JPH03189522A - Float type liquid level measuring instrument - Google Patents

Abstract

PURPOSE:To supply necessary electric power from outside by providing a solid- core coil in a float guide pipe and also providing an air-core coil which is concentric with the flow guide pipe in a float main body. CONSTITUTION:The solid-core coil 5 provided in the float guide pipe 2 is supplied with the AC current from an AC power source 6 to produce an alternating magnetic field in the lengthwise direction of a pipe 2. An AC electromotive voltage is induced by the air-core coil 8 concentric with the pipe 2 with the alternating magnetic field and an AC current flows to a DC power circuit 9. This AC current is converted by an AC-DC converting circuit, etc., into a DC current, which is supplied to an energy storage circuit 11 and a control circuit 10. Further, an amplifier 12 amplifies the DC current supplied from the circuit 11 with the control signal from the circuit 10 to drive a vibrator 13. Then the vibration energy of a vibrator 13 is propagated to the outer peripheral wall surface 2 of the pipe through a contactor 7 and a sound wave by resonance is generated in the pipe 2 with its vibrating wave and measured by a measuring circuit 16 through a sound wave sensor 14 and an amplifier 15.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a float type that outputs an electric signal suitable for measuring the level of liquid stored in a tank such as an oil storage tank. This relates to a liquid level measuring device.

[Prior Art] Conventionally, a liquid level measuring device can not only read the relative position of a float placed on the liquid surface with a liquid level gauge, but also read the rotation angle of the exit axis of the liquid level gauge as a code. It also converts it into a signal and transmits it to the receiving side.

In this way, with conventional liquid level measuring devices, the float body is designed to move freely up and down in the tank according to the liquid level, so it was difficult to place an electric device on the float body. .

[Problem to be Solved by the Invention J] As mentioned above, the problem is that the float body cannot be supplied with power from the outside due to constraints on its horizontal machine, and as a result, electrical devices cannot be placed on the float body. was there.

Therefore, in the present invention, by supplying power to the float main body while maintaining electrical insulation, it is possible to place an electrical device on the float main body, and by using this mounted electrical device, the tank The liquid level inside the tank can be measured.

In order to achieve the above-mentioned object, the float type liquid level gauge l111 device of the present invention has a hollow body that is placed vertically in a tank storing liquid and whose bottom surface is closed. In addition to providing a body, a cored coil of the same length is provided inside this hollow elongated body, and furthermore, an air-core coil that is kited by this hollow elongated body and moves up and down, and is concentric with the hollow elongated body is provided inside. In addition to providing an AC power supply that supplies alternating current to the cored coil inside the hollow body, an electric device that utilizes the power generated by the air-core coil inside the float is installed to adjust the liquid level value. The structure is characterized in that the signal can be transmitted by the signal transmitting device installed inside the float so that the signal can be received by the signal receiving device installed in the upper part of the hollow body. be.

[Example] An example of the present invention will be described in detail below with reference to a specific example shown in the accompanying drawings.

1 and 2 are a sectional view and a general view of a float type liquid level measuring device showing an embodiment of the present invention.

In FIG. 2, a float kite pipe 2 is installed on the upper surface of a tank 1 with its upper end 2a fixedly suspended within the tank 1. The upper end 2a of this float guide pipe is open, and the lower end 2b is closed.

A hollow donut-shaped float 3 is fitted into the float guide pipe 2 so as to float on the surface of the liquid stored in the tank 1 and freely move up and down with the liquid level.

Next, in FIG. 1, a mandrel body 4 having the same length as the float guide pipe 2 and made of a magnetic material is inserted into the float guide pipe 2. Further, on the outer peripheral surface of this mandrel body 4, a conductive v
j5 is spirally wound to form a cored coil.

An alternating current power source 6 is connected to this conductive wire 5, so that an alternating current TTt current is supplied. Furthermore, a sonic sensor 1 is installed in the opening 2a of the float guide pipe 2.
4 is installed, the sound wave sensor 14 is connected to a signal amplifier 15, and the signal amplifier 15 is connected to a 51 measurement circuit 16.

Next, you will be guided by the float guide pipe 2 and be free - ] -
A tongue-shaped contact 7 is fixed to the upper part of the float 3 that moves up and down so as to come into contact with the outer peripheral surface of the float guide pipe 2 and not to hinder the movement of the float 3. In addition, an inner wall 3a of the float 3 adjacent to the float guide pipe 2
A conductive wire is wound on the same center as the mandrel 4 to form a coil 8 with uniform winding density. A DC power supply circuit 9 having an AC/DC conversion circuit and the like is connected to this coil 8, and this DC power supply circuit 9 is further connected to supply DC current to each of the control circuit IO and the energy storage circuit 11. This energy storage circuit 1
1 consists of an oscillation circuit, a rectification filter circuit, etc.
Furthermore, an amplifier 12 is connected. A vibrator 13 is connected to this amplifier 12, and it is also connected to receive a control signal output from a control circuit IO. The vibrator 13 is fixed near the contactor 7 on the upper wall surface of the float 3.

Next, the functional operation of this embodiment will be described in detail below.

The conductor Tr of the cored coil provided in the float guide pipe 2! , an alternating magnetic field is generated in the longitudinal direction of the float guide pipe 2 by an alternating current supplied to the line 5 from an alternating current power supply 6.

Due to this generated alternating magnetic field, an alternating electromotive force is induced in the coil 8 which is provided in the float 3 and is located concentrically with the float guide pipe 2. The electromotive voltage induced in the coil 8 causes an alternating current to flow in the direct current power supply circuit 9. This DC power supply circuit 9 converts the supplied AC current into DC current using an AC/DC conversion circuit, a stabilization circuit, etc., and supplies the DC current to the energy storage circuit 11 and the control circuit 10.

