DE102017213364A1 - Function unit for a machining head, machining head and functional element - Google Patents

Abstract

The invention relates to a functional unit (1) for a machining head, preferably for a laser machining head, comprising: a retaining element (3) which can be fastened to the machining head, and a coupling element (4) which is movable relative to the retaining element (3), wherein the coupling element (4) is designed for the particular releasable connection with a functional element (5). The holding element (3) has a pressure chamber (13) which can be acted upon by a fluid, on the coupling element (4) a piston rod (14) is mounted, which is movably guided in the pressure space (13) linearly in a displacement direction (15) Piston rod (14) has a cavity (19) which is connected via a fluid connection (20) with the pressure chamber (13), and in the coupling element (4) is at least one fluid channel (21) for guiding the fluid of the Cavity (19) of the piston rod (14) to a fluid outlet (28) of the coupling element (4) is formed. The invention also relates to a machining head with such a functional unit (1) and a functional element (5) for such a functional unit (1).

Description

The invention relates to a functional unit for a machining head, preferably for a laser machining head, for example for a laser cutting head, comprising: a holding element, which is fastened to the machining head - typically on a housing of the machining head - and a coupling element which is movable relative to the retaining element , wherein the coupling element is designed for particular releasable connection with a functional element. The invention also relates to a machining head, preferably a laser machining head, for machining, in particular, a workpiece, comprising: a housing and a functional unit as described above, wherein the retaining element is fastened to the housing of the machining head. The invention also relates to a functional element for such a functional unit.

Currently (laser) machining heads, in particular (laser) cutting heads currently used on laser machining systems, in particular on laser cutting machines, have been developed especially with regard to a good cutting functionality with the lowest possible weight. A low weight is sought in order to move the cutting head with high dynamics over the workpiece surface of a workpiece to be machined can. As a rule, it is not provided that additional tasks can be fulfilled by means of the cutting head with the aid of additional functional elements. Occasionally, additional functional elements in the form of gas or water spray nozzles are used on cutting heads, which are used for supplying protective or auxiliary gas or for cooling the workpiece surface of the workpiece to be machined.

For example, is from the DE102012217082A1 a laser processing head with a coaxial with a laser beam axis arranged annular nozzle for introducing an auxiliary gas in an area surrounding the processing zone known. The annular nozzle is slidably mounted along the laser beam axis on the laser processing head and may be rigidly connected to a tubular portion of an auxiliary gas supply slidably mounted on the laser processing head.

From the DE 10 2008 047 760 A1 For example, a laser processing apparatus is known, which has a movement device for moving, in particular for moving, a gas nozzle relative to a laser processing head. The gas nozzle may be formed or attached to a workpiece-side end of a piston rod having an axial bore for gas supply to the gas nozzle.

In addition, various other functional elements have been proposed in the prior art:

In the DE102009038650B4 an extraction device is described in order to suck off emissions arising above the workpiece, in particular during abrasive machining processes. The suction device has a suction cup with a lower shell and with an upper shell.

Out DE102008041774A1 a machining head for laser welding is known in which a contact pressure element for mutual fixation of the workpieces to be welded is integrated. The pressing element is movably connected to a holder on a first side via at least one adjusting element. Out JP2000202669A1 a laser cutting head is known which has a pressing element for holding down the workpiece. The pressing element is mounted in the vertical direction freely movable on the laser cutting head.

Out JP2013046915A , JPH0459196A and JPH05177376A a laser cutting head is known, on which an electromagnet for collecting cut small parts is arranged. In JPH05177376A is also proposed to use suction instead of the electromagnet.

Moreover, it is known, especially for punch-laser combination machines, to arrange brushes as beam protection elements around the jet exit nozzle of the laser processing head, as described, for example, in JPH10137970A or in US Pat EP2468449 A1 is described.

Object of the invention

It is the object of the present invention to provide a functional unit and a machining head with such a functional unit, which allow a compact design of a versatile functional unit.

Subject of the invention

This object is achieved by a functional unit of the type mentioned, in which the holding element has a pressurizable with a fluid pressure chamber, in which on the coupling element, a piston rod is mounted, which is guided linearly movable in the pressure chamber in a displacement direction, in which the Piston rod has a cavity which is connected via a fluid connection with the pressure chamber, and wherein in the coupling element at least one fluid channel for guiding the fluid from the cavity of the piston rod to one formed to a fluid outlet of the coupling element.

