JP2724058B2 - Hydrometer and water level meter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydrometer and a water level meter capable of accurately reading the specific gravity and level (water level) of a liquid with a simple structure.

[0002]

2. Description of the Related Art As a device for measuring the specific gravity of a liquid, a device for putting a float in the liquid and measuring the specific gravity based on the ups and downs of the float has been put to practical use. That is, it is possible to detect that the float has a specific gravity to be measured, and that when the float floats, the specific gravity of the liquid is smaller than the specific gravity, and when the float floats, the specific gravity is larger than the specific gravity.

[0003]

However, such a hydrometer has a disadvantage that it can only measure whether the specific gravity of the liquid is larger or smaller than a certain value. Also, with such a configuration, it was impossible to measure the liquid level of the liquid.

An object of the present invention is to provide a hydrometer and a water level meter that can perform linear measurement with a simple configuration.

[0005]

Means for Solving the Problems] hydrometer of this invention, an elastic member for locking the weight or float is installed by introducing in the liquid at one end, the other end of the elastic member and a base portion for supporting the Hall element to one of the elastic body and the base portion, provided with opposed magnets respectively on the other, the weight
Alternatively, close the other end than the one end of the elastic body locked with the float.
It is characterized by being closed .

A water level gauge according to the present invention comprises a weight or a float having a length extending over substantially the entire depth of a liquid tank across a fluctuating liquid level, an elastic body for locking the weight or the float, and an elastic body. and a base portion for supporting the, one to the Hall element of the elastic body and base portions, provided respectively facing the magnet to the other, the weight or float, the cross-sectional shape of the liquid tank
It is characterized by being substantially similar to the cross-sectional shape of the metal .

[0007]

In the hydrometer according to the present invention, a weight or a float is provided so as to be submerged in the liquid, and the weight or the float is locked to one end of the elastic body. The other end of the elastic body is fixed to the base. And this hydrometer locks the weight or float
The other end of the elastic body except for one end is sealed. Since the volume of the weight or the float is constant, the buoyancy acting on the weight or the float is proportional to the specific gravity of the liquid.

A buoyancy (or a weight reduced by the buoyancy) acts on the elastic body that locks the weight or the float, thereby deforming the elastic body. Since the Hall element and the magnet are provided opposite to each other on the elastic body and the base, the distance between the Hall element and the magnet fluctuates due to this deformation. If a constant bias current is passed through the Hall element, a voltage proportional to the strength of the magnetic field, that is, a distance from the magnet is output from the output terminal. By scaling this output voltage, the specific gravity of the liquid can be detected. The hydrometer is an elastic body that locks the weight or float.
Of the hydrometer is closed, except for one end of the
It can be used by immersing it inside. In this case, the elastic
Attach a weight or a thread to one end of the body
Measurement error due to liquid shake, etc.
Can be done.

Further, the water level gauge of the present invention has a depth of the liquid tank.
Fluctuating weights or floats of almost the entire length in the vertical direction
It was provided so as to straddle the liquid level. Depending on the level of the liquid (water level), the volume of the weight or the float submerged in the liquid fluctuates,
The buoyancy it receives also fluctuates. The variation of the buoyancy by detecting a variation in the output voltage of the Hall element in the same manner as described above hydrometer, can detect the level of the liquid. Sa
In addition, the weight or float is similar to the cross-sectional shape of the liquid tank.
What is the shape of the liquid tank?
Output in proportion to the amount of liquid in the liquid tank
Can be. In other words, what is the shape of the liquid tank?
Can detect the amount of liquid in the liquid tank.
You.

[0010]

1 is an external view of a hydrometer according to an embodiment of the present invention, and FIG. 2 is a schematic configuration diagram of the hydrometer. Specific gravity meter body 1
Is a box shape made of polypropylene, and has a Hall element 4, a base 7, and a circuit section 8 inside. Also,
A leaf spring (elastic body) 2 is fixed to the base 7 with screws. The leaf spring 2 protrudes in a tongue shape from a notch in the upper part of the main body 1, and a portion where the leaf spring 2 protrudes from the main body 1 is sealed with a silicone resin. A minute magnet 3 is fixed to the lower surface of the leaf spring 2. The magnet 3 is fixed at a position facing the Hall element 4 so as to be covered with a silicone resin. The weight 5 is locked to the free end of the leaf spring 2 by the thread 6. A hole 1a is formed in the main body 1 so that the thread 6 passes below the main body 1. At the time of using the hydrometer, at least the weight 5 locked on the thread 6 is immersed in the liquid. The notch of the main body 1 is closed by a lid 9.

