A two-stage forming drum with adjustable radial dimensions

Abstract

This invention relates to the field of tire forming drum technology, and more specifically, to a secondary forming drum with adjustable radial dimensions, comprising a main shaft, an expansion and contraction mechanism, and multiple drum assembly sets. The expansion and contraction mechanism includes an inner slide, an outer slide, and a connecting rod. The main shaft is cylindrical, with the inner slide slidably mounted on the inner side of the main shaft and the outer slide slidably mounted on the outer side of the main shaft. The outer ring wall of the inner slide has protruding circular keys, and multiple sets of circular keys are spaced along the axial direction of the inner slide to correspond to different radial expansion and contraction dimensions. The main shaft has a groove along the axial direction for the circular keys to pass through, and the outer slide has a slot for mounting the circular keys. The two ends of the connecting rod are rotatably mounted between the outer slide away from the main shaft and the drum assembly, respectively. This invention improves the compatibility of the forming drum with tire blanks of different diameters of similar specifications, reduces the workload of redesigning and producing forming drums for each similar size specification, and lowers the tire manufacturing cost.

Description

Technical Field

[0001] This invention relates to the field of tire forming drum technology, and in particular to a two-stage forming drum with adjustable radial dimensions. Background Technology

[0002] With the continuous development of the global automotive industry and the increasing demand for transportation, tires, as a key component in contact between vehicles and the ground, are seeing their sales and application scope expand. Tire performance directly affects vehicle driving safety, comfort, and fuel economy. Therefore, the market demand for tires is showing a trend of diversification and segmentation. Against this market background, the tire manufacturing industry is facing new challenges, namely, producing tires of various sizes that can meet the needs of different vehicle models and different usage scenarios.

[0003] The secondary forming drum is a forming device used in tire manufacturing. It is mainly used to initially shape the semi-finished tire according to the tire's design shape. Through radial contraction movement, the orderly arranged semi-finished tires are supported and the tire blank is formed when it reaches its maximum expansion position. Then, the formed tire blank is unloaded through contraction movement. The so-called "secondary method" refers to the second step in the two main steps of tire forming, which includes: First forming: In this step, the primary forming drum is used to attach components such as the ply layer and crown layer to the forming drum to form a tire blank with a basic outline; Second forming: Based on the first forming, the secondary forming drum is used to further modify the shape and adjust the size of the tire blank to make it more in line with the tire's design requirements.

[0004] In the prior art, Chinese invention patent CN105073396B discloses a molding drum having multiple segments forming a circumferential surface. The molding drum has one end mounted on the outer circumferential surface of a cylindrical sliding member externally embedded in a drum shaft in a swingable manner, and multiple swing arms mounted on the segments in a swingable manner at the other end. The molding drum includes multiple segment expansion and contraction mechanisms arranged at intervals along the drum shaft, which are composed of the multiple swing arms. The molding drum is expanded and contracted by the multiple segment expansion and contraction mechanisms as the sliding member moves in the direction of the drum shaft.

[0005] Regarding the aforementioned technologies, the inventors believe that the following drawbacks exist: because the length of the swing arm of the forming drum is fixed after design and assembly, the expansion and contraction dimensions of the forming drum are also fixed. This means that the same forming drum can only be used to produce wheel blanks of one diameter. When processing wheel blanks of different diameters with similar specifications (such as common 16-inch, 17-inch, and 18-inch tires), multiple models of forming drums are required to meet production needs. This means that the forming drums of similar sizes need to be redesigned and reproduced, which undoubtedly increases the tire manufacturing cost and leads to a significant waste of human and material resources. Summary of the Invention

[0006] To address the technical problem of dedicated dimensions for secondary forming drums in the prior art, this application provides a secondary forming drum with adjustable radial dimensions.

[0007] The present invention provides a secondary forming drum with adjustable radial dimensions, employing the following technical solution:

[0008] A radially adjustable secondary forming drum includes a main shaft, an expansion and contraction mechanism, and multiple drum tile assemblies. The drum tile assemblies are connected to the outer side of the expansion and contraction mechanism. The expansion and contraction mechanism is slidably assembled with the main shaft and is used to push the drum tile assemblies to move back and forth radially along the main shaft. The expansion and contraction mechanism includes an inner slide, an outer slide, and a connecting rod. The main shaft is cylindrical. The inner slide is slidably assembled on the inner side of the main shaft, and the outer slide is slidably assembled on the outer side of the main shaft. The outer ring wall of the inner slide has a raised circular key. Multiple sets of circular keys are spaced along the axial direction of the inner slide and are used to correspond to different radial expansion and contraction dimensions. The main shaft has a groove along the axial direction for the circular keys to pass through. The outer slide has a slot for assembling the circular keys. The two ends of the connecting rod are rotatably assembled between the outer slide away from the main shaft and the drum tile assembly.

[0009] Preferably, the outer slide is cylindrical, and a circular hole is provided at the center of the outer slide for sliding assembly with the main shaft. The axis of the circular hole is coaxial with the axis of the main shaft. A U-shaped block is provided on the outer ring wall of the outer slide along its radial direction. The U-shaped block is connected to a rotating shaft and is used for rotating assembly with the connecting rod. Multiple sets of U-shaped blocks are arranged at equal angles along the center of the circular hole. A flat portion is provided between two sets of adjacent U-shaped blocks. The groove is provided on the corresponding flat portion. The flat portion has a connecting hole that connects to the groove. The connecting hole is used for screwing the outer slide and the circular key.

