DE102021115987A1 - Method and device for cleaning at least one mold segment of a tire mold using laser radiation - Google Patents

Abstract

Method for cleaning at least one mold segment of a tire mold by means of laser radiation, wherein the at least one mold segment has at least part of a surface to be cleaned; wherein a beam path of the laser radiation defines an intersection with the surface to be cleaned; and wherein the jet path is rotatable about an axis of rotation to thereby move the point of intersection across the surface to be cleaned; the method comprising aligning the axis of rotation of the jet path with respect to the at least one mold segment, positioning the jet path with respect to the axis of rotation in a first cleaning position, the first cleaning position defining at least the following on an average over time: (i) a first angle between the jet path and a plane perpendicular to the axis of rotation, (ii) a distance between a line along the beam path and the axis of rotation, and (iii) a position on the axis of rotation that is a minimum distance from the line along the beam path; the method further comprising guiding the jet path in the first cleaning position over an angular range of at least 20° over the surface to be cleaned by rotating the jet path about the axis of rotation.

Description

TECHNICAL AREA

The present disclosure relates to the field of tire mold cleaning.

BACKGROUND

the DE10 2013 220 066 B3 discloses a method of cleaning a surface of a cavity in a tire mold or in a tire.

SUMMARY

There is a need for a technique that allows efficient cleaning of a tire mold.

This need is met by the independent claims. Advantageous embodiments are specified in the dependent claims.

According to a first aspect of the subject matter disclosed herein, a method of cleaning using laser radiation is disclosed.

According to an embodiment of the first aspect, a method for cleaning at least one mold segment of a tire mold by means of laser radiation is disclosed, wherein the at least one mold segment defines at least a part of a surface to be cleaned; and a beam path of the laser radiation defines an intersection with the surface to be cleaned and wherein the beam path is rotatable about an axis of rotation to thereby move the intersection point across the surface to be cleaned; the method comprising: aligning the axis of rotation of the beam path with respect to the at least one mold segment; positioning the beam path with respect to the axis of rotation in a first cleaning position, the first cleaning position defining at least the following on a time average: i. a first angle between the beam path and a plane perpendicular to the axis of rotation, ii. a distance between a straight line along the beam path and the axis of rotation and iii. a position on the axis of rotation that is a minimum distance from the straight line along the beam path; and wherein the method further comprises sweeping the jet path in the first cleaning position over an angular range of at least 20 degrees across the surface to be cleaned by rotating the jet path about the axis of rotation.

According to a second aspect of the subject matter disclosed herein, a cleaning device is disclosed.

According to an embodiment of the second aspect, a cleaning device for cleaning at least one mold segment of a tire mold by means of laser radiation is disclosed, wherein the at least one mold segment defines at least a part of a surface to be cleaned; the cleaning device comprising: a beam path along which the laser radiation propagates and which defines an intersection with the surface to be cleaned; an axis of rotation about which the jet path is rotatable to thereby move the point of intersection across the surface to be cleaned; a first actuator assembly for aligning the axis of rotation of the beam path with respect to the at least one mold segment; a second actuator arrangement for positioning the beam path with respect to the axis of rotation in a first cleaning position, wherein the first cleaning position on average over time defines at least the following: i. a first angle between the beam path and a plane perpendicular to the axis of rotation, ii. a distance between a straight line along the beam path and the axis of rotation and iii. a position on the axis of rotation that is a minimum distance from the straight line along the beam path; a third actuator arrangement for guiding the jet path in the first cleaning position over an angular range of at least 20 degrees over the surface to be cleaned by rotating the jet path about the axis of rotation.

According to a third aspect of the subject matter disclosed herein, a controller is disclosed.

According to an embodiment of the third aspect, a control device for controlling a cleaning device is disclosed, wherein the control device is set up to carry out a method according to at least one embodiment of the first aspect.

According to a fourth aspect of the subject matter disclosed herein, a computer program product is disclosed.

According to an embodiment of the fourth aspect, a computer program is disclosed, the computer program product having a program element, wherein the program element is set up to carry out a method according to at least one embodiment of the first aspect when it is executed on a processor device.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Specifically, exemplary embodiments of the subject matter disclosed herein include more the embodiments and combinations of embodiments described below.

A mold segment of a tire mold according to embodiments of the subject matter disclosed herein defines at least a portion of a surface to be cleaned. According to a further embodiment, the mold segment is provided for molding part of an outer surface of a tire.

According to one embodiment, the at least one mold segment can be brought into a mold segment arrangement in which the at least one mold segment has at least part of the surface to be cleaned. In other words, the at least one mold segment defines at least part of the surface to be cleaned. According to a further embodiment, the at least one mold segment has the surface to be cleaned. According to a further embodiment, the surface to be cleaned has a mold base, with respect to which structural elements of the tire mold are raised or recessed, and the mold base is (by definition) rotationally symmetrical with respect to an axis of symmetry.

According to one embodiment, a beam path of a laser radiation, by means of which the at least one mold segment is cleaned, defines an intersection with the surface to be cleaned. According to a further embodiment, the jet path can be rotated about an axis of rotation in order to thereby move the point of intersection over the surface to be cleaned.

A method for cleaning at least one mold segment of a tire mold by means of laser radiation according to the first aspect comprises, according to one embodiment, aligning the axis of rotation of the beam path with respect to the at least one mold segment. According to a further embodiment, the method includes positioning the beam path with respect to the axis of rotation in a first cleaning position, wherein the first cleaning position defines a first angle of the beam path (or a straight line along the beam path) with a plane perpendicular to the axis of rotation on an average over time . Furthermore, the first cleaning position (at least in the time average) defines a position on the axis of rotation which is at a minimum distance from a straight line along the beam path. In other words, the position on the axis of rotation defines the spatial position of the beam path with respect to the axis of rotation in a longitudinal direction of the axis of rotation. Furthermore, according to one embodiment, the first cleaning position (at least in the time average) defines a distance between the straight line (which runs along the beam path) and the axis of rotation. According to a further embodiment, the method includes guiding the jet path in the first cleaning position over an angular range of at least 20 degrees over the surface to be cleaned by rotating the jet path about the axis of rotation.

According to one embodiment, the term “on the average over time” is synonymous with “when averaging over a predetermined period of time”, the predetermined period of time being the period of time over which an average is taken.

According to one embodiment, the axis of rotation is a physical axis of rotation in the sense that a bearing is provided which exclusively defines the ability to rotate about the axis of rotation. According to a further embodiment, the axis of rotation is a virtual axis of rotation that results from the interaction of at least two physical axes, such as can be implemented by a robot, for example. It goes without saying that in the case of a physical axis, the axis of rotation is defined exclusively by the bearing, while in the case of a virtual axis of rotation, suitable control of the at least two physical axes defines the position of the axis of rotation in space and ensures rotation around the virtual axis of rotation. According to one embodiment, rotating is rotating through an angular range that is less than 360 degrees. Rotating through an angular range that is less than 360 degrees is also referred to herein as pivoting. According to another embodiment, rotating is rotating at least 360 degrees.

According to one embodiment, during the rotation of the beam path about the axis of rotation in a direction of rotation, the beam path is guided back and forth transversely to the direction of rotation. According to one embodiment, the time average extends over multiple reciprocations and the first cleaning position is an averaged position averaged over the reciprocations. The back and forth movement can also be referred to as an oscillating movement (or as an oscillating movement). In other words, an oscillating movement of the beam path transverse to the direction of rotation (ie in a transverse direction) is superimposed on the rotating of the beam path in the direction of rotation. The oscillating movement of the beam path in the transverse direction, of course, results in an oscillating movement of the point of intersection in the transverse direction. Due to the oscillating movement of the beam path transverse to the direction of rotation about the axis of rotation, in a single cleaning position the laser radiation can sweep over an area whose extent in the transverse direction is greater than the extent of a laser spot located at the intersection point of the beam path with the surface to be cleaned formed by the laser radiation. According to one embodiment, the oscillating movement of the point of intersection extends over a length of up to 5 cm. According to other embodiments, the oscillating movement of the point of intersection can extend over a smaller length, for example 3 cm, or over a larger length, for example 7 cm. It will be appreciated that in a case where there is no reciprocating motion of the beam path, the beam path will enclose the first angle with the plane perpendicular to the axis of rotation at all times. According to one embodiment, if there is to and fro motion of the beam path, the angle between the beam path and the plane perpendicular to the axis of rotation changes over time, the time-average of this (time-varying) angle being equal to the first angle.

Instead of the first angle between the beam path and the plane that is perpendicular to the axis of rotation, a complementary angle can also be considered, which adds up to 90 degrees with the first angle (in other words, it always applies that the sum of the first angle α1 and the complementary angle α2 gives 90 degrees, α1 + α2 = 90 degrees). The complementary angle is the angle enclosed by a directional vector of the beam path and a directional vector of the axis of rotation. In accordance with further embodiments of the subject matter disclosed herein, reference to the first angle is replaced by reference to its complementary angle. In such an embodiment, for example, the first cleaning position does not define the first angle, but rather the complementary angle.

According to one embodiment, the transverse direction extends parallel to the axis of rotation. According to a further embodiment, the transverse direction extends at an acute angle to the axis of rotation, for example in an angular range lying between -10 and +10 degrees with respect to the axis of rotation.

It is understood that when the transverse direction and the axis of rotation have no point of intersection, the angle between the transverse direction and the axis of rotation is determined by the angle of the two directional vectors (i.e. the directional vector of the axis of rotation and the directional vector of the transverse direction) (analogous to the mathematical determination of the angle between skew straight lines). This can be understood in such a way that the transverse direction is shifted in parallel until it intersects the axis of rotation and then the angle between the axis of rotation and the transverse direction is determined. The above method for determining the angle between two non-intersecting axes or directions applies here generally to any direction/axis.

Similarly, it will be understood that when the plane perpendicular to the axis of rotation and the ray path do not intersect, the first angle between the plane and the ray path is defined by the angle between the directional vector of the ray path and the plane or, according to another embodiment, the first angle is defined by the angle between a straight line along the beam path and the plane perpendicular to the axis of rotation.

According to one embodiment, the oscillating movement is performed such that with the superimposed rotating of the beam path about the axis of rotation, the oscillating movement relative to the base of the mold takes place in a plane (also referred to herein as the plane of oscillation), the plane of oscillation rotating about the axis of rotation. According to one embodiment, the plane encloses an angle with the axis of rotation that is less than 70 degrees. According to one embodiment, this angle is in a range between 0 degrees and 45 degrees. For example, the angle is less than 15 degrees.

In order to define the plane due to the superimposed rotation of the beam path with respect to the base of the mold, the point of intersection of the beam path with the base of the mold generally describes the shape of a figure eight without the superimposed rotation.

According to one embodiment, the oscillating movement in the transverse direction occurs at a frequency which is a multiple, for example 50 times or 100 times, the frequency of rotation of the beam path about the axis of rotation.

According to one embodiment, laser radiation is coupled into the beam path which is suitable for cleaning the surface to be cleaned at the point of intersection (i.e. the point of intersection of the beam path and the surface to be cleaned). As the laser radiation is emitted along the beam path, the surface to be cleaned is cleaned in an area swept by the intersection point. Cleaning of at least part of the surface to be cleaned while the jet path is in the first cleaning position is also referred to herein as "cleaning in the first cleaning position".

According to one embodiment, the beam path is brought into a second cleaning position, for example subsequent to the cleaning in the first cleaning position. According to a further embodiment, the beam path is again rotated about the axis of rotation in the second cleaning position, for example by the same angular range by which the beam path was rotated in the first cleaning position.

According to one embodiment, rotating the jet path in the first cleaning position cleans a first part of the surface to be cleaned and rotating the jet path in the second cleaning position cleans a second part of the surface to be cleaned.

According to one embodiment, the first part of the surface to be cleaned and the second part of the surface to be cleaned are at least partially different from each other. For example, the first part of the surface to be cleaned can be arranged at a distance from the second part of the surface to be cleaned. According to a further embodiment, the first part of the surface to be cleaned and the second part of the surface to be cleaned at least partially overlap.

According to one embodiment, the at least one mold segment can be introduced into a mold segment arrangement, in which the at least one mold segment forms at least part of the mold segment arrangement. According to a further embodiment, the mold segment arrangement is closed in the form of a ring. According to a further embodiment, the mold segment arrangement forms only part of a ring-shaped closed tire mold. According to one embodiment, the cleaning of the at least one mold segment takes place while the at least one mold segment is arranged in the mold segment arrangement.

According to one embodiment, the mold segment arrangement defines a rotationally symmetrical surface which is closed in the form of a ring and rotationally symmetrical with respect to an axis of symmetry. According to one embodiment, the rotationally symmetrical surface is an imaginary surface.

For example, the rotationally symmetrical surface is an imaginary envelope surface which is rotationally symmetrical with respect to an axis of symmetry and which is an envelope of the surface to be cleaned. In other words, the imaginary enveloping surface surrounds the surface to be cleaned in such a way that it completely envelops the surface to be cleaned, but is overall rotationally symmetrical with respect to the axis of symmetry. Furthermore, the enveloping surface is the one with the smallest surface area among all surfaces that meet the above condition. In other words, the imaginary envelope surface is the envelope of the surface to be cleaned, which is rotationally symmetrical (and therefore defines the axis of symmetry) and which has a minimal surface area. The imaginary enveloping surface also encloses structural elements of the mold segment, for example indentations that are recessed in relation to the base of the mold.

Structural elements are, for example, elevations of the mold segment, which are raised relative to the imaginary mold base and/or depressions of the mold segment, which are concave in relation to the imaginary mold base. It should be noted here that ventilation openings are not structural elements within the meaning of the present disclosure, as are all through-holes which extend through the mold segment.

According to a further embodiment, the rotationally symmetrical surface is defined by an imaginary mold base area, in relation to which structural elements of the mold segment are designed to be raised or recessed. In other words, the base of the mold extends along the imaginary base of the mold, with the imaginary base of the mold also being defined in the area of the elevations/depressions.

• - dem ersten Winkel, den der Strahlweg mit der Ebene einschließt, die senkrecht zu der Drehachse ist,
• - einem zweiten Winkel, den der Strahlweg mit der rotationssymmetrischen Fläche einschließt,
• - einem Abstand eines Fokuspunktes des Strahlwegs von der rotationssymmetrischen Fläche,
• - einem Abstand eines Schnittpunkt des Strahlwegs und der rotationssymmetrischen Fläche von der Drehachse,
• - dem Abstand der Geraden längs des Strahlwegs von der Drehachse.

According to one embodiment, the first cleaning position and the second cleaning position differ in the time average of at least one of the following parameters:

• - the first angle that the beam path includes with the plane that is perpendicular to the axis of rotation,
• - a second angle that the beam path encloses with the rotationally symmetrical surface,
• - a distance of a focal point of the beam path from the rotationally symmetrical surface,
• - a distance of an intersection of the beam path and the rotationally symmetrical surface from the axis of rotation,
• - the distance of the straight lines along the beam path from the axis of rotation.

