A drill jig for processing steam balance hole of steam turbine rotor

Abstract

The application belongs to the technical field of steam turbine rotor processing, in particular to a drill jig for steam turbine rotor steam balance hole processing, which comprises a drill jig body, a bushing, a quick-change drill sleeve, a cylindrical pin and a set screw; the drill jig body is provided with a rectangular groove in the thickness direction; both sides of the bottom of the drill jig body are provided with through holes; the bushing is fixedly connected to the inside of one side of the through hole; the inside of the bushing is provided with the quick-change drill sleeve. The drill jig body with a "door" type structure is matched with the rectangular groove, which can quickly realize the preliminary positioning of the drill jig at the edge of the impeller, the radially limiting of the outer circle of the impeller is matched with the symmetrical distribution of the cylindrical pin, the center of the quick-change drill sleeve is accurately aligned with the positioning line, and the hole position deviation problem caused by the positioning deviation in the traditional processing is avoided; at the same time, the set screw at the bottom is stably pressed against the surface of the impeller spoke through the threaded connection, so that the drill jig can remain stable during the drilling process and prevent displacement caused by vibration.

Description

Technical Field

[0001] This invention belongs to the field of steam turbine rotor processing technology, specifically a drilling jig for processing steam balance holes in a steam turbine rotor. Background Technology

[0002] The turbine rotor is the core component of a steam turbine, its main function being to convert the thermal energy of steam into mechanical energy. Steam balance holes are formed on the turbine rotor impeller, primarily to reduce the steam pressure difference across the impeller, thereby reducing excessive axial force generated by the rotor. Typically, 5-7 steam balance holes with a diameter of 50 mm or more are evenly distributed on the same pitch circle on different stages of the impeller of a single turbine rotor.

[0003] Chinese patent application CN102941370A discloses a method for machining steam balance holes in a steam turbine rotor impeller. The key technical points are: first, align the drill bit with the steam balance hole location of the first rotor impeller to be machined; install the steam balance hole drill jig; begin machining the steam balance holes of the rotor impellers until all steam balance holes of the rotor impellers within the reach of the drill bit's stroke are machined; install a connecting rod between the drill bit and the tail shank; continue machining the remaining steam balance holes of the rotor impellers; withdraw the directional drill and align the drill bit with the steam balance hole location of the next rotor impeller to be machined, until all steam balance holes of the rotor impellers are machined. This technology is applicable to the machining of steam balance holes in rotor impellers.

[0004] However, the above technology has the following drawbacks: since the steam balance hole is opened on the impeller spoke, and the impeller spoke is a curved surface, it is easy to deviate during drilling, which will cause the steam balance hole of the subsequent impeller to deviate even more, resulting in steam balance hole processing quality problems.

[0005] Therefore, the present invention provides a drilling jig for machining steam balance holes in 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 drill jig for machining steam balance holes of a steam turbine rotor, comprising a drill jig body, a bushing, a quick-change drill bushing, a cylindrical pin and a fastener;

[0008] The drill jig body has a rectangular groove in the thickness direction; through holes are provided on both sides of the bottom of the drill jig body;

[0009] The bushing is fixedly connected to the inside of the through hole on one side; a quick-change drill bushing is provided inside the bushing;

[0010] Two cylindrical pins are provided and located at the top of the drill jig body;

[0011] Two fasteners are provided and located on one side of the bottom of the drill jig body; the fasteners penetrate the side wall of the drill jig body and are connected to it by threads.

[0012] Preferably, the drill jig body is provided in a set, and each drill jig body has a mating sleeve and a mating column fixedly connected to both sides respectively; a guide block is fixedly connected to the end of the mating column.

[0013] Preferably, a dovetail groove is provided on one side of the fitting sleeve.

[0014] Preferably, it further includes two mounting ring seats, which are disposed on both sides of a set of drill jig bodies; an annular groove is formed on the outer periphery of the mounting ring seat; a movable seat is slidably connected inside the annular groove; the movable seat is fixedly connected to one of the drill jig bodies by a support arm; a reinforcing member is provided on the surface of the movable seat, and the reinforcing member passes through the movable seat and is connected to it by a thread.

