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
  • B60C7/00—Non-inflatable or solid tyres
  • B60C7/10—Non-inflatable or solid tyres characterised by means for increasing resiliency
  • B60C7/12—Non-inflatable or solid tyres characterised by means for increasing resiliency using enclosed chambers, e.g. gas-filled
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/25—Component parts, details or accessories; Auxiliary operations
  • B29C48/88—Thermal treatment of the stream of extruded material, e.g. cooling
  • B29C48/91—Heating, e.g. for cross linking
  • B29C48/9105—Heating, e.g. for cross linking of hollow articles
• • 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
  • B29D30/02—Solid tyres ; Moulds therefor
• • 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
  • B60C15/00—Tyre beads, e.g. ply turn-up or overlap
  • B60C15/02—Seating or securing beads on rims
  • B60C15/0209—Supplementary means for securing the bead
  • B60C15/0213—Supplementary means for securing the bead the bead being clamped by rings, cables, rim flanges or other parts of the rim
• • 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
  • B60C15/00—Tyre beads, e.g. ply turn-up or overlap
  • B60C15/02—Seating or securing beads on rims
  • B60C15/028—Spacers between beads
• • 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
  • B60C7/00—Non-inflatable or solid tyres
  • B60C7/10—Non-inflatable or solid tyres characterised by means for increasing resiliency
  • B60C7/12—Non-inflatable or solid tyres characterised by means for increasing resiliency using enclosed chambers, e.g. gas-filled
  • B60C7/125—Non-inflatable or solid tyres characterised by means for increasing resiliency using enclosed chambers, e.g. gas-filled enclosed chambers defined between rim and tread
• • 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
  • B60C7/00—Non-inflatable or solid tyres
  • B60C7/24—Non-inflatable or solid tyres characterised by means for securing tyres on rim or wheel body
• • 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
  • B60C2200/00—Tyres specially adapted for particular applications
  • B60C2200/12—Tyres specially adapted for particular applications for bicycles

Definitions

• the present invention relates to a non-pneumatic tire, intended to be mounted on a rim and to equip a light vehicle, and more specifically to a tire member, adapted to be wound on a rim to form a non-pneumatic tire. for light vehicle.
• Light vehicle means a vehicle having a low mass, for example at most equal to 200 kg load, and moving at low speed, for example at most equal to 50 km / h.
• a bike, a car for children, a wheelchair for a disabled person are examples of light vehicles.
• the invention will be described more particularly for a non-pneumatic tire intended to equip a light vehicle with two bicycle-type wheels.
• a tire is an open hollow toric body constituted by at least one elastomeric material, subjected to a determined inflation pressure, a function of the dimensional characteristics of the tire and the load and speed stresses to which it is intended to as defined, for example, by the standards of the European Technical Rim and Tire Organization (“ETRTO").
• ETRTO European Technical Rim and Tire Organization
• a tire usually comprises a tread intended to come into contact with a ground via a running surface, and connected by two sidewalls to two beads intended to cooperate with a rim.
• a tire inflated to a predetermined initial pressure, has the disadvantage of having a gradual decrease in pressure over time, hence the need for continuous monitoring of the pressure. and possible pressure adjustments.
• This loss of pressure may be partial, in case of loss of tightness at the rim or piercing of the tread, or total, in case of bursting of the tire.
• a non-pneumatic tire is a toric body consisting of at least one polymeric material, intended to provide the function of a tire but without being subjected to an inflation pressure.
• a non-pneumatic bandage can to be full or hollow.
• a hollow non-pneumatic tire may contain air, but at atmospheric pressure, i.e. it has no pneumatic rigidity provided by an inflation gas at a pressure above atmospheric pressure.
• a non-pneumatic tire advantageously eliminates the stress of monitoring and pressure adjustment and the risk of loss of partial or total pressure of a tire.
• the rim on which is intended to be mounted a non-pneumatic tire, comprises two edges of rims interconnected by a rim bottom.
