Local grinding device for inner hole surface

Abstract

The invention provides an inner hole surface local grinding device which is arranged in a workpiece, the grinding device grinds a corrosion hole in the inner surface of the workpiece, the grinding device comprises a connecting rod and a purging system arranged on the connecting rod, the connecting rod is further provided with a grinding head and directly faces the corrosion hole, the connecting rod is further provided with a balancing weight, and the purging system is arranged on the connecting rod. The balancing weight is arranged close to the grinding head and located on one side of the tail end of the connecting rod, the elastic supporting frame is arranged on the tail rod, the tail rod is rotationally connected with the tail end of the connecting rod, and the elastic supporting frame is arranged on the tail rod. The balancing weight exerts pressure on the grinding head under the action of the elastic supporting frame, and the magnitude of the load is dynamically matched and associated with the grinding depth and linearly changes with the grinding depth in an inverse proportion mode. The load applied to the grinding head by the balancing weight is dynamically associated and adjusted according to the residual depth of the erosion hole, the pressure load is gradually changed from large to small, the abrasion depth of the grinding head is effectively controlled, and accurate grinding of the erosion hole in the surface of the inner hole of the workpiece is achieved.

Description

Technical Field

[0001] The present invention belongs to the field of grinding devices, and particularly relates to a local inner hole surface grinding device. Background Art

[0002] In the process of exploration and development of energy such as oil and natural gas, it is necessary to continuously send the drill bit to a deeper position by connecting single drill tools in series. The existing drill tools are of a hollow structure, and the internal channels need to transport high-pressure drilling fluids (including mud, clear water, gas, etc.). Therefore, erosion damage will be formed on the inner surface of the drill tool workpiece. Especially for some workpieces with other workpieces installed inside, such as logging instrument components, when local damage occurs to the components installed inside the workpiece, a leakage channel for high-pressure liquid will be formed, thereby directly eroding the inner surface of the workpiece to form erosion holes. When the thickness of the erosion holes exceeds a certain range, the workpiece will be scrapped. At present, for the erosion damage inside the components, it is possible to perform surfacing repair after surface cleaning of the erosion holes, such as the erosion repair of the drilling pump hydraulic cylinder liner. However, for the cleaning problem of the erosion damage parts on the inner surface of the long-hole workpiece, the existing grinding equipment has two problems. One is that the length of the connecting rod is limited. The other is that when the connecting rod is too long, the grinding head at the end cannot obtain an effective frictional load, the grinding head has a large jumping amplitude during the working process, the wear efficiency is low, and the wear depth is uncontrollable, and the surface quality after wear is poor. Therefore, there is an urgent need to study a local inner hole surface grinding equipment to address the deficiencies of the existing technology and solve the problems of the cleaning quality and cleaning efficiency of the erosion damage on the inner hole surface at a long distance of the workpiece. Summary of the Invention

[0003] In view of the above problems, the present invention provides a local inner hole surface grinding device which is arranged inside the workpiece, and the grinding device grinds the erosion holes on the inner surface of the workpiece. The grinding device includes a connecting rod and a purging system arranged on the connecting rod. A grinding head is also arranged on the connecting rod and is aligned with the erosion hole. A counterweight is also arranged on the connecting rod. The counterweight is arranged adjacent to the grinding head and on one side of the end of the connecting rod. The grinding device further includes a tail rod and an elastic support frame. The elastic support frame is arranged on the tail rod, and the tail rod is rotatably connected to the end of the connecting rod. Under the action of the elastic support frame, the pressure load applied by the counterweight to the grinding head is dynamically adapted and associated with the grinding depth, and changes in an inverse proportional linear relationship with the grinding depth.

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

[0005] Further, an air hole and a nozzle connection hole are arranged on the connecting rod. The air hole is arranged on the body section, and a plurality of the nozzle connection holes are arranged on the limiting section.

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

[0007] Further, 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 the air hole opening, and a plurality of the nozzles are respectively arranged on a plurality of the nozzle connection holes.

[0008] Further, a first keyway is arranged on the assembly section, a second keyway is arranged on the grinding head, and the assembly section and the grinding head are fixedly fitted through a key and the first keyway and the second keyway.

[0009] Further, the grinding device further includes a rotating mechanism, and the rotating mechanism is arranged on the outermost side of the upper body section of the connecting rod.

[0010] Further, the grinding device further includes a nut, and the nut is arranged on the external thread section and is located between the counterweight block and the grinding head.

[0011] Further, 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 sleeved on the tail rod, the first support beam is connected to the bottom of the fixed sleeve, the second support beam is sleeved outside the first support beam and the bottom of the second support beam is spaced from the bottom of the first support beam by a certain distance, the base is arranged at the bottom of the second support beam, and the spring assembly is sleeved outside the first support beam and the second support beam and is located between the fixed sleeve and the base.

[0012] Further, the grinding device further includes a rolling bearing, and the connection section between the tail rod and the connecting rod is rotationally connected through the rolling bearing.

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

[0014] By arranging a counterweight block, a grinding head, a tail rod, and an elastic support frame, on the one hand, the counterweight block provides a frictional pressure load for the grinding head on the connecting rod. Under the action of the elastic support frame, the resilience force generated by the elastic deformation generates a resistance to the counterweight block, and the load applied by the counterweight block to the grinding head is dynamically correlated and adjusted according to the remaining depth of the erosion hole. The pressure load gradually changes from large to small, so as to effectively realize the dynamic correlation between the pressure load on the grinding head and the wear depth, effectively control the wear depth of the grinding head, and realize the precise grinding of the erosion hole on the inner hole surface of the workpiece. On the other hand, the arranged tail rod solves the problem that the prior art cannot effectively repair the erosion hole or damaged surface at a long-distance part of the inner hole. When the connecting rod is too long, the grinding head at the end has a large jumping amplitude during the working process, the wear efficiency is low, the wear depth is uncontrollable, and the surface quality after wear is poor. The arrangement of the tail rod effectively solves the grinding quality of the erosion hole at a long-distance part of the inner hole of the workpiece.

[0015] Other features and advantages of the present invention will be described in the following specification, and, in part, will be obvious from the specification, or will be understood by implementing the present invention. The objectives and other advantages of the present invention can be achieved and obtained by the structure pointed out in the specification, the claims, and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0017] Figure 1 Shows a schematic diagram of the grinding device in the embodiment of the present invention;

[0018] Figure 2 Shows a schematic diagram of the connecting rod in the embodiment of the present invention;

[0019] Figure 3 Shows a schematic diagram of the elastic support frame in the embodiment of the present invention;

[0020] Figure 4 Shows a schematic diagram of the connection between the connecting rod and the tail rod in the embodiment of the present invention.

[0021] In the figure, 100 - workpiece, 111 - etching hole, 1 - connecting rod, 11 - body section, 12 - limiting section, 13 - assembly section, 14 - external thread section, 15 - connection section, 16 - air hole opening, 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 DESCRIPTION OF THE EMBODIMENTS

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0023] As Figure 1As shown in the figure, a local grinding device for the inner hole surface is arranged inside the workpiece 100. The grinding device grinds the corrosion holes 111 on the inner surface of the workpiece 100. The grinding device includes a connecting rod 1 and a purging system arranged on the connecting rod 1. A grinding head 2 is also arranged on the connecting rod 1 and is directly opposite to the corrosion hole 111. A counterweight 3 is also arranged on the connecting rod 1. The counterweight 3 is arranged 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 arranged on the tail rod 4. The tail rod 4 is rotatably connected to the end of the connecting rod 1. The pressure load exerted by the counterweight 3 on the grinding head 2 under the action of the elastic support frame 5 is dynamically adapted and correlated with the grinding depth, and shows an inverse proportional linear change with the grinding depth.

[0024] The connecting rod 1 has a central control structure. The purging system inputs gas from the outside into the hollow structure inside the connecting rod 1, and then transports the gas above the corrosion hole 111, and purges the dust and particles after grinding in time when the grinding head 2 grinds the corrosion hole 111, improving the grinding quality.

[0025] The material of the grinding head 2 includes quartz sand material, and its outer contour is an oval shape with the tip cut off. The grinding head 2 is provided with an inner hole matching the outer diameter of the assembly section 13 of the connecting rod 1, and a second key groove 21 matching the assembly section 13 on the connecting rod 1 is arranged on the inner hole. A first key groove 18 is arranged on the assembly section 13. The assembly section 13 and the grinding head 2 are fixed by a key 7 in cooperation with the first key groove 18 and the second key groove 21. In this way, when the connecting rod 1 rotates, the grinding head 2 also rotates accordingly.

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

[0027] When it is necessary to effectively repair the corrosion holes or damaged surfaces at long-distance parts of the inner hole of the workpiece 100, when the connecting rod 1 is too long, the grinding head 2 at the end of the connecting rod 1 has a large jumping amplitude during the working process, 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 situation of the end of the connecting rod 1 jumping is effectively solved, and the grinding efficiency and quality are improved.

[0028] When the grinding head 2 moves radially during the process of wearing the surface of the workpiece 100, the elastic support frame 5 will be compressed and deformed. The greater the elastic deformation of the elastic support frame 5, the greater the resilience generated, which will generate resistance to the counterweight 3, causing the pressure load exerted by the counterweight 3 on the grinding head 2 to decrease accordingly. The depth of the radial movement of the grinding head 2 during the process of wearing the surface of the workpiece 100 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 erosion hole 111, the elastic deformation of the elastic support frame 5 is the largest and the resilience is also the largest. The resistance generated by the elastic support frame 5 to the counterweight 3 causes the pressure load applied to the grinding head 2 to be zero.

[0029] The elastic deformation amount 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 sleeved 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 further includes a rotating mechanism, and the rotating mechanism is arranged on the outermost side of the upper body section 11 of the connecting rod 1. When the rotating mechanism rotates, it drives the connecting rod 1 to rotate. At this time, it is fixed by the cooperation of the key 7 with the first key groove 18 and the second key groove 21, so that the grinding head 2 also rotates accordingly.

[0032] At this time, the counterweight 3 exerts a radial pressure, causing the grinding head 2 to rotate and grind in the direction of the erosion hole 111. The depth of the radial movement of the grinding head 2 during the process of wearing the surface of the workpiece 100 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 erosion hole 111 of the workpiece 100 reaches the maximum depth of the erosion hole, under the action of the elastic support frame 5, the pressure load exerted by the counterweight 3 on the grinding head 2 is zero.

[0033] As Figure 2 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] An air hole 16 and a nozzle connection hole 17 are arranged on the connecting rod 1. The air hole 16 is arranged on the body section 11, and a plurality of the nozzle connection holes 17 are arranged on the limiting section 12.

[0035] The nozzle connection hole 17 is obliquely arranged and penetrates through the connecting rod 1. The included angle between the nozzle connection hole 17 and the axial direction of the connecting rod 1 is 30° - 60°.

[0036] In some embodiments, three groups of nozzle connection holes 17 are arranged 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 hole 16, and multiple nozzles 6 are respectively arranged on multiple nozzle connection holes 17.

[0038] The air pump transports gas through the air pipeline and the air hole 16 connected to the air pipeline into the connecting rod 1. The air pressure in 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 erosion hole 111. Due to the air pressure difference at this time, the gas ejected from the nozzle 6 can exactly purge the dust and particles after grinding.

