JP2002228060A - Flexible tube, and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the curving characteristic and the fatigue life of a flexible tube. SOLUTION: This flexible tube 1 is a metal tube having uneven parts on the outer circumferential surface while fitting a sealing member 6 into an engagement part of metal plates 2 of S-shaped section, and the sealing member 6 is a string having projecting parts 6a and recessed parts 6b in an alternate manner.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a flexible tube,
More specifically, the present invention relates to improving the bending characteristics of a flexible tube and extending fatigue life.

[0002]

2. Description of the Related Art Conventional metal flexible tubes have various structures, and the main ones will be described with reference to FIGS. (Conventional Example 1) FIG. 4 showing a left side surface of a flexible tube 1A.
(A), FIG. 4 (B) showing a front cross section, FIG. 4 (C) showing a partially enlarged front cross section, FIG. 5 (A) showing a front cross section in a curved state, FIG. 5 showing a state connected to a connector. (B)
This will be described with reference to FIG. The flexible tube 1A is formed by first overlapping a strip-shaped metal plate 2 with an S-shaped cross section, and inserting a relatively thick sealing material (rubber, cotton thread or the like) 66 into a fitting portion thereof to form an adjacent strip. Close to the metal plate 2 (L
1 = 2 mm, L2 = 4 mm), and the metal tube 5 is formed by narrowing the width of the spiral groove 3.

[0003] The flexible tube 1A is formed by coating the outer peripheral surface of the metal tube 5 by applying pressure to the coating member (synthetic resin or the like) 7 using a resin extruder. The covering member 7 bites into a concave portion 5a formed in the metal tube 5 and is formed on a flat outer peripheral surface 7a. And this flexible tube 1A is
It has a movable characteristic (a state in which it does not return to its original state after being bent), and when the packing 9 is attached to the terminal and tightened with the cap nut 10a attached to the connector 10 for device connection, the outer peripheral surface 7a of the covering member 7 Is waterproof because it is flat. However, this flexible tube 1A has a drawback that, when it is curved, its radius of curvature R is large and its weight per unit length is heavy.

(Conventional Example 2) FIG. 6 (A) showing a left side surface, FIG. 6 (B) showing a front cross section, FIG. 6 (C) showing a partially enlarged front cross section, and a curved state of a flexible tube 1B. 7 (A) showing a front cross section of FIG. 7A and FIG. 7 (B) showing a state of connection with a connector. This flexible tube 1B
The metal tube 5 is formed without inserting the sealing material 66 in the flexible tube 1A (joining the S-shaped metal plate 2) and making the width of the spiral groove 3 as large as possible. Then, while the inside of the metal tube 5 is evacuated by a resin extruder, the covering member 7 is thinly formed on the outer peripheral surface of the metal tube 5, and a projection 7 d is formed in the concave portion 5 a formed in the metal tube 5. The surface 7a is covered so as to form a large concave portion 7b.

The flexible tube 1B has a drawback that when it is used in a movable state, the S-shaped metal plates 2 are in contact with each other, so that the portion is worn. Because of the joining by the metal plate 2, it is difficult to maintain the inside of the metal tube 5 at a constant negative pressure. As a result, it is difficult to form the concave portion 7b with the uniform covering member 7, and the protrusion 7d is formed in the concave portion 5a formed in the metal tube 5 so that the covering member 7 bites into the concave portion 5a. However, there is a problem that it is easily damaged. A packing 9 is attached to the end of the flexible tube 1B, and a connector 10 for device connection is attached.
However, even when the cover member 7 is tightened with the cap nut 10a, a large recess 7b formed in the outer peripheral surface 7a of the covering member 7 causes a gap to be generated, so that sufficient waterproofness cannot be exhibited.

(Conventional Example 3) FIG. 8 (A) showing a left side surface, FIG. 8 (B) showing a front cross section, FIG. 8 (C) showing a partial enlargement of a front cross section, and a curved state of a flexible tube 1C. A description will be given with reference to FIG. Flexible tube 1C
It has the same structure as the flexible tube 1B, but has a structure in which the outer peripheral surface of the metal tube 5 is covered with the covering member 7 without forming irregularities. This flexible tube 1C has a drawback that when the metal tube 5 is pulled, it separates from the covering member 7 and comes off. Further, when the flexible tube 1C is bent, irregular wrinkles 7c are generated in the inner covering member 7 and the movable characteristics are not good, so that it cannot be used in a movable place.

[0007]

As described above, the flexible tube 1A has the disadvantage that the radius of curvature when curved is large and the weight per unit length is heavy. The flexible tube 1B has a drawback that the S-shaped metal plates 2 come into contact with each other and wears, and the flexible tube 1C has a drawback that when the metal tube is pulled, it separates from the covering member 7 and comes off. There is.
Therefore, the present invention provides a flexible tube capable of improving the bending characteristics and prolonging the fatigue life.

[0008]

According to the first aspect of the present invention, there is provided a flexible pipe comprising:
A flexible tube of a metal tube in which a metal plate having an S-shaped cross section is meshed, and a sealing material is inserted into the meshing portion, and a concave and convex portion is formed on the outer peripheral surface. By using the sealing member in a shape, the depth of filling the concave portion of the metal tube with the covering member can be easily changed. In the flexible pipe according to the second aspect, the radius of curvature can be reduced when the flexible pipe is curved by forming a protrusion that does not allow the covering member to come off in the concave portion of the metal tube.

A flexible tube according to a third aspect of the present invention is characterized in that a metal plate having an S-shaped cross section is engaged with the outer peripheral surface while a sealing material formed of a bundle of air-permeable threads is inserted into the engaged portion. By forming a protruding portion in the concave portion of the metal tube with a covering member that covers the outer periphery of the metal tube having an uneven portion, it is possible to reduce the radius of curvature when curved.

According to a fourth aspect of the present invention, there is provided a method for manufacturing a flexible tube, comprising:
A metal tube having an irregular portion formed on the outer peripheral surface is manufactured by fitting a letter-shaped metal plate and inserting a gas-permeable sealing material into the engaged portion. As the air-permeable sealing material, a material in which convex portions and concave portions are alternately formed, a material in which yarns are bundled, and the like are used. Then, by setting the inside of the metal tube to a predetermined negative pressure, the negative pressure of the concave portion of the metal tube can be maintained at the predetermined pressure, and a uniform protrusion that does not fall out of the concave portion of the metal tube by the covering member can be formed. Then, a flexible tube that can reduce the radius of curvature can be manufactured.

[0011]

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 left side view of the flexible tube 1, FIG.
2 is a front cross section, (C) is a partially enlarged view of the front cross section, FIG.
(A) is a perspective view showing a state in which the sealing material 6 is inserted into the fitting portion of the metal tube of the flexible tube 1, and (B) is a perspective view showing the sealing material 6.
FIG. 7C is a conceptual diagram showing a manufacturing process of covering the metal tube with the covering member 7. FIG. 3A is a front sectional view of the flexible tube 1 in a curved state, and FIG.
It is a figure which shows the appearance which connected the connector.

The flexible tube 1 is formed by, for example, a well-known method, for example, by forming a metal plate 2 in the form of a galvanized strip into a substantially S-shaped cross section, and facing the lower rear side of the other side edge of the metal plate 2. An upward front edge 2b of the other side edge of the metal plate 2 is overlapped on the edge 2a, and the sealing material 6 is spirally wound while compressing the overlapped portion (FIGS. 1B and 1C). 2
(A)) A metal tube 5 is formed in which a concave portion 5a is formed on an outer peripheral surface and a spiral groove 3 is formed on an inner peripheral portion.
The metal tube 5 formed by stacking the metal plates 2 having the S-shaped cross section has a ratio of L1 = 2 mm and L2 = 4 mm.

As shown in FIG. 2 (B), the sealing material 6 is a string made of synthetic resin, rubber, or the like in which the convex portions 6a and the concave portions 6b are alternately formed. In addition to a circle, the shape is an ellipse or a polygon. The diameter (cross-sectional size) of the convex portion 6a and the concave portion 6b formed on the sealing material 6, the length of the convex portion 6a and the concave portion 6b, etc. are determined by the diameter of the flexible tube 1 and the metal tube 5 to be used. Lengths L1 and L2 to be formed, a radius of curvature R when bending the flexible tube 1, and the like.

The sealing member 6 has a convex portion 6a and a concave portion 6b.
Is provided so that air can be evacuated from the concave portion 5a formed in the metal tube 5 in the manufacturing process described later, and the covering member 7 filling the concave portion 5a of the metal tube 5 is provided.
It is necessary to select an air-impermeable material (for example, synthetic resin or rubber) for the sealing material 6. It is not always necessary to select a string-like sealing material 6 by bundling a plurality of hardly threaded synthetic resin threads or cotton threads. When the flexible tube 1 is bent by using a sealing material 6 made of elastic rubber or the like, the protrusion 6
The compression of “a” reaches the concave portion 6b, and the compression deformation can be dispersed, thereby preventing the flexible tube 1 from being damaged.

Next, the outer peripheral surface of the metal tube 5 is covered with a covering member 7 such as a synthetic resin by a resin extruder. Specifically, as shown in FIG. 2C, the inside of the metal tube 5 is pulled out from the die 17 through a vacuum pump (not shown) while maintaining an appropriate negative pressure state, while the resin melting (not shown) is performed. The resin melted in the portion squirts onto the outer periphery of the metal tube 5 via the conduit 16, and the covering member 7 has a protrusion 7d (L3 =
0.3 to 1.2 mm) and a slight recess 7b is formed on the outer peripheral surface.

That is, the conventional flexible tube 1A (FIG. 4A)
Is filled with the covering member 7 over the entire concave portion 5a of the metal tube, and the covering member 7 in the flexible tube 1 controls the negative pressure in the metal tube 5 so that the concave portion 5a Can be filled in a state in which a projection (L3) having a depth (L3) forming a space is formed in the lower part and a concave portion 7b having a uniform and small depth is formed on the outer periphery. As a result, when the flexible tube 1 is bent, uniform wrinkles are formed inside the flexible tube 1 and the movable characteristics (a state in which the flexible tube 1 does not return to the original state after being bent) are improved. That is, the conventional flexible pipe 1B (FIG. 7)
(A) The covering member 7 has a projection 7d formed in the recess 5a.
When the flexible pipe 1B is curved, the flexible pipe 1
Inside B, the protrusion 7d remains in the concave portion 5a of the metal tube (see the point X), so that the curvature increases. However, since the protrusion 7d formed in the concave portion 5a of the flexible tube 1 (FIG. 3A) is shallow, when the flexible tube 1 is curved, the protrusion 7d is formed inside the flexible tube 1 inside. Since the metal tube 5 projects from the concave portion 5a (see the point Y), the metal tube 5 is curved with the same radius of curvature, and the curvature (curvature radius R) can be reduced.

When an air-impermeable material is used for the sealing member 6, a material having a convex portion 6a and a concave portion 6b is used, so that the concave portion 5a of the metal tube and the inside of the metal tube are formed. Since the predetermined negative pressure of the concave portion 5a of the metal tube can be stably obtained by communicating with the convex portion 6a and the concave portion 6b, the depth (L3) of the protrusion 7d formed by the covering member 7 is the same. It can be formed in a state. Also, the depth (L3) of the protrusion 7d
Can be easily changed by controlling the negative pressure in the metal tube 5, so that it can be appropriately selected according to the intended use. In addition, the sealing material 6
When selecting a bundle of cotton yarn or the like that is air-permeable and hardly twisted, a negative pressure in the concave portion 5a of the metal tube can be stably obtained through the air-permeable seal material 6. It is not necessary to provide the convex portion 6a and the concave portion 6b.

When the covering member 7 forms a protrusion 7d (L3) to the extent that it does not come off in the recess 5a of the metal tube, the flexible tube 1 having the above structure is bent (FIG. 3).
(A)), the radius of curvature can be reduced, and since the shape of the sealing material 6 is composed of the convex portions 6a and the concave portions 6b, stress can be dispersed and breakage can be prevented. An effect also occurs on wear. The same applies to a case where a breathable cotton yarn is used for the sealing material 6.

As shown in FIG. 3 (B), when the packing 9 is attached to the end of the flexible tube 1 having the above-described structure and tightened by the cap nut 10a attached to the connector 10 for connecting the device, the outer peripheral surface is obtained. Since the recessed portion 7b is slightly uneven, waterproofness can be exhibited. In addition, each part etc. of the said structure can be suitably selected according to the purpose of use, and can comprise a flexible tube.

