JP3805891B2 - Vehicle fuel level detection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fuel remaining amount detection device for a vehicle that notifies a driver by turning on a warning lamp when the remaining fuel amount is low.
[0002]
[Prior art]
Conventionally, in a vehicle such as an automobile, when the remaining amount of fuel is low, a fuel remaining amount warning lamp provided on a combination meter or the like of an instrument panel is turned on to notify the driver.
[0003]
As a measuring means for measuring the remaining amount of fuel in the fuel tank, for example, a float is provided in a variable resistor in the fuel tank so that the remaining amount of fuel is obtained from the liquid level in the fuel tank. A fuel sender is used.
[0004]
However, since the liquid level in the fuel tank fluctuates greatly due to the influence of the vibration, posture, etc. of the vehicle, there is a possibility that there are many errors due to these factors in the remaining amount of fuel measured instantaneously. For this reason, the average value of the instantaneous fuel remaining amount for a predetermined time is generally used as the fuel remaining amount.
[0005]
Further, in order to accurately measure the remaining fuel amount, for example, in Japanese Examined Patent Publication No. 63-44176, when the fuel tank is fully filled, the operation value is pushed to set the fuel value to the maximum. The fuel used by the engine ejection amount signal of the vehicle is subtracted from the fuel, and the fuel remaining value obtained as a result of the subtraction is compared 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 amount is measured.
[0006]
[Problems to be solved by the invention]
However, it is difficult for the measuring means such as the fuel sender to accurately measure up to about 0 liters in the fuel tank, so that the remaining amount of fuel in the fuel tank is still at a level where it is not necessary to warn the driver. Regardless, the remaining fuel level may be measured and the remaining fuel level warning lamp may be turned on.
[0007]
In particular, in the fuel tank in which the central part of the fuel tank is formed of a main tank and a sub tank due to the escape of the propeller shaft or the like, a so-called saddle type fuel tank, It is common to measure the remaining amount of fuel using two measuring means for the main tank and sub tank, respectively, and the total value is used as the fuel amount. If the measuring means cannot sense up to 0 liter, the vehicle will turn When the fuel is returned from the main tank side to the sub tank side, which was almost 0 liters, the decrease in the remaining fuel level on the main tank side can be measured, but the increase in the remaining fuel level on the sub tank side is measured. Since this is not possible, there is a possibility that the remaining fuel amount warning light is turned on by measuring the remaining amount of fuel as if it was significantly reduced.
[0008]
In order to improve this, it is conceivable to devise the shape of the fuel tank, the number of measuring means and the mounting position, and to use a measuring means applying a thermistor or the like that can measure relatively accurately up to around 0 liters. However, it becomes very complicated and expensive.
[0009]
The present invention has been made in view of the above circumstances. Even if it is a saddle type fuel tank, it is possible to easily and inexpensively detect the remaining amount of fuel in a vehicle using conventional measuring means. An object is to provide a quantity detection device.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, a fuel remaining amount detection device for a vehicle according to the present invention as set forth in claim 1 comprises a fuel remaining amount measuring means for measuring a remaining amount of fuel in a fuel tank, and a reference value set in advance for the remaining amount of fuel. a lower judgment means for judging whether below, during the travel distance set in advance, the remaining fuel amount is determined and continuously determining means for determining that it is to continue communicating below the reference value, and continues in the continuity judgment section Output means for outputting that the actual amount of remaining fuel in the fuel tank is below the reference value.
[0011]
In the vehicle fuel remaining amount detecting apparatus according to claim 1, the fuel remaining amount measuring means measures the fuel remaining amount in the fuel tank, and the lower limit determining means determines whether the fuel remaining amount is below a preset reference value. determines a continuous determination means, during the travel distance set in advance, the remaining amount of fuel that is to continue communicating below the reference value. Then, the output means outputs that the actual fuel remaining amount in the fuel tank is lower than the reference value when it is determined by the continuity determining means that the continuity is determined. For this reason, even if it is for a short time, it travels at high speed and consumes fuel, and when the remaining amount of fuel falls below the reference value, it is reliably output from the output means.
