Process for improving the quality of carcass turn-up in narrow tires

Abstract

The present invention discloses a process for improving the quality of narrow-segment tire carcass turnup, belonging to the technical field of tire production. By adjusting the carcass lamination process, increasing post-pressing centering, carcass barrel transfer skew, equipment concentricity, the position of the finger-shaped device for positive carcass wrapping, and confirming the endpoint deviation after carcass turnup, the present invention effectively improves the stability and conformity of the carcass turnup quality of narrow-segment tires, thereby enhancing the tire's durability and extending its service life.

Description

Technical Field

[0001] The present invention relates to the technical field of tire production, and in particular to a process for improving the turn-up quality of a narrow tire carcass. Background Art

[0002] At present, in the production process of narrow-grade engineering radial tires, there are unreasonable aspects in the carcass bonding and turn-up process, and the quality of the turned-up carcass in the final tire is unstable and varies greatly. As a result, during the use of the tire, the turned-up carcass in the bead area is unevenly stressed, and early delamination of the turned-up carcass occurs, affecting the overall mileage of the tire. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the shortcomings of the existing technology and provide a process for improving the quality of the carcass turn-up of narrow tires, thereby effectively improving the stability and compliance of the carcass turn-up quality of narrow tires, thereby improving the durability of the tires and extending the service life of the tires.

[0004] The technical solution of the present invention is:

[0005] The process for improving the carcass turn-up quality of narrow tires includes the following steps:

[0006] S1: During the carcass production process of the cutting process, a center line is added in the width direction of the carcass. During the molding process, the airtight layer, isolation layer, film, bead wire cloth and other components are laminated and pressed in sequence according to the standard. The carcass is laminated in such a way that the center light mark line coincides with the center line. After that, the entire carcass tube is pressed. After pressing, it is confirmed whether the center line of the carcass tube coincides with the center line of the light mark, and the distance deviation is controlled to meet the preset standard one.

[0007] Adding a center marking operation to the carcass and fitting according to the center marking of the carcass is to ensure that the distance between the upper end point of the turned-up carcass and the outer end point of the wire cloth meets the designed standard distance during fitting; if the carcass fitting is skewed during this process, it will cause deviation between the two end points when the carcass is turned up, and the tire cannot be reworked, eventually causing the tire blank to be scrapped.

[0008] S2: After the carcass tube is transferred to the turn-up drum, the distance deviation between the center line of the carcass tube and the center light mark line of the turn-up drum station is controlled to meet the preset standard 2.

[0009] The purpose of adding a center deviation control step during the carcass tube transfer process is to ensure the consistency of the carcass width to be turned up on both sides of the carcass tube, and to prevent deviation in the carcass turn-up quality due to width deviation (the wider the carcass width, the greater the difficulty of turning up).

[0010] S3: Control the concentricity difference between the buckle plate and the drum at the drum turning station. Before starting the equipment, fully expand the drum to a cylindrical shape, then move the buckle plate at the drum turning station to the drum turning position, and measure the height from the upper end of the buckle plate to the drum turning, as well as the height from the lower end of the buckle plate to the drum turning, and control the difference between the two heights to meet the preset standard three.

[0011] This step is to control the concentricity deviation between the bead ring plate and the turn-up drum in order to ensure that the wire ring and the turn-up drum are concentric. If the concentricity does not meet the requirements, there will be a height difference between the tire body turn-up at the position with large concentricity deviation and the position with small concentricity deviation, causing the tire blank to be scrapped.

[0012] S4: Set the positive position of the finger to a distance of one carcass tube thickness from the front end of the turn-up drum; before performing the beading operation, adjust the light mark line to a position with a distance D from the front end of the turn-up drum, where D is the thickness of the carcass tube, and then operate the finger to move forward toward the turn-up drum until it reaches the position of the light mark line, and then operate the beading disk to perform beading, pressing and other operations.

[0013] The parametric design of the finger position ensures consistent grip on the tire during each beading process, ensuring a stable turn-up height. If the finger grip is too loose, the turn-up height will fall below the design standard. If the grip is too tight, the finger may deform or damage the tire wire, ultimately resulting in the tire being scrapped.

[0014] S5: After the carcass is turned up at the turn-up drum station, manually operate the finger to retract 5-30mm, then operate the turn-up drum to rotate 3-5°, and then operate the finger to perform a second push operation from the outer end point of the wire cloth to the upper end point of the turned-up carcass. During the first push, there is a gap between the fingers of the finger, which means the carcass is not turned up solidly. Therefore, after the first push, the turn-up drum is rotated, and a second push is performed when it is rotated to the position where the finger corresponds to the gap. This can ensure that the turned-up carcass in the gap between the fingers of the finger is also pushed, thereby ensuring the density of the root of the turned-up carcass; at this time, the outer end point of the wire cloth and the upper end point of the turned-up carcass can be intuitively seen, and the distance between the outer end point of the wire cloth and the upper end point of the turned-up carcass can be measured, and the difference between the distance between the two and the designed standard distance is controlled to meet the preset standard four.

[0015] Preferably, in step S1, the preset standard 1 is that the distance deviation between the center line of the carcass tube and the center line of the beacon is ≤ 2 mm.

[0016] Preferably, in step S2, the preset standard 2 is that the distance deviation between the center line of the carcass tube and the center light mark line of the turn-up drum station is ≤2 mm.

[0017] Preferably, in step S3, the preset standard three is that the difference between the two heights is ≤3 mm.

[0018] Preferably, in step S5, the preset standard four is that the difference between the distance between the outer end point of the wire cloth and the upper end point of the turned-up carcass and the designed standard distance is ≤15 mm.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The present invention effectively improves the stability and compliance of the carcass turn-up quality of narrow tires by adjusting the carcass lamination process, increasing the centering after pressing, the carcass tube transmission skew value, the equipment concentricity, the position of the finger-shaped device for positively wrapping the carcass, and confirming the endpoint deviation after the carcass is turned up, thereby improving the durability of the tire and extending the service life of the tire. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0022] Figure 1 Schematic diagram of the center line of the carcass of the present invention.

[0023] Figure 2 It is a schematic diagram of the height A from the upper end of the ring buckle disk to the turn-up drum and the height B from the lower end of the ring buckle disk to the turn-up drum after the ring buckle disk moves to the turn-up drum position in the present invention.

[0024] Figure 3 Schematic diagram of the setting position of the finger shape device of the present invention.

[0025] Figure 4 It is a schematic diagram of the upper end point of the turned-up carcass and the outer end point of the steel wire cloth of the carcass of the present invention.

[0026] In the figure, 1. carcass; 2. center line; 3. bead plate; 4. turn-up drum; 5. finger-type device; 6. outer end point of wire wrap; 7. upper end point of turn-up carcass. DETAILED DESCRIPTION

[0027] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0028] Example 1

[0029] The process for improving the carcass turn-up quality of a 33.00R51 tire in this embodiment includes the following steps:

[0030] S1: Cutting process During the production of carcass 1, Figure 1As shown, a center line 2 is added to the width direction of the carcass 1. During the molding process, the airtight layer, isolation layer, film, bead wire cloth and other components are sequentially laminated and pressed according to the standard. The carcass is laminated in such a way that the center light mark line coincides with the center line 2. After completion, the entire carcass tube is pressed. After pressing, the distance deviation between the center line 2 of the carcass tube and the center line of the light mark is 1mm.

[0031] S2: After the carcass tube is transferred to the turn-up drum 4, the distance deviation between the center mark 2 of the carcass tube and the center light mark line of the turn-up drum 4 station is measured to be 2 mm;

[0032] S3: If Figure 2 As shown, the buckle plate 3 is moved to the position of the turn-up drum 4 at the turn-up drum 4 station. The height A from the upper end of the buckle plate 3 to the turn-up drum 4 is measured to be 167 mm, and the height B from the lower end of the buckle plate 3 to the turn-up drum 4 is 169 mm. The difference between the two heights is 2 mm.

