Cylindrical member forming device and conveyor belt slippage detection device

Abstract

To provide a cylindrical member molding device 2 that can contribute to stable production of a high-quality tire.SOLUTION: A molding device 2 comprises: an extrusion unit 4; a molding unit 6; a conveying unit 8; and a control unit 10. The conveying unit 8 includes a festoon 28, a loading section 24, and an unloading section 26. The loading section 24 includes a loading roller 58 that rotates in synchronism with the extrusion unit 4 and drives a conveyor belt 20. The unloading section 26 includes an unloading roller 68 that rotates in synchronism with the molding unit 6 and drives the conveying belt 20. The festoon 28 includes measuring means 50 for measuring an amount of a strip S existing on the festoon 28. The control unit 10 determines whether or not the conveying belt 20 is slipping based on an amount of the strip S unloaded by the unloading roller 68, an amount of the strip S loaded by the loading roller 58, and an amount of the strip S existing on the festoon 28.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a forming device for a tubular member and a slippage detection device for a conveyor belt. [Background technology]

[0002] For example, a tire is obtained by vulcanizing a raw tire (a tire in an unvulcanized state, also called a raw cover) in a mold. A tire is formed by combining rubber members such as a tread and a sidewall. A strip winding method is known as a method for forming the rubber members (for example, Patent Document 1 below). In the strip winding method, an extruder forms a band-shaped strip of unvulcanized rubber, and a molding machine winds the strip spirally to form a tubular rubber member (hereinafter also referred to as a tubular member) having a desired cross-sectional shape.

[0003] The speed at which the strip is formed in the extruder is slower than the speed at which the strip is wound in the molding machine. As in the lamination device disclosed in the following Patent Document 1, an accumulator unit (also called a festoon) for stocking the strip is provided between the extruder and the molding machine, and a tubular member is formed after a predetermined amount of the strip is stocked in the festoon. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2007-136740 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the strip winding method, the strip is transported on a conveyor belt. The conveyor belt between the festoon and the former is driven by rollers. The strip stocked in the festoon is transported to the former by the conveyor belt driven by rollers, and placed on the drum of the former.

[0006] The strip is soft. If excessive tension is applied to the strip when it is placed on the drum, the strip may be deformed. To prevent deformation of the strip, the rotation speed of the roller is controlled so that the speed at which the strip is fed by the conveyor belt is equal to the speed at which the strip is wound on the drum.

[0007] The conveyor belt gradually hardens with use. A hard conveyor belt is more likely to slip on the rollers. The mass of the tubular member is controlled by the speed and driving time of the rollers. If the conveyor belt slips on the rollers, a tubular member that is lighter than expected is formed. In this case, there is a risk of forming a low-quality tire that does not perform as expected at the time of design. For manufactured tires, product inspections such as radial force variation (RFV) are performed. Low-quality tires are selected and discarded during this inspection. Discarding tires increases production costs. If equipment that can monitor the speed of the conveyor belt is installed, it is possible to detect slippage of the conveyor belt. However, installing such equipment incurs costs. There is a need to establish technology that can detect slippage of the conveyor belt using the functions of existing equipment, rather than installing new dedicated equipment.

[0008] The present invention has been made in view of the above circumstances, and has an object to provide a tubular member forming apparatus and a conveyor belt slippage detection device that can contribute to the stable production of high-quality tires. [Means for solving the problem]

[0009] A molding device for a tubular member according to one aspect of the present invention includes an extrusion unit that forms a belt-shaped strip made of unvulcanized rubber, a molding unit that spirally winds the strip to form a tubular member, a transport unit that is located between the extrusion unit and the molding unit and transports the strip on a transport belt, and a control unit that controls the operation of the extrusion unit, the molding unit, and the transport unit. The transport unit includes a festoon that stocks the strip, an input section that sends the strip to the festoon, and an output section that sends the strip to the molding unit. The input section includes an input roller that rotates in synchronization with the extrusion unit and drives the transport belt. The output section includes an output roller that rotates in synchronization with the molding unit and drives the transport belt. The festoon includes a measuring means that measures the amount of the strip present in the festoon. The control unit determines whether or not the conveying belt is slipping based on the amount of the strip discharged by the discharge roller, calculated using the speed and drive time of the discharge roller, the amount of the strip fed into the feed roller, calculated using the speed and drive time of the feed roller, and the amount of the strip present in the festoon.

