阅读说明：本技术 一种改善胎体帘线伸张率的全钢子午线轮胎 (All-steel radial tire capable of improving elongation rate of tire cord ) 是由 杨奔 于 2020-12-29 设计创作，主要内容包括：本发明公开了一种改善胎体帘线伸张率的全钢子午线轮胎,涉及子午线轮胎领域,本发明结构简单,通过对胎体帘线伸张率范围的限定,使本发明相较于现有技术,对应调整了胎体成型的平面宽,增加了胚胎内胎体帘线长度,减少胎体帘线的抽动量和时间,在避免出现成品胎出现帘线弯曲、胎里不平等缺陷的前提下,使胎胚侧部在硫化定型过程中与模具侧板快速的紧密吻合,通过胶囊对胚胎的定型压力作用形成对硫化胶囊的挤压,消除气泡的集中空间,使胚胎侧部气泡均匀分散,降低了轮胎制造过程中的胎侧烂洞废次品率,同时提升了产品性能和寿命。(The invention discloses an all-steel radial tire for improving the elongation rate of tire body cords, which relates to the field of radial tires and has a simple structure, and by limiting the elongation rate range of the tire body cords, compared with the prior art, the invention correspondingly adjusts the plane width of tire body forming, increases the length of the tire body cords in the tire body, reduces the pumping quantity and time of the tire body cords, ensures that the side parts of the tire body are quickly and tightly matched with side plates of a mold in the vulcanization forming process on the premise of avoiding the defects of cord bending, unevenness and the like of a finished tire, and forms the extrusion of vulcanization capsules under the forming pressure action of the capsules on the tire body, eliminates the concentrated space of bubbles, ensures that the bubbles at the side parts of the tire body are uniformly dispersed, reduces the defective rate of tire side rotten holes in the tire manufacturing process, and simultaneously improves the product performance and the service life.)

1. An all-steel radial tire for improving the elongation of a carcass cord, the tire comprises an embryo assembled in a forming drum, the embryo is characterized in that the embryo comprises a steel cord, the length of the carcass cord between the inner end points of upper and lower die steel rings of the embryo is 2ab, the length of the carcass cord between the inner end points of the upper and lower die steel rings of the forming drum is 2a 'b', and the calculation formula of the elongation of the carcass cord of the embryo is as follows: when t is (2ab-2a 'b')/2 a 'b' x 100%, and the tire specification is 285/70R19.5, the elongation of the embryo carcass cord of the tire is in the range of: t is more than or equal to 1.74 percent and less than or equal to 2.48 percent, and when the tire specification is 265/70R19.5, the elongation rate of the embryo carcass cord of the tire is in the range of: t is more than or equal to 1.02 percent and less than or equal to 1.81 percent, and when the tire specification is 245/70R19.5, the elongation rate of the embryo carcass cord of the tire is in the range of: t is more than or equal to 1.06 percent and less than or equal to 2.76 percent, and when the tire specification is 225/70R19.5, the elongation rate of the embryo carcass cord of the tire is in the range of: t is more than or equal to 1.15 percent and less than or equal to 2.08 percent.

2. The all-steel radial tire for improving the elongation of the carcass cord as claimed in claim 1, wherein the tire has a flat width of 285/70R 19.5: 574 and 582 mm.

3. The all-steel radial tire for improving the elongation of the carcass cord as claimed in claim 1, wherein the tire has a flat width of 265/70R 19.5: 540 and 548 mm.

4. The all-steel radial tire for improving the elongation of the carcass cord as claimed in claim 1, wherein when the tire specification is 245/70R19.5, the flat surface width range of the tire blank is: 500-.

5. The all-steel radial tire for improving the elongation of the carcass cord as claimed in claim 1, wherein when the tire specification is 225/70R19.5, the flat surface width range of the tire blank is: 452 and 460 mm.

Technical Field

The invention relates to the field of radial tires, in particular to an all-steel radial tire capable of improving the elongation of tire body cords.

