JP2009190552A - Bead core - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bead core attaining reduction of man-hour of work required for constitution of a bead core and enhancing shape-retaining property of a lateral cross section outer contour shape of a wound annular body. <P>SOLUTION: At least one portion in a circumferential direction of the wound annular body 3 constituted by winding one or a plurality of bead wires 2 in a circular ring-like shape and having the lateral cross section outer contour shape forming a polygonal shape is constrained by winding a steel wire 4 applied with plating in a direction perpendicular to the bead wire 2 to provide the bead core 1. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a bead core, and more particularly to a bead core having improved shape retention of a structure of a wound annular body formed by winding a bead wire in an annular shape.

  The bead core embedded in the bead portion of the pneumatic tire allows the end portion of the fiber forming the carcass ply and the ply cord of the steel wire to be wound and fixed, and also functions to secure the fit with the applied rim.

  The bead core winding annular body for such a bead core is formed by, for example, continuously winding one bead wire while shifting the position in the direction of the center axis of a required ring, to form one layer, Such a layer can be formed by repeating as necessary. On the other hand, in the case where the wound annular body is formed by a plurality of bead wires, a plurality of bead wires arranged in the central axis direction are continuously wound in the axial direction and the radial direction, thereby predetermined winding. A circular body can be formed.

  In order to maintain the shape of such a bead wire wound annular body in a predetermined shape, the wound annular body is bound and fixed with a cloth at least at one place in the circumferential direction. As described, it is known to bind and fix an annular body of a steel wire strand having a rectangular cross-sectional shape by plastic deformation of a crimping tool.

However, the bead core configured in this manner requires a lot of man-hours for fixing the bead wire or the steel wire wound annular body, and the binding force of the wound annular body in the product tire is not sufficient. There was a risk of losing shape.
In particular, when a flat plate is bent and wrapped around an annular body, the outer circumferential shape of the cross section is a polygonal annular body, and the annular body and the binding part are caused by local irregularities in the binding part. Due to the gap between the two, it was difficult to maintain the outer contour shape, and there was a high risk of deformation.
JP 2007-22414 A

  Accordingly, an object of the present invention is to provide a bead core in which the man-hour required for the construction of the bead core is reduced and the shape retaining property of the outer contour shape of the cross section of the wound annular body is improved.

  The bead core according to the present invention is formed by winding one or a plurality of bead wires in an annular shape, and has at least one place in the circumferential direction of a wound annular body having a polygonal outer profile in cross section. It is restrained by winding the plated steel wire in a direction substantially perpendicular to the bead wire.

Here, “steel wire” refers to a monofilament made of steel.
“Peeled steel wire” is, for example, a steel cord having a surface plated with brass or bronze.
Moreover, the bead wire here shall include both the thing by which the rubber | gum coating is given to the circumference | surroundings and the thing which is not given.

  In such a bead core, the steel wire is preferably wound at least twice at two or more positions in the circumferential direction of the wound annular body.

  Preferably, the diameter φ (mm) of the steel wire is 0 <φ ≦ 1.

  As described above, it is difficult for the conventional bead core to keep the outer contour shape in a predetermined shape due to the occurrence of local unevenness on the binding portion or the lack of restraining force on the wound annular body. In addition, it took time to maintain the shape of the wound annular body.

Accordingly, in the bead core of the present invention, at least one place in the circumferential direction of the wound annular body formed by winding the bead wire in an annular shape is substantially orthogonal to the bead wire of the plated steel wire. By constraining under the plastic deformation of the steel wire by winding in the direction, it is possible to easily and quickly perform the shape maintaining work of the outer contour shape of the wound annular body with less man-hours. At the same time, the tight winding of the steel wire around the winding annular body can effectively prevent the occurrence of local unevenness on the restraint portion itself.
In addition, by winding the steel wire in a direction perpendicular to the bead wire and restraining the annular body, a sufficiently large restraining force is generated, and the annular body is accurately placed around the wound annular body. Can be restrained. As a result, the deformation of the shape of the bead portion of the tire can be suppressed and the product quality can be improved.
And shape restraint of a bead part can be controlled by restraining with the steel wire which gave plating.

