DE102021209285A1 - Method of turning up sidewalls in the manufacture of vehicle tires with improved support in the lower bead area - Google Patents

Abstract

The invention relates to a method for turning up sidewalls in the manufacture of vehicle tires, in particular pneumatic vehicle tires, with a turning-up device, the first flank of a green tire being stabilized by a first shaping shoulder when turning up in the area of the first bead, the second flank of the green tire being Bouncing up in the area of the second bead is stabilized by a second shaping shoulder, the maximum shoulder height of the first and/or second shaping shoulder being set in a specific manner relative to the first and second holder.

Description

The invention relates to a method for turning up side walls in the manufacture of vehicle tires, in particular pneumatic vehicle tires, with a turning-up device, a method for manufacturing a vehicle tire using this method and a turning-up device for carrying out the method.

The subject matter of the invention is defined in the appended claims.

Various methods for manufacturing modern vehicle tires are known to those skilled in the art. The process in which a produced carcass ply is connected to a belt-tread package by cambering the carcass ply is of particular importance. With this procedure, the side walls of the green tire are usually produced on the same device that is also used for crowning. This is usually done by arranging the later side walls on both sides of the carcass together with the beads of the carcass in holders in order to be turned up after the tire carcass has been cambered. Various methods and devices are known for this step in the prior art and are for example in DE 10300969 A1 , DE 60302358 T2 or the DE 10 2013 108 759 A1 disclosed.

Of particular importance are those methods in which the sidewalls are turned up onto the flanks of the tire carcass or at least partially over the applied belt-tread package (so-called "sidewall over tread") by using crowning bellows, which are inflatable bellows, the expansion of which pushes up the sidewalls and presses them against the flanks of the tire carcass.

It is known from the state of the art that, for the purpose of a better execution of the turning up by means of bellows, a shoulder head or shoulder ring can be used, which can be inserted from below, ie. H. is moved from radially inside to radially outside on the drum-shaped device against the bending bellows in order to lift them with the side walls arranged on them and in this way to form a forming shoulder, whereby as an alternative to the movable variant there is also a corresponding forming shoulder with a rigid shoulder ring and one above it Bombing bellows can be used.

What the methods known from the prior art have in common is that the shaping shoulder, which is formed by the shoulder ring (or the shoulder head of the shoulder ring) and the bellows, is designed with a shoulder height at the moment of being turned up, which is usually around 50% of the height between the support for the bead of the carcasses and the height of the carcass after crowning, which is dictated by the position of the belt-tread package, as it is for example in the DE 10 2013 108 759 A1 is revealed.

In recent years, the complexity of the sidewalls that have to be turned up by means of appropriate methods has increased significantly, which have to meet the high requirements of modern pneumatic vehicle tires and are therefore becoming increasingly complex. Thus, today, instead of individual rubber walls, more complex side wall components are often folded up, which include, for example, additional reinforcement layers.

The inventors of the present invention have recognized that the method known from the prior art using high shoulders for the application of such complex side walls can be extremely disadvantageous. The background to this is that the great height of the conventional forming shoulders means that a large part of the side wall to be folded up rests on the steep slope of the shoulder before it is folded up and can slide down this slope due to tensions that arise in the material due to expansion of the shoulder. In particular, when there are multi-layer side walls whose individual components may not be firmly connected to one another, this steep arrangement can lead to unwanted slipping of these components, especially if stiff side wall components adapt poorly to the shape of the demolding shoulder. In the case of more complex tire constructions, this can lead to unwanted defects in the turned-up tire shoulder, which are often difficult to rectify and can result in a manufactured green tire having to be discarded.

The inventors of the present invention have recognized that the disadvantage of the prior art described above is particularly pronounced for the production of vehicle tires which have a low section height, i.e. a low height between tire bead and tread. Since corresponding tires are regularly to be produced on the same turn-up devices as tires with a large section height, a particularly high shoulder height is used in these relative terms, from which, however, the now shorter side walls slide off particularly easily.

It was the primary object of the present invention to eliminate or at least reduce the disadvantages known from the prior art.

In this case, it was in particular the task of specifying a method for turning up side walls in the manufacture of vehicle tires, with which the turning up can take place in a particularly controlled and reliable manner, so that tires with a low section height can also be reliably manufactured without the need to apply the Side walls can slip before folding up.

