Locking device and tire building drum

Abstract

The present invention discloses a locking device which is arranged on the main shaft of a tire building drum. The locking device includes a pressing member and a first cylinder body which are sequentially arranged from the inside to the outside around the main shaft. The first cylinder body is provided with a first cavity. There is a force transmission medium in the first cavity and the first cavity extends towards the pressing member. The locking device further includes a first piston accommodated in the first cavity. The first piston can move in the first cavity to compress the force transmission medium to generate pressure. The pressure acts on the pressing member to lock the main shaft. When the pressure disappears, the pressing member and the first piston reset. The present invention also discloses a tire building drum having the aforementioned locking device. Compared with the prior art, the locking device of the present invention has a better clamping effect.

Description

Technical Field

[0001] The present invention relates to the technical field of tire building equipment, in particular to a locking device and a tire building drum with the locking device. Background Art

[0002] Chinese Patent Publication No. CN102036810B discloses a tire building drum for building unvulcanized tires, which includes a central drum shaft and two drum halves, wherein the two drum halves include a cylindrical component arranged around the central drum shaft and a folding arm unit, and the cylindrical component is provided with a locking mechanism, and the locking mechanism can engage or disengage with the central drum shaft. When the locking mechanism is engaged with the central drum shaft, the folding arm unit can move axially relative to the cylindrical component. The above patent discloses that the cylindrical component can be engaged or disengaged with the central drum shaft through the engagement of a thread, thereby achieving the axial overall movement of the drum half and the axial movement of the folding arm unit relative to the cylindrical component (turn-over action).

[0003] However, since the locking mechanism on the cylindrical component and the center drum shaft are threaded together, during the tire molding process, there are problems with unreliable engagement and easy slippage, resulting in the locking mechanism being unable to hold the center drum shaft tightly, and thus causing the tire molding drum to be unable to complete the corresponding process. Summary of the Invention

[0004] The purpose of the present invention is to provide a locking device with good clamping effect and a tire building drum with the locking device.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] A locking device is arranged on the main shaft of a tire forming drum. The locking device includes a pressure piece and a first cylinder body arranged in sequence from the inside to the outside around the main shaft. The first cylinder body is provided with a first cavity. The first cavity contains a force transmission medium and the first cavity extends toward the pressure piece. The locking device also includes a first piston accommodated in the first cavity. The first piston can move in the first cavity to compress the force transmission medium to generate pressure. The pressure acts on the pressure piece to lock the main shaft.

[0007] Furthermore, the force transmission medium is liquid plastic.

[0008] Furthermore, the locking device also includes a first elastic member sleeved on the main shaft and arranged close to the pressing member. The pressure causes the pressing member to press against the first elastic member, and the first elastic member holds the main shaft tightly after being deformed.

[0009] Further, the first piston divides the first cavity into a first chamber and a second chamber. The second chamber extends toward the pressing member, and the force transmission medium is located in the second chamber. The first piston can move radially within the first chamber to compress the force transmission medium in the second chamber.

[0010] Further, the first piston includes a first part and a second part. The first part and the second part divide the first cavity into a first chamber, a second chamber, and a third chamber. The second chamber extends toward the pressing member. The second part and the force transmission medium are both located in the second chamber, and the first part is located in the first chamber and the third chamber.

[0011] Further, the first part is provided with a recess for clamping one end of the second part. The recess can limit one end of the second part, and the first part pushes the second part to move axially along the main axis through the recess to compress the force transmission medium in the second chamber.

[0012] Further, the pressing member is provided with a radially recessed groove.

[0013] Further, the second chamber is located within the first inner cylinder and communicates with the groove.

[0014] A tire building drum, comprising: a main shaft, a lead screw located within the main shaft, two half drums disposed around the main shaft, and connecting components that respectively connect the two half drums to the lead screw.