[0010] Preferably, in this tubular member forming apparatus, the control unit determines whether or not the conveyor belt is slipping by comparing a stock amount of the strip at the start of formation of the tubular member, which is obtained based on the outgoing amount of the strip and the incoming amount of the strip, with an amount of change of the strip in the festoon, which is obtained based on the amount of the strip present in the festoon. The stock amount of the strip at the start of formation of the tubular member is represented by the difference between the outgoing amount of the strip and the incoming amount of the strip between the start and end of formation of the tubular member. The amount of change of the strip in the festoon is represented by the difference between the amount of the strip present in the festoon at the start of formation of the tubular member and the amount of the strip present in the festoon at the end of formation of the tubular member.

[0011] Preferably, in this tubular member forming apparatus, the festoon comprises a reference member and a movable member arranged vertically in line with the reference member and supported so as to be movable vertically. The reference member comprises a reference frame and a plurality of pulleys attached to the reference frame and arranged at equal intervals in the length direction. The movable member comprises a movable frame and a plurality of pulleys attached to the movable frame and arranged at equal intervals in the length direction. The conveyor belt is alternately hung between the pulleys of the reference member and the pulleys of the movable member. The amount of the strip present in the festoon is obtained based on the distance from the reference member to the movable member.

[0012] A slippage detection device for a conveyor belt according to one aspect of the present invention is a slippage detection device for a conveyor belt in a conveying unit that places a belt-shaped strip made of unvulcanized rubber formed by an extrusion unit on the conveyor belt, conveys the strip to a molding unit that spirally winds the strip to form a tubular member, and has a festoon for stocking the strip. The slippage detection device includes an input roller that sends the strip to the festoon, an output roller that sends the strip to the molding unit, a measuring means for measuring the amount of the strip present in the festoon, and a control unit that controls the operation of the input roller and the output roller. The input roller rotates in synchronization with the extrusion unit to drive the conveyor belt. The output roller rotates in synchronization with the molding unit to drive the conveyor belt. The control unit determines whether or not the conveying belt is slipping based on the amount of the strip discharged by the discharge roller, calculated using the speed and drive time of the discharge roller, the amount of the strip fed into the feed roller, calculated using the speed and drive time of the feed roller, and the amount of the strip present in the festoon. Effect of the Invention

[0013] According to the present invention, it is possible to obtain a tubular member forming device and a conveyor belt slippage detection device which can contribute to the stable production of high-quality tires. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic diagram showing an example of a molding apparatus for a tubular member according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic diagram showing an overview of the measuring means provided in the festoon. [Diagram 3] FIG. 3 is a schematic diagram illustrating the operation of the measuring means. [Figure 4] FIG. 4 is a conceptual diagram showing an example of the control unit. [Diagram 5] FIG. 5 is a schematic diagram showing the forming apparatus before starting to form the tubular member. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, the present invention will be described in detail based on preferred embodiments with reference to the drawings as appropriate.

[0016] FIG 1 shows a molding apparatus 2 according to one embodiment of the present invention. The molding apparatus 2 forms a tubular member C using a belt-shaped strip S made of unvulcanized rubber. In the molding apparatus 2, rubber members such as a tire tread and sidewalls are formed as the tubular member C. The molding apparatus 2 is used for manufacturing tires. The molding apparatus 2 forms a part of a tire manufacturing apparatus.

[0017] In FIG. 1, the up-down direction is the height direction of the forming device 2. The upper side of the paper is the upper side of the forming device 2, and the lower side of the paper is the lower side of the forming device 2. The left-right direction is the length direction of the forming device 2. The strip S moves from the left side to the right side of the paper. The left side of the paper is the upstream side of the forming device 2, and the right side of the paper is the downstream side of the forming device 2. The direction perpendicular to the paper is the width direction of the forming device 2.

[0018] The molding device 2 includes an extrusion unit 4, a molding unit 6, a conveying unit 8, and a control unit 10.

[0019] The extrusion unit 4 forms a strip S. The extrusion unit 4 includes an extruder 12 and a calender roll 14. In the extruder 12, unvulcanized rubber is processed into a strip shape. The strip-shaped unvulcanized rubber passes through the calender roll 14. This adjusts the shape of the unvulcanized rubber, and a strip S having a predetermined shape is obtained.

