DE102011087405A1 - Clamping device for laser beam welding - Google Patents

Abstract

Method for operating a clamping device and clamping device (1), designed for joining two components (2, 3) by means of a jet-shaped energy input in a joining region (4), wherein a first and a second clamping element (5, 6) for fixing the two components ( 2, 3) are provided during the energy input under bias and the second clamping element (6) by an inner holder (7) and an outer holder (8) is formed, wherein the inner holder (7) and the outer holder (8) of a circumferential passage gap ( 9) separated from each other and at least one connecting element (10) are held in position relative to each other, characterized in that the at least one connecting element (10) movably mounted and a drive for moving the at least one connecting element (10) in dependence of the movement of the Energy beam is provided.

Description

The invention relates to a clamping device and a method for operating such a clamping device, designed for joining two components by means of a jet-shaped energy input in a joining region, wherein a first and a second clamping element for fixing the two components are provided during the energy input under bias and the second clamping element is formed by an inner holder and an outer holder, wherein the inner holder and the outer holder are held by a circumferential passage gap separated from each other and at least one connecting element in position relative to each other, according to the features of the preamble of the two independent claims.

From the EP 2 136 959 B1 is a generic tensioning device for laser beam welding for clamping at least two components in a working beam using a processing machine known, with a receptacle for mounting the first component and at least one chuck, on each of which a clamping jaw for acting on the second component for introducing clamping pressure in the joint surface is arranged between the two components, wherein the respective clamping jaws is formed as disposed within the rotating beam path of the working beam of the machine tool inner clamping jaws with a clamping surface for internal clamping of the components, further comprising a passage gap for the working beam separates the respective inner jaws from the outer chuck and at least one narrow Connecting strut is provided for connection of the inner clamping jaw to the outer clamping head, which at least one connecting strut to the beam path of the processing machine bridged through the components releasing passage gap. From this prior art it is apparent that for laser beam welding it is necessary that the joining surfaces of the two components to be assembled together must be kept under pretension. For this the beats EP 2 136 959 B1 in that the inner clamping jaw, with which a pressure is applied to the one components to achieve the bias, is connected via a narrow connecting strut to the outer clamping head, wherein the inner clamping jaw and the outer clamping head form a circumferential passage gap for the working beam. This passage gap is required for the energy steel (here a laser beam) to reach the joining region of the two components to be assembled by means of circulating movement and to join them together by applying energy.

In this case, however, there is the difficulty that the entire joining area must be circumferentially energized, so that the laser transmission welding applied here, the two components to be assembled together reliably together. If, during the course of the jointing area, interruptions occur due to a lack of energy input, defects in the joint area arise as a result of which damage can occur when the two assembled components (that is, the finished end component) are stressed. These damages can either lead to an impairment of the functioning of the end component, a complete failure or even a security risk, depending on which function the end component has.

Through the connecting struts, which at the EP 2 136 959 B1 connect the inner clamping jaws to the outer clamping head, such defects may arise in the joint area. In the generic state of the art, therefore, it has already been considered to make these connecting struts narrow, in particular in the presence of a plurality of connecting struts. However, this does not change the fact that the energy input is interrupted by the laser beam through this, albeit narrow connecting struts, so that it comes to defects in the joint area, which can bring the disadvantages described above with it. A certain improvement is indeed through the EP 2 136 959 B1 already achieved, because actually ensure the "narrow" bars in the running form that you can weld through down, so that the seam is almost without flaws. The disadvantageous and complicated thing is that you have to adjust the process (drive slower at the bridge with the laser beam, set the beam diameter and optical conditions extremely accurate), so that it works well. The risk of errors in the process thus increases with the number of potential sources of error.

The invention is therefore based on the object, a clamping device and a method for operating such a clamping device for the beam welding, in particular the laser transmission welding to specify, with which the described disadvantages are avoided. In particular, an assembly of the two components is to be achieved without it comes to defects in the joining area after the joining process.

