Float and liquid level meter having float

Abstract

To provide a float capable of suitably reducing an error of liquid level to be detected, and a liquid level meter having the float.SOLUTION: A float of a liquid level gauge which floats on liquid and moves up and down according to liquid level includes: a hollow housing 110 having buoyancy; a magnet unit 160 which is provided in the housing 110 and has magnetic force; and a displacement unit 170 which displaces a vertical position of the magnet unit 160 with respect to the housing 110 according to temperature change of the liquid.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to the technology of a float and a liquid level gauge having a float. [Background technology]

[0002] Conventionally, the technology of a float and a liquid level gauge having a float has been publicly known, as described in Patent Document 1, for example.

[0003] Patent Document 1 describes a magnet-embedded float level gauge (magnetic float level gauge) that detects the level of a liquid by utilizing the magnetic force of a float. The float displaces vertically following the rise and fall of the liquid level. Then, multiple magnetized rotors in a non-magnetic case receive the magnetic force of the float displacing vertically and rotate sequentially. In this way, the level gauge can display (detect) the level of the liquid by the color-coding of the magnetized rotors in the non-magnetic case.

[0004] In the level gauge, the specific gravity of the liquid may change due to a change in the temperature of the liquid. When the specific gravity of the liquid changes in this way, the length of the submerged part of the float changes, which may cause an error in the liquid level displayed by the level gauge.

[0005] In contrast, the technology described in Patent Document 1 makes the magnet piece attached to the float small and lightweight, thereby making the entire float short and lightweight. This makes it possible to reduce the variation in the length of the submerged part of the float in response to changes in the specific gravity of the liquid, and therefore reduces the error in the liquid level displayed by the level gauge.

[0006] However, in the technology described in Patent Document 1, for example, when it is assumed that the specific gravity of the fluid will change to a small value and the float will no longer be able to float, it is necessary to lengthen the float to ensure buoyancy. When the float length is lengthened in this way, the error displayed on the level gauge will increase as the specific gravity of the fluid decreases. Also, for example, when it is necessary to ensure the strength of the float, making the float housing thicker will increase the weight. As a result, the float length is lengthened to ensure buoyancy, and the error displayed on the level gauge will increase as the thickness of the float housing increases. Thus, the technology described in Patent Document 1 is insufficient to reduce the error of the detected liquid level. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2006-250790 A Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention has been made in consideration of the above-mentioned circumstances, and the problem to be solved by this invention is to provide a float and a liquid level gauge having a float that can effectively reduce errors in the detected liquid level. [Means for solving the problem]

[0009] The problem to be solved by the present invention has been described above, and the means for solving this problem will now be described.

[0010] That is, in claim 1, the float of a liquid level gauge floats on liquid and moves up and down according to the liquid level, and comprises a hollow buoyant housing, a magnet portion provided in the housing and having magnetic force, and a displacement portion that displaces the up and down position of the magnet portion relative to the housing in response to temperature changes in the liquid.

[0011] In claim 2, the displacement portion sets the vertical position of the magnet portion to a first position when the temperature of the liquid is relatively low, and sets the vertical position of the magnet portion to a second position higher than the first position when the temperature of the liquid is relatively high.

[0012] In claim 3, the displacement portion includes a bimetal plate that is deformable so as to curve and increase its vertical width based on temperature change when the relatively high temperature is greater than the relatively low temperature, and the magnet portion is placed on the bimetal plate while being supported so as to be freely movable up and down relative to the housing.

[0013] In a fourth aspect of the present invention, the displacement portion includes a base portion that is less deformed due to temperature changes than the bimetal plate at the relatively high temperature, and the bimetal plate is cantilevered on the base portion.

[0014] In claim 5, the bimetal plates are cantilevered on the base portion so that a plurality of the bimetal plates do not vertically overlap one another.

[0015] In claim 6, the displacement portion has an adjustment portion capable of adjusting the first position and the second position.

[0016] In claim 7, the invention has the float according to any one of claims 1 to 6. Effect of the Invention

[0017] The present invention has the following advantages.

[0018] In the present invention, the error in the detected liquid level can be suitably reduced. [Brief description of the drawings]

[0019] [Figure 1] 1A is a schematic side view showing the configuration of a liquid level gauge equipped with a float according to a first embodiment of the present invention, and FIG. [Diagram 2] FIG. 4 is an enlarged schematic vertical cross-sectional view of the float and a portion thereof. [Diagram 3] Also, a partially exploded view of the float. [Figure 4] (a) is a diagram for explaining the configuration of the displacement portion before deformation, (b) is a diagram for explaining the configuration of the displacement portion after deformation, (c) is a schematic vertical cross-sectional view showing the float after the displacement portion has been deformed. [Diagram 5] (a) A schematic diagram showing a conventional float that floats on liquid at high temperatures, (b) A schematic diagram showing a conventional float that floats on liquid at low temperatures, (c) A schematic diagram showing the float of this embodiment that floats on liquid at high temperatures, and (d) A schematic diagram showing the float of this embodiment that floats on liquid at low temperatures. [Figure 6] FIG. 4 is a schematic vertical cross-sectional view of a float according to a second embodiment of the present invention. [Figure 7] Also, a partially exploded view of the float. [Figure 8] (a) A schematic diagram showing a state after deformation of the displacement part, (b) a schematic diagram showing a state before deformation of the displacement part after adjustment by the adjustment part, and (c) a schematic diagram showing a state after deformation of the displacement part after adjustment by the adjustment part. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] In the following description, the up-down direction, the left-right direction, and the front-rear direction are defined according to the arrows shown in the drawings.

[0021] First, the configuration of a liquid level gauge 1 equipped with a float 100 according to a first embodiment of the present invention will be described below with reference to FIG.

[0022] The liquid level gauge 1 is a magnetic float type liquid level gauge that detects the liquid level by utilizing the magnetic force of a float 100 described below. The liquid level gauge 1 can be used in various tanks (containers) that store liquids whose levels need to be detected, such as tanks used in oil plants and chemical plants, water tanks, and boiler tanks (drums). Various liquids such as heat transfer oil, refrigerants, hydrochloric acid, and sulfuric acid can be used as the liquid to be detected.

[0023] In this embodiment, the liquid level gauge 1 is used in a boiler tank (hereinafter referred to as "tank T"). The tank T is assumed to be in operation and stopped. In the following explanation, the liquid temperature is assumed to be high when the tank is in operation and normal temperature (low temperature) when the tank is stopped. The liquid level gauge 1 comprises a chamber 10, an indicator 20, and a float 100.

[0024] The chamber 10 accommodates a float 100, which will be described later. The chamber 10 is mainly made of a non-magnetic material such as a stainless steel pipe. The chamber 10 includes a vertical pipe 11, a closing portion 12, and a flange portion 13.

[0025] The vertical pipe 11 is formed in a generally cylindrical shape extending in the up-down direction. The blocking portion 12 blocks the upper and lower openings of the vertical pipe 11. The blocking portion 12 is provided detachably with respect to the vertical pipe 11, and is removed, for example, when storing a float 100 described later. The flange portion 13 is formed in a generally cylindrical shape that is connected to the vertical pipe 11, and protrudes from the vertical pipe 11 to the side (toward the tank T). In this way, the chamber 10 (and thus the liquid level gauge 1) is attached to the tank T via the flange portion 13. The vertical pipe 11 and the tank T are also connected via the flange portion 13, and the liquid in the tank T flows into the vertical pipe 11 (chamber 10).

[0026] The indicator 20 detects (indicates) the liquid level detected by the liquid level gauge 1. The indicator 20 is mainly made of a non-magnetic material such as a stainless steel pipe. The indicator 20 includes an indicator case 21 and a rotor 22.

[0027] The indicator case 21 is formed in a hollow, generally rectangular parallelepiped shape extending in the vertical direction. The indicator case 21 is provided adjacent to the vertical tube 11 of the chamber 10 and fixed to the vertical tube 11. Thus, the indicator case 21 is erected parallel to the vertical tube 11. An opening 23 is provided on the front side of the indicator case 21. The opening 23 communicates between the inside and outside of the indicator case 21 and is provided so as to extend from the top to the bottom of the indicator case 21. A glass plate or the like is provided in the opening 23.

[0028] The rotor 22 is rotatably supported inside the indicator case 21 at a position facing the opening 23 in the front-rear direction. The rotor 22 is configured to be rotatable by receiving a magnetic force from a float 100 described later. The rotor 22 is colored in a plurality of colors, one color facing the opening 23 during rotation and another color facing the opening 23 during non-rotation. A plurality of rotors 22 are provided to correspond to the openings 23 and extend across the top and bottom of the indicator case 21.

[0029] The float 100 is configured to be capable of floating on the liquid in the chamber 10. Specifically, the float 100 is configured to move in a floating state in accordance with the rise and fall of the liquid level in the chamber 10, and to be able to change its up-down position. In this way, the float 100 is configured to float on the liquid and be able to move up and down according to the liquid level. The float 100 is configured to have a magnetic force by providing a magnet section 160, which will be described later, inside the float 100. The configuration of the float 100 will be described in detail later.

[0030] In the liquid level gauge 1 configured as described above, liquid from the tank T flows into the vertical pipe 11 of the chamber 10 through the lower flange portion 13. In the chamber 10, a float 100 floating in the liquid moves up and down according to the liquid level. Then, the multiple rotors 22 of the indicator 20 rotate sequentially by receiving the magnetic force of the magnet portion 160 of the float 100 that moves up and down. In this way, the liquid level gauge 1 can display (detect) the liquid level of the liquid stored in the tank T by visually confirming the change in color of the multiple rotors 22 through the opening 23 of the indicator 20. In addition, the liquid level gauge 1 can display the detection result on a predetermined display portion provided separately by providing a predetermined control portion, sensor, etc.

[0031] Here, in conventional level gauges, an error may occur in the liquid level displayed by the level gauge depending on the temperature change of the liquid. For example, when the temperature of the liquid changes depending on the operation of the tank T, and the specific gravity of the liquid changes, the length of the submerged portion of the float floating in the liquid changes. For example, Fig. 5(a) shows a float floating in the liquid at high temperature (during operation). Fig. 5(b) shows a float floating in the liquid at room temperature (low temperature) (when stopped).

[0032] As shown in Figures 5(a) and 5(b), if the length of the submerged portion at high temperature (the length from the bottom of the float to the waterline position) is length L1, the length of the submerged portion at normal temperature is length L1-L2, which is shorter than length L1. Therefore, as shown in Figure 5(a), if the position of the magnet part relative to the waterline position is set (fixed) based on high temperature, for example, as shown in Figure 5(a), the position of the magnet part at normal temperature will be located above the waterline position by length L2, as shown in Figure 5(b). Thus, in conventional level gauges, the position of the magnet part relative to the waterline position differs between high temperature and normal temperature, causing errors in the detected liquid level.

[0033] Therefore, the float 100 according to this embodiment is provided with a structure for suppressing the occurrence of the above-mentioned errors.

[0034] The configuration of the float 100 will be described in detail below with reference to FIGS.

[0035] The float 100 includes a housing 110 , a bolt 120 , a lower nut portion 130 , a pipe 140 , an upper nut portion 150 , a magnet portion 160 , and a displacement portion 170 .

[0036] The housing 110 constitutes the outer shell of the float 100. The housing 110 is formed in a hollow, generally cylindrical shape. The housing 110 has buoyancy and can float on liquid. The housing 110 is provided so that its axis faces the up-down direction. The top plate of the housing 110 is provided by, for example, welding so as not to be detachable.

[0037] Bolt 120 is a rod-shaped member with a thread cut on the outer periphery. Bolt 120 is provided so that the longitudinal direction faces the up-down direction. The upper end of bolt 120 is fixed to the top plate of housing 110. Thus, bolt 120 is suspended inside housing 110 so as to extend downward from the top plate.

[0038] The lower nut portion 130 is composed of a pair of nuts 131. The lower nut portion 130 is inserted onto the bolt 120 and is fixed to the vicinity of the lower end of the bolt 120 by the pair of nuts 131 that are fastened to each other.

[0039] The pipe 140 is fitted onto the outside of the bolt 120. The pipe 140 is formed in a cylindrical shape, and the bolt 120 is inserted into the inside of the pipe 140. The outer circumferential surface of the pipe 140 is formed relatively smoothly (compared to the bolt 120, for example). The lower end of the pipe 140 is placed on the lower nut portion 130.

[0040] The upper nut part 150 is composed of a pair of nuts 151. The upper nut part 150 is inserted through the bolt 120 and fixed to the upper part of the bolt 120 by the pair of nuts 151 that are fastened to each other. The lower end of the upper nut part 150 is provided so as to abut against the upper end of the pipe 140. In this way, the upper nut part 150 fixes the pipe 140 between itself and the lower nut part 130 so that the pipe 140 cannot move relative to the bolt 120.

[0041] The magnet section 160 is provided in the housing 110 and has a magnetic force. The magnet section 160 is formed by sandwiching a substantially annular yoke 162 between two substantially annular magnets 161. The two magnets 161 are arranged such that the same poles face each other via the yoke 162. The magnet section 160 has a through-hole 163 that penetrates vertically. The pipe 140 is inserted into the through-hole 163, and the magnet section 160 is supported so as to be movable vertically relative to the pipe 140 (and thus the housing 110). The magnet section 160 is placed on a displacement section 170 (more specifically, a second displacement section 172) described later.

[0042] The displacement portion 170 displaces the vertical position of the magnet portion 160 relative to the housing 110. The displacement portion 170 is configured to deform as a whole based on a change in its own temperature, and its length in the vertical direction changes. In other words, the displacement portion 170 is configured to deform in response to a change in temperature of the liquid around the float 100. The displacement portion 170 includes a first displacement portion 171 and a second displacement portion 172.

[0043] The first displacement portion 171 is a portion that constitutes the lower side of the displacement portion 170. The second displacement portion 172 is a portion that constitutes the upper side of the displacement portion 170. The first displacement portion 171 and the second displacement portion 172 have the same configuration and are provided so as to be stacked vertically. In the following, the configuration of the first displacement portion 171 will be described in detail, and a description of the configuration of the second displacement portion 172 will be omitted as appropriate by assigning the same reference numerals.

[0044] The first displacement portion 171 has a pair of upper and lower bimetal plates and a stainless steel plate 273. Each of the pair of upper and lower bimetal plates is a substantially annular member made of bimetal. In the following description, the lower of the pair of upper and lower bimetal plates may be referred to as the "lower bimetal plate 271," and the upper one may be referred to as the "upper bimetal plate 272."

[0045] The lower bimetal plate 271 has an opening 271a that opens in the vertical direction (see FIG. 4). The pipe 140 is inserted into the opening 271a of the lower bimetal plate 271, and the lower bimetal plate 271 is supported so as to be movable up and down relative to the pipe 140 (and thus the housing 110). The lower bimetal plate 271 is formed by bonding two types of metal plates having different thermal expansion coefficients. Specifically, as shown in FIG. 4(a), a metal plate having a higher thermal expansion coefficient (compared to the upper side) is disposed on the lower side of the lower bimetal plate 271. Also, a metal plate having a lower thermal expansion coefficient (compared to the lower side) is disposed on the upper side of the lower bimetal plate 271. The lower bimetal plate 271 is placed on the lower nut portion 130.

[0046] In this way, the lower bimetal plate 271 has two types of metal plates with different thermal expansion coefficients, and so deforms when it becomes hot. Specifically, as shown in FIG. 4(b), when the lower bimetal plate 271 becomes hot, the metal plate with the higher thermal expansion coefficient expands more than the metal plate with the lower thermal expansion coefficient, so that it bends toward the metal plate with the lower thermal expansion coefficient. Thus, when the lower bimetal plate 271 becomes hot, it deforms by curving in the plate thickness direction so as to become concave and open upward. As a result, when the lower bimetal plate 271 becomes hot, the vertical width becomes larger than before deformation.

[0047] The upper bimetal plate 272 has substantially the same configuration as the lower bimetal plate 271, except that the orientation of the upper and lower parts is different. Specifically, the upper bimetal plate 272 has an opening 272a corresponding to the opening 271a of the lower bimetal plate 271 (see FIG. 4). As shown in FIG. 4(a), a metal plate with a small thermal expansion coefficient is disposed on the lower side of the upper bimetal plate 272. As shown in FIG. 4(b), when the upper bimetal plate 272 becomes hot, it is deformed by curving in the plate thickness direction so as to become a concave shape that is open downward. As a result, when the upper bimetal plate 272 becomes hot, the vertical width becomes larger than before the deformation. The upper bimetal plate 272 is placed on a stainless steel plate 273, which will be described later.

[0048] The stainless steel plate 273 is a substantially annular plate-shaped member made of stainless steel. The stainless steel plate 273 has an opening 273a that opens in the vertical direction (see FIG. 4). The pipe 140 is inserted into the opening 273a of the stainless steel plate 273, and the stainless steel plate 273 is supported so as to be movable up and down relative to the pipe 140 (and thus the housing 110). The stainless steel plate 273 is placed on the lower bimetal plate 271. The amount of deformation of the stainless steel plate 273 due to temperature change is smaller than that of the lower bimetal plate 271 and the upper bimetal plate 272. In this embodiment, the stainless steel plate 273 is assumed to be substantially undeformed even when it becomes hot (specifically, when it becomes hot enough to deform the lower bimetal plate 271 and the upper bimetal plate 272).

[0049] In this way, in the first displacement portion 171, the lower bimetal plate 271, the stainless steel plate 273, and the upper bimetal plate 272 are stacked in order from bottom to top between the lower nut portion 130 and the upper nut portion 150 so as to be vertically movable relative to the housing 110. Although detailed description is omitted, the second displacement portion 172 is placed on the first displacement portion 171. That is, in the second displacement portion 172, the lower bimetal plate 271, the stainless steel plate 273, and the upper bimetal plate 272 are stacked in order from bottom to top between the lower nut portion 130 and the upper nut portion 150 so as to be vertically movable relative to the housing 110.

[0050] Hereinafter, a mode of detection of the liquid level by the float 100 in the liquid level gauge 1 according to this embodiment will be described with reference to FIGS.

[0051] In the following, the temperature of the liquid (high temperature) during operation of the tank T is the temperature at which the lower bimetal plate 271 and the upper bimetal plate 272 deform in the displacement section 170. That is, the temperature (high temperature) of the tank T during operation is set in advance according to its specifications. Therefore, for the lower bimetal plate 271 and the upper bimetal plate 272 of the displacement section 170, metal plates having a thermal expansion coefficient according to the above specifications are adopted, and they are designed to deform when the tank T is in operation (at high temperature).

[0052] In addition, the displacement portion 170 is configured to change the vertical position of the magnet portion 160 relative to the housing 110, since the vertical length of the displacement portion 170 changes (deforms) depending on the temperature of the liquid. Specifically, for example, when the tank T is stopped, the temperature of the liquid is at room temperature (low temperature), so the displacement portion 170 is not deformed. Therefore, as shown in FIG. 2, the magnet portion 160 of the float 100 is provided in a state in which it is placed on the undeformed displacement portion 170 (relatively lower position). Hereinafter, the position of the magnet portion 160 relative to the housing 110 in this state is referred to as the "lower position P1" (see FIG. 2). In this lower position P1, the magnet portion 160 is located immediately above the lower nut portion 130 in the vertical position.

[0053] In contrast, for example, when the tank T is in operation, the temperature of the liquid is high, and therefore the displacement portion 170 is deformed. Therefore, as shown in FIG. 4, the magnet portion 160 of the float 100 is provided in a state in which it is placed on the deformed displacement portion 170 (at a relatively upper position). Hereinafter, the position of the magnet portion 160 relative to the housing 110 in this state will be referred to as the "upper position P2" (see FIG. 4). In this upper position P2, the magnet portion 160 is located above the lower position P1 in the vertical position and immediately below the upper nut portion 150.

[0054] Here, as described above, for example, when the temperature of the liquid changes in response to the operation of the tank T, and the specific gravity of the liquid changes, the length of the submerged portion of the float 100 floating in the liquid (the length from the bottom surface of the float to the waterline position) changes. Therefore, in the float 100 according to this embodiment, the lower position P1 and the upper position P2 are set so as to accommodate the change in the length of the submerged portion based on the specifications of the tank T.

[0055] Specifically, as shown in Fig. 5(c), the upper position P2 is set as the position of the magnet part 160 so as to correspond to the draft position where the submerged portion is long at high temperatures. Also, as shown in Fig. 5(d), the lower position P1 is set as the position of the magnet part 160 so as to correspond to the draft position where the submerged portion is short at room temperature. In this way, even if the length of the submerged portion of the float 100 floating in the liquid changes between high temperatures and room temperatures, the position of the magnet part 160 can be aligned with the draft position, thereby suppressing errors in the detected liquid level.

[0056] The configuration of the float 100 according to the second embodiment will be described below with reference to FIGS.

[0057] In the float 100 according to the second embodiment, the configuration of the displacement portion 300 is significantly different from that of the float 100 according to the first embodiment. In the following description of the float 100 according to the second embodiment, the description of the configuration that is substantially the same as that of the float 100 according to the first embodiment will be omitted as appropriate. The displacement portion 300 of the float 100 according to the second embodiment comprises a first displacement portion 310, a second displacement portion 320, a stainless steel plate 330, and an adjustment portion 340.

[0058] The first displacement portion 310 is a portion that constitutes the lower side of the displacement portion 300. The second displacement portion 320 is a portion that constitutes the upper side of the displacement portion 300. The first displacement portion 310 and the second displacement portion 320 have substantially the same configuration as each other, except that they are provided upside down. Therefore, in the following, the configuration of the first displacement portion 310 will be described in detail, and the description of the configuration of the second displacement portion 320 will be omitted as appropriate by assigning the same reference numerals.

[0059] The first displacement portion 310 has a pair of bimetal plates 311 facing each other in a plan view, and a base plate 312. The pair of bimetal plates 311 are formed so that their vertical positions are the same. The pair of bimetal plates 311 have the same shape except that they are provided in a point-symmetric shape centered on the axis of the pipe 140 in a plan view, so the following description will focus on one bimetal plate 311. In order to simplify the drawings, in Figs. 6 and 8, only one of the pair of bimetal plates 311 is shown in the first displacement portion 310 and the second displacement portion 320.

[0060] The bimetal plate 311 has a different shape from the lower bimetal plate 271 and the upper bimetal plate 272 according to the first embodiment. Specifically, the bimetal plate 311 is formed in a substantially semicircular shape in a plan view. That is, the bimetal plate 311 is formed in a pair to have a substantially circular shape as a whole. The base plate 312 is a member made of stainless steel and has a substantially rectangular shape in a plan view. The bimetal plate 311 is fixed to the base plate 312 by using fixing means (screws 313 and nuts 314) while being in contact with the base plate 312 from above. The fixing means is provided in the vicinity of one end of the bimetal plate 311 in the approximately longitudinal direction. In this way, the bimetal plate 311 is cantilevered relative to the base plate 312.

[0061] The stainless steel plate 330 is configured similarly to the stainless steel plate 273 according to the first embodiment.

[0062] The adjustment unit 340 adjusts the position of the displacement unit 300. The adjustment unit 340 includes a long screw 341 and a pair of nuts 342. The long screw 341 is configured to penetrate the first displacement unit 310 (the base plate 312 and the bimetal plate 311) from below the first displacement unit 310. The pair of nuts 342 are arranged above and below the first displacement unit 310 and are inserted through the long screw 341. The pair of nuts 342 are tightened in a direction approaching each other to fix the long screw 341 to the first displacement unit 310. The long screw 341 is arranged so as to have a predetermined positional relationship with the first displacement unit 310 (specifically, so that the upper end of the long screw 341 protrudes above the first displacement unit 310 by an arbitrary length). The manner of adjustment using the adjustment unit 340 will be described later.

[0063] Thus, in the displacement portion 300 of the float 100 in the second embodiment, from bottom to top, the first displacement portion 310 is placed on the lower nut portion 130, then the stainless steel plate 330 is placed on the adjustment portion 340 fixed to the first displacement portion 310, and then the second displacement portion 320 is placed on the stainless steel plate 330.

[0064] In this configuration, the float 100 of the second embodiment can align the position of the magnet section 160 with respect to the waterline position, as with the float 100 of the first embodiment, thereby suppressing errors in the detected liquid level.

[0065] Specifically, as shown in Fig. 8(a), when the bimetal plate 311 of the first displacement part 310 and the second displacement part 320 becomes hot, the end opposite to one end (the cantilevered side) in the approximately longitudinal direction is deformed so as to move away from the base plate 312. This allows the first displacement part 310 and the second displacement part 320 (and thus the displacement part 300) to have a larger vertical width than before deformation. This allows the position of the magnet part 160 to be aligned with the draft position even if the length of the submerged part of the float 100 floating in the liquid changes between high temperature and normal temperature, so that the occurrence of errors in the detected liquid level can be suppressed (see Fig. 5).

[0066] In addition, in the displacement section 300, a gap is formed between the bimetal plate 311 of the first displacement section 310 and the stainless steel plate 330 by the adjustment section 340 or the head of the screw 313. In addition, a gap is formed between the bimetal plate 311 of the second displacement section 320 and the stainless steel plate 330 by the head of the screw 313. That is, in the displacement section 300, the bimetal plate 311 that deforms in response to temperature changes is provided with a predetermined space (space) on the deforming side. With this, even if the bimetal plate 311 deforms slightly in response to the outside air temperature, for example, when there is a large temperature change between winter and summer, the amount of deformation can be absorbed by the space, so that unintended changes in the lower position P1 and the upper position P2 can be suppressed.

[0067] In the displacement portion 300 according to the second embodiment, the position of the displacement portion 300 can be adjusted by the adjustment portion 340, and therefore the positions of the lower position P1 and the upper position P2 can be adjusted.

[0068] Specifically, for example, when it is desired to make the lower position P1 and the upper position P2 higher than the positions shown in Fig. 6, the long screw 341 is inserted further upward into the first displacement portion 310, and the upper end of the long screw 341 is separated significantly upward from the first displacement portion 310, as shown in Fig. 8(b). In this way, when the displacement portion 300 is in a state before deformation, the position of the magnet portion 160 (lower position P1) can be made higher than the position shown in Fig. 6 by the amount of the long screw 341 protruding. Also, as shown in Fig. 8(c), when the displacement portion 300 is in a state after deformation, the position of the magnet portion 160 (upper position P2) can be made higher than the position shown in Fig. 8(a).

[0069] The adjustment portion 340 can be provided not only on the first displacement portion 310 (or instead of the first displacement portion 310), but also on the stainless steel plate 330 or the second displacement portion 320. With such a configuration, the positions of the lower position P1 and the upper position P2 can be easily adjusted, and further the length between the lower position P1 and the upper position P2 can also be easily adjusted, thereby improving the versatility of the float 100.

[0070] As described above, in the embodiment of the present invention, A float for a level gauge that floats on the liquid and moves up and down according to the liquid level, A hollow housing 110 having buoyancy; A magnet unit 160 having a magnetic force provided in the housing 110; a displacement unit 170 / 300 for displacing the vertical position of the magnet unit 160 relative to the housing 110 in response to a temperature change of the liquid; It is equipped with the following. The present invention also provides a level gauge 1 having the float 100 according to any one of claims 1 to 6.

[0071] With this configuration, the error in the detected liquid level can be effectively reduced.

[0072] In an embodiment, The displacement portions 170, 300 are When the temperature of the liquid is relatively low, the vertical position of the magnet section 160 is set to the lower position P1 (first position), When the temperature of the liquid is relatively high, the vertical position of the magnet section 160 is set to an upper position P2 (second position) which is higher than the lower position P1 (first position).

[0073] With this configuration, the error of the detected liquid level can be suitably reduced. That is, the upper position P2 can be set as the position of the magnet part 160 so as to correspond to the draft position at high temperature. Also, the lower position P1 can be set as the position of the magnet part 160 so as to correspond to the draft position at normal temperature.

[0074] In an embodiment, The displacement portions 170, 300 are The bimetal plate includes a lower bimetal plate, an upper bimetal plate, and a bimetal plate that are deformable so as to bend and increase in width in the vertical direction based on a temperature change when the temperature is relatively high rather than low, The magnet unit 160 is It is placed on the bimetal plate while being supported so as to be movable up and down relative to the housing 110.

[0075] With this configuration, the error in the detected liquid level can be suitably reduced by using a bimetal plate that is relatively resistant to high temperatures.

