JP2006159691A - Method for molding pneumatic tire and winding structure of ribbon-like strip used in it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable the effective offset of force in the meridian line direction generated in a reinforcing layer by surely giving a prescribed phase difference with more than one cord made a unit to the bent cords of the reinforcing layer and to effectively suppress a decline in the constitution efficiency of the reinforcing layer and accordingly the molding efficiency of a green tire. <P>SOLUTION: When a pneumatic tire in which the reinforcing layer 8 mainly comprising the bent cords 5 extending in the circumferential direction while waving is set on the peripheral side of the crown region of a carcass 2 extending toroidally between both bead cores 4 is molded, the reinforcing layer 8 is constituted by winding even-numbered ribbon-like strips 6 and 7 obtained by coating the bent cords 5 arranged in parallel in the same phase with rubber spirally at the same time in a relative posture with a phase difference formed in the bent cords 5. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for molding a pneumatic tire suitable for use as a tire for a large vehicle filled with a high internal pressure and used under a high load, and a ribbon-shaped strip winding structure used for the method, in particular. The inner tire is filled with one or more reinforcing layers mainly composed of a detouring cord that extends in the circumferential direction in a wavy manner in the tire width direction on the outer peripheral side of the crown region of the carcass. In addition, the concave and convex deformation that occurs on the side portion of the tire due to the expansion and deformation of the detour cord due to the high-speed rotation of the tire, etc. is advantageously suppressed to prevent deterioration of the appearance of the tire and increase the production efficiency of the tire Propose technology.

  In the case of a product tire provided with a reinforcing layer, as a conventional technique for suppressing the occurrence of uneven corrugation phenomenon on the side portion when the phase of the detour cord is aligned in the tire width direction, for example, the prior application of the applicant Japanese Laid-Open Patent Publication No. 4-328003 related to the above proposal.

This tire is disposed between a carcass layer and a belt layer, and is internally reinforced with a plurality of substantially identical reinforcing elements extending in parallel with the tire equatorial plane and bent in a wave shape. Comprising a layer, wherein the phases of a plurality of reinforcing elements among the reinforcing elements embedded in the reinforcing layer are different from the phases of the other reinforcing elements, according to this, When the tire is filled with internal pressure or when the tire is driven at a high speed, each reinforcing element expands and deforms and generates a force in the direction of reversing every half wavelength. Due to the difference in phase with respect to the other reinforcing elements, the force generated by the plurality of reinforcing elements is distributed or offset mutually from the force and direction or magnitude generated by the other reinforcing elements. The amount of undulation in the layer is reduced Irregularities in the outer surface of the sidewall portion is to be suppressed.
JP-A-4-328003

  However, in accordance with this prior art, one reinforcing element is provided on the assumption that the remainder of the bending wavelength of the reinforcing element bent in a wave shape is not divisible when it is taken as the divisor of the circumference of the molding drum on which it is wound. Alternatively, when a reinforcing layer is formed by spirally winding a ribbon-like body in which a small number of pieces are covered with rubber around the forming drum, the first is adjacent to each other or every other plurality on the forming drum. The phase difference between the reinforcing element portions that are positioned as expected, in other words, the force in the tire meridian direction generated due to the extension deformation of each reinforcing element There is no guarantee about offsetting within, and secondly, one of the narrow ribbons is spirally wound into one or more layers over the entire width of the reinforcing layer. Hit Tact time becomes considerably longer, raw type efficiency of green tire there is a problem such as that naturally lower.

  The present invention has been made to solve such problems of the prior art, and the object of the present invention is to provide a plurality of cords as a detour cord of a configured reinforcing layer. The phase difference as expected can be reliably applied to effectively cancel the meridional force generated in the reinforcing layer, and the component efficiency of the reinforcing layer, and thus the molding efficiency of the raw tire It is an object of the present invention to provide a method for molding a pneumatic tire capable of effectively suppressing a decrease in the above and a ribbon-shaped strip winding structure used therefor.

  The pneumatic tire molding method according to the present invention includes a plurality of usually the same wavelength and the same amplitude, which are continuously wound in the circumferential direction on the outer peripheral side of the crown region of the carcass extending toroidally between both bead cores. Consisting of one or more reinforcing layers mainly composed of a detour cord of a book and a plurality of linearly extending belt cords, two or more belt layers in which belt cords cross each other are arranged in sequence. When molding a pneumatic tire, the reinforcing layer is formed of an even number of ribbon-shaped strips having a predetermined width formed by applying a rubber coating to a plurality of detour cords arranged in parallel in the same phase. It is configured by winding in a spiral at the same time in a relative posture with a phase attached to the cord.

  Here, the term “wavyly undulate” refers to any one of various extending modes that are continuously curved and bent in a form approximate to them, in addition to a sine wave shape, a rectangular wave shape, a triangular wave shape, and the like. Shall.

By the way, the configuration of such a reinforcing layer is such that an even number of ribbon-like strips are formed on a belt-tread molding drum, or on a core having an outer surface shape corresponding to, for example, an inner shape of a product tire, or a tire molding drum. On the carcass material formed in the toroidal shape above, it can be carried out by winding it spirally in the axial direction.
Preferably, the phase difference of the circumflex code is in the range of 90 to 270 °.

  Further, the ribbon-shaped strip winding structure used in the molding of a pneumatic tire according to the present invention has a rubber coating applied in a straight line to a plurality of detour cords that are arranged in parallel at the same phase and extend in a wavy shape. An even number of ribbon-shaped strips having a predetermined width within a range of 5 to 30 mm, for example, are placed on a common reel with a phase difference in a detour cord, via a partition or through They are wound adjacent to each other.

  By the way, in such a wound structure, each of the even number of ribbon-like strips is formed by simultaneous rubber coating on the detour cords for the respective strips arranged with or without phase difference. In this case, in particular, when a plurality of ribbon-shaped strips are formed by rubber coating without giving a phase difference to each other, the detour cords for each strip are formed. When each of the ribbon-shaped strips wound is wound on one reel, it is preferable to give a required phase difference to the respective detour cords of the ribbon-shaped strips.

  In the molding method of the present invention, for example, two ribbon-shaped strips having a predetermined width within a range of 5 to 30 mm, for example, are phase-difference to the detour cord, preferably within a range of 90 to 270 °, particularly 180 ° First, the phase difference of the detour cord between the strips can always be set to a predetermined value by forming the reinforcing layer by spirally winding in a relative posture with As a result, due to the extension deformation of the detour cord, the meridional forces generated especially at the peak and valley portions thereof are effectively offset by the strips adjacent to each other.

  In this case, when the phase difference between the adjacent ribbon-shaped strips is 180 °, that is, ½ wavelength, the generated meridian force is applied to the adjacent portion in the tire width direction. Can be offset more directly and more effectively.

  Secondly, compared to the conventional technique in which one ribbon-shaped strip having a predetermined width is spirally wound by winding an even number of ribbon-shaped strips at the same time, the structural efficiency of the reinforcing layer, and thus the raw tire The molding efficiency can be greatly improved.

  Here, for example, when two ribbon-like strips are spirally wound on a belt-tread molding drum to form a required reinforcing layer, it is laminated and molded integrally with the belt layer material and the tread rubber. Therefore, it is possible to set them all on the toroidal carcass material at the same time and attach them to the carcass material. For example, work such as construction of the reinforcing layer and carcass band formation. The efficiency of green tire molding can be improved more effectively, and the unfolded cord of the reinforcing layer is formed in a toroidal shape with unexpected expansion deformation associated with green tire molding. It can be sufficiently suppressed by setting and sticking it onto the carcass material.

  And such an unexpected extension deformation of the detour cord is an even number on a rigid core or a carcass material previously formed in a toroidal shape on a tire molding drum having an outer surface shape corresponding to the inner surface shape of the product tire. In the case where the reinforcing layer is formed by directly winding the ribbon-like strip of the book, it can be further advantageously suppressed.

  Further, in the wound structure of the present invention, each of the even number of ribbon-shaped strips wound in advance in a state where the respective detour cords have a phase difference on a common reel is formed into a green tire. When the strips are fed out in synchronization with each other, the required reinforcing layer can be formed in a state in which the strips are surely provided with the phase difference as expected for the detour cord.

  In other words, when each of the even number of ribbon-like strips is fed out from separate reels, it is difficult to reliably give the expected phase difference to the respective detour codes of each slip. This is particularly true when, for example, when a specific strip is stretched and deformed before its spiral winding, due to relative fluctuations in the tension condition of each strip, etc. Serious.

  And in such a winding structure, when each ribbon-like strip wound up on one reel is formed by simultaneous rubber covering with respect to each detour cord with or without phase difference between each other In addition to increasing the formation efficiency of the ribbon-like strip, each ribbon-like strip is formed under the same rolling conditions, and the wavelength and amplitude of the respective detour cords embedded in them are made equal to each other. Can be maintained.

  Here, in the case where rubber coating is simultaneously performed without giving a phase difference to each detouring cord for each ribbon-shaped strip, each detouring cord is taken up when winding those strips on one reel. In order to secure a predetermined phase difference on the reel, it is necessary to give a required phase difference to each other.

  FIG. 1 is a cross-sectional perspective view in the width direction illustrating the molding method according to the present invention with respect to the steps of forming the reinforcing layer, and FIG. 2 is a partial view of a half of a green tire molded according to the method according to the present invention. It is a perspective view which shows as a cross section.

  In the figure, first, at least one carcass material 2 having a radial structure, for example, on the outer surface of the rigid core 1 having an outer surface shape corresponding to the inner surface shape of the product tire and capable of being disassembled and assembled, Many are arranged via the inner liner material 3, whereby the carcass material 2 is placed between the bead cores 4 arranged at both ends of the rigid core 1 and adjacent to the radially inner end portion thereof. Extend to toroidal.

  In addition, here, the respective side portions of the carcass material 2 are wound around the bead core 4 from the inner side to the outer side in the radial direction to restrain the carcass cord and thus the carcass material 2 from being pulled out.

  In addition, on the outer peripheral side of the crown region of the carcass material 2, one or more wave reinforcing layers mainly composed of a plurality of detouring cords that undulate and extend in the circumferential direction have the same wavelength and amplitude. In addition, in this figure, a plurality of, for example, four to ten detour cords 5 arranged in parallel at the same phase are covered with rubber, for example, a straight ribbon-like strip having a predetermined width within a range of 5 to 30 mm. An even number, in the figure two strips 6, 7, on each detouring cord 5 between the strips under the rotation of the rigid core 1, preferably in the range of 90-270 °, more preferably as shown, Relative posture with a phase difference of 180 °, spiraling from one side to the other side of the crown area at the same time without gaps or at intervals, or by overlapping a part of the width Then, a further reinforcing layer 8 having a required width is formed.

  In this case, the number of reinforcing layers can be increased as required by repeating the spiral winding of the two strips 6 and 7 in a similar manner thereafter. Can be performed.

  After forming the required number of layers as described above, one reinforcing layer 8 in the figure, a plurality of belt cords 9 extending linearly on the outer peripheral side of the reinforcing layer 8 as shown in FIG. 10 and the belt cords 9 and 10 between the layers extend, for example, symmetrically with respect to the tire equatorial plane, and each of the two layers of belt layer materials 11 and 12 are arranged with a required width. In addition, other necessary reinforcing members (not shown) are also disposed together, and after all the reinforcing members are disposed, the tread rubber 13 is disposed on the outer peripheral side of the belt layer materials 11 and 12, and the rigid core 1 is disposed. A side tire 14 is disposed in each of the regions corresponding to the side regions, thereby forming a required tire.

  When the green tire is molded in this way, the respective detour cords 5 in the respective ribbon-like strips 6 and 7 are still in the product tire after vulcanization molding to the green tire as expected. Therefore, even if a force directed in the meridian direction of the tire is generated based on the extension deformation of each detour cord 5 due to the diameter expansion deformation of the product tire, these forces are Therefore, the occurrence of surface irregularities on the tire side portion due to the deformation of the carcass can be effectively suppressed.

  Further, here, by forming an even number of ribbon-like strips 6 and 7 at the same time to form a reinforcing layer having a required width, the molding efficiency of the green tire can be greatly improved as compared with the prior art.

  1 and 2, the reinforcing layer 8 is formed on the outer peripheral side of the crown region of the carcass material 2 on the rigid core 1, but instead of using the rigid core 1, a tire molding drum is used. Also on the carcass material formed in a toroidal shape by a shaping bladder, a mechanical shaping mechanism or the like, the reinforcing layer can be configured in the same manner as described above.

  In addition, the reinforcing layer can be configured by simultaneously winding an even number of ribbon-like strips spirally on the belt-tread molding drum that forms a cylindrical shape as a whole prior to the formation of the belt layer material. In this case, the reinforcing layer having the required number of layers is integrated with the belt layer material and the tread rubber that are sequentially wound and laminated on the outer peripheral side thereof, and then the toroidal shape on the tire molding drum. It is transferred to the outer peripheral side of the carcass material to be formed, and is attached to the crown area of the carcass material there.

  In any of these cases, an even number of ribbon-like strips that are mutually phase-diffused are wound spirally at the same time to form a reinforcing layer. The force generated due to the extension deformation of the detour cord in the product tire can be effectively canceled, and the molding efficiency of the green tire can be advantageously improved.

FIG. 3 is a schematic perspective view illustrating a ribbon-shaped strip winding structure suitable for use in forming a green tire as described above.
This is similar to the case of the ribbon-like strips 6 and 7 described above. An even number of ribbon-like strips, with two rubber strips 23 and 24 in the figure, formed by releasing a rubber coating in a straight shape, are connected to the respective detour cords 21 and 22, for example, a phase difference within a range of 90 ° to 270 °, Then, it is wound on a common reel 25 in a relative posture with a phase difference of 180 °, that is, ½ wavelength, adjacent to each other via a partition 26, for example.

  According to such a wound structure, when the reinforcing layer is configured, the two reinforcing strips 23 and 24 are simultaneously fed out so that the required reinforcing layer as described above can be used as the detour cords 21 and 22. The predetermined phase difference can be simply configured while accurately maintaining it.

  By the way, for such a winding structure, when forming a ribbon-like strip formed by applying a rubber coating to a predetermined number of detour cords by an insulation method, a calendar method, etc., for example, FIG. As shown by way of example in the case of using a semi-hot calendar system, the detour cords 21 and 22 that are arranged in parallel with each other in the same phase and are fed out at a constant speed are fed through a sheet calendar roll 31. The rubber sheet 32 is simultaneously covered with a rubber with a pressure roll 33, whereby two ribbon-like strips 23, 24 wound adjacently on the reel 25 can be simultaneously formed. The formation efficiency of the strips 23 and 24 is increased and the formation conditions of the strips 23 and 24 are Te is preferably both strip itself in order to be sufficiently uniform.

  In this case, a ribbon-like strip wound on one or more other reels can also be formed at the same time, which can further increase the strip forming efficiency and improve the quality between the strips. Variation can be removed more effectively.

  Here, when the strips 23 and 24 are formed with the respective detour cords 21 and 22 in the same phase, the necessary positions are placed on the detour cords 21 and 22 under the winding posture on the reel 25. In order to give the phase difference, it is necessary to provide a path difference corresponding to the required phase difference in the movement path of the strips 23 and 24 until reaching the reel 25. As shown in the figure, the traveling path of the strip 23 to the reel 25 is made longer by a predetermined amount than that of the strip 24 by the relative arrangement of the pulleys 34 and 35, whereby the respective detour cords 21 and 22 are arranged. The required phase difference is ensured on the reel 25.

  On the other hand, when the detour cords 21 and 22 are passed through the crimping roll 33 in a state where a predetermined phase difference is given in advance, the respective cords in the formed strips 23 and 24 are provided. 21 and 22 also have a predetermined phase difference, so that both of them are wound on the reel 25 through a mutually equivalent path, and the respective detour cords of the strips 23 and 24 adjacent to each other. 21 and 22 can maintain the phase difference in advance.

  The same applies to the case where two or more even-numbered ribbon-like strips are simultaneously covered with the pressure roller 33.

It is a cross-sectional perspective view of the width direction which illustrates the shaping | molding method of this invention about the structure process of a reinforcement layer. It is a perspective view which shows the half part of the green tire shape | molded according to this invention as a cross section. It is a rough-line perspective view which illustrates the winding structure of a ribbon-shaped strip. It is a rough-line perspective view which illustrates the formation aspect of a ribbon-shaped strip.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rigid core 2 Carcass material 3 Inner liner material 4 Bead core 5, 21, 22 Detour cord 7, 8, 23, 24 Ribbon-shaped strip 8 Reinforcement layer 9, 10 Belt cord 11, 12 Belt layer material 13 Tread rubber 14 Side rubber 25 Reel 26 Partition 31 Sheet calendar roll 32 Rubber sheet 33 Crimp roll 34, 35 Pulley

Claims (6)

One or more reinforcing layers mainly composed of a plurality of detouring cords extending in the circumferential direction in the circumferential direction on the outer circumference side of the crown region of the carcass extending toroidally between both bead cores, and a plurality of belt cords extending linearly In forming a pneumatic tire comprising two or more layers of belts in which belt cords intersect each other between layers, in sequence,
An even number of ribbon-shaped strips formed by applying rubber coating to a plurality of curved cords arranged in parallel at the same phase in the reinforcing layer are simultaneously spirally wound in a relative posture with a phase difference between the curved cords. A method for molding a pneumatic tire constituted by the above.   The method for molding a pneumatic tire according to claim 1, wherein an even number of ribbon-like strips are spirally wound in the axial direction on a belt-tread molding drum or a carcass material formed in a toroidal shape.   The method for molding a pneumatic tire according to claim 1 or 2, wherein a phase difference of the detour cord is in a range of 90 to 270 °.   Commonly arranged in a relative orientation with a phase difference on the detour cords, with a plurality of detour cords arranged in parallel with the same phase difference and an even number of ribbon-like strips with a rubber coating applied straightly. A wound structure of a ribbon-like strip used for molding a pneumatic tire, which is wound on one reel adjacent to each other.   The ribbon-shaped strip winding structure used for molding a pneumatic tire according to claim 4, wherein each ribbon-shaped strip is formed by simultaneous rubber coating on the detour cord.   The pneumatic tire according to claim 4 or 5, wherein a phase difference is provided to each detouring cord of the formed ribbon-shaped strip when winding an even number of ribbon-shaped strips on one reel. Ribbon strip winding structure used.

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