JP5570741B2 - Elevator wire rope - Google Patents

Description

The present invention relates to an improvement in a wire rope for a moving cord used in an elevator.

The use of wire rope can be broadly divided into static and moving lines. The static cable is stationary with a load applied, but the moving wire rope passes through the sheave or is wound around the drum with the load applied to the rope.

A typical moving rope is an elevator rope. As shown in Fig. 8, the elevator box and the counterweight are wire ropes through two sheaves, one sheave linked to one drive motor and the other sheave that changes the direction of the wire rope. It is connected with. The elevator box moves up and down by utilizing the traction between the sheave rotating in conjunction with the drive motor and the wire rope. Since such a wire rope is subjected to bending stress in a state where a load is applied, the wire rope is damaged several times as compared with a static line in a state where a load is simply applied.

Conventionally, as shown in FIG. 1, such a wire rope for an elevator has a structure in which a plurality of side strands are arranged and twisted on the outer periphery of a fiber core such as hemp. However, in order to ensure proper traction between the wire rope and sheave unique to the elevator, measures such as adding a V groove or an undercut groove to the sheave have been made.
For this reason, when the wire rope is bent by the sheave, the contact between the surface of the wire rope and the sheave surface is likely to be distorted, and there is a problem that the wire rope shape collapse and the wire breakage are likely to occur.

Recently, a machine room-less elevator system as shown in FIG. 9 has been adopted. In this system, the elevator box is lifted by the wire rope, and therefore the number of sheaves through which the wire rope passes is significantly increased as compared with the conventional system of FIG.
Thus, the increase in the number of times the wire rope passes through the sheave inevitably increases the fatigue breakage of the strands due to the contact between the strands or the pressure contact between the sheave and the strands.

In order to prevent contact fatigue disconnection between adjacent strands due to such sheave bending, Japanese Patent Application Laid-Open No. 2008-248426 discloses a core rope in which a wire rope body formed by twisting steel strands or strands is coated with a resin. A technique is disclosed in which a resin cushioning material is disposed between the side strands around the core rope and twisted to improve wear disconnection due to contact between the strands.

However, recent machine room-less elevators tend to be more compact in structure and have a smaller sheave diameter, and accordingly, it is desired to make the wire rope thinner.
Therefore, when the conventional moving cord is applied to the elevator rope, the strands of the outer strand and the strand of the core rope are easily broken by repeated severe bending. However, in the prior art, the core rope twists the steel strand or the strand. Since the combined wire rope body is resin-coated, the steel wire may break, and even if the steel wire is broken, it is not known from the outside. For this reason, maintenance by the electromagnetic flaw detection method is indispensable, and there are problems such as requiring a lot of labor, time and cost for maintenance inspection.

JP 2008-248426 A

The present invention has been made to solve the above-mentioned problems, and the object of the present invention is to prevent maintenance of the inner strands of the core without causing internal disconnection of the core and to accurately move the side strands and the strands. To provide a wire rope for an elevator suitable for a machine room-less elevator system, which can reduce the breakage of a mountain, a valley, and a concentric contact surface, reduce the elongation, and improve the fatigue life. is there.

In order to achieve the above object, the present invention provides a rope having a core, a plurality of side strands arranged and twisted around the core, and a resinous spacer interposed between the side strands. It is made of a resinous continuous body, and the resin spacer has a contour corresponding to an outer layer strand of a side strand and penetrates between the outer layer strands.

According to the present invention, since the core is a resinous continuous body, there is no metal contact with the side strands, and the contact with the core contact surface can be greatly reduced. Further, since the core is made of a resinous continuous body, no wire breakage occurs inside the core, so that the electromagnetic flaw detection method is not required for maintenance, and the maintenance cost can be reduced.
In addition, since the resin spacers are interposed between the strands, the contact between the strands is prevented, so that the valley is prevented from being cut, and the surface pressure on the rope surface is reduced by increasing the number of contact points with the sheave. The life of the slice can be extended.
In addition, since the resin spacer has a contour corresponding to the outer layer strand of the side strand and penetrates between the outer layer strands, the movement of the strand is constrained and the cut of the contact surface can be reduced. In addition, excellent effects such as reduction in the elongation of the rope can be obtained.

