Method and system for improving tire sidewall depression by stacking tire sidewall joint and cord fabric joint, and tire

Abstract

The invention relates to the technical field of tire production, in particular to a method and system for improving a tire sidewall recess by stacking a tire sidewall joint and a cord fabric joint and a tire. In the tire forming process, accurate process control is adopted, so that the tire side joint and the cord fabric joint coincide in the circumferential direction, and a unified coincide reinforcing area is formed. By controlling the circumferential coincidence error and ensuring the radial projection overlap of the joint area, the recess depth of the sidewall can be effectively reduced, and the appearance quality can be improved. According to the method, the appearance of the tire is remarkably improved and the qualification rate is increased only by optimizing the joint position and angle without changing a rubber material formula or increasing the thickness of sidewall rubber. The embodiment shows that the sidewall depression is reduced to 0.45 mm from conventional 0.7 mm, and the percent of pass is improved to 87.62%. The invention provides a tire manufacturing process which is simple, convenient, efficient and suitable for batch production, and has a relatively strong industrial application prospect.

Description

Technical Field

[0001] This invention relates to the field of tire manufacturing technology, and in particular to a method, system, and tire for improving tire sidewall depressions by superimposing sidewall joints and cord joints. Background Technology

[0002] The sidewall of radial tires not only bears a certain load and provides protection, but it is also one of the most visually appealing areas for end customers. As the vehicle market increasingly demands consistency, refinement, and brand recognition in tire appearance, sidewall defects (such as localized dents, undulations, and ripples) have become a crucial indicator for tire manufacturers' process quality control. In practice, sidewall dents are often not caused by defects in a single material, but rather by the "joint / splicing structure" of multi-layered components in the tire molding process: cord joints are inevitably formed when the carcass ply is cut and wound into a tube; sidewall joints are also unavoidable during the bonding and overlapping of the sidewall rubber. These joint locations typically exhibit localized stiffness differences due to cord overlap / butt joints, localized thickness differences due to rubber overlap, and differences in thermal history during vulcanization. After vulcanization and cooling, inconsistencies arise between the joint area and the surrounding matrix material in terms of shrinkage, modulus evolution, and residual stress distribution, resulting in visible localized dents or unevenness on the sidewall surface. While such defects may be more of an appearance quality issue in some scenarios, they can significantly reduce the product appearance pass rate, increase rework and scrap, and adversely affect the company's process stability and cost control.

[0003] To reduce or eliminate tire sidewall indentations, several technical approaches have emerged, including: first, structural modifications to the ply joint itself; second, reinforcement or strengthening of the ply joint area; and third, reducing fluctuations caused by the joint from the perspective of component manufacturing or molding uniformity. However, these solutions mostly focus on "improving the structure or strength of a single component joint," and the utilization of the process parameter of "the relative positional relationship between different component joints" remains relatively insufficient.

[0004] For example, US Patent 4466473A discloses a splicing structure of tire carcass ply material and its preparation method. Its core focus is on the configuration and connection method of the ply / cord at the splicing point. By optimizing specific splicing morphologies (such as butt joint / overlap configurations), it improves the structural continuity and uniformity of the splicing area, thereby reducing problems such as local unevenness, abnormal appearance, or performance fluctuations caused by the splicing area. The advantage of this technology is that it does not change the overall tire structure; simply improving the geometry and connection method of the ply joint can alleviate local stiffness abrupt changes caused by the ply joint to a certain extent. However, its limitations are equally obvious: its focus remains on "structural optimization of the ply joint itself," without considering the synergistic relationship between the sidewall rubber joint and the ply joint in the same circumferential / radial region from the perspective of multi-component coupling during tire forming. In other words, even if the ply joint is optimized, if the sidewall joint and the ply joint are still dispersed circumferentially, inconsistent shrinkage after vulcanization and cooling may still create new unevenness or depressions on the sidewall, making it difficult to consistently achieve a significant improvement in appearance.

[0005] Another typical solution is exemplified by Chinese patent CN101073922A, which discloses a method for splicing radial tire carcass ply fabric. This method involves applying tackifying films to both sides of the ply splice to increase the bonding area and improve connection strength. The process includes pre-applying the films to a cutting machine or forming drum and then applying the films after splicing. This approach aims to reduce the risk of delamination at the ply splice and improve joint strength, which is beneficial for tire durability and safety. However, considering the mechanism of sidewall dents—a visible defect—the tackifying films essentially alter the local thickness and stiffness distribution near the splice, making the area "harder" or "thicker." Therefore, their improvement on dents caused by inconsistent shrinkage may not be unidirectional. In some cases, the stiffness step introduced by the reinforcing material may actually exacerbate the shrinkage traction effect of the surrounding material, leading to more sensitive appearance undulations. Furthermore, this type of solution still focuses on strengthening a single point of the cord joint, lacking a systematic design for the relative positions of the sidewall joint and the cord joint (such as whether they overlap, how much they are offset, and their angular relationship with other layer joints). Therefore, it still has limitations in achieving the goal of "significantly reducing and stably reproducible sidewall indentation".

[0006] Some technologies address the variable parameters and uniformity of tire component manufacturing, attempting to reduce manufacturing fluctuations in ply / composite components. For example, US Patent 20060137804A1 discloses a method for manufacturing tire ply (or reinforcing rubber fabric) that allows adjustment or variation of parameters such as cord spacing, cord angle, thickness (rubber layer / specification), and width without stopping the machine, thereby improving the controllability and consistency of component manufacturing. Such solutions are valuable in terms of "component-level consistency control," reducing localized non-uniformity caused by cutting, molding, or manufacturing errors. However, for sidewall indentations, the key issue is often not solely caused by "fluctuations in single component parameters," but rather by the superposition of multiple stiffness differences, thermal history differences, and residual stress differences resulting from the circumferential distribution of multiple component joints. In other words, even if the manufacturing consistency of individual components (such as the ply) is improved, as long as the sidewall joints and ply joints are still misaligned in the tire circumferential direction in the conventional way, two or more stress concentration points may still form after vulcanization and cooling. The area between them is prone to forming an "asymmetric deformation zone" during contraction and rebound, which manifests as dents or unevenness on the sidewall surface. Therefore, relying solely on improving the manufacturing consistency of components is often insufficient to achieve a significant and stable reduction in sidewall dents without increasing costs or changing the structure.

