Torque detecting apparatus
A sensor coil serving as a sensor unit fitted and retained in a sensor retaining hole of a sensor housing and a circuit board stored in a board chamber provided inside the sensor housing are integrated by coating the outer surface of a lead and the circuit board with a resin layer formed by resin molding performed under the condition in which the sensor coil and the circuit board are connected with the lead. As a result, mounting of the sensor unit and the circuit board of a torque detecting apparatus in the housing is facilitated, the reliability of the connection part of the sensor unit and the circuit board is increased, and occurrence of connection defects due to the function of external force is prevented.
1. A method of forming a torque detector comprising the steps of:
providing a housing having a first chamber for receiving a sensor and a shaft, a second chamber for receiving a circuit board and a passageway connecting the first chamber and the second chamber;
connecting the circuit board to the sensor with a connection part to form a unit;
coating the unit including the circuit board, the sensor and the connection part with synthetic resin; and
sliding the unit into the housing so that the sensor slides into the first chamber, the circuit board slides into the second chamber and the connection part slides into the passageway.
2. The method of claim 1 including the additional steps of:
passing a shaft through the first chamber;
detecting a torque applied to the shaft; and
producing an output from the circuit board to an external device indicative of the torque applied to the shaft.