It was desirable here to specify suitable design measures with which the side walls can be efficiently stabilized before they are turned up.

In this respect, it was an additional object of the present invention to specify a method for producing vehicle tires with which particularly high-performance vehicle tires can be obtained which can be manufactured particularly precisely in the sidewall area in particular.

It was a requirement that the method to be specified should be particularly suitable for the use of more complex side walls, in particular in the case of side walls on which additional components such as reinforcement layers are arranged.

In addition, it was an object of the present invention to specify a roll-up device for carrying out the method to be specified.

The inventors of the present invention have now realized that the above objects can surprisingly be achieved if the maximum shoulder height of the forming shoulders used is reduced at the moment of turning up, as defined in the claims. In addition, the inventors of the present invention have identified it as particularly advantageous if the dimensions and the shape of the shaping shoulders are also adapted in order to be able to stabilize the side walls that are to be folded up particularly efficiently.

The above objects are accordingly achieved by the subject matter of the invention as defined in the claims. Preferred configurations according to the invention result from the dependent claims and the following statements.

Such embodiments, which are referred to below as preferred, are combined in particularly preferred embodiments with features of other embodiments referred to as preferred. Combinations of two or more of the embodiments described below as particularly preferred are therefore very particularly preferred. Also preferred are embodiments in which a feature of one embodiment identified as preferred to some extent is combined with one or more further features of other embodiments identified as preferred to some extent.

1. a) Herstellen oder Bereitstellen eines Gürtel-Laufstreifen-Pakets und einer Reifenkarkasse, umfassend auf gegenüberliegenden Seiten eine erste Wulst und eine zweite Wulst,
2. b) Anordnen der ersten Wulst in einer ersten Halterung der Hochschlagvorrichtung und Anordnen der zweiten Wulst in einer zweiten Halterung der Hochschlagvorrichtung,
3. c) Bombieren der Reifenkarkasse unter Verringerung des Abstandes zwischen der ersten Halterung und der zweiten Halterung sowie Kontaktieren der Reifenkarkasse mit dem Gürtel-Laufstreifen-Paket zum Einstellen einer Arbeitshöhe der ersten Flanke und der zweiten Flanke der Reifenkarkasse,
4. d) Hochschlagen einer auf einem ersten Bombierbalg positionierten ersten Seitenwand auf die erste Flanke und Hochschlagen einer auf einem zweiten Bombierbalg positionierten zweiten Seitenwand auf die zweite Flanke zum Erhalt eines Reifenrohlings, wobei das Hochschlagen durch Expansion des ersten und des zweiten Bombierbalgs erfolgt,

wobei die erste Flanke beim Hochschlagen im Bereich der ersten Wulst durch eine erste Ausformschulter stabilisiert wird, die dazu eingerichtet ist, die Reifenkarkasse im Wulstbereich zu stabilisieren, wobei der erste Bombierbalg Teil der ersten Ausformschulter ist und auf einem ersten Schulterkopf aufliegt,
wobei die zweite Flanke beim Hochschlagen im Bereich der zweiten Wulst durch eine zweite Ausformschulter stabilisiert wird, die dazu eingerichtet ist, die Reifenkarkasse im Wulstbereich zu stabilisieren, wobei der zweite Bombierbalg Teil der zweiten Ausformschulter ist und auf einem zweiten Schulterkopf aufliegt,
wobei in Verfahrensschritt d) die maximale Schulterhöhe der ersten und/oder zweiten Ausformschulter beim Beginn der Expansion des ersten und des zweiten Bombierbalgs relativ zur ersten bzw. zweiten Halterung im Bereich von 10 bis 40 % der Arbeitshöhe liegt.The invention relates to a method for turning up side walls in the manufacture of vehicle tires, in particular pneumatic vehicle tires, with a turning-up device, comprising the method steps:

1. a) producing or providing a belt-tread package and a tire carcass, comprising a first bead and a second bead on opposite sides,
2. b) placing the first bead in a first holder of the turnup device and placing the second bead in a second holder of the turnup device,
3. c) crowning the tire carcass while reducing the distance between the first holder and the second holder and contacting the tire carcass with the belt-tread package to set a working height of the first flank and the second flank of the tire carcass,
4. d) turning up a first sidewall positioned on a first inflation bladder onto the first flank and turning up a second sidewall positioned on a second inflation bladder onto the second flank to obtain a green tire, wherein the inflation takes place by expansion of the first and second inflation bladders,

the first flank being stabilized in the region of the first bead by a first shaping shoulder which is designed to stabilize the tire carcass in the bead region, the first crowning bellows being part of the first shaping shoulder and resting on a first shoulder head,
the second flank being stabilized in the region of the second bead by a second shaping shoulder which is set up to stabilize the tire carcass in the bead region, the second crowning bellows being part of the second shaping shoulder and resting on a second shoulder head,
wherein in method step d) the maximum shoulder height of the first and/or second shaping shoulder at the beginning of the expansion of the first and second bending bellows relative to the first or second holder is in the range of 10 to 40% of the working height.

In the method according to the invention, a belt-tread package and a tire carcass are manufactured or provided. The production can take place using a method known to the person skilled in the art from the prior art.

In accordance with expert understanding, the tire carcass has a so-called bead on both sides of the tire carcass formed into a ring, with which the firm seat of the vehicle tire on the rim is ensured in the subsequent vehicle tire.

To build up the tire, the beads on both sides of the tire carcass are placed in the holders of the turning-up device provided for this purpose. Depending on the design of the sidewall to be turned up, this is usually done together with the lower area of the sidewall to be turned up, so that the respective sidewall to be turned up together with the respective attached bead is fixed in the holder. Accordingly, a method according to the invention is preferred, wherein one end of the first side wall and/or the second side wall is arranged in the first holder or the second holder of the turning-up device.

Proceeding from this arrangement, the tire carcass is then crowned, with the distance between the holders being reduced, so that the crowned tire carcass is pressed against the belt-tread package, which is thereby connected to the tire carcass. This crowning step, which brings the tire carcass closer in the direction of the later tire shape, forms flanks on both sides of the tire carcass, onto which the side walls are later to be applied.

In the context of the present invention, the height of the flanks that occurs when they come into contact with the belt/tread package is the so-called working height. In the context of the present invention, this working height is measured from the bottom of the holders in which the beads of the carcass are arranged to the lower edge of the belt-tread package and thus to the surface of the tire carcass in contact with the belt-tread package at this point . In the most relevant case of a rotationally symmetrical structure, for example on a drum-shaped device, this height is determined in the direction pointing radially outwards.

The sidewalls are turned up onto the flanks of the cambered tire carcass by inflating a ballooning bladder located under the sidewalls. The two sides of the cambered tire carcass are thereby stabilized by the so-called shaping shoulders, which are formed by the cambering bellows, in that each of these rests on a shoulder head, i. H. the part of a shoulder ring intended to form the shaping shoulder.

In the method according to the invention, it is now provided that the maximum shoulder height, i.e. the height of the shaping shoulder at the highest point, measured in the radially outward-pointing direction, is set in a specific range, so that at the beginning of the expansion of the first and second bellows, i.e. H. the expansion serving for turning up, has a maximum shoulder height. This maximum shoulder height must be in the range of 10 to 40% of the working height, i. H. it must be 10 to 40% of the height specified by the belt-tread package and the location of the brackets.

In accordance with the understanding of those skilled in the art, hereby the arrangement at the beginning of the turning up of the side walls, i. H. defined at the start of expansion and the first and second bladders. It is therefore the beginning of the very expansion of the bellows that is ultimately also responsible for the side walls lifting up. A determination of the maximum shoulder height at a point in time before the actual opening would not be relevant for the purposes of the invention, if the shaping shoulder is first shaped, for example, by pushing up the bellows through the shoulder head, even if a slight expansion of the bellows should take place.

Due to the reduced shoulder height of the forming shoulder, it is surprisingly possible to increase the wrap around the shoulder by the side wall, so that a larger proportion of the side walls to be turned up protrudes beyond the extreme point of the forming shoulder, i.e. beyond the point of maximum shoulder height, causing the side wall to slip or individual sidewall components can be prevented in the direction of the carcass ply.

With the method according to the invention it is surprisingly possible to turn up complex side walls with several layers reliably and without slipping, in particular also in the manufacture of vehicle tires with a low working height in absolute terms.