[0015] Each half drum includes an outer shaft sleeve sleeved on the main shaft, an overturning driving device, the locking device as described above, and an overturning unit having a plurality of overturning rods distributed circumferentially and pivotally connected to one end of the overturning driving device. When the locking device locks the main shaft, the overturning driving device drives the overturning rods to perform overturning; when the locking device releases the main shaft, the lead screw rotates and sequentially drives the connecting components and the two half drums to move axially relative to each other.

[0016] Further, the locking device has the same structure as the overturning driving device.

[0017] Furthermore, the locking control of the turn-up drive device and the releasing control of the locking device are realized by the same air source or hydraulic source, and the releasing control of the turn-up drive device and the locking device are realized by the same air source or hydraulic source. When the locking device locks the main shaft, the turn-up drive device releases the outer sleeve to allow the turn-up drive device to move axially along the outer sleeve; when the locking device releases the main shaft, the turn-up drive device locks the outer sleeve to allow the two half-drums to move axially relative to or away from each other.

[0018] Furthermore, the connecting assembly includes two transmission nuts respectively located on both sides of the lead screw and threadedly connected to the lead screw, and a connecting piece fixedly connecting the transmission nuts and the half drum.

[0019] Furthermore, the turn-up driving device includes a second cylinder body, a second cavity and a second piston accommodated in the second cavity are formed in the second cylinder body, and the second piston is fixedly connected to the first cylinder body.

[0020] Furthermore, the turn-up driving device further includes an annular connecting plate fixedly connected to the second cylinder body, and the connecting plate is pivotally connected to one end of the turn-up rod.

[0021] The beneficial effects of the present invention are as follows: by arranging the first cylinder body, the first piston, the first chamber and the second chamber, when the first piston is driven by air pressure to move in the first cylinder body, the first piston can compress the force transmission medium in the second chamber. After the force transmission medium is compressed, huge pressure is instantly generated, and the pressure can reach hundreds of MPa. This pressure can directly act on the pressure part, so that the pressure part holds the main shaft tightly. Therefore, under the same pneumatic driving force conditions, the pressure generated by the linkage structure of the present invention is greater than that of the simple air pressure, thereby having a better holding effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] 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:

[0023] Figure 1 It is a first state sectional view of tire building drum embodiment 1 of the present invention.

[0024] Figure 2 It is a second state sectional view of tire building drum embodiment 1 of the present invention.

[0025] Figure 3 It is a first state sectional view of tire building drum embodiment 2 of the present invention.

[0026] Figure 4It is a second-state cross-sectional view of Embodiment 2 of the tire building drum of the present invention.

[0027] Figure 5 is Figure 1 a partial enlarged view of.

[0028] Figure 6 It is a cross-sectional view of Embodiment 1 of the locking device of the present invention.

[0029] Figure 7 It is a cross-sectional view of Embodiment 2 of the locking device of the present invention.

[0030] Figure 8 It is a cross-sectional view of Embodiment 3 of the locking device of the present invention. Detailed Description of the Invention

[0031] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements with the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present invention, and should not be construed as limiting the present invention.

[0032] The technical solutions of the present invention will be further described below in conjunction with the drawings and specific embodiments.

[0033] As Figures 1 to 5 shown, the present invention discloses a tire building drum 100, which includes a main shaft 1, a middle ring (not shown) sleeved on the main shaft 1, and two half drums that are substantially symmetric with respect to the middle ring and arranged around the main shaft 1. Each half drum includes two outer shaft sleeves 3 sleeved on the main shaft 1 that are symmetric with respect to the middle ring. The two outer shaft sleeves 3 are respectively located on both sides of the middle ring and can move axially along the main shaft 1. It should be noted that Figures 1 to 4 only the half-drum structure of the tire building drum 100 is shown.

