JP4154690B2 - Magnetic shield room opening structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a structure of an opening portion such as an entrance / exit (door) and a cable introduction port provided in a magnetic shield room used in a biomagnetism measurement room, a semiconductor manufacturing facility room, and the like.
[0002]
[Prior art]
In the above magnetic shield room, a high permeability material such as a permalloy plate is overlapped with a non-magnetic plate such as aluminum or copper to create a shield wall, and there are multiple shield walls according to the size / shape of equipment and equipment accommodated inside. It joins and has a box shape or a cylindrical shape. The purpose of the magnetic shield room is to prevent external magnetism from entering the interior. Alternatively, it is intended to prevent internal magnetism from leaking to the outside. However, the shield wall of the magnetic shield room is provided with openings such as entrances and exits (doors) for entering and exiting people and objects and cable introduction ports for passing power lines and signal lines of equipment housed inside. There is a need. Magnetic shield performance must be ensured even in such an opening.
[0003]
FIG. 7 shows a first conventional structure for ensuring magnetic shielding performance in the opening (see Patent Document 1). When the sheets 21 to 24 are attached to both surfaces of the shield wall 11 and the door 12, an inner shield layer is constituted by the inner sheet 21 of the shield wall 11 and the inner sheet 23 of the door 12, and the outer sheet 22 of the shield wall 11 An outer shield layer is constituted by the sheet 24 on the outer side of the door 12. When the roller diaphragm handle 15 provided on the door 12 is turned, the roller 17 attached integrally with the handle 15 engages with the engagement groove 16 provided in the opening of the shield wall 11, and the shield wall 11 and the door 12 are mutually connected. It is strongly attracted. As a result, the degree of adhesion between the sheet 21 inside the shield wall 11 (upper side in the drawing) and the sheet 23 inside the door 12, the sheet 22 outside the shield wall 11 (lower side in the drawing), and the sheet 24 outside the door 12 This improves the degree of adhesion of the magnetic field and prevents magnetic leakage / intrusion at the opening.
[0004]
FIG. 8 shows a second conventional structure for ensuring magnetic shielding performance in the opening (see Patent Document 2). This figure is a longitudinal sectional view of a door portion that opens and closes the entrance / exit of the shield room. The walls 23 and 26 constituting the entrance / exit of the shield room are formed of stainless steel plates and project from the wall 27 of the shield room main body. The door 22 is configured by covering a frame formed of stainless steel, aluminum material, or the like with a stainless steel plate, and projecting walls 28 and 31 that fit into the entrance / exit of the shield room are formed on the periphery of the inner surface. Band-shaped shield members (finger contacts) 32, 33 formed of beryllium copper are disposed on the outer peripheral surfaces of the protruding walls 28, 31 and the upper part of the peripheral edge. When the door 22 is closed, the shield member 32 is pressed against the inner surfaces of the walls 23 and 26 due to its elasticity, and the shield member 33 is pressed against the end surface of the wall 23 to electromagnetically shield between the shield room body and the door 22. .
[0005]
[Patent Document 1]
Japanese Patent Laid-Open No. 3-233086 [Patent Document 2]
Japanese Patent Laid-Open No. 2-112581 [0006]
[Problems to be solved by the invention]
When installing a magnetic shield room, for example, a thin plate of high magnetic permeability permalloy (NiFe alloy) is used as a thin plate of magnetic material used to form the shield wall. This permalloy needs to be finally heat treated at 1000 ° C. in order to obtain magnetic properties after machining such as cutting and drilling to a predetermined dimension. In this case, distortion due to heat treatment occurs. The magnetic shield room is generally assembled by joining a plurality of steel plates in a box shape. The assembled magnetic shield room weighs several to a dozen tons, so usually the members are transported to the site and assembled there. For example, it is reasonable to prepare a plurality of shield walls constituting the magnetic shield room in advance and assemble and bond the shield walls on site. When the shield wall is assembled on site, it is inevitable that the position of the joint will be distorted due to accumulation of dimensional errors and installation errors of the shield wall itself.
[0007]
In the structure of the opening in FIG. 7, even if the flatness and parallelism of both surfaces of the shield wall 11 and the door 12 are insufficient, they are sufficiently attracted and pressed against each other by the roller-equipped handle 15 and are sufficiently in contact with each other. High degree of adhesion can be obtained. However, there is a problem in that if the flatness and the parallelism are insufficient and the roller handle with roller 15 is pressed strongly, excessive stress is applied to the sheets 21 to 24 and the magnetic characteristics are deteriorated. This phenomenon is particularly noticeable when the magnetic shield sheet is made of permalloy (NiFe alloy).
