HK1189197B - Non- pneumatic tire - Google Patents

Abstract

A tire (1) comprises a rubber tread portion (2) and a truss ring (3), wherein the rubber tread portion (2) extends in circumferential direction of the tire (1) and is provided for contacting a ground surface, and the truss ring (3) contacts and extends along the tread portion (2) for supporting the vehicle on the tread portion (2), and is composed of truss members (4) which form two circumferential chords (5, 6) concentrically positioned with respect to the tread portion (2) and a truss web (7) interconnecting the chords (5, 6). The truss members (4) are made of a truss member material comprising rubber and having an E modulus of between 4 - 18 MPa.

Description

Non-pneumatic tire

Technical Field

The present invention relates to a tyre according to the preamble of the first claim.

Background

It is known that the safety of a vehicle (either while driving or during a stop) can be improved by avoiding the following situations: such a pneumatic tire of a vehicle suddenly loses its support performance due to, for example, leakage of the pneumatic tire (such leakage causes air of the pneumatic tire to suddenly leave the tire). It is also known to inflate an inflatable tire with liquid polyurethane instead of air. After curing of the polyurethane inside the tyre, the tyre provides good support properties for the vehicle, both while driving and during standstill, respectively called dynamic and static properties in the context of the present application. Furthermore, when the tyre is punctured, a sudden loss of the support properties of the tyre is avoided, since the polyurethane is cured and cannot leave the tyre through the split. However, liquid polyurethane used to fill tires is expensive, has ecological problems, and can still present a safety hazard if not working properly.

While a completely solid tire can meet all of the requirements of various safety aspects, a completely solid tire often fails to achieve the desired dynamic performance.

A further alternative, which does not require liquid polyurethane but avoids a sudden loss of support properties to increase safety and provides improved dynamic performance relative to an all solid tire, is for example sold by MICHELIN under the name tire. The tire includes a rubber tread portion extending in a circumferential direction of the tire. The tread portion is configured to contact the ground. The tire further includes a frame ring made of a different material, such as polyurethane, polyamide, or metal, integrally formed with the metal rim. The truss ring contacts and extends along the tread portion to support the vehicle on the tread portion, and is made of truss members and truss webs, the truss members forming two circumferential chords, the two circumferential chords being concentrically located with respect to the tread surface, and the truss webs interconnecting the chords.

However, such a tire is difficult to produce because the material of the rubber tread portion and the material of the frame member are significantly different. Thus, different layers need to be produced in different steps, which have a significant impact on the production process.

EP2177375a1, EP1894748a1 and EP2141030a1 describe tires having a rubber tread portion extending in the circumferential direction of the tire and intended to contact the ground surface and a carcass. The truss ring contacts and extends along the tread portion to support the vehicle on the tread portion, and is made of truss members made of two circumferential chords (concentrically positioned with respect to the tread portion) and a truss web (interconnecting the two chords). These frame members are made of a frame member material comprising rubber. EP2177375A1 describes that some frame members have an E modulus of between 7 and 20 MPa.

However, it has been found that these tires have inadequate dynamic and/or static performance.

Disclosure of Invention

It is therefore an object of the present invention to provide an alternative tyre which is easier to manufacture and which does not require filling with liquid polyurethane, but which is able to provide similar dynamic and/or static properties as tyres filled with cured polyurethane and which is also able to reduce the risk of sudden loss of support properties.

Furthermore, the frame member is made of a frame member material, which comprises rubber and has an E modulus between 4-18MPa and preferably between 6-8 MPa.

The connection between the tread portion and the frame web member is made easier when the tread portion is made of rubber and the frame web member also comprises rubber, when the tread portion and the frame member are made of rubber and polyurethane or another polymer, respectively, for example. It is also possible to manufacture the whole tyre from rubber, as is common for example with solid rubber tyres according to the state of the art, so that starting from a semi-finished tyre, the whole tyre can be manufactured from rubber using standard curing techniques in moulds. In such a case, in order to manufacture the tire according to the present invention, no significant changes need to be made to existing facilities used to manufacture rubber tires (more specifically, solid rubber tires).

