Tile increasing type radial forming drum and tire secondary method forming process

Abstract

The invention discloses a tile increasing type radial forming drum and a tire secondary method forming process, and belongs to the technical field of tire forming equipment. The forming drum comprises a main shaft, a driving assembly and a tile block assembly, the tile block assembly comprises main tile blocks and secondary tile blocks which are alternately arranged at intervals in the circumferential direction of the main shaft, and concave-convex curved surface sliding guide structures which are always kept in sliding contact in the radial moving process are arranged on the adjacent side walls of the main tile blocks and the secondary tile blocks; the driving assembly comprises an inner sliding seat and an outer sliding seat which are respectively connected with the main tile block and the secondary tile block through a main connecting rod and a secondary connecting rod, and the inner sliding seat and the outer sliding seat are driven by the same driving source and do synchronous, same-direction and axial movement; the process comprises the steps of shrinkage preparation, material fitting, constant-speed swelling, secondary forming and demolding. The arc surface span is reduced by increasing the number of the tile blocks, and the concave-convex guide sliding structure and the layered synchronous driving are combined, so that the problem of non-uniform stretching of a tire body material is solved, and the tire forming quality and uniformity are improved.

Description

Technical Field

[0001] This invention relates to the field of tire forming equipment technology, and more specifically, to a radial forming drum with added bearings and a secondary tire forming process. Background Technology

[0002] The two-stage tire forming process is a classic method that divides tire forming into two stages. The second stage, performed on a radial forming drum, involves processes such as half-part bonding, reverse wrapping, rolling, and wire bead fastening. Existing radial forming drums typically employ a combination structure of a main shaft, drive assembly, and bearing assembly. The drive assembly drives the radial expansion and contraction of the bearings to achieve tire carcass forming and demolding. However, current technologies generally use 6+6 or 8+8 bearing configurations, resulting in excessively large arc spans for individual bearings. This leads to inconsistent stretching of the tire carcass material at different locations during radial expansion, easily causing defects such as exposed inner liner yarns and ply misalignment.

[0003] To address the aforementioned issues, the industry has implemented various technological improvements. For example, utility model patent CN202021563710.2 discloses a tire forming drum and a radial telescopic tire shaping drum, employing a structure where main and secondary tires are arranged in a staggered pattern to solve the problem of air bubble residue during tire carcass bonding. Invention patent application CN103831985A discloses a giant engineering tire forming drum, using a combination of wide and narrow drum tiles and a narrow drum shoulder with inclined contraction to avoid tangential compression of the tire blank by the drum shoulder. However, these solutions still suffer from limitations such as a limited number of tire tiles, large splicing gaps, and insufficient precision in synchronous driving of multiple tire tiles, leading to uneven stretching of the tire carcass material and excessive drum surface runout, affecting the uniformity and durability of the finished tire.

[0004] Therefore, there is an urgent need for a radial forming drum with added bearings that can solve the problem of uniform stretching of tire carcass materials, eliminate gaps in drum splicing, and improve the synchronous driving accuracy of multi-bearing blocks, as well as a corresponding secondary tire forming process, in order to overcome the above-mentioned defects of the existing technology. Summary of the Invention

[0005] In order to overcome the above-mentioned defects of the prior art, the present invention provides a radial forming drum with added bearings and a secondary tire forming process to solve the problems mentioned in the background art.

[0006] In a first aspect, embodiments of this application provide a radial forming drum with added tiles, characterized in that it includes: a main shaft, a drive assembly, and a tile assembly; The drive assembly includes an inner slide and an outer slide that are coaxially mounted on the spindle; The main tile is connected to the inner slide block via the main connecting rod; The secondary tile block is connected to the outer slide block via the secondary connecting rod; The inner and outer slides are driven by the same drive source and move synchronously and in the same direction axially to drive the main and secondary tiles to expand and contract radially synchronously. The tile assembly includes main tiles and secondary tiles arranged alternately at intervals along the main axis circumferentially; The number of main tiles ranges from 9 to 27, and the number of secondary tiles is the same as that of the main tiles; The total number of main tiles and secondary tiles is 18-54, and the central angle of the arc surface of a single tile is ≤20°; The adjacent sidewalls of the main tile and the secondary tile are provided with a concave-convex curved surface guide structure that maintains sliding contact during radial movement.

