JP3756878B2 - Covered wire rope - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention mainly relates to a covered wire rope suitable as a moving cable for a crane or an elevator.
[0002]
[Prior art]
In moving cables used in cranes, elevators, etc., the rope is moved or wound up through the sheave, so that it is subjected to severe conditions in which tension and bending act over the entire length.
Conventionally, as a rope for such a rope, a plurality of side strands are arranged on the outer periphery of a core rope made of a fiber core or a metal core (strand, rope) as defined in JIS / G / 3525 or 3546. In this case, a twisted structure was used.
[0003]
For this reason, a high surface pressure is generated at the contact surface between the core rope and the side strand, and friction between the core rope and the side strand occurs due to bending, and the surface pressure between the side strands increases due to a decrease in diameter due to abrasion of the core rope. There was a problem that the contact surface wear of each strand and the breakage of the strands constituting the core rope and the side strand occurred.
As a countermeasure, a rope for moving cords in which a thermoplastic resin layer is interposed between the core rope and the side strand has been proposed.
[0004]
[Problems to be solved by the invention]
However, in this prior art rope for ropes, contact between the core rope and the side strands is prevented, but it is difficult to keep the distance between the side strands, so that the side strands come into contact with each other and wear occurs. Easy to use, since the sheave and side strands always touch the metal and slide relative to each other, usually the soft sheave wears, and it takes a lot of time and labor to replace expensive sheaves. The friction coefficient changes and slip occurs between the sheave and the rope, making it difficult for the rotation of the sheave to be transmitted accurately to the rope, reducing the accuracy of position control of the object connected to the rope, and special groove processing as a sheave There was a problem in that it was necessary to use a product that had been subjected to.
[0005]
The present invention has been made to solve the above-described problems. The object of the present invention is to provide each wear between the core rope and the outer strand and between the adjacent outer strands, and between the sheave and the outer strand. An object of the present invention is to provide a covered wire rope that can realize good frictional contact (drive force transmission) between the sheave and the entire rope while preventing wear due to metal touch, and is easy to manufacture.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention is a rope in which a plurality of side strands are arranged and twisted on the outer periphery of a core rope, and an outer layer coating surrounding the side strands is provided, and the upper layer of each side strand is It is formed by twisting together a plurality of strands and a resin wire having a reinforcing wire in the center and having a diameter larger than the strand diameter. A gap is formed between the ropes and between the side strands, and the outer layer coating resin is press-fitted and filled through these gaps.
[0007]
The present invention is also characterized in that it is a covered rope made in the following process.
Prepare a plurality of strands and one or more resin wires having a reinforcing wire in the center and a diameter larger than the strands, arrange the strands and the resin wires on the inner layer, and twist them together. A step of producing convex side strands, a step of arranging a plurality of side strands having one or more of these resin wires on the outer periphery of the core rope, twisting the whole, and producing a bare rope, and an extruder A step of press-fitting and filling between the side strands and the side strands with the synthetic resin melted by passing the raw rope through the space between the side strands formed in the presence of the resin wire.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings.
1 to 6 show a first embodiment of a covered wire rope according to the present invention.
1 and 2, reference numeral 1 denotes a core rope, which is provided with a synthetic resin coating layer 1b on the outer periphery of a core rope body 1a formed by twisting strands or strands. The configuration of the core rope body is arbitrary, but in this example, it has a 1 × 7 structure in which six side strands 102 are arranged around the central strand 101 and twisted.
[0009]
Reference numeral 2 denotes a plurality of (six in the drawing) side strands arranged around the core rope 1 and twisted. 3 is a synthetic resinous outer layer coating (overall coating) applied so as to enclose the side strand 2, and due to the special structure of the side strand 2, which will be described in detail later, between adjacent side strands 2, 2, and The side strand 2 and the core rope 1 are press-fitted and joined.
[0010]
300 is a filling portion between the side strands 2 and 2, 301 is a filling portion between the side strand 2 and the core rope 1, and 302 is a cylindrical outer layer portion surrounding the circumscribed circle of the side strand 2. The portion 302 is integrally joined to the filling portion 301 as an inner layer by a substantially radial filling portion 300 extending in the radial direction. The filling portion 301 is integrally joined to the synthetic resin coating layer 1b of the core rope 1.
[0011]
The side strand 2 may have an arbitrary configuration, but in this example, it is a 1 × 7 structure in which six upper-layer strands are arranged and twisted around a central strand 201 as shown in FIG. One or more (two in this example) are the resin wires 4 having a diameter larger than the diameter of the upper layer strand 201.
