Requirement:
- Complete machining of welding electrodes (turning, milling, grinding) in a single machine.
- Material: Copper-backed tungsten – highly abrasive, difficult to machine.
- Automated production via pallet changer table with robot.
- Continuous measurement and automatic feedback for dimensional correction.
- Automated cleaning of components to prevent contamination
- Integration into the customer's central water-water cooling system
- Safe operation thanks to oil cooling and integrated fire protection system
- Sorting into good, NIO and SPC components
- Gentle handling thanks to plastic grippers and adjustable gripping pressure
Considerations:
- Components are stored in specially manufactured pallets that can be reused by the customer in the subsequent process (e.g. washing).
- Two levels in the pallet changer: one being processed by robots, one being loaded by workers.
- The clamping concept must be stable enough for both grinding and milling.
- Gripper with interchangeable plastic fingers and adjustable pressure for sensitive components. However, no clamping marks may be visible on the components.
- The measuring probe must not only measure, but also automatically process the data for correction.
- The blow-off station must be sealed airtight to prevent oil and chips from being carried away.
- Fire extinguishing system required due to oil cooling.
Solution:
The system is based on a SPINNER TTS with an integrated pallet changer. Machining (turning, milling and grinding) is carried out in a single clamping. The welding electrodes are made of copper-backed tungsten. The combination of soft copper and hard, brittle tungsten poses a challenge during machining. By combining several machining processes in one machine, maximum precision can be achieved and the components can be machined effectively – supported by automatic measurement in the machine and feedback of the measurement data for correction.
The workpieces are provided in customer-specific pallets. A two-level pallet changing table enables uninterrupted production: while one side is being processed by the robot, the other side can be reloaded by the operator. The pallets are also designed for component cleaning.
A robot with a pneumatic double centric gripper handles the workpiece. The gripper fingers are made of plastic to prevent damage and clamping marks. The pressure on the finished part gripper can be individually adjusted. The component can also be turned in a turning station if the machining strategy in the machine requires it.
After machining, each workpiece is cleaned with compressed air at a specially sealed blow-off station. This reliably prevents the carryover of coolant or dirt. The blow-off station is automatically sealed by the robot gripper during the cleaning process.
Defective parts (NIO) and components for statistical process control (SPC) are automatically ejected. The storage locations are modular in design and can be converted without tools.
The machine is connected to the customer's central water-water cooling system. As the machining is carried out with oil, a fire extinguishing system had to be installed in the machine so that the oil can be extinguished safely in the event of a fire.
