Double-type arc joining method

Abstract

It enables to provide a compound arc joining method that can form an overlapping joint pattern with a shift. 【Solution means】In each arc joining process, at least one joining parameter that affects the melting output (A) of the arc joining process varies according to a periodic variation function (V V ) including a variation frequency (f a , V b ). The melting output (A) depends on the wire feeding speed (v Da , v Db ) and the joining wire (5a, 5b). As a result of this variation, in each arc joining process, the preset time elapse of the wire feeding speed (v Da , v Db ) and the preset time elapse of the joining current (I Fa , I Fb ) are intended to vary periodically according to the variation function (V a , V b ).

Description

[Technical Field]

[0001] The present invention relates to a double arc joining method in which a double arc joining process is performed simultaneously to form a joint in a workpiece, During the execution of the complex arc joining method, in order to carry out each of the associated arc joining processes, an arc is discharged at least temporarily between the joining electrode and the workpiece, an electrical joining current flows at least temporarily through the joining electrode, and the joining wire moves into the arc at the wire feeding speed. This relates to a complex arc joining method in which each of the related arc joining processes is performed over a time interval predetermined from the joining parameters, and the time interval predetermined from the joining parameters includes at least one predetermined time interval of the interdependent joining current and at least one predetermined time interval of the wire feed rate. The present invention also relates to related joining equipment for carrying out such a double arc joining method. [Background technology]

[0002] Welding methods can be distinguished into those in which the electrode melts and those in which the electrode does not melt. An example of a welding method in which the electrode melts is metal arc welding (MSG), and an example of a welding method in which the electrode does not melt is tungsten inert gas welding (WIG). In welding methods in which the electrode does not melt, welding wire is usually used as filler material during welding, and this welding wire is supplied to the arc and melts within the arc. In welding methods in which the electrode melts, the welding wire also forms the electrode at the same time, but additional welding wire can also be supplied to the arc.

[0003] For example, metal-inert gas welding (MSG), including metal-inert gas welding (MIG) or metal-active gas welding (MAG), has been known as prior art for many years. In MSG welding, the molten electrode, which is made of a metal electrode material, is surrounded by a so-called shielding gas to protect the weld from the harmful effects of the surrounding air.

[0004] Generally, in arc welding, an arc is discharged between the electrode and the workpiece to be welded, using an electric welding voltage or the resulting electric welding current. In joining methods where the electrode melts, the arc melts the electrode and the surrounding area of ​​the workpiece, thereby forming a joint between the materials. Typically, the electrode material is the same as or similar to the workpiece material. The electrode is supplied to the welding site at a specific supply rate, which can be set to a constant rate, for example, by hand in manual welding or by adjustment with the welding machine, or it may depend on other parameters, such as the welding method performed, the welding speed at which the electrode moves relative to the base material, or the welding current.

[0005] In arc welding, various welding processes are well known. A welding process is fundamentally understood as the control of the time course of the welding voltage and / or welding current. Examples of well-known welding processes include pulse welding, interval welding, and spray arc welding. In pulse welding, a base voltage and a welding voltage higher than the base voltage overlap regularly, causing the base current and pulse current to alternate at a predetermined frequency and pulse duration. Pulse welding reduces the heat input to the workpiece, which is very advantageous in many applications. In interval welding, welding phases and pause phases alternate, with the welding cycle consisting of welding phases and pause phases. The transition between welding and pause phases is characterized by the detachment of molten droplets from the electrode. This often occurs first due to a short circuit caused by the electrode coming into contact with the molten pool. The welding current can have a desired time course during the welding phase or during the pause phase; for example, a pulsed welding current during the welding phase can have a desired time course. One example of such interval welding processes is the well-known cold metal transfer (CMT) welding method, in which the electrode wire feed is also dynamically changed during welding. The heat input to the workpiece can also be reduced using the interval welding process, which is very advantageous in many applications. Many other welding methods also exist. Typically, spray arc welding is performed with a constant welding current and without short-circuit interruption. The spray arc generates a high heat input to the workpiece, resulting in high melting power and deep penetration.

[0006] In addition to welding, arc brazing is also known as a joining method. Arc brazing differs from arc welding in that, unlike welding, the workpiece to be welded is not melted. In arc brazing, only the solder is melted. Arc brazing can be performed using the same equipment as arc welding. Arc brazing can also be distinguished into brazing methods in which the electrode used as solder melts and brazing methods in which the electrode does not melt. MSG brazing and WIG brazing are similarly known. Brazing methods, like arc welding, can be performed using interval brazing, pulse brazing, or spray arc brazing. The difference from welding is that, since the workpiece should not be melted in brazing, a lower brazing current and / or lower brazing voltage are used.

[0007] Therefore, in the following, arc joining or arc joining method will be referred to only in a more general sense, and in the sense of the present invention, this will be understood as arc welding or arc welding method, or arc brazing or arc brazing method. Similarly, joining current should be understood as the welding current or brazing current that flows through the electrodes when a joining voltage (welding voltage or brazing voltage) is applied to the electrodes.

[0008] The joining method is typically performed using a joining apparatus designed as a conventional welding apparatus. The joining apparatus comprises a power supply for generating a joining voltage and a joining current, and an electrode holder, such as a welding torch, on which the joining electrode is guided or held. The joining apparatus further includes a wire feeder for moving a joining wire, which simultaneously forms the joining electrode in a joining method in which the electrode is melted.

[0009] In particular, the present invention relates to an arc joining method in which an arc is discharged at least temporarily between an electrode and a workpiece to be joined, in which case the joining wire is melted.

