Hydraulic rock drill impact assembly and impact method

Abstract

The invention provides a hydraulic rock drill impact assembly and an impact method, and belongs to the technical field of rock drills. The hydraulic rock drill impact assembly comprises an impact shell, a piston hammer body and two reversing sleeves; a high-pressure stroke oil duct, a high-pressure return oil duct, a low-pressure stroke oil duct, a low-pressure return oil duct and a pilot oil duct are arranged in the impact shell; the piston hammer body is provided with a sealing part, and the sealing part divides the piston hammer body into a stroke action cavity and a return action cavity; the stroke action cavity is communicated with the high-pressure stroke oil duct and the low-pressure stroke oil duct, and the return action cavity is communicated with the high-pressure return oil duct and the low-pressure return oil duct; the two ends of the piston hammer body are sleeved with the two reversing sleeves correspondingly. The reversing sleeve is in sliding fit with the impact shell, and a front driving cavity, a buffering cavity and a rear driving cavity are formed between the reversing sleeve and the impact shell; the front driving cavity is communicated with the pilot oil duct; through the arrangement, a complex oil duct does not need to be machined on the piston hammer body, the structure of the piston hammer body can be simplified, and the machining difficulty of the piston hammer body is reduced.

Description

Technical Field

[0001] This application belongs to the field of rock drill technology, specifically relating to a hydraulic rock drill impact assembly and impact method. Background Technology

[0002] Rock drills are tools used for quarrying stone. They can also be used to break through hard layers such as concrete. Rock drills are classified into pneumatic rock drills, internal combustion rock drills, electric rock drills, and hydraulic rock drills. Among them, hydraulic rock drills rely on hydraulic oil to drive an impact piston to impact a steel chisel, thereby achieving the action of chiseling rocks.

[0003] Hydraulic rock drills use high-pressure fluid to drive a pendulum to reciprocate, converting fluid pressure into mechanical impact energy, which is then transmitted to the rock in the form of waves by the drill bit, thus achieving the purpose of rock breaking. In the existing technology, the impact mechanism of hydraulic rock drills requires the piston hammer to reciprocate within the impact housing to achieve the impact purpose.

[0004] The outer peripheral wall of the piston hammer needs to be sealed to the inner peripheral wall of the impact housing. Several oil passages are provided at intervals on the outer peripheral wall of the piston hammer. The oil passages on the outer peripheral wall of the piston hammer cooperate with the oil passages on the impact housing. High-pressure oil and low-pressure oil can cooperate with different oil passages on the piston hammer. That is, the pressure oil switches back and forth between the stroke action chamber and the return action chamber to make the piston hammer slide back and forth.

[0005] However, the aforementioned piston hammer has a complex structure and is difficult to manufacture. Summary of the Invention

[0006] This application provides an impact assembly and impact method for a hydraulic rock drill, aiming to solve the problem of complex piston hammer structure in the prior art.

[0007] To achieve the above objectives, the technical solution adopted in this application is as follows: A hydraulic rock drill impact assembly is provided, comprising: The impact casing has a high-pressure stroke oil passage, a high-pressure return oil passage, a low-pressure stroke oil passage, a low-pressure return oil passage, and a pilot oil passage inside. The piston hammer body has a sealing component that is sealed and slidably fitted with the impact housing. The sealing component divides the piston hammer body into a stroke action chamber and a return action chamber. The stroke action chamber is connected to a high-pressure stroke oil passage and a low-pressure stroke oil passage, and the return action chamber is connected to a high-pressure return oil passage and a low-pressure return oil passage. Two reversing sleeves are respectively fitted onto the piston hammer body at the stroke action chamber and the return action chamber; the reversing sleeves are slidably fitted with the impact housing, and a front drive chamber, a buffer chamber and a rear drive chamber are formed between the reversing sleeves and the impact housing; the front drive chamber can alternately communicate with the low-pressure oil passage and the high-pressure oil passage, the buffer chamber is connected to the low-pressure oil passage, and the rear drive chamber is connected to the high-pressure oil passage. Specifically, when the reversing sleeve in the stroke action chamber closes the high-pressure stroke oil passage and opens the low-pressure stroke oil passage, the reversing sleeve in the return action chamber closes the low-pressure return oil passage and opens the high-pressure return oil passage.

[0008] In one possible implementation, there are two sealing components, with an oil guide cavity formed between the two sealing components; The impact housing has a pilot oil passage inside, which connects to the oil guide chamber and the front drive chamber of the two reversing sleeves. The oil guide chamber can alternately connect to the high-pressure oil passage and the low-pressure oil passage.

[0009] In one possible implementation, the outer peripheral wall of the reversing sleeve has a first boss, a second boss and a third boss in sequence along the axial direction, wherein the diameter of the first boss is smaller than the diameter of the second boss and the diameter of the first boss is larger than the diameter of the third boss. The front drive cavity is located between the first boss and the end of the reversing sleeve, the buffer cavity is located between the first boss and the second boss, and the rear drive cavity is located between the third boss and the other end of the reversing sleeve. When both the front drive cavity and the rear drive cavity are under high pressure, the thrust of the front drive cavity on the reversing sleeve is greater than the thrust of the rear drive cavity on the reversing sleeve.

[0010] In one possible implementation, the impact housing has a guide groove at the location of the buffer cavity that limits the sliding position of the second boss.

[0011] In one possible implementation, the impact housing has a low-pressure reversing oil passage and a high-pressure reversing oil passage, which are located on both sides of the connection between the pilot oil passage and the guide oil chamber. Specifically, when the low-pressure reversing oil passage is connected to the oil guide cavity, the sealing component closes the high-pressure reversing oil passage; when the high-pressure reversing oil passage is connected to the oil guide cavity, the sealing component closes the low-pressure reversing oil passage.

[0012] In one possible implementation, both ends of the piston hammer extend out of the impact housing, and the piston hammer is sealed to both ends of the impact housing.

[0013] In one possible implementation, the impact housing includes: The casing body has a high-pressure stroke oil passage, a high-pressure return oil passage, a low-pressure stroke oil passage, and a low-pressure return oil passage inside. The intermediate cylinder body is fitted inside the housing body; the intermediate cylinder body has through holes that communicate with the high-pressure stroke oil passage, the high-pressure return oil passage, the low-pressure stroke oil passage, and the low-pressure return oil passage; the intermediate cylinder body is provided with a pilot oil passage; The front cylinder block is located at the front end of the housing body; the front cylinder block has a through hole that slides and seals with the piston hammer body; the front cylinder block has a through hole that communicates with the high-pressure return oil passage, the low-pressure return oil passage and the pilot oil passage.

[0014] The rear cylinder is located at the rear end of the housing body; the rear cylinder has a through hole that slides with the piston hammer and is sealed with the piston hammer; the rear cylinder has a through hole that communicates with the high-pressure return oil passage and the low-pressure return oil passage.

[0015] In one possible implementation, both the high-pressure stroke oil passage and the high-pressure return oil passage are connected to the high-pressure main oil passage, and both the low-pressure stroke oil passage and the low-pressure return oil passage are connected to the low-pressure main oil passage; wherein, an accumulator is connected to both the high-pressure main oil passage and the low-pressure main oil passage.

[0016] This application provides a hydraulic rock drill impact assembly. Compared with the prior art, by setting a front drive chamber, a buffer chamber, and a rear drive chamber between the reversing sleeve and the impact housing, the reversing sleeve can reciprocate along the axial direction of the impact housing. Through the cooperation of the two reversing sleeves, high-pressure oil can be alternately introduced into the stroke action chamber and the return action chamber, thereby causing the piston hammer to reciprocate within the impact housing to achieve the impact process. With the above-mentioned configuration of this application, only sealing components need to be machined on the piston hammer, without the need to machine complex oil passages on the piston hammer, which simplifies the structure of the piston hammer and reduces the machining difficulty of the piston hammer.

[0017] To achieve the above objectives, another technical solution adopted in this application is: An impact method is provided, wherein the reversing sleeve of the return stroke chamber is a front reversing sleeve, the reversing sleeve of the stroke chamber is a rear reversing sleeve, the sealing component on the piston hammer body near the front reversing sleeve is a front seal, and the sealing component on the hammer body near the rear reversing sleeve is a rear seal; the impact method includes the following steps: In the initial state, the piston hammer returns to its maximum position. At this time, the front reversing sleeve closes the high-pressure return oil passage and opens the low-pressure return oil passage; the rear reversing sleeve closes the low-pressure stroke oil passage and opens the high-pressure stroke oil passage; the front seal closes the high-pressure reversing oil passage and the rear seal opens the low-pressure reversing oil passage. Outward acceleration impact: The stroke action chamber is filled with high-pressure oil, while the return action chamber, pilot oil passage, guide oil chamber and front drive chamber are filled with low-pressure oil. Driven by the high-pressure oil in the stroke action chamber, the piston hammer accelerates outward and slides until it hits the tail end of the chisel. After the rear seal closes the low-pressure reversing oil passage, the front seal opens the high-pressure reversing oil passage. At this time, the guide oil chamber, pilot oil passage, and front drive chamber are all filled with high-pressure oil. The front reversing sleeve and the rear reversing sleeve slide backward under the pressure of the front drive chamber. After the front reversing sleeve and the rear reversing sleeve slide backward into place, the front reversing sleeve closes the low-pressure return oil passage and opens the high-pressure return oil passage; the rear reversing sleeve closes the high-pressure stroke oil passage and opens the low-pressure stroke oil passage. Inward acceleration during return stroke: The return stroke chamber is filled with high-pressure oil, while the stroke chamber is filled with low-pressure oil. Driven by the return stroke chamber, the piston hammer accelerates and slides inward. After the front seal closes the high-pressure reversing oil passage, the rear seal opens the low-pressure reversing oil passage; at this time, the guide oil chamber, pilot oil passage and front drive chamber are all low-pressure oil, and the front reversing sleeve and the rear reversing sleeve slide forward under the drive of the rear drive chamber. Inward deceleration return stroke: After the front reversing sleeve and the rear reversing sleeve slide into place, the front reversing sleeve closes the return high-pressure oil passage and opens the return low-pressure oil passage; the rear reversing sleeve closes the stroke low-pressure oil passage and opens the stroke high-pressure oil passage; at this time, the piston hammer body decelerates backward. After the piston hammer slides backward into position, it is in the initial state, and the above process is repeated.

[0018] The beneficial effects of the impact method provided in this application are the same as those of the impact assembly, and will not be repeated here. Attached Figure Description

[0019] Figure 1 A cross-sectional view of a hydraulic rock drill impact assembly provided in an embodiment of this application; Figure 2 A schematic diagram of the reversing sleeve portion of an impact assembly for a hydraulic rock drill, provided as an embodiment of this application; Figure 3 A schematic diagram of the second boss of a hydraulic rock drill impact assembly extruding oil into the guide groove to the left, as provided in an embodiment of this application; Figure 4 A schematic diagram of the second boss of a hydraulic rock drill impact assembly pressing oil to the right into the guide groove, provided for an embodiment of this application; Figure 5 A schematic diagram of the piston hammer of a hydraulic rock drill impact assembly in its initial state, provided in an embodiment of this application; Figure 6 A schematic diagram showing the connection between the pilot oil passage and the high-pressure reversing oil passage of a hydraulic rock drill impact assembly provided in an embodiment of this application; Figure 7 A schematic diagram of the piston hammer striking the tail end of a hydraulic rock drill impact assembly provided in this application embodiment; Figure 8A schematic diagram showing the piston hammer of a hydraulic rock drill impact assembly sliding to the right, provided in an embodiment of this application; Figure 9 A schematic diagram showing the connection between the pilot oil passage and the low-pressure reversing oil passage of a hydraulic rock drill impact assembly provided in an embodiment of this application; Figure 10 This is a schematic diagram showing the reversing sleeve of a hydraulic rock drill impact assembly sliding to the left in an embodiment of this application.

[0020] Explanation of reference numerals in the attached drawings: 1. Impact housing; 11. High-pressure stroke oil passage; 12. High-pressure return oil passage; 13. Low-pressure stroke oil passage; 14. Low-pressure return oil passage; 15. Sealing component; 151. Oil guide chamber; 16. Stroke action chamber; 17. Return action chamber; 18. Pilot oil passage; 19. High-pressure reversing oil passage; 191. Low-pressure reversing oil passage; 192. Guide groove; 2. Piston hammer body; 3. Reversing sleeve; 31. Front drive chamber; 32. Buffer chamber; 33. Rear drive chamber; 34. First boss; 35. Second boss; 36. Third boss; 4. High-pressure main oil passage; 5. Low-pressure main oil passage; 6. Housing body; 61. Positioning step; 62. Cover; 7. Middle cylinder block; 8. Front cylinder block; 81. Sealing ring; 82. Piston bushing; 9. Rear cylinder block. Detailed Implementation

[0021] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0022] Please refer to the following: Figures 1 to 10This application describes a hydraulic rock drill impact assembly. The hydraulic rock drill impact assembly includes an impact housing 1, a piston hammer 2, and two reversing sleeves 3. The impact housing 1 has a high-pressure stroke oil passage 11, a high-pressure return oil passage 12, a low-pressure stroke oil passage 13, and a low-pressure return oil passage 14. The piston hammer 2 has a sealing component 15 that seals and slides with the impact housing 1, dividing the piston hammer 2 into a stroke action chamber 16 and a return action chamber 17. The stroke action chamber 16 communicates with the high-pressure stroke oil passage 11 and the low-pressure stroke oil passage 13, and the return action chamber 17 communicates with the high-pressure return oil passage 12 and the low-pressure return oil passage 14. The two reversing sleeves 3... The reversing sleeve 3 is respectively fitted onto the piston hammer body 2 at the positions of the stroke action chamber 16 and the return action chamber 17; the reversing sleeve 3 is slidably fitted with the impact housing 1, forming a front drive chamber 31, a buffer chamber 32 and a rear drive chamber 33 between the reversing sleeve 3 and the impact housing 1; the front drive chamber 31 can alternately communicate with the low-pressure oil passage and the high-pressure oil passage, the buffer chamber 32 is connected to the low-pressure oil passage, and the rear drive chamber 33 is connected to the high-pressure oil passage; wherein, when the reversing sleeve 3 in the stroke action chamber 16 closes the high-pressure stroke oil passage 11 and opens the low-pressure stroke oil passage 13, the reversing sleeve 3 in the return action chamber 17 closes the low-pressure return oil passage 14 and opens the high-pressure return oil passage 12.

[0023] The hydraulic rock drill impact assembly provided in this application, compared with the prior art, enables the reversing sleeve 3 to reciprocate along the axial direction of the impact housing 1 by setting a front drive chamber 31, a buffer chamber 32, and a rear drive chamber 33 between the reversing sleeve 3 and the impact housing 1; through the cooperation of the two reversing sleeves 3, high-pressure oil can be alternately introduced into the stroke action chamber 16 and the return action chamber 17, thereby causing the piston hammer 2 to reciprocate within the impact housing 1 to realize the impact process; with the above-mentioned configuration of this application, only the sealing component 15 needs to be machined on the piston hammer 2, without the need to machine complex oil passages on the piston hammer 2, which simplifies the structure of the piston hammer 2 and reduces the machining difficulty of the piston hammer 2.

[0024] This application uses a reversing sleeve 3 to cooperate with the impact housing 1 to realize the reversing process. Furthermore, the reversing sleeve 3 in this application does not need to be provided with radial oil passage holes, which can improve the stability of the reversing sleeve 3.

[0025] The directional valve in this application adopts the form of directional sleeve 3, which is easy to process, thereby improving the processing accuracy of the entire impact assembly and achieving high efficiency and long service life of the impact assembly. When the directional sleeve 3 is damaged, it is easy to replace the directional sleeve 3. Compared with the prior art of setting oil passages on the piston hammer body 2, this application does not require replacing the entire piston hammer body 2, thus reducing material waste.

[0026] The reversing sleeve 3 in this application is small in size and light in weight, so the reversing sleeve 3 has high sensitivity and light impact force on the cylinder block.

[0027] In some embodiments, such as Figures 1 to 10 As shown, there are two sealing components 15, and an oil guide cavity 151 is formed between the two sealing components 15; the interior of the impact housing 1 also has a pilot oil passage 18, which connects the oil guide cavity 151 and two front drive cavities 31, and the oil guide cavity 151 can be connected to the low-pressure oil passage.

[0028] High-pressure stroke oil passage 11 and high-pressure return oil passage 12 are both connected to high-pressure main oil passage 4, and low-pressure stroke oil passage 13 and low-pressure return oil passage 14 are both connected to low-pressure main oil passage 5. Among them, accumulators are connected to both high-pressure main oil passage 4 and low-pressure main oil passage 5. By setting accumulators, the shock in the oil circuit can be absorbed to ensure the stability of the oil circuit.

[0029] The buffer chamber 32 is always connected to the low-pressure main oil passage 5, so the buffer chamber 32 is always in a low-pressure state; the rear drive chamber 33 is always connected to the high-pressure main oil passage 4, so the rear drive chamber 33 is always in a high-pressure state.

[0030] The front drive chamber 31 can switch between low pressure and high pressure. When the pilot oil passage 18 contains high pressure oil, the front drive chamber 31 is in a high pressure state; when the pilot oil passage 18 contains low pressure oil, the front drive chamber 31 is in a low pressure state.

[0031] The switching between high-pressure oil and low-pressure oil in the front drive chamber 31 is achieved through the cooperation of two sealing components 15 and high-pressure reversing oil passage 19 and low-pressure reversing oil passage 191, as detailed below: In some embodiments, such as Figure 1 As shown, the impact housing 1 has a low-pressure reversing oil passage 191 and a high-pressure reversing oil passage 19. The low-pressure reversing oil passage 191 and the high-pressure reversing oil passage 19 are located on both sides of the connection between the pilot oil passage 18 and the oil guide chamber 151. The high-pressure reversing oil passage 19 is always connected to the high-pressure main oil passage 4, and the low-pressure reversing oil passage 191 is always connected to the low-pressure main oil passage 5.

[0032] After one of the sealing components 15 closes the high-pressure reversing oil passage 19, the other sealing component 15 opens the low-pressure reversing oil passage 191. At this time, both the oil guide chamber 151 and the pilot oil passage 18 are filled with low-pressure oil. Since the pilot oil passage 18 is connected to the front drive chamber 31, the interior of the front drive chamber 31 is also filled with low-pressure oil.

[0033] After one of the sealing components 15 closes the low-pressure reversing oil passage 191, the other sealing component 15 opens the high-pressure reversing oil passage 19. At this time, both the oil guide chamber 151 and the pilot oil passage 18 are filled with high-pressure oil. Since the pilot oil passage 18 is connected to the front drive chamber 31, the interior of the front drive chamber 31 is also filled with high-pressure oil.

[0034] When both the front drive chamber 31 and the rear drive chamber 33 are filled with high-pressure oil, the thrust of the front drive chamber 31 on the reversing sleeve 3 is greater than the thrust of the rear drive chamber 33 on the reversing sleeve 3. The details are as follows: In some embodiments, such as Figures 1 to 10 As shown, the outer peripheral wall of the reversing sleeve 3 has a first boss 34, a second boss 35 and a third boss 36 in sequence along the axial direction. The diameter of the first boss 34 is smaller than the diameter of the second boss 35 and the diameter of the third boss 36 is larger than the diameter of the third boss 36. The front drive cavity 31 is located between the first boss 34 and the end of the reversing sleeve 3, the buffer cavity 32 is located between the first boss 34 and the second boss 35, and the rear drive cavity 33 is located between the third boss 36 and the other end of the reversing sleeve 3.

[0035] Since the diameter of the first boss 34 is larger than the diameter of the third boss 36, the end face area inside the front drive cavity 31 is larger than the end face area inside the rear drive cavity 33.

[0036] When both the current drive chamber 31 and the rear drive chamber 33 are connected to the high-pressure main oil passage 4, the thrust of the high-pressure oil on the end face of the first boss 34 is greater than the thrust of the high-pressure oil on the end face of the third boss 36. Therefore, the reversing sleeve 3 will slide towards the rear drive chamber 33.

[0037] In some embodiments, such as Figures 1 to 10 As shown, the impact housing 1 has a guide groove 192 at the position of the buffer cavity 32 to limit the sliding position of the second boss 35. Through the above-mentioned configuration of this application, the sliding position of the reversing sleeve 3 can be limited.

[0038] The second boss 35 slides within the guide groove 192, and the two ends of the guide groove 192 can limit the two extreme positions of the second boss 35.

[0039] When the second boss 35 slides to the front end of the guide groove 192, the reversing sleeve 3 in the return action chamber 17 closes the high pressure return oil passage 12 and opens the low pressure return oil passage 14; the reversing sleeve 3 in the stroke action chamber 16 closes the low pressure stroke oil passage 13 and opens the high pressure stroke oil passage 11.

[0040] When the second protrusion 35 slides to the rear end of the guide groove 192, the reversing sleeve 3 in the return action chamber 17 closes the low-pressure return oil passage 14 and opens the high-pressure return oil passage 12; the reversing sleeve 3 in the stroke action chamber 16 closes the high-pressure stroke oil passage 11 and opens the low-pressure stroke oil passage 13.

[0041] For example, the guide groove 192 has an annular groove. When the second boss 35 slides through the annular groove and squeezes the oil on one side of the guide groove 192, a buffer cavity is formed at this position. Through the gap between the outer peripheral wall of the second boss 35 and the inner peripheral wall of the guide groove 192, the squeezed oil can pass through the gap between the second boss 35 and the guide groove 192. With the above arrangement, the second boss 35 can play a buffering role. The final position of the second boss 35 can contact the end of the guide groove 192.

[0042] In some embodiments, such as Figures 1 to 10 As shown, the impact housing 1 includes a housing body 6, a middle cylinder 7, a front cylinder 8, and a rear cylinder 9.

[0043] The interior of the housing body 6 has a high-pressure stroke oil passage 11, a high-pressure return oil passage 12, a low-pressure stroke oil passage 13, and a low-pressure return oil passage 14.

[0044] The middle cylinder 7 is fitted inside the housing body 6; the middle cylinder 7 has through holes that communicate with the high-pressure stroke oil passage 11, the high-pressure return oil passage 12, the low-pressure stroke oil passage 13 and the low-pressure return oil passage 14 respectively.

[0045] The front cylinder block 8 and the rear cylinder block 9 are respectively connected to the two ends of the housing body 6; both the front cylinder block 8 and the rear cylinder block 9 have through holes that slide with the piston hammer 2 and are sealed with the piston hammer 2.

[0046] Both ends of the piston hammer 2 extend through the impact housing 1, and the piston hammer 2 and the impact housing 1 are sealed together. Specifically, a sealing ring 81 is provided between the front cylinder 8 and the piston hammer 2, and a sealing ring 81 is also provided between the rear cylinder 9 and the piston hammer 2. Through the above arrangement, the sealing performance between the piston hammer 2 and the front cylinder 8 and the rear cylinder 9 can be guaranteed.

[0047] A piston bushing 82 is connected between the front cylinder block 8 and the piston hammer 2, and a piston bushing 82 is also connected between the rear cylinder block 9 and the piston hammer 2; the piston bushing 82 is interference-fitted with the front cylinder block 8, and the piston bushing 82 is also interference-fitted with the rear cylinder block 9; the piston bushing 82 can guide the piston hammer 2.

[0048] The pilot oil passage 18 is located on the middle cylinder block 7, and the high-pressure reversing oil passage 19 and the low-pressure reversing oil passage 191 are located on the middle cylinder block 7.

[0049] The front cylinder block 8 is provided with a buffer chamber 32 and a return action chamber 17 position for the front drive chamber 31; the rear cylinder block 9 is provided with a buffer chamber 32 and a stroke action chamber 16 position for the rear drive chamber 33.

[0050] Taking the position on the middle cylinder block 7 that connects to the high-pressure stroke oil passage 11 as an example, the outer peripheral wall of the middle cylinder block 7 has an annular groove that connects to the high-pressure stroke oil passage 11, and the annular groove has at least one through hole arranged radially along the middle cylinder block 7; the outer peripheral wall of the rear cylinder block 9 also has an annular groove; the annular groove on the outer peripheral wall of the middle cylinder block 7 and the annular groove on the outer peripheral wall of the rear cylinder block 9 are connected through the through hole on the middle cylinder block 7, and the annular groove on the rear cylinder block 9 has a through hole that connects to the stroke action chamber 16 or the rear drive chamber 33; through the above arrangement, high-pressure oil can be guided to the stroke action chamber 16 or to the rear drive chamber 33.

[0051] The middle cylinder 7 has a stepped surface at the position of the return working chamber 17. The end of the front cylinder 8 can abut against the stepped surface of the middle cylinder 7, and the front cylinder 8 also has a stepped surface, forming a guide groove 192 between it and the middle cylinder 7.

[0052] The corresponding positions of the rear cylinder block 9 and the middle cylinder block 7 also form guide grooves 192, and the arrangement is the same as that of the front cylinder block 8 and the middle cylinder block 7, which will not be described in detail here.

[0053] The housing body 6 has a positioning step 61 at the position of the front cylinder 8 that contacts the end of the front cylinder. The housing body 6 has a cover 62 at the position of the rear cylinder 9. The cover 62 is fixed to the housing body by bolts. The end of the housing body has a threaded hole to facilitate fixing the cover 62 to the end of the housing body. The cover 62 has clearance space for the other end of the piston hammer 2 to slide.

[0054] Advantages of the impact assembly of this invention: 1. In this application, the structural dimensions of the piston hammer body 2 are easy to design for product series.

[0055] 2. In this application, the diameter of each functional area of ​​the piston hammer body 2 changes little, thereby reducing the stress peak during the impact process and extending the service life of the impact piston and the entire drill bit chain.

[0056] 3. This application has a small fluctuation in the impact return oil flow, which reduces return oil resistance and pressure pulsation.

[0057] Impact process: such as Figures 5 to 10 For ease of description, the reversing sleeve 3 of the return action chamber 17 is the front reversing sleeve 3, the reversing sleeve 3 of the stroke action chamber 16 is the rear reversing sleeve 3, the sealing component 15 on the piston hammer body 2 near the front reversing sleeve 3 is the front seal, and the sealing component 15 on the hammer body near the rear reversing sleeve 3 is the rear seal. In the initial state, the piston hammer 2 returns to the maximum position. At this time, the front reversing sleeve 3 closes the high pressure return oil passage 12 and opens the low pressure return oil passage 14; the rear reversing sleeve 3 closes the low pressure stroke oil passage 13 and opens the high pressure stroke oil passage 11; the front seal closes the high pressure reversing oil passage 19 and the rear seal opens the low pressure reversing oil passage 191. Outward acceleration impact: The stroke action chamber 16 contains high-pressure oil, while the return action chamber 17, pilot oil passage 18, guide oil chamber 151, and front drive chamber 31 contain low-pressure oil. Driven by the high-pressure oil in the stroke action chamber 16, the piston hammer 2 accelerates outward and slides until it hits the tail end of the chisel. After the rear seal closes the low-pressure reversing oil passage 191, the front seal opens the high-pressure reversing oil passage 19. At this time, the oil guide chamber 151, the pilot oil passage 18, and the front drive chamber 31 are all filled with high-pressure oil. The front reversing sleeve 3 and the rear reversing sleeve 3 slide backward under the pressure of the front drive chamber 31. After the front reversing sleeve 3 and the rear reversing sleeve 3 slide backward into place, the front reversing sleeve 3 closes the low-pressure return oil passage 14 and opens the high-pressure return oil passage 12. The rear reversing sleeve 3 closes the high-pressure stroke oil passage 11 and opens the low-pressure stroke oil passage 13. Inward acceleration during return stroke: The return stroke chamber 17 contains high-pressure oil, and the stroke chamber 16 contains low-pressure oil. The piston hammer 2 accelerates and slides inward under the drive of the return stroke chamber 17. After the front seal closes the high-pressure reversing oil passage 19, the rear seal opens the low-pressure reversing oil passage 191. At this time, the oil guide chamber 151, the pilot oil passage 18, and the front drive chamber 31 are all low-pressure oil. The front reversing sleeve 3 and the rear reversing sleeve 3 slide forward under the drive of the rear drive chamber 33. Inward deceleration return stroke: After the front reversing sleeve 3 and the rear reversing sleeve 3 slide into place, the front reversing sleeve 3 closes the return high-pressure oil passage and opens the return low-pressure oil passage; the rear reversing sleeve 3 closes the stroke low-pressure oil passage and opens the stroke high-pressure oil passage; at this time, the piston hammer 2 decelerates backward. After the piston hammer 2 slides backward into place, it is in the initial state; repeating the above process can achieve a continuous impact process.

[0058] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A hydraulic rock drill impact assembly, characterized in that, include: The impact casing has a high-pressure stroke oil passage, a high-pressure return oil passage, a low-pressure stroke oil passage, a low-pressure return oil passage, and a pilot oil passage inside. The piston hammer body has a sealing component that is sealed and slidably fitted with the impact housing. The sealing component divides the piston hammer body into a stroke action chamber and a return action chamber. The stroke action chamber is connected to a high-pressure stroke oil passage and a low-pressure stroke oil passage, and the return action chamber is connected to a high-pressure return oil passage and a low-pressure return oil passage. Two reversing sleeves are respectively fitted onto the piston hammer body at the stroke action chamber and the return action chamber; the reversing sleeves are slidably fitted with the impact housing, and a front drive chamber, a buffer chamber and a rear drive chamber are formed between the reversing sleeves and the impact housing; the front drive chamber can be alternately connected to the low-pressure oil passage and the high-pressure oil passage through the pilot oil passage of the impact housing, the buffer chamber is connected to the low-pressure oil passage, and the rear drive chamber is connected to the high-pressure oil passage; Specifically, when the reversing sleeve in the stroke action chamber closes the high-pressure stroke oil passage and opens the low-pressure stroke oil passage, the reversing sleeve in the return action chamber closes the low-pressure return oil passage and opens the high-pressure return oil passage.

2. The hydraulic rock drill impact assembly as described in claim 1, characterized in that, There are two sealing components, and an oil guide cavity is formed between the two sealing components; The pilot oil passage connects to the oil guide chamber and the front drive chamber of the two reversing sleeves. The oil guide chamber can be alternately connected to the high-pressure oil passage and the low-pressure oil passage.

3. The hydraulic rock drill impact assembly as described in claim 1, characterized in that, The outer peripheral wall of the reversing sleeve has a first boss, a second boss and a third boss in sequence along the axial direction. The diameter of the first boss is smaller than the diameter of the second boss and the diameter of the third boss is larger than the diameter of the third boss. The front drive cavity is located between the first boss and the end of the reversing sleeve, the buffer cavity is located between the first boss and the second boss, and the rear drive cavity is located between the third boss and the other end of the reversing sleeve. When both the front drive cavity and the rear drive cavity are under high pressure, the thrust of the front drive cavity on the reversing sleeve is greater than the thrust of the rear drive cavity on the reversing sleeve.

4. The hydraulic rock drill impact assembly as described in claim 3, characterized in that, The impact housing has a guide groove at the position of the buffer cavity to limit the sliding position of the second boss.

