JP5699400B1 - Liquid level indicator - Google Patents

Abstract

Provided is a liquid level gauge for measuring liquid level with a liquid level of about 5 to 100 m with high accuracy, low cost and stability. A balancer 1 having a liquid level meter 2 for measuring a liquid level distance 8 and transmitting a liquid level distance measurement value, a length measuring cable 9 with a scale for suspending the balancer 1, and a length measuring cable with a scale. With a scale for controlling the length measuring cable length 7 with a scale by determining a liquid level distance reference value for the winding unit 12 and the liquid level meter 2, and using the measured liquid level as a target value. Length measurement cable length control unit 13 and scaled cable length measurement for measuring the length measurement value of the length measurement cable from the length measurement reference point height 10 to the connection point between the length measurement cable 9 and the balancer 1 The measurement reference point height 10 and the measurement liquid level are received by receiving the liquid level distance measurement value measured by the unit 14 and the liquid level measurement meter 2 and adding the liquid level distance measurement value to the length measurement cable length measurement value with a scale. Arithmetic device for calculating the distance between 5 Liquid level meter comprising a 15. [Selection] Figure 1

Description

Detailed Description of the Invention

Industrial application fields

The present invention
(1) Water level measurement with a measuring liquid level of several to 100 m (2) Liquid level measurement where there are obstacles such as dust on the water surface, which cannot be measured by irradiation with radio waves, ultrasonic waves, etc. (3) It can be widely used for measuring the liquid level of industrial tanks other than the water level.
Although the present invention can be used with high accuracy and stability in common for liquid level measurement other than the water level, it will be described as a water level meter in the detailed description of the invention.

Japanese Utility Model Publication No.57-38600 The difference between the contents described in Japanese Utility Model Publication No. 57-38600 and the present invention is as follows.
(1) In Japanese Utility Model Publication No. 57-38600, as a method of detecting the amount of vertical movement of the ultrasonic level detector, the wire rope length is obtained by conversion from the rotation angle of the sheep frictionally coupled to the wire rope. Further, as a modification, there are a method in which an ultrasonic level detector is moved up and down with a rack and a pinion of a drive source and obtained from the number of rotations of the pinion and a method of obtaining from the number of rotations of the torque motor winch shown in the embodiment. However, a method for measuring the length of the length measurement cable by reading the scale of the length measurement cable with the scale of the present invention is not shown.
(2) In Japanese Utility Model Publication No. 57-38600, a long hollow tube is a requirement constituting the invention.
In the present invention, the long hollow tube is not a requirement for constituting the invention.
Further, it is a constituent requirement that the distance from the material surface detected by reflection of the ultrasonic signal by the inner surface of the long hollow tube is kept below a certain value.
In the present invention, the balancer weight portion height, outer diameter, and inner diameter are freely designed, and it is not necessary to keep the measurement distance below a certain value due to the reflection of ultrasonic waves on the inner diameter surface of the balancer. In the present invention, the measurement distance is determined by the characteristics of the ultrasonic distance meter ultrasonic transceiver.
In the present invention, a protective tube may be installed in order to eliminate the influence when there is a wave of liquid level, etc., but the influence of the measurement distance by the protective tube is because the measurement distance of the ultrasonic distance meter ultrasonic transceiver is short. Not.
(3) In claim 2 of the present invention, the measurement signal of the liquid level meter is transmitted by a conductor mounted on a length measuring cable with a scale, and is taken out via a rotating length measuring cable winding portion and a slip ring. . For this reason, the problem of the electric power feeding to the liquid level meter connected via a rotating body and signal extraction is solved. Japanese Utility Model Publication No. 57-38600 does not disclose a method of winding up a signal cable measured with an ultrasonic level detector connected to a computing unit, moving up and down simultaneously with the wire rope.
(4) In Japanese Utility Model Publication No. 57-38600, it is required to have means for lowering the ultrasonic level detector so that the value detected by the ultrasonic level detector is kept below a certain value. In the present invention, the liquid level meter is not lowered so that the distance between the liquid level meter and the measured liquid level is maintained below a certain value, but is maintained at a constant width around the set liquid level distance reference value. Control is performed. For this reason, the operation frequency of the winding motor accompanying the change of the liquid level is reduced, and stable position control is realized.
(5) The present invention does not require that the entire balancer be controlled above the liquid level.
Further, the present invention is not limited to the ultrasonic distance meter as the measurement method of the liquid level meter.

