JP5120937B2 - Anechoic chamber - Google Patents

Description

  The present invention relates to an anechoic chamber used for electromagnetic interference measurement of various electric and electronic devices, and more particularly to an anechoic chamber having a vertical conductive surface used for conducting interference measurement.

  Various electromagnetic phenomena exist in an environment where various electric and electronic devices, devices, systems, and the like are installed. An electromagnetic phenomenon that causes a decrease in the performance of a device or the like or causes a malfunction is called electromagnetic interference. Electromagnetic interference is generally classified into the following two types according to the form of coupling between a device that generates an interference wave and a device that is damaged.

  One is a conduction disturbance, in which electromagnetic energy of an interference wave is transmitted mainly through a conductor such as a power line or a signal line, and enters other devices to cause interference. The other is radiation interference, in which electromagnetic energy of an interference wave is radiated in the form of electromagnetic waves and propagates through space and interferes with other devices.

  These electromagnetic interference measurements have different measurement methods and measurement environment regulations depending on their types.

  In general, the measurement of conduction disturbance is performed in a shield room in which the entire room is electromagnetically shielded using a shield material made of a conductive material. In addition, the measurement of radiation interference is performed in an anechoic chamber (generally referred to as a “semi-anechoic chamber”) in which the inner wall excluding the floor surface of the shield room is covered with a radio wave absorber. This is often performed in an “anechoic chamber”.

  However, in the measurement of electromagnetic interference, the construction of a separate shield room for conducted interference measurement and an anechoic chamber for radiation interference measurement requires a large amount of capital investment, which is an economic burden on the installer. .

  Even if both shielded room and anechoic chamber are constructed, when conducting and radiating disturbances of the same object to be measured (hereinafter referred to as “EUT”) are measured, the measurement location is moved and setting is performed again. Because it is necessary, work efficiency is very bad.

  In the measurement of conduction interference, the distance between the conductive plate serving as the reference plane and the EUT is specified, and the space between the reference plane and the EUT has some electromagnetic influence including the conductor and the electromagnetic wave absorber. What you give cannot be installed.

  On the other hand, since it is possible to measure conduction interference in an anechoic chamber if the reference plane is satisfied, it is configured as a conductive floor surface in the anechoic chamber (a reference surface that can be regarded as the same potential as the ground). Hereinafter referred to as “the ground plane”), and a conductive plate standing perpendicular to the ground plane is grounded to the ground plane, and the reference plane (the surface facing the EUT is hereinafter referred to as the “conductive plane”). By using it, the measurement is performed in an anechoic chamber.

  Here, “grounding” refers to realizing not only electrical continuity but also a uniform equipotential state that satisfies the grounding regulations of FCC in the United States, VCCI in Japan, and the like.

  The conductive plate must be carried into the anechoic chamber only when conducting disturbances are measured, and otherwise removed so as not to affect other electromagnetic interference measurements. A vertical conductive surface partition for use is disclosed in Patent Document 1.

Japanese Patent Laid-Open No. 08-46382

  Hereinafter, in order to distinguish from a general name or a conductive plate used as a component, a configuration including a conductive plate according to the present invention and a mechanism associated therewith is referred to as a “vertical ground plane”.

  Note that the term “vertical” as used in the present invention includes a slope permitted by a measurement standard defined by FCC in the United States, VCCI in Japan, etc., and the allowable range may differ depending on the standard to be applied.

  Conventionally, the conductive plate has been taken in and out of the anechoic chamber carry-in / out port every time conducted disturbance measurement and radiation disturbance measurement are performed. However, there is a problem in that it is not easy to carry in / out a conductive plate, which is a relatively large structure, to be installed in an anechoic chamber.

  In addition, since the entrance / exit of the anechoic chamber also needs to have a size corresponding to the size of the conductive plate, a large opening must be provided. However, the opening of the anechoic chamber must be tightly shielded so as not to affect the propagation characteristics of the measurement. The larger the opening, the more difficult it is to shield and the cost of the countermeasure increases. There is a problem of becoming.

