JPS6330162B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power-saving air-conditioning control device that performs temperature control by reducing the drive rate of a compressor in vehicle air-conditioning control.

Conventionally, in automobile air conditioning control systems, a compressor is connected to the on-board engine, and the compressor compresses refrigerant to achieve cooling.There is a desire for automobiles to save power by reducing the operating rate of this compressor. ing.

Japanese Patent Publication No. 51-120536 proposes using an analog circuit to determine the surplus cooling capacity and to connect or disconnect the compressor according to the determination result.

However, in the known devices, it is difficult to handle control input signals due to the analog circuit configuration, and there is a problem in that the structure becomes complicated when increasing the control function of the air conditioner.

Furthermore, in the known method, there is a problem of delay because the determination of the cooling surplus capacity depends on the actual position of the temperature control member as a control result.

The present invention, in meeting the demand for power saving,
By using control calculations using digital computer software, the initial objective was achieved with a simple configuration, and the aim was to further reduce unnecessary cooling capacity in response to the actual temperature control state inside the vehicle. shall be.

According to the present invention, the above object is achieved by adopting the configuration shown in the functional block diagram of FIG. Note that in FIG. 3, the numerals or symbols particularly shown in parentheses are the same as those described in the description of the embodiment and the drawings to be described later.

That is, the control device of the present invention is arranged in a ventilation duct 1 for sending air toward the vehicle interior, a blower motor 3 for generating an air flow toward the vehicle interior VC in the ventilation duct 1, and the ventilation duct 1.
An air conditioner comprising a heater 6 and a cooler 4 having a cooling mechanism 5 driven by an on-vehicle power source, and a heat exchange means TR capable of exchanging heat with the air flow and adjusting the amount of heat exchange. It has a functional part.

The control device of the present invention performs temperature control to maintain the vehicle interior temperature at the target set temperature and control of the operating rate of the cooler.
This is realized by adopting a digital control method and having a simple configuration. For this reason, a control signal generating means PI is provided that generates various temperature control conditions necessary to maintain the vehicle interior temperature at the target set temperature.
Various temperature control conditions that cause PI are input storage means.
It is periodically input to the MM as a digital value and stored, and the latest control conditions are always prepared there.
For this reason, the control signal generating means PI includes a single converting means 16 that sequentially converts a plurality of temperature control conditions into digital values, and a storage means RAM that stores each of the converted digital values.

The digital values prepared in the storage means RAM are used each time the following first and second determination means JD1, JD2 and control amount calculation means CP require them.

The first determination means JD1 periodically determines the presence or absence of surplus cooling capacity in the heat exchange means TR based on at least one of the digital values of various temperature control conditions prepared in the storage means RAM of the input storage means MM. Then, a first control output signal CS1 corresponding to the determination result is generated.

The second determination means JD2 periodically determines whether or not air cooling by the heat exchange means TR is necessary based on at least the vehicle interior temperature of the digital values of various temperature control conditions prepared in the storage means RAM of the input storage means MM. If cooling is necessary according to the determination result, the determination by the first determining means JD1 is made valid, and if cooling is not necessary, the first control output signal CS1 is set to the first determining means JD1. 1. Judgment means
Set to the same state as if it was determined by JD1 that there was surplus capacity.

The control amount calculation means CP calculates the correction amount corresponding to the judgment results by the first and second judgment means JD1 and JD2 and the storage means RAM of the input storage means MM.
The adjustment control amount of the heat exchange amount in the heat exchange means TR is periodically calculated based on the digital values of various temperature control conditions prepared in the table, and a second control output signal CS2 corresponding to the result is generated.

Therefore, the determination conditions adopted by the determination means JD1 and JD2 share at least a part of the digital value of the temperature control condition used by the control amount calculation means CP to calculate the adjustment control amount. This contributes to the following advantages in connection with the adoption of a configuration in which temperature control conditions are stored as digital values in the storage means RAM.

