Rock drill and bit cushioning device

Abstract

This utility model discloses a rock drill and its shank buffer device. The shank buffer device includes a buffer assembly, an oil inlet assembly, and an oil return assembly. The buffer assembly is sleeved on the outer periphery of the impact piston. A first end of the buffer assembly abuts against the shank, and a second end of the buffer assembly forms a buffer cavity with the rock drill housing. The oil inlet assembly is connected to the end of the buffer cavity furthest from the buffer assembly, and the oil return assembly is connected to the end of the buffer cavity closest to the buffer assembly. The oil inlet assembly includes an oil inlet pipe and a buffer pipe arranged in parallel. A one-way valve is provided on the oil inlet pipe along the oil inlet direction, and a throttle valve is provided on the buffer pipe. The buffer assembly is used to be driven to move axially and block the oil return assembly when the shank rebounds due to a rebound force. The shank buffer device provided by this utility model has a simple and efficient buffer structure, eliminates the need for complex oil inlet and return pipes, reduces the design and manufacturing difficulty of the hydraulic system, and offers high reliability and durability.

Description

Technical Field

[0001] This utility model relates to the field of rock drilling buffer technology, and in particular, to a drill bit buffer device and a rock drill using the drill bit buffer device. Background Technology

[0002] The working principle of a rock drill is mainly to use the impact piston to intermittently strike the drill bit, thereby using the drill bit to strike the rock for drilling operations. However, due to the elasticity of the drill bit and the rock when they interact, especially when the rock is not broken, the drill bit will be subjected to a great rebound force and bounce back, thus hitting the rock drill body in the opposite direction. This may not only cause severe vibration and noise, but may also damage the internal structure of the rock drill, thereby affecting the service life and reliability of the rock drill and its drilling arm.

[0003] In response, Chinese utility model patent CN215257124U provides a buffer mechanism for a hydraulic rock drill, including a housing with a buffer cylinder. Inside the housing, a drill bit, a thrust ring, and a buffer piston are installed sequentially from front to back. When the drill bit rebounds after impacting the external structure, the drill bit, which moves axially backward, impacts the thrust ring. The thrust ring then pushes the buffer piston backward, and the hydraulic fluid in the buffer chamber is gradually discharged under the pressure of the buffer piston. The buffer piston not only limits the rebound displacement of the drill bit but also mitigates the impact. It uses hydraulic fluid to absorb the impact energy, thereby achieving a buffering effect and protecting the drill bit from damage.

[0004] However, existing technologies typically require complex oil inlet channels to control the hydraulic pressure within the buffer chamber, which increases the difficulty of designing and manufacturing the hydraulic system, makes it difficult to guarantee reliability and durability, and also increases the cost of the rock drill. Utility Model Content

[0005] The present invention primarily provides a drill bit buffer device to solve the technical problems of existing rock drill buffer devices being complex in structure, high in cost, and having poor reliability and durability.

[0006] This utility model also provides a rock drill that uses the above-mentioned drill bit buffer device.

[0007] According to one aspect of the present invention, a shank buffer device is provided for buffering the rebound force received by the shank of a rock drill. The rock drill is used to perform rock drilling operations by repeatedly striking the shank with an impact piston. The shank buffer device includes a buffer assembly, an oil inlet assembly, and an oil return assembly. The buffer assembly is sleeved on the outer periphery of the impact piston and can move axially relative to the impact piston. A first end of the buffer assembly is used to abut against the shank, and a second end of the buffer assembly is used to enclose the inner cavity of the rock drill housing to form a buffer chamber. The oil inlet assembly is connected to the end of the buffer chamber away from the buffer assembly and is used to input hydraulic oil into the buffer chamber. The oil return assembly is connected to the end of the buffer chamber near the buffer assembly and is used to discharge the hydraulic oil in the buffer chamber. The oil inlet assembly includes an oil inlet pipe and a buffer pipe arranged in parallel. A one-way valve is provided on the oil inlet pipe along the oil inlet direction, and a throttle valve is provided on the buffer pipe. The buffer assembly is used to be driven to move axially and block the oil return assembly when the shank rebounds due to the rebound force.

