Method and apparatus for manufacturing annular rubber member

Abstract

To provide a production method and an apparatus that can produce an annular rubber member formed by winding a rubber strip material around a drum body with high precision to target mass while suppressing variations in mass.SOLUTION: A production method and an apparatus for an annular rubber member comprises: presetting a target range AR for a transportation time CT that is required from extruding an unvulcanized rubber strip material S from an extruder 2 to passing through a dancer path 6 and winding the rubber strip material S around a drum body 9; controlling rotational speeds of transport driving rollers 5a, 5b, 5c, 5d to adjust a length L of the dancer path 6 by a control unit 10 depending on an extrusion speed V of the rubber strip material S; maintaining the transportation time CT within the target range AR; and winding the rubber strip material S around the drum body 9 to produce an annular rubber member Rc.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method and an apparatus for manufacturing an annular rubber member. More specifically, the present invention relates to a manufacturing method and an apparatus capable of manufacturing an annular rubber member formed by winding a rubber strip material around a drum body with suppressed mass variation and with high accuracy to a target mass.

Background Art

[0002] In the manufacturing process of rubber products such as tires, an unvulcanized rubber strip member extruded by an extruder may be used (see, for example, Patent Document 1). When this rubber strip material passes through an extrusion flow path (such as a die) at the front end of the extruder, it is shaped into a predetermined shape.

[0003] When unvulcanized rubber is released from the restraint of the die, it has the property of expanding in the width and thickness directions and contracting in the longitudinal direction (hereinafter referred to as swell). This swell occurs because the strain energy (residual stress) remaining in the shaped unvulcanized rubber tries to return the unvulcanized rubber to its state before being shaped. Due to this swell, the cross-sectional shape of the rubber strip material changes over time immediately after extrusion, and accordingly, the mass per unit length also changes.

[0004] In the dancer path where the rubber strip material moves in the air, the mass per unit length of the rubber strip material is particularly likely to vary due to this swell. And when the extrusion speed (transport speed) of the rubber strip material changes and the length of the dancer path remains unchanged, the time required to pass through the dancer path changes, so the variation in the weight per unit length of the rubber strip material due to residual stress becomes large. As a result, the mass of the annular rubber member manufactured by winding the rubber strip material around the drum body also varies. Therefore, there is room for improvement in manufacturing an annular rubber member with suppressed mass variation and with high accuracy to a target mass.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Japanese Patent Publication No. 2014-58064 [Overview of the project] [Problems that the invention aims to solve]

[0006] The object of the present invention is to provide a manufacturing method and apparatus that can manufacture an annular rubber member, formed by winding a rubber strip material around a drum body, with high precision and to a target mass while suppressing mass variations. [Means for solving the problem]

[0007] To achieve the above objective, the present invention provides a method for manufacturing an annular rubber member, in which an unvulcanized rubber strip material extruded from an extruder is conveyed through a dancer path and wound around a drum body to form an annular shape, wherein a target range for the conveying time required from the time the rubber strip material is extruded from the extruder until it is wound around the drum body is set in advance, and the length of the dancer path is controlled according to the extrusion speed of the rubber strip material, thereby maintaining the conveying time within the target range and winding the rubber strip material around the drum body. In the dancer path, three or more transport drive rollers for supporting and transporting the rubber strip material are arranged at intervals in the direction of separation between the extruder and the drum body, and when controlling the length of the dancer path, the rotational speed of the transport drive rollers is controlled based on the rotational speed of the transport drive rollers arranged adjacent to the extruder side. It is characterized by the following: Another method for manufacturing an annular rubber member of the present invention is a method for manufacturing an annular rubber member in which an unvulcanized rubber strip material extruded from an extruder is conveyed through a dancer path and wound around a drum body to form an annular shape, wherein a target range of conveyance time required from the time the rubber strip material is extruded from the extruder until it is wound around the drum body is set in advance, and the length of the dancer path is controlled according to the extrusion speed of the rubber strip material to maintain the conveyance time within the target range and wind the rubber strip material around the drum body, wherein a plurality of conveyance drive rollers for supporting and conveying the rubber strip material are arranged in the dancer path at intervals in the direction away from the extruder and the drum body, and the length of the dancer path is changed by controlling the rotation speed of the conveyance drive rollers according to the extrusion speed of the rubber strip material to maintain the conveyance time within the target range.