Above, the definite article is used if the parameter or size in question has already been used. Nevertheless, the parameters or quantities (e.g. the first angle, the beam path, the distance between the straight line (along the beam path) and the axis of rotation, etc.) are defined for both the first cleaning position and the second cleaning position and can generally be the first cleaning position and in the second cleaning position can be different from each other. For example, according to one embodiment, the first angle is different for the first and second cleaning positions. In other words, in this case the angle that the jet path makes in the first cleaning position with a plane that is perpendicular to the axis of rotation is different from the angle that the jet path makes in the second cleaning position position with a plane perpendicular to the axis of rotation.

According to one embodiment, a position of the beam path designates a position of the beam path with respect to the axis of rotation and/or the rotationally symmetrical surface, the position being a position averaged over the oscillating movement. According to one embodiment, the position of the beam path is therefore constant when the beam path rotates about the axis of rotation.

According to one embodiment, the point of intersection of the beam path with the rotationally symmetrical surface defines a plane, which is also referred to herein as the plane of rotation, perpendicular to the axis of rotation by rotating the beam path about the axis of rotation in the time average (i.e., for example, after forming an averaged position from an oscillating movement). If the movement of the beam path comprises an oscillating movement transverse to the direction of rotation, according to one embodiment the time averaging (the averaged position) takes place over at least one period of the oscillating movement, for example over at least 10 periods of the oscillating movement. According to one embodiment, a plane of rotation of the first cleaning position differs from a plane of rotation of the second cleaning position. For example, according to one embodiment, the plane of rotation of the first cleaning position (first plane of rotation) is at a distance from the plane of rotation of the second cleaning position (second plane of rotation), for example a distance of more than 1 cm. The distance between the planes of rotation corresponds to the distance between the positions on the axis of rotation from which the straight line along the beam path has the smallest distance in each case in the first and the second position.

According to a further embodiment, the plane of rotation of a cleaning position can be defined by the point of intersection of the beam path (in this cleaning position) with the imaginary enveloping surface, optionally as an average over time.

According to a further embodiment, the plane of rotation of a cleaning position can be defined by the point of intersection of the beam path (in this cleaning position) with the rotationally symmetrical surface (e.g. the imaginary envelope surface or the imaginary mold base surface), optionally in a time average (e.g. averaged in a manner as specified herein .

According to one embodiment, in the first cleaning position, a third angle that a projection of the beam path encloses in a plane that is perpendicular to the axis of rotation with a radial direction is less than 30 degrees (for example less than 20 degrees). Unless otherwise stated, the radial direction always refers to a radial direction with respect to the axis of rotation.

According to one embodiment, the surface to be cleaned is cleaned by bringing the jet path into a plurality of cleaning positions and rotating the jet path about the axis of rotation in each cleaning position (for example by the angular range). According to one embodiment, the plurality of cleaning positions include the first cleaning position and the second cleaning position. According to one embodiment, at least 90% of the surface to be cleaned is reached at least one of the cleaning positions of the plurality of cleaning positions by the beam path of the laser at an angle that is less than 60 degrees (or, according to another embodiment, is less than 45 degrees or according to yet another embodiment, is less than 30 degrees) with respect to the normal of the surface to be cleaned. With a smaller angle with respect to the normal of the surface to be cleaned, the energy input per area is large enough to ensure efficient cleaning.

According to one embodiment, all of the cleaning positions in the plurality of cleaning positions are selected in such a way that the number of cleaning positions required to clean the entire area to be cleaned is minimized. According to one embodiment, the cleaning positions are selected here by setting at least one of the parameters described herein (at least one of the parameters in which the cleaning positions (for example the first cleaning position and the second cleaning position) can differ).

1. (i) eine Fluenz in einem Bereich zwischen 1 J/cm² bis 5 J/cm², beispielsweise 2 J/cm² bis 3 J/cm² (J/cm² = Joule pro Quadratzentimeter). Für feine Oberflächenstrukturen (feine Strukturelemente, beispielsweise Strukturgrößen und Strukturabstände kleiner 1 mm (Mikrostrukturen, beispielsweise Mikrolichtfallenstrukturen, welche eine geringere optische Reflektivität bewirken) kann beispielsweise eine Fluenz zwischen 1,0 J/cm² bis 1,5 J/cm² geeignet sein. Gemäß einer Ausführungsform wird ein Oberflächenbereich mehrfach in der gleichen Reinigungsposition des Strahlwegs mit der Laserstrahlung beaufschlagt. Auf diese Weise kann der Energieeintrag in die Oberfläche reduziert werden. Erfahrungsgemäß verträgt Stahl (aus welchem beispielsweise Seitenschalen der Reifenform gefertigt sein können) weniger Energie pro Puls, da er sonst anläuft. Geeignete Werte für die Fluenz pro Puls sind bei Stahl beispielsweise 1 J/cm² bis 2 J/cm².
2. (ii) eine Wellenlänge in einem Bereich zwischen 0,5 µm und 10 µm, beispielsweise 1 µm, beispielsweise 1030 nm oder 1064 nm (µm = Mikrometer; nm = Nanometer).
3. (iii) eine Pulsfrequenz in einem Bereich zwischen 0,1 kHz und 100 kHz, beispielsweise 10 kHz - 40 kHz (kHz = Kilohertz). Gemäß einer weiteren Ausführungsform liegt die Pulsfrequenz in einem Bereich zwischen 1 kHz und 500 kHz. Es versteht sich, dass die Pulsfrequenz typischerweise abhängig ist vom verwendeten Laser und dem optischen Layout. Allerdings können Ausführungsformen von hierin offenbarten Verfahren auf einfache Weise an die Taktfrequenz angepasst werden (die daher nicht verfahrenskritisch ist), beispielsweise durch Anpassen der für das Reinigen der Form benötigten Taktzeit. Eine höhere Reinigungsgeschwindigkeit, d. h. eine höhere Relativgeschwindigkeit zwischen Strahlweg und der zu reinigenden Oberfläche, kann beispielsweise bei annähernd gleicher Reinigungswirkung durch entsprechende Erhöhung der Pulsfrequenz realisiert werden.
4. (iv) eine Pulsdauer in einem Bereich zwischen 0,5 ns bis 5 µs, beispielsweise 1 ns bis 1000 ns (µs = Mikrosekunden; ns = Nanosekunden). Gemäß einer weiteren Ausführungsform liegt die Pulsdauer in einem Bereich zwischen 30 ns bis 240 ns. Beispielsweise kann je nach verwendetem Laser die Pulsdauer unveränderbar sein (beispielsweise 30 ns) oder kann auf Werte zwischen 70 ns und 240 ns einstellbar sein. Gemäß einer Ausführungsform ist die Reinigungseffizienz abhängig von der Pulsleistung, d.h. je kürzer die Pulse, desto effizienter ist die Reinigung.
5. (v) einen Pulsüberlapp in einem Bereich zwischen 0 % (kein Überlapp) und 90 %, beispielsweise 40 % - 80%. Gemäß einer Ausführungsform wird ein Pulsüberlapp von ca. 66 % gewählt. Gemäß einer Ausführungsform ist der Pulsüberlapp durch die Pulsfrequenz und die Relativgeschwindigkeit zwischen Strahlweg und zu reinigender Oberfläche gegeben.
6. (vi) eine Rayleighlänge in einem Bereich zwischen 10 mm und 200 mm, beispielsweise 10 mm bis 100 mm (mm = Millimeter). Gemäß einer weiteren Ausführungsform liegt die Rayleighlänge in einem Bereich zwischen 20 mm bis 60 mm, beispielsweise bei 40 mm.

