Hydraulic rock drill

Abstract

The hydraulic rock drill comprises a machine body composed of a machine tail part, a cylinder body part, a middle body part and a machine head part which are connected in sequence, and the machine tail part and the cylinder body part jointly form an impact assembly. The middle body part comprises a rotary assembly and a buffer assembly, and the machine head part comprises a washing assembly; the impact assembly and the buffer assembly jointly form a first cavity used for containing an impact piston. The rotary assembly and the flushing assembly jointly form a second cavity used for containing the bit shank, and the first cavity is communicated with the second cavity; the impact assembly introduces hydraulic oil into the first cavity, the impact piston can be pushed by the hydraulic oil to reciprocate along the central axis of the first cavity, and the head of the impact piston can penetrate out of the first cavity, enter the second cavity and impact the tail of the bit shank. The tail part of the bit shank is inserted into the rotary assembly and drives the bit shank to rotate along the central axis through the rotary assembly; a central hole extending towards the head of the bit shank is formed in a front-section rod body of the bit shank, and the flushing assembly injects flushing media into the central hole.

Description

Technical Field

[0001] The utility model relates to a hydraulic rock drill, belonging to the technical field of rock drills. Background Art

[0002] A rock drill works according to the impact crushing principle. During operation, the piston makes high-frequency reciprocating motions and continuously impacts the shank end. Under the action of the impact force, the head of the shank end crushes the rock and drills into a certain depth, forming a dent. After the piston retracts, the shank end rotates by a certain angle. When the piston moves forward and impacts the shank end again, a new dent is formed. The fan-shaped rock block between the two dents is sheared by the horizontal component force generated on the shank end. The piston continuously impacts the shank end, and compressed air or pressure water is continuously input from the central hole of the shank end to discharge the rock slag out of the hole, thus forming a circular drill hole with a certain depth.

[0003] However, most of the existing hydraulic rock drills use long screws to connect various components in series. During the working process, the deformation of the long screws caused by the vibration of the machine body will lead to problems such as loose connection and poor stability. At the same time, a double-stage buffer design is mostly adopted, so the number of parts required is large and the processing difficulty is high. At the same time, it is also easy to cause wiring errors on site (the number of access ports increases). Content of the Utility Model

[0004] The purpose of the utility model is to provide a hydraulic rock drill, which adopts a segmented connection method to improve the overall stability of the machine body and is convenient for subsequent maintenance and replacement of components; at the same time, a single-stage buffer design is adopted to reduce the number of parts and the processing difficulty, and the problem of wiring errors can be avoided.

[0005] In order to achieve the above purpose, the technical solution adopted by the utility model is as follows:

[0006] A hydraulic rock drill includes a machine body composed of a machine tail part, a cylinder body part, an intermediate body part and a machine head part connected in segments. Among them, the machine tail part and the cylinder body part jointly form an impact assembly; the intermediate body part includes a slewing assembly and a buffer assembly, and the machine head part includes a flushing assembly;

[0007] The impact assembly and the buffer assembly jointly form a first chamber for accommodating an impact piston; the slewing assembly and the flushing assembly jointly form a second chamber for accommodating the shank end, and the first chamber is communicated with the second chamber;

[0008] The impact assembly injects hydraulic oil into the first chamber. The impact piston can reciprocate along the central axis of the first chamber under the extrusion of the hydraulic oil, and the head of the impact piston can penetrate the first chamber and enter the second chamber to impact the tail of the shank end;

[0009] The tail of the shank end is inserted into the slewing assembly and the slewing assembly drives the shank end to rotate forward or backward along the central axis;

[0010] The buffer assembly includes a rear stop sleeve for the tool shank and a buffer piston; the rear stop sleeve for the tool shank abuts against the tail of the tool shank to limit the axial displacement of the tool shank backward; an annular buffer cavity is formed radially in the second chamber of the intermediate body portion, and the buffer piston is installed at the front end of the second chamber and closes the buffer cavity; hydraulic oil is injected into the buffer cavity and can push the buffer piston to axially displace forward to abut against the rear stop sleeve for the tool shank; when the tool shank rebounds, it impacts the rear stop sleeve for the tool shank and acts on the buffer piston, and the buffer piston is impacted by the rear stop sleeve for the tool shank and axially displaces backward and extrudes the hydraulic oil out of the buffer cavity;

[0011] A central hole extending towards the head of the tool shank is formed on the front section of the tool shank, and the flushing assembly injects flushing medium into the central hole.

[0012] Preferably, the cylinder body portion includes a commutation mechanism, and the commutation mechanism includes a valve sleeve, a valve body, a cylinder sleeve and an impact piston;

[0013] The head of the valve sleeve abuts against the tail of the cylinder sleeve, the valve body is installed in the inner cavity of the valve sleeve, and the head of the cylinder sleeve extends into the tail cavity of the intermediate body portion and abuts against the intermediate body portion; the piston is installed in the inner cavity of the cylinder sleeve, and the inner cavity of the valve sleeve is communicated with the inner cavity of the cylinder sleeve;

[0014] The hydraulic oil pushes the valve body and the impact piston to reciprocate. When the valve body axially displaces forward by a preset distance, the hydraulic oil pushes the impact piston forward; when the impact piston advances by a preset distance, the hydraulic oil pushes the valve body to axially displace backward; when the valve body axially displaces backward by a preset distance, the hydraulic oil pushes the impact piston to retreat; when the impact piston retreats by a preset distance, the hydraulic oil pushes the valve body to axially displace leftward, and so on in a cycle.

[0015] Preferably, an annular rear-end high-pressure oil cavity and an annular rear-end total oil return cavity are sequentially formed radially from the rear to the front between the first chamber and the valve sleeve;

[0016] A rear-end oil return cavity is formed between the abutting portion of the inner cavity of the valve sleeve and the inner cavity of the cylinder sleeve and the valve body;

[0017] An annular intermediate oil return cavity, a front-end oil return cavity and a front-end high-pressure oil cavity are sequentially formed radially from the rear to the front in the cylinder sleeve and are isolated by the impact piston;

[0018] The valve body closes the communication channel between the rear-end high-pressure oil cavity and the inner cavity of the valve sleeve. After the hydraulic oil is injected into the rear-end high-pressure oil cavity, it pushes the valve body to axially displace forward to connect the rear-end high-pressure oil cavity with the inner cavity of the valve sleeve, and the hydraulic oil enters the inner cavity of the valve sleeve and pushes the impact piston to axially displace forward;

[0019] When the impact piston advances by a preset distance, the front-end high-pressure oil cavity is communicated with the front-end return cavity, the hydraulic oil pushes the valve body to axially displace backward to close the communication channel between the rear-end high-pressure oil cavity and the inner cavity of the valve sleeve, and the impact piston completes the impact under the action of the hydraulic oil and retreats backward;

[0020] When the impact piston retracts backward by a preset distance, the front-end return oil cavity communicates with the middle oil return cavity, the rear-end oil return cavity, and the rear-end total oil return cavity; the high-pressure oil injected into the rear-end high-pressure oil cavity pushes the valve body to axially displace forward to connect the rear-end high-pressure oil cavity with the inner cavity of the valve sleeve, and the hydraulic oil enters the inner cavity of the valve sleeve and pushes the impact piston to axially displace forward, and so on in a cycle.

[0021] Preferably, a plurality of rear-pushing channels that are axially distributed and circumferentially arranged along the inner edge of the head of the valve sleeve and communicate with the communication channel between the rear-end high-pressure oil cavity and the inner cavity of the valve sleeve and the rear-end oil return cavity are provided;

[0022] A plurality of front-pushing channels that are axially distributed and circumferentially arranged along the inner edge of the tail of the cylinder sleeve and communicate with the rear-end oil return cavity and the front-end oil return cavity are provided;

[0023] Rear push rods and front push rods for pushing the valve body to axially displace are respectively and slidably arranged in the rear push channels and the front push channels, and the diameter of the front push rod is larger than that of the rear push rod.

