SYSTEM FOR MEASURING THE THICKNESS OF A LINER LAYER OF A TIRE

• US 20160161243A1
• Filed: 07/25/2014
• Published: 06/09/2016
• Est. Priority Date: 07/26/2013
• Status: Active Grant

• Current Assignee: Compagnie générale des établissements Michelin
• Original Assignee: Compagnie générale des établissements Michelin, Michelin Recherche et Technique SA (Compagnie Generale DES Etablissements Michelin SCA)
• Inventors: Ledoux, Thomas, MICHAUD, Gr?gory, Martin, Denis, Meneroud, Patrick
• Granted Patent: US 10,876,826 B2
• Time in Patent Office: Days
• CPC Class Codes: G01B 7/06 for measuring thickness measuring during the manufacture of coatings C23C14/54
• CPC Class Codes: G01B 7/14 for measuring distance or clearance between spaced objects or spaced apertures G01B7/30 takes precedence
• CPC Class Codes: G01B 7/26 for measuring depth
• CPC Class Codes: G01M 17/02 Tyres
• CPC Class Codes: G01N 27/82 for investigating the presence of flaws
• CPC Class Codes: G01R 33/12 Measuring magnetic properties of articles or specimens of solids or fluids involving magnetic resonance G01R33/20

Abstract

A system is provided for measuring a thickness of rubber layer of a tire. The layer includes a joined face, which is joined to an adjacent metal reinforcement, and a free face in contact with air. The system includes a casing with an application face for contacting the free face, and a sensor positioned in the casing and structured to measure a distance d between the joined face and the free face. The sensor includes a source coil and an adjacent sensing element. The source coil is a source of an alternating magnetic field. The sensing element includes a sensing device configured to produce an output signal that is dependent on an induced local magnetic field. An excitation power and a frequency of the source coil are such that the local magnetic field induced between the reinforcement and the source coil increases in strength as the distance d decreases.

Claims

1-28. -28. (canceled)

29. A measurement system for measuring a thickness of a layer of rubber material of a tire, the layer including a joined face, which is joined to an adjacent reinforcement formed of at least one material having a magnetic permeability greater than a magnetic permeability of air, and a free face in contact with air, the system comprising:

a casing structured to include an application face for contacting the free face of the layer; and

a sensor positioned in the casing and arranged to measure a distance d between the joined face and the free face of the layer, the sensor including;

a source coil element, which is a source of an alternating magnetic field, and

a sensing element positioned adjacent the source coil element, the sensing element including a sensitive sensor structured to produce an output signal that is dependent on a magnitude of a local magnetic field induced between the reinforcement and the source coil element,

wherein an excitation power and a frequency of the source coil element are such that the local magnetic field induced between the reinforcement and the source coil element increases in strength as the distance d decreases.

30. The measurement system according to claim 29, wherein the sensitive sensor is a Hall-effect sensor or a magnetoresistive sensor.

31. The measurement system according to claim 29, wherein the sensing element is positioned between the source coil element and the application face of the casing.

32. The measurement system according to claim 29, wherein the source coil element is positioned between the sensing element and the application face of the casing.

33. The measurement system according to claim 29, wherein the sensing element and the source coil element are adjacent and substantially a same distance from the application face of the casing.

34. The measurement system according to claim 29, wherein the source coil element is positioned around, or is surrounded by, a material having high electrical resistivity and high magnetic permeability.

35. The measurement system according to claim 34, wherein the sensitive sensor is positioned at an end of a branch of the material having high electrical resistivity and high magnetic permeability.

36. The measurement system according to claim 34, wherein the material having high electrical resistivity and high magnetic permeability is U-shaped.

37. The measurement system according to claim 34, wherein the material having high electrical resistivity and high magnetic permeability is E-shaped.

38. The measurement system according to claim 37, wherein the sensing element includes two sensitive sensors, each sensitive sensor being positioned respectively at an end of an outer pole of the material having high electrical resistivity and high magnetic permeability.

39. The measurement system according to claim 34, wherein the material having high electrical resistivity and high magnetic permeability has an axis of symmetry and is E-shaped when viewed in any axial section.

