JP2009292000A - Method of producing pneumatic tire and apparatus therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To uniformize amplitude (a) of a corrugated steel cord 32 in the whole of a cord reinforced layer 30, and to efficiently form the cord reinforced layer 30 while facilitating control. <P>SOLUTION: The cord reinforced layer 30 is molded by winding the corrugated steel cord 32 with the amplitude (a) gradually increasing, around a cylindrical molding drum 35 for several times as it is, and the amplitude (a) of the corrugated steel cord 32 in the cord reinforced layer 30 is increased as it separates axially from a set point P of a bead core 12. Thus, when an unvulcanized tire including the cord reinforced layer 30 is deformed approximately toroidally, the decrease and increase of the amplitude of the corrugated steel cord 32 cancel with each other to uniformize the amplitude (a) and facilitates control in winding to increase the work efficiency. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

    The present invention relates to a method and an apparatus for manufacturing a pneumatic tire in which a cord reinforcing layer of a corrugated steel cord is disposed between a bead portion and a shoulder portion.

    As a conventional pneumatic tire, in order to improve bead durability by suppressing separation at the folded end of the carcass layer, for example, as described in Patent Document 1, a portion between the bead portion and the shoulder portion is used. Specifically, here, there is known a structure in which a cord reinforcing layer (wire chafer) is disposed so as to overlap the folded portion of the carcass layer.

  Such a cord reinforcing layer is wound in a spiral shape while bending a rubber-coated single wire steel cord into a wave shape having substantially the same amplitude and the same wavelength directly outside the folded portion of the carcass layer having a substantially toroidal shape. However, when forming the cord reinforcement layer in this way, the steel cord must be guided along a complicated curved curve, so the control during winding is complicated. At the same time, there is a problem that the work efficiency is lowered.

  In order to solve such a problem, for example, a wavy steel cord bent into a wavy shape having substantially the same amplitude and the same wavelength is wound around a cylindrical forming drum as described in Patent Document 2 a plurality of times. A cylindrical cord reinforcing layer is formed, and a carcass ply or the like is wound around the forming drum to form a cylindrical carcass layer. On the other hand, bead cores are respectively set at set positions outside both axial ends of the carcass layer. It is conceivable to form a cylindrical tire intermediate.

JP 2006-160053 A Japanese Patent Laid-Open No. 11-309789

    However, after the tire intermediate body thus formed is bulged and deformed in a substantially toroidal shape, and a belt layer and a tread are pasted on the outer side of the tire intermediate body to form an unvulcanized tire, When a vulcanized tire is vulcanized to form a pneumatic tire, the cord reinforcement layer is greatly stretched in the circumferential direction as the cord reinforcement layer is separated from the bead core when deformed into a substantially toroidal shape. As the wavy steel cords constituting the layers are separated from the bead core, the amplitude becomes smaller, while the wavelength becomes longer. As a result, the amplitude and wavelength of the corrugated steel cord are considerably uneven when viewed from the entire cord reinforcement layer, particularly in the radial direction, and it is impossible to sufficiently improve the above-described bead durability. .

  The present invention provides a pneumatic tire manufacturing method and apparatus capable of forming a cord reinforcement layer with high efficiency while being easy to control, and capable of making the amplitude of the corrugated steel cord uniform throughout the cord reinforcement layer. The purpose is to provide.

    The purpose of this is as follows. First, a carcass layer extending in a toroidal shape with bead cores set at both ends and a portion between the bead portion and the shoulder portion, and extending in the circumferential direction and bent in a wave shape. A method of manufacturing a pneumatic tire having a cord reinforcing layer having a corrugated steel cord and a tread disposed at least radially outward of the carcass layer, wherein a linearly corded steel cord is bent into a corrugated shape and the amplitude is long. Forming a corrugated steel cord that gradually changes in the direction, winding a carcass ply around a cylindrical forming drum to form a cylindrical carcass layer, and forming a bead core at a set position outside both axial ends of the carcass layer Each of which is wound around the forming drum several times as it is, A step of forming a cord reinforcing layer in which the amplitude of the corrugated steel cord is increased as the distance from the set position of the core in the axial direction is increased, and a cylindrical tire intermediate is formed; and the tire intermediate is substantially toroidal. Pneumatic including a step of bulging and deforming, and a step of forming an unvulcanized tire by pasting at least a tread on the outer side of the tire intermediate, and a step of vulcanizing the unvulcanized tire to form a pneumatic tire This can be achieved by the tire manufacturing method.

  Secondly, a cord having a toroidal carcass layer with bead cores set at both ends and a corrugated steel cord partially disposed between the bead portion and the shoulder portion and extending in the circumferential direction and bent in a wave shape An apparatus for manufacturing a pneumatic tire having a reinforcing layer and a tread disposed at least radially outside the carcass layer, wherein a linearly extending steel cord is bent into a wave shape, and the amplitude gradually changes in the longitudinal direction. Bending means for forming a corrugated steel cord; carcass ply for supplying a carcass ply to the outside of a cylindrical forming drum to form a cylindrical carcass layer; and set positions on both outer sides in the axial direction of the carcass layer A bead core supplying means for supplying and setting the bead core to each other, and the corrugated steel cords A cord supplying means for forming a cord reinforcing layer that is increased as the amplitude of the corrugated steel cord is increased in the axial direction from the set position of the bead core on the forming drum by being wound as it is and wound several times. A cylindrical tire intermediate body having a layer, a bead core, and a cord reinforcing layer is bulged and deformed in a substantially toroidal shape, and at least a tread is attached to the radially outer side of the tire intermediate body to form an unvulcanized tire; This can be achieved by a pneumatic tire manufacturing apparatus provided with vulcanizing means for vulcanizing the unvulcanized tire to form a pneumatic tire.

