JPH11326011A - Fuel residual amount detector for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel residual amount detector for a vehicle, capable of simply, cheaply, accurately detecting the residual amount of fuel by a conventional measurement means even if a saddle type fuel tank is used. SOLUTION: A control device 23 lights a fuel residual amount warning lamp 26, when an average value of a fuel residual amount for one minute, obtained from a combined resistance value of a fuel sender 20a installed in a main tank 1a of a fuel tank 1 and a fuel sender 20b installed in a subtank 1b, of 10 liters or less continues ten times or for 10 km. When the continuity is interrupted even once, it is judged that the error of a run state or of measurement is included, and the judgement whether the average value continues ten times or for 10 km is carried out again.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel level detecting device for a vehicle, which emits a warning light to a driver to notify the driver when the fuel level is low.

[0002]

2. Description of the Related Art Conventionally, in a vehicle such as an automobile, when a fuel level becomes low, a fuel level warning light provided on a combination meter or the like of an instrument panel is lit to notify a driver. Has become.

[0003] As a measuring means for measuring the remaining amount of fuel in the fuel tank, for example, a variable resistance in the fuel tank is provided with a float, and the remaining fuel amount is determined from the liquid level in the fuel tank. An inexpensive fuel sender is used.

However, since the liquid level in the fuel tank fluctuates greatly due to the influence of the vibration and attitude of the vehicle, the amount of fuel measured instantaneously may include many errors due to these factors. Therefore, it is common practice to use the average value of the instantaneous remaining fuel amount for a predetermined time as the remaining fuel amount.

Further, in order to accurately measure the remaining amount of fuel, for example, in Japanese Patent Publication No. 63-44176, when the fuel tank is filled with fuel, an operation switch is pressed to set the fuel value to a maximum. Subtract the used fuel value from the vehicle engine emission signal from the maximum fuel value, and compare the subtracted fuel remaining value with the detected fuel value corresponding to the remaining fuel signal from the fuel sender (averaged over a predetermined time). It is disclosed that the remaining fuel amount is measured by performing the measurement.

[0006]

However, it is difficult for a measuring means such as a fuel sender to accurately measure the fuel tank to around 0 liter. Therefore, the fuel remaining in the fuel tank is still warned to the driver. Despite being at a level that does not need to be performed, the remaining fuel level may be measured low and the fuel level warning light may be turned on.

In particular, in the case of a so-called saddle type fuel tank in which the center of the fuel tank is concave and formed of a main tank and a sub-tank due to escape of a propeller shaft or the like, the remaining fuel amount is small. In the area, the fuel remaining amount is generally measured using two measuring means for the main tank and the sub tank, and the total value is generally used as the fuel amount. If the measuring means cannot sense up to 0 liter, When the fuel is returned from the main tank to the sub-tank, which has been almost 0 liters, such as when the vehicle turns, the decrease in the remaining fuel in the main tank can be measured, but the remaining fuel in the sub-tank can be measured. Since the increase cannot be measured, there is a possibility that the fuel remaining amount is measured as if the remaining fuel amount has significantly decreased and the fuel remaining amount warning light is turned on.

In order to solve this problem, the shape of the fuel tank, the number and mounting position of the measuring means are devised, and a measuring means using a thermistor or the like capable of relatively accurately measuring to around 0 liters is used. However, it is very complicated and expensive.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances. Even in the case of a saddle-type fuel tank, a vehicle capable of accurately detecting the remaining fuel amount simply, inexpensively, and using conventional measuring means. It is an object of the present invention to provide a fuel remaining amount detecting device.

[0010]

According to a first aspect of the present invention, there is provided an apparatus for detecting a remaining amount of fuel in a vehicle, comprising: a fuel remaining amount measuring means for measuring a remaining amount of fuel in a fuel tank; Lower limit determining means for determining whether the remaining amount falls below a preset reference value; continuity determining means for determining that the remaining fuel amount falls below the reference value under predetermined conditions; and continuity determining means And output means for outputting that the actual remaining amount of fuel in the fuel tank falls below the reference value when it is determined that the fuel cell is continuous.