[0008]
In the structure of the opening shown in FIG. 7, in order to obtain sufficient adhesion between the shield wall 11 and the door 12 without applying excessive stress, the flatness and parallelism of both surfaces that are in pressure contact with each other are ensured with high accuracy. Must have been. However, when the magnetic shield sheet is made of permalloy, there is a problem that it is difficult to ensure flatness due to distortion caused by heat treatment. Further, since the shield wall 11 and the door 12 are assembled on site, there is a problem that it is difficult to ensure parallelism between the shield wall 11 and the door 12 with high accuracy.
[0009]
On the other hand, in the structure of the opening in FIG. 8, the shield members 32 and 33 are pressed against the inner surfaces and end surfaces of the walls 23 and 26 by their elasticity, and therefore the shield members 32 and 33 and the inner surfaces and end surfaces of the walls 23 and 26 Both can be pressed against each other without securing parallelism with high accuracy and without applying excessive stress. However, since the shield members 32 and 33 and the walls 23 and 26 are in point contact or line contact, there is a problem that the magnetic resistance when the magnetic flux passes through the shield member 32 and 33 and the walls 23 and 26 increases.
[0010]
The present invention was made to solve such conventional problems, and the object of the present invention is to ensure that the flatness and parallelism between the shield wall and the closing member that closes the opening are not secured with high accuracy. However, it is an object of the present invention to provide an opening closing structure capable of magnetically coupling the two without causing leakage or intrusion of magnetic flux.
SUMMARY OF THE INVENTION An object of the present invention is to provide an opening closing structure capable of magnetically coupling a shield wall and a closing member for closing the opening without applying magnetic flux leakage or intrusion without applying excessive stress. It is to be.
[0011]
[Means for Solving the Problems]
The magnetic ribbon having excellent flexibility is deformed freely according to the flatness and parallelism of the surface of the other shield material by receiving the pressing pressure, and adheres well to the other shield material. The present inventor has found that the above object can be achieved by using a magnetic ribbon having excellent flexibility as a joining member for magnetically joining a shielding material for a shielding wall and a shielding material for an opening closing member such as a door. The present invention has been reached.
[0012]
That is, the first invention of the present application includes a shield wall, a shield material provided on the shield wall, a closing member that closes the opening of the shield wall, a shield material provided on the closing member, and the opening. And a magnetic ribbon that contacts both the shield material on the shield wall side and the shield material on the closure member side when closed by the shield, wherein the magnetic ribbon is flexible to itself. And has one end facing the opening, and an elastic member is disposed on the back side opposite to the opening, and when the closing member is open, the opening faces the opening. The surface on one end side of the magnetic ribbon enters the opening, the other of the magnetic ribbon contacts the shield material on the shield wall side, and the back surface of the magnetic ribbon is pressed by the elastic member, When the closing member closes the opening The surface on one end side of the magnetic ribbon facing the opening is brought into close contact with the surface of the shield member on the side of the closing member against the pressing force of the elastic member, and closes the closing member. In the closed state, the one end side surface is pushed by the surface of the shielding member of the blocking member to be flush with the opening structure of the magnetic shield room.
[0013]
A second invention of the present application includes a shield wall, a magnetic ribbon provided on the shield wall, a closing member that closes the opening of the shield wall, a shield material provided on the closing member, and a closing member for the opening A closed structure of an opening where the magnetic ribbon on the shield wall side and the shield material on the closure member side are in contact with each other, the magnetic ribbon having its own flexibility, and one end thereof The elastic member is disposed on the back surface opposite to the opening, and in the state where the closing member is open, the one side of the magnetic ribbon facing the opening is arranged. The surface penetrates into the opening, the other of the magnetic ribbon contacts the shield wall side, the back of the magnetic ribbon is pressed by the elastic member, and the closing member closes the opening The surface of one end of the magnetic ribbon facing the opening is While pressed against the surface of the shielding material on the side of the blocking member against the pressing force of the member, the surface on the one end side of the shielding material of the blocking member is in close contact with the surface contact and the closing member is closed. It is the obstruction | occlusion structure of the opening part of the magnetic shield room characterized by being pushed by the surface and becoming flush | level .
[0014]
In the present invention, the magnetic ribbon is formed of an amorphous alloy material that is an Fe-based alloy having a high magnetic permeability, or an alloy material in which fine crystal grains having a grain size of 500 nm or less mainly composed of iron element occupy at least 50% of the structure. A magnetic material can be preferably used. Since this magnetic ribbon has the following characteristics, it is suitable as a joining member for a magnetic shield room.
(1) This magnetic ribbon is a material excellent in flexibility.
