FI106784B - Vehicle tire with treads with axially extending grooves and corrugated groove plate - Google Patents

Description

, 106784

Vehicle tire with treads with axially extending grooves and corrugated groove plate

The invention relates to a tire of a vehicle having at least 5 axially peripheral treads having substantially axially extending grooves on the tread, arranged in a wavy manner such that the ridges and soles of the wave are substantially straight, extending obliquely in the transverse plane. Such rings are known. Substantially axial grooves, also referred to as transverse grooves within the scope of this application, do not substantially run, as is known in the art, in the axial direction but in the axial direction at an angle of 10-60 °. If the tread of the tire is provided with transverse dimensions, they preferably travel - as is known per se • · y · '- substantially in the direction of these transverse dimensions.

♦ «; / '15 Rubber between the grooves is usually called a lamella.

• «» * · ♦ »· ';.: In principle, grooves reduce stiffness, especially against forces acting perpendicularly to these grooves. The transverse grooves thus reduce in particular the longitudinal stiffness. Deterioration of the tread results in • 9 I! 20 more precisely adapts to the roughness of the carriageway gravel, allowing greater frictional traction.

In addition, a traction effect is observed especially on snowy roads, which may be due to the fact that the bending of the lamellas, which is already present at low longitudinal forces, acts on the end faces of the lamellas extending to the gravel. position so that they do not stand straight but at the edges.

It has been shown that the oblique position of the end surface of the fins reduces the braking distance on a wet road. A disadvantage of this is the particular lack of modern winter tires, since in low-snow but heavy rainy winters it is more important to have good braking on wet roads rather than snow.

Good grip is also expected on a dry road, such as a summer tire.

2 106784

Part of this set of requirements is influenced by the ever higher tuning speeds of the vehicles and the increasing displacement of H and V and Z tires by Q and S tires (Q = allowed up to 160 km / h, S = up to 180 km / h). h, T = to 190 km / h, H = to 5 210 km / h, V = to 240 km / h, Z = up to 240 km / h) because to avoid harmful temperatures the tread is generally poorly conductive inside H- , V and Z tires generally require rubber blends that, unfortunately - regardless of rain - have a significant cure at low temperatures, resulting in a corresponding reduction in frictional values, so for safety reasons, even on snow-free roads, winter tires are required, not mandatory.

,! ; From the well-established winter tires, the braking action on wet roads I, 'should be improved such that the number of grooves, especially the number of transverse grooves, is reduced. 15 nenee. However, in this case, the weaker behavior in the snow must be taken into account.

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French Patent No. 791,250 (1935) discloses a vehicle tire. . with treads having a substantially axial peripheral area. ·. 20 axial grooves, which are wavy with the ridge and bottom of the wave straight, extending obliquely to transverse the grooves; : when traveling in a plane radially outwards, axially outwards • · * ·.

The object of the invention is to increase the possible braking deceleration on a wet road surface, thereby reducing the possible thrust acceleration in the snow with little or no effect, and to achieve good lateral grip.

The object is solved according to the invention in that the chamfering of the wave ridges and the bottoms 30 is oriented such that axially inwardly traveling radially inwardly radially outwardly along the wave ridges or bottom of the grooves is achieved.

3, 106784

Previously, it was assumed that the slope direction of the wave ridges and bottoms would have little effect, and if it did, the reverse would be beneficial to the whole. Surprisingly, it has now been found that the exact opposite of the French patent 791,250 results in the most advantageous combination of features.

In the transverse plane, the ridges and bottoms of the waves are preferably between 20 ° and 70 °, preferably between 30 ° and 50 ° with respect to the radius.

