JPH07148815A - Production of metal wire coil/plastic tube composite sheath - Google Patents

Abstract

PURPOSE:To obtain a sheath having a durability for a long-term service as a protective sheath, e.g. for a cable for suspending a bridge girder by a method wherein a plastic band is fitted over and along a metal wire coil so that the inner peripheral part of the metal wire coil is exposed, and the composite tube formed by bonding the plastic band is externally coated with a plastic. CONSTITUTION:A plastic band 2 is spirally fitted over and along a metal wire coil 1. The metal wire coil 1 is fitted in a coil fitting groove 25 formed on the inner peripheral surface of the band so that the inner peripheral part of the coil is exposed outside the groove. The adjacent band edges of the plastic band spirally fitted are bonded to each other. The outer peripheral surface of the tube is extrusion-coated with a plastic jacket 4. in this manner, a metal wire coil/plastic tube composite sheath 5 is produced. When the composite sheath 5 is pulled so as to be fitted over the outer peripheral surface of a cable, the metal wire coil exposed and projected on the inner peripheral surface of the sheath comes into contact with the outer peripheral surface of the cable. In this manner, a frictional resistance is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a metal wire coil / plastic tube composite sheath for covering steel wires suspended from a bridge.

[0002]

2. Description of the Related Art Steel ropes for suspending a long bridge or the like bridged over the sea are provided in large numbers in order to withstand a large suspension load and to have a large tensile strength and to be suspended between supporting columns with a predetermined sag. A large-diameter steel rope is formed by bundling the strands of the steel wire of the above, but this steel rope is constantly exposed to sea breeze, and if the outer surface of the steel wire is bare, the wire will be corroded. It is necessary to protect the steel rope from corrosion, as it may lead to a decrease in tensile strength. When this anticorrosion layer is formed by applying anticorrosion paint to the surface of the steel rope, the steel rope that suspends the bridge etc. is constantly exposed to a relatively strong wind, and the anticorrosion coating film fouls and peels off in a short period of time. Repainting must be done on a regular basis, which makes repainting difficult and expensive due to work in high places. In order to prevent the corrosion from being used for a long period of time, a method for covering the outer circumference of the steel rope with a plastic sheath is used.

[0003]

In the case of covering the outer circumference of the large-diameter steel rope with a plastic sheath, either a method of directly winding a plastic tape on the outer circumference of the steel rope or a method of extruding and covering the plastic sheath is used. As for the method, since the steel rope has a large diameter, the device becomes large and the cost becomes high. For this reason, if the hollow plastic sheath is pulled over the outer circumference of the large-diameter steel rope to cover it, the friction between the outer peripheral surface of the steel wire group and the inner peripheral surface of the plastic sheath is large. There is a problem that it is difficult to pull in the work.

The present invention solves the above-mentioned problems and provides a method for producing a metal wire coil / plastic tube composite sheath which can be easily covered on the outer circumference of a large-diameter steel rope or the like for suspending a bridge or the like. The purpose is to do.

[0005]

In order to achieve the above-mentioned object, a method for manufacturing a metal wire coil / plastic tube composite sheath of the present invention is a method for continuously forming a metal wire coil 1 by spirally molding a metal wire. First process (A)
And a plastic strip 2 on the outer circumference of the metal filament coil 1.
The coil wire 1 is inserted into the coil fitting groove 25 on the inner circumference of the spiral plastic strip 2 by
The second step (B) in which the inner peripheral side portion of the coil is exposed to the outside of the groove 25 and fitted, and the adjacent edge of the adjacent spiral plastic strip 2 attached to the outer periphery of the metal linear coil 1 described above. Third step of joining metal wires coil 1 and composite tube 3 of spiral plastic strip 2 by joining
(C) and the fourth step (D) of extruding and covering the outer circumference of the metal wire coil / spiral-shaped plastic strip composite tube 3 with the plastic jacket 4,
The method is characterized by producing a plastic tube composite sheath 5.

[0006]

The metal linear coil 1 with the plastic strip 2 reinforces the hollow tubular plastic sheath from the inside. Also, by adjoining the adjacent edges of the spiral plastic strip 2 attached to the outer periphery of the metal wire coil 1, the adjacent plastic strip 2 wound in a spiral shape.
There is no separation gap between them, the hollow tube shape is maintained, and the outer periphery of the hollow tube can be uniformly coated with the plastic jacket 4.

