DE102018113225A1 - Method and device for electrically conductive connection of a bus bar for a vehicle with a branching tab - Google Patents

Abstract

The present invention relates to a method for the electrically conductive connection of a busbar (102) for a vehicle with a branching tab (104), in which an end region (11) overlapping on a flat side (116) of the busbar (102) is welded using a welding process ( 114) of the tab (104) is welded to the bus bar (102), wherein an arc (118) ignited between an electrode (120) and the bus bar (102) and the tab (104) in a protective gas environment (122) at a relative speed to the bus bar (102) and the tab (104) on a trajectory extending along at least one edge (124) of the end portion (114) relative to the bus bar (102) and the tab (104), the edge (124) and an adjacent region of the flat side (116) are melted additive-free to a molten melt bath (126) and solidify into a weld bead (128), wherein at least one Prozessp parameter (130) of the welding process is monitored and the weld bead (128) is classified as defective if the process parameter (130) is outside of a parameter tolerance range (132).

Description

Technical area

The present invention relates to a method and a device for electrically conductive connection of a bus bar for a vehicle with a branching tab.

State of the art

The present invention will be described below mainly in connection with power distributors for vehicle electrical systems. However, the invention can be used in any application in which electricity is distributed to electrical loads.

In a vehicle with an electric traction drive result in the operation of the traction drive large electrical currents. The high currents require large conductor cross sections of the electrical conductors. These conductors can be designed as busbars made of solid metal material. The busbars can be integrally stamped or cut from sheet metal and bent. The busbars can therefore be designed as stamped and bent parts. The busbars can also be manufactured by extrusion. For supplying, for example, auxiliary equipment, main power consumers, circuit breakers or power distributors, the busbars can be punched out of the sheet metal with all the necessary branching tabs.

Description of the invention

An object of the invention is therefore to simplify the manufacture of busbars using structurally simplest possible means.

The object is solved by the subject matters of the independent claims. Advantageous developments of the invention are specified in the dependent claims, the description and the accompanying figures. In particular, the independent claims of a claim category can also be developed analogously to the dependent claims of another claim category.

It is a method for electrically conductive connecting a bus bar for a vehicle presented with a branching off of the bus bar, in which
using a welding process, an end portion of the tab overlapping on a flat side of the bus bar is welded to the bus bar, wherein an arc ignited between an electrode and the bus bar and the tab in a protective gas environment at a relative speed to the bus bar and the tab along at least one an edge of the end region extending trajectory is guided relative to the busbar and the tab, wherein the edge and an adjacent region of the flat side are melted additive-free to a molten melt bath and solidify into a bead, wherein at least one process parameter of the welding process is monitored and the weld bead as is classified as faulty if the process parameter is outside of a parameter tolerance range,
wherein the weld bead and at least adjacent to the weld bead portions of the bus bar and the tab are measured three-dimensional after solidification using a surveying process, wherein the weld bead is classified as defective if at least one test criterion is outside of a criterion tolerance range.

Furthermore, a method for electrically-conductive connection of a bus bar for a vehicle with a branching off of the bus bar is presented in which using a welding process on a flat side of the bus bar overlapping aligned end portion of the tab is welded to the busbar, one between a Electrode and the bus bar and the tab ignited arc in a protective gas environment at a relative speed to the bus bar and the tab on one along a first side edge of a projecting over a first side surface of the tab first protrusion of the end portion, along an end edge of the end portion and along a second side edge a running over a second side surface of the tab projecting second projection of the end portion extending U-shaped trajectory relative to the bus bar and the tab, wherein the side edges, the end edge and a boundary The area of the flat side are melted additive-free to a molten melt bath and solidify into a weld bead, wherein at least one process parameter of the welding process is monitored and the weld bead is classified as defective if the process parameter is outside of a parameter tolerance range.

Further, a device for electrically conductive connection of a bus bar for a vehicle with a branching tab is presented, the device having the following features;
a receiving means for aligning and temporarily fixing an end portion of the tab on a flat side of the bus bar;
a welding head for generating an arc between an electrode and the bus bar and the tab;
a feed device for moving the welding head at a relative speed on a trajectory relative to the bus bar and the tab;
a monitoring device configured to monitor a resulting weld bead using at least a process parameter of the welding process, the weld bead classified as defective if the process parameter is outside of a parameter tolerance range.

