DETERMINATION AND CONTROL OF FORCE APPLIED DURING THE JOINING PROCESS

Abstract

A method for joining components, the method includes: - Positioning one arm of a soldering head next to at least one of the components; - Recording a first shear force value of at least one section of the arm that is positioned against the at least one component; - Determining a gravitational orientation of the soldering head or parts of the soldering head; - Calculating a second shear force value based on the first shear force value and the gravitational orientation of the soldering head or parts thereof; and - Repositioning at least one part of the soldering head relative to the at least one component in response to the second transverse force value that deviates from a target value.

Description

Field of the invention

[0001] The present disclosure generally relates to a process, such as a soldering process, for joining components. More particularly, but not exclusively, the present disclosure relates to systems and methods for determining and controlling the force applied to a workpiece or component during a soldering process, such as a laser soldering process. Background of the invention

[0002] Unless otherwise indicated herein, the materials described herein are not prior art to the claims of the present application and are not admitted as prior art by inclusion in this section.

[0003] Certain joining processes can be used to join different components or workpieces together. In brazing processes, for example, different components are joined using a filler material that is melted and flows between the different components or forms a bond between them. A special form of brazing is laser brazing (cf. DE 32 473 38 A1), in which a filler material is melted using a laser and flows between the different components or forms a bond between them. In one arrangement, the filler material may be a brazing wire whose melting point is lower than the melting point of the materials from which the components to be joined are made, although embodiments are also possible in which the filler material is a flux cored wire made of the same material as some or all of the components to be joined.The solder wire or filler wire can be positioned between a laser beam and the components to be joined and is movable along a seam of the components during a soldering process in order to fill or create a connection between the components with the material of the solder wire or filler wire while it is melted by the laser (cf. DE 10 2015 104 411 A1).

[0004] During the soldering process, the solder wire, the filler wire, or another part of a soldering head can be positioned against one or both components and exert a force on them before the solder wire or the filler wire is melted with the laser. For example, in a soldering process where a first component is placed over a second component, the solder wire can be positioned against the first component and exert a lateral force on it. In another variation, a first component can be positioned next to a second component, and the solder wire can be positioned in a groove between the components while a lateral force is applied to one of the components. For a successful soldering process, the solder wire is moved along the seam while a force on at least one of the components is maintained constant.During the soldering process, various complications can arise if the shear force exerted on the component deviates from a desired value or is not maintained constant or essentially constant. For example, the solder wire may not precisely follow the seam between the components, which can lead to an unsuccessful or undesirable connection of the components, an aesthetically undesirable joint, or both (see DE 20 009 886 U1).

[0005] Attempts to better control the lateral force acting on a component during a soldering operation to avoid these problems include the use of a lateral force sensor, which is designed to measure the lateral force acting on the component. However, certain forces acting on a soldering head that are not attributable to the positioning of the solder wire, filler wire, or any part of the soldering head against the component cannot be detected by the lateral force sensor. Therefore, the lateral force sensor may not accurately reflect the actual lateral force acting on the component. The soldering head can also be positioned in a number of different orientations when moving along the seam between components with complex geometries.Attempts to correct for these additional forces by measuring the shear force before a force is applied to the component do not take into account the effects on the shear force when the soldering head is positioned in different orientations and may also not provide the actual force applied to the component.

[0006] The granted European patent EP 1 742 759 B1 discloses a laser joining head assembly and a laser joining method for simultaneously performing joint tracking and seam inspection of a joint while the joining head assembly is in relative motion along the joint. The laser joining head assembly comprises integrated laser line projection means for tracking and integrated laser line projection means for inspection for projecting a laser line for tracking and a laser line for inspection onto the joint, respectively, thereby generating successive cross-sectional profiles of the joint and cross-sectional profiles of the seam. These profiles are processed to provide joint data and seam data, respectively, enabling joint tracking and seam inspection of the joint during motion.

[0007] The granted European patent EP 2 408 585 B1 relates to a brazing welding device comprising a means for distributing a filler metal over a region to be brazed, which is located between at least two elements to be joined by brazing, wherein the distributing means is connected to a melting means capable of melting the filler metal in the region to be brazed. Furthermore, the brazing device comprises at least one pressing wheel shaped and positioned such that it can exert pressure on the surface of one of the elements to be joined by means of the brazing device. The aforementioned pressing wheel is mounted movably relative to a pressure means. The invention is characterized in that the pressing wheel is arranged at a distance from the melting device along an axis corresponding to the direction of a brazing line. The invention also relates to a method using this device.

[0008] The subject matter claimed herein is not limited to implementations that address any disadvantages or that operate only in environments such as those described above. Rather, this background is provided only to illustrate an exemplary technology area in which some implementations described herein may be practiced. Summary of the invention

[0009] This summary is intended to present, in simplified form, a selection of embodiments described further below in the detailed description. This summary is not intended to identify key features or essential characteristics of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0010] One embodiment includes, in a method for connecting components, positioning a soldering head of a soldering device relative to the components. The soldering head includes at least a base body and an arm movable relative to the base body. The method also includes sensing a lateral force when a solder wire, a filler wire, or a guide finger extending from the soldering head is positioned against one of the components to provide a sensed lateral force value, determining the orientation of the soldering head relative to gravity to provide a particular orientation of the soldering head, and determining a position of the arm relative to the base body to provide a particular position of the arm relative to the base body.A corrected shear force value can be provided based on the detected shear force value, the determined orientation of the soldering head, and the determined angle of the arm relative to the base body. The method can also include repositioning at least a portion of the soldering head relative to the components if the shear force value deviates from a predetermined shear force target value.

