Rebound energy absorbing device and rock drill

Abstract

The present application discloses a kind of rebound kinetic energy buffer device and rock drill, including drill tail, shell assembly, the impact piston of being passed in shell assembly, rebound kinetic energy buffer device includes: buffer piston, is set in impact piston, the outer wall of buffer piston is provided with buffer structure, the inner wall of shell assembly is opened with buffer structure and is used for the buffer cavity of cooperation, buffer structure is first buffer face towards the end of drill tail, the end of second buffer face away from drill tail of buffer structure;First chamber, between first buffer face and the inner wall of buffer cavity;Second chamber, between second buffer face and the inner wall of buffer cavity;Third chamber, between the end of buffer piston away from drill tail and the inner wall of shell assembly;First oil way, for low-pressure oil source is connected to first chamber;Second oil way, for high-pressure oil source is connected to second chamber;Third oil way, for when buffer piston moves to first preset range of stroke, second chamber and first chamber are connected.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of rock drills, in particular, to a rebound kinetic energy buffer device and a rock drill. BACKGROUND

[0002] The hydraulic impact hole-forming device based on the comprehensive rock breaking principle of torsional cutting under the impact rotation is the component with the highest drilling efficiency for short hole drilling. In order to realize the efficient transmission of the energy generated by the impact hole-forming device to the inside of the rock in the form of stress waves and achieve the goal of rapid rock breaking and drilling, a buffer mechanism is needed to tightly and tightly press the drill against the rock mass. After a certain scale of footage is generated by the impact of the impact hole-forming device once, the impact hole-forming device needs to be quickly pushed forward to press the rock. Although the impact hole-forming device has a push cylinder to push it to the excavated rock wall, it is difficult to meet the requirement of quickly pressing the rock under high-frequency impact due to the large mass of the moving parts. Therefore, the prior art designs a corresponding impact hole-forming device buffer mechanism. After a certain scale of footage is generated by the impact of the impact hole-forming device once, the buffer hydraulic mechanism can push the drill to quickly press against the rock wall under the action of hydraulic pressure, thereby realizing efficient rock breaking.

[0003] When the stress wave generated by the impact hole-forming device is transmitted from the impact piston end face to the drill bit and rock interface, under the condition of rock debris, cavities or insufficient thrust, a considerable part of the energy will be transmitted to the impact piston side in the opposite direction when the stress wave is transmitted to the drill bit end, causing the drill tail to rebound. If the rebound kinetic energy of the drill tail is not buffered, the rebound kinetic energy will be directly transmitted to the impact shell or other parts, thereby converting the kinetic energy into internal energy, causing the temperature of other parts to rise or break. Therefore, how to effectively buffer the rebound energy of the drill is the key to the reliability design of the impact hole-forming device. The buffer mechanism of the impact hole-forming device in the prior art mainly adopts pressure holding braking. Due to the water hammer effect, a large pressure peak will be generated at the moment of pressure holding braking. When the pressure peak acts on a large area of the buffer mechanism, it will bear a large impact load, reducing the service life and reliability of the parts.

[0004] For example, patent number: CN111712353A discloses a rotary impact hydraulic hole drill comprising a body, including a fitting, a striking piston configured to strike the fitting, an impact piston having a front face facing the fitting and a rear wall facing the cavity accommodating the impact piston; and a main hydraulic supply circuit including a high-pressure fluid supply line and a low-pressure fluid return line. The body and the impact piston define a first control chamber permanently connected to the high-pressure fluid supply line and configured to push the impact piston forward, and a second control chamber configured to push the impact piston forward and permanently connected to a low-pressure accumulator connected to the low-pressure fluid return line. The design of the buffer mechanism in the above technical solution obviously has the problems of large piston ring cross-sectional size, large energy loss of high-pressure oil throttling, and serious system heating, resulting in the problems of short service life and low reliability as described above.