In accordance with the understanding of the art, the maximum shoulder height in a fixed structural design of the device, i. H. with a non-adjustable shoulder ring, the maximum shoulder height of the forming shoulder at rest, d. H. the highest point of the demolding shoulder at rest. If a height-adjustable forming shoulder is used, which can be changed, for example, by moving the shoulder ring, the maximum shoulder height to be set in the method according to the invention corresponds to the highest point of the shoulder at the point in time at which the folding device has reached the shoulder height provided for folding up by expansion of the bomber bellows , i.e. the highest point of the forming shoulder at the moment of turning up.

It is clear to those skilled in the art of tire manufacture that vehicle tires and their components are highly symmetrical parts. As discussed above, during tire manufacture, sidewall turn-up typically occurs simultaneously on both sides of the tire carcass. Correspondingly, within the scope of the present invention, most of the work steps are mostly carried out on both sides using elements of the same type. It is clear to the person skilled in the art that an improvement in the known production method could basically be achieved simply by turning up only one side of the vehicle tire using the method according to the invention. This may even be preferable in some cases, for example when a complex sidewall is to be applied to one side only in the production of tires for specific applications, which cannot be applied with the same quality using the methods known from the prior art. However, it is readily apparent to a person skilled in the art that it is particularly preferred to use the method according to the invention or preferred embodiments of the method according to the invention simultaneously on both sides of the tire carcass, i. H. to be used to turn up the first and second side wall on the first and second flank.

To avoid misunderstandings, it is made clear that within the scope of the present invention, relative information and references always refer to the same side of the tire carcass and the elements present there or work steps carried out. For example, the height of the first demolding shoulder is sensibly determined in relation to the first bracket, with the first side wall resting on the first bellows, which in turn is part of the first demolding shoulder and is shaped by the first shoulder head to form the first flank in the first bead area of the first to stabilize the bead.

It is also clear to the person skilled in the art that the present method is a processing of essentially rotationally symmetrical components and that the devices used also take this form into account. Accordingly, the tire carcass and the belt-tread package are regularly ring-shaped, with the carcass being arranged in circumferential holders and the ring-shaped side walls being turned up by circumferential crowning bellows, which are formed into shaping shoulders by a substantially ring-shaped shoulder head of a shoulder ring.

In principle, preference is given to a method according to the invention, in which the method is carried out on a crowning drum. A method according to the invention is also fundamentally preferred, in which the tire carcass is produced on a carcass drum.

It can be mentioned as a great advantage of the method according to the invention that it is associated with advantages for one- and two-stage tire manufacturing methods and can be used flexibly in both variants. However, the use in single-stage tire construction processes is seen as particularly advantageous. A method according to the invention is therefore also preferred, the method being a single-stage tire construction method.

In view of the usual dimensions of modern vehicle tires, the inventors of the present invention were able to determine absolute height ranges for the maximum shoulder height, i. H. identify the highest point of the demolding shoulder, with which particularly good process results can be achieved. A method according to the invention is preferred in which the first and/or the second shaping shoulder in method step d) has a maximum shoulder height in the range from 15 to 50 mm, preferably in the range from 20 to 35 mm, at the beginning of the expansion of the first and the second bellows. more preferably in the range 25 to 30mm, relative to the first and second mounts.

In order to adjust the low maximum shoulder heights of the demolding shoulders, it has proven expedient to dimension the shoulder heads differently. A method according to the invention is therefore preferred, in which the first and/or the second shoulder head are rounded, preferably rounded in a substantially circular manner. In that regard, it is particularly preferred if the shoulder heads essentially have a circular cross section, with the diameter preferably being in Range of 10 to 40%, preferably 15 to 35%, more preferably 20 to 30% of the working height.

In order to ensure that as large a proportion of the sidewalls as possible, which are to be turned up later, rests stably on the forming shoulders, the inventors of the present invention propose that the forming shoulders, viewed from the carcass, after passing through the maximum shoulder height, should have a reduction in height and, for example, no plateau should form. A method according to the invention is therefore preferred, in which the height of the first and/or the second shaping shoulder in method step d) decreases at the beginning of the expansion of the first and second bending bellows from the first or second holder after passing through the maximum shoulder height.

