DE102009044418A1 - Tire for e.g. lorry, has belt package provided with belt layers that are wider than tread width, and shoulder-like openings formed at sides of tread band, where one of layers lies radially outward and exhibits smaller width than tread width - Google Patents

Abstract

The tire has a belt comprising a belt package (1) that is provided with four belt layers (4-7), where the layers comprise reinforcements. The reinforcements are aligned in different angles and made of metallic material, and the layers exhibit effective belt width (3) for receiving high traction forces in circumferential direction. Shoulder-like openings are formed at sides of a tread band. One of the layers lies radially outward and exhibits smaller width than tread width, where the belt layers are wider than the tread width. The belt is designed as a four layered triangular belt.

Description

The invention relates to a vehicle tire for commercial vehicles, buses and trailers with a tread with a tread pattern, a tire carcass, side walls, tire beads with bead cores and a belt with mutually parallel reinforcements.

The belt of a truck tire usually consists of several superimposed belt layers with gegenläufigen slopes of the embedded strength member.

It is known to arrange a plurality of belt layers in truck tires one above the other, wherein the orientation of the reinforcing members intersect in the plan view in part. The width of the individual belt layers has a decisive influence on the driving characteristics and the rolling resistance of the vehicle tire.

The invention has for its object to provide a vehicle tire, wherein the belt structure and the tread width is optimally adapted to the forces acting on the vehicle tire loads.

The object is achieved according to the preamble and the characterizing features of claim 1.

Out DE 3313535 A1 It is known that the ratio of the belt width to the tread width, among other things for rolling resistance optimization is an important criterion. To ensure a high belt width to tread width ratio, the tire has shoulder-like, step-like, step-like, non-roadway spacers from which the sidewalls extend radially inwardly toward the tire beads,

In the cited patent, the entire belt package has been arranged so that the width of all the belt plies exceeds the width of the tread.

Surprisingly, it has been found that such an arrangement does not represent the optimum against the background of rolling resistance optimization.

• – einen langsamen und gleichmaßigen Abrieb zu gewährleisten oder
• – Sicherheit gegen das Durchdringen von in Profilrillen gefangenen Steinen sicherzustellen, gerecht werden kann, ist eine gewisse Menge an Festigkeitsträgern notwendig. Diese Festgkeitsträger sind üblicherweise Stahlkord, die Menge an eingesetztem Festigkeitsträgern ergibt sich aus der Anzahl der Gürtellagen, der Anzahl der Korde pro Gürtellage und dem Stahlquerschnitt pro Kord.

So that a belt its functions, such. B.

• - To ensure a slow and gleichmaßigen abrasion or
• - To ensure safety against the penetration of trapped in tread stones stones, can be fair, a certain amount of reinforcements is necessary. These Festgivitätsträger are usually steel cord, the amount of strength used is determined by the number of belt layers, the number of cords per belt layer and the steel cross section per cord.

The necessary amount of steel cord, so that the belt can fulfill its objective functions, so z. Example, for a 4-layer belt compared to a 3-layer belt can be achieved that for a belt with 4 belt layers a steel cord with a reduced diameter and / or a reduced number of cords per belt layer is used.

Subscores have shown that with the same amount of steel cord in the belt package, a 4-ply belt compared to a 3-ply steel cord then has a rolling resistance advantage if the width of the fourth belt ply does not exceed the width of the tread. In direct comparison of a 3-layer belt after DE3313535 with a 4 ply belt with equal amount of strength carriers, a rolling resistance advantage of 2% was surprisingly found for the 4 ply belt. Analyzes have shown that when the tire is loaded with the wheel load, the belt edges, when passing through the ground contact surface, are deformed substantially radially outwards where there is no support in the radial direction through the running surface. From rolling resistance view, it is advantageous if in this region of the strong radially outward deformation of the Stahlkordmenge is reduced, which can be achieved by the described arrangement of the 4-ply belt.

The second important parameter in the optimization of rolling resistance is the ratio of tread width to effective belt width. In DE 3313535 is described:
"It will be appreciated that a comparatively wide belt results in greater consolidation of the tread area compared to a narrow belt. Such solidification and stabilization of the tread zone may lead to a reduction in rolling resistance. "In this patent, the ratio of the belt width resulting from the width of the widest belt ply to the tread width has been described as the relevant ratio.

Surprisingly, recent studies have shown that not the belt width, this is reflected in the patent DE 3313535 results from the maximum width of the steel layers, but the effective belt width represents the relevance for the rolling resistance size. Tests have shown that a reduction in the ratio tread width to the effective belt width significantly improves the rolling resistance.

It has been shown by experiment that reducing the width of the belt cushions, which is located between the Gürftellagen with the crossed angle arrangement, leads to an improvement of the rolling resistance. Compared to a reference tire where the belt pad extends between the 2nd and 3rd belt plies, measured from the edge of the 3rd belt ply, 20 mm laterally to the middle of the belt, an otherwise identical tire with a belt pad 10 mm laterally could be used extending to the middle of the belt, the rolling resistance can be improved by 5%. The reference tire had a tread width to effective belt width of 1.36 and the test tire a ratio of 1.24.

On the basis of several embodiments, the invention will be explained in more detail. Show it:

1 : a belt package

2 : an embodiment

3 : a belt package with a zero grade belt layer

4 An embodiment with a rounded contour of the recess 10

5 An embodiment with a narrow recess 19

6 : an embodiment

7 : an embodiment

The 1 shows a belt package 1 ,

• 1. Gürtellage 4: 50° rechtssteigend (im Bereich: 45–70°)
• 2. Gürtellage 5: 18° rechtssteigend (im Bereich: 15–26°)
• 3. Gürtellage 6: 18° linkssteigend (im Bereich 15–20°)
• 4. Gürtellage 7: 18° linkssteigend (im Bereich 15–20°).

The belt package has z. Example, the following structure, which is counted radially outward:

• 1. belt layer 4 : 50 ° right-increasing (in the range: 45-70 °)
• 2nd belt layer 5 : 18 ° right (in the range: 15-26 °)
• 3rd belt layer 6 : 18 ° left (in the range 15-20 °)
• 4th belt layer 7 : 18 ° left (in the range 15-20 °).

The angle in degrees indicates the orientation of the strength members in the circumferential direction of the vehicle tire, d. h., perpendicular to the page.

The effective belt width 3 is the belt width, in which there is a high mechanical coupling of the belt layers between the working positions or individual belt layers.

The working positions or individual belt layers are the layers in which the reinforcements of the belt layers are in a crossed angle with opposite pitch direction to each other.

A decoupling is z. B. then, if between the working positions on both outer sides of an additional building part, z. B. a profile in the form of a belt pad 2 or a strip is inserted.

On the other hand, over the entire effective belt width there is a high mechanical coupling of the respective belt plies.

The working positions are in this case the 2nd and the 3rd belt layer 5 and 6 , The effective belt width 3 is for such a structure in 1 shown.

The effective belt width 3 is generally much narrower than the widest belt layer, the second position in this embodiment 6 is.

With more than two crossed belt layers, the effective belt width of the overall belt package results from the belt layers, which are the max. have effective belt width.

In a belt structure with a zero-degree belt layer, the width of the zero-degree belt layer represents the effective belt width, as in the 3 is shown. Ideally, the strength carriers consist of a metallic strength carrier, for. As steel, but not from reinforcements, which consists of a polymeric material.

If there are other belt plies crossed in a belt structure with a zero degree belt, the effective belt width of the overall belt package will be what is wider, either the effective belt width of the zero degree belt layer or the effective belt width the non-decoupled work situation.

Should belt layers of the vehicle tire be divided, ie a belt layer is not continuously present over the entire width of the belt package, then only the belt layers whose width is at least 25% of the tread width can be used in the determination of the effective belt width.

The tread width is the width of the tread between the two outer boundaries of the tread at the height of the center of the tread depth. Conventionally, conventional truck and bus tires have a tread width to effective belt width ratio greater than or equal to 1.3.

2 shows an embodiment of the construction according to the invention. The vehicle tire 14 includes a tread 9 , a belt package 1 and, among other things, a tire bead 12 , The tread 9 has a tread pattern and at its outer edge the recess according to the invention 10 , The dashed line 13 shows the contour of the Tire shoulder in a conventional comparable tire as known from the prior art. Through this material recess 10 in the tread 9 becomes the tread width 11 considerably reduced.

The tread width 11 is the width across the two outer edges of the tread 9 is measured in the height of the center of the tread depth. The provision of a recess 10 in the tread 9 is one way to effectively reduce the tread width, while also reducing the tread width to effective belt width quotient. At least the uppermost belt layer, that is, which is located radially outward, is narrower than the tread width.

The other embodiments are based on the principle, the effective belt width 3 to broaden and thereby get the quotient of tread width and effective belt width in the value range according to the invention. The in the 2 illustrated effective belt width 3 corresponds essentially to that in the 1 shown effective belt width.

Another embodiment is the belt pad 2 in the 1 to reduce in width, preferably to a width between 10 mm and 15 mm. Again 1 can be seen, thereby the effective belt width 3 widened in a simple way.

Another embodiment is to widen the belt package as a whole, whereby the quotient of tread width and effective belt width is also reduced, it being important to ensure that at least the uppermost belt layer is narrower than the tread width.

