JP7479638B2 - Large shielded door with electromagnetic shielding structure - Google Patents

Description

The present invention relates to a large shielded door with an electromagnetic wave shielding structure that is installed at the entrances and exits of buildings and has a function to prevent electromagnetic wave leakage.

A building with the function of blocking electromagnetic waves (hereinafter referred to as a shielding function) is covered with metal plates that are electrical conductors, and has a structure that blocks the propagation of electromagnetic waves between the inside and outside of the building. The building may be large or small depending on its intended use. More generally, in consideration of the generation of electromagnetic waves inside the building, an electromagnetic wave absorbing structure for absorbing electromagnetic waves generated inside the building is provided on the inside of the building.

In a typical building with a shielding function, the entrance for people to enter and exit is provided with a metal door large enough for people to enter and exit. In addition, in order to prevent electromagnetic waves from leaking between the entrance of the building and the metal door, the entrance is provided with a structure that prevents electromagnetic waves from leaking.

As an example of a structure for preventing electromagnetic wave leakage, a door frame is provided around the periphery of an entrance to a building, and a door body is provided at the opening of the entrance so that it can be opened and closed. The door frame and the door body that opens and closes have overlapping portions, and the door body and the door frame are electrically connected at the overlapping portions.

For example, a specific structure is such that conductive shield fingers are attached around the entire periphery of the door frame, and the door body is provided with a knife plate around its entire periphery that can fit into the shield fingers. When the door body is closed, the knife plate of the door body is inserted into the shield fingers, and they are electrically connected. This structure makes it possible to prevent leakage of electromagnetic waves. This technology is described in Patent Documents 1 and 2.

Patent No. 3439611 Patent No. 3253904

The electromagnetic shielding technology described in Patent Documents 1 and 2 is intended to be applied to small opening and closing doors. However, there is a need in the world not only for the small opening and closing doors mentioned above, but also for large electromagnetic shielding doors to be used in buildings with large opening areas. Such large shielding doors have various new issues that must be resolved, such as the door as a whole becoming very heavy, and the area of the part that must prevent the leakage of electromagnetic waves becoming very large. For this reason, the large shielding doors mentioned above cannot be manufactured using only the electromagnetic shielding technology that has been applied to conventional small opening and closing doors.

The present invention aims to provide a large door with an electromagnetic wave shielding structure that can prevent electromagnetic waves from leaking from the entrances and exits of large shielded buildings.

[First Invention]
The first invention for solving the above problems is a large shielded door with an electromagnetic wave shielding structure to be installed at the entrance of a shielded building with an electromagnetic wave shielding function,
The height direction of the shield building is defined as the Z-axis of a rectangular coordinate system, the direction from the entrance side of the shield building to the opposite side of the entrance side of the shield building is defined as the Y-axis of the rectangular coordinate system, and the direction from left to right when looking from the entrance side of the shield building to the opposite side of the entrance is defined as the X-axis of the rectangular coordinate system.
the large shielding door has a central shielding panel for shielding electromagnetic waves provided along an X-Z plane based on the X-axis and the Z-axis, a leakage prevention mechanism having an outer peripheral front panel provided to surround the outer periphery of the central shielding panel along the X-Z plane for preventing leakage of electromagnetic waves, and a number of moving mechanisms for moving the outer peripheral front panel of the leakage prevention mechanism in the Y-axis direction;
This is a large shielded door with an electromagnetic wave shielding structure, characterized in that the outer peripheral front panel is moved in the Y-axis direction by the multiple moving mechanisms, and the outer peripheral front panel is brought into close contact with the outer periphery of the entrance/exit of the shielded building, thereby preventing leakage of electromagnetic waves.

[Effects of the first invention]
Conventional large doors for shielding electromagnetic waves have a problem that they are very heavy because they are made of metal materials with excellent electromagnetic wave shielding properties and have a structure that maintains the strength of the large door. In addition, in order to effectively shield the leakage of electromagnetic waves, it is very important to prevent the leakage of electromagnetic waves between the entrance of the shielded building and the large door, and in order to prevent the leakage of electromagnetic waves, it is necessary to maintain the electrical connection between the entrance of the shielded building and the large door around the entire circumference of the entrance.

The entrance to the shielded building can be opened and closed by moving the large shielded door relative to the entrance in the left-right or up-down direction. The movement between the entrance and the large shielded door for electromagnetic wave shielding is completely different from the opening and closing of the entrance. In other words, the movement for opening and closing the entrance is in the X-axis or Z-axis direction, while the movement for shielding electromagnetic waves is in the Y-axis direction.

In the first invention, the large door has a central shielding panel and a leakage prevention mechanism that is provided to surround the outer periphery of the central shielding panel. The leakage prevention mechanism further has an outer periphery front panel for electrically connecting with the entrance of the shield building to prevent leakage of electromagnetic waves. Prevention of leakage of electromagnetic waves is achieved by moving the outer periphery front panel in the Y-axis direction to electrically connect with the outer periphery of the entrance of the shield building. There is no need to move the central shielding panel for the electrical connection between the outer periphery of the entrance of the shield building and the outer periphery front panel. The number of moving objects is reduced, and the weight of the moving objects in the Y-axis direction to prevent leakage of electromagnetic waves is reduced. This makes it easier to control the positional relationship between the entrance of the shield building and the connection part of the large door and the pressing force for electrical connection, improving the reliability of preventing leakage of electromagnetic waves.

Earthquakes occur frequently in Japan. Even if an earthquake occurs while the entrance to the building is closed by the large door, it is desirable to have a structure in which the connection between the outer peripheral front panel of the leakage prevention mechanism of the large door and the shield building will not be separated by an earthquake or the like. In the first invention, the outer peripheral front panel moves to connect to the shield building, and the mass of the outer peripheral front panel is very small compared to the overall mass of the large shield door. This has the effect of stably maintaining the pressing force for electrical connection. Even in the event of an earthquake, it has the effect of making it easier to maintain the connection between the outer peripheral front panel of the leakage prevention mechanism of the large door and the shield building.

[Second Invention]
The second invention for solving the above problem is a large shielded door equipped with the electromagnetic wave shielding structure of the first invention,
A shield receiving frame is provided along the outer periphery of the entrance of the shield building,
The shield receiving frame is provided with a plurality of first gaskets made of metal,
The outer peripheral front panel of the leakage prevention mechanism is made of a metal plate,
The outer peripheral front panel is provided at a position facing the shield receiving frame of the shield building when the large shield door is closing the entrance of the shield building,
The large shield door has an internal connection mechanism for electrically connecting the outer peripheral front panel and the central shielding panel,
When the leakage prevention mechanism is in a state of preventing leakage of electromagnetic waves at the entrance and exit of the shielded building, the outer peripheral front panel is moved in the Y-axis direction by the multiple moving mechanisms to press the multiple first gaskets provided on the shield receiving frame, and the outer peripheral front panel is electrically connected to the shield receiving frame.
This is a large shielded door equipped with an electromagnetic wave shielding structure characterized by the above.

[Effects of the second invention]
In the second invention, as already explained in the first invention, the leakage prevention mechanism itself is provided with a number of the moving mechanisms for moving the outer peripheral front panel of the leakage prevention mechanism in the Y-axis direction. The large shielding door is not moved as a whole in the Y-axis direction, and the leakage prevention mechanism is not moved as a whole in the Y-axis direction. The leakage prevention mechanism itself is not moved in the Y-axis direction. The outer peripheral front panel of the leakage prevention mechanism is moved by a number of the moving mechanisms provided in the leakage prevention mechanism itself, so that the entire structure of the large shielding door and the mechanism supporting the large shielding door can be greatly simplified. Furthermore, the central shielding panel part of the large shielding door and the moving mechanism and the part supporting it of the leakage prevention mechanism do not need to move in the Y-axis direction, and the outer peripheral front panel of the leakage prevention mechanism can be moved while the many moving mechanisms are fixed to the parts that do not move, which makes it easier to control the movement and improves the control accuracy.

When the second invention is applied to the door of a large shielded building with a particularly high floor height, for example, the inter-story deformation due to an earthquake becomes large, but the deformation of the large shielded door blocking the entrance to the shielded building does not become so large. Therefore, the deformation of the entrance of the building does not match the deformation of the large shielded door that is the subject of the present invention. This causes a misalignment at the contact surface between the two. However, in the present invention, even if a misalignment occurs at the contact surface between the first gasket provided on the shield receiving frame and the outer peripheral front panel of the large door due to this behavior, the mass of the outer peripheral front panel is small, so the vibration energy is small, and the vibration energy of the outer peripheral front panel is absorbed by the first gasket. In addition, the first gasket can deform in response to the vibration of the outer peripheral front panel, the electrical connection is maintained, and the deterioration of shielding performance during an earthquake is suppressed.

[Third Invention]
The third invention for solving the above problems is a large shielded door equipped with the electromagnetic wave shielding structure of the second invention,
the movement mechanism includes a number of air cylinders arranged at predetermined intervals along the axial direction of the long side and the short side of the leakage prevention mechanism, a number of springs arranged at predetermined intervals, and an air pipe that supplies the compressed air to the number of air cylinders,
The force of each spring acts in a direction to move the outer peripheral front panel away from the shield receiving frame,
The multiple air cylinders operate in a direction to move the outer peripheral front panel closer to the shield receiving frame against the force of the multiple springs by the compressed air supplied through the air pipes, and the force of the multiple air cylinders becomes greater than the force of the multiple springs, so that the outer peripheral front panel is electrically connected to the shield receiving frame through the multiple first gaskets.
This is a large shielded door equipped with an electromagnetic wave shielding structure characterized by the above.

[Effects of the third invention]
As described above, the large shielding door of the present invention is divided into the central shielding panel and the leakage prevention mechanism, and the central shielding panel does not move, but the peripheral front panel of the leakage prevention mechanism moves toward the shield receiving frame installed at the entrance of the shielding building. A large number of the moving mechanisms are provided to move the peripheral front panel. In order to prevent leakage of electromagnetic waves, it is desirable that the pressure of the entire peripheral front panel against the shield receiving frame of the shielding building be as uniform as possible.

On the other hand, the leakage prevention mechanism is made of a metal material, has a large thermal expansion coefficient, and its dimensional relationship changes depending on the temperature. Furthermore, for large doors, it is required to complete the large shield door at the installation site by a method such as welding. In such cases, it is preferable that the structure does not require high manufacturing precision. In the third invention, the pressure of the entire outer peripheral front panel of the leakage prevention mechanism against the shield receiving frame of the shield building can be made almost uniform throughout the entire leakage prevention mechanism, and the effect of stabilizing it can be achieved. That is, compressed air made by the same compression means is distributed and supplied to the multiple air cylinders through the air pipe. Even if there is variation in the internal mechanical contact resistance of each air cylinder, the value that the difference in the contact resistance has on the pressure of each air cylinder is very small compared to the value on which the compressed air acts. Therefore, the force of each air cylinder on the outer peripheral front panel can be determined by the relationship between the pressure of the compressed air and the force of the spring. Since the compressed air is distributed through the air pipe from the same compressed air source, the force of each air cylinder is almost uniform. Therefore, if the characteristics of each spring are made almost uniform, the pressure of the entire leak prevention mechanism against the shield receiving frame of the shield building can be made almost uniform. The spring is a component whose characteristics can be easily made uniform. Furthermore, the outer peripheral front panel of the leak prevention mechanism is held in place when the elastic force of the multiple first gaskets between the shield receiving frame and the outer peripheral front panel and the pressure determined by the springs and the air cylinders are balanced, so dimensional variations due to thermal expansion, manufacturing errors, etc. can be eliminated. Furthermore, even if there is a slight time difference in the supply of compressed air to each air cylinder, the air cylinders are configured to operate against the spring pressure, so the problem of time differences in the supply of compressed air can be eliminated.

[Fourth Invention]
The fourth invention for solving the above problems is a large shielded door equipped with the electromagnetic wave shielding structure of the third invention,
the leakage prevention mechanism for preventing leakage of electromagnetic waves provided on the outer periphery of the central shielding panel of the large shield door along the X-Z plane is composed of a number of unit leakage prevention mechanisms,
Each of the unit leakage prevention mechanisms includes a unit outer peripheral front panel, a plurality of the springs acting in a direction to move the unit outer peripheral front panel away from the shield receiving frame, and the air cylinder generating a force against the springs to move the unit outer peripheral front panel closer to the shield receiving frame,
The unit peripheral front panels of the multiple unit leakage prevention mechanisms are connected to each other by seam welding to form the peripheral front panel.
This is a large shielded door equipped with an electromagnetic wave shielding structure characterized by the above.

[Effects of the fourth aspect of the invention]
The door targeted by the present invention is extremely large. In such a large shielded door, the leakage prevention mechanism for preventing leakage of electromagnetic waves provided on the central shielding panel and its periphery is also very large compared to conventional shielded doors. It is almost impossible to manufacture a large shielded door in a factory and bring it to the installation site. Not only that, it is almost impossible to complete the leakage prevention mechanism in a factory and bring it to the installation site. For this reason, in the present invention, the leakage prevention mechanism is divided into unit leakage prevention mechanisms, the divided unit leakage prevention mechanisms are manufactured in a factory, transported in a divided state to the installation site, and joined together at the installation site to complete the leakage prevention mechanism. Furthermore, by connecting the unit peripheral front panels to each other by seam welding, the seam welded parts can be easily removed, unlike connections by other welding methods. Furthermore, it is possible to easily reconnect them after maintenance.

Generally, when the outer periphery front panel of the leakage prevention mechanism is joined and completed at the installation site, the manufacturing precision is not obtained, and problems such as not achieving the desired performance arise. However, the present invention can ensure sufficient performance. The reason is that the movement mechanism that moves the outer periphery front panel of the leakage prevention mechanism in the Y axis, as described above, is equipped with the plurality of springs that act in a direction to move the unit outer periphery front panel away from the shield receiving frame, and the air cylinder that generates a force against the spring and acts in a direction to move the unit outer periphery front panel closer to the shield receiving frame. As described above, the unit outer periphery front panel is moved by the forces of the spring and the air cylinder acting in opposing directions, so that the precision required for joining the unit outer periphery front panel can be reduced. That is, in the present invention, even if the joining precision between the unit outer periphery front panels is not high, the pressure between the integrated outer periphery front panel and the gasket provided on the shield receiving frame and the timing of the movement of the entire outer periphery front panel can be made uniform throughout the entire outer periphery front panel. Therefore, even if the large shield door is completed at the installation site, a stable electrical connection can be ensured.

[Fifth Invention]
The fifth invention for solving the above problems is a large-sized shielded door equipped with the electromagnetic wave shielding structure according to any one of the third and fourth inventions,
The internal connection mechanism for electrically connecting the outer peripheral front panel and the central shielding panel includes a side panel that is mechanically connected to the outer peripheral front panel, extends in the Y-axis direction in the opposite direction to the shield receiving frame, and has a tip that forms a folded end;
A folded panel that is mechanically connected to the side panel at the folded end, which is the tip portion of the side panel, and extends parallel to the side panel toward the shield receiving frame;
A central side panel is connected to an end of the central shielding panel, is located between the side panel and the folded panel, and extends in a direction along the Y axis and in a direction opposite to the shield receiving frame,
a second gasket is provided on the inside of the folded end of the side panel, which is a mechanical connection between the side panel and the folded panel;
Further, a third gasket is provided between the side panel and the central side panel at a position shifted from the end of the side panel toward the peripheral front panel,
a fourth gasket is provided between the folded panel and the central side panel at a position shifted from the end of the side panel toward the peripheral front panel;
In a state in which the outer peripheral front panel and the shield receiving frame are electrically connected via the first gasket, an end portion of the central side panel is electrically connected to the inside of the end portion of the side panel via the second gasket, the side panel and the central side panel are further electrically connected via the third gasket, and the folded panel and the central side panel are electrically connected via a fourth gasket.
This is a large shielded door equipped with an electromagnetic wave shielding structure characterized by the above.