Furthermore, it has been found that such a carcass component allows the manufacture of tyres having properties similar to those of the tyres inflated with polyurethane described above. However, the use of liquid polyurethane can be avoided.

In particular, it has been found that the radial deflection under load of such a tire is similar to that of the polyurethane-filled tire described above. Comparative tests have been carried out in which the radial deflection of the respective pneumatic tires, the tires filled with polyurethane and the solid tires are compared with the radial deflection of the tire according to the invention, all tires having a width of 13.00 and a diameter of 24, 13.00 and 24 being code-indicating ciphers in which 13.00 is 13.00 inches and 24 is 24 inches, 13.00 inches being above and below 330mm and 24 inches being above and below 610mm (generally designated 13.00-24). Radial deflection was measured according to standard SAE-J2704 at a nominal load of 6500 kg. The radial deflection of the pneumatic tire was 58.0mm, the radial deflection of the tire filled with polyurethane was 50.0mm, the radial deflection of the solid tire was 35.0mm, and the radial deflection of the tire according to the invention was 48.0 mm. From this comparison, it is evident that the tire according to the present invention is closest to a pneumatic tire and a polyurethane tire as compared with a solid tire. The values are also surprisingly similar to those of a tire filled with polyurethane, resulting in similar radial deflection without the need to fill the tire with polyurethane. Moreover, the values are close to those for the radial deflection of pneumatic tyres, with a reduced risk of sudden loss of support performance.

According to some preferred embodiments of the tyre, the frame member material is substantially rubber or even just rubber, thereby further improving the above-mentioned ease of manufacture.

According to some preferred embodiments of the tyre according to the invention, at the outer surface of the carcass ring, the ratio of the area of the carcass web parts to the area of the openings between the carcass web parts is between 30/70 and 70/30, preferably between 40/60 and 60/40, most preferably 60/40. It has been found that the ratio of the area of the frame web members at the outer surface of the frame ring to the area of the openings between the frame web members, also called the land/sea ratio, allows to further improve the dynamic and/or static performance of the tire. In particular, such a land/sea ratio provides the tire according to the invention with properties even more comparable to those of a pneumatic tire filled with polyurethane, as described above, when the frame component material has an E modulus between 4 and 18MPa, and more particularly when the E modulus is between 6 and 8 MPa.

The skeleton ring is arranged such that: the pairs of frame web members extend from opposite sides of the respective frame chord members to form a layer of adjacent triangular openings bounded by the frame members at a first outer surface of the frame ring, the openings extending toward and more preferably to a second outer surface of the frame ring opposite the first outer surface of the frame ring along the axis of rotation of the tire. It has been found that such an organization of the frame web components relative to the frame chord components further improves the dynamic and/or static performance of the tire. It has been found that the static performance of the tire is improved, in particular due to the presence of the triangular openings.

According to further preferred embodiments of the tire according to the present invention, the first opposing side is an opposing side of the respective truss chord member positioned closest to the circumferential chord of the tread portion with respect to the other circumferential chord, the first opposing side being positioned with respect to the tread pattern of the tread portion such that the respective first opposing side is located below the respective protrusion of the tread pattern. It has been found that such a positioning of the first opposite sides allows a good distribution of the load from the projection of the tread pattern to the carcass ring and allows to provide the tire with improved static and dynamic performances.

According to further preferred embodiments, one of the truss web member and the truss chord member of the pair of truss web members and the one truss chord member forming the triangular opening at the first outer surface of the truss ring delimits at least one angle of the triangular opening, which is smaller than the other angles of the triangular opening. By providing the carcass web members in such a way, the deformation of the carcass members under load characteristics can be controlled either during loading of the tire while running (dynamic loading) or during stopping (static loading), since such an angular carcass web member provides controlled load-deformation characteristics. In further preferred embodiments of the tyre according to the invention, the angle is between 30 ° and 70 °, thereby achieving a further improved control of the load deflection characteristics of the carcass component.

In other preferred embodiments of the tyre according to the invention, the respective triangular openings are uniform so as to provide a substantially uniform distribution of the load when subjected to static loads and a substantially continuous dynamic performance, i.e. a substantially continuous support of the vehicle by the tyre, while driving.

