JP2006239938A - Manufacturing method of tire reinforcing material and manufacturing method of pneumatic tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the uniformity of a tire at the time of molding vulcanization by achieving the uniformization of the rigidity in the joining part of a ply comprising a cord fabric. <P>SOLUTION: This manufacturing method of a tire reinforcing material comprises a process for preparing the tire fabric composed of warp yarns arranged in parallel to each other, a plurality of dummy yarns arranged in parallel to the warp yarns at both end parts in its width direction and weft yarns for keeping at least the warp yarns at a predetermined interval, a topping process for lining the tire fabric with a rubber to form the ply, a cutting process for cutting the ply into a predetermined length to form a ply piece, a joining part adjusting process for peeling the dummy yarns of both end parts of the ply piece to form the joining part and a joining process for mutually joining the joining part of the ply piece and the joining part of another ply piece to integrate both of them. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  TECHNICAL FIELD The present invention relates to a method for manufacturing a tire reinforcement made of a bamboo fabric and a method for manufacturing a pneumatic tire using the same, and in particular, at a joint portion at both ends of a ply of a reinforcement used for a tire carcass, chafer, bead reinforcement layer, and the like. This improves the dynamic uniformity during running of the pneumatic tire.

  The interwoven fabric is widely used as a tire reinforcing material. For example, in a carcass ply of a radial tire, the cords of the interwoven fabric warp are arranged in a direction perpendicular to the circumference of the tire. The manufacturing of a pneumatic tire having a radial structure generally includes the following steps.

  A ply is produced in which a weft fabric composed of a large number of warp yarns arranged in parallel and weft yarns arranged to prevent the warp yarns is rubberized in a topping process. The ply is cut into a predetermined length at a predetermined angle in the longitudinal direction of the warp to produce a ply piece. At the both ends in the width direction of the cut ply pieces, the plies are joined to each other by overlapping with the ends of the other ply pieces so that two to ten cords overlap each other. This joining is repeated a plurality of times to form a cylindrical carcass ply.

  After that, the carcass ply is combined with a reinforcing material such as a bead core to form a toroid, and further, a belt layer, a tread rubber, a sidewall rubber, etc. are laminated on the outer periphery of the toroid-like carcass, and then vulcanized to form a pneumatic tire. To manufacture.

  Conventionally, in the manufacturing process of tires, for example, to form a carcass ply by joining the cut ply pieces, a method in which the ends of a plurality of ply pieces are butted together and a plurality of ply pieces overlap each other There is a method of joining so as to form a part.

  In the former method, as shown in FIG. 4, the ply pieces 41 and 42 form a joint portion J by abutting the both end portions 41 </ b> J and 42 </ b> J. In this case, the overlapping part of the joint part of the ply piece can be eliminated. However, the warp yarns 40 at both ends of the ply piece are constrained to the inner side at the turned-up portion of the weft yarn. As a result, the meandering of the warp yarn 40 remains as it is at the joint portion of the formed carcass ply ply pieces, and when the tire is manufactured, its shape is maintained in the side wall portion, and the uniformity during running of the tire is impaired. It becomes.

  On the other hand, in the latter method, as shown in FIG. 5, both end portions of the ply pieces 51 and 52 are overlapped to form the joint portion 5J. In this case, the warp yarn 51a of the ply piece 51 and the warp yarn 52a of the ply piece 52 located at the joint portion 5J are configured to overlap each other. Here, since the number of cords in the joint portion 5J of the ply piece is larger than that in other portions of the ply, the elongation stress per cord is small, the thermal contraction is large, and the rigidity of the joint portion is further increased. Therefore, when the tire is molded and the internal pressure is filled, the joint portion expands less than the other portions of the ply, and as a result, a concave portion is generated in a portion corresponding to the joint portion of the sidewall portion. The shape of the part becomes non-uniform, and the uniformity during running is greatly impaired.