Under a busbar, a massive flat conductor can be understood. The busbar may consist of an aluminum material. The tab can also be referred to as a flat conductor. The tab can also be made of aluminum material. The busbar and the tab may be made of the same aluminum material. The busbar and the tab can both be referred to as aluminum flat conductor. The busbar and the tab can also be butt welded. An aluminum material may be understood to mean a material that consists of aluminum or an aluminum alloy or that essentially comprises aluminum.

Alternatively or more generally, therefore, a method for electrically conductive joining of aluminum flat conductors is presented, in which
using a welding process, an end portion of the other aluminum flat conductor overlapping one flat side of the aluminum flat conductor is welded to the one aluminum flat conductor, wherein an arc ignited between an electrode and the aluminum flat conductors in a protective gas environment at a relative speed to the aluminum flat conductors on at least one edge of the Wherein the edge and an adjacent region of the flat side are melted additive-free to a molten melt bath and solidify into a bead, wherein at least one process parameter of the welding process is monitored and the weld bead is classified as defective, if the Process parameter is outside of a parameter tolerance range,
wherein the weld bead and at least adjacent to the weld bead portions of the aluminum flat conductors are measured three-dimensional after solidification using a surveying process, wherein the weld bead is classified as defective if at least one test criterion is outside of a criterion tolerance range.

Furthermore, alternatively or more generally, a method for electrically conductive bonding of aluminum flat conductors is presented in which using a welding process on one flat side of an aluminum flat conductor overlapping aligned end portion of the other aluminum flat conductor is welded to the one aluminum flat conductor, one between an electrode and the Aluminum flat conductors ignited arc in a protective gas environment at a relative speed to the aluminum flat conductors on one along a first side edge of a protruding over a first side surface of the other aluminum flat conductor first projection of the end portion, along an end edge of the end portion and along a second side edge of a second side surface of the other aluminum flat conductor protruding second projection of the end portion extending U-shaped trajectory relative to the aluminum flat conductors wi rd, wherein the side edges, the front edge and an adjacent region of the flat side are melted additive-free to a molten melt bath and solidify into a weld bead, wherein at least one process parameter of the welding process is monitored and the weld bead is classified as defective if the process parameter is outside of a parameter tolerance range ,

The busbar and the tab or the aluminum flat conductors are hereinafter referred to as simplification case by case as workpieces. A welding process can be understood as meaning a thermal joining process in which the workpieces are connected to one another by a weld bead of solidified melt. To produce the melt, the aluminum material of the workpieces is heated by an energy input to the extent that the aluminum material is at least locally molten and mixed in a melt bath. In the method presented here, no additive is added to the aluminum material or the melt. It is thus melted by the energy input so only the aluminum material of the workpieces, mixes and solidifies to the workpieces electrically and mechanically connecting weld bead.

The energy input is made by an electric arc. The arc is ignited between a non-reflowing electrode of a welding head and the workpieces electrically contacted by the receiving device. The electrode may, for example, consist of a tungsten material. The energy input is thereby optimized so that a heat affected zone of the melt bath is small. In particular, the busbar is melted only to a small depth by the optimized energy input, while the edge of the tab is completely melted. The energy input can be determined by process parameters to be influenced. For example, the energy input can be influenced by an exposure time of the arc and an intensity of the arc. The intensity of the arc can be influenced by a current, an electrical voltage, a distance between the electrode and the workpieces and a frequency of the current flow or the voltage.

The exposure time can essentially be influenced by the relative speed with which the electrode and the workpieces are moved relative to one another. The relative speed is generated by the welding head and / or the receiving device are moved by the feed device. The welding head and / or the receiving device can be movable. For example, the welding head may be driven in two axes while the receiving device is driven in one axis. The feed device can also be multiaxial, for example with five driven axles.

In a protective gas environment, ambient air, in particular the atmospheric oxygen, may be displaced by a protective gas in order to prevent oxidation of the aluminum material. The protective gas may be an inert protective gas. The protective gas environment can also be referred to as a protective gas atmosphere. The protective gas environment can be generated by a bell surrounding the arc of protective gas flowing out. For example, the electrode may be arranged coaxially with a nozzle for the protective gas. Likewise, a working space in which the arc is ignited, be flooded with the protective gas.

