Tire manufacturing method and manufacturing system

Abstract

To provide a tire manufacturing method and a tire manufacturing system capable of suppressing variation in tire weight caused by shrinkage of tire members over time in a tire manufacturing process.SOLUTION: A tire manufacturing method includes: reading with a first reader 4a an identification mark 3 attached by a mark-attaching machine 2 for each range S corresponding to an individual size of one tire of a long body L; storing an initial separation distance D1 between identification marks 3 attached to the adjacent ranges S measured by a first measuring machine 6a, and tied to the corresponding identification mark 3 in a calculation section 7; measuring with a second measuring machine 6b a separation distance D2 in use between the identification marks 3 attached to the adjacent range S read by a second reader 4 in a process of feeding the long body L to a drum body 15a; and cutting the long body L wound on the drum body 15a into individual sizes by a cutting machine 14b, based on a difference D between the distance D1 and the distance D2, by operating a length adjustment by a length adjustment mechanism 8 for a range corresponding to the separation distance D2 in use corresponding to the difference D.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a tire manufacturing method and manufacturing system, and more particularly to a tire manufacturing method and manufacturing system that can suppress variations in tire weight caused by shrinkage of tire components over time during the tire manufacturing process. [Background technology]

[0002] Tires are manufactured using various tire components, such as unvulcanized rubber extruded by an extruder or the like, and a reinforcing layer formed of unvulcanized rubber and reinforcing cords. When manufacturing a tire, these various tire components are integrated in a molding process to form a green tire. The green tire is then vulcanized to manufacture the tire.

[0003] Some tire components containing unvulcanized rubber shrink significantly over time, and this shrinkage increases the thickness (cross-sectional area) of the tire components. Therefore, even if a tire component is initially cut to a fixed length equivalent to the length of one tire, by the time it is wound around a building drum to form a green tire, the tire may shrink over time to a length that does not meet the standard value. Therefore, various methods have been proposed for stretching the cut tire component and winding it around a building drum so that it meets the standard value (see, for example, Patent Documents 1 and 2).

[0004] Instead of using tire components cut to a fixed length in advance, one method for building a green tire involves winding a long body, which will become the raw tire components, around a building drum and then cutting it to a length equivalent to one tire. This method eliminates the need for stretching the tire components, as described above, and is advantageous for improving the uniformity of manufactured tires. However, if the long body shrinks significantly over time, the weight of the tire components wound around the building drum at a length equivalent to one tire becomes excessively large. In other words, when green tires are built using this method, variations in the degree of shrinkage of the long body over time can cause variations in the weight of the green tires, which ultimately leads to variations in the weight of manufactured tires. Therefore, there is room for improvement in suppressing variations in tire weight caused by the shrinkage of tire components over time during the tire manufacturing process and accurately achieving the target weight. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-136317 [Patent Document 2] Japanese Patent Application Publication No. 5-245952 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a tire manufacturing method and manufacturing system that can suppress variations in tire weight caused by the shrinkage of tire components over time during the tire manufacturing process. [Means for solving the problem]

[0007] In order to achieve the above object, the present invention provides a tire manufacturing method that includes integrating a plurality of types of tire components, including tire components obtained by cutting a long body wound on a drum body into individual tire sizes, to form a green tire, and vulcanizing the green tire, and the tire is manufactured by vulcanizing the green tire. In the tire manufacturing method, when the long body is manufactured, an identification mark is attached to each area of ​​the long body corresponding to the individual tire size, and each of the identification marks is read and a distance between the identification marks attached to areas corresponding to adjacent individual sizes in the longitudinal direction of the long body is measured, and each of the measured distances is associated with the corresponding identification mark as an initial distance and stored in a calculation unit, and when the green tire is manufactured, the long body is driven by a drum body. During the process of supplying the long body to the ram body, each of the identification marks is read, and the distance between the identification marks attached in the range corresponding to the individual size adjacent to each other in the longitudinal direction of the long body is measured, and this distance is input to the calculation unit as the in-use distance.The calculation unit calculates the difference between each of the initial distances and the corresponding in-use distances, and during the process of supplying the long body to the drum body, based on the magnitude of each calculated difference, a length adjustment operation is performed to bring the weight per unit length into a target range for the range corresponding to each in-use distance corresponding to each difference, and the long body is wound around the drum body, and the long body wound on the drum body is cut into individual sizes equivalent to one tire.

[0008] The tire manufacturing system of the present invention includes component manufacturing equipment for manufacturing each of a plurality of types of tire components, molding equipment for integrating the plurality of types of tire components to form a green tire, and vulcanization equipment for vulcanizing the green tire, and each of the component manufacturing equipment includes a long body manufacturing machine for manufacturing long bodies, and a cutting machine for cutting the long body wound around a drum body into the tire components of individual sizes for one tire. The tire manufacturing system further includes a marking machine that, when the long body is manufactured, attaches an identification mark to each area of ​​the long body corresponding to the individual size of one tire, a first reader that reads each of the identification marks, a first measuring machine that measures, as an initial separation distance, the separation distance between the identification marks attached to the area corresponding to the individual size adjacent in the longitudinal direction of the long body, and a calculation unit that associates and stores each of the initial separation distances with the corresponding identification mark, and a cutting machine that cuts the long body onto the drum body when the green tire is formed. a second measuring machine that measures, as an in-use separation distance, a separation distance between the identification marks affixed to adjacent areas in the longitudinal direction of the long body; a length adjustment mechanism that performs a length adjustment operation on the long body while the long body is being supplied to the drum body; and a control unit that controls the length adjustment mechanism, wherein the calculation unit calculates a difference between each of the initial separation distances and the corresponding in-use separation distances, and during the process of supplying the long body to the drum body, the control unit controls the length adjustment mechanism based on the magnitude of each difference so that the weight per unit length falls within a target range for the range corresponding to the in-use separation distance corresponding to each of the differences, whereby the long body is wound on the drum body, and the long body wound on the drum body is cut into the individual sizes by the cutting machine. [Effects of the Invention]

