Airtight layer roller and airtight layer

Abstract

The present invention relates to the field of tire component production, specifically a roller for forming an airtight layer and an airtight layer. The roller comprises a central cylindrical body, on which a first side slope transition trapezoidal column, a second side slope transition trapezoidal column, and a side cylinder are symmetrically and coaxially arranged in sequence. The diameter of the roller's cross section increases from the central cylinder to the side cylinder, sequentially transitioning through the first side slope transition trapezoidal column and the second side slope transition trapezoidal column. The roller of the present invention achieves uniform distribution of airtight layer material at all points in the tire, preventing air pockets at the end points of the airtight layer and reducing the occurrence of bubbles at the sub-mouth.

Description

Technical Field

[0001] The invention belongs to the field of tire component production, and in particular relates to an airtight layer roller and an airtight layer. Background Art

[0002] Tires are essential components for vehicles like cars and trucks, and the performance of these vehicles is closely linked to the characteristics of the tires. The innerliner within a tire maintains tire pressure. Tubeless innerliners, in particular, act like inner tubes and are crucial for tire safety. They ensure that if a tire becomes underinflated on a highway, it can be driven to a safe area, preventing accidents.

[0003] The expansion coefficients of various material points vary from tire to finished product, with the crown and shoulder expanding the most, while the bead expands almost non-existently. Therefore, during the design of the semi-finished innerliner, the thickness dimensions at each point must be considered in conjunction with the material distribution diagram of the finished product, taking into account the expansion coefficients at each point to ensure a reasonable size distribution at each point in the finished tire. Furthermore, the edge of the tire's innerliner typically lands midway between the tire toe and the bead. A thicker edge can easily create a risk of air trapping in this area, so the design process must consider both the proper material distribution and a smooth transition along the innerliner edge.

[0004] Taking the 12R22.5 specification as an example, the thickness of the airtight layer in the middle and side parts of the tire crown meets the design requirements. However, due to the limitation of the prototype roller size, the edge thickness of the semi-finished product airtight layer is more than 2.1mm. During the molding process, there is a triangular area air pocket problem at the end point of the airtight layer. During the vulcanization process, the gas in this area cannot be dispersed, which will lead to the occurrence of bubbles at the mouth of the finished tire. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an airtight layer roller to reduce the occurrence of tire mouth bubble problem.

[0006] Another aspect of the present invention provides an airtight layer.

[0007] The present invention adopts the following technical solutions:

[0008] A type of airtight layer roller, comprising a middle cylinder, on both sides of which are symmetrically and coaxially provided with a first side slope transition trapezoidal column, a second side slope transition trapezoidal column and a side cylinder, wherein the diameter of the cross section of the roller increases from the middle cylinder to the side cylinder through the first side slope transition trapezoidal column and the second side slope transition trapezoidal column.

[0009] Furthermore, the difference between the radius of the top surface and the radius of the bottom surface of the first side slope transition trapezoidal column is 1.3-1.5 mm.

[0010] Furthermore, the difference between the radius of the top surface and the radius of the bottom surface of the second side slope transition trapezoidal column is 0.8mm-1.0mm.

[0011] Furthermore, the height of the middle cylinder is 300 mm, the height of the first side slope transition trapezoidal column is 160 mm, and the height of the second side slope transition trapezoidal column is 35 mm.

[0012] Furthermore, the total height of the forming roller is: 1300mm.

[0013] An airtight layer comprises a middle portion and a bilaterally symmetrical structure with the center line of the middle portion as the symmetry axis, wherein one side of the middle portion comprises a first transition oblique portion, a second transition oblique portion, and an end portion.

[0014] Furthermore, the thickness of each part of the airtight layer from the surface to the bottom plane is: 3.5-3.6mm in the middle part; 1.3mm on both sides of the end; the first transition slope is a slope structure, and the thickness difference between the thickest end and the thinnest end is 1.3-1.5mm; the second transition slope is a slope structure, and the thickness difference between the thickest end and the thinnest end is 0.8mm-1.0mm.

