System and method for the quality-safe cleaning of workpieces and / or tools

Abstract

The invention relates to a system for the quality-assured cleaning of workpieces and / or tools, comprising an inlet module (2), a cleaning module (3) with several air-operated, centrifugal force-controlled rotary nozzles (16), an outlet module (4), and a higher-level control unit (8). A conveying device (5) is provided on which the workpieces (6) or tools (6) are successively moved through the modules (2, 3, 4) of the modular system (1). The higher-level control unit (8) controls the speed of the conveying device (5) such that the workpieces (6) or tools (6) are cleaned of contaminating particles located on the surface of the workpiece (6) or tool (6) during their passage through the cleaning module (3). A suction device (9) is assigned to the cleaning module (3), and the higher-level control unit (8) controls the suction device (9) in such a way that...that the particles removed from the surface of the workpieces (6) or tools (6) are removed with the extracted airflow from the cleaning module (3).

Description

[0001] The invention relates to a system and a method for quality-assured cleaning and / or drying of workpieces and / or tools.

[0002] German patent DE 10 2021 004 998 B1 discloses a system for cleaning and / or drying at least one workpiece and / or tool using a fluid medium. This system comprises several rotary nozzles arranged in series, which direct the medium (compressed air, cleaning fluid) precisely onto the workpieces or tools to remove adhering contaminants. The rotary nozzles are designed to be set in rotation by the medium. Each of these rotary nozzles is continuously monitored with respect to a predetermined rotational speed, so that not only a failure but also a gradual change in the rotational speed of a rotary nozzle is detected. This makes it possible to take appropriate countermeasures at an early stage before the affected rotary nozzle no longer functions correctly or fails completely.

[0003] Each rotary nozzle has a connection component for connecting to a line carrying the fluid medium and a rotary component rotatably mounted on the connection component relative to the longitudinal axis of the rotary nozzle. Rotary nozzles that can be used in the cleaning system are known, for example, from DE 100 49 633 C2 and DE 10 2017 009 773 A1.

[0004] In many cases, workpieces or tools are manufactured using machining processes. The system described above is ideally suited for cleaning these workpieces or tools of loose chips or particles. However, there are also critical applications where it must be ensured that all particles and contaminants are completely removed from the surface of the workpieces after the cleaning process, as otherwise the functionality of these workpieces cannot be guaranteed. A good example of this is the cleaning of battery modules. Battery modules are joined using laser welding. During laser welding, electrically conductive soot particles are formed, which are deposited on the surface of the battery modules.These must be completely removed, otherwise there is a risk of a short circuit and damage or destruction of the insufficiently cleaned battery module when electrically connecting a battery module.

[0005] When cleaning with rotary nozzles, another problem generally arises: Particles (of whatever type) detached from the surface of the workpieces / tools collect in the exhaust system's filter. As the particle load increases, this inevitably leads to a decrease in the extraction velocity and the volume of extracted air, even with unchanged extraction rates. This, in turn, negatively impacts the quality of the cleaning process, as the particles are no longer completely removed from the area around the workpieces / tools. Especially in cleaning processes where the cleaning is crucial for the functionality of the workpieces, it is insufficient to simply monitor the correct operation of the cleaning system's rotary nozzles. Instead, monitoring of the entire system in which the cleaning process takes place is also necessary.

[0006] The invention is based on the objective of providing a system and a method for cleaning workpieces / tools that ensures that the workpieces / tools consistently exhibit a required degree of cleanliness.

[0007] The task is solved by a system for the quality-assured cleaning of workpieces and / or tools, comprising the following components: an inlet module, an outlet module, and a cleaning module with multiple cleaning nozzles located between the inlet and outlet modules. The cleaning nozzles are, in particular, controllable, fluid-operated cleaning nozzles. Furthermore, the cleaning module includes an air supply device and an extraction device for removing the exhaust air laden with contaminated particles from the cleaning module. A conveyor system moves the workpieces or tools successively through the modules. A higher-level control / evaluation unit regulates various system parameters to target values ​​determined in a prior test phase, ensuring that the workpieces or tools achieve the required degree of cleanliness after passing through the cleaning module.The parameters include, for example, the speed of the conveying device, the volume flow of the air supply to the cleaning module, and the volume flow of the exhaust air extraction from the cleaning module.