In the functional unit according to the invention, the piston rod has a typically continuous cavity, which may be formed, for example, as an axial bore. The acted upon by the fluid pressure chamber in the holding element may be formed in particular as a cylindrical bore. The fluid connection between the pressure chamber and the cavity in the piston rod can be done by an example axial bore in the piston rod, which acts as a throttle. When the pressure space is exposed to the fluid, for example with a gas, for example nitrogen or compressed air, a small portion of the gas flow is selectively directed through the cavity in the piston rod via the fluid connection and arrives via the fluid channel in the coupling element a fluid outlet of the coupling element, which is connectable to a fluid port of the functional element. In the functional element, the fluid can be used to fulfill the function of the functional element, for example to fulfill a suction function. The fluid required for the pneumatic or optionally hydraulic movement of the coupling element can thus be used simultaneously to fulfill the function of the functional element. This allows a simple and compact design of the functional unit, since only a single fluid supply line is needed. If the pressure chamber is no longer acted upon by the fluid, the return of the piston rod can take place in a rest position by a force is applied to the piston rod, which can be generated for example by a (pressure) spring, by a hermetically held pressure chamber, or by in the pressure chamber, a fluid is supplied, which acts in the opposite direction to the piston rod.

In one embodiment, the functional unit has a stop element for limiting the movement of the coupling element relative to the holding element along the displacement direction to a maximum distance, wherein the stop element preferably for changing the maximum distance between the holding element and the coupling element on a carrier element along the displacement direction movable and can be fixed at different positions in the direction of displacement on the support element. The maximum distance between the holding element and the coupling element along the displacement direction is predetermined by the stop element. The support member may be formed as a (threaded) rod which is fixedly connected to the coupling element or with the holding element and whose free end in a slot or the like to the other element, i. on the holding element or on the coupling element, engages. The carrier element is guided in this case via the stop element in the slot and limits the stroke of the coupling element when the stop element reaches the end of the slot. The stop element can be displaced manually or by a motor along the guide rod. The stop element may for example be designed as a sleeve which surrounds the carrier element and can be fixed by means of a screw on the carrier element. Alternatively, the carrier element may be designed as a threaded rod, that is to say comprise an external thread which cooperates with an internal thread of the stop element in order to displace the stop element. With a suitable design of the thread this is self-locking, i. the stop element remains in the set position and is fixed there. In this way, the maximum stroke of the coupling element can be changed and adapted to different functional elements or to different workpiece thicknesses.

In a further embodiment, the functional unit has at least one guide element, in particular a guide rod, for the rotationally secure guidance of the coupling element during the movement along the displacement direction. The guide rod and the piston rod are typically parallel to each other and laterally spaced from each other. The guide rod may be fixedly connected to the holding element or to the coupling element and typically engages in a (further) cavity on the respective other element, i. on the coupling element or on the holding element, a.

In a further embodiment, the functional unit has a functional element which is detachably connected to the coupling element, wherein the functional element has a vacuum generator which is preferably designed as a Venturi nozzle and which generates a negative pressure via a fluid connection with the fluid outlet and thus with the fluid channel of the coupling element is connectable. In the functional element, a negative pressure can be generated in the functional element by the fluid supplied via the fluid connection, i. the function of the vacuum generation is implemented locally in the functional element. It is therefore no external vacuum generator and no connection line to such a necessary. The negative pressure generated in the functional unit can in particular be used to suck in a workpiece or workpiece parts.

In a development, the functional element has at least one suction gripping element, which is connected via at least one suction line to the vacuum generator, in particular in the form of the Venturi nozzle. A Venturi nozzle is a tube having a narrowing in cross-section, for example, created by two opposing tapered tube sections that are at their lowest point Diameter are united. At the location with the smallest diameter, the suction line is typically placed. If the Venturi nozzle flows through a fluid, for example compressed air, then a negative pressure is generated in the suction line (as in the case of a water jet pump) when the suction side of the or the suction gripping elements is closed. This is the case when the suction pads are in contact with the workpiece surface or when they have a passive suction valve that automatically closes when the suction side is not occupied by the workpiece part to be sucked. Several suction gripping elements can be connected via a common suction line with the vacuum generator in the form of Venturi nozzle. With the help of such a functional element also small, filigree or openings having workpiece parts can be sucked and then removed from the remainder of the workpiece and removed.

In a further embodiment, the functional unit described in the introduction or in the preceding paragraphs has at least two functional elements which can be detachably connected to the coupling element and which preferably each have at least one contact element for contacting a workpiece, wherein the at least two functional elements for fulfilling at least two different functions are formed. The functional elements can be connected to the coupling element manually or, if necessary, automatically. Several (different) functional elements may be accommodated in a common magazine in a processing machine, for example in a laser processing machine, to facilitate the replacement, which may be manual or automated, e.g. by means of a controllable gripper arm, can be done.

