HU202149B - High-strength flexible steel wire for reinforced structures - Google Patents

Abstract

High strength, flexible cable is made up of several layers, each being laid in a helical form. The cable is of circular cross-section . - The covering stands and their neighbouring layer strands are equal in number and follow the same pattern. A spiral notch is included between covering strands. The strands of the outermost layer at least, have a flattened cross-section.

Description

BACKGROUND OF THE INVENTION The present invention relates to a multilayer, high strength, flexible steel cord which can be used for its reinforced structures, in particular for the manufacture of high pressure fiber reinforced rubber hoses, but also for the manufacture of other reinforced rubber products.

It is known to use high strength steel threads to provide the rubber properties of these products, and especially of the high pressure submersible hoses. The structure of steel strands is usually multilayer, often seven-stranded (1 + 6), twelve-stranded (3 + 9), nineteen-stranded (1 + 6 + 12), and more recently twenty-four-stranded, Warrington.

The requirement for these steel structures is, on the one hand, the high tensile strength in the stress-free condition and the excellent adhesive surface. So far, the structures described above have only partially met these requirements.

For (1 + 6), (3 + 9), and (1 + 6 + 12) fibrous structures, a geometric design results in a loose structure that adversely affects the total tensile strength of the steel structure and, due to the helical design, due to imperfection - internal tensions remain in the wire. These adversely affect the use of the wires. One of the major drawbacks of the wires used so far is the relatively smooth outer surface, which has rather shallow thread grooves.

Therefore, in order to obtain an adequate adhesion value between the steel wire and the rubber, the wires are currently coated with brass, bronze or copper and use a special, well-adhering rubber compound.

Known steel wires are generally made of circular filaments and the wrapping wires are in contact with each other or have a minimal gap between them. This design has the disadvantage that, in reinforced rubber structures, metal-rubber adhesion is formed only along the outer surface of the wrapping wires, and that in the manufacture of reinforced rubber products, the guide rings and combs are subjected to strong abrasion, points in contact with the guide rings and high friction forces occur. Due to the point contact, the surface layer of the wire is also damaged, in the case of galvanized wires the coating is damaged and, according to practical experience, the peeling zinc particles sooner or later block the guide rings. Thus, a smooth, regular circular contour would be advantageous from the point of view of the guiding system, but a more articulated surface would be desirable for the adhesion.

In order to better meet the increasing demands, steel ropes with polygonal cross sections have been made. An example of such a wire rope structure is the 1 247 604 GB PS. Hexagonal steel ropes were generally used in practice. However, such steel wires only slightly improve the adhesive properties of the circular steel wires, due to the fact that the wires at the periphery of the wire are in contact with each other, so that deeper troughs and threads are not possible which are protrusions are used on the outside of the wire to increase the surface. For example, such a strand structure is disclosed in DE 525 129 129. The steel wire described in this patent has a relatively small increase in adhesion, since the projections in question are in contact with each other, and consequently shallow thread grooves are formed on the outside of the wire.

The object of the present invention is to eliminate the drawbacks and shortcomings of known steel ropes.

The object of the present invention is to provide a steel rope which, with sufficient structural stability, has protruding portions on its exterior which create a deep, trench-like groove in helical form, thereby providing good adhesion and shape bond between the rubber and the steel rope. , however, the outer contour is smooth so that it can be guided in the guides with a minimum of friction without surface damage.

The object of the present invention is achieved by flattening the cross-section of the wrapping wires in its outermost layer and which, when examined in a section perpendicular to the axis of the wire, has an outer radius of curvature R equal to half the diameter D of the wire. the ratio is preferably from 1.05 to 1.5, preferably from 1.1 to 1.3. The wires of the cladding wires and the second-layer wires from the outside (hereinafter referred to as "wires") have the same thread pitch. The number of wires in these two layers is the same. Between the wrapping wires, there is a helical recess into which the rubber penetrates, up to the ply wires, to form a metal-to-rubber bond on a larger surface and even to form a bond. Compared to conventional wires, the adhesive strength per unit of wire per wire can be increased by 40%.

The outer surface of the wire thus formed, except for the spirally running recesses, has a cylindrical shape, so that when used, it runs smoothly in the guide rings and the guide combs, and does not "grate" them like traditional circular filaments.

In a preferred embodiment of the steel wire according to the invention, the wire consists of core wire and two layers of wire having the same pitch; the tensile strength of the core wire is higher than that of the surrounding wires. Namely, when the core is loaded, the specific elongation of the core wire, the strand wire and the wrapping wire is approximately proportional to each other.

