JPH05278433A - Air conditioner for vehicle - Google Patents

Abstract

PURPOSE:To secure a comfortable head cool and foot warm condition in an air conditioner which has a cool air bypass passage. CONSTITUTION:An object blowoff temperature is calculated depending on the signal of a car room temperature sensor and the like (step 102), and an air mix door object opening is calculated depending on the above result (step 103). Then, a correcting amount DELTAthetam of the air mix door object opening is fuzzy- calculated depending on several elements such as an evaporator blowoff temperature Te, a cool air bypass door opening thetab, and the air mix door object opening thetam (step 104 to 106). And the air mix door object opening is corrected depending on the above resultant value (step 107), and the air mix door is driven and controlled to make into the corrected opening (step 108).

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 cold air bypass passage for guiding cold air immediately after passing through an air mix door to a vent outlet.

[0002]

2. Description of the Related Art In a general vehicle air conditioner (automatic air conditioner), an in-vehicle temperature sensor for detecting a representative temperature in the vehicle is arranged at an appropriate place in the vehicle, and an in-vehicle temperature Tr detected by the sensor and an outside air temperature sensor The outside air temperature Ta detected by the solar radiation sensor, the solar radiation amount Qsun detected by the solar radiation sensor,
The target outlet temperature Xm is calculated using the set temperature Tset set by the temperature setter, and the opening temperature of the air mix door is controlled based on the calculated result to adjust the outlet temperature into the vehicle.

By the way, recently, an air conditioner having a cold air bypass passage for introducing the cool air immediately after passing through the evaporator to the vent outlet has appeared. For example, Jikkou Sho 59-34
No. 497 and No. 60-151710,
In order to cool only the temperature of the occupant's head more than usual when the sunlight is strong, a device has been proposed in which the cool air immediately after the evaporator is directly guided to the vent outlet through a cool air bypass passage provided separately from the main duct. There is. Usually, in an air conditioner having a cold air bypass passage of this kind, one end of the bypass passage is communicated immediately after the evaporator, the other end is communicated with the vent outlet, and a door is provided at the bypass passage inlet,
By adjusting the opening of this door, the temperature of air blown out from the vent outlet is changed auxiliary.

[0004]

However, in the air conditioner having the cold air bypass passage as described above, when the cold air bypass door is actually opened, the blowout temperature near the head of the occupant is lowered, and the effect thereof is reduced. As a result, the temperature detected by the in-vehicle temperature sensor decreases, which causes the air-mix door to be controlled to the heat side and raises the foot temperature, and the head cold foot heat state is emphasized more than expected and the comfort is impaired.

In view of the above circumstances, it is an object of the present invention to provide an air conditioning system for a vehicle which can realize a comfortable head cold foot heat condition.

[0006]

In order to solve the above problems, the present invention provides a ventilation duct 10 having a foot outlet 23 and a vent outlet 22 at a downstream end, as shown in FIG.
An evaporator 13 arranged in the ventilation duct 10, a heater core 15 arranged downstream of the evaporator 13,
The air flow after passing through the evaporator is divided into a flow passing through the heater core 15 and a flow bypassing the heater core 15,
Thereby, the air mix door 14 for adjusting the mixing ratio of the warm air passing through the heater core 15 and the cold air bypassing the heater core 15 to adjust the temperature of the air blown into the vehicle, and immediately after passing through the evaporator before being mixed with the warm air. Cold air bypass passage 40 for guiding the cold air to the vent outlet 22, and a cold air bypass door 41 for opening and closing the cold air bypass passage 40.
A cold air bypass door drive control means 1 for controlling the opening degree θb of the cold air bypass door 41, a vehicle interior temperature sensor 51 for detecting a representative temperature in the vehicle, and a target in relation to at least a detection value of the vehicle interior temperature sensor 51. A target outlet temperature calculating means 2 for calculating an outlet temperature, an air mix door target opening calculating means 3 for calculating a target opening θm of the air mix door 14 based on an output of the target outlet temperature calculating means 2, and the air In a vehicle air conditioner having an air mix door drive control unit 4 that adjusts the opening of the air mix door 14 so as to converge to the mix door target opening θm, the temperature Te of the air immediately after passing through the evaporator 13 Evaporator outlet temperature detecting means (duct sensor) 56 for detecting
And the air temperature Te immediately after passing through the evaporator detected by the means 56, and the air mix door target opening calculation means 3
The fuzzy calculation of the correction amount Δθm of the air mix door target opening θm based on the calculated air mix door target opening θm and the cold air bypass door 41 opening θb. The outputs of the means 5 and the air mix door target opening calculation means 3 are corrected by the output of the air mix door target opening correction amount calculation means 5,
Air mix door target opening correction means 6 for inputting the corrected air mix door target opening θm to the air mix door drive control means 4 is provided.