[0020]

According to the first aspect of the present invention, since the flexible tube has a shape in which the sealing material has air permeability such that a convex portion and a concave portion are formed.
The depth at which the covering member is filled in the concave portion of the metal tube can be easily changed. In the flexible pipe according to the second aspect, the radius of curvature can be reduced when the flexible pipe is curved by forming a protrusion that does not allow the covering member to come off in the concave portion of the metal tube. In addition, the flexible pipe of claim 3 uses a bundle of air-permeable yarns for the sealing material.
By forming a protrusion that does not allow the covering member to come off in the concave portion of the metal tube, it is possible to reduce the radius of curvature when curved. In the method for manufacturing a flexible tube according to claim 4, the negative pressure of the concave portion of the metal tube can be maintained at a predetermined pressure by using a sealing material having air permeability.
The covering member can be formed with a protrusion that does not come off in the concave portion of the metal tube, and when curved, the radius of curvature can be reduced.

[Brief description of the drawings]

1A is a left side view of a flexible tube 1, FIG. 1B is a front sectional view, and FIG. 1C is a partially enlarged view of the front cross section.

2A is a perspective view showing a state in which a sealing material is inserted into a fitting portion of a metal tube of the flexible tube 1, FIG. 2B is a diagram showing the sealing material, and FIG. It is a key map showing the manufacturing process which covers.

3A is a front sectional view of the flexible tube 1 in a curved state, and FIG. 3B is a diagram showing a state in which the flexible tube 1 is connected to a connector.

4A is a left side view, FIG. 4B is a front sectional view, and FIG. 4C is a partially enlarged view of a front sectional view of a conventional flexible pipe 1A.

5A is a front sectional view of a flexible tube 1A in a curved state, and FIG. 5B is a diagram showing a state in which the flexible tube 1A is connected to a connector.

6A is a left side view 6, FIG. 6B is a front sectional view, and FIG. 6C is a partially enlarged view of the front cross section of the conventional flexible tube 1B.

FIG. 7A is a front sectional view showing a state in which a flexible tube 1B is curved, and FIG. 7B is a diagram showing a state in which the flexible tube 1B is connected to a connector.

8 (A) is a left side view, FIG. 8 (B) is a front sectional view, and FIG. 8 (C) is a partial enlarged view of a front sectional view of a conventional flexible pipe 1C.

FIG. 9 is a diagram showing a front cross section of a state in which a flexible tube 1C is curved.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 1A, 1B, 1C Flexible tube 2 Metal plate 3 Spiral groove 5 Metal tube 5a Concave portion of metal tube 6 Sealing material 6a Convex portion 6b Concave portion 7 Coating member 7a Outer peripheral surface 7b Concave portion 7c Wrinkle 7d Projection

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) // B29K 105: 08 B29K 105: 08 105: 22 105: 22 B29L 23:00 B29L 23:00 F-term (reference) 3H111 AA02 BA01 CB03 CB23 CB30 DA26 EA04 4F207 AD03 AD12 AD15 AG08 KA01 KA17 KB18 KB20 KL58 5G357 DA06 DB01 DC11 DD01 DD05 DD10 DD16 DG06 5G369 AA19 BA04 DC04 DC06 EA02

Claims (4)

[Claims] 1. A flexible metal tube having a metal plate having an S-shaped cross section and a concave / convex portion formed on an outer peripheral surface while a sealing material is inserted into the mating portion. A flexible tube characterized in that the convex portion and the concave portion are formed in a string shape alternately. 2. The flexible tube according to claim 1, wherein the projecting portion is formed by a covering member for covering the outer periphery of the metal tube to such an extent that the projecting portion does not fall out of the concave portion of the metal tube. 3. A flexible metal tube having a metal plate having an S-shaped cross section and a concave / convex portion formed on an outer peripheral surface while a sealing material is inserted into the mating portion. A flexible tube made of a bundle of yarns, the covering member covering an outer periphery of the metal tube, wherein a protrusion is formed to such an extent that the protrusion does not fall out of a concave portion of the metal tube. 4. A metal tube having an S-shaped cross section, and a metal tube having an uneven portion formed on an outer peripheral surface while a gas-permeable sealing material is inserted into the mating portion. A method for manufacturing a flexible tube, comprising: covering the outer periphery of a metal tube with a covering member while forming a predetermined negative pressure;