JP2001317985A - Liquid level sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simple facility for monitoring and controlling liquid level data which change every moment at a deteriorated environmental place, such as a waste liquid treatment tank or the like. SOLUTION: The liquid level sensor comprises a float 4 for measuring the liquid level data, a float winding sheave 5, a winding spring 6, and a rotary position sensor 8. By shutting of the ventilation between the former and the latter the sensor is made strong against the environment, and by connecting the sheave 5 and the sensor 8 by an accelerating mechanism, the sensor which is simple, convenient and highly accurate and highly reliable is constituted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid level transmission system, and more particularly to a liquid level sensor installed in a specific tank, which measures the liquid level condition at the installation position every moment and controls the data from a remote place. , And the equipment to be used for management.

[0002]

2. Description of the Related Art Conventionally, when using such liquid level data at a remote place, measured values of some environmental sensors, for example, capacitance, pressure, and optical sensors, are converted into electrical data and converted. The data was transmitted via a wireless device or by wire to try to use it at a remote location. Such facilities are often used particularly in places where environmental conditions are poor, such as tanks for treating various kinds of waste liquids. However, in such a waste liquid treatment tank, the precipitates, suspended solids, and PH values in the aqueous solution also change variously depending on the treatment chemicals and the like corresponding to the object to be treated. There are also problems such as physical property values of the aqueous solution that affect the accuracy of the measurement values of the various sensors, for example, changes in dielectric constant, dirt, changes in resistance value, and odor. In addition, even in the case of the float type in which these physical property values are not used for measurement, there is a possibility that suspended matter may adhere to the float and adversely affect the measurement accuracy.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and minimizes the components installed in places where the environmental conditions are poor, for example, various waste liquid treatment tanks. In addition, it was necessary to optimize the materials used for the processing solution. In addition, it is necessary to improve the durability and reliability of components such as electronic components that are particularly vulnerable to contamination due to passage of contaminants such as vapor due to air permeability and water permeability with the tank side.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and firstly, a float is attached to a connecting part which moves up and down by a float hoisting pulley, and mechanical displacement of the float is used to rotate the pulley. Angle, and then convert the rotation angle into an electrical signal converter.
For example, an electric signal is generated by a potentiometer and used for controlling the apparatus. Insulation is completely insulated from liquids where the environmental conditions are inferior, i.e., the float is the only component to be installed in the tank, and the connecting component that moves up and down by the float hoisting pulley is incorporated in a guide pipe made of resin. To increase acid, alkali and corrosion resistance. In addition, the float and a part of the connecting component are connected by a magnet to shut off contaminants in the tank, thereby improving the durability and reliability of each component due to the environmental conditions in the tank. However, the guide pipe of this connecting part does not have to be installed as necessary.

Further, according to the present invention, the shape of the float is set so that, in the state of use, the float is directed from a slightly upper portion to a lower portion thereof and from a slightly lower portion of the upper surface to an upper portion thereof. Since the cross-sectional area is reduced, adhesion of suspended matter is reduced, and measurement accuracy is improved. In addition, a safety device for maintenance and inspection and reliability during use are improved by providing a device for preventing a connecting part of the hoisting pulley portion and the float from falling off from the hoisting pulley.

[0006]

FIG. 1 is a block diagram showing an embodiment of the present invention.
Description will be made based on 0. FIG. 10 is a diagram showing one embodiment of the present invention. FIG. 1 shows a main liquid level sensor 3 mounted inside a control panel 2 installed on an upper portion of a tank 1. Such a waste liquid tank is usually installed in a place where environmental conditions are poor, such as outdoors, so when it is necessary to control the liquid level, it is waterproof for control parts such as a board.
It is particularly important to consider dust and heat resistance. That is, it is desired to shut off contaminants in the control panel 2, the waste liquid tank, and the external environment.

Next, the configuration of the liquid level sensor 3 will be described. 1, 2, 3, and 4 show an embodiment of the present liquid level sensor 3. The liquid level sensor 3 includes a float 4 in the tank which moves up and down following a change in the liquid level in the tank, a hoisting pulley portion 5 connected to the float 4, and a hoisting pulley portion 5 which responds to the fluctuation of the float 4. And a fixed shaft that supports the rotating shaft of the hoisting pulley portion 5 to ensure smooth rotation, and a detection sensor 8 that detects the rotational position of the rotating shaft of the hoisting pulley portion 5. I have.

[0008] Float 4 is in the waste liquor to be treated and is made of a resin such as vinyl chloride, polypropylene, ABS, and polyethylene to increase acid, base and corrosion resistance. Also, in order to prevent the adhesion of suspended solids in the waste liquid and increase the measurement accuracy, the cross-sectional area is reduced from a slightly upper part near the liquid surface to a lower part. The float has a weight of about 100 g or more in order to minimize the effects of vibration due to pulsation by the pump of the processing liquid and vertical movement due to the inflow. It is desired that the projection protrudes about 20 mm or more from the liquid level. Further, since the outer diameter of the float is limited due to the size limit of the apparatus, the length thereof is desirably 1.5 times or less the outer diameter in order to reduce the hysteresis error above and below the float. Further, since this hysteresis error is also affected by the magnitude of the mechanical loss of each part of the liquid level sensor as shown in FIG. 12, the contact portion of the rotating component is pointed without using a bearing with a low load and a large mechanical loss. It is desirable to slide with contact and minimum line contact.

The hoisting pulley portion 5 connected to the float 4 is usually connected to the float 4 with a stainless steel wire, and is often installed directly above the float 4 and is installed inside the control panel 2. In this case, it becomes impossible to shut off contaminants in the control panel 2, the waste liquid tank, and the external environment. For this reason, it is desirable to be installed just above the float 4 and outside the control panel 2.