[0007]

In the air conditioner of the present invention, the air mix door target opening correction amount calculating means 5 calculates the air temperature Te immediately after passing through the evaporator, the air mix door target opening θm, and the cold air bypass door 41 opening θb. , A fuzzy calculation of the correction amount Δθm of the target opening θm of the air mix door.
That is, in this case, the antecedent parameter (input) of the fuzzy operation is Te, θm, and θb, and the antecedent parameter (output) is Δθm.

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. First, according to each fuzzy rule, the grade of the variable Te in the antecedent part (also called the degree of belonging to the fuzzy label, the goodness of fit, or the membership value) is obtained from the given input side membership function, and then another The grade of the variable θm is obtained, and the grade of another variable θb is obtained, and the minimum value of all grades is taken. This processing is called antecedent processing. Next, as a consequent process, the output-side membership function is truncated at the grade (that is, a limit is added), and the trapezoidal output obtained by the trimming is ORed. Next, the center of gravity of the trapezoidal portions that are logically summed and superposed is obtained, and the position of the center of gravity is set as the inference result, that is, the final output air mix door target opening correction amount Δθm. This inference method is disclosed, for example, in Japanese Patent Laid-Open No.
This is a known method in Japanese Patent Publication No. 92763. As the inference method, another method may be adopted separately.

Then, the correction amount Δθ deduced as described above
The target opening θm of the air mix door is corrected by m, and the air mix door 14 is controlled so as to reach the corrected target opening.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 2 is a diagram showing a specific configuration of the air conditioner of the embodiment. In this air conditioner, the inside air inlet 10A and the outside air inlet 10B are formed in the most upstream part of the main duct (ventilation duct) 10, and the inside air to be introduced into the main duct 10 is controlled by controlling the opening and closing of the intake door 11. The proportion of outside air can be adjusted.

The main duct 10 is provided with a blower fan 12, an evaporator 13, an air mix door 14 and a heater core 15 in that order toward 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 refrigeration cycle. The compressor 16 is driven by the force transmitted from the engine, and its drive is controlled by connecting and disconnecting the electromagnetic clutch.

The air mix door 14 is
The ratio of the air passing through the heater core 15 and the air not passing through the heater core 15 is adjusted. And heater core 1
The air that has passed through 5 and the air that has not passed through 5 are mixed on the downstream side of the heater 15 to have their temperatures adjusted, and are blown into the vehicle through the air outlet.

The rear end of the main duct 10 has a defrost outlet 21 for blowing air toward the inner surface of the windshield.
And a vent (VENT) outlet 22 that blows air toward the occupant's head and a foot (FOOT) outlet 23 that blows air toward the feet of the occupant. Mode doors 24, 25, and 26 are provided at the outlets 21, 22, and 23, respectively. The blowing mode can be changed by selectively opening and closing the mode doors 24, 25, and 26.

The vent outlet 22 is further divided into left and right vent outlets 22R and 22L. Then, by opening and closing the air distribution door 27, it is possible to adjust the air distribution balance from the left and right vent outlets 22R and 22L.

In addition to the main duct 10, this air conditioner is provided with a cold air bypass duct (cold air bypass passage) 40 that bypasses a part of the main duct 10. One end of the cold air bypass duct 40 is the main duct 1
0 is connected to a position downstream of the evaporator 13 and upstream of the air mix door 14, and the other end is connected to a position before the air distribution door 27 of the vent outlet 22. Then, a part of the cold air that has passed through the evaporator 13 can be directly guided to the vent outlet 22. A cold air bypass door 41 is provided at the tip opening of the cold air bypass duct 40, and the vent outlet 22 is adjusted by adjusting the opening of the door 41.
You can adjust the amount of cold air to bypass.

The intake door 11, the air mix door 14, the mode doors 24 to 26, the air distribution door 27, and the cold air bypass door 41 described above are respectively provided with an actuator 30 and an actuator 30, respectively.
Opening / closing control is performed by 31, 32, 33, and 34. The actuators 30, 31, 32, 33, 34, the blower fan 12, and the compressor 16 are controlled by the control unit 50.

