RU2330137C2 - Method of double-layer cable lay - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: method of double-layer cable lay includes operations of laying the first layer of strands, and then the second layer of strands around the core. During performance of operation of strands first layer laying tension of every strand of the first layer is measured. Radial and angular shift of tension resultant is measured in respect to longitudinal axis of cable. Bending moment value is determined. Prior to laying of the second layer of cable strands every strand is tightened so that bending moment is equal in value to bending moment of the first layer of strands and opposite in direction.

EFFECT: increase of service life and quality of double-layer cable.

2 cl, 3 dwg

Description

The invention relates to the production of steel ropes, namely the production of multilayer ropes, used in hoisting-and-transport, shaft installations and other devices.

Currently, the lay-up process of multi-layer ropes is carried out on multi-rotor rope machines [Bukstein M.A. Steel wire rope production. M .: "Metallurgy", 1963, p.145-146].

The disadvantage of this technical solution is that when twisting the rope, the tension of each strand is created by a braking device made in the form of a tape brake. Since the setting of the braking torque on the brake of the coils with strands is carried out manually, the magnitude of the strand tension is not the same.

The closest technical solution is the method of twisting a two-layer rope (adopted as a prototype), including the operation of pulling strands and twisting the first layer, and then stretching the strands and twisting the second layer [Korolev V.D. Rope production. M., "Metallurgy", 1980, S. 136-140].

The disadvantage of this method of lay is the following.

When performing the operation of pulling strands and then twisting their layer, the rope turns out to be twisted from strands of unequal length in one layer due to imperfection of the brake of the coils, it is necessary to adjust the braking torque on the coils with strands.

When twisting the rope due to the take-off of mechanical properties and the unevenness of the technological strains of the strands, they are laid in a rope with different lengths of strands in one layer. In this case, a strand having a high tension is laid in a rope with a minimum length, and vice versa, a strand having a minimum tension is laid in a rope with a maximum length. A strand having a greater length in comparison with others, under the action of a tensile load, gets smaller deformations, and vice versa. When tensioning such a rope, the resultant is displaced relative to the longitudinal axis of the rope, forming a bending moment. Therefore, such a rope under the action of a bending moment takes the form of a helical spiral, i.e. the rope has a defect - waviness (difference in geometric parameters and mechanical properties of screw elements). Moreover, the strands of such a rope are constantly located either on the concave or on its convex sides.

These shortcomings lead to a decrease in the service life and quality of the rope due to the difference in the lengths of the strands and their wear.

The technical result of the claimed method is to increase the service life and quality of a two-layer rope.

The specified technical result is achieved in that in the known method of twisting a two-layer rope, including the operations of twisting the first layer of strands, and then the second layer of strands around the core, according to the invention, when performing the operation of twisting the first layer of strands, the strains of each strand of the first layer are measured and the radial and angular displacement is determined the resultant tension relative to the longitudinal axis of the rope and the magnitude of the bending moment, and before stranding the second layer of rope strands, each strand is tensioned k so that the bending moment is equal in magnitude to the bending moment of the first layer of strands and opposite in direction. The radial and angular displacement of the resultant tension and the magnitude of the bending moment are determined by the formulas:

;

;

;

;

_;

_;

_;

_;

_;

_;

,

,

,

- смещение равнодействующей относительно оси X и Y;Where

,

- the offset resulting from the axis X and Y;

,

- координаты прядей каната относительно оси X и Y;

,

- the coordinates of the strands of the rope relative to the axis X and Y;

P _{i CR} - tension i strands of the first layer of the rope;

φ is the polar angle (angular displacement);

e _i is the offset of the resultant strands of the i-th layer;

∑P _i ol - the total value of the resultant tension of the strands of the i-th layer.

The proposed method of twisting a two-layer rope will improve the quality of multilayer ropes, as well as prevent the occurrence of a defect - waviness.

To explain the invention, a specific embodiment of the invention is given below with reference to the accompanying drawings:

figure 1 is a kinematic diagram of a two-rotor rope machine;

figure 2 - tape brake;

figure 3 - offset resultant of the first layer relative to the longitudinal axis of the rope.

