JPH02175320A - Airconditioner for car - Google Patents

Abstract

PURPOSE:To reduce power consumption by allowing an airconditioner as per existing invention to exert optimum cooling ability through combination of the compressor capacity with the wind quantity from a blower, which minimizes the sum of the power of compressor and the power of blower, and by setting the target values for these capacity and wind quantity in conformity to a specified rule. CONSTITUTION:An airconditioner as per existing invention includes No.1 sensing means A, which senses the cooling load in the cabin of a car, and No.2 sensing means B to sense the conditions of varying the cooling ability of the airconditioner. A memory means C with a plurality of rules stored is furnished, and thereby the target value (a) associate with the capacity of compressor and the target value (b) for the wind quantity from a blower are set on the basis of the cooling load and the above- mentioned conditions so that the sum of the powers of the compressor 2 and blower 6 becomes minimum when the airconditioner is operating in the cooling mode, and a setting means D sets the target values (a), (b) from respective degrees of confidence in the rules. No.1 control means E controls the capacity of the compressor 2 according to the target value (a), while No.2 control means F controls the wind quantity from the blower 6 according to the target value (b).

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vehicle air conditioner, and more particularly to reducing power consumption of a vehicle air conditioner.

(Prior Art) Conventionally, for example, Japanese Unexamined Patent Publication No. 178833/1983 discloses an air handling unit capacity control device for controlling air conditioning conditions in buildings and factories. Data on required power, data on heat exchanger air flow rate versus blower required power, and data on heat exchanger air side heat output versus heat exchanger water flow rate versus heat exchanger air flow rate are stored.

Then, the hot air output data on the air side of the heat exchanger at the temperature-controlled location is detected, and the combination that minimizes the sum of the required power data of the pump required power and the blower required power corresponding to this heat output data is stored. Select from the data provided. By controlling the amount of water flowing through the heat exchanger and the amount of ventilation through the heat exchanger based on each of the selected data, wasteful consumption of electrical energy is prevented.

[Invention tries to solve it! ! l! Subject: However,
In the case of a vehicle air conditioner, the cooling load in the vehicle interior and the cooling capacity of the vehicle air conditioner vary depending on external conditions such as outside air temperature, outside air humidity, and vehicle speed. Here, the cooling capacity of this air conditioner can be expressed by the amount of air passing through the evaporator and the enthalpy difference between the inlet and outlet of the evaporator.

For example, when an air conditioner introduces outside air, the higher the outside air temperature or outside air humidity, the higher the front wind speed of the compressor, and the lower the front temperature, the higher the cooling capacity of the air conditioner. becomes larger, and the enthalpy at the evaporator outlet becomes smaller, that is, the outlet temperature becomes smaller. The cooling capacity of the air conditioner varies depending on other factors as well, and of course the cooling load also varies depending on various factors. If the cooling capacity changes, the combination of compressor capacity and blower air volume that minimizes the sum of the compressor power and the blower power when achieving the cooling capacity also changes.

Here, there is a non-linear relationship between the cooling capacity of the air conditioner and each factor that changes this cooling capacity, and furthermore, the above optimal combination for a given cooling capacity may vary depending on the conditions of the air conditioner. Become. For this reason, as in the conventional case, storing all the correspondence relationships as data requires a very large memory capacity, and when achieving a certain cooling capacity, the power of the compressor and the power of the blower must be combined. To select from the stored data the combination of compressor capacity and blower air volume that minimizes the sum of
Complex and enormous calculations must be performed.

The present invention has been made in view of the above points, and takes into consideration the cooling capacity of an air conditioner that varies depending on various factors.
The cooling capacity of the air conditioner is controlled to a cooling capacity that corresponds to the cooling load in the vehicle interior, and the capacity of the compressor and the blower are determined such that the sum of the power of the compressor and the power of the blower is minimized when achieving this cooling capacity. An object of the present invention is to provide a vehicle air conditioner that can determine the combination of air volume and air volume from hourly rules and functions.

(Means for Solving the Problems) In order to achieve the above object, the vehicle air conditioner according to the present invention cools the air sent by the blower using the evaporator, and In a vehicle air conditioner equipped with a variable capacity compressor capable of controlling cooling capacity according to 2
a detection means for the compressor so that the sum of the power of the compressor and the power of the blower is minimized when the vehicle air conditioner exhibits the cooling capacity required by the cooling load; a plurality of rules that set a target value related to capacity and a target value of air volume of a blower based on the cooling load and the conditions; and a set of predetermined ranges for the cooling load and the conditions in the plurality of rules. a storage means for storing a function for setting a confidence level in the divided set, and calculating a confidence level for each of the plurality of rules;
Setting means for setting a target value related to the capacity of the compressor and a target value for the air volume of the blower based on the confidence level; and a setting unit for controlling the capacity of the compressor according to the target value related to the capacity of the compressor. The air blower is configured to include a first control means and a second control means for controlling the air volume of the blower according to a target value of the air volume of the blower.