According to a first aspect of the present invention, there is provided an apparatus for detecting a remaining amount of fuel in a vehicle, wherein the remaining fuel amount is measured by a remaining fuel amount measuring means, and the remaining fuel amount is lower than a predetermined reference value by a lower limit determining means. It is determined by the continuity determining means that the fuel remaining amount is lower than the reference value under the preset condition. The output means outputs that the actual remaining fuel amount in the fuel tank falls below the reference value when the continuity determining means determines that the fuel cells are continuous.

According to a second aspect of the present invention, there is provided an apparatus for detecting a remaining fuel amount of a vehicle according to the first aspect of the present invention, wherein the continuity judging means comprises: Since it is determined that the fuel remaining is continued when the remaining fuel level falls below the reference value, the fuel is consumed at a high speed even if the time is short, and the fuel remaining level falls below the reference value. Is reliably output from the output means.

[0013] Further, according to a third aspect of the present invention, in the vehicle remaining fuel detecting device according to the first aspect of the present invention, the continuity judging means includes at least a predetermined time and a predetermined number of times. On the other hand, it is determined that the fuel remaining is continued when the remaining fuel amount is below the reference value.For example, even if the traveling distance is short, idling, climbing a hill, and traveling in a traffic jam may consume fuel. When the remaining fuel amount is lower than the reference value, the output is reliably output from the output means.

According to a fourth aspect of the present invention, there is provided an apparatus for detecting a remaining fuel amount of a vehicle according to the first aspect of the present invention, wherein the continuity determining means includes a predetermined traveling distance and a predetermined traveling distance. During at least one of the set time and the number of times, the fuel remaining amount is determined to be continuous when it continues to fall below the reference value. If the fuel is consumed and the remaining fuel amount is below the reference value, or even if the traveling distance is short, idling, climbing a hill, and congestion traveling consume fuel and the remaining fuel amount is below the reference value. In this case, the data is reliably output from the output means.

According to a fifth aspect of the present invention, there is provided a vehicle fuel remaining amount detecting device according to the present invention, wherein the vehicle remaining fuel amount detecting device is provided with a replenishment determining means for determining fuel supply. The output means outputs that the actual remaining amount of fuel in the fuel tank is lower than the reference value until refueling is performed when the continuity determination means determines that the fuel cell is continuous. In addition, it is possible to prevent the output from the output unit from being unstable due to the change in the vehicle attitude changing the fuel level in the fuel tank.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 show an embodiment of the present invention. FIG. 1 is an explanatory diagram of an overall outline of a fuel remaining amount detecting device,
FIG. 2 is a flowchart of a fuel remaining amount detection program executed immediately after the ignition is turned on, and FIG. 3 is a flowchart of a normal fuel remaining amount detection program.

In FIG. 1, reference numeral 1 denotes a fuel tank of a four-wheel drive vehicle, and this fuel tank 1 is, for example, disposed and fixed below a rear seat (not shown). In order to avoid a differential (not shown) provided at the lower portion of the fuel tank 1, the fuel tank 1 has a substantially central bottom formed in a concave shape, and has a main tank (a tank on the right side in the figure) 1a and a sub tank 1a. (Left tank in the figure) 1b-2
This is a so-called saddle type fuel tank divided into two tanks.

The main tank 1a of the fuel tank 1 is provided with a fuel pump 2 for supplying and circulating fuel to the engine side and a jet pump 3 for transferring fuel from the sub tank 1b to the main tank 1a side.

For this reason, when the liquid level of the fuel is lowered and the main tank 1a and the sub tank 1b are separated from each other by the convex portion substantially at the center of the bottom of the fuel tank 1, the fuel in the sub tank 1b is supplied to the jet pump 3 Therefore, the fuel is transferred to the main tank 1a through the jet pump filter 4 and the transfer line 5, so that the fuel first drops from the liquid level of the fuel in the sub tank 1b.

Further, in the main tank 1a, the fuel sucked by the fuel pump 2 through the fuel pump filter 6 is injected from the fuel injector 10 through the fuel filter 8 and the fuel damper 9 of the delivery line 7 to the engine side, or The fuel is returned from the pressure regulator 11 through the return line 12 into the fuel tank 1.

