weld cleaning device

Abstract

Weld cleaning device (10) for electrochemical cleaning, polishing, marking and passivating a weld (11) of a workpiece, in particular a weld cleaner, comprising a power supply device (12), in particular a power supply unit, a weld contact device (14), in particular a contact brush or carbon fiber brush, and an electrolyte medium (18), wherein the power supply device (12) is configured to provide the weld contact device (14) with an electrical cleaning energy (16), comprising a cleaning current (I), a cleaning voltage (U), a cleaning power (P) and a cleaning current density (J), at least by scaling, preferably by conversion and / or commutation, and the weld contact device (14) is configured to transmit the cleaning energy (16), preferably by contact contact,to transfer to the weld seam (11) and to clean the weld seam (11) by interaction with the electrolyte medium (18) and the cleaning energy (16), characterized in that a current control device (20) is included which is configured to control the cleaning energy (16), preferably automatically / self-regulating, on the basis of at least one property of the weld seam contact device (14), the electrolyte medium (18), and / or the workpiece material, during intended operation of the power supply device (12) by controlling at least one component, in particular an inverter (30, 40), of the power supply device (12).

Description

[0001] The invention relates to a weld seam cleaning device for electrochemically cleaning, polishing, marking and passivating a weld seam of a workpiece, in particular a weld seam cleaner. STATE OF THE ART

[0002] Nowadays, in a large number of technical joining applications in the form of welding processes, careful cleaning of weld seams on workpieces plays a fundamental role in order to meet the mechanical, chemical, hygienic and, if necessary, aesthetic requirements, such as anti-corrosive properties and / or sterility, of the weld seam or the workpiece, depending on the application.

[0003] The state of the art offers a number of options in this regard, including mechanical surface treatments as well as purely chemical or electrochemical surface treatments. Electrochemical cleaning of weld seams has proven particularly practical.

[0004] Electrochemical cleaning typically involves the use of a specialized weld seam cleaning device, which, in addition to cleaning, also typically enables polishing, marking, and passivation of the weld seams.

[0005] Such a weld seam cleaning device basically comprises a power supply, a weld seam contact device, and an electrolyte. The power supply converts electrical energy, typically a mains current, through a series of electrical conversion steps, usually scaling and conversion, into electrical cleaning energy with a modified, usually increased, current intensity and / or voltage compared to the original energy. This energy is then supplied to the weld seam contact device and the workpiece with the welded joint to be machined. The weld seam contact device transfers the cleaning energy to the weld seam by contact. The weld seam contact device—usually a conductive contact brush—is wettable with the electrolyte. For this purpose, a felt impregnated with the electrolyte is often wrapped around the weld seam contact device.When the weld is touched, an electrical cleaning circuit of cleaning energy is closed between the weld contact device and the workpiece, causing the electrolyte to undergo an electrochemical reaction with the metallic material of the weld. This reaction, usually a reduction of the surface oxide layer, cleans the weld by scanning or moving along the weld with the weld contact device and the resulting contact contact, combined with the resulting electrochemical reaction. This cleaning process, along with the resulting electrochemical reaction, usually also results in passivation.

[0006] The problem with this type of surface treatment is to provide enough electrical energy for the effect and at the same time to limit the energy so that the electrolyte is not overheated by excessive electrical power and thus burned and / or the weld is not damaged or further contaminated.

[0007] A generic weld seam cleaning device is known, for example, from DE 20 2021 103 661 U1. This discloses an arc welding device with a cleaning function, wherein a power supply device provides both an electric welding current for the welding process and an electric cleaning energy for the subsequent cleaning of the weld seam. In order to avoid damage to the weld seam due to excessive electrical power in view of the previously discussed problem, the known solution provides that the maximum power remains within a predetermined, potentially safe range by specifying or throttling the current and voltage. For this purpose, the current and voltage are set to a specific, relatively low value within a specified range at the beginning of the cleaning process and are kept constant throughout the entire cleaning process.In other words, the maximum power is deliberately kept relatively low and constant, or throttled, to fundamentally eliminate the risk of excessive power being generated. This ensures that the power never reaches or can reach a potentially harmful level.

[0008] The disadvantage of this known solution, however, is that due to the targeted throttling of the current output to a relatively low level, the corresponding cleaning potential or cleaning performance increasingly fails to meet the high requirements and is regularly inadequate or reduces the cleaning speed. Furthermore, a consistent or even cleaning result can rarely be achieved. According to Ohm's law, the effective current output depends on the electrical resistance of the contact surface of the weld seam with the weld seam contact device, as well as that of the electrolyte. Since manual operation orWhen moving along the weld seam, a user finds it difficult to maintain a constant contact surface between the weld contact device and the workpiece due to natural vibration, inclination, and topological irregularities of the weld surface. The effective electrical resistance varies continuously throughout the cleaning process. Consequently, the current output also varies continuously, resulting in uneven cleaning performance.

[0009] Thus, the known solution not only often achieves an inadequate cleaning result due to the fundamentally low possible cleaning performance, but also an irregular cleaning result due to the natural or unavoidable fluctuation of the electrical resistance.

