JPH10196856A - Flexible tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shut away, in a flexible tube, electromagnetic waves caused by an electric wire inserted through the tube. SOLUTION: A flexible tube comprises a metal tube having on its outer periphery a recessed and projected part 1a by means of S-sectioned metal plates 2. The metal tube is coated with an elastic member 7 of synthetic resin such that an electric conductor 8 is brought into close contact with the recessed and projected part 1a along the longitudinal direction of the metal tube by the elastic member 7. That simple and economical constitution enables the flexible tube to circumferentially twist.

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. First, the flexible tube 10 is formed by inserting the packing 4 into the band-shaped metal plate 2 while overlapping the cross-section in an S-shape, so that the uneven surface 1a is formed on the outer peripheral surface and the spiral line is formed on the inner peripheral portion. A metal tube 5 forming the groove 3 is formed. Then, in order to prevent electromagnetic waves, a metal braid 6 in which fine conductive thin copper wire is woven in a stitch shape is wound around the metal tube 5, and a synthetic resin is formed on the outside thereof via an extruder (not shown). Or the metal braid 6 is formed integrally with the elastic member 7 or, in the above, the metal tube is coated with an elastic member such as a synthetic resin and the outer peripheral surface thereof is metal braided. And a type in which a metal plate of a metal tube is made of copper to shield electromagnetic waves.

[0003]

A flexible tube or the like made of a metal braid or a copper wire and wound with a synthetic resin film increases the weight of the flexible tube itself or the copper wire braid. There is a problem that it is not possible to cope with a complicated facility method due to an increase in cost due to the application and a difficulty in twisting 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.

[0004]

According to the first aspect of the present invention, there is provided a flexible pipe comprising:
A metal tube having an uneven portion formed on an outer peripheral surface thereof through a metal plate having an S-shaped cross section is formed, and the outer peripheral surface of the metal tube is covered with an elastic member such as a synthetic resin. The conductor is formed in close contact with the irregularities on the outer peripheral surface in the longitudinal direction of the metal tube. Since the conductive body is formed in close contact with the uneven portion on the outer peripheral surface of the metal tube, when the conductive body itself forms the unevenness, when the flexible tube is bent, it can be bent without difficulty, and twisted in the circumferential direction. It can be easily constructed and is economical. In the flexible tube according to the second aspect, the conductive body is formed in a thin band shape, is formed so as to have a gap on the outer peripheral surface of the metal tube, and is formed in close contact with the continuous uneven portion in the longitudinal direction. Therefore, a gap is formed without covering the entire outer circumference of the metal tube with a conductor.
Without reducing the electromagnetic wave shielding effect, the amount of conductors used is reduced, and the economy is further enhanced.

According to a third aspect of the present invention, there is provided a flexible tube having a metal tube having an S-shaped cross section, a metal tube having an uneven portion formed on an outer peripheral surface thereof, and covering the outer peripheral surface of the metal tube with an elastic member such as a resin. In this method, a belt-shaped conductor is spirally wound around an axis in a longitudinal direction of an outer peripheral surface of a metal tube, and is formed in close contact with an uneven portion on the outer peripheral surface. Even if the belt-shaped conductor is formed in a spiral shape (right-handed or left-handed) on the outer peripheral surface of the metal tube, the flexible tube can be curved and twisted in the circumferential direction, and also has an electromagnetic wave shielding effect. I do. A flexible tube according to a fourth aspect of the present invention is obtained by replacing the conductive body of the third aspect with a copper wire or the like, and can be formed in the same manner as in the third aspect and has substantially the same effect.

[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 to have a substantially S-shaped cross section, and a downward front edge 2b at the other side edge of the metal plate 2 is superimposed on an upward rear edge 2a at the other side edge of the metal plate, and soft synthesis is performed. It is spirally wound while interposing a packing 4 of a thread such as resin to form an uneven portion 1a on the outer peripheral surface and a spiral groove 3 on the inner peripheral portion.
Is formed.

In order to shield electromagnetic waves, a thin conductive body 8 having conductivity (for example, a resin tape coated with copper foil, a copper foil or the like) is interposed through an elastic member 7 such as a synthetic resin. Then, the metal tube 5 is formed in close contact with the uneven portion 1a on the outer peripheral surface of the metal tube 5 in the longitudinal direction. In addition, the thickness and material of the copper foil and the like of the conductor 8 are appropriately selected according to the strength of the electromagnetic wave. When the conductor 8 is a resin tape coated with copper foil, at least a metal tube is used. The side that is in close contact with 5 has a conductive body (such as a copper foil).

In the present embodiment, the conductor 8 is a thin strip, and the conductor 8 is disposed on the outer peripheral surface of the metal tube 5 as shown in FIG.
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 of them are determined by the intensity of the electromagnetic wave. Etc. may be taken into account. When the conductive body 8 is formed in close contact with the outer peripheral surface of the metal tube 5 by forming the gap 9 in this way, the gap 9 is such that the elastic coating such as resin penetrates deeply into the concave portion of the metal tube 5 and the flexible tube 1 When curved along 20, the 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, but in this case, the conductor 8 is required to be easily twisted in the circumferential direction. It is desirable to form one or more cuts in the direction of the axis 20 of FIG.

Next, a method of manufacturing the flexible pipe having the above-described configuration will be described with reference to FIG. 3 showing the concept of a resin extruder. The five conductors 8 are guided to the outer periphery of the metal tube 5 through the nipple 15 and extend along the longitudinal direction (axial direction) of the metal tube 5. The elastic member 7 is ejected to the outer periphery of the metal tube 5 via the conduit 16 and pressed in the inner diameter direction by the die 17, so that the elastic member 7 is formed by deeply penetrating into the uneven portion 1 a of the metal tube. Therefore, when the five conductive members 8 and the molten resin are supplied while pulling the metal tube 5, the conductive members 8 are adhered to the uneven portion 1 a on the outer peripheral surface of the metal tube 5 by the synthetic resin pressed by the die 17. Axis 20
FIG. 1 by forming in the direction and then cooling
The flexible tube 1 shown in FIG.

