ES2942787A1 - LESS POLLUTING TIRE WITH LONGER USEFUL LIFE (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

The wheel object of the invention has a casing surrounding a tire volume (2) in contact with a rim (1). Two insulating, flexible and elastic surfaces (5, 22, 6) are incorporated on the inside and outside of the walls (3, 20, 21) of the casing. Likewise, a series of main radial elements (11, 24) and auxiliary radial elements (8, 23) arranged alternately and separated by elastomers (16, 27) between the carcass and the tread band (9) are incorporated. The latter is made with materials that are biodegradable or with less toxicity due to the emission of microplastics, and is incorporated by mechanical or adhesive procedures. This design allows to reduce the oxidation of the vulcanized rubber, prolonging the useful life of the tire, also reduces the emission of polluting and toxic microplastics, (Machine-translation by Google Translate, not legally binding)

Description

LESS POLLUTING TIRE WITH LONGER USEFUL LIFE

Field of technique

The invention is framed within the field of wheels for different types of vehicles.

state of the art

Today's tires are mostly made up of a mixture of vulcanized natural rubber and synthetic rubber, together with other structural reinforcement components, such as metallic or polyester threads. In its preparation, the material called carbon black is used as a pigment and reinforcement for the production of rubber.

Carbon black is a known carcinogen associated with significant greenhouse gas emissions during its production process.

On the other hand, the manufacture of tires requires a significant consumption of oil for the production of synthetic rubber.

Tread wear during wheel rolling is a major source of microplastics, produced by the billions of tires installed on vehicles and used routinely for passenger and freight road transport around the world. world. The vast majority of these vulcanized rubber particles are usually deposited on the ground, in riverbeds or are displaced to the sea.

The Tire Industry Project initiative, which includes the eleven main international tire manufacturers, has carried out between 2011 and 2019, ten studies regarding the effect that the emission of these particles can have on the environment and its toxicity to health. These studies indicate that it is common for these microplastic residues to be deposited on the ground and in the aquatic environment, although the results on the risk to people, as well as to marine and terrestrial fauna and flora are not conclusive and require new studies. .

At the same time, a study carried out by the UK Department of Environment, Food and Rural Affairs' Air Quality Expert Group, with the participation of several universities and research centres, including the Committee on the Medical Effects of Air Pollutants (Committee on the Medical Effects of Air Pollutants - COMEAP), concluded in 2019 that particulate emissions from road traffic not related to engine combustion potentially have a greater impact on public health than those emitted by fuel combustion. COMEAP estimated in 2010 a UK-wide impact equivalent to 29,000 deaths per year from non-combustion related emissions, in the absence of a detailed breakdown between the effects due to emissions from brake wear, asphalt or other causes, and those produced by the wear of the tread band.

Likewise, a recent October 2021 study from the European Patent Office on global innovation trends in plastics, recycling, circular design and alternative sources, indicates that vulcanized rubber is difficult to recycle and cannot be reused. shape later.

In this sense, the treatment of discarded tires constitutes an environmental problem of the first order given the difficulty of recycling them and due to the long duration of some of their constituent materials.

In this way, the objective technical problem to be solved by the invention consists in manufacturing a tire that reduces, on the one hand, the emission of toxic and polluting microplastics as a consequence of tread wear, and, on the other hand, can increase its useful life. reducing the environmental impact related to its production and recycling.

Description of the invention

The useful life of the tire is determined by the wear of the tread, as well as by the oxidation of the vulcanized rubbers of its structure, due to its contact with oxygen and ozone in the air, which causes the rubber to degrade. , deteriorating its physical and mechanical properties, losing the elastic recovery capacity of the carcass, in a process also called "tire crystallization".

For this reason, the design of the tire of the invention seeks to solve these two problems in order to facilitate the manufacture of more durable tires, as well as reduce polluting emissions from the tread.

To this end, a new structure is developed that allows the incorporation into the tread of materials that produce less toxicity and less environmental impact as a result of wear. This new structure allows, in turn, its incorporation into the tire carcass without the need to use a vulcanization process, a necessary condition so that the materials that make up the tread can be less polluting and have less toxicity.

