JPS6344176B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a remaining fuel amount detection device, and particularly to one that reduces errors in remaining fuel in an automobile as much as possible.

In recent years, cars with a function to display the remaining amount of fuel such as gasoline have appeared. The circuit that realizes this remaining fuel display function integrates the used fuel value based on the engine's injection amount signal (τ signal), and subtracts this integrated value from the fuel tank capacity to calculate the remaining fuel value. It is now displayed as follows. In this case, the starting point for integrating the fuel usage value is the point at which the driver presses the operation switch when the fuel tank is filled to the brim with fuel.

However, in the case of such a configuration, if the fuel is not refilled to the full capacity of the fuel tank, if the fuel is removed, or if the operation switch is not pressed even after the fuel tank is filled to the full (hereinafter referred to as full tank), Accurate remaining fuel may not be displayed.

Furthermore, since the subtraction method is adopted from when the tank is full, replenishment always requires the driver to replenish the tank to full and turn on the operation switch each time.

Furthermore, since the system integrates the engine's ejection amount signal, errors are accumulated and the error between the actual remaining amount and the display increases as the count increases.

Therefore, in view of the above-mentioned drawbacks, the present invention is capable of displaying the correct remaining amount value even if you forget to press the operating switch when refilling or draining fuel, and there is no need to turn on the operating switch each time. It is an object of the present invention to provide a fuel remaining amount detection device that corrects the accumulation of errors without needing to do so.

In order to achieve this purpose, the present invention sets the fuel value to the maximum value by pressing an operation switch when the fuel tank is filled to the full with fuel, and subtracts the used fuel value based on the engine injection amount signal of the automobile from this maximum fuel value. Then, the remaining fuel value resulting from this subtraction is compared with the detected fuel value corresponding to the remaining fuel signal from the fuel sender, and if the difference resulting from this comparison is greater than a predetermined value, the detected fuel value is given priority and the normal remaining fuel value is set. The feature is that the above subtraction is further performed as follows.

Here, embodiments of the present invention will be described with reference to the drawings. A signal for driving a fuel injector 2 from an engine controller 1 that controls an engine of an automobile is input to an injector open time measuring circuit 3. This injector open time measurement circuit 3
The signal (engine injection amount signal) corresponds to the amount of fuel injected from the fuel injector 2. The signal from the injector open time measuring circuit 3 is calculated into the consumed (used) fuel value by the consumed fuel calculation circuit 4, and every time a certain amount, for example 0.1, is consumed (calculated), a signal C is outputted to the remaining fuel storage circuit 5. . A signal from the power supply voltage measurement circuit 6 is also input to the fuel consumption calculation circuit 4, and this signal receives the injector drive signal of the fuel injector 2, which is affected by the power supply voltage, and also the engine injection amount signal from the injector open time measurement circuit 3. This is corrected by changing the coefficient.

On the other hand, in the remaining fuel storage circuit 5, the operating switch 7s
When turning on, the stored value is changed to the maximum fuel value, for example 65.
You can replace it with the appropriate value. That is, by turning on the operation switch 7s when the fuel tank is full, the maximum fuel value is reached. Here, each time the signal C from the consumed fuel calculation circuit 4 reaches the remaining fuel storage circuit 5, a predetermined amount is subtracted, for example, by an amount corresponding to 0.1.

A signal detecting the actual amount of fuel in the fuel tank is output from the fuel sender 7 to an averaging circuit 8. This averaging circuit 8 is the fuel injector 7
The remaining fuel signal over a certain period of time is averaged to remove fluctuations caused by vibrations in the liquid level, centrifugal force, and vehicle tilt. The signal from the averaging circuit 8 is converted by the A/D converter 9 and then output as a digital signal to the comparator circuit 10 and the remaining fuel storage circuit 5.

The comparison circuit 10 compares the subtracted value based on the signal based on the fuel injector 2 stored in the remaining fuel storage circuit 5, that is, the remaining fuel amount value, and the fuel sender 7.
The detected fuel value based on the remaining fuel signal is compared to find the difference between these values. When this difference is greater than a certain value, signal A is output from the comparator circuit 10 to the remaining fuel storage circuit 5, and from this output, the remaining fuel storage circuit 5 takes in the averaged and digitized remaining fuel signal B, indicating the current normal state. Rewrite and store as the remaining amount value.

Subsequent subtraction by signal C is performed with respect to this normal remaining amount value.

In this way, by comparing the subtraction using the highly accurate engine injection amount signal from the fuel injector 2 and the remaining fuel signal from the fuel sender 7, which is not as accurate as this injection amount signal, but is approximately accurate, It is now possible to correct the accumulation of errors, refueling, and sampling.

As explained above in the embodiments, according to the present invention, fuel can be measured accurately using the injection amount signal from the fuel injector, and fuel can be directly measured almost accurately using the remaining fuel signal from the fuel sender. , even when refueling or removing fuel, it is possible to accurately display the remaining fuel without pressing the operating switch when the tank is full, and it is possible to display the remaining fuel without turning on the operating switch when the tank is full. Even if the cumulative error becomes large, it can be corrected, making it extremely useful for automobile fuel level display devices and driving information calculation and display devices that use the remaining fuel level to calculate and display drivable distance and expected gas shortage time. be.

[Brief explanation of the drawing]

The figure is a circuit configuration diagram showing an embodiment of the remaining fuel amount detection device according to the present invention. In the drawing, 1 is an engine control controller, 2 is a fuel injector, 3 is an injector open time measurement circuit, 4 is a fuel consumption calculation circuit, 5 is a remaining fuel storage circuit, 6 is a power supply voltage measurement circuit, 7 is a fuel sender, 8 is an averaging circuit, 9 is an A/D converter, 10
is a comparison circuit.

Claims (1)

[Claims] 1. When the fuel tank is fully filled with fuel, press the operating switch to set the fuel value to the maximum, subtract the fuel used value based on the automobile engine injection amount signal from this maximum fuel value, and perform this subtraction. The resulting fuel remaining amount value is compared with the detected fuel value corresponding to the remaining fuel signal from the fuel sender, and if the difference resulting from this comparison is greater than a predetermined value, the detected fuel amount value is given priority and the above subtraction is performed as the normal remaining amount value. Furthermore, there is a remaining fuel amount detection device. 2. The remaining fuel amount detection device according to claim 1, wherein the detected fuel value is obtained by averaging the remaining fuel signal over a predetermined period of time.