[0008] The present invention provides a manufacturing apparatus for an annular rubber member comprising: an extruder for extruding unvulcanized rubber strip material; a drum body around which the rubber strip material is wound to form an annular shape; a dancer path formed between the extruder and the drum body; a transport drive unit positioned in the dancer path for transporting the rubber strip material from the extruder through the dancer path to the drum body; and a control unit. In this apparatus, a target range for the transport time required from the extrusion of the rubber strip material from the extruder to winding it onto the drum body is set in advance, and the length of the dancer path is controlled by the control unit according to the extrusion speed of the rubber strip material, thereby maintaining the transport time within the target range and winding the rubber strip material onto the drum body. The transport drive unit comprises a plurality of transport drive rollers arranged in the dancer path at intervals in the direction of separation between the extruder and the drum body to support and transport the rubber strip material, and the control unit controls the rotational speed of the transport drive rollers according to the extrusion speed of the rubber strip material, thereby changing the length of the dancer path and maintaining the transport time within the target range. It is characterized by the following: [Effects of the Invention]

[0009] According to the present invention, by controlling the length of the dancer path according to the extrusion speed of the rubber strip material, the transport time required from the extrusion of the rubber strip material from the extruder to winding it onto the drum body is maintained within the target range, thereby suppressing variations in transport time regardless of the extrusion speed. As a result, variations in the degree of deformation of the rubber strip material during transport caused by swell immediately after extrusion are suppressed. Consequently, it is advantageous for manufacturing annular rubber members with a target mass with high precision while suppressing mass variations. [Brief explanation of the drawing]

[0010] [Figure 1] This is an explanatory diagram illustrating an embodiment of the manufacturing apparatus for an annular rubber member of the present invention in a side view. [Figure 2] Figure 1 is an explanatory diagram illustrating the manufacturing apparatus in a plan view. [Figure 3] This is an explanatory diagram illustrating a cross-sectional view of a manufactured annular rubber member. [Figure 4] This is an explanatory diagram illustrating a shortened version of the dancer path shown in Figure 1. [Figure 5]This graph illustrates the relationship between the extrusion speed of rubber strip material and the length of the dancer path. [Figure 6] This is an explanatory diagram illustrating another drum body in which an annular rubber member is formed, shown in a cross-sectional view of the left half. [Figure 7] Figure 6 is an explanatory diagram showing the drum body in a side view. [Modes for carrying out the invention]

[0011] The method and apparatus for manufacturing the annular rubber member of the present invention will be described below based on the embodiments shown in the figures.

[0012] In the embodiment of the manufacturing apparatus 1 for annular rubber members illustrated in Figures 1 and 2, an unvulcanized rubber strip material S extruded from an extruder 2 is wound around a drum body 9 to produce an annular rubber member Rc having a desired cross-sectional shape. This annular rubber member Rc is a concept that also includes cylindrical rubber members. The manufacturing apparatus 1 comprises an extruder 2 for extruding the rubber strip material S, a drum body 9, a dancer path 6 formed between the extruder 2 and the drum body 9, a transport drive unit 5 positioned in the dancer path 6, and a control unit 10.

[0013] In this embodiment, the manufacturing apparatus 1 further includes a position sensor 7 and a conveyor belt 8. The left-right direction in the drawing (the direction of separation between the extruder 2 and the drum body 9) is the front-rear direction in the manufacturing apparatus 1, and the left and right sides of the drawing are the front and rear of the manufacturing apparatus 1, respectively.

[0014] The extruder 2 comprises a cylindrical cylinder 2a, a screw 2b positioned inside the cylinder 2a, and a head 2c installed at the front end of the cylinder 2a. A die 3 is detachably attached to the front end of the head 2c. An extrusion channel 4 is formed in the die 3, communicating in the front-to-back direction. The extrusion channel 4 communicates with the inside of the cylinder 2a. Various known specifications of the extruder 2 can be used; for example, a specification with a gear pump attached to the head 2c may be used.

[0015] The unvulcanized rubber R introduced into the interior of the cylinder 2a is sent forward inside the cylinder 2a by a screw 2b that is rotationally driven by a drive motor while its viscosity is reduced (plasticized). As the unvulcanized rubber R passes through the extrusion channel 4, it is shaped and extruded as a rubber strip material S from the outlet of the extrusion channel 4 that opens to the front end face of the die 3.

