DE102017215858A1 - Method for producing spikes and pneumatic vehicle tires with such spikes - Google Patents

Abstract

The invention relates to a method for producing spikes, each having a spike pin (4) and a spike body (5), with the following successive steps:
a) forming at least in each case an undercut (3a) having spike holes (1) in the tread of a pneumatic vehicle tire during the vulcanization of the pneumatic vehicle tire in a vulcanization mold,
b) removing the pneumatic vehicle tire from the vulcanization mold,
c) filling a liquefied by heating thermoplastic Vulkanisates in at least one Spikeloch (1) and partial filling of the Spikelochs (1),
d) positioning a spike pin (4) in the thermoplastic vulcanizate,
e) filling the spike hole (1) with the liquefied thermoplastic vulcanizate while keeping the spike pin (4) in position,
f) releasing the spike pin (4),
g) repeating steps c) to f) until all of the stud holes (1) of the tread are provided with spikes.

Description

The invention relates to a method for producing spikes, each having a spike pin and a spike body.

Spikes are usually held by a combination of positive engagement and clamping in the Spikelöchern the tread of pneumatic vehicle tires. Conventional spikes usually consist of a spike body made of aluminum or steel, in which the over the tread surface protruding spike pin, which consists of hard metal is held.

If stones of the road surface and in particular grit of spreading material are rolled over by the tire in the vicinity of a conventional spike, then the profile deforms very much in the tread and "deviates" to the side. The fixed, rigid spike can not follow this "evasive movement". This creates a gap between spike and rubber, which thus exposes the top and lateral surface of the spike body to the abrasive attack of the stones. Since stones in the road surface and grit usually have a higher hardness than aluminum and even as steel, the spike body is very sharply ground, thereby reducing the spike height and the diameter of the spike body. This leads to the fact that the Spikelochkanten are exposed to a cutting abrasion. They erode, increasing the gap between the spike and the surrounding rubber matrix. This favors the penetration of sand and smaller stones, which further accelerates spike body abrasion. As a result, the lateral holding forces on the spike are reduced, which leads to a reduction of the winter properties due to heavy tilting, in the worst case to spike loss

It has therefore already been proposed to manufacture spiked bodies from non-metallic materials. From the DE 2 202 373 A1 For example, a method of making a spike from a spike body made of plastic and a spike pin made of hard metal is known. The spike body is produced, for example, by means of injection molding from a plastomer, a duromer or an elastomer and, after its production, has a cavity in which the spike pin is inserted while the spike body is set in ultrasonic vibrations. Such a tension-free embedding of the spike pin should be possible in the spike body.

From the DE 1 579 111 A1 It is known to provide spikes with an antislip and / or to fill such a spike in the stud holes in the tread before inserting the spike. The anti-slip agent causes after the insertion of the spikes in the Spikelöcher an adhesive bond between the spikes and the tread. For example, the antislip agent is a cold vulcanizing binder solution.

From the DE 10 2010 015 939 A1 It is known to glue spikes in stud holes of a tread with a two-part adhesive. The first component is injected into the spike hole, the second component is applied to the spike.

Spikes, in which the spike pin and / or the foot flange is at least partially integrated in a rubber jacket or in rubber material or are, for example, from WO 2017/088995 A1 known. The special advantages of these designs are the basic material properties of the rubber body. Due to its low density of approx. 1g / cm ³ , rubber is particularly light compared to aluminum and steel. The replacement of aluminum and steel by rubber as body material leads to a reduction of the spike weight, which has a particularly positive effect on the road wear and on the formation of fine dust. The road wear is mainly determined by the impact energy of the spike. The elastic material properties of the rubber have even more advantages. On the one hand, the elastic body material absorbs shocks, so that lower forces act on stones in the road surface or on particles of spreading material. Thus, the road wear and the fine dust formation are thereby also reduced.

The invention has for its object to provide a simple method for the production of spikes, with which spikes of non-metallic spiky bodies can be produced, which have the advantages of spiky bodies made of rubber and which is a particularly durable anchorage of the spikes in the tread of pneumatic vehicle tires ensures.