[Effects of the fifth invention]
In the fifth invention, in order to prevent leakage of electromagnetic waves between the shielded building and the large shielded door, the leakage prevention mechanism of the large shielded door is moved toward the shielded receiving frame of the shielded building and electrically connected to the shielded receiving frame via the first gasket. At this time, the central shielding panel of the large shielded door does not move. Therefore, it is necessary to prevent leakage of electromagnetic waves between the central shielding panel and the leakage prevention mechanism.

When the frequency of the electromagnetic waves in question is very high, for example, in the case of ultra-high frequencies such as 50 GHz, which is a frequency much higher than 1 gigahertz (hereinafter referred to as GHz), special measures are required to prevent leakage. In the fifth invention, two types of leakage blocking sections are provided to minimize leakage even for electromagnetic waves of such very high frequencies. The first leakage blocking section is structured by providing the third gasket between the side panel and the central side panel described above, and providing the fourth gasket between the folded panel and the central side panel, and is highly effective in preventing leakage of electromagnetic waves with frequencies higher than 1 GHz.

The fifth invention further includes a second leakage blocking section that has a greater leakage prevention effect for lower frequencies, for example, frequencies below several GHz. The second leakage blocking section is the folded end of the side panel, which is a mechanical connection between the side panel and the folded panel. The second gasket is provided inside this folded end, and the second gasket and the end of the central side panel are electrically connected, thereby providing a great effect in preventing leakage for frequencies below several GHz. In this invention, by providing the first leakage blocking section and the second leakage blocking section, a good leakage prevention effect is provided overall for electromagnetic waves with frequencies lower than several GHz as well as for electromagnetic waves with frequencies higher than several GHz, for example, 50 GHz.

[Sixth Invention]
The sixth invention for solving the above problem is a large shielded door with an electromagnetic shielding structure according to any one of the second to fifth inventions, characterized in that each of the first gaskets is a rod-shaped metal net formed by overlapping multiple times a metal net made by weaving metal wires.

[Effects of the sixth aspect of the invention]
A plurality of the first gaskets can prevent leakage of electromagnetic waves of a wide range of frequencies, from 1 GHz or less to 1 GHz or more, for example, about 50 GHz. By forming a structure in which a metal net made by weaving metal wires having finer meshes than the wavelength is layered multiple times, the energy of the electromagnetic waves can be consumed and attenuated, and leakage of the electromagnetic waves can be suppressed. In an experiment conducted by the inventors, it was confirmed that the effect of suppressing leakage of electromagnetic waves of a wide range of frequencies, from 1 GHz or less to about 50 GHz, can be achieved by forming a structure in which a metal net made by weaving metal wires is layered multiple times as the first gasket.

[Seventh Invention]
The seventh invention for solving the above problems is a large shielded door equipped with an electromagnetic wave shielding structure according to any one of the first to sixth inventions, wherein the central shielding panel is formed by connecting a plurality of unit central shielding panels to each other,
Each of the unit central shielding panels has both ends bent at right angles to the surface of the central portion of the unit central shielding panel to form a connection portion, and the ends of the connection portion are bent at right angles to form a folded portion, and a folded portion is formed between the connection portion and the folded portion;
The plurality of unit central shielding panels forming the central shielding panel are arranged such that the connection portions of the respective unit central shielding panels face each other, so that the folded portions of the unit central shielding panels are arranged close to each other;
The shield metal is pressed against the bent portions arranged close to each other by a pressing metal plate, and the pressing metal plate is fixed by a fastener.
This is a large shielded door equipped with an electromagnetic wave shielding structure characterized by the above.

[Effects of the seventh aspect of the invention]
The central shielding panel is made by joining the unit central shielding panels together. Furthermore, as a method for connecting the unit central shielding panels, the shielding metal is sandwiched between the bent portions of the adjacent unit central shielding panels by the pressing metal plate. The pressing metal plate applies pressure to the shielding metal to deform it. In this manner, the adjacent unit central shielding panels are electrically connected. This allows for a highly reliable connection. For example, when attempting to connect the adjacent unit central shielding panels by commonly used welding, maintaining reliability becomes a major issue if the area of the central shielding panels becomes large. The present invention can solve such issues.

[Eighth Invention]
The eighth invention to solve the above problems is a large shielded door equipped with the electromagnetic wave shielding structure of any one of the first to seventh inventions,
The large shield door has a shape having a long side and a short side in the X-Z plane based on the X-axis and the Z-axis, the long side being 4 m or more and the short side being 3 m or more.
Alternatively, the large shield door has an area of 12 square meters or more in the X-Z plane based on the X-axis and the Z-axis.
This is a large shielded door equipped with an electromagnetic wave shielding structure characterized by the above.

[Effects of the Eighth Invention]
In recent years, there has been a need for large shielded buildings with electromagnetic shielding functions, and the large shielded buildings require large shielded doors to prevent leakage of electromagnetic waves from their entrances. Even if a conventional shielded door is simply enlarged, it cannot be easily enlarged due to the new problem associated with enlarging the shielded door as described above. This new problem can be solved by the first to seventh inventions described above. Therefore, when the shielded door having the configuration of the first to seventh inventions is applied to a large shielded door, for example, a shielded door having a long side of at least 4 m or more and a short side of at least 3 m or more in the X-Z plane, a great effect can be obtained. Similarly, when the present invention is applied to a shielded door having an area of 12 square meters or more in the X-Z plane, a great effect can be obtained.

For example, even if the shield door has a long side of 4 m or more and a short side of 3 m or more, or the shield door is 12 square meters or more, the configuration described in the first to seventh inventions significantly reduces the weight of the object to be moved in the Y-axis direction, and a great effect is exhibited in terms of simplifying the moving mechanism and ease of control. In addition, if the shield door has a long side of 4 m or more and a short side of 3 m or more, the conventional method of manufacturing it in a factory and transporting it to the installation site will cause various problems and is not realistic. A realistic method is to divide the large shield door, manufacture each divided part in a factory, and finally complete it at the installation site. In this case, it is very important that the final assembly is easy and that high manufacturing precision is not required. Such problems can be solved in the first to seventh inventions described above. Therefore, it is very effective for large shield doors with long sides of 4 m or more and short sides of 3 m or more. Furthermore, it is extremely effective when the long side is 10 m or more, or 50 m or more, or 100 m or more, and the short side is 5 m or more, or several tens of meters or more, or even longer, such as 30 meters or more, or when applied to a shield door whose area in the X-Z plane is 12 square meters or more, or even several times larger than this.

The present invention provides a large shielded door with an electromagnetic wave shielding structure that can prevent electromagnetic waves from leaking from the entrances and exits of large shielded buildings.

FIG. 1 is an explanatory diagram illustrating a shielded building provided with a large shielded door according to the present invention. 2 is a cross-sectional view of the shield building 10 shown in FIG. 1 along line AA. 1 is a partially enlarged view of a leakage prevention mechanism on one side of a large shield door to which the present invention is applied. 13 is a partial enlarged view of the leakage prevention mechanism on the other side of the large shield door to which the present invention is applied. FIG. FIG. 2 is a partially enlarged view of the leakage prevention mechanism shown in FIG. 1 . An explanatory diagram illustrating the connection structure of unit central shielding panels that make up the central shielding panel. 4 is an explanatory diagram of a second leakage interrupter shown in FIG. 3 . FIG.

Below, an embodiment of the present invention will be described in detail with reference to the drawings. Note that components having the same functions will be given the same reference numerals, and repeated explanations may be omitted.

1. Overall structure of the shield building 10 The overall structure of the shield building 10 will be described with reference to Figures 1 and 2. In the following description of the embodiment, the height direction of the shield building 10 is defined as the Z axis of a rectangular coordinate system, the direction from the entrance of the shield building 10 to the side opposite the entrance of the shield building 10 is defined as the Y axis of the rectangular coordinate system, and the direction from left to right when looking from the entrance of the shield building 10 to the side opposite the entrance is defined as the X axis of the rectangular coordinate system. Figure 2 is a cross-sectional view of Figure 1 taken along the line A-A, showing a cross section along the X-Y plane indicated by the dashed line. The shield building 10 is an example, and the size and shape are not limited to this. The shield building 10 is entirely covered with a metal plate with low electrical resistance, and is electrically grounded by a grounding means (not shown). A large shield door 100 is provided at the entrance of the shield building 10. The large shielded door 100 is also constructed using a metal plate with low electrical resistance, and the large shielded door 100 itself may be grounded, or may be grounded by being electrically connected to the shielded building 10. Alternatively, both of these may be used.

