Method for manufacturing support structure with cord-reinforced polymer composition spokes for non-pneumatic tires

Abstract

The present invention relates to an advanced method of manufacturing a support structure for a non-pneumatic tire, the support structure comprising at least one cord reinforced polymer composition spoke. A method includes providing a first mold member at least partially covered by a first polymer composition layer, applying at least one cord reinforcement onto the first polymer composition layer, and overmolding a second polymer composition layer onto the first polymer composition layer to enclose the cord reinforcement between the first polymer composition layer and the second polymer composition layer, thereby obtaining at least a portion of the cord reinforced polymer composition spoke. In some methods, the support structure includes the provision of X-shaped spokes and corresponding mold inserts and / or mold members. Furthermore, the present invention relates to a method of manufacturing a tire comprising molding at least one circumferential segment of a support structure comprising a cord reinforced polymer composition.

Description

Technical Field

[0001] The present invention relates to a method of manufacturing a support structure for a non-pneumatic tire, the support structure comprising cord-reinforced polymer composition spokes. In addition, the present invention relates to a method of manufacturing a non-pneumatic tire comprising such a support structure and / or spokes. Background Art

[0002] Some non-pneumatic tires include a support structure disposed between a tread band and a wheel hub portion, wherein the support structure includes a plurality of spokes. In some cases, such spokes include a polymeric material. To improve the durability of the spokes, such spokes may be reinforced with cords or fibrous materials. Although progress has been made in the development of polymeric spokes for non-pneumatic tires in the past few years, there is still much room for improvement. Summary of the Invention

[0003] In a first aspect, the present invention relates to a method of manufacturing a support structure for a non-pneumatic tire, the support structure comprising at least one cord-reinforced polymer composition spoke. The method includes the steps of providing a first mold member at least partially covered with a first polymer composition layer, applying at least one cord reinforcement to the first polymer composition layer, and overmolding a second polymer composition layer onto the first polymer composition layer to enclose the cord reinforcement between the first polymer composition layer and the second polymer composition layer and obtain at least a portion of the cord-reinforced polymer composition spoke.

[0004] In a second aspect, the present invention relates to a method of manufacturing a support structure for a non-pneumatic tire, the non-pneumatic tire support structure comprising at least one X-shaped and cord-reinforced polymer composition spoke, wherein the X-shaped spoke has a pair of upper legs and a pair of lower legs, and the upper and lower legs are connected by a cross portion. The method includes the step of providing a mold, the mold including a mold member, the mold member including i) a first prismatic mold insert for defining an inner surface of the X-shaped spoke between its upper legs, ii) a second prismatic mold insert for defining an inner surface of the X-shaped spoke between its lower legs, and iii) at least one additional mold member for defining an outer surface of the X-shaped spoke, the outer surface being substantially opposite to the inner surface defined by the first and second mold inserts, wherein at least one mold member is at least partially covered with at least one polymer composition layer. Further steps of the method include applying a cord reinforcement to the polymer composition layer and injection molding an additional polymer composition onto the cord reinforcement and the polymer composition layer to wrap the cord reinforcement with the additional polymer composition and the polymer composition layer.

[0005] In a third aspect of the present invention, the present invention relates to a method of manufacturing a non-pneumatic tire, the non-pneumatic tire including a radially outer circumferential tread band, a radially inner hub portion, and a circumferential support structure that supports the radially outer circumferential tread band on the radially inner hub portion, wherein the support structure includes a circumferential and radially outer ring portion, a circumferential and radially inner ring portion, and a plurality of cord-reinforced polymer composition spokes disposed circumferentially and arranged between the radially outer ring portion and the radially inner ring portion. The method includes the step of providing a mold for molding at least one circumferential sector segment of the circumferential support structure, wherein the mold includes a radially outer mold ring member for molding the radially outer side of at least one circumferential sector segment of the radially outer ring portion, a radially inner mold ring member for molding the radially inner side of at least one circumferential sector segment of the radially inner ring portion, and a mold insert for molding a plurality of spokes between the mold ring members, wherein most of the mold members are covered by a polymer composition layer. The method further includes the steps of applying at least a cord reinforcement to portions of the polymer composition layer, wherein the cord reinforcement strengthens and connects the plurality of circumferentially disposed spokes to be molded; and injection molding an additional polymer composition onto the cord reinforcement and the polymer composition layer to enclose the cord reinforcement with the additional polymer composition and the polymer composition layer.

[0006] The present invention provides the following technical solutions:

[0007] 1. A method of manufacturing a support structure for a non-pneumatic tire, the support structure including at least one cord-reinforced polymer composition spoke, the method including the steps of:

[0008] providing a first mold member at least partially covered by a first polymer composition layer;

[0009] applying at least one cord reinforcement to the first polymer composition layer; and

[0010] co-molding a second polymer composition layer onto the first polymer composition layer to enclose the cord reinforcement between the first polymer composition layer and the second polymer composition layer and obtain at least a portion of a cord-reinforced polymer composition spoke.

[0011] 2. The method according to embodiment 1, wherein the first polymer composition layer includes at least one groove, and wherein the cord reinforcement is applied to the first polymer composition layer in the groove.

[0012] 3. The method according to embodiment 1, wherein the first mold member is a mold insert, and the method further includes the further step of:

[0013] Provide at least one second mold member to form a gap between the first polymer composition layer on the mold insert and the second mold member, and

[0014] wherein the step of overmolding the second polymer composition layer includes injecting the second polymer composition into the gap to form the second polymer composition layer.

[0015] 4. The method according to aspect 1, wherein the first mold member is at least partially wrapped by the first polymer composition layer.

[0016] 5. The method according to aspect 4, wherein the first mold member substantially has a prismatic shape and is wrapped by the first polymer composition layer on three circumferentially adjacent sides.

[0017] 6. The method according to aspect 1, wherein the first polymer composition and the second polymer composition include one or more of an elastomeric composition and a thermoplastic polymer.