According to one embodiment, the laser radiation has at least one of the following laser parameters (i) to (vi):

1. (i) a fluence in a range between 1 J/cm ² to 5 J/cm ² , for example 2 J/cm ² to 3 J/cm ² (J/cm ² = joules per square centimeter). A fluence of between 1.0 J/cm ² and 1.5 J/cm ² may be suitable, for example, for fine surface structures (fine structural elements, for example structure sizes and structure spacings of less than 1 mm (microstructures, for example micro light trap structures, which cause a lower optical reflectivity). According to one embodiment, a surface area is repeatedly exposed to the laser radiation in the same cleaning position of the beam path.In this way, the energy input into the surface can be reduced will. Experience has shown that steel (from which, for example, side shells of the tire mold can be made) tolerates less energy per pulse, otherwise it will tarnish. In the case of steel, suitable values for the fluence per pulse are, for example, 1 J/cm ² to 2 J/cm ² .
2. (ii) a wavelength in a range between 0.5 µm and 10 µm, for example 1 µm, for example 1030 nm or 1064 nm (µm = micrometres; nm = nanometres).
3. (iii) a pulse frequency in a range between 0.1 kHz and 100 kHz, for example 10 kHz - 40 kHz (kHz = kilohertz). According to a further embodiment, the pulse frequency is in a range between 1 kHz and 500 kHz. It goes without saying that the pulse frequency typically depends on the laser used and the optical layout. However, embodiments of methods disclosed herein can easily be adapted to the cycle frequency (which is therefore not process-critical), for example by adjusting the cycle time required for mold cleaning. A higher cleaning speed, ie a higher relative speed between the jet path and the surface to be cleaned, can be achieved, for example, with approximately the same cleaning effect by increasing the pulse frequency accordingly.
4. (iv) a pulse duration in a range between 0.5 ns to 5 µs, for example 1 ns to 1000 ns (µs = microseconds; ns = nanoseconds). According to a further embodiment, the pulse duration is in a range between 30 ns and 240 ns. For example, depending on the laser used, the pulse duration can be unchangeable (for example 30 ns) or can be adjustable to values between 70 ns and 240 ns. According to one embodiment, the cleaning efficiency depends on the pulse power, ie the shorter the pulses, the more efficient the cleaning.
5. (v) a pulse overlap in a range between 0% (no overlap) and 90%, for example 40% - 80%. According to one embodiment, a pulse overlap of about 66% is chosen. According to one embodiment, the pulse overlap is given by the pulse frequency and the relative speed between the beam path and the surface to be cleaned.
6. (vi) a Rayleigh length in a range between 10 mm and 200 mm, for example 10 mm to 100 mm (mm = millimetres). According to a further embodiment, the Rayleigh length is in a range between 20 mm and 60 mm, for example 40 mm.

1. (i) eine Absaugung benachbart zu dem Schnittpunkt des Strahlwegs mit der zu reinigenden Oberfläche;
2. (ii) eine automatische Durchführung der Ausrichtung der Drehachse der Strahlwegs bezüglich des mindestens einen Formsegments. Gemäß einer Ausführungsform erfolgt die Ausrichtung durch Ausrichten der Symmetrieachse (d.h. der Symmetrieachse, der durch die Formsegmentanordnung definierten, rotationssymmetrischen Fläche) und der Drehachse (d.h. die Drehachse, um welche der Strahlweg drehbar ist). Gemäß einer weiteren Ausführungsform ist das Ausrichten ein fluchtendes Ausrichten der Symmetrieachse und der Drehachse. Beispielsweise kann gemäß einer Ausführungsform eine automatische Durchführung der fluchtenden Ausrichtung der Symmetrieachse der gedachten Formgrundfläche und der Drehachse erfolgen. Gemäß einer anderen Ausführungsform kann eine automatische Durchführung einer fluchtenden Ausrichtung der Symmetrieachse der gedachten Hüllfläche und der Drehachse erfolgen. Gemäß einer Ausführungsform kann die automatische Durchführung des Ausrichtens ein Ermitteln der Symmetrieachse mittels einer Laser-Abstandsmessung umfassen, beispielsweise mittels einer Messung des Abstands der Segmentanordnung von der Drehachse unter Verwendung eines Laser-Messstrahls.
3. (iii) das Positionieren des Strahlwegs in der ersten Reinigungsposition erfolgt über mindestens fünf mechanische Achsen, beispielsweise fünf mechanische Achsen und eine optische Achse. Beispielsweise erfolgt das Positionieren des Strahlwegs in der ersten Reinigungsposition über fünf mechanische Achsen und einen Fokusschieber, mittels welchem der Fokus der Laserstrahlung auf der zu reinigenden Oberfläche platzierbar ist.

According to one embodiment, the method has at least one of the following features:

1. (i) an exhaust adjacent the intersection of the jet path with the surface to be cleaned;
2. (ii) automatically performing the alignment of the axis of rotation of the beam path with respect to the at least one mold segment. According to one embodiment, the alignment is performed by aligning the axis of symmetry (ie the axis of symmetry of the rotationally symmetrical surface defined by the mold segment arrangement) and the axis of rotation (ie the axis of rotation about which the beam path is rotatable). According to a further embodiment, the alignment is an aligned alignment of the axis of symmetry and the axis of rotation. For example, according to one embodiment, the alignment of the axis of symmetry of the imaginary mold base and the axis of rotation can be carried out automatically. According to another embodiment, the axis of symmetry of the imaginary enveloping surface and the axis of rotation can be aligned automatically. According to one embodiment, the automatic implementation of the alignment can include determining the axis of symmetry by means of a laser distance measurement, for example by measuring the distance of the segment arrangement from the axis of rotation using a laser measuring beam.
3. (iii) the positioning of the beam path in the first cleaning position takes place via at least five mechanical axes, for example five mechanical axes and one optical axis. For example, the beam path is positioned in the first cleaning position via five mechanical axes and a focus slide, by means of which the focus of the laser radiation can be placed on the surface to be cleaned.

According to one embodiment, at least one mold segment of the at least one mold segment has at least one vent valve. According to a further embodiment, the vent valve is a vent valve with a spring mechanism. According to one embodiment, at least one of the laser parameters disclosed herein is adapted to clean the vent valve. According to one embodiment, the mold segment, which has a venting valve, has at least one through hole through which the tire mold is vented. In order to avoid visually unappealing rubber extensions, it is known that the through hole with a vent to close the valve. Such vent valves are generally difficult to clean and are also sensitive. The laser cleaning is thorough and yet gentle here, so that the vent valve (even with a spring mechanism) can remain installed during cleaning.

According to one embodiment, a fluence of the laser radiation is reduced and an irradiation time is increased in order to clean the at least one vent valve. For example, according to one embodiment, the irradiation duration is increased by at least one of the following measures: increasing the pulse overlap; slowing down of all axis movements; Stopping all axis movements. According to one embodiment, the fluence is reduced and the duration of irradiation increased depending on whether the point of intersection of the radiation path with the surface to be cleaned is on the vent valve or next to a vent valve. According to one embodiment, reducing the fluence and increasing the exposure time is done automatically by a controller according to embodiments of the subject matter disclosed herein. According to one embodiment, the positions of the venting valves are stored in a data memory and can be called up by the control device in order to control the laser parameters, in particular the fluence and the irradiation duration, accordingly. According to a further embodiment, a sensor device is provided, which emits a sensor signal to the control device, which indicates the vent valve to the control device. According to one embodiment, the control device is set up to adapt at least one laser parameter to the presence of the vent valve in such a case. According to one embodiment, a fluence when cleaning a vent valve is adjusted (for example, compared to a smooth section of the surface to be cleaned, the fluence when cleaning the vent valve can be reduced).

According to one embodiment, the sensor device is set up for direct detection of a vent valve by a camera. According to a further embodiment, the sensor device is set up to detect the position of the at least one mold segment and to emit the sensor signal based on the position of the at least one mold segment and the knowledge of the position of the vent valves relative to the at least one mold segment.