[0024] Preferably, the buffer assembly further includes a plurality of accumulators installed outside the cylinder body part;

[0025] The impact assembly and the buffer assembly together form a plurality of oil inlet channels for supplying hydraulic oil to the rear-end high-pressure oil cavity, the front-end high-pressure oil cavity, and the buffer cavity;

[0026] The impact assembly forms an oil outlet channel for discharging the hydraulic oil in the rear-end total oil return cavity;

[0027] And the rear-end high-pressure oil cavity, the front-end high-pressure oil cavity, and the buffer cavity are all connected to the liquid phase side of the accumulator through the oil inlet channels.

[0028] Preferably, the commutation mechanism further includes a sealing component arranged in the inner cavity of the tail of the valve sleeve and the inner cavity of the head of the cylinder body for preventing hydraulic oil leakage; leakage oil cavities are respectively formed between the sealing component and the corresponding inner cavity of the valve sleeve and the inner cavity of the cylinder body;

[0029] The impact assembly forms a leakage oil channel, and the leakage oil cavity communicates with the leakage oil channel for discharging the leakage oil.

[0030] Preferably, the slewing assembly includes a cycloid motor, a pinion gear, a large gear, and a stop ring; the slewing assembly further forms a third chamber for accommodating the pinion gear;

[0031] The large gear is installed in the second chamber and isolates the third chamber from the second chamber. The tail of the large gear abuts against the head of the buffer piston, and the rear retaining sleeve of the drill steel is slidably arranged in the inner cavity of the tail of the large gear; the stop ring is embedded in the tail of the machine head and is coaxially arranged with the drill steel, and the head of the large gear abuts against the tail of the stop ring;

[0032] The drill steel shank passes through the stop ring, and the end of the drill steel shank is located in the inner cavity of the head of the large gear and will not separate from the large gear after being impacted;

[0033] There is no rotational fit between the drill steel shank and the large gear. The large gear meshes with the small gear, and the cycloidal motor is used to drive the small gear to rotate forward or backward, thereby driving the large gear and the drill steel shank to rotate synchronously;

[0034] A lubricating chamber is formed between the large gear and the third chamber, and the lubricating chamber is communicated with the leakage oil passage; the hydraulic oil leaked from the cycloidal motor for driving is led into the lubricating chamber to lubricate the small gear and the large gear and is discharged through the leakage oil passage.

[0035] Preferably, an annular flushing chamber is formed radially in the second chamber located in the machine head;

[0036] The flushing assembly includes a flushing head, and the flushing head is installed in the machine head and closes the flushing chamber;

[0037] The flushing assembly further includes a drill steel shank copper sleeve and a machine head copper sleeve which are arranged at the rear side of the tail of the flushing head and the front side of the head and are used to prevent the radial deviation of the drill steel shank; the flushing head, the drill steel shank copper sleeve and the machine head copper sleeve are all sleeved outside the drill steel shank;

[0038] The machine head is formed with a water inlet passage communicated with the flushing chamber, and the flushing head is formed with a passage communicated with the central hole of the drill steel shank, and a flushing medium is injected into the central hole through the water inlet passage;

[0039] Two U-shaped seals are arranged in the flushing head to prevent the flushing medium entering the cavity between the drill steel shank and the flushing head from leaking;

[0040] The head of the drill steel shank copper sleeve abuts against the U-shaped seal in the cavity at the tail of the flushing head, and a leakage chamber for accommodating the flushing medium leaked from the cavity between the drill steel shank and the flushing head is formed between the drill steel shank copper sleeve and the drill steel shank;

[0041] A return liquid chamber is formed between the drill steel shank copper sleeve and the second chamber located in the machine head. The leakage chamber is communicated with the return liquid chamber, and a liquid discharge passage for discharging the flushing medium in the return liquid chamber is arranged on the machine head;

[0042] The machine head is formed with two lubricating channels, and lubricating oil is injected into the two lubricating channels to lubricate the gaps between the machine head and the machine head copper sleeve, the flushing head and the drill steel shank respectively, and the U-shaped seal in the leakage chamber.

[0043] Preferably, the intermediate body part includes an intermediate body and a gearbox cover;

[0044] The machine tail, the cylinder block part, the intermediate body, the gearbox cover and the machine head abut against each other in sequence, and dust-proof rings are arranged at the abutting surfaces of the machine tail, the cylinder block part, the intermediate body, the gearbox cover and the machine head, at the abutting surface between the cylinder block part and the accumulator, and at the abutting surface between the cycloidal motor and the intermediate body;

[0045] The tail part of the machine body, the cylinder block part, the intermediate body, the gearbox cover, the cycloid motor and the head part of the machine body jointly form an air passage, and an annular air passage chamber connected to the air passage is formed in the second chamber where the large gear abuts against the buffer piston; the impact piston also has a central passage;

[0046] Purge gas is introduced into the air passage, and the purge gas is blown out through the contact surfaces of the tail part of the machine body, the cylinder block part, the intermediate body, the gearbox cover, the head part of the machine body, the contact surface between the cylinder block part and the accumulator, the contact surface between the cycloid motor and the intermediate body, and the gap between the head of the drill rod tail and the copper bushing of the head of the machine for air purging; and enters the gaps between the impact piston and the buffer piston and the rear retaining sleeve of the drill rod tail, the cavity formed between the impact piston and the tail part of the machine body, and the gap between the drill rod tail and the large gear through the air passage for air cooling.

[0047] Preferably, the interfaces of the oil inlet passage, the oil outlet passage, the leakage oil passage and the air passage are all opened at the tail of the tail part of the machine body;

[0048] Both the head and the tail of the large gear are fitted to the inner cavity of the intermediate body, and Gland rings are arranged at the fitting surfaces to isolate the third chamber from the second chamber through the Gland rings;

[0049] A plurality of guide rings are also arranged at the fitting surfaces of the large gear and the inner cavity of the intermediate body outside the two Gland rings.

[0050] The beneficial effects of the present utility model are as follows:

[0051] 1. The various parts of the machine body are connected in sections, and the assembly between parts is more firm, which can improve the overall stability, and can solve the problems of loose connection and poor stability caused by the deformation of the long screw due to the vibration of the machine body during the working process of the hydraulic rock drill, facilitating the subsequent maintenance and replacement of components; at the same time, it can reduce the installation gap, and it is also convenient to disassemble the corresponding connecting parts when only a single part is damaged (no need for overall disassembly);

[0052] 2. The buffer assembly adopts a single-stage buffer design, which solves the problem that the existing double-stage buffer assembly needs to separately open a buffer oil port; at the same time, the oil inlet and outlet of the buffer assembly are both realized through the oil inlet passage, and there is no need to separately open a passage to realize the oil inlet and outlet at the buffer assembly, reducing the processing difficulty;

[0053] 3. With the structural design of the impact assembly, the stroke of the impact piston is limited, making it have the characteristics of small impact work and high frequency, which can reduce the damage to the impact piston and the drill rod tail and extend their service life;

[0054] 4. The lubrication between the large gear and the small gear is achieved by the leakage oil of the cycloid motor, eliminating the need for the operator to inject additional grease before the rock drill works in each shift. This avoids the cumbersome process of injecting grease at the large and small gears in the existing method for each shift.

[0055] 5. The head of the cylinder liner extends into the tail cavity of the intermediate body part and abuts against the intermediate body part. After the bolts become loose, this connection relationship between the cylinder liner and the intermediate body can effectively protect the impact piston and prevent it from being easily damaged.

