JP2001108164A - Flexible tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flexible tube which shields electromagnetic waves generated from an electric wiring cable passed through the interior of the flexible tube and shields electromagnetic waves from the outside. SOLUTION: This flexible tube is a metal tube obtained by engaging metal plates 2 having an S-shaped section with each other and inserting a special packing 4 in the engaging part while projecting and recessed parts are formed on the outer peripheral surface, and the special packing 4 is formed by covering the outer periphery of an elastic body 4a with a conductor 4b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a flexible tube,
More specifically, the present invention relates to shielding of electromagnetic waves generated from an electric wiring cable passing through a flexible pipe or shielding of electromagnetic waves from outside.

[0002]

2. Description of the Related Art Although a conventional metal flexible tube has a certain electromagnetic shielding effect, in recent years, with the development of computer-related equipment, a flexible tube having a higher degree of shielding has been required. Was. There are various countermeasures, one example of which will be described with reference to FIG. 6, which shows a cross section of a flexible tube and a developed view of an elastic member. The flexible tube 10 first inserts a packing (cotton thread or the like) 40 into the strip-shaped metal plate 2 while overlapping the S-shaped cross section.
An uneven portion 1a is formed on the outer peripheral surface.

In order to prevent electromagnetic waves, a metal braid 6 formed by weaving a fine conductive thin copper wire in a stitch shape is wound around a metal tube 5, and the outside of the metal tube 5 is passed through an extruder (not shown). An elastic member made of synthetic resin and a metal braid formed integrally with the elastic member, or a metal tube is coated with an elastic member made of synthetic resin or the like, and an outer peripheral surface of the metal tube is coated with metal. There is a braided type and a type in which a metal plate of a metal tube is made of copper to shield electromagnetic waves.

[0004]

A flexible tube or the like which is formed by coating a metal braid or a copper wire with a synthetic resin film becomes heavy, or the flexible tube itself becomes heavy, or a metal (copper wire) is used. ) There is a problem that it is not possible to cope with a complicated facility method because the cost is increased by braiding and it is difficult to twist in the circumferential direction. In addition, a metal tube made of copper is not economically used and is currently not generally used. Accordingly, the present invention provides a flexible tube that exhibits electromagnetic wave shielding performance, has flexibility, and is excellent in economic efficiency.

[0005]

According to the first aspect of the present invention, there is provided a flexible pipe comprising:
This is a flexible metal tube in which a metal plate having an S-shaped cross section is meshed, and a special packing is inserted into the meshing portion and an uneven portion is formed on the outer peripheral surface. And, by using a special packing made by covering the outer periphery of the elastic body with the conductor, the metal tube is in a linearly connected state,
The current is linear, not in the spiral direction of the metal tube.
That is, it flows to the shortest distance. In the flexible tube according to the second aspect, the outer peripheral surface of the metal tube is covered with an elastic member such as a resin, so that the metal tube can be curved and twisted in the circumferential direction, and exhibits an electromagnetic wave shielding effect. Further, in the flexible tube according to the third aspect, since the conductor is formed in close contact with the irregularities on the outer peripheral surface of the metal tube in the longitudinal direction, the electromagnetic wave shielding effect can be further improved.

[0006]

Embodiments of the present invention will be described with reference to the drawings. Note that components having the same functions as those in the related art are denoted by the same reference numerals. FIG. 1A is a cross-sectional view of a flexible tube 1, and FIG.
FIG. 2B is a right side view, FIG.
(B) is a view as seen from arrows B to B. The flexible tube 1 is first prepared in a well-known manner, for example, by a galvanized strip-shaped metal plate 2.
Is formed in a substantially S-shaped cross section, and a downward front edge 2b on the other side edge of the metal plate 2 is superimposed on an upward rear edge 2a on the other side edge of the metal plate, and special packing is performed. 4 is spirally wound while being compressed, and the uneven portion 1a is formed on the outer peripheral surface.
And a metal tube 5 forming the spiral groove 3 in the inner peripheral portion is formed.

[0007] The special packing 4 is shown in FIG.
As shown in the figure, on the outer periphery of the string-like elastic body (rubber or the like) 4a,
The conductor 4b is formed by coating (covering in a net shape with a copper wire or the like). Therefore, the special packing 4 mounted between the rear edge 2a and the front edge 2b of the metal plate 2
Due to the elasticity (repulsion) action of a, through the conductor 4b,
The valley 2X of the rear edge 2a of the metal plate 2 and the ridge 2Y of the front edge 2b are joined (conductive). Even if a bending action or a twist action is applied to the metal tube 5, the elastic (repulsive force) action of the elastic body 4a causes the trough 2X of the rear edge 2a and the peak of the front edge 2b of the metal plate 2 to move. The portion 2Y maintains the junction (conduction) via the conductor 4b. Therefore, the electromagnetic wave can be shielded by the metal plate 2 and
Since the special packing 4 is spirally wound, the flexible pipe can be easily twisted in the circumferential direction.