(Operation) According to the above configuration, first, the cooling load in the vehicle interior and the conditions that change the cooling capacity of the vehicle air conditioner are detected.From this information, the air conditioning The device is controlled so that it exhibits a cooling capacity according to the cooling load inside the vehicle.At this time, the cooling capacity exerted by the air conditioner is determined by the compression ratio that minimizes the sum of the power of the compressor 411 and the power of the blower. This is achieved by a combination of the capacity of the compressor and the air volume of the blower.Here, the target value related to the capacity of the compressor and the blower's yiA in the above combination are
The target value of m is set by a plurality of rules that are executed based on conditions that vary the cooling load in the vehicle interior and the cooling capacity of the vehicle air conditioner. In the plurality of rules, the cooling load in the vehicle interior and the conditions that change the cooling capacity of the air conditioner are each divided into predetermined sets, and the plurality of rules are used so that these sets realize the above-mentioned effects. are associated. For this reason, a target value related to the capacity of the compressor and a target value for the air volume of the blower are set by simple calculations using multiple rules and functions, and if control is performed according to these target values, the compressor power and The sum with the power of the blower can be minimized.

〔Example〕

Hereinafter, a first embodiment of the present invention will be described based on the drawings.

In FIG. 1, 2 is a variable capacity compressor, which is driven by an internal combustion engine l.
The capacitance changes depending on an external signal. 3
is a condenser, which liquefies the high-pressure gas refrigerant discharged from the compressor 2. 4 is an expansion valve that reduces the pressure of the high-pressure refrigerant liquefied by the condenser 3 and expands it. Reference numeral 5 denotes an evaporator, which is installed in the air conditioning duct 10 and cools the passing air by evaporating the atomized refrigerant. These form the refrigeration cycle of the air conditioner. Furthermore, air conditioning duct 1
0 includes a blower fan 6 that controls the amount of air passing through the evaporator 5, a temperature sensor 11 that detects the temperature of the air that has passed through the evaporator 5, and an outside air intake and inside air Wi ring. an internal/external air switching damper 7 that switches between internal and external air, and an internal combustion engine 1
A heater that heats the passing air using cooling water.
8 and an air mix (A/M) damper 9 for controlling the amount of air heated by the heater 8, and these constitute an air conditioner.

For these components, an electronic control unit (ECU) 1
3 is a compressor control device 14 based on the seed information.
, outputs a command signal to the inside/outside air switching device 15, and the blower fan drive device, and executes the inside/outside air switching control by the inside/outside air switching damper 7, the capacity control of the compressor 2/2, and the air volume control n by the B1 blower fan 6. . And ECtJ1
3 mutually controls the cooling capacity and power consumption of the air conditioner through these controls so that the sum of the power of the compressor 2 and the power of the blower fan 6 is minimized. In addition, 1
7+: l/M DanharriI control device F teari, ECtJ
The position of the A/M damper 9 is controlled by the CPU 130.

The ECU 13 includes a CPU 13a as a setting means for performing calculations necessary for control, a ROM 13b as a storage means for storing a plurality of rules and functions for inference, a RAMI 3c for storing input/output data, calculation results, etc. , an input section 13d and an output section 13e, including an outside air temperature sensor 12a, an outside air temperature sensor 12b, a cabin temperature sensor 12c, a solar radiation sensor 12e, and a temperature setting device 12 [,
Based on detection signals from the vehicle speed sensor 12g and the internal combustion engine rotation speed sensor 12h, internal/external air switching control is executed and the cooling load in the vehicle interior is calculated.

Then, considering this cooling load as the cooling capacity that the air conditioner should exhibit, how should the capacity of the compressor 2 and the air volume of the blower fan 6 be combined to achieve this cooling capacity with the minimum power consumption? infer.

Here, in order to reduce the power consumption of the air conditioner, ■
Reducing the heat load into the vehicle interior and lowering the cooling capacity that the air conditioner should exert; - Optimizing the capacity of the compressor 2, the air volume of the blower fan 6, etc. when the air conditioner exerts a certain cooling capacity. One possible method is to ask for a match.

Therefore, first, a method for reducing the heat load into the vehicle interior will be explained.

In general, the cooling load in a vehicle interior includes a load due to heat passing through the roof and floor, a solar load due to sunlight, a ventilation load due to heat entering through ventilation, and a portion of the heat generated by the engine and heat generated by the human body. It is determined by the internal load due to the heat generated internally. Here, the load due to passing heat, the solar radiation load, and the internal load are uniformly determined depending on the conditions, but the ventilation load can be controlled by changing the amount of ventilation and switching between inside and outside air.

Figure 2 shows the changes in each case when switching between inside and outside air in a vehicle and changing the amount of ventilation when introducing outside air.
The cooling load is calculated when the difference between the outside air temperature and the inside temperature of the vehicle changes.

In Fig. 2, the solid line indicates the case of internal air circulation, and the dotted line indicates the ventilation amount when outside air is introduced, that is, ff1l is small (LO
), and the - point I\ line indicates a large amount of air when outside air is introduced (
Hl) case is shown. The temperature inside the vehicle at this time was 25°C, and the humidity was 50%R1! , and shows the case where there is no sunlight outside the office and the outside humidity is 50% R11.

If the outside air temperature is higher than the inside temperature of the vehicle (outside air temperature - room temperature > O), when outside air is introduced, heat due to the temperature difference between the outside air temperature and the inside temperature of the passenger compartment will enter the main compartment, so it will be faster than when inside air circulation is used. (In the case of internal air circulation, air with a temperature of 25°C and humidity of 50%R is circulated.) Also, the larger the air volume, the greater the heat that enters the cabin due to ventilation. As a result, the cooling load also increases.

