An impact device for a rock drill

Abstract

The application discloses a rock drill impact device and a rock drill, which comprise a shell, a cylinder sleeve, a reversing valve and a piston, the piston and the reversing valve are coaxially arranged in the cylinder sleeve, the cylinder sleeve is installed in the shell, the shell is provided with an oil inlet main path and an oil return main path, the cylinder sleeve is provided with an oil inlet branch path communicated with the oil inlet main path and an oil return branch path communicated with the oil return main path, and the reversing valve is provided with an oil path, the oil path is communicated with the front end face and the rear end face of the reversing valve. The impact moving component is installed in the cylinder sleeve, the impact moving component does not directly contact the main shell, and the service life of the shell is greatly improved; the shell only bears the sheath supporting effect, the oil channel is simple, the machining difficulty is reduced, and the production efficiency and the service life of the shell are improved.

Description

Technical Field

[0001] The present application relates to the field of rock drills, and in particular to an impact device of a rock drill and a rock drill. Background Art

[0002] A rock drill is a tool used for directly mining stone. It creates blastholes in the rock formation for explosives to be placed to blast the rock apart, thereby completing stone mining or other stonework operations. A rock drill operates on the principle of impact crushing. During operation, the piston reciprocates at high frequency, continuously striking the drill adapter. Under the impact force, the sharp, wedge-shaped drill bit crushes the rock and penetrates it to a certain depth, creating an indentation. After the piston retracts, the drill bit rotates a certain angle, and the piston moves forward again, striking the drill adapter again, creating a new indentation. The fan-shaped rock between the two indentations is sheared by the horizontal force generated by the drill bit. The piston continuously strikes the drill adapter, and compressed air or water is continuously fed through the center hole of the drill bit to expel the rock debris, thus forming a circular drill hole of a certain depth.

[0003] Related technologies include a rock drill impact structure and a rock drill disclosed in the Chinese patent application with application number CN202220144770.3. The rock drill impact structure includes a housing having a cylinder bore, and a first medium channel and a second medium channel connected to the high-pressure oil chamber and the cylinder bore, a third medium channel and a fourth medium channel connected to the low-pressure oil chamber and the cylinder bore, and a fifth medium channel arranged along the length of the cylinder bore and connected to the cylinder bore at one end; and an impact piston having a third position and a fourth position. When the utility model is in use, the oil distribution valve core can reciprocate between the first position and the second position under the action of the hydraulic pump. At the same time, the oil distribution valve core can open or close the second medium channel and the fourth medium channel during the movement, controlling the corresponding part of the cylinder bore to be connected to the high-pressure oil chamber or the low-pressure oil chamber. The impact piston can quickly slide back and forth between the third position and the fourth position under the action of the hydraulic pressure, thereby improving work efficiency.

[0004] Another example is a piston buffer mechanism and rock drill disclosed in the Chinese patent application with application number CN202210059815.1, which includes a body and a buffer sleeve; the body is formed with a main liquid inlet channel and a main liquid return channel; the middle part of the buffer sleeve protrudes to form a convex ring segment, a first liquid filling chamber is formed between the body and the convex ring segment, and a second liquid filling chamber is formed between the body and the convex ring segment and the rear end face of the convex ring segment; the first liquid filling chamber is connected to the main liquid return channel, and the second liquid filling chamber is connected to the main liquid inlet channel; the buffer sleeve is formed with a first channel; when the buffer sleeve is in a first preset position, the first channel and the second liquid filling chamber are in a conducting state; when the buffer sleeve moves backward to the second preset position, the first channel and the second liquid filling chamber are in a blocked state. The present invention simplifies the structure of the buffer unit, achieves a rapid response of the buffer control, and greatly reduces the assembly difficulty and failure rate of the buffer mechanism.

[0005] In the related art of the currently disclosed hydraulic impact device, the oil passages opened on the housing are complex and the tooling is difficult, which is not conducive to improving the production efficiency and the service life of the housing. Summary of the Invention

[0006] The technical problem to be solved by the present application is to provide an impact device of a rock drill and a rock drill, wherein the impact moving parts are installed in the cylinder sleeve, and the impact moving parts do not directly contact the main shell, thereby greatly improving the life of the shell; the shell only serves to support the sleeve, the oil channel is simple, and the processing difficulty is reduced, which is conducive to improving production efficiency and the service life of the shell.

[0007] The technical solution adopted in this application is: an impact device of a rock drill, including a shell, a cylinder sleeve, a reversing valve and a piston, the piston and the reversing valve are coaxially arranged in the cylinder sleeve, the cylinder sleeve is installed in the shell, the shell is provided with an oil inlet main path and an oil return main path, the cylinder sleeve is provided with an oil inlet branch connected to the oil inlet main path, and an oil return branch connected to the oil return main path, the reversing valve is provided with an oil circuit, and the oil circuit connects the front end face and the rear end face of the reversing valve.

[0008] Compared with the prior art, the advantage of the present application is that a cylinder sleeve is added between the housing and the piston, and between the housing and the reversing valve, so that the housing and the reversing valve, which are components of the impact movement, do not directly contact the housing, greatly improving the service life of the housing. In the present application, the housing only serves as a sleeve and a support, and only one main oil inlet and one main oil return are provided to introduce oil to the cylinder sleeve. Therefore, the oil passage of the housing is simple, which reduces the difficulty of processing the housing and is conducive to improving production efficiency and the service life of the housing. The reversing valve is coaxially arranged and installed with the piston, and both the reversing valve and the piston can move axially in the cylinder sleeve. The reversing valve moves in the cylinder sleeve, and the moving reversing valve will change the connection status of the oil, realize the switching of the thrust of the rear end face of the piston, and then assist the entire movement of the piston.