FIG. 3 is a diagram showing a schematic configuration of the circuit section 8. As shown in FIG. A bias voltage Vb is applied to the Hall element 4. This bias voltage Vb is a constant voltage of about 1.8V. That is, the Hall element is driven at a constant voltage. Both detection electrodes of the Hall element 4 are connected to input terminals of the operational amplifier 20. The amplifier 20 amplifies a potential difference between both electrodes of the Hall element 4. This output is output from the operational amplifier 21
Is input to one of the terminals. A bias voltage is input to the other terminal via the volume 23. This bias voltage is a bias voltage for setting the zero point of the output. The output of the operational amplifier 21 is further amplified by the amplifier 22. A volume 24 is inserted between the amplifier 21 and the amplifier 22 so that the gain can be adjusted. After setting the hydrometer, the volumes 23 and 24 can be appropriately adjusted to perform scaling according to the measurement object.

When the weight 5 is immersed in the liquid, it receives buoyancy according to the specific gravity of the liquid, and the weight applied to the thread 6-leaf spring 2 decreases. At this time, if the weight (force) applied to the thread 6 is F, the weight of the weight 5 in the air is W, the volume of the weight 5 is V, and the specific gravity of the liquid is α, then F = W−αV. Therefore, when the specific gravity α changes, F also changes. By the way, the leaf spring 2 generates a deflection δ according to the force F applied to the free end. The deflection δ is proportional to F in a small range of the deflection δ. The deflection δ at the tip and the deflection at the position of the magnet 3 are also proportional in a minute range. The distance between the magnet 3 and the Hall element 4 and the power generation output of the Hall element 4 have a proportional relationship (linear function relationship) within an appropriate distance range. Therefore, the detected specific gravity can be output as a desired voltage value by adjusting the zero point with the volume control 23 and adjusting the gain appropriately with the volume control 24. It can also be used as input to the device.

FIGS. 4A, 4B, and 4C are views showing an embodiment in which the hydrometer is used in a liquid tank.
FIG. 2A shows a support 13 provided above the liquid tank 11.
This is an example in which a hydrometer 1 is installed. Specific gravity meter 1 to weight 5
In the liquid. The support 13 can use a tank lid. FIG. 2B shows an example in which the support base is provided in the liquid and the main body 1 is also immersed in the liquid.
In the hydrometer main body 1 of this embodiment, only the free end of the leaf spring 2 needs to be exposed in the liquid, and the other parts can be hermetically sealed. It can be operated without any trouble. By immersing in the liquid in this manner, the length of the thread 6 can be shortened, and measurement errors due to shaking and the like can be reduced.

FIG. 2C shows a float 1 instead of the weight 5.
0 shows an example where 0 is attached to the thread 6. Float 10 is liquid 1
Since the specific gravity is smaller than 3, the buoyancy is greater than the specific gravity, and it tends to rise. Therefore, the hydrometer main body 1 is installed on the bottom surface of the liquid tank, and a downward force is applied to the float 10 using the thread 6 and the leaf spring 2 to stop the float. In this method, F = αV−W, so that F can be reduced, and the fluctuation rate of F can be increased even with a small change in α. Even when the weight 5 is installed, it is possible to reduce F by bringing W close to αV, but in this case, the specific gravity of the weight becomes close to the specific gravity of the liquid, and the weight becomes unstable in the liquid. There is. In addition,
When the level of the liquid surface does not fluctuate at all as in still water, the weight and the float can be installed in a state where a part of the weight and the float are exposed above the liquid.

Although the above specific gravity meter has been described as an apparatus for measuring the specific gravity of a liquid (ratio with the density of water at 4 ° C.),
It can be applied as a device for measuring the density of liquid (mass per fixed volume (1 cm ³ )) with exactly the same configuration.

