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EP-4741792-A1 - TESTING APPARATUS FOR ESTIMATING PARAMETERS CORRELATED TO THE INTERACTION BETWEEN A TYRE AND A SURFACE

EP4741792A1EP 4741792 A1EP4741792 A1EP 4741792A1EP-4741792-A1

Abstract

A testing apparatus (10) for estimating parameters correlated to the interaction between a tyre and a surface. The testing apparatus (10) comprises an annular drum (20) rotatable about a drum rotation axis (X) and having a radially inner surface (21), a first driving device (30) configured to drive in rotation the annular drum (20) about the drum rotation axis (X), a tyre test sample (100) arranged on said radially inner surface (21) and a second driving device (40) configured to drive in rotation the tyre test sample (100) on the radially inner surface (21) of the annular drum (20) under controlled running conditions. The first driving device (30) has a rotation axis (Y) extending in a radially outer position with respect to the annular drum (20), so as to be able to access the annular drum (20) from the opposite side thereof.

Inventors

  • KLING, Konstantin Peter

Assignees

  • Pirelli Tyre S.p.A.

Dates

Publication Date
20260513
Application Date
20241111

Claims (15)

  1. Testing apparatus (10) for estimating parameters correlated to the interaction between a tyre and a surface, comprising: - an annular drum (20) rotatable about a drum rotation axis (X) and having a radially inner surface (21); - a first driving device (30) configured to drive in rotation the annular drum (20) about the drum rotation axis (X), the first driving device (30) having a rotation axis (Y) extending in a radially outer position with respect to the annular drum (20); - a tyre test sample (100) arranged on said radially inner surface (21); - a second driving device (40) configured to drive in rotation the tyre test sample (100) on said radially inner surface (21) under controlled running conditions.
  2. Testing apparatus (10) according to claim 1, wherein the first driving device (30) rotates about its rotation axis (Y) in a rotation direction opposite the rotation direction of the annular drum (20) about the drum rotation axis (X).
  3. Testing apparatus (10) according to claim 1 or 2, wherein the annular drum (20) comprises, on the radially inner surface (21) thereof, an annular track (22) made of an abrasive material and the tyre test sample (100) is arranged on said annular track (22).
  4. Testing apparatus (10) according to any one of the previous claims, comprising a hexapod (150) connected to the second driving device (40).
  5. Testing apparatus (10) according to any one of the previous claims, wherein the first driving device (30) comprises, on a radially outer surface (33) thereof, a first annular gear (38) and the annular drum (20) comprises, on a radially outer surface (23) thereof, a second annular gear (28), the first annular gear (38) and the second annular gear (28) being mutually engaged.
  6. Testing apparatus (10) according to any one of the previous claims, comprising a first rolling bearing (50) in contact with a radially outer surface (23) of the annular drum (20) and having a rotation axis (Z) extending in a radially outer position with respect to the annular drum (20).
  7. Testing apparatus (10) according to claim 6, wherein the first rolling bearing (50) comprises first axially opposed shoulders (51a, 51b) in abutment against opposed axial surfaces (24a, 24b) of the annular drum (20).
  8. Testing apparatus (10) according to claim 6 or 7, comprising a second rolling bearing (60) in contact with the radially outer surface (23) of the annular drum (20), the second rolling bearing (60) being arranged on the opposite side of the first rolling bearing (50) with respect to the annular drum (20) and having a rotation axis (W) extending in a radially outer position with respect to the annular drum (20).
  9. Testing apparatus (10) according to claim 8, wherein the second rolling bearing (60) comprises second axially opposed shoulders (61a, 61b) in abutment against opposed axial surfaces (24a, 24b) of the annular drum (20).
  10. Testing apparatus (10) according to any one of the previous claims, wherein the annular drum (20) comprises axially opposed annular shoulders (25a, 25b) projecting toward the drum rotation axis (X) and wherein the radially inner surface (21) of the annular drum (20) is arranged between the axially opposed annular shoulders (25a, 25b).
  11. Testing apparatus (10) according to any one of the previous claims, comprising an abutment wheel (70) in contact with a lowermost portion (21*) of the radially inner surface (21) of the annular drum (20).
  12. Testing apparatus (10) according to any one of the previous claims, comprising at least one further device (80) arranged in a radially inner position of the annular drum (20).
  13. Testing apparatus (10) according to any one of the previous claims, comprising a camera (90).
  14. Testing apparatus (10) according to any one of the previous claims, comprising an outer case (200).
  15. Testing apparatus (10) according to claim 14, comprising at least one additional device (300) configured to provide a controlled climate inside the enclosed outer case (200).

Description

The present invention relates to a testing apparatus for estimating parameters correlated to the interaction between a tyre and a surface. The testing apparatus of the invention is intended to be used in laboratories or plants of tyre manufacturers and/or suppliers of compound recipes for tyres. Tyres manufacturers or the abovementioned suppliers typically perform tests where real road surface conditions and real driving conditions are simulated in order to evaluate the behavior of tyres or of chemical compounds for tyres under such simulated real conditions. Critical parameters such as traction, wear, rolling resistance, noise etc. are evaluated during the tests or afterwards by proper sensors and suitable data acquisition systems. These tests are very helpful in tyre research and development as they finally allow manufacturers to evaluate tyre longevity and performance and optimize tyre design, so as to meet high safety and quality standards. More generally, the testing apparatus of the invention can be used by anyone involved in testing the interaction between a material/tyre and a surface, thus also by legal testing institutes or departments, universities, or independent testing facilities, for example in the context of the Euro 7 standard which sets new emission regulations for vehicles in the European Union. PRIOR ART Different types of tyre testing apparatus are known. Some known tyre testing apparatuses are configured to perform tests on full-scale tyres. Other known tyre testing apparatus are configured to perform tests on small-scale tyres or rubber-like specimens. An example of testing apparatus configured to carry out tests on full-scale tyres is described in DE102020213795A1. This apparatus comprises a rotatable drum having an inner surface on which eight track segments are detachably fastened. The inner faces of the track segments form a rolling surface where a tyre is made to rotate. Seven of the eight track segments are road segments with a conventional asphalt coating on their inner faces. Alternatively, the track segments can be made of aluminum and their inner faces are provided with abrasive elements in order to obtain an asphalt roadway. The tyre is mounted on a wheel support which can be subjected to different forces and can be set to different slip angles during the test. Different loads can be applied to the wheel support to simulate vehicles having different weights. DE2611123B1 describes different embodiments of a testing apparatus configured to carry out wear tests on test pieces consisting on miniature tyres or rubber-like specimens. In a first embodiment, the test piece is made to rotate on the outer surface of a rotatable drum (see Fig. 1). In another embodiment, the test piece is made to rotate on the inner surface of a rotatable annular drum (see Fig. 2). In a further embodiment, the test piece is made to rotate on a top surface of a rotatable disc having a rotation axis orthogonal to the rotation axis of the test piece (see Figs. 3 and 5). In still another embodiment, the test piece is made to rotate on an endless belt (see Fig. 4). SUMMARY OF THE INVENTION In this description and in the subsequent claims, the following definitions apply. The term "tyre test sample" is used to indicate: a sample of a full-scale tyre or a small-scale (or miniaturized) tyre whose tread band is made of an elastomeric material identical to that of the tyre to be tested, ora small-scale (or miniaturized) tyre whose tread band is made of an elastomeric material identical to that of the tyre to be tested, ora disk-shaped test specimen comprising, on the radially outer surface thereof, an annular strip made of an elastomeric material identical to that of the tread band of the tyre to be tested. The term "radial" and the expressions "radially inner" and "radially outer" are used with reference to a direction substantially perpendicular to a rotation axis of the tyre test sample or of an annular drum. "Radially inner" means closer to the rotation axis along said direction, while "radially outer" means farther the rotation axis along said direction. The term "axial" is used with reference to a direction substantially coinciding with, or substantially parallel to, the rotation axis of said tyre test sample or of said annular drum. The term "controlled running conditions" is used to indicate specific conditions defined in the testing apparatus to simulate actual running conditions of a tyre test sample on a surface. Such specific conditions are defined upon imparting on the tyre test sample predetermined mechanical stresses (such as a predetermined vertical load and/or a predetermined traction force and/or a predetermined braking force and/or a predetermined lateral force) and/or predetermined angles (such as a predetermined slip angle and/or a predetermined cornering angle and/or a predetermined camber angle and/or a predetermined toe angle). In addition or in alternative to the above, the abovementione