JPS6213211B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an air conditioning control device for an automobile that uses the air conditioning control device of an automobile to give a warning when the engine is overheated. When this overheating condition is detected, the air conditioning control is restricted and the amount of air passing through the heater core is forcibly increased, thereby forcibly increasing the temperature inside the vehicle and reducing engine overheating to the passenger's experience. An object of the present invention is to provide an air conditioning control device for an automobile that can issue a warning.

Therefore, in order to achieve the above object, the present invention provides a heater core that introduces automobile engine cooling water and heats the air passing through it using its heat amount, and an adjusting means that changes the amount of air passing through the heater core, as shown in FIG. and adjustment amount instructing means for instructing the adjustment amount of the adjustment means to bring the interior of the vehicle to a desired temperature, the overheating state detection means for detecting an overheating state of the engine; Based on the detection results of the state detection means,
abnormality determining means for determining that the engine is in an abnormally overheated state; and upon receiving the determination result from the abnormality determining means, forcibly increasing the amount of air passing through the heater core in priority to the instruction from the adjustment amount indicating means; We will adopt a technical means of providing abnormality control means to prevent this.

The present invention will be described below with reference to embodiments shown in the drawings. FIG. 1 is an overall configuration diagram showing one embodiment of the system, in which the air conditioner is controlled using a microcomputer that executes digital arithmetic processing by software according to a predetermined air conditioner control program.

In FIG. 1, reference numeral 1 denotes an air duct of a car air conditioner installed in an automobile, which takes in air from an outside air intake or an inside air intake. 2 is a blower motor that sucks air from an outside air intake or an inside air intake and blows the air. Reference numeral 3 denotes an evaporator through which the air blown by the blower motor 2 is cooled and passed through, and is disposed across the air duct 1. Reference numeral 4 denotes a heater core disposed within the air duct 1, which introduces engine cooling water and heats the blown air through the heater core. 5 is an air mix damper that cools the cooling air that has passed through the evaporator 3.
The ratio of the air to be introduced into the heater core 4 side is adjusted, and the temperature is adjusted by mixing the cold air of the cooling air and the warm air of the heated air, and the air is blown into the vehicle interior 6. The opening degree of this air mix damper 5 is continuously controlled to air condition the interior of the vehicle compartment 6. Reference numeral 7 denotes an automobile engine, and its cooling water is circulated through a valve 8 to the heater core 4. This valve 8 opens the cooling water passage by introducing negative pressure from a negative pressure source by a solenoid valve 9.

10 is a room temperature sensor that detects the temperature inside the vehicle interior 6 and generates a room temperature detection signal; 11 is an opening sensor that detects the opening of the air mix damper 5 and generates an opening signal; A potentiometer linked to the movement of 5 is used to feed back the opening degree for temperature control. 12 is an outside temperature sensor that detects the temperature of the outside air and generates an outside temperature signal; 13 is a temperature setting device that determines the set temperature of the control target; the passenger manually sets the desired room temperature. A cooling water temperature sensor 14 detects the temperature of engine cooling water and generates a cooling water temperature signal. 1
5 is an A/D converter that converts an analog signal into a digital signal, which receives a room temperature signal from the room temperature sensor 10, an opening signal from the opening sensor 11, an outside temperature signal from the outside temperature sensor 12, and a temperature setting device 13. The setting signal and the cooling water temperature signal from the cooling water temperature sensor 14 are sequentially converted into digital signals. 16 is a single-chip microcomputer that executes digital calculation processing of software according to a predetermined air conditioner control program, and is connected to a several megahertz (MHz) crystal oscillator 17, and is powered by the on-board battery. The device is activated by receiving a stabilized voltage from a stabilized power supply circuit (not shown) which is activated by the power source. And this microcomputer 1
6 generates various command signals for controlling various air conditioners and warning in the event of engine overheating.

