JPH06171352A - Air-conditioner for vehicle - Google Patents

Abstract

PURPOSE:To eliminate the waste of power and carry out the stable operation of a cooling cycle by performing the optimum control of a condenser fan. CONSTITUTION:In an air-conditioner for a vehicle, a cooling cycle is formed by piping-connecting a refrigerant condensing condenser 17 disposed near a radiator 1 for cooling engine cooling water and cooled by a cooling fan and by traveling air, a variable displacement compressor 16 driven by an engine, and an evaporator 13 disposed in an air-conditioning duct. This air-conditioner is provided with a means 57 for detecting the temperature of engine cooling water, a means 58 for detecting the travel speed of the vehicle, a means 3 for detecting the displacement of the variable displacement of compressor 16, a means 4 for computing the rotating speed of the condenser cooling fan 2 by fuzzy inference on the basis of the cooling water temperature, travel speed and compressor displacement from these detecting means and also a specified control rule, and a fan control means 5 for driving-controlling the condenser cooling fan 2 so that the rotating speed becomes the rotating speed computed by fuzzy inference.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle air conditioner having a variable capacity compressor and a condenser cooled by a cooling fan during a cooling cycle.

[0002]

2. Description of the Related Art Conventionally, as a control technology of a cooling fan of a condenser which constitutes a cooling cycle of an air conditioner, Japanese Patent Laid-Open No. Sho 5 has been proposed.
The thing described in 9-209912 is known.

This device has two fans, a radiator fan and a condenser fan, and selectively drives only one of the fans or both of them depending on the cooling water temperature of the engine and the usage of the cooler. It also drives a fan.

[0004]

In the above-mentioned conventional device,
When it is determined that more than a predetermined amount of heat must be dissipated due to the usage of the cooler (air conditioner) or engine cooling water temperature, the condenser cooling fan is controlled to be turned on and off. Since it changes subtly depending on the control state of the variable displacement compressor, it is not possible to perform optimal heat dissipation control in consideration of both heat generation and heat dissipation with rough control such as the above-mentioned conventional technology.
There were problems such as wasting power and reducing the stability of the cooling cycle.

In consideration of the above circumstances, the present invention optimally controls the condenser fan to eliminate waste of power,
It is an object of the present invention to provide a vehicle air conditioner that enables stable cooling cycle operation.

[0006]

In order to solve the above-mentioned problems, the present invention is arranged near a radiator 1 for cooling engine cooling water and is cooled by a cooling fan 2 together with traveling wind as shown in FIG. Condenser 17 for condensing refrigerant
And a variable displacement compressor 1 driven by the engine
6 and an evaporator 13 arranged in the air conditioning duct 10.
In a vehicle air conditioner in which a cooling cycle is configured by connecting and, the means 57 for detecting the "cooling water temperature" of the engine, the means 58 for detecting the "traveling vehicle speed" of the vehicle, and the variable capacity Means 3 for detecting the "capacity" of the compressor 16 and the cooling water temperature from these detecting means,
Means 4 for fuzzy inferring the rotational speed of the condenser cooling fan 2 based on the traveling vehicle speed, the compressor capacity, and a predetermined control rule, and a fan control means 5 for driving and controlling the condenser cooling fan 2 so as to attain the inferred rotational speed. And are characterized by having.

[0007]

In the apparatus of the present invention, the inference means 4 fuzzy infers the rotational speed of the condenser fan using the engine cooling water temperature detection value, the vehicle speed detection value and the compressor capacity control value as input variables. In other words, the fuzzy inference is executed with the antecedent parameter (input) of the fuzzy inference as water temperature, vehicle speed, and compressor capacity, and the consequent parameter (output) as the rotation speed of the condenser fan.

Fuzzy inference outputs an inference result according to a fuzzy rule determined based on an empirical rule or the like. The procedure of the method is as follows, for example. However, since there are three antecedent variables here, the antecedent variables are "compressor capacity" and "vehicle speed", respectively, and the antecedent variable is "condenser fan rotation speed". The second fuzzy operation is performed in parallel or in order, with the variables of the condition part being "vehicle speed" and "water temperature" and the consequent part variable being "condenser fan rotation speed", and the final inference result "capacitor "Fan rotation speed" is output.

