JPH08199937A - Floor surface cleaning method for entrance and exit of shield room - Google Patents

Abstract

PURPOSE: To prevent the trouble such that contact resistance between a floor surface of an entrance and exit and a shield mesh of a door increases due to dust and hence shielding performance of a shield room is deteriorated. CONSTITUTION: A shield door 1 is a hinged door and a shield mesh 4 is provided on the entire periphery of end surfaces of the door 1. A small pipe 6, the opposite ends of which are closed and on one of the ends of which a connection pipe for a rubber pipe is provided, is fixed to a lower side portion of the face on the closing side of the door 1. A plurality of small holes 8 are provided in the pipe wall of the pipe 6 along the length direction at regular intervals. Openings of the holes 8 are oriented downward. High pressure air is passed through the pipes 6 for a certain period of time from immediately before the door closes. The high pressure air blows off from the holes 8 of the pipe 6 against a floor surface 5 of an entrance and exit to scatter dust on the floor surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of cleaning a floor surface of a doorway of a shield room.

[0002]

2. Description of the Related Art A shielded room is a room which shields electromagnetic energy from intrusion and leakage to the outside.
There are cases where the entire room is covered with a shield material made of metal foil, metal mesh, etc., and cases where the inner wall surface is a shield material.

In the latter shielded room, on five sides except the floor,
Alternatively, an electromagnetic wave absorber installed over the entire surface of a room is an anechoic chamber, which is used for interference wave measurement tests of electronic devices and antenna characteristic evaluation. Shield doors are installed at the entrances and exits of the shielded room including the anechoic chamber so as not to impair the performance of the room.

A conventional shielded door has a structure in which the entire surface of the door is formed of a shield material, and a shield flexible piece such as a shield mesh or a shield finger is fixed to the entire circumference of the end surface. The door was closed by abutting the flexible piece.

[0005]

In the case of the shielded room having the above-mentioned shield door, if dust is present on the floor surface of the entrance / exit, the contact resistance between the shield flexible piece on the lower end surface of the door and the shield material on the floor surface. However, the shielding performance at the entrance and exit deteriorates, and the shielding performance at the shield room deteriorates. Therefore, every time the door is tightened, the floor surface of the entrance and exit must be cleaned with a mop or a beach.

An object of the present invention is to provide a method for cleaning a floor surface of a door of a shield room, which does not require the floor surface of the door to be cleaned with a mop or beach each time the door is tightened without deteriorating the shielding performance at the door. Is to provide.

[0007]

In order to eliminate the above-mentioned troublesomeness, in a shield chamber having a shield door having a shield flexible piece on at least a lower end surface thereof, a plurality of gas blowout small holes are formed on a floor surface of an entrance / exit. Or a plurality of gas blowout small holes are provided at the lower end of the door to blow out gas from the small holes when the door is tightened.

That is, in a method for cleaning a floor surface of an entrance / exit of a shield chamber provided with a shield door having a shield flexible piece at least on a lower end surface thereof, a plurality of floors of the entrance / exit of the shield chamber or a lower end portion of the shield door are provided. The method for cleaning a floor surface of an entrance / exit of a shielded room according to claim 1, wherein dust on the floor surface of the entrance / exit is removed by a gas flow when the door is closed.

[0009]

The gas blown from the small holes directly or indirectly hits the floor surface of the entrance / exit to remove dust and clean the floor surface.

[0010]

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

The first embodiment is shown in FIG. In the longitudinal sectional view of the floor portion of the entrance and exit of the shield room and the lower end portion of the shield door shown in FIG. 1, a shield door 1 (hereinafter referred to as a door) is a hinged door whose entire surface is covered with a shield material 2.
Two ridges 3 are integrally provided around the entire circumference of the end face (only the lower end face is shown in the figure), and the shield mesh 4 is arranged by fitting about half of the cross section between the ridges 3. There is.

The shield mesh 4 is made of a metal mesh woven with metal fibers and wound into a rod shape to have elasticity, and has a semi-cylindrical cross section as shown by a chain double-dashed line when the door 1 is opened. Then, when the door 1 is tightened, the arc portion is pressed against the four-circumferential surface (only the floor surface 5 of the doorway is shown in the figure) made of the shield material at the doorway to shield the doorway.

A thin tube 6 having a length slightly shorter than the lower side is fixed to the lower side of the surface of the door 1 on the closing side (left side in the figure).

The narrow tube 6 is formed by closing both ends, projecting a connecting tube 7 above one end, and opening small holes 8 in the lower tube wall at regular intervals (for example, every 50 mm).

