DE2939161A1 - MOTOR VEHICLE TIRES - Google Patents

Description

Motor vehicle tires

The invention relates to a motor vehicle tire with radial reinforcement, a band, a tread, Sidewalls that terminate in beads and two bead wires.

In theory, it makes the most economical use of the traction characteristics of those making up the tire body Materials for the wires in the body necessary for them in the most common types of tires, in radial planes of the The tire. However, if such a tire is subjected to a transverse load (rolling effect) -, deformation of the radial wires occurs in the part of the tire that is in contact with the ground. This rolling effect is accompanied by a secondary twisting effect on the wires in contact with the ground and the angle of distortion causes loss of lateral stability under normal operating conditions.

The tire manufacturers the radial wires inclined at a certain angle on both sides of the circumferential direction of the tire to build up a geodesic force field (tires with beveled folds, mostly referred to as ordinary tires). When a conventional tire is subjected to a rolling effect under a transverse tension, the twisting effect results the forces generated by the oblique pull in the beveled folds. The geodesic system of

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Construction thus has a self-stabilizing effect on the rolling effect of the tire caused by the Transverse pull has been effected. Nevertheless, the geodesic construction also has a disadvantage. Indeed produces the distortion of the rhombus formed by the beveled folds in the soil contact zone creeping between the folds, which gives a heating effect and sliding on the road, which gives the Significantly increased tire wear.

These disadvantages were partially eliminated with the introduction of the radial tire, the so-called "radial tire". The radial tire resumed the economical use of radial wires for the body and deformation the radial wires in the ground contact zone are prevented by a non-deformable band under the transverse tensile effect. With a rolling effect, both sides of the tire are subject to a twisting effect. Theoretically, that is subject to non-deformable band in the tread no angular deformation. The road grip properties of the tire are therefore a unique function of the development precision of the non-deformable with regard to the transverse stability Tape in the tread on the road to a limit value of the twisting effect on the sidewalls, the one Function of the tread adhesion to the road. Beyond this threshold, the tread loses its grip suddenly, ^ ies explains the well-known minor Transverse stability of radial tires.

Radial tires also have another well-known flaw, sidewall heating. Indeed subject to vertical tension (breaking effect of the

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fens) every wall has a buckling effect caused by a sudden change in the wall's radius of curvature between Wall and tread is marked. These are sudden changes in the radius of curvature evidently through strong heating of these two critical zones, which follows a repeated fracture effect. A similar heating occurs with transverse tension in the critical connection zone between, each wall and the tread. The heating can cause the tread to become detached in the critical joint zone between the walls and the running surfaces. The damping effect of a radial tire thus systematically causes a Warming, especially in the two critical zones on each wall, as indicated above. One of these Zones can have strong effects on the strength of the tire.

Despite the classic tires mentioned (conventional and radial tires), there are also so-called tubeless tires Tires that were invented at the beginning of this century. The air chamber or air chambers, round or oval, are quilted by beveled or radial wires, either by a wire winding or by a sheath Reinforced fabric. These tubeless tires have several advantages:

1. Enclosed air chamber, thus the so-called tubeless system »

2. In some tubeless tires, the wires are omitted as resistance elements.

3. The force fields in the tire body are balanced.

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This type of tubeless tire is described in French patents 2.052.885 and 2.34-8.066. The tires described there have the same defects as the radial tires with regard to heating of the walls (every wall also has critical zones there). For tubeless tires according to the French Patent 2,052,885 is also the error in the lateral stability with regard to the classic radial tire greater. In fact, the increase in lateral stability errors is that the section of the tire (seen in the radial section) can roll over itself under the effect of the transverse pull. On the other hand, owns that described in French patent 2,348,066 Tires have improved lateral stability in relation to the tubeless tires according to the French Patent 2,052,885 and on the classic radial tires, but the improvement in lateral stability is achieved with Disadvantage of steaming and at the cost of considerable heating of the elastic binding material between the air chambers obtain.

In fact, the ideal tire should therefore have the following characteristics:

1. Great vertical flexibility (steaming of the vertical pull of the tire).

2. Great rigidity or stability across as resistance to transverse stresses.

3. Lowest internal heating (body preferably with radial threads), no critical heating zone in the Walls).

The main aim of the invention is to provide a tire which satisfies these three conditions.

