JP2019093676A - Annular rubber member - Google Patents

Abstract

To provide an annular rubber member in which a shape of a junction of each end face of a belt-like rubber member is not nonuniform, and a shape in a circumferential direction can be uniformized.SOLUTION: In an annular rubber member 10 including a junction 12 formed by butting together one end face e1 and the other end face e2 of a belt-like rubber member 11 in the circumferential direction, the belt-like rubber member 11 includes a projection part 13 provided on one end face e1 and a recessed part 14 provided on the other end face e2, and the projection part 13 is inserted into the recessed part 14.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an annular rubber member.

  The pneumatic tire is manufactured by bonding a tire component such as an inner liner, a sidewall, a bead, and a tread in an unvulcanized state to form a green tire, and vulcanizing and forming the green tire.

  The bead is composed of a bead core as a reinforcing material and a bead filler made of rubber having a substantially triangular cross section. The annular bead filler is formed by extruding a bead filler having a predetermined cross-sectional shape into a strip by an extruder, cutting the bead filler into a length corresponding to the circumferential length of the bead core, and then bonding the end portions together. However, when the end portions are stacked and bonded in the thickness direction, the thickness of the bonding portion locally increases and the shape becomes nonuniform, which may deteriorate the uniformity of the tire.

  Therefore, by thinning the start end and the end of the strip-shaped rubber member and laminating and bonding the thinned start and end, it is possible to prevent the thickness of the joint from locally increasing. It has been proposed to make the shape of the annular rubber member uniform in the circumferential direction (for example, Patent Documents 1 and 2 below).

  However, when forming an annular member such as a bead filler, it is difficult to overlap the end portions of the strip-like rubber members with high positional accuracy, so the shape of the joint becomes nonuniform, which may deteriorate the uniformity of the tire. .

JP 2009-61690 No. Unexamined-Japanese-Patent No. 2017-105077

  The present invention has been made in view of the above situation, and an object thereof is to provide an annular rubber member which can make the shape uniform in the circumferential direction without making the shape of the joint portion between the end faces of the strip rubber member uneven. It is.

  The annular rubber member of the present invention is an annular rubber member provided with a joint portion in which one end surface and the other end surface of the belt-shaped rubber member are butted in the circumferential direction, wherein the belt-shaped rubber member is a convex provided on the one end surface It has a shape part and a concave part provided in the above-mentioned other end side, and the above-mentioned convex part fits into the above-mentioned concave part.

  In a preferred aspect of the present invention, the convex shape and the concave shape may be provided up to the radially outer end of the belt-like rubber member.

  In another preferable aspect of the present invention, the convex shape and the concave shape may be terminated inward from the radially outer end of the rubber band member.

  In another preferred aspect of the present invention, an angle formed by the tip of the convex portion and the tangential direction at the radially inner end of the band-shaped rubber member may be an acute angle.

  According to the present embodiment, the shape of the joint portion between the end faces of the strip-shaped rubber members can be made uniform, and the shape can be made uniform in the circumferential direction.

BRIEF DESCRIPTION OF THE DRAWINGS The perspective view which shows the cross-sectional shape of a tire bead body provided with the annular | circular shaped rubber member which concerns on one Embodiment of this invention. The figure which looked at the tire bead body of FIG. 1 from the axial direction. FIG. 2 is a perspective view showing an end face of the annular rubber member of FIG. 1; The perspective view which shows the end surface of the annular | circular shaped rubber member which concerns on the example 1 of a change. The figure which looked at the end face of the annular rubber member concerning modification 2 from the direction of an axis. Sectional drawing which cut | disconnected the annular rubber member which concerns on the example 3 of a change in the circumferential direction.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  The annular rubber member 10 of the present embodiment is a bead filler having a substantially triangular cross section used in part of the tire bead 1. As shown in FIG. 1, the annular rubber member 10 has a predetermined length (height) h in the annular radial direction, and is thinner from the radially inner end 10a to the radially outer end 10b. The cross-sectional shape is substantially an annular disc having a substantially triangular shape.