[0007] In some embodiments of this application, the concave-convex curved surface guide structure includes a convex arc surface and a concave arc surface; The convex arc surface is set on the side wall of the main tile; The concave arc surface is set on the side wall of the secondary tile; The radii of curvature of the convex and concave arc surfaces are equal, and the fit gap between them during radial movement of the tile is ≤0.1mm.

[0008] In some embodiments of this application, the driving source is a hydraulic drive cylinder or a servo electric cylinder; A displacement difference compensation mechanism is provided between the inner slide and the outer slide; The displacement difference compensation mechanism is used to monitor and adjust the axial displacement difference between the inner and outer slide blocks, so that the radial height difference between the main and secondary slide blocks is ≤0.05mm.

[0009] In some embodiments of this application, the main connecting rod and the secondary connecting rod are of equal length; and the outer surfaces of the main tile and the secondary tile are covered with an elastic buffer layer; The thickness of the elastic buffer layer is 0.5-1.2 mm, and the surface roughness Ra≤0.6 μm.

[0010] In some embodiments of this application, the mating surfaces of the concave-convex curved guide structure are provided with a wear-resistant coating, and the main tile and the secondary tile are made of high-strength aluminum alloy or alloy steel.

[0011] In some embodiments of this application, the number of primary and secondary tire bearings is adjustable according to tire specifications, wherein: When used in passenger car tires, the total number of primary and secondary tires is 24, and the central angle of each tire is 15°. When used for heavy-duty tires, the total number of main and secondary tires is 36, and the central angle of each tire is 10°. When used in engineering applications, the total number of main tiles and secondary tiles is 48, and the central angle of each tile is 7.5°.

[0012] Secondly, embodiments of this application provide a tire secondary forming process, characterized by including the following steps: S1. Driven by the drive assembly, the main and secondary tire pads shrink synchronously in the radial direction, reducing the radial dimension of the drum surface to 75%-82% of the inner diameter of the target tire. S2. Apply the tire material to the shrunken drum surface; S3. Drive the main and secondary tires to expand radially at a speed of 3-12 mm / s using the drive assembly until the drum surface reaches the preset tire inner diameter. During the drum expansion process, the radial height difference between any adjacent main and secondary tires is ≤0.05 mm. S4. Under stable drum surface conditions, bonding, reverse wrapping and rolling are carried out stably to ensure the symmetrical and firmness of each half of the component and the retaining ring, improve tire uniformity and strength, and at the same time complete the precise bonding process of the tire carcass and tread composite components. S5. Drive the main tile and secondary tile to shrink synchronously in the radial direction through the drive component, so that the molded body separates from the drum surface and completes demolding.

[0013] In some embodiments of this application, the tire material in S2 is continuously supported and bonded to the drum surface at multiple points, and the initial bonding flatness error is ≤0.3mm.

[0014] In some embodiments of this application, the inflation speed during the inflation process is gradient-controlled according to the tire specifications, specifically as follows: The bulge speed of passenger car tires is 10-12 mm / s; The inflation speed of a heavy-duty tire is 8-10 mm / s; The inflation speed of engineering tires is 3-5 mm / s.

[0015] In some embodiments of this application, the stretching error of the tire material at various locations during the expansion process is 0.5%–0.8%.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention increases the total number of main and secondary tiles to 18-54 and controls the central angle of the arc surface of a single tile to within 20°, making the micro-element stretching ratio of the tire material at each position tend to be consistent during the radial expansion process, with a stretching error of ≤0.8%. This fundamentally eliminates the defects of exposed inner lining and bent cord caused by excessive arc surface span of the tile, and significantly improves the uniformity of tire molding and the isotropic mechanical properties of the material.

[0017] 2. This invention features a concave-convex curved guide structure on the adjacent sidewalls of the main and secondary tiles, ensuring a seamless fit with a clearance of ≤0.1mm during radial movement. This eliminates the localized material suspension or compression caused by gaps in traditional tiles, achieving continuous and uniform support of the drum surface for the tire material. This effectively avoids wrinkling and stress concentration issues caused by discontinuous support. 3. The present invention adopts a synchronous control scheme in which the inner and outer slides are driven in layers and driven by the same drive source. With the help of the displacement difference compensation mechanism, the radial height difference between the main and secondary slides is controlled within 0.05mm, which solves the technical problem of insufficient synchronous expansion and contraction accuracy of multi-slide structure, and makes the drum surface out-of-roundness ≤0.1mm, which significantly improves the dynamic balance performance and durability of the finished tire. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0019] Figure 1 This is a flowchart of the overall process for the secondary tire molding method provided by the present invention; Figure 2 This is a schematic diagram of the axial structure of the radial forming drum with added tiles provided by the present invention; Figure 3 This is a schematic diagram of the expansion drum process control provided by the present invention; Figure 4 A comparison chart of process parameters for different tire specifications provided for this invention. Detailed Implementation

