JPS624246B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is an air conditioner for an automobile that utilizes both a cooling cycle driven by an automobile engine and heating by heat generated by the automobile engine, by reducing the operating time of the cooling cycle. The present invention relates to a control device that can reduce the load on an automobile engine.

Conventionally, an evaporator that cools air introduced during the process of a cooling cycle driven by an automobile engine, a heater core that heats air downstream of the cooling member using cooling water of the automobile engine, and an evaporator are provided. An air conditioner for an automobile is known that includes an air mix damper that adjusts the amount of air that is exposed to the heater core out of the air that has passed through the heater core. The vehicle interior temperature is adjusted by changing the opening degree of the air mix damper.

The present invention provides an air conditioner of this type that is equipped with a temperature sensor that detects the temperature of the introduced air, and uses the measurement signal and a setting signal that indicates the desired temperature to control the heating member without driving the cooling cycle. It has a process that preferentially determines whether or not the desired temperature can be obtained by simply adjusting the amount of exposed air, and based on this determination, the cooling cycle is stopped by cutting off the driving force from the automobile engine to the cooling cycle. The purpose of the present invention is to provide a control device for a vehicle air conditioner that is easy to use by reducing the operating time of the vehicle, thereby reducing the burden on the vehicle engine, and automatically shutting off the driving force to the cooling cycle. It is something to do.

Next, one embodiment of the present invention will be described based on the accompanying drawings. In FIG. 1, reference numeral 1 denotes a cooling member for cooling introduced air, and in this embodiment, it is an evaporator in a known refrigerant compression-expansion type cooling cycle. A heating member 2 is located downstream of the evaporator 1 and heats the air passing through the evaporator. In this embodiment, it is a heater core that utilizes heat generated from an automobile engine. 3 is a damper serving as an air volume adjusting member. 4 is an electric fan that introduces air and blows it toward the vehicle interior 6. An evaporator 1, a heater core 2, a damper 3, and a fan 4 are arranged in series in a duct 5 as shown.

The cooling cycle including the evaporator 1 includes a refrigerant compressor 10 driven by an automobile internal combustion engine (hereinafter referred to as engine) 7, a condenser 11,
It is constructed by connecting a liquid receiver 12 and an expansion valve 13 through piping, forming a thermal cycle in which heat of the refrigerant is released in the condenser 11 and heat of the air introduced in the evaporator 1 is absorbed by the refrigerant.
Reference numeral 8 denotes an electromagnetic clutch, which has the function of transmitting and cutting off the driving force of the engine 7 to the compressor 10 in response to a command signal 9a.

The heater core 2 is connected to a cooling water pipe of the engine 7 and has a function of discharging the heat of the cooling water heated by the engine 7. Reference numeral 7a designates a known flow path control valve, which adjusts the flow path of the cooling water depending on the temperature of the cooling water into one path passing through the heater core 2 and one passing through a radiator (not shown) (7b).

The opening degree of the damper 3 can be electrically controlled, for example, by a servo motor 30. 31 is a potentiometer that electrically detects the opening degree of the damper 3.

A control circuit 9 controls the opening degree of the damper 3 and the connected state and disconnected state of the electromagnetic clutch 8 in accordance with various input conditions. The elements that determine the input conditions of the control circuit 9 include an inside air sensor 90 that measures the temperature inside the vehicle interior 6, an outside air sensor 91 that measures the outside air temperature, and an intake air sensor that measures the temperature of the air introduced into the duct 5. There are a sensor 92, a setting device 93 for setting a desired temperature, and a potentiometer 31 for detecting the opening degree of the damper 3. Signals 90a, 91a, 92 input to the control circuit 9 from these sensors, etc.
a, 93a, and 31a are all set to resistance values or voltage values corresponding to the resistance values so as to be analog signals. Therefore, the sensors 90, 91, and 92 are composed of temperature-sensitive resistance elements such as thermistors, the setting device 93 is composed of a variable resistor, and the potentiometer 31 is composed of a sliding resistor. The signals outputted from the control circuit 9 are a value signal 9a indicating connection or disconnection of the electromagnetic clutch 8, and a signal 9b indicating the control position of the servo motor 30 which controls the opening degree of the damper 3. Next, an electric control system including the control circuit 9 and its input/output section will be explained.

