JP2007271364A - Liquid level detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid level detector, that simplifies a circuit structure of a liquid level detection part, and the structure simplified of a processing circuit processing a liquid level detection signal from the detection part, while performing abnormality detection on the detection part. <P>SOLUTION: This liquid level detector is equipped with the liquid level detection part 100 and a data processing part 103. The detection part 100 comprises n pieces of Hall elements H<SB>1</SB>to H<SB>n</SB>for sensing a magnet 18 mounted on a float 17 to output signals, and a shift register with n pieces of first flip-flops and one or more second flip-flops, connected serially thereto. The first flip-flops are preset, by sensing signals from corresponding the Hall elements, while the second flip-flops are insert-disposed at intervals of a prescribed number out of the first flip-flops and preset by a data delimiting signal. The detection part 100 serially outputs the outputs of the first and second preset flip-flops from the shift register, while the processing part 103 outputs a detection output of a liquid level position as a serial output outputted from the shift register. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a liquid level detection device that detects a liquid level.

Conventionally, for example, a liquid level detection device shown in FIG. 6 has been proposed as a liquid level detection device used for measuring the liquid level of large tanks installed in various plants and the water level of dams, reservoirs, rivers, and the like. 6, the liquid level detecting device includes n Hall elements H ₁ to H _n to sense the position of the liquid surface, the Hall element H ₁ to H _n connected to the n pieces of flip-flops F ₁ to F _n The liquid level detecting unit 700 having a shift register connected to be operated in order and the liquid level detecting unit 700 is controlled, and the position of the liquid level is determined based on the data signal from the shift register. A control unit 701 to detect and a display unit 702 for displaying the position of the liquid level based on the position information of the liquid level output from the control unit 701 are provided. The control unit 701 includes a controller 703 that controls the liquid level detection unit 700, an oscillator 704 that oscillates a pulse signal, and a counter 705 that counts the pulse signal.

The operation of the liquid level detection device configured as described above will be described. In FIG. 6, the liquid level detection unit 700 will be described below assuming that the Hall element H ₁ is positioned at the lowest level. The liquid level detection unit 700 detects the position of the liquid level when each Hall element H _{1 to} H _n reacts with a magnet attached to a float that floats on the liquid level.

As a detection procedure, first, a reset signal is output from the controller 703 of the control unit 701 to each of the flip-flops F _{0 to} F _n . Thus, the flip-flops F ₀ to F _n is a non-operating state is reset. However, the flip-flop F _n is activated immediately after reset.

Next, a pulse signal is output from the oscillator 704, and counting of the pulse signal is started by the counter 705. At this time, if the liquid level is not within the detectable range and all the Hall elements H _{1 to} H _n do not react to the magnetism of the magnet, the flip-flop F _n is in an activated state, so that other flip-flops F _{n-1 to} F ₀ are operated in order and a count end signal is output to the controller 703. The counter 705 ends the count by receiving the count end signal via the controller 703. The count value at this time is n + 1 because the flip-flop F ₀ to which the Hall element is not connected is provided.

On the other hand, when the liquid level is in the detectable range, for example, when the Hall element H ₃ outputs a sensing signal in response to the magnetism, it operates in order from the flip-flop F ₃ to which the sensing signal from the Hall element H ₃ is input. To do. That is, as shown in the timing chart of FIG. 7, the flip-flop F ₃ is preset by the input of the sensing signal. Therefore, the shift register of the liquid level detection unit 700, starting from the flip-flop F _3, then the flip-flop F ₁ from the flip-flop F ₂ followed, operates to forward to the flip-flop F _0, to the controller 703 The count end signal is output. The counter 705 ends the count by receiving the count end signal via the controller 703. At this time, the count value is three.

The controller 703 determines the position of the liquid level based on the value counted by the counter 705, and outputs the determined position information to the display unit 702. Then, the liquid level detection result is visually displayed on the display unit 702.
Japanese Patent Application Laid-Open No. 2004-257763

  However, the liquid level detection device described in Patent Document 1 has a structure that detects the position of the liquid level by scanning the state of each water level electrode one by one. In addition, a switching element such as a transistor is required as an interface for scanning, and the wiring form becomes complicated. In addition, since all the water level electrodes are scanned one by one and fed back to the control unit each time, the processing circuit on the control unit side becomes complicated.

  Further, in the liquid level detection device described in Patent Document 1, abnormality detection of the liquid level detection unit, for example, failure of the Hall element or flip-flop constituting the liquid level detection unit, or the sensitivity of the Hall element has decreased. Therefore, it cannot be determined whether or not the detection result by the liquid level detection unit is accurate. For this reason, there is a possibility that the position of the liquid level is erroneously recognized due to an abnormality in the liquid level detection unit.