Conventionally, a float method is used as a mechanical method for water level gauges such as rivers, dams, and reservoirs. This method balances with the float that moves up and down as the water level rises and falls, and converts the water level from the rotation angle of the reel that winds the wire attached at the balance point, and the water level measurement accuracy is about ± 1 cm, In order to require a large buoyancy, the diameter of the float becomes large, and in order to secure the distance between the float and the protective tube, a large measuring tube is required as a civil engineering structure. For this reason, dams, large rivers, etc. have not been used much recently.
A pressure-type water level gauge is often used as a contact-type water level meter that measures in contact with the measurement water surface.
This method measures the water pressure proportional to the water depth with a pressure-sensitive element, and requires an air release tube to measure compared to atmospheric pressure, and moisture enters the pressure-sensitive part from this tube, or the pressure-sensitive part. If it is buried in sediments such as rivers, it will cause measurement errors. For this reason, stability is an issue.
As the non-contact water level gauge, an ultrasonic water level gauge and a radio wave level gauge are used.
Since the sensor part does not contact the water surface, these can be measured stably over time.
However, in both the ultrasonic type and the radio type, the radiation angle of the ultrasonic wave or radio wave spreads in proportion to the distance from the sensor, and the measurement distance is limited by an obstacle that unnecessarily reflects the ultrasonic wave or radio wave within the radiation angle.
The radio wave type has a longer measurement distance and better measurement accuracy than the ultrasonic type, and an accuracy of about ± 1 cm can be obtained regardless of the measurement span.
The water level meter of the present invention does not require a large water measuring tube like the float type, there is no problem of deterioration of measurement accuracy over time like the pressure type water level meter, and the water level meter like the ultrasonic type or radio wave type. It is a water level gauge with little restrictions on the measurement water depth without being limited by the measurement distance due to the influence of floating objects and beam expansion.

As a method for measuring depths of 50 m or more, the length measurement of a length measuring cable with a scale is used, and an ultrasonic water level meter for short distance measurement is used as a method for detecting the water level near the water surface. It was solved by using two methods together. Conventionally, as a method of detecting the water surface when the calibrated measuring cable comes in contact with the water surface, electrical continuity when the electrode rod attached to the tip of the calibrated measuring cable is in contact with the water surface is called a stylus type. Although a method for detecting a state has been used, it is easily affected by waves and the like, and since it is difficult to stably detect a conduction state, there are few examples of use recently.
For this reason, as a method for detecting the water surface, a balancer is provided at the end of the length measuring cable with a scale, and the problem of water surface detection is solved by measuring the distance between the balancer and the water surface accurately.
The balancer in the present invention has the meaning of balancing in the vicinity of the liquid surface, and the relative distance between the balancer and the liquid surface in the vicinity of the liquid surface is measured with a short span liquid level meter mounted on the balancer. The vertical position of the balancer is controlled by the length measuring cable position control unit so as to balance within the measurable range of the liquid level gauge. Since the measurable range varies depending on the measurement method of the liquid level gauge, the balance position also varies depending on the measurement method. When the entire balancer is on the water surface, a part may be on the water surface. In any case, the liquid level is detected by measuring the distance between the connecting point between the calibrated measuring cable and the balancer and the measured liquid level with a liquid level gauge mounted on the balancer. Hereinafter, this method is abbreviated as a balancer method.
The height of the measurement reference point and the distance to the connection point between the calibrated measuring cable and the balancer are measured at the calibrated measuring cable length measuring section as the calibrated measuring cable length, and the connecting point between the calibrated measuring cable and the balancer. The short distance between the liquid level and the measured liquid level is measured with a liquid level gauge, and both are added to accurately measure the distance to the water surface.
In the balancer method, the distance between the balancer and the measured liquid surface is measured with a liquid level meter mounted on the balancer. A dead zone is provided in the distance reference value to maintain a constant width. The liquid level distance reference value is set within the measurable range of the liquid level meter in consideration of control stability and minimization of the operation frequency of the balancer take-up motor.
Even in the balancer method, if an ultrasonic liquid level gauge is used as a liquid level measurement sensor, the balancer can measure the liquid level without contacting the measurement water surface, and can be a non-contact method.
As a length measurement cable length measurement method other than the present invention, the length measurement cable winding part is constituted by a drum, the length measurement cable length measurement part is constituted by a rotary encoder connected to the rotation axis of the drum, and the rotation of the encoder The length measurement cable length measurement value using the linear relationship between the angle and the length measurement cable length can be considered, but in order to keep the relationship between the measurement cable winding and the encoder rotation angle accurate, Encoders are expensive. Therefore, in the present invention, a magnetic scale based on the magnetized position of the measuring cable, an RFID scale using the RFID (wireless automatic recognition) chip position as a scale, characters based on OCR (optical character reading), and OMR (optical mark reader). The measuring cable length is measured by a measuring cable with a scale that reads the scale printed with the mark code.
The length measurement cable for this purpose can adopt tape shape and wire shape with a circular cross section, the restrictions on the cable dimensions and winding structure can be relaxed, and the conductor can be mounted on the length measurement cable. The power supply and signal transmission of the meter can be realized.

