Asynchronous tire direct pressure vulcanization center expansion mechanism

Abstract

An asynchronous tire direct pressure vulcanization center expansion mechanism includes a drive mechanism and a telescopic mechanism, the telescopic mechanism including a wide-tread connecting rod mechanism and a narrow-tread connecting rod mechanism; the drive mechanism includes a central piston rod, a narrow-tread fixed support fixed to the upper portion of the central piston rod, a wide-tread sliding support mounted on the narrow-tread fixed support, the wide-tread sliding support moving axially along the narrow-tread fixed support and the central piston rod, and a limited position chassis provided on the central piston rod; the narrow-tread connecting rod mechanism is connected to the narrow-tread fixed support, the wide-tread connecting rod mechanism is connected to the wide-tread sliding support, and the wide-tread connecting rod mechanism and the narrow-tread connecting rod mechanism are arranged alternately along the circumferential direction. When the mechanism is fully expanded, the outer surfaces of the wide-tread connecting rod mechanism and the narrow-tread connecting rod mechanism form a uniform and complete tire inner surface profile; when the mechanism is fully contracted, the maximum circumscribed circle diameter is smaller than the bead opening diameter of the finished tire. The present invention drives the wide and narrow drum tires to expand and contract in an orderly manner by the piston rod, thereby increasing the drum tire pressure load and the mechanism stability.

Description

Technical Field

[0001] The invention relates to a central expansion mechanism used on a tire vulcanizer, belonging to the technical field of tire vulcanizers. Background Art

[0002] The central mechanism is the core part of the shaping vulcanizer, mainly used for the retraction and expansion of the vulcanization bladder and the shaping of the tire. Before vulcanization, the central mechanism loads the bladder into the tire to shape it. After vulcanization, the bladder is vacuumed and pulled out from the inner ring of the tire to complete the tire demolding. The traditional inner mold vulcanization process of the shaping vulcanizer uses a central mechanism in combination with a flexible bladder. High-temperature steam is introduced into the bladder to provide the vulcanization temperature and pressure for the tire. However, the vulcanization bladder in this process has defects such as incomplete expansion, asymmetric structure, low vulcanization pressure, and steam condensation deposition. In addition, the bladder has poor thermal conductivity, consumes a large amount of steam during vulcanization, consumes a lot of energy, and has a short service life, which limits the production of high-performance radial tires.

[0003] Using a metal high-rigidity inner mold instead of a flexible capsule to vulcanize the tire can greatly increase the vulcanization pressure, and the mold has high control precision, good thermal conductivity, and long service life. Combined with electromagnetic induction heating technology, it can solve the inherent problems of the original flexible capsule. The direct pressure vulcanization inner mold mechanism is usually composed of multiple drum tiles arranged circumferentially. Its longitudinal outer contour curve is consistent with the inner contour curve of the finished tire. The radial expansion and contraction of the drum tile is achieved through the axial movement of the intermediate piston rod. Its structural form can be mainly divided into connecting rod type and inclined wedge type. The "Inner mold of tire direct pressure vulcanizer" disclosed in Chinese patent document CN103286885A,

[0004] , the "Tire Vulcanization Inner Mold" disclosed in CN103552175A, the "Asynchronous Expansion and Contraction Tire Direct Pressure Vulcanization Inner Mold" disclosed in CN109383056A, and the "Step-Type Tire Direct Pressure Vulcanization Inner Mold" disclosed in CN113085235A respectively proposed direct pressure inner molds with different motion mechanisms such as connecting rod type, guide rail type, asynchronous expansion and contraction type, and step-type. Among the above-mentioned structural forms, the inclined wedge type direct pressure inner mold has been improved and studied more because of its strong pressure bearing capacity and high molding accuracy. Among them, in order to expand the applicable range of tire sizes, the expansion and contraction ratio of the inner mold is improved by improving the order of drum shoe contraction. However, these direct pressure inner molds are only suitable for tires with a small aspect ratio. When applying pressure during vulcanization, only the radial pressure of the crown is considered. For tires with a large aspect ratio, the sidewall vulcanization of the tire blank also requires a higher pressure. The upper and lower layers of the drum shoe of the traditional metal inner mold have a small pressure bearing area, and cannot achieve sidewall pressure vulcanization of tires with a large aspect ratio.

[0005] Therefore, how to link the radial expansion and contraction of the drum shell with the lateral support to expand the application range of the tire is a focus that requires further innovative design and research in this field. Summary of the Invention

[0006] The purpose of the present invention is to provide an asynchronous tire direct pressure vulcanization center expansion mechanism to solve the problems of insufficient sidewall pressure bearing capacity of traditional metal inner molds, inability to be applied to sidewall pressure vulcanization of large aspect ratio tires, and small expansion and contraction ratio.

[0007] In order to achieve the above-mentioned purpose, the asynchronous tire direct pressure vulcanization center expansion drum mechanism of the present invention is solved by the following technical solutions:

[0008] The central expansion mechanism includes a driving mechanism and a telescopic mechanism, the telescopic mechanism includes a wide-wafer connecting rod mechanism and a narrow-wafer connecting rod mechanism; the driving mechanism includes a central piston rod, a narrow-wafer fixed support is fixedly provided on the upper part of the central piston rod, a wide-wafer sliding support is mounted on the narrow-wafer fixed support, the wide-wafer sliding support moves axially along the narrow-wafer fixed support and the central piston rod, and a limiting chassis is provided on the central piston rod below the wide-wafer sliding support; the narrow-wafer connecting rod mechanism is connected to the narrow-wafer fixed support, the wide-wafer connecting rod mechanism is connected to the wide-wafer sliding support, and the wide-wafer connecting rod mechanism and the narrow-wafer connecting rod mechanism are alternately arranged along the circumferential direction.

