Method for manufacturing tire blanks

Abstract

A method for automatically and continuously setting elastomeric elements using an apparatus (10) for manufacturing tire blanks is disclosed. The apparatus (10) for manufacturing tire blanks includes a drum (16) for manufacturing tire blanks and at least one cooperative robotic arm (18) equipped with at least one actuator (20). The method includes the step of setting the elastomeric elements, which includes a predetermined sequence of sub-steps, including sub-steps of grasping the elastomeric elements with the arm and pulling the elastomeric elements toward the drum. The automatic and continuous setting of the elastomeric elements includes instructions that can be executed by a processor of a control unit to perform: - an automatic execution step (110) according to a sub-step of the sequence; - an interruption step (120) of the sequence; - a manual execution step (130) according to an interruption sub-step or the next sub-step of the sequence.

Description

Technical Field

[0001] This invention relates to the field of tire manufacturing, and more particularly, to a method for manufacturing tire blanks and equipment that allows this method to be carried out. Background Technology

[0002] A tire is divided into three distinct areas: the crown reinforcement and tread, which are designed to contact the ground; the bead, which ensures the tire attaches to the rim; and the sidewall, which connects the crown to the bead. To connect the crown to the bead, a tire typically includes a carcass reinforcement.

[0003] To manufacture the tire blank, elements in the form of bead cores, strips, or ply layers are sequentially assembled to form a cylindrical carcass reinforcement. The cylindrical carcass reinforcement is then transformed into a ring-shaped carcass reinforcement in a process known as the configuration stage. During this transformation, the crown of the carcass reinforcement is stretched to increase its diameter, and the bead moves axially together and comes closer together. Finally, elements in the form of strips or ply layers are sequentially positioned on the crown of the carcass reinforcement to form the crown reinforcement and tread at the top.

[0004] The assembly and configuration stages typically take place on a cylindrical drum used to manufacture tire blanks, which can rotate about an axis of rotational symmetry. During production, elements in the form of cords, strips, or ply fabric are laid circumferentially onto the drum or tire blank. The laying stage can be performed manually or automatically.

[0005] When the laying stage is performed manually, during production, an operator facing a drum picks up the end of an element (such as a ply of fabric wound around a spool), pulls it toward the drum, positions it, and secures it to the drum or tire blank. The drum is then set to rotate for a complete rotation. During the drum's rotation, the operator guides the ply of fabric so that the winding forms a substantially straight cylinder. The operator then cuts the ply of fabric and adjusts the joints between the ends of the ply. However, manual execution has well-known drawbacks. In particular, the operator's speed and precision are limited. Approaching or exceeding these limits increases the operator's workload and cognitive load, which can lead to a decrease in the quality of the produced tire blank or even reduce operator safety.

[0006] Furthermore, automating the manually performed laying phase presents significant technical challenges, such as designing production machines capable of implementing the laying phase, and, most importantly, programming the machines to perform the laying phase.

[0007] When manufacturing tire blanks automatically, there are multiple design strategies that result in a variety of methods and machines.

[0008] For example, a tire blank manufacturing machine is known in which a drum can move between several paving stations by means of a carriage or robotic arm, each station capable of laying a specific element (such as a bead core or strip). Because the productivity of each station differs, the fastest paving stations are not fully utilized, which reduces their efficiency. Furthermore, the design, production, and use of such an assembly machine are highly complex and expensive. In fact, the machine's reliability—or in other words, its ability to produce defect-free tire blanks—is reduced because this is due to the product of the reliability of each individually acquired paving station. Therefore, the net operating time of such a machine is less advantageous than that of a machine with fewer paving stations.

[0009] A tire blank manufacturing machine is also known, which comprises only two laying stations, each capable of laying a set of pre-assembled components. Thus, two complete rotations of the drum are sufficient to lay a first set intended to form the carcass reinforcement and a second set intended to form the crown reinforcement and tread. Nevertheless, such a manufacturing machine requires adjustments to the structure and composition of the tire blank, which imposes considerable limitations on the tire design and industrialization process. Summary of the Invention

[0010] The purpose of this invention is to overcome the shortcomings of the prior art and provide a flexible and efficient solution.

