DE60221320T2 - Dynamic rope and method and apparatus for producing such a rope - Google Patents

Abstract

The cable (9) is made from a number of strands (2) wound round a core (1), with the spaces between the strands and core filled with a polymer material. The polymer is applied in the form of a polymerizable compound by an injection head (15) situated upstream of the cabling point (13). The cable (9) is made from a number of strands (2) wound round a core (1), with the spaces between the strands and core filled with a polymer material. The polymer is applied in the form of a polymerizable compound by an injection head (15) situated upstream of the cabling point (13). The position of the head being determined so that the strands are wound round the core when the polymerisation is at a sufficiently viscoplastic state to ensure a continuous coating while being fluid enough to fill the spaces between the core and strands, and between the strands. The compound can be applied to the core alone or to the core and strands, and is made up just before application by mixing predetermined proportions of a pre polymer containing isocyanates and a polymerisation accelerator. The cable is made from core strands (5) from reels (11) and outer winding strands (2) from reels (14) passing through a cabling head (13) after the polymer injection head (15) with a mixing chamber connected to tanks containing the pre-polymer and polymerisation accelerator.

Description

The The invention relates to lifting and traction cables, including dynamic ropes called because they work normally under train, but at loads, which can vary greatly, also be subjected to bends. These are in particular around ropes for Hoists or traction vehicles, which are wound on the rope drum of a lift are.

The Ropes treated here are classically made from at least one Location made of steel wire strands that snail around a central core to be rolled up. The winding takes place by means of a stranding head enclosing the core, wherein the head turns on itself and the strands continuously arranges around the running central core around.

In particular, the properties required for the aforesaid ropes are high flexibility, regular rotary motion to ensure permanent, regular stretch, and high abrasion resistance. For additional information on the properties required for such ropes and the requirements they must meet, one can, for example, on the French Patent Application No. 93 08648 Respectively.

A for the ordinary purposes rope used is a cross-cut rope made of eight steel wire strands, the snail-shaped around a core of natural Hard-fiber fabrics, e.g. Sisal, to be rolled up. Is known also a similar one Rope whose core is mixed, i. made of steel strands and textile filling fibers consists. The dynamic ropes can also be ropes with steel strands on a dependent or independent Steel core act. For example, ropes with twelve outer strands are known, the on an independent Core wound as in the Warrington strand, or ropes with nine outer strands on an independent Steel core, which also consists of nine strands.

The relatively small radius of curvature, the The rope must form in applications of this type cause strong Bends of the entire rope, but produce especially strong Differences in the course of the individual strands and also between the Steel wires, which they consist of. So it comes to repeated relative Shifts of the strands with each other, which already wear and local Renewals due to easy friction can cause. It also causes the rope curvature when the rope is otherwise loaded, i. Subjected to tensile stresses will, strong cross pressures between the touching steel wires, causing a decrease in the lateral velocity of the rope is caused and wear it down quickly Bulges can come. These bulges decrease with the Time at certain points the wire cross-section and affect accordingly negative for the resistance and the lifetime of the Ropes off.

you already knows the use of natural fiber ropes, e.g. sisal or made of synthetic fibers (polypropylene) whose object is to to form a cushion between the individual layers of strands. In order to should the friction of the steel wires or strands together and the resulting bulges avoided or at least restricted. A common Point of these non-metallic material inserts is that they are not direct involved in the voltage recovery, i. not directly to increase contribute to the draft resistance of the rope.

In the document FR-2783585 It has already been proposed to use a polyamide sheath between the core and the outer strands in order, inter alia, to form a layer which distributes the pressures exerted by the strands radially on the core enclosed by them. But the effect of such a sheath is limited to the interface between core and strands, and their execution is problematic in rope making.

you also knows ropes, where between the core and the outer strands a layer of plastic, especially polyethylene, is present. In In a first manufacturing step, the polyethylene is extruded Applied to the core so that it completely surrounds him. Of the core wrapped in this way is rewound and stored until use. When stranding, he is then unpacked again and the plastic sheath, which surrounds him, warms up, until it softens and turns the strands in a classic way arranged around the core, but at the stranding point in the soft plastic pressed can be. But such a manufacturing process requires several rewinding and rewinding operations and considerable Quantities of energy to soften the plastic during stranding.

This energy consumption could be through the document FR-2553442 proposed Seilplastifizierungsverfahren be avoided, in which the previously plasticized core with the strands, which are in turn coated with plastic, assembled. The plastic is applied to the striker on the strands so that at the Verseilpunkt the coating and the assembly take place simultaneously. However, such a rope manufacturing process also requires multiple rewinding and rewinding operations because the core must be plasticized beforehand to ensure there is a protective layer between the core and strands. Furthermore The plastic is in a viscous state when coating the strands and solidifies after assembly. However, this relatively liquid material may leak during manufacture and cause an imbalance in the thickness of the protective layer between the strands.

