Weld cleaning device and method for cleaning a weld using such a weld cleaning device

Abstract

The invention relates to a weld cleaning device (10) and a method for electrochemically 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 (11) and to clean the weld (11) by interaction with the electrolyte medium (18) and the cleaning energy (16). It is provided that a current control device (20) is included which is designed to control the cleaning energy (16), preferably automatically / self-regulating, on the basis of at least one property of the weld 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 cleaning device for electrochemical cleaning, polishing, marking and passivating of a weld seam of a workpiece, in particular a weld cleaner.

[0002] Furthermore, the invention relates to a method for electrochemically cleaning, polishing, marking and passivating welds of a workpiece using such a weld cleaning device. STATE OF THE ART

[0003] 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 possibly also aesthetic requirements, such as anti-corrosive properties and / or sterility, of the weld seam or the workpiece, depending on the application.

[0004] In the prior art, a number of possibilities exist in this regard, which include in particular mechanical surface treatments as well as purely chemical or electrochemical surface treatments. Electrochemical cleaning of weld seams has proven to be particularly practical in this context.

[0005] Electrochemical cleaning typically uses a specialized weld cleaning device, which, in addition to cleaning, usually also enables polishing, marking and passivation of the welds.

[0006] In principle, such a weld cleaning device comprises a power supply, a weld contact device, and an electrolyte. The power supply converts electrical energy, usually mains current, through a series of electrical conversion steps, mostly scaling and conversion, into electrical cleaning energy with a modified, usually increased, current and / or voltage compared to the initial energy. This energy is then supplied to the weld contact device and the workpiece with the weld joint being cleaned. The cleaning energy is transferred to the weld seam via contact through the weld contact device. The weld contact device—usually a conductive contact brush—is wettable with the electrolyte, often achieved by wrapping a felt pad soaked in the electrolyte around it.When the weld seam is touched, an electrical cleaning circuit is closed between the weld seam contact device and the workpiece, thereby allowing the electrolyte to react electrochemically with the metallic material of the weld seam. This reaction, usually a reduction of the surface oxide layer, cleans the weld seam by scanning or moving along it with the weld seam contact device, resulting in electrochemical contact and, as a rule, passivation.

[0007] The problem with this type of surface treatment is to provide enough electrical energy for the effect while simultaneously limiting the energy so that the electrolyte is not overheated by excessive electrical power and thus burned and / or the weld seam is damaged or further contaminated.

[0008] A weld cleaning device of this type is known, for example, from DE 20 2021 103 661 U1. This patent discloses an arc welding machine with a cleaning function, wherein a power supply unit provides both an electric welding current for the welding process and an electric cleaning energy for the subsequent cleaning of the weld. To avoid damage to the weld due to excessive electrical power, as discussed above, the known solution provides that the maximum power remains within a predetermined, potentially safe range by setting or limiting the current and voltage. For this purpose, at the beginning of the cleaning process, the current and voltage are set to a specific, relatively low value within a defined range and kept constant throughout the entire cleaning process.In other words, the maximum power output is deliberately kept comparatively low and constant, or throttled, to fundamentally eliminate the risk of any potentially excessive current from the outset. This ensures that the current output never reaches, or can reach, a potentially harmful level.

[0009] A disadvantage of this well-known solution, however, is that by deliberately throttling the current to a relatively low level, the corresponding cleaning potential or cleaning performance increasingly fails to meet the high requirements and is regularly insufficient, or reduces the cleaning speed. Furthermore, a consistent or uniform cleaning result can rarely be achieved. This is because, according to Ohm's law, the effective current depends on the electrical resistance of the contact surface between the weld and the weld contact device, as well as that of the electrolyte. Since manual operation typically involves...When moving along the weld seam, the user, due to natural tremors, tilt, and topological irregularities of the weld surface, can only maintain a consistently uniform contact area between the weld contact device and the workpiece with difficulty. As a result, the effective electrical resistance varies continuously during the cleaning process. Consequently, the current also varies continuously, leading to uneven cleaning performance.

[0010] Thus, the known solution not only often results in 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.

[0011] The object of the invention is to provide an improved weld cleaning device and a method for its use, in which not only a reliable, sufficient, but also a constant cleaning performance is provided.

