Molding pin, vulcanizing device and pneumatic vehicle tire

Abstract

The invention relates to a molding pin (15) for a vulcanization segment (18) of a vulcanization device (19) for forming a stud hole in a tread of a pneumatic vehicle tire, the molding pin (15) comprising: - a fixing section (16) for fixing the mold pin (15) in the vulcanization segment (18); - a main mold section (20), wherein the main mold section (20) adjoins the fixing section (16) in the longitudinal direction (X); and - a foot mold section (22) which adjoins the main mold section (20) in the longitudinal direction (X) and which is widened in a radial direction (R) relative to the main mold section (20) for forming a foot section (12) in the stud hole (3) during the manufacture of the pneumatic vehicle tire (1). According to the invention, at least one elevation (21) extending annularly around the forming pin (15) is arranged on an outer wall (23) of the forming pin (15), which elevation differs from the radially widened foot forming section (22) of the forming pin (15), for forming at least one expansion point extending annularly in an inner wall of the spike hole during the manufacture of the pneumatic vehicle tire.

Description

The invention relates to a mold pin according to the preamble of claim 1, a vulcanization device and a pneumatic vehicle tire, in particular produced by means of such a vulcanization device.Spike tires, i.e. pneumatic vehicle tires with spikes arranged on the circumferential side, usually have spikes which are manufactured from metal. For this purpose, a spike body of the respective spike normally consists of steel or aluminum, and a pin of the spike, which is accommodated or embedded in the spike body and projects from the latter on the upper side, is normally produced from a hard metal or steel. A harder material is selected for the pin than for the spike body, since the pin penetrates into the ice on the roadway and the forces are transmitted via the latter. The spike body, on the other hand, should be wear-resistant in order to support the pin over the entire service life of the pneumatic vehicle tire.Pneumatic vehicle tires having preformed stud holes for installation of the studs are normally manufactured in a curing apparatus. The vulcanization device has mold pins (mold pins) which project perpendicularly from the individual vulcanization elements and whose shape is then depicted in the tread of the pneumatic vehicle tire. The shape of these spike holes or of the shaped pins is often based on the shape of the spikes, but it is also possible for only simple cylindrical holes or shaped pins to be used. In order to fix the spike securely in the spike hole, the spike hole is generally smaller or narrower than the spike, with the result that the spike is seated under stress in the spike hole. By way of example, such a shaped pin and the spike hole resulting therefrom are described in EP 2 641 754 B1, wherein provision is additionally made therein for a groove to extend in the depth direction of the spike hole or for at least one elevation to extend in the longitudinal direction of the shaped pin in order to prevent the inserted spike from being rotated.When installing the stud in such a stud hole, the rubber of the tire matrix is very greatly expanded to make room for the larger studs. However, the tire matrix does not always expand sufficiently to enclose the stud over its full circumference or over its entire longitudinal extent. This creates cavities, in particular in a waisted region of the stud, in which the stud narrows before it merges into a foot flange, and / or a surface of the pneumatic vehicle tire is constricted downward in the direction of the stud hole bottom. If the studs are chemically bonded to the rubber of the tire matrix by means of an adhesion promoter and a thermal activation, the heating tire matrix expands, which initially results in an improvement in the chemical bonding, and enters into a cohesive or chemical contact with a surface of the stud. During this relaxation, however, the radially constricted surface of the pneumatic vehicle tire rises in the immediate vicinity of the stud, so that a previously set stud protrusion, with which a pin of the stud protrudes with its free end from the tread, changes. Furthermore, regardless of the shape of the stud, other types of slow creep processes can also occur in the rubber of the tire matrix, as a result of which the stud protrusion changes slowly.The process of introducing the spike is made more difficult because this subsequent movement of the spike, which can lead to a changed