It is sectional drawing of the conventional wire rope for elevators. It is sectional drawing which shows the 1st Example of the rope for elevators by this invention. (A) is sectional drawing which shows one Example of the resin spacer by this invention, (b) is a schematic diagram which shows the relationship between the clearance gap between strands, and the magnitude | size of a resin spacer. It is a closing process figure of this invention rope. It is explanatory drawing of the equipment used for the fatigue test. It is sectional drawing which shows 2nd Example of the rope for elevators by this invention. It is sectional drawing which shows another Example of this invention. It is explanatory drawing which shows the conventional elevator. It is explanatory drawing which shows the elevator of a machine room less.

The spacer and the resin core have a tensile strength of 20 MPa or more and an elastic modulus of 500 MPa or more, more preferably 30 MPa or more and an elastic modulus of 550 MPa or more.
According to this, since the tensile strength of the resin is 20 MPa or more, there is no breakage due to the tension at the time of manufacturing the wire rope. Further, since the elastic modulus is 500 MPa or more, when a tension is applied to the wire rope, a bridge effect is maintained in which the strand and the spacer come into contact with each other to maintain a circular shape, whereby a stable shape is obtained and the shape is not lost. Furthermore, since the elongation of the resin core is suppressed to a low level, the wire rope trimming operation is reduced.

The resin spacer penetrates between the strands at a filling rate of 50% or more. More preferably, the filling rate is 60% or more. Here, filling rate = area of resin penetrating between strands (A) / area of gap between strand circumscribed circle and outermost strand (B) × 100.
According to this, since the degree of resin penetration between the strands is high, the movement of the strands can be firmly fixed, and when the wire rope is bent by the sheave, the movement of the strands is reliably suppressed, and the concentric surface Cuts very little and life is improved. Further, the elongation can be reduced.

In addition, the resin spacer has a cross-sectional area larger than the gap between the strands in a single state, and is plastically deformed by being compressed from the outer periphery in a state of being arranged between the strands, and may be intruded between the strands. preferable.
According to this, it is possible to form a state in which the resin spacers are filled between the strands so as to mesh with the strands easily and reliably.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 2 shows an embodiment of an elevator wire rope according to the present invention, which is composed of a resin core 1, a plurality of side strands 2, and a resin spacer 3 interposed between the side strands 2. Yes.

The resin core 1 is made of a resin material having a cross section larger than the outer diameter of the side strand 2, and a resin continuous body obtained by extrusion molding or the like is desirable. In this example, the resin core 1 has a circular cross section.
The material of the resin core is desirably a material having high compression rigidity in order to stabilize the wire rope shape. For example, polyvinyl chloride, nylon, polyester, polyethylene, polypropylene, and copolymers of these resins can be used. If necessary, reinforcing fibers such as glass fibers may be added to the resin, and the tensile strength and elastic modulus are increased by adding the reinforcing fibers.

A plurality of side strands 2 (eight in the drawing) are used. The structure of each side strand 2 is arbitrary, but in this example, it has a structure of 8 × S (19). That is, nine relatively thin strands are arranged around the core strands, and nine outer layer side strands 201 are arranged around the strands and twisted.
Steel strands are used for the strands of the resin core 1 and the side strands 2. When the wire rope is required to have high fatigue and strength, a steel wire having a tensile strength of 160 kg / cm ² or more is used. Such a steel wire is obtained by drawing a raw material wire having a carbon content of 0.60 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. The diameter of the wire is selected so as to cope with fatigue and wear due to repeated bending by sheaves.

The side strands 2 are arranged at equal intervals on the outer periphery of the resin core 1, and resin spacers 3 are inserted into the gaps of the side strands 2 and twisted together with the side strands 2.
The resin spacer 3 is a strip made by extruding a thermoplastic resin. As the thermoplastic resin, the same system as the resin core can be used, and polyvinyl chloride, nylon, polyester, polyethylene, polypropylene and copolymers of these resins are generally used, but wear resistance, weather resistance, In addition to flexibility (stress crack resistance), thermoplastic resins that have moderate elasticity for adjusting the coefficient of friction with the sheave, have a relatively high coefficient of friction, and do not hydrolyze, such as acrylic and polyurethane (ether polyurethane) Etc.) are also suitable.

Note that, regardless of which material is used for the resin spacer 3 and the resin core 1, the tensile strength is 20 MPa or more and the elastic modulus is 500 MPa or more, more preferably 30 MPa or more and the elastic modulus is 550 MPa or more. It is preferable. The reason is that if the tensile strength is 20 MPa or less, there is a risk of breaking due to the tension at the time of manufacturing the wire rope. This is because the bridging effect may not be exhibited, a stable shape cannot be obtained, there is a risk of losing shape, and further, the elongation becomes large and the wire rope must be trimmed.

