WO2015194484A1

WO2015194484A1 - Liquid level gauge and transmission device used in liquid level gauge

Info

Publication number: WO2015194484A1
Application number: PCT/JP2015/067068
Authority: WO
Inventors: 哲北澤
Original assignee: 有限会社北沢技術事務所
Priority date: 2014-06-17
Filing date: 2015-06-12
Publication date: 2015-12-23

Abstract

A liquid level gauge is provided with a displacer (1) or a balancer (18). The displacer (1) or balancer (18) is attached to the leading end of a length measurement cable (9) subjected to tension. All or a portion of the displacer (1) or balancer (18) is positioned above a liquid level. The position of the liquid level is measured through the addition of a measured value of the length-measurement-cable length (second distance) (7) from a measurement reference point height (10) to the displacer (1) or balancer (18) and a measured value measured by a liquid level meter (2) positioned near the liquid level of the distance (first distance) (8) from the displacer (1) or balancer (18) to a liquid level to be measured (5).

Description

Liquid level gauge and transmission device used for liquid level gauge

The present invention relates to a liquid level gauge and a transmission device used for the liquid level gauge.

As a liquid level gauge, a water level gauge for measuring the water level is exemplified. Conventionally, a float type water level gauge has been generally used as the water level gauge.
Since the float type water level meter requires a large buoyancy, it is necessary to increase the diameter of the float. Moreover, since the float type water level meter requires a large water measuring tube as a civil engineering structure, the construction cost is expensive. For this reason, recently, float type water level meters have not been used much except when used in dams and large rivers.
Recently, a pressure type water level gauge is generally used. A pressure-type water level gauge is a water level gauge that measures water pressure proportional to water depth. In the pressure type water level gauge, since the measurement is performed in a state where the pressure sensor is in contact with the water to be measured, there is a problem that an error increases with time.

As a technique related to the liquid level gauge, Patent Document 1 describes a liquid level gauge using a displacer. The liquid level meter described in Patent Document 1 includes a spring that suspends and holds a displacer, a displacer that is partly or entirely disposed in the liquid to be measured, a magnet that is linked to the movement of the displacer, and a moving direction of the magnet. Based on a plurality of magnetic detectors arranged along, detection circuits connected to each of the magnetic detectors, and output signals from the respective detection circuits, in which section the liquid level of the liquid to be measured is located And a gate circuit for outputting a section display signal representing. Non-Patent Document 1 describes a JIS standard (Japan Industrial Standards) for an automatic level meter for liquid level measurement.

JP 7-294316 A

The object of the present invention is first to provide a water level meter that does not require a large-diameter water measuring tube as in a float type water level meter. Secondly, it provides a water level gauge that does not cause deterioration in measurement accuracy over time, such as a pressure type water level gauge.
In some embodiments, a displacer-based measurement method is employed as a distance measurement method between the measurement reference point height and the vicinity of the measurement liquid surface. In this method, the displacer is attached to the tip of the length measuring cable, and tension is applied to the length measuring cable so that a part of the displacer protrudes from the liquid surface and balances. First, the length of the length measurement cable from the height of the measurement reference point to the displacer is measured. Second, the length from the displacer to the measurement liquid level is measured by a non-contact type liquid level gauge such as an ultrasonic method. The length from the height of the measurement reference point to the measurement liquid surface is obtained by adding the measurement value of the length measurement cable length and the measurement value of the length from the displacer to the measurement liquid surface.
According to some embodiments, an alternative to a float type water level gauge and a pressure type water level gauge is provided.

Configuration diagram schematically showing an example of a displacer system Configuration diagram schematically showing an example of a displacer system using a rotary encoder as a measuring mechanism for measuring cable length Configuration diagram schematically showing an example of a displacer method for reading the calibrated length measurement cable with the length measurement cable length measurement unit The block diagram which shows typically an example of the displacer which used the ultrasonic distance meter for the liquid level measurement part Configuration diagram schematically showing an example of a displacer using a guide pulse type liquid level measuring unit The block diagram which shows an example of the displacer system which transmits the 1st distance measured with the liquid level measurement part to the arithmetic unit with a radio signal Configuration diagram showing an example of a displacer system using a protective tube Configuration diagram showing an example of a liquid level meter that supplies power to the liquid level meter via a length measurement cable and a slip ring and transmits the first distance to the arithmetic unit Configuration diagram schematically showing an example of a balancer type liquid level gauge Configuration diagram schematically showing an example of a transmission device that supplies power to the liquid level meter via a length measurement cable and a slip ring and transmits the first distance to the arithmetic device and the length measurement cable position control unit.

