EP2592033A1

EP2592033A1 - Elevator rope

Info

Publication number: EP2592033A1
Application number: EP10854422.2A
Authority: EP
Inventors: Atsushi Mitsui; Michio Murai
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2010-07-07
Filing date: 2010-07-07
Publication date: 2013-05-15
Anticipated expiration: 2030-07-07
Also published as: WO2012004867A1; JP5377769B2; EP2592033B1; CN102958822A; JPWO2012004867A1; EP2592033A4; KR101337845B1; CN102958822B; KR20130031263A

Abstract

In an elevator apparatus, a car is suspended by an elevator rope inside a hoistway. The elevator rope includes: a rope main body; and a resin outer layer coating body that is coated onto an outer circumference of the rope main body. Test result information that corresponds to a given position of a test that is carried out in a rope longitudinal direction during manufacturing is applied to a surface of the outer layer coating body at a predetermined pitch.

Description

TECHNICAL FIELD

The present invention relates to an elevator rope in which an outer circumference is covered by a resin outer layer coating body.

BACKGROUND ART

In conventional elevator ropes, since abnormalities and damage can be confirmed from external appearance of the ropes by visual inspection in most cases, it has been possible carry out a certain amount of inspection before actual use. In contrast to that, in elevator ropes in which an outer circumference is covered by a resin coating body, it has not been possible to confirm coating thickness or the presence or absence of internal wire breakages by visual inspection.
In conventional fiber ropes for construction, a synthetic resin coating layer is disposed on an outer circumference of a fiber rope main body, and a manufacturing or selling period is printed on the surface of this synthetic resin coating layer at a predetermined pitch (see Patent Literature 1, for example).

CITATION LIST

PATENT LITERATURE

[Patent Literature 1]

Japanese Utility Model No. 3092239 (Gazette)

SUMMARY OF THE INVENTION

PROBLEM TO BE SOLVED BY THE INVENTION

In conventional resin-coated elevator ropes such as that described above, coating thickness and the presence or absence of internal wire breakages are tested during manufacturing, but it has not been possible to detect abnormalities in the rare event that a product that has an abnormality is shipped erroneously, because it is difficult to find portions that have abnormalities by visual inspection, unless the entire length of all of the ropes are tested during maintenance inspections, or a wire breakage detecting apparatus that detects internal wire breakage is installed. Even if the manufacturing period is printed on the coating, although the service life of the normal rope can be estimated, it has still not been possible to detect abnormalities in the rare event that a product that has an abnormality is shipped erroneously, unless maintenance inspections are carried out or wire breakage detecting apparatuses are installed.
The present invention aims to solve the above problems and an object of the present invention is to provide an elevator rope in which test results during manufacturing can be easily confirmed visually in each portion even after shipment.

MEANS FOR SOLVING THE PROBLEM

In order to achieve the above object, according to one aspect of the present invention, there is provided an elevator rope including: a rope main body; and a resin outer layer coating body that is coated onto an outer circumference of the rope main body, wherein test result information that corresponds to a given position of a test that is carried out in a rope longitudinal direction during manufacturing is applied to a surface of the outer layer coating body at a predetermined pitch.

EFFECTS OF THE INVENTION

In an elevator rope according to the present invention, because the test result information that corresponds to a given position of a test that is carried out in a rope longitudinal direction during manufacturing is applied to the surface of the outer layer coating body at a predetermined pitch, the results of tests during manufacturing can be easily checked visually in each portion even after shipment.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a side elevation that shows an elevator rope according to Embodiment 1 of the present invention;
Figure 2 is a cross section of the elevator rope in Figure 1;
Figure 3 is a side elevation that shows an elevator rope according to Embodiment 2 of the present invention; and
Figure 4 is a side elevation that shows an example of an elevator apparatus to which the elevator rope according to Embodiment 1 or 2 is applied.

DESCRIPTION OF EMBODIMENTS

Preferred embodiments of the present invention will now be explained with reference to the drawings.