[0008] Preferably, the buffer assembly includes a buffer piston, which includes a first segment and a second segment arranged axially. The outer wall of the first segment is used to abut against the inner wall of the housing and can be guided and slid relative to the housing axially. The outer diameter of the second segment is smaller than the outer diameter of the first segment. The second segment is used to enclose the inner wall of the housing to form a buffer cavity.

[0009] Preferably, the inner wall of the housing for sliding cooperation with the first segment is a limiting wall, the oil inlet assembly is used to connect to a preset oil inlet hole on the limiting wall at the end away from the buffer assembly, and the oil return assembly is used to connect to a preset oil return hole on the limiting wall at the end near the buffer assembly.

[0010] Preferably, the oil inlet assembly includes a plurality of first connection ports spaced apart circumferentially along the limiting wall, the plurality of first connection ports being connected one-to-one with a plurality of preset oil inlet holes on the limiting wall; the oil return assembly includes a plurality of second connection ports spaced apart circumferentially along the limiting wall, the plurality of second connection ports being connected one-to-one with a plurality of preset oil return holes on the limiting wall.

[0011] Preferably, the end of the second segment furthest from the first segment is used to be inserted into a pre-set limiting groove in the housing and guided to slide relative to the limiting groove.

[0012] Preferably, both the first segment and the second segment are circular, and the inner diameters of the first segment and the second segment are the same and adapted to the outer diameter of the impact piston.

[0013] Preferably, the buffer assembly further includes a bushing for padding between the drill bit and the buffer piston.

[0014] Preferably, the taphole buffer device further includes an accumulator disposed on the oil inlet assembly and / or the oil return assembly.

[0015] Preferably, the throttle valve is an adjustable throttle valve, which is used to adjust the flow rate according to the rock hardness.

[0016] As a second aspect, the present invention also provides a rock drill, including a housing, and an impact piston and a drill bit respectively disposed in the inner cavity of the housing. The impact piston is used to repeatedly strike the tail end of the drill bit to perform rock drilling operations through the working end of the drill bit. The rock drill also includes the aforementioned drill bit buffer device, which is disposed in the inner cavity of the housing and keeps abutting against the tail end of the drill bit. The drill bit buffer device is used to support the drill bit and buffer the rebound force received by the drill bit.

[0017] This utility model has the following beneficial effects:

[0018] The drill bit buffer device provided by this utility model maintains the liquid pressure in the buffer chamber within a preset range through the cooperation of the oil inlet component and the oil return component. This maintains a certain hydraulic thrust on the buffer component, allowing it to remain in contact with the drill bit of the rock drill, creating a supporting force on the rock surface. This ensures full contact between the drill bit and the rock surface, improving drilling efficiency. Furthermore, it can quickly restore the supporting force on the rock when the rock collapses due to impact, causing related components to suddenly move forward freely, facilitating continuous drilling operations. When the drill bit rebounds due to the rock's rebound force, it can move the buffer component to block the oil return hole of the oil return component, thus disconnecting the oil return. At this time, the buffer chamber becomes a roughly closed space, and the liquid pressure within the buffer chamber gradually increases with the gradual squeezing action of the buffer component. The drill bit rises step by step, gradually increasing the buffering force and quickly relieving the rebound force on the drill bit. Simultaneously, some hydraulic oil in the buffer chamber can flow back through a throttle valve on the buffer pipe, allowing the pressure in the buffer chamber to increase gradually and smoothly, avoiding sudden pressure changes and effectively improving the buffering effect. When the rebound force on the buffer assembly is less than the hydraulic thrust applied by the buffer chamber, the hydraulic pressure in the buffer chamber pushes the buffer assembly and drill bit forward to reset, allowing the drill bit to re-engage with the rock. During the reset process, the buffer assembly gradually disengages from the return oil hole of the return oil assembly. At this time, the hydraulic oil in the buffer chamber can return along the return oil assembly, reducing the pressure in the buffer chamber and quickly carrying away the heat generated during compression, achieving a cooling effect. Therefore, this drill bit buffering device can maintain contact with the rock under normal conditions with a relatively small pressure, and automatically increase the buffering force according to the magnitude of the drill bit's rebound in the buffer state, achieving a rapid buffering and reset effect. The overall structure is simple and efficient, requiring no complex inlet and return oil pipelines. The hydraulic system design and manufacturing difficulty is low, with high reliability and durability, thus reducing the cost of the rock drill.

