Method for the demand-based cooling of a joining tool unit of a joining system and a joining system for carrying out such a method

Abstract

The invention relates to a method for the demand-based cooling of a joining tool unit of a joining system and / or for the extraction of dust and / or particles and / or flakes from the joining system, with a provision step in which the joining system (3), comprising a joining tool unit (1) and a control unit (43) and a cooling device (21), is provided, a first joining process (I), wherein in a first joining step (111) of the first joining process (I) a first joining part and a second joining part are joined by means of the joining tool unit (1), a temperature reading step in which an actual temperature value of the joining tool unit (1) at the end of the first joining step (111) is read in by the control unit (43), and a cooling step in which the control unit (43) uses the actual temperature value of the joining tool unit (1) at the end of the first joining step (111),whether cooling of the joining tool unit (1) is required until the start of a second joining step (211) of a second joining process (II) or not, and, if cooling of the joining tool unit (1) is required, the control unit (43) activates and / or deactivates the cooling device (21) until the start of the second joining step (211) as required and / or in an energy-efficient manner.

Description

Technical area

[0001] The present invention relates to a method for the demand-based cooling of a joining tool unit of a joining system and to a joining system for carrying out such a method. State of the art

[0002] It is generally known to join parts in a joining system and in a single joining step, for example, using ultrasonic welding to form a component assembly in series production. For example, the component assembly can be a connecting cable for a traction battery of a fully electric vehicle, which has a connecting terminal and a stranded wire.

[0003] To join the parts to be joined, an operator of the joining system first inserts the connection terminal into a joining chamber of the joining system and clamps it to the joining system using clamping devices. The operator then inserts the stranded wire into the joining chamber and places it onto the connection terminal, whereupon it is secured there. The operator then closes a protective door of the joining system. A protective door switch of the joining system, actuated by the protective door, transmits a closing signal to a control unit of the joining system. Upon receipt of the closing signal, the control unit outputs a joining signal to a joining control unit of the joining system, whereupon a joining tool unit of the joining system is controlled such that the stranded wire is joined, preferably welded, to the connection terminal. During the joining step, the joining tool unit, in particular, heats up.In order to prevent overheating of the joining tool unit even after several joining processes, a cooling device of the joining system is in continuous operation to cool the joining tool unit.

[0004] The fact that the cooling system is continuously in operation results in several disadvantages for the process. One of these disadvantages, for example, is that compressed air is wasted during the process of cooling the joining tool unit, since the cooling system remains activated even after the joining tool unit has been sufficiently cooled. A further disadvantage is that the continuous activation of the cooling system results in a constant, high level of noise pollution for the operator and increases the cycle time for producing the individual connecting cables.

[0005] The document DE 10 2017 219 732 A1 relates to a welding control system for a welding system and a method for operating a welding system for an industrial plant, with which cooling of components of the welding system can be carried out as required.

[0006] The document DE 10 2013 200 994 A1 relates to a method for cooling a welding electrode.

[0007] The document DE 10 2021 126 831 A1 relates to a cooling element for a processing head of a beam processing machine.

[0008] The document DE 10 2020 131 466 A1 concerns a method for the quality-assured operation of a welding system.

[0009] The document EP 1 224 996 B1 relates to a method for cooling resistance spot welding systems. Description of the invention

[0010] The object of the invention is therefore to provide a method for cooling a joining tool unit of a joining system, with which the joining tool unit can be cooled in an energy-saving manner and thus saves costs and CO2 emissions. A further object of the invention is to provide a joining system with which the method for cooling the joining tool unit can be carried out in an energy-saving manner and thus saves costs and CO2 emissions.

[0011] These objects are achieved by the features of the independent claims. Advantageous developments of the invention are specified in the subclaims, the following description, and the figures.

[0012] According to the invention, a method is proposed for the demand-based cooling of a joining tool unit of a joining system, comprising a provision step in which the joining system, comprising a joining tool unit and a control unit and a cooling device, is provided, a first joining process, wherein in a first joining step of the first joining process a first joining part and a second joining part are joined by means of the joining tool unit, preferably by means of a material connection and / or by means of ultrasound, a temperature reading step in which an actual temperature value of the joining tool unit is read in by the control unit at the end of the first joining step, and a cooling step in which the control unit determines, based on the actual temperature value of the joining tool unit, preferably a joining tool of the joining tool unit, at the end of the first joining step,whether cooling of the joining tool unit is required or not until the start of a second joining step of a second joining process, preferably in order to reach or fall below a stored target temperature value of the joining tool unit at the start of the second joining step or at the start of a triggering step of the second joining process, and, if cooling of the joining tool unit is required, the control unit activates and / or deactivates the cooling device, preferably exclusively, until the start of the second joining step or until the start of the triggering step of the second joining process, as needed and / or in an energy-efficient manner. The demand-based and energy-efficient activation of the cooling device allows the process to be carried out in a cost- and CO2-saving manner.