In order to solve such a problem, Patent Document 1 proposes a method of reducing the rigidity of the joint portion by using a special stretch cord for the warp (end portion) of the interwoven fabric. Patent Document 2 discloses that a low-shrinkage polyester cord is used for the ear portion of the interwoven fabric. Further, Patent Document 3 discloses a structure in which warp yarns of high elongation and normal warp yarns are alternately arranged on the ear portion of the weave fabric.
Japanese Utility Model Publication No. 4-14462 Japanese Examined Patent Publication No. 63-48723 Japanese Patent Publication No. 61-43457

  In the conventional method of forming the carcass ply by joining the both ends of the ply piece, the uniformity of the tire due to the meandering of the warp at the both ends in the width direction is impaired. On the other hand, in the method of forming the carcass ply by overlapping the both end portions of the ply piece to form the carcass ply, the rigidity at the joint portion of the ply piece is increased. As a result, when the tire is molded and vulcanized and filled with internal pressure, the side wall part appears as a concave part where the joint part of the ply piece does not expand sufficiently, and dynamic uniformity during tire rolling Will be reduced. The present invention solves such problems and provides a method for manufacturing a tire reinforcing material and a method for manufacturing a pneumatic tire excellent in dynamic uniformity.

  The present invention is composed of warp yarns arranged in parallel to each other, a plurality of dummy yarns arranged in parallel to the warp yarns at both ends in the width direction, and at least the weft yarns for maintaining the warp yarns at a predetermined interval. A step of preparing a bamboo fabric, a topping step of rubberizing the bamboo fabric to form a ply, a cutting step of cutting the ply into a predetermined length to form a ply piece, and both ends in the width direction of the ply piece A tire reinforcing material comprising a joining portion adjusting step of peeling a dummy yarn of a portion to form a joining portion, and a joining step of joining and integrating the joining portion of the ply piece and the joining portion of another ply piece together Is the method.

  It is preferable that the said joint part adjustment process is comprised by 3-50 dummy yarns of the edge part of a ply piece. The dummy yarn is preferably 105 to 130% of the diameter of the warp. The tire reinforcement is preferably applied to the carcass ply. And this invention is a manufacturing method of the pneumatic tire containing the manufacturing method of the said carcass ply.

  In the tire reinforcing material manufacturing method of the present invention, the warp yarns at both ends of the ply piece are constituted by a plurality of dummy yarns. Therefore, when joining the ply pieces to each other, the dummy yarn part is peeled off from the ply piece and joined together to avoid duplication of the joint part and eliminate the meandering of the warp at the joint part. Therefore, a uniform tire reinforcement can be obtained as a whole. As a result, when the tire is filled with the internal pressure after molding vulcanization, the generation of recesses in the sidewall portion can be further reduced and the dynamic uniformity can be improved.

  The present invention relates to a weft fabric composed of warp yarns arranged parallel to each other, a plurality of dummy yarns arranged in parallel to the warp yarns at both ends thereof, and a weft yarn for maintaining at least the warp yarns at a predetermined interval. Preparing a ply by rubberizing the comb fabric, cutting step for cutting the ply into a predetermined length to form a ply piece, and dummy yarns at both ends of the ply piece It is the manufacturing method of the tire reinforcement material which consists of the joining part adjustment process which peels and forms a junction part, and the joining process which mutually joins and integrates the junction part of the said ply piece, and the junction part of another ply piece.

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

<Wedding fabric>
FIG. 1 is a schematic view of a ply 1 obtained by rubberizing a comb fabric after a topping process. The ply 1 is formed by embedding the interwoven fabric 3 in the rubber composition 2. The weave fabric 3 is woven with wefts 5 spaced apart in the longitudinal direction of the warp yarns in order to keep the warp yarns 4 for reinforcing the tires in parallel and keeping the warp yarns constant. Here, a plurality of dummy yarns 4a are arranged at both ends of the weave fabric. In FIG. 1, three dummy yarns 4a are shown.