[0034] Furthermore, the tire building drum 100 further includes a lead screw 4 located inside the main shaft 1 and coaxially arranged with the main shaft 1, and a connection assembly connecting the lead screw 4 and the half drums. The rotation of the lead screw 4 can sequentially drive the connection assembly and the two half drums to move axially relative to each other along the main shaft 1. The connection assembly includes two drive nuts 5 respectively located on both sides of the lead screw and threadedly connected to the lead screw 4, and a plurality of connecting members 6 fixedly connecting the drive nuts 5 and the half drums. Among them, on both sides of the center of the tire building drum 100, the thread directions of the lead screw 4 are opposite and the pitches are equal. The two half drums are respectively fixedly connected to the corresponding drive nuts 5 through the connecting members 6. Therefore, the rotation of the lead screw 4 can drive the two drive nuts 5 to move towards or away from each other, thereby driving the connecting members 6 and the two half drums to move towards or away from each other. It should be particularly noted that the main shaft 1 is provided with a keyway (not labeled) so that the connecting member 6 can extend into the main shaft 1 from the keyway to be connected to the drive nut 5.

[0035] As Figure 1 and Figure 5 shown, each semi-drum includes a locking device 7 disposed on the main shaft 1 and away from the middle ring, a reverse wrapping rod guide disc 8 disposed near the middle ring, a reverse wrapping driving device 2 located between the locking device 7 and the reverse wrapping rod guide disc 8, a bead support unit 35 and a bead abutting unit 36 located between the reverse wrapping rod guide disc 8 and the middle ring, and a reverse wrapping unit having a plurality of reverse wrapping rods 9 distributed in the circumferential direction. Among them, the locking device 7 is fixedly connected to the reverse wrapping driving device 2, and the connecting member 6 is fixedly connected to the reverse wrapping driving device 2. In the reverse wrapping process of forming a tire on the tire forming drum 100, the bead support unit 35 can be used to circumferentially fix the bead of the tire (not shown), and the bead abutting unit 36 is used to abut against one end face of the bead away from the reverse wrapping rod 9, so that the position of the bead does not move during the reverse wrapping process.

[0036] As Figure 1 and Figure 5 shown, the reverse wrapping rod 9 is provided with a first end 91 and a second end 92. The first end 91 is pivotally connected to the reverse wrapping driving device 2, and the second end 92 is freely placed on the reverse wrapping rod guide disc 8. Further, the reverse wrapping rod 9 includes a first state substantially parallel to the main shaft 1 and a second state intersecting the main shaft 1 at an angle. When the second end 92 of the reverse wrapping rod 9 gradually moves away from the main shaft 1, the reverse wrapping rod 9 can be switched from the first state to the second state, so as to reverse wrap the components of the tire. When the second end 92 of the reverse wrapping rod 9 gradually approaches the main shaft 1, the reverse wrapping rod 9 can be switched from the second state to the first state, so as to realize the reset of the reverse wrapping rod 9 and prepare for the next reverse wrapping process. Specifically, when the locking device 7 locks the main shaft 1, the reverse wrapping driving device 2 drives the first end 91 of the reverse wrapping rod 9 to move horizontally, so that the reverse wrapping rod 9 can be switched between the first state and the second state.

[0037] As Figure 6 and combined with Figures 1 to 5 shown, the locking device 7 includes a first elastic member 10, a pressing member 11, and a first cylinder body sequentially arranged from the inside to the outside around the main shaft 1. The first cylinder body includes a first inner cylinder body 12 and a first outer cylinder body 13. A first cavity extending along the axial direction of the main shaft 1 is formed between the first inner cylinder body 12 and the first outer cylinder body 13. The first cavity has a force transmission medium and the first cavity extends towards the pressing member. The locking device 7 further includes a first piston 15 received in the first cavity. The first piston 15 can axially move in the first cavity along the extending direction of the main shaft 1 to compress the force transmission medium to generate pressure, and the pressure acts on the pressing member to lock the main shaft.