First, the control signal generating means PI that generates the temperature control conditions can be used as is;
There is no need to provide an additional control signal generator just to obtain the judgment conditions.

Second, the configuration of the input storage means MM (for example, A-
The D converter 16) can be shared.

Third, storage means for storing digital values (for example, a storage means built in the microcomputer 17)
RAM) can be shared.

These points are possible because when each judgment means JD1, JD2 and calculation means CP obtain the respective necessary digital values, there is no problem of interference when these digital values are used by different means, so the function of each means is eliminated. It is even more advantageous in that it can be realized accurately.

By the way, since the second determining means JD2 determines from the vehicle interior temperature that air cooling by the heat exchange means TR is not necessary, that is, heating is necessary, there is no need to wait for the determination result by the first determining means JD1. The cooler can be stopped without any problems.
Even when the cooler is stopped, the calculation means CP calculates the correction amount, so that temperature control is always accurately performed in conjunction with the reduction in the operating rate of the cooler.

Note that the first and second determining means JD1, JD
A first driving means 20 is provided to turn on and off the cooling mechanism 5 in response to the first control output signal CS1 obtained by the control amount calculation means CP. A second drive means 19 is provided which adjusts the heat exchange amount of the heat exchange means TR in response to the control output signal CS2.

The present invention will be described below with reference to embodiments shown in the drawings. FIG. 1 is an overall configuration diagram showing this embodiment.

In this Figure 1, 1 is an air duct that guides air for cooling and heating of the air conditioner of the car, and an outside air intake 1
Outside air is introduced through the air intake port 1b, and air inside the vehicle is circulated through the inside air intake port 1b. 2 is an internal/external air switching damper,
Manually switching between outside air introduction and inside air circulation.The outside air introduction state is shown by a solid line, and the inside air circulation state is shown by a broken line. 3 is a blower motor that sucks in air from the outside air intake port 1a or the inside air intake port 1b and blows the air. Reference numeral 4 denotes an evaporator through which air blown by the blower motor 3 is cooled and passed, and is disposed across the duct 1. 5 is a compressor that compresses and circulates refrigerant. It is connected to the engine, which is the on-board drive source of an automobile, with a belt, and is operated by its rotational driving force. The compressed refrigerant is sent to the condenser, and passed through the expansion valve to the evaporator. Send to 4. The compressor 5 has a built-in electromagnetic clutch for connecting and disconnecting the compressor to the engine, and when the electromagnetic clutch is energized, it becomes connected, and when the energization is cut off, it becomes disconnected. Reference numeral 6 denotes a heater core disposed within the air duct 1, which introduces engine cooling water and uses its heat to heat the blown air. Reference numeral 7 denotes an air mix damper, which adjusts the ratio of the amount of air introduced into the heater core 6 side and heated to the dehumidified and cooled air that has passed through the evaporator 4, thereby adjusting the temperature.
The opening degree of the air mix damper 7 is determined based on various information such as inside air temperature, outside air temperature, set temperature, and feedback of the opening degree of the air mix damper 7.
The vehicle interior temperature is automatically controlled to maintain it at the control target temperature.

9 is a room temperature sensor that detects the temperature inside the vehicle interior 8 and generates a room temperature signal; 10 is an opening sensor that detects the opening degree of the air mix damper 7 and generates an opening signal, using a potentiometer. There is. Reference numeral 11 is an outside temperature sensor that detects the temperature of outside air and generates an outside temperature signal, and 12 is a temperature setting device that determines the set temperature of the control target, and the occupant manually sets the desired room temperature. 13
14 is an engine rotation sensor that generates a rotation pulse with a frequency corresponding to the engine rotation; 15 is a mode setting device that controls heater mode, defroster mode, and cooler mode in an automatic air conditioner; Various modes such as mode are manually determined and respective digital mode signals are generated.