The first to seventh embodiments will be described with reference to the drawings. In the following description of the drawings, the same or similar elements or portions are denoted by the same reference numerals.

The following first to seventh embodiments exemplify devices for embodying the technical idea of the present invention. Therefore, the technical idea of the present invention should not be construed as limiting the specific configuration, the material, shape, structure, arrangement, and the like of each component to the first to seventh embodiments shown below. The technical idea of the present invention can be variously modified within the technical scope specified by the claims.

Displacer means to exclude liquid.
The displacer 1 is suspended by a length measuring cable 9 to which tension is applied.
The position where the displacer 1 is suspended is a position where a part of the displacer 1 protrudes above the liquid level. Tension is applied to the length measuring cable 9 so that a part of the displacer 1 protrudes above the liquid level.
That is, the weight of the displacer 1 is reduced by the liquid volume excluding the liquid according to Archimedes' principle. While maintaining a state in which a part of the displacer 1 protrudes above the liquid level, the distance from the connection point 6 between the length measurement cable and the displacer to the measuring liquid level 5 is measured by the liquid level meter 2 mounted on the displacer 1. To do.
The above method is abbreviated as a displacer method.
In the displacer method, the long distance from the measurement reference point height 10 to the connection point 6 between the length measurement cable and the displacer is obtained by measuring the length of the length measurement cable 9 and the connection between the length measurement cable and the displacer. A short distance between the point 6 and the measurement liquid level 5 is obtained by measurement with the liquid level meter 2. Then, the position of the liquid surface is accurately measured by adding both the long distance and the short distance.
Here, in the displacer system, it is necessary to maintain a state where a part of the displacer 1 is positioned on the liquid surface. Holding in a state where a portion is located on the liquid level can be easily realized by suspending the displacer 1 with a predetermined range of tension.
That is, the displacer 1 may be suspended with a certain range of suspension tension that causes part of the displacer 1 to protrude above the liquid level. For this reason, the tension | tensile_strength provision part 13 is realizable at low cost with elastic bodies, such as a mainspring spring and a spring.
In FIG. 1 which is a block diagram showing an example of a displacer system,
(1) The displacer 1 is connected to the length measuring cable 9 by a connection point 6 between the length measuring cable and the displacer, and is suspended by the length measuring cable 9.
(2) The length measuring cable 9 is applied with tension by the tension applying unit 13 via the length measuring cable winding unit 12. The value of this tension is set to a value that balances the displacer 1 so that a part of the displacer 1 protrudes from the measurement liquid surface 5.
The tension F applied to the measuring cable 9 by the tension applying unit 13 is measured by measuring the volume below the liquid level of the displacer 1 (the volume in which the displacer 1 is immersed in the liquid level) as V and the mass of the displacer 1 as W. If the density of the liquid is γ and the acceleration of gravity is g, the following formula (1) is satisfied.
W × g−V × γ <F <W × g (1)
Therefore, the value of the tension F does not need to be a constant value, and the value of the tension F may vary.
That is, the tension F to be applied for balancing the displacer 1 so that a part of the displacer 1 protrudes from the measurement liquid surface 5 does not have to be a constant tension. When the volume V below the liquid level of the displacer 1 changes, the tension automatically changes, so that the tension can be easily controlled.
(3) The length of the length measuring cable 9 in a state where the displacer 1 is balanced, that is, the length of the length measuring cable (second distance) 7 so that a part of the displacer 1 protrudes from the measurement liquid surface 5. Is the distance between the measurement reference point height 10 and the connection point 6 between the length measurement cable and the displacer. The length measurement cable length (second distance) 7 can be measured by the length measurement cable length measurement unit 14.
(4) The distance between the connection point 6 of the length measurement cable and the displacer and the measurement liquid level 5 is defined as a first distance 8 in this specification, and the first distance 8 is a liquid level measurement mounted on the displacer 1. It is measured by a total of two liquid level measuring units 4. The length measuring cable length 7 described above is defined as the second distance.
(5) The measured cable length (second distance) 7 and the first distance 8 are added by the arithmetic unit 15, and the added value is the distance between the measurement reference point height 10 and the measurement liquid surface 5, That is, it becomes a measured value of the liquid level gauge.
The displacer 1 comes into contact with water (measurement liquid), but the sensor portion for liquid level measurement can be of a non-contact type that does not come into contact with the measurement liquid by using an ultrasonic liquid level gauge or the like. .
An example of the measuring method of the length measuring cable length 7 is shown below.
In the first example, the length measuring cable winding unit 12 is constituted by a drum. The length measuring cable length measuring unit 14 includes a rotary encoder connected to the rotating shaft 21 of the drum. The length measurement cable length 7 is measured by utilizing the linear relationship between the rotation angle indicated by the rotary encoder and the length measurement cable length 7.
In the second example, a scale is given to the length measuring cable 9, and the length 7 is measured by reading the scale at the reference position. An example is given below as a method of grading.
First, as the shape of the length measuring cable 9, a tape shape, a circular cross-sectional shape, or the like is employed.
(A) Method of providing a scale by providing a magnetic scale on the length measuring cable 9 (B) By providing an RFID (Radio Frequency IDentifier) on the length measuring cable 9 (ie, chip position), Method of giving scale ・ Character code that can be read by OCR (Optical Character Recognition) or mark code that can be read by OMR (Optical Mark Reader) is printed on the measuring cable 9 In the second example, the rotating shaft 21 of the length measuring cable winding portion 12 is omitted, and an elastic body is connected to the fixed shaft of the length measuring cable winding portion 12, Spring force It is also possible to adopt a configuration in which the length measuring cable 9 is wound more.
An example of a method for measuring the first distance 8 is shown below.
(A) Measurement using an ultrasonic distance meter (B) Measurement using a TOF (Time Of Flight) method using a guide pulse (C) Measurement using a capacitance electrode