[0013] For clarification, it is intended, merely by way of example, that activating the cooling device means that a cooling medium flows against, around, and / or through the joining tool unit. The cooling medium can be compressed air or, for example, water.

[0014] In order to be able to join the joining parts particularly quickly and cost-effectively, it is preferably provided that the joining system is formed by an ultrasonic welding system, wherein it is preferably provided that the joining tool unit in the ultrasonic welding system is formed by an ultrasonic sonotrode as a joining tool.

[0015] For example, it can be provided that a first joining part is formed by a connection terminal, and / or that the second joining part is formed by a stranded wire, wherein it is preferably provided that in the first joining step the connection terminal and the stranded wire are joined to form a connecting cable.

[0016] To enable the joining system to be integrated into an industrial environment with minimal effort, the cooling device cools the joining tool unit using compressed air. To achieve an even greater cooling effect, the cooling device cools the joining tool unit using a liquid, preferably water.

[0017] The control unit is designed and / or suitable to process input signals and to control components of the joining system by means of output signals.

[0018] In order to further increase the functionality of the method, it is preferably provided in all embodiments of the method and / or in all embodiments of the joining system that the control unit is formed by a control and regulating unit.

[0019] In order to control the cooling of the joining tool unit even more in line with requirements, it is provided that the cooling step comprises, as sub-steps, a calculation step, a calibration step, and a control step. It is provided that in the calculation step, the control unit calculates a forecast temperature value of the joining tool unit that is expected to be present at the beginning of the second joining step based on the actual temperature value of the joining tool unit at the end of the first joining step and on the basis of a duration of a joining step pause interval until the beginning of the second joining step and on the basis of a passive cooling rate of the joining tool unit that is present when the cooling device is not activated and preferably an extraction device of the joining system is operated in an idle state.whether the forecast temperature value is less than, equal to, or greater than a target temperature value of the joining tool unit stored in the control unit or read into the control unit at the beginning of the second joining step, wherein it is provided that in the control step, if the forecast temperature value is greater than the target temperature value, the control unit activates the cooling device within the duration of the joining step pause interval, preferably in a demand-based and / or energy-efficient manner, preferably by opening a compressed air valve of the cooling device.

[0020] In order to ensure that the cooling device reliably does not remain or is not activated for longer than necessary, a preferred embodiment provides that in the control step, the control unit calculates, based on an active cooling rate of the joining tool unit present when the cooling device and preferably an activated extraction device of the joining system are activated, and based on the duration of the joining step pause interval and based on the target temperature value, for which total cooling duration the cooling device is to be activated, preferably the compressed air valve is to be opened, so that the joining tool unit reaches or falls below the target temperature value at the start of the second joining step.

[0021] In order to ensure sufficient cooling of the joining tool unit in any case, it is preferably provided that the total cooling time is calculated by adding a basic cooling time calculated by the control unit to a safety margin, wherein it is preferably provided that the safety margin amounts to approximately 10% of the calculated basic cooling time.

[0022] For example, it can be provided that the passive cooling rate and / or the active cooling rate are stored in the control unit, wherein it is preferably provided that the passive cooling rate and / or the active cooling rate are determined in a predefined learning process carried out on the joining system, and / or wherein it is preferably provided that the passive cooling rate and / or the active cooling rate are known to an operator of the joining system and are stored by the operator in the control unit. The duration of the joining step pause interval can also be stored in the control unit.

[0023] In order to be able to distribute the total cooling time over periods that are technically favorable with regard to the joining processes, it is provided in an exemplary embodiment that in the control step the control unit calculates, based on the total cooling time and on the duration of a dead time interval of the second joining process that lies before the second joining step, whether the total cooling time is shorter, equal to, or longer than the duration of the dead time interval of the second joining process.

[0024] In order that the total cooling time can be distributed largely over process-technically preferred periods, it is provided in an exemplary embodiment that in the control step, if the total cooling time is shorter than or equal to the duration of the dead time interval of the second joining process, the control unit activates the cooling device exclusively during the duration of the dead time interval of the second joining process, and / or that in the control step, if the total cooling time is longer than the duration of the dead time interval of the second joining process, the control unit activates the cooling device during the entire duration of the dead time interval of the second joining process and additionally, preferably only, for a calculated post-cooling period which lies between the end of the first joining step and the end of the first joining process.