[0011] In another embodiment, a system for connecting components includes a soldering head having a base, an arm coupled to and movable relative to the base, and a solder wire, filler wire, or guide finger extending from the soldering head. The system also includes a lateral force sensor configured to determine a lateral force when the solder wire, filler wire, or guide finger is applied against a component, an orientation sensor positioned on the arm and configured to determine an orientation of the soldering head relative to gravity, and an arm position sensor configured to determine a position of the arm relative to the base.A controller is connected to the lateral force sensor, the orientation sensor, and the arm position sensor, and the controller is configured to correct a lateral force value detected by the sensor based on an orientation of the soldering head determined by the orientation sensor and a position of the arm relative to the base body determined by the arm position sensor.

[0012] In another embodiment, a method comprises moving a soldering head or one or more components of the soldering head through a range of orientations in the absence of interaction of the soldering head or a component of the soldering head with a workpiece. The method also comprises sensing transverse force values ​​associated with the soldering head as the soldering head or one or more components thereof are moved through the range of orientations, and determining a correction value that should be applied to a transverse force value sensed during the joining process when the soldering head or one or more components thereof are in a particular configuration and a solder wire, a filler wire, or a guide finger extending from the soldering head is positioned against the workpiece and exerting a transverse force thereon.

[0013] Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The features and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the appended claims. These and other features of the present invention will be more fully apparent from the following description and the appended claims, or may be learned by practice of the invention as hereinafter pointed out. Short description of the drawings

[0014] To further clarify the above and other advantages and features of the present invention, a more detailed description of the invention will be made by reference to specific embodiments thereof illustrated in the accompanying drawings. It is understood that these drawings show only typical embodiments of the invention and are therefore not to be considered as limiting its scope. The invention will be further described and explained with additional specificity and detail through the use of the accompanying drawings: Fig. 1 is a schematic view of a laser soldering apparatus of the present disclosure. Fig. Figure 2A is a schematic diagram of a configuration for positioning a solder wire relative to components during a laser soldering process. Fig. Figure 2B is a perspective view of a configuration for a portion of the end of the arm. Fig. 2C-2E schematically show other configurations for positioning the solder wire relative to the components during a laser soldering process. Fig. 3A is a perspective view of a soldering head of a laser soldering apparatus. Fig. 3B is an enlarged perspective view of a portion of the Fig. 3A shown soldering head. Fig. 3C is a schematic view of a portion of a soldering head of the present disclosure. Fig. 4 is a schematic representation of a control process used in a laser soldering method of the present disclosure. Detailed description of the invention

[0015] Reference will now be made to the drawings to describe various aspects of embodiments of the invention. It should be understood that the drawings are diagrammatic and schematic representations of such example embodiments and are neither limiting nor necessarily drawn to scale.

[0016] The present disclosure generally relates to joining methods that can be used to join various components or workpieces. In some aspects, the disclosure relates to soldering, including laser soldering, as well as to techniques and systems for soldering. In particular, in some embodiments, a transverse force exerted by a portion of a soldering head on a workpiece is determined, taking into account various forces that may act on the soldering head. After the transverse force is determined in this manner, the soldering head or a portion thereof may be moved to adjust the transverse force exerted on the workpiece if the determined transverse force deviates from a predetermined value or a range of predetermined values ​​for the transverse force.Although the embodiments are described in the context of a brazing process, particularly a laser brazing process, it should be understood that the embodiments disclosed herein may also be used in other fields and / or operating environments where the functionality disclosed herein may be useful. For example, the subject matter described herein may also be applicable to other joining processes, such as welding, where the transverse force exerted on the workpiece must be controlled. Accordingly, the scope of the invention should not be construed as being limited to the exemplary implementations and operating environments disclosed herein.

[0017] Fig. 1 is a schematic view of a laser soldering apparatus 20 of the present disclosure. The apparatus 20 includes a soldering head 30 and may include other components described in Fig. 1 are not necessarily shown. For example, the laser soldering apparatus 20 may also include one or more components configured to move the soldering head 30, in whole or in part, relative to materials or components 10 and 12 that are joined together by the laser soldering apparatus 20. For example, the soldering head 30 may include a frame 34 coupled via a flange or other attachment 35 to one or more robotic arms 22 that can move the soldering head 30 in a variety of directions relative to the components 10 and 12. The laser soldering apparatus 20 may also include one or more components (not shown), such as a camera, laser rangefinders, or triangulation sensors, configured to assist in positioning the soldering head 30 relative to the components 10 and 12.As one skilled in the art will appreciate, the additional components that may be included in the laser soldering apparatus 20 described herein are not exhaustive, and the inclusion of various other components not expressly mentioned herein is also possible.

[0018] In the context of the present invention, a position or, in relation to the determination of a position, is also to be understood as a distance or the determination of a distance.

[0019] In the context of the present invention, the terms part and component or workpiece are used synonymously and refer to parts that are joined together by a joining process or method.

[0020] As in Fig. 1, the soldering head 30 is positioned relative to the components 10, 12 such that an end 41 of an arm 40 of the soldering head 30 abuts against at least one of the components 10, 12. This end 41 may be or comprise a portion of a solder wire, a filler wire, a guide finger, a needle, or other correspondingly shaped element, an extension, or even another portion on the arm 40 of the soldering head 30. As an example, Fig. 2A shows a solder wire 44 extending from a support member or wire feed nozzle 42 of the end 41. The solder wire 44 can trace the seam between the components 10, 12. As another example, Fig. 2B, a guide finger 43 at the end 41, which is inserted next to the wire feed nozzle 42, from which the solder wire (not shown) emerges to be melted by the laser beam LB. This guide finger 43 can be guided in the seam between the components if the solder wire is too soft. The transverse force sensor 46 would be located in Fig. 2B is located just above the end 41. The cylinder 54 is the connection to the wire feed cable 52. Other configurations are possible.