• a rim usually includes a rim hole for the implantation of an inflation valve.
• a rim may be constituted by a metallic or polymeric or composite material.
• Non-pneumatic tire designs have been proposed in the state of the art. Of the non-pneumatic tires proposed, some have been designed to have effective rim tightening.
• US patent application 20120318421 A1 discloses a non-pneumatic tire constituted by a closed hollow body of elastomeric material, fixed on a rim by a clamping element, positioned circumferentially inside the non-pneumatic tire.
• This cable-type clamping element comprises two respectively locking and toothed ends connected together to ensure clamping, at a hole opening on the outside surface of the non-pneumatic tire.
• This design has the disadvantage of having a rim clamping element that can be difficult to insert into the non-pneumatic tire.
• such a non-pneumatic tire of given dimension must be mounted on rim of suitable size.
• the document WO 2017067869 proposes a mounted assembly comprising a non-pneumatic tire mounted on a rim, with a mounting and a tightening on rim facilitated and with a flexible mountability, that is to say possible on rims having different but similar axial widths having a relative difference of not more than 20%.
• the mounted assembly described herein, includes a non-pneumatic tire mounted on a rim and a wire clamping insert applied over the entire radially inner circumference of the closed toric cavity of the non-pneumatic tire.
• the clamping insert comprises means clamping device applying a prestressing force ensuring a clamping clamping of a radially inner portion of the non-pneumatic tire on the rim.
• the non-pneumatic tire comprises at least one through circumferential discontinuity
• the radially inner portion of the non-pneumatic tire comprises two deformable beads geometrically adapting to the rim under the action of the crush clamping
• the insert of clamping passes successively, radially inwardly, the radially inner portion of the non-pneumatic tire and a rim hole, so that the clamping means are positioned radially inside the rim.
• this non-pneumatic tire has the disadvantage of having too much radial deflection or deflection when it is mounted on its rim and subjected to a nominal load as defined, for example, by the ETRTO standard.
• an excessive radial deflection can cause, in particular, a blistering, that is to say a local detachment, of the central portion of the running surface, in the contact area of the running surface with the ground.
• This blistering causes degraded operation of the tread, particularly with respect to wear and adhesion. Therefore the load bearing capacity of such a non-pneumatic tire is insufficient for optimal operation of the non-pneumatic tire.
• the non-pneumatic tire described in document WO 2017067869 has the particularity of being able to be obtained by winding on a rim of a bandage element cut to a length substantially equal to the circumference of the rim.
• the inventors have set themselves the objective of proposing a tire element, capable of being wound on a rim to form a non-pneumatic tire for a light vehicle, so that the non-pneumatic tire thus obtained has a carrying capacity of increased load compared to a hollow non-pneumatic tire of the state of the art.
• the bandage element being a hollow tubular body having a longitudinal mean line of length L and comprising at least one polymeric material, the bandage element comprising a top, intended to come into contact with a ground, and connected by two sidewalls to two beads intended to cooperate with the rim,
• the bandage element comprising two stiffening portions at least partially unrelated to each other, that is to say partially disjoined to each other, and in particular, in the main interior cavity open, so as to have behaviors essentially independent mechanical
• each stiffening portion extending into the open main interior cavity, from a transition zone between the bead and the flank to the vicinity of the middle of the apex, and delimiting, with a portion of bandage element facing said stiffening portion, a secondary internal cavity closed, such that the main interior cavity is thus divided into two closed secondary cavities, separated from each other by a third secondary cavity open to the level of beads.
• the object of the invention is a bandage element for producing a non-pneumatic tire by winding said bandage element on a rim.
• the non-pneumatic tire is made directly on the rim by winding the tire element, generally cut to a length substantially equal to the circumference of the mounting rim, and by butting the end faces of the tire. the bandage element thus cut. It is therefore not a non-pneumatic tire toric, manufactured beforehand and then mounted on a rim.