[0025] In order for the method to be able to be carried out with a high degree of automation, a preferred embodiment provides that the post-cooling time is calculated by the control unit on the basis of the total cooling time and on the basis of the duration of the dead time interval of the second joining process, wherein it is preferably provided that the post-cooling time is calculated by subtracting the duration of the dead time interval of the second joining process from the total cooling time.

[0026] During the joining steps, dust, particles and flakes are created which can limit the functionality of the joining system. In order to reliably prevent the functionality of the joining system from being impaired by the dust, particles and flakes, in an exemplary embodiment the joining system is provided with a suction device for suctioning away dust and / or particles and / or flakes created during the joining steps, wherein it is preferably provided that the suction device, preferably an extraction fan of the extraction device, is continuously operated at least in an idle state during the joining processes, in which the suction device, preferably an extraction fan of the extraction device, is operated with an extraction power, in particular an extraction power of approximately 10% of the maximum possible extraction power of the suction device, preferably an extraction fan of the extraction device.

[0027] In order to be able to fully utilize the extraction power of the extraction device, in particular only in temporal connection with the joining steps, it is provided in an exemplary embodiment that the extraction device is controlled by the control unit in such a way that the extraction device, preferably an extraction fan of the extraction device, is operated continuously in a full-load state during the joining steps, wherein the extraction device, preferably an extraction fan of the extraction device, is operated in the full-load state with an extraction power that is higher than the idle state or with an extraction power of 100% or approximately 100% of the maximum possible extraction power of the extraction device, preferably an extraction fan of the extraction device, wherein it is preferably provided that the extraction device is already controlled by the control unit for a predefined lead time period before the start of one, preferably each, joining step in such a way thatthat the extraction device is operated continuously in the full-load state during the pre-running period, and / or wherein it is preferably provided that the extraction device is controlled by the control unit for a predefined follow-up period after the end of one, preferably each, joining step in such a way that the extraction device, preferably an extraction fan of the extraction device, is operated continuously in the full-load state during the follow-up period.

[0028] In order to operate the extraction system as energy-efficiently as possible, it is provided, for example, that the joining system has a protective door that is operatively connected to a protective door switch of the protective door in such a way that the protective door switch transmits a closing signal to the control unit when the protective door is closed. Based on the closing signal, the control unit determines the time of the start of the first joining process and / or the time of the start of the second joining process. Preferably, the control unit calculates the time of the start of the pre-run period and / or the time of the end of the post-run period based on the closing signal.

[0029] As an alternative to the closing signal, it can be provided, for example, that the control unit determines the time of the start of the first joining process and / or the time of the start of the second joining process based on a start signal, wherein it is preferably provided that the start signal is transmitted from a sensor or a switch, for example a switch actuated by the operator of the joining system, of the joining system and / or a central control unit of the joining system to the control unit, and / or wherein it is preferably provided that the control unit calculates the time of the start of the lead time period and / or the time of the end of the follow-up time period based on the start signal.As an alternative to the switch operated by the operator of the joining system, the start signal can also be transmitted, for example, from the joining system, preferably the central control unit of the joining system, to the control unit, namely, for example only, after completion of the tensioning step or, for example only, after completion of the strand insertion step.

[0030] In order to prevent unwanted stirring up of dust and / or particles and / or flakes, it is preferably provided that the suction device is controlled by the control unit in such a way that the suction device is operated in idle mode, preferably always, when the cooling device is activated.

[0031] In order to activate the cooling device in particular in accordance with the actual temperatures present in the joining system, it is provided, for example, that the joining system has at least one temperature sensor, and that in the temperature reading step the actual temperature value of the joining tool unit is measured by means of the temperature sensor and read in by the control unit in the temperature reading step, wherein it is preferably provided that the temperature sensor is formed by an analog 2-wire temperature sensor, preferably with an output current in a range of 4 to 20 mA, or wherein it is provided that the temperature sensor is formed by an infrared sensor.

[0032] In order to be able to design the joining system in a simpler manner and to be able to carry out the process more quickly, as an alternative to reading in the actual temperature value, it can be provided that the actual temperature value is stored in an actual temperature data table of the control unit, and that the actual temperature value is read in from the temperature data table by the control unit in the temperature reading step.

[0033] To make cooling even more efficient and intelligent, the control unit is designed to be connected to a joining control unit of the joining tool unit via a signal transmission link. For example, the extraction device can also be controlled using a signal transmitted from the joining control unit to the control unit.