Reference numeral 16 denotes an A/D converter that converts analog signals into digital signals, which sequentially converts the room temperature signal, opening degree signal, outside temperature signal, and setting signal into digital signals. 17 is a single-chip microcomputer that executes digital calculation processing of software according to a predetermined air conditioning control program, and is connected to a several-megahertz crystal oscillator 18, and is stabilized based on the power supply from the on-board battery. It is activated by being supplied with power from a stabilized power supply circuit (not shown) that generates voltage. Then, through calculation processing by the microcomputer 17, the operating (on) conditions and operating stop (off) conditions of the compressor 5 are determined, and a command signal for turning on and off the compressor 5 and the air mix damper 7 are determined.
Generates a command signal to adjust the opening.

The microcomputer 17 is a read-only memory (ROM) that stores an air conditioning control program that defines the calculation procedure for generating the above command signal.
, a central processing unit (CPU) that sequentially reads the air conditioning control program from this ROM and executes the corresponding arithmetic processing, and a central processing unit (CPU) that temporarily stores various data related to the arithmetic processing of this CPU and reads the data by the CPU. Memory (RAM) that can
, a clock generator that uses a crystal oscillator 18 to generate reference clock pulses for the various calculations mentioned above, and an input/output (I/O) that adjusts the input and output of various signals.
O) It is composed of a one-chip large-scale integrated circuit (LSI) whose main part is a circuit section.

Reference numeral 19 denotes an opening adjustment actuator that adjusts the opening of the air mix damper 7, which receives an opening command signal output from the microcomputer 17 based on temperature control calculation processing and responds to the opening command signal. perform the operation to be performed. Reference numeral 20 denotes a compressor drive circuit for on/off control of the compressor 5, which controls energization and de-energization of the electromagnetic clutch of the compressor 5 in response to command signals from the microcomputer 17.

An opening sensor 10 that detects the opening of the air mix damper 7 is used as a detection means for determining the degree of utilization of the cooling capacity in the air conditioning control device. When the opening degree is located near the maximum cooling capacity, it indicates that there is no cooling surplus capacity, and on the other hand, when the opening degree is adjusted to any other degree, it indicates that there is cooling surplus capacity.
When the microcomputer 17 determines that there is this surplus cooling capacity, it provides the drive circuit 20 with an off command signal for turning off the compressor 5.

Next, the operation of the above configuration will be explained with reference to the calculation flowchart in FIG.

Now, when a car equipped with this device starts driving, the microcomputer 17 receives a stabilized voltage from the stabilized power supply circuit, becomes operational, and processes the air conditioning control program shown in the figure at a cycle of several hundred milliseconds. Execute.

That is, the arithmetic processing of the air conditioning control program is started from the start step 101 in FIG. 2, and the process proceeds to the signal input step 102. This signal input step 102
Here, the room temperature signal, opening degree signal, outside temperature signal, and setting signal converted into digital values by the A/D converter 16, the starting signal indicating starter operation from the starting switch 13, and various signals from the mode setting device 15 are shown. The mode signal and the rotation speed data calculated by the rotation speed calculation routine (not shown) using the rotation pulse from the engine rotation sensor are input and stored, and the process proceeds to step 103.

In the starter operation determination step 103, it is determined whether the starter is in operation based on the starting signal input and stored in the signal input step 102. At this time,
If the starter is operating, the judgment will be YES and the compressor off step 104 will be executed.
Then, an off command signal for turning off the operation of the compressor 5 is applied to the compressor drive circuit 20 that generated it. On the other hand, if it is determined in step 103 that the starter is not operating and the result is NO, the process advances to step 105 to determine low engine speed, and the engine indicates normal idling based on the rotational speed data input and stored in step 102. Determine whether the speed has become low. At this time, if the engine rotation speed becomes low, the determination becomes YES, and the process proceeds to step 106, where a compressor off command signal is applied to the drive circuit 20. Furthermore, the process proceeds to a low speed level correction step 107 to provide hysteresis in low speed determination. On the other hand, if it is determined in step 105 that the engine speed is not low and the result is NO, the process proceeds to low speed level setting step 108 and low speed level correction step 107.
The low speed level of the value excluding the correction amount is set for low speed judgment in the next calculation, and the process proceeds to step 109.

