JPH064640Y2 - Radio wave shield room shield structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a shield structure of a radio wave shielded room that houses a magnet of a nuclear magnetic resonance apparatus (hereinafter referred to as an MRI apparatus).

[Conventional technology]

The MRI apparatus utilizes a fact that a raw paper nucleus placed in a uniform magnetic field causes nuclear magnetic resonance at a frequency proportional to the intensity of the uniform magnetic field to generate a tomographic image of a human body by computer calculation, and to generate a tomographic image of a human body. It is a medical diagnostic device for diagnosing abnormalities in the body. Compared to X-ray CT used for the same purpose, there is no radiation exposure, and internal tomographic images can be easily obtained through the bone like the head.
In recent years, many hospitals have installed this MRI apparatus because of the advantages such as the above.

The simple principle of the MRI apparatus is that a radio wave having a frequency matching the magnetic resonance frequency of hydrogen nuclei contained in the human body is irradiated by a transmission coil, and a free induction signal (abbreviated to FIS for short) generated by the atomic nuclei in the human body that resonates with this radio wave. ) Is received by the receiving coil repeatedly according to a predetermined system,
The received signal is processed to create image data, which are combined to create one image.

The nuclear magnetic resonance frequency of commercially available MRI apparatuses depends on the strength of the uniform magnetic field, but is a high frequency of several MHz to several tens of MHz, and this frequency is also in the radio frequency range. The radio waves are full, M
Since it becomes noise with respect to the reception signal of the RI apparatus, it is essential to block this noise in order to increase the SN ratio of the reception signal and obtain a clear tomographic image.

The most effective way to block such radio noise in the radio frequency range is to install the MRI device in a sealed container of a metal conductor.
A sufficient shielding effect can be obtained by covering the room in which the MRI apparatus is installed with the following copper foil.

Since such a thin copper foil is easy to cut, it is used by being attached to the wall material with an adhesive, and at the connection portion of the wall, the copper foils are electrically connected by soldering. The reason why copper material is suitable as a radio wave shield material is that it can be easily connected by soldering and has the advantage of aluminum.
Aluminum foil, which is used in a wider range than copper foil in other applications, is not used as a radio wave shielding material because it is difficult to solder.

[Problems to be solved by the device]

When making a radio wave shielded room in which a wall material with copper foil attached is attached to a steel frame and an MRI device is installed, the copper foil connection parts such as walls, floors, floors, and walls should be soldered as described above. Although they are electrically connected, if the room is deformed and displaced due to an earthquake or ground subsidence, cracks may occur in the soldered part or the copper foil itself. When such a crack is generated, the radio wave enters from the crack portion, the function of blocking the radio wave is deteriorated, the SN ratio of the reception signal of the MRI apparatus is deteriorated, the image quality is deteriorated, and it becomes unusable. The problem arises.

If a structure called a slab structure that supports the floor integrally with the wall with a steel frame is adopted, the gap between the wall and the floor is so small that it can be absorbed by the elongation of the copper foil, so the cracks described above occur. Although no problem occurs, this slab structure has a drawback that it is expensive because the weight applied to the floor is entirely borne by the columns. Since the room where the MRI device is installed is often installed in the basement where the floor is below the floor in order to suppress the effect of leakage flux as much as possible, it is called an earth floor structure instead of such a slab structure. It is economical to use a structure in which the weight of (1) is transmitted through the floor material and is borne on the ground, and a room where many MRI apparatuses are installed often uses this soil structure. Therefore, as described above, there is an unavoidable problem that the function of the radio wave shield is deteriorated due to cracks in the copper foil as a radio wave shield material and its connection portion due to an earthquake or ground subsidence.

It is an object of the present invention to provide a shield structure for a radio wave shielded room in which a copper foil as a radio wave shield material for a room in which an MRI apparatus adopting a dirt structure is installed does not crack even when an earthquake or ground subsidence occurs.

[Means for Solving the Problems]

In order to solve the above problems, according to the present invention, a wall material having a copper foil attached thereto, and a flooring provided with a copper foil below, of the copper foil attached to the wall material and the flooring material In a shield structure of a radio wave shielded room in which a copper foil laid below is connected, a wavy fold is formed at a connection portion between the copper foil to which the wall material is pasted and the copper foil laid below the floor material. A curved part shall be provided.

[Action]

In the structure of the present invention, a wavy fold is formed at the connection between the copper foil attached to the wall material forming the wall of the radio wave shielded room and the copper foil laid on the lower surface of the floor material at the connection portion between the wall and the copper foil. By providing the part, when the position of the wall and the floor are displaced due to an earthquake or ground subsidence, this wavy bent portion easily absorbs the displacement, and thus the copper foil and the soldered part are cracked. There is no.

