of the present invention is to reduce power consumption at the time of driving a motor in a vehicle air conditioner in which an air conditioner is operated by an electric motor even when the engine is stopped. It is in the provision of the vehicle air conditioner which can suppress consumption.
[0010]
[ Means for Solving the Problems ]
[Means of Claim 1 ]
By increasing the drive output of the cooling fan when the motor is driven compared to when the engine is driven, the power consumption of the entire air conditioning system when the motor is driven can be set to the minimum optimum operating point.
[0011]
[Means of claim 2 ]
By increasing the drive voltage of the cooling fan when the motor is driven as compared with when the engine is driven, the power consumption of the entire air conditioning system when the motor is driven can be set to the minimum optimum operating point.
[0012]
[Means of claim 3 ]
By setting the reference value at which the cooling fan switches to a higher output when the motor is driven than when the engine is driven, the power consumption of the entire air conditioning system when the motor is driven can be brought closer to the minimum optimum operating point.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described based on examples and modifications.
[Configuration of Example]
The vehicle air conditioner will be described with reference to the block diagram of FIG.
The vehicle air conditioner is equipped with a known refrigeration cycle, and the refrigeration cycle includes a compressor 1. When the compressor 1 is driven to rotate, the refrigerant is sucked, compressed, and discharged to operate the refrigeration cycle.
[0014]
As a drive source of the compressor 1, an engine 2 for driving the vehicle and an electric motor 3 are provided.
The rotational torque generated by the engine 2 is connected or disconnected by a clutch 4 provided between the compressor 1 and the engine 2.
The electric motor 3 generates rotational torque when energized, and the rotational torque generated by the electric motor 3 is transmitted to the compressor 1 directly or via a planetary gear or the like.
The clutch 4 is energized and controlled by the air conditioning controller 6 via the clutch driving means 5, and the electric motor 3 is energized and controlled by the air conditioning controller 6 via the motor driving means 7.
[0015]
The vehicle has a condenser fan 8 (corresponding to a cooling fan, for reference to FIGS. 2 to 4) for cooling the condenser of the refrigeration cycle, and a radiator fan 9 (corresponding to a cooling fan for cooling the radiator). The condenser fan 8 and the radiator fan 9 are energized and controlled by the air conditioning control device 6 via the fan driving means 10.
[0016]
The air conditioning control device 6 inputs a signal from the engine control unit 11 that controls the engine 2 and a signal from the vehicle state detection means 12 that detects the state of the vehicle. The air conditioning control device 6 includes an engine state determination unit 13 that determines an operation state of the engine 2 based on a signal from the engine control unit 11 and a signal from the vehicle state detection unit 12.
Further, the air conditioning control device 6 includes a drive selection unit 14 that selects a drive source of the compressor 1 based on the determination of the engine state determination unit 13.
Further, the air conditioning control device 6 includes a fan control unit 15 that controls the rotational speed of the condenser fan 8 and the radiator fan 9 according to the engine water temperature and the high pressure.
[0017]
Next, an energization control circuit for the capacitor fan 8 and the radiator fan 9 will be described with reference to FIGS.
The basic operation of the fan control unit 15 is to switch the driving voltage of the condenser fan 8 and the radiator fan 9 from Low (6V) to Hi (12V) when the engine water temperature is higher than a predetermined temperature or when the high pressure is higher than a predetermined pressure. Is.
The fan control unit 15 corresponds to a fan control unit, and controls the drive output of the condenser fan 8 and the radiator fan 9 by changing the engine driving and the motor driving. Specifically, the reference value for switching to high output (Hi) is set lower when the motor is driven than when the engine is driven.
[0018]
Here, each symbol shown in the electric circuit will be described.
BAT is a battery, IGSW is an ignition switch, and A / CR is an air conditioner relay that closes when the air conditioner switch is ON.
FR1 is a fan relay that switches the drive output of the capacitor fan 8. The coil fan 8 is connected in series to the radiator fan 9 when the coil is energized, and the capacitor fan 8 is energized independently when the coil is de-energized.
FR2 is a fan relay that switches the drive output of the radiator fan 9, and only allows the radiator fan 9 to be energized only when the coil is de-energized.
[0019]
TwSW is a water temperature switch that opens when the engine water temperature is equal to or higher than a predetermined temperature.
PhSW1 is used when the engine is driven, and is a high-pressure switch for driving the engine that opens when the high-pressure pressure exceeds a predetermined pressure.
PhSW2 is used when the motor is driven, and is a high-pressure switch for driving the motor that opens when the pressure is higher than a predetermined pressure set to a pressure lower than the high-pressure switch PhSW1.
RSW is a relay switch that selects the high voltage switch PhSW1 for driving the engine when the engine is driven and the high pressure switch PhSW2 for driving the motor when the motor is driven.
