DE102020205836A1 - Pneumatic vehicle tires - Google Patents

Abstract

The invention relates to a pneumatic vehicle tire with a tread with at least one profile rib (1) bounded on each side by a circumferential groove (2), which over its circumference opens into both circumferential grooves (2) with a plurality of circumferential grooves (2) inclined in the same direction in plan view , a width (b1) of 0.4 mm to 1.6 mm and a maximum depth (t1) of 60% to 100% of the profile depth (T1) having incisions (3) is provided with opposing incision walls (5), wherein the incisions (3) each have an edge-side incision section (3b) which runs in an arc to one of the circumferential grooves (2) and which is only widened on the inside of the arc and on the tread periphery with a bevel (6). The incisions (3) run, viewed from above , elongated S-shaped and have edge-side incision sections (3b) running in an arc to the circumferential grooves (2), which on the inside of the arc and on the walkway eifenperipherie are each widened with a bevel (6), the edge-side incision sections (3b) are connected to one another by a straight and to the axial direction at an angle (α) of 20 ° to 75 ° running central incision section (3a), along which the Chamfers (6) run out continuously in opposite directions.

Description

The invention relates to a pneumatic vehicle tire with a tread with at least one tread rib bounded on each side by a circumferential groove, which over its circumference with a plurality of in plan view with respect to the circumferential direction inclined in the same direction, into both circumferential grooves, a width of 0.4 mm to 1.6 mm and a maximum depth of 60% to 100% of the profile depth having incisions is provided with opposing incision walls, the incisions each having an arcuate incision section extending to one of the circumferential grooves, which is exclusively on the inside of the curve and on the tread periphery with a Bevel is widened.

Such a tire is for example from DE 10 2015 202 613 A1 known. According to one exemplary embodiment, the tread of the tire has a profile rib which is delimited on both sides by circumferential grooves and which is provided with a transition curve on one circumferential groove. A plurality of incisions running parallel to one another in plan view are formed in the profile rib. The incisions each have an edge-side incision section which extends in an arc shape to that circumferential groove on which the profile rib has the transition rounding. A bevel extending to the circumferential groove is formed on the inside of the arch. According to a variant, the incision has two legs running in opposite directions to one another, between which a rounded transition section is formed, the bevel running out along the rounded transition section. Such cuts are beneficial in terms of noise emissions (rolling noise) and the wet braking properties of the tire.

The bevels provided for incisions counteract a “rolling in” of the incision edge areas when braking, which improves the braking properties - both on dry and wet roads. With regard to the braking properties on wet roads, the additional superficial empty volume (“surface void”) created by the bevel is also an advantage. This additional empty volume, however, unfavorably increases the rolling noise of the tire.

The invention is therefore based on the object of further optimizing a pneumatic vehicle tire of the type mentioned at the outset with regard to the conflicting objectives that exist between the rolling noise and the braking properties.

The object is achieved according to the invention in that the incisions, viewed in plan view, extend in an elongated S-shape and have edge-side incision sections that run arcuately to the circumferential grooves, which are widened on the inside of the arc and on the tread periphery with a bevel, the edge-side incision sections by a straight and to the axial direction at an angle of 20 ° to 75 ° extending central incision section are connected to each other, along which the chamfers run continuously in opposite directions.

The incisions therefore have a central incision section which is more inclined to the axial direction and - corresponding to the S-shape - edge-side incision sections extending essentially in the axial direction. In the central incision section, the braking forces occurring in the braking process in or essentially in the circumferential direction act on the incision areas or incision edges due to the inclination of the central incision section in such a way that lower forces act during braking than in the edge-side incision sections. The bevels that are more pronounced in the edge-side incision sections effectively counteract the curling of the incision edge areas, which is favorable with regard to the braking properties. The bevels run out in the less critical, central incision section, so that the surface void and the associated rolling noise are kept to a minimum.