[0038] As Figure 6As shown, the first piston 15 divides the first cavity into a first chamber 14, a third chamber 17, and a second chamber 16 that are successively farther away from the middle ring. Among them, the second chamber 16 is recessed from the inside of the first inner cylinder 12 to form, and a force - transmitting medium is filled therein. Further, the second chamber 16 includes a passage 161 extending toward the pressing member 11. In the present invention, the first chamber 14 and the third chamber 17 can be connected to a gas source or a fluid pressure source (such as a hydraulic pressure source). Taking the connection of the first chamber 14 and the third chamber 17 to the gas source as an example, the first piston 15 can be driven by gas to axially reciprocate along the extension direction of the main shaft 1. And an elastic member such as a spring can be arranged on the inner side wall of the first chamber 14 facing the third chamber 17. At least one spring can be provided, which is axially parallel to the main shaft 1 and distributed around the first piston 15 to release the extrusion of the force - transmitting medium in the second chamber 16 by the first piston 15, so that the pressing member 11 returns to its original state to release the main shaft 1. Taking the liquid plastic as an example for the force - transmitting medium in the second chamber 16, when the first piston 15 moves axially, it can extrude the liquid plastic in the second chamber 16, so that the liquid plastic can instantaneously generate a huge pressure, and its pressure can reach hundreds of megapascals.

[0039] As Figure 1 , Figure 2 and Figure 6 shown, the first piston 15 is separately provided, which includes a first part 151 located in the first chamber 14 and the third chamber 17 and a second part 152 located in the second chamber 16. Among them, the first part 151 is provided with a recess 19 for clamping one end of the second part 152. The recess 19 can limit one end of the second part 152. Therefore, when the third chamber 17 is inflated by the gas source and at the same time the first air chamber 14 exhausts air, when the first part 151 is driven by the gas to move in the C direction, the second part 152 can be pushed by the first part 151 through the recess 19 to axially move in the second chamber 16 and the third chamber 17. Thus, the second part 152 can compress the force - transmitting medium in the second chamber 16, and the first piston 15 can axially move along the extension direction of the main shaft 1. Conversely, when the first chamber 14 is inflated by the gas source and at the same time the gas source in the third chamber 17 exhausts air, the first part 151 is driven by the gas in the first chamber 14 to move in the opposite direction of C. Then the force - transmitting medium in the second chamber 16 is no longer compressed, and the force - transmitting medium will elastically reset. When the force - transmitting medium resets, a reset pressure will be generated, and this reset pressure can successively push the second part 152 and the first part 151 to axially move for reset. Of course, in other embodiments, the first part 151 and the second part 152 can also be reset not by inflating the first chamber 14, but only by the elastic reset force of the force - transmitting medium. As Figure 6 and combined with Figures 1 to 5As shown, the first elastic member 10 is a spring sleeve with a variable diameter. Its radially inner side is tightly sleeved on the main shaft 1, and its radially outer side is closely adjacent to the pressing member 11. Therefore, the compressive capacity of the end face of the pressing member 11 (the axial pressure of the main shaft 1 in this embodiment) can be increased, and the pressing member 11 can be prevented from being damaged by force. The pressing member 11 is a thin-walled ring located between the first elastic member 10 and the first inner cylinder 12, and its radially outer side is closely attached to the wall surface of the first inner cylinder 12. A radially recessed groove 20 is provided on the outer surface of the pressing member 11 to reduce the thickness of the pressing member 11, thereby increasing the deformation capacity of the pressing member 11. The groove 20 communicates with the passage 161 of the first inner cylinder 12. Since the passage 161 communicates with the second chamber 16, the groove 20, the passage 161, and the second chamber 16 communicate with each other. Also, since the second part 152 of the first piston 15 is received in the second chamber 16, a closed receiving cavity is formed by a part of the space of the second chamber 16, the passage 161, and the groove 20, and a certain volume of force-transmitting medium is filled in this receiving cavity. In addition, in order to ensure the sealing between the receiving cavity and the first chamber 14 and the third chamber 17 and prevent the force-transmitting medium in the receiving cavity from flowing into the first chamber 14 and the third chamber 17, at least one sealing ring is provided between the second part 152 and the first inner cylinder 12, between the first part 151 and the first inner and outer cylinders, and between the pressing member 11 and the first inner cylinder 12.

