Erhardt + Abt using the KUKA KR 16 to automate the painting of rear axle drive shafts
Since its founding in 1997, Erhardt + Abt Automatisierungstechnik GmbH has installed over 300 robots into systems worldwide
As a certified KUKA system partner, Erhardt + Abt has already profited much from the unique and broad range of products as well as the extensive industry knowledge provided by the technological pioneers in Augsburg. Erhardt + Abt has also successfully implemented automation solutions with KUKA robots.
The automation concepts developed by roughly 75 systems engineering and robotics specialists have been implemented in the aerospace sector, the plastics industry, the food and beverage industries as well as in electronics and communications. Automotive manufacturers and suppliers, in particular, appreciate the machinery manufacturer’s expertise and take advantage of the modern engineering methods to further develop and optimize their production processes.
Full automation of the painting of rear axles
Until now, applying coating to the parts of the rear drive axle in the automotive industry was a manual and therefore very arduous and time-consuming process. Thanks to an innovative high-tech solution and a KUKA robot, automation technicians at Erhardt + Abt were able to fully automate the process.
KUKA robot gives the task the right spin
The rear axle is suspended on a conveyor system and transported synchronously into the coating booth. Two coating robots are located inside the booth, with one coating the left and the other the right side of the drive shaft. The robot just across from both of these robots then enables the real innovation: the KR 16-2 – ideal in terms of space requirements, payload, reach and explosion protection – is responsible for turning the drive shaft of the transmission.
While the rear-axle transmission travels through the booth, the robot docks onto its coupling element and turns the axle using a servomotor. The automation technicians at Erhardt + Abt have developed and built a hexagonal ball-head socket for force-fit docking. Thanks to its form – which is reminiscent of an onion dome – the function follows the principle of an Allen key with a ball head for simple and secure form-fit docking and undocking so as to ensure optimum force transmission.
For this, the robot must know the exact position of the ball head. The conveyor system runs continuously, which makes docking onto the transmission at the booth entrance (cell feed-in) more difficult. Suspension of the axles in the chain conveyor is in chaotic mode and allows movement in various directions, with even axles of the same type hanging differently. Thus, tolerances in centimeters must be compensated. Beyond this, the rear axles are manufactured ‘just in time’ for production, which means that different product series occur in an unsorted sequence.
In order to determine the varying coordinates for the docking position that result from this, an image is made of the ball head via a trigger before entry into the coating booth. These conveyor-relevant data are then communicated to the robot controller using the ExploRob image processing system. The KUKA robot then docks onto the shaft and turns it until the coating has been applied evenly over the entire surface (by both coating robots) and the rear axle leaves the booth.
Compact, versatile and flexible
The KUKA KR 16-2 – ideal in terms of space requirements, payload, reach and explosion protection – is responsible for turning the drive shaft of the transmission. The six-axis jointed-arm robot, with a payload capacity of 16 kg and a maximum reach of 1,611 mm, is particularly flexible and versatile.
Its design and weight allow for floor, wall or ceiling mounting. In the low payload range, it is particularly suitable for light activities such as measuring, testing and inspecting as well as installing and removing smaller component - not to mention handling, loading and unloading operations. Due to these characteristics, the KR 16-2 is at home in most of the manufacturing industries - including the automotive components industry.
Efficient painting process reduces strain on workers and enhances quality
The KUKA robot makes its mark in the coating booth for car rear axles through its robust motion control – even under the influence of external forces. Payload, reach, flexibility and availability as well as conveyor tracking and explosion protection classification ex works also bring further advantages.
Using the intelligent automation and cell concept from Erhardt + Abt, the strain on workers due to tough working conditions has not only been reduced, but the coating process has also been made significantly more efficient in accordance with the automotive manufacturer’s capacity requirements in 3-shift operation and the work is completed with top quality throughout.