JPS635287B2 - - Google Patents

Description

[Detailed Description of the Invention] Purpose of the Invention [Field of Industrial Application] The present invention relates to an air conditioner for an automobile, and particularly to an air conditioner for an automobile that controls the actuator of its temperature control system with high precision and well. .

[Prior art] In general, in automotive air conditioners, when controlling the drive of an air mix damper, for example, the required blowout temperature is calculated based on various signals from input means such as various temperature sensors and target temperature setting devices. Then, the target position (target stroke amount) of the air mix damper is determined from this required blowing temperature. Then, the deviation between the actual position of the air mix damper and the above-mentioned target position is correlated with the driving state of the air mix damper, and the air mix damper's hot valve and Control the cool valve,
Make the actual position of the air mix damper match the target position.

Conventionally, the control pattern in this type of air mix type automobile air conditioner is as shown in FIG. 1 when controlling an actuator whose maximum stroke length is about several tens of millimeters.
That is, the control pattern shown in Fig. 1 is based on the target position SW of the air mix damper (100% is MAX).
HOT and 0% correspond to MAX COOL, respectively. ) and the actual position SP (100% is MAX HOT, 0%
corresponds to MAX COOL respectively. ), the open/close states of the hot valve (HV) and cool valve (CV) are determined according to the deviation (SW-SP) from the hot valve (HV) and the cool valve (CV). In this case, for the hot valve (HV), as shown by the solid line in the figure, the deviation (SW-
+6% of SP) is the standard, while the deviation (SW
-SP) +3% as a reference, and hysteresis is provided. Similarly, for the cool valve (CV), as shown by the broken line in the figure, the transition from the off (closed) state to the on (open) state and from the on (open) state to the off (closed) state are as follows: The standard is -6% and -3% of the deviation (SW-SP), respectively.

By the way, in addition to the above-mentioned air mix type, there are also reheat type air conditioners for automobiles, and as is well known, the reheat type controls the temperature of the fluid supplied to the heater core according to the control amount of the water valve. A configuration is adopted to obtain the desired blowing temperature.

[Problems to be Solved by the Invention] In this type of reheat type automobile air conditioner, a relatively short water valve with a maximum stroke length of generally less than 10 mm is used. When such a water valve is controlled according to the control pattern shown in FIG. 1, there is a problem in that an overshoot with respect to the target position may occur due to a delay in response or inertia of the valve. Therefore, if the dead zone of the control pattern for controlling the water valve, that is, the predetermined range in which the deviation between the target position and the actual position of the actuator is small and the actuator is not normally controlled, is narrow, hunting may occur in some cases. This made it difficult to properly control the temperature.

On the other hand, if the dead zone is widened to make hunting less likely to occur, the precision of control will be lost, and the temperature inside the vehicle may deviate significantly from the set temperature, making it difficult to adjust the temperature sufficiently. However, this is not a realistic solution.

These problems are not limited to reheat-type automotive air conditioners, but also occur in air mix-type automotive air conditioners that use actuators to vary the temperature of the blown air. That was the case.

Therefore, the present invention has been made with the aim of solving these problems. Namely, the dead zone is sufficiently wide to sufficiently prevent the occurrence of overshoot as described above, and the control system is deteriorated due to the wide dead zone. It is an object of the present invention to provide an air conditioner for an automobile that can maintain control accuracy at a sufficiently high level with consideration given to the following.

Structure of the Invention [Means for Solving the Problem] In order to achieve the above object, the present invention has the following structure as a means for solving the above problem.
That is, as shown in FIG. 6, signals from a position sensor M3 that detects the actual position of the actuator M2 that changes the temperature of the air blown into the vehicle interior M1, and an input means group M4 that includes the position sensor M3 are received. A control circuit M5 for calculating a target position of the actuator M2 and outputting an actuator control command signal according to a predetermined control pattern, wherein the control circuit M5 is configured to control the target position of the actuator M2. a deviation extracting means M6 for extracting the deviation between the target position and the actual position; a determining means M7 for determining whether the extracted deviation belongs to a predetermined range of a dead zone provided in the control pattern; When the means M7 determines that the deviation belongs to the range, the actuator M2 is operated so as to bring the actual position closer to the target position.
This is the configuration of an air conditioner for an automobile characterized in that it is configured to include: an approach control means M8 that outputs a correction signal to the vehicle;