[0020] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] To enable those skilled in the art to better understand the present application, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] Example 1 Please see Figure 1 This invention provides a secondary tire forming process, which is based on a radial forming drum with added bearings. Figure 1The overall flow chart of the tire secondary molding process of the present invention is shown. The entire process includes five core steps: shrinkage preparation stage S1, material bonding stage S2, uniform expansion stage S3, secondary molding stage S4, and demolding and shrinking stage S5. The following is in conjunction with... Figure 1 Each step is explained in detail.

[0023] Step S1: Contraction Preparation Phase This step aims to adjust the radial dimension of the forming drum to a suitable shrinkage state for bonding the tire carcass material. Specifically, the main and secondary tire blocks are driven to shrink synchronously radially by a drive assembly, reducing the radial dimension of the drum to 75%–82% of the target tire's inner diameter. This shrinkage ratio is the result of extensive experimental optimization: if the shrinkage ratio is too large (i.e., insufficient drum shrinkage), the gap between the drum and the material will be too small during subsequent bonding, hindering the smooth laying of the material and easily causing wrinkles; if the shrinkage ratio is too small (i.e., excessive drum shrinkage), the gap between the tire blocks may increase, and the drum's support rigidity will decrease, potentially causing deformation of the drum during bonding. Controlling the shrinkage ratio within the range of 75%–82% provides sufficient operating space for material bonding while ensuring that the drum surface has sufficient support rigidity and a uniform support surface.

[0024] During the shrinkage process, the alternating arrangement of main and secondary bearings, connected to the inner and outer slides via independent connecting rods, allows for synchronized shrinkage of all bearings. The drive assembly is powered by a single source (such as a hydraulic cylinder or servo cylinder), driving the inner and outer slides to move synchronously and in the same direction along the main shaft axis via a transmission key. This axial motion is then converted into radial shrinkage of the bearings via the main and secondary connecting rods. This drive method ensures consistent displacement of all bearings during shrinkage, preventing drum surface deformation or jamming caused by asynchronous bearing movements.

[0025] Step S2: Material bonding stage After the drumhead shrinks to the predetermined size, the tire carcass material is bonded. Operators or automated bonding devices bond the tire carcass ply, support adhesive, sidewall adhesive, and other materials layer by layer onto the drumhead according to process requirements. Because the molding drum of this invention employs a high-density tile design (the total number of main and secondary tiles is 18-54, with a central angle of the arc surface of each tile ≤20°), the drumhead is composed of numerous small arc-shaped tiles, forming a multi-point continuously supported surface. Compared to traditional structures with fewer tiles (such as 6+6), this high-density tile structure results in more and more uniform contact points between the material and the drumhead, and the initial bonding flatness error can be controlled within 0.3mm. During the material bonding process, there are no large gaps between the drumhead sections, so the material will not be suspended or locally compressed at these gaps, laying a good foundation for the subsequent drum expansion process.

[0026] In addition, the outer surface of the tile is covered with an elastic cushioning layer made of polyurethane or other high-molecular elastic materials, with a thickness of 0.5-1.2 mm and a surface roughness Ra≤0.6 μm. The functions of the elastic cushioning layer include: increasing the friction between the tile and the material to prevent the material from sliding during the bonding process; cushioning the local pressure of the tile on the material to avoid indentations on the material surface; and its smooth surface helps the material to adhere evenly and reduces the formation of air bubbles.

[0027] Step S3: Uniform expansion stage After the materials are bonded, a drum expansion operation is required to radially expand the drumhead to the inner diameter of the target tire carcass. The key to this step is controlling the expansion speed and synchronization accuracy. The main and secondary tire bearings are driven by a drive assembly to expand radially at a synchronous and uniform speed of 3–12 mm / s until the drumhead reaches the preset inner diameter of the tire carcass. The selection of the expansion speed depends on the tire specifications: passenger car tires can use a faster speed (e.g., 10–12 mm / s) to improve production efficiency; engineering tires, due to their multiple layers and greater thickness, require a slower speed (e.g., 3–5 mm / s) to ensure uniform material stretching.

