| 摘要 |
<p>PURPOSE:To prevent cutting of a shear pin between a roll and an electric motor in advance by detecting load torque of a straightening roll of a rolling mill by current and number of rotation of an electric motor for roll driving and reporting overtorque by an alarming device such as a buzzer or an indication lamp. CONSTITUTION:The straightening roll 2 and its driving electric motor 1 of the steel plate rolling mill are connected by an intermediate shaft 3 having an interposed shear pin 4. Current of the electric motor 1 is measured by a shunt 7. Load torque of the roller 2 is calculated by an overtorque detector circuit 8. This is compared with rated torque for using shear pin, and when larger than the rated torque, it is judged as overtorque and detected. However, as acceleration torque and deceleration torque become necessary when the motor 1 accelerates and decelerates, rotation speed of the electric motor 1 is detected by a detector 6 and subtracted from above-mentioned comparison value. When it is judged as overtorque, an alarm is given by a buzzer 9, an indicator etc., and cutting of the shear pin 4 due to overtorque is prevented in advance.</p> |
