TECHNICAL FIELD
[0001] The present invention relates to an elevator rope in which an outer circumference
is covered by a resin outer layer coating body.
BACKGROUND ART
[0002] 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.
[0003] 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]
[0004] Japanese Utility Model No.
3092239 (Gazette)
SUMMARY OF THE INVENTION
PROBLEM TO BE SOLVED BY THE INVENTION
[0005] 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.
[0006] 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
[0007] 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
[0008] 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
[0009]
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
[0010] Preferred embodiments of the present invention will now be explained with reference
to the drawings.
Embodiment 1
[0011] 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.
[0012] 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.
[0013] 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.
[0014] 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.
[0015] 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.
[0016] 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.
[0017] 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.
[0018] 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.
[0019] 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.
[0020] 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.
[0021] 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.
[0022] 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.
[0023] 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.
[0024] 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.
[0025] 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.
[0026] 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.
[0027] 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.
[0028] 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.
[0029] 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.
[0030] 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.
[0031] 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.
[0032] 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.
[0033] 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.
[0034] 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.
[0035] 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.
[0036] 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.
[0037] 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.
[0038] 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.
[0039] 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
[0040] 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.
[0041] 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.
[0042] 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.
[0043] 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.
[0044] 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".
[0045] 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.
[0046] 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.
[0047] 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.
[0048] 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.
[0049] 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.