In temperature determination step 109, it is determined based on the room temperature signal input and stored in step 102 and the setting signal whether the room temperature has become sufficiently lower than the set temperature by exceeding the dead zone width. At this time, when the room temperature is sufficiently lower than the set temperature, the determination becomes YES, and the process proceeds to compressor off step 110, where an off command signal is applied to the compressor drive circuit 20, and the process proceeds to temperature level correction step 111, where temperature judgment is performed. The temperature level is corrected to provide hysteresis. On the other hand, in temperature determination step 109, it is determined that the room temperature has exceeded the set value, and the result is
If NO, the process proceeds to level correction cancellation step 112, where the correction amount in step 111 is canceled for temperature determination in the next calculation, and the process proceeds to step 113.

In the surplus capacity determination step 113, based on the opening signal from the opening sensor 10 input and stored in the signal input step 102, it is determined whether the opening of the air mix damper 7 is located further away from the vicinity of the maximum cooling. Determine. At this time, if the opening degree of the air mix damper 7 is far from the vicinity of the maximum cooling, the result becomes YES, and the process proceeds to compressor off step 114, as well as to the capacity level correction step.
At step 115, the ability level is corrected to provide hysteresis, and the process proceeds to step 116 for calculating the amount of correction. Also,
After each of steps 104, 107, and 111 described above is processed, step 116 is similarly processed. In this correction amount calculation step 116, a correction amount for air conditioning control, particularly temperature control, due to the stoppage of operation of the compressor 5 is determined, and correction is applied to the air conditioning control calculation.

On the other hand, in surplus capacity determination step 113, it is determined that there is no surplus cooling capacity, and the determination is NO.
When this happens, the process proceeds to a capability level setting step 117, where the capability level of the value excluding the correction amount in the correction step 116 is set for surplus capability determination in the next calculation.

In the compressor off step 118, the control is applied to the compressor drive circuit 20 which generated the on command signal indicating the operation command for the compressor 5, and the process proceeds to the next controlled variable calculation step 119. Note that even after processing step 116 above, the process proceeds to step 119. In the control amount calculation step 119, the target opening degree of the air mix damper 7 to maintain the room temperature at the set temperature is calculated based on various conditions such as the room temperature, outside temperature, set temperature, and damper opening degree input and stored in step 102. In addition, if the damper opening is passed through the correction amount calculation step 116, the target opening after the correction is calculated based on the correction, and the process proceeds to the damper opening command step 120, where the command signal for the target opening is used to adjust the opening. In addition to the actuator 19, it controls the opening degree of the air mix damper 7 and controls the end step.
Proceed to step 121 to end one calculation process.

Thereafter, similar calculations are repeated at intervals of several hundred milliseconds to perform air conditioning control including room temperature control and compressor control.

Next, the overall operation in various states during cooling will be explained. First, before starting the engine, the signal input step 102 is processed from the start step 101, and the process proceeds to the starter operation determination step 103, but at this time, since the starter is not activated, steps 105→106 are performed.
Steps 107→116→119→120→121 are then executed to control the compressor 5 to a stopped state. This repetition continues until the engine starts, during which time the compressor 5 is maintained in a stopped state.

Then, when the engine is started, the steps
The judgment in step 103 is reversed from NO to YES, and step 104
→116 →119 →120 are performed, and the compressor 5 is maintained in a stopped state by repeating this process until the engine starting is completed and the start signal from the start switch 13 disappears.

Eventually, when the engine finishes starting and becomes idling, the determination in step 103 is reversed from YES to NO, and engine low speed determination step 105 is processed. At this time, the engine speed is not high enough, so steps 106→107→116→119→
120 is repeated to maintain the compressor 5 in a stopped state.