[0008] The control unit also considers information provided by other sensors that measure or monitor various process parameters within the system. In particular, an extraction device is assigned to the cleaning module in the outlet module. The higher-level control unit regulates the airflow of the extraction device in such a way that the particles removed from the surface of the workpieces or tools are carried away from the cleaning module by the extracted airflow. Specifically, it ensures that the air contaminated with particles is completely removed from the cleaning module.

[0009] According to a further development of the system according to the invention, the extraction device associated with the discharge module is connected to the cleaning module via at least one pipe connection. Sensors are assigned to the pipe connection between the cleaning module and the extraction device, measuring the velocity, pressure, and / or volumetric flow rate of the air extracted from the cleaning module, which contains the particles detached from the workpieces or tools. The measurement data determined by the sensors are transmitted to the higher-level control unit via a bus system. For example, the control unit can detect a decrease in the extraction velocity and volumetric flow rate to determine whether a filter / filter system replacement is necessary. If so, it generates a corresponding message for the operating personnel.

[0010] Furthermore, in connection with the system according to the invention, it is proposed that the infeed module be assigned a sensor positioned to detect the static charge of each of the workpieces or tools passing through. Additionally, an ionization electrode / discharge electrode is arranged downstream of the sensor detecting the static charge in the direction of travel of the conveyor. Monitoring the electrical parameters of the electrode allows conclusions to be drawn about its degree of contamination and effectiveness. This electrode is positioned to neutralize electrical charges on the workpieces or tools. Preferably, a second ionization electrode is also assigned to the outfeed module. This second ionization electrode neutralizes electrical charges on the workpieces or tools that have accumulated during the cleaning process.It should also be mentioned that there are rotary nozzles with an integrated discharge electrode for electrical charging. The parameters of the electrode associated with the discharge module are also monitored. This ensures that specified target values ​​are maintained within the tolerance limits.

[0011] The aforementioned design is of great importance when it must be ensured that the workpieces or tools to be cleaned, e.g., battery modules, are not statically charged for the reasons already mentioned. Again, all data supplied by the sensor are transmitted to the higher-level control unit and recorded in a storage medium, so that they are available at any time as process documentation.

[0012] An advantageous further development of the system according to the invention provides that the inlet module is equipped with sensors, in particular for pressure and volume measurement. Based on the measurement data, the higher-level control unit adjusts the pressure and volume of the compressed air supplied to the cleaning module so that the workpieces or tools exhibit the required degree of cleanliness after passing through the cleaning module. Here, too, all determined or set data are recorded. Thus, it is possible at a later time to demonstrate that the cleaning module maintained all specified target values ​​during a cleaning process. The cleaned workpieces / tools therefore exhibit a verifiable degree of cleanliness.

[0013] The following design of the cleaning module is considered particularly advantageous: The cleaning module has several centrifugally controlled rotary nozzles arranged so that the airflow they provide covers the entire surface of the workpieces or tools to be cleaned. For example, in the case of battery modules, several rotary nozzles are distributed over a predetermined area. Centrifugally controlled rotary nozzles are offered and sold by the applicant in various configurations.

[0014] Preferably, the cleaning module is a speed-monitored, self-contained system, in which the correct function of the individual rotary nozzles is monitored by a separate, dedicated control / evaluation unit. Each rotary nozzle is assigned a speed sensor that continuously acquires measurement data about the rotational speed of the nozzle and makes it available to the control / evaluation unit. This unit then forwards the data to the higher-level control system. The control / evaluation unit also generates a message for the higher-level control system if the rotational speed of one of the rotary nozzles, as transmitted by one of the speed sensors, deviates from a predefined rotational speed of the nozzle. A more detailed description of an embodiment of the self-contained cleaning module used in the system according to the invention can be found in the description of the figures. Fig. 3 . A design of a corresponding cleaning module was also recently described in detail in a patent of the applicant.

[0015] The problem is further solved by a method for determining setpoints for the various manipulated variables / parameters of the system according to the invention. The corresponding setpoints are used by the higher-level control unit to control the individual parameters of the infeed and outfeed modules. The setpoints are dimensioned such that quality-assured cleaning of the workpieces or tools is guaranteed when they pass through the modular system. In a first step, the setpoints for the transport speed of the conveyor and the setpoints for the sensors of the individual modules are determined in a test phase. In a second step, the higher-level control unit controls the system during regular cleaning operation based on the setpoints determined in the test phase.In this process, the target values ​​are determined experimentally or via a digital simulation method using a CAD system during the test phase.

