Bead filler manufacturing method

Abstract

To provide a method for joining the front and rear ends of a filler rubber on a drum.SOLUTION: The method of the embodiment comprises the steps of: holding the front portion of a filler rubber 1 placed on a table 21 with a holding device 44, advancing it, and adhering it to a predetermined position on a drum 30; and after adhering the front portion, rotating the drum 30 by a predetermined angle of less than 360°, thereby winding the filler rubber 1 onto the drum 30; stopping the drum 30 after it has rotated through the predetermined angle, and during this stop, and cutting the filler rubber 1 on the table 21 using a cutting device 20; and after the cutting, rotating the drum 30 again to wind the portion of the filler rubber 1 formed by the cutting up to the rear end thereof, thereby joining the front end and rear end of the filler rubber 1 on the drum 30.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a bead filler used in a pneumatic tire. [Background technology]

[0002] The bead filler of a pneumatic tire is annular, and its cross-sectional shape is a triangle with a height (radial length) greater than its base (inner diameter side). Such bead fillers are molded by extruding a long piece of filler rubber having a cross-section roughly the same as that of the bead filler from an extruder, cutting it to the length of one bead filler, and winding it around a drum (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6306152 Summary of the Invention [Problem to be solved by the invention]

[0004] However, filler rubber shrinks as the temperature drops, and it is difficult to control the amount of shrinkage.As a result, even if you intend to cut out a length of filler rubber that is the length of one bead filler, when you wrap the cut filler rubber around the drum, the filler rubber may not be long enough, resulting in a gap between the front and rear ends of the filler rubber, or it may be too long, resulting in a long overlap between the front and rear parts of the filler rubber.

[0005] The present invention has been made in view of the above circumstances, and has as its object to provide a method by which the front and rear ends of filler rubber can be successfully joined on a drum. [Means for solving the problem]

[0006] The present invention includes the embodiments shown below.

[0007] [1] A bead filler manufacturing method in which filler rubber placed on a table is wound onto a drum placed forward of the table to form a bead filler, the method comprising the steps of: a holding device holding a front end portion of the filler rubber on the table; a holding device moving the filler rubber forward and attaching the front end to a predetermined position on the drum; a step of the drum rotating a predetermined angle of less than 360° after attaching the front end, thereby winding the filler rubber onto the drum; a step of the drum stopping after rotating the predetermined angle, and a cutting device cutting the filler rubber on the table while the drum is stopped; and a step of the drum rotating again after the cutting, thereby cutting the portion of the filler rubber up to the rear end formed by the cutting. and winding the filler rubber up, and joining the front end and the rear end on the drum, wherein the holding of the filler rubber by the holding device includes, while the filler rubber is stopped on the table, a step in which a sensor capable of detecting the front end of the filler rubber advances together with the holding device from a position rearward of the front end, a step in which the holding device and the sensor retreat together after the sensor detects the front end of the filler rubber while advancing, and a step in which, when the sensor retreats and detects the front end of the filler rubber, the holding device and the sensor move a predetermined distance in a predetermined direction and then stop, and the holding device holds the filler rubber at that stopped position.

[0008] [2] The bead filler manufacturing method described in [1], wherein the filler rubber is extruded from a rubber extruder, and the filler rubber extruded from the extruder reaches the table without being cooled by a cooling device.

[0009] [3] A method for manufacturing a bead filler according to [1] or [2], wherein the filler rubber has a thickness and a height greater than the thickness as a length on a cross section perpendicular to its extension direction, and the height is greater than 70 mm.

[0010] [4] The bead filler manufacturing method according to any one of [1] to [3], wherein the sensor is provided forward of the holding device. [Effects of the Invention]

[0011] According to this embodiment, the front and rear ends of the filler rubber can be successfully joined on the drum. [Brief explanation of the drawings]

