Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
  • B60C11/03—Tread patterns
  • B60C11/04—Tread patterns in which the raised area of the pattern consists only of continuous circumferential ribs, e.g. zig-zag
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
  • B60C11/03—Tread patterns
  • B60C11/0306—Patterns comprising block rows or discontinuous ribs
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
  • B60C11/03—Tread patterns
  • B60C11/0306—Patterns comprising block rows or discontinuous ribs
  • B60C11/0309—Patterns comprising block rows or discontinuous ribs further characterised by the groove cross-section
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C99/00—Subject matter not provided for in other groups of this subclass
  • B60C99/006—Computer aided tyre design or simulation
• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06F—ELECTRIC DIGITAL DATA PROCESSING
  • G06F30/00—Computer-aided design [CAD]
  • G06F30/20—Design optimisation, verification or simulation
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
  • G01M17/00—Testing of vehicles
  • G01M17/007—Wheeled or endless-tracked vehicles
  • G01M17/02—Tyres

Definitions

• a tire for a vehicle carrying heavy loads comprises a tread intended to ensure the rolling contact of the tire with the roadway and to transmit forces in the running direction (engine or braking force) and in a direction transverse to the direction of travel (cornering efforts).
• This tread is provided with a plurality of recesses in the form of grooves and / or incisions to improve the driving conditions when the roadway is covered with water or snow.
• These grooves delimit relief elements (ribs or blocks) distributed over the tread; there are edge portions axially delimiting the tread and intermediate portions located axially between these edge portions.
• a tire comprises, in addition to a tread, beads intended to be in contact with a mounting rim, a side connecting each bead to a crown region, the latter being capped by the tread.
• the tire assembly is reinforced by a carcass reinforcement anchored at both ends in the beads and extending into the flanks and the crown region. Radially between the carcass reinforcement and the tread is a crown reinforcement.
• the carcass reinforcement is said to be radial when its reinforcements are oriented in a direction making an angle greater than or equal to 80 degrees with a direction tangent to the circumferential direction.
• radial direction in this document is meant a direction that is perpendicular to the axis of rotation of the tire (this direction corresponds to the direction of the thickness of the tread).
• Axial direction means a direction parallel to the axis of rotation of the tire.
• circumferential direction is meant a direction which is perpendicular to both the axial direction and a radial direction.
• Axially outwardly means a direction which is oriented outwardly of the internal cavity of the tire.
• Equatorial plane plane perpendicular to the axis of rotation and passing through the axially outermost points of the tire, this equatorial plane virtually dividing the tire into two substantially equal halves.
• the object of the invention is to solve both this problem of irregular wear on tires steered on steering axle while avoiding the sensitivity to tearing under particularly severe conditions of use.
• the object of the invention relates to a tread for truck tire complying with the objective specified above, and a method of sizing such a tire.
• the lengths LEp and PREp being expressed in millimeters (mm), and the angle DEp in degrees (°).
• ROUND we mean a function which results in the lower integer value of a number whose fractional / decimal part is at most 0.5 and which gives the integer value of a number if its fractional fraction / decimal is greater than 0.5.
• ROUND (2.4) is 2
• ROUND (2.6) is 3.
• the sizing method is such that for each intermediate rib, the difference between the depths of two grooves delimiting the same rib is small, that is to say that this difference is at most equal to 10% of the greatest depth of these grooves.
• the sizing method is applied to the case where the edge rib and the directly adjacent rib are of different heights, and such that the difference between these heights is at most equal to 15% of the smallest of these heights.
