Blasting at 16 second intervals
With this solution, a robot alternately loads two blasting plants. This procedure enables the required redundant design of the blasting process, and it prevents production standstill in the case of a plant breakdown.
The plant manufacturer achieves the specified, short cycle time of just 16 seconds per workpiece with a double gripper, with which the robot can accept two workpieces at once. The cylinder heads are delivered to the robot cell via a roller conveyor with side transfer unit. The cylinder heads are prepared in the precise position by an alignment system for acceptance by the robotic gripper.
In the blasting plant, the duplex gripper positions the cylinder heads on part-specific, designed workpiece mountings and then pulls out of the blasting chamber again. After closing the chamber door, the turbine bulkhead releases the inflow of blasting abrasive, and at the same time the cast parts are set in rotation via the workpiece mountings.
This continual changing of position guarantees that the cylinder heads are blasted on all sides, evenly and without shadow effects. Stainless steel is used as a blasting abrasive, in a grain size of 0.5 to 0.8mm. After the specified blasting time, the bulkheads close the turbines again, while the workpiece mountings continue to rotate until the blasting chamber is completely open. This means that the workpieces are pre-emptied in the blasting chamber.
Each blasting plant is fitted with a total of four high power turbines, type Hurricane H42 with a diameter of 420 mm and a drive power of 15kW each. Rösler determined the optimum placement and required inclination angle of the turbines in the construction phase, through 3D simulations of the blasting process.
In order to prevent extreme strain due to the high blasting intensity, the plant casings and workpiece mountings are made from extremely hard wearing manganese steel. In addition, the work chambers are clad with 12mm thick, gap-free laid manganese steel plates.