CA3000026C

CA3000026C - Pneumatic vehicle tyres

Info

Publication number: CA3000026C
Application number: CA3000026A
Authority: CA
Inventors: Klaus Wiese; Torsten Heinhaupt; Marieken Vellinga-Wallenhauer; Jan Schlittenhard
Original assignee: Continental Reifen Deutschland GmbH
Current assignee: Continental Reifen Deutschland GmbH
Priority date: 2015-10-29
Filing date: 2016-07-11
Publication date: 2021-10-19
Anticipated expiration: 2036-07-11
Also published as: DE102015221118A1; CA3000026A1; RU2687536C1; EP3368345B1; EP3368345A1; WO2017071842A1

Abstract

The invention relates to a pneumatic vehicle tyre having a directional tread with profile positives, for example, profile block rows (1, 2) or profile bands (3), which are separated from one another by grooves, such as, for example, circumferential grooves (3), transverse grooves (4), oblique grooves (7), and the like, wherein profile positives having spikes (9) positioned in spike holes (8) are provided and, around each spike (9), starting from the spike (9) in the profile positive, at least in the two circumferential directions (U) - in and counter to the direction of movement during forward travel - shallow and elongate recesses (10, 10', 11, 11', 12, 12') having different volumes and different lengths of extent are formed as reservoirs for receiving the ice shards produced when the spike (9) scrapes on ice. The recess(es) (10, 10') which, during forward travel, extends or extend from the spike (9) in the direction of movement, has or have the greatest volume (V1) in the event of a plurality of recesses (10, 10').

Description

2 Pneumatic vehicle tyres Description The invention relates to a pneumatic vehicle tire having a tread of directional design and with profile positives, for example profile block rows or profile strips, which are separated from one another by channels, for example circumferential channels, transverse channels, oblique channels and the like, wherein profile positives are provided with spikes positioned in spike holes, and, around each spike, shallow and elongate depressions with different volumes and different extent lengths, as reservoirs for receiving the ice chips that form when the spike scrapes on ice, are formed in the profile positive so as to extend at least in both circumferential directions - in and counter to the rolling direction during forward travel - proceeding from the spike. The depression(s) that extend(s) from the spike in the rolling direction during forward travel has or have, in sum total in the case of multiple depressions, the greatest volume, wherein at least one further depression extends from the spike outward in the direction of the tire shoulder situated closest to the spike, which at least one further depression, in sum total in the case of multiple depressions, has the smallest volume.
It is known and conventional for trends of pneumatic vehicle tires to be equipped with spikes in order, under winter driving conditions, to increase the power transmission from the tire to snow-covered and/or ice-covered roadways. The general action of spiked tires is in this case based on several effects. Firstly, spikes penetrate into, and mechanically mesh with, ice situated on the roadway. During braking and traction processes, relative movements (slippage) furthermore occur between the pneumatic vehicle tire and the ice-covered roadway, during which the spikes are pulled through the ice and in the process cut channels into the ice surface. The ice chips ("ice powder") formed in the process commonly collect(s) around the respective spike, whereby both the ice grip action of the spike and the ice grip action of the rubber material of the tread surrounding the spike deteriorate.
To counteract the adverse effects of the ice chips that form, it is known for shallow depressions to be provided, in the immediate vicinity of the spike, as discharge channels or reservoirs for receiving the chips. Such discharge channels or depressions are known in a variety of embodiments.
Date Recue/Date Received 2021-02-02 A tire of the type mentioned in the introduction is known for example from WO
2009/147047 Al. The tread of said pneumatic vehicle tire has profile blocks which are equipped with spikes, wherein at least one local, channel-like depression is formed in the region of each spike. The depressions end in each case within the profile block, wherein each depression has a spacing of at most 1.0 cm to the spike hole. The sum of the volumes, in mm3, of the depressions provided around a spike is greater than or equal to the product of the minimum cross-sectional area, in mm2, of that part of the spike pin which projects beyond the tread surface and the length of a depression. The volumes amount to for example in each case 70 mm3. The depressions may be of straight or else curved design, wherein the cross-sectional area of each depression may vary over the profile of the depression, and the cross-sectional area is preferably in each case at its smallest at the spike.
A pneumatic vehicle tire very similar to WO 2009/147047 Al is known from WO
2009/147046. The profile blocks of the tread have spike holes around which in each case channel-like depressions are provided, wherein each channel-like depression opens into a channel that delimits the respective profile block. The sum of the average cross-sectional areas of the provided depressions is greater than or equal to the minimum cross-sectional area of that part of the spike pin which projects beyond the tread surface.
A further pneumatic vehicle tire with a spiked tread is known from WO
2014/123181 Al.
Around each spike hole provided in the tread, there are formed in each case two arcuately running depressions, which are each delimited by two radii relating to the spike axis.
Furthermore, around each spike hole, there is provided a third depression with an arcuate section, the ends of which are each adjoined by a short straight section which opens in each case into a transverse channel that delimits the profile block.
DE 10 2009 044 547 Al has disclosed a further pneumatic vehicle tire with a spiked tread.
The profile blocks of the tread have a depression which surrounds the spike in ring-shaped fashion and from which further channel-like depressions run to the transverse channels that delimit the profile block. The channel-like depressions each have a width of 1.0 mm to 5.0