[0009] In this application, the side of the piston close to the drill tool is the front, and the side of the piston away from the drill tool is the rear. The front end of the piston is connected to the drill tool, and the rear end of the piston is occasionally in contact with the reversing valve.

[0010] In this application, due to the molding process of the cylinder liner, the cylinder liner can be a non-integrated structure. The cylinder liner can be a split structure including a front cylinder liner and a rear cylinder liner. In this application, the moving parts are installed in the cylinder liner (front cylinder liner and rear cylinder liner), and the moving parts do not directly contact the shell, which greatly improves the shell life.

[0011] In some embodiments of the present application, the inner wall surface of the cylinder liner is provided with a plurality of pressure equalizing grooves, and there is a distance between two adjacent pressure equalizing grooves. The pressure equalizing groove is an annular groove coaxial with the cylinder liner.

[0012] Specifically, the pressure equalizing grooves are distributed around the piston and the reversing valve. During the entire movement of the piston, the piston contacts at least one of the pressure equalizing grooves. During the entire movement of the reversing valve, the piston contacts at least one of the pressure equalizing grooves.

[0013] Preferably, the piston is provided with 1-10 pressure equalizing grooves on its periphery, and the reversing valve is provided with 1-10 pressure equalizing grooves on its periphery, to ensure that oil support is generated on the annular surface of the moving parts, thereby reducing the influence of the hydraulic clamping force caused by the eccentricity of the moving parts due to uneven oil distribution.

[0014] In some embodiments of the present application, an oil circuit is provided on the reversing valve, and the oil circuit connects the front end face and the rear end face of the reversing valve.

[0015] Furthermore, the front end of the reversing valve has a contact surface, which contacts the piston, and a conducting groove is provided on the contact surface, which connects the oil circuit and the periphery of the reversing valve. When the reversing valve is in contact with the piston, although the structure does not specifically include a corresponding sealing structure, it is still possible that the oil cannot flow between the contact surfaces of the reversing valve during operation. Therefore, the present application additionally provides a conducting groove to ensure that the oil can flow smoothly through the conducting groove during operation, that is, the oil on the periphery of the reversing valve and the oil circuit are in a mutually conductive state.

[0016] In some embodiments of the present application, the inner wall surface of the cylinder liner is provided with a front cavity, a rear cavity, a first signal oil port, a first high-pressure oil port, a first return oil port, a second signal oil port, a second return oil port, and a second high-pressure oil port from front to back.

[0017] The front chamber is connected to the oil inlet branch, the rear chamber is connected to the oil return branch, the first and second signal oil ports are connected via an oil passage provided on the cylinder liner, the first and second high-pressure oil ports are connected to the oil inlet branch, and the first and second oil return ports are connected to the oil return branch. The main oil inlet is connected to a constant high-pressure oil supply, and the main oil return is connected to a constant low-pressure oil supply, with the return oil pressure being approximately zero.

[0018] In some embodiments of the present application, the piston is provided with an expansion section corresponding to the front cavity, the diameter of the expansion section being the largest point of the piston diameter, and the expansion section being located within the front cavity. Throughout the entire movement process of normal operation of the piston, the piston is limited by the front cavity and remains within the front cavity.

[0019] The piston is provided with a contraction section corresponding to the rear cavity. The diameter of the contraction section is smaller than the diameter of the piston adjacent to the contraction section. During the entire movement process of normal operation of the piston, the contraction section has a smaller diameter and is not restricted by the rear cavity, and can move outside the range of the rear cavity.

[0020] Specifically, in an oil-filled environment, the area of ​​the oil acting on the rear end surface of the piston is larger than the area of ​​the contraction section in the rear cavity, and the area of ​​the oil acting on the contraction section in the rear cavity is larger than the area of ​​the expansion section in the front cavity.

[0021] Since the effective area of ​​the switching oil pressure end face (rear end face) is large, the oil pressure required to achieve the same effective thrust is lower and the flow rate is larger. The lower effective oil pressure can reduce the damage to components caused by high-pressure impact to a certain extent and reduce the consumption of components.

[0022] The rear end of the piston is provided with a first signal channel and a second signal channel, respectively, connecting the piston's outer peripheral surface with its rear end surface. During normal piston operation, the first signal oil port occasionally communicates with the first signal channel. The first signal channel provides a signal indicating normal piston operation. During non-operational piston operation, the second signal oil port occasionally communicates with the first signal channel.

[0023] The rear end surface of the piston is communicated with the oil circuit of the reversing valve, and the second signal channel is communicated with the rear end of the reversing valve.

[0024] The reversing valve and piston are coaxially mounted, and the front and rear chambers of the reversing valve are alternately filled with oil to achieve directional control. The coaxial arrangement of the piston and reversing valve is simple and compact, making assembly and disassembly easier and more maintainable. The overall dimensions of this application also feature a lower center height.

