JPH04118314A - Controller of air conditioner for automobile - Google Patents

Abstract

PURPOSE:To secure the temperature control with high precision at all times by correcting the calorific heat supplied to a car room to a necessary and sufficient calorific heat by increasing/decreasing the air blow faculty when the actual blow-out temperature does not become equal to the necessary blow-out temperature. CONSTITUTION:A means 101 calculates the necessary blow-out temperature. While, a means 102 detects each heat exchange faculty of an evaporator 8 and a heater core 9, and a means 103 detects the actual opening degree of an air mixing door 16, and a means 104 estimates the air temperature on the basis of the detection value. Further, the aimed opening degree of the air mixing door 16 is calculated by a means 105, and the air mixing door 16 is driven by a means 106 on the basis of the result of the calculation. Further, a means 107 calculates the standard air quantity on the basis of the above-described necessary blow-out temperature, and the above-described standard air quantity is corrected by a means 108 according to the difference. The above-described standard air quantity is corrected according to the correction air quantity, and the aimed air quantity supplied to a car room is calculated by a means 109, and the above-described blower 7 is driven by a means 110 on the basis of the result of the calculation.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a control device for an air conditioner for an automobile that performs compensation control when the temperature control state in a vehicle interior does not reach a target temperature control state.

(Prior art) As a conventional air conditioner for automobiles, for example, the
As shown in Publication No. 0931, the necessary blowing temperature to bring the temperature inside the vehicle to the target temperature is determined based on the temperature inside and outside the vehicle, and the blowing capacity is calculated based on this necessary blowing temperature to operate the blower. It is known that the position of the air mix door is determined based on the required blowing temperature and the predetermined heat exchange capacity of the evaporator or heater core, and the air mix door is driven to that position.

(Problem to be Solved by the Invention) However, according to the above technology, the position of the air mix door is set assuming that the heat exchange capacity of the evaporator and heater core is constant, and the actual blowout temperature matches the target blowout temperature. Since the air blowing capacity was uniquely determined based on this premise, the refrigerant gas that serves as the cooling source for the evaporator may leak from the cooling cycle and become insufficient, or the heat source of the heater core may become insufficient due to the cold. If the heat exchange capacity of the evaporator or heater core changes due to engine cooling water not getting sufficiently warm, the actual air temperature that is blown out and the target air temperature may not be the same.
The drawback was that it was not possible to accurately control the temperature inside the vehicle. Further, the above-mentioned drawbacks similarly occur when the air mix door fails or the control system for driving the air mix door fails.

Therefore, in this invention, even if there is a fluctuation in the heat exchange capacity of the air conditioner or a failure of the air mix door, accurate temperature control can be performed by correcting the excess or deficiency in the target amount of heat supplied to the passenger compartment. An object of the present invention is to provide a control device for an automobile air conditioner that can perform the following functions.

(Means for Solving the Problem) As shown in FIG. 1, the gist of the present invention is, as shown in FIG. , an air conditioner for an automobile equipped with a heater core 9 that heats the air, and an air mix door 16 that changes the ratio of air passing through the heater core 9 to air bypassing the heater core 9, the air conditioner having at least a vehicle interior temperature and a set temperature. A necessary blowout temperature calculation means 101 that calculates the necessary blowout temperature to bring the vehicle interior to a target temperature based on heat load conditions including;
A heat exchange capacity detection means 102 for detecting the heat exchange capacity of the evaporator 8 and the heater core 9, an actual opening degree detection means 103 for detecting the actual opening degree of the air mix door 16, and the heat exchange capacity detection means 102. An estimated blowout temperature calculation means 104 calculates an estimated blowout temperature that estimates the temperature of the air actually blown into the passenger compartment based on a value detected by the actual opening degree detection means 103; an air mix door opening degree calculation means 105 that calculates a target opening degree of the air mix door 16; and an air mix door drive means that drives and controls the air mix door 16 based on the calculation result of the air mix door opening degree calculation means 105. 10
6, a reference air volume calculating means 107 that calculates a reference air volume based on the required air outlet temperature, and a corrected air volume that calculates a corrected air volume that corrects the reference air volume according to the difference between the required air outlet temperature and the estimated air outlet temperature. A calculation means 108, a target air volume calculation means 109 that corrects the reference air volume using the corrected air volume calculated by the corrected air volume calculation means 108, and calculates a target air volume to be supplied to the passenger compartment; The present invention further includes a blower driving means 110 for driving and controlling the blower 7 based on the results.

