JP2892842B2 - Wire rope - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire rope in which a plurality of strands are twisted around a core rope, and more particularly to a wire rope suitable for use in an elevator, a crane, a lift, and the like.

[0002]

2. Description of the Related Art In general, when a wire rope is provided in an elevator, a crane, a lift, or the like, it is wound around a traction sheave or a load is applied in a wound state. And high fatigue strength are required. 7 is a cross-sectional view showing a conventional wire rope for an elevator, and FIG. 8 is a cross-sectional view of a core rope before being incorporated into the wire rope of FIG.

[0003] In order to satisfy the above-mentioned requirements, the conventional wire rope shown in FIG. 7 has a core rope 1 at the center and a plurality of, for example, eight steel wire strands twisted around the core rope 1. The steel wire strand 2 is formed by twisting a large number of thin steel wires 3.

The above-described core rope 1 has a so-called three-strand configuration and is composed of three hemp strands 4, as shown in FIG. 8, for example. It is formed by twisting a large number of natural fibers such as sisal hemp and manila hemp and impregnating with lubricating oil.

In such a conventional wire rope, FIG.
Is different from the outline shape of the core rope 1 shown in FIG. 7 and the outline shape of the core rope 1 in a state where the steel wire strand 2 is twisted around as shown in FIG. That is, the core wire 1 is greatly deformed by twisting the steel wire strands 2 around, and in this state, the core wire 1 is closely adhered to the steel wire strands 2 without any gap and is adapted. In addition, since this wire rope includes eight steel wire strands 2,
Vibration can be prevented during traveling of the car, as compared with a car having six ordinary steel wire strands.

[0006] The eight-strand wire rope of the organic fiber core type having the core obtained by twisting the natural fibers as described above has the following various advantages.

[0007] Noise and vibration when the wire rope engages with the traction sheave and pulleys tend to increase as the operating speed of the car increases, but the eight-strand wire rope has a degree of irregularity in its outer shape. Since the size is smaller than that of the six-strand wire rope, the above noise and vibration can be reduced.

In the eight-strand wire rope, the ratio of the cross-sectional area of the core to the cross-sectional area of the wire rope is larger than that of the six-strand wire rope, so that the spring constant with respect to the tension of the wire rope is appropriately low. Become.
For this reason, pulsation and the like due to meshing of the gears of the traction machine can be more easily absorbed, and vibration of the car can be prevented.

A mandrel formed by twisting natural fibers such as sisal hemp and manila hemp has appropriate plasticity, that is, internal loss, against bending deformation and elongation deformation of the wire rope. High damping capacity against longitudinal vibration.

In particular, in the case of a wire rope for an elevator, in order to reduce noise and vibration when the wire rope is engaged with a sheave, a design in which the number of wire ropes is increased instead of increasing the outer diameter of the wire ropes is preferred. And when the number of wire ropes increases, it is inevitable that adjacent wire ropes collide with each other due to rolling and emit a collision sound,
With the eight-strand wire rope having the mandrel, a dull and low collision sound is sufficient at the time of the above collision.

In a flexible wire rope having a large number of strands, when the wire rope comes into contact with the rope groove surface of the traction sheave, the contact points are dispersed in many places. The Hertzian surface pressure in contact with the strand is reduced, and the wear on the rope groove surface is reduced. Further, wear of the outer layer wire of the wire rope due to the Hertzian contact pressure is reduced, and the wear life of the wire rope is extended.

[0012] A core rope formed by twisting natural fibers such as sisal hemp and manila hemp has a high oil-impregnating ability when impregnated with rope oil, and thus lubrication and rust prevention of wire ropes of elevators used for a long period of time. Suitable for. In particular, the eight-strand wire rope has a high oil-impregnating capacity because the cross-sectional area ratio of the core is large as described above.

[0013] The agitating resistance of the air exerts a significant vibration-damping action on the low-frequency, large-amplitude rolling of the wire rope.
The eight-strand wire rope of the organic fiber core type is advantageous in obtaining air resistance because it is light in weight for the sectional area.

[0014]

The above-mentioned conventional wire rope, for example, has the following disadvantages when used in an elevator.

The traction sheave is wound around the traction sheave in a state in which a riding weight and a counterweight are hung on both ends of the wire rope, and is driven by a frictional force between the wire rope and the sheave groove. In order to obtain a sufficient frictional force, it is necessary to make the wire rope bite into the sheave groove like a wedge. Therefore, the sheave groove of the traction sheave is
The sheave groove is not formed in a simple round groove shape, but is formed in the following shape, for example.