[0009] The center piston rod is connected to the driving cylinder of the vulcanizer center mechanism. The limit chassis is installed on the base of the tire shaping vulcanizer. The center piston rod is driven up and down by the cylinder, and the center piston rod drives the wide tile connecting rod mechanism and the narrow tile connecting rod mechanism to achieve extension and retraction; when the mechanism is fully expanded, the outer surfaces of the wide tile connecting rod mechanism (wide drum tile) and the narrow tile connecting rod mechanism (narrow drum tile) constitute a uniform and complete tire inner surface contour; when the mechanism is fully contracted, the narrow tile connecting rod mechanism is at the top and the wide tile connecting rod mechanism is at the bottom, and the maximum circumscribed circle diameter of the mechanism is smaller than the bead opening diameter of the finished tire.

[0010] Further:

[0011] The narrow shoe fixing support is connected to the central piston rod through a key.

[0012] Guide grooves are provided on the narrow shoe fixed support and the central piston rod to guide the axial movement of the wide shoe sliding support. A boss is provided below the guide groove on the central piston rod to limit and support the wide shoe sliding support. Wedge-shaped grooves are circumferentially arranged on the boss, with the number and location of the wedge grooves corresponding to the guide grooves.

[0013] The wide-wafer sliding support includes a wide-wafer support support ring and a wide-wafer support support plate. The wide-wafer support support plates are evenly arranged circumferentially in the inner hole of the wide-wafer support ring, and the wide-wafer support support plates are provided with hinge points for long connecting rods. The wide-wafer support support plates are located in the guide grooves on the narrow-wafer fixed support, so that the wide-wafer sliding support is mounted on the narrow-wafer fixed support and can move smoothly up and down along the guide grooves on the narrow-wafer fixed support and the center piston rod.

[0014] The number of the wide shoe connecting rod mechanisms and the narrow shoe connecting rod mechanisms is the same, the total number is 12 to 20, and the optimal total number is 16.

[0015] The wide tile connecting rod mechanism and the narrow tile connecting rod mechanism have the same structure, including drum tiles, drum frames, middle supports of drum frames, long connecting rods, short connecting rods and side connecting rods; the middle support of drum frames, drum frames and drum tiles are connected together in sequence, and two upper and lower long connecting rods are hinged on the middle support of drum frames, and the other ends of the two long connecting rods are hinged to the narrow tile fixed support or the wide tile sliding support to form a parallelogram connecting rod mechanism; a short connecting rod is hinged between the two long connecting rods (the two ends of the short connecting rod are respectively hinged to a long connecting rod); the side connecting rod includes an upper connecting rod and a lower connecting rod, the upper connecting rod is two short rods of equal length, one end of the two short rods is hinged together, and the other ends of the two short rods are respectively hinged to the upper part of the drum frame and the long connecting rod, the lower connecting rod includes a Y-shaped connecting rod and two short rods, one end of the Y-shaped connecting rod is hinged to the lower part of the drum frame, and the other end is hinged to the two short rods, and the other end of the two short rods is hinged to the long connecting rod. The hinged position of the long connecting rod is close to one end of the middle support of the drum frame. A guide rail slide is installed at the lower part of the drum frame, and a pulley is installed on the guide rail slide; a guide groove for the pulley is provided on the limiting chassis (the guide groove guides and limits the guide pulleys on the narrow tile drum frame guide rail slide and the wide tile drum frame guide rail slide when they move, realizing the motion guidance and axial limitation of the drum tile movement, ensuring the stability and accuracy of the drum tile movement. In addition, an opening is provided on the inner side of the guide groove corresponding to the narrow tile connecting rod mechanism. After the narrow drum tile shrinks, it can rise axially from the opening to make radial space for the wide drum tile to shrink). The guide rail slide is in the shape of a "7", which mainly supports the drum tile and guides the radial movement of the drum tile; a lower limit spring is connected between the guide rail slide and the Y-type connecting rod. An upper limit spring is connected between the hinge point of the two short rods in the upper connecting rod and the middle support of the drum frame.

[0016] The circumferential width of the drum shoe and the drum frame in the wide shoe connecting rod mechanism is greater than the circumferential width of the drum shoe and the drum frame in the narrow shoe connecting rod mechanism.

[0017] In the technical solution of the present invention:

[0018] 1. One end of the long connecting rod in the wide drum shoe connecting rod mechanism is hinged to the middle support of the drum frame, and the other end is hinged to the wide drum shoe sliding support on the central piston rod, forming a parallelogram connecting rod mechanism to achieve radial movement and support of the wide drum shoe;

[0019] 2. The side connecting rod is installed on the long connecting rod and the drum frame support. The plane movement of the long connecting rod drives the side connecting rod to rotate, and the self-locking feature of the mechanism is used to support the side of the drum shell;

[0020] 3. One end of the long connecting rod of the narrow shoe connecting rod mechanism is hinged to the middle support of the drum frame, and the other end is hinged to the narrow shoe fixed support of the central piston rod, and always moves with the piston rod;

[0021] 4. The multiple axial guide grooves on the central piston rod are used to guide and limit the wide tile sliding support. A boss is provided at the end of the guide groove, which can clamp the wide tile sliding support and move upward together during the rising process of the piston rod, driving the wide tile connecting rod mechanism to move and causing the wide drum tile to shrink radially.

[0022] The present invention has the following characteristics:

[0023] 1. The present invention adopts the combination of a guide rail slider and a connecting rod mechanism to achieve radial expansion and contraction of the drum shoe. The drum shoe adopts a double connecting rod to form a parallelogram stable structure. At the same time, a short rod is added in the middle of the connecting rod to form a virtual constraint, thereby increasing the rigidity of the connecting rod. The piston rod moving up and down drives the drum shoe to achieve radial expansion and contraction through the double connecting rod and the guide rail pulley. The movement precision is high, the friction resistance is small, and the operation is reliable.