spike protrusion, is to be scheduled. Since the spike protrusion is a quality feature of a pneumatic vehicle tire, which is also used when checking regulations, it should be adjustable as accurately and in a controlled manner as possible.The object of the present invention is therefore to provide a mold pin, a vulcanization device and a pneumatic vehicle tire in which or with which the described disadvantages are avoided or minimized, in particular an improved installation situation of the spike in the rubber of the tire matrix results.This object is achieved by a mold pin, a vulcanization device and a pneumatic vehicle tire according to the independent claims. The dependent claims indicate preferred refinements.Accordingly, a mold pin for a vulcanization segment of a vulcanization device for forming a spike hole is provided in a tread of a pneumatic vehicle tire, the mold pin comprising:a fixing portion for fixing the mold pin in the vulcanization segment;a main mold section, wherein the main mold section adjoins the fixing section in the longitudinal direction, wherein the main mold section can be conical and / or cylindrical, for example; anda foot molding portion which is longitudinally continuous to the main molding portion and which is expanded from the main molding portion in a radial direction to form a foot portion in the stud hole in the manufacture of the pneumatic vehicle tire.According to the invention, at least one elevation which extends annularly around the mold pin and differs from the radially widened foot-shaped portion of the mold pin is arranged on an outer wall of the mold pin in order to form at least one expansion point which extends annularly in an inner wall of the spike hole during the production of the pneumatic vehicle tyre.According to the invention, a vulcanization device having a plurality of vulcanization segments arranged in a circle for producing a pneumatic vehicle tire is also provided, wherein a respective fixing section of a mold pin according to the invention is accommodated in receptacles in the respective vulcanization segment.Furthermore, a pneumatic vehicle tire corresponding to the mold pins, having a tread and spike holes arranged in the tread, is also provided, which is produced in particular in a vulcanization device according to the invention having the mold pins according to the invention, wherein a spike can be introduced into the spike holes in each case, wherein the spike holes each have:a main portion, wherein the main portion protrudes from a surface of the running surface, for example via an additional frustoconical mouth region, into the running surface in a depth direction, for receiving a main flange of the spike; anda foot portion which adjoins the main portion in the depth direction and which is widened in a radial direction with respect to the main portion for receiving a foot flange of the spike and for mechanically anchoring the spike in the spike hole.According to the invention, at least one groove extending annularly around the spike hole is introduced into an inner wall of the spike hole, said groove differing from the radially widened foot section of the spike hole, for forming at least one expansion point in the spike hole.The at least one elevation in the mold pin, which has, for example, a curved or convex cross section, advantageously ensures that, in the pneumatic vehicle tire, at least one additional groove, which has, for example, a curved or concave cross section, is formed as a point of expansion in the stud hole during vulcanization. The respective groove then has the effect that, during the installation or during the pressing of a spike into the spike hole, the rubber of the tire matrix can expand further in addition to the normal expansion, so that the spike hole surface can additionally extend in the depth direction. Stretching of the rubber in the region of the spike hole occurs since the spike to be mounted is larger than the associated spike hole in order to enable a firm fit and good mechanical anchoring.Due to the additional extensibility of the rubber material, a constriction or a crowning of the surface of the tread in the depth direction with respect to the spike hole toward the spike hole bottom is suppressed or prevented. This leads to an improvement in the contact between the pressed-in spike and the rubber material of the running surface, since the formation of air inclusions or cavities is prevented, in particular in the case of a spike which has a waisted region.Therefore, the installation situation of the spike in the rubber material of the tread is significantly