FIG. 9 is a sectional view showing a state where the wire rope is engaged with the round groove with an undercut, and FIG. 10 is a sectional view showing a state where the wire rope is engaged with the V-groove.

At the bottom of the round groove 5 shown in FIG. 9, an undercut process is performed to provide a square bottom 6. in this case,
The wire rope is subjected to strong lateral pressure P ₁ from the ridge line between the round groove 5 and Sumisoko portion 6, the cross-sectional shape resulting in a collapse deformation closer to a triangle. Similarly, as shown in FIG.
Even when the groove 7, the wire rope is subjected to strong lateral pressure P ₂ from the left and right inclined surfaces of the V-grooves 7, the cross-sectional shape resulting in a collapse deformation closer to a triangle.

As described above, when the wire rope engages with the undercut round groove 5 or the V-groove 7, the local bending stress generated by the wire rope being strongly pressed is the element of the wire rope performed by the present applicant. According to the numerical analysis of linear stress,
It has been found that it is greater than simple tensile stress (tension-based stress) and simple bending stress (bending stress that occurs when bent around a sheave) and can be a dominant component in the overall composite stress. In the numerical analysis performed by the present applicant, the variational method was used because the numerical analysis of the actual wire stress of the wire rope was extremely difficult. However, it was difficult to measure the actual stress. Therefore, it is difficult to calibrate the above analysis result by comparing it with the measured stress. The above numerical analysis of the wire stress of the wire rope is obtained as follows. That is, first, as is clear from various regulations concerning the safety factor of the wire rope, the conventional theory regarding the stress of the wire of the wire rope is based on the following formula.

[0019]

Σt = T / A

[0020]

Σb = Er × δ / D where σt: stress based on tension (kgf / mm ² ),
σb: bending stress (kgf / mm ² ) generated when bent around the sheave, T: tension (kgf), A: total cross-sectional area of wire (mm ² ), Er: elastic modulus of wire rope ( kgf / mm ² ), δ: diameter of wire (mm), D: diameter of sheave (mm).

FIG. 11 is a characteristic diagram showing the relationship between the rigidity of the core rope and the stress generated in the outer strand of the wire rope. In FIG. 11, for example, eight strand ropes are used as shown in FIG.
9 shows the results of calculating the combined stress applied to the outer layer strands when engaging with the round groove 5 with the undercut of 90 ° as shown in FIG. The angle θ (0 °-
180 °) is plotted on the horizontal axis, and the combined stress applied to the outer layer strand at each angle θ is plotted on the vertical axis.

As shown in FIG. 11, the resultant stress is
The peak value is reached at an angle θ of 45 °, and this peak value tends to decrease as the rigidity G (lateral elastic modulus) of the core rope increases, and increase as the rigidity G decreases. That is, the rigidity G of the core rope has a very large effect on the degree of the resultant stress applied to the outer layer strand of the wire rope, and it can be said that it is important to improve the rigidity G of the core rope. Further, when the wire rope is engaged with the groove with an undercut or the V-groove, when the rigidity G of the core rope is low, the core rope is crushed, so that the outer rope is strong at the contact position between the wire rope and the sheave groove. The occurrence of local bending stress is supported by the results of the above numerical analysis.

As described above, the cross-sectional shape of the wire rope is crushed and deformed. As a result, the rotation of the wire rope is hindered during the reciprocating operation of the car, so that only a specific outer layer element wire on the outer periphery is used. The traction sheave comes into contact with the groove surface of the traction sheave, and the portion is worn intensively, so that the rope life is significantly shortened. In particular, the eight-strand wire rope has a larger deformation amount than the six-strand wire rope and tends to remain as permanent deformation. The presence or absence of this permanent deformation is closely related to preventing the wire rope from rotating, and has a great influence on the life of the rope. In the absence of the above-mentioned crush deformation, when the reciprocating operation of the car is repeated, the wire rope rotates by itself, and the position on the outer periphery of the wire rope that comes into contact with the groove surface of the traction sheave is changed. Wire abrasion and disconnection of the outer peripheral portion of the wire rope occur uniformly over the entire outer peripheral portion, and as a result, the life of the rope is prolonged.

Since wire ropes for elevators are always under tension, the initial elongation and the aging of the wire rope are relatively large, so that the wire rope must be cut down frequently. Further, a plurality of wire ropes may be unevenly stretched, and the tension applied to each wire rope is likely to vary.

In a core line in which a natural fiber is simply twisted and impregnated with a lubricating oil, crushing deformation and elongation deformation are liable to occur due to a small frictional force between the fibers that maintain the shape of the core line itself. With the deformation of the rope, the crushing deformation and the stretching deformation of the entire wire rope easily occur.