[0040] As Figure 6 and in combination with Figures 1 to 5As shown, when the second part 152 of the first piston 15 is pushed by the first part 151 to move in the C direction, the force - transmitting medium in the receiving cavity is compressed to generate a huge pressure. This pressure acts on the pressing member 11, and the pressing member 11 deforms under the force to squeeze the first elastic member 10. After being squeezed, the first elastic member 10 deforms, that is, its diameter becomes smaller. Thus, the first elastic member 10 can hold the main shaft 1 tightly, and then the locking device 7 will not move axially relative to the main shaft 1. In addition, since the pressure generated by the compression of the force - transmitting medium in the second chamber 16 is absorbed by the first elastic member 10 and the pressing member 11 to cause the first elastic member 10 and the pressing member 11 to deform, in order to make the largest proportion of the pressure generated by the compression of the force - transmitting medium be used to hold the main shaft 1 tightly and make the holding effect better, in other feasible cases, the first elastic member 10 can also be not provided, and only rely on the pressing member 11 to hold the main shaft 1 tightly. When the air source no longer supplies air to the first chamber 14, the pressure generated by the force - transmitting medium disappears. Then, the first elastic member 10 and the pressing member 11 return to their original states by their own elastic forces, thus releasing the main shaft 1. The force - transmitting medium in the second chamber 16 is affected by the elastic restoring forces of the first elastic member 10 and the pressing member 11, and can push the second part 152 to move axially in the opposite direction of C to push the first part 151 to also move axially in the opposite direction of C. At the same time, the first part 151 can also be pushed axially in the opposite direction of C by the air pressure in the third cavity 17. Thus, the first piston 15 can move axially in the opposite direction of C to reset.

[0041] The first part 151 and the second part 152 of the first piston 15 of the present invention can be integrally provided. As Figure 5 and combined with Figure 4 shown, the first part 151 and the second part 152 are integrated into one body, and this integrated body reciprocates in the first chamber 14, the third chamber 17 and the second chamber 16.

[0042] The present invention also provides an alternative embodiment. As Figure 8 and combined with Figures 1 to 5 shown, the aforementioned locking device 7 includes a first elastic member 10, a pressing member 11 and a first cylinder body arranged around the main shaft 1 from the inside to the outside in sequence. The first cylinder body includes a first inner cylinder body 12 and a first outer cylinder body 13. A first cavity extending radially along the main shaft 1 is formed between the first inner cylinder body 12 and the first outer cylinder body 13. A first piston 15' is received in the first cavity, and the first piston 15' can be driven by gas to move radially along the main shaft 1 in the first cavity. The first piston 15' divides the first cavity into a first chamber (not shown) far from the main shaft 1 and a second chamber 16' close to the main shaft 1, and the force - transmitting medium is located in the second chamber 16', and the second chamber 16' extends towards the pressing member 11.

[0043] As Figure 8As shown, the first elastic member 10 is a spring sleeve with a variable diameter. Its inner radial side is tightly sleeved on the main shaft 1, and its outer radial side is closely abutted against the pressing member 11. Therefore, the compressive capacity of the end face of the pressing member 11 (referring to the axial pressure of the main shaft 1 in this embodiment) can be increased, and the pressing member 11 can be prevented from being damaged by force. The pressing member 11 is a thin-walled ring located between the first elastic member 10 and the first inner cylinder 12, and its outer radial side closely adheres to the wall surface of the first inner cylinder 12. A groove 20 is concavely provided on the outer radial side of the pressing member 11 to reduce the thickness of the pressing member 11, thereby increasing the deformation capacity of the pressing member 11. The groove 20 is communicated with the second chamber 16'. The second chamber 16' and the groove 20 form a closed receiving chamber, and a certain volume of force-transmitting medium is filled in the receiving chamber. To ensure the sealing between the receiving chamber and the first chamber and prevent the force-transmitting medium in the receiving chamber from overflowing into the first chamber, at least one sealing ring is provided between the first piston 15' and the first inner cylinder 12 and the first outer cylinder 13, and between the pressing member 11 and the first inner cylinder 12.