  In order to deal with the above two problems, a method of providing a storage portion for a conductive plate in the inside of an anechoic chamber, more specifically, on a wall surface on which an electromagnetic wave absorber is installed is conceivable. In addition, since the area of the anechoic chamber itself increases, there remains a problem that the cost required for construction becomes high.

  The present invention has been made to solve the problems of the prior art. The purpose of the present invention is to facilitate the installation and removal of a vertical ground plane when measuring electromagnetic interference, and to relate to building construction costs and shield processing. The object is to provide an anechoic chamber that can reduce the cost of countermeasures.

According to the present invention, there is an anechoic chamber for measuring electromagnetic interference, which includes a conductive plate serving as a reference surface, means for standing the conductive plate perpendicular to the ground, and a storage section provided under the floor. and, all parts of the means for erecting the conductive plate and the vertically anechoic chamber is obtained, characterized in that housed in the housing portion.
That is, according to the present invention, there is an anechoic chamber for measuring electromagnetic interference, a conductive plate serving as a reference surface, means for standing the conductive plate perpendicular to the ground, and a storage provided under the floor. A lifting device capable of raising and lowering the conductive plate, wherein the means for vertically erecting the conductive plate is a part of or all of the lifting device and the whole of the conductive plate. Thus, an anechoic chamber characterized in that the anechoic chamber is configured to be lowered below the floor when stowed while being vertically raised with respect to the floor and raised to the floor when used.
Further, according to the present invention, the conductive plate is formed by electrically and mechanically connecting a plurality of plate-like conductors, and by developing or housing the plate-like conductor, the conductive surface of the conductive plate. The above-described anechoic chamber can be obtained in which the dimensions of the anechoic chamber can be changed .
In addition, according to the present invention, it is possible to obtain the above-described anechoic chamber further including a mechanism for adjusting the position of the conductive plate with respect to the measurement target.
According to the present invention, it is possible to obtain the above-described anechoic chamber, wherein the mechanism for adjusting the position of the conductive plate is configured to be extendable and contractible.
Moreover, according to this invention, said electromagnetic wave anechoic chamber characterized by the top plate of the said raising / lowering apparatus becoming a cover plate of the said accommodating part is obtained.

  Conventionally, when measuring radiation interference in an anechoic chamber, the vertical ground plane was removed from the anechoic chamber and re-installed when measuring conducted interference. By storing it under the floor of the dark room, when it is not used, other measurements are not affected at all, and it is not necessary to carry in / out for each measurement, so workability is improved. In addition, since frequent loading / unloading is unnecessary, the opening size of the anechoic chamber's loading / unloading entrance can be kept small, and there is no need to increase the area of the building itself. Can be suppressed.

  The means for vertically raising the conductive plate can take various forms. For example, the conductive plate can be attached to a vertical column or carriage. As a vertical ground plane, the member where the conductive plate is placed behind the surface facing the EUT is within the dimensions of the conductive surface as viewed from the EUT, and its configuration is restricted unless it has a particular effect on the measurement environment. Will not receive.

  In the present invention, as a means for vertically erecting the conductive plate of the vertical ground plane, the conductive plate can be tilted by attaching the conductive plate to the lifting device stored in the storage unit, or using a folding mechanism or a hinge. Can be. Therefore, when used, the conductive plate is raised or vertically raised from the storage unit, and when stored, the conductive plate is lowered or laid down so that it is inclined or parallel, so that the height during storage is higher than that during use. Since it can be lowered, the storage part under the floor of the anechoic chamber can be shallowed, and the construction cost can be further reduced.