In addition to shielding the electromagnetic waves by the special packing 4, the metal tube 5 has a thin conductor 8 (for example, a resin tape coated with copper foil or a resin tape) in order to further improve the effect. , Copper foil, etc.) are formed in the longitudinal direction of the metal tube 5 and the uneven portion 1a on the outer peripheral surface of the metal tube 5 through an elastic member 7 such as a synthetic resin. The thickness and material of the conductor 8 such as copper foil are as follows.
The conductor 8 is appropriately selected according to the intensity of the electromagnetic wave, and when a resin tape coated with copper foil is used as the conductor 8, at least the side in close contact with the metal tube 5 has a conductor (copper foil or the like). And

Further, in the present embodiment, the conductor 8 is in the form of a thin strip, and
As shown in (B), the gap 9 is formed, and it is composed of five pieces arranged in parallel with the longitudinal axis 20. The number of the conductors 8 and the width of one piece are determined by the intensity of the electromagnetic wave. Etc. may be taken into account.

When the gap 8 is formed and the conductor 8 is formed in close contact with the outer peripheral surface of the metal tube 5, the gap 9 is formed.
When the elastic coating such as resin penetrates deeply into the concave portion of the metal tube 5 and the flexible tube 1 is curved along the axis 20, an effect of increasing the adhesion between the metal tube 5 and the coating is produced. Note that the conductor 8 may be configured to cover the entire outer periphery of the metal tube 5. In this case, however, the axis of the conductor 8 may be easily twisted in the circumferential direction. It is desirable to form one or more cuts in 20 directions.

Next, a description will be given of a method of manufacturing the flexible tube having the above structure. First, the conductor 4b of the string-like elastic body 4a is formed.
A special packing 4 for covering is prepared in advance. Then, the rear side edge 2a and the front side edge 2b of the substantially S-shaped metal plate are overlapped, and the metal tube 5 is formed while the special packing 4 is inserted. Next, using the metal tube 5, the concept of mounting the conductor 8 by a resin extruder and covering the outer peripheral surface of the metal tube with an elastic member such as resin is shown in FIG.
This will be described with reference to FIG.

The five conductors 8 are guided to the outer periphery of the metal tube 5 via the nipple 15 and
Along the longitudinal direction (axial direction) of the resin tube, and the resin melted in a resin melting portion (not shown) is jetted to the outer periphery of the metal tube 5 via the conduit 16 and pressed by the die 17 in the inner diameter direction.
The elastic member 7 is formed by deeply penetrating the uneven portion 1a of the metal tube. Therefore, when the five conductors 8 and the molten resin are supplied while pulling the metal tube 5,
The conductor 8 is formed in the direction of the axis 20 while being in close contact with the uneven portion 1a on the outer peripheral surface of the metal tube 5 by the synthetic resin pressed by the die 17, and then cooled,
The flexible tube 1 shown in FIG.

Since the conductor 8 of the flexible tube is formed in close contact with the uneven portion 1a on the outer peripheral surface of the metal tube 5, even if the flexible tube 1 is curved along the axis 20, Even if twisted in the direction, the conductor 8 bends or twists together with the uneven portion 1a, so that the conductor 8 can be bent or twisted like a conventional flexible tube without breaking without breaking, and the manufacturing method is as follows. Simple and economical.

Next, the flow of current when the flexible tube 1 having the above configuration is mounted on a control box or the like will be described with reference to FIG. The flexible tube 1 is connected to the control box via the connector 30, and a metal nipple 31 is inserted into the hole 29 b formed in the side plate 29 a of the control box via the body packing 35 a and fastened with the lock nut 32. Next, a convex screw 3 is attached to the end of the cut flexible tube 1.
A metal terminal cap 34 forming 4a is attached, and fixed with a cap nut 37 via a seal gland 35b and a U sleeve 36.