[0012] This problem is solved by a weld cleaning device and a method according to the independent claims. Advantageous embodiments of the invention are the subject of the dependent claims. REVELATION OF THE INVENTION

[0013] The invention relates to a weld cleaning device for the electrochemical cleaning, polishing, marking, and passivation of a weld seam of a workpiece, in particular a weld cleaner. The weld cleaning device comprises a power supply unit, in particular a power supply, a weld contact device, in particular a contact brush or carbon fiber brush, and an electrolyte. The power supply unit is configured to provide the weld contact device with electrical cleaning energy, comprising a cleaning current, a cleaning voltage, a cleaning power, and a cleaning current density, at least by scaling, preferably by conversion and / or commutation.The weld contact device is designed to transfer the cleaning energy, preferably by contact, to the weld and to clean the weld by interaction with the electrolyte medium and the cleaning energy.

[0014] The electrical cleaning energy is obtained by converting an electrical output energy, particularly one originating from a power grid. This conversion is performed by the power supply unit 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 current I, namely I=P / U and I=U / R, - a cleaning voltage that can be physically described by the known general formulas for (current) voltage U, namely U=P / I and U=R*I, - a cleaning current power, which can be physically determined by the known general formulas for power P, namely P=U*I, P=R·I 2 and P=U 2 / R, is describable, - and a cleaning current density that can be physically described by the known general formulas for current density J, namely J=I / A(area).

[0015] According to the invention, a current control device is included which is designed to control the cleaning energy, preferably automatically / self-regulating, on the basis of at least one property of the weld 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.

[0016] In other words, the invention provides an adaptive control function for the cleaning energy, which, during operation of the weld cleaning device, i.e., during the cleaning process, continuously and highly dynamically regulates the cleaning energy depending on the current properties of the components involved. This allows the supplied cleaning energy to be adapted to the individual, current conditions in real time. Depending on preference, the aforementioned components of the cleaning energy are controlled, namely cleaning current, cleaning voltage, cleaning 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 ensures that the optimal cleaning energy for the current conditions is available at all times and maintained at a constant level.Furthermore, in contrast to the known solution, no fundamental throttling of current and voltage is carried out from the outset to avoid excessive current power, since the current power can be adaptively regulated depending on the current conditions and is therefore always kept at a safe level.

[0017] The weld cleaning device according to the invention enables precise adjustment of the cleaning current in highly dynamic and consistent quality, even with complex weld geometries, different materials, electrolytes and different weld contact devices, thus achieving efficient, time-saving processing with consistent and high-quality cleaning results.

[0018] Advantageously, the solution according to the invention reliably ensures sufficient cleaning performance. Because a fundamental throttling is eliminated, high current and voltage values ​​– potentially dangerous in known solutions – can be set to achieve high cleaning performance. The adaptive or highly dynamic control ensures that the current is always maintained at a safe and optimal level for the current conditions. The solution according to the invention thus advantageously enables not only a surprisingly high-quality, but also an effective and consistent cleaning result.

[0019] According to a preferred embodiment, the current control device can be connected to at least one current and / or voltage sensor of the power supply unit, which is preferably arranged in a DC intermediate circuit of a secondary side of the power supply unit. The cleaning current is parameterizable, and the current control device is configured to maintain the cleaning current, in particular the current and / or voltage level, at a substantially constant level within the framework of adaptive control. The parameters of the cleaning current depend in particular on the electrolyte and the weld contact device used. As mentioned at the outset, the cleaning energy is provided by converting the output energy via the power supply unit.Naturally, fluctuations in the output values, particularly output current and voltage, can occur, for example due to mains voltage fluctuations. These fluctuations can be taken into account by the sensor(s) for adaptive control. Furthermore, incorporating the cleaning current parameters enables the aforementioned dynamic adjustment of the cleaning current to the current conditions, thus ensuring that the cleaning current and therefore the cleaning energy remain constant. This advantageously provides a reliable and precise adaptive control method, thereby guaranteeing consistently high cleaning results.

[0020] According to a preferred embodiment, the current control device can be configured to dynamically adjust the DC amplitude profile or the AC amplitude waveform of the cleaning current within the framework of adaptive control, in particular by providing adaptive PWM modulation (pulse width modulation) of the cleaning current and an adaptive PWM clock frequency. Advantageously, this allows for comparatively simple yet effective and precise control of the cleaning energy.

