CN116988748A - Dust-catching device for rock drill and operation method thereof - Google Patents

Abstract

A dust blowing device for a rock drill and an operating method thereof. The dust blowing device includes a dust blowing hood, and also includes a cyclone separator and a water mist nozzle for dust blowing. The cyclone separator is provided with a device connected to its inner cavity. The dust suction port, the gas discharge port and the dust discharge port, the gas discharge port is connected with the air inlet of the fan, the dust suction port is connected with one end of the dust blowing pipe, and the other end of the dust blowing pipe is connected with the dust blowing pipe. The inner cavities of the dust hood are connected. The dust hood, dust pipe, cyclone separator and fan jointly form an air flow channel. The spray outlet or water spray outlet of the water mist nozzle is inserted into the air flow channel. The water mist nozzle is connected to the water tank through the conduit. The water outlets are connected. The conduit is a first conduit, the water mist nozzle is a first water mist nozzle, and the water outlet of the water tank is connected to the first water mist nozzle through the first conduit. The invention has the characteristics of good dust blowing effect.

Description

A dust extraction device for rock drills and its operating method

Technical field

The invention relates to a dust extraction device for a rock drill and an operating method thereof.

Background technique

Rock drills will produce a large amount of dust when working. In order to reduce the dust in the working environment, many manufacturers have made a lot of improvements. For example, Chinese Patent Document No. CN 108868670 A disclosed a self-cleaning dust collector on November 23, 2018. Type electric rock drill, including a main body shell, a guide block and a box shell. A fixed bar is provided inside the box shell, and a guide plate is provided inside the fixed bar. An air valve and an air valve are respectively provided on the left side of the guide plate. There is an air outlet, and the air valve is located on the left side of the air outlet. A filtering device is provided on the right side of the guide plate, and a movable drawer is provided below the guide plate. A filter screen is provided inside the filter device, and a gauze layer is provided on the right side of the filter screen. A conversion joint is provided on the right side of the gauze layer, and a fixed ring is provided on the right side of the conversion joint. There are fan blades and micro motors inside, and the micro motor is located on the right side of the fan blades. When this kind of self-cleaning electric rock drill is actually used, the filter needs to be replaced regularly, which results in relatively high operating costs in the later period, and its dust suction or dust removal effect is not ideal and needs to be improved.

Contents of the invention

The object of the present invention is to provide a dust-expelling device for a rock drill with good dust-expelling effect and an operating method thereof, so as to overcome the deficiencies in the prior art.

A dust blowing device for rock drills designed for this purpose includes a dust blowing hood. Its structural feature is that it also includes a cyclone separator and a water mist nozzle for dust blowing. The cyclone separator is provided with an inner cavity and a The dust suction port, the gas discharge port and the dust discharge port are connected. The gas discharge port is connected with the air inlet of the fan. The dust suction port is connected with one end of the dust blowing pipe, and the other end of the dust blowing pipe is connected. Communicated with the inner cavity of the dust hood, the dust hood, dust pipe, cyclone separator and fan together form an air flow channel. The spray outlet or water spray outlet of the water mist nozzle is inserted into the air flow channel, and the water mist nozzle passes through the conduit. Connected to the water outlet of the water tank.

Further, the conduit is a first conduit, the water mist nozzle is a first water mist nozzle, the water outlet of the water tank is connected to the first water mist nozzle through the first conduit, and the spray outlet or water spray of the first water mist nozzle is The outlet is inserted into the exhaust duct or inlet duct of the fan, and the manual or electric first switch valve is connected in series to the first duct;

And/or, the conduit is a second conduit, the water mist nozzle is a second water mist nozzle, the water outlet of the water tank is connected to the second water mist nozzle through the second conduit, and the spray outlet of the second water mist nozzle or The water spray outlet is inserted into the inner cavity of the cyclone separator, and the manual or electric second switch valve is connected in series in the second conduit;

And/or, the conduit is a third conduit, the water mist nozzle is a third water mist nozzle, the water outlet of the water tank is connected to the third water mist nozzle through the third conduit, and the spray outlet of the third water mist nozzle or The water spray outlet is inserted into the dust extraction pipe, and the manual or electric third switch valve is connected in series in the third conduit;

