WO2019049514A1

WO2019049514A1 - Elevator rope

Info

Publication number: WO2019049514A1
Application number: PCT/JP2018/026671
Authority: WO
Inventors: 前田　亮; 真人中山; 安部　貴
Original assignee: 株式会社日立製作所
Priority date: 2017-09-11
Filing date: 2018-07-17
Publication date: 2019-03-14
Also published as: JP6767327B2; CN111065594B; EP3683179A1; EP3683179A4; CN111065594A; JP2019048698A

Abstract

Provided is an elevator rope configured so that, even if the number of ropes is reduced by increasing the breaking strength of the ropes, the amount of variation in rope elongation caused by a variation in rope tension due to the vertical movement of an elevator can be reduced. This elevator rope is formed by twisting a plurality of strands together, the strands each being formed by twisting a plurality of steel wires together. The elevator rope is characterized in that, if the diameter of the elevator rope is designated as d (mm), the distance between strand windings, as a rope pitch P1, and the distance between steel wire windings, as a strand pitch P2, then the radio a of P1 to d, the ratio b of P2 to d, and the breaking strength T (N) of the elevator rope satisfy the following expression A. In the expression A above, E is the modulus of longitudinal elasticity (MPa) of a material used in the elevator rope, G is the modulus of transverse elasticity (MPa) of the material used in the elevator rope, and N is the number of strands.

Description

Elevator rope

The present invention relates to an elevator rope.

In general, elevator cars are suspended by wire ropes (hereinafter referred to as "ropes" or "elevator ropes"), which are wound around a drive sheave of a hoist, and rope grooves and ropes on the sheave surface. The car is raised and lowered by driving with friction.

For example, in a machine room-less elevator in which a hoisting machine is installed in a hoistway, downsizing of the hoisting machine is required in order to reduce the cross-sectional area of the hoistway. As a means for realizing this, there is thinning of the drive sheave. By thinning the drive sheave, the axial length dimension of the hoist can be shortened, and the hoist can be miniaturized. For this reason, a high strength rope is required as an elevator rope, which is high in breaking strength per one and can reduce the number of ropes required to suspend a car.

For example, Patent Document 1 discloses an IWRC having a core strand, a plurality of side strands disposed around the core strand, and a coating resin for covering the core strand and the plurality of side strands as a structure for strengthening the rope. (Independent Wire Rope Core) and multiple main strands placed around the IWRC,
In the elevator main rope comprising the plurality of side strands, the plurality of side strands are arranged at substantially equal intervals on the circumference of the virtual layer core circle where the centers of the plurality of side strands are located, with respect to the circumferential length of the virtual layer core circle Among the plurality of side strands, the main rope for elevators disclosed is characterized in that the ratio of the total of the gaps between two side strands adjacent in the circumferential direction of the virtual layer core circle is 8.5% or more. .

The rope disclosed in Patent Document 1 is wire-drawn into strands forming the rope to be thin, and has a breaking strength of 2300 MPa (the wire breaking strength of elevator ropes generally widely used is about 1620) It uses a wire which has been increased to the ~ 1910 MPa) grade. The strength of the rope is improved in proportion to the wire strength, and the number of ropes can be reduced.

International Publication No. 2016/199204

The number of ropes used for the elevator is determined from the ratio of the load received per rope and the breaking strength, and the number of ropes used per elevator is reduced by improving the breaking strength per rope. can do. One way to improve the breaking strength of the wire rope is to improve the breaking strength per wire constituting the wire rope, but the elastic modulus per wire is not proportional to the breaking strength. The rigidity of the entire rope is reduced by the reduced number of ropes. Therefore, for example, when the load applied to the rope suddenly changes due to getting on and off the elevator, the amount of expansion and contraction of the rope becomes large, and the riding comfort is reduced.

In order to prevent this, elevator ropes are required to have the property of being difficult to stretch even if tension is applied. However, in Patent Document 1, attention is focused mainly on the improvement of the rope life due to the contact suppression between the high-strengthened strands, and no consideration is given to the rope elongation.