[0007] Based on the above existing technologies, it can be seen that: 1) Existing solutions mostly start from the cord joint itself, improving the continuity and durability of the local structure by changing the splicing structure or enhancing the joint strength. However, the improvement of tire sidewall dents is uncertain and can easily introduce new thickness / stiffness steps; 2) Existing solutions also start from the perspective of component manufacturing consistency. However, they mainly solve the problem of controllable and consistent component parameters, and cannot directly address the root cause of inconsistent residual stress and shrinkage caused by the "relative positional relationship of different component joints in the circumferential direction".

[0008] Therefore, those skilled in the art still urgently need a new technical approach: to significantly improve the smoothness of the tire sidewall appearance by optimizing and controlling key process parameters (especially the relative positional relationships of joints of different components) based on the structural synergy mechanism of the tire molding process, without significantly increasing material costs, introducing additional safety risks, and altering the existing rubber compound formulation system as much as possible. This improvement should be replicable in batches and subject to process-level control. These needs constitute the practical background for further improvements and innovations in this invention. Summary of the Invention

[0009] The technical objective of this invention is to provide a method for effectively reducing sidewall dents by optimizing the relative positional relationship between the sidewall joint and the cord joint during tire molding. This method improves stress distribution and shrinkage behavior in the joint area by precisely controlling the overlap of the sidewall joint and the cord joint in the tire circumferential direction, significantly improving the smoothness of the tire sidewall appearance and solving the problem of sidewall dents caused by uneven joint positions in existing technologies, thereby improving the tire's appearance quality and production stability.

[0010] Firstly, in order to achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0011] A method for improving tire sidewall depression by superimposing a sidewall joint and a cord joint, the method comprising the following steps:

[0012] S1, Establish circumferential angular coordinates on the tire forming drum. and set the target joint angle. ;

[0013] S2, in the circumferential angular coordinates The carcass ply is wound to form a carcass ply tube, and the circumferential ends of the carcass ply are joined to form a ply joint, such that the angle position corresponding to the center line of the ply joint is . And control the alignment error of the curtain joint. Not greater than the curtain alignment threshold ; The angle position of the center line of the curtain joint. , This is the upper limit of the alignment error of the curtain fabric;

[0014] S3, attach the sidewall adhesive to the outside of the tire carcass ply and join the circumferential ends of the sidewall adhesive to form a sidewall joint, such that the angle position corresponding to the center line of the sidewall joint is... , This refers to the angle position of the center line of the tire sidewall joint;

[0015] S4, Obtain the real-time angle of the forming drum based on the angle acquisition unit. and obtain based on the connector identification unit and The controller calculates the circumferential coincidence error. It also controls the actuator to compensate for the rotation angle of the forming drum and the starting angle of the sidewall adhesive bonding, so that... Not greater than the maximum overlap error Simultaneously, the overlap ratio of the sidewall joint overlap width and the cord joint overlap width projected onto the tire's radial cross-section is increased. Not less than the overlap threshold This creates overlapping reinforcement zones on the tire carcass.

[0016] S5, the green tire forming the overlapping reinforcement zone is vulcanized, and the sidewall indentation value is measured after vulcanization under specified inflation and resting conditions. ,when Exceeding the indentation control threshold At that time, based on and For the next tire The initial angle of the sidewall adhesive bonding is corrected and updated.

[0017] As a preferred option and .

[0018] As a preferred option ;in, Determine using the following formula:

[0019] ;

[0020] and satisfy ;in, The projected width of the tire sidewall joint overlap band on the radial section. The projected width of the fabric splice overlap band on the radial cross section. The width of the overlap between the two projections.

[0021] Preferably, the correction update in step S5 includes updating the sidewall adhesive bonding start angle of the next tire according to the following compensation formula. :

[0022] ;

[0023] in, and The first Article and No. The initial angle of the tire sidewall rubber adhesion. and The first The center angle of the tire sidewall joint and the center angle of the cord joint. The compensation coefficient is and satisfies .

[0024] Preferably, the connector identification unit includes a visual recognition device and / or a laser contouring device for identifying the connector boundary and determining... and .

[0025] Preferably, the center angle of the tire inner liner joint is... The center angle of the joint related to the tread or belt layer is And satisfy:

[0026] ;

[0027] in, For the joint avoidance angle threshold, The range is 60° to 180°.

[0028] Preferably, the specified inflation and settling conditions in step S5 include inflation to the rated pressure. Let it stand. ,in Rated air pressure, This refers to the settling time, and Hour.

[0029] Preferably, the fabric joint is an overlapping joint with an overlap length of [missing information]. The tire sidewall joint is a beveled lap joint with a bevel angle of 10°. Overlap length is ;in, The diameter is 5mm to 25mm. The angle is 10° to 45°. The diameter is 5mm to 30mm.

[0030] Secondly, the present invention also provides a tire prepared by the method described above, and the average sidewall indentation value is [not specified]. Not greater than 0.5 mm; among which, The indentation value was measured at the corresponding circumferential position of the overlapping reinforcement area for the same batch of tires. The arithmetic mean of the given values ​​satisfies:

[0031] ;

[0032] in, For sample size, For the first The indentation value of a tire. It is a positive integer.

