HK1141756B - Method for the production of a wire strip comprising a plurality of wires arranged parallel to each other and wire strip produced according to said method - Google Patents

Description

Method for producing a wire strip consisting of a plurality of core wires arranged parallel to one another and wire strip produced according to said method

The invention relates to a method for producing a cable belt consisting of a plurality of core wires arranged parallel to one another, wherein, to form the core wires, a steel plate is first slotted either on one side or on both sides, thereby producing core wires which are still connected by a bridge (Steg). The invention also relates to a metallic wire strip produced according to said method.

Such a ribbon is required, for example, in the production of staples (Heftklammer), for which various methods are known from the prior art. DE-PS 287820, for example, describes the following process: the prefabricated wires are bonded together or brazed or welded together point by point, so that a metal strip is produced which consists of a desired number of wires which can subsequently be separated from one another.

It is known from DE-PS 540837 to machine the metal strip by a stamping process, so that the individual parts can be obtained from the metal strip by subsequently severing the remaining bridges.

The object of the invention is to provide a production method which makes it possible to produce a wire band of the type mentioned at the outset which, on the one hand, does not require the use of additional joining techniques, but at the same time, after subsequent separation, has as far as possible burr-free core wires in accordance with the respective requirements of the end product.

According to the invention, this object is achieved in that, for the subsequent deformation of the webs into thin, easily separable separating webs which, when separated, form smooth, burr-free separating surfaces, the wire strip is subjected to a bending process in which each web is bent around its longitudinal axis a plurality of times, as a result of which cracks are formed in the region of the web via fatigue fractures and the separating webs are produced.

The advantages achieved by the invention consist primarily in that, by means of the metallurgical effect of the fatigue fracture, a largely smooth burr-free parting surface is formed without the core wire formed thereby having to be completely separated. As a result, the separation can be effected later without great effort, for example in a stapler, or before subsequent processing, it is necessary for the core wires to be completely separated from one another and for the tensioned, burr-free, smooth separating surfaces to be visible. This method has the following advantages in particular: no subsequent processing of the separating surfaces is required, as is the case with other production methods, such as shearing or stamping.

The minimum depth of the groove is selected as follows: reliable fatigue fracture cracks are generated at the bottom of the groove through bending treatment.

Typically, the maximum depth of the V-groove is selected as follows: in the region of the bridge, the deformability of the raw material is almost exhausted. The thickness of the bridges left after the grooving can in particular lie in the range between 20% and 95% of the strip thickness, wherein the thickness of the bridges is determined together primarily by the ductility of the material.

Furthermore, according to the invention, it has been shown to be advantageous that the bending process comprises: the bending deformation is repeated on one side, relative to the plane of the wire band, until a fatigue fracture is produced in the region of the bridge. Alternatively, the bending process may also include: the bending deformation is repeated on both sides, based on the plane of the wire band, until fatigue fractures occur in the bridge region.

The bending process can be carried out here as follows: the bridge parts are bent and deformed several times at the same angle. However, depending on the use and material properties, it may alternatively be advantageous to deform the bridge by bending several times in each case with increasing or decreasing angular size.

The bridge member is preferably bent a plurality of times at an angle less than the slot angle.

In order to separate the individual wires from one another completely or only in regions, the separating bridges can be broken by deflecting the side-by-side wires slightly toward one another transversely to the belt. It is to be taken into account here that the remaining bridge regions and the resulting through-regions are to meet the requirements of the intermediate product or can be processed to the end product. For this purpose, markings are made on the strand which indicate the entire length of the end product and which can be noticed when the strand is being processed. However, the following solutions may also exist: after the bending process, the through-regions are not produced first, but the remaining bridges and through-regions are designed with suitable devices directly according to the requirements of the respective product before the subsequent processing device.

Finally, when using this method, it is recommended to use a metal strip-shaped semifinished product as the preform.

From the device point of view, the object of the invention is achieved with a metal wire strand consisting of a plurality of core wires arranged parallel to one another and connected to one another by webs, which is used as a preform, is formed as a strip-shaped semifinished product which is grooved on one or both sides for the formation of the core wires, wherein the webs are deformed by multiple bending deformations to thin, easily separable separating webs which form smooth, burr-free separating surfaces during the separation and have fatigue fractures.

By the bending process, a fatigue fracture based on the bridge is generated, thereby weakening the bridge. The separation plane created by fatigue fracture is relatively smooth and burr-free. The remaining separating bridges can be thin, since they are in an intermediate stage of the bending process, thus making it possible to separate the cords from each other.

The ribbon has the following advantages: when separating the individual wires, smooth and burr-free separating surfaces are formed by the existing fatigue fractures, wherein the force required for the separation is at the same time kept within reasonable limits as required by the respective application.

According to the invention, as metal material, it is recommended to use raw materials based on special steel, iron, copper or aluminum. Furthermore, as metal material, coated metal strips, in particular galvanized or copper-coated iron strips, can also be used. As the metal material, in particular, the following raw materials can be specified: with these materials, particularly high strength values can be achieved for the respective material groups by rolling.

