Pneumatic vehicle tire

Abstract

The invention relates to a radial pneumatic tire for a vehicle, comprising a shaped tread (1), a sidewall (3), a bead region (2) and a gas-tight inner layer (4) forming an inner side (4a) facing the interior of the pneumatic tire for the vehicle, ribs (6) formed on the inner layer (4), and sound absorbers (5), according to the invention, the ribs have been embossed by a tire bladder inserted into the interior of the pneumatic tire for vehicles during vulcanization of the tire in a tire heating mold, the sound absorber being applied in an annular manner around a circumferential area (4b) of the inner side (4a) opposite the tread (1). A groove (7) is formed by the tire bladder at least in a portion of a circumferential region (4b) of the inner layer (4a), to which the sound absorber (5) is applied.

Description

Field of the Invention

[0001] The present invention relates to a pneumatic vehicle tire having a meridian structure, the pneumatic vehicle tire having a shaped tread, sidewalls, bead regions and an airtight inner liner, ribs formed on the inner liner, and a sound absorber, the airtight inner liner forming an inner side facing the internal space of the pneumatic vehicle tire, the ribs having been imprinted in the inner liner by means of a heated bladder which is introduced into the interior of the tire during the vulcanization of the pneumatic vehicle tire in a tire heating mold, the sound absorber being arranged to extend in an annular manner over a circumferential region on the inner side opposite the tread. Background Art

[0002] It is known to introduce a foam ring into the interior of a tire in order to reduce the occurrence of noise emitted externally during the running or rolling of the tire and heard inside the vehicle. Thus, for example, DE 198 06 135 A1 discloses a method for producing a pneumatic vehicle tire having a sound-absorbing foam layer adhered to an inner liner, wherein the tire has been covered with the foam layer before vulcanization and the foam layer is chemically and / or mechanically bonded to the inner liner during vulcanization. In the case of the pneumatic vehicle tire known from DE 19750 229 A1, a closed-cell foam layer adhesively bonded to the inner side is located on the inner side of the tire.

[0003] In practice, the sound absorber is usually adhesively bonded to the inner side of the pneumatic vehicle tire over its entire surface area, and polyurethane gel is usually used. This view has been adopted until now, as only adhesive bonding over the entire surface area can ensure with sufficient certainty that the sound absorber will not undesirably become detached from the inner side of the pneumatic vehicle tire. In addition, this measure has been considered the simplest solution technically in terms of production. In this case, the entire inner side of the pneumatic vehicle tire opposite the tread is provided with an adhesive or binder, and then the sound absorber is adhesively attached to a circumferential portion in order to attach it to the inner side. For safety reasons, a relatively thick adhesive layer or binder layer has been used for the hitherto common adhesive bonding over the entire surface area, thereby increasing the weight of the pneumatic vehicle tire, while the large amount of binder required is economically disadvantageous. Summary of the Invention

[0004] The object on which the present invention is based is to optimize the adhesive bonding between the sound absorber and the pneumatic vehicle tire in the case of a pneumatic vehicle tire of the type mentioned at the beginning, while continuing to ensure the secure adhesive attachment of the sound absorber, and at the same time reducing the weight. The measures to be taken are intended to be technically easily implementable in terms of production.

[0005] According to the present invention, the set goal is achieved in the following manner: The recesses have been formed at least in a partial region of the circumferential region of the inner layer by means of the heating bladder, and the sound absorber is provided on this partial region.

