Tire building drum

Abstract

The present invention provides a tire building drum having an attachment surface for receiving a first tire layer and two axially spaced support sections, wherein the first tire layer extends axially across the two support sections. Each support section is provided with a plurality of rotating bodies evenly distributed along the circumferential direction. The plurality of rotating bodies can be driven to rotate and positioned in a first or second position. In the first position, the support section forms a first support surface for supporting the first tire layer, and the first support surface and the attachment surface are radially co-located on the circumferential surface. In the second position, the support section forms an annular recess, and a second support surface is formed on the annular recess, and the second support surface is radially lower than the attachment surface. In this way, the tire building drum provided by the present invention can selectively provide a first or second support surface at the support section by driving the plurality of rotating bodies to rotate, thereby meeting the requirements of the various stages of the high-quality run-flat tire building process.

Description

Technical Field

[0001] The present invention relates to the technical field of tire building equipment, in particular to a tire building drum used in a tire building machine. Background Art

[0002] Existing semi-steel radial tire building machines consist of a belt and tread drum and a tire building drum. The belt and tread drum is used to build the tread assembly. Specifically, tire components such as the belt, cap, and tread layers are sequentially attached to the outer surface of the belt and tread drum to form the tread assembly. The tire building drum is used to build the carcass assembly. Specifically, tire components such as the PA composite layer (composed of an inner liner and sidewall layers) and the cord ply are sequentially attached to the outer surface of the drum. Two tire beads are symmetrically positioned radially outward of the cord ply on the drum. When the tire components located inside the beads are inflated, the tire components located outside the beads are turned up and pressed against the outer surface of the tire components located inside the beads, completing the carcass assembly. Furthermore, the tire building drum is used to combine the tread and carcass assemblies to form a tire blank.

[0003] To ensure continued driving after a tire blowout or air leak, run-flat tires have been gradually adopted by some vehicles. In practice, run-flat tires increase the thickness and rigidity of the tire sidewalls by adding a layer of rubber reinforcement. Specifically, during the run-flat tire blank molding process, the rubber reinforcement is positioned axially inward of the tire bead, between the inner liner and the carcass ply. After the tire blank is molded, the rubber reinforcement extends from the tire bead in the radial direction of the run-flat tire, axially inward of both the sidewall and carcass ply, and axially outward of the inner liner.

[0004] For semi-steel radial one-step tire building machines, the building process and special structure of the above-mentioned run-flat tires have put forward the need for improvement in the structure of the tire building drum. U.S. Patent US5591288A discloses a tire building drum and a method for building tires. Specifically, the tire building drum disclosed in the patent is provided with a drum spacer, and the radial outer surface of the drum spacer is formed with an annular groove for accommodating rubber reinforcements. Due to the presence of this annular groove, it is impossible to form a continuous and flat cylindrical surface on the tire building drum. As a result, after the inner liner is attached to the outer surface of the tire building drum, the inner liner located radially outside the annular groove is not supported, resulting in poor stitching quality of the inner liner at the beginning and end ends located at the groove during the sewing process of the inner liner, which in turn affects the quality of the tire blank.

[0005] In view of this, it is necessary to provide an improved tire building drum to address the problems referred to above. Summary of the Invention

[0006] The present invention aims to provide a tire building drum for forming high-quality run-flat tire blanks.

[0007] To achieve the above-mentioned objectives, the present invention provides a tire building drum for forming a run-flat tire blank, the tire building drum having an attachment surface for receiving a first tire layer, the tire building drum having two axially spaced support sections, the first tire layer extending axially beyond the two support sections, each of the support sections being provided with a plurality of rotatable rotating bodies uniformly distributed along the circumferential direction, the plurality of rotating bodies being driven to rotate and positioned in a first position or a second position, when the plurality of rotating bodies are in the first position, the support section forms a first support surface for supporting the first tire layer, the first support surface and the attachment surface being radially located on the same circumferential surface, when the plurality of rotating bodies are in the second position, the support section forms an annular recess, a second support surface is formed on the annular recess, and the second support surface is radially lower than the attachment surface.

[0008] Furthermore, each of the rotating bodies has a first supporting surface and a second supporting surface. When the multiple rotating bodies are in the first position, the multiple first supporting surfaces form the first supporting surface. When the multiple rotating bodies are in the second position, the multiple second supporting surfaces form the second supporting surface.