Background

In the prior art, a 19.5-inch low-flatness series of all-steel radial tires are high-quality products with rotten holes on the tire side. The reasons are mainly as follows:

1. the extrusion part and the framework material in the production are not compact and have air holes;

2. the 19.5-inch low-flatness tire side has a small deformation area, the end points of components such as cushion rubber, apex rubber sheets and tire side rubber sheets are divided tightly, the end point bubbles are difficult to completely exhaust in the rolling process of the forming process, and the end points are easy to trap air;

3. and during the vulcanization, mold closing and shaping processes of the molded tire blank, the tire side area is finally contacted with the side plate of the mold along with the rise of the shaping pressure, and in the process, bubbles in the tire blank are continuously collected to the tire side from the shoulder area and the seam allowance area.

Under the common influence of the factors, when the tire blank is vulcanized, air bubbles gather at the tire side, the tire cord rubber coating is easily broken, so that tire steel wires are oxidized and blued, even the tire side rubber outside the tire cord is broken, and a tire side rotten hole visible to naked eyes is generated. In addition, under the effect of embryo vulcanization shaping pressure, bubbles can be transferred along with fine gaps in the carcass steel cords or the marking yarns, and finally appearance holes, which are symmetrical with respect to an upper mold and a lower mold, fixed in radial positions and obviously exposed from the steel cords, appear in the finished tire.

Aiming at the phenomenon of the tire side cavity of the finished tire, the current countermeasure measures are limited, and the method mainly focuses on reducing the accumulation amount of bubbles, artificially pretreating the bubbles of the tire blank, increasing the path and the effect of bubble discharge and the like. Such as optimizing the end point branching of the components in the tire side area, increasing the exhaust lines of the tire side components, controlling the end point thickness of the extrusion components, puncturing the puncture hole of the puncture cone of the tire blank, branching the exhaust hole position of the side plate of the mold, selecting the type of the vulcanizing capsule, vulcanizing and shaping the pressure and the like. Tests prove that the traditional method has no remarkable improvement effect on all-steel radial tires 19.5-inch low-flatness series products.

Disclosure of Invention

The invention aims to provide an all-steel radial tire for improving the elongation of a tire cord, which adjusts the width of a tire body forming plane by limiting the elongation range of the tire cord so as to solve the problems in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme:

an all-steel radial tire for improving the elongation of a carcass cord, which comprises an embryo assembled and formed in a forming drum, wherein the embryo comprises a steel cord, the length of the carcass cord between the inner end points of upper and lower die steel rings of the embryo is 2ab, the length of the carcass cord between the inner end points of the upper and lower die steel rings of the forming drum is 2a 'b', and the calculation formula of the elongation of the carcass cord of the embryo is as follows: when t is (2ab-2a 'b')/2 a 'b' x 100%, and the tire specification is 285/70R19.5, the elongation of the embryo carcass cord of the tire is in the range of: t is more than or equal to 1.74 percent and less than or equal to 2.48 percent, and when the tire specification is 265/70R19.5, the elongation rate of the embryo carcass cord of the tire is in the range of: t is more than or equal to 1.02 percent and less than or equal to 1.81 percent, and when the tire specification is 245/70R19.5, the elongation rate of the embryo carcass cord of the tire is in the range of: t is more than or equal to 1.06 percent and less than or equal to 2.76 percent, and when the tire specification is 225/70R19.5, the elongation rate of the embryo carcass cord of the tire is in the range of: t is more than or equal to 1.15 percent and less than or equal to 2.08 percent.

As a further scheme of the invention: when the specification of the tire is 285/70R19.5, the plane width of the tire blank is as follows: 574 and 582 mm.

As a further scheme of the invention: when the specification of the tire is 265/70R19.5, the plane width of the tire blank is as follows: 540 and 548 mm.

As a further scheme of the invention: when the tire specification is 245/70R19.5, the plane width range of the tire embryo is as follows: 500-.

As a further scheme of the invention: when the tire specification is 225/70R19.5, the plane width range of the tire embryo is as follows: 452 and 460 mm.