This object is solved by the features of the independent claims.

According to the invention, a tensioning device is provided in which the at least one connecting element is movably supported and a drive is provided for moving the at least one connecting element as a function of the movement of the energy beam. This movable Storage of the connecting element and an associated drive for moving the at least one connecting element as a function of the movement of the energy beam has the advantage that, when the energy beam comes into the area in which the connecting element is arranged in the passage gap, are moved in such a form It can not interrupt the energy beam. This also has the advantage that when the joint area is being traveled, the energy beam always strikes the joint area. This means that the energy beam according to the invention is no longer interrupted by the connecting element, since it is arranged so movable that it is precisely avoided by this movable arrangement that the energy beam is interrupted by the connecting element. As a result, the very decisive advantage is given that the circumferential joining area is also circumferentially, preferably without interruption, hit by the energy beam without an interruption takes place. This creates a circumferential joining area without defects. It is understood that the movement of the at least one connecting element in the form described above takes place in such a way that by means of the clamping elements still the required pressure to achieve the necessary bias voltage can be applied to the components to be assembled.

In a development of the invention, the at least one connecting element has a passage region for the energy beam. This means that the connecting element is advantageously designed so that on the one hand a force-transmitting connection between the inner holder and the outer holder is given and on the other hand it is possible by the movement of the connecting element with its passage area that the energy beam is not interrupted by the connecting element, when it is moved over the area in which the connecting element is arranged in the passage gap.

In a further development of the invention, the passage region is designed as a recess in a connecting element formed from a solid material. This may be, for example, a notch with a corresponding required cross-section. Alternatively, it is provided according to the invention that the passage region is designed as an opening in a connecting element formed from a pipe material. In this case, both the connecting element are arranged on the inner holder and / or the outer holder and the recess or the opening designed and arranged in the connecting element, that in dependence of the movement of the connecting element and the course of the energy beam this always from the source to the Joining area can run without being interrupted by the connecting element.

In a development of the invention, the drive for the movement of the at least one connecting element is arranged in or on the inner holder and / or in or on the outer holder. As a result, various design options can be realized with which the at least one connecting element, preferably a plurality of connecting elements, can be driven in the desired manner. It can be remembered that the drive is mounted only in or on the inner bracket. Alternatively, the drive may be arranged only in or on the outer holder. Depending on the design of the second clamping element with its inner holder and its outer holder can also be thought to arrange a part of the drives on the inner bracket and another part of the drives on the outer bracket. It can also be thought that each connecting element has its own drive, wherein it is also conceivable that a plurality of connecting elements are combined into a group and this group has its own drive or that all drive elements on the inner bracket and / or the outer bracket a common drive exhibit.

As drive preferably come electric motors for the rotationally symmetrical connection elements into consideration, while piezo-based actuators or pneumatic actuators for the slidably mounted webs can be applied. Pneumatic, magnetic or electrical control elements come into consideration for the variant with the extendable pins / bolts.

Furthermore, a method for operating a clamping device is provided according to the invention, in which the connecting element is movably mounted and is moved in dependence of the movement of the energy beam. Again, the connecting element according to the invention has the task to connect the inner bracket with the outer bracket for applying the required bias (pressure on the joint area) and at the same time to move in response to the moving energy beam that no interruption of the energy beam in its course the energy entry into the joining area to be joined takes place. Under "uninterruptible" may possibly. Such an extremely short-term interruption be understood that does not lead to a defect in the joining of the two components. In order to realize the uninterrupted impact of the energy beam on the joint area, depending on the geometric configuration of the connecting element, different movements into consideration. The connecting element can rotate around its longitudinal axis, axially to its longitudinal axis or reciprocated. With these forms of movement of the connecting element in dependence on the geometric configuration of the connecting element, the advantage is always achieved that the connecting element does not interrupt the course of the energy beam from the source to the joining region due to its geometry and movement in order to achieve an optimum joining result without defects.

