Pneumatic tire for heavy vehicles

FIELD: transportation.

SUBSTANCE: invention is attributed to pneumatic tire for which factor of H/S type has value exceeding 0.55 and which has radial reinforcement of frame and contains flange reinforcement formed by at least two flange working layers created of inextensible reinforcing elements intercrossing from one layer to another forming with circumferential direction the angles in the range of 10 to 45°. Tyre tread connected with two beads by means of two sidewalls is located over this radial frame reinforcement in radial direction. Crest reinforcement contains at least one layer of circumferential reinforcing elements. Value of ratio of crest block width at the end of shoulder area to crest block width at center circumferential plane is less than 1.20, and value of ratio of axial width of at least one layer of circumferential reinforcing elements to axial width of tire tread exceeds 0.5 and preferably exceeds 0.6.

EFFECT: tire strength and reliability is improving.

23 cl, 5 dwg

 

The present invention relates to a pneumatic tire for which the coefficient of the form H/S has a value strictly greater than 0.55 and having radial reinforcement frame and, more specifically, to a pneumatic tire designed to equip vehicles carrying heavy loads and moving at a relatively high velocity, such as trucks, tractors, trailers or buses.

Reinforcement reinforcement or reinforcing the carcass of a pneumatic tire, in particular a pneumatic tire for heavy vehicles type "poids-lourds", at the present time is likely to be a package consisting of one or more layers of reinforcing elements, usually called "layers frame", "layers crest and tpicos way of describing various types of reinforcement reinforcement follows from the method of manufacture, consisting in the implementation of a series of semi-finished products in the form of plies, provided with a threadlike and often longitudinal reinforcing elements, which are connected or stacked on one another in order to form the workpiece pneumatic tyres. These layers are flat, have a considerable size and then Viravaidya and cut in function of the actual size of this product. At the first stage of Assembly, the connection layers also implemented aetsa, essentially, in a flat condition. Then implemented in this way, the workpiece is subjected to molding to give the usual pneumatic tire toroidal profile. Then the so-called "finishing" semi-finished product are superimposed on the preparation for getting products ready for vulcanization.

This method of "classic" type implies, in particular, for the manufacture of wood pneumatic tires, the use of the fastening element (usually onboard rings), used to fasten or hold the valve frame in the area of the sides of this pneumatic tyres. Therefore, for a method of this type provide the turnover area of all layers, forming a reinforcement frame (or only parts of these layers) around the side of the ring, which is located in the Board of pneumatic tires. Thus create a certain type of fastening of the reinforcement frame in the Board.

Generalization in the industry of the classical method of this type, despite numerous variations in how the implementation of these layers and their connections, leading specialist in the art to use vocabulary specific to this method; hence the commonly used terminology, containing, in particular, the terms "layer", "carcass", "bead ring", "molding" to indicate the transition from the plane of the pros is I to the profile of the toroidal shape, etc.

Currently, there are pneumatic tires that do not contain "layers" or "bead rings ' as such in accordance with the above definitions. For example, in patent EP 0582196 described pneumatic tire, made without the use of semifinished products in the form of layers. For example, the reinforcing elements of different reinforcing structures are superimposed directly on the adjacent layers of rubber mixes, successive layers on the toroidal core, the shape of which makes it possible directly to obtain the profile representing target profile pneumatic tyres in the process of its production. Thus, in this case no longer use the term "prefabricated", "layers" or "bead ring". Basic products, such as rubber mixtures and reinforcing elements in the form of filaments or fibers, directly applied onto the core. And since the core has a toroidal shape, it is no longer necessary to mould the workpiece in order to move from a flat profile to the profile of the toroidal shape.

At the same time, in the pneumatic tire described in this patent is not a "traditional" turnover layer frame around the side of the ring. In this case, this type of fastening is replaced by a construction in which have Primak is accordingly referred to underpin the design of the circumferential sidewall cord thread, all this structure is filled in the rubber compound fastening or connection.

There are also ways to build on the toroidal core, which are semi-finished product, specifically designed for easy, fast and effective styling on the Central core. And finally, you can also use a hybrid containing both some products in the form of semi-finished products intended for the implementation of some structural elements (such as layers, side rings and so on), while the other structural elements are implemented based on the direct imposition of the core rubber mixtures and/or reinforcing elements.

In this document, in order to take into account the latest technological achievements in the field of manufacturing and in the field of product design, classical terms such as "layers"toe rings", etc. are replaced by neutral terms or terms that do not depend on the type of manufacturing method. Thus, the term "supporting the design of the frame or supporting structure sidewall suitable for designation of the reinforcing elements of the layer frame in the classical method of manufacture and the respective reinforcing elements, usually applied at the level of the sidewalls, for pneumatic tyres, manufactured in the accordance with the method without using semi-finished products. The term "area secure", in turn, can mean both "traditional" turnover layer frame around the side of the ring in accordance with the classical method of manufacture, and the system formed by the supporting elements, the rubber mixture and the adjacent parts of the reinforcing structure of the sidewall in the lower zone and implemented in accordance with the method with the direct imposition of these elements on the toroidal core.

In the General case, in the pneumatic tire of the type "poids-lourds" clamp frame fixed on either sides in the bead area and on top of it in the radial direction is located the valve crest formed of at least two layers stacked on one another and formed of cord yarns or ropes parallel to each other in each layer. This valve crest may also contain a layer of metal cord wires or cables with low elongation, forming with the circumferential direction an angle, the value of which lies in the range from 45° to 90°and this layer is called triangulation layer is located between the valve frame and the first so-called working layer of the ridge in the radial direction are formed parallel cord, wire or cable, at an angle not exceeding 45° in absolute value. This t is angulations layer forms, at least with the said working layer triangulated reinforcement that has a small deformations under the influence of various stresses acting on it, the main function of this triangulation layer is to be perceived effort transverse compression, which are the main object of the reinforcing elements in the area of the crest of pneumatic tires.

The armature of the crest contains at least one functional layer; in the case where the above-mentioned valves ridge contains at least two working layers, these layers are formed of inextensible metal reinforcing elements parallel to each other in each layer and crossed from one layer to the next, forming with the circumferential direction angles having a magnitude in the range of 10° to 45°. Mentioned layers, forming a working valve, can be covered by at least one so-called protective layer, preferably formed of metal and tensile or so-called elastic reinforcing elements.

In the case of pneumatic tires, designed for heavy-duty vehicles type "Poids-Lourds", usually there is only one protective layer and its protective reinforcing elements are in most cases intended the s in the same direction and at the same angle in absolute value, as reinforcing elements of the working layer, the most outside in the radial direction and, therefore, adjacent to this protective layer. In the case of pneumatic tires used for heavy wheeled equipment road construction equipment and intended for rolling on rough surfaces, it is preferable to have two protective layers, and the reinforcing elements of the two protective layers are crossed from one layer to another and reinforcing members on the inside in the radial direction of the layer overlap with inextensible reinforcing elements of the outside in the radial direction of the working layer of the ridge, adjacent to the mentioned interior in the radial direction of the protective layer.