According to one embodiment, at least one mold segment of the at least one mold segment has a microstructure. According to one embodiment, the microstructure has structure sizes in a range between 20 μm and 1 mm. According to a further embodiment, the microstructure has structure sizes between 20 μm and 500 μm. According to yet another embodiment, the microstructure has structure sizes in a range between 70 μm and 300 μm.

According to a further embodiment, the microstructure has an aspect ratio which is greater than 0.5. The aspect ratio AV is defined here as the extension h of a structural element of the microstructure perpendicular to the imaginary mold base divided by the smallest extension b of the structural element in the imaginary mold base. In other words, the aspect ratio AV is defined by: $$\text{AV}=\text{H}/\text{b}$$

Accordingly, according to the above embodiment, AV > 0.5. According to another embodiment, AV > 0.8.

According to one embodiment, the microstructure has a surface whose area is more than twice (for example more than three times) the area of a section of the imaginary mold base over which the microstructure extends.

According to one embodiment, of the at least one microstructured mold segment, at least one mold segment defines a side shell of the tire mold, the side shell of the tire mold being for molding a sidewall of a tire. According to one embodiment, the side shell is made of steel.

According to one embodiment, at least one mold segment of the at least one mold segment is a tread segment provided for molding a tread of a tire. According to one embodiment, the profile segment is made of steel. According to another embodiment, the profile segment is made of aluminum.

According to one embodiment, to clean the microstructure, a fluence of the laser radiation is reduced and an irradiation time is increased or irradiated multiple times. This protects the microstructure. A reduction in the fluence of the laser radiation and an increase in the irradiation time can be implemented, for example, as described above with reference to the vent valves.

According to one embodiment, the beam path increases in the first cleaning position times rotated (e.g. panned or rotated) over the angle range.

According to one embodiment of the second aspect, a cleaning device for cleaning at least one mold segment of a tire mold by means of laser radiation (wherein the at least one mold segment defines/has at least part of a surface to be cleaned) has a beam path along which the laser radiation propagates and which has a Intersection defined with the surface to be cleaned. Furthermore, according to one embodiment, the cleaning device has an axis of rotation about which the beam path can be rotated in order to thereby move the point of intersection over the surface to be cleaned. According to a further embodiment, the cleaning device has a first actuator arrangement for aligning the axis of rotation of the jet path with respect to the at least one mold segment. According to one embodiment, the cleaning device has a second actuator arrangement for positioning the beam path with respect to the axis of rotation in a first cleaning position, wherein the beam path in the first cleaning position encloses a first angle with a plane that is perpendicular to the axis of rotation and a Position of the beam path defined along the axis of rotation. According to a further embodiment, the cleaning device has a third actuator arrangement for guiding the jet path in the first cleaning position over an angular range of at least 20 degrees over the surface to be cleaned by rotating the jet path about the axis of rotation.

According to a further embodiment, at least one actuator from one of the first actuator arrangement, the second actuator arrangement and the third actuator arrangement is also part of another one of the first actuator arrangement, the second actuator arrangement and the third actuator arrangement. For example, an actuator of the first actuator arrangement can also be an actuator of the second arrangement and/or an actuator of the third actuator arrangement.

According to an embodiment of the third aspect, a control device for controlling a cleaning device (eg for controlling the above-described cleaning device according to embodiments of the subject matter disclosed herein) is set up to carry out a method according to one or more embodiments of the subject matter disclosed herein.

According to one embodiment, the control device is part of a cleaning device according to the second aspect.

According to one embodiment, a computer program product according to the fourth aspect comprises a program element, wherein the program element is arranged, when executed on a processor device, to perform a method according to one or more embodiments of the subject matter disclosed herein.

According to one embodiment, the control device has a processor device and a data memory in which the program element is stored.

According to embodiments of the first aspect, the method is set up to provide the functionality of one or more of the embodiments disclosed herein and/or to provide the functionality as required for one or more of the embodiments disclosed herein, in particular the embodiments of the first aspect of the second aspect, third aspect and/or fourth aspect.

According to embodiments of the second aspect, the cleaning device is set up to provide the functionality of one or more of the embodiments disclosed herein and/or to provide the functionality as required for one or more of the embodiments disclosed herein, in particular the embodiments of the first aspect, the second aspect, third aspect and/or fourth aspect.

According to embodiments of the third aspect, the control device is configured to provide the functionality of one or more of the embodiments disclosed herein and/or to provide the functionality as required for one or more of the embodiments disclosed herein, in particular the embodiments of the first aspect of the second aspect, third aspect and/or fourth aspect.

According to embodiments of the fourth aspect, the computer program product is set up to provide the functionality of one or more of the embodiments disclosed herein and/or to provide the functionality as required for one or more of the embodiments disclosed herein, in particular the embodiments of the first aspect of the second aspect, third aspect and/or fourth aspect.

According to one embodiment, the program element is a non-transient program element. As used herein, reference to a computer program product is considered equivalent to reference to a computer program which has a program element and/or a computer-readable medium which has a program element. According to one embodiment, a program element comprises instructions for controlling a processor device (having one or more microprocessors, for example a computer system) for effecting and/or coordinating the execution of a method described herein.

The (non-transient) program element may be implemented as computer-readable instruction code using any suitable programming language, such as JAVA, C#, and stored on a computer-readable medium (removable disk, volatile or non-volatile memory, embedded memory/processor, etc.) be saved. According to one embodiment, the instruction code is executable to program a computer or any other programmable processor device to perform the intended functions. The computer program can be available on a network, for example the World Wide Web, from which it can be downloaded, for example.

The objects disclosed herein can be realized by means of a computer program product (program element) or software. However, the objects disclosed herein can also be implemented by one or more specific electronic circuits or hardware. Furthermore, the subject matter disclosed herein may also be in hybrid form, i. H. Realized in a combination of software modules and hardware modules.

Exemplary embodiments of the subject matter disclosed herein are described below, for example referring to a method for cleaning at least one mold segment of a tire mold using laser radiation and a cleaning device for cleaning at least one mold segment of a tire mold using laser radiation. It should be emphasized that any combination of features of different aspects, embodiments and examples is of course possible. In particular, some embodiments are described in relation to a method, while other embodiments are described in relation to an apparatus. Still other embodiments are described with reference to a computer program product, while other embodiments are described with reference to a controller for interacting with elements of the cleaning device. However, those skilled in the art will recognize from the foregoing and the following description, claims and drawings that, unless otherwise stated, features of various aspects, embodiments and examples can be combined and such combinations of features are to be considered as disclosed by this application. For example, even a feature that relates to a method can be combined with a feature that relates to a device, and vice versa.

Additional advantages and features of the present disclosure will become apparent from the following exemplary description of currently preferred embodiments, to which, however, the claimed invention is not limited. The individual figures of the drawings in this document are to be regarded as schematic only and are not drawn to scale.

character list

• 1 Figure 1 shows a cleaning device according to embodiments of the subject matters disclosed herein.
• 2 shows part of the cleaning device 1 with further explanations according to embodiments of the subject matter disclosed herein.
• 3 12 shows a mold segment assembly in accordance with embodiments of the subject matter disclosed herein.
• 4 Figure 12 shows a cross-sectional view along line IV - IV of a single mold segment 3 .
• 5 FIG. 12 shows a portion of a mold segment having a structural element in the form of a bump and a position of a beam path in accordance with embodiments of the subject matter disclosed herein.
• 6 shows part of a shape segment 5 and another position of the beam path in accordance with embodiments of the subject matter disclosed herein.
• 7 FIG. 12 schematically shows two laser spots according to embodiments of the subject matter disclosed herein.