In view of the above circumstances, an object of the present invention is an elevator rope capable of reducing the amount of change in rope elongation caused by fluctuation in rope tension due to getting on and off the elevator even if the breaking strength of the rope is improved to reduce the number of ropes. To provide.

In order to achieve the above object, the present invention is an elevator rope formed by twisting a plurality of strands of a plurality of steel wires, wherein the diameter of the elevator rope is d (mm) and the winding distance of the strands is a rope pitch The ratio a of P _{1 to} d, the ratio a of P ₁ to d, the ratio b of P _{2 to} d, and the breaking strength T (N) of the elevator rope satisfy the following equation A, where P ₁ and the winding distance of the steel wire are strand pitch P ₂ To provide an elevator rope characterized by

However, in the above equation, E: longitudinal modulus of elasticity (MPa) of material used for elevator rope, G: lateral modulus of elasticity (MPa) of material used for elevator rope, N: number of strands.

Further, in order to achieve the above object, according to the present invention, in an elevator rope formed by twisting a plurality of strands of a plurality of steel wires, the steel wires are formed by twisting a plurality of strands. When the diameter of the elevator rope is d (mm), the winding distance of the strands is rope pitch P ₁ , and the winding distance of the steel wire is strand pitch P ₂ , the ratio of P ₁ to d is to a, d Provided is an elevator rope characterized in that the ratio b of P ₂ and the breaking strength T (N) of the elevator rope satisfy the above-mentioned formula A.

More specific configurations of the present invention are described in the claims.

According to the present invention, it is possible to provide a wire rope for elevator capable of reducing the amount of change in rope elongation caused by fluctuation in rope tension due to getting on and off the elevator even if the breaking strength of the rope is improved to reduce the number of ropes. be able to.

Problems, configurations, and effects other than those described above will be clarified by the description of the embodiments below.

The side view which shows typically the 1st example of the elevator rope of this invention. The side view which shows typically the 2nd example of the elevator rope of this invention. It is a figure which shows the relationship between tension T and elongation (delta) L (tau), (delta) L (rho) in an elevator rope. The cross-sectional schematic diagram of the elevator rope in which the outermost layer of an elevator rope is comprised by ten strands. The cross-sectional schematic diagram of the elevator rope in which the outermost layer of an elevator rope is comprised by six strands. It is a cross-sectional schematic diagram of the elevator rope in which the outermost layer of a strand is comprised by six steel wires. It is a cross-sectional schematic diagram of the elevator rope in which the outermost layer of a strand is comprised by 12 steel wires. It is a cross-sectional schematic diagram of the elevator rope (third twist) which has a steel wire to which the wire was twisted. Rope distortion amount: It is a graph which shows the relationship of the strand pitch multiple at the time of 0.55%, and a rope pitch multiple. It is a side view which shows typically the elevator rope produced for the test. It is a graph showing the relationship between the elongation amount [delta] L ₁ and rope pitch P ₁ and strand pitch P ₂ of the rope.

Hereinafter, an embodiment of a wire rope for elevators according to the present invention will be described with reference to FIGS. 1 and 2.

FIG. 1 is a side view schematically showing a first example of the elevator rope of the present invention. As shown in FIG. 1, the elevator rope 1 is formed by twisting a plurality of strands 2 in which a plurality of steel wires 3 are twisted. Only one strand 2 and one steel wire 3 are shown in FIG. 1 in consideration of the viewability of the drawing.

Although not shown in FIG. 1, a core (fiber core, steel wire core, etc.) is disposed at the center of the elevator rope 1, and the strand 2 is twisted on the core. The plurality of strands 2 are arranged on the same circumference at substantially equal intervals. The same applies to the steel wire 3. The strands 2 and the steel wire 3 may be arranged in two layers in which two layers are arranged on the circumference in addition to one layer circumferentially arranged in the radial direction, and three in which the three layers are arranged on the circumference There are also some which are constituted by a plurality of layers, such as layer arrangement.

