Joining tool unit, tool pliers and joining process

Abstract

A joining tool unit (2) is proposed, which has a clamping device (6) and a linearly movable tool (7) and a tool corresponding element (4), wherein the clamping device exists opposite to the tool corresponding element, wherein the workpiece (25) rests on the tool corresponding element when arranged on the joining tool unit, wherein the clamping device can be arranged to rest on the surface of the workpiece when the workpiece is arranged on the joining tool unit, wherein the clamping device has a light guide system (9), wherein the light guide system is constructed to guide a light beam in the direction of a joining position of the workpiece when the workpiece is arranged on the joining tool unit, wherein the light guide system is present on the clamping device so that the light beam is incident on the joining position only at an angle greater than 0° relative to the moving axis of the linearly movable tool, wherein the light guide system of the clamping device shields the light along its light beam to the outside in a light-proof manner.

Description

Background Art

[0001] Joining tool units for machining workpieces are known, for example joining tools having a unit for joining by deforming the workpieces, wherein the workpiece is held between two parts of the joining tool unit during the machining process.

[0002] One part comprises, for example, a tool or a tool element of a joining tool unit, such as a punch or a die.

[0003] When considering the use of known joining tool units in the context of applying alternative or new technologies, significant practical problems often arise, which relate, for example, to the safety of personnel working in the surroundings of the place of use and / or to practically extensive applications, for example in automation processes. Some technologies, on the one hand, have outstanding advantages for specific areas of application, but on the other hand, face significant obstacles in practical implementation, i.e. various technologies with great potential for industrial applications are not widely used or have not yet moved beyond the research or development stage. Summary of the invention

[0004] The object of the present invention is to provide an improved joining tool unit or an improved joining process when using alternative technologies. In particular, the object of the present invention is to provide a joining tool unit with which light-based technologies can be used in a practical and advantageous manner for the input of energy on the workpiece side by means of a light beam with sufficiently high safety for the user and for automation applications.

[0005] This object is achieved by the present invention.

[0006] Expedient and advantageous variants of the invention are shown in the embodiments described below.

[0007] The present invention relates to a joining tool unit, wherein a clamping device of the joining tool unit comprises a tool capable of linear movement and a tool corresponding element, wherein the clamping device having the tool capable of linear movement exists opposite to the tool corresponding element, wherein the workpiece rests on the tool corresponding element when arranged on the joining tool unit, wherein the clamping device can be arranged so as to rest on the surface of the workpiece when the workpiece is arranged on the joining tool unit, wherein the clamping device has a light guide system, wherein the light guide system is constructed to guide a light beam in the direction of a joining portion of the workpiece when the workpiece is arranged on the joining tool unit, wherein the light guide system is present on the clamping device so that the light beam is incident on the joining portion only at an angle greater than 0° relative to the moving axis of the linearly movable tool, wherein the light guide system of the clamping device shields the light along its light beam outwardly in a light-proof manner.

[0008] With the aid of the light guide system, the joining tool unit can be used in a practical and applicable manner. In particular, the joining tool unit can be used advantageously without extreme additional measures, for example in terms of safety aspects with regard to potential hazards of high light energy. It can thus be advantageously achieved in practice that the joining tool unit according to the invention is provided for an extended range of applications compared to known joining tool units. With the aid of the invention, structural advantages and thus technical advantages as well as safety technical advantages can be achieved.

[0009] The shielding of the light beam from light to the outside by the light guide system relates to the state in which the workpiece is arranged on the joining tool unit. The light guide system is provided for emitting the light beam, for example in the region of the free front end of the clamping device, and is then covered by the surface or the outer side of the workpiece. In this case, the clamping device rests with its end side on the surface of the workpiece.

[0010] Therefore, the light beam and thus the safety-related part of the light energy cannot reach the surrounding environment. The light beam is shielded on its path to the exit by the light guide system or by the surrounding wall, such as a hole, of a closed pipeline, for example, integrated in the clamping device.

[0011] The light beam leaves the light guide system at the exit and then strikes the surface of the workpiece in the region of the joint or joint to be formed next. Due to the energy input by the light beam, the workpiece material heats up and softens by absorbing the light energy.

[0012] When a workpiece is not arranged on the joining tool unit, safety precautions are taken in that no light beam is present or the light source is deactivated in order to reliably avoid hazards to persons in the vicinity of the joining tool unit.

[0013] The light guide system described is used to construct the joining tool unit in a relatively simplified and in particular relatively cost-effective manner. This makes it possible, for example, to realize a joining tool unit that does not require an additional housing for radiation protection of the workers. The light guide system is integrally constructed and provides radiation protection to the outside. This is particularly important and advantageous, for example, in laser applications.

[0014] In particular, materials or material combinations that can currently be processed with difficulty or impractically with conventional joining tools can advantageously also be processed under industry-relevant regulations with the joining tool unit including beam processing based on the light guide system. Thus, the joining tool unit can be used with the aid of beam processing with the help of the light guide system for applications characterized by a relatively high degree of automation, for example in production line production of vehicles, for example in automobile production.

[0015] A disadvantage of the solution of light-based energy input on the workpiece by means of a joining tool unit is the relatively long joining cycle time. It is also disadvantageous here that, due to the use of lasers, for example, it is necessary to ensure that people in the surroundings near the joining tool unit are protected from radiation effects, and the people may work with the joining tool unit or stay in the area of ​​the joining tool unit. In such a joining tool unit, for example, the entire joining tool unit must be provided with a housing for this purpose, which is impermeable to the light of the laser beam or shields the light from the outside. This solution is relatively expensive and complex and is not practically applicable for automated, for example robot-assisted production lines.

[0016] The light guide system is configured, for example, so that, in the extension of the light beam, the radial spacing of the light beam relative to the axis of movement of the movable tool decreases or becomes smaller in the direction of the tool counter-element or the free end side of the clamping device. The light beam preferably has a straight, for example non-focused or non-expanded direction. Accordingly, the pipeline of the light guide system is also preferably configured in a straight line or with a constant continuous tilted positioning in the clamping device, and the tilted positioning is between an angle of zero and an angle of 20 degrees relative to the axis of movement of the movable tool.

[0017] The light guide system or the light beam is oriented in such a way that, when the workpieces are arranged, the light strikes the area of ​​the surface of the workpiece in which a joining process, such as a joining process, is carried out by a movable tool, in particular the movable tool acts on the surface in a deforming manner, for example, penetrates into the workpiece during processing. Preferably, the area of ​​the surface of the workpiece irradiated or applied by the light beam forms an almost circular surface. The size and / or shape of the surface area of ​​the workpiece surface irradiated by the light beam emitted from the clamping device is within the size and / or shape of the end face of the movable tool that acts on the workpiece surface during workpiece processing.

[0018] The invention advantageously achieves a basic functional expansion by means of new functions of a standard component of a tool unit or a hold-down device. The standard component is advantageously a component close to the workpiece or a punch-side and / or die-side hold-down device.

[0019] Due to the possibility of heating the workpieces to be joined by means of the joining tool unit, it is possible to improve already possible or previously known joining applications.

[0020] With the aid of a light guide system integrated in the clamping device, the light beam can be advantageously guided directly or even directly onto the workpiece. The light guide system can also be integrated and included in the component volume of the clamping device without remodeling or reconfiguring the clamping device. In addition, integrated installation inside a component, for example inside a clamping device that necessarily or always belongs to the joining tool unit, is achieved.

[0021] Compared to known joining tool units, modifications of the joining tool unit are therefore not necessary or are not undesirable.

