JP2001116607A - Residual fuel warning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a residual fuel warning device capable of being easily fitted to an existing fuel meter for vehicles and arbitrarily changing a residual fuel warning value. SOLUTION: A signal line 1e is connected to a signal line (residual fuel detection line) 10 electrically connecting a fuel meter 8 and a fuel sensor 9 preinstalled in a vehicle. A reference voltage generation means 2 is connected to a power line for the vehicle to generate a reference voltage. An input voltage from the signal line 1e is compared with the reference voltage by a comparing part (comparing means) 3. An indicating part (warning means) 6 indicates a predetermined fuel residue on the basis of the determined result by the comparing part 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a remaining fuel warning device which issues a warning when the fuel in a fuel tank mounted on a vehicle becomes lower than a predetermined value.

[0002]

2. Description of the Related Art A residual fuel warning device for a vehicle (for example, an automobile) is provided with a thermistor in a fuel tank of the vehicle. The thermistor is immersed in fuel (there is fuel) and is not immersed. It is common to turn on a display unit such as an LED or a lamp according to a change in the resistance value of the thermistor between a state (a state without fuel) and notify the driver that the fuel is below a predetermined value. .

[0003] In such a residual fuel warning device, a residual fuel warning value of fuel in the fuel tank is determined according to an arrangement position of the thermistor in the fuel tank. The fuel warning value is set to 10 liters, and the arrangement position of the thermistor is determined so that a warning is displayed on the display unit when the fuel in the fuel tank becomes 10 liters or less.

[0004]

In the residual fuel warning device having such a configuration, the position of the thermistor is fixed, so that the warning display on the display cannot be changed. In recent years, there has been a tendency for the fuel consumption rate to increase, and there is a demand for a residual fuel warning device that allows the user to freely set the residual fuel warning value. .

[0005] In recent years, the cost of vehicle meters has been reduced, and the number of vehicle meters without a remaining fuel warning function has been increasing. There is a need for a remaining fuel warning device that can be easily attached to a fuel meter provided in a combination meter.

Accordingly, the present invention provides a remaining fuel warning device which can be easily attached to a fuel meter which is an existing vehicle meter, and which can also arbitrarily change a remaining fuel warning value.

[0007]

According to the present invention, there is provided a remaining fuel warning device which issues an alarm when the fuel in a fuel tank mounted on a vehicle falls below a predetermined value. A signal line connected to a fuel detection line that electrically connects a fuel gauge and a fuel sensor mounted in advance on the vehicle, and an input value input from the signal line and an arbitrarily set reference value. And a notifying means for notifying a predetermined remaining amount of fuel based on the determination result by the comparing means.

[0008] Further, there is provided a setting means for enabling the reference value to be changed.

Also, there is provided a remaining fuel warning device for issuing an alarm when the fuel in a fuel tank mounted on a vehicle becomes equal to or less than a predetermined value, wherein a warning is provided between a fuel gauge and a fuel sensor previously mounted on the vehicle. A signal line connected to a fuel detection line electrically connecting the vehicle, a reference voltage generating means connected to a power supply line of the vehicle to generate a reference voltage value, an input voltage value from the signal line and the reference voltage value Means for comparing
Notification means for notifying a predetermined remaining amount of fuel based on the determination result by the comparison means.

Further, the reference voltage generating means includes a variable resistor capable of changing the reference voltage value.

In addition, an input voltage stabilizing circuit for suppressing a change in an input voltage value is provided between the signal line and the comparing means.

[0012]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

1 and 2, a vehicle residual fuel warning device A includes a distribution cable 1, a reference voltage generator (reference voltage generator) 2, a comparator (comparator) 3, and a delay circuit (input circuit). It comprises a voltage stabilizing circuit 4, a driving circuit 5, and a display unit (notifying means) 6.

The wiring cable 1 includes a battery power supply Vcc mounted on the vehicle and an ignition switch (IG) of the vehicle.
Power supply line (power supply line) 1 connected via N switch 7
a, a ground (GND) line 1b, and a signal line 1c connected to a signal line (fuel detection line) 10 that connects a fuel gauge 8 and a fuel sensor 9 mounted on the vehicle in advance. Note that the power supply (battery power supply Vcc) supplied via the IGN switch 7 is called an IGN power supply.

In the fuel sensor 9, a slider operating in conjunction with a float floating in the fuel tank slides on a resistor formed by printing or winding, and the remaining fuel in the fuel tank is removed. Is a general fuel detecting means for detecting a change in resistance value.

The reference voltage generator 2 includes first and second resistors 2a and 2b for dividing the power supply voltage of the battery power supply Vcc.
And between the first resistor 2a and the second resistor 2b to generate a reference voltage value in the comparison unit 3,
And a variable resistor 2c capable of adjusting the reference voltage value.

The comparing section 3 is composed of a comparator, and compares a reference voltage value from the reference voltage generating section 2 with an input voltage value from the signal line 1c in the wiring cable 1,
It operates when the input voltage value becomes equal to or higher than the reference voltage.

The delay circuit 4 is an input voltage stabilizing circuit that suppresses a voltage change in accordance with a change in the resistance value of the fuel sensor 9 transmitted to the signal line 1c and prevents a malfunction of the comparison unit 3. It is constituted by a differentiating circuit including the capacitor 4b.