[0020] The forming unit 6 spirally winds the strip S to form a tubular member C. The forming unit 6 includes a drum 16 and an application roller 18. The drum 16 is rotatably supported by a main body frame (not shown) of the molding unit 6. Although not described in detail, the drum 16 has an expansion / contraction function, and can expand or contract its diameter depending on the situation. The drum 16 is rotated by a driving means (not shown) such as an electric motor. A strip S is conveyed to the forming unit 6 from an upstream conveying unit 8. The strip S conveyed from the upstream side is wound around a drum 16. An application roller 18 presses the strip S against the drum 16 or another cylindrical member formed on the drum 16. As a result, the strip S is applied to the drum 16 or another cylindrical member. The drum 16 is rotated, and the strip S is spirally wound while controlling the application position of the strip S, thereby forming a cylindrical member C having a desired shape.

[0021] The conveying unit 8 is located between the extrusion unit 4 and the molding unit 6. The conveying unit 8 conveys the strip S on a conveying belt 20. The conveying belt 20 is inextensible, and the strip S is in close contact with one surface of the conveying belt 20. In this way, the strip S is held by the conveying belt 20. The transport unit 8 includes a festoon section 22, an input section 24, and an output section 26.

[0022] The festoon section 22 stocks the conveyor belt 20. The festoon section 22 of this molding device 2 is composed of two festoons 28. Specifically, the festoon section 22 includes a first half festoon 28F used to stock the conveyor belt 20 heading from the extrusion unit 4 to the molding unit 6, and a second half festoon 28S used to stock the conveyor belt 20 heading from the molding unit 6 to the extrusion unit 4. The strip S is placed on the conveyor belt 20 heading from the extrusion unit 4 to the molding unit 6. In this molding device 2, the first half festoon 28F stocks the strip S. The transport unit 8 includes a festoon 28 that stocks the strip S. In this forming apparatus 2, the first half festoon 28F is located on the upper side, and the second half festoon 28S is located on the lower side. The first half festoon 28F may be disposed on the lower side, and the second half festoon 28S may be disposed on the upper side. The first half festoon 28F and the second half festoon 28S may be disposed side by side.

[0023] The festoon 28 includes a reference member 30 and a moving member 32. The reference member 30 and the moving member 32 are rod-shaped members extending in the longitudinal direction of the forming apparatus 2. The moving member 32 is arranged vertically next to the reference member 30. The moving member 32 is arranged parallel to the reference member 30.

[0024] The reference member 30 includes a reference frame 34 and a plurality of pulleys 36 arranged in a horizontal line. The plurality of pulleys 36 are attached to the reference frame 34 and arranged at equal intervals in the longitudinal direction of the reference frame 34. The moving member 32 includes a moving frame 38 and a plurality of pulleys 40 arranged in a horizontal line. The plurality of pulleys 40 are attached to the moving frame 38 and arranged at equal intervals in the longitudinal direction of the moving frame 38.

[0025] In the longitudinal direction of the forming apparatus 2, a pulley 40 in the moving member 32 is disposed between one pulley 36 in the reference member 30 and another pulley 36 located adjacent to the one pulley 36. The conveyor belt 20 is alternately wound around the pulleys 36 in the reference member 30 and the pulleys 40 in the moving member 32.

[0026] In this molding apparatus 2, the reference member 30 and the movable member 32 are supported by a support member 42. The support member 42 includes a pair of support frames 44 and a pair of guide shafts 46. The pair of support frames 44 are arranged at a distance in the longitudinal direction of the molding apparatus 2. Each support frame 44 extends in the vertical direction. The pair of guide shafts 46 are located between the pair of support frames 44. The pair of guide shafts 46 are arranged at a distance in the longitudinal direction. Each guide shaft 46 extends in the vertical direction. In this forming apparatus 2, the support frame 44 of the first festoon 28F and the support frame 44 of the second festoon 28S are configured by a single frame extending upward from the floor surface on which the forming apparatus 2 is placed.