Since the rate of wear of these alternative materials due to friction is usually greater than the rate of degradation by oxidation of vulcanized rubber, it is also necessary to establish design procedures that allow frequent replacement of the tread as it wears out. produces this wear, making the cycle of use of the tire is determined exclusively by the useful life of the vulcanized rubber constituting its pneumatic structure.

In the same way, in order to increase this useful life of the tire casing, characteristics are incorporated into the design that make it possible to substantially delay the oxidation process of the vulcanized rubber.

It must be taken into account that despite the fact that similar materials are currently used for the manufacture of the casing and the tread, which are joined by a vulcanization process, the physical requirements are different for both components. The tread needs to have a significant grip capacity, while the carcass especially requires elasticity, resistance and durability.

These different needs allow the use of different materials in the tread and in the carcass of the tire, making possible the new design and manufacturing process developed in the invention.

The materials for the tread band are chosen from different materials such as biodegradable rubber, which is beginning to have an important development, or the incorporation into the rubber of interstitial plugs that have a natural capacity for degradation (such as cork elements).

The constituent material of the carcass that surrounds the tire volume continues to be a mixture of vulcanized rubbers, given that the current state of the art does not allow its easy substitution by other less polluting compounds, considering this substitution as a desirable objective for development. of new materials in the future.

In this way, the tire object of the invention incorporates the two characteristics described above, namely:

I - A separation of the carcass with respect to the tread, which allows the use of different materials in both. To do this, an annular structure of intermediate radial elements is incorporated, located between the two, and which have a higher resistance to perforations than rubber, which also increases safety against punctures.

This structure of radial elements also makes it easier for the fixing of the tread band to the tire volume to be carried out by alternative procedures to the current vulcanization process. An example of these procedures can be a mechanical union, or the use of adhesives.

II - The incorporation of an insulating, flexible and elastic coating on the inside and outside of the walls of the tire volume that delays the oxidation process of the vulcanized rubber, with a degree of flexibility and elasticity higher than that of these walls.

It must be taken into account that this process begins with the outer layers that are directly in contact with the ozone or diatomic oxygen existing in the atmosphere, and gradually moves towards the inner areas of the rubber. In this way, the incorporation of an insulating surface that prevents this contact between rubber and oxygen can greatly delay its degradation, considerably increasing the useful life of the tire.

To facilitate recycling, when the time comes, biodegradable materials or those with a lower ecological impact can be used on the insulating surface. Given the foreseeable shorter duration of these materials with respect to the useful life of the tire, the repair or replacement of the insulating surface can be carried out periodically, making it coincide, if desired, with the process of replacing the tread with reason for its wear.

In addition, the walls of the tire volume usually have a thinner area halfway from the rim, which makes it the part where oxidation can be faster and where there is a greater loss of elasticity and mechanical properties, becoming in the part most susceptible to degrade and condition the operability of the wheel. An alternative design may also consist in increasing the thickness of the casing wall in this area.

The prolongation of the useful life of the tire by incorporating the characteristics of the invention provides a solution to the problem of degradation by oxidation of vulcanized rubber that has been known since the appearance of the first tires at the end of the 19th century, and that Since then it has had a very important importance from the economic, environmental and road safety point of view.

The use of materials in the tread that are different from vulcanized rubber, which is still used in the invention as the main constituent of the carcass of the tire volume, allows the use of materials with less impact on the environment and on the health of people in the tread, reducing toxicity and pollution caused by wear. This feature solves a problem of an environmental and public health nature that has been aware, to a greater or lesser degree, for several decades.

Description of the drawings

The following figures show four diagrams with the characteristics of the wheel object of the invention.

Figure 1 shows a diagram of the lower section of the wheel according to a plane that contains the axis of rotation. This graphic shows the radial elements that separate the tread of the tire volume, as well as the location of the flexible covering that insulates the inner and outer walls of the carcass of the tire volume.

Figure 2 shows a diagram of the wheel according to a plane perpendicular to the axis of rotation. This graph shows the arrangement of the tire volume, the location of the rim, the radial elements and the location of the tread.

Figures 3a and 3b show two section diagrams of the wheel according to a plane that includes the axis of rotation. Figure 3a shows the area of least thickness of the carcass wall in a normal tire. In figure 3b this area of the casing wall is shown with a reinforced thickness.