[0028] During the drum expansion process, a displacement difference compensation mechanism is installed between the inner and outer slide blocks. This mechanism monitors the axial displacement difference between the inner and outer slide blocks in real time and adjusts the output of the drive source through a proportional valve or servo controller to keep the radial height difference between the main and secondary drum blocks within 0.05mm. This high-precision synchronous control ensures that the drum surface maintains good cylindricity during the expansion process, avoiding localized excessive stretching or wrinkling of the material due to inconsistent drum block heights.

[0029] Due to the large number of tiles and the small span of the arc surface, the stretching of the tire material at various locations tends to be uniform during the expansion process. Experimental data shows that, using the process of this invention, the stretching error of the tire material at various locations during the expansion process can be controlled within 0.5%-0.8%, which is far superior to the 3%-5% of the traditional process. This fundamentally solves the defects such as exposed inner lining threads and bent cords caused by uneven stretching.

[0030] Step S4: Secondary molding stage Once the drumhead reaches and stabilizes at the target inner diameter, the crucial secondary forming process begins. While maintaining radial dimensional stability, the processes of half-part bonding, reverse wrapping, rolling, and wire ring fastening are completed sequentially. Because the drumhead is composed of high-density tiles, and the tiles are seamlessly bonded through a concave-convex curved guide structure, the drumhead will not experience radial movement or localized deformation when subjected to various operating forces (such as roller pressure and reverse wrapping force). Simultaneously, the concave-convex curved guide structure maintains sliding contact throughout the radial movement of the tiles, ensuring the drumhead retains overall rigidity under load, thereby guaranteeing the uniformity of the tire sidewall reverse wrapping and the accurate positioning of the wire ring fastening.

[0031] Step S5: Demolding and drum-forming stage After the molding process is completed, the molded body needs to be removed from the molding drum. The main and secondary tiles are driven by a drive assembly to shrink synchronously radially, separating the molded body from the drum surface. During shrinkage, the concave-convex curved guide structure plays a crucial role again: it guides the tiles to retract precisely radially, preventing the tiles from clamping or scratching the inner wall of the molded body during shrinkage. Simultaneously, because the tile surface is covered with an elastic buffer layer, the peeling force between the molded body material and the drum surface is small during demolding, preventing damage to the molded body. Once the tiles have fully shrunk, the molded body can be demolded and sent to the subsequent vulcanization process, completing the entire two-stage molding process using the secondary method.

[0032] In summary, the tire secondary molding process provided in this embodiment, by precisely controlling the parameters and operations of the five steps and combining the structural advantages of the high-density tile forming drum, achieves high uniformity molding of tire carcass materials, significantly improving the quality and production efficiency of finished tires.

[0033] Example 2 Please see Figure 2 The present invention provides a radial forming drum with added bearings, which is the core equipment for realizing the above-mentioned secondary tire forming process. Figure 2 A schematic diagram of the axial structure of the forming drum is shown, mainly consisting of three parts: the main shaft, the drive assembly, and the tile assembly. The following section will combine... Figure 2 Each component is described in detail.

[0034] spindle The main shaft serves as the supporting foundation for the entire forming drum. It features a hollow cylindrical structure with an internal power transmission channel to house hydraulic lines, electrical wires, and other components. Both ends of the main shaft are mounted on the forming machine via bearing seats and can be fixed or rotated relative to the frame. The main shaft is typically made of high-strength alloy steel, which undergoes quenching and tempering and precision machining to ensure sufficient rigidity and dimensional stability.

[0035] Driver components The drive assembly is coaxially mounted on the spindle and includes an inner slide, an outer slide, a drive source, and a transmission key. Both the inner and outer slides are annular sleeve structures that can slide along the spindle axis. The drive source is preferably a hydraulic cylinder or a servo electric cylinder, mounted at one end of the spindle and connected to the inner and outer slides via the transmission key. When the drive source operates, the axial movement of its piston rod is simultaneously transmitted to both the inner and outer slides via the transmission key, driving them to move synchronously and in the same direction along the spindle axis. This "co-drive" design ensures that the displacements of the inner and outer slides are always consistent, fundamentally avoiding misalignment of the bearing action caused by asynchronous movement of the two slides.