[0027] In this forming apparatus 2, the reference frame 34 of the reference member 30 is fixed to a support frame 44. The reference member 30 spans the pair of support frames 44. The upper end of the guide shaft 46 is fixed to the reference frame 34. The guide shaft 46 extends downward from the reference frame 34. The lower end of the guide shaft 46 is fixed to the support frame 44 via a connecting frame 48. The movable member 32 is positioned below the reference member 30. A pair of through holes (not shown) extending vertically is provided in a moving frame 38 of the movable member 32. A guide shaft 46 passes through each through hole. The movable member 32 is movable up and down. The movable member 32 can move up and down while maintaining a parallel relationship with the reference member 30.

[0028] The moving member 32 tries to move downward due to its own weight. As described above, the conveyor belt 20 is alternately hung on the pulley 36 of the reference member 30 and the pulley 40 of the moving member 32. When the amount of conveyor belt 20 present in the festoon 28 is large, the moving member 32 descends due to its own weight. When the amount of conveyor belt 20 is small, the moving member 32 is pulled upward by the conveyor belt 20. The moving member 32 is arranged vertically alongside the reference member 30 and is supported so as to be vertically movable.

[0029] In the festoon 28, the conveyor belt 20 extends in a zigzag shape while alternately turning back between the reference member 30 and the moving member 32. The conveyor belt 20 in the festoon 28 is configured with a plurality of turning units. The length of one turning unit can be grasped from the distance between the reference member 30 and the moving member 32. The actual length of the conveyor belt 20 present in the festoon 28 can be obtained by considering the number of turning units. The conveyor belt 20 carrying the strips S is stocked in the first half festoon 28F. The amount of the strips S present in the first half festoon 28F can be obtained by measuring the distance between the reference member 30 and the moving member 32.

[0030] The festoon 28 is provided with a measuring means 50 that measures the amount of the strip S present in the festoon 28. In this forming apparatus 2, there is no particular limitation on the configuration of the measuring means 50 as long as it can measure the amount of the strip S present in the festoon 28.

[0031] In this forming apparatus 2, the front festoon 28F is provided with a measuring means 50. The measuring means 50 is provided with a pair of sprockets 52 arranged above and below, and a chain 54 that spans the pair of sprockets 52. The pair of sprockets 52 are rotatably attached to the support frame 44 on the extrusion unit 4 side of the first half festoon 28F.

[0032] 2 and 3 show an overview of the festoon 28. Fig. 2 shows a state in which the moving member 32 is farthest from the reference member 30. In this state, the distance between the reference member 30 and the moving member 32 is the longest. Fig. 3 shows a state in which the moving member 32 is closest to the reference member 30. In this state, the distance between the reference member 30 and the moving member 32 is the shortest. In this molding apparatus 2, the distance between the upper and lower sprockets 52 is adjusted so that the movement range of the moving member 32 is included between the pair of sprockets 52.

[0033] In this forming apparatus 2, the lower sprocket 52 is attached to the rotating shaft of the rotary encoder 56. As described above, the chain 54 is stretched between the upper sprocket 52 and the lower sprocket 52. One end of the moving member 32 is fixed to the chain 54. Therefore, the chain 54 moves in accordance with the movement of the moving member 32. This causes the sprocket 52 to rotate, and the rotary encoder 56 detects the rotation of the sprocket 52. The distance between the reference member 30 and the moving member 32 is obtained from the detected number of rotations of the sprocket 52. The amount of strip S present in the first half festoon 28F is obtained based on the distance from the reference member 30 to the moving member 32.

[0034] The carry-in section 24 is located between the extrusion unit 4 and the festoon section 22. The carry-in section 24 sends the strip S formed in the extrusion unit 4 to the festoon 28 (more specifically, the first half festoon 28F). The carry-in section 24 includes a carry-in roller 58, a plurality of tension rollers 60, and an electric motor 62. The carry-in roller 58, the plurality of tension rollers 60, and the electric motor 62 are supported by a base frame 64 of the carry-in section 24. A part of the conveyor belt 20 is hung on the carry-in roller 58 and the multiple tension rollers 60. The carry-in roller 58 is attached to a rotating shaft 62a of an electric motor 62. The electric motor 62 is a servo motor. The electric motor 62 is continuously driven in synchronization with the extruder 12. The carry-in roller 58 rotates in synchronization with the forming speed of the strip S in the extrusion unit 4. The carry-in roller 58 drives the conveyor belt 20. As the carry-in roller 58 rotates, the empty conveyor belt 20 is pulled out from the latter half festoon 28S and taken into the carry-in section 24. The adhesion roller 66 places the strip S formed in the extrusion unit 4 on the conveyor belt 20. The conveyor belt 20 carrying the strip S is sent to the first half festoon 28F. The carry-in roller 58 sends the strip S to the first half festoon 28F.