And/or, it also includes a static pressure box, the conduit is a fourth conduit, the water mist nozzle is a fourth water mist nozzle, one end of the static pressure box is connected with the dust discharge port of the cyclone separator, and the The other end of the static pressure box is provided with a dust discharge outlet. The water outlet of the water tank is connected to the fourth water mist nozzle through the fourth conduit. The spray outlet or water spray outlet of the fourth water mist nozzle is inserted into the inner cavity of the static pressure box. A manual or electric fourth switch valve is connected in series in the fourth conduit; wherein, the static pressure box includes a static pressure chamber located at the upper part and a conical chamber located at the lower part. The conical chamber is in the shape of an inverted cone, and the static pressure box The chamber is connected with the top of the cone-shaped cavity, and the bottom of the cone-shaped cavity is provided with an opening and forms a dust exhaust outlet;

And/or, it also includes a driving mechanism connected to the girder, one end of the air inlet pipe is connected to the exhaust port of the air compressor, and the other end of the air inlet pipe is inserted into the driving mechanism and connected to the inner cavity of the drill pipe, and the conduit is The fifth conduit, the water mist nozzle is the fifth water mist nozzle, the water outlet of the water tank is connected to the fifth water mist nozzle through the fifth conduit, and the spray outlet or water spray outlet of the fifth water mist nozzle is inserted into the inside of the air inlet pipe In the cavity, a manual or electric fifth on-off valve is connected in series to the fifth conduit.

Further, the dust suppression device for rock drills also includes a first one-way valve, which is connected in series in the first conduit and located behind the first switch valve;

And/or, it also includes a second one-way valve, which is connected in series in the second conduit and located behind the second switch valve;

And/or, it also includes a third one-way valve, the third one-way valve is connected in series in the third conduit and is located behind the third switch valve;

And/or, it also includes a fourth one-way valve, which is connected in series in the fourth conduit and located behind the fourth switch valve;

And/or, it also includes a fifth one-way valve, which is connected in series in the fifth conduit and located behind the fifth switch valve.

Further, the cyclone separator is connected to the body, beam or swing arm of the rock drill through the connecting seat; or, the cyclone separator moves together with the body of the rock drill through the casters provided at its bottom.

Furthermore, the water tank is provided with a pneumatic pipe or a water pump for driving the water in the water tank to eject from the water outlet.

Further, the air pressure pipe is connected with the exhaust port of the air compressor.

Further, the water tank is arranged on the body of the rock drill, or the water tank moves together with the body of the rock drill through the casters provided at its bottom.

Further, the dust cover is connected to the beam, swing arm or frame of the rock drill.

An operating method for a dust extraction device for a rock drill, including the following steps:

Step 1: When drilling the first drill pipe, open the first on-off valve, the second on-off valve, the third on-off valve and/or the fourth on-off valve through the central controller of the rock drill. At the same time, open the fifth on-off valve and pass The fifth water mist nozzle sprays or sprays water into the air intake pipe;

Step 2: After drilling the first drill pipe, close the fifth on-off valve through the central controller of the rock drill and continue drilling the remaining drill pipes.

The cyclone separator in the present invention is provided with a dust suction port, a gas discharge port and a dust discharge port connected to its inner cavity. The gas discharge port is connected to the air inlet of the fan, and the dust suction port is connected to the dust extraction pipe. One end of the dust removal pipe is connected to the inner cavity of the dust removal hood, and the other end of the dust removal pipe is connected to the inner cavity of the dust removal hood. The dust removal hood, dust removal pipe, cyclone separator and fan jointly form an air flow channel. The spray outlet of the water mist nozzle or The water spray outlet is inserted into the air flow channel, and the water mist nozzle is connected to the water outlet of the water tank through a duct; the dust hood, dust pipe, cyclone separator and fan together form an air flow channel containing dust. By connecting the spray outlet of the water mist nozzle Or the water spray outlet is inserted into the air flow channel. When the dust blowing device starts to work, the dust-containing gas entering the dust blowing hood moves along the air flow channel under the suction generated by the fan. When the dust-containing gas enters the dust blowing hood, it moves along the air flow channel. When in the dust pipe, cyclone separator and/or fan duct, most of the fine granular dust is gathered into larger particles by the spray outlet of the water mist nozzle or the water mist sprayed from the water outlet, and is finally discharged from the dust discharge port , which reduces the amount of dust discharged from the gas outlet, completely reduces the dust content in the workplace, improves the dust suppression effect, and reduces environmental pollution.