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In this regard the tire is characterized in that each wall, viewed in cross section, has a profile which corresponds to that of the upper part of the curve representing the equation (Figure 2) for classic radial tires:

-b)

with the upper part being between the points on the curve where the tangents are predominantly vertical or are horizontal and the metacenter of the upper part of the curve is practically the same vertical plane to a changing one Load is, χ the lateral distance from the radial (circumferential) centerline of the tire cross-section to a Point on the neutral carcass contour line, y is the radial distance from the axis of rotation of the tire to a point on the neutral carcass contour line, a is the radial distance from the axis of rotation to the neutral carcass contour line is on the radial (circumferential) center line of the tire cross-section, so that if y is equal to a, the value χ is equal to Zero and b the radial distance from the axis of rotation to the point of greatest cross-section, i.e. the maximum of x, is the neutral carcass contour line.

The hanging width 1 can be between 0.25 ^ and 1.4-5 L, where L is the width of the tread. The cross section of the tire can have an H / B ratio of 0.4 to 0.6, where H is the height of the cross section measured between the hanging diameter of the tire and

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the band and B represents the total width of the tire.
The whole system is such that the tire, seen in cross section, is an isostable triangle system
forms.

"Hanging width of the tire" means the distance between the bead hanging points on the edge for receiving the tire, ie the nominal width of the rim. "Hanging diameter"
means the diameter measured at the hanging bead point on the wheel rim, ie the nominal diameter of the rim.

Because of this design and the particular shape of the walls, the tire according to the invention is very vertical in the vertical direction flexible, very rigid in the transverse direction and there is no critical heating there.

The invention is described with reference to the drawings.
In these is:

Figure 1 is a partial cross-section of a tire according to the invention;

Figure 2 is a graph of the curve representing the equation for a classic radial tire and especially the
Parts of the curves representing the shape of the walls of a classic radial tire and the shape
determine the walls of the tire of Figure 1; and

Figure 3 is a diagram showing the reasons why the tire according to the invention has good transverse stability and good vertical stability.

The tire 1 in Figure 1 essentially contains the band

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the radial reinforcement J, the tread 4, sidewalls 5 that terminate in beads 6 each with semi-rigid Round wire 7 are provided.

The tire width 1, measured between points 9 »wo the beads 6 hang on the wheel rim 10 is approximately between 0.25 L and 0.45 L. where L is the width of the tread 4 is. The cross-section of the tire has the ratio W / H of about 0.4-0.6, where H is the height between band 2 and points 9 and B represents the total width of the tire.

The walls 5 have a profile similar to that of the upper part corresponds to the curve according to the equation given above.

This equation represents the well-known equation for a classic radial tires. The meaning of the individual parameters in this equation and the calculations with regard to this is in the publication "Tire Science and Technology TSTGA", Volume 1 No. 3, of August 1973, Pages 290 to 315 reproduced. The curve E after this Equation is shown in Figure 2. More precisely, the left wall 5 (FIG. 1) has a profile that corresponds to that of the arch CD in curve E in FIG. The point 9 lies near the point on curve E where the tangent to that curve is predominantly vertical or falls related to this point. The point D is close to the congruent with the top of the curve E where the tangent is predominantly horizontal to the curve. The right wall 5 has a symmetrical CD profile with respect to the left wall, based on the center plane XX (Figure 1).

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For comparison, the left wall has a classic one Radial tire has a profile similar to that of the arc AB in corresponds to curve E in FIG.

In addition, the location of points C (or C) and D on curve E is chosen so that the metacenter of arc CD (or CD) in curve E remains in the same predominantly vertical plane with varying loads. More precisely: the arch CD has a metacenter under a given load which corresponds to each location of the points C and D on the curve E. By changing the position of points C and D, the geometric location of the metacenter (metacenter curve) of the arc CD can be determined under a given load. For example, the geometric locations of the metacenter are designed for the lowest or highest loads. An arch CD can thus be found, the metacentres of which are located in the same predominantly vertical plane which determines the position of the points C and D for the profile of the walls 5 under the least load. Figure 3 shows (solid line) the arc CD ^ on the curve E,., That of the smallest load with the center of gravity G ^. and metacentre M ^. of the arc CD ,, and (dashed) corresponds to the arc CD ₂ on the curve Ep, which corresponds to the greatest load with the center of gravity G2 and the metacenter M2 of the arc CD2. The two points M ^ and M ~ lie in the same predominantly vertical plane . When choosing the position of the points C and D on the curve E, congruent metacentres M ^ and Mg can also be obtained.