[0035] The discharge section 26 is located between the festoon section 22 and the forming unit 6. The discharge section 26 sends the strip S of the first half festoon 28F to the forming unit 6. The discharge section 26 includes a discharge roller 68, a plurality of tension rollers 70, and an electric motor 72. Although not shown, like the aforementioned feed section 24, the discharge roller 68, the plurality of tension rollers 70, and the electric motor 72 are supported by a frame of the discharge section 26. A part of the conveyor belt 20 is hung on the discharge roller 68 and the multiple tension rollers 70. The discharge roller 68 is attached to a rotating shaft 72a of an electric motor 72. The electric motor 72 is a servo motor. The electric motor 72 drives intermittently in synchronization with the drum 16. The discharge roller 68 rotates in synchronization with the winding speed of the strip S in the forming unit 6. The discharge roller 68 drives the conveyor belt 20. As the discharge roller 68 rotates, the conveyor belt 20 carrying the strip S is pulled out from the first half festoon 28F and taken into the discharge section 26. The strip S is peeled off from the conveyor belt 20 by the peeling roller 74, and the strip S is placed on the drum 16 alone. The discharge roller 68 sends the strip S to the forming unit 6. The empty conveyor belt 20 is sent to the second half festoon 28S.

[0036] The control unit 10 controls the operations of the molding apparatus 2, such as the extrusion unit 4, the molding unit 6, and the conveying unit 8. The control unit 10 is composed of, for example, a programmable sequencer, a microcomputer, a personal computer, or other control devices.

[0037] 4 is a conceptual diagram showing an example of the control unit 10. The control unit 10 includes a calculation unit 76 consisting of a CPU (Central Processing Unit), a storage unit 78 in which processing procedures are stored, and a working memory 80 for reading the processing procedures from the storage unit 78. The control unit 10 may be provided with a display unit for displaying processing results and the like, and an operation unit for an operator to operate.

[0038] The calculation unit 76 is connected to the extruder 12 of the extrusion unit 4, the electric motor 62 that drives the carry-in rollers 58 of the carry-in section 24, the electric motor 72 that drives the carry-out rollers 68 of the carry-out section 26, and a drive means for the drum 16 of the molding unit 6. This controls the operation of the carry-in rollers and the carry-out rollers, specifically, the speed (also referred to as the rotation speed) and drive time of the carry-in rollers 58 and the carry-out rollers 68. The calculation unit 76 is further connected to the measurement means 50 of the festoon section 22. This causes the number of rotations of the sprocket 52 detected by the rotary encoder 56 of the measurement means 50 to be recorded in the memory unit 78.

[0039] Next, a method for forming a tubular member C using the forming device 2 will be described along with the operation of the forming device 2. Fig. 5 shows the forming device 2 before the start of formation of the tubular member C. As shown in Fig. 5, in the forming device 2 before the start of formation of the tubular member C, the conveyor belt 20 is stocked on the latter half festoon 28S.

[0040] In this forming method, the forming speed of the strip S in the extrusion unit 4 is determined in consideration of the kneading state of the unvulcanized rubber in the extruder 12. The winding speed of the strip S in the molding unit 6 is determined in consideration of tire productivity. In this forming method, the strip S is formed at a speed slower than the winding speed of the strip S. As shown in FIG. 1, after a predetermined amount of strip S is stocked in the first half festoon 28F, the formation of the cylindrical member C starts.

[0041] In this forming method, the extruder 12 of the extrusion unit 4 is driven. This starts the formation of the strip S. The motor 62 for the feed roller 58 is driven. The feed roller 58 rotates, and the conveyor belt 20 is pulled out from the latter half festoon 28S. The strip S is placed on the conveyor belt 20 at the adhesion roller 66. The conveyor belt 20 carrying the strip S is sent to the first half festoon 28F. The strip S is stocked in the first half festoon 28F.

