JP2024511694A - Card wire laser curing method - Google Patents

Abstract

The present invention relates to a laser beam curing method for a section A of a card wire 10 to be hardened. This causes the card wire 10 to move through the work space 26 in the transport direction. An inert gas atmosphere is created in the work space 26 by introducing inert gas G continuously or discontinuously. A laser beam region 27 is formed within the working space 26, in which the section A to be cured of the card wire 10 moves. As a result, the hardening target section A is heated. After exiting the laser beam region 27, the section A to be cured is cooled and cured by advancing this temperature profile. Curing in an inert gas atmosphere in the working space 26 avoids the formation of oxide layers (scaling) and tempering colors.

Description

The present invention relates to a method for laser curing a section of a card wire to be hardened.

Laser curing methods are known, for example, from DE 10 2005 200 2013. There, a laser beam is directed through an opening into a working space through which the card wire is moved in the conveying direction. The card wire is preheated by a gas burner in the transport direction in front of the working space. Behind the working space in the transport direction, the card wire is cooled by a spray nozzle. The inside of the workspace is spherical, and the laser beam reflected from the card wire can be reflected back to the card wire from inside the workspace. In this way, laser light can be directed onto the card wire from two opposite sides.

A laser curing method for card wire is also described in Patent Document 2.

US Pat. No. 5,001,300 describes hardening of card wires by induction heating and subsequent cooling by a cooling medium. This document states that laser curing lacks advantages because localized overheating can occur due to the energy of the laser beam. Induction heating of card wires is also known from US Pat.

US Pat. No. 5,202,302 describes a method for hardening workpieces or tools, such as bandsaws, by means of an electron beam, the electron beam energy being adapted to the shape and/or position of the section to be hardened.

The use of lasers for laser beam cutting is known from US Pat. This makes it possible, for example, to cut the contour of a card wire from a workpiece.

The card wire has a base on which the card wire is wound around a roller. The teeth have a generally triangular profile and protrude from the base. In the direction of extension of the card wire or base, two immediately adjacent teeth are separated from each other by a gap.

During carding, textile fibers are taken out by a card wire wound around a roller and directed circumferentially around the roller in the gaps between adjacent windings of the card wire. Thereby, the card wire teeth are configured to pick up the textile fibers and hold the textile fibers until they are released. Therefore, it is desirable to provide these teeth with sufficient hardness so that excessive wear due to friction with the textile fibers does not occur. The bases of the card wires must each have elasticity, as they must be wound around the rollers in turn. Therefore, during the manufacture of carded wire for all-steel clothing, it is desirable that the carded wire has different hardness in different regions.

Therefore, at least the section to be hardened of each tooth of the card wire must be hardened, while the base has a lower hardness compared to the section to be hardened. This creates a transition region between the already cured part and the uncured part. In the transition region, the hardness of the card wire is not precisely defined, which can be a drawback of the card wire or each tooth of the card wire. It is also disadvantageous that metal oxide layers can be formed by heating (scaling). It is then generally necessary to remove the ionic oxide layer again in a further process.

U.S. Patent No. 4,924,062 Swiss Patent No. 670455 German Patent Application No. 102014106574 Japanese Patent No. 2909774 German Patent No. 2018793 German Patent Application No. 102006030418

It is therefore an object of the present invention to provide a method by which card wires can be cured efficiently using space-saving equipment while avoiding scale formation.

This object is achieved by a method having the features of claim 1.

In the present invention, a laser is used to cure the card wire in the section of the card wire to be cured. The card wire has a continuous base with protruding teeth. If the base extends linearly in the direction of extension, the teeth are oriented parallel to a common plane and arranged in rows in the direction of extension. This method includes the following steps.

At least one laser beam area is formed in the working space on at least one working surface. exactly one laser beam area is formed in one working plane, or a first laser beam area is formed in a first working plane and a second laser beam area is formed in a second working plane. Preferably, it is formed. This places the work surfaces at a distance from each other. The laser beam area can be formed by a cross section of a continuous laser beam. The contour of the laser beam area may vary, for example it may be polygonal, in particular rectangular. Advantageously, the laser beam region comprises at least one, preferably four, linearly extending outer edges. At each straight edge, the intensity of the laser light or the energy density of the laser beam area changes rapidly. The rate of change m represents the gradient of the laser light intensity at the outer edge of the laser beam region, and can be defined, for example, as follows.