According to a preferred embodiment, the chamfers run out in the central incision section, based on the circumferential direction, with mutual overlap. The middle incision section is therefore provided with bevels on both sides over the majority of its extent. It is particularly favorable if the chamfers each run over the entire central incision section. In these designs, the chamfers shorten as the profile rib is worn away, so that the surface void and thus the rolling noise are reduced. At the same time, the rigidity of the profile rib increases, which means that it deforms less under the braking loads that occur - compared to when it is new - and thus the tendency for the cut edge areas to curl is reduced. The bevels shortened by the abrasion continue to effectively counteract the curling of the now somewhat stiffer cut edge areas. The measures explained are therefore particularly favorable with regard to the conflicting goals mentioned.

The central incision section preferably has a length, projected in the axial direction, of 45% to 65%, in particular from 50% to 60%, of the width of the profile rib. The central incision section is therefore corresponding pronounced, which contributes to an advantageous solution to the conflicting goals mentioned.

According to a further preferred variant, the edge-side incision sections run - based on straight lines which connect the ends of the incision center line in the respective edge-side incision section - at an angle of 15 ° to 30 ° to the axial direction.

Furthermore, it is favorable if the angle at which the edge-side incision sections run relative to the axial direction is 20 ° to 40 ° smaller than the angle at which the associated central incision section runs relative to the axial direction.

According to a further preferred variant, the edge-side incision sections open into the circumferential grooves in the axial direction or at an angle of +/- 3 ° to this.

In particular, the edge-side incision sections have end sections which run in the axial direction and open into the circumferential groove. As a result of these measures, the profile rib is free of pronounced obtuse and acute-angled profile rib areas at the incision ends, whereby a uniform abrasion of the profile rib is maintained. As a result, a high net contact area of the tread is maintained over the life of the tire, which is favorable in terms of power transmission to the road surface and is therefore advantageous for the braking properties.

It is also preferred if the chamfers, viewed in the cross section of the incision, run at an angle of 30 ° to 60 °, in particular 40 ° to 50 °, to the radial direction.

The angle at which the central incision section extends to the axial direction is preferably 40 ° to 70 °.

Another preferred embodiment is characterized in that the bevels extend in the radial direction to a depth and, viewed in cross section, have a width, the depth and width continuously decreasing from the bevel end located on the respective circumferential groove to the bevel end located in the central incision section.

The depth to which the chamfers extend, determined at the deepest points of the chamfers, is preferably 1.0 mm to 3.0 mm, in particular at least 2.0 mm.

For further optimization of the tire with regard to the mentioned conflict of objectives between the rolling noise and the braking properties, it is also advantageous if the mentioned incisions are the only incisions in the profile rib.

• 1 eine vergrößerte Draufsicht auf einen Umfangsabschnitt einer Profilrippe eines Laufstreifens eines Fahrzeugluftreifens mit einer Ausführungsvariante der Erfindung und
• 2 einen vergrößerten Schnitt entlang der Linie II-II der 1.

Further features, advantages and details of the invention will now be described in more detail with reference to the drawing, which schematically shows an embodiment of the invention. Show it

• 1 an enlarged plan view of a peripheral portion of a tread rib of a tread of a pneumatic vehicle tire with an embodiment of the invention and
• 2 an enlarged section along the line II-II of FIG 1 .

Pneumatic vehicle tires designed according to the invention are, in particular, tires of the radial type for passenger cars, vans or light trucks.

1 shows a circumferential section of a circumferential profile rib 1 a tread of a pneumatic vehicle tire, which is laterally of a circumferential groove that runs straight in plan view 2 is limited. The circumferential grooves 2 are in the radial direction to the respective intended profile depth T ₁ (in 2 indicated), which for the preferred type of tire is usually 6.0 mm to 10.0 mm.

The profile rib 1 has a width at the tread periphery in the axial direction B. on and is with a variety of over the circumference of the profile rib 1 Essentially evenly distributed, elongated S-shaped incisions in plan view 3 provided which the profile rib 1 traverse and therefore in the two circumferential grooves 2 merge. Under elongated S-shaped incisions 3 are also to be understood as being elongated and mirrored in an S-shape when viewed from above.

The in 1 uppermost incision 3 is the incision center line following the incision course m _E indicated by dashed lines. The cuts 3 are viewed in plan view and based on straight lines of extension 1 showing the ends of the respective incision 3 belonging incision center line m _E connect, formed inclined in the same direction to the circumferential direction. Immediately consecutive cuts 3 have mutual minimum distances of in particular 25.0 mm to 50.0 mm from one another in the circumferential direction.

The cuts 3 When viewed from above, each consist of a straight, central incision section 3a and two arcuate to the respective circumferential groove 2 running, edge-side incision sections 3b together. The middle incision section 3a points - based on the incision center line m _E - a length projected in the axial direction l _a from 45% to 65%, in particular from 50% to 60% of the width B. the profile rib 1 and extends at a constant angle to the axial direction α from 20 ° to 75 °, in particular from 40 ° to 70 °, the angle α of the middle incision sections 3a in the shown peripheral section of the profile rib 1 of incision 3 to incision 3 increases by up to 7 ° in particular. The edge-side incision sections 3b close, viewed in plan view, kink-free at the ends of the central incision section 3a and run in relation to the ends of the incision center line m _E in the respective edge-side incision section 3a connecting straight lines 1 'to the axial direction at an angle β from 15 ° to 30 °, where the angle β is preferably 20 ° to 40 ° smaller than the angle α of the associated central incision section 3a . In the exemplary embodiment shown, the edge-side incision sections have 3a into the circumferential grooves 2 opening end sections extending in the axial direction 3b ' on. Alternatively, the edge-side incision sections 3b relative to the axial direction also at an angle of +/- 3 ° in the circumferential grooves 2 open out, the angle in each case opposite one at the confluence of the incisions 3 at the periphery of the tread to the cutting center line m _E applied tangent is determined.

As 2 shows, each incision has 3 a bottom of the cut 4th and two opposing incision walls 5 on, being at each incision wall 5 a bevel on the periphery of the tread 6th is trained ( 1 ). Every cut 3 also has between the incision walls 5 - except for those areas in which the bevels are superficial 6th are formed - a constant width b ₁ from 0.4 mm to 1.6 mm, in particular from up to 1.2 mm, preferably from up to 0.8 mm, and a maximum depth in the radial direction t ₁ from 60% to 100%, in particular from 75% to 95%, of the profile depth T ₁ on. The edge-side incision sections 3b can be made shallower than the central incision section 3a .

According to 1 run along the different incision walls 5 trained bevels 6th over the middle incision section 3a and on the inside of the arc over the respective edge-side incision section 3b , with the bevels 6th up to the corresponding circumferential groove 2 are sufficient. In the middle section of the incision 3a the bevels run 6th - based on the circumferential direction - with mutual overlap in opposite directions of incision.

Every bevel 6th runs perpendicular to the incision center line m _E aligned cross-section of the incision 3 viewed at an angle to the radial direction γ ( 2 ) from 30 ° to 60 °, in particular from 40 ° to 50 °, which over the extension of the chamfers 6th is constant or varies by a maximum of 2 °. Every bevel 6th is made up of one in the middle incision section 3a running bevel surface 6a and one in the edge-side incision section 3b running bevel surface 6b together, the bevel surface 6b a curved surface and the chamfer surface 6a at a constant angle γ neglecting the tire curvature is a flat surface.

As 2 shows, the bevels are enough 6th in the radial direction to a depth t _F and point, im perpendicular to the incision center line m _E aligned cross-section of the incision 3 considered a breadth b _F on. The depth t _F and the width b _F take from the respective circumferential groove 2 bevel end lying in the middle incision section 3a bevel end continuously. At the deepest point of the bevels 6th is the depth t _F 1.0 mm to 3.0 mm, in particular at least 2.0 mm.

In the embodiment shown, there is between each bevel 6th and the respective incision wall 5 a transition rounding 7th provided, which is designed in such a way that the measured angle to the radial direction of the transition rounding 7th applied tangent (not shown) from the radially inner end of the chamfer 6th to the incision wall 5 enlarged.

The invention is not restricted to the exemplary embodiment described.

The bevels preferably each run at least over the majority of the length of the central incision section, which is related to the incision center line and is projected in the axial direction. The incisions can also run parallel to one another in plan view. Furthermore, the circumferential grooves can also run zig-zag or wave-shaped in plan view, for example.

