阅读说明：本技术 子午线轮胎及提升轮胎均匀性lfv指标的冠带条缠绕方法 (Radial tire and crown band winding method for improving tire uniformity LFV index ) 是由 齐格弗里德·拉策堡 陈卫勇 刘超 于 2020-04-07 设计创作，主要内容包括：本发明属于轮胎制造技术领域,针对冠带条分布不一致、不对称,造成行驶时周向强度不一致,形变不一致,轮胎的均匀性性能下降明显的上述问题,本发明提供一种子午线轮胎,冠带条的起始端和结束端的在轮胎周向位置上错位180°；本发明还提供一种提升轮胎均匀性LFV指标性能的冠带条缠绕方法,以冠带条的一端为起始端,从胎体左侧开始原地缠绕一圈进行锁圈,螺旋缠绕*.5圈,*为自然数,至胎体右侧并原地缠绕一圈锁圈,结束缠绕,冠带条的起始端和结束端在轮胎周向位置上错位180°；为保证冠带条的中线与胎体中线重合,事先计算用缠绕圈数＝(A-D)/B,调整相关参数。通过调整冠带条头尾分布的方法,减少材料的不均匀程度,提升均匀性特别是LFV指标的性能。(The invention belongs to the technical field of tire manufacturing, and provides a radial tire aiming at the problems that the circumferential strength is inconsistent, the deformation is inconsistent and the uniformity performance of the tire is obviously reduced due to inconsistent and asymmetric distribution of crown band strips, wherein the starting end and the ending end of the crown band strips are staggered by 180 degrees in the circumferential position of the tire; the invention also provides a winding method of the crown band strip for improving the LFV index performance of the tire uniformity, which takes one end of the crown band strip as a starting end, winds a circle in situ from the left side of a tire body for locking, winds the crown band strip for 5 circles in a spiral way, and winds a circle of locking ring in situ from the right side of the tire body for finishing winding, wherein the starting end and the finishing end of the crown band strip are staggered by 180 degrees in the circumferential direction of the tire; in order to ensure that the midline of the crown band coincides with the midline of the carcass, the winding turns (A-D)/B are calculated in advance, and relevant parameters are adjusted. By adjusting the head-tail distribution of the crown band strip, the non-uniform degree of the material is reduced, and the uniformity, particularly the performance of LFV indexes, is improved.)

1. A radial tire comprises a tire body, a belt ply, a crown band ply and a tire tread, wherein the belt ply is arranged on the tire body, the crown band ply is spirally wound on the belt ply, the edges of the crown band ply are wound on two sides of the tire body, and the center line of the crown band ply is superposed with the center line of the tire body, and is characterized in that the starting end and the finishing end of the crown band ply are staggered by 180 degrees in the circumferential direction of the tire.

2. A single-layer flat-laying type or double-layer flat-laying type cap strip winding method for improving tire uniformity LFV indexes is characterized by comprising the following steps:

positioning the position of the initial end of the crown band strip at a position (A-D)/2 away from the left side of the center of the tire tread, and winding a circle in situ to lock the ring, wherein A is the total width of the crown band strip, and D is the single width of the crown band strip;

step two, starting to lay flat and wind to the right of each circle of spiral stroke B to a position (A-D)/2 away from the right side of the center of the tread, wherein the winding spiral angle alpha is (A-D)/B360 degrees; in order to ensure that the circumferential positions of the head and the tail of the wound crown band are staggered by 180 degrees, the winding number of the crown band is set to be 5 circles, which is a natural number, and relevant parameters are adjusted through a formula of the winding number of the crown band being (A-D)/B;

and step three, positioning the end position of the crown band strip at the position (A-D)/2 away from the right side of the center of the tire tread, and winding for 360 degrees in situ to lock the ring.