The control unit 50 includes a drive circuit for driving the actuator and the blower fan, a microcomputer for supplying a control signal to each drive circuit, an A / D converter connected to the microcomputer, and a multiplexer. It includes.

A in the control unit 50
The / D converter includes an in-vehicle temperature sensor 51 that detects a representative temperature in the vehicle interior and an outside air temperature sensor 52 that detects an outside air temperature.
And a solar radiation sensor 53 for detecting the amount of solar radiation entering the vehicle interior,
Temperature setter 5 for setting the representative temperature (average temperature) in the passenger compartment
4, a potentiometer 55 that detects the opening degree of the air mix door 14, a duct sensor 56 that detects the temperature of the air blown out of the evaporator 13, and a head temperature setting device 57 that sets the temperature around the head of the occupant. , Are connected.

In this embodiment, when the opening θm of the air mix door 14 is "0%" (the position shown by the solid line in FIG. 2), it is full cool, and when it is "100%" (FIG. 2). The position indicated by the chain double-dashed line) is full hot. Further, regarding the opening degree θb of the cold air bypass door 41, “0%” is fully closed and “100%” is fully open.

Next, the contents of the air conditioning control performed by the control unit 50 will be described with reference to the flowchart of FIG. In this embodiment, the microcomputer of the control unit performs arithmetic processing according to a predetermined program to cooperate with each actuator, drive circuit, etc., to realize each function realizing means shown in FIG. Cold air bypass door drive control means 1, target outlet temperature calculation means 2, air mix door target opening calculation means 3, air mix door target opening correction amount calculation means 5, air mix door target opening correction means 6, air mix door The drive control means 4 etc. are achieved. The main functions of these will be clarified by the following explanation.

When the control routine shown in FIG. 3 starts, first, in step 101, detection signals of various sensors are input. Next, at step 102, the vehicle interior temperature Tr detected by the vehicle interior temperature sensor 1, the outside air temperature Ta detected by the outside air temperature sensor 2, and the set temperature Tse by the temperature setter 3.
Based on t and the amount of solar radiation Qsun detected by the solar radiation sensor 4, the target outlet temperature Xm is calculated by the following equation: Xm = A.Tset-B.Tr-C.Ta-D.Qsun + E. However, A to D are constants, and E is a correction term.

Next, the routine proceeds to step 103, where the target opening θm of the air mix door 14 is calculated based on the calculated target outlet temperature Xm, and at step 104 the air mix door 14 is driven and controlled based on the calculated value. To do. Then
Steps 104 to 10 for fuzzy calculation of the correction amount Δθm (the cool side is positive) of the target opening of the air mix door
Proceed to 6.

In this fuzzy operation, the following six fuzzy rules (these are determined by experience or experimental results obtained in advance) are shown below.
Membership functions for each parameter shown in FIG. 4 are given. (1) When Te is low, θb is large, and θm is large, Δθ
Make m small. (2) When Te is low, θb is large, and θm is small, Δθ
Make m large. (3) When Te is low, θb is small, and θm is large, Δθ
Make m small. (4) When Te is low, θb is small, and θm is small, Δθ
Set m in. (5) When Te is high, θb is large, and θm is large, Δθ
Make m small. (6) When Te is high, θb is large, and θm is small, Δθ
Set m in.

Here, the function of FIG. 4A is a membership function of the evaporator outlet temperature Te, which is an input variable,
The function of (b) is the input variable cold air bypass door opening θ
The membership function of b, the function of (c) is the input variable air mix door target opening θm membership function,
The function (d) is a membership function of the air mix door target opening correction amount Δθm which is an output variable. And
Fuzzy inference operations are performed based on these fuzzy rules and membership functions.

In the first step 104 of the fuzzy calculation, the antecedent variables are the evaporator outlet temperature Te, the cold air bypass door opening θb, and the evaporator target opening θm, and each parameter T is set for each of the preset fuzzy rules.
Obtain the grade Wi of e, θb, and θm. Next, at step 105, the correction amount Δθm of the air mix door target opening degree is calculated for each grade of each rule from the output side membership function.
i is calculated, the center of gravity is calculated in step 106, and the position of the center of gravity is inferred.
θm.

Here, a calculation will be made for one specific example. Here, the air mix door target opening correction amount Δθm is calculated when the evaporator outlet temperature Te is 3 ° C., the cold air bypass door opening θb is 100%, and the air mix door target opening θm is 45%.