List of reference symbols

1

Profile rib

2

Circumferential groove

3

incision

3a

middle incision section

3b

edge-side incision section

3b '

End section

4th

Bottom of the cut

5

Incision wall

6th

chamfer

6a, 6b

Bevel surface

7th

Transitional rounding

B, b1, bF

broad

la

length

l

Extension line

l '

line

in my opinion

Incision centerline

t1

maximum depth

tF

depth

T1

Tread depth

α, β, γ

angle

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 102015202613 A1 [0002]

Claims (13)

Pneumatic vehicle tire with a tread with at least one tread rib (1) bounded on each side by a circumferential groove (2), which over its circumference with a plurality of inclined in plan view with respect to the circumferential direction in the same direction, into both circumferential grooves (2), a width ( b ₁ ) from 0.4 mm to 1.6 mm and a maximum depth (t ₁ ) of 60% to 100% of the profile depth (T ₁ ) having incisions (3) is provided with opposing incision walls (5), the Incisions (3) each have an edge-side incision section (3b) which extends arcuately to one of the circumferential grooves (2) and which is widened exclusively on the inside of the arc and at the tread periphery with a bevel (6), characterized in that the incisions (3), in Viewed from above, they run in an elongated S-shape and have edge-side incision sections (3b) which run in an arc to the circumferential grooves (2) and which are on the inside of the arc and on the Tread periphery are each widened with a bevel (6), wherein the edge-side incision sections (3b) are connected to one another by a straight and to the axial direction at an angle (α) of 20 ° to 75 ° running central incision section (3a), along which the Chamfers (6) run out continuously in opposite directions. Pneumatic vehicle tires after Claim 1 , characterized in that the bevels (6) in the central incision section (3a), based on the circumferential direction, terminate with mutual overlap. Pneumatic vehicle tires after Claim 2 , characterized in that the bevels (6) each run over the entire central incision section (3a). Pneumatic vehicle tires according to one of the Claims 1 until 3 , characterized in that the central incision section (3a) has a length (l _a ) projected in the axial direction of 45% to 65%, in particular from 50% to 60%, of the width (B) of the profile rib (1). Pneumatic vehicle tires according to one of the Claims 1 until 4th , characterized in that the edge-side incision sections (3b) - based on straight lines (l ') which connect the ends of the incision center line (m _E ) in the respective edge-side incision section (3b) - to the axial direction at an angle (β) of 15 ° to 30 °. Pneumatic vehicle tires after Claim 5 , characterized in that the angle (β) at which the edge-side incision sections (3b) run to the axial direction is 20 ° to 40 ° smaller than the angle (α) at which the associated central incision section (3a) to the axial direction Direction runs. Pneumatic vehicle tires according to one of the Claims 1 until 6th , characterized in that the edge-side incision sections (3b) open into the circumferential grooves (2) in the axial direction or at an angle of +/- 3 ° to this. Pneumatic vehicle tires after Claim 7 , characterized in that the edge-side incision sections (3b) have end sections (3b ') which run in the axial direction and open into the circumferential groove (2). Pneumatic vehicle tires according to one of the Claims 1 until 8th , characterized in that the bevels (6), viewed in the cross section of the incision (3), extend to the radial direction at an angle (γ) of 30 ° to 60 °, in particular 40 ° to 50 °. Pneumatic vehicle tires according to one of the Claims 1 until 9 , characterized in that the angle (α) at which the central incision section (3a) extends to the axial direction is 40 ° to 70 °. Pneumatic vehicle tires according to one of the Claims 1 until 10 , characterized in that the chamfers (6) extend in the radial direction to a depth (t _F ) and, viewed in cross section, have a width (b _F ), the depth (t _F ) and the width (b _F ) starting from of the respective circumferential groove (2) continuously decrease to the bevel end located in the central incision section (3a). Pneumatic vehicle tires after Claim 11 , characterized in that the depth (t _F ) to which the chamfers (6) extend, determined at the deepest points of the chamfers (6), 1.0 mm to 3.0 mm, in particular at least 2.0 mm, amounts to. Pneumatic vehicle tires according to one of the Claims 1 until 12th , characterized in that said incisions (3) are the only incisions (3) in the profile rib (1).

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