JPS59115300A - Controller for oil supply - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a refueling control device used when refueling a vehicle such as an automobile with gasoline at a refueling station, and particularly when the refueling nozzle is not completely inserted into the refueling port of the vehicle.
The present invention relates to a refueling control device that prohibits refueling.

Various types of refueling devices have been known in the past, but for example, ground-mounted ones typically respond to the removal of the -1 refueling nozzle from the nozzle hook and automatically operate the refueling pump drive system. The configuration is such that the motor is activated.

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 a refueling nozzle into a refueling port of an automobile or the like and pulling a lever on the nozzle, refueling can be started immediately.

Therefore, if you accidentally pull the lever before completely inserting the refueling nozzle into the vehicle's refueling port, oil liquid will be sprayed from the refueling nozzle's outlet, resulting in a fire, explosion, or accident. There is a danger.

Furthermore, even after the refueling nozzle has been inserted into the refueling port and refueling has started, the refueling nozzle may not be fully inserted or may come off due to vibrations, creating the same risk of accidents. There is.

Furthermore, in this type of conventional refueling device, the motor continues to operate while the refueling nozzle is inserted into the vehicle's refueling port after it is removed from the nozzle hook, so there are drawbacks such as high power consumption. .

In addition, refueling is performed by the driver of the vehicle being refueled, rather than by a worker at a refueling station.In so-called self-service refueling systems, refueling is performed directly by a person who is not familiar with refueling. Therefore, there is a high probability that an oil leak will occur due to an erroneous operation before the oil supply nozzle is inserted into the oil supply port.

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 fixed resistors R1 and Rout, respectively.
2 in series, and these series circuits are connected in parallel to power supply E.

Therefore, the resistors R1, R2 and the photosensitive resistor Rin,
ROut constitutes a bridge circuit.

Further, Rln is irradiated with light from the tip of the refueling nozzle via the light guide 11, and ROt+t is irradiated with surrounding external light via the light guide 12. Therefore, signal voltages are generated at the connection points A and B of the bridge in accordance with the respective amounts of light.

The signal voltages at the connection points A and B are supplied to a differential amplifier 14. The output of the differential amplifier 14 causes the control contact 15 to
is controlled to open and close. The control contact 15' is connected in series with the nozzle switch 16 and relay 17 to the power supply 18. The relay 17 is a power switch 20 for the pump motor 1a.
control.

During 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 R1 and R2
Since the resistance values of are chosen to be equal, the signal voltages at points A and B will be approximately equal.

Therefore, the output of the differential amplifier 14 is at low level,
Control contacts 15 are kept open and therefore relay 17 is not energized. For this purpose, the pump motor 1a
is not driven, and even if the lever of the refueling 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 is up. On the other hand, point B
The signal voltage hardly changes.

Therefore, the output of the differential amplifier 14 becomes high level,
Control contacts 15 are closed. By this, relay 17
Since the pump motor 1a is energized and the pump motor 1a is driven, the oil is pumped 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, oil liquid will not be discharged even if the refueling nozzle is removed from the nozzle switch. It is possible to prevent accidents such as spilling or scattering oil liquid outside the vehicle's fuel tank.

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

In other words, when either the inverting or non-inverting input of an inexpensive differential amplifier (comparator) that is commercially available and relatively easily obtained approaches OV (ground potential) or the upper limit (drive) voltage, It has characteristics that make it prone to malfunction.

Therefore, point A in the bridge circuit of FIG.

Considering the voltage of B, the voltage Va at each point.

vb is calculated by the following formula.

The resistance value of a photosensitive resistor (for example, a phototransistor) is as small as 1.0 Ω in bright daytime conditions, but increases to about 10 MΩ in darkness, such as at night.

Therefore, at night, the resistance value of the photosensitive resistor Rin attached to the tip of the refueling nozzle increases to about IOMΩ, and even if the resistance value of the fixed resistor R1 is selected to be between 10 and 20Ω, the voltage at point A Va is almost close to the power supply voltage E, which causes malfunction.

To avoid this, if you choose a low power supply voltage E,
OV occurs when the voltage vb at point B becomes too low during bright daytime
, which can also cause malfunctions.

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 connected in series when selected, and the fixed resistor The connection is configured to be selectively switched depending on the intensity of ambient light.

The present invention will be described 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, with a motor 1a1 and a pump 1b.
, flow meter 10, pulse oscillator 1d, oil supply amount indicator 1e,
It is composed of a hose 1f, a nozzle hook 1 (1), a refueling nozzle 1h, a nozzle switch 111, and a nozzle lever 1.