When the large shielding door 100 moves vertically along the Z axis or horizontally along the X axis, the entrance of the shielding building 10 is opened. When the shielding building 10 returns from the moving state to its original position, the entrance of the shielding building 10 is closed. As described above, the shielding building 10 and the large shielding door 100 themselves are constructed to block electromagnetic waves with metal plates, but electromagnetic waves leak between the large shielding door 100 and the shielding building 10. In order to effectively block electromagnetic waves between the inside and outside of the shielding building 10, it is necessary to prevent the leakage of electromagnetic waves between the large shielding door 100 and the shielding building 10 described above. For this reason, it is necessary to completely electrically connect the large shielding door 100 and the shielding building 10 around the entire circumference.

2. New needs and new issues A door that is generally used to prevent leakage of electromagnetic waves is large enough for a person to enter and exit. However, there are various needs in the world, and there is a need to use a very large door that can accommodate vehicles, ships, aircraft, etc. A rectangular shape will be used as an example of the size. Of course, it is not necessary to be limited to a rectangular shape, and it may be, for example, a kamaboko shape or an elliptical shape. In order to meet such needs, the size of the large shielded door 100 assumed in this embodiment is, for example, 4 m or more, 10 m or more, or even larger, 50 m or more, or even several hundred meters or more on the long side. In addition to the long side, the short side of the large shielded door 100 is also assumed to be very large, for example, 3 m or more, 10 m or more, or 30 m or more. Alternatively, the large shielded door 100 is targeted for an area in the X-Y plane based on the X-axis and the Y-axis of the large shielded door 100 having an area of 12 square meters or more, or several times that size. In the case of a fish cake shape other than a rectangle, the long side is the base of the fish cake shape, and the short side is the line perpendicular to the base and passing through the apex of the curve of the fish cake shape. In the case of an ellipse, the long side is the major axis of the ellipse, and the short side is the minor axis of the ellipse.

To prevent electromagnetic wave leakage in a shielded building 10 having such a large shielded door 100, it is necessary not only to solve the electrical problem of electromagnetic waves, but also to solve the problem of whether the large shielded door 100 can follow inter-layer changes in the shielded building 10 during an earthquake and maintain its shielding performance, which is a problem of a large structure. In addition, there is a need for the electromagnetic waves to be blocked to include very high frequencies. For example, there is a need to block electromagnetic waves including frequencies from below 1 GHz to above 1 GHz, for example, around 50 GHz.

As a measure against electromagnetic wave leakage as described above, it is extremely important to know how to prevent electromagnetic wave leakage between the shielded building 10 and the large shielded door 100. The basic operation is to move the large shielded door 100 in the Y-axis direction toward the shielded building 10 in Figures 1 and 2, and to completely electrically connect the shielded building 10 and the large shielded door 100 without leakage. However, as described above, it is very difficult to move the large and heavy shielded door 100 itself not only in the up and down or left and right directions, but also in the Y-axis direction, which is the direction of the shielded building 10. In addition, there are major problems such as whether the distance between the shielded building 10 and the large shielded door 20 can be controlled with a predetermined accuracy by moving the heavy large shielded door 100, or whether the pressure applied by the large shielded door 100 to the shielded building 10 can be properly controlled during electrical connection.

3. Solutions to problems associated with enlargement of the large shielding door 100 In order to solve the above-mentioned problems, in this embodiment, the large shielding door 100 is divided into at least a central shielding panel 132 located in the center and a leakage prevention mechanism 110 provided to surround the central shielding panel 132. As described above, the leakage prevention mechanism 110 is provided to surround the entire outer periphery of the central shielding panel 132, and includes a right leakage prevention mechanism 112, an upper leakage prevention mechanism 114, a left leakage prevention mechanism 116, and a lower leakage prevention mechanism 118 that are mechanically integrated. Although not shown in FIG. 1, the shield receiving frame 12 is fixed to the outer periphery of the entrance of the shielding building 10 by a receiving frame fixing mechanism 20 so as to surround the entrance of the shielding building 10. The right-side leakage prevention mechanism 112, the upper-side leakage prevention mechanism 114, the left-side leakage prevention mechanism 116, and the lower-side leakage prevention mechanism 118 constituting the leakage prevention mechanism 110 face each side constituting the shield receiving frame 12 of the shield building 10. In Fig. 2, the right-side leakage prevention mechanism 112 faces the shield receiving frame 12 on the right outer periphery, and the left-side leakage prevention mechanism 116 faces the shield receiving frame 12 on the left outer periphery.

In this embodiment, in order to prevent leakage of electromagnetic waves from between the shielded building 10 and the large shielded door 100, the leakage prevention mechanism 110 moves in the direction of the shielded frame 12 provided on the shielded building 10, which is perpendicular to the central shielding panel 132, in other words, in the Y-axis direction, and the leakage prevention mechanism 110 and the shielded frame 12 are electrically connected to the shielded frame 12 via the gasket 14 described below. In this way, leakage of electromagnetic waves is prevented. In this embodiment, instead of moving the entire large shielded door 100 in the Y-direction, which is the direction of the shielded building 10, the peripheral front panel 220 described below of the leakage prevention mechanism 110 provided on the outer periphery of the central shielding panel 132 is moved toward the shielded building 10, and the weight of the object to be moved to prevent leakage of electromagnetic waves can be significantly reduced. This allows the movement mechanism in the Y-axis direction to be significantly simplified to prevent leakage.

4. Effects of moving the outer peripheral front panel 220 of the leakage prevention mechanism 110 In this embodiment, the large shielding door 100 stops moving at a position facing the entrance of the shielding building 10 to close the entrance of the shielding building 10. Next, the outer peripheral front panel 220 of the leakage prevention mechanism 110 moves toward the shield receiving frame 12 provided on the outer periphery of the entrance of the shielding building 10. As a result, even though the large shielding door 100 is very large and very heavy, the weight of the moving part for preventing leakage of electromagnetic waves becomes very small. Furthermore, a moving mechanism for moving to prevent leakage of electromagnetic waves can be provided in the large shielding door 100 itself. Furthermore, in the moving state for preventing leakage of electromagnetic waves, since the large shielding door 100 itself stops moving, the moving mechanism can control the movement of the outer peripheral front panel 220 of the leakage prevention mechanism 110 in a state where the moving mechanism stops moving, which has the effect of stabilizing control. As a result, the electrical connection between the leakage prevention mechanism 110 and the shield receiving frame 12 provided in the shield building 10 is more reliable, and as will be explained below, the pressure between the leakage prevention mechanism 110 and the shield receiving frame 12 can be made almost uniform, and the electrical connection can be maintained in a stable state. Furthermore, these factors result in excellent durability. In Japan, measures against earthquakes are also necessary. As will be explained below, the above-mentioned configuration makes it possible to maintain the above-mentioned electrical connection stably even in the event of an earthquake, and to maintain prevention of electromagnetic wave leakage. In other words, it also has excellent earthquake resistance.

