CN105882322B

CN105882322B - Pneumatic tire for vehicle

Info

Publication number: CN105882322B
Application number: CN201610087520.XA
Authority: CN
Inventors: 乌尔里希·贝尔; 比约恩-比尔克·格莱泽; 布兰卡·梅嫩德斯-奥马萨; 奥利弗·许尔曼; 丹尼尔·内特; 安德列亚斯·多姆沙伊特
Original assignee: Continental Reifen Deutschland GmbH
Current assignee: Continental Reifen Deutschland GmbH
Priority date: 2015-02-16
Filing date: 2016-02-16
Publication date: 2020-02-21
Anticipated expiration: 2036-02-16
Also published as: CN105882322A; DE102015202746A1

Abstract

A pneumatic vehicle tire with a tread has at least two circumferentially annularly encircling tread regions of defined width, such as tread ribs (1, 2), each consisting of circumferentially successive tread elements of the same geometric shape, so-called pitches (P1 to P5, P1 'to P5'), which are arranged in at least three different circumferential lengths (L1 to L5, L1 'to L5'), the arrangement of the pitches (P1 to P5, P1 'to P5') in the respective tread regions on the tire circumference being carried out in the order of their own pitch optimized for noise, the sum of the pitches (P1 to P5, P1 'to P5') in at least one annularly encircling tread region differing from the sum of the pitches in at least one other annularly encircling tread region. The total number of pitches (P1 to P5) in the tread areas having the greatest total number of pitches is at most 3% greater than the total number of pitches (P1 'to P5') in the tread areas having the smallest total number of pitches.

Description

Pneumatic tire for vehicle

Technical Field

The invention relates to a pneumatic vehicle tire with a tread having at least two circumferential tread regions of defined width, for example, tread ribs, which are each assembled from geometrically homogeneous tread elements arranged circumferentially one above the other, so-called Pitches (Pitches), which are arranged in at least three different circumferential lengths, wherein the arrangement of the Pitches on the tire circumference in each tread region is optimized for noise according to an own arrangement in each tread region

The pitches are ordered, wherein the total number of pitches in at least one circumferentially surrounding tread area is different from the total number of pitches in at least one other circumferentially surrounding tread area.

Background

Common in the formation of shaped parts of treads for pneumatic tires for vehicles are: in order to have a favorable effect or to reduce or optimize tire/road noise, the thread segments of the same type, i.e. the pitches, arranged one above the other on the circumference of the tire are assigned different circumferential lengths. In the tread, the pitches are usually provided with three to five different circumferential lengths, the length ratios of the pitches to one another being predetermined and being obtained by means of a suitable calculation program according to the most noise-favorable sequence of arrangement, i.e. the pitch sequence.

There are numerous solutions in the patent literature on the subject of the pitch and the pitch sequence of the tread. A pneumatic vehicle tire of the type mentioned at the outset is therefore known, for example, from EP 0114594B 1. The tread of a pneumatic vehicle tire has two tread regions extending in each case in one of the tread halves and encircling in an annular manner, the pitches of the respective identical configurations of the tread regions being arranged in a pitch sequence, the total number of pitches differing by 5% to 50%, in particular by 10% to 30%. From EP 0412952B 1 a pneumatic vehicle tire with a profiled tread is known, which tread is assembled from at least two pitches of the same type having different circumferences, the arrangement of the pitches on the circumference of the tire being carried out according to a pitch sequence that is optimized for noise. Within this pitch sequence there are at most two of the following pitches: the length of these pitches is either smaller than the length of the second shorter pitch or greater than the length of the second longer pitch. The main purpose of these known solutions is to achieve a distribution of the frequencies determined and generated in the tire/road noise over a wider frequency band.

The use of the determined pitch sequence, pitch length ratio and/or two or more pitch sequences in different thread regions of the tread can now be calculated to give a light or low tire/road noise, whereas in practice the pitch sequence and the pitch length in one tread are not arbitrarily combined with one another, since the result may be, for example, uneven wear or poor hydroplaning behavior.