〔Example〕

The present invention will be described below based on embodiments. FIG. 1 is an enlarged sectional view of an essential part of a connecting portion between a wall and a floor of a radio wave shielded room showing an embodiment of the present invention. In the figure, the floor of the radio wave shielded room 100 is laid with a copper foil 22 on a crushed stone 33 having a flat surface, and a floor material 3 made of concrete on the copper foil 22.
2 is provided and a floor finishing material 31 is laid on it, and a load such as a device installed on the floor is supported by the ground through the floor material 32 and the crushed stone 33.

The wall of the radio wave shield room 100 is a pillar 42 that supports the entire building.
It is composed of the wall base 11 attached to the beam 41 attached to and the wall finishing material provided inside the radio wave shield room, and the copper foil 21 is attached to the surface of the wall base 11 with an adhesive.

The pillar 42 is attached by an anchor bolt 51 driven into a foundation underground beam 52 provided on the crushed stone 53.
An outer wall material 43 is attached to the outside of the pillar 42 to adjust the appearance of the building. These configurations are similar to those of the conventional art.

The copper foils 21 and 22 constitute a radio wave shield of the radio wave shielded room, and the copper foils 21 and 22 are soldered and connected at the connection portion, and the bent portion 23 is provided at this portion.

FIG. 2 is an enlarged cross-sectional view of the bent portion 23 and its surroundings. In this figure, the soldering portion 2 of the copper foils 21 and 22
Wall foundation 11 and floor material 33 or foundation underground beam 52 near 4
The bent portion 23 is provided by utilizing the gap between the bent portion 23 and the. This bent portion is formed by bending the tip of the copper foil 22 into a plurality of wavy patterns as shown in the drawing.
Since the thickness is 0.1 mm or less, the bending process is easy.

As shown in FIG. 1, since the floor material 32 and the pillars 42 are supported by different foundations, if the ground surface is partially displaced due to an earthquake or ground subsidence, the floor material 32
The ground supporting the pillar and the ground below the foundation underground girder 52 supporting the pillar 42 may be displaced differently. Since the wall foundation 11 is supported by the columns 42 via the beams 41, the copper foil 22
The floor material 32 laid on the lower surface and the wall base 11 to which the copper foil 21 is attached are displaced differently, but since the bent portion 23 is provided at the connecting portion between the copper foils 21 and 22. The bending portion 23 does not expand or contract due to such different displacements, and an excessive tensile force does not act on the copper foils 21 and 22 or the soldering portion 24 to cause a crack. Therefore, even if the floor and the wall undergo different displacements due to the above-mentioned earthquake or ground subsidence, the copper foils 21, 22
Since there is no fear that the function as a radio wave shield will be deteriorated, a highly reliable radio wave shield room can be constructed by applying this invention.

Although FIG. 1 and FIG. 2 show a plurality of corrugated portions of the bent portion 23, when the height of the wave in the vertical direction can be increased, the number of waves may be one. If the height of the wave cannot be increased, the number of waves is increased to secure the amount of displacement absorbed by the bent portion 23. Although the shape shown in the drawing is bent at an acute angle, it may be bent in an arc shape to form one wave into an Ω shape.

[Effect of device]

As described above, this invention has a corrugated connection between the wall and the copper foil connecting the floor with the copper foil attached to the wall material forming the wall of the radio wave shielded room and the copper foil laid on the bottom surface of the floor material. By providing a bent portion, when the vertical position of the wall and floor shifts due to an earthquake or ground subsidence, this wavy bent portion easily absorbs, so that cracks may occur in the copper foil and the soldered portion. There is no. Therefore, since the function of the radio wave shield of the copper foil is not deteriorated, a highly reliable radio wave shield room can be provided, and the image quality of the MRI apparatus can be maintained for a long time without adopting an expensive slab structure. It is possible to provide a highly reliable medical diagnostic device that can be maintained for a long time.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view of an essential part showing an embodiment of the present invention, and FIG.
The figure is an enlarged cross-sectional view of an essential part in which the essential part of FIG. 1 is further enlarged. 100 ... Electromagnetic wave shield room, 11 ... Wall base material (wall material), 21, 22 ... Copper foil, 32 ... Floor material, 23 ... Bent portion, 24 ... Soldering portion.

Claims (1)

[Scope of utility model registration request] 1. A wall material having a copper foil attached thereto, and a flooring material provided with a copper foil underneath, wherein the copper foil attached to the wall material and the copper foil provided below the flooring material are In a shield structure of a connected radio wave shielded room, a wavy bent portion is provided at a connection portion between a copper foil attached to the wall material and a copper foil laid under the floor material. Radio wave shield The shield structure of the room.