[0010] To improve joining performance, a dual arc joining method is also known in which at least two arc joining processes are used simultaneously for joining. This includes, for example, a so-called tandem pulse joining method in which two pulsed arc joining processes are performed simultaneously. In this case, at least two joining electrodes in the form of welding wires or brazing wires are melted in the arc for joining. Generally, a separate joining apparatus is used for each pulsed arc joining process. In each joining apparatus, the pulsed arc joining method is realized by the respective control units of the joining apparatus appropriately controlling or adjusting the joining parameters, in particular the joining current, joining voltage, wire feed rate, and optionally the amount of shielding gas. It is also known that the two pulsed arc joining processes are synchronized over time to prevent the simultaneously proceeding pulsed arc joining processes from adversely affecting each other, which could degrade the joining quality. Examples of dual welding methods including synchronized welding processes can be found in Patent Document 1 (WO2020 / 8187A1) or Patent Document 2 (WO2022 / 129122A1).

[0011] In joining using arc welding or arc brazing, a specific joint pattern is often desired. Basically, it can be distinguished between continuous joint patterns and offset joint patterns. Continuous joint patterns result in a substantially flat surface at the joint. On the other hand, offset joint patterns exhibit a clearly discernible offset shape on the surface, formed along the joint in the form of crescent-shaped caterpillar-like sections. Offset joint patterns facilitate gas escape from the joint during joining, particularly hydrogen, oxygen, and other gases, which contributes to reducing pore formation within the joint. In welding, this also increases the mixing of different temperature zones within the molten pool, which increases the continuity of the welded joint and, consequently, improves weld quality. For example, offset joint patterns are desirable not only when welding aluminum but also when welding Cr-Ni steel.

[0012] In a single-arc joining method, which uses only one joining electrode and one arc joining process, a well-known staggered and overlapping joint can be achieved by periodically varying the molten output of the joining process at the same frequency. The periodic variation in molten output forms the staggered and overlapping joint. One major drawback in this case is that the periodic decrease in molten output results in lower joining speed and average molten output compared to joints with a continuous joint pattern. Therefore, staggered and overlapping joints can only be joined more slowly. Consequently, the economics of such joints are not always guaranteed.

[0013] In complex arc joining methods, which can improve joining performance, the melting power of the associated arc joining process cannot be simply varied periodically because it can negatively affect the associated arc joining process. This can lead to unstable arc joining processes, joining failures, wire material scattering on the base material, arc breakage, poor bonding, and strong arc deflection between the two. Therefore, until now, it has not been possible to form offset and overlapping joints using complex arc joining methods. [Prior art documents] [Patent Documents]

[0014] [Patent Document 1] International Publication No. 2020 / 8187 [Patent Document 2] International Publication No. 2022 / 129122 [Overview of the Initiative] [Problems that the invention aims to solve]

[0015] Therefore, the object of the present invention is to provide a double arc joining method and joining equipment for carrying out the double arc joining method, which enables the formation of offset and overlapping joint patterns. [Means for solving the problem]

[0016] In this invention, this problem is addressed. In each arc joining process, at least one joining parameter affecting the melting output of the arc joining process varies by a periodic variation function including a fluctuating frequency, and the melting output depends on the wire feed rate and the joining wire. As a result of this variation, the preset time elapsed of the wire feed rate and the preset time elapsed of the joining current in each arc joining process vary periodically according to the variation function. This is resolved by the following: In this case, the fluctuation frequency in each fluctuation function is the same. Therefore, the preset time elapsed of the wire feed speed and the preset time elapsed of the junction current change at the same frequency, i.e., the fluctuation frequency. This makes it possible to manufacture the desired offset and overlapping joint pattern using the double arc joining method without being affected by the adverse effects described above.

[0017] If each associated arc joining process is performed by a predetermined joining cycle that is periodically repeated at a cycle frequency, the minimum cycle frequency of the associated arc joining process is selected to be between 2 and 50 times the fluctuating frequency. Therefore, fluctuations in the joining parameters occur considerably later than the cycle frequency of the arc joining process, and this has little effect on the execution of the arc joining process.

[0018] In particular, in a complex arc joining method involving three or more arc joining processes running simultaneously, it is advantageous if the variation functions of these arc joining processes are synchronized with each other over time. Therefore, it is possible to avoid the arc joining processes negatively impacting each other due to variations in joining parameters. In two arc joining processes, a specific time reference for the variation function always exists, and synchronization prevents the time reference from changing during the execution of a complex arc joining method, which could negatively impact the joining processes.

[0019] The present invention will be described in more detail below with reference to Figures 1 to 8, which illustrate and schematicly illustrate advantageous embodiments of the present invention, and are not limiting. [Brief explanation of the drawing]

[0020] [Figure 1] Figure 1 shows the joining equipment for performing the double arc joining method. [Figure 2] Figure 2 shows a dual arc joining method using a pulsed arc joining process. [Figure 3] Figure 3 shows a dual arc joining method using an interval arc joining process. [Figure 4] Figure 4 shows a welded joint with a shifted and overlapping joint pattern. [Figure 5] Figure 5 shows an example of a variation function. [Figure 6] Figure 6 shows a complex arc joining method according to the present invention, in which an arc joining process is performed that includes a variation function containing fluctuating joining parameters. [Figure 7] Figure 7 shows an embodiment with a variation function that has shifted over time. [Figure 8] Figure 8 shows an implementation of the double arc joining method according to the present invention. [Modes for carrying out the invention]

[0021] Figure 1 schematically illustrates a workable joining apparatus 15 for a double arc joining process. The joining apparatus 15 includes two separate joining devices 1a, 1b, each equipped with power supplies 2a, 2b, wire feeding units 3a, 3b, and joining electrode holders 4a, 4b (e.g., each welding torch). Power supplies 2a, 2b supply the required joining voltage and joining current, respectively, to be applied to each joining wire 5a, 5b (as the joining electrodes 16a, 16b that melt in the joining method). For this purpose, the joining electrode holders 4a, 4b may be provided with contact sleeves to which the joining voltage is applied, for example, via electrical supply lines 6a, 6b between the power supplies 2a, 2b and the contact sleeves, which are electrically contacted by the joining wires 5a, 5b. However, joining electrode holders 4a, 4b with non-melting joining electrodes 16a, 16b (for example, for performing the WIG method) may also be used, to which the joining voltage is applied via supply lines 6a, 6b. In this case, the wire feeding units 3a and 3b supply the joining wires 5a and 5b to the arc 17 between the non-melting electrode and the workpiece 10.

[0022] Therefore, during the junction, at least temporarily a specific junction current I Fa , I Fb However, current flows through the respective bonding electrodes 16a and 16b, and in order to close the current circuit, an earth line 9a is provided between the power supplies 2a and 2b and the workpiece 10 in a known manner (only shown for bonding device 1a in Figure 1).

[0023] In each joining device 1a, 1b, the joining wires 5a, 5b are fed at a specific wire feeding speed v by the wire feeding units 3a, 3b, respectively. a , v b The wires are transported by this device. The wire feeding units 3a and 3b can be integrated with the bonding devices 1a and 1b, respectively, but they may be separate units or located in another location, for example, in or on top of the bonding electrode holders 4a and 4b.

[0024] The joining wires 5a, 5b and electrical supply lines 6a, 6b of the joining devices 1a, 1b, and optionally further lines between the power supplies 2a, 2b and the joining electrode holders 4a, 4b (e.g., control lines, shielding gas lines, or coolant lines) can also be routed within a common cable assembly. The cable assembly can be connected to the joining electrode holders 4a, 4b and power supplies 2a, 2b, preferably detachably, via appropriate couplings.

[0025] Furthermore, the bonding devices 1a and 1b are equipped with control units 7a and 7b for controlling and monitoring the bonding process to be performed. For this purpose, a measurement unit (not shown) may be provided to grasp bonding parameters (such as bonding voltage or bonding current) and provide them to the control units 7a and 7b. To perform the desired bonding process, necessary bonding parameters such as cycle frequency, wire feeding speed, and bonding current values ​​are either preset or adjustable in the control units 7a and 7b. Input / output units 8a and 8b may be provided to reliably input or display bonding parameters, or to display the bonding status.

[0026] Typically, the control units 7a and 7b in each bonding device 1a and 1b also control the time course of the bonding current for performing the arc bonding process by their respective bonding devices 1a and 1b. The time course of the bonding current is adjusted by adjusting the bonding voltage. However, this can also be done in reverse: the time course of the bonding voltage can be preset, and the bonding current can be adjusted. For this adjustment, the actual value of the value to be adjusted, such as the bonding voltage or bonding current, is usually also required for each time step of adjustment (usually in the range of microseconds to milliseconds).

[0027] The control units 7a and 7b are typically integrated with the bonding devices 1a and 1b and are designed as microprocessor-based hardware running on software that enables the necessary functions of the bonding devices 1a and 1b, such as regulating the bonding current or bonding voltage. The control units 7a and 7b can also be designed as external devices to the bonding devices 1a and 1b. Similarly, the control units 7a and 7b can also be implemented in other ways, for example, as an integrated circuit (such as an application-specific integrated circuit (ASIC) or a field-programmable gate array (FPGA)), or in the form of an electrical or electronic circuit.

[0028] Such joining devices 15 and 1a, 1b are, of course, well known and will not be described in detail here. For example, conventional welding equipment capable of performing both welding and brazing processes can be used as joining devices 1a, 1b. In a double arc joining method with two or more joining processes, corresponding double joining devices 1a, 1b are naturally provided. The double joining devices 1a, 1b for a double arc joining process can, if necessary, be housed in a common housing together with associated wire feeding units 3a, 3b.

[0029] To implement a double arc joining method, the two joining electrode holders 4a and 4b in the illustrated embodiment are positioned relative to each other so as to function within the same joint 11 on the workpiece 10. This arrangement of joining electrode holders 4a and 4b may be fixed to each other, for example, the two joining electrode holders 4a and 4b are positioned on the welding robot 13 in a fixed relative position to each other. Furthermore, the welding robot 13 guides the two joining electrode holders 4a and 4b (see Figure 1). However, the two joining electrode holders 4a and 4b can also be guided manually. However, the relative arrangement of joining electrode holders 4a and 4b may be variable, for example, one joining electrode holder 4a and one 4b each being guided by the welding robot 13. Also, with respect to the present invention, it is not important whether the joining electrode holders 4a and 4b are positioned one behind the other, adjacent to each other, or otherwise offset from each other with respect to the joining direction.

[0030] Arc joining methods perform an arc joining process. This arc joining process is understood as the time course of the joining current and / or joining voltage, as well as the time course of the wire feed rate. These time courses are preset, for example, in the form of joining programs in joining devices 1a and 1b, or by adjustments in joining devices 1a and 1b, in order to perform each arc joining process.

[0031] Figure 2 shows a possible embodiment of a dual arc joining method using arc joining processes, in which each pulsed arc joining process is performed using joining devices 1a and 1b. The pulsed arc joining process involves a junction current I flowing through the joining electrodes 16a and 16b over time t. Fa , I Fb This will be explained based on the process described above. During the execution of the pulsed arc bonding process using bonding devices 1a and 1b, an arc 17 is naturally discharged between the bonding electrodes 16a and 16b and the workpiece 10, at least temporarily.