[0010] Preferably, the drum tile assembly includes a tile, a guide rail, and a slider. The tile is mounted on the top wall of the guide rail, and the slider is slidably mounted on the bottom wall of the guide rail. Depending on the shape of the tile, the drum tile assembly is divided into a narrow drum tile assembly and a wide drum tile assembly. The drum tile assemblies are arranged in even numbers, with the narrow drum tile assemblies and the wide drum tile assemblies arranged sequentially adjacent to each other. The expansion and contraction mechanism includes two sets of outer slide blocks. The outer slide blocks are connected to the inner slide blocks and are spaced apart along the axial direction of the inner slide blocks. The two sets of outer slide blocks are a first outer slide block and a second outer slide block, respectively. The first outer slide block is located at one end near the main shaft. The U-shaped block of the first outer slide block and the U-shaped block of the second outer slide block are set at an angle in the circumferential direction for assembling the narrow drum tile assembly and the wide drum tile assembly.

[0011] Preferably, the top wall of the guide rail has a protruding T-shaped portion, and the bottom wall of the tile has a T-shaped groove at its center. The T-shaped groove is slidably fitted with the T-shaped portion. The top wall of the T-shaped portion has a threaded hole, and the tile has a through hole for screw connection with the threaded hole.

[0012] Preferably, the tile corresponding to the narrow drum tile assembly is a narrow tile, and the tile corresponding to the wide drum tile assembly is a wide tile. The central angle of the outermost arc length of the narrow tile is equal to the central angle of the outermost arc length of the wide tile. The narrow tile has an inwardly inclined portion on both sides near the wide tile, and the wide tile has an outwardly inclined portion on both sides near the narrow tile. The inwardly inclined portion and the outwardly inclined portion are adapted to each other. When the forming drum is in the expanded state, the outwardly inclined portion is in surface contact with the inwardly inclined portion, and the outwardly inclined portion is located on the side of the inwardly inclined portion closer to the main shaft.

[0013] Preferably, the connecting rod includes a first connecting rod and a second connecting rod. One end of the first connecting rod is hinged to the rotating shaft of the first outer slide block, and the other end of the first connecting rod is hinged to the slider of the narrow drum tile assembly. A clearance groove is provided in the middle of the guide rail of the narrow drum tile assembly. One end of the second connecting rod is hinged to the rotating shaft of the first outer slide block, and the other end of the second connecting rod is hinged to the clearance groove of the guide rail of the narrow drum tile assembly. The first connecting rod and the second connecting rod are hinged on the rotating shaft of the same set of U-shaped blocks, and the first connecting rod and the second connecting rod are arranged in a V-shape. The length of the first connecting rod is less than the length of the second connecting rod.

[0014] Preferably, the connecting rod further includes two sets of third connecting rods. The wide tile assembly is provided with two sets of sliders. The two sets of sliders are arranged at intervals along the guide rail of the wide tile assembly. One end of one set of third connecting rods is hinged to the pivot of the second outer slide, and the other end of the third connecting rod is hinged to the slider of the same set of wide tile assemblies. One end of the other set of third connecting rods is hinged to the pivot of the second outer slide, and the other end of the third connecting rod is hinged to the slider of the other set of wide tile assemblies. Both sets of third connecting rods are hinged to the pivot of the same set of U-shaped blocks, and the two sets of third connecting rods are arranged in a V-shape. The length of the third connecting rod is less than the length of the first connecting rod.

[0015] Preferably, the expansion and contraction mechanism further includes a guide plate and a guide rod. The guide plate is coaxially arranged with and connected to the main shaft. The guide plate is located on the side close to the slider. One end of the guide rod is slidably assembled with the guide plate. The guide rod slides radially along the guide plate. The other end of the guide rod is connected to the bottom of the guide rail of the drum assembly. Multiple sets of guide rods are provided corresponding to the drum assembly.

[0016] Preferably, the multiple sets of circular keys along the axial direction of the inner slide are sequentially a first-inch circular key, a second-inch circular key, a third-inch circular key, and a fixed-size circular key. The fixed-size circular key is used to connect with the groove of the second outer slide. The first-inch circular key, the second-inch circular key, and the third-inch circular key correspond to different radial dimensions. The circular key and the inner slide are designed separately. The outer ring wall of the inner slide has a groove for assembling the circular key. The end wall of the inner slide has a screw hole communicating with the groove. The circular key is inserted into the groove. The screw hole is threaded with a set screw to abut the circular key against the inner wall of the groove.

[0017] Preferably, the expansion and contraction mechanism is provided in two sets, and the two sets of expansion and contraction mechanisms are installed in a mirror image along the axis center of the main shaft. A hinge shaft is provided between the third connecting rod of the second outer slide of one set and the third connecting rod of the second outer slide of the other set. The hinge shaft is located at the center of the two hinge points of the third connecting rod. When the forming drum is in the expanded state, the second outer slide of the expansion and contraction mechanism of one set is in contact with the second outer slide of the expansion and contraction mechanism of the other set.