[0024] 2. The present invention utilizes the self-locking principle of the connecting rod mechanism to achieve lateral support of the drum shoe. A set of connecting rod mechanisms is added to the upper and lower sides of the drum shoe. When the central piston rod moves downward to the maximum expansion position of the drum shoe, the double connecting rods that drive the radial extension of the drum shoe are in a horizontal state. At this time, the short connecting rods on the upper and lower sides are in the same straight line, the pressure angle is 90°, and the transmission angle is zero. The short rods on both sides of the drum shoe are at the dead point of the mechanism and cannot rotate. The short connecting rods only bear compressive stress, so they can provide support for the side of the drum shoe. Compared with directly installing a single connecting rod support in the vertical direction on the side of the drum shoe, the difference between this connecting rod mechanism scheme is that the force on the single connecting rod is perpendicular to the double connecting rod, so that the shear stress on the double connecting rod is maximized. When the two short connecting rods are at the dead point of the mechanism, the force transmitted from the drum shoe side to the double connecting rod through the short connecting rod can be decomposed into two components parallel and perpendicular to the double connecting rod, so that the force on the double connecting rod at this point is dispersed, reducing the shear stress of the double connecting rod and improving the structural stability. In this mechanism, the two short connecting rods are not perpendicular to the drum shoe side when they are collinear. When the drum shoe side bears pressure, the pressure is perpendicular to the side. This pressure can be decomposed into a compressive stress along the short connecting rod and a force component perpendicular to the short connecting rod. This force component acts on the drum shoe corners and generates bending stress. However, this bending stress is relatively small compared to the compressive stress acting on the short connecting rod, and its effect on the force at the drum shoe corners can be ignored. Therefore, the connecting rod mechanism proposed in this invention utilizes a self-locking mechanism to achieve support for the drum shoe side, which has a more obvious advantage.

[0025] 3. The present invention adopts a double-link mechanism in conjunction with a guide rail slider to realize radial expansion and contraction of the drum shoe. When the center piston rod moves to the maximum expansion position of the drum shoe, the double-link and the drum shoe are in a collinear position. The pressure angle of the drum shoe on the double-link is 90° under pressure. At this time, the mechanism will also self-lock. When the drum shoe is under force, only compressive stress is generated on the double-link, and the center piston rod will not be displaced by force in the vertical direction, which can ensure the position accuracy and stability of the drum shoe. On the contrary, the inclined wedge mechanism cannot achieve self-locking when the drum shoe is under pressure. The center piston rod needs to apply axial force to ensure the stability of the drum shoe, and the force requirements for the center piston rod are higher. Therefore, the solution proposed by the present invention can enable the drum shoe to maintain its own stability under pressure by utilizing the principle of self-locking mechanism in the maximum expansion state, thereby reducing the axial force on the center piston rod.

[0026] 4. The present invention takes into account the problem that the short connecting rods on the upper and lower sides of the drum shoe cannot pass through the dead point position of the mechanism when there is no external force driving it. A limit spring is installed at the hinge point of the short connecting rod to apply tension to the connecting rod node. When the central piston rod rises, the double connecting rods tilt inward to drive the drum shoe to retract. The short connecting rod passes through the dead point position of the mechanism under the action of the spring tension, and rotates to one side of the drum shoe under the drive of the double connecting rods, thereby realizing radial contraction of the drum shoe. It has the advantages of being simple and reliable.

[0027] 5. The present invention adopts an asynchronous expansion and contraction scheme. When the drum shoe contracts, the narrow shoe first contracts to the limit position under the drive of the central piston rod, and then continues to rise under the drive of the central piston rod to make radial space for the wide shoe to contract. Finally, the wide shoe continues to contract. This scheme can greatly improve the expansion and contraction ratio of the drum expansion mechanism and expand the scope of application of tires.

[0028] 6. The present invention adopts a single central piston rod, and the guide grooves and bosses on the piston rod can realize the orderly extension and contraction of the wide and narrow drum tiles. Compared with the solution of using two inner and outer piston rods to drive and control the movement of the drum tiles respectively, this solution is simpler and more effective, reduces the control difficulty, and avoids the interference problem between the piston rods. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings, which form part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their description are provided to illustrate the present invention and are not intended to limit the present invention. It should also be understood that these drawings are shown for simplicity and clarity and are not necessarily drawn to scale. The present invention will now be described and explained with additional specificity and detail through the use of the accompanying drawings, in which:

[0030] Figure 1 This is a structural schematic diagram of the central expansion mechanism for asynchronous tire direct pressure vulcanization of the present invention (in the expanded state).

[0031] Figure 2This is a schematic diagram of the contracted state of the center expansion mechanism of the asynchronous tire direct pressure vulcanization of the present invention.

[0032] Figure 3 This is a schematic diagram of the fully expanded state of the asynchronous tire direct pressure vulcanization center expansion drum mechanism of the present invention.

[0033] Figure 4 Schematic diagram of the narrow tile contraction state.

[0034] Figure 5 Schematic diagram of the narrow tile rising state.

[0035] Figure 6 This is a schematic diagram of the asynchronous tire direct pressure vulcanization center expansion drum mechanism of the present invention in a fully contracted state.

[0036] Figure 7 It is a structural schematic diagram of the wide shoe connecting rod mechanism in the present invention.

[0037] Figure 8 It is a structural schematic diagram of the narrow shoe connecting rod mechanism in the present invention.

[0038] Figure 9 This is a structural diagram of the wide tile sliding support in the present invention.

[0039] Figure 10 This is a structural diagram of the narrow tile fixing support in the present invention.

[0040] Figure 11 It is a structural schematic diagram of the central piston rod mechanism in the present invention.

[0041] Figure 12 This is the structural diagram of the central piston rod in the central piston rod mechanism.