[0019] In addition to the objectives, features, and advantages described above, this utility model has other objectives, features, and advantages. The present utility model will now be described in further detail with reference to the figures. Attached Figure Description

[0020] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an undue limitation of the present invention. In the drawings:

[0021] Figure 1 A schematic diagram of the assembly structure of the taphole buffer device provided in this embodiment of the utility model.

[0022] Legend:

[0023] 1000. Rock drill; 1. Chisel shank buffer device; 11. Buffer assembly; 111. Buffer piston; 1111. First section; 1112. Second section; 112. Bushing; 12. Oil inlet assembly; 121. Check valve; 122. Throttle valve; 13. Oil return assembly; 14. Accumulator;

[0024] 2. Housing; 21. Oil inlet; 22. Oil return; 23. Limiting groove; 3. Impact piston; 4. Chisel tail. Detailed Implementation

[0025] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0026] Those skilled in the art will understand that, unless specifically stated otherwise, the term "comprising" as used in this specification means the presence of the stated features, integers, steps, operations, components, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, components, components, and / or combinations thereof. It should be understood that when we say a component is "connected" to another component, it can be directly connected to the other component or connected via an intermediate component. The term "and / or" as used herein includes all or any unit and all combinations of one or more associated listed items. The terms "first" and "second," etc., in this specification and claims are used to distinguish different objects, not to describe a particular order.

[0027] like Figure 1 As shown, this embodiment of the invention provides a drill bit buffer device 1, which is installed inside a rock drill 1000 to buffer the rebound force received by the drill bit 4 of the rock drill 1000. The buffer structure is simple, efficient, low in cost, and highly reliable and durable. Further, the rock drill 1000 includes a housing 2, an impact piston 3, and a drill bit 4. The impact piston 3 and the drill bit 4 are respectively disposed in the inner cavity of the housing 2. The impact piston 3 is used to repeatedly strike the tail end of the drill bit 4 under the drive of a hydraulic system to perform rock drilling operations through the working end of the drill bit 4.

[0028] Specifically, the drill bit buffer device 1 includes a buffer assembly 11, an oil inlet assembly 12, and an oil return assembly 13. The buffer assembly 11 is sleeved on the outer periphery of the impact piston 3 and can move axially relative to the impact piston 3. The first end of the buffer assembly 11 is used to abut the tail end of the drill bit 4, and the second end of the buffer assembly 11 is used to enclose the inner cavity of the housing 2 to form a buffer cavity. The oil inlet assembly 12 is connected to the end of the buffer cavity away from the buffer assembly 11 and is used to input hydraulic oil into the buffer cavity. The oil return assembly 13 is connected to the buffer cavity near the buffer assembly. One end of 11 is connected to and used to discharge the hydraulic oil in the buffer chamber. The oil inlet assembly 12 includes an oil inlet pipe and a buffer pipe arranged in parallel. The first end of the oil inlet pipe and the first end of the buffer pipe are used to connect to the pump station. The second end of the oil inlet pipe and the second end of the buffer pipe are both connected to the buffer chamber. The oil inlet pipe is provided with a one-way valve 121 arranged along the oil inlet direction. The buffer pipe is provided with a throttle valve 122. The buffer assembly 11 is used to be driven to move axially and block the oil return assembly 13 when the drill bit 4 is subjected to a rebound force.