[0010] The object of the invention is to provide an improved weld seam cleaning device which not only reliably provides sufficient but also constant cleaning performance.

[0011] This object is achieved by a weld seam cleaning device according to the independent claims. Advantageous embodiments of the invention are the subject of the dependent claims. DISCLOSURE OF THE INVENTION

[0012] The invention relates to a weld seam cleaning device for electrochemically cleaning, polishing, marking, and passivating a weld seam of a workpiece, in particular a weld seam cleaner. The weld seam cleaning device comprises a power supply device, in particular a power supply, a weld seam contact device, in particular a contact brush or carbon fiber brush, and an electrolyte. The power supply device is designed to provide the weld seam contact device with electrical cleaning energy, which comprises a cleaning current intensity, a cleaning voltage, a cleaning current power, and a cleaning current density, at least by scaling, preferably by converting and / or commutating.The weld seam contact device is designed to transfer the cleaning energy, preferably by contact, to the weld seam and to clean the weld seam by interaction with the electrolyte and the cleaning energy.

[0013] The electrical cleaning energy is obtained by converting electrical output energy, particularly from a power grid. The conversion is carried out by the power supply device and includes, in particular, scaling, switching or converting from direct current (DC) to alternating current (AC) and vice versa, and / or commutation. The electrical cleaning energy comprises: - a cleaning current that can be physically described by the known general formulas for the current I, namely I=P / U and I=U / R, - a cleaning voltage, which can be physically described by the known general formulas for the (current) voltage U, namely U=P / I and U=R*I, - a cleaning current power which is physically determined by the known general formulas for the power P, namely P=U*I, P=R·I 2 and P=U 2 / R, is writable, - and a cleaning current density that can be physically described by the known general formulas for the current density J, namely J=I / A(area).

[0014] According to the invention, it is provided that a current control device is included which is designed to regulate the cleaning energy, preferably automatically / automatically, adaptively on the basis of at least one property of the weld seam contact device, the electrolyte medium, and / or the workpiece material during intended operation of the power supply device by means of a particularly highly dynamic control of at least one component, in particular an inverter, of the power supply device.

[0015] In other words, the invention provides an adaptive control function for the cleaning energy, through which a highly dynamic control of the cleaning energy is constantly carried out during operation of the weld seam cleaning device, i.e. during the course of the cleaning process, depending on the currently occurring properties of the components involved, so that the provided cleaning energy can be adapted to the individual current conditions in real time. Depending on preference, the aforementioned components of the cleaning energy are controlled, i.e., cleaning current intensity, cleaning voltage, cleaning current power, and / or cleaning current density. In this respect, the adaptive control function relates to the individual components of the cleaning energy from which it is composed. This makes it possible to provide the optimal cleaning energy for the current conditions at any time and to maintain it at a constant level.Furthermore, in contrast to the known solution, in order to avoid excessive current output, no fundamental throttling of current and voltage is carried out from the outset, since the current output can be adaptively regulated depending on the current conditions and can therefore always be maintained at a safe level.

[0016] The weld seam cleaning device according to the invention enables precise adjustment of the cleaning current in a highly dynamic and consistent quality even with complex weld seam geometries, different materials, electrolytes and different weld seam contact devices and thus achieves efficient, time-saving processing with consistent and high-quality cleaning results.

[0017] Advantageously, the inventive solution reliably ensures sufficient cleaning performance. Because there is no need for a fundamental throttling, high current and voltage values ​​can be set for high cleaning performance – potentially dangerous in the case of conventional solutions. The adaptive or highly dynamic control always maintains the current output at a safe and, at the same time, optimal level for the current conditions. The inventive solution thus advantageously enables not only a surprisingly high-quality, but also an effective and consistent cleaning result.

[0018] In use, it can be provided that the current control device is connected to at least one current and / or voltage sensor of the power supply device, which is preferably arranged in a DC intermediate circuit of a secondary side of the power supply device, and wherein the cleaning current power is parameterizable and the current control device is designed to keep the cleaning current power, in particular current intensity and / or voltage level, essentially constant and controllable within the framework of the adaptive control. The parameters of the cleaning current power depend in particular on the electrolyte and the weld seam contact device used. As already mentioned at the beginning, the cleaning energy is provided by converting the output energy by means of the power supply device.Naturally, fluctuations in the output values, particularly the output current and output voltage, can occur, for example due to power supply fluctuations. These fluctuations can be taken into account by the sensor(s) for adaptive control. The inclusion of the parameters for the cleaning current output also enables the aforementioned dynamic adjustment of the cleaning current output to the current conditions, thus creating a way to keep the cleaning current output and thus the cleaning energy at a constant level. This advantageously provides a reliable and precise option for adaptive control, thus ensuring the achievement of consistently consistent cleaning results.

[0019] In the application, the current control device can be configured to adjust a DC amplitude curve or an AC amplitude shape of the cleaning current intensity in a highly dynamic manner within the framework of adaptive control, in particular by providing adaptive PWM (pulse width modulation) of the cleaning current intensity and an adaptive PWM clock frequency. Advantageously, this allows the cleaning energy to be controlled comparatively simply, yet effectively and precisely.