As a means for solving such a problem, for example, without changing the structure of the wire rope, a tension of about 30 to 40% of the breaking strength of the wire rope is repeatedly applied in advance to the core rope. A pretensioning method for improving the tightness and the familiarity with the strand has already been put to practical use. Also, a post-form processing method has been already put into practical use in which the wire rope is passed between rollers arranged in a zigzag arrangement while applying a certain amount of tension, thereby improving the tightness of the core rope and the familiarity with the strand. It has been empirically confirmed that both the pretensioning method and the postform processing method have an effect of extending the rope life to some extent. However, since the configuration of the wire rope is not changed, it is difficult to prevent the fibers of the core rope from shifting between each other.

Further, in order to prevent the wire rope from being crushed and stretched, a steel core wire having seven strands provided with a wire strand at the center of the six strands is used as a base, based on a normal wire rope having six strands. Rope is for applications other than elevators. This steel core wire rope is not suitable for an elevator because it does not have the above-mentioned advantages.

Further, a steel core wire rope having nine strands in which another strand is provided at the center position of the eight strands based on the eight strand ropes so that it can be used for an elevator is also used for the elevator. It has been put to practical use. In this steel core wire rope, the space for accommodating the natural fibers impregnated with the lubricating oil is limited to a small gap between the outer periphery of the central strand and the inside of the surrounding strand, so that the above advantages are slightly reduced. This is problematic for elevators. Therefore, it has been limited to some models that are not so severe in terms of vibration and noise.

The present invention has been made in view of such circumstances in the prior art, and its object is to not only prevent wire breakage, crushing deformation and elongation deformation, but also ensure flexibility and lubricity. It is to provide a wire rope that can be used.

[0030]

SUMMARY OF THE INVENTION To achieve this object, the present invention comprises a core line impregnated with lubricating oil and a plurality of strands twisted around the core line. In a wire rope consisting of a number of metal strands twisted with each other, the core rope is made of a non-fibrous elastic body that is more flexible than the metal strands and does not include a lubricating oil having a non-circular cross section. It is configured to include a core part forming the rod-shaped body of the book, and an oil-impregnated part made of a material softer than the metal strand and wound around the core part and containing the lubricating oil.

[0031]

According to the present invention, as described above, the core of the core rope is made of non-fiber.
Since it is made of an elastic material that is a fiber and has a non-circular cross-section and does not contain lubricating oil, it forms a single rod-shaped body. The amount of elastic deformation of the rope and the amount of plastic deformation of the core after the load is removed can be reduced, thereby preventing the wire rope from crushing and elongating due to the deformation of the core. can do. In addition, the core has relatively small elastic deformation as described above, that is, since the rigidity of the core is improved, the local bending stress of the strand is reduced, and therefore, it is possible to prevent the strand from breaking. Can be.

Since the above-mentioned core portion is formed of a non-fibrous elastic material, the flexibility of the wire rope is not significantly impaired. Since the oil-impregnated portion is provided on the outer peripheral portion of the core portion, when the wire rope is tensioned, the lubricating oil exudes from the oil-impregnated portion to lubricate the metal strand of the strand.

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a wire rope according to the present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view showing a first embodiment of the wire rope of the present invention, and FIG. 2 is a cross-sectional view of a core rope before being incorporated into the wire rope of FIG.

The wire rope of this embodiment shown in FIG.
It comprises a core mandrel 11 and a plurality of, for example, eight steel wire strands 12 twisted around the mandrel 11. Each strand 12 is composed of a large number of metal strands, for example, steel strands 13, which are twisted with each other.

The core rope 11 described above, as shown in FIG.
A core portion 14 formed of a non-fibrous elastic body such as plastic or rubber and formed on a single rod-like body having a non-circular cross section and containing no lubricating oil, and a lubricating oil provided on an outer peripheral portion of the core portion 14 And an oil-impregnated portion 15 containing the same. Core part 14
Is formed in a rod shape, and is provided with a groove 16 on the outer periphery by spline processing or knurling. The oil-impregnated portion 15 is made of hemp strands obtained by twisting a large number of natural fibers such as sisal hemp and manila hemp, and is tightly wound around the core portion 14 in a spiral manner.

On the outer periphery of the core rope 11 thus configured,
After twisting the eight steel wire strands 12, post-forming, pre-tensioning, etc.,
The mandrel 11 is deformed as shown in FIG.
1 is closely fitted to the steel wire strand 12 without any gap, and is adapted.