[0033] S4: Before the buckle ring operation, Figure 3 As shown, adjust the light mark line to a position with a distance D from the front end of the turn-up drum 4, where D is the thickness of the carcass tube (33 mm). Then operate the finger-shaped tool 5 to move forward toward the turn-up drum 4 until it reaches the position of the light mark line. Then operate the beading disc 3 to perform beading and pressing operations.

[0034] S5: After the carcass 1 is turned up at the turn-up drum 4, the finger 5 is manually retracted 20 mm, and then the turn-up drum 4 is operated to rotate 4 degrees, and then the finger 5 is operated to perform a secondary assist operation from the outer end point 6 of the wire cloth to the upper end point 7 of the turned-up carcass; Figure 4 As shown, at this time, the outer end point 6 of the wire cloth and the upper end point 7 of the turned-up carcass can be intuitively seen, and the distance between the outer end point 6 of the wire cloth and the upper end point 7 of the turned-up carcass is measured. The measurement results are shown in Table 1.

[0035] Table 1

[0036]

[0037] As shown in Table 1, the distance between the outer end point 6 of the wire cloth of the turned-up carcass prepared in Example 1 and the upper end point 7 of the turned-up carcass is ≤15 mm, which meets the control standard.

[0038] The tire of Example 1 was subjected to a durability test, and the test result was 231 hours, which met the internal control standard of ≥160 hours.

[0039] Comparative Example 1

[0040] The difference from Example 1 is that in step S1 , when the carcass 1 is attached, the attachment is performed in a manner that the edge light marking lines are aligned with the two edges of the carcass 1 .

[0041] After the carcass is turned up, the distance between the outer end point 6 of the wire cloth and the upper end point 7 of the turned-up carcass is measured. The measurement results are shown in Table 2.

[0042] Table 2

[0043]

[0044]

[0045] As shown in Table 2, the distance between the outer end point 6 of the steel wire cloth of the turned-up carcass prepared in Comparative Example 1 and the upper end point 7 of the turned-up carcass is greater than 15 mm, which does not meet the control standard.

[0046] The tire in Comparative Example 1 was tested for durability, resulting in a test result of 158.5 hours, which falls short of the internal control standard of ≥160 hours. This is because the width tolerance of the carcass 1 is ±4mm, resulting in a discrepancy between the width of the carcass 1 actually cut and the designed standard width. Consequently, when the carcass 1 is assembled according to the edge positioning method in Comparative Example 1, one side of the carcass 1 will align with the edge beacon line, while the other side will appear narrower than or extend beyond the edge beacon line. This ultimately results in a misalignment between the carcass 1 and the center of the tread during assembly, causing the turnup heights on both sides of the carcass 1 to exceed the preset standard of four. This results in the higher side of the turned-up carcass being more rigid than the lower side, ultimately leading to early delamination failure of the turned-up carcass on the lower side.

[0047] Comparative Example 2

[0048] The difference from Example 1 is that in step S2, after the carcass tube is transferred to the turn-up drum 4, the distance deviation between the center score line 2 of the carcass tube and the center light mark line of the turn-up drum 4 is measured to be 10 mm.

[0049] After the carcass is turned up, the distance between the outer end point 6 of the wire cloth and the upper end point 7 of the turned-up carcass is measured. The measurement results are shown in Table 3.

[0050] Table 3

[0051]

[0052] As shown in Table 3, the distance between the outer end point 6 of the steel wire cloth of the turned-up carcass prepared in Comparative Example 2 and the upper end point 7 of the turned-up carcass is greater than 15 mm, which does not meet the control standard.

[0053] The tire from Comparative Example 2 was tested for durability, resulting in a test result of 149 hours, which fell short of the internal control standard of ≥160 hours. This is because the center of the tire cylinder, after being transferred to the turn-up drum 4, became skewed, causing the carcass 1, sidewall reinforcement rubber, inner liner, and other components to become skewed. This resulted in asymmetric thicknesses in symmetrical areas of the tire and inconsistent carcass width distribution at both ends of the cylinder. This caused the higher side of the turned-up carcass to be more rigid than the lower side, ultimately leading to premature delamination and failure of the lower side.