The coupling element of the functional unit, which is designed as described in the introduction, can be adjusted by means of e.g. electric motor moves relative to the holding element, in particular to be moved. But it is also possible to move the coupling element by means of a piston rod and a pneumatic or possibly hydraulic drive relative to the holding element. The respective functional element can be detachably connected to the coupling element, for example via a screw connection. On the coupling element various functional elements can be attached with and without suction or blowing function in a simple manner. In particular, optional functional elements that require the supply of a fluid to fulfill their function, and functional elements that do not require the supply of a fluid to fulfill their function, can be detachably connected to the coupling element.

In a development, the contact elements of the functional elements are selected from the group comprising: suction gripping element, elastic contact element, in particular elastic pad or brush, ejection pin, Folienanreißelement and shielding. It is understood that one and the same functional element may have two or more contact elements that fulfill a different function. Functional elements which are not intended to come into contact with the workpiece or with the workpiece surface may also be used instead of functional elements having one or more contact elements, for example functional elements which have a nozzle, for example in the form of an annular nozzle or the like, which attached to the machining head nozzle or its nozzle opening annularly surrounds.

The functional elements or their contact elements can fulfill various functions during or after the laser processing process, some of which are described in more detail below:

Functional element with suction pads for small parts

A running with Sauggreifelementen functional element can be used to hold cut small parts in the skeleton and to remove the parts up from the workpiece level. The maximum size of the parts that can be removed with the suction pads is limited by the suction force. A respective sucked with the Sauggreifelementen small part can be removed with the help of the axes of movement of the machining head, such as a cutting head from the workpiece level, moved laterally and dropped, for example as bulk material in a collection.

Functional element with ejection element (s)

A functional element with one or more expressing element (s), for example with a particular elastic contact element, e.g. with a pillow, can serve to express cut small workpiece parts from the skeleton down when they do not fall by themselves. In most cases, these workpiece parts are too light, tilt in the skeletal grid or rotate out of their position by the action of the cutting gas jet emerging from the (laser) cutting head. By expressing these parts, the process reliability of parts removal is significantly increased. As an alternative to an elastic contact element may be provided as a Ausdrückelement a (non-resilient) Ausdrückstift whose force is punctiform.

Functional element with (elastic) hold-down and push-out element (s)

When laser cutting small workpiece parts can be detected and sucked undesirable from the arranged under the workpiece support suction device. In addition, it may happen that the cutting gas released small parts tilted in the skeleton or pressed by the workpiece support or the laser die (punching laser combination machines) down from the skeleton. As a result, the workpiece parts can become dirty, damaged or lost in the Absaugweg or in the remaining process residues / waste parts. A functional element with a designed as a brush or as an elastic cushion elastic contact element can be used to hold the good part when cutting free in a level position. The good part thus remains in the skeleton, without tipping.

Subsequently, the functional element, more precisely the elastic contact element, for example in the form of the brush or the elastic pad, serve to displace the cut-free workpiece part on the workpiece support, for example to a part flap arranged in the workpiece support. When removing small parts via a partial flap in the workpiece support, it may happen that the parts do not fall off immediately, if they are light and the partial center of gravity lies behind the flap start edge. Such parts can be moved by means of the elastic contact element and positioned on the part flap. The part only falls when the elastic contact element is raised again, thus releasing the part. Also in this way the process reliability is increased at the part removal.

Function element with foil marker (and peel-off aid)

With a functional element, which has a contact element with one or more thorns or balls, the foil of a foiled workpiece (sheet) can be scratched and pulled up. This facilitates the removal of the film from a foiled workpiece before the laser processing takes place.

Functional element with shielding function

If a contact element in the form of a brush ring-shaped and constructed as opaque unit of radiation-resistant bristles, the brush (in addition) can be used as a beam protection element, i. fulfill a shielding function.

Another aspect of the invention relates to a machining head, preferably a laser machining head, in particular a laser cutting head, for the particular cutting machining of a workpiece, comprising: a housing, and a functional unit, as described above, wherein the retaining element of the functional unit on the housing of the machining head is attached. As described above, laser processing heads, in particular laser cutting heads, have been developed especially with regard to good cutting functionality with the lowest possible weight, in order to be able to move the cutting head over the workpiece surface with high dynamics. As a result of the compact functional unit described above, the machining head, for example in the form of a laser cutting head, can assume at least one additional function without significantly reducing the dynamics of the cutting head.

In one embodiment, the machining head additionally comprises a movement device with a pneumatic drive, in particular, for moving the coupling element and thus the functional element between a rest position remote from the work piece and a working position close to the work piece, in particular by pressurizing the pressure space of the holding element with a fluid, typically with a gas.