In FIG. 2, sensors 90, 91, 92, setter 93, potentiometer 31, servo motor 30, and electromagnetic clutch 8 are the same as described with respect to FIG. Reference numerals 901 and 902 are circuits that generate control signals indicating the opening degree of the damper 3, that is, the amount of air to be adjusted, in response to input signals from the sensors 90, 91, 92 and the temperature setting device 93. A first control signal generation circuit 901 generates a first control signal 9 according to a deviation between a measurement signal 92a indicating the temperature of the introduced air from the intake air sensor 92 and a setting signal indicating the desired temperature from the temperature setting device 93.
01a is generated as an analog voltage value. Specifically, the first control signal generation circuit 901 is configured mainly of a known operational amplifier having two inputs: a measurement signal 92a as an analog voltage value and a setting signal 93a as an analog voltage value. The gain of this operational amplifier is determined by the first control signal 901.
The damper 3 when the evaporator 1 is not operating (that is, the cooling cycle is stopped) by a.
The circuit is adjusted to indicate the degree of opening (amount of air to be adjusted). Among the measurement signals input to the first control signal generation circuit 901, measurement signals 90a and 91a shown by broken lines are used for the purpose of correcting the output signal of the operational amplifier. For example, the output signal of the first operational amplifier described above is used as one input, and the other measurement signal 90 is used as the input.
A, 91a is connected to the second operational amplifier, and its output receives the other measurement signals 90a, 91a in response to the output signal of the first main operational amplifier.
A final first control signal 901a that is slightly corrected according to the magnitude of signal 91a is generated. It is possible to optionally provide additional operational amplifiers after the second one for correction.

The second control signal generation circuit 902 includes the internal air sensor 9
A measurement signal 90a indicating the vehicle interior temperature from 0 and a setting signal 93a indicating the desired temperature from the temperature setting device 93.
A second control signal 902a corresponding to the deviation from the second control signal 902a is generated as an analog voltage value. Specifically, the main element is a known operational amplifier having two inputs: a measurement signal 90a as an analog voltage value and a setting signal 93a as an analog voltage value. The gain of this operational amplifier is set so that the control signal 902a indicates the opening degree of the damper 3 (the amount of air to be regulated) when the evaporator 1 is operating (that is, the cooling cycle is operating). It has been adjusted. In addition, a measurement signal 91a from the outside air sensor 91
is input for the correction.

FIG. 3 shows the first control signal 901a and the second control signal 901a.
It shows the characteristics of the control signal 902a, and shows the relationship between the desired temperature on the horizontal axis and the damper opening degree at that time.
For convenience of explanation, the temperature of the air introduced and the temperature of the engine cooling water introduced into the heater core 2 are assumed to be constant. In the figure, when the damper opening is small, that is, when the amount of air exposed to the heater core 2 is small, the vehicle interior temperature is low, and when the damper opening is large, the vehicle interior temperature is high. It can also be seen that the vehicle interior temperature can be controlled to the desired temperature even if the cooling cycle is stopped when the desired temperature is higher than TA and the damper opening degree is controlled according to the first control signal 901a. Although not shown, the controllable area (active area) according to the first control signal 901a, that is, the value of the temperature TA also changes depending on the temperature of the introduced air.

The first and second control signals 901a, 902
a is input to the switching circuit 903, and only one of them is selected. The switching circuit 903 is composed of a known analog switch, and obtains its switching signal from a comparison circuit 904. A comparison circuit 904 generates a switching signal 904a when the first control signal 901a is larger than a preset value. This comparison circuit 904 is composed of a known voltage comparator, and is switched when the first control signal 901a, which is one input thereof, is larger than another input value, which is set to a value corresponding to, for example, 5 (%) of the damper opening degree. A signal 904a is generated. The comparison circuit 903 receives a switching signal 904.
The first control signal 901a is selected when a occurs, and the second control signal 902a is selected when the switching signal 904a disappears.
Select.

905 is a differential amplifier circuit, which receives the control signal 903a (901a or 902a) selected by the switching circuit 903 as one input, and receives the position voltage 31a from the potentiometer 31 indicating the opening degree of the damper 3 as the other input. As an input, an output signal 9b is generated which is equal to the deviation between both inputs. The servo motor 30 is controlled to a position value according to the output signal 9b. At this time, the potentiometer 3
1 has a function of constantly detecting the opening degree of the damper 3 and feeding it back to the differential amplifier circuit 905.

Reference numeral 906 denotes an amplifier circuit that amplifies the switching signal 904 of the comparison circuit 904 and generates a cutoff signal 9a that puts the electromagnetic clutch 8 in the cutoff state. This cutoff signal 9a opens a normally closed relay contact inserted into an energizing circuit (not shown) of the electromagnetic clutch 8. Note that the power source and power line are omitted in FIG. 2.