[0015] Preferably, the mounting ring seat is designed as a split structure, with the two halves of the mounting ring seat being fixed together by bolts.

[0016] Preferably, a sliding plate is slidably connected to the top of the drill jig, and a cylindrical pin is located inside the sliding plate; an adjusting column is rotatably connected to the top of the sliding plate; the adjusting column passes through the top of the drill jig and is connected to it by a thread.

[0017] Preferably, a pin shaft is fixedly connected inside the cylindrical pin; guide grooves are provided on both sides of the drill jig body; the two ends of the pin shaft pass through the slide plate and the guide groove, and the pin shaft is rotatably connected to the slide plate.

[0018] Preferably, a support plate is fixedly connected to the bottom of one of the drill jig bodies near the mounting ring seat; an arc-shaped guide rail is fixedly connected to the surface of the support plate; a centering plate is slidably connected to the surface of the guide rail; a clamping element is provided between the centering plate and the guide rail; a drawing assembly is provided on the surface of the centering plate; the drawing assembly is used to draw the positioning lines of the balance holes on the impeller surface.

[0019] Preferably, an arc-shaped indicator strip is fixedly connected to the surface of the support plate; the surface of the indicator strip is provided with scale values; and a pointer is fixedly connected to one end of the centering plate near the indicator strip.

[0020] Preferably, the line drawing assembly includes a line drawing plate; a spring is fixedly connected between the line drawing plate and the centering plate; a push rod is fixedly connected to one side of the line drawing plate, and the push rod is slidably connected to the centering plate; an X-shaped dyeing strip is provided on the other side of the line drawing plate; the surface of the dyeing strip is coated with dye.

[0021] The beneficial effects of this invention are as follows:

[0022] 1. The present invention discloses a drill jig for machining steam balance holes on a steam turbine rotor. By employing a "gate"-shaped drill jig body in conjunction with a rectangular groove, the drill jig can quickly achieve initial positioning at the impeller edge. Symmetrically distributed cylindrical pins radially limit the outer circle of the impeller, ensuring precise alignment of the center of the quick-change drill sleeve with the positioning line, thus avoiding hole position offset problems caused by positioning deviations in traditional machining. Simultaneously, the bottom fastener, connected by threads, stably presses against the impeller spoke surface, keeping the drill jig stable during drilling and preventing displacement due to vibration. The design of the drill bit entering through the quick-change drill sleeve and exiting through a through-hole forms a through-processing channel, further ensuring the straightness of the drill hole. This significantly improves the machining accuracy and consistency of the steam balance holes on the steam turbine rotor, reducing component fit problems caused by hole position errors during subsequent assembly.

[0023] 2. The present invention discloses a drilling jig for machining steam balance holes on a steam turbine rotor. Multiple interconnected drilling jig bodies are respectively clamped at the edges of each impeller. The mating column and guide block of the preceding drilling jig body can slide inside the mating sleeve of the following drilling jig body, adaptively adjusting the distance between adjacent impellers. During drilling, the drill bit only needs to pass through the quick-change drill sleeve and through hole of the first drilling jig body to smoothly pass through all subsequent drilling jig bodies, thus gradually drilling balance holes on all impeller surfaces. All balance holes are on the same straight line, eliminating the need for repeated loading and unloading of drilling jig bodies and determination of reference points for multiple impellers, significantly shortening the auxiliary time for drilling jig installation. Simultaneously, when multiple drilling jig bodies work together, their overall rigidity is improved, further reducing deformation and errors during machining, ensuring that the relative positional accuracy of all impeller steam balance holes meets design requirements.

[0024] 3. The present invention discloses a drilling jig for machining steam balance holes on a steam turbine rotor. Two mounting ring seats are respectively fitted onto both ends of the steam turbine rotor. After completing one continuous drilling operation, the fastening screws of each drilling jig body are loosened. Then, the movable seat is controlled to rotate a certain angle inside the annular groove, driving the support arm and multiple drilling jig bodies to rotate to a specific angle. This angle is determined according to the included angle between adjacent balance holes. Then, the fastener is tightened so that its end is pressed against the surface of the annular groove, thereby fixing the movable seat and the mounting ring seats. Then, balance hole drilling operations at this angle can be performed. Repeating the above method can complete the machining operation of all balance holes in the circumferential direction. This design not only realizes the flexible adjustment of the drilling jig body in the circumferential direction of the impeller, but also, through the coaxial setting of the mounting ring seats and the rotor, further ensures the parallelism of the entire drilling jig body with the rotor centerline, ensuring that the distance between multiple balance holes and the centerline is equal. Attached Figure Description

[0025] The invention will now be further described with reference to the accompanying drawings.

[0026] Figure 1 This is a schematic diagram of the installation of the present invention relative to the turbine rotor;

[0027] Figure 2 yes Figure 1 Enlarged view of a portion of point A in the middle;

[0028] Figure 3 This is a schematic diagram of the arrangement of the drill jig bodies in this invention;

[0029] Figure 4 This is a schematic diagram of the structure of the drill jig body and the mounting ring seat in this invention;

[0030] Figure 5 This is a schematic diagram of the drill jig body in this invention;

[0031] Figure 6 This is a schematic diagram of the core plate structure in this invention;

[0032] Figure 7 This is a front view of the present invention;

[0033] Figure 8 This is a cross-sectional view of the drill jig body in this invention.

[0034] In the diagram: 1. Drill jig body; 2. Bushing; 3. Quick-change drill bushing; 4. Cylindrical pin; 5. Fastener; 6. Through hole; 7. Mating sleeve; 8. Mating column; 9. Guide block; 10. Dovetail groove; 11. Mounting ring seat; 12. Annular groove; 13. Movable seat; 14. Support arm; 15. Reinforcing member; 16. Slide plate; 17. Adjusting column; 18. Pin; 19. Guide groove; 20. Support plate; 21. Guide rail; 22. Alignment plate; 23. Clamping member; 24. Indicator bar; 25. Pointer; 26. Marking plate; 27. Push rod; 28. Dyeing strip. Detailed Implementation

[0035] 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.

[0036] like Figures 1 to 8 As shown, the present invention provides a drill jig for machining steam balance holes on a steam turbine rotor, comprising a drill jig body 1, a bushing 2, a quick-change drill sleeve 3, a cylindrical pin 4, and a fastening component 5.

[0037] The drill jig body 1 has a rectangular groove in the thickness direction, the width of which is 5 mm larger than the thickness of the turbine rotor impeller. The drill jig body 1 has a "gate" shaped structure in the thickness direction. Through holes 6 are provided on both sides of the bottom of the drill jig body 1.

[0038] The bushing 2 is fixedly connected to the inside of the through hole 6 on one side; a quick-change drill sleeve 3 is provided inside the bushing 2;

[0039] Two cylindrical pins 4 are provided and located at the top of the drill jig body 1. The two cylindrical pins 4 are symmetrically distributed about the steam balance hole of the turbine rotor.

[0040] The setter 5 is specifically a set screw. There are two setters 5 located on one side of the bottom of the drill jig body 1. The setter 5 penetrates the side wall of the drill jig body 1 and is connected to it by threads.

[0041] Before machining the steam balance holes of the turbine rotor, this invention first draws the positioning line of the steam balance hole on the impeller end face. Then, the rectangular groove of the drill jig 1 is clamped at the edge of the turbine rotor impeller, so that the cylindrical pin 4 rests against the outer circle of the impeller, which plays a radial positioning role of the drill jig 1. The center of the quick-change drill sleeve 3 is aligned with the pre-drawn positioning line of the balance hole. The fastener 5 at the bottom of the drill jig 1 is tightened so that the end of the fastener 5 is pressed against the impeller spoke surface. Then, the steam balance hole of the turbine rotor is drilled using a horizontal boring machine. The drill bit enters from the quick-change drill sleeve 3 on one side, drills a hole on the impeller surface, and exits through the through hole 6 on the other side. This effectively prevents the problem of skewness when machining the steam balance hole of the turbine rotor. Since the steam balance hole of the first impeller is machined accurately, it ensures that the steam balance hole of other impellers in the subsequent stages will not be skewed, thus ensuring the machining quality of the steam balance hole of the turbine rotor.