[0029] The drill bit buffer device 1, through the cooperation of the oil inlet assembly 12 and the oil return assembly 13, maintains the liquid pressure in the buffer chamber within a preset range, thereby maintaining a certain hydraulic thrust on the buffer assembly 11. This allows the buffer assembly 11 to maintain contact with the drill bit 4 of the rock drill, ensuring that the drill bit 4 forms a supporting force on the rock surface. This ensures sufficient contact between the drill bit 4 and the rock surface, improving drilling efficiency. Furthermore, it can quickly restore the supporting force of the drill bit 4 on the rock when the rock collapses due to impact, causing related accessories to suddenly move freely forward, facilitating continuous drilling operations. When the drill bit 4 rebounds due to the rock's rebound force, it can move the buffer assembly 11 to block the oil return hole of the oil return assembly 13, thus disconnecting the oil return. At this time, the one-way valve 121 prevents backflow, making the buffer chamber a roughly closed space. The liquid pressure in the buffer chamber can be adjusted by the gradual squeezing action of the buffer assembly 11. The pressure gradually increases, thereby gradually increasing the buffering force and quickly relieving the rebound force on the drill bit 4. At this time, some of the hydraulic oil in the buffer chamber can flow back through the throttle valve 122 on the buffer pipe, so that the pressure in the buffer chamber can be increased gradually and smoothly, avoiding sudden changes or abrupt changes in pressure, effectively improving the buffering effect. When the rebound force on the buffer assembly 11 is less than the hydraulic thrust applied by the buffer chamber, the buffer assembly 11 and the drill bit 4 can be pushed forward and reset under the hydraulic action of the buffer chamber, so that the drill bit 4 re-attaches to the rock. During the reset process, the buffer assembly 11 gradually disengages from the return oil hole of the return oil assembly 13. At this time, the hydraulic oil in the buffer chamber can return along the return oil assembly 13, reducing the pressure in the buffer chamber and quickly removing the heat generated in the buffer chamber during compression, achieving a cooling effect. Therefore, the drill bit buffer device 1 can drive the drill bit 4 to keep it in contact with the rock under normal conditions with a small pressure. Under buffer conditions, the buffering force automatically increases with the size of the rebound action of the drill bit 4, so as to achieve the effect of rapid buffering and reset. The overall structure is simple and efficient, and there is no need to set up complicated oil inlet and return pipelines. The hydraulic system is less difficult to design and manufacture, and has strong reliability and durability, thereby reducing the cost of the rock drill 1000.

[0030] Preferably, the buffer assembly 11 includes a buffer piston 111, which includes a first segment 1111 and a second segment 1112 arranged axially. The second segment 1112 is located at the end of the first segment 1111 away from the shank 4. The outer wall of the first segment 1111 is used to abut against the inner wall of the housing 2 and can slide axially relative to the housing 2. That is, the outer diameter of the first segment 1111 is adapted to the inner diameter of the inner cavity of the housing 2 so that the first segment 1111 and the inner wall of the housing 2 fit tightly. The outer diameter of the second segment 1112 is smaller than the outer diameter of the first segment 1111 so as to form a receiving groove between the second segment 1112 and the first segment 1111. The receiving groove is used to enclose the buffer cavity with the inner wall of the housing 2.

[0031] The buffer piston 111, through the cooperation of the first segment 1111 and the second segment 1112, can not only form the buffer cavity together with the housing 2, but also fit tightly against the housing 2 to achieve guidance and limitation. The annular flange on the first segment 1111 protruding relative to the second segment 1112 can bear the hydraulic force of the buffer cavity, ensuring uniform and stable force distribution.

[0032] Preferably, the inner wall of the housing 2 for sliding engagement with the first segment 1111 is configured as a limiting wall. The oil inlet assembly 12 is connected to a pre-set oil inlet hole 21 on the limiting wall at the end away from the buffer assembly 11, and the oil return assembly 13 is connected to a pre-set oil return hole 22 on the limiting wall at the end near the buffer assembly 11. By providing the oil inlet hole 21 and the oil return hole 22 on the housing 2, when the buffer piston 111 slides axially, the first segment 1111 can quickly block or open the oil return hole 22, thereby achieving rapid switching of the hydraulic flow path.

[0033] Furthermore, the oil inlet assembly 12 includes a plurality of first connection ports spaced apart circumferentially along the limiting wall, each first connection port being connected to a plurality of pre-set oil inlet holes 21 on the limiting wall; the oil return assembly 13 includes a plurality of second connection ports spaced apart circumferentially along the limiting wall, each second connection port being connected to a plurality of pre-set oil return holes 22 on the limiting wall. The oil inlet and outlet of the buffer chamber are achieved through the cooperation of the plurality of oil inlet holes 21 and the plurality of oil return holes 22, ensuring that the hydraulic force at different positions along the circumference of the buffer chamber is uniform and stable, avoiding excessive or insufficient hydraulic force at local positions that could lead to uneven force on the buffer piston 111. Furthermore, the first segment 1111 of the buffer piston 111 can simultaneously block or open the plurality of oil return holes 22 during axial movement, meeting the usage requirements.