[0042] In the figure: 1. Limit chassis, 2. Guide rail pulley, 3. Narrow tile drum frame guide rail slide rod, 4. Narrow tile lower limit spring, 5. Narrow tile drum frame lower support end cover, 6. First narrow tile drum frame lower short connecting rod, 7. Second narrow tile drum frame lower short connecting rod, 8. Narrow tile, 9. Narrow tile drum frame, 10. Narrow tile drum frame middle support, 11. Narrow tile upper limit spring, 12. Narrow tile drum frame upper support end cover, 13. First narrow tile drum frame upper short connecting rod, 14. Second narrow tile drum frame upper short connecting rod, 15. Narrow tile long connecting rod, 16. Narrow tile short connecting rod, 17. Narrow tile fixed support, 1701. Narrow tile support inner spline, 1702. Narrow tile support hinge point, 1703. Narrow tile support guide groove, 18. Narrow tile support end cover;

[0043] 19. Wide tile sliding support, 1901. Wide tile support hinge point, 1902. Wide tile support support plate, 1903. Wide tile support support ring, 20. Wide tile long connecting rod, 21. Wide tile short connecting rod, 22. Wide tile drum frame upper support end cover, 23. First wide tile drum frame upper short connecting rod, 24. Wide tile upper limit spring, 25. Second wide tile drum frame upper short connecting rod, 26. Wide tile drum frame middle support, 27. Wide tile drum frame, 28. Wide drum tile, 29. First wide tile drum frame lower short connecting rod, 30. Wide tile drum frame lower support end cover, 31. Wide tile lower limit spring, 32. Wide tile drum frame guide rail slide, 33. Second wide tile drum frame lower short connecting rod;

[0044] 34. Center piston rod, 3401. External spline, 3402. Center piston rod guide groove, 3403. Boss, 3404. Wedge groove. DETAILED DESCRIPTION

[0045] The technical solutions in typical embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0046] This embodiment provides a novel asynchronous tire direct pressure vulcanization center expansion drum mechanism, including a telescopic mechanism and a driving mechanism. The telescopic mechanism includes a wide tile connecting rod mechanism (see Figure 7 ) and narrow shoe connecting rod mechanism (see Figure 8 The driving mechanism is a central piston rod mechanism (see Figure 11 The drive mechanism includes a central piston rod 34, on top of which is fixedly mounted a narrow shoe mounting support 17. A wide shoe sliding support 19 is mounted on the narrow shoe mounting support 17 and moves axially along the narrow shoe mounting support 17 and the central piston rod 34. The narrow shoe connecting rod mechanism is connected to the narrow shoe mounting support 17, and the wide shoe connecting rod mechanism is connected to the wide shoe sliding support 19. The central piston rod 34 is connected to the vulcanizer's central mechanism drive cylinder, which drives the central piston rod 34 up and down. Figure 1 and Figure 2 The expanded state and the contracted state of the central expansion drum mechanism of the asynchronous tire direct pressure vulcanization of the present invention are respectively given.

[0047] The structure of the wide tile sliding support 19 is as follows Figure 9 As shown, it includes a wide tile support support ring 1903 and a wide tile support support plate 1902. A plurality of wide tile support support plates 1902 are evenly arranged along the circumference of the upper part of the wide tile support support ring 1903. The bottom end of the wide tile support plate 1902 is connected and fixed to the wide tile support support ring 1903. The wide tile support support plate 1902 is provided with two wide tile support hinge points 1901 at upper and lower locations. The number of wide tile support plates 1902 is the same as the guide groove 1703 on the narrow tile fixed support (see Figure 10) are the same in number, and their width and length are the same as the guide groove 1703, so that the wide tile sliding support 19 is mounted on the narrow tile fixed support 17 and can move smoothly up and down along the guide grooves on the narrow tile fixed support 17 and the center piston rod 34.

[0048] The narrow shoe fixed support 17 is connected to the upper part of the central piston rod 34 through the narrow shoe support internal spline 1701, see Figure 10 The narrow shoe fixing support 17 is generally cylindrical, with an internal spline 1701 disposed therein. Several hinge points 1702 are evenly spaced circumferentially at the upper and lower ends of the outer side. Guide grooves 1703 are provided at circumferential intervals at the hinge points. These guide grooves correspond in number and position to the central piston rod guide grooves 3402, ensuring a smooth transition. A narrow shoe support end cap 18 is provided at the top end of the central piston rod 34 to axially locate the narrow shoe fixing support 17.

[0049] The structure of the wide shoe connecting rod mechanism is described in detail below.

[0050] like Figure 7 As shown, the wide-narrow tile connecting rod mechanism includes a wide tile drum frame guide rail slide 32, a wide tile drum 28, a wide tile drum frame 27, a wide tile long connecting rod 20, a wide tile short connecting rod 21, a wide tile drum frame intermediate support 26, and a wide tile side connecting rod. The wide tile drum frame 27 serves as a support plate for the wide tile drum 28 and a mounting plate for the connecting rod support. The wide tile drum frame intermediate support 26, the wide tile drum frame 27, and the wide tile 28 are connected and fixed together from the inside to the outside by screws; the upper and lower parts of the wide tile drum frame 27 are respectively provided with an upper support and a lower support. The wide tile drum frame intermediate support 26 contains two upper and lower connecting rod hinge points, which are hinged to one end of the two wide tile long connecting rods 20 through a pin to form a parallelogram connecting rod mechanism. The wide tile short connecting rod 21 hinges the two long connecting rods together through a pin at the middle position of the wide tile long connecting rod 20, forming a virtual constraint and increasing the rigidity of the connecting rod mechanism. It should also be noted that the wide-wafer short connecting rod 21 also plays a role of limiting and supporting. Figure 2 It can be seen from the contraction state shown that when the wide drum shoe 28 contracts to the limit position and rises, the upper and lower side surfaces of the parallelogram in the middle of the narrow shoe short connecting rod 21 coincide with the side surfaces of the parallelogram formed by the wide shoe long connecting rod 20, which just blocks the wide shoe long connecting rod 20, so that the wide shoe connecting rod mechanism will not continue to move toward the center of the piston rod 34 under the action of gravity, thereby reaching a stable state. Moreover, the angle of the parallelogram in the middle of the wide shoe short connecting rod can affect the contraction limit position of the wide drum shoe 28. By adjusting the angle, interference of the inner sharp corners of the narrow drum shoe can be avoided when the wide drum shoe 28 contracts to the limit position.

[0051] The wide tile side connecting rod includes an upper connecting rod and a lower connecting rod. The upper connecting rod is composed of two short rods of equal length, such as Figure 7The first wide tile drum frame upper short connecting rod 23 and the second wide tile drum frame upper short connecting rod 25, one end of the two upper short connecting rods are hinged together by a pin (see Figure 2 ), the other two ends are respectively hinged to the upper support (upper part) of the wide tile drum frame 27 and the wide tile long connecting rod 20, and the hinge position with the long connecting rod is close to the hinge point of the wide tile drum frame middle support 26. The upper support of the wide tile drum frame 27 is provided with a wide tile drum frame upper support end cover 22 to cover the hinge point of the first wide tile drum frame upper short connecting rod 23. The lower connecting rod includes a first wide tile drum frame lower short connecting rod 29 and two second wide tile drum frame lower short connecting rods 33. The first wide tile drum frame lower short connecting rod 29 is Y-shaped. One end of the first wide tile drum frame lower short connecting rod 29 is hinged to the lower support (lower part) of the wide tile drum frame 27, and the other end (the forked end of the Y-shape) is respectively hinged to the two second wide tile drum frame lower short connecting rods 33. The lower support of the wide tile drum frame 27 is provided with a wide tile drum frame lower support end cover 30 to cover the hinge point of the first wide tile drum frame lower short connecting rod 29. Two second wide tile drum frame lower short connecting rods 33 are symmetrically distributed on either side of the wide tile long connecting rod 20, and their other ends are hinged to the wide tile long connecting rod 20 near the hinge point of the wide tile drum frame middle support 26.

[0052] One end of the wide tile drum frame guide rail slide 32 is screwed to the lower end of the wide tile drum frame 27, and the other end is mounted on two pulleys via a pin to reduce movement friction. The wide tile drum frame guide rail slide 32 is in the shape of a "7" and mainly supports the wide drum tile 28 and guides the wide drum tile 28 to expand and contract radially.

[0053] The wide tile connecting rod mechanism also includes two limit springs: a wide tile lower limit spring 31 and a wide tile upper limit spring 24. Their main function is to use their own tension to cause the upper and lower short links (the first wide tile drum frame upper short link 23, the second wide tile drum frame upper short link 25, the first wide tile drum frame lower short link 29, and the second wide tile drum frame lower short link 33) to cross the dead point of the mechanism when the drum tile retracts, allowing them to rotate inward smoothly, ensuring the smooth movement of the connecting rods. One end of the wide tile upper limit spring 24 is connected to the hinge point of the first wide tile drum frame upper short link 23 and the second wide tile drum frame upper short link 25, and the other end is connected to the wide tile drum frame middle support 26. One end of the wide tile lower limit spring 31 is connected to the first wide tile drum frame lower short link 29, and the other end is connected to the wide tile drum frame guide rail slide 32.

[0054] The structure of the narrow shoe connecting rod mechanism is described in detail below.

[0055] like Figure 8 As shown, the narrow tile connecting rod mechanism includes a narrow tile drum frame guide rail slide rod 3, a narrow tile drum frame 8, a narrow tile drum frame 9, a narrow tile drum frame middle support 10, a narrow tile long connecting rod 15, a narrow tile short connecting rod 16, and a narrow tile side connecting rod.

[0056] The narrow tile drum frame 9 serves as the support plate of the narrow tile drum 8 and the mounting plate of the connecting rod support. The narrow tile drum frame middle support 10, the narrow tile drum frame 9 and the narrow tile drum 8 are connected and fixed together in sequence from the inside to the outside by screws; the upper and lower parts of the narrow tile drum frame 9 are respectively provided with an upper support and a lower support. The narrow tile drum frame middle support 10 includes two upper and lower connecting rod hinge points, which are hinged together with one end of two narrow tile long connecting rods 15 through a pin shaft to form a parallelogram connecting rod mechanism. The narrow tile short connecting rod 16 hinges the two long connecting rods together through a pin shaft in the middle position of the narrow tile long connecting rod 15, forming a virtual constraint to increase the rigidity of the connecting rod mechanism. It should also be noted that the narrow tile short connecting rod 16 also plays a role in limiting and supporting. Figure 2 It can be seen from the contraction state shown that when the narrow drum shoe 8 shrinks to the limit position and rises, the upper and lower side surfaces of the parallelogram in the middle of the narrow shoe short connecting rod coincide with the side surfaces of the parallelogram formed by the narrow shoe long connecting rod 15, which just blocks the narrow shoe long connecting rod 15, so that the narrow shoe connecting rod mechanism will not continue to move toward the center of the piston rod 34 under the action of gravity, thereby reaching a stable state. Moreover, the angle of the parallelogram in the middle of the narrow shoe short connecting rod can affect the contraction limit position of the narrow drum shoe 8. By adjusting the angle, interference of the sharp corners on the inner side of the narrow drum shoe can be avoided when the narrow drum shoe 8 shrinks to the limit position.

