JP3552910B2 - Compressor control device for hybrid electric vehicle - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a compressor control device for a hybrid electric vehicle.
[0002]
[Prior art]
In the following description, “engine on” refers to an engine operating state, and “engine off” refers to an engine stopped state.
[0003]
2. Description of the Related Art Conventionally, fixed capacity type compressors and variable capacity type compressors are known as automotive air conditioner compressors.
[0004]
The fixed displacement type compressor has a fixed refrigerant discharge amount, and in order to maintain the cabin temperature at the set temperature by the fixed displacement type compressor, the evaporator temperature is compared with a predetermined comparison reference value, If the evaporator temperature rises, the compressor is turned on for cooling (the electromagnetic clutch is turned on). Conversely, if the evaporator temperature falls, the compressor is turned off (the electromagnetic clutch is turned off) to temporarily turn off the cooling. Do.
[0005]
When this fixed capacity type compressor is installed in a hybrid electric vehicle, power consumption increases when the compressor is on, so control is performed to link the engine on / off with the compressor on / off. For this reason, the engine can be stopped if the indoor temperature is sufficiently cooled and the compressor is turned off during idling at low speeds or when the vehicle is stopped, thereby suppressing the fuel consumption required for the air conditioner. There are benefits that can be. On the other hand, when the engine speed increases and decreases frequently in conjunction with the on / off of the compressor even during middle to high speed running, fuel efficiency decreases, and the engine noise increases and decreases the noise to the occupants as the engine speed increases and decreases. This causes a problem that the quietness of the passenger compartment is impaired.
[0006]
On the other hand, the variable displacement type compressor can continuously and variably control the discharge amount of the refrigerant. In order to maintain the vehicle interior temperature at the set temperature by the variable displacement type compressor, the evaporator temperature must be controlled. When the evaporator temperature rises, it is compared with a comparison reference value (a reference temperature value set as an evaporator temperature corresponding to information such as the vehicle interior temperature and the vehicle heat load when the occupant sets the air conditioner temperature). The amount is increased in accordance with the temperature difference, and conversely, if the evaporator temperature becomes low, a continuously variable operation is performed in which the discharge amount of the compressor is reduced in accordance with the temperature difference from the comparison reference value.
[0007]
This variable displacement type compressor is widely used in engine vehicles, for example, one that increases or decreases the discharge amount by adjusting the opening degree of a refrigerant discharge valve of the compressor, or controls the pressure in the crank chamber to change the piston stroke. There is a swash plate type that increases or decreases the discharge amount, so that the compressor does not turn on and off intermittently to maintain the room temperature at the set temperature, which has the advantage of improving fuel efficiency and improving quietness . However, in the hybrid electric vehicle using the variable displacement type compressor, the engine is turned off when the hybrid electric vehicle uses the fixed displacement type compressor described above. This causes a problem that fuel efficiency deteriorates.
[0008]
[Problems to be solved by the invention]
As described above, according to the compressor control device of the conventional hybrid electric vehicle, in the case of using the fixed displacement compressor, there is a problem that the fuel consumption is reduced at the time of middle to high speed driving and the quietness of the engine sound is impaired. Also, when using a variable displacement compressor, the engine is not turned off to continuously operate the air conditioner even during low-speed traveling to stopping, which has the problem that the effect of energy saving, which is the purpose of a hybrid electric vehicle, is diminished. Was.
[0009]
The present invention has been made in view of such conventional problems, and has improved fuel efficiency at low speed running and at a stop without sacrificing fuel efficiency and quietness at medium to high speed running even while using a variable capacity compressor. It is an object to provide a compressor control device for a hybrid electric vehicle.
[0010]
[Means for Solving the Problems]
A compressor control device for a hybrid electric vehicle according to a first aspect of the present invention includes a compressor drive signal output unit that outputs a compressor drive signal when an air conditioner operation request is issued, a temperature detection unit that detects a temperature of an evaporator, and a refrigerant discharge amount. , A variable capacity type compressor arbitrarily increased or decreased between a maximum and a minimum, engine on / off means for turning on / off an engine according to vehicle information, and a compressor drive signal input from the compressor drive signal output means. And when the engine is not turned on by the engine on / off means, the first control means for turning on the engine and for intermittently operating the refrigerant discharge amount of the compressor in a fixed capacity; and If a compressor drive signal is input from the drive signal output means, When the engine is turned on by the engine on / off means, the refrigerant discharge amount of the compressor is increased or decreased so that the difference between the evaporator temperature detected by the temperature detecting means and a preset reference temperature becomes small. And second control means.