In the embodiment, the liquid level meter 2 requires power supply. In addition, the first distance 8 measured by the liquid level meter 2 needs to be transmitted from the liquid level meter 2 (signal transmitter 3 of the liquid level meter) to the arithmetic device 15 (signal receiver 16 of the arithmetic device). There is.
As a power supply method to the liquid level meter 2, there is a supply method using a secondary battery. Further, transmission of the first distance 8 from the liquid level meter 2 to the computing device 15 can be performed using a radio signal.
However, the power supply by the secondary battery is inconvenient in that the battery needs to be replaced as the battery is discharged.
As for wireless transmission, when the length measuring cable 9 is accommodated inside a metal protective tube, there is a risk of interference with radio wave propagation.
For this reason, some embodiments relate to improvements in a transmission device for supplying power to the liquid level meter 2 and a transmission device that transmits the first distance 8 from the liquid level meter 2 to the computing device 15.
In some embodiments,
(1) The length measuring cable 9 is constituted by a flat tape on which a conductor can be mounted or a cable having a circular cross section.
(2) The length measuring cable 9 and the liquid level meter 2 are connected by a conductor (cable).
(3) The length measurement cable 9 is wound up by a length measurement cable winding portion 12 such as a reel or a drum which is a rotating body. Since the conductor 30 mounted on the length measurement cable is wound around the rotating body, it cannot be directly connected to the power source or the arithmetic unit 15. For this purpose, the conductor 30 mounted on the length measuring cable and the power source or the arithmetic unit 15 are connected to each other through a slip ring.

(First embodiment)
A configuration example of the first embodiment is shown in FIG.
(1) In this configuration example, the length measuring cable winding unit 12 is configured by a drum having the rotation shaft 21 as an axis. The tension applying unit 13 is configured by an elastic body such as a spring, and the tension applying unit 13 applies tension to the length measuring cable 9 via the length measuring cable winding unit 12. The length measurement cable length measurement unit 14 is configured by a rotary encoder with the rotation shaft 21 as an axis, and the rotation angle of the encoder and the measurement value of the length measurement cable length 7 have a linear correspondence relationship.
A unit in which the length measuring cable 9, the length measuring cable winding portion 12, the tension applying portion 13, and the length measuring cable length measuring portion 14 are integrally formed is commercially available from a plurality of companies under the name of “wire scale linear encoder”. Has been. These products can be used in the first embodiment.
(2) The specific example of the configuration of the displacer 1 varies depending on the measurement method by the liquid level measuring unit 4 of the liquid level measuring meter 2. A specific example of the configuration of the displacer 1 will be described in a third embodiment described later.
(3) In the liquid level meter of the first embodiment, the length measuring cable length 7 which is the distance from the measurement reference point height 10 to the connection point 6 between the length measuring cable and the displacer is measured by the rotary encoder. .
A first distance 8, which is a distance from the connection point 6 between the length measurement cable and the displacer and the measurement liquid level 5, is measured by the liquid level meter 2. The liquid level meter calculates the distance to the measurement reference point height 10 and the measurement liquid level 5 by adding the length of the measurement cable 7 and the first distance 8.