  Here, since the dummy yarn 4a does not need to maintain the strength as a tire reinforcing material, it is not necessary to use the same material as the warp 4 in the central portion of the ply 1. As the dummy yarn, for example, a material having inferior strength such as polypropylene, polyethylene, polyurethane, in addition to polyester, nylon, and rayon can be used. As the dummy yarn, a filament or a cord obtained by twisting a plurality of filaments can be used. Furthermore, the diameter of the dummy yarn is larger than the diameter of the warp yarn at the center of the ply, preferably in the range of 105 to 130%, particularly 110 to 120%. By adjusting the size of the dummy yarn within the above range, the dummy yarn portion can be visually discriminated and can be easily peeled off from both ends of the ply piece.

  Further, the elongation of the dummy yarn is preferably substantially the same as the warp yarn at the central portion of the ply in order to make it easy to peel off the dummy yarn at both ends of the ply piece. However, as long as the effect of the present invention is achieved, a highly stretched filament or cord can be used at the end of the ply piece.

  The warp 4 is made of a material widely used as a tire cord. The warp 4 is not melted by heat during vulcanization molding, and further by heat such as a heating process of the adhesion treatment, and reinforces the pneumatic tire by being arranged inside the vulcanized pneumatic tire. The warps 4 are arranged more densely than the wefts 5, but the density can be arbitrarily set according to the tire used. The warp 4 can be a tire cord made of polyethylene terephthalate, nylon, rayon, vinylon (particularly high-strength vinylon), or aramid. The warp yarn is usually in the range of 1260 denier to 6000 denier, and the weft yarn is usually in the range of 180 denier to 270 denier.

  The wefts 5 are woven so as to pass through the upper and lower sides of the adjacent warp yarns 4 in a direction substantially perpendicular to the longitudinal direction of the warp yarns 4 and as shown in FIG. Is shown. The wefts 5 serve to maintain a uniform warp pitch of the warps 4 arranged in a large number on the plane in this way. As shown in FIG. 1, the weft 5 was woven by turning the wefts 5 continuously at the left and right ears of the woven fabric 3, as shown in FIG. 1. Various other weaving methods can be employed.

  The weft 5 may be a yarn made of a heat-resistant material having substantially no melting point, such as cotton or flat rayon, but may also be a low melting point material having a melting point of 110 to 150 ° C. In this case, it is possible to prevent a tatami mat phenomenon in which the weft 5 melts under the action of heat and tension during tire vulcanization and the warp 4 is waved. That is, when the weft has a melting point of 110 to 150 ° C. under heat and pressure under the condition of the vulcanization temperature (about 140 to 180 ° C.) of the tire, the binding force of the warp can be reduced during vulcanization.

  Examples of the weft material having a low melting point include high-density polyethylene, vinyl chloride / vinyl acetate copolymer, ethylene / vinyl acetate copolymer, terpolymer polyamide, quaternary copolymer polyamide, and multicomponent copolymer. There are polymer polyamides and the like.

  Here, the wefts 5 are woven so as to keep the warp yarns at regular intervals and prevent them from being separated from each other. Then, the weft 5 is folded back by a dummy yarn 4 a located at the end of the interwoven fabric 3. Therefore, the dummy yarn 4a at the end located at the folded-back portion 5a of the weft is constrained to the inner side of the interwoven fabric, and as a result, it tends to have a meandering shape.

<Topping process>
In the topping process of the present invention, a ply is produced by applying an adhesive treatment to the comb fabric and embedding it in a rubber composition. FIG. 1 shows a schematic view of a ply used in the present invention. In FIG. 1, the ply 1 has a rubber composition 2 in which an interwoven fabric 3 is embedded. Here, in the weft fabric, weft yarns 5 are arranged on the warp yarns 4 and the dummy yarns 4a arranged parallel to the longitudinal direction at regular intervals in the longitudinal direction and in a direction substantially perpendicular to the warp yarns. And the embedment density of the warp in the ply is set in the range of 30/5 cm to 50/5 cm. Further, the burying density of the wefts in the ply is set in a range of 2 / 5cm to 6/5 / 5cm.