The movement of the functional element, more precisely of the coupling element connected thereto, can be effected, for example, by supplying a fluid in the retaining element to the pressure chamber which exerts a force on the piston rod in order to move the piston rod and thus the functional element from the inoperative position to move the functional position, in particular to move linearly. If the functional element is not required, the functional element can be moved back to the workpiece-distant rest position. In the simplest case, the supply of fluid to the pressure chamber is stopped for this purpose, for example by a connecting line of the movement device or the pneumatic drive between the pressure chamber and a gas reservoir, such as a compressed air circuit, is closed by means of a controllable valve. As described above, the movement of the piston rod of the coupling element or the functional element from the functional position to the rest position by a return spring or the like can take place, which is arranged for example in the pressure chamber and acts on the piston rod, more precisely on a piston effective surface. Alternatively, the pressure chamber may be formed, for example, as a double-acting pneumatic cylinder, in which the movement of the piston rod from the rest position to the functional position and vice versa by the supply of a fluid into the pressure chamber. The movement device controls the movement of the functional element in the Rest position to protect it from contamination during the machining process by placing it further away from the workpiece. Typically, the functional position is selected so that the at least one contact element of the functional element in the functional position comes into contact with the workpiece and / or with cut workpiece parts.

The invention also relates to a functional element for a functional unit for a machining head, in particular for a functional unit according to the invention as described above, comprising: a vacuum generator and at least one suction gripping element which is connected via at least one suction line to the vacuum generator, wherein the functional element at least one fluid Having a connection for supplying a fluid to the vacuum generator for generating a negative pressure in the suction line in order to suck by means of the at least one suction gripper, the workpiece - or workpiece parts typically cut free from the workpiece.

As described above, the vacuum generation function is implemented locally in the functional element, i. it is only necessary for the generation of the negative pressure to supply a fluid to the vacuum generator of the functional element via the at least one fluid connection.

In one embodiment, the vacuum generator has a Venturi nozzle, to which the fluid can be supplied in order to generate the negative pressure in the suction line. As described above, the Venturi nozzle is typically formed as a tube with a constriction of the cross section, for example in the form of a double cone, wherein the end of the suction line opens into the constricted tube cross section. The fluid can be flowed into the Venturi nozzle in the axial direction, but it is also possible that the fluid is flowed into the Venturi nozzle via a lateral inlet.

In one embodiment, the fluid connection is formed in a connection region of the functional element for connecting the functional element to the coupling element in order to connect the fluid connection of the functional element to a fluid line of the coupling element. In order to connect the functional element in the connection region in a fluid-tight manner to the coupling element, the connection region is typically designed as a plane (stop) surface against which a corresponding connection region of the coupling element in the form of a planar surface is brought into abutment. For the fluidtight connection, at the coupling element at the exit end of the fluid conduit, i. be attached to the fluid outlet, a sealing element, for example in the form of a sealing ring. If the functional element is screwed into the connection area with the coupling element, a fluid-tight connection between the coupling element and the functional element can be produced in this way.

When connecting a coupling element to a functional element that does not require the supply of a fluid, it is typically advantageous to close the fluid outlet of the coupling element in a fluid-tight manner, since otherwise fluid permanently escapes via the fluid connection in the pressure chamber at least in the functional position of the functional element , Functional elements that do not fulfill a suction function or any other fluid-requiring function (nozzle function) have no fluid connection in the connection region. By using a plane connecting surface and a sealing element attached to the fluid outlet, for example in the form of the above-described sealing ring, the fluid line in the coupling element can be sealingly closed when the functional element is screwed to the coupling element.

In a further embodiment, the fluid connection to the functional element is formed outside a connection region for connecting the functional element to the coupling element. In this case, the fluid connection is used to connect an (external) fluid supply line, for example a compressed air supply line, to the vacuum generator. In this case, the fluid is not supplied to the vacuum generator by the coupling element.

Further advantages of the invention will become apparent from the description and the drawings. Likewise, the features mentioned above and the features listed further can be used individually or in combination in any combination. The embodiments shown and described are not to be understood as exhaustive enumeration, but rather have exemplary character for the description of the invention.

• 1a,b schematische Darstellungen eines Ausführungsbeispiels einer Funktionseinheit mit einem Halteelement, einem Kopplungselement und einem Funktionselement, das Kontaktelemente in Form von Sauggreifelementen aufweist,
• 2a,b schematische Darstellungen eines Bearbeitungskopfs mit einer solchen Funktionseinheit mit dem Funktionselement in einer werkstückfernen Ruhestellung und in einer werkstücknahen Funktionsstellung,
• 3a,b schematische Darstellungen eines Funktionselements, welches einen Unterdruckerzeuger in Form einer Venturi-Düse und eine Mehrzahl von Sauggreifelementen aufweist,
• 4a-d schematische Darstellungen von vier Funktionselementen, die jeweils ein Kontaktelement aufweisen, das zur Erfüllung einer jeweils unterschiedlichen Funktion dient, sowie
• 5a,b Darstellungen von zwei Funktionselementen mit einem Verbindungsbereich ohne bzw. mit einem Fluid-Anschluss.