[0011] This objective is achieved by the present invention, in a first aspect, which relates to a method for automatically and continuously laying elastomer elements using equipment for manufacturing tire blanks, the equipment comprising a drum for manufacturing tire blanks and at least one cooperative robotic arm equipped with at least one actuator.

[0012] The stage of laying the elastomeric element includes a predetermined sequence of steps, which includes grasping the elastomeric element with the arm and pulling the elastomeric element toward the drum.

[0013] The automatic continuous laying of the elastomer element includes instructions that can be executed by the processor of the control unit:

[0014] - Automatically execute the phases according to the steps of the sequence.

[0015] - The interruption phase of the sequence;

[0016] - The interruption step or the manual execution phase of the next step according to the sequence.

[0017] Therefore, the laying station can automatically lay any component, such as bead cores, strips, or plywood, or any set of pre-assembled components. Different components are laid automatically using the same laying device (i.e., one or more robotic arms). Thus, the assembly equipment is more flexible than prior art multi-station automated assembly machines, where each station is dedicated to laying specific components or pre-assembled sets.

[0018] Furthermore, the production method according to the invention allows for the collaborative manufacturing of tire blanks, which offers the advantage of avoiding systematic operator intervention in low-value-added, non-ergonomic tasks. For example, the operator only needs to intervene when laying certain elastomer products that are not yet suitable for or programmed by the robotic arm, or to monitor the quality of the tire blanks during production.

[0019] Furthermore, the "grabbing the elastomeric element and pulling it toward the drum" type of laying method is particularly suitable for manual laying of elastomeric elements. Therefore, the collaborative work between the robotic arm and the operator can reduce the duration of operator intervention and increase the net uptime of the manufacturing equipment. "Net time" refers to the time it takes for the machine to manufacture the tire blank, excluding time related to productivity differences and malfunctions.

[0020] Finally, robotic arms are more precise and faster than operators, which allows for improved quality of manufactured tire blanks and increased useful uptime of manufacturing equipment. "Useful time" refers to "net time," excluding time spent producing tire blanks that do not meet quality standards.

[0021] Preferably, the elastomeric element is in the form of a continuous strip, and the sequence includes a step of guiding the elastomeric element as it is wound around the drum after a pulling step, and a step of cutting and joining the element.

[0022] Similarly, this type of method is particularly well-suited for manually laying elastomer elements and therefore for collaborative work between robotic arms and operators, which can reduce the duration of operator intervention and increase the net uptime of manufacturing equipment.

[0023] Advantageously, the interruption phase includes a sub-phase indicating that the automatic execution phase of the identification step has not been successfully executed, wherein, in order to implement the sub-phase, the manufacturing equipment includes a first measuring device, a second measuring device, and a database, the first measuring device being able to assess the state of the tire blank during production, the second measuring device being able to assess the state of the manufacturing equipment, and the database containing data obtained from the first and second measuring devices, related to previously executed automatic steps, and related to the success or failure of said steps.

[0024] Therefore, the manufacturing equipment can automatically evaluate the quality of the manufactured tire blanks. Furthermore, the database provides the manufacturing equipment with the possibility of implementing an automated learning process, whether supervised or otherwise, preferably self-supervised. Such a learning process is known and described in patent US10445653. Thus, the manufacturing equipment accurately evaluates the quality of the tire blanks during production, which improves the relevance of operator intervention and also increases the useful uptime of the manufacturing equipment.

[0025] Preferably, the interruption phase includes a sub-phase where an operator detection device is used to detect the operator at the laying station of the manufacturing equipment. Therefore, the operator can intervene at the laying station to collaborate with the robotic arm and safely complete one or more steps of the manually executed laying phase.

[0026] Preferably, the first measuring device includes a three-dimensional vision device, and the second measuring device includes a force sensor arranged on the collaborative robotic arm.

[0027] Advantageously, the interruption phase includes a sub-phase after the automatic execution phase of the identification step has not indicated that it has been successfully executed, a sub-phase in which a corrective action to be executed is selected from a list of known corrective actions and according to predetermined criteria.

