Method for three-dimensional measurement and indexing of turbine top cover or bottom ring guide vane shaft hole

Abstract

The application provides a three-dimensional measurement indexing processing method for a water turbine top cover or bottom ring guide vane shaft hole, and relates to the field of water turbine manufacturing.The method is based on advanced three-dimensional measurement technology, theoretically calculates and determines the coordinates of the center of each guide vane shaft hole, establishes a theoretical coordinate system, measures the top cover or bottom ring opening surface, base cylindrical surface and guide vane shaft hole in sequence through a laser tracker and a reflecting target ball, establishes a measurement coordinate system with the actual measurement position of the workpiece as a reference, and matches the actual measurement coordinate system with the theoretical coordinate system to analyze and obtain the real position deviation of the center of the currently measured guide vane shaft hole.The coaxiality precision of the top cover and the bottom ring guide vane shaft hole after processing can be greatly improved through the measurement of the guide vane shaft hole, and the original alignment preparation time can be greatly reduced to improve the use efficiency of the machine tool.

Description

Technical Field

[0001] This invention belongs to the field of water turbine manufacturing, and in particular relates to a three-dimensional measurement and indexing machining method for the guide vane shaft hole of the top cover or bottom ring of a water turbine. Background Technology

[0002] In the guide vane mechanism of a hydro turbine, the top cover and bottom ring are the most important and critical components. For the manufacturing and processing of the top cover and bottom ring, minimizing the positional deviation of the guide vane shaft holes to improve the coaxiality of the guide vane shaft holes after assembly is the most critical indicator for controlling and improving product processing quality. Generally speaking, due to the large size of the top cover and bottom ring of a hydro turbine, the most convenient and accurate co-boring method cannot be used for the alignment of their shaft holes. Therefore, external measuring equipment must be used to ensure that the positional deviation of the corresponding guide vane shaft holes meets the design and process requirements. Currently, in traditional manufacturing processes, the positional deviation of the center of the guide vane shaft holes of the top cover and bottom ring is usually obtained by indirect measurement and geometric calculation using linear inside and outside micrometers. This measurement process is time-consuming and labor-intensive, and the final positional accuracy is limited, resulting in low versatility of the top and bottom rings.

[0003] With the development of advanced measurement technology, especially the widespread use of advanced large-size precision three-dimensional measurement technology, more accurate and efficient technical means have been developed for machining the shaft holes of the top cover and bottom ring guide vanes of the turbine guide vane mechanism. Currently, in the industry, three-dimensional measurement technology is only used in engineering applications for the final inspection of turbine parts after machining. No relevant application cases have been found in the indexing and alignment before parts machining. For example, Chinese invention patent CN105729244A, published on July 6, 2016, discloses a process method for measuring the coaxiality of the blind valve shaft holes at both ends of a large turbine valve body. During the machining of the blind valve shaft holes at both ends of the large valve body, a method of measuring the coaxiality between the blind valve shaft holes at both ends of the large valve body by using CNC machine tool programming and laser tracking instrument in combination can solve the technical problem of machining the valve shaft holes at both ends of the large valve body on a heavy-duty CNC rotary table, and improve the product quality of valve body assembly and sealing test. Meanwhile, the laser tracker, combined with the concept of measuring the coaxiality between the two blind valve shaft holes, can be used as a reference for the processing of other large components beyond the processing capabilities of the equipment and for measuring coaxiality.

[0004] To address the shortcomings of existing technologies, this invention proposes a three-dimensional measurement and indexing machining method for the shaft holes of turbine top cover or bottom ring guide vanes. This new method uses three-dimensional measurement technology based on a laser tracker to guide the indexing machining of the shaft holes of turbine top cover and bottom ring guide vanes. This new machining method can significantly improve the coaxiality accuracy of the shaft holes after machining, while also greatly improving the alignment efficiency before shaft hole machining and shortening the preparation time before product machining. Summary of the Invention

[0005] This invention proposes a new indexing machining method for the shaft holes of the top cover and bottom ring guide vanes in the water guide mechanism of a water turbine. Based on advanced three-dimensional measurement technology, this method can greatly improve the coaxiality accuracy of the shaft holes of the top cover and bottom ring guide vanes after machining, while significantly reducing the original alignment preparation time to improve the efficiency of machine tool use.

