Hydraulic rock drill provided with hydraulic stop piston
The multi-stage buffer design of the hydraulic stop piston solves the problem of the drill bit rebound energy not being absorbed, thus protecting the rock drill parts and improving energy transfer efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CHINA RAILWAY CONSTR HEAVY IND
- Filing Date
- 2025-05-26
- Publication Date
- 2026-05-12
AI Technical Summary
In existing technologies, the rebound energy generated when the drill bit strikes the rock cannot be completely absorbed, leading to damage to the internal parts of the rock drill and affecting its service life and reliability.
The design employs a hydraulic stop piston, which absorbs the rebound energy of the drill bit through the buffering mechanism of the first, second, and third control chambers. The hydraulic stop piston provides a stable propulsion force, ensuring that the drill bit remains stable in the preset position on the impact surface, thus achieving continuous and smooth buffer protection.
It effectively absorbs the rebound energy of the drill bit, prevents stress wave propagation, protects the machine body and internal components, and improves the lifespan and energy transfer efficiency of the rock drill.
Smart Images
Figure CN224229005U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to rock drill technology field, concretely relates to a hydraulic rock drill with hydraulic stop piston. BACKGROUND
[0002] Rock drill is through piston rod to impact drill tail, and the kinetic energy of piston rod is converted into stress wave energy and is transmitted to the inside of rock, thereby realizing rock breaking. But because drill and rock all have elastic characteristics, drill will certainly produce violent rebound after impacting rock, and the kinetic energy carried by it will be directly transmitted to the internal parts of rock drill if not effectively absorbed. This will not only cause violent vibration and noise, but more seriously, will cause damage to internal parts, and then affect the service life and reliability of rock drill. In addition, the vibration and rebound produced by drill bit under repeated impact on rock will cause the tool supporting drill rod to relatively displace on rock, and the unstable support force of drill bit on rock will affect the positioning of drill tail relative to impact piston, and then affect the performance of hydraulic rock drill.
[0003] Chinese patent CN115075723A discloses a hydraulic rotary impact hammer drill with stop piston, comprising: a body; a drill tail; an impact piston for impacting the drill tail; a stop piston for positioning the drill tail at a predetermined balance position. The body and the stop piston define a first control chamber and a second control chamber, the first control chamber is permanently connected to a high-pressure fluid supply pipeline and is configured to forwardly push the stop piston; the second control chamber is configured to forwardly push the stop piston. The hydraulic rotary impact hammer drill includes a fluid communication channel that opens to the second control chamber, is configured to supply the second control chamber with high-pressure fluid, and is provided with a calibration port.
[0004] However, the patent has the following problems: the stop piston needs the body to be forwardly limited, and the condition that the stop piston keeps a distance from the machine body is that the impact piston stop plane is located at the edge of the brake chamber when the piston impacts the drill tail. The first control chamber will be communicated with the oil return pipeline, at this time the buffer force acting on the stop piston will disappear. The first control chamber and the second control chamber can be communicated, and share a high-pressure oil, and at the same time the second control chamber is permanently connected with the main control chamber of the impact piston, and does not form a closed chamber, causing part of the energy to be lost with the leakage of fluid, and unable to be effectively converted into impact energy, thereby reducing the energy utilization rate of the whole system. The pressure loss caused by the unsealed chamber may cause the internal parts of the rock drill to bear excessive load, thereby increasing the risk of damage to the rock drill. For example, the impact piston and the stop piston may be damaged due to lack of sufficient buffer force.
[0005] In summary, there is an urgent need for a buffer device that can absorb and utilize the rebound energy of the drill tail to solve the problems in the prior art. UTILITY MODEL CONTENT
[0006] The utility model aims at providing a hydraulic rock drill with hydraulic stop piston, to solve the technical problem that the rebound energy generated after the drill impacts the rock cannot be completely absorbed, resulting in damage to the internal parts of the rock drill, and the specific technical scheme is as follows:
[0007] The utility model provides a hydraulic rock drill with hydraulic stop piston, including rock drill body, sleeve assembly, impact piston, hydraulic stop piston and drill tail, the sleeve assembly is installed inside the rock drill body, the hydraulic stop piston is installed in the sleeve assembly, the impact piston is worn in the hydraulic stop piston, the drill tail is installed in the rock drill body and is located the hydraulic stop piston front end position, the hydraulic stop piston with the sleeve assembly forms first control chamber, second control chamber and third control chamber for buffering, the impact piston with the drill tail forms lubricating chamber.
