Rebound kinetic energy buffer device and rock drill

Abstract

Disclosed in the present invention are a rebound kinetic energy buffer device and a rock drill, comprising a shank adapter, a housing assembly, and an impact piston passing through the housing assembly. The rebound kinetic energy buffer device comprises: a buffer piston, sleeved on the impact piston, wherein a buffer structure is provided on the outer wall of the buffer piston, a buffer cavity for being matched with the buffer structure is formed in the inner wall of the housing assembly, the end of the buffer structure facing the shank adapter is a first buffer surface, and the end of the buffer structure away from the shank adapter is a second buffer surface; a first chamber, formed between the first buffer surface and the inner wall of the buffer cavity; a second chamber, formed between the second buffer surface and the inner wall of the buffer cavity; a third chamber, formed between the end of the buffer piston away from the shank adapter and the inner wall of the housing assembly; a first oil passage, used for enabling a low-pressure oil source to be communicated with the first chamber; a second oil passage, used for enabling a high-pressure oil source to be communicated with the second chamber; and a third oil passage, used for enabling the second chamber to be communicated with the first chamber when the buffer piston moves to a first preset stroke range.

Description

Rebound kinetic energy buffer device and rock drill

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on December 19, 2023, with application number 202311746947.2 and application name “Rebound kinetic energy buffer device and rock drill”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present invention relates to the field of rock drills, and in particular to a rebound kinetic energy buffer device and a rock drill. Background Art

[0003] The hydraulic impact driller based on the principle of torsion shear comprehensive rock breaking under the action of impact rotation is the most efficient component for drilling short and shallow holes. In order to efficiently transmit the energy generated by the impact driller into the rock in the form of stress waves and achieve the goal of rapid rock breaking and drilling, a buffer mechanism is required to press the drill tool tightly and tightly against the rock mass. After the impact driller has impacted once and produced a certain scale of footage, the impact driller must be pushed forward quickly to compact the rock. Although the impact driller has a propulsion cylinder to push it toward the excavated rock wall, due to the large mass of the moving parts, it is difficult to meet the requirement of quickly compacting the rock under high-frequency impact. Therefore, a corresponding impact driller buffer mechanism is designed in the prior art. When the impact driller has impacted once and produced a certain scale of footage, the buffer hydraulic mechanism can push the drill tool quickly toward the rock wall under the action of hydraulic pressure, thereby achieving efficient rock breaking.

[0004] When the stress wave generated by the impact hole punch is transmitted from the impact piston end face to the interface between the drill bit and the rock, if there are rock debris, cavities, or insufficient propulsion force, a considerable portion of the energy of the stress wave will be transferred back to the impact piston side when it is transmitted to the drill bit end, causing the drill tail to rebound. If the kinetic energy of the drill tail rebound is not buffered, it will be directly transferred to the impact shell or other parts, thereby converting the kinetic energy into internal energy, causing other parts to heat up or break. Therefore, how to effectively buffer the rebound energy of the drill tool is the key to the reliability design of the impact hole punch. The buffer mechanism of the impact hole punch in the prior art mainly adopts pressure-holding braking. The pressure-holding moment will produce a large pressure peak due to the water hammer effect. When the pressure peak acts on the large-area buffer mechanism, it will be subjected to a large impact load, which reduces the life and reliability of the parts.

[0005] For example, Patent No. CN111712353A discloses a rotary impact hydraulic drill comprising a main body, an accessory, a striking piston configured to strike the accessory, the impact piston having a front facing the accessory and a rear wall facing the cavity that accommodates the impact piston; and a main hydraulic supply circuit comprising a high-pressure fluid supply line and a low-pressure fluid return line. The main body and the impact piston define a first control chamber that is permanently connected to the high-pressure fluid supply line and configured to propel the impact piston forward, and a second control chamber that is configured to propel the impact piston forward and is 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 clearly suffers from the problems of a large piston annular cross-section, large energy loss due to throttling of the high-pressure oil, and severe system heating, resulting in the aforementioned problems of short service life and low reliability.