The radial reinforcement 3 can be made of synthetic or metallic textiles in the usual way with rubberized cord threads

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29391S1

be provided. The tape 2 can be made of adhesive-treated fabric, synthetic or in the usual manner metallic textiles.

With the same described structure of the tire and the wall form 5, an isostable triangular system and obtain a tire with good lateral stability and good vertical flexibility. When the load changes pages 5 do not work because of their shape with buckling as in the case of a classic radial tire, but with bending and some or no angular distortion at all near the bead 6 and the connection zone between the wall 5 and the running surface A.

There is little or no warming in these zones and consequently there is no danger there the detachment of the beads 6 and the tread 4.

An embodiment of the invention is characterized in that, as Figure 4 shows, the outermost point P on the tread, the center point T in the cross-section of the bead area, which is on the same side of the tire median plane as the outermost point P is located, and the center 0 on the wheel are practically aligned when the tire is mounted on the wheel rim at nominal inflation pressure without external load, so that the profile the left side corresponds to the upper part CD of curve E, which corresponds to the equation for the tire inflated to nominal pressure without represents external stress. This lies between point C, where the tangent to curve E is predominantly vertical, and the point D at which the curve E makes an angle

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measured in the left direction with respect to the horizontal, so that φ = (J) + oC , where φ is an angle between about 5 and 15 ° and ^ the angle formed by the straight line OTP to the vertical. The profile on the left is obtained by turning part CD of curve E clockwise around point D at angle (X- , so that the tangent to point D at angle φ to the horizontal and the tangent to point C forms the angle * to the vertical , which is predominantly equal to the angle φ ~ at nominal inflation pressure without external load, so that the tangents to points D and C are predominantly horizontal or predominantly vertical under maximum external load. The right-hand side has a profile that is created in a similar way, so that it is symmetrical to the left with respect to the center plane of the tire.

The method of manufacturing the tire according to the invention is described with the aid of the figure which shows the shows the left half of the tire cross-section.

The following is done to determine the shape of the tire 1 and especially the shape of its sides 5 the rim 10 of preferably standardized dimensions and the nominal diameter of the tire at nominal inflation pressure but chosen without any external burden. These determine the position of the beads 6 and thus the wires 7 on the one hand and the height H of the cross section of the tire measured between the hanging point 9 and the band 2 or between the Point 9 and the outer diameter of the tread 4 according to the respective tire manufacturer.

The center 0 on the wheel is spliced with the center T in the cross section of one or both wires 7, for example

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wise the left wire in the drawing. The straight line OT intersects the baseline at P, which is the leftmost point of contact of the tread M with the ground. This thus determines the width L of the tread M. OC is the angle between the vertical and the line OTP. The angle X has a fixed value for the selected wheel rim.

Curve E, which represents the equation for the selected tire at nominal inflation pressure and with no external load, is then determined using the equation. Then point D on curve E is chosen so that the tangent of curve E at point D forms the angle φ which, measured in the left direction to the horizontal, is such that φ = φ- + oC , where φ ^ dör angle is approximately is between 5 and 15 ° and has the value shown above. It shows how to choose the value of the angle φ in the range shown below. The position of point D on curve E can easily be determined using the equation in the main patent. The following equation can be derived from the equation given above:

2 2 2 2 2 2 dy ^ (a - b) - (y - b)

- = = tg φ

2 2 "
^ta 7 - b

This equation can also be written in the form:

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2 2

y - b

COS

2 2
away

If φ equals φ ,, + (V can thus be the ordinate of the point D on curve E can be calculated using the last equation.

Since the point D has been determined, the curve E is drawn in on the drawing by plotting the point D on the line OTP exactly below the wire 7. The curve E is then rotated to the right around the point D at the angle ^y -. In this way the profile of the left wall 5 arises. Under these conditions the profile of the left wall 5 is such that the tangent to point D now forms the angle φ with the horizontal and the tangent to point G, which was before the curve was turned E at the angle '■ * - and the point D is predominantly vertical now forms the angle Φ2 with the vertical, which is predominantly equal to the Winkelet at nominal inflation pressure and without external load. The initial values of these angles formed by the tangents to points G and D are important for obtaining good stability of the tire when it is subjected to a fluctuating load in use. In this case, the profile GD in the wall 5 is deformed. For the tire, which is to be stable, the metacentre of the profile at GD in the tfand 5 must be shifted in a vertical or predominantly vertical plane during the deformation of the wall 5. Graphical recordings made in the laboratory for various values and orientations of the external load showed that this result was represented by an initial inclination φ 1 to the tangent at D and an initial inclination

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to the tangent at C can be obtained. Under increasing external load, the tangent tries to Point D to approach the horizontal during the deformation of the profile CD on the wall 5. The tangent to the Point D should not come under a maximum vertical external load from the other side of the horizontal. This therefore requires the choice of the value for the initial inclination (Jl the tangent to point D for a given Nominal inflation pressure. The greater the maximum vertical external load that the tires can carry, the greater is the initial slope φ ,, except when the nominal inflation pressure gets bigger. The choice of the value for the initial slope (J) ^. the tangent to point D is also one Function of flexibility, i.e. the vaporization capacity under fracture stress, obtained for the tire must become. The greater the flexibility or vaporization capacity that the tire must have, the smaller it is is the initial slope φ ^. The nominal inflation value and the Value of the initial inclination φ ^ of the tangent to point D. thus taking into account the value of the maximum vertical external load that the tire must bear and the Flexibility or the steam capacity required for the Tire is desired to be chosen. In general, an initial slope φ ^ with a value of about 5 is sufficient to 15 ° in order to meet the requirements set out above for obtaining good stability are.

With increasing lateral and horizontal external load, the tangent to point C inclines during the Deformation of the profile GD in the wall of 5 verticals to approach. It should not be subject to maximum lateral

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move away from the other side of the vertical, so that the metacenter of the profile GD during the deformation of the profile GD in a vertical or predominantly vertical plane remains. This is achieved in that an initial slope Qp of the tangent to Point G receives a value that is predominantly equal to the value of the angle <* ■.

Under these conditions, the tangents to points D and C on wall 5 remain below one in use maximum vertical, horizontal or inclined external load predominantly horizontal and predominantly vertical and consequently the metacentre of the profile CD remains on the wall 5 during the deformation of the wall 5 changing vertical, horizontal or inclined external loads in an at least predominantly vertical one Flat, and thus the greatest stability of the tire results.

Another advantage of the tire according to the invention is based on the fact that the rubber in the connection zone between the tread 4 and wall 5 is only weak Pressure is applied when the tire is subjected to a changing external load due to the alignment of points P, T and 0 and the particular shape of the wall 5 is exposed. Thus, the rubber in this connection zone heats up during Only little use and there is no risk of the rubber coming off between the tread 4 and wall 5.

Although only the left wall of the tire has been mentioned in the description, the profile can also

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of the right wall can be obtained in a similar manner, so that the right wall to the left with respect to the Center plane XX of the tire is symmetrical.

As the dimensions of the tire and the ^ orm of the right and links «and can be determined in this way the tire can actually be manufactured in the usual way.

It is clearly shown above that the tire obtained in this way is perfectly triangular and isostable system under changing vertical, horizontal or oblique external loads.

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Claims (2)

PATE N TAN WALTS BU R O ERLlN - MÖNCHEN * PATENTANWÄLTE DIPU-ING. W. MEISSNER DIPL-ING. P. E. MEISSNER DIPL.-ING. H.-J. PRESTING Professional Representatives before the European Patent Office Our symbols HERBERTSTR. 22, 1000 BERLIN 33 Λ ^ / A-GE-. 25.09. / β J ^ The Goodyear Tire & Rubber Company Akron, Ohio 44-316, USA claims 1. Vehicle strip with a reinforcement, a tape, a Tread, sidewalls, which run into beads, and two bead wires, characterized in that, that each wall (5) of the tire (1) has a transverse profile which corresponds to that of the upper part (CD) of the curve (E), which represents the following equation for a classic radial tire: - b
. dy 2 2 2 2 2 b) - (y -b) where the upper part (CD) between points (C and D) * Branch (§ 28 PaO) TELEX: TELEGRAM: PHONE: BANK ACCOUNT: CHECK ACCOUNT: Munich: 1 - 856 44 INVENTION BERLIN BERLINER BANK AG. W. MEISSNER, BLN-W St. ANNASTR. 11 INVEN d BERLIN 030/891 60 37 BERLIN 31 122 82-109 8000 MONKS 22 030/892 23 82 3695716000 TEL .: 089/22 35 44 on this curve, where the tangents are predominantly vertical and horizontal, so that the Metacentre of the top of the curve in the same predominantly vertical plane under a changing one Burden remains. , Tire according to Claim 1, characterized in that that the hanging width (1) of the tire (1) is between 0.25 L and 0.45 L, where L is the Represents the width of the tread (4), and that the cross-section of the tire has an H / B ratio of 0.4 to 06 where H is the width of the cross section measured between the hanging diameter of the tire and the Band (2) and B represents the total width of the tire and that the entire device is such that the tire mainly forms an isostable triangular system - seen in cross-section. Tire according to claim 1 of the main patent, characterized in that when mounted on a wheel rim under nominal internal inflation pressure without external load, the outermost point (P) on the tread (4-), the center point (T) in the cross section of the wire 7, which is on the same side of the median plane (XX) is located as the outermost point, and the center 0 of the wheel is aligned so that the profile of the left wall (5) corresponds to the upper part (CD) of the curve (E) which gives the equation for the under nominal internal inflation pressure represents no external load, and between the point (C), at which the tangent to the curve (E) forms an angle OC, which, measured in the left direction to the horizontal, is so large that ψ = φ ^ + ^, where ( J ^ an angle of - 3 030016/0737 about 5 to 15 ° and ^{v is} the angle formed by the line OTP with the vertical that the profile of the left wall (5) by rotating the part (CD) on the curve (E) around the point D at an angle ^ C is obtained in the right direction, so that the tangent to point D forms the angle φ ^ with the horizontal, that the tangent to point (C) forms the angle <J> ₂ with the vertical, where φ ~ at nominal inflation pressure and without external load predominantly is equal to the angle oc, so that the tangents to points (D and C) under maximum external load are predominantly horizontal and predominantly vertical, respectively, and that the right wall has a profile which is obtained similarly so that it is with respect to the center plane (XX) of the tire is symmetrical to the left. Tire according to the preceding claims, characterized characterized in that in a radial carcass tire each neutral contour line of the lower sidewall carcass has a profile from the point of maximum cross section of this neutral contour line to the bulge area, which corresponds to the curve represented by the equation of claim 1, wherein χ is the lateral Distance from the radial center line of the tire cross-section to a point on the neutral carcass contour line, y is the radial distance from the axis of rotation of the tire to a point on this line, a is the radial Is the distance from the axis of rotation of the tire cross-section, so that when a is equal to the value χ becomes zero, and b the radial distance from the axis of rotation to the point of maximum cross-section, i.e. the maximum χ of the neutral Contour line of the carcass is that part of the curve 030016/0737 between the points at which the tangents to the curve are practically horizontal at a value of y close to a and are practically vertical, that the point of contact with the vertical is practically the maximum point Cross-section of the neutral contour line and the point of contact with the horizontal practically the point at the bulge area, and the shape of the curve between the contact points corresponds to the profile between the point of maximum cross section and the bulge area, and that the profile of the neutral lower sidewall contour line of the carcass is such that the metacentre locations fall on a line that is practically radial to the tire cross-section when the profile when bending the Tire changes shape. Tire according to Claim 4, characterized in that that in the axial plane of the tire the edge of the tread on each side of the tire cross-section, this is the point of maximum tread width, and the intersection of the ratation axis and the radial centerline of the tire practically aligned with the center of the bead bundle on that side are and practically form straight lines, each of which forms an angle cc with the radial center line, that each the neutral contour lines of the lower sidewall carcass has a profile corresponding to part of the curve (E) according to the equation in claim 1, wherein a the radial distance from the axis of rotation of the neutral contour line at the radial center line of the tire cross-section, b is a value of the radius between the radius a and that of the bead seat shoulder of the wheel and χ the lateral Distance in a plane from a center line - 5 030016/0737 train and y is a radial distance in a plane from a reference perpendicular to the center line reference of the points of curve (E), the perpendicular reference lines giving the plane that the part of the curve serves for the neutral sidewall contour of the carcass which the part of the curve between the point of contact of a vertical line with the curve and a point between the horizontal lines at radial distance a and radial distance b is that this point is characterized in that the curve at this point makes an acute angle φ with the horizontal tangent line to the curve at Radius a forms that the angle φ forms a value of oc plus an angle of 5 to 15 ° and the point of contact with the vertical is at the point of maximum tire cross-section and whose point of contact is an acute angle φ to the horizontal tangent to the curve at a radius a which practically corresponds to the point at the bulge area that the curve shape between the tangent points corresponds to the pro fil corresponds to the neutral sidewall contour line of the carcass if the curve shape is aligned by rotating it through an angle around the point in the bead area in order to enlarge the apparent maximum cross-section of the tire, and that this shape of this line is characterized in that the metacenter points on fall a line that is practically radial to the tire cross-section when the tire changes shape when bent. - 6 030016/0737