JP2510368Y2 - Fuel gauge with remaining amount warning device - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial field of application) The present invention indicates the remaining amount of fuel, and also issues a warning when the remaining amount of fuel falls below a predetermined amount. The present invention relates to a fuel gauge with a warning device.

(Prior Art) As a fuel gauge with a remaining amount warning device, which is equipped with a warning lamp that indicates the remaining fuel amount and is turned on when the remaining fuel amount falls below a predetermined amount, for example, one shown in FIG. 7 is known. ing. The fuel gauge has a scale 110 for displaying the remaining fuel amount on the dial 100, a pointer 120 for moving on the scale 110, and a warning lamp 13 which is turned on when the remaining fuel amount falls below a predetermined amount.
It is equipped with 0 and. In addition, 160 is a switch and 170 is a power supply.

Here, the drive circuit of the pointer 120 and the warning lamp 130 are
It is connected to a sender 150 mounted on the fuel tank 140.
The sender 150 is provided with, for example, a fixed stay 153 extending toward the bottom of the fuel tank 140, and a float arm 156 rotatable about the sender 150. The float 1 is attached to the tip of the float arm 156.
55 is provided, and the float 155 moves in accordance with the vertical movement of the liquid surface of the fuel to rotate the float arm 156, and the rotation changes the resistance value of the variable resistor in the sender 150. The pointer 120 is changed according to the increase or decrease of the fuel. Further, a thermistor 154 for detecting the remaining amount of fuel is provided at the tip of the stay 153, and the warning lamp 130 is turned on when the fuel is low and the thermistor 154 is exposed from the fuel.

FIG. 8 is a drive circuit for the pointer 120 and the warning lamp 130, and FIG. 9 is an external view of a sender 150 including a stay 153 to which a thermistor 154 is attached and a float arm 156 to which a float 155 is attached. In both figures, 151 is a disc-shaped mounting board fixed to the fuel tank 140, and 152 is a mounting board.
A frame of 151, a slider 158, a resistance plate 159, a resistor 159b, a conductive contact 159c, a resistor R, L _{1 to} L ₃ are pointers 12
Shows a coil moving 0.

Note that FIG. 10 shows the appearance of the resistance plate 159.On the substrate 159a made of ceramic or the like, a plurality of resistors 159b formed by printing are printed, and the same is formed by printing, and one end is connected to the resistor 159b. At the other end, there is a plurality of conductive contact bodies 159 with which a slider 158 slides. The F side indicates the side where the fuel is full, and the E side indicates the side where the residual fuel is small.

In this fuel gauge with a remaining amount warning device, reduction of the remaining fuel amount → descending float 155 → sliding float arm 156 → resistor 159b
Of the resistance value of →, the current flowing through the coils L _{1 to} L ₃ changes, and the combined magnetic field changes, and the pointer 120 moves on the scale 110 to indicate the remaining fuel amount. Then, when the fuel remaining amount becomes scarce and the thermistor 154 is exposed from the fuel to the air, the resistance value of the thermistor 154 is changed and the warning lamp 130 is turned on.

However, the fuel gauge with the remaining amount warning device is the thermistor 15
Since the current flowing through the warning lamp 130 is controlled by using the resistance change of 4, there is a problem that the operating range of voltage and temperature is narrow, and the influence of the load characteristics is very large. There was a problem that was limited. Also, because the remaining fuel amount indication and remaining fuel amount warning are completely different configurations,
There was a problem that the remaining amount instruction and the remaining amount warning did not work well.

Therefore, in order to solve these problems, the applicant has
We proposed a fuel gauge with a remaining amount warning device that can perform a remaining amount instruction and a remaining amount warning in one circuit. That is, the applicant has proposed a fuel gauge with a remaining amount warning device as shown in the circuit diagrams of FIGS. 11 to 13. Among them, in the proposed circuit of FIG. 13, a delay circuit 60 is added to the warning lamp drive circuit in order to prevent flickering of the warning lamp.
For example, the circuit of FIG. 14 is used.

In this proposed fuel gauge with remaining amount warning device, the resistance value changes due to the movement of the slider due to the displacement of the fuel level, the current changes, the combined magnetic field of the coil changes, and the pointer indicates the remaining fuel amount. To do. When the amount of remaining fuel decreases and the slider reaches the remaining amount warning point on the resistor, current flows through the warning lamp by the circuit and the lamp lights. Further, in the fuel meter with the remaining amount warning device provided with the delay circuit 60, even if the slider moves to the remaining amount warning position, the warning means does not operate immediately and operates with a certain time delay. There is no flicker.