[0056] 6. The flushing assembly can effectively flush the drill tail and adopts a design without a flushing joint, avoiding the problem that the bolts at the connection between the existing flushing joint and the machine head are prone to falling off, resulting in flushing failure.

[0057] 7. A dust-proof ring is set at the abutting surface and air blowing treatment is adopted. At the same time, the gap between the head of the drill tail and the machine head can also be blown with air, which can reduce the risk of part damage and extend the service life. Further, the purging air can also enter the gaps between the buffer piston and the rear retaining sleeve of the drill tail, the buffer piston, the large gear, and the gap between the drill tail and the large gear to cool the components and reduce the working temperature.

[0058] 8. The number of parts in this hydraulic rock drill is reduced to about 90. Most of the components can be purchased as products of the same specification on the market, making replacement more convenient. Moreover, the optimized parts are also easy to be processed.

[0059] 9. The interfaces of the oil inlet channel, oil outlet channel, leakage oil channel, and air passage are concentratedly opened at the tail of the machine tail. Therefore, it can be applied regardless of which side of the jumbo the oil supply system and the tubing are arranged. The installation angle of the machine head can also be adjusted according to the placement position of the flushing system to make it more convenient to connect the flushing medium to the water inlet channel, improving the applicability. And the overall structure of the machine body adopts a nearly symmetrical design, which is conducive to being assembled onto the rock drilling jumbo.

[0060] 10. A Gleason ring is set at the mating surface between the large gear and the inner cavity of the intermediate body. The third chamber is isolated from the second chamber through the Gleason ring. This unique sealing design replaces the traditional skeleton oil seal and can withstand greater oil pressure. At the same time, multiple guide rings set at the mating surface can effectively support the large gear, enabling it to maintain axial stability during operation and extending its service life.

[0061] 11. A drill tail copper sleeve and a machine head copper sleeve are set inside the machine head. The drill tail copper sleeve and the machine head copper sleeve replace the existing single support to play a guiding and supporting role, preventing the drill tail from having radial offset, improving the stability of the drill tail during impact and rotation, and ensuring the service life of the drill tail at the same time.

[0062] 12. The seal (U-shaped seal) used to prevent the leakage of the flushing medium in the existing machine head is extremely inconvenient to disassemble due to the body structure and the component installation structure, making it inconvenient to replace the seal when it is worn and loses its sealing effect. Therefore, in this application, the machine head and the gearbox cover are detachably connected, so that the drill steel bushing and the flushing head can be easily taken out, and then the U-shaped seal can be taken out from the drill steel bushing and the flushing head, and then the U-shaped seal can be replaced. The operation is simple and convenient, reducing manpower and financial resources. Brief Description of the Drawings

[0063] Figure 1 is a three-dimensional schematic diagram of the hydraulic rock drill;

[0064] Figure 2 is a cross-sectional view of one perspective of the hydraulic rock drill;

[0065] Figure 3 is a cross-sectional view of another perspective of the hydraulic rock drill;

[0066] Figure 4 is a half-sectional view of the hydraulic rock drill;

[0067] Figure 5 is a schematic diagram of the structure at the front and rear push rods;

[0068] Figure 6 is a schematic diagram of the structure at one place of the hole passage;

[0069] Figure 7 is a schematic diagram of the structures at the second and third hole passages;

[0070] Figure 8 is a schematic diagram of the structure of the cylinder liner and the impact piston;

[0071] Figure 9 is a schematic diagram of the structure at the oil inlet passage and the oil outlet passage;

[0072] Figure 10 is a schematic diagram of the structure of the triangular sleeve;

[0073] Figure 11 is a cross-sectional view of the fastener connection;

[0074] Figure 12 is a schematic diagram of the air passage for supplying air to the air chamber.

[0075] The meanings of the main reference numerals in the drawings are as follows:

[0076] 1. Tail part of the machine, 2. Cylinder block part, 3. Intermediate body part, 4. Head part of the machine, 5. Rear cover, 6. Cylinder block, 7. Intermediate body, 8. Gearbox cover, 9. Head of the machine, 10. Fastener, 11. Dust seal, 12. Impact piston, 13. Tool shank, 14. Valve sleeve, 15. Valve body, 16. Cylinder liner, 17. Rear seal sleeve, 18. Rear copper sleeve, 19. Piston front guide sleeve, 20. Front seal guide sleeve, 21. Sealing ring, 22. Strseal, 23. High-pressure oil chamber at the rear end, 24. Total return oil chamber at the rear end, 25. Impact oil inlet interface, 26. Impact oil return interface, 27. Connecting channel, 28. Rear push channel, 29. Rear end return oil chamber, 30. Intermediate return oil chamber, 32. Front end return oil chamber, 33. High-pressure oil chamber at the front end, 34. Channel 1, 35. Channel 2, 36. Channel 3, 37. Ring groove, 38. Front push channel, 39. Rear push rod, 40. Front push rod, 41. Rear stage, 42. Front stage, 43. Stress surface A, 44. Stress surface C, 45. Section B, 46. Stress surface B, 47. Inner stage D, 48. Inner stage E, 49. Leakage oil chamber, 50. Leakage oil return joint, 51. Leakage oil channel, 52. Buffer chamber, 53. Rear retaining sleeve for tool shank, 54. Buffer piston, 55. Accumulator, 56. Oil inlet channel, 57. Oil outlet channel, 58. Gearbox, 59. Stop ring, 60. Pinion, 61. Gear, 62. Needle bearing, 63. Taper bearing, 64. Inner copper sleeve, 65. Triangular sleeve, 66. Flushing head, 67. Copper sleeve for tool shank, 68. Copper sleeve for head of the machine, 69. U-seal, 70. Central hole, 71. Flushing chamber, 72. Water passage hole, 73. Flushing medium interface, 74. Protective cover; 75. Cycloid motor, 76. Gear pad, 77. Lubrication chamber, 78. Flushing water leakage chamber, 79. Return water chamber, 80. Drain port, 81. Drainage channel, 82. Oil filling port, 83. Oil filling plug, 84. Purge gas chamber, 85. Purge gas hole, 87. Gas passage, 88. Gas chamber, 89. Guide ring, 90. Oil seal, 91. Gleitring. Detailed implementation mode

[0077] The following specifically introduces the present utility model in conjunction with the accompanying drawings and embodiments.

[0078] This embodiment provides a hydraulic rock drill, see Figures 1-12As shown in the figure, it includes a body composed of a machine tail part 1, a cylinder block part 2, an intermediate body part 3, and a machine head part 4 connected in sections. Among them, the machine tail part 1 includes a rear cover 5, the cylinder block part 2 includes a cylinder block 6, the intermediate body part includes an intermediate body 7 and a gearbox cover 8, the machine head part 4 includes a machine head 9, and the machine tail is fixed to the cylinder block 6 through a plurality of fasteners 10, the cylinder block 6 is fixed to the intermediate body 7 through a plurality of fasteners 10, and the intermediate body 7, the gearbox cover 8, and the machine head 9 are sequentially positioned through a plurality of positioning pins inside and then fixed through a plurality of fasteners 10, and the tail of the gearbox cover 8 is embedded in the head of the intermediate body 7, and the tail of the machine head 9 is embedded in the head of the gearbox cover 8. At the same time, dust-proof rings 11 are provided at the abutting surfaces between the rear cover 5 and the cylinder block 6, between the cylinder block 6 and the intermediate body 7, between the intermediate body 7 and the gearbox cover 8, and between the gearbox cover 8 and the machine head 9.

[0079] The body of the hydraulic rock drill is divided into multiple sections according to its structure and is connected into an integral structure through independent fasteners 10, so as to replace the method of using long screws to fix multiple sections of the existing rock drill into one body. By optimizing the structural stress, the overall stability is improved, effectively solving the problems of loose connection and poor stability caused by the deformation of the long screws due to the vibration of the body during the working process of the hydraulic rock drill, and at the same time facilitating the subsequent maintenance and replacement of components.

