JPH0835187A - Metallic cord, its production and composite of the same cord with rubber - Google Patents

Abstract

PURPOSE:To obtain a metallic cord for reinforcing a rubber article, hardly changing a cross-sectional shape in the longitudinal direction, excellent in fatigue resistance, good in rubber permeability into the interior thereof, excellent in corrosion resistance and having a structure of [3 (parallel)+(n)] [1<=(n)<=8]. CONSTITUTION:This metallic cord is obtained by retaining a fine wavy curl in at least one of three metallic filaments 1 in the first group, forming interstices for penetrating a rubber among the parallel doubled three metallic filaments 1 by the curl and laying preferably 1-2 metallic filaments 2 in the second group around the metallic filaments 1 of the first group. Since the number of the metallic filaments in the first group is 3 of the stablest form, the cord is excellent in fatigue resistance. Since the rubber readily penetrates into the core comprising the metallic filaments in the first group, the corrosion resistance is excellent.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal cord having excellent corrosion resistance and fatigue resistance, a method for producing the same, and a tire and a conveyor belt which are made by embedding the metal cord as a reinforcing material in rubber and have excellent durability. , High pressure hoses and other composites.

[0002]

2. Description of the Related Art Metal cords used for reinforcing rubber articles are usually made of high-carbon steel wire (JIS G3502 piano wire) and have brass, copper, zinc, etc. on the surface to provide adhesion to rubber. Is metal-plated and wire-drawn to a diameter of 0.1-0.5 mm, then single-twisted, double-twisted, or layer-twisted, widely used as a reinforcing material for automobile tires, conveyor belts, high-pressure hoses, etc. Has been. For example, for a radial tire for a passenger car and a radial tire for a light truck, a belt portion reinforcing material is 4
1 x 4 with 5 or 5 metal filaments twisted together
Alternatively, a metal cord having a 1 × 5 single twist structure is used.

Quality characteristics required of the metal cord as the rubber reinforcing material include adhesiveness with rubber, corrosion resistance, fatigue resistance, and various other mechanical performances (cutting load, rigidity, etc.). . Among these, regarding corrosion resistance, when the rubber uncovered part is present in the metal cord embedded in rubber, when the tire is stepped on stones, nails, etc. while running, the scratch reaches the metal cord The cords corrode within a short period of time due to the moisture penetrating through the scratches, and the cutting load and fatigue resistance of the cords deteriorate. Further, the adhesion between the cord and the rubber may be deteriorated, and the cord may be peeled off to cause quality trouble due to separation of the tire.

The above-mentioned 1 × 4 or 1 × 5 closed cord, which is commonly used, has a cross-sectional shape as shown in FIG. 5, and has a cavity at the center of the cord. For this reason, when these metal cords are embedded in rubber, the rubber does not penetrate into the cord, and a hollow space where the rubber is not coated is generated. Such a composite of a metal cord and a rubber having a hollow space inside has a short service life because it causes quality troubles such as corrosion of the metal cord and separation of the metal cord and rubber due to permeation of water.

In order to solve this problem, attempts have been made to improve a metal cord which eliminates a rubber uncovered portion. For example, Japanese Patent Application Laid-Open No. 55-90692 proposes an open cord in which metal filaments 2 are twisted so that there is a gap between them, as shown in FIG.
No. 31438 and Japanese Examined Patent Publication No. 29408/1990 propose a 2 (parallel) +2 (or 3) cord shown in FIG. 4 in which almost no void exists inside the cord, both of which have already been put into practical use as reinforcing materials for tires. There is.