The water mist nozzles in the present invention can be reasonably arranged according to the diameter of the dust hood, the dust pipe, the cyclone separator and/or the fan or the cross-sectional area of the flow channel. For example, multiple arrangements can be spaced along the axial direction, or , multiple settings are spaced along the circumferential direction to improve the dust removal effect.

The present invention does not require replacement of the filter as in the past, so it reduces operating costs in later operations.

To sum up, the present invention has the characteristics of good dust blowing effect.

Description of the drawings

Figure 1 is a schematic structural diagram of an embodiment of the present invention.

Figure 2 is a partially cutaway structural diagram of the cyclone separator and static pressure box after assembly.

Figure 3 is a schematic three-dimensional structural diagram of the cyclone separator and static pressure box assembled.

Figure 4 is a partially cutaway structural schematic diagram of the fifth duct, air intake pipe and driving mechanism after assembly.

In the picture: 1 is the water tank, 2 is the air pressure pipe, 3 is the first switch valve, 4 is the first one-way valve, 5 is the fan, 6 is the drive motor, 7 is the cyclone separator, 8 is the connecting seat, and 9 is the beam. , 10 is the dust cover, 11 is the dust pipe, 12 is the static pressure box, 13 is the driving mechanism, 13.1 is the motor or motor, 13.2 is the air inlet pipe, 14 is the first carriage, 15 is the second carriage, 21 is the first conduit, 23 is the third conduit, 24 is the fourth conduit, 25 is the fifth conduit, 26 is the fifth water mist nozzle, and 26.1 is the spray outlet or water spray outlet of the fifth water mist nozzle.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and examples.

First embodiment

Referring to Figures 1 to 4, a dust removal device for a rock drill includes a dust removal hood 10, a cyclone separator and a water mist nozzle for dust removal. The cyclone separator 7 is provided with an inner cavity and a The dust suction port, the gas discharge port and the dust discharge port are connected. The gas discharge port is connected with the air inlet of the fan 5. The dust suction port is connected with one end of the dust blowing pipe 11. The dust blowing pipe 11 The other end of the dust hood 10 is connected to the inner cavity of the dust hood 10. The dust hood 10, dust pipe 11, cyclone separator and fan 5 together form an air flow channel. The spray outlet or water spray outlet of the water mist nozzle is inserted into the air flow channel. , the water mist nozzle is connected with the water outlet of the water tank 1 through the conduit.

The dust cover 10 is connected to the beam 9, swing arm or frame of the rock drill.

In this embodiment, one end of the swing arm is connected to the vehicle frame, and the other end of the swing arm is connected to the girder 9 .

The dust cover 10 is slidably mounted on the beam 9 through the second carriage 15 .

The water tank 1 is provided with a pneumatic pipe 2 or a water pump for driving the water in the water tank 1 to eject from the water outlet.

In this embodiment, the air pressure pipe 2 may be connected to an air compressor installed on the body of the rock drill, and the air compressor may provide high-pressure gas. The water pump can be directly installed on the water tank, and its power supply is provided by a generator installed on the vehicle body.

The water tank is arranged on the body of the rock drill, or the water tank moves together with the body of the rock drill through casters provided at the bottom.

The cyclone separator 7 is connected to the body of the rock drill, the girder 9 or the swing arm through the connecting seat 8. Alternatively, the cyclone 7 moves together with the body of the rock drill through the casters provided at its bottom.

In order to facilitate the operation, one end of the oil cylinder can also be connected to the connecting seat 8, and the other end of the oil cylinder and the connecting seat 8 are respectively hinged to the body, the girder 9 or the swing arm of the rock drill.

In this embodiment, the conduit is a first conduit, and the water mist nozzle is a first water mist nozzle. The water outlet of the water tank 1 is connected to the first water mist nozzle through the first conduit. The spray outlet or water spray outlet is inserted into the exhaust air duct or the air inlet air duct of the fan 5, and the manual or electric first switch valve 3 is connected in series in the first duct.

The direction of the spray outlet or water spray outlet of the first water mist nozzle is along the gas flow direction.

The dust suppression device for rock drills also includes a first one-way valve 4 , which is connected in series in the first conduit and located behind the first switch valve 3 .