[0012] [Figure 1] Left view of the bead filler manufacturing equipment. [Figure 2] A diagram showing a cross section perpendicular to the extension direction of the filler rubber. (a) is a cross section of the filler rubber in an upright position. (b) is a cross section of the filler rubber lying on its side. [Figure 3] FIG. [Figure 4] 10 is an axial cross-sectional view of the drum when the filler riser member forms a cylinder. FIG. [Figure 5] FIG. 10 is an axial cross-sectional view of the drum when the filler lifting member is lifted up. [Figure 6] FIG. [Figure 7] 5A to 5C are diagrams illustrating the operation of the bead filler manufacturing device. [Figure 8] 5A to 5C are diagrams illustrating the operation of the bead filler manufacturing device. [Figure 9] 4A to 4C are diagrams illustrating the operation of the bead filler manufacturing device. [Figure 10] 4A to 4C are diagrams illustrating the operation of the bead filler manufacturing device. [Figure 11] 5A to 5C are diagrams illustrating the operation of the bead filler manufacturing device. [Figure 12] 4A to 4C are diagrams illustrating the operation of the bead filler manufacturing device. [Figure 13] 4A to 4C are diagrams illustrating the operation of the bead filler manufacturing device. [Figure 14] 4A to 4C are diagrams illustrating the operation of the bead filler manufacturing device. [Figure 15]4A to 4C are diagrams illustrating the operation of the bead filler manufacturing device. [Figure 16] 4A to 4C are diagrams illustrating the operation of the bead filler manufacturing device. [Figure 17] 4A to 4C are diagrams illustrating the operation of the bead filler manufacturing device. [Figure 18] 4A to 4C are diagrams illustrating the operation of the bead filler manufacturing device. [Figure 19] 4A to 4C are diagrams illustrating the operation of the bead filler manufacturing device. [Figure 20] 4A to 4C are diagrams illustrating the operation of the bead filler manufacturing device. [Figure 21] 4A to 4C are diagrams illustrating the operation of the bead filler manufacturing device. [Figure 22] 4A to 4C are diagrams illustrating the operation of the bead filler manufacturing device. [Figure 23] 4A to 4C are diagrams illustrating the operation of the bead filler manufacturing device. DETAILED DESCRIPTION OF THE INVENTION

[0013] The following description of the embodiments will be given with reference to the accompanying drawings. Note that the embodiments described below are merely examples, and any modifications that do not depart from the spirit of the present invention are included within the scope of the present invention.

[0014] First, we will explain the bead filler manufacturing apparatus 10 used in this embodiment. As shown in Figure 1, the bead filler manufacturing apparatus 10 of this embodiment includes an extruder 11 that extrudes filler rubber 1 forward, a festoon device 12 through which the filler rubber 1 extruded from the extruder 11 passes, a roller conveyor 13 on which the filler rubber 1 that has passed through the festoon device 12 is placed, a cutting device 20 that cuts the filler rubber 1 forward of the roller conveyor 13, a drum 30 that takes up the filler rubber 1 forward of the cutting device 20, and a transferring and attaching device 40 that transfers the front portion of the filler rubber 1 forward from the location of the cutting device 20 and attaches it to the drum 30.

[0015] In this embodiment, the side where the drum 30 is located is the front, and the side where the extruder 11 is located is the rear. Furthermore, left and right refer to the left and right when facing forward.

[0016] The extruder 11 has the same structure as a general rubber extruder. The extruder 11 kneads raw rubber and extrudes it as a long filler rubber 1.

[0017] As shown in FIG. 2, the cross-sectional shape of the filler rubber 1, i.e., the shape on a cross section perpendicular to the extension direction of the filler rubber 1, is approximately an isosceles triangle (illustrated as an accurate isosceles triangle in FIG. 2 for simplification). The height H of the filler rubber 1, i.e., the length from the base to the apex of the isosceles triangle in the direction perpendicular to the base, is, for example, longer than 70 mm. The height H of the filler rubber 1 is, for example, 90 mm or less. The thickness W of the filler rubber 1, i.e., the length of the base of the isosceles triangle, is, for example, 20.8 mm or more and 25.0 mm or less. The filler rubber 1 is extruded from the extruder 11 in a horizontal position as shown in FIG. 2(b), i.e., in a position in which the height direction is the horizontal (left-right) direction and the thickness direction is the up-down direction.

[0018] The festoon device 12 has a plurality of rollers 12a arranged in two rows, one above the other. The filler rubber 1 is wound alternately around the rollers 12a in the upper row and the rollers 12a in the lower row. The amount of filler rubber 1 held by the festoon device 12 can be adjusted by changing the vertical distance between the rollers 12a in the upper row and the rollers 12a in the lower row.

[0019] The roller conveyor 13 has a plurality of conveying rollers 13a arranged in the front-to-rear direction on a horizontal plane. Although not shown, in addition to the festoon device 12, a device for attaching a predetermined seal to the filler rubber 1 is also provided between the extruder 11 and the roller conveyor 13.

[0020] The transferring and applying device 40 includes a track 41 extending in the front-rear direction above the roller conveyor 13, an arm 42 that is long in the front-rear direction and moves in the front-rear direction along the track 41, and a servo motor 43 that serves as a moving device for moving the arm 42. By controlling the servo motor 43, the moving direction, amount of movement, and speed of the arm 42 can be controlled.