[0038] In the first embodiment, since the core portion 14 of the Shintsuna 11 is more integrally formed in the elastic body of the non-fibrous, and if the core rope is made of fiber strands or the like In comparison, the amount by which the core rope 11 undergoes elastic deformation under load,
The amount by which the core rope 11 undergoes plastic deformation when the load is removed can be small. As described above, the core rope 11 has relatively small elastic deformation, that is, since the rigidity of the core rope 11 is improved, the local bending stress of the steel strand 13 of the strand 12 is reduced.

In the first embodiment constructed as described above, when a force is applied to the core rope 11, the amount of elastic deformation or plastic deformation of the core rope 11 is small. Crush deformation and elongation deformation can be prevented. At this time, the oil-impregnated portion 15 is
Is prevented from slipping in the outer circumferential direction of the core line 11, the crushing deformation of the core rope 11 due to the slippage of the oil-containing portion 15 can be prevented. Further, since the local bending stress of the steel wires 13 of the strands 12 is reduced, breakage of the steel wires 13 can be prevented, and so-called trough breaks of the outer layer wires occur at portions where the adjacent strands 12 contact. Can be prevented. And since plastic deformation of the core part 14 is prevented, the elongation deformation of the core rope 11 can be suppressed and the amount of elongation of the wire rope can be reduced.

Since the core portion 14 is formed as a single rod from a non-fibrous elastic material such as plastic or rubber, which is more flexible than the steel wire 13, a wire strand is provided at the center position. Compared with the steel core wire rope, the flexibility of the wire rope is not significantly impaired.

Since the steel wire 13 of the strand 12 is lubricated by the lubricating oil that has exuded from the oil impregnated portion 15, the frictional force on the surface of the steel wire 13 can be reduced and rusting can be prevented.

In the first embodiment, the oil-containing portion 15
Although natural fibers were used, synthetic fibers, glass fibers, carbon fibers, and the like can be used as necessary in place of the natural fibers. Further, in this embodiment, the case of eight strand ropes has been exemplified, but the present invention is not limited to this, and can be applied to the case of a wire rope having another number of strands.

FIG. 3 is a sectional view showing a second embodiment of the wire rope of the present invention, and FIG. 4 is a sectional view of a core rope before being incorporated into the wire rope of FIG.

The wire rope of this embodiment shown in FIG.
It comprises a core mandrel 21 and a plurality of, for example, eight steel wire strands 22 twisted around the mandrel 21. Each strand 22 is composed of a large number of metal strands, for example, steel strands 23 that are twisted with each other.

As shown in FIG. 4,
It comprises a core portion 24 integrally formed of a non-fibrous elastic material such as plastic or rubber, and an oil-containing portion 25 provided on the outer periphery of the core portion 24 and containing lubricating oil. The core portion 24 is formed in a polygonal shape that forms a non-circular shape, for example, a shape having an octagonal cross section, and is provided with a concave arc-shaped groove 26 that is spirally formed along the longitudinal direction of the core portion 24. ing. The twist pitch of the groove 26 is set equal to the twist pitch of the steel wire strand 22. Oil impregnated part 2
Reference numeral 5 denotes a hemp strand in which a large number of natural fibers such as sisal hemp and manila hemp are twisted, and is spirally densely wound around the outer periphery of the core part 24.

On the outer periphery of the core rope 21 thus configured,
After twisting the eight steel wire strands 22, post-forming, pre-tensioning, etc.,
The mandrel 21 is deformed as shown in FIG.
1 is closely fitted to the steel wire strand 22 without any gap, and is adapted.

In the second embodiment, the same effects as those in the first embodiment can be obtained.

Although the second embodiment uses natural fibers for the oil- containing portion 25 , synthetic fibers, glass fibers, carbon fibers, and the like may be used as necessary in place of the natural fibers. Further, in this embodiment, the case of eight strand ropes has been exemplified, but the present invention is not limited to this, and can be applied to the case of a wire rope having another number of strands.

FIG. 5 is a sectional view showing a third embodiment of the wire rope of the present invention, and FIG. 6 is a sectional view of a core rope showing a state before being incorporated into the wire rope of FIG.

The wire rope of this embodiment shown in FIG.
It comprises a core mandrel 31 and a plurality of, for example, eight steel wire strands 32 twisted around the mandrel 31. Each strand 32 is composed of a large number of metal wires, for example, steel wires 33, which are twisted with each other.