[0011]
According to a second aspect of the present invention, in the compressor control device for a hybrid electric vehicle according to the first aspect of the present invention, at least a vehicle speed is used as the vehicle information.
[0012]
In the compressor control apparatus for a hybrid electric vehicle according to the first and second aspects of the present invention, when the compressor drive signal is input from the compressor drive signal output means and the engine is not turned on by the engine on / off means, the first The control means turns on and off both the compressor and the engine so that the difference between the evaporator temperature detected by the temperature detection means and a preset reference temperature is small, and the refrigerant discharge amount of the compressor is intermittently switched in a fixed capacity. On the other hand, when the compressor drive signal is input from the compressor drive signal output means and the engine is turned on by the engine on / off means, the second control means controls the temperature of the evaporator detected by the temperature detection means. The difference from the preset reference temperature Increase or decrease the refrigerant discharge amount of the compressor so that fence.
[0013]
Thereby, when the compressor drive signal is input from the compressor drive signal output means and the engine is not turned on by the engine on / off means, for example, at low speed running when the engine is turned off and the automobile is driven by battery power, When the vehicle is stopped, the variable capacity compressor is operated intermittently with a fixed capacity, and the engine is turned on and off in conjunction with turning on and off the compressor. The aim is to improve the fuel efficiency required for air conditioners when driving at low speeds or when stopping, while improving fuel economy at the time and maintaining quietness of the engine sound.
[0014]
【The invention's effect】
As described above, according to the compressor control device for a hybrid electric vehicle according to the first and second aspects of the invention, the compressor drive signal is input from the compressor drive signal output means, and the engine is turned off to drive the vehicle with battery power. When running at low speeds or when stopping, the variable capacity compressor is operated intermittently with a fixed capacity, and the engine is turned on and off in conjunction with turning on and off the compressor. It is possible to improve fuel efficiency during low-speed running and stoppage while maintaining the improvement of fuel efficiency during middle to high speed running and the quietness of engine sound.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows the configuration of one embodiment of the present invention. The air conditioner controller 2 outputs a refrigerant discharge amount signal ECV to the variable capacity compressor 1 to control the discharge amount, and an air conditioner drive signal generating circuit (see FIG. (Not shown) to output the air conditioner ON command signal AUTO to the hybrid controller 7.
[0016]
The evaporator temperature sensor 3 (corresponding to a temperature detecting means) detects the evaporator outlet temperature Tint and outputs it to the air conditioner controller 2. The vehicle speed sensor 4 detects the vehicle speed and outputs it as a vehicle speed signal V to the hybrid controller 7. The battery capacity sensor 5 detects the remaining capacity of the battery and outputs it to the hybrid controller 7 as a remaining battery signal B. The engine coolant temperature sensor 6 detects the temperature of the engine coolant and outputs it to the hybrid controller 7 as an engine coolant temperature signal Tw.
[0017]
The hybrid controller 7 receives the air conditioner ON command signal AUTO from the air conditioner controller 2, the vehicle speed signal V from the vehicle speed sensor 4, the remaining battery level signal B from the battery capacity sensor 5, and the engine water temperature signal Tw from the engine water temperature sensor 6. It is determined whether the engine needs to be turned on / off based on the signals. Further, the hybrid controller 7 outputs an engine on / off command signal to an engine controller (not shown) based on the determination of the necessity of engine on / off, and outputs an engine on state signal a or an engine off signal to the air conditioner controller 2. The state signal b is output. When an air conditioner ON command signal AUTO is input from the air conditioner controller 2, an electromagnetic clutch signal MG is output to the variable capacity compressor 1 to turn on the variable capacity compressor 1.
[0018]
Next, the operation will be described. The variable displacement compressor 1 has a structure described in, for example, Japanese Patent Application Laid-Open No. 3-189379. When the electromagnetic clutch signal MG from the hybrid controller 7 turns on the engine only to turn on the air conditioner, for example. The engine is controlled at a constant speed, and the variable displacement compressor 1 is also rotated at a constant speed. As the control pressure of the variable capacity compressor 1 increases, the refrigerant discharge amount decreases. As the control pressure of the variable capacity compressor 1 decreases, the refrigerant discharge amount increases, and the discharged refrigerant is supplied to the evaporator. Therefore, if the control pressure is set to a minimum value equal to or lower than the refrigerant freezing temperature, the refrigerant discharge amount can always be maximized, and the refrigerant can be discharged at the maximum flow rate. Of course, an electronically controlled compressor may be used as the variable displacement compressor 1.