  In addition, depending on the size and shape of the EUT and the situation of the measurement location, it may be necessary to adjust the installation position of the vertical ground plane. Therefore, an extendable arm is attached as a means for moving the conductive plate of the vertical ground plane. It can also be configured to adjust the installation position by moving the plate itself. With such a configuration, even if there is a restriction on the movement of the vertical ground plane due to the position of the installable storage unit or incidental equipment, the installation position of the conductive plate itself and the angle facing the EUT can be adjusted. It becomes.

  According to the present invention, the conductive plate is formed by electrically and mechanically connecting a plurality of plate-like conductors, and the size of the conductive surface of the conductive plate is developed or accommodated by the plate-like conductors. An anechoic chamber characterized in that can be changed is obtained.

  In the vertical ground plane used for conducting disturbance measurement, the minimum size of the conductive surface necessary to satisfy the measurement standard is (width) 2 m × (height) 2 m. In the present invention, a plurality of plate-like conductors are electrically and mechanically connected to form a conductive plate, which is expanded or accommodated to change the size of the conductive surface, thereby providing a conductive surface necessary for measurement. In addition, the size of the housing can be made smaller than in the case of an integrally configured conductive plate by securing the size of the housing, and by reducing the size of the housing, the construction cost of the anechoic chamber can be further reduced. Further, by changing the configuration of the plate-like conductor, it is possible to easily cope with a large EUT.

  In the present invention, the vertical ground plane is moved up and down by a lifting device operated by a motor, air pressure, hydraulic pressure, or the like from the storage unit under the floor of the anechoic chamber to the floor, so that the weight is higher than when using the ramp. The present invention can also be applied to a case where it is difficult to provide a certain large vertical ground plane or an inclined path in the storage section, and the installation and storage work is further facilitated.

  In addition, it is possible to provide a storage shelf for storing members and tools used in the anechoic chamber as long as it is other than the conductive surface within the range that moves up and down by the lifting device, and workability can be improved without providing a new storage section. A good anechoic chamber can be realized. Further, by connecting the lifting device to the lower floor of the anechoic chamber building, workability is further improved by using it for loading and unloading materials and equipment.

  According to the present invention, when measuring electromagnetic interference in an anechoic chamber, it is easy to install and remove the vertical ground plane by constructing the vertical ground plane to be stored under the floor. It has become possible to provide an anechoic chamber that can reduce the cost of countermeasures.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
1 is a schematic side view showing a storage state of a vertical ground plane in an anechoic chamber according to Embodiment 1 of the present invention, and FIG. 2 is a schematic side view showing a usage state of the vertical ground plane in Embodiment 1 of an anechoic chamber according to the present invention. FIG.

  In FIG. 1, the vertical ground plane is stored in a storage unit 3 provided under the floor of the anechoic chamber, and the conductive plate 1 is held at the same height as the floor 4 of the anechoic chamber. Part of it.

  That is, the means for vertically raising the conductive plate 1 and the accompanying mechanism are accommodated under the floor of the anechoic chamber, and the conductive plate 1 becomes a part of the anechoic chamber floor 4 as a lid of the accommodating portion 3, so that the vertical ground plane A part of is stored.

  Moreover, according to the required intensity | strength of a flooring, the structural member which supports the electrically-conductive board 1 can be provided in the inside of the accommodating part 3, and the floor surface can also be reinforced.

  The electrical and mechanical connection methods related to grounding of the conductive plate 1 can use known means such as a connection with a metal hinge or a conductive mounting bracket, and the following embodiments also apply. It is the same.

  In FIG. 2, when the vertical ground plane in this embodiment is used, the conductive plate 1 grounded to the anechoic chamber floor surface 4 is attached to the column 11 and the support 2 is fitted into the fixing groove 21 of the column 11 and fixed. Thus, the conductive plate 1 can be erected vertically.

(Embodiment 2)
FIG. 3 is a schematic side view showing the storage state of the vertical ground plane in the second embodiment of the anechoic chamber according to the present invention, and FIG. 4 shows the folding mechanism of the vertical ground plane in FIG. 3 in the second embodiment of the anechoic chamber according to the present invention. It is the schematic to explain.