Even if it is fundamentally possible to design the roll-up device with fixed shaping shoulders, which may even be preferable for certain applications for reasons of cost, it is seen as particularly advantageous if the shaping shoulders are designed to be adjustable in height, for example by means of reversible and non-destructively height-adjustable shoulder heads. This is particularly advantageous in order to be able to use the method according to the invention on the same turn-up device for different tires with different section heights. Accordingly, a method according to the invention is preferred, wherein the first and/or the second shaping shoulder, preferably via the first or second shoulder head, is designed to be reversible and non-destructively adjustable in height.

As explained above, the method according to the invention is particularly advantageous if not only one-piece side walls are to be turned up, but those that consist of several components and are therefore particularly susceptible to individual components slipping down. In the case of such methods, the advantages of the method according to the invention are particularly pronounced. A method according to the invention is therefore preferred, in which one or more components are additionally arranged on the first and/or the second side wall, which are selected from the group consisting of reinforcement layers, preferably selected from the group consisting of bead reinforcements, separate hardened rubber profiles without reinforcement , separate rubber profiles applied by means of strip winding and multi-component side wall profiles.

In order to ensure the most stable possible fixation of the tire carcass in the turn-up device, the inventors of the present invention propose providing bead cores in the beads, which impart a special degree of stability. A method according to the invention is therefore preferred, in which the first and/or the second bead have bead cores.

Based on the basic idea of the invention, the inventors of the present invention were able to identify a narrower height range for the shaping shoulders, with which particularly favorable process results can be achieved and with which slipping off laid side walls can be prevented particularly reliably. A method according to the invention is preferred, in which the maximum shoulder height of the first and/or second shaping shoulder in method step d) at the beginning of the expansion of the first and second bomber bellows relative to the first and second holder is in the range of 10 to 35%, preferably 15 to 30% % of working height.

In addition or as an alternative to defining the maximum shoulder height relative to the working height, the inventors of the present invention propose that this can also be specified efficiently in relation to the length of the turned up side walls, as this represents a comparably useful reference point. Particularly in the manufacture of tires in which the sidewalls or parts of the sidewall should not extend over the entire height of the flank, the relative orientation along the length of the sidewall can represent a useful additional or alternative constraint. Accordingly, a method according to the invention is preferred, wherein in method step d) the maximum shoulder height of the first and/or second demolding shoulder at the beginning of the expansion of the first and second bomber bellows relative to the first and second holder is in the range of 10 to 40% of the length of the folded-up first and / or second side wall is located.

In order to ensure that the process is as efficient as possible and the best possible stabilization of the side walls on the shaping shoulders, the inventors of the present invention propose that the shaping shoulder should have a specific shape, with the point of maximum shoulder height being at a specific distance from the bead of the carcass or .should have to the brackets provided for this purpose. A method according to the invention is preferred, wherein in method step d) at the start of the expansion of the first and second bellows, the ratio of the maximum shoulder height of the first and/or second demolding shoulder to the distance between the position of the maximum shoulder height and the first or second bead is in the range of 0 .5 to 2, preferably in the range of 0.75 to 1.5.

In this respect, a method according to the invention is also particularly preferred, in which the connecting line between the highest point of the shaping shoulder and the base of the shaping shoulder that is in contact with the tire carcass forms an angle of 45° with the maximum shoulder height or the working height or the radially outward-pointing direction or less, preferably 40° or less, more preferably 35° or less.

• e) Vulkanisieren des Reifenrohlings zum Erhalt des Fahrzeugreifens.

The invention also relates to a method for producing a vehicle tire, in particular a pneumatic vehicle tire, comprising the method steps of the method according to the invention for turning up side walls, additionally comprising the method step:

• e) Vulcanizing the green tire to obtain the vehicle tire.

The method according to the invention is advantageous because with it, using the method according to the invention for turning up sidewalls, green tires with defect-free sidewalls can be obtained particularly reliably, which can be converted into vehicle tires corresponding to specifications.