2 is a control circuit for the motor 1a provided according to the present invention, Rln is a photosensitive resistor provided at the tip of the refueling nozzle 1h, and Rout is a control circuit for the refueling nozzle 1 (generally used for detecting external light). This 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 11 portion of FIG. 2, and the same reference numerals as in FIG. 2 represent the same parts. 11 is a lead wire for connecting the photosensitive resistor R1n 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 and 23 are pulse counters, 24 and 25 are AND gates, 26 is an inverter, and 27 is a flip-flop.

R1 is a first fixed resistor connected in series with the photosensitive resistor Rin between the power supply VD and ground via the switching transistor Tr1. 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.

Furthermore, R3 and R4 are connected in series between the power supply V'D and the ground, and the connection point is a differential amplifier (comparator).
This is a voltage dividing resistor connected to the inverting input of No. 14. In addition,
A high potential side terminal (collector in the illustrated example) of the photosensitive resistor Rin is connected to a non-inverting input of the differential amplifier 14.

Here, the resistance values of the fixed resistors R1 to R4 and the resistance value of the photosensitive resistor Rin are such that the photosensitive resistor Rin is
When the differential amplifier 14 is inserted into the
When n is outside the fuel filler port 5, the inverting input of the differential amplifier 14 is selected to be smaller than the non-inverting input.

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

Here, the resistance values of the fixed resistors R5 to R7 and the resistance value of the photosensitive resistor ROut are such that when the surroundings are bright, such as during the day, the potential at point Q is smaller than the inverting input of the differential amplifier 40. , Conversely, when the surroundings are dark, such as at night, the input is selected to be larger than the inverting input of the differential amplifier 400.

Further, 35 is a latch circuit operated by the output of the nozzle switch 11.

During the refueling operation, when the refueling nozzle 111 is lined up from the nozzle hook 1q, the nozzle switch 11 outputs a signal indicating that the nozzle has been removed, and the nozzle switch 16 is closed. At the same time, the latch circuit 35
is activated. 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 vehicle switching transistor Tr1 will be conductive and the night switching transistor Tr2 will be cut off. the result,
A series circuit of the first fixed resistor R1 and the photosensitive resistor Rin is utilized, and the potential at the connection point P between the two is supplied to the non-inverting input of the differential amplifier 14.

On the other hand, if refueling is performed at night, the output j of the latch circuit 35 is at a high level, so 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 R1n is inserted into the fuel filler port 5, the inverting input of the differential amplifier 14 is turned off. is larger than the inverting input, and conversely, when the photosensitive resistor R111 is outside the fuel filler port 5, the differential amplifier 1
The inverting input of 4 is chosen to be smaller 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, and the output of the AND gate 24 is at a low level.
is open, and the AND gate 25 is open. Therefore, the output pulse of the pulse oscillator 21 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 inside of the refueling port 5 is sufficiently dark compared to the surrounding area, so the resistance value of the photosensitive resistor R1n is equal to that of the fixed resistor R1. It is large enough in comparison.

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 out of the refueling port 5 during refueling, or if refueling is completed and the refueling nozzle 1h is pulled out, the initial state returns and the potential at the connection point P becomes low, so the differential amplifier 14 The output becomes low level.

Therefore, AND gate 24 is closed and AND gate 2
5 opens. When the counter 23 counts the pulse signals supplied through the AND gate 25 to a set number, the flip-flop 27 is reset by the 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.

In addition, in order to prevent malfunction, AND gate 24.2
5 gives reset signals to the counters 23 and 22, respectively, and the counters are operated only when a predetermined number of pulse signals are continuously input to the counters from the AND gate.

The above description has been made regarding the case where refueling is carried out during the daytime, but the case is exactly the same when refueling is carried out at night. That is, in the case of nighttime, the only difference is that a series network consisting of the second fixed resistor R2, the night switching transistor Tr2, and the photosensitive resistor R1n 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 daytime is nighttime, a voltage signal corresponding to the instantaneous value of external light is supplied as the non-inverting input of the differential amplifier 4o.

For this reason, if the light-sensitive resistor Rout happens to be illuminated by a headlight or the like when refueling starts at night, there is a risk that it will be mistakenly recognized as daytime and malfunction will occur.

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 refer to the same or equivalent parts.

31 responds to the operation of the nozzle switch 11 to
32 is a differential amplifier whose non-inverting input is connected to the non-inverting input of differential amplifier 14; and 33 is an inverter that inverts the output of 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 the inverter 33 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 No. 32.