[0018] The beneficial effects of this invention are as follows:

[0019] By configuring an inner slide and an outer slide, with a first outer slide on the inner slide for matching different radial dimensions, when it is necessary to adjust and switch between different radial dimensions to meet the production of different sizes, the outer slide and the inner slide are disassembled by unscrewing the screws. Then, the outer slide is pushed to slide along the axial direction of the main shaft, so that the outer slide moves from one set of grooves corresponding to the inner slide's key to another set of grooves corresponding to the inner slide's key. Finally, the screws are tightened, thereby completing the adjustment of the expansion and contraction dimensions of the drum assembly. This improves the compatibility of the forming drum with different diameter wheel blanks of similar specifications, reduces the workload of redesigning and producing forming drums for each similar size specification, reduces human and material resources, and lowers the tire manufacturing cost.

[0020] By incorporating guide plates and connecting rods, the radial movement of the drum tile assembly along the main shaft is limited, thereby improving the expansion and contraction accuracy of the drum tile assembly. The guide plates are positioned on the side close to the slider, and multiple sets of guide rods are provided corresponding to the drum tile assembly. This ensures that the guide rods are positioned in relation to the slider, limiting the slider as it slides to one end of the guide rail, preventing the slider from slipping off the guide rail, improving the reliability and stability of the slide rail, and ensuring the normal expansion and contraction of the drum tile assembly.

[0021] By incorporating narrow and wide drum tile assemblies in even-numbered arrays, with the narrow and wide drum tile assemblies arranged sequentially adjacent to each other, interference between adjacent sets of drum tile assemblies during contraction is avoided, ensuring normal expansion and contraction of the drum tile assemblies. The top wall of the guide rail has a raised T-shaped section, and the bottom wall of the drum tile has a T-shaped groove at its center. The T-shaped groove slides with the T-shaped section. The top wall of the T-shaped section has a threaded hole, and the tile has a through hole for connection with the threaded hole screw. The detachable tile design reduces the weight required to slide the outer slide block to a certain extent, facilitating the operator to adjust the radial dimension of the forming drum. Attached Figure Description

[0022] Figure 1 This is a perspective view of an 18-inch expanded shape in an embodiment of this application;

[0023] Figure 2 This is the 18-inch retractable front view in the embodiments of this application;

[0024] Figure 3 This is an 18-inch expanded cross-sectional perspective view of an embodiment of this application;

[0025] Figure 4 This is a 16-inch expanded cross-sectional perspective view of an embodiment of this application;

[0026] Figure 5 This is a left view of the wide drum tile assembly in the embodiments of this application;

[0027] Figure 6 This is a perspective cross-sectional view of the wide-brick tile assembly in the embodiments of this application;

[0028] Figure 7 This is a left view of the narrow drum tile assembly in the embodiments of this application;

[0029] Figure 8 This is a partial exploded view of the narrow drum tile assembly in the embodiments of this application;

[0030] Figure 9 This is a partial perspective view of an embodiment of this application;

[0031] Figure 10 yes Figure 9 The left view in the middle;

[0032] Figure 11 yes Figure 10 A schematic diagram of the contraction state in the middle;

[0033] Figure 12 This is a schematic diagram of the assembly of the inner slide and the outer slide in an embodiment of this application;

[0034] Figure 13 This is a perspective view of the inner slide in the embodiment of this application;

[0035] Figure 14 This is a front view of the inner slide in an embodiment of this application.

[0036] Explanation of reference numerals in the attached figures:

[0037] 1. Spindle; 101. Slide groove; 2. Expansion / contraction mechanism; 201. Inner slide; 202. Outer slide; 2021. First outer slide; 2022. Second outer slide; 203. Connecting rod; 2031. First connecting rod; 2032. Second connecting rod; 2033. Third connecting rod; 204. Circular key; 2041. First-inch circular key; 2042. Second-inch circular key; 2043. Third-inch circular key; 2044. Fixed-size circular key; 205. Groove; 206. Circular hole; 207. U-block; 210. Flat part; 211. 1. Screw hole; 212. Connecting hole; 213. Guide plate; 2131. Guide groove; 214. Guide rod; 215. Hinge shaft; 3. Drum tile assembly; 301. Tile; 3011. Primary tile; 3012. Secondary tile; 3013. Tertiary tile; 3015. Step section two; 302. Guide rail; 303. Slider; 304. T-slot; 305. T-shaped section; 4. Narrow drum tile assembly; 401. Narrow tile; 4011. Inward tilting section; 402. Clearance groove; 5. Wide drum tile assembly; 501. Wide tile; 5011. Outward tilting section. Detailed Implementation

[0038] This section will describe in detail the specific embodiments of this application. Preferred embodiments of this application are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so as to intuitively and vividly understand each technical feature and overall technical solution of this application, but they should not be construed as limiting the scope of protection of this application.

[0039] In the description of this application, if directional descriptions are involved, such as "up," "down," "front," "back," "left," "right," etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, it is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. When a feature is referred to as "set," "fixed," or "connected" to another feature, it can be directly set, fixed, or connected to the other feature, or it can be indirectly set, fixed, or connected to the other feature.

[0040] In the description of this application, the term "several" means one or more, and "more than" means two or more. The terms "greater than," "less than," and "exceeding" should be understood as excluding the stated number, while "above," "below," and "within" should be understood as including the stated number. The terms "first" and "second" should be understood as distinguishing technical features and not as indicating or implying relative importance, the number of indicated technical features, or the order of the indicated technical features.

[0041] Furthermore, unless otherwise defined, the technical and scientific terms used in this application have the same meanings as commonly understood by one of ordinary skill in the art. The terminology used in this application is for the purpose of describing particular embodiments only and not for limiting the application. It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or collections thereof.

