JPS63212120A - Outside air temperature display method for automobile - Google Patents

Abstract

PURPOSE:To prevent adverse effects caused by disturbance, by increasing stepwise a display value by a prescribed temperature very prescribed period of time only when an automobile travels at a car speed greater than a prescribed speed for a period of time longer than a prescribed period of time with a result that an outside air temperature after the traveling is higher than a temperature displayed before the traveling. CONSTITUTION:To display a temperature, when an engine starts, an initial measurement is effected by an outside air temperature sensor in response to an ON signal from an ignition switch to display the measuring valued A on a display unit. When the outside air temperature sensor senses another measuring value A', the another measuring value A' is compared with a value B displayed on the display unit before the measurement of the value A'. When the another measuring value A' is the same as the displayed value B or greater than it, it is further discriminated whether the conditions that a car speed is greater than a prescribed value and it continues for a period of time greater than a prescribed value are established. When the conditions are established as a result of the discrimination, the display is changed stepwise by a prescribed temperature every prescribed period of time.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a method for displaying outside air temperature for automobiles.

Conventional technology Outside air temperature display devices in automobiles generally include an outside air temperature sensor installed in a location that is not exposed to direct sunlight and where sufficient outside air circulates while driving, and an outside air temperature sensor installed in the instrument panel inside the vehicle interior. It is usually constructed with a display section that digitally displays, for example, the outside air temperature based on a temperature signal (see, for example, Japanese Utility Model Application Publications No. 124718/1982 and No. 54908/1989).

Problems to be Solved by the Invention In a car, an example of a place where the influence of 1n sunlight is small and where sufficient outside air circulates while driving is the engine room or under the floor near the engine room. Temperature □For models with sensors installed, there is no problem during normal driving as there is sufficient air circulation, but when there is little outside air circulation, such as when stopped or driving at very low speeds, radiant heat from the road surface or mounting Due to the strong influence of radiant heat from the engine, the outside air temperature detected by the outside air temperature sensor is much higher than the normal outside air temperature, and the outside air temperature displayed on the display based on the temperature signal from this outside air temperature sensor is quite different from the actual outside air temperature. It becomes something far apart.

The main purpose of the present invention is to solve the above-mentioned problems and provide an outside temperature display method that can display an approximately accurate outside temperature.

Means for Solving the Problems The present invention provides an outside air temperature display device for an automobile that includes an outside air temperature sensor and a display section that displays the outside air temperature as the outside air temperature sensor measures the outside air temperature. When measuring the outside temperature for the first time, the measured value is displayed on the display, and for subsequent outside temperature measurements, the measured value is compared with the value displayed on the display at that time, and the measured value is determined to be lower than the displayed value. If the measured value is lower than the current value, the display changes to display the measured value, and if the measured value is higher than the currently displayed value, the display switching condition is met, which means that the vehicle has been traveling at a predetermined speed or higher for a predetermined period of time or more. If it is determined that the display switching condition is not met, the display will not be switched to the above measured value and the previous display will be held, and if the display switching condition is met. When the determination is made, the display is changed stepwise by a predetermined temperature at predetermined time intervals by the temperature rise display limiting means.

Effect As described above, when the display switching condition that the vehicle continues to run at a predetermined speed or higher for a predetermined period of time is not met, the outside air temperature sensor section is greatly affected by engine heat, radiant heat from the road surface, etc. Therefore, the measured value is much higher than the actual outside temperature, but by not switching the display based on the measured value under such conditions, it is possible to display a temperature that is almost the same as the actual outside temperature. Furthermore, the value measured by the outside air temperature sensor immediately after the state in which the above display switching condition is not met and the temperature of the outside air temperature sensor is considerably high after the above display switching condition is met becomes the actual value. In many cases, the temperature is still much higher than the outside temperature, but in this case, the temperature rise display limiting means can be used to gradually change the display by a predetermined temperature at a predetermined time interval, to prevent the displayed temperature from suddenly becoming excessive. The unnatural temperature rise is eliminated, and a stable and natural temperature display can be performed.

Example An embodiment of the present invention will be described below with reference to the accompanying drawings.

As shown in the flowchart in Figure 1, first, when the ignition switch is turned on to start the engine, the outside air temperature sensor performs the first outside temperature measurement A based on the ignition switch on signal, and the signal of the first outside temperature measurement A is "Next, when the outside air temperature sensor measures outside air temperature A', the outside air temperature sensor measures the outside air temperature A' and displays the displayed temperature on the display up to that point." If the measured temperature is lower than the displayed temperature, it is assumed that the measured temperature is close to the normal outside temperature, and display B on the display section is switched to display the measured temperature.

If the above outside temperature measurement A' is the same as or higher than the previously displayed temperature, that is, A'≧B, then the vehicle is being affected by road radiant heat or engine radiant heat. If it is determined that there is a possibility, display B on the display will not be changed, and the vehicle speed will be checked to see if it is higher than a predetermined vehicle speed (e.g. 20 km/h) and that the vehicle has been traveling at the predetermined speed or higher for more than a predetermined time (e.g. 1 minute). Find out if it is.