[0006] For another example, Patent No. CN104755230A discloses a buffer device for an impact device, an impact device, a rock drill, and a method for buffering in a rock drill. The method utilizes a buffer flow regulator disposed on a buffer oil circuit for flow regulation, and a control signal is sent to the buffer flow regulator via a control device to regulate the buffer flow. Parameters related to the buffer oil are sensed by sensors, wherein the control device receives signals from the sensors and is used to transmit control signals. The buffer regulator is controlled to maintain a constant or substantially constant buffer flow 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 control systems to achieve buffer regulation, and its reliance on circuit coordination makes it more complex, difficult to maintain, and expensive to repair. Summary of the Invention

[0007] The present invention provides a rebound kinetic energy buffer device and a rock drill, so as to solve the technical problems in the prior art that the buffer structure of the hydraulic impact hole drill is greatly impacted, the structure is easily damaged and the service life is short.

[0008] The technical solution adopted in the present invention is as follows:

[0009] A rebound kinetic energy buffer device is applied to a hydraulic impact hole puncher, wherein the hydraulic impact hole puncher comprises a drill tail, a housing assembly, and an impact piston disposed in the housing assembly. The rebound kinetic energy buffer device comprises:

[0010] A buffer piston is sleeved on the impact piston, wherein the outer wall of the buffer piston is provided with a buffer structure, and the inner wall of the housing assembly is provided with a buffer cavity for cooperating with the buffer structure, wherein the end of the buffer structure facing the shank is a first buffer surface, and the end of the buffer structure away from the shank is a second buffer surface;

[0011] a first chamber formed between the first buffer surface and an inner wall of the buffer cavity;

[0012] a second chamber formed between the second buffer surface and an inner wall of the buffer cavity;

[0013] A third chamber is formed between an end of the buffer piston away from the shank adapter and an inner wall of the housing assembly;

[0014] a first oil circuit, for connecting a low-pressure oil source to the first chamber;

[0015] a second oil circuit, for connecting the high-pressure oil source to the second chamber;

[0016] The third oil circuit is used to connect the second chamber with the first chamber when the buffer piston moves to a first preset stroke range.

[0017] As a further improvement of the above technical solution, the rebound kinetic energy buffer device also includes a fourth oil circuit for connecting the low-pressure oil source to the third chamber, and the rebound kinetic energy buffer device also includes a fifth oil circuit for connecting the high-pressure oil source to the third chamber when the buffer piston moves to a second preset stroke range.

[0018] As a further improvement of the above technical solution, the fourth oil circuit is connected to the first oil circuit and is used to change the flow area between the fourth oil circuit and the first oil circuit as the stroke of the buffer piston changes.

[0019] As a further improvement of the above technical solution, the first oil circuit is opened in the housing component, and the inner wall of the housing component is provided with an annular groove connected with the first oil circuit. The fourth oil circuit 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 end. The buffer piston is provided with an oil groove at the position of the first oil port. 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.

[0020] As a further improvement of the above technical solution, the third oil circuit is opened in the buffer piston, and the third oil circuit 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 housing assembly to close the third oil circuit when the buffer piston moves to a stroke beyond the first preset stroke range.

[0021] As a further improvement of the above technical solution, the inner wall of the shell assembly is embedded with a first sealing ring for movably sealingly cooperating with the buffer piston; the inner wall of the buffer piston is embedded with a second sealing ring for movably sealingly cooperating with the impact piston.

[0022] As a further improvement of the above technical solution, the rebound kinetic energy buffer device also includes a sixth oil circuit for connecting the low-pressure oil source to the inner wall of the buffer piston.

[0023] As a further improvement of the above technical solution, the rebound kinetic energy buffer device also includes a low-pressure accumulator and a high-pressure accumulator, the low-pressure accumulator is used to be connected to a low-pressure oil source and to communicate with the first chamber via the first oil circuit, and the high-pressure accumulator is used to be connected to the high-pressure oil source and to communicate with the second chamber via the second oil circuit.

[0024] As a further improvement of the above technical solution, the rebound kinetic energy buffer device further includes a back-off sleeve, which is sleeved on the impact piston and arranged between the buffer piston and the drill tail.