The effects obtained by solving the problems of the conventional liquid level gauge are as follows.
The water level meter of the present invention is characterized in that the water level is obtained by adding the measured value of the calibrated length measuring cable and the measured value of the liquid level meter mounted on the balancer.
First, in the case of a conventional mechanical float type water level gauge, it is necessary to float the float on the water surface and balance the float and the counterweight with a constant tension by buoyancy.
In this case, the diameter of the float is larger than that of the balancer of the present invention, and in order to install the float in the protective tube, it is necessary to provide a necessary separation distance from the protective tube.
For this reason, a water measuring tube having a diameter of about 600 mmφ is often used for installing a float type water level gauge. In this invention, since the restriction | limiting of the tension | tensile_strength of the length measuring cable with a scale is small, the aperture diameter in the case of installing a protective tube may be about 150 mmphi.
In addition, the installation of protective tubes is not an essential condition for measuring still water without waves.
Secondly, in this method, if a non-contact liquid level gauge such as an ultrasonic type is used as the liquid level gauge mounted on the balancer, it is necessary to submerge the ultrasonic transducer as the sensor unit in water. In addition, since it is not a contact type in which a pressure sensitive part is submerged in water and used like a water pressure type water level gauge, stable measurement can be performed over a long period of time.
Thirdly, in the ultrasonic wave type or radio wave type water level gauge, the distance from the mounting wall surface is determined according to the distance to the measurement water surface due to the spread of the transmission ultrasonic wave and the transmission radio wave beam. In the method, since the balancer does not have to contact the wall surface, the separation distance may be small.
Ultrasonic or radio wave level gauges are affected by reflections from water surface suspended matter, but are not affected by this method.
Fourth, laser level gauges generally require a float for water surface reflection, but this method does not require a float as a liquid level gauge mounted on a balancer.
Fifth, as the measurement accuracy, the liquid level gauge of the present invention can be expected to have an accuracy equivalent to that of the laser type water level gauge or the radio wave type water level gauge, which is the highest precision in the conventional method.
Sixth, calibrated length measuring cables can be calibrated by magnetic scales using magnetized magnetic patterns, scales using RFID, scales using OCR print patterns, scales using OMR print patterns such as bar codes and color codes, and cost. Can be selected.
The liquid level meter mounted on the balancer can be a low-priced and high-accuracy liquid level meter with a measurement span of about several tens of cm to 2 m.
Seventh, the calibrated length measuring cable position control unit can be configured by motor position control, and when the ultrasonic level method is adopted for the liquid level meter, it can also be a non-contact type where the entire balancer does not come in contact with the liquid. is there.