Conversely, when the outside air temperature is lower than the vehicle interior temperature (outside air temperature - room temperature ≦O), the cooling load is smaller when outside air is introduced compared to when inside air W1 is used.

In the above example, we explained the case where the humidity inside and outside the vehicle is the same, but if the temperature inside and outside the vehicle is different, the enthalpy inside and outside the vehicle (determined by temperature and humidity)
Depending on the difference, you can decide whether to recirculate inside air or introduce outside air. In other words, if outside air enthalpy > cabin enthalpy, then inside air is introduced, and when outside air enthalpy ≦ cabin enthalpy, outside air is introduced. Cooling load can be reduced.

Next, a method for finding the optimal combination of compressor capacity and blower fan air volume in an air conditioner will be described.

FIG. 3 shows the change in power consumption when the capacity of the compressor and the air volume of the blower fan are mutually changed so that the air conditioner exhibits a predetermined cooling capacity in a certain vehicle. In addition, Figure 3 assumes that the cooling capacity exerted by the air conditioner is constant at 1500 kcal/h, and the outside temperature is 3.
0°C1 outside humidity is 50%l? lI, the vehicle interior temperature is 25''C1, and the vehicle interior humidity is 50%R1+,
The figure shows the case where the vehicle interior is air-conditioned by internal air circulation.

Usually, the cooling capacity Q is defined by the following equation based on the enthalpy difference between the population of the evaporator and the outlet, and the evaporator passing wind Mva.

Q=Cp-r ·Va (Ta-Ta) where the conditions at the evaporator inlet are constant (Cp, r.

Assuming that Ta is constant), the cooling capacity Q is determined by the evaporator passing air Iva and the evaporator outlet temperature fTe.

Considering the case where the cooling capacity Q is controlled to be constant, if the evaporator passing air volume Va is increased, the evaporator outlet temperature To must be increased accordingly. in this case,
In order to increase the weight Va passing through the evaporator, it is necessary to increase the power of the blower motor, but the evaporator outlet temperature Te
Since this increases, the refrigerant evaporation pressure in the evaporator can be increased, which allows the capacity of the compressor to be reduced.

As described above, the power consumption of the blower fan increases as the air flow rate Va passing through the evaporator increases, but the power consumption of the compressor decreases as the evaporator outlet temperature Te increases.

Therefore, as shown in Fig. 3, when the air conditioner exerts a predetermined cooling capacity, the power consumption of the blower fan (dotted line in Fig. 3) increases due to the increase in the evaporator air flow rate ■a, and the evaporator outlet temperature Optimum air volume Va・and outlet temperature that minimizes the sum of compressor power consumption (Figure 3 - dot-dashed line) that decreases due to increase in Tc (that is, the total power shown by the solid line in Figure 3 is minimized) A combination with To exists.

Here, when the cooling load inside the vehicle interior and the cooling capacity of the air conditioner change depending on external conditions such as outside air temperature, outside air temperature, and vehicle speed, the power consumption of the compressor also changes accordingly.

For example, when the power of the compressor fluctuates as shown from the dashed line to the dashed two dotted line in Figure 3, the sum of the power of the compressor and the power of the blower fan (total power) is It changes like this. At this time, the optimal combination of wind 11Va and outlet temperature Te that minimizes the total power also changes. Therefore, in order to find the above-mentioned optimal combination while taking into consideration external conditions such as outside air temperature, outside air humidity, and vehicle speed, in this embodiment, fuzzy reasoning is used to calculate the target value of the evaporator passing air volume Va and the pressure. A target value of the evaporator outlet temperature Te is calculated as a target value related to the capacity of 81 machines.

Next, the control procedure of this embodiment will be explained based on the flowchart of FIG. 4.

In FIG. 4, in step 100, detection signals from each of the sensors t2a to t2h shown in FIG. 1 are manually input. In step 110, the outside air temperature Tag and the vehicle interior temperature T'' are compared, and if it is determined that the outside air temperature Tag is higher, the process proceeds to step 120, where the inside air W1 ring is selected. If it is determined that the outside air temperature Tag is lower, the process proceeds to step 130, and outside air introduction is selected.In step 140, each sensor 12a to 12h
A vehicle heat load Qao as a cooling load defined as the following equation is calculated using the detection signal from the 0 and each coefficient determined according to the conditions.

QaomK, 2Tr+KITam±K a to Tset+
5 to S r + ・Vr (Tagm-Tr) +C
Tset: Set temperature Tr: Vehicle interior temperature T
a Cod: Outside temperature ST - 1 to 1 K for solar radiation.

: Coefficient determined by the physical properties of the vehicle interior and air ■r; Ventilation f
1 (varies depending on the inside/outside air) C: Correction constant Here, the coefficients and 4 are constants determined experimentally so that the vehicle interior temperature approaches the set temperature, and the coefficient ≦ indicates the outside air temperature. Tag is a function set to increase as the outside air temperature RHam increases. In other words, K
s - g (Tag, Rf (am)), and as the enthalpy of outside air increases, the influence of the term Ks Vr (Tag - Tr), which is related to the cooling capacity of the air conditioner, on the vehicle heat load Qao increases. It should be noted that when determining the coefficient, the humidity inside the vehicle R
Hr is usually in the range of 30%R1-50%RH, and its fluctuation is small, so it is not considered in this example, but the coefficient is a function of outside air temperature Tag, outside air temperature RHas, and cabin humidity RHr ( Ks=g' (Ta+w, R
Mash, RHr)), and may be set to increase as the outside air temperature Tag and outside air temperature RHam increase, or to decrease as the vehicle interior humidity RHr increases.