[0006]

The above-mentioned open cord and twisted structure of 2 (parallel) + 2 (or 3) cords have been proposed for the purpose of improving the rubber penetration into the cord, but the former open cord. Since the cords are easily stretched with low tension, when tension is applied to the cords in the calendering process for aligning the cords during tire manufacturing, the cords are stretched and at the same time the metal filaments are attracted to each other, which reduces the gap between the metal filaments. It is easy to get in and out, and rubber intrusion tends to be insufficient. Further, there is a drawback that the bulge of the cord is crushed under the pressure during the vulcanization step after tire molding, the gap between the metal filaments is reduced, and it becomes difficult for rubber to enter. Furthermore, even in the production of such an open cord, it is extremely difficult to obtain a uniform twist structure in the longitudinal direction of the cord because the twisting is unsuccessful. There is also a drawback that the distribution of the metal filaments in the above is not uniform, the elongation of the cord due to the tension load is not constant, and the cord intervals are not uniform when the cords are aligned in the calendar process.

On the other hand, the latter 2 (parallel) + 2 (or 3) cord has good rubber permeability into the cord, but the cross section of the cord has large irregularities in each part in the longitudinal direction and is not nearly circular. In addition, when the cords pass through the guide rollers or the like in the calendar process, the cord intervals are likely to change and become non-uniform. Further, there is a problem that the fatigue resistance is inferior to that of a cord having a transverse cross section that is stable in the longitudinal direction, such as a 1 × 4 or 1 × 5 structure.

The present invention improves the permeability of rubber to the inside of the cord by increasing the rubber coverage and prevents corrosion due to moisture penetration without causing problems in the above-mentioned calendar process and deterioration of fatigue resistance. The present invention aims to provide a cord, a method for manufacturing the cord, and a composite material such as a tire, a conveyor belt, and a high-pressure hose that has improved durability by using the cord as a reinforcing material.

[0009]

DISCLOSURE OF THE INVENTION The cord of the present invention devised to solve the above-mentioned problems is composed of three parallel cords.
N (1 ≦ n ≦ around the first group of metal filaments 1 of the book
8) A metal cord having a 3 (parallel) + n structure formed by twisting two metal filaments 2 of the second group, and at least one of the metal filaments 1 of the first group that does not twist.
In the twisted state with the n second metal filaments 2 of the second group, one metal filament has a wavy habit smaller than the cord twist pitch. Among 3 (parallel) + n structure metal cords,
In particular, the invention is suitable for a cord having a twist structure of 3 (parallel) +1 (or 2).

The metal filament 1 having the wavy habit has a pitch p ₁ = 0.20P to 0.75P (P is a cord twist pitch) and a height h before twisting the surrounding second group of metal filaments 2 together. ₁ = 0.18 to 0.50 mm spiral wave-like habit is applied, and the habit is twisted by the metal filaments 2 of the second group to form a wave pitch p = 0.21 P ~
The height is changed to 0.77P and the height h is 0.05 to 0.25 mm. This wavy habit added before twisting may be replaced with a two-dimensional wavy shape if the pitch and height ranges are not changed.

Further, the twist pitch P of the cord is preferably 10 mm or more, and the diameter of the metal filaments 2 of the second group is 3 in the first group, especially when the number is 1 or 2. It is desirable that the diameter is equal to or smaller than the diameter of the metal filament 1.

Further, the metal filament constituting the metal cord of the present invention is subjected to metal plating on the surface in order to improve the adhesiveness with rubber. The metal plating is brass, copper,
Ternary alloy plating in which Co, Ni, Sn or the like is added to zinc or brass is desirable.

Next, in the metal cord, when the number of squeezed wires of the first group of metal filaments 1 is m (m = 1 or 2), m metal filaments are rotated with corrugated pins. The individual metal filaments are passed through a corrugating device and, in this step, the metal filaments having the spiral wave-like habit and (3-m) metal filaments not having the habit are aligned to form a second group of metal filaments 2. It is manufactured by introducing a swingable cradle having a feeding mechanism of No. 3 into a double twisting and twisting machine arranged in a flyer and twisting around n metal filaments 2 fed from the feeding mechanism around the double twisting and twisting machine. .

Further, when the number of the entanglement of the first group of metal filaments 1 is set to 3, the three metal filaments 1 are false twisted (untwisted after twisting) by one false twisting device. A spiral wave-like habit is attached to each metal filament all at once, and the entangled metal filaments are aligned and introduced into the above-mentioned double-twisting wire machine, and n pieces of the n-th wire supplied in the twisting machine are provided around it. Two groups of metal filaments 2 are twisted together.

With respect to the one in which the spiral wave-like habit is replaced by a two-dimensional wave, when the number of habits is three or less, each of the metal filaments to be habitually applied is a two-dimensional wave between a pair of meshing gears. The double-twisting and twisting machine described above is made by passing through one corrugating device that imparts a wave, and arranging the metal filaments that have been stiffened here and the number of non-stiffened metal filaments To introduce.

When the curling is performed by a rotary corrugating device, the device is rotated in the same direction as the double-twisting machine, and when the false twisting device is used, the device is rotated by two. It is better to reverse the twisting and twisting machine.

Tires, conveyor belts, high-pressure hoses, etc. made by embedding such metal cords in a rubber mainly composed of natural rubber or synthetic rubber as a reinforcing material are the rubber composites of the present invention. Greater durability than conventional composites reinforced with known metal cords.

[0018]

The metal cord of the present invention is twisted in a tightly twisted state. In this state, some of the metal filaments 1 of the first group are twisted with the metal filaments 2 of the second group. Since small wavy habits are applied in addition to habits, a gap necessary for rubber intrusion is generated between adjacent filaments at least at one place. Therefore, unlike cords with a weak twist such as open cords, the elongation in the low load range does not increase, the metal filaments are attracted during the calendering process, the gap between the filaments is closed, and the instability of elongation causes the alignment. Sometimes the code gap does not become non-uniform. Also, the first group of metal filaments 1 has three of the most stable structures in the twisted state with the second group of metal filaments 2, so the cross-sectional shape changes greatly in the cord longitudinal direction 2 (parallel). Unlike the code of +2 (or 3) structure, the change in cross-sectional shape is relatively small, and there is no decrease in bending fatigue and deterioration of twist stability.

As described above, according to the present invention, the permeability of rubber can be improved without adversely affecting other properties required for the metal cord as a rubber article reinforcing material, and the rubber article can be remarkably improved. Leads to improved durability.

Here, regarding the twisted structure, the number of the metal filaments 2 of the second group is 1 ≦ n ≦ 8, and particularly, n is 1.
Or, the reason why 2 is appropriate is as follows.

The main twist structure can be considered as a kind of two-layer twist structure, and the first and second groups of metal filaments 1 and 2 are used.
Assuming that the wire diameters are the same, considering rubber intrusion into the metal filament 1 of the first group, nmax 8 3
(Parallel) +8 structure is the limit. On the other hand, n is changed from 1 to 3 (parallel) +1 has already been put to practical use 2
Since it can be used as an alternative code for (parallel) +2, n
The minimum value of was 1.

Of these, this time, since it was selected as an alternative cord having a 1 × 4, 1 × 5 single twist structure or a 2 (parallel) +2 (or 3) structure, 1 or 2 was set as a preferable value for n. However, it goes without saying that n of 3 to 8 has the performance as an alternative code such as 2 + 7 or 3 + 9 used for tires for light trucks or trucks / buses.

Next, regarding the wavy habit imparted to at least one of the first group of metal filaments 1, the pitch is regular before and after the twisting, but the height of the wave is first. Since the filament is large and small in the twisting process, the filament is stretched, and the pitch p after the twisting is slightly larger than the pitch p ₁ before the twisting. As a result, the preforming pitch p ₁
If is too large, the waves tend to disappear due to frictional resistance with various guides when the cords are twisted together, making it difficult for rubber to enter the inside of the first group of metal filaments. On the other hand, if the pitch p ₁ is too small, the filament is subjected to severe twisting and bending deformation, resulting in a decrease in strength and a decrease in fatigue resistance, and the rotation corrugating device of FIG. 2 (a) and that of FIG. When the false twisting device is used, high-speed rotation is required, while when the two-dimensional corrugating device of FIGS. 2B and 2D is used, precise downsizing of the tooth profile is required, and the equipment cost is also high. In addition, the cost burden becomes heavy.