[0020] In the application, it can be provided that the current control device comprises a parameter memory which is designed to store at least one property of the weld seam contact device, the electrolyte, and / or the workpiece material, and the current control device is designed, within the framework of the adaptive control, to dynamically control the cleaning current density of the cleaning energy depending on the parameters stored in the parameter memory, in particular the electrical resistance of a contact surface of the weld seam, the electrolyte, and / or the weld seam contact device that can be contacted by the weld seam contact device, and / or the dimensioning of the contact surface. The cleaning current density is obtained, as already mentioned, according to the formula J=I / A as the quotient of the (incident) current intensity I per contact area A, for example, with the units ampere / cm 2The parameters to be included in the adaptive or dynamic control, in particular electrical resistances and the corresponding optimal cleaning current, can be stored (in advance) in the parameter memory. This essentially enables a presetting of the cleaning current or cleaning current density to be applied for the currently used weld contact device, the currently used electrolyte, the material to be processed, etc. Within the framework of the adaptive or dynamic control, the cleaning current density is kept constant based on this presetting, for example by varying the cleaning current in relation to the constantly changing (particularly topologically determined) contact surface. This also advantageously ensures that a consistent cleaning result is achieved.

[0021] In use, the power supply device can comprise at least one isolating transformer, at least one, preferably two, rectifiers, and at least one, preferably two, inverters / power converters, preferably comprising at least one stabilization and filtering unit, in particular a mains filter and / or power factor correction filter (PFC - Power Factor Compensation) for filtering out interference frequencies. The isolating transformer always ensures sufficient safety for the user. The rectifiers and inverters enable particularly efficient and effective conversion of the output current and output voltage into the cleaning current and cleaning voltage, in particular allowing for particularly high scaling. Preferably, a push-pull circuit is provided for operating the isolating transformer in order to be able to transmit the highest possible power.The stabilization and filtering unit further filters out interfering frequencies, making the conversion process even less fluctuating, while primarily ensuring a constant level of cleaning current and voltage. The power supply unit is advantageously particularly powerful and reliable.

[0022] In the application, the power supply device can be designed as a switching power supply, wherein the switching power supply has a switching frequency of at least ≥ 100 kHz. This embodiment of the power supply device enables a particularly fast and precise response or adaptation to the rapidly changing parameters or current conditions during the cleaning process. Advantageously, this enables a particularly effective and highly dynamic adaptive control.

[0023] In the application, the current control device and the power supply device can be designed to provide output ripple in the cleaning voltage of less than 2000 mV peak-to-peak and a control tolerance of the cleaning current and cleaning voltage of less than ±1.5%. This advantageously makes the adaptive control even more precise and dynamic.

[0024] Preferably, a smoothing choke can be inserted in the output circuit, especially on the secondary side of the isolation transformer. The smoothing choke ensures that the output current is smoothed and free of high-frequency voltage spikes. This is particularly important to prevent unwanted effects on the electrolyte caused by voltage spikes that occur when switching the cleaning energy on the primary or secondary side.

[0025] In use, it can be provided that the device comprises a conveying device for automatically conveying the electrolyte from an electrolyte reservoir, preferably formed or arranged internally in the device, to the weld seam contact device, and wherein the current regulating device is configured to relate the cleaning current output to a quantity of electrolyte conveyed from the electrolyte reservoir. The electrolyte can, for example, already be present or available internally in the device. Alternatively, external or manual application of the electrolyte, for example by means of an impregnated felt, is conceivable. The conveyed quantity of the electrolyte preferably remains constant with regard to the processing progress. In this respect, monitoring sensors for regulating the conveyed quantity of electrolyte can be provided if necessary.The final flow rate (how much electrolyte should be used) can be preset and subsequently kept constant by corresponding control of the flow rate depending on appropriate monitoring of the cleaning energy output or the processing progress. A demand-adapted variation of the flow rate is also conceivable, possibly even self-adjustment of the absolute amount analogous to the adaptive control of the cleaning energy. As previously mentioned, the electrolyte – both in terms of its composition and quantity – can also be included in the parameters used for the adaptive control, as this influences the electrical resistance. By incorporating the flow rate into the adaptive control, it is advantageous to maintain a qualitatively constant cleaning performance.

[0026] In the application, the weld seam contact device and / or the electrolyte can be interchangeable, allowing a variety of weld seam contact devices and / or electrolytes to be used with the device. This advantageously provides the weld seam cleaning device with a particularly wide range of possible applications.

[0027] In the application, it can be provided that the current control device comprises an input device, in particular an at least partially digital one, for the manual and / or automated input and / or storage of specifications of weld contact devices, electrolyte media, and material materials that can be used with the device, as well as corresponding operating parameters of the power supply device in the parameter memory, so that an optimized presetting of the cleaning current can be provided. The input device can be designed internally within the device or structurally separate from it and connectable via a wireless or wired interface, e.g., in the form of an app on a smartphone or tablet that can be coupled to the current control device via Wi-Fi or Bluetooth. Based on the presetting, adaptive control can be carried out quickly and efficiently, depending on the application.This advantageously further improves operational efficiency.

