EP0092696A2 - Reinforcing cord for rubber products - Google Patents

Abstract

Reinforcement rope made of metal wires for elastomeric products, consisting of at least two strands stranded together, each consisting of two or more wires, characterized in that at least one outer strand consists of two or more core wires wound helically by at least one strand loop wire.

Description

The invention relates to a reinforcement rope made of metal wires for elastomeric products.

Reinforcement ropes are usually embedded in layers in the elastomeric products, for example in the manufacture of pneumatic vehicle tires, drive belts or conveyor belts. Here, metal wires are arranged in a single strand with a single wire diameter of usually 0.12 to 0.5 mm, usually in one or two layers. To increase the resilience of these elastomeric products, either several layers of metal wire ropes in single stranding or one or two layers of ropes in multiple stranding are required. This higher load capacity is required, for example, when using the reinforcement ropes in truck pneumatic tires and in the air ceilings of earthmoving machines. Single stranded metal wires, several of which are rewound to a two or multiple rope, are called strands.

The technical terms used here about rope constructions are taken from the book "Stabldrahterzeugzeug", Verlag Stahleisen, 1956, Volume I.

Since the production of elastomeric products with several layers of metal wire ropes with simple stranding is very labor-intensive, reinforcement ropes with multiple stranding, i.e. reinforcement ropes which consist of at least two strands stranded together, each consisting of two or more wires, are preferably used under higher loads.

However, it has been shown that such reinforcing ropes in the elastomeric product corrode undesirably if the surface of the composite material is damaged up to the rope level. As a result, the service life of the composite materials is impaired even with minor damage. Due to the very close position of the individual wires when embedded in the elastomer, this cannot reach the core of the ropes sufficiently. Wire sections for corrosive media therefore remain accessible there. If the individual wires lie parallel to one another, the capillary formed by the wires even promotes the spread of corrosive media in the composite material.

Surprisingly, it has now been found that the tendency for corrosion of a reinforcement rope consisting of several strands in elastomeric products is no greater than that of the metal wire ropes of simple stranding if at least the outer strands are wrapped helically with loop wire.

The object of the invention is therefore to provide a reinforcement rope for elastomeric products, which consist of at least two strands stranded together, each consisting of two or more wires, which, after being embedded in the elastomeric material, has approximately the same or the same behavior against corrosion as the ropes in simple stranding.

According to the invention, this object is achieved by a reinforcement rope of the type mentioned above, which is characterized in that at least one outer strand consists of two or more core wires wound helically by at least one strand wrap wire. It is particularly advantageous if each outer or even each strand consists of two or more core wires wound helically by at least one strand wrap wire.

The metal wires should bond well with the elastomeric material. However, they can also be coated with a second metal, plastic or another material, with a good tendency to bind between the metal wire and the coating material on the one hand and the coating material and elastomeric material on the other hand. Wires made of steel, usually made of carbon steel, are also particularly suitable, but also made of other types of steel, for example made of alloyed or high-alloyed steels with a low Fe content. Steel wires coated with brass are preferred.

Outside strands are to be understood as the strands that are visibly on the outside of the finished reinforcement rope.

It can in Verstärkun ^g sseil addition to the strands, one or more strands can be installed.

It is advantageous if the strands of at least one Seilumschlingun ^g sdraht total and / or at least one Seilumschlingungslitze are wrapped helically. Usually Verstärkun the invention consists ^g sseil from three to seven strands of up to four Seilumschlingungsdrähten and / or up to four Seilumschlingungslitzen.

According to the invention, strands are understood to be strands in the reinforcement rope, which are generally present in a larger number than the rope-wrapping strands. However, there can also be the same number of strands and rope-wrapping strands, one group of strands and the other group of rope-wrapping strands being named for distinction.

As a rule, the strands and / or the rope wrapping strands contain two to eight core wires; however, more core wires are also possible.

Likewise, the strands and / or the rope looping strands generally contain up to four strand looping wires, a larger number also being possible here.

The core wires are understood to be those wires in the strand or rope wrap strand which are generally in the majority.