[0022] Advantageously, compared to known joining tool units, no additional or additional components are required on the joining tool unit by means of the described light guide integrated in the hold-down device. Furthermore, advantageously, no further kinematic devices are required, for example with drive devices and movement guide devices and movement deflection devices for providing beam guidance and the light beam, for example for providing the beam path of the light beam or for moving towards and away from a section of the joining tool unit that is present in the beam path in previous joining tool units, which entails structural, economic and technical disadvantages.

[0023] For providing the light beam a light source is provided, for example a laser light source, which is for example part of a joining tool unit.

[0024] The slightly tilted positioning or tilted orientation of the light beam towards or towards the joining point on the workpiece enables, on the one hand, a relatively slender structural form of the clamping device, in particular at its front end section facing the tool counterpart element, while the outer dimensions of the clamping device are hardly changed at this end section, which is, for example, beneficial for the arrangement and accessibility of the joining tool unit on the workpiece or the joining point to be processed by means of a movable tool.

[0025] In addition, the connection and positioning of the light guide system and the light source on the joint tool unit can be advantageously realized, for example, in the region of the front end portion away from the hold down device, and the hold down device is toward the tool corresponding element. Under the situation of the light beam tilt positioning, with the increasing spacing of the light guide system and the front end portion of the hold down device, the radial spacing relative to the moving axis of the movable tool becomes larger. Due to the inclined optical path, the region that is relatively wide or has a large diameter, away from the front end portion of the hold down device is insensitive to space. Therefore, it can be advantageously realized there to connect to the components and circuits of the light guide system in the hold down device, for example, the plug connection for the interface device.

[0026] For example, the light guide system encloses the light along the light beam or along its light path in the joining tool unit or in a space that can be occupied by the light beam. Thus, the light is shielded from light in a radial direction relative to the light beam or in a radial direction relative to the light path by the light guide system. The light-tight shielding of the light beam in the hold-down device provided by the light guide system can advantageously be provided, in particular, based on a concealed or integrated arrangement of the light guide in the hold-down device.

[0027] Preferably, light-tight shielding by the light-conducting system in the hold-down device can advantageously be provided based on lines of the light-conducting system, for example machined out of the solid material of the hold-down device, inside the hold-down device or in the surrounding solid material of the hold-down device.

[0028] Light-tight means, with respect to the state of the workpiece arranged on the joining tool unit or on the hold-down device, in particular with respect to a power loss of between 0% and 20% of the power of the light in the light-guiding system or in the lines of the light-guiding system. The lines of the light-guiding system are present inside the hold-down device. The maximum power loss of approximately 20% understood under light-tightness can also refer to another reference value for the light power, for example the light output power of the light beam of the light beam source or the rated power of the device.

[0029] The power loss preferably relates to the power of the light in the light guide system of the clamping device in the open end of the light guide system of the clamping device, for example in the region of the exit opening. This power can be different from the power of the light that can be measured at the light source, because the light from the light source along the path of the light path that follows in the light guide system produces power losses due to, for example, reflection or absorption or chemical reactions.

[0030] The open end or the outlet of the light guide system of the clamping device is especially oriented toward the workpiece surface of the workpiece to be processed. Starting from the open end of the light guide system, the light beam is projected onto the surface of the workpiece to be heated. This surface is, for example, the region of the outlet point of the light guide system's pipeline on the clamping device, on the end of the clamping device facing the tool counter-element or on the side facing the bottom mold unit.

[0031] Accordingly, a clamping device with a linearly movable tool, preferably a punch or a plunger of a punch unit, is present relative to the die unit in the direction of the joining axis. The joining tool unit comprises, for example, a punch unit with a tool configured as a punch and a die unit, between which a workpiece can be positioned.

[0032] The exit area of ​​the light beam at the end of the pipeline of the light guide system in the clamping device is directed toward the workpiece when the workpiece is arranged. The light beam is projected onto the workpiece surface on the clamping device side, which faces the clamping device. The workpiece is abutted against a tool counter-element, such as the end side or the abutment side of the bottom mold, with the workpiece side opposite or facing away from the workpiece surface on the clamping device side.

[0033] For example, the movable tool is only linearly movable along the axis of movement of the joining tool unit. For this purpose, a drive unit, for example a linear drive, for example a pneumatic-hydraulic, hydraulic, pneumatic and / or electric drive unit is provided. The drive for the movable tool and / or the clamping device preferably comprises an electromechanical servo drive.

[0034] In the state where the workpiece is arranged on the joining tool unit, the hold-down device usually contacts the workpiece with, for example, a flat or planar side, for example with its end side, wherein the plane of the end side is oriented axially in the tool movement direction, preferably parallel to the relevant surface orientation of the workpiece at least during the joining process. The hold-down device can also realize a disengager function. The disengager function supports or realizes the separation of the tool from the workpiece after the joining process. The hold-down device can be configured alternatively to be used alone as a radiation shielding device and / or alone for guiding a light beam.

[0035] For example, the clamping device can be arranged by the joining tool unit against the surface of the workpiece when the workpiece is arranged on the joining tool unit. The arrangement against the workpiece can be carried out by means of a drive unit and / or a spring unit of the joining tool unit. Preferably, preferably exactly one drive unit acts on the movable tool, for example a punch. The drive unit preferably acts on the clamping device and / or the spring unit.

[0036] For example, the clamping device can be arranged against the surface of the workpiece in a state where the workpiece is arranged on the joining tool unit, so that the clamping device touches and / or contacts the surface. The contact quality between the clamping device and the workpiece can be influenced by the presetting of the force, wherein the force is a clamping force or a pressure, which acts between the clamping device and the surface of the workpiece. For this purpose, for example, there is a mechanical spring, such as a helical pressure spring or a pneumatic spring, which is pressed axially onto the clamping device relative to the axis of movement of the movable tool or preloads the clamping device in the direction of the tool counterpart.

[0037] The joining tool unit can be used to process, for example, a workpiece comprising exactly one workpiece layer. Alternatively, the joining tool unit can be used to process, for example, a workpiece comprising two or more workpiece layers, which during processing are in contact with one another in the region of a joint that can be produced by means of the joining tool unit. The workpiece layers can be connected to one another by means of the joining tool unit during the joining process, for example by means of a joining connection, and / or the joining element or joining element can be placed on the workpiece by means of the joining tool unit.

[0038] The joining tool unit is advantageously designed for placing functional elements, such as punch nuts, rivet nuts, press-in nuts, pins, screw elements on workpieces and / or for press-fit connections or punch-fit connections and / or for placing rivets, such as collet rivets, full self-piercing rivets or semi-tubular self-piercing rivets. The joining tool unit can be used to rivet, crimp, punch or press-fit functional elements, for example, into workpieces.

[0039] With the joining tool unit, for example, a plurality of workpiece parts can be connected to one another, for example with connecting elements, such as rivets, or without connecting elements, for example by a press-fit connection process. With the joining tool unit, it is possible to place a functional element on a workpiece, for example, consisting of just one workpiece part.

[0040] Advantageously, material combinations or workpiece layers each consisting of different materials can also be processed by means of the described joining tool unit. For example, the respective workpiece layers can consist of one material, wherein the workpiece layers have mutually different technical properties, which relate, for example, to the formability, flowability, brittleness, toughness, strength, ductility or metallic content of the material. Preferably, the workpiece side or workpiece layer which is contacted and formed by the movable tool during the joining process is harder and / or more brittle than other workpiece layers which are located below or in the direction of the tool counterpart element.

[0041] The joining tool unit is designed, for example, to heat a workpiece layer whose material, for example, has a relatively high brittleness, i.e., tends to crack during forming, by means of a light beam impinging on the side of the workpiece, and on which the movable tool acts to process the workpiece, thereby briefly and strongly reducing the brittleness of the material.