DETAILED DESCRIPTION

It is noted that in different figures similar or identical elements or components are provided with the same reference numbers, or with reference numbers differing only in the first digit or a suffix letter. Those features or components that are the same or similar to the corresponding features or components in another figure are at least functionally equivalent are only described in detail when they first occur in the following text and the description is not repeated for subsequent occurrences of these features and components (or the corresponding reference numbers).

1 10 shows a cleaning device 100 in accordance with embodiments of the subject matter disclosed herein.

According to one embodiment, the cleaning device is set up to clean at least one mold segment 102 of a tire mold 104 using laser radiation 106. The at least one mold segment 102 defines at least part of a surface 108 to be cleaned.

According to one embodiment, the cleaning device 100 has a beam path 110 along which the laser radiation 106 propagates and which defines an intersection 112 with the surface 108 to be cleaned. According to one embodiment, the beam path 110 is tilted relative to a normal 176 to the surface 108 to be cleaned. Furthermore, the cleaning device 100 has an axis of rotation 114, about which the beam path 110 can be rotated in order to thereby move the intersection point 112 over the surface 108 to be cleaned.

According to one embodiment, the cleaning device has an actuator arrangement 116 for positioning the beam path 110 with respect to the axis of rotation 114 in a first cleaning position 118, wherein in the first cleaning position, on average over time, the beam path 110 encloses a first angle 119 with a plane 123 that is perpendicular to the Axis of rotation 114 and defines a location 122 along the axis of rotation 114 (ie, the beam path has location 122 along the axis of rotation 114 in the first cleaning position). According to one embodiment, location 122 is defined by a position on axis of rotation 114 that is a minimum distance from a straight line along beam path 110 . The axis of rotation 114 and the beam path 110 (more precisely their direction vectors) also define the complementary angle 120, which adds up to 90 degrees with the first angle 119. According to one embodiment, the position 122 along the axis of rotation can, for example, correspond to the position of a plane which is perpendicular to the axis of rotation 114 and whose point of intersection with a straight line through the beam path 110 has a minimum distance from the axis of rotation 114 . If the straight line through the beam path intersects the axis of rotation 114, this point of intersection with this plane corresponds to the point of intersection of the straight line through the beam path 110 with the axis of rotation 114 and corresponds to the position on the axis of rotation which defines the first position (among other things) (e.g. like in 1 shown, see reference number 122). It is understood that the plane which is perpendicular to the axis of rotation 114 and whose point of intersection with the straight line through the beam path 110 has a minimum distance from the axis of rotation 114 is also a plane 123 which defines the first angle 119 with the beam path, for example as in 1 shown.

According to a further embodiment, the cleaning device 100 has an actuator arrangement 124 for guiding the beam path 110 in the first cleaning position 118 over an angular range of at least 20 degrees over the surface 108 to be cleaned by rotating the beam path 110 about the axis of rotation 114. According to one embodiment, the Actuator arrangement 124 has an actuator 125, with which a laser device 126, which defines the beam path 110, can be rotated about the axis of rotation 114, for example as in FIG 1 shown.

Furthermore, according to one embodiment, the cleaning device 100 has an actuator arrangement 128 with which the axis of rotation 114 of the beam path 110 can be aligned with respect to the at least one mold segment 102 . For example, the actuator arrangement 128 has an actuator 130 with which a carrier 132, which carries the at least one mold segment 102, can be positioned relative to the beam path 110, for example as shown in FIG 1 shown. According to one embodiment, each actuator arrangement can have one or more dedicated actuators (ie an actuator that is only assigned to a single actuator arrangement) and/or one or more common actuators. For example, the actuator arrangement 128 for aligning the axis of rotation 114 with respect to the mold segment 102 can also have one or more actuators of the actuator arrangement 124, with which the beam path 110 can be pivoted (or rotated) over the angular range.

According to one embodiment, the cleaning device 100 has a control device 101, wherein the control device 101 is designed according to at least one embodiment of the subjects disclosed herein. For example, according to one embodiment, the control device 101 has a data memory 103 in which a program element is stored. Furthermore, the control device 101 has a processor device 105 . According to one embodiment, the program element is configured to, when executed on the processor device 105, perform a method disclosed herein. According to one embodiment, the control device 101 is connected to other components of the cleaning device 100 in terms of control in a known manner the (in 1 not shown), for example via fiber optic, wired or wireless connection means.

2 12 shows part of the cleaning device 100. FIG 1 with further explanations according to embodiments of the subject matter disclosed herein.

According to one embodiment, rotating the beam path 110 (an exemplary rotating is shown in 2 indicated at 134) transverse to the direction of rotation (indicated at 136 in 2 , starting from the configuration shown, the rotation takes place into the plane of the drawing) a back and forth movement (oscillating movement) in an oscillating direction 138 is superimposed. In other words, the beam path 110 moves transversely to the direction of rotation 136 between a first end position 140 and a second end position 142. On average over time, this oscillating movement results in a middle position 144 of the beam path 110, for example as in 2 shown.

According to one embodiment, the surface to be cleaned 108 is cleaned by first bringing the jet path into a first position (e.g. the middle position 144), the surface to be cleaned 108 is cleaned in this position (e.g. over a rotation angle of 360 degrees around the axis of rotation 114), and then the beam path 110 is brought into a second cleaning position 146 and the surface to be cleaned is cleaned in this second cleaning position 146 (for example also over a rotation angle of 360 degrees about the rotation axis 114). As explained above, according to one embodiment, an oscillating movement is superimposed on the respective cleaning position in order to achieve cleaning in the transverse direction 138 over an extent that is greater than the extent of a laser spot generated by the laser radiation 106 on the surface 108 to be cleaned second cleaning position 146, the beam path 110 oscillates between a first end position 148 and a second end position 150. According to one embodiment, in the first cleaning position 144 a first part 152 of the surface to be cleaned 108 is cleaned and in the second cleaning position 146 a second part 154 of the to cleaning surface 108 cleaned. According to one embodiment, the first part 152 and the second part 154 of the surface to be cleaned 108 overlap, for example as in FIG 2 shown.

3 15 shows a mold segment assembly 156 in accordance with embodiments of the subject matter disclosed herein.

According to one embodiment, the mold segment assembly 156 consists of a plurality of mold segments, some of which are in 3 are marked with 102. According to one embodiment, the mold segment arrangement 156 is closed in the form of a ring, for example as in FIG 3 shown. According to another embodiment, the mold segment arrangement can be open, for example arranged in a semicircle. For a closed loop mold segment assembly 156, the rotation of the beam path about the axis of rotation is typically through an angle of 360 degrees (one full revolution) or more.

4 14 shows a cross-sectional view along line IV-IV of a single mold segment 102. FIG 3 .

It is noted that the cross-sectional shape of the mold segment 102 shown in 4 shown was chosen to illustrate some embodiments of the subject matter disclosed herein. Of course, other cross-sectional shapes can be selected according to other embodiments.

According to one embodiment, the mold segment 102 has a microstructure 158 . According to one embodiment, the microstructure 158 has a plurality of bumps, some of which are in 4 denoted by reference numeral 160. According to one embodiment, a distance 162 between the elevations 160 is in a range between 70 μm and 1 mm, for example approximately 500 μm.

According to a further embodiment, the mold segment 102 has at least one elevation 164 which defines part of a profile of a tread of the tire.

According to a further embodiment, the mold segment 102 has a depression 166 . For example, according to one embodiment, the indentation 166 may form a letter or symbol on the surface of the tire.

It is understood that the elevations 160, 164 in a tire molded from the mold segment 102 (in 4 not shown), wells are formed. Accordingly, a bump is formed on the tire by the indentation 166 in the tire mold.

