Structure for reducing air bubble occurrence rate of tire shoulder

Abstract

The utility model relates to a structure for reducing the occurrence rate of tire shoulder air bubbles, which relates to the technical field of tire forming and comprises a pair of capsule bodies, the two capsule bodies are symmetrically arranged on a middle shaft of a forming drum, each capsule body is of an inflatable hollow structure and is pear-shaped after being inflated, so that a tire bead part of a tire is more compactly pressed in the forming process, and the tire shoulder air bubble occurrence rate is reduced. And the residual quantity of gas in the tire blank is reduced, so that the occurrence rate of shoulder air bubbles is reduced from 850 ppm to 360 ppm, and the reduction amplitude reaches 58%.

Description

Technical Field

[0001] This utility model relates to the field of tire molding technology, specifically to a structure that reduces the occurrence rate of air bubbles on the tire shoulder. Background Technology

[0002] Air bubbles are one of the most common quality defects in tires. They not only directly affect the appearance quality of tires, but also pose a great potential hazard to tire safety performance, easily causing shoulder gaps, delamination, or even bursting.

[0003] Tire shoulder air bubbles refer to air bubbles present between the adhesive surfaces of internal components in the tire bead and sidewall. When inspected by X-ray, these appear as irregularly shaped bright white areas on the bead and sidewall. Tire shoulder air bubbles severely impact the finished product yield and tire performance, making the tire highly susceptible to delamination and, in severe cases, tire blowouts, posing a significant safety hazard.

[0004] To address the aforementioned issues, our research team designed a structure that reduces the incidence of shoulder air bubbles in tires. This structure ensures more thorough compression of the tire bead area, reduces the amount of residual gas inside the tire carcass, and thus lowers the incidence of shoulder air bubbles. Utility Model Content

[0005] In order to overcome the above-mentioned defects in the existing technology, the purpose of this utility model is to provide a reasonably designed and easy-to-use structure for reducing the occurrence rate of air bubbles on tire shoulders.

[0006] To achieve the above objectives, the present invention adopts the following technical solutions:

[0007] A structure for reducing the incidence of air bubbles on tire shoulders includes a pair of capsules symmetrically arranged on the central axis of a molded drum. The capsules are inflatable hollow structures that take on a pear shape when inflated.

[0008] Furthermore, when the capsule is inflated, the higher side is close to the central axis of the molding drum, and the highest point is located at 1 / 4 to 1 / 3 of the distance from the central axis of the molding drum.

[0009] Furthermore, the capsule body adopts a gradually varying wall thickness. When it is not inflated, it is laid flat on the molding drum, with the thickest wall thickness at both ends and the thinnest wall thickness at 1 / 4 to 1 / 3 of the distance from the central axis of the molding drum.

[0010] Furthermore, the higher side of the capsule body is close to the central axis of the forming drum, and the highest point is located at 1 / 3 of the distance from the central axis of the forming drum.

[0011] Furthermore, the capsule body adopts a gradually varying wall thickness. When it is not inflated, it is laid flat on the molding drum, with the thickest wall thickness at both ends and the thinnest wall thickness at about 1 / 3 of the distance from the central axis of the molding drum.

[0012] Furthermore, the distance between the forming drums of the two capsules during inflation is 80–110 mm.

[0013] Furthermore, the distance between the forming drums of the two capsules during inflation is 95 mm.

[0014] The beneficial effects of this utility model are as follows:

[0015] 1. By designing the capsule in the shape of a pear, and placing it closer to the bead at the highest point of the inflated tube, about 1 / 4 to 1 / 3 of the way from the center of the drum, the pressure on the bead area of ​​the tire carcass is increased by 20%-30%, resulting in a more compact bead seal, reducing the amount of residual gas inside the tire carcass, and lowering the incidence of shoulder air bubbles.

[0016] 2. The capsule body adopts a gradual wall thickness to avoid abrupt changes in wall thickness and a smooth transition to prevent tearing. When it is not inflated, it is laid flat on the molding drum. The walls are thickest at both ends to suppress expansion and maintain a narrow shape. The walls are thinnest at 1 / 4 to 1 / 3 of the distance from the central axis of the molding drum, so that it expands preferentially when inflated.

