Pressing system, laser-joining system, and method

Abstract

A pressing system for a laser joining system for pressing together parts to be joined (storage cell, base plate) in the area of a joining point, includes a receptacle for accommodating the parts to be joined, a pressing element for locally pressing together the parts to be joined, in the area of the joining point, and a positioning system for the relative positioning of the pressing element and the receptacle and for pressing together the parts to be joined, during the joining process. The positioning system includes a parallel positioning device for the relative positioning of the receptacle and the pressing element in parallel to a plane (E), and an oblique positioning device for the relative positioning of the pressing element and the receptacle obliquely, in particular transversely, with respect to the plane (E) and for pressing together the parts to be joined, during the joining process.

Claims

1. A pressing system for a laser joining system for pressing together parts to be joined in the area of a joining point, the parts to be joined comprising a storage cell and a base plate, the pressing system comprising a receptacle for accommodating the parts to be joined, at least two mechanical a pressing elements for locally pressing together the parts to be joined, in the area of joining points associated with each of the pressing elements, a positioning system for the relative positioning of the pressing elements and the receptacle and for pressing together the parts to be joined, during the joining process, the positioning system comprising at least two parallel positioning devices, each one of the parallel positioning devices comprising a drive configured for the relative positioning of the receptacle and the pressing element in parallel to a plane (E), and at least two an oblique positioning devices, each one of the oblique positioning devices comprising a drive configured for the relative positioning of the pressing elements and the receptacle obliquely, with respect to the plane (E) and for pressing together the parts to be joined, during the joining process, wherein a first one of the pressing elements is configured to press together two parts to be joined at a first one of the joining points, while a second one of the pressing elements is displaced to a second one of the joining points, wherein during the joining process at the first joining point, the second pressing element is brought into an area of the second joining point, so that the parts to be joined can be subsequently pressed together and joined at the second joining point.

2. The pressing system according to claim 1, wherein at least one of said parallel positioning devices comprises a scissors mechanism and/or a linear drive.

3. The pressing system according to claim 1, wherein at least one of said pressing elements comprises a sensor comprising at least one of the following: a position sensor for localizing a joining point, a temperature sensor, and a force sensor for measuring the contact pressure.

4. The pressing system according to claim 1, wherein at least one of said pressing elements comprises a temperature-control element for the temperature control of at least one area of the joining point.

5. The pressing system according to claim 1, wherein at least one of said pressing elements has a passage region for the passage of a joining laser beam.

6. A laser joining system for joining parts to be joined in the area of a joining point, comprising: a joining laser generating a joining laser beam, and a pressing system according to claim 1.

7. The laser joining system according to claim 6, wherein the joining laser comprises a beam positioning system that is displaceable in parallel to the plane (E), and/or comprises a scanner for controlling the joining laser beam.

8. The laser joining system according to claim 6, wherein the laser joining system (1) comprises a focal position adjusting device for adjusting a focal position of the joining laser beam.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Exemplary embodiments and variants of the invention are represented in the schematic drawing and are described in greater detail in the description that follows.

(2) In the drawings:

(3) FIG. 1 shows a schematic representation of a top view of the laser joining system; and

(4) FIG. 2 shows the method according to the invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(5) The design and the mode of operation of a laser joining system and of the method according to the invention are to be described in greater detail, by way of example, on the basis of the production of a current accumulator.

(6) For this purpose, FIG. 1 shows a laser joining system 1 comprising a storage cell 2 which is to be laser-joined, in particular laser-welded, onto a base plate 3.

(7) The laser joining system 1 comprises a receptacle 4. In the receptacle 4, the base plate 3 and, therebelow, (not visible in the top view from FIG. 1 and therefore represented merely using dashed lines), the storage cell 2 are disposed at a first joining point 5. It is understood that a plurality of storage cells are disposed under the base plate 3 at a plurality of joining points, in order to attain a high storage capacity of the current accumulator, and the storage cells are to be joined with the base plate 3. In particular, a second joining point 5a and a third joining point 5b are represented, by way of example.

(8) The laser joining system 1 comprises a pressing system 6. The pressing system 6 comprises two pressing elements 7, 7. Each of the pressing elements 7, 7 is guided by a parallel positioning device 8, 8 and an oblique positioning device 9, 9.