[0019]
The hybrid controller 7 determines whether the vehicle is driven by a battery power source or the engine is started and driven by the engine based on each input signal, and outputs an engine on / off signal to an engine controller (not shown). I do. That is, one of the following (i) to (iv) is determined.
[0020]
(I) The vehicle speed signal V detected by the vehicle speed sensor 4 is based on, for example, 30 km / h. When the vehicle speed signal V exceeds the predetermined speed, the engine is turned on, and when the speed is lower than the predetermined speed, the engine controller is instructed.
[0021]
(Ii) It is necessary to start the engine even when the remaining battery charge decreases and to supplementarily charge the battery. Based on the remaining battery capacity B detected by the battery capacity sensor 5, an engine-on command is issued to the engine controller. I do. Here, the remaining battery capacity is measured when the battery voltage value falls below a certain value, or when the battery discharge behavior is monitored and its integrated power exceeds a certain value, it is determined that the remaining battery capacity is low. Method is adopted.
[0022]
(Iii) Based on the engine water temperature signal Tw from the engine water temperature sensor 6, if a warm-up operation is required, an engine-on command is output to the engine controller.
[0023]
(Iv) When an air conditioner on command signal AUTO is received from the air conditioner controller 2, an engine on command signal is output to the engine controller.
[0024]
When the hybrid controller 7 outputs an engine-on command signal to the engine controller according to any of the above (i) to (iii), the hybrid controller 7 simultaneously outputs an engine-on state signal a to the air conditioner controller 2 to turn on the engine. When the state is notified and the engine-on command signal is not output to the engine controller, an engine-off state signal b is output to the air conditioner controller 2 to notify the engine-off state.
[0025]
Therefore, when the air conditioner controller 2 receives the engine on state signal a from the hybrid controller 7, the engine is continuously turned on, so that the discharge amount signal ECV is given to the variable displacement compressor 1 as a continuously variable signal. The refrigerant flow supplied to the evaporator is increased or decreased based on the evaporator temperature Tint, and the indoor temperature is automatically adjusted to the target temperature by variably controlling the refrigerant discharge amount.
[0026]
On the other hand, when the air conditioner controller 2 receives the engine off state signal b, the air conditioner controller 2 outputs a signal indicating the maximum discharge amount as the discharge amount signal ECV to the variable displacement compressor 1, and when the evaporator temperature Tint is equal to or higher than the freezing limit, The refrigerant is supplied to the evaporator at the maximum discharge flow rate, the intermittent operation is performed with a fixed capacity, and the air conditioner ON command signal AUTO is given to the hybrid controller 7. When the evaporator temperature Tint is lower than the freezing limit, the air conditioner ON command signal AUTO is not output. The hybrid controller 7 outputs an engine-on command signal to the engine controller and outputs an electromagnetic clutch signal MG to the variable displacement compressor 1 to turn on the compressor 1 only when receiving the air-conditioner-on command signal AUTO. Here, “perform intermittent operation with a fixed capacity” described in the claims means, for example, that the discharge amount of the refrigerant is maximized or minimized based on the evaporator temperature Tint (engine (Electromagnetic clutch off), but when the evaporator temperature Tint is equal to or higher than the freezing limit, it is not always necessary to maximize the refrigerant discharge amount. If the refrigerant discharge amount is controlled near the maximum, the effect of the present application can be obtained.
[0027]
Next, the operation of the hybrid controller 7 and the air conditioner controller 2 will be described based on the flowchart of FIG.
[0028]
First, in step S1, the hybrid controller 7 determines whether or not the compressor drive signal is output from the compressor drive signal generation circuit, based on whether or not the air conditioner ON command signal AUTO is input from the air conditioner controller 2; Returns to start. On the other hand, in the case of YES, the process moves to step S2. The air conditioner controller 2 constitutes a compressor drive signal output unit according to the first aspect.
[0029]
In step S2, it is determined whether or not the vehicle speed is equal to or higher than a predetermined speed (for example, 30 km / h) based on the vehicle speed signal V input from the vehicle speed sensor 4. If YES, the process proceeds to step S5 described later. On the other hand, in the case of NO, the process shifts to Step S3.