This microcomputer 16 has a read-only memory (ROM) that stores an air conditioner control program that defines the calculation procedure for generating the above-mentioned command signal, and sequentially reads out the air conditioner control program from this ROM and responds to it. A central processing unit (CPU) that executes arithmetic processing, a memory (RAM) that temporarily stores various data related to the arithmetic processing of this CPU and that can be read by the CPU, and a crystal oscillator 17. A one-chip large-scale integrated circuit (LSI) whose main parts are a clock generator that generates reference clock pulses for the various calculations mentioned above, and an input/output (I/O) circuit that adjusts the input and output of various signals. It is made by

Reference numeral 18 denotes an opening drive circuit which stores an opening increase command signal or an opening decrease command signal from the microcomputer 16 and releases the memory upon receiving a reset signal. In addition to the adjustment actuator 19, the opening degree of the air mix damper 5 is adjusted and controlled. 20 is a blower drive circuit that stores the blower speed command signal from the microcomputer 16 and adjusts the rotational speed of the blower motor 2 based on the stored signal to adjust the amount of air blown from the air duct 1 to the passenger compartment 6. It is something. 21 is the valve drive circuit,
The opening and closing of the solenoid valve 9 is controlled by latching a drive command signal or a reset signal from the microcomputer 16. 22 is an alarm device that latches an alarm signal from the microcomputer 16 to issue an alarm;
When a reset signal is applied, the alarm is stopped. Through the arithmetic processing of the microcomputer 16, the air conditioning in the passenger compartment 6 is controlled under normal conditions, and when it is determined that the engine is overheating, the air mix damper 5 is moved to the position indicated by the solid line in the figure, that is, the maximum heating (Max Hot). At the same time, the blower motor 2 is rotated at high speed to maximize the amount of air being blown, and warm air is forced into the passenger compartment 6, so that a warning of engine overheating is visually felt by the occupants.

The blower motor 2 and air mix damper 5 constitute an adjusting means for changing the amount of air passing through the heater core 4, and the cooling water temperature sensor 14, A/D converter 15, and microcomputer 16 Therefore, it constitutes an abnormality control means for forcibly increasing the amount of air passing through the heater core 4 when the engine is overheated.

Next, the operation of the above configuration will be explained with reference to the calculation flowchart in FIG. This figure 2 shows the microcomputer 1 using the air conditioner control program.
6 is a calculation flowchart showing the calculation process of No. 6; FIG.

First, the arithmetic processing of this microcomputer 16 will be explained. Now, in a car equipped with this device, when the vehicle starts driving, the microcomputer 16 is supplied with a stabilized voltage through the stabilized power supply circuit, and is activated for several tens of milliseconds (m
The arithmetic processing of the air conditioner control program is executed for about several milliseconds at a period of about 10 seconds.

That is, when the arithmetic processing of the microcomputer 16 reaches the air conditioner control program, the second
The calculation process starts from the overheating flag determination step 101 in the figure. This overheating flag judgment step 1
In step 01, the presence or absence of the overheat flag H=1 is determined, and when engine overheating occurs, the determination becomes YES, but when normal, the determination becomes NO, and the air conditioner control calculation routine 102
Proceed to. This calculation routine 102 includes a room temperature signal Tr from the room temperature sensor 10, an opening signal θ from the opening sensor 11, and an outside temperature signal from the outside temperature sensor 12.
Tam, the setting signal Tset from the temperature setting device 13 is sequentially converted into a digital signal by the A/D converter 15 and input into the microcomputer 16,
The opening increase command signal, the opening decrease command signal, and the reset signal are applied to the opening drive circuit 18 so as to maintain the relationship of K ₁ · Tset = K ₂ + Tr + K ₃ · Tam + K ₄ · θ, and the setting signal Tset and room temperature signal are applied. A blower speed command signal is applied to the blower drive circuit 20 to reduce the blower speed as the deviation of Tr becomes smaller, and a drive command signal to turn on the solenoid valve 9 when the air conditioner is activated is applied to the valve drive circuit 21. The process advances to water temperature input step 105.

