DE102015017157A1 - High strength fiber rope for hoists such as cranes - Google Patents

Abstract

The present invention relates to a high strength fiber rope for hoists such as cranes, comprising a rope core comprising high strength plastic fibers and a wear indicating sheath surrounding the rope core. According to the invention, the sheathing has at least one sheath layer in which synthetic fibers of different abrasion and / or tensile strength and / or flexural strength are intertwined with one another.

Description

The present invention relates to a high strength fiber rope for hoists such as cranes, comprising a rope core comprising high strength plastic fibers and a wear indicating sheath surrounding the rope core.

For quite some time in lifting technology, and in particular in cranes, attempts have been made to replace the usual heavy steel cables with high-strength fiber ropes made of high-strength synthetic fibers, such as. Aramid fibers (HMPA), aramid / carbon fiber blends, high modulus polyethylene fibers (HMPE), or poly (p-phenylene-2,6-benzobisoxazole) fibers (PBO), or at least having such fibers. By weight savings compared to steel ropes of up to 80% with approximately the same breaking strength, the load or the permissible lifting load can be increased, since the self-weight of the rope to be considered for the load is significantly lower. Especially in cranes with high lifting height, or in jibs or Mastverstellwerken with pulleys high shear rate considerable rope lengths and thus also a corresponding rope weight come about, so that the possible high-strength fiber ropes weight reduction is very beneficial. In addition to the weight advantage of the fiber rope itself is added that the use of fiber ropes also allows weight savings in other components. For example, the load hook can be carried out more easily because the rope tension of a fiber rope less load hook weight is necessary. On the other hand, the good flexibility of synthetic fiber ropes allows smaller bending radii and thus smaller sheaves or pulleys on the crane, which leads to a further reduction in weight, especially in the area of crane jibs, so that a considerable load moment increase can be achieved with large crane discharges.

In addition to the weight advantages mentioned, rope drives with synthetic fiber ropes are characterized by a considerably longer service life, easy handling and good flexibility, as well as the no longer necessary rope lubrication. Overall, this allows greater device availability can be achieved.

One difficulty with such high strength fiber ropes, however, is to accurately and reliably predict their discardability. High-strength fiber ropes are like steel ropes wearing parts that must be replaced if their condition has deteriorated so far that the necessary safety is no longer given further operation. This condition is commonly referred to as Ablegereife.

In conventional steel ropes, the Ablegereife is determined in a rather simple manner by visual inspection of the condition of the rope, the procedure in the test and the extent of testing in the Standard ISO 4309 is given. Essentially, this is based on the number of wire breaks over a certain measuring length of the rope, a reduction of the rope diameter and strand breaks. However, this measurement method is not possible to detect the Ablegereife high-strength fiber ropes, since the synthetic fibers used do not behave as wire strands. In particular, it comes with high-strength fiber ropes often to a sudden failure or the onset of Ablegereife without gradually recognizable previous damage, since unlike steel ropes often not single fibers gradually tear and splice, but often fail several fiber strands simultaneously.

From the Scriptures DE 20 2009 014 031 U1 is a high-strength fiber rope made of synthetic fibers is known in which a rope core is provided with a sheath that is colored differently than the rope core and in turn has different coat layers of different colors. By this different colored coloring it should be easier to see if by abrasion of an outer layer, a different colored, underlying layer or even the cable core comes to light. In practice, however, this inherently useful color indicator function suffers from the fact that due to the properties of high-strength synthetic fibers, the casing tends to fail quite suddenly, so that it is again difficult to be able to determine or predict the drop-off condition of the rope in good time.

The present invention is therefore an object of the invention to provide an improved high-strength fiber rope, which avoids the disadvantages of the prior art and the latter advantageously further. In particular, a simple, yet reliable and accurate determination of the Ablegereife and thus the longest possible use time should be possible without compromising the safety of the fiber rope.

The above object is achieved by a high-strength fiber rope according to claim 1 and a hoist with such a high-strength fiber rope according to claim 11. Preferred embodiments of the invention are the subject of the dependent claims.

It is therefore proposed to form the sheathing of the rope core in such a way that damage to the sheathing does not occur at the same time everywhere, but partially and gradually, by means of which gradually different levels of damage and wear conditions can be determined. The Sheathing has a fiber structure of various types of synthetic fibers, which have different wear resistance and thus not all at the same time show damage even with even uniform exposure to wear-promoting influences, but gradually wear out. According to the invention, the sheathing has at least one sheath layer in which synthetic fibers of different abrasion and / or tensile strength and / or flexural strength are intertwined with one another. The different abrasion and / or tensile strengths and / or flexural strength of the plastic fibers used in a cladding layer ensures that damage to the cladding layer only partially and gradually occur, so based on the gradually increasing damage sites different states of wear of the rope and the associated, still remaining distance to Ablegereife are gradually determined and quantified.