[0025] According to another aspect of the present invention, a rock drill is provided, which is equipped with any of the above-mentioned rebound kinetic energy buffer devices.

[0026] The present invention has the following beneficial effects:

[0027] When the buffer piston is in the equilibrium position, it is in an extended state toward the shank. During operation, the kinetic energy generated by the rebound of the shank acts on the buffer piston, causing the buffer piston to move toward the end away from the shank. The high-pressure oil in the second chamber acts on the second buffer surface to form a buffer for the buffer piston. The first preset stroke range includes the buffer piston's stroke direction limit position and the stroke range tending to the stroke direction limit position. That is, after the buffer piston is moved a certain distance away from the shank direction by the kinetic energy of the shank rebound, it leaves the first preset stroke range, thereby 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 instantly, and a higher pressure to be generated instantly in the second chamber, causing its braking force on the buffer piston to increase instantly, so that the buffer piston is effectively buffered. The third chamber is connected to the hydraulic oil supply control circuit of the device, that is, the third chamber is filled with hydraulic oil to buffer the buffer piston, so that the buffer piston is affected by the rebound return stroke. During the action, it is continuously buffered by the hydraulic oil in the third chamber, so that the braking process is completed under the coordinated action of the first chamber, the second chamber and the third chamber; based on the use of this rebound kinetic energy buffer device, three chambers are formed respectively through the cooperation of the buffer piston and the buffer structure with the inner cavity of the shell component and the buffer cavity, and each chamber and its oil circuit cooperate to make the buffer force received by the buffer piston change with its stroke, thereby achieving smooth buffering, and then effectively controlling the maximum pressure value of the buffer, reducing the damage to the mechanical structure caused by the pressure pulse generated during buffering, and significantly improving the service life. After actual test verification, the service life of the buffer structure of the hydraulic hole former in the prior art can be increased by more than 10 times; the overall device is based on the mechanical structure to realize the control and adjustment of the buffer pressure according to the stroke change of the buffer piston, avoiding dependence on the circuit system of the application sensor, reducing the device cost and maintenance cost, and improving the overall reliability of the device.

[0028] In addition to the above-described objects, features and advantages, the present invention has other objects, features and advantages. The present invention will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings, which constitute a part of this application, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0030] In the attached figure:

[0031] FIG1 is a schematic cross-sectional view of a buffer piston in a balanced state according to a preferred embodiment of the present invention;

[0032] FIG2 is a schematic cross-sectional view of the buffer piston in a preferred embodiment of the present invention at a return limit position;

[0033] FIG3 is a schematic cross-sectional view of a buffer piston according to a preferred embodiment of the present invention;

[0034] FIG4 is a schematic structural diagram of a buffer piston according to a preferred embodiment of the present invention;

[0035] FIG5 is a schematic diagram of a buffer piston in a first preset stroke range according to a preferred embodiment of the present invention;

[0036] FIG6 is a schematic diagram of a buffer piston disengaging from a first preset stroke range according to a preferred embodiment of the present invention;

[0037] 7 is a schematic diagram of a buffer piston in a second preset stroke range according to a preferred embodiment of the present invention;

[0038] FIG8 is a schematic diagram of a buffer piston in a third preset stroke range according to a preferred embodiment of the present invention;

[0039] 1. Housing assembly; 2. Shank tail; 3. Backstop 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 circuit; 551. Third oil port; 552. Fourth oil port; 56. Fourth oil circuit; 561. First oil port; 562. Second oil port; 563. Oil groove; 57. Fifth oil circuit; 571. Fifth oil port; 572. Sixth Oil port; 58, sixth oil circuit; 581, seventh oil port; 6, stop piston sleeve; 61, first oil circuit; 611, annular groove; 62, second oil circuit; 7, cylinder body; 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 DESCRIPTION

[0040] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0041] 1 to 8 , a preferred embodiment of the present invention provides a rebound kinetic energy buffer device, which is applied to a hydraulic impact hole puncher. The hydraulic impact hole puncher includes a drill adapter 2, a housing assembly 1, and an impact piston 4 disposed within the housing assembly 1. The rebound kinetic energy buffer device includes:

[0042] The 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 housing assembly 1 is provided with a buffer cavity for cooperating with the buffer structure. The end of the buffer structure facing the shank 2 is a first buffer surface 53, and the end of the buffer structure away from the shank 2 is a second buffer surface 54. The buffer piston 5 includes a first end surface 51 facing the shank 2 and a second end surface 52 away from the shank 2.