Show it:

• 1a, b schematic representations of an embodiment of a functional unit having a holding element, a coupling element and a functional element having contact elements in the form of Saugrreifelementen,
• 2a, b schematic representations of a machining head with such a functional unit with the functional element in a workpiece distant rest position and in a workpiece-near functional position,
• 3a, b schematic representations of a functional element, which has a vacuum generator in the form of a Venturi nozzle and a plurality of Sauggreifelementen,
• 4a-d schematic representations of four functional elements, each having a contact element, which serves to fulfill a respective different function, and
• 5a, b Representations of two functional elements with a connection area without or with a fluid connection.

In the following description of the drawings, identical reference numerals are used for identical or functionally identical components.

1a, b show an exemplary structure of a functional unit 1 for attachment to an in 2a, b shown processing head, as a laser processing head 2 is formed in the form of a laser cutting head. The functional unit 1 has a retaining element 3 , a coupling element 4 and a functional element 5 on. The holding element 3 is on the laser processing head 2 more precisely on a housing 6 of the laser processing head 2 , attachable via a screw connection. Accordingly, the holding element 3 in the presentation of 2a, b on the housing 6 of the laser cutting head 2 attached via a screw connection.

The laser processing head 2 is used for the cutting machining of a plate-shaped workpiece, for example 7 in the form of a sheet. The laser processing head 2 not shown optical elements to a laser beam along an optical axis 8th on the workpiece 7 to guide and to focus there for the cutting processing. To assist the cutting process is via a on the laser processing head 2 attached cutting gas nozzle 9 a gas in the region of a processing point on the workpiece 7 brought in.

The coupling element 4 the functional unit 1 is relative to the retaining element 3 and thus relative to the laser processing head 2 from one in 2a represented, from the workpiece to be machined 7 distant (workpiece distant) rest position R into an in 2 B shown, workpiece near functional position F movable, for example, linearly displaceable. In the in 2 B shown functional position F are located on the functional element 5 attached contact elements in the form of Sauggreifelementen 10 at the top of the workpiece 7 on to the workpiece 7 and / or from the workpiece 7 cut workpiece parts, to suck.

For the linear displacement of the coupling element 4 and at this via a screw detachably fastened functional element 5 serves in the example shown, a movement unit 11 in the laser processing head 2 is integrated, but which can also be arranged elsewhere in a laser processing machine, not shown. The movement unit 11 has in the example shown a pneumatic drive 12 which essentially serves to supply a fluid, in the example shown in the form of compressed air, to one in the holding element 3 formed pressure chamber 13 to control. The pneumatic drive 12 controls a controllable valve to the compressed air from a compressed air reservoir via a non-illustrated supply line to the gas port 14 of the holding element 3 to feed and into the pressure room 13 to flow in.

The pressure room 13 is at the in 1a, b illustrated example as a cylindrical bore in the holding element 3 educated. In the pressure room 13 of the holding element 3 is a piston rod 14 linear in one direction 15 movably guided, wherein the direction of displacement 15 in the example shown, parallel to the optical axis 8th of the laser cutting head 2 runs. A free end of the piston rod 14 is fixed to the coupling element 4 connected. By the application of the end face of the piston rod 14 with compressed air, the piston rod 14 on the in 2a, b represented workpiece 7 to be moved until the functional position F is reached.

For the movement of the functional element 5 from the in 2 B shown functional position F in the in 2a shown rest position R is the supply of compressed air of the pneumatic drive 12 off. A non-pictorial, in the pressure room 13 attached return spring serves to apply a force to the piston rod 14 in a the workpiece 7 opposite direction to the piston rod 14 and thus the coupling element 4 along the direction of displacement 15 in the in 2a shown rest position R to move, in which the coupling element 4 on the holding element 3 is applied.

To the lifting movement of the coupling element 4 or of the functional element 5 to limit, assigns the functional unit 1 a stop element 16 on. The stop element 16 is in the example shown on a support element in the form of a threaded rod 17 attached, with one end fixed to the coupling element 4 is connected and with its free end in a on the holding element 3 formed slot 18 protrudes, in which in the example shown spherical stop element 16 is guided. 1b shows the stop element 16 in a on a the workpiece 7 facing the end of the slot 18 position in which this the movement of the coupling element 4 and thus the functional element 5 in the functional position F to a maximum distance A _M to the holding element 3 limited, as well as in 2 B is shown.

