JPS5824741Y2 - automotive fuel gauge - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an automobile fuel measuring device for measuring the amount of fuel consumed by an internal combustion engine in an automobile.

As a conventional device of this kind, there is a fuel measuring device disclosed in Japanese Patent Application Laid-Open No. 137020/1985, which is equipped with an upper limit level sensor and a lower limit level sensor in the float chamber of a carburetor, and when the fuel in the float chamber reaches the lower limit liquid level, An electric signal from the lower limit level sensor opens the solenoid valve to supply fuel into the float chamber, and when the fuel in the float chamber reaches the upper limit liquid level due to this fuel supply, the electric signal from the upper limit level sensor opens the solenoid valve. is closed to stop the supply of fuel into the float chamber, and the amount of fuel consumed is measured from the number of times the electromagnetic valve is opened.

That is, it is assumed that a fixed amount of fuel is supplied into the float chamber by one opening operation of the solenoid valve, and the amount of fuel consumed is measured by multiplying the fixed fuel amount by the number of valve openings.

In the above device, the amount of fuel supplied into the float chamber by one opening operation of the solenoid valve is 4.2 cc.
Since the amount is small, fluctuations in the fuel consumption of the engine during the fuel supply time into the float chamber, that is, the time during which the solenoid valve is opened once, are ignored.

However, when we conducted an actual vehicle test on the above device, we found that when driving in the city, the amount of fuel supplied by the solenoid valve at one time was 4.
．． It was found that there was no problem with the accuracy of fuel measurement with 2cc, but when driving under high load such as on expressways, fuel consumption becomes intense and the amount of fuel supplied by the solenoid valve at one time is 4.2cc.
It has been found that because the number of particles increases, a measurement error of the order of 10% occurs.

The present invention was developed in response to the above problem, and its purpose is to measure the fuel consumption of the engine from the opening time of the solenoid valve with high precision regardless of the driving state of the vehicle. It is an object of the present invention to provide a fuel measuring device for an automobile that can measure fuel.

An embodiment of the present invention shown in the drawings will be described below.

In FIG. 1, 1 is a fuel tank shown as a compressed tank, 2 is a fuel pipe, 3 is a fuel filter installed in the middle of the fuel pipe 2, and 4 is a fuel pump that pumps fuel from the fuel filter 3. , 5 is a return pipe that communicates the discharge side of the fuel pump 4 with the fuel tank 1 in order to prevent paper lock caused by a rise in fuel temperature.
is provided with an aperture 6.

The fuel pipe 2 on the discharge side of the fuel pump 4 opens into a float chamber 7 of the carburetor.

This float chamber 7 is shown enlarged.

8 is a cylindrical float guide fixed to the float chamber 7 to prevent fuel from entering; 9 is a float that is guided vertically in the figure by the float guide 8 and moves according to the height of the fuel liquid level; A permanent magnet 10 is integrally fixed.

Further, in the hollow part of the float guide 8, a normally open type reed switch (hereinafter referred to as the lower limit reed switch) 11 as a fuel liquid level lower limit level sensor and a normally closed type reed switch (hereinafter referred to as the upper limit reed switch) as a fuel liquid level upper limit level sensor 11 are provided. A reed switch (hereinafter referred to as a reed switch) 12 is fixed at a predetermined position, and both reed switches 11 and 12 are opened and closed by vertical movement of a permanent magnet 10, and one end of each is grounded through a float guide 8.

Reference numeral 13 denotes a control circuit which can be connected to a power source 18 via a switch 17, and is connected to the other end of a reed switch 11.12, so that the signal from this reed switch 11.12 is used as an input signal.

The output terminal of the control circuit 13 is connected to one end of the coil of the electromagnet 14, and when the lower limit reed switch 11 detects that the fuel level in the float chamber 7 has reached the lower limit liquid level, the electromagnet 14 is energized, and normally When the needle 15 that closes the opening of the fuel pipe 2 is driven to supply fuel from the fuel pump 4 to the float chamber 7, when the upper limit reed switch 12 detects that the fuel level has reached the upper limit. The power supply to the electromagnet 14 is cut off, the opening of the fuel pipe 2 is closed by the needle 15 and the spring 16, and the supply of fuel is stopped.