[0036] tile components The tile assembly consists of main tiles and secondary tiles, which are arranged alternately along the main axis circumferentially. The number of main tiles ranges from 9 to 27, and the number of secondary tiles is the same as that of the main tiles, resulting in a total of 18 to 54 main and secondary tiles. The central angle of the arc surface of each tile is ≤20°, meaning that the arc span of the tile is very small, and the drum surface is composed of a large number of small arc-shaped tiles. This high-density tile design has the following advantages: The radial expansion stroke of a single tile is reduced, so that the force on the body material is uniform at all positions during the expansion process; The drum surface has been given more support points for the tire material, preventing the material from being suspended in the gaps between the tiles; It improves the circumferential rigidity of the drumhead, making it less prone to deformation when subjected to external loads.

[0037] The main bearing pad is hinged to the inner slide block via a main connecting rod, and the secondary bearing pad is hinged to the outer slide block via a secondary connecting rod. Both the main and secondary connecting rods are of equal length and are made of high-strength materials to ensure transmission accuracy and durability. When the inner and outer slide blocks move axially, the linkage mechanism converts the axial motion into radial motion of the bearing pads, thereby achieving synchronous expansion and contraction of the bearing pads.

[0038] Concave-convex curved surface guide structure A concave-convex curved surface guide structure is provided on the adjacent sidewalls of the main tile and the secondary tile. This structure is one of the important innovations of this invention. Specifically, the sidewall of the main tile has a convex arc surface, and the sidewall of the secondary tile has a concave arc surface. The radii of curvature of the convex and concave arc surfaces are equal, and the fit clearance between them during radial movement of the tiles is ≤0.1mm. This design has the following functions: During the radial movement of the tile, the convex arc surface and the concave arc surface always maintain sliding contact, forming continuous guidance to prevent the tile from moving circumferentially or axially. Because of the extremely small gap between the tiles, the joints between the tiles remain "seamless" during the dynamic process, preventing the material from being squeezed or embedded at the joints. The interplay of concave and convex curved surfaces increases the overall rigidity of the tile assembly, resulting in less deformation of the drum surface when subjected to load.

[0039] The mating surfaces of the concave-convex curved guide structure can be coated with wear-resistant coatings, such as diamond-like carbon coatings or ceramic coatings, to extend service life. Meanwhile, the main and secondary tiles can be made of high-strength aluminum alloy or alloy steel, ensuring strength while reducing weight.

[0040] elastic buffer layer The main and secondary tiles are covered with an elastic buffer layer made of polyurethane, rubber, or other high-molecular elastic materials, with a thickness of 0.5–1.2 mm and a surface roughness Ra ≤ 0.6 μm. The elastic buffer layer serves multiple purposes: first, it increases the friction between the tile and the substrate material, preventing slippage during bonding; second, it cushions localized pressure from the tile on the material, preventing indentations; and third, it provides a certain degree of elastic deformation, allowing the tile surface to better conform to the material and reducing air bubbles.

[0041] Displacement difference compensation mechanism To further improve the accuracy of synchronous expansion and contraction of the drum blocks, a displacement difference compensation mechanism is installed between the inner and outer slide blocks. This mechanism includes a displacement sensor (such as a magnetostrictive displacement sensor) and a proportional control valve. The displacement sensor monitors the axial position of the inner and outer slide blocks in real time and feeds the signal back to the controller. The controller adjusts the output of the drive source according to the displacement difference signal, ensuring that the displacement difference between the inner and outer slide blocks is always zero, thereby ensuring that the radial height difference between the main and secondary drum blocks is ≤0.05mm. This closed-loop control method effectively eliminates synchronization deviations caused by manufacturing errors, frictional resistance, and other factors, ensuring the high cylindricity of the drum surface.

[0042] In summary, the radial forming drum with added tiles provided in this embodiment achieves high precision, high rigidity, and high uniformity forming capabilities through high-density tile design, concave-convex curved surface guide structure, layered homogeneous drive, and displacement difference compensation control, providing a reliable hardware foundation for the secondary tire forming process.