• the bandage element is a hollow tubular body having a longitudinal mean line of length L.
• the longitudinal middle line of the bandage element is the location of the centers of gravity of the sections perpendicular to said longitudinal mean line and is positioned in a longitudinal mean plane XZ passing through the middle of the apex.
• the direction XX ' is the longitudinal direction, tangent to the longitudinal mean line
• the direction ZZ' is the direction perpendicular to the longitudinal mean line and positioned in the longitudinal mean plane XZ
• the direction YY ' is the transverse direction, perpendicular to the longitudinal mean plane XZ.
• the bandage element comprises at least one polymeric material, which is the type of material commonly used in the field of non-pneumatic tires.
• the assembly consisting of the top, the two flanks and the two beads defines an inner main cavity open, the latter being open at the beads.
• the beads are not secured to each other by a portion of the bandage element.
• this open main internal cavity may contain at least one sub-cavity or closed secondary cavity.
• the bandage element comprises two stiffening portions at least partly unrelated, which make it possible to increase the stiffness of the bandage element with respect to crushing.
• These two stiffening portions are partially disjoined together, and in particular in the main interior cavity open, so as to have substantially independent mechanical behavior. They do not therefore constitute, for example, a lattice stiffening structure and contribute to the rigidity essentially by their intrinsic shape and by their constituent material.
• each stiffening portion extends in the main inner cavity open from each bead to the top, and delimits, with a portion of bandage element vis-à-vis - screw of said stiffening portion, a secondary internal cavity closed.
• the geometrical shape of each stiffening portion thus ensures a bracing of the bandage element, on either side of its longitudinal mean plane.
• the main interior cavity is thus divided into two closed secondary cavities, separated from each other by a third secondary cavity open at the beads.
• each stiffening portion extends into the open main interior cavity, from a transition zone between the bead and the flank to the vicinity of the middle of the top: which creates a bracing between the middle of the top and bead, without interaction with the flank.
• the previously described invention thus increases the load carrying capacity of a non-pneumatic tire, compared to a non-pneumatic reference hollow tire without stiffening portion.
• Rigidification of the non-pneumatic tire causes a reduction in the radial deformation of the top or boom, which ensures the full contact of the running surface with the ground, eliminating any risk of blistering, that is to say, local detachment of the running surface in its middle part.
• the two stiffening portions are symmetrical with respect to a longitudinal mean plane, passing through the middle of the apex and containing the longitudinal mean line of the bandage element. Since the bandage element is itself generally symmetrical with respect to its longitudinal mean plane, the symmetry of the stiffening portions guarantees a symmetrical behavior of the non-pneumatic tire when it is crushed on the ground.
• each banding element portion facing a stiffening portion having, in any transverse plane perpendicular to the longitudinal mean line of the banding element, a transverse curvature C 0
• each stiffening portion has, in any transverse plane, a transverse curvature Ci having an orientation opposite to that of the transverse curvature Co of the bandage portion portion vis-à-vis the stiffening portion. More precisely, since the transverse curvature Co of the tire element portion is concave, the transverse curvature Ci of the stiffening portion is convex.
• the two deformed stiffening portions are likely to come into contact with each other, and, by being supported one on the other by their outer faces. respective, to further increase the rigidity of the non-pneumatic tire with respect to crushing.
• the bandage element is advantageously constituted by a single polymeric material. This is the simplest embodiment from the point of view of design and manufacture.
• the polymeric material constituting the bandage element preferably has a Shore hardness of at least 70. Below this Shore hardness, stiffening is insufficient.
• the mechanical behavior of an elastomeric mixture can be characterized, in particular, by its Shore hardness, measured according to DIN 53505 or ASTM 2240 standards.
• the polymeric material constituting the banding element is advantageously an elastomeric thermoplastic material or a vulcanized thermoplastic material. These types of materials are commonly used in the field of non-pneumatic tires. They have the advantage of having moderate cooking temperatures, between 120 ° C and 250 ° C.
