A damping system for a rock drill rod rebound process

Abstract

The application discloses a damping system for a rock drill rod rebound process. The application indirectly transmits fluid, guarantees normal percussion force output of the rock drill, avoids the impact of the rod directly impacting the impact piston of the hydraulic cylinder in the rod rebound process, and reduces the vibration in the rod rebound process. The implementation principle is summarized as follows: the energy of the rod rebound is first converted into kinetic energy of a transmission piston, and the impact disc is designed with special geometric dimensions to achieve a "delayed right movement" effect, so that the hydraulic cylinder impact piston has enough retracting time, and the impact of the rod and the intermediate structural member on the hydraulic cylinder impact piston is completely avoided, so that the vibration is reduced. The damping system of the application does not need an external power source, is stable in structure, and has strong engineering application.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of shock absorption of rock drill, and particularly relates to a shock absorption system for the rebound process of a rock drill rod. BACKGROUND

[0002] The rock drill is an important engineering machinery, which is often used in the fields of tunnel excavation and mine excavation, and specifically functions to drill holes and dig holes in rocks so as to place explosives in the holes for blasting the rocks.

[0003] The working principle of the rock drill is impact breaking. The reciprocating movement of the piston rod of the oil cylinder driven by hydraulic power intermittently impacts the front end face of the rod, and the rod transmits the impact force to the rock, so as to drill the rock.

[0004] When the rock drill works, two processes will produce strong vibration: one is the vibration produced in the process of the piston rod impacting the rod and the rod impacting the rock; the other is the vibration produced in the process of the rod rebounding and impacting the piston rod after the rod is rebounded by the rock. The former vibration is a necessary process for the rock drill to break the rock; the latter vibration is unnecessary and should be reduced.

[0005] The difficulty lies in that the process of the rod impacting the rock and the process of the rod rebounding are almost completed at the same time, and the time difference between the two actions is very short, which leads to the fact that the impact piston of the hydraulic cylinder has not enough time to retreat, so the rod rebounding process almost inevitably rebounds and impacts the impact piston, thereby producing vibration. This vibration is difficult to avoid, and in view of this difficulty, there are few researches on the shock absorption of the rod rebounding process in the industry. In a small number of related researches, there are a small number of external pneumatic shock absorption systems or external oil pressure shock absorption systems. These methods have certain disadvantages, for example, they increase the external power source, making the equipment more complex; the external independent shock absorption system has adaptability problems with the working process of the rock drill. SUMMARY

[0006] In order to solve the problems and needs in the background art, the present application provides a shock absorption system for the rebound process of a rock drill rod, and the shock absorption system of the present application relies on the self-circulating flow of the built-in fluid.

[0007] The technical scheme of the present application is:

[0008] The present application comprises a shell outer cylinder, an impact module, a buffer module, a striking device and a drill rod; the impact module and the drill rod are respectively arranged at two ends in the shell outer cylinder, the buffer module and the striking device are arranged in the shell outer cylinder, the buffer module is arranged close to the impact module and connected with the impact module, the striking device is arranged close to the drill rod, the impact module, the striking device and the drill rod are slidable in the shell outer cylinder, the buffer module is fixedly installed in the shell outer cylinder, and the impact module and the buffer module and the buffer module and the striking device are filled with transmission fluid.

[0009] The impact module comprises an impact disc, a transmission piston and an impact piston; the impact disc is sealably and slidably arranged at one end of the shell outer cylinder, one end of the transmission piston is sealably and slidably arranged in the impact disc, the other end of the transmission piston extends inwardly and is sealably and slidably arranged in the buffer module, and the impact piston is slidably arranged in the shell outer cylinder at the outer end of the impact disc.

[0010] A plurality of air holes are arranged at the circumferential side of the shell outer cylinder between the impact piston and the impact disc.

[0011] The transmission piston comprises a piston sleeve, a right end head, a left end head and a piston rod, the right end head and the left end head are connected through the piston rod, the outer diameter of the right end head is larger than that of the left end head, the left end head is sleeved with the piston sleeve, so that the transmission piston is dumbbell-shaped, and the outer diameter of the right end head is equal to that of the piston sleeve.

[0012] The buffer module comprises a shell ring, a shell inner cylinder, a first one-way valve group, a second one-way valve group, a third one-way valve group and a fourth one-way valve group.

[0013] The shell inner cylinder is fixedly installed in the shell outer cylinder through the shell ring, a cavity between the shell outer cylinder, the shell inner cylinder, the shell ring and the striking device is recorded as a fourth fluid cavity, and a cavity between the shell outer cylinder, the shell inner cylinder, the shell ring and the impact module is recorded as a first fluid cavity; an end of the impact module is sealably and slidably arranged in the shell inner cylinder, the striking device is coaxially arranged with the shell inner cylinder, a part of the striking device is sealably and slidably arranged in the shell inner cylinder, and the remaining part of the striking device is sealably and slidably arranged in the shell outer cylinder.

[0014] The chamber between the inner cylinder of the housing and the impact module is designated as the second fluid cavity, and the chamber between the inner cylinder of the housing and the impact device is designated as the third fluid cavity. All four fluid cavities (first, second, third, and fourth) are filled with a transmission fluid. A first one-way valve assembly is installed on the end face of the inner cylinder where the impact module is located, allowing the transmission fluid in the first fluid cavity to flow unidirectionally to the second fluid cavity. A second one-way valve assembly is also installed on the outer circumferential side of the inner cylinder near the impact module, allowing the transmission fluid in the second fluid cavity to flow unidirectionally to the first fluid cavity. A third one-way valve assembly is installed in the housing ring ribs, allowing the transmission fluid in the first fluid cavity to flow unidirectionally to the fourth fluid cavity. A fourth one-way valve assembly is also installed in the housing ring ribs, allowing the transmission fluid in the fourth fluid cavity to flow unidirectionally to the third fluid cavity.