[0057] The narrow shoe side connecting rod includes an upper connecting rod and a lower connecting rod. The upper connecting rod is composed of two short rods of equal length, such as Figure 8 The first narrow tile drum frame upper short connecting rod 13 and the second narrow tile drum frame upper short connecting rod 14, one end of the two upper short connecting rods are hinged together by a pin (see Figure 2 ), the other two ends are respectively hinged to the upper support of the narrow tile drum frame 9 and the narrow tile long connecting rod 15, and the hinge position with the long connecting rod is close to the hinge point of the narrow tile drum frame middle support 10. The upper support of the narrow tile drum frame 9 is provided with a narrow tile drum frame upper support end cover 12 to cover the hinge point of the first narrow tile drum frame upper short connecting rod 13. The lower connecting rod includes a first narrow tile drum frame lower short connecting rod 6 and two second narrow tile drum frame lower short connecting rods 7. The first narrow tile drum frame lower connecting rod 6 is Y-shaped. One end of the first narrow tile drum frame lower connecting rod 6 is hinged to the lower support of the narrow tile drum frame 9, and the other end is hinged to the two narrow tile drum frame lower short connecting rods 7. The lower support of the narrow tile drum frame 9 is provided with a narrow tile drum frame lower support end cover 5 to cover the hinge point of the narrow tile drum frame lower connecting rod 6. The two short connecting rods 7 on the lower side of the narrow tile drum frame are symmetrically distributed on both sides of the narrow tile long connecting rod 15, and their other ends are hinged to the narrow tile long connecting rod 15, and the hinge position is close to the hinge point of the middle support 10 of the narrow tile drum frame.

[0058] One end of the narrow tile drum frame guide rail slide 3 is screwed to the lower end of the narrow tile drum frame 9, and the other end is mounted on two pulleys via a pin to reduce movement friction. The narrow tile drum frame guide rail slide 3 is in the shape of a "7", mainly supporting the narrow drum tile 8 and guiding the radial expansion and contraction of the narrow drum tile 8.

[0059] The narrow tile connecting rod mechanism also includes two limit springs, the narrow tile lower limit spring 4 and the narrow tile upper limit spring 11. Their main function is to use their own tension to make the upper and lower short connecting rods (the upper short connecting rod 13 of the first narrow tile drum frame, the upper short connecting rod 14 of the second narrow tile drum frame, the lower short connecting rod 6 of the first narrow tile drum frame and the lower short connecting rod 7 of the second narrow tile drum frame) pass through the dead point position of the mechanism when the drum tile contracts, so that they can rotate inward smoothly to ensure the smoothness of the connecting rod movement.

[0060] One end of the narrow tile upper limit spring 11 is connected to the hinge point of the upper short connecting rods 13 and 14, and the other end is connected to the middle support 10 of the wide tile drum frame. One end of the narrow tile lower limit spring 4 is connected to the lower short connecting rod 6 of the first narrow tile drum frame, and the other end is connected to the narrow tile drum frame guide rail slide rod 3.

[0061] The main difference between the wide tile connecting rod mechanism and the narrow tile connecting rod mechanism is that the circumferential widths of the drum tile (narrow drum tile 8 and wide drum tile 28) and the drum frame (wide tile drum frame 27 and narrow tile drum frame 9) are different, and the rest of the structures (drum frame middle support, long connecting rod, short connecting rod, side connecting rod, guide rail slide rod, etc.) are the same.

[0062] The driving mechanism is described in detail below.

[0063] like Figure 11 As shown, the driving mechanism includes a central piston rod 34, on which a limit chassis 1 is provided. The limit chassis 1 is provided with a T-shaped guide groove, which guides and limits the movement of the guide pulley 2 on the narrow tile drum frame guide rail slide 3 and the wide tile drum frame guide rail slide 32. The central piston rod 34 serves as the driving rod of the central expansion mechanism, and its structure is as follows Figure 12 As shown, the entire structure is a hollow rod with an external spline 3401 and a shoulder at its top. The middle section of the central piston rod 34 is circumferentially provided with several guide grooves 3402. The bottom ends of the guide grooves 3402 are provided with bosses 3403 for limiting and supporting the support. The bosses 3403 are circumferentially provided with several wedge-shaped grooves 3404, the number and position of which correspond to the guide grooves 3402. The lower section of the piston rod 34 is a smooth rod connected to the drive cylinder of the vulcanizer's central mechanism.

[0064] The limiting chassis 1 in this embodiment is installed on the base of the tire shaping and vulcanizing machine, and has an even number of T-guide grooves evenly distributed around its circumference. The wide drum tile and the narrow drum tile cooperate with the T-guide grooves through the pulleys on the guide rail slide rod to realize the motion guidance and axial limitation of the drum tile movement, thereby ensuring the stability and accuracy of the drum tile movement. In addition, an opening is provided on the inner side of the T-guide groove corresponding to the narrow tile connecting rod mechanism. After the narrow drum tile is contracted, it can rise axially from the opening to make radial space for the contraction of the wide drum tile.

[0065] In this embodiment, the number of wide drum tiles 28 and narrow drum tiles 8 is the same, and they are arranged alternately along the circumference. The total number of drum tiles is an even number, generally 12 to 20. In order to achieve the maximum expansion and contraction ratio, through mathematical modeling and analysis of drum tiles, the preferred total number of drum tiles in this embodiment is 16, that is, 8 wide drum tiles 28 and 8 narrow drum tiles 8 (see Figure 3-Figure 6 ). When the mechanism is fully expanded, see Figure 3 The outer surfaces of the wide drum tile 28 and the narrow drum tile 8 form a uniform and complete tire inner surface profile. Through the cooperation of the outer mold, they provide the vulcanization pressure of the radial tread and the axial sidewall for the tire vulcanization. When the mechanism is fully contracted, see Figure 6 , the narrow drum tile 8 is on the top, the wide drum tile 28 is on the bottom, and the maximum circumscribed circle diameter of the mechanism is smaller than the diameter of the bead ring of the finished tire; a tile cutting angle is set between the contact surface of the wide drum tile 28 and the narrow drum tile 8 to prevent the narrow drum tile 8 from shrinking (see Figure 4 ) and the friction between the side of the wide drum tile 28 to ensure smooth movement.