After that, when the car starts running and the engine speed becomes sufficiently high, the determination result in step 105 is reversed from YES to NO, and the low speed level is set to a small value in step 108. Then, the process proceeds to temperature determination step 109, where it is determined whether the room temperature is sufficiently lower than the set temperature, but if the room temperature is not being cooled, the determination is NO, so the process proceeds to step 112. In step 112, the correction of the temperature set is canceled, but since the temperature level has not been corrected in the previous calculation process, the same level is maintained, and the process proceeds to step 113 for determining surplus capacity.

In the surplus capacity determination step 113, the opening sensor 10
The presence or absence of excess cooling capacity is determined based on the opening degree signal of the
Then, in step 117, the capacity level is set to the same value as the value determined in the initial setting, and the process proceeds to the next compressor on step 118, where the drive circuit 20 holds the on command signal and the cooling of the passenger compartment 8 is started. Start. In the next control amount calculation step 119,
The target opening degree of the air mix damper 7 to maintain the room temperature at the set value is determined based on various conditions such as room temperature, outside temperature, set temperature, damper opening degree, etc., and a command signal corresponding to the result is sent to the actuator in step 120. 19
Add to. As a result, the air mix damper 7
The opening degree of the air conditioner is controlled, and temperature adjustment of the air conditioner inside the vehicle compartment 8 is started.

Steps 101 to 102 → 103 → 105 → until the temperature inside the passenger compartment 8 approaches the set value set on the temperature setting device 12
108→109→112→113→117→118→119→120→121
The arithmetic processing up to the above is repeated, and the opening degree of the air mix damper 7 is adjusted while the compressor 5 continues to operate, thereby gradually lowering the temperature in the vehicle interior 8 through air conditioning control. At this time, when the temperature inside the vehicle compartment 8 is sufficiently high relative to the set temperature, the opening degree of the air mix damper 7 is controlled to the maximum cooling position that almost blocks the flow of air to the heater core 6, that is, at a large angle. As the temperature in the passenger compartment 8 decreases, the opening degree of the air mix damper 7 gradually moves away from the maximum cooling position, and the angle gradually decreases, reducing the temperature in the passenger compartment 8 to the set value. Keep it.

During this air conditioning control, if the opening degree of the air mix damper 7 becomes smaller than the capacity level angle determined in the capacity level setting step 117, the surplus capacity determination step 113 in the above-mentioned repeated calculation is performed.
When the determination result is reversed from NO to YES, an OFF command signal is applied to the drive circuit 20 at a compressor off step 114 to stop the compressor 5. In addition, the ability level correction step
Perform correction to provide hysteresis with 115,
In step 119, the target opening degree of the air mix damper 7 is calculated including the correction amount calculated in the correction amount calculation step 116, and a command signal for the target opening degree is applied to the actuator 19.

In this way, since the temperature in the vehicle compartment 8 is controlled to be maintained at the set temperature while the compressor 5 is stopped, the opening degree of the air mix damper 7 gradually increases. When the opening reaches the correction level determined in the capacity level correction step 115, the judgment result in the surplus capacity judgment step 113 is reversed from YES to NO. For this reason, the ability level set step
In step 117, the capacity level is reset, and in step 118, a compressor ON command signal is applied to the drive circuit 20, and the opening degree of the air mix damper 7 is adjusted again while the compressor 5 is in operation. Keep the temperature at the set temperature.

In this way, by determining whether or not there is surplus cooling capacity based on the opening degree of the air mix damper 7 during normal driving and controlling the operation and stop of the compressor 5, the compressor 5 is activated by the vehicle engine. The engine load can be reduced when the engine is stopped.