[0033] Thirdly, the present invention also provides a tire forming and positioning system for implementing the method, comprising a tire forming drum, an angle acquisition unit, a joint identification unit, an actuator, and a controller; wherein,

[0034] The angle acquisition unit is used to obtain the real-time angle of the forming drum. ;

[0035] The connector identification unit is used to acquire and ;

[0036] The controller is used for calculation And output control commands;

[0037] The actuator is used to compensate for the rotation angle of the molding drum and / or the starting angle of the sidewall adhesive bonding, so that... and ;

[0038] in, This is the upper limit of the maximum overlap error. This is the minimum overlap threshold.

[0039] Fourthly, the present invention also provides a computer-readable storage medium having a computer program or instructions stored thereon, which, when executed by a processor, implement the steps of the method.

[0040] Fifthly, the present invention also provides a computer program product, including a computer program or instructions that, when executed by a processor, implement the steps of the method.

[0041] This invention significantly improves the shrinkage synergy and residual stress distribution during the vulcanization and cooling stage by overlapping the sidewall joint of the sidewall rubber with the ply joint of the carcass ply in the radial section (controlled circumferential overlap) during the tire forming process. This integrates two originally dispersed local "stiffness abrupt change points / stress concentration points" into a single "overlapping reinforcement zone". On the one hand, it avoids the formation of a "low-rigidity clamping zone" between the two joints in the traditional staggered arrangement, which would cause asymmetric traction shrinkage and reduce local indentation caused by uneven shrinkage. On the other hand, the thermal history of the overlapping reinforcement zone is more consistent, reducing the surface step deformation caused by differences in vulcanization degree and shrinkage near the joint. Ultimately, this makes the outer surface contour of the sidewall smoother and the indentation less noticeable to the naked eye. Based on the aforementioned process control, this invention can reliably improve appearance quality in mass production without changing the existing rubber compound formulation, increasing the overall thickness of the sidewall rubber, or introducing additional reinforcing components. Taking a 175 / 70R13 tire as an example, when using the traditional staggered joint process, the average sidewall indentation is about 0.7mm and the appearance pass rate is about 60.8%. However, after adopting the overlapping arrangement of this invention, the average sidewall indentation can be stably reduced to about 0.45mm (even down to about 0.34mm on the lower side), and the pass rate is significantly increased to about 87.62% to 95.23%. This significantly reduces the defect rate and the risk of rework and scrap, improves production consistency and appearance quality, and balances tire strength and cost control, demonstrating outstanding practical value and significance for industrialization. Attached Figure Description

[0042] Figure 1 This is a schematic cross-sectional view of the overlap between the vulcanized tire cord joint and the tire sidewall joint in an embodiment of the present invention.

[0043] Figure 2 This is a schematic cross-section of the normal area of ​​the tire cord joint after vulcanization, as shown in this embodiment of the invention.

[0044] Figure 3 : A schematic diagram of the dispersed arrangement of joints in the prior art.

[0045] Figure 4 : Schematic diagram of the overlapping arrangement of the joints in this invention. Detailed Implementation

[0046] To enable those skilled in the art to better understand and implement the present invention, the technical solution of the present invention will be further described in detail below with reference to the accompanying drawings. It should be understood that the following embodiments are for illustrative purposes only and are not intended to limit the scope of protection of the present invention. Equivalent substitutions or modifications made by those skilled in the art to the process parameters, apparatus forms, and detection methods of the present invention without departing from the concept of the present invention should all fall within the scope of protection of the present invention.

[0047] The core idea of ​​this invention is not to change the material formula or increase the thickness of the rubber compound, but to control the relative position of the "sidewall joint" and the "ply joint" during the tire forming stage, so that they form a repeatable, measurable and correctable overlapping reinforcement zone on the radial section of the tire. This significantly improves the shrinkage synergy and residual stress distribution of the sidewall area during the vulcanization and cooling stages, ultimately reducing the indentation depth of the outer surface of the sidewall and improving the appearance qualification rate.

[0048] I. Terminology Explanation

[0049] Sidewall joint: refers to the connection area formed by the circumferential overlap or butt joint of the sidewall rubber when it is attached to the green tire or tire carcass cord, which is usually manifested as a local thickness variation area.

[0050] Cord splice: refers to the connection area formed by the circumferential end overlap or butt joint when the cord layers of the tire carcass are cut and wound into a tube. It usually manifests as a local cord overlap / end structure change area.

[0051] Overlapping reinforcement zone: refers to the composite local structural area formed by the overlap (or near overlap) of the tire sidewall joint and the cord joint in the circumferential position of the tire and their projection overlap on the radial section of the tire.

[0052] Circumferential angular coordinates The angular position defined along the circumferential direction, starting from the circumferential reference mark of the forming drum or green tire, is used to quantify the joint position.

[0053] Target joint angle The center angle position of the desired overlap enhancement zone, which is preset or determined through process correction.

[0054] center corner of curtain joint : The center line of the curtain joint in the circumferential angular coordinates The corresponding angle position.

[0055] tire sidewall joint center angle : Circumferential angular coordinates of the centerline of the tire sidewall joint The corresponding angle position.

[0056] Circumferential coincidence error : Used to measure the angular deviation between the tire sidewall joint and the cord joint.

[0057] Maximum overlap error The upper limit of the allowable overlap error in the process, when If the limit is exceeded, corrections or rework are required.

[0058] Depression value Under specified inflation and static conditions, the maximum indentation depth (usually in mm) of the outer surface of the tire sidewall relative to the reference profile at the target detection circumferential position.

[0059] II. System Structure of the Invention (Process Implementation System / Apparatus Structure)

[0060] The method of this invention can be implemented on a conventional tire forming production line. In order to achieve controlled coincidence of "quantifiable positioning - executable adjustment - closed-loop correction", this embodiment provides a preferred system structure (not a limitation, and can also be achieved by manual alignment).

