JPH0342719Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a door for an anechoic chamber used in an anechoic chamber that blocks external radio waves and absorbs internal radio waves.

[Conventional technology]

When attempting to measure a specific radio wave, it is necessary to exclude other unnecessary radio waves from the measurement location. To achieve this, an anechoic chamber creates a space that blocks unnecessary external radio waves and absorbs the radio waves generated inside to a level that does not interfere with measurements. For example, an anechoic chamber is
It is often used to measure radio waves (electromagnetic waves) generated by electrical and electronic equipment.

In general, this anechoic chamber 1 is constructed of a wall 2 that constitutes the anechoic chamber 1, as shown in FIG. 6 (plan cross-sectional view).
is composed of a metal outer wall 3 and a radio wave absorber 4 arranged on the inner surface side (indoor side) of this metal outer wall 3, and blocks interference radio waves from the outside by the metal outer wall 3.
The structure is such that the inside of the anechoic chamber 1 is made electromagnetically quiet by absorbing the radio waves generated inside by the radio wave absorber 4. The metal outer wall 3 may be replaced with metal foil or the like. Further, the radio wave absorber 4 has an uneven surface in order to enhance the radio wave absorption effect.

6 is a conventional door for such an electromagnetic darkroom 1. Reference numeral 5 in FIG. This door 5, like a general door, is designed to enable opening and closing of the opening 6 (entrance/exit) of the wall 2 constituting the anechoic chamber 1.
Its vertical and horizontal dimensions are formed to be almost the same as the opening 6, and when it is in the closed state, it is configured to integrate with the wall 2 and close the opening 6. Also, like the wall 2, this door 5 has an outer surface made of a metal plate 5a, and an inner surface made of a radio wave absorber 4 having an uneven surface. Moreover, the metal outer wall 3 and the metal plate 5
As shown in FIG. 7, spring contacts 7a and 7b made of beryllium alloy or the like are used to ensure an electromagnetic wave shielding effect in the door 5 by electrically contacting each other when the door 5 is closed, as shown in FIG. is provided.

[Problem that the invention attempts to solve]

By the way, the above conventional door 5 has a structure similar to that of the wall 2, so that this door 5 can also block unnecessary radio waves from the outside and absorb radio waves generated inside. There were some problems as follows.

That is, as mentioned above, the door 5 is considerably thicker (for example, 50 cm thick) than a general door in order to have a structure that can obtain the effect of absorbing radio waves, similar to the wall 2. As in, the wall 2
If the structure is such that the opening 6 is closed integrally with the opening 6, there is a risk that the free end side tip of the radio wave absorber 4 may graze the opening 6, as shown by the chain line in FIG. Therefore, it is necessary to take measures to avoid this, and there are restrictions on manufacturing and installation.

Furthermore, in order to prevent the tip of the radio wave absorber 4 from grazing the opening 6 when the door 5 is opened and closed, the width of the radio wave absorber 4 must be made shorter at its free end than the opening 6. , as shown in the figure, there is a part where the radio wave absorber 4 is not formed between it and the wall 2, and it is difficult to ensure radio wave absorption in this part, and there is a concern that the linear exposed metal surface may act as an antenna. .

Furthermore, the radio wave absorber 4 formed on the door 5
Because the doors face the aisle when opened, they can be easily damaged by contact with a human body, etc.

This idea was made in view of the above circumstances.
As a door for an anechoic chamber, it can completely block unnecessary radio waves from the outside and absorb radio waves generated internally.It is also easy to install and maintains its structure for a long time to block and absorb radio waves. The object of the present invention is to provide a door for an anechoic chamber that can maintain its function.

[Means for solving problems]

In this invention, a radio wave absorber is arranged on the inner surface of the metal outer wall to open and close an opening formed in the wall that constitutes the radio anechoic chamber. and a radio wave absorber provided in the door outer panel and having unevenness facing toward the open surface, and the door outer panel is configured such that the entire door outer panel is located more than the opening. It is formed to have a large size and is provided at a different level from the wall so that its open surface faces the opening and is superimposed on the wall through the contact portion, and furthermore, a protective plate having radio wave transparency is provided on the open surface. It is characterized in that it is provided in a form that closes the release surface, and the contact portion further includes:
A plurality of first protruding plates protruding outward from the metal outer wall and a plurality of second protruding plates protruding from the door outer plate toward the wall body, respectively. A buffer member formed so as to mesh with each other alternately, and having conductivity in each of a first groove formed between the first protruding plates and a second groove formed between the second protruding plates. This includes those configured by fitting.