As a process parameter, for example, an electric current of the arc, an electric voltage of the arc, a flow rate of the protective gas and / or the relative speed can be monitored. These process parameters can be easily monitored.

The busbar and the tab or the aluminum flat conductor may have different cross-sectional areas. The cross-sectional areas may in particular be rectangular. The tab may have a smaller cross-sectional area than the busbar. The weld bead may have at least one line cross-section corresponding to the cross-sectional area of the flap.

The busbar can be electrically insulated by an insulating sheath. The insulation cover has a recess for connection to the tab. Per recess also several tabs can be connected to the busbar. It can also be connected to different tabs at different positions to the power rail. In a recess at least a portion of the flat side and a portion of a remote from the flat side back of the busbar can be accessible. The tab can also be electrically insulated by an insulation sheath. The end region, which is in direct contact with the busbar, is then excluded from the insulation sheath.

The device may comprise a measuring device which is designed to measure the weld bead and at least adjacent to the weld bead portions of the bus bar and the tab after solidification three-dimensionally. The monitoring device may be configured to further evaluate the weld bead using at least one test criterion. The weld bead may be considered faulty if the test criterion is outside a criterion tolerance range. The surveying device may be designed to carry out a surveying process. The surveying process can be an optical surveying process. The surveying process can be contactless. The measuring process can be used to record the shape and position of the weld bead and to monitor shape and position tolerances for the weld bead as test criteria.

The weld bead can be measured using a laser triangulation process. In a laser triangulation process, a laser beam or a laser line or a laser line and / or line pattern with an emission angle within a detection range projected onto the workpieces and a point of incidence of the laser beam, points of incidence of the laser beams, a line of incidence of the laser line or lines of impact of the laser lines optically detected a detection angle. Due to an angular difference between the emission angle and the detection angle, a change in the distance between the measurement device and the workpieces or the weld bead results in a lateral offset of the point of impact or of the impact line. The point of impingement or the impingement line can be imaged on picture elements of an optical sensor by means of imaging optics. The lateral offset is imaged in a change of image coordinates of the impact point or the impact line. The image coordinates can be monitored in the monitoring device. The laser triangulation process enables high resolution in a robust process.

For measuring the weld bead, a measurement range and the bead can be moved relative to each other. The surveying device can be coupled to the welding head his. The surveying range of the surveying device may be movable relative to the bus bar and the tab. Due to the relative movement, the weld bead with the adjacent subregions can be scanned optically. Due to the relative movement, a point cloud or a three-dimensional image of the welding bead and of the adjacent sub-areas can be generated from a chronological sequence of individual measurements.

As a test criterion, a scaling of the weld bead can be used. The weld bead may be considered defective if a distance between individual scales of the weld bead is more irregular than a fluctuation tolerance. If the scaling is regular, the energy input was also regular. If the scaling is irregular, then in some places more energy has been registered, as in other places.

As a test criterion, a starting point and / or an end point of the weld bead can be used. The weld bead may be considered defective if a score of the starting point and / or the end point is greater than a notch value. To ignite the arc, the electrical voltage can be briefly increased until the arc builds up. Similarly, a distance between the workpieces and the electrode can be temporarily reduced until the arc builds up. In both cases a high energy input results locally, through which a lot of aluminum material can melt. A notch can occur if the melt in the melt bath flows away from the starting point and / or end point due to the gravitational pull in order to compensate for height differences. The notch can reduce the line cross section.

As a test criterion, a height jump can be used between the partial areas adjacent to the weld bead. The weld bead may be considered faulty if the height jump is outside of a jump tolerance range. For example, a too high altitude jump may indicate foreign bodies between both workpieces. Likewise, thermal stresses in at least one of the workpieces can lead to a distortion of the weld bead.

As a test criterion, a hole size of holes and / or voids in the weld bead can be used. The weld bead may be considered defective if a hole or voids is greater than a hole limit. Through a hole or a blower, the line cross-section of the weld bead can be reduced.

The receiving device may have a heat-conducting bearing surface for the busbar and / or the tab. The receiving device may have a groove for receiving the busbar. The groove may define a position of the bus bar in at least one axis. The support surface for laying the busbar may be arranged in the groove in order to produce an electrically and thermally conductive contact between the busbar and the receiving device. The support surface may be made protruding to bridge a thickness of the insulation sheath.