[0080] The machine tail part 1 and the cylinder block part 2 jointly form an impact assembly; the intermediate body part 3 includes a slewing assembly and a buffer assembly, and the machine head part 4 includes a flushing assembly. The impact assembly and the buffer assembly jointly form a first chamber for accommodating an impact piston 12 (having a central passage); the slewing assembly and the flushing assembly jointly form a second chamber for accommodating a shank end 13, and the first chamber is communicated with the second chamber. Specifically, after the machine tail and the cylinder block 6, the cylinder block 6 and the intermediate body 7, and the intermediate body 7, the gearbox cover 8, and the machine head 9 are fixed through the fasteners 10, a connected first chamber and second chamber are formed.

[0081] Among them, the impact assembly further includes a valve sleeve 14, a valve body 15, a cylinder sleeve 16, and an impact piston 12. The valve sleeve 14 is arranged in the inner cavity at the tail of the cylinder block 6 and abuts against the rear cover 5; the cylinder sleeve 16 is arranged in the inner cavity at the head of the cylinder block 6, the tail of the cylinder sleeve 16 abuts against the head of the valve sleeve 14, the head of the cylinder sleeve 16 is inserted into the inner cavity at the tail of the intermediate body 7, and the valve sleeve 14 and the cylinder sleeve 16 are also positioned through a positioning pin to prevent relative rotation. A rear seal sleeve 17 and a rear copper sleeve 18 are sequentially clamped in the inner cavity at the tail of the valve sleeve 14 from back to front, the valve body 15 is arranged in the inner cavity at the head of the valve sleeve 14, a piston front guide sleeve 19 and a front seal guide sleeve 20 are sequentially clamped in the inner cavity at the head of the valve sleeve 14 from back to front, and the impact piston 12 sequentially passes through the rear seal sleeve 17, the rear copper sleeve 18, the valve body 15, the piston front guide sleeve 19, and the front seal guide sleeve 20 and extends into the second chamber.

[0082] Between the contact surfaces among the valve sleeve 14 and the rear cover 5, the cylinder block 6, the rear seal sleeve 17, and the rear copper sleeve 18, and between the contact surfaces among the cylinder sleeve 16 and the cylinder block 6, the intermediate body 7, the piston front guide sleeve 19, and the front seal guide sleeve 20, they are all sealed by the sealing ring 21, and the sealing ring 21 does not block the flow channels of the hydraulic oil or the lubricating gas. At the same time, in the groove bodies inside the rear seal sleeve 17 and the front seal guide sleeve 20, there are installed the Struthers seals 22 for ensuring the sealing effect with the impact piston 12 and preventing the leakage of the hydraulic oil. That is, the rear seal sleeve 17 and the rear copper sleeve 18, the piston front guide sleeve 19 and the front seal guide sleeve 20, as well as the corresponding sealing ring 21 and Struthers seal 22 form a sealing assembly for preventing the leakage of the hydraulic oil.

[0083] Between the valve sleeve 14 and the cylinder block 6, from the rear to the front, there are successively formed a rear-end high-pressure oil cavity 23 and a rear-end total oil return cavity 24. On the rear cover 5, there are provided two impact oil inlet interfaces 25 (P) communicated with the rear-end high-pressure oil cavity 23 and two impact oil return interfaces 26 (T) communicated with the rear-end total oil return cavity 24. Inside the head of the valve sleeve 14, there are multiple communication channels 27 for communicating the rear-end high-pressure oil cavity 23 with the inner cavity of the head of the valve sleeve 14, and along the axial direction around the head of the valve sleeve 14, there are provided multiple rear push channels 28, and the rear push channels 28 are communicated with several of the communication channels 27.

[0084] Between the abutting part of the inner cavity of the valve sleeve 14 and the inner cavity of the cylinder sleeve 16 and the valve body 15, there is formed a rear-end oil return cavity 29; inside the cylinder sleeve 16, from the rear to the front along the radial direction, there are successively formed an annular intermediate oil return cavity 30, a front-end oil return cavity 32, and a front-end high-pressure oil cavity 33, which are isolated by the impact piston 12. The intermediate oil return cavity 30 is communicated with the rear-end oil return cavity 29 through the first hole 34 inside the cylinder sleeve 16, and is communicated with the rear-end total oil return cavity 24 through the second hole 35 communicated with the first hole 34 inside the valve sleeve 14 and the third hole 36 communicated with the second hole 35. Inside the cylinder block 6, there is also formed an annular groove 37 communicated with the front-end high-pressure oil cavity 33, and the annular groove 37 is communicated with the rear-end high-pressure oil cavity 23 and the impact oil inlet interface 25 (P); inside the tail of the cylinder block 6, there are multiple front push channels 38 respectively corresponding to the rear push channels 28 and having two ends respectively communicated with the rear-end oil return cavity 29 and the intermediate oil return cavity 30.

[0085] Inside each backward push channel 28 and each forward push channel 38, a backward push rod 39 and a forward push rod 40 are respectively embedded. The diameter of the forward push rod 40 is greater than that of the backward push rod 39, and the backward push rod 39 and the forward push rod 40 can move freely (with clearance fit) in the corresponding backward push channel 28 and forward push channel 38; the valve body 15 can move freely (with clearance fit) in the head inner cavity of the valve sleeve 14. In the initial state, the tail of the valve body 15 closes the communication channel 27, and there is a clearance between the head of the valve body 15 and the rear end of the cylinder sleeve 16 for communicating the inner cavity of the valve body 15 with the rear end oil return cavity 29; a convex portion is formed on the outer periphery of the front end of the valve body 15. The backward push rod 39 abuts against the rear end face of the convex portion, and the forward push rod 40 abuts against the front end face of the convex portion. Under the action of hydraulic oil, the valve body 15 can axially displace relative to the impact piston 12 within the space formed by the front end inner cavity of the valve sleeve 14 and the rear end inner cavity of the cylinder sleeve 16.

[0086] The impact piston 12 has a backstage stage 41 and a front stage 42. A force-receiving surface A43 is formed at the rear end of the backstage stage 41 of the impact piston 12, and a force-receiving surface C44 is formed at the front end. A cross-section B45 is formed at the rear end of the front stage 42 of the impact piston 12, and a force-receiving surface B46 is formed at the front end. The force-receiving area of the force-receiving surface A43 is greater than the force-receiving areas of the force-receiving surfaces C44 and B46; and the backstage stage 41 of the impact piston 12 can axially displace in the head inner cavity of the valve sleeve 14 and the tail inner cavity of the cylinder sleeve 16. The cylinder sleeve 16 has an inner stage D47 for separating the front end oil return cavity 32 from the front end high-pressure oil cavity 33 and an inner stage E48 for separating the front end high-pressure oil cavity 33 from the head inner cavity of the cylinder sleeve 16. The front stage 42 of the piston can axially displace in the inner stage D47, the front end high-pressure oil cavity 33, and the inner stage E48 of the cylinder sleeve 16.

[0087] The rear seal sleeve 17 and the rear copper sleeve 18 jointly form a rear seal assembly, and the piston front guide sleeve 19 and the front seal guide sleeve 20 jointly form a front seal assembly. Leakage oil cavities 49 are respectively formed between the rear seal assembly, the front seal assembly and the corresponding inner cavity of the valve sleeve 14 and the inner cavity of the cylinder block 6; a leakage oil return joint 50 (Da) is provided on the rear cover 5, and leakage oil channels 51 are formed on the cylinder block 6 and the intermediate body 7. The leakage oil cavity 49 is connected to the leakage oil channel 51 and communicated with the leakage oil return joint 50 for discharging the hydraulic oil in the leakage oil cavity 49.