Hereinafter, the bead core of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a front view showing one embodiment of a bead core of the present invention. FIG. 2 is an enlarged cross-sectional view of the bead core of FIG. 1 at a restraining position.

  In the figure, 1 is a bead core, 2 is a bead wire having a square hard wire cross section, 3 is a plurality of bead wires 2 arranged in parallel, stacked a plurality of times and wound into an annular shape to form an annular shape. The outer contour shape of the cross section is a polygon, and FIG.

  And here, at least one place in the circumferential direction of the wound annular body 3, two places in the figure, the plated steel wire 4 is wound twice in the figure in the direction orthogonal to the bead wire 2. The bead core 1 is formed by forming the restraining portion 5.

  Such a bead core 1 is preferably wound at least twice at two or more positions in the circumferential direction of the wound annular body 3 as shown in the drawing.

  That is, by winding the steel wire 4 at two or more positions in the circumferential direction of the wound annular body 3, the shape retaining property of the bead core 1 can be effectively improved. By restricting at least twice, the binding force for the wound annular body 3 can be further increased.

  In addition, the diameter φ (mm) of the steel wire 4 is preferably 0 <φ ≦ 1, since the steel wire 4 can be easily and quickly wound around the wound annular body 3.

FIG. 3 is a front view showing another embodiment of the bead core of the present invention.
FIG. 3A shows a case in which four restraining portions 5 made of steel wire 4 are provided in the circumferential direction, and FIG. 3B shows an example in which eight restraining portions 5 are provided in the circumferential direction. FIG. 3 (c) shows a case where the restraint portion 5 is formed by spirally winding the steel wire 4 in the circumferential direction, and FIG. 3 (d) shows the steel wire 4 spirally in different winding directions. FIG. 3 (e) shows the case where the spiral winding shown in FIG. 3 (d) is tightly restricted.

  In the pneumatic tire in which such a bead core 1 is embedded in the bead portion, the shape retaining property of the bead core 1 is excellent, so that the rim assemblability is improved and the bead portion is prevented from being damaged during the rim assembling or running the tire. . Further, the movement of the bead wire 2 in the bead core 1 during or after the rim assembly is suppressed to improve the fitting property with the rim to prevent the tire from coming off the rim, and the safety is excellent.

  Next, a tire having a size of 11R225, in which a bead core having the structure shown in FIG. 2 and FIG. 3 (b) is set, was prototyped. In this case, the specifications of the bead core were changed as shown in Table 1. The shape retention was measured for each of the example tire and the comparative tire.

Here, for shape retention, each of the example tire and the comparative example tire was cut at 10 places on the circumference of the tire, and the shape collapse of the bead core was evaluated. The results are shown in Table 2.
In addition, the index value in a table | surface is calculated | required using the value of the comparative example tire as control, and shows that performance is so favorable that an index | exponent is large.

  From the results in Table 2, the shape of the example tires was suppressed from being lost compared to the comparative example tires.

It is a front view showing one embodiment of a bead core of the present invention. FIG. 2 is an enlarged cross-sectional view of the bead core of FIG. 1 at a restraining position. (A)-(e) is a front view which shows other embodiment of the bead core of this invention.

Explanation of symbols

1 Bead core 2 Bead wire 3 Winding ring 4 Steel wire 5 Restraint part

Claims (3)

  A steel wire that is formed by winding one or a plurality of bead wires in an annular shape, and plating at least one place in the circumferential direction of a wound annular body having a polygonal outer profile in cross section. A bead core that is restrained by winding in a direction perpendicular to the bead wire.   The bead core according to claim 1, wherein the steel wire is wound at least twice at two or more positions in the circumferential direction of the wound annular body.   The bead core according to claim 1, wherein a diameter φ (mm) of the steel wire is 0 <φ ≦ 1.

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