5. The hydraulic rock drill impact assembly as described in claim 2, characterized in that, The impact housing has a low-pressure reversing oil passage and a high-pressure reversing oil passage, which are located on both sides of the connection between the pilot oil passage and the oil guide chamber. Specifically, when the low-pressure reversing oil passage is connected to the oil guide cavity, the sealing component closes the high-pressure reversing oil passage; when the high-pressure reversing oil passage is connected to the oil guide cavity, the sealing component closes the low-pressure reversing oil passage.

6. The hydraulic rock drill impact assembly as described in claim 1, characterized in that, Both ends of the piston hammer extend through the impact housing, and the piston hammer and the two ends of the impact housing are sealed together.

7. The hydraulic rock drill impact assembly as described in claim 1, characterized in that, The impact housing includes: The casing body has a high-pressure stroke oil passage, a high-pressure return oil passage, a low-pressure stroke oil passage, and a low-pressure return oil passage inside. The intermediate cylinder body is fitted inside the housing body; the intermediate cylinder body has through holes that communicate with the high-pressure stroke oil passage, the high-pressure return oil passage, the low-pressure stroke oil passage, and the low-pressure return oil passage; the intermediate cylinder body is provided with a pilot oil passage; A front cylinder block is disposed at the front end of the housing body; the front cylinder block has a through hole that slides and seals with the piston hammer body; the front cylinder block has a through hole that communicates with the high-pressure return oil passage, the low-pressure return oil passage and the pilot oil passage. The rear cylinder is located at the rear end of the housing body; the rear cylinder has a through hole that slides with the piston hammer and is sealed with the piston hammer; the rear cylinder has a through hole that communicates with the high-pressure return oil passage and the low-pressure return oil passage.

8. The hydraulic rock drill impact assembly as described in claim 1, characterized in that, The high-pressure stroke oil passage and the high-pressure return oil passage are both connected to the high-pressure main oil passage, and the low-pressure stroke oil passage and the low-pressure return oil passage are both connected to the low-pressure main oil passage; wherein, an accumulator is connected to both the high-pressure main oil passage and the low-pressure main oil passage.

9. An impact method for the hydraulic rock drill impact assembly as described in claim 5, characterized in that, The reversing sleeve of the return stroke chamber is the front reversing sleeve, and the reversing sleeve of the stroke chamber is the rear reversing sleeve. The sealing component on the piston hammer body near the front reversing sleeve is the front seal, and the sealing component on the hammer body near the rear reversing sleeve is the rear seal. The impact method includes the following steps: In the initial state, the piston hammer returns to its maximum position. At this time, the front reversing sleeve closes the high-pressure return oil passage and opens the low-pressure return oil passage; the rear reversing sleeve closes the low-pressure stroke oil passage and opens the high-pressure stroke oil passage; the front seal closes the high-pressure reversing oil passage and the rear seal opens the low-pressure reversing oil passage. Outward acceleration impact: The stroke action chamber is filled with high-pressure oil, while the return action chamber, pilot oil passage, guide oil chamber and front drive chamber are filled with low-pressure oil. Driven by the high-pressure oil in the stroke action chamber, the piston hammer accelerates outward and slides until it hits the tail end of the chisel. After the rear seal closes the low-pressure reversing oil passage, the front seal opens the high-pressure reversing oil passage. At this time, the guide oil chamber, pilot oil passage, and front drive chamber are all filled with high-pressure oil. The front reversing sleeve and the rear reversing sleeve slide backward under the pressure of the front drive chamber. After the front reversing sleeve and the rear reversing sleeve slide backward into place, the front reversing sleeve closes the low-pressure return oil passage and opens the high-pressure return oil passage; the rear reversing sleeve closes the high-pressure stroke oil passage and opens the low-pressure stroke oil passage. Inward acceleration during return stroke: The return stroke chamber is filled with high-pressure oil, while the stroke chamber is filled with low-pressure oil. Driven by the return stroke chamber, the piston hammer accelerates and slides inward. After the front seal closes the high-pressure reversing oil passage, the rear seal opens the low-pressure reversing oil passage; at this time, the guide oil chamber, pilot oil passage and front drive chamber are all low-pressure oil, and the front reversing sleeve and the rear reversing sleeve slide forward under the drive of the rear drive chamber. Inward deceleration return stroke: After the front reversing sleeve and the rear reversing sleeve slide into place, the front reversing sleeve closes the return high-pressure oil passage and opens the return low-pressure oil passage; the rear reversing sleeve closes the stroke low-pressure oil passage and opens the stroke high-pressure oil passage; at this time, the piston hammer body decelerates backward. After the piston hammer slides backward into position, it is in the initial state. Repeat the above steps.

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