JPH0775040B2 - Wireless liquid amount measuring device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a wireless liquid amount measuring device suitable for remotely managing the liquid level of an underground tank buried in a gas station or the like.

(Prior art) The amount of fuel oil or other liquid stored in an underground tank is usually managed by converting it into an electric signal by a float type level gauge and transmitting it to a monitor device such as an office via a transmission line. Has been done.

However, since the liquid level measuring device of the underground tank and the monitor device are connected by a transmission line, there is a problem in that wiring work in consideration of explosion proof is required and the facility costs.

In order to solve such a problem, the present applicant previously proposed a wireless liquid level measuring device that transmits data from the liquid level measuring means to a monitor device by radio waves. According to this device, wiring work can be eliminated.

(Problems to be Solved by the Invention) By the way, in the liquid level gauge used in such a wireless liquid level measuring device, a battery is used as a power source, so that unnecessary power consumption is avoided. , Is configured to transmit data at a time interval as long as possible according to an increase or decrease in the liquid level.

For this reason, when adjusting the liquid level gauge at the time of installation or when investigating the radio wave environment, the data transmission interval from the transmitter is long,
There is a problem that adjustment work takes time.

Of course, in order to solve such a problem, it is possible to select the measurement mode and the adjustment mode with a switch and to send the liquid level data in a short cycle by selecting the adjustment mode, but it is necessary to attach a switch. However, there is a possibility that the user may forget to set the switch to the measurement mode after the adjustment is completed, consume the battery in a short time, and cannot monitor the liquid amount in the underground tank.

The present invention has been made in view of such a problem, and an object of the present invention is to provide an adjustment mode that enables transmission to be performed at a time interval as short as possible during adjustment work such as installation. At the same time, another object of the present invention is to provide a new wireless liquid amount measuring device which can automatically switch to the measuring mode after the adjustment is completed.

(Means for Solving the Problem) In order to solve such a problem, in the present invention, while detecting the liquid level at regular intervals, when the liquid level increases, the liquid level is set to the time T1 sheet, and the liquid level When decreasing, the liquid level is set to T2
In the case of transmitting by radio wave every time (however, T1 <T2), when the measured data of the liquid level lower than the preset minimum reference liquid level is output, the transmission cycle T3 (however, T1> T3) ), The liquid level is continuously transmitted a prescribed number of times, and a means for returning to the measurement mode after the prescribed number of transmissions is provided.

(Function) At the time of installation or readjustment, the liquid level data of the underground tank is transmitted in a cycle as short as possible, the liquid level data is provided in a cycle convenient for adjustment work, and the transmission is completed a predetermined number of times. Then, by automatically shifting to the measurement mode, the mistake of mode switching is prevented.

(Example) Therefore, the details of the present invention will be described below based on an illustrated example.

FIG. 1 shows an embodiment of a liquid supply equipment to which the liquid amount measuring device of the present invention is applied. In the drawing, reference numeral 1 receives refueling of fuel oil by a lorry via a replenishment pipe 2. In the underground tank, a float type liquid level measuring device (not shown) is installed,
A transmitter 3 for transmitting the liquid level from here by radio waves is installed. Reference numeral 4 denotes a receiver installed in the office 5, and is configured to receive a liquid level signal from the transmitter 3 and display the liquid amount and the liquid level.

FIG. 2 shows an embodiment of the transmitting device 3 described above. In the figure, reference numeral 10 is a microcomputer constituting a control means, which supplies a voltage from a battery 11 via a voltage regulator 12 to a power supply terminal. 10a, also voltage regulator 12
Is activated, the activation signal from the timer means 13 is constantly supplied to the activation signal terminal 10b to shift to the operating state, while it is in a restartable state when stopped, that is, in a standby state. Reference numeral 13 denotes the above-mentioned timer means, which is configured to intermittently operate the microcomputer 10 by outputting a start signal at a constant cycle T0, for example, at intervals of 15 seconds.

Reference numeral 15 is a data storage means, which is supplied with an operating voltage at all times via a voltage regulator 12, and is provided with a liquid level measuring means 20 to be described later.
The liquid level data from is taken as the liquid level data F0 of the previous measurement, and the numerical value N to be described later is stored to execute the operation in the further adjustment mode. Therefore, it is lower than the minimum liquid level of the underground tank. Of the minimum reference liquid level Fx, the number of times Nx of continuous transmission, for example, 120 times, and the transmission cycle T3, for example, 5 seconds are stored.