[0016] Furthermore, in connection with the method according to the invention, it is provided that the optimal rotational speed for each of the rotary nozzles is determined in the test phase, and that the control / evaluation unit assigned to the cleaning module monitors the rotational speed of the individual rotary nozzles to the speed determined in the test phase during regular operation.

[0017] In order to have information about the operation of the individual components and modules of the system according to the invention available at any time during the cleaning process, the higher-level control unit is designed to record and document all set or determined data and, if applicable, error messages.

[0018] The invention is explained in more detail with reference to the following figures. They show: Fig. 1 : a schematic representation of the system according to the invention and Fig. 2 : a sketched representation of the components of the cleaning module. Fig. 3 : a known rotary nozzle 1 with two collinearly arranged arms and Fig. 4 : one to Fig. 1 Analog representation of the system according to the invention.

[0019] Fig. 1 and Fig. 4 Figure 1 shows a schematic representation of the system according to the invention for cleaning workpieces 6 or tools 6. The two figures differ essentially only in design.

[0020] The system 1 according to the invention has three main modules: an inlet module 2, a cleaning module 3 and an outlet module 4. The cleaning module 3 is a self-contained system of speed-monitored rotary nozzles 16, which is shown in the figures. Fig. 2 and Fig. 3 The transport of the workpieces 6 or tools 6 through the system 1 according to the invention is carried out via a conveying device 5 - usually a conveyor belt - which moves the workpieces 6 or tools 6 via the inlet 2, through the cleaning module 3 to the outlet 4.

[0021] The inlet module 2 is equipped with a sensor 13, primarily for pressure and volume measurement. The sensor 13 provides the higher-level control unit 8 with information, in particular, about the pressure and volume of the compressed air supplied to the rotary nozzles 16 of the cleaning module 3. This compressed air is dimensioned such that the workpieces 6 or tools 6 achieve the required degree of cleanliness after passing through the cleaning module 3. Here, too, all measured data – target and actual values ​​– are continuously recorded.

[0022] Furthermore, a sensor 10 is provided in the area of ​​the infeed module 2, which detects any static electrical charge on the passing workpieces 6 or tools 6. An ionization electrode / discharge electrode 10 is arranged downstream of the sensor 11 for measuring the static electrical charge in the direction of travel of the conveyor 5. This electrode is positioned so that it dissipates any electrical charges on the workpieces 6 or tools 6 and neutralizes them.

[0023] Cleaning module 3 is largely already known from the prior art mentioned in the introduction. In the figures Fig. 2 and Fig. 3 The essential components will be described again.

[0024] The discharge module 4 is associated with an extraction device 9. The extraction device 9 is connected to the cleaning module 2 via a pipe connection 7. A sensor 12 is arranged in the pipe connection 7 between the cleaning module 3 and the extraction device 9. This sensor measures the velocity and / or volume flow rate of the air extracted from the cleaning module 3, which contains the particles detached from the workpieces 6 or tools 6. A pressure drop and / or a reduction in the volume flow rate of the extracted air—which may indicate clogging of the filter system—can be detected early via the measured parameters. The discharge module 4 is also associated with an ionization electrode 10, which dissipates any charges on the workpieces 6 or tools 6 that accumulated during the cleaning process.

[0025] To ensure the cleaning process delivers consistently high-quality results, the target values ​​must be known. These values ​​are used by the higher-level control system 8 to regulate the conveying device 5, the air supply to the rotary nozzles 16, the extraction of the particle-contaminated exhaust air, and so on. All required target values ​​for the sensors and actuators are determined during a test phase. In the regular cleaning phase, the higher-level control system 8 controls the components of the system 1 according to the invention in accordance with the target values ​​determined in the test phase. These target values ​​are determined either experimentally or using a digital simulation method (CAD method) during the test phase.

[0026] During the test phase, the optimal rotational speed for each of the rotary nozzles 16 of the cleaning module 3 is also determined. The rotational speed of each individual rotary nozzle used in the cleaning module 3 is monitored via the control / evaluation unit 27.

[0027] To ensure complete documentation of the cleaning process, target and actual data from each component and sensor are recorded and documented. This data is accessible to the system's operating personnel at any time via a dedicated control / display module (not shown).