[0009] Furthermore, each of the rotating bodies has a first supporting surface and a second supporting surface. When the multiple rotating bodies are in the first position, the multiple first supporting surfaces form the first supporting surface. The supporting section is also provided with a plurality of filling pieces extending axially and evenly spaced in the circumferential direction, and each of the filling pieces has a third supporting surface. When the multiple rotating bodies are in the second position, the second supporting surface and the third supporting surface cooperate to form the second supporting surface, and the second supporting surface is basically continuous in the circumferential direction.

[0010] Furthermore, the plurality of rotating bodies are arranged at intervals in the circumferential direction, and the first supporting surface is discontinuous in the circumferential direction.

[0011] Further, the tire building drum is arranged for receiving rubber reinforcements around the first tire layer at the two axially spaced support sections, respectively.

[0012] Further, before the rubber reinforcement is received around the first tire layer at the two axially spaced support sections, the plurality of rotating bodies are driven to rotate and switch from the first position to the second position.

[0013] Further, after the rubber reinforcement is received around the first tire layer at the two axially spaced support sections, the plurality of rotating bodies are driven to rotate and switch from the first position to the second position.

[0014] For the purpose of the present invention, the present invention also provides a tire building drum, comprising: a main shaft and two half-drums arranged on the main shaft, each of the half-drums comprising: a bead locking unit for radially supporting the bead; a turn-up unit, which is located axially outside the bead locking unit; each of the half-drums also includes a support section, which is located axially inside the bead locking unit; the tire building drum has an attachment surface for receiving a first tire layer, and the first tire layer extends axially over the two support sections; the support section is provided with a plurality of rotating bodies uniformly distributed in the circumferential direction, the rotation axes of the plurality of rotating bodies are parallel to the rotation axis of the tire building drum, each of the rotating bodies has a first support surface and a second support surface, and the plurality of rotating bodies can be driven to rotate and positioned in a first position or a second position to selectively make the first support surface or the second support surface of the plurality of rotating bodies located radially outside the tire building drum.

[0015] Further, when the multiple rotating bodies are in the first position, the multiple first supporting surfaces on the supporting section form a first supporting surface, and the first supporting surface and the attachment surface are radially located on the same circumferential surface; when the multiple rotating bodies are in the second position, the multiple second supporting surfaces on the supporting section form a second supporting surface, and the second supporting surface is radially concave relative to the attachment surface.

[0016] Furthermore, when the multiple rotating bodies are in the first position, the multiple first supporting surfaces on the supporting section form a first supporting surface, and the first supporting surface and the attachment surface are radially located on the same circumferential surface; the supporting section is also provided with a plurality of fillers extending axially and arranged in the circumferential direction, and each of the fillers has a third supporting surface; when the multiple rotating bodies are positioned in the second position, the second supporting surfaces of the multiple rotating bodies and the third supporting surfaces of the filling members jointly form the second supporting surface, and the second supporting surface is radially concave relative to the attachment surface.

[0017] Furthermore, the plurality of rotating bodies and the plurality of filling members are spaced apart from each other in the circumferential direction, and the second supporting surface is substantially continuous.

[0018] Furthermore, the half-drum also includes an actuating assembly for driving the plurality of rotating bodies to rotate synchronously in the same direction, so that the plurality of rotating bodies can be synchronously positioned at the first position or the second position.

[0019] Furthermore, the support section is further provided with an annular support body, and the multiple rotating bodies are evenly distributed and rotatably supported on the support body.

[0020] Furthermore, the actuating assembly is housed in the supporting body and can move axially within the supporting body, and the plurality of rotating bodies are located radially outside the actuating assembly.

[0021] Furthermore, the actuating assembly includes an axially movable sliding body and a plurality of guide members arranged on the sliding body and evenly distributed along the circumferential direction; the plurality of guide members correspond one-to-one to the plurality of rotating bodies, a spiral groove is provided on the rotating body, and one end of each of the guide members is located in the spiral groove.

[0022] Furthermore, the plurality of rotating bodies are arranged at intervals in the circumferential direction, and the first supporting surface is discontinuous in the circumferential direction.

[0023] Furthermore, the support body includes a first support member and a second support member that cooperates with the first support member in a radial direction.

[0024] Furthermore, the plurality of filling members are integrally provided with the second support member or the plurality of filling members are fixedly connected to the second support member.