[0039] The grinding device further includes a nut 8. The nut 8 is arranged on the external thread section 14 and is 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 the grinding head 2 from being misaligned and disengaging from the erosion hole 111 when the connecting rod 1 rotates, causing damage to other parts of the workpiece 100 due to incorrect grinding.

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

[0041] The second support beam 53 is a hollow pipe fitting with an inner diameter larger than the outer diameter of the first support beam 52. The fixing sleeve 51 is sleeved on the tail rod 4 to fix the tail rod 4. The lower part of the fixing sleeve 51 is in a flat shape. The bottom surface of the base 54 is arc-shaped and matches the inner hole radian of the workpiece 100. The upper surface is connected to the second support beam 53. The length and deformation amount 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 process of wearing the surface of the workpiece 100, the spring assembly 55 is compressed and deformed, and the pressure load exerted by the counterweight 3 on the grinding head 2 decreases accordingly. The depth of the radial movement of the grinding head 2 during the process of wearing the surface of the workpiece 100 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 erosion hole 111, the compression amount of the spring assembly 55 is the largest, and the pressure load exerted by the counterweight 3 on the grinding head 2 is zero.

[0043] Three sets of counterweights 3 are sleeved on the connecting rod 1 adjacent to the grinding head, and the number and weight of a single counterweight 3 can be selected and adjusted.

[0044] As Figure 4 shown, the grinding device further includes a rolling bearing 9, and a connecting section 15 of the tail rod 4 and the connecting rod 1 is rotatably connected through the rolling bearing 9.

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

[0046] Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements 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 local grinding device for the inner hole surface is arranged inside a workpiece (100), and the grinding device grinds an etched hole (111) on the inner surface of the workpiece (100), characterized in that: The grinding device includes a connecting rod (1) and a purging system arranged on the connecting rod (1). A grinding head (2) is also arranged on the connecting rod (1) and is directly opposite to the etching hole (111). A counterweight (3) is further arranged on the connecting rod (1). The counterweight (3) is arranged adjacent to the grinding head (2) and is located on one side of the end of the connecting rod (1). The grinding device further includes a tail rod (4) and an elastic support frame (5). The elastic support frame (5) is arranged on the tail rod (4). The tail rod (4) is rotatably connected to the end of the connecting rod (1). The counterweight (3) applies a pressure load to the grinding head (2) under the action of the elastic support frame (5), and the magnitude of the pressure load is dynamically adapted and associated with the grinding depth, showing an inverse proportional linear change with the grinding depth.

2. The local grinding device for the inner hole surface according to claim 1, wherein: 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 local grinding device for the inner hole surface according to claim 2, characterized in that: An air hole (16) and a nozzle connection hole (17) are arranged on the connecting rod (1). The air hole (16) is arranged on the body section (11). A plurality of the nozzle connection holes (17) are arranged on the limiting section (12).

4. The local grinding device for the inner hole surface according to claim 3, wherein: The included angle between the nozzle connection hole (17) and the axis of the connecting rod (1) is 30° - 60°.

5. The local grinding device for the inner hole surface according to claim 4, characterized in that: 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 hole (16). A plurality of the nozzles (6) are respectively arranged on a plurality of the nozzle connection holes (17).

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

7. The local grinding device for the inner hole surface according to claim 2, wherein: The grinding device further includes a rotating mechanism, and the rotating mechanism is arranged on the outermost side of the body section (11) of the connecting rod (1).

8. The local grinding device for the inner hole surface according to claim 7, wherein: The grinding device further includes a nut (8). The nut (8) is arranged on the external thread section (14) and is located between the counterweight (3) and the grinding head (2).

9. The local grinding device for the inner hole surface 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 from the bottom of the first support beam (52) by a certain distance. The base (54) is arranged 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 local grinding device for the inner hole surface according to claim 2, wherein: The grinding device further includes a rolling bearing (9), and a connecting section (15) of the tail rod (4) and the connecting rod (1) is rotationally connected through the rolling bearing (9).

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