ALARM METHOD FOR INDICATING THE WEAR OF A TYRE WITH A GROOVE

• US 20110252862A1
• Filed: 12/21/2009
• Published: 10/20/2011
• Est. Priority Date: 12/23/2008
• Status: Active Grant

• Current Assignee: Compagnie générale des établissements Michelin
• Original Assignee: Michelin Recherche et Technique SA (Compagnie Generale DES Etablissements Michelin SCA), Societe De Technologie Michelin (Compagnie Generale DES Etablissements Michelin SCA)
• Inventors: Paturle, Antoine
• Granted Patent: US 8,904,869 B2
• Time in Patent Office: Days
• US Class Current: 73/8
• CPC Class Codes: B60C 11/24 Wear-indicating arrangements

Abstract

In a method for alerting to the wear of a tyre that includes a tread strip equipped with at least one circumferential groove,

• • the running noise made by the tyre running along a ground is measured,
  • from the measured running noise, a noise emitted in a predetermined range of frequencies close to a predetermined resonant frequency of a portion of the circumferential groove during running is isolated,
  • the amplitude of the isolated noise is measured, and
  • the measured amplitude is compared against a predetermined alert threshold.

Claims

1-8. -8. (canceled)

9. A method for alerting to wear of a tyre that includes a tread strip equipped with at least one circumferential groove, the method comprising steps of:

measuring a running noise made by the tyre running along a ground;

from the measured running noise, isolating a noise emitted in a predetermined range of frequencies close to a predetermined resonant frequency of a portion of the circumferential groove during running;

measuring an amplitude of the isolated noise; and

comparing the measured amplitude against a predetermined alert threshold.

10. A method according to claim 9, wherein the predetermined resonant frequency corresponds to a frequency caused by a portion of the circumferential groove of a length substantially equal to a length of a contact patch via which the tyre is in contact with the ground.

11. A method according to claim 10, wherein the predetermined frequency is substantially equal to C/2.L, where C is a speed at which sound travels through air and L is the length of the contact patch.

12. A method according to claim 9, wherein the predetermined alert threshold is dependent on a mean value of the running noise of the tyre running along the ground.

13. A method according to claim 9, wherein the tyre when in new condition includes a circumferential groove, and a tyre wear alert is triggered when a measured amplitude of resonance of the circumferential groove is below the predetermined alert threshold.

14. A method according to claim 9, wherein the tyre when in new condition includes a circumferential channel embedded in the tread strip, the circumferential channel forming a circumferential groove when the tyre becomes worn, and a tyre wear alert is triggered when a measured amplitude of resonance of the circumferential groove is above the predetermined alert threshold.

15. A method according to claim 14, wherein the circumferential channel has a cross-section area of at least 25 mm².

16. A method according to claim 9,

wherein, in the step of measuring the amplitude of the isolated noise, at least two spikes of different frequencies corresponding to resonance noises of at least two circumferential grooves that are axially offset from a median plane of the tyre are isolated from the running noise in the predetermined range of frequencies, and

wherein, in the step of comparing, relative amplitudes of the at least two spikes are compared.