[0021] According to a preferred embodiment, the current control device may include a parameter memory configured to store at least one property of the weld contact device, the electrolyte, and / or the workpiece material. Within the framework of adaptive control, the current control device is configured to dynamically regulate the cleaning current density of the cleaning energy as a function of the parameters stored in the parameter memory, in particular the electrical resistance of a contact surface of the weld, the electrolyte, and / or the weld contact device that can be contacted by the weld contact device, and / or the dimensions of the contact surface. As previously mentioned, the cleaning current density is calculated according to the formula J = I / A as the quotient of the (incident) current I per contact area A, for example, with the units amperes / cm². 2The parameters to be included in the adaptive or dynamic control, in particular electrical resistances and the corresponding optimal cleaning current, can be pre-stored in the parameter memory. This allows, in principle, a preset cleaning current or current density to be applied for the currently used weld contact device, the currently used electrolyte, the material being processed, etc. Within the framework of the adaptive or dynamic control, the cleaning current density is kept constant based on this preset, for example, by varying the cleaning current in relation to the constantly changing contact area (especially due to topological factors). Advantageously, this also ensures a consistent cleaning result.

[0022] According to a preferred embodiment, the power supply unit may comprise at least one isolation transformer, at least one, preferably two, rectifiers, and at least one, preferably two, inverters, preferably including at least one stabilization and filtering unit, in particular a mains filter and / or power factor compensation (PFC) filter for filtering interference frequencies. The isolation transformer ensures sufficient safety for the user at all times. The rectifiers and inverters enable a particularly efficient and effective conversion of the output current and voltage into the cleaning current and voltage, with the particular possibility of significant scaling. A push-pull circuit is preferably provided for operating the isolation transformer in order to transmit the highest possible power.The stabilization and filtering unit further filters out interference frequencies, making the conversion even more stable and ensuring a constant level of cleaning current and voltage. The power supply unit is also particularly efficient and reliable.

[0023] According to a preferred embodiment, the power supply unit can be designed as a switched-mode power supply, wherein the switched-mode power supply unit has a switching frequency of at least ≥ 100 kHz. This embodiment of the power supply unit enables a particularly fast and precise response or adaptation to the rapidly changing parameters or current conditions during the cleaning process. Advantageously, this allows for a particularly effective and highly dynamic adaptive control.

[0024] According to a preferred embodiment, 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%. Advantageously, this makes the adaptive control even more precise and dynamic.

[0025] Preferably, a smoothing choke can be integrated into the output current circuit, particularly on the secondary side of the isolation transformer. The smoothing choke ensures that the output current is smooth 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.

[0026] According to a preferred embodiment, the device may include a conveying unit for automatically conveying the electrolyte from an electrolyte reservoir, preferably formed or arranged internally within the device, to the weld contact device, and wherein the current control unit is configured to relate the cleaning current power to the quantity of electrolyte conveyed from the electrolyte reservoir. The electrolyte may, for example, already be present or available internally within the device. Alternatively, external or manual application of the electrolyte, for example by means of an impregnated felt pad, is conceivable. The delivery rate of the electrolyte preferably remains constant with respect to the processing progress. In this respect, monitoring sensors for controlling the delivery rate of electrolyte may optionally be provided. The absolute orThe 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 monitoring of the cleaning energy output or the processing progress. A demand-based variation of the flow rate is also conceivable, and possibly even self-adjustment of the absolute quantity analogous to the adaptive control of the cleaning energy. As mentioned previously, the electrolyte – both in terms of its properties and its quantity – can also be included in the parameters used for the adaptive control, since it influences the electrical resistance. Including the flow rate in the adaptive control can advantageously ensure the maintenance of a consistently high-quality cleaning performance.

[0027] According to a preferred embodiment, the weld contact device and / or the electrolyte can be interchangeable, allowing a variety of weld contact devices and / or electrolytes to be used with the device. Advantageously, this gives the weld cleaning device a particularly wide range of applications.

[0028] According to a preferred embodiment, the current control device may include an input device, particularly at least partially digital, for manually and / or automatically entering and / or storing specifications of weld contact devices, electrolytes, and material components usable with the device, as well as the corresponding operating parameters of the power supply unit in the parameter memory, thus enabling an optimized preset cleaning current. The input device may be integrated into the device or be structurally separate and connectable via a wireless or wired interface, for example, in the form of an app on a smartphone or tablet that can connect to the current control device via Wi-Fi or Bluetooth. Based on the preset, adaptive control can be performed quickly and efficiently, depending on the application.This advantageously further improves operational efficiency.

[0029] Preferably, the input device includes 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 similar device. This allows the specifications to be quickly and easily entered into the input device. Advantageously, this further increases user-friendliness and operational efficiency.