[0005] For example, patent number CN104755230A discloses a buffer device for an impact device, an impact device, a rock drill, and a method for buffering in the rock drill. It regulates the flow rate through a buffer flow regulator installed on the buffer oil circuit, and a control signal is sent to the buffer flow regulator via a control device to regulate the buffer flow rate. Parameters related to the buffer oil are sensed by sensors, and the control device receives signals from the sensors and transmits control signals. The buffer regulator is controlled to maintain a constant or substantially constant buffer flow rate observed during the drilling phase, thereby achieving constant flow control during the buffering process. This method primarily relies on the coordinated control of sensors and a control system to achieve buffer regulation, which depends on circuit coordination, making it more complex and resulting in higher maintenance and repair difficulties and costs. Summary of the Invention

[0006] This invention provides a rebound kinetic energy buffer device and a rock drill to solve the technical problems of high impact, easy damage and short service life of the buffer structure of the hydraulic impact hole drill in the prior art.

[0007] The technical solution adopted in this invention is as follows:

[0008] A rebound kinetic energy buffer device is applied to a hydraulic impact drilling tool, the hydraulic impact drilling tool including a drill bit, a housing assembly, and an impact piston passing through the housing assembly, the rebound kinetic energy buffer device comprising:

[0009] A buffer piston is sleeved on the impact piston. The outer wall of the buffer piston is provided with a buffer structure. The inner wall of the outer shell assembly is provided with a buffer cavity for cooperating with the buffer structure. The end of the buffer structure facing the drill bit is a first buffer surface, and the end of the buffer structure away from the drill bit is a second buffer surface.

[0010] The first chamber is formed between the first buffer surface and the inner wall of the buffer chamber;

[0011] The second chamber is formed between the second buffer surface and the inner wall of the buffer chamber;

[0012] The third chamber is formed between the end of the buffer piston away from the tappet and the inner wall of the housing assembly;

[0013] The first oil passage is used to connect a low-pressure oil source to the first chamber;

[0014] The second oil circuit is used to connect the high-pressure oil source to the second chamber;

[0015] The third oil passage is used to connect the second chamber with the first chamber when the buffer piston moves to the first preset stroke range.

[0016] As a further improvement to the above technical solution, the rebound kinetic energy buffer device further includes a fourth oil circuit for connecting a low-pressure oil source to the third chamber, and the rebound kinetic energy buffer device further includes a fifth oil circuit for connecting a high-pressure oil source to the third chamber when the buffer piston moves to the second preset stroke range.

[0017] As a further improvement to the above technical solution, the fourth oil passage is connected to the first oil passage and is used to change the flow area between the fourth and first oil passages as the stroke of the buffer piston changes.

[0018] As a further improvement to the above technical solution, the first oil passage is opened in the outer shell assembly, and the inner wall of the outer shell assembly is provided with an annular groove communicating with the first oil passage. The fourth oil passage includes a first oil port located on the outer wall of the buffer piston and a second oil port located on the end face of the buffer piston away from the shank. The buffer piston is provided with an oil groove at the first oil port position. The oil groove is used to cooperate with the annular groove and to gradually reduce the cooperation area with the annular groove when the buffer piston moves from the extreme position toward the shank end to the extreme position away from the shank end.

[0019] As a further improvement to the above technical solution, the third oil passage is opened in the buffer piston. The third oil passage includes a third oil port and a fourth oil port. The third oil port is located on the outer wall of the buffer piston on the side of the first buffer surface, and the fourth oil port is located on the side wall of the buffer piston on the side of the second buffer surface. The fourth oil port is used to cooperate with the inner wall of the outer casing assembly to close the third oil passage when the buffer piston moves to a position outside the first preset stroke range.

[0020] As a further improvement to the above technical solution, the inner wall of the outer casing assembly is provided with a first sealing ring for movable sealing cooperation with the buffer piston; the inner wall of the buffer piston is provided with a second sealing ring for movable sealing cooperation with the impact piston.

[0021] As a further improvement to the above technical solution, the rebound kinetic energy buffer device also includes a sixth oil passage for connecting the low-pressure oil source to the inner wall of the buffer piston.

[0022] As a further improvement to the above technical solution, the rebound kinetic energy buffer device further includes a low-pressure accumulator and a high-pressure accumulator. The low-pressure accumulator is used to connect to a low-pressure oil source and to communicate with the first chamber via the first oil circuit. The high-pressure accumulator is used to connect to the high-pressure oil source and to communicate with the second chamber via the second oil circuit.

[0023] As a further improvement to the above technical solution, the rebound kinetic energy buffer device also includes a backstop sleeve, which is sleeved on the impact piston and disposed between the buffer piston and the drill bit.