1. a) Ausformen von jeweils zumindest einen Hinterschnitt aufweisenden Spikelöchern im Laufstreifen eines Fahrzeugluftreifens während der Vulkanisation des Fahrzeugluftreifens in einer Vulkanisationsform,
2. b) Entnehmen des Fahrzeugluftreifens aus der Vulkanisationsform,
3. c) Einfüllen eines durch Erhitzen verflüssigten thermoplastischen Vulkanisates in zumindest ein Spikeloch und partielles Befüllen des Spikeloches,
4. d) Positionieren eines Spikepins im thermoplastischen Vulkanisat,
5. e) Anfüllen des Spikelochs mit dem verflüssigten thermoplastischen Vulkanisat während der Spikepin in seiner Position gehalten wird,
6. f) Freigeben des Spikepins,
7. g) Wiederholen der Schritte c) bis f) bis sämtliche Spikelöcher des Laufstreifens mit Spikes versehen sind.

The stated object is achieved according to the invention by a method which has the following successive steps:

1. a) molding of each at least one undercut having bead holes in the tread of a pneumatic vehicle tire during vulcanization of the pneumatic vehicle tire in a vulcanization mold,
2. b) removing the pneumatic vehicle tire from the vulcanization mold,
3. c) filling a liquefied by heating thermoplastic Vulkanisates in at least one Spikeloch and partial filling of the Spikeloches,
4. d) positioning a spike pin in the thermoplastic vulcanizate,
5. e) filling the spike hole with the liquefied thermoplastic vulcanizate while keeping the spike pin in position,
6. f) releasing the spike pin,
7. g) repeating steps c) to f) until all the stud holes of the tread have spikes.

A special feature of the method according to the invention is that the spike bodies of the spikes are created directly in the spikelet holes of the tread. This is done according to steps c) to f), in which the spike holes are filled with a thermoplastic vulcanizate. In the method according to the invention, the spike holes therefore form mold cavities for the liquefied thermoplastic vulcanizate, as a result of which the spike bodies are created in an optimum and accurately fitting final shape adapted to the respective spike hole. Due to its composition, the thermoplastic vulcanizate forms a particularly durable connection with the surrounding rubber material of the tread, so that spikes made according to the invention are anchored in the running stiffener in a particularly durable manner. Spiked bodies made of this material have very similar properties to rubber spiked bodies and therefore also have the advantages of rubber spike bodies. In addition, no or hardly any remnants of material accumulate during the production of the spiked bodies. The molded according to step a) Spikelöcher can be varied by simply replacing the so-called Moldpins, which are anchored to the inside of the vulcanization mold pins for forming the Spikelöcher, whereby the shape of the subsequently manufactured spike body can be selected accordingly. As a result, it is also possible to match the shape of the spike body to the material properties of the thermoplastic vulcanizate used in each case and thus to further improve the spike seat.

According to a preferred embodiment variant, in step a), the at least one undercut is formed on a groove-like widening of the spikelet hole. By such undercuts, a particularly tight fit between the spike body formed and the Spikeloch is achieved, whereby a particularly durable anchoring of the spike is ensured in the tread.

It is preferred if steps c) to f) are performed simultaneously on a plurality of body holes of the tread. The productivity of the process is thereby significantly increased. According to an alternative embodiment, steps c) to f) are carried out successively on the sprocket holes of the tread.

It is particularly preferred if the thermoplastic vulcanizate, which is filled in step c) in at least one Spikeloch, at least one thermoplastic from the group polyurethane, polypropylene, polystyrene, polyamide or acrylonitrile-butadiene-styrene copolymer. These thermoplastics show a very good compatibility with the rubber material of the tread, so that the thermoplastic vulcanizate with the tread can make a very good connection.

In this context, it is particularly advantageous if, according to a further preferred embodiment variant, the thermoplastic vulcanizate which is filled in at least one spike hole in step c) comprises an elastomer which is based on a rubber mixture containing at least one of the rubbers as rubber (e) from the group of natural rubber, synthetic polyisoprene, polybutadiene, styrene-butadiene rubber and nitrile-butadiene rubber.

The method is carried out in a particularly rational manner if the positioning of the spike pin according to step d) and the holding of the spike pin according to step e) are carried out by the same setting device.

According to a further preferred embodiment variant, the spike pin, which is positioned in step d), has at least one anchoring element, in particular a circumferential, protrusion-like design. Such spike pins are anchored particularly firmly in the curing thermoplastic vulcanizate in the course of the process.