Reference numeral 19 denotes a main nozzle of the carburetor from which the fuel in the float chamber 7 is ejected, and is opened at a venturi portion 20 of the carburetor, the amount of which is ejected is determined by the opening degree of the throttle valve 21 of the carburetor.

22 is an air vent that opens upstream of the venturi portion 20 of the carburetor and introduces the pressure of the opening into the float chamber 7; 23 is an intake pipe whose downstream side communicates with the combustion chamber of the engine 24; The upstream side thereof communicates with an air cleaner 26 equipped with an air filter 25.

In the above configuration, the float 9 to which the permanent magnet 10 is fixed, the reed switch 11.12, the control circuit 13, the electromagnet 14, the needle 15, and the spring 16 form a fuel supply control mechanism that controls the supply of a fixed amount of fuel intermittently. .

Further, the output terminal of the control circuit 13 is connected to a fuel amount calculation circuit 30, and this fuel amount calculation circuit 30 is further connected to a switch 17.
The power supply 18 is connected to the power supply 18 through the power supply 18, and further directly connected to the power supply 18.

FIG. 2 shows a detailed configuration of the control circuit 13 shown in FIG. 1, in which 50 is a terminal connected to the power supply 18 via the switch 17, 51 is a constant voltage circuit that adjusts the power supply voltage, 52 is a terminal connected to the lower limit reed switch 11, 53 is a terminal connected to the upper limit reed switch 12,
54 is an inversion circuit that inverts the signal from the lower limit reed switch 11, and 55 is an inversion circuit that inverts the signal from the upper limit reed switch 12.
The output of is connected to the input of NAND gate 56, and terminal 5
2.53 is connected to the NAND gate 57.

NAND game) 56.57 output is R-S Friflo 5
The output of this R-S flip-flop 58 is connected to an amplifier circuit 59.

The output of this amplifier circuit 59 is connected to the coil of the electromagnet 14, a diode 60 for extinguishing the back electromotive force generated in the coil, and a protective resistor 61, and is connected to a terminal 6 at one end of the resistor 61.
2 is connected to the fuel amount calculation circuit 30.

Next, FIG. 3 shows a detailed configuration of the fuel amount calculation circuit 30 shown in FIG. The terminal 102 is connected to the terminal 62 of the control circuit 13 shown in FIG.

110 is a display constant voltage circuit that adjusts the power supply voltage; 120
130 is a cancel switch circuit for canceling memory retention; 140 is a terminal 62 of the control circuit 13 shown in FIG. 2;
150 is a needle 15 that shapes the output signal of the shaping circuit;
A CR oscillation circuit 160 counts the valve opening time of the needle 15 and generates a unit pulse every time the counted value becomes 1024 in this case and the fuel consumption reaches 0.011. 170 is an integrating circuit that integrates unit pulses generated from the counting circuit 160,
Circuit part number TC50 with built-in 4 decimal counters
01P integration element 171. Buffer 172, 173, 1
74.175°179, inverter buffer 176.1
It has 77.178.

180 is a display circuit that receives the output signal of the integration circuit 170 and displays the integrated value in 0.11 units;
It has three number display elements 181, 182, 183 that indicate digits, display element 181 displays 10 l units, display element 182 displays 11 units, and display element 183 displays 0.11 units, and emits point light. A flashing display is performed in synchronization with the output signal of the counting circuit 160, that is, a signal of 0.01 l in the section 184, and a decimal point is displayed in the dot light emitting section 185.

Next, the operation of the device of the present invention having the above structure will be explained with reference to the state explanatory diagrams in FIGS. 4A to 4D and the waveform diagrams of various parts in FIG. 5.

First, at time t-4o, when the engine 24 is started by closing a key switch (not shown), the switch 17 is also closed in conjunction with the key switch, and the power source 18 is connected to the control circuit 13 and the fuel amount calculation circuit 30. connected to.