Here, the actuator M2 may be a water valve and its driving device, such as a diaphragm valve or a motor that uses positive and negative pressure sources, in the case of a reheat type automobile air conditioner; In the case of an air conditioner for commercial use, a driving device for the same as an air mix damper can be considered.

The position sensor M3 may be a differential transformer, a potentiometer, etc., and may be configured integrally with the drive device to detect the actual position of the actuator. It is also suitable to arrange for position detection.

The input means group M4 includes various quantities related to the temperature setting of the automobile air conditioner, for example,
A group of sensors that input outside temperature, solar radiation, evaporator temperature, heater core hot water temperature, etc., and a target temperature set manually by the passenger or automatically set in the case of an automatic air conditioner. There are setting devices for inputting temperature, etc.

The control circuit M5 includes a deviation extraction means M6 and a determination means M.
7. Although the structure includes the approach control means M8, each means may be realized by a discrete circuit, or may be integrated as an electronic circuit using a microcomputer. In the latter case,
Each means is realized by executing a predetermined program.

Note that the extraction of the deviation by the deviation extraction means M6 means finding the deviation between the target position obtained by receiving the signal from the input means group M4 and the actual position of the actuator detected by the position sensor M3. It means processing.

[Function] The automotive air conditioner of the present invention having the above-mentioned configuration is configured such that when it is determined that the deviation between the target position and the actual position of the actuator belongs to a predetermined range of the dead zone of a predetermined control pattern, the actuator outputs a correction signal to the actuator to bring the actual position of the actuator closer to the target position.

Such a correction signal may be a pulse signal with a predetermined time width that is output to the actuator drive circuit, but the correction signal may be output separately from the actuator control command signal, or it may be output after modifying the actuator control command signal. It's okay. Further, it is also suitable to set an upper limit on the output of the correction signal, for example, a limit on the number of outputs, in order to prevent overcontrol.

[Example] Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 2 shows an embodiment of an air conditioner for an automobile according to the present invention, which is of a reheat type. In the figure, air conditioner (air conditioner)
An inside/outside air switching damper 5 is provided at the connection portion between the air passage 2 of 1, the outside air intake passage 3, and the inside air intake passage 4. According to 6,
The flow rate is selected, then cooled by the evaporator 7, then warmed by the heater core 8,
The air is blown into the vehicle interior 10 through the outlet selected by the blowout switching damper 9. Here, the evaporator 7 is connected to a compressor 13 to which the driving force of the engine 11 is supplied and cut off via a clutch 12.
A refrigerant is supplied by a part of the refrigeration cycle 14, and cooling water for the engine 11 is supplied to the heater core 8 via a water valve 15 to cool and heat the air, respectively. .

The water valve 15 has a configuration as shown in FIG. 3, and the water valve 15 is configured as shown in FIG. The mixing ratio of the flow rate of hot water supplied from the heater core 8 side to the heater core 8 side and the flow rate of cold water that is cooled while flowing inside the heater core 8 and is supplied to the heater core 8 side again is determined, and the engine Determine the overall temperature of the cooling water.
The air intake passage of the diaphragm 16 is provided with a hot valve 19 that controls opening and closing of a communication passage with an engine intake pipe (not shown) and a cool valve 20 that controls opening and closing of a communication passage with the atmosphere.
Further, a motor pump 21 is provided in a passage leading from the outgoing valve 17 to the heater core 8.