In the present invention, spacing the strands 2 of one constituting the elevator rope is around the (winding gap) and rope pitch P _1, spacing steel wire 3 constituting the strands 2 makes one rotation (winding gap) the strand pitch P ₂ I assume. In other words, the rope pitch P ₁ is the length of up to strand 2 is round around a core, length to strand pitch P ₂ is steel wire 3 is slightly around the central axis of the strand It is.

FIG. 2 is a side view schematically showing a second example of the elevator rope of the present invention. In FIG. 2, the steel wire 3 has shown what was formed by stranding two or more strands 3a. The present invention can also be applied to an elevator rope of such a configuration. Spacing wires 3a constituting the steel wire 3 makes one rotation (the winding interval) and steel wire pitch P _3.

Next, the generation mechanism of the elongation of the elevator rope will be described with reference to FIG. FIG. 3 is a view showing the relationship between tension T and elongation δLτ and δLρ in the elevator rope. The case where tension T acts on the twisted strand in the axial direction of the twist center axis 30 is considered. At this time, the elongation of the strand 2 is caused by the tensile force acting in the axial direction of the elongation ΔLτ generated by the shear force acting on the cross section of the strand 2 and the twist elongation and the axis 31 extending in the perpendicular direction of the cross section of the strand 2 It is given by the sum of an elongation δLρ due to the occurrence of a slight strain in the strand 2 itself (the central axis 30 of the twist and the axis 31 in the direction perpendicular to the strand cross section have an angle of θ °).

Thus, the elevator rope length L _1, elongation [delta] L ₁ when the tension T ₁ is acted in the direction of the central axis of twisting of the strands, can be expressed as the following equation (1). Similarly, the elongation δL ₂ when tension T ₂ acts in the central axis direction of the twist of the steel wire 3 of length L ₂ can be expressed as the following equation (2), and the strand 3a of length L ₃ The elongation δL ₃ when tension T ₃ acts in the central axis direction of the twist of can be expressed as the following equation (3).

δL ₁ = δL ₁ τ + δL ₁式 equation (1)
δL ₂ = δL ₂ τ + δL ₂式 equation (2)
δL ₃ = δL ₃ τ + δL ₃式 equation (3)
However, L ₁ is the length in the central axis direction of strand twist (mm), L ₂ is the length in the central axis direction of steel wire twist (mm), and L ₃ is the length in the central axis direction of strand of strand (Mm).

In a strand formed by twisting a plurality of steel wires, the tensile force acting in the perpendicular direction of the strand cross section is the same because the vertical direction of the strand cross section and the central axis direction of the twist of the steel wire are the same direction, It becomes a force acting in the central axis direction of the twist of the steel wire. Therefore, it is considered that the elongation δL ₁ ρ by the tensile force of the strand is equal to the elongation δL ₂ of the entire steel wire. This relationship is the same as in a steel wire formed by twisting a plurality of strands, and the above-mentioned relationship can be summarized as a secondary twist rope (a rope on which the strands of FIG. 2 and the steel wire are twisted) The elongation of can be expressed as in equation (4), and the elongation of the tertiary twist rope (the strand in FIG. 3 with which the strands, steel wires and strands are twisted) can be expressed as in equation (5).

δL ₁ = δL ₁ τ + δL ₂ τ + δL ₂ ρ Equation (4)
δL ₁ = δL ₁ τ + δL ₂ τ + δL ₃ τ + δL ₃ ρ equation (5)
In the equations (4) and (5), the elongation δL ₁ τ when tension T ₁ acts in the central axis direction of twist of the strand of length L ₁ is expressed by the following equation, where K ₁ τ is the spring constant of the strand obtained in (6), _{K 1} τ can be expressed as the following equation (7). The same equation can be found when, for example, the spring constant of a coil spring is determined.