[0025] Furthermore, an air passage communicating with an external air source is provided in the rotating body, and a plurality of vent holes communicating with the air passage are formed on the second supporting surface.

[0026] Compared with the prior art, the tire building drum provided by the present invention has the following beneficial technical effects:

[0027] The support section of the tire building drum features multiple rotating bodies. These bodies are driven to rotate and selectively and synchronously position themselves in either the first or second position. Different first or second support surfaces are placed on the radially outer surface of the tire building drum, providing either a first or second support surface within the support section. This meets the requirements of each stage of the tire building process and enables the production of high-quality run-flat tire blanks. The first support surface effectively supports the leading and trailing ends of the inner liner layer on the PA composite layer, ensuring the quality of the jointing and stitching of the PA composite layer 40. An annular recessed portion is formed on the second support surface to accommodate the rubber reinforcement, thus meeting the requirements of the run-flat tire building process. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0029] Figure 1Schematic diagram of the three-dimensional structure of the half drum of the tire building drum provided by the present invention Figure 1 ;

[0030] Figure 2 Schematic diagram of the three-dimensional structure of the half drum of the tire building drum provided by the present invention Figure 2 ;

[0031] Figure 3 for Figure 1 A cross-sectional view of a half drum is shown, wherein the first support surface of the rotating body is located radially outside the tire building drum;

[0032] Figure 4 for Figure 2 A cross-sectional view of the half drum shown, wherein the second supporting surface of the rotating body is located radially outside the tire building drum to form an annular recess;

[0033] Figure 5 for Figure 4 A cross-sectional view of a half drum is shown, wherein the inner lining layer and the rubber reinforcement at the annular recess have been placed in the annular recess;

[0034] Figure 6 A schematic diagram of the three-dimensional structure of a single rotating body at a first angle;

[0035] Figure 7 A schematic diagram of the three-dimensional structure of a single rotating body at a second angle;

[0036] Figure 8 A side view of a half drum of a tire building drum of the present invention Figure 1 , wherein the support section is equipped with a rotating body but not with a support member;

[0037] Figure 9 A side view of a half drum of a tire building drum of the present invention Figure 2 , wherein the support section is equipped with a support member but not with a rotating body;

[0038] Figure 10 is a cross-sectional view of the second support member and the filling member;

[0039] Figure 11 for Figure 1 Enlarged view of point H in the middle;

[0040] Figure 12 for Figure 2 Enlarged view of point K in the middle.

[0041] In the picture:

[0042] Main shaft 1; Half drum 2; Rotation axis C1;

[0043] Bead locking unit 10; support block 11; tapered piston 12;

[0044] Turn-up unit 20; turn-up rod 21; support plate 22; turn-up drive assembly 23; rolling element 24; guide plate 25; circumferential surface D; guide body 26;

[0045] Support section 30; rotating body 31; rotation axis C2; first support surface F1; second support surface F2; annular recess R; spiral groove G; first support surface S1; second support surface S2; first support member 32; second support member 33; filling member 34; third support surface N;

[0046] PA composite layer 40; rubber reinforcement 50;

[0047] Actuating assembly 70; sliding body 71; guide member 72;

[0048] Gap M; vent X; airway L;

[0049] Outer shaft 80. DETAILED DESCRIPTION

[0050] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present invention and corresponding drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0051] like Figures 1 to 2 As shown, the present invention provides a tire building drum for use in a semi-steel radial tire one-step tire building machine to build run-flat tire blanks. It should be noted that the tire building machine also includes a belt drum (not shown) for forming the tread assembly, a tread component feeding device (not shown) for conveying tread components, a carcass component feeding device (not shown) for conveying carcass components, and a transfer device or rolling station located between the belt drum and the tire building drum. The specific structure of the tire building drum is described in detail below.

[0052] like Figures 1 to 5 、 Figures 11 to 12 As shown, the tire building drum comprises: a main shaft 1 and two half drums 2 sleeved outside the main shaft 1. It should be noted that, Figures 1 to 5Only the main shaft 1 of the tire building drum and one drum half 2 mounted on it are shown. Specifically, the tire building drum has a rotation axis C1, and the two drum halves 2 can rotate circumferentially about the rotation axis C1 and can also move toward or away from each other along the main shaft. Furthermore, each drum half 2 includes a bead locking unit 10 for radially supporting the tire bead (not shown); a turn-up unit 20 located axially outward of the bead locking unit 10; an annular guide 26 that is axially movable and cooperates with the turn-up unit 20; and a support section 30 located axially inward of the bead locking unit 10. The following details the structure of each component of the drum half 2.