(Second Embodiment)
A configuration example of the second embodiment is shown in FIG.
In the second embodiment, a scale is given to the length measuring cable 9, and the length 7 is obtained by reading the scale.
(1) The displacer 1 is connected to the length measuring cable 9 by a connection point 6 between the length measuring cable and the displacer, and is suspended by the length measuring cable 9.
(2) The length measuring cable 9 is applied with tension by the tension applying unit 13 via the length measuring cable winding unit 12. The value of this tension is set to a value that balances the displacer 1 so that a part of the displacer 1 protrudes from the measurement liquid surface 5.
(3) The length of the measurement cable 9 in this balanced state, that is, the measurement cable length 7 is the distance between the measurement reference point height 10 and the connection point 6 between the measurement cable and the displacer. The length measurement cable length 7 can be measured by the length measurement cable length measurement unit 14.
(4) The distance between the connection point 6 between the measuring cable and the displacer and the measurement liquid level 5 is defined as a first distance 8, and the first distance 8 is the liquid of the liquid level meter 2 mounted on the displacer 1. It is measured by the surface measuring unit 4.
(5) The measured length measurement cable length 7 and the first distance 8 are added by the calculation device 15 (more specifically, the calculation unit 17 of the calculation device), and the added value becomes the measurement reference point height 10 And the measured liquid level 5, that is, the measured value of the liquid level meter.

Examples of the scale applied to the measuring cable 9 and the scale reading method are shown in the following (1) to (3).
(1) Scale by magnetic scale A tape-shaped magnetic body is attached to the measuring cable 9, and the tape-shaped magnetic body is magnetized by a scale having N-pole and S-pole patterns. The magnetic sensor of the length measurement cable length measurement unit 14 obtains the distance between the measurement reference point height 10 and the connection point 6 between the length measurement cable and the displacer by reading the magnetized scale. The scale reading by the magnetic sensor can be read with an accuracy of 1 mm or less.
(2) Scale with the position of the RFID chip as a scale RFID chips are provided on the measuring cable 9 at regular intervals. Using the RFID chip position as a scale, the scale (scale data) stored in the RFID chip is read.
The RFID chip may be a passive RFID. Passive RFID receives a wireless power supply from a reader. The passive RFID returns a signal corresponding to the scale stored in the chip as a response signal, and the reader receives the response signal as a length measurement signal.
RFID chips are arranged at regular intervals on a tape-shaped insulator constituting the length measuring cable 9. Each RFID chip stores scale data. The distance between the measurement reference point height 10 and the connection point 6 between the length measurement cable and the displacer is read by an RFID reader constituting the length measurement cable length measurement unit 14. RFID chips can be arranged on a tape-shaped measuring cable at intervals of several mm.
In reading RFID, information of a plurality of adjacent RFID chips may be read. For this reason, a slit that allows radio waves to pass between the RFID chip (length measurement cable) and the reader is provided, and the number of chips that can be read simultaneously is limited to one or two. When the scales of two chips are read at the same time, the average value of both is used as the scale value.
(3) Scale by printing characters readable by OCR or mark codes readable by OMR Characters, codes, etc. are printed on the measuring cable 9. The printing position is read as a scale.
Reading is performed by a code reader, a camera, or the like.
There are the following methods for reading a scale in which characters or mark codes are printed on a tape-shaped measuring cable 9.
(A) Characters or mark codes printed at intervals of 5 mm or more or 10 mm or more in the length measurement direction of the length measurement cable are read as a scale.
In this method, the readable interval is a character or mark code printing interval. Therefore, it is difficult to read an interval of 5 mm or less or 10 mm or less.
(B) Length measurement by interpolation on an image photographed by the camera The scale reading height portion L6 of the length measurement cable 9 is photographed by the camera constituting the length measurement cable length measurement unit 14 shown in FIG. L6 includes at least one readable scale for characters, codes, and the like.
The distance between the position of the character or code on the image and the measurement reference point height 10 on the image is obtained from the captured image. As a result, the length measurement cable length 7 corresponding to the measurement reference point height 10 can be obtained. In this method, it is necessary that at least one print scale such as a character and a code is arranged at the scale reading height portion L6. As an example, if L6 is set to 100 mm, the length measurement cable length 7 can be obtained with an accuracy of 1 mm or less.