(Function) Therefore, the air temperature actually blown into the passenger compartment is estimated by the estimated blowout temperature calculation means from the heat exchange capacity of the evaporator and heater core and the actual opening degree of the air mix door, and the reference air volume corresponding to the required blowout temperature is estimated. Correcting the reference air volume calculated by the calculation means with the corrected air volume calculated by the correction air volume calculation means based on the difference between the estimated blowout temperature and the required blowout temperature,
This calculates the target air volume to be supplied to the passenger compartment, so the required amount of heat can be supplied to the passenger compartment by adjusting the air volume, regardless of fluctuations in heat exchange capacity or inappropriate position of the air mix door. Therefore, the above-mentioned problem can be achieved.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 2, the automobile air conditioner is provided with an inside/outside air switching device 2 on the most upstream side of an air conditioning duct 1, and this inside/outside air switching device 2 has an intake in a part where an inside air population 3 and an outside air population 4 are separated. A door 5 is arranged, and this intake door 5
The air conditioning duct 1 is operated by the actuator 6.
The air introduced inside can be selected between inside air and outside air.

The blower 7 sucks air into the air conditioning duct 1 and blows it downstream, and an evaporator 8 and a heater core 9 are provided behind the blower 7.

The evaporator 8 includes a compressor 10 and a capacitor 11.
, Liquid Tank 12 and Exvin Soyon Balf 13
The compressor 10 is connected to the engine 14 of the automobile via an electromagnetic clutch 15, and is controlled on and off by connecting and connecting the electromagnetic clutch 15. - Also, the heater core 9 is configured so that the cooling water of the engine 14 circulates therethrough to heat the air.

An air mix door 16 is provided in front of the heater core 9, and by adjusting the opening degree of the air mix door 16 with an actuator 17, the air passing through the heater core 9 and the air bypassing the heater core 9 can be separated. The amount is varied so that the temperature of the blown air is controlled.

The downstream side of the air conditioning duct i is divided into a defrost outlet 18, a vent outlet 19, and a heat outlet 20, which open into the vehicle interior 21, and mode doors 22a and 22b are provided in the divided parts. Mode door 22a, 2
By operating 2b with an actuator 23, a desired blowing mode can be obtained.

25 is a vehicle interior temperature sensor that detects the temperature T INC of the air inside the vehicle; 26 is a solar radiation sensor that detects the amount of solar radiation Q;
7 is an outside air temperature sensor that detects the outside air temperature TA; 28 is an opening detector that detects the opening X0 of the air mix door; 29 is a water temperature sensor that detects the engine cooling water temperature T; 1;
A mode sensor 0 is attached to the evaporator 8 or behind it and detects the temperature of the evaporator 8 or the temperature TE of the air passing through the evaporator (hereinafter referred to as evaporator temperature), and these signals are sent to the multiplexer 31 for signal selection. The signal is inputted to the A/D converter 32 via the digital signal, where it is converted into a digital signal and inputted to the microcomputer 33.

