JP2001056363A - Detector and detecting apparatus for residual magnetism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a detector and a detecting apparatus, for residual magnetism, in which the residual magnetism generated on the surface of a building structure can be detected simply and in which its distribution state can be displayed quickly. SOLUTION: In this residual-magnetism detector 1, a concentric detecting coil 2 is provided, and an expansion and contraction body 3 which supports the coil and which moves the detecting coil 2 to the axial direction is provided. The expansion and contraction body 3 is connected to the detecting coil. Residual magnetism 7 is expressed as an induce voltage. The polarity and the intensity of the residual magnetism are detected by the induced voltage which is induced in the detecting coil 2. In addition, this residual-magnetism detecting apparatus in which a plurality of concentric detecting coils 2 are arranged in a matrix shape is constituted in such a way that the residual magnetism of a building structure plane 4 is expressed as the distribution state of an induced voltage in a matrix shape. The induced voltage which is distributed and displayed in a matrix shape is displayed or recorded by a storage device, and the distribution state of the residual magnetism can be confirmed visually.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a remanence detector and a remanence detector for detecting remanence of a ferromagnetic material, particularly remanence generated on a plane of a building structure.

[0002]

2. Description of the Related Art In recent years, with the progress of microelectronics, various electronic devices such as computers have been introduced into working and living spaces. Although the electronic device has its own magnetic proof strength, when the magnetic environment exceeds the magnetic proof strength of the electronic device, a fault occurrence area is formed. In particular, under recent circumstances where the magnetic strength of electronic devices has become excessively sensitive due to the improvement in the performance of electronic devices, the occurrence of various magnetic disturbances that have not been considered a problem has been reported and has become a social problem. I have. The failure occurrence event is C
RT fluctuations and color shifts, image defects and image distortions of medical equipment and electron microscopes, etc. In addition to leaked magnetic fields due to electric rooms and power lines in buildings, moving objects of iron such as elevators It has been pointed out that there are cases where magnetic disturbances are caused by changing the geomagnetism and cases where the building structure itself has residual magnetism.

[0003] The location of a leakage magnetic field generated from an electric room or a power line for electric power is specified, and a magnetic field is constantly generated. It is often dealt with specifically by moving objects or installing magnetic shields. On the other hand, it is difficult to identify the location of the residual magnetism of the building structure and it is often found after the building is completed. Or, it is not an appropriate solution in terms of the labor and cost for the work of providing a magnetic shield.

As a method of demagnetizing residual magnetism, generally,
There is an AC demagnetization method used for demagnetizing small electronic devices. This AC demagnetization method utilizes the hysteresis magnetic characteristics of ferromagnetic materials used in electronic equipment.The object to be demagnetized is placed in a demagnetizing coil that generates a magnetic field on a conveyor or the like. While passing, a predetermined current is supplied to the demagnetizing coil to apply an AC magnetic field to the object from the outside.
The strong alternating magnetic field applied to the object increases with time,
The magnetic flux density is gradually reduced while being alternately changed to minus, and the magnetic flux density of the ferromagnetic material is finally led to the zero point in the magnetic flux density B-magnetic field H curve to be demagnetized.

[0005] This method is desirable in terms of completely removing the magnetized magnetic flux density. However, since it is essentially assumed that an object is passed through a demagnetizing coil, it is necessary to use a method similar to a building structure. However, when the position where the residual magnetism is generated is on the floor, column, or wall surface of a building using a reinforcing bar or a steel frame, many problems to be solved have not been adopted.

The present inventors have already proposed an invention relating to "a method and a device for demagnetizing a building structure" to solve the above problems. As shown in FIG. 5, the present invention measures the polarity and strength of the residual magnetism by using a magnetic sensor 21 in the vicinity of the building where the electronic device is to be placed, as shown in FIG. ing. Demagnetizing coil 22
Is manufactured in a shape that can be carried to a place where remanent magnetism is generated, and is configured so as to cover a building structure requiring demagnetization as widely as possible.