[0028] Therefore, manufacturing equipment can automatically perform calibration actions, which firstly limits the number of operator interventions and the overall duration of calibration actions, and secondly increases the net uptime of the manufacturing equipment.

[0029] Preferably, the interruption step or the manual execution phase of the next step in the sequence includes a capitalization sub-phase, in which the database is updated with data acquired from the first measuring device during the manual execution of the step.

[0030] Therefore, the control unit learns from failures in the automated laying phase and improves its ability to identify instructions that an ongoing automated laying phase has not been successfully executed. This can limit operator intervention and increase the net uptime of the manufacturing equipment.

[0031] Advantageously, the manual execution phase of the interruption step or the next step in the sequence includes an accumulation sub-phase, in which the list of known correction actions is updated based on data acquired from the second measuring device during the manual execution of the step.

[0032] Therefore, manufacturing equipment can select corrective actions from an increasingly comprehensive list of actions, which can limit operator intervention and increase the net uptime of the manufacturing equipment.

[0033] Preferably, the steps or correction actions are planned based on a model of an image sequence including the previously performed steps or correction actions, according to the initial configuration of the image sequence and the final configuration of the image sequence.

[0034] Therefore, manufacturing equipment can automatically plan automated laying stages or correction actions in a manner suitable for various situations. Additionally, models and vision devices provide the manufacturing equipment with means to implement the imitation process. This imitation process is known and is specifically described in the publication arXiv 1703.02018v1, dated March 6, 2017, entitled “Combining Self-Supervised Learning and Imitation for Vision-Based Rope Manipulation.”

[0035] Advantageously, the automatic execution phase of the steps according to the sequence includes an accumulation sub-phase, in which the database is updated with data acquired from the first measuring device during the automatic execution of the steps.

[0036] Preferably, the automatic execution phase of the steps according to the sequence includes an accumulation sub-phase, wherein the list of known correction actions is updated based on data acquired from the second measuring device during the automatic execution of the steps.

[0037] The present invention also relates to an apparatus for manufacturing tire blanks, comprising a drum for manufacturing tire blanks, at least one cooperative robotic arm equipped with at least one actuator, and a control unit including a processor and a memory accessed by the processor, the memory containing instructions that, once executed, cause the processor to implement a method for automatically and continuously laying elastomer elements according to a first aspect of the present invention. Attached Figure Description

[0038] The invention will be better understood through the description based on the following figures:

[0039] - Figure 1 A general schematic diagram of a manufacturing apparatus for implementing the method according to the present invention;

[0040] - Figure 2 A flowchart illustrating certain stages of the method according to the present invention is provided.

[0041] In different accompanying drawings, the same or similar elements are labeled with the same reference numerals. Therefore, they are not systematically described repeatedly. Detailed Implementation

[0042] Figure 1An apparatus 10 for manufacturing tire blanks is shown. The manufacturing apparatus includes a station 12 for supplying elastomeric elements and at least one station 14 for laying said elements. An "elastomeric element" refers to an elastomeric product that can be reinforced, calendered, or extruded according to a given profile to form a continuous strip or ply, thereby forming a set of pre-assembled elastomeric elements. The elastomeric elements are typically wound on a reel 15.

[0043] The laying station 14 includes a drum 16 (partially shown) for manufacturing tire blanks and at least one cooperating robotic arm 18 equipped with at least one actuator 20. A "laying station" generally refers to an area where elastomeric elements are laid in place. The manufacturing equipment includes a control unit capable of managing both the supply station and the laying station.

[0044] The drum 16 is cylindrical (typically straight) and rotationally symmetrical about a central axis 22. The drum is rotatable relative to a support 24 about the central axis, wherein the support itself is fixed, or movable on a horizontal plane by means of, for example, a carriage, or movable in different directions by means of, for example, a multi-axis industrial robot. The radial outer surface of the drum forms a laying surface, and a first laying element contacts the laying surface. A second laying element contacts the radial outer surface of the first laying element.