The microcomputer 33 also includes an operation panel 34.
The output signal from is input. The operation panel 34 has an A/C switch 35 that operates the compressor 10 and an EC0N switch 36 that performs economical compressor control, and each air conditioning device enters automatic control mode when either of these switches is pressed. . In addition, the operation panel 3
4 is an OFF switch 37 that stops the operation of the air conditioning equipment.
, a DEF switch 38 that sets the blowout mode to the defrost mode, and a set temperature T in the vehicle interior. A temperature setting device 39 for setting the air blowing capacity, a blowing capacity setting device 40 for setting the blowing capacity, a blowing mode setting device 41 for setting the blowing mode other than the defrost mode, and a suction mode setting device 42 for setting the suction mode. The temperature, air blowing capacity, blowing mode, and suction mode are displayed on the microcomputer 3 via the display circuit 43.
3 is displayed on the display unit 44 controlled by the controller 3.

The microcomputer 33 is a well-known device having a central processing unit (CPU), a read-only memory (ROM), a random access memory (RAM), an input/output board (Ilo), etc. (not shown), and responds to the various input signals described above. Based on the above, the actuators 6, 17, 23, the motor of the blower 7, and the electromagnetic clutch 15 are provided with drive circuits 4, respectively.
5a to 45e to output control signals to each door 5.1
6.22a22b drive control, blower 70 rotation control, and electromagnetic crane 15 ON10FF control.

In FIG. 3, an example of a control routine for the air mix door 16 and the blower 7 by the microcomputer 33 described above is shown as a flowchart, and the following description will be made based on this flowchart.

When the microcomputer 33 is powered on, in step 50, the microcomputer 33 records heat such as the vehicle interior temperature "1NC2" outside temperature TA, solar radiation amount Q5, set temperature TD, air mix door opening Xo, water temperature T8, and evaporator temperature T6. The signals related to the load conditions are sequentially passed through multiplexers 31 and A.
/D converter 32 or directly input, RAM
is stored in a predetermined area.

Then, in the next step 52, the step 50
Based on each signal inputted in, for example, the target blowout temperature
seek.

χM-8・Tn+B-TA+C-Qs+D-T INc
+ E...Equation (1) Here, A-E is a calculation constant preset by experiment, and it means that when the value of XH is high, the demand for heating is strong.
Further, when the temperature is low, it indicates that the demand for air conditioning is strong.

After the target blowout temperature X, 4 has been calculated, the process proceeds to step 54, where the air mix door 16 is controlled as shown in FIG.

In FIG. 4, in step 80, the estimated blowing temperature XR is first calculated. Opening degree Xc of the air mix door 16
If you know l, the water temperature T, which represents the heat exchange capacity of the air conditioner, and the evaporator temperature TE, you can estimate the temperature of the blown air.
Calculate based on the formula.

XR= (F −XQ +G)(TW −TE) +
``rE...Equation (2), where F and G are calculation constants preset by experiment, and XR is the target blowout temperature in the ideal control state of the air conditioner when temperature control is stable. It is equal to or almost equal to XM.

Then, in step 82, the target blowing temperature X1. L
and the estimated blowout temperature
Determine whether or not it exists. For example, So is 2°C,
If S is within this tolerance range, it is determined that X, is approximately equal to X,4, and the position of the air mix door 16 is at an appropriate position. 16 is stopped without being driven.

On the other hand, if S is outside the allowable range (IsI > S, judge. If S>0, estimated blowout temperature XR
is smaller than the target blowout temperature X,4, and air mix door 1
Since the air mix door 16 is shifted to the full cool side (the position indicated by ■ in Fig. 2) from the position where the target blowing temperature It is driven by a predetermined amount to the position (the position shown by ■ in FIG. 2). Moreover, if S≦0, the estimated blowing temperature X+
t is larger than the target blowout temperature XM, air mix door 1
6 is shifted to the full hot example position from the position where the target blowing temperature Xa is obtained, so in this case, the process proceeds to step 92 and the air mix door 16 is driven by a predetermined amount to the full cool side position.