[0088] An annular buffer cavity 52 is formed radially in the head inner cavity of intermediate 7. The buffer assembly includes a tool shank rear retaining sleeve 53 and a buffer piston 54. The impact piston 12 passes through the buffer piston 54 and the tool shank rear retaining sleeve 53. The buffer piston 54 is embedded in the head inner cavity of intermediate 7 and closes the buffer cavity 52. The tool shank rear retaining sleeve 53 is arranged between the buffer piston 54 and the tool shank 13 and abuts against each other. The buffer cavity 52 is filled with hydraulic oil that can push the buffer piston 54 to axially displace forward to abut against the tool shank rear retaining sleeve 53. When the tool shank 13 rebounds, it impacts the tool shank rear retaining sleeve 53 and acts on the buffer piston 54. The buffer piston 54 is impacted by the tool shank rear retaining sleeve 53 and axially displaces backward to squeeze the hydraulic oil out of the buffer cavity 52.

[0089] Two accumulators 55 are symmetrically installed outside the cylinder block part 2. A plurality of oil inlet channels 56 for supplying hydraulic oil to the rear high-pressure oil cavity 23, the front high-pressure oil cavity 33, and the buffer cavity 52 are jointly formed in the cylinder block 6 and the intermediate 7. The oil inlet channel 56 is communicated with the impact oil inlet interface 25 (P). An oil outlet channel 57 for discharging the hydraulic oil in the rear total oil return cavity 24 is also formed in the cylinder block 6. The oil outlet channel 57 is communicated with the impact oil return interface 26 (T). Moreover, the rear high-pressure oil cavity 23, the front high-pressure oil cavity 33, and the buffer cavity 52 are all connected to the liquid phase side of the accumulator 55 through the oil inlet channel 56. Further, a nitrogen filling head connected to the gas phase side is installed on the accumulator 55 to facilitate filling nitrogen into the gas phase side of the accumulator 55.

[0090] The slewing assembly includes a transmission mechanism and a tool shank 13. The tool shank 13 is horizontally and rotatably arranged in the transmission mechanism located in the intermediate 7 and in the machine head 9 and extends outside the head of the machine head 9. The tail of the tool shank 13 abuts against the tool shank rear retaining sleeve 53, and there is a certain distance to-be-hit interval left between the head of the tool shank 13 and the impact piston 12. When the impact piston 12 is axially displaced forward under the action of hydraulic oil, it acts on the tool shank 13 to cause it to axially displace.

[0091] The transmission mechanism includes a cycloid motor 75 installed on the gearbox 58 on the intermediate 7, which is used to drive the transmission components to act to drive the tool shank 13 to rotate, and a stop ring 59 located in the tail inner cavity of the machine head 9 for restricting the axial displacement distance of the tool shank 13.

[0092] The transmission assembly includes a pinion gear 60 and a large gear 61. The pinion gear 60 is arranged in the cavity (the third chamber) above the gearbox 58, and is in transmission connection with the output shaft of the cycloid motor 75 (meshing teeth are formed in the output shaft of the cycloid motor 75 and the inner cavity of the end of the pinion gear), and is rotationally connected to the gearbox 58 through needle roller bearings 62 arranged on the outer sides of both ends. At the same time, a gear pad 76 is arranged in the cavity on the gearbox 58, with one end inserted into the pinion gear 60 to prevent the pinion gear 60 from shifting, and the other end of the gear pad 76 abuts against the inner wall of the cavity above the gearbox 58; the large gear 61 is arranged in the cavity below the gearbox 58 and meshes with the pinion gear 60, and is rotationally connected to the gearbox 58 through two tapered bearings 63 arranged on the outer peripheries of both ends and the axial displacement of the large gear 61 is restricted. The head of the large gear 61 extends into the inner cavity of the gearbox cover 8, and the tail abuts against the buffer piston 54, and the rear retaining sleeve 53 of the drill rod tail is arranged in the inner cavity of the tail of the large gear 61. At the same time, two stepped stages with an increasing inner diameter are formed in the inner cavity of the head of the large gear 61 from back to front. An inner copper sleeve 64 is embedded in the stepped stage at the rear end, and a triangular prism sleeve 65 is embedded in the stepped stage at the front end. There is no rotational fit between the triangular prism sleeve 65 and the large gear 61 (that is, relative rotation cannot occur between the triangular prism sleeve 65 and the large gear 61), and the tail of the drill rod tail 13 is inserted into the inner cavity of the triangular prism sleeve 65 without rotational fit either (that is, relative rotation cannot occur between the triangular prism sleeve 65 and the drill rod tail 13) and can axially displace relative to the triangular prism sleeve 65. At the same time, a limiting portion is formed at the tail of the drill rod tail 13 to limit the drill rod tail 13 from being disengaged from the triangular prism sleeve 65 after being impacted.

[0093] An oil inlet interface for supplying hydraulic oil to the cycloid motor 75 and an oil drain interface for discharging the hydraulic oil in the cycloid motor 75 are arranged outside the cylinder block 2 (the interface A / B is selectively used as the oil inlet interface or the oil drain interface, and the rotation direction of the cycloid motor 75 is changed by changing the oil inlet and drain interfaces. This is the prior art, and the structure of the cycloid motor 75 and the hydraulic drive commutation principle will not be described in detail here). Both the oil inlet interface and the oil drain interface are connected to the channels on the intermediate body and the oil cavities in the cycloid motor 75 through pipelines for the inlet and outlet of hydraulic oil. The cycloid motor 75 is actuated to drive the pinion gear 60 to act and then drive the large gear 61 to rotate. Since the tail of the drill rod tail 13 is inserted into the inner cavity of the triangular prism sleeve 65, and there is no rotational fit between the triangular prism sleeve 65 and the large gear 61, and the tail of the drill rod tail 13 is inserted into the inner cavity of the triangular prism sleeve 65 without rotational fit and can axially displace relative to the triangular prism sleeve 65, the drill rod tail 13 can be driven to rotate when the large gear 61 rotates.

[0094] Furthermore, both the head and the tail of the large gear 61 are in contact with the inner cavity of the intermediate body 7, and Gleitrings 91 are also provided at the contact surfaces. The Gleitrings 91 isolate the cavity above the gearbox 58 (the third chamber) from the second chamber, effectively replacing the traditional skeleton oil seal and being able to withstand a greater oil pressure. At the contact surfaces between the large gear 61 and the inner cavity of the intermediate body 7 on the outer sides of the two Gleitrings 91, a plurality of guide rings 89 are further provided, which can effectively support the large gear 61 and enable it to maintain axial stability during operation, thereby extending its service life. Due to the presence of the Gleitrings 91, a sealed space is formed between the large gear 61 and the cavity above the gearbox 58 (the third chamber). Since lubrication is also required between the large gear 61 and the small gear 60, this sealed space can be used as the lubrication chamber 77, and the lubrication chamber 77 is connected to the leakage oil passage 51. During operation, the hydraulic oil for driving the cycloid motor 75 will leak into the lubrication chamber 77, and then can lubricate the small gear 60 and the large gear 61 and be discharged through the leakage oil passage 51.