[0042] When the amount of the strip S in the first half festoon 28F reaches a predetermined amount, the motor 72 for the discharge roller 68 is driven. This rotates the discharge roller 68, and the conveyor belt 20 carrying the strip S is pulled out from the first half festoon 28F. The strip S is sent from the first half festoon 28F towards the forming unit 6. Furthermore, the driving means of the drum 16 is driven, and the drum 16 starts to rotate. The strip S is peeled off from the conveyor belt 20 by the peeling roller 74, and the strip S is placed on the rotating drum 16. This starts the formation of the tubular member C. The conveyor belt 20, which has been emptied after the strip S has been peeled off, is sent to the latter half festoon 28S. This allows the empty conveyor belt 20 to be stocked in the latter half festoon 28S.

[0043] When the formation of the tubular member C is completed, the rotation of the drum 16 and the discharge roller 68 is stopped, and the storage of the strip S in the first half festoon 28F is started. When the amount of the strip S in the first half festoon 28F reaches a predetermined amount, the drum 16 and the discharge roller 68 are driven, and the formation of the tubular member C is resumed. In this forming method, the storage of the strip S and the formation of the tubular member C are repeated until the required number of tubular members C are obtained. Although not described in detail, the completed tubular member C is removed from the drum 16 and sent to equipment for the next process.

[0044] In this forming device 2, the control unit 10 calculates the amount of the strip S discharged by the discharge roller 68 from the first half festoon 28F to the forming unit 6 from the start to the end of the formation of one cylindrical member C, that is, the amount of the strip S discharged by the discharge roller 68 from the start to the end of the formation of the cylindrical member C, using the speed and driving time of the discharge roller 68 during that time. Furthermore, the amount of the strip S formed by the extrusion unit 4 and delivered by the delivery roller 58 to the first half festoon 28F from the start to the end of the formation of the cylindrical member C, that is, the amount of the strip S delivered by the delivery roller 58 from the start to the end of the formation of the cylindrical member C, is calculated using the speed and driving time of the delivery roller 58 during that time. Then, the difference between the amount of the strip S discharged and the amount of the strip S delivered is calculated.

[0045] The discharged amount of strip S is the amount of strip S used in forming the tubular member C. The brought-in amount of strip S is the amount of strip S replenished into the first half festoon 28F between the start and end of the formation of the tubular member C in order to form the tubular member C. Therefore, the difference between the discharged amount of strip S and the brought-in amount of strip S between the start and end of the formation of the tubular member C represents the amount of strip S stocked in the first half festoon 28F at the start of the formation of the tubular member C, i.e., the stock amount of strip S at the start of the formation of the tubular member C. The stock amount of strip S at the start of the formation of the tubular member C is obtained based on the discharged amount of strip S and the brought-in amount of strip S.

[0046] In this forming device 2, the speed and drive time of the discharge roller 68 do not take into account slippage of the conveyor belt 20 relative to the discharge roller 68. The speed and drive time of the feed roller 58 do not take into account slippage of the conveyor belt 20 relative to the feed roller 58. The stock amount of the strip S at the start of formation of the above-mentioned tubular member C is equal to an amount that is preset as the amount of the strip S to be stocked in the first half festoon 28F by the start of formation of the tubular member C.

[0047] In this forming apparatus 2, the control unit 10 calculates the amount of strip S present in the first half festoon 28F from the number of rotations of the sprocket 52 detected by the rotary encoder 56 of the measuring means 50. The number of rotations of the sprocket 52 detected by the rotary encoder 56 directly reflects the distance from the reference member 30 to the moving member 32. Therefore, in this forming apparatus 2, the net amount of strip S present in the first half festoon 28F can be obtained.

[0048] As described above, in this forming apparatus 2, a predetermined amount of strip S is stocked in the first-half festoon 28F before the formation of the tubular member C is started. Therefore, the difference between the amount of strip S present in the first-half festoon 28F at the start of the formation of the tubular member C and the amount of strip S present in the first-half festoon 28F at the end of the formation of the tubular member C represents the change in the amount of strip S in the first-half festoon 28F due to the formation of the tubular member C, that is, the change in the amount of strip S in the first-half festoon 28F (also referred to as the amount used). The change in the amount of strip S in the first-half festoon 28F is obtained based on the amount of strip S present in the first-half festoon 28F.