After controlling the air mink store 16 as described above, the process proceeds to step 56, where the target blowing temperature X? Based on the reference air volume ■1, the blower 7
Find it as the voltage value applied to the motor. This predetermined pattern has a conventionally known characteristic, and the rotation speed of the blower 7 becomes LOW in a predetermined intermediate region of X9, gradually increases as it deviates from this intermediate region, and when it deviates significantly from the intermediate region It is set to become HI.

In the next step 58, the difference S between the target outlet temperature x,4 calculated in the step 82 and the estimated outlet temperature
Based on this, a corrected air volume Vb is calculated to correct the reference air volume (2) so that a predetermined characteristic pattern set in advance through experiments as shown in step 58 is obtained. This ■ゎ is also determined as the voltage value applied to the motor of the blower 7, and in this example, ■ is almost proportional to S, and ±
With respect to the fluctuation range of 20°C, ■ has a fluctuation range of approximately ±1 (V).

In step 60, it is determined whether the target blowout temperature XM is on the HOT side (the side where X, 4 becomes larger) or on the C00L side (the side where XM becomes smaller) with the LOW region of step 56 as the boundary.

If it is determined in this step 60 that XM is on the HOT side, for example, focusing on point A shown in step 56, if XM -x+t >o, the temperature of the air actually supplied to the passenger compartment is X9 It is estimated that the lower
It is necessary to increase the air flow rate to secure the hot air volume required for XM, and if XEXR<0, the temperature of the air actually supplied to the passenger compartment is estimated to be higher than xH. , it is necessary to reduce the air volume, and therefore, the target air volume is formed by adding the corrected air volume (2) to the standard air volume (3). In particular, in this embodiment, the target air volume is L in step 56.
Step 6 to avoid falling below the OW level
2, it is determined whether v, 10V, is smaller than the voltage value corresponding to LOW level, and if it is, step 6
The process proceeds to step 4, where the target air volume is fixed at the LOW level, and if it is larger, the process proceeds to step 66, where the target air volume is determined based on equation (3).

■i + Vb (1e”)...
(3) As is clear from equation (3), the target air volume is determined by delaying the corrected air volume V with the time constant τ, and from ■1 to ■8
This prevents a sudden change to 10Vb. This time constant τ
Since the full stroke time of the air mix door 16 (the time to move from one side to the other in Figure 2 I, 92 to prevent large fluctuations in the air blowing capacity while shifting to a predetermined opening degree.

On the other hand, in step 60, Xl,l is C00
If it is determined that it is on the L side, for example, step 56
When arriving at point B shown by, if XM XR〉0,
Since the temperature of the air actually supplied to the passenger compartment is estimated to be lower than X,4, in this case excessive cooling is being performed, so in order to obtain X,4, the air flow rate must be reduced. In addition, if XMXR<O, it is estimated that the temperature of the air actually supplied to the passenger compartment is higher than X9, so it is necessary to increase the air flow rate to increase the cooling capacity. Therefore, the target air volume is formed by eliminating the reference air volume (1) and the modified air volume (2). Further, in this embodiment, in order to prevent the target air volume from falling below the LOW level, as in step 62, in step 68, Va-Vb
is smaller than the voltage value corresponding to the LOW level. If it is smaller, the process proceeds to step 72 and the target air volume is fixed to the LOW level. If it is larger, the process proceeds to step 70 and the voltage value is determined based on equation (4). to determine the target air volume.

■yo-■b (1-eTk) ...(4)
In this equation (4) as well, as in the case of equation (3) above, the correction air volume ■ of the target air volume is delayed with a time constant τ,
■Prevents sudden changes from 1 to V to -V.

Therefore, in the next period when the vehicle interior is heated, if the cooling water of the engine 14 is not sufficiently warmed due to the cold weather and the heating capacity of the heater core 9 is not sufficiently increased, step 5
6 is the target blowout temperature X1. Even if the reference air volume is determined based only on l, it will not be possible to achieve the target airflow temperature in the passenger compartment, but in such a case, the estimated airflow temperature XR calculated in step 80 will be lower than the target airflow temperature XM. Therefore, the corrected air volume (2) calculated in step 58 is added to (8), making the target air volume larger than (3), and the lack of heating capacity can be compensated for by increasing the air volume.