In a further development of the invention, depending on the position of the at least one connecting element and the orientation of the energy beam, it impinges on the joining region through a passage region of the connecting element for the energy beam such that the energy beam is not interrupted by the at least one connecting element. This means that the passage region of the at least one connecting element due to its movement and the course of the energy beam correlate with each other so that the energy beam is not interrupted by the at least one connecting element. This leads to the advantageous uninterrupted assembly of the two components.

In a particularly advantageous embodiment of the invention, at least two connecting elements are provided, wherein the at least one connecting element establishes a connection between the inner holder and the outer holder where there is currently no energy beam, and the at least one further connecting element from the passage gap between the inner holder and the Outside holder is moved out, where there is just an energy beam. This means that at least one connecting element, but preferably a plurality of connecting elements, connect the inner holder and the outer holder with one another for the purpose of transmitting power and achieving the desired preload, namely where no energy beam is currently traveling. However, should there be a connecting element when the energy beam moves along the joining region, this is moved out of the passage gap, so that in this region the energy beam is not interrupted by this connecting element. The moving out of this at least one connecting element from the passage gap can be readily carried out, since at least one further connecting element, preferably more than one connecting element, still ensure the frictional connection between the inner holder and the outer holder.

In a further development of the invention, the at least one connecting element is arranged on the inner holder or the outer holder and can be pivoted.

In a further development of the invention, the at least one connecting element is moved by a relative movement between the inner holder and the outer holder. This means that in this case the at least one connecting element is not itself moved by a drive (active movement), but that the movement for the purpose of releasing the energy beam is effected by a relative movement between the inner holder and the outer holder. For this purpose, a drive on the outer holder (possibly also on the inner holder) may be provided.

With this drive, the inner holder and the outer holder are caused to move relative to each other, thereby moving the connecting member. This can be done, for example, with a reduction in the width of the passage gap, characterized in that the connecting element elastically yielding (like a leaf spring) deformed and between two positions back and forth to release the path for the energy beam without interruption. The movements of the elements involved in this case are coordinated so that on the one hand the bias is maintained on the joint area, when a relative movement between the inner holder and the outer holder is brought about for the purpose of movement of the connecting element. For example, a force is applied by the clamping elements perpendicular to the surface of the components, wherein in order to achieve the relative movement, the inner holder and the outer holder are moved perpendicular to this direction of force application for the purpose of movement of the connecting element.

The device thus has an inner clamping jaw for applying a contact pressure to a component for laser beam welding, wherein the inner clamping jaw is held by a movable holding element (eg, axes / tubes / rectangle, etc.).

Example: rotating bracket

• - The holding element has a recess or notch o. Ä.
• - The holding element is rotatably mounted in the outer clamping jaws and in the inner clamping jaws
• - In the welding process, the holding element is rotated about its longitudinal axis, so that the recess / notch alternately releases the welding area (depending on the position of the recess at a certain time)
• The laser beam thus has the possibility, at different times, of covering covered areas of the weld seam, depending on the position of the axis reach and achieve a weld there.
• - It is achieved a full-surface welding using an internal stress

Various embodiments of the clamping device according to the invention and the method according to the invention for operating such a clamping device are shown in the figures.

In 1 is, as far as shown in detail, a clamping device 1 for the assembly of a first component 2 with a second component 3 by means of energy input into a joint area 4 between the first and second component 2 . 3 shown. The mode of operation of the joining method on which the invention is based, in particular laser transmission welding of plastic components, is known in principle. To be in a joining area 4 on which a part of the first component 2 with a part of the second component 3 For example, the first component has come into contact with the system 2 with a first clamping element 5 fixed in his position. Furthermore, a second clamping element 6 present, with which the second component 3 , oriented to the position of the first component 2 , is also fixed in position. It is necessary that the two components 2 . 3 in the joining area 4 under pressure (bias) to each other. For this purpose, it is provided that the second clamping element 6 an inner holder 7 and an outdoor bracket 8th includes, these two brackets 7 . 8th from a passage gap nine are separated from each other. The location of this passage gap nine in its course corresponds to the course of the joint area 4 , This means that from the outside a jet-shaped energy input, for example by means of a laser beam, takes place (when viewing the 1 for example, perpendicular from above the passage gap nine in the direction of the joining area 4 ). This energy input occurs circumferentially along the passage gap nine so that the two components 2 . 3 in their joining area 4 be joined together.