[Effect]

By employing a structure in which the door that opens and closes the opening in the wall closes the wall from the outside, the door is not subject to dimensional restrictions due to the opening. Therefore, the door can be made sufficiently large for the opening, and the radio wave absorber can cover the opening without any gaps.

Furthermore, the radio wave absorber provided on the door is protected from human contact by the protective plate, and will not be damaged over a long period of time.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows one embodiment of the present invention, and the reference numeral 10 is a door for an anechoic chamber (hereinafter abbreviated as "door") according to the present invention. Furthermore, the reference numeral 2 indicates a wall constituting the anechoic chamber 1, and this wall 2 is similar to the conventional one. That is, this wall body 2 includes a metal outer wall 3 and a radio wave absorber 4 arranged on the inner surface side (indoor side) of the metal outer wall 3, and shields external radio waves from the metal outer wall 3, and also shields the metal outer wall 3 from internal radio waves. The structure is such that the generated radio waves are absorbed by the radio wave absorber 4. The radio wave absorber 4 has a surface facing into the radio wave anechoic chamber 1 that is formed to have an uneven surface so as to enhance the radio wave absorption effect. In this embodiment, the radio wave absorber 4 is made of urethane.

The door 10 that opens and closes the opening 6 formed in the wall 2 as an entrance/exit of the anechoic chamber 1 includes a door outer panel 10a formed in a box shape with an open surface 11 on one side made of a metal plate, and the door. The electromagnetic wave absorber 4 is provided in the outer plate 10a and has a surface facing the open surface 11 that is uneven. Its width and height are slightly larger than the opening 6, and it is provided at a different level from the wall 2 so that its end overlaps the outside of the wall 2 via the contact portion 12. It has become a common thing.

The contact portion 12 has a structure as shown on an enlarged scale in FIG. That is, three protruding plates (first protruding plates) 14 protruding outward are formed in parallel along the opening 6 at the edge of the opening 6 of the metal outer wall 3 constituting the wall body 2. On the other hand, two parallel protruding plates (second protruding plates) 16 that protrude toward the wall 2 are installed in a portion of the door outer panel 10a that is part of the door 10 that slightly wraps around the open surface 11. , these second protruding plates 16 are formed so as to alternately engage with the first protruding plates 14 when the door is closed, and furthermore, grooves (first grooves) are formed between the first protruding plates 14. A conductive buffer member 18 is provided in a groove (second groove) 17 formed between the inside of the buffer member 15 and the second protrusion plate 16.
It is constructed by fitting each of them.
As shown in FIG. 3, the buffer member 18 is made of elastic foam rubber 19 with a metal mesh 2 on the outer peripheral surface.
It is configured by surrounding it with 0.

Further, the open surface 11 of the door outer panel 10a has a radio wave absorber 4 provided inside the door outer panel 10a.
A protective plate 22 is provided in a form that encloses the opening surface 11 and closes the opening surface 11 (see FIG. 1). That is,
This protective plate 22 is the door 10 in the anechoic chamber 1.
It is in a state that it constitutes the inner surface of. Protective plate 2
2 is made of a material that is lightweight, has a certain degree of strength, and has good radio wave transparency with little reflection of radio waves. In this embodiment, this protective plate 1
1 is made of acrylic. In addition, in FIG. 1, reference numeral 25 indicates a hinge of the door 10, and reference numeral 2
6 is an opening/closing lever. Further, the door 10 has a fourth
It may be opened and closed 90 degrees as shown in the figure, or the hinge 2
5, it can be opened and closed 180 degrees as shown in Fig. 5.

Next, the anechoic chamber door 1 configured as described above is
The effect of 0 will be explained.

Of the radio waves directed toward the anechoic chamber 1 from outside the anechoic chamber 1, the radio waves that reach the door 10 are shielded by the metal door outer plate 10a and cannot enter the anechoic chamber 1. The door outer plate 10a is in contact with the metal outer wall 3 of the wall body 2 via the contact portion 12, and by configuring the contact portion 12 as described above, the contact between the door outer plate 10a and the metal outer wall 3 is prevented. Not only can the area be increased, but the multi-contact structure can eliminate contact defects. Thereby, the electrical connectivity between the door outer plate 10a and the metal outer wall 3 can be improved, and the shielding performance of the door 10 can be improved. Furthermore, compared to conventional spring contacts made of beryllium alloy, they are less expensive, more difficult to break, and extremely easy to replace.

On the other hand, among the radio waves generated inside the anechoic chamber 1, the radio waves directed toward the door 10 first reach the protection plate 22 forming the inner surface of the door 10.
As mentioned above, since it has good radio wave transparency, the radio waves pass through this protection plate 22,
It reaches the radio wave absorber 4 and is absorbed. Therefore, radio waves generated inside cannot penetrate into the anechoic chamber 1 through this door 10.

Here, the door 10 is configured to have a longer width and height than the opening 6 of the wall 2.
Since the door 10 is installed at different levels, even if the door 10 is thick, there is no need to worry about interference with the wall 2 during opening and closing operations. As a result, the radio wave absorber 4 in the door 10
can be made to have a width (height) sufficient to close the opening 6, and a gap can be created between both radio wave absorbers 4 at the boundary between the wall 2 and the door 10. do not have. Incidentally, the gap here refers to the gap in the projected state when looking from the inside of the anechoic chamber 1 to the outside (from the left side to the right side of the wall body 2 in FIG. 1).

Thereby, the area around the opening 6 can be completely covered with the radio wave absorber 4, and the radio waves generated inside the anechoic chamber 1 can be completely absorbed.
Moreover, since the protection plate 22 is provided on the outside of the radio wave absorber 4 provided on the door 10, the radio wave absorber 4 can be protected from direct human contact, and the door is moved frequently. This prevents the radio wave absorber 4 from being peeled off or damaged, and the radio wave absorption performance of the door 10 can be maintained for a long period of time.

[Effect of idea]

As explained above, the present invention provides a door for an anechoic chamber that opens and closes an opening formed in a wall that constitutes an anechoic chamber by arranging a radio wave absorber on the inner surface of a metal outer wall.
A door outer panel formed in a box shape with one side being an open surface made of a metal plate, and a radio wave absorber provided in the door outer panel and forming unevenness facing the open surface, the above-mentioned The door outer plate is formed as a whole to be larger than the opening, and is provided at a different level from the wall so that its open surface faces the opening and overlaps the wall via the contact portion, and , since a radio wave transparent protection plate is provided on the open surface of the door outer panel in a form that covers the open surface, it is possible to completely cover the area around the opening with the radio wave absorber without any gaps; Complete radio wave blocking properties can be achieved. Moreover, the protective plate prevents the radio wave absorber from being damaged by exposure to human contact, allowing it to maintain its original radio wave absorption effect over a long period of time. Since there is no need to do any additional work, production and assembly can be easily performed, resulting in excellent effects such as cost reduction.

[Brief explanation of drawings]

Fig. 1 is a plan sectional view showing an anechoic chamber door together with a wall forming the anechoic chamber according to an embodiment of the present invention, and Fig. 2 is an enlarged plan sectional view showing the structure of a contact portion according to an embodiment. FIG. 3 is a perspective view showing a buffer member constituting a contact portion according to one embodiment, and FIGS. FIG. 6 is a sectional plan view showing a conventional door for an anechoic chamber, and FIG. 7 is a sectional plan view showing the structure of a contact portion in the conventional door for an anechoic chamber. 1... Radio anechoic chamber, 2... Wall, 3... Metal outer wall, 4... Radio wave absorber, 6... Opening, 10...
Anechoic chamber door, 10a...Door outer plate, 11...
Release surface, 12... Contact portion, 14... First protruding plate, 15... First groove, 16... Second protruding plate, 17... Second groove, 18... Buffer member ,2
2...Protection board.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) In a door for an anechoic chamber that opens and closes an opening formed in a wall that constitutes an anechoic chamber by arranging a radio wave absorber on the inner surface of a metal outer wall, one side is covered with a metal plate. A door outer panel formed in a box shape with an open surface, and a radio wave absorber provided within the door outer panel and forming unevenness facing the open surface,
The door outer plate is formed to be larger than the opening as a whole, and is positioned at a different level from the wall so that its open surface faces the opening and overlaps the wall via the contact portion. 1. A door for a radio anechoic chamber, characterized in that the opening surface is provided with a radio wave transparent protection plate that covers the opening surface. The contact portion includes a plurality of first protruding plates protruding outward from the outer wall of the metal painting, and a plurality of second protruding plates protruding from the door outer plate toward the wall. and a first groove formed between the first protruding plates and a second groove formed between the second protruding plates. The door for an anechoic chamber according to claim 1, wherein each door is fitted with a conductive buffer member.