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, so that the flexible tube 1 can be curved along the axis 20 or can be circumferentially extended. Even if the conductor 8 is twisted in the direction, the conductor 8 bends or twists together with the uneven portion 1a, so that it 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 structure 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 conductor 8 is formed in close contact with the uneven portion 1a on the outer peripheral surface of the metal tube 5, and the metal tube 5
Is in contact with the convex screw 34a of the terminal cap 34 (point A), so that the conductor 8 is in conduction with the terminal cap 34. Also, terminal cap 3
4 makes contact with the metal nipple 31 at point B and conducts,
Further, the nipple 31 contacts the side plate 29 of the control box at the point C. The control box is provided with a ground (earth). As described above, the conductor 8 conducts with the control box, and the electric current generated by the electromagnetic wave in the conductor 8 flows under the ground via the ground line (earth wire) of the control box in the shortest distance, and the electromagnetic wave It has a shielding effect.

Next, a flexible tube 1A shown in FIG.
A belt-shaped conductor 8 is attached to the outer peripheral surface of the metal tube 5 by the axis 2.
It is helically wound (right-handed or left-handed) while forming a gap 9a at α ゜ (note that an angle of 45 ° or less is desirable in view of the amount of use and effect of the conductor) with respect to 0, and metal It is formed in close contact with the uneven portion 1a on the outer peripheral surface of the tube 5. 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 out. FIG. 5 (B)
The flexible tube 1B shown in FIG. 1 is a thin conductive copper wire or the like that connects the conductor 8a to the outer surface of the metal tube 5 at an angle .beta. But,
It is desirable to take into account the amount of use and effect of the conductor), and is formed by inserting and sending while spirally winding (right-handed or left-handed) with a rough lead while forming the gap 9b.

Even if the conductors 8 and 8a are spirally wound, the conductors 8 and 8a are formed in close contact with the uneven portion 1a on the outer peripheral surface of the metal tube 5, so that the flexible tube is bent or circumferentially bent. It can be twisted and has the effect of shielding electromagnetic waves. The flexible tubes 1A and 1B of FIGS. 5A and 5B are formed by spirally winding the conductors 8 and 8a while forming the gaps 9a and 9b. Alternatively, it may be wound on the entire outer peripheral surface.

[0015]

According to the first aspect of the present invention, since the conductive body is formed in close contact with the uneven portion on the outer peripheral surface of the metal tube, the flexible tube can be smoothly curved along the axis. In addition, it can be twisted in the circumferential direction, can be simply configured, and is highly economical. In addition, the flexible tube according to the second aspect is such that a strip-shaped conductor is formed in close contact with the uneven portion so as to have a gap on the outer peripheral surface of the metal tube, and without reducing the electromagnetic wave shielding effect, The use amount can be reduced. Also, the gap formed in this flexible tube is
When the elastic coating such as resin penetrates deeply into the concave portion of the metal tube and the flexible tube is curved along the axis, an effect of increasing the adhesion of the coating of the metal tube 5 is produced. The flexible tube according to claim 3 is such that the band-shaped conductor is formed in a spiral shape in close contact with the uneven portion on the outer peripheral surface of the metal tube, and the flexible tube can be curved or twisted, and An electromagnetic wave shielding effect can be exhibited. The flexible tube according to claim 4, wherein a linear conductor such as a copper wire is formed in a helical shape in close contact with the uneven portion on the outer peripheral surface of the metal tube, and the flexible tube is bent,
Alternatively, it can be twisted and can exhibit an electromagnetic wave shielding effect.

[Brief description of the drawings]

FIG. 1 is a diagram showing a cross section and a right side surface of a flexible tube.

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 Helical groove 4 Packing 5 Metal tube 7 Elastic member 8, 8a, 8b Conductor 9, 9a Gap 20 Axis line

Claims (4)

[Claims] 1. A flexible tube in which a metal tube having an irregular portion formed on an outer peripheral surface thereof via a metal plate having an S-shaped cross section is formed, and the outer peripheral surface of the metal tube is covered with an elastic member such as a resin. A flexible tube, wherein a conductive body is formed in close contact with the uneven portion on the outer peripheral surface of the metal tube via the elastic member. 2. A flexible tube in which a metal tube having an uneven portion formed on an outer peripheral surface thereof via a metal plate having an S-shaped cross section is formed, and the outer peripheral surface of the metal tube is covered with an elastic member such as a resin. A flexible tube, wherein a band-shaped conductor is formed so as to have a gap in the longitudinal direction of the outer peripheral surface of the metal tube via the elastic member, and is formed in close contact with the uneven portion on the outer peripheral surface. 3. A flexible tube in which a metal tube having an uneven portion formed on an outer peripheral surface thereof via a metal plate having an S-shaped cross section is formed, and the outer peripheral surface of the metal tube is covered with an elastic member such as a resin. A flexible tube, wherein a belt-shaped conductor is spirally wound around the longitudinal axis of the outer peripheral surface of the metal tube via the elastic member, and is tightly formed on the uneven portion of the outer peripheral surface. 4. A flexible tube in which a metal tube having an uneven portion formed on an outer peripheral surface thereof through a metal plate having an S-shaped cross section is formed, and the outer peripheral surface of the metal tube is covered with an elastic member such as a resin. A linear conductor is spirally wound around the longitudinal axis of the outer peripheral surface of the metal tube via the elastic member, and is tightly formed on the concave and convex portions of the outer peripheral surface. tube.