Therefore, as a preferable value for avoiding these problems, the pre-pitching pitch p ₁ is selected to be 0.20 to 0.75 times the cord twisting pitch. The wave pitch p after twisting is slightly larger than p ₁ due to the elongation of the corrugating filament, and is 0.21 to 0.77 times the cord twist pitch P.

The height h of the wave after twisting should be such that there is a gap into which the rubber can penetrate inside the first group of metal filaments, and if this becomes too large, the cord diameter increases and the cord with a tighter twist is obtained. Since it becomes a kind of open cord state deviating from the above and the above-mentioned problem is likely to occur, the thickness is set to 0.05 to 0.25 mm in consideration of these.

On the other hand, the height h ₁ of the wave before twisting is lowered because the height of the wave becomes low due to the ironing due to contact with various guides during the twisting process. Is a value that can be maintained within the above range from 0.18 to
We chose a value of 0.50 mm.

The wave pitch and height referred to here are defined as shown in FIG. 3, and the preferable numerical limitation is given regardless of whether a spiral wave or a two-dimensional wave is given. The same can be said.

On the large side, the twist pitch P of the cord may be within the range of commonly used cords, but on the small side, the twist amount per unit length of the filament is large, so that In consideration of the fact that the contact resistance with various guides becomes large during the twisting process and the curl of the corrugated filament is easily erased, it was set to 10 mm or more.

When the number of the second group of metal filaments 2 is limited to one or two, the purpose is to restrain the first group of metal filaments to retain the performance as a cord. From the viewpoint of making the cord diameter compact, the diameter is preferably as thin as possible. However,
From the viewpoint of maintaining the cord strength, the first group of metal filaments 1
If the diameters of the are relatively small, the diameters may be the same.

Next, in the method for producing a metal cord of the present invention, a twisting and twisting is performed twice on a metal filament to be squeezed by using a rotating corrugating device having a squeezing pin, a corrugating device for a meshing gear or a false twisting device. Apply a wavy habit on the upstream side of the wire machine, align it with the metal filaments (minimum number is 0) that are not to be squeezed, and introduce it into the double-twisting wire machine, and n other metal filaments on the outer circumference. Since it is twisted together, fine waviness can be uniformly and efficiently performed with a simple device, which leads to efficient production of metal cords, cost reduction, and quality improvement.

[0031]

FIG. 1 shows an example of a cross section of a metal cord of the present invention. The first group of metal filaments 1 is finely corrugated on some of the three. The metal cord 3 of the present invention can be obtained by aligning the first group of metal filaments 1 in parallel and twisting the second group of metal filaments 2 around them at a predetermined pitch. The second group of metal filaments 2 is
The metal filaments 1 of the first group are constrained, and even if the number is one, the purpose is achieved. Therefore, the number of the metal filaments 2 is at most 8, preferably 1 to 2.

Next, a method of manufacturing the metal cord of the present invention will be described with reference to FIGS. 2 (a), (b), (c) and (d).

FIG. 2A shows a case where only one of the three first-group metal filaments 1 fed from the supply reel 5 has a wavy habit. In this case, the metal filament 1 which is the subject of the curling is passed through the rotary wave imparting device 8.

The rotary corrugating device 8 rotates the wave shaping pin 6 around the filament pass line while squeezing the filament with the zigzag arrangement of the wave shaping pins 6 (the rotation direction thereof is a double twisting and twisting machine as shown in the figure). It is preferable that the direction is the same as that of No. 14). Here, a fine spiral wave shape is attached to the metal filament 1 passing through with bending deformation and twisting. When the number of curl is two, two rotary wave imparting devices 8 are installed and the curl is separately imparted to the two metal filaments.