• v1) eine erste Halterung und eine zweite Halterung zur Aufnahme der Wülste einer Reifenkarkasse, wobei der Abstand zwischen der ersten Halterung und der zweiten Halterung verringert werden kann,
• v2) eine Halterung zur Anordnung eines Gürtel-Laufstreifen-Pakets in einer Arbeitshöhe über der ersten Halterung und der zweiten Halterung, und
• v3) eine erste Ausformschulter umfassend einen ersten Bombierbalg und eine zweite Ausformschulter umfassend einen zweiten Bombierbalg, die dazu eingerichtet sind, eine in der ersten und zweiten Halterung angeordnete Reifenkarkasse im Wulstbereich zu stabilisieren, wobei der erste Bombierbalg auf einem ersten Schulterkopf aufliegt, wobei der zweite Bombierbalg auf einem zweiten Schulterkopf aufliegt,

wobei die maximale Schulterhöhe der ersten und/oder zweiten Ausformschulter relativ zur ersten und zweiten Halterung vor Beginn der Expansion des ersten und des zweiten Bombierbalgs im Bereich von 10 bis 40 % der Arbeitshöhe liegt.The invention also relates to a roll-up device for carrying out the method according to the invention, comprising

• v1) a first mount and a second mount for receiving the beads of a tire carcass, wherein the distance between the first mount and the second mount can be reduced,
• v2) a holder for arranging a belt and tread package at a working height above the first holder and the second holder, and
• v3) a first shaping shoulder comprising a first crowning bellows and a second shaping shoulder comprising a second crowning bellows, which are set up to stabilize a tire carcass arranged in the first and second holder in the bead area, the first crowning bellows resting on a first shoulder head, the second bulging bellows rests on a second shoulder head,

wherein the maximum shoulder height of the first and/or second demolding shoulder relative to the first and second fixture prior to commencement of expansion of the first and second ballooning bladders is in the range of 10 to 40% of the working height.

The above turn-up device is preferred because the method according to the invention can be carried out with it and the advantages described result from this.

• 1 eine schematische Darstellung des Querschnitts durch eine Hochschlagvorrichtung bei der Durchführung des eines nicht erfindungsgemäßen Verfahrens zum Hochschlagen von Seitenwänden zu einem ersten Zeitpunkt;
• 2 eine schematische Darstellung des Querschnitts durch eine Hochschlagvorrichtung bei der Durchführung des eines nicht erfindungsgemäßen Verfahrens zum Hochschlagen von Seitenwänden zu einem zweiten Zeitpunkt;
• 3 eine schematische Darstellung des Querschnitts durch eine Hochschlagvorrichtung bei der Durchführung des eines nicht erfindungsgemäßen Verfahrens zum Hochschlagen von Seitenwänden zu einem dritten Zeitpunkt;
• 4 eine schematische Darstellung einer beispielhaften Anordnung aus Reifenkarkasse, Seitenwand und Ausformschulter in einer theoretischen, nicht erfindungsgemäßen Ausführungsform;
• 5 eine schematische Darstellung einer beispielhaften Anordnung aus Reifenkarkasse, Seitenwand und Ausformschulter in einer erfindungsgemäßen Ausführungsform.

Preferred embodiments of the invention are explained and described in more detail below with reference to the accompanying drawings. show:

• 1 a schematic representation of the cross section through a turning-up device when carrying out a method for turning up side walls, not according to the invention, at a first point in time;
• 2 a schematic representation of the cross section through a turning-up device when carrying out a method, not according to the invention, for turning up side walls at a second point in time;
• 3 a schematic representation of the cross section through a turning-up device when carrying out a method, not according to the invention, for turning up side walls at a third point in time;
• 4 a schematic representation of an exemplary arrangement of tire carcass, sidewall and molding shoulder in a theoretical embodiment not according to the invention;
• 5 a schematic representation of an exemplary arrangement of tire carcass, sidewall and molding shoulder in an embodiment of the invention.

The 1 until 3 visualize the sequence of the basic method for turning up sidewalls in tire manufacture in an embodiment not according to the invention.

A tire carcass 14 is placed in opposite supports 18a, 18b of the turn-up device 10 with the beads 16a, 16b located on opposite sides. In the illustrated embodiment, this arrangement already takes place in such a way that the lower parts of the side walls 24a, 24b are also positioned in the holders 18a, 18b and are connected there to the beads 16a, 16b of the tire carcass 14.

In 1 the side walls 24a, 24b lie on the still taut crowning bellows 22a, 22b. In 2 It can then be seen how the shoulder heads 28a, 28b are moved radially outwards and in doing so pre-form the crowning bellows 22a, 22b in the form of a provisional shaping shoulder, which allows initial stabilization of the tire carcass 14 in the bead area. The tire carcass 14 is then cambered and thereby reducing the Distance between the brackets 18a, 18b connected to the belt tread package 12. Here, the working height is set, which is shown in the schematic 3 as the longer double arrow is drawn.