5. Description of the specific structure of the leakage prevention mechanism 110 5.1 Structure on the side of the shield building 10 Figure 3 shows a partial enlarged view (horizontal cross section) of the left leakage prevention mechanism 116 in Figure 2, and Figure 4 shows a partial enlarged view (horizontal cross section) of the right leakage prevention mechanism 112. In reality, the right leakage prevention mechanism 112 and the left leakage prevention mechanism 116 are simply symmetrical in shape, and the relationship between the outer peripheral front panel 220 and the shield receiving frame 12 is always in the same state. In other words, the leakage prevention mechanism 110 consisting of the right leakage prevention mechanism 112 to the lower leakage prevention mechanism 118 is an integrated unit, and always moves as an integrated unit by a moving mechanism consisting of a number of air cylinders 280 described below. However, here, not only the structure of the leakage prevention mechanism 110 but also the state before and after the leakage prevention mechanism 110 starts the operation of preventing leakage of electromagnetic waves will be described using Figures 3 and 4. For this reason, Figure 3 shows the state before the leakage prevention mechanism 110 starts the operation of preventing leakage of electromagnetic waves. On the other hand, Fig. 4 shows the state in which leakage of electromagnetic waves is prevented. Since Fig. 3 and Fig. 4 show different operating states, the positional relationship between the peripheral front panel 220 and the shield receiving frame 12 is different. Note that the structures described in Fig. 1 to Fig. 4 are the same for the upper leakage prevention mechanism 114 and the lower leakage prevention mechanism 118.

First, in Figure 3, the bottom side of the figure is the outside direction at the entrance of the shield building 10, and conversely, the top side of the figure is the inside direction of the shield building 10. As described above, the shield receiving frame 12 is provided all around the entrance of the shield building 10 (not shown). Furthermore, a receiving frame fixing mechanism 20 for supporting the shield receiving frame 12 is provided all around the entrance of the shield building 10 in correspondence with the shield receiving frame 12. The shield receiving frame 12 and the receiving frame fixing mechanism 20 are electrically connected to the shield building 10 and are maintained in an electrically grounded state.

3 is the direction of the upper leakage prevention mechanism 114 shown in FIG. 1, and conversely, the back direction of the figure is the direction of the lower leakage prevention mechanism 118 shown in FIG. 1. The shield receiving frame 12 and the receiving frame fixing mechanism 20 extend long in the Z-axis direction, which is the front-back direction of the figure, and are connected to the receiving frame fixing mechanism 20 (not shown) and the shield receiving frame 12 (not shown) at positions corresponding to the upper leakage prevention mechanism 114 and the lower leakage prevention mechanism 118. A plurality of gaskets 14 are provided on the outer peripheral front panel 220 side of the shield receiving frame 12. In this embodiment, there are four gaskets. Like the shield receiving frame 12 and the receiving frame fixing mechanism 20, each gasket 14 extends long in the Z-axis direction, which is the front-back direction of the paper, and is connected to the gasket 14 (not shown) at a position opposite the upper leakage prevention mechanism 114 and the lower leakage prevention mechanism 118. In this embodiment, it is assumed that the long side of the large shielded door 100 is approximately 50 m long, in other words, 30 to 70 m long. Thus, four gaskets 14 are arranged in parallel, taking into consideration the size of the large shielded door 100. If the long side is shorter than 30 m, a configuration in which two gaskets 14 are arranged in parallel can also be used. However, in order to more completely prevent the leakage of electromagnetic waves, it is better to increase the number of gaskets 14 arranged in parallel. It is preferable to determine the number of gaskets 14 arranged in parallel by comprehensively considering all of these factors.

5.2 Structure of the gasket 14 and its effect Each gasket 14 is electrically connected to the peripheral front panel 220 by being pressed by the peripheral front panel 220, and serves to prevent leakage of electromagnetic waves from between the peripheral front panel 220 and the shield receiving frame 12. Each gasket 14 is made by overlapping a fine mesh made of woven metal wires several times, in some cases five times or more. Therefore, the gasket 14 is rod-shaped, and the cross section is in a state in which the mesh of the metal wires is overlapped several times. The mesh of the metal wires has a dimension much shorter than the wavelength of, for example, 50 GHz. Therefore, this wire mesh itself has the effect of preventing electromagnetic wave leakage. Furthermore, since it is in a state of being overlapped many times, the effect of preventing leakage of electromagnetic waves is great. As a structure in which the fine mesh of the gasket 14 is overlapped many times, the wire mesh may be overlapped in a spiral shape. Or it may be overlapped in a folded manner.

In addition, in this embodiment, multiple rod-shaped gaskets 14 are arranged in parallel between the shield receiving frame 12 and the outer peripheral front panel 220. In this embodiment, four gaskets 14 are arranged in parallel. Even if there is a small leakage when only one gasket is used, arranging multiple gaskets in parallel will greatly increase the effect of preventing electromagnetic wave leakage. As will be described below, two sets of two gaskets are arranged in parallel to correspond to the air cylinder 280, making it easy to make the pressure between the shield receiving frame 12 and the outer peripheral front panel 220 uniform. By arranging two gaskets 14 in parallel for one air cylinder 280 in this way, the pressure between the shield receiving frame 12 and the outer peripheral front panel 220 can be made uniform over the entire circumference of the entrance of the shield building 10. In addition, as will be described below, the above-mentioned uniformity can be maintained even with manufacturing errors in the shield receiving frame 12 and the outer peripheral front panel 220 and changes in shape due to temperature changes, which is very effective in preventing electromagnetic wave leakage. The relationship between the number of parallel gaskets 14 and the size of the large shield door 100 is as described above. As the large shield door 100 becomes larger, the width of the leakage prevention mechanism 110 becomes wider, the number of parallel air cylinders 280 increases, and the number of parallel gaskets 14 increases.

5.3 Explanation of the structure of the leakage prevention mechanism 110 on the large shielding door 100 side Fig. 3 shows the large shielding door 100 in a position to close the entrance of the shielding building 10. After this, as shown in Fig. 4, the outer peripheral front panel 220 of the large shielding door 100 moves in the Y-axis direction toward the shielding receiving frame 12, pressing against multiple gaskets 14 and electrically connecting the outer peripheral front panel 220 and the shielding receiving frame 12. This prevents leakage of electromagnetic waves and blocks the propagation of electromagnetic waves between the shielding building 10 and the outside world.

In FIG. 3, the outer peripheral front panel 220 provided on the outer periphery of the central shielding panel 132 corresponds to the shield receiving frame 12 provided on the outer periphery of the entrance of the shield building 10. Therefore, the outer peripheral front panel 220 extends in the Z-axis direction, which is the front-to-back direction of the drawing, and is integrally connected to the outer peripheral front panel 220 of the upper leakage prevention mechanism 114 and the lower leakage prevention mechanism 118 shown in FIG. 1. A large number of air cylinders 280 for moving the outer peripheral front panel 220 in the Y-axis direction toward the shield receiving frame 12 are provided on the large shield door 100. In this embodiment, two air cylinders 280 are provided in parallel, and a large number of sets of the parallel air cylinders 280 are arranged in the Z-axis direction along the outer peripheral front panel 220. Compressed air is supplied to the multiple air cylinders 280 from a commonly used compressed air supply device 238 via air pipes 236. The multiple air cylinders 280 are each fixed to the large shield door 100 by a fixing mechanism 284. Therefore, when the large shield door 100 moves up, down, left, or right relative to the entrance of the shield building 10 to open the entrance, the air cylinder 280 and the numerous springs 290 described below move together with the large shield door 100, and when it returns to a position that closes the entrance as shown in Figure 3, it returns together with the large shield door 100 to the position shown in Figure 3.

A number of springs 290 are provided on either side of the air cylinders 280 arranged in parallel, and each is fixed to the large shield door 100 by a fixing mechanism 292. The operation will be explained below with reference to FIG. 4. Each spring 290 generates a pulling force in a direction that moves the outer peripheral front panel 220 away from the gasket 14 with a certain force, as shown by the arrow F1. On the other hand, each air cylinder 280 generates a force in a direction that moves the outer peripheral front panel 220 toward the gasket 14 according to the compressed air from the compressed air supply device 238. This force is shown by the arrow F2. In this embodiment, the air cylinders 280 are evenly arranged between three springs 290 arranged in parallel at equal intervals. The pressure of each air cylinder 280 is transmitted to the outer peripheral front panel 220 via the pressure plate 270 and the evenly arranged elastic bodies 272. When the pressure of the compressed air supplied from the compressed air supply device 238 increases, it moves the outer peripheral front panel 220 toward the shield receiving frame 12 against the force F1 of multiple evenly arranged springs 290. This operation is described in detail below.

