RU2729897C9 - Pneumatic radial light truck - Google Patents

Abstract

FIELD: automotive industry.

SUBSTANCE: invention relates to pneumatic passenger and light truck tires of radial design, the maximum load of which does not exceed 975 kg, and the maximum permissible speed is not more than 210 km/h, the rubberized frame fabric of which consists of one or two layers of rubberized textile cord. Tire consists of tread, rubberized breaker bracelet, beads, sidewalls, rubberized carcass fabric made of one or two layers of rubberized cord, 1100 dtex structure. The cord layers are made with thickness of 0.5÷0.6 mm, tensile strength of cord thread of not less than 157 N, number of torsions of base warp of first and second twist 350÷390 turns per 1 m, with number of tuft weft twitches of not less than 350 rpm per 1 m, with thread frequency on warp of 120÷130 threads per 100 mm and by weft 7÷12 threads per 100 mm, with rubberized cord thickness in carcass 0.8÷1.0 mm, using frame rubber, providing strength of connection of cord thread with frame rubber of not less than 110 N/10 mm, using an impregnating composition based on vinylpyridine latex, wherein in the finished tire, the pitch of the threads in the rubber-coated carcass cloth in the bead area is 0.75–0.85, and in the area of track 1.0–1.6.

EFFECT: higher overall performance of the pneumatic tire, reduced coefficient of rolling resistance, as well as increased elasticity of carcass web and circumferential rigidity of the tire.

Description

The invention relates to pneumatic passenger and light truck tires of radial design, the maximum load of which does not exceed 975 kg, and the maximum allowable speed is not more than 210 km/h, the rubberized carcass fabric of which consists of one or two layers of rubberized textile cord.

Known technical solutions for pneumatic passenger tires with one or two layers of rubberized textile cord in the carcass: patent No. 2496655 "Pneumatic tire tire", publ. October 27, 2013, patent No. 118584 "Pneumatic tire cover", date of publication. 07/27/2012, RF patent No. 2262453 “Radial design pneumatic tire tire”, publ. date 10.20.2005, RF patent 2467883 “Pneumatic tire”, pub. 11/27/2012.

The closest analogue to the developed solution is the technical solution according to patent No. 2496655 "Pneumatic tire tire", including a carcass made of at least one layer of rubberized textile cord, characterized in that the textile cord is made of polyester textile material of structure 110, 144 , 167, 220 tex with a thread specific strength of 67-72 cN / tex, a thread diameter of 0.48-0.65 mm with a thread breaking strength of 155-300 N / thread, a thread frequency of at least 90 and not more than 180 pieces per length 100 mm.

The disadvantage of these solutions is insufficient tire performance, rolling resistance coefficient, as well as low tire resistance to side slip.

The objective of this invention is to develop a pneumatic radial car and light truck tire with increased overall performance, providing a reduction in hysteresis losses in carcass materials, which leads to a decrease in the rolling resistance coefficient, as well as an increase in the elasticity of the rubberized carcass fabric and circumferential rigidity of the tire, as a result of increasing tire resistance to sidewall withdrawal, expansion of the arsenal of technical means.

To achieve this task, a design has been developed for a pneumatic passenger and light truck tire, consisting of a tread (1), a rubberized breaker bracelet consisting of one or two textile layers (6) and two layers of rubberized metal cord (7), sidewalls (4), bead rings (5), rubberized frame fabric, made of one or two layers of rubberized polyester textile cord (2,3) of 1100 dtex structure, with a cord layer thickness of 0.5÷0.6 mm, breaking strength of the cord thread of at least 157 N, number twists of the warp threads of the first and second twists 350÷390 revolutions per 1 m, with the number of twists of the weft thread at least 350 revolutions per 1 m, with a frequency of threads in the warp 120÷130 threads per 100 mm and in the weft 7÷9 threads per 100 mm , with a rubberized carcass fabric thickness of 0.8 mm ÷ 1.0 mm, with the use of carcass rubbers, ensuring the bond strength of the cord thread with the carcass rubber of at least 110 N/10 mm, with the use of an impregnating composition based on vinylpyridine latex, at the same time, in the finished tire, the thread pitch in the rubberized carcass fabric in the bead area is 0.75-0.85, and in the tread area 1.0-1.6.