ここで、
ｍ：強度の変化率

：レーザービーム領域の強度Ｉの平均値
ｗ：平均強度

の５０％で直線外縁に直交するレーザービーム領域の幅
ｘ１：平均強度

の１０％で直線外縁に直交するレーザービーム領域の幅の半分
ｘ２：平均強度

の９０％で直線外縁に直交するレーザービーム領域の幅の半分。

here,
m: rate of change in intensity

: Average value of intensity I in laser beam area w: Average intensity

Width of the laser beam area perpendicular to the outer edge of the straight line at 50% x1: Average intensity

Half the width of the laser beam area perpendicular to the outer edge of the straight line at 10% x2: Average intensity

half the width of the laser beam area perpendicular to the straight outer edge at 90% of

The rate of change is preferably greater than 5, particularly preferably greater than 7, and even more preferably greater than 8.

Inert gas is introduced into the work space. This inert gas introduction can be carried out continuously or discontinuously. In this way, an inert gas atmosphere can be created within the working space. For example, nitrogen and/or argon and/or other noble gases can be used as inert gases. In doing so, an inert and/or less chemically reactive atmosphere is created in the workspace.

The card wire is transported in the transport direction, in particular in the direction of extension of the card wire into the working space. Therefore, the hardening target section of each tooth of the card wire is preferably oriented obliquely or perpendicularly to the laser beam emission direction within the working space. The card wire is conveyed in such a way that each section to be cured moves along or through at least one laser beam region. Each section to be cured has at least one outer surface along each working surface that moves during movement of the section to be cured through the at least one assigned laser beam field. For example, one single laser beam field can be formed in one single working plane, and the outer surface of each section to be cured moves along the working plane through the laser beam field. It is also possible to form two laser beam regions in two working planes which are arranged parallel to each other and separated in a direction perpendicular to the transport direction corresponding to the thickness of the section to be cured. Thereby, the two opposing outer surfaces of each section to be cured can be moved along one of the two working surfaces in each case via the assigned laser beam area. Each section to be cured can thus be heated from one side by a laser beam region or from opposite sides by two laser beam regions.

While the section to be cured is moving through the at least one laser beam region, it is heated. Due to the transport movement of the card wire, the section to be cured moves away from the at least one laser beam region, so that no additional energy or heat is introduced into the section to be cured. Due to the heat conduction of the material of the card wire and between the card wire and the surrounding atmosphere in the working space, the section to be heated is rapidly cooled, thus increasing its hardness. A gas flow is generated by supplying an inert gas, optionally providing an additional cooling effect. In this case, inert gas can be continuously introduced into the working space. A separate supply of additional cooling medium is not necessary in all embodiments. Heating and cooling of each section of card wire to be cured takes place entirely within the working space.

Therefore, the introduction of energy and heating of each section to be cured by the laser beam region can be performed within a small region. Heating and cooling take place in a very short period of time, so the risk of scaling is already reduced. However, it has been shown that despite this short period of curing, temper color formation and/or scaling can occur. According to the invention, for this reason an inert gas is introduced continuously or discontinuously into the interior of the working space, so that a low-reactivity or inert atmosphere is created. By doing so, the laser curing is further improved and post-treatment of the card wire curing section can be omitted.

For the generation of the laser light or laser beam, a laser beam source such as a diode laser or a gas laser is used, for example. The wavelength of the laser light may be a light wavelength of at least 650 nm, such as in the range of 800 nm-1400 nm, and in one embodiment about 1000 nm.

Preferably, the card wire moves continuously in the transport direction without stopping. Movement in the transport direction can be performed at a constant speed. The speed at which the card wire moves in the conveying direction can be at least 10 m/min or 20 m/min, for example 40 m/min-50 m/min, and the speed can be adjusted depending on the dimensions of the teeth in the conveying direction. can. Since the speed during the movement of the card wire in the transport direction is constant, the period during which each section to be cured travels through the at least one laser beam region is also constant.

