JP2000355890A - Production of steel cord and twisting machine used for the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steel cord comprising uniformly arranged wires even by carrying out the collection and twisting of wires under nonrestriction conditions by arranging plural reform pins on each side face of a square pillar of a preform apparatus zigzag and in a shifted state by the diameter of the wire between adjoining side faces so as not to make a reform phase uniform between the wires. SOLUTION: A tubular twisting machine in which plural reform pins 61-64 are arranged zigzag on side faces 6-1 to 6-6 of a prism such as a hexagonal pillar of a preform apparatus 6 in the direction of the generating line of the square pillar and in a shifted state by the diameter of the wire between adjoining side faces in the direction of the generating line is used. Plural wires released from plural bobbins are passed through the preform apparatus 6 and reformed. The wires are collected through a twisting guide and twisted to form a steel cord.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a steel cord and a tubular type twisting machine used for the method, and particularly to a tubular twisting machine having a preform device.

[0002]

2. Description of the Related Art Steel cords for reinforcing rubber articles such as pneumatic tires and conveyor belts are generally manufactured by twisting a plurality of strands. As shown in FIG. 1, a tubular type twisting machine is frequently used.

For example, a layer-twisted cord having a 3 + 6 structure applied to a pneumatic tire is manufactured by winding and twisting six strands of a sheath around a core having a 1 × 3 structure. be able to. That is, as shown in FIG. 1, the bobbin 2 around which the core 1 is wound is disposed outside the barrel 3, while the wire 4 serving as a sheath is provided.
a to 4f are wound around the bobbins 5a to 5f in the barrel 3
By disposing the core 1 and the sheath wires 4a to 4f on the barrel 3 and rotating the barrel 3,
Twisting is performed. Normally, on the exit side of the barrel 3, a helical shaping process having the same shape as that of the twisted sheath wire is performed by a preform device 6 as shown in FIG. By completing the twisting, the cord C is obtained.

[0004] Steel cords are required to have two basic performances. First, one of them is straightness. If the straightness is inferior, for example, the treat material is warped in a calendering process of tire production, which hinders the joining of the treat materials. Next, for example, in order to increase the durability of the tire, the rubber is required to have excellent rubber permeability, which allows the rubber to penetrate into the inside of the cord. The fact that there are gaps between the wires and that the number of gaps is large is advantageous for allowing rubber to penetrate into the core of the cord. For that purpose, it is important that the sheath wires are evenly arranged around the core without deviation in the cord cross section.

In order to arrange the sheath wires evenly around the core, it is effective to make the sheath wires uniform before they are twisted. Furthermore, if the sheath wires are of the same type, the wires will interfere with each other during the twisting process, causing the wires to protrude from the outer diameter of the cord. Because it will not be
The image is inevitable as a product.

As described above, straightness and uniform arrangement of sheath filaments are required as characteristics of the steel cord. However, straightness cannot be secured by a conventional twisting machine as shown in FIG. .

In other words, in the method using the preform device 6 and the voice 7 formed by a dice or the like, as shown in FIG. When strands are introduced into voice 7 and gathered,
At the entry side of the voice 7, the wire is subjected to the press bending process and is plastically deformed, so that the straightness of the wire and, consequently, the straightness of the cord are deteriorated.

As a method of suppressing the deterioration of straightness in the twisted gathering portion of the voice, instead of the voice,
As shown in FIG. 3, there is a method in which the sheath strand is passed through an annular twisting guide 8 having a diameter larger than the diameter of the cord, and the gathering point P of the strand is set to the exit side of the twisting guide 8 and twisted. In this method, excellent straightness can be obtained because plastic processing is not performed at the gathering point P of the strands.

[0009]

However, when the strands are gathered and twisted on the exit side of the twisting guide 8, the arrangement of the strands is uneven because there is no constraint as in the method shown in FIG. May be. That is, since the molding in the preform device 6 is uniform between the strands,
When twisting under unconstrained state shown in FIG. 3, the strands interfere with each other, so that the strand arrangement is disturbed, and the uniform strand arrangement is not realized.