[0015] When the end face of the impact module contacts the inner end face of the inner cylinder of the housing, the position of the impact module on the circumferential side of the inner cylinder of the housing does not coincide with the position of the second one-way valve group, so that the second one-way valve group is in an openable state.

[0016] The positions of each check valve in the third check valve group correspond one-to-one with those in the fourth check valve group, and the control direction of each check valve in the third check valve group is perpendicular to that of the corresponding check valve in the fourth check valve group. When the third check valve group is in the open state, it controls the state of the fourth check valve group, so that the fourth check valve group is in the closed state.

[0017] The contact surface between the transmission piston and the buffer module is set as an arc-shaped concave surface, so that when the end face of the transmission piston and the end face of the buffer module are in contact, an arc-shaped gap is formed between them.

[0018] A chamfer is provided on the end between the transmission piston and the buffer module, and a chamfer is also provided on the inner circumferential side surface between the buffer module and the end of the transmission piston, so that a conical gap and an annular gap are formed between the buffer module and the end of the transmission piston in sequence; the transmission fluid in the first fluid cavity also flows to the second fluid cavity in sequence through the annular gap, the conical gap and the arc gap between the buffer module and the transmission piston.

[0019] The impact device includes an impact disk and an annular magnet. The impact disk is composed of a first connecting post and a second connecting post connected coaxially in sequence. The diameter of the first connecting post is smaller than the diameter of the second connecting post. The first connecting post is slidably and sealably disposed in the buffer module. The second connecting post is slidably and sealably disposed in the outer cylinder of the housing. An annular magnet is installed in the end face of the second connecting post near the buffer module. The annular magnet is disposed near the first connecting post.

[0020] The beneficial effects of this invention are as follows:

[0021] (I) The present invention is free from external power source;

[0022] (II) The present invention does not affect the power transmission of the piston rod / rods to hit the rock;

[0023] (III) The present invention avoids the impact of the hydraulic cylinder piston rod during the process of the rod rebound, and reduces the system vibration. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a whole structure diagram.

[0025] Figure 2 is a front view of the sectional view.

[0026] Figure 3 is a shell structure diagram.

[0027] Figure 4 is a valve core structure diagram.

[0028] Figure 5 is a shock piston structure diagram.

[0029] Figure 6 is a piston sleeve sectional view.

[0030] Figure 7 is a cavity distribution diagram.

[0031] Figure 8 is a local enlarged view of the piston sleeve in the limit position state.

[0032] Figure 9 is a running principle diagram (I).

[0033] Figure 10 is a running principle diagram (II).

[0034] Figure 11 is a running principle diagram (III).

[0035] Figure 12 is a running principle diagram (IV).

[0036] Figure 13 is an equal volume flow principle diagram.

[0037] Figure 14 is a running principle diagram (V).

[0038] Figure 15 is a shock absorption principle diagram.

[0039] Figure 16 is a running principle diagram (VI).

[0040] Fig. 1: 1 housing; 2 impact disc; 3 transmission piston; 4 piston sleeve; 5 impact disc; 6 ring magnet; 7 impact piston; 8 drill rod; 9 valve core; 11 housing outer cylinder; 12 housing ring rib; 13 housing inner cylinder; 14 vent hole; 21 impact device; 22 air groove; 23 arc concave; 24 arc gap; 25 conical surface gap; 26 circular ring gap; A first one-way valve group; B second one-way valve group; C third one-way valve group; D fourth one-way valve group; S1 first fluid cavity; S2 second fluid cavity; S3 third fluid cavity; S4 fourth fluid cavity. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical scheme and advantages of the present application more clear, the following will be described in detail in combination with the drawings and examples. It should be understood that the examples described herein are only used to explain the present application and are not limited to the present application.

[0042] The present application discloses a damping system for the rebound process of a drill rod of a rock drill, as shown in Figures 1 to 16 for the preferred examples of the present application.

[0043] The damping system comprises a housing outer cylinder 11, an impact module, a buffer module, an impact device 21 and a drill rod 8. The impact module and the drill rod 8 are respectively arranged at the two ends in the housing outer cylinder 11. The buffer module and the impact device 21 are arranged in the housing outer cylinder 11. The buffer module is arranged close to the impact module and is connected to the impact module. The impact device 21 is arranged close to the drill rod 8. The impact device receives the power transmitted by the transmission fluid and transmits it to the drill rod 8. The drill rod 8 is the final output mechanism of the rock drill and is the final execution mechanism of the impact force. Figure 1 The end surface of the drill rod 8 is provided with some grooves, which balance the internal and external pressure difference. The impact module, the impact device 21 and the drill rod 8 are slidable in the housing outer cylinder 11, and the impact device 21 is sealably slidable in the housing outer cylinder 11. The buffer module is fixedly installed in the housing outer cylinder 11. The impact module and the buffer module are filled with transmission fluid, and the buffer module and the impact device 21 are also filled with transmission fluid. The transmission fluid is a low-viscosity, light-weight and incompressible fluid.