[0024] According to another aspect of the present invention, a rock drill is also provided, which incorporates any of the above-described rebound kinetic energy buffer devices.

[0025] The present invention has the following beneficial effects:

[0026] When the buffer piston is in the equilibrium position, it extends towards the drill bit. During operation, the kinetic energy generated by the drill bit's rebound acts on the buffer piston, causing it to move away from the drill bit. The high-pressure oil in the second chamber acts on the second buffer surface to buffer the piston. The first preset stroke range includes the buffer piston's extreme position in the stroke direction and the stroke range approaching the extreme position. That is, after the buffer piston moves a certain distance away from the drill bit due to the kinetic energy of the drill bit's rebound, it leaves the first preset stroke range, thus closing the third oil circuit. At this time, the first chamber will lack oil filling, causing the oil pressure in the first chamber to drop to zero or negative pressure instantaneously. The second chamber will instantly generate a higher pressure, instantly increasing the braking force on the buffer piston, thus effectively buffering the piston. The third chamber is connected to the device's hydraulic oil supply control circuit, meaning that the third chamber is filled with hydraulic oil to buffer the buffer piston, causing it to return to its original position. During operation, the device is continuously buffered by the hydraulic oil in the third chamber, allowing it to complete the braking process through the combined action of the first, second, and third chambers. Based on this rebound kinetic energy buffer device, the buffer piston and buffer structure, along with the inner cavity and buffer chamber of the outer shell assembly, form three chambers. Each chamber and its oil circuit work in tandem, causing the buffering force on the buffer piston to change with its stroke, thus achieving smooth buffering. This effectively controls the maximum buffering pressure, reduces pressure pulses during buffering that could damage mechanical components, and significantly improves service life. Actual testing has verified that the service life of the buffer structure in existing hydraulic hole-forming devices is more than 10 times longer. The device as a whole uses a mechanical structure to control and adjust the buffering pressure according to the stroke of the buffer piston, avoiding reliance on sensor-based circuit systems, reducing device and maintenance costs, and improving overall device reliability.

[0027] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0028] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0029] Figure 1 This is a schematic cross-sectional view of the buffer piston in a balanced state according to a preferred embodiment of the present invention;

[0030] Figure 2 This is a schematic cross-sectional view of the buffer piston in the return limit position according to a preferred embodiment of the present invention;

[0031] Figure 3 This is a schematic diagram of the cross-sectional structure of the buffer piston according to a preferred embodiment of the present invention;

[0032] Figure 4 This is a schematic diagram of the buffer piston structure of a preferred embodiment of the present invention;

[0033] Figure 5 This is a schematic diagram of the buffer piston in a preferred embodiment of the present invention within a first preset stroke range;

[0034] Figure 6 This is a schematic diagram of the buffer piston disengaging from the first preset stroke range according to a preferred embodiment of the present invention;

[0035] Figure 7 This is a schematic diagram of the buffer piston in a preferred embodiment of the present invention within a second preset stroke range;

[0036] Figure 8 This is a schematic diagram of the buffer piston in a preferred embodiment of the present invention within a third preset stroke range;

[0037] 1. Outer shell assembly; 2. Chisel tail; 3. Anti-reverse sleeve; 4. Impact piston; 5. Buffer piston; 51. First end face; 52. Second end face; 53. First buffer surface; 54. Second buffer surface; 55. Third oil passage; 551. Third oil port; 552. Fourth oil port; 56. Fourth oil passage; 561. First oil port; 562. Second oil port; 563. Oil groove; 57. Fifth oil passage; 571. Fifth oil port; 572. Sixth oil port; 58. Sixth oil passage; 581. Seventh oil port; 6. Stop piston sleeve; 61. First oil passage; 611. Annular groove; 62. Second oil passage; 7. Cylinder block; 8. Low-pressure accumulator; 9. High-pressure accumulator; 10. First high-pressure oil source; 11. Low-pressure oil source; 12. Second high-pressure oil source; 13. First chamber; 14. Second chamber; 15. Third chamber; 16. First streamline; 17. Second streamline; 18. Third streamline. Detailed Implementation

[0038] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0039] Reference Figures 1 to 8A preferred embodiment of the present invention provides a rebound kinetic energy buffer device applied to a hydraulic impact drilling machine. The hydraulic impact drilling machine includes a drill bit 2, a housing assembly 1, and an impact piston 4 passing through the housing assembly 1. The rebound kinetic energy buffer device includes:

[0040] A buffer piston 5 is sleeved on the impact piston 4. The outer wall of the buffer piston 5 protrudes to form a buffer structure. The inner wall of the outer shell assembly 1 is provided with a buffer cavity for cooperating with the buffer structure. The end of the buffer structure facing the drill bit 2 is the first buffer surface 53, and the end of the buffer structure away from the drill bit 2 is the second buffer surface 54. The buffer piston 5 includes a first end surface 51 facing the drill bit 2 and a second end surface 52 away from the drill bit 2.

[0041] The first chamber 13 is formed between the first buffer surface 53 and the inner wall of the buffer chamber;

[0042] The second chamber 14 is formed between the second buffer surface 54 and the inner wall of the buffer chamber;

[0043] The third chamber 15 is formed between the end of the buffer piston 5 away from the rod tip 2 and the inner wall of the outer casing assembly 1, and is used to connect to the hydraulic oil supply control circuit of this device to buffer the buffer piston 5 that performs a return action under the influence of the rebound kinetic energy.

[0044] The first oil passage 61 is used to connect the low-pressure oil source 11 to the first chamber 13;

[0045] The second oil passage 62 is used to connect the high-pressure oil source to the second chamber 14;

[0046] The third oil passage 55 is used to connect the second chamber 14 with the first chamber 13 when the buffer piston 5 moves to the first preset stroke range.

[0047] The outer casing assembly 1 includes a cylinder body 7 and a stop piston sleeve 6 disposed within the cylinder body 7. The stop piston sleeve 6 engages with the inner wall of the cylinder body 7 and is fitted onto the outer wall of the buffer piston 5. A buffer cavity is formed on the inner wall of the end of the stop piston sleeve 6 facing the cylinder body 7. The length of the buffer cavity matches the stroke of the buffer piston 5 or is slightly greater than the stroke of the buffer piston 5, so that the first cavity and / or the second cavity still have oil accommodating space at the extreme position. The first oil passage 61 includes a first flow channel opened in the stop piston sleeve, and the second oil passage 62 includes a second flow channel opened in the cylinder body 7, or opened in the stop piston sleeve, or disposed between the cylinder body 7 and the stop piston sleeve.

[0048] The working principle of this rebound kinetic energy buffer device:

[0049] When the buffer piston 5 is in the equilibrium position, it is extended towards the drill bit 2. During operation, the kinetic energy generated by the rebound of the drill bit 2 acts on the buffer piston 5, causing it to move away from the drill bit 2. The high-pressure oil in the second chamber 14 acts on the second buffer surface 54 to buffer the buffer piston 5. The first preset stroke range includes the extreme position of the buffer piston 5 in the stroke direction and the stroke range approaching the extreme position in the stroke direction. That is, after the buffer piston 5 moves a certain distance away from the drill bit 2 due to the rebound kinetic energy, it leaves the first preset stroke range, thereby closing the third oil circuit 55. At this time, the first chamber 13 will lack oil filling, causing the oil pressure in the first chamber 13 to drop to zero or negative pressure instantaneously. The second chamber 14 will instantly generate a higher pressure, which instantaneously increases the braking force on the buffer piston 5, thus effectively buffering the buffer piston 5. The third chamber 15 is connected to the hydraulic oil supply control circuit of the device, that is, the third chamber 15 is filled with hydraulic oil to buffer the buffer piston 5. The device employs a buffering mechanism, whereby the buffer piston 5 is continuously buffered by the hydraulic oil in the third chamber 15 during its rebound stroke. This buffering is achieved through the coordinated action of the first chamber 13, the second chamber 14, and the third chamber 15, completing the braking process. Based on this rebound kinetic energy buffering device, the buffer structure of the buffer piston 5, in conjunction with the buffer chamber of the outer casing assembly 1, forms the first chamber 13 and the second chamber 14, enriching the buffering control methods. The coordinated action of each chamber and its oil circuit ensures that the buffering force on the buffer piston 5 varies with its stroke, achieving smooth buffering and effectively controlling the maximum buffering pressure. This prevents damage to mechanical components caused by large pressure pulses during buffering, significantly improving service life. The entire device achieves buffering pressure control and adjustment based on the stroke changes of the buffer piston 5 using a mechanical structure, avoiding reliance on sensor-based circuit systems. This simplified overall structure reduces device and maintenance costs and improves overall reliability.

[0050] In addition, since no external force is transmitted to the buffer piston 5 after braking, the buffer piston 5 moves in the stroke direction under the action of high pressure in the second chamber 14 and hydraulic oil in the third chamber 15. High pressure oil is added to the second chamber 14, the third oil circuit 55 is opened again, and high pressure oil is added to the first chamber 13 until the buffer piston 5 moves in the stroke direction to the equilibrium position.

[0051] It should be noted that the rebound kinetic energy buffer device also includes a low-pressure accumulator 8 and a high-pressure accumulator 9. The low-pressure accumulator 8 is used to connect to the low-pressure oil source 11 and to communicate with the first chamber 13 via the first oil circuit 61. The high-pressure accumulator 9 is used to connect to the high-pressure oil source and to communicate with the second chamber 14 via the second oil circuit 62. The high-pressure accumulator 9 and the low-pressure accumulator 8 can be implemented with reference to the hydraulic system of the rock drill in the prior art. The rebound kinetic energy buffer device also includes a backstop sleeve 3, which is sleeved on the impact piston 4 and set between the buffer piston 5 and the drill bit 2. The backstop sleeve 3 transmits the rebound kinetic energy of the drill bit 2 to the buffer piston 5 and performs preliminary buffering on the rebound of the drill bit 2, reducing the buffering pressure of the buffer piston 5, and thus reducing the maximum pressure value during the buffering process.

[0052] It should be understood that the inner wall of the stop piston sleeve 6 is provided with a first sealing ring for movable sealing cooperation with the buffer piston 5; the inner wall of the buffer piston 5 is provided with a second sealing ring for movable sealing cooperation with the impact piston 4; the equilibrium position is when the buffer piston 5 is approaching the limit position in the stroke direction but has not reached the limit position in the stroke direction.

[0053] In this embodiment, the rebound kinetic energy buffer device further includes a fourth oil passage 56, which is used to connect the low-pressure oil source 11 to the third chamber 15. The rebound kinetic energy buffer device also includes a fifth oil passage 57, which is used to connect the high-pressure oil source to the third chamber 15 when the buffer piston 5 moves to the second preset stroke range. The second preset stroke range is the stroke range that tends to the limit position of the buffer piston 5 in the retracted state. That is, when the buffer piston 5 moves under the action of rebound kinetic energy, it is simultaneously affected by the high-pressure oil in the second chamber 14 and the low-pressure oil in the third chamber 15 to produce a buffering effect. After entering the second preset stroke range, the fifth oil passage 57 is opened, and the high-pressure oil fills the third chamber 15, so that the third chamber 15 forms a high pressure to further buffer the buffer piston 5.

[0054] Specifically, the fifth oil circuit 57 includes a fifth oil port 571 located on the side wall of the buffer piston 5 and a sixth oil port 572 located on the second end face 52 of the buffer piston 5. When it moves to the second preset stroke range, the fifth oil port 571 is connected to the oil circuit on the cylinder 7 that is connected to the high-pressure oil source. After the buffer piston 5 moves to the point of leaving the first preset stroke under the rebound kinetic energy in the equilibrium state, it is first buffered by the negative pressure of the closed first chamber 13 and the instantaneous increase in pressure of the high-pressure oil in the second chamber 14. After decelerating and moving to the second preset stroke range, the high-pressure oil fills the third chamber 15. The buffer piston 5 is buffered by the high-pressure oil in the third chamber 15 and finally completes the braking. Through the structure of this device, the buffer piston 5 is buffered in segments. The first high-pressure braking is performed by the buffer structure and the second high-pressure braking is performed by the second end face 52 of the buffer piston 5. The maximum pressure value of the buffer is effectively controlled, and the damage to the structural components caused by the pressure pulse generated during the buffer is reduced. In addition, the buffer piston 5 and the impact piston 4 have a long distance and a large area of ​​cooperation and contact, which reduces the stress value under the off-center load and improves the life of the impact piston 4.

[0055] Furthermore, the fourth oil passage 56 is connected to the first oil passage 61 and is used to change the flow area between the fourth oil passage 56 and the first oil passage 61 as the stroke of the buffer piston 5 changes. When the buffer piston 5 is in the equilibrium position, the flow area between the fourth oil passage 56 and the first oil passage 61 is the largest. After the buffer piston 5 moves towards the bottom of the cylinder due to the rebound kinetic energy, the flow area between the fourth oil passage 56 and the first oil passage 61 gradually decreases, thereby reducing the return flow rate of the low-pressure oil in the third chamber 15, causing the oil pressure in the third chamber 15 to gradually increase, and the buffer pressure acting on the second end face 52 of the buffer piston 5 to gradually increase, forming an effective buffer. Finally, after the fifth oil passage 57 is opened, the maximum pressure required to introduce high-pressure oil into the third chamber 15 is reduced, reducing the high pressure peak, forming multi-stage buffering, and improving the service life of the device.

[0056] Specifically, the first oil passage 61 is opened in the stop piston sleeve 6, and the inner wall of the stop piston sleeve 6 is provided with an annular groove 611 communicating with the first oil passage 61. The fourth oil passage 56 is opened in the buffer piston 5. The fourth oil passage 56 includes a first oil port 561 located on the outer wall of the buffer piston 5 and a second oil port 562 located on the second end face 52 of the buffer piston 5. The buffer piston 5 is provided with an oil groove 563 at the position of the first oil port 561. The oil groove 563 is used to cooperate with the annular groove 611 and to gradually reduce the cooperation area with the annular groove 611 when the buffer piston 5 moves from the extreme position towards the end of the rod tip 2 to the extreme position away from the end of the rod tip 2. When the buffer piston 5 is in the equilibrium position, the oil groove 563 of the first oil port 561 matches the annular groove 611. As the buffer piston 5 moves, the oil groove 563 and the annular groove 611 gradually misalign, reducing the flow area and reducing the buffer flow rate, thereby increasing the oil pressure in the third chamber 15 to form a buffer.

[0057] Furthermore, as the buffer piston 5 returns to the second preset stroke range and continues to move towards the bottom of the cylinder, the flow area of ​​the first oil passage 61 and the fourth oil passage 56 decreases. When it enters the third preset stroke range, the fourth oil passage 56 disconnects from the first oil passage 61, and the first oil port 561 of the fourth oil passage 56 is sealed by engaging with the inner wall of the stop piston sleeve 6, making the third chamber 15 a closed chamber. Due to the extremely low compressibility of the oil, the third chamber 15 instantly generates a high pressure, and the braking force on the buffer piston 5 increases sharply, forming a high pressure peak in the third chamber 15. The buffer piston 5 is immediately braked and stopped. When the rebound speed drops to zero, it moves in the stroke direction under the action of high-pressure oil in the second chamber 14 and the third chamber 15. High-pressure oil is replenished to the third chamber 15 through the fifth oil passage 57 and to the second chamber 14 through the second oil passage 62. This accelerates the stroke response and provides sufficient oil replenishment. Due to the displacement, the volume of the cavity is formed, ensuring that the pressure of the hydraulic oil is higher than the saturation separation pressure. This achieves the effect of suppressing cavitation and preventing cavitation from occurring during the impact movement of the hydraulic buffer piston 5, thereby improving the service life and reliability of the device.

[0058] It is understandable that the third preset stroke range is within the second preset stroke range and is the stroke range of the buffer piston 5 when it approaches the return limit position.

[0059] It should be understood that the rebound kinetic energy buffer device also includes a sixth oil passage 58, which is used to connect the low-pressure oil source 11 to the inner wall of the buffer piston 5 to provide oil lubrication for the impact piston 4. The sixth oil passage 58 includes a seventh oil port 581 located on the outer wall of the buffer piston 5. During the stroke range of the buffer piston 5, the seventh oil port 581 is located within the range of the annular groove 611, which can maintain the oil supply and simplify the structure.

[0060] In this embodiment, the third oil passage 55 is a flow channel opened in the buffer piston 5. The third oil passage 55 includes a third oil port 551 and a fourth oil port 552. The third oil port 551 is located on the outer wall of the buffer piston 5 on the side of the first buffer surface 53, and the fourth oil port 552 is located on the side wall of the buffer piston 5 on the side of the second buffer surface 54. The fourth oil port 552 is used to cooperate with the inner wall of the cylinder 7 to close the third oil passage 55 when the buffer piston 5 moves to a position outside the first preset stroke range. The third oil port 551 should be located on the first buffer surface 53 or between the side wall of the buffer piston 5 and the first buffer surface 53, or located on the first buffer surface 53, so that the third oil passage 55 is kept in communication with the first chamber 13 through the third oil port 551. The fourth oil port 552 is located on the side wall of the buffer piston 5 on the side of the second buffer surface 54, so that after the buffer piston 5 moves away from the first stroke range, the fourth oil port 552 moves to cooperate with the inner wall of the inner cavity of the cylinder 7 to close the third oil passage 55.

[0061] It should be noted that high-pressure oil is supplied to the third chamber 15 via the first high-pressure oil source 10, and high-pressure oil is supplied to the second chamber 14 via the second high-pressure oil source 12. This allows for separate control of the oil supply pressure to the two chambers, thereby achieving matching of buffer pressures.

[0062] It should be understood that the cylinder block 7 is respectively provided with oil passages so that the first oil passage 61 is connected to the low-pressure accumulator 8, the second oil passage 62 is connected to the high-pressure accumulator 9, and the fifth oil passage 57 is connected to the first high-pressure oil source 10 within the second preset stroke range.

[0063] Example 1

[0064] This embodiment provides a rock drill that incorporates the rebound kinetic energy buffer device described in the preferred embodiment above; such as... Figure 5 As shown, the buffer piston 5 is in a balanced position within the first stroke range. The first oil passage 61 and the fourth oil passage 56 are connected to form the first streamline 16, and the third oil passage 55 connects the first chamber 13 and the second chamber 14 to form the second streamline 17. When the rock drill is in operation, the drill bit 2 rebounds and strikes the anti-reverse sleeve 3. Driven by the rebound of the drill bit 2, the anti-reverse sleeve 3 is pushed to press the buffer piston 5 and move it in the return direction at a higher speed. After moving out of the first preset stroke range, as... Figure 6 As shown, the fourth oil port 552 is covered by the stop piston sleeve 6, sealing the third oil passage 55. The second flow line 17 is disconnected, making the first chamber 13 a closed cavity. There is no oil replenishment in the first chamber 13, and the hydraulic oil pressure inside it drops instantly to zero or to a negative pressure. Meanwhile, a higher pressure is instantly generated in the second chamber 14, which instantly increases the braking force on the buffer piston 5, effectively buffering the buffer piston 5. During the return stroke of the buffer piston 5, the flow area between the fourth oil passage 56 and the first oil passage 61 gradually decreases, and the oil pressure in the third chamber 15 gradually increases, forming a buffer. When the buffer piston 5 continues to move at high speed to the second preset stroke range, such as Figure 7 As shown, high-pressure oil is introduced into the third chamber 15 to form a high-pressure buffer. The oil passage of the cylinder 7 is connected to the fifth oil passage 57 to form the third flow line 18. When moving to the third preset stroke range, as... Figure 8 As shown, at this time, the buffer piston 5 is close to the return limit position. The first oil port 561 disengages from the annular groove 611 and is sealed with the inner wall of the stop piston sleeve 6. The first streamline 16 is broken, making the third chamber 15 a closed chamber, and a high pressure is generated instantaneously to brake the buffer piston 5. In this device, the buffer piston 5 changes with the stroke, causing each chamber to generate buffer pressure changes, achieving a smooth buffering effect and effectively controlling and reducing the highest pressure peak. This reduces the damage to the structural components caused by the pressure pulse generated during buffering and greatly improves the service life.

[0065] In this embodiment, the first preset stroke range is a small value or a point value. That is, when the buffer piston 5 is in the extended equilibrium position, the fourth oil port 552 is in the critical position of being unclosed and tending to be closed. This causes the first chamber 13 to generate negative pressure and the second chamber 14 to generate high pressure to buffer the buffer piston 5 when it is impacted, thereby improving its response speed.

[0066] Through practical application testing, it has been verified that the service life of the rebound kinetic energy buffer device in this embodiment can be increased by more than 10 times compared with the buffer structure of the hydraulic hole generator in the prior art.