Compared with the prior art, the invention has the beneficial effects that: the tire blank has a novel structure, and compared with the prior art, the tire blank has the advantages that the tire blank forming plane width is correspondingly adjusted, the length of the tire cord in the tire is increased, the drawing amount and time of the tire cord are reduced, the defects of cord bending, uneven tire lining and the like of a finished tire are avoided, the side part of the tire blank is quickly and tightly matched with a side plate of a mold in the vulcanization forming process, the vulcanization capsule is extruded under the shaping pressure action of the capsule on the tire, the concentrated space of bubbles is eliminated, the bubbles at the side part of the tire are uniformly dispersed, the waste and defective rate of the rotten holes at the side wall in the tire manufacturing process is reduced, and the product performance and the service life are improved.

Drawings

FIG. 1 is a schematic cross-sectional view of a tire carcass structure;

FIG. 2 is a schematic diagram of a cross-sectional structure of an embryo during a prior art vulcanization process;

FIG. 3 is a schematic diagram of a cross-sectional structure of an embryo during an improved post-vulcanization process;

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the embodiment of the invention, the all-steel radial tire for improving the elongation rate of the tire body cord thread comprises the tire body steel cord thread, the length of the tire body cord thread between the inner end points of an upper mold steel ring and a lower mold steel ring of a finished tire is 2ab, the length of the tire body cord thread between the inner end points of the upper mold steel ring and the lower mold steel ring of a molding procedure laminating drum is 2a 'b', wherein 2a 'b' belongs to structural design parameters, the tire body cord thread elongation rate can be obtained by calculating the design molding plane width and the steel ring width of a specific product, the steel ring width of the specific product is a fixed value, and the calculation formula of the elongation rate of the tire body cord: t is (2ab-2a 'b')/2 a 'b' x 100%, the limited range of the elongation of the embryo carcass cord is related to the specification model of the tire, the specification model of the tire is different, and the limited range of the elongation of the embryo carcass cord is also different.

The tire specifications are different, the limit ranges of the elongation rates of the embryo carcass cords of the corresponding tires are different, and when the tire specifications are 285/70R19.5, the ranges of the elongation rates of the embryo carcass cords of the tires are as follows: t is more than or equal to 1.74 percent and less than or equal to 2.48 percent, and when the tire specification is 265/70R19.5, the elongation rate of the embryo carcass cord of the tire is in the range of: t is more than or equal to 1.02 percent and less than or equal to 1.81 percent, and when the tire specification is 245/70R19.5, the elongation rate of the embryo carcass cord of the tire is in the range of: t is more than or equal to 1.06 percent and less than or equal to 2.76 percent, and when the tire specification is 225/70R19.5, the elongation rate of the embryo carcass cord of the tire is in the range of: t is more than or equal to 1.15 percent and less than or equal to 2.08 percent, and the change of the elongation rate of the carcass cord is closely related to the adjustment size of the width of the shaping plane of the carcass.

The corresponding relation between the plane width and the carcass cord elongation is as follows:

t＝(2ab-2a＇b＇)/2a＇b＇×100％

(2ab- (plane width-2 × steel ring width × 0.91) ]/(plane width-2 × steel ring width × 0.91) × 100%

Note: the steel ring is a semi-finished part, and the width of the steel ring of a specific product is a fixed value and is a known item.

The principle of adjusting the elongation of the tire body cord to improve the rejection rate of the sidewall rotten holes in the invention is as follows: because the tire is under the action of shaping pressure in the forming and vulcanizing processes, the action of expanding and inward pulling of the tire body cord thread is inevitably generated, and in order to eliminate the influence of expanding and inward pulling of the cord thread in the design, the pre-stretching rate of the cord thread is designed, so that the defects of bending of the cord thread, uneven tire liner and the like of a finished tire are avoided. In the tire vulcanization process, the design of the pre-stretching rate of the tire body is larger, the stretching time of the cord thread is prolonged, as shown in figure 3, the side part of the tire body is finally contacted with a side plate of a mold during vulcanization, the time for tightly attaching the side part of the tire body to the mold is later than that of the shoulder part and the seam part, the air bubbles in the shoulder part and the seam part are continuously converged towards the side part, the air bubbles press the tire side glue and the cord thread to cover the glue, and finally a tire side rotten hole with a visible appearance is formed.