When the residual magnetism is detected, the demagnetizing coil 22 is moved to the location to prepare for demagnetization. The demagnetizing coil is connected to a DC power supply 23 by a connection cable 24. The DC power supply 23 uses a capacitor, and stores a charge required for the capacitor by applying a DC voltage converted from a normal AC power supply wired on site via a rectifier.

The capacitor discharges the electric charge accumulated in the demagnetizing coil 22 connected in series by the connection cable 24 to form a desired damped oscillating current. The oscillating magnetic field 25 generated by the demagnetizing coil 22 due to the damped oscillating current attenuates with time in order to guide the remanence of the reinforcing bar to a zero point in the magnetic flux density B-magnetic field H curve, and the oscillating magnetic field 25 of the reinforcing bar 27 on the floor surface 26 It acts to demagnetize the residual magnetism 28. When a series of demagnetization operations are completed, the state of the remanence is measured by the magnetic sensor 21 again to confirm that the remanence that causes a failure to the electronic device is demagnetized.

As described above, the demagnetizing coil 22 can be arranged separately from the power supply and can be disposed independently on the surface of the building structure that generates the residual magnetism. The device is designed to be small and lightweight without the need for special controllers, making it easy to move around the work site as a whole, reducing labor and speeding up demagnetization operations, making demagnetization of residual magnetism efficient. Is becoming

[0010] The already proposed invention has a desired effect as a means for demagnetizing residual magnetism of a building structure which has been difficult to deal with conventionally. In particular, it is necessary to respond in a short time to the process, which is a situation unique to the construction site.
A power supply must be obtained from an outlet of about 30 A, and a large current cannot be expected. A wide range of movement is required, and the corresponding device needs to be reduced in weight. And so on.

On the other hand, the residual magnetism of a building structure is generated at floors and columns of a building using a reinforcing bar or a steel frame.
The surface of the wall, its manifestation is steel in concrete,
This is a result of integrating the residual magnetism magnetized in the unspecified portion of the reinforcing bar generally. In addition, regarding the residual magnetism of a building structure, many factors are unknown because the factor and the state of magnetization cannot be specified, and it is difficult to specify the direction and strength of the magnetic field generated on the plane of the building structure. In the situation.

At present, the detection of residual magnetism and the confirmation of demagnetization after the demagnetization process are performed using a television receiver brought to the work site, and a “coloring pattern” of the television receiver is displayed and displayed. The determination is made by comparing the degree of change in the “color composition”. However, in this method, it is necessary to mount the television receiver on the carriage and move it, so that there is a problem that a lot of man-hours are required and the degree of the judgment is varied. Also, in a measurement system using a magnetic sensor, it is necessary to arrange a magnetic sensor at each vertex of a rectangular parallelepiped to check whether the value exceeds a predetermined value (within geomagnetic field of ± 200 mG). I have.

However, to specify the direction and intensity of a magnetic field that is widely scattered on the plane of a building structure,
Since the efficiency of demagnetization work can be greatly improved, there is a strong demand for detecting residual magnetism by simple means. In particular, since we want to easily check the state of distribution of residual magnetism that appears on the plane of the building structure, the emergence of means for detecting the residual magnetism that occurs on the plane of the building structure is highly expected. By the way.

[0014]

SUMMARY OF THE INVENTION The present invention has been proposed in view of the above circumstances, and it is possible to easily detect the residual magnetism generated on the surface of a building structure, and to determine the distribution of the residual magnetism. Is provided, and a residual magnetic detector and a detection device capable of quickly displaying are displayed.

[0015]

SUMMARY OF THE INVENTION A residual magnetic detector according to the present invention is basically composed of a concentric detection coil, a telescopic member that supports the coil and moves the detection coil in the axial direction, and a residual voltage generated by the induced voltage of the coil. It consists of a magnetometer that displays magnetism, and by moving the detection coil in the axial direction with a telescopic body against the residual magnetism that appears on the plane of the building structure, the voltage induced in the detection coil is reduced. The polarity and intensity of the residual magnetism are detected by displaying on a magnetometer.