Strand wrap wires are understood to be those wires in the strand or rope wrap strand which are generally in fewer numbers.

The strands or the rope wrapping strands can contain, for example, 3 + 1, 5 + 2, 6 + 3, 7 + 2, or generally n _{1 +} n ₂ wires, the first number or n _{1 being} the number of core wires and the second number or n ₂ indicates the number of strand wrap wires.

However, the same number of core wires and also strand-wrapping wires can also be contained in the strands or in the rope-wrapping strands. Such strands or rope wrapping strands then contain 2 + 2, 3 + 3, 4 + 4 or n ₁ + n ₂ , where n ₁ = n ₂ , wires, the first number or n _l as core wires and the second number or n _{2 are to} be understood as strand wrap wires.

It has proven to be advantageous if the core wires and strand-wrapping wires are of helical shape with the same pitch, the same pitch angle and the same direction of rotation, and the core wires of a strand are arranged bundled almost in phase. The preferred lay length is 10 to 20 mm.

It is particularly expedient if the core wires of the strands and / or the rope wrapping strands are arranged next to one another and against one another such that each of the core wires is in linear contact with at least one other core wire, the contact line running parallel to the direction of the core wires.

These strands are known as reinforcement ropes in simple stranding from DE-OS 26 19 086. The reinforcement Ropes have been found to be particularly favorable for use as reinforcement ropes in elastomeric products, since the loop wire also has a load-bearing function and, moreover, the elastomeric material also penetrates particularly well into the core area of the rope when the rope is embedded, and thus also corrosion of the wires severe damage is largely prevented.

Surprisingly, it turns out that when these ropes are stranded again, a reinforcement rope for elastomeric products is created which comes close to the favorable properties of the individual rope mentioned above.

It is very particularly advantageous if the strands and the rope wrapping wires and / or rope wrapping strands are of helical shape with the same pitch, the same pitch angle and the same direction of rotation, and the strands are arranged bundled almost in phase.

It is advantageous if the strand wrap wires are arranged out of phase with the core wires, preferably shifted by half a pitch length. The preferred lay length for the second stranding is 10 to 30 mm.

In this embodiment, the method known from DE-OS 26 19 086 is used to produce the rope for the second stranding, instead of the core wires Strands and instead of the roping wires, rope wrapping wires and / or rope wrapping strands are used.

It was surprising that with such a reinforcement rope, despite its generally considerably larger number of wires and thus its larger cross section, the equally good properties described above of the rope described in DE-OS 26 19 086 can be achieved.

The reinforcing ropes according to the invention are preferably used in the manufacture of pneumatic vehicle tires, in particular pneumatic tires for trucks or earth moving machines

The invention is explained in more detail with reference to the attached figures and examples.

• Figur 1 den prinzipiellen Aufbau eines erfindungsgemäßen Verstärkungsseiles mit vier Litzen und einem Seilumschlingungsdraht der Konstruktion 4 x (5 + 2) + 1
• Figur 2 den prinzipiellen Aufbau eines erfindungsgemäßen Verstärkun^gsseiles mit sieben Litzen und einem Seilumschlingungsdraht der Konstruktion 7 x ( 3 + 1) + 1
• Figur 3 den prinzipiellen Aufbau eines erfindungsgemäßen Verstärkungsseiles mit sieben Litzen und einem Seilumschlingungsdraht der Konstruktion 7 x (2+ 2) + 1
• Figur 4 den prinzipiellen Aufbau eines erfindungsgemäßen Verstärkungsseiles gemäß Anspruch 5 mit fünf Litzen und zwei Seilumschlingungsdrähten der Konstruktion 5 x (4 + 1) + 2
• Figur 5 den prinzipiellen Aufbau eines erfindungsgemäßen Verstärkungsseiles gemäß Anspruch 5 mit drei Litzen und einer Umschlingungslitze der Konstruktion (3 + 1) x (5 + 2)
• Figur 6 schematisch den Versuchsaufbau beim Korrosionsversuch
• Figur 7 schematisch den Versuchsaufbau bei der Bestimmung der Luftdurchlässigkeit des eingebetteten Verstärkungsseiles
• Figur 8 einen Schnitt durch den Prüfkörper, welcher bei der Bestimmung der Luftdurchlässigkeit eingesetzt wird
• Figur 9 schematisch den Aufbau eines Reifens, in welchen erfindungsgemäße Verstärkungsseile eingebettet sind.