Disclosure of Invention

The invention is based on the object of configuring a pneumatic vehicle tire of the type mentioned at the outset with a tread in such a way that the subjective perception of tire/road noise is substantially improved, wherein further tread properties which are desirable, in particular uniform wear of the tread, are to be ensured.

According to the invention, the proposed aim is achieved in such a way that the total number of pitches in the tread areas with the largest total number of pitches is at most 3% greater than the total number of pitches in the tread areas with the smallest total number of pitches.

A particularly smooth excitation spectrum (angelsgektren) can be generated by the tread having a circumferentially encircling tread region with a different total number of pitches (which differ only slightly from one another). This measure also allows the pitch sequences to be configured "similar" to one another and to match one another well. A slight difference in the total number allows to arrange the same type of tread elements in these tread areas in such a way that there is a stiffness distribution throughout the tread, which is used for a uniform wear of the tread.

In a preferred embodiment of the invention, the different total number of pitches in the tread band regions has one or more of the numbers 1 to 5 as common divisor. This measure particularly effectively avoids sub-harmonics (Subharmonischen) "of different pitch sequences falling on top of one another (afeinander fallen)". First of all, it can be avoided by small common divisor numbers (approximately numbers 1 to 5) that, in these excitation spectra arranged in different pitch sequences, spectral regions with increased excitation meet one another.

In this context, an embodiment of the invention is particularly advantageous in which the different total number of pitches in the tread regions has only the number 1 as a common divisor.

A particularly light tire/road noise is also achieved in that the tread has two tread regions with different pitch sequences, wherein the total number of pitches in the tread regions differs from one another by at most two pitches.

It is also advantageous in the layout of the tread according to the invention that the number of pitches of different length in these tread areas is at most seven, in particular that the number is at most five. In the case of more than seven pitches of different lengths, the geometric layout and arrangement of the pitches of different lengths on the circumference of the tire becomes relatively complex, an embodiment with at most five pitches of different lengths being optimal.

Further optimization of the tire/road noise can be achieved by special, additional measures and configurations. For example, these measures include: the number of pitches of different length in one tread area is different from the number of pitches of different length in one other tread area.

Within the scope of the invention, the tread may be geometrically variable in configuration, and in these individual tread regions, depending on the requirements set forth, circumferential sipes, transverse sipes, incisions and the like may be implemented. It is thus possible in particular for the tread to have at least two tread regions of the configuration according to the invention, wherein the pitches in the tread regions are geometrically of the same type. In another embodiment, the tread may have at least two tread regions configured according to the invention, wherein the pitches in the tread regions are geometrically differently configured.

Further, advantageous measures can help to optimize the stiffness distribution on the tread and in particular ensure uniform wear. For example, these measures include: the ratio of the length of the longest pitch to the length of the shortest pitch is 1: 1.4. A further advantageous measure in this context is that the total number of pitches in that tread region with the smallest total number of pitches is at least 90, in particular at least 120.

Drawings

Further features, advantages and details of the invention are explained in more detail below with the aid of a drawing of an exemplary embodiment. The only figure here, fig. 1, shows a partial view of the circumferential region of the tread of a pneumatic vehicle tire.

Detailed Description

In fig. 1, a tread of a pneumatic vehicle tire shows a rib 1 and a further rib 2 in the form of a radial structure for passenger cars, trucks and similar vehicles, which are separated from the rib 1 by a wide circumferential groove 3 running in the circumferential direction. Instead of the rib, a circumferential row of blocks may also be provided in the circumferential direction. In the embodiment shown, a further circumferential groove 3' running circumferentially runs along the tread rib 2 on the inside of the tread, with a male groove, not shown, adjoining the circumferential groove. Both the

ribs

1 and 2 are block-shaped, the ribs 1 being formed by transverse sipes 4 and the ribs 2 being formed by transverse sipes 5. In the embodiment schematically illustrated in fig. 1, the lateral sipes 4 extend in such a way that they end inside the tread at a distance within the sipe rib 1 and thus before the circumferential sipe 3, extend outside the tread beyond the lateral edge of the bottom supporting face width B of the tread (which lateral edge is indicated by a dashed line) and stop in this region, i.e. outside the tread. The ground-contacting portion of the tread conforms to a Footprint (Footprint) determined statically according to the e.t.r.t.o. standard (load at an internal pressure of 2.5 bar at 70% loading capacity, 85% internal pressure of 2.5 bar). The transverse sipes 5 in the sipe rib 2 are exemplarily in the form of spline-groove-like (sacknutartig) ending transverse sipes within the sipe rib 2, which open into the circumferential sipe 3'. The course of these

transverse grooves

4 and 5 is not the subject of the present invention and is therefore not described in detail.

The tread rib 1 forms a first tread area which is annularly circumferential and extends in the circumferential direction (occupies a portion of the width B of the tread); the tread rib 2 forms a second circumferentially encircling tread region which is likewise circumferentially encircled by a portion of the base support surface width B of the tread. The

tread ribs

1 and 2 are each assembled from tread elements of the same type, which are arranged adjacent to one another in the circumferential direction and are successive to one another, and which are also referred to as the tread step length (profischritte) or pitch. In the embodiment shown, the pitch boundaries between these pitches are each located approximately in the middle between the

transverse grooves

4, 5 which follow one another in the circumferential direction and follow the course of the

transverse grooves

4, 5. However, the pitch boundaries can also be placed at another location, for example at the edges of the

transverse grooves

4 and 5, respectively, which are located identically with respect to the circumferential direction. The pitches in each of the illustrated tread zones have their own geometric configuration, however it is also possible that the geometric configurations of the pitches in the tread zones are identical.

The division of the tread elements at different circumferential pitches (pitches are arranged in a so-called pitch sequence, which is derived by calculation, on the circumference) is common and serves the following purpose: the tire/road noise is minimized or optimized and the audible frequencies generated when the tire rolls are distributed or generated in such a way that they interfere as little as possible with the human hearing.

In the illustrated embodiment, the pitch sequences in the rib 1 and in the rib 2 are each assembled from as many pitches of different length, according to fig. 1 by way of example from the pitches P1 to P5 and P1 'to P5' with circumferences L1 to L5 and L1 'to L5', wherein the pitch sequence and the total number of pitches P1 to P5 in the rib 1 differ from the pitch sequence and the total number of pitches P1 'to P5' in the rib 2. In the embodiment shown in fig. 1 with five different circumferences L1 to L5 and L1 'to L5', the ratio of the lengths of these circumferences is as follows: the ratio of the length L1 or L1 'of the shortest pitch P1 or P1' to the length L5 or L5 'of the longest pitch P5 or P5' is 1: 1.4. The ratio of lengths L1, L2, L3, L4 and L5 and lengths L1 ', L2 ', L3 ', L4 ' and L5 ' to each other is preferably 1:1.1:1.2:1.3: 1.4. In contrast to the embodiment shown, three to seven pitches of different circumference can preferably be provided, with a length ratio of 1:1.4 between the shortest and the longest pitch. If there are a determined number of pitches of different length with a defined circumference in one tread area, the same number of pitches of different length may be used in this/these further tread areas. However, a different number of pitches of different lengths can also be provided in the individual thread regions.

The total number of pitches in one tread area 1 differs from the total number of pitches in the second tread area 2 by at most 3%, which means that the tread area with the greater total number of pitches has a pitch at most 3% more than the other tread area. Possible rounding at the "full" pitch is carried out in accordance with DIN 1333. Of the three or more tread regions having different pitch orders in the tread, the tread region having the largest total number of pitches has a pitch at most 3% greater than the tread region having the smallest total number of pitches. The embodiment of the tread with two tread regions having a different pitch sequence is now particularly advantageous, wherein the tread region having the greater total number of pitches has a pitch which is at most two pitches, in particular one pitch, greater than the other tread region.