In addition, in the warm season when the vehicle interior is cooled, if the cooling capacity of the evaporator 8 is not sufficiently increased due to gas leakage in the cooling cycle, even if the reference air volume is determined by X and 4 in step 56, the Target blowout temperature
However, in this case, the estimated airflow temperature XR calculated in step 80 will be larger than the target airflow temperature , the target air volume becomes larger than (3), and the lack of cooling capacity can be compensated for by increasing the air volume.

Furthermore, even if the air mix door 16 cannot be driven due to a failure of the actuator 17 or the drive circuit 45b, the estimated blowout temperature X calculated in step 80
Since R deviates from the target blowing temperature XM, a correction amount of the blowing capacity is calculated in step 58 according to the difference S,
This makes it possible to compensate for the failure of the interior of the vehicle to reach the target blowing temperature due to the inability to drive the air mix door 16 by increasing or decreasing the air blowing capacity.

(Effects of the Invention) As described above, according to the present invention, when the actual blowout temperature does not reach the required blowout temperature due to fluctuations in the heat exchange capacity of the air conditioner, failure of the drive unit of the air mix door, etc. By increasing or decreasing the air blowing capacity, the amount of heat supplied to the passenger compartment can be corrected to the necessary and sufficient amount of heat, so it is possible to prevent leakage of refrigerant gas, insufficient temperature rise of the heat source, failure of the air mix door, or failure of its drive system. Even if there is a failure, accurate temperature control can still be performed.

[Brief explanation of the drawing]

Fig. 1 is a functional block diagram showing this invention, Fig. 2 is a schematic configuration diagram showing an embodiment of an automobile air conditioner according to the invention, and Fig. 3 is an air mix door and blower system using a microcomputer used in the northern region. Flowchart showing an example of control operation. FIG. 4 is a flowchart showing a specific example of the air mix door control in the same as above. 7...Blower, 8...Evaporator, 9...Heater core, 16...Air mix door, 101...Required blowout temperature calculation means, 102...Heat exchange capacity detection means, 103... Actual opening detection means, 104... Estimated blowout temperature calculation means, 105... Air mix door opening calculation means, 106... Air mix door driving means, 107
. . . Reference air volume calculation means, 108 . . . Corrected air volume calculation means, 109 . . . Target air volume calculation means, 110 . .
Blower drive means. Figure 2

Claims (1)

[Claims] A blower whose blowing capacity is varied, an evaporator which cools the air sucked in by the blower, a heater core which heats the air, and a ratio of air passing through the heater core to air bypassing it is variable. A necessary blowout temperature for an automobile air conditioner equipped with an air mix door, which calculates the necessary blowout temperature to bring the cabin to a target temperature based on heat load conditions including at least the cabin temperature and a set temperature. calculation means; heat exchange capacity detection means for detecting the heat exchange capacity of the evaporator or heater core; actual opening degree detection means for detecting the actual opening degree of the air mix door; estimated blowout temperature calculation means for calculating an estimated blowout temperature that estimates the temperature of the air actually blown into the passenger compartment based on the detected value with the opening degree detection means; an air mix door opening calculation means for calculating a target opening; an air mix door drive means for driving and controlling the air mix door based on the calculation result of the air mix door opening calculation means; a reference air volume calculation means for calculating a reference air volume based on the required air flow; a corrected air volume calculation means for calculating a corrected air volume for correcting the reference air volume according to the difference between the required air flow temperature and the estimated air flow temperature; target air volume calculation means for calculating a target air volume to be supplied to the passenger compartment by correcting the reference air volume using the calculated corrected air volume; and blower driving means for driving and controlling the air blower based on the calculation result of the target air volume calculation means. A control device for an automotive air conditioner, comprising: