JPH0619059Y2 - Float for liquid level gauge - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a float used in a magnet type liquid level gauge.

[Prior Art and Its Deficiencies] A large number of blade-shaped rotors made of a magnetic material are arranged vertically and vertically in a single vertical rotor housing, and the rotors are arranged to rotate about a horizontal axis. A magnet-type liquid level gauge in which a rotor unit, which is supported by a rotor shaft on a housing, is attached to the outer peripheral surface of one vertical cylindrical housing having a float inside,
It is used to measure the amount of liquid remaining in the tank.

In such a liquid level meter, a magnetic force generating unit having a structure in which a yoke made of a plate-shaped magnetic body is sandwiched between two upper and lower annular magnets arranged so that the same poles face each other is provided in the float. There is something.

In such a magnetic force generation unit, it is suitable when a magnetic material to be driven, a reed switch, or the like is used while being appropriately separated from the magnet.

However, in the magnetic force generation unit 20 in which the annular magnets 19 and 19 having a thickness t and a diameter B shown in FIGS. 5 and 6 are arranged vertically with a space d so that the same poles face each other, As shown in FIG. 7, which shows the characteristic curve in which the horizontal axis is the distance 1 to the magnetic force measurement point A and the vertical axis is the magnetic force when d is 0 mm, 2 mm, 5 mm, and 12 mm, as shown in FIG. It can be seen that if the distance d is appropriately set, a magnetic force sufficient to drive the magnetic body, the reed switch, or the like can be obtained without forming the magnetic force generation unit between the magnets via the yoke.

Further, in the magnetic force generation unit 20 in which the diameter B of the magnet is 31.41 mm, the diameter C of the central cavity is 18.53 mm, and the thickness t of the magnet is 6.03 mm, the distance l to the magnetic force measurement point A is 1.
FIGS. 8 to 11 show characteristic curve diagrams of the distance d between the magnets and the magnetic force when the values are 11 mm, 16 mm, 21 mm and 30 mm.

As is clear from these characteristic curve diagrams, the magnetic force at the magnetic force measurement point A can be adjusted by changing the interval d.

For example, when the magnets in the float and the rotors in the rotor unit are magnetically coupled for normal operation, the distance d between the magnets may be set so that the magnetic force at the rotor position is within the range of 25 to 200 Gauss. .

Since the magnetic force of the magnet is also related to the thickness t of the magnet, the magnetic force increases when t is thick, so the gap d is widened to an appropriate magnetic force, and when t is thin, the magnetic force decreases. Since it is necessary to widen the distance d to obtain an appropriate magnetic force, in the relation between the distance d and the thickness t, if d is adjusted within a range of about t ≦ d ≦ 10t, a yoke is interposed between the magnets. A magnetic force almost equal to that of the magnetic force generating unit can be obtained.

In addition, the magnetic force generation unit in which the yoke is interposed between the magnets increases the weight of the magnetic force generation unit itself due to the yoke made of a magnetic material, and when used in a tank that stores a liquid of low specific gravity, in order to float the float. Since it becomes necessary to make the casing of the float as thin as possible, the pressure resistance of the float pressure receiving portion below the liquid surface decreases.

[Purpose of the Invention] The present invention is a magnet type liquid level gauge which knows the liquid level by a rotor magnetically coupled to a magnet in a float, and can magnetically couple favorably to a rotor located at a position appropriately separated from the float. A float for a liquid level gauge suitable for a liquid having a low specific gravity can be provided.

[Means] In the float for a liquid level gauge according to the present invention, two magnets having the same thickness are inserted in a hollow case made of a non-magnetic material, and a spacer made of a non-magnetic material is interposed between the magnets so that they have the same pole. Assuming that the magnets are vertically arranged so as to face each other, the distance between both magnets is d, and the thickness of each magnet is t, the distance d between both magnets is t ≦ d ≦ 10t.
It is provided so as to have a relationship of.

[Operation] Since two magnets having a thickness t arranged above and below have the same poles facing each other and the distance d between the two magnets is set to t ≦ d ≦ 10, a magnetic force generation unit having the same diameter and having a yoke is formed. It is possible to obtain almost the same magnetic force.

Further, since it is not necessary to provide a yoke made of a magnetic material between the magnets, the weight can be reduced accordingly.

[Embodiment] Next, an embodiment of the float according to the present invention will be described in detail with reference to FIGS.

Reference numeral 1 is a cylindrical float having a hollow interior made of a non-magnetic material, and a magnetic force generating unit 2 is provided at an appropriate place inside the float.

The magnetic force generating unit 2 is composed of a magnet portion and its fixed structure portion, and this magnet portion is as follows.

Upper magnet with thickness t and fitting hole 3a 'in the center
3a and a lower magnet 3b having the same shape as the upper magnet 3a and provided with a fitting hole 3b 'are arranged vertically so that, for example, N poles face each other, and the fitting hole 3b is provided between these magnets.
Fitting protrusions 4a, 4b having substantially the same diameter as a ', 3b' and height t
And an annular spacer 4 made of a non-magnetic material and having a central cavity 4c which is a through hole and having a height d. The fitting protrusion 4a is provided in the fitting hole 3a ′ of the upper magnet 3a, and the fitting protrusion 4b is provided. Bottom magnet 3b
, And the space between the upper and lower magnets is d.
It is designed to be

The fixing structure of the magnet part is as follows, for example.

While its outer edge is almost in contact with the inner peripheral surface of the float 1,
A plate-shaped upper plate 5a formed so as to form an opening having the same diameter as that of the central cavity portion c of the spacer 4 is arranged on the upper surface of the upper magnet 3a, and a convex portion 6a which can be inserted into the central cavity portion 4c is provided. An upper boss 6 having a screw hole 6b formed in the center of the upper boss 6a is disposed so that the convex portion 6a is inserted into the central cavity 4c from the upper surface of the upper plate 5a, and is the same as the upper plate 5a. The lower plate 5b formed on the lower magnet 3b is disposed on the lower surface of the lower magnet 3b, and the lower boss 7 having the same convex portion 7a as the upper boss 6 and the screw hole 7b is provided from the lower surface to the convex portion 7a in the central cavity 4c. A nut 8 having a length capable of penetrating between the upper and lower bosses, for example, by screwing from the upper surface of the upper boss 6 to the lower boss 7, and the upper surface of the lower magnet 3b on the lower surface of the upper magnet 3a. Between, for example, its height d
The spacer 4 with 2t is fixed.

Further, the magnetic force generating unit 2 configured as described above is attached to the upper surface of the upper plate 5a and the float 1 with the L-shaped metal fitting 9, for example.
Inner peripheral surface of 3 places, lower surface of lower plate 5b and float 1
The inner peripheral surface of is attached at three points and fixed in the float.

An embodiment in which the liquid level gauge float configured as described above is used in a liquid level gauge will be described with reference to FIG.

The float 1 is enclosed in a cylindrical housing 10 formed to have an inner diameter slightly larger than the outer peripheral surface of the float 1, and the outer peripheral surface of the cylindrical housing 10 is supported by a rotor shaft 11b so as to be rotatable about a horizontal axis. A liquid level gauge 12 is formed by mounting a box-shaped rotor housing 11 having a large number of rotors 11a arranged in the vertical direction and being long in the vertical direction.

At this time, the tangent line of the outer peripheral surface of the cylindrical housing 10 to which the rotor housing 11 is attached is made substantially parallel to the rotor shaft 11b, and the side surface portion of the rotor housing 11 facing the side surface portion in contact with the cylindrical housing 10 is Transparent material
It is formed by 11c.

Then, the communication pipe 1 is provided to the upper and lower portions of the peripheral surface of the cylindrical housing 10 that faces the surface to which the rotor housing 11 is connected, for example.
3 and 14 are attached vertically to the peripheral surface, and flanges 13a and 14a are formed on the end surfaces of these communicating pipes 13 and 14 to form a tank.
At appropriate places on the circumferential surface of 15, the communication pipes 16 and 17 having flange portions 16a and 17a formed on the end faces are provided at two upper and lower positions which can be connected to the communication pipes 13 and 14 provided on the liquid level gauge. 13a and 1
The inside of the tank 15 and the inside of the cylindrical housing 10 are made to communicate by connecting 6a to 14a and 17a, respectively.