If at least one property of the laser beam area is time-invariant, for example the contour of the laser beam area and/or the intensity of the laser light and/or the beam impulse frequency during the on-period of the laser, the laser beam area is If formed, there is an advantage. In one embodiment, the laser beam region is not switched on or off, and the energy density of the laser light does not change in a time-dependent manner over the range of the laser beam region (eg, the laser beam impulse frequency is zero). Preferably, the spatial extension of the laser beam area and the position of the laser beam area in the working space are constant.

In preferred embodiments, at least one laser beam region may have a non-circular contour. The at least one laser beam area has its length in the conveying direction and its width in the direction perpendicular to the conveying direction in the assigned working plane. Length and width are particularly different, and width may be shorter than length. The length of the at least one laser beam region may range from a minimum of 10 mm to a maximum of 100 mm, preferably from 15 mm to 70 mm, more preferably from 25 mm or from 30 mm to 40 mm. For example, the length of the laser beam area is 32mm-35mm. The width of the laser beam area can be selected depending on the height of the section to be hardened on each tooth, and in one embodiment is at least 0.5 mm or 1.0 mm and/or at most 2.0 mm or 3.0 mm. I can do it.

In a preferred embodiment, each laser beam region can be formed by a respective beam shaping optic that turns an input laser beam into an output laser beam. The outgoing laser beam has a different cross section than the incoming laser beam. The output laser beam forms a laser beam area on the assigned working surface. If a first laser beam area in the first working plane and a second laser beam area in the second working plane are formed, two separate beam shaping optics can be used for this purpose. The beam-forming optics may, for example, comprise a lens, in particular a free-form lens similar to a Powell lens. In addition to such lenses, the beam-forming optics may include additional light-constricting and/or light-refractive and/or light-reflecting components.

It is a further advantage if the laser light that passes through the laser beam region without impinging on the section to be cured is at least partially received by the beam dump. When the card wire moves in the conveying direction, for example, the laser light partially passes through the laser beam region, for example through a region where a gap exists between two adjacent teeth of the card wire in the laser beam region. This laser light can be at least partially captured by a beam dump. For this purpose, the beam dump can be arranged opposite the beam-forming optics, eg the working surface is between the beam-forming optics and the beam dump.

Preferably, the beam dump can be cooled by a cooling medium, for example water and/or air. Inside the beam dump, at least one cooling channel can be extended for this purpose, through which a cooling medium flows. Additionally or alternatively, the cooling medium can be directed to the beam dump from outside.

In one aspect, the beam dump can include at least one entrance surface oriented obliquely to the direction of travel of the laser light passing through the at least one laser beam region. By doing so, the energy density of the laser beam on the incident surface becomes smaller than the energy density in the laser beam region. The energy density of the laser light can be reduced such that heating on the entrance surface is not important for beam dumping and the heat thereby introduced can be dissipated by active cooling, preferably by a cooling medium. .

The duration of application of the laser light to each point of the section to be cured in at least one laser beam region may be at most 150 ms or at most 100 ms. Preferably, the application period may be in the range 30 ms-90 ms, more preferably in the range 50 ms-70 ms. In one embodiment, the application period is about 60 milliseconds. The application period can be adjusted, for example, according to the transport speed of the card wire and/or the length of the at least one laser beam region in the transport direction.

Preferably, the card wire is tempered before entering the at least one laser beam region. The tempering can be limited to the base of the card wire or at least cover it. Further, the entire card wire can be subjected to a tempering treatment. Tempering includes the steps of warming up from an initial temperature to a holding temperature, complete heating at the holding temperature, and cooling to a target temperature that may correspond to the initial temperature of the card wire before warming up. The target temperature and/or the initial temperature may be, for example, the environmental temperature.

It is also advantageous if the method comprises a step of cleaning the card wire before passing into the at least one laser beam region. Cleaning may be performed before any tempering process. Cleaning is carried out in particular without direct contact between the cleaning tool and the card wire, for example by spraying the card wire with a cleaning liquid. Water may be used as a cleaning fluid.