[0025] In the present application, there are fewer alternating oil chambers, and the contact area of ​​such alternating oil chambers is large. In addition, due to the low pressure and high flow characteristics of such rock drills, the end face oil pressure is more stable, the mutation is smaller, and the switching movement is more stable, which reduces the possibility of negative pressure on this end face. In combination with the action of the throttle valve, the probability of negative pressure in the chamber is reduced, which reduces the possibility of cavitation in the rock drill cavity to a certain extent and extends the service life of the shell.

[0026] In some embodiments of the present application, the present application further includes a push valve assembly. Within the cylinder sleeve, a piston, a reversing valve, and a push valve assembly are sequentially arranged from front to back. The reversing valve is a cylindrical structure, and a notch is defined on the rear end of the reversing valve to accommodate the push valve assembly. During the entire movement of the piston, portions of the push valve assembly occasionally become embedded in the notch.

[0027] In some embodiments of the present application, the push valve assembly includes a primary oil distribution sleeve, a secondary oil distribution sleeve, and a push valve stem. The primary oil distribution sleeve is arranged outside the secondary oil distribution sleeve, and the secondary oil distribution sleeve is arranged outside the push valve stem.

[0028] A limit groove is provided in the cylinder liner, and the limit groove and the rear end surface of the cylinder liner inner cavity constitute the travel limit of the first-stage oil distribution sleeve. During the entire movement process of normal operation of the piston, the first-stage oil distribution sleeve at least partially moves between the limit groove and the rear end surface of the cylinder liner inner cavity.

[0029] The rear end surface of the first-stage oil distribution sleeve and the rear end surface of the cylinder liner inner cavity constitute the travel limit of the second-stage oil distribution sleeve. During the entire movement process of normal operation of the piston, the first-stage oil distribution sleeve at least partially moves between the rear end surface of the first-stage oil distribution sleeve and the rear end surface of the cylinder liner inner cavity.

[0030] Furthermore, an oil distribution ring is installed at the rear end surface of the first-stage oil distribution sleeve. The rear end surface of the oil distribution ring and the rear end surface of the cylinder liner inner cavity constitute the travel limit of the second-stage oil distribution sleeve.

[0031] A limiting cavity is provided in the secondary oil distribution sleeve, and the limiting cavity and the rear end surface of the cylinder liner inner cavity constitute a travel limit for the push valve rod. During the entire movement process of normal operation of the piston, the push valve rod at least partially moves between the limiting cavity and the rear end surface of the cylinder liner inner cavity.

[0032] During the entire movement process of the piston in normal operation, the movement stroke of the valve push rod is greater than the movement stroke of the secondary oil distribution sleeve, and the movement stroke of the secondary oil distribution sleeve is greater than the movement stroke of the primary oil distribution sleeve.

[0033] The second high-pressure oil port is communicated with the first-stage oil distribution sleeve, the second-stage oil distribution sleeve, and the rear end face of the push valve stem. The second high-pressure oil port is communicated with the rear end face of the oil distribution ring.

[0034] The first oil distribution sleeve is provided with a first channel for oil flow, connecting the inner wall and outer circumference of the first oil distribution sleeve, and a gap exists between the first and second oil distribution sleeves. The second oil distribution sleeve is provided with a second channel for oil flow, connecting the inner wall and outer circumference of the second oil distribution sleeve, and a gap exists between the second oil distribution sleeves. The first and second channels are connected to the second oil return port.

[0035] The secondary oil distribution sleeve is provided with a third channel, which connects the front end surface of the secondary oil distribution sleeve and the outer peripheral surface of the secondary oil distribution sleeve. The secondary oil distribution sleeve is provided with a fourth channel for oil to pass through; during the entire movement process of normal operation of the piston, the fourth channel is occasionally connected to the third channel.

[0036] In this application, the reversing valve performs graded braking, making the reversing braking process smoother and more efficient. The push valve assembly performs graded braking, making the reversing smoother. Different reversing braking efficiencies can be achieved through the effective area of ​​each level of the push valve assembly. It has a wide range of applications, especially for the reversing mechanism of high-power equipment.

[0037] The above embodiments can be combined arbitrarily based on the common knowledge in this field.

[0038] A rock drill includes a stepped braking impact device. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The present application will be further described in detail below with reference to the accompanying drawings and preferred embodiments. However, those skilled in the art will appreciate that these drawings are drawn only for the purpose of explaining the preferred embodiments and therefore should not be construed as limiting the scope of the present application. In addition, unless otherwise specified, the drawings are merely schematic representations of the composition or structure of the described objects and may contain exaggerated representations. The drawings are not necessarily drawn to scale.