(Problems to be solved by the invention) However, in the fuel gauge with the fuel level warning device proposed by the present applicant, for example, in the configuration shown in FIG.
There is a problem in that the fuel gauge is affected by the electric current to the light bulb 20 as the slider 11 becomes closer to the E side. Further, in the configuration using the delay circuit 60 as shown in FIG. 14, when the slider 11 is on the E side, the voltage between the warning point 13 and the ground rises due to the current of the fuel gauge, and the comparator IC70
It is necessary to set a high comparison voltage. Therefore, the slider
If 11 is on the F side of the warning point 13, there is a problem in that the cathode side of the diode serves as a positive electrode and the anode side serves as a negative electrode, and the resistance plate of the sender 150 is immersed in alcohol fuel or the like to undergo electrolytic corrosion. This electrolytic corrosion is comparator IC70
The higher the comparison voltage of, the more likely it is to occur.

The present invention solves the above-mentioned problems of the prior art, and its purpose is to eliminate the mutual interference between the current of the fuel gauge and the current of the light bulb or the delay circuit, and to use the remaining amount warning device using a comparator in the delay circuit. (EN) A fuel gauge with a remaining amount warning device that can set a low comparison voltage of a comparator and prevent electrolytic corrosion when a resistance plate is immersed in alcohol fuel. That is.

[Constitution of device]

(Means for Solving the Problems) A fuel gauge with a remaining amount warning device of the present invention that achieves the above-mentioned object is a slider that changes a position on a resistor according to a liquid level displacement in a fuel tank, and a slider. A fuel gauge with a remaining amount warning device, which comprises a remaining amount indicator for indicating the remaining amount of fuel by a change in resistance of the resistor, and a warning means for issuing a warning when the remaining amount of fuel decreases below a predetermined amount. In addition to providing a remaining amount warning point on the resistor of, the current backflow prevention means is provided between the remaining amount warning point and the resistor on the side where the slider is located when there is a lot of fuel, and the resistor and the warning means are connected. The connecting point on the resistor side of the connecting circuit to be connected is the end on the opposite side to the side where the resistor is connected to the remaining amount indicator, and when the slider reaches the remaining amount warning point of the resistor, warning means It is characterized in that it is configured to operate. Another aspect of the present invention is characterized in that the communication circuit is provided with a delay circuit.

(Operation) According to the fuel gauge with the remaining amount warning device of the present invention, when the slider slides to the remaining amount warning point, a current flows through the warning means by the communication circuit to operate the warning means. At this time, since the current flowing through the warning means flows from the end of the resistor opposite to the side connected to the remaining amount indicator, the fuel does not affect the remaining amount indicator side. Further, in the fuel gauge with the remaining amount warning device in the form of providing the delay circuit, the warning means does not operate immediately even when the slider moves to the remaining amount warning position, and the delay circuit operates with a certain time delay. , The voltage of the comparator IC can be set low because the voltage does not rise due to the current to the fuel level indicator.

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

FIG. 1 is an electric circuit diagram of a fuel gauge with a remaining amount warning device according to the present invention. The overall structure of the fuel gauge with the remaining amount warning device is
This is the same as the conventional configuration shown in the figure. In the figure, 10 is a resistor equipped in the sender 150 shown in FIG. 12, L _{1 to} L ₃ are coils for driving the pointer 120 also shown in FIG. 12, and 20 is a 12th line.
A warning lamp corresponding to 130 in the figure, 30 is a switch, and 40 is a power supply.

The resistor 10 includes the slider 11 fixed to the base end side of the float arm 156 of the sender 150 shown in FIG.
The resistance plate 12 is fixed to the frame of the mounting board of the slide plate 11, and the slider 11 slides on the resistance body 12b (conductive contact body 12c) of the resistance plate 12 as the float arm 156 slides. , The resistance is changed.

Here, as shown in FIG. 2A, the resistance plate 12 has a plurality of resistors 12b, one end of which is connected to the resistor 12b and the other end of which is a slider 11 on a substrate 12a made of ceramic or the like. It is formed by printing and forming a plurality of conductive contact bodies 12c which slide.
One end (A end shown in FIG. 1) of the resistor 12b is connected between the coil L ₁ and L _2, also the slider 11 and the other end portion of the resistor 12b which slides conductive contact It is connected to the ground G via the body 12c and the slider 11.

When the fuel tank 140 shown in FIG. 7 is filled with fuel, the slider 11 is located on the F side in FIG. 1 and slides to the E side in FIG. 1 as the fuel decreases. With the sliding of the slider 11 from the F side to the E side, the resistance value of the resistor 12b changes.