The actual length of the carcass steel wire has no substantial change in the production process, and the stretching of the carcass cord refers to the degree of the carcass cord being drawn into the tire under the action of the molding and vulcanization shaping pressure. The invention increases the length of the carcass cord in the embryo by adjusting the setting of the width of the molding plane, compared with the tire in the prior art, the tire reduces the stretching rate of the carcass cord after the tire is molded and vulcanized, reduces the twitching amount and time of the carcass cord, can ensure that the side part of the embryo is rapidly and closely matched with the side plate of the mold in the vulcanization molding process, on one hand, the gathering time and the gathering amount of the embryo bubbles from the shoulder part and the seam area to the side part of the embryo in the vulcanization molding process are limited, on the other hand, after the side part of the embryo is rapidly and closely contacted with the side plate of the mold, the gathering space of the bubbles is eliminated to a certain extent through the action of qualitative pressure and the extrusion of a vulcanization capsule, the bubbles at the side part of the embryo are uniformly dispersed, the possibility of gathering the bubbles at the.

In order to verify the accuracy of the theoretical derivation result and verify the specificity of the embryo when the value of the elongation rate of the carcass cord is within the range under the premise of different tire specifications, the following verification experiments are carried out:

after the experiment, when the finished section is bad, under the condition of ensuring that the rate of the waste products of the rotten holes in the side wall is low, the size or the positioning of the semi-finished part can be adjusted to improve the bad section, so that under the condition that the section is bad but the rate of the waste products of the rotten holes in the side wall is low, the bad section is improved through other means, and the improved tire can ensure that the section is good and the rate of the waste products of the rotten holes in the side wall is low.

The results of the above overall experiments can yield: the elongation of the tire body cord is an important influence factor of the tire side hole in the prior art, and the rejection rate of the tire side hole is obviously reduced along with the reduction of the elongation.

The results of the above experiments were analyzed as follows:

1. when the tyre specification is 285/70R19.5, it can be concluded from the experimental data of examples 1 to 3 in comparison with the prior art: when the elongation of the tire body cord is 1.74-2.48%, compared with the prior art of the elongation of the cord under the tire specification, the method can obviously reduce the rejection rate of the rotten holes on the tire side, and meanwhile, in the range, the rejection rate of the rotten holes on the tire side is gradually reduced along with the gradual reduction of the elongation of the cord; from a comparison of the experimental data of examples 1 to 3 with comparative examples 1 and 2, it can be concluded that: when the elongation of the carcass cord is lower than 1.74% or higher than 2.48%, the experimental effect of the elongation of the carcass cord can cause the increase of the rate of the rotten holes of the embryo or the bending of the shoulder cord of the finished product, so that the particularity that the elongation of the carcass cord is in the range of 1.74% -2.48% in the tire with the specification of 285/70R19.5 in the invention can be reversely verified, wherein in the example 1, the rate of the rotten holes of the sidewall is reduced compared with the prior art, but the actual requirement of the tire on the rate of the rotten holes of the sidewall in the prior art can not be met, so that the range of the elongation of the carcass cord is limited to 1.74% -2.48% under the specification of the tire.

