JP5376589B2 - Tire manufacturing apparatus and tire manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make an unvulcanized tread be contracted along the periphery of a molded article and stuck accurately on the periphery of the molded article with the unevenness of the surface suppressed when an unvulcanized tire is molded. <P>SOLUTION: The annular unvulcanized tread T whose inner diameter is smaller than the outer diameter of the molded article H is formed on a drum, and the drum is expanded to make the inner diameter of the unvulcanized tread T larger than the outer diameter of the molded article H. The expanded unvulcanized tread T is held by a holding means 20, moved, and arranged to face the periphery of the molded article H. The holding of the unvulcanized tread T is lifted, and the unvulcanized tread T is contracted toward the periphery of the opposite molded article H. The unvulcanized tread T, after being deformed along the periphery of the molded article H, is pressed by a press roller 3R, and pressure-bonded/stuck to/on the periphery of the molded article H. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a tire manufacturing apparatus and a tire manufacturing method for forming an unvulcanized tire by attaching an unvulcanized tread to the outer periphery of a molded body.

  In the unvulcanized tire molding step, an unvulcanized tread is disposed on the outer periphery of the molded body, and then the unvulcanized tread is pressed and pressed against the opposed molded body. Conventionally, a belt-like unvulcanized tread is wound once around the outer periphery of the swelled molded body and stitched, and the unvulcanized tread is attached to the outer periphery of the molded body to form an unvulcanized tire. A method for manufacturing a motorcycle tire is known (see Patent Document 1).

FIG. 13 is a cross-sectional view in the tire width direction schematically showing an example of a conventional tire manufacturing method for manufacturing a tire in this way, and shows a manufacturing procedure of a motorcycle tire.
In the illustrated example, first, using a forming drum (not shown), various tire constituent members such as a carcass ply and a bead core are combined to form a cylindrical shape, and a central portion thereof is expanded (see FIG. 13A). Then, a cord C is spirally wound around a predetermined range of the outer peripheral surface to form a belt (spiral belt) B.

  Next, the belt-shaped unvulcanized tread T is wound around the outer periphery (see FIG. 13B) of the molded body H formed in this way, and then the molded body H is rotated, so that the pair of pressing rollers 100 is moved. Then, it is pressed against the outer peripheral surface of the unvulcanized tread T and moved from the central part in the width direction (left-right direction in FIG. 13) toward both outer sides. As a result, the pair of pressing rollers 100 (see FIG. 13C) is moved along the outer peripheral surface of the unvulcanized tread T to press the unvulcanized tread T in a spiral shape and stitched over the entire surface to perform unvulcanized. The sulfur tread T is pressure-bonded to the molded body H. The unvulcanized tread T is gradually narrowed radially inward (lower side in FIG. 13C) toward the end in the width direction along with the stitching, and is matched with the curved outer peripheral surface of the molded body H. The inner peripheral surface is deformed and adhered to the outer peripheral surface of the molded body H.

  At that time, since the circumferential length of the side portion of the unvulcanized tread T changes before and after the deformation, excessive portions corresponding to the difference overlap, and so on, the surface is likely to generate wrinkles and wavy undulations. . Along with this, the uncured tire after molding has a variation in thickness (gauge) and appearance around the side of the unvulcanized tread T (Z range in FIG. 13C), and the uniformity decreases. Unevenness such as wrinkles may occur on the side part. In particular, in a motorcycle tire, as the size (width) increases, the difference in diameter between the center portion and the side portion in the tire width direction also increases, so the amount of deformation of the side portion of the unvulcanized tread T And the generated irregularities tend to be large or increase. If unevenness occurs in the side portion of the unvulcanized tire in this way, in some cases, there may be some unevenness on the surface of the tire after vulcanization or appearance problems such as bares. It is necessary to deal with unevenness by applying an outer surface liquid to the surface of the unvulcanized tire.

  However, as the degree of unevenness of the unvulcanized tread T increases, it becomes difficult to deal with the unevenness, and the risk of problems during vulcanization increases. Therefore, from the viewpoint of dealing with these more appropriately and effectively, it is required to suppress unevenness generated on the surface of the unvulcanized tread T. In addition, from the viewpoint of further improving the uniformity by increasing the uniformity of the thickness along the circumferential direction of the tire, the unvulcanized tread T is uniformly and accurately attached to the molded body H, and the unvulcanized There is a demand for reducing variations in tire thickness.

JP 2007-76182 A

  The present invention has been made in view of such conventional problems, and its purpose is to shrink an unvulcanized tread along the outer periphery of a molded body when molding an unvulcanized tire, In other words, the surface unevenness is suppressed and the surface is adhered to the outer periphery of the molded body with high accuracy. Another object of the present invention is to improve the uniformity of the tire by increasing the uniformity in the circumferential direction of the unvulcanized tread adhered to the molded body.

The present invention is a tire manufacturing apparatus for forming an unvulcanized tire by attaching an unvulcanized tread to the outer periphery of a molded body, and an expandable / contractable drum in which an annular unvulcanized tread is formed on the outer periphery, Diameter expansion means for expanding the diameter of the drum to expand the annular unvulcanized tread, holding means for holding the expanded unvulcanized tread, and unvulcanized tread held by the holding means to be molded An arrangement means arranged to face the outer circumference of the molding body, a holding release means for releasing the holding of the unvulcanized tread facing the outer circumference of the molded body, and an unvulcanized tread released from holding by the holding means. A pressing unit that presses the molded body and presses and adheres to the outer periphery of the molded body, and the drum is disposed in a circumferential direction of the drum and is disposed so as to surround the plurality of segments. an elastic band that has been The friction coefficient between the inner peripheral surface and the segments of the elastic band in contact with the segments, when expanded deformation of the elastic band associated with the diameter of the segments, characterized in that the possible slip value for the segment.
The present invention also relates to a tire manufacturing method for forming an unvulcanized tire by attaching an unvulcanized tread to the outer periphery of a molded body, and comprising an elastic band surrounding a plurality of segments arranged in the circumferential direction of the drum. A step of forming an annular unvulcanized tread having an inner diameter smaller than the outer diameter of the molded body on the outer peripheral surface, a step of expanding and displacing a plurality of segments, and an expansion of the segment contacting the elastic band with the inner peripheral surface. A process of elastically deforming in accordance with the radial displacement and expanding the inner diameter of the annular unvulcanized tread to be larger than the outer diameter of the molded body, and holding the expanded unvulcanized tread and holding the outer circumference of the molded body A step of disposing the unvulcanized tread, releasing the unvulcanized tread, and shrinking the unvulcanized tread toward the outer periphery of the opposed molded body, and the contracted unvulcanized tread to be molded. And press the unvulcanized tread Includes a step of attaching and pressed in circumference, and the friction coefficient between the inner peripheral surface and the segments of the elastic band in contact with the segment, when expanded deformation of the elastic band associated with the diameter of the segment, the segment On the other hand, it is characterized by a value that allows sliding .

  According to the present invention, at the time of molding an unvulcanized tire, the unvulcanized tread is shrunk along the outer periphery of the molded body, and the unevenness on the surface is suppressed, and the unvulcanized tread is adhered to the outer periphery of the molded body with high accuracy. be able to. Moreover, the uniformity of the circumferential direction of the unvulcanized tread affixed to the to-be-molded body can be improved, and the uniformity of the tire can be improved.

It is a schematic block diagram which shows the tire manufacturing apparatus of this embodiment. It is a principal part side view which shows typically the formation apparatus of the unvulcanized tread of this embodiment. FIG. 3 is a side view of an essential part showing a state where an annular unvulcanized tread is formed on the drum of FIG. 2. It is the side view which looked at the holding | maintenance means of the unvulcanized tread from the arrow Y direction of FIG. It is a top view which expands and shows the division | segmentation holding member of this embodiment. It is the side view which looked at the support means of the side part of an unvulcanized tread from the arrow Y direction of FIG. It is principal part sectional drawing which expands and shows a part of support means of FIG. It is a schematic diagram which shows the manufacturing process of the unvulcanized tire of this embodiment. It is a graph which shows the expansion | extension rate of the unvulcanized tread after diameter expansion. FIG. 10A is a side view showing the main part of the holding means of the comparative example, and FIG. 10B is an enlarged plan view showing the divided holding member of the comparative example. It is a graph which shows the expansion | extension rate of the unvulcanized tread after shrinkage | contraction. It is a graph which shows the variation in the thickness of the tread of an implementation product and a conventional product. It is sectional drawing of the tire width direction which shows the example of the conventional tire manufacturing method typically.

Hereinafter, an embodiment of a tire manufacturing apparatus and a tire manufacturing method of the present invention will be described with reference to the drawings.
The tire manufacturing apparatus according to the present embodiment forms an unvulcanized tire by attaching an inner periphery of an annular (cylindrical) unvulcanized tread to the outer periphery of a molded body, for example, for a motorcycle or a passenger car. A tire having a tread such as a tire or a tire filled with another gas is manufactured. Hereinafter, taking a motorcycle tire as an example, a procedure, operation, and the like for forming the unvulcanized tire will be described.

  In addition, a to-be-molded body is a target object shape | molded by affixing cyclic | annular unvulcanized treads, such as an unvulcanized tire in the middle of shaping | molding, a tire case, or an intermediate molded body. An unvulcanized tire is a tire provided with at least an unvulcanized tread, and is molded by attaching an unvulcanized tread to a body to be molded at a predetermined stage of tire molding. This molded object is formed into a cylindrical shape by, for example, molding using a molding drum in the same manner as described above (see FIG. 13) and combining various tire components such as carcass ply and bead core on the molding drum. Then, the central part is bulged and formed into a shape before the unvulcanized tread is attached. However, the molded body may be formed into a shape before pasting of the unvulcanized tread by arranging tire constituent members in order on the rigid core, etc. An unvulcanized tread is affixed to. Here, the object to be molded is formed by a forming drum, a cord is spirally wound around the outer peripheral surface thereof to form a belt (spiral belt), and then an annular unvulcanized ring separately formed on the outer periphery. A tread is placed.

FIG. 1 is a schematic configuration diagram showing a tire manufacturing apparatus according to the present embodiment, and its main part is schematically shown in a plan view.
As shown in the figure, the tire manufacturing apparatus 1 includes a forming drum 2 (first forming drum) for forming a molded body, and a forming apparatus 10 for forming an annular unvulcanized tread with the drum 12 (second forming drum). The holding means 20 for holding the unvulcanized tread after the formation and the support means 40 for supporting the side portion of the unvulcanized tread are provided. The axes of the forming drum 2 and the drum 12 and the central axes of the holding means 20 and the support means 40 are all located on the same center line CL, and the holding means 20 and the support means 40 are located on the center line CL. And move between them in concentric fashion with both drums 2, 12.

  Further, the tire manufacturing apparatus 1 includes moving means for moving the holding means 20 and the support means 40 together, and arranging means (not shown) for disposing the annular unvulcanized tread on the outer periphery of the molding drum 2. )). Thereby, the tire manufacturing apparatus 1 moves the holding means 20 and the support means 40 to the outer peripheral side of both the drums 2 and 12, and holds the unvulcanized tread on the drum 12 by the holding means 20. The unvulcanized tread to be held is arranged so as to face the molding drum 2 (the outer periphery of the molded body).

  Further, the tire manufacturing apparatus 1 includes a pressing means 3 on the outer peripheral side of the forming drum 2, and a pair of freely rotatable disk-shaped pressing rollers 3R (stitchers) are pressed / moving means (not shown) as will be described later. To press the unvulcanized tread disposed on the molded body and move it along the outer surface. At that time, the molding drum 2 is rotated around the axis by a rotating means (not shown), the molding to be held by the molding drum 2 is rotated, and the unvulcanized tread is spirally pressed and stitched.

  In addition, the tire manufacturing apparatus 1 includes a control unit 70 that controls the entire apparatus. The control means 70 is, for example, a computer including a microprocessor (MPU) 71, a ROM (Read Only Memory) 72 for storing various programs, and a RAM (Random Access Memory) 73 for temporarily storing data directly accessed by the MPU 71. Each part of the apparatus is connected via a connecting means. Thereby, the control means 70 transmits / receives a control signal and various data with each part of an apparatus, and performs each operation | movement. Hereinafter, each part of the apparatus will be described in order. First, the forming apparatus 10 having the unvulcanized tread supply means 11 and the drum 12 will be described.

FIG. 2 is a main part side view schematically showing the unvulcanized tread forming apparatus 10 and shows an intermediate stage of forming the unvulcanized tread.
As shown in the figure, the forming apparatus 10 winds a belt-shaped unvulcanized tread T supplied from the supply unit 11 shown in FIG. 1 around the drum 12 to form an annular unvulcanized tread T. The supply means 11 continuously extrudes the unvulcanized tread T having a predetermined cross-sectional shape by an extruder or continuously feeds the unvulcanized tread T to the drum 12 by feeding the preformed unvulcanized tread T from the stock portion. And supply.

  The drum 12 is a cylindrical forming drum that can be expanded and contracted, and includes a plurality of (in the figure, 10 pieces) segments (fan-shaped divided pieces in a side view) 13 that are arranged in a cylindrical shape in the circumferential direction of the drum, And an elastic band 14 disposed on the outer peripheral surface. The drum 12 includes a link connected to the segment 13, an expansion / contraction mechanism, and the like. The expansion / contraction means that synchronously expands / contracts the plurality of segments 13 and a rotation unit (each of which includes a motor, a rotational power transmission mechanism, and the like). (Not shown).

  The forming apparatus 10 rotates the drum 12 by a rotating means to rotate it around the axis line at a predetermined speed, winds the continuously supplied unvulcanized tread T around the elastic band 14, and rotates the drum 12 and unvulcanized. The supply of tread T is stopped. Subsequently, the rear end portions of the unvulcanized tread T are cut and joined to form an annular unvulcanized tread T. At that time, the plurality of segments 13 are displaced in advance by the expansion / contraction means, and the outer diameter of the drum 12 is smaller than the outer diameter (the outer diameter at the maximum diameter position) of the molded body to which the unvulcanized tread T is attached. Set to. Thus, the drum 12 is formed with an annular unvulcanized tread T having an inner diameter smaller than the outer diameter of the molded body on the outer periphery.

FIG. 3 is a main part side view showing a state in which an annular unvulcanized tread T is formed on the drum 12 of FIG. 2, and FIG. 3C shows an enlarged X range of FIG. 3B.
As shown in the figure, the annular unvulcanized tread T is held in contact with the outer peripheral surface of the elastic band 14 and supported by the plurality of segments 13 with the elastic band 14 interposed therebetween (see FIG. 3A). From that state, the forming apparatus 10 causes the plurality of segments 13 to undergo diameter expansion displacement (see FIG. 3B), and elastically deforms the elastic band 14 in contact with the outer peripheral surface according to the diameter expansion displacement of the segments 13. As a result, the elastic band 14 is expanded and expanded in diameter while filling the gaps between the segments 13, and the unvulcanized tread T on the outer peripheral surface of the elastic band 14 is expanded and deformed while maintaining the annular shape. In this way, the forming apparatus 10 expands the diameter of the drum 12 by the expansion / contraction means (expansion means), expands (unexpands) the annular unvulcanized tread T radially outward, and increases the inner diameter thereof. As will be described later, the diameter is increased to a predetermined diameter larger than the outer diameter of the molded body.

  Here, the elastic band 14 is an elastically deformable cylindrical member (here, a rubber band), and in order to prevent the unvulcanized tread T from adhering to the outer peripheral surface, Fine irregularities forming a mesh shape are formed. The elastic band 14 is arranged so as to surround the plurality of segments 13, and the inner peripheral surface always contacts the outer peripheral surface of the segment 13 and elastically deforms within the range in which the drum 12 can be expanded and contracted. At that time, if the friction between the inner peripheral surface and the segment 13 is large, the elastic band 14 (see FIG. 3C) is difficult to extend because the deformation of the portion L1 contacting the segment 13 is suppressed, and the portion L2 between the segments 13 becomes Relatively large deformation. In this case, the unvulcanized tread T is also affected by the deformation of the elastic band 14 in contact with the inner peripheral surface, and expands and expands in the same manner as the elastic band 14 and greatly expands and thins. The portions and the portions that extend slightly and have a small thickness change alternately occur along the circumferential direction. As a result, in the unvulcanized tread T, a thick portion and a thin portion are formed in order along the circumferential direction, resulting in variations in thickness and thickness uniformity.

  On the other hand, in the present embodiment, the elastic band 14 is made smaller in the friction coefficient of the inner peripheral surface in contact with the segment 13 than the friction coefficient of the outer peripheral surface where the annular unvulcanized tread T is formed. The surface is set to a friction coefficient capable of sliding between the segment 13 and the surface. Thereby, at the time of diameter expansion deformation, the elastic band 14 is smoothly deformed even in the portion L1 contacting the segment 13, and the whole is extended more uniformly, and the thickness of the unvulcanized tread T is reduced. The diameter is deformed to increase the uniformity of the thickness along the circumferential direction.

  Specifically, the elastic band 14 is provided with a low-friction member having a smaller friction coefficient than the outer peripheral surface and capable of elastically deforming to reduce the friction with the segment 13 on the inner peripheral surface of the elastic band 14. Can be ensured. Here, as the low friction member, a stretchable cloth made of knitted cotton, polyethylene terephthalate (PET) fiber or the like is provided on the inner peripheral surface. However, on the inner peripheral surface of the elastic band 14, the surface treatment for reducing the frictional force with respect to the contacting segment 13, for example, forming minute irregularities such as a line shape, a dot shape, a grain shape, a mesh shape, etc. Surface treatment may be performed to prevent adhesion with the surface. Further, as the surface treatment, the inner peripheral surface may be coated with a low-adhesive material (silicone compound, fluorine compound or the like) having low adhesion to the segment 13, or a combination of the respective treatments.

  The tire manufacturing apparatus 1 surrounds the outer periphery of the drum 12 with the annular holding means 20 (see FIG. 1) before expanding the diameter of the annular unvulcanized tread T via the elastic band 14 (or after expanding the diameter). The inner peripheral portion of the holding means 20 is disposed so as to face the outer periphery of the unvulcanized tread T. By this holding means 20, the unvulcanized tread T whose diameter has been expanded is detachably held from the outer peripheral side, the diameter of the drum 12 is reduced, and the unvulcanized tread T is detached from the drum 12 and maintained in the expanded diameter state. . In this state, the holding means 20 is moved to the molding drum 2 side that holds the molded body, and the unvulcanized tread T is disposed on the outer periphery of the molded body.

FIG. 4 is a side view of the holding means 20 for the unvulcanized tread T as viewed from the direction of the arrow Y in FIG. 1 and schematically shows the main part thereof. FIG. 4 shows a state in which the unvulcanized tread T is held by the holding means 20 and arranged on the outer peripheral side of the molded body H (the outer periphery is indicated by a dotted line) on the molding drum 2.
As shown in the figure, the holding means 20 includes a cylindrical frame 21, a moving means 22 of the frame 21 fixed to the lower surface of the frame 21, and a plurality of divided holdings provided on the inner diameter portion of the frame 21 that can be expanded and contracted. Member 30. In addition, the holding means 20 has expansion / contraction displacement means 23 that synchronously expands / contracts the plurality of divided holding members 30 and disposes the divided holding members 30 at a predetermined diameter position. The unvulcanized tread T having an arbitrary outer diameter within the displaceable range is held. The expansion / contraction displacement means 23 is composed of, for example, a piston / cylinder mechanism, or a link mechanism and a drive means. , Approach and separate from each other in the circumferential direction.

  The plurality of divided holding members 30 are divided into a plurality of portions in the circumferential direction, and have an annular shape as a whole with their ends opposed to each other, and are expanded or contracted in advance to a position that matches the outer periphery of the unvulcanized tread T in advance. The unvulcanized tread T is disposed along the circumferential direction. In addition, the plurality of split holding members 30 each have a radially inner holding surface (a surface facing the unvulcanized tread T) in contact with the outer peripheral surface of the opposing unvulcanized tread T to thereby form an unvulcanized tread. T is held in an expanded state. At the time of holding the unvulcanized tread T, the holding means 20 is configured so that when the plurality of divided holding members 30 are expanded and displaced, even in the separation range between the divided holding members 30 that are separated from each other in the circumferential direction due to the expanded diameter displacement, respectively. Holds the unvulcanized tread T. Therefore, the holding means 20 has a separation range holding member (not shown), thereby holding the unvulcanized tread T within the separation range, maintaining its position and diameter-expanding shape, and Shrinkage is suppressed, the amount of expansion and thickness variation in each range is reduced, and thickness uniformity is maintained.

FIG. 5 is an enlarged plan view showing the divided holding member 30 of the present embodiment, and schematically shows three divided holding members 30 viewed from the holding surface side of the unvulcanized tread T. FIG.
As shown in the figure, each of the divided holding members 30 has a rectangular plate shape having the same shape, and has a concave portion 31 at one end (right side in the figure) in the circumferential direction (left and right direction in the figure) and the other (left side in the figure). The convex part 32 is formed in the edge part of the direction, and is arrange | positioned adjacently along the circumferential direction. The projecting portion 32 is a projecting piece having a rectangular shape in plan view, and is formed to project from the center portion of the end portion of the divided holding member 30 by a predetermined length in the circumferential direction. On the other hand, the concave portion 31 has a rectangular shape in plan view that is slightly larger than the convex portion 32, is formed at the center of the end corresponding to the convex portion 32, and can accommodate the entire convex portion 32 therein. . In addition, the split holding member 30 corresponds to the concave portion 31 and the convex portion 32 so that the portions on both sides in the width direction (vertical direction in the figure) of the concave portion 31 form a rectangular shape in plan view having the same size as the convex portion 32. Is formed.

  As described above, the plurality of divided holding members 30 have the concave portion 31 provided at one end portion of the divided holding member 30 adjacent at each division position and the convex portion 32 provided at the other end portion. In addition to the main body portion between them, the unvulcanized tread T is also held on both sides in the width direction across the concave portion 31 and the convex portion 32. Further, at the time of the diameter reduction displacement (see FIG. 5A), the convex portion 32 is disposed in the opposing concave portion 31, and with the diameter expansion displacement (see FIG. 5B), the divided holding members 30 are gradually separated from each other, The convex portion 32 moves from the inside of the concave portion 31 to a separation range between the divided holding members 30 (range R in FIG. 5B). The separation range R is a range in which the adjacent divided holding members 30 (parts excluding the convex portions 32) are separated from each other in the circumferential direction due to the diameter expansion displacement, and the convex portions 32 of the divided holding members 30 are disposed, The unvulcanized tread T in the range R is retained. Accordingly, here, the convex portion 32 of the divided holding member 30 constitutes the separation range holding member of the holding means 20 described above.

  Further, in the present embodiment, a plurality (seven in this case) of adsorbing means 33 that adsorbs the unvulcanized tread T are uncured including both sides sandwiching the concave portions 31 of the divided holding members 30 and the convex portions 32. It is arranged on the holding surface of the tread T. The plurality of adsorbing means 33 are arranged at least on both sides of the concave portion 31 and the convex portion 32, and are arranged substantially evenly over the entire holding surface of the divided holding member 30. The suction means 33 is composed of a suction pad-like suction pad fixed to the holding surface, and is connected to an air supply / exhaust line penetrating the divided holding member 30 to respond to exhaust and air supply by the connected air supply / exhaust means. Then, the unvulcanized tread T is adsorbed and desorbed. The holding means 20 detachably adsorbs and holds the outer peripheral surface of the unvulcanized tread T by the plurality of adsorbing means 33 included in the divided holding member 30 and holds the unvulcanized tread T in the separation range R in a convex shape. It is held by one suction means 33 of the part 32.

  In addition, the holding means 20 has one or a plurality of (here, two) pressing means 34 at the center in the width direction of the divided holding member 30. The pressing means 34 is a pusher that presses the central portion in the width direction of the held unvulcanized tread T toward the inside in the radial direction. For example, the pressing means 34 moves forward and backward through the through hole of the divided holding member 30 and protrudes from the holding surface. It consists of a member and a piston / cylinder mechanism for advancing and retracting the pressing member. The holding means 20 advances and retracts the pressing means 34 of the plurality of divided holding members 30 in synchronization, and presses the unvulcanized tread T to be held. Thereby, the center part in the width direction of the unvulcanized tread T facing the outer periphery of the molded body H is pressed against a predetermined application position (here, the tire equator surface) set on the outer periphery of the molded body H. And crimp.

  Here, since the unvulcanized tread T is held around the central portion in the width direction by the holding means 20, depending on the width, the side portion may protrude outward from the divided holding member 30, and the width is wide. Indeed, the amount of protrusion of the side part increases. Along with this, the unvulcanized tread T has a side portion on the outer side in the width direction of the suction means 33 that hangs downward due to gravity, and the holding means 20 moves to the molding drum 2 side (see FIG. 1) in this state. Then, a side part may approach to the to-be-molded body H etc. and may contact. Therefore, the tire manufacturing apparatus 1 supports at least the side of the unvulcanized tread T on the side of the molded body H (front side in the movement direction) by the support means 40, and the position thereof is larger than the outer diameter of the molded body H. Positioned outside, the side portions are maintained at an inner diameter larger than the outer diameter of the molded body H.

FIG. 6 is a side view of the support means 40 on the side of the unvulcanized tread T as viewed from the direction of the arrow Y in FIG. 1, and schematically shows the main part. In FIG. 6, the support means 40 in different states is shown on each side across the left and right central plane M, and the state where the unvulcanized tread T is supported on the left side and the support is released on the right side. Show. FIG. 7 is an enlarged cross-sectional view showing a part of the support means 40 of FIG.
As shown in FIG. 6, the support means 40 includes a plurality of (here, six) support members 41 that support the unvulcanized tread T, a connecting member 42 to which each support member 41 is fixed, both members 41, It has the moving means 43 which moves 42 to the radial direction of the unvulcanized tread T, and the annular member 44 to which the moving means 43 was attached. In addition, the support means 40 is provided with a circular through portion at the center in the plurality of support members 41, and the molded body H can pass through the circular through portion.

  The plurality of support members 41 are plate-like members that contact along the inner peripheral surface of the side portion of the unvulcanized tread T, and are formed to be curved so as to form a cylindrical shape as a whole, along the circumferential direction, etc. Arranged at intervals. Further, the support member 41 is connected to the moving means 43 by the connecting member 42, and is simultaneously moved by the moving means 43 that operates in synchronism and arranged at a predetermined radial position. The moving means 43 is composed of, for example, a piston / cylinder mechanism, and moves the support member 41 along the radial direction by moving the piston rod forward and backward from the cylinder and via the connecting member 43 fixed to the tip thereof.

  The support means 40 causes the moving means 43 to bring the support member 41 closer from the inside in the radial direction of the unvulcanized tread T (see the right side in FIG. 6 and FIG. 7A) and abut against the inner peripheral surface of the unvulcanized tread T. (See left side of FIG. 6 and FIG. 7B). In this way, the support means 40 supports the side portion of the unvulcanized tread T held by the holding means 20 on the side of the molded body H, and moves in unison with the holding means 20 in this state. The tread T is disposed on the outer peripheral side of the molded body H. Thereafter, the support means 40 releases the support by separating the support member 41 from the side of the unvulcanized tread T, and the holding member is moved by a displacement mechanism (not shown) provided between the annular member 44 and the holding means 20. It is displaced in a direction away from 20 (right direction in FIG. 7A). As a result, the tire manufacturing apparatus 1 displaces the support member 41 outward in the width direction of the unvulcanized tread T, releases the holding of the unvulcanized tread T by the holding means 20 (see FIG. 4), and then unvulcanized. The tread T is disposed on the outer periphery of the molded body H.

  Next, the procedure and operation | movement which shape | molds an unvulcanized tire with this tire manufacturing apparatus 1, and each process of a tire manufacturing method are demonstrated. The following steps of tire molding are controlled by the control means 70 (see FIG. 1) and executed by causing each part of the apparatus to perform related operations at preset timings and conditions. Further, the control means 70 controls the holding means 20 and the support means 40 to hold the unvulcanized tread T and to support the side portions of the unvulcanized tread T as described above. The holding and supporting by 20, 40 are released. Therefore, as will be described later, the control means 70 includes a holding release means for releasing the holding of the unvulcanized tread T by the holding means 20 and an unvulcanized tread by the support means 40 according to the molding stage of the unvulcanized tire. And a support releasing means for releasing the support of the side portion of T.

  First, the tire manufacturing apparatus 1 molds the molded body H with the molding drum 2 (see FIG. 1), and holds the unvulcanized tread T in a shape before being pasted by, for example, expanding the central portion thereof. Further, the forming means 10 displaces a plurality of segments 13 (see FIG. 2) arranged in the circumferential direction of the drum 12 and disposes them at a predetermined diameter position. Wrap the sulfur tread T. The unvulcanized tread T is wound around the drum 12 at a predetermined rate (for example, 5 to 15%) shorter than the length of the outer periphery of the molded body H (the outer periphery of the maximum diameter position). An annular unvulcanized tread T having an inner diameter smaller than the outer diameter of the molded body H is formed on the outer periphery (the outer peripheral surface of the elastic band 14). Subsequently, the plurality of segments 13 are expanded and displaced, the drum 12 is expanded (see FIG. 3), and the elastic band 14 is elastically deformed in accordance with the expanded displacement of the segments 13 contacting the inner peripheral surface. As a result, the diameter of the annular unvulcanized tread T is increased by a predetermined ratio (for example, 13 to 17%), and the inner diameter thereof is increased larger than the outer diameter of the molded body H. Next, the expanded unvulcanized tread T is held by the holding means 20 and is removed from the drum 12.

FIG. 8 is a schematic view showing a manufacturing process of the unvulcanized tire following the holding of the unvulcanized tread T, and one side of the cross section in the width direction of the unvulcanized tread T and the molded body H and the vicinity thereof. The main part of the tire manufacturing apparatus 1 is extracted and shown.
Here, in this embodiment, the diameter expansion rate V is set between the inner diameter (D1 in FIG. 8A) of the unvulcanized tread T before diameter expansion and the outer diameter (D2 in FIG. 8B) of the molded body H. Then, the diameter of the annular unvulcanized tread T is expanded based on the set diameter expansion rate V. This diameter expansion rate V is calculated from the ratio of the inner diameter D1 of the unvulcanized tread T to the outer diameter D2 of the molded body H (V = 1−D1 / D2). Here, the inner diameter D1 of the unvulcanized tread T before being expanded is larger than the outer diameter D2 of the molded body H so that the unvulcanized tread T is expanded at a diameter expansion rate V of 5 to 15%. Is set. However, since the unvulcanized tread T is disposed so as to surround the molded body H, the unvulcanized tread T is expanded to an inner diameter (D3 in FIG. 8A) larger than the outer diameter D2 by a predetermined diameter (here, 20 mm). This expanded unvulcanized tread T is held and moved from the outer peripheral side by the holding means 20, and is disposed so as to face the outer periphery of the molded body H.

  In the arranging step, the divided holding member 30 (see FIG. 8A) divided in advance in the circumferential direction is expanded / contracted according to the outer diameter of the unvulcanized tread T, and concentrically with the drum 12, It arrange | positions on the outer peripheral side of the sulfur tread T. Subsequently, the plurality of divided holding members 30 actuate the suction means 33 to surround and hold the unvulcanized tread T whose diameter has been expanded. At the same time, the unvulcanized tread T is held by the adsorbing means 33 of the convex portion 32 even in the separation range R (see FIG. 5B) between the divided holding members 30 that are separated along with the diameter expansion displacement. Next, a plurality of support members 41 are brought into contact with the side of the held unvulcanized tread T on the side of the body to be molded H (the front side in the movement direction) by the support means 40, and the side is supported to be molded. The inner diameter D3 is maintained larger than the outer diameter D2 of the body H.

  The tire manufacturing apparatus 1 holds and supports the unvulcanized tread T as described above, and moves both means 20 and 40 integrally toward the molding drum 2 by the above-described disposing means so that the unvulcanized tread T is moved. Move. Thereby, the unvulcanized tread T is passed through the radially outer side of the molded body H from the side portion side supported by the support means 40 (see FIG. 8B), and the outer peripheral side (radially outer side) of the molded body H. The diameter is maintained in an expanded state up to a predetermined arrangement position, and is moved concentrically with the workpiece H. Further, the inner periphery of the unvulcanized tread T is opposed to the outer periphery of the molded body H, and the center of the unvulcanized tread T in the width direction and the position of the tire equatorial plane of the molded body H are aligned, The vulcanized tread T is disposed on the outer periphery of the molded body H. Next, after the arrangement of the unvulcanized tread T is completed, the support member 41 is separated from the side of the unvulcanized tread T facing the outer periphery of the molded body H, and the unvulcanized tread T by the support means 40 is removed. Release the side support. After the support by the support means 40 is released, the holding of the unvulcanized tread T by the holding means 20 is released.

  At this time, in this embodiment, first, the pressing means 34 (see FIG. 8C) provided in each divided holding member 30 is operated in synchronization, and the width of the unvulcanized tread T facing the outer periphery of the molded body H. The center part of the direction is pressed against a predetermined attaching position (here, the tire equator plane) set on the outer periphery of the molded body H. Thereby, the central part of the unvulcanized tread T is pressure-bonded to the outer peripheral surface of the molded body H (here, the belt B made of the cord C wound spirally) at a plurality of locations along the circumferential direction. Align and fix the positions of their central parts. After the pressing means 34 presses the central portion, the suction of the suction means 33 is stopped, and the holding of the unvulcanized tread T by the holding means 20 is released.

  The tire manufacturing apparatus 1 releases the unvulcanized tread T whose diameter has been expanded by releasing the holding of the unvulcanized tread T, and the outer periphery of the molded body H facing the unvulcanized tread T by the contraction force of rubber. Shrink toward Along with this, the unvulcanized tread T is contracted (reduced) radially inward and deformed toward the outer periphery of the molded body H (see FIG. 8D), and at least in the vicinity of the tire equatorial plane, the molded body H is formed. While abutting, it is deformed along the outer periphery.

  Subsequently, the tire manufacturing apparatus 1 releases the holding of the unvulcanized tread T facing the outer periphery of the molded body H by the holding means 20, and then moves the holding means 20 and the support means 40 from the molded body H. The molded body H is released by the molding drum 2. Next, the pair of pressing rollers 3R (see FIG. 8E) of the pressing means 3 are pressed against the outer peripheral surface of the unvulcanized tread T, and the pair of pressing rollers 3R are moved outward from the center in the width direction of the unvulcanized tread T. Move along the outer peripheral surface. The pressed unvulcanized tread T is pressed against the molded body H by the pressing roller 3R, the whole is stitched, and the unvulcanized tread T is brought into close contact with the outer shape of the molded body H. As a result, the inner periphery of the unvulcanized tread T is pressure-bonded to the outer periphery of the molded body H, and an unvulcanized tire is molded (manufactured). Thereafter, the molded unvulcanized tire is vulcanized to produce various tires such as a pneumatic tire.

  At the time of tire formation described above, in this embodiment, an annular unvulcanized tread T having an inner diameter D1 smaller than the outer diameter D2 of the molded body H is expanded to an inner diameter D3 larger than the outer diameter D2 of the molded body H. Keep the diameter. Further, the unvulcanized tread T is opposed to the outer periphery of the molded body H to release the holding of the unvulcanized tread T, and the expanded unvulcanized tread T is opposed by the inherent shrinkage force. It shrinks toward the outer periphery of the molding H to be performed. Therefore, the annular unvulcanized tread T can be deformed into a shape along the outer periphery of the molded body H without difficulty according to the contraction without the need to press and greatly squeeze and deform as in the conventional case.

  Along with this, the unvulcanized tread T can be uniformly and accurately attached to the molded body H by preventing the occurrence of wrinkles and undulations on the side portions. As a result, the occurrence of unevenness on the side portions can be suppressed, and the uniformity of the thickness can be increased by reducing the variation in thickness and appearance generated on the side portions of the unvulcanized tire. In particular, when a tire having a large diameter difference between the center part and the side part in the tire width direction, such as a tire for a motorcycle, is formed, the deformation amount of the unvulcanized tread T due to the pressing of the pressing roller 3R is reduced. The occurrence of surface irregularities can be effectively suppressed. In addition, when vulcanized tires are vulcanized, the surface of the tire can be easily molded and problems can be prevented, so it is possible to prevent appearance problems including irregularities and bares on the tire surface after vulcanization. However, the uniformity of the thickness along the circumferential direction of the tire can be improved to improve the uniformity.

  Therefore, according to the present embodiment, when the unvulcanized tire is molded, the unvulcanized tread T is contracted along the outer periphery of the molded body H regardless of the width and type of the unvulcanized tread T. In addition, the surface irregularities can be suppressed and the surface of the molded body H can be accurately attached. Moreover, the uniformity of the circumferential direction of the unvulcanized tread T affixed to the to-be-molded body H can be improved, and the uniformity of a tire can also be improved.

  Further, in the tire manufacturing apparatus 1, the side portion of the unvulcanized tread T is supported by the support means 40, and the unvulcanized tread T is disposed on the outer periphery of the molded body H from the supported side portion side. It can prevent reliably that the side part of the sulfur tread T contacts the to-be-molded body H. As a result, as described above, even when the side portion of the unvulcanized tread T protrudes from the holding means 20 and hangs down, the unvulcanized tread T can be smoothly disposed on the outer periphery of the molded body H, and these are unnecessary. Contact can be prevented and the placement work can be repeated accurately and accurately. At the same time, since various unvulcanized treads T having different widths can be held and arranged by one holding means 20 without exchanging the divided holding member 30, the versatility of the tire manufacturing apparatus 1 is improved, and Work efficiency can also be improved. Further, after pressing the center portion of the unvulcanized tread T to the molded body H by the pressing means 34, the holding of the unvulcanized tread T by the holding means 20 is released, so that the unvulcanized to the molded body H is released. Misalignment and fluctuation of the tread T can be prevented. As a result, the unvulcanized tread T can be accurately disposed by being contracted accurately toward the position where the molded body H is attached.

  On the other hand, when holding the unvulcanized tread T by the plurality of divided holding members 30 of the holding means 20 and holding the unvulcanized tread T as described above in the separation range R between the divided holding members 30, The unvulcanized tread T can be held more evenly along the circumferential direction. Further, the unvulcanized tread T in the separation range R can be maintained in a diameter-enlarged shape while maintaining the position, and the shrinkage of the unvulcanized tread T in the separation range R can be suppressed. Further, variation in thickness along the circumferential direction can be reduced, and thickness uniformity can be maintained. Accordingly, the unvulcanized tread T can be more uniformly and accurately attached to the outer periphery of the molded body H along the circumferential direction. At the same time, various unvulcanized treads T having different outer diameters can be held by one holding means 20 without changing the division holding member 30 while suppressing a decrease in thickness uniformity. It is possible to improve the versatility of the apparatus and improve the work efficiency.

  At that time, the unvulcanized tread T in the separation range R may be held when the divided holding member 30 is separated by providing a holding member different from the divided holding member 30 in the holding means 20. However, when the unvulcanized tread T in the separation range R is held by the convex portion 32 of the split holding member 30, the convex portion 32 that moves from the concave portion 31 to the separation range R without requiring a complicated mechanism or operation, The unvulcanized tread T can be held in accordance with the holding by the divided holding member 30. As a result, the holding means 20 and the tire manufacturing apparatus 1 can be prevented from becoming complicated, and the above-described effects associated with holding the separation range R can be obtained with a relatively simple configuration. Further, when the unvulcanized tread T is held on both sides of the split holding member 30 across the concave portion 31, the adjacent divided holding members 30 hold the unvulcanized tread T at positions close to each other in the circumferential direction. The unvulcanized tread T can be more evenly held along the circumferential direction. Furthermore, the split holding member 20 is provided with an adsorbing means 32 to adsorb and hold the unvulcanized tread T so that the unvulcanized tread T can be held and released smoothly and quickly without being damaged. Can be done.

  Here, in the tire manufacturing apparatus 1, the elastic band 14 (see FIG. 3) of the drum 12 has a smaller coefficient of friction on the inner peripheral surface in contact with the segment 13 than the outer peripheral surface, and when the drum 12 is expanded, As described above, the entire elastic band 14 is extended more evenly. Therefore, the unvulcanized tread T that expands similarly to the elastic band 14 can be expanded and deformed while reducing the variation in thickness, and the unvulcanized tread T can be made more uniform in the circumferential direction of the thickness. In this state, it can be uniformly attached to the outer periphery of the molded body H. Further, the inner peripheral surface of the elastic band 14 is subjected to a surface treatment for reducing the frictional force with respect to the segment 13, or the inner peripheral surface is an elastically deformable low friction member having a smaller coefficient of friction than the outer peripheral surface (for example, expandable and contractible). The friction coefficient of the inner peripheral surface can be reliably reduced. In addition, the state of the inner peripheral surface can be maintained at the same level for a long period of time, and the slip between the segment 13 at the time of diameter expansion can be reliably ensured.

  In this embodiment, the unvulcanized tread T is moved so as to be opposed to the outer periphery of the molded body H. However, the unvulcanized tread T is moved without moving the unvulcanized tread T. You may make it move to the inner peripheral side of T, and arrange | position them so that it may oppose. Further, the side portion of the unvulcanized tread T is supported by supporting the support member 41 of the support means 40 in contact with the inner peripheral surface, for example, by adsorbing and supporting the outer peripheral surface by a plurality of adsorbing means, etc. You may support by another support means. Further, the unvulcanized tread T may be a single rubber member molded from one type of rubber or a plurality of rubber members molded from a plurality of types of rubber. It may be formed and supplied to the drum 12, or a plurality of rubber members may be formed by combining the rubber members on the drum 12.

(Molding test of unvulcanized tire)
In order to confirm the effect of the present invention, the tire manufacturing apparatus 1 forms an unvulcanized tire as described above, and performs a test for evaluating the elongation and thickness variation and uniformity of the unvulcanized tread T. It was. In the test, first, the diameter of the drum 12 (see FIG. 3) on which the annular unvulcanized tread T was formed was expanded so that the inner diameter of the unvulcanized tread T was larger than the outer diameter of the molded body H. In the state, the elongation of the unvulcanized tread T was measured.

  At that time, a plurality of unit figures of a certain size are drawn on the outer circumferential surface of the unvulcanized tread T before diameter expansion and along the circumferential direction at the center in the width direction, and the diameter of the unvulcanized tread T is expanded. The circumferential length of each unit figure was measured before and after. Thereby, the elongation of each part of the unvulcanized tread T after the diameter expansion with respect to the diameter before the diameter expansion is obtained, and the positions where the ten segments 13 respectively contact the elastic band 14 and the positions between the segments 13 are not vulcanized. The elongation rate of the tread T was acquired, and its variation and uniformity were evaluated. In the test, a rubber band (hereinafter referred to as the elastic band 14 of the embodiment) provided with a knitted fabric on the inner peripheral surface is used as the elastic band 14, and the friction coefficient of the inner peripheral surface is smaller than that of the outer peripheral surface. Thus, the frictional force on the segment 13 was reduced. On the other hand, as an elastic band of the comparative example, two types of rubber bands made of rubber having a flat inner peripheral surface and a friction coefficient larger than that of the outer peripheral surface are used to expand the diameter of the unvulcanized tread T. Each elongation was measured and compared with the results of the elastic band 14 of the example.

FIG. 9 is a graph showing the elongation rate of the unvulcanized tread T after the diameter expansion. The horizontal axis is a position along the circumferential direction of the unvulcanized tread T (the segment in the figure is the position of the segment 13, and the space between the segments 13 is the segment 13). The vertical axis indicates the expansion rate (%) at each position.
As a result of the test, in the elastic band of the comparative example (see FIG. 9A), the elongation rate increases at the position between the segments 13 with respect to the position of the segment 13 where the elongation rate is small, and extends along the circumferential direction. The variation was about 6%. On the other hand, in the elastic band 14 (see FIG. 9B) of the embodiment, there is no difference in the elongation rate between the position of the segment 13 and the position between the segments 13, and the variation in the elongation rate is reduced to about 1.8%. The uniformity was high. Thus, in the elastic band 14 of the embodiment, the elastic band 14 can be extended more uniformly than the elastic band of the comparative example, and the unvulcanized tread T can be extended more uniformly to reduce the thickness variation. It was found that the uniformity can be increased.

  Next, the unvulcanized tread T expanded in diameter by the elastic band 14 of the embodiment is held by the holding means 20 (see FIGS. 4 and 5), and the unvulcanized tread T is opposed to the outer periphery of the molded body H. After the release, the elongation of the unvulcanized tread T (see FIG. 8D) in a contracted state was measured on the molded body H. In this test, the elongation of each part of the unvulcanized tread T after shrinkage with respect to the diameter before expansion by the drum 12 was determined by measuring the circumferential length of the unit graphic in the same manner as described above. Thereby, the elongation rate of the width direction center part of the unvulcanized tread T was acquired at a plurality of positions along the circumferential direction, and the variation and uniformity were evaluated. Further, here, the holding means 20 of the embodiment is provided with a divided holding member 30 divided into 11 in the circumferential direction, and the unvulcanized tread T is held even in the convex portion 32 located in the separation range R. This was compared with the case where the unvulcanized tread T was held by the holding means.

FIG. 10A is a side view showing the main part of the holding means of the comparative example, and FIG. 10B is an enlarged plan view showing the divided holding member of the comparative example.
The holding means 80 (see FIG. 10A) of the comparative example is provided with divided holding members 81 divided into six in the circumferential direction, and the unvulcanized tread T is held by the holding surfaces on the inner side in the radial direction. Further, the divided holding member 81 (see FIG. 10B) of the comparative example is linearly divided at the dividing position and formed into a rectangular plate shape having no concave portion or convex portion, and the unvulcanized tread T is formed by a plurality of adsorbing means 82. Adsorb and hold. Thus, the divided holding member 81 of the comparative example is divided into a smaller number than the divided holding member 30 of the embodiment, and when the divided holding members 81 are separated from each other, the unvulcanized tread T in the separated range is not held. It has become.

FIG. 11 is a graph showing the elongation rate of the unvulcanized tread T after shrinkage, where the horizontal axis indicates the position along the circumferential direction of the unvulcanized tread T, and the vertical axis indicates the elongation rate (%) at each position. Yes. FIG. 11A shows changes in the elongation rate of the three unvulcanized treads T held by the holding unit 80 of the comparative example, and FIG. 11B shows the four unvulcanized treads T held by the holding unit 20 of the example. This shows the change in elongation rate.
As a result of the test, in the holding means 80 (see FIG. 11A) of the comparative example, as the unvulcanized tread T between the divided holding members 81 contracts, the unvulcanized tread T after contraction also on the molded body H. A variation of about 3.5 to 5.7% occurred in the elongation rate along the circumferential direction. In addition, the elongation rate decreased at a position corresponding to between the divided holding members 81 (the valleys in FIG. 11A), and the elongation rate repeatedly changed in a zigzag shape along the circumferential direction.

  On the other hand, in the holding means 20 (see FIG. 11B) of the example, the change in the elongation rate of the unvulcanized tread T is reduced, and the variation in the elongation rate is reduced to about 2.6 to 3.2% and uniform. The nature became high. Thus, in the holding means 20 of the embodiment, the unvulcanized tread T can be held even in the separation range R and can be held more evenly along the circumferential direction, and the extension amount and thickness of the unvulcanized tread T can be held in the circumferential direction. It was found that the uniformity along the thickness can be maintained by reducing the variation along the line. Further, it was found that the unvulcanized tread T can be adhered to the molded body H more uniformly and accurately.

  In addition to the above tests, the tire manufacturing apparatus 1 expands the unvulcanized tread T at three diameter expansion ratios V (5, 10, 15%), and affixes the unvulcanized tread T to the molded body H. Was molded to produce tires (hereinafter referred to as Examples 1, 2, and 3). Further, according to the above-described conventional tire manufacturing method (see FIG. 13), the unvulcanized tread T is not shrunk (expansion ratio V = 0%), but is pressed and squeezed to deform the outer peripheral surface of the molded body H. A tire (hereinafter referred to as a conventional product) was manufactured by molding an unvulcanized tire. A plurality of tread thicknesses of the embodiment products and the conventional products are respectively provided along the tire circumferential direction at the center portion (tire equatorial plane), the middle portion (1/4 point), and the end portion (hump portion) in the width direction. Measurements were made at different locations, and their variations were compared. At that time, the difference between the maximum measured value and the minimum measured value of the thickness is calculated at the central part, the intermediate part and the end part, respectively, to obtain the variation in the thickness in the circumferential direction in each part, and the thickness is compared by comparing them. The uniformity of thickness was evaluated.

  Table 1 shows the variation in the thickness of the implemented product and the conventional product. Each variation is represented by an index where the variation at the end of the conventional product is 1, and the smaller the value, the smaller the variation. In addition, when molding an unvulcanized tire, wrinkles occurred on the side portions of the unvulcanized tread T in the conventional product, but in the products 1, 2, and 3, no wrinkles occurred on the side portions. The vulcanized tread T was deformed along the outer periphery of the molded body H.

FIG. 12 is a graph showing variations in the thickness of the tread between the actual product and the conventional product.
As shown in the drawing, in the products 1, 2, and 3 of the conventional product, the end variation was as small as 0.8, 0.6, and 0.6, and the uniformity was high. In addition, it was found that in the products 1, 2, and 3 as a whole, the variation was smaller than that of the conventional product, and the uniformity of the thickness of the tread along the circumferential direction was high. In particular, it was found that the implementation product 2 (diameter expansion rate V = 10%) had less variation than the other implementation products 1 and 3, and the thickness uniformity was the highest.

  Subsequently, these conventional products and the implementation products 1, 2, and 3 were attached to the rear side of the motorcycle, and an actual vehicle test was performed in which a test course on an uneven road surface and a good road surface was run. Conventional products and execution products 1, 2, and 3 are radial ply tires for motorcycles having a tire size of 190 / 55R17 defined by JATMA YEAR BOOK (2009, Japan Automobile Tire Association Standard), and the internal pressure was adjusted to 250 kPa. In the test, when traveling under the same conditions, the magnitude of longitudinal vibration (tire shock absorption) was evaluated with a maximum of 10 points. Table 2 shows the evaluation results.

  As a result of the test, as shown in Table 2, the shock absorbency on the uneven road surface is as high as 6 for the implementation products 1, 2 and 3 compared to 5.5 for the conventional product, Longitudinal vibration was small. Also, the shock absorption on the good road surface was 6, 7.5, and 7.3, which were all higher in the implementation products 1, 2, and 3 than in the conventional product 5. As a result, in the working products 1, 2, and 3 (particularly the working product 2), the thickness uniformity in the circumferential direction of the tread is increased, and as the tire uniformity is improved, the longitudinal vibration during traveling is increased. It turned out to be smaller.

  From the above results, according to the present invention, when the unvulcanized tire is molded, the unvulcanized tread T is shrunk along the outer periphery of the molded body H, and the unevenness of the surface is suppressed to suppress the surface of the molded body H. It has been proved that the uniformity of the tire can be improved by being applied to the outer periphery with high accuracy and improving the uniformity in the circumferential direction of the unvulcanized tread T attached to the molded body H.

  DESCRIPTION OF SYMBOLS 1 ... Tire manufacturing apparatus, 2 ... Molding drum, 3 ... Pressing means, 3R ... Pressing roller, 10 ... Unvulcanized tread forming apparatus, 11 ... Unvulcanized tread Supply means, 12 ... drum, 13 ... segment, 14 ... elastic band, 20 ... holding means, 21 ... frame, 22 ... moving means, 23 ... expansion / contraction displacement means, 30 ... Divided holding member, 31 ... Concave part, 32 ... Convex part, 33 ... Adsorption means, 34 ... Pressing means, 40 ... Support means, 41 ... Support member, 42 ... Connecting member, 43 ... Moving means, 44 ... Ring member, 70 ... Control means, 71 ... MPU, 72 ... ROM, 73 ... RAM, H ... Covered Molded body, R: separation range, T: unvulcanized tread.

Claims (5)

A tire manufacturing apparatus for forming an unvulcanized tire by attaching an unvulcanized tread to the outer periphery of a molded body,
An expandable / contractible drum in which an annular unvulcanized tread is formed on the outer periphery;
A diameter expanding means for expanding the diameter of the drum and expanding the diameter of the annular unvulcanized tread;
Holding means for holding the unvulcanized tread expanded in diameter;
An arrangement means for arranging the unvulcanized tread held by the holding means so as to oppose the outer periphery of the molded body;
Holding release means for releasing the holding by the holding means of the unvulcanized tread facing the outer periphery of the molded body;
A pressing means for pressing the unvulcanized tread released from holding by the holding means against the molded body, and crimping and bonding to the outer periphery of the molded body,
The drum has a plurality of segments that can be expanded and contracted disposed in the circumferential direction of the drum, and an elastic band that is disposed so as to surround the plurality of segments, and a friction coefficient between the inner peripheral surface of the elastic band that contacts the segment and the segment The tire manufacturing apparatus according to claim 1, wherein the elastic band is allowed to slide with respect to the segment when the elastic band expands and deforms as the segment expands . In the tire manufacturing apparatus according to claim 1,
A tire manufacturing apparatus, wherein an inner peripheral surface of an elastic band is subjected to a surface treatment for reducing a frictional force with respect to a contacting segment. In the tire manufacturing apparatus according to claim 1,
Elastic band, a tire manufacturing apparatus characterized by comprising an elastically deformable friction members reduce frictional forces for the segment in contact with the inner circumferential surface. In the tire manufacturing apparatus according to claim 3,
Tire production apparatus, wherein the friction member is a stretchable fabric. A tire manufacturing method for forming an unvulcanized tire by attaching an unvulcanized tread to the outer periphery of a molded body,
Forming an annular unvulcanized tread having an inner diameter smaller than the outer diameter of the molded body on the outer peripheral surface of the elastic band surrounding the plurality of segments arranged in the circumferential direction of the drum;
A step of expanding and displacing a plurality of segments;
A step of elastically deforming the elastic band according to the expansion displacement of the segment in contact with the inner peripheral surface, and expanding the inner diameter of the annular unvulcanized tread to be larger than the outer diameter of the molded body;
A step of holding the unvulcanized tread that has been expanded in diameter and facing the outer periphery of the molded body; and
Releasing the retention of the unvulcanized tread and shrinking the unvulcanized tread toward the outer periphery of the opposite object to be molded; and
Pressing the shrunk unvulcanized tread against the molded body, and pressing and pasting the unvulcanized tread to the outer periphery of the molded body,
The friction coefficient between the inner peripheral surface and the segments of the elastic band in contact with the segment, when expanded deformation of the elastic band associated with the diameter of the segments, characterized in that the possible slip values for segments Tire manufacturing method.

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