In further preferred embodiments of the tyre according to the invention, the triangular openings between the frame parts narrow from the first outer surface of the frame ring towards the second outer surface of the frame ring, and more preferably to the second outer surface of the frame ring. Such an opening is easier to form by curing the green tyre in a mould, since with an opening so formed it is easier to remove parts of the mould present in the opening. Furthermore, when material, such as ground material or dirt for example, rarely enters the opening, the narrowing shape of the opening allows the material to be pushed out of the opening when the framing members bounding the opening are subjected to bending, for example under dynamic loading.

In further preferred embodiments of the tire according to the invention, the triangular openings between the frame parts narrow stepwise. Such a stepwise narrowing can enhance the effect of pushing the material out of the opening. Without wishing to be bound by any theory, it is believed that this is caused by the stress of the material at the location of the step, which further weakens the attachment of the material to the framing member.

In further preferred embodiments of the tire according to the invention, the cross-section of the triangular opening at the first outer surface of the carcass ring gradually changes to a substantially circular cross-section at the second outer surface of the carcass ring. It has been found that such an arrangement provides a good balance between good dynamic performance and good static performance, since it has been found that the triangular form provides good static performance, while the substantially circular cross-section provides improved dynamic performance.

In a further development of the tire according to the invention, the tire comprises a first carcass ring of said carcass rings and a second carcass ring different from the first carcass ring, which carcass rings extend in the axial direction over a first length and a second length, respectively. The second frame ring may differ from the first frame ring, for example in position along the axis of the tire, for example when they are not adjacent to each other, when they have different frame members, different materials for the frame members, different dimensions of the frame members, different relative positions of the frame members with respect to each other, which lead for example to different land/sea ratios, etc., which lead for example to a phase difference of the periodicity of the occurrence of the frame members. Such a construction has been found to impart different properties to the tire under dynamic or static loading. It has been found that various embodiments can be developed for tires intended for different uses. Some examples are given below, which illustrate various possibilities.

Drawings

The invention is further explained in the figures and the description thereof.

Fig. 1a shows a schematic view of an embodiment of a tyre according to the invention.

Fig. 1b shows an exploded view of the tire according to fig. 1 a.

Fig. 2 shows a side view of a cross section of the tire shown in fig. 1 b.

Figure 3a shows a cross section of a detail of another embodiment of the tire different from that shown in the above figures.

Figure 3b shows a cross section of a detail of another embodiment of the tire different from that shown in the above figures.

Fig. 4 shows a detail of the tyre shown in fig. 1 a.

Fig. 5 shows a detail of the tyre shown in fig. 1 a.

Tire: 1

A tread portion: 2

Framework ring: 3

Frame components: 4

First circumferential chord: 5

Second circumferential chord: 6

A framework web: 7

Openings between truss web components: 8

A truss web component: 9

Truss chord member: 10

A first opposite side: 11

A second opposite side: 12

And (3) protrusion: 13

A first outer surface: 14

A second outer surface: 15

A first corner: 16

Auxiliary framework ring: 17

The middle part: 18

A first boundary side: 19

Second delimiting side: 20

Third delimiting side: 21

A second angle: 22

And a third angle: 23

First radius of curvature: 24

Second radius of curvature: 25

Third radius of curvature: 26

Fourth radius of curvature: 27

Fifth radius of curvature: 28

Sixth radius of curvature: 29

Detailed Description

Fig. 1a shows a tire 1, which tire 1 comprises a rubber tread portion 2, which rubber tread portion 2 extends in the circumferential direction of the tire 1 for contacting the ground. The tread portion 2 is preferably provided with a tread pattern having protrusions 13, as shown in fig. 5. The specific design of tread portion 2 is not critical to the present invention, however, and may also be determined by one skilled in the art. The tread pattern may, for example, be specifically arranged to run in wet and/or dry conditions, etc., or may be specifically arranged for the specific ground on which it is to be used.

The tyre 1 can be provided to be mounted on any known type of vehicle, such as for example but not limited to cars, trucks, etc.