Cord yarns or ropes are inextensible in the case when these cord yarns or ropes get under the action of tensile forces having a magnitude of 10% from the efforts of rupture, elongation not exceeding 0,2%.

Cord thread or cables are elastic in that case, when these cord yarns or ropes get under the action of tensile stress, is the stress rupture, elongation at least equal to 4%.

Circumferential direction of the pneumatic tire, or its longitudinal direction is a direction which begins on the peripheral part of this pneumatic tire and defined by the direction of rolling this pneumatic tyres.

The transverse or axial direction of the pneumatic tire is parallel to the axis of rotation of this pneumatic tyres.

Radial direction of the pneumatic tire is a direction crossing the axis of rotation of this pneumatic tire and perpendicular to this axis.

The axis of rotation of the pneumatic tire represents the axis around which the pneumatic tire is rotating during normal operation.

Radial or meridional plane of the pneumatic tire is a plane that contains the axis of rotation of the pneumatic tire.

The average circumferential plane, or Equatorial plane of the pneumatic tire is a plane perpendicular to the axis of rotation of the pneumatic tire and share this pneumatic tire into two equal parts.

Some modern so-called "road" pneumatic tires, for which the coefficient of the form H/S has a value in excess of 0.55, are supposed to move with great speed and at all distances due to the expansion and improvement of the road network around the world. The totality of the circumstances in which operates a pneumatic tyre, which can significantly improve the number of kilometers, and the wear of the pneumatic tires is reduced. At the same time the mouth of Losta strength pneumatic tires and, in particular, its reinforcement of the ridge is reduced.

Actually there are mechanical stresses on the level of reinforcement of the ridge and, more specifically, the shear stress between the layers of the crest associated with a marked temperature increase operation on the level of the ends of the shortest in the axial direction of the layer of the ridge that result in the emergence and spread of cracks in the rubber in the end regions. The same problem exists in the case of the edges of two layers of reinforcing elements, and mentioned other layer is not necessarily directly adjacent to the first mentioned layer in the radial direction.

In order to increase the durability and service life of the valve crest pneumatic tires of this type have already been proposed various technical solutions related to the structure and quality of the layers of reinforcing elements and/or profiled elements made of rubber mixtures, which are located between and/or around the ends of the layers of reinforcing elements and, more specifically, the ends of the layer, the shortest in the axial direction.

In the patent FR 1389428 to increase resistance to damage rubber mixtures, which are located in the immediate vicinity of the edges of the reinforcement ridge, it is recommended to use in combination with a treadmill tread about adusei small hysteresis, rubber profiled element, covering at least the sides and edge areas of the valve of the ridge and formed of a rubber mixture with a small hysteresis.

In the patent FR 2222232 to resolve the separation between the reinforcement layers of the crest is recommended to cover the ends of the armature buffer rubber layer, for which the shore hardness And differs from the shore hardness And of the tread located over the said valve crest, and higher than the shore hardness And made of profiled rubber compound element, located between the edges of the reinforcement layers of the ridge and the valve frame.

In the patent FR 2728510 it is suggested to place, on the one hand, between the valve frame and a working layer of reinforcement ridge, the closest in the radial direction to the axis of rotation of the pneumatic tire, continuous in the axial direction of the layer formed of inextensible metal cord of wires, forming with the circumferential direction an angle which at least 60°and a width in the axial direction at least equal to the width in the axial direction of the shortest working layer of the ridge, and on the other hand, be placed between the two working layers of crest extra layer formed metal reinforcing elements oriented, essentially, parallel to the regional trend.

Continuous movement in particularly difficult conditions designed pneumatic tire has revealed the limits of resistance and service life of these pneumatic tire.

In order to resolve the above-mentioned disadvantages and to improve the durability and service life of the valve crest of a pneumatic tire, in the French patent WO 99/24269 proposed on either side of the Equatorial plane and in the immediate axial continuation of the additional layer of reinforcing elements that are essentially parallel district direction, to connect, at some distance in the axial direction of the two working layers of the ridge formed by the reinforcing elements, crossed from one layer to another, with the possibility then the separation of these layers using made of profiled rubber compound elements, at least the remaining part of the total width of the two mentioned working layer.

The technical problem of this invention is to develop a pneumatic tire for heavy vehicles type "Poids-Lourds", for which the coefficient of the form H/S has a value strictly greater than 0.55 and possessing improved characteristics of resistance and service life compared to commonly used pneumatic Shi is AMI.

This technical problem is solved in accordance with the invention by means of a pneumatic tire for which the value of the coefficient of the form H/S has a value strictly greater than 0.55 and having radial reinforcement frame and containing a reinforcement ridge, formed from at least two working layers of the ridge formed by the inextensible reinforcing elements, crossed from one layer to the next, forming with the circumferential direction angles having a magnitude in the range of 10° to 45°on top of which in the radial direction is located treadmill tread, coupled with the two sides through two side walls, and reinforcement of the crest contains at least one layer of circumferential reinforcing elements, the ratio of the thickness of the unit crest on the end of the shoulder area to the thickness of the ridge in the middle of a circumferential plane has a value less than 1.20 and the ratio of the axial width of the layer of circumferential reinforcing elements to the axial width of the tread has a value of more than 0.5, preferably greater than 0.6 and even more preferably in excess of 0.65.

The so-called circumferential reinforcing elements are reinforcing elements, which form with the circumferential direction angles having a magnitude in the range from +2.5 to° up to 2.5° relative to 0�B0; .

The coefficient of the form N/S is the ratio of the height h of this pneumatic tire mounted on the rim, to the maximum axial width S of this pneumatic tire when the pneumatic tire is installed on the operating rim and inflated to its nominal pressure. Mentioned height H is defined as the difference between the maximum radius of the tread and the minimum radius side of this pneumatic tyres.

The layer of circumferential reinforcing elements according to the invention preferably is a continuous layer across its axial width.

Various thickness measurements are carried out on a transverse section of a pneumatic tire and pneumatic tire when performing measurements not inflated.

The values of the axial width of the layers of reinforcing elements are measured on a transverse section of a pneumatic tire, and pneumatic tire when performing measurements not inflated.

The axial width of the tread is measured between the shoulder ends in the case when this pneumatic tire is installed on the operating rim and inflated to its nominal pressure.

Shoulder end is determined in the shoulder area of a pneumatic tire by orthogonal projection on the outer surface p is aumatically bus point of intersection of the tangents to the surfaces of the outer axial end of the tread (top tread), on the one hand, and outside in the radial direction of the end of the sidewall, on the other hand.