[0044] The impact module comprises an impact disc 2, a transmission piston 3, a piston sleeve 4 and an impact piston 7. The impact disc 2 is sealably and slidably arranged at one end of the housing outer cylinder 11. The inner wall of the housing outer cylinder 11 is a smooth inner wall, which can be sealably and slidably arranged with other structures. The middle part of the impact disc 2 is provided with an axial through hole, and the inner wall of the through hole is smooth. The diameter of the through hole is equal to the diameter of the right end of the transmission piston 3. Figure 2The transmission piston 3 is arranged in the impact disc 2 in a sealable sliding manner at one end, and is provided with a piston sleeve 4 at the other end and extends inwardly to be arranged in the shell inner cylinder 13 of the buffer module in a sealable sliding manner, and the impact piston 7 is arranged in the shell outer cylinder 11 at the outer end of the impact disc 2 in a slidable manner, and the impact piston 7 is the piston rod of the hydraulic cylinder and is the source of the impact force during the operation of the rock drill. Figure 1 The shell outer cylinder 11 is provided with a plurality of air vents 14 on the circumferential side between the impact piston and the impact disc 2, which are arranged at intervals along the circumference and are used to balance the air pressure and avoid the influence of the air pressure difference. After the impact piston 7 impacts the impact disc 2 inwardly, the impact disc 2 and the transmission piston 3 are driven to slide inwardly.

[0045] As shown in Figure 5 , the impact disc 2 is in the shape of a circular ring body and is installed in the shell 1, specifically in the shell outer cylinder 11, close to the right side. The outer wall of the impact disc 2 is smooth and has an outer diameter equal to the inner diameter of the shell outer cylinder 11, so that the impact disc 2 can slide relative to the shell outer cylinder 11 in a sealed manner. The right end surface of the impact disc is provided with air grooves, including a diffuser air groove and a ring air groove, which are communicated with each other, and the air grooves are used to balance the pressure and avoid the influence of the air pressure difference. The impact disc 2 is used to bear the impact force of the impact piston 7, slide leftward, and press the transmission fluid leftward; in this process, the impact disc 2 slides in the shell outer cylinder 11 in a sealed manner, and the right end of the transmission piston 3 also slides in the through hole of the impact disc 2 in a sealed manner. Due to the air grooves Figure 5 and the air vents 14 Figure 3 , the internal air pressure is always balanced with the external air pressure during the movement of the impact disc, avoiding the influence of the air pressure difference.

[0046] As shown in Figure 2 , the transmission piston 3 is in the shape of a dumbbell, with the right end being the thickest, the middle part being the thinnest, and the left end being moderate. The outer surface of the transmission piston 3 is smooth everywhere. In particular, the right end of the transmission piston 3 penetrates into the axial through hole of the impact disc 2, and the outer diameter is equal to the inner diameter of the central hole of the impact disc 2, and the two can slide relative to each other in a sealed manner. In particular, the middle section of the transmission piston 3 is an elongated section, and the diameter of the middle section of the transmission piston is slightly smaller than the diameter of the circular through hole of the right end surface of the shell inner cylinder 13. In particular, the diameter of the axial through hole of the impact disc 2 is equal to the inner diameter of the shell inner cylinder 13, and also equal to the outer diameter of the right end of the transmission piston 3, and also equal to the outer diameter of the piston sleeve 4.

[0047] The buffer module includes a shell ring rib 12, a shell inner cylinder 13, a first one-way valve group A, a second one-way valve group B, a third one-way valve group C, and a fourth one-way valve group D;

[0048] The inner cylinder 13 is made of metal and is fixedly installed inside the outer cylinder 11 by a shell ring rib 12. The outer cylinder 11 and the inner cylinder 13 are spatially coaxial. The length of the outer cylinder 11 is much greater than the length of the inner cylinder 13. The shell ring rib 12 is located at a relatively midpoint along the length of both the outer cylinder 11 and the inner cylinder 13. The inner wall of the inner cylinder 13 is a smooth inner wall, allowing for sealed sliding with other structural components. The left end face of the inner cylinder 13 is completely open, while the right end face is partially closed. Figure 3 A through hole and a corresponding 45-degree chamfer are provided at the center axis of the right end face. The inner walls are smooth. The diameter of the through hole is much smaller than the inner diameter of the inner cylinder 13 of the shell, and slightly larger than the piston rod diameter of the transmission piston 3. Figure 2 The shell ring rib 12 is circular in shape and is used to fix and connect the outer shell cylinder 11 and the inner shell cylinder 13. The left and right end faces of the shell ring rib 12 are perpendicular to the axis of the shell 1. In a specific implementation, the outer shell cylinder 11, the shell ring rib 12, and the inner shell cylinder 13 together form the shell 1, making the shell 1 a composite structure with a double-layered cylindrical cavity, such as... Figure 3 (a) and Figure 3 As shown in (b). The housing 1 serves as the mounting reference for the entire structure, and all structural components are installed inside the housing 1. The housing 1 is made of carbon steel.