The rubberized frame fabric, being the main power part of the tire, limits the internal volume of the tire and perceives the loads acting on the tire, it must have considerable strength, as well as a certain elasticity. The canvas consists of one or more layers of rubberized cord and rubber layers superimposed on each other. The strength of the tire is determined by the strength of the rubberized frame fabric and mainly depends on the strength of the cord, since its modulus of elasticity is several orders of magnitude greater than the modulus of elasticity of rubber. The shape of the carcass and the number of cord layers in it are determined by calculation based on the specified air pressure, load, type and purpose of the tire. The carcass fabric bears the main load during the operation of the tire, providing the latter with strength, elasticity, wear resistance and preservation of a given shape. The frame fabric in the tire works mainly in tension and repeated bending. These stresses arise, as a rule, as a result of air pressure and the action of centrifugal forces, which create tensile stresses in the cord. The thickness of the cord, its density, heat resistance and other physical and mechanical properties have a significant impact on the operation of the carcass.

In the developed technical solution in the layers of cord of the finished tire, the number of threads per 100 mm is 120-130 for the warp and 7-12 for the weft, which makes it possible to fill the gaps between the threads and make the fabric denser in the light, at the same time, according to the technical requirements for the final product (fabric) weft must have strength that is not inferior to the warp. In this case, the weft threads must also have a high twist in order to achieve the required strength properties.

The need to twist the threads is dictated by the requirements to achieve a given breaking strength, allowable elongations both at break and under working loads, plus the need to guarantee a stable bond with the carcass rubber. In addition, twisting the threads into a cord thread makes it possible to achieve the required durability under dynamic loads.

The use of polyester cord of the structure 1100 dtex, with the number of twists of the warp threads of the first and second twists 350÷390 revolutions per 1 m, with a frequency of threads in the warp 120÷130 threads per 10 cm and in the weft 7÷12 threads per 10 cm, with a rubberized thickness cord in the carcass 0.8 mm ÷ 1.0 mm, and in the finished tire the pitch of the threads of the rubberized carcass fabric in the bead area is 0.75-0.85, and in the treadmill area 1.0-1.6, providing the necessary and sufficient margin of safety of the tire carcass, its rigidity and performance, tire durability.

Each carcass cord is isolated from its neighbors and at the same time connected to them by a unique rubber compound. Rubber protects cord threads from moisture, chafing and promotes even distribution of loads between them. The presence of rubber between the layers of cord threads increases the weight of the tire, and therefore affects its performance. Calculated (finite element method) and empirically in the present invention, the thickness of the rubberized cord and rubber layers was selected to comply with the optimal characteristics of the tires according to the present invention. The thickness of the rubberized cord layer is from 0.8 mm to 1.0 mm.

Rubber compounds used for rubberizing polyester textile cord, in turn, must have high endurance under repeated deformations and low hysteresis losses, have high resistance to thermal aging, as well as high bond strength with the carcass cord and high bond strength with adjacent layers of the sidewall and bead tape .

The rubber in the layer of the carcass fabric operates in a mode close to the mode of a given deformation. The amount of rubber deformation is determined by the loading of the side wall (radial deflection) and the relative rubber content in the layer (cord frequency). A feature of loading rubber in a layer of radial tires is that when the tire is rotated by 10 °, the direction of the main deformations changes. In this case, the rubber in the frame web layer experiences biaxial tension, and the rubber shear in the layer is about 40%.

In the present invention, in order to achieve a technical result, a rubber compound based on polyisoprene natural, carbon black filler, and a modifying system, which is introduced to achieve a high level of bond strength in the rubber compound, is used.

The widespread use of reinforcing materials based on synthetic fibers almost always requires their treatment with various adhesives (impregnating compositions). After rubberizing, a three-component system cord thread - adhesive - rubber is formed, which has two interfacial surfaces. The strength of the cord-adhesive-rubber bond is affected by: the chemical structure and surface structure of the fiber, the composition and properties of the adhesive used, and the formulation of the rubber mixture. Because the chemical structures of synthetic fibers used to make tire cords and rubber are very different, these materials are structurally incompatible in terms of chemical and physical properties. Synthetic fibers have high strength and low elongation, while rubbers, on the contrary, are polymeric materials with high elongation and low strength. The polar groups (amide, hydroxyl and carbonyl groups) present in the structure of synthetic fibers are incompatible with the non-polar structures contained in rubber. To solve this problem in practice, in most cases, latex impregnating compositions are used, which are vinylpyridine (VP) latex and / or styrene-butadiene (SB) latex, at least one latex selected from a group consisting of vinylpyridine-styrene-butadiene latex, vinylpyridine-styrene-butadiene latex modified with carboxylic acid, styrene-butadiene latex and styrene-butadiene latex modified with carboxylic acid. In the present invention, an impregnating composition based on vinyl pyridine latex is used.