[0049] In this forming device 2, the control unit 10 judges whether or not the conveyor belt 20 is slipping based on the amount of strip S discharged by the discharge roller 68, which is calculated using the speed and drive time of the discharge roller 68, the amount of strip S brought in by the bring-in roller 58, which is calculated using the speed and drive time of the bring-in roller 58, and the amount of strip S present in the first half festoon 28F. Specifically, the control unit 10 judges whether or not the conveyor belt 20 is slipping by comparing the stock amount of strip S at the start of formation of the tubular member C, which is obtained based on the amount of strip S discharged and the amount of strip S brought in, with the amount of strip S in the first half festoon 28F, which is obtained based on the amount of strip S present in the first half festoon 28F.

[0050] If there is no slippage of the conveyor belt 20 relative to the discharge roller 68 or relative to the carry-in roller 58, the stock amount of the strip S at the start of formation of the tubular member C is equal to the amount of change in the strip S in the first half festoon 28F. Therefore, the difference between the stock amount of the strip S at the start of formation of the tubular member C and the amount of change in the strip S in the first half festoon 28F is usually 0 (zero). In contrast, for example, when slippage occurs in the conveyor belt 20 relative to the discharge roller 68, the amount of strip S used in forming the tubular member C decreases. Therefore, the amount of strip S present in the first-half festoon 28F at the end of formation of the tubular member C increases. This reduces the amount of change in the strip S in the first-half festoon 28F. In this case, the difference between the stock amount of strip S at the start of formation of the tubular member C and the amount of change in the strip S in the first-half festoon 28F is greater than zero. Therefore, by setting a threshold value for the difference between the stock amount of the strip S at the start of formation of the tubular member C and the change amount of the strip S in the first half festoon 28F in consideration of the quality of the tire, slippage of the conveyor belt 20 that may cause deterioration of the tire quality can be detected by the control unit 10. The control unit 10 of this forming device 2 can detect slippage of the conveyor belt 20.

[0051] In this forming device 2, it is possible to detect slippage of the conveyor belt 20, which may cause deterioration in the quality of the tire. By monitoring the difference between the stock amount of the strip S at the start of forming the tubular member C and the change amount of the strip S in the first half festoon 28F, the forming device 2 can also detect signs of changes in the condition of the conveyor belt 20. Since abnormalities in the conveyor belt 20 can be detected early, the forming device 2 can prevent problems caused by the conveyor belt 20 before they occur. For example, when two molding devices 2 are used to form a tire tread in two parts, one on the left side and one on the right side of the equatorial plane, it is possible to detect imbalance between the left and right sides by monitoring the formation status of each part.

[0052] By using this molding device 2, it is possible to select low-quality tires not as tires but at the stage of forming the tubular member C. This molding device 2 can prevent the formation of low-quality tires. This molding device 2 can contribute to the stable production of high-quality tires.

[0053] This molding device 2 can reduce the waste of tires due to quality abnormalities. Moreover, this molding device 2 does not require the introduction of dedicated equipment that can monitor the moving speed of the conveyor belt 20 in order to detect slippage of the conveyor belt 20. With this molding device 2, the benefits that can be obtained by introducing dedicated equipment can be obtained with only a small investment. This molding device 2 can contribute not only to the stable production of high-quality tires, but also to reducing production costs.

[0054] The feed rollers 58, the discharge rollers 68, the measuring means 50 and the control unit 10 constituting this forming apparatus 2 constitute a conveyor belt slippage detection device (hereinafter referred to as slippage detection device) that detects slippage of the conveyor belt 20 in the conveyor unit 8 having the festoon 28 that places the strip S formed by the extrusion unit 4 on the conveyor belt 20 and conveys it to the forming unit 6 and stores the strip S. This forming apparatus 2 includes the slippage detection device.

[0055] This slippage detection device is equipped with the aforementioned feed rollers 58, discharge rollers 68, measuring means 50, and control unit 10, and is therefore capable of detecting slippage of the conveyor belt 20. By having this slippage detection device in a tire building apparatus, it is possible to detect slippage of the conveyor belt 20, which could lead to a deterioration in tire quality. This slippage detection device can contribute to the stable production of high-quality tires. Moreover, the introduction cost of this slippage detection device is cheaper than the introduction cost of dedicated equipment capable of monitoring the movement speed of the conveyor belt 20. This slippage detection device can be introduced into the building apparatus at low cost. This slippage detection device can also contribute to reducing production costs.