[0061] 2.1 Overall Structure of the Molding and Positioning System

[0062] The system includes at least the following units:

[0063] Tire forming drum unit: Used for winding the tire carcass ply and bonding the sidewall rubber, etc. The outer circumference of the forming drum is equipped with circumferential reference marks (such as mechanical markings, encoder zero points, photoelectric marks, etc.) to establish circumferential angular coordinates. .

[0064] Angle acquisition unit: preferably a rotary encoder, used to acquire the current circumferential angle of the forming drum in real time. The encoder resolution can be set according to the product grade, for example, 0.1° to 1°.

[0065] Connector identification unit: Used to identify the position of the center line of the plywood connector and the center line of the tire sidewall connector. Preferred methods include:

[0066] Visual recognition (camera + light source + edge / texture recognition) identifies the joint overlap boundary;

[0067] Laser displacement / contour scanning identifies local thickness abrupt changes;

[0068] The center angle of the joint is calculated from the station trigger signals during the bonding process (such as cutting length, bonding start angle, and overlap end angle).

[0069] Actuator unit: Used to compensate for the sidewall bonding initiation angle or the forming drum rotation angle. Typical components include:

[0070] Forming drum servo drive module (angle compensation);

[0071] Sidewall adhesive bonding head / pressure roller start and stop trigger module (start angle / end angle compensation).

[0072] Controller unit: Used to receive information from the angle acquisition unit and the connector identification unit, and to calculate... It also outputs control commands to the actuator unit to achieve overlap and correction.

[0073] Indentation detection and data management unit (optional but preferred): used to measure the sidewall appearance indentation of the vulcanized tire, generate statistical data and feed it back to the controller unit for updating the process parameters in step S5.

[0074] 2.2 How does this system correspond to the method in the claims?

[0075] Step S1 relies on "forming drum + angle acquisition unit + reference mark" to establish coordinates and ;

[0076] Steps S2 and S3 are respectively performed at the tire carcass cord winding and sidewall adhesive bonding stations to form joints and record the results. , ;

[0077] Step S4 calculates via controller And drive the actuator to complete "overlap control";

[0078] Step S5 uses the detection and data management unit to complete the dent measurement and correction update, enabling the process to be stably replicated in batches over a long period of time.

[0079] III. Specific Technical Route for Implementing the Method of the Invention

[0080] In conjunction with the attached diagrams, especially Figure 3 and Figure 4 As shown, the technical approach of this invention can be summarized as follows:

[0081] In traditional crafts ( Figure 3 In tire sidewalls, the cord fabric joints and tire sidewall joints are often misaligned to avoid stacking or due to work station habits. This results in two points of abrupt change in stiffness being dispersed, creating an area between them that is prone to asymmetric shrinkage, which eventually leads to a depression on the outer surface of the tire sidewall.

[0082] This invention ( Figure 4During the molding stage, the two joints are overlapped in a controlled manner in the circumferential position, so that the tire forms only a predictable reinforced zone during the vulcanization and cooling stages. The surrounding material shrinks and rebounds in a more symmetrical manner, reducing uneven residual stress and significantly improving the appearance of dents.

[0083] By using an angular coordinate system and a closed-loop correction mechanism, overlapping actions are not only "achievable," but also "measurable, controllable, and stably reproducible," making them suitable for mass production.

[0084] 3.1 Step S1: Establish circumferential angular coordinates and set the target joint angle

[0085] A circumferential reference mark is set on the tire forming drum, and the reference mark can be:

[0086] Mechanical markings and zero points on the molding drum;

[0087] Encoder zero point and photoelectric trigger point;

[0088] Fixed reference points for the bonding station (e.g., mechanical limit points at the starting position of the pressure roller).

[0089] Using this benchmark as Establish circumferential angular coordinates along the rotation direction of the forming drum. The range of values ​​is, for example .

[0090] Simultaneously set the target connector angle , is used to specify the center position of the overlapping reinforcement zone. The configuration methods include at least the following two:

[0091] Fixed setting method: When producing products of the same specifications and with the same process in a stable manner, Set to a fixed value, for example Or other locations that facilitate production organization and identification.

[0092] Dynamic setting method (preferred): Based on the dent detection data of the previous batch or cycle, and combined with the equipment drift situation, dynamically update This ensures that the overlapping reinforcement zone is stably located in the optimal position (e.g., avoiding joints of other layers or sensitive areas of local mold venting structures).

[0093] 3.2 Step S2: Form the fabric joint and ensure its center angle meets the following requirements.

[0094] After being cut, the carcass ply is wound onto a forming drum to form a carcass ply tube. The circumferential ends of the ply are overlapped or butted together to form ply joints. To ensure alignment with the sidewall joints later, the centerline of the ply joint must be aligned with the target angle during the ply winding stage. .

[0095] The implementation method of step S2 is as follows:

[0096] Method A (Tooling Alignment): A fabric mounting positioning block is set on the forming drum. When the edge of the fabric mounting aligns with the positioning block, the system automatically controls the cutting length within a fixed range, so that the center of the fabric overlap naturally falls on the positioning block. Nearby; simultaneously, by identifying the overlap boundary and calculating the center line of the fabric joint, the following is obtained. .

[0097] Method B (encoder + vision closed loop): After the fabric is laminated, the joint recognition unit identifies the joint boundary, and the controller calculates... ,like and If a deviation exists, it is compensated for by adjusting the starting angle of the next cord fabric to ensure the correct fit for the next tire. convergence to .

[0098] The fabric joint can be either an overlapping joint or a butt joint. An overlapping joint is preferred to balance strength and operational stability. The overlap length can be set to... The diameter is generally 5mm to 25mm, and the specific diameter can be determined based on the fabric material, the angle of the cord, and the manufacturing process.

[0099] 3.3 Step S3: Form the sidewall joint and obtain its center angle

[0100] The sidewall adhesive is attached to the outside of the tire carcass cord, and the circumferential ends of the sidewall adhesive overlap or butt-joint to form the sidewall joint. For subsequent overlap control, the center angle of the sidewall joint needs to be obtained. .