[0028] Preferably, the input device comprises a wired or wireless communication interface to an online database and / or to a portable data terminal such as a smartphone, tablet, or similar. This allows the specifications to be quickly and user-friendly imported into the input device. This advantageously further increases user-friendliness and operational efficiency.

[0029] In the application, it can be provided that the weld seam contact device comprises at least one position sensor that detects a position of the weld seam contact device on the workpiece, and that the position sensor is connected to the current control device, so that the current control device can provide adaptive control of the cleaning current output depending on the position of the weld seam contact device on the workpiece. Depending on the position or inclination (angle) of the weld seam contact device on the weld seam or the workpiece, the effective contact area and thus the total electrical resistance varies, which - as already discussed - influences the current output. By incorporating this parameter into the adaptive control, its precision is advantageously further increased.

[0030] The invention can advantageously be used for electrochemically cleaning, polishing, marking, and passivating weld seams of a workpiece using a weld seam cleaning device. In particular, the previously discussed weld seam cleaning device according to the invention is used for this purpose.For this purpose, the weld seam cleaning device comprises a power supply device, in particular a power supply unit, a weld seam contact device, in particular a contact brush or carbon fiber brush, and an electrolyte, wherein the weld seam contact device is provided with an electrical cleaning energy, which comprises a cleaning current intensity, a cleaning voltage, a cleaning current power and a cleaning current density, by the power supply device at least by scaling, preferably by converting and / or commutation, and wherein the cleaning energy is transferred to the weld seam by means of the weld seam contact device and the weld seam is cleaned by interaction with the electrolyte and the cleaning energy.

[0031] According to the invention, a current control device regulates the cleaning energy during normal operation of the power supply device by controlling at least one component, in particular an inverter, of the power supply device, preferably in an automated / automatic, adaptive, and highly dynamic manner based on at least one property of the weld seam contact device, the electrolyte, and / or the workpiece material. This results in the advantages already mentioned above.

[0032] In the application, it can be provided that the current control device is connected to at least one current and / or voltage sensor of the power supply device, which is preferably arranged in a DC intermediate circuit of an output side of the power supply device, and wherein the cleaning current power is parameterizable and the current control device regulates the cleaning current power, in particular current intensity and / or voltage level, essentially constantly within the framework of the adaptive control. This results in the advantages already mentioned above.

[0033] Alternatively, the current and / or voltage sensor can directly measure the output voltage and current supplied to the weld contact device, thereby directly detecting the power output of the current control device. Alternatively, the input current and / or input voltage can also be measured. If necessary, current and voltage sensors can be provided at various points in the input and / or output circuit to provide highly dynamic and precise current control.

[0034] In the application, the current control device can be provided to dynamically adjust a DC amplitude curve or AC amplitude shape of the cleaning current within the framework of adaptive control, in particular by providing adaptive PWM (pulse width modulation) of the cleaning current and an adaptive PWM clock frequency. This results in the advantages already mentioned above.

[0035] In the application, it can be provided that the current control device comprises a parameter memory, wherein at least one property of the weld seam contact device, the electrolyte, and / or the workpiece material is stored in the parameter memory, and the cleaning current density is dynamically controlled by the current control device depending on the parameters stored in the parameter memory, in particular the electrical resistance of a contact surface of the weld seam that can be contacted by the weld seam contact device, the electrolyte, and / or the weld seam contact device, and / or the dimensions of the contact surface. This results in the advantages already mentioned above.

[0036] In the application, it can be provided that electrolyte is automatically conveyed from an electrolyte reservoir, preferably formed or arranged internally in the weld seam cleaning device, to the weld seam contact device, and wherein the current control device relates the cleaning current output to a quantity of electrolyte delivered from the electrolyte reservoir. Preferably, the weld seam contact device comprises at least one position sensor that detects a position of the weld seam contact device on the workpiece, and the position sensor is connected to the current control device, so that the current control device performs adaptive control of the cleaning current output depending on the position of the weld seam contact device on the workpiece and / or depending on the quantity of electrolyte delivered. This results in the advantages already mentioned above.

[0037] In the application, it can be provided that a plurality of weld contact devices and / or electrolyte media can be used with the device, wherein at the beginning of the intended operation of the device, a selected weld contact device and / or an electrolyte media to be used is arranged in the device. This results in the advantages already mentioned above.

[0038] In the application, the power supply device can be designed as a switching power supply, wherein the switching power supply has a switching frequency of at least ≥ 100 kHz, preferably wherein the current control device and the power supply device regulate output ripple in the cleaning voltage of less than 2000 mV peak to peak and maintain a control tolerance of the cleaning current and the cleaning voltage of less than ±1.5%. This results in the advantages already mentioned above.

[0039] In the application, it can be provided that the current control device comprises an input device, in particular an at least partially digital one, for the manual and / or automated input and / or storage of specifications of weld contact devices, electrolyte media, and material materials that can be used with the device, as well as corresponding operating parameters of the power supply device in the parameter memory, and provides an optimized presetting of the cleaning energy based on the specifications and operating parameters, preferably wherein the input device enables a wired or wireless communication interface to a database on the Internet and / or to a portable data terminal such as a smartphone, tablet, or the like. This results in the advantages already mentioned above.

[0040] The application may provide for the specifications and operating parameters to be entered manually by a user into the parameter memory and / or to be automatically retrieved or determined from a database stored internally within the device or in an external network, particularly the Internet, using an identification feature, in particular a QR code or RFID tag. This results in the advantages already mentioned above. DRAWINGS

[0041] Further advantages will become apparent from the accompanying drawing description. The drawings illustrate exemplary embodiments of the invention. The drawings, the description, and the claims contain numerous features in combination. Those skilled in the art will also expediently consider the features individually and combine them into useful further combinations.

[0042] They show: Fig. 1 A highly simplified schematic representation of an advantageous weld seam cleaning device according to a preferred embodiment, Fig. 2 the weld seam cleaning device according to a further embodiment, Fig. 3 the weld seam cleaning device according to a further embodiment, Fig. 4 the weld seam cleaning device according to a further embodiment, Fig. 5 the weld seam cleaning device according to a further embodiment, Fig. 6 a schematic diagram illustrating various potential adaptive control options for the weld seam cleaning device, and Fig. 7 a schematic diagram illustrating various balance functions for controlling the weld seam cleaning device.

[0043] In the figures, similar elements are numbered with the same reference numerals. The figures are merely examples and are not to be construed as limiting.

[0044] Fig. Figure 1 shows a highly simplified schematic representation of an advantageous weld seam cleaning device 10 according to a preferred embodiment. The weld seam cleaning device 10 is designed to electrochemically clean a weld seam 11 of a workpiece and, in particular, to additionally polish, mark, and / or passivate it.

[0045] The welder cleaning device 10 comprises as essential components a power supply device 12 and a weld seam contact device 14. According to the present embodiment, the power supply device 12 is designed as a switched-mode power supply and the weld seam contact device 14 as a contact brush.

[0046] The power supply device 12 is designed to provide electrical cleaning energy 16, at least by scaling and, in this case, also by converting and / or commutating the weld seam contact device 14. In conjunction with an electrolyte 18 included in the weld seam cleaning device 10, the weld seam contact device 14 is designed to transfer the cleaning energy 16, preferably by contact, to the weld seam 11 to be cleaned. In this case, in conjunction with the electrolyte 18 and the cleaning energy 16, an electrochemical reaction occurs, through which the weld seam 11 is cleaned.

[0047] In order to enable high-quality, efficient and constant or reliable cleaning of the weld seam 11, the present weld seam cleaning device 10 is advantageously provided to comprise a current control device 20.

[0048] The current control device 20 is designed to adaptively control the cleaning energy 16 provided by the power supply device 12 during intended operation of the power supply device 12, i.e., inter alia, during a corresponding cleaning process of the weld seam 11, based on at least one property of the weld seam contact device 14, the electrolyte 18 and / or the material from which the weld seam 11 or the workpiece is made.

[0049] The electrical cleaning energy 16 comprises or is composed of the essential electrical variables of a cleaning current I, a cleaning voltage U, a cleaning current power P, and a cleaning current density J. These electrical variables can be highly dynamically controlled during the adaptive control carried out or provided by the current control device 20, i.e., they can be adapted at high frequency in time intervals of less than 10 µs or adaptively adjusted with respect to the currently present variables that impair the effectiveness of the cleaning energy 16, in particular electrical resistances R. In this regard, the current control device 20 is designed to control the cleaning energy 16 within the framework of various control modes, in which at least one of the aforementioned electrical variables is dynamically influenced and / or kept constant. The control modes will be described later with reference to Fig. 6 is explained in more detail.

[0050] The power supply device 12, which is embodied here as a switched-mode power supply with a switching frequency of at least ≥100 kHz, comprises a plurality of electrical components or parts that are structurally or technically divided into a primary side 22 and a secondary side 24, or are divided into the primary side 22 and the secondary side 24. The primary side 22 and the secondary side 24 are earthed from one another by an isolating transformer 26, so that the secondary side 24 is unearthed and thus safe to handle.

[0051] The primary side 22 comprises a first rectifier 28, a first inverter 30, and a stabilization and filter unit 32, which in this case consists of a line filter 34 and a power correction filter 36 in the form of a PFC (Power Factor Compensation). The secondary side 24 comprises a second rectifier 38 and a second inverter 40 as electrical components.

[0052] By means of the aforementioned electrical components of the power supply device 12, the latter is designed to convert an electrical output energy 44 originating from an external energy source 42, in this case a battery and / or a power grid, into the electrical cleaning energy 16 through a series of electrical transformation steps, wherein in particular an output voltage and an output current of the output energy 44 are electrically modified.

