1.            Overview

    The high wind pressure impactor is a percussive rock drilling tool, but unlike other rock drilling tools, it always stays at the bottom of the hole during the rock drilling process, and the piston directly impacts the drill bit. The compressed gas enters the impactor through the drill pipe, and then is discharged from the drill bit. The exhaust gas is used for slag removal. The rotary motion of the impactor is provided by the rotary head of the drilling rig, and the axial thrust is provided by the propulsion mechanism of the drilling rig, and is transmitted to the impactor through the drill rod. Reasonable and timely maintenance and maintenance can extend the service life of impactors and drill bits and reduce operating costs.

Second,            structural principles

  The down-the-hole impactor is composed like this: piston, inner cylinder, valve seat, one-way valve, and drill accessories are installed in a slender outer sleeve, and the upper end of the outer sleeve is equipped with a wrench port and a connection The threaded rear joint, the lower end is equipped with a threaded front joint. The front joint is mainly used to transmit propulsion and rotary motion to the drill bit. The snap ring controls the axial movement of the drill bit, and the one-way valve is used to prevent debris and other debris from entering the impactor when the supply of compressed air is stopped. During the drilling process, the drill bit is pushed into the impactor and pressed on the front joint. At this time, the piston directly impacts the drill bit for rock drilling. When the drill bit is lifted from the bottom of the hole, blow the slag strongly.

Three,            Precautions for use and operation

1. To ensure reliable lubrication, the reasonable lubrication of the impactor can never be ignored, otherwise it will accelerate the wear of the impactor and even cause damage. The lubrication of the impactor is realized by the oil injector on the drilling rig. The lubricating oil is sprayed into the high-pressure gas through the oil injector, and the gas is used as the carrier to enter the impactor, so as to realize the lubrication of the internal parts. The amount of lubricating oil can be adjusted by adjusting the opening of the oil injector valve. The amount of lubricating oil should be moderate, large amount will cause waste; small amount will cause poor lubrication effect. During the process of unloading the drill rod, observe the adhesion of the oil on the inner wall of the drill rod. Therefore, it is necessary to always ensure that there is sufficient lubricating oil in the lubricator during work. (No. 20 machine oil in summer, No. 5-10 machine oil in winter)

2. Before the impactor is installed on the drill pipe, operate the impact air valve to remove the debris in the drill pipe and check whether the drill pipe has lubricating oil. After connecting the impactor, check whether there is an oil film on the drill bit spline, if it is obvious If there is no oil or the amount of oil is too large, the oiler system should be adjusted.

3. When the impactor starts to drill, you should manipulate the advancing air valve to make the impactor move forward, against the ground, and open the impact air valve to make the impactor work. At this time, you should be careful not to rotate the impactor. Otherwise, it is impossible to stabilize the drill. When a small pit is impacted to stabilize the drill, open the rotary air valve to make the impactor work normally. When opening the hole, the minimum impact and propulsion force should be used to make the drill stable. Enter the rock formation.

4. During the work, check the air compressor tachometer and pressure gauge regularly. If the speed of the drilling rig drops rapidly and the pressure increases, it indicates that the drilling of the drilling rig is malfunctioning, such as the collapse of the hole wall or the formation of mud hoops in the hole. Measures must be taken to eliminate them in time.

5. Always keep no slag in the hole during the drilling process. If necessary, perform a strong blow to clear the hole, that is, lift the impactor 150mm from the bottom of the hole, then the impactor stops impacting, and all the compressed air passes through the center of the impactor Hole for slagging.

6. If you find that the drill bit has dropped or the fragments have fallen into the hole, you should use a magnet to suck it out in time.

7. In order to improve the drilling efficiency of the drill bit, it is possible to regularly grind the drill bit studs, but the grind drill bit is more prone to non-quality problems (the drill bit will not be compensated after the drill bit is reground). Please pay special attention to the user.

8. Pay attention to the diameter change when replacing the drill bit. The worn hole of the drill bit has not been drilled. It is not possible to replace the old drill bit with a new drill bit to avoid "jamming".

9. High-efficiency drilling and improving the service life of the drill bit depend on the proper coordination of axial pressure and rotational speed. Various rock formations will affect the ratio of speed and axial pressure. The lowest axial pressure applied to the impactor is that the impactor does not produce rebound (ie drilling rig vibration) when the impactor is working. The speed can be adjusted according to the particle size of the slag. The rotating speed usually used by the impactor is generally 15—25rpm. The faster the speed, the faster the chisel speed, but in hard rock, the speed should be reduced to ensure that the drill bit is not excessively worn.

10. Because the front and rear joints of the impactor are both right-handed threads, during drilling, the impactor should always be turned to the right to prevent the impactor from dropping a hole.

11. When drilling down holes, when stopping drilling, do not immediately stop supplying air to the impactor. Drill should be carried out for strong blowing, and then stop until there is no more slag and rock dust in the hole. Wind, and then put down the drill to stop turning.

12. During the connecting process, rock debris and various impurities will fall into the impactor, so the threaded end of the loose drill pipe must be covered to ensure that the drill pipe does not stick to rock ballast and dust.

Four.            repair and maintenance

Under normal rock drilling conditions, the impactor should be overhauled, cleaned and reassembled. Normally, it should be carried out every 200 hours of work, and once every 100 hours when drilling water holes or slagging with mud.