It is advantageous if the warming-up of at least one section to be cured is measured, for example by a pyrometer. In this way, the energy density of the laser light in at least one laser beam region can be adjusted such that a desired temperature in the section of the card wire to be cured is achieved. By measuring the temperature in the section to be cured, a closed-loop control or regulation of the laser energy and thus also the energy density of the laser light in the at least one laser beam region can be realized.

Advantageous embodiments of the invention emerge from the dependent claims, the detailed description and the drawings. In the following, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings. The diagram is as follows.

1 is a partial schematic perspective view of an embodiment of a card wire; FIG. 2 is a partial schematic side view of the card wire of FIG. 1; FIG. FIG. 3 is a cross-sectional view taken along cutting line III-III in FIG. 2 and showing a plane perpendicular to the extending direction of the card wire. 4 is a basic schematic illustration of the hardness progression of already hardened teeth of the card wire of FIGS. 1 to 3; FIG. FIG. 2 is a basic schematic diagram of a card wire curing device and a curing method as seen from the transport direction. 6 is a schematic view of the apparatus and method of FIG. 5 in a side perpendicular to the transport direction; FIG. FIG. 2 is a basic diagram of the laser beam area of the present invention, in which the length direction is the transport direction and the width direction is perpendicular to the transport direction. 1 is a highly schematic illustration of a variant embodiment of a card wire laser curing device and method; FIG.

The present invention relates to laser curing of card wire 10 and is illustrated schematically in FIGS. 1-3. The card wire 10 includes a base portion 11 extending in the longitudinal direction L. The cross section of the base 11 may be polygonal, for example rectangular. In the width direction B, a plurality of teeth 12 alternately arranged in the longitudinal direction L protrude from the base 11. One gap 13 exists between two teeth 12 that are immediately adjacent in the longitudinal direction L. Each tooth 12 has a substantially triangular profile with a corner 14 located apart from the base 11 in the width direction B. The corner 14 is formed by two edges 15, 16 which define the contour of the tooth 12. In the embodiment, one first edge 15 extends substantially in the width direction B, and the other second edge 16 extends obliquely with respect to the width direction B.

In the depth direction T perpendicular to the width direction B and the longitudinal direction L, the base 11 has a thickness or strength at least in a section longer than the thickness of the teeth 12. Accordingly, in the embodiment, a protrusion is formed on the base 11 having the longitudinal surface 17 oriented perpendicularly to the width direction B. Each tooth 12 has a first outer surface 18 and a second outer surface 19 opposite the first outer surface 18 . The two outer surfaces 18, 19 are arranged at a distance from each other in the depth direction T depending on the thickness of the tooth 12. The two outer surfaces 18, 19 can be arranged parallel to each other. In the embodiment, the second outer surface 19 extends substantially orthogonally to the depth direction T, whereas the first outer surface 18 is inclined obliquely with respect to the depth direction T and the second outer surface 19. suitable for The first outer surface 18 extends in a first surface E1 and the second outer surface 19 extends in a second surface E2 (FIG. 3).

The hardening target section A is adjacent to the corner 14 of each tooth. In this section, each tooth 12 is hardened. The hardening target section A is arranged at a distance from the protrusion of the base 11 adjacent to the longitudinal surface 17 . After the section A to be cured is cured by the laser curing of the present invention, the transition region Z is adjacent to the section A to be cured whose hardness continuously decreases toward the base 11 . In the width direction B, the transition zone Z has dimensions in the range of less than 0.3 mm, preferably less than 0.2 mm after laser hardening according to the method of the invention.

In order to cure the section A to be cured, energy is introduced into the section A to be cured and heated. Heating of the section A to be cured is performed by radiation from a laser beam. An example of a laser curing device and a laser curing method is shown in block diagram schematic diagrams in FIGS. 5 and 6, respectively.

A working space 26 is defined within the housing 25 for laser curing. In this working space 26, the card wire 10 is processed in the section A to be hardened, in particular laser hardening. In the embodiment, the card wire 10 is moved in the transport direction F through the work space 26 by a transport device (not shown). The transport direction F can be, for example, a horizontal direction. When the card wire 10 is transported in the transport direction F, it is preferable that the card wire 10 is oriented such that the longitudinal direction L is directed toward the transport direction. The width direction B of the card wire 10 is preferably oriented parallel to the transverse direction Q of the work space 26 orthogonal to the conveying direction F. The conveying direction F and the transverse direction Q can form horizontally extending surfaces. The card wire 10 can be moved in the work space in a so-called lying position.