[0012]
As the strands 201, 202, 101, 102, steel strands are used. A steel wire having a tensile strength of 240 kg / cm ² or more is used when high strength is required for the rope. Such a steel wire is obtained by drawing a raw material wire having a carbon content of 0.70 wt% or more. The strand includes those having a thin corrosion-resistant coating such as zinc plating or zinc / aluminum alloy plating on the surface.
[0013]
The resin wire 4 may be entirely made of a synthetic resin, but in order to ensure appropriate strength when a strand is formed, a reinforcing wire 4a is provided at the center as shown in FIGS. 3 (a) and 3 (b). And a synthetic resin layer 4b is provided therearound. The synthetic resin layer 4b can be obtained continuously by squeezing the reinforcing wire 4a through a molten resin bath or by passing it through a die of a resin extruder.
[0014]
The number of the reinforcing wires 4a may be one as shown in FIG. 3A, or a plurality of the reinforcing wires 4a may be arranged close to each other as shown in FIG. 3B. As the material, steel strands similar to those of the strands 201, 202, 101, 102 are usually used, but synthetic fibers may be used instead. The thickness of the reinforcing wire 4a may be the same as that of the strand 201 or may be appropriately thin.
[0015]
The synthetic fiber is preferably a high-strength low-elongation fiber selected from aramid, ultrahigh molecular weight polyethylene, wholly aromatic polyester, and the like. A large number of yarns made of such fibers are collected into a bundle, and the bundle is aligned in parallel. Or made by twisting with long leads.
[0016]
As the resin of the synthetic resin layer 4b, polyvinyl chloride, nylon, polyester, polyethylene, polypropylene, a copolymer of these resins, and the like can be used. From the viewpoint of obtaining good adhesion and integrity with the resin of the layer 1b and the resin of the outer layer coating 3, it is preferably a thermoplastic resin having the same or similar properties as the resin of the core rope coating layer 1b and the resin of the outer layer coating 3. .
[0017]
Specifically, in addition to wear resistance, weather resistance, and flexibility (stress crack resistance), the outer layer coating 3 has moderate elasticity and a relatively high friction coefficient in order to adjust the friction coefficient with the sheave. For example, polyurethane resins and ether polyurethane elastomers are used as these resins.
[0018]
The diameter of the resin wire 4 needs to be 101% or more with respect to the upper strand 202. If it is less than this, since the resin wire 4 protrudes very little from the strand circumscribed circle of the side strand, it is not possible to form a gap large enough to assist the penetration of the resin for the outer layer between the adjacent side strands 2 and 2. It is.
The upper limit of the ratio to the upper-layer wire 202 is about 110%. If the diameter ratio is larger than this, it will be difficult to fit between the strands 202 constituting the upper layer, and it will float and come off, or the gap formed between the side strands 2 and 2 will become too large, This is because the steel filling rate is reduced.
[0019]
When there are a plurality of the resin wires 4, they are preferably arranged at positions spaced apart from each other on the circumference, preferably symmetrically, and twisted together with the upper-layer wires 202 at a predetermined pitch.
Accordingly, the resin wire 4 has a spiral shape in the longitudinal direction of the strand as shown in FIG. 4A, and the resin wire 4 has a relatively large diameter with respect to the upper strand 202, so that FIG. ), The side strand 2 has a form in which a circumscribed circle D2 having a large diameter of the resin wire 4 is surrounded by a circumscribed circle D1 composed of the element wires 202 for the upper layer.
[0020]
A plurality of such side strands 2 are arranged around the core rope 1 and twisted to form a raw rope A as shown in FIG. The strand twist direction and the rope twist direction are preferably opposite. For example, when the strand twist direction is the S direction, the rope twist direction is the Z direction.
In addition, the position on the circumference of the resin wire 4 in each side strand 2 and 2 is better to be random as illustrated in FIG. This is also advantageous in terms of facilitating rope production.
[0021]
In such a rope A, an appropriate gap S1 is created between the side strands 2 and 2 by the circumscribed circle D2 of the helical resin wire 4, and at the same time, a spiral shape is formed between the side strand 2 and the core rope 1. Appropriate gaps S <b> 2 are created substantially evenly by the circumscribed circle D <b> 2 of the resin wire 4.
[0022]
In this state, the raw rope A is washed, the whole is preheated to around 100 ° C., and then the outer layer coating 3 is applied. This is normally performed continuously by passing the raw rope A through a die 90 of an extruder 9 that press-extrudes the molten resin 30 as shown in FIG.
At the time of the extrusion, the molten resin 30 is press-fitted into the uniform gap S1 formed between the side strands 2 and 2 as shown in FIG. 6B, and the side strand 2 communicating with the gap S1 The gap S2 between the core ropes 1 is filled and the gap is filled.
[0023]
As can be seen from FIG. 4A, an approach path similar to a spiral groove is formed between the large diameter resin wires 4 and 4. For this reason, the molten resin 30 can flow smoothly between the side strands 2 and the core ropes 1 along the approach path, and can be filled between the side strands 2. It is preferable that the number of the resin wires 4 of the side strand 2 is two or more from the point which the contact of this point and an adjacent strand increases and a clearance gap is stabilized.
[0024]
Since the resin wire 4 in each side strand 2 and 2 is heated by contact with the high-temperature molten resin 30, at least the surface of the resin layer 4b is melted, and the molten resin penetrates through the gap S1 and the gap S2. It fuse | melts with the coating layer 1b of the rope 1. FIG. That is, the resin wire 4 also becomes part of the molten resin for coating, and serves to replenish the resin from the inside of the rope.
Thus, as shown in FIG. 2, the radial osmotic resin layer 300 is securely provided between the side strands 2 and 2, and the osmotic resin layer 300 and a series of ring-shaped osmotic resin layers 301 are reliably provided between the side strand 2 and the core rope 1. Can be formed.
[0025]
Although the molten resin 30 finally covers all the strands 2, the side strands 2 have a large adhesive surface area because of the thick resin wires 4 mixed therein, and have a complicated sectional shape with large irregularities. The layer 4b is fused to the molten resin 30. Therefore, the adhesive force between the inner side portion of the cylindrical outer layer 302 completed so as to surround the side strand 2 and the side strand 2 is high, and the resistance to displacement increases.
Moreover, the outer layer 302 is integrally joined with the ring-shaped penetrating resin layer 301 between the side strand 2 and the core rope 1 by the radial penetrating resin layer 300 between the side strands 2 and 2.
[0026]
When the resin of the core rope 1, the resin of the resin wire of the side strand 2, and the outer layer resin are made of the same material, they are easily fused when heated, and the physical and chemical properties of the resin in the cross section are uniform. The coating is not torn or displaced by frictional force or shear force with the sheave.
[0027]
Since the present invention mixes the resin wires 4 in the side strands 2 to form gaps, the step of resin coating the entire side strands 2 in advance is unnecessary, and the side strands can be covered during the entire covering of the rope. The coating process is only required once, the productivity is good, and the cost can be reduced.
In addition, when the side strand 2 is pre-coated with resin, twisted with the coated core rope, and the outer periphery thereof is coated with resin, the resin is placed between the cylindrical coated side strand and the cylindrical coated core rope. Is difficult to permeate, and voids are generated, which may impair the integration of the side strands and the core rope, but the present invention eliminates such a concern. Moreover, since the steel material filling rate can be increased, the strength can be improved.
[0028]
If the thickness from the outer diameter (circumscribed circle) of the side strand 2 of the outer layer 302 is too thin, the durability is poor and the wear life is also reduced. If it is too thick, the flexibility required as a moving cord is impaired, and the rope diameter becomes thick and the strength efficiency decreases. Therefore, it is usually 1/5 or less of the rope diameter, for example, about 0.3 to 2.0 mm. preferable.
[0029]
FIG. 7 shows a second embodiment of the present invention. In this example, three resin wires 4 are arranged at equal intervals on the upper layer of the side strand 2. Only one side strand is shown in detail, and the other side strands are simplified. The other parts are the same as those in the first embodiment, and thus the same reference numerals are given to the same parts and the description thereof is omitted.
[0030]
In the present invention, the configuration of the core rope 1 and the configuration of the side strand 2 are not particularly limited. 8 to 12 show another embodiment of the present invention, in which the core rope 1 is composed of 7 × 7 IWRC. The side strand 2 has an 8 × S (17 + 2) configuration.
The side strand 2 includes an inner layer 2a in which nine thin strands 203 are arranged around a thick central strand 201 ', and seven steel strands 201 and one or more (two in the figure) around the inner layer 2a. The resin wire 4 is arranged and twisted. The resin wire 4 is arranged between the three steel strands and the four steel strands. Since the configuration of the resin wire 4, the ratio of the diameter with the steel wire, the resin to be used, the condition of the outer layer coating, the action, and the like are all the same as in the first embodiment, the description is incorporated.
[0031]
FIG. 13 shows an example in which three resin wires 4 are used, and the resin wires 4 are arranged every two steel wires 201. Since other configurations are the same as those of the first embodiment, the description is incorporated.
[0032]
The present invention is suitable for moving cables, but can also be applied to rigging of hanger ropes, cable bridges, stays, etc. for suspension bridges. When applied to these applications, the coating resin not only surrounds the side strands, but also is filled between the core ropes and the side strands through the side strands and is firmly bonded and integrated. There is no gap between the coating and the rope due to the difference in rate, and no corrosion is caused by moisture (including that caused by condensation).
[0033]
【Example】
A coated rope was manufactured by applying the present invention. Six 1 × 7 side strands were arranged and twisted around a core rope having an outer diameter of 3.0 mm, in which a 1 × 7 structure core rope body was coated with ether polyurethane (Shore hardness D scale 90).
[0034]
For each side strand, the upper two strands were resin wires. The strand is 1.00 mm in diameter, and the resin wire is 1.1 mm in diameter, which is a steel strand covered with an ether polyurethane (Shore hardness D scale 90) with an extruder. And twisted in the S direction at a twist pitch of 30 mm.
The side strands were arranged around a six-core rope, and twisted in the Z direction at a twist pitch of 80 mm to form a raw rope.
[0035]
When the raw rope was inspected, a 0.2 mm gap was evenly opened between the side strands, and a 0.1 mm gap was formed between the core rope and the side strands.
After washing the raw rope, preheat to 100 ° C and coat with ether-based polyurethane (Shore hardness D scale 90) melted to 200 ° C with an extruder to obtain a coated rope with an outer layer thickness of 1.0 mm and an outer diameter of 11 mm It was.
[0036]
As a result of cutting the coated rope and observing under a microscope, the coated resin is completely filled between adjacent side strands, and is also completely filled between the side strands and the core rope and integrated with the outer layer resin. It was.
[0037]
The obtained covering rope and the rope were pulled in the opposite direction with the jig shown in FIG. 14, and the adhesion of the covering and the rope was tested together with the comparison rope in which the outer layer strands were all steel strands without using the resin wires. did.
As a result, it was confirmed that the rope of the present invention increased by about 80% compared to the case where the resin wire was not used. As a result of measuring the resin filling rate by microscopic observation, it was confirmed that the resin filling rate was increased by about 65% compared to the case where the resin wire was not used.
[0038]
Further, an S-bending test was performed under the conditions of D (sheave diameter) / d (rope diameter): 20, safety factor: 10, and use of a round groove sheave, and the number of occurrences of coating resin abnormality was examined. As a result, when the resin wire was not used, the coating slip occurred at 50000 cycles, but the rope of the present invention did not cause any abnormality even at 150,000 cycles.
[0039]
When the number of resin wires used was changed to one, the adhesive strength between the coating and the rope was confirmed to increase by about 50% compared to the case where no resin wires were used.
Further, the resin filling rate in the rope was increased by 40% in the case of one resin wire and 80% in the case of three resin wires.
As for the number of coating resin abnormality occurrences, no abnormality occurred even in the case of one resin wire or 100,000 cycles.
[0040]
【The invention's effect】
According to the first aspect of the present invention described above, since the side strand 2 has the thick resin wire 4 in the upper layer, the side strand 2 is arranged around the core rope 1 and twisted in an adjacent state. A uniform gap is reliably formed between the strands 2 and 2, and a uniform gap is also reliably formed between the side strands 2 and the core rope 1, so that the outer layer resin is placed between the adjacent side strands 2 and 2. The side strand 2 and the core rope 1 can be reliably infiltrated. In addition, the presence of the resin wire 4 makes the side strand have an irregularly shaped cross section, and the resin layer 4b of the resin wire 4 melts and fuses with the resin of the outer layer, so that the integrity with the coating resin is excellent. It becomes a thing. These prevent wear due to contact between the core rope and the outer strand, wear due to contact between adjacent outer strands, wear due to metal touch between the sheave and the outer strand, and good driving force of the sheave and the entire rope. Transmission can be realized. In addition, since the side strands need not be pre-coated with resin and only one coating process is required, excellent effects such as easy production and high productivity can be obtained.
[0041]
According to claim 2, since the resin wire 4 has a diameter of 1.01 to 1.1 times that of the strand, and is arranged at a position spaced apart on the circumference by two or more, the adjacent strand and Can be formed, and a uniform gap can be formed between the core rope and the outer strand and between the side strands 2 and 2, and a spiral guide groove is formed between the thick resin wires 4 and 4. Therefore, the molten resin can be smoothly filled between the core rope and the outer strand and between the side strands 2 and 2, and each resin wire 4 has the reinforcing wire 4a. It is possible to obtain excellent effects such as being able to ensure.
[0042]
According to the third aspect, since the resin of the resin wire is made of the same material as the resin for covering the outer layer, the resin of the resin wire is melted by the heat of the resin for covering the outer layer, and the adhesive force is equal and uniform. An excellent effect that a joined state can be formed is obtained.
According to claim 4, since the core rope 1 has the synthetic resin coating layer 1b on the outer periphery, the contact between the core rope 1 and the outer strand 2 is reliably prevented while the core rope 1 and the outer strand 2 are connected. It is possible to obtain an excellent effect that the resin 30 for covering the outer layer that has penetrated can be reliably bonded.
According to claim 5, wear due to contact between the core rope 1 and the outer strand 2, wear due to contact between the adjacent outer strands 2, 2, and wear due to metal touch between the sheave and the outer strand 2 are prevented, and It is possible to realize good driving force transmission of the sheave and the entire rope, and it is not necessary to coat the side strand in advance with a resin, and only one coating process is required. Excellent effects such as being possible.
[Brief description of the drawings]
FIG. 1 is a partially cutaway perspective view of a first embodiment of a covered wire rope according to the present invention.
FIG. 2 is an enlarged cross-sectional view of FIG.
3A and 3B are enlarged partial cutaway perspective views of a resin wire according to the present invention.
4A is a perspective view of a side strand of the first embodiment, and FIG. 4B is a cross-sectional view taken along line IV-IV in FIG. 4A.
FIG. 5 is a cross-sectional view showing a state of the raw rope of the first embodiment.
6A is an explanatory view showing an outer layer covering step, and FIG. 6B is an explanatory view schematically showing a permeation state of a resin at the time of covering.
7A is a cross-sectional view showing the second aspect in the state of a bare rope, and FIG. 7B is a cross-sectional view of the rope of the second aspect.
FIG. 8 is an enlarged partial cutaway perspective view showing an embodiment to which the present invention is applied.
9 is an enlarged cross-sectional view of FIG.
FIG. 10 is a perspective view of a side strand.
FIG. 11 is a cross-sectional view of a side strand.
FIG. 12 is a cross-sectional view showing a state of an elementary rope.
FIG. 13A is a cross-sectional view of a side strand in another embodiment to which the present invention is applied, and FIG. 13B is a cross-sectional view showing a state of a bare rope.
FIG. 14 is an explanatory view showing a test jig for a rope of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Core rope 1a Core rope main body 1b Coating layer 2 Side strand 3 Outer layer coating 4 Resin wire 4a Reinforcement wire 4b Resin layer

Claims (5)

A rope having a plurality of side strands arranged and twisted on the outer periphery of the core rope and provided with an outer layer covering surrounding the side strands, wherein the upper layer of each side strand has a diameter larger than the strand diameter. A gap is formed between the side strand and the core rope and between the side strands by the presence of the resin wire having a relatively large diameter. A covered wire rope, wherein the resin is press-fitted and filled. Two or more resin wires are arranged at positions spaced apart on the circumference, and each resin wire is configured by providing a resin layer on the outer periphery of the reinforcing wire, and 1.01 to 1.1 with respect to the strands. The coated wire rope according to claim 1, which has a double diameter. The covered wire rope according to claim 1 or 2, wherein the resin layer of the resin wire is the same quality as the resin for covering the outer layer. The coated wire rope according to claim 1, wherein the core rope has a resin coating layer on an outer periphery of the rope body. A covered wire rope characterized by being a covered rope made in the next step.
Prepare a plurality of strands and one or more resin wires having a reinforcing wire in the center and a diameter larger than the strands, arrange the strands and the resin wires on the inner layer, and twist them together. A step of creating convex side strands, a step of arranging a plurality of side strands having one or more of these resin wires on the outer periphery of the core rope, twisting the whole, and manufacturing a bare rope, and an extruder A step of press-fitting and filling between the side strands and the side strands with the synthetic resin melted by passing the raw rope through the space between the side strands formed in the presence of the resin wire.

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