  The present invention is for solving the above-described problems, and simplifies the circuit configuration of the liquid level detection unit and the processing circuit of the control unit that controls the liquid level detection unit, and also detects abnormality of the liquid level detection unit. An object of the present invention is to provide a liquid level detection device capable of performing the above.

  The liquid level detection device according to the present invention is a liquid level detection device that detects the position of the liquid level, and is arranged in a straight line, and senses a moving body that moves with a change in the position of the liquid level and outputs a sensing signal. A plurality of first level flip-flops arranged in a straight line corresponding to each of the plurality of liquid level sensing units and preset by a sensing signal from the corresponding liquid level sensing unit; And a shift register in which one or more second flip-flops inserted and arranged every predetermined number and preset by a data delimiter signal are connected in series. 1. A liquid level detection unit that serially outputs the output of the second flip-flop from the shift register, and the liquid output from the serial output that is output from the shift register. And a data processing unit for outputting a detection output of the position, characterized in that.

In the liquid level detection device according to the present invention, the liquid level detection unit connected to the first flip-flop disposed at one end of the first flip-flop row may be unidirectional with respect to the first flip-flop row. Detecting the passage of the moving body that has moved from and continuously outputting a detection signal, and when detecting the passage of the moving body moving from the direction opposite to the direction, the detection signal is turned off,
It is characterized by that.

  In the liquid level detection device according to the present invention, the moving body is a magnet, and the liquid level sensing unit is a magnetoelectric conversion element that outputs a sensing signal in response to a magnet that moves in accordance with a position fluctuation of the liquid level. It is characterized by that.

  In the liquid level detection device according to the present invention, the magnetic force of the magnet and the sensitivity of each of the magnetoelectric transducers are such that the distance between the magnet and each of the plurality of magnetoelectric transducers, and between the plurality of adjacent magnetoelectric transducers. When the magnet is positioned between the elements at both ends of the row of the magnetoelectric transducers, one or more of the magnetoelectric transducers are selected to output a sensing signal under the action of the magnet. It is characterized by that.

  The liquid level detection device according to the present invention is characterized in that the magnetoelectric conversion element is a Hall element.

  According to the liquid level detection device according to the present invention, in the liquid level detection device for detecting the position of the liquid level, each of the liquid level detection devices is arranged in a straight line and senses a detection signal by detecting a moving body that moves in accordance with the position change of the liquid level. A plurality of liquid level sensing units to be output and a plurality of first flip-flops arranged on a straight line corresponding to each of the plurality of liquid level sensing units and preset by a sensing signal from the corresponding liquid level sensing unit And a shift register in which one or more second flip-flops are inserted and arranged every predetermined number and are preset by a data delimiter signal and connected in series. From the liquid level detection unit that serially outputs the output of the first and second flip-flops from the shift register, and the serial output that is output from the shift register And a data processing unit for outputting a detection output of the serial liquid surface position. Thereby, compared with the conventional system which scans the state of a liquid level detection part one by one, the circuit structure of the data processing part which processes the data signal from a liquid level detection part can be simplified. Further, since the state of the liquid level sensing unit is not scanned one by one, a switching element for that is not necessary, and the circuit configuration of the liquid level detection unit can be simplified. Furthermore, since a predetermined number of data delimiter signals are inserted at regular intervals in the data signal read from the liquid level detection unit, the data processing unit detects abnormality of the liquid level detection unit from the read data signal. Can do.

  Further, according to the liquid level detection device of the present invention, the liquid level sensing unit connected to the first flip-flop disposed at one end of the first flip-flop row may include the first flip-flop row. When the passage of the moving body that has moved from one direction is detected and a detection signal is continuously output, and the passage of the moving body that has moved from the opposite direction is detected, the detection signal is turned off. Thereby, it can be detected that the moving body has moved out of a detection range in which the liquid level detection unit can detect the moving body.

  According to the liquid level detection apparatus of the present invention, the moving body is a magnet, and the liquid level sensing unit is a magnetoelectric conversion element that outputs a sensing signal in response to a magnet that moves in accordance with a position fluctuation of the liquid level. Yes, the magnetic force of the magnet and the sensitivity of each of the magnetoelectric conversion elements are based on the distance between the magnet and each of the plurality of magnetoelectric conversion elements, and the spacing between adjacent ones of the plurality of magnetoelectric conversion elements. Is selected between the elements at both ends of the row of magnetoelectric transducers so that at least one of the magnetoelectric transducers outputs a sensing signal under the action of the magnet. Thereby, the magnet which is a moving body can be detected with a predetermined number of magnetoelectric transducers. As a result, the sensitivity of each magnetoelectric conversion element can be detected based on whether or not a predetermined number of magnetoelectric conversion elements sense the magnet.

