JPH0126488B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a flowmeter that electrically measures the flow rate of fluid.

[Conventional technology]

Conventionally, an area flowmeter is configured so that the fluid to be measured flows into the bottom of a glass tapered tube into which a float is inserted, and flows out from the top.
It is used and widely known.

The patent applicant for the present invention previously applied for patent application No. 56-16536.
No. (Japanese Unexamined Patent Publication No. 57-131017), the tube body is made of a non-magnetic material and the float is made of a magnetic material, and the float is wound sequentially from the bottom to the top on the floating part of the tube. A reactance coil measuring device for the coil, including a reactance coil, a reactance circuit including the coil, a circuit for supplying high frequency power to the reactance circuit, and a circuit for detecting the voltage or current of the reactance circuit. We proposed a flowmeter equipped with a circuit that displays or outputs a detection signal.

According to the above-mentioned flowmeter, the linear continuous change signal corresponding to the change in flow rate can be detected and displayed as a real-time flow rate signal or as a control signal with a simple configuration without moving parts, and it is also possible to prevent environmental pollution. The system is strong and can be easily applied in cases where flow rate control or detection and recording of flow rate changes is required.

[Problem that the invention seeks to solve]

According to the above-mentioned flowmeter, there is a problem in that it takes time and effort to wind a fine wire around the tube body to form a reactance coil and to repair the tube, and further improvements have been desired.

The present invention has been made in order to solve the above problems, and its purpose is to eliminate the trouble of winding fine wires around a tube body to form a reactance coil, and to provide a flexible sheet-like structure for the tube body. Another object of the present invention is to provide a flowmeter that can be easily manufactured, repaired, etc. by attaching a strip-shaped printed coil.

[Means for solving problems]

The object of the present invention is to provide a flowmeter in which a fluid to be measured flows in from the lower part of a tube into which a float is inserted, and flows out from the upper part, the tube being made of a non-magnetic material; The float is made of a magnetic material, and a reactance coil consisting of a spiral printed coil whose number of turns gradually increases or decreases upward is provided in the part of the tube corresponding to the floating of the float. This is achieved by the above-mentioned flowmeter characterized in that it is provided with a flow rate measurement circuit that detects and displays changes in current or voltage.

[Effect]

With the above configuration, when the float floats up and down in the tapered pipe depending on the magnitude of the flow rate, the reactance of the reactance coil changes, and the changes in the current and voltage of the reactance coil due to this change can be measured on a scale by actually measuring the flow rate in advance. I try to measure it with an ammeter and a voltmeter.

Further, in the present invention, since the reactance coil is a printed coil as described above, the structure can be simplified and no special management is required to maintain measurement accuracy.

〔Example〕

The details of the present invention will be explained below with reference to the drawings.

FIG. 1 is a front view showing an embodiment of an area type flowmeter according to the present invention, FIG. 2 is a partially cutaway side view of FIG. 1, and FIG. 3 is a perspective view of a float. Fourth
The figure is a sectional view taken along line A-A in Figure 1, Figure 5 is a reactance coil with a different winding method than that in Figure 1, Figure 6 is a flow rate measurement circuit diagram, and Figure 7 is the same as Figure 6. is a different flow measurement circuit diagram.

In Figures 1 and 2, 1 is a glass taper tube which is the main element constituting the area flowmeter, and the inner diameter of the glass taper tube 1 gradually increases upwards. It has a taper. 2 is an inlet provided at the bottom of the flowmeter for guiding the fluid to be measured into the glass taper tube 1, and 3 is an outlet provided at the top of the flowmeter. 4 is a float that floats up and down within the glass taper tube 1 depending on the flow rate.

As shown in FIG. 3, this float 4 has an upper end 4a made of non-metallic material such as ferrite, alnico, Fe-Cr-Co, Sm
- Cast compacts of magnet materials such as Co-based, Pt-Co-based, Pr-Co-based, Pr-Sm-Co-based, etc., magnets made by molding and sintering fine powder, or ferromagnetic materials usually called coil iron cores, such as sendust. is provided. Furthermore, float 4
In addition to the above structure, a Teflon material with a magnetic core, ceramic with a magnetic core, graphite with a magnetic core, synthetic resin coating with a magnetic core, etc. may be used, or the entire float 4 may be made of metal. Also, float 4
The shape of can also be spherical.

In FIGS. 1, 2, and 4, 5 is a printed circuit board attached to one side of the glass tapered tube 1 in the longitudinal direction, and as shown in FIG. On the contacting side, spiral flexible printed wiring stretched in the longitudinal direction is densely packed at the top and gradually becomes sparser as it goes downwards, and is applied with glue or the like. A reactance coil 6 is configured by wiring.

In Fig. 1, 7 is a flow rate measuring device, and the flow rate measuring device 7 converts the float 4 vertically floating due to the flow rate and the accompanying change in the reactance of the reactance coil 6 into a current change or a voltage change. This is used to measure the flow rate. Incidentally, the change in reactance can be further increased by stacking two identical reactance coils 6 with an insulating adhesive or pasting them at different positions and connecting both coils in series.