[0032] Pulse arc junction process junction current I Fa , I FbOver time, the base current I FG and the increasing pulse current I FI are provided with bonding cycles FZa, FZb that periodically and alternately appear at a preset cycle frequency f Da , f Db . The cycle frequencies f Da , f Db are naturally calculated as the reciprocals of the cycle durations t Da , t Db of the bonding cycles FZa, FZb, which consist of a base current stage having the base current I FG and a pulse current stage having the pulse current I FI . Advantageously, during the pulse current stage, it is desirable for the molten droplets of the bonding wires 5a, 5b to melt into the bonding seam 11. During bonding, at least one of the pulse frequencies f Da , f Db and / or the value of the base current I FG or the value of the pulse current I FI may change. The cycle frequency f D of the pulse arc bonding process is typically in the range of 5 Hz to 1 kHz.

[0033] Of course, the duration of the pulse current stage of the bonding cycle FZ in the pulse arc bonding process may not be the same (as shown in Figure 2), or the values of the base current I FG or the pulse current I FI may not be the same. Similarly, it is conceivable that the cycle frequencies f Da , f Db are different in two pulse arc bonding processes.

[0034] The elapsed time of the bonding currents I Fa , I Fb is naturally idealized and described in a simplified manner in Figure 2. In reality, of course, a specific current ramp is formed at the edge. Similarly, to promote the melting of the droplets, from the pulse current I FI to the base current I FGWhen transitioning to this, the junction current I is gradually changed or through a different current path. Fa , I Fb It is often intended to reduce the process. To improve process stability, short intermediate current pulses are often introduced in the base current stage. However, this affects the period duration t of the junction cycle FZ. D and the resulting cycle frequency f D It does not change.

[0035] The wire feeding speed v of the pulsed arc joining process for the double arc joining method shown in Figure 2. Da , v Db Although not shown in Figure 2, this can be pre-set to be adjusted, for example, by the joining devices 1a and 1b. Wire feeding speed v Da , v Db is the junction current I Fa , I Fb Depending on the situation, this can also be pre-configured when performing a pulsed arc bonding process.

[0036] Figure 3 shows a dual arc joining method in which an interval arc joining process is performed using joining devices 1a and 1b. In the interval arc joining process, joining stages FPa and FPb and pause stages PPa and PPb appear periodically and alternately, and the joining cycles FZa and FZb consist of joining stages FPa and FPb and pause stages PPa and PPb, respectively. This is an example of a dual arc joining method with two interval arc joining processes in Figure 3, and the joining current I Fa , I Fb This is described based on the time progression. In the illustrated embodiment, a pulsed junction current I occurs at junction stages FPa and FPb. Fa , I Fb Although a feature is provided, it is not necessarily required. In order to reduce the heat input to the workpiece 10, in the pause stages PPa and PPb, the junction current I is set relative to the pulse current in the junction stages FPa and FPb. Fa , I FbThe current level decreases, but the bonding continues. However, in the pause stages PPa and PPb, a temporary, intentional short circuit may occur between the bonding electrodes 16a and 16b and the workpiece 10. Similarly, in bonding cycles FZa and FZb, an interval arc bonding process is also conceivable in which the arc 17 is extinguished for a certain period of time, or multiple times.

[0037] Junction current I Fa , I Fb The time progression is, of course, idealized and simplified in Figure 3. In reality, of course, a specific current ramp is formed at the edge. Junction current I in pause stages PPa, PPb and / or junction stages FPa, FPb Fa , I Fb The passage of time can also be described in a different way than in Figure 3.

[0038] Figure 3 also shows the period duration t of the junction cycles FZa and FZb. Da , t Db This shows that, from this period duration, the cycle frequencies f of the junction cycles FZa and FZb can be determined. Da ,f Db The cycle frequency f of the interval arc joining process is calculated. D These frequencies typically fall within the range of 0.5 Hz to 100 Hz.

[0039] Figure 3 shows the joining cycles FZa and FZb, as well as the wire feeding speed v. Da , v Db It is also described. In the illustrated embodiment, it can be seen that wire feeding stops at pause stages PPa and PPb, and that wire feeding may even temporarily reverse. Wire feeding speed v Da , v Db This passage of time is merely an example.

[0040] In addition to the arc joining process shown as an example in Figures 2 and 3, the joining current I F , junction voltage, or wire feeding speed v DThere may be many other arc welding processes that include a periodically repeating welding cycle FZ based on a predetermined time interval. An example of an arc welding process that includes a periodically repeating welding cycle FZ is the cold metal transfer (CMT) welding process. In this welding process, the welding wires (welding wires 5a, 5b) move toward the workpiece 10 until a short circuit is formed. Then the welding current (welding current I) F The current is interrupted, and the welding wire is returned in the opposite direction. Due to the movement of the wire, the weld bead formed during the short circuit separates from the wire particularly easily. Little to no spatter occurs. This process is repeated periodically. Welding can also be performed with a pulsed welding current during the welding phase. Another example is one where there is no joining cycle FZ, but the joining current I F and wire feeding speed v D This is a spray arc bonding process with a constant flux. In particular, high melting power can be achieved using the spray arc bonding process. However, in the present invention, an arc bonding process having a periodically repeating bonding cycle FZ is preferably used.

[0041] In a complex arc joining process, the individual arc joining processes are typically synchronized with each other over time, i.e., they have a specific temporal relationship. For example, joining cycles FZa and FZb have a defined temporal relationship with respect to each other. This temporal relationship is determined by a phase shift t. p This is shown as (as in Figures 2 and 3), and is typically between 0° and 180°. 0° typically indicates that two current edges start simultaneously, while 180° indicates that two current edges start with the maximum distance between them.

[0042] The method for synchronizing the arc joining process is described in the aforementioned literature. To synchronize, a communication connection 14 (wired or wireless) may be provided between joining devices 1a and 1b, and synchronization information SI is exchanged via this communication connection as needed.

[0043] Figure 4 shows an example of a welded seam on a welded workpiece 10, illustrating a seam pattern where the joint seams 11 are offset and overlapping. A crescent-shaped caterpillar-like portion 12 is visible along the joint seams 11, forming this offset and overlapping seam pattern. To manufacture such an offset and overlapping seam pattern using a double arc welding method, the present invention follows the procedure described below.