The thickness of the ridge in the middle of a circumferential plane is defined as the distance along the radial direction between the tangent to the top of the tread in the middle of a circumferential plane and tangent to the most internal in the radial direction of the rubber mixture of the pneumatic tire in the middle of a circumferential plane.

The thickness of the unit crest on the shoulder end of the pneumatic tire is determined by the length of the orthogonal projection of her shoulder end on most interior in the radial direction, the rubber layer of the mixture of this pneumatic tyres.

More specifically, the present invention relates to a pneumatic tire type Poids-Lourds", for which the ratio of the height H of this pneumatic tire on the rim to its maximum axial width S, or the factor type, has a value not in excess of 0.80, and intended to equip medium-duty or heavy vehicles such as trucks, buses, trailers, etc.

Defined in this way pneumatic tire in accordance with the proposed invention allows for a given size and, more specifically, for a given coefficient type H/ST to improve the characteristics relating to durability and service life of such pneumatice the coy bus.

In comparison with the conventional pneumatic tire of the same size pneumatic tire in accordance with the invention is essentially identical to the thickness of the unit crest. It turns out that the thickness of the ridge in the middle of a circumferential plane may, in accordance with some variations of executions to be greater than the thickness of the unit crest on the shoulder end; the ratio of the thickness of the unit crest on the shoulder end to the thickness of the ridge in the middle of a circumferential plane preferably greater than 0.50 in.

From the point of view of the structure supporting the valve block-level ridge that is under the treadmill tread, this is expressed by means of the reinforcing layers of the reinforcement frame and the supporting reinforcement layers of the ridge, the radii of curvature of which in the axial direction (or longitudinal direction) are quasi-infinite at any point of the axial width of the zone having a width, comprising at least 50% of the width of the tread, and centered on the middle ring plane.

At the same time, the present invention provides an additional layer of rubber mixture compared with conventional pneumatic tire. This additional layer of rubber mixture is installed directly under the treadmill tread in such a way as to be C terouanne on average circumferential plane. The presence of such an additional layer allows to obtain the axial radius of curvature of the tread, less than the axial radius of curvature of the reinforcing layers of the reinforcement frame, and thus receive the imprint of the contact zone of the pneumatic tire with the ground, the corresponding normal prints. This additional layer of rubber compound allows also to some extent to protect the working layers of the ridge from oxidation.

Preferably, at least one layer forming the ridge structure, was completed in the radial direction under the "edge" or embossed tread pattern mainly longitudinal orientation, the most outside in the axial direction. Such an embodiment allows for greater rigidity mentioned relief drawing.

In accordance with a preferred embodiment of the present invention, the ratio of the thickness of the unit crest on the shoulder end to the thickness of the ridge in the middle of a circumferential plane has a value less than 1.15 and even more preferably less than 1,10.

Especially preferred that the ratio of the axial width of running the carriage of the tread to the maximum axial width of the pneumatic tire exceeded or was equal to 0.80 and more preferably exceeded or was equal to about 0.82. According to this preferred method carried out is I of the present invention, it is possible to obtain the highest efficiency from the point of view of its resistance to wear.

In accordance with a preferred embodiment of the present invention, the difference between the axial width of the widest in the axial direction of the working layer of the ridge and the axial width of the least wide in the axial direction of the working layer of the ridge has a value in the range from 10 mm to 30 mm

Even more preferably the most extensive in the axial direction of the working layer of the ridge position in the radial direction from the inside towards other working strata of the ridge.

In accordance with the preferred embodiment of the present invention, the distance between the end of the most extensive in the axial direction of the working layer of the ridge and the valve frame has a value in the range from 2 mm to 15 mm and preferably in the range from 5 mm to 7 mm in This embodiment of expressed more strongly accented than is usually the case in the pneumatic tire of this type, the curvature of the reinforcing rebar in the shoulder areas of pneumatic tires. The amount of rubber material added between the valve frame and the end of the reinforcing armature has, thus, a thickness less than the thickness of the material is usually introduced into the pneumatic tire of this type. This feature also improves durability and service life of pneumatic tires.

According the another preferred embodiment of the present invention is provided, that the axial width of at least one layer of circumferential reinforcing elements is less than the axial width of the widest in the axial direction of the working layer of the ridge.

Such axial width of at least one layer of circumferential reinforcing elements allows, in particular, the reduction of shear stresses between the working layers of the ridge and therefore further improves the characteristics of the resistance of pneumatic tyres.

In accordance with the preferred method of implementation of the invention, the reinforcing elements of at least one layer of circumferential reinforcing elements are metal reinforcing elements having a secant modulus to the relative elongation at the level of 0.7% in the range of from 10 GPA to 120 GPA and a maximum tangent modulus having a value of less than 150 GPA.

Preferably, the secant modulus of the reinforcing elements to relative elongation at the level of 0.7% had a value of less than 100 HPa, but exceeding 20 GPA and preferably greater than 30 GPA and 90 GPA, and even more preferably less than 80 GPA.

Also preferably, the maximum tangent modulus of the reinforcing elements had a value of less than 130 GPA, and even more preferred manner less than 120 GPA.

The modules described above are measured on the curve n the voltage of the tension in the function of relative elongation, defined pre-stress of 20 MPa, refer to the cross section of the metal reinforcing element, and tensile stress corresponds to the measured tension is given to the cross section of the metal reinforcing element.

Modules of the same reinforcing elements can be measured on a curve of the tensile stresses in the function of relative elongation, defined pre-stress at the level of 10 MPa, brought to a full cross-section of this reinforcing element, and tensile stress corresponds to the measured tension, brought to a full cross-section of this reinforcing element. Full cross-section of this reinforcing element represents a cross-section of the composite reinforcing element formed of metal and rubber, and rubber, in particular, enters this reinforcing element in the implementation phase of the vulcanization of pneumatic tires.

In accordance with this wording belonging to the full cross section of the reinforcing element, the reinforcing elements of at least one layer of circumferential reinforcing elements are metal reinforcing elements, characterized zechusim module when Rel is relative lengthening at the level of 0.7%, having a value in the range from 5 GPA to 60 GPA and a maximum tangent modulus having a value less than 75 GPA.

In accordance with a preferred embodiment of the invention the secant modulus of the reinforcing elements with a relative elongation at the level of 0.7% has a value less than 50 HPa and above 10 HPa, preferably contained in the range from 15 GPA up to 45 GPA and more preferably constituting less than 40 GPA.

Also preferably, the maximum tangent modulus of the reinforcing elements had a value of less than 65 GPA, and even more preferably less than 60 GPA.