[0009] According to the present invention, by calculating the difference between each of the initial separation distances and the corresponding in-use separation distances, it is possible to grasp the amount of shrinkage over time within the range corresponding to each of the in-use separation distances from the production of the long body to the formation of a green tire. Then, in the process of supplying the long body to the drum body, the length adjustment mechanism is used to perform a length adjustment operation so that the weight per unit length falls within a target range for the range corresponding to each of the in-use separation distances corresponding to each of the differences based on the magnitude of each of the calculated differences. In this way, by cutting the long body wound on the drum body into individual lengths equivalent to one tire, it is possible to suppress variations in tire weight that occur due to shrinkage over time of the tire components formed by cutting the long body during the tire manufacturing process. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is an explanatory diagram illustrating a tire manufacturing system of the present invention. [Figure 2] FIG. 2 is an explanatory diagram illustrating an enlarged example of a part of the manufacturing system of FIG. [Figure 3] 3 is an explanatory diagram illustrating the manufacturing system of FIG. 2 in plan view. [Figure 4] 1. FIG. 4 is an explanatory diagram illustrating the movement of the length adjusting mechanism of FIG. 1 as seen from the side. [Figure 5] 10 is an explanatory side view illustrating another embodiment of the length adjustment mechanism. FIG. [Figure 6] 10 is an explanatory side view illustrating yet another embodiment of the length adjustment mechanism. FIG. [Figure 7] 10 is an explanatory side view illustrating yet another embodiment of the length adjustment mechanism. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A tire manufacturing method and manufacturing system according to the present invention will be described below based on the embodiments shown in the drawings.

[0012] In the embodiment of the tire manufacturing system 1 of the present invention illustrated in Figures 1 to 4, a green tire G is formed by integrating multiple types of tire components E (E1, E2, E3, E4, ...). The green tire G is vulcanized to manufacture a tire T.

[0013] This embodiment of the manufacturing system 1 includes component manufacturing equipment (e.g., kneader 11, extruder 12) for manufacturing each of multiple types of tire components E, molding equipment (e.g., molding machine 15) for integrating the tire components E to form a green tire G, and vulcanization equipment (e.g., vulcanizer 16) for vulcanizing the green tire G. Various known types of component manufacturing equipment, molding equipment, and vulcanization equipment can be used. The manufacturing system 1 further includes a marking machine 2, a first reader 4a, a second reader 4b, a first measuring machine 6a, a second measuring machine 6b, a calculation unit 7, a length adjustment mechanism 8, a control unit 10, a stocking means 14a, a cutting machine 14b, and a weighing scale 5. The manufacturing system 1 also includes a profile sensor 5a, but the profile sensor 5a can be optionally included.

[0014] The multiple types of tire components E include tire components E1 formed into individual lengths corresponding to one tire by cutting a long body L wound around a drum body 15a constituting the molding machine 15. The long body L is, for example, a component manufactured by extruding unvulcanized rubber R or a component manufactured by rolling it.

[0015] When the long body L is made only of unvulcanized rubber R, examples of the tire component E1 include tread rubber, side rubber, and inner liner. When the long body L is made by combining unvulcanized rubber R and reinforcing cords, examples of the tire component E1 include carcass material and belt material. Even among the various components described above, components that are cut to a predetermined length before being wound around the drum body 15a and bead rings are not the tire component E1 but are other tire components E2, E3, E4, ...

[0016] The manufacturing equipment for the tire component E1 includes a long body manufacturing machine 12 that manufactures the long body L, and a cutting machine 14b that manufactures the tire component E1 by cutting the long body L wound around a drum body 15a. In this embodiment, a rubber extrudate manufactured by extruding unvulcanized rubber R is used as an example of the tire component E1, so the manufacturing equipment for the tire component E1 includes a kneader 11 that supplies kneaded unvulcanized rubber R to the long body manufacturing machine 12, and the long body manufacturing machine 12 is an extruder 12 for unvulcanized rubber. If the tire component E1 is a rolled material manufactured by rolling unvulcanized rubber R, the long body manufacturing machine 12 is a rolling device.

[0017] After being manufactured by the elongated body manufacturing machine 12, the elongated body L is stocked in the stock means 14a. Thereafter, when a tire component E1 is needed to mold a green tire G, the elongated body L is supplied from the stock means 14a to the molding machine 15. A conveying mechanism 13 is disposed between the elongated body manufacturing machine 12 and the stock means 14a, and between the stock means 14a and the molding machine 15.

[0018] The molding facility includes a molding machine 15 having a drum body 15a. The drum body 15a is not limited to a general molding drum, and may be a rigid core having an outer surface with the same shape as the inner surface of the tire T to be manufactured. The molding facility is appropriately equipped with a supply mechanism (such as a conveying mechanism 13) that supplies each tire component E to the molding machine 15, and other necessary equipment.

[0019] The vulcanization facility includes a vulcanization device 16 to which a vulcanization mold 17 is attached. The vulcanization facility is appropriately equipped with a feeding mechanism for feeding a green tire G into the vulcanization mold 17, a removal mechanism for removing the manufactured tire T from the vulcanization mold 17, and other necessary equipment.

