JP2017032446A - Liquid level detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid level detector that can prevent water surfaces from freezing in winter without heaters.SOLUTION: In a liquid level detector 1, a thermostat connects oscillation generation means 10 and an external power source to each other when the ambient temperature drops to a specific temperature (T°C), conveys oscillations generated by activation of the oscillation generating means 10 to a water surface (liquid surface) 6 through a float 2, and oscillates the water surface 6 so that the water surface 6 will be prevented from freezing. Further, in the liquid level detector 1, the thermostat terminates the connection between the oscillation generation means 10 and the external power source 12 when the ambient temperature exceeds a specific temperature (T°C+ΔT°C) so that the oscillation generation means 10 won't operate.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a liquid level detection device used as a water tank water level meter or the like of a hydroelectric power plant, and more particularly, to a liquid level detection device having a liquid surface freezing prevention function.

  For example, water tank level gauges in hydroelectric power stations as liquid level detectors are often float-type water level gauges, which are used in a state where they are housed inside a wave breaker and are affected by external factors such as wind. Measures the water level of the water surface in the breakwater that is not done.

  The water tank of a hydroelectric power station where such an aquarium water level gauge is installed will freeze if the water level is small in winter, and the float will stick to ice, making it impossible to measure the water level on the water surface. .

(First conventional example)
In order to solve such problems, liquid is contained in the float, and the float is heated by an electric heater installed in the float to prevent freezing around the float. Such a technique has been developed (see Patent Document 1).
(Second conventional example)
In addition, a technology has been developed to prevent freezing of water around the water level detection float by placing a ring float so as to surround the water level detection float and heating the heater housed inside the ring float. (See Patent Document 2).

Japanese Utility Model Publication No. 54-115972 Japanese Utility Model Publication No. 1-64028

However, in the first conventional example, since the liquid is contained inside the float, the liquid leaks due to the corrosion of the float, and the freezing around the float cannot be prevented in the winter, and the water level can be measured in the winter. There is a risk of disappearing.
In the first and second conventional examples, the heat of the heater accommodated in the float is transmitted to the water through the float, and the water around the float is warmed to prevent freezing of the water surface. The float must be formed of a metal material (for example, an aluminum alloy) having excellent thermal conductivity, and the float material is limited.

  Accordingly, an object of the present invention is to provide a liquid level detection device that can prevent the liquid surface from freezing in winter without using a heater.

  The present invention relates to a liquid level detection apparatus 1 that floats a float 2 on a liquid surface 6 and measures the liquid level by moving the float 2 up and down. The liquid level detection device 1 according to the present invention includes a vibration generating means 10 housed inside the float 2 and a first pulley 8 rotatably attached to a base 9 above the liquid level 6. And an electric wire built-in wire 11 that is wound around the first pulley 8 and suspends the float 2, and an external power source 12 and the vibration generating means 10 that are built in the electric wire built-in wire 11 are connected via a thermostat 13. The electric wire 14 to be connected, the second pulley 15 arranged coaxially with the first pulley 8 and rotating integrally with the first pulley 8, and the balance wound around the second pulley 15 And a balance weight 17 that is attached to the wire 16 and that urges the first and second pulleys 8 and 15 so as to hold the wire 11 with a built-in electric wire in a stretched state. In the liquid level detection device 1 according to the present invention, when the atmospheric temperature or the liquid temperature is lowered to a predetermined temperature (T ° C.), the thermostat 13 connects the vibration generating means 10 and the external power source 12, and the vibration The vibration generated by the operation of the generating means 10 is transmitted to the liquid surface 6 through the float 2, and the liquid surface 6 is vibrated to prevent the liquid surface 6 from freezing. Further, the liquid level detection device 1 according to the present invention is configured so that the thermostat 13 is connected between the vibration generating means 10 and the external power source 12 at a temperature (T ° C. + ΔT ° C.) where the atmospheric temperature or the liquid temperature exceeds the predetermined temperature. The connection is cut off and the vibration generating means 10 is not operated.

  According to the liquid level detection device of the present invention, since the liquid level around the float can be made rippled by the vibration generated by the vibration generating means built in the float, the liquid level in the winter season can be used without using a heater. Freezing can be prevented.