[0016] The general shape of the cross-section of the rubber strip material S is determined by the cross-sectional shape of the extrusion channel 4. The cross-sectional shape of the rubber strip S is not particularly limited, and a desired shape such as a circular shape, an elliptical shape, a triangular shape, a square shape, or other polygonal shapes is adopted. The width dimension (diameter dimension) of the rubber strip material S is, for example, about 5 mm to 30 mm. Since the die 3 is detachable from the head 2c, a die 3 in which an extrusion channel 4 having a corresponding cross-sectional shape is formed is attached to the head 2c according to the cross-sectional shape of the rubber strip material S to be manufactured.

[0017] A conveying drive unit 5 and a conveying conveyor 8 are arranged in order between the extruder 2 and the drum body 9. The rubber strip material S shaped by the die 3 is passed from the extruder 2 through the dancer path 6 and conveyed to the drum body 9. In this embodiment, conveying drive rollers 5a, 5b, 5c, 5d that support and convey the rubber strip material S are adopted as the conveying drive unit 5. These conveying drive rollers 5a to 5d extend in a direction crossing the placed rubber strip material S. That is, the extending direction of the axial centers of the conveying drive rollers 5a to 5d and the extending direction of the rubber strip material S are orthogonal.

[0018] The rotational speeds of the respective conveying drive rollers 5a to 5d are controlled by the control unit 10. The number of the conveying drive rollers 5a to 5d is not limited to four and is appropriately determined to an appropriate number, for example, about 2 to 5, and 3 or more is preferable.

[0019] In this embodiment, the dancer path 6 is formed between the extruder 2 and the conveyor 8, and the conveying drive unit 5 is arranged in the dancer path 6. Each of the conveying drive rollers 5a, 5b, 5c, 5d and the conveyor 8 are arranged in sequence at intervals in the front-rear direction between the extruder 2 and the drum body 9.

[0020] The rubber strip material S is placed on the conveying drive rollers 5a, 5b, 5c, 5d and the conveyor 8, and the rubber strip material S is spanned between these adjacent ones and is in a state of hanging down by its own weight. This hanging-down portion of the rubber strip material S becomes the excess length of the rubber strip material S in the production line of the annular rubber member Rc.

[0021] The length L of the dancer path 6 is the length of the rubber strip material S existing in the dancer path 6. That is, the extending length of the rubber strip material S between the front end face of the die 3 and the rear end of the conveyor 8 is the length L of the dancer path 6.

[0022] By controlling the rotational speeds of the respective conveying drive rollers 5a to 5d, the length of the rubber strip material S existing in the dancer path 6 changes. That is, by controlling the movement of the conveying drive unit 5 by the control unit 10, the length L of the dancer path 6 can be changed to a desired length.

[0023] Position sensors 7 are arranged at upper positions between adjacent ones of the conveying drive rollers 5a, 5b, 5c, 5d and the conveyor 8. Each position sensor 7 detects the separation distance (vertical separation distance) from its installation position to the rubber strip material S existing below. Detection data from each position sensor 7 is input to the control unit 10.

[0024] As the position sensor 7, a sensor that can detect the separation distance to the rubber strip material S without contact with the rubber strip material S is preferable. For example, various known laser distance sensors, optical distance sensors, etc. can be used as the position sensor 7.

[0025] Since the installation positions of each position sensor 7 and each transport drive roller 5a to 5d are known, data on these installation positions is input to the control unit 10. Each position sensor 7 detects the distance to the rubber strip material S located below, and based on this detected data, the control unit 10 calculates the amounts h1, h2, h3, and h4 of the rubber strip material S hanging down from each transport drive roller 5a to 5d.

[0026] Furthermore, since the outer diameters of each of the transport drive rollers 5a to 5d, the outer diameter of the pulley of the transport conveyor 8, and the installation position of the transport conveyor 8 are also known, this data on the outer diameters and the installation position of the transport conveyor 8 are also input to the control unit 10. Therefore, based on this data input to the control unit 10 and the calculated sag amounts h1, h2, h3, and h4, the length L of the dancer path 6 is sequentially calculated by the control unit 10.

[0027] The conveyor belt 8 transports the placed rubber strip material S forward. Various known types of conveyor belts can be used for the conveyor belt 8, such as those equipped with rubber or resin conveyor belts.