[0101] The implementation method of step S3 is as follows:

[0102] Method A (Calculation based on starting angle): The sidewall rubber is calculated based on the starting angle. Begin fitting, ending at the angle Once the overlap is complete, the center angle of the tire sidewall joint can be calculated based on the center of the overlap section. For example, the start and end angles of the overlap section are... and ,but

[0103] ,

[0104] in, The center angle of the tire sidewall joint; , The angles at the beginning and end of the sidewall overlap are all in degrees (°).

[0105] Method B (Visual / Contour Recognition): After bonding, the overlapping boundary and its center line are identified through visual recognition or contour scanning, and measured directly. .

[0106] The sidewall joint can use a beveled lap joint structure to mitigate the thickness jump. The bevel angle is denoted as... Generally, an overlap angle of 10° to 45° is acceptable; the overlap length is denoted as... Generally, a diameter of 5mm to 30mm can be used.

[0107] 3.4 Step S4: Control the overlap and constraint error of the tire sidewall joint and the cord fabric joint.

[0108] Step S4 is the key step in achieving "significantly reduced sidewall indentations and stable batch replication" in this invention. Its inventive contribution lies mainly in: for the first time, the joint position relationship between two different components is treated as a controllable process variable for unified constraint, forming a quantifiable overlap error index and an executable adjustment strategy, thereby upgrading "experience alignment" to "measurable closed-loop control". This step not only requires "overlap", but also the stability and repeatability of the overlap, while taking into account production cycle time and yield rate.

[0109] 3.4.1 Physical meaning of coincidence: circumferential coincidence, radial section projection coincidence

[0110] In actual tire structures, the sidewall rubber and the carcass ply are located in different layers, and their joints are not entirely on the same plane in space. The term "overlapping arrangement" as used in this invention is preferably understood as:

[0111] Circumferential position coincidence: center angle of tire sidewall joint Center angle of the curtain joint They are the same or approximately the same in the circumferential angular coordinate system;

[0112] Radial section projection coincidence: in the radial section of the tire (e.g. Figure 1 On the cross-section shown, the radial projections of the tire sidewall joint area and the cord joint area overlap, forming a "combined reinforcement zone".

[0113] This definition enables the invention to be manufacturable: even if there are slight axial offsets or structural differences between different layers, as long as their circumferential centerlines are consistent and their cross-sectional projections overlap, the stress concentration points can be integrated.

[0114] 3.4.2 Definition and Calculation of Overlap Error

[0115] To make coincidence control measurable, this invention defines circumferential coincidence error. :

[0116] ;

[0117] in: Circumferential coincidence error, in degrees (°); : Sidewall junction center angle, in degrees (°); : Center angle of the curtain joint, in degrees (°); Take the absolute value.

[0118] Further set the maximum overlap error In a preferred embodiment, take When the equipment has higher capabilities or higher requirements for appearance, it can be adopted. Or smaller. Those skilled in the art can select based on encoder resolution, fit repeatability, and product appearance requirements.

[0119] 3.4.3 Control Strategy 1: Achieving overlap through molding drum angle compensation

[0120] Before the sidewall adhesive is applied, the controller has already obtained the center angle of the cord fabric joint. If the goal is to make the center angle of the tire sidewall joint... and If the sides overlap, the forming drum can be rotated to a suitable angle before the sidewall bonding begins, so that the starting angle of the sidewall bonding and the center angle of the overlap section ultimately fall on the same point. .

[0121] In practice, the following strategies can be adopted:

[0122] 1) Preset the sidewall bonding process parameters (e.g., sidewall rubber length, overlap length) Angular span corresponding to the overlap area (etc.). The angular span of the overlap area can be calculated by converting the circumferential length of the tire sidewall rubber to the circumference of the molding drum. Those skilled in the art can use conventional conversion methods.

[0123] 2) Calculate the relationship between the center angle of the sidewall joint and the starting angle. For example, if the starting point of the sidewall adhesive bonding is... The offset angle between the overlap center and the starting point is ,but The corner of the tire sidewall adhesive is attached; The fixed offset angle between the center of the overlap and the corner of the joint is expressed in degrees (°).

[0124] 3) Order The target value is Then the starting angle should satisfy: Control the rotation of the forming drum so that the angle of the forming drum is equal to the above when the workstation triggers the application. This causes the center of the tire sidewall joint to fall on .

[0125] The advantage of this strategy is that it does not require changing the cut length of the tire sidewall rubber itself; overlap can be achieved simply by controlling the angle, making it suitable for production lines with a high degree of automation.

[0126] 3.4.4 Control Strategy Two: Achieving Overlap Through Sidewall Fitting Start Angle Compensation

[0127] On some production lines, the rotation rhythm of the forming drum is fixed, or the angle compensation of the forming drum is limited. In this case, overlap can be achieved by controlling the triggering time of the sidewall adhesive bonding head, that is, adjusting... .

[0128] The implementation method is as follows: the controller reads the encoder angle in real time. ,when Achieve the calculated The bonding head is triggered to press and adhere the tire sidewall adhesive. During the bonding process, conventional tension and pressure control ensure the stability of the bonding length and overlap, thereby guaranteeing… Stability, ultimately guaranteeing Stablize.

[0129] The advantages of this strategy are: minimal changes to the molding drum body and easy modification and upgrading of existing equipment; the disadvantages are: high requirements for the trigger delay and repeatability of the bonding head, therefore it is preferable to use a high-speed response solenoid valve / servo actuator.

[0130] 3.4.5 Control Strategy Three: Identification-Calculation-Correction

[0131] To address the issue of discrepancies between calculated and actual angles caused by adhesive slippage, bonding delays, and fabric tension fluctuations, this invention further optimizes the use of closed-loop control, the basic logic of which is as follows:

[0132] 1) Identify the actual center angle of the curtain joint (Instead of relying solely on process settings);

[0133] 2) Identify the actual center angle of the tire sidewall joint (Or identified after application);

[0134] 3) Calculation ;

[0135] 4) When At that time, corrective actions are performed.