improved, whereby relaxation and creep movements which lead to a change in the spike protrusion are also reduced. As a result, the compliance of a sensed pneumatic vehicle tire can be complied with more reliably.Overall, therefore, an improvement in the accuracy of the marking and of the marking image is advantageously achieved, and also to avoid or minimize a subsequent change in the spike protrusion. Thus, for example, in the case of an activation of an adhesion promoter by heating the pneumatic vehicle tire, the desired spike protrusion can already be set beforehand, since a subsequent uncertain change in the spike protrusion due to relaxation processes generally no longer occurs or occurs only to a slight extent on account of the strain point according to the invention and therefore no longer has to be compensated.It is preferably furthermore provided that the at least one elevation has an elevation width of between 0.1 mm and 1 mm and / or an elevation height of between 0.5 mm and 3 mm. Accordingly, the at least one groove then has a groove width of between 0.1 mm and 1 mm and / or a groove height of between 0.5 mm and 3 mm. The elevation is thus much smaller or narrower in width than, for example, the foot-shaped portion of the shaped pin which serves for forming the foot portion in the spike hole for the mechanical anchoring of the spike. In order to increase the extensibility or for the additional elongation of the surface of the spike hole to be achieved, this elevation width is already sufficient for forming a groove having a corresponding groove width.It is preferably furthermore provided that the at least one elevation is arranged in the main shaped portion of the shaped pin, wherein the outer wall of the spike hole widens in the radial direction in the region of the main shaped portion in order to form the elevation. Accordingly, it is preferably provided that the at least one formed groove is arranged in the main section of the spike hole, wherein the inner wall of the respective spike hole widens in the radial direction in the region of the main section in order to form the groove. In this way, the groove can be formed as an expansion point adjacent to a waisted region of a pressed-in spike which lies radially adjacent to the main section, so that the formation of hollow spaces or air inclusions, which preferably form adjacent to such waisted regions of the spike, can be avoided by the additional extensibility of the surface of the spike hole in precisely this region.It is preferably further provided that the at least one elevation is located in an upper half of the forming pin adjoining the fixing section or in a lower half of the forming pin or that the at least one groove is located in an upper half of the spike hole adjoining the surface of the running surface or in a lower half of the spike hole. In this way, a flexible adaptation to the shape of the spike to be mounted is possible. The elevation can thus be positioned on the mold pin in such a way that a groove is formed in the spike hole in a region which is located above or below the waisted region of a pressed-in spike.Furthermore, it is also possible for the at least one elevation to be arranged in the foot shaped portion, wherein the at least one elevation protrudes from the outer wall of the shaped pin in the region of the foot shaped portion, preferably protrudes perpendicularly. Accordingly, it is preferably provided that the at least one groove is arranged in the foot section, wherein the at least one groove protrudes from the inner wall of the spike hole in the region of the foot section), preferably protrudes perpendicularly. It is therefore also possible for the additional extensibility to be provided in the foot section, which is generally adjacent or just below the waisted region of a pressed-in spike. In this way, too, the expansion point has a positive effect on the installation situation of the spike.Preferably, it can also be provided that two elevations spaced apart from one another in the longitudinal direction are provided on the mold pin, for example an elevation in the foot mold section and an elevation in the main mold section. This results in two grooves spaced apart from each other in the depth direction being formed in the spike hole. In this way, an additional extensibility can be achieved at different points, which leads to a further optimization of the installation situation depending on the shape of the spike.In the drawings, there are shown: FIG. 1 shows a detail of a tread of a pneumatic vehicle tire having a spike; FIG. 2 shows a spike according to FIG. 1 ; FIG. 3 shows a spike hole for receiving the spike according to FIG. 2 ; FIGS. 4A, 4B, 4C show different embodiments of the spike hole in a position opposite the spike according to FIG. 2 ; and FIG. 5 shows a mold pin for inserting one of the spike holes according to FIGS. 4A, 4B, 4C into a pneumatic vehicle tire.FIG. 1 schematically shows a section of a pneumatic vehicle tire 1, in particular a pneumatic vehicle tire, which rolls on a subgrade U and which has a plurality of spikes 2 distributed over its circumference. A spike 2 is understood here to mean a type of pin or bolt which, as illustrated, is inserted into the profiled tread 1 aof the pneumatic vehicle tire 1 and is anchored therein. For this purpose, during the production of the pneumatic vehicle tire 1, a plurality of spike holes 3 are introduced in the tread 1 ain a known manner, into which the respective spike 2 is mechanically pressed. Optionally, the pneumatic vehicle tire 1 and the pressed-in stud 2 can subsequently be joined to one another chemically or in a materially bonded manner by means of an adhesion promoter 4, wherein the stud 2 is coated with the adhesion promoter 4 before being pressed into the respective stud hole 3. After the spike 2 has been pressed into the respective spike hole 3, the adhesion promoter 4 is activated by a targeted heat treatment in order to form the chemical compound.As shown in a detailed view in FIG. 2, each spike 2 has a pin 5 which extends in the longitudinal direction X with respect to the spike 2 and which projects or projects with its free end 5 a, in the state pressed into the respective spike hole 3, from the running surface 1 aby a spike protrusion A. The pin 5 is accommodated with its end opposite the free end 5 ain a main flange 6, which extends further downward in the longitudinal direction X or, extending away from the free end 5 aof the pin 5, merges via a waisted region 7 into a foot flange 8. The foot flange 8 is designed in the manner of a plate or disk and serves for the mechanical anchoring of the spike 3 in the spike hole 3.According to FIG. 3, the spike hole 3 is illustrated in more detail, wherein the spike hole 3 extends, starting from a surface 1 bof the running surface 1 a, via a step 13 in a main portion 10 downwards away from the surface 1 bin the depth direction T, preferably cylindrically (see FIG. 3 ) or conically (not illustrated). Starting from the step 13 in the surface 1 b, the main section 10 can also have a frustoconical mouth region 10 awhich forms the transition between the surface 1 bof the running surface 1 aor the step 13 and the cylindrical or conical main section 10 of the spike hole 3.In the main section 10, a groove 11 is introduced annularly circumferentially into an inner wall 14 of the spike hole 3 at a defined extension depth T 1 (measured from the surface 1 bbefore the step 13). The groove 11 has a groove width R 11 (extension in the radial direction R with respect to the spike hole 3) of, for example, between 0.1 mm and 1 mm and a groove height T 11 (extension in the depth direction T of the spike hole 3) of, for example, between 0.5 mm and 3 mm. Within the groove 11, the inner wall 14 is therefore widened radially outwards (away from a longitudinal central axis L of the spike hole 3) over a range of between 0.5 mm and 3 mm by between 0.1 mm and 1 mm at the expansion depth T 1. All dimensions of components of the pneumatic vehicle tire 1 mentioned hitherto or below relate here to the state after vulcanization and before demolding, wherein the pneumatic vehicle tire 1 generally shrinks even slightly after demolding. The groove 11 preferably has a curved or concave cross section. However, notched or polygonal cross-sections can also be provided. The groove 11 serves as a point of expansion D, as explained below.Below the main section 10, the spike hole 3 merges into a foot section 12, wherein the foot section 12 is widened radially outwards with respect to the main section 10, for example in the form of a disk. The foot section 12 has a first radial extension r 1 (starting from the longitudinal central axis L of the spike hole 3), which corresponds to at least 1.5 times, preferably at least twice, a second radial extension r 2 of the main section 10. For example, the first radial extent r1may be between 1.5 mm and 3 mm and the second radial extent r2may be between 0.75 mm and 1.5 mm. The foot section 12 thus also protrudes significantly deeper into the running surface 1 ain the radial direction R than the groove 11 with the radial groove width R 11 let into the inner wall 14 of the spike hole 