(Third embodiment)
The third embodiment is an embodiment relating to a measurement method in which the first distance 8 is measured by the liquid level meter 2 mounted on the displacer 1.
In the center of FIG. 4, a schematic side view of the displacer 1 is shown. 4 corresponds to the top view of the displacer, and the circle described below in FIG. 4 corresponds to the bottom view of the displacer. The example described in FIG. 4 is an example in which the liquid level measurement unit 4 is an ultrasonic measurement unit. The ultrasonic transmitter / receiver 26 of the ultrasonic distance meter is disposed below the liquid level meter 2.
The transmission wave from the ultrasonic transmitter / receiver 26 of the ultrasonic distance meter is reflected by the liquid surface located in the cylinder, and the reflected wave is received by the ultrasonic transmitter / receiver 26. In this way, the distance to the liquid level is measured.
(A) Since part of the displacer 1 protrudes upward from the liquid level and the displacer 1 is balanced, in the example shown in FIG. 4, a cylindrical displacer mass adjusting unit 27 is employed. The displacer mass adjusting unit 27 has an outer diameter 28, an inner diameter 29, and a height L4.
By changing the size of the outer diameter 28, inner diameter 29 and height L4 of the displacer mass adjusting unit 27 or the density of the substance constituting the mass adjusting unit, the position where the displacer 1 is balanced with respect to the liquid surface can be changed. .
(B) Further, the position at which the displacer 1 is balanced with respect to the liquid level can be changed by the tension applied to the length measuring cable 1. The tension applied to the length measuring cable 9 is determined by the winding length of the length measuring cable and the spring coefficient of an elastic body such as a spring and is within a predetermined range.
(C) The upper limit A of the liquid level in this balanced state corresponds to the balance liquid level 34 when the minimum tension is applied to the length measurement cable, and the lower limit B of the liquid level is the maximum tension applied to the length measurement cable. This corresponds to the balance liquid level 36 at the time. The balance liquid level range is represented by L3 in FIG.
(D) The distance measurable range L5 of the ultrasonic distance meter is determined by the performance of the ultrasonic distance meter.
(E) The balance liquid level range L3 and the distance measurable range L5 are set such that the upper limit A and the lower limit B are within the distance measurable range L5 of the ultrasonic rangefinder.
In addition, the code | symbol L1 is known height (liquid level measuring meter height) previously, and code | symbol L2 shows the range (distance measurement impossible distance) which cannot be measured with a distance meter.
The example described in FIG. 5 is an example where the liquid level measuring unit 4 is a guide pulse type measuring unit. The guide pulse type level gauge transmits a pulse signal on or inside the probe 37, receives a pulse signal reflected on the liquid level, and calculates a distance from the time from transmission to reception of the pulse signal. Assuming that the detection distance is L, the time from transmission to reception is T, and the speed of light is C, the detection distance can be obtained by the equation L = (1/2) × T × C. The ultrasonic method is the same as that described above except that the probe 37 needs to contact the measurement liquid. That is, the displacer mass adjustment unit 27 is cylindrical, the distance measurement possible range, the relationship between the tension application range of the length measurement cable and the balance liquid level, and the like are the same as in the ultrasonic method.

(Fourth embodiment)
In the displacer system, the fourth embodiment is an embodiment that adopts a system that transmits a first distance 8 measured by the liquid level meter 2 to the arithmetic device 15 using a radio signal.
FIG. 6 shows a configuration example of radio signal transmission. A radio signal transmitter 24 is provided in the liquid level meter 2, and a radio signal receiver 25 is provided in the arithmetic device 15, and the first distance 8 is transmitted from the radio signal transmitter 24 to the radio signal receiver 25.