[0043] The first chamber 13 is formed between the first buffer surface 53 and the inner wall of the buffer cavity;

[0044] The second chamber 14 is formed between the second buffer surface 54 and the inner wall of the buffer cavity;

[0045] The third chamber 15 is formed between the end of the buffer piston 5 away from the shank adapter 2 and the inner wall of the housing assembly 1, and is used to connect to the hydraulic oil supply control circuit of the device to cushion the buffer piston 5 when it is subjected to rebound kinetic energy and performs a return stroke.

[0046] The first oil passage 61 is used to connect the low-pressure oil source 11 to the first chamber 13;

[0047] The second oil passage 62 is used to connect the high-pressure oil source to the second chamber 14;

[0048] 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.

[0049] Among them, the housing assembly 1 includes a cylinder body 7 and a stop piston sleeve 6 arranged in the cylinder body 7. The stop piston sleeve 6 cooperates with the inner wall of the cylinder body 7 and is sleeved on the outer wall of the buffer piston 5. The buffer cavity is formed on the inner wall of the stop piston sleeve 6 at one end facing the cylinder body 7; the length of the buffer cavity matches the stroke of the buffer piston 5 or its length 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 circuit 61 includes a first flow channel opened in the stop piston sleeve, and the second oil circuit 62 includes a second flow channel opened in the cylinder body 7 or opened in the stop piston sleeve or arranged between the cylinder body 7 and the stop piston sleeve;

[0050] The working principle of this rebound kinetic energy buffer device:

[0051] When the buffer piston 5 is in the equilibrium position, it is in an extended state toward the shank 2. During operation, the kinetic energy generated by the rebound of the shank 2 acts on the buffer piston 5, causing the buffer piston 5 to move toward the end away from the shank 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 stroke direction limit position of the buffer piston 5 and the stroke range tending to the stroke direction limit position, that is, after the buffer piston 5 is moved a certain distance away from the shank 2 by the rebound kinetic energy of the shank 2, 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 instantly drop to zero or to be negative pressure, and a higher pressure will be instantly generated in the second chamber 14, causing its braking force on the buffer piston 5 to instantly increase, so that the buffer piston 5 is effectively buffered. 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. Buffering is performed so that the buffer piston 5 is continuously buffered by the hydraulic oil in the third chamber 15 during the rebound return action, so that the braking process is completed under the coordinated action of the first chamber 13, the second chamber 14 and the third chamber 15; based on the use of this rebound kinetic energy buffer device, the first chamber 13 and the second chamber 14 are respectively formed through the cooperation of the buffer structure of the buffer piston 5 and the buffer cavity of the housing assembly 1, which enriches the buffer control means, and the various chambers and their oil circuits cooperate to make the buffer force received by the buffer piston 5 change with its stroke, thereby achieving smooth buffering, and then effectively controlling the maximum pressure value of the buffer, avoiding the generation of large pressure pulses during buffering to cause damage to mechanical structural parts, and significantly improving the service life; the overall device is based on the mechanical structure to realize the control and adjustment of the buffer pressure according to the stroke change of the buffer piston 5, avoiding dependence on the circuit system of the application sensor, and the overall structure is streamlined, reducing the device cost and maintenance cost, and improving the overall reliability of the device;

[0052] In addition, since no external force is transmitted to the buffer piston 5 after the braking is completed, the buffer piston 5 moves in the stroke direction under the action of the high pressure in the second chamber 14 and the hydraulic oil in the third chamber 15, and the high-pressure oil is replenished into the second chamber 14. The third oil circuit 55 is opened again, and the high-pressure oil is replenished into the first chamber 13 until the buffer piston 5 moves in the stroke direction to the equilibrium position.

