JPS6350280B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a liquid supply device.

For example, in a refueling apparatus such as a gas station, a refueling nozzle is provided with a liquid level sensor to detect when a tank to be refueled is filled with oil, that is, a so-called "full tank". However, the prior art has the disadvantage that oil overflows when the liquid level sensor is malfunctioning because there is no device to check whether the liquid level sensor is operating normally.

For example, in the metering liquid supply device disclosed in Japanese Patent Application Laid-Open No. 51-123722, in order to prevent overflow due to failure of the flow rate pulse, a refueling start signal and a transmitter that outputs the signal based on the signal are used. The technology for checking for failures and performing standby for refueling operations is shown. However, in this known technique, a liquid level sensor must be provided when supplying liquid to a fuel tank of an automobile.
Therefore, unless the quality of the liquid level sensor is determined, it is not possible to prevent the liquid from overflowing. Conventional liquid level sensors are called negative pressure type, which generate negative pressure by the flow of liquid, but are normally in communication with the atmosphere, and when the liquid level rises, the atmospheric communication hole is blocked by the liquid level. The valve is then closed by negative pressure. Therefore, it was not possible to check in advance whether the negative pressure was generated or whether the closing mechanism was good or not. Recently, a photoelectric liquid level sensor has been developed. In this photoelectric liquid level sensor, the light receiving element receives light from the light emitting element, and the amount of light received changes as the liquid level rises, so the liquid level is detected based on the change in the amount of received light. I'm starting to do that.

When determining whether the liquid level sensor is operating properly, it is not possible to detect whether the liquid level sensor is operating properly or not based on changes in the amount of light received by simply using the transmitting means.

Also, for example, in US Pat. No. 3,662,924,
A technique is disclosed in which a light beam is transmitted to a predetermined position in a liquid emitted from a remote light source within a container, and the light beam is reflected and received, thereby manually or automatically terminating or restarting liquid supply. has been done. However, even with such known technology, if the optical liquid level sensor fails, it must be visually observed, and it is not possible to determine whether the optical liquid level sensor has failed or not.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a liquid supply device that can easily detect and determine a failure of an optical liquid level sensor before the liquid supply operation of the liquid supply device.

According to the present invention, a pump and a flowmeter are provided between the flow path between the oil storage tank and the oil supply nozzle, a fuel supply amount display meter connected to the flowmeter is provided, and the fuel supply nozzle is provided with an optical liquid including a light emitting part and a light receiving part. In a liquid supply device equipped with a surface sensor, there is provided a blinking means for blinking the light emitted from the light emitting section, a conversion means for converting the light reception state from the light receiving section into a pulse signal, and a pulse signal of the light reception state corresponding to the blinking of the light emitting section. A discriminating means for discriminating whether or not the present invention corresponds to the above, and a refueling control means for permitting refueling when the discriminating means determines that the vehicle is compatible and disallowing refueling when determining that the vehicle is not compatible.

The light emitting element, for example a light emitting diode, is therefore blinked by means of a blinking means, for example an oscillator. On the other hand, a light receiving section, such as a phototransistor, receives the blinking of the light emitting element.

The light receiving state of the light receiving section is converted into a pulse signal by a sensor circuit including a converting means, for example a comparator. This light reception signal becomes a pulse signal when there is no liquid or bubbles, that is, when it is operating normally in the air, and when liquid or bubbles are detected, it is not a pulse signal due to light scattering, but a high level signal (Hi ). Therefore, the determining means can detect that the tank is "full" by determining the pulse signal during normal operation and the high level signal during liquid level detection. In other words, if a pulse signal is generated from the light receiving element before refueling, it can be seen that the liquid level sensor is operating normally.

In addition, if a hand switch is provided on the refueling nozzle and a low level signal (Lo) is output by pressing the hand switch, it is possible to identify other tasks, such as hanging the refueling nozzle on the nozzle hook,
The same judgment as when disconnecting the hose can be made and used to reset the indicator or raise or lower the hose.

Since the blinking state of the blinking means is known in advance,
The discriminating means, for example, the discriminating circuit, can easily compare the light reception signal, which is the pulse signal, with the blinking state of the blinking means. Therefore, if the correspondence is correct, for example, if the pulse intervals match, it is determined that they correspond, and the refueling control means, such as a valve control circuit or a motor control circuit, is controlled to permit refueling. However, if you do not do so, refueling will not be permitted.