3. A shoulder double-layer S-shaped or double-layer S-shaped crown strip winding method for improving tire uniformity LFV indexes is characterized by comprising the following steps:

positioning the initial end position of a crown band at a position A/2- (C-D/2) away from the left side of the center of a tread, and directly winding the crown band leftwards by a spiral stroke B, wherein the winding angle is (C-D/2)/B360 degrees; taking an integer value from the calculation result of the (C-D/2)/B numerical value; a is the total width of the cap strip, and C is the width of the double-layer cap strip on one side of the tread;

winding a circle of locking ring at the starting end of the crown band;

step three, each circle of spiral stroke B is horizontally paved and wound rightwards to a position (A-D)/2 away from the right side of the center of the tread, and the winding spiral angle is (A-D)/B360 degrees; in order to ensure that the circumferential positions of the head and the tail of the wound crown band are staggered by 180 degrees, the winding number of the crown band is set to be 5 circles, which is a natural number, and relevant parameters are adjusted through a formula of the winding number of the crown band being (A-D)/B;

winding a circle of locking ring at the position (A-D)/2 away from the right side of the center of the tire tread;

and step five, winding the steel wire left by each spiral stroke B (C-D/2)/B360 degrees.

4. A shoulder double-layer flat-laying type crown strip winding method for improving tire uniformity LFV indexes is characterized by comprising the following steps:

positioning the position of the initial end of the crown band strip at a distance of (A-D)/2 from the left side of the center of the tire tread, winding a circle in situ for serging, wherein A is the total width of the crown band strip, and D is the single width of the crown band strip;

step two, each circle of spiral stroke B is horizontally paved and wound rightwards, and the winding angle is (C-D/2)/B360 degrees; taking an integer value from the calculation result of the (C-D/2)/B numerical value; c is the width of the double-layer cap strip on one side of the tread;

step three, each circle of spiral stroke B is horizontally paved and wound rightwards, and the winding angle is (A-2C)/B360 degrees; the result of the numerical calculation of (A-2C)/B is taken as 5 circles, which is a natural number;

step four, each circle of spiral stroke B is horizontally paved and wound rightwards, and the winding angle is (C-D/2)/B360 degrees; taking an integer value from the calculation result of the (C-D/2)/B numerical value;

and 5, winding a circle of locking ring at the position (A-D)/2 away from the right side of the center of the tire tread.

Technical Field

The invention belongs to the technical field of tire manufacturing, and particularly relates to a radial tire and a crown band winding method for improving tire uniformity LFV index.

Background

The crown strip material plays a role in restraining the stretching of a belted layer in the tire and reducing the deformation of the tire. The spiral winding mode is a common attaching mode of the crown band strip in the tire manufacturing process at present. The spiral winding pattern includes five forms, as shown in fig. 1. The spirally wound crown band strip needs to be provided with a circle of locking edges at the edges to ensure the consistency of the total width of the whole circumference after the crown band strip is wound, but simultaneously, the crown band strip material is unevenly distributed at the two edges, the partial area is single-layer, the partial area is double-layer, and the width of the double-layer area is different. The method is introduced in a simplest single-layer flat-laying type winding form and comprises the following steps that firstly, the initial position of the crown band is positioned at the distance (A/2-D/2) mm from the left side of the center, and the crown band is wound in situ for 360 degrees; step two, starting to lay flat and wind to the right edge of the total width of the crown band strip from each circle of spiral stroke (B) mm to the right, wherein the winding spiral angle is (A-D)/B360;

and step three, positioning the initial position of the crown band strip at a distance (A/2-D/2) mm from the right side of the center, and winding the crown band strip for 360 degrees in situ.

At present, the winding mode of the crown band strip mainly meets the requirement of the whole width or the thread pitch, and the consistency of the total width of the whole circumference is ensured.