In step 150, the vehicle heat load Qao and the temperature difference T between the interior and exterior of the vehicle as a condition for varying the cooling capacity of the air conditioner are determined.
(= Tag - Tr), a target value of the air volume of the blower fan 6 that minimizes the power consumption of the air conditioner is calculated by fuzzy reasoning.

In step 160, similarly to step 150, the target value of the evaporator outlet temperature Te is calculated by fuzzy reasoning. In step 170, for the inside/outside air switching device 15,
A command signal is output to switch to internal air circulation or outside air introduction, and a command signal is output to the blower fan drive device 16 according to the target air volume Va. Then, a command signal corresponding to the target evaporator outlet temperature Te is output to the compressor control device 14, and the compressor control device 14 uses the command signal to specify the evaporator outlet temperature Te detected by the temperature sensor 11. The capacity of the compressor 2 is feedback-controlled so as to approach the temperature.

This compressor control device is, for example, disclosed in Japanese Unexamined Patent Publication No. 62-94
748 is applicable, and
The device disclosed in Japanese Patent Application Laid-Open No. 58-13962 may be one in which a fixed reference voltage is changed in accordance with a command signal.

Here, the inference method in the fuzzy inference of each target value performed in step 150 and step 160 will be explained.

First, the inference of the target value of the scenery of the blower fan 6 will be explained. The target value of the air volume of the blower fan 6 is set by a rule executed based on the vehicle heat load Qao and the temperature difference T between the inside and outside of the vehicle. As shown below, this rule is expressed not by a mathematical formula but by a logical formula (for example, if II'), if the vehicle heat load Qao is small, and (&) the temperature difference T is small, (Tllll!N) , air volume V
(e.g., by reducing a), and the wind [I V a that minimizes the sum of the power of the compressor 2 and the power of the blower fan 6 is set to be inferred. In this embodiment, the air volume Va is Lo, M, , M, , H! A blower fan 6 that can be switched to four stages is used.

〔rule〕

F (Qao=SA&T-5^) THEN (Va
=SA)F (Qao=SN&T-LA)↑! IEN
(Va = MM)F (Qao-MM&T=SA)
TH [! N (Va −MM)F (Qao=ML&T
-LA) THEN (Va -LA)F (Qao=
LA&T-5^) TIIEN (Va =L^)F
(Qao=LL&T-LA) TIIBN (V
a-LL) In the above rules, vehicle heat load Qao
is a set of six sizes: “small (S^),” “slightly small ($8),” “medium (MM),” “slightly large (ML)′≠ “very large (LL).” The temperature difference T is “small (S^)” and “large (LA)”.
(The classification stage can be set to any number of stages, but in this example, the vehicle heat load Qao is set to 6 stages, and the temperature difference T is set to 2 stages.) A set divided into fuzzy variables SA,
SM, MM, ML.

As shown in FIG. 5, for LA and LL, the range of the set and the confidence level in that range are set by the respective membership functions. Input variables Q, ~Q & indicating the range of the set set by this membership function
, Tl, and Tt are determined depending on the conditions. In this embodiment, for each of internal air circulation and outside air introduction, the input variables Q, -Q are functions of the internal combustion engine rotational speed Nc and the vehicle speed ■, and are expressed as Q-f. (Nc, V)), and input variable T+
, Tt are predetermined constants.

Here, input variables Q1 to Q! , Tl, and Tt are shown below.

[When introducing outside air]

Q+-a++ (a, X I Nc-a, l-a,)+
a, xVQt-Q++b Qs-C++ (-c, XNc+c,)+c, XVQi
-Q3+d Qs-e1+ (atXNc+esl +ea 10VQ
i-Q, +f TI-0, Tt-g [during internal air circulation] Ql-h1+(htXINc hsl h4)+h
sXVQg=Q++1 Q! -JI+ (JzXNc+Js)+J4XVQ a
"Q 3+ k Qs"1++ (j!tXNc+1x) +la+VQ
&-Qs+m Tl-0,'r□-n Thus, the input variables Q, ~Q, are the rotational speed N of the internal combustion engine
It is set to become smaller as c becomes higher. This means that when the compressor is made to perform the same work, the capacity of the compressor decreases as the rotational speed Nc increases, but the higher the rotational speed Nc, the greater the loss due to friction etc. and the greater the power consumption. This is because the efficiency of However, Q during outside air introduction and inside air circulation is set to be the smallest when the rotational speed Nc reaches a predetermined rotational speed am,b=. This means that the rotational speed Nc is the predetermined rotational speed a! +h3
This is because when this happens, the capacity of the compressor is controlled to be the smallest, and at this time the power consumption of the compressor is the largest. In this way, as the rotational speed Nc increases, or as the rotational speed Nc increases to a predetermined rotational speed a5r.
If the input variables Q and -Q are set to be the smallest when the value becomes 1, the fuzzy variables SA to LL will be set accordingly.
The overall range of changes to lower levels. For this reason, even if the value of the vehicle heat load Qao is the same, the confidence that applies to a higher set of fuzzy variables 5A-LL increases, and the inferred wind 11Va tends to increase. Furthermore, the input variables Q, ~Q, are set to increase as the vehicle speed (2) increases. This is because as the vehicle speed V increases, the front wind speed of the condenser increases,
This is because the cooling capacity of the air conditioner is improved.