[0030] According to a preferred embodiment, the weld contact device may include at least one position sensor that detects the position of the weld contact device on the workpiece, and the position sensor is connected to the current control device so that the current control device can provide adaptive control of the cleaning current power depending on the position of the weld contact device on the workpiece. Depending on the position or inclination (angle) of the weld contact device on the weld or the workpiece, the effective contact area and thus the total electrical resistance varies, which—as previously discussed—affects the current power. Including this parameter in the adaptive control advantageously further increases its precision.

[0031] In a subordinate aspect, the invention relates to a method for the electrochemical cleaning, polishing, marking, and passivation of welds on a workpiece using a weld cleaning device. In particular, the weld cleaning device according to the invention discussed above is used for this purpose.The weld cleaning device usable in the process comprises a power supply unit, in particular a power supply, a weld contact unit, in particular a contact brush or carbon fiber brush, and an electrolyte medium, wherein the weld contact unit is supplied with electrical cleaning energy, comprising a cleaning current, a cleaning voltage, a cleaning power and a cleaning current density, by the power supply unit at least by scaling, preferably by conversion and / or commutation, and wherein the cleaning energy is transferred to the weld by means of the weld contact unit and the weld is cleaned by interaction with the electrolyte medium and the cleaning energy.

[0032] According to the invention, it is proposed that a current control device, during intended operation of the power supply unit, regulates the cleaning energy, preferably automatically, adaptively, and highly dynamically, based on at least one property of the weld contact device, the electrolyte medium, and / or the workpiece material, by controlling at least one component, in particular an inverter, of the power supply unit. The advantages already mentioned above result from this.

[0033] According to a preferred embodiment, the current control device can be connected to at least one current and / or voltage sensor of the power supply unit, which is preferably arranged in a DC intermediate circuit of an output side of the power supply unit, and wherein the cleaning current power is parameterizable and the current control device, within the framework of adaptive control, regulates the cleaning current power, in particular the current and / or voltage level, to a substantially constant level. The advantages already mentioned above result from this.

[0034] Alternatively, the current and / or voltage sensor can directly detect the output voltage and current supplied to the weld contact device, thus allowing direct measurement of the current control device's power output. Again, alternatively, input current and / or input voltage can be measured. If necessary, current and voltage sensors can be positioned at various points in the input and / or output circuit to provide highly dynamic and precise current control.

[0035] According to a preferred embodiment, the current control device can dynamically adjust the DC amplitude profile or AC amplitude waveform of the cleaning current within the framework of adaptive control, in particular providing adaptive PWM modulation (pulse width modulation) of the cleaning current and an adaptive PWM clock frequency. This results in the advantages already mentioned above.

[0036] According to a preferred embodiment, the current control device may include a parameter memory, wherein at least one property of the weld 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 as a function of the parameters stored in the parameter memory, in particular the electrical resistance of a contact surface of the weld, the electrolyte, and / or the weld contact device that can be contacted by the weld contact device, and / or the dimensions of the contact surface. The advantages already mentioned above result from this.

[0037] According to a preferred embodiment, electrolyte medium is automatically supplied from an electrolyte reservoir, preferably formed or arranged internally within the weld cleaning device, to the weld contact device. The current control device relates the cleaning current to the quantity of electrolyte medium supplied from the electrolyte reservoir. Preferably, the weld contact device includes at least one position sensor that detects the position of the weld contact device on the workpiece, and the position sensor is connected to the current control device so that the current control device adaptively regulates the cleaning current depending on the position of the weld contact device on the workpiece and / or depending on the quantity of electrolyte medium supplied. The advantages already mentioned above arise in this respect.

[0038] According to a preferred embodiment, it can be provided that a variety 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 electrolyte media to be used is arranged in the device. The advantages already mentioned above result from this.

[0039] According to a preferred embodiment, the power supply unit can be designed as a switched-mode power supply, wherein the switched-mode power supply unit has a switching frequency of at least ≥ 100 kHz, preferably wherein the current control unit and the power supply unit 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 cleaning voltage of less than ±1.5%. The advantages already mentioned above result from this.

[0040] According to a preferred embodiment, the current control device may include an input device, particularly at least partially digital, for manually and / or automatically entering and / or storing specifications of weld contact devices, electrolytes, and material materials usable with the device, as well as the corresponding operating parameters of the power supply unit in the parameter memory. Based on these specifications and operating parameters, the device provides an optimized preset cleaning energy, preferably with the input device offering 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 similar device. The advantages already mentioned in advance arise from this.

