JPH08276726A - Air mix controlling device of air conditioner for automobile - Google Patents

Abstract

PURPOSE: To provide an air mix controlling device of an air conditioner for an automobile, which can effectively avoid the noise obstacle that is possibly caused by duty control without increasing costs. CONSTITUTION: A program in a micro computer 8 is changed so that when an air mix door 3 has reached a duty control prohibiting area C or D, even if S value (deviation) is within the control area (that is larger than -5 deg.C and less than -2 deg.C, or larger than 2 deg.C and less than 5 deg.C) of a duty rate of 80%, the duty control at a duty rate of 80% can forcibly be canceled and can be switched to an ON control at a duty rate of 100%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air mix controller for an automobile air conditioner.

[0002]

2. Description of the Related Art As conventional air mix control in an automobile air conditioner, an air mix is driven by a motor so that a desired air mix door opening can be accurately obtained without causing hunting. There is a door actuator whose duty is controlled.

FIG. 4 is a flow chart showing a processing procedure of a conventional air mix control by such duty control. Here, since it will be described in detail later, only a brief description will be given.

First, various data values (for example,
The set temperature, the vehicle interior temperature, the outside air temperature, the amount of solar radiation, the current air mix door opening, etc.) are input (step S1),
The target room temperature and the S value (blow-off temperature deviation) are calculated in order by a predetermined arithmetic expression (step S2, step S3).

Then, check the set temperature (step S
4) When the temperature is 18 ° C, the airmix door actuator is driven to the cool side at a duty ratio of 100% in order to set the airmix door to the full cool position (step S7), and when the set temperature is 32 ° C. Drives the air mix door actuator to the hot side at a duty ratio of 100% so as to set the air mix door to the full hot position (step S11).

As a result of the comparison in step S4, the set temperature is between 18 ° C. and 32 ° C. (for example, from 18.5 ° C. to 3 ° C.).
(1.5 ° C.), the S value is compared with ± 5 ° C. (step S5). If it is less than −5 ° C., the target temperature is lower and the deviation is larger, so the process proceeds to step S7. S
When the value is larger than 5 ° C., the target temperature is higher and the deviation is larger, so the process proceeds to step S11.

As a result of the comparison in step S5, if the S value is -5 ° C or higher and 5 ° C or lower, the S value is further compared with ± 2 ° C (step S6). By this comparison, the S value is -2
If the temperature is less than ℃, drive the air mix door actuator to the cool side at a duty ratio of 80% (step S
8) When the S value is larger than 2 ° C, the air mix door actuator is driven to the hot side at a duty ratio of 80% (step S10), and when the S value is between -2 ° C and 2 ° C, the air mix is mixed. The door actuator is held (step S9). In this way, in steps S8 and S10, duty control with a duty ratio of 80% is performed, but this causes the air mix door actuator to be driven slowly, and hunting is prevented from occurring.

When the processes of steps S7 to S11 are completed, the process returns and the series of processes from step S1 onward is repeatedly executed in a short predetermined control cycle.

[0009]

However, in such a conventional air mix control, the air mix door is at the limit position of the full cool position (air mix door opening 0%) or the full hot position (air mix door). Even if it is already fixed to the mix door opening 100%), S
When the value is higher than −5 ° C. and lower than −2 ° C. or higher than 2 ° C. and lower than 5 ° C., a drive signal with a duty ratio of 80% is output to the air mix door actuator (step S8, step S10). Duty ratio 8
Since it is necessary to repeatedly turn on and off the transistors in order to generate a 0% signal, noise is likely to occur.
Therefore, in the above case, if a signal with a duty ratio of 80% continues to be output, noise may enter the radio or the like.

The present invention has been made in view of the above problems of the prior art, and it is possible to effectively prevent a noise disturbance that may occur due to duty control without increasing the cost. An object of the present invention is to provide an air mix control device for an air conditioner for automobiles.

[0011]

In order to achieve the above object, the invention according to claim 1 is an air mix door for adjusting the temperature of blown air, and an air mix door for driving the air mix door with a motor. For an automobile that includes an actuator and control means for duty-controlling the air mix door actuator based on the values of control parameters obtained by arithmetic processing of various input signals, and for an automobile that always sets the air mix door to an optimum opening degree. An air mix control device for an air conditioner, comprising door opening detection means for detecting an opening of the air mix door, and the control means drives the air mix door actuator toward a limit position of the air mix door. At this time, the current air mix door opening detected by the door opening detecting means is set to the limit position. And cancels the duty control when it reaches the preset area as an end.