  As described above, when the cylindrical tire intermediate body having the cord reinforcing layer is bulged and deformed in a substantially toroidal shape, the cord reinforcing layer is greatly stretched in the circumferential direction as it is separated from the bead core, thereby constituting the cord reinforcing layer. Although the amplitude of the corrugated steel cord decreases as the distance from the bead core increases, the corrugated steel cord having a gradually changing amplitude as in the invention according to claim 1 is wound around the cylindrical forming drum as it is a plurality of times, thereby being corrugated steel cord. If the amplitude of the cord is increased as the distance from the set position of the bead core increases in the axial direction, the above-described decrease in amplitude and increase in amplitude of the corrugated steel cord cancel each other, and the amplitude of the corrugated steel cord in the pneumatic tire becomes the cord reinforcement layer. Overall, the tire performance is improved by approximating (homogenizing) particularly in the radial direction.

  Moreover, since the corrugated steel cord whose amplitude gradually changes by bending the steel cord extending in a straight line is not produced, it does not cause excessive deformation to the steel cord, resulting in durability. In addition to being able to form a high-strength cord reinforcing layer and winding the wavy steel cord bent in advance, the amplitude of the wavy steel cord immediately after winding can be made high in each part.

  Moreover, since the steel cord is bent in a wave shape so that its amplitude gradually changes prior to winding around the cylindrical forming drum, when winding, the wavy steel cord is made a straight line parallel to the axis of the forming drum. It is sufficient to guide the traversing along, and as a result, the control during winding becomes simple and the work efficiency can be improved. The pneumatic tire as described above can be easily and efficiently formed by the apparatus according to claim 3.

  Further, if configured as in claim 2, the cord reinforcing layer can be easily and inexpensively molded with high efficiency, and if configured as in claim 4, the amplitude gradually changes. The corrugated steel cord can be manufactured easily and with high accuracy, and if configured as described in claim 5, the corrugated steel cord can be manufactured easily and with high accuracy while having a simple structure. .

Embodiment 1 of the present invention will be described below with reference to the drawings.
1 and 2, 11 is a vulcanized pneumatic radial tire used for trucks and buses, for example, and this pneumatic tire 11 has a pair of bead portions 13 each having a pair of bead cores 12 embedded therein. The side wall portions 14 extend from the bead portions 13 substantially outward in the radial direction. Reference numeral 15 denotes a tread portion having a substantially cylindrical shape, and a pair of shoulder portions 16 are located between both axial ends of the tread portion 15 and radially outer ends of the sidewall portions 14.

  The pneumatic tire 11 has a carcass layer 18 that extends between the bead cores 12 in a toroidal manner and reinforces the sidewall portions 14 and the tread portions 15. The carcass layer 18 has both end portions of the bead core 12 and the The bead cores 12 are set at both ends by folding back around the filler 19 whose inner end in the radial direction is locked to the bead core 12. The carcass layer 18 is composed of at least one (in this embodiment, one) carcass ply 21 in which a plurality of non-stretchable cords extending in the radial direction (the meridian direction), in this case, steel cords 20 are embedded. ing.

  Here, an inner liner 22 made of rubber is disposed inside the carcass layer 18 located between the bead cores 12. The carcass layer 18 may have a so-called hollow ply structure divided at the center. In addition, both end portions of the carcass layer 18 may not be folded around the bead core 12 and may end slightly inward in the radial direction from the bead core. In this case, the bead core may be divided into two inside and outside in the axial direction of the carcass layer, and the carcass layer may be sandwiched from both sides by the divided pieces of the bead core.

  Further, a belt layer 24 and a top tread 25 as a tread are disposed on the outer side in the radial direction of the carcass layer 18, and side treads 26 are disposed on both outer sides in the axial direction of the carcass layer 18. The belt layer 24 is composed of at least two (here, three) belt plies 27, and in each belt ply 27 is embedded an inextensible cord inclined in a reverse direction with respect to the tire equator S at a predetermined angle. Has been.

  Reference numerals 30 denote cord reinforcement layers disposed in the bead portion 13 axially inward of the bead core 12 and the carcass layer 18, respectively. These cord reinforcement layers 30 are at least one reinforcement ply, in this embodiment, one reinforcement. It consists of ply 31. Further, in the cord reinforcing layer 30 (reinforcing ply 31), a corrugated steel cord 32 that is bent in a wave shape (zigzag shape) and continuously extends in the circumferential direction while being spiral is embedded. The distance between the base lines L in the meridian direction of the winding of the corrugated steel cord 32 is substantially the same. The bead portion 13 is reinforced by such a cord reinforcing layer 30.

  Here, in the above-described embodiment, the pneumatic tire 11 has been described as a tire mounted on a truck / bus. However, the present invention may be applied to a tire mounted on a passenger car, an aircraft, or a large construction vehicle. . In the above-described embodiment, the pneumatic tire 11 is described as a radial tire. However, in the present invention, an aircraft bias tire in which the belt layer is omitted, or a breaker layer is disposed instead of the belt layer. It can also be applied to normal bias tires. In this manner, at least the tread is disposed on the outer side in the radial direction of the carcass layer 18.

    Next, the pneumatic tire 11 as described above can be manufactured, for example, as described below. That is, in FIGS. 3, 4 and 5, reference numeral 35 denotes a cylindrical forming drum which can be enlarged and reduced in diameter and rotated around a horizontal axis. The forming drum 35 receives a rotational driving force from a servo motor (not shown). When rotating around the axis, a sheet-like inner liner 22 is supplied to the forming drum 35 from the inner liner supplying means 36 installed in front of the forming drum 35 and wound around the inner liner 22 to form a cylindrical inner liner 22 Is molded.

  Next, a ribbon-like body 37 in which the corrugated steel cord 32 is embedded is supplied to the outside of both ends in the axial direction of the forming drum 35 (inner liner 22), and a plurality of pieces are provided around the forming drum 35 (inner liner 22). The cord reinforcing layer 30 formed into a cylindrical shape is formed by winding the ribbon-shaped body 37. The ribbon-shaped body 37 supplied to the forming drum 35 is formed by, for example, a ribbon forming apparatus 34 as shown in FIGS. Can be molded.

  4 and 5, 38 is a bobbin around which a steel cord 39 made of monofilament or stranded wire is wound many times. The steel cord 39 unwound from the bobbin 38 runs forward while extending linearly. Then, it is supplied to the bending means 40 installed in front of the bobbin 38 (downstream side). At this time, since a constant braking force is applied to the bobbin 38, a predetermined internal tension is applied to the steel cord 39 stretched between the bobbin 38 and the bending means 40.

  As shown in FIG. 6, the bending means 40 has a box-shaped support frame 41 that is fixed on the floor surface and is open on the front and rear sides. A gear 42 composed of at least a pair separated from each other, here a pair of spur gears, is housed. Both side walls located on the left and right sides of the support frame 41 are respectively formed with through-slide holes 43 extending in the vertical direction, and guide rails 44 extending in the vertical direction are laid on the front and rear inner surfaces of the slide holes 43, respectively.

  48 and 49 are a pair of upper and lower slide plates that are provided apart in the left-right direction. These upper and lower slide plates 48 and 49 are respectively stored in the slide holes 43 apart from each other, and Slide bearings (not shown) fixed to the front and rear surfaces are slidably engaged with the guide rail 44. Each upper slide plate 48 rotatably supports one side gear of the gear 42, here both ends of the horizontal rotation shaft 50 of the upper gear 42a, while each lower slide plate 49 is Of the gear 42, the other side gear, here, both ends of the horizontal rotating shaft 51 of the lower gear 42b are rotatably supported.

  54 and 55 are screw shafts extending in the vertical direction and rotatably supported by the support frame 41 via a pair of bearings 56 and 57 attached to the upper and lower ends of the outer surface of the side wall of the support frame 41. A male screw portion 58 is formed on the outer periphery of the upper side in the axial direction (vertical direction) of the screw shafts 54 and 55, respectively, and a male screw portion that is reverse to the male screw portion 58 on the outer periphery of the lower side portion in the axial direction. 59 is formed.

  63 and 64 are upper and lower screw blocks fixed to the upper and lower slide plates 48 and 49, respectively, and the male screw portions 58 of the screw shafts 54 and 55 are screwed into the upper screw blocks 63, respectively. On the other hand, male screw portions 59 of the screw shafts 54 and 55 are screwed into the lower screw blocks 64, respectively. Reference numeral 65 denotes a single drive motor attached to the top wall of the support frame 41. A pulley 66 fixed to the output shaft of the drive motor 65 and a pulley 67 fixed to the upper end of the screw shaft 54 are provided. A timing belt 68 is interposed between the pulley 69 fixed to the output shaft of the drive motor 65 and a pulley 70 fixed to the upper end portion of the screw shaft 55. Yes.

  As a result, when the drive motor 65 operates and the screw shafts 54 and 55 rotate at a constant speed, the upper and lower slide plates 48 and 49 are male screw portions 58 that are reverse screws while being guided by the guide rail 44, By 59, they move simultaneously by the same distance in the opposite directions and approach each other. Then, due to the approach and separation in the vertical direction, the distance between the rotation axes of the upper and lower gears 42a and 42b supported by the upper and lower slide plates 48 and 49, respectively, gradually changes. The distance between the external teeth 72a and 72b in the opposed upper and lower gears 42a and 42b gradually changes.

  The upper and lower slide plates 48 and 49, the screw shafts 54 and 55, the upper and lower screw blocks 63 and 64, the drive motor 65, the pulleys 66, 67, 69, and 70, and the timing belts 68 and 71, as a whole, By gradually changing the distance between the external teeth 72a of the upper gear 42a and the external teeth 72b of the lower gear 42b, a distance adjusting mechanism 73 capable of adjusting the amount of biting is configured.

  Reference numeral 77 denotes a drive motor fixed to the upper surface of one (here, the left) upper slide plate 48. The drive motor 77 is fixed to the pulley 78 fixed to the output shaft of the drive motor 77 and the rotary shaft 50 of the upper gear 42a. The pulley 79 is connected via a timing belt 80. Reference numeral 81 denotes a drive motor fixed to the lower surface of one (left) lower slide plate 49. The drive motor 81 is fixed to the pulley 82 fixed to the output shaft of the drive motor 81 and the rotary shaft 51 of the lower gear 42b. The pulley 83 is connected via a timing belt 84.

  When the driving force of the drive motors (drive sources) 77 and 81 is transmitted to the upper and lower gears 42a and 42b, the upper and lower gears 42a and 42b are engaged with each other while the external teeth 72a and 72b bite each other. Rotate at a constant speed in the reverse direction with a predetermined circumferential interval between them. The drive motors 77, 81, pulleys 78, 79, 82, 83, and timing belts 80, 84 described above generally apply a drive force to the pair of gears 42 so that these gears 42 are at the same speed in the opposite direction (the same angular speed). ) Constitutes a drive mechanism 85 for driving and rotating.

  When the steel cord 39 is supplied between the gears 42 when the gear 42 is rotated by these drive mechanisms 85, the steel cord 39 moves up and down on the external teeth 72a and 72b when passing between the gears 42. The steel cord 39 is continuously bent in a wave shape while being plastically deformed, and the steel cord 39 becomes a wave-like steel cord 32 bent in a wave shape in the vertical plane.

  In such a bending operation, the distance adjustment mechanism 73 is actuated to move the upper and lower gears 42a, 42b facing each other closer to each other and gradually change the distance between the rotation axes. The upper and lower gears 42a and 42b are gradually approached, and the distance between the external teeth 72a and 72b in the gears 42a and 42b is gradually reduced. As a result, the amplitude a of the corrugated steel cord 32 formed by passing between the gears 42 a and 42 b as described above gradually increases along the longitudinal direction of the corrugated steel cord 32. Conversely, when the upper and lower gears 42a, 42b are gradually separated, the amplitude a of the waved steel cord 32 gradually decreases.

  At this time, the amplitude a of the corrugated steel cord 32 (distance from the base line L to the highest point of the wave) is half of the amount of biting between the external teeth 72a and 72b at the time of molding, and the external teeth It changes gradually corresponding to the change in the distance between 72a and 72b. On the other hand, the wavelength λ of the corrugated steel cord 32 is the same as the circumferential distance between two adjacent external teeth 72a, 72b on a circle passing through the midpoint between the rotation axes of the upper and lower gears 42a, 42b. These are constant in any longitudinal position (see FIG. 7 for amplitude a and wavelength λ).

  The support frame 41, the gear 42, the distance adjustment mechanism 73, and the drive mechanism 85 described above as a whole have the steel cord 39 that extends linearly while gradually changing the distance between the external teeth 72a and 72b. By passing between 42b, the said bending means 40 which shape | molds the corrugated steel cord 32 from which the amplitude a changes gradually in a longitudinal direction is comprised. Here, the above-mentioned amplitude a may change continuously, or may change in steps every time one or more times are wound.

  If the bending means 40 having the gear 42, the distance adjusting mechanism 73, and the drive mechanism 85 is used, the corrugated steel cord 32 with the amplitude a gradually changing can be manufactured easily and with high accuracy prior to winding described later. be able to. Further, since the gear 42 is constituted by a spur gear as described above and the rotation axes thereof are parallel to each other, the corrugated steel cord 32 in which the amplitude a is gradually changed as described above can be obtained easily and easily. Can be manufactured with high accuracy.

  In the above-described embodiment, the corrugated steel cord 32 is formed by the pair of gears 42. However, in the present invention, a pair of horizontal disks in which the outer edges overlap with each other are installed and A number of pins protruding upward are fixed to the outer edge of the upper surface of the side disk at equal distances in the circumferential direction, while a number of pins protruding downward to the outer edge of the lower surface of the upper disk are fixed at the same distance in the circumferential direction. When these two discs are fixed apart and rotated in the opposite direction around the axis of rotation, a straight steel cord is engulfed between the pins that invade each other and bent continuously in a wave shape, A corrugated steel cord may be formed.

  Even in this case, the amount of biting between these pins can be adjusted by gradually changing the distance between the rotation axes of both disks, so that a corrugated steel cord whose amplitude gradually changes can be easily formed. be able to. In the above-described embodiment, a spur gear is used as the gear 42. However, in the present invention, when the diameter of the steel cord 39 is sufficiently small with respect to the tooth width, a bevel gear or the like is immediately used as the gear. Can do. Further, in the present invention, the bending means may be placed horizontally so that the rotation axis of the gear in the bending means is parallel to the vertical direction.

  4 and 5, reference numeral 90 denotes a free-turning sideways roller installed in front of the bending means 40, and the rotation axis of the sideways roller 90 is parallel to the rotation axis of the gear 42. Then, after the corrugated steel cord 32 formed by the bending means 40 contacts the outer periphery of the sideways roller 90 by about 1/4 turn, the direction is changed and the vehicle runs downward. At this time, the corrugated steel cord 32 bent in a wavy shape in the vertical plane is twisted by 90 degrees between the bending means 40 and the sideways roller 90 and bent in a wavy shape in the horizontal plane.

  91 is a roller group composed of a plurality of rollers 92 disposed in front of the roll-down roller 90 and below the roll-down roller 90, and at least one of the rollers 92 constituting the roller group 91 is illustrated. It is driven and rotated by a drive motor that is not. Then, as described above, the corrugated steel cord 32 that is twisted by 90 degrees by the sideways roller 90 runs forward while in contact with the outer periphery of the rollers 92 constituting the roller group 91 one after another. Since the peripheral speed of 92 is equal to the traveling speed of the corrugated steel cord 32 when discharged from the bending means 40, the corrugated steel cord 32 is supplied forward without changing the amplitude a and the wavelength λ. .

  93 is a covering means composed of a pair of covering rollers 94 installed in front of the roller group 91. These covering rollers 94 are free to rotate and are arranged apart from each other in the vertical direction. The amplitude a gradually changes between the covering rollers 94 as described above. Here, the corrugated steel cord 32 in which the amplitude a gradually increases, and the thin rubber ribbon 95 sandwiching the corrugated steel cord 32 from above and below are provided. When supplied, the thin rubber ribbon 95 is pressed by the covering roller 94 and is brought into close contact with the corrugated steel cord 32 while sandwiching the corrugated steel cord 32 therebetween, thereby covering the corrugated steel cord 32 from both sides.

  In this way, the ribbon-like body 37 composed of the corrugated steel cord 32 and the thin rubber ribbon 95 is formed. Here, the thin rubber ribbon 95 is slightly wider than twice the amplitude a of the corrugated steel cord 32, and the width gradually increases so that the width follows the change of the amplitude a in the corrugated steel cord 32. It is comprised from the strip | belt-shaped unvulcanized rubber shape | molded so that it may become.

  The bending means 40, the roll-over roller 90, the roller group 91, and the covering means 93 are bent as a whole with the supplied straight steel cord 39 in a wave shape, and the wavy steel cord 32 with a thin rubber ribbon 95 is bent. By coating, the ribbon forming apparatus 34 for forming the ribbon-like body 37 in which the corrugated steel cord 32 is embedded is configured.

   100 is a delivery mechanism installed in front of the covering means 93. This delivery mechanism 100 is composed of a plurality of rollers 101 parallel to the roller 92, and at least one roller 101 is a drive motor (not shown). , So that the peripheral speed is equal to the traveling speed of the ribbon 37 discharged from the covering roller 94. The ribbon-like body 37 travels in contact with the outer periphery of the roller 101 of the delivery mechanism 100 one after another, whereby the ribbon-like body 37 is moved from the delivery mechanism 100 to the corrugated steel cord 32 embedded therein. Are supplied toward the forming drum 35 without changing the amplitude a and the wavelength λ.

   Reference numeral 102 denotes a traverse mechanism installed between the feed mechanism 100 and the forming drum 35. The traverse mechanism 102 includes a guide body 103 extending parallel to the rotation axis of the forming drum 35, and the guide body 103. A movable guide 104 that is movably supported and regulates the position of the ribbon-shaped body 37 that travels toward the molding drum 35 (the position of the molding drum 35 in the axial direction), and the movable guide 104 along the guide body 103. And a drive mechanism having a screw mechanism (not shown), a drive motor, and the like that traverse the ribbon-like body 37 in the rotation axis direction of the forming drum 35 by moving the ribbon-like body 37.

  When the ribbon-shaped body 37 is supplied from the feed mechanism 100 to the forming drum 35, the movable guide 104 of the traverse mechanism 102 moves at a constant speed along the guide body 103, and the ribbon around the forming drum 35 The cylindrical body 37 is spirally wound from the outer side in the axial direction a plurality of times toward the inner side in the axial direction, and the cylindrical cord reinforcing layer 30 is formed outside the forming drum 35. When the cord reinforcing layer 30 is formed in this way, the ribbon-like body 37 is cut in the width direction. Thus, if the cord reinforcing layer 30 is formed by winding the ribbon-like body 37 (the corrugated steel cord 32) spirally a plurality of times, the cord reinforcing layer 30 can be easily and inexpensively easily and highly efficiently. Can be molded.

  Here, the corrugated steel cord 32 embedded in the ribbon-shaped body 37 is formed so that the amplitude a gradually increases by the bending means 40 as described above, and the corrugated steel formed in this way. Since the cord 32 is conveyed without being changed in the amplitude a and the wavelength λ from the time when it is formed by the bending means 40 until it is wound around the forming drum 35, the corrugated steel cord 32 ( When the ribbon-shaped body 37) is supplied as it is to the forming drum 35 while being traversed by the traversing mechanism 102 from the feed mechanism 100 and wound a plurality of times, the amplitude a increases as it goes from the outside in the axial direction to the inside in the axial direction. That is, it becomes the minimum at a position closest to a set position P (see FIGS. 3, 5, 7) of the bead core 12 to be described later, and gradually increases from the set position P in the axial direction. Increase.

  As a result, the amplitude a of the corrugated steel cord 32 constituting the cord reinforcing layer 30 formed on the forming drum 35 is adjusted to gradually increase as the distance from the set position P of the bead core 12 increases in the axial direction. As a whole, the servo motor for driving the feeding mechanism 100, the traversing mechanism 102, and the forming drum 35 is supplied to the forming drum 35 as it is and wound around the forming drum 35 by supplying the corrugated steel cord 32 as it is. A cord supplying means 105 for forming the cord reinforcing layer 30 in which the amplitude “a” of the steel cord 32 becomes larger in the axial direction from the set position P of the bead core 12 is configured.

  In the above-described embodiment, the wavy steel cord 32 (ribbon-like body 37) whose amplitude a gradually increases is wound from the outside in the axial direction of the forming drum 35 toward the inside in the axial direction. In this case, the wavy steel cord having a gradually decreasing amplitude is wound from the inner side in the axial direction of the forming drum toward the outer side in the axial direction, so that the amplitude of the wavy steel cord increases as the distance from the set position of the bead core increases in the axial direction. The formed cord reinforcing layer may be formed. The steel cord having a gradually reduced amplitude can be formed by gradually separating the rotation axes of the upper and lower gears as described above.

  Here, as described above, while using the corrugated steel cord 32 (ribbon-shaped body 37) with the amplitude a gradually increasing, the distance between the base lines L of the adjacent corrugated steel cords 32 is made substantially the same as described above. Then, at the position close to the set position P, the width of the ribbon-shaped body 37 is narrower than the width of the ribbon-shaped body 37 at a position spaced apart from the set position P in the axial direction. A gap 106 is generated between the side edges of the ribbon-like body 37, and the gap 106 is gradually narrowed away from the set position P. And when comprised in this way, even when it becomes the pneumatic tire 11, the distance between the base lines L of the adjacent corrugated steel cord 32 can be made substantially the same, and the corrugated steel cord 32 in the cord reinforcement layer 30 can be made the same. The distribution becomes uniform, and the reinforcing effect of the cord reinforcing layer 30 is improved.

  In the above-described embodiment, the single corrugated steel cord 32 is covered with the thin rubber ribbon 95 to form the ribbon-shaped body 37, and the ribbon-shaped body 37 is wound around the molding drum 35. , After arranging a small number of, for example, 2-5 corrugated steel cords, the corrugated steel cords are covered with a thin rubber ribbon to form a ribbon-shaped body, and the ribbon-shaped body is wound around a molding drum. Alternatively, one or a small number of corrugated steel cords may be left bare, that is, without being covered with rubber, and further, the circumference of one corrugated steel cord may be coated with an equal thickness of rubber. Then, it may be supplied to the forming drum and wound.

  Furthermore, in the above-described embodiment, the wavy steel cord 32 (ribbon-like body 37) is wound around the forming drum 35 a plurality of times in a spiral manner. However, in this invention, the wavy steel cord is wound around the forming drum from one turn. After wrapping in the circumferential direction substantially a little angle, then winding the slanted remaining angle diagonally and shifting the corrugated steel cord by a predetermined distance inward in the axial direction is repeated multiple times to form the corrugated steel cord multiple times on the forming drum. You may make it wind. As described above, when winding the ribbon-shaped body around the forming drum, it is sufficient to guide the ribbon-shaped body (the corrugated steel cord) along the straight line parallel to the rotation axis of the forming drum. Control is easy.

  3, 4, and 5, reference numeral 110 denotes a carcass supply means installed in front of the forming drum 35. The carcass supply means 110 includes an inner liner 22 and a cord reinforcing layer 30 (corrugated steel cord 32) with respect to the forming drum 35. Is finished, the sheet-like carcass ply 21 is supplied to the outside of the forming drum 35 (the inner liner 22 and the cord reinforcing layer 30) and wound around it to form the cylindrical carcass layer 18.

  Next, after reducing the diameter of the carcass layer 18 axially outside the set position P by the diameter reducing means (not shown) and reducing the diameter as shown by the phantom line, the bead core 12 with the filler 19 is The material is supplied to a set position P located outside the both ends in the axial direction of the layer 18, and here, it is transported to the step formed in the carcass layer 18 by the reduced diameter and set.

  Next, the carcass layer 18 axially outside the bead core 12 is folded around the bead core 12 as shown in FIG. 8 by a folding mechanism (not shown), and then the forming drum 35 (carcass layer) is formed by the side supply means 112 shown in FIG. A sheet-like side tread 26 is supplied and wound around the outer side of 18) to form a cylindrical side tread 26 as shown in FIG.

  As a result, a cylindrical tire intermediate body 113 (green case) having the inner liner 22, the cord reinforcing layer 30, the carcass layer 18, the bead core 12, the filler 19, and the side tread 26 is formed around the forming drum 35. When the cord reinforcing layer 30 is disposed on the axially outer side of the folded portion 17 in the pneumatic tire 11, the cord reinforcing layer 30 is formed by winding the ribbon-like body 37 after the carcass layer 18 is folded. .

  Next, the tire intermediate body 113 is conveyed from the forming drum 35 to the shaping drum 117 shown in FIG. 9 by conveyance means (not shown), and is gripped from the radially inner side by the bead lock mechanism 118 of the shaping drum 117, and then the bead lock. While the mechanisms 118 are brought close to each other, air is supplied into the tire intermediate 113 to cause the tire intermediate 113 to bulge and deform in a substantially toroidal shape. At this time, a belt tread band 119 formed by a band forming drum (not shown) and including the belt layer 24 and the top tread 25 is conveyed to the radially outer side of the tire intermediate 113 by the conveying means 120, and the tire intermediate 113 is conveyed. An unvulcanized tire 121 having a substantially toroidal shape is attached to the outer side in the radial direction of the tire.

  The above-described shaping drum 117 and conveying means 120 as a whole cause the tire intermediate body 113 to bulge and deform in a substantially toroidal shape, and at least the tread, here the belt layer 24 and the top tread 25, radially outward of the tire intermediate body 113. The forming means 122 for forming the unvulcanized tire 121 is configured by pasting. Such an unvulcanized tire may be formed by a single stage type drum. In this case, the drum serves as both a forming drum and a forming means. In the present invention, the carcass layer may be folded around the bead core in the shaping drum.

  Further, when the unvulcanized tire is for a bias tire, after molding the unvulcanized tire by pasting only the breaker layer and the tread or the tread to the tire intermediate body on the molding drum, the unvulcanized tire is molded. The tire bulges and deforms in a substantially toroidal shape. When the unvulcanized tire 121 is formed in this way, the lower side mold 125, the upper side mold 126, and the sector mold 127 as shown in FIG. The pneumatic tire 11 is carried into the vulcanizing means 128 provided and vulcanized by the vulcanizing means 128 to form a toroidal shape. The unvulcanized tire 121 may be vulcanized by a vulcanizing means having a mold that is divided into two vertically.

  Here, when the cord reinforcing layer 30 is deformed from a cylindrical shape to a substantially bowl shape by the deformation of the tire intermediate body 113 (unvulcanized tire 121) described above into a substantially toroidal shape, the cord reinforcing layer 30 is separated from the bead core 12. Therefore, the wave-like steel cord 32 constituting the cord reinforcing layer 30 has a smaller amplitude a as the distance from the bead core 12 increases, and the wave-like steel cord 32 has an amplitude a. The entire reinforcing layer 30 is considerably uneven, especially when viewed in the radial direction.

  Therefore, in this embodiment, as described above, the corrugated steel cord 32 having the gradually increasing amplitude a is wound around the cylindrical forming drum 35 a plurality of times as it is, so that the amplitude a of the corrugated steel cord 32 is bead core. The distance from the 12 set positions P increases in the axial direction. As a result, the amplitude decrease and the amplitude increase of the corrugated steel cord 32 described above cancel each other, and the amplitude a of the corrugated steel cord 32 in the pneumatic tire 11 is approximated (uniformly) in the entire cord reinforcing layer 30, particularly when viewed in the radial direction. Tire performance is improved.

  Further, since the corrugated steel cord 32 whose amplitude a gradually increases by bending the steel cord 39 extending linearly is manufactured, the steel cord is not excessively deformed. The cord reinforcing layer 30 having high properties can be formed and the pre-bent corrugated steel cord 32 is wound as it is, so that the amplitude a of the corrugated steel cord 32 immediately after winding is determined for each part of the cord reinforcing layer 30. With high accuracy.

  Moreover, since the steel cord is bent into a wave shape so that the amplitude a gradually changes prior to winding around the cylindrical forming drum 35, the corrugated steel cord 32 is parallel to the axis of the forming drum 35 during winding. It is sufficient to guide the traverse along the straight line, and as a result, the control at the time of winding becomes simple and the work efficiency can be improved.

  Here, when the corrugated steel cord 32 (ribbon-shaped body 37) whose amplitude a gradually increases as described above is wound around the forming drum 35, the corrugated steel wound at the position closest to the set position P of the bead core 12 is wound. If the amplitude a of the cord 32 is substantially the same as the amplitude a of the corrugated steel cord 32 located on the radially outermost side of the cord reinforcing layer 30 in the state of the pneumatic tire 11, the corrugated shape in the entire cord reinforcing layer 30 can be easily obtained. The amplitude a of the steel cord 32 can be strongly uniformed, which is preferable.

    In the above-described embodiment, the cord reinforcing layer 30 is arranged in the bead portion 13 in the axial direction inner side than the bead core 12. However, in the present invention, as shown in FIG. The reinforcing layer 131 may be disposed while being superimposed on the folded portion 17 of the carcass layer 18 in the bead portion 13 axially outside the bead core 12. In this case, after the carcass layer 18 is formed on the forming drum 35 and the bead core 12 is set at the set position P, more specifically, after the formed carcass layer 18 is folded around the bead core 12, a ribbon shape is formed. The cord reinforcement layer 131 is formed by winding the body 37.

  Furthermore, in the present invention, the cord reinforcing layer 30 may be disposed on the inner side in the axial direction of the bead core 12, and the cord reinforcing layer 131 may be disposed on the outer side in the axial direction. Further, the cord reinforcing layer may be disposed in the vicinity of the tire maximum width position or between the tire maximum width position and the shoulder portion. In short, it may be partially disposed between the bead portion and the shoulder portion. That's fine. Furthermore, in the above-described embodiment, the ribbon-shaped body 37 is directly wound around the molding drum 35 immediately after molding by directly connecting the molding means of the ribbon-shaped body 37 and the molding drum 35. The ribbon-shaped body may be temporarily wound into a roll shape after forming and temporarily stored, and then may be unwound from the roll and wound around a forming drum as necessary.

  In the above-described embodiment, the screw mechanism is used as the distance adjusting mechanism 73. However, in the present invention, a rack and pinion mechanism, a cylinder mechanism, or the like may be used as the distance adjusting mechanism. In the above-described embodiment, the gears 42a and 42b are rotated by separate drive motors 77 and 81, respectively, but in the present invention, these gears are rotated at a constant speed by a single drive source. May be.

  The present invention can be applied to the industrial field of pneumatic tires in which a cord reinforcing layer of a corrugated steel cord is disposed between a bead portion and a shoulder portion.

1 is a meridian cross-sectional view of a pneumatic tire showing Embodiment 1 of the present invention. It is the II arrow directional view of FIG. 1 where one part was fractured | ruptured. It is a schematic sectional side view explaining the winding operation | work with a forming drum. It is a schematic front view of the ribbon forming apparatus and the vicinity of the forming drum. It is a schematic plan view of the ribbon forming apparatus and the vicinity of the forming drum. It is side surface sectional drawing of a bending means. It is an expanded partial side view explaining the winding state of a corrugated steel cord. It is a schematic sectional side view explaining the winding operation | work with a forming drum. It is a schematic sectional side view explaining the shaping | molding operation | work with a shaping drum. It is front sectional drawing explaining the vulcanization operation | work by a vulcanization means. It is meridian sectional drawing similar to FIG. 1 which shows other embodiment of this invention.

Explanation of symbols

11 ... Pneumatic tire 12 ... Bead core
13 ... Bead part 16 ... Shoulder part
18 ... Carcass layer 21 ... Carcass ply
25 ... Tread 30 ... Cord reinforcement layer
32 ... Wavy steel cord 35 ... Forming drum
39 ... Steel cord 40 ... Bending means
42 ... Gear 72a, 72b ... External teeth
73… Distance adjustment mechanism 85… Drive mechanism
105 ... Cord supply means 110 ... Carcass supply means
111 ... Bead core supply means 113 ... Tire intermediate
121 ... Unvulcanized tire 122 ... Molding means
128 ... Vulcanization means P ... Set position a ... Amplitude

Claims (5)

    A carcass layer extending in a toroidal shape with bead cores set at both ends, a cord reinforcing layer having a wavy steel cord that is partially disposed between the bead portion and the shoulder portion, extends in the circumferential direction, and is bent in a wave shape; A method of manufacturing a pneumatic tire having a tread disposed at least radially outward of a carcass layer, wherein a corrugated steel cord in which a linearly extending steel cord is bent into a corrugated shape and the amplitude gradually changes in the longitudinal direction. And forming the cylindrical carcass layer by winding the carcass ply around the cylindrical forming drum, and setting the bead cores at the set positions outside both axial ends of the carcass layer, while the corrugated steel cord Is wound around the molding drum multiple times as it is and axially from the set position of the bead core. Forming a cord reinforcing layer in which the amplitude of the corrugated steel cord is increased as the distance from each other increases, forming a cylindrical tire intermediate, and expanding and deforming the tire intermediate in a substantially toroidal shape, A pneumatic tire comprising: a step of pasting at least a tread on an outer side of a tire intermediate to form an unvulcanized tire; and a step of vulcanizing the unvulcanized tire to form a pneumatic tire. Production method.     The method for manufacturing a pneumatic tire according to claim 1, wherein the cord reinforcing layer is formed by winding the corrugated steel cord in a spiral manner a plurality of times.     A carcass layer extending in a toroidal shape with bead cores set at both ends, a cord reinforcing layer having a wavy steel cord that is partially disposed between the bead portion and the shoulder portion, extends in the circumferential direction, and is bent in a wave shape; An apparatus for manufacturing a pneumatic tire having a tread disposed at least radially outside of a carcass layer, wherein a corrugated steel cord in which a linearly extending steel cord is bent into a wave shape and an amplitude gradually changes in a longitudinal direction. A bending means for forming, a carcass ply for supplying a carcass ply to the outside of a cylindrical forming drum and forming a cylindrical carcass layer by winding, and a bead core being supplied to a set position outside both axial ends of the carcass layer And the bead core supply means for setting each, and the corrugated steel cord to the forming drum A cord supplying means for forming a cord reinforcing layer which is increased as the amplitude of the corrugated steel cord is axially separated from the set position of the bead core on the forming drum by being supplied and wound a plurality of times; and the carcass layer A cylindrical tire intermediate body having a bead core and a cord reinforcing layer is bulged and deformed in a substantially toroidal shape, and at least a tread is attached to the radially outer side of the tire intermediate body to form an unvulcanized tire; and An apparatus for manufacturing a pneumatic tire, comprising: a vulcanizing unit that vulcanizes the unvulcanized tire to form a pneumatic tire.     The bending means drives at least a pair of gears, a distance adjusting mechanism capable of gradually changing the distance between the outer teeth of the gear on one side and the outer teeth of the gear on the other side, and the gear. A rotating drive mechanism, and passing the steel cord that extends linearly between the gears while gradually changing the distance between the external teeth, thereby forming a wavy steel cord with gradually changing amplitude. The pneumatic tire manufacturing apparatus according to claim 3.     The pneumatic tire manufacturing apparatus according to claim 4, wherein the gear is constituted by a spur gear, and rotation axes thereof are parallel to each other.

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