[0041] According to a preferred further development, it can be provided that the specifications and operating parameters are manually entered into the parameter memory by a user and / or 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

[0042] Further advantages become apparent from the accompanying drawing description. The drawings illustrate exemplary embodiments of the invention. The drawing, the description, and the claims contain numerous features in combination. A person skilled in the art will expediently consider the features individually and combine them into meaningful further combinations.

[0043] They show: Fig. 1 A highly simplified schematic representation of an advantageous weld cleaning device according to a preferred embodiment, Fig. 2 the weld cleaning device according to a further embodiment, Fig. 3 the weld cleaning device according to a further embodiment, Fig. 4 the weld cleaning device according to a further embodiment, Fig. 5 the weld cleaning device according to a further embodiment, Fig. 6 a schematic diagram to illustrate various potential adaptive control options of the weld cleaning device, and Fig. 7 A schematic representation illustrating various balance functions for controlling the weld cleaning device.

[0044] In the figures, similar elements are numbered with the same reference symbols. The figures merely show examples and are not to be understood as limiting.

[0045] Fig. Figure 1 shows a highly simplified schematic representation of an advantageous weld cleaning device 10 according to a preferred embodiment. The weld cleaning device 10 is designed to electrochemically clean a weld 11 of a workpiece and, in particular, to additionally polish, mark, and / or passivate it.

[0046] The welder cleaning device 10 comprises as essential components a power supply unit 12 and a weld seam contact unit 14. According to the present embodiment, the power supply unit 12 is designed as a switching power supply and the weld seam contact unit 14 as a contact brush.

[0047] The power supply unit 12 is configured to provide electrical cleaning energy 16, at least by scaling and, in this case, also by converting and / or commutating the weld contact unit 14. In conjunction with an electrolyte 18 included in the weld cleaning device 10, the weld contact unit 14 is configured to transfer the cleaning energy 16, preferably by contact, to the weld 11 to be cleaned. This results in an electrochemical reaction between the electrolyte 18 and the cleaning energy 16, which cleans the weld 11.

[0048] In order to enable high-quality, efficient and constant or reliable cleaning of the weld seam 11, the present weld seam cleaning device 10 advantageously includes a current control device 20.

[0049] 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., among other things during a corresponding cleaning process of the weld seam 11, on the basis of at least one property of the weld seam contact device 14, the electrolyte medium 18 and / or the material of which the weld seam 11 or the workpiece is made.

[0050] The electrical cleaning energy 16 comprises, or is composed of, the essential electrical quantities of a cleaning current I, a cleaning voltage U, a cleaning power P, and a cleaning current density J. These electrical quantities can be controlled highly dynamically during the adaptive control performed or provided by the current control device 20. This means that they can be adjusted at high frequency in time intervals of less than 10 µs, or adaptively, with respect to the currently present quantities affecting the effectiveness of the cleaning energy 16, in particular electrical resistances R. In this regard, the current control device 20 is configured to control the cleaning energy 16 within the framework of various control modes, in which at least one of the aforementioned electrical quantities is dynamically influenced and / or kept constant. The control modes will be described later with reference to Fig. 6 explained in more detail.

[0051] The power supply unit 12, designed here as a switched-mode power supply with a switching frequency of at least ≥100 kHz, comprises several electrical components or parts which are structurally or by arrangement divided into a primary side 22 and a secondary side 24, or are divided between the primary side 22 and the secondary side 24. The primary side 22 and the secondary side 24 are separated from each other by an isolating transformer 26, so that the secondary side 24 is free of earth and therefore safe to handle.

[0052] 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 mains 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.

[0053] By means of the aforementioned electrical components of the power supply device 12, it 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 by means of a series of electrical transformation steps, wherein in particular an output voltage and an output current of the output energy 44 are electrically modified.

[0054] During the transformation, the stabilization and filter unit 32 filters out interference frequencies from the power supply unit 12 towards 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 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, after which the output energy 44 is electrically transformed again 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, purified of interference frequencies and electrically modified, in particular upscaled, is obtained and supplied to the weld contact device 14.

[0055] Within the framework of adaptive control, the current control device 20 can 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 adjusted as required 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 is dependent 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.

[0056] To ensure particularly precise control and 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 and 48 are arranged in a direct current (DC) intermediate circuit of the secondary side 24 of the power supply unit 12. The feedback obtained by the sensors 46 and 48 is used by the current control device 20 for dynamic or adaptive control of the power supply unit 12.

