unternehmen & trends DIGITAL

BOMAG GmbH www.bomag.com Websites Yaskawa Europe GmbH www.yaskawa.eu.com Unternehmen & Trends  39 All-round satisfaction with the new system: Harald Aßmann, team leader at the drum factory, and pro- grammer Dennis Anton. The belt grinder follows the contours of the drum. Optimally stowed: The tool changer is also acces- sible from the outside and covered by a flap during operation. In the first step, the robot measures the weld seam using a laser measuring device. The orbital sander polishes the weld seams on the inside of the drum. Bomag single drum roller production facility, in which the drum is placed by crane on a ro- tating device also manufactured by Yaskawa, whereby the weld seam must be in the ”12:00 o‘clock position“. The operator starts the program and closes the enclosure. In the meantime, the robot, a large, six-axis MOTOMAN MH180, has already removed a laser measuring device from the tool changer and is measuring the weld seam very accurately in the first step. The robot does not move linearly, but in a pendulum motion along the contour of the drum in order to record the weld seam three- dimensionally. Second and third step: Grinding of longitudinal seam and side plate The data generated by the measuring device are used as the basis for the subsequent processing step. The robot changes to a belt grinder and moves over the weld seam ten to twelve times. The current consumption of the robot serves as a parameter for the pro- cessing quality: When enough material has been removed, the grinding tool must apply less pressure and the machining process can be completed. Material is also removed at the base, i.e. at the edges of the drums. Even during grinding, the MOTOMAN MH180 performs a non-linear movement to machine the weld seam’s complete contours. In addi- tion, the device also rotates. Harald Aßmann: ”This way we save space: Although the robot has a very long reach, it cannot cover the en- tire length of large roller drums“ The rotary movement is also required for the third step. Here, the powerful robot puts down the belt grinder and uses an orbital sander to polish the weld seam that joins the side plates and the outer shell of the drum. The result of the robot-assisted polishing in three steps is a perfectly flat weld seam that fits perfectly into the rounding of the drum and a clean connection between the side plate and drum. One of the special features of the ”polishing robot“, as it is called at Bomag, is the tool tray, protected by a lid, which only opens automat- ically when tools are changed. This keeps the tools clean. The MOTOMAN MH180 itself is protected from dust and flying sparks by a sheathing – a purely precautionary measure, because the powerful suction system re- moves almost all sparks. Polishing without losing any time and with high flexibility What is beneficial from the productivity point of view?: This step takes place without any loss of time. Harald Aßmann: ”The polishing is done parallel to the holes being drilled in the side plates.“ And the plant, which has been running for around six months, is also flexible. Dennis Anton, responsible for pro- gramming the cleaning robot: ”So far we have written programs for almost 40 types of drums with diameters up to over two meters and different lengths.” The Bomag managers are also satisfied with the course of the project. Small ”special re- quests“ were also taken into account on site. Dennis Anton suggested that the existing pneumatic line in the robot be used to blow out welding beads and grinding residues from the inside of the drum in the final work step. All in all, Bomag considers the new robot to be an exemplary automation project. Harald Aßmann concludes: “We have increased our level of efficiency because our colleagues no longer have to sand and polish manually. This also reduces the physical strain on employ- ees, who can devote themselves to more de- manding tasks during this time.“ In addition noise and dust emissions have been reduced throughout the drum factory. ■