DEVICE AND SYSTEM FOR WELDING OR BRAZING UNDER A SHIELDING GAS ATMOSPHERE AND METHOD FOR CONTROLLING AN EXTRACTION DEVICE OF SUCH DEVICE

Description

[0001] The invention relates to a device for welding or brazing under a protective gas atmosphere, comprising a power source for supplying a welding or brazing current, connection means for connecting a torch with integrated extraction, an extraction device for supplying an extraction airflow via the connection means, and a control device for controlling the extraction device. The invention further relates to a system for welding or brazing under a protective gas atmosphere comprising such a device. The invention further relates to a method for controlling an extraction device of a device for welding or brazing under a protective gas atmosphere.

[0002] The high temperatures that occur during welding or soldering lead to the formation of exhaust gases, especially fumes, some of which are harmful to health. To protect workers in the immediate vicinity of the welding process, it is necessary to extract these exhaust gases from the workplace before they mix with the ambient air.

[0003] A particular challenge in exhaust gas extraction arises when welding or brazing processes are carried out under a shielding gas atmosphere. For proper operation, it is essential that the shielding gas applied during the welding or brazing process securely covers the electrode and the workpiece at the point where material is melted. Otherwise, oxidation and other reactions can occur at this point, adversely affecting the quality of the weld or braze. If shielding gas is applied directly at or around the electrode that generates the arc, it is crucial to prevent disruptive air currents from dissipating the shielding gas in order to form a stable shielding layer.

[0004] Various methods and devices for controlling the extraction system of a welding apparatus are known from the prior art. For example, EP 2 292 367 B1, on which the preamble of claim 1 is based, discloses a method in which the extraction is controlled depending on process parameters of the welding process that are adjustable or preset on the welding apparatus and on additionally measured variables, such as the distance between the torch tip and the workpiece, namely, for example, the torch feed rate, the wire feed rate, or the wire diameter.

[0005] However, it has been shown that with such automatic control of the extraction system, relevant influencing factors for the extraction remain unconsidered.

[0006] From DE 10 2019 119 341 A1, a control system for an extraction device is known that depends on the position or changes in the position of the burner, which are determined by means of a suitable sensor in the burner. The position of the burner can be determined, for example, by distance measurements using an ultrasonic transmitter and a stationary receiver.

[0007] Against this background, the present invention aims to provide a method and a device that simplify and / or improve the control of the extraction system.

[0008] This problem is solved according to the invention by a device for welding or brazing under a protective gas atmosphere, comprising a power source for providing a welding or brazing current, connection means for connecting a torch with integrated extraction, an extraction device for providing an extraction airflow via the connection means, and a control device for controlling the extraction device, wherein the control device is configured to obtain distance information about the torch distance of a torch connected to the connection means to the welding or brazing point, depending on current welding or brazing parameters, and to control the extraction device depending on the determined distance information, see claim 1.

[0009] The aforementioned problem is solved according to the invention by a method for controlling an extraction device of a device for welding or brazing under a protective gas atmosphere, in particular the device described above or an embodiment thereof, in which distance information about the torch distance of a torch connected to the connection means to the welding or brazing point is determined and the extraction device is controlled depending on the determined distance information, wherein the distance information is determined depending on current welding or brazing parameters, see claim 10.

[0010] The device is designed for welding or brazing under a protective gas atmosphere. In particular, the device can be designed for metal inert gas welding (MIG welding), for example, metal inert gas welding (MIG welding) or metal active gas welding (MAG welding). Alternatively, the device can also be designed for use in tungsten inert gas welding (TIG welding) or plasma welding.

[0011] The device may include a power source, in particular a welding or soldering power source, for providing welding or soldering current. For example, the extraction system or the control unit of the device, or a part thereof, may be integrated into the power source. However, it is also conceivable that the device does not have a power source and a separate power source is used for welding or soldering.

[0012] The device can be used, for example, alone or together with other devices, such as a separate welding or soldering power source, for welding or soldering under a protective gas atmosphere.

[0013] The device can be housed in one or more enclosures. In particular, the device can comprise more than one unit, for example, a power source and a wire feeder, or a separate extraction unit and a wire feeder.

[0014] If the device has a power source for providing a welding or soldering current, this preferably includes a power section for providing the welding or soldering current and a control unit for controlling the power source.

[0015] The device further includes connection means for attaching a torch with integrated extraction. These connection means may, in particular, comprise one or more ports to which the torch's hose assembly can be connected for operation. The torch is preferably a hand-held torch. Alternatively, the torch may also be a torch for automated welding, especially robotic welding.

[0016] The device further includes an extraction system. The extraction system serves to provide an extraction airflow via the connection means. For this purpose, the connection means include, in particular, a connection for coupling an extraction line provided in the torch hose assembly to the extraction system.

[0017] If the device includes a power source for providing a welding or soldering current, the extraction device can, for example, be housed in the power source.

[0018] Alternatively, the extraction system can also be provided as a separate unit. This is particularly advantageous in MIG / MAG welding, as the wire feeder and welding torch typically used in MIG / MAG welding can be located very far from the welding power source during operation, for example, 30 to 60 meters. A separate extraction system can then be positioned near the wire feeder to keep the extraction line in the torch's hose assembly as short as possible and the electrical power required for the desired extraction airflow as low as possible.