In the present invention, first, the length of the measuring cable with a scale is measured, and secondly, the distance between the measuring cable and the measuring liquid level is measured with a liquid level meter, and the measurement reference point is the sum of both. It is a liquid level gauge that calculates the distance to the liquid level.
[Claim 1] is a balancer type liquid level gauge, and the basic configuration is shown in the selection diagram of FIG.
The length measuring cable length 7 with the scale is obtained as the length of the length measuring reference point 10 and the distance of the connection point 6 between the length measuring cable with the scale and the balancer.
As a representative example of the scale to be applied to the length measuring cable with the scale, the scale is scaled by the following method.
(1) Scale by magnetic scale (2) RFID chip is provided at regular intervals on the measurement cable, RFID chip position is used as the scale, and scale is stored by the scale stored in the RFID chip (3) Measurement cable Scale with printing pattern such as barcode, color code, mark code, numerical value, etc.

The shape of the length-measuring cable 9 with a scale is determined depending on the method and the reading method of the scale, and is a tape shape, a wire shape with a circular cross section, or the like.
The names of length measuring tape, length measuring wire, etc. indicate the shape. In [Claim 2], multi-core metal wiring such as power line and signal line is integrated with length measuring cable 9 with scale. Will be implemented.
For this reason, in the present invention, the name is defined as “measurement cable with scale” by unifying the name of the measurement wire with scale and the measurement tape with scale without distinction.

[Claim 1] of the present invention is a balancer system, and its basic configuration is shown in FIG.
(1) The balancer 1 is connected to a length measuring cable 9 with a scale at a connection point 6 between the length measuring cable and the balancer, and is suspended by the length measuring cable 9 with a scale.
{Circle around (2)} The scaled measuring cable 9 is rolled up or lowered by its own weight through the scaled measuring cable position control unit 13 via the scaled measuring cable winding unit 12 to determine the position of the balancer 1. This position is determined by the liquid level meter 2 by the liquid level distance 8 which is the distance between the connection point 6 between the calibrated length measuring cable and the balancer and the measurement liquid level 5.
In the figure illustrated in FIG. 1, the balancer 1 is entirely above the measurement liquid level 5, but the liquid level distance reference value 52 is determined within the liquid level range in which the liquid level meter 2 can measure the distance, and the measurement liquid level is determined. Control is performed by the calibrated length measuring cable position control unit 13 with the liquid level distance reference value 52 as a target value.
For this reason, a part of the balancer 1 may be lower than the measurement liquid level depending on how the liquid level distance reference value 52 is determined. However, the liquid level distance 8 is not a negative value.
For this reason, the connection point 6 between the calibrated measuring cable and the balancer does not fall below the measurement liquid surface.
In any case, the length measuring cable position control unit 13 with the scale controls the liquid surface distance 8 based on the measured value of the liquid surface distance 8 so that the liquid surface distance 8 falls within a certain range.
In the position control, a liquid surface distance reference value 52 of the liquid surface distance 8 is determined in advance, and when the liquid surface distance 8 is within ± β from this liquid surface distance reference value 52 (referred to as an allowable dead zone), Does not perform control action.
When the liquid level distance 8 deviates from ± β (referred to as outside the allowable dead band), the calibrated length measuring cable position control unit 13 performs a correction operation, and the liquid level distance 8 is within ± α (within the convergence dead band). Control).
Here, α and β are set values, and α <β.
The set values of α and β can be adjusted in order to suppress the operation frequency of the motor of the length measuring cable position control unit 13 with a scale.
An explanatory view of the position control operation is shown in FIG.
(3) In the state where the liquid level distance 8 is within the allowable dead zone, the length of the length measuring cable 9 with the scale is the length 7 of the length measuring cable with the scale, the height 10 of the measuring reference point, the length measuring cable with the scale and the balancer. The distance from the connection point 6 is measured by the length measuring cable length measuring unit 14 with a scale.
(4) The distance between the connection point 6 between the length measuring cable with the scale and the balancer and the measurement liquid level 5 is set as the liquid level distance 8 and is measured by the liquid level measurement unit 4 of the liquid level meter 2 mounted on the balancer 1.
(5) The length measuring cable length 7 with the scale measured above and the liquid level distance 8 are added by the arithmetic unit 15 to obtain a measured value of the liquid level gauge between the length measuring reference point height 10 and the measuring liquid level 5.