FIG. 5 is a diagram showing a level meter (water level meter) according to an embodiment of the present invention. In this figure, the level meter main body 30 has exactly the same configuration as the above-mentioned specific gravity meter main body 1, and therefore the description is omitted. In the case of the level meter, the weight 31 suspended by the thread 6 is much longer than the specific gravity meter. This is because the measurement range is determined by the length of these weights. That is, the part of the weight 31 in the liquid that is in the liquid is lightened by the buoyancy, and the part in the air has the same weight, so that the length of the part that is submerged in the liquid and the part that is in the air Level is detected by length. Therefore, because all can not measure the more severe the thus immersed in the liquid, all can not be measured is and its been following level would appear in the air. The vertical movement of the weight 31
Is small compared to the change in the liquid level. sand
That is, the amount of liquid in the liquid tank 11 (the height of the liquid surface) changes.
Also, the weight 31 hardly moves in the vertical direction. Here, F = W-αax. Here, a is the cross-sectional area of the weight, and x is the length submerged in the liquid. The liquid level can be read by this F (the weight applied to the thread 6 and the leaf spring 2). Also in this level meter, by appropriately adjusting the volumes 23 and 24, scaling in which the output voltage and the actual level are accurately associated can be performed.

In this embodiment, the weight 31 is hung down, but the float is pulled down (FIG. 4C).
May be adopted). In this case, measurement can be performed in a range where the buoyancy received by the part in the liquid is greater than the weight of the part in the air.

Further, when the liquid tank is not a rectangular parallelepiped or cylindrical uniform shape, for example, a pot shape as shown in FIG. 6, the weight has the same shape (a shape obtained by reducing the shape of the tank horizontally). By doing so, the output voltage becomes proportional to the liquid amount instead of the liquid level.

That is, in a portion where the cross-sectional area of the tank is large, the cross-sectional area of the weight is large, and the buoyancy is increased. With such a configuration, the change in the buoyancy received by the weight and the change in the amount of liquid are proportional to each other, so that an output proportional to the liquid amount can be obtained regardless of the shape of the tank. become.

When measuring the level of a liquid whose specific gravity fluctuates, it may be used in combination with the above specific gravity meter.

The structure of the main body is not limited to those shown in FIGS. 1 and 2, but may be formed by using a coil spring as shown in FIGS. 7 (A) and 7 (B). Further, any configuration may be used as long as it uses an elastic body.

[0022]

As it is evident from the foregoing description, according to the invention as set forth in claim 1, it is possible to detect the specific gravity of the liquid with a simple structure, leading to cost reduction, and since sealing is possible , You can use the hydrometer body immersed in the liquid
it can. In this case, a weight or weight is attached to one end of the elastic body.
Threads to lock the float can be shortened,
Measurement errors due to shaking or the like can be reduced. Ma
According to the invention described in claim 2, the weight or the float is provided.
Has a shape similar to the cross-sectional shape of the liquid tank.
Therefore, regardless of the shape of the liquid tank,
It is possible to obtain an output proportional to the amount of liquid in the chamber. Sand
That is, regardless of the shape of the liquid tank,
The liquid amount in the ink can be detected.

[Brief description of the drawings]

FIG. 1 is a perspective view of a hydrometer according to an embodiment of the present invention.

FIG. 2 is a schematic structural diagram of the hydrometer.

FIG. 3 is a diagram showing a configuration of a circuit unit of the hydrometer.

FIG. 4 is a diagram showing a mode of use of the hydrometer.

FIG. 5 is a diagram showing a use mode of the level meter according to the embodiment of the present invention;

FIG. 6 is a diagram showing another embodiment of the level meter.

FIG. 7 is a diagram showing another embodiment of the present invention.

[Explanation of symbols]

2-leaf spring (elastic body), 3-magnet, 4-Hall element,
5, 31, 33-weight, 10-float.

Claims (2)

(57) [Claims] 1. A weight or a float which is placed by being introduced into a liquid
One elastic member for engaging an end portion of the other of the elastic body
A base for supporting an end , a hall element provided on one of the elastic body and the base, and a magnet provided on the other, facing each other, and one end of the elastic body locking a weight or a float. Other than
A hydrometer characterized by being sealed . 2. The depth of a liquid tank across a fluctuating liquid level
A weight or a float having a length that extends over substantially the entire direction, an elastic body that locks the weight or the float, and a base that supports the elastic body, and a hall element on one of the elastic body and the base. on the other hand the opposed magnets respectively, the weight or float is cross sectional shape of the liquid tank
A water level gauge characterized by being substantially similar to a surface shape .