3 mm, and each have a depth of 0.5 mm to 1.5 mm. In each case one rib belonging to the profile block is formed between the channel-like depressions. A further pneumatic vehicle tire whose tread has spikes with ring-shaped encircling depressions is known from WO
2013/092434 Al.
If the depressions provided cannot receive the full amount of ice chips that form, the ice chips collect between the tread and the roadway, whereby the meshing of the spikes with the ice does not function optimally, and the ice grip accordingly deteriorates. On the other hand, an unduly large volume of the depressions provided has an adverse effect on the ice grip characteristics of the profile positives of the tread, because depressions of excessively large area significantly reduce the rubber surface of the profile positives.
Since, depending on the type of relative movement between the vehicle tire and ice-covered roadway as mentioned in the introduction, the spikes, depending on load and load direction, cut channels of different length into the ice surface, resulting in different amounts of ice chips, the discharge channels or depressions provided in the region of spikes of the known pneumatic vehicle tires have potential for improvement.
The invention is therefore based on the object, in the case of a tire of the type mentioned in the introduction with a directional tread, of adapting the depressions provided around the spikes and serving as ice reservoirs to the different loads during traction, during braking and during the action of lateral forces.
The stated object is achieved according to the invention in that the depression(s) that extend(s) from the spike in the rolling direction during forward travel has or have, in sum total in the case of multiple depressions, the greatest volume.
The average sliding distances are at their greatest in traction situations, such that the channels formed in the ice surface are at their longest during the transmission of traction power. That depression or those depressions for receiving ice chips which enter(s) the ground contact patch first during the rolling of the pneumatic vehicle tire during forward travel is or are therefore designed, according to the invention, with the greatest volume. The

4 depression(s) that extend(s) from the spike in the rolling direction during forward travel preferably also has or have the greatest extent length(s).
The spikes exhibit, on average, short sliding distances over the ice surface during relative movements that occur as a result of transverse slippage during the transmission of lateral forces. According to the invention, at least one depression extends from the spike outward in the direction of the tire shoulder situated closest to the spike, which at least one depression, in sum total in the case of multiple depressions, has the smallest volume of all depressions. Said depression preferably also has the smallest extent length.
The sliding distances of the spike under ABS braking force transmission conditions are on average shorter than those under traction conditions. Therefore, the depression(s) that extend(s) from the spike counter to the rolling direction during forward travel has or have, in sum total in the case of multiple depressions, a volume which is smaller than the volume of the depression(s) that extend(s) from the spike in the rolling direction during forward travel but which is greater than the volume of the depression(s) that extend(s) from the spike outward in the direction of the tire shoulder situated closest to the spike. Said depression(s) has or have in particular an extent length which is smaller than the extent length of the depression(s) that extend(s) from the spike counter to the rolling direction during forward travel but which is greater than the extent length of the depression(s) that extend(s) outward in the direction of the tire shoulder situated closest to the spike.
In the case of the depressions being of the same design in all directions, too large a volume would be available, and the friction power of the rubber surface would be reduced to too great an extent. In the case of depressions designed according to the invention, the volumes are optimally adapted to the amounts of ice chips that form as a result of the different relative movements between spike and ice-covered roadway.
In a particularly preferred embodiment of the invention, the depression(s) that extend(s) from the spike in the rolling direction during forward travel has or have a volume from 12.0 me to 13.3 mm3. The depression(s) that extend(s) outward in the direction of the tire shoulder situated closest to the spike preferably has or have a volume of 9.5 mm3 to 10.7 mm3. Furthermore, the volume of the depression(s) that extend(s) from the spike counter to the rolling direction during forward travel is preferably 10.7 mm3 to 12.0 mm3.
Embodiments are particularly advantageous and preferred in which the depression(s) that