[0020] When the elongated body L is manufactured, the marking machine 2 marks an identification mark 3 for each range S of the elongated body L, which corresponds to the individual size of one tire (i.e., the length of one tire component E1). For example, the marking machine 2 may be a device that marks the identification mark 3 by applying ink or the like to the surface of the elongated body L by spraying, transferring, or the like. The control unit 10 that controls the marking machine 2 receives input of the conveying speed of the elongated body L by the conveying mechanism 13, so that the marking machine 2 can be used to mark the identification mark 3 for each range S of the elongated body L being conveyed. In this embodiment, one identification mark 3 is marked for each range S of the elongated body L, which corresponds to the individual size of one tire, but the same identification mark 3 may be marked at intervals within one range S.

[0021] The identification mark 3 is not particularly limited in its specifications as long as it can be read by the first reader 4a and the second reader 4b and the position where the identification mark 3 is attached can be identified. Various letters, numbers, symbols, two-dimensional codes, or combinations of these can be used as the identification mark 3, and it is preferable to include, for example, a serial number indicating the order in which the identification marks 3 are attached.

[0022] To improve reading accuracy, it is preferable that the identification mark 3 be a color that stands out against the color of the tire component E1 to which the identification mark 3 is attached. Since most tire components E1 are black, the identification mark 3 should be a whitish color, yellowish color, or other color that is reasonably easy to see against black.

[0023] The first reader 4a and the second reader 4b may have the same specifications, and for example, various known types that can read the identification mark 3 without contacting the long body L being transported can be used. In detail, the first reader 4a is disposed downstream of the marking machine 2, between the long body manufacturing machine 12 and the stock means 14a. The second reader 4b is disposed between the stock means 14a and the molding machine 15. Specifically, known scanners equipped with a digital camera or the like that acquire image data can be used as the first reader 4a and the second reader 4b.

[0024] The first measuring machine 6a and the second measuring machine 6b measure the length of the target portion of the elongated body L. The first measuring machine 6a and the second measuring machine 6b may have the same specifications, and for example, any of various known types that can measure the length of the target portion of the elongated body L without contacting the elongated body L being transported can be used.

[0025] More specifically, the first measuring device 6a is disposed between the elongate body manufacturing machine 12 and the storage means 14a, and is disposed downstream of the first reader 4a. As the elongate body L is transported from the elongate body manufacturing machine 12 to the storage means 14a by the transport mechanism 13, the separation distance between the identification marks 3 affixed to adjacent ranges S in the longitudinal direction of the elongate body L is measured as the initial separation distance D1. Because the transport speed of the transport mechanism 13 is known, the initial separation distance D1 between these identification marks 3 can be measured based on the time from when the first measuring device 6a detects the identification mark 3 affixed to one range S to when it detects the identification mark 3 affixed to the adjacent range S, and the transport speed of the transport mechanism 13. Each measured initial separation distance D1 is input to the calculation unit 7.

[0026] The second measuring machine 6b is disposed downstream of the second reader 4b, between the stock means 14a and the molding machine 15. The second measuring machine 6b measures the distance between the identification marks 3 affixed to adjacent ranges S in the longitudinal direction of the long body L as the in-use separation distance D2 while the long body L is being transported from the stock means 14a to the molding machine 15 by the transport mechanism 13. The in-use separation distance D2 between these identification marks 3 can be measured based on the time from when the second measuring machine 6b detects the identification mark 3 affixed to one range S to when it detects the identification mark 3 affixed to the adjacent range S, and the transport speed of the transport mechanism 13. Each measured in-use separation distance D2 is input to the calculation unit 7.

[0027] The first reader 4a and the second reader 4b can also function as the first measuring device 6a and the second measuring device 6b, respectively. In this case, the first reader 4a and the second reader 4b also function as the first measuring device 6a and the second measuring device 6b, respectively, so that the number of measuring devices can be reduced.

[0028] The weighing scale 5 measures the weight of the long object L within a predetermined range, and the measured weight is input to the calculation unit 7. In this embodiment, the weight is measured within a range corresponding to the initial separation distance D1 of each long object L. As the weighing scale 5, a known weighing scale that is installed on the underside of the conveying mechanism 13 and can continuously measure the mass of the long object L being conveyed and moved can be used.

[0029] The profile sensor 5a measures the cross-sectional shape of the long body L at a desired set position, and the measured cross-sectional shape is input to the calculation unit 7. In this embodiment, the cross-sectional shape of at least one position within the range corresponding to the initial separation distance D1 of each long body L is measured. As the profile sensor 5a, a known sensor that is installed so as to sandwich the conveying mechanism 13 from above and below and can intermittently measure the cross-sectional shape of the long body L being conveyed at any intervals can be used.

[0030] As described above, the calculation unit 7 receives data acquired by the first reader 4a, the second reader 4b, the first measuring device 6a, the second measuring device 6b, the weighing scale 5, and the profile sensor 5a. Data on the weight per unit length of the elongated body L and the target range AR of the cross-sectional shape (cross-sectional area) are input and stored in the calculation unit 7, along with various other data. The calculation unit 7 performs various calculation processes using the input data. The calculation unit 7 is connected to the control unit 10 via wire or wirelessly so as to be able to communicate with it.

[0031] The control unit 10 controls the length adjustment mechanism 8. The control unit 10 may also be configured to control other devices that make up the manufacturing system 1. In this embodiment, the control unit 10 also controls the conveying mechanism 13, the cutting machine 14b, and the molding machine 15.

