JP4104633B2 - Liquid level detector - Google Patents

Description

  The present invention generally relates to a liquid level detection device, and more particularly to a liquid level detection device using a displacer.

  Conventionally, a liquid level gauge is described as this type of liquid level detection device, for example, in Japanese Patent Laid-Open No. 7-294316 (Patent Document 1). This level gauge has a spring with its upper end locked, a displacer that is suspended from the lower end of the spring, part or all of which is in the liquid to be measured, a magnet that is linked to the movement of the displacer, and the direction of movement And a plurality of magnetic detectors juxtaposed adjacent to each other.

Moreover, a liquid level gauge is described as this type of liquid level detection device, for example, in JP-A-2002-350217 (Patent Document 2). In this level gauge, a displacer is housed inside an outer cylinder with an opening or orifice at the lower end, and an iron core is attached to the upper part via a support bar and spring, and the displacer moves up and down as the liquid level changes. It is configured to be possible. The iron core is disposed in a seal pipe provided at the upper part of the outer cylinder, and moves up and down in the seal pipe in conjunction with the vertical movement of the displacer. On the outside of the seal pipe, a pair of magnets sensitive to the iron core are arranged at intervals in the vertical direction. A micro switch is installed corresponding to each magnet.
JP 7-294316 A JP 2002-350217 A

  In the conventional liquid level gauge described in Japanese Patent Application Laid-Open No. 7-294316 (Patent Document 1), when the range in which the liquid level changes increases, it is necessary to increase the length of the displacer in accordance with the range. In other words, when the length of the tank is increased, the length of the displacer corresponding to the length of the tank is required. However, since there are restrictions on the building or the like that accommodates the tank, there is a problem that if the length of the tank becomes long or the range in which the liquid level changes becomes large, a long displacer corresponding thereto cannot be attached.

  In order to solve the above problem, it is necessary to take measures such as dividing and integrating the displacer or winding up a rod-like body that suspends the displacer. If such measures are taken, there is a problem that the configuration of the apparatus becomes complicated.

  Further, in the liquid level gauge described in Japanese Patent Laid-Open No. 2002-350217 (Patent Document 2), when the range in which the liquid level changes increases, the length of the outer cylinder that stores the displacer is increased according to the range. There is a need. In other words, when the length of the tank is increased, the length of the outer cylinder corresponding to the length of the tank is required. However, since there are restrictions on the building or the like that accommodates the tank, there is a problem that when the length of the tank becomes long or the range in which the liquid level changes becomes large, a long outer cylinder corresponding to that cannot be attached.

  Furthermore, in the above-described conventional liquid level gauge, when the range in which the liquid level changes increases, it is necessary to change the length and size of the liquid level gauge accordingly. For this reason, since it is necessary to design by changing the size of the tank of the liquid to be measured or the size of the liquid level meter according to the range in which the liquid level of the liquid to be measured changes, it is necessary for manufacturing. There is a problem that time becomes long.

  Accordingly, an object of the present invention is to provide a liquid level that can easily change the configuration of the apparatus according to the range without changing the size of the apparatus according to the range in which the liquid level of the liquid to be measured changes. It is to provide a detection device.

A liquid level detection device according to the present invention includes a plurality of displacers that move according to a change in the liquid level of a liquid to be measured, a flexible linear body that is connected to the displacer to suspend and support the displacer, and is connected to one end of a line-shaped body, and the magnetic force generating member interlocked with the movement of the displacer being arranged to stretch in accordance with the movement of the magnetic force generating member, and a spring member located in one end is fixed, the magnetic force It is heavier than a plurality of displacers connected to a plurality of magnetic detectors arranged along the moving direction of the generating member and to the other end opposite to one end of the linear body on the side to which the magnetic generating member is connected. A weight body . A plurality of displacer is suspended at an interval in the vertical direction via the linear body. The gravity and buoyancy generated by the plurality of displacers and the weight body and the restoring force of the spring member are arranged and used in accordance with the change in the liquid level of the liquid to be measured.

In the liquid level detecting apparatus of the present invention, since a plurality of displacer is suspended at an interval in the vertical direction via the linear body, the number of displacer according to the range of varying liquid level of the liquid to be measured Or increase the interval. In addition, spring members having different spring constants may be used according to the range in which the liquid level of the liquid to be measured changes. By changing the configuration of the displacer and spring member in this way, the liquid level that changes within the range without changing the size of the device even if the range in which the liquid level of the liquid to be measured changes increases. Therefore, the configuration of the apparatus can be easily changed.

  The liquid level detection device of the present invention further includes a cylindrical holding member that holds the magnetic force generating member therein, the magnetic force generating member is fixed to the inner peripheral surface of the holding member, and the spring member is attached to the outer peripheral surface of the holding member. Is preferably arranged.

  Thus, the structure of the apparatus can be made compact by integrating the magnetic force generating member, the holding member, and the spring member.

  In this case, it is preferable that the holding member has a flange portion, and the upper end of the spring member is in contact with the flange portion.

  Furthermore, the liquid level detection device according to the present invention includes a cylindrical sealing member disposed so as to cover the magnetic force generation member, the holding member, and the spring member, and the magnetic detection unit is disposed outside the sealing member. Is preferred.

  With this configuration, even if the liquid pressure is applied to the sealing member, the liquid pressure is not applied to the magnetic detection unit. For this reason, what is necessary is just to make the sealing member which coat | covers a magnetic force generation member, a holding member, and a spring member into a pressure | voltage resistant structure, and it is not necessary to make the electric equipment and electronic component which comprise a magnetic detection part etc. into a pressure | voltage resistant structure.

  As described above, according to the present invention, even if the range in which the liquid level of the liquid to be measured changes increases, the liquid level changing within the range can be detected without changing the size of the apparatus. In addition, the configuration of the apparatus can be easily changed.

  FIG. 1 is a schematic cross-sectional view showing a schematic configuration of a main part of a liquid level detection device according to one embodiment of the present invention.

  As shown in FIG. 1, the liquid level detection device 1 includes a movable member 10, a sealing member 20, magnetic detection units 31 to 3n, connection units 40, displacers 51 to 5n, a weight body 60, and a rod-shaped body. 70. Here, n is an integer of 2 or more.

  The movable member 10 includes a cylindrical holding member 11, a spring member 12 held on the outer peripheral surface of the holding member 11, and a magnetic force generation member 13 held inside the holding member 11. The holding member 11 has a flange portion 11a. One end of the spring member 12, that is, the upper end 12 a is in contact with the lower end surface of the flange portion 11 a of the holding member 11, and the other end of the spring member 12, that is, the lower end 12 b is in contact with the upper end surface of the spring pressing member 23. More specifically, the spring member 12 is composed of, for example, a compression coil spring, and is compressed by being sandwiched between the lower end surface of the flange portion 11a of the holding member 11 and the upper end surface of the spring pressing member 23. Is held by. Since the spring pressing member 23 is fixed to the flange portion 22 of the sealing member 20, the lower end 12 b of the spring member 12 serves as a base point for expansion and contraction of the spring member 12. Further, the magnetic force generating member 13, for example, a columnar permanent magnet is fixed to the inner peripheral surface of the holding member 11. In this way, the spring member 12 is arranged so as to expand and contract in accordance with the movement of the magnetic force generating member 13, and the position of the lower end 12b is fixed as the position of one end. It is preferable that the magnetic force generating member 13 is disposed in a substantially central portion in the length direction of the spring member 12, that is, in a range where the spring member 12 is not easily deteriorated. Preferably, a male screw portion is formed on the outer peripheral surface of the spring pressing member 23, a female screw portion is formed on the inner peripheral surface of the flange portion 22 of the sealing member 20, and the male screw portion and the female screw portion are engaged. The spring pressing member 23 may be fixed to the flange portion 22 of the sealing member 20. In this case, the initial compression state of the spring member 12 can be adjusted by adjusting the length of engagement between the male screw portion and the female screw portion. The material of the holding member 11 is preferably a non-magnetic material.

  The sealing member 20 includes a cylindrical portion 21 and a flange portion 22. The cylindrical portion 21 covers the movable member 10 including the holding member 11, the spring member 12, and the magnetic force generating member 13, and the flange portion 22 is in close contact with the top plate portion 101 of the liquid container (tank) 100. The sealing member 20 is disposed.

  The plurality of magnetic detection units 31 to 3n are arranged on the outer side of the cylindrical portion 21 of the sealing member 20 with an interval in the vertical direction. More specifically, each of the magnetic detection units 31 to 3n is arranged in a spiral shape around the outer peripheral surface of the cylindrical portion 21 of the sealing member 20. It is preferable that the magnetic detection units 31 to 3n are arranged in a substantially central portion in the length direction of the spring member 12, that is, in a range where the spring member 12 is not easily deteriorated.

  The rod-like body 70 may be, for example, a linear body such as a flexible wire, and is connected to the displacers 51 to 5n in order to suspend and support the plurality of displacers 51 to 5n. The plurality of displacers 51 to 5n are suspended via the rod-like body 70 at intervals in the vertical direction. Some or all of the plurality of displacers 51 to 5n are in the liquid 200 depending on the position of the liquid level. Each of the plurality of displacers 51 to 5n moves in the vertical direction by buoyancy generated according to the change in the liquid level of the liquid 200 to be measured. The movable member 10 and the plurality of displacers 51 to 5n are connected to each other by the connecting portion 40 via the rod-like body 70. The weight body 60 is heavier than the weight of the displacers 51 to 5n, and is connected to one end of the rod-like body 70 on the side to which the displacers 51 to 5n are connected via the rod-like body 70. The material of the displacers 51 to 5n is preferably resistant to the liquid 200.

  In the liquid level detection device 1 configured as described above, the gravity and buoyancy generated by the plurality of displacers 51 to 5n and the weight body 60 in accordance with the fluctuation of the liquid level of the liquid 200 and the restoring force of the spring member 12 are balanced. To place. At this time, when the displacers 51 to 5n move up and down in accordance with the fluctuation of the liquid level of the liquid 200, the displacers 51 to 5n are moved up and down to balance the gravity and buoyancy generated by the plurality of displacers 51 to 5n and the weight body 60. Until then, the upper end 12a of the spring member 12 is displaced, that is, the holding member 11 and the magnetic force generating member 13 which are integrated in contact with the upper end 12a of the spring member 12 are displaced. Magnetic fluctuations that occur according to the displacement of the magnetic force generation member 13 are detected by the magnetic detection units 31 to 3n.

  In this case, if each of the magnetic detectors 31 to 3n performs a switching operation so as to detect a magnetic fluctuation and correspond to the vertical movement of each of the displacers 51 to 5n, each of the displacers 51 to 5n. Can be detected. For example, as shown in FIG. 1, when the displacer 51 is positioned on the liquid level 201 of the liquid 200, the magnetic detection unit 31 performs a switching operation so as to detect a magnetic variation caused by the magnetic force generation member 13 and turn it on. When the displacer 52 is positioned on the liquid level 202 of the liquid 200, the magnetic detection unit 32 performs a switching operation so as to detect the magnetic variation caused by the magnetic force generation member 13 and turn it on, thereby causing the liquid level 201 and the liquid to be turned on. Variations in the liquid level between the surfaces 202 can be detected.

  In the liquid level detection apparatus 1 according to the present invention, since the plurality of displacers 51 to 5n are suspended at intervals in the vertical direction via the rod-shaped body 70, the liquid level of the liquid 200 is changed as described above. Can be detected. Therefore, the number and interval of the displacers may be increased or decreased according to the range in which the liquid level of the liquid to be measured changes. In addition, spring members having different spring constants may be used according to the range in which the liquid level of the liquid to be measured changes. By changing the configuration of the displacer and the spring member in this way, the size of the apparatus, for example, the size of the displacer, the size of the movable member, even if the range in which the liquid level of the liquid to be measured changes increases. The configuration of the apparatus can be easily changed so that the liquid level changing within the range can be detected without changing the size of the sealing member.