[0019] The device further includes a control unit. The control unit can, for example, be a control unit of the extraction system or, if the device includes a welding or soldering power source, a control unit of the welding or soldering power source. If the extraction system has its own control unit, this can, for example, be connected to a control unit of the power source and / or to a control unit of a wire feeder via a data connection.

[0020] The control unit is designed to receive distance information about the distance between a torch connected to the connection device and the welding or soldering point, and to control the extraction system based on this distance information. In this way, the extraction system can be operated automatically depending on the distance between the torch and the welding or soldering point.

[0021] It was found that this method allows for automated and improved control of the extraction system. In particular, it enables the operation of the extraction system, preferably the extraction rate, to be automatically regulated based on the burner distance. This ensures sufficient extraction rate for the reliable removal of flue gases while simultaneously preventing the protective gas mantle, essential for proper operation, from being lost. For example, this method automatically takes into account that increasing the burner distance typically requires a higher extraction rate to reliably remove the flue gases, while decreasing the burner distance typically requires a lower extraction rate to maintain the protective gas mantle.

[0022] In this context, the torch distance of a torch to the welding or soldering point is understood to be, in particular, the distance from the front end of the torch to the welding or soldering point on the workpiece.

[0023] Distance information regarding the torch distance can be, for example, a value of the torch distance in a unit of length, such as millimeters. Distance information can also be a differential value, such as the deviation of the torch distance from a specified distance or a reference value. Furthermore, distance information can be a value of a distance that is directly related to the torch distance, for example, the distance from the welding or soldering point to an extraction port on the torch, which is particularly suitable for controlling the extraction unit. Distance information can also be the value of a quantity that is so closely related to the torch distance or its changes that the value of this quantity provides information about the torch distance or its changes.For example, in MIG / MAG welding with arc length control, the welding current can be used as an indicator of a change in torch distance and thus as distance information by keeping the voltage drop across the welding wire projection and the welding arc constant. A differential value of such a quantity, for example, a deviation of a quantity related to torch distance from a reference value, can also be used as distance information.

[0024] In principle, it is conceivable that the control unit receives the distance information, for example from the connected burner, for example when using a burner with a distance measuring device, such as an optical or acoustic distance measuring device, or from an external distance measuring device.

[0025] Preferably, the control unit is configured to obtain the distance information about the torch distance by receiving operating parameters from a welding power source, any wire feeder used, and / or the connected torch, and calculating the distance information based on these operating parameters. This eliminates the need for separate distance measuring devices.

[0026] The aforementioned problem is further solved according to the invention by a system for welding or brazing under a protective gas atmosphere comprising the device described above or an embodiment thereof and a torch with integrated extraction that can be connected to the connection means of the device, see claim 9.

[0027] The torch is preferably a hand-held torch. In particular, the torch may comprise a torch section with a handle and a torch head, as well as a hose assembly for connecting the torch section to the device's connection points. The hose assembly may, for example, have one or more connections for coupling to one or more connections of the device's connection points. Alternatively, the torch may also be a torch for automated welding, in particular robotic welding.

[0028] The following describes various embodiments of the device, the system, and the method, with each embodiment applying independently to the device, the system, and the method. Furthermore, the embodiments can be combined with one another as desired.

[0029] In one embodiment, the control unit is configured to control the extraction rate depending on the determined distance information, in particular to set an extraction rate value that depends on the determined distance information. In a corresponding embodiment of the method, the extraction rate of the extraction device is controlled depending on the determined distance information, in particular to set an extraction rate value that depends on the determined distance information.

[0030] In this way, the extraction power can be automatically adjusted to the burner distance (e.g. LB ) between workpiece and burner, so that extraction of the flue gases can be ensured while simultaneously operating a stable protective gas jacket.

[0031] By controlling the extraction rate depending on the distance information, it is particularly possible to adjust the extraction rate depending on the distance (e.g. LO) adjust the distance between the extraction opening on the torch and the welding or soldering point. The extraction opening can, for example, be located at the front end of the torch. In this case, the distance corresponds, for example, to... LO the burner distance LB . Typically, however, the extraction opening is set at a predetermined distance (e.g. C ) set back from the front end of the burner. In this case, the distance L corresponds to O for example the burner spacing LB plus a constant distance (e.g. C The control unit may, for example, contain a function, such as one stored in a data memory of the control unit, that executes a received distance information, such as a burner distance value. LB, a value for the distance LO and / or a value of a quantity other than distance information, such as welding current ISor its modification, assigns an associated extraction power value, and the control device can be configured to control the extraction device with the assigned extraction power value.

[0032] The extraction power can be controlled, for example, via the volume flow, for example by controlling a valve, or via the speed of a rotor of the extraction device.

[0033] The extraction performance value can be, for example, a target value or a lower and / or upper limit, such as for the volume flow rate or the rotor speed of the extraction device. For instance, the extraction device may have a control system for the extraction performance, the target value or operating range of which is adjusted depending on the measured value.