[0008] The further improvement of the hydraulic rock drill with hydraulic stop piston of the utility model lies in that the sleeve assembly includes first inner sleeve, second inner sleeve and third inner sleeve which are butted in sequence from the drill tail to the inside of the rock drill body, the first control chamber is formed by surrounding the first inner sleeve and the hydraulic stop piston, the second control chamber is formed by surrounding the first inner sleeve, the second inner sleeve and the hydraulic stop piston, and the third control chamber is formed by surrounding the second inner sleeve and the rear end surface of the hydraulic stop piston.
[0009] The further improvement of the hydraulic rock drill with hydraulic stop piston of the utility model lies in the first connecting channel in the hydraulic stop piston, the first connecting channel is communicated with the first control chamber and the second control chamber when the drill tail is in the impact state, and the second control chamber is connected to the first high-pressure oil source.
[0010] The further improvement of the hydraulic rock drill with hydraulic stop piston of the utility model lies in a signal channel and a control channel which are communicated in the hydraulic stop piston, the control channel is communicated with the third control chamber, the first inner sleeve is provided with annular groove, the annular groove is connected to the low-pressure oil source, and the signal channel is communicated with the annular groove when the hydraulic stop piston is in the neutral position within the preset range.
[0011] The further improvement of the hydraulic rock drill with hydraulic stop piston of the utility model lies in fourth control chamber between the second inner sleeve, the third inner sleeve and the impact piston, the fourth control chamber is always connected to the first high-pressure oil source, and the control end surface of the impact piston is in contact with the third inner sleeve.
[0012] The further improvement of the hydraulic rock drill provided with the hydraulic stop piston lies in that a fifth control chamber is formed between the third inner sleeve and the impact piston, the third inner sleeve is provided with a reversing valve, the reversing valve is used for being connected to a first high-pressure oil source and a low-pressure oil source, and the reversing valve is connected to the fifth control chamber.
[0013] The further improvement of the hydraulic rock drill provided with the hydraulic stop piston lies in that the front end of the hydraulic stop piston is provided with a retreat-stop bushing.
[0014] The technical scheme of the utility model has the following beneficial effects:
[0015] The hydraulic rock drill provided with the hydraulic stop piston, through the buffering of the first control chamber, the second control chamber and the third control chamber of the hydraulic stop piston, timely response pushing force is provided, the impact energy in the drill tail rebound process is absorbed, the continuous and stable buffering protection effect is achieved; meanwhile, the hydraulic stop piston provides appropriate pushing force following the impact piston, so that the drill tail impact surface is stably positioned at the preset position when retreating, the consistency of the relative displacement of the impact piston when hammering the drill tail each time is ensured, the rock drill frequency is ensured to be stable, and the technical problem that the rebound energy after the drill impacts the rock in the prior art cannot be completely absorbed and the internal parts of the rock drill are damaged is solved.
[0016] In addition to the purposes, features and advantages described above, the utility model has other purposes, features and advantages. BRIEF DESCRIPTION OF DRAWINGS
[0017] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application, and are incorporated herein for purposes of explanation and are not intended to limit the application. In the drawings:
[0018] Figure 1 is an external structure schematic view of the hydraulic rock drill provided with the hydraulic stop piston of the utility model;
[0019] Figure 2 is a longitudinal sectional view of the hydraulic rock drill provided with the hydraulic stop piston of the utility model;
[0020] Figure 3 is Figure 2 the enlarged view of
[0021] Wherein, 1- rock drill machine body; 2- first inner sleeve; 3- second inner sleeve; 4- third inner sleeve; 5- impact piston; 6- fourth control chamber; 7- fifth control chamber; 8- reversing valve; 9- first high pressure oil source; 10- high pressure accumulator; 11- low pressure oil source; 12- low pressure accumulator; 13- hydraulic stop piston; 14- lubrication chamber; 15- drill shank; 16- first connecting channel; 17- drill shank impact surface; 18- bearing surface; 19- control end surface; 20- retreat stop bushing; 21- third control surface; 22- second control chamber; 23- high pressure fluid channel; 24- third control chamber; 25- first control port; 26- second connecting channel; 27- second high pressure oil source; 28- second control surface; 29- third connecting channel; 30- first control chamber; 31- first control surface; 32- low pressure fluid channel; 33- control channel; 34- low pressure annular groove; 35- second control port; 36- hydraulic rotary motor; 37- signal channel; 38- high pressure cavity. DETAILED DESCRIPTION
[0022] The embodiments of the utility model will be described in detail below with reference to the drawings.
[0023] Referring to Figures 1-3 As shown in the figure, a hydraulic rock drill provided with a hydraulic stop piston, comprising a rock drill machine body 1, a sleeve assembly, an impact piston 5, a hydraulic stop piston 13 and a drill shank 15; the sleeve assembly is installed inside the rock drill machine body 1, the hydraulic stop piston 13 is installed in the sleeve assembly, the impact piston 5 is arranged in the hydraulic stop piston 13, and the drill shank 15 is installed in the rock drill machine body 1 and located at the front end position of the hydraulic stop piston 13; the first control chamber 30, the second control chamber 22 and the third control chamber 24 for buffering are formed between the hydraulic stop piston 13 and the sleeve assembly, and the lubrication chamber 14 is formed between the impact piston 5 and the drill shank 15.
[0024] The impact piston 5 is installed inside the rock drill machine body 1 and can reciprocate along the impact axis A to hammer the drill shank 15. When the impact piston 5 reciprocates to hammer the drill shank, the reciprocation of the drill shank 15 pushes the hydraulic stop piston 13 to reciprocate along the impact axis A. The hydraulic rotary motor 36 is arranged on the rock drill machine body 1 to provide rotation for the rock drill. The utility model adopts the multi-stage buffering mode, so that the buffering force acting on the stop piston changes with the change of its stroke, thereby realizing smooth buffering.
[0025] Preferably, the sleeve assembly includes a first inner sleeve 2, a second inner sleeve 3, and a third inner sleeve 4 sequentially connected from the drill bit 15 into the interior of the rock drill body 1. A first control chamber 30 is formed between the hydraulic stop piston 13 and the first inner sleeve 2. A second control chamber 22 is formed together with the hydraulic stop piston 13, the first inner sleeve 2, and the second inner sleeve 3. A third control chamber 24 is formed between the rear end face of the hydraulic stop piston 13 and the second inner sleeve 3. A protruding ring is provided in the middle of the hydraulic stop piston 13, with a first control surface 31 on its front end face. The first control surface 31 and the first inner sleeve 2 form the first control chamber 30. A second control surface 28 is provided on the rear end face of the protruding ring, and the second control surface 28, the first inner sleeve 2, and the second inner sleeve 3 together form the second control chamber 22. A third control surface 21 is provided on the rear end face of the hydraulic stop piston 13, and the third control surface 21 and the second inner sleeve 3 surround to form the third control chamber 24.
[0026] like Figure 3 As shown, the front and rear inner walls of the first control chamber 30 are inclined to increase the contact area between the hydraulic stop piston 13 and the first inner sleeve 2, so that the load generated by the forward impact of the hydraulic brake piston 13 is evenly distributed, avoiding component damage caused by stress concentration. The first control chamber 30, the second control chamber 22 and the third control chamber 24 of the present invention are arranged sequentially, and the distance between the first control chamber 30, the second control chamber 22 and the third control chamber 24 and the first control port 25 and the second control port 35 is preset. The purpose is to ensure that the hydraulic stop piston 13 is always pressed against the anti-reverse bushing 20 under the propulsion of hydraulic oil, so that the anti-reverse bushing 20 and the drill bit 15 are always in contact.
[0027] When the hydraulic stop piston 13 moves forward a preset stroke A, the first control port 25 connects to the second control chamber 22, enabling the first control chamber 30 to be connected to the first high-pressure oil source 9, thereby causing the hydraulic stop piston 13 to decelerate and brake. The distance between the two inclined end faces of the first control chamber 30 is also a preset gap B (this gap is the minimum gap; to provide protection, the actual gap must be at least greater than this gap), thus ensuring that the two inclined end faces will not collide when the hydraulic brake piston decelerates completely to 0.
