Vehicle pneumatic tire

Abstract

The invention relates to a vehicle pneumatic tire having a tread with raised tread elements (1) having 3D cuts (4) extending in plan view parallel to one another and at an angle of 0° to 50° to the axial direction, with a width (b1) of 0.4 mm to 1.2 mm and a maximum depth (t1) of 70% to 100% of the tread depth, each having an intermediate cut section (4a) extending in plan view in a wave shape, with an amplitude (A) and a wavelength (λ) and a wave cut region (7) extending from the tread circumference into the cut (4); the wave cut region (7) is connected to three wave sections (4a', 4a") of the intermediate cut section (4a) which follow one another in plan view, each to a half wavelength (λ / 2), and, viewed from one of the cut walls (5), consists of an outer region range (7") which is U-shaped, with a half wavelength (λ / 2) extending between two outer wave sections (4a"), and an inner region range (7') which is connected to the intermediate wave section (4a') and is curved opposite the outer region range (7"), surrounded by the outer region range, wherein the amplitude of the wave-shaped cut section (4a) decreases in the inner region range (7') in the radial direction from the tread circumference.

Description

TECHNICAL FIELD

[0001] The invention relates to a vehicle pneumatic tire having a tread with raised tread elements, which raised tread elements have incisions extending parallel to one another in plan view and at an angle of 0° to 50° with respect to the axial direction, with a width of 0.4 mm to 1.2 mm and a maximum depth of 70% to 100% of the tread depth, which incisions each have an intermediate incision section extending in plan view in a wave shape, with an amplitude and a wavelength, and at least one wavy incision region, which extends into the incision from the tread circumference. BACKGROUND

[0002] Such a vehicle pneumatic tire is known, for example, from WO 2013 / 064300 A1. The tread of the tire has raised tread elements with incisions, which incisions each consist of an intermediate incision section extending in plan view in a harmonic form and two edge-side incision sections extending linearly and aligned with one another. The intermediate incision section has a wavy incision region, which extends into the incision, in which wavy incision region the wavelength increases or decreases radially inwardly from the tread circumference. The amplitude remains constant over the depth profile of the incision. The incisions thus implemented influence the stiffness of the raised tread elements, thereby enabling improved driving performance on dry roads. In addition, lateral guidance losses on winter roads are offset when the tire is new or worn.

[0003] Furthermore, a vehicle pneumatic tire having a tread with tread blocks in which incisions are designed which extend parallel to one another and in plan view in a harmonic form, which incisions have a wavy incision region extending into the incision, is known from US 4 598 747 A. According to one variant, the amplitude of the incisions extending in a wave shape decreases in the wavy incision region radially inwardly from the outer surface of the respective tread block in a linear, i.e. uniform, manner. Preferably, the amplitude of the incision section extending in a wave shape is constant in the wavy incision region in the range of the radially outer region and decreases only in the range of the radially inner region.

[0004] In plan view, incisions extending at least locally in a wave shape or in a zigzag shape are advantageous in terms of the lateral stiffness of the raised tread elements, since the raised tread element segments composed of such incisions are able to support one another in the axial direction, in particular when subjected to a load. In this regard, the incisions known hitherto are not optimal in terms of the stiffness of the raised tread elements changing with tread wear and the bending behavior of the raised tread element segments in connection therewith, since these incisions can cause uneven wear. SUMMARY

[0005] It is therefore a basic object of the invention to avoid uneven wear in a vehicle pneumatic tire of the type mentioned in the opening paragraph.

[0006] The object set is achieved according to the application in that the wavy cut region is connected to three wave segments of the intermediate cut segment which follow one another in plan view, each reaching half a wavelength, and in that the wavy cut region, viewed from one of the cut walls, consists of an outer region range which, keeping half a wavelength, extends in a U shape between the two outer wave segments, and an inner region range which, surrounded by the outer region range, is connected to the intermediate wave segment and is curved opposite the outer region range, wherein the amplitude of the wave- extending cut segment decreases in the inner region range in the radial direction from the tread circumference.