Therefore, according to the present invention, a failure of the optical liquid level sensor can be easily detected and judged, so that it is possible to prevent the liquid from overflowing due to a failure of the optical liquid level sensor, which is extremely desirable in terms of safety.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an oil supply system embodying the present invention, in which oil is sucked up from an underground tank (not shown) via a suction pipe R by a pump 2 driven by a motor 1, and from the pump 2. The discharged oil is supplied to an oil supply nozzle 5 through a flow meter 3 and a control valve 4. A liquid level sensor 6, which will be described later, is provided near the tip of the refueling nozzle 5, and a hand switch 7 is provided at the back of the refueling nozzle. The refueling nozzle 5 is hung on a nozzle hook 9, and when the refueling nozzle 5 is removed from the nozzle hook 9 for refueling, the nozzle switch SW is activated. Signals from liquid level sensor 6 and hand switch 7
The on/off signal is sent to the control device 1 via line L1.
It is input to 0. This control device 10 has a line L
A signal from the nozzle switch SW is inputted through the nozzle switch SW. Furthermore, the flow meter 3 converts the flow rate into a pulse signal by a pulse transmitter 3a,
The pulse signal is transmitted to the control device 1 via line L3.
Sent to 0. A pulse signal from the pulse transmitter 3a is sent from the control device 10 via a line L4 to display the amount of oil supplied on the display meter 11. The control device 10 controls the valve 4 via line L5 and also controls the motor 1 via line L6 in a manner described below. Further, the control device 10 sends a signal to the alarm 12 via a line L7 to issue an alarm, as will be described later.

Next, a specific example of the control device 10 implementing the present invention and its operation will be described with reference to FIGS. 2 and 3.

When the refueling nozzle 5 is removed from the nozzle hook 9, a signal is input from the nozzle switch SW to the sensor circuit 21, and the sensor circuit 21 starts operating. The liquid level sensor 6 is made up of a light emitting diode 6a and a phototransistor 6b as described later, and when a pulse signal as shown in FIG.
If there is no liquid but only air, an inverted pulse signal will be sent as shown in Figure 3B, and if liquid or bubbles are present, a high level signal will be sent as shown after point X in Figure 3C. When Hi is turned on and the hand switch 7 is turned on, a low level signal Lo shown after point Y in FIG. 3D is generated.

Therefore, when the refueling nozzle 5 is removed from the nozzle hook 9, there is only air at the liquid level sensor 6, so that the pulse signal shown in FIG. This discrimination circuit 2
When the pulse signal shown in Figure 3B is transmitted to 2,
The determination circuit 22 determines that the liquid level sensor 6 is not malfunctioning, and based on the signal from the determination circuit 22, the counting circuit 23 erases the previous oil supply amount stored in the memory.
Therefore, the indicator 11 returns to zero, a motor ON signal is sent to the motor control circuit 24 to drive the motor 1, and a valve opening signal is sent to the valve control circuit 25 to open the valve 4. The operator then opens the nozzle valve and performs the refueling operation. During the refueling operation, the pulse transmitter 3a converts the amount of oil supplied into a pulse signal, which is counted by the counting circuit 23, and the amount of oil supplied is displayed on the display meter 11.

When the tank is "full" or close to "full", the liquid level sensor 6 detects oil or its bubbles or splashes. As a result, a high level signal Hi is transmitted from the sensor circuit 21 to the discrimination circuit 22 as shown in FIG. 3C.
The discrimination circuit 22 discriminates this high level signal Hi,
The discrimination circuit 22 issues a valve close signal to the valve control circuit 25 and also issues a motor stop signal to the motor control circuit 24, so that the valve 4 is closed and the motor 1 is stopped. When the operator hooks the refueling nozzle 5 to the nozzle hook 9, the sensor circuit 21 stops its operation in response to a signal from the nozzle switch SW.

The above is a case where the liquid level sensor 6 was operating normally. However, if the liquid level sensor 6 is out of order, whether the cause is on the light emitting element side, the light receiving element side, or the sensor circuit, the sensor circuit 2
The signal sent from 1 to the discrimination circuit 22 is a signal other than the pulse signal shown in FIG. Therefore, when the refueling nozzle 5 is removed, the third
When a signal other than the pulse signal shown in FIG. Therefore, it can be seen that the liquid level sensor 6 is out of order.

When hand switch 7 is turned on, it outputs a low level signal.
Lo is sent to the discrimination circuit 22. This signal Lo can be used, for example, when you want to continuously refuel the next car without operating the nozzle switch SW, that is, without applying the refueling nozzle 5 to the nozzle hook 9.
It can be used as a reset signal to the counting circuit 23, or as a hose rise signal in the case of a hanging type refueling device, or as a signal for raising the hose. Note that although the above description has been made assuming that the valve 4 is controlled, the present invention can be practiced even if the pump 2 is controlled without providing the valve 4.

Next, one embodiment of the sensor circuit 21 will be described with reference to FIG.

In the illustrated embodiment, the liquid level sensor 6 includes a light emitting diode 6a and a phototransistor 6b. For example, the +5V bus line B is connected to the emitter of the transistor Tr, and the oscillator 30 is connected to the base of the transistor Tr. This oscillator 30 emits the pulse signal shown in FIG.
A pulse signal shown in FIG. 3A is generated at the collector of the Tr. This pulse signal is applied to the light emitting diode 6a via the resistor R1 and a known intrinsically safe explosion-proof barrier circuit 31, and the light emitting diode 6a emits a light pulse signal similar to that shown in FIG. 3A. The cathode side of the light emitting diode 6a is grounded E.
Note that the intrinsically safe explosion-proof barrier circuit 31 is a known circuit including a fuse F, a resistor R, and a Zener diode Z, so a description thereof will be omitted.