Here, the procedure for inferring the target value of the air volume of the blower fan 6 will be explained with reference to the flowchart of FIG.

In step 600, it is determined whether internal air circulation or outside air introduction was selected in step 110 of the flowchart of FIG. 4. If internal air circulation is selected, the process proceeds to step 610.
are set based on the condition of internal air circulation, the rotational speed Nc of the internal combustion engine, and the vehicle speed ■. In step 620, input variables TI, TI are set to predetermined constants corresponding to the internal air circulation.

Further, if it is determined in step 600 that outside air introduction is selected, the process proceeds to step 630, where the input change Q, .
Q& is set based on the condition that outside air is introduced, the rotational speed Nc of the internal combustion engine, and the vehicle speed V. In step 640, the input variables T, , T, are set to predetermined constants corresponding to when outside air is introduced.

In step 650, a set to which the vehicle heat load Qao calculated in step 140 of the flowchart of FIG. 4 applies is selected. In step 660, a set to which the temperature difference T (-Tag-Tr) between the inside and outside of the vehicle applies is selected. In step 670, a rule that includes both the vehicle thermal load Qao and the set of temperature differences T selected in steps 650 and 660, respectively, is selected and executed. In step 680, the magnitude of the certainty factor of the wind 11Va calculated according to the rule executed in step 670 is compared. In step 680, the wind fiVa is set based on the certainty factor determined to be large in the comparison of the certainty factor magnitudes performed in step 670.

A specific example of the inference based on the above flowchart is shown in FIG. 7. In FIG. 7, the vehicle heat load Qao is 1160 kcal/
h. Target airflow 11Va of the fan 6 when the temperature difference T between the inside and outside of the vehicle is 5°C (this is a direct example. Since the temperature difference T is 5°C, the outside air temperature Ta
tm>vehicle interior temperature Tr, therefore, internal air circulation is selected, and correspondingly the input variables QI-Qh, Tr,
T* is set.

As shown in Fig. 7, the vehicle heat negative 7QjQao corresponds to two sets: "small (SA)' and "slightly small C3H)", and the temperature difference T is "small (SA)" and "large (LA)". This applies to two sets.

Then, rules (2) and (2) that include both of these sets are selected and executed.

In rule ■, vehicle heat tLN Qao (-116
0kcal/h) is small (SA) is 0
．． 4. The confidence that the temperature difference T (-5°C) is small (SA) is 0.67. As a result, the confidence level that ff1li V a is small (SA), that is, Lo, is the smaller of the two confidence levels described above, that is, 0.4. Similarly, in rule ■, the vehicle heat load is slightly small (SN
) is 0.6, the certainty that the temperature difference T is large (LA) is 0.33, and the air volume Va is medium (M
M), that is, the confidence level of M is 0.33. As a result, the one with the greater certainty calculated by rule (2) and rule (2), that is, the wind ILO, is adopted as the inference result.

Similarly to the air volume of the blower fan 6, the target value of the evaporator outlet temperature To is also set by a rule executed based on the vehicle heat load Qao and the temperature difference T between the inside and outside of the vehicle. This rule is shown below, and the membership functions of the respective fuzzy variables SA, SM, MM, ML, and LA are shown in FIG. 8. This rule is similar to the rule for inferring the target value of the air volume Va of the blower fan 6. In addition, when the air conditioner exerts a certain cooling capacity, the evaporator outlet temperature Te is set so that the sum of the power of the compressor 2 and the power of the blower fan 6 is the minimum, which corresponds to the capacity of the compressor. ing.

(Rules) ■IP when introducing outside air (Qaoss+SA&T=SA) THEN
(Te-SA)IP (Qao=MM & T=SA)
TIIEN (Te-5A)IP (Qao=LA
& T=S^)THEN (To-5A)IP (Qa
o=LA & T-5M) TItEN (Te-5A
)IP (Qao-5A & T-5M) TIIEN
(Te-MW)IP (Qao=MM & T=S
M)TIIEN(Te=SA)IP (Qao-5A
& T=MM) TII[! N (Te-
LA) IP (Qao-MW & T-MW) TI
IEN (Te=MM)IP (Qao=LA &
T=MM) ↑III! NCTe=SA)I
P (Qao=S^ & T-ML) THfi
N (Te-LA) Summer P (Qao-MM &
T=ML) TIIHN (Te=MM)IP
(Qno-LA & T-ML) TIIE
N (Te=LA) ■ IP for internal air circulation (Qao=S^) TIIEN (Te=
LA) IP (Qao=MM) TIIEN (Te-
MM) IP (Qao=LA) THEN (Te-5
A) As mentioned above, rules for setting the target value of the evaporator outlet temperature Te are established for both outside air introduction and inside air circulation, and in the case of inside air circulation, the rules for setting the target value of the evaporator outlet temperature Te are set separately for the vehicle heat load Qao. Based on this, the evaporator outlet temperature Te is set.

The procedure for inferring the target value of the evaporator outlet temperature Te will be explained with reference to the flowchart of FIG.

