Operation of friction kelly bar

After the kelly bar drilling tool is installed, the drilling rig aims at the hole position and lowers the main winch. The kelly bar drops to the hole position as a whole due to its own weight, and the power head is rotated to drill. After the drill bit has completed soil acquisition, reverse the power head by 1 -2 turns to close the bucket door, raise the main winch, and lift the drilling tool from the pile hole to unload soil. When the kelly bar is lowered, when the shock-absorbing pad of the first section of kelly bar hits the buffer device of the power head, the power head holds the first section of kelly bar, and the second section of kelly bar and the remaining sections of kelly bar continue to descend under the action of gravity. , when the retaining ring of the second section of kelly bar hits the upper end of the inner key of the first section of kelly bar, the kelly bar will make a slight impact sound, and the drill will appear a slight "nodding" phenomenon (for example: 5×13 meter kelly bar, This phenomenon occurs every 12 meters or so), the second section of kelly bar stops falling, the third section of kelly bar extends, and the remaining sections of kelly bar are lowered in sequence, and so on. When the drill bit is lowered to the bottom of the hole, press the main winch to float, and the power head can be rotated to drill. After the soil acquisition is completed, reverse the bucket door and lift the main winch and power head at the same time to lift the drilling tool out of the pile hole. When the water distribution plate hits the lower end of each section of kelly bar, there will be a slight impact sound on the kelly bar. The drill will have a slight "nodding" effect.

Operation of interlocking kelly bar

When the drill bit is lowered to the bottom of the hole (the lowering of the interlocking kelly bar is the same as the friction kelly bar), press the main winch to float, rotate the power head to drill under pressure, and after the soil extraction is completed, lift the power head to the same level as the first section After the shock-absorbing pad at the upper end of the kelly bar comes into contact, press the main winch to float, so that the wire rope is in a loose rope state, and the power head is raised about 30 cm. During the lifting process of the power head, the power head continues to rotate forward to prevent the kelly bar from being drilled. The power head slips and damages the power head. The lifting of the power head stops. Reverse it quickly for 2 turns to close the bucket door. After making sure that the kelly bar is completely unlocked, release the floating button and lift the kelly bar while the power head is slowly reversing until it is completely unlocked. Propose hole locations.

When the interlocking kelly bar is equipped with a rock auger, you should pay attention when unlocking: when completing the drilling and lifting, first lift the power head forward to the shock absorbing pad of the first section of the kelly bar, and then lift it up for 20-30 centimeters, reverse the power head 1-2 turns, and lift it up after hearing the impact sound of the kelly bar. During the lifting process. The reversal speed of the power head is slightly faster than that of the sand bucket, and the lifting speed of the main roll is slower. This is to prevent the soil between the blades from falling during the lifting process of the rock auger, causing the rock auger blades to drive the innermost kelly bar to reverse and re-lock. During the lifting process, the reversal speed of the power head and the lifting speed of the main winch must be maintained at a constant speed and must not be fast or slow to avoid locking the kelly bar. If the kelly bar is found to be attached, do not unlock it in the air. Put the kelly bar to the bottom of the hole and unlock it again. After the unlocking is complete, lift the kelly bar.