[0018] 7. The method according to aspect 1, wherein the cord reinforcement includes at least one cord, and the cord includes one or more of a textile material, a glass fiber material, a carbon fiber material, a boron fiber material, a basalt fiber material, a plant-based material, and combinations of these materials.

[0019] 8. The method according to aspect 1, wherein the first polymer composition layer is solid when the cord reinforcement is applied to the first polymer composition layer.

[0020] 9. The method according to aspect 1,

[0021] wherein the first mold member substantially has a prismatic shape and is wrapped by the first polymer composition layer on three circumferentially adjacent sides, and

[0022] wherein the method further comprises the steps of:

[0023] providing an additional mold member that substantially has a prismatic shape and is wrapped by an additional polymer composition layer on three circumferentially adjacent sides, wherein each of the first mold member and the additional mold member is arranged with edges pointing towards each other and parallel to each other; and

[0024] applying the cord reinforcement to at least one side of the first mold member wrapped with the first polymer composition layer and to at least one side of the additional mold member wrapped with the additional polymer composition layer.

[0025] 10. The method according to embodiment 1, wherein the step of providing a first mold member covered by a first polymer composition layer includes the sub-step of overmolding the first polymer composition layer onto the first mold member.

[0026] 11. The method according to embodiment 1, wherein the cord reinforcement is a cord, and wherein a plurality of portions of the cord spaced apart from each other along the cord are applied to the first polymer composition layer.

[0027] 12. The method according to embodiment 11, wherein the plurality of portions of the cord applied to the first polymer composition layer are applied side by side to the first polymer composition layer.

[0028] 13. The method according to embodiment 12, wherein the plurality of portions applied side by side are spaced apart from each other by a certain distance.

[0029] 14. The method according to embodiment 1, wherein the spoke includes a substantially X-shaped cross-section.

[0030] 15. The method according to embodiment 9, wherein the spoke includes a substantially X-shaped cross-section having a pair of upper legs, a pair of lower legs, and an intersection portion connecting the pair of upper legs and the pair of lower legs, wherein the first mold member is disposed between the pair of upper legs to at least partially define the upper legs on the inner side, and an additional mold member is disposed between the pair of lower legs to at least partially define the lower legs on the inner side, and

[0031] wherein the method further includes providing one or more additional mold members facing the first mold member and the additional mold member to define the upper legs and the lower legs on the outer side.

[0032] 16. The method according to embodiment 1, further including the step of removing the first mold member after overmolding.

[0033] 17. A method for manufacturing a support structure for a non-pneumatic tire, the support structure including at least one X-shaped and cord-reinforced polymer composition spoke, wherein the X-shaped spoke has a pair of upper legs and a pair of lower legs connected by an intersection portion, and wherein the method includes the following steps:

[0034] A) Providing a mold including mold members, the mold members including i) a first prismatic mold insert for defining the inner surface of the X-shaped spoke between its upper legs, ii) a second prismatic mold insert for defining the inner surface of the X-shaped spoke between its lower legs, and iii) at least one additional mold member for defining the outer surface of the X-shaped spoke, the outer surface being substantially opposite to the inner surface defined by the first and second mold inserts, wherein at least one of the mold members is at least partially covered by at least one polymer composition layer;

[0035] B) applying a cord reinforcement to the polymer composition layer; and

[0036] C) injection molding an additional polymer composition onto the cord reinforcement and the polymer composition layer so as to wrap the cord reinforcement with the additional polymer composition and the polymer composition layer.

[0037] 18. The method according to embodiment 17, wherein at least a portion of the polymer composition layer includes at least one groove that is substantially parallel to and extends along a leg of the spoke, and wherein the cord reinforcement is applied to the polymer composition layer within the groove to restrict movement of the cord reinforcement perpendicular to the groove.

[0038] 19. The method according to embodiment 17, wherein the polymer composition layer is provided as an overmolding sleeve on respective mold inserts and circumferentially surrounds the respective mold inserts.

[0039] 20. A method of manufacturing a non-pneumatic tire, the non-pneumatic tire including a radially outer circumferential tread band, a radially inner hub portion, and a circumferential support structure that supports the radially outer circumferential tread band on the radially inner hub portion, wherein the support structure includes a circumferential and radially outer ring portion, a circumferential and radially inner ring portion, and a plurality of cord-reinforced polymer composition spokes that are circumferentially disposed and arranged between the radially outer ring portion and the radially inner ring portion, and wherein the method includes the steps of:

[0040] Providing a mold for molding at least one circumferential sector segment of the circumferential support structure, the mold including: a radially outer mold ring member for molding the radially outer side of at least one circumferential segment of the radially outer ring portion; a radially inner mold ring member for molding the radially inner side of at least one circumferential segment of the radially inner ring portion; and mold inserts for molding the spokes among the plurality of spokes located between the mold ring members, wherein most of the mold inserts are covered with a polymer composition layer;

[0041] Applying a cord reinforcement at least to portions of the polymer composition layer, wherein the cord reinforcement strengthens and connects the plurality of circumferentially disposed spokes to be molded; and

[0042] Injection molding an additional polymer composition onto the cord reinforcement and the polymer composition layer so as to wrap the cord reinforcement with the additional polymer composition and the polymer composition layer. Description of the Drawings

[0043] The present invention will be described by way of example and with reference to the drawings, in which:

[0044] Figure 1 is a schematic side view of an embodiment of a non-pneumatic tire that includes a support structure between the tread band and the hub portion of the tire;

[0045] Figure 2 is Figure 1 A schematic cross-section of an example of a cord-reinforced spoke of the support structure of the tire shown;

[0046] Figure 3 A schematic, partially transparent cross-section of another example of a cord-reinforced spoke for a non-pneumatic tire;

[0047] Figure 4 Shows a method of providing a mold member covered with a polymer composition layer according to an example of the present invention;

[0048] Figure 5 Shows a method of manufacturing a cord-reinforced polymer composition spoke according to an example of the present invention;