In the example shown, the stop element 16 along the threaded rod 17 moved and in different places along the threaded rod 17 be determined. The movement of the stop element 16 along the threaded rod 17 For example, can be done manually, but it is also possible that for this purpose a separate drive in the laser processing head 2 or in the functional unit 1 is integrated. By changing the position of the stop element 16 in the direction of displacement, the maximum distance A _M , between the holding element 3 and the coupling element 4 is taken in the functional position F, can be set. This is favorable to the functional position F or to the maximum distance A _M between the holding element 3 and the functional element 5 to different types of functional elements 5 . 5a-d (see below) and to different thicknesses of the workpiece 7 or lengths of the nozzle 9 adapt.

As in 1b can be seen, is on the coupling element 4 a guide element in the form of a guide rod 17a attached in an associated, along the direction of displacement 15 extending bore in the retaining element 3 intervenes. The guide rod 17a has a comparatively large diameter is to the piston rod 14 laterally offset and thus enables a torsion-proof and low-backlash guidance of the coupling element 4 during the displacement along the direction of displacement 15 ,

To the functional element 5 over the coupling element 4 in the pressure room 13 of the holding element 3 to be able to supply incoming compressed air, has in the 1a, b and in 2a, b shown example, the piston rod 14 a cavity 19 in the form of a continuous axial bore. The cavity 19 is about one on the front side of the piston rod 14 formed fluid connection 20 with the pressure room 13 connected. The fluid connection 20 is in the example shown as an end-face use in the piston rod 14 formed and has an axial bore with a comparatively small flow cross section, so that the fluid connection 20 acts as a throttle. Accordingly, only a comparatively small proportion or volume flow of the compressed air from the pressure chamber 13 in the cavity 19 the piston rod 14 and from this into one in the coupling element 4 educated, in 1b indicated fluid channel 21 as well as to an in 1b indicated fluid outlet 28 ,

3a, b show the functional element 5 from 1a, b and from 2a, b in a simplified representation, in which the suction pads 10 not shown. In the sectional view of 3a is one in the functional element 5 integrated vacuum generator in the form of a Venturi nozzle 23 to recognize. The venturi nozzle 23 has two conical pipe sections, which adjoin one another in a region with minimal pipe cross-section, in which a suction line 25 empties. The suction line 25 extends annularly within the substantially annular base body 26 of the functional element 5 , so that all on the annular body 26 attached suction gripping elements 10 with the suction line 25 keep in touch.

Will the venturi nozzle 23 flows through a fluid is in the suction line 25 generates a negative pressure, provided the suction side at the bottom of the suction pads 10 closed is. This is the case when the suction pads 10 with the surface of the workpiece 7 be in contact, as in 2 B is shown, or if the suction pads 10 - as a passive vacuum cleaner - are provided with a valve that closes automatically, provided that the suction side is not occupied or closed by a workpiece part to be sucked.

At the in 3a, b example shown are on the functional element 5 two fluid connections 22a, b to illustrate the two alternative possibilities by which a fluid - in the example shown, a gas, eg compressed air - in the Venturi nozzle 23 can be initiated. Normally, the functional element points 5 only one of the two fluid connections 22a, b on. The supplied gas flows through the Venturi nozzle 23 and leaves it at an exit-side nozzle end 24 , As in 3b it can be seen, is the first fluid connection 22a in the form of a hole in a connection area 27 of the functional element 5 formed on which the functional element 5 with the coupling element 4 is detachably connected. The releasable connection is made by a screw connection, made of 1a, b and for simplicity in 3a, b not shown. At the exit end of the fluid line 21 (Fluid outlet 28 , see. 1b) of the coupling element 4 For example, a sealing ring or the like may be attached to the fluid conduit 21 fluid-tight with the first fluid port 22a connect so that the gas or fluid from the pressure chamber 13 of the holding element 3 over the coupling element 4 into the venturi nozzle 23 can flow in.

As in 3a, b is shown flowing in the fluid line 21 of the coupling element 4 transported fluid through the first fluid port 22a laterally in the Venturi nozzle 23 one. The second, alternative fluid port 22b is outside the connection area 27 on the body 26 of functional element 5 attached and can be connected to an external fluid supply line, for example with a compressed air line. Through the second fluid connection 22b the fluid flows in the axial direction into the Venturi nozzle 23 a, like this in 3a is shown. The second fluid connection 22b is then provided when the functional element 5 with a coupling element 4 is connected, no fluid channel 21 having. Is the fluid over the fluid port 22a through the coupling element 4 supplied, so is the connection 22b not intended or closed.