[0021] As in Fig. 1, the arm 40 can be moved in an articulated manner (ie, rotated relative to) a base body 32 of the soldering head 30. The soldering head 30 itself can be moved (displaced, rotated, etc.) in any direction with the aid of the robotics 22 of the device 20. During the soldering process, however, the head 30 is oriented such that the rotation axis of the arm 40 runs (more or less) parallel to the seam between the components 10, 12. In Fig. 1, this means that the axis of rotation of the arm 40 would lie along the Y-axis of the drawing, i.e. the axis along which the seam of the two components 10, 12 runs

[0022] To ensure that proper soldering can be achieved, a desired shear force (LF) is applied to at least one of the components (e.g. 12) during the soldering process. As described in Fig. 1, the transverse force (LF) to be controlled during the soldering process is the force between the end 41 and the component 12. This target transverse force (LF) is determined and maintained during the soldering process using sensors and calculations as disclosed herein. First, an initial value of the transverse force is measured using a force sensor 46 arranged on the arm 40. This force sensor 46 measures a force of the end 41 resting against the at least one component 12. However, this measurement of the initial transverse force by the sensor 46 includes influences from additional forces generated by other sources. In particular, the measured transverse force value is influenced by at least: (i) any stress resulting from the deformation of the wire feed cable 52 and (ii) the weight due to gravity of all elements connected below the transverse force sensor 46 (including the wire feed cable 52) if its orientation is not exactly vertical.In general, all elements below the lateral force sensor 46 can be referred to as the end 41 of the arm 40, as labeled in the figures. To correct for these other force quantities, the gravitational orientation of the base body 32 (or the arm 40) is determined, and the angle between the body 32 and the arm 40 is determined. For example, the gravitational orientation (G) of the arm 40 can be determined directly using an orientation sensor 48 arranged on the arm 40, and a relative position of the arm 40 can be determined with respect to the base body 32 using a rotary encoder 45 or another orientation sensor.Alternatively, the gravitational orientation (G) of the body 32 may be determined using an orientation sensor (not shown) on the base body 32, and the relative position of the arm 40 to the base body 32 from the rotary encoder 45 or other orientation sensor may be used to determine the gravitational orientation (G) of the arm 40.

[0023] A corrected transverse force value is then calculated, based on the measured transverse force value of the force sensor 46, the gravitational orientation (G) of the arm 40 or parts thereof, and the relative position of the arm 40 with respect to the base body 32 of the head 30. If the calculated transverse force value deviates from a target value, at least a portion of the soldering head 30 is then repositioned relative to the at least one component 12. For example, the arm 40 can be moved to correct the transverse force in the direction of the target value.

[0024] As in Fig. 1, the soldering head 30 may include a wire feeder 50 positioned on a frame 34 to which the base body 32 of the head 30 is coupled. A wire feeder cable 52 extends between the wire feeder 50 and a portion of the arm 40. During the soldering process, the wire feeder 50 feeds solder wire or the like through the feeder cable 52 to the end 41 adjacent to the laser process components 10 and 12. This configuration of the wire feeder 50 and the cable 52 may influence the lateral force detected during operation. For this purpose, a relative position between the arm 40 and the wire feeder 50 may also be detected.The calculated shear force value, as disclosed herein, may be based on the sensed shear force value, the determined gravitational orientation (G) of the soldering head 30 or portions thereof, the determined position of the arm 40 relative to the base body 32 of the head 30, and the determined relative positioning of the arm 40 and the wire feeder 50. Additional calculations may be performed to adjust the shear force value and may compensate for variable forces attributable to the mass of a portion of the soldering head 30 or the wire feed cable 52 connected to the arm 40 during movement of the soldering head 30. These and other features are described in more detail below.

[0025] In Fig. 1, the soldering head 30 is positioned relative to the components 10 and 12, with one component 12 positioned on (or overlapping) the other component 10 to create a seam. This overlapping arrangement is shown in Fig. 2A. In this example, the solder wire 44 extends from a support member 42 or a wire feed nozzle of the arm 40 and is pressed against one of the components 12 to achieve the correct position for soldering. The laser beam LB melts the solder wire 44. Once the solder wire is melted, the heated material flows between the overlapping portions of the components 10, 12 to create a solder joint or seam.

[0026] As can be seen, the soldering head 30 can be made of Fig. 1 relative to the components 10 and 12 and used to connect them when the components 10 and 12 are configured differently. Illustrations of some exemplary alternative configurations between the components 10 and 12 that can be connected by the soldering head 30 are shown in the Fig. 2C-2E.

[0027] In Fig. 2C, for example, one component 10 is positioned on top of another component 12, with the longitudinal axes of components 10 and 12 generally orthogonal to each other. This T-shaped geometry is typical for wire-welding or brazing applications for battery frames.

[0028] In Fig. 2D, components 10 and 12 have an arcuate section, and the sections of components 10 and 12 adjacent to the arcuate section are arranged side by side. This creates a groove or gap into which a filler material can be introduced to connect components 10 and 12.

[0029] In Fig. 2E, one component 10 is positioned adjacent to another component 12, with their surfaces generally flush with each other. A filler material may be positioned between components 10 and 12, over the surfaces of components 10 and 12, or both to form a butt joint.