The uniformity of the tire directly influences the operation stability and the driving safety of the vehicle, and the improvement of the uniformity index of the tire has important significance. LFV is an important mechanical property index for measuring tire uniformity. The reasons why LFV is considered to be large by current research include: (1) semi-finished parts: firstly, the width of the tread is varied or the tread is snakelike and twisted when being extruded and stored; secondly, changing the width and angle of the belted layer or performing snake-shaped distortion; variation of the thickness or width of the belt cushion rubber; fourthly, the thickness and the height of the triangular glue are not uniform or the left side and the right side are not uniform. (2) The molding process comprises the following steps: firstly, the forming of the tread is inclined or partially inclined and twisted; secondly, width and angle variation is caused by snake-shaped distortion or feeding stretching when the belt layers are attached; thirdly, the belt layer cushion rubber is attached to be inclined or stretched in the forming process, and the size of the belt layer cushion rubber is varied; fourthly, the two-section forming drum shakes or swings to make the first-section tire blank incline when being fixed; the belt drum and the transfer ring rock or swing, and the transfer ring is asymmetric with the two-section forming center when clamping the belt layer and the tire tread to move; sixthly, the body ply has inclined reverse wrap and large reverse wrap height variation; seventhly, the steel wire ring shifts when the steel wire ring is inclined or reversely wrapped; eighthly, poor pressing of a press roller of the first-stage and second-stage forming machines causes the left and right materials of the green tire to be asymmetrical; (3) and (3) a vulcanization process: firstly, the deformation of the tire blank causes the incorrect vulcanization and shaping. Secondly, the shaping pressure is too large, the outer circumference of the tire blank exceeds the standard, and the tire crown center line of the vulcanized tire is fuzzy, deformed and even disappeared; the temperature difference between the upper part and the lower part of the vulcanization mould is large, so that the vulcanization degree of the upper part and the lower part of the vulcanized tire is inconsistent; fourthly, local edge emergence of the tire caused by poor vulcanization mold closing is required to adjust the mold closing force or the assembly precision of the mold; insufficient processing precision of the vulcanization mould, asymmetric upper and lower sizes or local pattern block deformation (see: tire uniformity and influence factors, the rest of double jade, tire industry, 2008 8 th).

In the research process, the inventor of the patent application finds that the materials of the left and right sides of the crown band strip are distributed in the circumferential direction and in the symmetrical position, the partial area crown band strip is single-layer and partial double-layer, the thickness and the mass distribution are not uniform, and the binding strength is not uniform. Taking a typical flush head and tail as an example, as shown in a circumferential development (fig. 2) after a crown band is wound, dark double-layer areas are concentrated together, left and right asymmetry is in a descending state, and the quality and intensity distribution are obviously uneven. The crown band material is distributed inconsistently and asymmetrically, which causes the inconsistentness of circumferential strength and deformation during running, and the uniformity performance of the tire is reduced, especially the LFV index performance is obviously reduced.

Disclosure of Invention

Aiming at the problems that the circumferential strength is inconsistent, the deformation is inconsistent and the uniformity performance of the tire is obviously reduced when the crown band material is distributed inconsistently and asymmetrically, the invention provides a radial tire, wherein the starting end and the finishing end of the crown band are staggered by 180 degrees on the circumferential position of the tire, and the whole circumferential difference of a double-layer area is minimum; the invention also provides a crown band strip winding method for improving the LFV index performance of the uniformity of the tire, which reduces the non-uniform degree of materials by adjusting the head and tail distribution of the crown band strip, makes up for improvement and improves the uniformity, particularly the LFV index performance.

The invention provides a radial tire, which comprises a tire body, a belt ply, a crown band strip and a tire tread, wherein the belt ply is arranged on the tire body, the crown band strip is spirally wound on the belt ply, the edges of the crown band strip are wound on two sides of the tire body, the central line of the crown band strip is superposed with the central line of the tire body, and the starting end and the finishing end of the crown band strip are staggered by 180 degrees in the circumferential position of the tire.

Theoretical analysis and multiple examples prove that the crown band is staggered by 180 degrees in the circumferential direction of the head and the tail after being wound, the method is the most uniform method for material distribution, the uniformity performance of the tire can be greatly improved, particularly the LFV index is improved, and the average 3kgf is reduced.

The invention also provides a single-layer flat laying type or double-layer flat laying type crown strip winding method for improving the LFV index performance of the uniformity of a tire, which comprises the following steps:

positioning the position of the initial end of the crown band strip at a position (A-D)/2 away from the left side of the center of the tire tread, and winding a circle at 360 degrees in situ to lock the ring, wherein A is the total width of the crown band strip, and D is the single width of the crown band strip;

step two, starting to lay flat and wind to the right of each circle of spiral stroke B to a position (A-D)/2 away from the right side of the center of the tread, wherein the winding spiral angle alpha is (A-D)/B360 degrees; in order to ensure that the circumferential positions of the head and the tail of the wound crown band are staggered by 180 degrees, the winding number of the crown band is set to be 5 circles, which is a natural number, and relevant parameters are adjusted through a formula of the winding number of the crown band being (A-D)/B;

and step three, positioning the end position of the crown band strip at the position (A-D)/2 away from the right side of the center of the tire tread, and winding for 360 degrees in situ to lock the ring.