A liquid level measuring means 20 responds to the vertical movement of the float F installed in the tank 1 and also has a voltage regulator 21.
Potentiometer 22 receiving the reference voltage via
And a voltage-frequency conversion means 23 for converting the output voltage from the potentiometer 22 into a frequency, which is supplied with electric power via the first switch 16 controlled by the microcomputer 10 to generate a frequency signal matching the liquid level. It is configured to output to the microcomputer 10.

Reference numeral 17 denotes a modulation transmission means, which receives power supply from the battery 11 via the voltage regulator 12 via the second switch 18 controlled by the microcomputer 10, and uses the measurement data of the liquid level measurement means 20 as a radio signal. It is transmitted from the antenna 19.

Next, the operation of the apparatus thus configured will be described based on the flow chart shown in FIG.

[Measurement Mode] When the battery 11 is set and power is supplied to the device, the microcomputer 10 stands by in a standby state in which only the function sufficient to receive the activation signal from the timer means 13 remains. The timer means 13 is constantly supplied with electric power to perform a time counting operation (step a), and when 15 seconds have elapsed from the start of the operation, outputs a start signal (step b) (fourth step).
Figure I). This causes the microcomputer 10 to leave the standby state and move to the operating state (step
C) The first switch 16 is turned on to supply operating power to the liquid level measuring means 20 (step d). The liquid level measuring means 20 is
The voltage output from the potentiometer 22 according to the liquid level is converted into a frequency signal by the voltage-frequency conversion means 23 and output to the microcomputer 10. The microcomputer 10 counts this frequency signal for a certain period of time to obtain the liquid level data F1 (step E) and turns off the first switch 16.
And turn off the power to the liquid level detection means 20 (step
F).

In this case, the normal measurement mode is set, so the number of transmissions Nx in the adjustment mode is “zero” (step), and is larger than the minimum reference liquid level data Fx (step), step (re). to go into.

The measured liquid level data F1 is compared with the previous liquid level data F0 stored in the data storage means 15 (step
Re).

(During non-replenishment) (Fig. 4 III) In this case, the fuel oil in the underground tank 1 is or is not consumed due to the liquid supply to the vehicle. F1 is smaller than or equal to the previous potential data F0 of the data storage means 15 (step S).

Since this is the first measurement, the numerical value N = 0 (step), and therefore the microcomputer 10
Sends the liquid level data F1 by turning on the second switch means 18 to actuate the transmission modulating means 17, and after finishing the transmission, turns off the second switch means 18 to stop the transmission (step
E). Next, the transmission interval, for example, "10" is set to the numerical value N (step W), and the liquid level data of the data storage means 15
F0 is updated with the liquid level data F1 measured this time, and the standby state is entered (step C). This allows the entire device to
Minimize power consumption by leaving only the minimum functions required for the next startup.

When the next activation signal is output from the timer means 13, the operations of steps (a) to (l) are executed as described above. In this case, since the numerical value N was set to "10" in the previous process and not "0" (step), the numerical value N is decremented by 1 (step yo), and the microcomputer 10 causes the modulation transmission means. The previous liquid level data F0 in the data storage means 15 is updated without activating 17, and the standby state is entered (step C).

This operation is repeated 10 times (Steps I ~ N,
(Le, Yo, Ka), when the number N becomes "0" (step
The microcomputer 10 turns on the second switch 18.
Then, the power is supplied to the modulation transmission means 17, and the liquid level data F1 just measured is transmitted. Then, the second switch 18 is turned off to suspend the transmission modulation means 17 (step E), and set the numerical value N to the transmission interval. Yes (Stepwa). Next, update the previous liquid level data F0 and move to the standby state (step
F) Repeat the above steps again.

Thereafter, the microcomputer 10 shifts from the standby state to the operating state every 15 seconds in this manner to activate the liquid level measuring means 20, and transmits the liquid level data every time such operation is repeated 10 times. As a result, it is possible to transmit the liquid level data necessary and sufficient for the liquid amount management when the fuel is not refueled while minimizing the power consumption.

(At the time of replenishment to the underground tank) (Fig. 4 II) The microcomputer 10 compares the obtained liquid level data F1 with the previous liquid level data F0 stored in the data storage means 15 (step). In this case, fuel oil flows from the lory to the underground tank 1 via the refueling pipe 2 and the liquid level is rising, so the liquid level data F1 measured this time is larger than the previous level data F0. It becomes (Step Nu).