[0053] like Figure 3 As shown, the turn-up unit 20 includes a plurality of turn-up rods 21 evenly distributed along the circumference, configured to turn up tire components located axially outside the tire bead (not shown) against tire components located axially inside the tire bead. The tire components include a PA composite layer 40 (composed of an inner liner and sidewall layers) and at least one carcass ply, which are sequentially attached to the outside of the tire building drum. When the turn-up rods 21 are in their initial position, the rods 21 extend axially along the main shaft 1, spaced apart from one another. An annular guide body 26 is mounted at the front ends of the rods 21 and fills the spaces between the rods 21. This creates a substantially continuous and flat circumferential surface D located axially outside the tire bead and supporting a portion of the PA composite layer 40. This circumferential surface D, formed by the turn-up rods 21 and the guide body 26, serves as a portion of the tire building drum's attachment surface. When the PA composite layer 40 is arranged as the first tire layer on the attachment surface of the tire building drum, the PA composite layer 40 axially extends over two axially spaced support sections on the tire building drum.

[0054] like Figures 1 to 5 As shown, the support section 30 is provided with a plurality of rotating bodies 31 evenly distributed along the circumferential direction, and the rotation axes C2 of the plurality of rotating bodies 31 are parallel to the rotation axis C1 of the tire building drum. The plurality of rotating bodies 31 have the same structure and can rotate synchronously in the same direction by a certain angle. Each rotating body 31 can provide at least two different support surfaces. In this embodiment, the plurality of rotating bodies 31 can be driven to rotate and synchronously positioned in a first position or a second position. Each rotating body 31 includes a first support surface F1 and a second support surface F2. Specifically, when the plurality of rotating bodies 31 are in the first position, the first support surface F1 is located radially outward of the tire building drum. When the plurality of rotating bodies 31 are in the second position, the second support surface F2 is located radially outward of the tire building drum. The first support surface F1 is approximately flat, and the second support surface F2 is concave.

[0055] like Figure 1 、 Figure 3As shown, when the multiple rotating bodies 31 at the support section 30 of the tire building drum are in the first position, the multiple first supporting surfaces F1 of the multiple rotating bodies 31 at the support section 30 can form a first supporting surface S1 for supporting the PA composite layer 40 in the circumferential direction. The first supporting surface S1 and the circumferential surface D are located on the same circumferential surface in the radial direction, and the two together serve as the attachment surface for attaching the PA composite layer 40. The PA composite layer 40 includes an inner liner located in the middle area and sidewall layers located on both sides of the inner liner. The thickness of the sidewall layer is thicker than that of the inner liner. It should be noted that the attachment surface S1 is located on the same circumferential surface as the circumferential surface D. Figures 3 to 5 The PA composite layer shown in the figure is a simplified diagram. Furthermore, because the multiple rotating bodies 31 are spaced apart circumferentially, the first support surface S1 is discontinuous in the circumferential direction. However, during the process of attaching the PA composite layer 40 to the tire building drum and sewing the tail end joint, the first support surface S1 can effectively support the leading end and the end-to-end butted portion of the PA composite layer 40, thereby ensuring the quality of the tail end butt joint and sewing of the PA composite layer 40, and thus enabling the formation of a high-quality run-flat tire blank.