[0021] A holding device 44 capable of holding the filler rubber 1 is provided at the front end of the arm 42 as part of the transferring and applying device 40. As shown in Fig. 3, the holding device 44 includes a plurality of suction members 45 and a frame 46 to which the suction members 45 are attached. The suction members 45 may be any member capable of adsorbing the filler rubber 1, and may be, for example, one that adsorbs using the suction power of rubber or one that adsorbs using vacuum suction. The suction surfaces of the plurality of suction members 45 are on a single plane, and the suction members 45 adsorb and hold the filler rubber 1.

[0022] 3, the holding device 44 is attached to the front end of the arm 42 via an air cylinder 47, which serves as an elevating device for raising and lowering the holding device 44. In detail, a cylinder 47a of the air cylinder 47 is attached to the front end of the arm 42, and a frame 46 of the holding device 44 is attached to a rod 47b of the air cylinder 47. Therefore, the holding device 44 moves up and down as the rod 47b moves up and down.

[0023] A pressure-bonding device 48 is provided at the front end of the holding device 44 as part of the transfer and application device 40 and is used to press the filler rubber 1 onto the drum 30. As shown in Fig. 3, the pressure-bonding device 48 includes a pressure roller 49 and an air cylinder 50 as a lifting device for raising and lowering the pressure roller 49. A cylinder 50a of the air cylinder 50 is attached to the front end of the holding device 44, and the pressure roller 49 is attached to a rod 50b of the air cylinder 50. Therefore, as the rod 50b moves up and down, the pressure roller 49 moves up and down relative to the holding device 44.

[0024] A sensor 51 for detecting the filler rubber 1 is provided at the front end of the pressure-bonding device 48 as part of the transfer and application device 40. The sensor 51 is located forward of the holding device 44.

[0025] The sensor 51 is attached facing downward to the front end of the air cylinder 50 of the crimping device 48. The sensor 51 is a laser sensor that can detect when the filler rubber 1 is directly below it, which is the detection direction. When the sensor 51 moves and no longer detects the filler rubber 1 that it had been detecting previously, or when it begins to detect the filler rubber 1 that it had not been detecting previously, it can be assumed that the sensor 51 has detected the end of the filler rubber 1.

[0026] As the arm 42 moves, the holding device 44, the crimping device 48, and the sensor 51 move together in the forward and backward directions. By controlling the servo motor 43, the movement direction, amount, and speed of the arm 42 can be controlled, and the movement direction, amount, and speed of the holding device 44, the crimping device 48, and the sensor 51 attached to the arm 42 can be controlled.

[0027] As shown in FIG. 1, a table 21 is provided in front of the roller conveyor 13 as part of the bead filler manufacturing apparatus 10. The table 21 is provided in a form that extends forward from the front end of the roller conveyor 13. The upper surface of the table 21 is a horizontal plane that coincides with the upper surface of the roller conveyor 13. The upper surface of the table 21 is subjected to a tag-free treatment to give it a matte finish. The surface of the filler rubber 1 is smooth and reflects light, but the matte finish of the upper surface of the table 21 makes it less likely to reflect light, making it easier for the sensor 51 to detect the presence or absence of filler rubber 1 on the table 21.

[0028] The cutting device 20 is provided above the table 21. The cutting device 20 includes a blade 22 that cuts the filler rubber 1 and a drive device 23 that holds and moves the blade 22. When the drive device 23 is driven, the blade 22 retreats to an upper standby position or advances onto the table 21 to cut the filler rubber 1. The blade 22 advances diagonally forward toward the table 21 and cuts the filler rubber 1 at an angle relative to the top surface of the table 21.

[0029] The drum 30 has a general structure as a drum for molding the bead portions of pneumatic tires. The drum 30 rotates counterclockwise in FIG. 1 around a horizontal rotation axis. As shown in FIGS. 4 and 5, the drum 30 has a cylindrical main body 31 and a bead core holding portion 32 provided adjacent to the main body 31 at one axial position of the main body 31. The surface of the main body 31 is formed by a plurality of plate-shaped filler riser members 33 arranged cylindrically (see FIG. 4). These filler riser members 33 can rise 90° as shown in FIG. 5, with the end of the main body 31 on the bead core holding portion 32 side as an axis.