(2) Since this magnetic ribbon can efficiently collect magnetic flux in the space, it can be used as a magnetic material having a smaller thickness than a conventional magnetic shield.
(3) The obtained Fe-based alloy has sufficient hardness and is less susceptible to stress and strain than the NiFe alloy shielding material, and thus hardly causes the inverse magnetostriction effect.
[0015]
Since the magnetic ribbon described above can be closely attached to both wall members at the joint portion, leakage of magnetic flux can be reduced. This is due to the excellent flexibility of the alloy material. A thin magnetic material is advantageous for maintaining flexibility. Depending on the positional relationship between the shield wall and the blocking member, the magnetic ribbon is distorted by bending or twisting. However, since the inverse magnetostriction effect is unlikely to occur, the magnetic characteristics are hardly deteriorated.
[0016]
The magnetic ribbon used in the present invention is preferably a magnetic sheet produced by joining thin magnetic bodies used as materials and spreading them into a sheet. The thickness of the magnetic sheet is 10 μm to 200 μm, and the magnetic ribbon can be configured by laminating two or more magnetic sheets according to the amount of magnetic flux flowing. The narrow magnetic body should be an amorphous alloy material or a sheet-like or tape-like shape composed of an alloy material in which fine crystal grains having a grain size of 500 nm or less, whose main component is iron element, occupy at least 50% of the structure. Is preferred. This magnetic material is excellent in magnetic properties, but it is preferable to laminate about 5 to 15 sheets in order to prevent magnetic saturation.
[0017]
The single magnetic sheet can be formed by arranging thin magnetic bodies in parallel without gaps and integrating them with a resin. In order to arrange them without gaps, adjacent narrow magnetic bodies may be partially overlapped or edges may be abutted.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is an external view of a magnetic shield room 1 that employs an opening closing structure according to the present invention. In this structure, six shield walls 2 are combined and joined. When the internal space is magnetically shielded, an opening provided in the shield wall 2 is closed with a door (blocking member) 3. The door 3 is attached to the shield wall 2 by a hinge 4 so as to be opened and closed. The shield wall 2 is produced in advance at the factory, and is brought into the installation site and assembled.
[0019]
The opening closing structure according to the first aspect of the present invention will be described with reference to FIGS. 2 is a cross-sectional view taken along the line AA in FIG. (A) shows the state in which the door 3 is open. (B) shows a state in which the door 3 is closed and the opening of the shield wall 2 is closed. The shield wall 2 includes a shield material 5 inside the magnetic shield room 1. The magnetic ribbon 6 is formed of an amorphous alloy material or an alloy material in which fine crystal grains having a particle size of 500 nm or less, whose main component is iron element, occupy at least 50% of the structure. The shield material 5 can be formed of a non-flexible magnetic material such as permalloy or a material similar to the magnetic ribbon 6. The magnetic ribbon 6 has flexibility and is arranged so as to come into contact with the shield material 5 of the shield wall 2 and a part thereof faces the opening of the shield wall 2. The magnetic ribbon 6 and the shield material 5 of the shield wall 2 are preferably bonded. The magnetic ribbon 6 receives a pressing pressure by an elastic member 7 supported by a support plate 8. The magnetic ribbon 6, the elastic member 7, and the support plate 8 are preferably bonded to each other. A sponge, rubber, spring, or the like can be used for the elastic member 7. The position L6 of the surface on the door 3 side of a part of the magnetic ribbon 6 that faces the opening when the door 3 is open is over the position L5 of the surface of the shield material 5 of the door 3 when the door 3 is closed. Wrapping. When the door 3 is closed, the magnetic ribbon 6 is pushed by the shield material 5 of the door 3 from the position L6 to the position L5. When pressed, the magnetic ribbon 6 is urged by the elastic member 7 and is in close contact with the shield material 5 of the door 3. As a result, the shield material 5 of the shield wall 2, the magnetic ribbon 6, the shield material 5 of the door 3, the magnetic ribbon 6, and the shield material 5 of the shield wall 2 are brought into close contact with each other to form a magnetic path. Even if the flatness and parallelism of the magnetic ribbon 6 and the shield material 5 are not ensured with high accuracy, the magnetic ribbon 6 has flexibility, so that they adhere to each other and leakage or intrusion of magnetic flux occurs. Without magnetic coupling. Even if the building is deformed after the magnetic shield room is constructed and the positional relationship between the shield wall 2 and the door 3 is changed, the flexibility of the magnetic ribbon 6 does not affect the degree of adhesion between the magnetic ribbon 6 and the shield material 5. Since the magnetic ribbon 6 has flexibility, no excessive stress is applied even if it is pressed by the shield material 5. In FIG. 2B, the magnetic ribbon 6 is not elastically deformed. However, even if it remains elastically deformed, the magnetic ribbon 6 has sufficient hardness and is hardly affected by stress or strain. The decrease is small, and the leakage of magnetic flux is hardly a problem.