[0049] Figure 6 Is a schematic perspective view of a cord wound multiple times around a mold insert according to another example of a method of manufacturing a cord-reinforced polymer composition spoke;

[0050] Figure 7 Is a schematic perspective view of a mold insert according to another example of the present invention, the mold insert including a polymer composition layer having grooves for receiving and spatially separating cords or cord segments;

[0051] Figure 8 Is a schematic perspective view of an example of a circumferential or sector segment of a support structure according to an example of the present invention;

[0052] Figure 9 is for manufacturing Figure 8 A schematic cross-section of a mold including a plurality of mold members of the support structure already shown in;

[0053] Figure 10 is using according to Figure 9 A schematic cross-section of a circumferential sector segment of a cord-reinforced support structure obtainable with the mold of; and

[0054] Figure 11 is using according to Figure 9 Another schematic cross-section of a circumferential sector segment of a cord-reinforced support structure obtainable with the mold of. Detailed Description

[0055] In a first aspect, the present invention relates to a method of manufacturing a support structure for a non-pneumatic tire, the support structure comprising at least one cord-reinforced polymer composition spoke. The method comprises the steps of: providing a first mold member at least partially covered by an optionally preformed first polymer composition layer; applying at least one cord reinforcement to the first polymer composition layer; overmolding a second polymer composition layer onto the first polymer composition layer (and the cord reinforcement) to enclose the cord reinforcement, or in other words, encapsulate it between the first polymer composition layer and the second polymer composition layer) and / or obtain at least a portion of the cord-reinforced polymer composition spoke.

[0056] Providing the polymer composition layer helps to avoid exposure of the cord reinforcement on the surface of the spoke or a portion thereof. In particular, the material thickness of the first polymer composition layer (which is preferably solid when the cord reinforcement is applied) prevents the cord reinforcement from contacting adjacent portions of the first mold member when applied to the first polymer composition layer covering the first mold member. Thus, when the first mold member (and optionally additional mold members) is removed, the cord reinforcement remains covered and / or hidden by the first (and second) polymer composition layers. The method also allows for the creation of a defined position for one or more cord reinforcements in the spoke, for example in the central portion of the spoke thickness.

[0057] In one embodiment, the first polymer composition layer comprises at least one groove, wherein the cord reinforcement (such as a cord or a cord-reinforced tape) is applied to the first polymer composition layer in the groove. Preferably, the depth of the groove is less than the maximum thickness of the first polymer composition layer such that the cord reinforcement is applied to the material of the polymer composition layer in the groove. Such a groove helps to further define the position of the cord reinforcement in the spoke to be manufactured and / or avoid movement of the cord reinforcement during the overmolding. Optionally, a plurality (preferably parallel) of grooves and / or segments thereof are provided on the first polymer composition layer, which allows for the placement of a plurality of parallel cord reinforcements or cord-reinforced segments on the first polymer composition layer and thus a plurality of parallel cord reinforcements or cord-reinforced segments within the spoke. In particular, the groove can restrict movement of the cord reinforcement transverse to the groove extension.

[0058] In another embodiment, the first mold member is a mold insert, and / or the method comprises a further step of providing at least one second mold member to form a gap between the first polymer composition layer on the first mold insert / member and the second mold member. Optionally, the step of overmolding the second polymer composition layer comprises injecting the second polymer composition into the gap to form the second polymer composition layer.

[0059] In another embodiment, the first die member is at least partially wrapped by a first polymer composition layer. Optionally, the first polymer composition layer forms a sleeve covering the surface of the first die member.

[0060] In yet another embodiment, the first die member substantially has a prismatic shape and is wrapped with a first polymer composition layer on three circumferentially adjacent sides.

[0061] In yet another embodiment, the first polymer composition and / or the second polymer composition includes one or more of an elastomeric composition (such as a rubber composition) and a thermoplastic polymer (such as a thermoplastic elastomer, such as a thermoplastic polyester elastomer).

[0062] In one embodiment, the first polymer composition and the second polymer composition are the same. For example, this may help to provide the same material properties throughout the spoke. Providing the same material can improve the adhesion between the two layers.

[0063] In another embodiment, the first polymer composition and the second polymer composition are different. In some cases, it may be desirable to provide different material properties for one part or side of the spoke than for another part or side. The present method provides a simple and effective way to provide such different properties by providing at least two different polymer compositions. Optionally, if different polymer compositions are used, they are one or more of the following: i) capable of adhering to and / or being compatible with each other, ii) two elastomeric compositions, such as rubber compositions, iii) capable of being co-cured with each other.

[0064] In yet another embodiment, the polymer can be one or more of the following: i) one or more polyamide polymers (such as PA-12, PA-11, PA-6); ii) one or more thermoplastic polymers, such as thermoplastic polyester elastomers, thermoplastic polyurethane elastomers, polyamide thermoplastic elastomers, elastomer alloy thermoplastic vulcanizates, thermoplastic polyolefin elastomers, styrene thermoplastic elastomers, thermoplastic resins (such as polyester resins, polyamide resins or polyurethane resins). In particular, the term "thermoplastic polymer" should also include thermoplastic resins herein.

[0065] In yet another embodiment, the thermoplastic polymer is a thermoplastic elastomer, such as a thermoplastic polyester elastomer.

[0066] In another preferred embodiment, the polymer composition is an elastomeric composition, such as a rubber composition. Optionally, the elastomeric composition (such as a rubber composition) comprises one or more rubbers (such as comprising one or more natural rubbers, synthetic polyisoprene, butadiene rubber, styrene-butadiene rubber, and butyl rubber), fillers (such as comprising one or more carbon blacks and silica), resins (such as one or more hydrocarbon resins selected from coumarone-indene resins, petroleum hydrocarbon resins, terpene resins, styrene / α-methylstyrene resins, terpene phenolic resins, rosin-derived resins, and copolymers and / or mixtures thereof), accelerators, anti-degradants, oils, liquid diene polymers, coupling agents (such as carbon black coupling agents and / or silanes), sulfur donors, and sulfur. Liquid herein means that the material is in a liquid state at 23 °C. The composition can be a sulfur-curable or sulfur-cured rubber composition. Optionally, the elastomeric composition, such as a rubber composition, can be fiber-reinforced.