The design parameters of the carcass layers and rubber layers of the tire, the characteristics of the applied textile polyester cord, in combination with the use of unique carcass rubbers, as well as an impregnating composition based on vinylpyridine latex, make it possible to achieve high strength characteristics, adhesive properties of the carcass layers in light radial tires, as in connection with textile cord with a rubber compound for rubberizing the carcass, and with adjacent rubber compounds of the sidewall and side tape.

To achieve a technical result, an experimental rubber compound has been developed with low hysteresis losses, with the following strength indicators (values are given in table 1), in comparison with a commercially used rubber compound.

According to the first version of the developed solution, tires 175 / 70R13 were manufactured with a rubberized carcass fabric made of one layer of rubberized polyester textile cord grade 16PDU with a structure of 1100 dtex, with a cord layer thickness of 0.53 ± 0.03 mm, a breaking strength of the cord thread of at least 157 H, the number of twists of the warp threads of the first and second twists is 370 revolutions per 1 m, with a thread frequency of 125 threads per 100 mm for the warp and 8 threads per 100 mm for the weft, with a thickness of a rubberized frame fabric of 0.83 ± 0.03 mm, s the use of carcass rubbers that ensure the bonding strength of the cord thread with the carcass rubber of at least 110 N/10 mm, with the use of an impregnating composition based on vinylpyridine latex, while in the finished tires the pitch of the threads in the rubberized carcass fabric in the bead area is 0.8 ± 0, 01, and in the area of the treadmill 1.23±0.01.

According to the second version of the developed solution, tires 195/65R15 were manufactured with a rubberized carcass fabric made of one layer of rubberized polyester textile cord grade 16PDU with a structure of 1100 dtex, with a cord layer thickness of 0.53 ± 0.03 mm, and a breaking strength of the cord thread of at least 157 H, the number of twists of the warp threads of the first and second twists is 370 revolutions per 1 m, with a thread frequency of 125 threads per 100 mm for the warp and 8 threads per 100 mm for the weft, with a thickness of a rubberized frame fabric of 0.93 ± 0.03 mm, s the use of carcass rubbers that ensure the bonding strength of the cord thread with the carcass rubber of at least 110 N/10 mm, with the use of an impregnating composition based on vinylpyridine latex, while in the finished tires the pitch of the threads in the rubberized carcass fabric in the bead area is 0.8 ± 0, 01, and in the area of the treadmill 1.26±0.01.

Based on the test results, the developed tires comply with the requirements of UN Regulations No. 30, No. 117 and, in comparison with the prototype (using a 1100 dtex polyester textile material in the carcass and commercially used rubber compounds), provide an increase in the overall performance of a pneumatic tire up to 7%, a decrease in hysteresis losses in carcass materials, which leads to a decrease in the rolling resistance coefficient up to 6%, as well as an increase in the elasticity of the carcass canvas and the circumferential rigidity of the tire, which affect the improvement of the tire side slip resistance, achieving the claimed technical result with all the claimed set of essential features of this invention.

The calculated and claimed technical result is also achieved with the thicknesses of the carcass cord layers of 0.5 ÷ 0.6 mm, the number of twists of the warp threads of the first and second twists of 350 ÷ 390 revolutions per 1 m, the frequency of the warp threads of 120 ÷ 130 threads per 100 mm and weft 7 ÷ 12 threads per 100 mm, with a rubberized cord thickness in the carcass 0.8 mm ÷ 1.0 mm, thread pitch in the rubberized carcass fabric in the bead area 0.75-0.85, and in the treadmill area 1, 0-1.6 in conjunction with other essential features of the invention.

The developed solution can be implemented on standard equipment using standard technology.

Claims (1)

Pneumatic car and light truck tire of radial design, consisting of a tread, a rubberized belt strap, beads, sidewalls, a rubberized carcass fabric made of one or two layers of rubberized cord, 1100 dtex structure, characterized by the use of cord layers with a thickness of 0.5÷0.6 mm , the breaking strength of the cord thread is not less than 157 N, the number of twists of the warp thread of the first and second twist is 350 ÷ 390 revolutions per 1 m, with the number of twists of the weft thread is at least 350 revolutions per 1 m, with a frequency of threads on the warp of 120 ÷ 130 threads per 100 mm and weft 7 ÷ 12 threads per 100 mm, with a rubberized cord thickness in the carcass 0.8 mm ÷ 1.0 mm, using carcass rubbers that ensure the bond strength of the cord thread with carcass rubber of at least 110 N/10 mm, with using an impregnating composition based on vinylpyridine latex, while in the finished tire the pitch of the threads in the rubberized frame fabric in the bead area is 0.75-0.85, and in the tread area 1.0-1.6.

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