[0057] The weld cleaning device 10 can include an input device 50 as a further component. Using the input device 50, specifications of weld contact devices 14, electrolyte media 18, and / or material materials usable with the weld cleaning device 10, as well as the corresponding operating parameters of the power supply unit 12, can be manually and / or automatically entered into and / or stored in a parameter memory of the current control unit 20. Depending on these specifications or operating parameters, an optimized preset of the cleaning energy 16 can be provided. The input device 50 is, as described in Fig. 1, exemplified by an arrow, is connected to the current control device 20 via communication technology.

[0058] Preferably, the input device 50 comprises a communication interface to a database on the Internet and / or a portable data terminal, which is not shown in detail here for the sake of clarity, via which the specifications and operating parameters can be automatically implemented in the parameter memory.

[0059] The weld cleaning device 10 can further comprise a conveying device 52 for automatically conveying the electrolyte 18. The conveying device 52 allows the electrolyte 18 to be conveyed from an electrolyte reservoir, preferably formed or at least arranged internally within the weld cleaning device 10, to the weld contact device 14. In particular, adaptive control of the conveying 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 unit 12, in particular with regard to its cleaning current power P, to a quantity of the conveyed electrolyte 18 and, based on this, to adjust the adaptive control of the cleaning energy 16.

[0060] As an alternative to the conveying device 52, the electrolyte medium 18 can also be applied manually to the weld contact device 14.

[0061] The Fig. Figures 2 to 5 each show a further embodiment of the previously described example. Fig. 1. Weld cleaning device discussed 10. Identical elements are provided with the same reference numerals, whereby only the respective differences will now be discussed.

[0062] At the in Fig. The further embodiment shown in 2 differs from the one in Fig. In the preferred embodiment shown in Figure 1, the current control device 20, within the framework of adaptive control for dynamic adjustment of 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. A smoothing choke 54 is connected downstream of the second inverter 40 on the secondary side 24. The smoothing choke 54 reduces voltage spikes that act on the weld seam 11 via the weld seam contact device 14 and on the electrolyte medium 18, which can cause local overheating.

[0063] At the in Fig. In the further embodiment shown in Figure 3, the current control device 20 is again provided that, within the framework of adaptive control for dynamic adjustment of the cleaning energy 16, it controls both the first inverter 30 and the second inverter 40. 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.

[0064] The in Fig. The further embodiment of the weld cleaning device 10 shown in Figure 4 differs from the previous ones, which were previously described using the Fig. In the embodiments discussed in sections 1 to 3, only the first rectifier 28 and the first inverter 30 are provided on the primary side 22, and therefore no stabilization and filter unit 32 is included. Furthermore, no other 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 therefore cost-effective and robust design of the power supply unit 12. The entire cleaning energy is supplied directly to the weld contact unit 14 by the isolation transformer 26.

[0065] The in Fig. The further embodiment of the weld cleaning device 10 shown in Figure 5 differs from the previous embodiments in that only the stabilization and filter unit 32, but not the first rectifier 28 and the first inverter 30, are provided on the primary side 22. On the secondary side 24, the second rectifier 38 and the second inverter 40 are still provided. The isolation transformer thus initially transfers the output energy at the mains frequency to the secondary side, with the conversion of the cleaning energy taking place only on the secondary side. This embodiment also enables a particularly simple and therefore cost-effective design of the power supply unit 12 and simultaneously offers the possibility of filtering interference frequencies. To further suppress interference frequencies and voltage spikes on the cleaning energy 16, 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 contact device 14 are provided.

[0066] Fig. Figure 6 shows a simplified diagram of the previously mentioned different control modes for the cleaning energy 16, which 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 on the x-axis.

[0067] In a first control mode (constant P), the cleaning current P of the cleaning energy 16 is kept constant throughout the cleaning process as part of the adaptive control. The cleaning current P is calculated as the product of the cleaning current I and the cleaning voltage U according to the formula P = U * I. Thus, in this mode, the cleaning voltage U and the cleaning current I are dynamically controlled during the cleaning process, i.e., increased or decreased as needed depending on each other (due to fluctuations), so that the cleaning current P remains constant. In this regard, parameters dependent on the electrolyte 18 and the weld contact devices 14 used are taken into account.

[0068] In a second control mode (constant I), the cleaning current density J of the cleaning energy 16 is kept permanently constant. The cleaning current density J is calculated as the quotient of the incident cleaning current I on the contact area A of the weld 11 according to the formula J = I / A. The contact area A varies during the cleaning process depending on the position or angle of the weld contact device 14 and based on intrinsically present topological changes of the weld 11 surface (peaks and valleys). Therefore, in this control mode, the cleaning current I is also varied or dynamically adjusted during the cleaning process depending on the changes in the contact area A in order to keep the cleaning current density J constant.