If A'≧B and the vehicle speed is less than the predetermined vehicle speed, it is determined that the outside temperature measurement A' is affected by radiant heat, and the display B on the display remains unchanged, and the timer is set to keep the temperature at a predetermined time. (
For example, hold the temperature for 1 minute), then measure the outside temperature A' again using the outside temperature sensor, judge whether A'≧B as above, and if A'≧B, change the display B to A.
', and if A'≧B, the operation is repeated to determine whether the vehicle speed is higher than the predetermined vehicle speed.

If A'≧B and the vehicle speed is a predetermined vehicle speed or higher, check whether the vehicle has been continuously traveling at or above the predetermined speed for a predetermined time (for example, one minute), and if the predetermined time has not yet been reached, radiant heat is still being detected. It is determined that the influence has not been removed, and the display on the display unit is not changed, and the system waits for the next outside temperature measurement A' by the outside air temperature sensor.

Even if A'≧B, if the vehicle is continuously traveling for a predetermined time or more at a predetermined speed or higher, the outside air temperature sensor is generally cooled by the heat radiated by the traveling wind, and the effects of road radiant heat and engine radiant heat are removed. It is okay to judge that the temperature is present and change the display temperature on the display section 5.

However, if it takes a long time until the above-mentioned display switching conditions are met, that is, if the vehicle continues to drive slowly at a predetermined speed, for example, less than 20km8, the speed will be slightly over 20km8, and the vehicle will be driven for a predetermined period of time, for example, 1 minute. The measured value of outside temperature measurement A' immediately after the condition continues is often a much higher temperature value than the actual outside temperature, and when the display switching conditions are met, the outside temperature measurement A' is immediately changed. If the display B is switched to the measured value ', a situation arises in which the previous display value is switched to a higher value several times at once. It is extremely abnormal for a general outside temperature display to change the display to a value several degrees higher at any given time, giving the user a sense of anxiety and questioning the reliability of the outside temperature display device. This is extremely inconvenient as it may lead to

Therefore, in the present invention, when the display switching conditions that A'≧B and the vehicle has been traveling at a predetermined speed or higher for a predetermined period of time are satisfied as described above, the previously displayed temperature and the outside temperature measurement value at which the display should be switched are set. 1. If there is a difference between the two, that is, A'>B, the temperature increase display will change the display step by step at predetermined intervals, for example, 1°C per minute. A restriction means is provided.

For example, as shown in Figure 2, if the measured temperature immediately after the display switching condition was met is 3°C higher than the display temperature before the display switching condition was met, the display should be suddenly switched to that measured temperature as shown in the dotted line. The display is changed step by step, for example, by 1"0 per minute as shown by the solid line.

Generally, when the engine is started, the engine is cold, so there is no effect of engine heat on the outside temperature sensor, and in covered parking lots, there is little thermal effect from the sun or the ground, so when the ignition switch is turned on, the Outside temperature measurement A is often a relatively high outside temperature, and this is displayed on the display B so that subsequent outside temperature measurements A' may be affected by thermal influences such as engine temperature or road surface temperature. Use this as the basis for determining whether or not there is.

Also, for example, when restarting the engine before it has completely cooled down, or when starting in a parked state where it is strongly affected by direct heat from the sun, the first outside temperature measurement A may be due to the effects of engine heat or solar heat. Therefore, display B will be higher than the actual outside temperature, but once the engine is started and you start driving, the outside air temperature sensor will gradually be cooled down by the wind, and the subsequent outside temperature measurements A' will be the same as the initial display B. As the outside temperature becomes lower, the 1 displayed value is successively changed to a lower value, and soon the outside temperature is displayed almost correctly.

When the vehicle changes from a normal vehicle speed (for example, a vehicle speed of 20 km or more) to a stopped or extremely low-speed vehicle, the outside air temperature sensor section cannot be expected to be cooled by heat radiation due to the wind while the vehicle is running, and the outside air temperature sensor is affected by the heat radiated from the engine. Alternatively, the influence of radiant heat from the road surface becomes large and the outside temperature measured by the outside air temperature sensor rises considerably, resulting in A'>B, but in this case, the display switching condition is satisfied by the display switching condition determining means. It is determined that the display B is not changed, and the display B is not changed, and the previous display B is held as it is.

