JPH03242517A - Measuring apparatus for liquid level - 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 [Field of Industrial Application] The present invention relates to a liquid level measuring device suitable for use in measuring the remaining amount, etc. in a liquid storage tank at a gasoline filling station, etc. .

[Prior Art] Generally, a liquid level measuring device is used at a gasoline filling station to measure the remaining amount in a tank at night, and is used to manage the remaining amount when replenishing gasoline, etc. As this type of liquid level measuring device, for example, one using a capacitance type liquid level sensor previously proposed in the present application is known (for example, Japanese Patent Laid-Open No. 14266/1983).

On the other hand, the liquid level measuring device has an upper limit alarm function that issues an alarm to call attention to overflow, etc. when the oil level in the liquid storage tank exceeds a preset height. Some devices are also known that have a lower limit alarm function that issues an alarm to prompt replenishment of the bend when the liquid level in the storage tank falls below a preset lower limit height. The upper limit warning function is particularly effective in preventing an overflow accident in which oil overflows from a pressure oil port when replenishing a liquid storage tank from a tank truck.

[Problem to be solved by the invention] By the way, when replenishing oil from a tank truck to a storage tank at night, what happens to the storage tank? It is known that ripples and bubbles occur on the liquid surface in the tank at night. Therefore, if you try to pour liquid into the storage tank until it is full, the liquid level in the storage tank will rise to a preset level due to the ripples or bubbles on the liquid level in the storage tank. The liquid level sensor may detect that the tank is full before reaching the specified upper limit height (height corresponding to the tank), and the upper limit alarm may occur intermittently or continuously.

However, when pouring liquid into the liquid storage tank until it is truly full, even if the upper limit alarm sounds, the worker must pay attention to the liquid level and continue working night shifts until the tank is full. In reality, the fact that the upper limit alarm is occurring continuously may make the alarm sound noisy.

If the upper limit alarm sound is too loud, some workers may cut off the charging source for the liquid level measuring device or turn off the power to the alarm. What if after the work is finished? There is a problem that the rear measuring device stops working.

The present invention was developed in view of the above-mentioned drawbacks of the prior art, and when the upper limit alarm is activated before the tank is truly full due to ripples or bubbles on the liquid level, the upper limit alarm is stopped and the tank is refilled. Even if I continue, what happens in the liquid storage tank? It is an object of the present invention to provide a return to normal position measurement device that can automatically restore an upper limit alarm function when the return to normal position has decreased.

[Means for Solving the Problems] In order to achieve the above object, the present invention includes a liquid level detecting means for detecting the liquid level in a liquid storage tank, and a liquid level detecting means for detecting the liquid level in the liquid storage tank, and a liquid level detecting means for detecting the liquid level in the liquid storage tank. What about the liquid level in the liquid storage tank? Yellow-white liquid level calculation means and the moat level? By yellow and white means? When the yellowed liquid level reaches the upper limit in the storage tank,
In the seventh night measurement device, the measuring device is equipped with a notification stop operation means for stopping the notification operation of the upper limit value by the notification means, and after the operation of the notification stop operation means, the liquid level, ii calculation is performed. It is determined whether the liquid level calculated by the means has reached a predetermined alarm return liquid level lower than the upper limit value (summer/sweeping liquid level determining means and the return liquid level determining means determine whether the liquid level in the liquid storage tank The two features are that the system is equipped with an alarm function return means that causes the alarm function of the upper limit value by the alarm means to return to a gigantic motion when it is determined that the liquid level has fallen below the return liquid level. By doing so, even if a worker who misunderstands that the above-mentioned alarm of the notification means is noisy and stops the operation of the notification means using the notification stop operation means (the summer return liquid level determination means is When it is determined that the liquid level has decreased to the return liquid level, the four means for restoring the notification function are dynamically restored, and the thinking means can be activated during the next replenishment operation.