When the metal wire coil / plastic tube composite sheath 5 is pulled in so as to cover the outer circumference of the steel rope, the friction resistance is large if the inner circumferential surface of the plastic comes into direct contact with the outer circumferential surface of the steel rope.
The inner peripheral side portion of the metal wire coil is exposed and protrudes from the lower surface 23 of 22, and the exposed protruding metal wire portion comes into contact with the outer peripheral surface of the steel rope. This makes it easier to pull the outer circumference of the large diameter steel rope and cover it.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.
As shown in FIG. 1, in the method for producing a metal wire coil / plastic tube composite sheath of the present invention, in the metal wire coil continuous feeding step (A) of the first step, the metal wire coil 1 is continuously fed. It is molded and sent out. In the plastic strip / metal filament coil splicing and fitting step (B) in the second step, the plastic strip 2 is spirally attached to the outer periphery of the metal filament coil 1 to form the spiral plastic strip. The coil wire 1 is fitted in the coil fitting groove 25 of the wire 2 with the inner circumferential side of the coil exposed outside the groove 25. In the plastic strip adjacent edge joining step (C) of the third step, each adjacent edge of the plastic strip 2 is attached to the outer periphery of the metal strip coil 1 and the metal strip coil 1 and the spiral shape are joined. The composite tube 3 of plastic strip 2 is formed. 4th process, plastic coating extrusion coating process (D)
In the above, the metal wire coil / plastic tube composite sheath 5 is formed by extrusion-coating the outer circumference of the metal wire coil / plastic strip composite tube 3 with a plastic jacket 4.
To manufacture.

In the metal wire coil continuous feeding step (A) of the first step, the metal wire 11 is continuously fed from the metal wire drum 12 to the spiral forming part 10 as shown in FIG. In the spiral forming part 10, while continuously forming the metal wire 11 in a spiral shape, the metal wire coil 1 is formed by winding it around the guide shaft 13 having a circular cross section at a pitch P as shown in FIG. , This metal wire coil 1 to the guide shaft 13
While continuously rotating around, the second continuous process shown in FIG. 1 is continuously fed in the direction of the arrow toward the plastic strip / metal linear coil splicing and fitting process (B).

In the plastic strip / metal strip coil splicing and fitting step (B) shown in FIG. 1 of the second step, the plastic strip extruder 33 extrudes the strip 2 of low density polyethylene or other plastic. It is molded and sent to the plastic strip splicing fitting part 30 which is composed of the plastic strip splicing fitting part 31 and the plastic strip fitting splicing part 32. The plastic strip 2 is spirally attached to the outer circumference of the metal strip coil 1 to be fed, and the metal strip coil 1 is inserted into the coil strip 23 of the plastic strip 2 at the plastic strip fitting portion 32. The inner circumference side of the coil is exposed to the outside of the groove 25, and is fitted and fitted.

The cross-sectional shape of the plastic strip 2 is
As shown in FIG. 3 showing the end face of the plastic strip 2 of the first embodiment, a central trapezoidal ridge portion 22 is provided which projects in the center of the lower surface of the central strip plate portion 21 and extends in the longitudinal direction.
A coil fitting groove 25, which is a circular groove having a diameter φ, into which the wire of the metal wire coil 1 can be fitted is provided continuously in the longitudinal direction at the center of the lower surface 23 of the coil fitting wire 25. Is the bottom of the trapezoidal ridge
23 is provided with a narrow opening 24 opening in the longitudinal direction, and the opening width S of this narrow opening 24 is smaller than the diameter φ of the circular groove of the coil fitting groove 25, and the metal wire coil 1 is made of metal. It is formed with an opening width into which a wire can be fitted. Further, on both side edges of the central strip portion 21, a lower joining edge piece portion 26 having a thickness d of 1/2 of the strip portion 21 is provided in the longitudinal direction on the left side edge thereof, and the same d height is provided on the upper side thereof. Upper side step portion 27 is formed, an upper joining edge piece portion 28 having a thickness d of ½ of the strip plate portion 21 is provided in the longitudinal direction on the right side edge, and a lower portion of the same height d is provided on the lower side thereof. The side step portion 29 is formed, and the width W1 of the lower joint edge piece portion 26 and the width W2 of the upper joint edge piece portion 28 are formed to have the same width. 27a is a corner edge of the upper step portion 27, and 28a is a corner edge of the upper joining edge piece portion 28. One example of this plastic strip 2 is the thickness of the joint edge pieces 26, 28 on both sides and the height d of the step portions 27, 29 d = 1 mm, both joint edge pieces 2
Width W1, W2 of 6, 28 = 5 mm, width W of plastic strip 2 =
25 mm, height H of trapezoidal ridge 22 = 3 mm, height from bottom surface 23 of trapezoidal ridge 22 to center of circular groove of coil fitting groove 25
h0 = 1mm, diameter of circular groove of coil fitting groove 25 = 2.9
mm, and the opening width S of the narrow opening 24 is about 2 mm. The diameter r of the wire of the metal wire coil 1 is determined by the above-mentioned coil fitting groove.
It is a diameter that can fit within 25.

The plastic strip attachment portion 31 of the plastic strip attachment fitting portion 30 to which the plastic strip 2 extruded by the extruder 33 having the above-mentioned shape is fed is shown in FIG. As described above, the plastic strip 2 is spirally attached to the outer periphery of the metal linear coil 1. The metal linear coil 1 molded in the first step and wound around the guide shaft 13 and fed in the direction of the arrow while rotating is the guide shaft 13
Around the circumference of the metal wire coil 1 is fed by being positioned at a constant pitch by a guide groove or other suitable positioning means, and along the outer periphery of the metal wire coil 1, the plastic strip 2 is fitted into the central trapezoidal ridge 22 by coil fitting. The compound groove 25 is fed so as to face the metal wire coil 1. Reference numeral 31a is an example of the guide means for the plastic strip 2. The plastic strip 2 fed along the outer periphery of the metal linear coil 1 has the guide 31a which allows the coil fitting groove 25 of the plastic strip 2 to be made of metal. The filament coil 1 is positioned so as to properly face and abut the outer surface of the filament coil 1.

As described above, in the plastic strip abutting portion 31, the coil strip groove 25 of the plastic strip 2 is made to face the outer periphery of the metal linear coil 1 and is spirally attached to the plastic strip 2 and the metal. In the wire coil 1, the coil fitting groove 25 is fitted into the metal wire coil 1 at the plastic band fitting portion 32 of the plastic band splicing fitting portion 30. As shown in FIG. 5, the plastic strip fitting portion 32 is provided with means for guiding the plastic strip 2, for example, a pressing guide plate 32a, and the like, and is provided in the positioning means for the circumferential surface of the guide shaft 13, for example, the positioning guide groove 13a. Metal wire coil 1
Of the trapezoidal ridge 22 of the plastic strip 2 while the plastic strip 2 having the central trapezoidal ridge 22 attached to the outer periphery of the metal strip coil 1 is guided by the pressing guide plate 32a. By pressing the narrow opening 24 of the coil fitting groove 25 opening on the lower surface against the outer circumference of the wire of the metal wire coil 1, the inner circumference of the coil is exposed to the outside of the narrow opening 24 and the trapezoidal ridge 22 is formed. The metal wire coil 1 is fitted into the coil fitting groove 25 while protruding from the lower surface 23.

As shown in FIG. 6, the wire of the metal wire coil 1 fitted in the coil fitting groove 25 as described above has at least 2/3 or more of the thickness of the wire. Mating groove
It is fitted in 25 and exposed in the narrow opening 24, and trapezoidal ridge 22
The lower surface 23 is slightly projected downward. Its narrow opening
An example of the exposed protrusion height h1 of the wire of the metal wire coil 1 at 24 is the height h0 = 1 mm from the lower surface 23 of the trapezoidal ridge 22 to the center of the circular groove of the coil fitting groove 25, coil fitting. When the diameter φ of the circular groove of the compound groove 25 is 2.9 mm, h1≈1.4 to 1.5 mm.

As described above, the composite spiral strip of the metal strip coil 1 and the spiral plastic strip 2 fitted and joined in the coil fitting slot 25 is rotated along the peripheral surface of the guide shaft 13. While advancing in the direction of the arrow in FIG. 1, it is fed to the adjacent plastic strip edge joining portion 40 in the next plastic strip adjacent edge joining step (C) of the third step. At this adjacent plastic strip edge joint 40, as shown in FIG. 7, the adjacent plastic strips 2 of the composite spiral strip that are successively and repeatedly fed on the peripheral surface of the guide shaft 13 are fed.
The joining edge pieces of the respective side edges are overlapped and joined. This joining is performed, for example, on the peripheral surface of the guide shaft 13 while rotating with the metal linear coil 1 on the lower side step portion 29 of the right side edge of the spiral plastic strip 2A (29 is shown in FIG. 3).
Place the lower joint edge piece 26 on the left side edge of the spiral plastic strip 2B following to the upper joint edge piece 28 on the right side edge of the preceding strip 2A and the lower side edge of the trailing strip 2B. The joining edge piece portion 26 is overlapped, and similarly, the upper joining edge piece portion 28 on the right side edge of the spiral plastic strip 2B and the lower joining edge piece portion 26 on the left side edge of the spiral shaped plastic strip 2C following this are overlapped. Then, the joining device 41 joins the overlapping portions of the upper and lower joining edge pieces of the adjacent plastic strips which are sequentially overlapped in this way. The joining device 41 uses a fusion device that heats and fuses the plastic plate pieces by heating with infrared rays or appropriate electric heating, for example, and performs spot heating fusion or continuous joining of the overlapping portions of the joining pieces. The adjacent edge joints 268 are formed by heat fusion, and an adhesive may be applied between the upper and lower joint edge pieces 28 and 26 as necessary. In this way, the adjacent edges of the adjacent plastic strips 2 are joined together to form a composite tube 3 of metal filament coil / spiral plastic strip.

As described above, the metal wire coil / spiral-shaped plastic strip composite tube 3 in which the adjacent plastic strips 2 are joined at the adjoining edge joining portion 268 in the third step is as follows:
The circumferential surface of the guide shaft 13 is sent to the plastic jacket extrusion section 50 in the next step of the plastic jacket extrusion coating step (D) shown in FIG. 1, and the extruder 51 causes the metal wire coil coil spiral. The outer periphery of the plastic strip composite tube 3 is extruded and coated with an extrusion-coated plastic jacket 4 such as low-density polyethylene with a coating thickness of about 3 mm and an outer diameter of 76 mm to 115 mm. FIG. 8 is a sectional view showing the metal wire coil / plastic tube composite sheath 5 for bridge suspended steel rope of the present invention manufactured as described above. As described above, the metal wire coil / plastic tube composite sheath 5 in which the outermost layer is extruded and covered with the plastic jacket 4 is taken by an appropriate take-up means such as a caterpillar take-up device, and cut into a fixed length.

The metal wire coil / plastic tube composite sheath 5 manufactured as described above is drawn over the outer circumference of the steel rope in which the steel wire group for suspending the bridge is bundled. When the inner surface of the plastic strip on the inner circumference of the hollow sheath comes into direct contact with the outer surface of the steel strip when the steel strip is pulled over the outer periphery of the steel strip, the friction resistance increases, but the lower surface 23 of the trapezoidal ridge portion 22 of the plastic strip 2 is increased. The metal wire coil 1 is exposed and protrudes at the end of the wire, and the exposed metal wire coil portion comes into contact with the outer peripheral surface of the steel cord. The outer circumference of the steel rope can be easily pulled in and covered.

FIG. 9 shows a second embodiment of the plastic strip 2, and the same reference numerals as in FIG. 3 indicate the same parts. 22 is a central trapezoidal ridge, 23 is its lower surface, 25 is a coil fitting groove,
24 is a narrow opening of the coil fitting groove 25, 26 and 28 are joint edge pieces on both side edges, and 27 and 29 are steps. In the plastic strip 2 of the second embodiment, the left edge joining edge piece portion 26 is provided on the upper side, the right edge joining edge piece portion 28 is provided on the lower side, and the left edge upper joining edge piece portion 26 is provided. On the lower surface, a short shaft 26b protruding downward
A hemispherical locking head 26a is provided at the lower end of the locking head 26a, and an upper opening of a diameter at which the locking head 26a is fitted and locked on the upper surface of the lower joining edge piece 28 of the right side edge. Stop hole 28a and its small diameter opening
It is equipped with 28b.

As described above, the upper and lower joint edge pieces 26, 28 on both the left and right sides are provided with the locking head 26a and the locking hole 28a.
The plastic strip 2 of the embodiment of the present invention is the same as the plastic strip attachment portion 31 of the plastic strip attachment attachment portion 30 in the plastic strip / metal wire coil attachment attachment step (B) of the second step. To fit the metal wire coil 1 in the coil fitting groove 23 along the outer circumference of the metal wire coil 1 in the plastic wire fitting portion 32 is the same as that of the plastic wire band 2 of the first embodiment. Similar to the case, in the adjacent plastic strip edge joining portion 40 of the above-mentioned plastic strip adjacent edge joining step (C) of the third step, the lower joining edge piece portion 28 of the right side edge of the preceding plastic strip is used. The upper joining edge piece 26 on the left side edge of the trailing plastic strip is superposed on the above, and the downwardly projecting locking head 26a is fitted into the upwardly opening locking hole 28a. Adjacent joint edge between strip and trailing plastic strip Joining the parts. In this manner, the outer circumference of the composite tube 3 of the metal wire coil / plastic strip in which the adjacent joint edge pieces are thus joined is extruded and covered with the plastic jacket 4 in the next plastic jacket extrusion coating step (D) of the fourth step. The metal wire coil / plastic tube composite sheath 5 is constructed and cut to a fixed length, as in the case of the plastic strip 2 of the first embodiment.

In the embodiment of the method for manufacturing the metal wire coil / plastic tube composite sheath of the present invention shown in FIG. 1, the metal wire coil continuous feeding step (A) of the first step, the second step
Plastic strip / metal wire coil splicing and fitting process
(B), 3rd process plastic strip adjacent edge joining process (C)
, The plastic coating extrusion coating step (D) of the fourth step,
Although the steps are continuous, appropriate steps may be discontinuous if necessary, for example, the first step and the second step or the third step and the fourth step may be discontinuous.

[0021]

As described above, according to the method of the present invention, a plastic strip is attached to a metal linear coil to expose an inner peripheral side portion of the metal linear coil in a coil fitting linear groove on the inner periphery of the strip. Since the outer circumference of the composite tube in which the adjacent edges of the plastic strips are joined is extruded and covered with a plastic jacket to produce a metal wire coil / plastic tube composite sheath, a hollow tubular plastic sheath A uniform plastic jacket can be extrusion coated on the outer periphery of the
A composite sheath that can withstand long-term use can be obtained as a protective sheath for steel ropes for suspending bridges and the like.

Further, when the metal wire coil / plastic tube composite sheath is pulled in so as to cover the outer circumference of the steel rope, the metal wire coil protruding and exposed on the inner circumference of the composite sheath comes into contact with the outer peripheral surface of the steel rope. The frictional resistance at the time of pulling in becomes small and it becomes slippery, and it becomes possible to easily pull in and cover the outer circumference of a large diameter steel rope.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the method of the present invention.

FIG. 2 is a diagram showing a metal wire coil continuous feeding step in the first step.

FIG. 3 is an end view of a first embodiment of a plastic strip.

FIG. 4 is an explanatory diagram of a plastic strip splicing part in the second step.

FIG. 5 is an explanatory view of a plastic strip fitting portion in the second step.

FIG. 6 is a view showing a metal wire coil coil fitting state of a plastic band.

FIG. 7 is an explanatory diagram of a plastic strip adjacent edge joining step in the third step.

FIG. 8 is a partial sectional view of a metal wire coil / plastic tube composite sheath of the present invention.

FIG. 9 is a sectional view of a second embodiment of a plastic strip.

[Explanation of symbols]

1: Metal wire coil 2: Plastic strip 3: Metal wire coil / spiral-shaped plastic strip composite tube 4: Plastic jacket 5: Metal wire coil / plastic tube composite sheath 25: Coil fitting strip of plastic strip Groove 268: Strip edge joining part of plastic strip A: First step B: Second step C: Third step D: Fourth step

Claims (1)

[Claims] 1. A first step of continuously forming a metal filament coil by spirally molding a metal filament coil, and adding a plastic ribbon spirally around the outer periphery of the metal filament coil. The second step of fitting the coil wire in the coil fitting groove of the strip by exposing the inner circumference of the coil to the outside of the groove and the adjacent edge of each adjacent spiral plastic strip are joined. A third step of forming a metal wire coil / spiral-shaped plastic strip composite tube with a metal wire coil / spiral-shaped plastic strip composite tube, and a fourth step of extruding and coating a plastic jacket on the outer circumference of the metal wire coil / spiral-shaped plastic strip composite tube. A method of manufacturing a metal wire coil / plastic tube composite sheath comprising: