JP7483153B2 - Rope and its manufacturing method - Google Patents

Description

The present disclosure relates to a rope and a method for manufacturing the same.

In conventional wire ropes, multiple side strands are twisted around the outer periphery of a core rope. The core rope is made up of multiple core rope strands twisted together. Each core rope strand has multiple yarns. Each yarn is made up of a blend of monofilament and multifilament (see, for example, Patent Document 1).

JP 2013-170322 A

In conventional wire ropes such as those described above, there are many gaps between the monofilaments and between the multifilaments. As a result, when the core rope receives compressive force from multiple side strands, each core rope strand undergoes elastic or plastic deformation, causing the diameter of the core rope to shrink. As a result, the elastic elongation and elongation over time of the wire rope could not be sufficiently reduced.

The present disclosure has been made to solve the problems described above, and aims to provide a rope and a manufacturing method thereof that can reduce gaps within the core rope and suppress unnecessary elongation.

The rope of the present disclosure comprises a core rope and a number of steel strands twisted around the core rope, the core rope being constructed from a number of twisted core rope strands, each core rope strand having a number of first filaments made of synthetic fiber and a number of second filaments made of synthetic fiber, the diameter of each of the second filaments being smaller than the diameter of each of the first filaments, and the circumference of each of the first filaments being surrounded by the number of second filaments.
In addition, the method for manufacturing a rope according to the present disclosure includes a step of twisting a plurality of second filaments made of synthetic fiber, the second filaments having a smaller diameter than a first filament made of synthetic fiber, around the outer periphery of the first filament made of synthetic fiber to produce a small strand, a step of twisting the plurality of small strands together to produce a core rope strand, a step of twisting the plurality of core rope strands together to produce a core rope, and a step of twisting a plurality of steel strands around the outer periphery of the core rope.

The rope and manufacturing method disclosed herein can reduce gaps within the core rope and suppress unnecessary elongation.

FIG. 1 is a side view showing an elevator according to embodiment 1. FIG. 2 is a cross-sectional view of the main rope of FIG. FIG. 3 is an enlarged cross-sectional view of the core strand of FIG. 2. FIG. 4 is a cross-sectional view of the small strand of FIG. 3 immediately after production. FIG. 4 is an enlarged cross-sectional view of a portion of the core strand of FIG. 3 . FIG. 2 is an enlarged cross-sectional view showing a portion of a core rope strand according to a first comparative example. FIG. 11 is an enlarged cross-sectional view showing a portion of a core rope strand according to a second comparative example. FIG. 11 is an enlarged cross-sectional view showing a portion of a core rope strand according to a third comparative example. FIG. 4 is a cross-sectional view showing a first modified example of the main rope of the first embodiment. FIG. 11 is a cross-sectional view showing a second modified example of the main rope of the first embodiment. FIG. 11 is a cross-sectional view of a main rope according to embodiment 2. FIG. 11 is a cross-sectional view of a main rope according to embodiment 3.

Hereinafter, embodiments will be described with reference to the drawings.
Embodiment 1.
Fig. 1 is a side view showing an elevator according to embodiment 1. In Fig. 1, a machine room 2 is provided above a hoistway 1. A hoisting machine 3 and a deflector sheave 6 are installed in the machine room 2.

The hoist 3 has a hoist body 4 and a drive sheave 5. The hoist body 4 has a hoist motor (not shown) and a hoist brake (not shown). The hoist motor rotates the drive sheave 5. The hoist brake keeps the drive sheave 5 stationary. The hoist brake also brakes the rotation of the drive sheave 5.

A number of main ropes 7 are wound around the drive sheave 5 and the deflector sheave 6. Each of the main ropes 7 is an elevator rope.

The car 8 and counterweight 9 are suspended in the hoistway 1 by multiple main ropes 7. The car 8 and counterweight 9 move up and down in the hoistway 1 by rotating the drive sheave 5.

A pair of car guide rails 10 and a pair of counterweight guide rails 11 are installed in the elevator shaft 1. In FIG. 1, only one car guide rail 10 and one counterweight guide rail 11 are shown.

A pair of car guide rails 10 guide the car 8 as it rises and falls. A pair of counterweight guide rails 11 guide the counterweight 9 as it rises and falls.

The cage 8 has a cage frame 12 and a cage chamber 13. A plurality of main ropes 7 are connected to the cage frame 12. The cage chamber 13 is supported by the cage frame 12.

Figure 2 is a cross-sectional view of the main rope 7 in Figure 1, showing a cross section perpendicular to the length of the main rope 7. The main rope 7 in embodiment 1 is an 8 x S (19) type rope conforming to JIS G 3525.

The main rope 7 has a core rope 21 and multiple steel strands 22. In this example, eight steel strands 22 are twisted around the outer periphery of the core rope 21.

The core rope 21 is disposed at the center of a cross section perpendicular to the longitudinal direction of the main rope 7. The core rope 21 is formed by twisting together a number of core rope strands 23. In this example, three core rope strands 23 are used. That is, the core rope 21 in the first embodiment is a so-called triple-stranded rope. The core rope 21 may be impregnated with grease or oil.

Each steel strand 22 has a plurality of steel wires. The plurality of steel wires includes a central wire 24, a plurality of intermediate wires 25, and a plurality of outer layer wires 26.

The central wire 24 is disposed at the center of a cross section perpendicular to the longitudinal direction of the steel strand 22. A number of intermediate wires 25 are twisted around the outer periphery of the central wire 24. In this example, nine intermediate wires 25 are used.

The multiple outer layer wires 26 are twisted around the outer periphery of an intermediate layer consisting of multiple intermediate wires 25. In this example, nine outer layer wires 26 are used. That is, in each steel strand 22, the number of intermediate wires 25 and the number of outer layer wires 26 are the same.

The diameter of each outer layer wire 26 is smaller than the diameter of the central wire 24. The diameter of each intermediate wire 25 is smaller than the diameter of each outer layer wire 26.

When the load of the cage 8 and the counterweight 9 actually acts on the main rope 7, each steel strand 22 is pressed against the outer periphery of the core rope 21.

3 is an enlarged cross-sectional view of the core rope strand 23 of FIG. 2, showing a cross section perpendicular to the length of the core rope strand 23. Each core rope strand 23 has a plurality of first filaments 31 made of synthetic fiber and a plurality of second filaments 32 made of synthetic fiber.

The diameter of each second filament 32 is smaller than the diameter of each first filament 31. Conversely, the diameter of each first filament 31 is larger than the diameter of each second filament 32. When the diameter of the first filament 31 is d1 and the diameter of the second filament 32 is d2, it is preferable that d1/d2 is 2 or more. It is even more preferable that d1/d2 is 3 or more and 5 or less.

The outer periphery of each first filament 31 is surrounded by a plurality of second filaments 32. As a result, a plurality of second filaments 32 are interposed between adjacent first filaments 31.

The material of each first filament 31 is a first synthetic fiber. The material of each second filament 32 is a second synthetic fiber.

The second synthetic fiber is preferably selected taking into consideration its abrasion resistance against contact and abrasion with the steel strands 22. For this reason, the second synthetic fiber is preferably, for example, polyester fiber, particularly polyethylene terephthalate (PET) fiber.

The first synthetic fiber may be of the same material as the second synthetic fiber or of a different material than the second synthetic fiber.

For example, a polyethylene terephthalate filament having a diameter of 100 μm can be used as the first filament 31, and a polyethylene terephthalate filament having a diameter of 30 μm can be used as the second filament 32. In this case, d1/d2 is about 3.3.

If d1/d2 is smaller than 2, there is a possibility that the second filaments 32 will not be inserted sufficiently between the adjacent first filaments 31. However, d1/d2 is not necessarily limited to 2 or more.

Each core strand 23 is made up of multiple small strands 27 twisted together. In this example, seven small strands 27 are used.

Each small strand 27 has one first filament 31 and multiple second filaments 32. In each small strand 27, the multiple second filaments 32 are twisted around the outer periphery of the first filament 31.

Next, we will explain the manufacturing method of the main rope 7. The manufacturing method of the main rope 7 in embodiment 1 includes a small strand manufacturing process, a core rope strand manufacturing process, a core rope manufacturing process, and a process of twisting multiple steel strands 22 around the outer periphery of the core rope 21.

The small strand manufacturing process is a process in which multiple second filaments 32 are twisted around the outer periphery of a first filament 31 to produce a small strand 27.

Figure 4 is a cross-sectional view showing the state immediately after production of the small strand 27 of Figure 3. In the small strand 27 immediately after production, multiple second filaments 32 are evenly twisted around the outer periphery of the first filament 31.

The core rope strand manufacturing process is a process in which multiple small strands 27 are twisted together to produce the core rope strand 23.

The core rope manufacturing process is a process in which multiple core rope strands 23 are twisted together to produce the core rope 21.

After the core rope 21 is manufactured, the main rope 7 is manufactured by twisting multiple steel strands 22 around the outer periphery of the core rope 21.

Figure 5 is an enlarged cross-sectional view of a portion of the core rope strand 23 in Figure 3. Since multiple second filaments 32 are twisted around the outer periphery of each first filament 31, the multiple second filaments 32 are less likely to come apart even when multiple small strands 27 are twisted together. This more reliably achieves a state in which each first filament 31 is surrounded by multiple second filaments 32.

Figure 6 is a cross-sectional view showing an enlarged portion of a core rope strand according to a first comparative example. The core rope strand according to the first comparative example is composed only of a plurality of first filaments 31. Figure 7 is a cross-sectional view showing an enlarged portion of a core rope strand according to a second comparative example. The core rope strand according to the second comparative example is composed only of a plurality of second filaments 32.

In the core rope strand according to the first comparative example, the number of gaps is small, but the size of each gap is large. On the other hand, in the core rope strand according to the second comparative example, the size of each gap is small, but there are many gaps. Thus, when the diameters of all the filaments contained in each core rope strand are equal, the total amount of gaps does not change regardless of the diameter.

In contrast, in the core rope strand 23 of embodiment 1 shown in Figure 5, the diameter of each second filament 32 is smaller than the diameter of each first filament 31. In addition, multiple second filaments 32 are placed between adjacent first filaments 31. This makes it possible to significantly reduce gaps within the core rope strand 23.

Figure 8 is an enlarged cross-sectional view of a portion of the core rope strand according to the third comparative example. The core rope strand according to the third comparative example has a plurality of first yarns and a plurality of second yarns. Each first yarn is composed of a plurality of first filaments 31 bundled together. Each second yarn is composed of a plurality of second filaments 32 bundled together.

In the third comparative example, multiple second filaments 32 do not enter between adjacent first filaments 31. Therefore, the total amount of gaps is the same as in the first and second comparative examples.

Thus, in the main rope 7 of embodiment 1, the diameter of each second filament 32 is smaller than the diameter of each first filament 31. The outer periphery of each first filament 31 is surrounded by a plurality of second filaments 32.

In addition, in the small strand manufacturing process in the manufacturing method of the main rope 7 in embodiment 1, a small strand 27 is manufactured by twisting multiple second filaments 32 around the outer periphery of the first filament 31.

This reduces the gaps in the core rope 21, and prevents the diameter of the core rope 21 from decreasing when the core rope 21 receives compressive force from the multiple steel strands 22. This prevents unnecessary stretching of the main rope 7. It also extends the life of the main rope 7.

In addition, in elevators with long ascending and descending distances, vibrations of the car 8 when passengers get on and off the car 8 can be suppressed.

In addition, multiple second filaments 32 are twisted around the outer periphery of each first filament 31. This prevents multiple second filaments 32 from detaching from the outer periphery of each first filament 31 during the manufacturing process of the core rope strand 23. This makes it possible to more reliably reduce gaps in the core rope 21.

In addition, multiple second filaments 32 are interposed between adjacent first filaments 31. Therefore, adjacent first filaments 31 are not in direct contact with each other. This makes it possible to more reliably reduce gaps within the core rope 21.

Figure 9 is a cross-sectional view showing a first modified example of the main rope 7 of embodiment 1. In the first modified example, each steel strand 22 is compressed from the outside in the radial direction, so that the cross-sectional shape perpendicular to the longitudinal direction of each steel strand 22 is made circular. In other words, the cross-sectional shape of each steel strand 22 is deformed.

The main rope 7 according to this first modified example also achieves the same effects as those of embodiment 1.

The number of core rope strands 23 contained in the core rope 21 is not limited to three.

Furthermore, the number of steel strands 22 is not limited to eight.

Figure 10 is a cross-sectional view showing a second modified example of the main rope 7 of embodiment 1. In the second modified example, twelve steel strands 22 are used. Also, the cross-sectional shape of each steel strand 22 is deformed, as in the first modified example.

The main rope 7 according to this second modified example also achieves the same effect as in embodiment 1.

Embodiment 2.
Next, Fig. 11 is a cross-sectional view of the main rope 7 according to the second embodiment, showing a cross section perpendicular to the longitudinal direction of the main rope 7. The core rope 21 of the second embodiment has a central strand 33 and a plurality of outer circumferential strands 34 in addition to the plurality of core rope strands 23.

The central strand 33 is positioned at the center of the core rope 21 in a cross section perpendicular to the longitudinal direction of the core rope 21.

Each outer periphery strand 34 is disposed between adjacent core rope strands 23 on the outer periphery of the core rope 21. The number of outer periphery strands 34 is the same as the number of core rope strands 23. In embodiment 2, three outer periphery strands 34 are used for three core rope strands 23.

A twisted yarn made of synthetic fibers can be used as the central strand 33. For example, a strand having a cross-sectional configuration similar to that of the small strand 27 shown in FIG. 4 can be used as the central strand 33 after appropriately adjusting the diameter. A strand similar to the central strand 33 can be used as each of the outer periphery strands 34.

Other configurations in embodiment 2 are similar to those in embodiment 1.

In such a main rope 7, the gap in the center of the core rope 21 is filled by the central strand 33. This makes it possible to further reduce the gap in the core rope 21, and more reliably suppress unnecessary stretching of the main rope 7.

In addition, three gaps between adjacent core rope strands 23 on the outer periphery of the core rope 21 are filled by three outer periphery strands 34. This makes it possible to further reduce the gaps in the core rope 21, and more reliably suppress unnecessary elongation of the main rope 7.