[0056] The tire building drum of the present invention can be used to build a run-flat tire blank. Specifically, the tire building drum is arranged to receive the rubber reinforcement 50 around the PA composite layer 40 at the two axially spaced support sections 30. Figure 2 、 Figure 4 、 Figure 5 and Figure 12 As shown, the multiple rotating bodies 31 in the support section 30 of the tire building drum are in the second position. The multiple second supporting surfaces F2 of the multiple rotating bodies 31 in the support section 30 form a second supporting surface S2 for supporting and accommodating the rubber reinforcement. The second supporting surface S2 is radially lower than the attachment surface. The multiple rotating bodies 31 in the support section 30 cooperate to form an annular recess R that matches the cross-sectional shape of the rubber reinforcement 50. The annular recess R accommodates the rubber reinforcement 50, ensuring that the radially outer surface of the rubber reinforcement 50 on the tire building drum is substantially flush with the outer surface of the PA composite layer 40 located outside the annular recess R. This ensures a substantially flat surface for the carcass ply, ensuring accurate splicing of the carcass ply ends. Furthermore, the PA composite layer 40 attached to the tire building drum is only partially indented in the support section 30 to generate localized stretching and then indented to be accommodated in the annular recess R. The rubber reinforcement 50 adheres to the radially outer side of the PA composite layer 40 and is completely accommodated within the recess R. In this way, while ensuring that the rubber reinforcement 50 can be accommodated in the recessed portion R, the risk of wrinkles or other irregular tensile deformation forming on the remaining portion of the PA composite layer 40 attached to the tire building drum is reduced. In this way, the tire building drum is ensured to be able to form high-quality run-flat tire blanks.

[0057] like Figures 3 to 7As shown, the half drum 2 also includes an actuating assembly 70 for driving the multiple rotating bodies 31 to rotate synchronously in the same direction. The actuating assembly 70 can position the multiple rotating bodies 31 synchronously in the first position and the second position. Specifically, the actuating assembly 70 includes an axially movable sliding body 71 and a plurality of guide members 72 provided on the sliding body 71 and uniformly distributed along the circumferential direction. Furthermore, the plurality of guide members 72 are matched with the plurality of rotating bodies 31 in a one-to-one correspondence, the plurality of guide members 72 are at least partially located on the radially outer side of the sliding body 71, the plurality of guide members 72 are fixedly connected to the sliding body 71 or the plurality of guide members 72 are inserted into the sliding body 71. Accordingly, as Figure 7 As shown, a spiral groove G is formed in the rotating body 31, and one end of the guide member 72 is located within the spiral groove G. Thus, when the sliding body 71 moves axially along the main shaft 1, the multiple guide members 72 follow the sliding body 71 in axial movement. Because one end of the multiple guide members 72 is located within the spiral groove G, as the multiple guide members 72 move axially, one end of the multiple guide members also slides within the spiral groove G of the multiple rotating bodies 31, thereby driving the multiple rotating bodies 31 to rotate synchronously in the same direction to switch the support surface.

[0058] In this way, by driving the plurality of rotating bodies 31 to rotate, the support section 30 can selectively provide a first support surface S1 or a second support surface S2 to meet the requirements of the molding process at each stage of the tire molding process.

[0059] In addition, the axial movement of the sliding body 71 along the main shaft 1 can be achieved by pneumatic, hydraulic or electric driving methods. These driving methods are common knowledge in the field and will not be described in detail here.

[0060] Further, if Figures 3 to 5 As shown, the support section 30 also includes an annular support body, with multiple rotating bodies 31 evenly distributed and rotatably supported on the support body. In this embodiment, the sliding body 71 is annular and similar to a piston. The sliding body 71 is housed within the support body and can move axially within the support body. In this embodiment, the support body includes a first support member 32 and a second support member 33 that cooperates with the first support member 32. The first and second support members 32, 33 cooperate with each other in the radial direction and together form the support body. The multiple rotating bodies 31 are located radially outward of the sliding body 71.

[0061] Next, combine Figures 3 and 4 , describing in detail how the actuating assembly 70 drives the rotating body 31 to position different supporting surfaces on the radial outside of the tire building drum.

[0062] like Figure 3As shown, as the sliding body 71 moves axially along the main shaft 1 toward the bead lock unit 10, the multiple rotating bodies 31 synchronously rotate about their respective rotation axes C2 by a predetermined angle in a first direction (not shown). When the sliding body 71 moves to a predetermined axial position, the multiple rotating bodies 31 are positioned in the first position, such that the first support surfaces F1 of the multiple rotating bodies 31 are located radially outward of the tire building drum. As a result, the aforementioned first support surface S1 is formed at the support section 30.

[0063] like Figure 4 As shown, as the sliding body 71 moves axially along the main shaft 1 toward the side away from the bead lock unit 10, the multiple rotating bodies 31 synchronously rotate about their respective rotation axes C2 by a predetermined angle in a second direction (not shown), opposite to the first direction. After the sliding body 71 has moved to a predetermined axial position, the multiple rotating bodies 31 are positioned in the second position, such that the second support surfaces F2 of the multiple rotating bodies are located radially outward of the tire building drum. This allows the support section 30 to form the aforementioned second support surface S2, which has an annular recess R formed thereon that matches the cross-sectional shape of the rubber reinforcement 50.