[0067] In yet another embodiment, the elastomeric composition or rubber composition comprises 100 phr of rubber, which rubber comprises one or more of natural rubber, synthetic polyisoprene, polybutadiene rubber, and styrene-butadiene rubber. Preferably, the composition comprises at least 50 phr of natural rubber (such as 50 phr to 100 phr of natural rubber), and optionally comprises from 0 phr or 5 phr to 50 phr of polybutadiene rubber. Additionally, the elastomeric or rubber composition comprises fillers, preferably comprising carbon black and / or silica. For example, such fillers can be in the range of 20 phr to 150 phr, preferably in the range of 30 phr to 90 phr. Preferably, such fillers mainly comprise carbon black. The elastomeric or rubber composition can also comprise 1 phr to 40 phr of resin, preferably including phenolic resin. Additionally, the elastomeric or rubber composition can comprise 1 phr to 30 phr of oil, preferably 1 phr to 20 phr of oil. Finally, the elastomeric or rubber composition generally can comprise 1 phr to 15 phr of anti-degradant, 0.5 phr to 10 phr of accelerator, 0.1 phr to 10 phr of zinc oxide, and 0.5 phr to 10 phr of sulfur. Additional components can also be present.

[0068] In yet another embodiment, the cord reinforcement is selected from one or more of the following: i) at least one cord, ii) at least one cord reinforcement tape, and iii) at least one fabric comprising cords. In one option, the cord reinforcement comprises or consists of at least one cord. Preferably, the cord is one of a multifilament cord and a monofilament cord. In another option, the cord reinforcement tape comprises a plurality of substantially parallel cords, which are optionally embedded in a polymer composition (such as a resin composition) and / or joined by a polymer composition to form a tape, and the polymer composition may comprise one or more of polyester, vinyl ester, polyurethane, and epoxy resin. In another option, the fabric may comprise a plurality of substantially parallel, preferably interconnected cords. Optionally, these cords may form the warp and / or weft of the fabric.

[0069] In yet another embodiment, the cord reinforcement, particularly one or more cords in the cord reinforcement, comprises or consists of one or more of textile materials, glass fiber materials, carbon fiber materials, boron fiber materials, basalt fiber materials, plant-based materials, and combinations of these materials. Optionally, the plurality of cords comprises different materials and / or is a hybrid cord of these different materials. Optionally, the plant-based materials comprise one or more of cotton, hemp, flax, sisal, and bast.

[0070] In yet another embodiment, the cord reinforcement, particularly one or more cords in the cord reinforcement, comprises or consists of textile materials selected from one or more of polyester (preferably PET), polyamide (preferably PA-6, PA-6,6, such as Nylon TM , aramid / aromatic polyamide), and rayon. Optionally, one or more of these materials may be recycled materials. Optionally, the plurality of cords comprises different materials and / or is a hybrid cord of these different materials.

[0071] In yet another embodiment, the cord reinforcement (particularly one or more cords in the cord reinforcement) comprises or consists of metal (such as steel or brass-coated steel).

[0072] In another embodiment, the cord reinforcement provided herein is one of a monofilament or multifilament cord. For example, the (maximum) diameter of the cord (measured perpendicular to the extension of the cord in the spoke) may be in the range of 0.01 mm to 2 mm, preferably in the range of 0.01 mm to 1 mm.

[0073] In yet another embodiment, when the cord reinforcement is applied to the first polymer composition layer, the first polymer composition layer is solid.

[0074] In yet another embodiment, the first mold member substantially has a prismatic shape and is wrapped with a first polymer composition layer on three circumferentially adjacent sides, wherein the method further comprises at least one of the following steps:

[0075] Providing an additional mold member that substantially has a prismatic shape and is wrapped with an additional polymer composition layer (the same as or different from the first and / or second polymer compositions) on three circumferentially adjacent sides, wherein each of the first mold member and the additional mold member is arranged with edges pointing towards each other and / or parallel to each other; and

[0076] Applying a cord reinforcement to at least one side of the first mold member wrapped with the first polymer composition layer and / or applying a cord reinforcement to at least one side of the additional mold member wrapped with the additional polymer composition layer.

[0077] Preferably, the prismatic shape is a triangular prism shape, or in other words, a prismatic shape having a triangular base. The corners of the triangle or triangular surface may optionally be curved.

[0078] In another embodiment, the step of providing the first mold member covered with the first polymer composition layer includes the sub-steps of preforming and / or overmolding the first polymer composition layer on the first mold member. Optionally, the corresponding steps may be applied to other / additional layers and respective mold members mentioned herein.

[0079] In another embodiment, the first polymer composition layer includes a pre-step of molding the first polymer composition layer in a separate mold system and then placing the first polymer composition layer on the first mold member.

[0080] In yet another embodiment, a plurality of spaced-apart portions of the cord reinforcement (or in other words, of the same cord reinforcement) are applied to the first polymer composition layer. Preferably, the cord reinforcement is one of the cord reinforcement belts and cords herein.

[0081] In yet another embodiment, the portions of the cord reinforcement applied to the first polymer composition layer are applied side by side to the first polymer composition layer, for example, applied in grooves arranged side by side in the first polymer composition layer.

[0082] In yet another embodiment, the (adjacent) portions of the cord reinforcement applied side by side are spaced apart from each other, or in other words, are spaced apart.

[0083] In yet another embodiment, the spoke includes or has a substantially X-shaped cross-section. Preferably, the cross-section extends in a plane parallel to the tire equatorial plane or parallel to the circumferential center line of the tire, which is known to those skilled in the art.