[0032] Known computers can be used as the calculation unit 7 and the control unit 10. One computer may function as the calculation unit 7 and the control unit 10, or each may be configured as a separate computer.

[0033] The length adjustment mechanism 8 adjusts the length of the long body L while the long body L is being supplied to the drum body 15a. In this embodiment, the length adjustment mechanism 8 has a pressure roller 9a, an actuator 9b, and ring members 9d and 9e that connect the pressure roller 9a and the actuator 9b.

[0034] More specifically, the length adjustment mechanism 8A shown in Fig. 4 includes a pressure roller 9a disposed above the drum body 15a, an actuator 9b equipped with a reciprocating rod 9c, a link member 9d for rotating the pressure roller 9a, and a link member 9e for connecting the link member 9d and the rod 9c. The columnar or cylindrical pressure roller 9a has a length set to be equal to or greater than the overall width of the elongated body L, and is rotatably supported at the tip of the L-shaped link member 9d. The rear end of the link member 9d is rotatably supported at the frame of the conveying mechanism 13. The corner of the L-shaped link member 9d and the tip of the rod 9c are rotatably connected via the link member 9e.

[0035] When the rod 9c is moved forward, the pressure roller 9a pivots downward about the support shaft at the rear end of the link member 9d, approaching the outer circumferential surface of the drum body 15a, and when the rod 9c is moved backward, the pressure roller 9a pivots upward, moving away from the outer circumferential surface of the drum body 15a. Therefore, if a long object L is wrapped around the outer circumferential surface of the drum body 15a, the long object L is sandwiched and pressed between the outer circumferential surface of the drum body 15a and the pressure roller 9a moving toward this outer circumferential surface. The greater the forward movement of the rod 9c, the greater the pressing force F, and the magnitude of the pressing force F changes depending on the degree of advancement and retreat of the rod 9c.

[0036] The conveying speed V1 of the long body L by the conveying mechanism 13 and the rotation speed V2 of the drum body 15a are set to be substantially the same, and the long body L is supplied to the drum body 15a while being pressed against the outer circumferential surface of the drum body 15a by the pressure roller 9a, so that it is wound around the drum body 15a. Note that this rotation speed V2 is the peripheral speed of the outer circumferential surface of the drum body 15a. In this way, it has been found that in the process of supplying the long body L to the drum body 15a, the greater the pressing force F, the greater the stretching of the long body L.

[0037] Therefore, by controlling the forward and backward movement of the rod 9c to adjust the pressing force F, it is possible to perform a length adjustment operation on the elongated body L being wound around the drum body 15a. That is, with this length adjustment mechanism 8A, the length adjustment operation is performed by adjusting the pressing force F when the elongated body L is pressed against the drum body 15a while the drum body 15a is rotated to wind the elongated body L. Since the correlation between the magnitude of the pressing force F and the change in the length of the elongated body L differs for each type (specification) of the elongated body L, it is advisable to understand this correlation in advance for each type (specification) of the elongated body L. Then, the length adjustment operation is performed using this correlation.

[0038] In this embodiment, a fluid cylinder is used as the actuator 9b, and the cylinder rod (rod 9c) is used to move the pressure roller 9a to change the pressure force F, but this is not the only way to change the pressure force F. For example, it is also possible to use a rod 9c that is moved back and forth by a servo motor to move the pressure roller 9a toward and away from the outer circumferential surface of the drum body 15a to change the pressure force F.

[0039] It is possible to know in advance how much the weight per unit length of the long body L will change (decrease) when the long body L is stretched. Therefore, the correlation between the change in length of the long body L and the change in weight per unit length of the long body L is known in advance, and this correlation is used to perform the length adjustment operation. That is, in this embodiment, the correlation between the magnitude of the pressing force F and the change in weight per unit length of the long body L is used to appropriately perform the length adjustment operation of the long body L, thereby making it possible to bring the weight per unit length of the long body L into the target range AR.

[0040] Furthermore, it is possible to know in advance how much the cross-sectional shape of the elongated body L will change depending on how much the elongated body L is stretched. Therefore, it is possible to know in advance the correlation between the degree of change in the length of the elongated body L and the degree of change in the cross-sectional shape of the elongated body L, and perform a length adjustment operation using this correlation. That is, in this embodiment, by appropriately performing the length adjustment operation of the elongated body L using the correlation between the magnitude of the pressing force F and the degree of change in the cross-sectional shape of the elongated body L, it is possible to bring the cross-sectional shape (cross-sectional area) of the elongated body L into the target range AR.

[0041] Next, the procedure of the tire manufacturing method of the present invention using the manufacturing system 1 will be described using as an example a case where the long body L is manufactured by extruding unvulcanized rubber R.

[0042] As shown in Fig. 1, a kneader 11 kneads a plurality of types of raw materials M (raw rubber, various compounding agents) to produce unvulcanized rubber R. A Banbury mixer or the like is used as the kneader 11. The produced unvulcanized rubber R is fed into an extruder 12 for the next process by a transport mechanism 13 such as a belt conveyor.

[0043] The extruder 12 adjusts the viscosity of the unvulcanized rubber R to an appropriate level, extrudes the rubber R from a die at the tip into a predetermined cross-sectional shape, and forms the rubber into a long body L. The unvulcanized rubber R can be made into a sheet-like long body L using a rolling device, or the unvulcanized rubber R can be integrated with a large number of aligned reinforcing cords to form a sheet-like long body L. The manufactured long body L is transported to a stock means 14a by a transport mechanism 13, such as a belt conveyor, arranged in front of the extruder 12. The transport speed of the long body L is constantly monitored and controlled by the control unit 10.