[0044] As Figure 8 shown, when the first piston 15' moves towards the D direction, the force-transmitting medium in the second chamber 16' and the groove 20 is compressed to generate a huge pressure. This pressure acts on the pressing member 11 and the first elastic member 10 in sequence. After the pressing member 11 is stressed, it deforms to squeeze the first elastic member 10. After the first elastic member 10 is squeezed, it deforms, that is, its diameter becomes smaller. Thus, the first elastic member 10 can hold the main shaft 1 tightly, and further, the locking device 7 will not axially move relative to the main shaft 1. Preferably, in order to make the holding effect better, the first elastic member 10 can also not be provided, and only the pressing member 11 is relied on to hold the main shaft 1 tightly.

[0045] As Figures 1 to 5 shown, the reverse wrapping driving device 2 includes a second cylinder body. The second cylinder body is provided with a second inner cylinder 30 and a second outer cylinder 31 arranged from the inside to the outside around the outer shaft sleeve 3. A second chamber 32 is formed between the second inner cylinder 30 and the second outer cylinder 31. A second piston 33 is provided in the second chamber 32, and the second piston 33 is fixedly connected to the first outer cylinder 13. Further, the reverse wrapping driving device 2 further includes an annular connecting plate 34 fixedly connected to the second outer cylinder 31, and the connecting plate is pivotally connected to the reverse wrapping rod 9. When the reverse wrapping driving device 2 is driven by gas, the second outer cylinder 31 and the second inner cylinder 30 can axially move along the main shaft 1, so that the connecting plate 34 axially moves. Further, the first end 91 of the reverse wrapping rod 9 can axially move along the main shaft 1, and the second end 92 of the reverse wrapping rod 9 can cooperate with the tire component on the tire forming drum 100 to perform a reverse wrapping action.

[0046] After the reverse wrapping operation is completed, the air source no longer supplies air to the reverse wrapping driving device 2, and the reverse wrapping rod 9 is in a state parallel to the main shaft 1. At this time, the air source of the locking device 7 no longer supplies air or the air source of the locking device 7 supplies air reversely to the first piston 15 (opposite to the C direction), and the first elastic member 10 will restore its original diameter by relying on its own elastic force, thereby loosening the main shaft. Further, the fluid in the second chamber 16 generates a fluid pressure under the influence of the elastic reset of the first elastic member 10, and this fluid pressure acts on the first piston 15. Therefore, the first piston 15 axially moves in the opposite direction of C to reset. When the lead screw 4 rotates, it can drive the first outer cylinder 13, the second piston 33, and the outer shaft sleeve 3 to axially move, thereby driving the entire half-drum to axially move, and further adjusting the distance between the two half-drums to cooperate with the tire building drum 100 to complete the shaping process of the tire components.

[0047] The present invention also provides an alternative embodiment in which the reverse wrapping driving device 2 adopts the locking structure of the locking device 7, such as Figure 7 and Figure 8 the reverse wrapping driving device 2' therein, so that the reverse wrapping driving device 2' and the locking device 7 form an interlocking device with alternating locking to assist the tire building drum 100 in shaping the tire components. Further, one end of the outer shaft sleeve 3 of the tire building drum 100 of the present invention is fixedly connected to the first outer cylinder 13, and the other end is fixedly connected to the reverse wrapping rod guide disc 8. The locking device 7 or the reverse wrapping driving device 2' (which is actually the same as the structure of the locking device 7) is fixedly connected to the connecting member 6. The locking device 7 and the reverse wrapping driving device 2' are supplied with air by the same air source, that is, the release control of the locking device 7 and the locking control of the reverse wrapping driving device 2' are realized by the same air source or hydraulic source, and the locking control of the locking device 7 and the release control of the reverse wrapping driving device 2' are realized by the same air source or hydraulic source.

