Reduction of cycle times in the entire production process to 30 Seconds at Zorn GmbH
When it comes to pinpoint accuracy and strong lighting systems, Zorn GmbH is almost always involved. The company based in Stochach am Bodensee has been making miniature bulbs especially designed for the medical sector for 50 years.
High-precision bulbs of this type require the highest levels of quality and reliability – down to the smallest detail. To meet the high requirements of these exceptional products, highly complex fully automated and semi-automated systems had to be developed and built specifically for production. The robots must meet the following expectations: In addition to being extremely accurate, the robots must move as fast as possible to achieve the required throughput of the line.
At the two manual workplaces, the bulbs for the lamps are inserted into specifically tailored frames, which are called boots. In the next step, the light filaments are inserted into the open bulbs from the top. The filaments themselves consist of only 0.1 mm strong tungsten filaments and the connections for the operating voltage. These connections are fixed mechanically with a glass pearl. Each boot contains 22 nests with one lamp each. The equipped boots then move into the robot cell via a lift. A laser scanner checks whether there is a bulb in every nest. Once this check is completed, the pre-assembled component is placed into a drum of the rotary table.
The piece is carried to the welding machine via the rotary table. There the bulb is joined to a separately supplied small glass tube, the so-called “pump”. An Epson SCARA robot extracts the glass bodies from the welding station with a rotary gripper.
The piece is then carried to another station for quality control. The lamp is scanned by two cameras perpendicular to each other, and it is checked whether the glass body was correctly welded and the light filament fits 100% correctly. If the movement of the bulb into the lamp testing position in front of the cameras is inaccurate, the test results may be slightly distorted due to the deviating position, leading to a large number of rejected parts and lower efficiency of the system. The integrated Epson image processing system, on the other hand, ensures precise results and minimum rejection.
Depending on the result of the last quality control, the robot places the lamps into the designated position from where they are transported to the next working step.