The special packing 4 is formed by a resilient (repulsive force) action of the elastic body 4a so that the valley 2X of the rear edge 2a of the metal plate 2 is formed.
And the crest 2Y of the front side edge 2b are joined (conductive) via the conductor 4b. In addition, since the metal tube 5 is in contact with the convex screw 34a of the terminal cap 34 (point A), the metal tube 5 is in conduction with the terminal cap 34, so that the current flows through the metal tube 5 ( It is possible to flow not in the spiral direction of the metal plate 2) but linearly, that is, at the shortest distance. Further, since the conductor 8 is also formed in close contact with the uneven portion 1a on the outer peripheral surface of the metal tube 5, the terminal cap 3 is formed via the convex screw 34a of the terminal cap 34 (point A).
4 is in a conductive state. The terminal cap 34
Is in contact with a metal nipple 31 at a point B and conducts, the nipple 31 contacts a side plate 29a of the control box at a point C, and the control box is grounded.

As described above, the metal tube 5 is connected linearly via the special packing 4 to conduct to the control box, and the conductor 8 is also the same. Therefore, the current caused by the electromagnetic waves generated in the metal tube 5 and the conductor 8 flows under the ground via the ground line (earth wire) of the control box in a straight line at the shortest distance, and has an electromagnetic wave shielding effect.

Next, a flexible tube 1A shown in FIG.
This is a modified example of the conductor 8, in which a strip-shaped conductor 8 is formed on the outer peripheral surface of the metal tube 5 by α ゜ (4
An angle of 5 ° or less is desirable in consideration of the amount of use and effect of the conductor. Is formed in close contact with the substrate. The manufacturing method is similar to that shown in FIG. 3, in which the conductor 8 is inserted into the metal tube 5 so as to be spirally wound, and is formed while being sent. The flexible pipe 1B shown in FIG.
The conductor 8a (conductive thin wire-shaped copper wire or the like) is placed on the outer peripheral surface of the metal tube 5 at an angle of β ゜ (45 ° or less) with respect to the axis 20. In consideration of the above, it is preferable to insert and feed while spirally winding (right-handed or left-handed) with a rough lead while forming the gap 9b.

Even if the metal tube 5 is formed using the special packing 4 and the conductors 8 and 8a are spirally wound, the metal tube 5 is formed in close contact with the uneven portion 1a on the outer peripheral surface of the metal tube 5. Therefore, the flexible tube can be curved or twisted in the circumferential direction, and exhibits an electromagnetic wave shielding effect.

[0019]

According to the first aspect of the present invention, the flexible tube is formed by using a special packing formed by coating a conductor on the outer periphery of the elastic body, so that the electric current is not linearly formed in the spiral direction of the metal tube, that is, in the shortest direction. It is possible to flow over a distance, and the electromagnetic wave shielding effect can be improved. In the flexible tube according to the second aspect, the outer peripheral surface of the metal tube is covered with an elastic member such as a resin, so that the metal tube can be curved and twisted in the circumferential direction, and exhibits an electromagnetic wave shielding effect. Further, in the flexible tube according to the third aspect, since the conductor is formed in close contact with the irregularities on the outer peripheral surface of the metal tube in the longitudinal direction, the electromagnetic wave shielding effect can be further improved.

[Brief description of the drawings]

1A is a cross-sectional view of a flexible pipe, FIG. 1B is a right side view of the flexible pipe, and FIG. 1C is a view showing a special packing.

FIG. 2 is a diagram showing an A-A section and a BB section of FIG. 1 (B).

FIG. 3 is a view showing a concept of manufacturing a flexible tube.

FIG. 4 is a sectional view showing a connection example of a flexible tube.

FIG. 5 is a diagram showing a cross section of a flexible tube provided with another conductor.

FIG. 6 is a diagram showing a cross section of a conventional flexible pipe and a development of an elastic member.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 1A, 1B Flexible tube 1a Uneven part 2 Metal plate 3 Spiral groove 4 Special packing 4a Elastic body 4b Conductor 5 Metal tube 7 Elastic member 8, 8a, 8b Conductor 9, 9a, 9b Gap 20 Axis line

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3H111 AA03 BA01 BA15 CA03 CA06 CB03 DA02 DA26 DB23 EA05 5E321 AA03 AA21 BB21 BB44 GG09 5G357 DA05 DB01 DB02 DD01 DD05 DD10 DE10

Claims (3)

[Claims] 1. A flexible tube of a metal tube in which a metal plate having an S-shaped cross section is engaged, and a special packing is inserted into the engagement portion, and a concave / convex portion is formed on an outer peripheral surface. A flexible tube formed by coating a conductor on the outer periphery of an elastic body. 2. The flexible tube according to claim 1, wherein an outer peripheral surface of the metal tube is covered with an elastic member such as a resin. 3. The method according to claim 2, wherein the conductor is formed in close contact with the uneven portion on the outer peripheral surface of the metal tube in the longitudinal direction.
Flexible tube.