[0064] Further, if Figure 8 As shown, in order to avoid interference between the multiple rotating bodies 31 during synchronous rotation, the multiple rotating bodies 31 are spaced apart from each other, that is, when the multiple rotating bodies 31 are in the first position or the second position, a gap M is left between adjacent rotating bodies 31.

[0065] Further, if Figures 2 to 5 、 Figures 9 to 12 As shown, the support body further includes a plurality of axially extending filler members 34 evenly spaced in the circumferential direction. Specifically, the filler members 34 have a third support surface N, the configuration of which is identical to that of the second support surface F2. When the plurality of rotating bodies 31 are positioned in the second position, a substantially circumferentially continuous and closed second support surface S2 is formed on the support section 30. In fact, the second support surface S2 is formed by the second support surfaces F2 of the plurality of rotating bodies 31 and the third support surfaces N of the filler members 34. This allows the rubber reinforcement 50 to be more completely accommodated within the annular recess R and to be well supported.

[0066] Since the support section 30 forms a basically continuous and closed second support surface S2 in the circumferential direction, when the PA composite layer 40 is recessed into the annular recess R by external force (direct pressing or negative pressure adsorption, etc.), it can reduce the indentation on the PA composite layer 40 originally caused by the existence of the gap M, or avoid the risk of bubbles being easily generated between the PA composite layer 40 and the rubber reinforcement 50 due to the PA composite layer 40 being sunken into the gap due to force, and the risk of the PA composite layer 40 at the annular recess R being stretched again during inflation, thereby effectively improving the quality of the tire carcass assembly molding and improving the product qualification rate.

[0067] Furthermore, Figures 6 and 7 As shown in the embodiment, an axially extending air channel L and a plurality of vent holes X are defined within the rotating body 31 and communicate with the air channel L and radially extend to the second support surface F2. In this way, a portion of the PA composite layer 40 can fit within the annular recess R under negative pressure.

[0068] In addition, combined Figures 1 to 5 Describe in detail the specific structure of other components in the tire building drum and their mutual coordination relationship.

[0069] The half drum 2 further includes an outer shaft 80 which is sleeved outside the main shaft 1 and is coaxially arranged with the main shaft 1 .

[0070] Furthermore, the turn-up unit 20 includes a support plate 22, a turn-up drive assembly 23, and a guide plate 25. One end of the turn-up rod 21 is pivotally connected to the support plate 22, while the other end of the turn-up rod 21 is rotatably connected to a rolling element 24 located outside the guide plate 25. The turn-up drive assembly 23 is used to drive the support plate 22 to move axially along the outer shaft 80, thereby driving the turn-up rod 21 and rolling element 24. The guide plate 25 is sleeved and fixedly connected to the outer shaft 80. The rolling element 24 is configured to roll with the outer circumferential arcuate surface of the guide plate 25.

[0071] Furthermore, the bead locking unit 10 includes: a plurality of circumferentially arranged support blocks 11, which are disposed between the guide plate 25 and the first support member 32; and a tapered piston 12, whose radial outer side forms a conical surface with the radial inner side of the support blocks 11. Axial movement of the tapered piston 12 can drive radial movement of the support blocks 11.

[0072] Next, combine Figures 3 to 5 The invention also provides a molding process for a run-flat tire embryo in a one-step tire building machine, and describes in detail the working process of the tire building drum of the present invention.

[0073] In the first stage, the PA composite layer 40 is attached to the tire building drum. Figure 3As shown, the turn-up rods 21 are in a starting position, extending axially along the main shaft 1. The turn-up rods 21 cooperate with the guide body 26 to form a substantially continuous and flat circumferential surface D axially outside the bead lock unit 10 for supporting a portion of the PA composite layer 40. Simultaneously, the multiple rotating bodies 31 in the support section 30 are driven by the actuating assembly 70 to be positioned in a first position, such that the first supporting surfaces F1 of the multiple rotating bodies 31 are located radially outside the tire building drum, forming a first supporting surface S1 in the circumferential direction. The first supporting surface S1 and the circumferential surface D together form an attachment surface for attaching the PA composite layer 40 to the tire building drum, thereby receiving the PA composite layer 40.