[0028] The drum body 9 is formed in an annular shape by winding a rubber strip material S around it. In this embodiment, the rubber strip material S is wound around the outer circumferential surface of the cylindrical drum body 9 using a compression roller or the like. The rubber strip material S may also be wound around the outer circumferential surface of another member that is already wound around the outer circumferential surface of the drum body 9. Therefore, the rubber strip material S is wound directly or indirectly around the outer circumferential surface of the drum body 9. The drum body 9 is not limited to a cylindrical molding drum commonly used for forming green tires, but may also be a rigid core having an outer circumferential surface with the same profile as the inner circumferential surface of a finished vulcanized tire.

[0029] A sliding mechanism 9a is connected to the drum body 9. In this embodiment, an actuator such as a hydraulic cylinder is used as the sliding mechanism 9a. As the cylinder rod of the sliding mechanism 9a moves forward and backward, the drum body 9 slides in the drum width direction. The sliding mechanism 9a slides the rotating drum body 9. In this drum body 9, a rubber strip material S is wound spirally to produce an annular rubber member Rc.

[0030] The conveyor belt 8 may be slid without sliding the drum body 9 in the drum width direction, or both the drum body 9 and the conveyor belt 8 may be slid. If the conveyor belt 8 is slid, for example, the rotary drive rollers 5a to 5d, the extruder 2, and the position sensor 7 may be slid in synchronization with the conveyor belt 8.

[0031] A computer is used as the control unit 10. The control unit 10 controls the movement of the transport drive unit 5 and the transport conveyor 8. Furthermore, the control unit 10 can also be configured to control the movement of the drum 9, and even the movement of the extruder 2. The movements of the drum 9 and the extruder 2 can also be controlled by a separate control unit from the control unit 10.

[0032] The control unit 10 receives the various data mentioned above and other necessary data, and uses this data to perform calculations. The control unit 10 also receives data on the extrusion speed V. This extrusion speed V is directly or indirectly detected from the flow velocity of the unvulcanized rubber R passing through the head 2c and die 3, and can be detected using data such as the head pressure, the rotation speed of the screw 2b, or, in the case of an extruder 2 equipped with a gear pump, the rotation speed of the gear pump.

[0033] Next, an example of the procedure for manufacturing the annular rubber member according to the present invention will be described.

[0034] As illustrated in Figures 1 and 2, unvulcanized rubber R is extruded from a die 3 attached to the front end of the extruder 2 to form a rubber strip material S. This rubber strip material S is then stretched between the respective transport drive rollers 5a to 5d and the transport conveyor 8. This creates a dancer path 6 between the extruder 2 and the transport conveyor 8.

[0035] The rubber strip material S is pulled forward by the respective transport drive rollers 5a to 5d and the transport conveyor 8, and is transported from the extruder 2 through the dancer path 6 to the drum body 9. In Figure 1, the amounts of sagging h1, h2, h3, and h4 of the rubber strip material S from the respective transport drive rollers 5a to 5d are relatively large, and the length L of the dancer path 6 is maintained at a large state.

[0036] The drum body 9 rotates while being slid in the drum width direction by the sliding mechanism 9a. The rubber strip material S, transported by the conveyor 8, is pressed toward the outer surface of the drum body 9 by a compression roller or the like and positioned toward the outer surface of the drum body 9. As a result, the rubber strip material S is wound spirally around the drum body 9 while shifting its position in the drum width direction. The transport speed of the rubber strip material S by the conveyor 8 and the circumferential speed of the outer surface of the drum body 9 are controlled to be substantially the same without causing a significant difference between them.

[0037] Rubber strip materials S, wrapped adjacent to each other in the drum width direction, become joined together by their own adhesive properties. The drum body 9 not only slides in one direction in the drum width direction, but may also slide back and forth in the drum width direction as needed to wrap the rubber strip materials S around it.

[0038] When the rubber strip material S is cut to the required length and wound around the drum body 9, an annular (cylindrical) rubber member Rc is formed on the outer surface of the drum body 9, as illustrated in Figure 3. Such annular rubber member Rc becomes, for example, a component that forms the tire tread. The outer surface of the drum body 9 illustrated in Figure 3 has the same profile as the inner surface of the finished tire, and a rigid core is used as the drum body 9.

