Processes that ensure tire bead strength

Abstract

This invention discloses a process for ensuring tire bead strength, belonging to the field of engineering machinery tire manufacturing technology. The invention improves the process by refining the feeding and guiding method of the bead wire wrapping, the bonding method of the insulating film for the bead wire wrapping, and the bonding and positioning method of the bead wire wrapping. This addresses the problems of bead wire wrapping stretching caused by the feeding and guiding method in existing processes, the thickening of the bead wire wrapping ends due to the insulating film leading to incomplete compression and air bubbles, and the fluctuation in the width and position of the bead wire wrapping caused by relying solely on the outer end bonding and positioning method. Using the process of this invention to produce tires improves the conformity of the finished tire bead quality, solves the problem of early bead detachment and sidewall detachment during tire use, and increases the overall tire mileage.

Description

Technical Field

[0001] This invention relates to the field of engineering machinery tire manufacturing technology, specifically to a process for ensuring tire bead strength. Background Technology

[0002] Currently, the following problems exist in the process of bonding steel wire to the bead of engineering machinery tires: (1) such as Figure 1 As shown, during feeding and guiding, a fixed pulley is installed between the feeding end transmission roller and the bonding end transmission roller. A steel wire is hung on the fixed pulley, with one end connected to a counterweight and the other end connected to a guide roller, the guide roller being heavier than the counterweight. A contact switch is installed on one side of the guide roller. During bonding, the drive wheel in the feeding end transmission roller rotates to feed the material. As the bead wire wrapping fabric gradually accumulates between the feeding end transmission roller and the bonding end transmission roller, the bead wire wrapping fabric will fall downwards in an arc shape under the gravity of the guide roller until arc 1 is formed, triggering the contact switch. The drive wheel of the feeding end transmission roller stops rotating, stopping feeding. As the bead wire wrapping fabric at the bonding end is gradually bonded to the flat drum, the accumulated bead wire wrapping fabric between the feeding end transmission roller and the bonding end transmission roller gradually lifts the guide roller upwards until arc 2 is formed, leaving the contact switch. At this time, the drive wheel of the feeding end transmission roller continues to rotate to start feeding again, and then this action is repeated. In this feeding and guiding method, the weight and resistance of the guide roller itself will cause a 5-6mm stretch to the bead wire wrapping fabric. (2) For example Figure 2 As shown, in the process of bonding the isolation film, the existing bonding method is to bond the isolation film to the inner and outer ends of the bead wire wrapping on the upper surface of the bead wire wrapping, and the outer end of the isolation film is aligned with the inner and outer ends. This will make the end part of the bead wire wrapping thicker and uneven in transition. During the production process, there is a risk of incomplete pressing and air bubbles in this part, which will affect the strength of the tire bead. (3) When bonding the bead wire wrapping, the outer end positioning method is adopted, that is, the positioning laser mark is used to position the standard position of the outer end of the bead wire wrapping. After bonding, the outer end of the bead wire wrapping is aligned with the standard position. However, this positioning method cannot check the position of the inner end of the bead wire wrapping. Therefore, it is impossible to determine whether the width of the bead wire wrapping and the position of the inner end meet the standard. As a result, the inner end of the stretched bead wire wrapping is not identified, which ultimately leads to the reduction of the height of the inner end of the finished tire bead wire wrapping, which increases the height difference between the inner and outer ends (e.g. Figure 5 (As shown). Since the bead wire wrapping is a crucial factor in ensuring bead strength, when the inner end of the bead wire wrapping is lower than the design requirements, it will lead to a reduction in the tire bead strength.

[0003] Furthermore, current product inspection standards cannot identify abnormalities in the bead wire wrapping, which may result in products that do not meet design requirements entering the market and causing early bead detachment and sidewall detachment during use, affecting the overall tire mileage. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a process to ensure the strength of the tire bead. The process of the present invention can improve the conformity of the quality of the finished tire bead, solve the quality problems of early bead detachment and sidewall detachment during tire use, and improve the overall service mileage of the tire.

