Core of solenoid actuator

DETAILED DESCRIPTION It is an object of the invention to provide a core of a solenoid actuator, which is improved in durability, and at the same time ensures high energy efficiency of the solenoid actuator.
To attain the above object, the present invention provides a core of a solenoid actuator, for attracting an armature during operation of the solenoid actuator, comprising: a plurality of core plates made of a magnetically soft material and stacked in a predetermined direction orthogonal to a direction of attracting the armature to form a laminated stack, for forming magnetic circuits between the armature and the core plates themselves during the operation of the solenoid actuator; two core holders formed of a non-magnetic material and sandwiching the laminated stack of the plurality of core plates from opposite sides along the predetermined direction; an insulator interposed between each adjacent two of the plurality of core plates, for insulating the each adjacent two core plates from each other; and fixing means rigidly securing the plurality of core plates and the two core holders to each other to form a unitary assembly.
According to this core (including a yoke forming a magnetic circuit between the armature and the yoke itself) of a solenoid actuator, a stack of the plurality of core plates sandwiched between the two core holders is fixed by the fixing means to form a laminated stack.
The plurality of core plates are stacked in the predetermined direction orthogonal to the direction of attracting the armature, in a state insulated from each other by the insulators, a magnetic circuit is formed between each core plate and the armature during the operation of the solenoid actuator, and at this time, an eddy current is generated in each core plate.
However, since the core of the invention is formed by the plurality of core plates each of which is thinner than an ordinary solid core, the eddy current generated in each core plate disappears more promptly than in the solid core.
Moreover, since the two core holders at the opposite ends of the core are formed of the non-magnetic material, magnetic fields are not readily generated between the core and magnetically soft components around the core during operation of the solenoid actuator, which contributes to reduction of energy loss