[0034] According to the invention, the control device is configured to determine the distance information depending on current welding or soldering parameters.

[0035] In particular, the control unit can be configured to determine the distance information based on one or more of the following welding or soldering parameters: current supplied by the power source (welding or soldering current), voltage supplied by the power source (welding or soldering voltage), wire feed speed of a wire feeder, and arc length. In this way, the distance information can be determined from values ​​that are generally already available or can be measured using simple electronic circuits, thus eliminating the need for separate distance measuring devices. The welding or soldering parameters can be measured values ​​or actual values, or they can be setpoint values ​​from a control system. It is also conceivable that a welding parameter, such as the welding current, can be used directly as distance information. I S .

[0036] In MIG / MAG welding, the distance information can be determined, in particular, based on the length of the free welding wire outside the torch (also known as stickout length) and the arc length, especially as their sum. The stickout length can be calculated as a function of the welding voltage, welding current, and wire feed rate. For the arc length, a setpoint value from an arc length control system—a common feature in MIG / MAG welding—can be used.

[0037] In TIG welding, the distance information can be determined primarily based on the arc length, which can be calculated as a function of the welding voltage. Furthermore, the fixed protrusion length of the non-consumable welding electrode during the welding process can be taken into account to calculate the distance information.

[0038] In one embodiment, particularly in a device for MIG / MAG welding or brazing, the control unit is configured to regulate the arc length, specifically by controlling a welding voltage, for example, the voltage drop across the protruding welding wire and the arc, to a setpoint. In this way, the arc length is kept constant, while the length of the protruding welding wire from the torch changes when the torch distance is altered. In this embodiment, information about the welding current, such as its magnitude or its change relative to a predetermined reference value, can be used as distance information.It has been shown that a decreasing welding current indicates an increase in the overhang length and thus the torch distance, and vice versa, so that the welding current or its change allows a conclusion to be drawn about the torch distance or its change.

[0039] In one embodiment, the control unit is configured to obtain the current welding or soldering parameters from the power source and / or any wire feeder used. This eliminates the need for separate acquisition of the welding or soldering parameters, as these are already acquired by the power source and / or any wire feeder used, or are predefined as setpoints in a control system.

[0040] In one embodiment, the control unit is configured to receive a torch trigger signal from the activation of a torch connected to the power supply during operation. Upon receiving this signal, the unit activates the extraction system or increases its extraction capacity for operation at full power. This allows the user to manually start the extraction system or switch from idle operation at low speed to full power operation before commencing welding or brazing, particularly by reactivating the torch trigger. In this way, the extraction system begins operating at full power even before the actual welding or brazing process starts, allowing the necessary negative pressure to build up and ensuring that the required extraction flow is immediately available when welding or brazing begins.For this purpose, the control device can preferably be configured to switch on the extraction device or increase its extraction capacity for power operation upon receipt of a first torch button signal, and to initiate a welding and / or soldering process upon receipt of a subsequent second torch button signal.

[0041] In one embodiment, the connection means include an extraction port for connecting an extraction line from a torch connected to the connection means. If the device includes a power source for providing welding or soldering current, the extraction device can, for example, be integrated into the power source and the extraction port arranged on the power source. If the extraction device is designed as a separate unit, the extraction port can, in particular, be arranged directly on the extraction device.

[0042] For example, a torch whose hose assembly has several connections can be connected to such a device with a suction port, in particular a connection for connecting the hose assembly to a torch connection of a wire feeder and another connection for connecting the hose assembly to the suction port.

[0043] In one embodiment, the device includes a power source for providing a welding or soldering current. The extraction system can, for example, be integrated into the power source.

[0044] In one embodiment, the device comprises a wire feeder, and the connection means include a torch connection on the wire feeder. The torch connection serves, in particular, to supply the welding or brazing wire fed by the wire feeder. Furthermore, the torch connection can be configured to supply a shielding gas flow. Additionally, the torch connection can be configured to supply the welding or brazing current provided by the welding power source.

[0045] The wire feeder preferably includes a control unit. For example, the control unit of the device can be formed by or comprise the control unit of the wire feeder. In particular, the control unit of the wire feeder can be connected to the extraction device, especially a control unit of the extraction device, via a data connection.

[0046] In one embodiment, the control unit is configured to initially set the extraction rate to a starting extraction rate value at the beginning of operation or full-scale operation of the extraction system and then reduce it. In this way, the extraction system is initially operated at a high starting extraction rate to build up the negative pressure required for providing the extraction airflow more quickly. This shortens the time between starting the extraction system or the beginning of full-scale operation and reaching the desired extraction rate or airflow. The starting extraction rate can be set independently of any distance information. For example, the control unit can be configured to operate the extraction system at the starting extraction rate value for a specific period of time before reducing the extraction rate.

[0047] The reduction of the extraction rate is preferably achieved to a target extraction rate or target extraction airflow, which is set depending on the distance information. In particular, the control unit can be configured for this purpose.

[0048] Further advantages and features of the device, the system and the method will become apparent from the following description of exemplary embodiments, with reference to the accompanying drawing.

