A device for locally regrinding the surface of an internal bore

Abstract

The present application provides a kind of local hole surface local dressing device, is set in workpiece, and the dressing device is eroded on the inner surface of workpiece and is dressed, the dressing device includes connecting rod and is arranged on the blowing system of connecting rod, connecting rod is also provided with abrasive head and is opposite erosion, connecting rod is also provided with counterweight, counterweight is arranged in close proximity to abrasive head and is located in the end side of connecting rod, the dressing device further includes tail rod and elastic support frame, elastic support frame is arranged on tail rod, the end of tail rod is rotatably connected with connecting rod, and the pressure load size that counterweight exerts on abrasive head is dynamically adapted to be associated with dressing depth, and it is linearly changed in inverse proportion to dressing depth.Effective control of the wear depth of abrasive head is realized by the dynamic correlation adjustment of the load exerted on abrasive head by counterweight according to the residual depth of erosion hole, and the pressure load gradually changes from large to small, to realize the accurate dressing of erosion hole on the inner surface of workpiece hole.

Description

Technical Field

[0001] This invention belongs to the field of grinding devices, and specifically relates to a device for local grinding of the inner hole surface. Background Technology

[0002] In the exploration and development of energy resources such as oil and gas, drill bits are continuously advanced to deeper locations by connecting individual drill strings. Existing drill strings have a hollow structure, and their internal channels need to transport high-pressure drilling fluids (including mud, water, and gas). Therefore, erosion damage can occur on the inner surface of the drill string components. This is especially true when other components, such as logging instrument components, are installed inside. When these components suffer localized damage, high-pressure fluid leakage channels can form, directly eroding the inner surface of the drill string and creating erosion holes. When the thickness of these erosion holes exceeds a certain range, the entire drill string will be rendered unusable. Currently, erosion damage within components can be repaired by cleaning the surface of the erosion holes and then welding them back together. A typical example is the erosion repair of hydraulic cylinder liners in drilling pumps. However, existing grinding equipment for cleaning erosion damage on the inner surface of long-hole workpieces suffers from two main problems: firstly, the connecting rod length is limited; secondly, when the connecting rod is too long, the grinding head at the end cannot obtain effective frictional load, resulting in large grinding head runout during operation, low wear efficiency, uncontrollable wear depth, and poor surface quality after wear. Therefore, there is an urgent need to research a local grinding equipment for inner hole surfaces to address the shortcomings of existing technologies and solve the problems of cleaning quality and efficiency for erosion damage on long-distance inner hole surfaces of workpieces. Summary of the Invention

[0003] To address the aforementioned problems, this invention proposes a localized grinding device for the inner surface of a workpiece. The device is installed inside the workpiece and grinds pits on its inner surface. The device includes a connecting rod and a purging system mounted on the connecting rod. A grinding head is mounted on the connecting rod and faces the pit. A counterweight is also mounted on the connecting rod, located adjacent to the grinding head and at one end of the connecting rod. The device further includes a tail rod and an elastic support frame. The elastic support frame is mounted on the tail rod, which is rotatably connected to the end of the connecting rod. Under the action of the elastic support frame, the counterweight applies a pressure load to the grinding head, the magnitude of which is dynamically adapted to the grinding depth and changes inversely linearly with the grinding depth.

[0004] Furthermore, the connecting rod includes a body section, a limiting section, an assembly section, an external thread section, and a connecting section arranged sequentially. The grinding head is disposed on the assembly section between the limiting section and the external thread section. The counterweight is disposed on the external thread section. The tail rod is rotatably connected to the connecting section of the connecting rod.

[0005] Furthermore, the connecting rod is provided with an air vent and a nozzle connection hole, the air vent being located on the body section, and the plurality of nozzle connection holes being located on the limiting section.

[0006] Furthermore, the axial angle between the nozzle connection hole and the connecting rod is 30° to 60°.

[0007] Furthermore, the purging system includes an air pump, an air pipeline, and nozzles. The air pump is connected to the air pipeline, the air pipeline is connected to an air port, and multiple nozzles are respectively disposed on multiple nozzle connection holes.