FIG. 5 is an explanatory diagram showing a reactance coil wound in a different manner from that shown in FIG. 1. In FIG. 8, a plurality of spiral reactance coils 9 are printed and wired in series so that the number of turns gradually becomes sparse from dense to sparse from the top to the bottom in the longitudinal direction.

FIG. 6 is a diagram showing a flow rate measurement circuit. In FIG. 6, 10 is a high frequency oscillator, 11 is a reactance coil attached to the glass taper tube 1 and whose reactance changes, 12 is an impedance coil, and 13 is a diagram showing a flow rate measurement circuit. , 14 are resistors, respectively. 15
is a flow rate indicator that measures the flow rate in advance using an ammeter.

These circuit elements are connected as shown in FIG. 6 to form a Maxwell Bridge circuit.

In this circuit, when the reactance of the reactance coil 11 changes by δL, a current proportional to δL flows between B and C, and when the float 4 floats vertically within the glass taper tube 1, the reactance of the reactance coil 11 changes. However, as the float 4 floats upward, the reactance gradually increases, so the flow rate when the float 4 is stationary at a certain height inside the glass taper tube 1 is determined by the scale of the flow rate indicator 15. You can find out by reading.

FIG. 7 is a diagram showing a flow rate measuring circuit different from that in FIG. 6, in which 16 is a high frequency oscillator;
7 is a non-inductive resistor, 18 is a reactance coil attached to the glass tapered tube 1, 19 is its resistance, 20 is a capacitor that resonates with the reactance coil 18, and 21 is a capacitor that is actually measured with a voltmeter in advance. This is a flow rate indicator that measures the flow rate.

Therefore, in this circuit, the resistance of the non-inductive resistor 17
Since R ₀ is extremely smaller than the resistance R of the resistance component 19, and R ₀ <<R, a minute high frequency voltage E ₀ is generated across the non-inductive resistor 17, and this voltage is supplied to the LC tuning circuit.

The capacitance of the capacitor 20 is determined so that it resonates with the reactance coil 18 when the float 4 is located at the top of the glass taper tube 1. At the time of resonance, the terminal voltage E of the capacitor 20 is determined by I ₀ as the resonant current, C The following formula is obtained, where is the capacitance of the capacitor 20.

E=I ₀ /ωC=R ₀ /ωCR As the reactance of the reactance coil 18 becomes smaller than the value at resonance, the current flowing through the LC tuning circuit gradually decreases and the capacitor 20
terminal voltage becomes low. Therefore, depending on the vertical position of the float 4, the reactance coil 18
The reactance changes, and this change appears as a change in the terminal voltage of the capacitor 20, so the flow rate can be measured by the flow rate indicator 21 whose pointer swings at this voltage.

〔Effect of the invention〕

Since the present invention is constructed as described above, according to the present invention, the trouble of winding a fine wire around a tube body to form a reactance coil is omitted, and a flexible sheet-shaped or strip-shaped printed coil is attached to the tube body. It is possible to provide a flowmeter that can be attached and easily manufactured, repaired, etc., has a simple structure, and does not require special management to maintain measurement accuracy.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and for example, the glass taper tube 1 may be provided with a scale for visual recognition on the other side while displaying the detected flow rate or obtaining an output electric signal. In the first and second embodiments, the printed circuit boards 5 and 8 having the coils 6 and 9, respectively, may be in the form of transparent or translucent flexible sheets, or in the form of strips. In addition, the sheet-like printed circuit board is not limited to the side surface of the glass taper tube 1, and may be attached or set in a state where it is wound once, etc. In addition, a reactance coil, a float, The configuration of the measurement circuit and its elements can be freely modified within the scope of the purpose of the present invention, and the present invention encompasses all of these.

[Brief explanation of drawings]

FIG. 1 is a front view showing an embodiment of an area type flowmeter according to the present invention, FIG. 2 is a partially cutaway side view of FIG. 1, and FIG. 3 is a perspective view of a float. Fourth
The figure is a sectional view taken along line A-A in Figure 1, Figure 5 is a reactance coil with a different winding method than that in Figure 1, Figure 6 is a flow rate measurement circuit diagram, and Figure 7 is the same as Figure 6. is a different flow measurement circuit diagram. 1...Glass taper tube, 4...Float, 5,
8... Printed circuit board, 6, 9... Reactance coil, 7... Flow rate measuring device, 11, 18... Reactance coil.

Claims (1)

[Claims] 1. In a flowmeter configured such that a fluid to be measured flows in from the lower part of a tapered pipe body into which a float is inserted and flows out from the upper part, the pipe body is made of a non-magnetic material or , the float is made of a magnetic material, a reactance coil consisting of a spiral printed coil whose number of turns gradually increases or decreases in the upward direction is provided in the part of the tube corresponding to the floating of the float; The above-mentioned flowmeter is further equipped with a flow rate measurement circuit that detects and displays the current change or voltage change.