Method and apparatus for controlling tyres in a tyre production line

Patent metadata

Field	Value
Publication number	US-9719944-B2
Application number	US-201414902464-A
Country	US
Kind code	B2
Filing date	Jul 7, 2014
Priority date	Jul 10, 2013
Publication date	Aug 1, 2017
Grant date	Aug 1, 2017

Abstract

A method, and related apparatus, for controlling tyres in a production line, includes: predisposing a tyre to be controlled; elastically deforming a lateral wall portion of the tyre by imparting a compression force on an outer contact surface of the lateral wall portion, the compression force having axial direction and sense directed toward the middle line plane; illuminating an inner and/or outer surface of the lateral wall portion and detecting an image of the illuminated surface; generating a control signal representative of the detected image; and analyzing the control signal in order to detect the possible presence of flaws on the lateral wall portion.

First claim

The invention claimed is:

1. A method for controlling tyres in a tyre production line, comprising:
predisposing a tyre to be controlled, the tyre having a rotation axis and a middle line plane orthogonal to the rotation axis;
elastically deforming a portion of a lateral wall of said tyre by imparting, through physical contact, a force of compression on an outer contact surface belonging to said lateral wall portion, said compression force having at least one component parallel to the rotation axis and sense directed toward the middle line plane;
illuminating, with a light radiation, one surface of said lateral wall portion and detecting an image of said illuminated surface;
generating at least one control signal representative of the detected image; and
analysing said at least one control signal in order to detect a possible presence of flaws on the lateral wall portion.

2. The method as claimed in claim 1 , wherein said analysis comprises at least a comparison of said at least one control signal with at least one corresponding reference signal.

3. The method as claimed in claim 2 , wherein an alarm signal is generated following said comparison if said control signal differs from said reference signal by more than a predefined threshold level.

4. The method as claimed in claim 2 , wherein the reference signal is generated by previously controlling a model tyre.

5. The method as claimed in claim 2 , wherein the reference signal is generated during control of said tyre by illuminating portions homologous to a portion of said tyre subjected to control and generating said reference signal as an average of signals obtained from each image of each homologous portion.

6. The method as claimed in claim 2 , wherein the reference signal is generated during control of said tyre by means of an average of control signals obtained on n homologous portions preceding the elastically deformed portion, wherein n is greater than or equal to one.

7. The method as claimed in claim 1 , wherein a bead of the tyre to be controlled is locked.

8. The method as claimed in claim 1 , wherein the pressure inside the tyre to be controlled is equal to the outside pressure, one bead of the tyre to be controlled remaining free.

9. The method as claimed in claim 1 , comprising elastically deforming said lateral wall portion in order to flatten an inner and/or outer surface of at least one sub-portion of the deformed lateral wall portion.

10. The method as claimed in claim 1 , wherein the outer contact surface belongs to a shoulder or to a radially central portion of the lateral wall.

11. The method as claimed in claim 9 , wherein the flattened inner surface of said sub-portion is illuminated in order to detect an image thereof, said illuminated inner surface being situated on a side opposite said outer contact surface.

12. The method as claimed in claim 9 , wherein the flattened outer surface of said sub-portion is illuminated in order to detect an image thereof, said illuminated outer surface being situated in a position adjacent to said outer contact surface, with reference to a circular extension direction of the lateral wall.

13. The method as claimed in claim 1 , comprising elastically deforming said lateral wall portion in order to decrease an external radius of curvature of at least one sub-portion of said lateral wall portion.

14. The method as claimed in claim 13 , wherein an outer surface of said at least one sub-portion is illuminated in order to detect the image thereof, and said illuminated outer surface is situated in a radially more external position with respect to said outer contact surface.

15. The method as claimed in claim 13 , wherein the outer contact surface belongs to a radially central portion of the lateral wall and said sub-portion is situated at the respective shoulder.

16. The method as claimed in claim 13 , wherein the outer contact surface is close to the bead and said sub-portion belongs to a radially central portion of the lateral wall.

17. The method as claimed in claim 1 , wherein the compression force is parallel to the rotation axis.

18. The method as claimed in claim 1 , comprising providing deforming said lateral wall portion, maintaining at least one further portion of the lateral wall non-deformed.

19. The method as claimed in claim 1 , wherein the compression force is such to deform said lateral wall portion in a manner such that a maximum travel, taken from among all points of said lateral wall portion, between a position without forces and the deformed position, the travel being taken along a direction of the compression force, is greater than or equal to approximately 0.5 cm and less than or equal to approximately 5 cm.

20. The method as claimed in claim 1 , wherein said compression force is, in modulus, greater than or equal to approximately 40 N and less than or equal to approximately 80 N.

21. The method as claimed in claim 1 , comprising repeating the deforming, illuminating, detecting an image, generating and analysing a control signal in time sequence on a plurality of further portions of a lateral wall beside said lateral wall portion, said plurality being distributed along a circular extension of the lateral wall, wherein said plurality of further portions of the lateral wall are continuous with each other and constitute, with said lateral wall portion, an entire lateral wall.

22. The method as claimed in claim 21 , wherein the compression force is maintained constant.

23. The method as claimed in claim 1 , comprising, subsequent to elastically deforming said lateral wall portion and before detecting the image, rotating the tyre around an axis thereof by at least half a revolution, maintaining said compression force.

24. The method as claimed in claim 1 , comprising imparting said compression force by pressing a cylindrical compression roller against said outer contact surface, the roller being able to freely rotate around an axis thereof.

25. The method as claimed in claim 1 , comprising controlling a plurality n of tyres in a predefined time interval, said time interval corresponding to n times a cycle time of said production line.

26. The method as claimed in claim 25 , comprising, in a same predefined time interval, maintaining k tyres in the production line, with k=<n, and sending n-k tyres outside said production line, as a function of the control signal.

27. The method as claimed in claim 26 , wherein each of said n-k tyres sent outside the production line is sent to a check station for carrying out at least one further test on a same tyre.

28. An apparatus for controlling tyres in a tyre production line, comprising:
a movement member having a support adapted to rotate the tyre around a rotation axis thereof;
a deformation system configured for imparting, through physical contact, a compression force on an outer contact surface belonging to a portion of a lateral wall of said tyre, when said tyre is supported by the support, in order to elastically deform said lateral wall portion, said compression force having at least one component parallel to the rotation axis and sense directed toward a middle line plane of the tyre;
a source adapted to emit a light radiation for illuminating a surface of said lateral wall portion and a detection system adapted to detect an image of said surface, and to generate at least one control signal representati

Assignees

• Pirelli

Inventors

• Boffa Vincenzo
• Ballardini Valeriano
• Pece Gabriele

Classifications

• G01N2021/8887

  based on image processing techniques · CPC title

• G01N21/952

  Inspecting the exterior surface of cylindrical bodies or wires (G01N21/956 takes precedence) · CPC title

• G01N21/954 Primary

  Inspecting the inner surface of hollow bodies, e.g. bores · CPC title

• G01M17/027

  using light, e.g. infrared, ultraviolet or holographic techniques · CPC title

• G01N21/95

  characterised by the material or shape of the object to be examined (G01N21/89 - G01N21/91, G01N21/94 take precedence) · CPC title