An internal connection mechanism 160 is provided to prevent electromagnetic wave leakage between the peripheral front panel 220 and the central shielding panel 132. This internal connection mechanism 160 extends in the Z-axis direction, which is the front-to-back direction of the drawing, and is provided so as to surround the entire outer periphery of the central shielding panel 132. The internal connection mechanism 160 includes a side panel 222 that is connected to the end of the peripheral front panel 220 and extends away from the shield receiving frame 12, a folded panel 224 that is connected to the folded end 226, which is the end of the side panel 222, and extends parallel to the side panel 222 toward the shield receiving frame 12, and a central side panel 134 described below. The central side panel 134 is provided around the entire outer periphery of the central shielding panel 132 and extends away from the shield receiving frame 12 at a position sandwiched between the side panel 222 and the folded panel 224.

5.4 Description of the electromagnetic wave leakage prevention operation of the leakage prevention mechanism 110 5.4.1 Outline of the electromagnetic wave leakage prevention operation of the leakage prevention mechanism 110 Fig. 4 shows the positional relationship in a state in which leakage of electromagnetic waves from the entrance of the shielded building 10 is prevented. However, as described above, Fig. 3 shows a cross section of the left leakage prevention mechanism 116 in Fig. 1, and Fig. 4 shows a cross section of the right leakage prevention mechanism 112, so the positional relationship between the leakage prevention mechanism 110 and the central shielding panel 132 is reversed between Fig. 3 and Fig. 4.

In FIG. 4, when compressed air is supplied from the compressed air supply device 238 to the multiple air cylinders 280, the pressure of the compressed air causes the rods 282 of each air cylinder 280 to apply the force of arrow F2 to the outer peripheral front panel 220 via the pressure plate 270 and elastic body 272. Meanwhile, the force of each spring 290 shown by arrow F1 acts on the outer peripheral front panel 220. When the total force of the rods 282 of the multiple air cylinders 280 becomes greater than the total force of the multiple springs 290, the outer peripheral front panel 220 moves toward the shield receiving frame 12, and a force obtained by dividing the total force generated by the multiple air cylinders 280 and the total force of the multiple springs 290 by the number of elastic bodies 272 acts as a pressure on each gasket 14. Each gasket 14 has the characteristics of an elastic body, and each gasket 14 deforms to a state corresponding to the pressure from the outer peripheral front panel 220, and the positional relationship between the outer peripheral front panel 220 and the shield receiving frame 12 is determined. In this state, the outer peripheral front panel 220 and the shield receiving frame 12 are electrically connected and maintained in this state.

Next, the operation of the internal connection mechanism 160 will be described. When the outer peripheral front panel 220 moves in the direction of the shield receiving frame 12, which is the Y-axis direction, the side panel 222, the folded panel 224, and the gasket 152, gasket 142, and gasket 144 move in the direction of the shield receiving frame 12. As a result, the end of the central side panel 134 fixed to the central shielding panel 132 is electrically connected to the gasket 152, and the end of the central side panel 134 and the end of the side panel 222 are electrically connected via the gasket 152. In addition, the central side panel 134 is always electrically connected to the folded panel 224 and the side panel 222 via the gaskets 142 and 144.

5.4.2 Explanation of the electromagnetic wave leakage prevention action and its effect of the leakage prevention mechanism 110 (1) Explanation of the action and effect of the air cylinder 280 and the spring 290 As shown in Fig. 3 and Fig. 4, the springs 290 and the air cylinders 280 are arranged at regular intervals and evenly along the front-to-back direction of the drawing, which is the Z-axis direction of the shield receiving frame 12. Furthermore, the springs 290 and the air cylinders 280 are arranged alternately and evenly in the width direction of the shield receiving frame 12. Furthermore, the force of the springs 290 and the force of the air cylinders 280 act in opposite directions. With this arrangement, a pressure based on the difference between the force of the springs 290 and the force of the air cylinders 280 presses the multiple gaskets 14, which are elastic bodies. A force much smaller than the magnitude of the force of the air cylinders 280 and the springs 290 has a very small effect on control accuracy and can be ignored. Furthermore, compressed air is sent to each air cylinder 280 from a common compressed air supply device 238. The imbalance in air pressure sent to the air cylinders 280 can be ignored. Therefore, by controlling the characteristics of the springs 290, the pressure on the outer peripheral front panel 220 provided around the entire periphery of the central shielding panel 132 can be made almost uniform. Also, the time delay in supplying compressed air to each air cylinder 280 does not pose a problem.

Because the large shielded door 100 is very large, it is often necessary to manufacture the door by a method such as welding. Because the large shielded door 100 is very large, it is often difficult to improve manufacturing precision. Because the large shielded door 100 is very large, the dimensional relationship also changes due to temperature changes. As described above, the relationship between the outer peripheral front panel 220 and the shield receiving frame 12 is determined by the pressure applied to the gasket 14 and the elastic characteristics of the gasket 14, so even though the outer peripheral front panel 220 is large and extends around the entire circumference of the central shielding panel 132, the spacing between the shield receiving frame 12 and the outer peripheral front panel 220 can be made almost uniform by the above-mentioned method.

As mentioned above, in Japan, it is desirable to always consider measures against earthquakes. In particular, since the large shielded door 100 that is the subject of the present invention is very large compared to conventional shielded doors, the amplitude of the out-of-plane vibration of the large shielded door 100 is larger than that of conventional ones. In this embodiment, as described above, the pressure of the outer peripheral front panel 220 against the gasket 14 is determined by the difference in force between the moving mechanism 280 and the spring 290. It is relatively easy to make the resonance frequency of the spring 290 different from the vibration frequency of the earthquake. Therefore, it is relatively easy to maintain the pressure of the outer peripheral front panel 220 against the gasket 14 at a predetermined pressure against earthquake vibrations. Therefore, a stable electromagnetic wave leakage prevention effect can be obtained even against earthquakes. In addition, in the internal connection mechanism 160, the electromagnetic wave leakage between the central side panel 134 is prevented by sandwiching it between the parallel side panel 222 and the folded panel 224. Therefore, a stable electromagnetic wave leakage prevention effect can be obtained against earthquake vibrations.

In this embodiment, the outer peripheral front panel 220 is electrically connected to the shield receiving frame 12 via multiple gaskets 14. As described above, each gasket 14 is subjected to a substantially uniform pressure, so the electrical connection between each gasket 14 and the outer peripheral front panel 220 is stable. This provides a good electromagnetic wave leakage prevention effect. In particular, electromagnetic waves with a frequency of about 1 GHz tend to bend around the surroundings more easily than electromagnetic waves with a frequency of 50 GHz, which makes it easier for the electromagnetic waves to leak. Even in this frequency band, an excellent leakage prevention effect can be obtained.

In this embodiment, a gasket 14 is used that is made by overlapping a fine wire mesh multiple times, for example five times or more. Two or more of these gaskets 14 are arranged in parallel. By arranging multiple or even more gaskets 14 in parallel, the synergistic effect of these can be achieved to provide a significant leak prevention effect even against electromagnetic waves in the frequency band of about 1 GHz.

(2) Description of the action and effect of the internal connection mechanism 160 The internal connection mechanism 160 has two leakage cutoff parts. One is the first leakage cutoff part 140, and the other is the second leakage cutoff part 150. The first leakage cutoff part 140 and the second leakage cutoff part 150 use gaskets 142, 144, and 152. It is preferable to select different types of gaskets depending on the situation. For example, the gasket 152 used in the second leakage cutoff part 150 is made by overlapping a metal net made by weaving metal wires as described above, and the gaskets 142 and 144 used in the other first leakage cutoff part 140 use finger-type gaskets of a different type from the gasket 152. By combining different types of gaskets in this way, it is possible to achieve the effect of preventing leakage against a wide range of electromagnetic waves, from electromagnetic waves below 1 GHz to electromagnetic waves above 1 GHz, for example, about 50 GHz.