In 2 is the tensioning device 1 according to 1 shown from above. Here is the passage gap nine of at least one connecting element 10 initially interrupted for the energy beam from above, so that when driving off the passage gap nine the energy beam would be interrupted at a fixed connection element. Due to this interruption, the energy beam can not reach the joining area 4 meet, so that it comes to a defect. In order to remedy this situation, this is at least one connecting element 10 movably mounted and a (not shown) drive for moving the at least one connecting element 10 provided in dependence of the movement of the energy beam. This means that when the energy beam is applied to the connecting element 10 too moved, the connecting element 10 so depending on the movement and orientation of the energy beam is moved, that the energy beam always from the source to the joining area 4 can arrive without interruption.

These are exemplified in 3 and 4 Embodiments of connecting elements 10 shown moving on, for example, the inner bracket 7 and the outer bracket 8th are stored. They are on the one hand so on the two brackets 7 . 8th stored that when exercising a force on the outer mount 8th these on the inner holder 7 and these in turn on the two components 2 . 3 is transmitted. With reference to the 1 So are the inner holder 7 and the outer bracket 8th over the connecting element 10 so interconnected that when viewing the 1 upon application of a force from above the component 3 here in its circumferential outer end area in the joining area 4 on the upward-facing peripheral edge of the component 2 is pressed. This pressure or this preload is required in the joint area 4 to achieve an optimal joining with energy input.

Example: movable bracket

• The holding element (s) is / are moved back and forth by means of corresponding movement devices,
• In the welding process, the at least one holding element is moved, so that the welding area is alternately released (depending on the position of the element at a specific time),
• The laser beam thus has the possibility, at different points in time, of reaching covered regions of the weld seam, depending on the position of the element, and of achieving welding there,
• - It is achieved a full-surface welding using an internal stress.

5 shows a further embodiment in which the at least one connecting element 10 on the inner support 7 or the outer bracket 8th is arranged and pivoted. It is in the lower part of this 5 recognizable that the energy beam is first the connecting element 10 approaches and then when he clicks on the fastener 10 This would be timely moved out of the course of the energy beam, so that the energy beam is not affected by the presence of the connecting element 10 is interrupted. This movement of the connecting element 10 may be a pivoting, a displacement or a deformation.

In this embodiment, in which the holding element is movable on the inner clamping jaws is arranged, it serves as the power transmission between the holder and inner clamping jaws, that more than two connecting elements are present. At least one moves while the others maintain power transmission. The power transmission is perpendicular to the movement of the web, so that the storage has no influence on the holding force.

6 shows the embodiment in which at least two connecting elements 10 are provided and the at least one connecting element 10 a connection between the inner bracket 7 and the outer bracket 8th where it is currently no energy beam is (in this case, the connecting element 10 gray shaded and called active), and that at least one other connecting element 10 from the passage gap nine between the inner holder 7 and the outer bracket 8th is moved out, where is currently an energy beam (in 6 shown in dashed lines and referred to as pulled). This means that in this case the connection between the inner bracket 7 and the outer bracket 8th by movable along its longitudinal axis connecting elements 10 he follows.

To get the required forces between the inner bracket 7 and the outer bracket 8th to transfer, are the fasteners 10 preferably rod-shaped with a square or round cross-section.

Furthermore, it should be noted that means for applying the required pressures and for moving the connecting elements 10 present but not shown in the figures. Moreover, it is also conceivable that along the passage gap nine not just one energy beam, but more than one energy beam (for example, exactly two energy beams) are guided.

