JPS6022528A - Device for detecting residual amount of fuel - Google Patents

Abstract

PURPOSE:To make it possible to conduct a highly reliable display of fuel residual amount, by providing such an arrangement that, if an eroor is appreciated between a fuel residual amount indicated by a fuel residual amount computing means and a fuel residual amount indicated by a fuel residual amount detecting means when the fuel residual amount reaches a predetermined value, the residual amount indicated by the fuel residual amount detecting means is direcly displayed. CONSTITUTION:During the residual amount of fuel is large so that no substantial affection is effected by detection errors, a computing circuit 1 receives a signal from a fuel injection control device 4 through a wavefrom shaping circuit 6, and computes a fuel residual amount which is displayed on a display 11 through a drive circuit 10. When the fuel residual amount is below a predetermined value and therefore, is liable to be subjected to the affection of detection errors, there is displayed a detection signal from a sender 2 for detecting the residual fuel amount, which is subjected to the affection of variations in the liquid level in a fuel tank but indicates a precise fuel residual amount.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel remaining amount detection means d in a vehicle.

A conventional device of this kind detects the remaining amount of fuel in the fuel tank based on a signal from a sender that detects the level of fuel in the fuel tank, and also controls the fuel injection control in fuel injection control 'A P7. Detect fuel exhaustion.

Initially (remaining amount of burnt fuel 14) according to the sender signal.

Alternatively, the amount of fuel remaining at each instant was calculated by subtracting the amount of fuel consumed from the remaining amount of fuel determined by calculation.

By doing this, even if the M-side bell in the Pi fuel tank fluctuates while the engine is running or the vehicle is running, the obtained fuel remaining amount data will increase midway through as the liquid level changes. regardless of fluid level fluctuations.

It is possible to obtain fuel remaining amount data that decreases sequentially as the engine is operated. In other words, the fuel remaining amount data detected by the sender signal is directly affected by the /II curve bell movement, but the fuel consumption data detected from the fuel injection signal is independent of the fuel level and is directly affected by the /II curve bell movement. Therefore, by subtracting the fuel consumption amount from the remaining fuel amount detected when there is no fluid level fluctuation, highly reliable remaining fuel amount data can be obtained.

However, the fuel consumption data has a problem in that an error occurs between the data and the actual fuel consumption due to fluctuations in fuel temperature and fuel injection pressure. If an error occurs in the fuel consumption data, an error will naturally occur in the calculated remaining amount of fuel.

In view of such conventional problems, an object of the present invention is to correct the remaining fuel amount detected by the sender when an error occurs in the remaining fuel amount calculated based on the fuel consumption amount. The purpose of this output is to obtain accurate fuel remaining amount data with few errors.

The structure of the present invention for achieving this object will be explained with reference to FIG.

The remaining fuel amount detection means detects the remaining amount of fuel in the fuel tank based on a signal from a sender that detects the liquid level of fuel in the fuel tank, and the fuel consumption M detection means detects the amount of fuel remaining in the fuel tank based on a signal from a sender that detects the liquid level of fuel in the fuel tank. Detect fuel consumption.

The remaining fuel amount calculating means subtracts the fuel consumption amount detected by the fuel consumption detection means from the remaining fuel amount initially detected by the remaining fuel amount detection means or the remaining fuel amount determined by calculation. to check the remaining fuel level.

Further, the remaining fuel amount determination means determines whether the remaining fuel amount determined by the remaining fuel I4 calculation means has reached a predetermined value,
ll Q difference supervisor monitoring means When the remaining fuel amount determining means determines that the remaining fuel amount has reached a predetermined value, the fuel amount = 4 remaining amount calculating means t The remaining fuel amount determined by this and the remaining fuel amount The remaining amount of fuel fuel 4 detected by the detection means is compared, and the presence or absence of an error is monitored based on whether the difference between the two falls within a predetermined range.

Then, when the error monitoring means determines that the residual fuel calculation means has reached the error limit, the residual fuel calculation means directly outputs the remaining fuel amount detected by the residual fuel amount detection means.

According to the present invention, when the remaining amount of fuel is small and the error is greatly affected, and an error is detected in the fuel consumption data, the error is set to 1.

Although it is affected by fluctuations in the liquid level in the fuel tank, since the remaining fuel amount is detected by the sender signal that accurately represents the remaining fuel level, accurate remaining fuel amount data can be obtained, and this data can be used to When displaying the remaining fuel amount, highly reliable 0 display can be performed.

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

FIG. 2 shows an electric circuit of one embodiment of the present invention.

The arithmetic circuit 1, which constitutes the main part of the present invention, inputs signals from various parts, calculates the remaining amount of fuel, and outputs a signal to the display 11 via the drive circuit IO in order to display this. The input signal of the circuit 1 is a signal from the A/L converter 3 and the waveform shaping circuit 6.7. It receives a signal from the computer, converts it into a digital signal, and outputs it. Moreover, the waveform shaping circuit 6
The waveform shaping circuit 7 shapes the waveform of the ignition signal from the ignition control device 5 and outputs it.