[0010] Since the winding spring 6 is mostly made of metal such as stainless steel or spring steel, there is a problem in corrosion resistance and acid resistance. Further, since the detection sensor 8 for detecting the rotational position of the rotating shaft of the hoisting pulley unit 5 and the other electronic components are required to be dust-proof and heat-resistant in addition to the above-mentioned problems, it is preferable to install them inside the control panel 2. Is desirable. For this reason, it is possible to adopt a configuration that incorporates a sealed bearing in the bearing part and another independent seal in order to block contaminants in the tank between the hoisting pulley part connected to the float in the tank and other components Good.

Furthermore, by connecting the hoist pulley 5 and the hoist spring 6 and a sensor 8 for detecting the rotational position thereof coaxially, the measurement accuracy is improved with a simple structure. Specifically, the detection sensor 8 uses a potentiometer or a digital output encoder. In particular, when a multi-rotation type detection sensor 8 is used to improve the position resolution, the hoisting pulley portion 5 is usually connected to the float 4 by a stainless steel wire. However, when the stroke of the float 4 is small due to the limitation of the bending radius of the wire, the rotation speed of the detection sensor 8 may not be secured. In such a case, the number of rotations of the multi-rotation type detection sensor 8 is secured by connecting the hoisting pulley portion 5 and the sensor 8 for detecting the rotational position thereof via a speed increasing mechanism, thereby improving accuracy. It is possible to raise. For this speed increasing mechanism, a planetary gear, a bevel gear, and a crown gear are usually used.

Another embodiment of the present invention will be listed. FIG. 6 is a diagram showing another embodiment of the present invention. As shown in FIGS. 7, 8, and 9, the float in the tank and the connecting part 11 connected to the hoisting pulley 5 are contactlessly connected via a magnetic coupling, so that the liquid Contaminants in the tank from the float inside to the other components of the level sensor are completely blocked.

An embodiment of the present invention will be listed. FIG. 3 is a diagram showing the internal configuration of the present invention. The pulley portion 5 of FIG. 2 is incorporated in the liquid level sensor 3, and a winding spring 6 is further incorporated in the inside of the pulley portion 5, so that the pulley portion 5 is operated in accordance with the rotation of the pulley portion 5 about a fixed axis. Things. By doing so, the structure becomes compact, but on the other hand, the spring contracts in the circumferential direction at the same time as the rotation, so that a rib is provided at the contact portion between the spring and the pulley to make the sliding point contact and mechanical loss. Has been reduced.

[0014] Further embodiments of the invention are listed. FIG. 11 is a view showing a float of the present invention. A metal weight and a shaping resin film are added to the float formed in advance in order to maintain the above-mentioned float characteristics.

The liquid level sensor according to the present invention is not limited to the electric transmission type, but may be an ordinary on-site indicating liquid level sensor.

[0016]

According to the present invention, there is provided a waste liquid treatment tank in which the presence of precipitates and suspended matter in an aqueous solution, and the physical properties of the aqueous solution which affect the accuracy of the PH value and the measured value are variously changed. A float type liquid level sensor capable of stably measuring the liquid level can be provided. Also, the durability and reliability of the parts used can be improved.

[0017]

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of the present invention.

FIG. 2 is a diagram showing an internal configuration of the present invention.

FIG. 3 is a diagram showing an internal configuration of the present invention.

FIG. 4 is a diagram showing a liquid level sensor display unit of the present invention.

FIG. 5 is a diagram showing another embodiment of the present invention.

FIG. 6 is a view showing still another embodiment of the present invention.

FIG. 7 is a diagram showing connection of the float of FIG. 6 and a connection component by a magnet.

8 is a diagram showing the connection of the float of FIG. 6 and a connecting part by a magnet.

FIG. 9 is a view showing a float of FIG. 6 and a method of guiding a connection part;

FIG. 10 is a diagram showing an embodiment for drip-proof, explosion-proof, and dust-proof.

FIG. 11 is a view showing an embodiment of a float 4. Usually, this float is made of resin. As a manufacturing method thereof, it is manufactured by injection molding or blow molding. In order to achieve a stable operation of the float, a metal having a large specific gravity is often inserted to give a center of gravity to a lower portion thereof.

FIG. 12 is a diagram showing the relationship between the movement of the float and the mechanical loss. In order to reduce the mechanical loss, each bearing is formed as a point contact or a line contact without using a bearing having a large mechanical loss.

FIG. 13 is a diagram showing details of a pulley unit.

[0018]

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tank 2 Control board 3 Liquid level sensor 4 Float 5 Pulley part 6 Hoisting spring 7 Bearing part 8 Detection sensor 9 Magnet coupling 10 Drop prevention tool 11 Connecting parts

Claims (8)

[Claims] 1. A liquid level sensor having a hoist spring disposed inside a float in a tank and a hoist pulley connected thereto. 2. The liquid level sensor according to claim 1, wherein the hoisting pulley, the hoisting spring, and a sensor for detecting the rotational position of the hoisting pulley and the hoisting spring are arranged coaxially with their central axes. 3. A liquid level sensor comprising a hoisting pulley and a speed-increasing gear connected to a sensor for detecting a rotational position of the hoisting pulley. 4. A liquid level sensor, wherein a connecting part wound by the hoisting pulley and a float are connected by a magnet. 5. The liquid level sensor according to claim 1, wherein the float and the hoisting pulley are made of resin. 6. The liquid level sensor according to claim 1, wherein a contact portion between the winding pulley and the winding spring is a point contact slide. 7. The liquid level sensor according to claim 1, wherein the cross section of the float does not increase in a downward direction from an upper portion near a liquid surface. 8. The liquid level sensor according to claim 1, further comprising a stopper for preventing a connecting part between the hoisting pulley and the float from dropping off the hoisting pulley.