Example: pullable bracket

• - The holding elements can be pulled corresponding movement devices and pushed back to the internal tension,
• In the welding process, the holding elements are alternately moved, so that the welding area is alternately released, but at the same time always a group of holding elements maintains the internal tension,
• The laser beam thus has the possibility, at different points in time, of reaching covered regions of the weld seam, depending on the position of the elements, and of achieving welding there,
• - It is achieved a full-surface welding using an internal stress.

• Connecting element = retaining element

LIST OF REFERENCE NUMBERS

1

jig

2

First component

3

Second component

4

joining area

5

First clamping element

6

Second clamping element

7

inside mount

8th

Outside mount

9

Passage gap

10

connecting element

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 2136959 B1 [0002, 0002, 0004, 0004]

Claims (10)

Clamping device ( 1 ), designed for joining two components ( 2 . 3 ) by means of a jet-shaped energy input in a joining region ( 4 ), wherein a first and a second clamping element ( 5 . 6 ) for fixing the two components ( 2 . 3 ) are provided during the energy input under bias and the second clamping element ( 6 ) of an inner support ( 7 ) and an outer holder ( 8th ), wherein the inner support ( 7 ) and the outer bracket ( 8th ) from a circumferential passage gap ( nine ) separated from each other and at least one connecting element ( 10 ) are held in position relative to each other, characterized in that the at least one connecting element ( 10 ) movably mounted and a drive for moving the at least one connecting element ( 10 ) is provided depending on the movement of the energy beam. Clamping device ( 1 ) according to claim 1, characterized in that the at least one connecting element ( 10 ) has a passage area for the energy beam. Clamping device ( 1 ) according to claim 2, characterized in that the passage region as a recess in a connecting element formed from a solid material ( 10 ) is designed. Clamping device ( 1 ) according to claim 2, characterized in that the passage area as an opening in a connecting element formed from a pipe material ( 10 ) is designed. Clamping device ( 1 ) according to one of the preceding claims, characterized in that the drive in or on the inner holder ( 7 ) and / or in or on the outer holder ( 8th ) is arranged. Method for operating a tensioning device ( 1 ), designed for joining two components ( 2 . 3 ) by means of a jet-shaped energy input in a joining region ( 4 ), wherein a first and a second clamping element ( 5 . 6 ) the two components ( 2 . 3 ) during the energy input under bias and hold the second clamping element ( 6 ) of an inner support ( 7 ) and an outer holder ( 8th ), wherein the inner support ( 7 ) and the outer bracket ( 8th ) from a circumferential passage gap ( nine ) separated from each other and at least one connecting element ( 10 ) are held in position relative to each other, characterized in that the connecting element ( 10 ) is movably mounted and is moved in response to the movement of the energy beam. A method according to claim 6, characterized in that depending on the position of the at least one connecting element ( 10 ) and the orientation of the energy beam through a passage region of the at least one connecting element ( 10 ) for the energy beam on the joint area ( 4 ) that the energy beam through the at least one connecting element ( 10 ) is not interrupted. Method according to claim 6, characterized in that at least two connecting elements ( 10 ) are provided and the at least one connecting element ( 10 ) a connection between the inner bracket ( 7 ) and the outer bracket ( 8th ) where there is currently no energy beam, and that at least one further connecting element ( 10 ) from the passageway ( nine ) between the inner bracket ( 7 ) and the outer bracket ( 8th ) is moved out, where is currently an energy beam. Method according to one of claims 6 to 8, characterized in that the at least one connecting element ( 10 ) on the inner bracket ( 7 ) or the outer bracket ( 8th ) is arranged and is pivoted. Method according to one of claims 6 to 8, characterized in that the at least one connecting element ( 10 ) by a relative movement between the inner holder ( 7 ) and the outer bracket ( 8th ) is moved.

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