[0034] Preferably, the end of the second segment 1112 away from the first segment 1111 is used to insert into the preset limiting groove 23 of the housing 2 and guide and slide relative to the limiting groove 23. The cooperation between the second segment 1112 and the limiting groove 23 guides and limits the buffer piston 111, avoiding problems such as skewing or radial jump of the buffer piston 111 due to the squeezing of the rebound force and the force of the high pressure liquid. This effectively improves the movement accuracy and stability of the buffer piston 111, thereby improving the buffering effect.

[0035] Preferably, both the first segment 1111 and the second segment 1112 are annular, and their inner diameters are the same and adapted to the outer diameter of the impact piston 3. That is, both the first segment 1111 and the second segment 1112 can be supported and centered by the outer periphery of the impact piston 3, further improving the stability of the buffer piston 111.

[0036] Preferably, the buffer assembly 11 further includes a bushing 112, which is used to pad between the drill bit 4 and the buffer piston 111. Since the buffer piston 111 needs to fit tightly with the buffer chamber and withstand a large hydraulic force, it needs to be made of a material with high rigidity to avoid elastic deformation that could cause hydraulic oil leakage. Therefore, the bushing 112, placed between the drill bit 4 and the buffer piston 111, can be made of a material with lower rigidity. The bushing 112 provides a certain degree of elastic buffering, preventing the drill bit 4 from directly and rigidly impacting the buffer piston 111 during rebound, thus avoiding significant vibration and noise and preventing damage to both the drill bit 4 and the buffer piston 111.

[0037] Furthermore, the inner ring of the bushing 112 is provided with a clearance structure. The clearance structure can be specifically set as an inclined surface or a curved surface to reduce the contact area between the bushing 112 and the impact piston 3, so as to avoid the reciprocating motion of the impact piston 3 from generating a large amount of heat on the bushing 112 and causing the bushing 112 to wear more rapidly.

[0038] Preferably, the tappet shank buffer device 1 further includes an accumulator 14 disposed on the oil inlet assembly 12 and / or the oil return assembly 13. In this embodiment, both the oil inlet assembly 12 and the oil return assembly 13 are provided with accumulators 14. The accumulator 14 on the oil inlet assembly 12 is used to allow a portion of the hydraulic oil to enter the accumulator 14 along the throttle valve 122 to store energy when the buffer assembly 11 blocks the oil return assembly 13 and gradually squeezes the buffer chamber. During the reset process of the buffer assembly 11, the energy is released through the accumulator 14 to assist the stroke, achieving rapid reset. At the same time, it can also prevent hydraulic oil from flowing back to the pump station along the oil inlet assembly 12 and causing damage to the pump station. The accumulator 14 on the oil return assembly 13 is used to absorb the high-pressure return oil energy received by the oil return assembly 13 when the tappet shank 4 rebounds rapidly and the buffer assembly 11 has not yet blocked the oil return assembly 13, avoiding a sharp increase in return oil pressure that could damage the oil return assembly 13. It should be understood that, in other embodiments, the accumulator 14 may be provided only on the oil inlet assembly 12 or only on the oil return assembly 13, depending on actual needs.

[0039] Preferably, the throttle valve 122 is an adjustable throttle valve, which is used to adjust the flow rate according to the rock hardness. By adjusting the flow rate of the adjustable throttle valve, it can adapt to different buffer return oil pressures and different rebound forces for efficient buffering, meeting different operating environments and thus having greater applicability.

[0040] As a second aspect, the present invention also provides a rock drill 1000, including a housing 2, and an impact piston 3 and a drill bit 4 respectively disposed in the inner cavity of the housing 2. The impact piston 3 is used to repeatedly strike the tail end of the drill bit 4 to perform rock drilling operations through the working end of the drill bit 4. The rock drill 1000 also includes the aforementioned drill bit buffer device 1. The drill bit buffer device 1 is disposed in the inner cavity of the housing 2 and keeps abutting against the tail end of the drill bit 4. The drill bit buffer device 1 is used to support the drill bit 4 and buffer the rebound force received by the drill bit 4.

[0041] Because the buffer structure of the drill bit buffer device 1 is simple and efficient, there is no need to set up complex oil inlet and return lines on the rock drill 1000. This can reduce the design and manufacturing difficulty of the hydraulic system of the rock drill 1000, reduce the cost of the rock drill 1000, facilitate the miniaturization design of the rock drill 1000, and improve the reliability and durability of the rock drill 1000.

