JP3057563B2 - Receiving electromagnetic coil - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is mainly applied to the measurement of submarine land subsidence and the like, and is used in a receiving system of an information communication apparatus for facilitating information communication underground or underwater. It relates to an electromagnetic coil.

[0002]

2. Description of the Related Art Conventionally, when constructing artificial ground on the sea,
Landfill works are performed. In such landfill works, when the earth and sand falls into the sea, the submarine ground subsidence occurs due to the weight of the earth and sand itself. When measuring such subsidence of the seabed, a sensor output indicating a change in water pressure data due to subsidence is normally transmitted from a water pressure sensor installed on the seabed from underground or underwater to the sea surface using a cable.

However, in such a configuration, for example, the cable is cut when the amount of settlement of the seafloor ground exceeds the allowable range of the elongation of the cable, so that it cannot be applied when the amount of settlement is large.

[0004] In recent years, information communication devices have been developed that allow measurement data to be communicated wirelessly without using a cable, whereby measurement data can be transmitted using a low-frequency frequency with low attenuation as a carrier wave. I try to transmit.

FIG. 4 is a block diagram showing a basic configuration of such an existing information communication device. This information communication apparatus includes a transmission system device installed on the sea floor and a reception system device installed on the sea or on the ground.

[0006] In the transmission system, the oscillation output from the oscillation circuit 2 is amplitude-modulated as a modulated signal by the modulation circuit 4 based on the sensor output from the pressure sensor 1 converted into a communication electric signal by the conversion circuit 3. And outputs it as a modulation signal. This modulated signal is amplified by the amplifier circuit 5 and then transmitted to the transmission electromagnetic coil 6. The transmitting electromagnetic coil 6 generates a magnetic flux in accordance with the current value of the amplified modulation signal and sends it out. In this case, the modulation signal from the modulation circuit 4 by the oscillation output of the oscillation circuit 2 causes the amplitude change of the magnetic flux to change. It will be shown.

In the receiving system, the voltage induced by receiving the change in the amplitude of the magnetic flux from the transmitting electromagnetic coil 6 in the receiving electric coil 7 becomes an output proportional to the magnetic flux transmitted from the transmitting electromagnetic coil 6. After this is differentially amplified by the differential circuit 8 and then detected by the detection circuit 9, it is collected by the recorder 10.

Here, since the electric conductivity of seawater or earth and sand, which are propagation media for wireless communication, is extremely high, a carrier having a low frequency is usually used to reduce propagation loss. For example, the carrier frequency of the oscillation circuit 2 is 10 kHz.
If it is less than z, the wavelength is 30 k in comparison with the transmission distance of several km.
m, the signals around the receiving electromagnetic coil 7 installed on the sea or on the ground, which is the receiving position, are all magnetic field components due to magnetic flux, and no electric field component is generated as a signal component. As a result, the electric field component detected by the receiving electromagnetic coil 7 becomes an external noise component.

[0009]

In the case of the above-mentioned information communication apparatus for transmitting information communication by radio, transmission is performed using a low-frequency frequency with a small amount of attenuation as a carrier wave. If the length becomes longer, the ratio of the noise signal due to the electric field component from the outside to the signal of the magnetic field component received by the receiving electromagnetic coil increases, so that there is a disadvantage that long-distance signal transmission cannot be performed.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and its technical problem is that a noise signal due to an external electric field component can be sufficiently suppressed to enable long-distance signal transmission. An object of the present invention is to provide a receiving electromagnetic coil.

[0011]

According to the present invention, a magnetic flux generated by supplying a current to a transmitting electromagnetic coil is received, and an electric insulating region is provided around the outer periphery of the coil winding in the winding direction. And a receiving electromagnetic coil provided with an electric field shield for suppressing generation of a noise signal induced as a voltage by an external electric field component is obtained.

Further, according to the present invention, in the above-described receiving electromagnetic coil, the electric field shield is formed by spirally winding a non-magnetic metal band using a non-magnetic material around the coil winding. A receiving electromagnetic coil having an insulating material provided between the intersecting regions is obtained.

[0013]

In the receiving electromagnetic coil according to the present invention, by providing an electric field shield on the coil winding, the generation of a noise signal induced as a voltage by an external electric field component is suppressed. Transmission becomes possible.

[0014]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a perspective view of a local portion showing an external configuration of a receiving electromagnetic coil 20 according to an embodiment of the present invention.
As described with reference to FIG.
While receiving magnetic flux generated by supplying current to a transmission electromagnetic coil provided in a transmission system device installed in the ground or underwater, it is provided in a reception system device installed on the sea or on the ground. , The receiving electromagnetic coil 2 here
0, an electric field shield S for forming an electrically insulating region with respect to the outer periphery in the winding direction of the coil winding 21 to suppress the generation of a noise signal induced as a voltage by an external electric field component. Is provided.