(Fifth embodiment)
The fifth embodiment is an embodiment that employs a configuration in which a protective tube 39 is disposed around a liquid level gauge, particularly around the displacer 1. When the liquid level gauge according to the embodiment is used as a liquid level gauge for measuring a water level in a river or the like, the measurement liquid level 5 is not a static liquid level but a liquid level that fluctuates due to flow and waves.
The displacer 1 and the length measuring cable 9 are subjected to wind pressure load. The liquid level height fluctuates due to these effects.
Further, dust or the like may collide with the displacer 1 and affect the measurement value of the first distance 8. For this reason, as shown in FIG. 7, a protective tube 39 is provided around the level gauge. The protective tube 39 is provided with a measurement liquid inlet / outlet hole 40.
In the fifth embodiment, the inner diameter of the protective tube 39 can be about 150 mm. In the embodiment, the inner diameter of the protective tube 39 can be made smaller than in the case of a float type water level meter (in the float type water level meter, the inner diameter of the protective tube needs to be about 600 mm).

(Sixth embodiment)
The sixth embodiment is an embodiment of a transmission device. The sixth embodiment will be described with reference to FIG.
In the displacer method, the sixth embodiment is a liquid level gauge equipped with a transmission device that transmits electric power to the liquid level meter 2 and transmits the first distance 8 measured by the liquid level meter 2 to the arithmetic unit 15. About.
The power supply of the liquid level meter 2 can generally be realized by a battery. However, for example, in a water level meter that continuously measures the water level outdoors, it is necessary to replace the battery by lifting the displacer 1 from the water surface. As an alternative example, in the sixth embodiment, power supply to the liquid level meter 2 is performed by a conductor 30 mounted on a length measurement cable. In addition, although it is possible to transmit the first distance 8 measured by the liquid level meter 2 by radio, in the sixth embodiment, transmission of the first distance 8 is performed in the same manner as the power supply. This is done by the conductor 30 mounted on the length measurement cable.
The conductor is mounted on the length measuring cable 9 by integrally mounting a plurality of conductor tapes or wires. Electric power and a signal corresponding to the first distance 8 are transmitted by the conductor 30 mounted on the measurement cable.
The conductor 30 mounted on the measuring cable is electrically connected to the liquid level meter 2 via the liquid level meter connection line 47. The conductor 30 mounted on the length measurement cable is wound around the length measurement cable winding portion 12 by a reel or a drum, and is fixed to the length measurement cable winding portion 12 at the conductor fixing portion 41 mounted on the length measurement cable. ing.
The conductor fixing portion 41 mounted on the length measuring cable rotates together with the rotating shaft 21. In order to transmit the signal transmitted by the conductor signal line fixed and rotating to the conductor fixing part 41 mounted on the length measuring cable to the conductor signal line not rotating, the conductor fixing part 41 mounted on the length measuring cable. The slip ring rotating body connection line 48 connected to the is connected to the rotating body 43 of the slip ring 42. A signal from the rotating body 43 is received by the stationary body 44. Power supply to the liquid level meter 2 is performed by a power supply line 45 connected to the stationary body 44 of the slip ring 42, and a signal corresponding to the first distance 8 measured by the liquid level meter 2 is supplied from the slip ring 42. The signal is transmitted to the arithmetic device 15 via the first distance output signal line 46 connected to the stationary body 44.
In general, the slip ring 42 transmits signals between the rotating body 43 and the stationary body 44 by mechanical contact. However, since there is a product having a name such as a rotary link connector and performing signal transmission between the rotating body 43 and the stationary body 44 by electromagnetic induction or optical coupling without using a mechanical contact, in this specification, Slip ring 42 is defined to include these products.

