JPS6312806B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a controlled temperature display device for a car air conditioner (automobile air conditioner), which has an automatic temperature control function and is called an automatic air conditioner.

Attempts have been made to use digital computers to increase the precision or diversify the control functions of car air conditioners. In this device, it has also been considered to display the adjusted temperature, that is, the actual temperature in the passenger compartment, by means of a digital display for the benefit of the occupants.

By the way, the temperature control of a car air conditioner involves adding a temperature signal from a temperature sensor placed inside the car and, if necessary, a temperature signal from a temperature sensor placed outside the car to keep the temperature in the car close to the target value. It is executed by an electric control unit to do so. At this time, the vehicle interior temperature generally draws a pattern in which it rapidly approaches the target value and gradually approaches the target value. However, if the temperature inside the vehicle is measured strictly, it will vary slightly due to various factors such as displacement of temperature control members, changes in heat exchanger capacity, changes in airflow, and disturbances such as sunlight entering the vehicle interior. It can be seen that it fluctuates.

SUMMARY OF THE INVENTION In view of the above-mentioned circumstances, it is an object of the present invention to provide a temperature display device that provides a preferable display form for displaying the adjusted temperature using a digital display. More specifically, the present invention digitally processes the temperature signal from the temperature sensor to periodically change the display on the digital display, and when the adjusted temperature converges to the target temperature, the temperature signal is actually relatively large. Even if temperature fluctuations occur, they are not displayed as they are, but by reducing the displayed fluctuation width, it is possible to display how the adjusted temperature quickly changes depending on the adjustment results of the car air conditioner before it converges.
After that, it is possible to display that temperature control is being performed stably.

The present invention will be described below with reference to embodiments shown in the accompanying drawings. In FIG. 1, 10 is a temperature sensor placed inside the vehicle interior, 11 is a temperature sensor placed outside the vehicle interior, and temperature-dependent analog voltage signals generated by both temperature sensors are inputted to a digital computer 13 via a multiplexer 12. . The digital computer 13 has a built-in A-D converter 14,
The temperature signal obtained from the temperature sensor is digitally processed and various adjustment members 16 to 20 of the air conditioning unit are processed.
control. 15 is an output driver that amplifies the output signal of the computer 13 and controls the adjustment members 16 to 20.
to drive. In the adjustment members 16 to 20, 16
is the inside/outside air switching damper, 17 is the blower motor, 18
is an air mix damper as a temperature regulating member, 1
9 is an outlet switching damper, and 20 is an electromagnetic clutch for driving the compressor. 22 is the switch panel,
23 is a digital display for temperature display, which uses three 7-segment light emitting elements and is designed to display up to one decimal point. 24 is a display driver that transmits temperature data received from the computer 13 to the display 23.
This is what is displayed.

The digital computer 13 has an adjustment member 16
20 and also controls the temperature display 23. The control of the adjustment member 18 is disclosed in, for example, Japanese Patent Application Laid-Open No. 55-47914, so a brief explanation will be given here.

FIG. 2 is a flowchart showing control functions by the digital computer 13, and schematically shows a control program. First, when the automobile key switch is turned on, the computer 13 receives operating power from a power supply circuit (not shown) and starts processing at step 100. Subsequently, in an initialization step 101, internal registers and timers for storing calculation variables are initialized. Subsequently, in check step 102, a self-diagnosis is performed to see if there is any failure in the sensors 10, 11 or other parts. This check takes several tens of milliseconds, for example 60m.
Repeats until seconds have elapsed. Note that the details of the check program will not be explained because they are not the gist of this invention.

Next, the vehicle interior temperature is set to a predetermined target temperature.
Step 104 of determining the temperature adjustment amount to approach and maintain TSET (which may be input via the switch panel 22) and controlling the air mix damper 18, and controlling the opening/closing of the inside/outside air switching damper 16. Step 105, air outlet switching damper 1
9, step 107 to control the rotational speed of the blower motor 17, and step 10 to control the on/off of the electromagnetic clutch 20.
8. Process step 109 for controlling the display 23 cyclically. The processing order of each step may be changed as appropriate. Then, each step 104 to 109
It takes several hundred milliseconds to 1 or 2 seconds to execute the steps once. In this embodiment, the display adjustment step 109 is executed at this time interval, and the display 23 is adjusted at the same interval. The display is set to change. Note that the display adjustment step may be executed at regular time intervals using a programming method such as a timer interrupt.