[0006] Therefore, in addition to the ribs formed by the heating bladder during the vulcanization process of the vehicle pneumatic tire, recesses are also imprinted in the inner layer of the tire. These recesses increase the effective contact area or the adhesive bonding area in order to provide a sound absorber on the inner side of the vehicle pneumatic tire. If full surface area adhesive bonding is still carried out, the bonding of the sound absorber on the inner side of the vehicle pneumatic tire is improved, while at the same time, since a larger adhesive bonding area is available, less adhesive can be used. Depending on the design and arrangement of the recesses, it is also possible to dispense with the full surface area adhesive bonding of the sound absorber on the inner side of the vehicle pneumatic tire; the adhesive bonding can be carried out exactly in the region where the recesses are formed. Thus, on the one hand, expensive adhesives can be saved, and on the other hand, a reduction in the overall weight of the vehicle pneumatic tire can be achieved. Since the recesses are imprinted in a rib-like manner by means of the heating bladder, the present invention can be easily technically realized in terms of production. In the case of a preferred embodiment of the present invention, the recesses are formed in the central circumferential region of the inner layer without ribs. Specifically, in this region, the effect that can be achieved by the recesses, namely, increasing the contact area or the adhesive bonding area for providing a sound absorber, is particularly significant.

[0007] However, according to a further embodiment of the present invention, it can also be advantageous to form the recesses laterally from the central circumferential region of the inner layer without ribs. This measure can be taken additionally or as an alternative, and is particularly advantageous when a relatively wide sound absorber is to be provided on the inner side.

[0008] There are also many possibilities for forming the recesses according to the present invention on the inner side of the tire. Particularly advantageous are those designs that can save adhesive and nevertheless reliably and permanently bond the sound absorber to the inner side of the vehicle pneumatic tire. In one of these possibilities, the recesses are formed to extend at least substantially parallel to the ribs. In the case of a further embodiment, the recesses or parts of the recesses can be formed to extend between the ribs, or it can be provided that the recesses or parts of the recesses cross the ribs.

[0009] With respect to the path along which the recesses extend or within their scope, the recesses can be designed in many different ways as well. Thus, recesses extending along the circumferential direction of the tire can be provided, or alternatively, recesses extending along the axial direction can be provided. However, the recesses can also extend in a circular form or in some other way along an uninterrupted path, or in the case of a further design variant, the recesses extend in a waveform or zigzag form.

[0010] In a particularly reliable and thus also simple manner, grooves of specific dimensions can be embossed in the inner layer of a pneumatic vehicle tire. It is advantageous in this context if grooves having a width of 2 mm to 4 mm and a mutual spacing of 2 mm to 9 mm are embossed on the inner side of the inner layer. The depth of these grooves relative to the horizontal plane of the inner side of the inner layer is preferably 0.5 mm to 1 mm. Embossed grooves having a circular (e.g., semi-circular) cross-section are particularly simple. Description of the Drawings

[0011] Further features, advantages and details of the invention will now be explained in more detail on the basis of schematic drawings. In the drawings:

[0012] Figure 1 A cross-section through a pneumatic vehicle tire is shown,

[0013] Figure 2 A view of the circumferential part of a pneumatic vehicle tire is shown, in which a view of the inner side of the pneumatic vehicle tire is present, and

[0014] Figure 3 and Figure 4 A plan view of details of the inner side of a pneumatic vehicle tire with different design variants of the invention is shown. Detailed Description

[0015] Figure 1 A cross-section of a tubeless pneumatic vehicle tire having a meridian construction with a profiled tread 1, bead regions 2, and sidewalls 3, which is particularly intended for passenger cars, vans or light trucks, is schematically shown, with bead cores 2a being anchored in these bead regions accordingly. Not shown are further components for reinforcing the pneumatic vehicle tire, such as, for example, a meridian carcass and a multi-layer buffer belt. The pneumatic vehicle tire has an airtight inner layer 4, which covers and forms the inner side 4a of the tire. Figure 1 An absorber 5 is also shown, which extends in an annular manner over the inner side 4a of the pneumatic vehicle tire, is bonded to the inner side 4a by adhesively attaching to its entire surface area or a partial surface area, and is preferably composed of a thermoplastic or elastomeric foam (in particular polyurethane foam). The absorber 5 has a constant width b1 over the circumference of the tire, which constant width lies between 30% and 100% of the ground contact area of the tire. Depending on the tire size, the equally constant thickness of the absorber 5 lies between 5% and 20% of the width b1 and is thus, for example, between 20 mm and 50 mm.

[0016] As for example by Figure 2As shown, a plurality of ribs 6 extending parallel to each other are formed on the inner side 4a of the tire. These ribs 6 are formed by a heating bladder during the vulcanization of a vehicle pneumatic tire in a tire heating mold, the heating bladder being introduced into the tire to be vulcanized and filled with a heat medium (e.g., hot steam) inside. A plurality of grooves are generally formed on the outer side of the heating bladder to ensure the dissipation of air between the heating bladder and the green tire during the formation of indentations by the heating bladder. If the heating bladder filled with the heat medium abuts against the inner side of the green tire, the mentioned ribs 6 are imprinted in the inner layer 4. These ribs 6 generally extend in the manner shown in Figure 2 and, in most cases, no rib 6 is formed in the central circumferential region 4b on the inner side 4a. In most cases, this circumferential region 4b has a width b2 of 20 mm to 100 mm in the axial direction. On each side of this circumferential region 4b, the ribs 6 extend obliquely with respect to the circumferential direction on the inner side 4a between the edges of the circumferential region 4b into the corresponding bead regions 2. In the region of the inner side 4a opposite the tread 1, the ribs 6 form an acute angle of, for example, 30° to 45° with the axial direction. As shown in Figure 1 , the ribs 6 have a width b3 of, for example, 2 mm to 3 mm at their base, their mutual spacing a1 is generally 8 mm to 9 mm, and their maximum height h is especially 0.5 mm to 1 mm. The cross-sectional area of the ribs 6 is generally also rounded (e.g., in a substantially semi-circular manner), but can also be substantially rectangular.

[0017] According to the invention, at least in a partial region of the region of the inner side 4a of the inner layer 4 in contact with the sound absorber 5, thus in addition to these ribs 6, grooves 7 are also imprinted by the heating bladder. Thus, the grooves 7 are produced by corresponding elevations on the outer side of the heating bladder and are preferably located at most in the region of the inner layer intended to provide the sound absorber 5. As shown in Figure 2 , the grooves 7 on the inner side 4a of the inner layer 4 have a width b4 of especially 2 mm to 4 mm, their depth t is preferably 0.5 mm to 1 mm, and their mutual spacing a2 on the inner side 4a is especially 2 mm to 9 mm. In cross-section, they are especially designed in a groove shape and are thus rounded, for example, in a semi-circular manner, but at their deepest point they can also have groove walls converging to a point or can be bounded by groove walls extending generally in a substantially rectangular manner. In the case of the design shown in Figure 1 and Figure 2 , the grooves 7 extend parallel to each other in the circumferential direction, and in the central circumferential region 4b, the grooves 7 extend laterally from the circumferential region 4b and the intersecting ribs 6 accordingly.

[0018] In the case of a possible design variant of the present invention, the groove 7 is formed only in the central circumferential region 4b of the inner layer 4 without the rib 6. In principle, the groove 7 can also extend axially or obliquely or diagonally with respect to the circumferential direction of the tire, and their orientation can also be consistent with the orientation of the rib 6. In this case, the groove 7 can extend between the ribs 6. In the case of another design variant of the present invention, the groove 7 extends in a wave-like or zigzag form along any desired direction or along a circular or other uninterrupted path. Another possible design variant is that the groove 7 is formed only laterally from the circumferential region without the rib 6.

[0019] Figure 3 Details of the inner side 4a are shown, in which the groove 7 extends between the ribs 6 and parallel to these ribs. In Figure 4 In the case of the details shown, the grooves 7 extending parallel to each other cross the ribs 6.

[0020] As mentioned, there are many other possibilities, not shown, for forming the groove 7 in the region where the sound absorber 5 is provided. Since the groove 7 increases the adhesive bonding area with respect to the sound absorber 5 while the protruding area remains the same size, on the other hand, the thickness of the adhesive bonding layer can be reduced to achieve at least substantially the same good adhesion, thereby saving material, weight, and also cost. The present invention can also adhesively attach the sound absorber 5 partially, and especially in those regions where the groove 7 is specifically formed. This measure can also save weight, material, and cost.