Further, as shown in FIG. 2B, a two-dimensional corrugating device 9 may be used, in which the metal filament 1 is passed between the pair of meshing gears 7, 7 to make a zigzag pattern. In this case, as shown in FIG. 2 (d), since a plurality of metal filaments 1 can be passed in parallel between a pair of meshing gears, when the number of squeezing is 1 and of course 2 or 3 As for the two-dimensional corrugating device 9, only one is required.

Further, when a spiral wave-like habit is applied to the three metal filaments 1, provision of three rotary wave imparting devices 8 is disadvantageous in terms of equipment cost. Therefore, the false twist shown in FIG. The device 16 is used to make a habit. It is preferable that the false twisting device 16 rotates in the opposite direction to the double twisting and twisting machine 14,
Rolling roller 1 for backflow propagation of twist due to twisting to the upstream side
While preventing with 5, false twisting (twisting after untwisting) is performed and the three metal filaments 1 are simultaneously given a habit.

In this way, when the required number of metal filaments 1 are provided with a wavy habit, the three metal filaments 1 are aligned, and the double-twisted stranded wire is passed through the wire hanging roller 15 of FIG. 2 (a). Installed in machine 14.

The double-twisting machine 14 has a swingable cradle 11 equipped with a supply mechanism for the second group of metal filaments 2 including the supply reel 10 inside a flyer 13, and further has an inlet side. Two turn rollers 1 each on the exit side
2 has a structure in which the reels 10 are provided around the first group of metal filaments 1 introduced without twisting.
The second group of metal filaments 2 supplied from The double twist here is performed while suppressing backflow propagation of the twist to the upstream side, which is caused by the temporary double twist by the wire hanging roller 15 of FIG. 2A, and then is guided once into the cradle to Formal double twisting is performed when the two groups of metal filaments 2 are wound around the outer circumference, and the pitch of the waves of the stiffened metal filaments 1 is slightly increased, while the height of the waves is slightly decreased.

After that, the cord which is almost close to the finished product is introduced into the false twisting device 16 for adjusting the residual torsion, twisting and untwisting, and the completed metal cord 3 is taken by the capstan 17. It is wound around the winding mechanism 19 while being guided by the traverse roller 18.

A more detailed embodiment will be described below.

0.25 mm diameter with brass plating on the surface
2 of the metal filaments 1 of FIG. 2 are aligned, and the three metal filaments 1 of FIG. 2C are collectively subjected to a spiral wave-like habit, and then arranged behind the false twisting device 16. In the equipment after the wire-rolling roller 15 in FIG. 2A, one of the second group of metal filaments 2 (the diameter and configuration of which are the same as the metal filament 1) is twisted around the first group of metal filaments and the pitch P = The metal filaments 1 twisted together at 14 mm have a wave pitch of 6.2 mm (0.44 P) and a wave height of 0.08 mm. A metal cord (Example 1) was obtained.

Further, assuming that the number of the metallic filaments 1 to be struck is one, the straits are given to the rotary wave imparting device 8 shown in FIG. 2 (a).
1 and the other parts are the same as those of the first embodiment.
A metal cord having a cross-sectional shape as shown in (b) (Example 2) and a metal cord using the conventional method (Comparative Example 1) with the number of staggered metal filaments 1 being 0 were prepared.

Further, the diameters of the metal filaments 1 and 2 were changed to 0.28 mm, and the metal cords of Examples 3 and 4 and Comparative Example 2 were produced in the same manner as above except for the manufacturing method and the sectional structure.

Similarly, in the same manner as in Examples 1 and 2, only the wave shape is changed, that is, a two-dimensional wave is applied to the metal filament 1 by the two-dimensional wave applying device 9 shown in FIG. Under the same conditions as in Examples 1 and 2, the metal cords of Examples 7 and 8 were produced by twisting the second group of metal filaments around the first group of metal filaments.