[0007] Due to the specific wavy cut region, the cut has a clear "wavy shape" in the new or little-worn tread, whereby the cut walls can support one another very well in the transverse direction in the case of loading. Since the amplitude decreases in the inner region range in the direction towards the cut bottom, the support effect decreases with the gradual wear of the tread, whereas a support effect acting in the circumferential direction can be produced more. By these measures, the stiffness of the raised block and the bending behavior associated therewith are influenced, so that the wear is significantly equalized. Here, the good properties of the tire are maintained in winter driving conditions, in particular on ice and snow.

[0008] According to one preferred embodiment, the amplitude of the wave- extending cut segment decreases in the inner region range in the radial direction from the tread circumference in a progressive manner. This is most advantageous in terms of the bending and wear behavior of the raised block, since the stiffness of the raised block increases disproportionately with the gradual increase in wear.

[0009] When the wavy cut region ends at a spacing of 1.5 mm measured in the radial direction from the cut bottom to the cut bottom, the cut can be formed particularly reliably in the raised blocks of the tread during tire vulcanization with high quality. This embodiment is also advantageous for the described advantageous effects of the cut.

[0010] A further preferred embodiment is characterized in that, viewed in a cross section oriented perpendicular to the cut median plane and extending through the maximum deflection position of the inner region range, the depth at which a reference plane extending centrally through the wavy cut region intersects the cut median plane oriented in the direction of extent of the wave- extending cut segment is 45% to 70%, in particular up to 60%, of the maximum depth of the cut. By this design, the inner region range is correspondingly limited in the depth at which it ends. In the wear state of the tread associated with this depth range, the increased support effect acting in the circumferential direction mentioned is produced, for which the now almost no longer pronounced wavy shape of the cut is advantageous.

[0011] In another preferred embodiment, the incisions each have a unique undulating incision region. In this embodiment, it is advantageous for the described support effect that the intermediate incision section has a length measured in the tread periphery along the incision midplane which is 45% to 65%, in particular 50% to 55%, of the extension length of the incision measured in the same way.

[0012] It is also advantageous for the support effect that the intermediate incision section has an amplitude on the tread periphery which is 100% to 200%, in particular 130% to 160%, of the width of the incision.

[0013] It is furthermore advantageous in this regard that the intermediate incision section has an amplitude on the tread periphery which is 10% to 25%, in particular 15% to 20%, of the wavelength of the intermediate incision section on the tread periphery.

[0014] The incisions in particular have incision walls which, outside the undulating incision region(s), are formed by a flat surface.

[0015] According to another preferred embodiment, the incisions have two edge-side incision sections which are connected to the intermediate incision section, extend in plan view straight and aligned with one another, the depth of the edge-side incision sections in particular being 20% to 70% of the maximum depth. The edge-side incision sections contribute to the homogenization of the tread wear.

[0016] It is also advantageous in this regard that the incisions cross the protruding tread blocks. BRIEF DESCRIPTION OF DRAWINGS

[0017] Further features, advantages and details of the application will now be described in detail with the aid of the attached drawings, which show an embodiment of the application by way of example. In the drawings:

[0018] Figure 1 A view of several tread blocks of a tread of a vehicle pneumatic tire is shown,

[0019] Figure 2 An enlarged visualization of an incision according to an implementation variant of the application is shown,

[0020] Figure 3 A view of the incision of Figure 2 is shown, which is surrounded by rubber material,

[0021] Figure 4 A view similar to Figure 3 is shown, in which the tread blocks are worn to the level of the line IV-IV of Figure 2 ,

[0022] Figure 5 Another view similar to Figure 3 is shown, in which the tread blocks are worn to the level of the line V-V of Figure 2horizontal of the line V-V,

[0023] Figure 6 shows a cross section through the cut according to Figure 3 the line VI-VI through the cut, and

[0024] Figure 7 shows a cross section through the cut according to Figure 3 the line VII-VII through the cut.