  According to the liquid level detection device of the present invention, since the magnetoelectric conversion element is a Hall element that is resistant to mechanical stress, shock, and vibration and is inexpensive, the manufacturing cost of the liquid level detection unit can be reduced. . Furthermore, since the Hall element is used as the magnetoelectric conversion element, the interval between the elements can be reduced, and the Hall element can be operated by the magnetic flux from one magnetic pole of the magnet. It can be detected with accuracy.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Embodiment 1)
FIG. 1 is a diagram illustrating a configuration example of a liquid level detection device according to the first embodiment. As shown in FIG. 1, the liquid level detection device according to the first embodiment includes a liquid level detection unit 100 that detects the position of the liquid level, a control unit 101 that controls the liquid level detection unit 100, and a liquid level detection unit. And a display unit 102 for displaying the position. The control unit 101 outputs a pulse signal and a reset signal for reading data from the liquid level detection unit 100, and processes the read data signal to determine the position of the liquid level and to detect an abnormality in the liquid level detection unit 100. And a data processing unit 103 having a function of outputting the liquid level position information to the display unit 102 and displaying the position of the liquid level.

  FIG. 2 is a diagram illustrating a configuration example of a liquid level detector to which the liquid level detection device according to the first embodiment is applied. The liquid level detection device according to the first embodiment is incorporated on a printed circuit board 12 accommodated in the liquid level detector 10. In the liquid level detector 10, the liquid level detection unit 100 incorporated in the printed circuit board 12 is connected to the control unit 101 via input / output lines L 1 to L 3 connected to the printed circuit board 12.

  Here, in the liquid level detector 10 to which the liquid level detection device according to the first embodiment is applied, both ends are closed by the flange 13, and the stand pipe 11 provided with the flange 14 connected to the tank is provided. It is attached via an attachment band 16. The flanges 13 at both ends of the stand pipe 11 attach and detach the float 17. The flange 14 is provided at the tank connection port of the stand pipe 11. In the stand pipe 11, a float 17 that can move in the stand pipe is provided. A magnet 18, which is a sensed member that is detected by the liquid level sensing unit 20 in the liquid level detection unit 100, is attached to the float 17. The float 17 moves along the stand pipe 11 between the flanges 13 as the liquid level changes.

  In the liquid level detector 10 configured as described above, the float 17 moves along the standpipe 11 in accordance with the position fluctuation of the liquid level, so that the sensed member 18 provided in the float 17 also moves. By detecting the position of the sensed member 18 by the liquid level detection unit 100, the position of the liquid level can be detected.

  The liquid level detection unit 100 includes n liquid level detection units that detect the position of the liquid level, and a shift resist that is configured by connecting a plurality of flip-flops so as to sequentially operate. In this shift register, n flip-flops connected to the liquid level sensing unit and a total of m + 1 flip-flops including a plurality of flip-flops that input data delimiter signals are connected so as to operate in order.

  Hereinafter, first, each liquid level detection unit of the liquid level detection unit 100 will be described. As the liquid level detection unit, any unit that can detect the position of the liquid level may be used, and a known unit using light, magnetism, ultrasonic waves, or the like can be used. However, position information suitable for digital processing is obtained. It is preferable to use a magnetoelectric conversion element that can be easily applied to the liquid level detector 10.

  Since the magnetoelectric conversion element outputs a sensing signal in response to magnetism, when the magnetoelectric conversion element is used as the liquid level detection unit, a magnet 18 is attached to the float 17 as a sensed member.

  Here, the magnetic force of the magnet 18 and the sensitivity of each magnetoelectric conversion element are always based on the distance between the magnet 18 and each magnetoelectric conversion element and the interval between each magnetoelectric conversion element. The sensor signal is selected so as to output a sensing signal. Thereby, the magnet 18 can be sensed by a predetermined number of magnetoelectric transducers.

  Examples of the magnetoelectric conversion element include a reed switch and a magnetoresistive element. FIG. 3 is a diagram illustrating a circuit configuration of the liquid level detection unit 100 when the reed switch RS is used as the liquid level detection unit. In this case, the reed switch RS is connected to the preset input terminal (PR bar) of the flip-flop F, and when the magnetism is sensed, that is, when the position of the liquid level is sensed, a sense signal is sent to the preset input terminal (PR bar). Is output. The liquid level detection unit of the present invention may be any unit that outputs a detection signal to the input terminal (PR bar) when the position of the liquid level is detected. A Hall element that is one of the conversion elements is particularly preferable.