[0066] Figure 1 and Figure 2 The central expansion mechanism of the present invention is shown in its expanded and contracted states. The wide-shoe long connecting rod 20 in the wide-shoe connecting rod mechanism is hinged at one end to the wide-shoe drum frame intermediate support 26, and at the other end to the wide-shoe sliding support 19 on the central piston rod, forming a parallelogram connecting rod mechanism that enables radial movement and support of the wide-shoe drum 28. The wide-shoe side connecting rods are mounted on the long connecting rods and drum frame supports. The planar movement of the wide-shoe long connecting rod 20 drives the side connecting rods to rotate, utilizing the self-locking characteristics of the mechanism to support the side faces of the wide-shoe drum. The narrow-shoe long connecting rod 15 of the narrow-shoe connecting rod mechanism is hinged at one end to the narrow-shoe drum frame intermediate support 10, and at the other end to the narrow-shoe fixed support 17 of the central piston rod, always moving with the central piston rod 34. The axial guide groove 3402 on the center piston rod 34 guides and limits the movement of the wide tile sliding support 19. The boss 3404 at the end of the guide groove 3402 can clamp the wide tile sliding support 19 and move it upward together during the rising process of the piston rod 34, driving the wide tile connecting rod mechanism to move, so that the wide drum tile 28 can shrink radially.

[0067] Figures 3 to 6 The diagram shows the complete drum shoe contraction process of the asynchronous tire direct pressure vulcanization central expansion mechanism of this embodiment. The expansion and contraction of the wide drum shoe 28 and the narrow drum shoe 8 are driven by only one central piston rod 34. The narrow drum shoe 8 is hinged to the piston rod 34 through a connecting rod mechanism via the narrow shoe fixed support 17 and moves with the piston rod 34; the wide drum shoe 28 is hinged to the wide shoe sliding support 19 on the piston rod 34 through a connecting rod mechanism, and the wide drum shoe 28 slides on the piston rod 34.

[0068] Figure 3The center expansion mechanism is in a fully expanded state. The support plate 1902 on the wide tile sliding support 19 is embedded in the guide groove 1703 on the narrow tile fixed support 17, so that the wide tile sliding support 19 and the narrow tile fixed support 17 are horizontally overlapped. The outer surfaces of the wide drum tile 28 and the narrow drum tile 8 form a uniform and complete tire inner surface contour. At this time, the narrow tile long connecting rod 15 and the wide tile long connecting rod 20 are both in a horizontal position, collinear with the narrow tile drum frame middle support 10 and the wide tile drum frame middle support 26 respectively. The upper and lower side connecting rods of the wide and narrow drum tiles are also in a collinear position. When the drum shoe is vulcanized and under pressure, the side connecting rods (the short connecting rod 6 on the lower side of the first narrow tile drum frame, the short connecting rod 7 on the lower side of the second narrow tile drum frame, the short connecting rod 13 on the upper side of the first narrow tile drum frame, the short connecting rod 14 on the upper side of the second narrow tile drum frame, the short connecting rod 23 on the upper side of the first wide tile drum frame, the short connecting rod 25 on the upper side of the second wide tile drum frame, the short connecting rod 29 on the lower side of the first wide tile drum frame, the short connecting rod 33 on the lower side of the second wide tile drum frame) and the long connecting rods (the narrow tile long connecting rod 15 and the wide tile long connecting rod 20) are all in the dead point position of the mechanism. The connecting rods mainly bear compressive stress, which can greatly increase the radial and lateral load-bearing capacity of the drum shoe.

[0069] Figure 4 It is the contraction state of the narrow tile connecting rod mechanism. When the narrow drum tile 8 begins to contract, the center piston rod 34 is driven upward by the oil cylinder, and the narrow tile fixed support 17 that moves with the center piston rod 34 begins to separate from the wide tile sliding support 19, driving the narrow tile long connecting rod 15 to cross the dead point of the mechanism and make a plane rotation. The narrow tile side connecting rods (the short connecting rod 6 on the lower side of the first narrow tile drum frame, the short connecting rod 7 on the lower side of the second narrow tile drum frame, the short connecting rod 13 on the upper side of the first narrow tile drum frame, and the short connecting rod 15 on the upper side of the second narrow tile drum frame) are rotated. The short connecting rod 14 on the narrow tile drum frame also begins to rotate after the long connecting rod 15 rotates, under the tension of the narrow tile upper limit spring 11, passing the dead point of the mechanism. The upper connecting rods of the narrow tile (the first short connecting rod 13 on the narrow tile drum frame and the second short connecting rod 14 on the narrow tile drum frame) rotate inwardly toward the narrow tile drum frame 9, and the lower connecting rods of the narrow tile (the first short connecting rod 6 on the narrow tile drum frame and the second short connecting rod 7 on the narrow tile drum frame) rotate toward the side of the narrow tile guide rail slide 3. The narrow tile guide rail slide 3 is restricted in the T-shaped guide groove of the limiting chassis 1 by the pulley 2. Under the restriction and guidance of the guide groove, the drum tile begins to move inwardly and contract along the T-shaped guide groove. Since a tile cutting angle is set between the contact surface of the wide drum tile and the narrow drum tile, friction between the narrow drum tile and the contact surface of the wide drum tile can be avoided during the contraction process. When the upper and lower sides of the parallelogram formed by the narrow shoe short connecting rod 16 coincide with the sides of the parallelogram formed by the narrow shoe long connecting rod 15, the narrow shoe long connecting rod is locked, preventing it from rotating. At this point, the narrow shoe has just retracted to its limit, and the inner corners of the narrow shoe do not interfere. During the narrow shoe retraction process, the wide shoe sliding support 19 slides relative to the guide groove 3402 on the center piston rod 34, maintaining its axial position, thereby keeping the wide shoe mechanism stationary.