[0049] The cavity between the outer shell 11, the inner shell 13, the shell ring rib 12, and the impact disk 5 of the impact device 21 is designated as the fourth fluid cavity S4. The cavity between the outer shell 11, the inner shell 13, the shell ring rib 12, and the transmission piston 3 of the impact module is designated as the first fluid cavity S1. One end of the transmission piston 3 of the impact module is always slidably and sealably disposed within the inner shell 13. A step is provided at one end of the inner shell 13 to limit the return of the transmission piston 3. Figure 1 As shown, this allows the transmission piston 3 to be in the right limit position within the inner cylinder 13 of the housing. The impact disc 5 of the impact device 21 is coaxially arranged with the inner cylinder 13 of the housing. A portion of the impact disc 5 of the impact device 21 is always slidably and sealably disposed within the inner cylinder 13 of the housing, while the remaining portion of the impact disc 5 of the impact device 21 is slidably and sealably disposed within the outer cylinder 11 of the housing.

[0050] The chamber between the shell inner cylinder 13 and the transmission piston 3 of the impact module in the shell inner cylinder 13 is recorded as the second fluid cavity S2, and the chamber between the shell inner cylinder 13 and the impact disc 5 of the impact device 21 in the shell inner cylinder 13 is recorded as the third fluid cavity S3. The first fluid cavity S1, the second fluid cavity S2, the third fluid cavity S3 and the fourth fluid cavity S4 are all filled with transmission fluid, and other components or positions in the system are not filled with transmission fluid. The end face of the transmission piston 3 of the impact module is provided with a first one-way valve group A, and the transmission fluid in the first fluid cavity S1 is unidirectionally communicated to the second fluid cavity S2 through the first one-way valve group A. The outer circumferential side of the shell inner cylinder 13 close to one end of the impact module is also provided with a second one-way valve group B, and the transmission fluid in the second fluid cavity S2 is unidirectionally communicated to the first fluid cavity S1 through the second one-way valve group B. The third one-way valve group C is installed in the shell ring rib 12, so that the transmission fluid in the first fluid cavity S1 is unidirectionally communicated to the fourth fluid cavity S4 through the third one-way valve group C. The fourth one-way valve group D is also installed in the shell ring rib 12, so that the transmission fluid in the fourth fluid cavity S4 is unidirectionally communicated to the third fluid cavity S3 through the fourth one-way valve group D.

[0051] The first one-way valve group A, the second one-way valve group B, the third one-way valve group C and the fourth one-way valve group D are all composed of a plurality of one-way valves, and the plurality of one-way valves are installed in the shell ring rib 12 or the shell inner cylinder 13 at intervals along the circumference. Each one-way valve is composed of a valve core 9 and a spring, and the spring is sleeved outside the valve core 9. A special-shaped hole is formed in the shell ring rib 12 or the shell inner cylinder 13, and the inner wall of the special-shaped hole is smooth. The special-shaped hole is used for accommodating and assembling the one-way valve core, and the special-shaped hole serves as the installation hole of the one-way valve core and the spring. The structure of the valve core 9 is shown in Figure 4 The valve core 9 includes a sealing end and a through end. The sealing end is a plugging structure with a 45-degree chamfer, which can be completely matched with the chamfer at the corresponding position of the special-shaped hole to realize sealing. The through end is a hollow cylindrical cavity structure, and some through holes are arranged around the cylinder.

[0052] When the end face of one end of the transmission piston 3 of the impact module is in contact with the inner end face of the shell inner cylinder 13, the position of the transmission piston 3 of the impact module on the circumferential side of the shell inner cylinder 13 does not coincide with the position of the second one-way valve group B, so that the second one-way valve group B is in an openable state. When the end head of the transmission piston 3 moves to the left, the special-shaped hole installed with the second one-way valve group B is blocked by the end head of the transmission piston 3, so that the second one-way valve group B is always closed.

[0053] The positions of each one-way valve in the third one-way valve group C correspond to the positions of each one-way valve in the fourth one-way valve group D, that is, the third one-way valve group C and the fourth one-way valve group D are installed in pairs. The control direction of each one-way valve in the third one-way valve group C is perpendicular to the control direction of the corresponding one-way valve in the fourth one-way valve group D. The conduction direction of each one-way valve in the third one-way valve group C is parallel to the axial direction, that is, the conduction direction of each one-way valve in the fourth one-way valve group D is perpendicular to the axial direction. When the third one-way valve group C is in an open state, the third one-way valve group C controls the state of the fourth one-way valve group D, so that the fourth one-way valve group D is in a closed state. The on-off of the third one-way valve group C is not affected by the on-off of the fourth one-way valve group D, that is, the conduction of the third one-way valve group C is based on the pressure of the first fluid cavity S1 being greater than the pressure of the fourth fluid cavity S4, but the precondition for the conduction of the fourth one-way valve group D is that the third one-way valve group C is closed.

[0054] The shape of the piston sleeve 4 is a horizontal cylinder, the outer surface is smooth Figure 6 The diameter of the piston sleeve 4 is equal to the inner diameter of the shell inner cylinder 13, and the two can relatively seal and slide. The left end surface of the piston sleeve 4 is a circular plane, the contact end surface between the piston sleeve 4 and the shell inner cylinder 13 of the buffer module is provided as an arc-shaped concave surface 23 (that is, the right end surface is an arc-shaped concave surface), and the right end surface is not blocked. The inside of the piston sleeve is provided with a cavity to facilitate assembly with the left end head of the transmission piston 3, so that when the end surface of the transmission piston 3 is in contact with the end surface of the shell inner cylinder 13 of the buffer module, when the transmission piston 3 is in the right limit position Figure 14 ), a certain gap can be reserved at the arc-shaped end surface, that is, an arc-shaped gap 24 is formed between the two, and a certain amount of transmission fluid can be stored in the arc-shaped gap, so as to avoid the phenomenon of "delay" at the moment of starting the transmission piston.

