JPS636438B2 - - 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.
In so-called self-service refueling systems, which are carried out by the driver of the vehicle receiving refueling, a person unfamiliar with refueling is directly 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 a photoconductor or a photoelectric conversion element made of a material whose resistance value changes depending on the amount of light received, 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 according to 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 phototransistor) is as small as 1KΩ in bright daytime, but increases to about 10MΩ in darkness such as at night. increase

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 a photosensitive resistor whose resistance value changes depending on ambient light, and two fixed resistors that are connected in series when selected. The connection is configured to be selectively switched 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. is a photosensitive resistor provided at an appropriate location (a location other than the tip of the refueling nozzle 1h).

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.

In the figure, 21 is a pulse oscillator, 22, 23
is a pulse counter, 24 and 25 are AND gates,
26 is an inverter, and 27 is a flip-flop.

R1 is a daytime switching transistor Tr1
is a first fixed resistor connected between the power supply VD and ground in series with the photosensitive resistor Rin. R2
is a second fixed resistor connected between the connection point P between the photosensitive resistor Rin and the transistor Tr1 and the power supply VD via the night switching transistor Tr2.

Further, R3 and R4 are voltage dividing resistors connected in series between the power supply VD and the ground, and whose connection point is connected to the inverting input of the differential amplifier (comparator) 14. Note that the high potential side terminal (collector in the illustrated example) of the photosensitive resistor Rin is connected to the differential amplifier 1.
4 non-inverting input.

Here, each resistance value of each fixed resistor R1 to R4 and the resistance value of the photosensitive resistor Rin are
is inserted into the fuel filler port 5, the differential amplifier 14
When the inverting input of the differential amplifier 14 is larger than the non-inverting input, and conversely, when the photosensitive resistor Rin is located outside the refueling port 5, the inverting input of the differential amplifier 14 is selected to be smaller than the non-inverting input. It can be done.

R5 and R6 are voltage dividing resistors connected in series between the power supply VD and ground, and whose connection point is connected to the inverting input of the differential amplifier (comparator) 40. R7 is a fixed resistor connected in series with the photosensitive resistor Rout, between the power supply VD and ground, and whose connection point Q is connected to the non-inverting input of the differential amplifier (comparator) 40.

Here, the resistance values of the fixed resistors R5 to R7 and the resistance value of the photosensitive resistor Rout are as follows:
When the surroundings are bright, the potential of point Q is the same as that of differential amplifier 4.
On the other hand, when the surroundings are dark, such as at night, the differential amplifier 4
It is chosen to be greater than the inverted input of 0.

Further, 35 is a latch circuit operated by the output of the nozzle switch 1i.

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 the same time, the latch circuit 35 is activated by the signal. At this time, the control contact 15 is open, as will be clear from what will be described later.

As is clear from the above, the output of the differential amplifier 40 is at a low level when the surroundings are bright, such as during the day, and becomes high level when it becomes dark, such as at night.

Therefore, if refueling is currently being performed during the day, the output of the latch circuit 35 will be at a low level, so the daytime switching transistor Tr
1 conducts, the night switching transistor Tr
2 is blocked. As a result, the series circuit of the first fixed resistor R1 and the photosensitive resistor Rin is utilized, and the potential at the connection point P between them is supplied to the non-inverting input of the differential amplifier 14.

On the other hand, if refueling is performed at night, the output of the latch circuit 35 is at a high level, so that the night switching transistor Tr2 becomes conductive and the daytime switching transistor Tr1 is cut off. As a result, the series circuit of the second fixed resistor R2 and the photosensitive resistor Rin is utilized, and the potential at the connection point P between them is supplied to the non-inverting input of the differential amplifier 14.

As described above, the resistance values of each of the fixed resistors R1 to R4 and the resistance value of the photosensitive resistor Rin are such that when the photosensitive resistor Rin is inserted into the fuel filler port 5, the inverting input of the differential amplifier 14 is turned off. The inverting input of the differential amplifier 14 is selected to be smaller than the inverting input, and conversely, when the photosensitive resistor Rin is located outside the fuel filler port 5, the inverting input of the differential amplifier 14 is selected to be larger than the non-inverting input.

Therefore, until the photosensitive resistor Rin (located at the tip of the refueling nozzle 1h) is completely inserted into the refueling port 5, 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. Therefore, the pulse oscillator 21
The output pulse is supplied to the counter 23 via the AND gate 25.

When the counter 23 counts a predetermined number of pulses, it generates an output and the flip-flop 27 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 5, the brightness inside the refueling port 5 is sufficiently dark compared to the surrounding area, so the resistance value of the photosensitive resistor in is compared to that of the fixed resistor R1. becomes large enough.

As a result, the output of the differential amplifier 14 becomes high level. As a result, AND gate 24 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 off from the refueling port 5 during refueling, or if refueling is completed and the refueling nozzle 1h is pulled out, the original state will be restored and the connection point P
Since the potential of the differential amplifier 14 becomes low, the output of the differential 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, oil is completely prevented from being discharged from the oil supply nozzle.

In order to prevent malfunctions, reset signals are given to the counters 23 and 22 from the AND gates 24 and 25, respectively, so that the reset signals are activated only when a predetermined number of pulse signals are continuously input from the AND gates to the counter. There is.

The above description has been made regarding the case where refueling is performed during the daytime, but the same applies to the case where refueling is performed at night. That is, in the case of nighttime, the second fixed resistor R2, the night switching transistor Tr2, and the photosensitive resistor
The only difference is that a series network consisting of Rin is selected, and the operations below the differential amplifier 14 are exactly the same.