On the other hand, when the overheat flag determination step 101 becomes YES due to engine overheating, the process does not proceed to the air conditioner control calculation routine 102, but proceeds to the special command step 103, where the air mix damper 5 is controlled as shown by the solid line in FIG. Maximum heating position (Max
An opening command signal to control the speed of the blower motor 2 to maximum (Hi) and a speed command signal to control the speed of the blower motor 2 to the maximum (Hi).
In addition, the process proceeds to an alarm setting step 104, where an alarm set signal is applied to the alarm 22, and the process proceeds to a water temperature input step 105.

In this water temperature input step 105, the cooling water temperature signal Tw from the cooling water temperature sensor 14 is input to the A/D converter 1.
In step 5, it is converted into a digital signal and input into the microcomputer 16, and in the next overheating judgment step 106, it is determined whether the cooling water temperature Tw is higher than T ₀ =95°C using the relational expression Tw > T ₀ . If it is normal, the judgment will be NO and the flag will be cleared in step 1.
At step 07, the overheating flag is cleared by setting H=0, and at alarm reset step 108, a reset signal is applied to the alarm 22, and the process proceeds to setting step 109, where _{T0 is} set.
= 95℃ and proceed to the outstep.

On the other hand, when the engine cooling water temperature Tw becomes higher than 95°C, the engine becomes overheated and the determination in the overheat determination step 106 becomes YES, and the process proceeds to the overheat flag setting step 110, where the overheat flag H=1 is set. Next valve open command step 1
At step 11, a valve opening command signal is applied to the valve drive circuit 21 with priority over the control by the calculation of the air conditioner control calculation routine 102, and the next setting step 112 is performed.
Proceed to , change the setting level to T ₀ = 85℃, and proceed to the out step. The above calculation process takes several milliseconds.
One calculation of degree is performed.

Next, the overall operation in various states will be explained.

First, when the automobile starts driving, a stabilized power supply circuit (not shown) starts operating, and the stabilized voltage is supplied to each circuit section including the microcomputer 16, and the microcomputer 16 starts operating. With this start of operation, microcomputer 1
Step 6 performs initial settings, and then comes the arithmetic processing of the air conditioner control program. At this time, H=0, which corresponds to cancellation of the overheating flag, is set for the initial setting operation. Therefore, the overheating flag determination step 101 is reached from the instep of FIG. 2, and the determination is NO.
The air conditioner control calculation routine 102, water temperature input step 105, overheating determination step 106,
The calculation process leading to the out step through the flag release step 107, alarm reset step 108, and setting step 109 is repeated periodically.

As a result, the air conditioner control calculation routine 102
By calculating each signal of the room temperature sensor 10, opening sensor 11, outside temperature sensor 12, and temperature setting device 13,
The D converter 15 converts it into a digital signal and inputs it, and the signal is processed to generate various command signals, which adjust the opening of the air mix damper 5 through the opening drive circuit 18 and the opening actuator 19. Also, the rotational speed of the blower motor 2 is adjusted through the blower drive circuit 20, and the solenoid valve 9 is turned on through the valve drive circuit 21, the valve 8 is opened, and the temperature inside the passenger compartment 6 is set to the temperature setter 13. The temperature is adjusted and controlled. Further, the alarm 22 is maintained in a non-operating state by the reset signal of the alarm reset step 108.

During this operation, the cooling water temperature Tw rose to 95℃ due to engine overheating.
When the overheating judgment step 106 is reached, the judgment is reversed from NO to YES based on the data of the cooling water temperature Tw that is input and stored through the A/D converter 15 from the cooling water temperature sensor 14 that detects the temperature. Then, the process proceeds to overheat flag setting step 110 to set the overheat flag H=1, and in valve open command step 111, a valve open command signal is applied to the valve drive circuit 21 to turn on the solenoid valve 9 and maintain the valve 8 in the open state. Then, in setting step 112, T ₀ is set to 85° C. to provide hysteresis for overheating determination, and the outstep is reached. Therefore, several tens of meters
When the overheating flag determination step 101 is reached in the next calculation after sec, the determination is reversed from NO to YES, and instead of proceeding to the air conditioner control calculation routine 102, the program proceeds to the special command step 103, and the air mix damper 5 is set to the solid line shown in the figure. An opening command signal for adjusting the blower motor 2 to the maximum heating position is applied to the opening driving circuit 18, and a speed command signal for controlling the blower motor 2 to the maximum speed (Hi) is applied to the blower driving circuit 20. Proceeding to step 104, a warning set signal is applied to the alarm 22 to generate an engine overheat warning. Therefore, after the maximum amount of air is blown by the blower motor 2 and is cooled through the evaporator 3, all of the cooled air passes through the heater core 4 and forcibly sends warm air into the passenger compartment 6, raising the room temperature and improving the temperature of the occupants. You can feel the engine overheating.