[0030] The different configurations between components 10 and 12 as shown in the Fig. 2A and 2C-2E are not exhaustive with respect to the various configurations of components that can be connected to the soldering head 30. The following description is made in connection with the Fig. 2A for the sake of discussion. It will be appreciated that the subject matter disclosed herein may also be applied to and used in connection with other component configurations, including, but not limited to, those shown in the Fig. 2C-2E illustrated embodiments.

[0031] If you look at the soldering head 30 more closely, you will see Fig. 3A is a perspective view of a soldering head 30 for a laser soldering device (not shown), and Fig. 3B is an enlarged perspective view of a portion of the Fig. 3A. It also shows Fig. 3C is a schematic view of the enlarged portion of the soldering head 30 of the present disclosure. Not all components of the soldering head 30 are shown in each of the Fig. 3A-3C. In general, the soldering head 30 includes a base body 32, a frame 34 to which the base body 32 is coupled, and an arm 40 coupled to the base body 32. Fig. Figure 3A shows each of these components in addition to a wire feeder 50 and a wire feed cable 52. Fig. Figure 3B shows another view of portions of the head 30 with the arm 40 bent, with some features of the base body 32, the wire feed 50, the cable 52, and the like not shown for simplicity. Fig. Finally, Figure 3C is merely a schematic view of the elements of the head 30, not all features being shown, such as the base body 32, the wire feed 50, and the like.

[0032] In Fig. 3A, the head 30 is shown relative to exemplary components or workpieces 10, 12 to be joined. The soldering head 30 includes, among other features, the base body 32 and the frame 34 to which the base body 32 is coupled. The base body 32 can be movable relative to the frame 34 to assist in guiding the soldering head 30 along a seam between the components 10 and 12. However, the base body 32 can also be stationary relative to the frame 34.

[0033] The arm 40 is coupled to the base body 32, and a motor 36 on the base body 32 is configured to move the arm 40 relative to the base body 32 to enable proper positioning of an end 41 of the arm 40 relative to the components 10 and 12. A wire feeder 50 is coupled to the frame 34 and configured to feed a solder wire 44 through a wire feed cable 52. In other arrangements, a filler wire may be used, which may be fed from the wire feeder 50 through the wire feed cable 52. The wire 44 may extend from the wire feed cable 52 at the end 41 of the arm 40 and be positioned in the path of a laser beam LB.

[0034] As described here, end 41 represents the components of arm 40 that are connected to the rest of arm 40 via lateral force sensor 46, so that end 41 refers to the assembly connected below force sensor 46. The wire feeder cable 52 is attached to this end 41. The force sensor 46 measures all forces at end 41 that act laterally (i.e., perpendicular) to arm 40, including tension and weight of feeder cable 52. Fig. 1, the transverse force sensor 46 would measure the force along the X-axis.

[0035] During operation, the laser beam LB melts the wire 44 so that the material of the wire 44 can flow between the components 10 and 12 and connect them. Although in the Fig. 3A-3B is not visible, an extension or a leading finger (e.g. 43 in Fig. 2B), which may be in the form of a wire- or needle-shaped element (to name only a few non-limiting examples), extending from the end 41 of the arm 40.

[0036] In typical operations, only wire 44 is used as in Fig. 2A, the wire 44 is in contact with the components 10, 12 and is used for tracking along the seam. In some embodiments, however, the wire 44 is too soft for this, so that additional support by a fixed element, such as a guide finger, a needle, or other appropriately shaped element extension, is required. This fixed element, such as the guide fingers 43 in Fig. 2B, is also connected to the end of the arm 41. In this case, the process can automatically control the force between the fixed element and at least one of the components 10, 12 to track and move the soldering head 30 along a seam between the components 10 and 12 with a controlled force.

[0037] When the end 41 of the arm 40 is positioned relative to the components 10, 12 as shown in Fig. 3A, the wire 44 can be welded during a laser soldering process in the Fig. 2A against one of the components 10, 12 and exert a lateral force thereon. Alternatively, if present, a fixed element (e.g., a guide finger 43) extending from the end 41 of the arm 40 can be positioned during a laser soldering process in the direction shown in Fig. 2A, against one of the components 10, 12 and exert a lateral force on it.

[0038] As in Fig. 3A, the soldering head 30 includes a lateral force sensor 46 positioned on the arm 40. The lateral force sensor 46 is disposed between the end 41 and the remainder of the arm 40. The lateral force sensor 46 is configured to measure or determine a value for the lateral force on the end 41. In some arrangements, the lateral force that the end 41 (e.g., the solder wire 44, the filler wire, or the guide finger 43) exerts on the component 12 can be determined from data associated with the motor 36 that moves the arm 40 to position the end 41 (e.g., the solder wire 44, the filler wire, or the guide finger 43) against the component 12 and apply a lateral force thereto. For example, the electrical current data of the motor 36 could be related to the force exerted on the component 12, as, for example, For example, it can be assumed that a higher intensity of the electric current used by the motor 36 corresponds to a higher transverse force exerted on the component 12.In this case, the force acting on the entire arm 40 can be derived from the motor data. However, a disadvantage is that the arm 40 is very heavy, so two relatively large numbers must be subtracted from the calculations to obtain the relatively small transverse force acting on components 10 and 12.