The apparatus for detecting residual magnetism of a building structure according to the present invention comprises a plurality of concentric detection coils arranged in a matrix, a telescopic member for simultaneously moving the coils in the axial direction, and an induced voltage of each coil. It consists of a magnetometer that displays the remanence of the object plane in a matrix, and the distribution of the remanence is visually confirmed by displaying the induced voltage displayed in a matrix and recording in a storage device. .

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Consisting of a concentric detection coil, a telescopic body that supports the coil and moves the detection coil in the axial direction, and a magnetometer that displays the residual magnetism by the induced voltage of the coil, it appears on the plane of the building structure. An induced voltage is generated in the detection coil by intersecting the residual magnetism and the detection coil moving in the axial direction by the elastic body, and the polarity and strength of the remanence are detected by displaying the induced voltage. Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a plan view (a) and a sectional view (b) showing an embodiment of a remanence magnetism detector according to the present invention. The detection coil 2 of the remanence magnetism detector 1 is wound in a rectangular shape as shown in the figure, and is mounted on an elastic air bag 3 or a bellows made of a non-magnetic material. The bellows on the side of the air bag 3 expand and contract due to the inflow and outflow of air from the outside. The expansion and contraction of the air bag is performed by moving the detection coil 2 in the axial direction so that the distance 5 between the surface 4 of the building structure and the detection coil 2 is increased.
Has the effect of changing

For the measurement of residual magnetism, the residual magnetism detector 1 is brought to the measurement site, and the air bag 3 is filled with air by an air pump or the like (not shown) until the air is full.
After the state of (b), the electronic device is set to the measured position where the electronic device is to be arranged. Next, the on-off valve of the air bag 3 is opened to release air from the air bag 3, and the detection coil 2 is lowered to the plane 4 of the building structure. As a result, in the place where the residual magnetism is generated, the magnetic field 8 and the detection coil 2 are crossed by the residual magnetism 7 magnetized in the reinforcing bar 6, and the polarity and strength of the residual magnetism can be detected.

The crossing between the magnetic field due to residual magnetism and the detection coil generates an induced voltage in the detection coil in a predetermined direction according to Fleming's right-hand rule. Therefore, when the direction and magnitude of the voltage generated in the detection coil are measured, the residual magnetism The polarity and strength of can be confirmed. That is, since the induced voltage is proportional to the product of the number of turns of the coil and the change in the magnetic field due to the residual magnetism, if the amount of air coming out of the air bag 3 is made uniform by an on-off valve or the like to keep the moving speed of the detection coil constant, As the magnetic field of the magnetism increases, the induced voltage increases, and the magnitude and polarity of the remanence can be specified.

As described above, the remanence magnetism detector according to the present invention is constructed simply by mounting a detection coil on an air bag and connecting a voltmeter to the detection coil as a magnetometer, so that it can be manufactured at low cost. can do. Also, in the detection work, the air bag filled with the detection coil is filled with air, and the detection is performed only by releasing the air, and the polarity and magnitude of the residual magnetism appearing on the surface of the building structure are detected. Can be detected, and the operation of detecting the residual magnetism can be performed quickly.

Further, in the apparatus for detecting residual magnetism of a building structure according to the present invention, a plurality of concentric detection coils are arranged in a matrix, and are simultaneously moved in the axial direction by a telescopic member. By connecting a magnetometer that displays the voltage in a matrix form, the distribution of the residual magnetism that appears on the plane of the building structure is configured to be displayed. The distribution of the residual magnetism can be visually confirmed by displaying the induced voltage and recording by the storage device. Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 2A is a plan view of a residual magnetism detecting device in which a plurality of residual magnetism detectors are arranged in a matrix, and FIG. 2B is a side view thereof. The remanence detection device 10 is intended to detect the distribution state of remanence by arranging a plurality of remanence detectors 1 in a matrix. In the present embodiment, as shown in FIG. , The detection coils of the remanent magnetism detector 1 are arranged on the horizontal axis in the form of six columns a to f, and the vertical axis is formed with eight rows 1 to 8,
A total of 48 detection coils of the residual magnetism detector 1 are arranged and configured. Each of the remanence magnetism detectors 1 arranged in the remanence magnetism detecting device 10 induces a voltage proportional to the polarity and strength of the magnetic field due to the remanence magnetism intersecting with the respective detection coils, and is arranged in a matrix. By outputting to each magnetometer, it is possible to detect the state of occurrence of residual magnetism in a predetermined area.