Further, reference numeral 13 in the drawing denotes a canister constituting a fuel evaporative gas emission prevention system. When the evaporative gas generated in the fuel tank 1 reaches a set pressure via a fuel separator 14, the two-way valve 15 is pushed. Open,
It flows into the canister 13 and is stored. When the throttle valve 16 is opened during operation of the engine, the check valve 18 of the purge line 17 is opened by the negative pressure of the throttle.
Is opened, and the gas stored in the canister 13 is sucked into the injection body together with the outside air sucked from below the canister 13 and burned. This suppresses the emission of HC into the atmosphere. When the negative pressure in the fuel tank 1 exceeds the set pressure, the air entering from the lower part of the canister 13 is guided to the fuel tank 1 by the action of the two-way valve 15 so that the tank internal pressure is always kept in a predetermined range. The deformation of the tank 1 is prevented.

The main tank 1a and the sub tank 1b
Means that the floats 22a, 2b are connected to the variable resistors 21a, 21b.
2b and the main tank 1a and the sub tank 1
The variable resistances 21a and 21
a fuel sender 20 configured as shown by b
a and 20b are provided.
0a and 20b are electrically connected in series, and the combined resistance of the resistance value of the fuel sender 20a and the resistance value of the fuel sender 20b is mutually connected via a bus line to the CPU, ROM, RAM, input port, and output port. Control device 23 including a connected microcomputer and the like
Can be measured.

In order to display the combined resistance value as the remaining fuel amount in the fuel tank 1, a fuel remaining amount indicator 24 is connected in parallel between the battery 25 and the connection line of the combined resistance value to the controller 23. Is connected, and the fuel level indicator 24 is connected to the controller 23.

A mileage signal displayed by an odometer arranged in a speedometer portion (not shown) of the combination meter is electrically converted into the control device 23 or input as it is. ing.

Further, the control device 23 is connected to a fuel level warning light 26 which is provided in the speedometer portion of the combination meter and warns the driver that the fuel level is low.

Next, a fuel remaining amount detection program executed by the control unit 23 will be described with reference to the flowcharts of FIGS. The flowchart shown in FIG. 2 is executed immediately after the ignition is turned on, and thereafter, the flowchart shown in FIG. 3 is executed at predetermined time intervals.

First, immediately after the ignition is turned on (FIG. 2), at step (hereinafter abbreviated as "S") 101, the necessary R
After the initialization of the AM, the process proceeds to S102, and immediately after the ignition is turned on, the average value Fa1 of the remaining fuel amount for one second is read.

That is, the fuel senders 20a and 20b
The average value Fa1 of the combined resistance value for a predetermined short time (for example, one second as described above) is not used as the value indicating the remaining fuel amount, instead of using the combined resistance value at the moment when the data is read from By doing so, a fuel residual value with as little error as possible is obtained. The reason why the “short time” is set is that the present process is a process immediately after the ignition is turned on, and thus loses its meaning in a long time.

Then, the program proceeds to S103, in which it is determined whether or not there is an output to light the fuel remaining amount warning lamp 26 before the ignition is turned off. And the fuel level warning light 2
If there is an output to light up for the fuel tank 6, the process proceeds to S104, where the average fuel remaining amount Fa1 for one second is set to a predetermined level, and the fuel level drops and the main tank 1a and the sub tank 1b Then, it is determined whether or not the sum of the maximum remaining fuel amount stored in the main tank 1a when the fuel is separated and the minimum detection remaining amount of the fuel sender 20b of the sub tank 1b, for example, 12 liters or more. This means that, for example, the fuel level warning lamp 26 is turned on when the fuel level is 10 liters or less.
The maximum remaining fuel in the main tank 1a when separated is 1
0 liter, fuel sender 20b in sub tank 1b
If the minimum detection remaining amount is 2 liters, the fuel remaining amount warning light 26 is turned on before the ignition is turned off, and the error that the minimum detection remaining amount of the fuel sender 20b of the sub tank 1b is 2 liters is considered. Even if it is determined that the amount is less than 12 liters, it is a process of determining whether the amount has increased to 12 liters or more or remains as it is less than 12 liters.

As a result of S104, when the average fuel remaining value Fa1 for one second is 12 liters or more and the fuel has increased and it can be determined that refueling has been performed (if Fa1 ≧ 12 L (liter)), , And proceeds to S105, where
The counter C10 of 0 L or less is cleared (C10 = 0), and the running distance counter L described later is cleared (L = 0).
Then, the fuel remaining amount warning light 26 is turned off and the ignition O
The processing immediately after N ends.