During the refueling operation, when the refueling nozzle 1h is removed from the nozzle hook 19, the nozzle switch 11 outputs a □ signal indicating that the nozzle has been removed, and the nozzle switch 16 is closed.

On the other hand, as soon as the nozzle switch 11 is activated, the timer 31 starts the scheduled time T1 (however, T1 is a shorter time than the time from removing the nozzle to inserting it into the fuel filler port 5).
Only a high level signal is output. As a result, the transistor Tr3 and the switching I/transistor Tr1 become conductive, and 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 differential amplifiers 14 and 32
The output is low level, and on the other hand, it is high level at night.

After the time T1 has elapsed, when the signal of the timer 31 falls to a low level, the latch circuit 35 is activated by the output of the inverter 33. Therefore, the latch circuit 35
The output is low level during the day and high level during the 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, when the output of the differential amplifier 32 is at a high level, for example at night, the differential amplifier 1
Since the output of 4 also goes high, the AND gate 24 is opened and the counter 22 operates, there is a risk that the flip-flop will be set to 1 during the aforementioned day/night discrimination operation and malfunction.

In order to prevent such malfunctions, the control circuit shown in FIG. 5 adds the output of the inverter 33 to the input of the AND GO 1 and 24, so that while the timer 31 is outputting a high level signal, -Close 1 to 24,
The pulse output of the pulse oscillator 21 is prevented from being supplied to the counter 22.

Note that although an example in which an independent differential amplifier 32 is added has been described above, the differential amplifier 32 and the voltage dividing resistor R8,
R9 may be omitted and the output of the differential amplifier 14 may be supplied to the latch circuit 35 instead.

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 momentary illumination from headlights or the like can be prevented.

If a control circuit like the one shown in Fig. 5 is used, it is possible to both distinguish between day and night and determine whether or not the refueling nozzle h is in the refueling opening with a simple structure that uses only one photosensitive resistor. Therefore, compared to the case shown in FIG. 4, 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 R2 are replaced by photosensitive resistors R1n
and the power supply VD, R2 can be short-circuited during the day, and R1 can be short-circuited during the night.

Furthermore, in the above explanation, the motor 1a is controlled on/off by the relay 17, but the motor 1a is
Instead of a, the clutch between the motor 1a and the pump 1b, the shutoff valve between the pump 1b and the fuel nozzle 1, etc. are controlled, and while the relay 17 is not energized, the flow from the fuel nozzle 1h is controlled. It is clear that the discharge of the oil liquid may be prohibited.

As is clear from the above explanation, according to the present invention, the differential amplifier (
The input voltage to the comparator can be maintained at an appropriate value between OV and the upper limit value, and even if a commercially available inexpensive differential amplifier is used, it is set so as to prevent malfunction, ensuring reliable operation. At the same time, 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 oil supply control device.
Fig. 2 is a schematic side view of the external appearance of a refueling control device to which the present invention is applied, Fig. 3 is an enlarged side view of the refueling nozzle portion of Fig. 2, and Fig. 4 is an example of a control circuit in an embodiment of the present invention. Block Diagram FIG. 5 is a block diagram showing another example of the control circuit in the embodiment of the present invention. 1...Refueling machine, 1a...Motor, 1b...Pump, 1f...Hose, 1g...Nozzle hook, 1h...
・Refueling nozzle, 11... Nozzle switch, 1k...
Nozzle lever, 2... control circuit, 3... automobile, 5
... Fuel filler port, 14.32.40 ... Differential amplifier, 1
5... Control contact, 16... Nozzle switch, 17...
... Relay, 2Q... Power switch, 21... Pulse oscillator, 27... Flip-flop, 31... Timer, 35... Latch circuit, Rin, ROut...
Photosensitive resistance representative patent attorney Michihito Hiraki and one other person] 8. Figure 1

Claims (1)

[Claims] (1) Pump the oil through the hose,
A refueling control device in a refueling station configured to discharge refueling from a refueling nozzle provided at the tip of the hose and supply the fuel to the refueling port of the vehicle, the device being disposed at the end of the refueling nozzle, and configured to control the refueling according to the amount of light received. A light amount detection resistor that changes electrical resistance, first and second resistors that are selectively connected in series with the light amount detection resistor to form a voltage dividing circuit, and a light outside the fuel filler opening of the vehicle (a) is set. means for selectively connecting the first resistor when the amount of light is greater than a set value, and selectively connecting the second resistor when the amount of light is less than a set value;
A refueling control device comprising means for prohibiting discharge of oil from a refueling nozzle when a partial voltage potential at a connection point between one of the resistors and the light amount detection resistor is within a predetermined range. .