[0055] A chamfer is provided on the end head between the transmission piston 3 and the shell inner cylinder 13 of the buffer module, and a chamfer is also provided on the inner circumferential side between the end head of the transmission piston 3 and the shell inner cylinder 13 of the buffer module, that is, the shape of the left end head is special Figure 2 After the transmission piston 3 and the piston sleeve 4 are assembled, they are installed into the shell inner cylinder 13, and after assembly, the shell inner cylinder 13 of the buffer module and the end head of the transmission piston 3 form a conical gap 25 and a circular ring gap 26 in sequence; the transmission fluid in the first fluid cavity S1 also flows to the second fluid cavity S2 through the circular ring gap 26, the conical gap 25 and the arc-shaped gap 24 between the shell inner cylinder 13 of the buffer module and the transmission piston 3 in sequence. The conical gap 25 has two functions: 1. buffering effect, when the transmission piston moves to the right to approach the limit position, the gap gradually decreases, the oil flow rate gradually decreases, and the buffering effect is achieved; 2. rapid starting effect, when the transmission piston starts from the right limit position, a part of the oil can quickly flow through the gap, so as to avoid the phenomenon of "delay" at the moment of starting the transmission piston.

[0056] The impact device 21 comprises an impact disc 5 and a ring magnet 6; the impact disc 5 is composed of a first connecting column and a second connecting column which are coaxially connected in sequence, the diameter of the first connecting column is smaller than the diameter of the second connecting column, that is, the overall shape of the impact disc 5 is a boss shape. The diameter of the first connecting column is equal to the inner diameter of the inner cylinder 13 of the shell, and the diameter of the second connecting column is equal to the inner diameter of the outer cylinder 11 of the shell. Since the outer surface of the impact disc 5 is smooth, the first connecting column can be sealingly and slidably arranged in the inner cylinder 13 of the shell of the buffer module, and the second connecting column can be sealingly and slidably arranged in the outer cylinder 11 of the shell, and a circular hole is formed in the end face of the second connecting column close to the inner cylinder 13 of the shell of the buffer module, and the ring magnet 6 is installed in the circular hole, and the ring magnet 6 is arranged close to the first connecting column, and the impact disc 5 is reset to the position abutting the left end face of the inner cylinder of the shell through the magnetic attraction between the ring magnet 6 and the left end face of the inner cylinder 13. When the impact disc 5 is located at the right limit position, that is, the second connecting column abuts the left end face of the inner cylinder 11 of the shell, at this time, the first connecting column is deep into the inner cylinder 11 of the shell, but cannot block the special-shaped hole D hole of the fourth one-way valve group D installed on the shell ring rib 12. Figure 2 )。

[0057] When the rock drill is working, there are two processes that will produce strong vibration: one is the vibration produced in the process of the piston rod impacting the drill rod and the drill rod impacting the rock; the other is the vibration of the drill rod rebounding and impacting the piston rod after the drill rod is rebounded by the rebounding action of the rock. It should be noted that the system of the present application only reduces the vibration in the process of the drill rod rebounding.

[0058] The shock absorption principle of the present application is briefly described as follows:

[0059] As shown in Figure 2 , the impact piston 7 impacts the impact disc 2 to the left, the impact disc 2 extrudes the transmission fluid in the four cavities to the left, under the fluid transmission, the impact device 21 impacts the drill rod, and finally completes the impact on the rock; at the moment of the rebound of the drill rod, through the design of the four cavities and the cooperation of the four groups of one-way valve groups, the fluid power is completely converted into the power of pushing the transmission piston 3 to the right, which makes the kinetic energy of the rebounding converted into the kinetic energy of the transmission piston in an instant, so as to give the impact piston 7 enough time to retreat, avoiding the direct impact of the impact piston by the rebounding of the drill rod, so as to reduce the vibration produced in this process.

[0060] The working process of the shock absorption function is as follows:

[0061] First step: initial state, as shown in Figure 2 .

[0062] At this time, the impact piston 7 has not been operated on the right side, and there is a certain distance between the impact piston and the impact disc 2;

[0063] At this time, the transmission piston 3 is in the right limit position, the right end of the transmission piston 3 penetrates into the inner hole of the impact disc 2, but the right end face of the transmission piston 3 does not protrude from the right end face of the impact disc 2;

[0064] At this time, the impact disc 5 is in the right limit position, that is, under the magnetic attraction of the annular magnet 6, the second cylindrical right end face of the impact disc 5 is in abutting state with the left end face of the inner cylinder 13 of the shell;

[0065] At this time, the drill rod 8 is in the original position, at this time, there is a certain gap between the drill rod 8 and the impact disc 5;

[0066] At this time, the four groups of one-way valve groups (A / B / C / D) are all in the closed state;

[0067] At this time, four cavities (S1 / S2 / S3 / S4) are formed inside the structure, as shown in Figure 7 ;

[0068] At this time, the four cavities are filled with transmission fluid.