During operation, most of the fine granular dust in the dust-containing gas located in the exhaust air duct or the air inlet air duct of the fan 5 is gathered into larger particles by the water mist sprayed from the spray outlet or water spray outlet of the water mist nozzle. particles, and the buoyancy of the air is not enough to make these larger particles suspended in the air, so these larger particles are detached from the air. Therefore, the dust content in the air in the workplace is reduced, the dust suppression effect is improved, and the impact on the dust is reduced. Environmental pollution.

Second embodiment

In this embodiment, the conduit is a second conduit, and the water mist nozzle is a second water mist nozzle. The water outlet of the water tank 1 is connected to the second water mist nozzle through the second conduit. The spray outlet or water spray outlet is inserted into the inner cavity of the cyclone separator 7, and a manual or electric second switch valve is connected in series in the second conduit.

The dust suppression device for rock drills also includes a second one-way valve, which is connected in series in the second conduit and located behind the second switch valve.

During operation, when gas containing dust enters the cyclone separator, most of the fine granular dust is gathered into larger particles by the spray outlet of the water mist nozzle or the water mist sprayed from the water outlet. Finally, it is discharged from the cyclone separator. The dust discharge port is discharged, thereby reducing the amount of dust discharged from the gas discharge port, completely reducing the dust content in the air in the workplace, improving the dust suppression effect, and reducing environmental pollution.

The remaining undescribed parts can be found in the first embodiment and will not be described again.

Third embodiment

In this embodiment, the conduit is a third conduit, and the water mist nozzle is a third water mist nozzle. The water outlet of the water tank 1 is connected to the third water mist nozzle through the third conduit. The spray outlet or water outlet is inserted into the dust extraction pipe 11, and a manual or electric third switch valve is connected in series in the third conduit.

The dust suppression device for rock drills also includes a third one-way valve, which is connected in series in the third conduit and located behind the third switch valve.

During operation, when gas containing dust enters the dust extraction pipe, most of the fine granular dust is gathered into larger particles by the spray outlet of the water mist nozzle or the water mist sprayed from the water spray outlet. These larger particles are After subsequent treatment by the cyclone separator 7, it is separated from the air flow and finally discharged through the dust discharge port of the cyclone separator 7, thus reducing the amount of dust discharged from the gas discharge port and completely reducing the dust content in the air in the workplace. Improved dust removal effect and reduced environmental pollution.

The remaining undescribed parts can be found in the first embodiment and will not be described again.

Fourth embodiment

In this embodiment, a static pressure box 12 is also included, the conduit is a fourth conduit, the water mist nozzle is a fourth water mist nozzle, and one end of the static pressure box 12 is connected to the dust discharge port of the cyclone separator 7 The other end of the static pressure box 12 is provided with a dust discharge outlet. The water outlet of the water tank 1 is connected with the fourth water mist nozzle through the fourth conduit. The spray outlet or water spray outlet of the fourth water mist nozzle is inserted into the static pressure box 12. In the inner cavity of the pressure box 12, a manual or electric fourth switch valve is connected in series in the fourth conduit; wherein, the static pressure box 12 includes a static pressure chamber located at the upper part and a conical chamber located at the lower part. The cavity is in the shape of an inverted cone, the static pressure chamber is connected with the top of the conical cavity, and the bottom of the conical cavity is open and forms a dust discharge outlet.

During operation, the gas treated by the cyclone separator 7 still contains a small amount of dust. When these gases containing a small amount of dust enter the static pressure chamber above the static pressure box 12 from the dust discharge port of the cyclone separator 7, they interact with the fan 5 Under the action of the suction pipe connected to the air inlet, part of the gas containing a small amount of dust enters the cyclone separator 7 from the dust discharge port of the cyclone separator 7. In this process, the water mist and dust combine to form a larger The particles are finally discharged from the conical cavity outlet at the lower part of the static pressure box 12, and the air flow after dust blowing is discharged to the outside by the fan 5, thereby further reducing the impact on the surrounding environment.

The dust suppression device for rock drills also includes a fourth one-way valve, which is connected in series in the fourth conduit and located behind the fourth switch valve.

The remaining undescribed parts can be found in the first embodiment and will not be described again.

Fifth embodiment

In this embodiment, it includes a driving mechanism 13 connected to the girder 9, one end of the air inlet pipe 13.2 is connected to the exhaust port of the air compressor, and the other end of the air inlet pipe 13.2 is inserted into the driving mechanism 13 and connected to the inner cavity of the drill pipe. The conduit is a fifth conduit 25 and the water mist nozzle is a fifth water mist nozzle 26. The water outlet of the water tank 1 is connected to the fifth water mist nozzle 26 through the fifth conduit 25. The fifth water mist nozzle 26 The spray outlet or water spray outlet is inserted into the inner cavity of the air inlet pipe 13.2, and a manual or electric fifth switching valve is connected in series in the fifth conduit 25.

The driving mechanism 13 is slidably arranged on the girder 9 through the first carriage 14 . The driving mechanism 13 is commonly known as the gun head.

The direction of the spray outlet or water spray outlet 26.1 of the fifth water mist nozzle 26 is along the gas flow direction.

When operating the dust extraction device of the rock drill, the following steps are included:

Step 1: When drilling the first drill pipe, open the first on-off valve, the second on-off valve, the third on-off valve and/or the fourth on-off valve through the central controller of the rock drill. At the same time, open the fifth on-off valve and pass The fifth water mist nozzle 26 sprays or sprays water into the air intake pipe 13.2.

At this time, the spray or water spray located in the air inlet pipe 13.2 can be ejected through the air flow outlet of the impactor that is connected and communicated with the drill pipe. Since the soil or sand around the hole is relatively soft when drilling is just started, it is easy for the soil or sand to fall along the newly drilled hole. The water mist sprayed from the air outlet of the impactor can quickly drill the hole. The hole is shaped, which is conducive to the smooth progress of drilling and improves work efficiency.

Therefore, opening the first on-off valve, the second on-off valve, the third on-off valve and/or the fourth on-off valve is for dust removal, and the fifth on-off valve is for shaping.

Step 2: After drilling the first drill pipe, close the fifth on-off valve through the central controller of the rock drill and continue drilling the remaining drill pipes.

The reason is that the length of the drill pipe is generally between 3m and 8m. After drilling the first drill pipe, as the drilling depth increases, the soil or sand around the hole changes from the initially soft soil or sand to the later compressed soil. Solid soil or hard rock. At this time, the hole that has been drilled has a good shape and no longer needs to be shaped. Therefore, the fifth switch valve can be closed through the central controller of the rock drill and the remaining holes can be drilled. Rod. Of course, when drilling the remaining drill pipes, the first on-off valve, the second on-off valve, the third on-off valve and/or the fourth on-off valve are still opened through the central controller of the rock drill.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", " The directions indicated by "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" etc. or The positional relationship is based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, Therefore, the terms "first" and "second" are not to be construed as limitations of the present invention. The terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features.

The basic principles and main features of the present invention and the advantages of the present invention have been shown and described above. Those skilled in the industry should understand that the present invention is not limited by the above embodiments. The above embodiments and descriptions only illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will also have other aspects. Various changes and modifications are possible, which fall within the scope of the claimed invention. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims (9)