[0044] The stock means 14a temporarily stores the elongated body L until it is needed in the next process. For example, a winding drum device that winds up the elongated body L together with the liner is used as the stock means 14a. In the case of a direct extrusion / molding line in which the manufactured elongated body L is used immediately in the next process, the stock means 14a is not necessary.

[0045] When needed to mold the green tire G, the long body L is unwound from the stock means 14a, conveyed by a conveying mechanism 13 such as a belt conveyor, and supplied to the molding machine 15. In the molding machine 15, various tire components E including the tire component E1 are integrated on a drum body 15a to mold the green tire G. Next, the green tire G is vulcanized by a vulcanization device 16, and a tire T shaped into a predetermined shape is manufactured by a vulcanization mold 17.

[0046] As illustrated in FIGS. 2 and 3 , when a long body L is manufactured in the conveying section from the extruder 12 to the stock means 14a, a marking machine 2 sequentially applies identification marks 3 to the surface of the long body L as it is conveyed, in each range S corresponding to the individual size of a single tire. Each of the applied identification marks 3 is sequentially read by a first reader 4a. Furthermore, a first measuring machine 6a sequentially measures the initial separation distance D1 between the identification marks 3 applied to adjacent ranges S for the long body L as it is conveyed. Each initial separation distance D1 is associated with a corresponding identification mark 3 (which may be the identification mark 3 at the start or end of the initial separation distance D1) and stored in the calculation unit 7.

[0047] In this embodiment, the weight of each of the elongated objects L being transported is measured within a range corresponding to the initial separation distance D1. Each measured weight is associated with the corresponding identification mark 3 (which may be the identification mark 3 at the start or end of the initial separation distance D1) and stored in the calculation unit 7.

[0048] Furthermore, the profile sensor 5a measures the cross-sectional shape of at least one point within the range corresponding to the initial separation distance D1 of each of the elongated bodies L being transported. Each of the measured cross-sectional shapes is associated with a corresponding identification mark (which may be the identification mark 3 that is the start point or the identification mark 3 that is the end point of the initial separation distance D1) and stored in the calculation unit 7.

[0049] In the conveying section from the stock means 14a to the molding machine 15, when the green tire G is being molded, the second reader 4b sequentially reads each identification mark 3 in the process of supplying the long body L to the drum body 15a. In addition, the in-use separation distance D2 between the identification marks 3 affixed to adjacent ranges S of the long body L being conveyed and moved is sequentially measured. Each in-use separation distance D2 is linked to the corresponding identification mark 3 (which may be the identification mark 3 that is the start point or the identification mark 3 that is the end point of the in-use separation distance D2) and input to the calculation unit 7.

[0050] The calculation unit 7 calculates the difference D (D=D1-D2) between each stored initial separation distance D1 and the corresponding in-use separation distance D2. That is, the calculation unit 7 calculates the difference D between the initial separation distance D1 and the in-use separation distance D2, the start point (or end point) of which is the same identification mark 3. This makes it possible to grasp the amount of shrinkage over time (i.e., the magnitude of the difference D) in the range corresponding to each in-use separation distance D2 from the time the long body L is manufactured until the green tire G is molded.

[0051] As shown in FIG. 4, during the process of feeding the elongated object L to the drum body 15a, the control unit 10 controls the advancement and retreat of the rod 9c to adjust the magnitude of the pressing force F based on the magnitude of the difference D calculated by the calculation unit 7. The length adjustment mechanism 8A then performs a length adjustment operation so that the weight per unit length of the range corresponding to the in-use separation distance D2 corresponding to each calculated difference D falls within the target range AR. For example, the larger the difference D, the greater the contraction of the range corresponding to the in-use separation distance D2 corresponding to that difference D, resulting in a weight per unit length greater than the target range AR. Therefore, the length adjustment operation is performed to increase the amount of stretching for the range corresponding to the in-use separation distance D2 corresponding to that difference D. By performing this length adjustment operation, the weight per unit length of the elongated object L can be accurately adjusted to the target range AR.

[0052] When the profile sensor 5a is used, as illustrated in FIG. 4, during the process of feeding the elongated object L to the drum body 15a, the control unit 10 controls the advancement and retreat of the rod 9c to adjust the magnitude of the pressing force F based on the magnitude of the difference D calculated by the calculation unit 7. The length adjustment mechanism 8A then performs a length adjustment operation so that the weight per unit length and cross-sectional shape for the range corresponding to the in-use separation distance D2 corresponding to each calculated difference D fall within the target range AR. For example, the larger the difference D, the greater the contraction of the range corresponding to the in-use separation distance D2 corresponding to that difference D, resulting in a greater weight per unit length and cross-sectional shape relative to the target range AR. Therefore, a length adjustment operation is performed to increase the amount of stretching for the range corresponding to the in-use separation distance D2 corresponding to that difference D. By performing this length adjustment operation, the weight per unit length and cross-sectional shape (cross-sectional area) of the elongated object L can be accurately adjusted to the target range AR.

[0053] The elongated body L, which has been adjusted in length and wound around the drum body 15a once in this manner, is cut by the cutting machine 14b into individual tire-sized lengths to form the tire component E1. This reduces the variation in weight of the green tire G formed using this tire component E1. Accordingly, the variation in weight of the tire T manufactured by vulcanizing this green tire G is also reduced. This reduces the variation in tire weight caused by the shrinkage over time of the tire component E1 formed by cutting this elongated body L during the tire manufacturing process.

