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Maintenance knowledge of down-the-hole drilling rig

October 18, 2021

1. Installation of the unit:
① Prepare the rock drilling space. The size of the space can be determined according to the type and method of drilling.
② Lead air and water (when water is needed for dust removal) pipelines, lighting lines, etc. to the vicinity of the working point for later use.
③According to the requirements of hole position design, ensure the reliable positioning of the drilling rig.


2. Inspection before homework:
① When starting work, carefully check whether the air and water (when water is needed for dust removal) pipelines are firmly connected, especially the connection between the wind and water pipe joints and the wind and water pipes must be firm to prevent tripping and injury. Air leakage and water leakage.
②Check whether the oil mist device has been filled with organic oil (it should not be filled too much).
③Check whether the screws, nuts, joints, etc. of each part have been tightened, and whether the various positionings are firm and reliable.


3. Drilling procedure and unloading method:
①When opening a hole, first drill with a small impact energy, propulsion force and low speed to facilitate the positioning of the drill bit. (When dust removal is required, give a proper amount of water to reduce dust) When the drill bit is drilled about 10 cm, Then use the full air door impact, and appropriately increase the propulsion force, increase the speed (to keep the air-water mixture in an appropriate ratio when dust is required), and perform normal rock drilling. After drilling a drill pipe, stop the operation of the air motor and stop the feed. The impactor sends air and water, inserts the fork into the drill pipe slot of the drill holder, makes the wind motor reverse, the sliding plate moves backward, and the joint is separated from the drill pipe, and then the second drill pipe is connected for drilling, and so on.
②Rod unloading method: This drill rod unloading is carried out semi-automatically, which is realized by the cooperation of the rod unloader, the drill holder and the reversal of the two forks and their air motors. When unloading the rod, the rotary machine moves backward. When the second groove of the drill pipe (the groove at the middle of the drill pipe end) is directly opposite to the square frame of the bracket, use a fork to insert the second groove firmly, and then reverse Motor, when the square frame of the rod unloader and the first groove of the drill pipe (the groove on the end of the drill pipe male joint end of the drill pipe) are directly opposite, use the second fork to insert it firmly, and take out the first fork (square bracket The fork in the frame), manipulate the propulsion cylinder to make the rod unloader drive the drill rod to move backward, when the second slot of the second drill rod is aligned with the bracket slot, reverse the motor, when the screws of the two drill rods After the buckle is released, remove the first drill rod, and then remove each drill rod in turn.


4. Matters needing attention in operation:
①At any time, check the connection of the screws, nuts and joints of each part of the air and water (when dust is removed with water) and the fastening of the frame and the host.
②At any time, observe the working conditions of the lubricator and check the lubrication of the wind motor and impactor.
③ Regularly clean the impactor and wind motor with gasoline or diesel, and observe the damage of the motor blades.
④Reverse rotation is not allowed when drilling to prevent the drill rod from tripping.
⑤When the machine stops working in a short period of time, give a small amount of air pressure to avoid mud and sand from entering the impactor. If it stops working for a long time, the impactor needs to be lifted to a distance of 1-2 meters from the bottom of the hole. Fix it again.
⑥ During the work, pay attention to whether the sound of the impactor and the operation of the machine are normal. If any abnormal phenomenon is found, the machine should be shut down immediately for inspection.
⑦; When adding a new drill pipe, pay special attention to the cleaning of the drill pipe to avoid sand mixing into the impactor to damage the parts or cause a shutdown accident. (Usually use compressed air to blow and wash several times).
⑧When there is water on the working surface, use a large-diameter drill bit to open the hole, and then insert the casing, and make the casing 100-200 mm long to expose the ground to prevent slag mud from entering the hole.