The drive circuit 5 operates the display section 6 in accordance with the operation of the comparison section 3, and includes a PNP transistor 5a, a base resistor 5b for determining a base current of the transistor 5a, and a transistor 5a. A noise absorption circuit (base-
A resistor and a capacitor 5c provided in parallel between the emitters. When the IGN power supply is connected to the emitter of the transistor 5a via the protection circuit 11 and the base of the transistor 5a becomes L level in accordance with the operation of the comparison unit 3, the drive circuit 5
Operates. The protection circuit 11
Is an overcurrent protection circuit composed of a resistor 11a, a Zener diode 11b, and an electrolytic capacitor 11c and for the drive circuit 5.

The display section 6 is a notifying means for giving a warning display to the driver when the fuel in the fuel tank becomes equal to or less than a predetermined value, and operates by turning on / off the transistor 5a in the drive circuit 5. . The display unit 6 includes an LED 6a and a current limiting resistor 6b.

The above components constitute a residual fuel warning device A. The remaining fuel warning device A having such a configuration sets a reference voltage value using a variable resistor 2c provided in the reference voltage generation unit 2, and responds to the reference voltage value and a fluctuation in the liquid level in the fuel tank. When the input voltage value is equal to or higher than the reference voltage value, the driving circuit 5 is operated and the L of the display unit 6 is changed.
By turning on the ED 6a, it is possible to inform the driver of the remaining amount of fuel in the fuel tank, and it is easily used as a remaining fuel warning device in a vehicle meter (fuel gauge) having no remaining fuel warning. Function can be added.

Further, the signal line 10 for electrically detecting the fluctuation of the fuel sensor 9 is inserted into the signal line 10 for electrically connecting the fuel sensor 9 and the fuel gauge 8 mounted on the vehicle. Therefore, an inexpensive remaining fuel warning device can be obtained.

The remaining fuel warning device A includes a variable resistor 2
By selecting c, the remaining fuel warning value of the fuel in the fuel tank can be set, for example, within a range of １ ／ (half) or less of the capacity of the fuel tank. The degree can be improved.

Further, since the remaining fuel warning device A includes the delay circuit 4 serving as an input voltage stabilizing circuit, it is possible to prevent a false report on the display unit 6 due to a change in the fuel level when the vehicle is running. Does not give a sense of discomfort to the person.

In the embodiment of the present invention, the display section 6 is constituted by LEDs, but in the present invention,
Notification means including a lamp and a buzzer may be used.

Further, in the embodiment of the present invention, a comparator is used as the comparing means, and the reference voltage value from the reference voltage generating section is compared with the input voltage value from the signal line 1e. A microcomputer (hereinafter, referred to as a microcomputer) is used as comparison means, and a reference value is set in the microcomputer using a setting switch (setting means) such as a digital switch or a rotary switch, and the reference value and an input value from the signal line 1e are set. The remaining fuel may be warned by performing a comparison process of

[0027]

The present invention relates to a remaining fuel warning device which issues an alarm when the fuel in a fuel tank mounted on a vehicle becomes lower than a predetermined value, and arbitrarily sets the remaining fuel warning value of the fuel in the fuel tank. Since it can be changed, the degree of freedom of the method of using the remaining fuel warning device can be improved.

Also, the fuel warning device has a simple structure in which a signal line for detecting a fluctuation of the fuel sensor is inserted into a fuel detection line electrically connecting the fuel sensor and the fuel gauge mounted on the vehicle. It is possible to easily add a function as a remaining fuel warning device to a vehicle (instrument) not provided with Also, because of the simple configuration,
An inexpensive remaining fuel warning device can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a remaining fuel warning device according to an embodiment of the present invention.

FIG. 2 is a circuit diagram of the remaining fuel warning device of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wiring code 1a Power supply line (power supply line) 1e Signal line 2 Reference voltage generation part (reference voltage generation means) 2c Variable resistor 3 Comparison part (comparison means) 4 Delay circuit (input voltage stabilization circuit) 6 Display part (notification means) 8) Fuel gauge 9 Fuel sensor 10 Signal line (remaining fuel detection line)

Claims (5)

[Claims] 1. A remaining fuel warning device for issuing a warning when the fuel in a fuel tank mounted on a vehicle becomes equal to or lower than a predetermined value, wherein a warning is provided between a fuel gauge and a fuel sensor previously mounted on the vehicle. A signal line connected to a fuel detection line electrically connecting the fuel cell, comparison means for comparing an input value input from the signal line with an arbitrarily set reference value, and a fuel based on a determination result by the comparison means. And a notifying means for notifying a predetermined remaining amount of the remaining fuel. 2. The remaining fuel warning device according to claim 1, further comprising a setting unit configured to change the reference value. 3. A remaining fuel warning device for issuing an alarm when the fuel in a fuel tank mounted on a vehicle becomes equal to or lower than a predetermined value, wherein a warning is provided between a fuel gauge and a fuel sensor previously mounted on the vehicle. A signal line connected to a fuel detection line electrically connecting the vehicle, a reference voltage generating means connected to a power supply line of the vehicle to generate a reference voltage value, an input voltage value from the signal line and the reference voltage value And a notifying unit for notifying a predetermined remaining amount of fuel based on a result of the determination by the comparing unit. 4. The remaining fuel warning device according to claim 3, wherein the reference voltage generation means includes a variable resistor capable of changing the reference voltage value. 5. The remaining fuel warning according to claim 3, further comprising an input voltage stabilizing circuit for suppressing a change in an input voltage value between the signal line and the comparing means. apparatus.