In addition, the Bring strands together, whereby the separating plastic layer is reduced or completely disappears.

The The present invention has the production of a composite rope for Subject in which in the spaces between the strands a plastic is present, which at least partially fills these spaces, wherein The resulting rope is particularly suitable as a pull or hoist rope, i. generally for all applications where the rope is operating on a drum etc. successively and can be unwound again.

she Fulfills in particular the purpose, the life of such a rope u.a. by reducing the signs of wear to extend through bulge of the strands. In addition, it should be a cost-effective production without major changes allow for the existing stranding devices. In one operation should also have a plastic layer between the core and strands and between the strands are applied.

in view of For this purpose, the invention describes a method for Making a dynamic rope with a multitude of around one Core twisted strands, with the space between the strands and / or between the core and the strands, at least in part, with a polymeric material filled out are; In the method, rope is made by arranging a plurality snail-shaped rolled up Strands formed around a running core, characterized that one while the effluent is a polymerizable compound on the core and / or the strands at one in front of the cable manufacturing point in the flow direction deposited the core coating site, wherein the compound consists of a prepolymer and a polymerization accelerator and the composition of the compound as well as the removal of the coating point are set so that the strands be wound around the core when the polymerization of the deposited Compound has progressed so far that the resulting polymer yourself in such a tough-elastic Condition is that a thick, but still sufficient flowing Coating layer forms into the interstices between core and strands as well as between the strands, and that the polymerization only completed when the rope is formed and around the take-up spool is wound.

One An essential advantage of the invention is that the installation of the polymer material in the rope structure no additional operations requires, as it occurs simultaneously with the stranding, which the process is particularly cost-effective.

at a first embodiment For example, the polymerizable compound is only deposited on the core (from an injection head that encloses the core).

at In another arrangement, the polymerizable compound becomes simultaneously applied to the core and the strands and any leftovers on the rope surface after stranding behind the finishing head, and before The rope is wound on the spool, removed. In this arrangement will be all spaces completely filled between the core and the strands.

Preferably If the polymeric material is also polyurethane, whose Processing in the rope production particularly favorable for the penetration between the Stranding is as described below. Besides that is Polyurethane inexpensive and hardly affects the price of the finished Rope out.

The polymerizable compound takes place shortly before coating Mixing of an isocyanate-containing prepolymer with a polymerization accelerator in predetermined quantities.

The Properties of the compounds of the mixture used for the coating and the processing conditions must be such that: the deposited compound under the rope manufacturing conditions and in particular the temperature and flow rate conditions Immediately after the coating is sufficiently viscous to adhere to the core to stay and until the stranding point a knetähnliche, Semi-solid coating layer to form the mold for the inserted Strands can be formed.

By its adhesion to the steel wires and Litz, which makes up the rope can, by plastic flow under Influence of the resulting in the winding of the outer strands on the core Press the vacancies between the said strands or the Core filled without the polymer material being polymerized emerges from the rope and attaches itself to the parts of the stranding machine such as. guide rollers or similar Parts that are in contact with the finished rope, fixed.

Afterwards the polymerisation has to be finished, as soon as the rope is finished, eg if it is already wound around the take-up spool of the stranding machine or is at least geometrically so stable that the state of polymerization named after the so-called brittle hardening phase does not occur until the outer strands cease to contact one another and against the core in the rope being made can move.

• – eine erste Polymerisierungsphase darstellt, die die Mischung in den o.g. dickflüssigen Zustand versetzt, wobei diese erste Phase kurz bzw. sehr kurz sein muss, damit das Polymer am Kern haften bleibt, sobald es dort abgelagert wird, und
• – eine zweite Phase, bei der die Polymerisierung fortgesetzt wird und das Polymer so lange wie möglich dickflüssig bleibt, bevor es die so genannte Phase der spröden Erhärtung erreicht, selbstverständlich unter Berücksichtigung der Ablaufgeschwindigkeit des Seiles während seiner Herstellung, um den Verseilungsvorgang beenden und die relative Position der Litzen und des Kerns einfrieren zu können, wobei die Litzen in das Polymermaterial eingedrückt werden, ohne dass das fertige Polymer reißt.

The compounds of the mixture used must be determined so that the kinematics of the polymerization reaction:

• Represents a first polymerization phase, which puts the mixture in the above-mentioned viscous state, said first phase must be short or very short, so that the polymer adheres to the core, as soon as it is deposited there, and
• A second phase in which the polymerization is continued and the polymer remains viscous as long as possible before it reaches the so-called brittle hardening phase, of course, taking into account the flow rate of the rope during its manufacture, to end the stranding operation and the relative flow Freeze position of the strands and the core, wherein the strands are pressed into the polymer material without the finished polymer breaks.