  The annular rubber member 10 is pasted and laminated on the outer periphery of the bead reinforcing material 2 formed of an annularly shaped wire or the like, and constitutes a part of the tire bead body 1. The tire bead 1 is used by being embedded in a bead portion of a pneumatic tire or the like.

  Specifically, a strip-shaped rubber member 11 extruded with an approximately triangular shape in section and having a predetermined length h in the radial direction is wound around the outer peripheral surface of the annular bead reinforcement 2, and the periphery of the bead reinforcement 2 is Cut at a length corresponding to the length. Then, an annular rubber member 10 is formed on the outer periphery of the bead reinforcing material 2 by butting and joining one end surface e1 of the strip-shaped rubber member 11 generated by cutting and the other end surface e2. That is, the annular rubber member 10 includes the joint portion 12 formed by butting the one end face e1 and the other end face e2 of the band-like rubber member 11.

  In such an annular rubber member 10, at one end face e1 of the strip-shaped rubber member 11 constituting the joint portion 12, a convex portion 13 projecting in the circumferential direction is provided. The convex portion 13 is provided over the entire radial direction of the one end surface e1 from the radially inner end 10a of the strip-shaped rubber member 11 to the radially outer end (apex of cross-sectional triangular shape) 10b.

  Further, on the other end surface e2 of the strip-shaped rubber member 11, a concave portion 14 recessed in the circumferential direction is provided. Similar to the convex shaped portion 13, the concave shaped portion 14 is also provided over the entire radial direction of the one end surface e2 from the radially inner end 10 a of the strip-shaped rubber member 11 to the radially outer end 10 b.

  When the one end surface e1 and the other end surface e2 are butted and joined, the strip-shaped rubber member 11 has the convex portion 13 provided on the one end surface e1 fitted in the concave portion 14 provided on the other end surface e2 The e1 and e2 are butted to form the joint 12. At this time, since the convex portion 13 is guided by the inner wall surface of the concave portion 14, it is joined at a predetermined position of the concave portion 14.

  Since the joint portion 12 is formed by fitting the convex portion 13 into the concave portion 14, the joint portion 12 does not have a larger thickness than other portions, and has a uniform thickness in the circumferential direction. The annular rubber member 10 is formed.

  In the annular rubber member 10 of the present embodiment as described above, the convex portion 13 is provided on one end face e1 of the band-like rubber member 11, and the concave portion 14 to be fitted into the convex portion 13 is provided on the other end face e2. Therefore, the convex portion 13 is guided by the inner wall surface of the concave portion 14 and joined at a predetermined position of the concave portion 14. Therefore, the shape of the joint 12 between the end surfaces e1 and e2 of the strip-shaped rubber member is not uneven, and the shape can be uniform in the circumferential direction.

  Further, in the present embodiment, since the convex portion 13 and the concave portion 14 are provided from the radially outer end to the radially inner end of the strip-shaped rubber member 11, one end surface e1 and the other end surface e2 are butted. When bonding, the convex portion 13 is guided by the concave portion 14 in the entire radial direction of the strip-shaped rubber member 11, and the convex portion 13 can be joined to the predetermined position of the concave portion 14 more reliably. While being able to join, the contact area of the one end surface e1 and the other end surface e2 becomes large, and it can raise joint strength.

  The above embodiments are presented as examples and are not intended to limit the scope of the invention. This novel embodiment can be implemented in other various forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention.

(Modification 1)
In the above embodiment, the case where the convex portion 13 and the concave portion 14 are provided from the radially outer end to the radially inner end of the strip-shaped rubber member 11 has been described, but as illustrated in FIG. In the region from the radially inner end 10a to the substantially central portion in the radial direction, a convex portion 113 projecting in the circumferential direction is provided in a part of the radial direction of the one end surface e1 and the concave portion 114 depressed in the circumferential direction is the other end surface You may provide in a part of radial direction of e2.

