JPS6082439A - Residual fuel gauge for car - Google Patents

Abstract

PURPOSE:To indicate residual fuel accurately by indicating such level as the fuel consumption operated on the basis of fuel injection pulse is subtracted from previous level when the car speed is zero and the detected level of residual fuel is differed more than predetermined level from previous one. CONSTITUTION:When the car speed is not zero or under travelling, a switching circuit 7 will feed the operated residual level from a time averaging circuit 3 directly to driver circuit 4 and indicated on an indicator 5. When the car speed is zero, the switching circuit 7 will feed the operated residual level LB to a residual amount decision circuit 11 to be compared with previous level LA. If the difference is higher than the setting level, fuel consumption corresponding to the large count is subtracted to feed the difference to a driver circuit 4. The residual amount to be indicated in such a manner is an accurate level where the amount of fuel consumed during idling is subtracted from the amount prior to inclination of chassis.

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 Traditionally, foldable 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. 1 is a fuel sensor that outputs a gas signal in response to a change in the fuel level in the fuel tank E'; The A/D converter 2 converts the quantity signal into a digital value. A time averaging circuit 3 averages the A/D-converted remaining amount signal at regular time intervals and calculates an after-view 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 glazed fuel level gauge, when the vehicle is traveling on a slope or incline and the vehicle body is tilted or the vehicle body is suddenly braked, the fuel level changes significantly and the remaining level value differs from the actual remaining level. In order to prevent this, the fuel gauge is designed to correct the @ and display the remaining amount when the detected value of the remaining fuel amount at each fixed opening period deviates from the previous detected value by more than a predetermined value. It has been proposed (for example, Japanese Patent Laid-Open No. 56-53412). In this fuel gauge, a preset value, such as fuel consumption it 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 fuel level value detected at regular intervals with the above fuel gauge is corrected by a preset value each time. If the idling state continues for a long time, the difference between the actual fuel droplets*m and the setting value used for correction will accumulate, and the remaining fuel amount display value will differ from the actual remaining amount, causing the remaining amount display to become inaccurate. be.

(c) Object and Structure of the Invention The present invention has been made in view of the above points, and recently electronic fuel injection devices have been used to optimally control the amount of fuel supplied to the engine. This device monitors the point at which a fixed amount of fuel is supplied to the engine and consumed with each fuel injection pulse, and allows for an accurate display of the remaining amount of fuel while the vehicle is idling or parked on an incline for long periods of time. For this purpose, when the vehicle speed is zero and the detected value of the remaining fuel amount differs from the previous detected value of the remaining fuel amount by more than a predetermined value, the fuel injection pulse of the electronic fuel injection device is changed from the previous detected value of the remaining fuel amount. The system is configured to display a value obtained by subtracting the fuel consumption amount calculated based on the amount of fuel as the remaining fuel amount value.

) Example 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 adds a switching circuit 7 to the conventional example shown in FIG. 7, a heavy speed sensor 8 and a vehicle speed determination circuit 9, a remaining fuel amount storage circuit 10 that stores the remaining fuel amount displayed on the display 5,
A remaining amount determination circuit 11 that compares the previous fuel remaining amount stored in the remaining amount value storage circuit 10 with the current remaining amount calculation value and outputs a command according to the difference value, and an electronic fuel Injection device 1
2, the previous fuel remaining amount value sent from the remaining amount determination circuit 11, and the count value output from the pulse signal measuring circuit 13. The system further includes a remaining amount calculation circuit 14 that calculates the remaining amount of fuel from the fuel consumption it.

Next, the operation of displaying the remaining amount by the fuel remaining amount meter will be explained based on the flowcharts of FIGS. 2 and 3.

When the ignition switch 2 is turned on, the remaining amount signal output from the fuel sensor 1 is A/D converted by the A/D converter 2 (P-1), and in this state, the system enters a program interrupt wait state (P-2).

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

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).
When the speed is not zero, that is, when the vehicle is running, the calculated remaining amount value output from the switching circuit 7Fi and the time averaging circuit 3 is directly sent to the driver circuit 4 and displayed on the display 5.

On the other hand, if the speed is single speed or zero, the switching circuit 7
sends the calculated remaining amount value LB to the remaining amount determination circuit 11, where the remaining amount digit 1. is compared with the remaining fuel ht value LA of the 01st time recorded in circuit]0 (P-6).

As a result, both balances are -1. The absolute value of the difference between -1 value LIA + LB is a predetermined set value Lc (for example, 1t to 2t)
The fuel consumption it corresponding to the larger count value is subtracted, and the difference is sent to the driver circuit 4 and displayed on the display 5 (P-8). The remaining amount display value displayed in this manner is a value obtained by subtracting the amount of fuel consumed during idling over time from the remaining amount value before the vehicle body was 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 value calculated by the time averaging circuit 3 is directly sent to the driver circuit 4 for normal remaining amount display.

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

(E) Detailed Description of the Invention As described in detail, the present invention provides a system for displaying updated fuel remaining amount detected by a fuel sensor for a fixed period of time, in single speed or zero speed, When the detected value is greater than the previous fuel remaining amount detection value by a predetermined value, the fuel consumption calculated based on the fuel injection pulse of the m-child fuel injection device is subtracted from the previous fuel remaining amount detection value and displayed. For example, when a vehicle is parked in an idling state with one side of the vehicle resting on the pavement, or when the vehicle is parked idling on a slope for a long period of time, the accurate fuel level value that takes into account the actual fuel consumption during that time can be calculated. Can be displayed.

[Brief explanation of drawings]

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 display operation of the fuel level meter according to the present invention. This is the 70-chart. 1...Fuel sensor, 2...A/D converter, 3...
Time averaging circuit, 4... Driver circuit, 5... Display device, 6... Refresh circuit, 7... Switching circuit, 8...'fFL speed sensor, 9... Driving judgment circuit, DESCRIPTION OF SYMBOLS 10... Residual odd value captivation circuit, ]1... Remaining nine determination circuit, 12... ■Sub fuel ejection device, 13... Pulse peak number measuring circuit, 14... Remaining amount calculation circuit

Claims (1)

[Claims] In a fuel gauge that updates and displays the remaining fuel level detected by a fuel sensor at fixed time intervals, when the vehicle speed is zero and the detected remaining fuel level differs from the previous detected fuel level by more than a predetermined value, A vehicle characterized in that: 2. Display fljJ control means for displaying a value obtained by subtracting the fuel consumption calculated based on the fuel injection pulse of the electronic fuel injection device from the previous fuel remaining amount detection value as the remaining fuel amount value. fuel level gauge.