The opening angle of the grooves in the tape is preferably between 30 ° and 120 °.

The thickness of the bridges is preferably in the range between 20% and 95% of the strip thickness and depends on the properties of the metal material, in particular its ductility.

According to the invention, it is furthermore provided that the bridge, by means of a bending process transverse to the pre-grooved strip, forms cracks in the surface region of the very strong groove base via fatigue fractures having a velvet-like surface and reducing burrs that form during later separation. In order to keep the separating force low, it can also be provided that: the separation bridge has a through portion which is first locally generated in the longitudinal direction.

According to the invention, it has furthermore been found to be advantageous for the coated metal strip to have a layer of relatively uniform thickness applied to the top and bottom sides of the core, whereas the layer thickness of the narrow sides of the core in the region of the groove edges via the grooves decreases towards the run-through region and the run-through region itself is not coated.

Generally, the cords have the same width as each other in the cord band; however, according to the invention, the following solutions are also possible: the cords have different widths in the ribbon.

Finally, according to the invention, there is also the following solution: the essentially rectangular core wire, which is initially specified by the preform, is deformed outside the groove region according to the intended use.

The invention is explained in detail below with the aid of embodiments shown in the drawings; the figures show that:

FIG. 1 is a cross-sectional view, only partially shown, of a prefabricated material provided for the manufacture of a line strip, in which pre-bonding has been carried out;

fig. 2 shows a prefabricated material, which is provided for producing a wire strand, in a bending deformation state and is subjected to a bending process (Walkprozess);

fig. 3 shows a device for locally severing (durchtrennnung) a ribbon separator bridge;

FIG. 4 is a side view of the object according to FIG. 3;

FIG. 5 is a partial cross-sectional view of the wire strap in the area of the slot;

FIG. 6 is a cross-sectional view of a ribbon bent in a U-shape for use as a staple and for a different design example;

fig. 7 is a cross-sectional view of a single coated core wire.

The device shown in the figure is used for producing a wire strand 1 consisting of a plurality of core wires 2 arranged parallel to one another.

In this case, to form the core 2, the steel plate is first slotted in a manner not shown in detail in the figures, either on one side or on both sides, so that a core 2 is produced which is still connected by the bridges 3, as shown in fig. 1.

In order to subsequently deform the bridges 3 into thin, easily separable separating bridges, which, when separated, form smooth, burr-free separating surfaces, the wire strip is bent according to fig. 2, wherein each bridge is bent several times about its longitudinal axis by means of the upper and lower rollers 5, 6. Cracks are thereby formed in the region of the webs 3 which have passed through fatigue fractures (Dauerbruch), thereby producing a separating web which can be easily separated later.

As shown, the slotted slot is preferably a V-shaped slot 4, wherein the slot angle W may be between 30 ° and 120 °. Also as shown, the groove angle W is preferably about 60 ° here.

The thickness of the bridge 3 can be in the range of approximately 20% to 95% of the thickness of the strip 1, wherein this is dependent in particular on the ductility of the material. Generally, the groove depth is chosen such that the deformability of the material is almost exhausted in the region of the bridge 3.

The bending process includes: with reference to the plane of the line strap 1, a plurality of bending deformations are made, either on one side or on both sides, as shown in fig. 2. For this purpose, a plurality of roller devices each composed of an upper roller 5 and a lower roller 6 are provided in the front-rear direction as necessary along the extending direction of the tape 1.

The bending angle B of the bridge 3 in the case of multiple bending deformations can be of the same size; but may be increased or decreased. The choice may also be made according to the characteristics of the belt material used. Here, the bending angle of the bridge 3 is usually smaller than the groove angle W in the multiple bending deformation. As prefabricated material, strip-shaped metal semi-finished products are used here, for which metallic materials based on special steel, iron, copper or aluminum are particularly suitable. In particular, coated metal strips, in particular galvanized or copper-coated iron strips, can also be used here. It has proven particularly advantageous here to provide, as metal material, the following starting materials: with these materials, particularly high strength values can be achieved for the respective material groups by rolling.

In view of the fact that the individual cords 2 can be separated later, the separating bridge 3 can have a through-section 7 which has been produced locally in the longitudinal direction. To achieve this, a roller arrangement according to fig. 3 and 4 can be provided, in which the side-by-side wires 2 are deflected only slightly towards one another, so that the separating bridges are broken. By means of a suitable design of the separating roller 8 according to fig. 3 and 4, the location of the separating zone and of the remaining part 9 of the separating bridge can be adapted to the respective requirements of, for example, a staple strip. This can be seen in more detail in fig. 4.

Fig. 5 shows a possible processing result of the bridge 3 after the bending process and the above-described process of local separation. Here, the region a indicates two partial separation regions generated by the bending process. In contrast, the region c represents the region where the remaining bridge has been partially severed and-shown in hatched lines-leaving the remaining portion 9 of the detached bridge.