1. A dust blowing device for rock drills, including a dust blowing hood (10), which is characterized in that it also includes a cyclone separator and a water mist nozzle for dust blowing, and the cyclone separator (7) is provided with a dust blowing device. The inner cavity is connected with a dust suction port, a gas discharge port and a dust discharge port. The gas discharge port is connected with the air inlet of the fan (5), and the dust suction port is connected with one end of the dust blowing pipe (11). The other end of the dust extraction pipe (11) is connected with the inner cavity of the dust extraction hood (10). The dust extraction hood (10), dust extraction pipe (11), cyclone separator and fan (5) together form an air flow channel. , the spray outlet or water spray outlet of the water mist nozzle is inserted into the air flow channel, and the water mist nozzle is connected with the water outlet of the water tank (1) through the conduit. 2. The dust ejection device for rock drills according to claim 1, characterized in that the conduit is a first conduit (21), the water mist nozzle is a first water mist nozzle, and the water outlet of the water tank (1) It is connected with the first water mist nozzle through the first duct (21). The spray outlet or water spray outlet of the first water mist nozzle is inserted into the exhaust air duct or the air inlet duct of the fan (5). The manual or electric first The switch valve (3) is connected in series in the first conduit (21); And/or, the conduit is a second conduit, the water mist nozzle is a second water mist nozzle, the water outlet of the water tank (1) is connected to the second water mist nozzle through the second conduit, and the second water mist nozzle The spray outlet or water spray outlet is inserted into the inner cavity of the cyclone separator (7), and the manual or electric second switch valve is connected in series in the second conduit; And/or, the conduit is a third conduit (23), the water mist nozzle is a third water mist nozzle, and the water outlet of the water tank (1) is connected to the third water mist nozzle through the third conduit (23), The spray outlet or water spray outlet of the third water mist nozzle is inserted into the dust removal pipe (11), and the manual or electric third switch valve is connected in series in the third conduit (23); And/or, it also includes a static pressure box (12), the conduit is a fourth conduit (24), the water mist nozzle is a fourth water mist nozzle, and one end of the static pressure box (12) is connected to the cyclone separator. The dust discharge outlet of (7) is connected to each other. The other end of the static pressure box (12) is provided with a dust discharge outlet. The water outlet of the water tank (1) is connected to the fourth water mist nozzle through the fourth conduit (24). The spray outlet or water spray outlet of the fourth water mist nozzle is inserted into the inner cavity of the static pressure box (12), and a manual or electric fourth switch valve is connected in series in the fourth conduit (24); wherein, the static pressure box (12) It includes a static pressure chamber located at the upper part and a tapered chamber located at the lower part. The tapered chamber is in the shape of an inverted cone. The static pressure chamber is connected with the top of the tapered chamber. The bottom of the tapered chamber is provided with an opening and constitutes Dust exhaust outlet; And/or, it also includes a driving mechanism (13) connected to the girder (9), one end of the air inlet pipe (13.2) is connected with the exhaust port of the air compressor, and the other end of the air inlet pipe (13.2) is inserted into the driving mechanism (13.2). 13) Connected to the inner cavity of the drill pipe, the conduit is a fifth conduit (25), the water mist nozzle is a fifth water mist nozzle (26), and the water outlet of the water tank (1) passes through the fifth conduit (25) ) is connected to the fifth water mist nozzle (26). The spray outlet or water spray outlet of the fifth water mist nozzle (26) is inserted into the inner cavity of the air inlet pipe (13.2). The manual or electric fifth switch valve is connected in series. in the fifth duct (25). 3. The dust extraction device for rock drills according to claim 2, characterized by further comprising a first one-way valve (4), said first one-way valve (4) being connected in series to the first conduit (21) in the center and behind the first switching valve (3); And/or, it also includes a second one-way valve, which is connected in series in the second conduit and located behind the second switch valve; And/or, it also includes a third one-way valve, which is connected in series in the third conduit (23) and located behind the third switch valve; And/or, it also includes a fourth one-way valve, which is connected in series in the fourth conduit (24) and located behind the fourth switch valve; And/or, it also includes a fifth one-way valve, which is connected in series in the fifth conduit (25) and located behind the fifth switch valve. 4. The dust ejection device for rock drills according to claim 1, characterized in that the cyclone separator (7) is connected to the body, girder (9) or swing arm of the rock drill through a connecting seat (8); Alternatively, the cyclone separator (7) moves together with the body of the rock drill through the casters provided at its bottom. 5. The dust ejection device for rock drills according to claim 1, characterized in that the water tank (1) is provided with a pneumatic pipe (2) for driving the water in the water tank (1) to eject from the water outlet or water pump. 6. The dust ejection device for rock drills according to claim 1, characterized in that the air pressure pipe (2) is connected with the exhaust port of the air compressor. 7. The dust ejection device for a rock drill according to claim 1, characterized in that the water tank is arranged on the body of the rock drill, or the water tank moves together with the body of the rock drill through casters provided at its bottom. 8. The dust extraction device for a rock drill according to claim 1, characterized in that the dust extraction cover (10) is connected to the beam (9), swing arm or frame of the rock drill. 9. A method of operating a dust extraction device for a rock drill according to claim 1, characterized by comprising the following steps: Step 1: When drilling the first drill pipe, open the first on-off valve, the second on-off valve, the third on-off valve and/or the fourth on-off valve through the central controller of the rock drill. At the same time, open the fifth on-off valve and pass The fifth water mist nozzle (26) sprays or sprays water into the air intake pipe (13.2); Step 2: After drilling the first drill pipe, close the fifth on-off valve through the central controller of the rock drill and continue drilling the remaining drill pipes.