  Moreover, in the liquid level detection apparatus 1 of this invention, since the several displacers 51-5n are suspended at intervals up and down via the rod-shaped body 70, the range in which the liquid level of the liquid to be measured changes In other words, even if the size of the liquid container (tank) 100 becomes large, or there are restrictions on the building that houses the liquid container (tank) 100, the plurality of displacers 51 to 5n are liquidated. It can be easily provided inside the container (tank) 100. As a result, it is not necessary to change the design of the liquid level detector according to the size of the tank that contains the liquid to be measured or the range in which the liquid level of the liquid to be measured changes, thus shortening the manufacturing process can do. In addition, the configuration of the apparatus can be optimized according to the range in which the liquid level of the liquid to be measured changes by arbitrarily changing the mounting positions and intervals of the plurality of displacers by the user.

  Furthermore, the liquid level detection device 1 of the present invention includes a cylindrical holding member 11 that holds the magnetic force generating member 13 therein, and the magnetic force generating member 13 is fixed to the inner peripheral surface of the holding member 11. Since the spring member 12 is disposed on the outer peripheral surface, the configuration of the apparatus can be made compact by integrating the magnetic force generating member 13, the holding member 11, and the spring member 12.

  Furthermore, the liquid level detection device 1 of the present invention includes a cylindrical sealing member 20 disposed so as to cover the magnetic force generation member 13, the holding member 11, and the spring member 12, and the magnetic detection units 31 to 3n are sealed. Since it is arranged outside the member 20, even if the pressure of the liquid 200 is applied to the sealing member 20, no liquid pressure is applied to the magnetic detection units 31 to 3n. For this reason, the sealing member 20 that covers the magnetic force generating member 13, the holding member 11, and the spring member 12 only needs to have a pressure-resistant structure, and the electric devices and electronic components that constitute the magnetic detection units 31 to 3n need to have a pressure-resistant structure. There is no.

  In the above embodiment, since each of the magnetic detection units 31 to 3n is arranged in a spiral around the outer peripheral surface of the cylindrical portion 21 of the sealing member 20, the length of the entire magnetic detection unit in the vertical direction is reduced. The length can be shortened. Thereby, an apparatus can be made more compact.

  The embodiment disclosed above should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above embodiments but by the scope of claims, and includes all modifications and variations within the meaning and scope equivalent to the scope of claims.

It is a schematic sectional drawing which shows the schematic structure of the principal part of the liquid level detection apparatus according to one embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1: Liquid level detection apparatus, 10: Movable member, 11: Holding member, 12: Spring member, 12a: Upper end, 12b: Lower end, 13: Magnetic force generation member, 20: Sealing member, 23: Spring pressing member, 31-3n : Magnetic detection part, 51-5n: Displacer, 60: Weight body, 100: Liquid container (tank), 200: Liquid, 201, 202: Liquid surface.

Claims (4)

A plurality of displacers that move according to fluctuations in the liquid level of the liquid to be measured;
A flexible linear body connected to the displacer to suspend and support the displacer;
Is connected to one end of the line-shaped body, and the magnetic force generating member interlocked with the movement of the displacer,
A spring member that is arranged to expand and contract in accordance with the movement of the magnetic force generating member, and whose one end position is fixed;
A plurality of magnetic detectors arranged along the moving direction of the magnetic force generating member ;
A weight body heavier than a plurality of the displacers connected to one end of the linear body on the side to which the magnetic force generating member is connected and the other end on the opposite side ;
A plurality of said displacer is suspended at an interval in the vertical direction via the linear body,
A liquid level detection apparatus that is arranged and used so that gravity and buoyancy generated by a plurality of the displacer and the weight body and a restoring force of the spring member are balanced according to a change in a liquid level of a liquid to be measured . It further includes a cylindrical holding member that holds the magnetic force generation member inside,
The liquid level detection device according to claim 1, wherein the magnetic force generating member is fixed to an inner peripheral surface of the holding member, and the spring member is disposed on the outer peripheral surface of the holding member. The liquid level detection device according to claim 2 , wherein the holding member has a flange portion, and an upper end of the spring member is in contact with the flange portion. A cylindrical sealing member arranged to cover the magnetic force generating member, the holding member, and the spring member;
The magnetic detection unit is disposed outside of the sealing member, the liquid level detecting apparatus according to claim 2 or claim 3.

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