If the above display switching condition that the vehicle speed is above a predetermined vehicle speed and continues for a predetermined time is not met, for example, if you go from driving slowly on a congested road to driving at a predetermined vehicle speed (for example, 20 km/h) or more, the wind may The outside air temperature sensor starts to be cooled by heat radiation, and when this state continues for a predetermined period of time, it is determined that the display switching conditions have been met and the display is switched. Due to the effects of radiant heat from the engine, radiant heat from the road, etc., the temperature at the outside temperature sensor section has increased significantly compared to the correct outside temperature, and after that, the vehicle speed remains at a level slightly above 1 for a predetermined time, e.g. When the 1-minute line is displayed, the temperature of the outside temperature sensor section due to the wind while traveling is not sufficiently reduced, so the outside temperature measurement A' immediately after the display switching condition is satisfied in such a state is not the same as the previous display B. The value is often much higher than the approximately correct display value.

In the present invention, as described above, the measured value of outside temperature measurement A' after the display switching condition is satisfied is compared with the value of display B up to that point,
”>B, the display B is not suddenly switched to the measured value of A', and the temperature rise display limiting means operates to display a predetermined temperature (minimum display unit, e.g. 1°C) every minute for a predetermined period of time.
) The display B is switched step by step.

Therefore, if the value of outside temperature measurement A' immediately after the display switching condition is satisfied is, for example, 5°C higher than the displayed value of display B up to that point, the displayed value is increased by 1°C per minute. It will take 4 minutes for the measured value to be displayed, and during that time, the temperature of the outside air temperature sensor will be rapidly cooled down by the wind generated when the vehicle is traveling at a predetermined speed, for example 20 km or more, and will drop. The outside air temperature measurement A' measured by the outside air temperature sensor during the above four minutes also gradually decreases.

For example, if outside temperature measurement A' is performed every minute, the first outside temperature measurement A' immediately after the above display switching condition is satisfied.
The difference between '' and the previous display value of display B is 5°C, and the temperature rise display limiting means is activated to first change display B to a higher temperature display by 1"O, and then after 1 minute, display B is further increased. 1
When switching to a higher value by ℃, the next second outside temperature measurement A' will be a lower value than the first measurement, and in this way, the displayed value will increase by 1℃ per minute and at the same time. On the contrary, the measured value becomes lower every minute.

The increase in the display value of Display B stops when the display value and the measured value match, so even if the difference between the display value and the measured value is 5℃ as mentioned above, the display value will only increase by 2 to 3℃. If the display switching condition continues to be satisfied, the subsequent measured value of outside temperature measurement A' will be lower than the displayed value, and each time the displayed value of display B will be switched to a lower value, and the displayed value will be approximately correct. Return to temperature display.

By adopting the method of performing stepwise display switching using the temperature rise display limiting means after the display switching condition determining means determines whether or not display switching is possible as described in 7 above, it is possible to prevent the display from suddenly switching to an excessively high temperature. This not only eliminates inconveniences such as making the driver feel uneasy or doubting the reliability of the outside temperature display device as the display changes naturally, but also reduces the difference between the actual outside temperature and the displayed value to an extremely small range. It is something that can be kept within.

The display switching condition determining means, temperature rise display limiting means, etc. can be easily constructed by combining various conventionally known electronic circuits such as comparison circuits, switching circuits, and timer circuits.

Effects of the Invention As described above, according to the present invention, when driving slowly due to traffic congestion, etc., the outside temperature sensor section is greatly influenced by radiant heat from the engine, road surface, etc., and the outside temperature value measured by the outside temperature sensor is When it is determined that the display switching conditions are not satisfied and the display is not switched, and the vehicle continues to travel at a predetermined speed or higher for a predetermined period of time, it is determined that the display switching conditions are met, and the outside air temperature after the display switching conditions are met. If the measured value is higher than the previously displayed outside air temperature value, the displayed value is increased step by step by a predetermined temperature at predetermined time intervals, making it easier to switch the display after a long period of sluggish operation. The outside temperature display will no longer suddenly switch to an abnormally high value immediately after the conditions are met, and the outside temperature display will now switch naturally, and the difference between the actual outside temperature and the displayed outside temperature value will be minimized. In addition, highly reliable outside temperature display can be performed, and this can bring about great practical effects.

[Brief explanation of the drawing]

FIG. 1 is a flowchart showing an embodiment of the outside temperature display method according to the present invention, and FIG. 2 is a diagram showing an example of the outside temperature display switching mode by the temperature E increase display limiting means. From north

Claims (1)

[Claims] In an automotive outside temperature display device consisting of an outside air temperature sensor and a display section that displays the outside temperature as the outside temperature is measured by the outside air temperature sensor, the first outside temperature measurement immediately after engine startup is performed by displaying the measured value on the display section. After that, the measured value is compared with the value displayed on the display at that time, and if the measured value is lower than the displayed value, the display changes to that measured value. However, if the above measured value is higher than the displayed value at that time, it is determined whether the display switching condition that the vehicle continues to travel at a predetermined speed or higher for a predetermined period of time is met, and the display switching condition is met. If it is determined that the display switching conditions have not been met, the display will not be switched to the above measured value and the display will remain as it was. A method for displaying an outside air temperature for an automobile, characterized in that the display is changed stepwise by a predetermined temperature each time.