[0030] As shown by the two-dot chain line in Fig. 4, the filler rubber 1 is wound in a horizontal state around the filler raising member 33 on the main body 31. Thereafter, the filler rubber 1 is raised by the filler raising member 33 as shown by the two-dot chain line in Fig. 5.

[0031] The diameter of the drum 30 is, for example, 19.5 inches, 22.5 inches, or 24.5 inches. Therefore, the length of one piece of filler rubber 1 wound around the drum 30 is, for example, 1587 mm or more and 2053 mm or less.

[0032] As shown in FIG. 1, a gripping device 14 that grips the filler rubber 1 by sandwiching it from above and below is provided between the cutting device 20 and the drum 30 as part of the bead filler manufacturing device 10.

[0033] A control device 52 consisting of a computer is also provided as part of the bead filler manufacturing apparatus 10. As shown in Fig. 6, the control device 52 is connected to the servo motor 43 that moves the arm 42, air control devices 53 and 54 that operate the air cylinders 47 and 50, a sensor 51, the drive device 23 in the cutting device 20, a servo motor 55 that rotates the drum 30, and the like. The control device 52 controls the connected devices, etc. Based on the control by the control device 52, the forward and backward movement of the holding device 44, cutting by the cutting device 20, rotation of the drum 30, etc. are performed.

[0034] The bead filler manufacturing apparatus 10 of this embodiment is not provided with a cooling device (for example, a water cooling device using a chiller or an air cooling device such as a blower) for cooling the filler rubber 1.

[0035] A bead filler manufacturing method using such a bead filler manufacturing apparatus 10 will be described.

[0036] In summary, the filler rubber 1 extruded from the extruder 11 passes through the festoon device 12 and is placed on the roller conveyor 13, then moves further forward and is wound around the drum 30. At a predetermined timing, the filler rubber 1 is cut by the cutting device 20, and the entire cut-out portion is wound around the drum 30 and molded into a bead filler. After being extruded from the extruder 11, the filler rubber 1 is molded into a bead filler on the drum 30 without being cooled by a cooling device. Furthermore, the filler rubber 1 remains in a horizontal position from the time it is extruded from the extruder 11 until it is wound around the drum 30.

[0037] The bead filler manufacturing method will be described in detail with reference to FIGS.

[0038] As a premise for the explanation, it is assumed that the beginning portion of the filler rubber 1 extruded from the extruder 11 has already been cut forward from the table 21 by the cutting device 20, and has been molded into the first bead filler on the drum 30. FIG. 7 shows the state when the first cut filler rubber 1 has been molded into the first bead filler on the drum 30, and the filler rubber 1 remaining on the table 21 and roller conveyor 13 after cutting has stopped and is waiting. At this time, the holding device 44, the crimping device 48, and the sensor 51 are in waiting positions behind the front end 1a of the filler rubber 1 so as not to interfere with the cutting of the filler rubber 1 by the cutting device 20. It is also assumed that the first bead filler has been removed from the drum 30.

[0039] While the filler rubber 1 is stopped on the table 21 and the roller conveyor 13 in this manner, a step is performed in which the holding device 44 holds the front part of the filler rubber 1. At the time when the holding device 44 holds the filler rubber 1, the average temperature of the part of the filler rubber 1 that is about to be cut out (mainly the part on the table 21 and the roller conveyor 13) is 30°C or higher, and although it depends on the time that has passed before being held, it is, for example, between 50°C and 80°C.

[0040] As a step for the holding device 44 to hold the front portion of the filler rubber 1, first, the holding device 44, the crimping device 48, and the sensor 51 move forward together at a constant speed, as shown by the arrow in Figure 8. Then, the sensor 51 passes over the front end 1a of the filler rubber 1 on the table 21, and stops detecting the filler rubber 1 that it had been detecting up until then. When the sensor 51 moves forward and no longer detects the filler rubber 1 that it had been detecting up until then, this is equivalent to the sensor 51 detecting the front end 1a of the filler rubber 1.

[0041] When the sensor 51 detects the front end 1a of the filler rubber 1, the control device 52 controls the servo motor 43 to stop. However, it takes some time for the holding device 44, the crimping device 48, and the sensor 51 to completely stop after the control device 52 issues a command to stop the servo motor 43. The reason it takes some time for the servo motor 43 to completely stop is that the servo motor 43 cannot be stopped suddenly, and the holding device 44 and other components have moved a relatively long distance, which causes inertia and slippage. Therefore, as shown in Figure 8, the sensor 51 stops at a position further forward than the front end 1a of the filler rubber 1, and the holding device 44 is not in a position where it should hold the filler rubber 1.

