JPH0650309U - Degaussing device for building structure - Google Patents

Abstract

(57) [Summary] [Purpose] Degaussing the local magnetic part of a building structure with a simple device. [Structure] It is arranged in the local magnetic susceptor 2 of the building structure 1,
Coils 3 and 4 for forming magnetic flux in the magnetized portion 2 and a variable resistor 5 for gradually reducing the effective value of the alternating current flowing through the coils are provided.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a degaussing device for a building structure for degaussing a locally magnetized portion of the building structure.

[0002]

[Problems to be solved by conventional techniques and devices]

 During construction of a building, magnetic materials such as steel frames, reinforcing bars and other metals in building structures such as slabs, walls and columns are locally magnetized, and this magnetized portion may be discovered after the building is completed. As a result, the OA equipment malfunctions under the influence of the magnetic environment, color shift occurs in the computer's CRT display, and the information in it is corrupted, which reduces system reliability and reduces business operations. Have a significant impact. In order to solve this problem, it is possible to destroy and repair the magnetized part, but there is a problem with the strength of the building structure, and effective measures to solve this problem have not been taken so far. .

The present invention solves the above problem, and an object of the present invention is to provide a degaussing device capable of degaussing a local magnetized portion of a building structure with a simple device.

[0004]

[Means for Solving the Problems]

 To this end, the degaussing device for a building structure according to the present invention is arranged in a local magnetized portion 2 of the building structure, and has coils 3, 4, 8 for forming magnetic flux in the magnetized portion 2, and an alternating current flowing through the coils. And a variable resistor 5 for gradually reducing the effective value of. It should be noted that the numbers added to the above-mentioned configurations are for comparison with the drawings in order to facilitate understanding of the present invention, and the configurations of the present invention are not limited thereby.

[0005]

[Action]

 In the present invention, an alternating current is caused to flow through the coil disposed in the magnetized portion of the building structure to concentrate the magnetic flux in the magnetized portion, and the effective value of the alternating current is controlled so as to be gradually reduced, thereby locally Degauss the magnetized part that is magnetized to.

[0006]

【Example】

 Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a degaussing device for a building structure according to the present invention.

FIG. 1 shows an example of demagnetizing a slab or a wall of a building structure, in which coils 3 and 4 are arranged above and below so as to sandwich a magnetized portion 2 of the slab 1, and the coils 3 and 4 are variable such as sliders. It is connected to the AC power supply 6 via the resistor 5. Then, an alternating current is passed through the coils 3 and 4 to concentrate the magnetic flux in the magnetizing portion 2 as shown by an arrow in the figure, and the effective value of the alternating current is controlled to be gradually reduced to locally magnetize. Demagnetization of the magnetized portion 2 is performed.

2A and 2B show another embodiment of the present invention. FIG. 2A is a perspective view of a coil, and FIG. 2B is a perspective view of the coil attached to a column.

FIG. 2 shows an example of demagnetizing a pillar of a building structure. As shown in FIG. 2B, the coil 8 is arranged so that the coil 8 can be arranged around the pillar 7. As shown by the arrow in (A), it is a clamp type that can be separated and rotated on one side. The rest of the configuration and operation are similar to those of the embodiment shown in FIG.

Next, the principle of demagnetization in the present invention will be described with reference to the hysteresis curve of FIG.

FIG. 3A shows a state of magnetization of the magnetic body. When the magnetic body is placed in a space having a magnetic field in a certain direction and the strength H of the magnetic field is increased, the magnetic flux density B in the magnetic body becomes , Gradually magnetized along the curve a and saturated with Bm. After that, when the magnetic field strength H is decreased, the magnetic flux density B follows the path of the curve b instead of the path of the curve a, and the residual magnetism Br remains even if the magnetic field strength H is set to 0. Then, when the magnetic field strength H is increased in the opposite direction, the magnetic flux density reaches -Bm, after which the magnetic field strength H is reduced to 0 and H in the first direction. As is increased, the path shown by the curve c is followed.

FIG. 3B is a diagram showing how the magnetic body is demagnetized. As shown in FIG. 3A, even if a magnetic field is applied to a magnetized magnetic body in a direction opposite to the direction of magnetization, demagnetization cannot be performed. Therefore, the alternating current of the magnetic field is used to attenuate its effective value in time series to gradually remove the magnetization as shown by the curves d 1, e, f, and g.

[0013]

[Effect of device]

 As is apparent from the above description, according to the present invention, when a magnetic flux is formed in a local magnetic field of a building structure and a magnetic flux is formed in the magnetic field, the effective value of the alternating current flowing through the coil is gradually increased. Due to the configuration including the variable resistor for reducing the size, the local magnetized portion of the building structure can be demagnetized by a simple device.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a degaussing device for a building structure according to the present invention.

2 shows another embodiment of the present invention, FIG. 2 (A) is a perspective view of a coil, and FIG. 2 (B) is a perspective view in which the coil is attached to a column.

3A and 3B are views for explaining the principle of demagnetization in the present invention, FIG. 3A is a diagram showing a state of magnetization of a magnetic substance, and FIG. 3B is a diagram showing a state of demagnetization of a magnetic substance. Is.

[Explanation of symbols]

1 ... Slab, 2 ... Magnetic part, 3, 4, 8 ... Coil, 5 ... Variable resistor, 6 ... AC power supply 7 ... Pillar

Claims (1)

[Scope of utility model registration request] 1. A local magnetized portion of a building structure,
A degaussing device for a building structure, comprising: a variable resistor that gradually reduces an effective value of an alternating current flowing through the coil when a magnetic flux is formed in the magnetized portion.