In order to accurately detect the distributed remanence, a plurality of remanence detectors 1 must be operated integrally. The residual magnetism detecting device 10 is normally
The air bag is in a compressed state as shown in the side view of FIG. For this purpose, at the time of measurement, the residual magnetism detection device 10 is set at the measurement site, and the detection coil 2 is raised to the same position away from the surface of the building structure by an operation such as injecting air into an air bag. Next, in a single detection operation, it is necessary to lower the detection coils of all the remanence magnetism detectors 1 at the same time.
The detection coils of the plurality of remanent magnetism detectors 1 arranged at 0 are associated with each other.

In this embodiment, the 48 residual magnetism detectors 1 have their detection coils uniformly arranged on the FRP plate placed on the air bag 11, and are supported by a single air bag. I have. Therefore, the lowering of the detection coil 2 required for detecting the residual magnetism is performed by injecting air into the air bladder 11 and arranging the air at the measurement site and then releasing air from the air bladder. For this purpose, the air bladder is provided with an open valve so that air can be released uniformly throughout,
All detection coils are adjusted to operate simultaneously.

In the above embodiment, all the residual magnetism detectors are arranged on one air bag and one FRP board in order to perform an integrated operation. It is not limited to. That is, the mutual association between the residual magnetic detectors is to lower the residual magnetic detectors all at once, and as long as this operation can be ensured, for example, the air bag is divided into a plurality of air chambers, and each divided It is also possible to choose to arrange the air chambers below the FRP plate in parallel at appropriate intervals, or to arrange them around only one FRP plate. Furthermore, even if the remanence magnetism detectors 1 of the embodiment shown in FIG. 1 in which the detection coil and the air bag are integrated are individually arranged to form a matrix state, the remanence magnetism detection device 10 is constituted. It is possible. In this case,
Various configurations are considered in the configuration of the open valve provided in each air bag for simultaneous operation.

3 and 4 show an embodiment in which the residual magnetism detecting device according to the present invention is applied to a building structure. FIG. 3 is a plan view, and FIG. 4 is a view taken along arrows 4-4 in FIG. FIG.
In FIG. 3, the residual magnetism detecting device 10 is applied to a corner of a living room surrounded by a wall 15. A plurality of rebars are placed on the floor of the living room,
It is assumed that three and fourteen appear. Magnetic field 12
Cannot identify the magnetized ferromagnetic material, but the magnetic flux from the N pole is generated on the surface of the building structure, and the residual magnetism detection arranged in the block b-1 of the remanence magnetism detecting device 10 The induced voltage is induced in the detection coil 2 of the detector 1 and the voltage is displayed on the same block of the magnetometer, so that the presence of the residual magnetism can be detected.

As shown in FIG. 4, the magnetic field 13 is a magnetic field from the remanent magnetism 7 that is magnetized in the reinforcing bar 6, and a magnetic flux from the N pole appears in the 2-d block and the 3-d block. The magnetic flux to the S pole is displayed in the block and the 3-e block. Accordingly, an induced voltage in the same direction is induced in the detection coil 2 of the remanent magnetism detector 1 arranged in the 2-d block and the 3-d block, but is arranged in the 2-e block and the 3-e block. An induced voltage in a direction different from that of the above-described block is induced in the detection coil 2 of the remanence magnetism detector 1.