In the presently preferred embodiment, the card wire 10 is continuously moved through the working space 26 and is thereby treated, in particular hardened. The speed at which the card wire 10 moves in the conveying direction F is preferably constant, in embodiments at least 10 m/min or at least 20 m/min, for example 40 m/min-50 m/min, where the speed is The larger the tooth 12, the lower.

At least one laser beam area 27 and, in the embodiment according to FIGS. 5 and 6, exactly one laser beam area 27 is formed in the working space. For this purpose, the device comprises a laser beam source 28 which emits a laser beam 29 . The emitted laser beam 29 can be fed directly to the beam shaping optics 31 as an incident laser beam 30 or alternatively indirectly via one or more optical elements. The optical element can redirect and/or refract and/or diffract and/or reflect the laser beam and then provide it as an input laser beam 30 to a beam-forming optics 31 .

The laser light of the laser beam 29 produced by the laser beam source 28 preferably comprises a wavelength of at least 650 nm or at least 800 nm, for example in the range 800 nm-1400 nm, in an embodiment about 1000 nm.

Beam-forming optics 31 are configured to form an input laser beam 30 and an output laser beam 32 therefrom, and have a defined cross-section at the working plane. To this end, the beam-forming optics 31 may comprise one or more optical components, such as lenses, in particular free-form lenses 33 .

At the working surface inside the working space 26 the output laser beam 32 forms a laser beam region 27 . In the embodiment according to FIGS. 5 and 6, the working surface extends inside the working space 26 in the conveying direction F and the transverse direction Q, or is inclined in the transverse direction Q, and extends from the first outer surface 18 present in the working space. A first surface E1 is substantially located within the working surface. The output laser beam 32 has defined dimensions and energy density in its laser beam region 27 located in the working plane. As shown very schematically in FIG. 7, the laser beam area 27 has a length x in the conveying direction F and a width y in the direction Q perpendicular to, or transverse to, the conveying direction F along the working surface. The length x is different from the width y, and is preferably longer than the width y. In embodiments, the length x may be a minimum of 10 mm to a maximum of 100 mm, preferably 15 mm to 70 mm, more preferably 25 mm or 30 mm to 40 mm, especially 32 mm to 35 mm. The width y of the laser beam area 27 can be adapted to the dimensions of the section A of the tooth 12 to be hardened and can, for example, be a minimum of 0.5 mm or in the range from 1.0 mm to 2.0 mm or 3.0 mm. .

At least one laser beam region 27 has a rectangular or otherwise polygonal contour according to the embodiment. At least it comprises a straight outer edge oriented parallel to the transport direction F and delimiting at least one laser beam area 27 towards the base 11 . At each straight edge, the intensity of the laser light or the energy density of the at least one laser beam region 27 changes abruptly. The rate of change m represents the gradient of the laser light intensity at the outer edge of the laser beam region, and is, for example, as follows.

ここで、
ｍ：強度の変化率

：レーザービーム領域の強度Ｉの平均値
ｗ：平均強度

の５０％で直線外縁に直交するレーザービーム領域の幅
ｘ１：平均強度

の１０％で直線外縁に直交するレーザービーム領域の幅の半分
ｘ２：平均強度

の９０％で直線外縁に直交するレーザービーム領域の幅の半分。

here,
m: rate of change in intensity

: Average value of intensity I in laser beam area w: Average intensity

Width of the laser beam area perpendicular to the outer edge of the straight line at 50% x1: Average intensity

Half the width of the laser beam area perpendicular to the outer edge of the straight line at 10% x2: Average intensity

Half the width of the laser beam area perpendicular to the straight outer edge at 90% of

The rate of change is preferably greater than 5, particularly preferably greater than 7, and even more preferably greater than 8.

A low-reactivity or inert gas atmosphere is created within the working space 26 to avoid the formation of metal oxide layers (scale) and the production of tempering colors due to laser hardening. For this purpose, an inert gas G is introduced into the working space 26. For this purpose, the housing 25 can be provided with at least one gas connection 37 for supplying an inert gas G. The inert gas G can be flowed into the working space 26 continuously or discontinuously.

