Sensors and transducers in die casting and more

The compact design of Micro-Epsilon eddyNCDT 3005 sensors mean they can integrate into existing machines.

Sensors and transducers for motion designs and relatedsystems abound. Consider the monitoring of mold deformationsin aluminum die-casting. Here, inductive eddyNCDT displacementsensors from Micro-Epsilon use eddy currents to track gaps inaluminum die-casting processes.

These precision sensors increase the service life of the tools involved and product quality, while rejects and expenses are reduced. Their robust sensor design also enables gap measurements in harsh ambient conditions. In the production of aluminum die-cast parts, liquid aluminum is pressed into a mold under high pressure. The two mold halves must be held together with significant force. Despite this high contact force, the tool halves are pressed apart minimally. This process is also called mold breathing. Although minimal openings are normal and intended during this process, a gap causes fraying on the component if it is too large. These splinters must be reworked to meet the high quality requirements of the final product. If aluminum residues remain on the tool, they also lead to increased wear, which reduces tool life.

Monitoring tool deformation using inductive displacement sensors based on eddy current enables high product quality combined with improved tool life and reduced rework. Usually, three to four eddyNCDT 3005 eddy current systems are used to ensure consistent gap monitoring at several measuring points.

A system consists of a compact and robust controller, which together with the cable and sensor form a unit. The integrated system design increases robustness and resistance to external factors, making the system insensitive to high temperatures, dust, dirt or pressure, and delivers accurate results regardless of the environment.

CLAMPING CONTROL WITH SENSORS

Consider another application of sensors in die casting as well as injection molding. During these additive-manufacturing processes, the mold is clamped together to resist the rapid thermal expansion and contraction caused by the molten material filling the mold cavity. Flawed parts can be created if the mold is not kept properly clamped to resist thermal loadingthroughout the molding and casting process. To mitigate these thermal effects, some designs include pancake load cells at the clamp contact points — enabling a machinery monitoring processes to adjust clamping forces.