[0039] If the conveying speed of the rubber strip material S from the extruder 2 to the drum body 9 is kept slower than the extrusion speed V, the excess length of the rubber strip material S will increase indefinitely, making the production line unsustainable. If it is kept faster than the extrusion speed V, the excess length of the rubber strip material S will become negative, causing the rubber strip material S to break. Therefore, the conveying speed of the rubber strip material S from the extruder 2 to the drum body 9 is set to be substantially the same as the extrusion speed V in a steady state.

[0040] The extruder 2 basically continues to extrude unvulcanized rubber R at an extrusion speed V within a constant tolerance range in order to obtain rubber strip material S of consistent quality, but the extrusion speed V may be changed during the process. Also, since the appropriate extrusion speed V differs depending on the specifications (rubber type) of the unvulcanized rubber R, the extrusion speed V is set differently according to the specifications of the unvulcanized rubber R.

[0041] If the length L of the dancer path 6 remains constant when the extrusion speed V of the rubber strip material S changes, the time required for the rubber strip material S to pass through the dancer path 6 changes. That is, if the length L of the dancer path 6 remains constant, increasing the extrusion speed V will shorten the time required for the rubber strip material S to pass through the dancer path 6, and decreasing the extrusion speed V will lengthen the time required for the rubber strip material S to pass through the dancer path 6.

[0042] The rubber strip material S is molded by the die 3, but immediately after being released from the constraint of the die 3, a change in shape occurs over time due to swell. If the extruded rubber strip material S is not constrained in any way, the effect of swell is greatest immediately after being extruded from the die 3, so it expands greatly in the width and thickness directions and contracts greatly in the longitudinal direction. Then, as time passes after being extruded from the die 3, the effect of swell decreases, and the degree of change in the shape of the rubber strip material S over time decreases.

[0043] Therefore, as the rubber strip material S moves from the extruder 2 to the drum body 9, it is affected by swell (in other words, residual stress), causing the mass per unit length to fluctuate. In the dancer path 6, where the rubber strip material S moves through the air, the mass per unit length of the rubber strip material S is particularly prone to fluctuation due to this swell.

[0044] The less variation there is in the transport time CT required from the extrusion of the rubber strip material S from the extruder 2 until it is wound onto the drum body 9, the more advantageous it is for suppressing fluctuations in the mass per unit length of the rubber strip material S caused by swell. Therefore, in this invention, a target range AR for the transport time CT is set in advance, and this target range AR data is also input to the control unit 10. Then, the length L of the dancer path 6 is controlled by the control unit 10 according to the extrusion speed V to maintain the transport time CT within the target range AR.

[0045] In detail, when increasing the extrusion speed V, the rotational speed of each transport drive roller 5a to 5d is temporarily reduced to increase the length of the rubber strip material S in the dancer path 6. At this time, the transport speed of the transport conveyor 8 is also reduced. By controlling the movement of the transport drive unit 5 by the control unit 10 in this way, the amount of sagging h1, h2, h3, and h4 of the rubber strip material S from each transport drive roller 5a to 5d is increased, thereby increasing the length L2 of the dancer path 6 to the desired length and maintaining that desired length. The movement of the transport drive unit 5 is controlled while understanding the amount of sagging h1, h2, h3, and h4 based on the detection data from each position sensor 7. This prevents the transport time CT from shortening even when the extrusion speed V is increased, and maintains it within the target range AR.

[0046] In Figure 1, the amounts of sagging h1, h2, h3, and h4 of the rubber strip material S from each of the transport drive rollers 5a to 5d are equal. If the length L of the dancer path 6 can be increased to the desired length, the respective amounts of sagging h1, h2, h3, and h4 can be set arbitrarily. Therefore, it is possible to make at least one of the respective amounts of sagging h1, h2, h3, and h4 different.

[0047] When the extrusion speed V is reduced, the rotation speed of each transport drive roller 5a to 5d is temporarily increased to reduce the length of the rubber strip material S in the dancer path 6, as illustrated in Figure 4. At this time, the transport speed of the transport conveyor 8 is also increased. By controlling the movement of the transport drive unit 5 by the control unit 10 in this way, the amount of sagging h1, h2, h3, and h4 of the rubber strip material S from each transport drive roller 5a to 5d is reduced, thereby reducing the length L of the dancer path 6 to the desired length and maintaining it at that desired length. The movement of the transport drive unit 5 is controlled while understanding the amount of sagging h1, h2, h3, and h4 based on the detection data from each position sensor 7. This prevents the transport time CT from becoming longer even when the extrusion speed V is reduced, and maintains it within the target range AR.