The inert gas G is introduced into the working space 26 adjacent to the beam forming optics 31 and flows obliquely or perpendicularly to the traveling direction of the output laser beam 32, for example in the transverse direction Q and/or in the transport direction F. It is preferable to do so. In an embodiment, the inert gas G is introduced vertically between the working surface or laser beam region 27 and the beam shaping optics 31 . The flow of inert gas G can protect the beam forming optics 31 and act as a sealing gas for so-called fumes and/or vapors generated during laser curing and/or other processes in the working space 26. can. The inert gas G may remove fumes and/or vapors from the laser beam region 27. Therefore, the inert gas G not only contributes to the creation of a less reactive or inert atmosphere in the working space 26 according to the embodiment, but also at the same time protects the beam shaping optics 31 and/or the laser beam on the surface of the card wire 10. It serves to maintain as uniform an energy density in region 27 as possible.

As the inert gas G, nitrogen, argon or other noble gases or any combination thereof can be used.

For laser hardening, the card wire 10 is moved through the working space 26 and the section A of the individual tooth 12 to be hardened is subsequently moved through the laser beam region 27 . During this movement, the section A to be hardened is heated in the laser beam region 27 and is rapidly cooled after leaving the laser beam region 27, thus increasing its hardness. This cooling is performed by conducting the heat within the card wire 10 in the direction from the heated section to be cured toward the base 11. Additional cooling can be achieved by heat dissipation in the atmosphere within the workspace 26. The gas flow brought about by the introduction of inert gas G into the interior of the working space 26 can contribute to further cooling of the heated section.

As schematically shown in FIG. 7, the laser beam region 27 is positioned such that only the section A of the tooth 12 to be hardened moves through the laser beam region 27. Other sections of the card wire 10 that are not to be cured, in particular the base 11, are moved out of the laser beam region 27 through the working space 26.

In the embodiment, the application period during which the laser light of the emitted laser beam 32 in the laser beam region 27 acts on each point of the section A to be cured passing therethrough is a maximum of 150 ms or a maximum of 100 ms. Preferably, the application period may be in the range 30 ms-90 ms, more preferably in the range 50 ms-70 ms. In an example, the application period is about 60 milliseconds.

After hardening of the hardening target section A of the tooth 12, the hardness of the tooth 12 basically progresses as schematically shown in FIG. The abscissa in the figure defines the distance d in the width direction B from the corner 14 of the tooth 12. The vertical axis indicates hardness H based on distance d. The hardness H after curing is maximum and substantially constant in each hardening target section A. In the transition region Z, the hardness decreases. Outside the hardened part A, the hardness H corresponds to the value of the unhardened material of the card wire 10. The dimension of the transition region Z in the width direction B is preferably small, less than 0.2 mm. The uncured base 11 provides sufficient elasticity and deformability so that the card wire 10 can also be rolled onto a roller after curing without any problems without cracking or other damage.

As shown in FIGS. 5 and 6, a beam dump 38 may be present in the direction of travel of the output laser beam 32 behind the work surface or surface where the card wire 10 moves through the work space 26. The beam dump 38 is configured to at least partially capture the laser light of the outgoing laser beam 32 that does not impinge on the card wire 10 but passes through the laser beam region 27 , in particular the gap 13 between the two teeth 12 (Also compare Figure 7). The beam dump 38 has at least one entrance surface 39, two entrance surfaces 39 in the embodiment, which are arranged obliquely to the traveling direction of the laser light of the output laser beam 32. The entrance surface 39 can be arranged in a V-shape, for example. Due to the inclination of the entrance surface 39 with respect to the traveling direction of the laser beam, the area where the laser beam collides with at least one entrance surface 39 is expanded compared to the area of the laser beam region 27. Therefore, the energy density of the laser light impinging on at least one entrance surface 39 is reduced. Therefore, the absorption per unit area of the beam dump 38 is also sufficiently low.