It is a figure which shows the liquid level detection apparatus which concerns on embodiment of this invention, Fig.1 (a) is a whole block diagram of a liquid level detection apparatus, FIG.1 (b) is one of the liquid level detection apparatuses of Fig.1 (a). FIG. 1C is a partial side view (a view of the liquid level detection device of FIG. 1A viewed from the B1 direction), and FIG. 1C is an explanatory view of the structure of the vibration preventing means (a partially enlarged view of FIG. 1A). It is. 2A is an enlarged cross-sectional view of the float, FIG. 2B is an enlarged cross-sectional view taken along the line A1-A1 of FIG. 2A, and FIG. 2C is the float. FIG. 3 is a top view (plan view of the float viewed from the direction B2 in FIG. 2A). It is a figure which simplifies and shows the electric circuit of the liquid level detection apparatus which concerns on embodiment of this invention. It is an expanded sectional view of the float of the liquid level detection apparatus which concerns on the modification of this invention, and is a figure corresponding to Fig.2 (a). It is a figure which simplifies and shows the electric circuit of the liquid level detection apparatus which concerns on the modification of this invention, and is a figure corresponding to FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  1 to 3 are views showing a liquid level detection device 1 according to the present embodiment. 1A is an overall configuration diagram of the liquid level detection device 1, and FIG. 1B is a partial side view of the liquid level detection device 1 in FIG. 1A (the liquid in FIG. 1A). FIG. 1C is a structural explanatory view of the vibration preventing means 29 (a partially enlarged view of FIG. 1A). 2A is an enlarged cross-sectional view of the float 2, and FIG. 2B is an enlarged cross-sectional view taken along the line A1-A1 of FIG. 2A, and FIG. ) Is a top view of the float 2 (a plan view of the float 2 as viewed from the direction B2 in FIG. 2A). Moreover, FIG. 3 is a figure which simplifies and shows the electric circuit 3 of the liquid level detection apparatus 1 which concerns on this embodiment.

  As shown in these drawings, the liquid level detection device 1 floats a float 2 on a water surface (liquid surface) 6 inside a wave breaker tube 5 installed in a water tank 4 of a hydroelectric power plant. The (liquid level) is measured, and the measured value is recorded in the recorder 7. The liquid level detection device 1 includes a first pulley 8 rotatably attached to a recorder 7 on a base 9 to which an upper portion of a wave breaker tube 5 is fixed, and vibration generation accommodated in the float 2. A thermostat that includes a means 10, a flexible wire 11 that is wound around the first pulley 8 and suspends the float 2, and an external power source 12 and a vibration generator 10 that are built in the wire 11. An electric wire (flexible insulated wire) 14 connected via 13 etc., a second pulley 15 arranged coaxially with the first pulley 8 and rotating integrally with the first pulley 8, and a second pulley A balance weight 17 that is attached to a balance wire 16 that is wound around 15 and that urges the first and second pulleys 8 and 15 so as to hold the wire-incorporated wire 11 in a stretched state. Yes. In addition, after the electric wire built-in wire 11 is drawn out from the float power supply box 21, it is drawn into an electric wire guide hole 20 formed at the center of the rotating shaft 18 of the first and second pulleys 8 and 15, and the electric wire guide hole 20. It is pulled out from the inside to the outer peripheral surface of the first pulley 8 and wound around it. The wire guide hole 20 incorporates a wire twist preventer (not shown) that prevents twisting of the wire. Thereby, the wire 11 with a built-in electric wire is not twisted even if the first pulley 8 is rotated. The first pulley 8 may be separated from the recorder 7 and attached to a support frame or the like installed on the base 9 so as to be rotatable.

  The thermostat 13 is located between the external power supply 12 and the float power supply box 21 and measures the atmospheric temperature in the breaker tube 5. That is, the thermostat 13 is turned on when the atmospheric temperature falls to a predetermined temperature (freezing prevention temperature T ° C.) slightly higher than the freezing temperature of the water surface (liquid surface) 6, and the external power source 12 and the AC / DC converter 22 are turned on. Is connected, and the vibration generating means 10 in the float 2 is energized through the polarity converting means 23 to operate the vibration generating means 10. Further, the thermostat 13 is turned off when the atmospheric temperature exceeds the freezing prevention temperature (T ° C. + ΔT ° C.), cuts off the connection between the external power source 12 and the AC / DC converter 22, and passes to the vibration generating means 10. And the vibration generating means 10 is not operated.

  The vibration generating means 10 includes a vibration box 25 fixed to a frame 24 attached in the float 2, a rod-like movable side permanent magnet 27 that is accommodated in the vibration box 25 and moves along a rail 26, and the movable box A pair of fixed-side electromagnets 28 and 28 juxtaposed along the moving direction of the side permanent magnet 27.

  The rail 26 includes an upper guide rail 26a and a lower guide rail 26b made of a synthetic resin material, and a movable permanent magnet 27 is slidably accommodated between the upper and lower guide rails 26a and 26b. The rail 26 guides both upper and lower surfaces of the movable permanent magnet 27 and guides both side surfaces of the movable permanent magnet 27. The rail 26 has stationary blocks 30 and 30 fixed to both ends in the longitudinal direction (both ends in the direction along the X axis in FIG. 2A), and the movable permanent magnet 27 that slides moves to the stationary block 30. , 30. The rail 26 is formed with slits 31a and 31b on both upper and lower surfaces and both side surfaces, and the movable permanent magnet 27 accommodated in the rail 26 is provided outside (internal space of the vibration box 25) via the slits 31a and 31b. ), And the magnetic force of the fixed-side electromagnets 28 and 28 effectively acts on the movable-side permanent magnet 27. The rail 26 is fixed to the inner surface of the vibration box 25 with a screw or an adhesive (not shown).

  When the polarity of the electricity supplied by the polarity conversion means 23 is converted, the fixed-side electromagnets 28 and 28 change the N-pole and S-pole alternately. Reciprocate along the rail 26. The movable permanent magnet 27 that reciprocates along the rail 26 alternately collides with the stationary block 30 on one end side and the stationary block 30 on the other end side of the rail 26, and vibrates due to an impact at the time of collision with the stationary block 30. The box 25 is vibrated. The vibration of the vibration box 25 is transmitted to the float 2 through the frame 24 and is transmitted to the water surface 6 through the float 2, thereby making the water surface 6 ripple. Note that the polarity conversion means 23 includes a polarity conversion switch and a switch control circuit that operates the polarity conversion switch.

  As shown in FIGS. 1 (a) and 1 (c), a vibration preventing means 29 that absorbs and attenuates the vibration of the wire 11 with a built-in electric wire is provided in a portion of the upper portion of the wave preventing tube 5 where there is no possibility of contact with the float 2. Is preferably installed. The vibration preventing means 29 shown in these drawings includes a movable portion 29a that slides in contact with the wire 11 with a built-in electric wire, a fixed portion 29b that supports the movable portion 29a so as to be slidable with respect to the breaker tube 5, have. The movable portion 29a includes a hemispherical contact (or a shape in which a round bar is halved) that contacts the wire 11 with a built-in electric wire, a hook-shaped portion 29a2 formed integrally with the contact 29a1, And a shaft portion 29a3 formed integrally with the flange portion 29a2. The fixing portion 29b includes a damper box 29b1 that accommodates the distal end side of the shaft portion 29a3 so as to be slidable, and a support arm 29b2 that fixes the damper box 29b1 to the wave preventing tube 5. The damper box 29b1 accommodates the bearing portion 29b3 therein, and the shaft portion 29a3 is slidably fitted into the bearing hole 29b4 of the bearing portion 29b3, and is interposed between the bearing hole 29b4 and the shaft portion 29a3. Grease 29c is filled. The shaft portion 29a3 is a slide guide portion 29a31 having a round bar at the tip, and a thread groove portion 29a32 is formed in the vicinity of the slide guide portion 29a31 and in a portion that fits with the bearing portion 29b3. Further, grease 29c is filled between the slide guide portion 29a31 and the thread groove portion 29a32 of the shaft portion 29a3 and the bearing hole 29b4. A coil spring 29d is accommodated between the flange-shaped portion 29a2 of the movable portion 29a and the damper box 29b1. One end of the coil spring 29d in the height direction is in contact with the flange portion 29a2 of the movable portion 29a, and the other end in the height direction is in contact with the end surface of the damper box 29b1.

  Such vibration preventing means 29 contacts the wire-incorporated wire 11 so that the contact 29a1 slightly deforms the wire-incorporated wire 11, and the axial direction of the shaft portion 29a3 (the direction in which the shaft portion 29a3 is pushed into the damper box 29b1). ) Is applied with the tension of the wire 11 with a built-in electric wire. In the vibration preventing means 29, when the float 2 vibrates due to the vibration generated by the vibration generating means 10, and the vibration is transmitted to the electric wire built-in wire 11, the movable portion 29a is slid by the electric wire built-in wire 11. The coil spring 29d is elastically deformed, and the viscous resistance of the grease 29c between the thread groove portion 29a32 and the slide guide portion 29a31 and the bearing hole 29b4 acts on the movable portion 29a. As a result, the vibration preventing means 29 can absorb and dampen the vibration of the float 2 side electric wire built-in wire 11a (11), and the vibration of the float 2 side electric wire built in wire 11a (11) is absorbed by the first pulley 8. It is possible to prevent transmission to the side of the electric wire built-in wire 11b (11), the first pulley 8, and the recorder 7 side. The vibration preventing means 29 is not limited to the vibration preventing means 29 illustrated in FIG. 1A and FIG. 1C, and any means capable of absorbing and attenuating vibration of the wire 11 with a built-in electric wire. It can be applied in place of the vibration preventing means 29 of FIGS. 1 (a) and 1 (c). Further, the vibration preventing means 29 is attached to a frame or the like (not shown) located outside the breaker tube 5 and on the base 9 so as to contact the wire 11 with a built-in wire between the first pulley 8 and the float 2. It may be configured.

  As shown in FIG. 3, the AC / DC converter 22 and the polarity conversion means 23 are accommodated in a float power supply box 21. In the float power supply box 21, a first lamp 32 (light emitting device such as an LED) that is turned on when energized is disposed. As a result, the operator confirms a thermometer (not shown) provided in the float power supply box 21 and the like, and the first temperature is reduced to the predetermined temperature (freezing prevention temperature T ° C.). When the lamp 32 is not lit, the operator can determine the failure of the liquid level detection device 1 by visually checking the first lamp 32. Further, the outer surface 33 of the float 2 that is visible from above (preferably, the outer surface 33 positioned above the water surface 6 (liquid surface)) is lit when the vibration generating means 10 is energized. A second lamp 34 (light emitting device such as an LED) is arranged. As a result, the operator confirms the thermometer (not shown) provided in the float power supply box 21 and the like, and the second temperature is reduced to the predetermined temperature (freezing prevention temperature T ° C.). When the lamp 34 is not lit, the operator can determine the failure of the liquid level detection device 1 by viewing the second lamp 34. Further, when the second lamp 34 is lit, the operator can confirm from above the breaker tube 5 that the vibration generating means 10 in the float 2 is operating normally.

  In the liquid level detection device 1 according to the present embodiment having the above-described structure, when the float 2 is displaced with the displacement of the water surface 6, the distance between the first pulley 8 and the float 2 changes. At this time, the second pulley 15 is constantly urged in the direction of winding the electric wire built-in wire 11 wound around the first pulley 8 by the balance wire 16 and the balance weight 17. As a result, in the liquid level detection device 1, when the float 2 is displaced with the displacement of the water surface 6 and the distance between the float 2 and the first pulley 8 changes, the wire 11 with a built-in wire 11 corresponding to the change in the distance. Is wound around the first pulley 8 and the wire 11 with a built-in electric wire is always kept in a tensioned state. Then, in the liquid level detection device 1, the first pulley 8 is rotated by the change in the length of the wire 11 with a built-in electric wire, and the rotation amount of the first pulley 8 is transferred to the recorder 7 as the displacement amount of the float 2. To be recorded. The recorder 7 is configured to transmit the recorded measurement data to a remote data processing center or the like.

  Further, in the liquid level detection device 1 according to the present embodiment, when the atmospheric temperature falls to a predetermined temperature (freezing prevention temperature T ° C.) slightly higher than the freezing temperature of the water surface 6, the thermostat 13 is turned on, and the external power source 12 And the AC / DC converter 22 are connected via the thermostat 13, the polarity conversion means 23 is activated, and the polarity of the electricity supplied to the stationary electromagnets 28, 28 of the vibration generating means 10 in the float 2 is changed. Converted continuously. As a result, the fixed electromagnets 28 and 28 of the vibration generating means 10 in the float 2 alternately generate N poles and S poles, and the movable permanent magnets 27 change the rails according to changes in the magnetic poles of the fixed electromagnets 28 and 28. The reciprocating movable permanent magnet 27 alternately collides with the stationary blocks 30 and 30 at both ends of the rail 26 to generate vibration. The vibration generated when the movable-side permanent magnet 27 collides with the stationary block 30 is transmitted to the float 2 through the vibration box 25 and the frame 24, and the vibration transmitted to the float 2 is transmitted to the water surface 6 around the float 2. Thus, the water surface 6 can be waved and the water surface 6 can be prevented from freezing.

  Thus, since the liquid level detection apparatus 1 according to the present embodiment can prevent freezing of the water surface 6 without using a heater, the material of the float 2 is not limited to a metal having good thermal conductivity, The float 2 (float body 2a) can be formed of an optimum material according to the type (an optimum material from a wide range of materials including a synthetic resin material).

