Binding Performance of Binder (IV)
Straw Compression Pressure Acting on the Clinch Door
1974 Volume 36 Issue 2 Pages 279-289
Details
1974 Volume 36 Issue 2 Pages 279-289
The straw compression pressures acting on the clutch door of binder at the binding of sampled sheaves analyzed in previous paper (References 1 and 2) were discussed on its relation to the tightness of bound sheaf
Results obtained were as follows.
1. According to the binding mechanism and its timing action of a tested binder (One row type), the relationships between the angular movements of binding shaft θ (deg) and the straw compression pressure acting on the clutch door were investigated (Fig. 1-4)
2. The changes of the straw compression pressure F (kg) with θ (deg) measured by strain gage method had good agreements with the timing action of binding device. But the variations of F at θ were very large among samples (Fig. 7).
3. The variables PFΘ(kg/cm2) obtained from F, the door area and the unit angular movement 15°(deg) from 0° to 195°(deg) of θ were defined and calculated on each sampled sheaves. And mean values, standard deviations and coefficients of variation of PFΘ were discussed (Table 1 and Fig. 8).
4. The maximum straw compression pressures PFmax (kg/cm2) of each sampled sheaves occured at θ=160°-195°(deg) were analyzed using variance analyses.
PFmax was affected by the physical properties of straws and twines (Source of variation E (1)), the setting position of clutch door for the adjustments of sheaf size (Factor C) and its interaction with the kinds of twines (F×C) (Table 2).
The interval estimation of mean values (95%) to PFmax with the levels of Factor C were obtained as 1.38-1.04(kg/cm2) in big and middle size sheaf and 0.94-10.60(kg/cm2) in small size sheaf.
It seemed that the variation of PFmax was similar to the variation of the specific values P1 which expressed the tightness of sampled sheaves because the significance of variation sources and their contributions were the same (Fig. 9).
5. P1/PFmax of each sampled sheaves were analyzed to evaluate the binding looseness (Table 3). And the interval estimations of mean values of P1/PFmax were obtained as 55-84% in big size sheaf and 39-68% in middle or small size sheaf.
As P1/PFmax was changed with the levels of sheaf size, it seemed that the shorter the sheaf twine length the greater the binding looseness.
The effect of twine on P1/PFmax was not significant as the variation of each sampled sheaves were large.