[0008] Furthermore, a first keyway is provided on the assembly section, and a second keyway is provided on the grinding head. The assembly section and the grinding head are fixed together by keys that engage with the first and second keyways.

[0009] Furthermore, the grinding device also includes a rotating mechanism, which is located on the outermost side of the main body section of the connecting rod.

[0010] Furthermore, the grinding device also includes a nut, which is disposed on the external thread section and located between the counterweight and the grinding head.

[0011] Furthermore, the elastic support frame includes a fixed sleeve, a first support beam, a second support beam, a base, and a spring assembly. The fixed sleeve is fitted onto the tail rod. The first support beam is connected to the bottom of the fixed sleeve. The second support beam is fitted outside the first support beam, and the bottom of the second support beam is spaced a certain distance from the bottom of the first support beam. The base is located at the bottom of the second support beam. The spring assembly is fitted outside the first and second support beams and is located between the fixed sleeve and the base.

[0012] Furthermore, the grinding device also includes a rolling bearing, and the connecting section between the tail rod and the connecting rod is rotatably connected by the rolling bearing.

[0013] Compared with the prior art, the beneficial effects of this application are as follows:

[0014] This invention, through the configuration of a counterweight, grinding head, tail rod, and elastic support frame, achieves several improvements. Firstly, the counterweight provides a frictional pressure load to the grinding head on the connecting rod. Under the action of the elastic support frame, the rebound force generated by elastic deformation creates resistance on the counterweight. The load applied by the counterweight to the grinding head is dynamically adjusted according to the remaining depth of the eroded hole, with the pressure load gradually decreasing. This effectively achieves a dynamic correlation between the pressure load on the grinding head and the wear depth, effectively controlling the wear depth of the grinding head and enabling precise grinding of eroded holes on the inner surface of the workpiece. Secondly, the tail rod solves the problem of existing technologies being unable to effectively repair eroded holes or damaged surfaces over long distances in the inner hole. When the connecting rod is too long, the grinding head at the end experiences large fluctuations during operation, resulting in low wear efficiency, uncontrollable wear depth, and poor surface quality after wear. The tail rod effectively solves the problem of improving the grinding quality of eroded holes over long distances in the inner hole of the workpiece.

[0015] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description, claims and drawings. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A schematic diagram of the grinding device in an embodiment of the present invention is shown;

[0018] Figure 2 A schematic diagram of the connecting rod in an embodiment of the present invention is shown;

[0019] Figure 3 A schematic diagram of the elastic support frame in an embodiment of the present invention is shown;

[0020] Figure 4 A schematic diagram of the connection between the connecting rod and the tail rod in an embodiment of the present invention is shown.

[0021] In the diagram, 100-workpiece, 111-etched hole, 1-connecting rod, 11-body section, 12-limiting section, 13-assembly section, 14-external thread section, 15-connecting section, 16-air vent, 17-nozzle connection hole, 18-first keyway, 2-grinding head, 21-second keyway, 3-counterweight, 4-tail rod, 5-elastic support frame, 51-fixed sleeve, 52-first support beam, 53-second support beam, 54-base, 55-spring assembly, 6-nozzle, 7-key, 8-nut, 9-rolling bearing. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] like Figure 1As shown, a local grinding device for the inner surface of a hole is installed inside a workpiece 100. The grinding device grinds the etched holes 111 on the inner surface of the workpiece 100. The grinding device includes a connecting rod 1 and a purging system installed on the connecting rod 1. A grinding head 2 is also installed on the connecting rod 1 and faces the etched holes 111. A counterweight 3 is also installed on the connecting rod 1. The counterweight 3 is located adjacent to the grinding head 2 and is located on one side of the end of the connecting rod 1. The grinding device also includes a tail rod 4 and an elastic support frame 5. The elastic support frame 5 is installed on the tail rod 4. The tail rod 4 is rotatably connected to the end of the connecting rod 1. Under the action of the elastic support frame 5, the counterweight 3 applies a pressure load to the grinding head 2. The magnitude of the pressure load is dynamically adapted to the grinding depth and changes inversely proportionally to the grinding depth.

[0024] Connecting rod 1 is a central control structure. The purging system inputs gas from the outside into the hollow structure inside connecting rod 1, and then delivers the gas to the top of the etched hole 111. When the grinding head 2 is grinding the etched hole 111, the dust and particles after grinding are purged in time to improve the quality of grinding.

[0025] The grinding head 2 is made of quartz sand and has an outer contour that is elliptical with the tip shaved off. The grinding head 2 has an inner hole that matches the outer diameter of the assembly section 13 of the connecting rod 1, and a second keyway 21 that matches the assembly section 13 of the connecting rod 1 is provided on the inner hole. A first keyway 18 is provided on the assembly section 13. The assembly section 13 and the grinding head 2 are fixed together by a key 7 that engages with the first keyway 18 and the second keyway 21. This ensures that when the connecting rod 1 rotates, the grinding head 2 also rotates.

[0026] The grinding device also includes a tail rod 4 and an elastic support frame 5. The elastic support frame 5 is mounted on the tail rod 4, and the tail rod 4 is rotatably connected to the connecting section 15 of the connecting rod 1.

[0027] When it is necessary to effectively repair the corrosion holes or damaged surfaces of the long section of the inner hole of the workpiece 100, if the connecting rod 1 is too long, the grinding head 2 located at the end of the connecting rod 1 will have a large amplitude of runout during operation, resulting in low wear efficiency, uncontrollable wear depth, and poor surface quality after wear. By setting the tail rod 4 and the elastic support frame 5, the runout at the end of the connecting rod 1 is effectively solved, and the efficiency and quality of grinding are improved.

[0028] When the grinding head 2 moves radially during the wear of the workpiece 100 surface, the elastic support frame 5 will deform under pressure. The greater the elastic deformation of the elastic support frame 5, the greater the rebound force, which generates resistance on the counterweight 3. Consequently, the pressure load exerted by the counterweight 3 on the grinding head 2 is reduced. The depth of radial movement of the grinding head 2 during the wear of the workpiece 100 surface is linearly inversely proportional to the pressure load exerted by the counterweight 3 on the grinding head 2. When the wear depth of the grinding head 2 on the workpiece 100 reaches the maximum depth of the pit 111, the elastic deformation and rebound force of the elastic support frame 5 are at their maximum. The resistance generated by the elastic support frame 5 on the counterweight 3 makes the pressure load applied to the grinding head 2 zero.

[0029] The elastic deformation of the elastic support frame 5 can be selected or adjusted according to the load required by the grinding head 2 and the counterweight 3.

[0030] The counterweight 3 is mounted on the connecting rod 1 adjacent to the grinding head, and the number of counterweights 3 and the weight of a single counterweight can be selected and adjusted.

[0031] The grinding device also includes a rotating mechanism, which is located on the outermost side of the main body section 11 of the connecting rod 1. When the rotating mechanism rotates, it drives the connecting rod 1 to rotate. At this time, the connecting rod 1 is fixed by the key 7 engaging with the first keyway 18 and the second keyway 21, so that the grinding head 2 also rotates.

[0032] At this time, the counterweight 3 applies radial pressure, causing the grinding head 2 to rotate and grind in the direction of the etch hole 111. The depth of radial movement of the grinding head 2 during the wear of the workpiece 100 surface is linearly inversely proportional to the pressure load of the counterweight 3 on the grinding head 2. When the wear depth of the grinding head 2 on the etch hole 111 on the workpiece 100 reaches the maximum depth of the etch hole, the pressure load applied by the counterweight 3 on the grinding head 2 is zero under the action of the elastic support frame 5.

[0033] like Figure 2 As shown, the connecting rod 1 includes a body section 11, a limiting section 12, an assembly section 13, an external thread section 14, and a connecting section 15 arranged in sequence. The grinding head 2 is arranged on the assembly section 13 between the limiting section 12 and the external thread section 14, and the counterweight 3 is arranged on the external thread section 14.