[0042] Example: Figure 1-14As shown, a secondary forming drum with adjustable radial dimensions includes a main shaft 1, an expansion and contraction mechanism 2, and multiple sets of drum tile assemblies 3. The drum tile assemblies 3 are connected to the outer side of the expansion and contraction mechanism 2. The expansion and contraction mechanism 2 is slidably assembled with the main shaft 1 and is used to push the drum tile assemblies 3 to move back and forth along the radial direction of the main shaft 1. The expansion and contraction mechanism 2 includes an inner slide 201, an outer slide 202, and a connecting rod 203. The inner slide 201 is connected to the push rod of the forming machine. The main shaft 1 is cylindrical. The inner slide 201 is slidably assembled inside the main shaft 1 and slides along the axial direction of the main shaft 1. The outer slide 202 is slidably assembled inside the main shaft 1. On the outside of the main shaft 1 and sliding along the axial direction of the main shaft 1, the outer ring wall of the inner slide 201 has a raised circular key 204. Multiple sets of circular keys 204 are spaced apart along the axial direction of the inner slide 201 to correspond to different radial expansion and contraction dimensions. The main shaft 1 has a groove 101 along its axial direction for the circular keys 204 to pass through. Multiple sets of grooves 101 are provided corresponding to the circular keys 204. The outer slide 202 has a slot 205 for assembling the circular keys 204. Multiple sets of slots 205 are provided corresponding to the circular keys 204. The circular keys 204 pass through the grooves from the inner slide 201. Located within the groove 205, the outer slide 202 is connected to the key 204 by screws, thereby transmitting the force of the inner slide 201 sliding along the axial direction of the main shaft 1. This pushes the inner slide 201 to slide along the axial direction of the main shaft 1. When it is necessary to adjust and switch different radial dimensions to meet different production sizes, the screws are loosened to disassemble the key 204 between the outer slide 202 and the inner slide 201. Then, the outer slide 202 is pushed to slide along the axial direction of the main shaft 1, thus allowing the outer slide 202 to slide from its set of grooves 205 and the inner slide 201. The circular key 204 of the outer slide 202 is correspondingly assembled with another set of grooves 205 of the outer slide 202 and another set of circular keys 204 of the inner slide 201. Then, it is locked with screws to complete the adjustment of the expansion and contraction size of the drum assembly 3. The two ends of the connecting rod 203 are respectively rotatably assembled between the outer slide 202 away from the main shaft 1 and the drum assembly 3. The connecting rod 203 is used to convert the axial movement of the outer slide 202 along the main shaft 1 into the radial movement of the main shaft 1. There are multiple sets of connecting rods 203 corresponding to the drum assembly 3, which are used to drive multiple sets of drum assemblies 3.

[0043] Regarding the specific structure of the outer slide block 202, the outer slide block 202 is cylindrical. A circular hole 206 is provided at the center of the outer slide block 202 for sliding assembly with the main shaft 1. The axis of the circular hole 206 is coaxial with the axis of the main shaft 1. U-shaped blocks 207 are radially protruding from the outer ring wall of the outer slide block 202. Each U-shaped block 207 is connected to a rotating shaft and used for rotating assembly with the connecting rod 203. Multiple sets of U-shaped blocks 207 are arranged at equal angular intervals along the center of the circular hole 206. A flat portion 210 is provided between two adjacent sets of U-shaped blocks 207. A groove 205 is provided corresponding to the flat portion 210. A connecting hole 210 is provided in the flat portion 210 to connect with the groove 205. 12. The connecting hole 212 is used for screw connection between the outer slide 202 and the round key 204. The round key 204 is provided with screw holes 211 for screw connection. In this embodiment, six sets of U-shaped blocks 207 are provided. By providing U-shaped blocks 207, the stability of the rotational assembly of the connecting rod 203 and the outer slide 202 is improved, and the smoothness and stability of the expansion and contraction of the drum tile assembly 3 are improved. By providing the flat part 210 and the connecting hole 212, when adjusting the expansion and contraction size of the drum tile assembly 3, it is convenient to match and combine different grooves 205 on the outer slide 202 with different round keys 204 on the inner slide 201, thereby improving the efficiency of adjusting the radial size.

[0044] To prevent adjacent sets of tile assemblies 3 from interfering with each other during contraction, thus hindering contraction, the prior art employs tiles 301 of different widths and shapes. Specifically, the outermost arc length and central angle of the wide and narrow tiles 301 are the same, but the innermost arc length and central angle of the wide tile 501 are greater than that of the narrow tile 401. This results in different radial movement distances during contraction, preventing interference. Therefore, to drive the two sets of different tile assemblies... Component 3 requires two sets of outer slide blocks 202. The tile assembly 3 includes tiles 301, guide rails 302, and sliders 303. Tiles 301 are mounted on the top wall of guide rails 302, and sliders 303 are slidably mounted on the bottom wall of sliders 303. Depending on the shape of the tiles 301, the tile assembly 3 is divided into narrow tile assemblies 4 and wide tile assemblies 5. The tile assemblies 3 are arranged in even numbers, with narrow tile assemblies 4 and wide tile assemblies 5 arranged sequentially adjacent to each other. The expansion and contraction mechanism 2 includes two sets of outer slide blocks 202. The outer slide 202 is connected to the inner slide 201 and is arranged at intervals along the axial direction of the inner slide 201. The two sets of outer slides 202 are the first outer slide 2021 and the second outer slide 2022, respectively. The first outer slide 2021 is located at one end near the main shaft 1. The U-shaped block 207 of the first outer slide 2021 and the U-shaped block 207 of the second outer slide 2022 are set at an angle in the circumferential direction for assembling the narrow drum tile assembly 4 and the wide drum tile assembly 5. By using the first outer slide 202... The first outer slide 2021 and the second outer slide 2022 are arranged along the axial direction of the main shaft 1, and respectively push the narrow drum tile assembly 4 and the wide drum tile assembly 5. Since the tile 301 of the narrow drum tile assembly 4 and the wide drum tile assembly 5 are different in size, and the U-shaped block 207 of the first outer slide 2021 and the U-shaped block 207 of the second outer slide 2022 are staggered, the radial movement distance of the narrow drum tile assembly 4 and the wide drum tile assembly 5 is different, thereby avoiding the risk of interference between the two adjacent sets of drum tile assemblies 3 during shrinkage.

