JPS643687B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vehicle air conditioning control device that automatically switches between internal air circulation and outside air introduction in an air conditioner (car air conditioner) of a vehicle such as an automobile.

Conventionally, this type of air conditioning unit has an upstream side that selectively communicates with the exterior and interior of the vehicle, and a downstream side that communicates with the interior of the vehicle. and a detector that generates an electrical signal in accordance with an impurity component contained in the air outside the vehicle, the vehicle air conditioning control device comprising: an actuator that selects the Japanese Patent Publication No. 47-36974 discloses a control device for causing internal air circulation (intra-vehicle air intake state).

However, this known technique only discloses that when the electrical signal of the detector becomes larger than a set value, the system switches from outside air introduction to inside air circulation.

On the other hand, when using a gas detector as a means of detection, there are currently several types of gas detectors including semiconductor types, but considering the structure, price, etc., solid heat conduction type gas detectors are used for automobiles. A detector is considered suitable. The operating principle of this type of gas detector is that metal oxide semiconductors such as SnO2
This method takes advantage of the fact that the thermal conductivity of the semiconductor increases when it is heated to 500℃ and flammable gas is adsorbed, resulting in better heat dissipation, lowering the temperature of the semiconductor, and reducing the drop in temperature of the platinum wire for semiconductor heating. be.

By the way, in order to detect pollution in the air outside the vehicle, the inventor placed the gas detector in the air intake passageway outside the vehicle, and when driving in a city or suburban area, a bridge with the gas detector on one side was installed. An experiment was conducted to determine how the deviation voltage changes when a vehicle starts from an intersection in an urban area, and the voltage increases significantly when detecting exhaust gas from a vehicle while driving behind a large truck in the suburbs. The results showed that there was no significant increase in the number of cases.

Therefore, if control is performed using a simple detection method as shown in the above-mentioned known technology, the system will switch from introducing outside air to internal air circulation every time the vehicle starts from an intersection, while at the same time switching from introducing outside air to internal air circulation while driving. The undesirable result is that even if you drive behind a large truck where the problem is occurring, the system will not switch to internal air circulation.

In view of the above-mentioned problems, the present invention has been developed in such a way that when driving at relatively low speeds such as in a city, switching between inside and outside air is not performed very sensitively, and when driving at relatively high speeds such as in the suburbs, switching between inside and outside air is not performed very sensitively. It is an object of the present invention to provide an air conditioning control device for a vehicle that can switch between inside and outside air in a sensitive manner and match the feeling of an occupant.

In order to achieve the above object, the present invention provides an air conditioning unit that selectively communicates the upstream side with the exterior of the vehicle and the interior of the vehicle, and the downstream side that communicates with the interior of the vehicle. an actuator that selects air intake; a detector that generates a detection signal corresponding to impurity components contained in the air outside the vehicle; a vehicle speed detection means that generates a detection signal corresponding to the vehicle speed; and a detection signal from the detector and a predetermined detection signal. determine that the impurity component is large by comparing with the detection level of
Control means is provided for controlling the actuator to select air intake into the vehicle interior, and for changing the detection level in accordance with the detection signal of the vehicle speed detection means so that the higher the vehicle speed, the more sensitive the determination is. Adopt technological measures.

According to the configuration of the present invention, the control means sensitively determines that there is a large amount of impurity components at high vehicle speeds in response to the detection signal from the detector corresponding to the impurity component, and controls the air conditioning unit to intake air into the vehicle interior. Make the switch.

This prevents the vehicle from frequently switching to internal air circulation when starting at an intersection at low speeds, and also sensitively switches to internal air circulation when dealing with exhaust gas from large trucks at high vehicle speeds, improving the passenger's feeling. Appropriate internal/external air switching can be performed that reasonably matches the internal/external air.

The present invention will be described below with reference to embodiments shown in the drawings. FIG. 1 is an overall configuration diagram in which the device of the present invention is incorporated into an automatic air conditioner (automatic air conditioning control device) controlled by a microcomputer.

1 is a car air conditioner duct installed in a car, which introduces air from outside the car through the outside air intake port 1a.
In addition, cabin air is taken in from the inside air intake port 1b and circulated.

Reference numeral 2 denotes an inside/outside air switching damper which selectively opens the outside air intake port 1a and the inside air intake port 1b to switch between outside air introduction and inside air circulation. and,
Although not shown, inside the duct 1 there are a blower for blowing air, an evaporator for cooling the air, and a heater core for heating the air.
It has an adjustment unit 1c equipped with an air mix damper etc. to adjust the rate of heating and cooling,
The air conditioning inside the vehicle compartment 3 is controlled by adjusting the temperature by mixing the cold air and the warm air.

4 is a gas detector (hereinafter referred to as gas sensor) that detects the concentration of harmful gas in the air outside the vehicle and generates an analog signal according to the concentration, which is placed in the outside air inflow passage 1a; The data is taken into the microcomputer 6 via the converter. Here, the A/D converter 5 also has a multiplexer function, which sequentially converts analog signals from an internal temperature sensor 7 or an outside temperature sensor (not shown) related to the auto air conditioner into digital values and provides the digital values to the computer 6. There is. Which analog input to A/D
A command to perform the conversion is given from the microcomputer 6 to the A/D converter 5.