Then, the microcomputer 10 turns on the second switch 18.
When turned on, the liquid level data F1 measured this time is transmitted, and after the transmission is completed, the second switch 18 is turned off and the modulation transmission means 17 is stopped (step E). After the transmission is completed, the numerical value N is set to "10" (step W), the liquid level data F0 of the data storage means 15 is updated with the measurement data F1 of this time, and the state returns to the standby state again (step C).

Thereafter, every time the standby state is changed to the operating state, the second switch 18 is turned on to activate the modulation transmission means 17, and the measured liquid level data F1 is transmitted.

[Adjustment Mode] (IV in FIG. 4) On the other hand, when the measuring device is newly installed or readjustment is performed, the float 7 of the liquid level measuring means 20 is drawn to a length equal to or less than the minimum reference liquid level data Fx. .

When the liquid level data F1 is input, the microcomputer 10 compares the minimum standard liquid level data Fx stored in the data storage means 15 with the measured liquid level F1 being lower than the minimum standard liquid level data Fx. Therefore, set 120 as the number of transmission times Nx without entering the measurement mode of (step) and step (). (Stepta).

In this way, the float F is returned to the normal state when the number of transmissions Nx is set.

The microcomputer 10 turns on the second switch 18 to transmit the liquid level data F1 from the liquid level measuring means 20, and after the transmission is completed, turns off the second switch 18 (step), and sets the number of transmissions Nx. "1" is subtracted from (step S). In this way, when the transmission cycle T3 = 5 seconds elapses (step), the process returns to step (d). Since the number of transmissions Nx is not “0” in the second and subsequent steps, the process jumps to the step (re) without entering the steps (h) and (t).
Repeat, and repeat).

As a result, the liquid level data F1 is transmitted in a cycle T3 = 5 seconds which is shorter than when the liquid amount is increased. Therefore, adjustment of the transmitting device such as the liquid level measuring means 20 and a receiving device (not shown), and further propagation. The condition can be easily investigated.

In this way, the transmission is repeated 120 times at 5-second intervals, and when the number of transmissions Nx becomes “0”, that is, when 10 minutes have elapsed (step), the measured liquid level data F1 and the minimum reference liquid Compare the level data Fx (sweep), and if the measured liquid level data F1 is larger, step (re).
The measurement mode is automatically entered.

On the other hand, when it is necessary to make adjustments and to transmit the liquid level data again in a short cycle, the float F is pulled out again and the liquid level data below the lowest reference liquid level data Fx is artificially measured.
It is possible to set a mode in which the liquid level data is continuously transmitted 120 times in a short transmission cycle T3 = 5 seconds by outputting the data from (step).

(Effect of the invention) As described above, in the present invention, while the liquid level is detected at fixed time intervals, the liquid level is increased every time T1 when the liquid level increases, and the liquid level is changed at the time T2 when the liquid level decreases. Every (however,
In the case of transmitting by radio wave at T1 <T2), when the measurement data of the liquid level lower than the preset minimum reference liquid level data is output, the transmission cycle T3 (where T1> T
In 3), the liquid level is sent continuously for the specified number of times. Therefore, at the time of installation or readjustment, the liquid level data of the underground tank should be sent at the shortest possible period to facilitate the adjustment work. Not only is it possible to perform the measurement, but also when the transmission is completed a predetermined number of times, the mode automatically shifts to the measurement mode, so it is possible to prevent accidents such as forgetting to switch to the measurement mode.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of a gas station to which the present invention is applied, and FIG.
FIG. 3 is a block diagram showing an embodiment of the transmitting device, and FIGS. 3 and 4 are a flow chart and a timing diagram showing the operation of the device shown in FIG. 1 ... Underground tank, 2 ... Supply pipe 3 ... Transmission device, 4 ... Reception device 5 ... Office, 11 ... Battery 17 ... Modulation transmission means, 19 ... Antenna 20 ... Liquid level measurement means

Claims (1)

[Claims] 1. A liquid level is detected at regular time intervals, while the liquid level is wirelessly increased every time T1 when the liquid level increases, and the liquid level wirelessly every time T2 (where T1 <T2) when the liquid level decreases. In the case of transmitting by radio wave, when the measurement data of the liquid level lower than the preset minimum reference liquid level data is output,
A wireless liquid volume measuring device having means for transmitting the liquid level continuously for a specified number of times in a transmission cycle T3 (where T1> T3), and automatically returning to the measurement mode after the specified number of times of transmission.