Furthermore, in the above description, when the differential amplifier 40 determines whether it is daytime or nighttime, a voltage signal corresponding to the instantaneous value of external light is supplied as the non-inverting input of the differential amplifier 40. For this reason, if a headlight or the like happens to shine on the photosensitive resistor Rout when refueling starts at night, there is a risk that it will be mistakenly recognized as daytime and malfunction.

As a solution to this problem, for example, an integrating circuit can be inserted between the point Q and the non-inverting input, and the determination as to whether it is daytime or nighttime can be made based on the average value over a certain time.

FIG. 5 is a block diagram showing another example of the control circuit of FIG. 2, and the same reference numerals as in FIG. 1, FIG. 2, and FIG. 4 represent the same or equivalent parts.

31 responds to the operation of the nozzle switch 1i,
A timer 32 outputs a high level signal for a scheduled time T1, and its non-inverting input is connected to a differential amplifier 14.
The differential amplifier 33 connected to the non-inverting input of the timer 31 is an inverter that inverts the output of the timer 31. Further, 35 is a latch circuit that is controlled by the output of the inverter 33 and latches the output of the differential amplifier 32 when this becomes high level. R8 and R9 are connected in series between the power supply VD and the ground, and This is a voltage dividing resistor that determines the reference potential level of the inverting input of the dynamic amplifier 32.

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.

On the other hand, as soon as the nozzle switch 1i is activated, the timer 31 starts the scheduled time T1 (however, T1
A high level signal is output for a time shorter than the time from when the nozzle is removed to when it is inserted into the fuel filler port 5). As a result, the transistor Tr3 and the daytime switching transistor Tr1 become conductive.
The night switching transistor Tr2 is cut off.

Since the photosensitive resistor Rin has not yet been inserted into the fuel filler port 5, it is in a state of receiving external light.
Therefore, during the daytime, the outputs of the differential amplifiers 14 and 32 are at low level, and on the other hand, at night, the outputs are at high level.

After the time T1 has elapsed, when the signal of the timer 31 falls to a low level, the output of the inverter 33 activates the latch circuit 35. Therefore, the output of the latch circuit 35 is at a low level during the day and at a high level at night.

In this way, as described in connection with FIG. 4, daytime and nighttime discrimination is performed, and the first and second fixed resistors R1 and R2 are selectively connected. The subsequent operations are exactly the same as in the fourth case.

However, as it is, for example at night,
When the output of the differential amplifier 32 becomes high level, the output of the differential amplifier 14 also becomes high level,
Since the AND gate 24 is opened and the counter 22 operates, there is a risk that the flip-flop will be set and malfunction during the above-mentioned day/night discrimination operation.

In order to prevent such malfunctions, in the control circuit shown in FIG. 5, the output of the inverter 33 is added to the input of the AND gate 24, so that while the timer 31 is outputting a high level signal, the AND gate is 24 is closed to prevent the pulse output of the pulse oscillator 21 from being supplied to the counter 22.

Although an example in which an independent differential amplifier 32 is added has been described above, the differential amplifier 32 and the voltage dividing resistors R8 and R9 are omitted, and the output of the differential amplifier 14 is supplied to the latch circuit 35 instead. You can do it like this.

Also in this case, if the potential at point P is integrated over an appropriate time and supplied to the differential amplifier 32 (or 14), malfunctions caused by instantaneous illumination from a headlight or the like can be prevented.

If a control circuit like the one shown in Fig. 5 is used, it has a simple structure that uses only one photosensitive resistor, and it is possible to both distinguish between daytime liquid and whether or not the refueling nozzle h is in the refueling port. The fourth
Compared to the case shown in the figure, the circuit can be further simplified, reliability can be improved, and costs can be reduced.

Note that in both FIG. 4 and FIG. 5, selective switching of resistors R1 and R2 can also be realized by other circuit configurations. For example, resistors R1 and R
2 is connected in series between the photosensitive resistor Rin and the power source VD, R2 can be shorted during the day, and R1 can be shorted during the night.

Furthermore, in the above explanation, the motor 1a is controlled on and off by the relay 17, but instead of the motor 1a, a clutch between the motor 1a and the pump 1b, and a refueling nozzle 1h from the pump 1b are used. 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 the drawing]

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 one example of a control circuit in an embodiment of the invention, and FIG. 5 is a block diagram showing another example of a control circuit in an embodiment of the invention. 1...Refueling machine, 1a...Motor, 1b...Pump, 1f...Hose, 1g...Nozzle hook, 1h
...Refueling nozzle, 1i...Nozzle switch, 1k
... Nozzle lever, 2 ... Control circuit, 3 ... Car, 5 ... Fuel filler port, 14, 32, 40 ... Differential amplifier, 15 ... Control contact, 16 ... Nozzle switch, 17 ... Relay, 20...Power switch, 2
1...Pulse oscillator, 27...Flip-flop, 31...Timer, 35...Latch circuit,
Rin, Rout...Photosensitive resistance.

Claims (1)

[Scope of Claims] 1. Refueling control at a refueling station in which oil is pumped through a hose and discharged from a refueling nozzle provided at the tip of the hose to refuel the vehicle's refueling port. The device comprises: a light amount detection resistor disposed at the tip of the refueling nozzle and whose electrical resistance changes depending on the amount of light received; and a second resistor, each of which is selectively connected in series with the light amount detection resistor to form a voltage dividing circuit. means for selectively connecting the first resistor when the amount of light outside the fuel filler opening of the vehicle is greater than a set value, and selectively connecting the second resistor when the amount of light is smaller than the set value; a comparator that compares a divided voltage at a connection point between one of the first and second resistors and the light amount detection resistor with a reference potential; 1. A refueling control device comprising means for prohibiting discharge of oil from a refueling nozzle when the oil pressure is within a predetermined range.