In accordance with another preferred implementation, the reinforcing elements of at least one layer of circumferential reinforcing elements are metal reinforcing elements, characterized by a curve of tensile stress in the function of relative elongation with a small slope for small relative movements and essentially permanent and significant slope for large relative movements. Such reinforcing elements of the additional layer is usually called "two" supporting elements.

In accordance with another preferred embodiment of the invention sufficiently large and essentially constant slope mentioned cu is howling is manifested, since the relative elongation, having a value in the range from 0.1% to 0.5%.

The various characteristics mentioned above, the reinforcing elements are measured on the reinforcing elements taken from pneumatic tires.

Reinforcing elements, specially adapted to implement at least one layer of circumferential reinforcing elements in accordance with the invention, are, for example, Assembly, corresponding to the formula 21.23, the design of which is described by the expression 3×(0,26+6×0,23)of 4.4/6.6 SS. This cord rope with strands consists of 21 elementary wires, and these wires are connected by the formula 3×(1+6) with three strands twisted together, each of which consists of 7 wires, one of these wires forms the Central core and has a diameter of 26/100 mm, and 6 wires wound on the core and having a diameter of 23/100 mm. Such cord cable has a secant modulus at a relative elongation at the level of 0.7%to 45 GPA and a maximum tangent modulus equal to 98 GPA, and the values of these modules measured on a curve of tensile stress in the function of relative elongation determined with a pre-stress of 20 MPa, refer to the cross section of this metal reinforcing element, and rastgele the total voltage corresponds to the measured tension, refer to the cross section of this metal reinforcing element. On a curve of tensile stress, depending on the relative elongation determined with a preliminary voltage constituting 10 MPa, brought to a full cross-section of this reinforcing element, and tensile stress corresponds to the measured tension, brought to a full cross-section of this reinforcing element, this cord cable corresponding to the formula 21.23, is the secant modulus at a relative elongation at the level of 0.7%, equal to 23 GPA and a maximum tangent modulus, equal to 49 GPA.

Similarly, another exemplary embodiment of the reinforcing element is an Assembly corresponding to the formula 21.28, the design of which can be described by the expression 3×(0,32+6×0,28)6.2/9.3 SS. This cord the cord is the secant modulus at a relative elongation at the level of 0.7%, equal to 56 GPA and a maximum tangent modulus equal 102 HPa, and the values of these modules measured on a curve of tensile stress in the function of relative elongation determined with a pre-stress of 20 MPa, refer to the cross section of this metal reinforcing element, the tensile stress corresponds to the measured tension, given the WMD to the cross section of this metal reinforcing element. On a curve of tensile stress, depending on the relative elongation determined with a preliminary voltage constituting 10 MPa, brought to a full cross-section of this reinforcing element, and tensile stress corresponds to the measured tension, brought to a full cross-section of this reinforcing element, this cord cable corresponding to the formula 21.28, is the secant modulus at a relative elongation at the level of 0.7%, equal to 27 GPA and a maximum tangent modulus, equal to 49 GPA.

The use of such reinforcing elements in at least one layer of circumferential reinforcing elements, in particular, to maintain a satisfactory stiffness of this layer after the steps of molding and vulcanization in the implementation of conventional methods of manufacturing pneumatic tires.

In accordance with the second method of implementation of the present invention circumferential reinforcing elements may be formed of inextensible metal elements, cut in such a way as to form sections, the length of which is substantially less than the length of the circumference least long layer, but preferably more than 0.1 from the circumference, and the gaps between these areas is displaced in the axial direction relative to each is entrusted friend. Even more preferably, the modulus of elasticity in tension per unit width of said additional layer had a value less than the value of the modulus of elasticity in tension, measured under the same conditions, for the most extensible working layer of the ridge. This method of implementation allows a fairly simple way to add a layer of circumferential reinforcing elements is the elastic modulus, which can easily be adjusted by selection of the spacing between plots of the same number), but which in all cases is less than the value of the elastic modulus for the layer formed of the same metal elements, but solid, and the modulus of elasticity of an additional layer is measured on volcanoserver.com layer cut elements taken from pneumatic tires.

In accordance with a third method of implementing the present invention circumferential reinforcing elements are corrugated metal reinforcing elements, the ratio a/λ the amplitude of waviness to the wavelength has a value not exceeding 0,09. Preferably, the modulus of elasticity in tension per unit width of the additional layer had a value less than the value of the modulus of elasticity in tension, measured under the same conditions, for the most extensible working SL is I of the ridge.

Mentioned metal reinforcing elements preferably are cord cables made of steel.

In accordance with another embodiment of the present invention, at least one layer of circumferential reinforcing elements is positioned radially between two working layers of the ridge.

In accordance with the above option perform the layer of circumferential reinforcing elements allows for a more significant way to limit the compression of the reinforcing elements of the valve frame than a similar layer that is hosted in the radial direction outside of the working layers. This layer is preferably separated in a radial direction from the valve frame using at least one working layer of the ridge in such a way as to limit the mechanical stresses mentioned reinforcing elements and not to create excessive fatigue stresses.

Even more preferably, in the case of the layer of circumferential reinforcing elements positioned radially between two working layers of the crest values of the axial width of the working layers of the ridge, adjacent in the radial direction to the layer of circumferential reinforcing elements exceeded the axial width of the mentioned layer of circumferential reinforcing elements, upomyanutye layers of the ridge, adjacent to the layer of circumferential reinforcing elements, on either side of the Equatorial plane and in the immediate axial continuation of the mentioned layer of circumferential reinforcing elements were connected to each other at a certain axial width, with the possibility of separation, with the help of made of profiled rubber compound elements on at least the remaining part of the total width of the two mentioned working groups.

The presence of such connections between the working layers of the ridge, adjacent to the layer of circumferential reinforcing elements, additionally reduces mechanical the tensile stresses acting on the most outside in the axial direction of the circumferential reinforcing elements located closest to said connection.

The thickness of the rubber profiled elements ensuring the separation of the working layers of the crest, measured over the ends of the least wide working layer ridge will be at least 2 mm and preferably will have a value in excess of 2.5 mm

In this case, the expression "United layers should understand the layers corresponding reinforcing elements which are separated from each other in the radial direction at a distance of not more than 1.5 mm, and referred to the thickness of the rubber mixture of areeda in the radial direction between the respective forming, the top and bottom, the above-mentioned layers of the reinforcing elements.

To reduce the tensile stresses acting on the most outside in the axial direction of the circumferential reinforcing elements, in the present invention, the angle formed by the reinforcing elements of the working layers of the ridge with the County direction, has a value less than 30° and preferably less than 25°.

In accordance with another preferred embodiment of the present invention, layers of comb containing reinforcing elements, crossed from one ply to the other and forming with the circumferential direction variable angles along the axial direction, and the above-mentioned angles have higher values on the outside in the axial direction of the edges of the layers of reinforcing elements in comparison with the values of these angles for the above elements is measured at the level of the average circumferential plane. This variant implementation of the invention allows to increase the circumferential rigidity in some areas and, conversely, to reduce the stiffness in other areas, in particular, to reduce the compression stress of the reinforcement frame.