40. The measurement system according to claim 39, wherein the sensing element is positioned at an end of a central axis of the material having high electrical resistivity and high magnetic permeability.

41. The measurement system according to claim 37, wherein the source coil element is positioned around a central bar of the material having high electrical resistivity and high magnetic permeability.

42. The measurement system according to claim 34, wherein the material having high electrical resistivity and high magnetic permeability is an H-shaped material.

43. The measurement system according to claim 42, wherein the source coil element is positioned around a central bar of the H-shaped material.

44. The measurement system according to claim 42, wherein the source coil element includes two excitation coils, each of the two coils being positioned around a lateral branch of the H-shaped material, respectively, with one coil positioned on each side of a central branch of the H-shaped material being preferable.

45. The measurement system according to claim 42, wherein the source coil element includes four excitation coils, each of the four coils being positioned around half a lateral branch of the H-shaped material, respectively.

46. The measurement system according to claim 42, wherein the sensing element includes two sensitive sensors positioned around a same lateral branch of the H-shaped material, with one sensitive sensor being positioned on each side of a central branch of the H-shaped material.

47. The measurement system according to claim 42, wherein the sensing element includes two sensitive sensors separately positioned on a distinct lateral branch of the H-shaped material, respectively, with one sensitive sensor being positioned on each side of a central branch of the H-shaped material.

48. The measurement system according to claim 42, wherein the sensing element includes four sensitive sensors, each of the four sensitive sensors being positioned on half a lateral branch of the H-shaped material, respectively.

49. The measurement system according to claim 29, wherein the source coil element is supplied with an alternating electrical current or a voltage having a frequency below 500 kHz.

50. The measurement system according to claim 49, wherein the source coil element is supplied with an alternating electrical current or a voltage having a frequency higher than 10 kHz.

51. The measurement system according to claim 50, wherein the source coil element is supplied with an alternating electrical current or a voltage having a frequency in a range from 40 kHz to 80 kHz.

52. The measurement system according to claim 29, wherein

the casing is electrically non-conductive and has magnetic properties similar to those of air, and

the application face of the casing is parallel or normal to an axis of sensitivity of the source coil element.

53. The measurement system according to claim 29, wherein the casing is a portable casing.

54. The measurement system according to claim 29, wherein the casing is structured to be positioned on or embedded in a roadway.

55. A method for measuring a thickness of a remaining layer of rubber material on a tread of a tire, the layer including a joined face, which is joined to an adjacent reinforcement made with at least one material having a magnetic permeability greater than a magnetic permeability of air, and a free face in contact with air, the system comprising:

a casing structured to include an application face for contacting the free face of the layer; and

a sensor positioned in the casing and arranged to measure a distance d between the joined face and the free face of the layer, the sensor including;

a source coil element, which is a source of an alternating magnetic field, and

a sensing element positioned adjacent the source coil element, the sensing element including a sensitive sensor structured to produce an output signal that is dependent on a magnitude of a local magnetic field induced between the reinforcement and the source coil element,

wherein an excitation power and a frequency of the source coil element are such that the local magnetic field induced between the reinforcement and the source coil element increases in strength as the distance d decreases.

56. A method for measuring a thickness of a layer of rubber material of a sidewall or an inner liner of a tire, the layer including a joined face, which is joined to an adjacent reinforcement made with at least one material having a magnetic permeability greater than a magnetic permeability of air, and a free face in contact with the air, the system comprising:

a casing structured to include an application face for contacting the free face of the layer; and

a sensor positioned in the casing and arranged to measure a distance d between the joined face and the free face of the layer, the sensor including;

a source coil element, which is a source of an alternating magnetic field, and

a sensing element positioned adjacent the source coil element, the sensing element including a sensitive sensor structured to produce an output signal that is dependent on a magnitude of a local magnetic field induced between the reinforcement and the source coil element,

wherein an excitation power and a frequency of the source coil element are such that the local magnetic field induced between the reinforcement and the source coil element increases in strength as the distance d decreases.