[0015] Furthermore, the total length of the airtight layer is 1300 mm, the length of the middle portion is 300 mm, the length of the first transition slope is 160 mm, and the length of the second transition slope is 35 mm.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] By optimizing the inner liner edge platform from one portion to a sloped transition and thinning the remaining two portions, a smooth transition at the inner liner endpoints is ensured while ensuring a reasonable material distribution across all areas. This significantly reduces the incidence of bubbles at the sub-ends, from the original 0.86% to 0.12%. The roller of this invention achieves uniform distribution of inner liner material at all points in the tire, preventing air pockets at the inner liner endpoints and reducing the occurrence of bubbles at the sub-ends. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of the structure of the airtight layer roller;

[0019] Figure 2 Schematic diagram of the structure of the airtight layer;

[0020] Figure 3 This is a comparison test chart of the improvement effect of sub-mouth bubbles. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0022] See also Figure 1 As shown, an airtight layer roller comprises a central cylindrical body 14. A first side slope transition trapezoidal column 13, a second side slope transition trapezoidal column 12, and a side cylinder 11 are symmetrically and coaxially arranged on either side of the central cylinder. The other side has the same structure. The roller has a circular cross-section, and its diameter increases from the central cylinder to the side cylinders, sequentially through the first and second side slope transition trapezoidal columns. A cross-section along the roller's axis reveals that the roller's outer surface has two platform sections at each end and a single platform in the middle. Two inclined surfaces of varying slopes transition from the central platform to the two end platforms.

[0023] The difference between the radius of the top surface and the radius of the bottom surface of the first side slope transition trapezoidal column is 1.3-1.5 mm, preferably 1.4 mm.

[0024] The difference between the radius of the top surface and the radius of the bottom surface of the second side slope transition trapezoidal column is 0.8mm-1.0mm, preferably 0.8mm.

[0025] In a preferred embodiment, the height of the middle cylinder is 300 mm, the height of the first side slope transition trapezoidal column is 160 mm, and the height of the second side slope transition trapezoidal column is 35 mm. The total height of the forming roller is 1300 mm.

[0026] The present invention provides an airtight layer, which includes a middle portion 24 and a bilaterally symmetrical structure with the center line of the middle portion as the symmetry axis. One side of the middle portion includes a first transition oblique portion 23, a second transition oblique portion 22, and an end portion 21.

[0027] The thickness of each part of the airtight layer from the surface layer to the bottom layer plane is: 3.5-3.6mm in the middle part; 1.3mm on both sides of the end portion; the first transition oblique portion is an oblique structure, and the thickness difference between the thickest end and the thinnest end is 1.3-1.5mm, preferably 1.4mm; the second transition oblique portion is an oblique structure, and the thickness difference between the thickest end and the thinnest end is 0.8mm-1.0mm, preferably 0.8mm.

[0028] The total length of the airtight layer is 1300 mm, the length L1 of the middle portion is 300 mm, the first transition slope L2 is 160 mm, and the second transition slope L3 is 35 mm.

[0029] The middle cylinder of the airtight layer roller and the first side slope transition trapezoidal column and the second side slope transition trapezoidal column correspond to the tire crown shoulder and side airtight layer parts in the tire material distribution diagram. This part is the area with the largest inflation deformation during tire manufacturing and use, and is also the area with the greatest force. The present invention uses the structure of the first side slope transition trapezoidal column and the second side slope transition trapezoidal column to ensure that small changes in the corresponding material size of this structural part will not affect the tire performance, but the change will ensure uniform transition of the components, which can improve the appearance quality of the tire and increase the one-time pass rate of the finished tire.

[0030] See also Figure 3 As shown in the figure, a comparative test on the improvement effect of the sub-mouth bubbles was conducted. The incidence of sub-mouth bubbles was significantly reduced.

[0031] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An airtight layer roller, characterized in that: The forming roller includes a middle cylinder, and a first side slope transition trapezoidal column, a second side slope transition trapezoidal column, and a side cylinder are symmetrically and coaxially arranged on both sides of the middle cylinder. The diameter of the cross section of the forming roller increases from the middle cylinder to the side cylinder through the first side slope transition trapezoidal column and the second side slope transition trapezoidal column. The height of the middle cylinder is 300 mm, the height of the first side slope transition trapezoidal column is 160 mm, and the height of the second side slope transition trapezoidal column is 35 mm. The difference between the radius of the top surface and the radius of the bottom surface of the first side slope transition trapezoidal column is 1.3-1.5mm; The difference between the radius of the top surface and the radius of the bottom surface of the second side slope transition trapezoidal column is 0.8mm-1.0mm; The thickness of the formed airtight layer at both ends is 1.3 mm.

2. The forming roller according to claim 1, characterized in that The total height of the forming roller is: 1300mm.

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