Tire with Belt Package Reinforcement Element

Abstract

Tyre comprising a carcass, a belt package and a tread; said tyre comprising at least a reinforcement net made of a weaved textile material having a number of meshes ranging from 3 to 20, and wherein the threads are oriented between 25° and 65° relative to a longitudinal axis (X) of the tyre; said reinforcement net being arranged at least in the area of a centre of the tread and positioned inside the belt package or between the belt package and the tread; said weaved textile material having an elongation at break equal to or greater than 10%; said reinforcement net having a shorter transverse extension than the one of the belt package.

Claims

1-8. (canceled)

9. A tire comprising: a carcass; a belt package; a tread; a reinforcement net comprising a weaved textile material having a number of meshes ranging from 3 to 20, and wherein threads thereof are oriented between 25° and 65° relative to a longitudinal axis of the tire; wherein the reinforcement net is arranged in a central area of the tread and positioned inside the belt package or between the belt package and the tread; wherein the weaved textile material has an elongation at break equal to or greater than 10%; and wherein the reinforcement net has a shorter transverse extension than a transverse extension of the belt package.

10. The tire of claim 9, wherein the reinforcement net is arranged proximate a central rib of the tread.

11. The tire of claim 9, wherein the reinforcement net comprising a weaved textile material has a number of meshes ranging from 8 to 16.

12. The tire of claim 10, wherein the reinforcement net comprising a weaved textile material has a number of meshes ranging from 12 to 16.

13. The tire of claim 9, wherein the reinforcement net comprises a weaved textile material with an elongation at break equal to or greater than 15%.

14. The tire of claim 9, wherein the reinforcement net comprises a weaved textile material with an elongation at break equal to or greater than 20%.

15. The tire of claim 9, wherein the reinforcement net is made of Nylon.

16. The tire of claim 9, wherein the belt package comprises at least a pair of steel belts and the reinforcement net is positioned on a steel belt of the pair of steel belts that is closest to the tread.

17. The tire of claim 9, wherein the belt package comprises at least a pair of steel belts and a cap ply, and the reinforcement net is positioned between a steel belt of the pair of steel belts that is closest to the tread and the cap ply.

18. The tire of claim 9, wherein the reinforcement net is covered with an adhesive substance configured to guarantee adhesion between the reinforcement net and a surrounding rubber.

Description

[0021] The FIGURE shows a portion of a tire according to the invention with parts removed for greater clarity.

[0022] In the FIGURE, number 1 indicates, as a whole, a tire comprising a carcass 2, a belt package 3 and a tread 4. In particular, the belt package 3 comprises a pair of steel belts 5a and 5b and a cap ply 6.

[0023] The tire 1 comprises a reinforcement net 7 arranged between the second steel belt 5b and the cap ply 6.

[0024] The reinforcement net 7 has a smaller transverse extension than the one of the belt package and is arranged in the area of a central rib 8 of the tread 4.

[0025] The reinforcement net 7 is made of Nylon and has threads oriented at 45° relative to a longitudinal axis X of the tire. Nylon has an elongation at break of 20%.

[0026] In particular, the reinforcement net 7 has a number of mesh of 12, a width of 100 mm, a gauge of 0.6 mm and threads of 6.6 Nylon characterized by 940 dtex and EPDM 47.

[0027] The reinforcement net before being mounted on the tire was covered with RFL resin as adhesive substance, in order to guarantee the adhesion of the net with surrounding rubber.

[0028] The tire 1 comprising the reinforcement net 7 was subjected to the plunger test according to FMVSS 139 American standard under Extra load tire condition with tire 195/55R16.

[0029] For comparison, the same test was performed on a comparison tire, which differs from the tire of the invention solely because it is devoid of the reinforcing net 7.

[0030] The plunger test showed for the tire of the present invention an energy higher than that found for the comparison tire.

[0031] In particular, indexing the energy value obtained with the comparison tire(without reinforcement net) to 100, the energy value obtained with the tire of the invention amounts to 123.

[0032] The energy increase obtained with the tire of the invention derives from the resistance produced by the reinforcement net per se only to a minimum extent (14% of the total improvement from the comparison tire), whereas, to a much greater extent, it derives from the effect, generated by the reinforcement net itself, of dissipation of the load on the steel belts.

[0033] Obviously, the above dissipation is possible only if the weaved textile material has an elongation at break such as to be flexible enough to spread external input on wider steel cord area. In fact, if the weaved textile material breaks (low elongation break) it will not be able to have enough spreading effect.

[0034] In order to demonstrate that the elongation at break of weaved textile materials plays an essential role for the effectiveness of the invention, the inventors made a comparison between reinforcement nets made of Nylon and reinforcement nets made of a Nylon/Aramid hybrid.

[0035] The elongation at break of Nylon/Aramid hybrid is 4.5%.

[0036] The comparison has been carried out by FEM Simulation using the following conditions: [0037] Net strip width:25 mm [0038] Net strip gauge:0.6 mm [0039] Net angle: 2strip×45° [0040] Fabric type: [0041] Nylon(1400/2) at different EPDM: 100,47,13 with E (Modulus)=3.544×10.sup.5 psi [0042] Hybrid (Aramid: 1670/2 +Nylon: 940/1) at different EPDM: 100,47,13 with E (Modulus)=2.5×10.sup.6 psi [0043] Tire size: 195/65R15 [0044] Rubber skim modulus: E(modulus)=8.261×10.sup.2 psi, Poisson ratio:0.4950 [0045] Rubber Tread Modulus: E(modulus)=8.657×10.sup.2 psi, Poisson ratio:0.4950

[0046] In Table I plunger simulation data (FEM simulation) are shown.

[0047] The results of table I are indexed to the tire without reinforcement net.

TABLE-US-00001 TABLE I Tire without reinforcement net   100% Tire with Nylon reinforcement net (3 Mesh) 109.8% Tire with Nylon reinforcement net (12 Mesh) 112.6% Tire with Hybrid reinforcement net (3 Mesh) 107.6% Tire with Hybrid reinforcement net (12 Mesh) 110.5%

[0048] Owing to the above, it is evident that the solution suggested by this invention can ensure an improvement of the tire in terms of higher energy values in the plunger test.

[0049] This result is necessarily associated with a greater resistance of the belt package of the tire, which automatically translates into a longer life thereof.