[0042] After the holding device 44, the crimping device 48, and the sensor 51 have stopped, the holding device 44, the crimping device 48, and the sensor 51 move backward together as shown by the arrows in Fig. 9. The speed (speed) of the backward movement may be the same as the speed (speed) of the forward movement, or may be slower than the forward movement.

[0043] Then, the sensor 51, while retracting, detects the filler rubber 1 that it had not detected before. This is equivalent to the sensor 51 again detecting the front end 1a of the filler rubber 1. Note that the distance that the sensor 51 and other sensors move backward from when it starts to move backward until it detects the front end 1a of the filler rubber 1 is shorter than the distance that the sensor 51, which is in the standby position, moves forward from when it starts to move forward until it detects the front end 1a of the filler rubber 1.

[0044] When the sensor 51 detects the front end 1a of the filler rubber 1 again, the movement of the holding device 44, the crimping device 48, and the sensor 51 temporarily stops (FIG. 9). Next, the holding device 44, the crimping device 48, and the sensor 51 move a predetermined distance in a predetermined direction as shown by the arrows in FIG. 10, and then stop. At this time, the stop after moving a predetermined distance in a predetermined direction is incremental positioning. As a result, the holding device 44 stops at a portion a predetermined distance from the front end 1a of the filler rubber 1.

[0045] Next, as shown by the arrow in Fig. 11, the holding device 44 descends, and the suction member 45 (see Fig. 3) of the holding device 44 adsorbs to the front part of the filler rubber 1. As a result, the holding device 44 holds a portion of the filler rubber 1 at a predetermined distance from the front end 1a.

[0046] After the holding device 44 holds the front portion of the filler rubber 1 in this manner, the holding device 44 attaches the front portion of the filler rubber 1 to a predetermined position on the drum 30. In detail, the holding device 44 rises as shown by the arrow in Fig. 12 to lift the front portion of the filler rubber 1, and as shown by the arrow in Fig. 13, the holding device 44 advances to above the predetermined position on the drum 30 while holding the front portion of the filler rubber 1, thereby advancing the filler rubber 1, and as shown by the arrow in Fig. 14, the holding device 44 descends as shown by the arrow in Fig. 14 to attach at least a part of the front portion of the filler rubber 1 to the predetermined position on the drum 30. Here, the predetermined position on the drum 30 is a predetermined position on the outer peripheral surface of the drum 30, and in the case of Fig. 14, it is a position slightly behind the top (highest part) of the drum 30.

[0047] Next, the adsorption member 45 of the holding device 44 releases the filler rubber 1, and the holding device 44 rises. Next, the drum 30 starts to rotate in the direction to take up the filler rubber 1. Almost simultaneously with the drum 30 starting to rotate, the pressure roller 49 of the pressure bonding device 48 descends as shown by the arrow in Figure 15, and presses the filler rubber 1 toward the outer peripheral surface of the drum 30. The pressure roller 49 continues to press the filler rubber 1 toward the outer peripheral surface of the drum 30 at the same position while the drum 30 is rotating.

[0048] The drum 30 rotates as shown by the arrow in Fig. 16, thereby winding up the filler rubber 1. As the front portion of the filler rubber 1 is wound onto the drum 30, the filler rubber 1 moves forward on the table 21 and the roller conveyor 13 as shown by the arrow in Fig. 16.

[0049] The drum 30 stops once it has rotated a predetermined angle. The predetermined angle here is an angle less than 360°, for example, between 270° and 300°. Figure 17 shows an example of the state when the drum 30 has stopped, and the rotation angle up to this point is approximately 270°.

[0050] When the rotation of the drum 30 stops, first, the pressure roller 49 rises as shown by the arrow in Figure 18 and moves away from the filler rubber 1. Next, the holding device 44, the pressure device 48, and the sensor 51 move backward as shown by the arrow in Figure 19 and return to their standby positions.

[0051] Next, as shown in Fig. 20, the gripping device 14 holds the filler rubber 1 between the table 21 of the cutting device 20 and the drum 30. Next, the blade 22 of the cutting device 20 advances onto the table 21 as shown by the arrow in Fig. 20 and cuts the filler rubber 1. The cutting position is set so that by cutting the filler rubber 1 at that position, the filler rubber 1 for one bead filler (i.e., one revolution of the drum 30) can be cut forward.

