JP2767324B2 - Vehicle air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner for a vehicle which can prevent a driver from falling asleep when the vehicle is running.

[0002]

2. Description of the Related Art In addition to a monotonous driving environment in which an air conditioner for a vehicle is operated and operated for a long time at an appropriate temperature, when a driver is tired of driving for a long time, the driver easily falls asleep. Condition, which is one of the major causes of accidents. In order to solve such a problem, for example, Japanese Utility Model Laid-Open Publication No. 63-43841 discloses a state in which the driver's arousal level is reduced when the vehicle is running. Using an air conditioner has been disclosed.

[0003]

However, this conventional apparatus has a problem that the irritating odor emitted to increase the driver's arousal level also gives the driver discomfort. . SUMMARY OF THE INVENTION An object of the present invention is to provide a vehicle air conditioner that can solve the above-mentioned problems in the conventional art and can prevent the occurrence of dozing driving without giving a driver discomfort. It is to provide a device.

[0004]

A feature of the present invention to achieve the above object is to detect the concentration of oxygen or carbon dioxide in a vehicle cabin and check whether these concentrations promote the driver's drowsiness. If it is determined whether or not the concentration of oxygen or carbon dioxide promotes the driver to fall asleep, the set temperature of the air conditioner is reduced.
The amount by which the set temperature decreases may be determined by the value of the detected concentration. Further, the set temperature may be continuously lowered until the concentration state that promotes the driver's drowsiness is resolved, or may be intermittently lowered at appropriate time intervals.

[0005]

[Action] The oxygen concentration in the passenger compartment decreases due to the occupant's breathing,
Conversely, the carbon dioxide concentration increases. Such in-vehicle environmental conditions, such as a lack of oxygen and an increase in carbon dioxide, result in the driver's drowsiness. When it is detected that the vehicle interior is in a state that encourages the driver to fall asleep due to a decrease in oxygen concentration or an increase in carbon dioxide concentration,
The set temperature of the air-conditioning apparatus is lowered, and the temperature in the vehicle compartment is lower than before, thereby promoting awakening of the driver and recovery of attention.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a block diagram showing a control system of an embodiment of a vehicle air conditioner according to the present invention. The vehicle air conditioner 1 is a device for taking in air outside and inside the vehicle compartment to control the temperature, and supplying air at a temperature necessary to keep the interior of the vehicle compartment at a desired temperature. And a control unit 3.

The main body 2 has a known structure in which a blower, a heater core, an evaporator, and the like are disposed in a ventilation duct. In FIG. Only the air mix door 4 and the motor 5 for positioning the air mix door are shown, and other elements are not shown.

In FIG. 1, reference numeral 6 denotes a room temperature sensor which outputs a room temperature signal A indicating the temperature in the vehicle interior, 7 denotes an outside air temperature sensor which outputs an outside air temperature signal B indicating the temperature outside the vehicle, and 8 denotes an amount of solar radiation indicating the amount of solar radiation It is a solar radiation sensor that outputs a signal C, and a room temperature signal A, an outside air temperature signal B, and a solar radiation signal C are input to the control unit 3.

Reference numeral 9 denotes a setting device for setting a desired target temperature in the vehicle interior. The setting device 9 outputs a set temperature signal D indicating the set temperature set at that time. It is input to the set value changing unit 10. The set value changing unit 10 is a means for changing the set temperature set by the setting unit 9 based on the current oxygen concentration state in the vehicle interior, as will be described later.
An output signal E from 0 is input to the control unit 3.

The control unit 3 outputs these signals A, B,
In response to C and E, the air temperature required to maintain the temperature indicated by the output signal E in the passenger compartment is calculated, and the air mixing door 4 is moved to a position necessary to obtain the required air temperature. A control signal S for positioning is output. The control signal S is input to a driving unit 11 for driving the motor 5, and the motor 5 for positioning the air mixing door 4 is driven by a driving signal Y from the driving unit 11. The opening is adjusted.

In order to change the set temperature set by the setter 9 based on the state of the oxygen concentration in the passenger compartment, the vehicle air conditioner 1 includes an oxygen concentration sensor 12 for detecting the oxygen concentration in the passenger compartment. An oxygen concentration for determining whether or not the oxygen concentration in the vehicle compartment is lower than a predetermined concentration value M in response to an oxygen concentration signal F indicating the oxygen concentration in the vehicle compartment output from the oxygen concentration sensor 12. And a determination unit 13. Here, the predetermined concentration value M can be set to an appropriate value suitable for the purpose by experiments or the like in consideration of the degree of driver's drowsyness caused by the decrease in the oxygen concentration.

The oxygen concentration discriminating section 13 constructed as described above
Outputs a concentration decrease signal L when the vehicle interior oxygen concentration indicated by the oxygen concentration signal F becomes smaller than a predetermined value M, and the concentration decrease signal L is used as a signal for changing the set value. Is input to

FIG. 2 is a detailed block diagram of the set value changing unit 10. The set value changing unit 10 converts the set temperature signal D into a digital signal for converting the set temperature signal D into a digital format.
An analog converter (A / D) 101 is provided.
Has been entered.

The set value changing unit 10 further includes first and second fixed data generating units 103 and 104, from which fixed data X1 and X2 are output, respectively. One of the fixed data is applied to the subtraction unit 102 as the subtraction data X by the changeover switch 105 that is controlled in response to the decrease signal L.

In the illustrated embodiment, the content of the first fixed data X1 is zero, and the content of the second fixed data X2 is 10 degrees C.
It has become. When the density reduction signal L is not output, the changeover switch 105 is in the switching state shown by the solid line, and the first fixed data X1 is
When the density reduction signal L is output, the changeover switch 105 enters the switching state indicated by the dotted line, and the second fixed data X2 is input to the subtraction unit 102 as the subtraction data X. .

In the subtracting section 102, DD-X is calculated, and a signal indicating the calculation result is obtained as an output signal E. Therefore, if the oxygen concentration is equal to or higher than the predetermined value M,
The content of the output signal E is DD-X1, and the content of the output signal E is the same as the content of the set temperature signal D. On the other hand, when the oxygen concentration becomes smaller than M, the content of the output signal E becomes DD-X
2, which is 1 from the set temperature set by the setter 9.
A temperature lower by 0 ° C. is given to the control unit 3 as a target set temperature value.

Therefore, according to this configuration, when the oxygen concentration is higher than the predetermined value M, the temperature in the vehicle compartment is controlled according to the temperature set by the setting device 9.
However, if the operating mode of the device is inside air circulation or the number of occupants is large, the oxygen concentration in the passenger compartment is reduced, and the environmental conditions are likely to cause the driver to fall asleep. The signal L is output, and the air-conditioning temperature of the vehicle air conditioner 1 drops by 10 ° C. from the temperature set by the setting device 9. For this reason, cool air is blown out into the vehicle interior from the air outlet, which can give the driver a drowsiness and an awakening effect, and further encourages the driver to ventilate the vehicle interior air. As a result, safe driving is achieved.

In the above-described embodiment, the value of the subtraction value data X when the density reduction signal L is output is constant at X2. However, as shown in FIG. 3, for example, the second value shown in FIG.
Instead of the fixed data generation unit 104, a variable data generation unit that outputs data X3 of a value corresponding to the oxygen concentration at that time in response to the oxygen concentration signal F is used, and when the oxygen concentration becomes smaller than the predetermined value M, Subtraction value data X according to the density value
May be changed.

In the configuration of FIG. 3, the subtraction value data X is obtained by using the two data generators 103 and 105 and the changeover switch 105. For example, as shown in FIG. In response to F, the value of the subtraction value data X may be determined by a map operation according to the characteristic shown in FIG. 5, and a subtraction amount determination unit 107 that provides the determination result to the subtraction unit 102 as the subtraction data X may be provided.

Further, in the configuration shown in FIGS. 2 and 3, for example, as shown in FIG. 6, a pulse signal P having a relatively long cycle (for example, several seconds to several tens of seconds) is activated in response to the concentration reduction signal L. May be provided, and the pulse signal P may be used to intermittently lower the set temperature during the period in which the oxygen concentration is lower than M, thereby prompting the driver to wake up. .

In each of the above embodiments, the decrease in the oxygen concentration in the passenger compartment is detected, and the set temperature for air conditioning is reduced continuously or intermittently during the period to make the driver drowsy. Although the configuration described above has been described, instead of detecting the oxygen concentration, the concentration of carbon dioxide in the vehicle compartment is detected, and when the concentration becomes equal to or higher than a predetermined value, the setting is performed in the same manner as the above-described embodiment. The temperature signal D may be changed so as to wake up the driver. FIG. 7 shows a vehicle air conditioner having such a configuration.

