1. A secondary expansion RFT tyre building drum comprising a main shaft (1) and a sleeve (2) fitted over the main shaft (1), characterized in that it further comprises:

the sliding cylinder body (3), the sliding cylinder body (3) is connected to the shaft sleeve (2) in a sliding mode;

the piston disc (4) is arranged in the sliding cylinder body (3) and fixedly connected to the shaft sleeve (2), and the sliding cylinder body (3) is divided into an air chamber I (P11) and an air chamber II (P21) by the piston disc (4);

the telescopic guide discs (8) are fixedly connected to the shaft sleeve (2) and symmetrically arranged on two sides of the sliding cylinder body (3);

the guide strip (7), the said guide strip (7) is set up in the inboard of the flexible guiding disc (8);

the two sides of the sector (6) are provided with slideways matched with the guide bars (7), and the sector (6) is connected to the guide bars (7) in a sliding manner through the slideways;

the two ends of the sliding connecting rod (5) are respectively hinged on the sliding cylinder body (3) and the sector (6);

the combined drum plate (9), the combined drum plate (9) is fixedly connected to the circumferential outer side of the sector (6);

the secondary expansion driving device is used for driving the sliding cylinder (3) to horizontally slide on the main shaft (1);

the air path I (P1) is arranged in the main shaft (1) and is communicated with the air chamber I (P11);

and the gas path II (P2) is arranged in the main shaft (1) and is communicated with the gas chamber II (P21).

2. A secondary expansion RFT tire building drum as claimed in claim 1 wherein said secondary expansion drive comprises: a push disc (10), a spring (11), a movable guide rod (12), a connecting flange disc (13) and a connecting counter-center shaft (16); the connecting counter middle shaft (16) is connected to the main shaft (1) in a sliding mode, the connecting flange (13) is fixedly connected to the connecting counter middle shaft (16), the connecting flange (13) is in sliding fit with the telescopic guide disc (8) through the movable guide rod (12), and the movable guide rod (12) is provided with a spring (11) located between the inner side of the connecting flange (13) and the outer side of the telescopic guide disc (8).

3. A secondary expandable RFT tyre building drum according to claim 1, characterised in that the outside of the building drum plate (9) is provided with a rubber annulus (17) with an anti-sticking step.

4. A secondary expansion RFT tyre building drum according to claim 1, characterized in that the main shaft (1) is provided with a sliding groove cooperating with the coupling counter shaft (16), the coupling counter shaft (16) cooperating with the main shaft (1) for sliding movement through the sliding groove.

5. A secondary expansion RFT tyre building drum according to claim 1, characterized in that the sleeve (2) is fixed to the main shaft (1) by means of a fastening nut (14).

6. A method of building a secondary expanded RFT tire blank, comprising the steps of using a secondary expanded RFT tire building drum according to any of claims 1-5, and:

s1, performing first expansion on the secondary expanded RFT tire forming drum;

s2, attaching the lining;

s3, performing secondary expansion on the secondary expanded RFT tire forming drum;

s4, sequentially attaching the supporting glue and the tire body;

s5, buckling a ring and turning up the bag;

s6, rolling and turning;

s7, attaching the sidewalls;

s8, rolling the side wall;

and S9, shrinking the drum and removing the tire.

7. The method of claim 1 wherein the ratio of the outermost radius r1 of the first expanded composite drum to the outermost radius r2 of the second expanded composite drum is r1 ═ r2 × (90% -100%).

Background

In the process of manufacturing secondary molding of RFT (Run Flat tire), semi-finished products such as an inner liner, a tire body, supporting glue, a tire side, a tire bead and the like need to be fixed on a section of molding drum and combined into a certain shape, so that the requirement of material distribution of construction design is met.

At present, in the material of RFT tire, more ordinary tire has increased the reinforcing layer material, and the reinforcing layer material has the great thickness of material such as relative matrix, inside lining, and the combination drum plate of one section traditional shaping drum is planar structure, when laminating on one section shaping drum of traditional plane combination drum plate, can produce great difference in height, when laminating matrix material again, can cause technological problems such as taking off the sky, breaking over and tensile, can't the shaping.

In order to solve the above technical problems, the prior art adopts a combined drum plate with a certain shape as shown in fig. 3 to improve the problem that the tire body cannot be attached; the longitudinal section of the structure of the combined drum plate in fig. 3 is trapezoidal, specifically: the middle part is a plane, and the two sides are inclined planes, so that the problem of height difference caused by the plane combined drum plate is solved.

However, the drum surface of the combined drum plate is uneven, so that the attached lining has a suspension problem at the left and right sections when the lining is attached; therefore, when the support rubber is attached, the lining is easily broken, air bubbles are generated between the lining and the support rubber, the forming quality of a tire blank is affected, and the problems of air bubbles, delamination and uniformity performance reduction of a finished tire are caused.