[0052] By this cutting, the portion of the filler rubber 1 forward of the cutting position is cut out as the filler rubber 1 for one bead filler. Furthermore, of the cut portion of the filler rubber 1, the portion forward of the blade 22 becomes the rear end 1b of the filler rubber 1 on the drum 30 side (see Figure 21), and the portion behind the blade 22 becomes the front end 1a of the filler rubber 1 on the roller conveyor 13 side (see Figure 21). The gripping device 14 holds the filler rubber 1 on the drum 30 side even after cutting. After cutting, the portion of the filler rubber 1 rearward of the cutting position (i.e., on the roller conveyor 13 side) waits in the position at the time of cutting without moving.

[0053] After the filler rubber 1 is cut, the drum 30 resumes rotation. As the drum 30 rotates, the cut-out portion of the filler rubber 1 up to the rear end 1b is wound onto the drum 30. As shown in FIG. 21 , the gripping device 14 continues to hold the filler rubber 1 during this winding.

[0054] As the drum 30 rotates, the filler rubber 1 is wound up to its rear end 1b onto the drum 30, and as shown in Figure 22, the front end 1a and rear end 1b of the filler rubber 1 are aligned on the drum 30 and joined together. As a result, the filler rubber 1 lying on its side is wound around the main body 31 of the drum 30 for one full revolution. The gripping device 14 releases the filler rubber 1 when the rear end 1b of the filler rubber 1 is attached to the drum 30.

[0055] Next, as shown in Figures 23 and 5, all of the filler raising members 33 rise up on the drum 30, causing the horizontally laid filler rubber 1 to rise (i.e., the height direction of the filler rubber 1 becomes the radial direction of the drum 30), and the bead filler is completed.

[0056] Before the filler rubber 1 is raised, the bead core 2 is held in the bead core holding portion 32 of the drum 30 as shown in Fig. 4. Then, as the filler rubber 1 is raised, the bottom surface of the filler rubber 1 (the surface corresponding to the base of an isosceles triangle in cross section) adheres to the bead core 2 as shown in Fig. 5. This completes the bead portion consisting of the bead core 2 and the bead filler.

[0057] The completed bead portion is removed from the drum 30 and cooled in a location separate from the bead filler manufacturing apparatus 10. Measures are taken to prevent deformation of the bead portion during cooling, for example, measures are taken to position the bead filler so that one entire surface (side surface) is in contact with a flat surface.

[0058] After the bead portion has been removed from the drum 30 as described above, the winding of the filler rubber 1, which has been waiting on the table 21 and roller conveyor 13, onto the drum 30 is resumed. To this end, the holding device 44 holds the front portion of the filler rubber 1 on the table 21 in the same manner as described above.

[0059] Here, the filler rubber 1 is extruded from the extruder 11 and reaches the table 21 without being cooled by a cooling device, so it is hot when it reaches the table 21. However, between the time the filler rubber 1 is cut in the cutting device 20 and the time the holding device 44 comes to hold the front part of the filler rubber 1 remaining on the table 21 after cutting, time passes and the filler rubber 1 cools and shrinks in the front-to-rear direction. Therefore, the position of the front end 1a of the filler rubber 1 changes between the time the filler rubber 1 is cut and the time the holding device 44 comes to hold the front part of the filler rubber 1. However, by using the above-described method using the sensor 51, the holding device 44 can hold a portion of the filler rubber 1 a certain distance from the front end 1a.

[0060] The steps after the holding device 44 holds the front portion of the filler rubber 1 are the same as those described above. In this way, the steps from when the holding device 44 holds the front portion of the filler rubber 1 placed on the table 21 to when the bead portion is completed on the drum 30 and removed from the drum 30 are repeated.

[0061] As described above, the method of this embodiment includes the steps of: holding the front part of the filler rubber 1 placed on the table 21 with the holding device 44 and moving it forward to attach it to a predetermined position on the drum 30; rotating the drum 30 a predetermined angle less than 360° after attaching the front part of the filler rubber 1 to the drum 30, thereby winding the filler rubber 1 onto the drum 30; stopping the drum 30 after rotating the predetermined angle, and while it is stopped, the cutting device 20 cuts the filler rubber 1 on the table 21; and rotating the drum 30 again after cutting the filler rubber 1, thereby winding up the portion of the filler rubber 1 formed by the cut up to the rear end 1b, and joining the front end 1a and rear end 1b of the filler rubber 1 on the drum 30.