Here, the gas sensor 4 is of a known solid thermal conductive type using a metal oxide semiconductor such as SnO2, and its resistance value is changed by adhesion of flammable gas. Of course, gas sensors of other compositions can also be used.

8 is an electromechanical actuator that operates the inside/outside air switching damper 2; for example, a diaphragm actuator operated by engine negative pressure is used;
is set to the outside air intake state, and when an operation control signal for this actuator is applied from the output port with a latch of the microcomputer 6, it is energized and set to the inside air intake state. 8 is the adjustment unit 1c
It is an electromechanical actuator that operates the air conditioner, and is controlled based on the automatic air conditioner processing of the microcomputer 6.

9 is a switch and display for operating the automatic air conditioner, and 9a is a switch and display for instructing the operation of the automatic air conditioner and the automatic switching between inside and outside air; when this switch is pressed, the internal lamp lights up and the switch is in auto mode. It is designed to notify the crew that this is the case. Similarly, 9b is a switch and display section for introducing outside air, and 9c is a switch and display section for internal air circulation. Each switch is of an automatic return type using a spring, and the instruction signal of each switch is taken in by the microcomputer 6 at a predetermined period.

10 is a known vehicle speed sensor using a reed switch and a magnet, 11 is a converter that converts the ON-OFF state of the contact of the vehicle speed sensor reed switch into a logic level, and 12 is a vehicle speed sensor.
This is an F-V converter that converts the ON-OFF interval, that is, the vehicle speed, into an analog quantity. The output of this F-V converter is given to a microcomputer 6 via 5.

Reference numeral 13 denotes a stabilizing voltage circuit which receives power supply voltage VB from the vehicle battery when the key switch of the automobile is turned on and generates a constant stable voltage Vc. An initialization circuit 14 generates a start signal for starting the program processing of the microcomputer 6 from an initial address based on the rise of the stable voltage Vc.

Figures 2 and 3 show the microcomputer 6.
3 shows a control program for a portion of the arithmetic processing executed by the present invention.

Then, when the key switch of the automobile is turned on, power VB is supplied to the control device shown in FIG. 1, and based on this, the microcomputer 6 starts executing the control program from step 100 of the main control routine shown in FIG. 2a. . And step 101
Initialize the calculation variables necessary for control.

Next, in step 102, it is determined whether or not the arithmetic processing timing for each fixed cycle has been reached, and when the result of this determination is YES, the automatic air conditioner processing routine 103 and the internal/external air switching processing routine 104 are executed in sequence. Both processes are executed at a constant cycle of about several 100 ms. Here, the auto air conditioner processing 103 controls the adjustment unit 1c in response to signals from the inside temperature sensor 7 and other temperature sensors and setters (not shown), and operates to air condition the vehicle interior 3. Note that the specific contents of this automatic air conditioner processing 103 are not the gist of the present invention, so a detailed explanation will be omitted. Details of the inside/outside air switching process 104 are shown in FIG.

The microcomputer 6 executes the main control routine shown in FIG. 2a, and also executes the timer interrupt routine shown in FIG. 2b at a cycle of about 10 ms.
That is, each time the count value of the time counter built in the computer 6 reaches a value corresponding to a predetermined time of about 10 ms, the calculation process of the main control routine is temporarily interrupted and the timer interrupt process is executed. At the end, the main control routine is resumed.

In the timer interrupt processing, step 200
When a processing command is received from the internal time counter, the program address of the main control routine is stored in the save register, and the timer processing 201 and A/D conversion processing 20 are performed.
2. Execute each routine of switch signal processing 203, read the program address saved in the save register in step 204, and resume execution of the main control routine.

In the timer processing routine 201, the timer counter To set in the memory of the computer 6 is
The count value is incremented every time a timer interrupt is executed, and the counted value can be used to determine whether a predetermined value has been reached in the determination step 102 described above. Note that this timer counter To is set so that when it reaches this predetermined value and is further incremented, the count value returns to zero.

In the A/D conversion processing routine 202, the A/D conversion processing routine 202
The D converter 5 is instructed to selectively convert analog signals indicating the sensors 5, 7 and vehicle speed into digital values, and the obtained digital values are stored in a predetermined memory address of the computer 6. Here, to prevent noise, the average value of several digital values may be calculated.

Next, in a switch signal processing routine 203, the closed state of each switch is checked sequentially from the operation switch and display section 9. When there is an instruction signal from the first switch 9a, the calculation variables (plugs) F1 and Fc are set to 0, and when there is no instruction signal from the first switch 9a and there is an instruction signal from the second switch 9b, only the flag Fc is set. 1 and flag F1 to 0.
shall be. Further, if there are no instruction signals from the first and second switches 9a and 9b, but there is an instruction signal from the third switch 9c, only the flag F1 is set to 1 and the flag Fc is set to 0. Also, when none of the first, second, and third switches are turned on, flags F1 and Fc
retains its previous value.

