Design of a hybrid electromagnetic switching/holding solenoid with adjustable core

Abstract:
Despite their long existence and diverse use as electro-magneto-mechanical energy converters, electromagnets continue to offer development potential and are indispensable. They are therefore of utmost importance in many areas of technology. For example, they perform critical switching and positioning tasks in relay and valve technology. Due to increased requirements and technological progress, in some cases the classic electromagnet must be further developed. For example, conditions are placed on an adjustable force-air gap characteristic of the moving armature and, at the same time, low-noise operation is demanded. The hybrid solenoid presented here tries to meet these requirements with a magnetically adjustable inner plunger, which actively shortens the air gap to the external armature during the switching process and thus influences the force-displacement characteristic as well as the current-air-gap correlation. A hybrid switching/holding solenoid which uses magnetic shape-memory-alloys (MSM) has already been developed at IKFF. These MSM-alloys are to be dispensed in the solenoid presented here by means of an appropriate design of the magnetic circuit to expand the range of applications.