Further, the fuel amount calculation circuit 30 is directly connected to the power source 18.

At this time, the position of the fuel liquid level in the float chamber 7 is usually
It is between the upper limit liquid level and the lower limit liquid level.

Therefore, as shown in FIG. 4A, the permanent magnet 10 provided integrally with the float 9 is located between the lower limit reed switch 11 and the upper limit reed switch 12, so the upper limit reed switch 12 remains closed and the lower limit reed switch 12 remains closed. The reed switch remains open.

Therefore, the terminal 52 of the control circuit 13 is at H level as shown in FIG. 5A, and the terminal 53 is at L level as shown in FIG.

Also, the amplifying circuit 59 is turned off, and its output becomes the fifth
As shown in the figure, the level is set to L, the electromagnet 14 is not energized, and the supply of fuel to the float chamber 7 is cut off.

Next, fuel is supplied from the main nozzle 19 to the engine 24, and when the fuel level in the float chamber 7 reaches the lower limit level at time 1=11, the permanent magnet 10 provided on the float 9 acts as shown in FIG. The lower limit reed switch 11 is closed as shown in FIG.

Therefore, both the terminals 52 and 53 of the control circuit 13 become L level, the R-S flip-flop 58 is inverted and the amplifier circuit 59 is turned on, and its output becomes H level as shown in FIG. Electromagnet 14 is energized.

The fuel tank 15 driven by the electromagnet 14 replenishes the float chamber 7 with fuel from the fuel tank 1.

As a result, the fuel level in the float chamber 7 rises, and the float 9 also rises, causing the permanent magnet 10 to move to the fourth position.
As shown in FIG. 7 will continue to be refueled.

Next, when the fuel level in the float chamber 7 reaches the upper limit level at time t=t3, the upper limit reed switch 12 is opened by the permanent magnet 10 provided on the float 9, as shown in the fourth diagram. Both terminals 52 and 53 of the control circuit 13 become H level, the R-S footflop 58 is inverted, the amplification circuit 59 is turned off, and its output becomes the fifth
As shown in the figure, the level is set to L, the electromagnet 14 is de-energized, and the replenishment of fuel into the float chamber 7 is stopped.

In this way, the control circuit 13 performs control so that as soon as the fuel in the float chamber 7 reaches the lower limit liquid level, the fuel is replenished from the fuel tank 1 to the upper limit liquid level.

The replenishment operation time t1 to t3 at this time is the fuel consumption time t.

It is much shorter than -11.

Incidentally, as shown in FIG. 5, the time points t-to' and t1'.

t2', t3', and further time points t-1o'', t1'', t1
'', t2'', and t3'', the control circuit 13
=to, t1. Control similar to the control at t2 to t3 is performed.

Therefore, the output terminal 62 of the control circuit 13 is connected to the input terminal 102 of the fuel amount calculation circuit 30 shown in FIG. 3, and the waveform is shaped by the shaping circuit 140.

This waveform-shaped signal is transmitted to inverters 151 and 152.
, 153, resistors 154, 155, and a capacitor 156, together with the output signal of the CR oscillation circuit 150 [Fig. Create a signal and send it to counting circuit 1
60 binary counter 162.

This binary counter 162 outputs a signal of 0.011 when the input pulse reaches a constant value (1024 in this embodiment).

This 0.011 signal is transmitted to the integrating element 171. buffer 17
2,173,174°175.179, and an inverter buffer 176.177.178, the frequency is further divided by 10 to form a unit pulse of 0.11, which is then integrated.

The signal integrated by this integration circuit 170 has 0.11 units sent to the inverter buffer 176, 11 units sent to the inverter buffer 177, and 101 units sent to the inverter buffer 1.
78, and these three signals are displayed on the display element 18.
It is displayed on a display circuit 180 consisting of 1°182.183.

Further, a blinking signal synchronized with the ON/OFF state of the output signal of the counting circuit 160, that is, the 0.01 l signal, is displayed on the dot light emitting section 184 via a buffer 179, and a decimal point is displayed on the dot light emitting section 185. indicate.