[0045] The robotic arm 18 is an anthropomorphic type with six axes and comprises a series of five variable-length segments hinged together by four joints. For example, the joints are formed by shafts and two pivots and are driven by electric motors. A first end of the arm, with a base 26 mounted to be pivotally movable via a first joint, is arranged on a fixed structure 28. A second end, with actuators (referred to as base plate 30), is mounted to be pivotally movable via a final joint. Depending on the actuators 20 used and the arrangement of the laying station 14, the arm 18 can take various forms with more or fewer axes of movement.

[0046] The robotic arm 18 is suitable for automatically and continuously laying elastomer elements on a drum 16. The actuator allows for automated laying and is selected from: pliers, suction cups, rollers, scissors, blowers, sprayers, and applicators.

[0047] The term "cooperation" refers to the fact that the robotic arm 18 is designed to perform tasks in cooperation with an operator. In other words, the arm includes proximity detectors and / or force sensors. The proximity detectors are able to detect the presence of an operator in the environment of the laying station, and the force sensors are able to detect unexpected returns of force during arm movement, such as in the event of a collision with the operator. Therefore, the arm can be fixed or its movement can be adapted to allow the operator to move and intervene safely on the laying station.

[0048] For example, manufacturing equipment 10 includes two robotic arms 18. A fixed structure 28, in the form of a metal frame, is attached to the arms 18, at least partially defining an operator's workspace 32. The size of the workspace 32 allows the operator to observe the automated or manual placement of elastomeric elements without obstruction by the robotic arms. To this end, the bases 26 of the arms are axially spaced sufficiently, preferably 0.5 m to 1.5 m apart, to allow the operator to manually place elements or elastomeric assemblies between the arms without obstruction, and / or to allow the arms to grasp elastomeric elements over the entire or partial strip length, while minimizing arm extension, where excessive extension in a given direction would create a so-called "cantilever" situation, resulting in a return force similar to a collision with the operator, rendering the arm immobile. The bases 26 of the robotic arms are then sufficiently vertically raised from the bottom of the workspace 32, preferably at least 1.5 m, thereby allowing the operator to manually place the elastomeric elements without obstructing their view. Finally, the base of the robotic arm is positioned above the drum 16, preferably at a horizontal distance of 22±0.5m from the central axis of the drum, to allow easy access to the drum and the supply station 12 while minimizing the extension of the arm.

[0049] The stages of laying the elastomeric element include a predetermined sequence of steps. According to the invention, the automated continuous laying of the elastomeric element includes instructions executable by a processor of a control unit, the control unit further including a memory accessible by the processor containing the instructions, which, upon execution, cause the processor to perform:

[0050] - Automatic execution phase based on the steps of the sequence

[0051] - The interruption phase of the sequence,

[0052] - The interruption step or the manual execution phase of the next step according to the sequence.

[0053] The manufacturing equipment includes a first measuring device, a second measuring device, and a database. The first measuring device is capable of evaluating the state of the tire blank during the production process, the second measuring device is capable of evaluating the state of the manufacturing equipment, and the database contains data acquired from the first and second measuring devices that is related to previously executed automated laying stages and the success or failure of said stages. The database is hosted on a server belonging to the control unit.

[0054] For example, the first measuring device includes means (e.g., a deformation gauge) for measuring the mass and balance of the billet around the central axis 22 of the drum, and means (e.g., a laser profilometer) for measuring the dimensions of the billet. Preferably, the first measuring device includes a three-dimensional vision device capable of accurately characterizing the profile of the billet and / or elastomer elements in real time during the laying process.

[0055] For example, the second measuring device also includes a three-dimensional vision device capable of scanning the laying site environment, and a force sensor for the robotic arm capable of measuring the return of force in the arm during the laying of the elastomeric element. Thus, the second measuring device can assess the tension of the elastomeric element, which is pulled toward a drum or guided such that the element is wound into a substantially straight cylinder.

[0056] To process the data acquired from the vision device and prevent any slowdowns during the management of the laying phase, the control unit includes a computing device of appropriate size. Additionally, the manufacturing equipment includes devices for communication with the operator, such as lampposts or portable digital devices connected to the control unit via Wi-Fi.

[0057] The control unit is particularly capable of managing the automatic laying of elastomer elements and requesting manual laying stages. Using first and second measuring devices, laying management is adapted to the characteristics of the elastomer elements to be laid, such as size, stiffness, and ductility.