The receiving device may have at least one stop surface and / or at least one receiving mandrel for the tab. The tab can be applied to a stop surface to be aligned in one axis. For aligning in two axes, the tab can be attached to two stop surfaces. A pick-up mandrel can be used to align a breakthrough through the tab in one or two axes. The abutment surface and / or the arbor can be withdrawn or removed after fixing in order to allow thermal expansion through the welding process.

The arc can be performed on a rounded U-shaped trajectory with arcuate transition curves. The tab may have accordingly rounded edges running. By transition curves a uniform relative speed can be achieved. The transition curves avoid sharp corners. The feed device is relieved by transition curves, as accelerated and / or to be braked masses of the welding head and / or the receiving device are accelerated and / or braked over a longer path.

The arc can be operated pulsed. In a pulsed operation, the arc is ignited in short successive intervals and goes out after a short period of operation again. While the arc is ignited, the arc can be operated with AC or DC voltage. Due to the pulsed operation, the energy input can be controlled. Due to the repeated ignition of the arc, a surface of the melt bath is repeatedly torn open, which leads to a strong mixing of the melt of both workpieces. In addition, any existing oxide layers are destroyed.

Also of advantage is a computer program product or computer program with program code which can be stored on a machine-readable carrier or storage medium such as a semiconductor memory, a hard disk memory or an optical memory and for carrying out, implementing and / or controlling the steps of Method according to one of the embodiments described above, in particular when the program product or program is executed on a computer or a device.

list of figures

• 1 eine Darstellung einer Vorrichtung gemäß einem Ausführungsbeispiel;
• 2 eine Darstellung einer Aufnahmeeinrichtung gemäß einem Ausführungsbeispiel;
• 3 eine Darstellung einer in einer Aufnahmeeinrichtung gemäß einem Ausführungsbeispiel aufgenommenen und geklemmten Stromschiene und Lasche;
• 4 eine Darstellung einer aus einer U-förmigen Bahnkurve gemäß einem Ausführungsbeispiel resultierenden U-förmigen Schweißraupe;
• 5 eine Darstellung eines Schliffbilds einer gemäß einem Ausführungsbeispiel geschweißten Schweißraupe;
• 6 eine Darstellung eines gemäß einem Ausführungsbeispiel erfassten Vermessungsergebnisses eines Gutteils; und
• die 7 und 8 Darstellungen von gemäß Ausführungsbeispielen erfassten Vermessungsergebnissen von Schlechtteilen.

Hereinafter, an advantageous embodiment of the invention will be explained with reference to the accompanying figures. Show it:

• 1 a representation of a device according to an embodiment;
• 2 an illustration of a receiving device according to an embodiment;
• 3 a representation of a received and clamped in a receiving device according to an embodiment of bus bar and strap;
• 4 a representation of a resulting from a U-shaped trajectory according to an embodiment U-shaped weld bead;
• 5 a representation of a micrograph of a welded according to an embodiment of welding bead;
• 6 a representation of a detected according to an embodiment survey result of a good part; and
• the 7 and 8th Representations of measured according to embodiments survey results of bad parts.

The figures are merely schematic representations and serve only to illustrate the invention. Identical or equivalent elements are consistently provided with the same reference numerals.

Detailed description

The material aluminum as an electrical conductor in an automotive wiring harness is becoming increasingly important. The challenge with the use of aluminum is the connection to existing contact systems made of copper.

Aluminum is not released due to the setting behavior for electrical contacting for screw connections.

Remedy here are copper-aluminum sheets which are connected by roll-plating. With the help of these sheets, a cable lug can be screwed on the copper side and a cohesive connection with an aluminum conductor can be achieved on the aluminum side.

In the approach presented here, a cohesive contacting is achieved for electrically contacting two aluminum flat conductors to which the weld is not explicitly protected.

In the cohesive connection of both aluminum materials, corrosion due to the electrochemical series of different materials is avoided.

The contacting of two identical aluminum materials takes place by fusing the two joining partners with the aid of an arc in a protective gas environment. Due to the introduced energy of the arc, both components are melted and combine in a melt bath. There are no additional materials needed.