According to one embodiment, a mold base 168 is formed between structural elements (ie, between elevations 160 , 164 and depressions 166 ) of mold segment 102 . The base of the form 168 can be defined, for example, by at least one profile segment 169, which defines a tread of the tire ned, and/or at least one side shell 171, which defines a tire sidewall, can be formed. For example, the mold base 168 can be formed by at least one profile segment 169 and at least one side shell 171, for example as in 4 shown. A profile segment 169 and a side shell 171 can be formed by individual (separate) mold segments according to one embodiment, or by a common mold segment according to another embodiment.

According to one embodiment, the mold segment arrangement (and thus each mold segment 102) defines a rotationally symmetrical surface 170 which, by definition, is closed in the form of a ring and is rotationally symmetrical with respect to an axis of symmetry 172. In particular, the depiction of the axis of symmetry 172 and the distance between the axis of symmetry 172 and the shaped segment 102 is not true to scale, but is merely intended to illustrate the relationship between the rotationally symmetrical surface 170 and the axis of symmetry 172 . According to one embodiment, the rotationally symmetrical surface 170 is an imaginary envelope surface which is rotationally symmetrical with respect to the axis of symmetry 172 and which is an envelope of the surface 108 to be cleaned, for example as in FIG 4 shown.

5 16 shows a portion of a mold segment 102 having a structural element in the form of a bump 160 and a position of a beam path 110 in accordance with embodiments of the subject matter disclosed herein.

In one embodiment, the jet path 110 reaches the surface to be cleaned 108 at an angle 174 of less than 60 degrees with respect to the normal 176 of the surface 108 . According to one embodiment, this applies to at least 90% of the part 152, 158 of the surface to be cleaned 108 that is reached by one of the cleaning positions 144, 146 (cf 2 ). It is noted that the surface of a structural element, for example the elevation 160, forms part of the surface to be cleaned 108, for example as in FIG 5 shown.

6 10 shows part of a mold segment 102. FIG 5 and another position of the beam path 110 according to embodiments of the subject matter disclosed herein.

According to one embodiment, the jet path 110 forms an angle 174 with the normal 176 of the surface to be cleaned 108 which is less than 30 degrees, for example less than 10 degrees, for example as in FIG 6 shown.

7 FIG. 12 schematically shows two laser spots 178 according to embodiments of the subject matter disclosed herein.

According to one embodiment, the two laser spots 178 are formed by laser radiation 106 propagating along a beam path 110 according to embodiments of the subject matter disclosed herein and impinging on the surface to be cleaned 108 at an intersection 112 of the beam path 110 with the surface to be cleaned 108 . It goes without saying that a single laser can only ever generate a single laser spot 178 at a time. In other words, according to an embodiment that works with a single laser spot, the laser spots 178, as shown in FIG 7 are shown, successively formed in time. According to one embodiment, the laser radiation 106 is a pulsed laser radiation. According to a further embodiment, each pulse (laser pulse) of the laser radiation 106 generates a laser spot 178.

According to one embodiment, successive laser pulses and thus also the laser spots 178 generated thereby overlap. The overlapping of the laser spots 178 generates an overlap region 180 to which each of the two pulses 178 is applied. The overlap of the laser spots 178 or the corresponding laser pulses is defined by the area of the overlapping region 180 divided by the total area of a laser spot 178. It is understood that, unless otherwise stated, the overlapping of laser spots or laser pulses is always spatial overlap.

It is noted that each entity disclosed herein (e.g. components, units and devices, in particular a cleaning device, a laser device, a control device or an actuator arrangement) is not limited to a dedicated entity as described in some embodiments. Rather, the subject matter described herein may be provided in various ways with various granularities at the device level or at the software module level while still providing the functionality indicated. Furthermore, it should be noted that according to embodiments, a separate entity (e.g., a software module, a hardware module, or a hybrid module) may be provided for each of the functions disclosed herein. According to other embodiments, an entity (e.g., a software module, a hardware module, or a hybrid module) may be configured to provide two or more functions as described herein. According to still other embodiments, two or more entities configured to collectively provide a function as described herein.

According to embodiments of the subject matter disclosed herein, any suitable entity (e.g., a controller) may be provided, at least in part, in the form of corresponding computer programs that enable a processor device to provide the functionality of the corresponding entity as described herein. According to other embodiments, any suitable entity as described herein may be provided in hardware. According to other hybrid embodiments, some entities may be provided in software while other entities are provided in hardware.

According to one embodiment, the control device contains a processor device, which has at least one processor for executing at least one computer program, which corresponds to a corresponding software module.

A definition of an optical arrangement or an optical geometry with reference to a laser radiation can of course also be defined analogously with reference to a beam path of the laser radiation, and vice versa. In this respect, any reference herein to a beam path analogously discloses a reference to laser radiation. It is understood here that the laser radiation is electromagnetic radiation and that the beam path, i. H. the path along which the laser radiation propagates is defined by suitable optical components.

It is pointed out that the embodiments described here merely represent a limited selection of possible embodiment variants of the present disclosure. It is thus possible to combine the features of different embodiments with one another in a suitable manner, so that, in addition to the combinations of embodiments explicitly described here, as described, for example, with reference to the drawings, a large number of different embodiments are to be regarded as disclosed for the person skilled in the art . It should also be noted that terms such as "a" or "an" do not exclude the plural. Terms such as "containing" or "having" do not exclude other features or process steps. Thus, according to one embodiment, the term "comprising" or "including" means "comprising, inter alia". According to a further embodiment, the term "comprising" or "including" stands for "consisting of". According to one embodiment, the term "configured for" includes the meaning "configured to," among other things.

It should also be noted that any reference signs in the claims should not be construed as limiting the scope of the claims. Furthermore, it should be noted that any reference signs in the description and the description's reference to the drawings should not be construed as limiting the scope of the description. Rather, the drawings illustrate only one example implementation of a particular combination of multiple embodiments of the subject matter disclosed herein, any other combination of embodiments being equally possible and contemplated as disclosed with this application.

In summary, it remains to be stated:

Method for cleaning at least one mold segment of a tire mold by means of laser radiation, wherein the at least one mold segment has at least part of a surface to be cleaned; wherein a beam path of the laser radiation defines an intersection with the surface to be cleaned; and wherein the jet path is rotatable about an axis of rotation to thereby move the point of intersection across the surface to be cleaned; the method comprising aligning the axis of rotation of the jet path with respect to the at least one mold segment, positioning the jet path with respect to the axis of rotation in a first cleaning position, the first cleaning position defining at least the following on an average over time: (i) a first angle between the jet path and a plane perpendicular to the axis of rotation, (ii) a distance between a line along the beam path and the axis of rotation, and (iii) a position on the axis of rotation that is a minimum distance from the line along the beam path; the method further comprising guiding the jet path in the first cleaning position over an angular range of at least 20° over the surface to be cleaned by rotating the jet path about the axis of rotation.