The display constant voltage circuit 110 is connected to the power supply 18 via a switch 17 that operates in conjunction with a key switch (not shown), and supplies its output constant voltage to the display circuit 180, so that when the switch 17 is closed, the display The circuit 180 is activated for display.

Further, the memory holding constant voltage circuit 120 is directly connected to the power supply 18 without passing through the switch 17, and supplies its output constant voltage to the counting circuit 160 and the integrating circuit 170, so that the counted value and integrated value are Even if the engine 24 stops and the key switch (not shown) is turned off and the switch 17 is opened, the memory is retained, and when the key switch is turned on again, the switch 1
7 is closed, an accurate display can be made immediately.

Furthermore, when the fuel tank 1 is refilled with fuel, the measurement value of the counting circuit 160 and the integrated value of the integrating circuit 170 are canceled and returned to zero by operating the canceling switch 130, and then the measurement according to the fuel consumption is performed again. can be done.

In the above-described embodiment, the display circuit 180 displays the amount of fuel consumed.
However, if the amount of fuel consumed exceeds a predetermined value, an alarm may be issued using a notification device such as a buzzer or a chime.

As described above, in the present invention, the solenoid valve is opened based on the electrical signals from the lower limit level sensor and the upper limit level sensor installed in the float chamber to replenish fuel in the float chamber, and the solenoid valve is opened. The valve opening signal with a certain time width is pulse-modulated with a clock signal of a predetermined frequency, and this modulated clock signal is counted to measure the amount of fuel consumed by the car's engine. Even if the opening time of the electromagnetic valve, that is, the corresponding amount of replenishment fuel varies depending on the running condition of the vehicle, the fuel can be measured with high accuracy.

[Brief explanation of drawings]

Fig. 1 is an overall configuration diagram showing an embodiment of the fuel meter according to the present invention, Fig. 2 is an electrical wiring diagram showing the detailed configuration of the control circuit in Fig. 1, and Fig. 3 is a calculation diagram showing the operation in Fig. 1. Electrical wiring diagrams showing the detailed configuration of the circuit, FIGS. 4A and 4B. C and D are schematic diagrams showing the positional relationship of the float with respect to changes in the fuel level in the float chamber, and FIG. 5 is a signal waveform diagram of the control circuit and arithmetic circuit to explain the operation of the device of the present invention. 1...Fuel tank, 7...Float chamber of the carburetor, 9°11.12...Float forming the main part of the liquid level sensor. Reed switch, reed switch, 13... control circuit, 14.15... electromagnet forming a solenoid valve,
Needle, 24...Engine, 30...
・Arithmetic circuit, 160...Counting circuit, 170,1
80...Integrator circuit 9 display circuit forming an arithmetic display circuit.

Claims (1)

[Scope of utility model registration request] an upper limit level sensor that is installed in a float chamber of a carburetor that supplies fuel to the engine and detects the upper limit liquid level position of the fuel in the float chamber; a lower limit level sensor that detects the lower limit liquid level position of the fuel in the float chamber; a solenoid valve for supplying and stopping fuel introduced into the float chamber; and a solenoid valve for opening the solenoid valve in response to an electric signal from the lower limit level sensor when the liquid level of the fuel in the float chamber reaches a lower limit liquid level. When fuel is supplied into the float chamber and the fuel level in the float chamber reaches an upper limit liquid level, the electromagnetic valve is closed by an electric signal from the upper limit liquid level sensor to stop the supply of fuel into the float chamber. A fuel measuring device for an automobile is equipped with a control circuit for stopping the vehicle and is configured to measure the fuel consumption of the automobile, wherein a valve opening signal having a duration for opening the solenoid valve is inputted from the control circuit. An automotive fuel measuring device comprising a fuel amount calculation circuit that pulse-modulates a lever opening signal with a clock signal of a predetermined frequency and counts the modulated clock signal to measure the amount of fuel consumed by the engine. .