Advantageously, the plastic fibers interwoven in a cladding layer can be made of different materials. For example, in a cladding layer, HMPE fibers and polyester fibers may be intertwined. Alternatively or additionally, other of the aforementioned fibers such as PBO fibers and / or aramid-carbon fiber blended fibers may be intertwined with each other or interlaced with the aforementioned sheath layer.

As an alternative or in addition to synthetic fibers of different abrasion and / or tensile strength and / or different materials in a cladding layer, according to a further aspect of the present invention, the cladding of the fiber rope may also have a plurality of cladding layers, wherein the fibers are resistant to abrasion and / or tensile strength and / or or change bending resistance from layer to layer. In particular, a plurality of cladding layers may be provided which differ from one another with respect to their fiber structure and the abrasion and / or tensile strengths and / or bending resistance of the synthetic fibers used in the cladding layers.

For example, plastic fibers may be provided in a first cladding layer, which differ in terms of their abrasion, bending change and / or tensile strength of all plastic fibers in a second cladding layer. Advantageously, plastic fibers of a certain abrasion and / or tensile strength can also be provided in each cladding layer, which are not provided in any other cladding layer, so that each cladding layer exhibits a characteristic resistance to abrasion and breakage damage, which leads to a different partial damage pattern in each cladding layer. This makes it easy to distinguish more and more in depth damage in a simple way.

The synthetic fibers used in the various lateral surfaces may also consist of different materials, for example, such that in a first cladding layer plastic fibers of a material are provided, which are not present in a second cladding layer. Alternatively or additionally, plastic fibers made of a material that is missing in the first cladding layer can conversely also be provided in the second cladding layer.

As an alternative or in addition to fibers different from layer to layer, the cladding layers of the cladding may also have different layer thicknesses and / or different thicknesses of plastic fibers and / or strands may be provided from layer to layer. By using different thick plastic fibers different damage patterns can be achieved from layer to layer. Also, by using different thicknesses of layer, which may increase, for example, from outside to inside, it can be ensured that more and more in depth damage always occur more difficult and initially only minor damage, which are relatively far removed from the Ablegereife initially occur on the outer layer and thus easily recognizable.

The use of synthetic fibers of different fiber thickness and / or different strand thickness can also be useful in a cladding layer in order to achieve partially different damage patterns in a cladding layer.

In order to make it easy to detect the various damages even with only small amounts of damage, the plastic fibers, which have different abrasion, Biegewechsel- and / or tensile strengths and / or consist of different materials, be dyed in different colors. Alternatively or additionally, it is also possible to use different colors from sheath layer to sheath layer or to stain different sheath layers in different colors. As a result, the optical detection of damage to the sheath is much easier, since wear of an outer cladding layer, the underlying cladding layer is visible in a different color.

In particular, the cable core may have a different color than the sheath, in particular a different color than the lowermost or innermost sheath layer of the sheath, so at the latest at a complete wear of the sheath, the other color of the rope core is visible.

The determination of the Ablegereife can be carried out on the basis of reference representations of the rope in different degrees of damage manually by a knowledgeable person such as the crane operator as a visual inspection, which can categorize the damage occurred, record and summarize in writing, then possibly determine the Ablegereife or an expert consulted.

The invention will be explained in more detail below with reference to a preferred embodiment and associated drawings. In the drawings show:

1 to 5 in each case a side view of a high-strength fiber rope with a braided sheath, wherein the sheath wear occurring at the sheathing is shown in different degrees of damage and gradually the rope core comes to light,

6 to 9 in each case a plan view of a section of a high-strength fiber rope with a casing according to a further embodiment of the invention, wherein here are shown as damage to the casing cuts on the rope in different states of expression, and

10 to 13 in each case a section of a high-strength fiber rope with a casing according to a further embodiment of the invention, wherein damage to the casing is represented in the form of a pinch of the rope in different states of expression.

Such as the 4 and 5 show, the high-strength fiber rope comprises a rope core 11 that made strands 4 braided or beaten, which in turn consist of high-strength synthetic fibers or at least comprise such high-strength synthetic fibers, for example HPMA fibers, HMPE fibers or other of the aforementioned fiber types, said cable core 11 may consist of fibers of a fiber type or fibers of different fiber types.

The jacket 2 surrounds the said rope core 11 and may sit directly on said cable core or, if necessary, be spaced therefrom by an intermediate layer. The said sheath 2 in particular, the outer jacket of the rope 1 form. The rope core 11 can be the total specified load-bearing capacity of the rope 1 take. The jacket 2 is only supportive, especially as protection for the rope core 11 and as a wear indicator.

The said sheath 2 may consist of a single cladding layer or may comprise a plurality of cladding layers, which are arranged one above the other.

As the figures show, said sheath comprises 2 strands 3 that are together to the sheathing 2 braided and may each consist of high-strength synthetic fibers or at least may have such high-strength synthetic fibers.

In particular, the strands mentioned 3 the sheath 2 be formed in the manner described in detail above from different synthetic fibers of different abrasion and / or tensile strength and / or different materials. As the figures show, these strands are 3 advantageously dyed in different colors.