δL ₁ τ = T ₁ / K ₁ τ Equation (6)
K ₁ τ = 0.03 × G × S ₁ / n ₁ / d ₀ equation (7)
Here, G is the transverse elastic modulus (MPa) of the strand, S ₁ is the cross-sectional area per _one strand (mm ² ), n ₁ is the number of strand twists (pieces) per length L ₁ and d ₀ is the rope diameter (Mm)

Similarly, the elongation δL ₂ τ when tension T ₂ acts in the central axis direction of the twist of the steel wire of length L ₂ is obtained by the following equation (8), where K ₂ τ is the spring constant of the steel wire is, the K ₂ tau can be expressed by the following (9) formula. Furthermore, the elongation δL ₃ τ when tension T ₃ acts in the central axis direction of the strand of length L ₃ in strand is determined by the following equation (10), where K ₃ τ is the spring constant of the strand. , K ₃ τ can be expressed as (11) below. However, in the case of a strand, there is only a geometrical constraint in one axial direction (vertical direction), but in the case of a steel wire, since it is further twisted, geometrical shape in three axial directions (upper, lower, front, back, left and right). Restraint. Therefore, as the order of twist increases, the spring constant of the steel wire also increases, so it was multiplied by the constraint coefficient.

δL ₂ τ = T ₂ / K ₂ τ Equation (8)
K ₂ τ = 0.03 × α × G × S ₂ / n ₂ / d ₀ equation (9)
Here, _{S 2} is the cross-sectional area per one steel wire ^(mm _{2), n} 2 is the number of twisted steel wires per length _{L 2} (pieces), alpha is the constraint factor (α = 10).

δL ₃ τ = T ₃ / K ₃ τ Equation (10)
K ₃ τ = 0.03 × α ² × G × S ₃ / n ₃ / d ₀ equation (11)
Here, _{S 3} is a cross-sectional area per one wire ^(mm 2), _{n 3} is the number of twists of the strand per length _{L 3} (pieces), alpha is the constraint factor (α = 10).

The number of twists strand steel wire-strand is a value determined by the rope pitch P _1-strand pitch P ₂ · steel wire pitch P _3, the ratio of rope pitch against the rope diameter d ₀ a (P ₁ / Assuming that d ₀ ), the strand pitch ratio is b (P ₂ / d ₀ ), and the steel wire pitch ratio is c (P ₃ / d ₀ ), equations (12) to (14) can be expressed.

n ₁ = L ₁ / (d ₀ × a) Equation (12)
n ₂ = L ₂ / (d ₀ × b) Equation (13)
n ₃ = L ₃ / (d ₀ × c) Equation (14)
Next, the relationship between the rope cross-section structure, the strand diameter, the steel wire diameter, the strand diameter, the strand diameter of the strand, the strand diameter of the steel wire, and the strand diameter of the strand will be described using FIGS. . FIG. 4 is a schematic cross-sectional view of an elevator rope in which the outermost layer of the elevator rope is composed of ten strands, and FIG. 5 is a diagram in which the outermost layer of the elevator rope is composed of six strands. In FIGS. 4 and 5, the number of steel wires in the outermost layer of the strand is nine. Moreover, FIG. 6 is a cross-sectional schematic view of an elevator rope in which the outermost layer of the strands is composed of six steel wires, and FIG. 7 is the outermost layer of the strands composed of 12 steel wires. In FIGS. 6 and 7, the number of strands of the outermost layer of the elevator rope is eight. Further, FIG. 8 is a schematic cross-sectional view of an elevator rope (third twist) having a steel wire in which strands are twisted.