[0053] During the transformation, the stabilization and filter unit 32 filters out interference frequencies from the voltage supply device 12 in the direction of the energy source 42. The first rectifier 28 converts the output energy 44, which normally originates as alternating current from the energy source 42, into a direct current, and the first inverter 30 then converts it back into an alternating current with a higher frequency. During this conversion, the output current and / or output voltage can be scaled and commutated.Subsequently, further scaling and / or correction can be performed by the isolation transformer 26, whereupon the output energy 44 is again electrically transformed and, in particular, further scaled on the secondary side 24 by the second rectifier 38 and the second inverter 40. Finally, the cleaning energy 16, which has been cleaned of interference frequencies and electrically modified, in particular upscaled, is obtained and provided to the weld seam contact device 14.

[0054] The current control device 20 can, within the scope of the adaptive control, control at least one of the components of the power supply device 12 in such a way that the previously described transformation of the output energy 44 into the cleaning energy 16 is adapted as needed or dynamically. According to the Fig. In the preferred embodiment shown in Figure 1, the first inverter 30 is controlled for this purpose. The control takes place depending on various parameters, which in particular include an electrical resistance R. The electrical resistance can be associated with a contact surface of the weld 11, the electrolyte 18, and / or the weld contact device 14, which can be contacted by the weld contact device 14.

[0055] To ensure particularly precise control or to obtain feedback on the current state of the at least partially converted output energy 44, the current control device 20 is electrically connected to a current sensor 46 and a voltage sensor 48. The sensors 46, 48 are arranged in a direct current (DC) intermediate circuit of the secondary side 24 of the power supply device 12. The feedback obtained by the sensors 46, 48 is used by the current control device 20 for dynamic or adaptive control of the power supply device 12.

[0056] The weld seam cleaning device 10 can comprise an input device 50 as a further component. By means of the input device 50, specifications of weld seam contact devices 14, electrolyte media 18, and / or material materials that can be used with the weld seam cleaning device 10, as well as corresponding operating parameters of the power supply device 12, can be manually and / or automatically entered into a parameter memory of the current control device 20 and / or stored there. Depending on these specifications or operating parameters, an optimized presetting of the cleaning energy 16 can be provided. The input device 50 is, as in Fig. 1, indicated by an arrow as an example, is connected to the current control device 20 for communication purposes.

[0057] Preferably, the input device 50 comprises a communication interface (not shown in detail here for reasons of clarity) to a database on the Internet and / or a portable data terminal, via which the specifications and operating parameters can be automatically implemented in the parameter memory.

[0058] The weld seam cleaning device 10 can further comprise a conveying device 52 for automatically conveying the electrolyte 18. The conveying device 52 can convey the electrolyte 18 from an electrolyte reservoir, preferably formed or at least arranged internally in the weld seam cleaning device 10, to the weld seam contact device 14. In particular, an adaptive control of the conveyed quantity of the electrolyte 18 can be provided, which can be monitored, for example, by means of monitoring sensors. The current control device 20 is configured to relate the cleaning energy 16 provided by the power supply device 12, in particular with regard to its cleaning current power P, to a quantity of the conveyed electrolyte 18 and, based thereon, to adapt the adaptive control of the cleaning energy 16.

[0059] As an alternative to the conveying device 52, the electrolyte agent 18 can also be applied manually to the weld seam contact device 14.

[0060] The Fig. 2 to 5 each show a further embodiment of the previously described Fig. 1 discussed weld seam cleaning device 10. Identical elements are therefore provided with the same reference numerals, whereby only the respective differences will be discussed below.

[0061] In the Fig. 2 shown further embodiment is in contrast to the one in Fig. In the preferred embodiment shown in Figure 1, the current control device 20, as part of the adaptive control for dynamically adjusting the cleaning energy 16, no longer controls the first inverter 30 arranged on the primary side 22, but rather the second inverter 40 arranged on the secondary side 24. On the secondary side 24, a smoothing choke 54 is connected downstream of the second inverter 40 on the output side. The smoothing choke 54 reduces voltage peaks that can act on the weld seam 11 via the weld seam contact device 14 and on the electrolyte 18 and cause local overheating.

[0062] In the Fig. In the further exemplary embodiment shown in Figure 3, it is again provided that the current control device 20 controls both the first inverter 30 and the second inverter 40 as part of the adaptive control for dynamically adjusting the cleaning energy 16. On the secondary side 24, a smoothing choke 54 is connected in the intermediate circuit between the second rectifier 38 and the second inverter 40, which suppresses the transmission of current peaks to the output-side cleaning energy 16.

[0063] The Fig. The further embodiment of the weld seam cleaning device 10 shown in Figure 4 differs from the previous ones, previously described with reference to the Fig. 1 to 3, in that only the first rectifier 28 and the first inverter 30 are provided on the primary side 22, and thus no stabilization and filter unit 32. Furthermore, no further components, i.e., neither the second rectifier 38 nor the second inverter 40, are provided on the secondary side 24. This embodiment results in a particularly simple and thus cost-effective and robust design of the power supply device 12. The entire cleaning energy is supplied by the isolating transformer 26 directly to the weld seam contact device 14.