In step 900, it is determined whether internal air circulation or outside air introduction is selected, and in the case of internal air circulation, the process proceeds to step 910. Input variable Q
, ~Q, are set.

In step 920, an applicable set of vehicle heat loads Qao is selected, and in step 930, a rule including the set is selected and executed. In step 940, the target value of the evaporator outlet temperature Te is set by taking a weighted average of the reliability calculated by the executed rule.

If it is determined at step 900 that outside air should be introduced, the process proceeds to step 950, where input variables Q, -Qv are set based on the condition that outside air is introduced, the rotational speed Nc, and the vehicle speed (2). In step 960, a set to which the vehicle heat load Qao applies is selected, and in step 970, a set to which the temperature difference T applies is selected based on input variables T, ~Th, which have been determined in advance in correspondence with the introduction of outside air. . In step 980, rules that both include the sets selected in steps 960 and 970, respectively, are selected and executed.

In step 990, the evaporator outlet temperature Te is set by taking a weighted average of the reliability calculated by the executed rule.

A specific example of the inference based on the above flowchart is shown in Fig. 1O. Fig. 1θ shows that the vehicle heat load is 1160 kcal/h.
, shows an example of inferring the target value of the evaporator outlet temperature Te when internal air circulation is selected because the temperature difference T between the inside and outside of the vehicle is 5 degrees.

First, the values of the input variables Q, .about.Q, are set as shown in FIG. 1O, depending on conditions such as the internal air 1a ring, the rotational speed Nc of the internal combustion engine, and the vehicle speed .

In rule ■, vehicle heat load Qao is small (SA)
The confidence that the outlet temperature To is large (LA), that is, 15"C, is 0.14. Similarly, in rule ■, the vehicle heat load Qao is medium (MM). The confidence that the outlet temperature Te is medium (MM), that is, 10°C, is also 0.86.The confidence that is obtained by rule ■ is 0.1.
4 and the confidence level 0.86 obtained from rule (2), the outlet temperature T6 becomes 10.7°C, which is the inference result of the target value of the evaporator outlet temperature To.

Here, the shape of the membership function and the range of the set of fuzzy variables can be changed arbitrarily depending on the situation. Conversely, even if the inference rules are the same, just changing the membership function or fuzzy variables is possible. It is possible to perform control that can respond to all conditions. Furthermore, the inference rules themselves can be easily added, deleted, or changed.

In this way, in this embodiment, the air volume Va of the blower fan and the evaporator outlet temperature To are inferred based on the vehicle heat load Qao and the temperature difference T between the inside and outside of the vehicle. here,
The vehicle heat negative 1Qao is not only the cooling load inside the vehicle but also the term (Ks ・Va (Ta
g-Tr)). Furthermore, the amount of heat dissipated from the capacitor is predicted from the temperature difference T between the interior and exterior of the vehicle, and the state of the refrigeration cycle is predicted based on this. And these vehicle heat loads Qa.

The plurality of rules executed based on the temperature difference T and the temperature difference T are the air volume of the blower fan 6 that achieves the cooling capacity that the air conditioner should exhibit and that minimizes the sum of the power of the compressor 2 and the power of the blower fan 6. The combination of Va and the evaporator outlet temperature Te is set to be inferred. In other words,
For example, as shown in Fig. 3, the power of the compressor 2 changes from the one-dot chain line to the two-dot chain line, and as a result, the air volume Va at which the total power is minimum changes from the solid line to the three-dot chain line. When the vehicle heat load Qao and temperature difference T
The detected value represents the fluctuation in the power of the compressor 2.

The plurality of rules described above are set so that when such a fluctuation in the power of the compressor occurs, the inferred air volume Va becomes smaller.

In this embodiment, when cooling the vehicle interior, the cooling capacity required by the cooling load in the vehicle interior is achieved with the minimum power consumption.

For this reason, the outlet temperature To of the evaporator and the air volume (1) of the blower are mutually controlled, and by the combination thereof, the air conditioner exhibits the necessary cooling capacity. In other words, the air that has passed through the evaporator is sent directly into the vehicle interior without being heated by the heater 8, so basically in this embodiment
The M damper 9 is fixed at the MAX C00L position. However, in some cases, it may not be possible to accurately detect the vehicle heat load Qao, and if a compressor that can only perform stepwise capacity control is used, the desired evaporator outlet temperature Ta may not be obtained. . In such a case, in addition to the flowchart of FIG. 4, the steps shown in FIG. 13 are executed. That is, at step 1000, the temperature difference Tyset between the set temperature Tset and the vehicle interior temperature T
tr is calculated, and in step 1010 the temperature difference Tys
It is determined whether eL-,r is smaller than 0 degrees. As a result, if the set temperature Tsat is lower than 0 degrees, that is, higher than the vehicle interior temperature Tr, the process proceeds to step 1020, and the A/M
A damper control device 17 controls the position of the A/M damper 19 . Further, when the set temperature Tset is lower than the vehicle interior temperature Tr, the process proceeds to step 1030, and the position of the A/M damper 9 is maintained at the MAX C00L position.

Next, a second embodiment of the present invention will be described.

