Method and apparatus for manufacturing unvulcanized rubber member

Abstract

To provide a method and equipment for manufacturing an unvulcanized rubber member that can more easily adjust the length of a strip-shaped unvulcanized rubber member to be wound onto a drum body to a target range across the width direction.SOLUTION: A plurality of rollers 4 are arranged side by side in the width direction of a strip-shaped unvulcanized rubber member R to be wound on a drum body 11, a pressing force F of each roller 4 against the unvulcanized rubber member R is set based on a comparison of a measured data D across the width direction of the length of the unvulcanized rubber member R and a target range G data, and the length of the unvulcanized rubber member R is adjusted to the target range G across the width direction by rolling the unvulcanized rubber member R around the drum body 11 and stretching it while letting each roller 4 rotate freely with a central axis 4z as the center and rolling the roller on the unvulcanized rubber member R in the longitudinal direction, in the state where the set pressing force F is applied to the unvulcanized rubber member R by each roller 4, thereby joining a front end Ra and a rear end Rb to form a circular rubber member RC.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method and apparatus for manufacturing unvulcanized rubber members, and more specifically to a method and apparatus for manufacturing unvulcanized rubber members that can precisely adjust the length of a strip-shaped unvulcanized rubber member wound around a drum body within a target range across the width. [Background technology]

[0002] In the manufacture of rubber products such as tires, various strip-shaped unvulcanized rubber materials are used, and there is a process of winding them around a forming drum or the like to form them into a ring. If the length of the unvulcanized rubber material is too short or too long, defects such as gaps at the joints between the longitudinal front and rear ends or excessive overlap occur when the material is formed into a ring. If the length of the unvulcanized rubber material varies across the width, these defects will occur in a widthwise variation, affecting the uniformity of the tire.

[0003] Various devices have been proposed to solve these problems (see, for example, Patent Document 1). In the device proposed in Patent Document 1, the contracted portion at the front end of the unvulcanized rubber material, which contracts the most, is stretched by a stretching device and then attached to the outer circumferential surface of a forming drum (see paragraphs 0022-0024, etc.). In this stretching device, the contracted portion is sandwiched and held between a presser member and a support base to prevent the contraction of the contracted portion. In this state, the presser member is rotated to stretch the contracted portion. However, even if only the contracted portion of the unvulcanized rubber material, which contracts the most, is stretched, it is difficult to achieve an unvulcanized rubber material with an exact length across the width. Therefore, there is room for improvement in accurately adjusting the length of the unvulcanized rubber material to a target range across the width. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-136826 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a method and apparatus for manufacturing an unvulcanized rubber member that can accurately adjust the length of a strip-shaped unvulcanized rubber member to be wound around a drum body within a target range across the width. [Means for solving the problem]

[0006] In order to achieve the above object, the manufacturing method of the unvulcanized rubber member of the present invention is a manufacturing method of an unvulcanized rubber member in which the length of a band-shaped unvulcanized rubber member wound on a drum body is adjusted to a target range across the width direction, the manufacturing method of an unvulcanized rubber member includes arranging a plurality of rollers in the width direction, and setting a pressing force of each of the rollers against the unvulcanized rubber member based on a comparison between measurement data of the length across the width direction and data of the target range, With the pressing force being applied to the unvulcanized rubber material by each of the rollers, the unvulcanized rubber material is wound around the drum body while each of the rollers rolls on the unvulcanized rubber material in the longitudinal direction, thereby adjusting the length to the target range across the width direction. In this case, each of the rollers is supported by a support shaft, and a weight that moves together with the rod is provided for each of the rollers, and by moving each of the rods in the rod axial direction, each of the rollers is rotated around each of the support shafts by the weight of each of the weights, thereby applying the pressing force. It is characterized by:

[0007] The manufacturing apparatus for unvulcanized rubber members of the present invention adjusts the length of a band-shaped unvulcanized rubber member wound around a drum body to a target range across the width direction, and includes a measuring device that measures the length across the width direction, a control unit to which data of the target range is input, and a plurality of rollers arranged side by side in the width direction. a support shaft supporting each of the rollers; a weight that moves together with a rod provided for each of the rollers; the control unit compares the measurement data across the width direction of the length measured by the measuring device with the data of the target range, and sets the pressing force of each of the rollers against the unvulcanized rubber member based on the comparison result; The rods are moved in the rod axial direction, whereby the rollers are rotated around the support shafts by the weights of the weights, thereby applying the pressing force;The rollers roll longitudinally on the unvulcanized rubber material while applying the pressing force to the unvulcanized rubber material, and the unvulcanized rubber material is wound around the drum body, thereby adjusting the length to the target range across the width. [Effects of the Invention]