[Claim 1] FIG. 3 shows an example of the configuration when the length measuring cable is calibrated with a magnetic scale by the balancer method.
(1) In the configuration example, the graduated length measuring cable winding unit 12 is constituted by a reel or a drum with the rotary shaft 21 as an axis, and the calibrated length measuring cable position control unit 13 is measured by the liquid level meter 2. The distance 8 is received by the signal receiving unit 16, the deviation of the liquid level distance 8 from the liquid level distance reference value 52 is calculated, and the scaled cable measuring position control unit 13 is calibrated to the rotary shaft 21. The position measuring operation of the balancer 1 is performed by rotating the length measuring cable winding unit 12.
When the deviation of the liquid level distance 8 from the liquid level distance reference value 52 is within the permissible dead zone ± β, the position control operation is not performed. When the deviation of the liquid level distance 8 deviates from ± β, the calibrated length measuring cable position control unit 13 performs a correction operation to control the deviation of the liquid level distance 8 within the convergence dead band ± α.
The measuring cable 9 with a scale is a tape-shaped magnetic body and a scale with a measuring pattern of N and S poles is magnetized. The measuring reference point height 10 and the connecting point between the measuring cable with a scale and the balancer 6 can be read by the magnetic sensor of the length measuring cable length measuring unit 14 with a scale.
(2) Configuration Example In FIG. 3, the configuration method of the balancer 1 differs depending on the measurement method of the liquid level measuring unit 4 of the liquid level meter 2. As a system in which the balancer 1 does not come into contact with the liquid surface, FIG. 4 shows that the liquid surface measuring unit 4 is an ultrasonic system and the balancer weight unit 27 is above the liquid surface. The ultrasonic distance meter ultrasonic transmitter / receiver 26 is disposed below the liquid level meter 2. The function of the scaled cable measuring position control unit 13 is that the scaled cable 9 is wound up by the motor 55 while the balancer 1 is lowered by its own weight. The center position of the position control of the measurement liquid level 5 by the length measuring cable position control unit 13 with the scale of the balancer 1 is set to the liquid level distance reference value 52.
The liquid surface distance reference value 52 is set to a value within the ultrasonic distance meter distance measurable range (L5) 33.
When the measured liquid level 5 fluctuates from the liquid level distance reference value 52 due to the fluctuation of the liquid level and deviates from the allowable dead band 54, the position control is performed so that the liquid level distance reference value 52 is set as the target value and enters the convergence dead band 53. If the convergence dead zone 53 is entered once, the position control of the scaled cable 9 is not performed until the tolerance dead zone 54 is removed. The liquid surface distance reference value 52 is set to a value near the center of the ultrasonic rangefinder distance measurable range (L5) 33. The position control does not lower the ultrasonic distance meter ultrasonic transmitter / receiver 26 so that the liquid level distance 8 is kept below a certain value with respect to the measurement liquid level 5, but the stability against the fluctuation of the liquid level, winding up In consideration of minimizing the operation frequency of the motor and the like, the liquid level distance reference value 52 is determined as the target value and control is performed.
In FIG. 4, the balancer 1 suspended by the length measuring cable 9 with the scale is lowered by its own weight. The dead weight is the sum of the weight corresponding to the height (L1) 31 of the liquid level meter and the balancer weight portion 27. Since the tensile tension against the own weight is the winding friction force of the length measuring cable winding part 12 when the weight is lowered, the weight drop can be lowered with a weight corresponding to the height (L1) 31 of the liquid level meter. For this reason, the height of the cylindrical balancer weight portion 27 can be reduced, and design restrictions on the inner diameter of the cylinder are small. For this reason, the influence of the reflection of the ultrasonic beam of the ultrasonic distance meter ultrasonic transmitter / receiver 26 on the cylindrical inner surface of the cylindrical balancer weight portion 27 can be eliminated.
As a configuration method of the balancer 1, FIG. 5 shows a case where the liquid level measuring unit 4 is a guide pulse system. The guide pulse type liquid level gauge transmits a pulse signal from the liquid level measuring unit 4 on the probe 37, receives a pulse signal reflected on the liquid level, and measures a distance from time until transmission 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 is calculated by the equation L = 0.5 × T × C. The probe 37 needs to contact the liquid surface. The balancer weight 27 is cylindrical, and the liquid level reference value 52 is set to a value near the center of the guide pulse type liquid level gauge distance measurable range (L6) 38.
As a method of configuring the balancer 1, FIG. The sensor portion of the liquid level measuring unit 4 serves as an electrostatic sensor electrode 18. In the capacitance method, the balancer weight portion 27 can have a cylindrical shape. The flexible electrostatic sensor electrode 18 is attached to the cylindrical surface of the balancer weight part 27 in the vertical direction, and measures the height immersed in the liquid surface. The liquid level distance reference value 52 is set to a value near the center of the capacitance type liquid level gauge distance measurable range (L7) 39. In any of the ultrasonic method, the guide pulse method, and the electrostatic capacitance method, the liquid surface distance 8 is defined as the distance between the connection point 6 of the length measuring cable with the scale shown in FIG. It can be obtained by the meter 2.