  Unlike the reed switch, the Hall element does not have the disadvantage of being weak against mechanical stress, shock, and vibration, and is inexpensive, so that the manufacturing cost can be reduced by using the Hall element as a liquid level sensing unit. In addition, by using the Hall element, the liquid level detection unit 100 can be configured so that the Hall element is operated by the magnetic flux from the magnetic pole of one magnet by reducing the interval between the elements. It can be detected with accuracy.

In the first embodiment, a Hall element is used as the liquid level sensing unit for the above reason. Hereinafter, the configuration of the liquid level detection unit 100 when a Hall element is used as the liquid level detection unit will be described. The Hall elements H _{1 to} H _{n as the} liquid level sensing unit 20 are linearly arranged in a row along the longitudinal direction on the printed circuit board 12 of the liquid level detector 10 so as to respond to the magnet 18. Be placed. Each Hall element is connected to n flip-flops described later in a one-to-one relationship. Each Hall element is connected to a corresponding flip-flop via a preset input terminal (PR bar). When the magnet 18 is sensed, a sensing signal is output to the corresponding flip-flop. The hall element outputs a signal indicating either “0” or “1” as a sensing signal.

In the first embodiment, as shown in FIGS. 1 and 3, pull-up resistors R are provided in the respective hall elements H _{1 to} H _n . This is because if any of the Hall elements H _{1 to} H _n fails for some reason, the preset input terminal of the flip-flop connected thereto becomes indefinite, and the flip-flop may not operate in a forward direction. It is provided to eliminate such problems. That is, by providing the pull-up resistor R, even if any of the Hall elements H _{1 to} H _n fails, the flip-flop connected thereto can be put into an operating state and operated forward.

Further, as the liquid level sensing unit, a pull-up resistor R is not attached externally by using a built-in pull-up resistor or a FET output type (voltage output type) instead of the Hall elements H _{1 to} H _n. However, it can be configured to perform the same function. The Hall element of the present invention includes not only one that functions as a magnetic sensor for detecting the liquid level but also one with a built-in pull-up resistor.

Next, the flip-flop in the liquid level detection unit 100 will be described. Here, the following description will be made with the flip-flop F ₀ as the bottom stage and the flip-flop F _m as the top stage. In the first embodiment, as shown in FIG. 1, the flip-flops constituting the shift register are connected to the corresponding Hall elements (H _{1 to} H _n ) in a one-to-one relationship and arranged along the columns of Hall elements. N first flip-flops (F _{1 to} F ₅ , F _{9 to} F ₁₃ , F _m-2 ) and a predetermined number of first flip-flops are inserted and arranged to input a data delimiter signal One or more second flip-flops (F _{6 to} F ₈ , F _{14 to} F ₁₆ , F _m−1 , F _m ) and a third one that is arranged at one end of the flip-flop column and inputs a data delimiter signal Flip-flop (F ₀ ).

A configuration example of the first flip-flop will be described with reference to FIG. 4 by taking the flip-flops F _{1 to} F ₅ as examples. Each flip-prop is connected so that it can be operated forward. For example, connected to an output terminal Q of the preceding flip-flop F ₄ input terminal D of the flip-flop F ₃ via the output line L _9, an output terminal Q of the flip-flop F ₃ via the output line L ₈ is connected to the input terminal D of the subsequent flip-flop F _2, further flip-flop F ₂ is its output terminal Q is connected to an input terminal D of the subsequent flip-flop F ₁ through the input-output line L _7. Further, in each flip-flop, the clock input terminal CK is connected to the pulse signal output terminal T ₃ via the input / output line L ₆ , and the clear terminal (CLR bar) is connected to the reset signal output terminal T via the input / output line L _5. Connected to ₂ .

The second flip-flops F _{6 to} F ₈ and F _{14 to} F ₁₆ have preset input terminals (PR bars) connected to the ground or the power supply, and the flip-flops connected to the ground input the data delimiter signal “0”. The flip-flop connected to the power supply receives the data delimiter signal “1”. Further, the clock input terminal CK is connected to the pulse signal output terminal T ₃ via the input / output line L ₆ , and the clear terminal (CLR bar) is connected to the reset signal output terminal T ₂ via the input / output line L _5. Yes.

In addition, the second flip-flop F _m-1 has its preset input terminal (PR bar) connected to the power supply and inputs the data delimiter signal “1”. Further, the clock input terminal CK is connected to the pulse signal output terminal T ₃ via the input / output line L ₆ , and the clear terminal (CLR bar) is connected to the reset signal output terminal T ₂ via the input / output line L _5. Yes.

