| 摘要 |
<p>Crop processing apparatus comprising crop processing means (18, 23, 24) driven by drive means (29) and an automatic control system comprising sensor means (50, 51) for sensing transmission loss in the drive means (29) and producing a corresponding transmission loss signal which is proportional to the load exerted by crop on the crop processing means, setting means (Sr) for selecting a desired level of crop load and producing a reference crop load signal (Sr) corresponding to a selected level of transmission loss, signal processing means (13) which compares the transmission loss signal with the reference crop load signal to produce a control signal (Se), and actuator means (14) that is controlled in accordance with said control and is effective to vary the rate of feed crop to the processing means to maintain a substantially uniform load of crop in the crop processing means. The transmission loss takes the form of relative rotation or slip between input drive and output driven shafts (31, 33). Preferably, the drive means comprises a driven belt (34), and belt slip is used as a measure of transmission loss. The belt slip in the belt drive to a crop treshing cylinder is preferably used as the control parameter. The sensor means (50, 51) measures the rates of rotation (Sb, Sc) of the input drive shaft (31) and output driven shaft (33, 36) and the signal processing means (13) calculates the ratio of said rates of rotation to determine belt slip. This belt slip value may be normalised using values of the rate of rotation (Sbn, Scn) of two shafts measured under standard, no-load conditions. The actuator means (14) may be the forward speed controller of a combine harvester.</p> |