  In such a case, the convex shape portion 113 and the concave shape portion 114 do not exist at the radial direction outer end of the annular rubber member 10 which becomes the apex of the triangular cross section, so the convex shape portions at the end surfaces e1 and e2 of the strip rubber member 11 113 and concave portion 114 can be easily formed.

  In addition, the other structure and the effect are the same as that of 1st Embodiment, and detailed description is abbreviate | omitted.

(Modification 2)
In the embodiment described above, the tip 13a (see FIG. 3) of the convex portion 13 is provided perpendicular to the tangential direction L (that is, parallel to the radial direction), but as illustrated in FIG. The convex portion 213 may be formed so that an angle θ between the tip end portion 213a of the portion 213 and the tangential direction L at the radially inner end 10a of the annular rubber member 10 is an acute angle. That is, the convex portion 213 is circumferentially longer as it goes from the radially outer end 10 b of the annular rubber member 10 to the radially inner end 10 a.

  Further, the concave portion 214 has a shape which is recessed in the circumferential direction as it goes from the radially outer end 10 b of the annular rubber member 10 to the radially inner end 10 a so that the convex portion 213 is fitted.

  In such a case, when the end face e1 and the other end face e2 of the strip-like rubber member 11 are butted and joined on the outer peripheral surface of the annular bead reinforcing material 2, the convex shape portion 213 becomes the bead reinforcement member 2 by the concave shape portion 214. The position of the strip-shaped rubber member 11 is easily fixed on the outer peripheral surface of the bead reinforcing member 2 by pressing, and the annular rubber member 10 can be firmly in close contact with the bead reinforcing member 2.

  In addition, the other structure and the effect are the same as that of 1st Embodiment, and detailed description is abbreviate | omitted.

(Modification 3)
In the embodiment described above, the case where the convex shaped portion 13 has a substantially triangular circumferential cross-sectional shape in which the tip portion 13a is disposed substantially at the center in the thickness direction of the strip-shaped rubber member 10 has been described. As shown in a), the tip end portion 313a of the convex shape portion 313 is disposed at a position closer to one side than the substantially central portion in the thickness direction of the strip-shaped rubber member 10, or as shown in FIG. The circumferential cross section of the shape portion 413 is provided in a semicircular shape, or as shown in FIG. 6C, the circumferential cross section of the convex shape portion 513 is provided in a W shape, and the concave portions 314, 414, 514 are provided. May be provided in a concave shape which is depressed in the circumferential direction in which the convex portions 313, 413, 513 are fitted.

  Even in such a case, the same effects as those of the first embodiment can be obtained. The other configuration is the same as that of the first embodiment, and the detailed description will be omitted.

DESCRIPTION OF SYMBOLS 1 ... tire bead body, 2 ... bead reinforcement, 10 ... annular annular rubber member, 10a ... radial direction inner end, 10b ... radial direction outer end, 11 ... strip-like rubber member, 12 ... joint part, 13 ... convex shape part, 14 ... recessed part

Claims (4)

In an annular rubber member provided with a joint portion in which one end surface and the other end surface of the strip-shaped rubber member are butted in the circumferential direction,
The annular rubber member, wherein the belt-like rubber member includes a convex portion provided on the one end surface and a concave portion provided on the other end surface, and the convex portion fits into the concave portion.   The ring-shaped rubber member according to claim 1, wherein the convex portion and the concave portion are provided up to the radially outer end of the band-shaped rubber member.   The ring-shaped rubber member according to claim 1, wherein the convex portion and the concave portion terminate inward from the radially outer end of the band-shaped rubber member.   The ring-shaped rubber member according to any one of claims 1 to 3, wherein an angle between a tip of the convex portion and a tangential direction at a radially inner end of the band-shaped rubber member is an acute angle.

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