[0045] In this embodiment, the drum tile assembly 3 is provided with 12 sets, the narrow drum tile assembly 4 and the wide drum tile assembly 5 are both provided with 6 sets, and the U-shaped block 207 of the first outer slide 2021 and the U-shaped block 207 of the second outer slide 2022 are set at a 30° angle in the circumferential direction.

[0046] When the radial dimension of the forming drum is adjusted from a large size to a small size, for example, from 18 inches to 16 inches, the radial shrinkage will cause interference between the tiles 301. To solve this technical problem, the tiles 301 can be designed to correspond to the size of the smaller forming drum, i.e., 16 inches, to resolve the interference issue. However, when switching from 16 inches to 18 inches, gaps exist between different drum tile assemblies 3 when the forming drum is in the expanded state, resulting in insufficient support for the tire and thus affecting the tire forming quality to some extent. To improve the tire processing quality, this example adopts a tile 301 disassembly scheme, i.e., 16-inch and 17-inch... Both 18-inch and 18-inch tiles have corresponding sizes to eliminate gaps between them when adjusting the radial dimensions of the forming drum. To improve the assembly accuracy of the tile 301 and the guide rail 302, the top wall of the guide rail 302 has a protruding T-shaped part 305, and the bottom wall of the tile 301 has a T-shaped groove 304 at its center. The T-shaped groove 304 and the T-shaped part 305 are slidably assembled. The top wall of the T-shaped part 305 has a threaded hole, and the tile 301 has a through hole for connecting with the threaded hole screw. The detachable design of the tile 301 reduces the weight of pushing the outer slide block 202 to slide to a certain extent, making it easier for the operator to adjust the radial dimensions of the forming drum.

[0047] Furthermore, to improve the replacement efficiency of tile 301 and reduce the processing difficulty of tile 301, tile 301 includes a primary tile 3011, a secondary tile 3012, and a tertiary tile 3013. The secondary tile 3012 has a through hole and is threadedly connected to the guide rail 302 by a screw. The secondary tile 3012 is located between the primary tile 3011 and the tertiary tile 3013. Steps 3015 are provided on both sides of the secondary tile 3012 near the primary tile 3011 and the tertiary tile 3013, making the cross-section of the secondary tile 3012 convex. A step 1 is provided on the side of the primary tile 3011 near the secondary tile 3012, and the step 1 and step 2 3015 are compatible. During assembly, step one is located above step two 3015. Step three is provided on the side of the third-level tile 3013 near the second-level tile 3012. Step three is adapted to step two 3015. During assembly, step three is located above step two 3015. Under the limitation of T-shaped part 305 and T-shaped groove 304, plus the surface contact between step two 3015 and step one, and the surface contact between step three and step one, the assembly of first-level tile 3011 and third-level tile 3013 is completed. By opening through holes corresponding to step two 3015 on the top wall of step one and step three, the installation of screws is reduced, and the disassembly and assembly efficiency of tile 301 is improved.

[0048] Regarding the structural design of the tile 301 in the narrow-brick tile assembly 4 and the wide-brick tile assembly 5, the tile 301 corresponding to the narrow-brick tile assembly 4 is referred to as the narrow tile 401, and the tile 301 corresponding to the wide-brick tile assembly 5 is referred to as the wide tile 501. The central angle of the outermost arc length of the narrow tile 401 is equal to the central angle of the outermost arc length of the wide tile 501. The narrow tile 401 has inwardly inclined portions 4011 on both sides near the wide tile 501, so that the central angle of the arc length of the narrow tile 401 gradually decreases from the outside to the inside. The wide tile 501 has outwardly inclined portions 5011 on both sides near the narrow tile 401, so that the central angle of the arc length of the wide tile 501 gradually decreases from the outside to the inside. The inner inclined portion 4011 and the outer inclined portion 5011 are adapted to each other. When the forming drum is in the expanded state, the outer inclined portion 5011 and the inner inclined portion 4011 are in surface contact, and the outer inclined portion 5011 is located on the side of the inner inclined portion 4011 closer to the main shaft 1. By designing the structure of the narrow tile 401 and the wide tile 501, and by using the first outer slide 2021 and the second outer slide 2022 to push the expansion and contraction of the wide drum tile assembly 5 and the narrow drum tile assembly 4 respectively, differential speed pushing is achieved. When the forming drum is in the contracted state, the wide drum tile assembly 5 is located on the side of the narrow drum tile assembly 4 closer to the main shaft 1, avoiding interference between the two adjacent sets of drum tile assemblies 3.