[0034] The connecting rod 1 is provided with an air port 16 and a nozzle connection hole 17. The air port 16 is provided on the body section 11, and a plurality of nozzle connection holes 17 are provided on the limiting section 12.

[0035] The nozzle connection hole 17 is inclined and passes through the connecting rod 1. The axial angle between the nozzle connection hole 17 and the connecting rod 1 is 30° to 60°.

[0036] In some embodiments, three sets of nozzle connection holes 17 are provided and evenly distributed on the limiting section 12.

[0037] The purging system includes an air pump, an air pipeline, and nozzles 6. The air pump is connected to the air pipeline, the air pipeline is connected to the air port 16, and multiple nozzles 6 are respectively disposed on multiple nozzle connection holes 17.

[0038] The air pump delivers gas to the connecting rod 1 through the air pipeline and the air port 16 connected to the air pipeline. The air pressure inside the connecting rod 1 causes the gas to be discharged through the nozzle connection hole 17. At this time, the axial angle between the nozzle 6 connected to the nozzle connection hole 17 and the connecting rod 1 is 30° to 60°, which is exactly located on the contact surface between the grinding head 2 and the etching hole 111. At this time, due to the air pressure difference, the gas sprayed by the nozzle 6 can just blow away the dust and particles after grinding.

[0039] The grinding device also includes a nut 8, which is disposed on the external thread section 14 and located between the counterweight 3 and the grinding head 2. The nut 8 and the limiting section 12 limit the grinding head 2 to prevent it from being misaligned and dislodging from the etched hole 111 when the connecting rod 1 rotates, thus preventing damage to other parts of the workpiece 100 caused by accidental grinding.

[0040] like Figure 3 As shown, the elastic support frame 5 includes a fixed sleeve 51, a first support beam 52, a second support beam 53, a base 54, and a spring assembly 55. The fixed sleeve 51 is sleeved on the tail rod 4. The first support beam 52 is connected to the bottom of the fixed sleeve 51. The second support beam 53 is sleeved outside the first support beam 52, and the bottom of the second support beam 53 is spaced a certain distance from the bottom of the first support beam 52. The base 54 is located at the bottom of the second support beam 53. The spring assembly 55 is sleeved outside the first support beam 52 and the second support beam 53 and is located between the fixed sleeve 51 and the base 54.

[0041] The second support beam 53 is a hollow tube with an inner diameter larger than the outer diameter of the first support beam 52. The fixing sleeve 51 is fitted onto the tail rod 4 to fix the tail rod 4. The lower part of the fixing sleeve 51 is flat, and the bottom surface of the base 54 is arc-shaped, matching the arc of the inner hole of the workpiece 100. The upper surface is connected to the second support beam 53. The length and deformation of the spring assembly 55 can be selected or adjusted according to the load required by the grinding head 2 and the counterweight 3.

[0042] When the grinding head 2 moves radially during the wear process on the surface of the workpiece 100, the spring assembly 55 is compressed and deformed, and the pressure load exerted on the grinding head 2 by the counterweight 3 decreases accordingly. The depth of radial movement of the grinding head 2 during the wear process on the surface of the workpiece 100 is linearly inversely proportional to the pressure load exerted on the grinding head 2 by the counterweight 3. When the wear depth of the grinding head 2 on the workpiece 100 reaches the maximum depth of the pit 111, the compression of the spring assembly 55 is at its maximum, and the pressure load exerted on the grinding head 2 by the counterweight 3 is zero.

[0043] The counterweight 3 is mounted on the connecting rod 1 adjacent to the grinding head, and the number of counterweights 3 and the weight of a single counterweight can be selected and adjusted.

[0044] like Figure 4 As shown, the grinding device also includes a rolling bearing 9, and the connecting section 15 between the tail rod 4 and the connecting rod 1 is rotatably connected by the rolling bearing 9.