[0020]
(Operation when the engine is driven)
When the engine state determination unit 13 determines engine operation, the drive selection unit 14 turns on the clutch 4, turns off the electric motor 3, and drives the compressor 1 with the engine 2.
During normal operation, when the engine water temperature and high pressure are in the normal range, as shown in FIG. 2, the water temperature switch TwSW and the engine driving high pressure switch PhSW1 remain closed, and the fan relay FR1 connects the condenser fan 8 and the radiator fan 9 to each other. In series connection, the fan relay FR2 is turned OFF, and the drive voltage of both the condenser fan 8 and the radiator fan 9 is set to Low (6V).
As shown in FIG. 3, when the high pressure switch PhSW1 for driving the engine is opened, the fan relays FR1 and FR2 are switched, and the condenser fan 8 and the radiator fan 9 are energized individually. Both fans 9 have a drive voltage of Hi (12 V).
[0021]
(Operation when motor is driven)
When the engine state determination unit 13 determines that the engine is stopped, the drive selection unit 14 turns off the clutch 4 and drives the electric motor 3 to switch the compressor 1 to motor drive.
When the motor is driven, the relay switch RSW is switched to select the motor driving high-voltage switch PhSW2, and the condenser fan 8 and the radiator fan 9 are easily switched to Hi (12V).
In other words, even if the high pressure is increased by a small amount, as shown in FIG. 4, the motor driving high pressure switch PhSW2 is opened, and the condenser fan 8 and the radiator fan 9 are energized individually, and the condenser fan 8 and the radiator fan 9 are In both cases, the drive voltage is Hi (12 V).
[0022]
(Effect of Example)
As shown in the above operation, when the engine drive is switched to the motor drive, the condenser fan 8 and the radiator fan 9 are easily switched to Hi (12V), and as a result, the average value of the fan output when the motor is driven increases. To do. That is, if the average value of the fan output when the engine is driven is the optimum operating point A when the engine is driven as shown in FIG. 5B, the average value of the fan output increases when the motor is driven, and the optimum operating point is reached. Approach B
Thus, the vehicle air conditioner of the present embodiment can bring the power consumption of the entire air conditioning system when the motor is driven closer to the minimum optimum operating point B, can reduce the power consumption when the motor is driven, and the battery BAT Power consumption can be reduced.
[0023]
[Modification]
If the cooling fan drive output can be continuously controlled, the cooling fan drive output when the engine is driven and when the motor is driven may be provided so as to be shifted by a predetermined value.
That is, in the above embodiment, when switching to motor driving, the cooling fan (capacitor fan 8 and radiator fan 9) is easily switched to Hi (12V), and the average cooling fan driving output during motor driving is increased. Although shown, the drive output of the cooling fan may be linearly adjusted so that the power consumption of the entire air conditioning system is minimized. In addition, you may estimate the power consumption of the whole air conditioning system from the drive output of each drive motor.
[0024]
In the above embodiment, an example in which the driving voltage of the cooling fan is increased when the motor is driven is shown, but the driving output of the cooling fan may be increased.
A motor clutch may be interposed between the electric motor 3 and the compressor 1, and the motor clutch may be controlled together with the electric motor 3.
Although an example in which the condenser fan 8 and the radiator fan 9 are separately provided has been shown, they may be shared.
[Brief description of the drawings]
FIG. 1 is a block diagram of a control device for a compressor.
FIG. 2 is an electric circuit diagram when the engine is driven normally.
FIG. 3 is an electric circuit diagram when the engine is driven and the high pressure is increased.
FIG. 4 is an electric circuit diagram when a high pressure is increased by a small amount by driving a motor.
FIG. 5 is a graph showing a relationship between a cooling fan voltage and power consumption.
[Explanation of symbols]
1 Compressor 2 Engine 3 Electric motor 8 Condenser fan (cooling fan)
9 Radiator fan (cooling fan)
15 Fan control unit (fan control means)

Claims (3)

(A) a compressor that can be driven by either a vehicle running engine or an electric motor that generates energization torque when energized;
(B) a cooling fan for cooling the radiator and the condenser;
(C) fan control means for changing and controlling the drive output of the cooling fan when the compressor is driven by the engine and when the compressor is driven by the electric motor ;
The fan control means increases the drive output of the cooling fan when the compressor is driven by the electric motor than when the compressor is driven by the engine. Air conditioner. The vehicle air conditioner according to claim 1,
The fan control means increases the driving voltage of the cooling fan when the compressor is driven by the electric motor than when the compressor is driven by the engine. Air conditioner. The vehicle air conditioner according to claim 1,
The fan control means sets a lower reference value for switching the cooling fan to a higher output when the compressor is driven by the electric motor than when the compressor is driven by the engine. A vehicle air conditioner characterized by the above.

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