[0042] The possibility of a targeted and defined or reliable light transmission to the workpiece by means of a light guide system and the heating of the workpiece area to be processed is advantageous. Due to the input of light energy by the light beam, the irradiated material is temporarily placed in a material state range that is advantageous in terms of forming, preferably enabling a softer or more fluid forming. At conventional workpiece temperatures, which are determined by the conventional ambient temperature at the processing location, for example in the range of about 15 to about 30 degrees Celsius, for example cracks may occur in the corresponding material, which result in the joint not meeting the requirements imposed on it, which is disadvantageous or leads to rejection.

[0043] Advantageously, the joining tool unit can be used to produce a joining connection with relatively very brittle materials, for example, a joining connection between a hard and / or brittle workpiece layer and a workpiece layer consisting of a relatively easy-to-form or softer material at a normal ambient temperature level in the range of, for example, 15 to 30 degrees Celsius.

[0044] It is also advantageous that not only the movable tool but also the tool counter-element performs a simultaneous movement away from or towards the workpiece. Advantageously, the workpiece is positioned between the movable tool and the tool counter-element in this case by a separate holding element.

[0045] The hold-down device can be designed alternatively to be used alone as a radiation shielding device and / or alone for guiding a light beam. The light beam is preferably a laser beam, wherein the laser beam can be continuous and / or pulsed. The light source is preferably a laser light source or a laser or a solid-state laser, a gas laser or a liquid laser. In addition, the light of the light beam can also be in the visible light range, the UV range and / or the IR range. Advantageously, the wavelength of the light provided by the light source matches the maximum absorptivity of the material to be processed of the workpiece or the workpiece layer, so that heat is input into the workpiece as energy-efficiently as possible by the light of the light source.

[0046] The light guide system is preferably configured in the clamping device so that the light guide system surrounds the light along the light beam, thereby shielding the light in a light-tight manner in a radial direction outward relative to the light beam by the light guide system. The light guide system includes, for example, a hollow groove in the clamping device, in which the light beam extends. The clamping device also has, for example, a recess, which is used as a placement and movement space for a movable tool. When the movable tool is a joint punch, the placement and movement space is, for example, a joint punch channel. The recess is, for example, cylindrical in the case of a cylindrical profile of the joint punch. The central longitudinal axis of the recess, for example, coincides with the moving axis of the movable tool. The light beam is tilted relative to the axis at an angle greater than 0° or greater than zero. Therefore, the hollow groove of the light guide system is tilted relative to the recess. The hollow groove or the light guide system of the light guide system can extend into the recess in the vicinity of the end side of the clamping device or near the free end of the clamping device in the clamping device. The exit port of the light guide system is, for example, present in the wall of the tool channel or the joint punch channel. However, the exit opening of the light guide system can also be separated from the channel of the tool, that is, in the end side of the clamping device, there is an opening in addition to the opening of the engaging punch channel. The light guide system then does not lead to the movement channel of the tool or to the engaging punch channel. The slot and the recess are two unconnected cavities in the clamping device or do not transition into each other.

[0047] The light guide system also includes the following arrangement, wherein the light guide system is present outside the clamping device, for example by means of a closed pipe, for example by means of the following pipe, which is placed outside the clamping device or partially extends outside the clamping device surface or exists close to the outside. It is also conceivable that the hollow groove is present on the clamping device in a tubular shape, for example as a tube.

[0048] It is also conceivable that the joining tool unit has a hold-down device on the tool counter-element and that the light-guiding system is formed on the hold-down device on the workpiece counter-element.

[0049] Preferably, there is a completely closed hollow groove, in particular a cylindrical hollow groove, of the light guide system inside the clamping device, preferably on the circumference of the light guide axis, wherein the light can be guided in the direction of the workpiece along the cylindrical axis of the hollow groove, for example, the longitudinal extension of the hollow groove. The hollow groove is, for example, surrounded by the material of the clamping device extending onto the hollow groove. The hollow groove is, for example, present on the clamping device as a hole, for example, as a through hole. However, it is also conceivable that the light guide system has glass fibers, and the glass fibers are fixed on or in the clamping device, which can, for example, be partially hollow.

[0050] The joining tool unit is operated by means of a control unit, which is, for example, part of the joining tool unit. The control unit is designed to control and / or regulate the drive unit, wherein the control unit is designed to control and / or regulate the light source and / or components of the light guide system.

[0051] In addition, it is proposed that the control unit of the joining tool unit is configured to end the irradiation or illumination of the joining portion of the arranged workpieces with the light of the light source at the same time as the movable tool starts to move or after the movable tool starts to move. As a result, the joining cycle time is relatively shortened. It is conceivable that the irradiation or illumination of the joining portion of the arranged workpieces with the light of the light source is ended before the movable tool starts to move.

[0052] For example, the control unit is designed to switch off the light source and thereby terminate the irradiation or illumination of the arranged joining point of the workpieces with the light of the light source simultaneously with or temporally after the movable tool begins to move.

[0053] For example, with regard to a joining process of workpieces by means of the joining tool unit, the joining tool unit is designed to initiate a movement of the movable tool in the direction of the tool counter element and simultaneously or temporally terminate the irradiation or illumination of the joining location with light.

[0054] Furthermore, it can be provided that the joining tool unit has a sensor unit, wherein the joining tool unit is configured to detect, by means of the sensor unit, for example, whether the hold-down device is in this position against the workpiece. For this purpose, the sensor unit comprises, for example, a pressure sensor which detects the dynamic pressure inside the hold-down device.

[0055] For example, the sensor unit is configured to determine whether the hold-down device is in this position against the workpiece to such an extent that the light beam or the light source is shielded from the outside in a light-tight manner by the hold-down device against the workpiece in such a way that a danger to workers in the surrounding area of ​​the joining tool unit can be eliminated. For example, the sensor unit detects the dynamic pressure of a fluid, such as air, by means of a sensor or a pressure sensor of the sensor unit, which fluid is present or included between the hold-down device and the workpiece. Before the activation of the light beam, the fluid is input into the flow channel, for example, via an inlet for the fluid. The flow channel for the fluid is, for example, at least partially formed by a light guide system or by a light guide channel of a light guide system.

[0056] The sensor may alternatively measure energy, temperature or the amount of light, for example.

[0057] For example, the joining tool unit checks, in particular by means of the control unit, whether the sensor value measured by the sensor unit is within a predetermined nominal range before the irradiation or illumination of the joining location of the arranged workpieces by means of the light of the light source begins and / or before the movable tool begins to move. If the measured sensor value is not within the predetermined nominal range, the joining tool unit, in particular by means of the control unit, blocks the start of irradiation or illumination of the joining location of the arranged workpieces by means of the light of the light source and / or the start of movement of the movable tool.

[0058] The clamping device is advantageously elongated in shape and advantageously matches the placement of the light guide system therein. The clamping device, for example, comprises an outer side with a peripheral side, wherein the peripheral side extends between a free end of the clamping device and a rear end facing away from the free end, wherein the peripheral side comprises a first partial region and a second partial region, each extending over the axial length of the clamping device, wherein the partial regions are radially opposed relative to the joint axis, wherein the first partial region has a flat outer contour, wherein on a cross section of the clamping device perpendicular to the joint axis of the first partial region, within an angular range of at least 10 degrees, a radial spacing relative to the joint axis is smaller than a radial spacing relative to the joint axis of the second partial region on the same cross section.

[0059] For example, the cross section has a surface shape with a surface edge such that the center of gravity of the cross section is offset relative to the intersection point of the cross section with the joining axis, in particular in the direction of the second subregion.

