| 摘要 |
<p>PURPOSE: To improve cutting accuracy and reliability by monitoring the speed of a motor driving a rotary cutter bar mechanism, and controlling the motor to return to a prescribed speed when change of the motor speed is detected. CONSTITUTION: The speed of a motor 60 driving a rotary cutter bar 44 is continuously measured by a tachometer 62, and it is sent to a speed control circuit 64. The speed control circuit 64 makes an error signal by an error compensating circuit 72 through a dc conversion/filtering circuit 70. Namely, the error compensating circuit 72 compares operation speed input from a cutter operation circuit 74 with the detected speed to obtain the difference. If there is an error, the error signal 80 is sent to the motor 60, and the speed of the motor 60 is returned to the fixed operating speed. An electronic stop protection circuit 76 protects the motor 60.</p> |