[0069] Second step: as shown in Figure 9 . When the rock drill starts to work, the impact piston 7 runs to the left, and when the impact piston 7 hits the impact disc 2, it drives the impact disc 2 to run to the left together;

[0070] Third step: as shown in Figure 9 . After the impact disc 2 runs to the left, it squeezes the transmission fluid in the cavity S1, and the pressure in the cavity S1 increases. Under the pressure difference between the cavity S1 and the cavity S4, all the one-way valve groups C are opened, and the transmission fluid quickly flows from the S1 cavity to the S4 cavity, the pressure in the S4 cavity increases rapidly, and then drives the impact disc 5 to move to the left; when the impact disc 5 moves to the left, the pressure in the cavity S3 decreases; at the same time, under the pressure difference between the cavity S1 and the cavity S2, all the one-way valve groups A are opened, and the transmission fluid quickly flows from the S1 cavity to the S2; Therefore, the left side of the piston sleeve 4 has small pressure and the right side has large pressure, so the piston sleeve 4 drives the transmission piston 3 to quickly move to the left under the action of the pressure difference. It needs to be specially pointed out that: at the starting moment of the transmission piston 3, due to the arc-shaped concave surface Figure 6 ) arranged on the piston sleeve, the S2 cavity is not in a vacuum state Figure 8 at the starting moment, but there is a certain amount of transmission fluid in the arc-shaped gap, which helps the quick start of the transmission piston. In addition, the assembly of the transmission piston and the piston sleeve is provided with a tapered gap and a circular ring gap Figure 8 between the inner cylinder 13 of the shell, which is also conducive to the quick entry of the transmission fluid, so the starting response of the transmission piston is very fast, which avoids the "stuck" phenomenon at the starting moment.

[0071] Furthermore, since the port of check valve assembly B is blocked by the piston sleeve 4 after operation, check valve assembly B is closed (at this time, the flow direction of the transmission fluid does not support the opening of the check valve assembly). Similarly, since the valve core of check valve assembly C blocks the port of check valve assembly D after opening, forming a clamping condition, check valve assembly D is also in the closed state.

[0072] Step 4: As Figure 10 As shown. The impact piston 7 continues to strike to the left, and the impact disc 5 also continues to move rapidly to the left, with the drive piston 3 following suit. Until the impact disc 5 strikes the chisel 8 on the left, the chisel 8 strikes the rock, completing the rock-drilling work. At this moment, the impact disc 5 stops moving to the left, and the pressure in chamber S4 increases until it reaches the same level as the pressure in chamber S1; the pressure in chamber S3 also increases rapidly and reaches the same level as the pressure in chamber S2. At this point, all one-way valve groups are closed, the transmission fluid stops flowing, and the drive piston 3 and impact disc 5 stop operating. It is important to note that at this point, the impact piston has also struck its position and stopped operating, but the impact piston 7 is still in contact with the impact disc 2. It is also important to note that the piston sleeve is now located on the left side of one-way valve group B; one-way valve group B should not be blocked at this time.

[0073] Step 5: As Figure 11 As shown, after the drill rod 8 strikes the rock, it rebounds instantly, and the rebound force pushes the impact disk 5 to the right (at this time, the impact piston 7 cannot retract in time and is still in contact with the impact disk 2). The movement of the impact disk 5 to the right causes the pressure in cavities S3 and S4 to increase rapidly. The pressure in cavity S3 increases and becomes greater than the pressure in cavity S2. Under the action of the pressure difference, the piston sleeve 4 drives the transmission piston 3 to move rapidly to the right. After the transmission piston moves to the right, the pressure in cavity S3 decreases appropriately, which in turn makes the pressure in cavity S4 greater than the pressure in cavity S3. Therefore, the one-way valve group D opens under the action of the pressure difference (at this time, the one-way valve group C is closed because there is no restriction on the opening of the one-way valve group D). After the transmission piston moves to the right, the pressure in S2 increases. Since the one-way valve group A remains closed, the one-way valve group B opens under the action of the pressure difference between cavities S2 and S1, and the transmission fluid flows from cavity S2 into S1.

[0074] It is important to note that this action is completed in a very short time, and the impact piston 7 still does not have enough time to retract.

[0075] Step 6: As Figure 12 As shown, under the rebound effect, the impact disc 5 continues to move to the right, and the transmission piston 3 also moves rapidly to the right. When the transmission piston moves to the right, the transmission fluid mainly flows from cavity S2 into cavity S1 through the one-way valve group B, and a small portion of the fluid passes through the annular gap between the transmission piston 3 and the inner cylinder 13 of the housing (…). Figure 8 ) flows into cavity S1 (Figure 12 ) When the piston sleeve 4 moves to the right to cover the one-way valve group B, the one-way valve group B is closed; then, the transmission fluid in the cavity S2 can only flow into the cavity S1 through the annular gap between the transmission piston 3 and the inner cylinder 13 of the shell ( Figure 8 ) The above process, the running speed of the transmission piston 3 is from fast to slow, which is beneficial to further reduce the vibration of the system. Figure 12

[0076] Step 7: Explain the key principle of shock absorption.

[0077] In the above fifth and sixth steps, the impact disc 5 and the transmission piston 3 move to the right, although there is a flow of transmission fluid in the cavity S1, but in this short period of time, the impact disc 2 does not move, which is the most critical. The reason is that: during the movement of the transmission piston 3 to the right, the reduced fluid volume in the cavity S2 is equal to the increased volume of the cavity S1 ( Figure 12 、 Figure 13 )。

[0078] The geometric explanation is as follows:

[0079] As shown in Figure 13 , set the inner hole diameter of the impact disc 2 as d, then according to the conditions set in the previous invention (the inner hole diameter of the impact disc 2 is equal to the inner diameter of the shell inner cylinder 13), the inner diameter of the shell inner cylinder 13 is also d; at the same time, set the diameter of the middle thin section of the transmission piston rod as e. During the movement of the transmission piston 3 to the right, the left end of the transmission piston moves to the right by a distance equal to the distance of the movement of the transmission piston to the right, and set this distance as L.

[0080] Then: the fluid reduction V1 of the second fluid cavity S2 satisfies V1 = π*(d2-e2).

[0081] Similarly: the volume increase V2 of the first fluid cavity S1, V2 = π*(d2-e2).

[0082] Therefore: V1 = V2.

[0083] This shows that: the reduced fluid volume in the second fluid cavity S2 is equal to the increased volume of the first fluid cavity S1, that is, the volume flowing into the cavity S1 during the movement of the transmission piston to the right is completely used to supplement the increased volume space of S1, and the pressure value in S1 does not change during this process. Therefore, there is no additional pressure to drive the impact disc 2 to move to the right.

[0084] ​The phenomenon shown in the above process is that when the drill rod 8 is subjected to the rebound effect, the rebound energy is converted into kinetic energy of the transmission piston 3 through energy conversion, and when the transmission piston moves, the impact disc 2 realizes the effect of delayed right movement due to the special geometric size design, and the delay process gives the impact piston 7 enough time to react and retract. During the entire process, the transmission piston 3 does not hit the impact piston 7, nor does it hit the impact disc 2. Therefore, the problem of vibration is solved.

[0085] Step 8: As shown in Figure 14 , after the rebound energy is completely converted into the kinetic energy of the transmission piston 3, the rebound energy disappears, and the system damping is completed. At this time, the structural parts have not been reset, therefore, Figure 14 , the reset process is shown. After the rebound energy disappears, the impact disc 5 continues to move to the right under the magnetic attraction of the annular magnet 6 and the inner cylinder 13 of the shell, the one-way valve group D continues to be in the open state, and the transmission fluid continues to flow from the container cavity S4 to the container cavity S3. In addition, the transmission piston 3 continues to move to the right, and the piston sleeve 3 gradually moves to the right of the one-way valve group B, which has the beneficial effect that the one-way valve group B gradually transitions from the blocked state to the unblocked state. When the one-way valve group B is blocked, the one-way valve group B is closed, and the transmission fluid in the container cavity S3 only flows from the circular annular gap between the transmission piston 3 and the inner cylinder 13 of the shell to the container cavity S1. In this process, the transmission piston moves to the right at a faster speed. When the one-way valve group B is not blocked, the one-way valve group B is opened, and the transmission fluid in the container cavity S3 mainly flows into the container cavity S1 from the one-way valve group B; only a small amount of transmission fluid still flows from the circular annular gap between the transmission piston 3 and the inner cylinder 13 of the shell to the container cavity S1, which realizes the deceleration process of the transmission piston 3 Figure 15 ), which has the beneficial effect of further reducing system vibration.

[0086] Step 9: As shown in Figure 15 and Figure 16 , when the transmission piston 3 completely moves to the right limit position, the impact disc 5 continues to move to the right under the magnetic attraction of the annular magnet 6 and the inner cylinder 13 of the shell. At this time, the fluid flows from the container cavity S4 to the container cavity S3, and then flows from the container cavity S3 to the container cavity S1 through the one-way valve group B. Since the transmission piston has reached the right limit position, the increased transmission fluid in the container cavity S1 will drive the impact disc 2 to move to the right. When the impact disc 5 and the left end surface of the inner cylinder 13 of the shell are in contact, the impact disc 5 is reset, and the impact disc 2 is also reset to the initial position. The reset is completed.

[0087] It should be noted that the transmission piston does not hit the impact piston 7 during the whole movement to the right, and the impact disc 2 does not hit the impact piston 7 due to the delayed retraction. Thus, the method of the present application effectively avoids the violent impact of the drill rod on the impact piston during the rebound, and effectively reduces the system vibration.

[0088] The above embodiments are used to explain and illustrate the present application, but not to limit the present application, and any modification and change made to the present application within the spirit and protection scope of the claims of the present application, falls into the protection scope of the present application.