The vehicle air conditioner 1 shown in FIG.
00 is a carbon dioxide concentration determination unit that responds to a carbon dioxide concentration signal G indicating the carbon dioxide concentration in the vehicle cabin obtained from the carbon dioxide concentration sensor 14 and determines whether the carbon dioxide concentration has become greater than a predetermined value N. In response to the concentration increase signal H output from the apparatus when the carbon dioxide concentration becomes greater than N, the set temperature indicated by the set temperature signal D is changed by the set value changing unit 10 and the set temperature is changed. An output signal E indicating the density is output. 7, the same components as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. Here, the setting value changing unit 10 can be configured similarly to the configuration illustrated in FIGS. 2 and 3.

According to the vehicle air conditioner 100 shown in FIG. 7, when the concentration of carbon dioxide in the cabin is larger than the predetermined value N and the driver is likely to fall asleep, A rising signal H is output, whereby
The set temperature value set by the setter 9 is set to a lower value.

As a result, cool air is blown into the passenger compartment from the outlet to awaken the driver's drowsiness, which can provide an awakening effect, and further encourages the driver to ventilate the passenger compartment air. As a result, safe driving is achieved.

FIG. 8 shows an example of the configuration of the set value changing unit 10, and this configuration corresponds to FIG.

The structure of FIG. 8 will be described.
A value 0 indicates that the value of the subtraction value data X is map-calculated in accordance with the characteristic shown in FIG. 9 in response to the carbon dioxide concentration signal G, and the data indicating the calculation result is output as the subtraction data X. The subtraction unit 102 outputs a result obtained by subtracting the subtraction data X from the digital set temperature data DD as an output signal E.

In the case of the embodiment shown in FIG. 7, the change of the set temperature is performed, for example, by the configuration shown in FIG.
Of course, it can be performed intermittently.

Although the embodiments of the present invention have been described, the configuration of the present invention is not limited to these embodiments. For example, a predetermined control program is executed by a microcomputer, whereby each embodiment is executed. It is easy to understand that a configuration equivalent to the function described above may be employed.

[0030]

According to the present invention, as described above, the concentration of oxygen or carbon dioxide in a vehicle compartment is detected, and according to the result,
It is determined whether or not the vehicle is in an environmental condition that causes the driver to fall asleep, and if it is determined that the vehicle is in an environmental condition that causes the driver to fall asleep, the air conditioning set by the occupant at that time is determined. A change was made to lower the set temperature, which allowed the driver to wake up by discharging cold air from the air outlet, thereby giving the driver and other occupants uncomfortable feelings and driving safety. It can secure the property.

[Brief description of the drawings]

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

FIG. 2 is a detailed block diagram illustrating an example of a configuration of a setting value changing unit in FIG. 1;

FIG. 3 is a detailed block diagram showing another example of the configuration of the set value changing unit in FIG. 1;

FIG. 4 is a detailed block diagram showing still another configuration example of the set value changing unit in FIG. 1;

FIG. 5 is a characteristic diagram showing input / output characteristics of a subtraction amount determination unit in FIG. 4;

FIG. 6 is a main part block diagram for explaining a modification of the configuration shown in FIGS. 2 and 3;

FIG. 7 is a block diagram showing another embodiment of the present invention.

8 is a detailed block diagram showing an example of a configuration of a setting value changing unit in FIG.

FIG. 9 is a characteristic diagram showing input / output characteristics of a subtraction amount determination unit in FIG. 8;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Air-shower device for vehicles 9 Setter 10 Setting value change block 12 Oxygen concentration sensor 13 Oxygen concentration discriminator 14 Carbon dioxide concentration sensor 15 Carbon dioxide concentration discriminator

Claims (1)

(57) [Claims] 1. An air conditioner for a vehicle, comprising: detecting means for detecting the concentration of oxygen or carbon dioxide in a vehicle cabin; and whether the environment in the vehicle cabin is in a state of promoting driver's drowsiness in response to the detecting means. Determination means for determining whether or not the temperature of the air conditioner is set in advance when it is determined in response to the determination means that the environment in the vehicle compartment is in a state that promotes the driver to fall asleep. Means for lowering the air conditioner.