[0054] Furthermore, the tire component E1, which is obtained by cutting the elongated body L wound around the drum body 15a into individual tire-sized lengths, is formed into a ring shape without being stretched separately. Therefore, the weight variation in the tire component E1 in the tire circumferential direction of the green tire G is suppressed. As a result, excellent uniformity can be ensured in the manufactured tire T.

[0055] The present invention is not limited to pneumatic tires, and can be used when manufacturing various other types of tires T.

[0056] In this embodiment, the weight of the range in which the initial distance D1 is measured is determined (estimated) based on advance data according to each initial distance D1. Therefore, it is not necessary to actually measure the weight of the range corresponding to each initial distance D1. However, since this determined (estimated) weight has an error compared to the actual weight, it is preferable to use the weight measured in the range corresponding to each initial distance D1 when manufacturing the elongated body L.

[0057] When the elongated body L is manufactured, the weights measured in the ranges corresponding to the initial separation distances D1 are linked to the corresponding identification marks 3 (which may be the identification marks 3 that are the start and end points of the initial separation distances D1) and stored in the calculation unit 7. Based on the magnitude of each measured weight, the length adjustment mechanism 8A performs a length adjustment operation for the ranges corresponding to the in-use separation distances D2 corresponding to the ranges in which the weights were measured. In this way, performing the length adjustment operation in consideration of the measured weights in the ranges corresponding to the initial separation distances D1 is even more advantageous in accurately adjusting the weight per unit length of the elongated body L to the target range AR.

[0058] Furthermore, the cross-sectional shape of the range where the initial separation distance D1 is measured is determined (estimated) based on advance data according to each initial separation distance D1. Therefore, it is not necessary to actually measure the cross-sectional shape of the range corresponding to each initial separation distance D1. However, since this determined (estimated) cross-sectional shape has an error compared to the actual cross-sectional shape, it is preferable to use the cross-sectional shape measured by the profile sensor 5a at at least one location within the range corresponding to each initial separation distance D1 when manufacturing the elongated body L.

[0059] When the elongated body L is manufactured, the cross-sectional shape measured at at least one location within the range corresponding to each initial separation distance D1 is associated with the corresponding identification mark 3 (which may be the identification mark 3 at the start or end of the initial separation distance D1) and stored in the calculation unit 7. Based on each measured cross-sectional shape, a length adjustment operation is performed by the length adjustment mechanism 8A for the range corresponding to each in-use separation distance D2 corresponding to the range in which the cross-sectional shape was measured. In this way, performing the length adjustment operation in consideration of the measured cross-sectional shape of the range corresponding to each initial separation distance D1 is even more advantageous in accurately adjusting the cross-sectional shape of the elongated body L to the target range AR.

[0060] The length adjustment mechanism 8 that performs the length adjustment operation on the elongated body L is not limited to the above-mentioned specifications, and various specifications can be adopted. Another embodiment of the length adjustment mechanism 8 (8B, 8C, 8D) will be described with reference to Figs. 5 to 7.

[0061] 5 includes a conveying mechanism 13 that conveys the long body L to a drum body 15a, and a molding machine 15. The conveying speed V1 of the long body L by the conveying mechanism 13 and the rotation speed V2 of the drum body 15a can be controlled independently.

[0062] The long body L is supplied to the drum body 15a by the conveying mechanism 13 while the drum body 15a is rotated, and the pressing force F applied to the long body L by the pressure roller 9a is kept constant (a predetermined value), so that the long body L is wound around the drum body 15a. In this process of supplying the long body L to the drum body 15a, as long as the conveying speed V1 and the rotational speed V2 are the same, the length of the long body L does not substantially change depending on the speeds of the two. However, the faster the rotational speed V2 is relative to the conveying speed V1, the more the long body L is stretched before being wound around the drum body 15a. If the conveying speed V1 is slower than the rotational speed V2, it is also possible to shrink the long body L being wound around the drum body 15a.

[0063] Therefore, by adjusting the difference between the conveying speed V1 and the rotational speed V2, the length of the long body L wound around the drum body 15a can be adjusted. That is, in this length adjustment mechanism 8B, the length adjustment operation is performed by adjusting the difference between the conveying speed V1 when the long body L is supplied to the drum body 15a and the rotational speed V2 of the drum body 15a. Since the correlation between the magnitude of the difference between the conveying speed V1 and the rotational speed V2 and the change in the length of the long body L varies depending on the type (specification) of the long body L, it is advisable to understand this correlation in advance for each type (specification) of the long body L. Then, the length adjustment operation is performed using this correlation.

[0064] During the process of feeding the long object L to the drum 15a, the control unit 10 adjusts the difference between the conveying speed V1 and the rotation speed V2 based on the magnitude of the difference D between the initial separation distance D1 and the corresponding in-use separation distance D2. This adjusts the length so that the weight per unit length of the long object L falls within the target range AR for the range corresponding to the in-use separation distance D2. The long object L, which has been wound around the drum 15a once, is then cut into individual pieces the size of a single tire by the cutter 14b.

[0065] The length adjustment mechanism 8C shown in Fig. 6 has a conveying mechanism 13 that conveys the long body L to a drum body 15a, and a dancer amount sensor 9f. Two conveying mechanisms 13 are arranged at an interval in the longitudinal direction (conveying direction), forming a gap between them. The conveyed long body L hangs down in this gap, and this hanging amount becomes the dancer amount H. The dancer amount H is detected by the dancer amount sensor 9f and input to the calculation unit 7. The conveying speeds V1a and V1b of the long body L by each of the vertically arranged conveying mechanisms 13 can be controlled individually.

[0066] The long body L is supplied to the drum 15a by each conveying mechanism 13 while the drum 15a is rotated. The pressing force F of the pressure roller 9a on the long body L is maintained at a predetermined (constant) value, and the long body L is wound around the drum 15a. The difference between the conveying speed V1a of the forward conveying mechanism 13 and the rotational speed V2 of the drum 15a is maintained constant. In this process of supplying the long body L to the drum 15a, if the conveying speeds V1a and V1b are the same, the dance amount H of the long body L does not substantially change due to the speeds of the two. However, as the conveying speed V1b is made faster relative to the conveying speed V1a, the dance amount H increases, and the weight of the hanging portion of the long body L acts as a greater tensile force on the long body L wound around the drum 15a. This tensile force stretches the long body L wound around the drum 15a. When the conveying speed V1b is made slower than the conveying speed V1a, the dancer amount H decreases, and the tensile force acting on the long body L wound around the drum body 15a decreases. The amount of stretching of the long body L wound around the drum body 15a changes depending on the magnitude of the tensile force acting.

[0067] Therefore, by adjusting the difference between the conveying speeds V1a and V1b to adjust the dancer amount H, it is possible to perform a length adjustment operation on the long body L wound around the drum body 15a. That is, in this length adjustment mechanism 8C, the length adjustment operation is performed by adjusting the dancer amount H of the long body L formed in the supply path that supplies the long body to the L drum body 15a. Since the correlation between the magnitude of the dancer amount H and the degree of change in the length of the long body L differs for each type (specification) of the long body L, it is advisable to understand this correlation in advance for each type (specification) of the long body L. Then, the length adjustment operation is performed using this correlation.

[0068] During the process of supplying the long body L to the drum body 15a, the control unit 10 adjusts the difference between the conveying speed V1a and the conveying speed V1b to control the dancer amount H based on the magnitude of the difference D between the initial separation distance D1 and the corresponding in-use separation distance D2. As a result, a length adjustment operation is performed so that the weight per unit length and cross-sectional shape of the long body L fall within the target range AR for the range equivalent to the in-use separation distance D2. Thereafter, the long body L wound around the drum body 15a once is cut into individual pieces the size of one tire by the cutter 14b.

[0069] The length adjustment mechanism 8D illustrated in FIG. 7 is configured with a conveying mechanism 13 equipped with multiple rotational support rollers 13a that are driven to rotate. In this conveying mechanism 13, which conveys the long object L to a drum body 15a, the rotational speeds Va, Vb, Vc, and Vd of each of the rotational support rollers 13a arranged side by side in the conveying direction can be individually controlled. The more rotational support rollers 13a there are, the better. For example, a configuration is adopted in which more than half of the length of the range S of the long object L, equivalent to the individual size of a single tire, and more preferably the entire length, are supported by the rotational support rollers 13a. Note that these rotational speeds Va, Vb, Vc, and Vd are the peripheral speeds at the outer circumferential surfaces of the rotational support rollers 13a.

[0070] While supplying the long body L to the drum body 15a by the conveying mechanism 13 and rotating the drum body 15a, the pressing force F by the pressing roller 9a on the long body L is set to a predetermined value (constant), and the long body L is wound around the drum body 15a. The rotational speed Va of the foremost rotation support roller 13a and the rotational speed V2 of the drum body 15a are made substantially the same. In the process of supplying the long body L to the drum body 15a like this, if the rotational speeds Va, Vb, Vc, Vd of all the rotation support rollers 13a are the same, the length of the long body L does not substantially change due to the rotational speeds of these rotation support rollers 13a. However, for example, if the rotational speed is increased as the rotation support roller 13a arranged in the front is approached (Va > Vb > Vc > Vd), the conveyed long body L is stretched more, and as the speed difference between them becomes larger, it is stretched more. If the rotational speed is decreased as the rotation support roller 13a arranged in the front is approached (Va < Vb < Vc < Vd), it becomes possible to contract the conveyed long body L.

[0071] Therefore, by adjusting the differences in the rotational speeds Va, Vb, Vc, Vd of each of the rotation support rollers 13a, a length adjustment operation can be performed on the long body L wound around the drum body 15a. That is, in this length adjustment mechanism 8D, changing the conveyance speed distribution with respect to the conveyance direction in the conveying mechanism 13 that supplies the long body L to the drum body 15a becomes the length adjustment operation. Since the correlation between the magnitude of the differences in the rotational speeds Va, Vb, Vc, Vd of each of the rotation support rollers 13a and the change in the length of the long body L is different for each type (specification) of the long body L, it is advisable to grasp this correlation in advance for each type (specification) of the long body L. Then, the length adjustment operation is performed using this correlation.

[0072] During the process of feeding the long object L to the drum 15a, the control unit 10 adjusts the difference in the rotational speeds Va, Vb, Vc, and Vd of the rotation support rollers 13a based on the magnitude of the difference D between the initial separation distance D1 and the corresponding in-use separation distance D2. This adjusts the length of the long object L so that the weight per unit length and cross-sectional shape fall within the target range AR for the range corresponding to the in-use separation distance D2. The long object L, which has been wound around the drum 15a once, is then cut into individual pieces the size of a single tire by the cutter 14b.