[0060] The relevant center of gravity is offset relative to the joining axis, wherein the first sub-region is diametrically opposed to the second sub-region. Preferably, a point of the first sub-region is diametrically opposed to a point of the second sub-region. The azimuthal extension of the sub-region is, for example, such that the angular range to which the first sub-region belongs spans, for example, less than 90 degrees.

[0061] The outer peripheral side of the outside of the clamping device has a convex shape or outer contour, such as a convex shape, in the second part area, for example. The light guide system is preferably placed in this volume area up to the joint axis or through the cross section of the joint axis. The outer shape or outer contour surrounding the first part area of ​​the peripheral side is, for example, so flat on the outside or so reduced in material that sufficient, but for example, minimum component strength is ensured. With the flat side of the outside of the clamping device, it is advantageously possible to achieve that the front end part of the joint tool unit can also reach the narrow part on the workpiece well or reach the component where the joint part should be set in a cramped environment, and the front end part terminates by the end side of the clamping device.

[0062] For example, a further, for example a second, hollow slot is present on the hold-down device. It is conceivable that the second hollow slot is present on the hold-down device in a mirror-symmetrical manner with respect to the first hollow slot. Preferably, the mirror axis extends parallel to the axis of movement of the movable tool. If the axis of movement of the movable tool extends, for example, centrally through the hold-down device, the axis of movement preferably corresponds to the mirror axis.

[0063] For example, the first and second slots are configured on the clamping device such that when the clamping device is pressed against the workpiece, the light of the light source is guided along the first slot to the workpiece, and the light of the light source reflected by the workpiece is guided along the second slot. The clamping device includes, for example, a beam catcher or beam trap, in which the reflected light is captured and absorbed. By guiding the light beam along the first and second slots in the clamping device, the protective cabin can be eliminated.

[0064] It is also conceivable that the light guide system has a shutter or an optical shutter, i.e., for example, a mechanical shutter or an electronic shutter. For example, the shutter can be used to activate or stop the irradiation of the joint by the light of the light source. The shutter has, for example, a movable element. Advantageously, the shutter can be controlled by means of a control unit, or the movable element can be manipulated. For example, a movable element made of an opaque material can be brought into the path of the light beam to block the light beam and can then be moved out again.

[0065] Advantageously, the holding down device is designed so that, in the state where the workpiece is arranged on the joining tool unit, the holding down device can be arranged against the surface of the workpiece in such a way that the holding down device surrounds the joining point of the workpiece so that a maximum of 20% of the radiated power of the light is emitted outwards between the holding down device and the surface of the workpiece. The light emitted outwards passes through at least one gap between the end face of the holding down device and the opposite surface of the workpiece. The maximum of 20% of the radiated power of the light preferably refers to the light power that is emitted in the direction of the surface of the workpiece before the holding down device at the exit position of the light beam.

[0066] The clamping device is preferably constructed so that a maximum of 10% of the radiant power of the light is emitted outward between the clamping device and the surface of the workpiece, or a maximum of 5% of the radiant power of the light is emitted outward between the clamping device and the surface of the workpiece, or a maximum of 3% of the radiant power of the light is emitted outward between the clamping device and the surface of the workpiece, preferably 0% of the radiant power of the light is emitted outward between the clamping device and the surface of the workpiece.

[0067] Usually the surface of the workpiece in contact with the hold-down device is flat and flatly constructed. Therefore, the side of the hold-down device facing the tool counterpart, such as the end side of the hold-down device, is also flat and planarly constructed, and this side contacts the workpiece when the workpiece is arranged. The end side preferably has a relatively very small roughness. In addition, it is advantageous that the end side of the hold-down device at least provides a flat and flat surface. The surface of the end side is for example smoothed or polished. The hold-down device-end side is preferably composed of a relatively mechanically durable or anti-deformation material, for example a hard metal or hard steel material.

[0068] In practice, even under the actual optimal conditions, in the state where the hold down device is placed in the workpiece, the small part of the light beam also appears as scattered light. Because it is usually impossible to realize that the section of the hold down device and the section of the surface of the workpiece are absolutely flat or it is impossible to realize that the hold down device is accurately placed vertically on the workpiece surface. Thus in practice, in the state arranged on the workpiece, there is usually a gap area between the hold down device surface or the end surface of the hold down device and the workpiece surface, and the gap area has a small gap width in the range of for example one tenth of a millimeter. The part of scattered light can be projected outwardly into the surrounding environment of the joining tool unit through the gap between the surface of the hold down device or its end side and the workpiece. The gap can exist due to the unevenness of two opposing faces on the hold down device and the workpiece, for example, particularly point-shaped recesses or projections and / or for example, between the hold down device end side and the workpiece surface, the non-parallel orientation of the opposing faces is produced.

[0069] The radiation power on which the outward radiation is based is, for example, the radiation power of light emitted from an opening of the light guide system of the pressing device and emitted to the joint, or the radiation power of light reaching the joint.

[0070] The radiant power on which it is based can alternatively be the radiant power provided by means of the light source, for example a rated power of the light source.

[0071] As a possible measure for limiting the radiation power of the light emitted outwards, emitted outwards between the holding-down device or its end face and the opposing surface of the workpiece, to a maximum of 20%, a power limitation of the light power generated by the light source can be achieved, for example, by means of a control device of the light source. Preferably, the power limitation is set in such a way that at least 80%, preferably at least 95%, of the light with respect to a reference value or a reference power of the light or light beam is shielded outwards.

[0072] Advantageously, the light guide system is present on the clamping device in such a way that the light beam impinges on the joining part of the workpiece only within an angle range of between 5° and 40° relative to the axis of motion of the linearly movable tool. This allows structural and / or manufacturing advantages to be achieved.

[0073] For example, the light beam is incident on the joint of the workpieces within an angle range of 5° to 40° relative to the axis of motion of the linearly movable tool, or for example, between 5° and 30°, or for example, between 10° and 30°, or for example, between 10° and 40°, or for example, between 5° and 10° relative to the axis of motion of the movable tool. For example, the light beam is incident on the joint of the workpieces at an angle of 4°, 4.5°; 5°; 5.5°; 6°; 7°; 8°; 9° or 10° relative to the axis of motion of the movable tool.

[0074] An adjustment device for adjusting the angle range is conceivable, by means of which the light beam is adjusted relative to the axis of movement of the linearly movable tool, for example, between an angle greater than zero degrees and less than 40 degrees.

[0075] Preferably, the angle of incidence is as small as possible or as steep as possible relative to the axis of movement of the linearly movable tool.

[0076] Preferably, the diameter of the beam, for example the diameter of the laser beam, is adjustable. For this purpose, an adjustment device, for example for manually adjusting the laser diameter, is preferably provided on the joining tool unit.

[0077] According to an advantageous variant, the linearly movable tool is configured as a joining punch. The joining punch is at least partially movably guided in a clamping device. The clamping device circumferentially surrounds the joining punch over the axial length of the joining punch. The joining punch is used to join workpieces, which are composed of a formable material. The joining punch is preferably a joining punch for press-fit connection or stamping connection, wherein, in cooperation with a tool counterpart, such as a press-fit bottom die, the joining punch deforms the material of the workpiece by the driven movement of the joining punch along the movement direction of the joining punch toward the tool counterpart. Therefore, the joining tool unit is preferably a press-fit connection tool unit. In a press-fit connection, the workpiece is usually two-sided or multi-layered.

[0078] In order to attach the connecting or functional element to the workpiece, the joining punch acts via corresponding elements on the region of the workpiece which is deformed in the process and softened by the beam.

[0079] It is also conceivable that the linearly movable tool is designed as a bottom die tool different from the joining punch tool or as part of the bottom die unit. The linearly movable tool is, for example, a bottom die tool part, for example an inner part of the bottom die unit, which is, for example, surrounded by a bottom die support portion of the bottom die. The bottom die support portion is, for example, designed as a clamping device of the bottom die unit. Preferably, the light guide system can be arranged in the clamping device of the bottom die unit as described above for the clamping device.