[0053] 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 be connected to the low-pressure oil source 11 and to be communicated with the first chamber 13 via the first oil circuit 61. The high-pressure accumulator 9 is used to be connected to the high-pressure oil source and to be communicated 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 stop sleeve 3, which is sleeved on the impact piston 4 and arranged between the buffer piston 5 and the drill tail 2. The rebound kinetic energy of the drill tail 2 is transferred to the buffer piston 5 through the stop sleeve 3, and the rebound of the drill tail 2 is preliminarily buffered, thereby reducing the buffering pressure of the buffer piston 5, thereby reducing the maximum pressure value during the buffering process.

[0054] It should be understood that the inner wall of the stop piston sleeve 6 is embedded with a first sealing ring for movably sealingly cooperating with the buffer piston 5; the inner wall of the buffer piston 5 is embedded with a second sealing ring for movably sealingly cooperating with the impact piston 4; the equilibrium position is when the buffer piston 5 approaches the stroke direction limit position but has not reached the stroke direction limit position;

[0055] In this embodiment, the rebound kinetic energy buffer device further includes a fourth oil circuit 56 for connecting the low-pressure oil source 11 to the third chamber 15. The rebound kinetic energy buffer device further includes a fifth oil circuit 57 for connecting the high-pressure oil source to the third chamber 15 when the buffer piston 5 moves to a second preset stroke range. The second preset stroke range is a stroke range tending to the extreme position of the retracted state of the buffer piston 5. That is, when the buffer piston 5 moves under the action of the 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 circuit 57 is connected, and the high-pressure oil is filled into the third chamber 15, so that high pressure is formed in the third chamber 15 to further buffer the buffer piston 5.

[0056] 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 the buffer piston 5 moves to the second preset stroke range, the fifth oil port 571 is connected to the oil circuit connected to the high-pressure oil source on the cylinder body 7. After the buffer piston 5 moves out of the first preset stroke in a balanced state due to the rebound kinetic energy, it is first subjected to the negative pressure of the closed first chamber 13 and the instantaneous increase in the pressure of the high-pressure oil in the second chamber 14 to produce buffering. 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 braking. The structure of this device performs segmented buffering on the buffer piston 5, with the first high-pressure braking being performed by the buffer structure and the second high-pressure braking being performed by the second end face 52 of the buffer piston 5. This effectively controls the maximum pressure value of the buffer and reduces damage to structural components caused by pressure pulses generated during buffering. In addition, the buffer piston 5 and the impact piston 4 have a long distance, large-area fit and contact, which reduces the stress value under the action of the eccentric load and improves the service life of the impact piston 4.

[0057] 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. Specifically, 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 toward the cylinder bottom 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 oil flow rate of the low-pressure oil in the third chamber 15, gradually increasing the oil pressure in the third chamber 15, and gradually increasing the buffering pressure acting on the second end face 52 of the buffer piston 5, thereby forming an effective buffer. Finally, after the fifth oil passage 57 is opened, the maximum pressure required for the high-pressure oil to enter the third chamber 15 is reduced, thereby reducing the high-pressure peak, forming a multi-stage buffer, and improving the service life of the device.

[0058] Specifically, the first oil circuit 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 connected with the first oil circuit 61. The fourth oil circuit 56 is opened in the buffer piston 5. The fourth oil circuit 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 toward the end of the shank tail 2 to the extreme position away from the end of the shank tail 2. The oil groove 563 of the first oil port 561 matches the annular groove 611 when the buffer piston 5 is in the equilibrium position. As the buffer piston 5 moves, the oil groove 563 and the annular groove 611 are gradually misaligned, thereby reducing the flow area and reducing the buffer flow, thereby increasing the oil pressure in the third chamber 15 to form a buffer.

[0059] Furthermore, when the buffer piston 5 returns to the second preset stroke range and continues to move toward the cylinder bottom, the flow areas of the first oil path 61 and the fourth oil path 56 decrease. When entering the third preset stroke range, the fourth oil path 56 is disconnected from the first oil path 61, and the first oil port 561 of the fourth oil path 56 cooperates with the inner wall of the stop piston sleeve 6 to be sealed, so that the third chamber 15 is formed into a closed chamber. Due to the extremely low compressibility of the oil, the third chamber 15 instantly generates a higher 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 brakes to a stop immediately. When the rebound velocity drops to zero, it moves in the stroke direction under the action of the high-pressure oil in the second chamber 14 and the third chamber 15. High-pressure oil is replenished into the third chamber 15 through the fifth oil passage 57, and high-pressure oil is replenished into the second chamber 14 through the second oil passage 62. This accelerates the stroke response and provides sufficient oil to replenish the volume of the cavity formed by the displacement, ensuring that the pressure of the hydraulic oil is higher than the saturated separation pressure, thereby achieving 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.

[0060] It can be understood that the third preset stroke range is within the second preset stroke range and is the stroke range in which the buffer piston 5 approaches the return limit position.

[0061] It should be understood that the rebound kinetic energy buffer device also includes a sixth oil circuit 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 to the impact piston 4. The sixth oil circuit 58 includes a seventh oil port 581 located on the outer wall of the buffer piston 5. Within the stroke range of the buffer piston 5, the seventh oil port 581 is located within the annular groove 611, thereby maintaining the oil supply and streamlining the structure.

[0062] In this embodiment, the third oil circuit 55 is a flow channel opened in the buffer piston 5, and the third oil circuit 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 body 7 to close the third oil circuit 55 when the buffer piston 5 moves to a stroke outside the first preset stroke range; wherein, 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 on the first buffer surface 53, so that the third oil circuit 55 remains connected to the first chamber 13 through the third oil port 551, 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, that is, after the buffer piston 5 moves out of the first stroke range, the fourth oil port 552 moves to cooperate with the inner wall of the inner cavity of the cylinder body 7 to achieve the closure of the third oil circuit 55.

[0063] It should be noted that high-pressure oil is supplied to the third chamber 15 through the first high-pressure oil source 10, and high-pressure oil is supplied to the second chamber 14 through the second high-pressure oil source 12, so that the oil supply pressures of the two chambers can be controlled separately to achieve buffer pressure matching.

[0064] It should be understood that the cylinder body 7 is respectively provided with oil circuits to connect the first oil circuit 61 with the low-pressure accumulator 8, the second oil circuit 62 with the high-pressure accumulator 9, and the fifth oil circuit 57 with the first high-pressure oil source 10 within the second preset stroke range.

[0065] Example 1

[0066] The present embodiment provides a rock drill, which is applied with the rebound kinetic energy buffer device of the above-mentioned preferred embodiment; as shown in FIG5 , the buffer piston 5 is in a balanced position within the first stroke range, the first oil path 61 and the fourth oil path 56 are connected to form a first streamline 16, and the third oil path 55 is connected to the first chamber 13 and the second chamber 14 to form a second streamline 17. When the rock drill is in operation, the drill tail 2 rebounds and hits the stop sleeve 3. Driven by the rebound of the drill tail 2, the stop sleeve 3 is pushed to press the buffer piston 5 and move it in the return direction at a high speed. After moving out of the first preset stroke range, as shown in FIG6 , the fourth oil port 552 is covered by the stop piston sleeve 6, closing the third oil path 55, and the second streamline 17 is disconnected, so that the first chamber 13 becomes a closed cavity. No oil is replenished in the first chamber 13, and the hydraulic oil pressure therein drops to zero or to negative pressure instantly. A higher pressure is instantly generated in the second chamber 14, which instantly increases the braking force on the buffer piston 5, so that the buffer piston 5 is effectively buffered. During the return movement of the buffer piston 5, the flow area between the fourth oil circuit 56 and the first oil circuit 61 gradually decreases, and the oil pressure in the third chamber 15 gradually increases to form a buffer. When the buffer piston 5 continues to move at high speed to the second preset stroke range, as shown in Figure 7, high-pressure oil is introduced into the third chamber 15 to form a high-pressure buffer, and the oil circuit of the cylinder body 7 is connected to the fifth oil circuit 57 to form a third streamline 18. When it moves to the third preset stroke range, as shown in Figure 8, the buffer piston 5 is close to the return limit position, the first oil port 561 is separated from the annular groove 611 and sealed with the inner wall of the stop piston sleeve 6, and the first streamline 16 is disconnected, so that the third chamber 15 is formed into a closed chamber, and a higher pressure is instantly generated to brake the buffer piston 5; in this device, the buffer piston 5 changes with the stroke, so that each chamber produces a buffer pressure change respectively, thereby achieving a smooth buffering effect and effectively controlling and reducing the maximum pressure peak, reducing the damage to the structural parts caused by the pressure pulse generated during buffering, and greatly improving the service life.

[0067] In this embodiment, the first preset stroke range is a smaller value or point value, that is, when the buffer piston 5 is in the extended equilibrium position, the fourth oil port 552 is in a critical position between being unclosed and tending to be closed, so that the first chamber 13 generates negative pressure and the second chamber 14 generates high pressure at the moment the buffer piston 5 is impacted to buffer it, thereby improving its response speed.

[0068] After actual application tests and verification, the rebound kinetic energy buffer device of this embodiment can increase the service life by more than 10 times compared with the buffer structure of the hydraulic hole-making tool in the prior art.

[0069] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A rebound kinetic energy buffer device, applied to a hydraulic impact hole-forming device, the hydraulic impact hole-forming device comprising a drill tail (2), a housing component (1), and an impact piston (4) inserted into the housing component (1), characterized in that: The rebound kinetic energy buffer device comprises: 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 housing assembly (1) is provided with a buffer cavity for cooperating with the buffer structure; the end of the buffer structure facing the shank (2) is a first buffer surface (53); and the end of the buffer structure away from the shank (2) is a second buffer surface (54); A first chamber (13) formed between the first buffer surface (53) and the inner wall of the buffer cavity; A second chamber (14) formed between the second buffer surface (54) and an inner wall of the buffer cavity; A third chamber (15) is formed between an end of the buffer piston (5) away from the shank (2) and an inner wall of the housing assembly (1); A first oil passage (61) for connecting the low-pressure oil source (11) to the first chamber (13); A second oil passage (62) for connecting the high-pressure oil source to the second chamber (14); The third oil circuit (55) is used to connect the second chamber (14) with the first chamber (13) when the buffer piston (5) moves to a first preset stroke range.

2. The rebound kinetic energy buffer device according to claim 1, characterized in that: The rebound kinetic energy buffer device also includes a fourth oil circuit (56) for connecting the low-pressure oil source (11) to the third chamber (15), and the rebound kinetic energy buffer device also includes a fifth oil circuit (57) for connecting the high-pressure oil source to the third chamber (15) when the buffer piston (5) moves to a second preset stroke range.

3. The rebound kinetic energy buffer device according to claim 2, characterized in that: 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.

4. The rebound kinetic energy buffer device according to claim 3, characterized in that: The first oil circuit (61) is provided in the housing component (1); the inner wall of the housing component (1) is provided with an annular groove (611) connected with the first oil circuit (61); the fourth oil circuit (56) comprises 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 shank tail (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 shank tail (2) end to the extreme position away from the shank tail (2) end.

5. The rebound kinetic energy buffer device according to claim 1, characterized in that: The third oil circuit (55) is opened in the buffer piston (5), and the third oil circuit (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 housing assembly (1) to close the third oil circuit (55) when the buffer piston (5) moves to a stroke outside the first preset stroke range.

6. The rebound kinetic energy buffer device according to claim 1, characterized in that: The inner wall of the housing component (1) is embedded with a first sealing ring for movably sealingly cooperating with the buffer piston (5); the inner wall of the buffer piston (5) is embedded with a second sealing ring for movably sealingly cooperating with the impact piston (4).

7. The rebound kinetic energy buffer device according to claim 1, characterized in that: The rebound kinetic energy buffer device also includes a sixth oil passage (58) for connecting the low-pressure oil source (11) to the inner wall of the buffer piston (5).

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

9. The rebound kinetic energy buffer device according to claim 1, characterized in that: The rebound kinetic energy buffer device also includes a stop sleeve (3) which is sleeved on the impact piston (4) and arranged between the buffer piston (5) and the shank (2).

10. A rock drill, characterized in that: The rebound kinetic energy buffer device according to any one of claims 1 to 9 is used.

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