Further, the second flip-flop F _m has a preset input terminal (PR bar) and an input terminal D connected to the ground or a power source, and inputs a data delimiter signal. In FIG. 1, the preset input terminal (PR bar) is connected to the ground and the data delimiter signal “0” is input, and the input terminal D is connected to the power source via the input / output line L ₁₀ and the data delimiter signal “0” is input. Enter “1”. Further, the second flip-flop F _m is connected to an input terminal D of the flip-flop F _m-1 and the output terminal Q via the output line L _11, the clock input terminal CK is through the input-output line L ₆ Te is connected to the pulse signal output terminal T _3, a clear terminal (CLR bar) is connected to the reset signal output terminal T ₂ via the output line L _5.

As described above, in the first embodiment, three second flip-flops (F _{6 to} F ₈ , F _{14 to} F ₁₆ ) are provided every predetermined number (here, 5) in the first flip-flop column. ) Is arranged, and two second flip-flops (F _m−1 , F _m ) are arranged on the uppermost side, but one or more second flip-flops are arranged in the first stage. What is necessary is just to insert and arrange every predetermined number of flip-flops. In FIG. 1, data delimiter signals “1”, “0” and “1” are inserted for every five Hall elements. Therefore, in the liquid level detection unit 100, the data string of the data signal output from the shift register is the number of Hall elements in which “0” continues, regardless of the state of the sensing signal output from the Hall element. Since the number of Hall elements in which “1” is continuous + 2 or more does not continue, the data signal output from the shift register does not have 0 being 6 or more and 1 being 8 or more. Thus, by providing the second flip-flop for inputting the data delimiter signal, the upper limit of the number of data having the same value is determined. For this reason, when a data signal having the same value larger than the upper limit is read, the data of the portion where the Hall element is not connected is being read, or the liquid level detection unit 100 is in a normal state. It can be detected by the data processing unit 103.

The third flip-flop F ₀ has its preset input terminal (PR bar) connected to the ground or a power supply, and inputs a data delimiter signal. Although FIG. 1 shows the case where the preset input terminal (PR bar) is connected to the power source and the data delimiter signal “1” is input, the preset input terminal (PR bar) is connected to the ground and the data is input. It is also possible to input a delimiter signal “0”. In the lowest flip-flop F ₀ , the output terminal Q is connected to the data signal input terminal T ₁ via the input / output line L ₄ , and the clock input terminal CK is connected to the pulse signal output terminal via the input / output line L _6. The clear terminal (CLR bar) is connected to T ₃ and is connected to the reset signal output terminal T ₂ via the input / output line L ₅ .

As shown in FIG. 1, a third flip-flop (F ₀ ) for inputting a data delimiter signal may be arranged at the lowest stage of the flip-flop row. in 100, the flip-flop F ₀ is not always necessary. The case without the flip-flop F _0, since no lowermost data delimiter signal, continuous identical number of data readout range of the normal data is one less only the bottom.

  Here, the flip-flops arranged at one end of the row of flip-flops, that is, the flip-flops arranged at either the lowermost stage or the uppermost stage are preferably set so as to be activated immediately after reset. .

For example, when the uppermost flip-flop F _m is set so as to be activated immediately after resetting, the flip-flop even when all the Hall elements H _{1 to} H _n do not sense the position of the liquid level. since F _m is actuated state, data is output signal from the output terminal Q of the flip-flop F _m to the input terminal D of the flip-flop F _m-1, flip-flop F _m-1 is in operation. Even after the flip-flops F _{0 to} F _m are operated in order, when data is read, the value input from the input / output line L ₁₀ is continuously read.

The liquid level detection unit 100 configured as described above outputs a data signal from the shift register in accordance with the pulse signal output from the data processing unit 103 via the input / output line L ₅ . Data string of the data signal, the data separator signals D _x (X is 1 or 0), the data signal which the Hall element outputs a H _n, the case of FIG. 1, in order from the flip-flop F ₀ lowermost, _{D 1, H 1, H 2} , H 3, H 4, H 5, D 1, D 0, D 1, H 6, H 7, H 8, H 9, H 10, D 1, D 0, D 1 ,... H _n , D ₁ , D ₀ , D ₁ . In this way, the liquid level detection unit 100 outputs the signal from the Hall element and the data delimiter signal as a data signal of one data string in accordance with the pulse signal.

  Next, the data processing unit 103 that processes the data signal output from the liquid level detection unit 100 as described above will be described in detail. The data processing unit 103 stores in advance the position and interval of the data delimiter signal inserted into the data signal. For this reason, the data delimiter signal can be removed from the input data signal, the data string can be rearranged, and abnormality detection of the liquid level detection unit 100 can be performed. Then, the position of the Hall element that has output the sensing signal is determined from the rearranged data sequence, and the position information is output to the display unit 103. Thereby, the position of the liquid level sensed by the Hall element can be displayed on the display unit 103. Further, the data processing unit 103 can not only display the liquid level but also obtain the remaining amount of liquid from the position of the liquid level and display it on the display unit 103.