How to solve the technical problems is a technical problem to be solved in the technical field of tire manufacturing at present.

Disclosure of Invention

In view of the above technical problems, embodiments of the present invention provide a secondary expansion RFT tire building drum and a method for building an RFT tire blank, so as to solve the problems in the background art.

The invention provides the following technical scheme: a secondary expanded RFT tire building drum comprising a spindle and a sleeve journalled thereon, further comprising:

the sliding cylinder body is connected to the shaft sleeve in a sliding mode;

the piston disc is arranged in the sliding cylinder body and fixedly connected to the shaft sleeve, and the sliding cylinder body is divided into an air chamber I and an air chamber II by the piston disc;

the telescopic guide discs are fixedly connected on the shaft sleeve and symmetrically arranged on two sides of the sliding cylinder body;

the guide strip is arranged on the inner side of the telescopic guide disc;

the two sides of the sector are provided with slide ways matched with the guide strips, and the sector is connected to the guide strips in a sliding manner through the slide ways;

the two ends of the sliding connecting rod are respectively hinged on the sliding cylinder body and the sector;

the combined drum plate is fixedly connected to the circumferential outer side of the sector;

the secondary expansion driving device is used for driving the sliding cylinder body to horizontally slide on the main shaft;

the air path I is arranged in the main shaft and is communicated with the air chamber I;

and the air path II is arranged in the main shaft and is communicated with the air chamber II.

Preferably, the secondary expansion driving means includes: the push disc, the spring, the movable guide rod, the connecting flange plate and the connecting counter center shaft are arranged on the center shaft; the connecting centering shaft is connected with the main shaft in a sliding manner, the connecting flange plate is fixedly connected to the connecting centering shaft, the connecting flange plate is in sliding fit with the telescopic guide plate through the movable guide rod, and the movable guide rod is provided with a spring positioned between the inner side of the connecting flange plate and the outer side of the telescopic guide plate.

Preferably, the outer side of the combined drum plate is provided with a rubber annular belt with an anti-sticking step.

Preferably, the main shaft is provided with a sliding groove matched with the connecting centering shaft, and the connecting centering shaft is matched with the main shaft to slide through the sliding groove.

Preferably, the sleeve is fixed to the main shaft by a fastening nut.

A method of building a secondary expanded RFT tire blank using the secondary expanded RFT tire building drum of claim, comprising the steps of:

s1, performing first expansion on the secondary expanded RFT tire forming drum;

s2, attaching the lining;

s3, performing secondary expansion on the secondary expanded RFT tire forming drum;

s4, sequentially attaching the supporting glue and the tire body;

s5, buckling a ring and turning up the bag;

s6, rolling and turning;

s7, attaching the sidewalls;

s8, rolling the side wall;

and S9, shrinking the drum and removing the tire.

Preferably, the ratio of the outermost radius r1 of the first expanded composite drum plate to the outermost radius r2 of the second expanded composite drum plate is in the range of r1 ═ r2 × (90% to 100%).

The secondary expansion RFT tire forming drum and the RFT tire blank forming method provided by the embodiment of the invention have the following beneficial effects:

1. according to the RFT tire forming drum with secondary expansion, in the process of forming a tire blank of the RFT tire, after the inner liner is attached, the forming drum is expanded for the second time, so that the hooping of the inner liner is arranged on the forming drum, and when the supporting adhesive and the tire body are attached, the problems of folding, air bubbles and deflection in positioning of the inner liner are avoided, the quality of the tire blank is improved, the quality hidden danger of a finished tire is reduced, and the quality of the finished tire is improved;

2. the quality problem that the forming process does not meet the process requirements is solved, the manual auxiliary operation time is reduced, the production continuity is enhanced, and the production efficiency is improved.

Drawings

FIG. 1 is a schematic cross-sectional view of a two-stage expanded RFT tire building drum of the present invention;

FIG. 2 is a schematic view of a conventional prior art RFT tire construction;

FIG. 3 is a schematic view of a prior art composite drum plate with a modified building drum;

FIG. 4 is a schematic view of a secondary expanded RFT tire building drum diameter variation configuration of the present invention;

wherein A is a shrinkage state diagram, B is a first expansion state diagram, and C is a second expansion state diagram;

1. the improved combined drum plate structure comprises a main shaft, 2. a shaft sleeve, 3. a sliding cylinder body, 4. a piston plate, 5. a sliding connecting rod, 6. a sector, 7. a guide strip, 8. a telescopic guide plate, 9. a combined drum plate, 10. a push plate, 11. a spring, 12. a movable guide rod, 13. a connecting flange plate, 14. a fastening nut, 16. a connecting counter center shaft, 17. a rubber annular belt with anti-sticking step, P1. a gas circuit I, P2. a gas circuit II, P11. a gas chamber I, P21. a gas chamber II, 21. an inner liner, 22. a reinforcing layer and 24. the improved combined drum plate structure.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments obtained by a person skilled in the art based on the embodiments of the present invention without any creative work belong to the protection scope of the present invention.