At the in 1a, b shown functional unit 1 or on a functional unit 1 that like in 1a, b a holding element 3 and a coupling element 4 which are movable relative to each other, in which the movement but in other ways, for example by means of an electric motor or a pneumatic drive with a piston rod 14 without a cavity 19 can be done next to the in 3a, b illustrated functional element 5 with the suction pads 10 also other functional elements 5a-d be releasably secured, of which in 4a-d an exemplary selection is shown, each having different contact elements 10a-d to fulfill a respective different function.

4a shows a functional element 5a , which is an elastic contact element in the form of a brush 10a has, for example, can serve as hold-down for holding a good part in a flat position during cutting free when the brush 10a against the workpiece 7 or pressed against the workpiece part. That as a brush 10a formed contact element is annular in the example shown and on a substantially annular base body 26 of the functional element 5a appropriate. The brush 10a , which is constructed in the example shown from radiation-resistant bristles, forms an opaque unit and thus simultaneously serves as a shielding or radiation protection element. The brush 10a can also be used for expressing cut-free small workpiece parts from the skeleton grid down, if they do not fall by themselves from the skeleton grid down. By expressing small workpiece parts that might otherwise get caught in the skeleton grid, the process reliability can be increased when removing workpiece parts from the skeleton.

Alternatively to using a brush 10a can also be used for expressing a rigid contact element, for example in the form of an in 4b illustrated Ausdrückstifts 10b , which is another functional element 5b is appropriate. The ejector pin 10b allows a more punctual force on the workpiece 7 than this at the in 4a shown brush 10a or at a in 4d illustrated contact element in the form of an elastic pad 10d the case is that can also be used to express workpiece parts.

This in 4d shown elastic pillows 10d can as well as the in 4a shown brush 10a can be used as hold-down to keep small workpiece parts horizontally on the workpiece support when cutting free. Both the elastic pillow 10d as well as the brush 10a can also serve to move cut workpiece parts on the workpiece support, for example in the range of a part of the flap in the workpiece support. This is favorable, as long as a respective small workpiece part does not fall by itself, which is the case in particular when the center of gravity of the workpiece part does not lie above the partial flap. In this case, the workpiece part with the respective elastic contact element 10a . 10d be moved until the center of gravity of the workpiece part is positioned over the parts flap. The cut workpiece part falls in this case only when the elastic contact element 10a . 10d is raised again and releases the workpiece part. Also in this way the process reliability can be increased when removing small workpiece parts.

4c shows a functional element 5c , which is a contact element in the form of a film-tearing element 10c having a spike. The mandrel or one on the Folienanreißelement 10c attached (not shown) ball on the surface of a workpiece 7 scrape applied film or at least partially raise it. This facilitates the removal of the film from the workpiece 7 before, in a subsequent step, the workpiece 7 (without the foil) with the help of the laser processing head 2 is processed.

5a shows the functional element 5a from 4a with the contact element in the form of a brush 10a . 5b this in 3a, b shown functional element 5 with the contact elements in the form of Sauggreifelementen 10 , As in 5a can be seen, has the functional element shown there 5a in the connection area 27 no fluid connection 22a on, because the functional element shown there 5a unlike that in 5b illustrated functional element 5 no fluid supply needed to fulfill its function. The in the coupling element 4 formed fluid line 21 thus ends at the planar interface 27 of the functional element 5a ,

By the sealing element described above, for example in the form of a sealing ring, is when screwing the functional element 5a that does not require fluid supply, the fluid line 21 or the outlet end (fluid outlet 28 ) through the plane connecting surface 27 of the functional element 5a from 5a sealed fluid-tight. In this way, both functional elements 5 , which require a fluid supply, as well as functional elements 5a-d , in which no fluid supply is required, on one and the same contact element 4 be attached, thereby providing flexibility in the use of different functional elements 5 . 5a-d is increased.

In the examples shown above, the functional elements are 5 . 5a-d mostly shown as annular elements which the cutting nozzle 9 of the laser processing head 2 from which the laser beam also exits, surrounded annularly. Such an embodiment in which the functional element 5 . 5a-d or its basic body 26 has a substantially annular geometry, allows a uniform operation of the respective functional element 5 . 5a-d in the immediate vicinity of the processing point on the workpiece 7 , Alternatively, the functional elements 5 . 5a-d or their basic body but also be square, pointed, U-shaped or finger-shaped, in particular, combinations of different shapes or geometries are possible. For example, this can be done in 3a, b shown functional element 5 with the suction pads 10 have a fork shape or a fork-shaped body. Also a functional element 5a . 5d with an elastic contact element in the form of a brush 10a or an elastic pillow 10d on a fork-shaped body are possible. Also can on one and the same functional element 5 . 5a-d two or more contact elements 10 . 10a-d be appropriate, each fulfilling a different function.