[0028] Fig. 2 Figure 1 shows a sketched representation of the components of the cleaning module for cleaning and / or drying at least one workpiece and / or tool using a fluid medium. In this case, the fluid medium is compressed air. The compressed air is contained in a suitably designed container 15, which is associated with the inlet 2. It goes without saying that, depending on the application, a liquid, such as a cleaning fluid, can also be used as the fluid medium. The workpieces or tools are in Fig. 2 not shown separately.

[0029] The system consists of several rotary nozzles 16, which may have different designs, each attached to a mounting unit 18 via an adapter unit 17. In the illustrated case, the mounting unit 18 is a linear rail, and the rotary nozzles 16 are arranged in a row on the mounting unit 18. In conjunction with the solution according to the invention, the arrangement of the rotary nozzles 16 is adapted to the respective shape of the workpieces 6 or tools 6 to be cleaned. If the workpieces 6 are, for example, flat battery modules, the rotary nozzles 16 are positioned in a flat arrangement – ​​several rows of rotary nozzles are arranged parallel to each other. Essential components of each rotary nozzle 16 are a stationary base body 19 with a connection for attaching the line 20 and a rotating component 21, which is rotatably mounted on the base body 19 about the longitudinal axis of the rotary nozzle 16.The bearings are usually provided by ball bearings, e.g. by two miniature spindle bearings.

[0030] Compressed air flows through a passage (not shown) in the rotary nozzle 16 to at least one drive nozzle 22 and at least one working nozzle 23, both of which are associated with the rotating component 21. Each working nozzle 23 is designed and arranged so that the fluid medium flows out directed towards the workpieces or tools. Each drive nozzle 22 is associated with a centrifugal force control unit (not shown separately). This unit ensures that the rotation of the rotating component 21 of the rotary nozzle 16 occurs at a predetermined speed. The centrifugal force control unit is preferably designed such that, depending on the current speed of the rotating component 21, it automatically enlarges or reduces the outlet opening of the drive nozzle 22 for the compressed air by means of a spring-loaded weight, thereby ensuring that the rotating component 21 rotates at a substantially constant speed.Preferably, the rotary nozzles 16 exhibit an essentially symmetrical design, which effectively avoids the occurrence of imbalances.

[0031] Fig. 3 Figure 1 shows a rotary nozzle 1 with two collinearly arranged arms on which the working nozzles 23 and drive nozzles 22 are arranged. Detailed information on this type of rotary nozzle 1 can be found in DE 100 49 633 C2. Another suitable rotary nozzle is described in detail in DE 10 2017 009 773 A1.

[0032] Each rotary nozzle 16 is mechanically connected to the mounting unit 18 via an adapter unit 17. The adapter unit 17 is also equipped with a circuit board 24 with electrical connectors 25. The circuit board 24 provides the connection to the bus system 26. The rotary nozzles 16 communicate with each other via the bus system 26, and in particular with the control / evaluation unit 27; the components 16 are also powered via the bus system 26.

[0033] Each adapter unit 17 is equipped with a speed sensor 28 for determining the rotational speed of the associated rotary nozzle 16. The speed sensors 28 are preferably sensors that operate on the inductive principle. An inductive component 29 is provided in the adapter unit 17, which interacts with at least one electrically conductive marking element 30 that is fixedly connected to the rotary component 21. The marking element 30 can, for example, be configured as described in DE 10 2021 004 998 A1.

[0034] The control / evaluation unit 27 generates a message as soon as the rotational speed transmitted by one of the "intelligent" speed sensors 28 deviates from the preset rotational speed of the corresponding rotary nozzle 16. It is also possible to forward the data supplied by the speed sensors 28 via a network to a remote display unit using the HTML protocol. The display unit can, of course, also be assigned to a business service portal, a PC, or a mobile phone. The data supplied by the rotary nozzles 16 or the speed sensors 28 can be displayed graphically on the display unit. Ideally, the user has all relevant information available at a glance on the display.

[0035] Communication on bus system 16 takes place via one of the bus protocols commonly used in automation technology, for example, the CAN bus protocol. The speed sensors 28 of the rotary nozzles 16 and the control evaluation unit 27 exchange information via bus system 16 – the bus protocol runs on a twisted-pair cable. Since all data is transmitted via only two wires in the CAN bus (Controlled Area Network), the wiring effort can be significantly reduced, thus lowering costs. A further major advantage of using a bus system 26 is that additional bus participants or rotary nozzles 16 can be added or removed subsequently: only the connection to the bus line needs to be established or disconnected. This aspect plays a particularly important role in troubleshooting and repair.If one of the bus participants fails for any reason, this has no immediate impact on the system's functionality. All functioning bus participants can continue to communicate without restriction. Bezugszeichenliste