  Here, the magnetic force of the magnet 18 and the sensitivity of each Hall element are determined based on the distance between the magnet 18 and each Hall element and the interval between the Hall elements. When selected to output a sensing signal, the data processing unit 103 obtains an average value of the positions of the plurality of Hall elements that sense the magnet 18 and outputs the average value to the display unit 103 as position information. .

  Alternatively, the data processing unit 103 stores in advance the specific gravity of the liquid whose liquid level is to be measured, corrects the positional deviation of the float due to the specific gravity of the liquid, and outputs the corrected value to the display unit 103 as position information. good.

Next, the operation of the liquid level detection device according to the first embodiment configured as described above will be described. For example, the liquid level detector 10 is installed in a tank equipped with liquid supply and drainage equipment so that the Hall element H ₁ as the liquid level sensing unit is positioned at the lowest level. When the liquid is supplied to the tank and the liquid level rises, the float 17 floating on the liquid surface rises along the stand pipe 11 accordingly. On the other hand, when the liquid is discharged from the tank and the liquid level is lowered, the float 17 is lowered along the stand pipe 11 accordingly. The liquid level detection unit 100 reacts with the magnetism of the magnet 18 provided in the float 17 that moves in the stand pipe 11 as the liquid level moves up and down, so that H _{1 to} H _n-1 of each Hall element react. The position of the liquid level can be detected.

As a detection procedure, first, a reset signal is output from the data processing unit 103 to each of the flip-flops F _{0 to} F _n . Thus, the flip-flops F ₀ to F _n is inoperative reset. However, the flip-flop F _m is activated immediately after reset.

  Next, a pulse signal is output from the data processing unit 103, and a data signal is output from the shift register in response to the pulse signal, and the data processing unit 103 reads it.

At this time, in accordance with the pulse signal, the data signal is sequentially output from the shift register from the lowermost flip-flop F ₀ side. Data separator signals D _x (X is 1 or 0), the data signal which the Hall element outputs a H _n, the case of FIG. 1, data sequence, in order from the flip-flop F ₀ side, D _1, H _{1, H 2, H 3, H 4} , H 5, D 1, D 0, D 1, H 6, H 7, H 8, H 9, H 10, D 1, D 0, D 1, ··· H n , D ₁ , D ₀ , D ₁ . For example, in FIG. 1, when the Hall elements H _{2 to} H ₄ react to the magnet 18 to sense the liquid level and output the sensing signal “0”, the data string of the data signal is from the flip-flop F ₀ side. In order, 1, 1, 0, 0, 0, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1.

  Here, since the data processing unit 103 stores in advance the position and interval at which the data delimiter signal is inserted in the data string, whether the position of the data delimiter signal in the read data signal is the same as the prestored position. In addition, abnormality detection is performed by determining whether the number of consecutive data with the same value exceeds the number of normal ranges, that is, whether 0 is 6 or more and 1 is 8 or more. Furthermore, the sensitivity of the Hall element is detected depending on whether a predetermined number (three in this case) of Hall elements is detected by the magnet.

Next, the data processing unit 103, the position where the data delimiter signal is inserted is predetermined, from the read data signal by removing the value of the data delimiting signals, in order from the flip-flop F ₁ side, H _{1, H 2, H 3, H 4} , H 5, H 6, H 7, H 8, H 9, H to obtain a data signal of the data string of ₁₀ · · · H _n. For example, when the hall elements H _{2 to} H ₄ sense the liquid level in response to the magnet 18 and output “0” as the sensing signal, the obtained data string is ₁ , 0 in order from the flip-flop F ₁ side. , 0, 0, 1, 1, 1, 1, 1, 1,. Since the data signal is sequentially output from the flip-flop F ₁ side according to the pulse signal from the shift register, the position of the float 17 is determined by detecting the position of the Hall element that senses the magnetism of the magnet 18 based on the data string. it can. Here, since the Hall elements H _{2 to} H ₄ sense the liquid level, the data processing unit 103 obtains an average value of the positions of the Hall elements and uses the average value as position information to display the display unit. To 103.

Next, the display unit 103 visually displays the detection result of the liquid level based on the position information.
The liquid level detection apparatus according to the first embodiment can continuously detect the position fluctuation of the liquid level with high accuracy by repeatedly performing the above operation.

As described above, the liquid level detection device according to the first embodiment has a one-to-one correspondence with the plurality of Hall elements H _{1 to} H _n that sense the position of the liquid level and output a sensing signal, and the corresponding Hall elements. A plurality of first flip-flops to be connected, one or more second flip-flops that are arranged at regular intervals in a row of the first flip-flops and that inputs a data delimiter signal, and the first flip-flops A liquid level detection unit 100 having a shift register that is arranged at one end of the column and is connected so that a third flip-flop for inputting a data delimiter signal is operated in order, and an output from the liquid level detection unit 100 And a control unit 101 for processing the data signal to be processed. Thereby, the control part 101 can read the information of all the liquid level detection parts which sense the position of a liquid level as one data string by outputting a pulse signal to the liquid level detection part 100. Therefore, the liquid level detection device according to the first embodiment can simplify the configuration of the data signal processing circuit of the control unit 101 as compared with the conventional method of scanning the state of the liquid level sensing unit 100 one by one. . Further, since the state of the liquid level sensing unit 100 is not scanned one by one, a switching element for that is not necessary, and the circuit configuration of the liquid level detection unit 100 can be simplified. Furthermore, since a predetermined number of data delimiter signals are inserted in predetermined positions in the data signal read from the liquid level detection unit 100, the control unit 101 detects that the liquid level detection unit 100 is abnormal from the read data signal. Detection can be performed.

  Although the first embodiment has been described as using a magnetoelectric conversion element (Hall element) as the liquid level sensing unit, the present invention is not limited to this. For example, the liquid level sensing unit may be an element that senses light or ultrasonic waves and outputs a sensing signal. In this case, a member that generates light or ultrasonic waves is attached to the float 17 as a sensed member.

(Embodiment 2)
Next, the liquid level detection apparatus according to the second embodiment will be described with reference to FIG. FIG. 5 is a diagram illustrating a configuration example of the liquid level detection device according to the second embodiment.

  The liquid level detection device according to the second embodiment is connected to a flip-flop arranged at one end of the first flip-flop row instead of the Hall element, and detects the passage of the magnet 18 and outputs a detection signal. This is different from the liquid level detection device according to the first embodiment in that a detection sensor is provided.

The liquid level detection unit 100 includes, for example, a storage switch M ₁ connected to the flip-flop F ₁ instead of the Hall element H ₁ as the detection sensor.

The memory switch M ₁ detects the passage of the magnet 18 that moves along the row of Hall elements, and outputs a detection signal to the flip-flop. As shown in FIG. 2, the memory switch M1 is disposed on the printed circuit board 12 of the liquid level detector 10 (memory switch 15).

For example, when the memory switch M ₁ detects the passage of the magnet 18 moving from the lower stage side to the upper stage side and outputs the detection signal “0”, the memory switch M ₁ detects the passage of the magnet 18 moving from the upper stage side to the lower stage side. Until then, the detection signal “0” is continuously output. On the other hand, when the magnet moving from the upper stage side to the lower stage side passes, the detection signal “1” is output. Thereby, it can be detected by the memory switch M ₁ whether or not the magnet 18 attached to the float 17 has moved out of the lower limit range where the Hall elements H _{1 to} H _n can be magnetically detected.

The memory switch M ₁ detects the passage of the magnet moving from the lower stage side to the upper stage side, outputs the detection signal “1”, detects the passage of the magnet moving from the upper stage side to the lower stage side, and detects the detection signal. “0” may be output.

As the memory switch M ₁ that operates as described above, for example, a reed switch can be cited (NA Corporation website, http://www.na-web.co.jp/products/rs/pr-01 _- 16 _- see the html, search March 2006). This reed switch opens and closes in response to magnetism, and outputs a “0” signal when opened and a “1” signal when closed.

As described above, according to the liquid level detection device of the second embodiment, the hall 18 can detect that the magnet 18 attached to the float 17 has moved out of the lower limit range where the hall element can be magnetically detected. and to a storage switch M ₁ to be connected to the flip-flop F ₁ in place of the element H _1. Thereby, it is not necessary to provide the stand pipe 11 with means for preventing the magnet 18 from moving outside the lower limit range of the magnetic detection.

The liquid level detection unit 100 of the liquid level detection device according to the second embodiment can detect that the magnet 18 attached to the float 17 has moved out of the upper limit range where the Hall element can be magnetically detected. A storage switch M ₂ connected to the flip-flop F _m−1 may be provided instead of the Hall element H _n . For example, when the memory switch M ₂ detects the passage of the magnet 18 moving from the lower stage side to the upper stage side and outputs the detection signal “0”, the memory switch M ₂ detects the passage of the magnet 18 moving from the upper stage side to the lower stage side. Until then, the detection signal “0” is continuously output. When the magnet 18 moving from the upper stage side to the lower stage side passes, the detection signal “1” is output. Thereby, it can be detected by the memory switch M ₂ that the magnet 18 attached to the float 17 has moved out of the upper limit range in which the Hall elements H _{1 to} H _n can be magnetically detected. Therefore, it is not necessary to provide the stand pipe 11 with means for preventing the magnet 18 from moving outside the upper limit range of the magnetic detection.