[0012]

According to the present invention having the above-mentioned structure, the door opening detecting means detects the current opening of the air mix door, and the control means uses the air mix door actuator. When driving toward the limit position (full cool position or full hot position), the current air mix door opening detected by the door opening detection means falls within a preset range with the limit position as one end. When it reaches, the duty control (control by a drive signal with a duty ratio of less than 100%) is released. As a result, when the air mix door reaches the limit position, the duty control is not always performed regardless of the value of the control parameter, so the duty ratio is 100%.
The drive signal of less than is not output continuously.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of an air mix control device for an air conditioner for a vehicle according to an embodiment of the present invention. In the same drawing, a heater core 1 for heating air by using hot water (for example, engine cooling water) is internally provided in a heater unit 1 which constitutes a main body of an air conditioner for an automobile, and an upstream side of the heater core 2 An air mix door 3 for adjusting the temperature of the blown air is rotatably attached. The air mix door 3 adjusts the ratio of the air passing through the heater core 2 to the air bypassing the heater core 2. That is,
The ratio of the amount of cold air cooled by an evaporator (not shown) provided upstream of the heater core 2 to become warm air by passing through the heater core 2 and the amount of cold air after passing through the evaporator bypassing the heater core 2 is adjusted. . In this way, the temperature of the air blown into the vehicle interior (blow-off air temperature) is determined by the mixing ratio of the cool air and the warm air determined by the opening degree of the air mix door 3. Air mix door 3 is in position A (full cool position) and position B (full hot position) in the figure.
Is freely rotated between them with the limit position. When the air mix door 3 is in the A position (full cool position),
The degree of opening is 0%, and all the cool air that has passed through the evaporator bypasses the heater core 2 and is blown directly into the vehicle interior.
Maximum cooling is demonstrated. Also, the air mix door 3 is B
When it is in the position (full hot position), the opening is 100
%, All of the cool air after passing through the evaporator is heated by passing through the heater core 2 and is blown out as warm air into the passenger compartment, so that maximum heating is achieved.

The air mix door 3 is driven by an air mix door actuator 4. The air mix door actuator 4 is a motor actuator having a built-in motor 5, and opens and closes the air mix door 3 via a link mechanism (not shown) connected to the shaft.
In addition, the air mix door actuator 4 has a built-in PBR (potentiometer balance register) 6 which is a variable resistor that moves in conjunction with the shaft, and the shaft position of the air mix door actuator 4, namely The signal of the position (opening) of the air mix door 3 is output. FIG. 2 is a characteristic diagram of PBR6. As shown in the figure, the opening of the air mix door 3 can be uniquely known from the resistance value of the PBR 6. As will be described later, the drive power is supplied to the motor 5 in the air mix door actuator 4 by the auto amplifier.

The air mix door actuator 4 is connected to the auto amplifier 7 and controlled by it. The auto amplifier 7 contains a microcomputer 8 and a motor driver 9. Further, the auto amplifier 7 detects an air conditioner switch 10 for turning on a compressor (not shown) to operate the air conditioner, a temperature adjustment switch 11 for adjusting the temperature inside the vehicle, and a temperature (room temperature) of the air inside the vehicle. Inside air sensor 12, outside air sensor 1 for detecting outside air temperature
3, a solar radiation sensor 14 that detects the amount of solar radiation, and other appropriate switches and sensors that are not shown are connected. As described above, the PBR 6 in the air mix door actuator 4 that detects the opening degree of the air mix door 3 is also connected to the auto amplifier 7. The microcomputer 8 in the auto amplifier 7 processes the input signals from the switches 10, 11, the sensors 12, 13, 14 and the PBR 6 to generate a control signal for operating the air mix door actuator 4. , To the motor driver 9. The motor driver 9 supplies a predetermined drive power to the motor 5 in the air mix door actuator 4 according to a control signal from the microcomputer 8. At that time, as described later, in controlling the air mix door actuator 4 by the auto amplifier 7, duty control is performed in order to improve the accuracy of the opening degree of the air mix door 3, that is, the accuracy of the air mix (temperature control). To do. Although not shown, the air mix door actuator 4 has a built-in pattern switch, and when the air mix door 3 reaches the limit position, that is, the full cool position (position A) and the full hot position (position B), respectively. The output from the motor driver 9 does not reach the motor 5 only in the direction toward the side.

