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Causes of drill pipe slipping down during use of rotary drilling rig
Release time:
2018-06-22
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After the current rotary drilling rig is used for a period of time, when the operating handle is returned to the neutral position during the lifting or lowering of the drill rod, the drill rod does not stop immediately, but always slides down several tens of centimeters before stopping. The drill pipe of the rotary drilling rig is caused to slip down. This paper talks about the common reasons and regular judgment of the drill pipe of the rotary drilling rig: 1. The drill pipe is fixed on the main hoisting drum through the steel wire rope, and the drill pipe can rise or fall accordingly when the drum is rolled or laid down. The power of the drum comes from the main winch motor which has been decelerated many times, and its stop is realized by the brake directly installed on the reducer. in the drill pipe
After the current rotary drilling rig is used for a period of time, when the operating handle is returned to the neutral position during the lifting or lowering of the drill rod, the drill rod does not stop immediately, but always slides down several tens of centimeters before stopping. The drill pipe of the rotary drilling rig is caused to slip down. This paper talks about the common reasons and regular judgments of the drill pipe of the rotary drilling rig:
1. Cause of failure The drill pipe is fixed on the main hoisting drum through the steel wire rope. The drill pipe can rise or fall accordingly when the drum is rolled or the steel wire rope is laid. The power of the drum comes from the main winch motor which has been decelerated many times, and its stop is realized by the brake directly installed on the reducer. In the process of lifting or lowering the drill pipe, if the operating handle is returned to the neutral position and the drill pipe cannot be stopped quickly, there may be three reasons: one is braking lag; The second is that the two hydraulic locks at the end of the motor fail, and the motor cannot stop rotating immediately under the action of the wire rope torque. The third reason is easy to be ignored. All drilling rigs have a drill pipe release function, this function is to provide the release brake signal oil by the solenoid valve 3, and then the solenoid valve 2 is connected to the oil inlet and outlet of the main winch motor through two oil pipes, so as to ensure that the drill bit can always contact the working surface during the drilling process and have a certain pressure. Under other working conditions, the solenoid valve 2 will disconnect the two oil pipes leading to the motor inlet and outlet ports. If the disconnection is not timely, the above failure phenomenon will occur.
2. Judgment method
(1) Judge whether the solenoid valve is closed tightly: remove the two oil pipes leading to the solenoid valve at the motor, block the two oil ports at the motor end with two plugs respectively, and then operate the main hoisting mechanism. If it works normally, it indicates that the solenoid valve 2 is not closed tightly. If it is still abnormal, its components must be checked.
(2) judge the hydraulic lock to determine whether there is a problem with the hydraulic lock: first adjust its two lock cylinders, if it does not work, then remove the lock for careful inspection, if you can not find the reason, you can use the ready-made lock to do the installation test to find out the cause of the failure. Because the hydraulic lock of the auxiliary winch is the same as that of the main winch, it can also borrow the lock of the auxiliary winch and identify the quality of the main winch lock by replacing it one by one. If there is no problem with both locks, proceed to the next check.
(3) Judge the brake signal oil and check the speed of the brake signal oil supply and cut off: the current drilling rig, the flow of the signal oil can be adjusted, that is, the time for the main hoist to release the brake can be adjusted. Therefore, for the two types of drilling rigs, the flow rate of signal oil can be adjusted through its regulating valve. If the working condition of the machine is still abnormal, it is necessary to check whether the oil pipe of brake signal oil is blocked. If these parts are normal, only continue to check.
(4) to determine the brake disassembly brake: to see whether the brake piston in the work line to move smoothly, for the cause of the failure to repair or replace.
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