[0048] Specifically, the locking device 7 and the reverse wrapping driving device 2' can be supplied with air by the same air source, and the release control of the locking device 7 and the locking control of the reverse wrapping driving device 2' are realized by the same air source or hydraulic source, and the locking control of the locking device 7 and the release control of the reverse wrapping driving device 2' are realized by the same air source or hydraulic source. Since the locking device 7 and the reverse wrapping driving device 2' have the same structure, the reverse wrapping driving device 2' has a fourth chamber 14', a fifth chamber 16-1, and a sixth chamber 17' corresponding to the first chamber 14, the second chamber 16, and the third chamber 17 of the locking device 7 respectively, and also has a third piston 15-1 corresponding to the first piston 15 of the locking device 7.

[0049] Such as Figure 6As shown, the sixth chamber 17' and the first chamber 14 are supplied with air from the same air source, and the third chamber 17 and the fourth chamber 14' are supplied with air from the same air source. When the sixth chamber 17' and the first chamber 14 are supplied with air, and the third chamber 17 and the fourth chamber 14' are exhausted, the third piston 15-1 moves in the direction C, squeezing the fifth chamber 16-1, causing the turn-up drive device 2' to grip the outer sleeve 3. The first piston 15 moves in the direction opposite to C, causing the force transmission medium in the second chamber 16 to elastically recover, thereby releasing the locking device 7 from the spindle 1. Conversely, when the sixth chamber 17' and the first chamber 14 are exhausted, and the third chamber 17 and the fourth chamber 14' are supplied with air, the third piston 15-1 moves in the direction opposite to C, causing the force transmission medium in the fifth chamber 16-1 to elastically recover, thereby releasing the outer sleeve 3. The first piston 15 moves in the direction C, squeezing the force transmission medium in the second chamber 16, thereby releasing the locking device 7 from the spindle 1.

[0050] Therefore, when the locking device 7 locks the main shaft 1, the turn-up drive device 2' can synchronously release the outer shaft sleeve 3. At this time, the screw rod 4 rotates, and the turn-up drive device 2' can move axially on the outer shaft sleeve 3, so that the first end 91 of the turn-up rod 9 pivoted to the turn-up drive device 2' can move axially along the main shaft 1, and the second end 92 of the turn-up rod 9 can cooperate with the tire component on the tire building drum 100 to perform a turn-up action; when the locking device 7 releases the main shaft 1, the turn-up drive device 2' synchronously locks the outer shaft sleeve 3, and no relative movement occurs between the locking device 7, the turn-up drive device 2' and the outer shaft sleeve 3. Therefore, when the screw rod 4 rotates, the turn-up drive device 2' and the outer shaft sleeve 3 can be driven to move axially, thereby driving the locking device 7 to move axially, that is, the entire half drum moves axially, and then the distance between the two half drums can be adjusted, and the tire building drum 100 is cooperated to complete the shaping process of the tire component.

[0051] The locking device 7 of the present invention is provided with a first cylinder, a first piston, a first chamber and a second chamber, so that when the first piston is driven by air pressure to move in the first cylinder, the first piston can compress the force transmission medium in the second chamber. After the force transmission medium is compressed, a huge pressure is instantly generated, and the pressure can reach hundreds of MPa. This pressure acts directly on the pressure piece, so that the pressure piece holds the main shaft tightly. Therefore, under the same pneumatic driving force conditions, the pressure generated by the linkage structure of the present invention is greater than that of the simple air pressure, thereby achieving a better holding effect.