[0049] The drawing shows Fig. 1a-cein exemplary embodiment of the device and the system, Fig. 2 the exemplary embodiment from Fig. 1a-c In an abstract representation, Fig. 3 shows examples for determining the extraction airflow depending on the burner distance or the distance. L 0 , Fig. 4a-leg example of the control of the device from Fig. 1a-c or 5Fig. 5 shows a further embodiment of the device and the system, and Fig. 6 shows the embodiment from Fig. 5 in an abstract representation.

[0050] The Fig. 1a-c show a schematic representation of an exemplary embodiment of the device and the system. Fig. 1a shows a schematic view of device 100 and system 200. Fig. 1b shows a schematic detail view from Fig. 1a . Fig. 1c shows the welding torch Fig. 1b during an ongoing welding process on a workpiece.

[0051] In the present embodiment, the device 100 is designed as a welding device and is described accordingly below. Alternatively, it is also conceivable to design the device 100 in a corresponding manner as a soldering device.

[0052] Furthermore, in the present embodiment, the device 100 is designed for metal inert gas (MIG) welding, for example, for metal inert gas (MIG) or metal active gas (MAG) welding. Alternatively, the device 100 could also be designed for use in TIG or plasma welding.

[0053] The device 100 comprises a welding power source 110 for providing a welding current, a power unit 112, a control unit 114, and an extraction device 116. The control unit 114 is configured to control the welding power source 110 and, in particular, controls the power unit 112 and the extraction device 116. The power unit 112 is configured to provide a welding current for welding via an electrical output 118 of the welding power source 110. Furthermore, the welding power source 110 has an extraction port 120 for an extraction line, and the extraction device 116 is configured to provide a negative pressure or extraction airflow via the extraction port 120.

[0054] The device 100 further comprises a wire feeder 150 for transporting a welding wire 152. The wire feeder 150 has a welding wire supply 154 in the form of a welding wire drum, a welding wire conveying device 156, which preferably includes driven rollers for controlled conveying of the welding wire 152, and a control unit 160, which is designed to control the wire feeder 150.

[0055] The wire feeder 150 further comprises an electrical input 162 for supplying the welding current provided by the welding power source 110, which is connected to the electrical output 118 of the welding power source via an electrical line 119 for operation. The wire feeder 150 also comprises a shielding gas inlet 164 for supplying a shielding gas, which is connected to a shielding gas source 166, such as a gas cylinder, via a gas line 165 for operation.

[0056] The wire feeder 150 further features a torch connection 168 for connecting a welding torch 210. The welding wire 152 fed by the welding wire feeder 156, the welding current supplied by the welding power source 110, and the shielding gas supplied by the shielding gas source 166 are provided to the welding torch 210 via the torch connection 168.

[0057] The control unit 160 is specifically designed to control the welding wire feeder 156. Furthermore, the control unit 160 can be configured to control the shielding gas flow supplied at the torch connection 168. For this purpose, the wire feeder 150 can, for example, have a controllable valve 169 between the shielding gas inlet 164 and the torch connection 168, with which the shielding gas flow can be adjusted.

[0058] The control unit 114 of the welding power source 110 and the control unit 160 of the wire feeder 150 are preferably connected to each other via a communication link, for example via line 119 or via a separate data line, so that one of the two control units 114, 160 can transmit control commands to the other of the two control units 114, 160. In this way, for example, the control unit 114 can be configured to control both the welding power source 110 and the wire feeder 150. The control unit 114 and the control unit 160 together form a control device 190 of the apparatus 100.

[0059] A user interface 122, 172 is preferably provided on the welding power source 110 and / or on the wire feeder 150, via which the user can read operating information and / or enter control commands.

[0060] The system 200 comprises the device 100 and a welding torch 210 connected to the system 200. The welding torch 210 has a torch part 212 and a hose assembly 214, with which the torch part 212 is connected to the device 100. Fig. 1b shows a schematic detail view of burner part 212.

[0061] The hose assembly 214 is connected to the torch connection 168 of the wire feeder 150, so that during operation, the welding wire 152 fed by the welding wire feeder 156 is guided via the torch connection 168 through a hollow line running through the hose assembly 214 to the torch part 212. Furthermore, the welding current supplied by the welding power source 110 and looped through the wire feeder 150 is guided via the torch connection 168 through an electrical line running through the hose assembly 214 to the torch part 212, where the welding current is directed to the welding wire 152 via a contact point, for example, a contact tube through which the welding wire 152 is guided. Additionally, during operation, the shielding gas flow supplied at the torch connection 168 is guided through a shielding gas line running through the hose assembly 214 to the torch part 212 to generate a shielding gas atmosphere for the welding process.

[0062] The hose package 214 is still connected via a branch to the extraction port 120 of the welding power source 110, so that during operation an extraction airflow caused by the extraction device 116 can be provided at the torch part 212 via an extraction line running through the hose package 214.

[0063] The torch connection 168 of the wire feeder 150 and the extraction connection 120 of the welding power source together form connection means 180 of the device 100 for connecting the torch 210.