[0025] List of reference signs

[0026] 1...........sipe

[0027] 2...........circumferential groove

[0028] 3...........transverse groove

[0029] 4...........cut

[0030] 4a..........intermediate cut section

[0031] 4a'.........intermediate wavy section

[0032] 4a"........outer wavy section

[0033] 4b..........edge-side cut section

[0034] 5...........cut wall

[0035] 5a..........curved wall section

[0036] 5b..........flat surface

[0037] 6...........cut bottom

[0038] 7...........wavy cut region

[0039] 7'..........inner region range

[0040] 7".........outer region range

[0041] a1..........pitch

[0042] A...........amplitude

[0043] b1..........width

[0044] E M.......... middle plane of the cut

[0045] F........... reference surface

[0046] l a .......... length

[0047] t1.......... maximum depth

[0048] t2.......... depth

[0049] U........... double arrow (circumferential direction)

[0050] λ.......... wavelength DETAILED DESCRIPTION

[0051] The vehicle pneumatic tire embodied according to the invention is in particular a tire of the radial design for use in passenger vehicles, trucks or light trucks, wherein the vehicle pneumatic tire is particularly well suited for driving in winter road conditions.

[0052] Figure 1 Four blocks 1 are shown, which belong to two block rows running alongside one another in the middle of the tread area, which are separated from one another by circumferential grooves 2 running straight in the embodiment shown, wherein further unmarked circumferential grooves delimit the block rows on the outside. The double arrow U designates the circumferential direction of the tire.

[0053] The circumferential grooves 2 have a block depth set for the respective vehicle pneumatic tire, which is in particular 6.5 mm to 10.0 mm. Inside the block rows, the blocks 1 adjacent in the circumferential direction are separated from one another by transverse grooves 3, which in the embodiment shown have the same depth as the circumferential grooves 2.

[0054] In the embodiment shown, each block 1 is provided with two cuts 4 embodied identically, which are arranged uniformly inside each block 1, parallel to one another and running in the transverse direction and across the respective block 1. Further design options for the cuts 4 will be set out below on the basis of individual cuts 4.

[0055] As Figures 2 to 7 is shown, the cut 4 is delimited by two corresponding cut walls 5 and a cut bottom 6 (see in particular Figure 2 ), has a constant width b1 Figure 3 , Figure 7 of 0.4 mm to 1.2 mm, in particular to 0.8 mm, and has a maximum depth t1 Figure 6 in the radial direction of 70% to 100%, in particular up to 95%, of the block depth.

[0056] like Figure 3 As shown, in a top view and viewed in the tire's brand-new condition, cut 4 consists of a central cut section 4a extending in a harmonic form, and two edge side cut sections 4b extending in a straight line and aligned with each other in the top view. Cut 4 has a central plane E oriented in the direction of harmonic propagation of the central cut section 4a in the top view and extending through the center of the edge side cut sections 4b. M The depth reached by the edge-side incision segment 4b is preferably 20% to 70% of the maximum depth t1 mentioned for the incision 4. Figure 2 , Figure 6 The intermediate cut section 4a has the maximum mentioned depth t1 over its entire extension. Figure 2 ) and along the middle plane E of the cut around the tread M The measured length l a This length is 45% to 65%, particularly 50% to 55%, of the extension length of the cut 4, measured in a similar manner. Preferably, the length of the intermediate cut segment 4a is l a The edge side cut sections 4b are selected such that each has a length similar to l. a The length measured on the ground is at least 3.0 mm.

[0057] according to Figure 2 The intermediate cut section 4a has a wavy cut area 7 extending radially inward from the periphery of the tread, which terminates at a distance a1.5 mm from the bottom of the cut 6, measured radially. The cut area 7 is formed or defined by two oppositely designed, specially curved wall sections 5a of the cut wall 5. In the outer region of the curved wall section 5a, the cut wall 5 is a flat surface 5b. The curved wall section 5a defines a protrusion relative to the flat surface 5b and a recess opposite to the protrusion on each cut wall 5, wherein the protrusion and recess... Figure 2 Unnumbered. In the illustrated embodiment, the curved wall segments 5a are designed such that they have no bends and have transition curves corresponding to the flat surface 5b.

[0058] like Figure 3 As shown, in the top view, the wave based on the intermediate cut section 4a has an amplitude A and a wavelength λ, where the wavelength λ and amplitude A are relative to the wave extending through the wavy cut region 7. Figure 3 The reference plane F, indicated by the dashed line, is used for measurement. In the case of reference plane F, the curvature provided at the transition from the intermediate cut section 4a to the edge-side cut section 4b in the embodiment is not considered. The amplitude A and wavelength λ of the intermediate cut section 4a mentioned below refer to the wave on which it is based.

[0059] Since the intermediate cut section 4a extends in the form of a harmonic on the tread circumference as mentioned, the wavelength λ and the amplitude A on the tread circumference are constant, wherein the amplitude A on the tread circumference is 100% to 200%, in particular 130% to 160%, of the width b1 of the cut 4 and / or the wavelength λ measured on the tread circumference is 10% to 25%, in particular 15% to 20%. The intermediate cut section 4a extends over 1.5 wavelengths λ on the tread circumference and consists in a top view of an intermediate wave section 4a' extending over half a wavelength λ / 2 and two outer wave sections 4a" each extending over half a wavelength λ / 2.

[0060] As Figure 2 is shown, the wavy cut region 7 consists of a U-shaped outer region extent 7" and an inner region extent 7' surrounded thereby, as viewed from one of the cut walls 5. The outer region extent 7" extends between the two outer wave sections 4a" while maintaining half a wavelength λ / 2 and surrounds the inner region extent 7', which is curved opposite to the outer region extent 7" and is connected to the intermediate wave section 4a' (see also Figure 3 ). Corresponding to the described design, the inner region extent 7' is located on one side of the cut middle plane E M , while the outer region extent 7" is located on the other side of the cut middle plane E M ( Figure 3 ).

[0061] As Figure 3 is shown in combination with Figure 6 , the amplitude A of the intermediate cut section 4a decreases in a progressive (accelerating) manner in the radial direction from the tread circumference towards the direction of the cut bottom 6 in the inner region extent 7', as viewed in a cross section perpendicular to the cut middle plane E M ( M Figure 6 ). Correspondingly, the amplitude in the inner region extent 7' decreases only slightly at first from the tread circumference and decreases in an accelerating, i.e. steep, manner with increasing depth, so that the inner region extent 7' is continuously curved as viewed in a cross section perpendicular to the cut middle plane E M ( M M Figure 6 ). As viewed in a cross section oriented perpendicular to the cut middle plane E M and extending through the maximum deflection (amplitude), the depth t2 at which the reference face F intersects the cut middle plane E M is 45% to 70%, in particular up to 60%, of the maximum depth t1 of the cut 4 ( Figure 6 ). In the shown embodiment, the amplitude A of the intermediate cut section 4a is constant in the outer region extent 7" ( Figure 7Alternatively, the amplitude A in the outer region extent 7" can decrease in the radial direction.

[0062] The application is not limited to the described embodiments.

[0063] The intermediate cutout section can extend over more than 1.5 wavelengths λ, i.e. more than three times, in particular up to seven times, and can have a corresponding intermediate wave section extending over half a wavelength λ / 2. As described in connection with the embodiments, the wave cutout region is connected to three wave sections of the intermediate cutout section extending over half a wavelength λ / 2, which are consecutive to one another in a top view. In the case of a longer implementation of the intermediate cutout section, the cutouts can each have a plurality of, in particular two, wave cutout regions formed side by side. The wave sections of the intermediate cutout section, which are not connected to a wave cutout region, can be implemented in a known manner.

[0064] The cutouts can be formed in any lug, thus, for example, also in a circumferentially encircling tread rib. Furthermore, the cutouts can end on one or both sides within the lug, so that these cutouts do not cross the lug. The cutouts extend at least in groups and in particular at least parallel to one another within the respective lug and at an angle of 0° to 50° to the axial direction, wherein the angle respectively relates to the cutout middle plane E M The edge-side cutout section can have the same depth as the intermediate cutout section.