In addition, either the central strand 33 or the multiple peripheral strands 34 may be omitted.

In addition, the main rope 7 of the first modified example shown in Figure 9 may be provided with at least one of a central strand 33 and multiple outer peripheral strands 34.

In addition, the main rope 7 of the second modified example shown in Figure 10 may be provided with at least one of a central strand 33 and multiple outer peripheral strands 34.

Embodiment 3.
12 is a cross-sectional view of the main rope 7 according to the third embodiment, showing a cross section perpendicular to the longitudinal direction of the main rope 7. The main rope 7 of the third embodiment has a core rope coating 35 in addition to the core rope 21 and the multiple steel strands 22. The core rope coating 35 covers the outer periphery of the core rope 21. That is, the core rope coating 35 is interposed between the core rope 21 and the multiple steel strands 22.

Resin or rubber can be used as the material for the core coating 35. Specifically, for example, polyethylene, polypropylene, polyvinyl chloride, polyamide, or polyurethane elastomer can be used as the material for the core coating 35.

The core rope coating 35 is applied to the outer periphery of the core rope 21 by a manufacturing process similar to that used to apply a coating to cables. That is, the core rope coating 35 is applied to the outer periphery of the core rope 21 by extrusion coating molding with the core rope 21 passing through the center.

Other configurations in embodiment 3 are the same as those in embodiment 1.

In such a main rope 7, three gaps between adjacent core rope strands 23 on the outer periphery of the core rope 21 are filled with the core rope coating 35. This makes it possible to further reduce the gaps in the core rope 21, and more reliably suppress unnecessary elongation of the main rope 7.

In addition, since the core rope 21 does not come into direct contact with the multiple steel strands 22, wear and damage to the core rope 21 can be suppressed.

In addition, the main rope 7 of embodiment 3 may be provided with at least one of the central strand 33 and multiple outer peripheral strands 34 shown in embodiment 2.

The main rope 7 of the first modified example shown in Fig. 9 may be provided with a core rope coating 35. The main rope 7 of the first modified example may be provided with a core rope coating 35 and at least one of a central strand 33 and a plurality of outer peripheral strands 34.

In addition, the main rope 7 of the second modified example shown in Fig. 10 may be provided with a core rope coating 35. In addition, the main rope 7 of the second modified example may be provided with a core rope coating 35 and at least one of the central strand 33 and the multiple outer peripheral strands 34.

In addition, in embodiments 1 to 3, the overall layout of the elevator is not limited to the layout in Figure 1. For example, the roping system may be a 2:1 roping system.

The elevator may also be a machine room-less elevator, a double deck elevator, a one-shaft multi-car elevator, etc. The one-shaft multi-car elevator is a system in which an upper car and a lower car located directly below the upper car each independently ascend and descend in a common elevator shaft.

The rope may also be another elevator rope other than the main rope 7, such as a compensator rope or governor rope.

Furthermore, the rope is not limited to an elevator rope, but may be a rope used for other purposes, such as a crane rope used in lifting equipment.

7 main rope (rope), 21 core rope, 22 steel strand, 23 core rope strand, 27 minor strand, 31 first filament, 32 second filament, 33 central strand, 34 outer strand, 35 core rope coating.

Claims (8)

a core rope; and a plurality of steel strands twisted around the outer periphery of the core rope,
The core rope is formed by twisting together a plurality of core rope strands,
Each of the core strands includes a plurality of first filaments made of synthetic fiber and a plurality of second filaments made of synthetic fiber;
a diameter of each of the second filaments is smaller than a diameter of each of the first filaments;
A rope in which the outer periphery of each of the first filaments is surrounded by the plurality of second filaments. The rope according to claim 1, wherein the plurality of second filaments are twisted around the outer periphery of each of the first filaments. A rope as described in claim 1 or claim 2, wherein each of the second filaments is made of polyester fibers. A rope as described in any one of claims 1 to 3, wherein the plurality of second filaments are interposed between adjacent first filaments. A rope as claimed in any one of claims 1 to 4, wherein the core rope has a central strand disposed at the centre of the core rope. The rope according to any one of claims 1 to 5, wherein the core rope has a plurality of outer circumferential strands arranged between adjacent core rope strands on the outer periphery of the core rope. 7. The rope of claim 1, further comprising a core rope coating covering an outer periphery of the core rope. A step of twisting a plurality of second filaments made of synthetic fiber, each having a smaller diameter than a first filament, around the outer circumference of the first filament made of synthetic fiber to produce a small strand;
twisting a plurality of the small strands together to produce a core strand;
A method for manufacturing a rope, comprising the steps of: twisting a plurality of said core rope strands together to manufacture a core rope; and twisting a plurality of steel strands around the outer circumference of said core rope.

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