To summarize the functions of each part of the electrical control system mentioned above,
First and second control signal generation circuits 901, 902
is always in operation, and both circuits 901 and 90
2, the first control signal 90 is determined by the temperature of the introduced air and the desired temperature.
1a is always overestimated in the comparison circuit 904, and when the first control signal 901a is in the active region, the electromagnetic clutch 8 is cut off to stop the cooling cycle, and at the same time, the differential amplifier circuit 905 receives the first control signal 901a. By inputting the signal 901a, the servo motor 30
The damper 3 is controlled to an opening degree in accordance with the characteristic 901a shown in FIG. On the other hand, when the first control signal 901a is not in the active region, the damper 3 is controlled to the opening degree in accordance with the characteristic 902a in FIG. 3 while the cooling cycle is operating. Therefore, the actual damper opening characteristic is shown by the arrow A in Figure 3.
The characteristic is that the first and second controls are switched at the point.

In this embodiment, if a switch is provided which is turned on according to the user's selection, and when the switch is turned on, the operation of the comparison circuit 904 is stopped and the switching signal 904a disappears.
It is also possible to select a temperature control mode using only the second control signal 902a shown in a. This is effective when the evaporator 1 is used as a dehumidifying member.

In the above embodiments, the control circuit 9 was constructed using hardware, but it can also be constructed as a circuit controlled by a digital computer called a so-called microcomputer. FIG. 4 shows an embodiment in which an electrical control system is configured using a digital computer, and sensors 90, 9
1, 92, temperature setting device 93, potentiometer 3
1, servo motor 30, and electromagnetic clutch 8 are the same as described with respect to FIG. 1, and amplifier circuit 906 is the same as described with respect to FIG. 910 is a central processing unit (hereinafter referred to as CPU) that performs arithmetic processing according to a predetermined program;
911 is an oscillator that generates a reference clock signal for performing the arithmetic processing step by step; 912 is a common bus that inputs and outputs data signals and command signals; and 913 is a memory that stores the program and can also temporarily store other data. 914 is an analog multiplexer that selects an analog signal as a voltage value from the sensors 90, 91, 92, 93, 31 based on a command (not shown) from the CPU 910, and converts the selected analog signal into a binary code. An input device consisting of an A-D converter for converting, 915
is a latch that temporarily stores the binary code calculation data given by the common bus 9, and D that converts the temporarily stored dame into an analog signal as a voltage value.
-A converter 916 is a flip-flop that is set and reset by specific 2-bit data in common bus 912. Note that command signals for each device connected to the common bus 912 in the figure are omitted for convenience, and the role of each device will be explained in the following explanation of the process of arithmetic processing by the CPU 910.

Figure 5 shows the data stored in the memory 913 and the CPU
9 is a flowchart showing the contents of a program that is sequentially read and executed when the operation of 910 starts. Then, according to this program, the CPU 910 inputs the input device 91 at the first stage 910a.
Analog signals 90a, 91a, 92a, 93a, 31a from sensors 90, 91, 92, temperature setting device 93 and potentiometer 31
are sequentially selected and A-D converted, and the binary code signals are stored in memory 913. Next stage 91
At 0b, the introduced air temperature (measurement signal of the intake sensor 92) is encoded in binary form from the memory 913.
Read out the respective stored values of the desired temperature (setting signal of the temperature setting device 93) which are also encoded in binary.
Calculate the deviation of Further, calculation data corrected based on the vehicle interior temperature (measurement signal of the inside air sensor 90) and the outside air temperature (measurement signal of the outside air sensor 91) is calculated as the first control signal. This arithmetic expression is programmed in advance so as to obtain the same result as the gain adjustment of the operational amplifier in the first control signal generation circuit shown in FIG. The calculation data calculated as the first control signal is temporarily stored in the memory 913. next stage 910c
Then, the calculation data as the first control signal is read from the memory 913, and it is determined whether the value is larger than a set value corresponding to, for example, 5% of the opening degree of the damper 3. Judgment result: greater than the set value (YES)
In this case, a command is given to set the flip-flop 916 at stage 910d. The set signal 916a from the flip-flop 916 is amplified by the amplifier circuit 906, thereby placing the electromagnetic clutch 8 in a disconnected state. Next, in the stage 910e, the calculation data as the first control signal and the opening degree of the damper (detection signal of the potentiometer 31) are read out from the memory 913, and the deviation between the two is calculated. This deviation signal commands the output device 915 to latch in the next stage 910f. The latched deviation signal is DA-converted and output as a control signal 9b for the servo motor 30. Next to stage 910f is stage 91 again.
Return to 0a, repeat the same process, and control the damper opening degree so that the desired temperature is obtained.