[0039] However, the transverse force value determined by the transverse force sensor 46 may be influenced by forces resulting from the positioning of the end 41 (e.g., the solder wire 44, the filler wire, or the guide finger 43) against the component 12, in addition to the forces resulting from the positioning of the end 41 (e.g., the solder wire 44, the filler wire, or the guide finger 43). For example, some components of the soldering head 30 are located below the transverse force sensor 46. Therefore, gravitational forces can variably influence the transverse force value detected by the transverse force sensor 46 if the orientation of all or part of the soldering head 30 changes during a laser soldering process. In other words, depending on the shape and contour of the components 10 and 12, all or part of the soldering head 30 moves relative to the components 10 and 12 to ensure that the soldering head 30 is properly guided along the seam between the components 10 and 12, so changes in the gravitational force may occur.In addition, the wire feed cable 52 is coupled to the end 41 of the arm 40 and can itself exert a variable force on the end 41 of the arm 40 when the arm 40 is moved relative to the base body 32.

[0040] The soldering head 30 also includes a number of additional components structured to determine various operating aspects of the soldering head 30, and the determinations made by these components can be used to correct or adjust a lateral force value sensed by the lateral force sensor 46. For example, the soldering head 30 includes an orientation sensor 48, which is located, for example, on the arm 40. The orientation sensor 48 is configured to determine an orientation of the arm 40 relative to the direction of the gravitational forces acting on the soldering head 30. While the orientation sensor 48 is positioned on the arm 40 in the illustrated arrangement, the orientation sensor 48 can also be positioned on the base body 32 or on the frame 34, to name a few possibilities.As explained below for such a possibility, the rotary encoder 45 can be used to convert the measured value of an orientation sensor on the body 32 or frame 34 into an actual orientation of the arm 40 with respect to gravity.

[0041] In addition to this orientation sensor 48, the soldering head 30 may include one or more additional orientation sensors. In arrangements where more than one orientation sensor is present, an average of the orientation values ​​of the soldering head 30 from each of the orientation sensors may be detected or determined, or the additional sensor(s) may be used to detect potential anomalies related to a dedicated orientation sensor using a specific orientation value.

[0042] In the illustrated arrangement, the orientation sensor 48 can determine the orientation of the arm 40 over a range of orientations relative to gravity. In this way, the gravity acting on the end 41 of the arm 40 below the shear force sensor 46 in a range of process-relevant orientations can be taken into account when correcting or adjusting the shear force value determined by the shear force sensor 46 during a laser soldering process. Further details on this can be found below.

[0043] In addition to or instead of the orientation sensor 48, other techniques for determining the orientation of the arm 40 over a range of orientations relative to gravity may be used. For example, if the soldering head 30 is coupled to one or more robotic arms that can move the soldering head 30 in a variety of directions, the control system for the robotic arms may provide relevant data from which the orientation of the soldering head 30 can be determined. As another example, data relating to the time-varying orientation of the soldering head may be programmed or stored into the control system 80 for the soldering head, and a current orientation of the soldering head 30 may be correlated from this data. Arrangements are also possible in which the orientation of the soldering head 30 relative to gravity remains fixed during a joining operation.In these arrangements, the orientation of the soldering head 30 may be provided by the orientation sensor 48, or it may be determined or provided from orientation information corresponding to the fixed orientation of the soldering head 30, which may be programmed or stored in the controller for the soldering head 30.

[0044] As in the Fig. 3A-3C, the soldering head 30 also includes a Z-position sensor 47 positioned on the arm 40 and configured to detect the positioning of the end 41 of the arm 40 along an axis (B: Fig. 3B) of arm 40. More specifically, during a laser soldering process, the movement of solder head 30 relative to components 10 and 12 will change, and the relative positioning between arm 40 and its end 41 may change. As this occurs, the tension on wire feed cable 52 may change, as may the forces exerted by wire feed cable 52 on end 41 of arm 40. Accordingly, Z-position sensor 47 is configured to determine the relative positioning between arm 40 and its end 41 over a range of orientations. This relative positioning can be used to determine any additional force exerted by solder wire feed cable 52 on end 41 of arm 40, and the additional force can be accounted for when correcting or adjusting the shear force value determined by shear force sensor 46 during a laser soldering operation, as described in more detail below.

[0045] The soldering head 30 also includes one or more sensors configured to determine the relative positioning between the arm 40 and the base body 32. In the example shown, an angle sensor or rotary encoder (45: Fig. 3B-3C) to determine the relative angular positioning between the arm 40 and the base body 32. As shown in Fig. 3B, the measured angle may be representative of an angle C between an axis B of the arm 40 and an axis A of the base body 32. The arm 40 may be rotated relative to the base body 32 as the soldering head 30 is moved relative to the components 10 and 12 to adjust the lateral force exerted by the end 41 (e.g., the solder wire 44, the filler wire, or the tracking finger 43) on one of the components 10 or 12, or on both components, so that the end 41 can be correctly positioned along a seam between the components 10 and 12, or both.

[0046] When the arm 40 is moved relative to the base body 32, it is also moved relative to the wire feed device 50. This can change the tension of the wire feed cable 52 and thus also the forces exerted by the wire feed cable 52 on the end 41 of the arm 40. Accordingly, the rotary encoder 45 is configured to determine the relative positioning between the arm 40 and the base body 32 over a range of process-relevant orientations, so that any additional force exerted by the wire feed cable 52 on the end 41 of the arm 40 can be accounted for in a correction or adjustment of the shear force value determined by the shear force sensor 46 during a laser soldering process, as described in more detail below.