According to another variant implementation of the invention the valve of the ridge is supplemented from the outside in the radial direction, at least one additional protective the m layer, formed from elastic reinforcing elements oriented in relation to the district under the direction angle having a value in the range from 10° to 45°and in the same direction as the angle formed by the inextensible reinforcing elements of the working layer of the ridge, which is adjacent in the radial direction to that of the protective layer.

Mentioned protective layer may have an axial width less than the axial width of the least wide working layer of the ridge. Mentioned protective layer may also have an axial width greater than the axial width of the least wide working layer of the ridge so that the protective layer overlaps the edge of the least wide working layer of the ridge and in the case when the least wide working layer of the crest is the top in the radial direction of the working layer so that the protective layer was connected, in the axial continuation of the additional reinforcement with the widest working layer of the ridge at a certain axial width, with the possibility of separation from the outside in the axial direction by means of a rubber profiled elements having a thickness at least equal to 2 mm Protective layer formed elastic reinforcing elements in the above-mentioned case may be, on the one hand, and, if necessary, removed from the edges of the least mentioned W is wide working layer of the ridge using a rubber profiled element, having a thickness essentially smaller than the thickness of the rubber profiled elements, separating the edges of the two working layers of the ridge; and on the other hand, may have an axial width less than or greater than the axial width of the widest working layer of the ridge.

In accordance with any of the above ways of implementation of the invention, the armature of the crest can still be added to the inside in the radial direction and between the valve frame and the inner radial direction of the working layer of the ridge closest to the said valve frame, triangulation layer formed from made of steel metal inextensible reinforcing elements forming with the circumferential direction an angle, the value of which exceeds 60° and which has the same direction as the direction of the angle formed with the circumferential direction of the reinforcing elements of the layer of the ridge closest to the radial direction of the valve frame.

The invention is further explained in the description of variants of its implementation, with reference to the figures of the attached drawings, in which:

- Figure 1 is a schematic view in axial or vertical section of a pneumatic tire in accordance with one method of implementation of the present invention,

- Figure 2 the submitted is a schematic view in vertical section of a pneumatic tire in accordance with the second method of implementation of the present invention,

- Figure 3 is a schematic view in vertical section of a pneumatic tire in accordance with the third mode of implementation of the present invention,

- Figure 4 represents a schematic view in vertical section of a pneumatic tire in accordance with the fourth method of implementation of the present invention,

- Figure 5 is a schematic view of the pneumatic tire in a meridional section, illustrating the definition of the shoulder end.

For ease of understanding, the following drawings data in Appendix figures are pneumatic tire on a scale different from the real. These figures represented only half of a pneumatic tire in cross section, which continues in a symmetric manner with respect to the axis x-X', which represents the average ring plane, or Equatorial plane of this pneumatic tyres.

Figure 1 shows the pneumatic tire 1 size 295/60 R 22.5 X has a factor of the form H/S, equal to 0.60, where H denotes the height of the pneumatic tire 1 on its mounting rim and S denotes the maximum axial width of this pneumatic tyres. Pneumatic tire 1 includes a radial reinforcement of the frame 2, is fixed at two sides, not shown in the figure. The valve frame formed of a single layer of metal is ski cord cables. The fixture frame 2 is fastened by means of reinforcement ridge 4 formed in the radial direction, in the direction from inside to outside:

- first working layer 41 formed of inextensible metal and not bonded cord cables formula 11.35, continuous throughout the width of this layer and oriented at an angle of 18°,

the layer of circumferential reinforcing elements 42 formed is made of steel "two" metal cord cords formula 21×28,

the second working layer 43 formed of inextensible metal and not bonded cord cables formula 11.35, continuous throughout the width of this layer is oriented at an angle of 18° and intersecting with metal cord cords mentioned layer 41,

protective layer 44 formed of an elastic metal cord ropes of formula 18×23.

On top of the reinforcement ridge is located treadmill tread 5.

The measured values of the thickness of the unit crest on each shoulder ends 6 and Central circumferential plane x-X' amount of 31.8 mm referred to the shoulder ends and 30.1 mm in average circumferential plane. The ratio of the thickness of the unit crest on the shoulder end to the thickness of this unit crest in the middle ring plane is equal to 1,06, i.e. has a value less than 1,15 in accordance with the proposed invented the eat.

At the same time, the axial width of the tread L has a value of 262 mm, and the ratio of the axial width of the tread L to the maximum axial width S of this pneumatic tire is about to 0.89, i.e. exceeding 0.80.

The axial width L41 first working layer 41 of the ridge is 248 mm for pneumatic tires of the usual form, essentially smaller than the width L of the tread, which in this case is 262 mm Difference between the width of the tread and width L41 is, thus, 14 mm and, therefore, less than 15 mm in accordance with the invention.

The axial width L43 second working layer 43 of the crest is 230 mm, the Difference between the widths L41 and L43 is 18 mm and, therefore, were made in the range from 10 mm to 30 mm in accordance with the invention.

As for the full axial width L42 of the layer of circumferential reinforcing elements 42, it is 188 mm width Ratio L43 to the width of the tread is equal to 0.71 and, therefore, exceeds 0.5.

The last so-called protective layer of the ridge 44 has a width L44, component 188 mm

In accordance with the invention on the whole width of the layer of reinforcing elements 42 and population reinforcement layers ridge is quasi-infinite radius to which Elitny. In accordance with this configuration, the reinforcing elements oriented in the circumferential direction, are less sensitive to the danger of rupture, in particular, on their outer axial ends.

Outside the outer axial ends of the layer of circumferential reinforcing elements of the working layers of the ridge are of such curvature that the distance between the outer axial end of the widest working layer 41 and the valve frame is approximately 5 mm

Presented in figure 2, the pneumatic tire 1 is different from pneumatic tires, are presented in figure 1, so that the two working layers 41 and 43 of the ridge, on each side of the Equatorial plane and on the continuation in the axial direction of the layer of circumferential reinforcing elements 42 are connected to each other at a certain axial width I: this cord wires of the first working layer 41 and cord cables of the second working layer 43 on the axial width of the compounds I of the two layers are separated from each other in the radial direction by a layer of rubber, the thickness of which is minimal and corresponds to a double thickness rubber calendering layer bonded metal cord ropes of formula 27.23 that makes up each working layer 41, 43, or equal to 0.8 mm For the remainder of the total width of the two working layers of the two working layers 1, 42 ridge separated from each other by means of a rubber profiled element, not represented on this figure, the thickness mentioned profiled element is increasing in the direction from the axial end of the connection zone to the end of the least wide working layer. This profiled element preferably has a width sufficient to overlap in the radial direction of the end of the widest working layer 41, which in this case here is a working layer that is closest in the radial direction of the valve frame.

Presented in figure 3, the pneumatic tire 1 is different from pneumatic tires, are presented in figure 1, the fact that it contains additional so-called triangulation layer of reinforcing elements 45 having a width essentially equal to the width of the active layer 43. Reinforcing elements of this triangulation layer 45 is formed with the circumferential direction an angle of about 60°and oriented in the same direction as the reinforcing elements of the working layer 41. This layer 41 allows, in particular, to promote the perception of effort transverse compression, which is the object of the totality of the reinforcing elements in the area of the crest of pneumatic tires.

Presented in figure 4 pneumatic is in 1 differs from the pneumatic tire, presented in figure 1, so that the said layer of circumferential reinforcing elements is outside in the radial direction with respect to the working layers 41 and 43 of the crest and, therefore, is adjacent in the radial direction to the working layer 43, the most narrow in the axial direction.

Figure 5 presents a schematic view in vertical axial section of the pneumatic tire 1, which shows the first 7 tangent to the outer surface in the axial direction of the end of the tread 8. The surface of the tread is defined by the outer radial surface or top of the relief pattern, not shown in the Appendix figures. The second tangent 9 to the outer surface in the radial direction of the end of the sidewall 10 intersects the first mentioned 7 tangent at the point 11. The orthogonal projection of this point on the outer surface of the pneumatic tire defines the end of the shoulder area 6 of this pneumatic tyres.

The axial width L of the tread is measured in such a way between the two ends of the mentioned shoulders 6.

Figure 5 also presents the measurement of the thickness of the unit crest on the end of the shoulder zone 6, the length 12 of the orthogonal projection 13 of the end shoulder area 6 on most interior in the radial direction the AI layer of rubber mixture 14 of this pneumatic tyres.

Figure 5 also presents the thickness measurement unit crest in the middle district of plane XX', defined as the distance of 15 along the radial direction between the tangent to the top of the tread 8 in the middle of a circumferential plane and tangent to the most internal in the radial direction of the rubber layer of the mixture 14 of this pneumatic tire in the middle of a circumferential plane.

Comparative tests using pneumatic tire, sold in accordance with the invention and with the configuration illustrated in figure 1, and identical reference pneumatic tires, but implemented in accordance with the conventional configuration.

This conventional pneumatic tire, in particular, does not contain an intermediate layer of circumferential reinforcing elements located between the working layers of the ridge, reinforcing elements oriented at an angle of 18°and the width of the tread of this pneumatic tire is 262 mm

The first tests of the resistance of pneumatic tyres were carried out by equipping identical vehicles each of these pneumatic tyres and complete runs of each of these vehicles in a straight line, and the aforementioned pneumatic tire was subjected to loads exceeding the surrounding rated for the load, to speed up trials of this type.

The reference vehicle equipped with conventional pneumatic tires, had the load on one pneumatic tire on the level of 3600 kg at the beginning of the run, which was changed until the value of 4350 kg by the end of the run.

Vehicle equipped with pneumatic tires in accordance with the invention, had a load on one pneumatic tire on the level of 3800 kg at the beginning of the run, which was changed until the value of 4800 kg by the end of the run.

The tests showed that the vehicle equipped with pneumatic tires in accordance with the invention, has stood the mileage, the length of which 46% over the long run reference vehicles. Thus, it was found that the pneumatic tire in accordance with the invention have significantly higher performance than the reference pneumatic tyres, despite the fact that they were exposed to higher loads.

Were held and other test on the test machine, specify the load pneumatic tires and drift angle. These tests were conducted for a pneumatic tire in accordance with the invention using a load exceeding 6%, and the drift angle, exceed is it 10% of the relevant parameters, used in similar tests with reference pneumatic tyres.

The results obtained demonstrate the gain in length mileage pneumatic tire in accordance with the invention, constituting more than 40% compared with the length of the mileage for the reference of the pneumatic tires.

1. Pneumatic tyre for which the coefficient of the form H/S has a value in excess of 0.55, provided with radial reinforcement frame and containing the valve crest formed of at least two working layers of the ridge, formed of inextensible reinforcing elements, crossed from one layer to the next, forming with the circumferential direction angles in the range from 10 to 45°on top of which in the radial direction is located treadmill tread, coupled with the two sides by means of two sidewalls, and the armature of the crest contains at least one layer of circumferential reinforcing elements that differ the fact that the ratio of the thickness of the unit crest on the end of the shoulder area to the thickness of the ridge in the middle of a circumferential plane has a value less than 1.20, the ratio of the axial width of at least one layer of circumferential reinforcing elements to the axial width of the tread has a value greater than 0.5 and preferably more than 0.6.

2. Pneumatic the Skye tire according to claim 1, characterized in that the ratio of the axial width of at least one layer of circumferential reinforcing elements to the axial width of the tread has a value in excess of 0.65.

3. Pneumatic tire according to one of claims 1 or 2, characterized in that the ratio of the thickness of the unit crest on the shoulder end to the thickness of the ridge in the middle of a circumferential plane has a value less than 1.15 and preferably less 1,10.

4. Pneumatic tire according to claim 1, characterized in that the ratio of the axial width of the tread to the maximum axial width of the pneumatic tire is greater than or equal to 0.80 and preferably greater than or equal to about 0.82.

5. Pneumatic tire according to claim 1, characterized in that the layer of circumferential reinforcing elements is continuous throughout its axial width.

6. Pneumatic tire according to claim 1, characterized in that the coefficient of the form H/S has a value less than 0.80.

7. Pneumatic tire according to claim 1, characterized in that the most extensive in the axial direction of the working layer of the ridge is located inside relative to other operating segments of the ridge.

8. Pneumatic tire according to claim 1, characterized in that the difference between the axial width of the widest in the axial direction of the working layer of the ridge and the axial width of the least wide in the axial direction of the working layer of the ridge has a value in the range from 10 to 30 mm

9. Pneumatic tire according to claim 1, characterized in that the distance between the end of the most extensive in the axial direction of the working layer of the ridge and the valve frame has a value in the range from 2 to 15 mm and preferably in the range of from 5 to 7 mm.

10. Pneumatic tire according to claim 1, characterized in that the axial width of at least one layer of circumferential reinforcing elements is less than the axial width of the widest in the axial direction of the working layer of the ridge.

11. Pneumatic tire according to claim 1, characterized in that at least one layer of circumferential reinforcing elements is positioned radially between two working layers of the ridge.

12. A pneumatic tyre according to claim 11, characterized in that the axial width of the working layers of the ridge, adjacent in the radial direction to the layer of circumferential reinforcing elements exceeds the axial width of the layer of circumferential reinforcing elements.

13. Pneumatic tire according to item 12, characterized in that the layers of the ridge, adjacent to the layer of circumferential reinforcing elements are interconnected on either side of the Equatorial plane and in the immediate axial continuation of the layer of circumferential reinforcing elements, at a certain axial width, with the possibility of separation by using made of profiled rubber compound elements, IU the greater extent, the remaining part of the total width of the mentioned working groups of the ridge.

14. Pneumatic tire according to claim 1, characterized in that the reinforcing elements of at least one layer of circumferential reinforcing elements are metal reinforcing elements having a secant modulus to the relative elongation at the level of 0.7% in the range from 10 to 120 GPA and a maximum tangent modulus less than 150 GPA.

15. Pneumatic tire 14, wherein the secant modulus of the reinforcing elements to relative elongation at the level of 0.7% has a value less than 100 GPA and preferably greater than 20 GPA, and even more preferably enclosed in the range from 30 to 90 GPA.

16. Pneumatic tire 14, characterized in that the maximum shear modulus of the reinforcing elements has a value less than 130 GPA and preferably less than 120 GPA.

17. Pneumatic tire according to claim 1, characterized in that the reinforcing elements of the layer of circumferential reinforcing elements are metal reinforcing elements, characterized by a curve of tensile stress in the function of relative elongation with a small slope for small values of relative elongation and essentially constant and a large slope for higher values of relative extension.

18. Pneumatic tire according to claim 1 characterized in, that the reinforcing elements of at least one layer of circumferential reinforcing elements are metal reinforcing elements, cut in such a way as to form sections of a length less than the circumference least an extended layer, but exceed 0.1 referred to the circumference, and the gaps between these areas is displaced in the axial direction relative to each other, and the modulus of elasticity in tension per unit width of said additional layer preferably has a value smaller values of modulus of elasticity in tension, measured under the same conditions, for the most extensible working layer of the ridge.

19. Pneumatic tire according to claim 1, characterized in that the reinforcing elements of at least one layer of circumferential reinforcing elements are corrugated metal reinforcing elements, the ratio a/λ the amplitude of waviness and to the wavelength λ has a value not exceeding 0,09, and the modulus of elasticity in tension per unit width of said additional layer preferably has a value less than the value of the modulus of elasticity in tension, measured under the same conditions, for the most extensible working layer of the ridge.

20. Pneumatic tire according to claim 1, characterized in that the angle formed by the reinforcing what they are elements of the working layers of the ridge with the County direction, has a value less than 30° and preferably less than 25°.

21. Pneumatic tire according to claim 1, characterized in that the layers of comb containing reinforcing elements, crossed from one ply to the other and forming with the circumferential direction variable angles along the axial direction.

22. Pneumatic tire according to claim 1, characterized in that the armature of the ridge is supplemented from the outside in the radial direction at least one additional protective layer formed of the elastic reinforcing elements oriented in relation to the district under the direction angle having a value in the range from 10 to 45°and the same direction as the angle formed by the inextensible reinforcing elements of the working layer of the ridge, which is adjacent in the radial direction to that of the protective layer.

23. Pneumatic tire according to claim 1, characterized in that the armature of the ridge further comprises a triangulation layer formed of inextensible metal reinforcing elements forming with the circumferential direction angles larger than 60°.



 

Same patents:

FIELD: transportation.

SUBSTANCE: invention is attributed to pneumatic tire which has radial reinforcement of frame and contains crest reinforcement formed by at least two crest working layers created of inextensible reinforcing elements intercrossing from one layer to another forming with circumferential direction the angles in the range of 10 to 45°. Tire tread connected with two beads by means of two sidewalls is located over this radial frame reinforcement in radial direction. Crest reinforcement contains at least one layer of circumferential reinforcing elements which has axial width less than axial width of at least one of crest working layers. Ratio of axial width of at least one layer of circumferential reinforcing elements to axial width of tire tread is equal to value which exceeds 0.6 and preferentially exceeds 0.65. Ratio of tire tread axial width to maximum axial width of this pneumatic tire is equal to value exceeding 0.89.

EFFECT: tire strength and reliability is improving.

17 cl, 5 dwg

FIELD: transport engineering.

SUBSTANCE: invention relates to pneumatic tyre with radial carcass reinforcement over which ridge reinforcement consisting of at least two working layers of ridge formed by metal reinforcement members is arranged in radial direction. Said reinforcement members intersect from one layer to the other forming angles of 10 to 35° with circumferential direction. Ridge reinforcement includes at least one additional reinforcement formed by metal reinforcement members orientated in circumferential direction. Additional reinforcement consists of at least two layers of metal members of small diameter not exceeding 0.6 mm. Metal reinforcement members of additional reinforcement are assemblies, type 1 x n where n is from 2 to 5, made of steel featuring high breaking strength SHT, and diameter of threads is within 12/100 and 30/100.

EFFECT: increased strength and wear resistance of tyres.

10 cl, 3 dwg

FIELD: automotive industry.

SUBSTANCE: proposed pneumatic tire has crown, two side strips and two beads as well as carcass reinforcement secured in each bead and crown reinforcement provided with working unit and protective unit form inside to outside in radial direction. Protective unit contains at least one layer of parallel reinforcement circumferentially orientated elements. Layer of protective unit is formed by reinforcement elements made of aromatic polyamide with initial modulus of elasticity not less than 1000 cN/tex and breaking strength exceeding 65 cN/tex.

EFFECT: increased strength of pneumatic tire crown.

20 cl, 5 dwg

FIELD: road vehicles.

SUBSTANCE: proposed tire has radial body with one or several breaker layers on place close to outer surface, and strengthening layer with nylon cord wound in spiral over breaker. It is desirable that tread belt of tire be formed by underlayer and outer layer, one placed on the other, elasticity and/or hardness characteristics of first layer remaining stable at temperatures within 20 and 110oC.

EFFECT: improved performance characteristics of tires.

23 cl, 4 tbl, 2 dwg

The invention relates to the automotive industry

The invention relates to road transport

FIELD: road vehicles.

SUBSTANCE: proposed tire has radial body with one or several breaker layers on place close to outer surface, and strengthening layer with nylon cord wound in spiral over breaker. It is desirable that tread belt of tire be formed by underlayer and outer layer, one placed on the other, elasticity and/or hardness characteristics of first layer remaining stable at temperatures within 20 and 110oC.

EFFECT: improved performance characteristics of tires.

23 cl, 4 tbl, 2 dwg

FIELD: automotive industry.

