JPH075029U - Liquid level measuring device - Google Patents

Abstract

(57) [Abstract] [Purpose] As a means to detect the liquid level in order to know the amount of liquid contained in the container, it is very simple and accurate, and it has excellent safety. To develop a liquid level measuring device called. A U-shaped detection conductor extending to the inner bottom is provided inside the container via an insulator provided on the lid of the container, and an oscillator electrically connected to the U-shaped detection conductor is provided outside. , The oscillation frequency obtained by oscillating an electromagnetic wave between the sensing conductors exposed above the liquid level is detected, that is, the oscillation frequency that continuously changes according to the exposed length of the sensing conductor To measure

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an apparatus for measuring the level (height) of a liquid surface which varies according to the amount of liquid in a container.

[0002]

[Prior art]

 Conventionally, various means have been used to detect the liquid level in the container. For example, a device with a ball tap attached to the valve to measure the liquid level, a container with a transparent pipe for checking the liquid level on the side of the container, a device to float the float on the liquid level to detect its height, and equidistantly inside the container. The one with a switch, the means for sending an electric current inside the container and detecting the current with a fixed terminal inside, the one with a pressure switch on the bottom of the container, etc. have been put to practical use.

However, each of these conventional techniques has the following drawbacks. (A) Poor indication accuracy due to wear of bearing part of ball tap ... (b) Difficult to confirm liquid level accurately ... (c) Difficult to confirm due to climate (rain, snow) ... (d) For liquid level confirmation It is difficult to see the position of the liquid or float in the pipe. … (E) It is dangerous if there is a switch inside the container or electricity flows. (F) Poor conduction due to dust adhering to the fixed terminals inside the container ...

[0004]

[Problems to be solved by the device]

 The present invention was made for the purpose of developing a liquid level measuring means that does not have the above-mentioned drawbacks, and it is possible to measure the liquid level height accurately, safely and simply. An object of the present invention is to provide a liquid level measuring device.

[0005]

[Means for Solving the Problems]

 As a result of various studies to achieve the above object, when a U-shaped detection conductor is immersed in a liquid and an oscillator oscillates an electromagnetic wave between these two branched detection conductors, an electromagnetic wave is generated between the detection conductors in the liquid. It was found that there is no oscillation and electromagnetic wave oscillation occurs only in the exposed part above the liquid level, and the oscillation frequency changes depending on the liquid level, and if this level is used to measure the liquid level, it is very excellent. They found that they could get results.

That is, according to the present invention, an insulator facing the inside and outside of the container is attached to the lid of the container, and a U-shaped detection conductor extending to the inner bottom of the container is provided on the inner side through the insulator. An oscillator electrically connected to the U-shaped detection conductor is provided on the outer side, and an electromagnetic wave is generated between the U-shaped detection conductor exposed above the liquid level in the container. The liquid level measuring device is characterized in that the height of the liquid level is measured by detecting an oscillating frequency.

The present invention will be described in detail with reference to the drawings. FIG. 1 is a front sectional view showing the outline of the device of the present invention. As shown in this figure, according to the present invention, there is a container (1), and a lid (2) of the container (1) is provided with a hole, and an insulator (3) is attached so as to fill the hole. There is. That is, the insulator (3) is fixed so as to face the inside and outside of the container (1).

A U-shaped detection conductor (4) is attached to a lower side of the insulator (3), that is, an inner side of the container (1), and a lower end of the U-shaped detection conductor (4) is a container ( It extends to the inner bottom of 1). The oscillator (5) is installed outside the insulator (3), that is, outside the container (1).

This oscillator (5) is composed of a coil, and is electrically connected to the lower U-shaped detection conductor (4) by a connecting wire (6). The oscillator (5) is also electrically connected to the control device (7).

[0010]

[Action]

 The present invention is configured as described above, and its operation will be described. For example, when the liquid surface (h) of the liquid (s) in the container (1) is at the position shown in FIG. 1, when a current is applied to the oscillator (5) to oscillate, the U-shaped detection conductor Electromagnetic wave oscillation occurs between the two conductors in (4), but electromagnetic wave oscillation occurs only in the exposed part (area a in the figure) above the liquid level (h) and below the liquid level (h). Electromagnetic wave oscillation does not occur in the liquid immersion part (region b in the figure).