[0030]
In step S3, it is determined whether or not the remaining battery charge is equal to or less than a predetermined amount based on the remaining battery charge signal B input from the battery capacity sensor 5, and if YES, the process proceeds to step S5 described later. On the other hand, if the determination is NO, the process proceeds to step S4.
[0031]
In step S4, it is determined whether or not the engine water temperature is equal to or lower than a predetermined temperature based on the engine water temperature signal Tw input from the engine water temperature sensor 6. If YES, the process proceeds to step S5. On the other hand, if the determination is NO, the process proceeds to step S6 described below. The steps 2, 3, 4, the vehicle speed sensor 4, the battery capacity sensor 5, the engine water temperature sensor 6, the hybrid controller 7, and the engine controller 8 constitute an engine on / off means according to claim 1.
[0032]
In step S5, the hybrid controller 7 outputs an engine-on command to the engine controller, outputs an engine-on state signal a to the air conditioner controller 2, and outputs an electromagnetic clutch signal MG to the variable displacement compressor 1 to turn it on. The air conditioner controller 2 receives the engine ON state signal a, determines that the engine is operating, performs continuous variable displacement control of the variable displacement compressor 1, and returns to step S1. The step S5, the air-conditioning controller 2, and the hybrid controller 7 constitute a second control unit according to the first aspect.
[0033]
On the other hand, in step S6, the air conditioner controller 2 determines that the engine is off, performs the above-described fixed capacity operation control, and returns to step S1. The step S6, the air conditioner controller 2, and the hybrid controller 7 constitute the first control means according to the first aspect.
[0034]
Thus, according to the present embodiment, when the engine is operating for a reason other than the air conditioner request, the variable capacity compressor 1 is operated by the original continuous variable capacity control, while the engine is operated by the air conditioner request. By performing fixed-capacity intermittent operation control in which the variable capacity compressor 1 is controlled to be turned on and off together with the engine while fixing the control pressure at which the refrigerant can be discharged at the maximum flow rate, the operation is more medium than when a fixed capacity type compressor is used. -Improved fuel economy and quietness at high speeds can be achieved.Also, while using a variable capacity compressor, it is possible to intermittently operate the compressor with an engine with a fixed capacity at low speeds to stop at the same time as before while using a variable capacity compressor. it can.
[0035]
In the present embodiment, when the vehicle speed of the vehicle is equal to or lower than a predetermined speed, a fixed capacity intermittent operation in which the variable capacity compressor is turned on / off in conjunction with turning on / off the engine is performed, and the vehicle speed exceeds the predetermined speed. Sometimes, the same control is performed not only when the continuously variable control is performed but also when the engine water temperature is equal to or lower than a predetermined value (during a warm-up operation) or when the remaining battery charge is equal to or lower than a predetermined value (during a battery supplementary charge operation). Alternatively, the variable displacement compressor 1 may be configured to perform continuous variable control only when the engine is operated based on the vehicle speed and to perform intermittent operation with a fixed capacity only when the engine is stopped based on the vehicle speed.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of one embodiment of the present invention.
FIG. 2 is a flowchart showing operations of the hybrid controller 7 and the air conditioner controller 2 according to the embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Compressor 2 Air conditioner controller 3 Evaporator temperature sensor 4 Vehicle speed sensor 5 Battery capacity sensor 6 Engine water temperature sensor 7 Hybrid controller

Claims (2)

Compressor drive signal output means for outputting a compressor drive signal when an air conditioner operation request occurs,
Temperature detecting means for detecting the temperature of the evaporator,
A variable displacement compressor in which the refrigerant discharge amount is arbitrarily increased or decreased between a maximum and a minimum,
Engine on / off means for turning on / off the engine according to the vehicle information;
When a compressor drive signal is input from the compressor drive signal output means and the engine is not turned on by the engine on / off means, the engine is turned on and the refrigerant discharge amount of the compressor is fixedly changed. First control means for intermittent operation;
When a compressor drive signal is input from the compressor drive signal output means and the engine is turned on by the engine on / off means, the evaporator temperature detected by the temperature detection means and a preset reference temperature And a second control means for increasing or decreasing the refrigerant discharge amount of the compressor so as to reduce the difference with the compressor. The compressor control device for a hybrid electric vehicle according to claim 1, wherein the vehicle information includes at least a vehicle speed.

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