Impact device of rock drill and rock drill

Abstract

The present application discloses an impact device for a rock drill, comprising a front stop sleeve, a cylinder sleeve, and at least two rear stop sleeves. The front stop sleeve and any one of the rear stop sleeves are coaxially connected to the cylinder sleeve in sequence. The rear stop sleeves define a stop groove adapted for a drill tool. The rear end of the drill tool is positioned within the cavity formed by the front and rear stop sleeves. The bottom surface of the stop groove limits the rearward movement of the drill tool. The depth of the stop groove on each rear stop sleeve varies along the axial direction of the rear stop sleeve. Standardized rear stop sleeves facilitate power adjustment by simply replacing the rear stop sleeve.

Description

Technical Field

[0001] The present application relates to the field of rock drills, and in particular to an impact device of a rock drill and a rock drill. Background Art

[0002] A rock drill is a tool used for directly mining stone. It creates blastholes in the rock formation for explosives to be placed to blast the rock apart, thereby completing stone mining or other stonework operations. A rock drill operates on the principle of impact crushing. During operation, the piston reciprocates at high frequency, continuously striking the drill adapter. Under the impact force, the sharp, wedge-shaped drill bit crushes the rock and penetrates it to a certain depth, creating an indentation. After the piston retracts, the drill bit rotates a certain angle, and the piston moves forward again, striking the drill adapter again, creating a new indentation. The fan-shaped rock between the two indentations is sheared by the horizontal force generated by the drill bit. The piston continuously strikes the drill adapter, and compressed air or water is continuously fed through the center hole of the drill bit to expel the rock debris, thus forming a circular drill hole of a certain depth.

[0003] Related technologies, such as the "Hydraulic Hammer with a Static Suspended Piston," disclosed in application number CN202210577445.0, include a piston, cylinder, rod holder, inner sleeve, outer sleeve, and rod. The piston reciprocates within the cylinder, striking the rod. The rod holder houses the rock-breaking rod, along with an inner sleeve and outer sleeve, which serve as guides and protect the rod holder from wear. The area where the cylinder and piston head meet is equipped with at least two circles of static suspension chambers, each with at least two uniformly distributed chambers, to support the piston.

[0004] The existing rock drill's punching piston is primarily concerned with lubrication and impact force. Adjusting the equipment's frequency and impact energy is typically accomplished using a hydraulic system. For example, the "Hydraulic Control System for Continuously Adjustable Rock Drill Power," disclosed in application number CN201410071079.7, discloses a variable displacement pump (LS) controlled by a control valve block, a throttle, and a pilot control handle. The control valve block includes a logic valve, a relief valve, a balancing valve, a hydraulic directional valve, a shuttle valve, and a pressure reducing valve. The present invention enables the rock drill's impact pressure to be continuously controlled between a set minimum and maximum impact pressures based on the angle of movement of the pilot operating handle. The balancing valve amplifies the control pressure of the operating handle, changing the variable displacement pump LS control pressure and the logic valve control pressure, allowing the rock drill's impact pressure to continuously vary between the set minimum and maximum impact pressures, thereby achieving continuous adjustment of the rock drill's impact power. The present invention can flexibly adjust the impact power of the rock drill under special rock conditions, save energy, achieve the best rock drilling effect, and improve the production efficiency of the rock drill.

[0005] In the prior art, the power regulation of the piston is generally changed from the hydraulic system. By changing the oil inlet pressure and flow of the hydraulic system to change the impact performance parameters of the rock drill, the impact energy and impact frequency of the rock drill will be reduced and increased at the same time. At the same time, there is a limitation that the pressure is too high and the hydraulic system has higher requirements. Therefore, the applicability is poor and it cannot meet various working conditions. The inventors of the present application have changed the structure of the impact device to quickly realize the power regulation of the impact device in the rock drill, and can achieve the improvement of the single parameters of impact energy and impact frequency under the premise of ensuring that the external oil supply pressure conditions remain unchanged (unchanged flow, unchanged pressure, and unchanged external system). In addition, although the change of the piston impact energy requires a change in stroke, resulting in a change in the total displacement of the cycle, since the frequency and impact energy change in opposite directions, it can be guaranteed that the total flow will not change significantly. Therefore, there is no need to modify the hydraulic system, and the adjustment is simpler. The existing system can be directly relied on to adjust the rock drill according to the working conditions to obtain suitable performance parameters. Summary of the Invention

[0006] The technical problem to be solved by the present application is to provide an impact device of a rock drill and a rock drill with a standardized rear stop sleeve. The power adjustment of the equipment can be completed by simply replacing the rear end stop sleeve, and the adjustment is convenient.

[0007] The technical solution adopted in this application is: an impact device of a rock drill, comprising a front stop sleeve, a cylinder sleeve and at least two rear stop sleeves, the front stop sleeve and any one rear stop sleeve being coaxially connected to the cylinder sleeve in sequence, a stop groove adapted to the drill tool being provided in the rear stop sleeve, the rear end of the drill tool being located in the cavity formed by the front stop sleeve and the rear stop sleeve, the bottom surface of the stop groove limiting the extreme position of the drill tool moving backward, and the depth of the stop groove provided on each rear stop sleeve in the axial direction of the rear stop sleeve being different.

[0008] Compared with the prior art, the advantage of the present application is that at least two rear stop sleeves are provided, and the stop grooves provided on each rear stop sleeve have different depths in the axial direction of the rear stop sleeve. The bottom surface of the stop groove limits the extreme position of the drill tool's rearward movement, and the extreme position of the drill tool at the rear end will affect the impact point of the piston during the entire working process. Adjusting the position of the piston's impact point affects the distance the piston moves, and thus affects the frequency of the piston impacting the drill tool; and the distance the piston moves in the oil directly affects the piston's energy storage (kinetic energy). The change of the rear stop sleeve enables the adjustment of the equipment's frequency and impact energy. The present application designs the rear stop sleeve as a standardized kit. The power adjustment of the equipment can be completed by simply replacing the rear stop sleeve, which is convenient for adjustment.

[0009] In some embodiments of the present application, the outer dimensions of each rear stop sleeve are completely consistent. The present application designs the rear stop sleeve as a standardized kit to avoid the outer dimensions from affecting the structure and function of the present application.

[0010] In some embodiments of the present application, the present application includes a head section and at least two tail sections, the head section is connected to any one of the tail sections to form a piston installed in the cylinder sleeve, and a first signal channel is provided on the tail section, and the first signal channel connects the outer peripheral surface of the piston with the rear end surface of the piston; the lengths of the first signal channels on different tail sections are different, and the tail sections correspond one-to-one to the rear stop sleeves.

[0011] In this application, the tail section is generally replaced simultaneously with the rear stop sleeve, and the dimensions of each tail section are exactly the same, the only difference being the length of the first signal path. That is, the tail section in this application is also a standardized kit.

[0012] Select the rear stop sleeve according to the working conditions, and select the corresponding piston tail section to ensure that the position of the first signal oil port is adjusted accordingly under the premise of changing the piston impact point, so as to ensure that the impact point of the rock drill is at the moment of maximum speed during the piston movement, so as to maximize the performance of the rock drill.

[0013] Specifically, if the distance for piston insertion in the mid-frequency rear stop sleeve is X, the length of the first signal channel (the distance from the piston's outer peripheral surface, connected to the piston's rear end face) is Y. Then, for the high-frequency rear stop sleeve, the distance for piston insertion is XN, and the length of the first signal channel is Y+N. For the low-frequency rear stop sleeve, the distance for piston insertion is X+M, and the length of the first signal channel is YM. Because the depth of the rear stop sleeve's retaining groove affects piston travel, the length of the first signal channel (the distance from the piston's rear end face) must be adjusted accordingly to ensure proper function of the signal fed back to the first signal port.

[0014] In some embodiments of the present application, the drill tool includes a mounting portion located at the rear end of the entire drill tool, having a diameter greater than that of other parts of the drill tool and configured to transmit rotation in conjunction with a spline or other means. The front stop sleeve and the rear stop sleeve are connected to form a limiting cavity for accommodating the mounting portion, and the limiting cavity limits the travel of the drill tool.

[0015] Specifically, the stop groove constitutes the limit cavity, and the limit cavity on different rear stop sleeves has different axial depths. The depth of the stop groove determines the length of the entire limit cavity, that is, the stroke length of the drill tool movement.

[0016] In some embodiments of the present application, the rear end face of the mounting portion is a truncated cone structure, and the rear end face of the mounting portion includes a flat surface and an inclined surface surrounding the outer ring of the flat surface. The flat surface of the rear end face of the mounting portion serves as an impact surface that contacts the piston, and the bottom surface of the retaining groove is adapted to the inclined surface of the rear end face of the mounting portion. In the present application, the design of the inclined surface also serves a certain guiding role, ensuring that the drilling tool and the piston are coaxial when the drilling tool moves backward to the extreme position.

[0017] In some embodiments of the present application, the piston is coaxially arranged with the drill tool, and the piston reciprocates in the cylinder sleeve to drive the drill tool to impact the rock wall.

[0018] The tail section is provided with a second signal channel, connecting the outer circumference of the piston with the rear end surface. During normal piston operation, the first signal port occasionally communicates with the first signal channel. The first signal channel provides a signal indicating normal piston operation. During dry operation (abnormal piston operation), the second signal port occasionally communicates with the first signal channel.

[0019] In some embodiments of the present application, the surface of the head section is provided with an anti-aircraft shaft space, and the anti-aircraft shaft space includes several coaxially arranged rings, and there is a distance between two adjacent rings; the nominal diameter value of the rings is equal to the dead space diameter of the cylinder liner.

[0020] The piston is provided with an anti-air striking shaft space and cooperates with the dead space of the cylinder liner. Before the air striking tool hits the front stop sleeve, the piston enters the dead space to consume energy in advance, thereby reducing damage to components.

[0021] The outer diameter of the rings increases from near the drill tool to far from the drill tool; the diameter of the ring farthest from the drill tool is equal to the dead space diameter of the cylinder. Preferably, the anti-aircraft axle space of the present application includes at least three coaxially arranged rings. The anti-aircraft axle space divides the entire braking process into at least three stages, with the gap gradually decreasing, which can effectively ensure smooth piston braking and avoid instantaneous pressure increases.

[0022] Specifically, the anti-air striking axis and the dead space are clearance-matched; the clearance between the anti-air striking axis and the dead space is 0.02mm to 0.1mm.

[0023] A pressure-equalizing groove is provided between adjacent rings; the outer diameter of the groove is smaller than that of the ring. The inter-axle pressure-equalizing groove effectively reduces the hydraulic clamping force caused by uneven oil distribution and piston eccentricity.

[0024] In some embodiments of the present application, the inner wall surface of the cylinder liner is provided with a front cavity, a rear cavity, a first signal oil port, a first high-pressure oil port, a first return oil port, a second signal oil port, a second return oil port, and a second high-pressure oil port from front to back.

[0025] The front chamber is connected to the oil inlet branch, the rear chamber is connected to the oil return branch, the first and second signal oil ports are connected via an oil passage provided on the cylinder liner, the first and second high-pressure oil ports are connected to the oil inlet branch, and the first and second oil return ports are connected to the oil return branch. The oil inlet branch is connected to a constant high-pressure oil supply, and the oil return branch is connected to a constant low-pressure oil supply, with the return oil pressure being approximately zero.

[0026] The above embodiments can be combined arbitrarily based on the common knowledge in this field.

[0027] A rock drill includes an adjustable impact device. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present application will be further described in detail below with reference to the accompanying drawings and preferred embodiments. However, those skilled in the art will appreciate that these drawings are drawn only for the purpose of explaining the preferred embodiments and therefore should not be construed as limiting the scope of the present application. In addition, unless otherwise specified, the drawings are merely schematic representations of the composition or structure of the described objects and may contain exaggerated representations. The drawings are not necessarily drawn to scale.

[0029] Figure 1 It is a schematic diagram of the structure of an adjustable impact device using a medium frequency rear stop sleeve;

[0030] Figure 2a This is a schematic diagram of the structure of the intermediate frequency rear stop sleeve;

[0031] Figure 2b It is a structural diagram of the intermediate frequency tail section;

[0032] Figure 3 Schematic diagram of the structure of an adjustable impact device using a low-frequency rear stop sleeve;

[0033] Figure 4a It is a structural diagram of the low-frequency rear stop sleeve;

[0034] Figure 4b It is a structural diagram of the low-frequency tail section;

[0035] Figure 5 It is a schematic diagram of the structure of an adjustable impact device using a high-frequency rear stop sleeve;

[0036] Figure 6a This is a structural diagram of the high-frequency rear stop sleeve;

[0037] Figure 6b This is a structural diagram of the high-frequency tail section.

[0038] Figure 7 This is a schematic structural diagram of the adjustable impact device of the present application;

[0039] Figure 8 for Figure 7 A partial enlarged view of point A in the middle;

[0040] Figure 9 This is a schematic diagram of the structure of the piston in this application;

[0041] Figure 10 For this application, the local amplification of the adjustable impact device Figure 1 ;

[0042] Figure 11 A second partial enlarged view of the adjustable impact device of this application;

[0043] Figure 12 It is a structural diagram of the reversing valve.

[0044] The specific descriptions of the reference numerals are as follows:

[0045] 2. Cylinder liner; 3. Reversing valve; 4. Piston; 401. Head section; 402. Tail section; 4a. Anti-aircraft shafting chamber; 4b. Retraction section; 7. Oil inlet branch; 8. Oil return branch; 9. Drilling tool; 9a. Mounting section;

[0046] 11. Oil circuit; 12. Conducting groove; 13. First signal channel; 14. Second signal channel;

[0047] 21. Front chamber; 22. Rear chamber; 23. First signal oil port; 24. First high-pressure oil port; 25. First oil return port; 26. Second signal oil port; 27. Second oil return port; 28. Second high-pressure oil port;

[0048] 31. Front stop sleeve; 32. Rear stop sleeve; 33. Stop groove; 34. Limiting cavity; 35. Ring; 36. Dead space; 37. Pressure equalizing groove;

[0049] 41. First-stage oil distribution sleeve; 42. Oil distribution ring; 43. Second-stage oil distribution sleeve; 44. Push valve stem; 45. Limit groove; 46. Limit cavity; 47. First channel; 48. Second channel; 49. Third channel; 50. Fourth channel. DETAILED DESCRIPTION

[0050] The present application will be described in detail below with reference to the accompanying drawings.

[0051] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0052] An impact device for a rock drill, such as Figures 1 to 12As shown: it includes a front stop sleeve 31, a cylinder sleeve 2 and at least two rear stop sleeves 32, the front stop sleeve 31 and any one of the rear stop sleeves 32 are coaxially connected to the cylinder sleeve 2 in sequence, the rear end of the drill tool 9 is located in the cavity formed by the front stop sleeve 31 and the rear stop sleeve 32, the piston 4 is coaxially arranged with the drill tool 9, the piston 4 is installed in the cylinder sleeve 2, the piston 4 is coaxially arranged with the drill tool 9, and the piston 4 reciprocates in the cylinder sleeve 2 to drive the drill tool (9) to impact the rock wall. A stop groove 33 adapted to the drill tool 9 is provided in the rear stop sleeve 32, the bottom surface of the stop groove 33 limits the limit position of the drill tool 9 moving backward, and the depth of each stop groove 33 provided on the rear stop sleeve 32 in the axial direction of the rear stop sleeve is different. The bottom surface of the stop groove 33 limits the limit position of the drill tool 9 moving backward, and the limit position of the drill tool 9 at the rear end will affect the impact point of the piston 4 during the entire working process. Adjusting the position of the piston 4's impact point affects the distance it travels, and thus the frequency with which it impacts the drill tool 9. The distance the piston 4 travels in the oil directly affects the kinetic energy stored in the piston 4. Adjusting the rear stop sleeve 32 adjusts the device's frequency and impact energy. This application designs the rear stop sleeve 32 as a standardized kit. Simply replacing the rear stop sleeve 32 and the active piston 4 facilitates power adjustment.

[0053] The applicability of this application is wider, and the standard mid-frequency rear stop sleeve 32 (the depth of the stop groove 33 is moderate, such as Figure 1 ), suitable for most working conditions; for soft rock formations, choose high-frequency rear stop sleeve 32 (the stop groove 33 is deeper, such as Figure 5 ); For hard rock formations, select low-frequency rear stop sleeve 32 (stop groove 33 is shallow, such as Figure 3 ). Rationally selecting the gear kit can effectively improve work efficiency.

[0054] The outer dimensions of each rear stop sleeve 32 are completely consistent. The present application designs the rear stop sleeve 32 as a standardized kit to avoid its outer dimensions from affecting the structural function of the present application.

[0055] The drilling tool 9 includes a mounting portion, which is located at the rear end of the entire drilling tool 9 and has a diameter greater than the diameter of other parts of the drilling tool 9. The front stop sleeve 31 and the rear stop sleeve 32 are connected to form a limiting cavity 34 for accommodating the mounting portion, and the limiting cavity 34 limits the travel of the drilling tool 9.

[0056] Specifically, the stop groove 33 constitutes the limit cavity 34. The limit cavity 34 on different rear stop sleeves 32 has different axial depths. The depth of the stop groove 33 determines the length of the entire limit cavity 34, that is, the stroke length of the drill tool 9.

[0057] The rear end face of the mounting portion is a truncated cone structure, and the rear end face of the mounting portion includes a plane and an inclined surface surrounding the outer ring of the plane. The plane of the rear end face of the mounting portion serves as the impact surface that contacts the piston 4, and the bottom surface of the retaining groove 33 is adapted to the inclined surface of the rear end face of the mounting portion. In the present application, the design of the inclined surface also plays a certain guiding role, ensuring that the drilling tool 9 is coaxial with the piston 4 when the drilling tool 9 moves backward to the limit position.

[0058] Example 2 Figures 7 to 12 As shown, the surface of the piston 4 is provided with an anti-aircraft space 4a, and the anti-aircraft space 4a includes a plurality of coaxially arranged rings 35, and there is a distance between two adjacent rings 35; the nominal diameter value of the ring 35 is equal to the diameter of the dead space 36 of the cylinder liner 2.

[0059] The piston 4 is provided with an anti-air drilling space 4a and cooperates with the dead space 36 of the cylinder liner 2. Before the air drilling tool 9 hits the front stop sleeve, the piston 4 enters the dead space 36 to consume energy in advance, thereby reducing damage to components.

[0060] The outer diameter of the rings 35 increases from the proximal to the distal end of the drilling tool 9; the diameter of the ring 35 farthest from the drilling tool 9 is equal to the diameter of the cylinder dead space 36. Preferably, the anti-aircraft axle gap 4a of the present application includes at least three coaxially arranged rings 35. The anti-aircraft axle gap 4a divides the entire braking process into at least three stages, with the gap gradually decreasing, effectively ensuring smooth braking of the piston 4 and preventing sudden pressure increases.

[0061] Specifically, the anti-air striking shaft space 4a and the dead space 36 are clearance-matched; the clearance between the anti-air striking shaft space 4a and the dead space 36 is 0.02mm to 0.1mm.

[0062] A pressure equalizing groove 37 is provided between two adjacent rings 35; the outer diameter of the pressure equalizing groove 37 is smaller than the outer diameter of the ring 35. At the same time, the pressure equalizing groove 37 between the shafts can effectively reduce the hydraulic clamping force generated by the eccentricity of the piston 4 due to uneven oil distribution between the shafts.

[0063] The rest of the content of the second embodiment is the same as that of the first embodiment.

[0064] Example 3 Figures 1 to 6b As shown, the inner wall surface of the cylinder liner 2 is provided with a front cavity 21, a rear cavity 22, a first signal oil port 23, a first high-pressure oil port 24, a first return oil port 25, a second signal oil port 26, a second return oil port 27, and a second high-pressure oil port 28 in sequence from front to back.

[0065] The front chamber 21 is connected to the oil inlet branch, the rear chamber 22 is connected to the oil return branch 8, the first signal oil port 23 and the second signal oil port 26 are connected via an oil passage provided on the cylinder liner 2, the first high-pressure oil port 24 and the second high-pressure oil port 28 are connected to the oil inlet branch, and the first oil return port 25 and the second oil return port 27 are connected to the oil return branch 8. The oil inlet branch is connected to a constant high-pressure oil, and the oil return branch 8 is connected to a constant low-pressure oil, and the return oil pressure is approximately equal to 0.

[0066] The rear end of the piston 4 is provided with a first signal channel 13 and a second signal channel 14, respectively, connecting the outer circumference of the piston 4 with its rear end. During normal operation of the piston 4, the first signal oil port 23 occasionally communicates with the first signal channel 13. The first signal channel 13 provides a signal indicating the normal operation of the piston 4. When the piston 4 is in a dry state (abnormal operation), the second signal oil port 26 occasionally communicates with the first signal channel 13.

[0067] In this application, to facilitate the use of the rear stop sleeve, the piston 4 is not a fixed, integral structure. Instead, the section containing the first signal channel 13 is segmented from the rest of the piston, allowing for easy replacement of parts of the piston structure with the rear stop sleeve 32. Specifically, the piston 4 includes a independently configured head section 401 and tail section 402, with the first and second signal channels 13 and 14 disposed on the tail section 402.

[0068] The present application includes at least two tail sections 402 , and the lengths of the first signal channels 13 on different tail sections 402 are different. The tail sections 402 correspond to the rear stop sleeves 32 on a one-to-one basis.

[0069] In this application, if Figure 2a 、 2b As shown, if the distance for the piston 4 to be inserted into the intermediate frequency rear stop sleeve 32 is X, the length of the first signal channel 13, that is, the distance from the outer peripheral surface of the piston 4 connected to the rear end face of the piston 4 to the rear end face of the piston 4, is Y. Then, if Figure 6a As shown, the distance for the piston 4 to be inserted into the high-frequency rear stop sleeve 32 is XN. Figure 6b As shown, the length of the first signal channel 13 is Y+N; Figure 4a As shown, the distance for the piston 4 to be inserted into the low-frequency rear stop sleeve 32 is X+M. Figure 4b As shown, the length of the first signal channel 13 is YM. Because the depth of the retaining groove 33 of the rear retaining sleeve 32 affects the travel distance of the piston 4, the length of the first signal channel 13 (the distance from the rear end face of the piston 4) must be changed accordingly to ensure that the first signal channel 13 provides feedback to the first signal oil port 23 to ensure normal operation.

[0070] The following are the general parameters of the rear stop sleeve 32 and the tail section 402 for the rock drill selection: In the intermediate frequency gear, X and Y are obtained according to the standard design of the rock drill. To ensure adjustability, X is generally 4-10mm and Y is generally selected to be 30-40mm. N and M are both positive values. N is generally selected from 1-4mm and M is generally selected from 0-10mm. N and M do not have to be equal. Specifically, after adjusting N, it is necessary to ensure that the impact point of the assumed piston in this stroke is close to the maximum speed position of the piston 4. Accordingly, the position of the first signal oil port 23 is adjusted to ensure that the above-mentioned impact point is close to the maximum speed position of the piston 4. Generally, N is approximately equal to 0.5-3 times M.

[0071] The rest of the content of the third embodiment is the same as that of the first or second embodiment.

[0072] Example 4, as Figures 1 to 12 As shown, it includes a cylinder liner 2, a reversing valve 3 and a piston 4, wherein the piston 4 and the reversing valve 3 are coaxially arranged in the cylinder liner 2. The reversing valve 3 and the piston 4 are coaxially arranged and installed, and both the reversing valve 3 and the piston 4 can move axially in the cylinder liner 2.

[0073] The cylinder liner 2 is provided with an oil inlet branch 7 and an oil return branch 8. Oil passes through the cylinder liner 2 and contacts the piston 4 and the reversing valve 3. The reversing valve 3 moves within the cylinder liner 2, changing the oil flow, thereby switching the thrust on the rear end of the piston 4 and assisting the entire movement of the piston 4.

[0074] In this application, the side of the piston 4 close to the drilling tool 9 is the front, and correspondingly, the side of the piston 4 away from the drilling tool 9 is the rear. The front end of the piston 4 is connected to the drilling tool 9, and the rear end of the piston 4 is occasionally in contact with the reversing valve 3.

[0075] The reversing valve 3 is provided with an oil circuit 11, which connects the front end face and the rear end face of the reversing valve 3. Furthermore, the front end of the reversing valve 3 has a contact surface, which contacts the piston 4. A conducting groove 12 is provided on the contact surface, which connects the oil circuit 11 and the periphery of the reversing valve 3. When the reversing valve 3 is in contact with the piston 4, although the structure does not intentionally have a corresponding sealing structure, it may still be the case that the oil cannot flow between the contact surfaces of the reversing valve 3 during operation. Therefore, the present application additionally provides a conducting groove 12 to ensure that the oil can flow smoothly through the conducting groove 12 during operation, that is, the oil on the periphery of the reversing valve 3 and the oil circuit 11 are in a mutually conductive state.

[0076] The inner wall surface of the cylinder liner 2 is provided with a front cavity 21, a rear cavity 22, a first signal oil port 23, a first high-pressure oil port 24, a first oil return port 25, a second signal oil port 26, a second oil return port 27, and a second high-pressure oil port 28 in sequence from front to back.

[0077] The front chamber 21 is connected to the oil inlet branch 7, the rear chamber 22 is connected to the oil return branch 8, the first signal oil port 23 and the second signal oil port 26 are connected via an oil passage provided on the cylinder liner 2, the first high-pressure oil port 24 and the second high-pressure oil port 28 are connected to the oil inlet branch 7, and the first oil return port 25 and the second oil return port 27 are connected to the oil return branch 8. The oil inlet branch is connected to a constant high-pressure oil, and the oil return branch is connected to a constant low-pressure oil, and the return oil pressure is approximately equal to 0.

[0078] The piston 4 is provided with an anti-aircraft shaft space 4a corresponding to the front cavity 21. The diameter of the anti-aircraft shaft space 4a is the largest diameter of the piston 4, and the anti-aircraft shaft space 4a is located in the front cavity 21. During the entire movement process of the normal operation of the piston 4, it is limited by the front cavity 21 and is always in the front cavity 21.

[0079] The piston 4 is provided with a contraction section 4b corresponding to the rear cavity 22. The diameter of the contraction section 4b is smaller than the diameter of the piston 4 adjacent to the contraction section 4b. During the entire movement process of normal operation of the piston 4, the diameter of the contraction section 4b is smaller, and the contraction section 4b is not restricted by the rear cavity 22, and can move outside the range of the rear cavity 22.

[0080] Specifically, in an oil-filled environment, the area of ​​the oil acting on the rear end surface of the piston 4 is larger than the area of ​​the contraction section 4b in the rear cavity 22, and the area of ​​the oil acting on the contraction section 4b in the rear cavity 22 is larger than the area of ​​the anti-aircraft shaft space 4a in the front cavity 21.

[0081] Since the effective area of ​​the switching oil pressure end face (rear end face) is large, the oil pressure required to achieve the same effective thrust is lower and the flow rate is larger. The lower effective oil pressure can reduce the damage to components caused by high-pressure impact to a certain extent and reduce the consumption of components.

[0082] The rear end of the piston 4 is provided with a first signal channel 13 and a second signal channel 14, respectively, connecting the outer circumference of the piston 4 with its rear end. During normal operation of the piston 4, the first signal oil port 23 occasionally communicates with the first signal channel 13. The first signal channel 13 provides a signal indicating the normal operation of the piston 4. When the piston 4 is in a runaway state (abnormal operation), the second signal oil port 26 occasionally communicates with the first signal channel 13.

[0083] The rear end surface of the piston 4 is communicated with the oil path 11 of the reversing valve 3 , and the second signal channel 14 is communicated with the rear end of the reversing valve 3 .

[0084] The reversing valve 3 and the piston 4 are coaxially arranged and installed. The front and rear chambers 22 of the reversing valve 3 alternately change oil to achieve the movement of the reversing valve 3. The coaxial arrangement of the piston 4 and the reversing valve 3 is simple and compact, making disassembly and maintenance easier. In terms of external dimensions, the center height of this application is lower.

[0085] In the present application, there are fewer alternating oil chambers, and the contact area of ​​such alternating oil chambers is large. In addition, due to the low pressure and high flow characteristics of such rock drills, the end face oil pressure is more stable, the mutation is smaller, and the switching movement is more stable, which reduces the possibility of negative pressure on this end face. Combined with the action of the throttle valve, the probability of negative pressure in the chamber is reduced, which reduces the possibility of cavitation in the rock drill cavity to a certain extent.

[0086] This application also includes a push-valve assembly. Within the cylinder liner 2, from front to back, are a piston 4, a reversing valve 3, and a push-valve assembly. The reversing valve 3 is cylindrical, and its rear end is provided with a notch for accommodating the push-valve assembly. During the entire movement of the piston 4, portions of the push-valve assembly occasionally become embedded in the notch.

[0087] The push valve assembly includes a primary oil distribution sleeve 41, a secondary oil distribution sleeve 43 and a push valve rod 44. The primary oil distribution sleeve 41 is sleeved outside the secondary oil distribution sleeve 43, and the secondary oil distribution sleeve 43 is sleeved outside the push valve rod 44.

[0088] A limit groove 45 is provided in the cylinder liner 2. Together with the rear end surface of the cylinder liner 2's inner cavity, the limit groove 45 and the rear end surface of the cylinder liner 2's inner cavity constitute a travel limit for the primary oil distribution sleeve 41. Throughout the normal movement of the piston 4, the primary oil distribution sleeve 41 at least partially moves between the limit groove 45 and the rear end surface of the cylinder liner 2's inner cavity.

[0089] The rear end surface of the primary oil distribution sleeve 41 and the rear end surface of the inner cavity of the cylinder liner 2 constitute the travel limit of the secondary oil distribution sleeve 43. During the entire movement process of normal operation of the piston 4, the primary oil distribution sleeve 41 at least partially moves between the rear end surface of the primary oil distribution sleeve 41 and the rear end surface of the inner cavity of the cylinder liner 2.

[0090] Furthermore, an oil distribution ring 42 is installed at the rear end surface of the first oil distribution sleeve 41. The rear end surface of the oil distribution ring 42 and the rear end surface of the inner cavity of the cylinder liner 2 constitute the travel limit of the second oil distribution sleeve 43.

[0091] A limit cavity 46 is provided within the secondary oil distribution sleeve 43. This limit cavity 46 and the rear end surface of the cylinder liner 2 inner cavity constitute a travel limit for the valve push rod 44. Throughout the normal operation of the piston 4, the valve push rod 44 at least partially moves between the limit cavity 46 and the rear end surface of the cylinder liner 2 inner cavity.

[0092] During the entire movement process of the piston 4 in normal operation, the movement stroke of the valve push rod 44 is greater than the movement stroke of the secondary oil distribution sleeve 43 , and the movement stroke of the secondary oil distribution sleeve 43 is greater than the movement stroke of the primary oil distribution sleeve 41 .

[0093] The second high-pressure oil port 28 is communicated with the rear end surface of the first-stage oil distribution sleeve 41 , the second-stage oil distribution sleeve 43 , and the push valve stem 44 . The second high-pressure oil port 28 is communicated with the rear end surface of the oil distribution ring 42 .

[0094] The first oil distribution sleeve 41 is provided with a first passage 47 for oil flow. The first passage 47 connects the inner wall and outer circumference of the first oil distribution sleeve 41, leaving a gap between the first oil distribution sleeve 41 and the second oil distribution sleeve 43. The second oil distribution sleeve 43 is provided with a second passage 48 for oil flow. The second passage 48 connects the inner wall and outer circumference of the second oil distribution sleeve 43, leaving a gap between the second oil distribution sleeves 43. The first and second passages 47, 48 are connected to the second oil return port 27.

[0095] The secondary oil distribution sleeve 43 is provided with a third channel 49, which connects the front end surface of the secondary oil distribution sleeve 43 with the outer peripheral surface of the secondary oil distribution sleeve 43. The secondary oil distribution sleeve 43 is provided with a fourth channel 50 for oil to pass through; during the entire movement process of the normal operation of the piston 4, the fourth channel 50 is occasionally connected to the third channel 49.

[0096] In this application, the reversing valve 3 performs graded braking, and the reversing braking process is smoother and more efficient.

[0097] The push valve assembly has graded braking, and the reversing is smoother. Different reversing braking efficiencies can be achieved through the effective areas of each level of the push valve assembly. It has a wide range of applications, and is especially suitable for the reversing mechanism of high-power equipment.

[0098] The rest of the content of the fourth embodiment is the same as that of the third embodiment.

[0099] The motion process of this application is as follows:

[0100] Stroke motion:

[0101] The kinematic pair (piston 4, reversing valve 3, push rod, secondary oil distribution sleeve 43, primary oil distribution sleeve 41, primary oil distribution ring 42) is subjected to the high-pressure force at the second high-pressure oil port 28 and the high-pressure force at the front chamber 21. The combined force moves forward, and the kinematic pair accelerates forward until the primary oil distribution sleeve 41 reaches the left stroke limit. The primary oil distribution sleeve 41 and the primary oil distribution ring 42 stop moving, and the previous high-pressure oil action area is reduced. The kinematic pair (piston 4, reversing valve 3, push rod, secondary oil distribution sleeve 43) continues to accelerate forward, but the acceleration decreases.

[0102] The kinematic pair (piston 4, reversing valve 3, push rod, and secondary oil distribution sleeve 43) is still subject to the high-pressure force from the second high-pressure oil port 28 and the high-pressure force from the front chamber 21. The combined forces push the kinematic pair forward until the secondary oil distribution sleeve 43 reaches the mechanical limit. At this point, the high-pressure oil from the first high-pressure oil port 24 flows from the front end of the reversing valve 3 through the guide groove 12 into the rear end face of the piston 4, causing the piston 4 to separate from the reversing valve 3. Because the effective area of ​​the rear end face of the piston 4 is much larger than the effective area of ​​the front chamber 21, the piston 4 accelerates forward. The effective area of ​​the front end face of the reversing valve 3 is larger than the effective area of ​​the rear end of the push rod 44, and smaller than the effective area of ​​the combined rear end faces of the primary oil distribution sleeve 41 and the secondary oil distribution sleeve 43. Therefore, the reversing valve 3 is pressed and stationary in this position.

[0103] The piston 4 accelerates forward and is connected to the oil port of the first signal channel 13. The high-pressure oil enters the rear end of the reversing valve 3 through the first signal channel 13 and the oil circuit 11. The effective area of ​​the high-pressure oil on the rear side of the reversing valve 3 (the sum of the effective area of ​​the rear end of the reversing valve 3 and the effective area of ​​the rear end face of the push valve stem 44) is larger than the effective area of ​​the front end face of the reversing valve 3. The area difference is the area difference between the rear end face and the front end face of the push valve stem 44. Therefore, the main force of the reversing valve 3 is converted into the rear side thrust, and the combined force is forward, and the reversing valve 3 starts to accelerate forward.

[0104] The piston 4 and the reversing valve 3 move forward at different accelerations and speeds until the reversing valve 3 closes the first high-pressure oil port 24. The rear end face of the piston 4 and the front and rear chambers 22 of the reversing valve 3 lose the effect of high-pressure oil. At the same time, the piston 4 collides with the drill tool 9, transferring the impact energy to the drill tool 9, and preparing to start a new cycle of backward return motion; the main force of the reversing valve 3 is converted into the force exerted on the valve stem 44, and the combined force continues to move forward until it contacts the rear end face of the piston 4 and waits for the next return stage.

[0105] Return Movement:

[0106] The push valve stem 44 is acted upon by constant high-pressure oil, and the resultant force is forward, and the reversing valve 3 is pressed to the front end of the stroke; the rear end face of the piston 4 is connected to the first oil return port 25, and the first high-pressure oil port 24 is closed; the front chamber 21 of the piston 4 takes in high-pressure oil, and the rear chamber 22 returns low-pressure oil, and the rear end face is connected to the return oil port of the rear end face of the reversing valve 3; since the effective area of ​​the rear end of the push valve stem 44 is smaller than the effective area of ​​the high-pressure oil in the front chamber 21 of the piston 4, the main force is the force of the front chamber 21, and the resultant force is backward, and the piston 4 drives the main oil distribution valve and the push valve stem 44 to accelerate backward.

[0107] The piston 4 moves backward to accelerate until the first signal oil port 23 is connected to the first oil return port 25 at the rear end of the piston 4, and then the return oil relies on the first oil return port 25 at the rear end of the reversing valve 3 and the first signal oil port 23 to return the oil together; the main force is still the force of the piston 4 at the front chamber 21, and the combined force is backward, so the piston 4 continues to drive the reversing valve 3 and the valve stem 44 to move backward to accelerate.

[0108] The piston 4 moves backward and accelerates until the first oil return port 25 of the rear chamber 22 of the reversing valve 3 is closed. The oil return of the piston 4 relies only on the single-channel oil return of the second signal oil port 26; the main force is still the force of the front chamber 21, and the combined force is backward. The piston 4 continues to drive the reversing valve 3 and the valve stem 44 to move backward and accelerate.

[0109] The piston 4 moves backward with acceleration until the reversing valve 3 contacts the secondary oil distribution sleeve 43 and pushes the secondary oil distribution sleeve 43 to move backward. At this time, since the rear end of the secondary oil distribution sleeve 43 is acted upon by the high-pressure oil at the second high-pressure groove, the forward resultant force on the reversing valve 3 is further increased, and its effective area is larger than the effective area of ​​the high-pressure oil of the piston 4 at the front chamber 21. Therefore, the kinematic pair (piston 4, reversing valve 3, push rod, and secondary oil distribution sleeve 43) moves backward with deceleration.

