| 摘要 |
A hard foreign body in a stream of cut crop being moved by a conveyor in an agricultural machine to a crop comminuter of the machine is detected by first compressing the stream of cut crop transversely of its displacement direction between a pair of feed elements one of which is movable toward and away from the other and generating an actual-value output corresponding to the acceleration of the movable element toward and away from the other element. This output is compared with a set point corresponding to an acceleration level not normally exceeded by the element when the crop stream contains no hard foreign objects. An error signal is generated when the actual-value output exceeds the set point. When the error signal is issued advance of the conveyor is stopped and/or a warning is issued. The actual-value output is only generated when the acceleration of the movable feed element exceeds a predetermined limit. The actual-value output is a voltage and the set point is also a voltage. |