  In FIG. 3, the conductive plate 1 is attached to a support column 11, the support column 11 is attached to a carriage 51 having a caster 5 at the bottom as a moving means, and the rotation support point 12 is attached to the conductive plate 1 by a folding mechanism 22. Vertical standing, holding and tilting can be performed.

  The vertical ground plane deforms the conductive plate 1 into an inclined state and stores the conductive plate 1 in the storage unit 3 having the inclined path 31 so that the conductive plate 1 becomes a part of the lid of the storage unit 3. The conductive plate 1 and the anechoic chamber floor 4 are also grounded during storage so that the conductive surface of the conductive plate 1 functions as a part of the ground plane at the anechoic chamber floor 4. The opening part of the storage part 3 that cannot be covered with the conductive plate 1 will not affect the measurement if the storage part cover plate 33 configured to open and close the conductive material grounded to the anechoic chamber floor surface 4 is installed. can do.

  Also in the present embodiment, as in the first embodiment shown in FIG. 1, the conductive plate 1 has been described using an example in which it forms a part of the anechoic chamber floor surface 4, but the vertical ground including the conductive plate 1 is also used. It is also possible to store the entire plane in the storage unit 3 and cover the entire opening of the storage unit 3 with the storage unit cover plate 33.

  When the vertical ground plane in the present embodiment is installed at the time of use, a hook and a handle (both not shown) are attached to the carriage 51 and pulled up from the storage unit 3 along the ramp 31. After the vertical ground plane is moved to a predetermined position, the lever 221 is operated to raise the conductive plate 1 vertically and to ground the anechoic chamber floor 4. When storing, reverse the procedure.

  FIG. 4 illustrates an example of a specific configuration and operation of the folding mechanism 22.

  A fixing member A223 having a locking projection 224 is attached to one end of the attachment shaft 211 penetrating the support column 11, a lever 221 is attached to the other end of the attachment shaft 211, and the lever 221 is operated (tilted in the direction of the broken line arrow in the figure). Thus, the locking protrusion 224 can be pushed down together with the fixing member A223.

  On the other hand, the fixing member B225 attached to the support column 11 so as to be tiltable by the attachment shaft 212 has a locking recess 226 that meshes with the locking protrusion 224 of the fixing member A223.

  One end of the spring 222 is attached to the fixing member A 223, the other end of the spring 222 is attached to the fixing member B 225, and the tensile force is biased so that the fixing member B 225 tilts about the attachment shaft 212 in the direction of the arrow in the figure. Give power.

  When the conductive plate 1 stored in an inclined state is erected vertically, the locking protrusion 224 of the fixing member A 223 and the locking recess 226 of the fixing member B 225 are engaged with each other, and the fixing protrusion 228 of the fixing member B 225 is engaged with the carriage 51. By being bitten by the fixing bar 229 provided, the vertical standing of the conductive plate 1 can be reliably held.

  When the conductive plate 1 is tilted during storage, the locking projection 224 is pushed down together with the fixing member A223 by operating the lever 221 (tilting in the direction of the broken line arrow in the figure) as described above, and is engaged with the locking recess 226. Is released, the locking projection 224 slides on the sliding curved surface 227 of the fixing member B225, and the fixing member B225 tilts in the direction of the arrow in the drawing by the force urged by the spring 222, and is fixed to the fixing projection 228. When the bite of the bar 229 is released, the vertical standing of the conductor plate 1 can be released.

  The folding mechanism shown in the present embodiment is merely an example, and the mechanism and shape are not limited. The same mechanism can be used as long as the same effect can be obtained.

(Embodiment 3)
FIG. 5 is a schematic side view showing the storage state of the vertical ground plane in the third embodiment of the anechoic chamber according to the present invention.

  The conductive plate 1 is attached to a support 11 via a guide 13, and the support 11 is attached to a carriage 51 having a caster 5 at the bottom as a moving means via a rotation fulcrum 12. Motivation 23 is provided.