  The interwoven fabric is subjected to an adhesive treatment prior to being embedded in the rubber composition. The adhesion treatment includes a dipping process in which the braided fabric is dipped in an adhesion treatment liquid, and a heating process in which the warp yarn is heated (baked) in a state where a certain amount of tension is applied after the dipping process. The rubber adhesion of the tire weave fabric is improved.

  The adhesion treatment includes a dipping step of immersing the tire reinforcing braid fabric in an adhesion treatment solution in which various chemicals are added to, for example, an initial condensate of resorcin-formalin and vinylpyridine latex or a mixture of vinylpyridine latex and SBR latex. And a heating step of heating the warp in a state where a certain amount of tension is applied after the dipping step. After the bonding treatment, the soaking fabric is topped with unvulcanized rubber on the top and bottom of the fabric to prepare a so-called ply.

<Cutting process>
The ply shown in FIG. 1, that is, the ply 1 in which the rubber composition 2 is topped on the interwoven fabric 3 is cut at a predetermined angle in the longitudinal direction of the warp 4. For example, when used for a carcass of a radial tire, a ply piece is manufactured by cutting at a constant interval in a direction substantially perpendicular to the warp direction, that is, substantially in the same direction as the weft 5 arrangement direction. In the carcass ply of the radial tire, the cut width of the ply piece corresponds to the toroidal cross-sectional length of the carcass extending over both bead portions, and the warp 4 is arranged at right angles (radial direction) to the tire circumferential direction. The ply can be arbitrarily set with a cutting width and a cutting angle according to the use of the ply piece to be used.

<Joint adjustment process>
A method of joining the ply pieces will be described with reference to FIG. FIG. 2A is a schematic view showing a state where the end 21J of the ply piece 21 is peeled from the ply piece 21. FIG. Here, the dummy yarns 25J arranged at the joining portions 21J located at both ends of the ply piece 21 are peeled off from the ply pieces before the ply pieces are mutually joined. The dummy yarn 4a at the end of the interwoven fabric is restrained inside the interwoven fabric at the position of the folded portion 5a of the weft 5. Therefore, the warp 40 located at the end of the ply has a shape meandering in the longitudinal direction, and when this ply is directly attached and joined, the joint 4J becomes a meandering shape as shown in FIG.

  The present invention removes the meandering dummy yarn portion at the end of the ply piece to form a uniform joint portion of the ply piece by peeling off the end of the ply piece where the dummy yarn located at the end of the ply is disposed. Is done. Here, a plurality of dummy yarns arranged at the end of the ply piece are arranged, preferably 5 to 50. When the number of the dummy yarns is one, the meandering of the warp at the end of the ply cannot be eliminated. On the other hand, when the number exceeds 50, there is an effect of eliminating the meandering of the warp, but the material cost associated with the removal of the warp is wasted It will be. Then, the ply pieces are joined to each other so that there is no overlap between the joint portions of the ply pieces. A cross section of the ply in a joined state is shown in FIG.

  In the present invention, in order to make it easy to peel the dummy yarn from the ply piece, the folded end portions of the weft yarns at both ends of the interwoven fabric can be cut.

<Manufacture of pneumatic tires>
A ply formed by joining a plurality of the above plies into a cylindrical shape can be used for a carcass ply of a pneumatic tire. FIG. 3 shows the right half of the sectional view of the pneumatic tire T. The carcass ply 31 is folded and locked around the bead core 35 of the bead portion 34 from the tread portion 32 through the sidewall portion 33. Ply is arranged. A belt layer 36 composed of two plies is disposed at an angle of 5 ° to 45 ° in the tire circumferential direction at the crown portion of the tire. FIG. 3 shows a pneumatic tire having a radial structure, and the warp yarns of the carcass ply are arranged so as to extend radially (perpendicular to the tire circumferential direction) in the radial direction inside the tire.

  The pneumatic tire T is manufactured by using this carcass ply to combine a bead core, a belt layer, tread rubber, etc. with a normal molding method to form a raw tire cover and vulcanize it with a vulcanization mold. Is done.

  In addition, in this invention, a reinforcing material can be employ | adopted for a chiefer, a bead reinforcement layer, and a side part reinforcement layer other than a tire carcass.

<Creating a weave fabric / ply>
A warp woven fabric of 1670 dtex / 2 in polyester, polyester as a dummy yarn in the specifications shown in Table 1, and a weft woven fabric made of 250 dtex in polyester as a weft was used. The embedding density of the warp yarn in the ply is 50 / 5cm.

  A warp woven fabric made of 1670 dtex / 2 of polyester, 1900.dtex / 2 of polyester as dummy yarn, and 250 dtex of polyester as weft yarn was used. The embedding density of the warp yarns in the ply was changed as shown in Table 2.

  This tinted fabric was subjected to an adhesive treatment in order to improve the adhesion to rubber. This adhesion treatment is performed by immersing in an adhesion treatment solution in which various chemicals are added to a mixture of resorcin-formalin initial condensate, vinylpyridine latex and SBR latex, and applying a certain tension to the warp. It was. Thereafter, unvulcanized rubber was topped on the upper and lower sides of the woven fabric, and a tire reinforcement was prepared as a ply.

<Creation and evaluation of ply pieces>
The plies are cut at regular intervals in the longitudinal direction. A ply piece for a carcass ply of a radial tire was produced. The peeling section of the ply piece after peeling the dummy yarn at the end of the ply piece was visually observed and evaluated. The evaluation is evaluated with 1 to 5 points, and 5 points are the most excellent.

  In Table 1, in Experiment No. 3 in which the diameter of the dummy yarn was 115% of the diameter of the warp yarn, it was recognized that the peeling cross section of the ply piece was uniform.

  In Table 2, it was recognized that the peeling cross section of the ply piece of Experiment No. 4 where the number of dummy warps is 30 and Experiment No. 4 is 10 is uniform.

  In the tire reinforcing material based on the manufacturing method of the present invention, the joint portions of the ply pieces are formed uniformly. As a result, the pneumatic tire using this for the carcass ply does not have a meandering or overlapping portion of the joint portion of the ply. Appearance is improved and product value can be increased.

It is the schematic of the ply which consists of an interwoven fabric. (A) is the schematic which shows the peeling state of the ply of this invention, (B) is sectional drawing of the state which joined the ply piece. The right half of a sectional view of a pneumatic radial tire is shown. It is the schematic which shows the joining state of the conventional ply. It is the schematic which shows the joining state of the conventional ply.

Explanation of symbols

  1 ply, 2 rubber composition, 3 weave fabric, 4 warp yarn, 4a dummy yarn, 5 weft yarn, 5a weft return portion.

Claims (5)

Preparation of a weave fabric composed of warps arranged in parallel to each other, a plurality of dummy yarns arranged in parallel to the warps at both ends in the width direction, and at least wefts for maintaining the warp at a predetermined interval And a process of
A topping step of rubberizing the interwoven fabric to form a ply;
A cutting step of cutting the ply into a predetermined length to form a ply piece;
A joint adjustment step of peeling the dummy yarns at both ends in the width direction of the ply piece to form a joint; and
A method for manufacturing a tire reinforcing material, comprising a joining step in which a joint portion of the ply piece and a joint portion of another ply piece are joined together and integrated.   The manufacturing method according to claim 1, wherein the bonding portion adjusting step includes 5 to 50 dummy yarns at an end portion of the ply piece.   The manufacturing method according to claim 1, wherein the dummy yarn is 105 to 130% of the diameter of the warp.   The manufacturing method according to claim 1, wherein the tire reinforcing material is a carcass ply.   A method for manufacturing a pneumatic tire, comprising the method for manufacturing a carcass ply according to claim 4.

Images