[0020]
FIG. 3 is a cross-sectional view taken along line AA of FIG. 1 according to another embodiment of the present invention. (A) shows the state in which the door 3 is open. (B) shows a state in which the door 3 is closed and the opening of the shield wall 2 is closed. A magnetic ribbon 6 is overlapped on the shield material 5 of the door 3 and fixed with screws 10 through a pressing plate 9 from above. Part of the magnetic ribbon 6 faces the opening of the shield wall 2 and is supported by the support plate 8 via the elastic member 7. When the door 3 is closed as in the embodiment of FIG. 2, the magnetic ribbon 6 is pushed by the shield material 5 of the door 3 from a position L6 (not shown) to a position L5 (not shown). When pressed, the magnetic ribbon 6 is urged by the elastic member 7 and is in close contact with the shield material 5 of the door 3.
[0021]
FIG. 4 is a cross-sectional view taken along line AA of FIG. 1 according to still another embodiment of the present invention. (A) shows the state in which the door 3 is open. (B) shows a state in which the door 3 is closed and the opening of the shield wall 2 is closed. In the above-described embodiment, the shield material 5 of the shield wall 2 and the magnetic ribbon 6 are separate members. However, the magnetic ribbon having flexibility can be used as one member. Since the magnetic joint between the shield material 5 and the magnetic ribbon 6 on the shield wall 2 is eliminated, the magnetic resistance of the magnetic path is reduced and the reliability is improved.
[0022]
FIG. 5 shows a construction example when the opening of the shield wall 2 is provided at a position close to the corner of the magnetic shield room. The magnetic ribbon 6 is extended to extend to a position beyond the corner portion, where it is joined with another shield material. Alternatively, the magnetic ribbon 6 is used as a shield material without using another shield material. Thereby, construction man-hours can be reduced. Although the magnetic ribbon 6 is elastically deformed at the corner, it is R-shaped and has sufficient hardness and is not easily affected by stress or strain. It is a grade not to become.
[0023]
FIG. 6 shows a magnetic sheet 6a formed by arranging narrow magnetic bodies 6aa. The narrow magnetic body has an easy magnetization direction He and a hard magnetization direction Hd. The magnetic sheet 6a has a thickness of 10 to 200 μm. A required number of magnetic sheets 6a are laminated so as not to saturate the magnetic flux, thereby forming the magnetic ribbon 6 or the shield material 5. The magnetic sheets are bonded with an adhesive wax. For example, ten magnetic sheets having a thickness of 200 μm can be laminated to form the magnetic ribbon 6 or the shield material 5 having a thickness of about 2000 μm.
[0024]
The narrow magnetic body 6aa constituting the magnetic ribbon 6 or the shield material 5 is an amorphous alloy material or an alloy material in which fine crystal grains having a grain size of 500 nm or less, whose main component is iron element, occupy at least 50% of the structure. It is formed and has a sheet-like or tape-like shape. As the fine crystal material of the iron alloy (Fe alloy), a soft magnetic material having a fine crystal structure (or fine crystal grains) of bccFe of an Fe—Cu—Nb—Si—B system is desirably used. More desirably, a material in which the average crystal grain size of the fine crystal grains is 100 nm or less is used. This iron alloy (Fe alloy) fine crystal material (also referred to as nanocrystal material) can be obtained by heat-treating an amorphous material at a desired temperature as disclosed in, for example, Japanese Patent No. 2625485. Since the magnetic flux in the space can be collected efficiently in the configuration of this patent, it is possible to use a magnetic material that is thinner than a conventional magnetic shield. In order to obtain a thin magnetic body, for example, there is a foil body by rolling or ultra-quenching method, but soft iron or NiFe alloy that is easy to roll, or amorphous foil body obtained by ultra-quenching, the deformation of the sheet material is due to the reverse strain effect etc. Since characteristic deterioration is likely to occur, problems such as difficulty in handling in the construction of shield walls may occur. In particular, in NiFe alloy, the hardness of the material is insufficient, and crystal defects generated by deformation of the sheet due to the weight of the shield wall significantly deteriorate the magnetic characteristics. On the other hand, in the magnetic sheet obtained by heat-treating a foil body formed by ultra-rapid cooling of a high permeability Fe-based alloy, the obtained Fe-based alloy is sufficiently hard and has an inverse magnetostrictive effect. It is difficult to obtain a sufficiently thin magnetic sheet. In addition, as described in JP-A-6-112031, it is possible to make the material difficult to break against mechanical deformation and to significantly reduce the shape restrictions on processing. In the magnetic shield room using this magnetic sheet, the shield wall can be reduced in weight, and the influence of stress can be eliminated as much as possible, so that the material can be handled easily during construction.