In the first embodiment, the vehicle heat load Qao and the temperature difference T between the inside and outside of the vehicle are detected, and based on these detected values, when the air conditioner exerts a certain cooling capacity, the power of the compressor and the power of the blower are adjusted. was controlled so that the sum of On the other hand, in the second embodiment, each target value is calculated by fuzzy reasoning so that the sum of the compressor power, the blower power, and the condenser fan power is minimized.
It is for controlling. Incidentally, since the capacity control of the compressor and the air volume control of the blower fan are performed in the second embodiment in the same manner as in the first embodiment, their explanations are omitted here.

In the second embodiment, the target value of the air volume Vac of the condenser fan is the vehicle heat load Qao, the vehicle speed ■, and the outside air temperature Tag.
It is calculated by fuzzy inference based on The rules for this fuzzy inference are shown below, and
The membership function is shown in FIG.

〔rule〕

IF (Qao=SA & V=SA) Ti1E
N (Vac-MM)IP (Qao-LA &
V-SA) Ding 11BN (Vac=LA)IP
(Qao=SA & V-LA) Ding 11E
N (Vac-5A)IP (Qao=L, A &
V=LA & Tact-LA) TIIEN
(VacmiMW) IF (Qao=LA & V-LA & T
ag-SA)↑IIIEN(Vac=SA) In the rules shown above, vehicle heat load Qa.

The cooling capacity that an air conditioner should exhibit is P2! l! is,
Furthermore, the speed of the cooling air applied to the condenser is estimated from the vehicle speed (2), and the outside air temperature Tag is regarded as the front temperature of the condenser, and the capacity of the condenser, that is, the capacity of the refrigeration cycle, is inferred from this information. If the vehicle already has sufficient capacity for the heat load Qao, the air volume Vac of the condenser fan is set to a small value,
On the other hand, the above rules are set so that when the air volume Vac is insufficient, the air volume Vac is increased. Therefore, by fuzzy inference performed based on these conditions, it is possible to set a target value for the air volume Vac of the condenser fan that minimizes the power consumption of the air conditioner including the power of the condenser fan.

In the first embodiment, switching control between inside and outside air was executed based on the temperature difference between the inside and outside of the vehicle interior, but it may also be executed based on the enthalpy difference between the inside and outside of the vehicle interior.

In addition, although the compressor in the first embodiment was one in which the capacity of the compressor was changed in response to an external signal, it is also possible to It is sufficient if the ability of the controller can be controlled by an external signal.

Further, in the first embodiment, the outlet temperature TO of the evaporator was used as the target value related to the capacity of the compressor, but the refrigerant pressure discharged from the evaporator may also be used. Similar to the temperature Te, a target value of the refrigerant pressure is calculated by fuzzy inference, and feedback control B is performed by comparing this target value with the actual refrigerant pressure.

In addition, in the first embodiment, the target value of the evaporator outlet temperature Ta and the target value of the blower fan wind JiVa were both determined by fuzzy [1jA, but only one of them was determined by fuzzy reasoning, and the other one was determined by fuzzy reasoning. Cooling capacity Q
It may be calculated from the definition formula (Q=Cp-r-Va(Ta-Te)), that is, steps 150 and 160 of the flowchart in FIG. 4 can be calculated as shown in FIGS. 12(a) and (6). Change to In the example shown in FIG. 12(a), the air volume ■a is inferred by fuzzy reasoning in step 150, and the outlet temperature Te is calculated from the air flow 1iVa in step 160. Further, in the example shown in FIG. 12(b), step 16
Infer the outlet temperature 1゛e at 0 by fuzzy reasoning,
At step 150', the air volume Va is calculated from the outlet temperature Te. In addition, when the target value of the outlet temperature Te is determined by fuzzy reasoning and the target value of the blower fan's wind 111Va is determined by calculation, it is better to be able to change the blower fan's wind fiVa continuously. Te is calculated by fuzzy reasoning, and this outlet temperature Ta
When calculating the air volume Va according to the previous two, the set IR amount (Lo, Ml.

M2. This is because it is conceivable that the value will be an intermediate value between Hi). Note that, of course, the blower fan of the first embodiment may be one that can continuously change the air volume.