[0047] In addition to or instead of the rotary encoder 45 for determining the relative angular positioning between the arm 40 and the base body 32, the angular positioning between the arm 40 and the base body 32 can, in some arrangements, be determined by a first orientation sensor (e.g., 48; Fig. 3A, Fig. 3C) positioned on arm 40 and a second orientation sensor (not shown) positioned on base 32. In this arrangement, changes in orientation determined by the first and second orientation sensors can be used to determine the angular positioning between arm 40 and base 32. In still other arrangements, arm 40 can translate along or relative to base 32 in addition to, or instead of, rotating relative to base 32. In these arrangements, a position sensor (not shown) can be provided on arm 40 to determine the relative positioning between arm 40 and base 32 as arm 40 is translated relative to base 32.

[0048] As in Fig. 3C, the laser beam LB is guided by the laser processing head 30 via a series of optical elements to the components 10, 12. An optical fiber 60 guides the laser beam LB to the head 30, and a series of elements, including a collimator 61, reflectors 62 and 63, and a focusing lens 64, guide the laser beam LB out of the head 30 via a cover slide 65 to the components 10, 12 to be joined. As previously mentioned, the motor 36 can pivot the arm 40 relative to the base body 32, and the rotary encoder 45 can measure the pivot angle. The orientation sensor 48 can be arranged on the arm 40 to measure the orientation relative to gravity, and the lateral force sensor 46 can be arranged on the arm 40 to measure the lateral force of the end 41 positioned against at least one of the components 10, 12, as disclosed herein. The Z position sensor 47 determines the relative distance along the axis B of the arm 40 relative to the components 10, 12.

[0049] As in Fig. 3C, a biasing element 49 may be used so that the end 41 is extended along the axis B until it makes contact with at least one of the components 10, 12. The position sensor 47 measures how far the end 41 is extended. The end 41 is moved together with the focusing lens 64 to change the focal point of the laser beam LB based on the distance of the arm from the components 10, 12. As previously mentioned, the wire feeder 50 can guide the solder wire 44 or the like through the wire feed cable 52 to the end 41 of the arm 40, which is used to follow the seam of the components 10, 12, where the laser beam LB is applied to perform the soldering.

[0050] As in Fig. 3C, one or more control units or controllers 80 may be used to perform the techniques disclosed herein. The one or more control units 80 are in communication with the various sensors, including the lateral force sensor 46, the rotary encoder 45, the Z-position sensor 47, and the orientation sensor 48. The one or more controllers 80 may be a separate control unit from other control units of the soldering head 30 or may be integrated into existing equipment. In any event, the one or more controllers 80 may utilize any conventional data processing, storage, communication interfaces, and the like suitable for a given implementation.

[0051] Fig. 4 shows a schematic representation of a non-limiting control process, technique, or method 100 for operating the soldering head 30. In the method 100, a force controller 102 is structured to control the actuation or operation of the motor 36 to control the position of the arm 40 relative to a rotational axis (R: Fig.3A-3C) and to maintain the application of a constant or substantially constant force to the respective component 10, 12 by the end 41 (e.g., solder wire 44, filler wire, or the tracking finger 43). The lateral force sensor 46 determines a lateral force value in a specific position of the arm 40 relative to the base body 32 when the end 41 (solder wire 44, filler wire, or the tracking finger 43) rests against the respective component 10 and exerts a lateral force on it. In addition, the rotary encoder 45 measures and determines a relative angular position between the arm 40 and the base body 32, and the orientation sensor 48 determines the orientation of the arm 40. Due to the preload 49, the end 41 touches at least one component 10 or 12 along the axis. The Z-position sensor 47 measures how far the end 41 is "extended" along the axis.

[0052] The determined shear force value, the determined relative angular position between the arm 40 and the base body (32), the determined orientation of the arm 40, and the determined relative position of the end (41) of the arm 40 are all provided to a force correction algorithm 106. This force correction controller 106 is configured to correct or adjust the determined shear force value to provide a correct or adjusted shear force value. Likewise, the shear force value provided by the force correction controller 106 takes into account the variable forces acting on the end (41) of the arm 40 of the soldering head 30, in addition to the forces resulting from the positioning of the end (41) (solder wire 44, filler wire, or the tracking finger 43) against the component 12. This is done to obtain a shear force value that more accurately reflects the actual force acting on the component 12.

[0053] The force correction controller 106 may also be configured to determine whether the shear force value it provides deviates from a target or specified shear force value or is outside a range of acceptable shear force values ​​that should be applied to a component 12 during the laser soldering process. If the shear force value provided by the force correction controller 106 does not require adjustment, the method 100 may continue without any adjustment by the force controller 102 to the motor 36 and thus to the arm 40. As can be seen, the control loop 100 continuously corrects the force.

[0054] However, if the lateral force value provided by force correction controller 106 needs to be adjusted, force correction controller 106 can provide a corresponding indication to force controller 102, which in turn can control motor 36 accordingly to adjust the positioning of arm 40 to change the amount of force applied to component 12 and maintain the application of a constant or substantially constant force to component 12. In one embodiment, method 100 is adapted to maintain the lateral force applied to the component within 0.1 N of a target or predetermined value, although other variations are possible.In addition to or instead of adjusting the positioning of the arm 40, the amount of force exerted on the component 10 can be changed by shifting the positioning of the soldering head 30 relative to the components 10 and 12, although other variations for effecting adjustment of the amount of transverse force exerted on the components 10 and 12 are also possible.