[0084] In yet another embodiment, the spoke comprises a substantially X-shaped cross-section having a pair of upper legs, a pair of lower legs, and an intersection portion connecting the pair of upper legs and the pair of lower legs, wherein, optionally, a first mold member is disposed between the pair of upper legs to at least partially define the upper legs on the inner side, and an additional mold member is disposed between the pair of lower legs to at least partially define the lower legs on the inner side. Alternatively, the method further comprises the step of providing one or more additional mold members facing the first mold member and the additional mold member to define the upper legs and the lower legs on the outer side (of the spoke and / or its legs).

[0085] In yet another embodiment, the method further comprises the step of removing the first mold member and optionally the second and / or additional mold members after overmolding. In other words, the first polymer composition layer and preferably the additional polymer composition layer become part or an integral part of the spoke. Additionally, or alternatively, the first mold member and optionally the second and / or additional mold members are removed or separated without separating the polymer composition layer from the spoke including these layers.

[0086] In yet another embodiment, the support structure comprises from 4 to 100 spokes, preferably from 20 to 70 spokes, or even more preferably from 30 to 70 spokes.

[0087] In a second aspect, the present invention relates to a method of manufacturing a support structure for a non-pneumatic tire, the support structure comprising at least one X-shaped and cord-reinforced polymer composition spoke, wherein the X-shaped spoke has a pair of upper legs and a pair of lower legs connected by an intersection portion. The method comprises the step of providing a mold comprising mold members, the mold members comprising i) a first prismatic mold insert (or member) for defining the inner surface of the X-shaped spoke between its upper legs, ii) a second prismatic mold insert (or member) for defining the inner surface of the X-shaped spoke between its lower legs, and iii) at least one additional mold member for defining the outer surface of the X-shaped spoke, the outer surface being substantially opposite to the inner surface defined by the first and second mold inserts, wherein at least one mold member (or a plurality or a majority of the mold members) is at least partially covered by at least one polymer composition layer. Further method steps include applying a cord reinforcement to the polymer composition layer, and injection molding an additional polymer composition onto the cord reinforcement and the polymer composition layer to wrap (or enclose) the cord reinforcement with or by the additional polymer composition and the polymer composition layer.

[0088] Similar to the first aspect, the method according to the second aspect provides an advanced method of providing a cord-reinforced spoke for a non-pneumatic tire support structure. In particular, if desired, a cord reinforcement can be provided in a central portion with respect to the spoke thickness, such as in one or more legs of the spoke. In other words, the present invention allows for the advanced and / or convenient positioning of one or more cord reinforcements in the manufactured spoke.

[0089] In one embodiment, at least a portion of the polymer composition layer includes at least one groove extending substantially parallel to and / or along the leg of the spoke, wherein the cord reinforcement is optionally applied to the polymer composition layer in the groove to restrict movement of the cord reinforcement perpendicular to the groove. In one option, the cord reinforcement is a cord or a cord-reinforced tape.

[0090] In another embodiment, the cord reinforcement extends at least through one of the lower legs, the cross-section, and at least one of the upper legs. By having the (same) cord reinforcement extend through both legs and the cross-section, a particularly durable spoke can be provided.

[0091] In yet another embodiment, the polymer composition layer is provided as an overmolded sleeve circumferentially surrounding a corresponding mold insert.

[0092] In yet another embodiment, at least one additional mold member has a substantially hexagonal cross-section to optionally define the adjacent profiles of two adjacent spokes. Optionally, the additional mold member has curved edges and / or corners.

[0093] In a third aspect of the present invention, the present invention relates to a method of manufacturing a non-pneumatic tire, the non-pneumatic tire comprising a radially outer circumferential tread band (optionally including one or more of a radially outer tread portion and a radially inner shear band), a radially inner hub portion, and a circumferential support structure for supporting the radially outer circumferential tread band on the radially inner hub portion. The support structure includes a circumferential and radially outer ring portion (adjacent the tread band), a circumferential and radially inner ring portion (adjacent the hub portion), and a plurality of spokes disposed circumferentially and arranged and / or extending between the radially outer ring portion and the radially inner ring portion, preferably so as to support the radially outer ring portion on the radially inner ring portion. The method includes providing a mold for molding at least one circumferential segment or sector segment of the circumferential support structure, wherein the mold includes a radially outer mold ring member for molding the radially outer side of at least one circumferential segment or sector segment of the radially outer ring portion, and a radially inner mold ring member for molding the radially inner side of at least one circumferential segment or sector segment of the radially inner ring portion, and mold inserts or members for molding the spokes among the plurality of spokes located between the mold ring members, wherein most of the mold inserts and / or members are at least partially covered by a polymer composition layer. The method further includes the step of applying a cord reinforcement to the polymer composition layer (or at least a portion thereof), wherein the cord reinforcement strengthens and / or connects the plurality of circumferentially arranged spokes to be molded; and injection molding an additional polymer composition onto the cord reinforcement and the polymer composition layer to wrap the cord reinforcement with the additional polymer composition and the polymer composition layer.

[0094] Thus, the entire circumferential support structure and / or its circumferential sector segments can be manufactured, including a plurality of cord-reinforced spokes. Such a manufacturing process can be implemented on a large scale and / or cost-effectively.

[0095] In one embodiment, the cord reinforcement extends through a plurality of circumferentially adjacent spokes and preferably extends from one circumferential end portion of the sector segment of the molded support structure to the other circumferential end portion of the sector segment of the molded support structure.

[0096] In another embodiment, the cord reinforcement or cord reinforcements are applied to the polymer composition layer within an assembled mold. Alternatively, the cord reinforcement is applied (or cord reinforcements are applied) to the polymer composition layer on a mold insert, and subsequently the mold insert is optionally inserted into the radially outer mold ring member and the radially inner mold ring member.

[0097] In yet another embodiment, the cross portion is arranged to be closer to the hub portion in the radial direction than to the radially outer ring portion, and / or the radially inner leg is shorter than the radially outer leg.

