JPS63204700A - Door for electromagnetic shielding room - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention is intended to eliminate the influence of external electromagnetic waves when conducting experiments related to electronic equipment and electromagnetic waves, and to prevent electromagnetic waves generated by experiments from leaking to the outside. It is placed between the doors of the electromagnetic shielding room to create a space that is electromagnetically isolated from the outside.

(Prior technology) The electromagnetic shielding room is made of iron, so that the indoor and outdoor areas are electromagnetically independent.
This is a closed space constructed of metal plates such as copper and aluminum. In such a shielding room, leakage of electromagnetic waves from a door provided for the entrance and exit of people, equipment, etc. has a large effect on shielding characteristics. Therefore, conventionally, in order to reflect the electromagnetic waves that try to leak from the door, a metal knife 3 is provided around the door as shown in Figure 2, and a metal knife 3 is provided around the opening for the door on the shielding room side. It has a structure in which it is brought into contact with the scale-like metal contact piece 4 without any gaps.

(Problem to be solved by the invention) However, in such metal-to-metal contact, the resistance value at the contact part is larger than that at the metal part, so the current induced on the metal surface by electromagnetic waves is not completely reflected, but is partially reflected. flows on the metal side along the contact area and reaches the space on the opposite side. This current electromagnetically couples indoors and outdoors, causing leakage electromagnetic waves.

An object of the present invention is to suppress such transmission current and improve the shielding effect of the shielding chamber.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides means for opening and closing the opening of the electromagnetic shielding chamber, and when closing the opening, the frame of the opening is closed. A door for an electromagnetic shielding room equipped with a metal knife that contacts a scaly gold R contact piece on the side, and when the opening is completely closed, the knife is a contact portion with exposed metal on the surface. The knife contacts the scale-like contact piece, and the surface of the knife near the contact portion is coated with a magnetic material.

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

FIG. 1 is a sectional view showing an electromagnetic shielding structure of an opening of an electromagnetic shielding chamber using an embodiment of the present invention. The fracture surface in this sectional view is a horizontal plane.In the door of this embodiment, as shown in FIG. ! contact with the metal contact piece 4 provided in the shielding chamber 4.
J! It is shorted to 5.

This knife 3 is provided at the edge of the door 6. This knife 3 has 1 degree of ferrite at the tip and 2 degrees of ferrite at the root, except for the part that contacts the contact piece 4 when the door is closed.
are applied to each.

Ferrite 1 and Ferrite 2 have the same composition, but the thickness of Ferrite 1 applied to the tip is thinner than the thickness of Ferrite 2 applied to the root. This is to reduce the deformation of the contact piece 4 when the contact piece 4 passes, and to prevent the shielding effect from deteriorating due to deterioration of the elasticity of the contact piece 4.

Shielding room wall 5. Door 6 and knife 3 are made of iron.

It is made of metal such as aluminum. Also, the contact piece 4 is made of phosphor blue and has a spring-like structure. It is a Jm piece.

The shielding effect obtained with the conventional structure shown in Figure 2 is as follows.
This is because the metal knife 3 around the door 6 makes strong contact with the metal contact piece 4 on the shielding room side due to the force of the spring, and this part reflects electromagnetic waves, electromagnetically separating the indoor room 7 and the outdoor room 8. be. However, since the resistance value of these contact parts is higher than that of metal parts, the current induced in the knife 3 by electromagnetic waves is not completely reflected, but a portion passes through the metal parts to the opposite side, causing leakage of electromagnetic waves. .

Ferrite 1 and ferrite 2 shown in FIG. 1 play the role of absorbing the current flowing along the knife edge 3 and passing through the contact portion with the contact piece 4, thereby improving the shielding effect.

The reason why ferrite coated on a metal surface absorbs current is because the magnetic loss of ferrite acts on the magnetic field created by the current flowing locally on the metal surface due to the skin effect.

(Effects of the Invention) The electromagnetic shielding room door according to the present invention absorbs the leakage current from the contact portion between the knife and the metal contact piece on the shielding room side, which could not be suppressed in the past, by using ferrite instead of applying it to the knife. Therefore, the present invention has the effect of improving the electromagnetic shielding performance as described above.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an electromagnetic shielding structure for an opening of an electromagnetic shielding chamber using an embodiment of the present invention, and FIG. 2 is a sectional view showing an electromagnetic shielding structure for an opening of an electromagnetic shielding chamber using a conventional door. FIG. 1... Ferrite applied to the tip of the knife,
2... Ferrite applied to the root of Naifetsuji, 3
...Metallic knife, metal contact piece for 4, 5...
Electromagnetic shielding room wall, 6... Electromagnetic shielding room door, 7...
Shielding indoor space, 8... Shielding outdoor space.

Claims (2)

[Claims] (1) An electromagnetic shielding room door that opens and closes the opening of the electromagnetic shielding room and is equipped with a metal knife edge that comes into contact with the scale-like metal contact piece on the frame side of the opening when the opening is closed. In the above, when the opening is completely closed, the knife edge contacts the scale-like contact piece at a contact portion where metal is exposed on the surface, and the surface of the knife edge near the contact portion is coated with a magnetic material. An electromagnetic shielding room door characterized by: (2) The electromagnetic shielding room door according to claim 1, wherein the magnetic material is ferrite.