[0048] When controlling the length L of the dancer path 6, for example, the rotational speed of each conveying drive roller 5b to 5d is controlled based on the rotational speed of the conveying drive rollers 5a to 5c that are located adjacent to each other on the extruder 2 side. That is, the rotational speed of each of the conveying drive rollers 5b, 5c, and 5d is controlled based on the rotational speed of the conveying drive rollers 5a, 5b, and 5c. The conveying speed of the conveying conveyor 8 is controlled based on the rotational speed of the adjacent conveying drive roller 5d.

[0049] By controlling the rotation speeds of the other transport drive rollers 5b to 5d and the transport speed of the transport conveyor 8 based on the rotation speed of the transport drive roller 5a, which is located closest to the extruder 2, the length L of the dancer path 6 can be smoothly changed to the desired length. In other words, when changing the length L of the dancer path 6 to the desired length, it is possible to avoid complicating the control of the transport drive unit 5 and the transport conveyor 8.

[0050] In Figure 4, the amounts of sagging h2 and h3 of the rubber strip material S from the transport drive rollers 5b and 5c are smaller than the amounts of sagging h1 and h4 from the transport drive rollers 5a and 5d. If the length L of the dancer path 6 can be reduced to the desired length, the respective amounts of sagging h1, h2, h3, and h4 can be set arbitrarily. Therefore, it is also possible to make the respective amounts of sagging h1, h2, h3, and h4 equal.

[0051] For example, as shown in Figure 5, the length L of the dancer path 6 is increased in accordance with the increase in the extrusion speed V, thereby maintaining the transport time CT within the target range AR regardless of the extrusion speed V. By controlling the length L of the dancer path 6 in accordance with the extrusion speed V in this way and maintaining the transport time CT within the target range AR, variations in the deformation of the rubber strip material S during transport caused by swell immediately after extrusion are suppressed. Consequently, it is advantageous to manufacture annular rubber members Rc with a target mass with high precision while suppressing mass variations.

[0052] In other words, by changing the length L of the dancer path 6, the time it takes for the residual stress in the rubber strip material S to be relieved between the extruder 2 and the drum body 9 can be made uniform, even if the extrusion speed V changes. As a result, variations in the magnitude of residual stress can be corrected, which suppresses variations in the shape (cross-sectional shape) of the rubber strip material S caused by swell, and makes it easier to stabilize the mass per unit length of the rubber strip material S. In this embodiment, since the length L of the dancer path 6 can be changed steplessly, variations in the magnitude of residual stress (in other words, variations in mass) can be corrected with even greater reduction.

[0053] Using rubber strip material S with suppressed mass variation in this way is advantageous for forming annular rubber member Rc, which is manufactured by winding the rubber strip material S in a spiral shape, into the desired shape with higher precision. As a result, it contributes to improving the uniformity of tires manufactured using this annular rubber member Rc.

[0054] In this production line for the annular rubber member Rc, the excess length of the rubber strip material S is absorbed in the dancer path 6. Therefore, even during intervals such as when the rotation of the drum body 9 is temporarily stopped to remove the manufactured annular rubber member Rc from the drum body 9 or when the drum body 9 is replaced, the extruder 2 can continue to extrude the rubber strip material S.

[0055] The degree of swell varies depending on the specifications of the unvulcanized rubber R. Therefore, it is advisable to pre-determine the appropriate range of the length L of the dancer path 6, which changes according to the extrusion speed V, for each specification of the unvulcanized rubber R, and store this as pre-data in the control unit 10. When manufacturing annular rubber members Rc, specific data identifying the specifications of the unvulcanized rubber R is input to the control unit 10. Based on this specific data and the pre-determined pre-data, the control unit 10 changes the length L of the dancer path 6 to the appropriate range according to the extrusion speed V. This allows for more reliable control of the length L of the dancer path 6 to the appropriate range even when manufacturing annular rubber members Rc using unvulcanized rubber R of various specifications, which is beneficial for maintaining the transport time CT within the target range AR.

