Liquid level detection float

Abstract

To prevent a liquid level detection float from climbing up or being buried in sludge, etc., accumulated at a bottom part of a liquid storage tank, and to suppress rolling up of the sludge, etc., and the adhesion of the sludge, etc., to the liquid level detection float when unloading the liquid storage tank.SOLUTION: A liquid level detection float has a cylindrical float part 11 that is mounted on a guide part that extends in a vertical direction and is installed in a liquid storage tank so that it can move up and down, where a bottom surface of the float part 11 is provided with eight bottom side vane parts 12 that extend radially in eight directions at 45 degree intervals from a surface extending directly downward from a wall surface of a through hole 13, have a rectangular or square cross-sectional shape, and have lengths of upper and lower sides of the rectangle or square equal to a thickness of the float part 11.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a liquid level detection float used for measuring the liquid level in a liquid storage tank for storing liquids such as oil.

Background Art

[0002] Conventionally, a liquid level detection float has been used to measure the liquid level in a liquid storage tank. For example, as shown in FIG. 12, a liquid storage tank 1 for storing a liquid such as oil is provided with a liquid injection pipe 2, a liquid discharge pipe 3 connected to a pump P and a flow meter M, and a magnetostrictive liquid level gauge 4 for detecting the liquid level of the stored liquid and the water level of the water accumulated at the bottom of the liquid storage tank 1 and transmitting liquid level data. The magnetostrictive liquid level gauge 4 has a detection unit 5 installed above the liquid storage tank 1, a magnetostrictive wire 6 extending from the detection unit 5 to the bottom of the liquid storage tank 1, an upper liquid level detection float 7 and a lower liquid level detection float 8 that are slidable up and down along a guide unit 10 containing the magnetostrictive wire 6 and contain magnets, and a liquid level data transmission unit 9 for transmitting liquid level data.

[0003] In addition, in the liquid level detection float of such a liquid level gauge, in order to prevent poor conductivity due to scale, rust, etc. generated in the tank, or the movement of the float from being deteriorated due to the adhesion of scale, etc. between the shaft and the float, inventions described in Patent Document 1 (Japanese Utility Model Publication No. 52-10933) and Patent Document 2 (Japanese Patent Publication No. 5-70090) have been proposed. That is, Patent Document 1 describes an invention in which a blade float (7) is coupled to a shaft rod (6) protruding from the lower part of a float (5), and when the blade float (7) rotates due to the water flow flowing through the tank, both the float (5) and the conductive material (8) are rotated, preventing the conductive material (8) and the electrodes (9, 10) from having poor conductivity (see particularly FIG. 2, lines 34-36 in the left column on page 1 and lines 32-38 in the right column on the same page). Patent Document 2 describes an invention in which a large number of blade parts (9) extending in a spiral direction that extends in the circumferential direction of the float (8) and is symmetric with respect to the vertical axis (1a) are extended on the outer peripheral surface of the float (8), and when the blade parts (9) receive the force of the wave and the float (8) rotates around the vertical axis (1a), no dust such as scale stays between the vertical axis (1a) and the float (8), preventing the occurrence of clogging between the vertical axis (1a) and the float (8) (see particularly FIGS. 1 and 2, lines 13 in the left column on page 2 to line 3 in the right column on the same page). However, the invention described in Patent Document 1 is for preventing poor conductivity in the float chamber, and the invention described in Patent Document 2 is for preventing the occurrence of clogging between the vertical axis (1a) and the float (8), and it does not prevent the normal liquid level detection from becoming impossible when the float rides on or is buried in sludge, scale, rust, iron powder, etc. (hereinafter referred to as "sludge, etc.") accumulated at the bottom of the tank.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] The problem to be solved by the present invention is to prevent a liquid level detection float from riding on or being buried in sludge or the like accumulated at the bottom of a liquid storage tank, and to suppress the lifting of sludge or the like and the adhesion of sludge or the like to the liquid level detection float during discharging.

Means for Solving the Problem

[0006] The invention according to claim 1 for solving the above problem is a liquid level detection float having a cylindrical float portion that is movably mounted up and down with respect to a guide portion that extends vertically and is installed in a liquid storage tank, wherein a plurality of bottom-side blade portions that extend radially from the central axis side of the float portion are provided on the bottom surface of the float portion and a plurality of side - wing roots extending radially from the central - axis side of the float part are provided on the side surface of the float part, the bottom - side wing roots and the side - side wing roots are provided continuously and is characterized by this.

[0007] The invention according to claim 2 for solving the above problem is, in the liquid level detection float of the invention according to claim 1, wherein the bottom-side blade portions are characterized in that the distance from the central axis of the float portion is larger on the lower side.

[0008] The invention for solving the above problem according to claim in 3 is please claim in 1 in the liquid level detection float of the invention. wherein the lower part of the bottom-side blade portions is characterized in that it becomes thinner on the lower side.

[0011] The invention for solving the above problem according to claim 4 is, in the liquid level detection float of the invention according to claim 1 wherein the bottom-side blade portions or the side-side blade portions are characterized in that a cross section cut by a plane perpendicular to the central axis of the float portion is arc-shaped.

Effect of the Invention

[0013] ​According to the invention according to claim 1, on the bottom surface of the float portion that is movably attached in the vertical direction with respect to the vertically extending guide portion provided in the liquid storage tank, a plurality of bottom surface side blade portions that radially extend from the central axis side of the float portion are provided. Therefore, before the bottom surface of the float portion approaches the bottom of the liquid storage tank, the bottom surface side blade portions receive the liquid flow generated in the liquid storage tank, and the float portion rotates, so that sludge and the like accumulated at the bottom of the liquid storage tank can be discharged from below the float portion and scattered around the float portion. Therefore, when the bottom surface of the float portion approaches the bottom of the liquid storage tank, only a small amount of sludge and the like exist in the vicinity of the float portion, and it is possible to avoid the liquid level detection float from riding on or being buried in the sludge and the like accumulated at the bottom of the liquid storage tank. Also, during unloading, since the lifting of sludge and the like is unlikely to occur in the vicinity of the float portion, the adhesion of sludge and the like to the liquid level detection float can be suppressed. And, a plurality of side - wing roots extending radially from the central - axis side of the float part are provided on the side surface of the float part. Since the bottom - side wing roots and the side - side wing roots can receive the flow of the liquid generated in the liquid storage tank, the float part can be rotated even if the flow is weak. Furthermore, since the bottom - side wing roots and the side - side wing roots are provided continuously, the float part is easy to be molded.

[0014] According to the invention according to claim 2, in addition to the effect of the invention according to claim 1, since the bottom surface side blade portion has a greater distance from the central axis of the float portion toward the lower side, when the bottom surface side blade portion receives the liquid flow generated in the liquid storage tank and rotates, sludge and the like can be discharged from below the float portion in a wider range and scattered around the float portion.

[0015] Claim in 3 According to the related invention please Claim in 1 In addition to the effect of the related invention, since the lower part of the bottom surface side blade portion becomes thinner toward the lower side, when the lower end of the bottom surface side blade portion hits the sludge and the like accumulated at the bottom of the liquid storage tank, it can deeply sink and efficiently discharge the sludge and the like from below the float portion and scatter them around the float portion.

[0018] Claim 4 According to the invention related to 1In addition to the effects of the invention according to this, since the cross-section of the bottom-side blade roots or the side-side blade roots cut by a plane orthogonal to the central axis of the float portion is arc-shaped, it is possible to efficiently receive the flow of the liquid generated in the liquid storage tank, and even a weaker flow can rotate the float portion.

Brief Description of the Drawings

[0020]

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Modes for Carrying Out the Invention

[0021] The liquid level detection float of the present invention rotates the float part by receiving the liquid flow generated in the liquid storage tank by the bottom side blade parts or the side surface side blade parts before the bottom surface of the float part approaches the bottom of the liquid storage tank, and the liquid flow generated by the rotation and the contact between the lower end part of the bottom side blade part and sludge or the like discharge the sludge or the like accumulated at the bottom of the liquid storage tank from below the float part and act to scatter it around the float part. Therefore, in the case of the magnetostrictive liquid level gauge 4 installed in the liquid storage tank 1 shown in FIG. 12, it is applied to the lower liquid level detection float 8 that can slide up and down along the magnetostrictive wire 6 and detect the water level of the water accumulated at the bottom of the liquid storage tank 1. Hereinafter, embodiments of the present invention will be described by way of examples. The description of the liquid level detection float according to each example is premised on the case of using it as the lower liquid level detection float 8. However, the present invention is applicable not only to magnetostrictive liquid level gauges but also to liquid level gauges having a float part that can move up and down with respect to the guide part.

Example

[0022] FIGS. 1(A) to (E) are a plan view, a front view, a bottom view, a perspective view, and a cross-sectional view taken along line A-A in FIG. 1(A) of the liquid level detection float according to Example 1, respectively. The liquid level detection float according to Example 1 includes a cylindrical float part 11 that is movably mounted up and down on a guide part 10 (see FIG. 12) incorporating a magnetostrictive wire 6, and eight bottom side blade parts 12 that extend radially from the central axis side of the float part 11 on the bottom surface of the float part 11. The float part 11 is set so that the overall specific gravity is smaller than that of water and larger than that of liquids such as oil, and since the through hole 13 provided along the central axis is inserted into the guide part 10, it can freely move up and down according to the water level. Further, as shown in FIGS. 1(C) to (E), the bottom side blade parts 12 extend radially in eight directions at 45-degree intervals from the surface obtained by extending the wall surface of the through hole 13 straight down, and the cross-sectional shape thereof is a rectangle or a square, and the lengths of the upper side and the lower side of the rectangle or the square are equal to the thickness of the float part 11.

[0023] Since the liquid level detection float according to the first embodiment has the above-described configuration, when a liquid such as oil is discharged from the liquid storage tank 1 through the liquid discharge pipe 3 or a liquid such as oil is injected into the liquid storage tank 1 from the liquid injection pipe 2, and a liquid flow occurs in the liquid storage tank 1, the bottom side blade portions 12 receive the flow and the float portion 11 rotates. Then, the sludge or the like accumulated at the bottom of the liquid storage tank 1 is scattered around the float portion 11, so that the sludge or the like can be removed from below the float portion 11. That is, since a state where only a small amount of sludge or the like always exists below the float portion 11 is maintained, when the bottom side blade portions 12 approach the bottom of the liquid storage tank 1, the lower end portions thereof do not ride on or get buried in the sludge or the like, and it is possible to prevent the normal liquid level (the water level when applied to the lower liquid level detection float 8 in FIG. 12) from not being detected.

Embodiment

[0024] FIGS. 2(A) to (E) are a plan view, a front view, a bottom view, a perspective view, and a cross-sectional view taken along line B-B in FIG. 2(A) of the liquid level detection float according to the second embodiment, respectively. The liquid level detection float according to the second embodiment is different from the first embodiment only in that the eight bottom side blade portions 14 provided on the bottom surface of the float portion 11 are shaped to spread more downward. Therefore, the description of the configuration other than the bottom side blade portions 14 is omitted, and the same reference numerals as those in FIG. 1 are used in the description of the second embodiment. As shown in FIGS. 2(C) to (E), the bottom side blade portions 14 of the second embodiment extend radially in eight directions at 45-degree intervals from the surface obtained by extending the wall surface of the through hole 13 straight down, and the distance from the central axis of the float portion 11 is larger on the lower side. Further, the cross-sectional shape thereof is trapezoidal, the length of the upper side of the trapezoid is equal to the thickness of the float portion 11, and the length of the lower side of the trapezoid is longer than the thickness of the float portion 11.

[0025] The liquid level detection float according to Example 2, with the above configuration, has a longer lower side of the bottom side blade part 14. When a liquid flow occurs in the liquid storage tank 1, it is more easily affected by the flow than the bottom side blade part 12 of Example 1. Therefore, the bottom side blade part 14 rotates efficiently and can exclude sludge, etc. from below the float part 11 and scatter it around the float part 11 in a wider range.

Example

[0026] Figs. 3(A) to (E) are respectively a plan view, a front view, a bottom view, a perspective view of the liquid level detection float according to Example 3, and a cross-sectional view taken along the line C-C in Fig. 3(A). The liquid level detection float according to Example 3 is different from Example 1 only in that bottom side blade parts 15 and side side blade parts 16 are provided on the bottom surface and the side surface of the float part 11, respectively. Therefore, the description of the configuration other than the bottom side blade part 15 and the side side blade part 16 is omitted, and the same numbers as in Fig. 1 are used in the description of Example 3. As shown in Figs. 3(C) to (E), the bottom side blade part 15 of Example 3 extends radially in eight directions every 45 degrees from the surface obtained by extending the wall surface of the through hole 13 straight downwards. Its cross-sectional shape is a rectangle or a square, and the lengths of the upper side and the lower side of the rectangle or the square are longer than the thickness of the float part 11. Also, the side side blade part 16 of Example 3 extends radially in eight directions every 45 degrees around the central axis from the side surface of the float part 11. Its cross-sectional shape is a rectangle, and the lengths of the upper side and the lower side of the rectangle are equal to the length obtained by subtracting the thickness of the float part 11 from the length of the bottom side blade part 15. Here, the bottom side blade part 15 and the side side blade part 16 are described separately, but they are provided continuously.

[0027] Since the liquid level detection float according to Example 3 has the above-described configuration, when a liquid flow occurs in the liquid storage tank 1, the bottom-side blade portions 15 and the side-side blade portions 16 are affected by the flow. Therefore, they are more strongly affected by the flow than the bottom-side blade portion 14 of Example 2. Also, since the length of the lower side of the bottom-side blade portion 15 is equal to or greater than that of the bottom-side blade portion 14 of Example 2, the ability to exclude sludge and the like from below the float portion 11 and scatter it around the float portion 11 can be enhanced as compared with the liquid level detection float according to Example 2.

Example

[0028] Figs. 4(A) to (D) are respectively a plan view, a front view, a bottom view, and a perspective view of the liquid level detection float according to Example 4. The liquid level detection float according to Example 4 is different from Example 3 only in that the eight side-side blade portions 17 provided on the side surface of the float portion 11 are spiral. Therefore, the description of the configuration other than the side-side blade portion 17 is omitted, and the same reference numerals as those in FIGS. 1 and 3 are used in the description of Example 4. As shown in FIGS. 4(B) and (D), the side-side blade portion 17 of Example 4 extends radially in eight directions around the central axis at 45-degree intervals from the side surface of the float portion 11 and is twisted in a spiral shape. The lower end surface coincides with the surface protruding from the side surface of the float portion 11 of the bottom-side blade portion 15, and the upper end surface is shifted by about 60 degrees from the lower end surface.

[0029] Since the liquid level detection float according to Example 4 has the above-described configuration, even when an upward flow or a downward flow occurs in the liquid storage tank 1, the spiral side-side blade portion 17 can catch the liquid flow and rotate the float portion 11.

Example

[0030] Figs. 5(A) to (D) are respectively a plan view, a front view, a bottom view, and a perspective view of the liquid level detection float according to Example 5. The liquid level detection float according to Example 5 is different from Example 3 in that the eight bottom-side blade parts 18 provided on the bottom surface of the float part 11 are shaped to spread wider downward, and the side-side blade part provided on the side surface of the float part 11 is a single spiral blade part 19. Therefore, the description of the configuration other than the bottom-side blade part 18 and the spiral blade part 19 will be omitted, and the same numbers as in FIGS. 1 and 3 will be used in the description of Example 5. As shown in FIGS. 5(C) and 5(D), the bottom-side blade part 18 of Example 5 extends radially in eight directions every 45 degrees from the surface where the wall surface of the through-hole 13 is extended straight downward, and the distance from the central axis of the float part 11 is larger on the lower side. Further, its cross-sectional shape is trapezoidal, the length of the upper side of the trapezoid is equal to the thickness of the float part 11, and the length of the lower side of the trapezoid is longer than the thickness of the float part 11. As shown in FIGS. 5(B) and 5(D), the spiral blade part 19 is composed of a single spiral plate that surrounds the side surface of the float part 11, and it revolves while rising from the lower end to the upper end of the side surface of the float part 11 for three turns. Note that the number of revolutions can be determined as appropriate.

[0031] Similar to the liquid level detection float according to Example 2, the liquid level detection float according to Example 5 has the above configuration, so that the lower side of the bottom-side blade part 18 is long, and when a liquid flow occurs in the liquid storage tank 1, it is more easily affected by the flow than the bottom-side blade part 12 of Example 1. Therefore, the bottom-side blade part 18 rotates efficiently, and sludge and the like can be excluded from below the float part 11 and scattered around the float part 11 in a wider range. Furthermore, since it has a side-side blade part 19 composed of a single spiral plate around the side surface of the float part 11, even when an upward flow or a downward flow occurs in the liquid storage tank 1, the side-side blade part 19 can catch the liquid flow and rotate the float part 11.

[0032] List modified examples regarding the liquid level detection floats according to Examples 1 to 5. (Modification Example 1) The float portion 11 in Examples 1 to 5 was cylindrical with a through-hole 13. However, as long as a through-hole 13 that can be inserted into the guide portion 10 is provided, it is not limited to a cylindrical shape, and as long as it is a cylindrical body, the cross-section cut by a plane orthogonal to the central axis of the float portion 11 may have any shape. However, in order to prevent inclination due to buoyancy, it is better for the cross-sectional shape to be bilaterally symmetric or rotationally symmetric. (Modification Example 2) The liquid level detection float according to Examples 1 to 5 has eight bottom-side blade portions 12, 14, 15, 18, and the liquid level detection floats according to Examples 3 and 4 further have eight side-side blade portions 16, 17, all of which extend radially in eight directions at 45-degree intervals from the central axis side of the float portion 11. However, a plurality of the eight bottom-side blade portions and side-side blade portions may be provided, and they may extend radially at equal intervals around the central axis from the central axis side of the float portion 11. (Modification Example 3) The lower end surfaces of the bottom-side blade portions 12, 14, 15, 18 in Examples 1 to 5 were all planes extending radially from the central axis of the float portion, but they may also be curved surfaces. In particular, when the bottom of the liquid storage tank 1 where the liquid level detection float is installed is a downwardly convex curved surface, if the surface is made parallel to the line with the smallest radius of curvature among the lines extending radially along the bottom from the intersection of the central axis of the float portion 11 and the bottom of the liquid storage tank 1, even if the float portion 11 approaches the bottom, the portions other than the innermost portions of the bottom-side blade portions 12, 14, 15, 18 will not contact the bottom, which is convenient. (Modification Example 4) The thicknesses of the bottom-side blade portions 12, 14, 15, 18 in Examples 1 to 5 were all uniform, but the thickness of the lower part of the bottom-side blade portion may be made thinner. For example, FIGS. 6(A) to 6(C) are respectively a front view, a bottom view, and a perspective view of the liquid level detection float according to Modification Example 4 of Example 1, and the bottom-side blade portion 20 thereof has a tapered portion 21 that becomes thinner toward the lower side at the lower part. And for the liquid level detection float according to Modification 4, when the lower end of the bottom-side blade part 20 hits sludge or the like accumulated at the bottom of the liquid storage tank 1, it can sink deeply and efficiently exclude the sludge or the like from below the float part 11 and scatter it around the float part 11. Further, since the tapered part 21 is likely to sink into sludge or the like accumulated at the bottom, there is also an effect that it is difficult for abnormal liquid level detection to occur.

[0033] (Modification 5) In Examples 1 to 5, the side surfaces of the bottom-side blade parts 12, 14, 15, 18 and the side surfaces of the side-side blade part 16 in Example 3 all extended radially from the central axis of the float part 11, but they may also be curved surfaces. In the case of the liquid level detection float according to Example 3 having the bottom-side blade part 15 and the side-side blade part 16, either one of the both side surfaces may be a curved surface. For example, FIGS. 7(A) to (C) are respectively a front view, a bottom view, and a perspective view of the liquid level detection float according to Modification 5 of Example 1, and the bottom-side blade part 22 thereof has a cross section cut by a plane orthogonal to the central axis of the float part 11 in an arc shape. Also, FIGS. 8(A) to (C) are respectively a front view, a bottom view, and a perspective view of the liquid level detection float according to Modification 5 of Example 2, and the bottom-side blade part 23 thereof has a cross section cut by a plane orthogonal to the central axis of the float part 11 in an arc shape. Furthermore, FIGS. 9(A) to (C) are respectively a front view, a bottom view, and a perspective view of the liquid level detection float according to Modification 5 of Example 3, and the bottom-side blade part 24 and the side-side blade part 25 thereof have cross sections cut by a plane orthogonal to the central axis of the float part 11 in an arc shape. And since the bottom-side blade parts 22, 23, 24 or the side-side blade part 25 of the liquid level detection float according to Modification 5 have cross sections cut by a plane orthogonal to the central axis of the float part 11 in an arc shape, they can efficiently receive the flow of the liquid generated in the liquid storage tank 1, and the float part 11 can be rotated even if the liquid flow is weak.

[0034] (Modification Example 6) In Examples 1 to 5, the bottom-side blade portions 12, 14, 15, and 18 all extend radially from a plane that extends directly below the wall surface of the through-hole 13. The cross-sectional shape is rectangular or square for the bottom-side blade portions 12 and 15, and trapezoidal for the bottom-side blade portions 14 and 18. However, the cross-sectional shape may be other than rectangular, square, or trapezoidal. For example, FIG. 10(A) is a cross-sectional view of a liquid-level detection float according to Modification Example 6 of Example 1, and FIG. 10(B) is a cross-sectional view of a liquid-level detection float according to Modification Example 6 of Example 2. And the cross-sectional shape of the bottom-side blade portions 26 and 27 of those liquid-level detection floats is triangular, and the lower surfaces of the bottom-side blade portions 26 and 27 are both inclined surfaces that incline obliquely downward and outward from the lower end portion of the wall surface of the through-hole 13. Also, the inclined surface may be a curved surface or a surface composed of a plurality of planes. Furthermore, the cross-sectional shape may be a trapezoid with the lower side shorter than the upper side. Note that even if the cross-section of the bottom-side blade portion is in the above-described shape, the obtained effect is not much different from the effect obtained by the liquid-level detection floats according to Examples 1 to 5. When the shape is as shown in FIG. 10(A) or (B), when the lower ends of the bottom-side blade portions 26 and 27 hit sludge or the like accumulated at the bottom of the liquid storage tank 1, it has the effect that it is difficult to sink and abnormal liquid level detection is less likely to occur.

[0035] (Modification Example 7) In Example 3, the bottom-side blade portion 15 and the side-side blade portion 16 were provided continuously, but they do not have to be continuous. For example, FIGS. 11(A) to (C) are respectively a front view, a bottom view, and a perspective view of a liquid-level detection float according to Modification Example 7 of the bottom-side blade portion 15 and the side-side blade portion 16 in Example 3. However, the bottom-side blade portion 28 and the side-side blade portion 29 are not connected and are provided with a 22.5-degree shift. And even with such a configuration, the obtained effect is not much different from the effect obtained by the liquid-level detection float according to Example 3. (Modification Example 8) The side wing root portions 16 in the third embodiment and the side wing root portions 17 in the fourth embodiment were provided continuously from the lower end to the upper end of the float portion 11. However, either of them may be provided continuously from the lower end or the lower part to the upper part, or may be provided continuously from the lower part to the upper end or the upper part. Further, it may be provided intermittently from the lower end or the lower part to the upper end or the upper part.

Description of Reference Numerals

[0036] 1 Liquid storage tank 2 Liquid injection pipe 3 Liquid discharge pipe 4 Magnetostrictive liquid level gauge 5 Detection unit 6 Magnetostrictive wire 7 Upper liquid level detection float 8 Lower liquid level detection float 9 Liquid level data transmission unit 10 Guide unit 11 Float portion 12 Bottom wing root portion 13 Through hole 14, 15 Bottom wing root portions 16, 17 Side wing root portions 18 Bottom wing root portion 19 Spiral wing root portion 20 Bottom wing root portion 21 Tapered portion 22, 23, 24 Bottom wing root portions 25 Side wing root portion 26, 27, 28 Bottom wing root portions 29 Side wing root portion P Pump M Flow meter

Claims

1. A liquid level detection float having a cylindrical float portion that is vertically movably attached to a guide portion extending vertically and provided in a liquid storage tank, A plurality of bottom-side blade portions extending radially from the central axis side of the float portion are provided on the bottom surface of the float portion, A plurality of side-side blade portions extending radially from the central axis side of the float portion are provided on the side surface of the float portion, The bottom-side blade portions and the side-side blade portions are provided continuously. A liquid level detection float characterized by the above.

2. The bottom-side blade portions are such that the distance from the central axis of the float portion increases toward the lower side. The liquid level detection float according to claim 1, characterized by the above.

3. The lower part of the bottom-side blade portions becomes thinner toward the lower side. The liquid level detection float according to claim 1, characterized by the above.

4. The cross-section of the bottom-side blade portions or the side-side blade portions cut by a plane orthogonal to the central axis of the float portion is arc-shaped. The liquid level detection float according to claim 1, characterized by the above.

Images