  The vertical ground plane is stored in the storage unit 3 including the lifting device 32 in a state where the conductive surface of the conductive plate 1 is parallel to the anechoic chamber floor surface 4. The conductive plate 1 is grounded to the anechoic chamber floor 4 so as to constitute a part of the ground plane as a lid of the storage unit 3.

  When the vertical ground plane is used, it is lifted from the storage unit 3 by the lifting device 32 and moved to a predetermined measurement position. In the vertical standing of the conductive plate 1, when the vertical standing / tilting linear motion machine 23 is operated to push up the column 11, the column 11 rotates about the rotation fulcrum 12, and the conductive plate 1 slides together with the guide 13. Stand up. After the conductive plate 1 is erected vertically, it is grounded with the anechoic chamber floor 4.

(Embodiment 4)
FIG. 6 is a schematic side view showing a storage state of the vertical ground plane in the fourth embodiment of the anechoic chamber according to the present invention. In the present embodiment, the conductive plate 1 of the third embodiment shown in FIG. The storage portion cover plate 33 is configured as a part of the ground and has a structure that can be opened and closed. According to the present embodiment, the entire vertical ground plane can be stored in the storage unit 3.

(Embodiment 5)
7A and 7B are views showing a storage state of the vertical ground plane in the anechoic chamber according to the fifth embodiment of the present invention. FIG. 7A is a schematic side view and FIG. 7B is a schematic front view. 8A and 8B are diagrams showing a usage state of the vertical ground plane in the anechoic chamber according to the fifth embodiment of the present invention. FIG. 8A is a schematic side view, and FIG. 8B is a schematic front view.

  7 (a) and 7 (b), the vertical ground plane includes a plate-like conductor 1a in which the storage unit cover plate 33 is configured as a top plate of the lifting device 32, and is divided into three to form a conductive plate. 1b and 1c move up and down from the floor of the anechoic chamber to the floor while maintaining vertical. When the vertical ground plane is stored, the plate-like conductors 1a, 1b and 1c are folded and stored.

  On the other hand, when the vertical ground plane is used, as shown in FIGS. 8A and 8B, the plate-like conductors 1a, 1b, and 1c rise to the floor of the anechoic chamber and are developed to predetermined dimensions. . Further, it goes without saying that the plate-like conductors 1a, 1b, 1c are grounded to the anechoic chamber floor 4 at this time.

  The method of forming a conductive plate with a plurality of plate-like conductors as in this embodiment can also be applied to other embodiments. For example, in the case of an anechoic chamber having an elevator communicated with a lower floor, a vertical ground plane can be configured by attaching the conductive plate of the present embodiment to the outer surface of the elevator car and grounding it. Workability is further improved by carrying materials and equipment in and out, and even for small cage parts, only the standard dimensions for measurement can be obtained by expanding the dimensions of the conductive surface by expanding the plate-like conductor. It is possible to cope with a large EUT. Moreover, if the dimension of the electroconductive surface at the time of expansion | deployment of a plate-shaped conductor is ensured, there will be no restriction | limiting regarding the structure of a plate-shaped conductor in particular. That is, in addition to the double spread as in the present embodiment, various methods such as a method of connecting a plate-shaped conductor divided vertically to open and close at the center, a method of sliding and deploying and storing the plate-shaped conductor, etc. It can be used after being transformed.

(Embodiment 6)
9A and 9B are diagrams showing a usage state of the vertical ground plane in the anechoic chamber according to the sixth embodiment of the present invention. FIG. 9A is a schematic side view showing when the arm is contracted, and FIG. FIG. 9C is a schematic top view showing when the arm is extended and inclined.

  This embodiment is conducted using the arm 52 that can be expanded and contracted in the lifting / lowering device 32 of the fifth embodiment shown in FIGS. 7 (a) and 7 (b) and FIGS. 8 (a) and 8 (b). A plate 1 is attached.