The magnetic field 14 is an example of an integrated magnetic field from a number of ferromagnetic materials. In this case, the magnetic flux to the S pole appears in the 7-b, c, d blocks and the 8-b, c, d blocks,
The magnetic flux from the N pole is displayed in the 7-f block and the 8-f block. Therefore, 7-b, c, d blocks and 8-
An induced voltage in the same direction is induced in the detection coil 2 of the remanent magnetism detector 1 arranged in the blocks b, c and d.
The detection coils 2 of the remanent magnetism detector 1 arranged in the f-block and the 8-f block have 7-b, c, d blocks and 8-
An induced voltage in a direction different from that of the b, c, and d blocks is induced.

As described above, the apparatus for detecting residual magnetism in a building structure according to the present invention arranges a plurality of concentric detection coils in a matrix and moves them at the same time, so that the coils are induced in the magnetometer connected to each coil. By displaying the voltage in a matrix, it is configured to display the distribution of residual magnetism that appears on the plane of the building structure, so it is possible to display the induced voltage distributed by one operation of the elastic body, By the recording in the storage device, the distribution state of the residual magnetism can be visually checked collectively.

As described above, the present invention has been described in detail based on the embodiments. However, the residual magnetism detector and the residual magnetism detecting device according to the present invention are not limited to the above-described embodiments, and the present invention is not limited thereto. Naturally, various changes can be made without departing from the spirit of the present invention.

[0032]

The residual magnetism detector according to the present invention has a concentric detection coil supported by a telescopic member, and is moved in the axial direction as necessary to reduce an induced voltage generated in the detection coil due to crossover with the residual magnetism. Since the remanence is displayed as the remanence, the polarity and strength of the remanence appearing on the plane of the building structure can be easily detected at a reduced cost.

Further, in the apparatus for detecting residual magnetism of a building structure according to the present invention, a plurality of concentric detection coils are arranged in a matrix and supported by a telescopic member, and are moved in the axial direction as necessary, so that the residual magnetism is detected. Since the induced voltage generated in the detection coil due to the intersection with is displayed as remanent magnetism, or displayed in a matrix form by recording in the storage device,
This has the effect of visually confirming the state of distribution of residual magnetism that appears on the building structure plane.

[Brief description of the drawings]

FIG. 1 is a plan view and a cross-sectional view of a remanence detector according to the present invention.

FIG. 2 is a plan view and a side view of a remanence detection device according to the present invention.

FIG. 3 is an application diagram of a residual magnetism detection device according to the present invention.

FIG. 4 is a view taken in the direction of arrows 4-4 in FIG. 3;

Fig. 5 Demagnetization device for building structures

[Explanation of symbols]

1, residual magnetism detector, 2, detection coil, 3 air bag, 4 plane of building structure, 5 interval, 6 rebar,
7 residual magnetism, 8 magnetic field, 10 residual magnetism detection device, 11 air bag on which FRP board is mounted, 12-14
Magnetic field, 15 wall, 21 magnetic sensor, 22 demagnetizing coil, 23 DC power supply, 24 connection cable, 2
5 oscillating magnetic field, 26 floor, 27 rebar, 28 remanence

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shinichi Shibuya 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Corporation F-term (reference) 2G017 AA02 AA03 AA12 AA14 AB03 AC07 AD03 AD04 AD05 AD06 AD14

Claims (5)

[Claims] 1. A remanence detector comprising a concentric detection coil, a telescopic member supporting the coil and moving in the axial direction, and a magnetometer for displaying remanence by an induced voltage of the coil. 2. The residual magnetism detector according to claim 1, wherein the elastic body is a non-magnetic bellows. 3. A plurality of concentric detection coils arranged in a matrix, a telescopic member for simultaneously moving the coils in the axial direction, and magnetism for displaying the remanence of the building structure plane in a matrix by induced voltages of the respective coils. A residual magnetism detection device for building structures composed of a total. 4. The apparatus for detecting residual magnetism in a building structure according to claim 3, further comprising a storage device for recording the induced voltages distributed and displayed in a matrix. 5. The apparatus according to claim 3, wherein the elastic body is a non-magnetic bellows.