[0064] The torch part 212 comprises a handle 216 and a torch head 218 with an opening 220 at the front end of the torch 210, from which the welding wire 152, supplied with welding current, is led out during operation and the shielding gas flow 170 exits.

[0065] The torch head 218 also has extraction openings 222, which in the present example are set back by a distance C from the opening 220 and which are connected to the extraction device 116 via the hose package 214 and the extraction port 120, so that during operation an extraction airflow 117 is provided at the torch head 218, with which fume gases generated during welding at the welding point 226 on the workpiece 228 are extracted through the torch head 218.

[0066] A torch trigger 230 is provided on the handle 216 of the torch section 212. In simple welding torches, the terminals of the torch trigger are connected to corresponding contacts on the torch connection 168 via two electrical torch trigger lines running through the hose assembly 214. This allows the control unit 190 to detect the activation of the torch trigger 230 and, for example, to start a welding process when the torch trigger 230 is activated. In more advanced welding torches with their own torch control unit 232, the torch trigger can be connected to the torch control unit 232 additionally or alternatively. The torch control unit 232 can be connected to the control unit 190 via the torch trigger lines and / or via separate data lines running through the hose assembly and contacts on the torch connection 168 or extraction port 120.The torch control unit 232 allows welding parameters such as the welding current to be set directly at the welding torch 210. The torch control unit 232 can also be configured to transmit information about the torch type of the torch 210 to the control unit 190.

[0067] Fig. 2 shows an abstract representation of device 100. In detail, it shows Fig. 2 the control unit 114 of the welding power source 110, the extraction device 116 connected to the control unit 114, and the extraction port 120 to which the welding torch 210 is connected. Furthermore, it shows Fig. 2The control unit 160 of the wire feeder 150 and the torch connection 168, to which the welding torch 210 is also connected. The extraction connection 120 and the torch connection 168 together form the connection means 180 of the device 100 for the welding torch 210. The control units 114 and 160 together form the control device 190 of the device 100.

[0068] The control unit 190 is configured to receive distance information about the distance between the torch 210 connected to the connection means and the welding point 226, and to control the extraction unit 116 depending on the determined distance information. This is explained in detail below.

[0069] Fig. 1cFigure 210 shows the welding torch 210 during an ongoing welding process on a workpiece 228. During the welding process, the welding wire 152 is fed through the wire feeder 150 and exits the opening 220 of the torch head 218. The length of the free welding wire 152 outside the torch 210, i.e., the stickout length, is shown in Figure 210. Fig. 1b with LS designated.

[0070] Between the tip of the welding wire 152 and the weld point 226 on the workpiece 228, the welding arc 229 burns during the welding process with an arc length LA .

[0071] The burner distance LB In this example, this results as the sum of the arc lengths LA and the overhang length LS: L B = L A + L S .

[0072] Furthermore, the distance LO between the extraction openings 222 and the welding point 226 as a sum of LB and C : L 0 = L B + C .

[0073] The control unit 190 is designed to receive distance information about the burner distance. LB to obtain the current of the torch 210 connected to the connection means 180 to the welding point 226. For this purpose, the control device 190, in particular the control unit 114, is configured to obtain current welding parameters such as the welding current. IS , the welding voltage provided by the welding power source 110 US and / or the wire feed speed v D .For example, control unit 114 can receive the current welding current and welding voltage from a current or voltage measuring circuit of the welding power source 110. Alternatively, in the case of voltage or current regulation, control unit 114 can also use the current setpoint for the welding voltage or welding current. The current wire feed speed can, for example, be transmitted from control unit 160 to control unit 114.

[0074] The control device 190, in particular the control unit 114, is further configured to determine the distance information from the received current welding parameters. This can be done, for example, as follows: The control device 190 can, for example, be configured to perform welding voltage control during the welding process, in particular such that the voltage drop UBis kept constant via the welding wire protruding from the welding torch 210 and the arc. UB This can be determined, for example, by the following formula: U B = U S − R S Rest ⋅ I S , where US the voltage provided by the welding power source, IS the welding current and R S Rest The electrical resistance of all components in the welding circuit, with the exception of the (typically unknown) electrical resistances of the protruding welding wire and the arc. The regulation of UB Maintaining a constant value is achieved in particular by adjusting the welding current. IS Such a regulation causes the arc length to LA The arc length is kept constant; it is therefore an arc length control.

[0075] Does the distance decrease with such an arc length control? LB, This reduces the overhang length accordingly. LS , since LAThe regulation essentially keeps the overhang length constant. However, this is only the case if the overhang length decreases. LS The duration of the (heat) energy input into a welding wire section is reduced during its advancement along the overhang length. LS . Accordingly, the welding current must IS and thus increase the heat output introduced into this welding wire section, so that it reaches the end of the overhang length LS The heat energy required to melt the welding wire section is supplied. Conversely, the welding current must be supplied. IS can be reduced if the distance is changed during arc length control. LB and thus the overhang length LS increased so that the heat energy required to melt the welding wire section is not lost before the protrusion length is reached LS is inserted into the welding wire section.