The invention also provides a shoulder double-layer S-shaped or double-layer S-shaped crown band winding method for improving the LFV index of the tire uniformity, which comprises the following steps:

positioning the initial end position of a crown band at a position A/2- (C-D/2) away from the left side of the center of a tread, and directly winding the crown band leftwards by a spiral stroke B, wherein the winding angle is (C-D/2)/B360 degrees; taking an integer value from the calculation result of the (C-D/2)/B numerical value; a is the total width of the cap strip, and C is the width of the double-layer cap strip on one side of the tread;

winding a circle of 360 degrees at the starting end of the crown band strip;

step three, each circle of spiral stroke B is horizontally paved and wound rightwards to a position (A-D)/2 away from the right side of the center of the tread, and the winding spiral angle is (A-D)/B360 degrees; in order to ensure that the circumferential positions of the head and the tail of the wound crown band are staggered by 180 degrees, the winding number of the crown band is set to be 5 circles, which is a natural number, and relevant parameters are adjusted through a formula of the winding number of the crown band being (A-D)/B;

winding a circle of 360 degrees at the position which is away from the right side (A-D)/2 of the center of the tread;

and step five, winding the steel wire left by each spiral stroke B (C-D/2)/B360 degrees.

The invention also provides a shoulder double-layer flat-laid type crown band strip winding method for improving the LFV index of the tire uniformity, which comprises the following steps:

positioning the position of the initial end of the crown band strip at a distance of (A-D)/2 from the left side of the center of the tire tread, and winding a circle in situ to lock the crown band strip, wherein A is the total width of the crown band strip, and D is the single width of the crown band strip;

step two, each circle of spiral stroke B is horizontally paved and wound rightwards, and the winding angle is (C-D/2)/B360 degrees; taking an integer value from the calculation result of the (C-D/2)/B numerical value; c is the width of the double-layer cap strip on one side of the tread;

step three, each circle of spiral stroke B is horizontally paved and wound rightwards, and the winding angle is (A-2C)/B360 degrees; the result of the numerical calculation of (A-2C)/B is taken as 5 circles, which is a natural number;

step four, each circle of spiral stroke B is horizontally paved and wound rightwards, and the winding angle is (C-D/2)/B360 degrees; taking an integer value from the calculation result of the (C-D/2)/B numerical value;

and 5, winding 360 degrees at a position which is away from the right side (A-D)/2 of the center of the tread.

Through the steps, the distribution of 180-degree dislocation at the circumferential positions of the head and the tail of the wound crown band strip can be realized. The whole circumferential difference of the double-layer area after winding is minimum, and the bilateral symmetry difference is obviously reduced.

The invention is simple and easy to implement: through a detailed setting method, the expected effect can be achieved only by adjusting equipment parameters, and the operation and the adjustment are convenient; the method greatly improves the uniformity of the LFV index of the tire, can improve the controllability, reduce the noise, reduce abnormal abrasion and vehicle shaking, further reduce the fuel consumption, prolong the service life of the tire, furthest meet the customer demand, improve the potential value of the brand, increase the competitiveness of enterprises and reduce the environmental pollution.

Drawings

FIG. 1 is a schematic view of a prior art crown band winding; wherein: the total width of the crown band strips A, the spacing between the crown band strips a, the winding pitch of the crown band strips B, the width of the double-layer crown band strips on one side of the tread C, the single width of the crown band strips D and the arrow indicating the winding direction;

FIG. 2 is a circumferential development view of a conventional single-layer flat type winding effect;

FIG. 3 is a circumferential development view of the adjusted single-layer flat type winding effect of example 1;

FIG. 4 normal distribution diagram of LFV forward rotation value and LFV reverse rotation value after adjustment in example 1;

fig. 5 is a graph showing the change tendency of the daily rate of a-products before and after adjustment in example 1.

Detailed Description

The method is verified for a plurality of times for the winding forms of the crown band strips shown in the figure 1, and is actually implemented, so that the uniformity, particularly the LFV index performance is improved greatly and stably. The invention is explained in more detail below with reference to the examples and the figures.