The electric field shield S is formed so as to include a nonmagnetic metal strip 23 spirally wound around a first insulating member 22 provided outside the coil winding 21. Here, by providing the first insulating layer 22 between the coil winding 21 and the electric field shield S, the inductance of the coil and the resonance characteristics of the LC resonance circuit due to the capacitance connected in parallel to the coil are improved. .

FIG. 2 is a side sectional view of a local portion showing a detailed configuration of the electromagnetic coil 20 for reception. Referring to FIG. 2, the electric field shield S is further provided with a second insulating material 24 between the regions where the start and end of the non-magnetic metal strip 23 intersect. The second insulating material 24 is provided in order to prevent the non-magnetic metal strips 23 arranged on the left and right at the intersection of the non-magnetic metal strips 23 from being short-circuited and causing a short ring.

When such a receiving electromagnetic coil 20 is provided with a receiving system device and communicates with a transmitting system in an information communication device, a magnetic flux generated by supplying a current to the transmitting electromagnetic coil is generated. The electric field shield S provided on the receiving electromagnetic coil 20 when receiving by the receiving electromagnetic coil 20
To sufficiently suppress the generation of a noise signal induced as a voltage by an external electric field component, so that the ratio of the noise signal due to the external electric field component to the magnetic field component signal is remarkably reduced (the signal-to-noise ratio is improved). As a result, it is possible to perform long-distance transmission while increasing the signal reception distance.

FIG. 3 shows an equivalent circuit in the receiving electromagnetic coil 20 and the differential circuit. In this equivalent circuit, the receiving electromagnetic coil 20 is configured such that an LC resonance circuit in which a capacitor C is connected between both output sides of a coil L is covered with an electric field shield S. Electric field shield S
The LC resonance circuit covered by is connected to the differential circuit housed in the metal container 25 by the shield wire 26.
The differential circuit is configured by providing a resistor at a predetermined location on the input / output side of the differential amplifier, and one of the input sides is grounded to the metal container 25. The differential circuit is connected to a detection circuit arranged on the output side by a shield line 26.

That is, the receiving apparatus including such an equivalent circuit functions in the same manner as that described with reference to FIG. 4, but is functionally improved in the configuration of the receiving electromagnetic coil 20, and is therefore shown in FIG. The difference is that the generation of a noise signal induced as a voltage by an external electric field component can be sufficiently suppressed as compared with the reception electromagnetic coil 7. It has been applied to.

[0021]

As described above, according to the receiving electromagnetic coil of the present invention, the electric field shield for suppressing the generation of the noise signal induced as a voltage by the electric field component from the outside in the coil winding is provided. By providing this, it is possible to remarkably reduce the ratio of the noise signal due to the external electric field component to the signal of the magnetic field component (improve the signal-to-noise ratio) and to prevent the electric field shield itself from becoming a short ring. An insulating material is provided in the area where the electric field shield intersects to improve the detection efficiency of the magnetic field component. Therefore, this receiving electromagnetic coil is provided in the receiving system to communicate with the transmitting system in the information communication device. In such a case, it is possible to perform a long-distance transmission with high sensitivity after extending the reception distance of the signal.
Accordingly, for example, when the settlement of the seabed is measured by an information communication device, the measurement range can be extended to a deeper position than before, which is extremely useful industrially.

[Brief description of the drawings]

FIG. 1 is a perspective view of a local portion showing an external configuration of a receiving electromagnetic coil according to an embodiment of the present invention.

FIG. 2 is a side sectional view of a local portion showing a detailed configuration of a receiving electromagnetic coil shown in FIG. 1;

FIG. 3 shows an equivalent circuit in the receiving electromagnetic coil and the differential circuit shown in FIG. 1;

FIG. 4 is a block diagram showing a basic configuration of a conventional information communication device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 pressure sensor 2 oscillation circuit 3 conversion circuit 4 modulation circuit 5 amplification circuit 6 transmission electromagnetic coil 7, 20 reception electromagnetic coil 8 differential circuit 9 detection circuit 10 recorder 21 coil winding 22 first insulating material 23 non-magnetic Metal strip 24 Second insulating material 25 Metal container 26 Shield wire C Capacitor L Coil S Electric field shield

──────────────────────────────────────────────────続 き Continuation of front page (58) Field surveyed (Int. Cl. ⁷ , DB name) H01F 38/14 G01C 13/00 G01D 21/00 G08C 19/00

Claims (2)

(57) [Claims] 1. A magnetic flux generated by supplying a current to a transmission electromagnetic coil is received, and an electric insulating region is formed around the outer periphery of the coil winding in a winding direction to generate an electric field component from the outside. An electromagnetic coil for reception, comprising an electric field shield for suppressing generation of a noise signal induced as a voltage. 2. The electromagnetic coil for reception according to claim 1, wherein the electric field shield is formed by helically winding a non-magnetic metal band using a non-magnetic material around the coil winding. An electromagnetic coil for reception, wherein an insulating material is provided between intersecting regions.