[0008] According to the present invention, the pressing force for each roller is set based on a comparison of measurement data across the width of the unvulcanized rubber material with data for a target range. Then, each roller is rolled longitudinally over the unvulcanized rubber material while applying a pressing force, and the unvulcanized rubber material is wound around a drum. Therefore, the length of the unvulcanized rubber material at the widthwise position corresponding to each roller can be accurately adjusted to the target range. Adjusting the length using multiple rollers aligned in the widthwise direction of the unvulcanized rubber material is advantageous in suppressing widthwise variation in the length relative to the target range. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is an explanatory diagram illustrating an example of a manufacturing apparatus for an unvulcanized rubber member according to the present invention in a plan view. [Figure 2] 2 is an explanatory view illustrating a manufacturing apparatus as viewed from the AA cross section of FIG. 1. [Figure 3] FIG. 2 is an enlarged view of the roller and its surroundings in FIG. [Figure 4] 4 is an explanatory diagram illustrating the regions shown in FIG. 3 in a side view. FIG. [Figure 5] 4 is an explanatory side view illustrating a state in which the weight in FIG. 3 is moved forward to adjust the length of the rubber member. FIG. [Figure 6] 10 is a graph illustrating the relationship between the amount of forward movement of the rod and the amount of elongation of the rubber member. FIG. [Figure 7] 10 is an explanatory diagram illustrating, in plan view, a manufacturing device in which a rubber member is wound around a drum body while adjusting its length. FIG. [Figure 8] 8 is an explanatory diagram illustrating the manufacturing apparatus of FIG. 7 as seen from the side. [Figure 9] 8 is an explanatory diagram illustrating, in plan view, a joining portion between a front end portion and a rear end portion of the rubber member of FIG. 7 when the rubber member is molded into an annular shape. FIG. [Figure 10] FIG. 10 is an explanatory side view of the annular rubber member of FIG. 9. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, a method and apparatus for producing an unvulcanized rubber member according to the present invention will be described based on the embodiments shown in the drawings.

[0011] The embodiment of the manufacturing apparatus 1 for an unvulcanized rubber member (hereinafter referred to as the manufacturing apparatus 1) illustrated in FIGS. 1 to 4 adjusts the length of a strip-shaped unvulcanized rubber member R (hereinafter referred to as the rubber member R) wound around a drum body 11 to within a target range G across the width direction. This rubber member R is cut to a predetermined length (the length required for one tire) in a previous process, but since the length changes due to factors such as shrinkage over time, the manufacturing apparatus 1 is used to adjust the length to within the target range G. Examples of the rubber member R include various tire components such as tread rubber and side rubber of a tire made only of unvulcanized rubber, and carcass material in which reinforcing wires are embedded in unvulcanized rubber, but are not limited to these.

[0012] The manufacturing apparatus 1 includes a transport conveyor 2, a plurality of rollers 4 (4a to 4e), a measuring device 9 (length sensor 9) that measures the length of the rubber member R, and a control unit 10. A drum body 11 is disposed in front of the manufacturing apparatus 1. Various known molding drums and rigid cores are used for the drum body 11. The drum body 11 rotates around a drum axis 12.

[0013] The transfer conveyor 2 can be any of various known conveyors capable of transferring the placed rubber member R toward the drum body 11. In this embodiment, the transfer conveyor 2 has a conveyor belt 2a stretched between front and rear pulleys, and the conveyor belt 2a is rotationally driven by a drive source such as a servo motor.

[0014] The direction of the arrow L in the drawing indicates the longitudinal direction of the rubber member R (the front-rear direction of the rubber member R and the transport conveyor 2). The direction of the arrow W indicates the width direction of the rubber member R placed on the transport conveyor 2 (the width direction of the transport conveyor 2 and the drum body 11).

[0015] Above the transport conveyor 2, two support frames 3 and one support shaft 8 are provided, extending in the width direction W and crossing the transport conveyor 2. The support frames 3 are spaced apart in the longitudinal direction L. The support shaft 8 is located at the front end of the transport conveyor 2, and is positioned forward of the support frames 3.

[0016] Each roller 4 (4a to 4e) is attached rotatably around a support shaft 8, and is aligned in the width direction W and fixed at a desired position in the width direction W. Each roller 4 applies a pressing force F set for each roller 4 to the rubber member R. That is, the rubber member R is pressed by each roller 4 with the set pressing force F.