In this embodiment, at least one entrance surface 39 is realized by the outer surface of the heat sink 40 . The heat sink 40 and therefore the at least one entrance surface 39 can be cooled by a cooling medium K, for example air, water or another fluid. For this purpose, at least one cooling channel 41 can be present inside the heat sink 40 in such a way that a cooling medium K flows through it. The cooling circuit for the cooling medium K is only shown very schematically in FIG.

Based on FIG. 6, any additional configuration possibilities are indicated for implementing the method or for configuring the device. An additional station for processing the card wire 10 may be located inside the housing 25, which is preferably arranged in front of the laser beam region 27 in the direction of movement of the card wire 10. For example, it can be a cleaning station or a tempering station 42. The cleaning station 41 is configured to clean at least the section A of the card wire 10 to be cured. The tempering station 42 is configured to temper at least the base 11 of the card wire 10.

The cleaning station 41 may be configured to output a cleaning substance and spray it onto the section A to be cured of the card wire 10 to remove dirt. Optionally, the card wire 10 can subsequently be dried in a cleaning station 41, for example by blow drying with gas.

The tempering station 42 is configured to temper at least the base 11 of the card wire 10 or the entire card wire 10. For this purpose, the tempering station 42 can be equipped with a heating device 43, a cooling device 44 and, optionally, a drying device 45. The heating device 43 serves to introduce at least heat into the base 11 of the card wire 10 and heat it to a holding temperature. Subsequently, the portion of the card wire 10 heated in this way is cooled by a cooling device 44, for example by spraying a cooling substance such as water. Subsequently, the card wire 10 can be dried by the drying device 45, for example, by blow drying using gas.

After cleaning in the cleaning station 41 and/or tempering in the tempering station 42, the section A to be hardened is hardened in the working space by laser hardening. In some embodiments, all of these processing steps occur within workspace 26.

FIG. 8 shows a further embodiment for laser hardening of the section A of the card wire 10 to be hardened, as a highly simplified schematic basic illustration. In this example, the two output laser beams 32 are generated by two separate beam-forming optics 31 which in each case form a laser beam area, in the example a first laser beam in a first working plane. A beam region 27a and a second laser beam region 27b in a second working surface arranged at a distance therefrom are formed. The two working surfaces can extend parallel or oblique to each other and are oriented according to the embodiment, such that the first surface E1 of the section to be cured A moves along the first working surface, and the section to be cured The second surface E2 of A is moved along the second working surface. In this arrangement, the energy of the laser light is applied to the section A of the card wire 10 to be cured on two opposite sides, namely the first outer surface 18 of the first laser beam region 27a and the second outer surface of the second laser beam region 27b. It can be introduced from the outer surface 19 of.

In the transport direction F, the laser beam regions 27a, 27b may be arranged offset from each other or may alternately overlap at least partially.

As further shown in FIG. 8, the two output laser beams 32 can be provided with two separate beam dumps 38. The output laser beams 32 are not oriented parallel to a common axis, but their directions of travel are oriented at an angle of less than 180° to each other.

The output laser beam 29 of the common laser beam source 28 can be used to generate the two output laser beams 32 by the two beam-forming optics 31 . Optionally, two separate laser beam sources 28 can be used.

The heating of at least one section A to be cured moving through the assigned laser beam area 27 can be monitored. For example, a pyrometer 46 can be used for this purpose, as shown schematically in FIG. The pyrometer 46 makes it possible to determine the thermal radiation W generated from the heated point of the card wire 10 in at least one section A to be cured. It is therefore possible to check by the pyrometer 46 whether sufficient energy has been injected into the at least one section A to be cured. Where applicable, the adjustment of the laser beam source 28 may be modified to accommodate the energy injection.

The present invention relates to a laser beam curing method for a section A of a card wire 10 to be hardened. This causes the card wire 10 to move through the work space 26 in the transport direction. An inert gas atmosphere is created in the work space 26 by continuously or discontinuously introducing an inert gas G. A laser beam region 27 is formed in the working space 26, through which the section A of the card wire 10 to be cured moves. As a result, the hardening target section A is heated. After exiting the laser beam region 27, the section A to be cured is cooled and cured by progressing through this temperature profile. Curing in an inert gas atmosphere in the working space 26 avoids the formation of oxide layers (scaling) and tempering colors.