(Seventh embodiment)
The seventh embodiment relates to a balancer type liquid level gauge.
(1) Balancer type liquid level gauge The difference between a balancer type liquid level gauge and a displacer type liquid level gauge will be described. FIG. 9 is a configuration diagram schematically showing an example of a balancer type liquid level gauge.
The difference between them is as follows. (A) In the example of the balancer system shown in FIG. 9, a balancer 18 is provided instead of the displacer 1. The configurations of the displacer 1 and the balancer 18 are the same.
(B) The displacer 1 shown in FIG. 1 is balanced by a part of the displacer 1 protruding above the measuring liquid surface 5 by the length measuring cable 9 to which the tension is applied by the tension applying unit 13.
On the other hand, the balancer 18 shown in FIG. 9 is a state in which a part or the whole of the balancer 18 is positioned above the measurement liquid surface 5 by the length measuring cable 9 given tension by the length measuring cable position control unit 20. Is balanced.
(C) In the case of the displacer 1, the tension is applied by an elastic body. On the other hand, in the case of the balancer 18, the tension is applied by the length measuring cable position control unit 20.
(D) In the balancer method, the distance between the connection point 19 between the length measurement cable and the balancer and the measurement liquid level 5 is measured by the liquid level meter 2 mounted on the balancer 18, and the length measurement cable position control unit 20 The winding amount of the length measuring cable 9 is automatically controlled using the motor 22 (see FIG. 10 if necessary) so that the measured distance falls within a certain range. The details are the same as those described in the eighth and ninth paragraphs of Japanese Patent Application No. 2014-138095.
(E) In the balancer method, the distance between the connection point 19 between the length measurement cable and the balancer and the measurement liquid surface 5 is defined as a first distance 8. Further, the length of the length measurement cable 7 which is the distance between the height 10 of the measurement reference point and the connection point 19 between the length measurement cable and the balancer is defined as the second distance. The second distance is measured by the length measurement cable length measurement unit 14. The measured cable length (second distance) 7 and the first distance 8 are added by the arithmetic unit 15, and the added value is the distance between the measurement reference point height 10 and the measurement liquid surface 5, that is, the liquid. It becomes the measurement value of the surface meter.
(2) Transmission equipment used in the balancer system
(A) In the displacer method, the transmission device transmits electric power to the liquid level meter 2 and transmits the first distance 8 measured by the liquid level meter 2 to the arithmetic device 15. On the other hand, in the balancer method, in addition to transmitting the first distance 8 measured by the liquid level meter 2 to the arithmetic unit 15, the first distance 8 is measured for automatic position control of the balancer 18. The data is transmitted to the long cable position control unit 20.
(B) FIG. 10 shows a configuration example of a transmission apparatus that performs power transmission and transmission of the first distance 8 signal in the balancer system. The configuration of the transmission apparatus in the balancer system is the same as that of the transmission apparatus in the displacer system in the sixth embodiment except for the following points.
First, in the balancer system, the stationary body 44 and the length measuring cable position control unit 20 (more specifically, the signal receiving unit 16 of the length measuring cable position control unit 20) are connected to the first distance output signal line 46. The signal is transmitted through the connector. The signal received by the signal receiving unit 16 is transmitted to a motor drive circuit 23 that is a position control circuit that controls the position of the balancer 18. Second, in the balancer system, the connection point between the conductor 30 mounted on the length measuring cable and the balancer 18 is represented by reference numeral 32 (in the displacer system, the conductor 30 mounted on the length measuring cable and the displacer 1 Is represented by reference numeral 31).

In each of the above embodiments, reference numeral 11 represents a fixing portion for fixing and supporting each member or each element.

In some embodiments, a non-contact liquid level gauge such as an ultrasonic type is adopted as a liquid level meter mounted on the displacer or balancer. And it is not necessary to use a sensor part (for example, ultrasonic transceiver) in contact with measurement liquid. For this reason, in the liquid level meter in the embodiment, it is possible to perform stable measurement over a long period of time as compared with the pressure type liquid level meter in which the sensor unit contacts the measurement liquid. For this reason, it can be used for a wide range of applications including the following applications.
(1) Water level measurement where the distance from the measurement reference point height to the measurement water surface is about several to 100 meters. In the embodiment, when the distance from the height of the measurement reference point to the measurement water level is large, measurement can be performed with high accuracy and low cost.
(2) Liquid level measurement for purposes other than water level measurement (measurement of liquid level in industrial tanks, etc.)

The present invention is not limited to the above embodiments, and it is obvious that the embodiments can be appropriately modified or changed within the scope of the technical idea of the present invention. In addition, various techniques used in the embodiments can be applied to other embodiments as long as no technical contradiction occurs.

This application is based on Japanese Patent Application No. 2014-138095 filed on June 17, 2014, and Japanese Patent Application No. 2014-190498 filed on September 2, 2014. Claim the right and incorporate the entire disclosure of the basic application into this application by reference.