[0040] Figure 1 This is a schematic structural diagram of the graded braking impact device of the present application;

[0041] Figure 2 This is a partial enlarged view of the pressure equalizing tank part in this application;

[0042] Figure 3 This is a schematic diagram of the structure of the piston in this application;

[0043] Figure 4 This is a structural diagram of the reversing valve in this application;

[0044] Figure 5 for Figure 4 A partial enlarged view of point A in the middle;

[0045] Figure 6 This is a schematic diagram of the stroke motion structure of the graded brake impact device of this application. Figure 1 ;

[0046] Figure 7 This is a schematic diagram of the stroke motion structure of the graded brake impact device of this application. Figure 2 ;

[0047] Figure 8 This is a schematic diagram of the stroke motion structure of the graded brake impact device of this application. Figure 3 ;

[0048] Figure 9 This is a schematic diagram of the stroke motion structure of the graded brake impact device of this application. Figure 4 ;

[0049] Figure 10 This is a schematic diagram of the structure of the return motion of the graded brake impact device of this application Figure 1 ;

[0050] Figure 11 This is a schematic diagram of the structure of the return motion of the graded brake impact device of this application Figure 2 ;

[0051] Figure 12 This is a schematic diagram of the structure of the return motion of the graded brake impact device of this application Figure 3 ;

[0052] Figure 13 This is a schematic diagram of the structure of the return motion of the graded brake impact device of this application Figure 4 ;

[0053] Figure 14 This is a schematic diagram of the structure of the return motion of the graded brake impact device of this application Figure 5 ;

[0054] Figure 15 This is a schematic diagram of the structure of the return motion of the graded brake impact device of this application Figure 6 .

[0055] The reference numerals are specifically described as follows: 1. housing; 2. cylinder liner; 3. reversing valve; 4. piston; 4a. expansion section; 4b. contraction section; 5. main oil inlet; 6. main oil return; 7. branch oil inlet; 8. branch oil return; 9. drill tool;

[0056] 10. Pressure equalizing tank; 11. Oil circuit; 12. Conducting tank; 13. First signal channel; 14. Second signal channel;

[0057] 21. Front chamber; 22. Rear chamber; 23. First signal oil port; 24. First high-pressure oil port; 25. First oil return port; 26. Second signal oil port; 27. Second oil return port; 28. Second high-pressure oil port;

[0058] 41. First-stage oil distribution sleeve; 42. Oil distribution ring; 43. Second-stage oil distribution sleeve; 44. Push valve stem; 45. Limit groove; 46. Limit cavity; 47. First channel; 48. Second channel; 49. Third channel; 40. Fourth channel. DETAILED DESCRIPTION

[0059] The present application will be described in detail below with reference to the accompanying drawings.

[0060] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0061] An impact device for a rock drill, embodiment 1 Figure 1As shown: it includes a housing 1, a cylinder sleeve 2, a reversing valve 3 and a piston 4. The piston 4 and the reversing valve 3 are coaxially arranged in the cylinder sleeve 2, and the cylinder sleeve 2 is installed in the housing 1. The cylinder sleeve 2 is added between the housing 1 and the piston 4, and between the housing 1 and the reversing valve 3, so that the housing 1 and the reversing valve 3, which are components with impact movement, do not directly contact the housing 1, greatly improving the service life of the housing 1. In this application, the housing 1 only serves as a sleeve and a support, and only one main oil inlet 5 and one main oil return 6 are provided to introduce oil into the cylinder sleeve 2. Therefore, the oil passage of the housing 1 is simple, which reduces the difficulty of processing the housing 1 and is conducive to improving production efficiency and the service life of the housing 1. The reversing valve 3 and the piston 4 are coaxially arranged and installed, and both the reversing valve 3 and the piston 4 can move axially in the cylinder sleeve 2.

[0062] The housing 1 defines a main oil inlet passage 5 and a main oil return passage 6. The cylinder liner 2 defines a branch oil inlet passage 7 communicating with the main oil inlet passage 5 and a branch oil return passage 8 communicating with the main oil return passage 6. Oil passes through the housing 1 and cylinder liner 2, coming into contact with the piston 4 and the reversing valve 3. As the reversing valve 3 moves within the cylinder liner 2, the movement of the reversing valve 3 alters the oil flow, switching the thrust applied to the rear end of the piston 4 and thereby assisting the overall movement of the piston 4.

[0063] In this application, the side of the piston 4 close to the drilling tool 9 is the front, and correspondingly, the side of the piston 4 away from the drilling tool 9 is the rear. The front end of the piston 4 is connected to the drilling tool 9, and the rear end of the piston 4 is occasionally in contact with the reversing valve 3.

[0064] In the present application, due to the molding process of the cylinder liner 2, the cylinder liner 2 may not be an integral structure, but may be a split structure including a front cylinder liner 2 and a rear cylinder liner 2. In the present application, the moving parts are installed in the cylinder liner 2 (front cylinder liner 2, rear cylinder liner 2), and the moving parts do not directly contact the housing 1, which greatly improves the life of the housing 1.

[0065] The inner wall surface of the cylinder liner 2 is provided with a plurality of pressure equalizing grooves 10 , and there is a distance between two adjacent pressure equalizing grooves 10 . The pressure equalizing grooves 10 are annular grooves coaxial with the cylinder liner 2 .

[0066] Specifically, the pressure equalizing grooves 10 are distributed around the piston 4 and the reversing valve 3. During the entire movement of the piston 4, the piston contacts at least one of the pressure equalizing grooves 10. During the entire movement of the reversing valve 3, the piston contacts at least one of the pressure equalizing grooves 10.

[0067] Preferably, the piston 4 is provided with 1-10 equalizing grooves 10 on its periphery, and the reversing valve 3 is provided with 1-10 equalizing grooves 10 on its periphery. This ensures that oil support is generated on the annular surface of the moving parts, reducing the influence of the hydraulic clamping force generated by the eccentricity of the moving parts due to uneven oil distribution.

