JPH0382901A - Induction type conductor detector - Google Patents

Abstract

PURPOSE:To detect a conductor which is a body to be detected accurately without contact and to make it possible to detect the relative positions of the conductor and a detector by providing a comparing means for the output from at least two sets of detecting coil parts, and detecting the relative positions of the approaching conductor and the detecting coil part. CONSTITUTION:Detecting coil parts 13 and 13' are composed of a primary coil 11 or 11' and a secondary coil 12 or 12'. At least two or more sets of the detecting coil parts 13 and 13' are provided in a detecting part. The respective primary coils 11 and 11' of the detecting coil parts 13 and 13' are connected to an oscillator 31 in series, and a high frequency AC signal is supplied. The output signals from the secondary coils 12 and 12' of the detecting coil parts 13 and 13' are connected to two input terminals of a differential amplifier 33 through signal lead-out lines 32 and 32'. The data concerning to the position of a material to be measured are contained in the output signal of the differential amplifier 33. Namely, the approaching distance and the moving direction of the conductor are expressed by the magnitude and the polarity of the output signal.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a detector that non-contact detects the position of a conductor such as a metal, and particularly to a detector that uses electromagnetic inductive coupling between a primary coil and a secondary coil. This invention relates to an inductive conductor detector.

[Prior Art] 1- Conventionally, as a detector for non-contact detection of the liquid level of a liquid exhibiting conductivity, for example, as shown in the attached Figs. Two secondary coils (top and bottom)
Detection coil) 2.2 is vertically split, and while applying an AC signal to the primary coil 1, the conductor liquid level is detected using the signal induced in the two secondary coils 2.2 connected in series. things are known.

[Problems to be solved by the invention]However, in the non-contact detector according to the above-mentioned prior art,
Although it is possible to detect the proximity of a conductor without contact, there are some differences between the conductor and the detector, such as the moving direction of the conductor or the angle of inclination between the conductor and the detection coil. The problem was that it was not possible to detect the relative position of .

Therefore, in view of the problems in the prior art described above, the present invention is capable of accurately detecting a conductor in a non-contact manner, and also detects the relative position of the conductor, which is an object to be detected, and a detector. The purpose of the present invention is to propose an inductive conductor detector that can perform the following functions.

[Means for Solving the Problem] The object of the present invention is to provide a primary coil and a secondary coil close to each other, apply an alternating current to the primary coil, and apply an alternating current to the secondary coil. At least two detection coil sections configured to output signals are provided, and comparison means for comparing the output signals from the at least two sets of detection coil sections is provided, and based on the comparison result, the adjacent conductor and the above-mentioned An inductive conductor detector characterized by detecting the relative position with the detection coil part? It is achieved with great effort.

According to the inductive conductor detector described in Section 2, the detection coil section consisting of a primary coil and a secondary coil is connected to at least two coils.
A comparison means for comparing output signals from these two sets of detection coil units is used to compare and compare the output signals from these two sets of detection coil units, thereby detecting information regarding the relative position of the adjacent conductor and the -1 and two detection coil units. Therefore, not only the distance but also various kinds of useful information regarding the relative position of the conductor and the detector can be detected in a non-contact manner.

[Example] Hereinafter, regarding the example of the present invention, please refer to the attachment (=1).
jQ I'll explain while saying.

Actually, FIG. 1 shows a detection section of an inductive conductor detector which is a single-pointed embodiment of the present invention, and this detection section 10 consists of one primary coil 11 or II' and one primary coil 11 or II'. Detection coil section 1 consisting of secondary coil 12 or 12' etc.
3, +3 at least 2! J] and above. These primary and secondary coils 11.11"12.12" are formed by winding ordinary conductors, such as molten T4D.
: Metal? Nocturnal Suffering: Detect? When this is used, it is formed by wrapping a so-called sheathed cable 20 as shown in FIG. As shown in the figure, this sheathed cable 20 is constructed by filling the periphery of a central conductor 21 with a 1Ij494j material 22 such as magnesium dioxide, and covering the periphery with a sheath 23 made of stainless steel or the like.

In addition, - is the primary coil +1. ．． II' may be wound around -L of a coil bobbin 14.14' having the same shape as R, for example. Although it is preferable for this reason, it may be made of SUS material which has a relatively low frequency. However, in that case, it is desirable to reduce eddy current loss by inserting a slit etc. Also, the bobbin I4 and the core 15 may be integrated. Reference numeral 15.15 in the figure
' indicates an external core pushed into the center of the coil bobbin 14.

FIG. 2 shows a modification of the detection section of the inductive conductor detector shown in FIG.
A pair of detection coil portions I3.13' are provided at both ends of the approximately rUJ-shaped magnetic core 150 (=1 digit).

FIG. 4 shows the circuit arrangement u'+<M of the detection coil portions 13, 13' and the circuit device 30 electrically connected thereto, as described in 1 above. As is clear from this circuit diagram, the respective primary coils ILII' of the two detection coil sections 13, 13' are connected in series to the oscillator 31, thereby supplying a high frequency alternating current signal. However, when a sheathed cable is used for the coil as described in item 2, a relatively low-frequency AC signal is supplied because its impedance is high.

On the other hand, the output signals from the secondary coils +2.12' of the two detection coil sections 13 and +3' are sent to the two inputs 'Xi4' of the differential amplifier 33 via respective signal output lines 32.32''. The output signal of this differential amplifier 33 contains information about the position 1a of the detected object, as will be explained in detail below, and can be used, for example, with a control device for actuating an actuator. It is possible to input it to the indicator, display device rq (or alarm device Ftna).Also, in the above embodiment, the -1- output signal is expressed as an analog signal, but it can be input to the A/D It is also possible to convert it into a digital signal using a converter or the like.