[0049] Regarding the specific structure of the assembly of the first outer slide block 2021 and the narrow drum tile assembly 4, the connecting rod 203 includes a first connecting rod 2031 and a second connecting rod 2032. One end of the first connecting rod 2031 is hinged to the rotating shaft of the first outer slide block 2021, and the other end of the first connecting rod 2031 is hinged to the slider 303 of the narrow drum tile assembly 4. A clearance groove 402 is provided in the middle of the guide rail 302 of the narrow drum tile assembly 4. One end of the second connecting rod 2032 is hinged to the rotating shaft of the first outer slide block 2021, and the other end of the second connecting rod 2032 is hinged to the slider 303 of the narrow drum tile assembly 4. The guide rail 302 of 4 is hinged to the clearance groove 402. The first connecting rod 2031 and the second connecting rod 2032 are hinged to the same set of U-shaped blocks 207 on the rotating shaft. The first connecting rod 2031 and the second connecting rod 2032 are arranged in a V shape. The length of the first connecting rod 2031 is less than the length of the second connecting rod 2032. During the sliding process of the first outer slide block 2021, the first connecting rod 2031 rotates while pushing the slider 303 to slide along the bottom wall of the slide rail. The second connecting rod 2032 rotates with the bottom wall of the slide rail, thereby completing the expansion and contraction of the narrow drum tile assembly 4.

[0050] In this embodiment, the length of the guide rail 302 is 250mm, the straight-line distance between the two hinge points of the first connecting rod 2031 is 93mm, and the straight-line distance between the two hinge points of the second connecting rod 2032 is 127mm. When the drum assembly 3 is in the retracted state, the slide rail is located at one end of the guide rail 302. At this time, the straight-line distance between the hinge point of the first connecting rod 2031 and the slider 303 and the hinge point of the second connecting rod 2032 and the guide rail 302 is 150mm.

[0051] Regarding the specific structure of the assembly between the second outer slide block 2022 and the wide tile assembly 5, the connecting rod 203 further includes two sets of third connecting rods 2033. The wide tile assembly 5 is provided with two sets of sliders 303, which are arranged at intervals along the guide rail 302 of the wide tile assembly 5. One end of one set of third connecting rods 2033 is hinged to the rotating shaft of the second outer slide block 2022, and the other end of the third connecting rod 2033 is hinged to one set of sliders 303 of the wide tile assembly 5. One end of the other set of third connecting rods 2033 is connected to the second outer slide block 2022. The pivot of 022 is hinged, and the other end of the third link 2033 is hinged to the slider 303 of another set of wide drum tile assembly 5. Both sets of third links 2033 are hinged to the pivot of the same set of U-shaped blocks 207, and the two sets of third links 2033 are arranged in a V-shape. The length of the third link 2033 is less than the length of the first link 2031. During the sliding process of the second outer slide block 2022, the two sets of third links 2033 rotate while pushing the slider 303 to slide along the bottom wall of the slide rail, thereby completing the expansion and contraction of the wide drum tile assembly 5.

[0052] In this embodiment, the length of the guide rail 302 is 250mm, and the straight-line distance between the two hinge points of the third link 2033 is 85mm. When the drum tile assembly 3 is in the retracted state, one set of its slide rails is located at one end of the guide rail 302. At this time, the straight-line distance between the hinge point of one set of the third link 2033 and its set of sliders 303 and the hinge point of another set of the second link 2032 and its set of sliders 303 is 148mm.

[0053] To limit the degree of freedom of movement of the drum tile assembly 3, allowing it to move radially along the main shaft 1, the expansion and contraction mechanism 2 also includes a guide plate 213 and a guide rod 214. The guide plate 213 is coaxially arranged with and connected to the main shaft 1. The guide plate 213 is located on the side near the slider 303. The guide plate 213 has a guide groove 2131 on its outer ring wall and radially therefor sliding assembly with the guide rod 214. One end of the guide rod 214 is slidably assembled with the guide plate 213 and slides radially along the guide plate 213. The other end of the guide rod 214 is connected to the bottom of the guide rail 302 of the drum tile assembly 3. Multiple sets of guide rods 214 are provided corresponding to the drum tile assembly 3. The multiple sets of guide rods 214 are arranged at equal angular intervals along the axis of the main shaft 1. The guide plate 213 is positioned on one side of the first outer slide block 2021, and the second outer slide block 2022 is positioned on the other side of the first outer slide block 2021, near the side of the slider 303, i.e., near the end of the main shaft 1. This avoids the guide plate 213 being positioned in the middle of the main shaft 1, which would interfere with the swing of the second connecting rod 2032 and ensure the normal expansion and contraction of the drum assembly 3. At the same time, the guide plate 213 is positioned on the side near the slider 303, and multiple sets of guide rods 214 are provided corresponding to the drum assembly 3, so that the guide rods 214 are corresponding to the slider 303. The guide rods 214 can limit the slider 303 that slides to one end of the guide rail 302, preventing the slider 303 from slipping off the guide rail 302, improving the reliability and stability of the slide rail, and ensuring the normal expansion and contraction of the drum assembly 3.