As shown in FIG. 3A, the resin spacer 3 has a head 3a enlarged in a fan shape and a fan-shaped base 3b smaller than the head, as shown in FIG. 3A, and these are continuous by a constricted edge 3b.
The resin spacer 3 has a cross-sectional area a ′ that is appropriately larger than the cross-sectional area a of the gap between the side strands 2 as shown in FIG. Specifically, this is realized by setting the thickness between the constricted edges 3b and 3b to a value increased by, for example, 10 to 30% with respect to the side strand arrangement gap between the layer centers.
The resin spacer 3 is inserted into each gap of each side strand 2 and twisted together with the side strand 2. The curvature top surface 300 of the head 3 a of the resin spacer 3 substantially coincides with the circumscribed circle of the rope, and the curvature lower surface 301 of the base 3 b is in close contact with the surface layer of the resin core 1.

The resin spacer 3 in a twisted state as described above is press-fitted and filled in the side edge portion, as shown in FIG. 2, beyond the circumscribed circle of the side strand 2 and into the gaps between the outer side strands 201 and 201. The press-fitting and filling portion 30 has a tapered mountain shape at the tip of the curved portion along the contour of the outer layer side strand 201.

Here, the size of the press-fitting and filling portion 30 is represented by a filling rate. When the area of the press-fit filling portion 30 penetrating between the outer layer side strands 201 and 201 is A, and the area of the gap S between the circumscribed circle of the side strand 2 and the outer layer side strands 201 and 201 is B, the filling rate Is defined as A / B × I00 (%).
In the present invention, the inter-element filling rate is 50% or more, more preferably 60% or more. The reason for this is that if the inter-element filling rate is less than 50%, the fixing of the element 201 becomes incomplete and the movement of the element 201 cannot be reliably suppressed when the wire rope is wound around the sheave. In addition, it is not possible to sufficiently reduce the breakage of the tangential surface, and because the restraining force of the wire is small and the elongation of the rope cannot be sufficiently reduced. The upper limit is about 99%.

The method of manufacturing the rope of the embodiment will be described. The resin core 1 is manufactured by continuously extruding a resin having a circular cross section with a resin extruder. Moreover, the required number of side strands 2 is manufactured. On the other hand, the required number of resin spacers 3 having a cross-sectional area larger than the gap between the side strands 2 and 2 are manufactured by an extruder.

Next, as shown in FIG. In FIG. 4, reference numeral 5 denotes a feeding portion, and a bobbin 50 that winds up the resin core 1 is disposed at the center, and a bobbin 51 that winds up the side strand 2 is disposed outside. A pipe shaft 6 extends in the downstream direction in the feeding portion 5, and a horn 7 is rotatably mounted on the pipe shaft 6, and a bobbin 71 having a resin spacer 3 wound around a core horn is disposed.
An end plate 8 is fixed near the tip of the pipe shaft 6. The end plate 8 has a hole through which the resin core 1, which is a core rope, is inserted at the center, and the side strands 2 are inserted into the outer periphery at equal intervals. And holes through which the resin spacers 3 are inserted are alternately provided. A voice 9 for applying a compressive force from the radial direction is located downstream of the end plate 8.

When the end plate 8 is rotated and guided to the voice 9 through the resin core 1, the side strand 2 and the resin spacer 3, the side strands 2, 2 are arranged on the outer periphery of the resin core l and between the side strands 2, 2. The resin spacer 3 is inserted and twisted to the rope while maintaining this state.
Moreover, since the voice 9 applies a compressive force from the radial direction, the resin spacer 3 intentionally having a cross-sectional area larger than the gap between the side strands 2 and 2 is not limited to the circumscribed circle of each side strand 2 and 2. As shown in FIG. 2, the excess cross-sectional integral is caused to flow between the outer layer side strands 201, 201 of the side strand 2 by plastic deformation, and is hardened in this state to form the press-fit portion 30.

Since the resin spacer 3 is interposed between the side strands 2 and completely separated, contact between the strands is prevented and valley breakage is prevented. Since the outer surface of the resin spacer 3 substantially coincides with the circumscribed circle of the rope, the number of contact points with the sheave increases and the surface pressure of the rope surface is reduced. As a result, the life of a mountain break due to wear can be extended.