[0017] The number of rollers 4 to be arranged is not limited to five and is set appropriately depending on the overall width dimension and shrinkage characteristics of the rubber member R. For example, 2 to 8 or 3 to 6 rollers 4 are arranged in parallel in the width direction W. In this embodiment, all of the rollers 4 have the same specifications, but rollers 4 with different specifications (width and outer diameter) can also be mixed.

[0018] In this embodiment, each roller 4 is detachable from the support shaft 8, allowing a desired number of rollers 4 to be attached to the support shaft 8. The rollers 4 are slidable in the extension direction of the support shaft 8 (width direction W), so that the rollers 4 can be slid to a desired position in the width direction W and fixed at the desired position in the width direction W.

[0019] To describe the rollers 4 in this embodiment in more detail, each roller 4 is rotatably attached via an individual base portion 7 supported on a support shaft 8. An actuator 5 and a weight 6 are mounted on each base portion 7. Thus, each roller 4 is provided with its own dedicated actuator 5 and weight 6. As the actuator 5, various known actuators 5 can be used, such as various fluid cylinders such as hydraulic cylinders, or a mechanism that moves a rod 5a back and forth using a servo motor.

[0020] The weight 6 is connected to the tip of the rod 5a of the actuator 5. The weight 6 is preferably designed to be detachable from the tip of the rod 5a. The rod 5a moves forward and backward in the rod axial direction (longitudinal direction L). In this embodiment, all of the weights 6 have the same specifications, but weights 6 of different specifications (mass and shape) can also be mixed.

[0021] Each roller 4 rotates up and down around a support shaft 8 and freely rotates around a central axis 4z installed on the base portion 7. As illustrated in FIG. 4, the weight 6 located directly above the support shaft 8 slides forward on the base portion 7 when the rod 5a is advanced in the rod axial direction as illustrated in FIG. 5. As the center of gravity G of the weight 6 moves forward of the support shaft 8 and the distance x between the center of gravity G and the center of the support shaft 8 increases, the moment around the support shaft 8 due to the mass of the weight 6 increases, and the pressing force F of the roller 4 against the rubber member R increases. In other words, by changing the distance x (the amount of forward movement of the rod 5a), the magnitude of the pressing force F applied by the roller 4 against the rubber member R can be adjusted.

[0022] By varying only the forward movement amount (separation distance X) of the rod 5a under predetermined conditions and determining the amount of stretch of the rubber member R when the rubber member R is wound from the transfer conveyor 2 onto the drum body 11 while applying a pressing force F to the rubber member R, data D shown in FIG. 6 can be obtained. That is, there is a roughly linear correlation between the forward movement amount (separation distance X) and the amount of stretch of the rubber member R. In other words, the amount of stretch of the rubber member R increases when the pressing force F applied to the rubber member R increases.

[0023] The measuring device 9 can be any of various known devices capable of measuring the length of the rubber member R, and may be a contact type but a non-contact type is preferable. In this embodiment, a non-contact type length sensor is used as the measuring device 9, and the length sensor 9 is attached to each support frame 3. The detection data by the length sensor 9 is input to the control unit 10.

[0024] Two length sensors 9 are arranged in the same position in the width direction W on each support frame 3, forming a pair. The detection interval is measured from when the rear length sensor 9 of the pair detects the front end of the rubber piece R being conveyed forward until the front length sensor 9 detects the front end of the rubber piece R. Based on this detection interval and the forward moving speed of the rubber piece R (the conveying speed by the conveyor 2), the length of the rubber piece R at the position in the width direction W where the pair of length sensors 9 is arranged is calculated by the control unit 10 and becomes the measurement value (measurement data). By arranging multiple pairs of length sensors 9 in the width direction W, the length of the rubber piece R can be measured across the entire width of the rubber piece R. In this way, the length of the rubber piece R is measured across the entire width of the rubber piece R, so that variations in the length of the rubber piece R in the width direction W can be grasped.

[0025] In this embodiment, the length of the rubber member R is measured across the entire width of the rubber member R using multiple sets of length sensors 9 arranged in the width direction W, but the measurement method is not limited to this. If a single length sensor 9 can detect a wide range in the width direction W, a configuration in which only one set of length sensors 9 is arranged in the width direction W instead of multiple sets of length sensors 9 arranged in parallel can also be used.