[0054] In the assembly structure of the key 204 and the inner slide 201, multiple sets of key 204 are provided. These multiple sets of key 204, arranged sequentially along the axial direction of the inner slide 201, are: a first-inch key 2041, a second-inch key 2042, a third-inch key 2043, and a fixed-size key 2044. The fixed-size key 2044 is used to connect with the groove 205 of the second outer slide 2022. The first-inch key 2041, second-inch key 2042, and third-inch key 2043 correspond to different radial dimensions. When it is necessary to adjust the radial dimension of the forming drum, the first outer slide 2021 is slid along the axial direction of the inner slide 201, allowing the different sets of key 2044 to move. The groove 205 is connected to the first-inch round key 2041, the second-inch round key 2042, and the third-inch round key 2043 respectively, thereby completing the adjustment of the radial dimension of the forming drum. The round key 204 and the inner slide 201 are designed separately. The outer ring wall of the inner slide 201 has a groove for assembling the round key 204. The end wall of the inner slide 201 has a screw hole 211 that connects to the groove. The round key 204 is inserted into the groove. The screw hole 211 is threaded with a set screw to abut the round key 204 against the inner wall of the groove. By adopting a separate design for the round key 204, the processing difficulty of the inner slide 201 is reduced, and it is easy to pass the round key 204 through the groove 205, which facilitates the assembly of the forming drum.

[0055] Regarding the specific structural design of the first-inch circular key 2041, the second-inch circular key 2042, the third-inch circular key 2043, and the fixed-size circular key 2044, multiple sets of fixed-size circular keys 2044 are arranged along the center of the inner slide block 201 at intervals of angle α. The interval angle between the second-inch circular key 2042 and the first-inch circular key 2041 is α / 2 times X, where X is an integer. The interval angle between the third-inch circular key 2043 and the second-inch circular key 2042 is α / 2 times Y, where Y is an integer. The included angle between the first-inch circular key 2041 and the third-inch circular key 2043 is less than or equal to 180°. Angle α is equal to 360° divided by the number of the drum tile assembly 3.

[0056] In this embodiment, angle α is 60°. The first inch level represents the circular key 204 corresponding to a 16-inch component, the second inch level represents the circular key 204 corresponding to a 17-inch component, and the third inch level represents the circular key 204 corresponding to an 18-inch component. The interval angle between the second-inch circular key 2042 and the first-inch circular key 2041 is 120°, the interval angle between the third-inch circular key 2043 and the second-inch circular key 2042 is 60°, the included angle between the first-inch circular key 2041 and the third-inch circular key 2043 is less than or equal to 180°, and the center distance between the second-inch circular key 2042 and the first-inch circular key 2041 is 5.94 mm. The center distance between the round key 2043 and the second-inch round key 2042 is 6.3mm, which makes the first-inch round key 2041, the second-inch round key 2042, and the third-inch round key 2043 set in the same semicircle, which facilitates the adjustment of the first outer slide block 2021. Of course, the first-inch round key 2041, the second-inch round key 2042, and the third-inch round key 2043 are all arranged facing upwards. By staggering the arrangement of the first-inch round key 2041, the second-inch round key 2042, and the third-inch round key 2043, the risk of pressure concentration caused by multiple sets of grooves in the same axial direction of the inner slide block 201 is reduced, which may affect the rigidity of the inner slide block 201.

[0057] To improve the stability of the expansion and contraction of the drum assembly 3, two sets of expansion and contraction mechanisms 2 are provided. The two sets of expansion and contraction mechanisms 2 are installed in a mirror image along the axis center of the main shaft 1. A hinge shaft 215 is provided between the third connecting rod 2033 of the second outer slide 2022 of one set and the third connecting rod 2033 of the other set of second outer slide 2022. The hinge shaft 215 is located at the center of the two hinge points of the third connecting rod 2033. When the forming drum is in the expanded state, the second outer slide 2022 of one set of expansion and contraction mechanisms 2 and the second outer slide 2022 of the other set of expansion and contraction mechanisms 2 are in contact with each other. By having two sets of expansion and contraction mechanisms 2 installed in a mirror image, the drum assembly 3 is driven to expand and contract, which improves the uniformity of the force on the drum assembly 3, improves the expansion and contraction stability of the drum assembly 3, and ensures the processing quality of the tire.

[0058] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A radially adjustable secondary forming drum, comprising a main shaft, an expansion and contraction mechanism, and multiple sets of drum tile assemblies, wherein the drum tile assemblies are connected to the outer side of the expansion and contraction mechanism, the expansion and contraction mechanism is slidably assembled with the main shaft and is used to push the drum tile assemblies to move back and forth radially along the main shaft, characterized in that: The expansion and contraction mechanism includes an inner slide, an outer slide, and a connecting rod. The main shaft is cylindrical. The inner slide is slidably mounted on the inner side of the main shaft, and the outer slide is slidably mounted on the outer side of the main shaft. The outer ring wall of the inner slide has a raised circular key. Multiple sets of circular keys are spaced along the axial direction of the inner slide to correspond to different radial expansion and contraction dimensions. The main shaft has a groove along the axial direction for the circular key to pass through. The outer slide has a slot for assembling the circular key. The two ends of the connecting rod are rotatably mounted between the outer slide away from the main shaft and the drum assembly. The outer slide block is cylindrical, and a circular hole is provided at the center of the outer slide block for sliding assembly with the main shaft. The axis of the circular hole is coaxial with the axis of the main shaft. A U-shaped block is provided on the outer ring wall of the outer slide block along its radial direction. The U-shaped block is connected to a rotating shaft and is used for the rotation assembly of the connecting rod. Multiple sets of U-shaped blocks are arranged at equal angles along the center of the circular hole. A flat portion is provided between two sets of adjacent U-shaped blocks. The groove is provided on the corresponding flat portion. The flat portion has a connecting hole that connects to the groove. The connecting hole is used for screw connection between the outer slide block and the circular key. The drum tile assembly includes a tile, a guide rail, and a slider. The tile is mounted on the top wall of the guide rail, and the slider is slidably mounted on the bottom wall of the guide rail. Depending on the shape of the tile, the drum tile assembly is divided into a narrow drum tile assembly and a wide drum tile assembly. The drum tile assemblies are arranged in even numbers, with the narrow drum tile assembly and the wide drum tile assembly arranged sequentially adjacent to each other. The expansion and contraction mechanism includes two sets of outer slide blocks. The outer slide blocks are connected to the inner slide blocks and are spaced apart along the axial direction of the inner slide blocks. The two sets of outer slide blocks are a first outer slide block and a second outer slide block, respectively. The first outer slide block is located at one end near the main shaft. The U-shaped block of the first outer slide block and the U-shaped block of the second outer slide block are set at an angle in the circumferential direction for assembling the narrow drum tile assembly and the wide drum tile assembly.