Embodiment 1

Figure 1 is a side elevation that shows an elevator rope according to Embodiment 1 of the present invention, and Figure 2 is a cross section of the elevator rope in Figure 1. In the figures, a single steel core strand 1 is disposed centrally in an elevator rope. A resin core strand coating body 2 is disposed on an outer circumference of the core strand 1. A plurality of (in this case, eight) steel core rope strands 3 are twisted together on an outer circumference of the core strand coating body 2.
A resin core rope coating body 5 is disposed on an outer circumference of a core rope strand assembly 4 that is constituted by the eight core rope strands 3 and the core strand coating body 2. A core rope 6 is constituted by the core strand 1, the core strand coating body 2, the core rope strands 3, and the core rope coating body 5.
A plurality of (in this case, twenty) steel outer layer strands 7 are twisted together on the outer circumference of the core rope coating body 5. A rope main body 8 is constituted by the core rope 6 and the outer layer strands 7. A resin outer layer coating body 9 is disposed on the outer circumference of the rope main body 8. The outer layer strands 7 and the outer layer coating body 9 are fixed using an adhesive.
All of the strands, including the core strand 1, the core rope strands 3, and the outer layer strands 7, are compressed (plastic working) from an outer circumference by a die during manufacturing to modify cross-sectional shapes of wires therein.
The core strand 1 and the core rope strands 3 have three-layer constructions in which two layers of wires are bound on an outer circumference of a central wire. The cross-sectional constructions of the core strand 1 and the core rope strands 3 are Seale. In addition, the lay lengths of the two layers of wires in the core strand 1 and the core rope strands 3 are equal. In other words, the core strand 1 and the core rope strands 3 are constituted by parallel lays. The outer layer strands 7 have a two-layer construction in which a single layer of wires is bound on an outer circumference of a central wire.
Resins that have a certain amount of hardness such as polyethylene or polypropylene, for example, are used as the materials for the core strand coating body 2 and the core rope coating body 5, since it is necessary to bear pressure from the core rope strands 3 and the outer layer strands 7. The core strand coating body 2 and the core rope coating body 5 are constituted by resins that are cross-linked by introducing a cross-linking agent.
In addition, the coefficients of friction of the core strand coating body 2 and the core rope coating body 5 should be reasonably low in order to increase flexibility of the elevator rope and also to reduce loss that occurs during flexing by the sheaves.
Thus, it is preferable for the materials of the core strand coating body 2 and the core rope coating body 5 to be harder than the material of the outer layer coating body 9 and to have lower coefficients of friction relative to identical metal materials. In addition, it is preferable for the core strand coating body 2 and the core rope coating body 5 to have superior wear resistance since slippage arises against the core strand 1, the core rope strands 3, and the outer layer strands 7.
Since it is necessary to ensure traction capacity on the sheaves, the outer layer coating body 9 is constituted by a resin that has sufficient wear resistance at a coefficient of friction on the sheaves that is greater than or equal to 0.2, such as a polyurethane, for example. The outer layer strands 7 are constituted by a resin that is cross-linked by introducing a cross-linking agent.
It is preferable for the core strand coating body 2 and the core rope coating body 5 to enter between the adjacent core rope strands 3 and be in contact with each other as shown in Figure 2, even when subjected to tension during use. It is also preferable for the core rope coating body 5 and the outer layer coating body 9 to enter between the adjacent outer layer strands 7 and be in contact with each other as shown in Figure 2, even when subjected to tension during use.
Test result information 31 that corresponds to a given position of tests that are carried out during manufacturing and rope longitudinal position information 32 are applied to a surface of the outer layer coating body 9 at a predetermined pitch. The test result information 31 and the position information 32 are printed on the outer layer coating body 9 using a printer or a laser marker, for example.
The tests during manufacturing are carried out after coating of the outer layer coating body 9 in the manufacturing step, or in a testing step that is separate from the manufacturing step. The tests during manufacturing are carried out continuously and at a predetermined pitch in a longitudinal direction of the rope.
Examples of content of the tests include a rope diameter test using a laser outside diameter measuring instrument, a coating thickness test using an ultrasonic wave sensor or an eddy current sensor, and a wire breakage test using a magnetic leakage rope tester, for example.
The respective results of the tests are recorded separately in association with a batch number and a longitudinal position, and an overall determined result of all of the tests is applied to the outer layer coating body 9. Specifically, if the results of all of the tests are free of abnormality, "OK" is printed, and if there is even a single abnormality, "NG" is printed.
Generally, an elevator rope is manufactured to a length from 2,000 mm to 6,000 m, and then cut to a required length depending on the elevator apparatus in which it will be used. If the test result information 31 is "NG", then the elevator rope is produced by cutting so as to avoid that portion. Depending on the test item and the extent that the abnormality is detected, overall production of the elevator rope may also be postponed.
A manufactured length, i.e., a length from an end portion during manufacturing (before cutting), is applied to the outer layer coating body 9 as the position information 32. In the example in Figure 1, the manufactured length is applied every 0.1 m.
The test result information 31 and the position information 32 are applied to identical circumferential positions on the outer layer coating body 9. In other words, the test result information 31 and the position information 32 are applied in a single straight line that is parallel to the axis of the elevator rope.