[0110] The piston 4 moves backward to perform a decelerating motion until the reversing valve 3 contacts the primary oil distribution sleeve 41 and pushes the secondary oil distribution sleeve 43 to move backward. At this time, since the rear ends of the secondary oil distribution sleeve 43 and the rear ends of the primary oil distribution sleeve 41 are both affected by high-pressure oil, the forward resultant force on the reversing valve 3 is further increased, and its effective area is larger than the effective area of ​​high-pressure oil in the front chamber 21 of the piston 4. Therefore, the kinematic pair (piston 4, reversing valve 3, push rod, secondary oil distribution sleeve 43, primary oil distribution sleeve 41, primary oil distribution ring 42) performs a decelerating motion backward together, and the deceleration effect is stronger.

[0111] The piston 4 moves backward with deceleration until the valve stem 44 reaches the rear travel limit. At this time, the speed of the kinematic pair (piston 4, reversing valve 3, push rod, secondary oil distribution sleeve 43, primary oil distribution sleeve 41, primary oil distribution ring 42) is close to 0. The return process is completed, completing one cycle of motion, and then continuing to the next cycle.

[0112] A rock drill comprises the adjustable impact device according to any one of the above embodiments.

[0113] The present application has been described in detail above. Specific examples have been used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is intended only to facilitate understanding of the present application and its core concepts. It should be noted that, without departing from the principles of the present application, a number of improvements and modifications may be made to the present application by a person skilled in the art, and such improvements and modifications shall fall within the scope of protection of the claims of the present application.

Claims

1. An impact device for a rock drill, characterized in that The invention comprises a front stop sleeve (31), a cylinder sleeve (2) and at least two rear stop sleeves (32), wherein the front stop sleeve (31) and any one of the rear stop sleeves (32) are coaxially connected to the cylinder sleeve (2) in sequence, and a stop groove (33) adapted to the drill tool (9) is provided in the rear stop sleeve (32), and the rear end of the drill tool (9) is located in the cavity formed by the front stop sleeve (31) and the rear stop sleeve (32), and the bottom surface of the stop groove (33) limits the extreme position of the rearward movement of the drill tool (9), and the depth of each stop groove (33) provided on the rear stop sleeve (32) in the axial direction of the rear stop sleeve (32) is different; The invention comprises a head section (401) and at least two tail sections (402), wherein the head section (401) is connected to any one of the tail sections (402) to form a piston (4) installed in a cylinder sleeve (2), and a first signal channel (13) is provided on the tail section (402), and the first signal channel (13) connects the outer peripheral surface of the piston (4) with the rear end surface of the piston (4); the lengths of the first signal channels (13) on different tail sections (402) are different, and the tail sections (402) correspond to the rear stop sleeves (32) one by one; The drilling tool (9) includes a mounting portion (9a), the mounting portion (9a) is located at the rear end of the entire drilling tool (9), and the diameter of the mounting portion (9a) is larger than the diameter of other parts of the drilling tool (9); The front stop sleeve (31) and the rear stop sleeve (32) are connected to form a limiting cavity (34) for accommodating the mounting portion (9a), and the limiting cavity (34) limits the movement stroke of the drill tool (9); the stopping groove (33) constitutes the limiting cavity (34), and the limiting cavities (34) on different rear stop sleeves (32) have different depths in their axial direction; The surface of the head section (401) is provided with an anti-aircraft shaft space (4a), and the anti-aircraft shaft space (4a) includes a plurality of coaxially arranged rings (35), and there is a distance between two adjacent rings (35); the nominal diameter value of the rings (35) is equal to the diameter of the dead space (36) of the cylinder liner (2).

2. The impact device of a rock drill according to claim 1, characterized in that The rear end face of the mounting portion (9a) is a truncated cone structure, and the rear end face of the mounting portion (9a) includes a plane and an inclined surface surrounding the outer ring of the plane; the plane of the rear end face of the mounting portion (9a) is an impact surface in contact with the piston (4), and the bottom surface of the retaining groove (33) is adapted to the inclined surface of the rear end face of the mounting portion (9a).

3. The impact device of a rock drill according to claim 1, characterized in that: The piston (4) and the drilling tool (9) are coaxially arranged, and the piston (4) performs reciprocating motion in the cylinder sleeve (2) to drive the drilling tool (9) to impact the rock wall.

4. The impact device of a rock drill according to claim 3, characterized in that: The tail section (402) is also provided with a second signal channel (14), and the second signal channel (14) connects the outer peripheral surface of the piston (4) with the rear end surface of the piston (4).

5. The impact device of a rock drill according to claim 4, characterized in that: During the normal working process of the piston (4), the first signal oil port (23) is occasionally communicated with the first signal channel (13); the first signal channel (13) is a signal indicating the normal working of the piston (4); and in the idle striking state of the piston (4), the second signal oil port (26) is occasionally communicated with the first signal channel (13).

6. The impact device of a rock drill according to claim 1, characterized in that The anti-air striking space (4a) comprises at least three coaxially arranged rings (35); the outer diameters of the rings (35) increase in sequence from the proximal drilling tool (9) to the distal drilling tool (9); and the diameter of the ring (35) farthest from the drilling tool (9) is equal to the diameter of the dead space (36) of the cylinder liner.

7. A rock drill, characterized in that The invention comprises an impact device of a rock drill according to any one of claims 1 to 6.

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