Figure 3 shows the displacement of the fuel level (change in the remaining amount) and the resistance plate 12.
In the graph showing the relationship between the voltage between A and B of the (resistor 12b), as is clear from the graph, the voltage is low when the liquid level is high (when the slider 11 is located on the F side). As the liquid level descends from this state, the slider 11 slides to the E side, and the voltage rises.

In this way, the slider 11 slides from the F side to the E side of the resistor 12b due to the displacement of the fuel level, and the resistance value of the resistor 12b changes (the voltage between A and B changes). ),
Magnetic field changes that occur in the coil L ₁ ~L ₃ a current value flowing through the coil L ₁ ~L ₃ is changed, the pointer 120 by the change in the magnetic field
Moves on the scale 110 (Fig. 7) to indicate the remaining amount of fuel.

The present invention is characterized in that the above-mentioned part for indicating the remaining fuel amount is used to operate the means for warning that the remaining fuel amount is low. Not using a thermistor.

That is, the sliding position on the resistor 12b (conductive contact body 12c) of the slider 11 when indicating the fuel remaining amount reduced to the extent that refueling is required is the remaining amount warning point 13, and Communication circuit 50 connecting the quantity warning point 13 and the warning lamp 20 to each other
Is provided. The connection point of the connecting circuit 50 to the resistance plate 12 is the end portion of the resistor 12b on the E side. Also, the remaining amount warning point 1
A diode 14 is interposed between the resistor 3 and the resistor 12b on the F side, and the anode side of the diode 14 is placed at a point F more than the remaining amount warning point 13.
Side resistor 12b, the cathode side is connected to the remaining amount warning point 13, and when the slider 11 is located on the F side of the remaining amount warning point 13, the contact circuit 50 is used. The current is prevented from flowing through the warning lamp 20.

The diode 14 is, as shown in FIG.
It is mounted on the board 12a, but the circuit has a warning level 13
And the resistor 12b on the F side, the alarm lamp 20 may be provided. A buzzer or the like may be used instead of the warning lamp 20.

In this way, the warning lamp 20 can be turned on even when the thermistor is not used, when the remaining fuel amount has decreased to the point where refueling is necessary. That is, when the remaining fuel amount decreases and the slider 11 reaches the position of the conductive contact body 12c corresponding to the remaining amount warning point 13, the slider 11, the conductive contact body 12c,
Contact circuit 50, a current flows through the warning lamp 20 via the resistor R _6, the warning lamp 20 is turned on. Even if the amount of remaining fuel decreases and the slider 11 moves to the E side,
11, the conductive contact member 12c, the resistor 12b, since the current flows through the circuit 50, the resistor R _6, remains lit.

Even current flows through the coil L ₁ ~L ₃ while the slider 11 is moved from the low warning point 13 on the E side, performs the remaining amount indication.
In addition, in the fuel meter with the remaining amount warning device of this embodiment, the slider is
When 11 becomes below the remaining amount warning point 13, the current of the warning lamp 20 flows from the E side, so the current of the fuel gauge and the warning lamp 20
There is no mutual interference of the electric currents of and the influence on the fuel indicating side does not occur. Moreover, the remaining amount warning point 13 can be freely set anywhere.

FIG. 4 shows a modification of the above embodiment, in which the slider 11
Is connected to the + side of the power supply 40 via the switch 30, the anode side of the diode 14 is still connected to the remaining amount warning point 13, and
The cathode side is connected to the resistor 12b on the F side of the remaining amount warning point 13. That is, plus and minus are opposite to the circuit shown in FIG. The other points are the same as those of the circuit shown in FIG. In this case as well, similar to the circuit shown in FIG. 1, when the slider 11 reaches the remaining amount warning point 13,
A current flows through the warning lamp 20 and it lights up.

FIG. 5 shows a circuit configuration of another embodiment of the present invention. This circuit is an example in which a delay circuit 60 is interposed in the communication circuit 50 of the fuel gauge with the remaining amount warning device shown in FIG. Is. The reason for interposing the delay circuit 60 in the communication circuit 50 is that the warning lamp 20 is turned on in the circuit of the embodiment shown in FIGS. 1 and 4 described above, and the resistor R ₆ , the communication circuit 50, and the remaining amount warning point. 1
3, when the current value passing through the conductive contact body 12c and the slider 11 is large, it is to prevent the adverse effect on the remaining amount indication after the remaining amount warning point 13, and also to prevent the vibration of the fuel level in the fuel tank Float arm 156 (Fig. 7) due to displacement
When the slider 11 vibrates and temporarily moves to the F side of the remaining amount warning point 13, the warning lamp 20 is repeatedly turned on and off.