2. The radially adjustable secondary forming drum according to claim 1, characterized in that: The top wall of the guide rail has a protruding T-shaped portion, and the bottom wall of the tile has a T-shaped groove at its center. The T-shaped groove is slidably fitted with the T-shaped portion. The top wall of the T-shaped portion has a threaded hole, and the tile has a through hole for screw connection with the threaded hole.

3. The radially adjustable secondary forming drum according to claim 2, characterized in that: The narrow drum tile assembly corresponds to a narrow tile, and the wide drum tile assembly corresponds to a wide tile. The central angle of the outermost arc of the narrow tile is equal to the central angle of the outermost arc of the wide tile. The narrow tile has an inwardly inclined portion on both sides near the wide tile, and the wide tile has an outwardly inclined portion on both sides near the narrow tile. The inwardly inclined portion and the outwardly inclined portion are adapted to each other. When the forming drum is in the expanded state, the outwardly inclined portion is in surface contact with the inwardly inclined portion, and the outwardly inclined portion is located on the side of the inwardly inclined portion closer to the main shaft.

4. A secondary forming drum with adjustable radial dimensions according to claim 3, characterized in that: The connecting rod includes a first connecting rod and a second connecting rod. One end of the first connecting rod is hinged to the pivot of the first outer slide block, and the other end of the first connecting rod is hinged to the slider of the narrow drum tile assembly. A clearance groove is provided in the middle of the guide rail of the narrow drum tile assembly. One end of the second connecting rod is hinged to the pivot of the first outer slide block, and the other end of the second connecting rod is hinged to the clearance groove of the guide rail of the narrow drum tile assembly. The first connecting rod and the second connecting rod are hinged on the pivot of the same set of U-shaped blocks, and the first connecting rod and the second connecting rod are arranged in a V-shape. The length of the first connecting rod is less than the length of the second connecting rod.

5. A secondary forming drum with adjustable radial dimensions according to claim 4, characterized in that: The connecting rod also includes two sets of third connecting rods. The wide tile assembly is provided with two sets of sliders. The two sets of sliders are arranged at intervals along the guide rail of the wide tile assembly. One end of one set of third connecting rods is hinged to the rotating shaft of the second outer slide, and the other end of the third connecting rod is hinged to the slider of the same set of wide tile assemblies. One end of the other set of third connecting rods is hinged to the rotating shaft of the second outer slide, and the other end of the third connecting rod is hinged to the slider of the other set of wide tile assemblies. Both sets of third connecting rods are hinged to the rotating shaft of the same set of U-shaped blocks, and the two sets of third connecting rods are arranged in a V-shape. The length of the third connecting rod is less than the length of the first connecting rod.

6. A secondary forming drum with adjustable radial dimensions according to claim 5, characterized in that: The expansion and contraction mechanism also includes a guide plate and a guide rod. The guide plate is coaxially arranged with and connected to the main shaft. The guide plate is located on the side close to the slider. One end of the guide rod is slidably assembled with the guide plate. The guide rod slides radially along the guide plate. The other end of the guide rod is connected to the bottom of the guide rail of the drum assembly. Multiple sets of guide rods are provided corresponding to the drum assembly.

7. A secondary forming drum with adjustable radial dimensions according to claim 6, characterized in that: The multiple sets of circular keys along the axial direction of the inner slide are sequentially a first-inch circular key, a second-inch circular key, a third-inch circular key, and a fixed-size circular key. The fixed-size circular key is used to connect with the groove of the second outer slide. The first-inch circular key, the second-inch circular key, and the third-inch circular key correspond to different radial dimensions. The circular key and the inner slide are designed separately. The outer ring wall of the inner slide has a groove for assembling the circular key. The end wall of the inner slide has a screw hole that communicates with the groove. The circular key is inserted into the groove. The screw hole is threaded with a set screw to abut the circular key against the inner wall of the groove.

8. A secondary forming drum with adjustable radial dimensions according to claim 7, characterized in that: The expansion and contraction mechanism is provided in two sets, and the two sets of expansion and contraction mechanisms are installed in a mirror image along the axis center of the main shaft. A hinge shaft is provided between the third connecting rod of the second outer slide of one set and the third connecting rod of the second outer slide of the other set. The hinge shaft is located at the center of the two hinge points of the third connecting rod. When the forming drum is in the expanded state, the second outer slide of the expansion and contraction mechanism of one set and the second outer slide of the expansion and contraction mechanism of the other set are in contact with each other.

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