[Claim 1] When an RFID chip is provided on a length measurement cable by a balancer system at a regular interval and the RFID chip position is calibrated with the scale of the RFID chip position, reading by the length measurement cable length measuring unit 14 with the scale is performed by an RFID reader. Except for reading, it is the same as in the case of the measuring cable 9 with a scale by a magnetic scale. Therefore, the diagram of the configuration example is FIG. 3 which is the same as the magnetic scale.
{Circle around (1)} The RFID chip is a passive RFID that receives power from the reader wirelessly, returns a scale signal stored in the chip as a response signal, and the reader receives the length measurement signal. The measuring cable 9 with a scale has RFID chips arranged on a tape-shaped insulator at regular intervals, each RFID chip stores a scale signal, and is connected to the measuring reference point 10, the measuring cable with a scale, and a balancer. The distance from the point 6 can be read by the RFID reader of the length measuring cable length measuring unit 14 with a scale.
(2) The configuration method of the balancer 1 is the same as that of the magnetic scale method, and the liquid level meter 2 can employ any of an ultrasonic method, a guide pulse method, and a capacitance method.

[Claim 1] FIG. 7 shows an example of the configuration in the case where the length measuring cable 9 with a scale is scaled by a code, a numerical value or the like by the balancer method.
The scale is scaled by one line (single track) or a plurality of lines (multiple tracks) in the measurement direction of the length of the measuring cable.
Scaling is performed by the following method.
Barcode optical mark reading (OMR)
Optical character reading (OCR)
3 primary color codes.
In either method, the interval at which the reading scale is added to the length measuring cable 9 with the scale is larger than the magnetic scale.
In the magnetic scale, when the tape width is about 10 mm, the reading interval of the table can be calibrated at intervals of 1 mm in the length measuring direction.
On the other hand, when printing OCR, OMR, code, etc., the printing interval and reading accuracy are taken into account, the scale is calibrated at intervals of 1 cm or more, and the printing on the measuring cable is considered at intervals of 10 cm or more. Grading is considered desirable.
On the other hand, a resolution of about 1 mm is expected for the reading of the measuring cable.
For this reason, the scale is set at an interval of 10 cm or more, and the scale is determined by interpolation.
For this purpose, as shown in FIGS. 7 and 8, the length measuring cable length measuring unit 14 with a scale is constituted by a CCTV camera device, and one scale is marked at the scale reading height 22, and the scale during this time is photographed. Interpolate from the image.
As an example, a scale reading height 22 by a CCTV camera is set to 100 mm or more, and scales are added to the length measuring cable 9 with a scale at intervals of 100 mm. The field of view in the height direction of the camera is set to 100 mm or more, and the field of view of the camera is configured to include at least one scale taken at a measurement reference point height of 10 and an interval of 100 mm. As a result, the distance between the length measurement reference point height 10 and the scale at intervals of 100 mm is obtained by interpolation (referred to as a length measurement reference point distance interpolation method) on the camera screen. FIG. 8 is a diagram for explaining an interpolation method. The uppermost part of the vertical axis of the monitor screen of the calibrated length measuring cable length measuring unit 14 constituted by the CCTV camera device has a length measuring reference point height 10 and the lowermost part is connected to the graduated length measuring cable 9 100 mm below the uppermost part. Set to the corresponding position.
When the vertical axis of the monitor screen is set to 100 scales, the vertical scale of the length measuring cable 9 with the scale corresponds to 1 mm per scale.
The scaled measuring cable 9 is provided with one scale in units of 100 mm. In FIG. 8, the scale height 23 is 10 mm, and the lowermost part of the scale height 23 indicates the scale display position 40 and the display scale value, for example, the scale of the measuring cable of 50,000 mm. In the example of this position, it is at a position 24 mm below the height measurement reference point height 10. Therefore, the length-measured cable length 7 with the scale at the length measurement reference point height 10 is 50,024 mm obtained by adding 24 mm to 50,000 mm (50 m).