[0054] Comparative Example 3

[0055] The difference from Example 1 is that in step S3, the ring buckle disk 3 is moved to the position of the turn-up drum 4 by operating the turn-up drum 4 workstation, and the height A=165mm from the upper end of the ring buckle disk 3 to the turn-up drum 4 is measured, and the height B=171mm from the lower end of the ring buckle disk 3 to the turn-up drum 4 is measured, and the difference between the two heights is 6mm.

[0056] After the carcass is turned up, the distance between the outer end point 6 of the wire cloth and the upper end point 7 of the turned-up carcass is measured. The measurement results are shown in Table 4.

[0057] Table 4

[0058]

[0059] As shown in Table 4, the distance between the outer end point 6 of the wire cloth of the turned-up carcass prepared in Comparative Example 3 and the upper end point 7 of the turned-up carcass is greater than 15 mm, which does not meet the control standard.

[0060] The tire of Comparative Example 3 was tested for durability, resulting in a test result of 155 hours, which fell short of the internal control standard of ≥160 hours. This is due to a deviation in the concentricity between the turn-up drum 4 and the bead plate 3, resulting in non-concentricity between the bead plate 3 and the drum 4. The wire ring, after being attached to the bead plate 3, is also non-concentric with the drum 4. In areas where the distance between the bead plate 3 and the drum is greater, the carcass turn-up height is higher, while in areas where the distance is less, the turn-up height is lower. Areas with higher carcass turn-up height have greater rigidity than areas with lower rigidity. This difference in circumferential rigidity of the sidewall can lead to repeated excessive flexing during tire rolling, ultimately causing premature delamination and failure of the turned-up carcass.

[0061] Comparative Example 4

[0062] The difference from Example 1 is that: in step S4, before performing the buckling operation, the light mark line is adjusted to a distance of 50 mm from the front end of the turn-up drum 4, and then the finger-shaped tool 5 is operated to move forward toward the turn-up drum 4 until it reaches the position of the light mark line, and then the buckling disk 3 is operated to perform buckling, pressing and other operations.

[0063] After the carcass is turned up, the distance between the outer end point 6 of the wire cloth and the upper end point 7 of the turned-up carcass is measured. The measurement results are shown in Table 5.

[0064] Table 5

[0065]

[0066] As shown in Table 5, the distance between the outer end point 6 of the steel wire cloth of the turned-up carcass prepared in Comparative Example 4 and the upper end point 7 of the turned-up carcass is greater than 15 mm, which does not meet the control standard.

[0067] The tire in Comparative Example 4 was tested for durability, resulting in a test result of 141 hours, which fell short of the internal control standard of ≥160 hours. This is because in Comparative Example 4, the distance between the finger 5 and the turn-up drum 4 was too great, resulting in a relatively loose grip of the tire carcass 1 by the finger 5. This resulted in a loose connection between the base of the turn-up drum 4 and the carcass barrel, and a loose connection between the bead rings and the carcass tube. This meant that the length of the carcass 1 between the bead rings was greater than the designed value. Given the same carcass 1 width, the overall height of the turned-up carcass was reduced, resulting in a decrease in tire sidewall rigidity and increased tire sinkage under load. This resulted in excessive deformation of the bead and sidewall, excessive flexing during rolling, and ultimately, premature delamination of the turned-up carcass.

[0068] Comparative Example 5

[0069] The difference from Example 1 is that in step S5, after the turning-up drum 4 completes the turning-up of the carcass 1, no secondary boosting operation is performed.

[0070] After the carcass is turned up, the distance between the outer end point 6 of the wire cloth and the upper end point 7 of the turned-up carcass is measured. The measurement results are shown in Table 6.

[0071] Table 6

[0072]

[0073] As shown in Table 6, the distance between the outer end point 6 of the wire cloth of the turned-up carcass prepared in Comparative Example 5 and the upper end point 7 of the turned-up carcass is greater than 15 mm, which does not meet the control standard.