[0012]
According to a second aspect of the present invention, there is provided a fuel remaining amount detecting device for a vehicle according to the present invention, wherein fuel remaining amount measuring means for measuring a fuel remaining amount in a fuel tank and whether the fuel remaining amount falls below a preset reference value. A lower limit determination means; a continuous determination means for determining that the remaining amount of fuel continuously falls below the reference value for at least one of a preset travel distance and a preset time and number of times; Output means for outputting that the actual fuel remaining amount in the fuel tank falls below the reference value when the continuous determination means determines that the fuel is continuous.
[0013]
In the vehicle fuel remaining amount detecting apparatus according to the second aspect, the fuel remaining amount measuring means measures the fuel remaining amount in the fuel tank, and the lower limit determining means determines whether the fuel remaining amount is below a preset reference value. The continuous determination means determines that the remaining fuel level continuously falls below the reference value for at least one of a preset travel distance and a preset time and number of times. Then, the output means outputs that the actual fuel remaining amount in the fuel tank is lower than the reference value when it is determined by the continuity determining means that the continuity is determined. For this reason, even if it is a short time, it travels at high speed and consumes fuel, and the remaining amount of fuel falls below the above reference value, or even if the travel distance is short, idling, climbing, and congestion When the vehicle travels and consumes fuel, and the remaining amount of fuel falls below the reference value, it is reliably output from the output means.
[0015]
Further, the fuel remaining amount detecting apparatus for a vehicle according to the present invention according to claim 3, the fuel level detecting device for a vehicle according to claim 1 or claim 2 wherein has a supply determining means for determining the refueling, The output means outputs the fact that the actual fuel remaining amount in the fuel tank is below the reference value until the fuel is replenished when it is determined that the continuous determination means determines that it is continuous. This changes the fuel level in the fuel tank and prevents the output from the output means from being unstable.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 3 show an embodiment of the present invention, FIG. 1 is an explanatory diagram of the overall outline of a remaining fuel amount detection device, FIG. 2 is a flowchart of a remaining fuel amount detection program executed immediately after the ignition is turned on, and FIG. Is a flowchart of a normal fuel remaining amount detection program.
[0017]
In FIG. 1, reference numeral 1 denotes a fuel tank of a four-wheel drive vehicle. The fuel tank 1 is disposed and fixed below a rear seat (not shown), for example. 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 portion at the bottom formed into a concave shape, and a main tank (right tank in the figure) 1a and a sub tank This is a so-called saddle type fuel tank divided into two tanks 1b (left tank in the figure).
[0018]
The main tank 1a of the fuel tank 1 is provided with a fuel pump 2 that supplies and circulates fuel to the engine side, and a jet pump 3 that transfers fuel from the sub tank 1b to the main tank 1a side.
[0019]
For this reason, when the liquid level of the fuel descends and the main tank 1a and the sub tank 1b are separated by the convex portion at the substantially central portion of the bottom of the fuel tank 1, the fuel in the sub tank 1b is jetted by the jet pump 3. Since it is transferred to the main tank 1a through the filter 4 and the transfer line 5, it first descends from the fuel level in the sub tank 1b.
[0020]
Further, the fuel sucked in the main tank 1a through the fuel pump filter 6 by the fuel pump 2 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 pressure regulator 11 Is returned to the fuel tank 1 through the return line 12.
[0021]
Further, reference numeral 13 in the figure denotes a canister constituting a fuel evaporative emission prevention system. When evaporative gas generated in the fuel tank 1 reaches a set pressure via the fuel separator 14, the 2-way valve 15 is pushed open. It flows into the canister 13 and is stored. When the throttle valve 16 is opened during engine operation, the check valve 18 of the purge line 17 is opened due to the negative throttle pressure, and the gas stored in the canister 13 is sucked into the injection body together with the outside air sucked from the lower part of the canister 13. Burned. This suppresses the release of HC into the atmosphere. When the negative pressure in the fuel tank 1 exceeds the set pressure, the air entering from the lower portion of the canister 13 is guided to the fuel tank 1 by the action of the 2-way valve 15 so that the tank internal pressure is always kept within a predetermined range. The deformation of the tank 1 is prevented.