The tyre 1 further comprises a carcass ring 3. The cage ring 3 contacts the tread portion 2 and extends therealong to support the vehicle on the tread portion 2. The frame ring 3 is made of frame parts 4. The frame member 4 forms two circumferential chords 5, 6. The circumferential chords 5, 6 are concentrically located relative to the tread portion 2. A truss web 7 interconnects the chords 5, 6. The framing members 4 making up the circumferential chords 5, 6 are called framing chord members 10, and the framing members 4 making up the framing web 7 are called framing web members 9. The circumferential chord 5 closest to the tread portion 2 is called the first chord 5, while the circumferential chord closest to the axis of rotation of the tyre 1 is called the second circumferential chord 6.

The material of the frame member has an E modulus between 4-18MPa, preferably between 4-10MPa, most preferably between 5 and 8MPa, like for example 5 MPa.

Preferably, the framing member material is rubber, more preferably the framing member material is rubber selected such that after vulcanization, the tread portion and the framing member form a substantially uniform, preferably uniform unit, such as, for example, when the materials of the framing member material and the tread portion are substantially the same.

The frame part 4 shown in fig. 4 and 5 has a substantially constant width at the outer surface 14 of the frame ring 3. This is however not critical for the invention and the width may vary, for example, along the length of the frame member 4.

The frame part 4 delimits an opening 8, as shown in the figure. The size and form of the openings are not critical to the invention as long as the carcass ring 3 is provided to support the vehicle on the tread portion, bearing in mind or contemplating similar dynamic and/or static properties as the tire filled with cured polyurethane. In this respect, best results are obtained for a tire wherein the ratio of the area of the frame web parts 9 at the outer surface of the frame hoop 3 to the area of the openings 8 between the frame web parts 9, i.e. the land/sea ratio, is between 30/70 and 70/30, preferably between 40/60 and 60/40, most preferably 47/53.

Preferably, the opening 8 is triangular and delimited by one truss chord member 10 and two truss web members 9, the two truss web members 9 extending from opposite sides 11, 12 of the truss chord member 10 and extending towards each other. This configuration is shown in detail in fig. 4 and 5.

More preferably, as shown in detail in the figures, the framing is a warren (warren) framing and the openings 8 are such that the layer of adjacent triangular openings 8 delimited by the framing members 4 is formed at the first outer surface 14 of the framing collar 3. Preferably, the opening 8 extends towards a second outer surface 15 of the carcass ring 3, which second outer surface 15 is opposite to the first outer surface 14 of the carcass ring 3 along the axis of rotation of the tyre 1, as shown in fig. 1 b. As shown in fig. 1b, the opening 8 may extend to the second outer surface 15. This is however not critical for the invention and the opening 8 may also extend partly through the frame ring 3, as shown for example in fig. 3a and 3 b.

Fig. 5 shows a preferred positioning of the protrusions 13 of the tread pattern of the tread portion 2 relative to the openings 8 of the carcass ring 3. In the embodiment shown, the opposite sides of the respective frame chord members 10 of the first circumferential chord 5 are positioned with respect to the tread pattern such that the respective first opposite sides 11 are positioned below the respective protrusions 13 of the tread pattern. Fig. 5 further shows the load distribution in such a tyre 1. However, depending on the desired characteristics for the tyre 1, the opening 8 may also be positioned below the protrusion 13, for example to provide a more resilient tyre 1, for example to provide greater comfort when used to support a vehicle for carrying passengers.

As can be seen from fig. 5, there are two concentric rows of triangular openings 8 equidistant from the axis of rotation of the tyre 1, the first row of openings 8 comprising respective truss chord members 10 of the first circumferential chord 5 and the second row of openings 8 comprising respective truss chord members 10 of the second circumferential chord 6. Preferably, as shown in fig. 5, the openings 8 of the first row are preferably substantially identical, or identical, to each other, and the openings 8 of the second row are congruent (consent), i.e. have substantially identical shape, more preferably substantially identical, or identical, to each other. It has been found that when the openings 8 of the first and second rows are respectively identical or even substantially identical, or identical, the tyre 1 provides a more uniform support during running.