Due to the identical combination of materials of the joining partners under a protective gas environment without filler material is achieved that a fabric-free contacting of the two joining partners arises.

Due to the clearly visible weld seam and its characteristics, the quality can be checked and ensured. Thus, a redundant test is possible.

The welding process presented here produces a low-resistance joint to avoid a so-called hotspot. This results in a mechanically and thermally stable connection of the joining partners. The welding process has high process reliability and is cost-effective. There is the possibility for easy testing after the welding process.

The welding process presented here is a modified TIG welding process. An electric arc burns between the tungsten electrode and the workpiece. "Inert" shielding gases are used. The welding takes place without additives. The welding process does not generate spatter. Due to the short welding time, only a small amount of heat is introduced into the component. During the welding process, the welding head, guided by a robot, moves the welding contour.

In addition to the monitoring of the parameters at the welding system (current, time, gas flow, ...), a redundant test procedure can be carried out, which works independently of the parameter monitoring of the welding system, but is applied immediately after the welding process. A 3D laser scanner is used for this purpose.

1 shows a representation of a device 100 according to an embodiment. The device 100 is trained to be one conductor rail 102 for a vehicle with a branching tab 104 connect electrically conductive and to perform a method according to the approach presented here. For this purpose, the device 100 a recording device 106 , a welding head 108 , a feed device 110 and a monitoring device 112 on. The recording device 106 is mechanical with the busbar 102 and the tab 104 connected and adapted to an end portion 114 the tab 104 on a flat side 116 the busbar 102 align and temporarily fix. The welding head 108 is designed to perform an arc to perform a welding process 118 between an electrode 120 and the busbar 102 and the tab 104 in a protective gas environment 122 to create. The feed device 110 is with the recording device 106 and the welding head 108 coupled and adapted to the welding head 108 with a relative speed relative to that in the receiving device 106 fixed busbar 102 and tab 104 to move on a trajectory. The trajectory runs along at least one edge 124 the tab 104 , Through the arc 118 be the edge 124 and an adjacent area of the flat side 116 additive-free to a molten melt bath 126 melted and then solidify into a weld bead 128 , The monitoring device 112 is designed to at least one process parameter 130 to monitor the welding process and the welding bead 128 as faulty if the process parameter 130 outside of a parameter tolerance range 132 lies.

In one embodiment, the device 100 a measuring device 134 on. The measuring device 134 with the monitoring device 112 connected. The measuring device 134 is designed to weld the bead 128 and at least to the welding bead 128 adjacent parts of the busbar 102 and the tab 104 after solidification using a surveying process to measure three-dimensionally and at least one test criterion for the monitoring device 112 provide. In the monitoring device 112 becomes the welding bead 128 classified as defective if the test criterion 136 outside of a criterion tolerance range 138 lies.

In one embodiment, the surveying device is 134 with the welding head 108 mechanically coupled. This will make the survey device 134 from the feed device 110 simultaneously with the welding head 108 relative to the receiving device 106 with the busbar 102 and the tab 104 emotional. For measuring the weld 128 here is a survey area 140 the surveying device 134 relative to the weld 128 moved by the surveying device 134 with the welding head 108 is moved. In this case, the survey area 140 For example, be moved along the trajectory by the welding head 108 the trajectory may be lowered again with an offset. Likewise, the welding head 108 be moved on a surveying trajectory on which the surveying device 134 the weld 128 each can measure from an optimized survey angle.

In one embodiment, the surveying device is 134 a laser triangulation device. This is the weld 128 with the adjoining surfaces from a first direction using one in the survey area 140 directed laser beam 142 or one in the survey area 140 directional laser line illuminated and the survey area 140 optically detected from another direction. In other words, in the surveying device 134 a laser source spaced by a base distance from an imaging optics and illuminate or capture the same survey area 140 ,

2 shows a representation of a recording device 106 according to an embodiment. The recording device 106 corresponds essentially to the receiving device in 1 , The recording device 106 has a groove 200 for receiving the busbar and stop surfaces 202 for aligning the tab. The busbar is first in the groove 200 placed on a plant edge 204 the groove 200 pushed and in a longitudinal direction, for example, not shown here across the contact edge 204 aligned aligned further stop surface. Subsequently, the busbar is fixed in this position. The tab is used to align with a support surface 206 the receiving device 106 launched. The bearing surface 206 indicates a height offset to a bottom of the groove 200 on. The height offset is set so that one end portion of the tab comes to lie on the flat side of the busbar. The tab is on the support surface 206 to the stop surfaces 202 pushed and fixed in position. This aligns the tab with the busbar. The fixing takes place, for example, by clamping lever, not shown here or a pneumatically or hydraulically operated fixing.