Example 1, see fig. 1-4.

In view of the above mentioned problems in the background art, the embodiment of the present invention provides a secondary expansion RFT tire building drum to solve the above mentioned technical problems, and the technical solution is as follows:

a secondary expansion RFT tire building drum comprises a main shaft 1 and a shaft sleeve 2 sleeved on the main shaft 1, wherein the shaft sleeve 2 is fixed on the main shaft 1 through a fastening nut 14; the invention also includes:

the sliding cylinder body 3 is connected to the shaft sleeve 2 in a sliding mode; the sliding cylinder 3 and the shaft sleeve 2 are sealed at the sliding connection part, such as a sealing ring and the like;

the piston disc 4 is arranged in the sliding cylinder 3 and fixedly connected to the shaft sleeve 2, and the sliding cylinder 3 is divided into an air chamber I P11 and an air chamber II P21 by the piston disc 4; the contact surface of the upper end surface of the piston disc 4 and the inner wall of the sliding cylinder body 3 is also sealed;

the telescopic guide discs 8 are fixedly connected to the shaft sleeve 2 and symmetrically arranged at two sides of the sliding cylinder body 3;

the guide strip 7 is fixed on the inner side of the telescopic guide disc 8;

the fan-shaped body 6 is characterized in that sliding ways matched with the guide strips 7 are arranged on two sides of the fan-shaped body 6, and the fan-shaped body 6 is connected to the guide strips 7 in a sliding mode through the sliding ways;

the two ends of the sliding connecting rod 5 are respectively hinged on the sliding cylinder body 3 and the sector 6;

when the sliding cylinder body 3 moves left and right on the main shaft 1, the sliding connecting rod 5 is driven to perform left and right inclined movement, so that the sector 6 is driven to move up and down along the guide strip 7;

the combined drum plate 9 is fixedly connected to the circumferential outer side of the sector 6;

a secondary expansion driving device for driving the sliding cylinder 3 to horizontally slide on the main shaft 1;

the air path IP 1 is arranged in the main shaft 1 and communicated with the air chamber IP 11;

and the gas path IIP 2 is arranged in the main shaft 1 and is communicated with the gas chamber IIP 21.

The secondary expansion driving device includes: the device comprises a push disc 10, a spring 11, a movable guide rod 12, a connecting flange disc 13 and a connecting counter-center shaft 16;

the connecting counter middle shaft 16 is connected to the main shaft 1 in a sliding mode, the connecting flange 13 is fixedly connected to the connecting counter middle shaft 16, the connecting flange 13 is fixedly provided with a movable guide rod 12, the telescopic guide disc 8 is provided with a through hole matched with the movable guide rod 12, the connecting flange 13 is in sliding fit with the telescopic guide disc 8 through the movable guide rod 12, and the movable guide rod 12 is provided with a spring 11 located between the inner side of the connecting flange 13 and the outer side of the telescopic guide disc 8.

A rubber ring belt 17 with an anti-sticking step is arranged on the outer side of the combined drum plate 9; the rubber ring belt 17 with the anti-sticking step is used for avoiding or reducing the adhesion between the lining and the combined drum plate, and the problem of uneven stretching of the lining is caused in the expansion process.

It should be noted that the number and the structural size of the drum plates in the combined drum plate 9 need to be specifically determined according to the actual tire specification and size, and meanwhile, other structures that are connected with the combined drum plate 9 in a matching manner are also correspondingly arranged.

The main shaft 1 is provided with a sliding groove matched with the connecting counter-center shaft 16, and the connecting counter-center shaft 16 is matched with the main shaft 1 to slide through the sliding groove.

The invention relates to a working method of a secondary-expansion RFT tire forming drum, which comprises the following steps:

1. and (3) a drum shrinking process: the compressed air pressurizes the air chamber IIP 21 through an air path IIP 2, the sliding cylinder 3 moves leftwards, the sector 6 is driven to move downwards through the sliding connecting rod 5, and the combined drum plate 9 contracts downwards along with the sector 6, so that the diameter of the forming drum is reduced; at the moment, under the action of the spring 11, the push disc 10 is tightly attached to the telescopic guide disc 8;

