JPH0336694B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field The present invention relates to a fuel level meter for a vehicle that accurately displays the remaining fuel level when the vehicle is idling for a long time and is parked on an incline.

(b) Prior art Conventionally, needle-type fuel gauges have been used to display the amount of fuel remaining in a vehicle's fuel tank, but recently digital fuel gauges using electronic circuits have been used. It tends to be used. Figure 1 is a block diagram of a digital fuel level gauge, where 1 is a fuel sensor that outputs changes in the fuel level in the fuel tank in the form of an electrical signal, and the remaining level signal that is output from this fuel sensor 1. is converted into a digital value by the A/D converter 2. A time averaging circuit 3 averages the A/D-converted remaining amount signal at regular time intervals to calculate a remaining amount value. This remaining amount calculation value is displayed on the display 5 via the driver circuit 4, and the displayed value is updated by an update signal outputted from the refresh circuit 6 at regular time intervals.

With this type of fuel gauge, when the vehicle is traveling on a slope or incline, the vehicle body leans, or the vehicle body is suddenly braked, the fuel level changes significantly and the remaining fuel level value differs from the actual remaining amount. In order to prevent this, a fuel gauge has been proposed that corrects and displays the remaining amount when the detected value of the remaining fuel amount at regular intervals deviates from the previous detected value by more than a predetermined value. ing. (For example, JP-A-56-53412). In this fuel gauge, a preset value, such as the amount of fuel consumed in an idling state, is used to correct the display. In this way, even when the fuel level fluctuates due to tilting of the vehicle body or braking, the remaining amount is corrected and displayed, thereby preventing abnormal displays.

However, when the vehicle is parked in an idling state with one wheel resting on the pavement, the remaining fuel value detected at regular intervals by the fuel gauge is corrected each time by a preset value. If the idling state continues for a long time, the difference between the actual fuel consumption and the setting value used for correction will accumulate, causing the remaining fuel amount display value to differ from the actual remaining amount, causing the remaining amount display to become inaccurate. .

(c) Object and Structure of the Invention The present invention has been made in view of the above points.Recently, electronic fuel injection devices have been used to electronically optimally control the amount of fuel supplied to an engine, and this invention The device focuses on the fact that a fixed amount of fuel is supplied to and consumed by the engine with each fuel injection pulse, and is able to accurately display the remaining amount while the vehicle is idling for a long time or parked on an incline. For this purpose, there is provided a fuel sensor that detects the remaining fuel amount in the fuel tank, an averaging means that averages the signals from the sensor and outputs the averaged remaining fuel amount, and a vehicle running/stopping. a running/stopping determining means for determining whether the vehicle is stopped; and a storing means for storing a fuel remaining amount value outputted from the averaging means each time the running/stopping determining means determines that the vehicle has stopped.
means for calculating a fuel consumption amount based on a fuel injection pulse of an electronic fuel injection device; and subtracting the fuel consumption amount from a fuel remaining amount value stored in the storage means;
a subtracting means for outputting the subtracted remaining fuel amount value; and when the running/stopping determining means determines that the vehicle is running, inputting the remaining fuel amount value from the averaging means; If it is determined that the system is stopped, a switching means inputs the remaining fuel value from the subtracting means, and a display means displays the remaining fuel value output from the switching means. It is composed of

(d) Examples The present invention will be explained below based on the drawings.

FIG. 2 is a block diagram of one embodiment of a fuel level gauge according to the present invention, in which the same components as in FIG. 1 are designated by the same reference numerals. This embodiment is based on the conventional example shown in FIG. 1, and includes a switching circuit for switching whether to send the remaining amount calculation value from the time averaging circuit 3 as an averaging means directly to the driver circuit 4 or to the remaining amount determining circuit 11. 7, a running/stop determining means for controlling the switching of the switching circuit 7 as a switching means, a vehicle speed sensor 8 and a vehicle speed determining circuit 9, and a memory for storing the remaining fuel value displayed on the display 5 as a display means. Remaining amount value storage circuit 10 as a means
and a remaining amount determination circuit 11 that compares the previous fuel remaining amount value stored in the remaining amount value storage circuit 10 and the current remaining amount calculation value and outputs a command according to the value of the difference.
and a pulse signal measurement circuit 13 that counts the fuel injection pulses P output from the electronic fuel injection device 12 and constitutes a calculation means together with the electronic fuel injection device 12.
Remaining amount calculation as a subtraction means for calculating the remaining fuel amount from the previous fuel remaining amount value sent from the remaining amount determination circuit 11 and the fuel consumption amount calculated based on the count value output from the pulse signal measurement circuit 13 circuit 1
4 is further provided.

Next, the remaining amount display operation by the fuel remaining amount meter is performed in a second manner.
This will be explained based on the flowchart of FIG. 3 and FIG.

