JPS643758B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a refueling control device for refueling vehicles such as automobiles with gasoline at a refueling station.
In particular, the present invention relates to a refueling control device that prohibits refueling when a refueling nozzle is not completely inserted into a vehicle's refueling port.

Various refueling devices have been known for a long time, but for example, ground-mounted ones are usually
When the refueling nozzle is removed from the nozzle hook, the motor for driving the refueling pump is automatically activated in response to this.

When the refueling pump operates, oil is pumped from the pump through the hose to the refueling nozzle, so that it is ready for refueling at any time. That is,
By inserting the refueling nozzle into the refueling port of an automobile, etc., and pulling the nozzle lever, refueling can be started immediately.

Therefore, if you accidentally pull the lever before fully inserting the fuel nozzle into the vehicle's fuel filler port,
Oil liquid may be scattered from the outlet of the oil supply nozzle, creating a risk of fire, explosion, accident, etc.

Furthermore, even after the refueling nozzle has been inserted into the refueling port and refueling has started, vibrations may cause the refueling nozzle to be inserted incompletely or come off, resulting in similar accidents. There is a risk of

Further, in this type of conventional refueling device, the motor is operated even while the refueling nozzle is inserted into the vehicle's refueling port after being removed from the nozzle hook, resulting in a disadvantage that a large amount of electric power is wasted.

In addition, refueling work is not dependent on the worker at the filling station.
Refueling is done by the driver of the vehicle being refueled - In so-called self-service refueling systems, refueling is performed directly by a person who is inexperienced with refueling, so before inserting the refueling nozzle into the refueling port, The probability of oil leakage due to incorrect operation increases.

Therefore, there is a need for a control means that reliably prevents the discharge of oil from the refueling nozzle until the refueling nozzle is securely inserted into the refueling port.

For this purpose, for example, a light amount detection means is attached to the tip of the refueling nozzle, and when the refueling nozzle is inserted into the refueling port of the vehicle, the amount of light in that part decreases. Conventionally, there has been proposed a refueling control device that detects whether or not the refueling nozzle is completely inserted into the refueling nozzle, and prohibits discharge of oil from the refueling nozzle while the refueling nozzle is not inserted.

An example of such a conventional oil supply control device is shown in FIG.

In the figure, Rin and Rout are photosensitive resistors such as photoconductors or photoelectric conversion elements made of a material whose resistance value changes depending on the amount of received light, and are connected in series with fixed resistors R1 and R2, respectively. These series circuits are connected to power supply E in parallel.

Therefore, the resistors R1, R2 and the photosensitive resistor
Rin and Rout constitute a bridge circuit.

In addition, Rin is irradiated with the light from the tip of the refueling nozzle via the light guide 11, and Rout is irradiated with the light from the tip of the refueling nozzle via the light guide 11.
2, the surrounding external light is irradiated. Therefore,
At the connection points A and B of the bridge, signal voltages are generated depending on the respective amounts of light.

The signal voltage at the connection points A and B is applied to the differential amplifier 1.
4. The opening and closing of the control contact 15 is controlled by the output of the differential amplifier 14. Control contact 1
5 is connected in series with a power supply 18 along with a nozzle switch 16 and a relay 17. Relay 17 controls power switch 20 of pump motor 1a.

During the refueling operation, when the refueling nozzle is removed from the nozzle hook, the nozzle switch 16 is closed. However, until the refueling nozzle is inserted into the vehicle's refueling port, the amount of light transmitted and irradiated to the photosensitive resistors Rin and Rout via the light guides 11 and 12 is approximately equal, and normally the resistance values of R1 and R2 are are chosen to be equal, so the signal voltages at points A and B will be approximately equal.

Therefore, the output of differential amplifier 14 is at a low level, control contact 15 is maintained open, and therefore relay 17 is not energized. For this reason, the pump motor 1a is also not driven, and even if the lever of the oil supply nozzle is pulled by mistake, no oil will be discharged.

When the refueling nozzle is completely inserted into the vehicle's refueling port, the amount of light irradiated onto the photosensitive resistor Rin through the light guide 11 becomes sufficiently small, so that its resistance value becomes large and occurs at point A of the bridge. The signal voltage increases. On the other hand, the signal voltage at point B hardly changes.

Therefore, the output of the differential amplifier 14 becomes high level, and the control contact 15 is closed. As a result, the relay 17 is energized, and the pump motor 1a
is driven, the oil is force-fed to the oil supply nozzle, and the oil is discharged from the nozzle to perform oil supply.

As mentioned above, according to the device shown in FIG. 1, as long as the refueling nozzle is not completely inserted into the vehicle's refueling port, even if the refueling nozzle is removed from the nozzle switch,
Since the oil is not discharged, accidents such as spilling or scattering of the oil outside the fuel tank of the vehicle can be prevented.

However, it has been found that the apparatus shown in FIG. 1 has the following drawbacks.

In other words, an inexpensive differential amplifier (comparator) that is commercially available and relatively easy to obtain.
has one of its inverting and non-inverting inputs OV
(ground potential) or the upper limit (drive) voltage, it tends to malfunction.