On the other hand, the drive circuit 10 receives a signal from the arithmetic circuit 1 representing the fuel 4 remaining hoe and converts it into a signal for driving the 9 indicator 11.

Note that the constant voltage circuit 12 is connected to a battery 8 serving as a power source via an ignition switch 9.

A constant voltage with no voltage fluctuation is applied to the arithmetic circuit 1, sender 2゜A/
IJ converter 3. Waveform shaping circuit 6.7 and drive circuit 1
0 respectively, and also.

The display power supply circuit 13 is connected to the battery 8 via the ignition switch 9 to generate voltage necessary for the display 11 and supply it to the display 11. Further, the fuel injection control device 4 and the ignition control device 5 are connected to a battery 8 via an ibunirasirin switch 9.

The arithmetic circuit 1 consists of a digital computer, and its program contents are as shown in the flowchart of FIG.

Next, one operation will be explained along this flowchart.

When the program is started, registers in the computer are cleared and initialization is performed in a step (not shown).Next, in step 20, the output of the sender 2 is read from the A/D converter 3, and in step 21
Then, the remaining fuel amount F1 is calculated based on the output 1 of the sender 2, and this is output to the drive circuit 10. Therefore, at this time, the remaining fuel amount F1 is displayed based on the signal from the drive circuit IO. Note that the processing in steps 20 and 21 corresponds to the remaining fuel amount detection means of the present invention.

Next, in step 22, depending on whether an ignition signal corresponding to the predetermined engine rotation speed (U) is generated from the waveform shaping circuit 7, if no ignition signal is generated from the control device 5 in which the engine is in an operating state, .

This is because no signal is output from the waveform shaping circuit 7 either.

Step 22 is negative, and the process waits at step 22 until the engine is in operation. When the engine is in operation and an ignition signal is supplied from the ignition control device 5 via the waveform shaping circuit 7.

An affirmative determination is made in step 22, and the process proceeds to step 23.

In step 23, the fuel injection signal supplied from the fuel injection control device 4 via the waveform shaping RI 6 is detected, and the pulse width τ of this signal and the period ``r'' of the fuel injection signal are read. It is determined whether the value t is larger than the value 1'max. In the process of step 24, the fuel injection signal is
This is to determine whether the fuel injection signal occurs within max or not, and to determine whether or not the fuel injection signal is being supplied from the fuel injection control device 4 via the waveform shaping circuit 6 in a positive waveform. Now, when the fuel injection signal is normally supplied and one cycle 'l' is smaller than rmax, an affirmative judgment is made in step 24 and the process proceeds to step 26, where there is a disconnection or poor welding in the middle of the line that supplies the fuel injection signal. When the fuel injection signal is not supplied normally, 7 cycles 'r is 'I' max
When 1 becomes larger than , step 24 is judged negative.

Proceed to step 25. In addition, 'rmax' is actually.

It is set to 5-10 minutes.

When the fuel injection signal is normally supplied and the process proceeds to step 26, in step 26, the pulse width τ of the fuel injection signal is
The amount of fuel oil IIl is calculated by calculating.

The processing of this step 26 and step 23 described above is 1
This corresponds to the fuel consumption detection means of the present invention. Next, in step 27, the fuel consumption 'Ij calculated in step 26 is calculated from the remaining fuel amount F calculated in step 21.
Subtract tya and find the remaining fuel ff1Fs at that time.

The remaining fuel amount data F determined here is the drive 111 road 1.
0 and displayed on the 9 display 11. Further, the remaining fuel amount data F determined in step 27 is stored in the RAM or register in the computer and used as data for the first calculation.

When the fuel injection signal is not normally supplied and the process proceeds to step 25, the signal from the sender 2 is read through the A/IJ converter 3 in step 25 as a counterweight in case of an abnormality, as in step 20.

Next, in step 28, the sender 2
Based on the signal from 'c fuel remaining 1? , is calculated,
It is output to the drive circuit IO. When the process of step 28 is completed, the process returns to step 22 and the process during this time is repeated.

As described above, when the remaining fuel MFt is calculated in step 27, it is determined in step 29 whether or not the remaining fuel 5lkFs has become less than a predetermined value Ft (for example, lO~15). reactor. Now calculated fuel - 1 remaining @F
If 1 is more than the predetermined value Ft, a negative determination is made in step 29 and the process returns to step 22 to repeat the process from step 22 onwards. If an affirmative determination is made, the process proceeds to step 30. Note that the process in step 29 corresponds to the remaining fuel amount 'I'lj determination means of the present invention.