[0058] In addition, the control unit can update the database with data obtained from the first and second measuring devices during manual or automatic laying, and update the list of known correction actions based on data obtained from the second measuring device during manual or automatic laying.

[0059] The supply station 12 for elastomeric elements includes a multi-axis industrial robot 34 capable of manipulating containers supporting the elastomeric elements. For this purpose, the robot is equipped with a vision device. "Supply station" also refers to the area where the industrial robot is located. Supply station 12 is adjacent to laying station 14 and includes storage space 36 in which containers are arranged. For example, the containers may take the form of a spool 15, a dispenser 38 containing the spool 15, or a roller conveyor supporting elastomeric elements that are not suitable for storage on a spool. The number of containers present in storage space 36 is appropriate to the number of elements to be laid in place during the manufacturing of tire blanks, thus limiting the area of ​​the storage space.

[0060] Method for manufacturing tire blanks

[0061] Figure 2 The flowchart illustrates a method for manufacturing tire blanks, which specifically includes the continuous laying 100 of elastomer elements using manufacturing equipment 10.

[0062] Therefore, prior to laying, the method includes a stage 90 of supplying elastomeric elements to laying station 14 via supply station 12, wherein the elements to be laid are in the form of continuous strips or ply fabric. The supply stage includes sub-stages 91 and 92, in which a multi-axis industrial robot 34 or an automated carriage grips containers (e.g., reels 15, distributors 38 containing reels 15, or roller conveyors), each container containing the elastomeric elements to be laid, and in sub-stage 92 the containers are positioned such that the elastomeric elements are in a layable state.

[0063] The method then includes a laying phase 100 automatically managed by a control unit. At least one cooperative robotic arm 18, equipped with at least one actuator 20, automatically lays the elastomeric element onto a drum 16 used to manufacture the tire blank. The laying phase includes a sequence of steps applied to the element to be laid, including detection, gripping, pulling toward the drum 16, laying and securing to the drum, guiding during winding around the drum, cutting, and joining. The arm 18 continuously performs the automated laying phases.

[0064] The automated continuous laying of elastomeric elements includes instructions that can be executed by a processor of a control unit to implement the method. According to the invention, the method includes an automated execution phase 110 of steps according to the sequence, an automated interruption phase 120 of the steps or the sequence, and a manual execution phase 130 of interrupting a step or the next step in the sequence. After the manual phase, the automated sequence of laying elements is resumed.

[0065] Interruption phase 120 includes: a first sub-phase 121 that identifies an instruction that an ongoing automatic laying phase has not been successfully executed; a second sub-phase 122 that determines the corrective action to be taken; and a third sub-phase 123 that manages the determined corrective action, including conveying intervention instructions to the operator.

[0066] The control unit uses a first measuring device, a second measuring device, and a database to identify indications that an ongoing automated laying stage has not been successfully executed. The first measuring device assesses the condition of the tire blank during production, the second measuring device assesses the condition of the manufacturing equipment, and the database contains predetermined laying tolerances, or preferably includes data acquired from the first and second measuring devices that is related to previously executed automated laying stages and to the success or failure of said stages. In other words, the control unit compares data collected during the ongoing laying stage with data collected during previous laying stages. Before comparing the data, the operator assesses the condition of the tire blank during the previous automated laying stage and notifies the database to correlate it with the success or failure of said stage.

[0067] Then, the control unit selects the correction action to be performed from a known list of correction actions according to a predetermined standard.

[0068] The control unit then manages the selected calibration actions. According to one variation, the control unit can manage automatic calibration actions to ensure the successful execution of the ongoing laying phase. Therefore, the phase of managing calibration actions also includes sub-phases of planning, executing, and verifying the calibration actions. Preferably, when the selected calibration action is manual, or when the automatic calibration action fails to execute successfully, the control unit issues an intervention command to the operator.

[0069] Based on the model of the image sequence including the previously executed laying phase or the correction action, and based on the initial configuration of the image sequence and the final configuration of the image sequence, phases 101 and 1231 for automatically laying or implementing automatic correction actions are planned.