[0034] For example, it is provided that the cooling device is either activated or deactivated. This means that it is preferably provided that the cooling device is only activated when this is explicitly specified, i.e., the control unit activates or has activated the cooling device. An activated cooling device means that heat is supplied from the joining tool unit via the cooling device.

[0035] At this point, it should also be expressly noted that the described process is, of course, also applicable to fume extraction-guided hand torches in MIG / MAG welding. This includes all gas-shielded arc welding processes, electrode welding processes, or beam welding processes, each of which preferentially uses a shielding and / or process gas.

[0036] The invention further proposes a joining system for carrying out a method as described above. The same advantages apply to the joining system as to the method.

[0037] A method for extracting dust and / or particles and / or flakes from the joining system as described above with a provision step is described, in which the joining system, comprising the joining tool unit and the control unit, is provided for a first joining process, wherein in a first joining step of the first joining process, a first joining part and a second joining part are joined by means of the joining tool unit, and wherein the joining system has the extraction device for extracting dust and / or particles and / or flakes generated during the joining steps, and wherein the extraction device is controlled by the control unit in such a way that the extraction device, preferably an extraction fan of the extraction device, is operated continuously in a full-load state during the joining steps, and wherein the extraction device, preferably an extraction fan of the extraction device,in full load condition with an extraction capacity of 100% or approximately 100% of the maximum possible extraction capacity of the extraction device, preferably an extraction fan of the extraction device.

[0038] By way of example, in particular in the method for extracting dust and / or particles and / or flakes from the joining system as described above, it is provided that the extraction device, preferably an extraction fan of the extraction device, is operated continuously during the joining processes at least in an idle state, in which the extraction device, preferably the extraction fan, is operated with an extraction power of approximately 10% of the maximum possible extraction power of the extraction device, preferably the extraction fan.

[0039] Preferably, in particular in the method for extracting dust and / or particles and / or flakes from the joining system as described above, it is provided that the extraction device is controlled by the control unit for a predefined lead-in period before the start of one, preferably each, joining step in such a way that the extraction device is continuously operated in the full-load state during the lead-in period, and / or wherein it is preferably provided that the extraction device is controlled by the control unit for a predefined follow-up period after the end of one, preferably each, joining step in such a way that the extraction device is continuously operated in the full-load state during the follow-up period Character description

[0040] Advantageous embodiments of the invention are explained in more detail below with reference to the accompanying figures. They show: Fig. 1 shows a section of a joining system in a side view; Fig. 2 in a side view the section of the joining system according to the Fig. 1, at the end of a strand insertion step; Fig. 3 in a side view the section of the joining system according to the Fig. 1 and Fig. 2, during a first joining step; Fig. 4 in a side view the section of the joining system according to the Fig. 1, Fig. 2 and Fig. 3, at the end of the first joining step; Fig. 5 in a purely schematic block diagram, signal connections between a control unit and a cooling device and an extraction device; Fig. 6 in a purely schematic flow chart, two joining processes carried out one after the other in the joining system, and Fig. 7 in a perspective view a suction channel element of the suction device.

[0041] Based on the Fig. 1 to 6 is a method for the demand-based cooling of a, in the Fig. 1, Fig. 2, Fig. 3 and Fig. 4, a joining tool unit 1 of a joining system 3 is described. The joining system 3 has a machine bed 5 with a machine bed recess for receiving a first tool, formed by a receiving terminal 7 and inserted into the Fig. 2 to 4. In addition, the joining system 3 has movable clamping claws 9, which in their, in the Fig. 1, hold the receiving terminal 7 in the machine bed recess and clamp it against the machine bed 5.

[0042] In addition, the joining system 3 includes the joining tool unit 1, which is formed here merely by an ultrasonic sonotrode, as an example. Using the joining tool unit 1, the receiving terminal 7 can be joined as the first joining part with, for example, a stranded wire 11 as the second joining part by means of ultrasonic welding. During ultrasonic welding, the joining tool unit 1 heats up.

[0043] To cool the joining tool unit 1, the joining system 3 has a cooling device 21, which here merely exemplifies a compressed air nozzle 23 and a compressed air valve 25. A compressed air outlet of the compressed air nozzle 23 is directed toward the joining tool unit 1 for cooling the joining tool unit 1.

[0044] In order to extract particles, dust and flakes that are generated during ultrasonic welding, the joining system 3 has an extraction device 31. The extraction device 31 has two extraction channel elements 33, each of which is in flow connection with an extraction fan (not shown) of the extraction device 31. In the Fig. 7 shows one of the suction duct elements 33 with its air inlet 35 in a perspective view.