[0055] In one non-limiting arrangement, the force correction controller 106 may be programmed with a number of transverse force values ​​previously recorded by the transverse force sensor 46 when no transverse force is applied to the component 10 by the end (41) (e.g., solder wire 44, filler wire, or the tracking finger 43) while the arm 40 is moved through a process-relevant range of orientations of the arm 40, positions of the arm 40 relative to the wire feed (50), and angles of the arm 40 relative to the base body (32). For each recorded transverse force value, the orientation of the arm 40, the position of the arm 40 relative to the wire feed (50), and the angle of the arm 40 relative to the base body (32) may also be recorded and correlated with a corresponding transverse force value. In this case, the orientation of the head 30 would also need to be varied within the process-relevant range.The same can be considered for the movement of end 41 along axis B. In other words, this calibration may need to go through all process-relevant combinations of angles, orientations, and perhaps also Z positions.

[0056] During execution of the method 100 in this arrangement, the force correction controller 106 may, for example, correlate the determined relative angular position between the arm 40 and the base body 32, the determined orientation of the arm 40, and the determined relative position of the end 41 of the arm 40 relative to the components 10 and 12 and the frame 34 with one of the recorded lateral force values ​​to identify a correction or adjustment value that should be applied to the lateral force value sensed by the lateral force sensor 46. In one arrangement, the force correction controller 106 provides the lateral force value by subtracting the recorded lateral force value identified by the force correction controller 106 during calibration from the lateral force value sensed by the lateral force sensor 46. However, other variations are also possible.

[0057] In the event that there is no recorded lateral force value corresponding to a given set of parameters for the determined relative angular position between the arm 40 and the base body 32, the determined orientation of the arm 40, and the determined relative position of the end 41 of the arm 40 relative to the components 10 and 12 and the frame 34, the force correction controller 106 may also be configured to calculate and provide the lateral force value by interpolation or extrapolation from the other recorded lateral force values.

[0058] As described above, the lateral force value determined by the lateral force sensor 46 is corrected or adjusted based on (i) the determined relative angular position between the arm 40 and the base body 32, (ii) the determined orientation of the arm 40 with respect to gravity, and (iii) the determined relative position of the end 41 of the arm 40 relative to the components 10 and 12 and the frame 34. However, there are arrangements in which the lateral force value determined by the lateral force sensor 46 is corrected or adjusted based on: (i) the determined relative angular position between the arm 40 and the base body 32, and (ii) the determined orientation of the arm 40 or the base body 32. Other combinations are also possible.

[0059] Although not discussed previously, it should be understood that the force controller 102, the force correction controller 106, or both may be part of a processing subsystem constructed with controllers, modules, sensors, actuators, communication links, and other devices known in the art for performing the operations described herein. The force controller 102, the force correction controller 106, or both may be a single device or a distributed device, and the functions of the force controller 102, the force correction controller 106, or both may be performed by hardware or software. All instructions and information may be provided in alternative forms, some information may be omitted in certain embodiments, and additional information may be present in certain embodiments.Information can be interpreted from sensor inputs, from data connections, from parameters on a computer-readable storage medium, or by other technically understandable information gathering devices.

[0060] In certain embodiments, the force controller 102, the force correction controller 106, or both include one or more modules structured to functionally perform their operations, emphasizing the structural independence of the aspects of the force controller 102 or the force correction controller 106 and illustrating a grouping of operations and responsibilities of the force controller 102 or the force correction controller 106. Other groupings that perform similar overall operations are understood within the scope of the present disclosure. Modules may be implemented in hardware and / or software on a computer-readable medium, and modules may be distributed across various hardware or software components.

[0061] Finally, the techniques according to the present disclosure can be used to calibrate the operation of the soldering head 30 to account for lateral force corrections. For the calibration process, the soldering head 30 or one or more components (e.g., the arm 40) of the soldering head 30 are moved through a range of configurations in the absence of interaction of the soldering head 30 or a component of the soldering head 30 with a workpiece 10, 12 to be joined. In particular, and in the absence of interaction with a workpiece, the motor 36 is operated in the calibration process to actively move at least the arm 40 through a process-relevant range of orientations (i.e., a range of orientations that the arm 40 would have during a soldering operation or could be moved during a soldering operation). The lateral force values ​​are acquired in association with the soldering head 30 as the arm 40 is moved through the range of configurations.A correction value is then determined which should be applied to a transverse force value detected during the joining process when the soldering head 30 or one or more components (40) thereof are actually moved in a certain configuration and when a solder wire, filler wire or tracking finger extending from the soldering head 30 is positioned against the workpiece 10 or 2 or both and exerts a transverse force thereon.

[0062] During calibration, the orientation of the soldering head 30 relative to gravity may be determined to provide a specific orientation of the soldering head 30; and a position of an arm 40 of the soldering head 30 may be determined relative to a base body 32 of the soldering head 30 to provide a specific position of the arm relative to the base body. Additionally, a relative positioning between the arm 40 and the wire feeder 50, which is positioned on a frame to which the base body 32 is coupled, may be determined to provide a specific relative position between the arm 40 and the wire feeder 50. In this way, the determination of the correction value, as disclosed herein, may be based on the determined orientation of the soldering head 30, the determined position of the arm 40 relative to the base body 32, and the determined relative position between the arm 40 and the wire feeder 50.

[0063] Unless certain arrangements described herein are mutually exclusive, the various implementations described herein may be combined with one another to enhance system functionality or to create complementary functions. Likewise, aspects of the implementations may be implemented in standalone arrangements. Therefore, the above description has been given only by way of example, and modifications in detail may be made within the scope of the present invention.

[0064] With respect to the use of plural or singular terms herein, those skilled in the art may translate from the plural to the singular or from the singular to the plural as appropriate to the context or application. The various singular / plural permutations may be expressly recited herein for clarity. Reference to an element in the singular is not intended to mean "one and only one" unless specifically noted, but rather "one or more." Furthermore, nothing disclosed herein is intended to be dedicated to the public, regardless of whether such disclosure is expressly relied upon in the above description.