FIG. 3 is a flow chart showing a processing procedure of air mix control by the microcomputer 8. This processing procedure is a modification of the conventional processing procedure shown in FIG. Specifically, the difference is that the judgments of step S26 and step S27 are newly added to the processing procedure shown in FIG. In the following, the contents of each process will be described more specifically.

First, each sensor 12 to
The signals from 14, PBR 6 and the temperature control switch 11 are input, and the current vehicle interior temperature, outside air temperature, solar radiation amount, air mix door opening, and set temperature are respectively recognized by the microcomputer 8 (step S20).

Then, the microcomputer 8 calculates the target room temperature by a predetermined arithmetic expression (step S21). Here, depending on the case, various corrections, such as a correction considering the characteristics of the vehicle itself, a correction considering the link characteristics for the air mix door opening based on the PBR value, a correction taking into account the temperature adjustment characteristics according to the outlet mode, etc. Done.

Then, a predetermined arithmetic expression (vehicle heat balance expression)
Thus, the blown air temperature deviation (= target temperature-current temperature) (referred to as S value) as a control parameter is calculated (step S22). This S value also includes various correction values depending on the case. As will be described later, controlling the temperature of the blown air,
That is, the control of the air mix door opening degree is performed by the deviation control based on the S value.

Then, the microcomputer 8 checks the current set temperature input in step S1 (step S23),
For example, when the temperature is 18 ° C., the air mix door actuator 4 is set to the cool side (that is, in the direction toward the A position) with a duty ratio of 100% in order to set the air mix door 3 to the full cool position (position A). When driven and when the set temperature is, for example, 32 ° C., the air mix door actuator 4 is moved to the hot side (that is, to set the air mix door 3 to the full hot position (position B)).
Control signals for driving with a duty ratio of 100% (in the direction toward the B position) are generated and sent to the motor driver 9 (steps S28 and S32). This allows
The air mix door actuator 4 is a motor driver 9
Powered by a 100% duty ratio from the motor, they are quickly driven to the cool side or the hot side, and the air mix door 3 is fixed to the full cool position (position A) or the full hot position (position B), respectively. Will be. Here, the duty ratio of 100% means 1 of the pulse signal.
This means that the ratio of the on time to the cycle is 100%, that is, only the on signal is output.

In this embodiment, the air mix door 3 is set to the full cool position and the full hot position when the set temperatures are 18 ° C. and 32 ° C., respectively. Of course, is not limited to the above values.

As a result of the judgment in step S23, the set temperature is between 18 ° C. and 32 ° C. (for example, from 18.5 ° C. to 3 ° C.).
(1.5 ° C.), the S value obtained in step S22 is compared with, for example, ± 5 ° C. (step S24). As a result of this comparison, when the S value is less than −5 ° C., the target temperature is lower and the deviation is large, so the process proceeds to step S28 in order to eliminate the deviation quickly, and when the S value is larger than 5 ° C. Since the target temperature is higher and the deviation is larger, the process proceeds to step S32 to eliminate the deviation similarly. As a result, the air mix door actuators 4 are supplied with electric power from the motor driver 9 at a duty ratio of 100% and are quickly driven to the cool side or the hot side, respectively, and the air mix doors 3 are respectively directed to the optimum opening degree. And quickly approach.

As a result of the comparison in step S24, when the S value is -5 ° C. or higher and 5 ° C. or lower, the S value is further increased to, for example, ±.
It is compared with 2 ° C. (step S25). As a result of this comparison, when the S value is −2 ° C. or higher and 2 ° C. or lower, it is determined that the air mix door 3 is within the target temperature control range, and the air mix door actuator 4 is held. A control signal is generated and output to the motor driver 9 (step S30). As a result, the air mix door actuator 4 is held at that position, and the air mix door 3 is held at that opening.