[0098] In yet another embodiment, one or more spokes include or have a cross-section of one or more of the following shapes in a plane parallel to the tire equatorial plane: X-shaped, V-shaped, C-shaped, I-shaped, H-shaped, O-shaped, S-shaped, Y-shaped, semi-X-shaped, and one or more bent and kinked shapes / forms of the above shapes. Preferably, the shape is X-shaped, such as a straight or bent X-shape. Another preferred shape is semi-X-shaped, particularly corresponding to an X-shape that is substantially cut radially. Shapes such as angled bracket-shaped or chevron-shaped can also be mentioned, where the kink thereof is not necessarily located at the radial center of the shape.

[0099] It should be emphasized that the above aspects and their embodiments and / or features mentioned herein can be combined with each other.

[0100] Figure 1 A preferred embodiment of the non-pneumatic tire 100 according to the present invention is shown, or in other words, the non-pneumatic tire 100 manufactured according to an embodiment of the method of the present invention. The tire 100 includes a tread band 110 having a radially outer tread portion 111 and a radially inner shear band 112, a radially inner hub portion 160, and a support structure 140 that supports the tread band 110 on the hub portion 160. In addition, the support structure 140 extends circumferentially around the axis of the tire 100 and includes a plurality of spokes 130 in the circumferential direction. In this embodiment, the spokes 130 have a bent, or in other words, a curved X-shape. The shear band 112 itself is known to those skilled in the art of non-pneumatic tires and typically includes a plurality of stacked rubber composition layers extending circumferentially. At least some of these layers are typically reinforced by cords.

[0101] Figure 2 A schematic cross-section of the spoke 130 is shown, which is cord-reinforced by a cord 150. The spoke 130 includes a pair of radially inner legs 132, a pair of radially outer legs 131, and a cross portion 133 that connects the pair of legs 131, 132 to each other. In addition, the shown spoke 130 has a radially inner head 137 and a radially outer foot 136. As shown, each pair of legs 131, 132 can be connected by respective connecting portions 134, 135 in their respective feet 136 or heads 137. As Figure 2It can be seen that the cord 150 extends within the spoke 130 in a Z-shaped pattern without extending beyond the surface of the spoke. In other words, the cord 150 is completely covered by the polymer composition of the spoke 130, which preferably comprises a thermoplastic elastomer (such as a thermoplastic polyester elastomer) or a rubber composition. In particular, the cord 150 winds through the spoke 130 between its radially inner head 137 and its radially outer foot 136. In another embodiment (not shown), the same cord or cord reinforcing band may wind through the same spoke multiple times, for example, between the head and the foot of the spoke. In another alternative, it is also possible for multiple cords or cord reinforcing bands to extend through the spoke. Additionally, or alternatively, another option is to have one or more cords, cord reinforcing bands, or fabrics including cords extend through multiple adjacent spokes.

[0102] In several embodiments and / or figures herein, for better orientation, the circumferential direction c, the axial direction a, and the radial direction r are indicated. The circumferential direction c is perpendicular to the axial direction a. The same applies to the radial direction r. The axial direction a is parallel to the rotational axis of the tire. These directions mentioned herein are not necessarily limited to a specific orientation of a given direction, unless otherwise specified herein.

[0103] Figure 3 Another embodiment of an X-shaped spoke 230 is shown, or in other words, including an X-shaped cross-section having a pair of radially inner straight legs 232, a pair of radially outer straight legs 231, which are connected by a cross-section 233, and including a cord 250 wound between the radially inner head 237 and the radially outer foot 236 of the spoke 230. The radially inner ends of the legs 232 are connected by a radially inner connecting portion 235, and the radially outer ends of the spokes 231 are connected by a radially outer connecting portion 234. Again, the cord 250 is completely enclosed within the material of the spoke 230. In other words, as shown in this cross-section, it is not visible on the surface of the spoke 230. It is noted that a pair of radially inner legs can also be described as a pair of radially upper legs and a pair of radially outer legs can be described as a pair of radially lower legs, respectively. In this embodiment, the cord 250 passes through each leg 231, 232 of the spoke 230.

[0104] Figure 4 Method steps 10, 20, 30, 40 for manufacturing or fabricating mold members (in particular mold inserts 1, 3) are shown, the mold members being used for manufacturing Figure 3The spokes 230 already shown in []. In step 10, two mold inserts 1, 3 are provided, each mold insert having a prismatic shape and showing a substantially triangular cross-section. In step 20, these mold inserts 1, 3 are placed or mounted into corresponding mold members 2, 4, which each have cavities 7, 8 for receiving a respective one of the mold inserts 1, 3 and forming a gap between the walls of the respective mold insert 1, 3 and the respective mold member 2, 4. In a further method step 30, the gap formed between the mold inserts 1, 3 and the corresponding mold members 2, 4 is filled with a polymer composition. In particular, the polymer composition is injection molded into the gap, thereby forming a respective one of the polymer composition layers 11, 13. Preferably, the polymer composition is a thermoplastic polyester elastomer or a rubber composition. Thereafter, in step 40, the mold inserts 1, 3 are removed from the mold members 2, 4 (or vice versa), such that each mold insert 1, 3 is covered with a polymer composition layer 11, 13.

[0105] As further shown in method step 50, according to Figure 5 the embodiment of [], the mold inserts 1, 3 (preferably manufactured according to the method steps shown in Figure 4 []) are stacked on top of each other, with two of their edges pointing towards each other. In addition, the inserts 1, 3 still carry the polymer composition layers 11, 13. The cord 250 is wound around these layers 11, 13 covering the inserts 1, 3 and passes through the gap between the two inserts 1, 3. In a further method step 60, the mold inserts 1, 3 covered with the polymer composition layers 11, 13 and carrying the cord 250 are inserted into a mold member 6, which defines the outer shape of the X-shaped spoke to be molded. In other words, the mold member 6 includes a cavity 5 having the outer shape of the spoke 230 to be molded. In step 70, the gap between the mold member 6, the polymer composition layers 11, 13, and the cord 250 is filled and / or injection molded with a second polymer composition, where the second polymer composition flows into the gap and, in the current non-limiting embodiment, is the same as the polymer composition forming the first polymer composition layers 11, 13. Thus, in step 70, the spoke 230 is molded or formed, which includes the cord 250 embedded, or in other words coated or enclosed, in the polymer composition. In step 80, the spoke 230 is removed from the mold member 6, for example after cooling. In addition, the inserts 1, 3 are also separated from the first polymer composition layer that has become part of the spoke 230, in particular pulled out.