Show it:

• Figure 1 shows the basic structure of a reinforcement rope according to the invention with four strands and a rope wrap wire of the construction 4 x (5 + 2) + 1
• 2 shows the basic structure of a Verstärkun invention sseiles ^g with seven strands and a Seilumschlingungsdraht the structure 7 x (3 + 1) + 1
• Figure 3 shows the basic structure of a reinforcement rope according to the invention with seven strands and a rope wrap wire of construction 7 x (2+ 2) + 1
• Figure 4 shows the basic structure of a reinforcing rope according to the invention according to claim 5 with five strands and two rope wrap wires of the construction 5 x (4 + 1) + 2
• 5 shows the basic structure of a reinforcement rope according to the invention according to claim 5 with three strands and a looping strand of the construction (3 + 1) x (5 + 2)
• Figure 6 schematically shows the test setup in the corrosion test
• Figure 7 schematically shows the experimental setup when determining the air permeability of the embedded reinforcement rope
• Figure 8 shows a section through the test specimen, which is used in determining the air permeability
• Figure 9 schematically shows the structure of a tire in which reinforcing ropes according to the invention are embedded.

FIG. 1 shows the basic structure of a reinforcement rope 1 according to the invention with four strands 2, which each consist of f core wires 3 and two strand strands 4 and one rope strapping wire 5. In general, the construction is 4 x (5 + 2) + 1 specified. The strands 2 are stranded in a cross lay. The strands 2 can preferably be constructed in such a way that the core wires 3 and the strand wrapping wires 4 are of helical shape with the same pitch, the same pitch angle and the same direction of rotation, and the core wires 3 of a strand 2 are arranged bundled almost in phase. The core wires 3 and strand wrap wires 4 are only in the upper half of Figure 1 shown. For better clarity, only the strand ^{2 is shown} as a thick cable without stranded wire 4 in the rope network.

Figure 2 shows the basic structure of a reinforcement rope 6 according to the invention with seven strands 7, which consist of three core wires 8 and a strand loop wire 9, and a rope loop wire 10. In general, the construction is indicated with 7 x (3 + 1) + 1. Here, too, the strands are stranded in a cross lay. The form of representation corresponds to that of FIG. 1.

Figure 3 illustrates the basic structure of Verstärkun inventive ^g sseiles 11 having seven strands 12 which each consist of two core wires 13 and two Litzenumschlingungsdrähten 14, and a Seilumschlingungsdraht 15. In general, the construction with 7 x (2 + 2) + 1 specified. The additional information given in FIG. 1 also applies analogously to FIG. 3.

FIG. 4 shows the basic structure of a reinforcement rope 16 according to the invention, in which five strands 17 and two rope wrap wires 20 of helical shape have the same pitch, the same pitch angle and the same direction of rotation, and the strands 17 are arranged bundled almost in phase, the rope wrap wires 20 are arranged out of phase by half a pitch length with respect to the strands 17. The strands 17 each consist of four core wires 18, each strand 17 being helically wrapped with a strand wrap wire 19. Strands are preferably used here, in which the core wires 18 and the strand wrapping supply wires 19 are of helical shape with the same pitch, the same pitch angle and the same direction of rotation, and the core wires 18 of a strand 17 are arranged bundled almost in phase.

Figure 5 shows the basic structure of a reinforcing rope 21 according to the invention according to claim 13, wherein three strands 22 and a Seilumschlingungslitze 25 equivalent of helical shape slope same Stei- ^g ungswinkels and the same rotational direction, and the strands 22 are arranged almost in phase bundled, wherein the cable wrap strand 25 is arranged out of phase with the strand 22 by half a pitch length. The strands 22 each consist of five core wires 23 and two Litzenumschlingungsdrähten 24. The Seilumschlingun ^g slitze 25 also consists of five core wires 26 and two Litzenumschlingungsdrähten 27 to be particularly advantageous, it can also in which reinforcing wire 21 according to Figure 5 can be viewed when in the strands 22 and also in the rope wrapping strand 25, the core wires 23 and 26 and the strand wrapping wires 24 and 27 are of helical shape with the same pitch, the same pitch angle and the same direction of rotation, and the core wires 23 and 26 of a strand 22 or 25 are arranged in almost the same phase . It is particularly favorable here if the strand wrap wires 24 and 27 are arranged out of phase by half a pitch length with respect to the core wires 23 and 26.

Example 1 Corrosion Tests

To demonstrate the good properties of the reinforcement ropes according to the invention, corrosion tests were carried out in accordance with an experimental setup shown schematically in FIG. 6, the results of the reinforcement ropes according to the invention being compared with previously conventional reinforcement ropes.

To carry out the corrosion test, test specimens 28 are produced in which two layers 29, each with fourteen ropes per 32 mm, are vulcanized into two different types of rubber in such a way that the two layers 29 are vulcanized together within a region B of 25.4 mm of the test specimen length. The area limits are 12.5 mm (area A) from one end and 50 mm (area C) from the other end face of the test specimen 28, the cable cross sections being visible on both end faces 30 and 31. The cables within the cable layers 20 and the two cable layers with each other are in parallel with each other Probenlängsrichtun ^g at a constant distance.

The finished test pieces 28 are flat each other with the shorter, not joined together by side in a 20% NaCl solution 32 in a container at an angle of 45 ° immersed to the bath surface so that the Eintauchlän ^G E D of the joined together by area 12,5 mm . Several samples of the different types of rope were produced, which were either not at all (immersion time 0 days) or immersed in the 20% NaCl solution for several days. Here two different, common types of rubber were used. After the immersion time, the rope layers of the test specimens were torn apart after the two longer, non-vulcanized sides 30 had been clamped in place. The degree of rubber coverage was assessed within the previously vulcanized area of both torn test specimen halves 29, a distinction being made between immersed (area D) and non-immersed area. 100% coverage means that neither rope nor rope parts are visible on both halves of the test specimen 29.

• Seil I: ein erfindungsgemäßes Verstärkungsseil gemäß Anspruch 4 und Figur 1, welches aus vier Litzen 2, bei welchen fünf Kerndrähte 3 und zwei Litzenum- schlin^gungsdrähte 4 von schraubenförmiger Gestalt gleicher Steigung, gleichen Steigungswinkels und gleicher Drehrichtung sind, und die Kerndrähte 3 einer Litze 2 nahezu phasengleich gebündelt angeordnet sind, und einem Seilumschlingungsdraht 5. Die Litzenumschlingungsdrähte 4 waren gegenüber den Kerndrähten 3 um eine halbe Steigungslänge phasenverschoben angeordnet. Die Kerndrähte 3 und die Litzenumschlingungsdrähte 4 hatten einen Drahtdurchmesser von 0,22 mm, während der Seilumschlingungsdraht 5 einen Durchmesser von 0,15 mm hatte. Die Verseilung der Litzen erfolgte im Kreuzschlag. Die Konstruktion wird üblicherweise wie folgt angegeben
  
• Seil II: Aufbau wie Seil I, jedoch andere Drahtzahlen der Konstruktion
  
• Seil III: Aufbau wie Seil I, jedoch andere Drahtzahlen, wie in Figur 2 dargestellt, der Konstruktion
  
• Seil IV: Aufbau wie Seil I, jedoch andere Drahtzahlen, wie in Figur 3 dargestellt, der Konstruktion
  
• Seil V: Aufbau wie Seil I, wobei anstatt des Seilumschlingungsdrahtes eine Seilumschlingungslitze um das Seil gewickelt war. Das Verstärkungsseil bestand aus drei Litzen und einer Seilumschlingungslitze, welche Litzen jeweils aus fünf Kerndrähten und zwei Litzenumschlingungsdrähten bestanden, der Konstruktion:
  