It should be noted that ± 2 ° C. compared in step S25
The range within is a temperature control range to be achieved as a target, and is not limited to that value. In general, the narrower the range, the higher the accuracy of temperature control, but on the other hand, the smaller the control range, the more likely hunting occurs. Good. In this embodiment, since the target temperature control range is set within a narrow range of ± 2 ° C, the S value (deviation) is less than -5 ° C as described later in order to suppress the occurrence of hunting. Is greater than −2 ° C. or greater than 2 ° C. and less than 5 ° C., a duty ratio of 8 is applied to the air mix door actuator 4.
0% duty control is performed to slowly drive the air mix door actuator 4, and the air mix door 3
The target temperature control range (deviation is within ± 2 ° C) is slowly approached.

When the S value is less than -2 ° C as a result of the comparison in step S25, that is, when the S value is larger than -5 ° C and less than -2 ° C, the current air mix detected by PBR6 is further detected. Depending on the door opening, it is determined whether the air mix door 3 is within a preset duty control prohibition region C (step S26). Duty control prohibition area C here
Is a duty control (that is, duty control) to prevent the motor driver 9 from continuously outputting drive power having a duty ratio of 80% even though the air mix door 3 has reached the full cool position (position A). 80% of the ratio
2) from the full cool position (opening 0%) in this embodiment (FIG. 2).
reference). However, this duty control prohibition region C is for checking whether or not the air mix door 3 has reached the full cool position (position A), so only when the air mix door actuator 4 is driven to the cool side. Applied. In this embodiment, the width of the duty control prohibition region C is set to 5%, but this is because the detection error of the PBR 6 is taken into consideration, and the width is not limited to this value. If the detection error of the PBR 6 is small, it is possible to make the width of the duty control prohibition region C narrower, and conversely, if the detection error is larger, the width will need to be wider. If the full-cool position (opening degree 0%) can be accurately detected without error, the width of the duty control inhibition region C can be set to 0%.

As a result of the determination in step S26, when the air mix door 3 is in the duty control prohibited area C while moving to the cool side, the air mix door 3 reaches the full cool position (position A). If it is determined that the motor driver 9 is present, the duty output from the motor driver 9 is switched from 80% to 100% in step S28. In other words, the duty control of 80% where the noise is likely to occur is canceled and the duty ratio 100 where the noise is less likely to occur is released.
Switch to% ON control. Air mix door 3
As described above, the power supply from the motor driver 9 (only when driving to the cool side) is cut off by the pattern switch when reaches the limit position (full cool position).

On the other hand, as a result of the determination in step S26, when it is not the case where the air mix door 3 is in the duty control prohibition region C while moving to the cool side,
In order to prevent hunting, judging that the air mix door 3 has not reached the full cool position (position A),
A control signal for driving the air mix door actuator 4 to the cool side at a duty ratio of 80% is generated and output to the motor driver 9 (step S29). This allows
The air mix door actuator 4 is a motor driver 9
The electric power is supplied to the cool side more slowly than when the duty ratio is 100%, and the air mix door 3 is in the target temperature control range (deviation within ± 2 ° C). You will slowly approach.
In this embodiment, the duty ratio in this case is 80%.
Although it is set to, of course, it is not limited to this value. Considering the target temperature control range, etc., the air mix door 3 prevents hunting.
It may be set to an appropriate value so that the moving speed of can be obtained.

On the other hand, as a result of the comparison in step S25, when the S value is larger than 2 ° C., that is, when the S value is larger than 2 ° C. and less than 5 ° C., it is detected by PBR6 as in the process of step S26. Based on the current opening degree of the air mix door, it is determined whether or not the air mix door 3 is within a preset duty control prohibition region D (step S27). The duty control prohibition region D here is for preventing the drive power having the duty ratio of 80% from being continuously output from the motor driver 9 even though the air mix door 3 has reached the full hot position (position B). Duty control (that is, control by an output signal with a duty ratio of 80%)
In the present embodiment, the opening degree of the air mix door is set within a range of 5% from the full hot position (opening degree 100%) as in the case of step S26. In other words, the air mix door opening is 95% to 100
The range of% (full hot position) is the duty control prohibition area D (for the above, refer to FIG. 2). However, in this duty control prohibited area D as well, since it is to check whether the air mix door 3 has reached the full hot position (position B), it is possible to determine whether the air mix door actuator 4 is driven to the hot side. Only applicable. Note that the duty control prohibition region D is not limited to the width of 5% as in the case of the duty control prohibition region C described above.