1 Displacer, 2 Liquid Level Meter, 3 Signal Transmitter, 4 Liquid Level Measuring Unit, 5 Measuring Liquid Level,
6 Connection point between measuring cable and displacer, 7 Measuring cable length (second distance),
8 First distance, 9 measuring cable, 10 measuring reference point height, 11 fixing part,
12 measuring cable winding part, 13 tension applying part, 14 measuring cable length measuring part,
15 arithmetic units, 16 signal receivers, 17 arithmetic units, 18 balancers,
19 Connection point between measuring cable and balancer, 20 Measuring cable position controller,
21 Rotating shaft, 22 Motor, 23 Position control circuit (Motor drive circuit),
24 wireless signal transmitter, 25 wireless signal receiver, 26 ultrasonic rangefinder ultrasonic transmitter / receiver,
27 Displacer mass adjustment part, 28 Displacer mass adjustment part outer diameter,
29 Displacer mass adjustment part inner diameter, 30 Conductor mounted on the measuring cable 31 Connection point between the measuring cable mounted with the conductor and the displacer,
32 Connection point between measuring cable and balancer mounted with conductor,
34 Measuring cable minimum tension balance liquid surface A,
36 Measuring cable Maximum tension balance liquid surface B,
37 Probe, 39 Protection tube, 40 Measuring solution access hole,
41 Conductor fixing part mounted on the measuring cable, 42 slip ring, 43 rotating body,
44 stationary body, 45 power feed line, 46 first distance output signal line, 47 liquid level meter connection line,
48 Slip ring rotating body connection line, L1 liquid level meter height, L2 distance not measurable distance,
L3 balance liquid level range, L4 displacer mass adjustment unit height,
L5 distance measurable range, L6 scale reading height part

Claims

A displacer equipped with a liquid level meter that measures the first distance between the connecting point of the measuring cable and the displacer and the liquid level and transmits the first distance measurement value;
A measuring cable for suspending the displacer;
A measuring cable winding part;
A tension applying section that applies tension to the length measuring cable so that a part of the displacer protrudes above the liquid level and balances;
A length measuring cable length measuring unit for measuring a second distance that is a length of the length measuring cable from a height of a measurement reference point to the connection point with the length measuring cable of the displacer;
An operation for receiving the first distance measurement value measured by the liquid level meter and adding the first distance measurement value to the measurement value of the second distance to obtain the distance between the measurement reference point height and the liquid level. Equipment,
A liquid level gauge comprising:
The liquid level meter according to claim 1,
A slip ring connected to the rotary shaft of the measuring cable winding portion;
A conductor mounted on the length measuring cable for transmitting power to the liquid level meter and transmitting a signal corresponding to the first distance measurement value;
A liquid level meter connection line for connecting the conductor to the liquid level meter;
A slip ring rotating body connection line connecting the conductor to the rotating body of the slip ring;
A power feed line and a first distance output signal line connected to the stationary body of the slip ring;
A liquid level gauge.
The balancer mounted with a liquid level meter that measures the first distance between the connection point between the measuring cable and the balancer and the liquid level and transmits the first distance measurement value;
The length measuring cable for suspending the balancer;
A measuring cable winding part;
Tension is applied to the measuring cable so that a part or the whole of the balancer is balanced at a position protruding above the liquid level, and the winding position is controlled using the first distance measurement value as a controlled amount. A measuring cable position control unit,
A length measuring wire length measuring unit for measuring a second distance which is a length of a length measuring cable from a height of a measurement reference point to a connection point of the balancer with the length measuring cable;
An operation for receiving the first distance measurement value measured by the liquid level meter and adding the first distance measurement value to the measurement value of the second distance to obtain the distance between the measurement reference point height and the liquid level. Equipment,
A transmission device used in a level gauge comprising:
A slip ring connected to the rotary shaft of the measuring cable winding portion;
A conductor mounted on the length measuring cable for transmitting power to the liquid level meter and transmitting a signal corresponding to the first distance measurement value;
A liquid level meter connection line for connecting the conductor to the liquid level meter;
A slip ring rotating body connection line connecting the conductor to the rotating body of the slip ring;
A power feed line and a first distance output signal line connected to the stationary body of the slip ring;
A transmission apparatus comprising: