Drilling jig and machining method for pin hole of fork-shaped impeller of steam turbine rotor

Abstract

The invention belongs to the technical field of steam turbine rotor impeller machining, and particularly relates to a drill jig and a machining method for a steam turbine rotor fork-type impeller pin hole, and the drill jig comprises a workbench, a positioning assembly and a drill jig assembly; the drilling jig assembly comprises a pressing disc, a hydraulic cylinder, a movable sleeve, a drilling jig plate, a side edge plate, a drilling sleeve and a punching mechanism. An annular guide rail is arranged on the side face of the pressing disc. A movable sleeve is connected to the annular guide rail in a sliding manner; a drill plate is connected into the movable sleeve in a sliding mode. Through cooperative work of the positioning assembly and the drill jig assembly, accurate control over the angle and the position in the impeller pin hole machining process is achieved, the problem of hole position deviation caused by manual line drawing errors in a traditional machining mode is effectively solved, after one-time punching, the side edge plate, the drill jig plate and the movable sleeve can be rotated integrally, and the machining efficiency is improved. And the drilling jig is adjusted to the next punching angle, machining of all pin holes with different angles can be continuously completed without repeatedly disassembling the drilling jig, and the machining efficiency is remarkably improved.

Description

Technical Field

[0001] This invention belongs to the field of steam turbine rotor impeller processing technology, specifically a drilling jig and processing method for pin holes of a steam turbine rotor fork-type impeller. Background Technology

[0002] Machining the pin holes in the forked impeller of a steam turbine rotor is a critical process in steam turbine manufacturing. These pin holes are typically radially distributed along the impeller circumference, with small diameters and large depths, requiring high positional accuracy. During assembly, the blades are aligned with these pin holes on the impeller via the pin holes on their forked blade roots, and then connected and secured with pins or tie rods to ensure the concentricity and operational stability of the entire blade assembly. Therefore, efficiently and accurately machining a series of pin holes with consistent positional accuracy is a crucial technical aspect for ensuring the assembly quality and operational reliability of the steam turbine rotor.

[0003] Chinese patent application CN101670455B discloses a drilling jig for pin holes in a steam turbine rotor fork-shaped impeller and a method for machining the pin holes. The key technical points are: it includes a full-circumferential drilling jig and an arc-segment drilling jig. The full-circumferential drilling jig has several circumferentially distributed reference holes, the number of which is less than the number of pin holes in the corresponding part of the fork-shaped impeller; the arc-segment drilling jig has several reference holes, the number of which is equal to the number of pin holes in the corresponding part of the fork-shaped impeller; the positional accuracy of the reference holes on both the full-circumferential and arc-segment drilling jigs is consistent with the positional accuracy of the pin holes in the fork-shaped impeller. The beneficial effect is that the full-circumferential and arc-segment drilling jigs are used together. The full-circumferential drilling jig drills a ring of holes on the impeller, which serves as the positioning holes for the arc-segment drilling jig. Then, the arc-segment drilling jig is used to machine the impeller pin holes segment by segment, ensuring that the positional accuracy of all pin holes on the impeller is consistent.

[0004] However, the above technology has the following drawbacks: it adopts a segmented drill jig body and a complex tensioning device, which is not only time-consuming to assemble and disassemble, but also prone to cumulative positioning errors that are difficult to eliminate due to the conversion of the reference or slight changes in the clamping force during the repeated replacement and positioning of the arc segment drill jig. In addition, the processing flow is not continuous and the efficiency is limited. It must follow a strict step-by-step sequence of "drilling a small number of positioning holes around the whole circle first → disassembly and assembly → then processing multiple arc segments". After each arc segment is processed, the drill jig needs to be disassembled, moved and realigned. The process is frequently interrupted and cannot achieve rapid and continuous processing of holes at different angles, resulting in low overall efficiency.

[0005] Therefore, the present invention provides a drilling jig and processing method for the pin hole of the fork-shaped impeller of a steam turbine rotor. Summary of the Invention

[0006] In order to overcome the shortcomings of the prior art, at least one technical problem raised in the background art is solved.

[0007] The technical solution adopted by the present invention to solve its technical problem is: a drilling jig for a turbine rotor fork-type impeller pin hole, comprising a worktable, a positioning assembly and a drilling jig assembly;

[0008] A central column and a bracket are fixedly connected to the surface of the workbench; the central column is used to install the impeller.

[0009] The positioning component is disposed on the surface of the workbench and is used to accurately position the drilling angle of the impeller;

[0010] The drill jig assembly is disposed between the workbench and the support and is used to determine the drilling position for a single angle; the drill jig assembly includes a pressure plate, a hydraulic cylinder, a movable sleeve, a drill template, a side plate, a drill sleeve, and a drilling mechanism;

[0011] A hydraulic cylinder is connected between the pressure plate and the support; an annular guide rail is provided on the side of the pressure plate; a movable sleeve is slidably connected on the annular guide rail; a drill template is slidably connected inside the movable sleeve; a side plate is fixedly connected to the end of the drill template; a set of drill sleeves are evenly distributed on the surface of the drill template; a drilling mechanism is provided on the drill template; the drilling mechanism is used to machine pin holes for the impeller along the drill sleeves.

[0012] Preferably, a control wheel is provided inside the central column; a set of protrusions are evenly distributed on the side of the control wheel; a handwheel is provided at the top of the central column; a stud is fixedly connected between the handwheel and the control wheel; a set of sliding grooves are evenly distributed on the side of the central column; a top block is slidably connected inside the sliding groove; a spring is fixedly connected between the top block and the sliding groove; a connecting rod is fixedly connected to the surface of the top block; and an arc-shaped block is fixedly connected to one end of the connecting rod extending to the control wheel.

[0013] Preferably, the positioning component includes a support plate; a set of positioning grooves are evenly distributed on the side of the support plate; a set of extension grooves are evenly distributed on the upper side of the support plate; a positioning block is fixedly connected to the lower end of the side plate; an electric cylinder is connected between the drill template and the movable sleeve; a set of gaskets are evenly distributed on the bottom of the side plate; and a set of through grooves are opened on the surface of the gaskets.

[0014] Preferably, the drilling mechanism includes a lifting plate; one end of the lifting plate is slidably connected to a side edge plate; a guide post is fixedly connected to the surface of the drilling template, and the guide post passes through the lifting plate and is slidably connected to it; a rack is provided on the surface of the guide post; a lifting gear is rotatably connected inside the lifting plate, and the lifting gear meshes with the rack; a motor is coaxially connected to the lifting gear; a second motor is fixedly connected to the surface of the lifting plate; and a set of drill bits is driven by the second motor.

[0015] Preferably, each drill bit has a drilling gear connected to its upper end via a connector, and the drilling gears mesh with each other; one of the drilling gears is coaxially connected to the motor.

[0016] Preferably, a drainage hole is provided between the side of the gasket and each through groove.

[0017] Preferably, an air pump and a hollow sleeve are fixedly connected to the bottom of the side plate; the hollow sleeve and each through slot are interconnected through guide holes.

[0018] Preferably, the bottom of the extension groove is designed as an inclined surface, and the bottom of the extension groove and the positioning groove are connected to each other through an inclined groove.

[0019] A method for machining pin holes in a steam turbine rotor fork-type impeller, the method using the aforementioned drilling jig for the pin holes in the steam turbine rotor fork-type impeller, includes the following steps:

[0020] S100. Place the impeller on the outside of the central column and the surface of the support plate. Drive the control wheel to rotate through the handwheel. The protrusion gradually squeezes the arc block, forcing the arc block to push the top block outward along the slide groove through the connecting rod and abut against the inner ring of the impeller, thereby achieving radial clamping and fixing of the impeller.

[0021] S200: The hydraulic cylinder drives the pressure plate to move downward, so that the pressure plate is tightly attached to the impeller surface to achieve axial fixation. The movable sleeve slides on the annular guide rail to adjust the drill template to the position of the angle to be processed.

[0022] S300: The drill template is retracted into the movable sleeve by the electric cylinder. The drill sleeve is aligned with the designed position of the impeller pin hole. The positioning block is inserted into the positioning groove, and multiple shims are inserted into the fork-shaped grooves at the edge of the impeller.

[0023] S400: Through the coordinated operation of motor one and motor two, the drill bit is controlled to descend and rotate at the same time, passing through the through grooves of the drill sleeve and the gasket in sequence, and drilling a pin hole at the edge of the impeller.

[0024] S500: During the drilling process, high-pressure airflow is injected into the hollow sleeve through an air pump. The airflow enters each through slot along the hollow sleeve and guide hole, and blows out the generated metal debris through the unblocking hole.

[0025] S600: After part of the airflow enters the extension groove through the through groove, it flows along the inclined surface and the inclined groove to the positioning groove, and in the process of flow, it drives the residual debris in the extension groove to be transferred outward.

[0026] The beneficial effects of this invention are as follows:

[0027] 1. The present invention discloses a drilling jig and processing method for pin holes of a turbine rotor fork-type impeller. Through the coordinated work of the positioning component and the drilling jig component, it achieves dual precise control of angle and position during the processing of impeller pin holes. It eliminates the need to draw the positioning line of the pin hole on the impeller surface in advance, effectively avoiding the hole position deviation problem caused by manual drawing errors in traditional processing methods. Furthermore, through the flexible cooperation between the movable sleeve and the annular guide rail, after drilling once, the side edge plate, the drilling template, and the movable sleeve as a whole can be rotated to adjust to the next drilling angle. The processing of all pin holes at different angles can be completed continuously without repeatedly disassembling the drilling jig, significantly improving processing efficiency and ensuring that the distance between the pin hole on each pitch circle and the impeller axis is equal.

[0028] 2. The present invention discloses a drilling jig and processing method for a fork-shaped impeller pin hole of a steam turbine rotor. After the impeller is installed on the outside of the central column, the operator can rotate the handwheel to drive the stud to rotate and move axially within the central column, thereby causing the control wheel to descend and rotate synchronously. The protrusion on its side gradually contacts and squeezes the arc-shaped block, forcing the arc-shaped block to push the top block along the slide groove to slide outward of the central column through the connecting rod. After the top block extends, it abuts against the inner ring surface of the impeller, thereby achieving radial clamping and fixing of the impeller. After processing, the handwheel is rotated in the opposite direction to drive the control wheel to move upward. Under the elastic action of the spring, the top block retracts along the slide groove, releasing the radial constraint on the impeller, making it easy to remove the processed impeller from the central column. This structural design realizes the rapid clamping and disassembly of the impeller through mechanical transmission, and can automatically adapt to impellers with different inner diameters by utilizing the displacement stroke of the top block in the slide groove.

[0029] 3. The present invention relates to a drilling jig and processing method for a fork-shaped impeller pin hole of a steam turbine rotor. After the hydraulic cylinder drives the pressure plate to press down onto the impeller surface, the drilling jig is adjusted to the angle to be processed. Then, the electric cylinder drives the drilling jig to retract into the movable sleeve. At this time, the drill sleeve and the designed position of the impeller pin hole are exactly aligned, and the positioning block at the lower end of the side plate is inserted into the corresponding positioning groove to achieve circumferential positioning of the drilling jig and prevent the drilling jig from swinging during the drilling process. In addition, during the movement of the side plate toward the impeller, multiple shims are simultaneously inserted into the fork-shaped grooves at the edge of the impeller. These shims not only provide auxiliary support for the impeller, but the tight fit between the shims and the fork-shaped grooves enhances the stability of the overall structure, making the drilling process more stable and reliable. This avoids deformation of the impeller fork-shaped grooves due to force during drilling. Furthermore, the through grooves opened on its surface provide precise guidance for the drill bit, ensuring that the drill bit always maintains the correct feed direction when passing through the shims, further improving the positional accuracy of the pin hole processing. Attached Figure Description

[0030] The invention will now be further described with reference to the accompanying drawings.

[0031] Figure 1 This is a perspective view of the present invention;

[0032] Figure 2 yes Figure 1 Enlarged view of a portion of point A in the middle;

[0033] Figure 3 This is a schematic diagram of the structure of the pressure plate and support plate in this invention;

[0034] Figure 4 This is a schematic diagram of the drill template in this invention;

[0035] Figure 5 This is a schematic diagram of the drill bit structure in this invention;

[0036] Figure 6 This is a schematic diagram of the structure of the support disk and the central column in this invention;

[0037] Figure 7 This is a schematic diagram of the control wheel and top block in this invention;

[0038] Figure 8 This is a cross-sectional view of the present invention;

[0039] Figure 9 yes Figure 8 Enlarged view of a section at point B in the middle;

[0040] Figure 10 yes Figure 8 Enlarged view of a section at point C;

[0041] Figure 11 This is a schematic diagram of the method flow of the present invention.

[0042] In the diagram: 1. Workbench; 2. Central column; 3. Support; 4. Impeller; 5. Pressure plate; 6. Hydraulic cylinder; 7. Movable sleeve; 8. Drill template; 9. Side edge plate; 10. Drill sleeve; 11. Circular guide rail; 12. Control wheel; 13. Protrusion; 14. Handwheel; 15. Stud; 16. Slide groove; 17. Top block; 18. Spring; 19. Arc block; 20. Support plate; 21. Positioning groove; 22. Extension groove; 23. Positioning block; 24. Electric cylinder; 25. Shim; 26. Through groove; 27. Lifting plate; 28. Guide column; 29. ​​Rack; 30. Lifting gear; 31. Motor 1; 32. Motor 2; 33. Drill bit; 34. Drilling gear; 35. Unblocking hole; 36. Air pump; 37. Hollow sleeve; 38. Guide hole; 39. Inclined groove. Detailed Implementation

[0043] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0044] like Figures 1 to 10 As shown, the present invention provides a drilling jig for a turbine rotor fork-type impeller pin hole, comprising a worktable 1, a positioning assembly, and a drilling jig assembly.

[0045] A central column 2 and a bracket 3 are fixedly connected to the surface of the workbench 1; the central column 2 is used to install the impeller 4.

[0046] The positioning component is disposed on the surface of the workbench 1 and is used to accurately position the drilling angle of the impeller 4;

[0047] The drill jig assembly is disposed between the workbench 1 and the support 3 and is used to determine the drilling position for a single angle; the drill jig assembly includes a pressure plate 5, a hydraulic cylinder 6, a movable sleeve 7, a drill template 8, a side plate 9, a drill sleeve 10, and a drilling mechanism.

[0048] A hydraulic cylinder 6 is connected between the pressure plate 5 and the bracket 3; an annular guide rail 11 is provided on the side of the pressure plate 5; a movable sleeve 7 is slidably connected on the annular guide rail 11; a drill template 8 is slidably connected inside the movable sleeve 7; a side plate 9 is fixedly connected to the end of the drill template 8; a set of drill sleeves 10 are evenly distributed on the surface of the drill template 8; a drilling mechanism is provided on the drill template 8; the drilling mechanism is used to process pin holes for the impeller 4 along the drill sleeves 10.

[0049] In operation, the turbine rotor fork-shaped impeller 4 is first installed on the outside of the central column 2. Then, the hydraulic cylinder 6 is activated to push the pressure plate 5 downward, so that the pressure plate 5 fits tightly against the surface of the impeller 4 to achieve axial fixation. Next, according to the processing requirements, the movable sleeve 7 slides on the annular guide rail 11 to adjust the drill template 8 to the angle to be processed, so that the drill sleeve 10 is precisely aligned with the target processing area at the edge of the impeller 4. Then, the pin hole is processed on the impeller 4 by the drilling mechanism along the guide of the drill sleeve 10.

[0050] This invention achieves precise control of both angle and position during the pin hole machining process of the impeller 4 through the coordinated operation of the positioning component and the drilling jig component. It eliminates the need to pre-draw the positioning lines for the pin holes on the surface of the impeller 4, effectively avoiding the hole position deviation problem caused by manual drawing errors in traditional machining methods. Furthermore, through the flexible cooperation between the movable sleeve 7 and the annular guide rail 11, after drilling once, the side edge plate 9, the drilling template 8, and the movable sleeve 7 as a whole can be rotated to adjust to the next drilling angle. The machining of all pin holes at different angles can be completed continuously without repeatedly disassembling the drilling jig, significantly improving machining efficiency and ensuring that the distance between the pin holes on each pitch circle and the axis of the impeller 4 is equal.

[0051] In one embodiment of the present invention, a control wheel 12 is provided inside the central column 2; a set of protrusions 13 are evenly distributed on the side of the control wheel 12; a handwheel 14 is provided on the top of the central column 2; a stud 15 is fixedly connected between the handwheel 14 and the control wheel 12; the stud 15 and the central column 2 are threadedly engaged; a set of sliding grooves 16 are evenly distributed on the side of the central column 2; a top block 17 is slidably connected inside the sliding groove 16; a spring 18 is fixedly connected between the top block 17 and the sliding groove 16; a connecting rod is fixedly connected to the surface of the top block 17; an arc-shaped block 19 is fixedly connected to one end of the connecting rod extending to the control wheel 12.

[0052] After the impeller 4 is installed on the outside of the central column 2, the operator can turn the handwheel 14 to drive the stud 15 to rotate and move axially within the central column 2, thereby causing the control wheel 12 to descend and rotate synchronously. The protrusion 13 on its side gradually contacts and presses the arc-shaped block 19, forcing the arc-shaped block 19 to push the top block 17 along the slide groove 16 to slide outward from the central column 2 via the connecting rod. After the top block 17 extends outward, it abuts against the inner ring surface of the impeller 4, thereby achieving radial clamping and fixing of the impeller 4. After processing, the handwheel 14 is turned in the opposite direction to drive the control wheel 12 to move upward. Under the elastic action of the spring 18, the top block 17 retracts along the slide groove 16, releasing the radial constraint on the impeller 4, making it easy to remove the processed impeller 4 from the central column 2. This structural design realizes the quick clamping and disassembly of the impeller 4 through mechanical transmission, and the displacement stroke of the top block 17 in the slide groove 16 can automatically adapt to impellers 4 with different inner diameters.

[0053] In one embodiment of the present invention, the positioning component includes a support plate 20; a set of positioning grooves 21 are evenly distributed on the side of the support plate 20, the number of positioning grooves 21 being determined according to the number of pin holes on a single segment circle; a set of extension grooves 22 are evenly distributed on the upper side of the support plate 20, the extension grooves 22 corresponding one-to-one with the positioning grooves 21; a positioning block 23 is fixedly connected to the lower end of the side edge plate 9; an electric cylinder 24 is connected between the drill template 8 and the movable sleeve 7; a set of gaskets 25 are evenly distributed on the bottom of the side edge plate 9, the number of gaskets 25 being the same as the number of fork-shaped grooves at the edge of the impeller 4; a set of through grooves 26 are opened on the surface of the gaskets 25 at the corresponding positions of the drill sleeve 10.

[0054] Initially, the drill template 8 and the movable sleeve 7 are in an extended state. After the hydraulic cylinder 6 drives the pressure plate 5 to press down onto the surface of the impeller 4, the drill template 8 is adjusted to the angle to be processed. Then, the electric cylinder 24 drives the drill template 8 to retract into the movable sleeve 7. At this time, the drill sleeve 10 and the pin hole of the impeller 4 are exactly aligned, and the positioning block 23 at the lower end of the side plate 9 is inserted into the corresponding positioning groove 21 to achieve circumferential positioning of the drill template 8 and prevent the drill template 8 from swinging during the drilling process. In addition, as the side plate 9 moves towards the impeller 4... Simultaneously, multiple shims 25 are inserted into the forked grooves at the edge of the impeller 4. These shims 25 not only provide auxiliary support for the impeller 4, but the close fit between the shims 25 and the forked grooves enhances the stability of the overall structure, making the drilling process more stable and reliable. This prevents the forked grooves of the impeller 4 from deforming due to force during drilling. Furthermore, the through grooves 26 on their surfaces provide precise guidance for the drill bit 33, ensuring that the drill bit 33 always maintains the correct feed direction when passing through the shims 25, further improving the positional accuracy of the pin hole machining.

[0055] In one embodiment of the present invention, the drilling mechanism includes a lifting plate 27; one end of the lifting plate 27 is slidably connected to a side edge plate 9; a guide post 28 is fixedly connected to the surface of the drill template 8, and the guide post 28 passes through the lifting plate 27 and is slidably connected to it; a rack 29 is provided on the surface of the guide post 28; a lifting gear 30 is rotatably connected inside the lifting plate 27, and the lifting gear 30 meshes with the rack 29; a motor 31 is coaxially connected to the lifting gear 30; a second motor 32 is fixedly connected to the surface of the lifting plate 27; a set of drill bits 33 are driven by the second motor 32, and the number of drill bits 33 facing the drill sleeve 10 is the same as the number of drill sleeves 10.

[0056] Each drill bit 33 has a drilling gear 34 connected to its upper end via a connector, and the drilling gears 34 mesh with each other; one of the drilling gears 34 is coaxially connected to the motor 32.

[0057] When motor 31 starts, its output shaft drives the lifting gear 30 to rotate. Since the lifting gear 30 meshes with the rack 29 on the surface of the guide post 28, the lifting plate 27 can move up and down along the guide post 28 and the side plate 9, thereby adjusting the vertical distance between the drill bit 33 and the impeller 4. During this process, motor 32 drives the drill bit 33 to rotate to realize the drilling operation. The drill bit 33 moves downward and passes through the through groove 26 of the drill sleeve 10 and the shim 25 in sequence, drilling a pin hole at the edge of the impeller 4. When motor 32 drives one of the drill bits 33 to rotate, the meshing action between the drilling gears 34 can control multiple drill bits 33 to rotate synchronously, thereby realizing the simultaneous processing of multiple pin holes at the same angle. This not only greatly improves the efficiency of pin hole processing, but also, since the drill bits 33 are linked together through the drilling gears 34, the relative positional accuracy between multiple pin holes can be effectively guaranteed, avoiding the accumulation of errors caused by individual processing.

[0058] In one embodiment of the present invention, a dredging hole 35 is provided between the side of the gasket 25 and each through groove 26. These dredging holes 35 allow metal debris generated during drilling operations to be discharged from the through groove 26 in a timely manner, preventing debris from accumulating in the through groove 26 and affecting the normal feed and drilling accuracy of the drill bit 33. Simultaneously, the dredging holes 35 also provide some heat dissipation, preventing the drill bit 33 from experiencing excessively high local temperatures during high-speed rotation and metal friction, thus ensuring the continuity and stability of the drilling operation.

[0059] In one embodiment of the present invention, an air pump 36 and a hollow sleeve 37 are fixedly connected to the bottom of the side plate 9; the hollow sleeve 37 and each through slot 26 are interconnected through guide holes 38.

[0060] During the drilling process, high-pressure airflow is injected into the hollow sleeve 37 via the air pump 36. The airflow enters the various through slots 26 along the hollow sleeve 37 and the guide hole 38, powerfully blowing away the debris attached to the surface of the drill bit 33 and the debris inside the through slots 26. The debris is then blown out laterally through the unblocking hole 35, further improving the debris removal effect. At the same time, the airflow can accelerate the heat dissipation of the drill bit 33 as it flows around it. Together with the unblocking hole 35, the drill bit 33 is kept at a suitable temperature. In addition, the continuous flow of gas can also play a certain role in cooling and protecting the drilling area of ​​the impeller 4 during the drilling process, reducing material deformation caused by high temperature.

[0061] The bottom of the extension groove 22 is designed as an inclined surface, and the bottom of the extension groove 22 and the positioning groove 21 are connected to each other through the inclined groove 39.

[0062] The inclined structure allows debris scattered into the extension groove 22 during drilling to slide towards the inclined groove 39 under the action of gravity. The inclined groove 39 can then smoothly guide these debris into the positioning groove 21 for centralized collection, preventing debris from accumulating in the extension groove 22 and affecting the normal operation of the device. At the same time, this interconnected design also allows some of the airflow generated by the air pump 36 to enter the extension groove 22 through the through groove 26 and then flow along the inclined surface and inclined groove 39 towards the positioning groove 21. During the flow process, it further drives the movement of residual debris, improving the overall thoroughness of debris cleaning and ensuring that each component can maintain a good working condition after long-term operation.

[0063] like Figure 11 As shown, the present invention discloses a method for machining pin holes in a steam turbine rotor fork-shaped impeller. This method uses the aforementioned drilling jig for the pin holes in the steam turbine rotor fork-shaped impeller and includes the following steps:

[0064] S100. Place the impeller 4 on the outside of the central column 2 and the surface of the support plate 20. Drive the control wheel 12 to rotate through the handwheel 14. The protrusion 13 gradually squeezes the arc block 19, forcing the arc block 19 to push the top block 17 outward along the slide groove 16 through the connecting rod and abut against the inner ring of the impeller 4, thereby achieving radial clamping and fixing of the impeller 4.

[0065] S200: The hydraulic cylinder 6 drives the pressure plate 5 to move downward, so that the pressure plate 5 is tightly attached to the surface of the impeller 4 to achieve axial fixation. The movable sleeve 7 slides on the annular guide rail 11 to adjust the drill template 8 to the position of the angle to be processed.

[0066] S300, the electric cylinder 24 drives the drill template 8 to retract into the movable sleeve 7, the drill sleeve 10 is aligned with the designed position of the pin hole of the impeller 4, the positioning block 23 is inserted into the positioning groove 21, and multiple shims 25 are inserted into the forked grooves at the edge of the impeller 4.

[0067] S400. Through the coordinated operation of motor 1 31 and motor 2 32, the drill bit 33 is controlled to descend and rotate at the same time, passing through the through groove 26 of drill sleeve 10 and shim 25 in sequence, and drilling a pin hole at the edge of impeller 4.

[0068] S500. During the drilling process, high-pressure airflow is injected into the hollow sleeve 37 through the air pump 36. The airflow enters each through groove 26 along the hollow sleeve 37 and the guide hole 38, and blows out the generated metal debris through the unblocking hole 35.

[0069] S600, after part of the airflow enters the extension groove 22 through the through groove 26, it flows along the inclined surface and inclined groove 39 to the positioning groove 21, and in the process of flow, it drives the residual debris in the extension groove 22 to be transferred outward.

[0070] The terms "front," "back," "left," "right," "top," and "bottom" all refer to the figures in the accompanying drawings. Figure 1Based on the perspective of the observer, the side of the device facing the observer is defined as the front, the left side of the observer is defined as the left, and so on.

[0071] In the description of this invention, it should be understood that the terms "center", "longitudinal", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this invention.

[0072] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A drilling jig for the pin hole of a fork-shaped impeller of a steam turbine rotor, characterized in that: Includes a worktable (1), a positioning assembly, and a drill jig assembly; The workbench (1) is fixedly connected to a central column (2) and a bracket (3); the central column (2) is used to install an impeller (4); The positioning component is disposed on the surface of the workbench (1) and is used to accurately position the drilling angle of the impeller (4); The drill jig assembly is disposed between the workbench (1) and the support (3) and is used to determine the drilling position for a single angle; the drill jig assembly includes a pressure plate (5), a hydraulic cylinder (6), a movable sleeve (7), a drill template (8), a side plate (9), a drill sleeve (10), and a drilling mechanism; A hydraulic cylinder (6) is connected between the pressure plate (5) and the bracket (3); an annular guide rail (11) is provided on the side of the pressure plate (5); a movable sleeve (7) is slidably connected on the annular guide rail (11); a drill template (8) is slidably connected inside the movable sleeve (7); a side plate (9) is fixedly connected to the end of the drill template (8); a set of drill sleeves (10) are evenly distributed on the surface of the drill template (8); a drilling mechanism is provided on the drill template (8); the drilling mechanism is used to process pin holes for the impeller (4) along the drill sleeves (10); The positioning component includes a support plate (20); a set of positioning grooves (21) are evenly distributed on the side of the support plate (20); a set of extension grooves (22) are evenly distributed on the upper side of the support plate (20); a positioning block (23) is fixedly connected to the lower end of the side plate (9); an electric cylinder (24) is connected between the drill template (8) and the movable sleeve (7); a set of gaskets (25) are evenly distributed on the bottom of the side plate (9); a set of through grooves (26) are opened on the surface of the gaskets (25).

2. The drilling jig for the pin hole of a steam turbine rotor fork-type impeller according to claim 1, characterized in that: The central column (2) is equipped with a control wheel (12); a set of protrusions (13) are evenly distributed on the side of the control wheel (12); a handwheel (14) is provided on the top of the central column (2); a stud (15) is fixedly connected between the handwheel (14) and the control wheel (12); a set of sliding grooves (16) are evenly distributed on the side of the central column (2); a top block (17) is slidably connected inside the sliding groove (16); a spring (18) is fixedly connected between the top block (17) and the sliding groove (16); a connecting rod is fixedly connected to the surface of the top block (17); an arc-shaped block (19) is fixedly connected to one end of the connecting rod extending to the control wheel (12).

3. The drilling jig for the pin hole of a steam turbine rotor fork-type impeller according to claim 1, characterized in that: The drilling mechanism includes a lifting plate (27); one end of the lifting plate (27) is slidably connected to the side edge plate (9); a guide post (28) is fixedly connected to the surface of the drill template (8), and the guide post (28) passes through the lifting plate (27) and is slidably connected to it; a rack (29) is provided on the surface of the guide post (28); a lifting gear (30) is rotatably connected inside the lifting plate (27), and the lifting gear (30) meshes with the rack (29); a motor (31) is coaxially connected to the lifting gear (30); a second motor (32) is fixedly connected to the surface of the lifting plate (27); a set of drill bits (33) is driven by the second motor (32).

4. The drilling jig for the pin hole of a steam turbine rotor fork-type impeller according to claim 3, characterized in that: The upper end of each drill bit (33) is connected to a drilling gear (34) via a connector, and the drilling gears (34) mesh with each other; one of the drilling gears (34) is coaxially connected to the second motor (32).

5. The drilling jig for the pin hole of a steam turbine rotor fork-type impeller according to claim 1, characterized in that: The gasket (25) has a dredging hole (35) between its side and each through groove (26).

6. The drilling jig for the pin hole of a steam turbine rotor fork-type impeller according to claim 5, characterized in that: The bottom of the side plate (9) is fixedly connected to an air pump (36) and a hollow sleeve (37); the hollow sleeve (37) and each through slot (26) are interconnected through guide holes (38).

7. The drilling jig for the pin hole of a steam turbine rotor fork-type impeller according to claim 6, characterized in that: The bottom of the extension groove (22) is designed as an inclined surface, and the bottom of the extension groove (22) and the positioning groove (21) are connected to each other through the inclined groove (39).

8. A method for machining pin holes in a steam turbine rotor fork-shaped impeller, the method employing the drilling jig for the pin holes in a steam turbine rotor fork-shaped impeller as described in any one of claims 1-7, characterized in that: Includes the following steps: S100. Place the impeller (4) on the outside of the central column (2) and the surface of the support plate (20). Drive the control wheel (12) to rotate through the handwheel (14). The protrusion (13) gradually squeezes the arc block (19), forcing the arc block (19) to push the top block (17) outward along the slide groove (16) through the connecting rod and abut against the inner ring of the impeller (4), thereby achieving radial clamping and fixing of the impeller (4). S200. The hydraulic cylinder (6) drives the pressure plate (5) to move downward, so that the pressure plate (5) fits tightly against the surface of the impeller (4) to achieve axial fixation. The movable sleeve (7) slides on the annular guide rail (11) to adjust the drill template (8) to the position of the angle to be processed. S300, the drill template (8) is driven to retract into the movable sleeve (7) by the electric cylinder (24), the drill sleeve (10) is aligned with the designed position of the pin hole of the impeller (4), the positioning block (23) is inserted into the positioning groove (21), and multiple shims (25) are inserted into the fork-shaped grooves at the edge of the impeller (4); S400. Through the coordinated operation of motor one (31) and motor two (32), the drill bit (33) is controlled to descend and rotate at the same time, passing through the through groove (26) of the drill sleeve (10) and the gasket (25) in sequence, and drilling a pin hole at the edge of the impeller (4).

9. A method for machining pin holes in a steam turbine rotor fork-type impeller according to claim 8, characterized in that: It also includes the following steps: S500. During the drilling process, high-pressure airflow is injected into the hollow sleeve (37) through the air pump (36). The airflow enters each through groove (26) along the hollow sleeve (37) and the guide hole (38), and blows out the generated metal debris through the unblocking hole (35) to the side. S600. After part of the airflow enters the extension groove (22) through the through groove (26), it flows along the inclined surface and the inclined groove (39) to the positioning groove (21). During the flow, it drives the residual debris in the extension groove (22) to be transferred outward.

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