The total number of pitches in the width-defined tread region provided in an annularly encircling manner (which in the embodiment shown is exemplary the two tread ribs 1 and 2) is preferably designed in such a way that the different total numbers have one or more of the numbers 1 to 5 as common divisor, and in a preferred embodiment it is particularly advantageous if the total numbers have only 1 as common divisor. These measures avoid that the sub-harmonics of the two pitch sequences "fall on each other". As already mentioned, by means of a small common divisor or by means of a design with only 1 as common divisor, it is avoided: regions with increased excitation in the excitation spectra of the two pitch sequences meet one another. This measure is advantageous in particular in the case of thread regions having a relatively high total number of pitches (in particular >90 total number, particularly preferably >120 total number), since the number of common divisor generally also increases with the total number of pitches in a thread region. The total number of pitches in one tread area formed in the tread is then for example 144 and the total number of pitches in a second tread area formed is 145.

The inventive concept is thus used in treads having or consisting of two circumferentially surrounding tread regions, wherein a tread region can also comprise two or more tread ribs, rows of tread blocks and the like. The concept according to the invention can of course also be used in treads having more than two circumferentially encircling tread regions with different pitch sequences.

Description of the reference numerals

1, 2 Ribs

3, 3' circumferential grooves

4, 5 transverse grooves

Width of supporting surface of ground

Circumference of L1 to L5

Perimeter L1' to L5

P1 to P5 pitch

P1 'to P5' pitch

Claims

1. Pneumatic vehicle tire with a tread having at least two circumferentially annularly encircling tread regions of defined width, which are each assembled from geometrically homogeneous circumferentially successive pitches (P1 to P5, P1 'to P5') which are arranged in at least three different circumferential lengths, wherein the arrangement of the pitches (P1 to P5, P1 'to P5') on the tire circumference in each tread region is carried out according to a self-optimized pitch sequence which is optimized with respect to noise, wherein the total number of pitches in at least one circumferentially encircling tread region differs from the total number of pitches in at least one further circumferentially encircling tread region,

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

the total number of pitches in the tread areas with the maximum total number of pitches is at most 3% greater than the total number of pitches in the tread areas with the minimum total number of pitches.

2. The vehicle pneumatic tire of claim 1, wherein the tread area is a tread rib.

3. A pneumatic vehicle tyre according to claim 1, characterized in that the total number of different pitches in the tread areas has one or more of the numbers 1 to 5 as common divisor.

4. A pneumatic vehicle tyre according to claim 1, characterized in that the total number of different pitches in the tread band regions has only the number 1 as a common divisor.

5. Pneumatic vehicle tire according to claim 1, characterized in that the tread has two tread regions (1, 2) with different pitch sequences, wherein the total number of pitches in the tread regions (1, 2) differs from each other by at most two pitches.

6. A pneumatic vehicle tyre according to claim 1, characterized in that the number of pitches of different length in the tread areas is at most seven.

7. A pneumatic vehicle tyre according to claim 1, characterized in that the number of pitches of different length in the tread areas is at most five.

8. A pneumatic vehicle tire according to claim 1, wherein the number of pitches of different lengths in one tread region is different from the number of pitches of different lengths in one other tread region.

9. A pneumatic vehicle tire according to claim 1, wherein the tread has at least two tread regions, the pitches being geometrically homogeneous in the tread regions.

10. A pneumatic vehicle tire according to claim 1, wherein the tread has at least two tread regions, the pitches being formed geometrically different from each other in the tread regions.

11. A pneumatic tire for vehicles as in claim 1, wherein the ratio of the length of the longest pitch to the length of the shortest pitch is 1: 1.4.

12. A pneumatic vehicle tire according to claim 1, wherein the total number of pitches in that tread area having the smallest total number is at least 90.

13. A pneumatic vehicle tire according to claim 12, wherein the total number of pitches in that tread area having the smallest total number is at least 120.