[0080] Another advantage is that the tool counter-element has a movable second tool. The movable second tool is therefore a different tool or a movable second tool than the movable first tool in the hold-down device, for example a joining punch. The movable second tool is, for example, present only in a linearly movable manner. For example, when the tool counter-element comprises a die unit, the movable second tool is, for example, surrounded by the second hold-down device on the die side or is part of the die unit. The movable first tool is, for example, surrounded by the first hold-down device.

[0081] The light guide system is present on or in the first hold-down device and / or the second hold-down device. As a result, the workpiece can be subjected to a light beam from the first side, from the second side or from both sides, for example heated by means of a laser beam. As a result, workpieces that are composed of different materials in combination can be heated and softened by means of a light beam before joining.

[0082] In addition, it is advantageous that there is another light guide system, for example the second light guide system, on the tool corresponding element, to guide the light towards the direction of another surface of the workpiece, wherein the workpiece is placed on the tool corresponding element with a section of another surface at least.Efficiently realize that the energy or light quantity that is expected or compared with the independent or one-sided light radiation through the hold down device is larger is applied to the workpiece in the region of the joint.It is also possible that, compared with the independent light radiation sent from the first light guide system or the hold down device one side, the corresponding energy is transmitted to the workpiece in a shorter time.The workpiece side belonging to another surface of the workpiece can be heated thus equally advantageously, which is conducive to deforming the material of the workpiece by, for example, being pressed into the tool corresponding element by the heated material on one side of the workpiece corresponding element.The additional energy inputting a certain proportion on one side of the tool corresponding element also can cause the side of the workpiece contacted with the hold down device to continue or be further heated, which is realized by the heat conduction inside the workpiece.

[0083] Due to the, for example, very limited action time provided for heating the workpiece, relatively intensive heating can be achieved and undesired cooling of the workpiece below a critical temperature value in the region of the joint after switching off the light radiation until the start of deformation can be prevented.

[0084] Heating the workpiece on the tool counter-element side is advantageous in the case of relatively brittle materials on the workpiece counter-element side or in the case of material joining or deformation on this side which is prone to cracking.

[0085] The other surface of the workpiece is thus, for example, a side surface facing the tool counter-element, for example, a surface on the back side of the workpiece, which surface is in contact with the tool counter-element before and during processing by the joining tool unit. The surface on the back side of the workpiece is opposite to the surface on the front side of the workpiece, wherein the surface on the front side of the workpiece can be in contact with the clamping device or is in contact with the clamping device when the joining tool unit is arranged on the workpiece. This relates accordingly to the area of ​​the workpiece including the joining location, which is present after processing the workpiece by the joining tool unit.

[0086] The tool counter-element is, for example, constructed as a die unit, which has a movable or immovable tool or die tool of the die unit and a die support portion. The die support portion is, for example, a part that surrounds the die tool, such as a die clamping device having a light guide system. The die support portion is, for example, a die clamping device corresponding to the characteristics of the clamping device or corresponding to the opposite clamping device, such as a joining punch clamping device. The die clamping device or the die support portion preferably has a light guide system, which is constructed to guide a light beam toward the joining portion of the workpiece facing the tool counter-element when the workpiece is arranged on the joining tool unit, wherein the light guide system is present on the die support portion in such a way that the light beam is incident on the joining portion only at an angle greater than 0° relative to the axis of movement of the tool of the workpiece counter-element, wherein the light guide system of the die support portion shields the light along its light beam to the outside in a light-proof manner. The workpiece has, for example, a joining point facing the tool, for example a joining punch tool, for example on the workpiece top side, and an opposing joining point facing the tool counter-element, for example on the workpiece bottom side of the workpiece.

[0087] Advantageously, the clamping device is configured as a clamping device of a joining punch unit or a clamping device of a bottom die unit. Thus, it is possible to work very flexibly and in matching manner. It is possible that, preferably, a light beam effect on the workpiece is optionally provided on both sides or on a single side. Thus, for example, the workpiece or the corresponding surface can be heated or softened on both sides, for example, on the upper side and on the lower side, which is directly carried out before the joining process, because otherwise the cooling of the joining part material and the hardening thereof that follows occur. By means of a light guide system in the clamping device of the joining punch unit or in the clamping device of the bottom die unit, light or a light beam can be applied to the region of the subsequent joining part on the upper side and / or the lower side of the workpiece in a targeted, controlled and reliable manner. Compared with the radiation of the workpiece on one side, when on both sides and when irradiated simultaneously, relatively more energy can be input into the workpiece in the region of the joining part in the same time, for example. When the workpiece consists of multiple workpiece layers, for example two layers or more, which are respectively composed of different materials for the corresponding workpiece layers, it is also advantageously possible to apply energy or heat to the workpiece on both sides or on one side or only from one side of the joining punch unit or only from one side of the base die unit or from both sides in a very flexible manner and matched to the corresponding material pair or material combination.

[0088] In principle, the workpiece is present in the corresponding workpiece layers between the tool and the tool counterpart or between the punch unit and the base die unit. Since the technical properties of the corresponding workpiece layers may be partially different due to possible different materials, it is advantageous to flexibly carry out single-sided or double-sided radiation. However, in the case where the workpiece layer on the joining punch unit and the workpiece layer on the base die unit have similar material properties, the possible arrangement of the clamping device with the corresponding light guide system on both sides is also advantageous. In particular, due to the relatively high energy required in a short time, it is preferred to respectively arrange the light source on the joining punch side and / or the base die side and the corresponding light guide system in the corresponding clamping device for this purpose. Advantageously, when heating is carried out on both sides of the workpiece, the cycle time can be shortened when the workpiece is processed.

[0089] Advantageously, the tool counter-element is designed as a die unit and the clamping device with the movable tool is a component of the joining punch unit. As a result, a proven C-frame tool with a punch unit and a die unit, for example, can be optimized or equipped with a light guide system. As a result, for example, press-fitting tools or riveting tools can be advantageously used for workpieces made of an ever-increasing variety of materials that could not previously be processed with them.

[0090] It is also conceivable that the tool counter-element is designed to engage the punch unit and that the hold-down device with the movable tool is a component of the die unit.

[0091] The present invention advantageously relates to a tool pliers having a joining tool unit as described in any one of the aforementioned embodiments and a tool holder. Preferably, the tool pliers comprises a C-shaped holder.

[0092] It is conceivable that the tool pliers are configured as pressing pliers, joining pliers and / or punching pliers. It is also conceivable that the tool pliers exist as semi-hollow self-piercing rivet pliers and / or full self-piercing rivet pliers.

[0093] Advantageously, the configuration of the tool pliers with a clamping device and a light-guiding system can be realized relatively easily. For example, the known tool pliers can be constructed economically and technically advantageously. The basic structure of the known tool pliers is advantageously maintained. A clamping device and a light beam transmission device must then be provided. Other components are, for example, light sources, pipeline components and transmission components for light, and other operating devices, for example for cooling and cleaning, or safety components. These components can, for example, be arranged at a certain distance from the joining punch unit and the bottom die unit.

[0094] For example, a gas or air flow flowing in or along the joining tool unit can be used to flush or apply to the joining tool unit or the lines of the light guide system in the area of ​​the light guide system, for example to minimize or eliminate contamination or to cool the area of ​​the holding device that is heated by the light beam. This can be done before and / or during and / or after guiding the light through the light guide system.