[0022]
The main tank 1a and the sub tank 1b have floats 22a and 22b attached to the variable resistors 21a and 21b so that the variable resistors 21a and 21b have resistance values according to the liquid level in the main tank 1a and the sub tank 1b. Fuel senders 20a and 20b configured as shown are provided, and the fuel senders 20a and 20b are electrically connected in series, and a combined resistance value of the resistance value of the fuel sender 20a and the resistance value of the fuel sender 20b. However, the measurement can be performed by the control device 23 composed of a microcomputer or the like in which the CPU, ROM, RAM, input port, and output port are connected to each other via a bus line.
[0023]
In order to display this combined resistance value as the remaining amount of fuel in the fuel tank 1, a fuel remaining amount indicator 24 is connected in parallel between the battery 25 to the control device 23 and the connecting line of the combined resistance value. The fuel remaining amount indicator 24 is connected to the control device 23.
[0024]
Further, the control device 23 is adapted to electrically convert or input the mileage signal displayed by the odometer disposed in the speedometer portion (not shown) of the combination meter.
[0025]
Further, the control device 23 is connected to a fuel remaining amount warning light 26 which is disposed in the speedometer portion of the combination meter and warns the driver that the remaining amount of fuel is low.
[0026]
Next, a fuel remaining amount detection program executed by the control device 23 will be described with reference to the flowcharts of FIGS. In the fuel remaining amount detection program of the present invention, 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 every predetermined time.
[0027]
First, immediately after the ignition is turned on (FIG. 2), in step (hereinafter abbreviated as “S”) 101, necessary RAM initialization is performed, and the process proceeds to S102, where the average value of the remaining amount of fuel for one second immediately after the ignition is turned on. Fa1 is read.
[0028]
That is, instead of using the instantaneous combined resistance value that can be read from the fuel senders 20a and 20b as a value indicating the remaining amount of fuel, the average value Fa1 of the combined resistance value for a predetermined short time (for example, 1 second as described above) is used. By setting the value to indicate the remaining amount of fuel, a remaining fuel value with as little error as possible is obtained. Note that the term “short time” is used because this processing is processing immediately after the ignition is turned on, so that the meaning is lost for a long time.
[0029]
Next, the process proceeds to S103, and it is determined whether or not there is an output that is lit on the remaining fuel amount warning lamp 26 before the ignition is turned off. If there is an output that is lit to the remaining fuel level warning lamp 26, the process proceeds to S104, where the fuel level average value Fa1 for one second is set in advance, and the fuel level drops. When the fuel is separated into the main tank 1a and the sub tank 1b, the sum of the maximum remaining fuel amount stored in the main tank 1a and the minimum remaining amount detected by the fuel sender 20b of the sub tank 1b, for example, 12 liters or more. Judge whether or not. For example, it is assumed that the remaining fuel level warning lamp 26 is turned on when it is 10 liters or less, and further, the maximum remaining fuel amount of the main tank 1a when separated is 10 liters, and the minimum detection of the fuel sender 20b of the sub tank 1b. If the remaining amount is 2 liters, the fuel remaining amount warning lamp 26 is turned on before the ignition is turned off, and even if the error that the minimum detected remaining amount of the fuel sender 20b of the sub tank 1b is 2 liters is considered. This is a process for determining whether what is determined to be less than liters is 12 liters or more and increasing, or whether it is still less than 12 liters.
[0030]
As a result of S104, when it is determined that the fuel remaining average value Fa1 for one second is 12 liters or more, the fuel has increased and the fuel has been replenished (when Fa1 ≧ 12L (liter)), the process proceeds to S105. The process proceeds to clear a counter 10L, which will be described later, (C10 = 0), clear a travel distance counter L, which will be described later (L = 0), turn off the fuel remaining amount warning lamp 26, and perform processing immediately after turning on the ignition. Exit.
[0031]
If the average remaining fuel value Fa1 for one second remains less than 12 liters as a result of S104 (in the case of Fa1 <12L), the fuel remaining amount warning lamp 26 remains on as it is and the processing immediately after the ignition is turned on. Exit.