[0042] This invention employs a "gate"-shaped drill jig body 1 that mates with a rectangular groove, enabling rapid initial positioning of the drill jig at the impeller edge. Symmetrically distributed cylindrical pins 4 radially limit the outer circle of the impeller, ensuring precise alignment of the center of the quick-change drill sleeve 3 with the positioning line, thus avoiding hole position offset problems caused by positioning deviations in traditional machining. Simultaneously, the bottom locking member 5, connected by threads, stably presses against the impeller spoke surface, keeping the drill jig stable during drilling and preventing displacement due to vibration. The design of the drill bit entering through the quick-change drill sleeve 3 and exiting through the through hole 6 forms a through-processing channel, further ensuring the straightness of the drill hole. This significantly improves the machining accuracy and consistency of the steam balance holes on the turbine rotor, reducing component fit problems caused by hole position errors during subsequent assembly.

[0043] In one embodiment of the present invention, the drill jig body 1 is provided in a set, and the quick-change drill sleeves 3 and through holes 6 of the multiple drill jig bodies 1 are all located on the same straight line; each drill jig body 1 is fixedly connected to a mating sleeve 7 and a mating column 8 on both sides; the number of drill jig bodies 1 is the same as the number of impellers of the steam turbine rotor; a guide block 9 is fixedly connected to the end of the mating column 8.

[0044] To continuously and simultaneously drill multiple impellers on the same rotor, this invention uses multiple interconnected drill jigs 1, each secured to the edge of an impeller. The mating column 8 and guide block 9 of the preceding drill jig 1 can slide inside the mating sleeve 7 of the following drill jig 1, adaptively adjusting the distance between adjacent impellers. During drilling, the drill bit only needs to pass through the quick-change drill sleeve 3 and through hole 6 of the first drill jig 1 to smoothly pass through all subsequent drill jigs 1, thus gradually drilling balance holes on all impeller surfaces. All balance holes are on the same straight line, eliminating the need to repeatedly install and remove drill jigs 1 for multiple impellers and determine the reference, significantly shortening the auxiliary time for drill jig installation. At the same time, when multiple drill jigs 1 work together, their overall rigidity is improved, further reducing deformation and errors during processing, ensuring that the relative positional accuracy of all impeller steam balance holes meets design requirements.

[0045] The aforementioned drilling operations involve continuous long-distance drilling and drill bit extension connections. Detailed operations can be performed using the equipment and methods disclosed in CN102941370A - Steam Turbine Rotor Impeller Steam Balance Hole Machining Method.

[0046] The mating sleeve 7 has a dovetail groove 10 on one side. The number of drill jig bodies 1 can be freely spliced ​​according to the number of impellers. During splicing, the mating column 8 and guide block 9 are laterally aligned and inserted into the dovetail groove 10 of the mating sleeve 7, so that the mating column 8 and guide block 9 are completely inserted into the mating sleeve 7, thus completing the assembly between adjacent drill jig bodies 1. Subsequently, when the mating column 8 and guide block 9 slide axially inside the mating sleeve 7, they cannot be dislodged through the dovetail groove 10.

[0047] In one embodiment of the present invention, two mounting ring seats 11 are further included, which are disposed on both sides of a set of drill jig bodies 1. The axis of the mounting ring seat 11 coincides with the center line of the turbine rotor. An annular groove 12 is formed on the outer periphery of the mounting ring seat 11. A movable seat 13 is slidably connected inside the annular groove 12. The movable seat 13 is fixedly connected to one of the drill jig bodies 1 by a support arm 14. A reinforcing member 15 is provided on the surface of the movable seat 13. The reinforcing member 15 is specifically a fastening bolt, and the reinforcing member 15 passes through the movable seat 13 and is connected to it by a thread.

[0048] Two mounting ring seats 11 are respectively fitted onto both ends of the turbine rotor. After completing one continuous drilling, the fastening screws of each drill jig body 1 are loosened, and then the movable seat 13 is controlled to rotate a certain angle inside the annular groove 12, driving the support arm 14 and multiple drill jig bodies 1 to rotate to a specific angle. This angle is determined according to the included angle between adjacent balance holes. Then the reinforcing part 15 is tightened so that its end is pressed against the surface of the annular groove 12, thereby fixing the movable seat 13 and the mounting ring seat 11. Then the balance hole drilling operation at this angle can be performed. Repeating the above method can complete the processing operation of all balance holes in the circumferential direction. This design not only realizes the flexible adjustment of the drill jig body 1 in the circumferential direction of the impeller, but also, through the coaxial setting of the mounting ring seat 11 and the rotor, further ensures the parallelism of the drill jig body 1 as a whole with the rotor centerline, ensuring that the distance between multiple balance holes and the centerline is equal.