The thin tube 6 is connected by a rubber tube 18 to an air compressor (both not shown) via an electromagnetic valve.

The solenoid valve has a free end of the door 1 immediately before the door 1 is closed by a signal from a limit switch provided in relation to the door 1, for example, at a position indicated by a chain double-dashed line for a certain period of time or It is opened until it is closed and high-pressure air is supplied to the thin tube 6.

When the open door 1 is closed, the air blows downward from the small holes 8 and passes through the floor surface 5 while hitting the floor surface 5 at the entrance / exit, and the shield mesh 4 is followed by the floor surface 5 afterwards.
Since the dust is not left on the floor surface, the contact between the shield mesh 4 and the floor surface 5 can be always maintained normally without using human hands.

The second embodiment is shown in FIG. In the second embodiment, as shown by the chain double-dashed line in FIG. 2, the door 9 is of a type in which it is slightly lifted and removed from the entrance and then slides. The case where a plurality of small holes 10 are opened is shown.

Instead of the narrow tube 6 in FIG. 1, a closed space 11 having a rectangular cross section is provided inside the floor surface 5 (back side), and a connecting curved tube 12 is provided vertically. The small hole 10 is inclined from the closed space 11 to the outside of the shield chamber and upward.

Since the closed space 11 is connected to the air compressor via an electromagnetic valve, as in the case of the thin tube 6 in FIG. 1, when the door 9 is closed, the air blown obliquely from the small hole 10 is removed. ,
The lower end surface of the door 9 that approaches the floor surface 5 while descending and the shield mesh 4 are caused to cause a flow toward the floor surface 5 or a flow along the floor surface 5. This inverted air is on the floor 5
Remove dust from.

Since the dust adhering to the shield mesh 4 is removed by the air from the small holes, the shield mesh 4 and the floor surface 5 are always in good contact with each other.

The third embodiment is shown in FIG. The third embodiment is a case where the open door 13 has shield fingers 14 as shield flexible pieces.

The shield finger 14 is formed by forming a metal spring plate into a substantially Z shape, and when the door is tightened, the free end elastically contacts the four circumferential surfaces of the doorway (the figure shows only the floor surface 5). Shield.

The door 13 is provided with a closed space 15 inside the door 13 along the lower side of the surface on the closed side (left side in the figure), and a connecting curved pipe 12 connected to the closed space 15 is provided on the left side surface so as to project. A plurality of small holes 16 are formed at the lower end surface along the inner wall of the left side surface at regular intervals, and the thin tube 6 in FIG. 1 is built in.

When the door 13 is tightened, air blows out from the small holes 16 to scatter dust before the shield fingers 14 make elastic contact with the floor surface to clean the floor surface 5.

In FIG. 3, the concave portion 17 provided on the floor surface of the shield chamber is an elongated groove and accommodates dust when the floor surface 5 and the floor surface of the shield chamber are flatly connected to each other. Prevent returning to 5.

[0027]

According to the present invention, the floor surface of the entrance and exit of the shield chamber is automatically cleaned every time the shield door is tightened, so that the shield flexible piece of the door and the floor surface are kept in good contact with each other. Since the door is closed, the shielding performance of the shield room and the anechoic chamber does not deteriorate, and measurement work can be performed smoothly.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a main part of a shield chamber showing a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of an essential part similar to FIG. 1, showing a second embodiment of the present invention.

FIG. 3 is a longitudinal sectional view of an essential part similar to FIG. 1, showing a third embodiment of the present invention.

[Explanation of symbols]

 1,9,13 (Shield) Door 2 Shielding material 3 Protrusions 4 Shield mesh 5 (At the entrance / exit) Floor surface 6 Small tube 7 Connecting tube 8,10,16 Small hole 11,15 Closed space 12 Connecting curved tube 14 Shield finger 17 Recess 18 rubber tube

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masahide Chiba 6-7-1, Koriyama, Taichiro-ku, Sendai-shi, Miyagi Tokin Co., Ltd.

Claims (1)

[Claims] 1. A method for cleaning a floor surface of an entrance / exit of a shield chamber, comprising a shield door having a shield flexible piece provided at least on a lower end surface thereof, wherein a plurality of pieces are provided on a floor surface of the entrance / exit of the shield chamber or at a lower end portion of the shield door. The method for cleaning a floor surface of an entrance / exit of a shielded room according to claim 1, wherein dust on the floor surface of the entrance / exit is removed by a gas flow when the door is closed.