[0074] The tire in Comparative Example 5 was tested for durability, resulting in a test result of 157 hours, which falls short of the internal control standard of ≥160 hours. This is because, after the carcass 1 is turned up in Comparative Example 5, the turn-up drum 4 is not rotated or the secondary assist operation is performed. The area between the fingers of the finger-shaped device 5, where no assist is performed, exhibits a loose turn-up of the carcass. Furthermore, during the vulcanization of the tire, the bead area is squeezed by the mold and inevitably becomes dense. This causes the bead wire to bend between the outer end point 6 of the wire wrap and the upper end point 7 of the turn-up carcass, resulting in approximately five strands of deformation. Stress concentration points develop at these bent wire locations during tire rolling, ultimately leading to premature bead delamination.

[0075] Although the present invention has been described in detail with reference to the accompanying drawings and in combination with preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and essence of the present invention, a person of ordinary skill in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and such modifications or substitutions shall be within the scope of the present invention. Any person skilled in the art who is familiar with the present invention may easily conceive of changes or substitutions within the technical scope disclosed in the present invention, and such changes or substitutions shall be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A process for improving the turn-up quality of narrow tire carcasses, characterized in that: The following steps are involved: S1: During the production of the carcass (1) in the cutting process, a center line (2) is added in the width direction of the carcass (1). During the molding process, each component is sequentially bonded and pressed. The carcass (1) is bonded in such a way that the center light line and the center line (2) coincide with each other. After the bonding is completed, the entire carcass tube is pressed. After the bonding is completed, it is confirmed whether the center line (2) of the carcass tube coincides with the center light line, and the distance deviation is controlled to meet the preset standard one. S2: After the carcass tube is transferred to the turn-up drum (4), the distance deviation between the center line (2) of the carcass tube and the center light mark line of the turn-up drum (4) is controlled to meet the preset standard 2; S3: The buckle plate (3) is moved to the position of the turn-up drum (4) at the turn-up drum (4) station operation, and the height from the upper end of the buckle plate (3) to the turn-up drum (4) and the height from the lower end of the buckle plate (3) to the turn-up drum (4) are measured respectively, and the difference between the two heights is controlled to meet the preset standard three; S4: Before the beading operation, the light mark line is adjusted to a position where the distance D from the front end of the turn-up drum (4) is the thickness of the carcass tube, and then the finger (5) is moved forward toward the turn-up drum (4) until it reaches the position of the light mark line, and then subsequent operations are carried out; S5: After the carcass (1) is turned up at the turn-up drum (4), the finger (5) is retracted, and then the turn-up drum is operated to rotate 3-5 degrees, and then the finger (5) is operated to perform a secondary boosting operation from the outer end point (6) of the wire cloth to the upper end point (7) of the turned-up carcass; at this time, the distance between the outer end point (6) of the wire cloth and the upper end point (7) of the turned-up carcass is measured, and the difference between the distance between the two and the designed standard distance is controlled to meet the preset standard four.

2. The process for improving the turn-up quality of narrow tire carcasses according to claim 1, wherein: In step S1, the preset standard 1 is that the distance deviation between the center line (2) of the carcass tube and the center light mark line is ≤ 2 mm.

3. The process for improving the turn-up quality of narrow tire carcasses according to claim 1, wherein: In step S2, the preset standard 2 is that the distance deviation between the center line (2) of the carcass tube and the center light mark line of the turn-up drum (4) station is ≤ 2 mm.

4. The process for improving the turn-up quality of narrow tire carcasses according to claim 1, wherein: In step S3, the preset standard three is that the difference between the two heights is ≤3 mm.

5. The process for improving the turn-up quality of narrow tire carcasses according to claim 1, wherein: In step S5, the preset standard four is that the difference between the distance between the outer end point (6) of the wire cloth and the upper end point (7) of the turned-up carcass and the designed standard distance is ≤15mm.

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