The proposed method is implemented on a rope machine (Fig. 1), containing during the process of twisting: two rotors 1 and 2, each of which has a carriage 3 with charging coils 4 for strands 5. The necessary tension coming from the charging coil 4 strands 5, carried out by a tape brake, consisting of a brake pulley 6, which is bent around by a cord 7 (figure 2).

The tension of the strand is regulated by tensioning or loosening the brake cord 7, by means of a spring-loaded ratchet mechanism 8, which creates the necessary braking torque on the coils 4 with strands 5.

The rotor 1 is driven into rotation from the gearbox 9, and the rotor 2 from the gearbox 10 and the motor 11.

For unwinding the core there is a releasing device 12. The rotors end with crimping devices 13.

Lubricating devices 14 apply lubricant to the surface of the curl layer.

An exhaust mechanism with a traction pulley 15 is common to both rotors.

The stacking mechanism 16 and the receiving 17 are also common.

The method of twisting a two-layer rope is as follows.

After refueling the rotor 1 of the rope machine with coils 4 with strands 5, operations are performed to create braking torque on the coils 4 and, accordingly, the tension of the strands 5 of the first layer of the rope. Using a dynamometer (conditionally not shown) determine the tension of each strand 5 of the first layer of the rope and the well-known formulas determine the coordinates of the displacement of the resultant tension of the strands 5 of the first layer (figure 3):

as well as the magnitude of the bending moment of the first layer

and the magnitude of the angular displacement

,

- смещение равнодействующей в первом слое относительно оси Х и Y;

,

- координаты прядей каната относительно оси Х и Y,

- натяжение i пряди первого слоя каната; е₁ - смещение равнодействующей натяжений прядей 1-го слоя; φ - полярный угол (угловое смещение);

- суммарное значение равнодействующей натяжения прядей 1-го слоя.Where

,

- offset resultant in the first layer relative to the axis X and Y;

,

- the coordinates of the strands of the rope relative to the axis X and Y,

- tension i strands of the first layer of the rope; e ₁ - the offset of the resultant tension strands of the 1st layer; φ is the polar angle (angular displacement);

- the total value of the resultant tension of the strands of the 1st layer.

Then perform the operation of tensioning the strands in the second layer of the rope by adjusting the braking torque on the coils 4 by means of a belt brake and, accordingly, tensioning the strands 5 (Fig. 2) so that the generated bending moment is equal in magnitude to the bending moment of the first layer of strands 5 and opposite towards. Why use the value of the angular displacement, determined by the formula (4) (figure 3).

Tests conducted when twisting a two-layer rope with a diameter of 10 mm, implemented by the proposed method on a rope machine, showed that when creating a bending moment in the second layer of the rope, equal in magnitude to the bending moment of the first layer of strands and opposite in direction, the appearance of a waviness defect (difference geometric parameters and mechanical properties of screw elements).

Claims (2)

1. The method of twisting a two-layer rope, including the operation of twisting the first layer of strands, and then the second layer of strands around the core, characterized in that when performing the operation of twisting the first layer of strands, the strains of each strand of the first layer are measured and the radial and angular displacement of the resultant tension relative to the longitudinal axis is determined the rope and the magnitude of the bending moment, and before stranding the second layer of strands of the rope, each strand is tensioned so that the bending moment is equal in magnitude to the bending moment entom of the first layer of strands and opposite in direction. 2. The lay method according to claim 1, characterized in that the radial and angular displacement of the resultant tension and the magnitude of the bending moment are determined by the formulas

_;

_;

_;

, Where

,

- the offset of the resultant tension relative to the axis X and Y;

,

- the coordinates of the strands of the rope relative to the axis X and Y;

- tension i strands of the first layer of the rope; φ is the polar angle (angular displacement); e _i is the displacement of the resultant tension of the strands of the i-th layer;

- the total value of the resultant tension of the strands of the i-th layer.

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