The air conditioner 1 is equipped with various sensors for detecting operating conditions and atmospheric conditions, and condition indicating means for indicating operating conditions, and these input means are controlled by temperature control by a control circuit 31 as described below. Provide data for That is, outside temperature information from outside temperature sensor 22, inside temperature sensor 2
The inside temperature information from 7, the eye radiation information from the solar radiation sensor 28, and the target temperature information from the temperature setting device 30 are as follows.
It is used as data for calculating the required blowout temperature as described later, and the after-evaporation temperature information from the duct sensor 23 and the engine cooling water temperature information from the water temperature sensor 26 are used together with the calculated necessary blowout temperature data to calculate the target stroke amount of the actuator ( The actual position information of the actuator from the position sensor 24 is used together with the calculated target position data to calculate the control amount for the actuator.
Further, the negative pressure sensor 25, which is an example of a state detection means for detecting the operating state of the engine, uses its detected information, that is, pressure information, to determine the operating state of the actuator as described later.

Also, the switch panel 2, which is one of the condition instruction means,
9 is used to instruct various driving modes, such as automatic driving mode and manual driving mode.

Furthermore, the air conditioner 1 is provided with an abnormality indicator (not shown), which indicates when the control circuit 31 determines that there is an abnormality in the actuator.

The control circuit 31 is a well-known microprocessor.
It consists of a CPU, ROM, RAM, etc.
When the ignition switch 32 is turned on and a constant voltage is applied by the power supply circuit 33, the ignition switch 32 is turned on and a constant voltage is applied by the power supply circuit 33. It performs predetermined arithmetic processing and controls various driving means. The control procedure will be explained later based on a flowchart. The driving means controlled by the control circuit 31 includes an inside/outside air switching damper driving means 34 for driving the inside/outside air switching damper 5, a blower driving means 35 for driving the blower 6,
Water valve driving means 36 that drives the hot valve 19 and cool valve 20, and blowout switching damper driving means 3 that drives the blowout switching damper 9.
7, and a clutch 1 that disconnects and connects the transmission of driving force from the engine 11 to the compressor 13 as described above.
There are 2.

Next, the main parts of the processing operation by the control circuit 31 will be explained with reference to the flowchart of FIG.

When the ignition switch 32 is turned on, the control circuit 31 starts processing. When the process progresses and reaches step 101, step 101 is executed to sequentially take in input signals from the various sensors, ie, input means group.

Next, step 102 is executed to determine the required blowing temperature based on the various data acquired in step 101.
Calculate Tao. When calculating this temperature Tao,
The following formula: Tao=Ks・Ts−Kr・Tr−Kam・Tam−Ksun・
Tsun-C (where Ks, Kr, Kam, Ksun, and C are each constant, Ts is the set temperature or target temperature, Tr is the vehicle interior temperature, Tam is the exterior temperature of the vehicle, and Tsun is the intensity of solar radiation.) use In addition, in step 102, the required blowout temperature Tao calculated as above and the duct sensor 23 are
The stroke amount SW (target position) of the water valve 15 is calculated based on the after-evaporation temperature information obtained by the evaporator and the engine cooling water temperature information obtained by the water temperature sensor 26.

Next, step 103 is executed, and the actual stroke amount SP of the water valve 15 (actual position ), that is, (SW−
SP). Here, both the target stroke amount SW and the actual stroke amount SP are 0% MAX COOL,
100% corresponds to MAX HOT.

Next, step 104 is executed to create a predetermined control pattern as shown in the figure, that is, the deviation (SW-SP)
The driving states of the hot valve (HV) 19 and the cool valve (CV) 20 are determined based on the control characteristics of the hot valve (HV) 19 and the cool valve (CV) 20, respectively. In the control pattern shown in step 104, the deviation (SW-SP) is -
A relatively wide area ranging from 9% to 9% corresponds to the dead zone. In addition, the hatched area from -9% to -3% and the hatched area from 3% to 9% are both areas created by expanding the dead zone as described above, and the deviation (SW-SP) is When belonging to the area, the target position, that is, the deviation (SW
-SP) is provided to control the valve in the direction in which it becomes zero.

Next, step 105 is executed to determine whether the driving state of the hot valve (HV) 19 or the cool valve (CV) 20 determined in step 104 belongs to the ON region.