10 card wire 11 base 12 tooth 13 gap 14 corner 15 first edge 16 second edge 17 longitudinal surface 18 first outer surface 1
19 Second outer surface 25 Housing 26 Working space 27 Laser beam area 27a First laser beam area 27b Second laser beam area 28 Laser beam source 29 Laser beam 30 Incoming laser beam 31 Beam forming optics 32 Outgoing laser beam 33 Freedom Curved lens 37 Gas connection 38 Beam dump 39 Contact surface 40 Heat sink 41 Cleaning station 42 Tempering station 43 Heating device 44 Cooling device 45 Drying device 46 Pyrometer A Curing target section B Width direction d Distance E1 First surface E2 Second Surface F Conveying direction G Inert gas H Hardness K Cooling medium L Length direction Q Transverse direction T Depth direction W Thermal radiation x Length of laser beam region y Width of laser beam region Z Transition region

Claims (18)

A method of laser curing a card wire (10) comprising a base (11) and a plurality of teeth (12) protruding from the base, the method comprising:
forming at least one continuous laser beam region (27) within the working space (26);
supplying an inert gas (G) to the work space (26);
The card wire (10) is transported in the transport direction (F) into the working space (26), and the section (A) to be hardened of each tooth (12) is moved through the at least one laser beam region (27). so that at least one outer surface (18, 19) of each section (A) to be cured moves through said at least one laser beam region (27), such that said section (A) to be cured is heated. The process of
a step of cooling the hardening target section (A);
Laser curing method with. 2. Method according to claim 1, characterized in that the card wire (10) moves continuously in the transport direction (F) without stopping. 3. Method according to claim 2, characterized in that the card wire (10) moves at a constant speed in the transport direction (F). Said at least one laser beam region (27) has a non-circular contour with a length (x) in the transport direction (F) and a width (y) perpendicular to said transport direction (F), said width 4. Method according to any one of the preceding claims, characterized in that (y) is particularly shorter than the length (x). 5. A method according to any one of claims 1 to 4, characterized in that the at least one laser beam region (27) comprises at least one straight outer edge. 6. Method according to claim 5, characterized in that the at least one straight outer edge of the laser beam region (27) is oriented parallel to the transport direction (F). 7. Method according to any one of claims 1 to 6, characterized in that the intensity of the laser light changes abruptly at each linear outer edge of the laser beam region (27). Said at least one laser beam region (27) is formed by at least one beam shaping optical system (31) which converts an input laser beam (30) into an output laser beam (32), such that said output laser beam 8. Method according to any one of the preceding claims, characterized in that at least one of the laser beam regions (27) is formed. Method according to any one of the preceding claims, characterized in that there is a beam dump (38) configured to capture at least a part of the laser light of the output laser beam (32). . Method according to claim 5 or 6, characterized in that the beam dump (38) is cooled by a cooling medium (K). Said beam dump (38) comprises at least one entrance surface ( 8. The method according to any one of claims 5 to 7, characterized in that it comprises: 39). 12. A laser beam source (28) according to claim 1, characterized in that the laser beam source (28) emits a laser beam (29) for the formation of said at least one laser beam region (27) having a wavelength of 900 nm-1100 nm. Any one of the methods described. 13. According to any one of claims 1 to 12, characterized in that in the at least one laser beam region (27), the period of application of the laser light to the laser beam region (A) is from 50 ms to 70 ms. Method described. 14. Method according to any one of the preceding claims, characterized in that the card wire (10) is tempered before entering the at least one laser beam region (27). 15. Method according to any one of the preceding claims, characterized in that the card wire (10) is cleaned before entering the at least one laser beam region (27). 16. A method according to any one of the preceding claims, characterized in that a first laser beam region (27a) and a spaced apart second laser beam region (27b) are formed. The first outer surface (18) of the section to be cured (A) moves through the first laser beam region (27a) and is different from the first outer surface (18) of the section to be cured (A). 14. A method according to claim 13, characterized in that an opposite second outer surface (19) moves through the second laser beam region (27b). 18. Method according to any one of claims 1 to 17, characterized in that the heating of the section (A) to be cured is measured.

Images