Therefore, point A in the bridge circuit of Fig. 1,
Considering the voltage at B, the voltage at each point Va,
Vb is expressed by the following formulas.

Va=Rin/R1+Rin×E Vb=Rout/R2+Rout×E The resistance value of a photosensitive resistor (for example, a photoresistor) is as small as 1KΩ in bright daytime, but
When it is completely dark, such as at night, it increases to about 10MΩ.

Therefore, at night, the resistance value of the photosensitive resistor Rin attached to the tip of the refueling nozzle increases to about 10MΩ, and the resistance value of the fixed resistor R1 increases by 10 to 20KΩ.
Even if it is selected, the voltage Va at point A will be almost close to the power supply voltage E, which will cause malfunction.

In order to avoid this, if the power supply voltage E is selected low, the voltage Vb at point B during bright daytime will become too low and approach OV, which will also cause malfunction.

The present invention has been made in view of the above circumstances, and its purpose is to ensure that the input voltage of a differential amplifier falls within a numerical range that makes its operation inaccurate, regardless of the brightness of the surrounding environment. An object of the present invention is to provide a refueling control device that can prevent this.

In order to achieve the above object, the present invention includes two light-sensitive resistors and two fixed resistors whose respective resistance values change depending on the tip of the refueling nozzle and other ambient light. A compensating resistor is inserted in series in the power supply circuit of the bridge, and the value of the compensating resistor is configured to change depending on the intensity of ambient light.

The present invention will be explained in detail below with reference to the drawings.

FIG. 2 is a schematic side view of the appearance of the oil supply control device to which the present invention is applied.

In the figure, 1 is a refueling machine, which is composed of a motor 1a, a pump 1b, a flow meter 1c, a pulse oscillator 1d, a refueling amount indicator 1e, a hose 1f, a nozzle hook 1g, a refueling nozzle 1h, a nozzle switch 1i, and a nozzle lever 1k. Ru.

Further, 2 is a control circuit for the motor 1a provided according to the present invention, Rin is a light-sensitive resistor provided at the tip of the refueling nozzle 1h, and Rout is a control circuit for the refueling machine 1 (generally used in the refueling machine 1) for detecting external light. Rcomp is a compensating photosensitive resistor whose resistance value changes depending on the intensity of external light.

Reference numeral 3 designates a vehicle to be refueled, 4 designates its fuel tank, and 5 designates a refueling port of the fuel tank 4.

FIG. 3 is an enlarged side view of the refueling nozzle 1h portion of FIG. 2, and the same reference numerals as in FIG. 2 represent the same parts. 1l is a lead wire for connecting the photosensitive resistor Rin to the control circuit 2.

FIG. 4 is a block diagram showing an example of the control circuit of FIG. 2, and the same reference numerals as in FIGS. 1 and 2 represent the same or equivalent parts.

R3 is a fixed resistor connected in series with the bridge driving power source E, and a photosensitive resistor Rcomp for external light compensation is connected in parallel with the resistor R3. 2
1 is a pulse oscillator, 22 and 23 are pulse counters, 24 and 25 are AND gates, 26 is an inverter, and 27 is a flip-flop.

During refueling operation, refueling nozzle 1h is connected to nozzle hook 1.
When the nozzle is removed from g, a signal indicating that the nozzle has been removed is output from the nozzle switch 1i, and the nozzle switch 16 is closed. At this time, the control contact 15 is open, as will be clear from what will be described later.

Until the refueling nozzle 1h is completely inserted into the fuel filler port 5 of the automobile, the difference between the brightness at the tip of the refueling nozzle 1h and the surrounding brightness is less than the set value. Photosensitive resistance Rin exposed to ambient light and photosensitive resistance Rin exposed to ambient light
The difference from the resistance value of Rout is less than the set value.

Therefore, points A and B of the bridge in Figure 4
The potential difference between points is also below the set value. Therefore, the output of the differential amplifier 14 is at a low level, the AND gate 24 is closed, and the AND gate 25 is open. The output pulses of the pulse oscillator 21 are supplied to the counter 23 via an AND gate 25.

When the counter 23 counts a predetermined number of pulses, it generates an output and the flip-flop is reset. However, as described above, since the control contact 15 is open at this time, the relay 17 remains unenergized.

When the refueling nozzle 1h is completely inserted into the refueling port, the brightness inside the refueling port 5 is sufficiently dark compared to the surrounding area, so the resistance value of the photosensitive resistor Rin is:
It is sufficiently larger than that of the external photosensitive resistor Rout.

As a result, a sufficiently large difference occurs between the potentials at points A and B on the bridge, and the output of the differential amplifier 14 becomes high level. This makes ANDGATE 2
4 is opened and AND gate 25 is closed.

The counter 22 counts the output pulses of the pulse oscillator 21 supplied via the AND gate 24, and produces an output when a predetermined value is reached. The output of the counter 22 is input to the set terminal of the flip-flop 27 to set it.

Therefore, the control contact 15 is closed, the relay 17 is energized, the power switch 20 is closed, and the motor 1a is started. Therefore, if the nozzle lever 1k is pulled in this state, oil liquid is discharged from the tip of the fuel supply nozzle 1h, and the fuel tank 4 is refueled.