[0064] The Fig. The further embodiment of the weld seam cleaning device 10 shown in Figure 5 differs from the previous embodiments in that only the stabilization and filter unit 32 is provided on the primary side 22, but not the first rectifier 28 and the first inverter 30. On the secondary side 24, the second rectifier 38 and the second inverter 40 are still provided. The isolating transformer thus initially transmits the output energy at the mains frequency to the secondary side, with conversion of the cleaning energy only taking place on the secondary side. This embodiment also enables a particularly simple and therefore cost-effective design of the power supply device 12 and simultaneously offers the possibility of filtering interference frequencies. For further suppression of interference frequencies and voltage peaks on the cleaning energy 16, in combination with the embodiments of the Fig. 2 and Fig. 3 both a smoothing choke 54 in the intermediate circuit, between the second rectifier 38 and the second inverter 40 and on the output side for the direct delivery of the cleaning energy 16 to the weld seam contact device 14 is provided.

[0065] Fig. Figure 6 shows a simplified diagram of the previously mentioned various control modes for the cleaning energy 16 that can be provided by the current control device 20. The cleaning current U is plotted on the Y-axis of the diagram, and the cleaning current I is plotted on the X-axis.

[0066] In a first control mode (P-constant), it is provided that the cleaning current power P of the cleaning energy 16 is kept permanently constant over the course of the cleaning process as part of the adaptive control. The cleaning current power P results from the product of the cleaning current I and the cleaning voltage U according to the formula P=U*I. Thus, in this mode, it is provided that the cleaning voltage U and the cleaning current I are dynamically controlled over the course of the cleaning process, i.e., increased or decreased as needed depending on one another (due to respective fluctuations), so that the cleaning current power P remains permanently constant. In this regard, parameters dependent on the electrolyte 18 and the weld seam contact devices 14 used are taken into account in particular.

[0067] In a second control mode (I-constant), the cleaning current density J of the cleaning energy 16 is kept permanently constant. The cleaning current density J results from the quotient of the incident cleaning current intensity I on the contact surface A of the weld seam 11 according to the formula J=I / A. The contact surface A varies during the cleaning process depending on the position or angle of the weld seam contact device 14 as well as based on intrinsically present topological changes in the surface of the weld seam 11 (hills and valleys). Thus, in this control mode, the cleaning current intensity I is also varied or dynamically adjusted during the cleaning process depending on the changes in the contact surface A in order to keep the cleaning current density J constant.

[0068] In a third control mode (U-constant), the cleaning voltage U remains essentially constant during the cleaning process, and the cleaning current I is dynamically adjusted depending on the electrical resistance R of the contact surface of the weld seam 11 and / or the weld seam contact device 14, which continuously varies during the cleaning process. According to Ohm's law, the cleaning voltage U results from the product of the cleaning current I and the currently existing electrical resistance R according to the formula U=I*R.If the electrical resistance R varies during the cleaning process, which naturally occurs, as with the cleaning current density J, due to the natural changes in the topology of the weld seam 11 and the position of the weld seam contact device 16, the cleaning current intensity I must also be adjusted depending on the resistance R in order to maintain the intended constant cleaning voltage U.

[0069] All control modes advantageously ensure that sufficient cleaning performance can be consistently provided, with the cleaning energy 16 always being provided at the optimal level to achieve the best possible cleaning result. The adaptive control provided by the current control device 20 thus enables highly dynamic and precise control or adjustment of the cleaning energy 16 to the current cleaning conditions.

[0070] Fig.Figure 7 shows a highly simplified diagram for the adaptive control of a DC amplitude curve or an AC amplitude shape of the cleaning current I by the current control device. This diagram shows the temporal profile of an output voltage resulting from pulse width modulation (PWM) of control signals from electronic power switches such as IGBTs, MOSFETs, SICFETs, or similar devices of the second, output-side output inverter 40. The output voltage is composed of temporal sequences of voltage pulses with positive or negative polarity and can simulate a voltage balance function, which, as the left-hand figure shows, can have a positive DC voltage component.A DC-free output voltage with equal numbers of positive and negative polarity voltage pulses can also be provided, as shown in the middle diagram, or a DC-biased output voltage with negative polarity, as shown in the left side of the figure. The PWM output voltage curve can be optimized depending on the electrolyte used, the material being processed, and the contact brush used. With higher frequency, with higher frequency. List of reference symbols 10 Weld seam cleaning device 11 Weld seam 12 Power supply device 14 Weld seam contact device 16 Cleansing energy 18 electrolyte agents 20 Current control device 22 Primary page 24 Secondary page 26 Isolation transformer 28 First rectifier 30 First inverter 32 Stabilization and filter unit 34 line filters 36 power correction filters 38 Second rectifier 40 Second inverter 42 Energy source 44 Output energy 46 Current sensor 48 Voltage sensor 50 Input device 52 conveyor system 54 smoothing choke QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 20 2021 103 661 U1

[0007]