[0044] In order to manufacture a joint 11 in the workpiece 10, a double joining method involves performing a double (at least two) arc joining process simultaneously. In each arc joining process, at least temporarily, an electrical joining voltage is applied to the joining electrodes 16a and 16b, thereby introducing a corresponding joining current I through the joining electrodes 16a and 16b. Fa , I Fb During the execution of the complex bonding process, in each of the related arc bonding processes, an arc 17 is discharged at least temporarily between the bonding electrodes 16a, 16b and the workpiece 10, and an electrical bonding current I occurs. Fa , I Fb The current flows at least temporarily through the respective bonding electrodes 16a and 16b. In this case, the bonding wires 5a and 5b are fed at a wire feeding speed v Da , v Db Then move in the direction of arc 17. Each related arc junction process involves the junction current I Fa , I Fb and wire feeding speed v Da , v Db It is executed over a predetermined time interval. In each related arc joining process, at least one joining parameter that affects the melting output A of the arc joining process is set to a fluctuating frequency f V A periodic variation function V that includes a , V b The melting output A varies depending on the wire feeding speed v Da , v Db and depends on the joining wires 5a and 5b, and as a result, in each arc joining process, the wire feeding speed v Da , v Db The preset time elapsed and junction current IFa , I Fb The preset time elapsed for a , V b varies periodically according to V Fa , I Fb and the wire feed speed v Da , v Db . Thus, at least partially, joining is performed with joining parameters different from those intended by the arc joining process.

[0045] According to the present invention, the melting output of the arc joining process related to the multi - arc joining method varies periodically at a preset variable frequency f V . Preferably, the wire feed speed v Da , v Db and the joining current I Fa , I Fb decrease periodically from the preset wire feed speed v Da , v Db and the joining current I Fa , I Fb and then increase again to the preset wire feed speed v Da , v Db and the joining current I Fa , I Fb . Thus, the wire feed speed v Da , v Db and the joining current I Fa , I Fb preferably vary between a preset value and a lower value for each executed arc joining process. Instead of decreasing, it is basically possible to increase by the variation. Similarly, by the variation, both decrease and increase are possible.

[0046] However, the variation does not occur abruptly between these values, but rather occurs by an elapsed process according to a preset periodic variation function V(f V ).

[0047] As an example, the periodic variation function V(fV ) is a sine function or cosine function, a trapezoidal function or a trigonometric function, as illustrated in Figure 5, or a period duration t V V(f) is another periodic function that includes the amplitude change over time. V ) period duration t V is the fluctuating frequency f V It brings about.

[0048] Periodic variation function V(f V The amplitude of ) is preferably the upper fluctuation value V o and the lower fluctuation value V u It fluctuates between these two extremes. How the fluctuation occurs is irrelevant.

[0049] For example, the variation function V can be normalized to 1. In this case, a value of 1 for the variation function V corresponds to the wire feed speed v. Da , v Db or junction current I Fa , I Fb This corresponds to a superposition that yields a pre-set value. The lower fluctuation value V u The upper variation value V is greater than zero, preferably in the range of 0.1 to 1. o V is preferably 1, but can be selected within the range of 1 to 10. However, the variation function V can also be specified as a percentage, in which case 100% is the wire feeding speed v Da , v Db or junction current I Fa , I Fb This corresponds to a superposition that yields a predetermined value. Similarly, the variation function V is the wire feed speed v Da , v Db or junction current I Fa , I Fb It can directly correspond to the value of [the variable].

[0050] Frequency of variation f V In the case of a complex arc joining process that includes an arc joining process with a joining cycle FZ, the minimum cycle frequency f of the joining cycle of the arc joining process in the complex arc joining method is D However, the fluctuating frequency f VIt is selected to be at least twice as large as the minimum cycle frequency f of the arc joining process in a double arc joining method. D is the fluctuating frequency f V It is 2 to 50 times. For example, in the case of a double arc joining method using an arc joining process that does not involve joining cycles, such as the spray arc process, the fluctuating frequency f V However, it is preferably selected between 0.1 Hz and 25 Hz. Basically, the fluctuating frequency f V The higher the value selected, the finer the overlapping and offset of the seams 11, and vice versa.

[0051] For each arc joining process associated with a complex arc joining process, such a variation function V(fV) exists, but all variation functions V a (f V ), V b (f V ) have the same fluctuation frequency f V It has the following variation function V a (f V ), V b (f V ) is the fluctuating frequency f V As long as the values ​​are the same, they do not necessarily have to be the same. Preferably, the variation function V of the associated arc joining process. a (f V ), V b (f V These are synchronized with each other over time, that is, they have a predetermined temporal relationship with each other. The periodic variation function V of the related arc joining process. a (f V ), V b (f V ) Phase shift t pV (See, for example, Figure 6) is preferably in the range of 0° to a maximum of 180°, preferably a maximum of 30°. The variation function V a (f V ), V b (f V The synchronization of the variation function V a (f V ), V b (f VThe relationship between ) over time does not change and is guaranteed to remain constant even during the execution of the double arc joining method, thereby obtaining better joining results.

[0052] The melting output A of the arc joining process using joining wires 5a and 5b is given by the wire feeding speed v Da , v Db and depending on the joining wires 5a and 5b, for example,

number

[0053] From this equation, the melting power A of the arc joining process is given by the wire feeding speed v Da , v Db It can be seen that it may be affected by the wire feed rate v. Da , v Db and junction current I Fa , I Fb Since the fusion output A and junction current I are interdependent, and this dependency is known or predetermined, the fusion output A is equal to the junction current I. Fa , I Fb It can also be affected by this. This is because the junction current I is affected by this dependency. Fa , I Fb The fluctuation of the wire supply speed v Da , v Db This is because it causes fluctuations in the junction current I. Fa , I Fb The wire feeding speed v Da , v Db As increases, the junction current I increases at a known rate. Fa , I FbSince this is naturally determined by the bonding voltage applied to the bonding wires 5a and 5b, the melting output A may also be affected by the bonding voltage.

