Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
  • B29D30/00—Producing pneumatic or solid tyres or parts thereof
  • B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
  • B29D30/08—Building tyres
  • B29D30/20—Building tyres by the flat-tyre method, i.e. building on cylindrical drums
  • B29D30/24—Drums
  • B29D30/242—Drums for manufacturing substantially cylindrical tyre components without cores or beads, e.g. treads or belts
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
  • B29D30/00—Producing pneumatic or solid tyres or parts thereof
  • B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
  • B29D30/70—Annular breakers

Definitions

• the invention relates to the field of the manufacture of tires, and in particular that of the assembly of the components forming the crown of the tire.
• the assembly of the crown reinforcement plies and the tread is performed on a receiving surface, also called vertex shape, whose axial profile, or curve, is generally cylindrical.
• the vertex shape is composed of a set of radially movable elements for adjusting the diameter of the shape between an expanded position used during the assembly phase and a retracted position for extracting the annular element obtained at the end of this phase of construction of the tire.
• the peaks of modern tires usually comprise reinforcing plies forming an angle with the circumferential direction a reinforcement ply composed of circumferentially wound son and said zero-degree ply or zero-degree thread, and a tread capping the together. Once formed, this annular element is transferred to the portion of the tire comprising the carcass reinforcement ply and the reinforcing rings of the beads, to which a generally toroidal shape has been imparted. The assembly then constitutes a bandage intended to be placed in a baking press for the vulcanization operation.
• the object of the invention is to provide an alternative solution to shrinking under tension son zero degree by acting on the transverse curve of the receiving surface of generally cylindrical shape for the assembly of the blank of a tire, to receive the components forming a crown belt.
• the method of determining the curve of the receiving surface according to the invention comprises the following steps during which:
• the initial radial position is determined so that the wire of the turn considered undergoes the desired rate of elongation during the press conformation; determines, at the axial location of said turn, the transverse profile of the receiving surface by subtracting from the initial position of the wire the thickness of the components arranged radially inside the turn of said zero-degree wire.
• the cooking means generally formed by an expandable membrane, will force the crown area to penetrate into the part of the mold with the sculptures.
• the radial displacements imposed on the zero-degree wires will be greater or smaller depending on the laying diameter of these wires during the assembly phase of the top, which depends on the laying diameter, the surface profile pose of the summit form. These displacements determine the rate of conformation in press.
• Figure 2 shows a radial sectional view of a crown assembly shape having a double concavity.
• the crown assembly form 2 illustrated in FIG. 1 comprises a laying surface 21 on which a tire crown 1 has been shown during assembly, comprising a first crown reinforcement ply 11 and a second reinforcing ply.
• These crown reinforcing plies are generally formed of reinforcing threads forming an angle with the circumferential direction.
• the top also comprises reinforcement son 13i wound to zero degree without tension.
• the transverse profile of the receiving surface for receiving the components forming the crown belt 2, defined as a function of the distance Rfdp from the surface to the axis of rotation of the assembly form, has a generally concave whose concavity is oriented radially inward of the assembly form. This configuration can be useful when one seeks to give a greater tension to the shoulders than in the center, considering that the transverse profile of the mold in the crown zone is substantially flat.
• any wire to zero degrees can be determined according to its axial position the final radius Rf of the wire (in the stressed state) corresponding to the final position of the wire at this point when the tire is fitted into the mold of cooking and Ri the initial radius of the hoop (radius of installation of the hoop in the unconstrained state)
• e the thickness (the distance) separating said wire from the finishing drum.
• E represents the thickness of the products laid radially under the wire under consideration.
• the vertex assembly form 3 illustrated in Figure 2 has a laying surface comprising the combination of two concavities in opposite directions.
• the two axially opposite wings 31 have a concavity oriented towards the inside of the assembly form, while the central portion 32 located at the equator of the assembly form has a concavity facing outwards of the Summit shape.
• This profile therefore has at least one inflection point and, as a rule, at least an even number of inflection points due to the symmetry of the tire, making it possible to connect these different concavity curves.
• This profile allows pre-tensioning of the shoulder wires to improve the speed limit performance, and pre-tensioning the zero-degree wires in the equator area of the tire to improve performance. in wear.
• the latter solution has the advantage of giving greater industrial flexibility by allowing the creation of laying forms with carefully determined standard profiles, and on which one adjusts finely the laying tension of the wires to zero degrees to obtain the desired pre-tension.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Tyre Moulding (AREA)
• Ropes Or Cables (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=41600392

Family Applications (1)

Country Status (6)

Families Citing this family (3)

Family Cites Families (12)

• 2010
  • 2010-06-14 BR BRPI1014941A patent/BRPI1014941A2/pt not_active Application Discontinuation
  • 2010-06-14 CN CN2010800269501A patent/CN102802927A/zh active Pending
  • 2010-06-14 JP JP2012515450A patent/JP2012530004A/ja not_active Withdrawn
  • 2010-06-14 US US13/380,028 patent/US20120192637A1/en not_active Abandoned
  • 2010-06-14 WO PCT/EP2010/058297 patent/WO2010146011A1/fr active Application Filing
  • 2010-06-14 EP EP10725167A patent/EP2442969A1/de not_active Withdrawn

Non-Patent Citations (1)

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