[Embodiment 4''+] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In the drawing, 1 is an underground tank serving as a storage tank for storing oil 2, 3 is a measuring machine that refuels a vehicle with the oil sucked up through a suction pipe 4, and 5 is replenishing oil from a tank truck. The liquid injection pipe 6 is a liquid level sensor inserted into the underground tank 1 as a liquid level detection means, and the liquid level sensor 6 is, for example, a coaxial cylindrical capacitance sensor, and a coaxial cable is used as the liquid level sensor 6. It is connected to a control panel 8, which will be described later, via signal lines 7 such as .

Reference numeral 8 denotes a control panel installed, for example, in a gas station office, etc., and the control panel 8 includes a position calculation circuit 9, a display 10.
Upper limit 7 night setting device 11. Upper limit comparator 12, alarm return liquid level setting device 13. Recovery comparator 14 automatic recovery circuit 15. AND circuit 16. In addition to the alarm 17 and the like, it includes a lower limit liquid level setter and a lower limit comparator (none of which are shown).

here,? The rear arithmetic circuit 9 is connected to the liquid level sensor 6 via a signal line 7, and is connected to the liquid level sensor 6 via a signal line 7. The liquid level is determined based on the interelectrode capacitance formed in the repositioning sensor 6? It is yellowish white, and if the shape of the underground tank 1 is known in advance, it is possible to calculate the remaining amount. The liquidation value signal calculated by the liquid level calculation circuit 9 is output to the display 10 and displayed as the liquid level or remaining amount in the underground tank l.

Further, the upper limit liquid level setter 11 sets the upper limit liquid level data that can be refilled to the underground tank 1, and is set in advance as a unique value for the underground tank 1. Upper limit comparator 1
2 has its input side connected to the liquid level calculation circuit 9. It is connected to the upper limit liquid level setter 11 and outputs an upper limit value signal to the AND circuit 16 when the calculated value reaches the upper limit value.

On the other hand, predetermined data (for example, % liquid level) lower than the upper limit liquid level of the underground tank 1 is preset in the alarm return liquid level setting device 13 as the alarm return liquid level. The input side of the return comparator 14 is the liquid level calculation circuit 9. It is connected to the alarm return C rear setter 13, and outputs a return command signal when the calculated value drops to the return liquid level.

Further, the automatic reset circuit 15 is composed of a flip-flop circuit, and its set input terminal S is connected to a no-set switch 18, which will be described later, and its reset input terminal R is connected to the reset comparator 1.
The reset output terminal 0 is connected to the input side of the AND circuit 16. As a result, when the automatic reset circuit 15 operates the reset switch 18 and enters the set state, the automatic reset circuit 15 does not output a signal from the reset output terminals, and when the reset command signal is input from the reset comparison circuit 14, the reset output terminal A signal is output from Q to the AND circuit 16.

Further, the AND circuit 16 opens one gate only while a signal is input from the reset output terminal 0 of the automatic recovery circuit 15, and when the upper limit value signal is input from the upper limit comparator 12 in this state, a buzzer lamp etc. An alarm signal is output to the alarm 17 of the underground tank 1, and the alarm 17 notifies that the liquid level in the underground tank 1 has reached the upper limit.

Furthermore, 18 is a reset switch for stopping the upper limit alarm function, and this switch 18 is configured as a normally open trigger switch that closes only when it is pressed.

The reset switch 18 is provided at a position where it is easy to stop the upper limit alarm when pouring liquid from a tank truck, such as near the control panel 8 or near the underground tank 1.

The present embodiment is configured as described above, and its operation will be described next.

When the vehicle is repeatedly refueled by the weighing machine 3, the liquid level in the underground tank 1 decreases. At this time, the underground tank l
If the liquid level is below the set value by the alarm return liquid level setter 13, a return command signal is output from the return comparator 14 to the movement return/sweep circuit 15, and the AND circuit 16 opens one gate. . In this state, when the liquid level in the underground tank 1 reaches the lower limit value and a lower limit alarm is issued from the alarm 17, the filling station arranges for a tank truck and pours the soaked oil transported by the tank truck. It will be replenished from the liquid pipe 5.