  Depending on where the lifting device 32 is installed, the conductive plate 1 may not be installed at a predetermined measurement position, and the position of the conductive plate 1 can be adjusted by the extendable arm 52.

  Further, even when the conductive plate 1 and the EUT are not facing each other, the conductive plate 1 can be easily directed to the EUT as shown in FIG. 9C. The arm 52 to be attached may be a known structure such as a pantograph type or a ball joint type.

  Although the embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited to these embodiments, and there are changes in materials and configurations without departing from the gist of the present invention. Is included in the present invention. That is, various modifications and corrections that can naturally be made by those skilled in the art are also included in the present invention.

The schematic side view which shows the accommodation state of the vertical ground plane in Embodiment 1 of the anechoic chamber by this invention. The schematic side view which shows the use condition of the vertical ground plane in Embodiment 1 of the anechoic chamber by this invention. The schematic side view which shows the accommodation state of the vertical ground plane in Embodiment 2 of the anechoic chamber by this invention. Schematic explaining the folding mechanism of the vertical ground plane of FIG. 3 in Embodiment 2 of the anechoic chamber according to the present invention. The schematic side view which shows the accommodation state of the vertical ground plane in Embodiment 3 of the anechoic chamber by this invention. The schematic side view which shows the accommodation state of the vertical ground plane in Embodiment 4 of the anechoic chamber by this invention. The figure which shows the accommodation state of the vertical ground plane in Embodiment 5 of the anechoic chamber by this invention, Fig.7 (a) is a schematic side view, FIG.7 (b) is a schematic front view. The figure which shows the use condition of the vertical ground plane in Embodiment 5 of the anechoic chamber by this invention, Fig.8 (a) is a schematic side view, FIG.8 (b) is a schematic front view. The figure which shows the use condition of the vertical ground plane in Embodiment 6 of the anechoic chamber by this invention, Fig.9 (a) is a schematic side view which shows the time of arm contraction, FIG.9 (b) is the schematic side view which shows the time of arm expansion | extension FIG. 9C is a schematic top view showing when the arm is extended and inclined.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Conductive plate 1a, 1b, 1c Plate-like conductor 2 Support 3 Storage part 4 Anechoic chamber floor 5 Caster 11, 14 Support column 12 Rotating fulcrum 13 Guide 15 Storage shelf 21 Fixing groove 22 Folding mechanism 23 Vertical standing / tilting straight Motivation 31 Slope 32 Elevating device 33 Storage part cover plate 51 Carriage 52 Arms 211 and 212 Mounting shaft 221 Lever 222 Spring 223 Fixing member A
224 Locking projection 225 Fixing member B
226 Locking recess 227 Sliding curved surface 228 Fixing protrusion 229 Fixing bar

Claims (5)

An anechoic chamber for measuring electromagnetic interference,
A conductive plate serving as a reference surface, and means for erecting vertically the conductive plate relative to the ground plane, a housing portion provided under the floor,
The vertically rising means is a lifting device capable of lifting and lowering the conductive plate,
A part or all of the lifting device, all of the conductive plate, said conductive plate in a state of being erected perpendicularly to the ground plane, is lowered to the floor during storage, adapted to lift up the floor during use An anechoic chamber characterized by that. The conductive plate is formed by electrically and mechanically connecting a plurality of plate-like conductors, and the dimensions of the conductive surface of the conductive plate can be changed by developing or accommodating the plate-like conductors. The anechoic chamber according to claim 1, wherein: The anechoic chamber according to claim 1, further comprising a mechanism for adjusting a position of the conductive plate with respect to a measurement target. The anechoic chamber according to any one of claims 1 to 3, wherein the mechanism for adjusting the position of the conductive plate is configured to be extendable and contractible. The anechoic chamber according to any one of claims 1 to 4, wherein a top plate of the elevating device serves as a cover plate of the storage unit .

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