3 visualizes the state immediately before the side walls 24a, 24b hit the flanks 20a, 20b of the tire carcass 14 by expansion of the ballooning bellows 22a, 22b. The maximum shoulder height of the shaping shoulders 26a, 26b, which is relevant at this relevant point in time and which can be adjusted by the shoulder heads 28a, 28b, is shown in the schematic illustration in FIG 3 indicated by the smaller double arrow. From the comparison of the maximum shoulder height with the working height it can be seen that in 3 no method according to the invention is shown.

The 4 shows a schematic enlargement of the bead area on a flank 20a of the tire carcass 14, in which the first bead 16a is arranged in the first holder 18a together with the first side wall 24a to be folded up later, the first side wall 24a resting on the first shaping shoulder 26a. The working height and the maximum shoulder height of the first shaping shoulder 26a are again entered by the double arrows. The maximum shoulder height of the first demolding shoulder 26a is about 45% in this theoretical example, not according to the invention, whereby it can be seen that the first side wall 24a due to the steep and high demolding shoulder due to the stresses generated by the expansion of the demolding shoulder with a relatively low wrap around the demolding shoulder has a relatively experiences large restoring force in the direction of the tire carcass 14 and in the bead area an unfavorable initial situation for the turning up by means of the bomber bellows (not shown here) is generated.

In contrast, shows 5 with a basically similar structure of an embodiment that can be used in a method according to the invention. The maximum shoulder height of the first shaping shoulder 26a relative to the first holder 18a is only about 23% based on the working height, which achieves a particularly favorable stabilization of the first side wall 24a before it is turned up and creates an advantageous contact situation in the bead area. In the example shown, the maximum shoulder height is 25 mm, for example, and is produced by a rounded first shoulder head 28a, which has an essentially circular cross section with a diameter of 25 mm, so that this diameter also corresponds to approximately 23% of the working height.

The height of the first shaping shoulder 26a decreases, viewed outwards from the tire carcass 14, after the maximum shoulder height has been reached, thereby enabling the first side wall 24a to be laid down in a particularly stable manner. in the in 5 example shown, the first shoulder head 28a is designed to be reversible and non-destructively adjustable in height. In the 5 The first side wall 24a shown in the example shown additionally comprises a bead reinforcement (not shown) arranged on the first side wall 24a.

It can be seen that the first bead 16a has a bead core that enables particularly stable positioning in the first holder 18a. The ratio of the maximum shoulder height of the first shaping shoulder 26a to the horizontal distance between the position of the maximum shoulder height and the first bead 16a is approximately 1.0, resulting in a particularly favorable geometry in the contact area of the first side wall 24a. The connecting line between the highest point of the shaping shoulder 26a and the base of the shaping shoulder 26a in contact with the tire carcass encloses an angle of approximately 35° with the maximum shoulder height or the working height or the radially outward-pointing direction.

As explained above, all of the schematic 1 until 5 Cross-sections through a structure that is rotationally symmetrical per se, as can be realized, for example, on a crowning drum.

Reference List

10

flip-up device

12

Belt tread package

14

tire carcass

16a, 16b

First and second bead

18a,18b

First and second bracket

20a,20b

First and second flank

22a,22b

First and second bellows

24a,24b

First and second side wall

26a,26b

First and second demolding shoulder

28a,28b

First and second shoulder head

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was 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.

Patent Literature Cited

• DE 10300969 A1 [0003]
• DE 60302358 T2 [0003]
• DE 102013108759 A1 [0003, 0006]

Claims (10)