It is also advantageous if the at least one anchoring element of the spike pin, which is positioned in step d), consists of metal, in particular of aluminum, or of hard metal. Spike spikes with aluminum anchoring elements have a lower weight compared to splike pins with cemented carbide anchoring elements.

It is also advantageous if the spike pin, which is positioned in step d), is provided with, in particular circumferential, notches. Alternatively or additionally, the spike pin, which is positioned in step d), at least in sections have a wave-shaped or zigzag-shaped outer contour.

According to a further preferred variant of the method, the spike pin is coated with an adhesion promoter before step d). This is the stop of the spike pin in the curing thermoplastic vulcanizate additionally improved.

The invention further relates to a pneumatic vehicle tire having a tread with spikelöchern which are equipped with spikes made according to the invention. The existing of a thermoplastic vulcanizate spike body have a particularly good abrasion resistance. In particular, the abrasion resistance of the spike body is very similar to that of the rubber material of the tread, so that treads and spiked bodies rub off to a similar extent.

Further features, advantages and details of the invention will now be described with reference to the drawing, which schematically illustrates an embodiment of the invention. Show

1 to 4 Partial cross sections in the radially outer region of a tread of a pneumatic vehicle tire in successive process stages in the production of a spike.

The figures show a partial cross section of a tread with a radial longitudinal section of a Spikelochs 1 , which was formed in a known manner in the course of vulcanization of the tread in these. The spike hole 1 is in particular rotationally symmetrical, has in the embodiment shown a substantially T-shaped longitudinal section and therefore a running from the surface of the tread in the tread in the radial direction, for example, circular cylindrical hole section 2 and a widening this groove-like widening 3 on. The dissemination 3 forms an undercut 3a ,

Like the arrow P ₁ in 2 indicates, for producing the spike by means of an injection device, not shown, a liquefied by heating thermoplastic vulcanizate in the Spikeloch 1 injected. At least the majority of the distribution 3 will, in particular, the broadening 3 to the undercut 3a , filled with the liquefied thermoplastic vulcanizate. Continuing the injection process is an existing particular hard metal spike pin 4 with a setting device, not shown in the radial direction and centric in the Spikeloch 2 and thus used in the already existing in this liquefied thermoplastic vulcanizate ( 3 ). Alternatively, the injection process can be interrupted briefly while the spike pin 4 in the spike hole 2 is set. As 3 shows, points the spike pin 4 at his inside the spike hole 1 positioned end portion at least one protrusion-like anchoring element 4a on which the spike pin 4 locally widened. In the embodiment shown, the spike pin 4 so in the Spikeloch 1 used that anchoring element 4a in the middle area of the broadening 3 protrudes.

While the mentioned setting the spike pin 4 continues to hold, is the Spikeloch 3 filled with the thermoplastic vulcanizate ( 4 ). Once the thermoplastic vulcanizate has cooled and thus cured, the setting device releases the spike pin 4 and thus free the finished spike already anchored in the tread. The spike produced in this way consists of a spike body of the cured thermoplastic vulcanizate and the spike pin anchored in it 4 made of tungsten carbide ( 4 ).

The thermoplastic vulcanizate is a blend of at least one thermoplastic and one elastomer, wherein the thermoplastic forms a continuous phase and the elastomer forms a finely dispersed disperse phase therein. In a thermoplastic vulcanizate therefore elastomer particles are surrounded by the thermoplastic. In the production of thermoplastic vulcanizates, at least one rubber is reactive compounded with a thermoplastic, wherein the forming rubber mixture is crosslinked in a phase-selective manner, so that the elastomer is formed from this. The preparation is preferably carried out in a shear field ("dynamic vulcanization"). The continuous phase forming thermoplastic is meltable, so that the thermoplastic vulcanizate is processable for example by injection molding.

The thermoplastic is or contains in particular at least one thermoplastic from the group polyurethane (PU), polypropylene (PP), polystyrene (PS), polyamide (PA) or acrylonitrile-butadiene-styrene copolymer (ABS). The rubber composition of the elastomer contains at least one rubber from the group of natural rubber (NR), synthetic polyisoprene (IR), polybutadiene (BR), styrene-butadiene rubber (SBR) and nitrile-butadiene rubber (NBR).

The invention is not limited to the embodiment described.