As a result of the determination in step S27, when the air mix door 3 is in the duty control prohibited area D while moving to the hot side, the air mix door 3 reaches the full hot position (position B). If it is determined that the motor driver 9 is present, the process proceeds to step S32, and the duty output from the motor driver 9 is switched from 80% to 100%. In other words, the duty control of 80% where the noise is likely to occur is canceled and the duty ratio 100 where the noise is less likely to occur is released.
Switch to% ON control. Air mix door 3
As described above, the electric power supply from the motor driver 9 (only when driving to the hot side) is cut off by the pattern switch when reaches the limit position (full hot position).

On the other hand, as a result of the determination in step S27, when it is not the case where the air mix door 3 is in the duty control prohibition region D while moving to the hot side,
It is determined that the air mix door 3 has not reached the full hot position (position B), and a control signal for driving the air mix door actuator 4 to the hot side at a duty ratio of 80% is generated and output to the motor driver 9. Yes (step S31). As a result, the air mix door actuator 4 has a duty ratio of 80% from the motor driver 9.
100% duty ratio to the hot side by receiving power supply at
Driven more slowly than in the case of the air mix door 3
Will slowly approach the target temperature control range (deviation within ± 2 ° C).

Steps S28 to S32 described above
When the process of step S20 is completed, the process returns and the series of processes from step S20 onward is repeatedly executed in a short predetermined control cycle.
As a result, the air mix door 3 is always set to the optimum opening, and the target temperature control is obtained.

Therefore, according to the present embodiment, when the air mix door 3 reaches the duty control prohibited region C or D, that is, the full cool position (A position) or the full hot position (B position) is reached. If it is determined that the S value (deviation) is 80% duty ratio control range (-
Even when the temperature is higher than 5 ° C. and lower than −2 ° C. or higher than 2 ° C. and lower than 5 ° C.), the duty control of 80% duty ratio is forcibly released and the duty ratio is set to 100%. Since the control is switched to ON control, an output with a duty ratio of 80% is likely to be generated even if the air mix door 3 reaches the full cool position (position A) or the full hot position (position B). 80% duty cycle
It is possible to effectively prevent a noise disturbance that may occur due to the duty control of the above.

Further, in order to obtain the above-mentioned effect, it is not necessary to add any component, and it can be dealt with only by changing (adding) the program stored in the microcomputer 8.
There is no increase in cost.

[0034]

As described above, according to the first aspect of the invention, when the air mix door reaches the limit position, the duty control (duty ratio less than 100% is always performed regardless of the value of the control parameter. Control by the drive signal of No.) is released, the drive signal with a duty ratio of less than 100% does not continue to be output, and a noise problem that may occur due to the duty control with a duty ratio of 80% can be prevented only by changing the program. It can be effectively prevented.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an air mix control device for an automobile air conditioner according to an embodiment of the present invention.

FIG. 2 PBR characteristic diagram

FIG. 3 is a flowchart showing a processing procedure of air mix control by a microcomputer.

FIG. 4 is a flowchart showing a processing procedure of conventional air mix control.

[Explanation of symbols]

 3 ... Air mix door 4 ... Air mix door actuator 5 ... Motor 6 ... PBR 7 ... Auto amplifier (control means) 8 ... Microcomputer 9 ... Motor driver

Claims (1)

[Claims] 1. An air mix door (3) for adjusting the temperature of blown air, an air mix door actuator (4) for driving the air mix door (3) with a motor (5), and various input signals are calculated. A vehicle having a control means (7) for duty-controlling the air mix door actuator (4) based on the value of the control parameter obtained by processing, and always setting the air mix door (3) to an optimum opening degree. An air mix control device for an air conditioner for a vehicle, comprising door opening detection means (6) for detecting an opening of the air mix door (3), and the control means (7) includes the air mix door actuator (4). ) Is driven toward the limit position of the air mix door (3), the current air mix door opening detected by the door opening detecting means (6). Air mix control apparatus for an automobile air-conditioning system and cancels the duty control when it reaches the preset region of the limit position as one end.