Method for turning up side walls in the manufacture of vehicle tires, in particular vehicle pneumatic tires, with a turning-up device (10), comprising the method steps: a) producing or providing a belt-tread package (12) and a tire carcass (14), comprising a first bead (16a) and a second bead (16b) on opposite sides, b) arranging the first bead (16a) in a first holder (18a) of the turn-up device (10) and arranging the second bead (16b) in a second holder (18b) of the turn-up device (10), c) crowning the tire carcass (14) while reducing the distance between the first holder (18a) and the second holder (18b) and contacting the tire carcass (14) with the belt-tread package (12) to adjust a working height of the first flank (20a) and the second flank (20b) of the tire carcass (14), d) Folding up a first side wall (24a) positioned on a first bellows (22a) onto the first flank (20a) and folding up a second side wall (24b) positioned on a second bellows (22b) onto the second flank (20b) to obtain a Green tyre, wherein the turning up takes place by expansion of the first and second ballooning bellows (22a, 22b), the first flank (20a) being stabilized in the area of the first bead (16a) by a first shaping shoulder (26a), which is set up for this purpose, when turning up is to stabilize the tire carcass (14) in the bead area, the first ballooning bellows (22a) being part of the first shaping shoulder (26a) and resting on a first shoulder head (28a), wherein the second flank (20b) is stabilized in the region of the second bead (16b) by a second shaping shoulder (26b) when it is turned up, which is set up to stabilize the tire carcass (14) in the bead region, the second ballooning bellows (22b) being part the second forming shoulder (26b) and rests on a second shoulder head (28b), wherein in method step d) the maximum shoulder height of the first and/or second shaping shoulder (26a, 26b) at the beginning of the expansion of the first and second bellows (22a, 22b) relative to the first or second holder (18a, 18b) is in the range of 10 to 40% of the working height. procedure after claim 1 , wherein the first and/or the second shoulder head (28a, 28b) are rounded, preferably rounded in a substantially circular manner. Procedure according to one of Claims 1 or 2 , wherein the height of the first and/or the second shaping shoulder (26a, 26b) in method step c) at the beginning of the expansion of the first and the second bending bellows (22a, 22b) from the first or second holder (18a, 18b) decreases Passing through the maximum shoulder height decreases. Procedure according to one of Claims 1 until 3 , wherein the first and/or the second shaping shoulder (26a, 26b) are designed to be reversible and non-destructively adjustable in height. Procedure according to one of Claims 1 until 4 , wherein one or more components are additionally arranged on the first and/or the second side wall (24a, 24b), which are selected from the group consisting of reinforcement layers, preferably selected from the group consisting of bead reinforcements, separate hardened rubber profiles without reinforcements, separate rubber profiles and multi-component side wall profiles applied by means of strip winding. Procedure according to one of Claims 1 until 5 , wherein the maximum shoulder height of the first and/or second shaping shoulder (26a, 26b) in method step c) at the beginning of the expansion of the first and second bending bellows (22a, 22b) relative to the first and second holder (18a, 18b) is in the range of 10 to 35%, preferably 15 to 30%, of the working height. Procedure according to one of Claims 1 until 6 , wherein the maximum shoulder height of the first and/or second shaping shoulder (26a, 26b) in method step c) at the beginning of the expansion of the first and second bending bellows (22a, 22b) relative to the first and second holder (18a, 18b) in the area from 10 to 40% of the length of the turned-up first and/or second side wall (24a, 24b). Procedure according to one of Claims 1 until 7 , wherein in method step c) at the beginning of the expansion of the first and second bending bellows (22a, 22b), the ratio of the maximum shoulder height of the first and/or second shaping shoulder (26a, 26b) to the distance of the position of the maximum shoulder height from the first or second bead (16a, 16b) is in the range from 0.5 to 2, preferably in the range from 0.75 to 1.5. Method for producing a vehicle tire, in particular a pneumatic vehicle tire, comprising the method steps of the method according to one of Claims 1 until 8th , additionally comprising the method step: e) vulcanizing the green tire to obtain the vehicle tire. Turn-up device (10) for carrying out the method according to one of Claims 1 until 8th , comprising v1) a first holder (18a) and a second holder (18b) for receiving the beads of a tire carcass (14), wherein the distance between the first holder (18a) and the second holder (18b) can be reduced, v2) a holder for arranging a belt-tread package (12) at a working height above the first holder (18a) and the second holder (18b), v3) a first shaping shoulder (26a) comprising a first crowning bellows (22a) and a second shaping shoulder (26b) comprising a second crowning bellows (22b) which are set up to stabilize a tire carcass (14) arranged in the first and second holder (18a, 18b) in the bead area, the first crowning bellows (22a) being mounted on a first shoulder head ( 28a), the second bending bellows (22b) resting on a second shoulder head (28b), the maximum shoulder height of the first and/or second shaping shoulder (26a, 26b) relative to the first and second holder being in the region of vo n 10 to 40% of the working height.

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