FIG. 3 shows a timer interrupt program that is executed by the computer 13 at 10 msec intervals, and the main program shown in FIG. 2 is executed every 10 msec by the timer counter built into the computer 13. Pause and run this program periodically. In this interrupt program, when an interrupt is accepted in step 201,
At the analog input step 202, the temperature sensor 10,
11 is selectively inputted to the analog format temperature signal via the multiplexer 12 and sent to the A-D converter 14.
are digitized and stored as the vehicle interior temperature Tr and vehicle exterior temperature Tam, respectively. In step 203, this temperature data obtained at 10 msec intervals is averaged for the past five data and stored as average data TR, TAM representing up to one digit after the decimal point. These data TR and TAM are read out and used as appropriate in each of the adjustment steps 104 to 109 described above. Note that the interrupt program starts accepting applications immediately after the initialization step 101, and one average data TR, TAM is prepared before it is determined in step 103 that 60 milliseconds have elapsed. In step 204, input the ON state of each switch such as the air conditioner switch, the internal/external air manual changeover switch, the defrost blow request switch, etc. from the switch panel 22.
In order to resume execution of the main program interrupted in step 5, the address of the control program is restored.

FIG. 4 shows details of the display adjustment step 109. First, in step 301, the on state of the air conditioner switch (inputted in step 204) is checked, and if it is not on (that is, automatic temperature control is not requested). ), and in step 309, the vehicle room temperature data TR is used as display data Dt, and
In step 311, the data is transferred to the display driver 24.
Therefore, the display 23 faithfully displays the vehicle interior temperature at that time.

When the air conditioner switch is turned on, the vehicle interior temperature TR and the target temperature are determined in step 302.
The difference △T from TSET is calculated, then step 30
3, it is checked whether this difference ΔT is greater than ±1°C. If it is larger than ±1°C, the judgment result becomes YES and the process proceeds to step 309. That is, before the adjusted temperature TR converges, the display data Dt is displayed in step 309 in accordance with the vehicle interior temperature TR, faithfully displaying the state in which the vehicle interior temperature changes as the adjustment is performed. Note that the temperature for determining whether convergence has been achieved is not limited to ±1℃, but ±2 to 3℃.
It may be determined by the degree.

Next, in step 304, the latest vehicle temperature data TR and the previous vehicle temperature data TRo (approximately 1 second ago) are compared.
In other words, the variation range △TR of the vehicle room temperature is calculated. It is checked in steps 305 and 306 whether this fluctuation range is larger than 0.2°C. if,
If the fluctuation range △TR is larger than 0.2℃, step 30
7,308, the display data Dt is corrected and determined by regarding the fluctuation range as 0.2°C. Fluctuation range △TR is ±
If it is within 0.2°C, it is used as display data in step 309. In step 310, the displayed temperature data Dt is saved as old data for next time.
Remember as TRo.

Therefore, when the difference between the adjusted temperature TR and the target temperature TSET falls within a predetermined range (for example, within 1°C) and the adjusted temperature TR has converged, the adjusted temperature TR
Even if the temperature fluctuates within the above 1℃, the adjusted temperature
TR is corrected to an appropriate value within the above 1°C (0.2°C in the above example) and displayed. Therefore,
When the adjusted temperature TR has converged near the target temperature, unnecessary flickering of the display due to small temperature fluctuations is prevented, and the temperature display can be made easier to read. However, even after the temperature has converged, due to stopping the engine or opening the door, the target temperature TSET will be 1°C lower than the target temperature TSET.
If there is a change exceeding this value, the change will be displayed accordingly.

Steps 300 and 312 are provided to prevent the interrupt program shown in FIG. 3 from being activated during display adjustment and from changing the data being processed.

Note that the above-mentioned specific numerical values can be changed arbitrarily as necessary. Furthermore, the present invention can be implemented not only by a digital computer based on a software program but also by a hard logic circuit.

As described above, the present invention provides a device that displays the interior temperature of a car air conditioner on a digital display, and has the excellent effect of realizing an easy-to-read display that is suitable for the actual situation of automatic temperature control of car air conditioners. be.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram showing one embodiment of the present invention, FIGS. 2 and 3 are flowcharts showing the main control program and timer interrupt program of the microcomputer shown in FIG. 1, respectively, and FIG. 2 is a flowchart showing details of step 109 in FIG. 2. 10...Temperature sensor, 12...Multiplexer, 13...Microcomputer serving as a control device, 14...A-D converter, 18...Air mix damper as a temperature control member, 23...Digital display, 24...Display driver.

Claims (1)

[Claims] 1. In a car air conditioner that controls a temperature control member using a temperature signal generated by a temperature sensor placed in the vehicle interior to maintain the vehicle interior temperature close to a target value,
A digital temperature display; a temperature signal from the temperature sensor is digitally processed and periodically applied to the temperature display, and when the temperature signal falls within a predetermined range of the target value, the temperature signal changes; 1. A temperature display device for a car air conditioner, comprising: a control device that corrects and provides a temperature below a predetermined value.