As shown in FIGS. 4 to 8, the strands, steel wires, and strands are arranged substantially equally on the circumference. Therefore, strand diameter: d ₁ , steel wire diameter: d ₂ , wire diameter: d ₃ and strand twist diameter: D ₁ , steel wire twist diameter: D ₂ and strand wire diameter D ₃ are geometrically The following equations (15) to (17) are established.

d ₁ = d ₀ × sin (π / N ₁ ) / (1 + sin (π / N ₁ ))
D ₁ = d ₀ -d ₁ equation (15)
Here, N ₁ is the number of outermost layer strands (piece).

d ₂ = d ₁ × sin (π / N ₂ ) / (1 + sin (π / N ₂ ))
D ₂ = d ₁ -d ₂ equation (16)
Here, N ₂ is the outermost layer steel wire number (present).

d ₃ = d ₂ × sin (π / N ₃ ) / (1 + sin (π / N ₃ ))
D ₃ = d ₂ -d ₃ equation (17)
Where N ₃ is the outermost layer strands number (present).

Then, when the tension T ₀ is applied to the rope, it determines the tension applied to one per outermost strand outermost steel wire, the outermost layer strands. These are determined by the ratio of the cross-sectional area of strands, steel wires and strands, and can be determined geometrically. Assuming that the tension applied to the outermost layer strand is T ₁ , the tension applied to the outermost layer steel wire is T ₂ , and the tension applied to the outermost layer wire is T ₃ , the following expressions (18) to (20) can be expressed is there.

T ₁ = T ₀ / N ₁ equation (18)
T ₂ = T ₁ × (S ₂ / S ₁ ) Formula (19)
T ₃ = T ₂ × (S ₃ / S ₂ ) Formula (20)
Next, the relationship of the twist angle of a strand, a steel wire, and a strand is demonstrated. Twist angle, rope pitch P ₁ · strand pitch P ₂ · steel wire pitch P ₃ and the twist diameter of the strand, the steel wire twisted diameter, Sadamari by twisting diameter of the wire, the following equation (21) - (23) It can be expressed as

θ ₁ = tan ⁻¹ (D ₁ × π / (d ₀ × a)) Equation (21)
θ ₂ = tan ⁻¹ (D ₂ × π / (d ₀ × b)) Equation (22)
θ ₃ = tan ⁻¹ (D ₃ × π / (d ₀ × c)) Equation (23)
Here, θ ₁ is a strand twist angle (rad), θ ₂ is a steel wire twist angle (rad),
theta ₃ shows the twist angle (rad) of the wire.

Moreover, the length of a strand, a steel wire, and a strand can be calculated | required using each twist angle. In a strand constructed by twisting a plurality of steel wires, the helical length of the stranded strands (length when the strands are extended) and the length in the central axis direction of the twist of the steel wires are equal . Similarly, in a steel wire formed by twisting a plurality of strands, the helical length of the stranded steel (length when the steel is stretched) and the central axis direction of the strand of the strands The lengths of are equal. Therefore, the relationship between the length in the central axis direction of the strand: L ₁ , the length in the central axis direction of the steel wire: L ₂ , and the length in the central axis direction of the strand: L ₃ is expressed by the following equation (24 And (25) can be expressed.

L ₂ = L ₁ / cos θ ₁ equation (24)
L ₃ = L ₂ / cos θ ₂ equation (25)
Next, the elongation δL ₂とき when tension T ₂ acts in the central axis direction of the twist of the steel wire of length L ₂ is between the central axis of the steel wire twist and the vertical axis of the steel wire cross section considering that is angled by twisting the steel wire, the K ₂ [rho given by: and the spring constant of the steel wire (26), expressed as K ₂ [rho following formula (27) it can.

_{_{_{δL 2ρ = T 2 × cosθ 2}}} / K 2ρ formula (26)
K ₂ ₌₌ E × S ₂ / (L ₂ / cosθ ₂ ) Formula (27)
Here, E is taken as the modulus of longitudinal elasticity (MPa) of the steel wire.

Similarly, the elongation _δL ₃ _{とき} when tension T ₃ acts in the central axis direction of strand twist of length L ₃ is between the central axis of strand twist and the vertical axis of the strand cross section _Assuming that K 3 _{による} is a spring constant of a steel wire in consideration of the angle attached by stranding of the wire, it can be obtained by the following equation (28), and K 3 _は can be expressed as equation (29).