The Polyurethane has in view of the o.g. Restrictions and Targets as proved particularly suitable. So it practically fills the entire The space between the core and the strands is made by firstly the area of the Kerns encloses as closely as possible and even between the steel wires or strands from which, if necessary, the outer layer of the core, and secondly between any two adjacent outer strands flows to the point where the strands are closest to each other, i. along the line, on which the outer strands while the insert permanently or occasionally in contact with each other advised.

in the finished rope has every strand of it from the polyurethane that polymerized on contact by being a sort of receiving channel forms exactly the outer dimensions and forms the strand corresponds to certain place. This will be the Risk that touching strands or strands and core touch or rub against each other, severely restricted.

In addition, will the strands not only held in their respective gutter as explained above, but each steel wire is due to the inclination of the steel wires in relation to longitudinal direction the strands on similar Way on the outer surface of the Litz held in his own little gutter, although smaller as the for the strand is, but especially in relation to the longitudinal direction the groove of the strands diagonally runs. This relative gradient provides for this, that the strands in their respective gutters are not lengthwise can slip out.

So Overall, not only the strands together or in relation to Core at right angles to the longitudinal direction held the rope, but also with each other in said longitudinal direction. This is a relative slipping out under the strands in the longitudinal direction virtually impossible, which avoids friction and the wear of steel wires, from which the rope is made, considerably limited becomes. About that In addition, the relative hold of the strands with each other in the longitudinal direction for the Distribution of operating loads, which can be more homogeneous because the Strands no longer slip off each other.

at the ropes of earlier Can make the relative creeping movements of the strands together in interaction with unevenly distributed loads produce overlengths on certain strands, that can go so far that the rope bulges at a certain point, because the overlong Wire a loop-shaped Forming bulge, also called "birdcage" will that for the resistance and the resistance of the rope is considerable. By slipping out the strands foiled out of their grooves formed in polyurethane, it allows the invention to avoid these problems by taking any approach counteracts a relative displacement of the strands.

The for the dynamic winding and unwinding on drums or pulleys necessary flexibility of the rope, however, thanks to the toughness capabilities and the high elasticity extensibility the polyurethane preserves, causing the rope to normal bending during operation and even heavy pull movements can follow without having to tear or otherwise as damaged to become. Accordingly, the smaller slip movements that become in the bending of the rope inevitably between adjacent Strands or steel wires arise, effortlessly through the elasticity of the polyurethane balanced without this at the interfaces between the strands or steel wires is constricted.

• – einen Behälter für das Vorpolymer,
• – einen Behälter für den Polymerisierungsbeschleuniger
• – und einen Einspritzkopf mit einer an die Behälter angeschlossenen Mischkammer,

wobei die Beschichtungsmittel so betätigt werden, dass auf dem Kern und/oder den Litzen während des Ablaufes eine dickflüssige Schicht der bei der Mischung entstandenen Verbindung, deren Polymerisierung bereits eingesetzt hat, abgelagert wird.The invention further relates to a stranding apparatus provided with means for draining the core of a rope and a stranding head to helically arrange a plurality of strands around the core, and also with coating agents to form a polymerizable compound on the core and / or. or the strands, wherein the device is characterized in that the coating means are in front of the stranding head with respect to the direction of flow of the core and include the following elements:

• A container for the prepolymer,
• - A container for the polymerization accelerator
• And an injection head with a mixing chamber connected to the containers,

wherein the coating agents are actuated to deposit on the core and / or the strands during operation a viscous layer of the compound formed in the mixture whose polymerization has already begun.

at In a particular arrangement, the coating compositions are with a Injection head provided, which encloses the core and is operated so that the viscous Layer is deposited only on the core.

The Invention also has a rope to the subject, after the above-described Process is made and a variety of twisted around a core Litz wire involves taking the space between core and strands as well between the steel wires filled with a polyurethane-based polymer material, characterized in that the material is between any two, adjacent outer strands spreads to the point where the strands are closest to each other issue.

Further Features and advantages are apparent from the description, as an exemplary embodiment is made of a rope, that of the invention and its stranding device and with reference to the accompanying drawings, at them:

1 the cross section of a rope according to the invention is;

2 a schematic representation of the stranding device is.

This in 1 rope shown in cross-section 9 consists of a core 1 which may be, for example, a metal core, that of several strands 5 is formed, in this case 7 (1 + 6), with each strand of seventeen wires 6 made of twisted steel, which enclose a central core in two layers (1 + 8 + 8). However, the nature and composition of the core are not limited to the invention. The core could also consist of composite strands.