[0045] As this is the case in the Fig. As shown in Figure 5, the joining system 3 also has a central control unit 41 and a control unit 43 for the demand-based and energy-efficient control of the cooling device 21 and for the demand-based and energy-efficient control of the extraction device 31. The control unit 43 is in signal transmission connection (dashed line) with the central control unit 41 as well as in signal transmission connection (dashed line) with a temperature sensor 45. The temperature sensor 45 is formed, here merely by way of example, by an analog 2-wire temperature sensor with an output current in a range of 4 to 20 mA. The temperature sensor continuously measures the temperature of the joining tool unit. Of course, in this or another embodiment of the joining system 3, the temperature sensor can also be formed, for example, by an infrared sensor.

[0046] As is also the case in the Fig. As shown in Figure 5, the joining system 3 further comprises a data storage unit 47, which can, for example, be part of the control unit 43 or part of the central control unit 41. The control unit 43 is in signal transmission connection (dashed line) with the data storage unit 47.

[0047] Depending on input signals from the temperature sensor 45 and / or input signals from the central control unit 41 and / or data that the control unit 43 reads from the data storage unit 47, the control unit 43 controls the cooling device 21 and the extraction device 31 in a demand-oriented and energy-efficient manner. For this purpose, the control unit 43 is additionally in signal transmission connection (dashed line) with the cooling device 21, and here only as an example in signal transmission connection (dashed line) with the, also in the Fig. 1, compressed air valve 25 of the cooling device 21. In addition, the control unit 43 is in signal transmission connection (dashed line) with a fan control 49 of the extraction fan.

[0048] The following is based in particular on the Fig. 6, the execution of a first joining process I in the joining system and a second joining process II, which follows the first joining process I, is described.

[0049] At the beginning of the first joining process I, the receiving terminal 7 is inserted into the machine bed recess by an operator of the joining system 3 in a terminal insertion step 101 of the first joining process I. Subsequently, the clamping claws 9 are moved from their rest position to their Fig. 2, Fig. 3 and Fig. 4. After completion of the clamping step 103, the receiving terminal 7 is fixed in the machine bed recess and clamped against the machine bed 5.

[0050] Subsequently, in a partial removal step 105 of the first joining process I, a partial strip of insulation from the strand 11 still present on the strand 11 is removed by the operator, and the strand 11 is then inserted into the joining system 3 and placed onto the receiving terminal 7 by the operator in a strand insertion step 107 of the first joining process I. Subsequently, in a triggering step 109 of the first joining process I, a protective door (not shown) of the joining system 3 is closed by the operator. As a result, a protective door switch of the protective door transmits a closing signal to the central control unit 41 in the triggering step 109, whereupon the central control unit 41 triggers a first joining step 111 of the first joining process I, which is subsequently carried out and in which the stranded wire 11 is welded to the receiving terminal 7 by means of ultrasonic welding or another, preferably material-bonded, joining process.

[0051] Following the first joining step 111, a post-treatment step 113 of the first joining process I is performed in the first joining process I, in which the connecting cable comprising the stranded wire 11 and the receiving terminal 7 is cut or crimped, for example. Following the post-treatment step 113 is a removal step 115 of the first joining process I, in which the operator removes the post-treated connecting cable from the joining system 3. The first joining process I is thus completed.

[0052] The first joining process I is followed by the second joining process II after an initial setup time R1. During the first setup time R1, the operator makes preparations for the second joining process II. For example, he picks up another terminal and another strand.

[0053] The sequence of the second joining process II is identical to the first joining process I. At the beginning of the second joining process II, the operator of the joining system 3 inserts the additional receiving terminal into the machine bed recess in a terminal insertion step 201 of the second joining process II. Subsequently, the clamping claws 9 are moved from their rest position to their Fig. 2, Fig. 3 and Fig. 4. After completion of clamping step 203, the additional receiving terminal is thus fixed in the machine bed recess and clamped against the machine bed 5.

[0054] Subsequently, in a partial withdrawal step 205 of the second joining process II, a partial withdrawal still present on the additional strand is removed by the operator, and the additional strand is then inserted into the joining system 3 and placed onto the additional receiving terminal by the operator in a strand insertion step 207 of the second joining process II. Subsequently, in a triggering step 209 of the second joining process II, the operator closes the protective door (not shown) of the joining system 3. The protective door switch of the protective door subsequently transmits a closing signal to the central control unit 41, whereupon the central control unit 41 triggers a second joining step 211 of the second joining process II, which is subsequently carried out and in which the additional strand is welded to the additional receiving terminal by means of ultrasonic welding or another, preferably material-bonded, joining method.