_δL ₃ = = T ₃ × cos θ ₃ / K ₃ _式 equation (28)
K ₃ ₌₌ E × S ₃ / (L ₃ / _cosθ ₃ ) Formula (29)
Therefore, when the calculation formulas of the formulas (1) to (29) described above are put together, in the secondary twist rope, the number of strands: N ₁ , the number of steel wires: N ₂ , and the ratio of rope pitch to rope diameter: a, the ratio of strand pitch: b in twisted rope diameter: _{d 0,} length: _{L 1} rope tension: _{T 0} is the elongation amount when the effect: [delta] L _1, the following expressions in equation (30) it can.

Similarly, in the third twist rope, the strand number: N ₁ , the steel wire number: N ₂ , the wire number: N ₃ , and the ratio of rope pitch to rope diameter: a, strand pitch ratio: b, steel wire ratio of pitch: twisted at c rope diameter: _{d 0,} length: _{L 1} rope tension: elongation amount _{when T 0} is applied: [delta] L ₁ can be expressed by equation (31) below.

From the above equations (30) and (31), the amount of strain of the rope decreases as the number of strands: N ₁ increases in both the secondary and third-order twisted ropes, while the number of steel wires: N ₂ , the number of strands : N ₃ has no effect on the amount of strain of the rope. This is because the cross-sectional area of the rope increases as the number of strands increases, but the cross-sectional area of the rope hardly changes even if the number of steel wires or the number of strands increases or decreases. Therefore, in the study of rope elongation, it is not necessary to consider the number of steel wires: N ₂ and the number of wires: N ₃ .

As for the twist pitch, as shown in the equations (9) and (10) described above, the influence on the rope elongation decreases as the twist order increases, and the ratio of the rope pitch in the ratio of steel wire pitch: c It affects only 1/100 of: a, which is a very small value. Therefore, in consideration of rope elongation, it is considered that the twist pitch of the steel wire can be ignored. Therefore, in the present invention, since the rope pitch ratio a and the strand pitch ratio b may be defined, it is not necessary to consider the steel wire pitch ratio c constituting the inside of the strand.

By the above guidelines, when the rope breaking strength is improved, the load per rope increases, and the problem that the rope elongation (the amount of strain of the rope) increases is the equation (30) and the equation (31). ) than, it is found that can reduce the amount of strain the rope by increasing the rope pitch P ₁ and strand pitch P _2.

That is, as described above, the elongation caused by applying a load to the twisted steel wire means the elongation caused by the shear force acting on the rope cross section and the twist elongation and the tensile force acting in the direction perpendicular to the cross section It is the sum of the elongation due to the occurrence of a slight strain in itself. Therefore, if the pitch of each twist is lengthened, the elongation which arises by twist extension can be reduced and the extension of the whole rope can be controlled.

In the present invention, the configuration of the elevator rope (the number of strands, steel wires and strands) is arbitrary. Further, in the present invention, it is not necessary to consider the twist pitch of the steel wire 3 (in the present invention) other than the two outer sides (in the present invention, the rope 1 and the strand 2) constituting the elevator rope. For example, in addition to the configuration shown in FIG. 1 and FIG. 2, there is also a configuration of an elevator rope formed by twisting a plurality of schenkels by twisting a plurality of strands. do it.

On the other hand, as the rope pitch, the strand pitch and the steel wire pitch are lengthened, the number of times of twisting decreases and the twisting is likely to be unraveled, which may make it impossible to form a rope. In that case, the rope shape can be maintained by covering the rope with plastic or resin.

Next, the design of the elevator rope using the above equations (30) and (31) will be described. In the elevator, when the strain amount of the rope becomes large, not only the riding comfort but also the danger of stumbling or the like at the time of getting into the car tends to occur, so the outermost floor correction device is provided. However, if the floor alignment movement becomes too large, there is a risk that the toe etc. may be pinched, so the car floor fluctuation is within 75 mm (see Ministry of Construction Notification No. 1429 "Declaration of Structure of Elevator Controller"). It must be made to be a defined value).