Moreover, the resin spacer 3 is not merely interposed between the side strands 2 but also bites into the gaps between the strands 201 and 201 constituting the outermost layer of the side strands 2 to fill the gaps with resin. Since it is bonded to the strand 201 in this state, resistance to displacement is large. Therefore, since the movement of the strand 201 is suppressed, the cut of the contact surface is reduced.

FIG. 6 shows a second embodiment of the present invention, which has a structure of 8 × Fi (25). That is, six strands of the same diameter as the core strands are arranged and twisted around the core strands , and a total of six small-diameter strands are arranged and twisted between each strand. And twelve outer layer strands 201 are arranged around this and twisted.
Of course, the present invention is not limited to the 8-strand rope, but can be applied to a 6-strand rope as shown in FIG. The structure of the strand is the same as that of FIG. Since the other configuration is the same as that of the first embodiment, the description is incorporated.

Next, specific examples of the present invention will be shown.
Invention 1 is a wire rope having an 8 × S (19) structure shown in FIG. 2 and having a diameter of 0/0, a diameter of 20 mm, and a tensile strength of 1700 MPa.
As the resin core, a strip having a circular cross section with a diameter of 10.6 mm obtained by extruding a polypropylene resin having a tensile strength of 26.9 MPa and an elastic modulus of 631 MPa was used. The side strand used 8 diameter 5.0mm. The resin spacer used was a strip obtained by extruding the polypropylene resin having the above characteristics into a cross-sectional shape shown in FIG. This resin spacer was inserted between the side strands by the method shown in FIG. 4 and applied with a radial compressive force with a voice to be plastically deformed.

Invention 2 is a wire rope having an 8 × Fi (25) structure shown in FIG. 6 and having a diameter of 0/0, a diameter of 10.0 mm, and a tensile strength of 1700 MPa. The resin core used was a strip having a diameter of 5.3 mm obtained by extruding a polypropylene resin (tensile strength: 36.3 MPa, elastic modulus: 1190 MPa) added with glass fiber. Eight 2.5 mm diameter strands were used for the pull side strand. As the resin spacer, a strip formed by extruding polypropylene resin was used.
The resin spacer having a cross-sectional shape shown in FIG. This resin spacer was inserted between the side strands by the method shown in FIG. 4 and applied with a radial compressive force with a voice to be plastically deformed.

The above-mentioned inventions 1 and 2 were connected in an endless manner, and a u-bending fatigue test was performed in which a U-grooved drive sheave and a ram side sheave were wound and reciprocated as shown in FIG.
The test sheave diameter D and rope diameter d were D / d: 25 and SF: 10. The tension was 19.2 kN for Invention 1 and 4.8 kN for Invention 2.
For comparison, the conventional rope (comparative material 1) shown in FIG. 1 was also subjected to a fatigue test under the above conditions, and the number of disconnections between the outermost strands 5 pitches was examined by disassembling each rope. The results are shown in Table 1 together with the number of cycles.

From Table 1, it can be seen that the conventional product, which is a comparative material, has many mountain breaks due to contact pressure fatigue between sheaves and strands and valley breaks due to friction fatigue between adjacent strands.
On the other hand, in the products 1 and 2 of the present invention using the resin core and the resin spacer, even if the number of cycles is increased, the severance, the trough, and the tangential contact are greatly reduced. This is because the rigidity of the resin core is high and deformation due to bending at the sheave is prevented, and the movement of the strand is fixed by press-fitting the resin between the strands. This is because the movement of the line was effectively suppressed.

1 Resin core 2 Strand 3 Resin spacer 4 Strand outer layer strand

Claims (2)

A rope having a core, a plurality of side strands arranged and twisted around the core, and a resinous spacer interposed between the side strands, wherein the core is made of a resinous continuum, A resinous spacer has a contour corresponding to the outer strand of the side strand and penetrates between the outer strands;
The resinous spacer and the core are resins having a tensile strength of 20 MPa or more and an elastic modulus of 500 MPa or more,
The side strand includes a core strand, a plurality of inner layer strands arranged around the core strand, and a plurality of outer layer strands arranged around the plurality of inner layer strands, The core strand, the plurality of inner layer strands, and the plurality of outer layer strands are steel strands, and the plurality of inner layer strands are the core strand and the plurality of outer layer strands. rather fine than the line,
The core is formed by adding glass fiber to resin, and the outer diameter of the cross section of the core is larger than the outer diameter of the cross section of each of the plurality of side strands . The elevator wire rope according to claim 1 , wherein the resinous spacer penetrates between the outer layer strands at a filling rate of 50% or more.

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