The spike pin is preferably coated with an adhesion promoter, for example Chemosil®, prior to insertion into the thermoplastic vulcanizate filled in the spike hole. Such coatings improve the connection of the spike pin in a known manner 4 with the thermoplastic vulcanizate.

Furthermore, the molded into the tread spikelet may have a deviating from the described longitudinal section longitudinal section and especially with a plurality in the radial direction formed one above the other Undercuts, for example, on groove-like circumferential broadening and the like, be provided. The spike pin may have a plurality of, preferably encircling, anchoring elements, further provided with a plurality of annular circumferential notches or the like as well as sections having a wave or zigzag outer contour. The anchoring elements consist in particular of the material of the spike pin or another metal, preferably aluminum.

Preferably, all spikelet holes formed in the tread of a vehicle tire are provided with spikes according to the method of the invention.

LIST OF REFERENCE NUMBERS

1

Spike hole

2

hole section

3

widening

3a

undercut

4

Spikepin

4a

anchoring element

5

Spike body

P ₁

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QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 2202373 A1 [0004]
• DE 1579111 A1 [0005]
• DE 102010015939 A1 [0006]
• WO 2017/088995 A1 [0007]

Claims (14)

Method for producing spikes, each having a spike pin (4) and a spike body (5), with the following successive steps: a) forming at least in each case an undercut (3a) having spike holes (1) in the tread of a pneumatic vehicle tire during the vulcanization of the pneumatic vehicle tire in a vulcanization mold, b) removing the pneumatic vehicle tire from the vulcanization mold, c) filling a liquefied by heating thermoplastic Vulkanisates in at least one Spikeloch (1) and partial filling of the Spikeloches (1), d) positioning a spike pin (4) in the thermoplastic vulcanizate, e) filling the spike hole (1) with the liquefied thermoplastic vulcanizate while keeping the spike pin (4) in position, f) releasing the spike pin (4), g) repeating steps c) to f) until all of the stud holes (1) of the tread are provided with spikes. Method according to Claim 1 , characterized in that in step a) the at least one undercut (3a) is formed on a groove-like circumferential widening (3). Method according to Claim 1 or 2 , characterized in that the steps c) to f) are carried out at a plurality of body holes (1) of the tread simultaneously. Method according to Claim 1 or 2 , characterized in that the steps c) to f) are performed successively on the stud holes (1) of the tread. Method according to one of Claims 1 to 4 , characterized in that the thermoplastic vulcanizate, which in step c) in at least one Spikeloch (1) is filled, at least one thermoplastic from the group polyurethane (PU), polypropylene (PP), polystyrene (PS), polyamide (PA) or Acrylonitrile-butadiene-styrene copolymer (ABS). Method according to one of Claims 1 to 5 , characterized in that the thermoplastic vulcanizate which is filled in at least one spike hole (1) in step c) comprises an elastomer which is based on a rubber mixture containing as rubber (e) at least one of the rubbers from the group of natural rubbers ( NR), synthetic polyisoprene (IR), polybutadiene (BR), styrene-butadiene rubber (SBR) and nitrile-butadiene rubber (NBR). Method according to one of Claims 1 to 6 , characterized in that the positioning of the spike pin (4) according to step d) and the holding of the spike pin (4) according to step e) are carried out by the same setting device. Method according to one of Claims 1 to 7 , characterized in that the spike pin (4), which is positioned in step d), at least one, in particular encircling, protrusion-like designed anchoring element (4a). Method according to Claim 8 , characterized in that the at least one anchoring element (4a) of the spike pin (4), which is positioned in step d), consists of metal, in particular of aluminum. Method according to Claim 8 , characterized in that the at least one anchoring element (4a) of the spike pin (4), which is positioned in step d), consists of hard metal. Method according to one of Claims 1 to 10 , characterized in that the spike pin (4), which is positioned in step d) is provided with particular circumferential notches. Method according to one of Claims 1 to 11 , characterized in that the spike pin (4), which is positioned in step d), at least in sections has a wave-shaped or zigzag-shaped outer contour. Method according to one of Claims 1 to 12 , characterized in that the spike pin (4) before step d) is coated with a bonding agent. A pneumatic vehicle tire having a tread with tread holes provided with spikes produced by the method according to one or more of Claims 1 to 13 are made.

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