[0028] The distance between the rear end face of the second control chamber 22, the first control port 25, the second control port 35, and the high-pressure chamber 38 is preset. When the hydraulic stop piston 13 retracts a preset stroke C, the first control port 25 is disconnected from the second control chamber 22. After retracting a preset distance D, the second control port 35 is connected to the high-pressure chamber 38, enabling the third control chamber 24 to connect to the first high-pressure oil source 9, and the retraction deceleration of the hydraulic stop piston 13 begins.
[0029] The distance between the front and back end faces of the second control chamber 22 and the distance between the front and back end faces of the third control chamber 24 are pre-set. When the hydraulic stop piston 13 is at a speed of 0, the front and back end faces of the second control chamber 22 and the front and back end faces of the third control chamber 24 do not contact each other, so as to avoid impact and protect the parts.
[0030] Preferably, the hydraulic stop piston 13 is provided with a first connecting channel 16. When the bit 15 is in the impact state and the hydraulic stop piston 13 moves to the pre-set position, the first control port 25 is in communication with the second control chamber 22, and the first connecting channel 16 is in communication with the first control chamber 30 and the second control chamber 22. The second control chamber 22 is always connected to the first high-pressure oil source 9. The second control face 28 generates a stable and continuous force under the action of high pressure in the second control chamber 22, and provides a stable support force acting on the stop sleeve 20, and then acting on the bit 15. The first control port 25 is arranged at the rear opening end of the first connecting channel 16. The rock drill body 1 is provided with a high-pressure fluid channel 23 for the oil source of the first high-pressure oil source 9. The high-pressure fluid channel 23 is in communication with the high-pressure accumulator 10. When the pressure in the buffer cavity is very high, the pressure oil will be pressed back to the high-pressure accumulator 10 to store energy.
[0031] Preferably, the hydraulic stop piston 13 is provided with a signal channel 37 and a control channel 33 in communication. The control channel 33 is in communication with the third control chamber 24. The first inner sleeve 2 is provided with an annular groove 34 connected to the low-pressure oil source 11. When the hydraulic stop piston 13 is in the neutral position within the pre-set range, the signal channel 37 is in communication with the annular groove 34. When the bit 15 impacts the stop sleeve 20, the stop sleeve 20 contacts the hydraulic stop piston 13. Under the impact of the bit 15, the hydraulic stop piston 13 moves backward, which causes the signal channel 37 to be disconnected from the annular groove 34, so as to avoid the oil in the third control chamber 24 flowing back to the low-pressure oil source 11 through the control channel 33, the signal channel 37 and the annular groove 34. When the bit 15 is moved forward after being impacted by the impact piston 5, the stop sleeve 20 and the hydraulic stop piston 13 move forward together, which causes the signal channel 37 to be in communication with the annular groove 34, so as to make the oil in the third control chamber 24 flow back to the low-pressure oil source 11 through the control channel 33, the signal channel37 and the annular groove 34. The diameter of the annular groove 34 is greater than the diameter of the signal channel 37. The communication area changes with the axial position of the hydraulic stop piston 13, so as to continuously and smoothly buffer and protect.
[0032] Further, the second inner sleeve 3 is provided with a high pressure cavity 38 and a second connecting channel 26 connected to a second high pressure oil source 27. A third connecting channel 29 is provided in the hydraulic stop piston 13, and a second control port 35 is provided at the front end of the third connecting channel 29. The rear end of the third connecting channel 29 is in communication with the third control chamber 24. When the hydraulic stop piston 13 moves backward by a preset displacement, the second control port 35 is in communication with the second connecting channel 26, and the third control chamber 24 is also in communication with the high pressure cavity 38 and the second high pressure oil source 27, so that the high pressure oil in the third control chamber 24 is inputted, and the buffering effect on the hydraulic stop piston 13 is improved. The rock drill body 1 is provided with a low pressure fluid channel 32 through which the low pressure oil source 11 passes, and the low pressure fluid channel 32 is in communication with a low pressure accumulator 12. The first high pressure oil source 9, the second high pressure oil source 27 and the low pressure oil source 11 can provide the required thrust force of the buffering piston or ensure the sensitive response of the reciprocating buffering piston, and at the same time ensure the alternate sliding of the impact piston 5 along the impact axis A.
[0033] Preferably, the second inner sleeve 3 and the third inner sleeve 4 form a fourth control chamber 6 with the impact piston 5, the fourth control chamber 6 is always connected to the first high pressure oil source 9, and the impact piston 5 is provided with a control end face 19 in contact with the third inner sleeve 4. The impact piston 5 is provided with the control end face 19, which plays a role of brake protection. The impact piston 5 includes a first piston portion having a first diameter and a second piston portion having a second diameter greater than the first diameter, and the control end face 19 connects the first and second piston portions and is inclined relative to the displacement axis. The control end face 19 can be replaced by a circular arc face, an inclined face and the like, which can play the same brake effect. When the control end face 19 exceeds a predetermined position, the stepped position of the impact piston 5 enters the fourth control chamber 6, and the piston brake is opened to avoid the piston from impacting the internal parts of the sleeve. The fourth control chamber 6 plays a control role in the horizontal area between the control end face 19 and the second inner sleeve 3. When the control end face 19 enters the horizontal area, the horizontal area forms a blind cavity to brake the impact piston 5.
[0034] Preferably, the third inner sleeve 4 and the impact piston 5 form a fifth control chamber 7, the third inner sleeve 4 is provided with a reversing valve 8 for switching the high pressure and low pressure of the chamber 7 to provide the impact force of the impact piston 5 or not to provide the impact force, and the reversing valve 8 is connected to the fifth control chamber 7. The reversing valve 8 is also in communication with the high pressure accumulator 10. The reversing valve 8 is installed inside the rock drill body 1 along the impact axis A, and is in clearance fit with the third inner sleeve 4, can slide along the impact axis A, and can control the alternate connection of the oil pressure of the rear end face of the impact piston 5 to the high pressure fluid channel 23 and the low pressure fluid channel 32 according to the preset position, so as to realize the switching of the impact stroke and the return stroke of the impact piston 5.
[0035] Preferably, the front end of the hydraulic stop piston 13 is provided with a stop sleeve 20 to protect the hydraulic stop piston 13 and prolong the service life of the hydraulic stop piston 13, and the front end of the hydraulic stop piston 13 is provided with a support surface 18 supporting the stop sleeve 20.
[0036] Push stroke constraint: during the impact process of the shank 15, the first high-pressure oil source 9 supplies oil to the second control chamber 22 to provide a pushing force to move the second control surface 28 forward, which causes the hydraulic stop piston 13 to always resist the stop sleeve 20, and the stop sleeve 20 always resists the shank 15, and the shank 15, the stop sleeve 20 and the hydraulic stop piston 13 that are always in a state of resistance, after the shank 15 moves forward due to the impact of the impact piston 5, due to the movement of the shank 15 and the pushing force acting on the second control surface 28, the stop sleeve 20 and the hydraulic stop piston 13 also move forward to always resist the shank 15, and are always ready to absorb the impact energy of the rebound after impacting the rock surface. When the hydraulic stop piston 13 moves forward by a predetermined stroke A, the first control port 25 communicates with the second control chamber 22, and at this time the first control chamber 30 communicates with the second control chamber 22, and the oil of the first high-pressure oil source 9 flows from the second control chamber 22 to the first control chamber 30 along the first communication channel 16, so that the first high-pressure oil source 9 realizes the constraint of the push stroke of the hydraulic stop piston 13 through the first control surface 31.
[0037] Buffer stroke constraint: when the shank 15 retreats and impacts the stop sleeve 20 and the hydraulic stop piston 13, the hydraulic stop piston 13 moves backward to realize energy absorption and protect internal parts. During the backward movement of the hydraulic stop piston 13, the first control port 25 is disconnected from the second control chamber 22, and after retreating by a predetermined distance D, the second control port 35 communicates with the high-pressure cavity 38 and the third connecting channel 29, and the high-pressure oil enters the third control chamber 24, so that the third control surface 21 brakes the hydraulic buffer piston to move backward under the action of high-pressure oil.