[0025]
【The invention's effect】
According to the present invention, even if the flatness and parallelism between the shield wall and the closing member that closes the opening are not ensured with high accuracy, both can be magnetically coupled without causing leakage or intrusion of magnetic flux. An opening closing structure can be provided.
According to the present invention, there is provided an opening closing structure capable of magnetically coupling a shield wall and a closing member for closing the opening without applying magnetic flux without causing leakage or intrusion of magnetic flux. Can do.
[Brief description of the drawings]
FIG. 1 is an external view of a magnetic shield room that employs an opening closing structure according to the present invention.
2 is a cross-sectional view taken along the line AA of FIG. 1 in the embodiment of the present invention, where (a) shows a state where the door is open, and (b) shows a state where the door is closed and the opening of the shield wall is closed. Indicates.
3 is a cross-sectional view taken along the line AA of FIG. 1 in another embodiment of the present invention, wherein (a) shows a state where the door is open, and (b) shows that the door is closed and the opening of the shield wall is closed. Shows the state.
4 is a cross-sectional view taken along the line AA of FIG. 1 in still another embodiment of the present invention, wherein (a) shows a state where the door is open, and (b) shows that the door is closed and the opening of the shield wall is opened. Indicates a blocked state.
FIG. 5 shows a construction example when the opening of the shield wall is provided at a position near the corner of the magnetic shield room.
FIG. 6 is a magnetic sheet formed by arranging narrow magnetic bodies.
FIG. 7 shows a first conventional structure for ensuring magnetic shielding performance at the opening of the shield wall.
FIG. 8 is a second conventional structure for ensuring magnetic shielding performance at the opening of the shield wall.
[Explanation of symbols]
1 ... Magnetic shield room 2 ... Shield wall 3 ... Door (blocking member)
4 ... Hinge 5 ... Shielding material 6 ... Magnetic ribbon 6a ... Magnetic material sheet 6aa ... Narrow magnetic material 7 ... Elastic member 8 ... Support plate 9 ... Holding plate 10 ... Screw

Claims (3)

A shield wall, a shield material provided on the shield wall, a closing member that closes the opening of the shield wall, a shield material provided on the closing member, and the shield wall when the opening is closed with a closing member And a magnetic ribbon that contacts both the shield member on the side and the shield member on the closure member side, and the magnetic ribbon has its own flexibility, and one end side thereof is A surface on one end of the magnetic ribbon that faces the opening when the elastic member is disposed on the back surface opposite to the opening and the closing member is open. Is in the opening, the other of the magnetic ribbon contacts the shield material on the shield wall side, the back of the magnetic ribbon is pressed by the elastic member, and the blocking member opens the opening Magnetic ribbon facing the opening when closing The surface on the one end side is in close contact with the surface of the shield member on the closing member side against the pressing force of the elastic member, and comes into close contact with the surface, and in the state where the closing member is closed, the surface on the one end side Is pressed against the surface of the shield member of the blocking member to be flush with the opening structure of the magnetic shield room. A shield wall; a magnetic ribbon provided on the shield wall; a closing member that closes an opening of the shield wall; a shield material provided on the closing member; and the shield when the opening is closed with a closing member An opening closing structure in which a magnetic ribbon on the wall side and a shield material on the closing member side are in contact with each other, and the magnetic ribbon has its own flexibility, and one end side thereof faces the opening. Further, an elastic member is disposed on the back surface opposite to the opening, and when the closing member is open, the surface on one end side of the magnetic ribbon facing the opening enters the opening. The other of the magnetic ribbon is in contact with the shield wall side, the back surface of the magnetic ribbon is pressed by the elastic member, and when the closing member closes the opening, the magnetic facing the opening The surface on one end side of the ribbon is resistant to the pressing force of the elastic member. While being pushed to the surface of the closure member side shield member Te, close contact by surface contact, in the closed state of the closing member, the surface of one end side is pushed to the surface of the shield material of the closure member flush A structure for closing a magnetic shield room opening. The magnetic thin ribbon is formed of an amorphous alloy material or an alloy material in which fine crystal grains having a particle size of 500 nm or less, the main component of which is an iron element, occupy at least 50% of the structure. The opening structure of the magnetic shield room described.

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