[0068] The reversing valve 3 is provided with an oil circuit 11, which connects the front end face and the rear end face of the reversing valve 3. Furthermore, the front end of the reversing valve 3 has a contact surface, which contacts the piston 4. A conducting groove 12 is provided on the contact surface, which connects the oil circuit 11 and the periphery of the reversing valve 3. When the reversing valve 3 is in contact with the piston 4, although the structure does not intentionally have a corresponding sealing structure, it may still be the case that the oil cannot flow between the contact surfaces of the reversing valve 3 during operation. Therefore, the present application additionally provides a conducting groove 12 to ensure that the oil can flow smoothly through the conducting groove 12 during operation, that is, the oil on the periphery of the reversing valve 3 and the oil circuit 11 are in a mutually conductive state.

[0069] The inner wall surface of the cylinder liner 2 is provided with a front cavity 21, a rear cavity 22, a first signal oil port 23, a first high-pressure oil port 24, a first oil return port 25, a second signal oil port 26, a second oil return port 27, and a second high-pressure oil port 28 in sequence from front to back.

[0070] The front chamber 21 is connected to the oil return branch 8, the rear chamber 22 is connected to the oil inlet branch 7, the first signal oil port 23 and the second signal oil port 26 are connected via an oil passage provided on the cylinder liner 2, the first high-pressure oil port 24 and the second high-pressure oil port 28 are connected to the oil return branch 8, and the first oil return port 25 and the second oil return port 27 are connected to the oil inlet branch 7. The main oil inlet line 5 is connected to a constant high-pressure oil, and the main oil return line 6 is connected to a constant low-pressure oil, and the return oil pressure is approximately equal to 0.

[0071] The piston 4 is provided with an expansion section 4a corresponding to the front cavity 21. The diameter of the expansion section 4a is the largest part of the piston 4 and is located in the front cavity 21. During the entire movement process of normal operation of the piston 4, it is limited by the front cavity 21 and always stays in the front cavity 21.

[0072] The piston 4 is provided with a contraction section 4b corresponding to the rear cavity 22. The diameter of the contraction section 4b is smaller than the diameter of the piston 4 adjacent to the contraction section 4b. During the entire movement process of normal operation of the piston 4, the diameter of the contraction section 4b is smaller, and the contraction section 4b is not restricted by the rear cavity 22, and can move outside the range of the rear cavity 22.

[0073] Specifically, in an oil-filled environment, the area of ​​the oil acting on the rear end surface of the piston 4 is larger than the area of ​​the contraction section 4b in the rear cavity 22, and the area of ​​the oil acting on the contraction section 4b in the rear cavity 22 is larger than the area of ​​the expansion section 4a in the front cavity 21.

[0074] Since the effective area of ​​the switching oil pressure end face (rear end face) is large, the oil pressure required to achieve the same effective thrust is lower and the flow rate is larger. The lower effective oil pressure can reduce the damage to components caused by high-pressure impact to a certain extent and reduce the consumption of components.

[0075] The rear end of the piston 4 is provided with a first signal channel 13 and a second signal channel 14, respectively, connecting the outer circumference of the piston 4 with its rear end. During normal operation of the piston 4, the first signal oil port 23 occasionally communicates with the first signal channel 13. The first signal channel 13 provides a signal indicating the normal operation of the piston 4. When the piston 4 is in a dry state (abnormal operation), the second signal oil port 26 occasionally communicates with the first signal channel 13.

[0076] The rear end surface of the piston 4 is communicated with the oil path 11 of the reversing valve 3 , and the second signal channel 14 is communicated with the rear end of the reversing valve 3 .

[0077] The reversing valve 3 and piston 4 are coaxially arranged and installed. The front chamber and rear chamber of the reversing valve 3 are alternately oiled to achieve the movement of the reversing valve 3. The coaxial arrangement of the piston 4 and the reversing valve 3 is simple and compact, making disassembly and maintenance easier. The center height of this application is lower in terms of overall dimensions.

[0078] In the present application, there are fewer alternating oil chambers, and the contact area of ​​such alternating oil chambers is large. In addition, due to the low pressure and high flow characteristics of such rock drills, the end face oil pressure is more stable, the mutation is smaller, and the reversing movement is more stable, which reduces the possibility of negative pressure on this end face. In conjunction with the action of the throttle valve, the probability of negative pressure in the chamber is reduced, which reduces the possibility of cavitation in the rock drill cavity to a certain extent and extends the service life of the shell 1.

[0079] The rest of the content of the second embodiment is the same as that of the first embodiment.

[0080] In the second embodiment, the present application also includes a push-valve assembly. Within the cylinder liner 2, a piston 4, a reversing valve 3, and a push-valve assembly are arranged in order from front to back. The reversing valve 3 is a cylindrical structure, and a notch is defined on its rear end to accommodate the push-valve assembly. During the entire movement of the piston 4, portions of the push-valve assembly occasionally become embedded in the notch.

[0081] The push valve assembly includes a primary oil distribution sleeve 41, a secondary oil distribution sleeve 43 and a push valve rod 44. The primary oil distribution sleeve 41 is sleeved outside the secondary oil distribution sleeve 43, and the secondary oil distribution sleeve 43 is sleeved outside the push valve rod 44.

[0082] A limit groove 45 is provided in the cylinder liner 2. Together with the rear end surface of the cylinder liner 2's inner cavity, the limit groove 45 and the rear end surface of the cylinder liner 2's inner cavity constitute a travel limit for the primary oil distribution sleeve 41. Throughout the normal movement of the piston 4, the primary oil distribution sleeve 41 at least partially moves between the limit groove 45 and the rear end surface of the cylinder liner 2's inner cavity.

[0083] The rear end surface of the primary oil distribution sleeve 41 and the rear end surface of the inner cavity of the cylinder liner 2 constitute the travel limit of the secondary oil distribution sleeve 43. During the entire movement process of normal operation of the piston 4, the primary oil distribution sleeve 41 at least partially moves between the rear end surface of the primary oil distribution sleeve 41 and the rear end surface of the inner cavity of the cylinder liner 2.

[0084] Furthermore, an oil distribution ring 42 is installed at the rear end surface of the first oil distribution sleeve 41. The rear end surface of the oil distribution ring 42 and the rear end surface of the inner cavity of the cylinder liner 2 constitute the travel limit of the second oil distribution sleeve 43.

[0085] A limit cavity 46 is provided within the secondary oil distribution sleeve 43. This limit cavity 46 and the rear end surface of the cylinder liner 2 inner cavity constitute a travel limit for the valve push rod 44. Throughout the normal operation of the piston 4, the valve push rod 44 at least partially moves between the limit cavity 46 and the rear end surface of the cylinder liner 2 inner cavity.

[0086] During the entire movement process of the piston 4 in normal operation, the movement stroke of the valve push rod 44 is greater than the movement stroke of the secondary oil distribution sleeve 43 , and the movement stroke of the secondary oil distribution sleeve 43 is greater than the movement stroke of the primary oil distribution sleeve 41 .

[0087] The second high-pressure oil port 28 is communicated with the rear end surface of the first-stage oil distribution sleeve 41 , the second-stage oil distribution sleeve 43 , and the push valve stem 44 . The second high-pressure oil port 28 is communicated with the rear end surface of the oil distribution ring 42 .

[0088] The first oil distribution sleeve 41 is provided with a first passage 47 for oil flow. The first passage 47 connects the inner wall and outer circumference of the first oil distribution sleeve 41, leaving a gap between the first oil distribution sleeve 41 and the second oil distribution sleeve 43. The second oil distribution sleeve 43 is provided with a second passage 48 for oil flow. The second passage 48 connects the inner wall and outer circumference of the second oil distribution sleeve 43, leaving a gap between the second oil distribution sleeves 43. The first and second passages 47, 48 are connected to the second oil return port 27.

[0089] The secondary oil distribution sleeve 43 is provided with a third channel 49, which connects the front end surface of the secondary oil distribution sleeve 43 with the outer peripheral surface of the secondary oil distribution sleeve 43. The secondary oil distribution sleeve 43 is provided with a fourth channel 40 for oil to pass through; during the entire movement process of the normal operation of the piston 4, the fourth channel 40 is occasionally connected to the third channel 49.

[0090] In this application, the reversing valve 3 performs graded braking, and the reversing braking process is smoother and more efficient.

[0091] The push valve assembly has graded braking, and the reversing is smoother. Different reversing braking efficiencies can be achieved through the effective areas of each level of the push valve assembly. It has a wide range of applications, and is especially suitable for the reversing mechanism of high-power equipment.

[0092] The rest of the content of the third embodiment is the same as that of the first or second embodiment.

[0093] The motion process of this application is as follows:

[0094] Stroke motion:

[0095] like Figure 6 As shown: the kinematic pair (piston 4, reversing valve 3, push rod, secondary oil distribution sleeve 43, primary oil distribution sleeve 41, primary oil distribution ring 42) is subjected to the high-pressure force at the second high-pressure oil port 28 and the high-pressure force at the front chamber 21. The combined force moves forward, and the kinematic pair accelerates forward until the primary oil distribution sleeve 41 reaches the left stroke limit. The primary oil distribution sleeve 41 and the primary oil distribution ring 42 stop moving, and the previous high-pressure oil action area is reduced. The kinematic pair (piston 4, reversing valve 3, push rod, secondary oil distribution sleeve 43) continues to accelerate forward, but the acceleration decreases.

[0096] like Figure 7 As shown, the kinematic pair (piston 4, reversing valve 3, push rod, and secondary oil distribution sleeve 43) is still subjected to the high-pressure force at the second high-pressure oil port 28 and the high-pressure force at the front chamber 21, and the combined force moves forward until the secondary oil distribution sleeve 43 reaches the mechanical limit. At this time, the high-pressure oil at the first high-pressure oil port 24 enters the rear end face of the piston 4 from the front end of the reversing valve 3 through the guide groove 12, causing the piston 4 to separate from the reversing valve 3. Because the effective area of ​​the rear end face of the piston 4 is much larger than the effective area of ​​the front chamber 21, the piston 4 accelerates forward; the effective area of ​​the front end face of the reversing valve 3 is larger than the effective area of ​​the rear end of the push rod 44, and smaller than the effective area of ​​the rear end face of the first oil distribution sleeve 41 and the second oil distribution sleeve 43 combined, so the reversing valve 3 is pressed and stationary in this position.