[0042] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A shank buffer device for buffering the rebound force received by the shank (4) of a rock drill, the rock drill being used to perform rock drilling operations by repeatedly striking the shank (4) with an impact piston (3), characterized in that, The taphole buffer device includes a buffer assembly (11), an oil inlet assembly (12), and an oil return assembly (13); The buffer assembly (11) is used to be sleeved on the outer periphery of the impact piston (3) and can move axially relative to the impact piston (3). The first end of the buffer assembly (11) is used to abut against the drill bit (4). The second end of the buffer assembly (11) is used to form a buffer cavity with the inner cavity of the housing (2) of the rock drill. The oil inlet assembly (12) is connected to the end of the buffer cavity away from the buffer assembly (11) and is used to input hydraulic oil into the buffer cavity. The oil return assembly (13) is connected to the end of the buffer cavity near the buffer assembly (11) and is used to discharge the hydraulic oil in the buffer cavity. The oil inlet assembly (12) includes an oil inlet pipe and a buffer pipe arranged in parallel. The oil inlet pipe is provided with a one-way valve (121) arranged along the oil inlet direction. The buffer pipe is provided with a throttle valve (122). The buffer assembly (11) is used to be driven to move axially and block the oil return assembly (13) when the drill bit (4) rebounds due to the rebound force.

2. The taphole buffer device according to claim 1, characterized in that, The buffer assembly (11) includes a buffer piston (111), which includes a first segment (1111) and a second segment (1112) arranged axially. The outer wall of the first segment (1111) is used to abut against the inner wall of the housing (2) and can be guided and slid relative to the housing (2) axially. The outer diameter of the second segment (1112) is smaller than the outer diameter of the first segment (1111), and the second segment (1112) is used to form a buffer cavity by enclosing the inner wall of the housing (2).

3. The taphole buffer device according to claim 2, characterized in that, The inner wall of the housing (2) for sliding cooperation with the first segment (1111) is set as a limiting wall. The oil inlet assembly (12) is used to connect with the oil inlet hole (21) at the end of the limiting wall away from the buffer assembly (11). The oil return assembly (13) is used to connect with the oil return hole (22) at the end of the limiting wall close to the buffer assembly (11).

4. The taphole buffer device according to claim 3, characterized in that, The oil inlet assembly (12) includes a plurality of first connection ports arranged circumferentially along the limiting wall, the plurality of first connection ports being connected one-to-one with a plurality of preset oil inlet holes (21) on the limiting wall; the oil return assembly (13) includes a plurality of second connection ports arranged circumferentially along the limiting wall, the plurality of second connection ports being connected one-to-one with a plurality of preset oil return holes (22) on the limiting wall.

5. The rod tail buffer device according to claim 2, characterized in that, The end of the second segment (1112) away from the first segment (1111) is used to be inserted into the preset limiting groove (23) of the housing (2) and guided to slide relative to the limiting groove (23).

6. The taphole buffer device according to claim 2, characterized in that, Both the first segment (1111) and the second segment (1112) are circular. The inner diameters of the first segment (1111) and the second segment (1112) are the same and are adapted to the outer diameter of the impact piston (3).

7. The taphole buffer device according to claim 2, characterized in that, The buffer assembly (11) also includes a bushing (112) for padding between the rod tip (4) and the buffer piston (111).

8. The taphole buffer device according to claim 1, characterized in that, The taphole buffer device also includes an accumulator (14) disposed on the oil inlet assembly (12) and / or the oil return assembly (13).

9. The taphole buffer device according to claim 1, characterized in that, The throttle valve (122) is an adjustable throttle valve, which is used to adjust the flow rate according to the rock hardness.

10. A rock drill, comprising a housing (2), and an impact piston (3) and a drill bit (4) respectively disposed in the inner cavity of the housing (2), the impact piston (3) being used to repeatedly strike the tail end of the drill bit (4) to perform rock drilling operations through the working end of the drill bit (4), characterized in that, The rock drill further includes a shank buffer device as described in any one of claims 1 to 9, wherein the shank buffer device is disposed in the inner cavity of the housing (2) and remains in contact with the tail end of the shank (4), and the shank buffer device is used to support the shank (4) and buffer the rebound force received by the shank (4).

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