[0095] A process for joining workpieces by means of a joining tool unit is also proposed, for example a process for joining workpieces by means of a joining tool unit according to any of the embodiments described above, wherein the joining process comprises the following method steps:

[0096] - arranging the workpiece to be processed on the joining tool unit,

[0097] - moving the hold-down device of the joining tool unit relative to the tool counterpart of the joining tool unit to a position in which the hold-down device and the tool counterpart are in contact with the workpiece,

[0098] - keep the hold-down device in this position,

[0099] When the holding down device has reached this position, the irradiation or illumination of the joining location of the workpieces with the light of the light source of the joining tool unit is started.

[0100] It is further proposed that the joining process may include one of the following further method steps:

[0101] - detecting the position of the hold-down device by means of a sensor unit of the engagement tool unit,

[0102] - based on the detection by the sensor unit, a check is made by the control unit of the joining tool as to whether the holding-down device has reached this position,

[0103] - starting to move the movable tool of the joining tool unit in the direction of the joining location of the workpieces to join the workpieces,

[0104] - terminating the irradiation or radiation of the joining part of the workpieces simultaneously with or after the start of the movement of the movable tool of the joining tool unit in the direction of the joining part of the workpieces,

[0105] - checking by means of the joining tool unit whether, during the joining process of the workpieces by means of the movable tool, the irradiation or radiation of the areas of the workpieces to be joined has been completed,

[0106] - before the clamping device is moved away from the position, the workpieces are engaged by means of a movable tool,

[0107] - after the movable tool has started to move in the direction of the region of the workpieces to be joined, moving the holding device away from this position,

[0108] The joining tool unit checks whether the irradiation or radiation of the region of the workpieces to be joined has been completed before the hold-down device is moved away from this position.

[0109] On the one hand, a safety function is thus provided, in particular to exclude danger to workers, and on the other hand, in particular undesirable heating of the movable tool can be controlled thereby. BRIEF DESCRIPTION OF THE DRAWINGS

[0110] Details and advantages of an exemplary embodiment will be explained in more detail with reference to the following figures.

[0111] In the attached figure:

[0112] Figure 1 A perspective view of a tool pliers having a joining tool unit is shown, viewed obliquely from above.

[0113] Figure 2 A perspective view showing part of a joining tool unit,

[0114] Figure 3 Show according to Figure 2 A further perspective view of a portion of a joining tool unit,

[0115] Figure 4 Show according to Figure 1 sectional view of a portion of a joining tool unit, wherein the joining tool unit with a holding-down device and a tool counter element rests on a workpiece, wherein the course of the light beam is shown,

[0116] Figure 5 Show according to Figure 4 A cross-sectional view of an assembly of FIG. 1 , wherein the direction of the air flow is shown,

[0117] Figure 6 A cross-sectional view showing a portion of a bonding tool unit with a temperature gauge,

[0118] Figure 7 Show according to Figure 4 and 5 A cross-sectional view of an assembly in which a joining connection is produced on the workpieces,

[0119] Figure 8 The diagram shows the initial position after the joint connection has been established. Figure 4 , 5 and 7 are cross-sectional views of the components. DETAILED DESCRIPTION

[0120] exist Figure 12 shows a tool pliers 1 with a joining tool unit 2. The tool pliers 1 have a tool holder 3, wherein the joining tool unit 2 or a tool counter element 4 of the joining tool unit 2 is arranged on the tool holder 3. The tool holder 3 is preferably designed as a C-frame and can be fixed, for example, by connecting elements 5. Figure 1 On a robotic arm not shown.

[0121] The joining tool unit 2 is provided with a tool counter-element 4, a pressing device 6, a movable tool 7 (see Figure 2 ), a drive unit 8, a light source 10 and a control unit 40. The light source 10 is connected to the remaining bonding tool units 2 at Figure 1 Not shown in FIG.

[0122] The drive unit 8 can be designed as an electric, pneumatic, hydraulic or hydropneumatic drive. The drive unit 8 is connected to the tool holder 3, for example.

[0123] For example, a movable tool 7, such as a joining punch or a pressing punch, a temperature measuring device 24 and a light guide system 9 are arranged on the pressing device 6. The light guide system 9 includes a collimator 11, a first mirror 12, a second mirror 13, a beam catcher 14 or a beam trap and a protective glass 15 (see Figure 4 ,7). The light source 10 is, for example, a laser light source or a laser, such as a fiber laser. The collimator 11 is preferably configured so that a collimated light beam is generated, such as a collimated laser beam. For example, the light beam of the light source 10 is first widened and oriented at least almost parallel to each other. The first mirror 12 can be adjusted, for example, so that the position of the light beam of the light source 10 or the position of the area irradiated by the light beam on the workpiece 25 to be processed can be adjusted. The second mirror 13 is preferably arranged on the bonding tool unit 2 in a fixed position. The protective glass 15 forms an isolation point between the optical device or mirror 12, 13 of the light guide system 9 and the collimator 11 and the clamping device 6. The beam diameter of the light beam can also be changed or adjusted by the adjusting element 26 on the outside of the bonding tool unit 2. A cooling body, such as a cooling plate 31, is preferably configured at the end of the beam catcher 14 or the beam trap, which cools or cools the beam catcher 14 or the beam trap and the surface adjacent to it in order to cool the area of ​​the bonding tool unit 2. The cooling plate 31 is preferably arranged detachably on the outer side of the hold-down device 6 , so that the cooling plate 31 can be replaced or cleaned, for example in the event of wear or soiling.

[0124] The joining tool unit 2 preferably has slots 16, 17 to couple, for example, plug and unplug, the light source 10 to the joining tool unit 2. For example, slots 18, 19 for the suction pipe 20 and slots 21, 22 for the inlet 23 are also provided on the joining tool unit (see Figure 8), whereby a fluid can flow in at the inlet 23 or be sucked in at the suction pipe 20. The fluid is, for example, a gas, such as air, in particular, air that has been freed of particles in an ideal case. The fluid is present, for example, as a purified, particle-free gas. It is also conceivable that the fluid is present as a specific gas, such as nitrogen or carbon dioxide.

[0125] Standard tool pliers, such as pressing pliers, can be equipped with parts of the joining tool unit 2, in particular the clamping device 6 and the light guide system 9, for example, in that the clamping device 6 and the light guide system 9 are connected to the drive unit 8, which is preferably arranged on the tool holder 3. The joining tool unit 2 preferably has a fixing element 27 for this purpose, wherein parts of the joining tool unit 2, in particular the parts of the joining tool unit 2 that are configured with the slots 16, 17, 18, 19, 21, 22, can be connected to the drive unit 8 via the fixing element 27. The clamping device 6 also has a connecting element 29 for connecting to the drive device 8. The fixing element 27 is preferably made of a plate-shaped material, in particular a metal. The fixing element 27 can be connected to the drive unit 8 via a fixing part 30, such as a screw with a screw. A safety switch 28 is arranged on the fixing element 27, for example.

[0126] exist Figure 4 , 5 , 6, 7 and 8 show cross-sectional views of parts of the joining tool unit 2. The light beam of the light source is coupled into the light guide system 9 in the region 41 by the light source 10. The course of the light beam is Figure 4 This is schematically shown by arrow L. A light beam, for example, Figure 4 1 , the light beam L reaches the region 41 and further reaches the collimator 11, wherein the light beam is then reflected, for example, on the first mirror 12 and on the second mirror 13 and passes through the protective glass 15, for example, to the holding down device 6. A first recess 32 is formed on the holding down device 6, wherein the first recess 32 is, for example, a hole in the holding down device 6. For example, the light beam L passes through the first recess 32 to the recess 33, which is formed open on the end of the holding down device 6 on the workpiece side. If the holding down device 6 is placed on the workpiece 25, the light beam is reflected on the preferably metallic workpiece surface 42 of the workpiece 25 (except for the part of the light beam that is absorbed by the material of the workpiece) and reaches the second recess 34, which is formed, for example, as a hole in the holding down device 6. A beam catcher 14 or a beam trap is formed along the second recess and / or at the end of the second recess 34, so that the light beam L reflected by the workpiece 25 is received and absorbed in the beam catcher 14 or the beam trap.