In step 30, as in step 20.25, the signal from the toad sender 2 is read through the A/i) converter 3, and in step 31, the remaining amount of fuel*4 F4 is determined based on the signal read in step 30. Calculated. Note that the process of step 30.31 and the above-mentioned step 25.28
The process corresponds to the fuel residual amount detection means of the present invention, similar to the process of step 20.21. Next, in step 32, the difference between the fuel nFs calculated in step 27 and the remaining fuel amount F calculated in step 31, that is, the actual fuel remaining amount calculated using the fuel consumption amount, is determined. In step 33, the error E is j
y (it is determined whether it is within a certain range or not. As a result of accurate detection of fuel consumption, the error E is small and step 3
If J is determined to be affirmative, the process returns to step 221;
Since the remaining fuel amount becomes less than the predetermined 11 Ft, the remaining fuel amount is calculated in the same manner as in +J+>, and the fuel consumption is accurately calculated due to the influence of fluctuations in fuel temperature and fuel injection pressure. If the error E increases as a result of not being detected, and a negative determination is made in step 33, the process proceeds to step 34, where the remaining fuel amount signal output from the calculation circuit l to the drive circuit 10 is changed from F to F. Switch. In other words, we stop displaying the remaining fuel amount data F, which has a large detection error.
Although there are slight fluctuations, the fuel and 1 remaining amount data F is accurate.

to display it. Note that step 32.3
The process of step 3 corresponds to the error monitoring means of the present invention, and the process of steps 27 and 34 corresponds to the error monitoring means of the present invention. 4 corresponds to the remaining Jk calculation means.

In this way, while it is hardly affected by slight detection errors,
Step 9 While fuel residuals are relatively low, step 23.26
The remaining fuel amount is calculated using the fuel consumption amount detected by the fuel tank, and the remaining fuel amount data gradually decreases as the engine is operated without being affected by fluctuations in the liquid level in the fuel tank.
When the influence of the detection error becomes large, that is, when the fuel f4N becomes relatively small ζ, in step 32.33, it is determined that the remaining fuel amount data obtained using the fuel consumption amount has an error exceeding the allowable range. If there is an error exceeding the allowable range, the remaining fuel amount signal output to the 1 indicator 11 is determined in Step 30, which is affected by fluctuations in the liquid level in the fuel tank but has no error. The remaining amount of fuel detected at step 31 is determined. Therefore, a stable display without fluctuation can be performed until the remaining fuel amount becomes low, and then after the remaining fuel amount becomes low.

Accurate display can be performed.

One embodiment of the present invention has been described above.

The present invention is not limited to this example.

Various embodiments are included within the scope of the claims, some of which are listed above.

(1) Detection results for burnt4 remaining fences are not only displayed in one display.

It can also be used as an input signal to other control devices.

(2) The arithmetic circuit could be constructed from a dedicated hardware circuit instead of a computer.

(3) Subtract the fuel consumption amount from the remaining fuel amount data to get $4
When determining the residual amount, the remaining fuel amount initially detected by the sender signal is memorized, and the fuel consumption detected from time to time is accumulated. You can also calculate the accumulated fuel consumption by subtracting it from the remaining fuel amount.

(4) Fuel consumption 1! Detection of tft means that fuel t=
This can also be done by a signal from a flow meter installed in the dust supply path.

[Brief explanation of the drawing]

FIG. 1 is a claim correspondence diagram, FIG. 2 is a block diagram showing an electric circuit of one embodiment of the present invention, and FIG. 3 is a flowchart showing the contents of a computer program adopted in one embodiment. l...1 calculation circuit 2...sender 3...A/l) converter 4...fuel injection control device 5...γ/ignition control device 6 .7... Waveform shaping circuit 8... Battery 9... Ignition switch 10...
・Drive circuit 11... Display unit 12... Constant voltage circuit 13... Display power supply circuit Applicant Toyota Motor Corporation Figure 2 Figure 3

Claims (1)

[Claims] (1) Remaining fuel amount detection means detects the amount of fuel remaining in the fuel tank based on a signal from a sender that detects the liquid level of fuel in the fuel tank, and detects fuel consumption based on the amount of fuel supplied to the engine. The remaining fuel amount is determined by subtracting the fuel consumption amount detected by the fuel remaining amount calculation means from the remaining fuel amount initially detected by the fuel consumption star detection means and the fuel residual amount detection means, or from the remaining fuel amount determined by calculation. The remaining fuel amount detecting means includes a remaining fuel amount calculating means that determines whether the remaining fuel amount calculated by the remaining fuel amount calculating means has reached a predetermined value. By means of fuel I/! When it is determined that 4m has reached a predetermined value, the remaining fuel amount determined by the remaining fuel amount calculating means and the remaining fuel amount detected by the fuel amount detecting means are compared, and the difference between the two is determined to be a predetermined value. error monitoring means for monitoring the presence or absence of an error depending on whether or not the range is exceeded, and when the error is determined to be H by the +i difference monitoring means, the remaining fuel amount calculation means is discharged by the remaining fuel amount detection means. A fuel remaining amount detection device characterized by outputting the remaining fuel amount as is.