Patent ID: 8248193

Claim:
An electromagnetic switch for an auxiliary-rotation starter, comprising: a case that serves as the outer frame of the electromagnetic switch and forms a magnetic circuit; a core fixed on one end of the case; a plunger that faces the core by the intermediary of an air gap and protrusively moves from the other end of the case; and a bobbin that is disposed inside the case in such a way as to enclose part of the core and the plunger and around which an attraction coil and a holding coil are wound, wherein a magnetic bypass core for bypassing part of magnetic flux that heads for the core from the plunger is disposed inside part of the bobbin so as to secure an air gap between the outer circumference of the plunger and the magnetic bypass core, and to secure another air gap between the core and the magnetic bypass core, wherein a core side end of the magnetic bypass core is disposed closer to the core than a core side end of the plunger.