[0062] In this method, if the holding device 44 can hold a portion of the filler rubber 1 a predetermined distance from the front end 1a on the table 21, the holding device 44 can attach the held portion of the filler rubber 1 to a predetermined position on the drum 30, thereby making it possible to set the position of the front end 1a of the filler rubber 1 on the drum 30 to a predetermined position. This determines the length of filler rubber 1 that will be wound up by the time the drum 30 rotates the predetermined angle and stops. Furthermore, because the distance from the cutting position by the cutting device 20 to the drum 30 is fixed, the length of filler rubber 1 that the drum 30 will wind up after cutting the filler rubber 1 is also determined. For these reasons, if the holding device 44 can hold a portion of the filler rubber 1 a predetermined distance from the front end 1a, a predetermined length of filler rubber 1 can be wound onto the drum 30, and the front end 1a and rear end 1b of the filler rubber 1 can be aligned and joined on the drum 30.

[0063] In this embodiment, the holding of the front portion of the filler rubber 1 by the holding device 44 includes the following steps while the filler rubber 1 is stopped on the table 21: the sensor 51 moves forward together with the holding device 44 from a position behind the front end 1a of the filler rubber 1; after the sensor 51 no longer detects the filler rubber 1 while advancing, the holding device 44 and the sensor 51 move backward together; and when the sensor 51 detects the filler rubber 1 while retreating, the holding device 44 and the sensor 51 move a predetermined distance in a predetermined direction and then stop, and the holding device 44 holds the filler rubber 1 at that stopped position.

[0064] Here, the initial forward movement causes the holding device 44 to move too far forward from the position where it should hold the filler rubber 1, but the subsequent steps of retreating and moving allow the holding device 44 to stop at the position where it should hold the filler rubber 1. As a result, the holding device 44 can hold a portion of the filler rubber 1 a set distance from the front end 1a. As a result, the front end 1a and rear end 1b of the filler rubber 1 can be aligned and joined on the drum.

[0065] Furthermore, the bead filler manufacturing apparatus 10 repeatedly manufactures bead fillers, but no matter how many times the filler rubber 1 is held by the holding device 44, the holding device 44 can hold a portion of the filler rubber 1 at a fixed distance from the front end 1a. Therefore, the front end 1a and rear end 1b of the filler rubber 1 can be aligned and joined on the drum every time.

[0066] As described above, the sensor 51 and the holding device 44 move forward and then backward before the holding device 44 holds the filler rubber 1. If the forward speed at this time is increased, the cycle time until the holding device 44 holds the filler rubber 1 can be shortened. Also, if the backward speed is slower than the forward speed, the sensor 51 and the holding device 44 can immediately move on to the next movement when the sensor 51 detects the front end 1a of the filler rubber 1 during the backward movement.

[0067] In addition, filler rubber generally tends to curl when cooled because its thinner apex side (the apex side of the isosceles triangle in cross section) shrinks more easily in the longitudinal direction than its thicker base side (the base side of the isosceles triangle in cross section). Therefore, if the filler rubber is cooled in a cooling device before being wound around the drum, the filler rubber will curl, making it difficult to align the front end 1a and rear end 1b of the filler rubber on the drum, or even if they are aligned, they may fall over after being raised. When the filler rubber is tall (for example, if it is taller than 70 mm), the curling of the filler rubber is particularly likely to occur, making these problems more likely.

[0068] However, the filler rubber 1 of this embodiment does not undergo cooling by a cooling device from the time it is extruded from the extruder 11 until it is wound around the drum 30. Therefore, the filler rubber 1 does not curl significantly, and the front end 1a and rear end 1b of the filler rubber 1 can be successfully joined on the drum.

[0069] Here, the filler rubber 1 extruded from the extruder 11 reaches the table 21 without being cooled by a cooling device, so it cools somewhat on the table 21 and shrinks in the front-to-back direction. Since it is difficult to control the amount of shrinkage, it is also difficult to control the position of the front end 1a of the filler rubber 1 on the table 21. However, even in such a case, according to this embodiment, the holding device 44 can hold a portion of the filler rubber 1 a predetermined distance from the front end 1a.

[0070] Furthermore, because the sensor 51 is provided forward of the holding device 44, the operation of the holding device 44 to hold the front portion of the filler rubber 1 is performed efficiently. In detail, when the sensor 51 and the holding device 44, which are in a standby position behind the front end 1a of the filler rubber 1, move forward, the sensor 51 detects the front end 1a of the filler rubber 1 before the holding device 44 reaches the front end 1a of the filler rubber 1 (see FIG. 8). The sensor 51 and the holding device 44 then move backward, and the sensor 51 detects the front end 1a of the filler rubber 1 during the backward movement. At the time of detection, the holding device 44 is above the filler rubber 1 (see FIG. 9). The holding device 44 then holds the filler rubber 1. Because the sensor 51 and the holding device 44 move in this manner, the movement distance of the sensor 51 and the holding device 44 in the front-to-rear direction is shorter than when the sensor 51 is provided behind the holding device 44, and the cycle time for the holding device 44 to hold the front portion of the filler rubber 1 is shortened.