[0074] In the second stage, the two rubber reinforcements 50 need to be attached to the designated positions on the radial outside of the PA composite layer 40. It should be noted that the above-mentioned designated position refers to the position radially aligned with the annular recess R. In this embodiment, after the two rubber reinforcements 50 are attached to the designated positions on the radial outside of the PA composite layer 40, the multiple rotating bodies 31 are switched from the above-mentioned first position to the second position. Then, a part of the PA composite layer 40 is accommodated in the annular recess R together with the rubber reinforcement 50, and it is ensured that the radial outer surface of the rubber reinforcement 50 is substantially flush with the outer surface of the PA composite layer 40 located outside the designated position. Thus, the cord layer is smoothly attached to the outer surface of the PA composite layer 40 and the rubber reinforcement 50, ensuring that the end-to-end splicing of the cord layer is accurate. In this way, the tire building drum provided by the present invention can be used in a one-step tire building machine to form high-quality tire body components, and then a high-quality run-flat tire embryo can be formed. As Figures 4 and 5 As shown, the turn-up rod 21 is still in the starting position, while the multiple rotating bodies 31 in the support section 30 are driven by the actuating assembly 70 to the second position, so that the second support surfaces F2 of the multiple rotating bodies 31 are located radially outside the tire building drum. As a result, the multiple rotating bodies 31 in the support section 30 and the filler 34 can cooperate to form an annular recess R that matches the cross-sectional shape of the rubber reinforcement 50, and the annular recess R has a substantially continuous second support surface S2. By applying an external force (e.g., negative pressure adsorption) to the PA composite layer 40 and the rubber reinforcement 50 at designated positions, the PA composite layer 40 and the rubber reinforcement 50 in the annular recess R are accommodated in the annular recess R.

[0075] Regarding the second stage, there is an alternative embodiment (not shown). That is, before the two rubber reinforcements 50 are attached to the designated positions radially outside the PA composite layer 40, the multiple rotating bodies 31 are switched from the first position to the second position. Then, an external force (such as negative pressure adsorption) is applied to cause the PA composite layer 40 at the designated position to be recessed and accommodated in the annular recess R. Then, the rubber reinforcement 50 is attached to the radially outer side of the PA composite layer 40 in the annular recess R, ensuring that the radial outer surface of the rubber reinforcement 50 is substantially flush with the outer surface of the PA composite layer 40 outside the designated position.

[0076] Compared with the prior art, the tire building drum provided by the present invention has the following beneficial technical effects:

[0077] The tire building drum's support section features multiple rotating bodies. By driving these rotating bodies to rotate, they selectively provide a primary or secondary support surface within the support section, meeting the requirements of each stage of the tire building process and enabling the production of high-quality run-flat tire blanks. The primary support surface effectively supports the leading and trailing ends of the inner liner layer on the PA composite layer, ensuring the quality of the jointing and stitching of the PA composite layer 40. The secondary support surface also features an annular recessed portion for accommodating the rubber reinforcement, thus meeting the requirements of the run-flat tire building process.

[0078] The specific examples described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A tire building drum for forming a run-flat tire blank, characterized by: The tire building drum has an attachment surface for receiving a first tire layer, the tire building drum has two axially spaced support sections, the first tire layer axially extends over the two support sections, each of the support sections is provided with a plurality of rotatable rotating bodies uniformly distributed along the circumferential direction, the plurality of rotating bodies can be driven to rotate and positioned in a first position or a second position, when the plurality of rotating bodies are in the first position, the support section forms a first support surface for supporting the first tire layer, the first support surface and the attachment surface are radially located on the same circumferential surface, when the plurality of rotating bodies are in the second position, the support section forms an annular recessed portion, a second support surface is formed on the annular recessed portion, and the second support surface is radially lower than the attachment surface; Each of the rotating bodies has a first supporting surface and a second supporting surface. When the multiple rotating bodies are in the first position, the multiple first supporting surfaces form the first supporting surface. When the multiple rotating bodies are in the second position, the multiple second supporting surfaces form the second supporting surface.

2. A tire building drum according to claim 1, characterized in that: The support section is also provided with a plurality of filling pieces extending axially and evenly spaced in the circumferential direction, each of the filling pieces having a third support surface; when the plurality of rotating bodies are in the second position, the second support surface and the third support surface cooperate to form the second support surface, and the second support surface is basically continuous in the circumferential direction.