[0136] Corrective actions should include at least one or more of the following:

[0137] Online compensation: Compensates for the starting angle of the next tire; the compensation amount can be... ,in For compensation coefficient, .

[0138] Re-applying / rework strategy: If the deviation can be identified during the tire production stage, rework can be carried out before entering the subsequent critical processes (e.g., re-applying the sidewall adhesive).

[0139] Alarm and isolation: When multiple tires show signs of malfunction... When the deviation exceeds the tolerance, the system will issue an alarm and isolate the batch to prevent it from being released due to poor appearance.

[0140] compensation coefficient The introduction of this feature gives the system an "asymptotic convergence" characteristic, avoiding the reverse deviation caused by overcompensation. Its calculation relationship can be written as:

[0141] ;

[0142] in, : No. The tire sidewall rubber is attached at the corner; : No. Center angle of the tire sidewall joint; : No. Center corner of tire cord fabric joint; : Compensation coefficient.

[0143] This closed-loop mechanism ensures that even with equipment drift, material batch differences, and operational fluctuations, the overlap relationship remains within a controlled range. This is an important guarantee that the present invention can stably reduce the average value of depressions in mass production.

[0144] 3.4.6 Coordination with other layer joints: Avoiding the risk of unevenness caused by "multiple joint stacking" (preferred limitation)

[0145] Although this invention advocates aligning the sidewall joint with the ply joint, to avoid excessive local mass concentration caused by the inner liner joint, tread joint, etc., also aligning simultaneously, this embodiment preferably introduces a "joint avoidance angle". This ensures that the joints of other layers maintain a sufficient angular distance from the overlapping reinforcement area, for example:

[0146] ;

[0147] in, : Center corner of the inner lining joint; : Center angle of the joint related to the tread or belt layer; The avoidance angle threshold is preferably 60° to 180°.

[0148] The technical effect of this limitation is that it retains the appearance improvement advantage of "two key joints overlapping" of the present invention, while avoiding the formation of excessive reinforcement points of "three or more joints overlapping", thus taking into account both uniformity and appearance quality.

[0149] In summary, step S4, through the combination of "angular coordinate quantization, error definition, execution compensation, (optional) closed-loop correction, and (optional) other layer avoidance", enables the present invention to move from principle to a manufacturable, reproducible, and statistically controllable industrial solution, and is one of the steps with the highest creative contribution of the present invention.

[0150] 3.5 Step S5: Sulfurization and Correction Update Based on Indentation Detection Results

[0151] The key function of step S5 is to verify the effect of "overlap control" with measurable indentation indicators and feed the results back to the process parameters, thus forming a long-term stable process capability. Unlike relying on a single setting, this step enables the invention to adapt to actual production fluctuations such as changes in mold thermal state, batch differences in rubber materials, and equipment wear and drift.

[0152] 5.5.1 Vulcanization process

[0153] The green tire, after the overlapping reinforcement zone has been controlled, is fed into a vulcanizing machine for vulcanization. The vulcanization conditions (temperature, pressure, time) can follow the standard process conditions for this tire specification; this invention does not require altering the vulcanization regime. After vulcanization, it is processed according to the standard cooling and production line procedures.

[0154] 5.5.2 Conditions and methods for dent detection (preferred)

[0155] To ensure comparability of dent data, standardized testing conditions should be preferred. For example, inflating tires to their rated pressure. Let stand at room temperature (For example, 24 hours) to allow the rubber rebound to stabilize; perform contour measurements at the corresponding circumferential positions in the overlapping reinforcement area to obtain the indentation value. .

[0156] Depression value The acquisition methods can be: contact displacement gauge scanning along the tire sidewall contour; non-contact laser profilometer or structured light scanning; visual measurement combined with calibration curves.

[0157] The statistical index for dents can be: dent value per tire. (Take the maximum indentation depth); average indentation value of the batch pass rate (The indentation value does not exceed the threshold) (proportion).

[0158] Wherein can be defined:

[0159] ;

[0160] in, : Check the number of tires; : No. Tire dent value; Average value of the depression.

[0161] 5.5.3 Corrective Update Mechanism

[0162] When the test shows that the improvement in the depression has not met expectations (e.g.) (Or the pass rate is insufficient), the following corrective update logic can be used:

[0163] 1) If If statistics show an out-of-range trend, then the priority should be given to adjusting the angle compensation strategy of S4 to achieve this. convergence;

[0164] 2) If Satisfied However, if the depression is still too large, then consider:

[0165] Joint identification errors can lead to "nominal overlap but insufficient overlap of actual cross-sectional projections," which can be resolved by improving the identification method or defining a "projection overlap criterion."

[0166] Sidewall angle or overlap length If the thickness step is too large due to deviation from the reasonable range, the joint geometry can be optimized without changing the formula.

[0167] If joints in other layers are too close together, causing localized mass concentration, the clearance angle can be increased. .

[0168] Corrective updates can be manifested as updates Update compensation coefficient ,renew Alternatively, the offset of the tire sidewall bonding starting angle may be updated. In this way, the present invention can consistently maintain a high appearance pass rate in industrial settings.

[0169] IV. Application Examples

[0170] 1) Experimental subjects and grouping principles

[0171] Test subjects: radial tires produced under the same formulation system, mold, and vulcanization regime.

[0172] Grouping:

[0173] Comparative example group: according to traditional process (corresponding) Figure 3 This causes the fabric joint and the tire sidewall joint to be circumferentially misaligned.

[0174] Example group: according to the process of the present invention (corresponding to) Figure 4 Control the circumferential overlap of the two joints and their radial section projection overlap (corresponding to) Figure 1 This forms a unified overlapping reinforcement zone.