[0017] 3. After implementing this utility model in actual production, the incidence of shoulder air bubbles has been reduced from 850 ppm to less than 400 ppm for four consecutive months, showing a stable low incidence level. This effectively reduces the incidence of shoulder air bubbles, thereby improving production efficiency, reducing defect rate, and helping to improve production quality and economic benefits. Attached Figure Description

[0018] Figure 1 This is a diagram showing the inflated state of the capsule of this utility model;

[0019] Figure 2 This is a structural diagram of the molded drum capsule according to a specific embodiment of the present invention;

[0020] Figure 3 This is a diagram of the capsule of this utility model in its uninflated state;

[0021] Figure 4 This is a statistical chart showing the incidence of air bubbles in the shoulders before and after this utility model was put into use.

[0022] Explanation of reference numerals in the attached diagram: 1. Capsule body; 2. Central axis of the forming drum. Detailed Implementation

[0023] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The illustrative embodiments and descriptions of the present invention are used to explain the present invention, but are not intended to limit the present invention.

[0024] Example 1

[0025] The structure in this embodiment that reduces the incidence of air bubbles on the tire shoulder includes a pair of capsule bodies 1, which are symmetrically arranged on the central axis 2 of the molding drum. The capsule body 1 is an inflatable hollow structure that takes the shape of a pear after inflation. The higher side of the capsule body is close to the central axis of the molding drum, and the highest point is located at 1 / 4 of the distance from the central axis 2 of the molding drum, which is closer to the tire bead. This increases the pressure on the tire bead area of ​​the tire carcass by 20%-30%, making the tire bead area more compact and reducing the amount of residual gas inside the tire carcass.

[0026] Capsule body 1 features a gradually varying wall thickness to avoid abrupt changes and a smooth transition to prevent tearing. When uninflated, it lies flat on the molding drum. Figure 3 As shown, the walls are thickest at both ends, which suppresses expansion and maintains a narrow shape. The walls are thinnest at about 1 / 4 of the way down from the center of the drum, allowing it to expand preferentially during inflation.

[0027] The spacing between the forming drums when the capsule is inflated is 80mm, which improves the compression effect of the capsule body 1 on the material at the position of the embryo ring and reduces the amount of residual gas inside the embryo.

[0028] Example 2

[0029] The structure in this embodiment that reduces the incidence of air bubbles on the tire shoulder includes a pair of capsule bodies 1, which are symmetrically arranged on the central axis 2 of the molding drum. The capsule body 1 is an inflatable hollow structure that takes the shape of a pear after inflation. The higher side 2 of the capsule body is close to the central axis of the molding drum, and the highest point is located at 1 / 4 of the distance from the central axis 2 of the capsule body, which is closer to the tire bead. This increases the pressure on the tire bead area of ​​the tire carcass by 20%-30%, making the tire bead area more compact and reducing the amount of residual gas inside the tire carcass.

[0030] Capsule body 1 features a gradually varying wall thickness to avoid abrupt changes and a smooth transition to prevent tearing. When uninflated, it lies flat on the molding drum. Figure 3 As shown, the walls are thickest at both ends, which suppresses expansion and maintains a narrow shape. The walls are thinnest at about 1 / 4 of the way down from the center of the drum, allowing it to expand preferentially during inflation.

[0031] The spacing between the forming drums when the capsule is inflated is 110mm, which improves the compression effect of the capsule body 1 on the material at the position of the embryo ring and reduces the amount of residual gas inside the embryo.

[0032] Example 3

[0033] like Figures 1-2As shown, the structure for reducing the incidence of air bubbles on the tire shoulder in this embodiment includes a pair of capsule bodies 1. The two capsule bodies 1 are symmetrically arranged on the central axis 2 of the molding drum. The capsule body 1 is an inflatable hollow structure. After inflation, it takes the shape of a pear. The higher side 2 of the capsule body is close to the central axis of the molding drum, and the highest point is located at the center 1 / 3 of the capsule body 1 close to the central axis 2 of the molding drum, which is closer to the tire bead. This increases the extrusion pressure on the tire bead area of ​​the tire carcass by 20%-30%, making the tire bead area more compact and reducing the amount of residual gas inside the tire carcass.

[0034] Capsule body 1 features a gradually varying wall thickness to avoid abrupt changes and a smooth transition to prevent tearing. When uninflated, it lies flat on the molding drum. Figure 3 As shown, the walls are thickest at both ends, which suppresses expansion and maintains a narrow shape. The walls are thinnest at about 1 / 3 of the way down from the center of the drum, allowing it to expand preferentially during inflation.