[0076] This allows the welding current to be controlled. ISor its change from an initial value as an indicator of a change in distance. LB can be used to control the extraction system depending on distance information about the burner distance. LB to control. In particular, the control device can be configured to determine the value of IS or the difference of IS and a reference value I S Ref The distance information is obtained to determine the distance between the burners and to use it for controlling the extraction system. In this case, the distance information represents a relative change in the distance. LB to.

[0077] It is also conceivable that the control unit uses distance information about the burner distance to provide a value for the absolute size of the burner distance. LB determined. For this purpose, for example, reference values ​​of welding parameters with assigned values ​​for the torch distance can be stored in a data memory of the control unit. LB be stored. For example, typical wire feed speeds (e.g. v D = 5 m / min, 10 m / min and 15 m / min) and certain setpoints for UB the respective context of IS and LB The parameters are measured in advance and stored on the control unit's data memory. During operation, the current welding parameters can then be used. VD, UB and IS assigned burner spacing LB The distance is determined based on the data stored in the data storage and used as distance information about the burner distance.

[0078] The distance C This information can also be stored, for example, in a data memory of the control unit 190. It is conceivable, for instance, that the respective distance for different burner types could be stored in such a data memory. Cis stored and the control unit 190 is configured to receive torch type information, for example from the welding torch 210 itself or via the user interface 122, and the distance C depending on the burner type information from the data storage.

[0079] By means of the specific burner distance LB and the distance obtained C Can the control unit 190 then, for example, determine the distance? LO calculate using formula (2) and LB or LO Use as distance information for the burner distance.

[0080] The control unit 190 is further configured to control the extraction unit 116 depending on the determined distance information. For this purpose, the control unit 190 can be configured to determine a corresponding extraction performance value of the extraction unit 116, for example a corresponding volume flow rate V, using a predefined calculation rule based on the determined distance information. The volume flow rate V can be set or regulated, for example, by controlling the speed of a fan of the extraction unit 116.

[0081] For example, in the case of arc length control as described above IS or ΔI S = I S − I S Ref If distance information about the burner distance is used, the volume flow rate V can be calculated, for example, using a predefined function V̇( IS ) or V̇ ( ΔI S ) can be set. An example of such a function is V ˙ ΔI S = V ˙ 0 − k ⋅ ΔI S , where V̇ 0 a given reference volume flow rate, and k a given constant (with unit: m³ / (A h)). Using this function, an increase of IS or ΔI S as an indicator of a smaller burner distance LB a lower volume flow rate and vice versa.

[0082] As described earlier, a value for LB If distance information about the burner distance is used, the volume flow rate V can be calculated, for example, using a predefined function. V̇ ( LB ) be set. A suitable calculation method for determining the volume flow rate V as a function of the burner distance. LB or the distance LO For example, the following formula represents this: V ˙ L B = 4 ⋅ π ⋅ ν ⋅ L 0 2 = 4 ⋅ π ⋅ ν ⋅ L B + C 2 , where v is a predetermined air velocity of the extraction airflow at the point of welding fume generation, i.e., at the welding point 226. The value of v can, for example, be stored in a data memory of the control unit 190.

[0083] Formula (5) results from the assumption of an approximately spherical suction field 234 around the extraction openings 222, i.e. a suction field whose air velocities decrease approximately uniformly with the distance to the extraction openings 222 in different directions, so that the air velocities on a spherical surface around the extraction openings 222 are approximately equal in magnitude.

[0084] The point of origin of the welding fumes, i.e., the welding point 226, is thus located on the surface of a sphere around the extraction openings 222 with a radius corresponding to the distance between the torch and the welding torch. LB dependent distance LO This corresponds to a sphere that has a surface area of... O = 4πL 0 2< so that, with a given air velocity v at the welding point 226, the required (total) extraction airflow V through the extraction openings 222 is determined by formula (2) depending on the distance L 0 or from the burner distance LB can be calculated.

[0085] Fig. 3 shows a diagram illustrating the relationship between volume flow rate V (in m³ / h) and the distance L 0 (in mm) according to the above formula (5) for two given air velocities v = 0.25 m / s and v = 0.35 m / s. For a given air velocity v = 0.25 m / s, the following results at a distance L 0 = For example, 60 mm corresponds to a volume flow of approximately 40 m³ / h.

[0086] By adjusting the extraction airflow V depending on the distance information about the burner distance. LB, for example, depending on LB, from L 0 or from IS ,This also applies to varying burner distances. LB to achieve consistently reliable extraction of welding fumes, while at the same time preventing the shielding gas jacket of the shielding gas flow 170 flowing out of the opening 220 of the welding torch 210 from being destabilized by the fume extraction.

[0087] The Fig. 4a-b illustrates an example of a possible control of the extraction device 116 by the control unit 190. The diagram in Fig. 4a The abscissa represents time t and the ordinate the volume flow rate V. The dashed line shows the volume flow rate (setpoint) set by the control unit 190 at the extraction unit 116. The solid line shows the actual volume flow rate (actual value). The diagram in Fig. 4b The abscissa shows the time t and the ordinate shows the distance information about the determined burner distance. LB . In Fig. 4bis an example LB even shown as distance information; however, another suitable distance information is also used (e.g. L 0 , IS , ΔI S , ΔL B ) is in question.