Further, in order to detect that the magnet 18 attached to the float 17 has moved out of the upper and lower limits where the Hall element can be magnetically detected, a memory switch M ₁ is provided in the flip-flop F ₁ instead of the Hall element H _1. The storage switch M ₂ may be connected to the flip-flop F _m−1 instead of the Hall element H _n .

  In the second embodiment, a magnetoelectric conversion element (Hall element) is used as the liquid level sensing unit, and an element that outputs a signal in response to a magnet is used as the memory switch. Is not limited to this. For example, the liquid level sensing unit may be an element that senses light or ultrasonic waves and outputs a sensing signal. In this case, a member that generates light or ultrasonic waves is attached to the float 17 as the member to be sensed, and an element that detects passage of the member that generates light or ultrasonic waves is used as the memory switch.

  INDUSTRIAL APPLICABILITY The present invention is useful, for example, as a device for detecting a liquid level or a water level in a tank and detecting a water level such as a dam, a reservoir, a river or the like and displaying the liquid level or the water level.

It is a figure which shows the example of 1 structure of the liquid level detection apparatus which concerns on Embodiment 1 of this invention. It is a figure which shows the example of 1 structure of the liquid level detector to which the liquid level detection apparatus which concerns on Embodiment 1 of this invention is applied. It is a figure which shows the example of 1 structure of the liquid level detection apparatus which concerns on Embodiment 1 of this invention. It is a figure which shows one structural example of the flip-flop of the liquid level detection apparatus which concerns on Embodiment 1 of this invention. It is a figure which shows the example of 1 structure of the liquid level detection apparatus which concerns on Embodiment 2 of this invention. It is a block diagram of the conventional liquid level detection apparatus. It is a figure for demonstrating operation | movement of the conventional liquid level detection apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Liquid level detector 11 Stand pipe 12 Printed circuit board 13 Flange 14 Flange 15 Memory switch 16 Mounting band 17 Float 18 Magnet 100, 700 Liquid level detection part 101,701 Control part 102,702 Display part 103 Data processing part 703 Controller 704 Oscillator 705 counter H _{1 to} H _n Hall elements F _{0 to} F _m flip-flops L _{1 to} L _{11 I} / O line T ₁ data signal input terminal T ₂ reset signal output terminal T ₃ pulse signal output terminal

Claims (5)

In the liquid level detection device that detects the position of the liquid level,
A plurality of liquid level detection units arranged on a straight line, each detecting a moving body that moves with a change in position of the liquid level and outputting a detection signal;
A plurality of first flip-flops arranged in a straight line corresponding to each of the plurality of liquid level sensing units, and preset by a sensing signal from the corresponding liquid level sensing unit, and the first flip-flop predetermined And a shift register in which one or more second flip-flops are inserted and arranged every number and preset by a data delimiter signal, and the preset first and second flip-flops A liquid level detector for serially outputting the output from the shift register;
A data processing unit that outputs a detection output of the liquid level position from a serial output output from the shift register;
A liquid level detection device characterized by that. In the liquid level detection apparatus according to claim 1,
The liquid level sensing unit connected to the first flip-flop arranged at one end of the first flip-flop row detects the passage of the moving body that has moved from one direction of the first flip-flop row. The detection signal is continuously output, and when the passage of the moving body that has moved from the direction opposite to the direction is detected, the detection signal is turned off.
A liquid level detection device characterized by that. In the liquid level detection apparatus according to claim 1,
The moving body is a magnet;
The liquid level sensing unit is a magnetoelectric conversion element that outputs a sensing signal in response to a magnet that moves as the liquid level changes.
A liquid level detection device characterized by that. In the liquid level detection apparatus according to claim 3,
The magnetic force of the magnet and the sensitivity of each of the magnetoelectric conversion elements are determined based on the distance between the magnet and each of the plurality of magnetoelectric conversion elements and the spacing between adjacent ones of the plurality of magnetoelectric conversion elements. When positioned between the elements at both ends of the row of magnetoelectric transducers, one or more of the magnetoelectric transducers are selected to output a sensing signal under the action of the magnet.
A liquid level detection device characterized by that. In the liquid level detection apparatus according to claim 3,
The magnetoelectric conversion element is a Hall element.
A liquid level detection device characterized by that.

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