The rules applicable at this time are (1) and (2). First, the goodness of fit for each rule is obtained and the minimum value is calculated. (1) ... A = 1, B = 1, C = 0.5 → 0.5 (2) ... A = 1, B = 1, C = 0.5 → 0.5

Next, when the barycentric position is calculated, Δθm = (5 × 0.5 + 15 × 0.5) / (0.5 + 0.5) = 10%.

This value is the amount by which the evaporator target opening is corrected to the cool side. That is, in the case of this specific example, it is inferred that the evaporator target opening previously obtained should be corrected to the cool side by 10%.

Then, step 107 after the fuzzy calculation.
Then, a new corrected air mix door target opening θm is obtained by subtracting the calculated correction amount Δθm from the target opening θm. Next, the opening of the air mix door is controlled so as to reach the target opening θm after the correction (step 108), and then other control is performed (step 10).
9) Return to the first step.

In this way, the air mix door opening is corrected in relation to the evaporator outlet temperature Te, the cold air bypass door opening θb, and the air mix door target opening θm.
More appropriate air mix door control than before is possible.
Also, because this operation is performed based on the fuzzy rules,
This can be realized without requiring complicated control logic, and can provide a comfortable head cold foot thermal environment to the occupant.

[0032]

As described above, according to the vehicle air conditioner of the present invention, the air mix door target opening is corrected based on the evaporator blowout temperature, the cold air bypass door opening, and the air mix door target opening. As a result, more appropriate air mix door control can be performed than in the past, and a comfortable feeling of head cold foot heat can be secured.

[Brief description of drawings]

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

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

FIG. 3 is a flowchart showing a control operation of the embodiment.

FIG. 4 shows a membership function used for fuzzy calculation in the above control, where (a) is a membership function of the evaporator outlet temperature Te, which is the antecedent variable, and (b) is cold air, which is the antecedent variable. Membership function of bypass door opening θb, (c) membership function of air mix door target opening θm which is an antecedent part variable, (d) air mix door target opening correction amount which is a consequent part variable It is a membership function of Δθm.

[Explanation of symbols]

 1 Cold Air Bypass Door Drive Control Means 2 Target Blowout Temperature Calculation Means 3 Air Mix Door Target Opening Calculation Means 4 Air Mix Door Drive Control Means 5 Air Mix Door Target Opening Correction Amount Calculation Means 6 Air Mix Door Target Opening Correction Means 10 Ventilation duct 13 Evaporator 14 Air mix door 15 Heater core 22 Vent outlet 23 Foot outlet 40 Cold air bypass passage (Duct) 41 Cold air bypass door 50 Control unit 56 Evaporator temperature detector (duct sensor)

Claims (1)

[Claims] 1. A ventilation duct having a foot outlet and a vent outlet at a downstream end, an evaporator arranged in the ventilation duct, a heater core arranged downstream of the evaporator, and an air flow after passing through the evaporator. An air mix door that divides the flow passing through the heater core and the flow bypassing the heater core, thereby adjusting the mixing ratio of the warm air passing through the heater core and the cold air bypassing the heater core to adjust the temperature of the air blown into the vehicle. A cold air bypass passage that guides the cold air immediately after passing through the evaporator before being mixed with the warm air to the vent outlet, a cold air bypass door that opens and closes the cold air bypass passage, and a cold air bypass that controls the opening degree of the cold air bypass door. A door drive control means, an in-vehicle temperature sensor for detecting a representative temperature in the vehicle, and at least the in-vehicle temperature sensor. A target outlet temperature calculating means for calculating a target outlet temperature in relation to the outlet value; an air mix door target opening calculating means for calculating a target opening of the air mix door based on the output of the target outlet temperature calculating means; An air conditioner for a vehicle, comprising: an air mix door drive control means for adjusting an air mix door opening degree so as to converge to the air mix door target opening degree; and detecting a temperature of air immediately after passing through an evaporator. An evaporator outlet temperature detecting means, an air temperature immediately after passing through the evaporator detected by the means,
Air mix door target opening that performs a fuzzy calculation of the correction amount of the air mix door target opening based on the air mix door target opening calculated by the air mix door target opening calculation means and the cold air bypass door opening. Output of the air mix door target opening calculation means is corrected by the output of the air mix door target opening correction quantity calculation means, and a signal corresponding to the corrected air mix door target opening is output to the air. An air conditioner for a vehicle, comprising: an air mix door target opening correction means for inputting to the mix door drive control means.