[0088] At time t 0, the welding torch 210, connected to the connection means 180, is not in operation and is hanging, for example, by its hose assembly over a bracket provided on the welding power source 110 or on the wire feeder 150. The extraction device 116 is switched off at this time or in idle mode (V = 0). A torch distance LB The temperature cannot be determined at this time because no welding arc is burning.

[0089] At time t1, the start time of the welding process, the control unit 190 receives a torch trigger signal from the welding torch 210 via the activation of the torch trigger 230. The control unit 190 is configured to switch on the extraction unit 116 upon receiving the torch trigger signal, if it is currently switched off. Furthermore, in this example, the control unit 190 is configured to initially set the extraction rate of the extraction unit 116 to a starting extraction rate value for a duration T12. Fig. 4 specified as the starting volume flow rate V̇ 0, before the extraction power is reduced at time t 2 and the control unit adjusts the target volume flow rate V from this point onwards depending on the received distance information, for example LB or LO or IS or Δ IS , The burner distance LB is determined and the extraction device 116 is adjusted accordingly.

[0090] Determining the distance information via the burner spacing LB The control device 190 begins at a time t A after the arc has been ignited.

[0091] In the example in Fig. 4a-bThe welder initially maintains a constant distance between the torch 210 and the workpiece 228, so that the target volume flow rate V also remains constant. From time t 3, the welder increases the distance between the torch 210 and the workpiece 228, causing the control unit 190 to determine a larger target volume flow rate V, for example according to formula (4) or (5), and to control the extraction unit 116 accordingly. For example, the rotational speed of a rotor of the extraction unit 116 can be controlled to adjust the volume flow rate of the extraction unit 116. From time t 4, the welder reduces the distance between the torch 210 and the workpiece 228 again. The volume flow rate of the extraction unit 116 is automatically adjusted by the described control system.

[0092] The control described above enables dynamic control of the extraction device 116 depending on the distance information about the torch distance, thereby achieving consistent welding quality with reliable extraction of welding fumes.

[0093] Fig. 5 shows a further embodiment of the device and system in one of the Fig. 1a corresponding schematic representation. Furthermore, it shows Fig. 6 one of the Fig. 2 corresponding illustration for the further exemplary embodiment.

[0094] Device 300 and device 100 have a similar structure and function, so the following will mainly describe the differences between the two devices and otherwise refer to the description above.

[0095] In the present embodiment, the device 300 is designed as a device for use in welding and is described accordingly below. Alternatively, it is also conceivable to design the device 300 in a corresponding manner as a device for use in soldering.

[0096] Furthermore, in the present embodiment, the device 300 is designed for use in metal inert gas (MIG) welding, for example, in metal inert gas (MIG) or metal active gas (MAG) welding. Alternatively, the device 300 could also be designed for use in TIG or plasma welding.

[0097] Device 300 differs from device 100 in that the extraction device 316 is designed as a separate extraction unit 317 from the welding power source 310. Device 300 comprises the extraction unit 317 and a wire feeder 350 connected to it during operation. The welding power source 310 is designed separately and is not part of device 300.

[0098] Like the welding power source 110, the welding power source 310 has a power unit 312, a control unit 314, and a user interface 322. Furthermore, the welding power source 310 has a connection 318 for a hose assembly 319 to the wire feeder 350. The welding current from the power unit 312, as well as the shielding gas flow routed through the welding power source 310 and controlled, for example, by a controllable valve 324 of the welding power source 310, are supplied via connection 318.

[0099] The extraction unit 317 comprises a control unit 330, a fan 332 controlled by the control unit 330 for generating the extraction volume flow, an extraction port 344, and a user interface 336. The welding torch 210 is connected via the hose assembly 214 to the torch connection 368 of the wire feeder 350 and to the extraction port 344 of the extraction unit 317. The torch connection 368 and the extraction port 344 together form the connection means 380 of the device 300. The control unit 390 of the device 300 includes the control unit 330 and can optionally also include the control unit 360 of the wire feeder 350.

[0100] The control unit 390, like the control unit 190, is configured to obtain distance information about the torch distance LB of a torch 210 connected to the connection means 380 to the welding point 226. The determination of the distance information (e.g. LB, Lo or IS) about the burner distance LB This can be done in a similar manner to what was previously described for device 100.

[0101] The control device 390, in particular the control unit 330, is further configured to control the extraction device 316, in particular the fan 332, depending on the determined distance information. The control of the extraction device 316, in particular the fan 332, depending on the distance information can be carried out in a similar manner to that previously described for the device 100.

[0102] The device 300 and the burner 210 connected to it together form the system 400.

[0103] Designing the extraction device 316 as a separate extraction unit 317 has the advantage that it can be arranged close to the wire feeder 350, even if the wire feeder 350 is located far from the welding power source 310 via a long hose package 319.

[0104] The previously described devices 100 and 300, systems 200 and 400, and the described methods simplify and improve the control of the extraction system. In particular, the extraction capacity can be automatically adjusted based on the received distance information regarding the burner spacing LB, thus enabling better adaptation to this distance. This ensures reliable extraction of exhaust gases, especially flue gases, from the welding or brazing joint, while simultaneously maintaining a stable shielding gas atmosphere.