〔Effect of the invention〕

As described above, according to the present invention, even if the cooling capacity of the air conditioner fluctuates due to various factors, the sum of the power of the compressor and the blower can be minimized, and the cooling capacity of the air conditioner can be adjusted to a minimum. The cooling capacity can be controlled according to the indoor cooling load. Furthermore, the combination of the capacity of the refrigeration cycle and the air volume of the blower to realize the cooling capacity at this time can be determined from simple rules and functions.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing the configuration of the first embodiment of the present invention, and FIG.
The figure is a characteristic diagram showing the cooling load when the temperature difference between the inside and outside of the vehicle changes, and Figure 3 is the sum of the compressor power and the blower power when the air conditioner exerts a certain cooling capacity. FIG. 4 is a flowchart showing the control procedure of the first embodiment, FIG. 5(a),
(b) and (C) are diagrams representing membership functions in fuzzy inference, Figure 6 is a flowchart showing the inference procedure in fuzzy inference, Figure 7 is an explanatory diagram showing an example of inference by fuzzy inference, and Figure 8 ( a), (b),
(C) is a diagram showing the membership function in fuzzy tlI theory, Fig. 9 is a flowchart showing the inference procedure in fuzzy inference, Fig. 10 is an explanatory diagram showing an example of lI theory using fuzzy inference, Fig. 11 (a), ( b), (C)
, (d) is a diagram representing the membership function in fuzzy inference of the second embodiment, FIG. 12 (a), (b),:
# is a flowchart showing control procedures of other embodiments;
FIG. 13 is a flowchart showing the air mix damper control procedure for correction, and FIG. 14 is a configuration diagram showing an outline of the present invention. ! ... Internal combustion engine, 2... Compressor, 3...'0 compressor, 4... Expansion valve, 5... Evaporator, 12a... Outside air temperature sensor. 12b...Outside air humidity sensor, 12c...Interior temperature sensor, 12f...Temperature setting device, 12e...Solar radiation sensor, 12h...Internal combustion engine rotation speed sensor, 12g...
...Vehicle speed sensor, 13...Electronic side fil device, 14.
. . . Compressor control device, 15 . . . Inside/outside air switching device, 16 . . . Follower fan drive device. Representative Patent Attorney Takashi Okabe Title Procedure Amendment (Traveling) May/3, 1999 Takari 63 Ariyotoki (Nohara City No. 1331309 2 Name of Invention Person Who Amends Vehicle Air Conditioning System Case) Related Patent ■ Kokorome, 1-1 Showa-cho, Kariya-shi, Aichi Prefecture (426) Nippondenso Co., Ltd. Representative: Nakatabeyo 1-1-7 Showa-cho, Kariya-shi, Aichi Prefecture 448 Contents of amendment Drawing Correct as follows: (1) Correct Figure 7 as shown in the attached sheet (I corrected the position of the figure number outside the figure). (2) Correct Figure 10 as shown in the attached sheet ( (The position of the figure number has been corrected to outside the figure). (3) Delete one of the two sheets of "Figure 13" attached to the application, and amend the other as shown in the attached sheet. Figure 1 3

Claims (4)

[Claims] (1) In a vehicle air conditioner equipped with a variable capacity compressor that cools air sent by a blower using an evaporator and can control the cooling capacity of the evaporator, a first system that detects the cooling load in the vehicle interior a second detecting means for detecting a condition that changes the cooling capacity of the vehicle air conditioner;
a detection means for the compressor so that the sum of the power of the compressor and the power of the blower is minimized when the vehicle air conditioner exhibits the cooling capacity required by the cooling load; a plurality of rules that set a target value related to capacity and a target value of air volume of a blower based on the cooling load and the conditions; and a set of predetermined ranges for the cooling load and the conditions in the plurality of rules. a storage means for storing a function for setting a confidence level in the divided set, and calculating a confidence level for each of the plurality of rules;
Setting means for setting a target value related to the capacity of the compressor and a target value for the air volume of the blower based on the confidence level; and a setting unit for controlling the capacity of the compressor according to the target value related to the capacity of the compressor. 1. A vehicle air conditioner comprising: a first control means; and a second control means for controlling an air volume of the blower according to a target value of the air flow of the blower. (2) In the vehicle air conditioner according to claim 1, either a target value related to the capacity of the compressor or a target value of the air volume of the blower is set according to the plurality of rules, and the set value is set according to the plurality of rules. A vehicle air conditioner characterized in that one target value is used to calculate another target value. (3) In a vehicle air conditioner equipped with a variable capacity compressor that cools air sent by a blower using an evaporator and can control the cooling capacity of the evaporator, a first device that detects the cooling load in the vehicle interior. a second detecting means for detecting a condition that changes the cooling capacity of the vehicle air conditioner;
and detecting means for controlling the cooling load so that the sum of the power of the compressor and the power of the blower is minimized when the vehicle air conditioner exhibits the cooling capacity required by the cooling load. and a setting means for setting a target value related to the capacity of the compressor and a target value for the air volume of the blower from the conditions; and a setting means for controlling the capacity of the compressor according to the target value related to the capacity of the compressor. 1. A vehicle air conditioner, comprising: first control means; and a second control procedure for controlling the air volume of the blower according to a target value of the air volume of the blower. (4) In a vehicle air conditioner equipped with a variable capacity compressor that cools air sent by a blower using an evaporator and can control the cooling capacity of the evaporator, a first controller that detects the cooling load in the vehicle interior a detection means; a second detection means for detecting a condition that changes the cooling capacity of the vehicle air conditioner; a first setting means for setting a degree of certainty; a second setting means for dividing the conditions for varying the cooling capacity into sets in a predetermined range and setting a degree of certainty for the conditions in the set; When the air conditioner exerts the cooling capacity required by the cooling load, the capacity of the compressor and the air volume of the blower are such that the sum of the power of the compressor and the power of the blower is minimized, relationship setting means for setting a relationship between the sets classified by the first and second classification means, a target value related to the capacity of the compressor, and a target value for the air volume of the blower, and the cooling load is detected. a first selection means for selecting a set to which this cooling load applies; a second selection means for selecting a set to which this condition applies when a condition that changes the cooling capacity is detected; computing means for selecting the relationships that include both of the sets respectively selected by the second selection means and computing confidences in each set; a target value setting means for setting a target value related to the capacity of the compressor and a target value for the air volume of the blower; a first control means for controlling the capacity of the compressor according to the target value related to the capacity of the compressor; A second controller that controls the air volume of the blower according to a target value of the air volume of the blower.
A vehicle air conditioner comprising a control means.