As a result of S104, when the average fuel remaining value Fa1 for one second remains less than 12 liters (if Fa1 <12L), the fuel remaining amount warning light 2
6 is kept lit, and the process immediately after the ignition is turned on ends.

On the other hand, in step S103, the ignition O
Before the FF, there is no output to the fuel level warning light 26,
When it is determined that the light is turned off, the process proceeds to S106, where the average fuel remaining amount Fa1 for one second is set to a predetermined low value,
For example, it is determined whether or not the fuel is 4 liters or less, and it is determined whether or not the fuel has decreased after the vehicle has stopped.

If it is determined in S106 that the average fuel remaining value Fa1 for one second is 4 liters or less (Fa1 ≦ 4L) and it can be determined that the fuel has decreased after the vehicle has stopped, S1 is used.
07, the fuel level warning lamp 26 is turned on, while 1
The average fuel remaining amount Fa1 per second is more than 4 liters (Fa1
> 4L), when it can be determined that the fuel does not decrease so much after stopping the vehicle, the ignition is turned on as it is, that is, the fuel remaining amount warning lamp 26 is kept off.
The immediately following process ends.

Next, normal processing executed at predetermined time intervals after the above-described processing immediately after the ignition is turned on will be described with reference to the flowchart of FIG.

First, in step S201, the travel distance δL since the previous reading is read, and in step S202, the one minute fuel remaining average value Fa60 is read. That is, in the normal processing, the combined resistance value (for example, one minute) longer than the one-second average fuel amount average value Fa1 used in the processing immediately after the ignition is turned ON and more sufficiently following the control, for more accuracy. Average value of F
Let a60 be a value indicating the remaining fuel level.

Then, the program proceeds to S203, in which it is determined whether or not the fuel level warning lamp 26 is currently lit, and whether or not the fuel level warning lamp 26 is lit is turned on. If so, the process proceeds to S204, in which it is determined whether the one-minute average fuel remaining amount Fa60 has increased to 12 liters or more, or remains less than 12 liters. Note that this determination is based on the refueling determination process (S1 described above) immediately after the ignition is turned on.
04).

Then, as a result of S204, when the average fuel remaining value Fa60 for one minute is 12 liters or more, it can be determined that the fuel has increased and the fuel has been replenished (Fa60).
If ≧ 12L), the process proceeds to S205, where the counter C10 for continuous 10L or less is cleared (C10 = 0), the running distance counter L is cleared (L = 0), and the fuel remaining amount warning light 2
No. 6 is turned off, and the normal processing ends (corresponding to S105).

As a result of the above S204, when the average fuel remaining amount Fa60 for one minute remains less than 12 liters (when Fa60 <12L), the fuel remaining amount warning lamp 26 is kept lit as it is, The process ends.

Since S203 to S205 are provided as described above, when the fuel remaining amount warning light 26 is turned on, the fuel remaining amount warning light 26 remains lit until fuel is supplied.

On the other hand, if it is determined in step S203 that the fuel remaining amount warning lamp 26 is currently turned off, the process proceeds to step S206, where the one minute fuel remaining amount average value Fa60 is set in advance. Determine whether it is a low value, for example, 4 liters or less,
It is determined whether the fuel has decreased further.

In step S206, if the average fuel remaining amount Fa60 per minute is 4 liters or less (Fa60 ≦ 4L),
If it is determined that the fuel has further decreased, the process proceeds to S213, in which the fuel remaining amount warning lamp 26 is turned on to end the normal processing, while the average fuel remaining value Fa60 per minute is more than 4 liters (Fa60> 4L). If it can be determined that the fuel does not decrease so much, the process proceeds to S207.

In S207, it is determined whether or not the one-minute average fuel remaining amount Fa60 is equal to or less than a preset warning target value, that is, 10 liters or less, and the one-minute average remaining fuel amount Fa60 is determined. More than 10 liters (Fa60> 10
In the case of L), the process proceeds to S208, where the counter C10 for continuous 10 L or less is cleared (C10 = 0), the running distance counter L is cleared (L = 0), and the fuel remaining amount warning lamp 26 remains off, and the normal The process ends.

In step S207, the average fuel remaining amount Fa60 for one minute is equal to or less than 10 liters (Fa60 ≦ 10 L).
If it is determined that it is in the warning stage, the process proceeds to S209, and the counter C10 of 10 L or less is counted up (C
10 = C10 + 1), and then proceeds to S210.

