| 摘要 |
PURPOSE:To simplify a device and form a maintenance-free system by abating the inclination of the deceleration line of a line motor immediately before it comes to a stop and reducing an exciting current for compensation to a value suited to the abated inclination of the deceleration line of said line motor. CONSTITUTION:As a stopping operation is carried out, a relay contact Ry3 is thrown in. Since a ramp generator 11 lowers a target speed signal 11a at a steep inclination, a line motor LM is also rapidly decelerated following the deceleration line. On the other hand, the inertia compensatory signal 26a of an inertia compensator 26 is inputted in an adding point 23 and an exciting current for compensation corresponding to it is added to the exciting current iHB of a hysteresis brake HB. Accordingly, the hysteresis brake HB generates a large braking torque. And, by keeping the value of the braking torque at this time suited to the inclination of the deceleration line of the line motor LM, the tension of a workpiece can be maintained constant preventing unnecessary loosening.
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