[0056] In this embodiment, the manufacturing apparatus 1 has a conveyor belt 8, but the conveyor belt 8 is not an essential component, and instead of the conveyor belt 8, for example, a drive roller can be used. The position sensor 7 is also not an essential component, and other means can be used to detect the amount of sagging h1, h2, h3, h4 of the rubber strip material S from each of the drive rollers 5a to 5d.

[0057] In the drum body (rigid core) 9 illustrated in Figures 6 and 7, for example, a rubber strip material S is spirally wound around both ends in the width direction of the outer circumferential surface of the rotating drum body 9 to produce an annular rubber member Rc. The rubber strip material S may be wound directly around the outer circumferential surface of the drum body 9, or it may be wound around the outer circumferential surface of another member (inner liner and carcass layer) that is already wound around the outer circumferential surface of the drum body 9. The rubber strip material S is wound spirally along the outer circumferential surface of the drum body 9. In this embodiment, the produced annular rubber member Rc becomes a member that forms the tire sidewall. A cylindrical rubber member Rc can also be produced by spirally winding the rubber strip material S around the center in the width direction of the rotating drum body 9. [Explanation of Symbols]

[0058] 1 Manufacturing equipment 2 Extruder 2a Cylinder 2b Screw 2c head 3 Dies 4 Extrusion channel 5. Transport drive unit 5a, 5b, 5c, 5d Conveyor drive rollers 6 Dancer Path 7. Position Sensor 8. Conveyor 9 drum bodies 10 Control Unit S Rubber strip material Rc annular rubber member (tubular rubber member, annular rubber member, cylindrical rubber member) R Unvulcanized rubber

Claims

1. In a method for manufacturing an annular rubber member, in which an unvulcanized rubber strip material extruded from an extruder is conveyed through a dancer path and wound around a drum body to form an annular shape, A target range for the transport time required from the extrusion of the rubber strip material from the extruder to winding it onto the drum body is set in advance, and the length of the dancer path is controlled according to the extrusion speed of the rubber strip material to maintain the transport time within the target range and wind the rubber strip material onto the drum body. A method for manufacturing an annular rubber member, wherein three or more conveying drive rollers for supporting and conveying the rubber strip material are arranged in the dancer path at intervals in the direction of separation between the extruder and the drum body, and when controlling the length of the dancer path, the rotational speed of the conveying drive rollers is controlled based on the rotational speed of the conveying drive rollers arranged adjacent to the extruder side.

2. In a method for manufacturing an annular rubber member, in which an unvulcanized rubber strip material extruded from an extruder is conveyed through a dancer path and wound around a drum body to form an annular shape, A target range for the transport time required from the extrusion of the rubber strip material from the extruder to winding it onto the drum body is set in advance, and the length of the dancer path is controlled according to the extrusion speed of the rubber strip material to maintain the transport time within the target range and wind the rubber strip material onto the drum body. A method for manufacturing an annular rubber member, wherein a plurality of conveying drive rollers for supporting and conveying the rubber strip material are arranged in the dancer path at intervals in the direction of separation between the extruder and the drum body, and the length of the dancer path is changed by controlling the rotational speed of the conveying drive rollers according to the extrusion speed of the rubber strip material, thereby maintaining the conveying time within the target range.

3. The method for manufacturing an annular rubber member according to claim 1 or 2, wherein the drum body is a rigid core having an outer surface with the same profile as the inner surface of a completed vulcanized tire.

4. An apparatus for manufacturing an annular rubber member comprises an extruder for extruding unvulcanized rubber strip material, a drum body around which the rubber strip material is wound to form an annular shape, a dancer path formed between the extruder and the drum body, a transport drive unit positioned in the dancer path for transporting the rubber strip material from the extruder through the dancer path to the drum body, and a control unit, A target range for the transport time required from the extrusion of the rubber strip material from the extruder to winding it onto the drum body is set in advance, and the length of the dancer path is controlled by the control unit according to the extrusion speed of the rubber strip material, thereby maintaining the transport time within the target range and winding the rubber strip material onto the drum body. The transport drive unit consists of a plurality of transport drive rollers arranged in the dancer path at intervals in the direction of separation between the extruder and the drum body, which support and transport the rubber strip material. A manufacturing apparatus for annular rubber members, wherein the rotational speed of the conveying drive roller is controlled by the control unit in accordance with the extrusion speed of the rubber strip material, thereby changing the length of the dancer path, and maintaining the conveying time within the target range.

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