[0038] The hydraulic rock drill with the hydraulic stop piston is provided with the buffer of the first control chamber 30, the second control chamber 22 and the third control chamber 24 of the hydraulic stop piston 13, so as to provide the timely response advancing force, absorb the impact energy in the rebound process of the drill tail 15, and play the continuous and smooth buffer protection role; meanwhile, the hydraulic stop piston 13 provides the proper advancing force along with the impact piston 5, so as to ensure that the drill tail impact surface 17 is stable at the preset position when retreating, ensure the consistency of the relative displacement of the impact piston 5 to hammer the drill tail 15 each time, thereby guaranteeing the stability of the rock drill frequency, and solving the technical problem that the rebound energy after the drill impacts the rock in the prior art cannot be completely absorbed, thereby causing the damage of the internal parts of the rock drill.
[0039] The preferred embodiments of the utility model are described above only, and are not used for limiting the utility model, and the utility model can have various changes and changes for the person skilled in the art. Any modification, equivalent replacement, improvement and the like within the spirit and principle of the utility model should be included in the protection scope of the utility model.
Claims
1. A hydraulic rock drill equipped with a hydraulic stop piston, characterized in that, The device includes a rock drill body (1), a sleeve assembly, an impact piston (5), a hydraulic stop piston (13), and a drill bit (15). The sleeve assembly is installed inside the rock drill body (1), the hydraulic stop piston (13) is installed inside the sleeve assembly, the impact piston (5) passes through the hydraulic stop piston (13), and the drill bit (15) is installed inside the rock drill body (1) and located at the front end of the hydraulic stop piston (13). A first control chamber (30), a second control chamber (22), and a third control chamber (24) for buffering are formed between the hydraulic stop piston (13) and the sleeve assembly, and a lubrication chamber (14) is formed between the impact piston (5) and the drill bit (15).
2. The hydraulic rock drill with a hydraulic stop piston according to claim 1, characterized in that, The sleeve assembly includes a first inner sleeve (2), a second inner sleeve (3), and a third inner sleeve (4) that are sequentially connected from the drill bit (15) to the inside of the rock drill body (1). The hydraulic stop piston (13) and the first inner sleeve (2) form the first control chamber (30). The hydraulic stop piston (13), the first inner sleeve (2), and the second inner sleeve (3) together form the second control chamber (22). The rear end face of the hydraulic stop piston (13) and the second inner sleeve (3) form the third control chamber (24).
3. The hydraulic rock drill with a hydraulic stop piston according to claim 2, characterized in that, The hydraulic stop piston (13) is provided with a first connection channel (16). When the drill bit (15) is in an impact state, the first connection channel (16) is connected to the first control chamber (30) and the second control chamber (22). The second control chamber (22) is used to connect to the first high-pressure oil source (9).
4. The hydraulic rock drill with a hydraulic stop piston according to claim 2, characterized in that, The hydraulic stop piston (13) is provided with a connected signal channel (37) and a control channel. The control channel is connected to the third control chamber (24). The first inner sleeve (2) is provided with an annular groove (34). The annular groove (34) is used to connect to the low-pressure oil source (11). When the hydraulic stop piston (13) is in the neutral position, the signal channel (37) is connected to the annular groove (34).
5. The hydraulic rock drill with a hydraulic stop piston according to claim 2, characterized in that, A fourth control chamber (6) is formed between the second inner sleeve (3), the third inner sleeve (4) and the impact piston (5). The fourth control chamber (6) is connected to the first high-pressure oil source (9). The impact piston (5) is provided with a control end face (19) that contacts the third inner sleeve (4).
6. The hydraulic rock drill with a hydraulic stop piston according to claim 2, characterized in that, A fifth control chamber (7) is formed between the third inner sleeve (4) and the impact piston (5). The third inner sleeve (4) is provided with a reversing valve (8). The reversing valve (8) is used to connect to the first high-pressure oil source (9) and the low-pressure oil source (11). The reversing valve (8) is connected to the fifth control chamber (7).
7. The hydraulic rock drill with a hydraulic stop piston according to claim 1, characterized in that, The front end of the hydraulic stop piston (13) is provided with a backstop bushing (20).