To this end, fig. 6 shows an example of a staple strip, wherein the recommended design is: the remaining bridges are left behind and are partially severed.

In the case of a coated metal strip, the top and bottom surfaces of the core wire 2 can be coated with a layer 10 of relatively uniform thickness, whereas the layer thickness of the narrow sides of the core wire 2 in the region of the groove 4 decreases towards the run-through region, which is not coated per se. This is illustrated in fig. 7 by means of a single core example.

In addition, the following selection of the device can likewise be made in a manner which is likewise not illustrated in the figures: the core wires 2 have different widths in the wire band 1. In contrast, in the wire belt 1, the core wire width is generally uniform.

Finally, there are the following solutions, which are also not shown in detail in the figures: the essentially rectangular core wire 2, which is initially specified by the preform, is deformed outside the groove region according to the intended use.

Claims (22)

1. A method for producing a wire strand (1) consisting of a plurality of core wires (2) arranged parallel to one another, wherein, for forming the core wires (2), a metal strip-shaped semifinished product is first pre-grooved as a prefabricated material, either on one or both sides, thereby producing core wires (2) which are still connected by webs (3), characterized in that, for the purpose of subsequently deforming the webs (3) into thin, easily separable separating webs which, when separated, form smooth, burr-free separating surfaces, the wire strand (1) is subjected to a bending process, wherein each web (3) is bent several times about its longitudinal axis, so that cracks are formed in the region of the webs (3) which have undergone fatigue fracture, thereby producing the separating webs.

2. Method according to claim 1, characterized in that said pre-grooving is performed by means of a V-groove (4).

3. The method of claim 2, wherein the slot angle W is between 30 ° and 120 °.

4. The method of claim 2, wherein the slot angle W is about 60 °.

5. The method according to any of the claims 1 to 4, characterized in that the thickness of the bridge (3) is 20 to 95% of the thickness of the string ribbon (1).

6. Method according to claim 2, characterized in that the depth of the V-shaped groove (4) is chosen as follows: in the region of the bridge (3), the deformability of the raw material is almost exhausted.

7. The method of claim 1, wherein the bending process comprises: the wire band (1) is bent several times on one side, relative to the plane thereof, until a fatigue fracture occurs in the region of the bridge (3).

8. The method of claim 1, wherein the bending process comprises: bending and deforming the wire band (1) on both sides a plurality of times, based on the plane thereof, until fatigue fractures occur in the region of the bridge (3).

9. Method according to claim 1, characterized in that the bridge (3) is bent several times in each case with the same angular size.

10. Method according to claim 1, characterized in that the bridge (3) is bent a plurality of times with increasing or decreasing angular size, respectively.

11. A method according to claim 3, characterized in that the bridge (3) is bent a plurality of times at an angle smaller than the slot angle W.

12. Method according to claim 1, characterized in that the side-by-side wires (2) are deflected slightly towards each other transversely to the wire band (1), whereby the separation bridges are locally broken.

13. A metallic wire ribbon produced according to any one of the preceding method claims, consisting of a plurality of mutually parallel arranged core wires (2) which are connected to one another by means of webs (3), characterized in that a strip-shaped semifinished product for use as a prefabricated material, which is grooved beforehand either on one side or on both sides in order to form the core wires (2), is deformed by multiple bending deformations into thin, easily separable separating webs which, when separated, form smooth, burr-free separating surfaces and have fatigue fractures.

14. The cable tie according to claim 13, wherein as the metal material, a raw material based on special steel, iron, copper or aluminum is specified.

15. The cable tie according to claim 13, wherein as the metallic material, a coated metallic tape is defined.

16. The tape according to claim 13, wherein as the metal material, the following raw materials are specified: particularly high strength values can be achieved with these raw materials for the respective raw material group by means of rolling.

17. A strip according to claim 13, characterised in that the bridges (3) form cracks in the surface area of the very strong groove base through fatigue fractures with a velvet-like surface and reduced burrs that form during later separation by bending processes transverse to the pre-grooved strip (1).

18. Line strap according to claim 13, characterized in that the separating bridge has a through-going portion (7) locally produced in its longitudinal direction.

19. A strip according to claim 15, characterised in that, in the case of coated metal strips, the top and bottom surfaces of the core (2) are coated with a layer (10) of relatively uniform thickness, whereas the coating layer thickness of the narrow sides of the core (2) in the region of the slot (4) decreases towards the run-through region, which itself is not coated.

20. A string as claimed in claim 13, characterised in that the core wires (2) have different widths in the string (1).

21. A cable tape according to claim 13, characterized in that the essentially rectangular core wires (2) predetermined first by the prefabricated material are deformed outside the groove region according to the purpose of use.

22. The wire tape according to claim 15, wherein as the metal material, a zinc-plated or copper-plated iron tape is specified.