Claims

[1] Weld seam cleaning device (10) for electrochemically cleaning, polishing, marking and passivating a weld seam (11) of a workpiece, in particular a weld seam cleaner, comprising a power supply device (12), in particular a power supply unit, a weld seam contact device (14), in particular a contact brush or carbon fiber brush, and an electrolyte (18), wherein the power supply device (12) is designed to provide electrical cleaning energy (16) comprising a cleaning current intensity (I), a cleaning voltage (U), a cleaning current power (P) and a cleaning current density (J) to the weld seam contact device (14) at least by scaling, preferably by converting and / or commutating, and the weld seam contact device (14) is designed to supply the cleaning energy (16), preferably by contact,to transfer to the weld seam (11) and to clean the weld seam (11) by interaction with the electrolyte (18) and the cleaning energy (16), , characterized by that a current control device (20) is included, which is designed to regulate the cleaning energy (16), preferably automatically / automatically, adaptively on the basis of at least one property of the weld seam contact device (14), the electrolyte (18), and / or the workpiece material during intended operation of the power supply device (12) by controlling at least one component, in particular an inverter (30, 40), of the power supply device (12). [2] Weld seam cleaning device according to claim 1, characterized byin that the current control device (20) is connected to at least one current and / or voltage sensor (46, 48) of the power supply device (12), which is preferably arranged in a DC intermediate circuit of a secondary side (24) of the power supply device (12), and wherein the cleaning current power (P) is parameterizable and the current control device (20) is designed to keep the cleaning current power (P), in particular current intensity and / or voltage level, essentially constant and controllable within the scope of the adaptive control. [3] Weld seam cleaning device according to one of the preceding claims, characterized byin that the current control device (20) is designed to dynamically adjust a direct current amplitude curve or an alternating current amplitude shape of the cleaning current intensity (I) within the scope of the adaptive control, in particular to provide an adaptive PWM modulation (pulse width modulation) of the cleaning current intensity (I) and an adaptive PWM clock frequency. [4] Weld seam cleaning device according to one of the preceding claims, characterized byin that the current control device (20) comprises a parameter memory which is designed to store at least one property of the weld seam contact device (14), the electrolyte (18), and / or the workpiece material, and the current control device (20) is designed, within the scope of the adaptive control, to dynamically control the cleaning current density (J) of the cleaning energy (16) as a function of the parameters stored in the parameter memory, in particular the electrical resistance of a contact surface of the weld seam (11), the electrolyte (18) and / or the weld seam contact device (14) that can be contacted by the weld seam contact device (14), and / or the dimensioning of the contact surface. [5] Weld seam cleaning device according to one of the preceding claims, characterized byin that the power supply device (12) comprises at least one isolating transformer (26), at least one, preferably two, rectifiers (28, 38) and at least one, preferably two, inverters (30, 40), wherein the isolating transformer (26) is preferably operable in push-pull mode, and wherein furthermore preferably at least one stabilization and filter unit (32), in particular mains filter (34) and / or power factor correction filter (36) for filtering interference frequencies is included. [6] Weld seam cleaning device according to one of the preceding claims, characterized by that the power supply device (12) is designed as a switching power supply, wherein the switching power supply has a switching frequency of at least ≥ 100kHz. [7] Weld seam cleaning device according to claim 6, characterized bythat the current control device (20) and the power supply device (12) are designed to provide output ripple in the cleaning voltage (U) of less than 2000mV peak to peak and a control tolerance of the cleaning current intensity (I) and the cleaning voltage (U) of less than ±1.5%, wherein at least one smoothing choke (54) is preferably switched on in the output current circuit, in particular on the secondary side (24) of the isolating transformer (26). [8] Weld seam cleaning device according to one of the preceding claims, characterized byin that the weld seam cleaning device (10) comprises a conveying device (52) for automatically conveying the electrolyte (18) from an electrolyte reservoir, preferably formed or arranged internally in the weld seam cleaning device (10), to the weld seam contact device (14), and wherein the current control device (20) is designed to relate the cleaning current power (P) to a quantity of the conveyed electrolyte (18) from the electrolyte reservoir. [9] Weld seam cleaning device according to claim 4, characterized byin that the current control device (20) comprises an input device (50), in particular an at least partially digital input device, for the manual and / or automated input and / or storage of specifications of weld seam contact devices (14), electrolyte agents (18) and material materials that can be used with the weld seam cleaning device (10), as well as respective corresponding operating parameters of the power supply device (12) in the parameter memory, so that an optimized presetting of the cleaning energy (16), in particular with regard to its cleaning current intensity (I), cleaning voltage (U), cleaning current power (P) and / or cleaning current density (J), can be provided, preferably wherein the input device (50) comprises a wired or wireless communication interface to a database on the Internet and / or to a portable data terminal such as a smartphone, tablet or the like. [10] Weld seam cleaning device according to one of the preceding claims, characterized by that the weld seam contact device (14) comprises at least one position sensor which detects a position of the weld seam contact device (14) on the workpiece, and that the position sensor is connected to the current control device (20) so that an adaptive control of the cleaning current power (P) can be provided by the current control device (20) as a function of the position of the weld seam contact device (14) on the workpiece.

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