[0097] like Figure 8 As shown: the piston 4 accelerates forward and is connected to the oil port of the first signal channel 13. The high-pressure oil enters the rear end of the reversing valve 3 through the first signal channel 13 and the oil circuit 11. The effective area of ​​the high-pressure oil on the rear side of the reversing valve 3 (the sum of the effective area of ​​the rear end of the reversing valve 3 and the effective area of ​​the rear end face of the push valve stem 44) is larger than the effective area of ​​the front end face of the reversing valve 3. The area difference is the area difference between the rear end face and the front end face of the push valve stem 44. Therefore, the main force of the reversing valve 3 is converted into the rear side thrust, and the combined force is forward, and the reversing valve 3 starts to accelerate forward.

[0098] like Figure 9As shown: the piston 4 and the reversing valve 3 accelerate forward at different accelerations and speeds until the reversing valve 3 closes the first high-pressure oil port 24, and the rear end face of the piston 4 and the front and rear chambers of the reversing valve 3 lose the effect of high-pressure oil. At the same time, the piston 4 collides with the drill tool 9, transferring the impact energy to the drill tool 9, and preparing to start a new cycle of backward return motion; the main force of the reversing valve 3 is converted into the force exerted on the valve stem 44, and the combined force continues to move forward until it contacts the rear end face of the piston 4 and waits for the next return stage.

[0099] Return Movement:

[0100] like Figure 10 As shown: the push valve stem 44 is acted upon by constant high-pressure oil, and the resultant force is forward, so that the reversing valve 3 is pressed to the front end of the stroke; the rear end face of the piston 4 is connected to the first oil return port 25, and the first high-pressure oil port 24 is closed; the front chamber 21 of the piston 4 takes in high-pressure oil, and the rear chamber 22 returns low-pressure oil, and the rear end face is connected to the return oil port of the rear end face of the reversing valve 3; since the effective area of ​​the rear end of the push valve stem 44 is smaller than the effective area of ​​the high-pressure oil in the front chamber 21 of the piston 4, the main force is the force of the front chamber 21, and the resultant force is backward, so the piston 4 drives the main oil distribution valve and the push valve stem 44 to accelerate backward.

[0101] like Figure 11 As shown: the piston 4 moves backward to accelerate until the first signal oil port 23 is connected to the first oil return port 25 at the rear end of the piston 4, and then the return oil relies on the first oil return port 25 at the rear end of the reversing valve 3 and the first signal oil port 23 to return the oil together; the main force is still the force of the piston 4 at the front chamber 21, and the combined force is backward, so the piston 4 continues to drive the reversing valve 3 and the valve stem 44 to accelerate backward.

[0102] like Figure 12 As shown: the piston 4 moves backward and accelerates until the first oil return port 25 of the rear chamber 22 of the reversing valve 3 is closed, and the oil return of the piston 4 relies only on the single-channel oil return of the second signal oil port 26; the main force is still the force of the front chamber 21, and the combined force is backward, so the piston 4 keeps driving the reversing valve 3 and the valve stem 44 to move backward and accelerate.

[0103] like Figure 13 As shown in the figure: the piston 4 moves backward with acceleration until the reversing valve 3 contacts the secondary oil distribution sleeve 43 and pushes the secondary oil distribution sleeve 43 to move backward. At this time, since the rear end of the secondary oil distribution sleeve 43 is acted upon by the high-pressure oil at the second high-pressure groove, the forward resultant force on the reversing valve 3 is further increased, and its effective area is larger than the effective area of ​​the high-pressure oil of the piston 4 at the front chamber 21. Therefore, the moving pair (piston 4, reversing valve 3, push rod, secondary oil distribution sleeve 43) moves backward together with deceleration.

[0104] like Figure 14As shown: the piston 4 moves backward to perform a deceleration motion until the reversing valve 3 contacts the primary oil distribution sleeve 41 and pushes the secondary oil distribution sleeve 43 to move backward. At this time, since the rear ends of the secondary oil distribution sleeve 43 and the rear ends of the primary oil distribution sleeve 41 are both affected by the high-pressure oil, the forward resultant force on the reversing valve 3 is further increased, and its effective area is larger than the effective area of ​​the high-pressure oil in the front chamber 21 of the piston 4. Therefore, the moving pair (piston 4, reversing valve 3, push rod, secondary oil distribution sleeve 43, primary oil distribution sleeve 41, primary oil distribution ring 42) performs a deceleration motion backward together, and the deceleration effect is stronger.

[0105] like Figure 15 As shown: the piston 4 moves backward in a decelerating motion until the valve stem 44 reaches the rear travel limit. At this time, the speed of the kinematic pair (piston 4, reversing valve 3, push rod, secondary oil distribution sleeve 43, primary oil distribution sleeve 41, primary oil distribution ring 42) is close to 0. At this point, the return process is completed, completing one cycle of motion, and then continuing to the next cycle.

[0106] A rock drill comprises the graded braking impact device according to any one of the above embodiments.

[0107] The present application has been described in detail above. Specific examples have been used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is intended only to facilitate understanding of the present application and its core concepts. It should be noted that, without departing from the principles of the present application, a number of improvements and modifications may be made to the present application by a person skilled in the art, and such improvements and modifications shall fall within the scope of protection of the claims of the present application.