[0105] Controlling the extraction system based on distance information about the torch distance can also be used in TIG welding. In this case, the torch distance can be... LB for example, as the sum of the fixed overhang length LS the non-consumable (tungsten) electrode and the arc length LA to be calculated, whereby the arc length LA For example, in TIG welding with the formula L A = K ⋅ U A can be calculated, whereby U A = U S − R S Rest ⋅ I S the voltage drop across the TIG arc, which - analogous to formula (3) - results from the welding voltage US minus the cost of the welding current IS about the known resistances R S Rest the voltage drop in the TIG welding circuit can be calculated, and K a given proportionality constant. Reference symbol list:

[0106] 100, 300: device 180, 380: Connection device 110, 310: welding power source 190, 390: Control unit 112, 312: Power section 200, 400: system 114, 314: Control unit of the welding power source 210: welding torch 212: burner part 116, 316: extraction system 214, 319: Hose package 117: Extraction airflow 216: handle 118: electrical output of the welding power source 218: burner head 220: opening 119: electrical line 222: Extraction openings 120, 344: extraction port 226: weld point 122: User interface of the welding power source 228: workpiece 229: Welding arc 150, 350: wire feeder 230: Burner button 152: Welding wire 232: burner control unit 154: Welding wire supply 234: Suction field 156: Welding wire feeder 317: extraction unit 160, 360: Control unit of the wire feeder 318: Connection of the welding power source for a hose package 162: electrical input 164: Inert gas inlet 322: User interface of the welding power source 165: Gas pipeline 166: shielding gas source 330: Control unit of the extraction device 168, 368: Burner connection 169, 324: valve 332: fan 170: protective gas flow 336: User interface of the extraction unit 172, 372: User interface of the wire feeder

Claims

1. Apparatus (100, 300) for welding or soldering under a shielding gas atmosphere, - having a power source (110, 310) for providing a welding or soldering current, - having connection means (180, 380) for connecting a torch (210) with integrated extraction, - having an extraction device (116, 316) for providing an extraction air flow (117) via the connection means (180, 380), and - having a control device (190, 390) for controlling the extraction device (116, 316), characterized - in that the control device (190, 390) is configured to determine distance information concerning the torch distance (LB) of a torch (210), connected to the connection means (180, 380), from the welding or soldering location (226) as a function of current welding or soldering parameters, and to control the extraction device (116, 316) as a function of the determined distance information.

2. Apparatus (100, 300) according to claim 1, characterized in that the control device (190, 390) is configured to control the extraction power as a function of the determined distance information, in particular to set an extraction power value depending on the determined distance information.

3. Apparatus (100, 300) according to claim 1 or 2, characterized in that the control device (190, 390) is configured to determine the distance information as a function of one or more of the following welding or soldering parameters: current (IS) provided by the power source (110, 310), voltage (US) provided by the power source, wire feed speed (vD) of a wire feeder (150, 350) used, arc length.

4. Apparatus (100, 300) according to any one of claims 1 to 3, characterized in that the control device (190, 390) is configured to receive the current welding or soldering parameters from the power source (110, 310) and / or from a possibly used wire feeder.

5. Apparatus (100, 300) according to any one of claims 1 to 4, characterized in that the control device (190, 390) is configured to receive a torch trigger signal concerning the actuation of a torch trigger (230) of a torch (210) connected to the connection means (180, 380), and, upon receiving the torch trigger signal, to switch on the extraction device (116, 316) or to increase its extraction power for a power operation.

6. Apparatus (100, 300) according to any one of claims 1 to 5, characterized in that the connection means (180, 380) comprise an extraction connection (120, 344) for connecting an extraction line of a torch (210) connected to the connection means (180, 380).

7. Apparatus (100, 300) according to any one of claims 1 to 6, characterized in that the apparatus (100, 300) comprises a wire feeder (150, 350) connectable to the power source (110, 310), and the connection means (180, 380) comprise a connection on the wire feeder (150, 350).

8. Apparatus (100, 300) according to any one of claims 1 to 7, characterized in that the control device (190, 390) is configured to initially set the extraction power to a starting extraction power value at the beginning of the operation or the power operation of the extraction device (116, 316), and subsequently to reduce it.

9. System (200, 400) for welding or soldering under a shielding gas atmosphere, - comprising an apparatus (100, 300) according to any one of claims 1 to 8, and - a torch with integrated extraction connectable to the connection means (180, 380) of the apparatus.

10. Method for controlling an extraction device (116, 316) of an apparatus (100, 300) for welding or soldering under a shielding gas atmosphere, in particular an apparatus (100, 300) according to any one of claims 1 to 8, - in which distance information concerning the torch distance (LB) of a torch (210), connected to the connection means (180, 380), from the welding or soldering location (226) is determined, and the extraction device (116, 316) is controlled as a function of the determined distance information, wherein the distance information is determined as a function of current welding or soldering parameters.

11. Method according to claim 10, characterized in that the extraction power of the extraction device (116, 316) is controlled as a function of the torch information.