In the 1 to 5 is a sheath wear of the sheath 2 represented, for example, by the cable drive may be due, in particular the deflection of the rope pulley, the bending change in the rope course, the rope friction on the drum during winding and the stress in a multi-layer winding on the drum, in which the cable sections of an upper layer threaten to cut between the rope sections of a lower layer.

1 shows the rope 1 with sheathing 2 and the strands 3 the sheath in different colors. Degree of damage shown about 5%.

2 shows the rope 1 with sheathing 2 however with visible wear of the individual strands 3 of the coat. Degree of damage shown about 25%.

3 shows the rope 1 whose sheathing is worn over a section of about 90 ° and the strands 4 of the carrying rope become visible. Degree of damage shown about 50%.

4 shows the rope 1 , whose sheath has an advanced state of wear in a section of about 180 ° and the strands 4 of the load-bearing rope are clearly visible in this section. Degree of damage shown about 75%.

5 shows the rope 1 , whose sheath has a highly advanced state of wear over the entire circumference of the rope (360 °). The coat is worn and shifted and the strands 4 of the load-bearing rope are fully visible in this section. Degree of damage shown 100%.

The 6 to 9 show a damage of the rope in the form of incisions, which lead to a gradually spreading degree of damage.

6 shows the rope 1 with sheathing 2 and the strands 3 the sheath in different colors. Degree of damage shown 0%.

7 shows the rope 1 whose casing has a visible slight incision 5 having. Degree of damage shown about 25%.

8th shows the rope 1 , its sheathing and a strand of rope carrying a visible incision 6 exhibit. Degree of damage shown about 50%.

9 shows the rope 1 , whose casing and at least one strand of the supporting rope have a visible average 7 exhibit. Degree of damage shown 100%.

The 10 to 13 Finally, a damage to the high-strength fiber rope in the form of bruising the rope.

10 shows the rope 1 with sheathing 2 and the strands 3 the sheath in different colors. Degree of damage shown 0%.

11 shows the rope 1 with a slight bruise 8th and ovalization of the rope cross-section. Degree of damage shown about 25%.

12 shows the rope 1 with a strong bruise 9 and a strong ovalization of the cable cross-section. Degree of damage shown about 50%.

13 shows the rope 1 with so much bruising 10 in that the jacket is open and the damaged strands of the supporting cable emerge. Degree of damage shown 100%.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 202009014031 U1 [0006]

Cited non-patent literature

• Standard ISO 4309 [0005]

Claims (12)

High strength fiber rope for hoists such as cranes, with a rope core ( 11 ), the high-strength plastic fibers or strands ( 4 ), and one of the cable core ( 11 ) surrounding, wear-indicating sheath ( 2 ), characterized in that the sheath ( 2 ) at least one cladding layer in which plastic fibers of different abrasion and / or tensile strengths and / or Biegewechselstandfertigkeiten intertwined with each other has. High-strength fiber rope according to the preceding claim, wherein the plastic fibers in said at least one cladding layer consist of different materials, preferably comprising HMPE fibers and polyester fibers. High-strength fiber rope according to the preamble of claim 1 or one of the preceding claims, wherein the sheath ( 2 ) has a plurality of cladding layers, which differ from each other in terms of their fiber structure and the abrasion and / or tensile strengths and / or bending resistance of the composite used in the cladding layers of plastic fibers. High-strength fiber rope according to the preceding claim, wherein plastic fibers are provided in a cladding layer which differ with regard to their abrasion and / or tensile strength and / or bending resistance and / or their material from all plastic fibers of at least one further cladding layer. High-strength fiber rope according to the preceding claim, wherein in the said further cladding layer are plastic fibers which differ with respect to their abrasion and / or tensile strength and / or their material from all plastic fibers in the aforementioned one cladding layer. High-strength fiber rope according to one of the preceding claims, wherein the sheath ( 2 ) Has coat layers of different layer thicknesses and / or from layer to layer of different thickness plastic fibers and / or strands. High-strength fiber rope according to one of the preceding claims, wherein the synthetic fibers, which have different abrasion and tensile strengths and / or consist of different materials, are dyed in different colors. High-strength fiber rope according to one of the preceding claims, wherein the cable core ( 11 ) one of the sheath ( 2 ) has different color. High-strength fiber rope according to one of the preceding claims, wherein the sheath ( 2 ) forms a high-density braided protective jacket which at least in the unworn state, the entry of dirt to the cable core ( 11 ) prevented. High-strength fiber rope according to one of the preceding claims, wherein the sheath ( 2 ) of the rope core ( 11 ) the outer sheath of the rope ( 1 ). Hoist, in particular crane such as tower crane, telescopic, harbor or ship crane, with a high-strength fiber rope ( 1 ) formed according to one of the preceding claims. Hoist according to claim 11, wherein the high-strength fiber rope ( 1 ) forms a crane hoist rope or a crane boom guy rope.

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