5. Machine maintenance and lubrication:
①At the end of each work shift, the dirt on the surface of the machine must be removed.
②It is strictly forbidden to dismantle and unload it on the working surface (except when disassembled into components for easy transportation), so as to avoid losing other parts and damaging the key parts of the other parts.
③Fill the lubricator with oil regularly to ensure that the control valve, wind motor and impactor have good lubrication.
④The gearbox is lubricated with a mixture of calcium-based grease and engine oil. Lubricants should be added regularly. It is appropriate that the lubricant occupies 1/3-2/3 of the box gap to ensure the lubrication of the gearbox.
⑤In the propulsion joint part, due to the relative movement of the sliding plate and the sliding frame, the sliding frame and the pressure plate and the sliding plate can be worn. For slight friction, the adjustment pad under the pressure plate can be removed. When the friction is heavy, the pressure plate, sliding plate or sliding frame can be replaced. To ensure high drilling accuracy.



Common troubleshooting
1. Broken drill pipe:
① Most of the drill pipe fractures are caused by friction between the drill pipe and the hole wall, which reduces the thickness of the drill pipe wall and weakens the strength too much, causing the drill pipe to break.
②Preventive treatment: pay attention to inspection when adding drill pipes, and stop using drill pipes with excessive wear.


2. The impactor does not sound:
① There are four common situations: (1) The valve is broken; (2) The broken ballast at the tail of the drill bit enters the cylinder block and jams the hammer body; (3) The exhaust hole is blocked by rock dust; (4) When chiseling, there is a lot of water in the hole and the exhaust resistance is large, and the impactor is not easy to start.
② Treatment method: When the impactor does not sound, check according to the above four reasons; the check method is to raise the impactor for a while, reduce the exhaust resistance, spray a part of the water, and then slowly push it to the bottom of the hole. When this method does not work, it is likely to belong to the first three reasons, and the impactor needs to be removed for cleaning or replaced.


3. Stuck
1-  In addition to the complex formation that can cause the machine to jam during normal drilling, there are also the following reasons: ①. The drill bit has broken wings; ②. The new drill bit is larger than the original diameter; ③. The machine is displaced during rock drilling. As a result, the drilling tool is deflected in the hole; ④. Rocks fall from the hole wall or opening or encounter large cracks or caves during rock drilling; ⑤ When there is a broken zone with yellow mud and broken stones, the rock dust cannot be discharged; ⑥. Negligence in operation. When the drilling was stopped for a long time, the rock dust was not blown off, and the drilling tool was not lifted, so that the impactor was buried by the rock dust.
2-  Processing method: As far as the strength of the current drill bit is concerned, the broken wing has been basically eliminated. In case of special circumstances, the rock dust at the bottom of the hole can be blown off first, and then a section of seamless pipe with a diameter similar to the hole diameter can be installed inside. Filled with butter or asphalt, connect the drill pipe to the bottom of the hole, and take out the broken wing at the bottom of the hole. When encountering the last five stuck drills, the more serious situation is that the drill cannot be lifted and cannot be put down. The wind motor does not rotate and the impactor does not sound. At this time, the only way to turn the drill tool is to apply torque or use auxiliary tools to help lift it, and then lift the drill tool while air is being supplied until the fault is eliminated. When re-drilling the rock, apply pressure first, and then gradually increase to normal working pressure.


4. Bit fragments, corners, and chips:
① When the drill pipe is bounced, it may be the exchange place of the change of the rock formation or the stone block or the alloy sheet has fallen into it. Judging from the appearance, if the alloy sheet is dropped, the footage can hardly be taken, and the drill pipe beating is more rhythmic.
②When it is confirmed that the alloy piece has been dropped, the drill tool can be lifted to blow out the alloy block with a strong blowing method. When it cannot be blown out, it can also be taken by treating the broken wing of the drill bit, such as when there is a fault or broken zone in the hole. , Squeeze the alloy into the wall of the hole in these places, or not take it out, replace the drill bit and continue drilling.


5. Precautions for the use of wind motors:
①Before connecting the motor and the hose, the hose should be cleaned carefully. You can open the air valve of the pipeline for a few seconds, and then blow the hose with compressed air before connecting.
②The connection between the motor and the hose must be firm.
③Before operation, it is necessary to ensure that the lubricator has lubricating oil and the lubricating oil path is unblocked. It is not allowed to work in the absence of lubricating oil.
④ When the motor is found to be running abnormally, stop work immediately and perform maintenance. It is forbidden to dismantle and unload on the working surface.