Figure 4 shows a scheme according to a plane perpendicular to the axis with a mechanical anchorage of the tread band to the radial elements.

The different components that appear in the drawings are listed below:

1 - Rim.

2 - Pneumatic volume.

3 - External side wall of the pneumatic volume.

4 - Vertical axis.

5 - Surface of insulating material on the inner side of the pneumatic volume.

6 - Surface of insulating material on the outer side of the pneumatic volume.

7 - Separation zone between the walls of the tire volume and the tread.

8 - Auxiliary radial element.

9 - Tread band.

10 - Depth limit of the studs.

11 - Main radial element.

12 - Intermediate elastomer between a main radial element and an auxiliary radial element.

13 - Symmetry plane of an auxiliary radial element.

14 - Contact zone of an auxiliary radial element with an intermediate elastomer. 15 - Symmetry plane of a main radial element.

16 - Intermediate elastomer between two main radial elements.

17 - Valve.

18 - Contact area between the rim and the walls of the tire volume.

19 - Horizontal axis parallel to the axis of rotation.

20 - Inner side wall of the pneumatic volume.

21 - Inner wall of the pneumatic volume in the area furthest from the axis of rotation.

22 - Insulating coating in the inner area of the tire volume furthest from the axis of rotation.

23 - Lateral auxiliary radial element.

24 - Lateral main radial element.

25 - Structure of reinforcing wires in the wall of the pneumatic volume.

26 - Tread block

27 - Elastomer external to an auxiliary element.

28 - Contact zone between the tread band and a main radial element.

29 - Axis of rotation of the wheel.

30 - Angle of deformation of the wheel.

31 - Limit of the angle of deformation of the wheel.

32 - Zone of contact with the ground.

33 - Maximum radius of the wheel without deforming.

34 - Inner edge of the rim.

35 - Outer edge of the rim.

36 - Transition zone between the deformation angle and the zone of the undeformed tread.

37 - Lateral area of the tire volume with less thickness.

38 - Lateral zone of the pneumatic volume with increased thickness.

39 - Horizontal axis perpendicular to the axis of rotation.

40 - Gap between the main radial elements for anchoring the tread.

41 - Thickness of the main radial element in the direction of the radius.

42 - Tread thickness in the direction of the radius.

43 - Protrusions in the tread for its anchorage to the radial elements.

44 - Maximum length of the main radial element in the direction tangent to the circumference of rotation.

Description of a preferred embodiment

In Figures 1, 2, 3b and 4, various views of alternative embodiments of the invention are shown.

The preferred embodiment is described in figures 1 and 2. In it a tire volume (2) is incorporated around a standard rim (1). The tire volume is covered on its sides (3, 20) and on its central area (21) by a wall of elastomeric material, in this case it is a mixture of vulcanized natural and synthetic rubber. This wall of elastomeric material has a reinforcing structure (25) made up of intertwined metal threads on the inside. A series of main radial elements (11) made of aluminum are placed around the central area of the wall of the pneumatic volume. These main radial elements are attached, on their inside, to the wall of the pneumatic volume. Being in contact on the outside with the tread (9).

An auxiliary radial element (8) is located between each two consecutive main radial elements and the wall of the pneumatic volume. These auxiliary radial elements, also made of aluminium, are attached, on their inner face, to the wall of the pneumatic volume, the rest of their faces being covered by an elastomeric material. Likewise, it is possible to carry out the opposite arrangement, joining the radial elements on their outer face to the tread band, their other faces being covered by an elastomeric material.

This alternating distribution between main radial elements, intermediate elastomers and auxiliary radial elements occurs both in the horizontal direction (39) perpendicular to the axis of rotation, and in the direction (19) parallel to this axis.

The union of the radial elements to the casing is carried out during the manufacturing process, incorporating them before the vulcanization process, generating a highly resistant metal-rubber union.

Likewise, the aluminum material of the radial elements, as well as their alternate arrangement, prevents the presence of a sharp object on the roadway from reaching the wall of the tire volume, thus preventing a puncture from this cause.