[0032]
On the other hand, if it is determined in S103 that there is no output to the fuel remaining amount warning lamp 26 before the ignition is turned off and the light is extinguished, the routine proceeds to S106, where the average value Fa1 of the remaining amount of fuel for one second is set in advance. It is determined whether it is a low value, for example, 4 liters or less, and it is determined whether the fuel has decreased after the vehicle is stopped.
[0033]
If it is determined in S106 that the fuel remaining average 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 is stopped, the process proceeds to S107, and the remaining fuel warning light 26 If the average value of remaining fuel Fa1 per second is more than 4 liters (Fa1> 4L) and it can be determined that there is not much fuel decrease after the vehicle is stopped, that is, the remaining fuel The warning lamp 26 remains off, and the processing immediately after the ignition is turned on ends.
[0034]
Next, a normal process executed every predetermined time after the above-described process immediately after the ignition is turned on will be described with reference to the flowchart of FIG.
[0035]
First, in S201, the travel distance δL since the previous reading is read, and in S202, the fuel remaining average value Fa60 for one minute is read. That is, in the normal process, for the sake of accuracy, the combined resistance value is longer than the average remaining fuel value Fa1 for one second used in the process immediately after the ignition is turned on and has a length that can sufficiently follow the control (for example, one minute). The average value Fa60 is a value indicating the remaining fuel amount.
[0036]
Next, the process proceeds to S203, where there is currently an output to be lit on the remaining fuel level warning lamp 26, it is determined whether or not the remaining fuel level warning lamp 26 is lit, and the remaining fuel level warning lamp 26 is lit. In this case, the process proceeds to S204, where it is determined whether the average remaining fuel value Fa60 for one minute is increased to 12 liters or more, or whether it is still less than 12 liters. This determination is the fuel supply determination process (S104 described above) described in the process immediately after the ignition is turned on.
[0037]
If it is determined in step S204 that the fuel remaining average value Fa60 for one minute is 12 liters or more and the fuel has increased and fuel has been replenished (when Fa60 ≧ 12L), the process proceeds to step S205. In addition, the counter C10 of 10 L or less is cleared (C10 = 0), the mileage counter L is cleared (L = 0), the remaining fuel level warning lamp 26 is turned off, and the normal processing is terminated (S105). Correspondence).
[0038]
If the average fuel remaining value Fa60 per minute remains less than 12 liters as a result of S204 (when Fa60 <12L), the fuel remaining amount warning lamp 26 remains on and normal processing is terminated. To do.
[0039]
Since S203 to S205 are provided in this way, when the remaining fuel amount warning lamp 26 is turned on, the remaining fuel amount warning lamp 26 remains turned on until fuel is supplied.
[0040]
On the other hand, if it is determined in S203 that the fuel remaining amount warning lamp 26 is currently turned off, the process proceeds to S206, where the fuel remaining average value Fa60 for one minute is a preset low value, For example, it is determined whether or not it is 4 liters or less, and it is determined whether or not the fuel has further decreased.
[0041]
If it is determined in S206 that the fuel remaining average value Fa60 for one minute is 4 liters or less (Fa60 ≦ 4L) and it can be determined that the fuel has further decreased, the process proceeds to S213, and the fuel remaining amount warning lamp 26 is turned on. When the normal process is finished, if the average remaining fuel value Fa60 for one minute is larger than 4 liters (Fa60> 4L) and it can be determined that there is not much fuel reduction, the process proceeds to S207.
[0042]
In this S207, it is determined whether or not the fuel remaining average value Fa60 for 1 minute is a preset warning target value, that is, 10 liters or less, and the fuel remaining average value Fa60 for 1 minute is less than 10 liters. If there are many (Fa60> 10L), the process proceeds to S208, the counter C10 is continuously cleared to 10L or less (C10 = 0), the travel distance counter L is cleared (L = 0), and the remaining fuel amount warning lamp 26 is turned off. The normal process is terminated.
[0043]
If it is determined in S207 that the average remaining fuel value Fa60 for one minute is 10 liters or less (Fa60 ≦ 10L) and the warning stage is in progress, the process proceeds to S209, and the counter C10 is continuously counted up (less than 10L). C10 = C10 + 1) and proceed to S210.