[0005] The technical solution of this invention is as follows:

[0006] The process to ensure the strength of the tire bead is as follows: (1) When the bead wire wrapping is fed and guided, a background suppression photoelectric sensor and two correction guide rollers are installed between the feed end transmission roller and the bonding end transmission roller. The correction guide rollers are located on both sides of the bead wire wrapping. The background suppression photoelectric sensor is electrically connected to the controller. (2) When bonding the isolation film, the upper and lower surfaces of the bead wire wrapping are bonded with isolation films at the inner and outer ends of the bead wire wrapping. The center of the isolation film at the lower surface of the inner end is bonded to the inner end, and the center of the isolation film at the upper surface of the outer end is bonded to the outer end. The outer end of the isolation film at the upper surface of the inner end is bonded to the bead wire wrapping. The inner end of the cloth is misaligned, and the outer end of the isolation film on the lower surface of the outer end is misaligned with the outer end of the bead wire cloth; (3) When attaching the bead wire cloth, first use the positioning laser mark to locate the standard position of the inner end of the bead wire cloth, attach the inner end of the bead wire cloth to the standard position, and then attach the bead wire cloth circumferentially. After attaching, perform the joint and compaction operation of the bead wire cloth, and then use the positioning laser mark to locate the standard position of the outer end of the bead wire cloth. Confirm whether the deviation between the outer end of the attached bead wire cloth and the standard position meets the preset standard one. If it meets the standard, attach the isolation film on the upper surface of the outer end of the bead wire cloth.

[0007] Preferably, the method also includes a differential inspection step for the bead wire wrapping, which involves X-ray inspection of the finished tire, calculating the height difference between the outer and inner ends of the bead wire wrapping based on the X-ray image, and determining that the differential inspection of the bead wire wrapping of the finished tire is qualified if the height difference meets the preset standard two; otherwise, it is deemed unqualified.

[0008] Preferably, the outer end of the isolation film on the upper surface of the inner end point is misaligned with the inner end point of the bead wire wrapping cloth by 2-5mm, and the outer end point of the isolation film on the lower surface of the outer end point is misaligned with the outer end point of the bead wire wrapping cloth by 2-5mm.

[0009] Preferably, the preset standard is that the deviation between the outer end of the bead wire wrapping cloth after bonding and the standard position is ≤2mm.

[0010] Compared with the prior art, the present invention has the following advantages:

[0011] 1. The process of this invention avoids the stretching problem of the bead wire wrap caused by the gravity and resistance of the guide rollers during the feeding and guiding of the bead wire wrap, thus ensuring the strength of the bead. When the bead wire wrap is bonded to the release film, the inner and outer ends of the release film and the bead wire wrap are staggered, achieving a relatively smooth edge transition, which is beneficial for component compaction during production and reduces the risk of delamination quality due to non-compactness. In the bonding and positioning method of the bead wire wrap, the inner end of the bead wire wrap is used as the positioning point, and after bonding, the position of the outer end of the bead wire wrap is confirmed by the positioning laser light mark and tape measure, avoiding the inability to effectively identify whether the bonding position of the inner and outer ends does not meet the design requirements, and ensuring the conformity of the inner and outer end positions and the width of the bead wire wrap. Using the process of this invention to produce tires can improve the conformity of the quality of the finished tire bead, solve the quality problems of early bead detachment and sidewall detachment during tire use, and improve the overall service life of the tire.

[0012] 2. This invention performs X-ray inspection on the finished tires produced, and calculates the height difference between the inner and outer ends of the bead wire wrapping of the finished tire through the X-ray image, thereby determining whether the height difference meets the standard. It can identify and control abnormal problems of the bead wire wrapping in advance before the product enters the market, improve the inspection capability of the product leaving the factory, and reduce the product failure rate caused by it. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the feeding and guiding device for tire bead wire wrapping in the prior art.

[0015] Figure 2 This is a schematic diagram of the feeding and guiding device for the tire bead wire wrapping of the present invention.

[0016] Figure 3 This is a schematic diagram showing the bonding position of the insulating film on the steel wire wrapping of a tire bead in the prior art.

[0017] Figure 4This is a schematic diagram showing the bonding position of the insulating film of the tire bead wire wrapping cloth of the present invention.

[0018] Figure 5 This is a schematic diagram showing the height difference between the inner and outer ends of the tire bead wire wrapping after it has been stretched and bonded together.

[0019] Figure 6 This is the result of the tire bead durability test for Comparative Example 1.

[0020] Figure 7 These are the tire bead durability test results from Example 1.

[0021] In the diagram, 1. Bead wire wrapped with fabric; 2. Fixed pulley; 3. Steel wire; 4. Guide roller; 5. Contact switch; 6. Background suppression photoelectric sensor; 7. Correction guide roller; 8. Feeding end transfer roller; 9. Bonding end transfer roller; 10. Isolation film. Detailed Implementation

[0022] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0023] Comparative Example 1

[0024] The feeding and guiding method of the bead wire wrapping fabric, the bonding method of the isolation film of the bead wire wrapping fabric, and the bonding and positioning method of the bead wire wrapping fabric for 11.00R20 specification tire products are as described in the background art.