[0067] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A rebound kinetic energy buffer device, applied to a hydraulic impact hole forming machine, the hydraulic impact hole forming machine comprising a drill bit (2), a housing assembly (1), and an impact piston (4) passing through the housing assembly (1), characterized in that, The rebound kinetic energy buffer device includes: A buffer piston (5) is sleeved on the impact piston (4). The outer wall of the buffer piston (5) is provided with a buffer structure. The inner wall of the outer shell assembly (1) is provided with a buffer cavity for cooperating with the buffer structure. The end of the buffer structure facing the drill bit (2) is the first buffer surface (53), and the end of the buffer structure away from the drill bit (2) is the second buffer surface (54). A first chamber (13) is formed between the first buffer surface (53) and the inner wall of the buffer chamber; A second chamber (14) is formed between the second buffer surface (54) and the inner wall of the buffer chamber; A third chamber (15) is formed between the end of the buffer piston (5) away from the rod tip (2) and the inner wall of the outer casing assembly (1); The first oil passage (61) is used to connect the low-pressure oil source (11) to the first chamber (13); The second oil passage (62) is used to connect the high-pressure oil source to the second chamber (14); The third oil passage (55) is used to connect the second chamber (14) with the first chamber (13) when the buffer piston (5) moves to the first preset stroke range; The fourth oil passage (56) is used to connect the low-pressure oil source (11) to the third chamber (15), connect to the first oil passage (61), and change the flow area between the first oil passage (61) as the stroke of the buffer piston (5) changes. The fifth oil passage (57) is used to connect the high-pressure oil source to the third chamber (15) when the buffer piston (5) moves to the second preset stroke range; The first oil passage (61) is opened in the outer shell assembly (1). The inner wall of the outer shell assembly (1) is provided with an annular groove (611) communicating with the first oil passage (61). The fourth oil passage (56) includes a first oil port (561) located on the outer wall of the buffer piston (5) and a second oil port (562) located on the end face of the buffer piston (5) away from the drill bit (2). The buffer piston (5) is provided with an oil groove (563) at the position of the first oil port (561). The oil groove (563) is used to cooperate with the annular groove (611) and to gradually reduce the cooperation area with the annular groove (611) when the buffer piston (5) moves from the extreme position toward the end of the drill bit (2) to the extreme position away from the end of the drill bit (2). The sixth oil passage (58) is used to connect the low-pressure oil source (11) to the inner wall of the buffer piston (5) to provide oil lubrication for the impact piston (4). The sixth oil passage (58) includes a seventh oil port (581) located on the outer wall of the buffer piston (5). During the stroke range of the buffer piston (5), the seventh oil port (581) is located within the range of the annular groove (611).

2. The rebound kinetic energy buffer device according to claim 1, characterized in that, The third oil passage (55) is opened in the buffer piston (5). The third oil passage (55) includes a third oil port (551) and a fourth oil port (552). The third oil port (551) is located on the outer wall of the buffer piston (5) on the side of the first buffer surface (53). The fourth oil port (552) is located on the side wall of the buffer piston (5) on the side of the second buffer surface (54). The fourth oil port (552) is used to cooperate with the inner wall of the outer casing assembly (1) to close the third oil passage (55) when the buffer piston (5) moves to a position outside the first preset stroke range.

3. The rebound kinetic energy buffer device according to claim 1, characterized in that, The inner wall of the outer casing assembly (1) is provided with a first sealing ring for movable sealing cooperation with the buffer piston (5); the inner wall of the buffer piston (5) is provided with a second sealing ring for movable sealing cooperation with the impact piston (4).

4. The rebound kinetic energy buffer device according to claim 1, characterized in that, The rebound kinetic energy buffer device further includes a low-pressure accumulator (8) and a high-pressure accumulator (9). The low-pressure accumulator (8) is used to connect to a low-pressure oil source (11) and to communicate with the first chamber (13) via the first oil circuit (61). The high-pressure accumulator (9) is used to connect to the high-pressure oil source and to communicate with the second chamber (14) via the second oil circuit (62).

5. The rebound kinetic energy buffer device according to claim 1, characterized in that, The rebound kinetic energy buffer device also includes a backstop sleeve (3), which is sleeved on the impact piston (4) and positioned between the buffer piston (5) and the drill bit (2).

6. A rock drill, characterized in that, The application has the rebound kinetic energy buffer device as described in any one of claims 1-5.

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