• the banding element has a curved longitudinal mean line having a monotonic radius of curvature R.
• a monotonic curvature radius R is, in the mathematical sense, a radius always having the same direction of variation. In other words, such a longitudinal average curve bandage element line has no inversion of curvature.
• the advantage of having a monotonic radius of curvature R is to facilitate, at first, the winding of the bandage element on a storage reel, then, in a second step, to facilitate its implementation by winding on a rim, thanks to this preformed initial geometry.
• the hollow tubular body when it is placed on a rim, the hollow tubular body may be subjected to buckling due to the strong extension of its portion corresponding to the summit and the strong compression of the portion corresponding to the beads.
• the radius of curvature R of the bandage element is generally substantially constant and must be compatible with the radius of the rim on which the bandage element is intended to be put in place.
• the radius of curvature R can be comprised, typically, between 200 mm and 500 mm.
• each bead comprises a longitudinal groove opening on an inner face of the bead, vis-à-vis the main interior cavity open, and extending over the entire length L of the element bandage.
• the presence of such a longitudinal groove in each bead allows in particular to accommodate the ends of a possible insert of tightening, connecting the beads to each other and ensuring a better tightening of the non-pneumatic tire on its rim.
• the invention also relates to a method of manufacturing a bandage element as previously described.
• the method of manufacturing a bandage element as previously described comprises a hot extrusion step of the hollow tubular body constituting the bandage element.
• Such a method simultaneously makes it possible to achieve the geometry required for the bandage element and to cook the constituent polymeric materials of the bandage element.
• the two extrusion and cooking steps are therefore simultaneous.
• the extrusion temperatures are between 120 ° C and 250 ° C.
• the method of manufacturing such a bandage element comprises an extrusion step in a hot state of the hollow tubular body constituting the banding element, with the aid of an extrusion nozzle having a curved longitudinal average line having a monotonous radius of curvature R.
• This particular embodiment of the hot extrusion process allows to obtain directly, thanks to the curved shape of the extrusion nozzle, a bandage element having a curved longitudinal mean line having a monotonic radius of curvature R.
• - Figure 1 A Cross section of a bandage element according to the invention.
• FIG. 1B Perspective view of a bandage element according to the invention.
• - Figure 1C Side view of a bandage element according to the invention.
• - Figure 2 Cross section of a non-pneumatic tire, obtained by winding a bandage element according to the invention, in a crushed state.
• - Figure 3A partial perspective view of a non-pneumatic tire in progress, by winding a bandage element according to the invention on a rim.
• - Figure 3B partial perspective view of a non-pneumatic tire obtained by winding a bandage element according to the invention on a rim.
• FIG. 4 Schematic diagram of a method of hot extrusion of a curved bandage element according to a preferred embodiment of the invention.
• FIG. 1A shows a cross section, in a transverse plane YZ, of a bandage element according to the invention.
• the bandage element 1 is a hollow tubular body, comprising at least one polymeric material. It comprises a top 2, intended to come into contact with a ground, and connected by two sides 3 to two beads 4, intended to cooperate with a rim (not shown).
• the assembly consisting of the top 2, the two sides 3 and the two beads 4, delimits an open main internal cavity 5.
• the bandage element 1 comprises two stiffening portions 6 at least partly unrelated between them, and each stiffening portion 6 extends into the main inner cavity open 5 from each bead 4 to the top 2, and delimits, with a portion of bandage element 7 vis-à-vis said stiffening portion 6, a closed secondary internal cavity 8.
• the two stiffening portions 6 are symmetrical with respect to the longitudinal mean plane XZ, passing through the middle of the vertex 2 and containing the longitudinal mean line L m (shown in Figure 1 C) of the bandage element 1.
• each stiffening portion 6 has, in the transverse plane YZ, a transverse curvature Ci having an orientation.
• each bead 4 comprises a longitudinal groove 41 opening on an inner face of the bead 42, vis-à-vis the main open inner cavity 5, and extending over the entire length L of the bandage element 1.
• Figure 1B is a perspective view of a bandage element according to the invention, whose cross section is shown in Figure 1A.
• FIG. 1C is a side view of a bandage element according to the invention, in the particular case where the banding element 1 has a longitudinal mean line L m curve having a monotonic radius of curvature R.
• FIG. 2 is a cross-section, in a transverse plane YZ, of a non-pneumatic tire obtained by winding a bandage element according to FIG. the invention, in a crushed state.
• a rim 10 on which the tire element is wound in order to form a non-pneumatic tire, and a tightening insert 9, the ends of which are positioned in the longitudinal grooves. 41 of each bead 4 to ensure optimum clamping of the beads 4 on the rim 5.
• This clamping insert 9, in the case shown, has the shape of a ribbon extending circumferentially, in the direction XX ', on the entire circumference of the non-pneumatic tire.
• the stiffening portions 6 come into contact with each other, and, by being supported on each other by their respective outer faces, increase the rigidity of the non-pneumatic tire with respect to crushing.
• Figure 3A is a partial perspective view of a non-pneumatic tire in progress, by winding a bandage element 1 according to the invention on a rim 10.
• the bandage element 1 cut to a length L substantially equal to the circumference of the rim 10, and provided with a clamping insert, in the form of ribbon 9, is placed progressively on the rim 10, with an adjustment of the beads against the edges of the rim.
• Figure 3B is a partial perspective view of a non-pneumatic tire obtained by winding a bandage element according to the invention on a rim and represents the final state of the assembly thus produced.
• FIG. 4 schematically depicts the device for producing the hot extrusion step of the hollow tubular body constituting the bandage element 1, with the aid of an extrusion nozzle 11 having a longitudinal mean line L ' m Curve having a monotonous radius of curvature R.
• the resulting bandage element 1 therefore has a longitudinal mean line L m curve having a monotonous radius of curvature R, and is easy to wind on a reel storage, waiting for the realization of a non-pneumatic tire.
• the invention has been more particularly studied in the case of a non-pneumatic tire for bicycle size 37-622, according to the designation of the ETRTO standard.
• a non-pneumatic tire for a bicycle has a section width in the direction YY 'equal to 37 mm and a section height in the direction ZZ' equal to 39 mm. It is intended to be mounted on a rim having a diameter equal to 622 mm.
• Each stiffening portion of the banding element has a thickness equal to 3 mm and a curvilinear length, between its interface with the bead and its interface with the top, equal to 22 mm.
• each stiffening portion of the banding element has an interface with the bead positioned in the direction ZZ 'at a distance from the end of the bead equal to 3 mm and has an interface with the vertex positioned in the direction YY ', at a distance, relative to the longitudinal mean plane XZ, equal to 2 mm.
• the polymeric material constituting the banding member is a vulcanized thermoplastic material having a Shore A hardness of 86, measured at 23 ° C, and a firing temperature of between 175 ° C and 230 ° C.
• the banding element has a curved longitudinal mean line having a monotonic radius of curvature R equal to about 300 mm.
• the inventors have shown that the stiffening of the non-pneumatic tire causes a significant decrease in the radial deformation of the apex or arrow.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Tires In General (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=61132771

Family Applications (1)

Country Status (4)

Family Cites Families (21)

• 2018
  • 2018-12-17 WO PCT/FR2018/053322 patent/WO2019122645A1/fr unknown
  • 2018-12-17 EP EP18833694.5A patent/EP3727882A1/de not_active Withdrawn
  • 2018-12-17 CN CN201880081982.8A patent/CN111491806A/zh active Pending
  • 2018-12-17 US US16/955,769 patent/US20200338927A1/en not_active Abandoned

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