• Seil VI: ein Vergleichsseil, welches zweifach im Kreuzschlag verseilt ist, der Konstruktion
  

The following were used as ropes:

• Rope I: an inventive reinforcing cable according to claim 4 and Figure 1, which, same slope angle and the same rotational direction are made of four strands 2, in which five core wires 3 and two Litzenum- schlin ^g ungsdrähte 4 same of helical shape of slope, and the core wires 3 a Braid 2 are bundled almost in phase, and a rope wrap wire 5. The wire wrap wires 4 were arranged out of phase with the core wires 3 by half a pitch length. The core wires 3 and the strand wrap wires 4 had a wire diameter of 0.22 mm, while the rope wrap wire 5 had a diameter of 0.15 mm. The strands were stranded in a cross lay. The construction is usually given as follows
  
• Rope II: Construction like rope I, but different numbers of wires in the construction
  
• Rope III: Construction like rope I, but different numbers of wires, as shown in Figure 2, the construction
  
• Rope IV: Construction like rope I, but different numbers of wires, as shown in Figure 3, of the construction
  
• Rope V: Construction like rope I, whereby instead of the rope wrap wire a rope wrap was wrapped around the rope. The reinforcement rope consisted of three strands and a rope wrap wire, which strands each consisted of five core wires and two wire wrap wires, the construction:
  
• Rope VI: a comparison rope, which is twisted twice in the cross lay of the construction
  

Rope VI _I : a comparison rope, which is simply stranded, the construction:

The degrees of rubber coverage in% of the torn apart samples in which the inventive or comparative reinforcement ropes were embedded are shown in Tables I and II as a function of the immersion time.

The test specimens with reinforcement ropes according to the invention therefore behave more corrosion-resistant than the test specimens with comparison ropes.

example

In order to check what the quality of the embedding of a reinforcement rope according to the invention in the rubber is in comparison to the usual reinforcement ropes, the air permeability was determined according to FIG. 7, a test specimen according to FIG. 8 being used.

For this purpose, a 7.5 cm long reinforcement rope 36 is embedded in rubber 35, the reinforcement rope 36 being visible on both end faces of the test specimen 34. At the same time, a sealing washer 37 and a pipe stop piece 38 are embedded in the rubber 35 in each test specimen 34.

With the union nut 40, the test body 34 is connected gas-tight with a compressed air connection piece 41. The compressed-air connection piece 41 is connected via a Übergan sstück ^g 42, a pressure reducing valve 43 and a compressed air line 44 connected (not shown) to a compressed air source.

At the pipe connector 38, a pipe 39 is connected in a gastight manner, the free end of which is immersed in a tub 45 filled with water 46. The free end is bent upwards and is located under the opening of a measuring cylinder 47 which is filled with water at the start of the experiment and which is also immersed in the water bath 45, 46. With the valve 48, the height of the water column in the measuring cylinder 47 can be adjusted.

At the beginning of the air permeability determination, a pressure of 1 bar is set via the pressure reducing valve 43. Can air through the test specimen due to incomplete embedding of the reinforcement rope 36 in the rubber mass 35 penetrate, the resulting air bubbles rise in the measuring cylinder 47. The amount of air accumulating in the measuring cylinder 47 per unit of time is measured.

The following were embedded in rubber type 2 as reinforcement ropes:

The reinforcement ropes I and V according to the invention as in Example 1.

In addition, another rope VIII according to the invention was embedded, which is constructed like rope 1, but has two rope wrap wires, of the construction:

Ropes VI and VII from Example 1 were chosen as comparison ropes.

The results are shown in Table III.

The reinforcing ropes according to the invention are therefore completely embedded in the rubber mass.