On the other hand, the thickness of the tread band (42), according to the direction of the radius, is greater than 50% of the length (44) of a main radial element (11), according to the direction tangent to the circumference. This proportion allows the torsion that occurs in the main radial elements in the transition zone (36) between the contact zone with the ground (32) and the rest of the wheel, to be absorbed by the elastomer that constitutes the tread band. tread.

The thickness of the radial elements according to the direction of the radius (41) must be as small as possible (in the order of millimeters) in order to reduce the weight and the moment of inertia, while maintaining a sufficient resistance to puncture.

The incorporation of the tread into the carcass in this embodiment is effected by mechanical means. To make this union, it is necessary to previously deflate the tire volume to facilitate the fit of the ring formed by the tread in the outer area of the radial elements. As can be seen in figure 4, the tread has projections (43), which fit into recesses (40) that are located in the main radial elements (11). Once the fit has been made, the pneumatic volume is inflated again up to its operating pressure, producing the grip of both elements.

In relation to the material that makes up the tread, a biodegradable rubber is chosen, or else a mixture of a non-biodegradable rubber that has interstitial holes in which blocks of a biodegradable material are incorporated, such as cork, in the area of contact with the ground.

The casing that surrounds the tire volume and is incorporated into the rim is made from a mixture of natural and synthetic rubber, or another similar elastomer, to which interior reinforcement materials such as metallic threads, polyester or Kevlar are incorporated. For its hardening and acquisition of resistance and elastic characteristics, a vulcanization process is carried out in the presence of sulfur, at temperature and pressure, in a similar way to current tires.

Once the vulcanization process has been carried out and the casing has cooled, an insulating material (5, 22) is applied to its interior part, which is not permeable to diatomic oxygen or ozone present in the pressurized pneumatic volume. This material has a degree of flexibility and elasticity equal to or greater than that of the vulcanized rubber on the inside of the carcass.

The insulating material (6) is applied to the outside, which is not permeable to diatomic oxygen or ozone present in the atmosphere and also has a degree of flexibility and elasticity equal to or greater than that of the vulcanized rubber on the outside of the shell. Case.

Additionally, figure 3b shows another alternative embodiment in which the thickness (38) of the side walls of the tire volume has been increased by the area in which they usually have less width (37). As previously mentioned, this increase in thickness can delay the degradation by oxidation of the vulcanized rubber in the area most likely to affect the operability of the wheel.

Thus, these embodiments meet the objectives of the invention, namely:

The prolongation of the useful life of the tire reducing the problem of the degradation of the vulcanized rubber due to its oxidation.

The use of materials in the tread with less impact on the environment and on people's health, reducing toxicity and pollution caused by wear.

Increased vehicle safety by incorporating puncture-resistant intermediate radial elements that protect the tire volume.

These three objectives solve some challenges that have been known for several decades and to which an adequate response has not been achieved with other alternative designs.

Claims (16)