[0076] In an embodiment, The displacement portion 300 is a base plate 312 that is less deformed due to temperature change than the bimetal plate 311 at the relatively high temperature; The bimetal plate 311 is It is supported by the base plate 312 as a cantilever.

[0077] With this configuration, the amount of deformation of the vertical width of each bimetal plate 311 can be increased, and the length between the lower position P1 (first position) and the upper position P2 (second position) can be increased.

[0078] In an embodiment, The bimetal plate 311 is A plurality of sheets (two sheets) are cantilever-supported on the base plate 312 so as not to overlap each other vertically.

[0079] With this configuration, the member adjacent to the bimetal plate 311 (for example, the stainless steel plate 330) can be pressed at multiple points, so that the stainless steel plate 330 or the bimetal plate 311 can be moved in a stable position.

[0080] In an embodiment, The displacement portion 300 is The lower position P1 (first position) and the upper position P2 (second position) are adjustable.

[0081] With this configuration, the positions of the lower position P1 and the upper position P2 can be easily adjusted, and further the length between the lower position P1 and the upper position P2 can also be adjusted, thereby improving the versatility of the float 100.

[0082] Although one embodiment of the present invention has been described above, the present invention is not limited to the above configuration, and various modifications are possible within the scope of the invention described in the claims.

[0083] For example, in the present embodiment, a bimetal plate is used as the displacement portion, but the present invention is not limited to this. In other words, various members that deform in response to temperature changes, such as a shape memory alloy, can be used as the displacement portion.

[0084] Also, for example, any number of first displacement portions and second displacement portions may be provided in the displacement portions 170 / 300. That is, the displacement portions 170 / 300 may be provided with either the first displacement portion or the second displacement portion, or may be provided with three or more.

[0085] In the float 100 according to the second embodiment, a gap is formed between the bimetal plate of the displacement section and the stainless steel plate by the adjustment section 340 or the head of the screw 313, but this is not limiting. For example, instead of the adjustment section 340 or the head of the screw 313, a gap may be formed by arranging a spacer having an arbitrary configuration.

[0086] Furthermore, the configuration of the adjustment section 340 is not limited to that according to this embodiment, and any configuration can be adopted.

[0087] In addition, although the two bimetal plates 311 are supported in a cantilever manner by one base plate 312, the present invention is not limited to this. In other words, three or more bimetal plates 311 may be supported in a cantilever manner by one base plate 312.

[0088] Furthermore, the liquid level gauge is not limited to the configuration of the liquid level gauge 1 according to this embodiment, and magnet float type liquid level gauges of various configurations can be used. [Explanation of symbols]

[0089] 1 Level gauge 100 Float 110 Cabinet 160 Magnet section 170 Displacement section 300 Displacement section

Claims

1. A float for a liquid level gauge that floats on the liquid and moves up and down according to the liquid level, A hollow housing having buoyancy; A magnet portion provided in the housing and having a magnetic force; a displacement unit that displaces a vertical position of the magnet unit with respect to the housing in response to a temperature change of the liquid; Equipped with Level gauge float.

2. The displacement portion is When the temperature of the liquid is relatively low, the vertical position of the magnet unit is set to a first position, When the temperature of the liquid is relatively high, the vertical position of the magnet unit is set to a second position which is higher than the first position.

2. A level gauge float according to claim 1.

3. The displacement portion is a bimetal plate that is deformable so as to bend and have a larger vertical width based on a temperature change when the relatively high temperature is greater than the relatively low temperature, The magnet portion is The bimetal plate is placed on the bimetal plate while being supported so as to be movable up and down relative to the housing.

3. A level gauge float according to claim 2.

4. The displacement portion is a base portion that is less deformed due to a temperature change than the bimetal plate at the relatively high temperature; The bimetal plate is The base portion is cantilevered.

4. A level gauge float according to claim 3.

5. The bimetal plate is The multiple sheets are cantilever-supported on the base portion so as not to overlap each other vertically.

5. A level gauge float according to claim 4.

6. The displacement portion is an adjustment unit capable of adjusting the first position and the second position; 3. A level gauge float according to claim 2.

7. A liquid level gauge comprising the float according to any one of claims 1 to 6.

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