In this embodiment, the connection point of the input of the delay circuit 60 interposed in the communication circuit 50 to the resistance plate 12 is E of the resistor 12b.
Side end. The delay circuit 60 may be incorporated in the resistance plate 12 as shown in FIG.

FIG. 6 specifically shows the delay circuit 60 of FIG. In the figure, the control means 70 is composed of a comparator IC, and the midpoints of the resistors R ₂₁ and R _{22 and} the midpoints of the resistors R ₂₃ and R ₂₄ are inputs to the comparator IC, respectively. If the slider 11 is on the F side of the remaining amount warning point 13,
Since the direction of the midpoint of R _21, R ₂₂ potential is higher than the intermediate point of the resistor R _23, R ₂₄ comparator IC is turned ON, the capacitor C is not charged, the transistor Q _2, Q ₃ is OFF It is in a state. When the slider 11 reaches the remaining amount warning point 13, on the contrary, the potential at the intermediate point between the resistors R ₂₁ and R ₂₂ becomes lower, so the comparator IC turns off and the capacitor C is charged. After a delay of the time constant determined by the resistor R ₂₈ , the transistors Q ₂ and Q ₃ are turned on and the warning lamp 20 is turned on.

As in this embodiment, the resistance plate 12 of the input terminal of the delay circuit 60
Since the connection point to the end of the resistor 12b on the E side can be prevented from increasing the voltage due to the current of the fuel gauge,
The comparison voltage of the comparator IC70 can be set low, and electrolytic corrosion when the resistance plate is immersed in alcohol fuel can be prevented.

[Effect of device]

As described above, according to the fuel gauge with the fuel level warning device of the present invention, mutual interference between the current of the fuel gauge and the current of the light bulb or the delay circuit is eliminated, so that the fuel level detection point can be arbitrarily set. is there. Further, since the detection comparison voltage of the delay circuit can be set low, it is possible to prevent galvanic corrosion during the resistance plate and combustion immersion. In particular, in a fuel meter with a remaining amount warning device using a comparator, the comparison voltage of the comparator can be set low, and electrolytic corrosion can be prevented when the resistance plate is immersed in alcohol fuel.

[Brief description of drawings]

FIG. 1 is a circuit diagram of an embodiment of a fuel gauge with a remaining amount warning device of the present invention, FIG. 2 (a) is a perspective view showing a mounted state of the circuit of FIG. 1, and FIG. 5 is a perspective view showing the mounted state, FIG. 3 is a graph showing the relationship between the liquid level displacement of fuel (change in remaining amount) and the voltage between A and B of the resistance plate (resistor), and FIG. 4 is FIG. 5 is a circuit diagram of a modified embodiment of the circuit shown in FIG. 1, FIG. 5 is a circuit diagram showing the configuration of another embodiment of the fuel gauge with a fuel level warning device of the present invention, and FIG. 6 is a delay circuit of FIG. FIG. 7 is a schematic diagram showing the whole of a conventional fuel gauge with a remaining amount warning device, FIG. 8 is a circuit diagram of a conventional fuel gauge with a remaining amount warning device, and FIG. Fig. 10 is a perspective view showing the appearance of the sender, Fig. 10 is a perspective view showing the appearance of the resistance plate, and Figs. 11 to 14 are circuit configuration diagrams of a conventional fuel gauge with a remaining amount warning device proposed by the applicant. Is. C ... Capacitor, 10 ... Resistor, 11 ... Slider, 12 ...
... resistor plate, 12a ... substrate, 12b ... resistor, 12c ... conductive contact body, 13 ... remaining amount warning point, 14 ... diode, 20 ...
… Warning means (warning lamp), 50 …… contact circuit, 60 …… delay circuit, 70 …… control means, 150 …… sender.

Claims (2)

(57) [Scope of utility model registration request] 1. A slider for changing a position on a resistor according to a liquid level displacement in a fuel tank, a remaining amount indicator for indicating a remaining amount of fuel by a resistance change of the resistor, and a remaining fuel amount. In a fuel gauge with a remaining amount warning device, which comprises a warning means for issuing a warning when the amount decreases below a predetermined amount, a remaining amount warning point is provided on the resistor of the resistor, and the remaining amount warning point and fuel are When there is a large amount of current, current backflow prevention means is provided between the resistor and the resistor on the side where the slider is located, and the connection point on the resistor side of the communication circuit that connects the resistor and the warning means is the resistor. A remaining amount warning device having an end portion on the side opposite to the side connected to the remaining amount indicator, and configured to operate the warning means when the slider reaches the remaining amount warning point of the resistor. Fuel gauge with. 2. A fuel gauge with a remaining amount warning device according to claim 1, wherein said circuit is provided with a delay circuit.