Now, the collector of the phototransistor 6b is connected to the above-mentioned bus line B via the resistor R2 and the intrinsically safe explosion-proof barrier circuit 31, and its emitter is grounded E.

Now, one input terminal of the comparator 32 for shaping the pulse signal into a rectangular wave is connected to the line between the resistor R2 and the phototransistor 6b.
The other input terminal T2 is connected between resistors R3 and R4 connected in series between the bus B and the ground E. These resistors R3 and R4 have the same resistance value, and the voltage at terminal T2 is half that of bus line B.
2.5V is applied.

When the light from the light emitting diode 6a reaches the phototransistor 6b as shown by the arrow a, the phototransistor 6b becomes conductive, so the terminal T1
The voltage will be 2.5V or less. Furthermore, if the phototransistor 6b does not receive light or the amount of light it receives is reduced due to oil or bubbles, the phototransistor 6b does not conduct, and the voltage at the terminal T1 increases. The voltage at terminal T1 is therefore inverse to the signal of oscillator 30. In response to this voltage change, the sensor circuit 21 sends a rectangular wave pulse signal T3 as shown in FIG. 3 to the discrimination circuit 22. hand switch 7
is connected in parallel with the phototransistor 6b, so when the hand switch 7 is turned on,
Terminal T1 will be grounded. Therefore, a low level signal Lo is issued from the comparator.

Next, an embodiment of the liquid level sensor 6 will be described with reference to FIGS. 5 and 6. The liquid level sensor 6 is provided at the tip of the discharge pipe 35 of the liquid supply nozzle 5.

FIG. 6 shows an enlarged view of the liquid level sensor 6 seen from the tip.

The liquid level sensor 6 is a light emitting part 6a (light emitting diode)
Consists of a light receiving section 6b (phototransistor),
Each has a lens on the front. In the case of a light emitting part, this lens is made in such a way that the light emitted from the light emitting part 6a passes through the lens 6a' and then when it exits into the air, it is refracted and becomes a parallel beam of light that emerges from the front. In contrast, parallel light rays are refracted by the lens 6b' and condensed onto the light receiving section 6b. Therefore, when the liquid level sensor 6 is in the air, all the light emitted from the light emitting section 6a reaches the light receiving section 6b and is electrically output as shown in FIG. 6A.

When the liquid level sensor 6 is in the liquid, the light emitted from the light emitting part 6a is not only blocked by the liquid's own light passage resistance as shown in FIG. As a result, the light is scattered in a direction different from that of the light receiving section 6b, and only a very small amount of light is received. Therefore, the electrical output of the light receiving section 6b becomes almost zero. As a result, as described above, the conditions in the air and in the liquid can be determined electrically.

As described above, since pulse signals are used in the embodiment shown in FIG. 4, three types of signals shown in FIG. 3 (b), (c), and (d) are obtained. Therefore, if the light-receiving element detects whether or not it receives light, it may be because the light-receiving element is malfunctioning, and the light may act as if the light has arrived even though it does not reach, and it may be judged as normal, or the light-emitting element may also be malfunctioning. Rather than judging it to be normal, it is judged to be normal as long as the pulse signal shown in Figure 3 B is generated when the refueling nozzle 5 is removed, and in other cases it is judged to be a failure, so it is judged as a failure. is certain.

As described above, a discrimination circuit is provided to detect the output from the liquid level sensor and confirm that it is normal before the liquid supply operation, and the liquid supply operation is performed based on the signal from the discrimination circuit. It is possible to check whether the liquid level sensor is malfunctioning at each time, and oil does not overflow during liquid supply work. Therefore, it is useful for preventing danger during liquid supply work.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing a refueling device embodying the present invention, Fig. 2 is a block diagram showing a control device embodying the present invention, and Fig. 3 A, B, C, and D each embody the present invention. Diagrams showing the oscillator signal in the device, the signal in the air, the signal when liquid or bubbles are present, and the signal when the hand switch is turned on. Fig. 4 is a wiring diagram showing an example of the sensor circuit. Fig. 5 The figure is a side view of a liquid supply nozzle embodying the present invention, FIG. 6A is an explanatory diagram showing the transmission of light in the air, and FIG. 6B is an explanatory diagram showing the transmission of light in the liquid. 6...Liquid level sensor, 6a...Light emitting element, 6b...
...Light receiving element, 21...Sensor circuit.

Claims (1)

[Claims] 1. A pump and a flow meter are installed between the flow path between the oil storage tank and the oil supply nozzle, an oil supply amount indicator connected to the flow meter is provided, and an optical liquid level sensor consisting of a light emitting part and a light receiving part is provided in the fuel supply nozzle. In the liquid supply device, a blinking means for blinking the light emitted from the light emitting section, a conversion means for converting a state of light reception from the light receiving section into a pulse signal,
A determining means for determining whether the pulse signal of the light receiving state corresponds to the blinking of the light emitting part, and if the determining means determines that the pulse signal corresponds to the blinking of the light emitting part, refueling is permitted, and if it determines that the pulse signal does not correspond, refueling is permitted. A fluid supply device characterized by being provided with a fuel supply control means that does not permit fuel supply.