As shown in FIG. 6, the core rope 31 described above
A core portion 34 formed of a single rod-shaped body containing no lubricating oil and made of a non-fibrous elastic body such as plastic or rubber;
An oil-impregnated portion 35 containing lubricating oil is provided on the outer peripheral portion of the core portion 34. The core portion 34 is formed in a rod shape having a polygonal shape, for example, an octagonal cross section, and has a concave arc-shaped groove 36 spirally formed along the longitudinal direction of the core portion 34.
Is provided. The twist pitch of the groove 36 is set equal to the twist pitch of the steel wire strand 32. The oil-impregnated portion 35 is composed of eight hemp strands 37 made by twisting a large number of natural fibers such as sisal hemp and manila hemp. These hemp strands 37 are wound so as to engage with the grooves 36 on the outer periphery of the core portion 34.

On the outer periphery of the core rope 31 thus configured,
After twisting the eight steel wire strands 32, post-forming, pre-tensioning, etc.,
The mandrel 31 is deformed as shown in FIG.
1 is closely fitted to the steel wire strand 32 without any gap, and is adapted.

In the third embodiment, the same effects as those in the first embodiment can be obtained.

Although the third embodiment employs natural fibers for the oil-impregnated portion 35 , synthetic fibers, glass fibers, carbon fibers, and the like may be used as necessary in place of the natural fibers. Further, in this embodiment, the case of eight strand ropes has been exemplified, but the present invention is not limited to this, and can be applied to the case of a wire rope having another number of strands.

[0055]

As described above, according to the present invention, the local bending stress of the strand can be reduced to prevent the strand from breaking, and the life of the wire rope can be extended. At the same time, by preventing the wire rope from crushing deformation and holding the wire rope in a shape that easily rotates, wire wear and disconnection of the wire rope outer peripheral portion can be uniformly generated over the entire outer peripheral portion, and therefore Thus, the life of the above-described wire rope can be further extended. Even under severe conditions where the rotation of the wire rope is hindered, the local bending stress at the contact portion of the wire rope decreases with the improvement in the rigidity of the core rope,
Even in this case, the life of the wire rope can be extended. Since the amount of elongation of the wire rope is reduced, the interval at which the wire rope is cut off can be increased, and the tension applied to the plurality of wire ropes can be prevented from being varied.

Further, since the above-mentioned wire rope has a greater flexibility than a steel core wire rope having a wire strand provided at the center position, the wire rope comes into contact with the rope groove surface of the traction sheave. Therefore, the contact points can be dispersed in many places, and therefore, the wear of the rope groove surface and the wear of the wire rope can be reduced. And since a wire rope also has lubricity, lubrication and rust prevention of a wire rope surface can be performed, and therefore, a wire rope suitable for an elevator used for a long period of time can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of a wire rope according to the present invention.

FIG. 2 is a sectional view of a core rope showing a state before being incorporated into the wire rope of FIG. 1;

FIG. 3 is a sectional view showing a second embodiment of the wire rope of the present invention.

FIG. 4 is a cross-sectional view of a core rope showing a state before being incorporated into the wire rope of FIG. 1;

FIG. 5 is a sectional view showing a third embodiment of the wire rope of the present invention.

FIG. 6 is a cross-sectional view of a mandrel showing a state before being incorporated into the wire rope of FIG. 1;

FIG. 7 is a sectional view showing a conventional wire rope for an elevator.

FIG. 8 is a sectional view of a core rope showing a state before being incorporated into the wire rope of FIG. 7;

FIG. 9 is a cross-sectional view showing a state in which the wire rope is engaged with a round groove with an undercut.

FIG. 10 is a cross-sectional view showing a state where a wire rope is engaged with a V groove.

FIG. 11 is a characteristic diagram showing a relationship between a rigidity of a core rope and a stress generated in an outer strand of a wire rope.

[Explanation of symbols]

 Reference Signs List 11 core rope 12 strand 13 steel strand (metal strand) 14 core part 15 oil impregnated part 21 core strand 22 strand 23 steel strand (metal strand) 24 core part 25 oil impregnated part 31 core strand 32 strand 33 steel strand (metal strand) Metal wire) 34 Core 35 Oil-impregnated

Claims (1)

(57) [Claims] 1. A wire rope comprising a core line impregnated with lubricating oil and a plurality of strands twisted around the core line, each wire comprising a number of metal strands twisted with each other. In the above, the core rope is formed of a non-fibrous elastic body that is more flexible than the metal element wire, and has a core portion that forms a single rod-shaped body that does not include a lubricating oil having a non-circular cross section, and the metal element wire A wire rope, which is made of a more flexible material and is wound around an outer peripheral portion of the core portion and comprises an oil-containing portion containing the lubricating oil.