[0070] Finally, the method includes several accumulation stages, among which:

[0071] - Update the database (first accumulation sub-stage 201) with data obtained from the first measuring device during manual laying.

[0072] - Update the list of known correction actions based on the data obtained from the second measuring device during manual laying (second accumulation sub-stage 202).

[0073] - Update the database with data obtained from the first measuring device during automatic laying (third accumulation sub-stage 203);

[0074] - Update the list of known correction actions based on the data acquired from the second measuring device during automatic laying (fourth accumulation sub-stage 204).

Claims

1. A method for automatically and continuously laying elastomer elements using equipment (10) for manufacturing tire blanks, wherein the equipment (10) for manufacturing tire blanks includes Drum-shaped objects used to manufacture tire blanks (16). At least one collaborative robotic arm (18) equipped with at least one actuator (20). The stage of laying the elastomeric element includes a predetermined sequence of steps, which includes grasping the elastomeric element with the arm and pulling the elastomeric element toward the drum. in, The automated continuous laying of elastomer elements includes instructions that can be executed by the processor of the control unit: - Automatic execution phase (110) of the steps according to the sequence. - The interruption phase of the sequence (120); - The manual execution phase (130) of the interruption step or the next step according to the sequence.

2. The method according to claim 1, wherein, The elastomeric element takes the form of a continuous strip, and the sequence includes a step of guiding the elastomeric element as it winds around the drum (16) after a pulling step, and a step of cutting and joining the element.

3. The method according to claim 1 or 2, wherein, The interruption phase (120) includes the first sub-phase (121) indicating that the automatic execution phase of the identification step has not been successfully executed. In order to implement the first sub-stage, the equipment (10) for manufacturing tire blanks includes a first measuring device, a second measuring device, and a database. The first measuring device is capable of evaluating the state of the tire blanks during the production process, the second measuring device is capable of evaluating the state of the equipment for manufacturing tire blanks, and the database contains data obtained from the first and second measuring devices that are related to previously executed automatic steps and to the success or failure of those steps.

4. The method according to claim 3, wherein, The interruption phase (120) includes a sub-phase in which the operator at the laying station of the equipment used to manufacture tire blanks is detected using an operator detection device.

5. The method according to claim 3, wherein, The first measuring device includes a three-dimensional vision device, and the second measuring device includes a force sensor arranged on a collaborative robotic arm (18).

6. The method according to claim 3, wherein, The interruption phase (120) includes a first sub-phase (121) after the indication that the automatic execution phase of the identification step has not been successfully executed, and a second sub-phase (122) after which a correction action to be executed is selected from the list of known correction actions and according to a predetermined criterion.

7. The method according to claim 3, wherein, The interruption step or the manual execution phase (130) of the sequence includes a first accumulation sub-phase (201) in which the database is updated with data acquired from the first measuring device during the manual execution of the step.

8. The method according to claim 6 or 7, wherein, The interruption step or the manual execution phase (130) of the sequence includes a second accumulation sub-phase (202), in which the list of known correction actions is updated based on data acquired from the second measuring device during the manual execution of the step.

9. The method according to claim 6, wherein, Based on the model of the image sequence including the previously performed steps or correction actions, the steps or correction actions (101, 1231) are planned according to the initial configuration of the image sequence and the final configuration of the image sequence.

10. The method according to claim 3, wherein, The automatic execution phase of the steps according to the sequence includes a third accumulation sub-phase (203), in which the database is updated with data acquired from the first measuring device during the automatic execution of the steps.

11. The method according to claim 6, wherein, The automatic execution phase of the steps according to the sequence includes a fourth accumulation sub-phase (204), in which the list of known correction actions is updated based on data acquired from the second measuring device during the automatic execution of the steps.

12. An apparatus (10) for manufacturing tire blanks, comprising: Drum-shaped objects used to manufacture tire blanks (16). At least one collaborative robotic arm (18) equipped with at least one actuator (20). The control unit includes a processor and a memory accessible by the processor, the memory containing instructions that, once executed, cause the processor to perform the method of automatically and continuously laying elastomer elements as described in any one of claims 1 to 11.

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