[0055] Following the second joining step 211, a post-processing step 213 of the second joining process II is performed, in which a further connecting cable comprising the further strand and the further receiving terminal is cut or crimped, for example. Following the post-processing step 213 is a removal step 215 of the second joining process II, in which the operator removes the post-processed connecting cable from the joining system 3. The second joining process II is thus completed. A second setup time can follow the second joining process II, and further joining processes can then be performed.

[0056] The following describes the demand- and energy-efficient control of the extraction device 31 and the demand- and energy-efficient control of the cooling device 21 based on the joining processes described in detail above, i.e. the first joining process I and the second joining process II.

[0057] By closing the safety door in the first joining process I, the control unit 43 recognizes, based on the closing signal transmitted by the safety door switch, that the first joining step 111 should be started or can be started by the joining system 3. Based on the closing signal and a start time delay stored in the data storage unit 47 and a joining process duration stored in the data storage unit 47, the control unit 43 determines a start time and an end time for the first joining step 111.

[0058] Depending on the start time and the end time of the first joining step 111, the control unit 43 transmits a full-load signal to the fan control 73, which then controls the extraction fan in such a way that the extraction fan is operated continuously in a full-load state for a predefined lead time period before the start of the first joining step and during the first joining step and for a predefined follow-up time period after the end of the first joining step, in which the extraction fan is operated with an extraction power of 100% or approximately 100% of the maximum possible extraction power of the extraction device.

[0059] Otherwise, i.e., before the predefined pre-run time, during the first joining step 111, and after the predefined post-run time, the extraction fan is continuously operated at least in an idle state, in which the extraction fan is operated with an extraction power of approximately 10% of the maximum possible extraction power of the extraction fan. This ensures at least a minimal extraction effect throughout. Furthermore, this avoids the energy-intensive repeated restarting of the extraction fan during the joining processes. In the event that the operator should leave his workstation for an extended period during one of the setup times, it can still be provided that the extraction fan is put into a standby state by the control unit 43 after a predefined waiting time, in which the extraction fan is out of operation.

[0060] In order to operate not only the extraction device 31 but also the cooling device 21 in a demand-based and energy-efficient manner, at the end of the first joining step 111, an actual temperature value of the joining tool unit 1 is measured using the temperature sensor 45 in a temperature reading step and read into the control unit 43. A cooling step is then carried out, in which the control unit 43 determines, based on the actual temperature value of the joining tool unit 3 at the end of the first joining step 111, whether or not cooling of the joining tool unit 3 is required until the start of the second joining step 211. If it has been determined in the control unit 43 that cooling of the joining tool unit 3 is required, the control unit 43 controls the cooling device 21, more precisely the compressed air valve 25, in such a way that the cooling device 21 is activated or deactivated as needed and in an energy-efficient manner until the start of the second joining step 211.For this purpose, the cooling step comprises a calculation step, a calibration step, and a control step as sub-steps. If cooling of the joining tool unit 1 is not required until the second joining step 211, the cooling device 21 is not activated by the control unit 43; more precisely, the compressed air valve 25 is not opened by the control unit 43.

[0061] In the calculation step, the control unit 43 calculates a forecast temperature value of the joining tool unit 1 that is expected to be present at the beginning of the second joining step 211 based on the actual temperature value of the joining tool unit 3 at the end of the first joining step 111 and on the duration of a joining step pause interval III between the end of the first joining step 111 and the beginning of the second joining step 211, as well as on the basis of a passive cooling rate of the joining tool unit 1. In other words: the control unit 43 forecasts the actual temperature value of the joining tool unit 1 at the beginning of the second joining step 211, provided that no active cooling of the joining tool unit 1, be it by means of the cooling device 21 or by means of the suction device 31, would take place.The passive cooling rate of the joining tool unit 1 corresponds to the cooling rate that occurs when the cooling device is not activated and the extraction device of the joining system 3 is operating in the idle state. The passive cooling rate can be, for example, approximately 2.5 K / s. The duration of the joining step pause interval III can be stored in the data storage unit 47 and read in by the control unit 43. Alternatively, the duration of the joining step pause interval III can also be stored in the central control unit 41 and read in by the control unit 43. Alternatively, i.e., in this or another embodiment of the method, the joining step pause interval can also lie between the end of the first joining step 111 and the beginning of the triggering step 209 of the second joining process II.