[0054] Therefore, the junction current I Fa , I Fb , wire feeding speed v Da , v Db The bonding voltage and other bonding parameters are bonding parameters that can affect the molten output A of the arc bonding process.

[0055] In the arc junction process, the junction current I Fa , I Fb and wire feeding speed v Da , v Db These are typically connected to each other via a predetermined characteristic curve that defines the dependency. Therefore, the junction current I Fa , I Fb The change is usually due to the wire feeding speed v Da , v Db This leads to a change, and vice versa.

[0056] This is illustrated in Figure 6 using an example of a complex arc joining method involving two pulsed arc joining processes (as described in Figure 2).

[0057] The upper diagram in Figure 6 shows the junction current I of two pulsed arc junction processes. Fa , I Fb The time course is shown, and the central figure shows the wire feeding speed v of the two pulse arc joining processes. Da , v Db The figure below shows the time course of the variation function V used. a (f V ), V b (f V This shows the pulse frequency f of the pulsed arc joining process. Da ,f Db However, the variation function V a (f V ), V b (f V ) fluctuation frequency f VThis is approximately 30 times. In this example, the variation function V a (f V ), V b (f V ) is normalized to 1, is trapezoidal, and has a variation function V a (f V ), V b (f V The amplitude of the pulse changes between 0.25 and 1. The wire feeding speed v of the two pulse junction processes. Da , v Db These are the respective variation functions V a (f V ), V b (f V ) is superimposed, and as a result, the wire feeding speed v Da , v Db V is the variation function a (f V ), V b (f V The fluctuation frequency f depends on the amplitude of ) V = 1 / t V So, v Da , v Db and 0.25·v Da , 0.25·v Db It fluctuates between [value]. Therefore, in this embodiment, the wire feeding speed v Da , v Db The junction current I decreases periodically from a preset value to one-quarter of the preset value. Fa , I Fb The wire feeding speed v Da , v Db Since it depends on the junction current I Fa , I Fb This is also affected, and in this embodiment, it decreases periodically according to a preset dependence between the wire feed rate and the junction current. In this way, the molten output A of the pulsed arc junction process has a fluctuating frequency f V It fluctuates periodically, which results in the desired patterned seam pattern.

[0058] Alternatively, the variation function V a (fV), V b (fV) is the wire feeding speed v Da , vDb and / or junction current I Fa , I Fb For example, a wire feed speed v between 6 m / min and 12 m / min is a value related to this. Da , v Db It can also be specified directly as the value of v Da , v Db and / or junction current I Fa , I Fb The pre-set value of the variation function V a (f V ), V b (f V This means that it will be replaced by the value of ).

[0059] In Figure 6, in this embodiment, the cycle frequency f of the arc joining process is Da ,f Db Wire feeding speed v Da , v Db It can be seen that it depends on the cycle frequency f of the arc joining process. Da ,f Db Also, wire feeding speed v Da , v Db It decreases as the rate of change decreases. In this case, the cycle frequency f of the arc joining process decreases. Da ,f Db The variation function V a (f V ), V b (f V ) fluctuation frequency f V It remains significantly larger than that.

[0060] In this embodiment shown in Figure 6, the variation function V a (f V ), V b (f V ) is a phase shift t pV At 0°, they are synchronized with each other over time. However, as shown in Figure 7, a phase shift of >0° (but up to 180°) may also be intended. For simplicity, Figure 7 shows the variation function V. a (f V ), V b (fV ) and wire feeding speed v Da , v Db Only this information is listed.

[0061] Variation function V of the arc joining process related to the complex arc joining method a (f V ), V b (f V The temporal synchronization of ) can be performed in the same way as the synchronization of the joining process itself. The joining devices 1a and 1b use the variation function V a (f V ), V b (f V To synchronize the devices, synchronization information SV is exchanged once or repeatedly. For this purpose, the communication connection 14 may be provided between the associated bonding devices 1a and 1b, preferably between the control units 7a and 7b of the bonding devices 1a and 1b, as shown in Figure 1. The communication connection 14 may be wired or wireless.

[0062] In its simplest form, the communication connection 14 is an electrical line through which current pulses and / or voltage pulses are transmitted as synchronization information SV from transmitting connection devices 1a, 1b to receiving connection devices 1a, 1b. However, the synchronization information SV can also be a specific signal pattern or signal frequency, or other information that can be transmitted through the communication connection 14.

[0063] The communication connection 14 can also be designed as a data bus. In this case, the data communication protocol is executed on the data bus, and the synchronization information SV is transmitted from the transmitting junction devices 1a, 1b to the receiving junction devices 1a, 1b, for example, in bus messages of the data communication protocol, according to the data communication protocol. It is possible to pre-configure which junction devices 1a, 1b are the transmitting and which are the receiving. However, in the case of more than two junction devices 1a, 1b, usually only one is the transmitting junction device 1a, 1b, and the others are receiving devices.

[0064] In a dual-mode arc joining method using synchronous arc joining processes, the variation function V of the related arc joining processes is used.a (f V ), V b (f V ) also synchronizes further. However, arbitrary synchronization of the arc joining process and the variation function V a (f V ), V b (f V Synchronization of ) means that they can be performed independently of each other. However, the variation function V a (f V ), V b (f V ) can also be synchronized over time with the arc bonding process.