[0095] The flushing assembly includes a machine head 9 and a flushing head 66. The flushing head 66 is arranged in the inner cavity of the machine head 9, and a drill rod tail copper sleeve 67 and a machine head copper sleeve 68 for preventing the axial displacement of the flushing head 66 are arranged in the machine head 9. The tail of the drill rod tail copper sleeve 67 abuts against the head of the stop ring 59, and the machine head copper sleeve 68 is embedded in the head cavity of the machine head 9. The drill rod tail 13 sequentially passes through the drill rod tail copper sleeve 67, the flushing head 66 and the machine head copper sleeve 68, and the drill rod tail copper sleeve 67 and the machine head copper sleeve 68 are used to further prevent the radial deviation of the drill rod tail 13 during impact and rotation, improving the working stability. U-shaped seals 69 for preventing the leakage of the flushing medium are arranged in both the flushing head 66 and the drill rod tail copper sleeve 67, and sealing rings for sealing with the machine head 9 are arranged outside both the head and the tail of the flushing head 66. A central hole 70 extending towards the head of the drill rod tail 13 is formed on the front section rod body of the drill rod tail 13, an annular flushing cavity 71 is formed on the inner cavity of the machine head 9, and a water passage hole 72 connecting the flushing cavity 71 and the central hole 70 is formed on the flushing head 66. At the same time, a flushing medium interface 73 (F) for injecting the flushing medium into the flushing cavity 71 is arranged on the machine head 9. Furthermore, a protective cover 74 through which the drill rod tail 13 passes is arranged on the head of the machine head 9.

[0096] During the impact and rotation operation of the drill rod tail 13, the flushing water is injected through the flushing medium interface 73 (F). The flushing water enters the flushing cavity 71 and then enters the cavity formed between the flushing head 66 and the drill rod tail 13 through the water passage hole 72. Due to the presence of the U-shaped seals 69 inside the head and the tail of the flushing head 66, the flushing water enters the central hole 70 on the drill rod tail 13 to flush the central hole 70 and cool the drill rod tail 13 and then is discharged through the central hole 70.

[0097] In practical applications, part of the flushing water enters the shank bushing 67 through the U-shaped seal 69 at the tail of the flushing head 66. At this time, a flushing water leakage chamber 78 is formed between the U-shaped seal 69 in the shank bushing 67 and the U-shaped seal 69 at the tail of the flushing head 66. In order to drain the water in the flushing water leakage chamber 78, a circular return water chamber 79 is formed on the inner wall of the machine head 9 outside the contact portion between the shank bushing 67 and the flushing head 66. A plurality of drainage ports 80 communicating with the return water chamber 79 are formed around the shank bushing 67, and a plurality of drainage channels 81 communicating with the return water chamber 79 are formed on the machine head 9. Then, after there is flushing water in the flushing water leakage chamber 78, it can be discharged outside the machine body through the drainage ports 80, the return water chamber 79, and the drainage channels 81.

[0098] Meanwhile, in order to lubricate the area formed by the shank 13, the machine head bushing 68, the flushing head 66, and the machine head 9, as well as the area between the U-shaped seal 69 in the shank bushing 67 and the U-shaped seal 69 at the tail of the flushing head 66, two oil injection ports 82 are formed on the machine head 9, and oil injection plugs 83 are installed in the oil injection ports 82; one of the oil injection ports 82 is communicated with the return water chamber 79; the other oil injection port 82 is communicated with the contact surface between the flushing head 66 and the machine head bushing 68.

[0099] The lubricating oil is injected when the hydraulic rock drill is in a non-working state. One portion of the lubricating oil is injected through the oil injection plug 83 and the oil injection port 82 communicated with the return water chamber 79, and enters the flushing water leakage chamber 78 through the return oil chamber 79 and the drainage port 80, so as to lubricate the area between the U-shaped seal 69 in the shank bushing 67 and the U-shaped seal 69 at the tail of the flushing head 66; the other portion of the lubricating oil is injected through the oil injection plug 83 and the oil injection port 82 communicated with the contact surface between the flushing head 66 and the machine head bushing 68. Since no sealing parts are provided at the contact surface between the flushing head 66 and the machine head bushing 68 and between the machine head bushing 68 and the machine head 9, the lubricating oil can enter the gap and then lubricate the area formed by the shank 13, the machine head bushing 68, the flushing head 66, and the machine head 9.

[0100] When the hydraulic rock drill performs impact and rotation operations, dust will adhere to the surface of the machine body. Therefore, part of the dust will enter the machine body along the gaps between the contact surfaces of the rear cover 5 and the cylinder block 6, the cylinder block 6 and the intermediate body 7, the intermediate body 7 and the gearbox cover 8, the gearbox cover 8 and the machine head 9, the contact surface between the cycloidal motor 75 and the intermediate body 7 (gearbox 58), and between the head of the shank 13 and the machine head bushing 68; meanwhile, during the operation, the temperature of the components inside the machine body will rise, and too high a temperature will affect the service life of the components.

[0101] Based on this, air passage 87 is provided in the rear cover 5, cylinder block 6, intermediate body 7, gearbox cover 8, and machine head 9; and a ring-shaped purging air chamber 84 is formed radially in the machine head 9 outside the machine head copper sleeve 68, and a plurality of purging air holes 85 for connecting the purging air chamber 84 and the gap between the machine head copper sleeve 68 and the drill rod tail 13 are circumferentially provided on the machine head copper sleeve 68; at the same time, a ring-shaped air passage 88 is formed in the second chamber at the contact position between the large gear 61 and the buffer piston 54, and the impact piston 12 also has a central passage. The interface (AIR) of the air passage 87 is provided on the rear cover 5. After the purging air enters through the interface of the air passage 87, a part of the gas first passes through the air passage 87 and is guided to the contact surface between the rear cover 5 and the cylinder block 6 and blows out from the contact surface between the rear cover 5 and the cylinder block 6. The remaining gas continues to move forward along the air passage 87, and a part of the gas is guided through a branch passage connected to the air passage 87 to the contact surface between the accumulator 55 on both sides of the cylinder block 6 and the cylinder block 6 and blows out from the contact surface between the accumulator 55 and the cylinder block 6. The remaining gas continues to move forward along the air passage 87 and enters the air passage 88. The air passage 87 on the cylinder block 6 for introducing purging air into the air passage 88 and the air passage 87 on the intermediate body 7 are located on opposite sides, and then the purging air can act on the entire air passage 88 to fully cool the cylinder liner 16; the purging air further guides the gas into the contact surfaces between the buffer piston 54, the large gear 61, and the rear drill rod retaining sleeve 53 through the subsequent air passage 87 connected to the air passage 88 and enters through the gaps at the contact surfaces, and then can contact components such as the impact piston 12 and the drill rod tail 13 to cool them; further, the intermediate body 7 has an air guiding passage connecting the area at the contact surface between the buffer piston 54, the large gear 61, and the rear drill rod retaining sleeve 53 to the contact surface between the cycloid motor 75 and the intermediate body 7 (gearbox 58). Therefore, the purging air entering the area at the contact surface between the buffer piston 54, the large gear 61, and the rear drill rod retaining sleeve 53 can enter the contact surface between the cycloid motor 75 and the intermediate body 7 (gearbox 58) through the air guiding passage and purge it. At the same time, there is also a gap between the drill rod tail 13 and the triangular sleeve 65. Therefore, the entering purging air can enter the cavity between the triangular sleeve 65 and the stop ring 59 through the gap between the drill rod tail 13 and the triangular sleeve 65, and enter the purging air chamber 84 through the gaps formed among the gearbox cover 8, the machine head 9, the stop ring 59, and the large gear 61 and the subsequent air passage 87 connected to the gap, and is guided to the gap between the drill rod tail 13 and the machine head copper sleeve 68 through the purging air holes 85 for air purging; furthermore, a branch passage for guiding the purging air to the contact surface between the intermediate body 7 and the gearbox cover 8 is formed at the gearbox cover 8, and the purging air will pass through the contact surface between the gearbox cover 8 and the machine head 9 on the path of guiding to the head of the drill rod tail 13. Therefore, there will be purging air blowing out through the two contact surfaces to achieve air blowing.