[0106] Figure 3 and Figure 5 the embodiment shown in [] provides a spoke 230 with a cord 250 wound between the head and the foot of the spoke 230. Preferably, the cord can be wound multiple times between such a head and a foot of the spoke. InFigure 6 In an embodiment, an embodiment of a manufacturing method is shown, which provides two mold inserts 1', 3', which are respectively covered by polymer composition layers 11', 13', wherein the cord 250' is wound multiple times between the head and the foot of the spoke to be molded (i.e., applied to the polymer composition layers 11', 13'). For example, the two mold inserts 1', 3' can be fixed in place, and the cord 250' can be wound around the inserts 1', 3' covered by the polymer composition layers 11', 13', and these mold inserts 1', 3' (which can also be referred to as mold members) can be inserted into the cavity 5' of a complementary or corresponding mold member 6', and the mold member 6' defines the outer shape of the spoke to be molded. This arrangement of the cord 250' wound multiple times around the spoke helps to provide a more durable spoke. In addition, arranging the cord 250' on the polymer composition layers 11', 13' ensures that the cord 250' is not exposed on the surface of the spoke after demolding.

[0107] Figure 7 Another preferred option according to a preferred embodiment of the present invention is shown, wherein the mold member or mold insert 3'' again includes a polymer composition layer 13'' covering the outer surface of the mold insert 3''. In addition to the design of the similar mold inserts already shown in the previous figures described, according to Figure 7 the mold insert 3'' includes a plurality of preferably parallel grooves 23''. These grooves 23'' can be used to position one or more cords, or in other words, one or more segments of such one or more cords, in the grooves 23''. This allows for better control of the position of the cords in the spoke to be molded. In particular, the movement of the cords extending transversely to the grooves 23'' can be restricted.

[0108] Figure 8 A circumferential segment or sector segment 340 of a support structure is shown, which includes a radially inner circumferential ring portion (or in other words a segment or sector segment) 345 and a radially outer circumferential ring portion (or in other words a segment or sector segment) 344, which are connected by a plurality of spokes 330, for example, six spokes 330 in this case, each spoke having an X-shaped cross-section. A plurality of such sector segments 340 can be circumferentially combined or applied to provide a full-circumference support structure for a non-pneumatic tire.

[0109] Figure 9 An embodiment of a mold for manufacturing the sector segment 340 (already shown as Figure 8 shown) of the support structure is provided. Figure 9 A non-limiting embodiment of the shown mold includes a plurality of mold members or inserts 301, 303, 307, which are covered by corresponding polymer composition layers 311, 313, 317. In addition, these mold members 301, 303, 307 are shown installed in a cavity 305 formed by one or more mold members 308, 309. For simplicity,Figure 9 The mold members 308, 309 shown in [Fig.] are integrally formed, but they may also comprise or consist of a plurality of separate mold members forming the cavity 305. In addition, the inner surface of the mold member 308 facing the cavity 305 is adapted to form or mold the radially inner side of the ring portion 345 to be molded. The mold member 309 is adapted to form or mold the radially outer side of the radially outer ring portion 344 to be molded. According to this embodiment of the present invention, the mold members 301, 303, 307 are each covered with a layer of polymer composition. However, it may not be the case that all mold members are covered with a layer of polymer composition, for example, depending on the desired cord winding pattern on these members. In addition, or as an alternative, another option is that the surface of one or more of the mold members 308, 309 is also covered with a layer of polymer composition( Figure 9 not shown in [Fig.]).

[0110] Similar to Figure 5 the embodiment shown, at least one cord or, for example, a cord-reinforced tape can be wound around one or more of the mold inserts 301 and 303. There are various options for providing or applying one or more cord reinforcements on the mold members, some of which are further shown in Figure 10 and 11 [Fig.].

[0111] Figure 10 Fig. shows Figure 8 already shown in [Fig.] and schematically cross-sectioned a support structure molded with the mold shown in Figure 9 [Fig.]. According to Figure 10 the embodiment, two cords 350, 350' have been wound multiple times between the radially inner ring portion 345 and the radially outer ring portion 344. Each of the cords 350, 350' extends through each spoke, in particular through a radially inner leg, the cross-section of the respective spoke 330, and a radially outer leg. The two cords 350, 350' cross each other at the cross-section of the spoke 330. This winding pattern of the cords 350, 350' provides a very durable fan-shaped segment 340 of the support structure. In addition, the cords 350, 350' are completely encapsulated in the polymer composition of the spoke 330. Optionally, the cords 350, 350' are wound through a full-circumference ring portion (not shown). Preferably, the cords 350, 350' are axially separated from each other at least at the cross-section of the spoke 330. Similarly, in another embodiment (not explicitly shown), one or more cord-reinforced tapes can be wound in the fan-shaped segment of the support structure, as shown for the cords in Figure 10 [Fig.].

[0112] Figure 11 Fig. shows another schematic cross-section of the fan-shaped segment of the support structure, which is similar to Figure 8 and 10sector segments, but with different preferred cord winding patterns and cord numbers. In particular, the shown sector segment 440 of the support structure includes a radially inner ring portion 445 and a radially outer ring portion 444, which are interconnected by a plurality of spokes 430 arranged circumferentially so as to support the radially outer ring portion 444 on the radially inner ring portion 445. Compared with the previously described embodiments, Figure 11 The embodiment of includes seven separate cords 450, 451, 452, 453, 454, 455, 456. Each of the cords 451, 452, 453, 454, and 455 interconnects two circumferentially adjacent spokes 430. In particular, in this non-limiting embodiment, such a cord (e.g., cord 451) can be wound from the radially outer / inner ring portion through a radially outer adjacent leg of the spoke, through the crossing portion of the spoke, further into the radially inner / outer leg of the same spoke and into the radially inner / outer ring portion. From there, the same cord is further wound around the radially inner / outer leg of the adjacent spoke, further through its crossing portion and the radially outer / inner leg of the same spoke, and finally back to the radially outer / inner ring portion, where the two ends of the cord are optionally facing each other. It should be emphasized that such a cord (e.g., cord 451) can be wound through the sector segment of the support structure multiple times in the axial direction in order to further strengthen two adjacent spokes 430 (especially also in the axial direction). Similarly, in another embodiment, a cord reinforcing band can be used instead of the cords 450, 451, 452, 453, 454, 455, 456.

[0113] Although not shown in the embodiments herein, another option is to arrange multiple rows of circumferential spokes side by side axially, such as two rows, three rows, or four rows. From one row to another, the circumferential position of such spokes can be the same as that of the adjacent row or offset in the circumferential direction.

[0114] The mold, mold insert, and / or mold member are preferably provided with one or more high-temperature resistant materials, such as having a melting point higher than 200 °C, preferably higher than 300 °C. Plastic, ceramic, or metal materials are non-limiting examples of such mold materials.

[0115] In summary, the present invention provides advanced manufacturing methods for cord-reinforced support structures and / or their cord-reinforced spokes for non-pneumatic tires. These methods and their optional embodiments provide effective ways to control the cord reinforcement or cord positioning and / or can help avoid the cord reinforcement from appearing on the outer surface of the support structure or spokes. In addition, these methods are applicable to the mass production of cost-effective support structures and / or spokes.

[0116] In accordance with the description provided herein, the present invention may be varied. Although certain representative embodiments and details have been shown for the purpose of illustrating the present invention, those skilled in the art should understand that various changes and modifications can be made thereto without departing from the scope of the present invention. Accordingly, it is to be understood that changes may be made to the specific embodiments described, which will fall within the full scope of the present invention as defined by the following appended claims.

Claims

1. A method of manufacturing a support structure for a non-pneumatic tire, the support structure comprising at least one cord-reinforced polymer composition spoke, the method comprising the steps of: providing a first mold member at least partially covered by a layer of a first polymer composition; applying at least one cord reinforcement to the first polymer composition layer; and A second polymer composition layer is overmolded onto the first polymer composition layer to enclose the cord reinforcement between the first polymer composition layer and the second polymer composition layer and obtain at least a portion of a cord-reinforced polymer composition spoke. 2 . The method according to claim 1 , wherein the first polymer composition layer comprises at least one groove, and wherein the cord reinforcement is applied to the first polymer composition layer in the groove.

3. The method of claim 1 , wherein the first mold member is a mold insert, and the method further comprises the steps of: providing at least one second mold member, forming a gap between the first polymer composition layer on the mold insert and the second mold member, and in, The step of overmolding the second polymer composition layer includes injecting the second polymer composition into the gap to form the second polymer composition layer.

4. The method of claim 1, wherein the first mold member is at least partially encapsulated by a layer of the first polymer composition.

5. The method according to claim 4, wherein the first mold member has substantially a prismatic shape which is wrapped with a layer of the first polymer composition on three circumferentially adjacent sides.

6. The method of claim 1, wherein the first polymer composition and the second polymer composition comprise one or more of an elastomeric composition and a thermoplastic polymer.

7. The method of claim 1, wherein the cord reinforcement comprises at least one cord comprising one or more of a textile material, a glass fiber material, a carbon fiber material, a boron fiber material, a basalt fiber material, a plant-based material, and combinations of these materials.

8. The method of claim 1, wherein the first polymer composition layer is solid when the cord reinforcement is applied to the first polymer composition layer.

9. A method of manufacturing a support structure for a non-pneumatic tire, the support structure comprising at least one X-shaped and cord-reinforced polymer composition spoke, wherein the X-shaped spoke has a pair of upper legs and a pair of lower legs connected by a cross section, wherein the method comprises the steps of: A) providing a mold comprising a mold member, the mold member comprising i) a first prismatic mold insert defining an inner surface of the X-shaped spokes between upper legs thereof, ii) a second prismatic mold insert defining an inner surface of the X-shaped spokes between lower legs thereof, and iii) at least one additional mold member defining an outer surface of the X-shaped spokes, the outer surface being substantially opposite the inner surface defined by the first and second mold inserts, wherein at least one mold member is at least partially covered by at least one layer of a polymer composition; B) applying a cord reinforcement to the polymer composition layer; as well as C) injection molding a further polymer composition onto the cord reinforcement and the polymer composition layer, thereby wrapping the cord reinforcement with the further polymer composition and the polymer composition layer.

10. A method of manufacturing a non-pneumatic tire comprising a radially outer circumferential tread band, a radially inner hub portion and a circumferential support structure supporting the radially outer circumferential tread band on the radially inner hub portion, wherein: The support structure comprises a circumferentially and radially outer ring portion, a circumferentially and radially inner ring portion, a plurality of cord-reinforced polymer composition spokes disposed in the circumferential direction and arranged between the radially outer ring portion and the radially inner ring portion, wherein the method comprises the steps of: Providing a mold for molding at least one circumferential sector of a circumferential support structure, the mold comprising: a radially outer mold ring member for molding a radially outer side of at least one circumferential sector of the radially outer ring portion; a radially inner mold ring member for molding a radially inner side of at least one circumferential sector of the radially inner ring portion; and a mold insert for molding a spoke of a plurality of spokes located between the mold ring members, wherein a majority of the mold insert is covered by a layer of a polymer composition; applying a cord reinforcement to at least portions of the polymer composition layer, wherein the cord reinforcement reinforces and connects the plurality of circumferentially disposed spokes to be molded; and The additional polymer composition is injection molded onto the cord reinforcement and the polymer composition layer, thereby wrapping the cord reinforcement with the additional polymer composition and the polymer composition layer.

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