[0062] Subsequently, in the comparison step, the control unit 43 compares whether the forecast temperature value is less than, equal to, or greater than a target temperature value of the joining tool unit 1 at the beginning of the second joining step 211, which target temperature value is stored in the control unit 43 or the data storage unit 47 and read in by the control unit 43. If the forecast temperature value calculated by the control unit 43 is greater than the target temperature value, the control unit 43 will, in the control step, activate the cooling device 21 exclusively within the duration of the joining step pause interval III in a demand-based and energy-efficient manner; more precisely, it will open the compressed air valve 25.

[0063] In order to be able to operate the cooling device 21 even more energy-efficiently, the control unit 43 additionally calculates, during the control step, based on an active cooling rate of the joining tool unit 1 and the duration of the joining step pause interval III and the target temperature value of the joining tool unit 1 at the beginning of the second joining step 211, a necessary total cooling time in order to cool the joining tool unit 1 to at least the target temperature value or below by the beginning of the second joining step 211. The active cooling rate of the joining tool unit 1 corresponds to the cooling rate that occurs when the cooling device 21 is activated and, during the run-on period, when the extraction device 31 is activated. The active cooling rate can be, for example, approximately 10 K / s.The active cooling rate and the passive cooling rate can, for example, be stored in the data storage unit 47 and read by the control unit 43. In particular, the active cooling rate and the passive cooling rate can be determined in a predefined learning process (a so-called teaching process) carried out on the joining system 3.

[0064] In order to enable the cooling device 21 to be activated within the joining step pause interval III at times that are particularly favorable, particularly with regard to process control, the control unit 43 calculates during the activation step based on the total cooling duration and on the duration of a dead time interval IV of the second joining process II that precedes the second joining step 211 and is due to the joining process or the system, whether the total cooling duration is shorter than, equal to, or longer than the duration of the dead time interval IV of the second joining process II. The dead time interval IV of each joining process, in particular also of the second joining process II, extends from the beginning of the clamping step 203 to the end of the second joining step 211. The duration of the dead time interval IV and the starting time of the dead time interval IV of the second joining process II can, for example, be stored in the data storage unit 47 and can be retrieved by the control unit 43. be read in.Alternatively, the start time and the duration of the dead time interval IV can be determined in the learning process.

[0065] If the total cooling time is less than or equal to the duration of the dead time interval IV of the second joining process II, the control unit 43 activates the cooling device 21, more precisely the control unit 43 opens the compressed air valve 25, activated exclusively during the duration of the dead time interval IV of the second joining process II.

[0066] If the total cooling duration is longer than the duration of the dead time interval IV of the second joining process II, the control unit 43 activates the cooling device 21, more precisely, the control unit 43 opens the compressed air valve 25, for the entire duration of the dead time interval IV of the second joining process II and additionally only for a post-cooling duration calculated by the control unit 43. The post-cooling duration lies between the end of the first joining step 111 and the end of the first joining process I. The post-cooling duration is calculated by the control unit 43 based on the total cooling duration and the duration of the dead time interval IV of the second joining process II, wherein the post-cooling duration is obtained by subtracting the duration of the dead time interval IV of the second joining process II from the total cooling duration.

[0067] The cooling device 21 is always activated only after a suction process carried out by means of the suction device 31 has been largely or completely completed. LIST OF REFERENCE SYMBOLS 1 joining tool unit 3 Joining system 5 Machine bed 7 Recording terminal 9 clamping claw 11 strands 21 Cooling device 23 Compressed air nozzle 25 compressed air valve 31 Extraction device 33 Suction duct element 35 Air intake 41 Central control unit 43 Control unit 45 Temperature sensor 47 Data storage unit 49 Fan control 101 Terminal insertion step 103 clamping step 105 Partial deduction step 107 Strand insertion step 109 Trigger step 111 first joining step 113 Post-treatment step 115 Removal step 201 Terminal insertion step 203 clamping step 205 Partial deduction step 207 Strand insertion step 209 Trigger step 211 second joining step 213 Post-treatment step I first joining process II second joining process III Joining step pause interval IV Dead time interval R1 first setup time