(9) In addition, it is apparent that a joining laser 10 is displaceable within the laser joining system 1 along a laser slide rail 11.

(10) In one alternative embodiment, the joining laser 10 is displaceable both in a longitudinal direction as well as a transverse direction by means of an at least two-dimensional positioning device, in order to therefore allow for an even larger displacement area.

(11) The joining laser 10 generates a joining laser beam 12 which, in the state depicted in FIG. 1, is directed toward the first joining point 5.

(12) The parallel positioning devices 8, 8 are used for the relative positioning of the receptacle 4 and the pressing elements 7 and 7, respectively, in parallel to the plane E extending along the base plate 3.

(13) A z-direction is marked in FIG. 1 perpendicular to the plane E spanned by the base plate 3.

(14) The oblique positioning devices 9 and 9 are configured for carrying out the relative positioning of the pressing elements 7 and 7, respectively, and the receptacle 4 obliquely, in particular transversely, with respect to the plane E, i.e., along the z-direction. Moreover, the oblique positioning devices 9, 9 are used for pressing together the parts to be joined, in particular the base plate 3 and the storage cell 2, during the joining process.

(15) Each of the parallel positioning devices 8, 8 comprises slide rails 13, 13, respectively. Linear drives 14, 14, 14, 14 are displaceably disposed on the slide rails 13, 13. The slide rails 13, 13, together with the linear drives 14, 14, 14, 14, form linear motors, by way of which the scissors mechanisms 15, 15 are controlled.

(16) The slide rails 13, 13 are disposed on both sides of the receptacle 4. It is therefore possible to displace the pressing elements 7, 7 so far to the side that the area of the receptacle is freely accessible from above, and so the parts to be joined can be positioned on the receptacle 4 or can be removed, e.g., by means of a gripper.

(17) The oblique positioning devices 9, 9 are disposed at the articulation points of the scissors mechanisms 15, 15. The oblique positioning devices 9, 9 are both formed as pneumatic cylinders. By means of the pneumatic cylinders, the pressing elements 7, 7 can be displaced along the z-direction. In particular, the pressing elements 7, 7 can therefore be pressed against the base plate 3.

(18) In the state of the laser joining system 1 depicted in FIG. 1, the base plate 3 and the storage cell 2 can be pressed together locally at the first joining point 5 by means of the pressing element 7, by way of the pneumatic cylinder being actuated.

(19) The position of the pressing element 7 or 7 can be determined by means of a position sensor of the oblique positioning element 9 or 9, respectively.

(20) Moreover, the joining laser 10 comprises a scanner for controlling the joining laser beam 12. The scanner is used in this case for rapidly deflecting the joining laser beam 12 within the beam area 16. If the joining laser 10 is therefore displaced along its laser slide rail 11, the beam area 16 is also displaced. The beam area 16 can therefore pass over the work area 17 of the laser joining system 1.

(21) Moreover, the joining laser 10 comprises a focal position adjusting device. The focal position adjusting device is used for adjusting the focal position of the joining laser beam 12.

(22) Moreover, the pressing elements 7, 7 also comprise temperature-control elements. The temperature-control elements are formed, in particular, as cooling elements. They are used for cooling the area surrounding a joining point 5, 5a, 5b by means of the pressing elements 7, 7 during the laser joining.

(23) The contact area or pressure point of the pressing elements 7, 7 is annular, and so a passage region results, through which the joining laser beam 12 can pass.

(24) FIG. 2 schematically shows the method according to the invention for joining parts to be joined.

(25) The method is described in greater detail in the following on the basis of the laser joining system 1, with reference to FIG. 2 and on the basis of the exemplary case of joining the base plate 3 to the storage cell 2 or a plurality of similar storage cells 2.

(26) In a first step 101, the parts to be joined are accommodated in the receptacle 4 of the pressing system 6 of the laser joining system 1. For this purpose, the storage cells 2 are initially placed next to one another in a matrix form within the receptacle 4. The base plate 3 is subsequently placed onto the storage cells 2 and is held in the receptacle 4 by means of a holding device of the receptacle 4.