  Further, in the liquid level detection device 1 according to the present embodiment, the first lamp 32 is installed in the float power supply box 21 and the second lamp 34 is installed in the float 2. When the power supply is interrupted due to inconvenience such as disconnection in the middle of 10, the operator can easily visually recognize the device failure (occurrence of trouble) by the first lamp 32 and the second lamp 34. As a result, the liquid level detection device 1 according to the present embodiment enables the worker to perform repair work at an early stage, and reduces the labor of the operator's inspection work (device inspection work). Further, the liquid level detection device 1 according to the present embodiment enables the operator to visually recognize the operating state of the vibration generating means 10 from the upper part of the wave breaker tube 5 by turning on the second lamp 34 of the float 2. . In contrast to the liquid level detection device 1 according to the present embodiment, the first conventional example cannot confirm from the outside whether or not the electric heater accommodated in the float is energized, and has a freeze prevention function. I could not confirm from the outside whether it worked effectively. Further, in the second conventional example, it is impossible to confirm from the outside whether or not the heater in the ring float is energized, and it is not possible to confirm from the outside whether or not the freeze prevention function is working effectively. Therefore, in the first and second conventional examples, the failure that the electric heater or heater cannot generate heat due to disconnection or the like is left for a long period of time, the freezing around the float in winter cannot be prevented, and the water level measurement in winter is not possible. There is a risk that it will not be possible. On the other hand, the liquid level detection device 1 according to the present embodiment does not cause a problem as in the first and second conventional examples.

  In the liquid level detection device 1 according to the present embodiment, only one of the first lamp 32 and the second lamp 34 is installed, and the other of the first lamp 32 and the second lamp 34 is installed. It may be omitted.

  Further, the liquid level detection device 1 according to the present embodiment floats the float 2 on the water surface 6 inside the wave breaker 5 installed in the water tank 4 of the hydroelectric power plant, and measures the displacement of the water surface 6. However, the present invention is not limited to this, and when measuring the water level of the water surface 6 that does not wave due to external factors such as wind, the breakwater tube 5 may be omitted.

  Moreover, although the liquid level detection apparatus 1 which concerns on this embodiment measures the water level of the water tank 4 of a hydroelectric power station, it is not restricted to this, It is used in order to measure the liquid level of liquids other than water. can do.

  Further, in the liquid level detection device 1 according to the present embodiment, the thermostat 13 is configured to measure the atmospheric temperature in the breaker tube 5, but is not limited thereto, and the thermostat 13 is installed in the float 2. You may comprise so that water temperature (liquid temperature) may be measured with the thermostat 13 in the float 2. FIG.

  Moreover, you may comprise the liquid level detection apparatus 1 which concerns on this embodiment so that the function as an oil leak detector may be exhibited collectively. That is, the liquid level detection device 1 has a plurality of electrodes (not shown) for detecting an oil layer floating on the water surface 6 attached to the float 2, and detects the capacitance of the electrode portion by a high frequency generated from a detection circuit (not shown). Further, it may be detected that oil is floating on the water surface (the presence of oil may be detected using the fact that the capacitance changes greatly when oil flows into the water surface). The liquid level detection device 1 thus configured can reliably detect the water level (liquid level) and can appropriately detect oil leakage.

(Modification)
4 to 5 are diagrams showing modifications of the liquid level detection device 1 according to the embodiment. FIG. 4 is an enlarged cross-sectional view of the float 2 and corresponds to FIG. FIG. 5 is a diagram showing a simplified electrical circuit 3 of the liquid level detection device 1 according to this modification, and corresponds to FIG.

  The liquid level detection device 1 according to the present modification is configured such that the configuration of the vibration generating means 10 housed in the float 2 and the electric circuit 3 that supplies electricity to the vibration generating means 10 is the liquid level detection device according to the above embodiment. 1 is the same as the liquid level detection device 1 according to the above-described embodiment. Therefore, the liquid level detection device 1 according to the present modification will be described as follows, omitting the description overlapping with the description of the liquid level detection device 1 according to the above embodiment.