The invention is based on the finding that a slight oblique position of the end faces of the lamellas is sufficient for drawing in the snow, which, however, must be achieved with slight longitudinal forces. However, when braking on a wet road, much higher accelerations are possible than those of the prior art. * 'With tires results in much greater bending of the lamellae and consequent; . . 15 in a skewed position on the end faces of the lamellae when required to pull in the snow. In addition, it was found that the greater the oblique position • · «of the lamella end faces, the greater the reduction in deceleration on the wet road. Thus, the inventor got the idea that the highly progressive, ... spring curve of the lamellae could at least reduce this described contradiction, even. · ·. 20 completely overrule it. The small progression is in conventional grooves such that '' 'adjacent lamellae after a given deflection and after exceeding the groove thickness' ;;; 'Rely on each other. However, they can then slide over each other.

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An essential part of the invention is to prevent this slipping by the shape-tightness, and thus reduce the tendency of the lamellae to bend below a threshold that can be determined by thickness.

As a form-fitting means, consideration was first given to changing the direction of the wave ridges and bottoms from a known beam direction to an axis direction. Although, in this case, the shape compactness could be achieved and also had a positive effect on the relationship between wet braking and snow traction, but the lamellae produced in this manner proved to be softer in the radial direction and tend to form bumps in the axial direction. The first aspect 106784 4 ka increases the resistance to rotation and the second reduces the maximum transverse acceleration, especially on a dry road. In addition, the shaped cutting dampers provided with this cause problems when closing and opening the vulcanization mold.

5 The inventors discovered that the slanting direction of the wave ridges and bottoms should allow for nearly the same shape density as the axial direction alone. Similarly to the known and well-established doctrine of making axially outer longitudinal grooves inclined in the transverse plane so as to travel radially outward and axially 10 outwardly, thereby providing optimum transverse and advantageous longitudinal retention, it was first assumed that arranges oblique grooves. . also in the direction that they would travel in the radial direction. ; outwards and axially outwards. However, this did not achieve the desired results. However, the hard-core inventor did not settle for this unpleasant surprise and, contrary to the usual perceptions of those skilled in the art, experimented with the invention, namely in the opposite direction of the grooves, and obtained surprisingly good results.

. · · ·. The point at which the compression spring begins and which causes the characteristic of the bending spring. ·. The 20 curve folding point is substantially determined by the relationship between the third depth of the groove depth and the first power of the groove depth. Depending on the groove density, groove depth, and rubber hardness, the advantageous point of bending is obtained, "'when the groove depth is between 0.3 and 1.0 mm. It is considered advantageous that these groove depths already move ♦ • ·« * ·: ·] in a known region which facilitates the changes caused by the invention.

Particularly in the case of heavily-laminated passenger car winter tires, which currently have normal groove depths of between 0.5 and 0.6 mm, the optimum groove width seems to be slightly less than this, namely about 0.4 mm.

The improvement in wet braking is particularly evident if the grooves arranged in the axially inner region are shaped according to the invention.

30 6 106784

The invention further relates to a groove plate according to the preamble of claim 5, which is characterized by the features set forth in the characterizing part of claim 5.

In order to carry out the tires according to the invention, it is not necessary to make changes to the tire blanks. All that is needed is different vulcanization molds. Instead of the known groove plates, vulcanization molds are fitted with groove plates in which the ridges and bases of the waves are inclined to the fixing edge of the plate. Instead of first stamping and then bending the sheets into a wave shape, due to the bevelled position of the ridges and bottoms of wave 10, and thus the different lengths of the different ridges and bottoms, it seems appropriate to first bend the larger sheets to the desired waveform; separate groove plates - now obliquely to the edges of the semi-finished plates ♦ «« '.

* «,: V! 15: 'y The invention will now be explained in more detail by means of three figures. Plotter- «I« '! Fig. 1 is a perspective view of a tire according to the invention; Figure 2 shows the same ring in enlarged cross-section in Figure 1 ';:;' along the indicated cut line; t (: .i .: Fig. 3 shows a plurality of plate pieces according to the invention which is * * 25 to be fastened to a vulcanization mold for making grooves according to the invention; and Figs. 4 illustrate the operation of the invention; Figure 4b shows, in the same representation, the same profile section under the influence of the longitudinal forces, and Figure 4c shows the change in the curve of the lamella bending spring 5 caused by the invention.