[0065] wire feeding speed v in arc bonding process Da , v Db , or junction current I Fa , I Fb , or another bonding parameter (e.g., cycle frequency f) that affects the bonding voltage or melting output A (even indirectly). Da ,f Db The variation of ) is the variation function V a (f V ), V b (f V How this is achieved is not important to the present invention. There are other possible embodiments for which the joining parameters affecting the melt output A are varied.

[0066] Joining parameters that (even indirectly) affect the melting output A include, in particular, the wire feeding speed v. Da , v Db , junction current I Fa , I Fb , junction voltage, or cycle frequency f Da ,f Db That is the case.

[0067] For example, the affected junction parameters can be analyzed using the associated variation function V for each time point under consideration. a (f V ), V b (f V It can be multiplied by ). This is especially true for the variation function V normalized to 1. a (fV ), V b (f V ) is suitable for the case of, or the variation function V expressed as a percentage a (f V ), V b (f V This is suitable for the case of ). In this way, the required values ​​for the joining parameters can be obtained at any time.

[0068] However, the values ​​of the joining parameters necessary to carry out the arc joining process can be stored in a table format in the joining devices 1a and 1b for the double arc joining method. This is the variation function V a (f V ), V b (f V This is particularly suitable when you want to specify values ​​for the joining parameters in advance.

[0069] Such tables can be configured for pulsed arc joining processes as shown in Figure 2, as listed in Table 1 below.

[0070] [Table 1]

[0071] Next, the fluctuating frequency f V The number of rows in the table represents the joining parameter (in this example, the wire feeding speed v). D , cycle frequency f D , junction current I F (Here, the base current I FG and pulse current I FI (Form)), pulse duration T of the current pulse P New values ​​for these, and potentially other joining parameters, are taken from the table to determine the time intervals used to control the arc joining process. If necessary, the values ​​in the table can be interpolated or extrapolated.

[0072] Therefore, it is possible to store different tables for different arc joining processes. When performing an arc joining process, you only need to select the correct table.

[0073] The values ​​in the table can be predetermined, for example, by inspection of a double arc joining method using joining devices 1a and 1b. This can be done, for example, by the manufacturer of joining devices 1a and 1b and stored in the joining devices 1a and 1b.

[0074] However, such tables can also depend on other parameters, such as the bonding speed, which indicates how quickly the electrode holders 4a and 4b are moved. The bonding speed, of course, can affect the bonding parameters, and consequently, there may be different tables containing the bonding parameters for different bonding speeds. Depending on the current bonding speed, the required bonding parameters can be obtained from the assigned table.

[0075] The procedure according to the present invention will again be described with reference to Figure 8, using an example of a joining apparatus 15 for performing a double arc joining process. In the illustrated embodiment, there are two arc joining processes, with joining devices 1a and 1b performing the arc joining processes, respectively. Joining devices 1a and 1b are described only to the extent necessary. Each arc joining process is controlled by associated control units 7a and 7b by a preset time elapsed of joining parameters FPa and FPb. In this embodiment, the time elapsed of joining parameters FPa and FPb is read from storage devices 18a and 18b of the associated joining devices 1a and 1b, but this time elapsed can also be obtained from other sources. The joining parameters FPa and FPb are at least the joining current I Fa , I Fb And, wire feeding speed v Da , v Db This includes the following. These junction parameters FPa and FPb depend on each other in a predetermined way, and as a result, changing one of these junction parameters FPa and FPb also changes the other junction parameter FPa and FPb. Each arc junction process has a periodic variation function Va (f V ), V b (f V ) are also pre-set and, for example, stored in the associated storage devices 18a and 18b, as shown in the embodiment of Figure 8. In each arc joining process, at least one of the joining parameters FPa and FPb associated with each arc joining process is associated with an associated periodic variation function V including the variation frequency fV. a (f V ), V b (f V ) fluctuates, and these joining parameters FPa and FPb are affected by the (wire feed rate v) of the arc joining process. Da , v Db This affects the melting output A (which depends on the joining wires 5a and 5b). This variation can be controlled in the respective control units 7a and 7b. As a result of this variation, the wire feeding speed v in each arc joining process is affected. Da , v Db The predetermined time elapsed is affected, and consequently, the junction current I is affected by the predetermined dependency. Fa , I Fb The predetermined time elapsed is also affected. This effect is the variation function V a (f V ), V b (f V It occurs periodically depending on the wire feeding speed v. The arc joining process is performed by the wire feeding speed v. Da , v Db and junction current I Fa , I Fb This is performed using these fluctuating time intervals. That is, for example, the junction current I Fa , I Fb Power supplies 2a and 2b are controlled to generate different connection parameters FPa and FPb over time as needed, and the wire feeding speed v Da , v Db To generate the elapsed time, wire feeding units 3a and 3b are controlled.

[0076] Variation function V a (f V ), V b (f VDue to the periodic fluctuations caused by ), the junction current I Fa , I Fb And, wire feeding speed v Da , v Db The actual time elapsed, which is predetermined by the arc joining process being executed, changes accordingly. Therefore, the joining is performed, at least partially, by joining parameters FPa and FPb that are different from those intended by the arc joining process.

[0077] In Figure 8, the variation function V a (f V ), V b (f V It is also clear that these can synchronize with each other over time. For this reason, control units 7a and 7b can also exchange synchronization information SV, as described above.