[0073] The length adjustment operations by the length adjustment mechanisms 8 illustrated in FIGS. 4 to 7 can be performed not only individually but also in combination with a plurality of these length adjustment mechanisms 8 (length adjustment operations). [Explanation of symbols]

[0074] 1. Manufacturing System 2 Marking machine 3 Identification Mark 4a First Leader 4b Second Leader 5 Weight scale 5a Profile sensor 6a First measuring device 6b Second measuring device 7 Arithmetic section 8 (8A, 8B, 8C, 8D) Length adjustment mechanism 9a Pressure roller 9b Actuator 9c rod 9d, 9e Link members 9f Dancer quantity sensor 10 Control Unit 11 Kneader 12 Extruder (long body manufacturing machine) 13 Conveyor mechanism 13a Rotation support roller 14a Stocking Methods 14b cutting machine 15 Molding machine 15a drum body 16 Vulcanization equipment 17 Vulcanization mold G Green Tire T Vulcanized tires L Long body E (E1, E2, E3, E4, ...) Tire components R Unvulcanized rubber M Raw materials

Claims

1. A tire manufacturing method in which a green tire is manufactured by integrating a plurality of types of tire components, including tire components each having a size equivalent to one tire, which are obtained by cutting a long body wound on a drum body, and vulcanizing the green tire, When the elongated body is manufactured, an identification mark is attached to each range of the elongated body corresponding to the individual size of one tire, and each of the identification marks is read and a distance between the identification marks attached to the ranges corresponding to adjacent individual sizes in the longitudinal direction of the elongated body is measured, and each of the measured distances is set as an initial distance, linked to each corresponding identification mark, and stored in a calculation unit. A tire manufacturing method in which, when molding the green tire, each of the identification marks is read in the process of supplying the long body to a drum body, and the distance between the identification marks attached in the range corresponding to the individual sizes adjacent in the longitudinal direction of the long body is measured, and this distance is input into the calculation unit as the in-use separation distance, and the calculation unit calculates the difference between each of the initial separation distances and the corresponding in-use separation distances, and in the process of supplying the long body to the drum body, a length adjustment operation is performed based on the magnitude of each calculated difference so that the weight per unit length is within a target range for the range corresponding to each of the in-use separation distances corresponding to each difference, and the long body wrapped around the drum body is cut into individual sizes for one tire.

2. 2. A tire manufacturing method as described in claim 1, wherein, when the long body is manufactured, the weight of the range corresponding to each of the initial separation distances is measured, each of the weights is linked to the corresponding identification mark and stored in the calculation unit, and the length adjustment operation is performed for the range corresponding to each of the corresponding separation distances during use based on the magnitude of each of the weights.

3. 3. A tire manufacturing method as described in claim 1 or 2, wherein, when the elongated body is manufactured, the cross-sectional shape of at least one location within a range corresponding to each of the initial separation distances is measured, and each of the cross-sectional shapes is linked to each of the corresponding identification marks and stored in the calculation unit, and the length adjustment operation is performed for the range corresponding to each of the corresponding in-use separation distances based on each of the cross-sectional shapes.

4. The tire manufacturing method according to any one of claims 1 to 3, wherein the length adjustment operation comprises adjusting the magnitude of the pressing force when the elongated body is pressed against the outer peripheral surface of the drum body while the drum body is rotated and wound around the elongated body.

5. The tire manufacturing method according to any one of claims 1 to 4, wherein the length adjustment operation is to adjust the difference between the conveying speed when the long body is supplied to the drum body and the rotation speed of the drum body.

6. The tire manufacturing method according to any one of claims 1 to 5, wherein the length adjustment operation is to adjust the amount of dancer of the long body formed in the supply path when the long body is supplied to the drum body.

7. The method for manufacturing a tire according to any one of claims 1 to 6, wherein the length adjusting operation is to change a conveying speed distribution in a conveying direction of a conveying mechanism that supplies the long body to the drum body.

8. The method for manufacturing a tire according to any one of claims 1 to 7, wherein the elongated body is a tire component manufactured by extruding unvulcanized rubber or a tire component manufactured by rolling unvulcanized rubber.

9. A tire manufacturing system comprising component manufacturing equipment for manufacturing each of a plurality of types of tire components, molding equipment for integrating the plurality of types of tire components to form a green tire, and vulcanization equipment for vulcanizing the green tire, wherein each of the component manufacturing equipment includes a long body manufacturing machine for manufacturing a long body, and a cutting machine for cutting the long body wound around a drum body into the tire components of individual sizes for one tire, a marking machine that, when the long body is manufactured, applies an identification mark to each area of ​​the long body that corresponds to the individual size of one tire; a first reader that reads each of the identification marks; a first measuring machine that measures, as an initial separation distance, a distance between the identification marks applied to areas that correspond to adjacent individual sizes in the longitudinal direction of the long body; a calculation unit that associates and stores each of the initial separation distances with the corresponding identification marks; a second reader that, when the green tire is built, reads each of the identification marks in the process of supplying the long body to a drum body; a second measuring machine that measures, as an in-use separation distance, a distance between the identification marks applied to areas that correspond to adjacent individual sizes in the longitudinal direction of the long body; a length adjustment mechanism that performs a length adjustment operation on the long body in the process of supplying the long body to the drum body; and a control unit that controls the length adjustment mechanism, The calculation unit calculates the difference between each of the initial separation distances and the corresponding separation distances during use, and in the process of supplying the long body to the drum body, the control unit controls the length adjustment mechanism to perform a length adjustment operation based on the magnitude of each difference so that the weight per unit length falls within a target range for the range equivalent to each of the separation distances during use corresponding to each of the differences, thereby winding the long body onto the drum body, and the long body wound onto the drum body is cut into the individual sizes by the cutting machine.

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