This complementary function is performed by the image processing unit of the CCTV camera device.
(1) In the configuration example shown in FIG. 7, the length measuring cable winding portion 12 with a scale is constituted by a reel or a drum with the rotary shaft 21 as an axis, and the length measuring cable position control portion 13 with a scale is formed by a liquid level meter 2. The measured liquid level distance 8 is received by the signal receiving unit 16, the deviation of the liquid level distance 8 from the liquid level distance reference value 52 is measured, and the scaled length measuring cable position control unit 13 determines the measured length with the scale. The position of the balancer 1 is controlled by rotating the rotary shaft 21 of the cable winding unit 12.
(2) [Claim 1] The configuration method of the balancer 1 is the same as that of the magnetic scale method, and the liquid level meter 2 can employ any of an ultrasonic method, a guide pulse method, and a capacitance method.

[Claim 2] In the balancer system of [Claim 1], the power signal transmission to the liquid level measuring meter 2 and the liquid level distance 8 measured by the liquid level measuring meter 2 are used as the arithmetic unit 17 and the position control motor drive circuit 56. The transmission apparatus which transmits to is provided.
The power supply of the liquid level meter 2 is generally possible with a battery. However, in a water level meter that continuously measures the water level outdoors, it is necessary to replace the battery by lifting the balancer 1 from the water surface. In order to remove, the power supply of the liquid level meter 2 is performed by the length measuring cable 9 with a scale. Further, the liquid level distance 8 measured by the liquid level measuring meter 2 is also measured by the length measuring cable 9 with a scale similarly to the power supply.
FIG. 9 shows an example of a configuration diagram of a power signal and liquid level signal transmission device using a length measuring cable 9 with a scale.
The measuring cable 9 with a scale is composed of a magnetized tape, a tape with an RFID chip attached thereto, a bar code, a color code, a tape on which characters, etc. are printed. A plurality of conductive tapes and wires are integrally mounted on these tapes to form a cable. This integrated measuring cable 9 with a scale is defined as “a measuring cable 44 with a scale on which a conductor is mounted”.
The conductor of the calibrated length measuring cable 44 on which the conductor is mounted is electrically connected to the liquid level meter 2, the conductor, and the liquid level meter connecting line 50. The length measuring cable 44 with the conductor mounted thereon is wound by a reel or a drum on the side of the length measuring cable winding portion 12, and the length measuring cable winding portion 12 with the scale at the length measuring cable fixing portion 43 with the scale. It is fixed to. The scaled length measuring cable fixing portion 43 rotates together with the rotating shaft 21. In order to convert the rotating conductor signal line fixed to the length measuring cable fixing portion 43 with the scale into a non-rotating conductor signal line, the conductor signal is rotated by the rotation of the slip ring 45 by the conductor and the slip ring rotating body connection line 51. Input to the body 46 and output from the stationary body 47. Power supply to the liquid level meter 2 is performed by the power signal supply line 48 of the stationary body 47 of the slip ring 45, and the liquid level distance signal measured by the liquid level meter 2 is the liquid level distance output of the stationary body 47 of the slip ring 45. The signal is output as a signal line 49 and connected to the arithmetic device 16 and the position control motor drive circuit 56.
In some cases, the power supply to the liquid level meter 2 and the liquid level distance signal measured by the liquid level meter 2 are multiplexed and transmitted on a common two-wire conductor. The surface distance output signal line 49 performs input / output with two common lines.
The slip ring performs signal conversion between the rotating body 46 and the stationary body 47 by a mechanical contact, but is a signal conversion between the rotating body 46 and the stationary body 47 by a name such as a rotary link connector. Since there are products that perform electromagnetic induction or optical coupling, these products, including these products, are defined as slip rings in this specification.