Fig. 1 is a perspective view of the tread pin 2 of the tire 1 of the invention, which is viewed from the top. a thick dashed line represents a cut line 10 along the groove 3 for the representation of Figure 2.

,, Fig. 2 is an enlarged view of the same ring 1, but cut in a transverse plane along a groove 3 instead of a perspective view. The wavy ridges 4 and the wavy bottom 5 wavy surfaces appear as thin, solid lines that are not drawn to the edges of the respective thighs in thick conventional lines according to the conventional presentation, and which are otherwise known as a wavy groove according to the invention. according to the position, are inclined in this position towards the beam 6. In this embodiment, the angle P of the bevel is 45 '.

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However, as stated herein, the oblique position of the wave ridges 4 and the soles 5 according to the invention preferably extends over the entire width of the tread 2, if any. is equipped with a groove, this oblique position is particularly important at the edge of the tread 2 on both sides * and · Lja R.

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According to the invention, the oblique position of the wave ridges 4 and the bottoms 5 is oriented as shown herein, i.e. when moving along the wave ridges 4 or the bottom radially from the inside outward, the axially inward end is reached. For symmetrical tires, the change of direction should be in the mid-range M.

Fig. 3 is a perspective view of one of the sheet members 7 according to the invention, which is to be secured to a vulcanization mold for making the grooves of the invention. Fixing elements known per se, here apertures 17 arranged near the lower edge 18 of the plate, are provided for mounting.

For ease of understanding, the front and rear faces of the plate 7 are drawn radially standing 5, although preferably, as is known, at least in the case of the pouches, running slightly obliquely with respect to the radius, as shown in Figure 2. The ridges 4 and the bottoms 5 of the wave are known to be straight, but at an angle P to the radius 6.

10 For further clarification, the respective cutting surfaces 9a and% are drawn in dashed lines perpendicular to the main dimension 8 of the plate body 7. The main dimension 8 of the plate body 7 may be in the angular range. *; ' 1a ± 45 ° with respect to the axis direction herein, preferably between 20 and 30 °.

;, 'The wavelength along the axis is indicated below.

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4 4. ". ' Figures 4 illustrate the operation and effects of the invention: 1 «\

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Fig. 4a shows the longitudinal section of the profile section under the influence of longitudinal air forces. <·., Ta. The cutting plane corresponds to the one which led to the cutting of the plate 7 in the previous figure.

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20 to 9b, and which is substantially axial to the ring. As a result, only one half wave is visible here. For the purpose of explaining the principle of operation, this ;;; however, it is sufficient:

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The profile column is divided by slots 3 into sections 10. Each section 10 ♦: 25 has a front running surface 11 and a rear running surface 12. Because the wave ridges and soles - when their dimension is separated radially and axially - according to the invention also have axial components. , in addition to the radial surfaces 15 known per se, there are substantially circumferential surfaces 13 and 14 in the longitudinal section.

Fig. 4b shows in the same representation the same profile section with the braking force F applied. Importantly, the sub-surfaces 14 of the forwardly extending lamellae surfaces 11 substantially rest on the sub-surfaces 13 of the trailing lamellae surfaces 12 88. In addition to the deformation represented by the angle a, the oblique position of the lamella end faces 16 relative to the circumferential direction and 14 touch each other, other deformation is prevented.

5

In order to prevent further deformation in the known corrugation orientation, namely in the radial direction, it is also contemplated that the radial surfaces are in contact with each other, but the deformation obtained in this manner is weaker than the wavy ridges and soles of the invention. For the sake of clarity, the width s of the grooves in Figures 4a and 4b is exaggerated so that the radial portions 15 of the surfaces 11 and 12 only touch each other with a much larger

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deformation like the part surfaces 13 and 14 which also have a component in the circumferential direction; In fact, the smaller groove width s is more economical, so that you-! 15, the contacting of the radial surface portions and also the contact between the peripheral portions of the surface portions 13 and 14 according to the invention occurs with approximately the same deformation a.

Fig. 4c shows the change caused by the invention in the curve of the lamella bending spring 20. Progression is stronger than prior art.

It follows that, with the maximum tangential force at Ftan.max::: V, the end faces 16 of the lamellae (see Figure 4b) are positioned less forcefully * * 25 than in the prior art, which in particular shortens braking distance on wet road surfaces, , such as when driving on snowy roads, the chamfer angle α of the end faces 16 of the fins will not be reduced, but the grip will remain within this range.

A person skilled in the art can very precisely determine the curve of a bending spring for the conditions of use of the particular tire: increasing the wave amplitude A (see Figure 3) increases the stiffening effect of the invention from the contact of the surface portions 14 and 15 (see Figures 4a and 4b). Furthermore, the stiffening effect 9 106784 is approximately proportional to the sine of the angle between the beam and the ridge of the waves and the bottoms, respectively, i.e. it can be increased by increasing the angle β. The shortening of the wavelength λ (see Figure 3) allows the effect to appear with a smaller deformation, but it does not increase until 5 min. Reducing the groove width s allows the effect to appear gradually with a smaller deformation, but it has a greater effect on increasing the stiffness with a larger deformation.

By means of the wavelength λ, the amplitude A, and the radius of curvature of the ridges of the waves and the bottoms 10 respectively, the ramp, i.e. the bevelling of the groove surfaces, is perpendicular to the "propagation direction" of the waves; it can be steeper the narrower the groove width s. As a result, the groove width s is preferably selected to be smaller than usual, namely about 0.4 mm for passenger car winter tires.

Increasing the angle P, i.e. increasing the chamfering of the wave ridges and soles of the invention to a radius of 6 greater than 70 °, does not substantially increase the effect, but instead increases the extreme loads, especially on dry road near the boundary and at deep grooves. 20 risk of friction loss. As a result, a bevel between 30 ° and 50 ° is preferred.

. The invention alleviates the cost without increasing the discrepancy between the good traction properties required on snow on the one hand and the good braking characteristics required on wet roads and is particularly suited to winter tires with a chassis.

Claims (5)

Vehicle ring (1), the wear surface (2) of which at least has at one axial edge portion (L, R) seen from above, substantially axially extending grooves (3), which are arranged in the shape of a cradle, such that the guard peaks (4) and the valleys (5) are substantially straight, which straight extend obliquely in the transverse plane, characterized in that the inclined position of the road peaks (4) and the valleys (5) is so directed that along the road peaks (4) or cradle valleys (3) (5) in the transverse plane, when displaced radially from inside to radially outward, you end up axially inert. 10 Vehicle ring (1) according to Claim 1, characterized in that the top pair (4) and troughs (5) of the cradle in the transverse plane relative to the radius (6) form an angle (β) which is between 20 ° - 70 ° , preferably between 30 ° - 50 ° 1 Vehicle ring (1) according to claim 1, characterized in that the width (s) of the joints (3) in a manner known per se is between 0.3 mm -1.0 mm. Vehicle ring according to any one of claims 1 to 3, characterized in that also the cutters (3) arranged within the axially innermost region (M) have been formed according to the method according to the invention. 5. The cutting board (7), which is fixed in a vulcanization form, characterized in that the inclination (β) of the peaks (4) and the valleys (5) of the road to the attachment edge (18) is between 20 ° - 70 ° , wherein the oblique guard peaks (4) and • · w: v. The valleys (5) are so directed that in a transverse plane displacement radially from within. along the road tops (4) or valleys (5) of the cutting board (7), axial mesh is reached. ···