抄録
Capacity of smashing soil using power tillers is lighter than that using Japanese plow. Surveying smashing soil using power tillers, Rotary type is the highest, Screw type next, and Crank type is the worst.
2. In short, the shape of soil when Rotary type is used makes nearly round, which makes like brick style when crank type is used; which does flat tri angle when screw type is used.
3. On the point of distribution and arrangement of soil on cultivated land we found large block of soil on upper part and small on lower part when power tillers are used.
4. Reverse turning of soil is remarkably better when Japanese plow is used than when power tillers are used.
Differences by power tiller are not large.
5. Cultivated board is made most uneven and rough when crank type is used; which is made plain and smooth when screw type is used; when is made intermediate of them when Rotary type is used.
6. Construction elements of operation of smashing soil by power tillers:
1. Rotary type:
a) Set up soil by pawring.
b) Centrifugal throwing.
c) To collide with reflection board.
d) To collide with clod.
2. Crank type:
a) To prick and to raise.
b) Throwing by repulsion.
c) To solid with reflection board.
3. Screw type:
a) To cut and to raise.
b) Centrifugal throwing.
c) To collide with screw blade.
d) To collide with clod.