Fig. 3a and 3b show that the opening 8, preferably the triangular opening 8, narrows from the first outer surface 14 towards the second surface 15, i.e. tapers towards the second surface 15 of the frame ring 3.

Fig. 3a and 3b show a cross section of the opening 8. The opening 8 shown in fig. 3a is substantially smooth. This is however not critical to the invention and can be determined by the person skilled in the art depending on the desired characteristics of the tyre 1, the ground on which the tyre 1 is to be used substantially, etc. Fig. 3b shows a further cross section of the opening 8, which narrows in a stepwise manner, i.e. tapers. This is however not critical for the invention and the opening 8 may taper continuously as shown in fig. 3 a.

Of the two openings 8 shown in fig. 3a and 3b, respectively, the cross-section of the triangular opening 8 at the first outer surface 14 of the framing collar 3 gradually changes to a substantially circular cross-section at the second outer surface 15 of the framing collar 3. This is however not critical to the invention and the cross-section at the second outer surface 15 of the framing ring 3 may have any shape deemed appropriate by the person skilled in the art. The opening 8 may for example have a tapered cross-section ending with a generally sharp tip, however, for fatigue life reasons, rounded edges are preferred.

Fig. 5 shows a detailed view of some of the openings 8 at the first outer surface 14 of the tyre 1. Each opening is delimited by delimiting sides which are part of the frame part 4. The curvature of the different delimited sides of the opening 8, expressed in terms of its radius of curvature, may be determined as a function of the desired deformation of the opening 8 under load, for example during use of the tyre 1, and may for example be infinite, positive, negative, etc. Fig. 4 shows in particular a triangular opening 8, which triangular opening 8 has a first delimiting side 19 and a second delimiting side 20, which first delimiting side 19 and second delimiting side 20 are both part of the framing web member 9, and a third delimiting side 21, which third delimiting side 21 is part of the framing chord member 10. The respective first, second and third radii of curvature 24, 25, 26 are the same for the respective first, second and third bounding sides 19, 20, 21. This is however not critical for the invention and the radius of curvature may also be directed outwards depending on the desired properties of the tyre 1.

Preferably, the absolute value of the radius of curvature is chosen between 100mm and 1500mm, more preferably between 300mm and 1300 mm. For example, a first radius of curvature 24, a second radius of curvature 25 and a third radius of curvature 26, which are the radii of curvature of the framing members of the openings of the first row 5, are 1226mm (framing web member with a first delimiting side 19), -304mm (framing web member with a second delimiting side 20) and 657mm (framing chord member with a third delimiting side 21), respectively, wherein a positive radius of curvature extends from within the opening 8 and a negative radius of curvature extends from outside the opening 8. The radius of curvature of the truss chord members 10 of the second row of openings 8 is-571 mm, the radius of curvature of the truss web members of the first row of openings adjacent to the truss web member 9 (which truss web member 9 provides the second delimiting side 20 of the first row of openings) is 304mm, and the radius of curvature of the other truss web members of the second row of openings 8 is-1245 mm, wherein a positive radius of curvature extends from within the openings 8 and a negative radius of curvature extends from outside the openings 8.

The delimiting sides 19, 20, 21, which intersect each other, enclose the corners 16, 22, 23. Preferably and as shown in fig. 4, one of the truss web members 9 and the truss chord members 10 of the pair of truss web members and the one truss chord member forming the triangular opening 8 at the first outer surface 14 of the truss ring 3 delimit at least one angle 16 of the triangular opening 8, which at least one angle 16 is smaller than the other angles of the triangular opening 8. This is however not critical to the invention and any other shape for the opening 8 may be used as deemed appropriate by the person skilled in the art. Preferably, the angle 16 is between 30 ° and 70 °, more preferably between 45 ° and 55 °, most preferably between 46 ° and 52 °. For example, the first, second and third angles of the openings of the second row of openings are each 46.9 °; 67.5 ° and 65.6 °, wherein the second angle is formed between two truss web parts 9 and the third angle is formed between a truss chord part 10 and one truss web part 9. For example, the first, second and third angles 16, 22, 23 of the openings of the first row of openings, respectively, are 51.3 °; 55.3 deg. and 73.4 deg., wherein the second angle is formed between two truss web members 9 and the third angle is formed between a truss chord member 10 and one truss web member 9.