[0025] The changes in the width of the tire bead wire wrapping were tracked and measured during the molding process. The width of the bead wire wrapping at the same location before and after bonding reached 6 mm. However, since the existing technology uses the outer end point positioning method when bonding the bead wire wrapping, it is impossible to identify the width of the stretched bead wire wrapping.

[0026] A tire produced using the process described in Comparative Example 1 was randomly selected and subjected to a laboratory bead durability test. The test results are as follows: Figure 6 As shown, the actual durability time was 55 hours and 13 minutes (Note: Design standard ≥ 80 hours). The finished tire was verified by cross-section cutting. After cutting, the height difference between the outer and inner ends of the bead wire wrapping was measured, as shown in Table 1. This did not meet the height difference standard for this model of finished tire, leading to early tire failure.

[0027] Table 1

[0028]

[0029] Example 1

[0030] The feeding and guiding methods of the bead wire wrapping fabric, the bonding method of the bead wire wrapping fabric's isolation film, and the bonding and positioning method of the bead wire wrapping fabric for 11.00R20 specification tires have been adjusted. The adjusted process is as follows:

[0031] (1) such as Figure 2 As shown, during the feeding and unloading of the bead wire wrapping fabric, a background suppression photoelectric sensor and two correction guide rollers are installed between the feeding end transmission roller and the bonding end transmission roller. The correction guide rollers are located on both sides of the bead wire wrapping fabric to prevent the bead wire wrapping fabric from becoming skewed during transmission, which would cause the background suppression photoelectric sensor to fail to detect the bead wire wrapping fabric. The background suppression photoelectric sensor is electrically connected to the controller.

[0032] When the method of this embodiment is used to feed and guide the bead wire wrapping, the drive wheel in the feeding end transmission roller rotates to feed the material. As the bead wire wrapping gradually accumulates between the feeding end transmission roller and the bonding end transmission roller, the storage curvature of the bead wire wrapping gradually changes. When curvature 1 is formed, the background suppression photoelectric sensor is blocked, the feeding end transmission roller stops feeding, and the flat drum at the bonding end continues to bond with the bead wire wrapping until the storage curvature changes from curvature 1 to curvature 2. At this time, the background suppression photoelectric sensor will no longer be blocked, and the feeding end transmission roller continues to rotate to feed the material. Then this action is repeated.

[0033] Using this process, the width change of the bead wire wrapping at the same location as in Comparative Example 1 before and after bonding was measured. The width change decreased from 6 mm in Comparative Example 1 to 2 mm, indicating that the process design of this invention improves the problem of bead wire wrapping stretching caused by the gravity and resistance of the guide roller in the existing feeding and guiding process, thereby ensuring the strength of the bead.

[0034] (2) such as Figure 4 As shown, when applying the release film, release films are applied to the upper and lower surfaces of the bead wire wrapping fabric at the inner and outer ends of the bead wire wrapping fabric, respectively. The center of the release film on the lower surface of the inner end is attached to the inner end, and the center of the release film on the upper surface of the outer end is attached to the outer end. The outer end of the release film on the upper surface of the inner end is offset from the inner end of the bead wire wrapping fabric, and the outer end of the release film on the lower surface of the outer end is also offset from the outer end of the bead wire wrapping fabric. Specifically, the release films on the lower surface of the inner end, the upper surface of the inner end, and the lower surface of the outer end are applied first. The release film on the upper surface of the outer end is applied after the bead wire wrapping fabric is applied.

[0035] The inner and outer ends of the isolation film and the bead wire wrapping are staggered, which achieves a relatively smooth edge transition, which is conducive to the compaction of components during production and reduces the risk of delamination caused by non-compactness in this area.

[0036] (3) The forming process first involves bonding the sidewall composite, airtight layer composite, and fiber wrapping, and then bonding the bead wire wrapping. During bonding, the standard position of the inner end of the bead wire wrapping is first located using a positioning laser mark, and the inner end of the bead wire wrapping is bonded to the standard position. Then, the bead wire wrapping is bonded circumferentially. After bonding, the joint and compaction of the bead wire wrapping are performed. The standard position of the outer end of the bead wire wrapping is then located using a positioning laser mark. The deviation between the outer end of the bonded bead wire wrapping and the standard position is measured with a tape measure and found to be 2mm, which meets the standard of ≤2mm, indicating that the width and position of the bead wire wrapping meet the requirements. Then, an isolation film is bonded to the upper surface of the outer end of the bead wire wrapping. Subsequent pressing and weighting are performed, followed by pad bonding, shaping, tread pressing, reverse wrapping, and pressing to complete the tire blank forming.