[0102] To prevent the purging gas from entering the hydraulic oil cavity at the rear side of the piston front guide sleeve 19 and the front seal guide sleeve 20, an oil seal 90 is also embedded in the head of the front seal guide sleeve 20, and the impact piston 12 passes through the oil seal 90. An inner sunken ring groove is formed inwardly on the oil seal 90. The tail of the oil seal 90 is embedded in the front seal guide sleeve 20, and the head of the front seal guide sleeve 20 is embedded in the inner sunken ring groove. In addition to preventing the purging gas from entering the rear hydraulic oil cavity, when a gap is generated due to wear of the stern seal 22 between the front seal guide sleeve 20 and the impact piston 12, the oil seal 90 can further prevent the leakage of hydraulic oil.

[0103] The piston impact process is further introduced below.

[0104] Stroke, commutation

[0105] First stage: The high-pressure hydraulic oil enters the rear-end high-pressure oil cavity 23 through the impact oil inlet interface 25(P) on the rear cover 5, and the high-pressure oil enters the communication channel 27. At this time, the valve body 15 closes the inner port of the communication channel 27, and the high-pressure oil will enter the left-end chamber of the rear push channel 28 communicated with the communication channel 27. Then, since the front push channel 38 is communicated with the front-end oil return cavity 32, the middle oil return cavity 30, the rear-end oil return cavity 29, and the rear-end total oil return cavity 24 and is connected to the impact oil return interface 26(T) on the rear cover 5, there is no high-pressure oil in the right-end chamber of the front push channel 38.

[0106] Second stage: High-pressure oil always enters the left-end chamber of the rear push channel 28 to push the rear push rod 39 to axially displace to the right, and then push the valve body 15 to axially displace to the right. After the valve body 15 displaces to the right and abuts against the tail of the cylinder sleeve 16, the gap originally having between the head of the valve body 15 and the tail of the cylinder sleeve 16 and communicating the inner cavity of the valve body 15 with the middle oil return cavity 30 is closed. At this time, the communication channel 27 and the inner cavity of the head of the valve sleeve 14 are conducted, so that the high-pressure oil can enter the inner cavity of the head of the valve sleeve 14. Then, since the force-receiving area of the force-receiving surface A43 is larger than the force-receiving area of the force-receiving surface B46, the impact piston 12 is pushed to axially displace to the right.

[0107] Third stage: During the forward movement of the impact piston 12, when the cross-section B45 crosses the front end face of the inner table stage D47, the high-pressure oil in the front high-pressure oil chamber 33 enters the front oil return chamber 32 and enters the right end chamber of the forward push channel 38. Since the diameter of the front push rod 40 is greater than that of the rear push rod 39, under the condition of equal pressure, the front push rod 40 will push the valve body 15 to move left until the valve body 15 closes the inner port of the communication channel 27 again. At this time, the gap originally existing between the head of the valve body 15 and the tail of the cylinder liner 16 for connecting the inner cavity of the valve body 15 and the rear oil return chamber 29 is restored, so that the hydraulic oil in the inner cavity of the valve body 15 can enter the rear oil return chamber 29 through the gap, and then the force-receiving surface A43 has no pressure. The force-receiving surface C44 is subjected to the high-pressure oil that enters the front oil return chamber 32 from the front high-pressure oil chamber 33 and acts on the force-receiving surface C44 through the gap between the impact piston 12 and the cylinder liner 16, so that the impact piston 12 decelerates until it hits the drill tail 13 and reverses. After being hit, the drill tail 13 will move rightward to impact the target object.

[0108] Return stroke, commutation

[0109] First stage: After the impact piston 12 commutes, since only the force-receiving surface C44 is subjected to the oil pressure, the impact piston 12 accelerates to move leftward at this time. During the leftward movement of the impact piston 12, when the cross-section B45 crosses the front end face of the inner table stage D47, only the force-receiving surface B46 is subjected to the oil pressure at this time. Since the area of the force-receiving surface B46 is smaller than that of the force-receiving surface A43, the acceleration of the impact piston 12 during the return stroke movement decreases at this time.

[0110] Second stage: During the continuous leftward movement of the impact piston 12, when the force-receiving surface C44 crosses the front end face of the intermediate oil return chamber 30, the high-pressure oil originally existing in the right end chamber of the forward push channel 38 enters the intermediate oil return chamber 30, reducing the leftward acting force on the front push rod 40; since the left end chamber of the rear push channel 28 always has high-pressure oil entering, which will push the valve body 15 to the right, so the valve body 15 moves to the right at this time. When it reaches a certain position, a sealed space filled with hydraulic oil will be formed by the impact piston 12, the valve sleeve 14, the valve body 15, and the cylinder liner 16, causing the impact piston 12 to brake.

[0111] When the valve body 15 continues to move rightward, the inner port of the communication channel 27 is opened, and the high-pressure oil enters the inner cavity of the head of the valve sleeve 14, acting on the force-receiving surface A43, causing the impact piston 12 to commute and start a new stroke movement.

[0112] The above is only the preferred embodiment of the utility model patent. It should be noted that for those of ordinary skill in the art, without departing from the principle of the utility model patent, several improvements and retouches can still be made, and these improvements and retouches should also be regarded as the protection scope of the utility model patent.

Claims

1. A hydraulic rock drill, characterized in that: The machine body comprises a machine tail portion, a cylinder portion, an intermediate portion and a machine head portion connected in sections, wherein the machine tail portion and the cylinder portion together constitute an impact assembly; the intermediate portion comprises a rotary assembly and a buffer assembly, and the machine head portion comprises a flushing assembly; The impact assembly and the buffer assembly together form a first chamber for accommodating the impact piston; the rotary assembly and the flushing assembly together form a second chamber for accommodating the shank tail, and the first chamber is connected to the second chamber; The impact assembly introduces hydraulic oil into the first chamber, and the impact piston can reciprocate along the central axis of the first chamber under the push of the hydraulic oil, and the head of the impact piston can pass through the first chamber into the second chamber and hit the tail of the shank; The tail of the shank tail is inserted into the rotary assembly and the shank tail is driven to rotate forward or reverse along the central axis through the rotary assembly; The buffer assembly comprises a rear stop sleeve of the drill tail and a buffer piston; the rear stop sleeve of the drill tail abuts against the rear part of the drill tail to limit the axial displacement of the drill tail backwards; an annular buffer cavity is formed radially in the second chamber located in the middle body, and the buffer piston is installed at the front end of the second chamber and closes the buffer cavity; the buffer cavity is filled with hydraulic oil that can push the buffer piston to move forward axially to abut against the rear stop sleeve of the drill tail; when the drill tail rebounds, it hits the rear stop sleeve of the drill tail and acts on the buffer piston, and the buffer piston is hit by the rear stop sleeve of the drill tail and moves axially backwards and squeezes the hydraulic oil out of the buffer cavity; A center hole extending toward the head of the shank is formed on the front section of the rod body of the shank, and the flushing assembly injects a flushing medium into the center hole.

2. The hydraulic rock drill according to claim 1, characterized in that: The cylinder body portion includes a reversing mechanism, which includes a valve sleeve, a valve body, a cylinder sleeve and an impact piston; The head of the valve sleeve abuts against the tail of the cylinder sleeve, the valve body is installed in the inner cavity of the valve sleeve, the head of the cylinder sleeve extends into the tail cavity of the intermediate body and abuts against the intermediate body; the piston is installed in the inner cavity of the cylinder sleeve, and the inner cavity of the valve sleeve is connected with the inner cavity of the cylinder sleeve; The hydraulic oil pushes the valve body and the impact piston to reciprocate. When the valve body is axially displaced forward a preset distance, the hydraulic oil pushes the impact piston forward; when the impact piston is forward a preset distance, the hydraulic oil pushes the valve body to be axially displaced backward; when the valve body is axially displaced backward a preset distance, the hydraulic oil pushes the impact piston backward; when the impact piston is backward a preset distance, the hydraulic oil pushes the valve body to be axially displaced to the left, and the cycle repeats.