2. When the tyre specification is 265/70R19.5, it can be concluded from the experimental data of examples 1 to 3 in comparison with the prior art: when the elongation of the tire cord is 1.02% -1.81%, compared with the prior art of the elongation of the cord under the tire specification, the method can obviously reduce the rejection rate of the rotten holes on the tire side, and meanwhile, in the range, the rejection rate of the rotten holes on the tire side is gradually reduced along with the gradual reduction of the elongation of the cord; from a comparison of the experimental data of examples 1 to 3 with comparative examples 1 and 2, it can be concluded that: when the elongation of the carcass cord is lower than 1.02% or higher than 1.81%, the test effect of the method can cause the embryo rotten hole rejection rate to be higher than that of the prior art, so that the particularity that the elongation of the carcass cord is in the range of 1.02% -1.81% in the tire with the specification of 265/70R19.5 in the invention can be verified reversely. In example 1, the sidewall rotten hole rate is reduced compared with the prior art, but the actual requirement of the tire on the sidewall rotten hole rate in the prior art still cannot be met, so that under the tire specification, the range of the carcass cord elongation is defined as: 1.02% -1.81%.

3. When the tyre specification is 245/70R19.5, it can be concluded from the experimental data of examples 1 to 3 in comparison with the prior art: when the elongation of the tire cord is 1.06% -2.76%, compared with the prior art of the elongation of the cord under the tire specification, the method can obviously reduce the rejection rate of the rotten holes on the tire side, and meanwhile, in the range, the rejection rate of the rotten holes on the tire side is gradually reduced along with the gradual reduction of the elongation of the cord; from a comparison of the experimental data of examples 1 to 3 with comparative examples 1 and 2, it can be concluded that: when the elongation of the carcass cord is lower than 1.06% or higher than 2.76%, the test effect of the method can cause the embryo rotten hole rejection rate to be higher than that of the prior art, so that the particularity that the elongation of the carcass cord is in the range of 1.06% -2.76% in the tire with the specification of 245/70R19.5 in the invention can be verified reversely.

4. When the tyre specification is 225/70R19.5, it can be concluded from the experimental data of examples 1 to 3 in comparison with the prior art: when the elongation of the tire cord is 1.15% -2.08%, compared with the prior art of the elongation of the cord under the tire specification, the method can obviously reduce the rejection rate of the rotten holes on the tire side, and meanwhile, in the range, the rejection rate of the rotten holes on the tire side is gradually reduced along with the gradual reduction of the elongation of the cord; from a comparison of the experimental data of examples 1 to 3 with comparative examples 1 and 2, it can be concluded that: when the elongation of the carcass cord is lower than 1.15% or higher than 2.08%, the experimental effect of the method can cause the embryo rotten hole rejection rate to be higher than that of the prior art, so that the particularity that the elongation of the carcass cord is in the range of 1.15% -2.08% in the tire with the specification of 225/70R19.5 in the invention can be verified reversely. In example 1, the sidewall rotten hole rate is reduced compared with the prior art, but the actual requirement of the tire on the sidewall rotten hole rate in the prior art still cannot be met, so that under the tire specification, the range of the carcass cord elongation is defined as: 1.15 to 2.08 percent.

The molding plane width is sequentially increased step by adjusting panel parameters of molding equipment, and along with the increase of the plane width, the distance between steel ring composite pieces is increased, namely the length of the tire body cord between steel rings is gradually increased, and the elongation of the tire body cord is sequentially reduced. But the elongation of the tire body cord line inevitably exists, when the elongation is reduced without limit and is smaller than a limit value, the defects of bending, uneven tire liner and the like of the tire shoulder part cord line of a finished product are caused, and according to manufacturing process conditions and product development experience, the elongation t of the all-steel tire body cord line is more than or equal to 1.2 percent except special specifications.

The invention has novel structure and stable operation, when in use, the invention limits the elongation rate range of the tire body cord, correspondingly adjusts the molding plane width of the tire body, increases the length of the tire body cord in the tire body, reduces the drawing amount and time of the tire body cord, avoids the defects of cord line bending, uneven tire lining and the like of a finished tire, ensures that the side part of the tire body is quickly and tightly matched with a side plate of a mold in the vulcanization molding process, forms the extrusion to a vulcanization capsule through the molding pressure action of the capsule on the tire body, eliminates the concentrated space of bubbles, ensures that the bubbles at the side part of the tire body are uniformly dispersed, reduces the waste and defective rate of the side cavity in the tire manufacturing process, and simultaneously improves the product performance and the service life.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.