In S210, it is determined whether or not the counter C10 of 10 L or less has reached 10 times or more (the number of times set in advance). If the counter C10 of 10 L or less has reached 10 or more, the flow proceeds to S213. Fuel level warning light 26
Is turned on, and the normal processing is terminated. On the other hand, if the counter C10 does not reach 10 times below 10L, the process proceeds to S211.

In step S211, the travel distance counter L is updated (L = L + δL), and the flow advances to step S212 to determine whether or not the travel distance counter L has reached 10 km (a preset distance).

If the result of the determination in S212 shows that the running distance counter L has reached 10 km, the routine proceeds to S213, in which the fuel level warning lamp 26 is turned on and the normal processing is terminated. If the distance does not reach 10 km, the normal processing is terminated while the remaining fuel amount warning light 26 remains off.

That is, the counter C which is equal to or less than the continuous 10 L
Reference numeral 10 indicates how many times the one-minute average fuel remaining amount Fa60 is equal to or less than 10 liters. The running distance counter L indicates the one-minute average remaining fuel amount Fa6.
0 is less than 10 liters, which counts how many kilometers the vehicle continues. As described above, the fuel remaining amount warning lamp 26 is turned on when 10 consecutive times or 10 km consecutively, and even once in the middle of 10 liters. When more results are obtained, the counter C10 for continuous 10 L or less and the mileage counter L are reset.

As a result, in the case of running at high speed and consuming a large amount of fuel in a short time, it is determined by the running distance counter L that the running has been continued. On the other hand, the running distance is short due to traffic jam, climbing a slope, or idling for a long time. When a large amount of fuel has been consumed, it is determined that the fuel has continued by the counter C10 of 10 L or less, and the fuel remaining amount warning lamp 26 is reliably turned on.

[0049]

As described above, according to the present invention,
Fuel remaining amount measuring means for measuring the remaining amount of fuel in the fuel tank;
Lower limit determining means for determining whether the remaining fuel amount is lower than a preset reference value; continuity determining means for determining that the remaining fuel amount is lower than the reference value to be continued under a predetermined condition; Output means for outputting that the actual remaining amount of fuel in the fuel tank falls below the reference value when the determination means determines that the fuel tank is continuous. Using the measuring means, it is possible to detect the remaining fuel amount easily and inexpensively and accurately.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an overall outline of a fuel remaining amount detecting device.

FIG. 2 is a flowchart of a fuel remaining amount detection program executed immediately after an ignition is turned on.

FIG. 3 is a flowchart of a normal fuel remaining amount detection program;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fuel tank 1a Main tank 1b Sub tank 2 Fuel pump 3 Jet pump 20a, 20b Fuel sender 23 Control device 26 Fuel remaining amount warning light

Claims (5)

[Claims] 1. A fuel remaining amount measuring means for measuring a remaining amount of fuel in a fuel tank, a lower limit determining means for determining whether the remaining amount of fuel is below a preset reference value, A continuity determining means for determining that the decrease is continuous under a preset condition, and outputting that the actual remaining amount of fuel in the fuel tank is lower than the reference value when the continuity determining means determines that the fuel is continuous. An apparatus for detecting a remaining fuel amount of a vehicle, comprising: an output unit. 2. The vehicle according to claim 1, wherein the continuity determining means determines that the fuel is continuous when the remaining amount of fuel continues to fall below the reference value during a preset traveling distance. Fuel level detection device. 3. The continuity judging means judges that continuation is continued when the remaining amount of fuel continues to fall below the reference value for at least one of a preset time and a predetermined number of times. 2. The device for detecting the remaining fuel amount of a vehicle according to claim 1. 4. The continuity judging means, when the fuel remaining amount continues to be lower than the reference value for at least one of a preset traveling distance and a preset time and number of times. 2. The method according to claim 1, wherein
A fuel remaining amount detecting device for a vehicle according to claim 1. 5. An apparatus according to claim 5, further comprising a replenishment determining means for determining refueling, wherein said output means determines an actual remaining fuel in the fuel tank until refueling is performed when the continuity determining means determines that the fuel is replenished. 5. The apparatus according to claim 1, further comprising a step of outputting that the amount falls below the reference value.