[0071] Conversely, if the sensor 51 is provided behind the holding device 44, the holding device 44 must move forward to a position forward of the front end 1a of the filler rubber 1 in order for the sensor 51 to move forward and detect the front end 1a of the filler rubber 1, and when the sensor 51 moves backward to detect the front end 1a of the filler rubber 1, the holding device 44 is still forward of the front end 1a of the filler rubber 1, and then the holding device 44 must move further backward. Therefore, the movement distance of the holding device 44 in the front-to-rear direction becomes longer than in this embodiment, resulting in a longer cycle time.

[0072] Furthermore, in this embodiment, the servo motor 43 is used to move the arm 42 to which the holding device 44 and the sensor 51 are attached, so that the movements of the holding device 44 and the sensor 51 can be accurately controlled.

[0073] Various modifications can be made to the above embodiment.

[0074] For example, in the above embodiment, the sensor 51 can detect the presence of the filler rubber 1 on the table 21, and the position where the moving sensor 51 starts to detect the filler rubber 1 and the position where it stops detecting the filler rubber 1 are detected as the front end 1a of the filler rubber 1. Instead of such a sensor 51, a sensor that can directly recognize and detect the front end 1a of the filler rubber 1 may be used.

[0075] Furthermore, there may be cases where the table 21 is extremely short in the front-to-rear direction, and the holding device 44 holds the portion of the filler rubber 1 behind the table 21. In that case, the portion adjacent to the rear of the table 21, on which the filler rubber 1 rests (in the above embodiment, the portion in front of the roller conveyor 13), is also considered to be part of the table. [Explanation of symbols]

[0076] 1...filler rubber, 1a...front end, 1b...rear end, 2...bead core, 10...bead filler manufacturing device, 11...extruder, 12...festoon device, 13...roller conveyor, 13a...conveying roller, 14...gripping device, 20...cutting device, 21...table, 22...blade, 23...driving device, 30...drum, 31...main body, 32...bead core holding part, 33...filler raising member, 40...transfer and pasting device, 41...track, 42...arm, 43...servo motor, 44...holding device, 45...suction member, 46...frame, 47...air cylinder, 47a...cylinder, 47b...rod, 48...pressing device, 49...pressing roller, 50...air cylinder, 50a...cylinder, 50b...rod, 51...sensor, 52...controller, 53...air control device, 54...air control device, 55...servo motor

Claims

1. A bead filler manufacturing method in which filler rubber arranged on a table is wound around a drum arranged forward of the table to form a bead filler, a step of holding a front end portion of the filler rubber on the table by a holding device; The holding device advances the filler rubber and attaches the front end to a predetermined position on the drum; a step of rotating the drum by a predetermined angle less than 360° after attaching the front end, thereby winding the filler rubber onto the drum; the drum stops after rotating by the predetermined angle, and a cutting device cuts the filler rubber on the table while the drum is stopped; After the cutting, the drum is rotated again to wind up the portion of the filler rubber formed by the cutting up to the rear end, and the front end and the rear end are joined on the drum. Including, The holding of the filler rubber by the holding device is performed by: As a step while the filler rubber is stopped on the table, a step in which a sensor capable of detecting the front end of the filler rubber advances together with the holding device from a position rearward of the front end; a step in which the holding device and the sensor move backward together after the sensor detects the front end of the filler rubber during the forward movement; When the sensor detects the front end of the filler rubber during the retreat, the holding device and the sensor move a predetermined distance in a predetermined direction and then stop, and the holding device holds the filler rubber at that stopped position; A method for manufacturing a bead filler, comprising:

2. The filler rubber is extruded from a rubber extruder; 2. The bead filler manufacturing method according to claim 1, wherein the filler rubber extruded from the extruder reaches the table without being cooled by a cooling device.

3. 3. The bead filler manufacturing method according to claim 1, wherein the filler rubber has a thickness and a height greater than the thickness as a length on a cross section perpendicular to its extension direction, and the height is greater than 70 mm.

4. 3. The bead filler manufacturing method according to claim 1, wherein the sensor is provided forward of the holding device.

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