Accordingly, an object of the present invention is to provide a method for obtaining cords in which wires are evenly arranged, even when the assembly and twisting of wires are performed under unrestricted conditions. The present invention is also to provide in conjunction with a twisted wire machine.

[0011]

The gist of the present invention is as follows. (1) After shaping a plurality of strands, the strands to be applied to the strands are shifted between strands when the strands are gathered and twisted on the guide exit side via a twisting guide. A method for manufacturing a steel cord.

(2) A method for manufacturing a steel cord according to the above (1), wherein the phase of the pattern given to each strand is shifted by the strand diameter between adjacent strands.

(3) The wires drawn out from the plurality of bobbins are
The preform device is a tubular stranded wire machine, which after being molded respectively, collects and twists element wires on the guide exit side via a twisting guide, wherein the preform device is a polygonal columnar body. A tuber, wherein a plurality of hammering pins through which the element wires are passed are arranged in a staggered manner in the direction of the generatrix of the prism, and the position of the group of hammering pins is shifted in the generatrix direction between the side faces. Twisting wire machine.

(4) The tuber twisting machine according to the above (3), wherein the position of the pin group is shifted by a wire diameter in the generatrix direction between adjacent side surfaces.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A twisting machine according to the present invention employs a twisting guide for a set of strands without using a voice. , The resulting code is straightforward. However, when the twist guide is used, the arrangement of the strands may be disturbed,
It becomes a new problem.

In order to investigate the twisting behavior of the strands on the output side of the twisting guide, the sheath strands were twisted using a ring as the twisting guide 8 as shown in FIG. The following knowledge was obtained. That is, the plurality of strands, which have been uniformly shaped by the preform device 6, try to be twisted at one point on the exit side of the twisting guide 8, but since the phase of the shaping is uniform between the strands, It is impossible to twist them as they are. In fact, it has been confirmed that the twisting guide (ring) 8 arranged in a direction orthogonal to the axis of the cord is tilted as shown in the drawing during the twisting, and this causes a phase shift Z between the strands at the twisted portion. Is caused. Thus, it has been found that the non-uniform arrangement of the strands in the twisted portion is caused by the uniform phase of the molding between the strands.

Further, as shown in FIG. 5, the molding of each of the strands was examined at the portion A after passing through the preform device 6 and at the portion B after twisting. As shown in FIG. 6, the result of the investigation shows that the difference in the molding amount of the strands at the portion A before the twisting is small, whereas the molding amount of the strands of the cord after the twisting greatly changes. From this result, it can be seen that interference between the strands occurs at the twisted portion and the uniform arrangement is hindered.

From the above examination results, it is important to shift the phase of the molding between the strands in order to avoid the uneven arrangement of the sheath strands in the twisting using the twisting guide. It has been found. Then, when we elaborated on the means for shifting the phase of the typing,
The effectiveness of the following means has been confirmed, and the present invention has been completed.

First, it is effective to adjust the molding position in the preform apparatus for each strand in order to shift the phase of molding between strands at the set point of twisting. That is, as shown in FIG. 7A, the preform device 6 includes a plurality of, for example, four habit pins 61 to 64 on each of the six side surfaces 6-1 to 6-6 of a hexagonal prism. It is arranged in a staggered manner in the generatrix direction of the hexagonal prism, and each side surface 6-1
The strands are shaped by passing the strands through 6-6 to 6-6 pinning pins 61-64. In the preform device 6, the position of the side group of pinning pins is shifted between the adjacent pinning groups, and the phase of the spiral knitting of the strands is shifted in the length direction between the strands. Do not disturb the twisting of the wires.

For example, as shown in FIG. 7 (b), between the side surfaces of the preform device 6, the pin spacing in the generatrix direction and the pin spacing in the direction perpendicular to the generatrix of the habit forming pin group are not changed. By shifting the relative positions of the attachment pins,
The phase of the molding can be shifted between the strands at the set point of the twisting. Here, as for the amount of displacement between the curling pin groups, the amount of displacement between adjacent side surfaces is preferably the wire diameter, as long as the shaping does not synchronize between the wires.