6. Description of the manufacturing method of the central shielding panel 132, the leakage prevention mechanism 110, etc. As described above, the large shielding door 100, which is the subject of the invention, is very large compared to conventional shielding doors. Therefore, the conventional method of completing the door in a factory and transporting it to the installation site cannot be applied. Since the large shielding door 100 is very large, it is often preferable to manufacture the central shielding panel 132, the peripheral front panel 220, etc. in parts and complete them at the installation site. The embodiment shown in FIG. 5 is a method of completing the leakage prevention mechanism 110 by dividing the leakage prevention mechanism 110 into a number of unit leakage prevention mechanisms 111 and connecting the unit leakage prevention mechanisms 111 to each other by welding such as seam welding and mechanical connection methods. With this method, the unit leakage prevention mechanisms 111 can be manufactured in a factory and the leakage prevention mechanism 110 can be completed at the installation site. It is easy to manufacture in a factory and easy to transport. In addition, by using the embodiment described using Figures 3 and 4, there is an advantage that high manufacturing precision is not required to obtain the electromagnetic wave leakage effect, and it is possible to adopt a method of completing the installation at the installation site.

The embodiment shown in FIG. 5 will be described in detail. The right side leakage prevention mechanism 112, the upper side leakage prevention mechanism 114, the left side leakage prevention mechanism 116, and the lower side leakage prevention mechanism 118 constituting the leakage prevention mechanism 110 are divided into a number of unit leakage prevention mechanisms 111, and the multiple unit leakage prevention mechanisms 111 are connected to each other by welding and mechanical connection methods to complete the leakage prevention mechanism 110. Here, part D1 of the upper side leakage prevention mechanism 114 will be described as a representative example. When part D1 is enlarged, it is composed of unit leakage prevention mechanisms 111N-1 and unit leakage prevention mechanisms 111N. The unit leakage prevention mechanisms 111N-1 and 111N have the same configuration and size. The unit leakage prevention mechanism 111N-1 has a unit outer peripheral front panel 221N-1 and a unit internal connection mechanism 161N-1. The springs 290 and air cylinders 280 described in Figures 3 and 4 are provided at equal intervals on the unit outer peripheral front panel 221N-1. Similarly, the unit leakage prevention mechanism 111N has a unit outer peripheral front panel 221N and a unit internal connection mechanism 161N, and the springs 290 and air cylinders 280 described in Figures 3 and 4 are provided at equal intervals on the unit outer peripheral front panel 221N. Note that the number and arrangement of the springs 290 and air cylinders 280 shown in Figure 5 are one example. The number and arrangement of the springs 290 and air cylinders 280 on the unit outer peripheral front panel 221N-1 and the unit outer peripheral front panel 221N are the same, but there may be fewer or more than in the state shown in Figure 5.

The unit leakage prevention mechanism 111N-1 and the unit leakage prevention mechanism 111N have the same configuration and shape, and can be manufactured in a factory, transported to the installation site, and connected to each other at the installation site. The unit leakage prevention mechanism 111N-1 and the unit leakage prevention mechanism 111N are composed of a metal plate part that prevents leakage of electromagnetic waves and a metal fixed frame part. The spring 290 and the moving mechanism 280 are installed in the metal fixed frame part. The metal fixed frame part can be easily connected by a mechanical connection method. The metal plate parts that prevent leakage of electromagnetic waves need to be connected to each other so that the electrical connection is maintained. In this embodiment, they are connected by seam welding, which will be described below. Seam welding makes it easy to connect, and also makes it easy to separate the connection parts. Furthermore, after being separated, they can be connected again by seam welding. This makes it possible to separate a part for maintenance, and then reconnect by seam welding after the maintenance is completed. This seam welding can completely block the propagation of electromagnetic waves.

The specific structure for fabricating the central shielding panel 132 on-site will be described with reference to Figure 6. The thickness of the metal plate of the central shielding panel 132 is, for example, about 2 mm or 3 mm. If one were to fabricate the central shielding panel 132 without dividing this metal plate, a very large building would be required. Not only that, but it would be difficult to transport it to the installation site, and in fact would be impossible to transport. Therefore, in this embodiment, the central shielding panel 132 is fabricated by mechanically connecting a large number of unit central shielding panels 128 together. Furthermore, despite the use of a mechanical connection method, an extremely good electrical connection is obtained that is the same as if the entire panel were made from a single plate.

As shown in FIG. 6, the central shielding panel 132 is made up of a number of unit central shielding panels 128. FIG. 6 shows an enlarged view of the structure of range D2, which is a portion of the central shielding panel 132. Each unit central shielding panel 128 is folded at both ends perpendicular to the surface of the central portion of the unit central shielding panel 128, forming connection portions 129 at both ends. The ends of each connection portion 129 are further folded at right angles to the surface of the connection portion 129 to form a folded portion 130. This folded portion 130 is shaped approximately parallel to the surface of the central portion of the unit central shielding panel 128.

At both ends of each unit central shielding panel 128, a bent portion 131 is formed at the connection between the connection portion 129 and the folded portion 130, and each bent portion 131 has a curved shape. As a result, when the unit central shielding panel 128 and the unit central shielding panel 128 are arranged close to each other so that their respective connection portions 129 face each other, the bent portions 131 of the adjacent unit central shielding panels 128 are arranged close to each other, and each bent portion 131 has a curved shape, so that a space is formed by this curvature. A shield metal 135 made of a metal rod of copper or copper alloy is arranged in this space, and the shield metal 135 is pressed against the center of both bent portions 131 arranged close to each other with a pressing metal plate 136, so that the shield metal 135 is deformed by the pressure, enters the gap between both bent portions 131, and adheres closely to the bent portions 131 of both 128. Any material with excellent electrical conductivity and ductility can be used as the shield metal 135. As mentioned above, copper and copper alloys are suitable materials for use as shield metal 135.

In order to press the shield metal 135 with a strong force against the center of both bent portions 131, both ends of the pressing metal plate 136 are pressed and fixed to the respective folded portions 130 of the adjacent unit central shielding panels 128 by fasteners 137. As a result, the shield metal 135 is in a deformed state and adheres closely to the bent portions 131 of the adjacent unit central shielding panels 128, and a mutual pressing force, in other words a tension-like force, is constantly acting between both bent portions 131, the shield metal 135, and the pressing metal plate 136.

Therefore, even if thermal expansion or vibration occurs, the electrical connection between the adjacent unit central shielding panels 128 and the shield metal 135 is stably maintained. In addition, even if there are manufacturing errors in the connection portion 129, the bent portion 131, and the folded portion 130, the deformation of the shield metal 135 has the great effect of absorbing these errors.

In addition, the central shielding panel 132 can be completed by connecting the unit central shielding panels 128 one by one. In other words, since the central shielding panel 132 is very large, it cannot be completed all at once. The unit central shielding panels 128 are connected one by one using the above-mentioned method. One side of the unit central shielding panel 128 is connected using the above-mentioned method, and then the other side is connected. During this connection work, vibrations and stress fluctuations are applied to the already connected parts. However, as described above, a force such as a tension force that pushes against each other acts on the connected parts, and the bent parts 131 and the pressing metal plate 136 are in close contact with each other. This has the effect of being able to fully withstand the vibrations and the like that accompany the connection work.

In FIG. 6, the unit central shielding panel 128, the connection portion 129, the bent portion 131, and the folded portion 130 each extend long in the front-to-back direction of the paper of FIG. 6. Similarly, the shield metal 135 and the pressing metal plate 136 also extend long in the front-to-back direction of the paper of FIG. 6. Therefore, a large number of fasteners 137 for pressing the pressing metal plate 136 against the folded portion 130 are provided at predetermined intervals along an axis extending in the front-to-back direction of the paper of FIG. 6. By mechanically connecting a large number of unit central shielding panels 128 using the structure of FIG. 6 to form the central shielding panel 132, the large number of unit central shielding panels 128 can maintain a good electrical connection with each other, and good electromagnetic wave shielding characteristics can be obtained.