3. The hydraulic rock drill according to claim 2, characterized in that: An annular rear high-pressure oil chamber and an annular rear total oil return chamber are radially formed in sequence from the rear to the front between the first chamber and the valve sleeve; A rear oil return cavity is formed between the abutment portion of the inner cavity of the valve sleeve and the inner cavity of the cylinder sleeve and the valve body; An annular intermediate oil return chamber, a front oil return chamber and a front high-pressure oil chamber are radially formed in the cylinder sleeve from the rear to the front, and are isolated by the impact piston. The valve body closes the communication passage between the rear high-pressure oil chamber and the inner cavity of the valve sleeve. After the hydraulic oil is injected into the rear high-pressure oil chamber, the valve body is pushed forward to axially move and connect the rear high-pressure oil chamber with the inner cavity of the valve sleeve. The hydraulic oil enters the inner cavity of the valve sleeve and pushes the impact piston to axially move forward. When the impact piston moves forward a preset distance, the front high-pressure oil chamber is connected with the front reflux chamber, and the hydraulic oil pushes the valve body to move axially backward to close the communication channel between the rear high-pressure oil chamber and the inner cavity of the valve sleeve. The impact piston completes the impact and retreats backward under the action of the hydraulic oil. When the impact piston retreats a preset distance, the front end return chamber is connected with the middle oil return chamber, the rear end oil return chamber, and the rear end total oil return chamber; the high-pressure oil injected into the rear end high-pressure oil chamber pushes the valve body to move axially forward to connect the rear end high-pressure oil chamber with the valve sleeve inner cavity, and the hydraulic oil enters the valve sleeve inner cavity and pushes the impact piston to move axially forward, and the cycle repeats.

4. The hydraulic rock drill according to claim 3, characterized in that: A plurality of backward push passages are distributed axially and circumferentially in the head of the valve sleeve, and are connected to the rear high-pressure oil chamber, the inner chamber of the valve sleeve, and the rear oil return chamber; A plurality of forward thrust passages are axially and circumferentially arranged in the rear end of the cylinder sleeve and are connected to the rear end oil return chamber and the front end oil return chamber. A rear push rod and a front push rod for pushing the valve body to axially shift are respectively slidably arranged in the rear push channel and the front push channel, and the diameter of the front push rod is larger than that of the rear push rod.

5. The hydraulic rock drill according to claim 3, characterized in that: The buffer assembly also includes a plurality of accumulators installed outside the cylinder body; The impact assembly and the buffer assembly together form a plurality of oil inlet channels for supplying hydraulic oil to the rear high-pressure oil chamber, the front high-pressure oil chamber and the buffer chamber; The impact assembly is formed with an oil outlet passage for discharging the hydraulic oil in the rear end total return oil chamber; The rear high-pressure oil chamber, the front high-pressure oil chamber and the buffer chamber are all connected to the liquid phase side of the accumulator through the oil inlet channel.

6. The hydraulic rock drill according to claim 5, characterized in that: The reversing mechanism also includes a sealing assembly arranged in the inner cavity of the tail of the valve sleeve and the inner cavity of the head of the cylinder body for preventing leakage of hydraulic oil; a leakage oil cavity is formed between the sealing assembly and the corresponding inner cavity of the valve sleeve and the inner cavity of the cylinder body respectively; The impact assembly is formed with a leakage oil channel, and the leakage oil chamber is communicated with the leakage oil channel for discharging the leakage oil.

7. The hydraulic rock drill according to claim 6, characterized in that: The rotary assembly includes a cycloidal motor, a pinion, a large gear and a stop ring; the rotary assembly also forms a third chamber for accommodating the pinion; The large gear is installed in the second chamber and isolates the third chamber from the second chamber. The tail of the large gear abuts against the head of the buffer piston. The rear stopper sleeve of the shank tail is slidably arranged in the inner cavity of the tail of the large gear. The stop ring is embedded in the tail of the machine head and is coaxially arranged with the shank tail, and the head of the large gear abuts against the tail of the stop ring. The shank tail is inserted through the stop ring, and the tail end of the shank tail is located in the inner cavity of the large gear head and will not fall off the large gear after being hit; There is no rotational cooperation between the drill tail and the large gear, the large gear and the small gear mesh with each other, and the cycloidal motor is used to drive the small gear to rotate forward or reverse, and then drive the large gear and the drill tail to rotate synchronously; A lubrication chamber is formed between the large gear and the third chamber, and the lubrication chamber is connected to the leakage oil channel; the hydraulic oil driven by the cycloid motor leaks into the lubrication chamber to lubricate the small gear and the large gear and is discharged through the leakage oil channel.

8. The hydraulic rock drill according to claim 7, characterized in that: An annular flushing cavity is radially formed in the second cavity located in the head of the machine; The flushing assembly includes a flushing head, which is installed in the head of the machine and closes the flushing cavity; The flushing assembly also includes a brazing tail copper sleeve and a machine head copper sleeve, which are arranged at the rear side of the tail of the flushing head and the front side of the head to prevent the brazing tail from radially deviating; the flushing head, the brazing tail copper sleeve and the machine head copper sleeve are all sleeved outside the brazing tail; The head of the machine is formed with a water inlet channel connected with the flushing cavity, and the flushing head is formed with a channel penetrating with the central hole of the shank tail, and the flushing medium is injected into the central hole through the water inlet channel; Two U-shaped seals are provided in the flushing head to prevent leakage of the flushing medium entering the cavity between the shank and the flushing head. The head of the brazing tail copper sleeve is in contact with the U-shaped seal in the cavity at the tail of the flushing head, and a leakage chamber is formed between the brazing tail and the brazing tail for accommodating the flushing medium leaking from the cavity between the brazing tail and the flushing head; A liquid return chamber is formed between the brazing tail copper sleeve and the second chamber located at the machine head, the leakage chamber is connected to the liquid return chamber, and a drainage channel for discharging the flushing medium in the liquid return chamber is provided on the machine head; The machine head is formed with two lubrication channels, and lubricating oil is injected into the two lubrication channels to lubricate the gap between the machine head and the machine head copper sleeve, the flushing head, the shank tail and the U-shaped seal in the leakage chamber.

9. The hydraulic rock drill according to claim 8, characterized in that The intermediate body portion includes an intermediate body and a gear box cover; The tail, cylinder, intermediate, gearbox cover and head are abutted in sequence, and dust rings are arranged at the abutting surfaces of the tail, cylinder, intermediate, gearbox cover and head, the abutting surfaces of the cylinder and accumulator, and the abutting surfaces of the cycloid motor and the intermediate; The tail, cylinder, intermediate, gear box cover, cycloidal motor and head of the machine together form an air passage, and a ring-shaped air chamber connected to the air passage is formed in the second chamber where the large gear and the buffer piston abut. The impact piston also has a central channel. The purge gas is introduced into the air passage, and is blown out through the tail, cylinder, intermediate, gear box cover, the abutting surface of the head, the abutting surface of the cylinder and the accumulator, the abutting surface of the cycloid motor and the intermediate, and the gap between the head of the drill tail and the copper sleeve of the machine head for air purge; and enters the gap between the impact piston and the buffer piston, the gap between the rear stop sleeve of the drill tail, the cavity formed between the impact piston and the tail, and the gap between the drill tail and the large gear through the air passage for air cooling.

10. The hydraulic rock drill according to claim 9, characterized in that The interfaces of the oil inlet channel, oil outlet channel, leakage oil channel and air outlet channel are all opened at the tail of the tail of the machine; The head and tail of the large gear are both fitted with the inner cavity of the intermediate body, and a Gly ring is provided at the fitting surface, and the third chamber is isolated from the second chamber by the Gly ring; A plurality of guide rings are also arranged at the fitting surfaces between the large gear located outside the two grid circles and the inner cavity of the intermediate body.

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