If the refueling nozzle 1h falls out from the refueling port 5 during refueling, or if refueling is completed and the refueling nozzle 1h is pulled out, the initial state will return and the potential difference between points A and B of the bridge circuit will become smaller, causing the differential The output of the amplifier 14 becomes low level.

Therefore, AND gate 24 is closed and AND gate 25 is opened. When the counter 23 counts a set number of pulse signals supplied through the AND gate 25, the flip-flop 27 is reset by its output.

As a result, the control contact 15 is opened, the motor 1a is stopped, and refueling is prohibited. Therefore,
Even if the nozzle lever 1k remains pulled, the oil is completely prevented from being discharged from the oil supply nozzle.

However, as mentioned earlier in connection with the conventional example, when the refueling nozzle 1h is inserted into the refueling port 5 when the surroundings are sufficiently dark, such as at night, the resistance value of the light-sensitive resistor Rin at the tip of the refueling nozzle 1h exceeds the limit. As a result, the voltage at point A of the bridge becomes too high, which may cause the differential amplifier 14 to malfunction.

In order to prevent the above-mentioned malfunction, in the present invention, a compensating photosensitive resistor Rcomp and a fixed resistor R3 for voltage division are inserted in series with the bridge power supply E.
This prevents the voltage at point A from becoming too high.

The reason why the compensating resistor is a parallel resistor of the fixed resistor R3 and the photosensitive resistor Rcomp is as follows.

Assuming that only the fixed resistor R3 is connected in series with the power supply E, when the surroundings are dark, such as at night, the situation where the potential at point A rises too much is prevented, and malfunctions do not occur. However, when the surroundings are bright, such as in the daytime, the potential at point B drops too much and approaches OV, causing a problem in that the differential amplifier 14 is more likely to malfunction.

Therefore, it is necessary to use a compensating resistor that has a high resistance value when the surroundings are dark and a low resistance value when the surroundings are bright.

For this reason, in the present invention, as a compensation resistor,
A parallel circuit of fixed resistor R3 and photosensitive resistor Rcomp is adopted, and when the surroundings are bright, the photosensitive resistor
A compensation effect can be obtained depending on the value of Rcomp, and
When the surroundings are dark, a compensation effect can be obtained by changing the value of the fixed resistor R3.

In the above explanation, the motor 1a is controlled on/off by the relay 17, but instead of the motor 1a, the motor 1a and the pump 1b are used.
Clutch between pump 1b and oil supply nozzle 1h
It is obvious that the discharge of the oil from the oil supply nozzle 1h may be prohibited by controlling the shutoff valve or the like between then and when the relay 17 is not energized.

As is clear from the above description, according to the present invention, the differential amplifier (comparator) ) can be maintained at an appropriate value between OV and the upper limit value, and malfunction can be prevented even when using a commercially available inexpensive differential amplifier, so while ensuring reliable operation, A great effect can be achieved in that the cost can be reduced.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an example of a conventional refueling control device, FIG. 2 is a schematic side view of the external appearance of the refueling control device to which the present invention is applied, and FIG. 3 is an enlarged side view of the refueling nozzle portion of FIG. FIG. 4 is a block diagram showing an example of a control circuit in an embodiment of the present invention. 1...Refueling machine, 1a...Motor, 1b...Pump, 1
f...Hose, 1g...Nozzle hook, 1h...Refueling nozzle, 1i...Nozzle switch, 1k...Nozzle lever, 2...Control circuit, 3...Car, 5...Refueling port, 1
4... Differential amplifier, 15... Control contact, 16... Nozzle switch, 17... Relay, 20... Power switch,
21...Pulse oscillator, 27...Flip-flop,
Rin, Rout...photosensitive resistance, Rcomp...photosensitive resistance for compensation.

Claims (1)

[Scope of Claims] 1. A first light amount detection resistor disposed at the tip of the refueling nozzle, and a second light amount detection resistor disposed at a location other than the tip of the refueling nozzle where ambient light can be detected. , first and second fixed resistors connected in a bridge circuit together with the first and second light amount detection resistors, and a compensating resistor consisting of a photosensitive resistor whose resistance value decreases as the ambient light is brighter, a power supply connected to the bridge circuit; a comparison means supplied with an output electric signal of the bridge circuit; and a refueling device responsive to the output of the comparison means, when the output electric signal of the bridge circuit is below a set value. 1. An oil supply control device comprising means for prohibiting discharge of oil from a nozzle. 2. A first light amount detection resistor disposed at the tip of the refueling nozzle; a second light amount detection resistor disposed at a location other than the tip of the refueling nozzle where ambient light can be detected; A compensating resistor consisting of first and second fixed resistors connected in a bridge circuit together with a second light amount detection resistor, a light-sensitive resistor whose resistance value decreases as the ambient light is brighter, and a fixed resistor connected in parallel with the light-sensitive resistor. a power supply connected to the bridge circuit via a comparison means supplied with the output electric signal of the bridge circuit; 1. A refueling control device comprising: means for prohibiting discharge of oil from a refueling nozzle.