Here, the travel of a typical high-rise apartment or office building: 80 m as a standard, and the load fluctuation in the car, the rope safety factor: 12, the rope safety factor: 10 (safety specified by the Building Standard Law It is assumed that the allowable rope distortion amount at the time of setting the minimum value) is 0.092%. At this time, the allowable strain amount when the safety factor is 10 from the no-load state is 0.55%. Therefore, in order to make the safety factor 10 or more, it is necessary to make the rope distortion amount 0.55% or less.

FIG. 9 is a graph showing the relationship between the strand pitch multiple and the rope pitch multiple when the rope distortion amount is 0.55%. The case where the breaking strength of the material of the steel wire is examined under four conditions of 1770 MPa, 1910 MPa or less, 2300 MPa or less and 3200 MPa is shown. In the graph of FIG. 9, the rope distortion amount is less than 0.55% in the area outside the lines (area where the strand pitch multiple and the rope pitch multiple are large).

Here, the elevator rope with a breaking strength of 1770 MPa is an elevator rope of “Class B” (JIS G 3525) defined by JIS Standard (Japanese Industrial Standards), and the elevator rope with a breaking strength of 1910 MPa is defined by “T It is an elevator rope of "species" (JIS G 3525). These two elevator ropes are generally widely spread. The breaking strengths of 2300 MPa and 3200 MPa are higher than those of the above-mentioned generally popular elevator ropes.

As shown in FIG. 9, it can be seen that the strand pitch and the rope pitch need to be increased in order to set the rope strain amount: 0.55% or less as the breaking strength of the elevator rope increases. In the present invention, it can be seen that, in a high strength elevator rope having a breaking strength of 3200 MPa, if P ₂ = 2.5 and P ₁ = 17.2, the rope strain can be 0.55% or less. In other words, even if the elevator rope is strengthened (breaking strength 3200 MPa) and the number is reduced, the rope strain will be 0.55% or less if P ₂ = 2.5 and P ₁ = 17.2 are satisfied. The amount of change in rope elongation caused by the fluctuation in rope tension can be sufficiently reduced.

Even when using strands and steel wires having breaking strengths other than the above, by substituting the value of 1/10 (safety factor: 10) of rope breaking strength into equation (32), rope strain amount: 0.55 The rope pitch P ₁ and the strand pitch P ₂ required to achieve% or less can be calculated.

Next, a test was conducted to confirm the validity of the calculation based on the above guidelines. FIG. 10 is a side view schematically showing a rope produced for the test. The elevator rope 101 for the test includes the diameter d ₀ of the elevator rope 1: 8.0 (mm), the number N _{1 of} strands 102: 4 (pieces), and the number of steel wires 103 of the outermost layer of the strands 102: 7 (pieces ), Number of outermost strands 103a of the steel wire 103: 7 (pieces), Rope base length (length in the central axis direction of strand twist) L ₁ : 21000 (mm), applied load (tension T ₀ ) The longitudinal elastic modulus E of the steel wire is 205,000 MPa, and the lateral elastic modulus G of the steel wire is 170800 MPa, and the surface is coated with the resin 104 so that the rope is not deformed.

Figure 11 is a graph showing the relationship between the elongation amount [delta] L ₁ and rope pitch P ₁ and strand pitch P ₂ of the rope. In FIG. 11, calculated values and experimental values are compared. In the elevator rope 101 of FIG. 10, the rope pitch: P ₁ (mm), the strand pitch: P ₂ (mm), and the steel wire pitch: P ₃ (mm), experiments and calculations were performed under the following conditions 1 to 3 .