[0043] Example 3 Please see Figure 3 The present invention further provides a method for controlling the expansion process, which involves... Figure 3 The control principle diagram shown achieves high-precision synchronous drum expansion. Figure 3 The logical relationship between the drive system, displacement difference compensation mechanism, and radial height difference control is illustrated below. Figure 3 The control of the expansion process is explained in detail.

[0044] drive system The drive system comprises a single drive source (hydraulic cylinder or servo electric cylinder), an inner slide, and an outer slide. The output of the drive source is connected to both the inner and outer slides via a transmission key, thus the axial movement of the inner and outer slides is driven by the same power source. This design avoids synchronization errors that may occur when using two independent drives. The speed and position of the drive source are precisely controlled by a controller to achieve uniform adjustment of the drum speed and accurate positioning of the final position.

[0045] Displacement difference compensation mechanism The displacement difference compensation mechanism is crucial for ensuring the radial height difference between the primary and secondary slide blocks. This mechanism includes a displacement sensor and a controller. The displacement sensor is installed at appropriate positions on the inner and outer slide blocks to detect their axial displacement values ​​in real time and calculate the displacement difference ΔS. The controller receives the ΔS signal and compares it to a target value (zero). If ΔS exceeds the allowable threshold, the controller adjusts the output of the drive source via a proportional valve or servo drive, such as fine-tuning the flow rate of the hydraulic cylinder or the rotational speed of the servo electric cylinder, to bring the displacements of the inner and outer slide blocks back to uniformity.

[0046] The displacement difference compensation mechanism plays a role not only in static correction, but more importantly in real-time response during dynamic processes. Because the tiles may be subjected to uneven frictional resistance or inertial forces during expansion and contraction, there may be slight differences in the instantaneous speed of the inner and outer slides. The displacement difference compensation mechanism can detect and correct these differences in a timely manner, ensuring that the radial height difference between the main tile and the secondary tile is always ≤0.05mm throughout the entire expansion process.

[0047] Radial height difference control The radial height difference between the main and secondary tiles is a direct indicator of the cylindricity of the drum surface. Figure 3 In this system, the radial positions of the main and secondary tiles are determined by the swing angles of the main and secondary connecting rods, respectively, while the swing angles of the connecting rods are determined by the axial positions of the inner and outer slides. Therefore, by controlling the difference in axial displacement between the inner and outer slides, the radial height difference of the tiles can be indirectly controlled.

[0048] In actual control, the controller not only receives displacement difference signals but also feedback signals from drum surface position sensors (such as laser rangefinders) to directly measure the radial height of the main and secondary tiles. These sensors are installed around the forming drum to detect the radial dimensions of various points on the drum surface in real time. The controller compares the measured values ​​with the target values ​​and makes fine adjustments through the displacement difference compensation mechanism to ensure that the cylindricity error of the drum surface is within the allowable range.

[0049] Control strategy The drum expansion process control of this invention adopts a "feedforward + feedback" composite control strategy. Feedforward control calculates the theoretical displacement trajectories of the inner and outer slides based on a preset drum expansion speed curve and the kinematic model of the tile, serving as the control command for the drive source. Feedback control then corrects the drive command based on real-time data from displacement and position sensors, compensating for various interference factors.

[0050] Regarding the drum expansion speed, the controller can achieve stepless speed adjustment within the range of 3-12 mm / s and automatically select the appropriate speed gear according to the tire specifications. For example, for passenger car tires, a high-speed drum expansion of 10-12 mm / s is used to improve production efficiency; for truck tires, a medium-speed drum expansion of 8-10 mm / s is used to balance efficiency and quality; and for engineering tires, a low-speed drum expansion of 3-5 mm / s is used to ensure that the material is fully stretched and evenly distributed.

[0051] Security Protection The control system also has safety protection functions. When the difference between the inner and outer sliding seats is detected to exceed 0.1mm, the system will issue an alarm and automatically pause the drum expansion operation, and continue to execute after the deviation is eliminated; when an abnormal radial dimension is detected at a point on the drum surface (such as exceeding the target value ±0.2mm), the system will immediately stop the drive source and prompt the operator to check the equipment or materials.

[0052] In summary, the inflation process control method provided in this embodiment achieves high-precision and high-stability synchronous inflation through precision sensors, closed-loop control, and intelligent algorithms, ensuring the uniformity and consistency of tire body forming.