In one embodiment, the receiving device 106 one in the groove 200 arranged further bearing surface 208 on. The additional contact surface 208 is a material thickness of an insulation of the busbar over the bottom of the groove 200 in front. The additional contact surface 208 bridges a gap between the bottom of the groove and an uninsulated underside facing away from the flat side Busbar. The additional contact surface 208 is made of a particularly good heat conducting material and is located over a large area of the receiving device 106 to quickly dissipate the heat introduced into the busbar during welding.

In one embodiment, not shown, at least one of the stop surfaces 202 replaced by a mandrel. The arbor engages when inserting the busbar or the tab for aligning the tab or the busbar in a corresponding recess and defined at least in one direction, the location of the busbar or tab.

3 shows a representation of a in a receiving device 106 according to an embodiment recorded and clamped busbar 102 and tab 104 , The recording device 106 corresponds essentially to the receiving device in 2 , The tab 104 is transverse to the busbar 102 aligned. In particular, the tab 104 at right angles to the busbar 102 aligned. The busbar 102 lies on the here concealed further contact surface and on the here concealed contact edge. The tab 104 lies on the now concealed support surface and on the stop surfaces 202 on. The end area 114 the tab overlaps the support surface and lies on the stripped flat side 116 the busbar 102 on. A clamping claw 300 pushes the tab 104 on the support surface and the flat side 116 , The end area 114 is with transition radii 302 rounded. The transition radii 302 run tangentially in side surfaces of the end region 114 and an end face of the end portion 114 on.

4 shows a representation of a resulting from a U-shaped trajectory according to an embodiment U-shaped weld bead 128 , The welding bead 128 essentially corresponds to the weld bead in 1 , The welding bead 128 connects the busbar 102 electrically conductive and mechanically with the tab 104 , Next to the welded tab 104 is a tab 104 presented before the welding process. The end area 114 the non-welded flap 104 is on the flat side 116 the busbar 102 arranged. In the end area 114 has the tab 104 on both sides over the side surfaces of the tab 104 protruding projections 400 on. Through the projections 400 is the end face of the end area 114 wider than a cross-sectional area of the tab 104 , The projections 400 and the frontal area are like in 3 with transition radii 302 rounded. Facing away from the front side backs of the projections 400 and the side surfaces of the tab 104 are rounded with other transition radii.

In other words, the end area 114 through the projections 400 T-shaped widened.

The U-shaped trajectory on which the arc relative to the tab 104 and the busbar 102 is or has been, runs along a first side edge 402 one of the projections 400 , along an edge of the first transition radius 302 , along a front edge 404 the end face, along an edge of the second transition radius 302 and along a second side edge 406 the other projection 400 , The trajectory can also be parallel offset.

The energy input of the arc, the aluminum material is melted on both sides of the trajectory to the melt and mixes. The edges of the end area 114 are completely melted. The projections 400 are mostly melted. A surface tension of the melt results in the slightly curved U-shaped weld bead 128 ,

5 shows a representation of a micrograph of a welded according to an embodiment of welding bead 128 , The welding bead 128 essentially corresponds to the weld bead in 4 , The welding bead 128 connects the busbar 102 and the tab 104 electrically conductive and mechanically with each other. The welding bead 128 is shown here cut transversely to its main extension direction. The busbar 102 is more than twice as thick as the tab 104 , A Einbrandtiefe the arc is at the power rail 102 about a quarter of the material thickness. The heat affected zone is therefore correspondingly low. At the tab 104 the full material thickness has been melted. By gravity, melt is from the tab 104 in the direction of the busbar 102 flowed. Due to the surface tension of the melt bath, a gently curved surface has formed which is substantially tangential to a surface of the tab 104 enters. Upon solidification of the melt bath is a solidification front of the unfused aluminum material of the busbar 102 and the tab 104 penetrated into the melt.

6 shows a representation of a detected according to an embodiment survey result of a good part. The survey result is a three-dimensional image 600 one according to the approach presented here on a power rail 102 welded tab 104 , The image 600 is composed of individual measuring points. Each measuring point has three coordinate values. Here, measuring points with the same height value have the same shading. This results in isolines of the same shade.

A shape and position as well as a shape of the weld 128 are clearly shown in the survey result. Here is a purpose designed weld 128 displayed. The weld 128 runs from a starting point 602 U-shaped to an end point 604 , At the starting point 602 and at the endpoint 604 indicates the weld 128 a notch on. The notch is less than a notch value here. This is the weld shown here 128 in order.

7 shows a representation of a detected according to an embodiment measurement result of a bad part. The survey result is shown as in 6 , In contrast, the weld indicates 128 a blowhole 700 on. In the area of the blowhole 700 is the surface of the weld 128 dropped. The blowhole 700 is easily recognizable by the isolines of the same height values. The blowhole 700 is greater than a hole limit. The weld shown here 128 is not in order or faulty and thus reject.

8th shows a representation of a detected according to an embodiment measurement result of another bad part. The weld 128 is executed here incomplete. The endpoint 604 is out of tolerance for the endpoint 604 , In addition, the notch of the endpoint is 604 greater than the notch value. The weld shown here 128 is not in order or faulty and thus reject.

In contrast, a scaling of the weld 128 in order. The distances between individual scales of the weld 128 are more regular than a fluctuation tolerance.

As the devices and methods described in detail above are exemplary embodiments, they may be readily modified by one skilled in the art to a wide extent without departing from the scope of the invention. In particular, the mechanical arrangements and the size ratios of the individual elements to each other are merely exemplary.

LIST OF REFERENCE NUMBERS

100

Device for connecting

102

conductor rail

104

flap

106

recording device

108

welding head

110

feeder

112

monitoring device

114

end

116

flat side

118

Electric arc

120

electrode

122

Inert gas environment

124

edge

126

molten bath

128

bead

130

process parameters

132

Parameter tolerance range

134

measuring device

136

criterion

138

Criterion tolerance range

140

measurement range

142

laser beam

200

groove

202

stop surfaces

204

contact edge

206

bearing surface

208

additional contact surface

300

clamping shoe

302

Transition radius

400

head Start

402

first side edge

404

front edge

406

second side edge

600

image

602

starting point

604

endpoint

700

Lunker

Claims (20)