[0127] For example, a further hole for the movable tool 7 is provided on the clamping device 6 so that the movable tool 7 can be moved linearly along the displacement axis 35 in the direction of the workpiece 25. The hole and the recess 32, 34, for example, merge into each other. The displacement axis 35 preferably extends along the longitudinal extension of the movable tool 7 (see Figure 6 ). The displacement axis 35 also extends, for example, centrally through the movable tool 7. Furthermore, the displacement axis 35 extends, for example, centrally through the movable tool 7. The longitudinal axis of the first recess 32 or the second recess 34 is present on the hold-down device 6, for example, within an angle range α between 5° and 40° relative to the displacement axis 35 of the movable tool 7. Preferably, the second recess 34 is designed mirror-symmetrically to the first recess 32, wherein the displacement axis 35 is, for example, a component of a mirror plane or the mirror plane intersects the displacement axis along its length.

[0128] For example, a part of the light guide system 8 forms the flow channel 38. For example, the first and second recesses 32, 34 and the recess 33 of the light guide system 8 form parts of the flow channel 38. The recess 33 has a depth of a few millimeters, for example between 1 and 7 millimeters, in the direction of the displacement axis 35. The flow channel 38 extends, for example, mainly along the light guide system 8 or coincides with the light guide system, wherein the flow channel 38 starts only after the collimator 11. The flow channel 38 also has a further, second recess 36, which is preferably designed as a hole. For example, the second recess 36 is connected to a section of the second recess 34 and extends parallel to the displacement axis 35 of the movable tool 7. A fluid, for example air, enters the flow channel 38 via the inlet 23 and can flow along the flow channel 38. For example, the fluid accumulates after the collimator 11 as far as the region of the protective glass 15 through which the fluid cannot pass, as viewed in the flow direction, because the fluid can only flow to the first recess 32 next to the outside of the protective glass 15 through the constriction in the flow channel. Thus, at least as long as the fluid flows in through the inlet 23, an overpressure is generated in the area behind the collimator 11 up to the protective glass 15. For example, the fluid flows in continuously via the inlet 23 so that it flows through the elements or mirrors 12, 13 of the optical device and keeps them clean. The fluid can flow from the flow channel 38 through the recess 33 and the second outlet 37. The second outlet 37 is preferably arranged at the end of the recess 36, wherein the second outlet 37 is connected to the suction tube 20, for example, so that the fluid flowing into the recess 36 can be sucked out at the end of the recess 36. For example, the suction tube 20 is arranged on the flow channel 38, by which the fluid can be sucked out of the flow channel 38.

[0129] For example, the fluid enters the flow channel 32 through the inlet 23 at least during the entire time course of the joining process, wherein the fluid flows out of the recess 33 as long as the clamping device 6 does not rest on the workpiece 25. For example, for a joining process, the joining tool unit 2 is first moved in the direction of the workpiece 25 to be processed until the clamping device 6 and the workpiece counter element 4 rest against the workpiece. As soon as the clamping device 6 rests on the workpiece 2, the drive device 8 moves the movable tool 7 along the movement axis 35 in the direction of the workpiece 25 according to the Figure 5 This situation is the initial position of the movable tool 7. Therefore, the spacing between the movable tool 7 and the workpiece 25 is minimized, so that the movable tool 7 and the workpiece 25 are separated by a relatively short distance.

[0130] For example, by moving the movable tool 7 by the drive device 8, the spring element is loaded and the clamping device 6 is pressed against the workpiece 25 by means of the force provided by the spring element. The clamping device 6 is thereby pressed, in particular, against the workpiece 25, so that light is prevented from escaping between the clamping device 6 and the workpiece 25 or an outward light opacity of zero to, for example, 10% is achieved. The relatively large pressing force of the clamping device 6 on the surface of the workpiece 25 that rests on the clamping device 6 can also better transfer heat from a first workpiece part of the workpiece 25, for example a first workpiece layer in contact with the clamping device, to a second workpiece part of the workpiece 25 or a second workpiece layer that rests on the tool counter element 4.

[0131] Then, for example, a check is performed to determine whether the hold-down device 6 is resting on the workpiece 25 as desired. For this purpose, for example, the position of the movable tool 7 is first determined by the control unit 40. For example, the position of the safety switch 28 is also determined, and the position of the hold-down device and the light guide system 9 is checked therefrom. For example, after these two checks confirm the setpoint state or provide the expected result and are recognized as correct, the pressure in the flow channel 38 is determined.

[0132] For example, to determine the pressure, the second outlet 37 or the valve leading to the pump on the suction line 20 is closed (see Figure 4). Therefore, when the recess 33 on the hold-down device 6 is covered by the workpiece 25 and when the flow channel 38 or the light guide system 9 is not damaged, the fluid accumulates inside the flow channel 38. For example, the pressure in the flow channel 38 is measured by a sensor (not shown), such as a pressure sensor. The information of the fluid pressure or gas pressure measured by the sensor is transmitted to the control unit 40, wherein the control unit 40 compares the pressure measured by the sensor with a predetermined threshold value or a rated range. The threshold value is preferably selected so that even in the case of a narrow gap between the hold-down device 6 and the workpiece 25, the pressure in the flow channel 38 measured by the sensor cannot exceed the threshold value. It is thus ensured that only when the hold-down device 6 is expected, for example, vertically placed on the workpiece 25, can the light source 10 be activated, so that no light radiation or light radiation or laser radiation dangerous to people is emitted outward.

[0133] For example, after checking the pressure in the flow channel 3, the second outlet and / or the valve of the pump leading to the suction line is opened, so that a flow is generated again in the flow channel 38 (see Figure 5 , arrow). The fluid thus flows from the inlet 23 to the second mirror 13, to the protective glass 15, along the first recess 32 to the second recess 34, along the recess 36 to the second outlet 37 and is drawn off at the second outlet 37. Thus, by the flow in the flow channel 38, for example, deposits and dirt on the mirrors 12, 13 are removed from the flow channel 38.

[0134] For example, as soon as a flow is generated in the flow channel 38, the control unit activates the light source 10. For example, the workpiece 25 is heated by the light beam of the light source 10, wherein, in particular when the surface has not yet been heated, part of the light beam is reflected on the workpiece 25. The direction of the light beam is indicated by the arrow L (see Figure 5 ). The reflected light beam reaches the beam catcher 14 or beam trap along the second recess 34. Radiation protection is thus ensured without an additional radiation protection cabin that covers the tool tongs 1.

[0135] For example, the temperature on the workpiece is measured by a thermometer 24 (see Figure 6). The thermometer 24 is arranged on the clamping device 6, wherein the hole 39 required for temperature measurement is constructed on the clamping device 6. The hole 39 is present on the clamping device 6 with respect to the first slot 32, which is rotated 90° around the moving axis 35, for example, 90 degrees. Therefore, the thermal radiation emitted by the heated workpiece 25 can reach the thermometer 24 through the hole 39. The current or current temperature of the workpiece 25, in particular the temperature of the surface of the workpiece 25 at the joint of the workpiece, is thus determined. For example, the thermometer 24 transmits the measured temperature to the control unit 40, wherein the rated temperature or the temperature to be reached is stored in the control unit 40 and compared with the current workpiece surface temperature measurement value. For example, a plurality of different temperatures to be reached for correspondingly different materials are present or stored in the control unit. For example, if the temperature to be reached is reached before a determined duration, the light source 10 is deactivated or the joining process is started in advance. If the temperature to be reached cannot be reached within a determined duration, the joining process is canceled or other method steps are introduced, for example.