[0049] The mounting ring seat 11 is designed as a split structure, with the two halves of the mounting ring seat 11 being fixed together by bolts. During installation, the two halves of the mounting ring seat 11 are first attached to both sides of the rotor journal, and after aligning the splicing surfaces, they are tightened with bolts to form a complete ring structure, improving the ease of operation.

[0050] In one embodiment of the present invention, a sliding plate 16 is slidably connected to the top of the drill jig body 1, and a cylindrical pin 4 is located inside the sliding plate 16; an adjusting column 17 is rotatably connected to the top of the sliding plate 16, and the adjusting column 17 is specifically an adjusting stud; the adjusting column 17 passes through the top of the drill jig body 1 and is connected to it by a thread.

[0051] The cylindrical pin 4 is internally fixedly connected to a pin shaft 18; the drill jig body 1 has guide grooves 19 on both sides; the pin shaft 18 passes through the slide plate 16 and the guide grooves 19 at both ends, and the pin shaft 18 is rotatably connected to the slide plate 16.

[0052] By rotating the adjusting column 17, the sliding plate 16 can be moved vertically on the top of the drill jig 1, thereby causing the cylindrical pin 4 to rise and fall synchronously, so as to adapt to different diameters of different impellers. In the process of rotating the movable seat 13, the support arm 14 and the multiple drill jig 1 as a whole, the cylindrical pin 4 can roll on the outer surface of the impeller, without having to adjust the cylindrical pin 4 to a position that does not contact the impeller, thus reducing the complexity of operation.

[0053] In one embodiment of the present invention, a support plate 20 is fixedly connected to the bottom of one of the drill jig bodies 1 near the mounting ring seat 11; an arc-shaped guide rail 21 is fixedly connected to the surface of the support plate 20; a centering plate 22 is slidably connected to the surface of the guide rail 21; a clamping member 23 is provided between the centering plate 22 and the guide rail 21, specifically a clamping screw; a drawing assembly is provided on the surface of the centering plate 22; the drawing assembly is used to draw the positioning lines of the balance holes on the impeller surface.

[0054] An arc-shaped indicator strip 24 is fixedly connected to the surface of the support plate 20; the surface of the indicator strip 24 is provided with scale values; a pointer 25 is fixedly connected to one end of the centering plate 22 near the indicator strip 24.

[0055] The centers of the arc-shaped guide rail 21 and the indicator bar 24 are both located on the rotor centerline. As a result, the center plate 22 always points to the centerline when it moves on the surface of the guide rail 21. During or before and after a continuous drilling operation, the center plate 22 can be controlled to move along the guide rail 21 at a certain angle. This angle depends on the included angle between adjacent balance holes and can be read by the pointer 25 and the scale value. Tightening the clamping member 23 fixes the center plate 22 to the guide rail 21. Then, the positioning line of the next balance hole is drawn on the surface of the first impeller by the drawing assembly on the center plate 22. This design allows a drilling position to be randomly selected when determining the position of the first balance hole, without having to draw the positioning line of the first balance hole in advance. Furthermore, when drilling balance holes at a certain angle, the next balance hole at a certain angle can be drawn and positioned at the same time, thereby gradually completing the drawing and drilling of all balance holes, eliminating the need for manual drawing operations and reducing the uncertainty of manual operations.

[0056] In one embodiment of the present invention, the line drawing assembly includes a line drawing plate 26; a spring is fixedly connected between the line drawing plate 26 and the centering plate 22; a push rod 27 is fixedly connected to one side of the line drawing plate 26, and the push rod 27 is slidably connected to the centering plate 22; an X-shaped dyeing strip 28 is provided on the other side of the line drawing plate 26; the surface of the dyeing strip 28 is coated with a dye.