In an elevator rope of this kind, because the test result information 31 is applied to the surface of the outer layer coating body 9 at a predetermined pitch, the results of tests during manufacturing can be easily checked visually in each portion even after shipment. Consequently, it is possible to recheck the test results from the external appearance of the elevator rope during testing time before delivery or during installation of the elevator apparatus, not only before shipment, but even after the product has been shipped. Because of this, even if an elevator rope that includes a portion in which an abnormality has been detected is shipped erroneously for some reason, that elevator rope can be easily found.
Because the position information 32 is recorded together with the test result information 31, collation between the test data and the actual article is facilitated. In addition, if an abnormal point or a portion that requires testing continuously arises during a maintenance inspection of an elevator rope that is in use, the position thereof on the elevator rope can be ascertained immediately as a numerical value. Furthermore, if the elevator rope is to be cut to a required length, it is no longer necessary to use a special length measuring machine separately.
By recording in advance which portions of the elevator rope are positioned at guide positions that are disposed on the hoisting machine, when the car is to be stopped at a floor alignment position, the car can be moved to the floor alignment position precisely, when operating the hoisting machine manually to carry out a rescue operation, for example.
In addition, by applying the test result information 31 and the position information 32 in a straight line, and reducing the print pitch to a certain extent, the degree of twisting of the elevator rope can be checked when the car and the counterweight are suspended.
Now, it is also desirable for the print pitch to be within two pitches of the lay pitch of the outer layer strands 7 in order to check the lay. In other words, making the pitch as short as possible makes the printing like a continuous line, and is preferable for checking the lay. However, when printing length is taken into consideration, less than a single pitch is often difficult. At three pitches or more, on the other hand, it is difficult to determine whether distortion of the printing is due to rotation of the elevator rope, or whether it is due to tightening or unwinding of the lay.
A single pitch of the lay of the outer layer strands 7 is normally in the order of 6.5 times an elevator rope diameter. If the elevator rope diameter is 12 mm, for example, a single pitch of the lay is in the order of 70 through 80 mm, and two pitches of the lay are in the order of 140 through 160 mm. Consequently, the print pitch of 100 mm that is shown in Figure 1 can be said to be within a preferred range.
In an elevator rope that has an outer layer coating body 9, the coefficient of friction between the outer layer coating body 9 and a driving sheave is large, making slippage of the elevator rope relative to the driving sheave less likely to occur. Because of this, the test result information 31 and the position information 32 are less likely to be ablated by abrasion. If, however, it is anticipated that the printing will disappear during use due to operating conditions, etc., it is preferable for the printing depth of the test result information 31 and the position information 32 to be deepened using a laser marker, etc.
In an elevator rope such as that described above, since only one core strand 1 is used, deformation is less likely to occur when tension acts during use and a load is applied to the core strand 1 from the core rope strands 3, enabling the cross-sectional shape of the entire elevator rope to be stabilized, and steps for twisting the strands together can be reduced, enabling manufacturing to be facilitated. Since the core rope strands 3 are also twisted onto the outer circumference of the core strand coating body 2 without being twisted directly onto the outer circumference of the core strand 1, the cross-sectional shape of the core rope 6 can be made less prone to deform, thereby also enabling the cross-sectional shape of the entire elevator rope to be stabilized.
In addition, since none of the strands, including the core strand 1, the core rope strands 3, and the outer layer strands 7, contact other strands directly, abrasive wear due to contact among the strands is prevented, enabling extension of the service life of the elevator rope.
Furthermore, in order to generate traction on the sheaves, it is necessary to fix the outer layer coating body 9 to the outer layer strands 7 adhesively, and it is necessary to wash away extraneous contamination or oil satisfactorily during manufacturing of the outer layer strands 7 before fixing the outer layer coating body 9 to the outer layer strands 7 adhesively. Satisfactory washing in interior portions of the outer layer strands 7 is not possible if the construction of the outer layer strands 7 is complicated. In answer to that, because the core strand 1 and the core rope strands 3 have three-layer constructions and the outer layer strands 7 have two-layer constructions in Embodiment 1, sufficient strength is ensured and the outer layer strands 7 are also sufficiently and easily washed, enabling the outer layer coating body 9 to be fixed firmly to the outer layer strands 7 adhesively.
Because the core strand coating body 2 and the core rope coating body 5 are constituted by cross-linked resin materials, durability is increased against temperature increases due to use in high-temperature environments or due to the continuous action of flexing, etc., enabling service life to be extended.
In addition, because the outer layer coating body 9 is also constituted by a cross-linked resin material, durability is increased against temperature increases due to use in high-temperature environments or due to the continuous action of flexing, etc., enabling service life to be extended. Deterioration in strength from temperature increases due to slippage between the sheaves and the elevator rope during emergency braking can also be prevented, enabling sufficient deceleration performance to be maintained.