[0070] Figure 5This is the rising state of the narrow shoe connecting rod mechanism. When the narrow drum shoe 8 contracts to the limit position, the narrow shoe short connecting rod 16 just limits the rotation of the narrow shoe long connecting rod 15 and plays a supporting role, so that the narrow shoe mechanism will not continue to move toward the center of the piston rod under the action of gravity, thereby reaching a stable state. Because the limiting chassis has an opening on the inner side of the narrow shoe guide groove, the pulley 2 on the narrow shoe guide rail slide rod 3 can continue to move upward without restriction. Therefore, under the drive of the central piston rod 34, the narrow shoe 8 begins to move upward as a whole, making room for the radial contraction of the wide drum shoe. During this process, the wide shoe sliding support 19 still slides relatively along the guide groove on the central piston rod, and the absolute position remains unchanged, and the wide shoe mechanism remains stationary.

[0071] Figure 6 The center expansion mechanism is in its fully retracted state. When the narrow shoe connecting rod mechanism rises to a certain height driven by the center piston rod 34, the boss 3404 on the piston rod 34 just contacts the wide shoe sliding support 32. At this point, the narrow shoe mechanism has made room for the wide shoe sliding support to retract. The piston rod 34 then continues to rise, and the boss 3404 gets stuck and drives the wide shoe sliding support 32 upward, causing the wide shoe mechanism to begin to retract inward. The retraction process is consistent with that of the narrow shoe. When the center piston rod 34 continues to rise to a certain distance, the wide shoe retracts to its limit position. At this point, the center expansion mechanism is fully retracted, and its maximum circumscribed circle diameter is smaller than the diameter of the finished tire bead ring, allowing the tire to be unloaded smoothly. The expansion process of the center expansion mechanism is the opposite of the above process.

[0072] Although the present invention has been disclosed above in terms of preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solutions of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the scope of protection of the technical solutions of the present invention.

Claims

1. An asynchronous tire direct pressure vulcanization center expansion mechanism, characterized by: It includes a driving mechanism and a telescopic mechanism, the telescopic mechanism includes a wide-shoe connecting rod mechanism and a narrow-shoe connecting rod mechanism; the driving mechanism includes a central piston rod, a narrow-shoe fixed support is fixedly provided on the upper part of the central piston rod, a wide-shoe sliding support is mounted on the narrow-shoe fixed support, the wide-shoe sliding support moves axially along the narrow-shoe fixed support and the central piston rod, and a limited position chassis is provided on the central piston rod below the wide-shoe sliding support; the narrow-shoe connecting rod mechanism is connected to the narrow-shoe fixed support, and the wide-shoe connecting rod mechanism is connected to the wide-shoe sliding support, and the wide-shoe connecting rod mechanism and the narrow-shoe connecting rod mechanism are alternately arranged along the circumferential direction; The wide tile connecting rod mechanism and the narrow tile connecting rod mechanism have the same structure, including a drum tile, a drum frame, an intermediate support of the drum frame, a long connecting rod, a short connecting rod and a side connecting rod; the intermediate support of the drum frame, the drum frame and the drum tile are connected together in sequence, and two upper and lower long connecting rods are hinged on the intermediate support of the drum frame, and the other ends of the two long connecting rods are hinged to the narrow tile fixed support or the wide tile sliding support to form a parallelogram connecting rod mechanism; a short connecting rod is hinged between the two long connecting rods; the side connecting rod includes an upper side connecting rod and a lower side connecting rod, the upper side connecting rod is two short rods of equal length, one end of the two short rods is hinged together, and the other ends of the two short rods are respectively hinged to the upper part of the drum frame and the long connecting rod, the lower side connecting rod includes a Y-shaped connecting rod and two short rods, one end of the Y-shaped connecting rod is hinged to the lower part of the drum frame, and the other end is hinged to the two short rods, and the other end of the two short rods is hinged to the long connecting rod; A guide rail slide is installed at the lower part of the drum frame, a pulley is installed on the guide rail slide, and a guide groove for the pulley is provided on the limit chassis; a lower limit spring is connected between the guide rail slide and the Y-shaped connecting rod; An upper limit spring is connected between the hinge points of the two short rods in the upper connecting rod and the middle support of the drum frame; The circumferential width of the drum shoe and the drum frame in the wide shoe connecting rod mechanism is greater than the circumferential width of the drum shoe and the drum frame in the narrow shoe connecting rod mechanism.

2. The asynchronous tire direct pressure vulcanization center expansion mechanism according to claim 1, characterized in that: The narrow shoe fixing support is connected to the central piston rod through a key.

3. The asynchronous tire direct pressure vulcanization center expansion mechanism according to claim 1, characterized in that: The narrow shoe fixed support and the central piston rod are provided with guide grooves for guiding the axial movement of the wide shoe sliding support; the central piston rod is provided with a boss at the lower part of the guide groove.

4. The asynchronous tire direct pressure vulcanization center expansion mechanism according to claim 3, characterized in that: The boss is provided with wedge-shaped grooves along the circumferential direction, and the number and positions of the wedge-shaped grooves correspond to those of the guide grooves.

5. The asynchronous tire direct pressure vulcanization center expansion mechanism according to claim 1, characterized in that: The wide tile sliding support includes a wide tile support support ring and a wide tile support support plate. The wide tile support support plates are evenly arranged circumferentially in the inner hole of the wide tile support ring. The wide tile support support plates are provided with hinge points for long connecting rods. The wide tile support plates are located in the guide grooves on the narrow tile fixed support.

6. The asynchronous tire direct pressure vulcanization center expansion mechanism according to claim 1, characterized in that: The number of the wide shoe connecting rod mechanisms and the narrow shoe connecting rod mechanisms is the same, the total number is 12 to 20, and the optimal total number is 16.

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