[0053] Example 4 Please see Figure 4 The tire secondary molding process and molding drum provided by this invention can be applied to the production of tires of various specifications. Figure 4 The process parameters and application effects of three typical tire specifications (passenger car tires, truck tires, and engineering tires) are presented in the form of comparison charts. The following section combines... Figure 4 The application of each specification is explained in detail.

[0054] Passenger car tire application examples For passenger car tires (such as 205 / 55R16), the total number of primary and secondary tire blocks is set to 24 (12 each), with a central angle of 15° for each block. The inflation speed is controlled within the range of 10-12 mm / s. During the molding process, due to the appropriate number of tire blocks, the bulge surface has sufficient smoothness and support density, and the flatness error of the tire carcass material can be controlled within 0.2 mm. After inflation, the tensile error of the tire carcass material at various locations is 0.5%-0.8%, the cord offset is ≤0.3 mm, and the uniformity of the support rubber distribution is improved by more than 35%. The quality of the molded tire blank is stable, and the finished tire produced by subsequent vulcanization has excellent dynamic balance performance and good high-speed driving stability.

[0055] Passenger car tire production is characterized by large batch sizes and fast cycle times. This process optimizes the number of tire treads and the inflation speed, achieving high-efficiency production while ensuring quality. Actual testing shows that after adopting this process, the first-pass yield of passenger car tires increased to over 98.5%, the exposed thread defect rate in the inner liner was reduced by 80%, and production costs were effectively lowered.

[0056] Application examples of heavy-duty tires For heavy-duty tires (such as 12.00R20), the total number of main and secondary tires is set to 36 (18 each), with a central angle of 10° for each tire. The expansion speed is controlled within the range of 8-10 mm / s. Heavy-duty tires have a thicker body and more material layers, requiring higher uniformity in molding. Increasing the number of tires to 36 further reduces the arc span of a single tire, resulting in more uniform stretching of the material during expansion. Simultaneously, the slower expansion speed helps the material fully relax and release stress, avoiding localized hardening caused by rapid stretching.

[0057] After molding, the offset of the ply of the heavy-duty tire is ≤0.4mm, and the uniformity of the support rubber distribution is improved by more than 30%. Due to the effect of the concave-convex curved surface guide structure, the tire blocks can still maintain a seamless fit when bearing heavy tire carcass materials, and the drum surface is not deformed. Durability tests of finished tires show that the average mileage of heavy-duty tires produced using this process is increased by 12%, and the shoulder delamination failure rate is significantly reduced.

[0058] Application examples of engineering tires For engineering tires (such as 29.5R29 specification), the total number of main and secondary tires is set to 48 (24 each), with a central angle of 7.5° for each tire. The expansion speed is controlled within the range of 3-5 mm / s. Engineering tires are large, heavy, and thick, making molding extremely difficult. Increasing the number of tires to 48 makes the drum surface almost a continuous curved surface, eliminating any gaps or compression during material bonding. During the expansion process, due to the extremely slow speed, the material has sufficient time to flow and adjust, and the stretching error can be controlled within 0.5%. The displacement difference compensation mechanism ensures that the radial height difference of all tires is ≤0.05 mm, and the drum surface out-of-roundness is ≤0.1 mm, guaranteeing molding accuracy even for giant engineering tires.

[0059] Taking a 29.5R29 engineering tire as an example, after adopting this process, the cord offset is ≤0.5mm, the uniformity of the support rubber distribution is improved by 40%, and the exposed thread defect in the inner liner is completely eliminated. The formed tire blank has a regular shape, providing a good foundation for subsequent vulcanization. Actual vehicle tests show that the tire's cut resistance and wear resistance are superior to tires produced by traditional processes.

[0060] Parameter selection criteria Figure 4 The parameters given, such as the number of tire tiles, central angle, and drum expansion speed, are optimal combinations derived from extensive experiments and theoretical analysis. The selection of the number of tire tiles follows the principle that "the larger the tire diameter and the more material layers, the more tire tiles should be," to ensure sufficient support density of the material from the drum surface. The central angle is inversely proportional to the number of tire tiles; the more tire tiles, the smaller the central angle, the smaller the arc span of a single tire tile, and the better the uniformity of material stretching. The selection of the drum expansion speed comprehensively considers material properties and production efficiency: thicker materials require slower speeds to ensure uniform stretching, while thinner materials can use faster speeds to improve efficiency.