Furthermore, during the above operation, if the temperature inside the vehicle compartment 8 falls sufficiently below the set temperature, the judgment result of the temperature judgment step 109 in the above-mentioned repeated calculation will be changed.
Flip from NO to YES. For this step 110
At step 111→116→, an off command signal is applied to the drive circuit 20 to stop the compressor 5.
Process 119→120. By controlling the temperature with the compressor 5 in a stopped state in this manner, the temperature inside the passenger compartment 8 gradually rises, and eventually the determination result in the temperature determination step 109 is reversed from YES to NO. The process switches to calculation processing via level correction cancellation step 112 and surplus capacity determination step 113. At this time, there is no surplus capacity, and the determination at surplus capacity determination step 113 becomes NO.
The program proceeds from the capacity level setting step 117 to a compressor on step 118, where the compressor 5 is driven and temperature control is performed.

Thereafter, starter operation determination step 103, engine low speed determination step 105, temperature determination step 109,
Corresponding to each judgment in the surplus capacity judgment step 113, respective arithmetic processing is executed to control the operation of the compressor 5 and the opening degree of the air mix damper 7.

In addition, in the above-mentioned embodiment, as a detection means for detecting parameters necessary for determining surplus capacity,
Although the one using the opening sensor 10 for detecting the opening of the air mix damper 7 has been shown, for example, at room temperature,
Sensors for outside temperature, damper opening degree, etc. may be used, and in that case, surplus capacity is determined based on whether the relationship between the respective detection signals falls within the range of pre-stored data. It's okay.

Furthermore, a case where it is determined that the outside air temperature is lower than the room temperature may be added as a condition for stopping the compressor 5, and in that case, the inside/outside air switching damper 2 may be controlled to be in the outside air introduction state.

Furthermore, the determination level of the cooling surplus capacity may be changed depending on the deviation between the outside temperature and the room temperature, the traveling speed, etc., thereby making it possible to perform efficient reduction control of the compressor drive.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram showing an embodiment of the present invention;
FIG. 2 is an arithmetic flowchart showing the arithmetic processing of the microcomputer in FIG. 1, and FIG. 3 is a functional block diagram showing the structural features of the control device of the present invention. 4... Evaporator, 5... Compressor, 6
...Heater core, 7...Air mix damper, 8
... Vehicle interior, 9 ... Room temperature sensor, 10 ... Detection means, 11 ... Outside temperature sensor, 12 ... Temperature setting device, 15 ... Mode setting device, 17 ... Microcomputer, 19 ... Opening adjustment actuator,
20... Compressor drive circuit.

Claims (1)

[Scope of Claims] 1. A ventilation duct for sending air toward the vehicle interior; a blower motor that generates an air flow toward the vehicle interior in the ventilation duct; A heat exchange means including a cooler having a cooling mechanism, which exchanges heat with the air flow and is capable of adjusting the amount of heat exchange, and various temperatures necessary to maintain the vehicle interior temperature at a target set temperature. A control signal generating means for generating control conditions, a single converting means for sequentially converting various temperature control conditions from the control signal generating means into digital values, and a storage means for respectively storing the converted digital values. an input storage means for periodically storing the various temperature control conditions as digital values; at least one of the digital values of the various temperature control conditions prepared in the storage means of the input storage means;
a first determining means that periodically determines the presence or absence of surplus cooling capacity in the heat exchange means based on the determination result and generates a first control output signal corresponding to the determination result; Periodically determining whether or not air cooling by the heat exchange means is necessary based on at least the vehicle interior temperature of the digital values of the various temperature control conditions prepared, and when cooling is necessary in response to this determination result. The determination by the first determination means is made valid, and when cooling is not required, the first control output signal is set to the first determination means.
a second determining means that sets the state to be the same as when it is determined that there is surplus capacity in the determination by the determining means; a correction amount corresponding to the determination result by the first and second determining means; Periodically calculating the adjustment control amount of the heat exchange amount in the heat exchange means based on the digital values of the various temperature control conditions prepared in the storage means, and generating a second control output signal corresponding to the result. a control amount calculating means; a first driving means for turning on and off the cooling mechanism in response to the first control output signal obtained by the first and second determining means; and the control. the second amount obtained by the quantity calculation means;
A vehicle air conditioning control device comprising: second drive means for adjusting the heat exchange amount of the heat exchange means in response to a control output signal.