Tripping device of circuit breaker

A tripping device of a circuit breaker for receiving control power from a control circuit unit to allow a stationary contact point and a movable contact point to be brought into contact with or separated from each other to control power supply to a load, the tripping device comprising:

• a housing formed with a mounting space to which an actuator is mounted and fixed at one side thereof;
• the actuator mounted and fixed to the mounting space, and configured with a yoke portion configured to receive control power from the control circuit unit to form a main magnetic flux path, a bobbin wound with a coil and attached to a permanent magnet, and a magnetic force reinforcing plate adhered to the bobbin to reinforce a magnetic force formed on the main magnetic flux path;
• a first cover formed with a first support fixture inserted into the other side of the housing, and adhered to the magnetic force reinforcing plate at one side thereof to maintain a state that the magnetic force reinforcing plate is adhered to the bobbin;
• and
• a second cover formed with an opening portion configured to be opened to insert the control circuit unit therein at the other side of the housing, and detachably adhered to the other side of the housing to close the opening portion to prevent the control circuit unit from being exposed to the outside.