However, since the power supplied by the electromotive force induced in the coil 8 cannot sufficiently cover the energy required to directly drive the vibrator 13, the energy storage circuit 11 temporarily stores the power energy and the amplifier 12 The control signal is supplied to the control circuit 10 according to a control signal output from the control circuit 10. On the other hand, the control circuit 10 sends a control signal to the amplifier 12 for driving the vibrator 13 with a predetermined intermittent cycle. Based on the control signal received from the control circuit 10, the amplifier 12 amplifies the DC current supplied from the energy storage circuit 11 and drives the vibrator 13. The vibration energy of the vibrator 13 causes the upper wall surface of the float 3 to which the vibrator 13 is fixed to resonate. Furthermore, the contactor 7 fixed to the upper part of the float 3 is caused to resonate by the vibration of the earthen wall surface of the float 3, and the vibration is further propagated to the outer circumferential wall surface 2c of the float guide pipe 2 with which this contactor 7 is in contact. It turns out. Furthermore, due to this propagated vibration wave, a sound wave is generated inside the float guide pipe 2 due to resonance.
Next, is the generated sound wave the float guide pipe? We will explain in detail how the information is transmitted using the fiS3 diagram.

The sound waves generated on the wall surface 2c of the float kite vibe 2 air propagate through the gap within the float guide vibe 2 as bidirectional sound waves St and downward sound waves S2.

The downward sound wave S2 is reflected by the closed lower end 2b of the float guide pipe 2, and returns to the upper surface as a reflected sound wave S3. A sound wave sensor 14 located at the upper end 2a of this float guide pipe 2 detects these upward sound waves S1 and reflected sound waves S3. The sound wave sensor I4 sends a detection signal of the detected sound wave to the signal amplifier 15, which amplifies this detection signal and outputs it to the measurement circuit 16 as a detection signal. Here, when the sound wave sensor 14 and the amplifier 15 detect the upward sound wave S, they output a detection signal t1, and the reflected sound wave S
3 is detected, the detection signal (assuming that 2 is being outputted), the Atll11 circuit 16 outputs this detection signal tl+t
7. Based on this, the delay time Δt from the first input detection signal t1 to the next input detection signal t2 is calculated M11, and the next calculation is also performed.
■? Here, as shown in FIG. 3, the float guide pipe 2
From the bottom of the pipe to the outer peripheral wall surface 2C which is the source of sound waves
The height from the liquid level to the outer wall surface 2C is the length Ll, the total length of the float kite vibe 2 is the length 2, and the height from the liquid level to the outer wall surface 2C is the length L.
a. Let the distance between the stable surface of the tank l and the lower end 2b of the float guide pipe 2 be a length La, and let the sound wave propagation speed inside the float kite pipe 2 be a speed ν.

Furthermore, since the actual liquid level exists below the length Ll by length 4, the height of the liquid level Lo=L+-1, a+I, 3ν = -Δ t-L4+L3 φ ■Finally, the measurement circuit 16 is the liquid level height Lo calculated by formula
is sent to a display circuit or remote control circuit (not shown).

This makes it possible to supply necessary power to the float 3 provided in the tank 1 while maintaining electrical insulation, and it becomes possible to store an electric circuit inside the float 3 body.

In the above embodiment, the liquid level was measured indirectly using the time difference when sound waves propagate through the gap between the float guide pipes 2, but an ultrasonic emitting device and a sound receiving device were installed on the bottom of the float 3. The liquid level may be measured by directly measuring the straight line distance from the float 3 to the bottom of the tank l.Also, although the float guide pipe 2 is cylindrical,
A vibrator with a cross section of another shape may be used, and the shape of the float 3 is not limited to the donut shape.Furthermore, the float guide pipe 2 is installed in the tank by hanging from the top surface of the tank l. However, it is also possible to adopt a strut system that connects the top and bottom surfaces of the tank l.

[Effects of the Invention] As explained below, according to the present invention, a cored coil having the same length as the pipe is provided in the float kite vibe, and
By installing an air-core coil concentric with the float guide pipe inside the float body that is kited by this float guide pipe, it is possible to supply the necessary power from the outside to the float moving up and down one mountain without contact. It has become possible to mount various electrical devices on the float body, which was previously difficult to do.

[Brief explanation of drawings]

FIG. 1 is an external view of a float-type liquid level measuring device showing one embodiment of the present invention, and FIGS. 2 and 3 are functional explanatory diagrams thereof. In the diagram, l... Tank 2... Float guide pipe 30 flow) 4- Mandrel body 5... Conductive wire 6... AC power supply 7... Contactor 8... Air core coil 9... DC power supply circuit 10... Control Circuit 110 Energy storage circuit 12... Amplifier 13... Vibrator 14... Sound wave sensor 15... Signal amplifier 16... Measurement circuit

Claims (1)

[Claims] A hollow long body with a closed bottom is installed vertically in a tank storing liquid, and a cored coil of the same length is installed inside this long hollow body, and the device moves up and down guided by this long hollow body. Moreover, a float having an air-core coil concentric with the hollow body is provided, an AC power source is provided to supply alternating current to the cored coil in the hollow body, and electric power is generated from the air-core coil in the float. The liquid level value is measured by installing an electrical device inside the float that utilizes this, and the signal is transmitted using a signal transmitting device installed inside the float so that the signal can be received by the signal receiving device installed on the upper part of the hollow body. A float type liquid level measuring device that is characterized by being able to