[0069] In a third control mode (constant U), the cleaning voltage U remains essentially constant during the cleaning process, while the cleaning current I is dynamically adjusted depending on the electrical resistance R of the contact surface of the weld 11 and / or the weld contact device 14, which varies continuously during the cleaning process. This is because, according to Ohm's law, the cleaning voltage U is the product of the cleaning current I and the current electrical resistance R, as given by 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 11 and the position of the weld contact device 16, then the cleaning current I must also be adjusted as a function of the resistance R in order to maintain the intended constant cleaning voltage U.

[0070] All control modes advantageously ensure that sufficient cleaning performance is constantly available, with the cleaning energy 16 always being available 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 and adjustment of the cleaning energy 16 to the current cleaning conditions.

[0071] Fig.Figure 7 shows a highly simplified scheme for the adaptive control of a DC amplitude waveform or an AC amplitude waveform of the cleaning current I by the current control device. Here, 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 is shown. The output voltage consists of temporal sequences of voltage pulses in positive or negative polarity and can replicate a voltage balance function which, as the left figure shows, can have a positive DC component. If necessary,Alternatively, a DC-free output voltage with an equal number of voltage pulses of positive and negative polarity, as shown in the middle diagram, or a DC-based output voltage with negative polarity, as shown on the left side of the figure, can be provided. The PWM output voltage profile can be optimized depending on the electrolyte used, the material being processed, and the contact brush used. Higher frequencies are also possible. Reference symbol list 10 Weld cleaning device 11 weld seam 12 Power supply unit 14 16 Weld contact device 18 Cleaning energy electrolyte medium 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 mains filters 36 power correction filters 38 Second rectifier 40 Second inverter 42 Energy source 44 Initial energy 46 Current sensor 48 Voltage sensor 50 Input device 52 Funding facility 54 Smoothing choke QUOTES INCLUDED IN THE DESCRIPTION

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

[0000] DE 20 2021 103 661 U1

[0008]