[0021] Explanation of reference numerals

[0022] 1 Tread

[0023] 2 Bead region

[0024] 2a Bead core

[0025] 3 Sidewall

[0026] 4 Inner layer

[0027] 4a Inner side

[0028] 4b Circumferential region

[0029] 5 Sound absorber

[0030] 6 Rib

[0031] 7 Groove

[0032] a1, a2 Spacing

[0033] b1, b2, b3, b4 Width

[0034] h Height

[0035] t depth

Claims

1. A pneumatic vehicle tire having a meridian structure, the pneumatic vehicle tire having a formed tread (1), sidewalls (3), bead regions (2) and an airtight inner liner (4), and a sound absorber (5), the airtight inner liner forming an inner side (4a) facing the internal space of the pneumatic vehicle tire, ribs (6) protruding from the horizontal plane of the inner side (4a) are formed on the inner side (4a) of the inner liner (4), and these ribs have been imprinted in the inner liner by a heated bladder which is introduced into the interior of the tire during the vulcanization of the pneumatic vehicle tire in a tire heating mold, the sound absorber is arranged to extend in an annular manner on the circumferential region (4b) of the inner side (4a) opposite to the tread (1). It is characterized in that grooves (7) have been formed by corresponding protrusions on the outer side of the heated bladder at least in a partial region of the circumferential region (4b) of the inner side (4a) of the inner liner (4), the sound absorber (5) is arranged on this circumferential region, these grooves (7) extend from the horizontal plane of the inner side (4a) into the inner liner and have a mutual spacing, and the adhesive bonding of the sound absorber is carried out exactly in the region of the grooves, and these grooves (7) have a mutual spacing (a2) of 2 mm to 9 mm on the inner side (4a) of the inner liner (4).

2. The pneumatic vehicle tire according to claim 1, wherein, These grooves (7) are formed in the central circumferential region (4b) of the inner side (4a) of the inner liner (4) without ribs (6).

3. The pneumatic vehicle tire according to claim 1 or 2, characterized in that, These grooves (7) are formed laterally from the central circumferential region (4b) of the inner side (4a) of the inner liner (4) without ribs (6).

4. The pneumatic vehicle tire according to claim 1, wherein, These grooves (7) are formed to extend at least substantially parallel to these ribs (6).

5. The pneumatic vehicle tire according to claim 4, characterized in that, These grooves (7) or parts of the grooves (7) are formed to extend between the ribs (6).

6. The pneumatic vehicle tire according to claim 1, characterized in that, The grooves (7) or parts of the grooves (7) cross the ribs (6).

7. The pneumatic vehicle tire according to claim 1, characterized in that, Grooves (7) extending along the circumferential direction of the tire are provided.

8. The pneumatic vehicle tire according to claim 1, wherein, Grooves (7) extending along the axial direction are provided.

9. The pneumatic vehicle tire according to claim 1, characterized in that, Grooves (7) extending along an uninterrupted path in a circular form or in some other way are provided.

10. The pneumatic vehicle tire according to claim 1, characterized in that, Grooves (7) extending in a waveform are provided.

11. The pneumatic vehicle tire according to claim 1, characterized in that, Grooves (7) extending in a zigzag form are provided.

12. The pneumatic vehicle tire according to claim 1, wherein, These grooves (7) have a width (b4) of 2 mm to 4 mm on the inner side (4a) of the inner liner (4).

13. The pneumatic vehicle tire according to claim 1, characterized in that, These grooves (7) have a depth (t) relative to the horizontal plane of the inner side (4a) of the inner liner (4) of 0.5 mm to 1 mm.

14. The pneumatic vehicle tire according to claim 1, characterized in that, These grooves (7) have a circular cross-section.

15. The vehicle pneumatic tire according to claim 14, characterized in that, These grooves (7) have a semi-circular cross-section.

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