Claims

[1] Method for the demand-based cooling of a joining tool unit of a joining system, comprising: a provision step in which the joining system (3), comprising a joining tool unit (1) and a control unit (43) and a cooling device (21), is provided, a first joining process (I), wherein in a first joining step (111) of the first joining process (I) a first joining part and a second joining part are joined by means of the joining tool unit (1), a temperature reading step, in which the control unit (43) reads in an actual temperature value of the joining tool unit (1) at the end of the first joining step (111), and a cooling step in which the control unit (43) determines, based on the actual temperature value of the joining tool unit (1) at the end of the first joining step (111), whether or not cooling of the joining tool unit (1) is required until the start of a second joining step (211) of a second joining process (II), and, if cooling of the joining tool unit (1) is required, the control unit (43) activates and / or deactivates the cooling device (21) until the start of the second joining step (211) as needed and / or in an energy-efficient manner, wherein the cooling step comprises as sub-steps a calculation step and a calibration step and a control step, wherein it is provided that in the calculation step, the control unit (43) uses the actual temperature value of the joining tool unit (1) at the end of the first joining step (111) and a duration of a joining step pause interval (III) until the start of the second joining step (211) and based on a passive cooling rate of the joining tool unit (1) present when the cooling device (21) is not activated and preferably an extraction device (31) of the joining system (3) is operated in an idle state, a forecast temperature value of the joining tool unit (1) that is expected to be present at the beginning of the second joining step (211) is calculated, and wherein it is provided that in the adjustment step the control unit (43) adjusts whether the forecast temperature value is smaller or is equal to or greater than a target temperature value of the joining tool unit (1) stored in the control unit (43) or read into the control unit (43) at the beginning of the second joining step (211), wherein it is provided that in the control step, if the forecast temperature value is greater than the target temperature value, the control unit (43) activates the cooling device (21) within the duration of the joining step pause interval (III). [2] Method according to claim 1, characterized by that in the control step, the control unit (43), before the cooling device (21) is activated, calculates, on the basis of an active cooling rate of the joining tool unit (1) present when the cooling device (21) and preferably an activated suction device (31) of the joining system (3) are activated, and on the basis of the duration of the joining step pause interval (III) and on the basis of the target temperature value, for which total cooling duration the cooling device (21) is to be activated, preferably the compressed air valve (25) is to be opened, so that the joining tool unit (1) reaches or falls below the target temperature value at the start of the second joining step (211). [3] Method according to claim 2, characterized byin that in the control step, the control unit (43) calculates, on the basis of the total cooling time and on the basis of a time duration of a dead time interval (IV) of the second joining process (II) prior to the second joining step (211), whether the total cooling time is shorter, equal to, or longer than the time duration of the dead time interval (IV) of the second joining process (II). [4] Method according to claim 3, characterized bythat in the control step, if the total cooling duration is shorter than or equal to the duration of the dead time interval (IV) of the second joining process (II), the control unit (43) activates the cooling device (21) exclusively during the duration of the dead time interval (IV) of the second joining process (II), and / or that in the control step, if the total cooling duration is longer than the duration of the dead time interval (IV) of the second joining process (II), the control unit (43) activates the cooling device (21) during the entire duration of the dead time interval (IV) of the second joining process (II) and additionally, preferably only, for a calculated post-cooling duration which lies between the end of the first joining step (111) and the end of the first joining process (I). [5] Method according to claim 4, characterized bythat the post-cooling time is calculated by the control unit (43) on the basis of the total cooling time and on the basis of the duration of the dead time interval (IV) of the second joining process (II), wherein it is preferably provided that the post-cooling time is calculated by subtracting the duration of the dead time interval (IV) of the second joining process (II) from the total cooling time. [6] Method according to one of the preceding claims, characterized by that the joining system (3) has a suction device (31) for sucking away dust and / or particles and / or flakes produced during the carrying out of the joining steps (111; 211), wherein it is preferably provided that the suction device (31), preferably an extraction fan of the suction device (31), is arranged during the joining processes (I; II) is operated continuously at least in an idle state, in which the suction device (31), preferably a suction fan of the suction device (31), is operated with a reduced suction power of the suction device (31), a suction fan of the suction device (31). [7] Method according to claim 6, characterized bythat the suction device (31) is controlled by the control unit (43) in such a way that the suction device (31), preferably an extraction fan of the suction device (31), is operated continuously in a full-load state during the joining steps (111; 211), wherein the suction device (31), preferably an extraction fan of the suction device (31), is operated in the full-load state with a higher extraction power than in the idle state, wherein it is preferably provided that the suction device (31) is already controlled by the control unit (43) for a predefined lead time period before the start of one, preferably each, joining step (111;211) is controlled in such a way that the extraction device (31), preferably an extraction fan of the extraction device (31), is operated continuously in the full-load state during the pre-run period, and / or wherein it is preferably provided that the extraction device (31) is controlled by the control unit (43) for a predefined follow-up period after the end of one, preferably each, joining step (111; 211) in such a way that the extraction device (31), preferably an extraction fan of the extraction device (31), is operated continuously in the full-load state during the follow-up period. [8] Joining system for carrying out a method according to one of the preceding claims.

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