[0052] In the description of the specific embodiments, discussion terms such as "in this embodiment," "in one embodiment," or "in a specific embodiment" indicate that the specific features or characteristics described in conjunction with that embodiment are included in at least one embodiment of the present invention. Furthermore, the schematic representations of these terms in the specific embodiments do not necessarily refer to the same embodiment. Furthermore, the specific features or points described may be combined in any suitable manner in any one or more embodiments.

[0053] Obviously, the above-mentioned embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limitations on the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A locking device is provided on the main shaft of a tire building drum, characterized in that, The locking device includes a pressure member and a first cylinder arranged in sequence from the inside to the outside around the main shaft, the first cylinder having a first cavity containing a force transmission medium and extending toward the pressure member, and the locking device also includes a first piston accommodated in the first cavity, the first piston being movable in the first cavity to compress the force transmission medium to generate pressure, the pressure acting on the pressure member to lock the main shaft; The first piston divides the first cavity into a first chamber and a second chamber, the second chamber extends toward the pressure member and the force transmission medium is located in the second chamber, and the first piston can move radially in the first chamber to compress the force transmission medium in the second chamber; The locking device further comprises a first elastic member sleeved on the main shaft and arranged close to the pressing member. The pressure causes the pressing member to press against the first elastic member, and the first elastic member is deformed and then holds the main shaft tightly.

2. The locking device according to claim 1, wherein The force transmission medium is liquid plastic.

3. The locking device according to claim 1, characterized in that, The first piston includes a first part and a second part, the first part and the second part divide the first cavity into a first chamber, a second chamber and a third chamber, the second chamber extends toward the pressure member, the second part and the force transmission medium are both located in the second chamber, and the first part is located in the first chamber and the third chamber.

4. The locking device according to claim 3, characterized in that, The first part is provided with a recessed portion that is engaged with one end of the second part. The recessed portion can limit one end of the second part. The first part pushes the second part to move axially along the main shaft through the recessed portion to compress the force transmission medium in the second chamber.

5. The locking device according to any one of claims 1, 3 or 4, characterized in that, The pressing piece is provided with a radially recessed groove.

6. The locking device according to claim 5, characterized in that, The second chamber is located in the first cylinder and communicates with the groove.

7. A tire building drum, comprising: A main shaft, a screw located in the main shaft, two half-drums arranged around the main shaft and a connecting assembly that connects the two half-drums to the screw respectively, characterized in that each half-drum includes an outer sleeve sleeved on the main shaft, a turn-up drive device, a locking device as described in any one of claims 1-6 and a turn-up unit with one end pivotally connected to the turn-up drive device and having several turn-up rods distributed along the circumferential direction, when the locking device locks the main shaft, the turn-up drive device drives the turn-up rod to turn over; when the locking device releases the main shaft, the screw rotates and drives the connecting assembly and the two half-drums to move axially relative to each other in turn.

8. The tire building drum according to claim 7, wherein, The locking device has the same structure as the turn-up driving device.

9. The tire building drum according to claim 8, characterized in that, The locking control of the turn-up drive device and the releasing control of the locking device are realized by the same air source or hydraulic source, and the releasing control of the turn-up drive device and the locking device are realized by the same air source or hydraulic source. When the locking device locks the main shaft, the turn-up drive device releases the outer sleeve to allow the turn-up drive device to move axially along the outer sleeve; when the locking device releases the main shaft, the turn-up drive device locks the outer sleeve to allow the two half-drums to move axially relative to or opposite to each other.

10. The tire building drum according to claim 7, characterized in that, The connecting component includes two drive nuts respectively located on two sides of the lead screw and threadedly connected to the lead screw, and a connecting member fixedly connecting the drive nuts and the semi-drum.

11. The tire building drum according to claim 10, characterized in that, The reverse wrapping drive device includes a second cylinder body, a second cavity formed in the second cylinder body, and a second piston received in the second cavity, and the second piston is fixedly connected to the first cylinder body.

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