If the hot valve (HV) 19 or the cool valve (CV) 20 belongs to the on region, then step 106 is executed and an on command signal is sent to the water valve driving means 3 to turn on the valve 19 or 20.
Output to 6. The process then moves to a subsequent program (not shown).

On the other hand, if the hot valve (HV) 19 or the cool valve (CV) 20 does not belong to the ON region,
Next, execute step 107 to open the hot valve (HV)
In order to turn off the cool valve (CV) 19 or the cool valve (CV) 20, an off command signal is output to the water valve driving means 36. Through steps 106 and 107, the actuator control command signal is output.

Next, execute step 108 and calculate the deviation (SW−SP)
It is determined whether or not the control pattern belongs to the hatched area of the control pattern.

If the deviation (SW-SP) belongs to the shaded area, then step 109 is executed to determine whether the content of the ON/OFF counter is, for example, "3". This ON/OFF counter is a counter for counting the number of executions of the next step 110, and limits the maximum value of the number of executions set to prevent hunting between the left and right hatched areas.

Next, execute step 110, and as a correction signal,
A signal is output to turn on the hot valve (HV) 19 or the cool valve (CV) 20 for a predetermined short period of time, for example, 11 msec.

Next, step 111 is executed and the ON/OFF counter is incremented by 1.

Next, step 112 is executed to input the actual position signal SP from the position sensor 24. Then, the process returns to step 103 again to calculate the deviation (SW-SP).

On the other hand, by executing step 108 above, the deviation (SW-
If it is determined that SP) does not belong to the shaded area of the control pattern, that is, it belongs to the area from -3% to 3%, then step 113 is executed to set the target temperature from the temperature setting device 30. It is determined whether the target position SW has changed based on a change instruction or the like.

If the target position does not change, the process moves to a subsequent program (not shown).

On the other hand, if the target position has changed, step 114 is executed to clear the ON/OFF counter to initialize it in preparation for the next control. The process then moves to a subsequent program (not shown).

The flowchart of FIG. 4 has been explained above, and the processing operation will be specifically explained with reference to FIGS. 5A and 5B.

Fig. 5A shows the change over time in the stroke amount (target position SW and actual position SP) of the water valve 15, and Fig. 5B shows the control pattern of the deviation (SW-SP) corresponding to the change in the stroke amount. represents the position of

As shown in FIG. 5A, in a state where the actual position SP approximately matches the target position SW by 60% (as shown in FIG. 5A), the deviation (SW-SP) is -3 as shown in FIG. 5B. % to 3%, for example, at point a.

Then, at time _T1 , the target temperature setting is changed, and the target position SW is set to 50 by step 102 mentioned above.
When changed to %, the deviation (SW-SP) is approximately -10%
Since the position is at point b on the control pattern, the cool valve (CV) 20 is turned on.
Therefore, the actual position SP of water valve 15 is 60%.
The temperature of the fluid in the heater core 8 gradually decreases.

And when the actual position SP decreases to 56%, at that point
Since the deviation (SW-SP) becomes -6% at _T2 (point c in FIG. 5B), output processing for switching the cool valve (CV) 20 from on to off is performed in step 107.

However, the water valve 15 does not stop immediately even when the cool valve (CV) 20 is turned off, but due to overshoot, the water valve 15 reaches the position indicated by point d in FIG. 5A, that is, the indicated point d in FIG. and stop.

Point d belongs to the above-described shaded area. Therefore, steps 109, 110, 111, and 112 are executed sequentially, and the hot valve (HV) 19 is activated for a short time (here, 11 msec).
turned on. Therefore, the actual position SP of the water valve 15 rises and reaches, for example, the point e shown in FIG. 5A, and the deviation (SW-SP) reaches the point e shown in FIG. 5B.

Point e belongs to the above hatched area. therefore step
Steps 109, 110, 111, and 112 are executed in sequence, and the hot valve (HV) 19 is turned on again for a short time. For this reason, the actual position SP of the water valve 15 further increases and reaches, for example, the point f shown in FIG. 5A, and the deviation (SW-SP) reaches the point f shown in FIG. 5B.