In this way, the liquid level gradually rises due to the injection of liquid from the tank truck, the liquid level state is detected by the liquid level sensor 6, and the liquid level height is calculated by the limb position 7 calculation circuit 9. However, as mentioned earlier, even if you try to fill the liquid storage tank l until it is full, the liquid surface will ripple and bubbles will appear.
The liquid level sensor 6 detects the full tank before reaching the actual upper limit, and the liquid level calculating circuit 9 calculates the upper INN lrM level.

As a result, the upper limit comparator 12 compares the set value by the upper limit liquid level setter 11 with 7? ! An upper limit value signal is output to the AND circuit 16 from the calculated value from the position calculation circuit 9, and the alarm 17
will issue an upper limit alarm.

On the other hand, if the operator intends to turn the main unit on until the liquid storage tank 1 is truly full even if the upper limit alarm sounds, the operator must press the reset switch to stop the upper limit alarm from occurring.
Press 8. As a result, the automatic reset circuit 15 enters the set state, the output of the signal from its reset output terminal stops, the gate of the AND circuit 16 is closed, and even if the upper limit value signal is output from the upper limit comparator 12, the alarm 17 operation can be stopped.

Furthermore, as mentioned above, the liquid level in the underground tank 1 decreases, and the liquid level? When the l yellow-white value of the calculation circuit 9 becomes less than the set value by the alarm return liquid level setter 13, a return command signal is output from the return comparator 14 to the automatic return circuit 15, and the AND circuit 16 opens one gate. , the upper limit notification function by the notification device 17 can be automatically restored again.

Note that the alarm return liquid level setter 13 and the return comparator 14 are specific examples of the return liquid level determination means according to the present invention, and the automatic return circuit 15 and the AND circuit 16 are specific examples of the alarm function return means. The present invention is not limited to such circuit examples, but
It can also be realized in a program using a microcomputer.

Furthermore, the liquid level according to the present invention is a concept completely equivalent to night view or remaining amount, and is not limited to the liquid level in a narrow sense.

Furthermore, the notification means may be configured to provide audio notification using a voice synthesis circuit or the like.

【Effect of the invention〕

The liquid level measuring device according to the present invention is as described in detail above, and even if the upper limit alarm function is stopped by the notification operation stop means after the notification means has notified the upper limit value, the liquid level in the liquid storage tank remains unchanged. Since the upper limit alarm function of the above-mentioned notification means is configured to automatically return when the value reaches a predetermined return level lower than the upper limit value, the upper limit alarm is always issued during the next replenishment operation, thereby preventing the occurrence of overflow accidents. can do.

[Brief explanation of drawings]

The figure is a circuit configuration diagram showing an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Underground tank, 2... Oil level sensor, 6... Liquid level sensor, 8... Control panel, 9... Liquid level calculation circuit, 1
0...Display device, 11...Upper limit liquid level setting device, 12...
・Upper limit comparator, 13...Alarm return liquid level setting device, 14・
...Return comparator, 15...Automatic return circuit, 16...
AND circuit, 17... alarm, 18... reset switch.

Claims (1)

[Claims] A liquid level detecting means for detecting a liquid level in a liquid storage tank; a liquid level calculating means for calculating a liquid level in the liquid storage tank based on a detection signal from the liquid level detecting means; and a liquid level calculating means for calculating a liquid level in the liquid storage tank. When the liquid level calculated by reaches the upper limit value in the liquid storage tank, the liquid level measuring device is equipped with a notification means for notifying the upper limit value, and a notification for stopping the upper limit value notification operation by the notification means. a stop operation means; a return liquid level determination means for determining whether the liquid level calculated by the liquid level calculation means after operating the notification stop operation means has reached a predetermined notification return liquid level lower than an upper limit value; When the return liquid level determining means determines that the inside of the liquid storage tank has fallen below the return liquid level,
A liquid level measuring device characterized by comprising: a notification function return means for automatically returning the function of notifying the upper limit value by the notification means.