Therefore, when the liquid level (h) is at the position shown in FIG. 1, an oscillation frequency peculiar to the position is obtained, and conversely, when this oscillation frequency is detected, the liquid level (h) is shown in FIG. It can be confirmed that it is in the position. Although not shown in FIG. 1, naturally, the container (1) is provided with an inlet and an outlet for the liquid (s) as necessary, and the position of the liquid level (h) is the liquid. It goes without saying that it changes depending on the use and supply of (s).

When the position of the liquid surface (h) changes, the exposed portion, which is the region a, also changes, and the oscillation frequency also changes accordingly. That is, the oscillation frequency changes continuously in proportion to the height of the liquid level (h) of the liquid (s) in the container (1).

In other words, when the U-shaped detection conductor (4) in the container (1) is used as a coil and a current is applied to the oscillator (5), a positive and negative sine waveform of the oscillation frequency is generated. Changes the magnetic field lines, and in this state magnetic field lines are created in the area a between the exposed conductors (4). The height of the liquid level (h) can be measured by detecting the amount of change, that is, the self-inductance. You can do it. When the container is a conductor, the container itself can be used as a U-shaped detection conductor.

As described above, according to the present invention, when the liquid level is known, the current is applied to the oscillator (5) and the oscillation frequency is detected. You can know it accurately. For example, this oscillation frequency can be converted into liquid level height using a device such as a digital counter and expressed as a numerical value for measurement. It should be noted that various additional devices such as an automatic valve opening / closing device for constantly maintaining the liquid level, an automatic opening / closing valve capable of freely adjusting the liquid level, or a device for notifying the liquid level is incorporated in the device of the present invention. Makes it even more convenient.

[0015]

【Example】

 A hole was made in the center of the lid of a cylindrical container having a diameter of 3 m and a depth of 3.5 m, and an insulator was attached so as to fill the hole. A U-shaped detection conductor having a length whose lower end contacts the inner bottom of the container was attached to the lower side of this insulator. On the other hand, an oscillator was provided outside the insulator to make electrical connection with the control device including the measuring instrument. Further, the oscillator and the U-shaped detection conductor were electrically connected by a conductive wire.

First, the oscillation frequency of the measuring instrument was adjusted to 3.5 MHz with no liquid in the container. Kerosene was poured into the container as a liquid, and the oscillation frequency data was taken every time the liquid level rose by 10 cm, and a graph as shown in Fig. 2 was obtained. The curve (r) in Fig. 2 is the measured value, and the frequency increases as the liquid volume increases. Although the target value line (t), which is a perfect proportional relationship, is slightly displaced, the oscillation frequency is It was confirmed that the height of the liquid surface can be detected by the measurement.

If a microcomputer or the like is installed in the control device so that the deviation from the target value straight line (t) can be corrected, it is possible to measure with a linear output, The liquid level can be detected at the output frequency in a completely proportional relationship.

[0018]

[Effect of device]

 The effect of the present invention is that the liquid level in the container can be accurately measured by simply turning on the switch of the oscillator installed outside the container.Therefore, the control device and other switches are installed indoors. It is possible to know the amount of liquid in an outdoor container, it is easy to see and handle, it is extremely simple, and it has excellent safety, and there is no conduction failure due to dust, etc. It is extremely useful.

[Brief description of drawings]

FIG. 1 is a front sectional view showing the outline of the device of the present invention.

FIG. 2 is a graph showing the relationship between the liquid level and the oscillation frequency in the embodiment of the present invention.

[Explanation of symbols]

 (1) Container (2) Lid (3) Insulator (4) U-shaped sensing conductor (5) Oscillator (6) Connecting wire (7) Controller (s) Liquid (h) Liquid level (r) Curve ( t) Target line

Claims (1)

[Scope of utility model registration request] 1. A container lid is provided with an insulator facing the inside and outside of the container, and a U-shaped detection conductor extending to the inner bottom of the container is provided on the inside via the insulator. Each of which is provided with an oscillator electrically connected to the U-shaped detection conductor, and the U which is exposed above the liquid level in the container.
A liquid level measuring device characterized in that the height of the liquid level is measured by detecting an oscillation frequency obtained by oscillating an electromagnetic wave between the character-shaped detection conductors.