| 摘要 |
In a forage harvester, a microphone is used to detect air-borne sounds waves generated by impacts of a rotating cutterhead on a shear bar during adjustment of the shear bar relative to the cutterhead. In response to the detected sound waves, the microphone produces electrical output signals which are applied to a control circuit, the control circuit producing output signals to selectively drive first and second motors to move one end or the other of the shear bar. The microphone may be mounted in positions remote from the shear bar, such as on side sheets defining lateral limits of the crop feed path, or in the interior of a crop feed roll. A vibration absorbing pad is provided between the microphone and its support to isolate the microphone from mechanical vibrations of the support. In one embodiment the microphone serves not only to detect air-borne sound waves generated by impacts of a rotating cutterhead on a shear bar, but also to detect the air-borne sound waves generated by impacts of stones and other hard objects on the crop feed mechanism.
|