Claims

[1] 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 (11) and to clean the weld (11) by interaction with the electrolyte medium (18) and the cleaning energy (16), , characterized by , that a current control device (20) is included which is designed to control the cleaning energy (16), preferably automatically / self-regulating, on the basis of at least one property of the weld 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). [2] Weld cleaning device according to claim 1, characterized by, 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 and / or voltage level, essentially constant within the framework of adaptive control. [3] Weld cleaning device according to one of the preceding claims, characterized by, that the current control device (20) is designed to dynamically adjust a DC amplitude profile or an AC amplitude shape of the cleaning current (I) within the framework of adaptive control, in particular to provide adaptive PWM modulation (pulse width modulation) of the cleaning current (I) and an adaptive PWM clock frequency. [4] Weld cleaning device according to one of the preceding claims, characterized by, that the current control device (20) comprises a parameter memory configured to store at least one property of the weld contact device (14), the electrolyte medium (18), and / or the workpiece material, and that the current control device (20) is configured, within the framework of 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 (11), the electrolyte medium (18), and / or the weld contact device (14), and / or the dimensioning of the contact surface. [5] Weld cleaning device according to one of the preceding claims, characterized by, that the power supply unit (12) comprises at least one isolation transformer (26), at least one, preferably two, rectifiers (28, 38) and at least one, preferably two, inverters (30, 40), wherein preferably the isolation transformer (26) is operable in push-pull mode, and wherein further 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 cleaning device according to one of the preceding claims, characterized by , that the power supply device (12) is designed as a switched-mode power supply, wherein the switched-mode power supply has a switching frequency of at least ≥ 100kHz. [7] Weld cleaning device according to claim 6, characterized by, that 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 (I) and the cleaning voltage (U) of less than ±1.5%, wherein preferably at least one smoothing choke (54) is switched on in the output current circuit, in particular on the secondary side (24) of the isolation transformer (26). [8] Weld cleaning device according to one of the preceding claims, characterized by, that the weld cleaning device (10) comprises a conveying device (52) for automatically conveying the electrolyte medium (18) from an electrolyte medium reservoir, preferably formed or arranged internally in the weld cleaning device (10), to the weld contact device (14), and wherein the current control device (20) is configured to relate the cleaning current power (P) to a quantity of the conveyed electrolyte medium (18) from the electrolyte medium reservoir. [9] Weld cleaning device according to claim 4, characterized by, that the current control device (20) comprises an input device (50), in particular at least partially digital, for manually and / or automatically entering and / or storing specifications of weld contact devices (14), electrolyte media (18) and material materials usable with the weld cleaning device (10), as well as 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 (I), cleaning voltage (U), cleaning 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 similar. [10] Weld cleaning device according to one of the preceding claims, characterized by , that the weld contact device (14) includes at least one position sensor that detects a position of the weld contact device (14) on the workpiece, and that the position sensor is connected to the current control device (20) so that the current control device (20) can provide adaptive control of the cleaning current power (P) depending on the position of the weld contact device (14) on the workpiece. [11] Method for electrochemically cleaning, polishing, marking and passivating welds (11) of a workpiece by means of a weld cleaning device, in particular a weld cleaning device (10) according to any one of claims 1 to 10, wherein the weld cleaning device (10) comprises a power supply unit (12), in particular a power supply, a weld contact device (14), in particular a contact brush or carbon fiber brush, and an electrolyte (18), wherein the weld contact device (14) is supplied with electrical cleaning energy (16) by the power supply unit (12), 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 wherein the cleaning energy (16) is transferred to the weld (11) by means of the weld contact device (14) and the weld (11) is cleaned by interaction with the electrolyte medium (18) and the cleaning energy (16), characterized by , that a current control device (20) during intended operation of the power supply device (12) controls the cleaning energy (16), preferably automatically / self-regulating, on the basis of at least one property of the weld contact device (14), the electrolyte medium (18), and / or the workpiece material by controlling at least one component, in particular an inverter (30, 40), of the power supply device (12). [12] Method according to claim 11, characterized by, 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) controls the cleaning current power (P), in particular current and / or voltage level, to a substantially constant level as part of the adaptive control. [13] Method according to claim 11 or 12, characterized by , that the current control device (20) dynamically adjusts a DC amplitude profile or AC amplitude shape of the cleaning current (I) within the framework of adaptive control, in particular providing adaptive PWM modulation (pulse width modulation) of the cleaning current (I) and an adaptive PWM clock frequency. [14] Method according to any one of claims 11 to 13, characterized by, that the current control device (20) comprises a parameter memory, wherein at least one property of the weld contact device (14), the electrolyte medium (18), and / or the workpiece material is stored in the parameter memory and the cleaning current density (J) is dynamically controlled by the current control device (20) as a function of the parameters stored in the parameter memory, in particular the electrical resistance of a contact surface of the weld (11), the electrolyte medium (18), and / or the weld contact device (14), and / or the dimensioning of the contact surface. [15] Method according to any one of claims 11 to 14, characterized by, that electrolyte medium (18) is automatically conveyed from an electrolyte medium 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) relates the cleaning current power (P) to a quantity of the conveyed electrolyte medium (18) from the electrolyte medium reservoir, preferably wherein the weld seam contact device (14) comprises at least one position sensor that detects a position of the weld seam contact device (14) on the workpiece, and the position sensor is connected to the current control device (20), so that the current control device (20) performs an adaptive control of the cleaning current power (P) depending on the position of the weld seam contact device (14) on the workpiece and / or depending on the quantity of the conveyed electrolyte medium (18). [16] Method according to any one of claims 11 to 15, characterized by, that the power supply device (12) is designed as a switched-mode power supply, wherein the switched-mode power supply has a switching frequency of at least ≥ 100kHz, preferably wherein the current control device (20) and / or the power supply device (12) control output ripple in the cleaning voltage (U) of less than 2000mV peak to peak and maintain a control tolerance of the cleaning current (I) and the cleaning voltage (U) of less than ±1.5%. [17] Method according to any one of claims 11 to 16, characterized by, that the current control device (20) comprises an input device (50), in particular at least partially digital, for manually and / or automatically entering and / or storing specifications of weld contact devices (14), electrolyte media (18) and material materials usable with the weld cleaning device (10), as well as corresponding operating parameters of the power supply device (12) in the parameter memory, and provides an optimized presetting of the cleaning energy (16) on the basis of the specifications and operating parameters, in particular with regard to its cleaning current (I), cleaning voltage (U), cleaning power (P) and / or cleaning current density (J), preferably wherein the input device (50) 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 similar. [18] Method according to claim 17, characterized by that the specifications and operating parameters are manually entered into the parameter memory by a user and / or automatically retrieved or determined from a database stored internally within the device or in an external network, in particular the Internet, using an identification feature, in particular a QR code or RFID tag.

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