Preferably, the corners 16, 22, 23 are rounded to avoid the occurrence of cracks in the framing web material due to stress build-up. The radius of curvature of the rounded corner is preferably between 10mm and 15mm, more preferably between 11mm and 12mm, most preferably 11.5 mm.

The length of the frame member 4, measured from those points where the bounding sides would intersect if the rounded corner were not present, is preferably between 50mm and 200mm, more preferably between 70mm and 110mm, most preferably between 80mm and 105 mm. For example, the length of the web part 4 of one opening 8 of the first row 5 of openings is 101.4mm (truss web part with a first delimiting side 19), 81.4mm (truss web part with a second delimiting side 20) and 102.9mm (truss chord part with a third delimiting side 21), respectively. The length of the truss chord members 10 of the second row of openings 8 is 85.8mm, the length of the truss web members of the first row of openings adjacent to the truss web members 9, which truss web members 9 provide the second delimiting side 20 of the first row of openings, is 81.4mm, and the length of the other truss web members of the openings 8 in the second row of openings is 100 mm.

Preferably, the width of the framing web member is between 10mm and 50mm, more preferably between 20mm and 40mm, most preferably between 25mm and 30mm, for example 28 mm.

Different parameters of the dimensions of the frame web member 4 and the opening 8 are selected according to the desired land/sea ratio and/or tire geometry.

Fig. 1b shows that the tyre 1 comprises a first and a second one 3, 17 of said frame rings, which extend over a first and a second length, respectively, along the axis of rotation of the tyre 1.

Fig. 1b also shows that the tyre 1 also comprises a disc 18, for example a rubber disc, which disc 18 extends a third length along the axis of rotation of the tyre 1. The disc 18 also contacts the tread portion 2 about the axis of rotation of the tyre 1 and extends along this tread portion 2 in order to support the vehicle on the tread portion 2. The disc 18 is clamped between the two frame rings 3, 17.

The length of the carcass loops 3, 17 extending along the axis of rotation of the tyre 1-the carcass loop width, and the length of the disc 18 extending along the axis of rotation of the tyre 1-the disc width, can be determined by the person skilled in the art depending on the envisaged performance of the tyre 1. Preferably, although not critical to the invention, the framing ring widths are substantially the same. In a first example, the disc width is 50% of the total width of the tyre 1, measured along the axis of rotation of the tyre 1, while the width of each carcass ring is respectively 25% of the total width of the tyre 1. In a second example, the frame ring width and the disc width are both one third of the total width of the tire 1.

However, such a configuration of the framing rings 3, 17 and the disc 18, if present, is not critical to the invention and other configurations are possible.

For example, more or less than two frame rings 3, 17 are possible in the tire 1. For example, the tire 1 may include one, three, four, five, six, seven, eight, etc. carcass rings. Each frame ring may be adapted to specific desired properties, which may be dynamic and/or static, by specifically adapting the form, size of the openings, by changing the frame member material, etc.

For example more or less than one disc 18 is possible in the tyre 1. For example, the tire 1 may include a number of disks that is zero, one, two, three, four, five, six, seven, eight, etc. Each disc may be tailored to specific desired properties, dynamic and/or static, by changing the material of the disc, etc.

In addition, the positioning of the different disks (if present at all) and of at least one of the rings 3 along the axis of rotation of the tyre 1 can be varied, so that one ring or disk can be positioned between two disks, between two rings, at the outer surface of the tyre 1, etc.

In addition, the positioning of the openings 8, delimited by the frame parts 4 of the respective frame rings 3, can be adapted to obtain a specific dynamic or performance.

In a first embodiment, not shown in the figures, the tyre comprises a single carcass ring 3. In a second embodiment, not shown in the figures, the tyre 1 according to the invention comprises two carcass rings 3, 17, the carcass ring width preferably corresponding to 50% of the overall width of the tyre. In a third embodiment, the tyre 1 comprises two discs between which the carcass ring 3 is clamped.