Figure 7 is an enlarged view of the second leakage blocking section 150. In order to connect the side panel 222 and the folded panel 224, for example, a connection section 225 is provided at the end of the folded panel 224, and the gasket 152 or the gasket 142 or gasket 144 shown in Figure 3 is sandwiched between the connection section 225 and the side panel 222 mechanically. For example, when fitting the gasket 152, the gasket 142, or the gasket 144, the side panel 222 and the folded panel 224 are mechanically detachable with a fastener 228 using a screw and a nut as shown in Figure 7, which greatly improves workability. Maintenance is also easy. Note that the gasket 152 blocks the propagation of electromagnetic waves to the connection section between the side panel 222 and the connection section 225, so that leakage of electromagnetic waves can be prevented without welding the side panel 222 and the connection section 225.

The above describes examples of the present invention, but the invention is not limited to these.

10: Shield building 12: Shield receiving frame 14: Gasket 20: Receiving frame fixing mechanism 100: Large shield door 110: Leakage prevention mechanism 112: Right side leakage prevention mechanism 114: Upper side leakage prevention mechanism 116: Left side leakage prevention mechanism 118: Lower side leakage prevention mechanism 128: Unit central shielding panel 129: Connection part 130: Folded part 131: Bending part 132: Central shielding panel 134: Central side panel 140: First leakage interruption part 142: Gasket 144: Gasket 150: Second leakage interruption part 152: Gasket 160: Internal connection mechanism 161: Unit internal connection mechanism 220: Peripheral front panel 221: Unit peripheral front panel 224: Folded panel 225: Connection part 226: Folded end 228: Fixing device 236: Air pipe 238: Compressed air supply device 270: Pressurizing plate 272: Elastic body 280: Air cylinder 282: Rod 284: Fixing mechanism 290: Spring 292: Fixing mechanism

Claims (8)

A large shielded door with an electromagnetic wave shielding structure that is installed at the entrance of a shielded building with an electromagnetic wave shielding function,
The height direction of the shield building is defined as the Z-axis of a rectangular coordinate system, the direction from the entrance side of the shield building to the opposite side of the entrance side of the shield building is defined as the Y-axis of the rectangular coordinate system, and the direction from left to right when looking from the entrance side of the shield building to the opposite side of the entrance is defined as the X-axis of the rectangular coordinate system.
the large shielding door has a central shielding panel for shielding electromagnetic waves provided along an X-Z plane, a leakage prevention mechanism having an outer peripheral front panel provided along the X-Z plane to surround the outer periphery of the central shielding panel for preventing leakage of electromagnetic waves, and a number of moving mechanisms for moving the outer peripheral front panel of the leakage prevention mechanism in the Y-axis direction;
A large shielded door with an electromagnetic wave shielding structure, characterized in that the outer peripheral front panel is moved in the Y-axis direction by the multiple moving mechanisms, and the outer peripheral front panel is brought into close contact with the outer periphery of the entrance of the shielded building, thereby preventing leakage of electromagnetic waves. In the large-sized shielded door having the electromagnetic wave shielding structure according to claim 1,
A shield receiving frame is provided along the outer periphery of the entrance of the shield building,
The shield receiving frame is provided with a plurality of first gaskets made of metal,
The outer peripheral front panel of the leakage prevention mechanism is made of a metal plate,
The outer peripheral front panel is provided at a position facing the shield receiving frame of the shield building when the large shield door is closing the entrance of the shield building,
The large shield door has an internal connection mechanism for electrically connecting the outer peripheral front panel and the central shielding panel,
When the leakage prevention mechanism is in a state of preventing leakage of electromagnetic waves at the entrance and exit of the shielded building, the outer peripheral front panel is moved in the Y-axis direction by the multiple moving mechanisms to press the multiple first gaskets provided on the shield receiving frame, and the outer peripheral front panel is electrically connected to the shield receiving frame.
A large shielded door equipped with an electromagnetic wave shielding structure characterized by: In the large-sized shielded door having the electromagnetic wave shielding structure according to claim 2,
the movement mechanism includes a number of air cylinders arranged at predetermined intervals along the axial direction of the long and short sides of the leakage prevention mechanism, a number of springs arranged at predetermined intervals , and an air pipe that supplies compressed air to the number of air cylinders;
The force of each spring acts in a direction to move the outer peripheral front panel away from the shield receiving frame,
The multiple air cylinders operate in a direction to move the outer peripheral front panel closer to the shield receiving frame against the force of the multiple springs by the compressed air supplied through the air pipes, and the force of the multiple air cylinders becomes greater than the force of the multiple springs, so that the outer peripheral front panel is electrically connected to the shield receiving frame via the multiple first gaskets.
A large shielded door equipped with an electromagnetic wave shielding structure characterized by: In the large-sized shielded door having the electromagnetic wave shielding structure according to claim 3,
the leakage prevention mechanism for preventing leakage of electromagnetic waves provided on the outer periphery of the central shielding panel of the large shield door along the X-Z plane is composed of a number of unit leakage prevention mechanisms,
Each of the unit leakage prevention mechanisms includes a unit outer peripheral front panel, a plurality of the springs acting in a direction to move the unit outer peripheral front panel away from the shield receiving frame, and the air cylinder generating a force against the springs to move the unit outer peripheral front panel toward the shield receiving frame,
The unit peripheral front panels of the multiple unit leakage prevention mechanisms are connected to each other by seam welding to form the peripheral front panel.
A large shielded door equipped with an electromagnetic wave shielding structure characterized by: In a large-sized shielded door having the electromagnetic wave shielding structure according to claim 3 or 4,
The internal connection mechanism for electrically connecting the outer peripheral front panel and the central shielding panel includes a side panel that is mechanically connected to the outer peripheral front panel, extends in the Y-axis direction in the opposite direction to the shield receiving frame, and has a tip that forms a folded end;
A folded panel that is mechanically connected to the side panel at the folded end, which is the tip portion of the side panel, and extends parallel to the side panel toward the shield receiving frame;
A central side panel is connected to an end of the central shielding panel, is located between the side panel and the folded panel, and extends in a direction along the Y axis and in a direction opposite to the shield receiving frame,
a second gasket is provided on the inside of the folded end of the side panel, which is a mechanical connection between the side panel and the folded panel;
Further, a third gasket is provided between the side panel and the central side panel at a position shifted from the end of the side panel toward the peripheral front panel,
a fourth gasket is provided between the folded panel and the central side panel at a position shifted from the end of the side panel toward the peripheral front panel;
In a state in which the outer peripheral front panel and the shield receiving frame are electrically connected via the first gasket, an end portion of the central side panel is electrically connected to the inside of the end portion of the side panel via the second gasket, the side panel and the central side panel are further electrically connected via the third gasket, and the folded panel and the central side panel are electrically connected via a fourth gasket.
A large shielded door equipped with an electromagnetic wave shielding structure characterized by: A large shielded door with an electromagnetic shielding structure according to any one of claims 2 to 5, characterized in that each of the first gaskets is a rod-shaped metal net formed by overlapping multiple layers of metal nets made by weaving metal wires. A large-sized shielded door having the electromagnetic wave shielding structure according to any one of claims 1 to 6,
The central shielding panel is formed by connecting a plurality of unit central shielding panels to each other,
Each of the unit central shielding panels has both ends bent at right angles to the surface of the central portion of the unit central shielding panel to form a connection portion, and the ends of the connection portion are bent at right angles to form a folded portion, and a folded portion is formed between the connection portion and the folded portion,
The plurality of unit central shielding panels forming the central shielding panel are arranged such that the connection portions of the respective unit central shielding panels face each other, so that the folded portions of the unit central shielding panels are arranged close to each other;
The shield metal is pressed against the bent portions arranged close to each other by a pressing metal plate, and the pressing metal plate is fixed by a fastener.
This is a large shielded door equipped with an electromagnetic wave shielding structure characterized by the above. A large-sized shielded door having the electromagnetic wave shielding structure according to any one of claims 1 to 7,
The large shield door has a shape having a long side and a short side in the X-Z plane based on the X-axis and the Z-axis, the long side being 4 m or more, and the short side being 3 m or more.
Alternatively, the large shield door has an area of 12 square meters or more in the X-Z plane based on the X-axis and the Z-axis.
A large shielded door equipped with an electromagnetic wave shielding structure characterized by: