JPH0342323A - Air conditioner for vehicle - Google Patents

Abstract

PURPOSE:To always correct solar radiation appropriately in spite of altitude of the sun by detecting respective thermal loads due to solar radiation on the horizontal face and the vertical face of vehicle, and computing a correcting quantity for solar radiation corresponding to the overall thermal load due to solar radiation computed based on respective thermal loads. CONSTITUTION:An overall signal corresponding to the thermal load in a vehicle room based on a plurality of environmental conditions is computed by a means 100 and operation of an air conditioner to adjust the thermal load in the vehicle room is controlled by a means 110 according to the overall signal. In such air conditioner, respective thermal loads due to solar radiation on the horizontal face and the vertical face of the vehicle are detected by respective means 120, 130. Based on the detected thermal loads, an overall thermal load due to solar radiation is computed by a means 140. A correcting quantity for solar radiation according to the computed overall thermal load is computed by a means 150. Hereby, correction of solar radiation as appropriate air conditioner function is always performed in spite of variation of the sun attitude.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a vehicle air conditioner, and particularly to one that performs air conditioning control while correcting solar radiation.

(Prior art) Conventionally, as this type of device, for example, Japanese Patent Publication No. 58-19
As shown in Publication No. 484, a solar radiation detection means using a photodiode is provided, and a delay means for delaying the rate of change of the output signal of the solar radiation detection means is provided to perform drive control of air conditioning equipment taking into account the amount of solar radiation. In addition, there is a known system in which the control state of each air conditioner is changed at a speed that does not impair the feeling of air conditioning for the occupants in response to changes in solar radiation.

(Problems to be Solved by the Invention) However, in the above conventional example, since the photoresponsive elements such as photodiodes constituting the solar radiation detection means have directional light detection characteristics, it is difficult to detect the actual amount of solar radiation. Even if there is no change in
Even though solar radiation is actually shining into the vehicle interior, the detection result is as if the solar radiation has decreased, and for this reason, the air conditioner changes the driving state of air conditioning equipment such as blowers according to the detected amount of solar radiation. The device has a problem in that the required amount of airflow cannot be obtained, that is, the solar radiation correction is insufficient.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art due to the light-receiving characteristics of photodiodes, and particularly provides a vehicle air conditioner that can perform appropriate solar radiation correction even when the solar altitude changes. This is the issue.

(Means for Solving the Problems) As shown in FIG. 1, the vehicle air conditioner according to the present invention calculates the heat load in the vehicle interior based on a plurality of environmental conditions that affect the heat load in the vehicle interior. a total signal calculation means 100 for calculating a total signal corresponding to , and the total signal calculation means 1
Horizontal surface heat load detection for detecting the heat load due to solar radiation on the horizontal surface of the vehicle in a vehicle air conditioner comprising a control means 110 for controlling the operation of an air conditioner that adjusts the heat load in the vehicle interior according to the calculation result of 00. means 120, vertical surface heat load detection means 130 for detecting heat load due to solar radiation on the vertical surface of the vehicle, and said horizontal surface heat load detection means 12.
0 and the output signal of the vertical surface heat load detection means 130; A solar radiation correction amount calculating means 150 is provided for calculating a solar radiation correction amount to be input to the comprehensive signal calculating means 100 based on the solar radiation correction amount calculating means 100.

(Function) Therefore, whereas conventionally only the amount of solar radiation on either the horizontal or vertical surfaces of the vehicle was considered, the horizontal surface heat load detection means and the vertical surface heat load detection means can be used to detect the solar radiation on either the horizontal or vertical surfaces of the vehicle. Since both amounts of solar radiation are taken into consideration in controlling the air conditioner, the above problem can be achieved.

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

In FIG. 2, the vehicle air conditioner has an air conditioning duct 1
An intake door switching device 2 is provided on the most upstream side of the intake door switching device 2, and an inside/outside air switching door 5 is disposed at the part where the inside air population 3 and the outside air population 4 are separated. By operating the actuator 6, the air introduced into the air conditioning duct 1 can be selected between inside air and outside air.

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

The evaporator 8 is connected to a compressor (not shown) through piping to form a cooling cycle. Further, the heater core 9 is configured to circulate cooling water of an engine (not shown) to heat the air.

An air mix door 10 is provided in front of the heater core 9, and by adjusting the opening degree of the air mix door IO using an actuator 11, the air passing through the heater core 9 and the air bypassing the heater core 9 can be separated. The proportions are now adjusted. Further, on the downstream side of the heater core 9, a defrost outlet 12 and a vent outlet 13 are provided.
The mode doors 15a, 15b are provided at the separated portions, and the mode doors 15a, 15b are operated by an actuator 16.1.
The blowout mode can be switched by operating 7.

The actuators 6.11, 16.17 and the motor 7a of the blower 7 are connected to drive circuits 402 to 4, respectively.
It is controlled based on the output signal from the microcomputer 41 via 0d. This microcomputer 41
are a central processing unit (CPU), a read-only memory (RCli), and a random access memory (RA) (not shown).
M), an input/output board (■/○), etc., are well-known in themselves, and the microcomputer 41 receives the vehicle interior temperature T from the vehicle interior temperature sensor 42 that detects the temperature inside the vehicle.
II, outside air temperature TA from the outside air temperature sensor 43 that detects the outside air temperature, detection current IA from each of the first and second sensors 44a, 44b that constitute the solar radiation altitude sensor 44, 1
．． , the set temperature TD from the temperature setter 45 that sets the temperature inside the vehicle is transmitted to the multiplexer 46 and the A/D converter 47.
It is converted into a digital signal and input via the .

Further, an output signal is inputted to the microcomputer 41 from the operation section 48 . This operation unit 48 is used to switch between automatic control states (AUTO) as the control state of the air conditioner.
UTO switch, inside/outside air switching door (INTAKE D
It has a changeover switch for OOR) 5, a switch for manually setting the speed of the blower 7, etc. (not shown).

Here, as shown in FIGS. 3 and 4, the solar radiation altitude sensor 44 is installed at an appropriate position on the upper surface 49a of the instrument panel of the vehicle 49, and is connected to a first sensor 44a using a known photodiode. As shown in FIG. 4, the second sensor 44b and the second sensor 44b are attached to the base 50 so as to be perpendicular to each other. The light receiving surface of the second sensor 44b faces the direction of travel of the vehicle. In addition, in FIG. 3, the indicated 0090°,
The value of 90° represents the angle of incidence of sunlight on the horizontal plane.

FIG. 5 shows a main flowchart showing an example of the control of the entire apparatus by the above-mentioned microcomputer 41, and the overall control operation of the apparatus will be described below with reference to the same figure.

First, the microcomputer 41 starts execution at step 200, proceeds to step 202, and initializes various variables, flags, etc.

In the next step 204, the above-mentioned vehicle interior temperature sensor 42
Detection signals and the like are inputted from etc., and the process proceeds to step 206.

In step 206, based on the input signal from the solar radiation altitude sensor 44, solar radiation correction calculations necessary to obtain a solar radiation correction signal T used for calculating a total signal T, which will be described later, are performed. Note that the specific details of this solar radiation correction calculation will be described later.

After step 206, the process proceeds to step 300, where the total signal T is calculated. This comprehensive signal is a signal corresponding to the heat load in the vehicle interior, and is calculated based on the vehicle interior temperature sensor 42 and the like inputted in step 204 described above, for example, by the following equation (1).

T= KITR+KzTA+ K3TS K4TD+
C... (11 However, 4 in K1- is an arithmetic number, and C is an arithmetic constant.

After calculating the overall signal, the process proceeds to step 400, where the rotation speed of the blower 7, the opening degree of the air mix door 10, the blowout mode, etc. are controlled according to the magnitude of the overall signal, and the process returns to step 204 again, where the series of steps described above are performed. The process will be reversed.

FIG. 6 shows the above-mentioned solar radiation correction calculation as a subroutine flowchart, and the contents thereof will be explained below with reference to the same figure.

The microcomputer 41 starts execution at step 206, proceeds to step 208, and calculates the incident angle θ of sunlight. That is, the first and second sensors 44a of the solar radiation altitude sensor 44 described above.

If each detected current value of 44b is set to IA+Im, θ can be obtained by equation (2) shown below.

■^ θ= jan pull... (2)! Equation (2) in this book is derived as follows.

First, as shown in FIG. 7, the solar radiation amount (hereinafter referred to as "direct solar radiation amount") @a of the sunlight itself (indicated by the dotted line in the figure) that enters the solar radiation altitude sensor 44.

Then, the detected current values lA and In of the first and second sensors 44a and 44b are generally expressed as in the following equations.

I A = KaQ3 stnθ ・(3+1++
= to, Qs 5in(90-θ) = to, Q, cOsθ
-(4) The above equations (3) and (4) are expressed as shown below for Q.

Q, = I A/, sinθ ・(5) Qs
= I B/K, cosθ ・(6) Furthermore,
Since the above equation (5) = equation (6), r, /, sin θ = 1. /, cos θ ・(7).

Therefore, from tanθ= I A/[s, (2)
Formula % Formula % Next, in step 210, the amount of direct solar radiation Q is calculated. This calculation is performed based on equation (3) or (4) 2 shown in the explanation of the process of deriving the calculation formula in step 208, and after the calculation is completed, the process proceeds to step 212.

In step 212, the above-mentioned direct solar radiation ff1Q
Of s, the horizontal surface heat load QT corresponding to the amount of solar radiation vertically incident on the first sensor 44a is calculated by the following formula.

Qt = Qs Sinθ ・(8) As can be seen from the above equation, this horizontal surface heat load QT takes the maximum value when the incident angle θ is 90 degrees, and Figure 8 shows the change in Q with respect to the incident angle. Shown as a characteristic curve. This step 212
After processing, the process advances to step 214.

In step 214, the vertical surface heat load QF corresponding to the amount of solar radiation perpendicularly incident on the second sensor 44b, out of the amount of direct solar radiation Q, is calculated using the following formula.

QF = Q, cosθ/Kb ・(9) Here,
K is a calculation coefficient.

In other words, Q calculated in step 214 can be interpreted as the amount of solar radiation directly hitting the occupant's body.

Incidentally, FIG. 9 shows the change in the thermal load Q with respect to the incident angle θ, and the maximum value is obtained when the incident angle is 0 degrees.

After the processing in step 214, the process proceeds to step 216, where the sum of the above-mentioned Q and Q is set as the total heat load Q S u fi, and the process proceeds to step 218.

In step 218, based on the conversion characteristics between the predetermined total heat load Q□7 and the solar radiation correction amount T,
Calculate the solar radiation correction amount T corresponding to Q gun determined in step 216 above, and return to the main routine via step 77'' 220.

To summarize the operation of the above configuration, for example, when the angle of incidence of sunlight is at a relatively low altitude, the solar radiation detection means corresponding to the first sensor 44a is In this case, the heat load QT detected by the sensor 44a will be small, and if the air conditioning equipment is controlled based only on this in consideration of solar radiation correction, the blower 7, etc. will be adjusted in response to the small heat load QT. The increase in air volume, etc. will not be significant.

However, in this device, since the amount of solar radiation incident on the second sensor 44b is taken into consideration (see step 216),
Increasing the air volume of the blower 7, etc., will backfire compared to the conventional device.

(Effects of the Invention) Since the present invention is configured as described above, even if the sunlight intensity changes, there will be no shortage of solar radiation correction due to the light receiving characteristics of the photodiode, and it will always be possible to maintain appropriate solar radiation. This has the effect that correction is performed and comfortable air conditioning control can be performed.

[Brief explanation of drawings]

FIG. 1 is a functional block diagram of a vehicle air conditioner according to the present invention, FIG. 2 is a block diagram showing a specific configuration of the same vehicle air conditioner, and FIG. 3 is a solar radiation altitude sensor used in this device. Figure 4 is an enlarged perspective view of the solar radiation altitude sensor, Figure 5 is a main flowchart showing an example of control of this device by the microcomputer used in this device, and Figure 6 is the solar radiation altitude sensor controlled by the microcomputer. Subroutine flowchart showing control of correction calculation, seventh
The figure is a side view of the solar altitude sensor showing the incident state of solar radiation on the solar altitude sensor, Figure 8 is a characteristic diagram showing the relationship between the incident angle and horizontal heat load, and Figure 9 is the incident angle and vertical heat load. FIG. 41... Microcomputer, 44... Solar radiation altitude sensor, 44a... First sensor, 44b... Second
sensor, 100... comprehensive signal calculation means, 110...
- Control means, 120... - Horizontal surface heat load configuration means, 13
0... Vertical surface heat load detection means, 140 comprehensive solar radiation load calculation means, 1 0... Solar radiation correction position calculation means. Patent applicant Diesel Equipment Co., Ltd.

Claims (1)

[Scope of Claims] Comprehensive signal calculation means for calculating a comprehensive signal corresponding to the heat load in the vehicle interior based on a plurality of environmental conditions that affect the heat load in the vehicle interior; A vehicle air conditioner comprising: a control means for controlling the operation of an air conditioner that adjusts the heat load in the vehicle interior according to the vehicle interior; vertical surface heat load detection means for detecting the heat load due to solar radiation; and a synthesis device for calculating the overall heat load due to solar radiation based on the output signal of the horizontal surface heat load detection means and the output signal of the vertical surface heat load detection means. A solar radiation heat load calculation means, and a solar radiation correction amount calculation means for calculating a solar radiation correction amount to be input to the comprehensive signal calculation means based on the calculation result of the comprehensive solar radiation heat load calculation means. Air conditioner.