Point f is an area other than the shaded area in the dead zone. Therefore, since the determination result in step 108 is "NO", step 110 is not executed and neither the cool valve (CV) 20 nor the hot valve (HV) 19 is turned on. Therefore, unless the target position SW changes thereafter, the actual position SP is maintained at the point f.

When the target position SW is changed in this way and the actual position SP belongs to the shaded area of the control pattern,
Processing is performed several times in the direction of eliminating the deviation (SW-SP), and the actual position SP approaches the target position SW.

In this embodiment configured as above,
The temperature of hot water supplied to the heater core 8, that is, the actual position of the water valve 15, is detected by a position sensor 24.
The deviation from the target temperature, that is, the target position of the water valve 15, determined based on information from the outside temperature sensor 22, inside temperature sensor 27, etc., is determined, and if this deviation is between 3% and 9%. between or -
When it is judged that it belongs between 3% and -9%, a correction signal (pulse width 11msec) is sent up to 3 times.
In the former case, the hot valve (HV) 19 is turned on, and in the latter case, the cool valve (CV) 20 is turned on for a short time (11 msec in this case), and the actual position of the water valve 15 is brought to the target position. In other words, it works to bring the temperature of the air blown into the vehicle interior closer to the set temperature.

Therefore, according to the automotive air conditioner of the present embodiment, the dead zone is widened (from -6% to +6%) to make hunting less likely to occur, and the water valve 15 can be precisely controlled by the correction signal. We have been able to ensure sufficient safety. As a result, good air conditioning can be achieved.

Effects of the Invention As detailed above, according to the automotive air conditioner of the present invention, in a reheat type or high precision air mix type automotive air conditioner, hunting does not occur, and the set temperature is maintained. This has the excellent effect of making it possible to sufficiently reduce the deviation and perform high-precision and good operation.

[Brief explanation of the drawing]

FIG. 1 is a control pattern diagram for explaining a conventional air conditioner for an automobile, FIG. 2 is a configuration of an embodiment of the air conditioner for an automobile according to the present invention, and FIG. 3 is a schematic configuration diagram of a water valve thereof. FIG. 4 is a flowchart for explaining the main parts of the process according to the present invention, FIGS. 5A and B are explanatory diagrams for explaining more specifically, FIG. 6 is a basic configuration diagram of the present invention,
are shown respectively. 1... Air conditioner, 5... Inside/outside air switching damper, 6... Blower, 7... Evaporator, 8...
Heater core, 9...Blowout switching damper, 15...Water valve, 22...Outside temperature sensor, 23...
Duct sensor, 24...Position sensor, 25
... Negative pressure sensor, 26 ... Water temperature sensor, 27 ...
Internal temperature sensor, 28... Solar radiation sensor, 29... Switch panel, 30... Temperature setting device, 31... Control circuit, 32... Ignition switch.

Claims (1)

[Claims] 1. A position sensor that detects the actual position of an actuator that changes the temperature of the air blown into the vehicle interior, and a position sensor that detects the target position of the actuator in response to signals from a group of input means including the position sensor. and a control circuit that calculates and outputs an actuator control command signal according to a predetermined control pattern, wherein the control circuit extracts a deviation between a target position and an actual position of the actuator. deviation extracting means; determining means for determining whether the extracted deviation belongs to a predetermined range of a dead zone provided in the control pattern; and determining, by the determining means, that the deviation belongs to the range. An air conditioner for an automobile, comprising: an approach control means for outputting a correction signal to the actuator so that the actual position approaches the target position when the actual position is moved closer to the target position. 2. The air conditioner for an automobile according to claim 1, wherein the approach control means is configured to output a correction signal by correcting the actuator control command signal. 3. The air conditioner for an automobile according to claim 1 or 2, wherein the approach control means is configured to output a correction signal for driving the actuator for a predetermined period of time. 4. The air conditioner for an automobile according to claim 3, wherein an upper limit is set for the output correction signal.