Claims

1. A vehicle pneumatic tire having a tread having a raised tread pattern (1) having cuts (4) parallel to each other in a top view and extending at an angle of 0° to 50° with respect to the axial direction, each cut having a width (b1) of 0.4 mm to 1.2 mm and a maximum depth (t1) of 70% to 100% of the tread depth, each cut having a wavy intermediate cut section (4a) extending in a top view, the intermediate cut section having an amplitude (A) and a wavelength (λ) and a wavy cut region (7) extending from the periphery of the tread into the cut (4), wherein each cut (4) has a unique wavy cut region (7). Its features are, The wavy cut region (7) is connected to three wave segments (4a', 4a”) of the intermediate cut section (4a) that are sequentially connected in the top view and each reach half a wavelength (λ / 2). When viewed from one of the cut walls of the cut wall (5), the wavy cut region consists of a U-shaped outer region (7”) that extends between the two outer wave segments (4a”) while maintaining half a wavelength (λ / 2), and an inner region (7’) that is surrounded by the outer region, connected to the intermediate wave segment (4a'), and curved in the opposite direction to the outer region (7”). The amplitude of the wave-extending intermediate cut section (4a) decreases gradually in the radial direction from the tread periphery in the inner region (7’).

2. The vehicle pneumatic tire according to claim 1, characterized in that, The wavy cut area (7) terminates at a distance (a1) from the bottom of the cut (6) to 1.5 mm, measured in the radial direction.

3. The vehicle pneumatic tire according to claim 1, characterized in that, Within the said internal region (7'), in the plane perpendicular to the cut center plane (E) M ) Observed in a cross section oriented and extending through the maximum deflection position of the inner region (7'), the reference plane (F) extending centrally through the wavy cut region (7) and the cut mid-plane (E) oriented along the extension direction of the intermediate cut segment (4a) extending along the waveform. M The depth (t2) of the intersection is 45% to 70% of the maximum depth (t1) of the cut (4).

4. The vehicle pneumatic tire according to claim 1, characterized in that, Within the said internal region (7'), in the plane perpendicular to the cut center plane (E) M ) Observed in a cross section oriented and extending through the maximum deflection position of the inner region (7'), the reference plane (F) extending centrally through the wavy cut region (7) and the cut mid-plane (E) oriented along the extension direction of the intermediate cut segment (4a) extending along the waveform. M The depth (t2) of the intersection is 45% to 60% of the maximum depth (t1) of the cut (4).

5. The vehicle pneumatic tire according to claim 1, characterized in that, The wavy sections (4a', 4a'") of the intermediate cut section (4a) connected to the wavy cut area (7) have a wavy section (4a', 4a'') along the cut center plane (E) on the periphery of the tread. M ) Measured length (l a The length is 45% to 65% of the extension length of the cut (4) measured in the same manner.

6. The vehicle pneumatic tire according to claim 1, characterized in that, The wavy sections (4a', 4a'") of the intermediate cut section (4a) connected to the wavy cut area (7) have a wavy section (4a', 4a'') along the cut center plane (E) on the periphery of the tread. M ) Measured length (l a The length is 50% to 55% of the extension length of the cut (4) measured in the same manner.

7. The vehicle pneumatic tire according to claim 1, characterized in that, The amplitude (A) of the intermediate cut section (4a) on the periphery of the tread is 100% to 200% of the width (b1) of the cut (4).

8. The vehicle pneumatic tire according to claim 1, characterized in that, The amplitude (A) of the intermediate cut section (4a) on the periphery of the tread is 130% to 160% of the width (b1) of the cut (4).

9. The vehicle pneumatic tire according to claim 1, characterized in that, The amplitude (A) of the intermediate cut section (4a) on the periphery of the tread is 10% to 25% of the wavelength (λ) of the intermediate cut section (4a) on the periphery of the tread.

10. The vehicle pneumatic tire according to claim 1, characterized in that, The amplitude (A) of the intermediate cut section (4a) on the periphery of the tread is 15% to 20% of the wavelength (λ) of the intermediate cut section (4a) on the periphery of the tread.

11. The vehicle pneumatic tire according to claim 1, characterized in that, The cut (4) has a cut wall (5) which is formed by a flat surface outside the wavy cut area (7).

12. The vehicle pneumatic tire according to claim 3, characterized in that, The cut (4) has two edge side cut sections (4b) that are connected to the intermediate cut section (4a) and extend in a straight line and aligned with each other in the top view, the depth of the edge side cut sections being 20% ​​to 70% of the maximum depth (t1).

13. The vehicle pneumatic tire according to claim 1, characterized in that, The cut (4) traverses the convex tire tread (1).

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