  In the present modification, the vibration generating means 10 has a vibration box 25 and a vibration motor 35. The vibration motor 35 may be one used for a mobile phone or the like, and may be either a cylindrical type or a button type. For example, a weight is biased to the tip of the shaft, and vibration is caused by an unbalanced weight of the weight. It may occur. The vibration motor 35 is fixed in the vibration box 25 and operates to generate vibration when energized from the external power supply 12 via the thermostat 13 and the AC / DC converter 22. In the liquid level detection device 1 according to this modification, the vibration generated by the vibration motor 35 is transmitted to the float 2 (float body 2a) via the vibration box 25 and the frame 24, and the vibration transmitted to the float 2 is transmitted. The water surface 6 around the float 2 can be waved to prevent the water surface 6 from freezing. The vibration motor 35 stops operating when the thermostat 13 is turned off and the power supply is cut off.

  The liquid level detection device 1 according to this modification as described above can obtain the same effect as that of the liquid level detection device 1 according to the above-described embodiment. Therefore, the polarity conversion means 23 in the above embodiment is not necessary, and the configuration of the electric circuit 3 is simplified.

  In the present modification, the vibration motor 35 is operated by direct current, but is not limited to this, and a motor that operates by alternating current may be used. When the vibration motor 35 that operates with direct current is replaced with one that operates with alternating current, the AC / DC converter 22 becomes unnecessary, and the configuration of the liquid level detection device 1 is simplified.

  DESCRIPTION OF SYMBOLS 1 ... Liquid level detection apparatus, 2 ... Float, 6 ... Water surface (liquid level), 7 ... Recorder, 8 ... First pulley, 9 ... Base, 10 ... Vibration generating means, 11 ... ... Wire with built-in wire, 12 ... External power supply, 13 ... Thermostat, 14 ... Wire, 15 ... Second pulley, 16 ... Balance wire, 17 ... Balance weight

Claims (8)

In a liquid level detector that floats on the liquid surface and measures the liquid level by moving the float up and down,
Vibration generating means housed inside the float;
A first pulley rotatably mounted on a base above the liquid level;
An electric wire built-in wire that is wound around the first pulley and suspends the float;
An electric wire built in the electric wire built-in wire and connecting an external power source and the vibration generating means via a thermostat;
A second pulley disposed coaxially with the first pulley and rotating integrally with the first pulley;
A balance weight attached to a balance wire wound around the second pulley and biasing the first and second pulleys so as to hold the wire built-in wire in a stretched state, and
When the atmospheric temperature or the liquid temperature falls to a predetermined temperature (T ° C.), the thermostat connects the vibration generating means and the external power source, and the vibration generated by the operation of the vibration generating means is performed via the float. Propagate to the liquid level, prevent the liquid level from freezing by vibrating the liquid level,
At a temperature (T ° C. + ΔT ° C.) where the atmospheric temperature or the liquid temperature exceeds the predetermined temperature (T ° C. + ΔT ° C.), the thermostat cuts off the connection between the vibration generating unit and the external power source, and does not operate the vibration generating unit.
A liquid level detection device characterized by that. The vibration generating means is a vibration motor.
The liquid level detection device according to claim 1. An AC / DC converter is disposed between the thermostat and the vibration motor.
The liquid level detection device according to claim 2, wherein: An AC / DC converter is arranged between the thermostat and the vibration generating means, and a polarity converting means is arranged between the AC / DC converter and the vibration generating means, and the electric power supplied to the vibration generating means is The polarity is converted continuously,
The vibration generating means includes
A rod-like movable permanent magnet supported slidably by a frame, and a pair of fixed electromagnets juxtaposed along the sliding direction of the permanent magnet,
A stationary block in which when the polarity of electricity supplied to the pair of fixed-side electromagnets continuously changes, the movable-side permanent magnet reciprocates along the frame, and the movable-side permanent magnet is fixed to the frame. To generate vibration by colliding with
The liquid level detection device according to claim 1. The AC / DC converter is housed in a float power supply box,
In the float power supply box, a lamp that is turned on when energized is arranged,
The liquid level detection device according to claim 3. The AC / DC converter and the polarity conversion means are accommodated in a float power supply box,
In the float power supply box, a lamp that is turned on when energized is arranged,
The liquid level detection device according to claim 4, wherein: On the outer surface of the float and the outer surface visible from above, a lamp that is lit when energizing the vibration generating means is disposed.
The liquid level detection device according to claim 1, wherein the liquid level detection device is a liquid level detection device. The vibration preventing means for absorbing and attenuating the vibration of the electric wire built-in wire is attached at a position not in contact with the float, and is configured to contact the electric wire built-in wire between the first pulley and the float.
The liquid level detection device according to claim 1, wherein the liquid level detection device is a liquid level detection device.

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