Claims

1. A damping system for a rock drill rod rebound process, characterized in that, The shell outer cylinder (11) is internally provided with an impact module and a drill rod (8) at two ends respectively, the buffer module and the impact device (21) are both arranged in the shell outer cylinder (11), the buffer module is arranged close to the impact module and is connected with the impact module, the impact device (21) is arranged close to the drill rod (8), the impact module, the impact device (21) and the drill rod (8) are slidable in the shell outer cylinder (11), the buffer module is fixedly installed in the shell outer cylinder (11), and the impact module and the buffer module and the buffer module and the impact device (21) are both filled with transmission fluid ； The impact module comprises an impact disc (2), a transmission piston (3) and an impact piston (7); the impact disc (2) is arranged at one end of the shell outer cylinder (11) in a sealable sliding mode, one end of the transmission piston (3) is arranged in the impact disc (2) in a sealable sliding mode, the other end of the transmission piston (3) extends inwardly and is arranged in the buffer module in a sealable sliding mode, and the impact piston (7) is arranged in the shell outer cylinder (11) at the outer end of the impact disc (2) in a sealable sliding mode; The buffer module comprises a shell ring rib (12), a shell inner cylinder (13), a first one-way valve group (A), a second one-way valve group (B), a third one-way valve group (C) and a fourth one-way valve group (D); The shell inner cylinder (13) is fixedly installed in the shell outer cylinder (11) through the shell ring rib (12), a cavity between the shell outer cylinder (11), the shell inner cylinder (13) and the shell ring rib (12) and the impact device (21) is recorded as a fourth fluid cavity (S4), and a cavity between the shell outer cylinder (11), the shell inner cylinder (13) and the shell ring rib (12) and the impact module is recorded as a first fluid cavity (S1); an end of the impact module is arranged in the shell inner cylinder (13) in a sealable sliding mode, the impact device (21) is coaxially arranged with the shell inner cylinder (13), a part of the impact device (21) is arranged in the shell inner cylinder (13) in a sealable sliding mode, and the remaining part of the impact device (21) is arranged in the shell outer cylinder (11) in a sealable sliding mode; A cavity between the shell inner cylinder (13) and the impact module in the shell inner cylinder (13) is recorded as a second fluid cavity (S2), a cavity between the shell inner cylinder (13) and the impact device (21) in the shell inner cylinder (13) is recorded as a third fluid cavity (S3), the first fluid cavity (S1), the second fluid cavity (S2), the third fluid cavity (S3) and the fourth fluid cavity (S4) are all filled with transmission fluid, a first one-way valve group (A) is installed on an end face of the shell inner cylinder (13) where the impact module is located, and the transmission fluid in the first fluid cavity (S1) is communicated with the second fluid cavity (S2) in a one-way mode through the first one-way valve group (A); a second one-way valve group (B) is further installed on the outer circumferential side of the shell inner cylinder (13) near one end of the impact module, the transmission fluid in the second fluid cavity (S2) is communicated with the first fluid cavity (S1) in a one-way mode through the second one-way valve group (B); a third one-way valve group (C) is installed in the shell ring rib (12), so that the transmission fluid in the first fluid cavity (S1) is communicated with the fourth fluid cavity (S4) in a one-way mode through the third one-way valve group (C); and a fourth one-way valve group (D) is further installed in the shell ring rib (12), so that the transmission fluid in the fourth fluid cavity (S4) is communicated with the third fluid cavity (S3) in a one-way mode through the fourth one-way valve group (D). The transmission piston (3) comprises a piston sleeve (4), a right end head, a left end head and a piston rod, the right end head and the left end head are connected through the piston rod, the outer diameter of the right end head is larger than that of the left end head, the left end head is sleeved with the piston sleeve (4), so that the shape of the transmission piston (3) is dumbbell-shaped, and the outer diameter of the right end head is equal to that of the piston sleeve; the inner diameter of the central hole of the impact disc (2), the outer diameter of the piston sleeve (4) and the inner diameter of the shell inner cylinder (13) are the same.

2. A shock absorption system for a rock drill rod rebound process according to claim 1, characterized in that, A plurality of air holes (14) are arranged on the circumferential side surface of the shell outer cylinder (11) between the impact piston (7) and the impact disc (2).

3. A shock absorption system for a rock drill rod rebound process according to claim 1, characterized in that, When the end surface of the end of the impact module is in contact with the inner end surface of the shell inner cylinder (13), the position of the impact module on the circumferential side surface of the shell inner cylinder (13) does not coincide with the position of the second one-way valve group (B), so that the second one-way valve group (B) is in an openable state.

4. A shock absorption system for a rock drill rod rebound process according to claim 1, characterized in that, The positions of each one-way valve in the third one-way valve group (C) and each one-way valve in the fourth one-way valve group (D) correspond one by one, and the control direction of each one-way valve in the third one-way valve group (C) and the corresponding one-way valve in the fourth one-way valve group (D) is perpendicular; when the third one-way valve group (C) is in an open state, the third one-way valve group (C) controls the state of the fourth one-way valve group (D), so that the fourth one-way valve group (D) is in a closed state.

5. A shock absorption system for a rock drill rod rebound process according to claim 1, characterized in that, The contact end surface between the transmission piston (3) and the buffer module is arranged as an arc-shaped concave surface (23), so that when the end surface of the transmission piston (3) is attached to the end surface of the buffer module, an arc-shaped gap (24) is formed therebetween.

6. A shock absorption system for a rock drill rod rebound process according to claim 5, characterized in that, A chamfer is arranged on the end head between the transmission piston (3) and the buffer module, and a chamfer is also arranged on the inner circumferential side surface between the buffer module and the end head of the transmission piston (3), so that a conical gap (25) and a circular ring gap (26) are sequentially formed between the buffer module and the end head of the transmission piston (3); the transmission fluid in the first fluid cavity (S1) also flows to the second fluid cavity (S2) through the circular ring gap (26), the conical gap (25) and the arc-shaped gap (24) between the buffer module and the transmission piston (3) in sequence.

7. A shock absorbing system for a rock drill rod rebound process according to claim 1, characterized in that, The impact device (21) comprises an impact disc (5) and a ring-shaped magnet (6); the impact disc (5) is composed of a first connecting column and a second connecting column which are coaxially connected in sequence, the diameter of the first connecting column is smaller than that of the second connecting column, the first connecting column is sealingly and slidably arranged in the buffer module, the second connecting column is sealingly and slidably arranged in the shell outer cylinder (11), the ring-shaped magnet (6) is installed in the end surface of the second connecting column close to the buffer module, and the ring-shaped magnet (6) is arranged close to the first connecting column.

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