Next, FIGS. 5 to 7 show a direction indicator using the above-mentioned inductive conductor detector, that is, a device for detecting the proximity distance of the conductor 50 and the direction of movement of the conductor 50 in a non-contact manner. . That is, when the conductor 50 approaches from the left side as shown by the arrow in FIG. 5(a), first the detection coil section 13' on the left side is The output of the detection coil section 13 on the right side decreases (indicated by the dashed line V11 in the figure), and then the output of the detection coil section 13 on the right side decreases (indicated by the dashed line V11 in the figure).
). At this time, the output of the differential amplifier 33 of the circuit device @30 shown in the circuit diagram of FIG. In addition, (2) generates an output signal with positive (+) polarity as the conductor 50 approaches.

On the other hand, when the conductor 50 approaches from the right side as shown by the arrow in FIG. 5(b), first the detection coil section 13 on the right side is The output V8 decreases, and then the output V of the left detection coil section 13' decreases. Therefore, as shown in FIGS. 6(b) and 7(b), the output V of the differential amplifier 19.1 unit 33 becomes an output whose polarity becomes negative (-) as the conductor 50 approaches. This will generate a signal.

As is clear from the above description, according to the inductive conductor detector of the present invention, the proximity distance of the conductor 50 and its moving direction are represented by the magnitude and polarity of the output V. Become.

Next, FIG. 8 shows a fluid meter that uses the inductive conductor detector of the present invention to detect the level position and direction of movement of the conductive fluid dripping into the container 60. ing. In this fluid meter, the two detection coil sections 13 and 13' are attached to the exterior of the container 60 one above the other. and,
According to this embodiment, based on the same principle as described above, the liquid level position of the conductive fluid 61 in the container 60 and its moving direction,
That is, it is possible to detect whether the liquid level is rising or falling.

FIG. 9 shows a so-called tilt sensor that detects the tilt angle θ of the conductor 70 using the inductive conductor detector according to the present invention. That is, as is clear from the operating principle explained above, when the inclination angle of the conductor 70 with respect to the two detection coil parts 13 and 13' is 0 degrees, Circuit device K shown in the circuit diagram
The output V of the differential amplifier 33 at t30 remains zero (V), but as the tilt angle θ increases, the output V increases, and furthermore, depending on the tilt direction, that is, upward to the right,
Alternatively, the polarity (+ or -) of the output V changes depending on the upward direction to the left.

Furthermore, in FIGS. 10 and 11(a) and (b), two sets of detection units 10 each consisting of two detection coil units 13 and 13' of the inductive conductor detector according to the present invention are used. A direction indicator is shown. In this embodiment, two detection coil sections 1 of each of these two sets of detection sections 10-1 and 10-2 are used.
3, 9-13' are further differentiated by adding codes -1 and -2. In this example, the first
As shown in the operation waveforms in Figures 1 (a) and (b), it is possible to detect the direction of movement of the conductor 80 not only in one direction, up and down or left and right, but in all directions - down, left and right. . That is, the output V-1 of the differential amplifier 33-1 outputs an output (solid waveform) corresponding to the vertical movement of the conductor 80, and the output V-2 of the differential amplifier 33-2 outputs an output corresponding to the vertical movement of the conductor 80. An output (broken line waveform) corresponding to movement in the left and right direction is output.

[Effects of the Invention] As is clear from the above description, according to the present invention, the proximity of a conductor can be accurately detected without contact, and furthermore, the proximity of the conductor, which is an object to be detected, and the detector can be detected accurately. It is also possible to easily detect various useful information regarding the relative position with respect to the conductor, and it becomes possible to provide an inductive conductor detector with extremely excellent performance in practical terms.

[Brief explanation of drawings]

=10- Fig. 1 is a partial cross-sectional perspective view illustrating the detailed structure of the detecting section of the inductive conductor detector according to the present invention, and Fig. 2 is a partial cross-sectional view showing another structure of the detecting section. FIG. 3 is a partially sectional perspective view showing the rules of the sheathed cable used to form the coil of the detection section, and FIG. 4 is a circuit diagram showing the circuit configuration of the inductive conductor detector. , FIG. 5(b) to FIG. 7(a), (b) are output operation waveforms illustrating the operation when detecting the proximity and moving direction of a conductor using the above-mentioned inductive conductor detector. Figure 8 is a conceptual diagram of the structure when detecting the level of conductive fluid and its moving direction using an inductive type electric body detector that will result in an unexploded lJ1, and Figure 9 shows the inclination angle of the conductor. 10 and 11 are structural conceptual diagrams of an omnidirectional movement detector which is another embodiment of the inductive conductor detector according to the present invention, and output operation waveforms for explaining its operation. 12 and 13 are (1"4 composition diagrams and circuit diagrams for explaining the prior art. 10...detection section +1.11'...primary film 1
11 2.12'... Secondary coil 13.13''... Detection coil section 14.14'... Coil bobbin 20...
・Sheathed cable 21...Conductor 22...Heat-resistant insulator 23...Sheath 15.15' 150
... f! 1 raw core 30...Circuit device 3I...
Oscillator 32.32"...Signal output line 33...Differential booster 50.70.80...Conductor 60...Container 61...Conductive fluid

Claims (1)

[Claims] A primary coil and a secondary coil are provided close to each other, and at least two detection coil sections are configured by applying an alternating current signal to the primary coil and outputting a signal induced to the secondary coil.
A comparison means for comparing output signals from the at least two sets of detection coil units is provided, and the relative position of the adjacent conductor and the detection coil unit is detected based on the comparison result. Inductive conductor detector.