[0175] 2) Key process variables (overlap error)

[0176] Establish circumferential angular coordinates using the circumferential reference mark of the forming drum. ,get:

[0177] Center corner of the curtain joint:

[0178] Sidewall joint center angle:

[0179] The circumferential coincidence error is defined as: in, The circumferential coincidence error is (°). The center angle of the tire sidewall joint (°); The center angle of the curtain joint (°).

[0180] Example group control ,in Provided in each example (usually taken as...) ).

[0181] 3) Indentation detection method

[0182] To ensure data comparability, all groups used the same testing conditions:

[0183] Inflate the tires to the rated pressure (Values ​​should be taken according to specifications, such as 220 kPa or 240 kPa). Room temperature. C Let it stand h. A laser profilometer / structured light scanner was used to perform a circumferential scan of the tire sidewall outer surface, and the indentation depth was extracted at the corresponding circumferential position of the joint. (mm), defined as the maximum indentation relative to the fitted reference profile at that location. The indentation on the upper sidewall of each tire is recorded separately. with the lower sidewall dent .

[0184] Statistical indicators:

[0185] 1) Average value: in, The average depression (mm) is the average depth. For sample size, For the first Tire dent value (mm).

[0186] 2) Defect judgment threshold: Deemed unacceptable. Examples are provided. (0.60mm is generally used for appearance control lines).

[0187] 3) Pass rate: in, For the pass rate, The quantity is acceptable.

[0188] V. Example 1

[0189] 1) Experimental Objective

[0190] Verification under mass production conditions was achieved by aligning the tire sidewall joint with the ply joint. Figure 4 ) relative to misalignment ( Figure 3 Can it significantly reduce dents and improve the appearance pass rate?

[0191] 2) Test conditions

[0192] Specifications: 175 / 70R13

[0193] Inflation pressure: kPa

[0194] Pass threshold: mm

[0195] Example group overlap control:

[0196] The formulation of other materials, the overlap length of the cord fabric, the oblique cutting overlap process of the tire sidewall, and the vulcanization system are all kept consistent.

[0197] 3) Grouping and Sample Size

[0198] Comparative Example 1 (misaligned arrangement, Figure 3 ):

[0199] Example 1 (overlapping arrangement) Figure 4 ):

[0200] 4) Results and Data

[0201] Table 1-1 Statistics of Upper Sidewall Dents

[0202]

[0203] Table 1-2 Statistics of lower sidewall indentations

[0204]

[0205] 5) Interpretation of Results (corresponding) Figures 1-4 (Mechanism verification)

[0206] In Comparative Example 1 ( Figure 3 In the process, the cord fabric joint and the sidewall joint are dispersed in the circumferential direction. After vulcanization and cooling, an area prone to asymmetric shrinkage is formed between the two "stiffness abrupt change points". The average value of the dent is about 0.73 to 0.75 mm, resulting in a high rate of appearance defects.

[0207] In Example 1 ( Figure 4 , Figure 1 In ), through control The two joints overlap in radial section projection to form a unified and overlapping reinforcement zone, significantly reducing the average indentation value to 0.45 / 0.34 mm and increasing the pass rate to 87.62%–95.23%. The improvement is more significant on the lower side, demonstrating the structure's ability to enhance the synergy between local residual stress and shrinkage.

[0208] VI. Example 2 (Specification 205 / 55R16)

[0209] 1) Experimental Objective

[0210] The effectiveness of the invention was verified under higher appearance standards, and the impact of the accuracy of the overlap error control on the effect was observed.

[0211] 2) Test conditions

[0212] Specifications: 205 / 55R16

[0213] kPa, h

[0214] Appearance control threshold: mm (more stringent)

[0215] Comparative Example 2: Staggered Arrangement ( Figure 3 ), Uncontrolled, usually in distributed

[0216] Example 2: Overlapping arrangement ( Figure 4 ),control (Stricter)

[0217] 3) Sample size

[0218] Comparative Example 2:

[0219] Example 2:

[0220] 4) Results Data

[0221] Table 2-1 Depression Statistics (205 / 55R16)

[0222]

[0223] To demonstrate the "realism of the experiment," Example 2 is provided as a supplementary example. Online sampling statistics (1 item is sampled for every 20 items, and a total of 6 items are sampled). They are respectively: All satisfy .

[0224] 5) Conclusion

[0225] At a stricter threshold Under the condition of mm, the present invention can still stably reduce the average value of the indentation to the range of 0.36 to 0.38 mm, thereby increasing the pass rate to 92.5% to 95.0%, which shows that the overlap control is not only effective, but also applicable to products with high appearance grade.

[0226] VII. Example 3 (Specification 195 / 65R15)

[0227] 1) Experimental Objective

[0228] When equipment angle drift exists in the production site (e.g., changes in the response delay of the bonding head, slight offset of the molding drum reference), the present invention can still maintain a stable effect through S5 correction.

[0229] 2) Experimental Design

[0230] Specifications: 195 / 65R15 kPa, h, mm

[0231] Set up two-stage production (60 lines per stage):

[0232] Phase A: Example 3A (overlap control but no correction update, only fixation) , )

[0233] Phase B: Example 3B (overlap control + correction update, based on sampled depressions and...) (Make corner compensation)

[0234] And set up Comparative Example 3 (misaligned arrangement) as a reference.

[0235] 3) Sample size

[0236] Comparative Example 3:

[0237] Example 3A:

[0238] Example 3B:

[0239] 4) Key process records (drift facts and corrective actions)

[0240] An increased delay in the bonding head triggering was observed at the end of stage A, leading to increased sampling delays. An upward trend has emerged (6 items sampled): (Exceeding) )

[0241] Phase B activates correction: Compensation formula (example) in, For the first Sidewall angle of the tire (°). The compensation coefficient is set to 0.7. The center angle of the tire sidewall joint (°). The center angle of the curtain joint (°).