3. Accordingly, r1>>r2+R11applies.This increased first radial extension r1 of the foot section 12 serves to receive the foot flange 8 of the spike 2 in the pressed-in state, for mechanically anchoring the spike 2 in the spike hole 3.In FIGS. 4A, 4B, 4C, the spike 2 and the respective spike hole 3 are shown next to one another for comparison in different embodiments:According to FIG. 4A, the groove 11 in the main section 10 can adjoin the waisted region 7 for example in the radial direction R, i.e. the waisted region 7 lies at least in regions at the extension depth T 1. The expansion depth T 1 is then preferably in a lower half uH 3 of the spike hole 3. Alternatively, as illustrated in FIG. 4B, the waisted region 7 can be below the expansion depth T 1, i.e. the expansion depth T 1 or the groove 11 are higher than in FIG. 4A, in particular in an upper half oH 3 of the spike hole 3. The expansion depth T 1 with the groove 11 is then located in the radial direction R adjacent to a transition 9, which runs, for example, conically and runs between an upper region 6 a(for example, embodied cylindrically) of the main flange 6 of the spike 2 and the waisted region 7.According to a further alternative, it can also be provided that the expansion point D is located in the foot section 12 of the spike hole 3, as indicated by dashed lines in FIG. 3 and is illustrated in the opposite position to the spike 2 in FIG. 4C. Accordingly, the groove 11 with the groove height T 11 projects annularly circumferentially around the groove width R 11 from the inner wall 14 of the spike hole 3 in the region of the base portion 12 of the spike hole 3, for example perpendicularly. The extension depth T 1 is accordingly located in the foot section 12 in the lower half uH 3 of the spike hole 3 and the waisted region 7 of the spike 2 is above this extension depth T 1, but in any case adjacent thereto, so that an interaction with the waisted region 7 can result.The introduced stretching point D (groove 11 in the main section 10 or in the foot section 12) ensures that the rubber of the tire matrix can expand even further in addition to the normal stretching during the pressing-in of the spike 2 into the spike hole 3. The surface of the inner wall 14 of the spike hole 3 can therefore additionally be elongated (in the depth direction T). If the rubber is subsequently heated, relaxed or relaxed for vulcanizing and / or activating the adhesion promoter 4, the rubber is prevented or at least reduced in effect due to the additional groove 11 or the increased extensibility, the surface 1 bof the tread 1 ais prevented from being constricted or curled in the depth direction T toward the foot portion 12 of the spike hole 3. The same occurs in the case of slower relaxation processes or creep processes in the rubber of the tire matrix. Furthermore, the increased extensibility also prevents or reduces the formation of air inclusions or cavities around the waisted region 7 of the spike 2, so that a cohesive or chemical connection (provided in this respect) between the rubber of the tread 1 aand the spike 2 is improved by the adhesion promoter 4.In order to be able to introduce the spike hole 3 described above with the respective expansion point D (groove 11 in the main section 10 or in the foot section 12) into the running surface 1 a, a shaped pin 15 is provided, which is described below with reference to FIG. 5. The mold pin 15 has a fixing section 16 which is introduced into a receptacle 17 of a vulcanization segment 18 of a vulcanization device 19, for example by pressing or screwing in. The mold pin 15 is fixed to the vulcanization segment 18 in such a way that the mold pin 15 protrudes perpendicularly therefrom and as a result a spike hole 3 protruding perpendicularly into the surface 1 bof the running surface 1 acan be formed, in which the contour of the mold pin 15 is depicted. The fixing portion 16 of the mold pin 15 also protrudes slightly from the vulcanization segment 18 so that the step 13 is formed in the tread 1a around the spike hole 3. The spike hole 3 formed by such a shaped pin 15 is generally approximately 1 mm shorter than the spike 2 to be pressed in, the length of which, depending on the application, can be, for example, between 7 mm and 14 mm.The fixing section 16 merges in the longitudinal direction X of the forming pin 15 via a frustoconical mouth region 20 ainto a main forming section 20. The frustoconical opening region 20 aherein has the complementary contour to the frustoconical opening region 10 aof the spike hole 3. In the main mold portion 20, at a fixed strain height H 1 (measured from the surface of the vulcanization segment 18) corresponding to the strain depth T 1 in the spike hole 3, a boss 21 annularly extends on an outer wall 23 of the mold pin 15 so that the outer wall 23 expands radially outward within a boss height T 21 by a boss width R 21. The elevation 21 can be arranged in a lower half uH 15 of the mold pin 15 on the main mold section 20, corresponding to FIG. 4A, or in an upper half oH 15 of the mold pin 15. the elevation width R 21 is comparable to the groove width R 11, for example, between 0.1 mm and 1 mm and the elevation height T 21, for example, between 0.5 mm and 3 mm. This elevation 21 has a curved or convex cross section, i.e. complementary to the groove 11 in the spike hole 3.On the underside, the forming pin 15 then merges from the main forming section 20 into a foot forming section 22, wherein the foot forming section 22 is widened in the radial direction R (with respect to the forming pin 15) with respect to the main forming section 20. The foot-shaped portion 22 has a third radial extent r 3 which corresponds at least to 1.5 times, preferably at least to twice, a fourth radial extent r 4 of the main shaped portion 20. For example, the third radial extent r 3 can be between 1.5 mm and 3 mm and the fourth radial extent r 4 can be between 0.75 mm and 1.5 mm. The foot-shaped portion 22 thus also protrudes significantly further in the radial direction R than the elevation 21 with the elevation width R 21 arranged on the outer wall 23 of the shaped pin 15. Accordingly, r3>>r4+R21applies.According to the solution shown in FIGS. 3 and 4C, the elevation 21 can also be formed in the foot-shaped section 22 in the outer wall 23 of the shaped pin 15, i.e. in the lower half uH 15 of the shaped pin 15, as indicated by dashed lines in FIG. 5. The extension height D 1 is then thus located in the foot shaped portion 22, and the elevation 21 accordingly projects, for example perpendicularly, annularly circumferentially around the elevation width R 21 from the outer wall 23 of the shaped pin 15 in the region of the foot shaped portion 22 of the shaped pin 15. As a result, during vulcanization, a groove 11 can be formed as an elongation point D in the base portion 12 of the spike hole 3.List of reference characters1 Pneumatic vehicle tire 1 a Lauffläche surface of the pneumatic vehicle tire 1 1 bSurface of the tread 1 a 2 Spike 3 Spike hole 4 Adhesion promoter 5 Pin 5 aFree end of the pin 5 6 Main flange 6 a Oberer region of the main flange 6 7 waisted region 8 Foot flange 9 Transition 10 Main portion 10 a Mündungs region of the main portion 10 11 Groove 12 Foot portion 13 Step 14 Inner wall of the spike hole 3 15 Mold pin 16 Fixing portion 17 Receptacle 18 Vulcanization segment 19 Vulcanization device 20 Main mold portion 20 a Mündungs region of the main mold portion 20 21 Elevation 22 Foot mold portion 23 Outer wall of the mold pin 15 A Spike protrusion D Expansion point H 1 Expansion height oH 3 Obere half of the spike hole 3 oH 15 Obere half of the shaped pin 15 L longitudinal central axis of the spike hole 3 r 1 first radial extent of the foot portion 12 r 2 second radial extent of the main portion 10 r 3 third radial extent of the foot shaped portion 22 r 4 fourth radial extent of the main shaped portion 20 R radial direction R 11 groove width of the groove 11 R 21 protrusion width of the protrusion 21 T depth direction T 1 extension depth T 11 groove height of the groove 11 T 21 protrusion height of the protrusion 21 U underlying surface uH 3 lower half of the spike hole 3 uH 15 lower half of the shaped pin 15 X longitudinal directionReferences included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedEP 2 641 754 B1

[0003]

Claims

A mold pin (15) for a vulcanization segment (18) of a vulcanization device (19) for forming a spike hole (3) in a tread (1a) of a pneumatic vehicle tire (1), wherein the mold pin (15) comprises: - a fixing portion (16) for fixing the mold pin (15) in the vulcanization segment (18); - a main mold portion (20), wherein the main mold portion (20) adjoins the fixing portion (16) in the longitudinal direction (X); and - a foot-shaped portion (22), which adjoins the main shaped portion (20) in the longitudinal direction (X) and which is widened with respect to the main shaped portion (20) in a radial direction (R) for forming a foot portion (12) in the stud hole (3) during the production of the pneumatic vehicle tyre (1); characterized in that at least one elevation (21), which extends annularly around the shaped pin (15) and differs from the radially widened foot-shaped portion (22) of the shaped pin (15), is arranged on an outer wall (23) of the shaped pin (15) for forming at least one expansion point (D) which extends annularly in an inner wall (14) of the stud hole (3) during the production of the pneumatic vehicle tyre (1).The mold pin (15) according to claim 1, characterized in that the at least one elevation (21) has an elevation width (R21) of between 0.1 mm and 1 mm and / or an elevation height (T21) of between 0.5 mm and 3 mm.The forming pin (15) according to claim 1 or 2, characterized in that the at least one elevation (21) is arranged in the main forming section (20), wherein the outer wall (23) of the spike hole (3) widens in the radial direction (R) in the region of the main forming section (20) in order to form the elevation (21).The mold pin (15) according to any one of the preceding claims, characterized in that the at least one elevation (21) is located in an upper half (oH15) of the mold pin (15) adjoining the fixing section (16) or in a lower half (uH15) of the mold pin (15).The mold pin (15) according to any one of the preceding claims, characterized in that the at least one elevation (21) is arranged in the foot mold section (22), wherein the at least one elevation (21) protrudes from the outer wall (23) of the mold pin (15) in the region of the foot mold section (22), preferably protrudes perpendicularly.The mold pin (15) according to one of the preceding claims, characterized in that two elevations (21) spaced apart from one another in the longitudinal direction (X) are provided on the mold pin (15).The mold pin (15) according to any one of the preceding claims, characterized in that the at least one elevation (21) has a curved cross section, in particular a convex cross section.Vulcanization device (19) having a plurality of vulcanization segments (18) arranged in a circle for producing a pneumatic vehicle tyre (1), wherein a fixing portion (16) of a mold pin (15) according to one of the preceding claims is in each case accommodated in receptacles (17) in the respective vulcanization segment (18) in such a way that the main mold portion (20) and the foot mold portion (22) of the respective mold pin (15) project perpendicularly from the respective vulcanization segment (18).Pneumatic vehicle tyre (1) having a tread (1a) and spike holes (3) arranged in the tread (1a), in particular produced in a vulcanization device (19) according to Claim 8, wherein a spike (2) can be introduced into the spike holes (3), in each case, the spike holes (3) having: - a main section (10), wherein the main section (10) protrudes from a surface (1b) of the tread (1a) into the tread (1a) starting in a depth direction (T), for receiving a main flange (6) of the spike (2); and - a foot section (12), which adjoins the main section (10) in the depth direction (T) and which is widened with respect to the main section (10) in a radial direction (R) for receiving a foot flange (8) of the spike (2); characterized in that at least one groove (11), which extends annularly around the spike hole (3) and differs from the radially widened foot section (12) of the spike hole (3), is introduced into an inner wall (14) of the spike hole (3) for forming at least one expansion point (D) in the spike hole (3).Pneumatic vehicle tyre (1) according to Claim 9, characterized in that the at least one groove (11) has a groove width (R11) of between 0.1 mm and 1 mm and / or a groove height (T11) of between 0.5 mm and 3 mm.Pneumatic vehicle tyre (1) according to Claim 9 or 10, characterized in that the at least one groove (11) is arranged in the main section (10), wherein the inner wall (14) of the respective spike hole (3) widens in the radial direction (R) in the region of the main section (10) in order to form the groove (11).Pneumatic vehicle tyre (1) according to one of Claims 9 to 11, characterized in that the at least one groove (11) is located in an upper half (oH3) of the spike hole (3) adjoining the surface (1b) of the tread (1a), or in a lower half (uH3) of the spike hole (3).Pneumatic vehicle tyre (1) according to one of Claims 9 to 12, characterized in that the at least one groove (11) is arranged in the foot section (12), wherein the at least one groove (11) projects from the inner wall (14) of the spike hole (3) in the region of the foot section (12), preferably projects perpendicularly.Pneumatic vehicle tyre (1) according to one of Claims 9 to 13, characterized in that two grooves (11) which are spaced apart from one another in the depth direction (T) are arranged in the spike hole (3).

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