• the sizing method is applied in the case where the angle DEp of the inner sidewall of each rib edge with a radial direction is chosen to be at most equal to 26 degrees, and the angle of the sidewall vis-à-vis in the same groove is chosen to be at most equal to 20 degrees. Even more advantageously in the latter case, the sizing method is applied in the case where the width of each edge rib Lep is chosen to be at least 1.85 times greater than the width of any other intermediate rib. Even more preferably the angle DEp of the inner sidewall of each rib edge with a radial direction is chosen in an interval ranging from 10 degrees to 26 degrees, the angle of the side wall vis-à-vis in the same groove being chosen to be at most equal to 20 degrees.
• the invention also relates to a tire obtained by the method according to the invention.
• P (LEp, DEp, PREp) -303.528 - 2.00675 x LEp + 10.2755 x DEp + 81.0414 x PREp - 0.052551 x LEp 2 -0.0825991 x LEp x DEp + 0.225564 x LEp x PREp - 0.111262 x DEP 2 - 0.209215 x DEP x PREp - 2.5831 x PREp 2 .
• the tire according to the invention comprising a crown reinforcement under the tread, this crown reinforcement comprising several layers of superposed reinforcements is such that the end of the axially widest vertex ply is located, with respect to the equatorial plane of the tire, axially at a distance greater than the axial distance of the axially outermost groove.
• this widest crown ply is present radially under the shoulder rib over a distance at least equal to 75% of the total width LEp of this shoulder rib.
• the tire according to the invention is such that the width of each groove, measured on the running surface in the new state, is at least equal to 3% of the total width Lo of the tire strip. rolling.
• the angle of inclination DEp of the inner sidewall of the rib edge and the angle of inclination of the wall vis-à-vis the inner sidewall are such that the sum of these two angles are greater than or equal to 26 degrees.
• the angle of inclination DEp of the inner side wall of the edge rib varies continuously from a minimum value satisfying the relation P (LEp, DEp, PREp) ⁇ 1.10576923 lxF, this value remaining always greater than or equal to 10 degrees.
• the angle of inclination DEp of the internal lateral wall of the rib edge is preferably limited to at most 6 degrees, so that these protuberances are not weakened.
• the protuberances in question may be circumferentially continuous or discontinuous. They have preferably a height at least equal to 50% of the height PREp of the inner side wall of the edge rib and a width at least equal to half the width of the groove in which they are formed.
• Figure 1 shows a plan view of a portion of the tread
• Figure 2 shows a sectional view of a tire constructed using the method of the invention
• Figure 3 shows a variant of a tire constructed according to the invention and for which the crown reinforcement extends radially under the edge ribs;
• Figure 4 shows in section a variant of a tire according to the invention, the tire comprising groove bottom protrusions protrusions.
• Figure 1 shows a plan view of a portion of the tread 1 constructed according to the invention for a tire for equipping the steering axle of a heavy vehicle.
• This band comprises four grooves 2 of circumferential orientation, these grooves defining three intermediate ribs 3 and two edge ribs 4 at the axial ends of the strip.
• These ribs 3, 4 are further provided with grooves or incisions 31, 32, 41, 42 of small width compared to the widths of the circumferential grooves 2.
• These grooves or additional incisions are, in the case presented, oriented obliquely to the circumferential direction represented by the direction XX 'in FIG.
• Figure 2 shows partially the tire of Figure 1 seen in section in a plane containing the axis of rotation YY 'of the tire.
• This tire comprising beads 7 resting on a mounting rim J, the latter comprising axially outer portions forming a rim hook C.
• this tire comprises sidewalls 10 extending the beads 7, and extending radially beyond the rim hooks C, these flanks being interconnected by a crown portion 6.
• This crown portion of the tire is provided radially outwardly with the tread 1 whose tread design has
• This tire has a nominal sidewall height F equal to the distance measured in the radial direction separating the edge axially. on the outside 11 of the tread and the radially outermost point A of the mounting rim J in the plane of section of FIG.
• each edge rib 4 comprises a contact surface 400 intended to come into contact with the roadway during the rolling and two side walls 401, 402 intersecting the contact surface in the form of ridges. one of these side walls, said inner side wall 402 delimiting, with a side wall 301 vis-à-vis a neighboring intermediate rib 3, a groove 2 of width L E. This groove 2 to a depth PREp measured between the bottom 2 'of the groove and the contact surface 400 of the rib edge 4. This PREp measurement corresponds to the height of the rib edge 4.
• edge and intermediate ribs are all substantially at the same level, that is to say that none of the contact surfaces of said ribs is offset in the radial direction relative to the contact surfaces of at least one other rib. If this were the case, the heights PREp, PRi of each sidewall of each edge rib and intermediate respectively should be considered.
• Each edge rib has a width LEp and the intermediate ribs have a width Li substantially the same and less than the width LEp.
• the maximum axial width Lo of the tread is equal to 315 mm, and the shape ratio H / S is equal to 0.80. Knowing that the height of the hook of the mounting rim of this tire is normalized and equal to 12.5 mm, a value of the parameter F is obtained:
• the grooves 2 have a width equal to 14 mm
• the intermediate ribs 3 have widths equal to 30 mm
• the grooves, with the exception of the grooves delimiting the edge ribs 4 have depths equal to 16.2 mm.
• the angle of the side walls 301 of the intermediate ribs is equal to 13 °.
• FIG. 3 shows another variant of tire according to the invention, this tire comprising a carcass reinforcement 5 surmounted radially on the outside by a crown reinforcement 60 itself surmounted radially on the outside by a tread 1 satisfying the inequality relation P (LEp, DEp, PREp) ⁇ 1.105769231 x F.
• the crown reinforcement 60 comprises several reinforcing plies 61,
• the axially outer end 630 of the reinforcing ply 63 of the axially widest vertex armature is at a distance from the equatorial plane, having the line PP 'as a trace in the cutting plane, which is greater than the axial distance separating the axially outermost groove of the same equatorial plane, so that the distance between the end of the ply axially the most the outside and the inner edge of the shoulder rib is at least 75% of the total width of the shoulder rib LEp.
• the crown reinforcement width Ls radially under the rib edge is at least equal to 75% of the width LEp of the shoulder rib.
• Figure 4 shows in section a variant of a tire according to the invention, the tire comprising protrusions of groove bottom protection to prevent objects, such as stones, enter the grooves edge and can not s 'to escape to come gradually to attack the bottom of the grooves and more particularly the bottom of the edge grooves. It is easy to understand that these attacks will increase the sensitivity to the breaking of groove bottoms.
• protuberances 21 As can be seen in Figure 4 showing a partial section of a tire according to the invention, there are provided in the two grooves edges 2 protuberances 21, here discontinuous circumferentially, these protuberances 21 having a height h21 equal at 60% of the height PRep of the edge ribs 4, and width, measured on its portion radially furthest from the axis of rotation, equal to half the width LRe of the groove delimited by the edge rib.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Computer Hardware Design (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Theoretical Computer Science (AREA)
• Evolutionary Computation (AREA)
• Geometry (AREA)
• General Physics & Mathematics (AREA)
• Tires In General (AREA)

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Publications (1)

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Family Applications (1)

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Citations (4)

Family Cites Families (4)

• 2009
  • 2009-12-08 FR FR0958728A patent/FR2953455B1/fr not_active Expired - Fee Related
• 2010
  • 2010-12-03 EA EA201290464A patent/EA020836B1/ru not_active IP Right Cessation
  • 2010-12-03 WO PCT/EP2010/068888 patent/WO2011069927A1/fr active Application Filing
  • 2010-12-03 EP EP10787438.0A patent/EP2509804B1/fr active Active
  • 2010-12-03 CN CN201080055446.4A patent/CN102648100B/zh not_active Expired - Fee Related
  • 2010-12-03 US US13/511,522 patent/US9211766B2/en not_active Expired - Fee Related
  • 2010-12-03 JP JP2012542479A patent/JP5767649B2/ja not_active Expired - Fee Related
  • 2010-12-03 BR BR112012013565A patent/BR112012013565A2/pt not_active IP Right Cessation

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