[0045] Tail rod 4 is connected to connecting rod 1 via rolling bearing 9. When connecting rod 1 is rotated for grinding, tail rod 4 does not need to rotate with connecting rod 1. The end of connecting rod 1 is fixed while it rotates, making connecting rod 1 more stable during operation and less prone to bouncing. In addition, it also solves the problem that the length of connecting rod 1 is insufficient when long-distance etched holes 111 need to be ground.

[0046] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A device for local surface grinding of an inner hole, disposed inside a workpiece (100), the device grinding to grind the etched holes (111) on the inner surface of the workpiece (100), characterized in that: The grinding device includes a connecting rod (1) and a purging system mounted on the connecting rod (1). A grinding head (2) is mounted on the connecting rod (1) and faces the etched hole (111). A counterweight (3) is mounted on the connecting rod (1). The counterweight (3) is located close to the grinding head (2) and on one side of the end of the connecting rod (1). The grinding device also includes a tail rod (4) and an elastic support frame (5). The elastic support frame (5) is mounted on the tail rod (4). The tail rod (4) is rotatably connected to the end of the connecting rod (1). Under the action of the elastic support frame (5), the counterweight (3) applies pressure load to the grinding head (2). The magnitude of the pressure load is dynamically adapted to the grinding depth and changes inversely proportionally to the grinding depth.

2. The device for local grinding of inner hole surfaces according to claim 1, characterized in that: The connecting rod (1) includes a body section (11), a limiting section (12), an assembly section (13), an external thread section (14), and a connecting section (15) arranged in sequence. The grinding head (2) is arranged on the assembly section (13) between the limiting section (12) and the external thread section (14). The counterweight (3) is arranged on the external thread section (14). The tail rod (4) is rotatably connected to the connecting section (15) of the connecting rod (1).

3. The device for local grinding of inner hole surfaces according to claim 2, characterized in that: The connecting rod (1) is provided with an air port (16) and a nozzle connection hole (17). The air port (16) is provided on the body section (11), and the multiple nozzle connection holes (17) are provided on the limiting section (12).

4. The device for local grinding of inner hole surfaces according to claim 3, characterized in that: The axial angle between the nozzle connection hole (17) and the connecting rod (1) is 30° to 60°.

5. The device for local grinding of inner hole surfaces according to claim 4, characterized in that: The purging system includes an air pump, an air line and nozzles (6). The air pump is connected to the air line, the air line is connected to the air port (16), and a plurality of nozzles (6) are respectively disposed on a plurality of nozzle connection holes (17).

6. The device for local grinding of inner hole surfaces according to claim 2, characterized in that: The assembly section (13) is provided with a first keyway (18), and the grinding head (2) is provided with a second keyway (21). The assembly section (13) and the grinding head (2) are fixed together by a key (7) in cooperation with the first keyway (18) and the second keyway (21).

7. The device for local grinding of inner hole surfaces according to claim 2, characterized in that: The grinding device also includes a rotating mechanism, which is located on the outermost side of the main body section (11) of the connecting rod (1).

8. The device for local grinding of inner hole surfaces according to claim 7, characterized in that: The grinding device also includes a nut (8), which is disposed on the external thread section (14) and located between the counterweight (3) and the grinding head (2).

9. The device for local grinding of inner hole surfaces according to claim 1, characterized in that: The elastic support frame (5) includes a fixed sleeve (51), a first support beam (52), a second support beam (53), a base (54), and a spring assembly (55). The fixed sleeve (51) is sleeved on the tail rod (4). The first support beam (52) is connected to the bottom of the fixed sleeve (51). The second support beam (53) is sleeved outside the first support beam (52), and the bottom of the second support beam (53) is spaced a certain distance from the bottom of the first support beam (52). The base (54) is located at the bottom of the second support beam (53). The spring assembly (55) is sleeved outside the first support beam (52) and the second support beam (53) and is located between the fixed sleeve (51) and the base (54).

10. The device for local grinding of the inner hole surface according to claim 2, characterized in that: The grinding device also includes a rolling bearing (9), and the connecting section (15) of the tail rod (4) and the connecting rod (1) is rotatably connected by the rolling bearing (9).

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