Claims (14)

1. A tyre (1) comprising a rubber tread portion (2) extending in a circumferential direction of the tyre (1) for contacting the ground, and a carcass ring (3) contacting and extending along the tread portion (2) for supporting a vehicle on the tread portion (2), which carcass ring (3) is made of a carcass member (4) forming two circumferential chords (5, 6) positioned concentrically with respect to the tread portion (2) and a carcass web (7) interconnecting the two circumferential chords (5, 6), wherein the carcass member (4) is made of a carcass member material comprising rubber and having an E modulus between 4-18MPa,

it is characterized in that the preparation method is characterized in that,

the carcass ring (3) is arranged such that pairs of carcass web parts (9) extend from opposite sides of respective carcass chord parts (10), forming a layer of adjacent triangular openings (8) delimited by the carcass parts (4) at a first outer surface (14) of the carcass ring (3), the openings (8) extending towards a second outer surface (15) of the carcass ring, which second outer surface (15) is opposite to the first outer surface (14) of the carcass ring (3) along the rotation axis of the tyre (1);

one of a pair of truss web members (9) of a triangular opening (8) and a truss chord member formed at the first outer surface (14) of the truss ring (3) and the truss chord member (10) delimits at least one angle (16) of the triangular opening (8), the at least one angle being smaller than other angles of the triangular opening (8); and is

The cross-section of the triangular opening (8) at the first outer surface (14) of the skeleton ring (3) gradually changes to a substantially circular cross-section at the second outer surface (15) of the skeleton ring (3).

2. Tyre (1) according to claim 1, characterized in that said frame component material is rubber.

3. Tyre (1) according to claim 1 or 2, wherein at the outer surface of the carcass ring (3) the ratio of the area of carcass web parts (9) to the area of openings (8) between the carcass web parts (9) is between 30/70 and 70/30.

4. Tyre (1) according to claim 1 or 2, wherein at the outer surface of the carcass ring (3) the ratio of the area of carcass web parts (9) to the area of openings (8) between the carcass web parts (9) is between 40/60 and 60/40.

5. Tyre (1) according to claim 1 or 2, wherein at the outer surface of the carcass ring (3) the ratio of the area of carcass web parts (9) to the area of the openings (8) between the carcass web parts (9) is 60/40.

6. A tyre (1) as claimed in claim 1 or 2, wherein the frame member (4) delimiting the triangular opening (8) is arranged such that: when deformed under load, one of the delimiting truss web parts (9) and the delimiting truss chord part (10) bend towards each other.

7. Tyre (1) according to claim 6, characterized in that during deformation under load one of the delimiting carcass web parts (9) bends towards the carcass chord part (10).

8. A tyre (1) as claimed in claim 1 or 2, wherein the first opposite sides (11) are opposite sides of the respective carcass chord member (10) located closest to the circumferential chord (5) of the tread portion (2) with respect to the other circumferential chords (6), the first opposite sides being located with respect to the tread pattern of the tread portion (2) such that the respective first opposite sides (11) are located below the respective protrusions (13) of the tread pattern.

9. Tyre (1) according to claim 1 or 2, wherein said at least one angle (16) is between 30 ° and 70 °.

10. Tyre (1) according to claim 1 or 2, wherein each triangular opening (8) of a row of triangular openings equidistant from the axis of rotation of the tyre (1) is uniform.

11. Tyre (1) according to claim 1 or 2, wherein said triangular openings (8) between said frame parts (4) narrow from said first outer surface (14) of said frame ring (3) to said second outer surface (15) of said frame ring (3).

12. A tyre (1) as claimed in claim 11, wherein said triangular openings (8) between said frame parts (4) are narrowed stepwise.

13. Tyre (1) according to claim 1 or 2, wherein the respective frame web component (9) has a substantially constant width at the first outer surface (14) of the frame ring (3).

14. Tyre (1) according to claim 1 or 2, wherein said tyre (1) comprises a first and a second one (3, 17) of said carcass loops, said first and second carcass loops extending axially over a first and a second length, respectively.