QUOTES INCLUDE IN THE DESCRIPTION

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

Cited patent literature

• DE 102012217082 A1 [0003]
• DE 102008047760 A1 [0004]
• DE 102009038650 B4 [0006]
• DE 102008041774 A1 [0007]
• JP 2000202669 A1 [0007]
• JP 2013046915 A [0008]
• EP 2468449 A1 [0009]

Claims (13)

A processing unit (1) for a machining head, preferably for a laser processing head (2), comprising: a holding element (3) attachable to the processing head and a coupling element (4) movable relative to the holding element (3) the coupling element (4) is designed to be in particular releasably connected to a functional element (5), characterized in that the retaining element (3) has a pressure chamber (13) which can be acted upon by a fluid, that a piston rod (14) is attached to the coupling element (4). is mounted, which is in the pressure chamber (13) linearly guided in a direction of displacement (15) movable, that the piston rod (14) has a cavity (19), which via a fluid connection (20) connected to the pressure chamber (13) is, and in that in the coupling element (4) at least one fluid channel (21) for guiding the fluid from the cavity (19) of the piston rod (14) to a fluid outlet (28) of the coupling element (4) is formed. Function unit after Claim 1 , further comprising: a stop element (16) for limiting the movement of the coupling element (4) relative to the holding element (3) along the displacement direction (15) to a maximum distance (A _M ), wherein the stop element (16) is preferably used to change the maximum distance (A _M ) between the holding element (3) and the coupling element (4) on a carrier element (17) along the displacement direction (15) movable and at different positions in the direction of displacement (15) can be fixed. Function unit after Claim 1 or 2 , further comprising: at least one guide element, in particular a guide rod (17a), for the rotationally secure guidance of the coupling element (4) during the movement along the displacement direction (15). Functional unit according to one of the preceding claims, further comprising: a functional element (5) which is detachably connected to the coupling element (4), wherein the functional element (5) has a vacuum generator, preferably designed as a Venturi nozzle (23), which generates a negative pressure via a fluid connection (22a) the fluid channel (21) of the coupling element (4) is connectable. Function unit after Claim 4 in which the functional element (5) has at least one suction gripping element (10) which is connected to the vacuum generator via at least one suction line (25). Functional unit according to the preamble of Claim 1 , in particular according to one of the preceding claims, further comprising: at least two functional elements (5, 5a-d) which are selectively connectable to the coupling element (4) and which preferably each at least one contact element (10, 10a-d) for contacting a workpiece (7), wherein the at least two functional elements (5, 5a-d) are designed to fulfill at least two different functions. Function unit after Claim 6 in which the contact elements (10, 10a-d) are selected from the group comprising: suction gripping element (10), elastic contact element, in particular brush (10a) or elastic pad (10d), ejection pin (10b), film-tearing element (10c) and shielding element (10a). Processing head, preferably laser processing head (2), for the particular cutting machining of a workpiece (7), comprising: a housing (6) and a functional unit (1) according to one of the preceding claims, wherein the retaining element (3) is fastened to the housing (6) of the machining head. Machining head after Claim 8 , further comprising: a movement device (11) with an in particular pneumatic drive (12) for moving the functional element (5) between a rest position (R) remote from the work piece and a working position (F) close to the work piece, in particular by acting on the pressure space (13) of the holding element ( 3) with a fluid. Functional element (5) for detachable connection to a coupling element (4) of a functional unit (1) according to the preamble of Claim 1 , in particular a functional unit (1) according to one of Claims 1 to 7 comprising: a vacuum generator (23) and at least one suction gripping element (10) which is connected via at least one suction line (25) to the vacuum generator (23), wherein the functional element (5) at least one fluid port (22a, 22b) for Supplying a fluid to the vacuum generator (23) for generating a negative pressure in the suction line (25). Function element after Claim 10 in which the vacuum generator forms a Venturi nozzle (23), to which the fluid can be supplied in order to generate the negative pressure in the suction line (25). Function element after Claim 10 or 11 in that the fluid connection (22a) is formed in a connection region (27) of the functional element (5) for connecting the functional element (5) to the coupling element (4) in order to connect the fluid connection (22a) to a fluid line (21 ) of the coupling element (4). Function element according to one of Claims 10 to 12 in which the fluid connection (22b) on the functional element (5) is formed outside a connection region (27) for connecting the functional element (5) to the coupling element (4).

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