[0061] In conclusion, the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A radially formed drum with added tiles, characterized in that, include: Spindle, drive assembly, and bearing assembly; The drive assembly includes an inner slide and an outer slide coaxially sleeved on the main shaft; The inner slide and the outer slide are driven by the same drive source and move synchronously and in the same direction axially to drive the main tile and the secondary tile to expand and contract synchronously radially. The tile assembly includes main tiles and secondary tiles arranged alternately at intervals along the main axis circumferentially; The main tile is connected to the inner slide block via a main connecting rod; The secondary tile is connected to the outer slide block via a secondary connecting rod; The number of main tiles is 9-27, and the number of secondary tiles is the same as that of the main tiles; The total number of main tiles and secondary tiles is 18-54, and the central angle of the arc surface of a single tile is ≤20°; The adjacent sidewalls of the main tile and the secondary tile are provided with a concave-convex curved surface guide structure that maintains sliding contact during radial movement.

2. The radially forming drum of the type of tile-forming method according to claim 1, characterized in that, The concave-convex curved surface guide structure includes a convex arc surface and a concave arc surface; The convex arc surface is provided on the side wall of the main tile; The concave arc surface is provided on the side wall of the secondary tile; The radii of curvature of the convex and concave arc surfaces are equal, and the fit gap between them during radial movement of the tile is ≤0.1mm.

3. The radially forming drum of the type according to claim 1, characterized in that, The drive source is a hydraulic drive cylinder or a servo electric cylinder; A displacement difference compensation mechanism is provided between the inner slide block and the outer slide block; The displacement difference compensation mechanism is used to monitor and adjust the axial displacement difference between the inner slide and the outer slide, so that the radial height difference between the main slide and the secondary slide is ≤0.05mm.

4. The radially forming drum of the type according to claim 1, characterized in that, The main connecting rod and the secondary connecting rod are of equal length; and the outer surfaces of the main tile and the secondary tile are covered with an elastic buffer layer. The thickness of the elastic buffer layer is 0.5-1.2 mm, and the surface roughness Ra ≤ 0.6 μm.

5. A radially forming drum with added tiles according to claim 1, characterized in that, The mating surfaces of the concave-convex curved guide structure are coated with a wear-resistant coating, and the main tile and the secondary tile are made of high-strength aluminum alloy or alloy steel.

6. The radially forming drum of the type according to claim 1, characterized in that, The number of main and secondary tire bearings is adjustable according to tire specifications, wherein: When used in passenger car tires, the total number of primary and secondary tires is 24, and the central angle of each tire is 15°. When used for heavy-duty tires, the total number of main and secondary tires is 36, and the central angle of each tire is 10°. When used in engineering applications, the total number of main tiles and secondary tiles is 48, and the central angle of each tile is 7.5°.

7. A two-stage tire forming process, characterized in that, Includes the following steps: S1. Driven by the drive assembly, the main and secondary tire pads shrink synchronously in the radial direction, reducing the radial dimension of the drum surface to 75%-82% of the inner diameter of the target tire. S2. Apply the tire material to the shrunken drum surface; S3. Drive the main and secondary tires to expand radially at a speed of 3-12 mm / s using the drive assembly until the drum surface reaches the preset tire inner diameter. During the drum expansion process, the radial height difference between any adjacent main and secondary tires is ≤0.05 mm. S4. Under stable drum surface conditions, bonding, reverse wrapping and rolling are carried out stably to ensure the symmetrical and firmness of each half of the component and the retaining ring, improve tire uniformity and strength, and at the same time complete the precise bonding process of the tire carcass and tread composite components. S5. Drive the main tile and secondary tile to shrink synchronously in the radial direction through the drive component, so that the molded body separates from the drum surface and completes demolding.

8. The tire secondary forming process according to claim 7, characterized in that, In S2, the tire material and the drum surface are continuously supported and bonded at multiple points, and the initial bonding flatness error is ≤0.3mm.

9. The tire secondary forming process according to claim 7, characterized in that, The speed of the tire inflation process is controlled in a gradient according to the tire specifications, specifically as follows: The bulge speed of passenger car tires is 10-12 mm / s; The inflation speed of a heavy-duty tire is 8-10 mm / s; The inflation speed of engineering tires is 3-5 mm / s.

10. The tire secondary forming process according to claim 7, characterized in that, The stretching error of the tire material at various locations during the expansion process is 0.5%–0.8%.

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