FIG. 3 shows details of the inside/outside air switching process in the microcomputer 6. The operation of the apparatus will be explained below according to a flowchart showing this control program.

In steps 300 and 301, flags F0 and F1 are set.
and turn on the first, second, and third switches 9.
It is determined which control mode is instructed by a to 9c.

Then, when the second switch 9b is turned on, in other words, instructing intake of inside air, the flag F1 becomes 1, so an operation control signal is outputted to the actuator 8 in step 302, and the inside/outside air switching damper 2 is switched to the inside air intake. Drive to intake state. On the other hand, when the third switch 9c is turned on, the flag F0 becomes 1, and in step 303, the operation control signal to the actuator 8 is deactivated, and the inside/outside air switching damper 2 is returned to the outside air intake state. By turning on the second and third switches 9b and 9c in this manner, the desired air intake mode of the inside/outside air switching damper 2 can be set.

On the other hand, if the first switch 9a is turned on and the automatic switching mode is instructed, or if no switch is turned on from the beginning, step 304 is performed.
Through the processes in steps 307 to 307, internal air intake and outside air intake are automatically controlled according to the value of the output signal of the gas sensor 4.

First, in step 304, a detection level TH corresponding to the vehicle speed V is calculated. The calculation formula is
TH=A/V+B, where A and B are constants.
That is, as the vehicle speed decreases, the detection level increases, and as the vehicle speed increases, the detection level decreases.
Next, in step 305, the relative output value of the gas detector is calculated. The calculation formula is Vout = Vs - Vmin, where Vs is the current output level of the gas detector 4, and Vmin is the voltage that is turned off after the car's ignition is turned on, that is, after the voltage is applied to the gas detector 4. This is the lowest output value until

However, the reason for using the above-mentioned relative output value instead of using the output value of the gas detector as it is is to make the device according to the present invention stable against changes in temperature and humidity of the gas detector 4 and changes over time. This is to make it work.

Since the relative output value Vout of the gas detector 4 obtained in step 305 is relative to the degree of pollution of the air outside the vehicle, steps 306 and 3 are then performed.
At 07, the internal/external air switching damper 2 is automatically controlled.

First, in step 306, the gas detector 4
If the relative output value Vout is larger than the detection level TH previously calculated in step 304,
In step 302, the inside air intake state is set. On the other hand, the amount of contaminated gas decreases and TH-C (C is a constant)
When it becomes smaller, it is returned to the outside air intake position in step 303.

In the embodiment described above, the detection level of the gas sensor is changed sequentially according to the vehicle speed, but for example, if the detection level is changed at a vehicle speed of 30 km/h or lower and then at a vehicle speed of 30 km/h or higher, The calculation in step 304 is no longer necessary, and instead can be achieved by a simple step of comparing the detected vehicle speed with 30 km/h and setting the detection level to TH1 or TH2 depending on the result.

As described above, the present invention changes the detection level of the detector that detects impurity components in the air outside the vehicle depending on the vehicle speed. It no longer reacts sensitively to components and switches from outside air intake to inside air circulation, and also when driving at relatively high speeds, such as when driving behind a large truck that generates exhaust gas accompanied by black smoke. It reacts sensitively to impurities and switches from outside air intake to inside air circulation, which improves the feeling of the occupants so that they do not feel overly sensitive at low vehicle speeds or sensitive at high vehicle speeds. This has the great effect of providing a vehicle air conditioning control device that can switch between inside and outside air in a consistent manner.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of the present invention;
FIG. 2 is a flowchart showing an overview of the control program of the microcomputer in FIG. 1, and FIG. 3 is a flowchart showing details of the main parts of FIG. DESCRIPTION OF SYMBOLS 1...Duct forming an air conditioning unit, 1a...Outside air intake, 1b...Inside air intake, 2, 8...Inside/outside air switching damper and electric/mechanical actuator forming an actuator, 3...Car interior, 4...Constituting a detector Gas sensor, 5
...A/D converter, 6...Microcomputer, 1
0... Vehicle speed sensor, 12... F-V converter.

Claims (1)

[Scope of Claims] 1. An air conditioning unit whose upstream side selectively communicates with the exterior and interior of the vehicle and whose downstream side communicates with the interior of the vehicle; in this air conditioning unit, air intake outside the vehicle interior and air intake into the vehicle interior are connected. an actuator to select, a detector that generates a detection signal according to impurity components contained in the air outside the vehicle, a vehicle speed detection means that generates a detection signal according to the vehicle speed, and a detection signal from the detector and a predetermined detection level. By comparison, it is determined that the impurity component is large,
Control means for controlling the actuator to select air intake into the vehicle interior, and for changing the detection level in accordance with the detection signal of the vehicle speed detection means so that the higher the vehicle speed, the more sensitive the determination becomes. A vehicle air conditioning control device characterized by: