Tire manufacturing method and tire manufacturing device

Abstract

A method for manufacturing a tire in which a bead wire is adhered to the outer surface of a tire constituent member that is supported by a core from the inside and is configured to include unvulcanized rubber, the method comprising pressing the bead wire against the outer surface in parallel with the axis of rotation of the core, and pressing the bead wire against the outer surface in parallel with the axis of rotation of the core. The bead wires move in the radial direction of the core in a parallel state and are adhered in a spiral shape, thereby forming a bead.

Description

Technical Field

[0001] The present disclosure relates to a tire manufacturing method and a tire manufacturing device. Background Art

[0002] As a tire, a tire described in Japanese Patent Application Laid-Open No. 6-171306 is known. Summary of the invention

[0003] Problem that the invention aims to solve

[0004] The present disclosure provides a tire manufacturing method and a tire manufacturing apparatus capable of suppressing the variation in the inner diameter of a bead.

[0005] Solutions for solving problems

[0006] The first scheme is a method for manufacturing a tire in which a bead wire is adhered to the outer side surface of a tire constituent member that is supported from the inside by a core and is composed of unvulcanized rubber, wherein the bead wire is pressed against the outer side surface parallel to the rotation axis of the core, and the bead wire is moved in the radial direction of the core while maintaining a parallel state and adhered in a spiral shape, thereby forming a bead.

[0007] The tire manufacturing method according to a second aspect is the tire manufacturing method according to the first aspect, wherein the pressing is performed by a sticking roller supported by a piston rod of a cylinder provided parallel to the rotation axis.

[0008] A tire manufacturing method according to a third aspect is the tire manufacturing method according to the first aspect or the second aspect, wherein a pressing force of pressing the bead wire against the outer surface is within a range of 3N to 100N.

[0009] A tire manufacturing method according to a fourth aspect is the tire manufacturing method according to the first aspect, wherein the tire constituent member is a carcass ply in which a plurality of cords arranged parallel to each other are coated with unvulcanized rubber.

[0010] The tire manufacturing device of the fifth scheme comprises: a core that is capable of rotating and supports from the inner side a tire constituent component that contains unvulcanized rubber; a pressing device that presses the tire bead wire sent out from a wire supply portion against the outer side surface of the tire constituent component in parallel with the rotation axis of the core; and a moving device that enables the pressing device to move in the radial direction of the core while maintaining the above-mentioned parallel state.

[0011] Effects of the Invention

[0012] According to the present disclosure, it is possible to provide a tire manufacturing method and a tire manufacturing apparatus capable of suppressing variations in the inner diameter of the bead. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 1 is a cross section in the tire width direction showing a bead of a pneumatic tire manufactured by the tire manufacturing apparatus according to one embodiment of the present disclosure.

[0014] Figure 2 It is a front view showing the bead.

[0015] Figure 3 It is a perspective view showing a schematic structure of a tire manufacturing apparatus according to one embodiment of the present disclosure.

[0016] Figure 4 This is a perspective view schematically showing a robot used in the tire manufacturing apparatus according to one embodiment of the present disclosure.

[0017] Figure 5 It is shown that it can be applied to Figure 3 A perspective view of the end effector of the robot is shown.

[0018] Figure 6 2 is a diagram showing a drive system for driving an air cylinder.

[0019] Figure 7 is for Figure 5 The end effector shown schematically shows a side view of a discharge portion of the end effector from a horizontal perspective.

[0020] Figure 8 It is a schematic diagram showing the use of Figure 3 The robot shown is a perspective view of an example of installing a bead wire on one side surface of a tire component.

[0021] Fig. 9 It is a cross-sectional view of the carcass ply showing a state where the bead wire is pressed against the carcass ply.

[0022] Fig.10 The comparative example is a cross-sectional view of the carcass ply showing a state where the bead wire is pressed against the carcass ply. DETAILED DESCRIPTION

[0023] Hereinafter, a tire manufacturing apparatus 100 for manufacturing a green tire M according to an embodiment of the present disclosure and a pneumatic tire 10 manufactured by vulcanizing and molding the green tire M formed using the tire manufacturing apparatus 100 will be described with reference to the drawings.

[0024] In the drawings, the arrow A direction indicates the radial direction of a core AM and a pneumatic tire 10 described later, and the arrow B direction indicates the axial direction of the core AM and the pneumatic tire 10 .

[0025] Figure 1The bead portion 12 of the pneumatic tire 10 is shown as being obtained by vulcanization molding an unvulcanized green tire manufactured using a tire manufacturing apparatus 100 according to the present embodiment described later.

[0026] The pneumatic tire 10 includes a carcass ply 14 that spans one bead portion 12 and the other bead portion 12 (between the Figure 1 As an example, the carcass ply 14 is a carcass ply of a conventional structure in which a plurality of carcass cords arranged parallel to each other are covered with rubber, as is used in a so-called radial tire.

[0027] A bead 16 formed of a bead wire 8 is embedded in the bead portion 12, and the carcass ply 14 is wound from the inner side to the outer side of the tire in the bead 16. In addition, a bead filler 19 is provided on the outer side of the bead 16 in the tire radial direction.

[0028] like Figure 1 As shown, the inner liner 18 is arranged inside the carcass ply 14 in the tire axial direction (the direction of arrow B), and the outer rubber member 108 is arranged outside the carcass ply 14 in the tire axial direction.

[0029] In the pneumatic tire 10 of the present embodiment, the tire structure other than the bead portion 12 is the same as that of a normal pneumatic tire, and a detailed description thereof will be omitted. In addition, the normal pneumatic tire referred to here also includes a run-flat tire.

[0030] (Tire manufacturing equipment)

[0031] Next, a tire manufacturing apparatus 100 for manufacturing a green tire M before vulcanization molding used for the pneumatic tire 10 of the present embodiment will be described below.

[0032] like Figure 3 As shown, the tire manufacturing device 100 of the present embodiment has a robot 110 as an example of a mobile device, a wire supply unit 120 that supplies the bead wire 8 to the robot 110, a hanger 130 arranged between the robot 110 and the wire supply unit 120, an object support unit 140 that supports the raw tire M, and a control unit (robot control unit) 150 that controls the robot 110 to install the bead wire 8 on the raw tire M.

[0033] In the present embodiment, the wire supply unit 120 includes a rotating drum 121 for winding and storing the bead wire 8. In the present embodiment, the bead wire 8 wound on the rotating drum 121 is covered with a covering member 8a for protecting the bead wire 8 from damage or the like.

[0034] The tire manufacturing apparatus 100 further includes a covering material collecting unit 160 . The covering material collecting unit 160 collects the covering material 8 a removed from the bead wire 8 drawn out from the wire supply unit 120 .

[0035] The hanger 130 can remove the curling tendency remaining in the bead wire 8, the residual stress remaining in the bead wire 8, or both. In the present embodiment, the hanger 130 includes a support 131, a fixed roller 133 rotatably fixed to the support 131, and a sliding roller 132 rotatably and slidably provided to the support 131. The bead wire 8 is wound between the fixed roller 133 and the sliding roller 132. The curling tendency of the bead wire 8 can be removed by moving the fixed roller 133 and the sliding roller 132 away from each other.

[0036] like Figure 4 As shown, the robot 110 has an end effector 20 described later. In the present embodiment, the robot 110 has a robot arm 112 including a joint 111. The end effector 20 is mounted on the top of the robot arm 112. In addition, in the present embodiment, the movement of the robot 110 is controlled by a control unit 150. As a specific example of the control unit 150, a computer can be cited. The movement of the robot 110 can be controlled based on a program installed in the computer, for example.

[0037] The robot 110 includes a robot arm 112 having at least one joint 111 and an end effector 20. In this embodiment, the end effector 20 is mounted on a top end E112 of the robot arm 112.

[0038] The robot 110 has more than six axes of freedom. In the present embodiment, the robot 110 is a six-axis robot. The robot arm 112 has a first arm 112a, a second arm 112b, a third arm 112c, a fourth arm 112d, a fifth arm 112e, a sixth arm 112f, and a seventh arm 112g. The six-axis robot has six joints (111a to 111f).

[0039] The first joint 111a connects the second arm 112b to the first arm 112a in a rotatable manner, for example. The second joint 111b connects the third arm 112c to the second arm 112b in a swingable manner in the front-back direction, for example. The third joint 111c connects the fourth arm 112d to the third arm 112c in a swingable manner in the up-down direction, for example. The fourth joint 111d connects the fifth arm 112e to the fourth arm 112d in a rotatable manner, for example. The fifth joint 111e connects the sixth arm 112f to the fifth arm 112e in a swingable manner in the up-down direction. The sixth joint 111f connects the seventh arm 111g to the sixth arm 112f in a rotatable manner, for example. The top end of the seventh arm 111g constitutes the top end E112 of the robot arm 112. The end effector 20 can be mounted on the top end of the seventh arm 111g.

[0040] Therefore, in the XYZ axis coordinate system, the robot 110 has degrees of freedom in three linear directions: the X-axis direction, the Y-axis direction, and the Z-axis direction, and has degrees of freedom in three axial directions: the direction around the X-axis, the direction around the Y-axis, and the direction around the Z-axis.

[0041] Here, the X-axis, the Y-axis, and the Z-axis are axes that are orthogonal to each other. According to the present embodiment, for example, the Z-axis can be set in a manner parallel to the vertical direction. In addition, according to the present embodiment, the X-axis can be set in a manner parallel to the tire center axis when the tire center axis is included in the horizontal plane. Moreover, according to the present embodiment, the Y-axis can be set in a manner parallel to the tire width direction center line when the tire width direction center line is observed along the horizontal plane in a state where the tire center axis is included in the horizontal plane.

[0042] like Figure 3 As shown, the tire manufacturing device 100 includes an object driving unit 141 for rotating the core AM and a control unit (object driving unit control unit) 150 for controlling the object driving unit 141. The core AM supports the tire components described later from the inside. The object driving unit 141 is provided on the object supporting unit 140. In this embodiment, the operation of the object driving unit 141 is controlled by the control unit 150.

[0043] In the present embodiment, the robot 110 and the object driving unit 141 are controlled by a common control unit 150 .

[0044] The object driving unit 141 includes an object rotation driving unit 141a for rotating the core AM supporting the raw tire M. The object rotation driving unit 141a can rotate the core AM around the rotation axis O141 set horizontally. In the present embodiment, the object rotation driving unit 141a can rotate the core AM around the rotation axis O141 at a predetermined angle according to the command from the control unit 150.

[0045] The control unit 150 controls the position of the robot 110 so that the end effector 20 is located at a position corresponding to the rotation angle of the raw tire M. The robot 110 can move the end effector 20 to a target position corresponding to the rotation angle of the core AM according to a command from the control unit 150 .

[0046] exist Figure 5 , the end effector 20 of one embodiment of the present disclosure is schematically shown in a state where the second support portion 24b of the end effector 20 is in a normal position. Here, the normal position refers to a position in which the second support portion 24b is positioned in such a manner that the later-described bonding roller 23a is located on the upper side and the bonding roller 23a faces one side of the raw tire M (the side opposite to the object driving portion 141 side).

[0047] In addition, in the step of attaching the bead wire 8 described later, the robot 110 holds the attachment roller 23 a in the direction in which the rotation axis of the attachment roller 23 a is oriented in the vertical direction.

[0048] The end effector 20 includes a joint portion 21 , an introduction portion 22 for introducing the bead wire 8 , a discharge portion 23 for discharging the bead wire 8 introduced from the introduction portion 22 , and a support portion 24 for supporting the joint portion 21 , the introduction portion 22 , and the discharge portion 23 .

[0049] The support portion 24 includes a first support portion 24 a where the joint portion 21 and the introduction portion 22 are arranged with a gap therebetween, and a second support portion 24 b where the discharge portion 23 is arranged.

[0050] The second support portion 24b is connected to the first support portion 24a in such a manner that the extension axis O2 of the second support portion 24b intersects the extension axis O1 of the first support portion 24a and the second support portion 24b is located on the side opposite to the joint portion 21 across the first support portion 24a. Figure 4 As shown, the joint portion 21 can be attached to the top end of the seventh arm 112g, that is, the top end E112 of the robot arm 112.

[0051] like Figure 5 As shown, the introduction part 22 introduces the bead wire 8 into the end effector 20. In the present embodiment, the introduction part 22 has an inlet guide roller 22a. The inlet guide roller 22a is installed in a freely rotatable manner relative to the first support part 24a. The inlet guide roller 22a can guide the bead wire 8 into the end effector 20 by winding the bead wire 8. Thus, the bead wire 8 is introduced into the end effector 20 by the inlet guide roller 22a.

[0052] Reference numeral 25 denotes a linear member introducing portion for introducing the bead wire 8 introduced from the introducing portion 22 into the end effector 20. The linear member introducing portion 25 is disposed on the first supporting portion 24a.

[0053] In this embodiment, the linear member introduction portion 25 includes a feed roller 25a that can rotate relative to the first support portion 24a, a pinch roller 25b that can rotate relative to the first support portion 24a and can slide relative to the first support portion 24a, and a pinch roller actuator 25c for moving the pinch roller 25b. The feed roller 25a can be rotated by a drive source such as a servo motor.

[0054] The pinch roller 25b is arranged to be freely rotatable relative to the first support portion 24a. The pinch roller actuator 25c can press the pinch roller 25b against the feed roller 25a by pressing the pinch roller 25b toward the feed roller 25a. As a result, the bead wire 8 sandwiched between the feed roller 25a and the pinch roller 25b can be introduced into the end effector 20.

[0055] The pinch roller actuator 25c can separate the pinch roller 25b from the feed roller 25a by moving the pinch roller 25b away from the feed roller 25a. Thus, the pressure on the bead wire 8 between the feed roller 25a and the pinch roller 25b can be adjusted or released.

[0056] Reference numeral 26 denotes a tension control unit for controlling the tension of the bead wire 8. The end effector 20 of the present embodiment has a tension control unit 26 in the first support unit 24a, and specifically, the tension control unit 26 is located at a position closer to the second support unit 24b than the introduction unit 22. Specifically, the tension control unit 26 is located at a position closer to the downstream side of the bead wire 8 in the feeding direction than the introduction unit 22, and further, in the present embodiment, is located at a position closer to the downstream side of the bead wire 8 in the feeding direction than the linear member introduction unit 25.

[0057] The tension control unit 26 can remove the curling tendency remaining in the bead wire 8, the residual stress remaining in the linear component, or both, for example, by changing the winding direction of the bead wire 8, or by changing the distance when the bead wire 8 is wound around two rollers as the tension adjustment arm 26c described later, or by both.

[0058] Specifically, the tension control unit 26 aims to suppress tension disturbance caused by unwinding of the wire supply unit 120 or operation of the hanger 130. This can suppress the influence (for example, the above-mentioned residual stress) and positional deviation during winding that may be caused by tension disturbance.

[0059] In the present embodiment, the tension control unit 26 includes a dancer roller 26a and a guide roller 26b that wind up the bead wire 8 fed from the linear member introduction unit 25, and a dancer arm 26c that supports the dancer roller 26a so that the dancer roller 26a can rotate freely. The bead wire 8 is wound around the dancer roller 26a. In the present embodiment, the tension of the bead wire 8 can be controlled by, for example, changing the position of the dancer roller 26a corresponding to the opening angle of the dancer arm 26c. The bead wire 8 whose tension is controlled is fed to the discharge unit 23 through the tension control unit 26.

[0060] The discharge unit 23 further delivers the bead wire 8 delivered from the tension control unit 26 toward the core AM. In the present embodiment, the discharge unit 23 has a sticking roller 23a. The sticking roller 23a is arranged at the top end portion of a piston rod 23bL of a cylinder 23b described later so as to be freely rotatable. The sticking roller 23a and the cylinder 23b are an example of a pressing device of the present embodiment.

[0061] A peripheral groove is formed on the outer peripheral surface of the bonding roller 23a. Figure 6 ) The parts on both sides of the roller axis that hold the bead wire 8.

[0062] The sticking roller 23a can deliver the bead wire 8 moving in the end effector 20 to the outside of the end effector 20. Therefore, if the sticking roller 23a is pressed against a tire component constituting the raw tire M described later, the bead wire 8 delivered from the sticking roller 23a can be attached to the tire component.

[0063] Therefore, when the core AM is rotated in a state where the sticking roller 23 a is pressed against the tire component, the bead wire 8 can be sequentially stuck to the outer side surface of the tire component.

[0064] As described later, in the present embodiment, the tire constituent member is the unvulcanized carcass ply 14. In the unvulcanized carcass ply 14, a plurality of carcass cords arranged parallel to each other are covered with unvulcanized rubber.

[0065] Reference Figure 3 To explain, in the tire manufacturing apparatus 100 of the present embodiment, when the bead wire 8 is attached to the outer side surface of the tire component, the core AM to which the tire component is attached is sequentially rotated at a predetermined angle.

[0066] In the tire manufacturing apparatus 100 of the present embodiment, the position of the robot 110 is controlled to a predetermined position according to the rotation angle of the raw tire M so that the sticking roller 23a of the end effector 20 is arranged at the target position of the tire component to which the bead wire 8 is to be stuck.

[0067] In the present embodiment, the position at which the bead wire 8 is wound around the outer side surface of the tire component is determined by the position of the sticking roller 23a of the end effector 20. Figure 5 As shown, in the end effector 20 of the present embodiment, the sticking roller 23a is arranged at a position where a material passing position P for discharging the bead wire 8 is located on a rotation center axis O3 of a driving rotating portion 29 described later.

[0068] like Figure 5As shown, the discharge unit 23 has a cylinder 23b for contacting and separating the sticking roller 23a with respect to the core AM. When sticking the bead wire 8 to the tire component, the cylinder 23b is maintained by the robot 110 so that its axis is parallel to the rotation axis O141 of the core AM.

[0069] The cylinder 23b pushes the attaching roller 23a toward the tire component in parallel with the rotation axis O141 of the core AM, in other words horizontally, by protruding the piston rod 23bL, so that the bead wire 8 supported by the attaching roller 23a can be horizontally pressed toward the tire component.

[0070] In addition, the air cylinder 23b can separate the sticking roller 23a from the tire component by moving the sticking roller 23a away from the tire component. Thus, the pressing force of the bead wire 8 on the tire component can be adjusted or released.

[0071] like Figure 6 As shown, the air cylinder 23b is connected to the pressure sensors 172A, 172B, the pressure regulating and switching valve 174 and the air compressor 176 via the pipe 170. The air compressor 176, the pressure sensors 172A, 172B and the pressure regulating and switching valve 174 are connected to the control unit 150, and the control unit 150 controls the pressure regulating and switching valve 174 to supply compressed air of a preset specified pressure to the air cylinder 23b.

[0072] Thereby, the bead wire 8 supported by the sticking roller 23a can be pressed against the tire constituent member with a predetermined pressing force.

[0073] Furthermore, in the present embodiment, the pressing force of the bead wire 8 can be adjusted to, for example, 3N or more and 100N or less by adjusting the pressure of the compressed air.

[0074] like Figure 5 As shown, reference numeral 27 is a cutting portion for cutting the bead wire 8 fed from the discharge portion 23. In the present embodiment, the cutting portion 27 is provided on the first support portion 24a. In the present embodiment, the cutting portion 27 includes a cutter 27a for cutting the bead wire 8 and an actuator 27b for telescopically moving the cutter 27a.

[0075] Reference numeral 28 denotes an information acquisition unit for obtaining peripheral information of the raw tire M. The end effector 20 of the present embodiment includes the information acquisition unit 28 on the second support portion 24b. Specifically, the end effector 20 includes the information acquisition unit 28 at a position on the distal end side of the second support portion 24b.

[0076] The information acquisition unit 28 collects information about the periphery of the raw tire M (tire components). Examples of the periphery information of the raw tire M (hereinafter also referred to as "raw tire periphery information") include the position and shape of the tire components, the position of the bead wire 8, and the like. The end effector 20 includes the information acquisition unit 28 on the second support portion 24b, and thus can attach the bead wire 8 based on the periphery information of the raw tire M obtained by the information acquisition unit 28.

[0077] In addition, an image sensor can be cited as the information acquisition unit 28 , for example. In the present embodiment, the raw tire peripheral information obtained by the information acquisition unit 28 is input to the control unit 150 .

[0078] The control unit 150 can control the robot 110 and the object support unit 140 based on the raw tire periphery information so as to attach the bead wire 8 to a predetermined position on the side surface of the tire component.

[0079] The end effector 20 of this embodiment can deliver the bead wire 8 toward the tire component to install the bead wire 8 on the tire component. If the end effector 20 is used, the bead wire 8 can be installed at a desired position on the side of the tire component constituting the raw tire M in coordination with the operation of the robot 110.

[0080] In addition, in the end effector 20, the support portion 24 has a first support portion 24a and a second support portion 24b, and the second support portion 24b is connected to the first support portion 24a in a manner such that an extension axis O2 of the second support portion 24b intersects with an extension axis O1 of the first support portion 24a and the second support portion 24b is located on a side opposite to the joint portion 21 across the first support portion 24a.

[0081] exist Figure 7 , the end effector 20 is schematically shown from the discharge portion 23 side. Figure 7 When the end effector 20 is observed along the X-axis direction (a direction parallel to the tire center axis when the tire center axis is included in the horizontal plane), the extension axis O1 of the first support portion 24a is inclined at an angle α toward the joint portion 21 side relative to the extension axis O2 of the second support portion 24b, compared to the discharge portion 23 side.

[0082] In addition, in this embodiment, if Figure 7 As shown, when viewed from the side, the rotation center axis O3 of the driving rotating part 29 is an axis passing through the center of the peripheral groove of the sticking roller 23a (the deepest part of the groove bottom of the peripheral groove). That is, the sticking roller 23a is arranged parallel to the rotation center axis O3 of the driving rotating part 29, and the material passing position P of the sticking roller 23a exists on the rotation center axis O3 of the driving rotating part 29.

[0083] Furthermore, by controlling the operation of the robot 110 so that the sticking roller 23a sticks the bead wire 8 toward the other side surface (the object driving unit 141 side) of the tire component constituting the raw tire M, the bead wire 8 can also be stuck on the other side surface of the tire component. In this case, the sticking position can be quickly switched by simply rotating the second support portion 24b 180° relative to the first support portion 24a.

[0084] In this manner, the bead wires 8 can be attached to both sides of the tire component attached to the core AM.

[0085] (Bead formation)

[0086] In the present embodiment, the tire manufacturing apparatus 100 is used, and in the manufacturing stage of the green tire M, the bead wire 8 is attached to the tire component as follows to form the tire. Figure 1 The bead (also referred to as a bead ring or a bead core) 16 is shown. In the present embodiment, a specific example of a tire component to which the bead wire 8 is attached is the carcass ply 14.

[0087] In the first step, an unvulcanized liner 18 is attached to the outer surface of the core AM.

[0088] Next, the unvulcanized carcass ply 14 is wound so as to cover the unvulcanized inner liner 18 (see Figure 8 ).

[0089] Then, the bead wire 8 is spirally attached to a predetermined position of the carcass ply 14 (a position which will later become the bead portion 12 of the pneumatic tire 10 ) as follows.

[0090] The robot 110 is operated to arrange the bonding roller 23a supporting the bead wire 8 at a predetermined position of the carcass ply 14 and at a position opposite to the bonding start position of the bead wire 8. Figure 2 As shown, the bead wire 8 is attached to the starting position at a predetermined distance R from the rotation axis O141, which is the inner peripheral portion of the bead portion 12 of the pneumatic tire 10 (see Figure 1 ) is approximately the same position as the inner diameter (R×2) of the inner bead 16A. Figure 2 In the drawings, reference numeral 8s denotes the start end of the bead wire 8 where winding starts, and reference numeral 8e denotes the end end of the bead wire 8 where winding ends.

[0091] In addition, in the present disclosure, it is provided that a bead wire is adhered to the outer side surface of a tire constituent component that is supported from the inner side by a core and is composed of unvulcanized rubber. In the present embodiment, the tire constituent component is a carcass ply 14, and the outer side surface of the tire constituent component refers to the outer side surface in the tire axial direction of a main portion 14A of the carcass ply 14 that spans the bead portion 12 on one side and the bead portion 12 on the other side before the end portion 14B of the carcass ply 14 is folded back.

[0092] Next, the cylinder 23b is operated, as shown in FIG. Fig. 9 As shown in the schematic cross-sectional view, the bead wire 8 supported by the pasting roller 23a is pressed against the side of the carcass cord layer 14 with a specified pressing force (more than 3N and less than 100N), and the core AM is rotated by a specified angle (slightly less than 360°) to paste in such a way that the bead wire 8 of the first circle becomes a perfect circle.

[0093] Next, the rotation of the core AM is continued, starting from slightly in front of the starting position of the bead wire 8, the sticking roller 23a is moved gradually radially outward along the side of the carcass ply 14 while maintaining the parallel state of the cylinder 23b. Thereafter, the sticking roller 23a is moved radially outward of the first circle of bead wire 8 that is first stuck so that the second circle of bead wire 8 is adjacent to the first circle of bead wire 8, and the sticking of the bead wire 8 continues.

[0094] Therefore, if Figure 2 As shown in the conceptual diagram of , the bead wire 8 is adhered to the outer side of the carcass ply 14 in a spiral shape to form the first layer of the carcass ply side of the bead 16.

[0095] exist Fig. 9 In FIG. 1 , the tire bead wire 8 is pasted from the radial inner side (the lower side of the drawing) to the radial outer side (the upper side of the drawing). Fig. 9 , the bonding roller 23a is shown pressing the bead wire 8 of the first circle against the carcass ply 14. The end effector 20 is moved radially outward by the robot 110 in such a manner that the axis of the cylinder 23b is kept parallel to the rotation axis O141 of the core AM and the bonding roller 23a is moved along the outer side of the carcass ply 14.

[0096] In addition, for the first turn of the bead wire 8, since the sticking roller 23a is not moved in the radial direction, the bead wire 8 is stuck to the carcass ply 14 with a constant diameter, that is, a perfect circle. As a result, the innermost peripheral portion with suppressed inner diameter deviation can be formed. In addition, for the second turn and thereafter, the bead wire 8 is also stuck in a perfect circle.

[0097] The bead wire 8 of this embodiment formed in a spiral shape only needs to be formed into a perfect circle with a predetermined size at the first innermost circle, and the second circle and subsequent circles located radially outside the innermost circle may be, for example, a spiral shape with gradually increasing diameters.

[0098] Furthermore, if the pressing force of the bead wire 8 on the unvulcanized carcass ply 14 is less than 3N, the pressing force is insufficient, and there is a concern that the bead wire 8 cannot be attached to the unvulcanized rubber surface of the carcass ply 14. On the other hand, if the pressing force exceeds 100N, the pressing force is too high, and there is a concern that the bead wire 8 may unnecessarily sink into the unvulcanized rubber of the carcass ply 14.

[0099] In the tire manufacturing method of the present embodiment, the bead wire 8 can be pressed against and adhered to the unvulcanized rubber surface of the carcass ply 14 with a pressing force within a range of greater than 3N and less than 100N, so that the bead wire 8 can be adhered to the unvulcanized rubber surface of the carcass ply 14 in an appropriate state.

[0100] In addition, even if the position of the outer side surface of the unvulcanized rubber of the carcass ply 14 against which the bead wire 8 is pressed changes slightly, the bead wire 8 can be pressed against the carcass ply 14 with a substantially constant pressing force by extending and retracting the piston rod 23bL of the cylinder 23b (because the air in the cylinder can expand and contract).

[0101] After forming the first layer on the carcass ply 14 side of the bead 16, the second layer and subsequent layers formed by the bead wire 8 in a spiral shape are sequentially formed on the side of the first layer in the same manner as the first layer, so that a structure such as Figure 1 The bead 16 is shown to be in the shape of a parallelogram in cross section.

[0102] In addition, for the second layer, after the radial outermost side of the bead wire 8 of the first layer is pasted, the bead wire 8 can be formed into a spiral shape toward the radial inner side. When the bead wire 8 is pasted spirally from the outer peripheral side to the inner peripheral side, the innermost circumference is formed into a perfect circle like the first layer.

[0103] The cross-sectional shape of the bead 16 in the present embodiment is a parallelogram, but the cross-sectional shape of the bead 16 is not limited to a parallelogram, and may be a trapezoid, a polygon, or a straight line.

[0104] After the bead 16 with a predetermined cross-sectional shape is formed, an uncured bead filler 19 (see Figure 1 ), and then roll up the tire width direction end portion of the carcass ply 14.

[0105] Afterwards, the raw tire M can be formed by adhering the outer part of the bead portion 12 in the tire width direction and the unvulcanized outer rubber component 108 constituting the sidewall portion to the outer side surface of the unvulcanized carcass ply 14, and adhering an unvulcanized belt (omitted in the figure) and an unvulcanized tread rubber (omitted in the figure) to the outer peripheral surface of the unvulcanized carcass ply 14.

[0106] As described above, according to the present embodiment, the bead wire 8 fed from the wire supply unit 120 is pressed against the outer side surface of the tire component including unvulcanized rubber by the sticking roller 23a and the cylinder 23b as the pressing device in parallel with the rotation axis O141 of the core AM, and the bead wire 8 is pressed in the radial direction of the core AM while being kept parallel to each other and is adhered in a spiral shape, so that the bead 16 with suppressed inner diameter deviation can be formed on the tire component. In the case where the tire component is the carcass ply 14, the bead 16 can be formed on the outer surface side of the carcass ply 14. The core AM supporting the tire component is rotatable, so the bead wire 8 can be adhered in a spiral shape to the outer side surface of the tire component by moving the pressing device in the radial direction of the core AM by the robot 110 as the moving device while rotating the core AM supporting the tire component. Since the bead 16 having a constant inner diameter with suppressed inner diameter variation can be formed in this manner, in the pneumatic tire 10 obtained by vulcanization molding the green tire M, the bead portion 12 can be properly fitted to the rim (not shown).

[0107] (Comparative Example)

[0108] Below, according to Fig.10 The following will describe a method for manufacturing a tire according to a comparative example. In addition, the same reference numerals are given to the same structures as those in the above-described embodiment, and description thereof will be omitted.

[0109] The carcass ply 14 shown on the right side is, for example, coated with unvulcanized rubber thicker by α than the carcass ply 14 shown on the left side.

[0110] In this Fig.10 , the case where the carcass ply 14 is inclined by 40° with respect to the radial direction of the rotation axis O141 of the core AM is shown.

[0111] In the comparative example, the cylinder 23b is inclined so that its axis is at right angles to the outer surface of the carcass ply 14, and the distance from the rotation axis O141 is independent of the thickness of the carcass ply 14 and remains unchanged during the attachment of one turn of the bead wire 8.

[0112] The position of cylinder 23b remains unchanged and Fig.10 As shown, the thickness of the carcass ply 14 varies, for example, Fig.10When the carcass ply 14 is thicker as shown in the right figure, the position of the outer surface of the carcass ply 14 to which the bead wire 8 is attached changes, and accordingly, the piston rod 23bL supporting the attachment roller 23a is retracted toward the main body side of the cylinder 23b.

[0113] The cylinder 23b of the comparative example is inclined with respect to the radial direction of the rotation axis O141 of the core AM. Therefore, when the piston rod 23bL is retracted toward the main body of the cylinder 23b, the position of the sticking roller 23a supported by the piston rod 23bL is offset toward the rotation axis O141 side, and thus the position where the bead wire 8 is stuck is offset toward the rotation axis O141 side. Furthermore, when the thickness of the carcass ply 14 is reduced, the position where the bead wire 8 is stuck is offset toward the side opposite to the rotation axis O141 side.

[0114] In this way, if the position of pasting the bead wire 8 is radially offset according to the thickness of the carcass ply 14, the distance (R) of the bead wire 8 pasted on the outer surface of the carcass ply 14 from the rotation axis O141 will be different, resulting in a deviation in the inner diameter of the bead (R×2).

[0115] On the other hand, according to the tire manufacturing method of the present embodiment, even if the thickness of the carcass cord layer 14 changes, the piston rod 23bL is extended and retracted while remaining parallel to the rotation axis O141 of the core AM, and the radial position of the tire bead wire 8 pressed by the pasting roller 23a remains unchanged, so that a tire bead 16 of a specified inner diameter with suppressed inner diameter deviation can be obtained.

[0116] [Other embodiments]

[0117] As mentioned above, although one embodiment of the present disclosure has been described, the present disclosure is not limited to the above, and it is a matter of course that various modifications other than the above can be made and implemented without departing from the gist of the present disclosure.

[0118] In the above embodiment, the carcass ply 14 is cited as the tire constituent member to which the bead wire 8 is attached, but the tire constituent member to which the bead wire 8 is attached may also be a member other than the carcass ply 14 such as a bead portion reinforcement member (not shown) adjacent to the carcass ply 14.

[0119] In the above-described embodiment, the bead wire 8 is attached from the inner peripheral side toward the outer peripheral side to form a spiral shape, but the bead wire 8 may be attached from the outer peripheral side toward the inner peripheral side to form a spiral shape.

[0120] The disclosure of Japanese Patent Application No. 2022-198949 filed on December 13, 2022 is incorporated herein by reference in its entirety.

[0121] All documents, patent applications, and technical standards described in this specification are incorporated herein by reference to the same extent as if each individual document, patent application, or technical standard were specifically and separately described.

Claims

1. A method for manufacturing a tire, comprising attaching a bead wire to the outer side of a tire component including unvulcanized rubber and supported from the inner side by a core, wherein: In this manufacturing method, the bead wire is pressed against the outer surface in parallel with the rotation axis of the core, and the bead wire is moved in a radial direction of the core while being kept parallel to be adhered in a spiral shape, thereby forming a bead.

2. The method for manufacturing a tire according to claim 1, wherein: The pressing is performed by a sticking roller supported by a piston rod of an air cylinder provided parallel to the rotation axis.

3. The method for manufacturing a tire according to claim 1 or 2, wherein: The pressing force of pressing the bead wire against the outer surface is within a range of 3N to 100N.

4. The method for manufacturing a tire according to claim 1, wherein: The tire constituent member is a carcass ply in which a plurality of cords arranged parallel to each other are covered with unvulcanized rubber.

5. A tire manufacturing device, comprising: a core that is rotatable and that supports from the inside a tire component that is composed of unvulcanized rubber; a pressing device for pressing the bead wire fed from the wire supply portion against the outer side surface of the tire component in parallel with the rotation axis of the core; and A moving device moves the pressing device in the radial direction of the core while maintaining the above-mentioned parallel state.

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