The 4 shows an embodiment with a rounded contour 18 the recess 10 ,

The 5 shows an embodiment with a narrow recess 19 in the tread 9 ,

LIST OF REFERENCE NUMBERS

1

belt package

2

belt cushion

3

Effective belt width

4

fourth belt layer

5

third belt layer

6

second belt layer

7

first belt position

8th

radial alignment

9

tread

10

Recess in the tread

11

Tread width

12

tire

13

Dashed line: contour of the tire shoulder in conventional comparable tires

14

vehicle tires

15

Striped zero-degree belt layer

16

tire Zenith

17

Zero degree belt layer

18

Rounded contour of the recess

19

Narrow recess

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been 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.

Cited patent literature

• DE 3313535 A1 [0006]
• DE 3313535 [0011, 0012, 0013]

Claims (12)

Vehicle tires for utility vehicles with a tread ( 9 ) with a tread pattern, a tire carcass, sidewalls, tire beads ( 12 ) with bead cores and a belt with mutually parallel reinforcements, wherein the belt is a belt package ( 1 ) and this belt package ( 1 ) a plurality of superimposed individual belt layers ( 4 . 5 . 6 . 7 ) with reinforcing elements oriented at a different angle and an effective belt width ( 3 ), the effective belt width ( 3 ) the belt width ( 3 ), which is particularly suitable to receive high tensile forces in the circumferential direction, characterized in that on both sides of the tread shoulder-like, formed by steps, with the roadway not in contact recesses ( 10 ) are arranged, from which the side walls radially inwardly to the tire beads ( 12 ) and the belt package ( 1 ) from 4 to 6 superimposed individual belt layers ( 4 . 5 . 6 . 7 ) is formed with strength members oriented at a different angle, at least the radially outermost belt position (FIG. 4 ), a width smaller than the tread width ( 11 ) and at least one belt layer of the package wider than the tread width ( 11 ). Vehicle tire according to claim 1, characterized in that the radially outermost belt layer ( 4 ), has a smaller width than the tread width and all other belt layers ( 5 . 6 . 7 ) of the package are wider than the tread. Vehicle tire according to claim 1 or 2, characterized in that the width of the two individual shoulder-like, formed by grading, not coming into contact with the roadway recesses, from which extend the side walls radially inwardly towards the tire beads, based on the tread width , each 2.5-20% of the tread width ( 11 ) turn off. Vehicle tire according to one of the preceding claims, characterized in that the width of the two individual shoulder-like, formed by grading, with the roadway not coming into contact recesses, based on the tread width, each account for 5-20% of the total tread width. A vehicle tire according to any one of the preceding claims, characterized in that the belt is a four-ply three-ply belt, radially directed from inside to outside in a counting manner and a pitch angle of the reinforcements in the belt plies relative to the central equatorial plane of the tire, the first belt ply has a pitch angle of 45-70 °, the second belt ply has a pitch angle of 15-26 ° with a pitch direction corresponding to the 1st belt ply, the third belt ply has a pitch angle of 15-24 °, the pitch direction being opposite to the second belt ply, and the fourth belt ply has an angle of 15-24 °, wherein the pitch direction may be corresponding to or opposite to the third belt ply, the width of the fourth belt ply being 30-95% of the width of the third belt ply should correspond. Pneumatic vehicle tire according to one of the preceding claims, characterized in that the belt contains at least one belt ply whose pitch angle of the reinforcing member, relative to the central equatorial plane of the tire, is 0 ° -5 °. Vehicle tire according to one of the preceding claims, characterized in that the quotient of the values of the tread width ( 11 ) and the effective belt width ( 3 ) lies in the value range between 0.9 and 1.25. Vehicle tire according to one of the preceding claims, characterized in that the quotient of the values of the tread width ( 11 ) and the effective belt width ( 3 ) in the value range between 0.9 and 1.15, preferably between about 0.9 and 1.1. Vehicle tire according to one of the preceding claims, characterized in that measured in Reifenzenit the distance between the individual belt plies should be approximately equal. Vehicle tire according to one of the preceding claims, characterized in that the tread ( 9 ) in its two outer regions in the radial direction ( 8th ) above the belt package ( 1 ) a recess ( 10 ), wherein the tread width ( 11 ) is about 60% to 75% of the tire width Vehicle tire according to one of the preceding claims, characterized in that the belt package ( 1 ) at least 4 belt layers with a belt pad ( 2 ) between the supporting belt layers, wherein the width of the belt pad ( 2 ) extending laterally to the middle of the belt between the two supporting belt plies, lies in a range of between 10 and 15 mm, preferably about 10 mm, measured inwardly towards the Reifenzenith from the edge of the third belt ply. Vehicle tire according to one of the preceding claims, characterized in that the strength members of the zero-degree belt layer consist of a metallic material.

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