When the ignition switch is turned on, the remaining amount signal output from the fuel sensor 1 is sent to the A/D converter 2.
A/D conversion is performed (P-1), and in this state, the program enters a wait state for an interrupt (P-2).

When there is an interrupt command, the remaining amount is calculated as follows (P-3). That is, A/D converter 2
The remaining amount signal converted into a digital signal is averaged by a time averaging circuit 3, updated as a remaining amount value by a refresh circuit 6 at fixed time intervals, and sent to a switching circuit 7.

Now, based on the vehicle speed signal from the vehicle speed sensor 8, the vehicle speed determination circuit 9 determines whether the vehicle speed is zero or not (P-4), and when the vehicle speed is not zero, that is, when the vehicle is running, the switching circuit 7 performs time averaging. The calculated remaining amount value output from the circuit 3 is directly sent to the driver circuit 4 and displayed on the display 5.

On the other hand, if the vehicle speed is zero, the switching circuit 7 sends the calculated remaining fuel amount L _B to the remaining fuel amount determination circuit 11, where it calculates the previous fuel remaining amount value L stored in the remaining amount storage circuit 10. Compare with _A (P-6). As a result, the fuel consumption amount corresponding to the count value where the absolute value of the difference between both remaining fuel values L _A and L _B is larger than a predetermined set value L _C (for example, 1l to 2l) is subtracted, and the difference is calculated by the driver circuit. 4 and display it on display 5 (P
-8). The remaining amount display value displayed in this manner is a value obtained by subtracting the fuel consumed during idling over time from the remaining amount value before the vehicle body tilted, so it is an accurate remaining amount value.

After that, when the vehicle starts running and the vehicle speed becomes non-zero (P-4), the switching circuit 8 is switched and the remaining amount calculated by the time averaging circuit 3 is sent directly to the driver circuit 4, and the normal remaining amount is displayed. Let's do it.

In the above embodiment, the switching of the remaining amount display was realized by the circuit configuration, but it is of course possible to perform the switching by program processing using a microcomputer.

(e) Effects of the Invention As explained above, the present invention detects the remaining fuel amount in the fuel tank in a fuel remaining amount meter that updates and displays the remaining fuel amount detected at fixed time intervals by a fuel sensor. A fuel sensor, an averaging means for averaging signals from the sensor and outputting an averaged remaining fuel amount value, a running/stopping judgment means for judging whether the vehicle speed is running or stopping, and a running/stopping judgment means for determining whether the vehicle is running or not. storage means for storing the remaining fuel amount value output from the averaging means each time it is determined that the fuel cell is stopped;
means for calculating a fuel consumption amount based on a fuel injection pulse of an electronic fuel injection device; and subtracting the fuel consumption amount from a fuel remaining amount value stored in the storage means;
a subtracting means for outputting the subtracted remaining fuel amount value; and when the running/stopping determining means determines that the vehicle is running, inputting the remaining fuel amount value from the averaging means; If it is determined that the system is stopped, a switching means inputs the remaining fuel value from the subtracting means, and a display means displays the remaining fuel value output from the switching means. For example, if the vehicle is parked idling with one side on the pavement or parked idling on a slope for a long period of time, an accurate fuel level value will be displayed that takes into account the actual fuel consumption during that time. .

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a conventional fuel level meter, FIG. 2 is a block diagram of an embodiment of the fuel level meter according to the present invention, and FIG. 3 is a block diagram of the display operation of the fuel level meter according to the present invention. It is a flowchart. 1...Fuel sensor, 2...A/D converter, 3...
...Time averaging circuit, 4...Driver circuit, 5...
Display, 6...Refresh circuit, 7...Switching circuit, 8...Vehicle speed sensor, 9...Driving judgment circuit, 10...Remaining amount value storage circuit, 11...Remaining amount judgment circuit, 12...Electronic fuel Injection device, 13...Pulse signal measurement circuit, 14...Remaining amount calculation circuit.

Claims (1)

[Scope of Claims] 1. A fuel sensor that detects the remaining amount of fuel in the fuel tank; Averaging means that averages the signals from the fuel sensor and outputs the averaged remaining amount of fuel; and When the vehicle is running. A running/stopping determining means for determining whether the vehicle is stopped; a storage means for storing a fuel remaining amount value output from the averaging means each time the traveling/stopping determining means determines that the vehicle has stopped; and an electronic fuel injection device. means for calculating a fuel consumption amount based on the fuel injection pulse of the fuel injection pulse; a subtraction means for subtracting the fuel consumption amount from the fuel remaining amount value stored in the storage means and outputting the subtracted fuel remaining amount value; If the running/stopping determining means determines that the vehicle is running, input the remaining fuel level value from the averaging means, and if the running/stopping means determines that the vehicle is stopped, the fuel amount is subtracted. A fuel remaining amount meter for a vehicle, comprising: a switching means for inputting a remaining fuel amount value from the switching means; and a display means for displaying a remaining fuel amount value output from the switching means.