Claims

1. An impact device for a rock drill, characterized in that The invention comprises a housing (1), a cylinder sleeve (2), a reversing valve (3) and a piston (4); the piston (4) and the reversing valve (3) are coaxially arranged in the cylinder sleeve (2); the cylinder sleeve (2) is installed in the housing (1); the housing (1) is provided with an oil inlet main path (5) and an oil return main path (6); the cylinder sleeve (2) is provided with an oil inlet branch path (7) communicating with the oil inlet main path (5) and an oil return branch path (8) communicating with the oil return main path (6); the reversing valve (3) is provided with an oil path (11); the oil path (11) is connected to the front end face and the rear end face of the reversing valve (3); The inner wall surface of the cylinder sleeve (2) is provided with a front chamber (21), a rear chamber (22), a first signal oil port (23), a first high-pressure oil port (24), a first oil return port (25), a second signal oil port (26), a second oil return port (27), and a second high-pressure oil port (28) in sequence from front to back; the front chamber (21) is connected to the oil inlet branch (7), the rear chamber (22) is connected to the oil return branch (8), the reversing valve (3) and the piston (4) are coaxially arranged and installed, and the front chamber (21) and the rear chamber (22) alternately change oil to realize the movement of the reversing valve (3); the first signal oil port (23) and the second signal oil port (26) are connected through an oil channel provided on the cylinder sleeve (2), the first high-pressure oil port (24) and the second high-pressure oil port (28) are connected to the oil inlet branch (7), and the first oil return port (25) and the second oil return port (27) are connected to the oil return branch (8); The impact device of the rock drill also includes a push valve assembly; a piston (4), a reversing valve (3) and a push valve assembly are sequentially arranged in the cylinder sleeve (2) from front to back; the reversing valve (3) is a cylindrical structure, and a notch for accommodating the push valve assembly is provided on the rear end surface of the reversing valve (3); the push valve assembly includes a primary oil distribution sleeve (41), a secondary oil distribution sleeve (43) and a push valve rod (44); the primary oil distribution sleeve (41) is sleeved outside the secondary oil distribution sleeve (43), and the secondary oil distribution sleeve (43) is sleeved outside the push valve rod (44); A limiting groove (45) is provided in the cylinder liner (2), and the limiting groove (45) and the rear end surface of the inner cavity of the cylinder liner (2) constitute a stroke limit of the first-stage oil distribution sleeve (41); during the entire movement process of the normal operation of the piston (4), the first-stage oil distribution sleeve (41) at least partially moves between the limiting groove (45) and the rear end surface of the inner cavity of the cylinder liner (2); the rear end surface of the first-stage oil distribution sleeve (41) and the rear end surface of the inner cavity of the cylinder liner (2) constitute a stroke limit of the second-stage oil distribution sleeve (43).

2. The impact device of a rock drill according to claim 1, characterized in that The front end of the reversing valve (3) has a contact surface, which contacts the piston (4). A conducting groove (12) is provided on the contact surface, and the conducting groove (12) connects the oil circuit (11) and the outer periphery of the reversing valve (3).

3. The impact device of a rock drill according to claim 1, characterized in that During the entire movement process of the piston (4) in normal operation, the first-stage oil distribution sleeve (41) at least partially moves between the rear end face of the first-stage oil distribution sleeve (41) and the rear end face of the inner cavity of the cylinder sleeve (2); a limiting cavity (46) is provided in the second-stage oil distribution sleeve (43), and the limiting cavity (46) and the rear end face of the inner cavity of the cylinder sleeve (2) constitute a stroke limit of the push valve rod (44); during the entire movement process of the piston (4) in normal operation, the push valve rod (44) at least partially moves between the limiting cavity (46) and the rear end face of the inner cavity of the cylinder sleeve (2).

4. The impact device of a rock drill according to claim 1, characterized in that During the entire movement process of the piston (4) in normal operation, the movement stroke of the push valve rod (44) is greater than the movement stroke of the secondary oil distribution sleeve (43), and the movement stroke of the secondary oil distribution sleeve (43) is greater than the movement stroke of the primary oil distribution sleeve (41); the second high-pressure oil port (28) is communicated with the primary oil distribution sleeve (41), the secondary oil distribution sleeve (43), and the rear end face of the push valve rod (44); the second high-pressure oil port (28) is communicated with the rear end face of the oil distribution ring (42); the primary oil distribution sleeve (41) is provided with a first channel (47) for oil to pass through, the first channel (47) communicates with the inner wall surface and the outer peripheral surface of the primary oil distribution sleeve (41), and a gap exists between the primary oil distribution sleeve (41) and the secondary oil distribution sleeve (43).

5. The impact device of a rock drill according to claim 4, characterized in that The secondary oil distribution sleeve (43) is provided with a second channel (48) for oil to pass through. The second channel (48) communicates with the inner wall surface and the outer peripheral surface of the secondary oil distribution sleeve (43). There is a gap between the secondary oil distribution sleeves (43) and the secondary oil distribution sleeves (43); the first channel (47) and the second channel (48) are communicated with the second oil return port (27).

6. The impact device of a rock drill according to claim 5, characterized in that The secondary oil distribution sleeve (43) is provided with a third channel (49), which communicates the front end surface of the secondary oil distribution sleeve (43) with the outer peripheral surface of the secondary oil distribution sleeve (43). The secondary oil distribution sleeve (43) is provided with a fourth channel (40) for oil to pass through; during the entire movement process of the normal operation of the piston (4), the fourth channel (40) is occasionally connected to the third channel (49).

7. A rock drill, characterized in that A rock drill comprising an impact device according to any one of claims 1 to 6.

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