Embodiment 2

Next, Figure 3 is a side elevation that shows an elevator rope according to Embodiment 2 of the present invention. In the figure, manufacturing information 33 is recorded on a surface of an outer layer coating body 9 in addition to test result information 31 and position information 32. Examples of manufacturing information 33 include a manufacturer's name, a batch number, and a manufacturing date.
The manufacturing information 33 is printed at a pitch equal to that of the test result information 31 and the position information 32 in a longitudinal direction of a rope. In addition, the manufacturing information 33 is printed so as to be offset to a position that is different than that of the test result information 31 and the position information 32 in a circumferential direction of the outer layer coating body 9. The rest of the configuration is similar or identical to that of Embodiment 1.
In an elevator rope of this kind, because the manufacturing information 33 is applied to the outer layer coating body 9 at a predetermined pitch in the longitudinal direction of the rope, information that relates to manufacturing can be checked visually on the actual article itself without having to dispose a separate data plate.
Moreover, the cross-sectional construction of the elevator rope according to the present invention is not limited to the construction in Figure 2. It may also be a construction in which shaping is not applied to the core strand 1, or a construction in which the respective numbers of core rope strands 3 and outer layer strands 7 are reduced (six core rope strands and sixteen outer layer strands, for example), or a two-layer construction in which the core rope strands 3 and the core rope coating body 5 are omitted, for example.
In Embodiments 1 and 2, an elevator rope that has a circular cross section is shown, but "elevator rope" as it is expressed in the present invention is used in the broadest sense, and also includes ropes that have flat cross-sectional shapes, such as belts.
In addition, in Embodiments 1 and 2, an overall result of all of the tests is applied to the outer layer coating body 9 as the test result information 31, but the test result information 31 may also represent the results for each of the tests. In that case, the test result information 31 can be displayed compactly if the test results are displayed so as to be coded in a predetermined sequence. The results of the rope diameter test, the coating thickness test, and the wire breakage testing that are described above can be represented by a three-digit numeral using a "0" if free of abnormality, and a "1" if an abnormality is present, for example. The presence or absence of abnormalities can also be represented by a sequence of symbols such as "O" or "X".
Now, Figure 4 is a side elevation that shows an example of an elevator apparatus to which the elevator rope according to Embodiment 1 or 2 is applied. In the figure, a machine room 12 is disposed in an upper portion of a hoistway 11. A machine base 13 is installed inside the machine room 12. A hoisting machine 14 is supported on the machine base 13. The hoisting machine 14 has a driving sheave 15 and a hoisting machine main body 16. The hoisting machine main body 16 has: a hoisting machine motor that rotates the driving sheave 15; and a hoisting machine brake that brakes the rotation of the driving sheave 15.
A deflecting sheave 17 is mounted to the machine base 13. A plurality of elevator ropes 18 that function as a suspending means are wound around the driving sheave 15 and the deflecting sheave 17. Portions of the elevator ropes 18 that are nearer to the counterweight 10 than the driving sheave 15 are wound around the deflecting sheave 17.
A car 19 is suspended on first end portions of the elevator ropes 18. Specifically, the car 19 is suspended inside the hoistway 11 by the elevator ropes 18 on a first side of the driving sheave 15. A counterweight 20 is suspended on second end portions of the elevator ropes 18. Specifically, the counterweight 20 is suspended by the elevator ropes 18 on a second side of the driving sheave 15.
A pair of car guide rails 21 that guide raising and lowering of the car 19 and a pair of counterweight guide rails 22 that guide raising and lowering of the counterweight 20 are installed inside the hoistway 11. Emergency stopper apparatuses 23 that make the car 19 perform an emergency stop by engaging with the car guide rail 21 are mounted to the car 19.
Moreover, the type of elevator apparatus to which the elevator rope according to the present invention is applied is not limited to the type in Figure 4. For example, the present invention can also be applied to machine-roomless elevators, elevator apparatuses that use two-to-one (2:1) roping methods, multi-car elevators, or double-deck elevators.
The elevator rope according to the present invention can also be applied to ropes other than ropes for suspending a car 19, such as compensating ropes or governor ropes, for example.

Claims

An elevator rope comprising:
a rope main body; and

a resin outer layer coating body that is coated onto an outer circumference of the rope main body,
wherein test result information that corresponds to a given position of a test that is carried out in a rope longitudinal direction during manufacturing is applied to a surface of the outer layer coating body at a predetermined pitch.
An elevator rope according to Claim 1, wherein rope longitudinal position information is recorded on the surface of the outer layer coating body together with the test result information.
An elevator rope according to Claim 1, wherein:
the rope main body includes a plurality of strands that are laid on an outer circumference thereof; and

the pitch at which the test result information is applied is within two pitches of a lay pitch of the strands.