In the first fuzzy operation, first, according to each fuzzy rule, the grade of the variable "compressor capacity" of the antecedent part is called by the membership function given in advance (also called the degree of belonging to the fuzzy label or the membership value). Then, the grade of another variable "vehicle speed" is obtained, and the minimum value of both grades is taken. This process is called antecedent process. Next, as consequent processing,
The membership function of "condenser fan rotation speed" on the output side is truncated at the grade above, and the trapezoidal output obtained by the trimming is ORed and the center of gravity is obtained.

Similarly in the second fuzzy operation, first, the grade of the variable "vehicle speed" in the antecedent part is obtained by the membership function given in advance according to each fuzzy rule,
Next, another grade of "water temperature" is obtained, and the minimum value of both grades is taken. Next, the membership function of the "capacitor fan rotation speed" on the output side is subjected to the head cut processing at the above grade, and the trapezoidal output obtained by the head cut processing is ORed to obtain the center of gravity.

Next, the two fuzzy operation outputs are compared with each other, and the larger value is set as the final output "condenser fan rotation speed".

This inference method is disclosed in, for example, Japanese Patent Laid-Open No. 2-927.
This is an application of a method known in Japanese Patent No. 63, etc. Other inference methods may be adopted separately.

In this device, the rotation speed of the condenser fan is determined according to the compressor capacity, the traveling vehicle speed, and the engine cooling water temperature, so that the condenser fan is operated under optimal conditions.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 2 shows a schematic configuration of the vehicle air conditioner of the embodiment. In this device, an inner air inlet 10A and an outer air inlet 10B are formed in a bifurcated manner at the most upstream portion of the air conditioning duct 10, and an intake door 11 is provided at the divided portion. By controlling the opening and closing of the intake door 11, the ratio of the inside air and the outside air to be introduced into the air conditioning duct 10 can be adjusted.

The air conditioning duct 10 is provided with a blower fan 12, an evaporator 13, an air mix door 14 and a heater 15 in order in the order from the downstream side. The evaporator 13, together with the compressor 16, the condenser 17, the receiver tank 18 and the expansion valve 19, is pipe-connected to form a cooling cycle.

As the compressor 16, a swash plate type variable displacement compressor is used here. Briefly described, the compressor 16 has a capacity determined by an inclination angle of a swash plate (oscillating plate), an inclination angle of the swash plate determined by pressure in the crank chamber, and a pressure in the crank chamber determined by a substantial opening of the solenoid valve 16A. Depends on

That is, when the supply current (capacity control signal) Isol to the solenoid valve 16A is increased, the compressor capacity is reduced, and when the supply current Isol to the solenoid valve 16A is decreased, the compressor capacity is increased. Here, solenoid valve 1
The capacity is 0% when the supply current Isol to 6A is the maximum, and the capacity is 100% when the supply current Isol is the minimum. The external variable displacement compressor 16 is driven by the force transmitted from the engine 70,
Drive control is performed by connecting and disconnecting the electromagnetic clutch 16B.

Further, the air mix door 14 adjusts the ratio of the air passing through the heater 15 and the air not passing through the heater 15 according to the opening degree. Then, the air that has passed through the heater 15 and the air that does not pass through the heater 15 are mixed on the downstream side of the heater 15 so that the temperature of the air is adjusted and the air is blown into the vehicle from the air outlet.

The rear end portion of the air conditioning duct 10 has a defrost outlet 2 for blowing air toward the inner surface of the windshield.
1, a vent outlet 22 that blows air toward the occupant's face, and an outlet 23 that blows air toward the occupant's feet.
The mode doors 24, 25, 2 are provided for 1, 22, 23, respectively.
6 is provided. And these mode doors 24,
The blowing mode can be changed by selectively opening and closing 25 and 26.

The intake door 11, the air mix door 14, and the mode doors 24 to 26 described above are controlled to open and close by actuators (not shown). The actuators, the blower fan 12, the solenoid valve 16A of the compressor 16, and the electromagnetic clutch 16B are driven and controlled by the control unit 50.

Further, the condenser 17 is arranged in the vicinity of the radiator 1 for cooling the cooling water of the engine, and is cooled by the electric cooling fan (also called "condenser fan") 2 together with the traveling wind. Has become. The cooling fan 2 is also drive-controlled by the control unit 50.

The control unit 50 includes the actuators, the blower fan 12, and the solenoid valve 16 described above.
A, a drive circuit that drives the electromagnetic clutch 16B, the cooling fan 2, and the like, a microcomputer that supplies a control signal to each drive circuit, and A / connected to the microcomputer.
It includes a D converter and a multiplexer.

In the A / D converter in the control unit 50, a solar radiation sensor 52 for detecting the amount of solar radiation Qsun entering the passenger compartment, an outside air temperature sensor 53 for detecting the outside air temperature Ta, and a representative passenger compartment An inside air temperature sensor 54 that detects a temperature (vehicle temperature) Tr, a temperature setter 55 that sets a temperature (set temperature) Tset in the vehicle compartment, and an air temperature (evaporator temperature) T immediately after passing through the evaporator 13.
The duct sensor 56 for detecting e, the water temperature sensor 57 for detecting the temperature Tw of the cooling water for the engine, and the vehicle speed sensor 58 for detecting the traveling vehicle speed V of the vehicle are connected to each other, and the data from the respective sensors are stored in the microcomputer. It is supposed to be entered. In this embodiment, the outside air temperature sensor 53, the inside air temperature sensor 54, the temperature setter 55, and the solar radiation sensor 52 correspond to the heat load detecting means 2 shown in FIG.

Next, the contents of the control performed by the control unit 50 of the air conditioner will be described with reference to the flowchart of FIG.

When the control routine shown in FIG. 3 starts, first in step 101, the detection signals (Tset, Tr, Ta, Qsun, Te, Tw, V) of various sensors are input. Next, at step 102, the target temperature is detected based on the vehicle interior temperature Tr detected by the vehicle interior temperature sensor, the outside air temperature Ta detected by the outside air temperature sensor, the set temperature Tset by the temperature setter, and the solar radiation amount Qsun detected by the solar radiation sensor. The blowout temperature Xm can be calculated by the following equation: Xm = A.Tset-B.Tr-C.Ta-D.Qsun +
Calculate with E. However, A to D are constants, and E is a correction term.

Next, the routine proceeds to step 103, where the evaporator target temperature Te 'is calculated based on the target outlet temperature Xm, and at step 104 the deviation between the evaporator outlet air temperature Te detected by the duct sensor and the evaporator target temperature Te'. Based on (Te-Te '), the compressor capacity control amount Isol is calculated by PI, and a capacity control signal is output to control the capacity of the compressor.

For example, the operation current is calculated based on the following equation. Isol = IP + II (t) However, the proportional term “IP” = the manipulated variable corresponding to the proportional operation, and is determined according to the deviation ΔT between the actual temperature Te of the evaporator and the target temperature Te ′. Integral term “II (t)” = manipulation amount corresponding to the integration operation at time t = II (t−Δt) + ΔII (t) ΔII (t) = increment corresponding to the integration operation, and Te and Te ′ It is determined according to the deviation ΔT. Δt = control interval (here, 0.5
sec).

Thereafter, the step of fuzzy calculation of the drive voltage signal Bv for determining the rotation speed of the condenser fan 2 is started. In this fuzzy calculation, a first fuzzy rule shown in FIG. 4 and a second fuzzy rule shown in FIG. 6 (these are determined by experience or experimental results obtained) are given.

The first fuzzy rule uses "compressor capacity control value Isol" and "vehicle speed V" as antecedent variables,
It is a rule that prescribes the relationship when "capacitor fan voltage Bv" is used as a consequent part variable, and IF (preceding part) to TH
It is specified in EN (Consequent part) format. Also, regarding these antecedent part variables and consequent part variables, FIG.
The membership functions shown in (b) and (c) are given.

The second fuzzy rule is "vehicle speed V".
And "water temperature Tw" as the antecedent variable and "condenser fan voltage Bv" as the antecedent variable, this is a rule that prescribes the relationship, in the form of IF (the antecedent) to THEN (the antecedent). It is prescribed. Further, the membership functions shown in FIGS. 7A, 7B, and 7C are given to these antecedent part variables and consequent part variables.

However, each code (fuzzy label) used here has the following meaning. PL: Large in the positive direction PM: Medium in the positive direction PS: Small in the positive direction ZR: Almost “0”

In the first step 105 of the fuzzy calculation, the antecedent variables "compressor capacity control value Isol", "water temperature Tw", and "vehicle speed V" are calculated according to the membership function for each rule relating to the condenser fan rotation speed control. Determine the grade wi1. For the first fuzzy operation, the first fuzzy rule in FIG. 4 and the membership function for the first fuzzy operation in FIG. 5 are used. For the second fuzzy operation, the second fuzzy rule in FIG. 6 and the membership function for the second fuzzy operation in FIG. 7 are used.

Next, at step 106, from the output side membership function for the first fuzzy operation of FIG.
The capacitor fan voltage Bvi is calculated for each grade of each rule, the center of gravity is calculated in step 107, and the position of the center of gravity is set as the first fuzzy calculation output value Bv1.

Next, at step 108, from the output side membership function for the second fuzzy operation of FIG.
The capacitor fan voltage Bvi is calculated for each grade of each rule, the center of gravity is calculated in step 109, and the position of the center of gravity is set as the second fuzzy calculation output value Bv2.

Then, in step 110, the output value Bv1 of the first fuzzy operation calculated in the previous step 107.
And the output value Bv2 of the second fuzzy operation calculated in step 109 are compared, the larger value is determined as the final control voltage value Bv, and the capacitor fan 2 is driven by the voltage Bv.

After that, other control is performed in step 111, and the process returns to the first step.

As described above, the condenser fan voltage is determined according to the compressor capacity, the water temperature, and the vehicle speed, so that the fan can be driven under optimal conditions with no waste and the operation of the cooling cycle can be stabilized. it can.

[0038]

As described above, according to the air conditioner of the present invention, the rotation speed of the condenser fan is controlled by using the compressor capacity, the vehicle speed, and the engine cooling water temperature as input factors, so that there is no waste of electric power. Under such conditions, the condenser fan can be operated finely while maintaining the stability of the cooling cycle. Moreover, although there are multiple input factors, optimum control can be performed by simply creating a simple fuzzy rule.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of the present invention.

FIG. 2 is a schematic diagram showing the configuration of an embodiment of the present invention.

FIG. 3 is a flowchart showing the control contents of the same embodiment.

FIG. 4 is a table showing a first fuzzy rule used for fuzzy calculation in the same control.

FIG. 5 shows a membership function used in the first fuzzy calculation, where (a) is a membership function of the compressor capacity control value Isol which is a parameter of the antecedent part, and (b) is a membership function.
Is a membership function of the vehicle speed V that is a parameter of the antecedent part, and (c) is a membership function of the capacitor fan voltage Bv that is a parameter of the antecedent part.

FIG. 6 is a table showing a second fuzzy rule used for the fuzzy calculation.

FIG. 7 shows a membership function used in the second fuzzy operation, where (a) is the water temperature Tw which is the antecedent parameter.
Is a membership function of the vehicle speed V that is a parameter of the antecedent part, and (c) is a membership function of the capacitor fan voltage Bv that is a parameter of the antecedent part.

[Explanation of symbols]

 1 radiator 2 cooling fan (condenser fan) 3 compressor capacity detecting means 10 air conditioning duct 13 evaporator 16 variable capacity compressor 16A solenoid valve (capacity controlling means) 17 condenser 50 control unit 57 water temperature sensor (engine cooling water temperature detecting means) 58 vehicle speed sensor

Claims (1)

[Claims] 1. A condenser for condensing a refrigerant, which is arranged in the vicinity of a radiator for cooling engine cooling water and cooled by a cooling fan together with traveling wind, a variable capacity compressor driven by an engine, and an air conditioning duct. In a vehicle air conditioner that forms a cooling cycle by connecting a pipe to an evaporator, a means for detecting the temperature of the cooling water of the engine, a means for detecting the traveling vehicle speed of the vehicle, and a capacity for the variable capacity compressor are detected. Means for fuzzy inferring the rotational speed of the condenser cooling fan based on the cooling water temperature, traveling vehicle speed, compressor capacity, and predetermined control rule from these detecting means, and the condenser so that the inferred rotational speed is achieved. A fan control means for driving and controlling the cooling fan; Adjusting unit.