2. the first expansion process: applying external force to provide thrust to the connecting flange 13 (in the embodiment, the forming machine is provided with a driving device), overcoming the resistance of the spring 11, enabling the push disc 10 to push the sliding cylinder 3 to move rightwards, enabling the sliding cylinder 3 to drive the sector 6 to move upwards through the sliding connecting rod 5, enabling the combined drum plate 9 to expand upwards along with the sector 6, and enabling the diameter of the forming drum to be increased; at the moment, the compressed air pressurizes the air chamber IIP 21 through the air passage IIP 2, so that the sliding cylinder 3 is tightly attached to the push disc 10, the pressure of the air passage IIP 2 is smaller than the thrust of the flange 13, and the diameter of the forming drum is kept stable;

3. and (3) second expansion: the compressed air pressurizes the air chamber IP 11 through an air path IP 1, the sliding cylinder 3 continues to move rightwards, the sector 6 is driven to move upwards through the sliding connecting rod 5, and the combined drum plate 9 expands upwards along with the sector 6, so that the diameter of the forming drum is increased again; at this time, the slide link 5 is perpendicular to the slide cylinder 3, and acts to receive a large load applied to the drum assembly 9, thereby making it possible to keep the drum diameter stable.

Example 2, see fig. 1-4.

On the basis of the secondary expansion RFT tire forming drum, the invention also designs a secondary expansion RFT tire blank forming method, which adopts the secondary expansion RFT tire forming drum designed by the invention and comprises the following steps:

s1, performing first expansion on the secondary expanded RFT tire forming drum;

s2, attaching the lining;

s3, performing secondary expansion on the secondary expanded RFT tire forming drum;

s4, sequentially attaching the supporting glue and the tire body;

s5, buckling a ring and turning up the bag;

s6, rolling and turning;

s7, attaching the sidewalls;

s8, rolling the side wall;

and S9, shrinking the drum and removing the tire.

Preferably, the ratio of the outermost radius r1 of the first-expansion combined drum plate to the outermost radius r2 of the second-expansion combined drum plate is in the range of r1 ═ r2 × 90% to 100%.

Example 3, to better explain the way in which the invention is applied to the green tyre building process of an RFT tyre, the 18 inch specification is taken as an example:

the thickness of the rubber ring belt with the anti-sticking cloth is 4mm, the thickness of the drum plate 2 is 10mm, and the radius of r2 is 245mm

S1, expanding the forming drum for the first time;

selecting r1 ═ r2 ═ 95%, (245-10-4) ≈ 95 ≈ 219.5 mm;

s2, attaching the lining;

s3, expanding the forming drum for the second time;

the second expansion of the forming drum meets the requirement that r1 is 245mm, and the lining is completely hooped on the drum;

s4, sequentially attaching the support rubber and the tire body;

s5, buckling a ring and turning up the bag;

s6, rolling and turning;

s7, attaching the sidewalls;

s8, rolling the side wall;

and S9, shrinking the drum and removing the tire to complete the molding of the tire blank.

After the tire blank is finished, the problems of no lining folding and no bubbles are confirmed in the appearance of the tire blank, the appearance defects of delamination and the like are avoided after the vulcanized finished tire is subjected to X-ray and bubble detection, the positioning of the material is confirmed on the cut surface accurately, and the design expectation is achieved.

The concept principle of the invention is as follows: the viscoelastic property of rubber is utilized, after the forming drum expands for the first time, the inner liner is attached to the forming drum, at the moment, the diameter of the middle part of the drum plate is larger than the diameters of the left side and the right side of the drum plate, the inner liners on the left side and the right side are in a suspended state, and particularly the inner liners are attached to the inflection points on the left side and the right side of the drum plate; secondly, expanding the forming drum for the second time, and utilizing the viscoelastic property of rubber to continuously increase the diameter of the forming drum so that the liner is completely coated on the drum plate and the left side and the right side of the liner are prevented from being suspended; and then sequentially attaching the support rubber and the tire body, and then buckling a ring, turning up, attaching the tire side, pressing the tire side and removing the tire to complete the molding of the tire blank.

Wherein, when preventing the forming drum secondary expansion, inside lining part and drum plate adhesion caused inhomogeneous tensile problem, increased the rubber clitellum of one deck area anti-sticking cloth between drum plate and inside lining part, guaranteed that the inside lining can evenly extend.

The above-described embodiments of the apparatus are merely illustrative, and the units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment.

In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "disposed," "connected," "secured," "screwed" and the like are to be construed broadly, e.g., as meaning fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; the terms may be directly connected or indirectly connected through an intermediate, and may be communication between two elements or interaction relationship between two elements, unless otherwise specifically limited, and the specific meaning of the terms in the present invention will be understood by those skilled in the art according to specific situations.

It should be understood that the technical solutions and concepts of the present invention may be equally replaced or changed by those skilled in the art, and all such changes or substitutions should fall within the protection scope of the appended claims.