Condition 1: P ₁ = 90 (mm), P ₂ = 16 (mm), P ₃ = 12 (mm)
Condition 2: P ₁ = 180 (mm), P ₂ = 32 (mm), P ₃ = 18 (mm)
Condition 3: P ₁ = 360 (mm), P ₂ = 60 (mm), P ₃ = 24 (mm)
FIG. 11 shows the calculated elongation amount and the experimental value (measured value) of each rope at L ₁ = 21000 (mm) and T ₀ = 6000 (N). The error between the calculated value and the experimental value for all three levels is less than ± 10%, which confirms that sufficient calculation accuracy is secured.

From the above, the “ratio a of the rope pitch P _{1 to} the rope diameter d” and the strand pitch P _{2 to the} rope diameter d can be suppressed to a predetermined rope distortion amount (0.55%) or less required for the elevator wire rope. It can be seen that the ratio b ′ ′ may be in a range that satisfies the following equation (32).

When the above equation (32) is arranged with the left side as b, the above equation A is obtained.

As described above, according to the present invention, even if the breaking strength of the rope is improved to reduce the number of ropes, it is possible to reduce the amount of change in the rope elongation caused by the fluctuation of the rope tension due to getting on and off the elevator. It has been shown that a wire rope can be provided.

The present invention is not limited to the embodiments described above, but includes various modifications. For example, the embodiments described above are described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the configurations described. Further, part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. In addition, with respect to a part of the configuration of each embodiment, it is possible to add, delete, and replace other configurations.

1, 101: elevator rope, 2, 102: strand, 3, 103: steel wire, 3a, 103a: strand, 104: resin, 30: central axis of twist, 31: axis in a direction perpendicular to the strand cross section.

Claims

In an elevator rope formed by twisting a plurality of strands of a plurality of steel wires,
Assuming that the diameter of the elevator rope is d (mm), the winding distance of the strands is rope pitch P 1 , and the winding distance of the steel wire is strand pitch P 2 , the ratio a to d of the P 1 to the d An elevator rope characterized in that the ratio b of P 2 and the breaking strength T (N) of the elevator rope satisfy the following formula A.

However, in the above-mentioned formula A, E: longitudinal modulus of elasticity (MPa) of the material used for the elevator rope, G: lateral modulus of elasticity (MPa) of the material used for the elevator rope, N: for the strand It is assumed to be the number.
The elevator rope according to claim 1, wherein the P 1 is 17.2 and the P 2 is 2.5.
The elevator rope according to claim 1 or 2, wherein the breaking strength of the steel wire is 3200 MPa.
The elevator rope according to claim 1, wherein the breaking strength of the steel wire is 2300 MPa.
The elevator rope according to claim 1, wherein a breaking strength of the steel wire is 1910 MPa.
The elevator rope according to claim 1, wherein a breaking strength of the steel wire is 1770 MPa.
In an elevator rope formed by twisting a plurality of strands of a plurality of steel wires,
The steel wire is formed by twisting a plurality of strands,
Assuming that the diameter of the elevator rope is d (mm), the winding distance of the strands is rope pitch P 1 , and the winding distance of the steel wire is strand pitch P 2 , the ratio a to d of the P 1 to the d the elevator ropes, characterized in that P 2 ratio b and breaking strength of the elevator rope T (N) satisfies the following equation.

However, in the above-mentioned formula A, E: longitudinal modulus of elasticity (MPa) of the material used for the elevator rope, G: lateral modulus of elasticity (MPa) of the material used for the elevator rope, N: for the strand It is assumed to be the number.
Wherein P 1 is 17.2, elevator rope according to claim 7, wherein said P 2 is 2.5.
The elevator rope according to claim 7 or 8, wherein the breaking strength of the steel wire is 3200 MPa.
The elevator rope according to claim 7, wherein the breaking strength of the steel wire is 2300 MPa.
The elevator rope according to claim 7, wherein the breaking strength of the steel wire is 1910 MPa.
The elevator rope according to claim 7, wherein the breaking strength of the steel wire is 1770 MPa.