[0056] As described above, according to the present invention, it is possible to obtain a tubular member forming apparatus and a conveyor belt slippage detection device that can contribute to the stable production of high-quality tires. [Industrial Applicability]

[0057] The above-described technique for detecting slippage of a conveyor belt can be applied to various conveying devices that use a conveyor belt. [Explanation of symbols]

[0058] 2...Molding equipment 4. Extrusion unit 6. Molding unit 8. Transport unit 10. Control unit 12... Extruder 16...Drums 20. Conveyor belt 22. Festoon Section 24 Loading area 26...Exit section 28, 28F, 28S... Festoon 30... Reference member 32... Moving member 34... Reference Frame 36... Pulley of reference member 30 38... Moving frame 40: Pulley of moving member 40 50. Measurement methods 52···Sprocket 54 Chain 56 Rotary Encoder 58···Loading roller 62 ... Electric motor of loading section 24 68···Extraction roller 72 ... Electric motor of discharge section 26

Claims

1. an extrusion unit forming a band-like strip of unvulcanized rubber; a forming unit for spirally winding the strip to form a tubular member; a conveying unit located between the extrusion unit and the molding unit, for conveying the strip on a conveying belt; a control unit for controlling the operations of the extrusion unit, the molding unit, and the conveying unit; Equipped with the conveying unit includes a festoon for stocking the strip, an input section for feeding the strip to the festoon, and an output section for feeding the strip to the forming unit, the carry-in section includes a carry-in roller that rotates in synchronization with the push-out unit and drives the conveyor belt, the discharge section includes a discharge roller that rotates in synchronization with the forming unit and drives the conveyor belt, the festoon comprises a measuring means for measuring the amount of the strip present on the festoon; the control unit determines whether or not the conveyor belt is slipping based on an amount of the strip discharged by the discharge roller, which is calculated using a speed and a drive time of the discharge roller, an amount of the strip delivered by the delivery roller, which is calculated using a speed and a drive time of the delivery roller, and an amount of the strip present in the festoon. A molding device for tubular members.

2. the control unit determines whether or not the conveyor belt is slipping by comparing an amount of the strip stock at the start of formation of the tubular member, the amount being obtained based on the amount of the strip carried out and the amount of the strip brought in, with an amount of the strip change in the festoon, the amount being obtained based on the amount of the strip present in the festoon; a stock amount of the strip at the start of formation of the tubular member is represented by a difference between an amount of the strip carried out and an amount of the strip carried in from the start to the end of formation of the tubular member, the change in the amount of the strip in the festoon is represented by a difference between an amount of the strip present in the festoon at the start of formation of the tubular member and an amount of the strip present in the festoon at the end of formation of the tubular member; The apparatus for forming a tubular member according to claim 1 .

3. the festoon includes a reference member and a movable member that is arranged vertically in line with the reference member and is supported so as to be vertically movable; The reference member includes a reference frame and a plurality of pulleys attached to the reference frame and spaced equally apart along a length of the reference frame; The moving member includes a moving frame and a plurality of pulleys attached to the moving frame and arranged at equal intervals along the length of the moving frame; the conveyor belt is alternately wound around the pulleys of the reference member and the pulleys of the moving member; The amount of the strip present on the festoon is obtained based on the distance from the reference member to the moving member. The molding apparatus for a tubular member according to claim 1 or 2.

4. A conveyor belt slippage detection device for detecting slippage of a conveyor belt in a conveyor unit, the conveyor belt detecting slippage of the conveyor belt in a conveyor unit that places a belt-shaped strip made of unvulcanized rubber formed by an extrusion unit on the conveyor belt, conveys the strip to a molding unit that spirally winds the strip to form a tubular member, and has a festoon for storing the strip, an input roller for feeding the strip to the festoon; a discharge roller for feeding the strip to the forming unit; a measuring means for measuring the amount of said strip present on said festoon; a control unit for controlling the operation of the carry-in rollers and the carry-out rollers; Equipped with The feed roller rotates in synchronization with the push-out unit to drive the conveyor belt; the discharge roller rotates in synchronization with the forming unit to drive the conveyor belt; the control unit determines whether or not the conveyor belt is slipping based on an amount of the strip discharged by the discharge roller, which is calculated using a speed and a drive time of the discharge roller, an amount of the strip delivered by the delivery roller, which is calculated using a speed and a drive time of the delivery roller, and an amount of the strip present in the festoon. A device for detecting slippage of conveyor belts.

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