[0035] The spacing between the forming drums when the capsule is inflated is 95mm, which improves the compression effect of the capsule body 1 on the material at the position of the embryo ring and reduces the amount of residual gas inside the embryo.

[0036] The working principle of this utility model is as follows: The capsule body 1 adopts a gradually changing wall thickness to avoid abrupt changes in wall thickness and a smooth transition to prevent tearing. When not inflated, it is laid flat on the forming drum, with the thickest walls at both ends to suppress expansion and maintain a narrow shape. The wall thickness is thinnest at 1 / 4 of the distance from the central axis of the forming drum, allowing it to expand preferentially during inflation. During the tire forming process, gas is introduced into the capsule body 1. As the air pressure increases, the capsule body 1 begins to expand. After the capsule body 1 expands to its maximum diameter, the higher side 2 of the capsule body is close to the central axis of the drum, and the highest point is located at 1 / 4 to 1 / 3 of the distance from the center of the central axis of the forming drum. The distance between the forming drums is 95-110mm. After inflation, the two capsule bodies 1, driven by the central axis 2 of the forming drum, play a role in squeezing and flipping the tire sidewall, thus completing the forming of the tire blank.

[0037] The structure provided by this utility model for reducing the incidence of tire shoulder air bubbles has a maximum position after inflation located on the inner side of the overall width of the capsule body, that is, at 1 / 4 to 1 / 3 of the distance from the center of the forming drum, which is closer to the tire bead. The spacing between the forming drums during capsule inflation is 95-110mm, which increases the extrusion pressure on the tire bead area by 20%-30%, making the tire bead area more compact and reducing the amount of residual gas inside the tire, thereby reducing the incidence of shoulder air bubbles.

[0038] Before the introduction of this invention, the average shoulder air bubble occurrence rate was above 850 ppm, indicating a high frequency of air bubble formation, which impacted production efficiency and product quality. After implementing this invention in actual production, the shoulder air bubble occurrence rate dropped below 400 ppm for four consecutive months, down from nearly 850 ppm. (See details...) Figure 4Specifically, the air bubble occurrence rates for the four consecutive months after implementation were 370, 360, 356, and 355, respectively, with an average occurrence rate of 360, representing a decrease of 58%, demonstrating a stable low occurrence rate. This significant improvement indicates that this invention has a significant advantage in reducing shoulder air bubble formation, effectively lowering the incidence of shoulder air bubbles, thereby improving production efficiency, reducing defect rates, and optimizing overall process performance, contributing to improved production quality and economic benefits.

[0039] Although the present invention has been described in detail above with general descriptions and specific embodiments, some modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A structure for reducing the incidence of air bubbles on tire shoulders, characterized in that, It includes a pair of capsule bodies (1), which are symmetrically arranged on the central axis (2) of the forming drum. The capsule body (1) is an inflatable hollow structure that takes the shape of a pear after being inflated.

2. The structure for reducing tire shoulder air bubble occurrence rate according to claim 1, characterized in that: When the capsule body (1) is inflated, the higher side is close to the central axis (2) of the forming drum, and the highest point is located at 1 / 4 to 1 / 3 of the distance between the capsule body (1) and the central axis (2) of the forming drum.

3. The structure for reducing the incidence of air bubbles on tire shoulders according to claim 2, characterized in that, The capsule body (1) has a gradually varying wall thickness. When it is not inflated, it is laid flat on the forming drum. The wall thickness is the thickest at both ends and the thinnest at 1 / 4 to 1 / 3 of the distance from the center axis (2) of the forming drum.

4. The structure for reducing the incidence of air bubbles on tire shoulders according to claim 2, characterized in that: The high side of the capsule body (1) is close to the central axis (2) of the forming drum, and the highest point is located at 1 / 3 of the distance between the capsule body (1) and the central axis (2) of the forming drum.

5. The structure for reducing the incidence of air bubbles on tire shoulders according to claim 4, characterized in that, The capsule body (1) has a gradually varying wall thickness. When it is not inflated, it is laid flat on the molding drum. The wall thickness is the thickest at both ends and the thinnest at 1 / 3 of the distance from the central axis (2) of the molding drum.

6. The structure for reducing the incidence of air bubbles on tire shoulders according to claim 1, characterized in that, The distance between the forming drums of the two capsule bodies (1) when they are inflated is 80-110 mm.

7. The structure for reducing the incidence of air bubbles on tire shoulders according to claim 1, characterized in that, The distance between the forming drums of the two capsule bodies (1) when they are inflated is 95 mm.

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