A method of electrically interconnecting a busbar (102) for a vehicle having a branching tab (104), wherein - using a welding process, an end portion (114) of the tab (104), overlapping said flat side (116) of the busbar (102) ) is welded to the bus bar (102), wherein an arc (118) ignited between an electrode (120) and the bus bar (102) and the tab (104) in a protective gas environment (122) at a relative speed to the bus bar (102) and the tab (104) on at least one edge (124) of the end portion (114). extending trajectory relative to the bus bar (102) and the tab (104), wherein the edge (124) and an adjacent region of the flat side (116) are melted additive-free to a molten melt bath (126) and a weld bead (128). solidify, wherein at least one process parameter (130) of the welding process is monitored and the weld bead (128) is classified as defective if the process parameter (130) is outside a parameter tolerance range (132), - wherein the weld bead (128) and at least to the weld bead (128) adjusts adjacent portions of the bus bar (102) and the tab (104) after solidification using a surveying process three-dimensional, wherein the weld bead (128) is classified as defective if at least one test criterion (136) outside a criterion tolerance range (138 ) lies. A method of electrically interconnecting a bus bar (102) for a vehicle having a branching tab (104), wherein, using a welding process, an end portion (114) of the tab (104) overlapping said flat side (116) of the bus bar (102). is welded to the bus bar (102), wherein an arc (118) ignited between an electrode (120) and the bus bar (102) and the tab (104) in a protective gas environment (122) at a relative speed to the bus bar (102) and the tab (104) along a first side edge (402) of a first projection (400) of the end portion (114) projecting beyond a first side surface of the tab (104) along an end edge (404) of the end portion (114) and along a first edge (404) second side edge (406) of a second protrusion (400) of the end portion (114) projecting beyond a second side surface of the tab (104), relative to the current rail (102) and the tab (104) is guided, wherein the side edges (402, 406), the end edge (404) and an adjacent region of the flat side (116) are melted additive-free to a molten melt bath (126) and a weld bead (128) solidifying, wherein at least one process parameter (130) of the welding process is monitored and the weld bead (128) is classified as defective when the process parameter (130) is outside of a parameter tolerance range (132). Method according to Claim 1 in which the arc (118) is formed along a first side edge (402) of a first projection (400) of the end portion (114) projecting beyond a first side surface of the tab (104) along an end edge (404) of the end portion (114). and is guided along a second side edge (406) of a U-shaped trajectory extending beyond a second side surface of the tab (104) over the second projection (400) of the end portion (114). Method according to Claim 2 in which the weld bead (128) and at least parts of the bus bar (102) and the tab (104) adjacent to the weld bead (128) are measured three-dimensionally after solidification using a measuring process, whereby the weld bead (128) is classified as faulty if at least one check criterion (136) is outside of a criterion tolerance range (138). Method according to one of the preceding claims, wherein the arc (118) is guided on a U-shaped trajectory rounded with arc-shaped transition curves. A method according to any one of the preceding claims, wherein the weld bead (128) is measured using a laser triangulation process. Method according to one of the preceding claims, in which a surveying area (140) and the welding bead (128) are moved relative to one another for measuring the welding bead (128). Method according to one of the preceding claims, wherein as a test criterion (136) a scaling of the weld bead (128) is used, wherein the weld bead (128) is classified as defective, if a distance between individual scales of the weld bead (128) more irregular than a fluctuation tolerance is. Method according to one of the preceding claims, in which a starting point (602) and / or an end point (604) of the welding bead (128) is used as the checking criterion (136), wherein the welding bead (128) is classified as faulty if a notch of the Start point (602) and / or the end point (604) is greater than a Notch value. Method according to one of the preceding claims, in which a jump in height between the partial regions adjoining the weld bead (128) is used as test criterion (136), wherein the weld bead (128) is classified as defective if the height jump lies outside a jump tolerance range. Method according to one of the preceding claims, wherein a hole size of holes and / or voids (700) in the weld bead (128) is used as the test criterion (128), wherein the weld bead (128) is classified as defective if a hole or voids (700) is greater than a hole limit. Method according to one of the preceding claims, in which an electric current intensity of the electric arc (118), an electrical voltage of the electric arc (118), a flow rate of the protective gas and / or the relative speed is monitored as the process parameter (130). Method according to one of the preceding claims, in which the arc (118) is pulsed. An apparatus (100) for electrically connecting a bus bar (102) for a vehicle having a branching tab (104), the apparatus (100) having the following features; a receiving device (106) for aligning and temporarily fixing an end region (114) of the tab (104) on a flat side (116) of the bus bar (102); a welding head (108) for generating an arc (118) between an electrode (129) and the bus bar (102) and the tab (104); feed means (110) for moving the welding head (108) at a relative speed on a trajectory relative to the bus bar (102) and the tab (104); a monitoring device (112) which is designed to monitor a resulting weld bead (128) using at least one process parameter (130) of the welding process, wherein the weld bead (128) is classified as defective if the process parameter (130) is outside a parameter tolerance range ( 132). Device (100) according to Claim 14 , comprising a measuring device (134) which is designed to three-dimensionally measure the weld bead (128) and at least portions of the bus bar (102) and the tab (104) adjoining the weld bead (128) after solidification, wherein the monitoring device ( 112) is adapted to further evaluate the weld bead (128) using at least one test criterion (136), wherein the weld bead (128) is classified as defective if the test criterion (136) is outside of a criterion tolerance range (138). Device (100) according to Claim 15 in that the surveying device (134) is coupled to the welding head (108) and a surveying region (140) of the surveying device (134) is movable relative to the busbar (102) and the tab (104). Device (100) according to one of the preceding claims, in which the receiving device (106) has a heat-conducting bearing surface (208) for the busbar (102) and / or the tab (104). Device (100) according to one of the preceding claims, wherein the receiving device (106) has at least one stop surface (202) and / or at least one receiving mandrel for the tab (104). A computer program product adapted to execute a method according to one of the following upon execution of the computer program product on a computer Claims 1 to 13 execute, implement and / or control. Machine readable storage medium carrying the computer program product according to Claim 19 is stored.

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