5 extend(s) from the spike in the rolling direction during forward travel has or have an extent length of 4.9 mm to 5.2 mm, wherein furthermore, the depression(s) that extend(s) outward in the direction of the tire shoulder situated closest to the spike has or have an extent length of 3.7 mm to 4.2 mm. The extent length of the depression(s) that extend(s) from the spike counter to the rolling direction during forward travel is 4.2 mm to 4.7 mm.
Further advantageous embodiments of the depression(s) contribute to the achievement of the abovementioned effects according to the invention. In this context, it is expedient if the depressions have, at least over a major part of their extent, a depth of 0.5 mm to 1.0 mm. A
further measure consists in the depressions that extend in and counter to the rolling direction being arranged in pairwise fashion and mirror-symmetrically about the same axis of symmetry, wherein the axis of symmetry runs at an angle of -20 to 20 with respect to the circumferential direction.
In a further advantageous embodiment of the invention, a pair of depressions extends from the spike outward in the direction of the tire shoulder situated closest to the spike, wherein the depressions are likewise arranged mirror-symmetrically about an axis of symmetry. The abovementioned axes of symmetry run perpendicular or substantially perpendicular to one another.
Further features, advantages and details of the invention will now be described in greater detail with reference to the drawing, which schematically illustrates one exemplary embodiment of the invention. In the figures:
figure 1 shows a plan view of a section of a developed view of a tread of a pneumatic vehicle tire with a design variant of the invention, figure 2 shows an enlarged plan view of a partial region of a profile block, and

6 figure 3 shows a section along the line in figure 2.
Pneumatic vehicle tires according to the invention are winter tires for passenger motor vehicles, vans or light trucks, with directional treads.
The tread shown in figure 1 has two shoulder-side block rows 1, in each case one middle block row 2 adjoining these, and in the central tread region, a profile band 3 which runs in encircling fashion in a circumferential direction and which is separated from the middle block rows 2 by in each case one circumferential channel 4, which runs in a straight manner in the exemplary embodiment shown.
Transverse channels 5 which run in an altogether arrow-shaped manner from the tread edges to the circumferential channels 4 provide the tread with the abovementioned directional nature. The transverse channels 5, which run in a slightly curved manner in plan view in the exemplary embodiment shown, preferably extend at an angle of 30 to 60 with respect to the circumferential direction in the region in which they open into the circumferential channels 4, and run substantially in an axial direction in the region of their shoulder-side end. The profile blocks 6a of the shoulder-side block rows 1 are separated from the profile blocks 6b of the respectively adjoining middle block row 2 by oblique channels 7, which run between transverse channels 5 situated adjacently in the circumferential direction.
A tire with this tread is mounted on the vehicle such that, during forward travel, those ends of the transverse channels 5 which are situated at the inside of the tread enter the ground contact patch first. It is basically possible for pneumatic vehicle tires according to the invention to have treads which are designed to be directional in some other way.
The profile strip 3 and the profile blocks of the block rows 1 and 2 are each equipped with sipes, which are in particular designed in a manner known per se.

7 In the profile blocks 6a, 6b of the block rows 1 and 2 there is furthermore formed in each case one spike hole 8, into which a spike 9, which is composed of a spike body and a spike pin in a manner known per se, is inserted and anchored. Each spike hole 8 has a diameter adapted to the respective spike body.
Figure 2 shows a plan view of a region of a profile block 6a from the right-hand shoulder block row 1 in figure 1. The circumferential direction of the tread is denoted by the double arrow "U", and that side of the illustrated region which faces toward the closest tire shoulder is denoted by "A". The spike axis which runs through the center of the spike 9, and which is denoted by ai, runs in a radial direction. That part of the profile block 6a which, in the mounted state of the tire, comes into contact with the underlying surface first during forward travel is denoted by "V".
Around each spike 9 or each spike hole 8 there are provided superficially formed, elongate depressions 10, 10', 11, 11', 12, 12' which are arranged in pairwise fashion and which serve as reservoirs for receiving the ice chips that splinter off as the tire rolls on an ice-covered underlying surface.
The depressions 10, 10' belonging to a pair, the depressions 11, 11' and the depressions 12, 12' are in each case of corresponding design. The depressions 10, 10' extend from the spike 9 in the circumferential direction, specifically in the rolling direction during forward travel, and have the greatest length 11 and, in sum total, the greatest volume Vi. The depressions 10, 10' are situated substantially diametrically opposite the depressions 11, 11' in a manner separated by the spike hole 8, therefore extend from the spike 9 counter to the rolling direction, have the second-greatest length 12 and, in sum total, the second-greatest volume V2. The third pair of depressions 12, 12' extends from the spike 9 in the direction of the tire shoulder A, wherein these depressions 12, 12' have the smallest length 13 and, in sum total, the smallest volume V3 of all pairs of depressions. The length h of the depressions 10, 10' is 4.9 mm to 5.2 mm, the length 12 of the depressions 11, 11' is 4.2 mm to 4.7 mm and the length 13 of the depressions 12, 12' is 3.7 mm to 4.2 mm, where h >12 > 13.
The total volume Vi of the depressions 10, 10' is 12 mm3 to 13.3 mm3, the total volume V2 of the depressions Date Recue/Date Received 2021-02-02

8 11, 11' is 10.7 mm3 to 12 mm3 and the total volume V3 of the depressions 12, 12 is 9.5 mm3 to 10.7 mm3, where VI > V2> V3.
The volumes VI, V2, V3 of the depressions 10, 10', 11, 11', 12, 12' are optimally adapted to the amounts of ice chips that form as a result of the different relative movements between spike 9 and ice-covered roadway, the depressions 10, 10' are optimally adapted to those that form during the transmission of traction power, the depressions 11, 11' are optimally adapted to those that form during ABS braking, and the depressions 12, 12' are optimally adapted to those that form during the transmission of lateral forces.
All of the depressions 10, 10', 11, 11', 12, 12' furthermore have, at least over the major part of their extent, a depth T1 (figure 3) of 0.5 mm to 1.0 mm. The depth T1 may increase or decrease, in particular in continuous fashion, over the length extent of the depressions 10, 10', 11, 11', 12, 12'.
In the design variant shown, all of the depressions 10, 10', 11, 11', 12, 12' adjoin the mold pin insert used during the vulcanization, wherein a very thin rubber skin is normally formed between said mold pin insert and the depressions. The depressions 10, 10', 11, 11' and 12, 12' that belong to a pair are designed and arranged mirror-symmetrically with respect to one another with regard to axes of symmetry az and a3 running through the spike central point in plan view.
In accordance with their diametric arrangement, the two depressions 10, 10' and 11, 11' arranged in pairwise fashion are mirror-symmetrical with respect to the same axis of symmetry az. The axis of symmetry a-, runs preferably at an angle a of -20 to 20 with respect to the circumferential direction U, wherein, in the embodiment shown, the depressions 10, 10' are inclined in the direction of the tyre shoulder A. The depressions 12, 12' arranged in pairwise fashion run mirror-symmetrically with respect to one another about the axis of symmetry a3 which, in the preferred design variant shown, runs perpendicular to the axis of symmetry az, wherein a3 may deviate from said perpendicular configuration by an angle of -20 to 20 .

9 The depressions 10, 10', 11, 11', 12, 12' arranged in each case in pairwise fashion have in each case a mutual spacing b1 of 0.4 mm to 0.6 mm, in particular of 0.5 mm, at their inner end regions adjacent to the spike 9, wherein, in the design variant shown, the mutual spacing increases in continuous fashion toward the outer end regions of the depressions 10,

10', 11, 11', 12, 12' in each case by up to 1.0 mm, in particular by up to 0.5 mm. The depressions 10, 10', 11, 11', 12, 12' themselves have in each case a width b2 of 1.0 mm to 1.5 mm, in particular 1.25 mm, at their inner end regions situated at the spike 9, wherein the greatest width b3 of said depressions at their outer end regions is 1.5 mm to 2.5 mm.
In each tread half, the depressions 10, 10', 11, 11', 12, 12' arc arranged such that, in relation to the position of the respective spike 9, the depression(s) 10, 10' with the greatest volume VI extend(s) in the rolling direction during forward travel, the depression(s)

11, 11' with the second-greatest volume V2 is or are situated substantially diametrically opposite the former depression(s), and the depression(s) 12, 12' with the smallest volume V3 extend(s) in the direction of the closest tread edge.
In a further design variant which is not illustrated, instead of pairs, in each case only one depression is provided, wherein said depressions have volumes VI, V2, V3 analogously to the embodiment above. The external shape of the depressions may deviate from that illustrated.

5 List of reference numerals 1 ................... Block row 2 ................... Block row 3 ................... Profile strip 4 ................... Circumferential channel .............. 5 Transverse channel 6a, 6b .............. Profile block 7 ................... Oblique channel 8 ................... Spike hole 9 ................... Spike .............. 10, 10, 11, 11', 12, 12 Depression al ................. Spike axis az, a3 .............. Axis of symmetry bl ................. Spacing b2 .................. Width .............. 11, 12,h Length Ti .................. Depth .................... Radial direction .................... Circumferential direction VI, V2, V3 ......... Volume a ................ Angle

Claims

Patent claims

1. A pneumatic vehicle tire having a tread of directional design and with profile positives, for example profile block rows or profile strips, which are separated from one another by channels, for example circumferential channels, transverse channels, oblique channels and the like, wherein profile positives are provided with spikes positioned in spike holes, and, around each spike, shallow and elongate depressions with different volumes and different extent lengths, as reservoirs for receiving the ice chips that form when the spike scrapes on ice, are formed in the profile positive so as to extend at least in both circumferential directions (U) - in and counter to the rolling direction during forward travel - proceeding from the spike, wherein in that the depression(s) that extend(s) from the spike in the rolling direction during forward travel has or have, in sum total in the case of multiple depressions, the greatest volume (Vi), wherein at least one further depression extends from the spike outward in the direction of the tire shoulder situated closest to the spike, which at least one further depression, in sum total in the case of multiple depressions, has the smallest volume (V3).

2. The pneumatic vehicle tire as claimed in claim 1, wherein the depression(s) that extend(s) from the spike in the rolling direction during forward travel has or have the greatest extent length(s) (11).

3. The pneumatic vehicle tire as claimed in claim 1, wherein the depression(s) that extend(s) from the spike outward in the direction of the tire shoulder closest to the spike has or have the smallest extent length(s) (13).

4. The pneumatic vehicle tire as claimed in any one of claims 1 to 3, wherein the depression(s) that extend from the spike counter to the rolling direction during forward travel has or have, in sum total in the case of multiple depressions, a Date Recue/Date Received 2021-02-02 volume (V2) which is smaller than the volume (Vi) of the depression(s) that extend(s) from the spike in the rolling direction during forward travel but which is greater than the volume (V3) of the depression(s) that extend(s) outward in the direction of the tire shoulder situated closest to the spike.

5. The pneumatic vehicle tire as claimed in any one of claims 1 to 4, wherein the depression(s) that extend from the spike counter to the rolling direction during forward travel has or have an extent length (12) which is smaller than the extent length (11) of the depression(s) that extend(s) from the spike counter to the rolling direction during forward travel but which is greater than the extent length (13) of the depression(s) that extend(s) outward in the direction of the tire shoulder situated closest to the spike.

6. The pneumatic vehicle tire as claimed in any one of claims 1 to 5, wherein the depression(s) that extend(s) from the spike in the rolling direction during forward travel has or have a volume (Vi) of 12 mm3 to 13.3 mm3.

7. The pneumatic vehicle tire as claimed in any one of claims 1 to 5, wherein the depression(s) that extend(s) outward in the direction of the tire shoulder situated closest to the spike has or have a volume (V3) of 9.5 mm3 to 10.7 mm3.

8. The pneumatic vehicle tire as claimed in any one of claims 1 to 5, wherein the depression(s) that extend(s) from the spike counter to the rolling direction during forward travel has or have a volume (V2) of 10.7 mm3 to 12 mm3.

9. The pneumatic vehicle tire as claimed in any one of claims 1 to 6, the depression(s) that extend(s) from the spike in the rolling direction during forward travel has or have an extent length (11) of 4.9 mm to 5.2 mm.

10. The pneumatic vehicle tire as claimed in any one of claims 1 to 5, or 7, wherein the depression(s) that extend(s) outward in the direction of the tire shoulder situated closest to the spike has or have an extent length (13) of 3.7 mm to 4.2 mm.
Date Recue/Date Received 2021-02-02

11. The pneumatic vehicle tire as claimed in any one of claims 5 to 8, wherein the depression(s) that extend(s) from the spike counter to the rolling direction during forward travel has or have an extent length (12) of 4.2 mm to 4.7 mm.

12. The pneumatic vehicle tire as claimed in any one of claims 1 to 11, wherein the depressions have, at least over a major part of their extent, a depth (T1) of 0.5 mm to 1.0 mm.

13. The pneumatic vehicle tire as claimed in any one of claims 1 to 12, wherein the depressions that extend in and counter to the rolling direction are arranged in pairwise fashion and mirror-symmetrically about the same axis of symmetry (a2).

14. The pneumatic vehicle tire as claimed in claim 13, wherein the axis of symmetry (a2) runs at an angle (a) of -20 to 20 with respect to the circumferential direction.

15. The pneumatic vehicle tire as claimed in any one of claims 1 to 12, wherein a pair of depressions extends from the spike outward in the direction of the tire shoulder situated closest to the spike, wherein the depressions are arranged mirror-symmetrically about an axis of symmetry (a2).

16. The pneumatic vehicle tire as claimed in any one of claims 13 to 15, wherein the axes of symmetry (a2, a3) run perpendicular or substantially perpendicular to one another.
Date Recue/Date Received 2021-02-02