[0026] Furthermore, in this embodiment, the length of the rubber member R is measured using a pair of two length sensors 9 arranged vertically in the length direction L, but the measurement method is not limited to this. It is also possible to measure the length of the rubber member R by arranging a single length sensor 9 instead of arranging multiple length sensors 9 vertically in the length direction L. For example, a single length sensor 9 arranged at a predetermined position in the length direction L detects the front and rear ends of the rubber member R being conveyed, and measures the detection interval time from when the front end is detected to when the rear end is detected. Based on this detection interval time and the forward movement speed of the rubber member R (the conveying speed by the conveyor 2), the control unit 10 calculates the length of the rubber member R at the position in the width direction W where the length sensor 9 is arranged, and sets this as the measurement value (measurement data).

[0027] The control unit 10 controls the movement of the components of the manufacturing apparatus 1. The control unit 10 receives detection data from the length sensor 9 and also receives data on the target length range G of the rubber member R. A known computer is used as the control unit 10. Data on the rotation speed of the drum body 11 is also input to the control unit 10. The correlation data D described above is also input to and stored in the control unit 10. In this embodiment, the movement of the drum body 11 is controlled by a control device separate from the control unit 10, but it is also possible to configure the control unit 10 to control the movement of the drum body 11.

[0028] An example of a procedure for manufacturing a rubber member R whose length across the width direction is adjusted to fall within the target range G according to the present invention will be described below.

[0029] 1 and 2, when the rubber member R is placed on the transport conveyor 2 and transported forward, the length sensor 9 acquires measurement data over the length of the rubber member R in the width direction W. In this embodiment, as illustrated in FIG. 1, the length of the rubber member R is longer at one end side in the width direction W (the side where roller 4a is arranged) than at the other end side (the side where roller 4e is arranged).

[0030] The control unit 10 compares the measurement data acquired by the length sensor 9 with pre-input data of the target range G of the length of the rubber member R to calculate the shortfall in the length of the rubber member R. That is, it grasps the distribution of the shortfall in the length of the rubber member R in the width direction W. Based on the calculated distribution of the shortfall in the length in the width direction W, the control unit 10 calculates and sets the pressing force F of the rollers 4 arranged at each width direction position against the rubber member R.

[0031] 6, data D of the correlation between the forward movement amount (pressing force F) of the rod 5a and the elongation amount of the rubber member R is obtained. Then, using this correlation data D, the forward movement amount (pressing force F) of each roller 4 required to compensate for the insufficient length of the rubber member R is set.

[0032] In this embodiment, the length of the rubber member R is longer at one end (the side where the roller 4e is arranged) in the width direction W than at the other end (the side where the roller 4a is arranged). Therefore, as illustrated in Fig. 7, the forward movement amount (pressing force F) of the rod 5a is set to be larger at one end in the width direction W. Therefore, the control unit 10 controls each rod 5a (weight 6) to move forward and backward by this forward movement amount.

[0033] With the pressing force F set by each roller 4 in this manner, the leading end portion Ra of the rubber member R is transported from the transport conveyor 2 onto the drum body 11, and is then positioned and fixed on the outer circumferential surface 11a. Various known methods may be used to position and fix the leading end portion Ra on the outer circumferential surface 11a of the drum body 11.

[0034] Next, as illustrated in Figures 7 and 8, the drum body 11 is rotated, and the conveyor belt 2a is rotated in synchronization with this rotation to wind the rubber material R around the outer peripheral surface 11a of the drum body 11. In this process, with each roller 4 applying a predetermined pressing force F to the rubber material R, the rollers 4 are rotated about the central axis 4z to roll on the rubber material R in the longitudinal direction L, thereby winding the rubber material R around the outer peripheral surface 11a of the drum body 11. If another material is already wound around the outer peripheral surface 11a of the drum body 11, the rubber material R is wound around the outer peripheral surface of the already-wrapped material. It is preferable that the peripheral speed of the rubber material R on the outer peripheral surface 11a and the conveying speed of the rubber material R by the transfer conveyor 2 are substantially the same.

[0035] Even if the rubber member R varies in length in the width direction W, the rubber member R is wound around the drum body 11 while being applied with a set pressing force F by each roller R. Therefore, the rubber member R is stretched according to the magnitude of the applied pressing force F, and its length is adjusted to the target range G across the width direction W.

[0036] When the drum body 11 rotates once, the front end portion Ra and the rear end portion Rb are joined together to form an annular rubber member R. As illustrated in Figures 9 and 10, the length of the rubber member R is adjusted to fall within the target range G across the width direction W, so the front end portion Ra and the rear end portion Rb are joined together without excess or deficiency. This makes it possible to manufacture an annular rubber member RC with excellent uniformity.

[0037] As described above, the rubber member R is wound around the drum body 11 while each roller 4 rolls on the rubber member R in the longitudinal direction L with a pressing force F set for each roller 4 based on a comparison of measurement data across the length of the rubber member R in the width direction W with data for the target range G. This allows the length of the rubber member R at a position in the width direction W corresponding to each roller 4 to be accurately adjusted to the target range G. Adjusting the length of the rubber member R using multiple rollers 4 aligned in the width direction W is advantageous in suppressing variation in the length in the width direction relative to the target range G. Even for rubber members R that shrink significantly over time, the length can be adjusted to the target range G, making it possible to reliably join the front end portion Ra and the rear end portion Rb when molding the rubber member R into an annular shape.

[0038] In this embodiment, a set pressing force F is applied to the rubber member R by each roller 4 on the transport conveyor 2 (conveyor belt 2a), but the position in the longitudinal direction L at which the pressing force F is applied is not limited to this. For example, the pressing force F can be applied at a position where the rubber member R is suspended in the air between the transport conveyor 2 (conveyor belt 2a) and the drum body 11. Alternatively, the pressing force F can be applied on the outer peripheral surface 11a of the drum body 11.

[0039] In this embodiment, a moving weight 6 is used to apply a set pressing force F to the rubber member R by each roller 4. Therefore, it is possible to make the structure for applying each set pressing force F extremely simple.

[0040] It is also possible to use other means instead of the moving weight 6, and to configure the rollers 4 to apply a set pressing force F to the rubber member R. For example, it is also possible to provide a biasing means such as a spring to each roller 4, and use the biasing force of each biasing means as the pressing force F. It is also possible to provide an actuator that moves each roller 4 toward or away from the rubber member R, and to configure the rollers 4 to apply a set pressing force F to the rubber member R. [Explanation of symbols]

[0041] 1 Manufacturing equipment 2. Transport conveyor 2a Conveyor belt 3 Support frame 4(4a, 4b, 4c, 4d, 4e) Roller 4z center axis 5 Actuators 5a Rod 6 weight 7 Base 8 spindle 9 Measuring instrument (length sensor) 10 Control Unit 11 Drum body 11a Outer surface 12 Drum shaft R Unvulcanized rubber material Ra front end Rb rear end RC annular rubber member

Claims

1. A method for manufacturing an unvulcanized rubber member, in which the length of a band-shaped unvulcanized rubber member wound on a drum body is adjusted to a target range across the width direction, a plurality of rollers are arranged in the width direction, and a pressing force of each of the rollers against the unvulcanized rubber member is set based on a comparison between measurement data across the length in the width direction and data in the target range; In a state in which the pressing force is applied to the unvulcanized rubber material by each of the rollers, the unvulcanized rubber material is wound around the drum body while each of the rollers rolls on the unvulcanized rubber material in the longitudinal direction, thereby adjusting the length to the target range across the width direction, A method for manufacturing an unvulcanized rubber member, characterized in that each roller is supported by a support shaft, a weight that moves together with a rod is provided for each roller, and by moving each rod in the rod axial direction, each roller is rotated around its respective support shaft by the weight of each weight, thereby applying the pressing force.

2. The method for manufacturing an unvulcanized rubber member according to claim 1 , wherein the length is adjusted to fall within the target range across the width direction, thereby joining the longitudinal front end and the longitudinal rear end of the unvulcanized rubber.

3. In an apparatus for manufacturing an unvulcanized rubber member, the length of a band-shaped unvulcanized rubber member wound on a drum body is adjusted to a target range across the width direction, a measuring device that measures the length across the width direction; a control unit to which data of the target range is input; a plurality of rollers arranged side by side in the width direction; a support shaft that supports each of the rollers; and a weight that moves together with a rod provided for each of the rollers, the control unit compares the measurement data across the width direction of the length measured by the measuring machine with the data of the target range, and sets the pressing forces of the rollers against the unvulcanized rubber member based on the comparison result; The rods are moved in the rod axial direction, whereby the rollers are rotated around the support shafts by the weights of the weights, thereby applying the pressing force; An apparatus for manufacturing unvulcanized rubber members, characterized in that each roller applies the pressing force to the unvulcanized rubber member while rolling longitudinally on the unvulcanized rubber member, and the unvulcanized rubber member is wound around the drum body, thereby adjusting the length to the target range across the width direction.

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