In addition, the corrugated shape of Example 1 is replaced with an unfavorable one, specifically, the pitch p of the waves applied to the metal filament 1 is made larger than that of Example 1 and 0.80P after twisting. (= 11.2 mm) (Comparative Example 3) and a cord having a twist pitch P of 8 mm (this is less than the lower limit of the preferred numerical value) (Comparative Example 4) are also prepared and aligned in parallel. The diameter of the group of metal filaments 1 is relatively large (0.30 mm and 0.32 mm)
The metal cord (cord having the cross section of FIG. 1E) in the case of was also made. In addition, in addition, the known 2 shown in FIG.
(Parallel) +2 structure, filament diameter 0.25mm cord (Conventional example 1) and 0.28mm cord (Conventional example 2)
I also prepared.

Using each of the above samples, the rubber coverage when embedded in rubber, which is a substitute characteristic of corrosion resistance, was measured, and as a substitute characteristic of fatigue resistance, a cord axial compression of a composite of cord and rubber was performed. A fatigue test was conducted.

[0047]

[Table 1]

As can be seen from Table 1, Examples 1-10
Is a first group of metal filaments 1 as compared with Comparative Examples 1 to 4.
The amount of rubber invading the inside of the core is dramatically improved, and the rubber coverage is very good. Moreover, the result of the compression fatigue test is superior to that of any comparative example.

Further, in comparison with the conventional examples 1 and 2, the rubber coverage is at a level at which there is no problem although it is slightly inferior in terms of the cross-sectional structure, while the compression fatigue characteristic is in the longitudinal direction of the cord having the cross-sectional shape. Significant improvement can be seen due to the lesser degree of change.

[0050]

As described above, in the metal cord of the present invention, the first group of metal filaments 1 arranged in parallel is secondly divided from the conventional two to the most stable three.
The metal filaments 2 of the group are twisted together, and at least one of them is provided with a wavy habit smaller than the cord twist pitch in order to compensate for the defects of the core formed by converging three metal filaments 1. It has good rubber penetration, excellent corrosion resistance, stable cross-sectional shape in the longitudinal direction of the cord and excellent fatigue resistance, and sufficiently satisfies the properties required for a reinforcing material for rubber articles.

Therefore, a rubber compound such as a tire, a conveyor belt and a high pressure hose made by using the metal cord as a reinforcing material has excellent durability and exhibits stable performance for a long period of time.

Further, according to the manufacturing method of the present invention, a simple corrugating device is installed in front of the double twisting and twisting machine, and the number of units used is reduced as much as possible so that the metal filaments 1 of the first group are finely divided. Since it efficiently imparts a uniform wavy habit, it is possible to economically mass-produce metal cords that are excellent in both quality and performance.

[Brief description of drawings]

FIG. 1A is a cross-sectional view showing an example of a metal cord of the present invention. FIGS. 1B to 1E are cross-sectional views of other examples.

2A is a schematic diagram showing an example of a metal cord manufacturing apparatus of the present invention, FIG. 2B is a schematic diagram showing another example of a corrugating apparatus, and FIG. 2D is one two-dimensional wave. FIG.

FIG. 3 is an enlarged plan view of a metal filament with a spiral wavy habit.

FIG. 4 is a cross-sectional view of a conventional 2 (parallel) +2 structure cord.

FIG. 5 (a): A cross-sectional view of a cord having a conventional 1 × 5 structure. (B): A cross-sectional view of a cord having a conventional 1 × 4 structure.