[0065] In general, the terms used here, and particularly in the appended claims (e.g., in the bodies of the appended claims), should be understood as "open" terms (e.g., the term "including" should be interpreted as "including, but not limited to," the term "having" as "having at least," the term "comprises" as "comprises, but is not limited to," etc.). Moreover, where a convention analogous to "at least one of A, B, and C, etc." is used, such a construction is generally intended in the sense in which a person skilled in the art would understand the convention (e.g., "a system having at least one of A, B, and C" would include, but is not limited to, systems comprising A alone, B alone, C alone, A and B together, A and C together, B and C together, or A, B, and C together, etc.).Likewise, a phrase containing two or more alternative terms, whether in the description, claims, or drawings, should be understood to include one of the terms, one of the terms, or both of the terms. For example, the phrase "A or B" is understood to include the possibilities "A" or "B" or "A and B."

[0066] The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is therefore indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalence of the claims are intended to be embraced within their scope.

Claims

[1] A method of joining components, the method comprising: - Positioning an arm of a soldering head next to at least one of the components; - detecting a first transverse force value of at least a portion of the arm positioned against the at least one component; - Determining a gravitational orientation of the soldering head or parts of the soldering head; - Calculating a second transverse force value based on the first transverse force value and the gravitational orientation of the soldering head or parts thereof; and - Repositioning at least a portion of the soldering head relative to the at least one component in response to the second transverse force value deviating from a target value. [2] The method of claim 1, wherein positioning the arm of the soldering head adjacent the at least one component comprises positioning an element of the arm against the at least one component, the element comprising a portion of a wire used in the soldering process, a surface of the arm, or a guide finger extending from the arm. [3] The method of claim 1 or 2, wherein determining the gravitational orientation of the soldering head or parts thereof comprises using an orientation sensor arranged on the soldering head or parts thereof. [4] The method according to any one of claims 1 to 3, wherein detecting the first lateral force value comprises detecting it with a lateral force sensor arranged on the arm. [5] The method of any one of claims 1 to 3, wherein detecting the first lateral force value comprises detecting with data from a motor coupled to the arm. [6] The method of any one of claims 1 to 5, wherein repositioning at least the portion of the soldering head comprises moving the arm relative to the base body. [7] The method according to any one of claims 1 to 6, further comprising: - feeding a wire from a wire feeder positioned on the soldering head; and - Feeding the wire through a wire feed cable that extends between the wire feeder and part of the arm. [8] The method of claim 7, further comprising: - Applying a laser from the soldering head to the wire fed to the part of the arm; and - Moving the soldering head along a connection between components. [9] The method according to any one of claims 1 to 8, further comprising determining a first relative position of the arm with respect to a base body of the soldering head that supports the arm and using this first relative position in the calculation of the second transverse force value. [10] The method according to claim 9, wherein determining the first relative position of the arm with respect to the base body comprises measuring the first relative position with a rotary encoder or two orientation sensors, a first of which is arranged on the base body or at least a part fixedly connected thereto and a second of which is arranged on the arm. [11] The method of any one of claims 1 to 10, further comprising determining a second relative position between the arm and its end, and using this second relative position in the calculation of the second lateral force value. [12] The method of any one of claims 1 to 11, wherein determining the second transverse force value comprises compensating for variable forces attributable to the mass of a portion of the soldering head or a wire feed cable coupled to the arm during movement of the soldering head, or both. [13] A system for connecting components, comprising: - a soldering head consisting of at least a base body and an arm, wherein the arm is coupled to the base body and movable relative thereto; - a lateral force sensor configured to determine a first lateral force when a portion of the arm is applied against at least one of the components or when forces exerted by gravity or a wire feed cable are applied to the end of the arm; - an orientation sensor configured to determine an orientation of the soldering head or parts thereof relative to gravity; - a controller connected to the lateral force sensor and the orientation sensor, the controller being configured to - calculating a second transverse force value based on the first transverse force value and the orientation of the soldering head or parts thereof relative to gravity; and - Repositioning at least a portion of the soldering head relative to the at least one component in response to the second transverse force value deviating from a target value. [14] The system of claim 13, wherein the soldering head comprises: - a wire feed coupled to the base body; and - the wire feed cable that extends between the wire feeder and part of the arm. [15] The system of claim 13 or 14, further comprising a second position sensor configured to determine a second relative position between the arm and its end and using that second relative position in calculating the second lateral force value. [16] The system according to any one of claims 13 to 15, comprising a first position sensor configured to determine a first position of the arm relative to the base body and using this first relative position in the calculation of the second lateral force value [17] The system of any one of claims 13 to 16, wherein the controller is configured to adjust the first transverse force value sensed by the force sensor to compensate for variable forces on the soldering head as the soldering head moves through a range of orientations and / or the arm moves through a range of positions during a soldering operation. [18] A method of connecting components, comprising: - Changing the orientation of an arm of a soldering head by operating a motor coupled to the arm and / or changing the orientation of the soldering head through a range of orientations in the absence of interaction with components to be joined; - Recording of first shear force values ​​in combination with the orientations; and - determining corrections for the acquired first shear force values ​​that are correlated with the orientations; and - Apply the determined corrections to obtain second shear force values ​​for orientations that occur during component joining. - Repositioning at least a portion of the soldering head relative to at least one of the components to be joined in response to the second transverse force value deviating from a target value. [19] The method of claim 18, further comprising using a second position sensor configured to determine a second relative position between the arm and its end and determining corrections for the sensed first lateral force values ​​correlated with the second relative position.

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