(27) In a second method step 102, a relative positioning of the pressing element 7 and the receptacle 4 with respect to the first joining point 5 takes place by means of the parallel positioning device 8. This takes place, in particular, by means of the displacement of the linear drives 14, 14, by way of which the scissors mechanism 15 and, therefore, the oblique positioning device 9 and the pressing element 7 are displaced within the work area 17. The state represented in FIG. 1 corresponds to the end state of this method step. It is apparent that the pressing element 7 is positioned above the first joining point 5 in the z-direction.

(28) In a subsequent method step 103, the parts to be joined, i.e., the base plate 3 and the storage cell 2, which are disposed in the area of the first joining point 5, are pressed together locally. For this purpose, the oblique positioning device 9 is actuated and the pressing element 7 is moved in the z-direction toward the base plate 3 until it presses the base plate 3 against the storage cell 2. The pressing element 7 must be moved further or less further in the z-direction depending on the tolerance or the dimension of the storage cell 2. The end position of the pressing element 7 and, therefore, the position of the first joining point 5 under contact pressure are detected by means of the position sensor of the pressing element 7.

(29) On the basis of the position sensor information, the movement is monitored and is readjusted, if necessary.

(30) In the subsequent method step 104, the storage cell 2 is now joined with the base plate 3 at the first joining point by means of the joining laser beam 12. In order to improve the joining result, the focal position of the joining laser beam 12 is matched to the detected position.

(31) The second pressing element 7 is already located in the area of the second joining point 5a.

(32) According to the method, during the remaining time, while joining is carried out at the first joining point 5, the pressing element 7 is lowered in the z-direction at the second joining point 5a, in order to press the base plate 3 locally against the storage cell that is located thereunder, at this point as well. Immediately after completion of the joining at the first joining point 5, the joining laser beam 12 can therefore be deflected to the second joining point 5a in order to join, at this point, the two parts to be joined.

(33) As soon as joining is completed at the second joining point 5a by means of the joining laser beam 12, the first pressing element 7 is raised again counter to the z-direction and is moved to the third joining point 5b by means of the parallel positioning device 8. The duration of the joining carried out at the second joining point 5a is therefore now utilized for moving the first pressing element 7 to the third joining point 5b.

(34) The parts to be joined are therefore joined in succession at the joining points within the beam area 16 by each of the joining points being moved to in succession, by means of the pressing elements 7, 7, and the parts to be joined being pressed together only locally at these joining points.

(35) In this case, a predefined pattern or a predefined sequence of the joining points can be followed. In particular, it is provided in this variant of the method to move to the joining points row-by-row, i.e., transversely with respect to the laser slide rail 11. In one further variant it is provided to move to the joining points column-by-column or along a wavy line.

(36) As soon as all joining points within the beam area 16 have been finally processed, the joining laser 10 is displaced along the laser slide rail 11 and, therefore, the beam area 16 is also displaced, in order to allow for processing at further joining points that have not yet been processed.

(37) In one alternative variant of the method, the processing also includes further processing methods, for example other laser-based processes such as marking or cutting by means of the (joining) laser, also outside of joining points, and, for example, mechanical processing, in particular deformation, by means of pressing elements, in particular in the time phases in which these pressing elements are not located in the area of the present joining point.

(38) In one further variant of the method, the receptacle 4 is formed as a conveyor belt. The conveyor belt and, therefore, the joining elements 2, 3 are displaced continuously in parallel to the plane E in this variant. This displacement is compensated for by means of the scanner of the joining laser 10 in such a way that the joining laser 10 is stationary, in each case, relative to the particular joining point during the joining process. In this variant, the speed of the movement of the receptacle 4 is selected in such a way that at least all joining points in the transverse direction with respect to the joining laser 10 can be processed.

(39) A method for joining parts to be joined, in the area of a joining point, by means of the laser joining system according to the invention therefore results, by means of which parts to be joined can be joined together with minimal delay and, therefore, particularly cost-effectively and efficiently; in particular a current accumulator can be produced from a plurality of storage cells and a base plate.

LIST OF REFERENCE NUMBERS

(40) 1 laser joining system 2 storage cell 3 base plate 4 receptacle 5 first joining point 5a second joining point 5b third joining point 6 pressing system 7, 7 pressing element 8, 8 parallel positioning device 9, 9 oblique positioning device 10 joining laser 11 laser slide rail 12 joining laser beam 13,13 slide rail 13a, 13a, 13a, 13a linear drive 15, 15 scissors mechanism beam area 17 work area