SUBSTANCE: proposed pneumatic tire has crown, two side strips and two beads as well as carcass reinforcement secured in each bead and crown reinforcement provided with working unit and protective unit form inside to outside in radial direction. Protective unit contains at least one layer of parallel reinforcement circumferentially orientated elements. Layer of protective unit is formed by reinforcement elements made of aromatic polyamide with initial modulus of elasticity not less than 1000 cN/tex and breaking strength exceeding 65 cN/tex.

EFFECT: increased strength of pneumatic tire crown.

20 cl, 5 dwg

FIELD: transport engineering.

SUBSTANCE: invention relates to pneumatic tyre with radial carcass reinforcement over which ridge reinforcement consisting of at least two working layers of ridge formed by metal reinforcement members is arranged in radial direction. Said reinforcement members intersect from one layer to the other forming angles of 10 to 35° with circumferential direction. Ridge reinforcement includes at least one additional reinforcement formed by metal reinforcement members orientated in circumferential direction. Additional reinforcement consists of at least two layers of metal members of small diameter not exceeding 0.6 mm. Metal reinforcement members of additional reinforcement are assemblies, type 1 x n where n is from 2 to 5, made of steel featuring high breaking strength SHT, and diameter of threads is within 12/100 and 30/100.

EFFECT: increased strength and wear resistance of tyres.

10 cl, 3 dwg

FIELD: transportation.

SUBSTANCE: invention is attributed to pneumatic tire which has radial reinforcement of frame and contains crest reinforcement formed by at least two crest working layers created of inextensible reinforcing elements intercrossing from one layer to another forming with circumferential direction the angles in the range of 10 to 45°. Tire tread connected with two beads by means of two sidewalls is located over this radial frame reinforcement in radial direction. Crest reinforcement contains at least one layer of circumferential reinforcing elements which has axial width less than axial width of at least one of crest working layers. Ratio of axial width of at least one layer of circumferential reinforcing elements to axial width of tire tread is equal to value which exceeds 0.6 and preferentially exceeds 0.65. Ratio of tire tread axial width to maximum axial width of this pneumatic tire is equal to value exceeding 0.89.

EFFECT: tire strength and reliability is improving.

17 cl, 5 dwg

FIELD: transportation.

SUBSTANCE: invention is attributed to pneumatic tire for which factor of H/S type has value exceeding 0.55 and which has radial reinforcement of frame and contains flange reinforcement formed by at least two flange working layers created of inextensible reinforcing elements intercrossing from one layer to another forming with circumferential direction the angles in the range of 10 to 45°. Tyre tread connected with two beads by means of two sidewalls is located over this radial frame reinforcement in radial direction. Crest reinforcement contains at least one layer of circumferential reinforcing elements. Value of ratio of crest block width at the end of shoulder area to crest block width at center circumferential plane is less than 1.20, and value of ratio of axial width of at least one layer of circumferential reinforcing elements to axial width of tire tread exceeds 0.5 and preferably exceeds 0.6.

EFFECT: tire strength and reliability is improving.

23 cl, 5 dwg

FIELD: transport.

SUBSTANCE: proposed pneumatic tire incorporates a carcass and a tread formed by, at least, two tread layers made up of rigid reinforcing elements with alternating crossed-over layers forming, with the peripheral direction, the angles varying from 10° to 45° on the tread crown zone. The said tread crown zone is jointed to two beads by side walls. The tread side thickness-to-tread center thickness ratio makes below 1.20 and the tread crown zone-to-tire total width ratio exceeds or equals 0.89.

EFFECT: higher strength and reliability.

25 cl, 5 dwg

FIELD: transport.

SUBSTANCE: invention relates to automotive industry. Air tire has breaker structure that comprises first breaker layer (51), second breaker layer (52) arranged in radial-inner position relative to first breaker layer (51), third breaker layer (53) arranged in radial inner position relative to first (51) and second (52) breaker layers. Every breaker layer (51, 52, 53) comprises multiple elongated reinforcing elements arranged above 1st, 2nd and 3rd breaker angles. Note here that 1st and 2nd angles vary from 15 to 40 degrees. Second angle has opposite sign relative to 1st breaker angle. Third breaker angle features magnitude varying from 40 to 90 degrees and opposite sign with respect to second angle. Breaker structure comprises also breaker layer (54) arranged at zero degree angle relative to 1st breaker layer (51) comprising elongated reinforcing elements arranged to make, in fact, zero breaker angle,.

EFFECT: perfected performances.

21 cl, 11 dwg

Pneumatic tire // 2405682

FIELD: transport.

SUBSTANCE: invention relates to automotive industry, particularly to heavy-duty radial pneumatic tires of relatively small size ratios. Tire comprises toroidal carcass arranged atop two tire beads, undertread band arranged on outer side along carcass radial direction, and tread arranged on outer along radial direction of undertread belt. Undertread belt comprises at least one circular layer arranged on outer side along radial direction of carcass rim part and made up of multiple rubberised cords running along the tire equatorial axis, and at least two inclined layers of undertread belt arranged on circular layer of undertread belt, each being formed by multiple rubberised cords running inclined to tire equatorial axis O. Width of undertread belt circular layers makes at least 60% of the tire total width. Width of at least one inclined layer of undertread belt exceeds that of circular layer. Note that elasticity modulus of the first cords arranged on outer side of undertread belt circular layer is smaller than that of second cords arranged on inner side, across direction of the first cords.

EFFECT: longer life.

10 cl, 3 dwg

FIELD: transport.

SUBSTANCE: invention relates to automotive industry. Proposed tire features ellipticity factor equal to or under 50%. Breaker layers 9, apart from outer breaker layer 10, are arranged so that breaker layer cords are arranged at θ 10-70° relative to tire lengthwise direction. Said outer breaker layer 10 is made of coiled layer 12 of coiled tape provided with steel cords in tire lengthwise direction. Said breaker layer 10 comprises section 10A located between fold position Po on opposite sides from tire equator and fold position 10B bent in U-like manner from position Po toward tire equator. Section 10A features width varying from 70% to 80% of width of contact between tread and ground while fold section 10 B has width varying from 5.0 mm to 0.5 of width.

EFFECT: longer life.

9 cl, 8 dwg

Pneumatic tire // 2456168

FIELD: transport.

SUBSTANCE: invention relates to automotive industry. Tire carcass ply is laid between two double beads. Breaker ply is recessed on carcass ply outer peripheral side in tread section. Tread is provided with multiple main grooves extending along tire circle. Maximum depth of each main groove varies from 8.5 mm to 15.0 mm. Relationship between height of actual tire profile SH and that of profile SHstd calculated from tire size is set to 0.97≤α≤0.99. Relationship between contact areas makes 65-70% under conditions of measurements whereat air pressure makes 200 kPa and load making 50% of bearing capacity at said air pressure. Mean contact pressure P varies from 300 kPa to 400 kPa.

EFFECT: longer life, efficient braking on moistened surface.

13 cl, 4 dwg, 1 tbl

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