Claims

1. A double arc joining method in which a double arc joining process is performed simultaneously to form a joint (11) in a workpiece (10), During the execution of the complex arc joining method, in order to carry out each of the associated arc joining processes, at least a temporary arc (17) is discharged between the joining electrodes (16a, 16b) and the workpiece (10), and an electrical joining current (I Ｆａ , I Ｆｂ ) flows at least temporarily through the joint electrodes (16a, 16b), and the wire feeding speed (v Ｄａ , v Ｄｂ ) The joining wires (5a, 5b) move to the arc (17), Each of the related arc joining processes is performed over a predetermined time interval based on the joining parameters (FPa, FPb), and the time interval of the joining parameters (FPa, FPb) is determined by the interdependent joining current (I Ｆａ , I Ｆｂ ) at least one preset time interval and wire feeding speed (v Ｄａ , v Ｄｂ ) including at least one predetermined time interval, In the said double-arc joining method, In each arc bonding process, at least one bonding parameter (FPa, FPb) that affects the melting output A of the arc bonding process, which depends on the wire feeding speed (v Ｄａ , v Ｄｂ ), and the bonding wires (5a, 5b) is varied by a periodic variation function (V Ｖ ) that includes a variable frequency (f ａ , V ｂ ), Each variation function (V ａ , V ｂ ) fluctuation frequency (f Ｖ ) are the same, and as a result of this variation, in each arc joining process, the wire feeding speed (v Ｄａ , v Ｄｂ ) The pre-set time elapsed and junction current (I Ｆａ , I Ｆｂ The predetermined time elapsed of ) is determined by the variation function (V ａ , V ｂ ) which fluctuates periodically in accordance with A double-arc joining method characterized by the following:

2. Each related arc joining process has a cycle frequency (f Ｄａ , f Ｄｂ The process is performed by a preset bonding cycle (FZa, FZb) that is periodically repeated at ) and is performed at the minimum cycle frequency (f) of the arc bonding process. Ｄａ , f Ｄｂ ) is the fluctuating frequency (f Ｖ ) is 2 to 50 times, The double arc joining method according to feature 1.

3. The variation function (V) of the arc joining process. ａ , V ｂ The double arc joining method according to claim 1 or 2, characterized in that the two elements are synchronized with each other over time.

4. Variation function (V ａ , V ｂ ) is a phase shift (t) between 0° and 180°. ｐＶ The double arc joining method according to claim 3, characterized in that they are synchronized with each other.

5. A double arc joining method according to any one of claims 1 to 4, characterized in that the double arc joining processes are synchronized with each other over time.

6. The complex arc joining process involves a phase shift (t) between 0° and 180°. ｐ The double arc joining method according to claim 5, characterized in that it is synchronized by ).

7. A joining facility that performs a double arc joining method using a double joining device (1a, 1b), When using the joining equipment (15), the joining devices (1a, 1b) are adjusted to perform one arc joining process each in order to form a joint (11) in the workpiece (10). Each bonding device (1a, 1b) comprises a power supply (2a, 2b), a wire feeding unit (3a, 3b), a control unit (7a, 7b), and bonding electrodes (16a, 16b). During the execution of a dual arc joining method, in order to perform one of the related arc joining processes, each joining device (1a, 1b) executes each related arc joining process with predetermined time profiles and joining parameters (FPa, FPb). The junction current (I) flows through the junction electrodes (16a, 16b) due to the power supply (2a, 2b). Ｆａ , I Ｆｂ ) occurs, and as a result, the wire feeding units (3a, 3b) feed the connecting wires (5a, 5b) at a wire feeding speed (v Ｄａ , v Ｄｂ The arc (17) is moved, and the control units (7a, 7b) cause the power supply (2a, 2b) and the feed unit (3a, 3b) to act so that the arc (17) discharges at least temporarily between the bonding electrode (16a, 16b) and the workpiece (10). It has been adjusted to that extent. The time course of the junction parameters (FPa, FPb) is determined by the junction current (I Ｆａ , I Ｆｂ ) at least one preset time interval and wire feeding speed (v Ｄａ , v Ｄｂ ) including the pre-set time elapsed, In the said joining equipment, To carry out the related arc joining process, each joining device (1a, 1b) uses the control unit (7a, 7b) to control the wire feeding speed (v Ｄａ , v Ｄｂ In the relevant arc joining process, at least one joining parameter (FPa, FPb) that affects the melting output A of the arc joining process, which depends on the joining wires (5a, 5b), is a variable frequency (f Ｖ A periodic variation function (V) that includes ) ａ , V ｂ It is adjusted to fluctuate depending on the following: Wire feeding speed in each arc joining process (v Ｄａ , v Ｄｂ The pre-set time elapsed of ) and the junction current (I Ｆａ , I Ｆｂ The pre-set time progression of ) is determined by the variation function (V ａ , V ｂ Because it fluctuates periodically depending on ), the fluctuation frequency (f Ｖ ) is each variation function (V ａ , V ｂ ) are the same, A joining device characterized by the following features.

8. To carry out the associated arc joining process, each joining apparatus (1a, 1b) uses the control unit (7a, 7b) to set the cycle frequency (f Ｄａ , f Ｄｂ The system is configured to perform the associated arc joining process in a preset joining cycle (FZa, FZb) that is periodically repeated. The minimum cycle frequency (f) of the arc joining process related to the double arc joining method. Ｄａ , f Ｄｂ ) is the fluctuating frequency (f Ｖ ) is 2 to 50 times, The joining equipment according to feature 7.

9. In order to implement a double arc joining method, the control units (7a, 7b) of the associated joining apparatus (1a, 1b) control the variation function (V) of the arc joining process. ａ , V ｂ The joining equipment according to claim 7 or 8, characterized in that the elements are adjusted to synchronize with each other over time.

10. The control units (7a, 7b) of the bonding apparatus (1a, 1b) are connected to each other via a communication connection (14), and the control units (7a, 7b) control the variation function (V ａ , V ｂ The joining equipment according to claim 9, characterized in that it is adjusted to transmit synchronization information (SV) via the communication connection (14) in order to synchronize the following.

11. The joining apparatus according to any one of claims 7 to 10, characterized in that, in order to carry out a double arc joining process, the control units (7a, 7b) of the associated joining apparatus (1a, 1b) are adjusted to synchronize the double arc joining processes with each other over time.

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