[0036] 1. System according to the invention 2. Inlet module 3. Cleaning module 4. Outlet module 5. Conveyor belt / conveying device 6. Workpiece / tool 7. Extraction nozzle 8. Higher-level control unit / PLC 9. Extraction module 10. Ionization device / discharge electrode 11. Sensor for measuring static charge 12. Sensors for monitoring the extracted airflow 13. Sensors for monitoring the inlet module 14. Feed nozzle 15. Container 16. Rotary nozzle 17. Adapter unit 18. Mounting unit 19. Base body 20. Cable 21. Rotary component 22. Drive nozzle 23. Working nozzle 24 25. Connector element 26. Bus system 27. Control / evaluation unit 28. Speed ​​sensor 29 30. Electrically conductive marking element 31. Display / indicator unit 32. Input unit 33. Housing

Claims

1. Modular system for the quality-assured cleaning of workpieces (6) and / or tools (6) comprising an inlet module (2), an outlet module (4), a cleaning module (3) arranged between the inlet module (2) and the outlet module (4) with several controllable, fluid-operated cleaning nozzles, an air supply device (14) associated with the cleaning module (3), an extraction device (9) for extracting the exhaust air loaded with contaminating particles from the cleaning module (3), a conveying device (5) on which the workpieces (6) or tools (6) are successively moved through the modules (2, 3, 4), and a higher-level control / evaluation unit (8) that regulates the speed of the conveying device (5) and parameters that determine the air supply to the cleaning module (3) and the extraction of the exhaust air from the cleaning module (3) to target values ​​that were determined in a test phase.so that the workpieces (6) or tools (6) have a required degree of cleanliness after passing through the cleaning module (3).

2. System according to claim 1, wherein the extraction device (9) is connected to the cleaning module (3) via at least one pipe connection (7), and wherein a sensor (12) is arranged in the pipe connection (7) of the cleaning module (3) and the extraction device (9), which measures the velocity and / or the pressure and / or the volume flow of the air extracted from the cleaning module (3), in which the particles detached from the workpieces (6) or tools (6) are contained.

3. System according to claim 1 or 2, wherein the inlet module (2) is associated with a sensor (10) which is arranged to detect the static charge of each of the passing workpieces (6) or tools (6).

4. System according to claim 3, wherein an ionization electrode (11) is arranged behind the sensor (10) for measuring the static charge in the direction of travel of the conveying device (5), which is positioned in such a way that it neutralizes electrical charges of the workpieces (3) or tools (3).

5. System according to claim 3 or 4, wherein the discharge module is associated with an ionization electrode that neutralizes charges on the workpieces or tools.

6. System according to one or more of the preceding claims, wherein the inlet module (2) is assigned a sensor system (13), in particular for pressure and volume measurement, and wherein the higher-level control unit adjusts the pressure and air volume of the compressed air supplied to the cleaning module (3) so that the workpieces (6) or tools (6) have the required high degree of cleanliness after passing through the cleaning module (3).

7. Device according to one or more of the preceding claims, wherein the cleaning module (3) is associated with a speed-monitored, self-contained system with several centrifugal force-controlled rotary nozzles (16) and with a control / evaluation unit, wherein the speed of each of the rotary nozzles is continuously determined by means of an associated speed sensor, and wherein the control / evaluation unit generates a message when the speed of one of the rotary nozzles transmitted by one of the speed sensors deviates from a predetermined speed of the rotary nozzle.

8. Method for determining target values ​​for the parameters of the system described in claims 1-7, wherein the correctly set target values ​​ensure quality-assured cleaning of the workpieces or tools, wherein in a test phase the target values ​​for the transport speed of the conveying device and the target values ​​for the sensors of the individual modules are determined, and wherein the higher-level control system controls the system in regular cleaning operation on the basis of the target values ​​determined in the test phase.

9. Method according to claim 8, wherein the target values ​​are determined experimentally or via a digital simulation method during the test phase.

10. Method according to claim 8, wherein the optimal rotational speed for each of the rotary nozzles is determined during the test phase, and wherein the control / evaluation unit monitors the rotational speed of the individual rotary nozzles to the rotational speed determined during the test phase during regular operation.

11. Method according to at least one of claims 1-10, wherein all entered or determined data are recorded and documented by the superior control unit.

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