As described above, in the case where the magnet type liquid level gauge equipped with the float according to the present invention is connected to the tank, when the liquid 18 is injected into the tank, even if the liquid 18 has a low specific gravity,
The float 1 can be easily moved to the cylindrical housing as the liquid level rises.
Ascend within 10.

Then, the magnetic force generation unit 2 in the rotor located near the liquid surface is magnetically coupled to the rotor 11 in the vicinity, and the magnetic coupling force decreases as the distance from the rotor 11 increases as the liquid level changes. The magnetic flux is again magnetically coupled to the rotor 11 and is sequentially magnetically coupled to the rotor 11 which is closest to the liquid surface, so that the change in the liquid level is indicated by the rotor 11.

[Effect] In the float for the liquid level gauge according to the present invention, the thickness t is 2
Since two magnets are arranged vertically with the same poles facing each other and the distance d between the magnets is set to be t or more and 10t or less, it is almost the same as the magnetic force generation unit in which a yoke is interposed between the upper and lower magnets. The magnetic force is obtained, and the magnetic force can be effectively magnetically coupled to the rotor located at a position separated from the magnetic force generation unit to some extent.

Further, since the magnetic force generating unit in which the yoke made of a magnetic material is not interposed between the magnets is provided in the float,
It becomes lighter by that amount, and buoyancy can be easily obtained even with low specific gravity liquid, and it is also possible to improve the strength against the pressure received from the liquid in the tank by increasing the thickness of the float by the weight reduction. .

[Brief description of drawings]

1 is a vertical sectional front view of a float according to the present invention, FIG. 2 is a sectional view taken along line II-II of FIG. 1, FIG. 3 is a sectional view taken along line III-III of FIG. 1, and FIG. FIG. 3 is a partially cutaway vertical front view in which a liquid level gauge using the float according to FIG. 5 is a front view of the magnetic force generating unit, FIG. 6 is a plan view of a magnet used in the magnetic force generating unit, and FIG. 7 is a magnetic force generating unit 20.
Distance l to the magnetic force measurement point A when the distance d of is changed
And FIG. 8 is a characteristic curve diagram showing the relationship between the magnetic force and the magnetic force. FIG. 8 is a characteristic curve diagram showing the relationship between the distance d and the magnetic force when the distance 1 to the magnetic force measurement point A is 11 mm. Fig. 10 is a characteristic curve diagram showing the relationship between the distance d and the magnetic force when the distance 1 to A is 16 mm. Fig. 10 shows the distance d and the magnetic force when the distance 1 to the magnetic force measurement point A is 21 mm. Characteristic curve diagram showing the relationship between
Figure 11 shows the case where the distance l to the magnetic force measurement point A is 30 mm.
It is a characteristic curve figure which shows the relationship between the space | interval d and magnetic force. In the figure 1 ... Float 2 ... Magnetic force generating unit 3a ... Upper magnet, 3a '... Fitting hole 3b ... Lower magnet, 3b' ... Fitting hole 4 ... Spacers 4a, 4b ... Fitting protrusion, 4c ... Central cavity 5a ... Upper plate 5b ... Lower plate, 6 ... Upper boss 6a ... Projection, 6b ... Screw hole 7 ... Lower boss, 7a ... Concave 7b ... Screw hole, 8 ... Nut 9 ... L-shaped metal fitting 10 ... Cylindrical housing 11 ... Rotor Housing 11a ... Rotor, 11b ... Rotor shaft 12 ... Liquid level gauge, 13 ... Communication pipe 13a ... Flange part, 14 ... Communication pipe, 14a ... Flange part, 15 ... Tank 16 ... Communication pipe 16a ... Flange part, 17 ... Connection Tube 17a ... Flange part, 18 ... Liquid 19,19 ... Toroidal magnet 20 ... Magnetic force generating unit

Claims (1)

[Scope of utility model registration request] 1. A hollow case made of a non-magnetic material, in which two magnets having the same thickness are provided vertically so that the same poles face each other with a spacer made of a non-magnetic material interposed therebetween. A float for a liquid level gauge in which both magnets are provided so that the distance d has a relationship of t ≦ d ≦ 10t, where d is a distance between the magnets and t is a thickness of each magnet.