In the balancer type liquid level gauge of [Claim 1], the measurement liquid level 5 is not a static liquid level but flows in a river or the like and fluctuates due to waves. Further, the balancer 1 and the length measuring cable 9 with scale are subjected to wind pressure load. The liquid level fluctuates due to these effects.
In addition, dust and the like collide with the balancer 1 and affect the liquid level measurement value. For this reason, in many cases, as shown in FIG. 10, the protective cable 19 is provided around the length measuring cable 9 with the scale and the balancer 1. The protective tube 19 is provided with a measurement liquid inlet / outlet hole 20.
Note that the protective tube is not an essential condition of the constituent elements of the present invention. If the influence of waves, wind pressure load, etc. is small and the liquid level fluctuation can be ignored, the protective tube is not necessary.

[Claim 1] Basic configuration diagram corresponding to the balancer system [Claim 1] An explanatory view of a position control operation for maintaining the liquid level distance of the balancer corresponding to the balancer system at the liquid level distance reference value. [Claim 1] A configuration example in which a magnetic scale tape is used for a length measuring cable with a scale corresponding to the balancer system. [Claim 1] Configuration example of an ultrasonic balancer compatible with the balancer method [Claim 1] Configuration example of a balancer of a guide pulse system corresponding to a balancer system [Claim 1] A configuration example of a capacitance type balancer corresponding to the balancer type [Claim 1] A configuration example in which a measuring cable with a scale corresponding to a balancer system is scaled with a cord, a numerical value, etc. [Claim 1] Explanatory drawing of distance measurement reference point distance interpolation method for reading codes, numerical values, etc. of scaled cable with scale corresponding to balancer system [Claim 2] Configuration example of an apparatus for supplying power and delivering a liquid level distance to a liquid level meter Protection tube configuration example

Claims (2)

A balancer equipped with a liquid level meter that measures the liquid level distance between the connecting point of the calibrated measuring cable and the balancer and the measured liquid level and transmits the measured liquid level distance,
A measuring cable with a scale for suspending the balancer;
A measuring cable winding part with a scale,
A scaled length measuring cable position control unit for controlling the length of the length measuring cable with a scale by determining a liquid level distance reference value for the liquid level measuring meter and using the liquid level distance reference value as a target value. When,
A measuring cable length measuring unit with a daily scale that measures the measured length of the measuring cable length with a scale from the height of the measuring reference point to the connection point between the measuring cable with the scale and the balancer,
Receiving the liquid level distance measurement value measured by the liquid level meter, and adding the liquid level distance measurement value to the length measuring cable length measurement value with the scale, the distance between the measurement reference point height and the measurement liquid level An arithmetic unit for obtaining
A liquid level gauge comprising: In claim 1,
A slip ring connected to the rotary shaft of the measuring cable winding portion with the scale;
Electric power is transmitted to the liquid level meter, and a conductor mounted on the graduated measuring cable that transmits the liquid level measurement value;
A conductor for connecting the conductor to the liquid level meter and a liquid level meter connecting line;
A conductor connecting the conductor to the rotating body side of the slip ring and a slip ring rotating body connection line;
A power signal feed line and a liquid surface distance output signal line connected to the stationary body side of the slip ring;
Comprising
The liquid level gauge transmits power to the liquid level gauge and transmits a liquid level distance measurement value from the liquid level gauge.

Images