I: (cos ² a8-msin ^z a8): (cos αι-msin ai), where a8 is the angle of the center line of the wires and ai is the angle of the center line of the wires and m is the Poisson coefficient of the steel (m = 0.3) ). In the case of the wire according to the invention, since the thread pitch of the inner and outer wire layers is the same, the specific elongation of the individual wire layers and the tension rising therein are increased in the following order.

-2HU 202149Β

It is particularly advantageous to increase the specific tensile strength of the wires in the same order, approximately in the (cos αι-ursin ai): (cos as-ujsin as): 1 arane. 5

The wires according to the invention are also distinguished by their high flexibility and hardness.

The steel wire according to the invention and the process for making it will be described in more detail in the exemplary embodiments illustrated in the accompanying drawings.

In the drawing it is

-6. Figures 3 to 5 are cross-sectional views of steel wires of various structures;

Figure 7 is a schematic side elevational view of an apparatus 15 for producing steel ropes according to the invention.

In the embodiment of Figure 1, the wire consists of nine wires. The core wire 10, which is thinner than the other wires, is surrounded by four layer wires 8 surrounded by 20 new four wrapping wires 1.

Fig. 2 illustrates a solution in which there are five layer wires 8 surrounding the core wire 10 surrounded by another five wrapping wires 1.

In the exemplary steel wire shown in Fig. 3, six core wires 8 surround the core wire 10, surrounded by six wrapping wires 1.

The advantage of the inventive wires is that the flexibility and tensile strength of a single ten wire (1 + 6 + 6) wire construction is equivalent to that of a traditional twelve fiber (1 + 6 + 12) wire, but is approximately 10% lower in river weight. .

The steel wire shown in Fig. 4 in the core wire layer 10 has seven layer wires 35, also surrounded by a wrapping wire 1.

In the embodiment of Figure 5, the core of the wire is provided with 12 4-strand twist. The number of wires 1 of the outermost layer 8 is the same as the number of layers 8 (second from the outside). 40

In the embodiment of Figure 6, the number of wrapping wires 1 is twelve, the number of ply wires 8 is small, and the twist of the inner (1 + 6) structure is regarded as core 12.

Showing 1-6. 1 to 4, a trench groove-like, relatively deep groove is formed between the cladding wires, while the entire core is circular in cross-section.

Figure 7 is a line diagram of a twisting device. This sketch illustrates a side view of the soda ash 50. In the apparatus, the rolling head 2 comprises, among other things, the inner conductor 9 and the outer conductor 11. In the exemplary apparatus, the inner conductor 9 provides stranding of the core wire 10 and the layer wires 8, while the outer conductor all provides the wrapping wires 1 55. The device includes a special tool 3 and a special tool 4. Immediately after the strand wires are twisted, the target tool 3 provides deformation, which is essentially cold forming. The intermediate wire 6 thus formed is used to twist the wrapping wires 1 with the help of an outer conductor all the way through the rolling head 2. Thereafter, the twist is forced to pass through the target tool 4 due to the shape formed by the hinge 5. The special tool 4 also performs the deformation by cold forming and essentially produces the finished wire 7.

The wires according to the invention do not need to be deformed twice, but at least once, after the wrapping wires have been twisted, this operation must be carried out.

It is evident from the exemplary solution that the wires are twisted and deformed in a single device.

On the basis of practical results, it has been found that deformation cold forming is optimal when it results in a 26% reduction in the diameter of the steel wire.

Cold forming enhances the advantageous properties of the steel wire, since it results in a uniform tension of the wires in the wire, which ultimately means more load bearing capacity than reinforced rubber products.

Claims (3)

A high-strength, flexible steel wire, in particular for the rubber industry, the wires of which are arranged in several layers, threaded inside each layer, characterized in that the steel wire has a cross-sectional envelope in which the wires (1) and adjacent layers 8 ), the twisting direction and the pitch of the thread are the same, there is a groove spirally located between each wrapping wire (1) and at least the outermost layer has a flat cross-section. Steel wire according to Claim 1, characterized in that it comprises wrapping wires (1), ply wires (8) and core wire (10) and the specific tensile strength of the core wire (10) is higher than that of the wrapping wire (1). Steel wire according to Claim 2, characterized in that the specific tensile strength of the wrapping wires (1), the ply wires (8) and the core wire (10) is approximately the same relative to each other as (cos ^Z a8). -msin ^Z a8): 1 where ai is the angle of the wrapping wire (1) with the wire axis, αδ is the angle of the wire (8) with the axis of the wire, and vj is the Poisson factor of the steel.