[0242] Random inspection after correction (6 items): It has been brought back under control.

[0243] 5) Results Data

[0244] Table 3-1 Depression Statistics (195 / 65R15)

[0245]

[0246] 6) Conclusion

[0247] Even in the presence of equipment drift, the "overlap only, no correction" method still shows a significant improvement compared to the comparison model (average reduction to approximately 0.49–0.50 mm). After enabling S5 correction, The indentation has been reduced to 0.39–0.41 mm after the indentation has been further stabilized, and the pass rate has increased to 93.3%–95.0%.

[0248] VIII. Overall Conclusion

[0249] A comparison of three specifications, different thresholds, and different field fluctuation conditions yields the following results:

[0250] 1. This invention is achieved through... Figure 4 The "overlapping joint arrangement" shown generally reduces the average indentation value by about 0.20 to 0.40 mm and significantly improves the pass rate (commonly by 20% to 40%).

[0251] 2. In high appearance grade ( The fact that it can still maintain a significant advantage under (mm) indicates that the improvement is not accidental.

[0252] 3. Introducing S5 correction can resist equipment drift and maintain stability. The controlled and stable output of low-dimple products demonstrates industrial feasibility and replicability.

[0253] The foregoing description of embodiments of the present invention, through which those skilled in the art are able to implement or use the present invention, will be readily apparent to those skilled in the art. Various modifications to these embodiments will be readily apparent to those skilled in the art. The general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novelty disclosed herein.

[0254] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0255] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0256] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0257] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0258] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0259] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0260] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

Claims

1. A method for improving tire sidewall depression by superimposing a sidewall joint and a cord joint, characterized in that, Includes the following steps: S1, Establish circumferential angular coordinates on the tire forming drum. and set the target joint angle. ; S2, in the circumferential angular coordinates The carcass ply is wound to form a carcass ply tube, and the circumferential ends of the carcass ply are joined to form a ply joint, such that the angle position corresponding to the center line of the ply joint is . And control the alignment error of the curtain joint. Not greater than the curtain alignment threshold ; The angle position of the center line of the curtain joint. , S3, attach the sidewall adhesive to the outside of the tire carcass ply tube and join the circumferential ends of the sidewall adhesive to form a sidewall joint, so that the angle position corresponding to the center line of the sidewall joint is... , S4, The angle position of the center line of the tire sidewall joint; S5, The real-time angle of the molding drum is obtained based on the angle acquisition unit. and obtain based on the connector identification unit and The controller calculates the circumferential coincidence error. It also controls the actuator to compensate for the rotation angle of the forming drum and the starting angle of the sidewall adhesive bonding, so that... Not greater than the maximum overlap error Simultaneously, the overlap ratio of the sidewall joint overlap width and the cord joint overlap width projected onto the tire's radial cross-section is increased. Not less than the overlap threshold This creates overlapping reinforcement zones on the tire carcass. S5, the green tire forming the overlapping reinforcement zone is vulcanized, and the sidewall indentation value is measured after vulcanization under specified inflation and resting conditions. ,when Exceeding the indentation control threshold At that time, based on and For the next tire The initial angle of the sidewall adhesive bonding is corrected and updated.

2. The method according to claim 1, characterized in that: and ; And / or, ;in, Determine by the following formula: ； and satisfy ;in, The projected width of the tire sidewall joint overlap band on the radial section. The projected width of the fabric splice overlap band on the radial cross section. The width of the overlap between the projections of the two objects.

3. The method according to claim 1, characterized in that: Step S5 involves updating the sidewall rubber bonding start angle of the next tire according to the following compensation formula. : ； in, and The first Article and No. The initial angle of the tire sidewall rubber adhesion. and The first The center angle of the tire sidewall joint and the center angle of the cord joint. The compensation coefficient is and satisfies ; And / or, the specified inflation and settling conditions in step S5 include inflation to the rated pressure. Let it stand. ,in Rated air pressure, This refers to the settling time, and Hour.

4. The method according to claim 1, characterized in that: The connector identification unit includes a visual recognition device and / or a laser contouring device for identifying the connector boundary and determining... and .

5. The method according to claim 1, characterized in that: The center angle of the tire inner liner joint is The center angle of the joint related to the tread or belt layer is And satisfy: ； in, For the joint avoidance angle threshold, The range is 60° to 180°.

6. The method according to claim 1, characterized in that: The fabric joint is an overlapping joint with an overlap length of [missing information]. The tire sidewall joint is a beveled lap joint with a bevel angle of 10°. Overlap length is ;in, The diameter is 5mm to 25mm. The angle is 10° to 45°. The diameter is 5mm to 30mm.

7. A tire, characterized in that: Prepared by the method of any one of claims 1-6, and the average value of sidewall indentation Not greater than 0.5 mm; among which, The indentation value was measured at the corresponding circumferential position of the overlapping reinforcement area for the same batch of tires. The arithmetic mean of the given values ​​satisfies: ； in, For sample size, For the first The indentation value of a tire. It is a positive integer.

8. A tire forming and positioning system for implementing the method according to any one of claims 1-6, characterized in that, It includes a tire forming drum, an angle acquisition unit, a joint recognition unit, an actuator, and a controller; among which, The angle acquisition unit is used to obtain the real-time angle of the forming drum. ; The connector identification unit is used to acquire and ; The controller is used for calculation And output control commands; The actuator is used to compensate for the rotation angle of the molding drum and / or the starting angle of the sidewall adhesive bonding, so that... and ;in, This is the upper limit of the maximum overlap error. This is the minimum overlap threshold.

9. A computer-readable storage medium having a computer program or instructions stored thereon, characterized in that, When the computer program or instructions are executed by a processor, they implement the steps of the method according to any one of claims 1-6.

10. A computer program product, comprising a computer program or instructions, characterized in that, When the computer program or instructions are executed by a processor, they implement the steps of the method according to any one of claims 1-6.

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