FIG. 6 is a cross-sectional view of a conventional 1 × 5 open cord.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st group metal filament 2 2nd group metal filament 3 Metal cord 4 Assembly guide 5 Metal filament 1 supply reel 6 Wave shaping pin 8 Rotational corrugating device 9 Two-dimensional corrugating device 10 Metal filament 2 supply reel 11 Cradle 12 Turn roller 13 Flyer 14 Double twisting and twisting machine 15 Wire hanging roller 16 False twisting device 17 Take-up capstan 18 Traverse roller 19 Winding mechanism

Claims (12)

[Claims] 1. 3 (parallel) + n formed by twisting n (1 ≦ n ≦ 8) second group of metal filaments 2 around a first group of three metal filaments 1 aligned in parallel. A metal cord having a structure, wherein at least one filament in the first group of metal filaments without twist is n
A metal cord having a wavy habit smaller than a cord twist pitch in a state where the second group of metal filaments 2 of the book are twisted together. 2. 3 (parallel) +1 where n is 1 or 2
The metal cord according to claim 1, which has a twist structure of 3 (parallel) +2. 3. The metal filament having the wavy habit has a pitch p ₁ = 0.20 to 0.75 P (P = cord twist pitch) and a height before twisting the surrounding second group of metal filaments 2 together. A spiral wave-like habit of h ₁ = 0.18 to 0.50 mm is applied, and the habit is twisted, whereby a pitch p = 0.21 to 0.77P and a height h =
The metal cord according to claim 1 or 2, which has a diameter of 0.05 to 0.25 mm. 4. The spiral wavy habit according to claim 3, which is applied to at least one metal filament in the first group of metal filaments, is replaced with a two-dimensional wavy habit, and a peculiar pitch before and after twisting and The metal cord according to claim 1 or 2, which has the same height as the corrugated shape of claim 3. 5. The metal cord according to claim 1, wherein the twist pitch P of the cord is 10 mm or more. 6. The diameter of the second group of metal filaments 2 is
The metal cord according to any one of claims 2 to 5, which has a diameter equal to or smaller than the diameter of the three metal filaments 1 of the first group. 7. The method for producing a metal cord according to claim 1, wherein the number of the entanglement of the first group of metal filaments 1 is m (m = 1 or 2).
Individual metal filaments through a rotary corrugator with corrugated pins, in this step a spiral corrugated metal filament and (3-m) non-stratified metal filaments. An oscillating cradle for aligning the filaments and aligning the supply mechanism of the second group of metal filaments 2 is introduced into a double twisting and twisting machine arranged in the flyer, and is fed from the supply mechanism around it. A method for producing a metal cord, which comprises twisting together metal filaments 2 of a book. 8. The method for producing a metal cord according to claim 7, wherein the rotation direction of the rotating wave attaching device is the same as the rotation direction of the double twisting and twisting machine. 9. The method for producing a metal cord according to claim 1, wherein the number of the entanglement of the first group of metal filaments 1 is 3, and the number of the three metal filaments 1 is 1. 7. The double-twisted twisted wire according to claim 6, wherein the false twisting device performs false twisting (twisting after twisting) to collectively attach a spiral wave-like habit to each metal filament, and the metal filaments having the quirks are aligned. 1. A method for producing a metal cord, which comprises introducing into a machine and twisting together n second-group metal filaments 2 of the second group supplied in a twisting machine. 10. The method for producing a metal cord according to claim 9, wherein the false twisting device is rotated in a direction opposite to a double twisting and twisting machine. 11. The method for producing a metal cord according to claim 1, wherein the first group of metal filaments 1 has the number of stiffened wires of 1 to 3. Through a corrugating device that applies a two-dimensional wave between a pair of meshing gears, and the metal filaments that have been stiffened here and the number of non-stiffened metal filaments that is the number of stiffened filaments reduced from three 7. A metal cord produced by aligning and introducing the same into the double-twisting wire machine according to claim 6 and twisting together n second metal filaments 2 of the second group supplied in the wire-twisting machine. Method. 12. A rubber composite, such as a tire, a conveyor belt, a high pressure hose, which is made by embedding the metal cord according to any one of claims 1 to 6 in a rubber mainly composed of natural rubber or synthetic rubber as a reinforcing material.