The core 1 whose boundaries through the circle 10 symbolized by a single layer of strands 2 (here eight) enclosed, each of thirty-one steel wires 7 is formed and formed in three layers (1 + 6 + 12 + 12). The strands 2 are spiral around a kind of polyurethane jacket 3 arranged surrounding the core, wherein about half embedded in this coating. It should be noted that between the strands or the steel wires of which they are made, and the polyurethane no adhesion or special liability is sought and that the strands in the shell essentially by the geometric interaction between the surface shapes of the strands and the above corresponding channel shapes are held in the polyurethane composition. An additional advantage is that, precisely because no such adhesion is sought, no special preparation, cleaning, degreasing, etc. of the core or strands needs to be done.

This rope is made in a stranding device, as in 2 you can see. The device includes means to the core 1 and to let the resulting rope run in the direction of arrow F, said means unwinding reels 11 for unwinding the strands 5 included that from the core 1 and a take-up spool 12 for winding up the finished rope 9 consist.

A stranding head 13 known type ensures that the strands 2 from the unwind bobbins that are in 14 are shown schematically, helically around the core 1 be wrapped.

On the same track as the core is in front of the stranding head 13 at a distance of eg twenty centimeters an injection head 15 arranged, which in transit a polymerizable compound 3 deposited on the core. This polyurethane-based compound is created in the injection head 15 by mixing an isocyanate-containing polymer and a polymerization accelerator. There are also other products with similar properties in question.

To For this purpose, the injection head is equipped with a mixing chamber, which are connected to two containers one of which contains the prepolymer and the other the polymerization accelerator. At the exit the container are means for the flow control provided. It is necessary that the mixing ratio of the individual ingredients to adjust so that the required consistency of the forming polymer is achieved in the cable assembly becomes.

So are good results with the compounds given above scored when the mass ratio Compounds that converge in the injection head, 20 grams Polymerization accelerator and 100 grams of prepolymers is.

The polyurethane 3 is applied to the core in a viscous state. If too much Polyu Rethan is applied, the excess amount is removed after exiting the stranding head with a suitable means. This can occur when, due to the composition of the rope between the strands, there remains a relatively large amount of space to be filled, or when the amount of joint applied to the core is set to be above the line on which the strands are closest lie together, can flow to ensure and control that at least one peninsula 4 Polymer is present between the two steel wires of two adjacent strands, as for example 1 shows.

The Restricted invention not on the rope and on the procedure, which is referred to above only as Examples are described. In particular, number and composition the strands and the composition of the core are changed.

Claims (8)

Method for producing a dynamic rope ( 9 ) with a plurality of around a core ( 1 ) twisted strands ( 2 ), wherein the distances between the strands and / or between the core and the strands are at least partially covered with a polymer material ( 3 A method according to which the cable is formed by the arrangement of a plurality of helically wound strands around a running core, characterized in that during the course of a polymerizable compound ( 3 Deposited on the core and / or the strands at a lying in front of the rope manufacturing point in the direction of the core coating, wherein the compound consists of a prepolymer and a polymerization accelerator and the composition of the compound and the removal of the coating site are set such that the strands are rolled around the core when the polymerisation of the deposited compound has progressed to such an extent that the resulting polymer is in such a viscoplastic state that a thick but still sufficiently flowing coating layer forms into the interstices between the core and strands, as well between the strands, and that the polymerization is completed only when the rope is formed. Process according to Claim 1, characterized in that the polymerisable compound ( 3 ) only on the core ( 1 ) is deposited. A method according to claim 1, characterized in that the polymerizable compound in the coating process simultaneously on the core ( 1 ) and on the strands ( 2 ) is deposited. Method according to claim 1, characterized in that polyurethane is the base material of the polymeric material. Process according to Claim 1, characterized in that the polymerisable compound ( 3 ) is prepared shortly before coating by mixing an isocyanate-containing prepolymer and a polymerization accelerator in a fixed predetermined ratio. Device for producing a cable with means ( 11 . 12 ) to drain a core ( 1 ) of a rope and a stranding head ( 13 ) to a variety of strands ( 2 ) helically around the core, and with coating agents to deposit a polymerizable compound on the core and / or the strands, characterized in that the coating means are in front of the stranding head with respect to the direction of flow of the core and comprise the following elements: a container for the prepolymer, a container for the polymerization accelerator, and an injection head with a mixing chamber connected to the containers, wherein the coating means are actuated such that on the core and / or the strands during the course of a thick layer of the compound formed in the mixture , whose polymerization has already begun, is deposited. Apparatus for producing a rope according to claim 6, characterized in that the coating means an injection head which surrounds the core and is actuated so that the viscous layer is deposited on the core. Rope with a variety of around a core ( 1 ) stranded strands ( 2 ), wherein the distances between the core and the strands with a polyurethane-based polymer material ( 3 ), characterized in that the material spreads between any two adjacent outer strands to where the strands are closest to each other.