[0136] For example, in particular, immediately before, simultaneously with, or after the light source 10 is turned off, the movable tool 7 is started to move in the direction of the tool counterpart element 4, so that the workpiece 25 is joined at the joining position ( Figure 7 ). The control unit 40 is configured, for example, to check whether the light source 10 and thus the irradiation of the workpiece 25 are deactivated when the movable tool 7 reaches the area of ​​the light path of the light beam of the light source 10 in the direction of the tool counterpart element 4 on its path. It should therefore be prevented that the movable tool 7 is heated undesirably by the radiation of the light beam of the light source 10. The safety of the workers at the joining tool unit 2 or in the area near the joining tool unit should also be ensured. However, it can also be designed that the control unit first checks whether the light source 10 and thus the irradiation of the workpiece 25 are deactivated and only activates the movement of the movable tool 7 toward the workpiece 25 after checking that the light source 10 is turned off.

[0137] For example, during the establishment of the joint connection, a flow of fluid in the flow channel 38 is maintained in particular continuously, so that dirt generated during the establishment of the joint connection can be entrained and transported away by the fluid flow (see Figure 5 ).

[0138] For example, the movable tool 7 moves back to the position according to the Figure 4 The second outlet 37 is then closed, for example. For example, the joining tool unit 2, in particular the holding-down device 6, is then moved away from the workpiece 25 by the drive device 8. For example, the fluid continuously flows through the inlet 23 in the direction of the recess 33, so that even during downtime, the optical device, for example an optical element, such as the mirror 12, 13, is not contaminated.

[0139] List of Reference Numerals

[0140] 1 Pliers

[0141] 2 Joining tool unit

[0142] 3 Tool Rack

[0143] 4 Tool corresponding components

[0144] 5 Connecting elements

[0145] 6. Clamping device

[0146] 7 Tools

[0147] 8 Drivers

[0148] 9 Light guide system

[0149] 10 Light Source

[0150] 11 Collimator

[0151] 12 Mirror

[0152] 13 Mirror

[0153] 14 Beam catcher

[0154] 15 Protective glass

[0155] 16 slots

[0156] 17 slots

[0157] 18 slots

[0158] 19 slots

[0159] 20 Suction tube

[0160] 21 slots

[0161] 22 slots

[0162] 23 Entrance

[0163] 24 Thermometer

[0164] 25 Workpiece

[0165] 26 Adjustment element

[0166] 27 Fixing elements

[0167] 28 Safety switch

[0168] 29 Connecting elements

[0169] 30 Fixing parts

[0170] 31 Cooling Plate

[0171] 32 empty slots

[0172] 33 Notch

[0173] 34 empty slots

[0174] 35 Moving axis

[0175] 36 Notch

[0176] 37 Exit

[0177] 38 Flow Channels

[0178] 39 holes

[0179] 40 Control Unit

[0180] 41 Area

[0181] 42 Workpiece surface.

Claims

1. A joining tool unit (2), wherein: The joining tool unit (2) comprises a clamping device (6) having a linearly movable tool (7) and a tool-countering element (4), wherein the clamping device (6) having the linearly movable tool (7) is located opposite to the tool-countering element (4), wherein a workpiece (25) is placed against the tool-countering element (4) when arranged on the joining tool unit (2), wherein the clamping device (6) can be placed against the surface of the workpiece (25) when the workpiece (25) is arranged on the joining tool unit (2), wherein the clamping device (6) has a light-guiding system (9), wherein the light-guiding system (9) is configured to direct a light beam toward the workpiece (25) when the workpiece (25) is arranged on the joining tool unit (2). The invention relates to a method for guiding a light beam in the direction of a joint of a workpiece (25), wherein the light-guiding system (9) is present on the clamping device (6) so that the light beam is incident on the joint only at an angle greater than 0° relative to the movement axis (35) of the linearly movable tool (7), wherein the light-guiding system (9) of the clamping device (6) shields the light along its light beam outwardly in a light-proof manner, wherein the light-guiding system (9) is integrated in the clamping device (6) so that the light beam can be guided directly onto the workpiece (25), wherein the light-proof shielding performed by the light-guiding system at the clamping device (6) is arranged based on a pipeline of the light-guiding system (9) that is machined out of the solid material of the clamping device (6) and is inside the clamping device (6).

2. The joining tool unit (2) according to claim 1, characterized in that The clamping device (6) is constructed so that when the workpiece (25) is arranged on the joining tool unit (2), the clamping device (6) can be arranged against the surface of the workpiece (25) so that the clamping device (6) surrounds the joining location, so that a maximum of 20% of the radiation power of the light is emitted outward between the clamping device (6) and the surface.

3. The joining tool unit (2) according to claim 1 or claim 2, characterized in that: The light guide system (9) is present on the clamping device (6) so that the light beam is incident on the joining point of the workpiece (25) only within an angular range of between 5° and 40° relative to the displacement axis (35) of the linearly movable tool (7).

4. The joining tool unit (2) according to claim 1 or claim 2, characterized in that: The linearly movable tool (7) is designed as a joining punch.

5. The joining tool unit (2) according to claim 1 or claim 2, characterized in that: The tool counter-element (4) has a second movable tool.

6. The joining tool unit (2) according to claim 1 or claim 2, characterized in that: A further light guide system is present on the tool counterpart element (4) for guiding light in the direction of another surface or a back surface of the workpiece (25), wherein the workpiece (25) rests on the tool counterpart element (4) at least with a section of another back surface.

7. The joining tool unit (2) according to claim 1 or claim 2, characterized in that: The holding down device (6) is configured as a holding down device (6) of a joining punch unit or a holding down device (6) of a die unit.

8. The joining tool unit (2) according to claim 1 or claim 2, characterized in that: The tool counter-element is designed as a die unit and the hold-down device (6) with the linearly displaceable tool (7) is a component of a joining punch unit.

9. The joining tool unit (2) according to claim 6, characterized in that The additional light guiding system is a second light guiding system.

10. Tool pliers (1) having a joining tool unit (2) and a tool holder (3) according to any one of the preceding claims.

11. A joining process of workpieces (25) by means of a joining tool unit (2) according to any one of the preceding claims 1 to 9, comprising the following method steps which follow one another: - placing a workpiece (25) to be processed on the joining tool unit (2), - moving the holding down device (6) of the joining tool unit (2) relative to the tool counter-element (4) of the joining tool unit (2) to a position in which the holding down device (6) and the tool counter-element (4) are in contact with the workpiece (25), - holding the holding device (6) in this position, When the holding-down device (6) has reached this position, irradiation or illumination of the joining location of the workpiece (25) with the light of the light source (10) of the joining tool unit (2) is started.

12. The joining process according to claim 11, comprising the following further method steps: - starting to move the movable tool (7) of the joining tool unit (2) in the direction of the joining location of the workpieces (25) so as to join the workpieces (25).

13. The joining process according to claim 11 or claim 12, comprising the following further method steps: - terminating the irradiation or radiation of the joint of the workpiece (25), - moving the hold-down device (6) away from this position.

14. The joining process according to claim 11 or claim 12, comprising the following further method steps: - At the same time as the movable tool (7) of the joining tool unit (2) starts to move in the direction of the joining part of the workpiece (25) or after the movable tool (7) of the joining tool unit (2) starts to move in the direction of the joining part of the workpiece (25), the irradiation or radiation of the joining part of the workpiece (25) is terminated.

Images