Furthermore, since the cooling air from the evaporator 3 is introduced into the heater core 4 through which engine cooling water circulates, the temperature rise of the cooling water can be limited, which is useful in preventing the engine from overheating. be.

Thereafter, when the engine cooling water temperature decreases to 85°C or less, the overheating determination step 106 is reached, and the determination returns to NO. H=0, the alarm of the alarm device 22 is stopped, and the setting level for overheating judgment is returned to T ₀ =95°C. Therefore, in the next calculation, the determination in the overheating flag determination step 101 will be
Reverses to NO and air conditioner control calculation routine 102
, the air conditioner returns to normal control, and the vehicle compartment 6
The internal temperature is adjusted and controlled to the set temperature set in the temperature setting device 13.

In addition, in the above-mentioned embodiment, the air mix damper 5
The amount of air passing through the heater core 4 is changed by adjusting the opening degree of the heater core 4 and the rotation speed of the blower motor 2. In that case, the rotational speed of the dedicated blower motor may be forcibly controlled to a high speed by the abnormality control means when the engine overheats.

Further, although the microcomputer 16 is shown as an example, a similar control may be performed using a hardware digital electronic circuit or an analog electronic circuit.

Furthermore, in addition to the control for forcibly increasing the amount of air passing through the heater core 4 when the engine is overheated, the inside/outside air switching damper that selectively switches between internal air circulation and outside air introduction may be controlled to be switched to the outside air introduction side.

Furthermore, as an example of an air conditioning control device, a reheat air mix type in which all of the blown air is passed once through an evaporator and some or all of the cooled air is passed through a heater core and mixed is shown as an example. Other types, such as a parallel air mix type that mixes air and heated air, may also be used.

As described above, in the present invention, when overheating of the automobile engine is detected, an abnormality control means is provided that limits the air conditioning control and forcibly increases the amount of air passing through the heater core that guides the engine cooling water. When the engine overheats, the temperature inside the cabin is forcibly raised to alert the occupants of the overheating.Furthermore, by increasing the amount of air passing through the heater core, the temperature rise in the engine cooling water can be prevented. It has the excellent effect of restricting the engine temperature and preventing the engine from overheating.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram showing an embodiment of the present invention;
FIG. 2 is a calculation flowchart showing the calculation processing of the microcomputer in FIG. 1, and FIG. 3 is a block diagram showing the configuration of the present invention. 2, 5... Blower motor and air mix damper forming adjustment means, 3... Evaporator, 4... Heater core, 6... Vehicle interior, 7... Engine, 14,
15, 16... A cooling water temperature sensor, an A/D converter, and a microcomputer that constitute abnormality control means.

Claims (1)

[Scope of Claims] 1. A heater core that introduces automobile engine cooling water and heats passing air using the heat quantity thereof, and an adjusting means that changes the amount of air that passes through this heater core.
An air conditioning control device for an automobile, comprising: an adjustment amount indicating means for instructing the adjusting means of the adjusting means to bring the interior of the vehicle to a desired temperature; an overheating state detecting means for detecting an overheating state of the engine; Based on the detection results of the means,
abnormality determining means for determining that the engine is in an abnormal overheating state; and based on the abnormal overheating determination result from the abnormality determining means, forcibly increasing the amount of air passing through the heater core in priority to the instruction from the adjustment amount indicating means. An air conditioning control device for an automobile, characterized in that it is provided with an abnormality control means for causing an abnormality to occur.