QUOTES INCLUDED IN DESCRIPTION

This list of the 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 102013220066 B3 [0002]

Claims (21)

Method for cleaning at least one mold segment (102) of a tire mold using laser radiation (106), a. wherein the at least one mold segment (102) includes at least a portion of a surface (108) to be cleaned; b. wherein a beam path (110) of the laser radiation (106) defines an intersection (112) with the surface (108) to be cleaned; and c. the jet path (110) being rotatable about an axis of rotation (114) to thereby move the point of intersection (112) across the surface (108) to be cleaned; having the procedure i.e. aligning the axis of rotation (114) of the beam path (110) with respect to the at least one mold segment (102), e. positioning the beam path (110) with respect to the axis of rotation (114) in a first cleaning position (118), the first cleaning position (118) defining at least the following on a time average: i. a first angle (119) between the beam path (110) and a plane (123) perpendicular to the axis of rotation (114), ii. a distance between a straight line along the beam path (110) and the axis of rotation (114) and iii. a position on the axis of rotation (114) that is a minimum distance from the straight line along the beam path (110); f. guiding the jet path (110) in the first cleaning position (118) over an angular range of at least 20° over the surface (108) to be cleaned by rotating the jet path (110) about the axis of rotation (114). procedure after claim 1 , wherein during the rotation of the beam path (110) in a direction of rotation, the beam path (110) is guided back and forth transversely to the direction of rotation, in particular wherein the time average extends over several back and forth movements and the first cleaning position (118) is an average position averaged over the reciprocating motions. procedure after claim 1 or 2 wherein the jet path (110) is placed in a second cleaning position; and wherein the jet path (110) is again rotated about the axis of rotation (114) in the second cleaning position; in particular wherein a first part of the surface to be cleaned (108) is cleaned by rotating the jet path (110) in the first cleaning position (118) and wherein a second part of the surface to be cleaned is cleaned by rotating the jet path (110) in the second cleaning position (108) is cleaned. procedure after claim 3 , wherein the first part of the surface to be cleaned (108) and the second part of the surface to be cleaned (108) are at least partially different from each other. procedure after claim 3 or 4 , wherein the first part of the surface to be cleaned (108) and the second part of the surface to be cleaned (108) at least partially overlap. Method according to one of claims 3 until 5 wherein the at least one mold segment (102) can be introduced into a mold segment arrangement, in which the at least one mold segment (102) forms at least part of the mold segment arrangement; wherein the mold segment arrangement defines a rotationally symmetrical surface (170) which is annularly closed and rotationally symmetrical with respect to an axis of symmetry (172); and wherein the first cleaning position (118) and the second cleaning position differ in the time average in at least one of the following parameters i. a first angle which a direction vector of the beam path (110) encloses in the time average with the plane (123) perpendicular to the axis of rotation (114), ii. a second angle which the beam path (110) encloses in the time average with the rotationally symmetrical surface (170), iii. a distance of a focal point of the beam path (110) from the rotationally symmetrical surface (170), iv. a distance of an intersection point of the beam path (110) and the rotationally symmetrical surface (170) from the axis of rotation (114); v. the distance of the straight line along the beam path (110) from the axis of rotation (114). Method according to any one of the preceding claims, wherein in the first cleaning position (118) a third angle which a projection of the jet path (110) encloses in a plane which is perpendicular to the axis of rotation (114) with a radial direction is less than 30 degree is. Method according to any of claims 3 until 7 , wherein the surface (108) to be cleaned is cleaned in that the jet path (110) is brought into a plurality of cleaning positions (118) and the jet path (110) is rotated about the axis of rotation (114) in each cleaning position (118), wherein the plurality of cleaning positions includes the first cleaning position (118) and the second cleaning position; and in particular wherein at least 90% of the surface to be cleaned (108) in at least one of Cleaning positions of the plurality of cleaning positions is reached by the beam path (110) of the laser at an angle of less than 60 degrees with the normal (176) of the surface (108) to be cleaned. procedure according to claim 8 , wherein all cleaning positions of the plurality of cleaning positions are chosen such that the number of cleaning positions is minimized. A method according to any one of the preceding claims, wherein the laser radiation (106) has at least one of the following laser parameters: (i) a fluence in a range between 1 J/cm ² to 5 J/cm ² ; (ii) a wavelength in a range between 0.5 µm and 10 µm; (iii) a pulse frequency in a range between 0.1 kHz and 100 kHz; (iv) a pulse duration in a range between 0.5 ns to 5 µs; (v) a pulse overlap in a range between 0% and 99%, in particular 40-80%; (vi) a Rayleigh length in a range between 10 mm and 200 mm. A method according to any one of the preceding claims, further comprising at least one of the following features: (i) suction adjacent the intersection (112) of the jet path (110) with the surface (108) to be cleaned; (ii) automatically performing an alignment of the axis of rotation (114) and the at least one mold segment (102); (iii) the positioning of the beam path (110) in the first cleaning position (118) takes place via at least five mechanical axes and in particular an optical axis; (iv) the characteristics of claim 6 and furthermore automatic implementation of an aligned alignment of the axis of rotation (114) and the axis of symmetry (172) of the rotationally symmetrical surface (170), the automatic implementation having a determination of the axis of symmetry (172) by means of a laser distance measurement of the segment arrangement from the axis of rotation (114). A method according to any one of the preceding claims, wherein of the at least one mold segment (102) at least one mold segment (102) includes at least one spring mechanism vent valve. procedure according to claim 12 , wherein a fluence of the laser radiation (106) is reduced and an irradiation time is increased in order to clean the at least one vent valve. Method according to any one of the preceding claims, wherein of the at least one mold segment (102) at least one mold segment (102) has a microstructure (158), in particular a) wherein the microstructure (158) has structure sizes in a range between 20 µm and 1 mm, in particular in a range between 70 µm and 300 µm; and or b) the microstructure (158) i.) has an aspect ratio which is greater than 0.5, in particular greater than 0.8, the aspect ratio being defined as the extent h of a structural element of the microstructure perpendicular to the imaginary mold base divided by the smallest extent b of the structural element in the imaginary mold footprint; or ii.) has a surface whose area is more than twice, in particular more than three times, the area of a section of the imaginary mold base area over which the microstructure extends. procedure according to Claim 14 wherein at least one mold segment (102) of the at least one mold segment (102) having a microstructure (158) defines a side shell of the tire mold intended for molding a sidewall of a tire. Method according to any of Claims 14 or 15 , wherein a fluence of the laser radiation (106) is reduced and an irradiation time is increased in order to clean the microstructure (158). A method according to any one of the preceding claims, wherein the beam path (110) is rotated multiple times through the angular range in the first cleaning position (118). Cleaning device (100) for cleaning at least one mold segment (102) of a tire mold by means of laser radiation (106), the at least one mold segment (102) having at least part of a surface (108) to be cleaned; the cleaning device (100) comprising: a) a beam path (110) along which the laser radiation (106) propagates and which defines an intersection point (112) with the surface (108) to be cleaned; b) an axis of rotation (114) about which the jet path (110) is rotatable to thereby move the point of intersection (112) across the surface (108) to be cleaned; c) a first actuator assembly (128) for aligning the axis of rotation (114) of the beam path (110) with respect to the at least one mold segment (102); d) a second actuator arrangement (116) for positioning the beam path (110) with respect to the axis of rotation (114) in a first cleaning position (118), wherein the first cleaning position (118) defines, on an average over time, at least the following: i. a first angle (119) between the beam path (110) and a plane (123) perpendicular to the axis of rotation (114), ii. a distance between a straight line along the beam path and the axis of rotation, and iii. a position on the axis of rotation (114) that is a minimum distance from the straight line along the beam path (110); e) a third actuator arrangement (124) for guiding the jet path (110) in the first cleaning position (118) over an angular range of at least 20° over the surface (108) to be cleaned by rotating the jet path (110) about the axis of rotation (114) . Cleaning device (100) according to Claim 18 , wherein at least one actuator from one of the first actuator arrangement (128), the second actuator arrangement (116) and the third actuator arrangement (124) is also part of a further one of the first actuator arrangement (128), the second actuator arrangement (116) and the third actuator arrangement (128) is. Control device (101) for controlling a cleaning device, wherein the control device (101) is set up to carry out the method according to any one of Claims 1 until 17 to perform. Computer program product comprising a program element, wherein the program element is set up, when it is executed on a processor device (105), a method according to any one of Claims 1 until 17 to perform.

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