[0057] When it is necessary to draw lines on the impeller surface, pushing the push rod 27 can move the animation line plate 26 towards the impeller, so that the dye strip 28 contacts the impeller surface and leaves a clear X-shaped positioning mark on the impeller using the dye. After releasing the push rod 27, the elastic restoring force of the spring will reset the animation line plate 26, avoiding unnecessary contamination or blurring of the markings caused by the continuous contact of the dye strip 28 with the impeller surface.

[0058] The terms "front," "back," "left," "right," "top," and "bottom" all refer to the figures in the accompanying drawings. Figure 1 Based 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.

[0059] 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.

[0060] 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 machining steam balance holes on a steam turbine rotor, characterized in that: It includes a drill jig body (1), a bushing (2), a quick-change drill bushing (3), a cylindrical pin (4), and a fastener (5); The drill jig body (1) has a rectangular groove in the thickness direction; the drill jig body (1) has through holes (6) on both sides of the bottom. The bushing (2) is fixedly connected to the inside of the through hole (6) on one side; a quick-change drill sleeve (3) is provided inside the bushing (2). Two cylindrical pins (4) are provided and located at the top of the drill jig body (1); Two fasteners (5) are provided and located on one side of the bottom of the drill jig body (1); the fasteners (5) penetrate through the side wall of the drill jig body (1) and are detachably connected to it; The drill jig body (1) is provided with a set of mating sleeves (7) and mating columns (8) fixedly connected to both sides of each drill jig body (1); a guide block (9) is fixedly connected to the end of the mating column (8). It also includes two mounting ring seats (11), which are disposed on both sides of a set of drill jig bodies (1); the mounting ring seats (11) have an annular groove (12) on their outer periphery; a movable seat (13) is slidably connected inside the annular groove (12); the movable seat (13) is fixedly connected to one of the drill jig bodies (1) by a support arm (14); a reinforcing member (15) is provided on the surface of the movable seat (13), and the reinforcing member (15) passes through the movable seat (13) and is detachably connected to it; A support plate (20) is fixedly connected to the bottom of one of the drill jig bodies (1) near the mounting ring seat (11); an arc-shaped guide rail (21) is fixedly connected to the surface of the support plate (20); a centering plate (22) is slidably connected to the surface of the guide rail (21); a clamping member (23) is provided between the centering plate (22) and the guide rail (21); a drawing assembly is provided on the surface of the centering plate (22); the drawing assembly is used to draw the positioning lines of the balance hole on the impeller surface; The support plate (20) is also fixedly connected to an arc-shaped indicator strip (24); the indicator strip (24) is provided with scale values; and a pointer (25) is fixedly connected to one end of the centering plate (22) near the indicator strip (24).

2. The drilling jig for machining steam balance holes on a steam turbine rotor according to claim 1, characterized in that: The fitting sleeve (7) has a dovetail groove (10) on one side.

3. The drilling jig for machining steam balance holes on a steam turbine rotor according to claim 1, characterized in that: The mounting ring seat (11) is designed as a split structure, and the two halves of the mounting ring seat (11) are detachably connected.

4. The drilling jig for machining steam balance holes on a steam turbine rotor according to claim 1, characterized in that: The top of the drill jig body (1) is slidably connected to a slide plate (16), and a cylindrical pin (4) is located inside the slide plate (16); the top of the slide plate (16) is rotatably connected to an adjusting column (17); the adjusting column (17) passes through the top of the drill jig body (1) and is detachably connected to it.

5. The drilling jig for machining steam balance holes on a steam turbine rotor according to claim 4, characterized in that: The cylindrical pin (4) is fixedly connected to a pin shaft (18); the drill jig body (1) has guide grooves (19) on both sides; the pin shaft (18) passes through the slide plate (16) and the guide groove (19) at both ends, and the pin shaft (18) is rotatably connected to the slide plate (16).

6. The drilling jig for machining steam balance holes on a steam turbine rotor according to claim 1, characterized in that: The line drawing assembly includes a line drawing plate (26); a spring is fixedly connected between the line drawing plate (26) and the centering plate (22); a push rod (27) is fixedly connected to one side of the line drawing plate (26), and the push rod (27) is slidably connected to the centering plate (22); an X-shaped dyeing strip (28) is provided on the other side of the line drawing plate (26); the surface of the dyeing strip (28) is coated with dye.

Images