[0037] A tire manufactured using the process described in this embodiment was randomly selected and subjected to a laboratory bead durability test. The test results are as follows: Figure 7 As shown, the final durability time is 87 hours and 22 minutes, meeting the design requirements, and the final bead performance is improved by more than 57% compared to Comparative Example 1. This indicates that the bead strength of tires produced using the process of this invention is significantly improved compared to existing processes.

[0038] Subsequently, the finished tires were inspected by X-ray. Based on the X-ray images, the height difference between the outer end and inner end of the upper mold of the bead wire wrapping and the height difference between the outer end and inner end of the lower mold were calculated to be 5mm, which meets the height difference standard for this model of finished tire.

[0039] The finished tire was confirmed by cross-sectional cutting. The height difference between the outer end and the inner end of the bead wire wrapping was measured after cutting, as shown in Table 2. This verifies that the height difference between the outer end and the inner end of the bead wire wrapping of the finished tire does indeed meet the standard.

[0040] Table 2

[0041]

[0042] As can be seen from Example 1 and Comparative Example 1, the process of the present invention improves the corresponding process operations by starting with the feeding and guiding method of the bead wire wrapping, the bonding method of the isolation film of the bead wire wrapping, and the bonding and positioning method of the bead wire wrapping, thereby improving the conformity of the quality of the bead part of the finished tire, solving the quality problems of early bead detachment and sidewall detachment during tire use, and increasing the overall service mileage of the tire.

[0043] Although the present invention has been described in detail with reference to the accompanying drawings and preferred embodiments, the invention is not limited thereto. Various equivalent modifications or substitutions can be made to the embodiments of the invention by those skilled in the art without departing from the spirit and essence of the invention, and such modifications or substitutions should all be within the scope of the invention. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the invention should also be covered within the protection scope of the invention. Therefore, the protection scope of the invention should be determined by the scope of the claims.

Claims

1. A process for ensuring tire bead strength, characterized in that, (1) When the bead wire wrapping is fed and guided, a background suppression photoelectric sensor and two correction guide rollers are installed between the feeding end transmission roller and the bonding end transmission roller. The correction guide rollers are located on both sides of the bead wire wrapping. The background suppression photoelectric sensor is electrically connected to the controller. (2) When applying the isolation film, the upper and lower surfaces of the bead wire wrapping cloth are respectively attached to the inner and outer ends of the bead wire wrapping cloth. The center of the isolation film on the lower surface of the inner end is attached to the inner end, and the center of the isolation film on the upper surface of the outer end is attached to the outer end. The outer end of the isolation film on the upper surface of the inner end is misaligned with the inner end of the bead wire wrapping cloth, and the outer end of the isolation film on the lower surface of the outer end is misaligned with the outer end of the bead wire wrapping cloth. (3) When bonding the bead wire wrapping cloth, first use the positioning laser mark to locate the standard position of the inner end of the bead wire wrapping cloth, and then bond the inner end of the bead wire wrapping cloth to the standard position. Then, bond the bead wire wrapping cloth circumferentially. After bonding, perform the joint and compaction operation of the bead wire wrapping cloth. Then, use the positioning laser mark to locate the standard position of the outer end of the bead wire wrapping cloth. Confirm whether the deviation between the outer end of the bonded bead wire wrapping cloth and the standard position meets the preset standard one. If it meets the standard, then bond the isolation film on the upper surface of the outer end of the bead wire wrapping cloth.

2. The process for ensuring tire bead strength as described in claim 1, characterized in that, It also includes a differential inspection step for the bead wire wrapping, which involves X-raying the finished tire and calculating the height difference between the outer and inner ends of the bead wire wrapping based on the X-ray image. If the height difference meets the preset standard two, the differential inspection of the bead wire wrapping of the finished tire is deemed qualified; otherwise, it is deemed unqualified.

3. The process for ensuring tire bead strength as described in claim 1, characterized in that, The outer end of the isolation film on the upper surface of the inner end point is misaligned with the inner end point of the bead wire wrapping cloth by 2-5mm, and the outer end point of the isolation film on the lower surface of the outer end point is misaligned with the outer end point of the bead wire wrapping cloth by 2-5mm.

4. The process for ensuring tire bead strength as described in claim 1, characterized in that, The preset standard is that the deviation between the outer end of the bead wire wrapping and the standard position after bonding is ≤2mm.

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