At stage 910c, if the first control signal is not greater than the set value (NO) as a result of the determination, the process proceeds to stage 910g instead of stage 910d. Flip-flop 9 at stage 910g
16 reset is commanded. Set signal 9
16a disappears, the electromagnetic clutch 8 becomes connected, and the cooling cycle is operated. Next stage 91
At 0h, the stored values of the vehicle interior temperature and desired temperature are read out from the memory 913 and the deviation thereof is calculated. The calculated data further corrected by the outside temperature is calculated as a second control signal, the calculated data of the first control signal is erased, and the calculated data of the second control signal is temporarily stored in its place. And stage 9
In step 10e, the second control signal and the damper opening degree are read from the memory 913 and the deviation thereof is calculated.

The above process is repeated at high speed to adjust the opening degree of the damper 3. When sharing the digital computer with another control system, store the entire program including the program shown in Figure 5 in the memory 913, and connect the input/output devices for the other control system to the common bus. By doing so, the control device for the vehicle air conditioner according to the present invention and other controls in the vehicle can be performed in a time-sharing manner.

As described above, according to the present invention, by comparing the target temperature of the cabin air set by the target temperature setting device and the temperature of the air introduced into the cooling member of the cooling cycle device, Accurately determines whether the desired temperature can be obtained without operating the cooling cycle equipment, and automatically controls temperature control when the cooling cycle equipment is operating and temperature control when the cooling cycle equipment is not operating. This has the excellent effect of reducing the operating time of the cooling cycle device and lightening the burden on the automobile engine.

Moreover, in the present invention, a reference value is set for controlling the adjustment amount of the air volume adjusting member that changes the temperature of the air blown into the vehicle interior by simply operating the target temperature setting device, and for controlling the on/off of the cooling cycle device.
It has the advantage of being changeable and very easy to operate.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram showing an embodiment of an air conditioner for an automobile to which a control device according to the present invention is applied;
2 is an electrical wiring diagram showing an example of an electrical control system including the control circuit 9 shown in FIG. 1, and FIG. 3 is a control characteristic diagram 4 for explaining the operation of the electrical control system shown in FIG. 2.
This figure is an electrical wiring diagram showing another example of the electrical control system including the control circuit 9 shown in FIG. 1, and FIG. 5 is a flowchart for explaining the operation of the electrical control system shown in FIG. 4. 1... Evaporator serving as a cooling member, 2... Heater core serving as a heating member, 3... Damper serving as an air volume adjustment member, 4... Electric fan, 5... Duct,
6... Vehicle interior, 7... Automobile engine (engine), 8
. . . Electromagnetic clutch, 9 . . . Control circuit, 30 . . . Servo motor, 90 . 2 control signal generation circuit, 903...switching circuit, 904...comparison circuit,
910...Central processing unit (CPU), 913...Memory, 914...Input device, 915...Output device, 916...Flip-flop.

Claims (1)

[Claims] 1. A target temperature setting device that outputs a target temperature signal according to the target temperature of the air inside the vehicle, which is set by the occupant, and which receives the driving force of the automobile engine via a transmission device and controls the cycle. A cooling cycle device that cools the refrigerant midway through the cycle, and a ventilation path that is installed in the middle of the cycle of this cooling cycle device and that communicates with the interior of the vehicle,
a cooling member that cools the air introduced into the ventilation passage with the cooled refrigerant; a heating member that heats the air downstream of the cooling member with heat generated from the automobile engine; and the ventilation passage. an air volume adjustment member that is disposed in a road and changes the temperature of air blown into the vehicle interior by adjusting the amount of air that is exposed to the heating member out of the air that has passed through the cooling member; and the target temperature setting device. A control device for an automotive air conditioner comprising: a temperature control device that controls the amount of adjustment of the air volume adjusting member to bring the air temperature in the vehicle interior to the target temperature based on a target temperature signal from the cooling member; A temperature detection means that detects the temperature of the introduced air and generates a detected temperature signal, and compares the detected temperature signal from the temperature detection means with the target temperature signal from the target temperature setting device, and introduces the air into the cooling member. When it is determined that the air temperature at which the air flow is controlled is a temperature at which the air volume adjustment member can be controlled to obtain the target temperature, the transmission device outputs an output that cuts off transmission of the driving force of the automobile engine from the cooling cycle device. 1. A control device for an air conditioner for an automobile, comprising: cooling capacity determining means for generating a signal.