FIG. 9 schematically shows the structure of a tire in which reinforcing ropes according to the invention are embedded. With 47 the tread of the tire is designated, which is constructed here as a radial tire. In the tread 47 two layers 48 and 49 of reinforcing ropes according to the invention are embedded, which run at a certain angle to the circumferential direction. This angle depends on the area of application of the tire. Reinforcement ropes 50 according to the invention are likewise embedded in a carcass 51 perpendicular to the circumferential direction of the tire - in the circumferential direction of the tire cross section. The reinforcing ropes according to the invention can also be embedded in the bead 57.

Claims (14)

1. reinforcing cable of metal wires for elastomeric products, consisting of at least two intertwined strands of two or more wires, characterized in that at least one outer strand of two or more ^g of at least one Litzenumschlin ungs- wire (4, 9, 14, 19 or 24) consists of helically wound core wires (3, 8, 13, 18 or 23). 2. Reinforcement rope according to claim 1, characterized in that each outer strand consists of two or more of at least one strand wrap wire (4, 9, 14, 19 or 24) helically wound core wires (3, 8, 13, 18 or 23) . 3. Reinforcement rope according to claim 1 or 2, characterized in that each strand (2, 7, 12, 17 or 22) from two or more of at least one strand wrap wire (4, 9, 14, 19 or 24) wound helically core wires (3, 8, 13, 18 or 23). 4. Reinforcement rope according to one of claims 1 to 3, characterized in that the wires are made of steel. 5. Reinforcement rope according to claim 1 or 2, characterized in that the strands (2, 7, 12, 17 or 22) in total of at least one wire rope (5, 10, 15, 20) and / or at least one rope wire (25) are helically wrapped. 6. Reinforcement rope according to claim 5, characterized in that the reinforcement rope (1, 6, 11, 16 or 21) consists of three to seven strands (2, 7, 12, 17 or 22). 7. reinforcement rope according to claim 5, 6 or 7, characterized in that the strands (2, 7, 12, 17 and 22) of up to four Seilumschlinun ^g wires (5, 10, 15 and 20) are helically wrapped. 8. reinforcing cord according to claim 5, 6 or 7, characterized ^e-g indicates that the strands (22) of up to four rope umschlin ^g ungslitzen (25) are helically wound. 9. Verstärkun ^g sseil according to any one of claims 1 to 8, characterized in that the strands (2, 7, 12, 17 or 22) and / or the Seilumschlinungslitzen (25) each have two to eight core wires (3, 8, 13 , 18, 23 and 26) included. 10. Reinforcement rope according to one of claims 1 to 9, characterized in that the strands (2, 7, 12, 17 or 22) and / or the rope wrapping strands (25) each have up to four strand wrapping wires (4, 9, 14, 19 , 24 and 27) included. 11. Reinforcement rope according to one of claims 1 to 10, characterized in that in the strands (2, 7, 12, 17 or 22) and / or in the rope wrapping strands (25) the core wires (3, 8, 13, 18, 23 and 26) and the strand wrap wires (4, 9, 14, 19, 24 and 27 are of helical shape with the same pitch, the same pitch angle and the same direction of rotation, and the core wires (3, 8, 13, 18, 23 and 26 ) of a strand (2, 7, 12, 17, 22 or 25) are arranged bundled almost in phase. 12. Reinforcement rope according to one of claims 1 to 11, characterized in that the core wires (3, 8, 13, 18, 23 or 26) of the strands (2, 7, 12, 17 or 22) and / or the rope wrap strands (25) are arranged side by side and against each other, and each of the core wires is in linear contact with at least one other core wire, the contact line running parallel to the direction of the core wires (3, 8, 13, 18, 23 and 26). 13. Reinforcement rope according to one of claims 1 to 12, characterized in that the strands (12, 17 or 22) and the rope wrapping wires (15 or 20) and / or rope wrapping strands (25) of helical shape of the same pitch, same pitch angle and are in the same direction of rotation, and the strands (12, 17 and 22) are arranged bundled almost in phase. 14. Use of the reinforcement ropes according to one of claims 1 to 13 for the manufacture of pneumatic vehicle tires, in particular pneumatic tires for trucks or earthmoving machines.

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