[0021]

EXAMPLES Inventive Examples Three strands (0.20 mm diameter) were twisted at a twist pitch of 10 mm. Six strands having a diameter of 0.36 mm were wound around a core at a twist pitch of 18 mm. When twisting steel cords of 3 + 6 structure using a tuber stranded wire machine,
As shown in FIG. 7, the arrangement of the bobbin in the barrel is made so that the wire drawn out from the bobbin far from the preform device 6 passes, and the group of pinning pins is moved away from the barrel 3 such that The relative positions of the hammering pin groups in are arranged with a shift amount of 0.36 mm in the generatrix direction. In addition, the pin arrangement in the individual habit pin group is such that the pin interval is 7.65 mm in the generatrix direction and 0.935 mm in the direction orthogonal to the generatrix.
To make the processing amount the same.

Here, the shift amount of the hammering pin group is the difference in the generatrix direction of the relative position of the hammering pin group between adjacent side surfaces of the preform device.
The pin group was successively shifted between adjacent side surfaces.

Conventional Examples 1 and 2 Also, as a comparison, as in the conventional case, a preform device in which the arrangement of the pinning pin groups is the same and the amount of engagement between the pin groups is the same, and the voice is twisted together. Twisted wires using (conventional example 1) or a twisting guide (conventional example 2) were also performed.

The straightness and the arrangement of the wires of the cords obtained in accordance with the above-mentioned conforming example 1 and conventional examples 1 and 2 were evaluated. In other words, straightness is obtained by 50 cm
After being cut to a length, the cord is placed on a flat horizontal surface without restraint, and as shown in FIG. 8, the deformation amount t (mm)
Was measured and evaluated. The smaller the value is, the better the straightness is. In addition, the arrangement of the strands can be adjusted by loosening the cord, observing the shape of each strand by enlarging it with a projector, measuring the wave height of the waveform of each strand, and determining the maximum value of the wave height difference between the strands. Displayed. The smaller the value, the more evenly arranged.

The results of these surveys are shown in Table 1 below.
By using the twisting machine of the present invention, it is possible to obtain a cord which is excellent in straightness and in which wires are arranged uniformly.

[0026]

[Table 1]

[0027]

According to the present invention, the assembling and twisting of the wires can be performed without restraint, and the twisting can be performed without difficulty, so that the wires can be evenly arranged in addition to the excellent straightness. Can be realized.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a tubular stranded wire machine.

FIG. 2 is an explanatory diagram of a twisted wire using a voice for twisting.

FIG. 3 is an explanatory diagram of a stranded wire using a twisting guide for twisting.

FIG. 4 is an explanatory diagram of a stranded wire using a ring as a twisting guide.

FIG. 5 is a schematic view showing part A and part B in the experiment shown in FIG.

FIG. 6 is a graph showing a typed amount for each strand;

FIG. 7 is a schematic diagram showing a preform device.

FIG. 8 is a diagram showing a point of evaluation of straightness.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Core 2 Bobbin 4a-4f Element wire 5a-5f Bobbin 6 Preform apparatus 7 Voice 8 Twisting guide

Claims (4)

[Claims] 1. After each of a plurality of strands is typed,
A method of manufacturing a steel cord, comprising: when assembling and twisting wires on a guide exit side via a twisting guide, a phase of a mold applied to each wire is shifted between the wires. 2. The method of manufacturing a steel cord according to claim 1, wherein the phase of the molding applied to each strand is shifted by the strand diameter between adjacent strands. 3. A tubular twisting machine, wherein strands fed from a plurality of bobbins are respectively shaped by a preforming device, and then the strands are assembled and twisted on a guide exit side via a twisting guide. In the preform apparatus, a plurality of hammering pins through which element wires are passed are arranged in a staggered manner in the direction of the generatrix of the prism on each side surface of the polygonal columnar body. Tuber stranded wire machine, characterized in that is shifted in the generatrix direction between the side surfaces. 4. The tuber twisting machine according to claim 3, wherein the position of the group of pinning pins is shifted by a wire diameter in the generatrix direction between adjacent side surfaces.