1. Wheel, which has a pneumatic volume (2) surrounded by a wall (3, 20, 21) containing vulcanized elastomeric material, which is in contact with a rim (1), which has a tread (9 ), and which is characterized by : a) comprises an insulating surface (5) in contact with the inner wall (20, 21) of the pneumatic volume (2), such that: a1) the inner insulating surface (5) is made of a flexible material; a2) the flexible material of the inner insulating surface (5) has a degree of flexibility equal to or greater than that of the elastomeric material of the inner wall (20, 21) of the pneumatic volume (2); a3) the flexible material of the inner insulating surface (5) is not porous to diatomic oxygen and ozone existing in the volume under pressure; a4) the flexible material of the inner insulating surface (5) is also elastic; a5) the flexible and elastic material of the inner insulating surface (5) has a degree of elasticity equal to or greater than that of the elastomeric material of the inner wall (20, 21) of the pneumatic volume (2); a6) the insulating surface (5) is incorporated into the inner wall (20, 21) after the vulcanization process of the elastomeric material of this inner wall that surrounds the tire volume (2); a7) The insulating surface (5) is incorporated into the inner wall (20, 21) by adhering both surfaces according to one of the following alternatives: a7a) the material of the interior insulating surface (5), in addition to the characteristics included in a1, a2, a3, a4, a5, and a6, has the ability to adhere to the elastomeric material of the interior wall (20, 21) of the tire volume (2); a7b) the material of the inner insulating surface (5), has the characteristics listed in a1, a2, a3, a4, a5, and a6 but does not have the ability to adhere to the elastomeric material and an adhesive material with the ability to bonding to the rubber to unite both surfaces; b) comprises an insulating surface (6) in contact with the outer wall (3) of the pneumatic volume (2), so that: b1) the outer insulating surface (6) is made of a flexible material; b2) the flexible material of the outer insulating surface (6) has a degree of flexibility equal to or greater than that of the elastomeric material of the outer wall (3) of the pneumatic volume (2); b3) the flexible material of the outer insulating surface (6) is not porous to diatomic oxygen and ozone existing in the atmosphere; b4) the flexible material of the insulating surface (6) is also elastic; b5) the flexible and elastic material of the outer insulating surface (d) has a degree of elasticity equal to or greater than that of the elastomeric material of the outer wall (3) of the tire volume (2); b6) the insulating surface (6) is incorporated into the outer wall (3) after the vulcanization process of the elastomeric material of this outer wall that surrounds the tire volume (2); b7) The insulating surface (6) is incorporated into the outer wall (3) by adhering both surfaces according to one of the following alternatives: b7a) the material of the insulating surface (6), in addition to the characteristics included in b1, b2, b3, b4, b5 and b6, has the ability to adhere to the elastomeric material; b7b) the material of the insulating surface (6), has the characteristics listed in b1, b2, b3, b4, b5 and b6, but it does not have the ability to adhere to vulcanized rubber and an adhesive material with bonding capacity is used to the rubber to unite both surfaces. 2. Wheel according to claim 1 , characterized in that the material with which the insulating, flexible and elastic surface is made is biodegradable. 3. Wheel according to claims 1 or 2 , characterized in that it incorporates a set of intermediate radial elements (8, 11, 23, 24) located between the wall of the tire volume furthest from the axis of rotation (29) and the tread ( 9). 4. Wheel according to claim 3 , characterized in that the intermediate radial elements are divided into main and secondary elements such that: a) the main radial elements (11, 24) are in contact with the wall of the tire volume and with the tread (9); b) The auxiliary radial elements (8, 23) are in contact with the wall of the tire volume or with the tread band (9), but they are not in contact with both elements. Wheel according to claim 3 or 4 , characterized in that the intermediate radial elements (8, 11, 23, 24) are made of a puncture-resistant material. 6. Wheel according to claims 3, 4 or 5 , characterized in that the intermediate radial elements (8, 11, 23, 24) are arranged alternately, preventing any sharp object that pierces the tread from reaching the wall of the tire volume. . Wheel according to claims 3, 4, 5 or 6 , characterized in that the tread is made of a material other than the vulcanized elastomeric material constituting the carcass that surrounds the tire volume. 8. Wheel according to claim 7 , characterized in that the tread is made of a biodegradable material. 9. Wheel according to claim 7 , characterized in that the tread is made up of a non-biodegradable material that has interstitial cavities in which elements of a biodegradable material are incorporated, in the areas in contact with the ground. Wheel according to claims 3, 4, 5, 6, 7, 8 or 9 , characterized in that the radial elements have recesses (40) in their area of contact with the tread. Wheel according to claims 3, 4, 5, 6, 7, 8, 9 or 10 , characterized in that the tread has projections (43) in its area of contact with the radial elements. 12. Wheel according to claims 10 or 11 , characterized in that the projections (43) of the tread and the recesses (40) of the radial elements are arranged in such a way that the former can fit inside the latter, producing the fixation of the tread band to the radial elements once the tire volume is inflated to its operating pressure. Wheel according to claims 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12 , characterized in that the thickness (42) of the tread in the direction of the radius (4) is greater than 50 % of the length (44) of the main radial elements measured in the direction tangent to the circumference of rotation. Wheel according to claims 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 or 13 , characterized in that the union of the main radial elements (11) to the walls (3, 20, 21) of the tire volume (2) is done by incorporating it during the vulcanization process of the carcass. Wheel according to claims 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 or 14 , characterized in that the thickness (41) of the main radial elements in the direction of the radius is less than 1cm. Wheel according to any of the preceding claims , characterized in that the side walls (3, 20) of the tire volume have a rubber thickness greater than that of a traditional tire of similar dimensions.