[0044]
In S210, it is determined whether the continuous 10L or less counter C10 has reached 10 times or more (a preset number of times). If the continuous 10L or less counter C10 has become 10 times or more, the process proceeds to S213, and the remaining fuel amount is determined. While the warning lamp 26 is turned on to end the normal processing, if the counter C10 of 10 L or less does not reach 10 times, the process proceeds to S211.
[0045]
In S211, the travel distance counter L is updated (L = L + δL), the process proceeds to S212, and it is determined whether or not the travel distance counter L has reached 10 km (a preset distance).
[0046]
If the travel distance counter L reaches 10 km as a result of the determination in S212, the process proceeds to S213, the remaining fuel level warning lamp 26 is turned on and the normal processing is terminated, while the travel distance counter L reaches 10 km. If not, the fuel remaining amount warning lamp 26 remains off and normal processing ends.
[0047]
That is, the continuous 10L or less counter C10 counts how many times the one minute fuel remaining average value Fa60 is 10 liters or less, and the mileage counter L is one minute fuel remaining. When the average value Fa60 is 10 liters or less, it counts how many km it continues. As described above, when it continues 10 times or 10 km continuously, the remaining fuel level warning lamp 26 is turned on and even once in the middle. If a result of more than 10 liters is obtained, the continuous 10L or less counter C10 and the travel distance counter L are reset.
[0048]
As a result, in the case of traveling that consumes a large amount of fuel for a short time at high speed traveling, it is determined by the traveling distance counter L. On the other hand, the traveling distance is small but large due to traffic jams, climbing, or long-term idling, etc. When the fuel is consumed, it is determined by the counter C10 that the continuous 10L or less is continued, and the remaining fuel amount warning lamp 26 is surely turned on.
[0049]
【The invention's effect】
As described above, according to the present invention, the fuel remaining amount measuring means for measuring the fuel remaining amount in the fuel tank, the lower limit determining means for determining whether the fuel remaining amount is lower than a preset reference value, and the fuel A continuous determination means for determining that the remaining amount is below the reference value is continued under preset conditions, and an actual fuel remaining amount in the fuel tank when the continuous determination means determines that the remaining amount is continuous. Output means for outputting that the value is below the value, so even with a saddle type fuel tank, the remaining amount of fuel can be accurately detected simply and inexpensively using conventional measuring means. It becomes possible.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of the overall outline of a fuel remaining amount detecting device. FIG. 2 is a flowchart of a fuel remaining amount detecting program executed immediately after the ignition is turned on. FIG. 3 is a flowchart of a normal fuel remaining amount detecting program. ]
DESCRIPTION OF SYMBOLS 1 Fuel tank 1a Main tank 1b Sub tank 2 Fuel pump 3 Jet pump 20a, 20b Fuel sender 23 Control apparatus 26 Fuel remaining amount warning light

Claims (3)

The fuel remaining amount measuring means for measuring the fuel remaining amount in the fuel tank, the lower limit determining means for determining whether the fuel remaining amount is below a preset reference value, and the fuel remaining amount between the preset traveling distance a continuous determination means for determining that it falls below the reference value is continued communication, outputs the actual fuel quantity of the fuel tank when it is determined that continuous the continuous determination means outputs the below the reference value And a fuel remaining amount detecting device for a vehicle. Fuel remaining amount measuring means for measuring the fuel remaining amount in the fuel tank, lower limit determining means for determining whether the fuel remaining amount is lower than a preset reference value, a preset travel distance, a preset time and number of times A continuous determination means for determining that the remaining amount of fuel is below the reference value for at least one of the continuous values; and the actual fuel in the fuel tank when determined by the continuous determination means to be continuous A fuel remaining amount detection device for a vehicle, comprising: output means for outputting that the remaining amount is below the reference value . Replenishment determining means for determining replenishment of fuel, and the output means determines that the actual fuel remaining amount in the fuel tank is the reference value until fuel replenishment is performed when it is determined that the continuous determining means determines that the fuel supply is continued. The fuel remaining amount detection device for a vehicle according to claim 1 or 2, wherein a value of less than is output .

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