The disassembly of the impactor: Generally, it is carried out on a special disassembly workbench for the impactor. If there is no corresponding workbench, you must pay attention to the protection of the impactor itself.

Five.            cleaning, testing and repairing

1. Thoroughly clean all the removed parts with cleaning agent, and blow dry with high-pressure air.

2. Check and repair all parts of each part. If there is bumps and scratches, use files, scrapers, fine oil stone, etc. to polish and repair.

  Complete, (piston parts can be stuck on the lathe for grinding) If cracks and breakage occur, they should be replaced.

3. Use a micrometer and an inner diameter gauge to measure the outer circle of the piston and the inner diameter of the cylinder. If the fit clearance is too large, replace one.

  New piston or cylinder.

4. Check the wear of the front joint, and replace it with a new one when the outer circle is worn to be smaller than the outer diameter of the outer tube.

5. Check the wear of the spline of the front joint, insert a new drill bit into the spline of the ferrule to twist, if the rotation range exceeds

  5mm should replace the front connector.

6. Lubricate all parts of the repaired parts and all parts to be assembled.

VI.            Assembly of impactor

1. Stand the lower end of the outer tube up on the ground, put the small head of the guide sleeve down into the outer tube (note the direction), and knock it in place with a copper rod.

2. Put the big end of the drill bit down on the ground, coat the inner thread of the outer tube with a layer of butter, put the large outer circle of the clamp sleeve down into the drill bit, and put the “O” ring on the snap ring to lock the snap ring At the small outer circle of the drill bit, the drill bit, the clamp sleeve, and the clamp ring are screwed into the outer tube.

3. Put the outer tube with the drill bit on the workbench, use the copper rod to drive the valve seat into the inner cylinder, and the piston into the inner cylinder, one

  The block is pushed into the outer sleeve from the upper end of the outer sleeve. And knock it in place with a copper rod.

4. Put in the spring and check valve to see if the check valve is free to move.

5. Coat the inner thread of the upper end of the outer sleeve with a layer of lubricating oil (butter), and screw the rear joint into the outer sleeve.

6. Turn the impactor up and down to confirm whether the piston slides smoothly in the outer tube.

Seven,            Common troubleshooting methods

Fault 1. Insufficient lubricating oil or did not cause premature wear or damage.

Cause: The lubricating oil cannot reach the impact structure of the impactor.

Remedy: check the lubrication device, adjust the oiler, and increase the amount of oil.

Fault 2. The impactor does not work or does not work properly.

Cause 1. The air path is blocked.

    2. The gap between the piston and the inner and outer cylinders, the piston and the valve seat is too large.

    3. The impactor is blocked by dirt.

    4. Piston or drill tail is broken or other parts are damaged, etc.

Exclusion method:

1. Check the air pressure and check whether the air path is unblocked. Whether the one-way valve is stuck.

2. Disassemble the impactor, check the wear and tear, and replace the worn parts. (In order for the impactor to work well, please use our genuine accessories.)

3. Disassemble the impactor and clean all internal parts in the impactor.

4. Disassemble the impactor and replace damaged parts such as pistons or drill bits. (In order for the impactor to work well, please use our genuine accessories.)

Fault 3. The drill bit and the front joint fall off.

Reason: The impactor was not turned right when it was working.

Troubleshooting method: hook up the falling parts, make sure to turn to the right when drilling or lifting.   

Maintenance and maintenance of down-the-hole drill hammers and drill bits

The impactor and the drill bit are installed at the front end of the drill pipe, using the energy of high-pressure gas to generate continuous impact load to achieve impact and crushing operations on the rock, so the wear is faster. Reasonable and timely maintenance and maintenance can extend the service life of impactors and drill bits and reduce operating costs.
    1, the maintenance and maintenance of the impactor
    In most cases, the performance degradation is caused by the wear of the outer casing or internal parts, and it is necessary to check the wear of each part. If some functions of the impactor cannot be realized, detailed maintenance is required to find the reason.
    When the performance of the impactor drops or breaks down, you can disassemble the impactor to check the usage of various internal parts.
    If the wear of the parts is not obvious, please measure the gap between the following parts: the gap between the drill and the drill guide sleeve, the gap between the piston and the outer tube, the gap between the piston and the cylinder, the piston The gap between the tail hole and the valve rod. Refer to the recommended clearance value provided by the impactor manual to determine which part is more severely worn, and repair the parts. If the parts are damaged or severely worn, replace the parts.
    2. Maintenance and maintenance of drill bits
    The sharper the alloy teeth on the drill, the faster the drilling speed and the higher the work efficiency. At the same time, the pressure of sharp alloy teeth is less than that of blunt alloy teeth. The lower the pressure, the longer the life of the alloy teeth.
    When the alloy teeth are not sharp enough, sharpening is required. In most cases, the alloy teeth wear faster than the bit body, and a part of the bit body can be ground off with an abrasive tool, so that the alloy teeth are exposed, and then the alloy teeth are sharpened.
    3. Lubrication of impactor
    The lubricating oil is sprayed into the high-pressure gas through the oil injector, and the gas is used as the carrier to enter the impactor, so as to realize the lubrication of the internal parts. The amount of lubricating oil can be adjusted by adjusting the opening of the oil injector valve. The amount of lubricating oil should be moderate, large amount will cause waste; small amount will cause poor lubrication effect. During the process of unloading the drill rod, observe the adhesion of the oil on the inner wall of the drill rod.