3. A tire building drum according to any one of claims 1 to 2, characterized in that: The plurality of rotating bodies are spaced apart in the circumferential direction, and the first supporting surface is discontinuous in the circumferential direction.

4. A tire building drum according to any one of claims 1 to 2, characterized in that: The tire building drum is arranged for receiving rubber reinforcements around the first tire layer at the two axially spaced support sections, respectively.

5. A tire building drum according to claim 4, characterized in that: Before receiving the rubber reinforcement around the first tire layer at the two axially spaced support sections, the plurality of rotating bodies are driven to rotate and switch from the first position to the second position.

6. A tire building drum according to claim 4, characterized in that: After receiving the rubber reinforcement around the first tire layer at the two axially spaced support sections, the plurality of rotating bodies are driven to rotate and switch from the first position to the second position.

7. A tire building drum comprising: A main shaft and two half-drums arranged on the main shaft, each half-drum comprising: a bead locking unit for radially supporting the bead; a turn-up unit located axially outside the bead locking unit; characterized in that: Each of the half-drums further comprises a support section, which is located axially inside the bead locking unit; the tire building drum comprises an attachment surface for receiving a first tire layer, the first tire layer axially extending beyond the two support sections; the support section is provided with a plurality of rotating bodies uniformly distributed in the circumferential direction, the rotation axes of the plurality of rotating bodies being parallel to the rotation axis of the tire building drum, each of the rotating bodies comprising a first support surface and a second support surface, the plurality of rotating bodies being driven to rotate and positioned in a first position or a second position, so as to selectively cause the first support surface or the second support surface of the plurality of rotating bodies to be located radially outside the tire building drum; When the multiple rotating bodies are in the first position, the multiple first supporting surfaces on the supporting section form a first supporting surface, and the first supporting surface and the attachment surface are radially located on the same circumferential surface; when the multiple rotating bodies are in the second position, the multiple second supporting surfaces on the supporting section form a second supporting surface, and the second supporting surface is radially concave relative to the attachment surface.

8. The tire building drum according to claim 7, characterized in that: The support section is also provided with a plurality of fillers extending axially and arranged in a circumferential direction, each of the fillers having a third support surface; when the plurality of rotating bodies are positioned at the second position, the second support surfaces of the plurality of rotating bodies and the third support surfaces of the fillers jointly form the second support surface.

9. A tire building drum according to claim 8, characterized in that: The plurality of rotating bodies and the plurality of filling members are spaced apart from each other in a circumferential direction, and the second supporting surface is substantially continuous.

10. A tire building drum according to any one of claims 7 to 9, characterized in that: The half-drum further includes an actuating assembly for driving the plurality of rotating bodies to rotate synchronously in the same direction, so that the plurality of rotating bodies can be synchronously positioned at the first position or the second position.

11. A tire building drum according to claim 10, characterized in that: The support section is further provided with an annular support body, and the multiple rotating bodies are evenly distributed and rotatably supported on the support body.

12. A tire building drum according to claim 11, characterized in that: The actuating assembly is accommodated in the supporting body and can move axially within the supporting body. The plurality of rotating bodies are located radially outside the actuating assembly.

13. The tire building drum according to claim 10, characterized in that: The actuating assembly includes an axially movable sliding body and a plurality of guide members arranged on the sliding body and evenly distributed along the circumferential direction; the plurality of guide members correspond one-to-one to the plurality of rotating bodies, a spiral groove is provided on the rotating body, and one end of each of the guide members is located in the spiral groove.

14. A tire building drum according to any one of claims 7 to 8, characterized in that: The plurality of rotating bodies are spaced apart in the circumferential direction, and the first supporting surface is discontinuous in the circumferential direction.

15. The tire building drum according to claim 11, characterized in that: The support body includes a first support member and a second support member matched with the first support member in a radial direction.

16. The tire building drum according to claim 15, characterized in that: The plurality of filling members are integrally provided with the second supporting member or the plurality of filling members are fixedly connected to the second supporting member.

17. A tire building drum according to any one of claims 7 to 8, characterized in that: An air passage communicating with an external air source is provided in the rotating body, and a plurality of vent holes communicating with the air passage are formed on the second supporting surface.

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