[0006] The technical solution of the present invention is as follows: A three-dimensional measurement and indexing machining method for the guide vane shaft hole of a turbine top cover or bottom ring includes the following process steps: A three-dimensional measurement and indexing machining method for the guide vane shaft hole of a turbine top cover or bottom ring includes the following process steps: S1. Place the top cover or bottom ring on the machining worktable of the vertical lathe or machine tool, with the flow surface of the workpiece facing upwards. Adjust the jack to make the level of the opening surface of the top cover or the opening surface of the bottom ring less than or equal to the set level. Adjust the locking jaws to keep the top cover or bottom ring fixed. S2. Place a fixed fixture on the flow surface of the top cover or bottom ring to serve as the measurement host station of the laser tracker. Connect and fix the boring tool holder for machining the guide vane shaft hole to the vertical lathe tool post or machine tool post. The reflective target ball tool holder is fastened to the boring tool holder by the connecting screw. The reflective target ball is mounted on the reflective target ball tool holder. Adjust the height of the laser tracker to ensure that the reflective target ball on the boring tool holder is within the measurement field of view of the laser tracker. S3. Calculate and determine the theoretical coordinates of the center of each top cover guide vane shaft hole or bottom ring guide vane shaft hole based on the design drawings of the top cover or bottom ring. S4. Using a laser tracker and a reflective target ball, sequentially measure the top cover opening surface, the top cover base cylindrical surface, and the No. 1 top cover guide vane shaft hole, or the bottom ring opening surface, the bottom ring base cylindrical surface, and the No. 1 bottom ring guide vane shaft hole. Calculate the relevant plane and center coordinates based on the measured data, and establish a measurement coordinate system with the actual measured position of the top cover guide vane shaft hole or the bottom ring guide vane shaft hole as the reference. The actual measurement coordinate system is aligned and matched with the theoretical coordinate system. S5. The allowable positional deviation in the design process is: The analysis yields the current true positional deviation of the center of the guide vane shaft hole of the No. 1 top cover or the guide vane shaft hole of the No. 1 bottom ring. The position of the boring tool bar is adjusted to reduce the positional deviation of the shaft hole center until the design process requirements are met. S6. Referring to the method for calculating and adjusting the position deviation of the center coordinates of the No. 1 top cover guide vane shaft hole or the No. 1 bottom ring guide vane shaft hole, measure and index the remaining top cover guide vane shaft holes or bottom ring guide vane shaft holes in sequence, and calculate and determine the final position deviation of the center coordinate system of all remaining guide vane shaft holes under the premise that the design and process requirements are met.

[0007] Furthermore, in step S1, the levelness is set to 0.05 mm.

[0008] Furthermore, in step S2, the reflective target ball tool holder has magnetic attraction properties and a spherical groove on top for placing the reflective target ball.

[0009] Furthermore, the #1 top cover guide vane shaft hole is one of the number of top cover guide vane shaft holes measured.

[0010] Furthermore, the #1 bottom ring guide vane shaft hole is one of the number of bottom ring guide vane shaft holes measured.

[0011] Furthermore, the step S3, which involves calculating and determining the theoretical coordinates of the center of each top cover guide vane shaft hole, specifically includes: S3A. Assume that the number of guide vane shaft holes in the top cover is N, the diameter of the center distribution circle of the guide vane shaft holes in the top cover is D, take the center of the distribution circle of the guide vane shaft holes in the top cover as the origin O and the line connecting the center of the #1 guide vane shaft hole in the top cover as the +X axis, and take the +X axis counterclockwise 90° as the +Y axis to establish a plane rectangular coordinate system OXY; S3B. Assume the theoretical coordinates of the centers of the guide vane shaft holes from #1 to #N of the top cover are as follows: , ... The theoretical coordinates of the center of each top cover guide vane shaft hole can be calculated using equation (1); Equation (1).

[0012] Furthermore, the specific steps for measuring and obtaining the center coordinates of the guide vane shaft hole of the #1 top cover in step S4 include: S4C. Select M points evenly and sequentially on the top cover opening surface and measure them using a laser tracker and a reflective target ball. The number of measuring points M should be no less than 6 and no greater than the number of guide vane shaft holes N on the top cover. Assume the measured coordinate values ​​of the M measuring points are as follows: , ... Then, the least squares method is used to fit the coordinates of the M measuring points into a plane R; S4D. Select S points uniformly on the cylindrical surface of the top cover base and measure them using a laser tracker reflecting a target ball. The number of measurement points S should be no less than 6 and no greater than the number of guide vane shaft holes N on the top cover. Assume the measured coordinate values ​​of the S measurement points are as follows: , ... First, the coordinates of the S measuring points are projected onto plane R to obtain... , ... Then, these projected coordinate points are fitted into a circle using the least squares method to obtain the measured center coordinates of the base circle. ; S4E. Move the boring bar to above the center of the guide vane shaft hole of the #1 top cover. Adjust its position to ensure that all guide vane shaft holes have sufficient machining allowance. By controlling the vertical lathe or machine tool, slowly rotate the boring bar to select 8 points evenly on its circumference in sequence, stop, and measure the coordinates of each point. , ... After projecting the spatial coordinates of these 8 points onto the R-plane, the least squares method is used to fit a circle to obtain the measured center coordinates of the guide vane shaft hole of the #1 top cover. ; S4F. Based on the measured coordinates of the base circle's center. With the origin, and The line connecting the centers of the circles is the +X-axis, and a planar rectangular coordinate system is established with the +X-axis rotated 90° counterclockwise as the +Y-axis. Therefore, in this coordinate system, the measured center coordinates of the guide vane shaft hole of #1 top cover are: ; S4G. The steps established in S4F above. The coordinate system is a coordinate system that matches the theoretical coordinate system OXY, and the measured center coordinates of the guide vane shaft hole of the No. 1 top cover obtained from it are... Directly with theoretical coordinates Perform calculations and analysis to determine the true positional deviation of the current center position of the shaft hole.

[0013] Furthermore, the specific steps for calculating and analyzing the current true position deviation of the center of the guide vane shaft hole in step S5 include: S5I. Analysis of steps S3B and S4G shows that the actual positional deviation of the current position of the center of the guide vane shaft hole of #1 is... Then there is Equation (2); S5J. If This indicates that the current position of the center of the guide vane shaft hole of the #1 top cover has met the design and process requirements, and no further adjustment is needed. Control the vertical lathe or machine tool to begin boring the guide vane shaft hole of the #1 top cover until the diameter of the hole meets the drawing requirements. After the machining of the guide vane shaft hole of the #1 top cover is completed, the actual positional deviation of its current center position is [value missing]. ; S5K. If This indicates that the current positional deviation of the center of the guide vane shaft hole of the #1 top cover does not meet the requirements and needs to be adjusted. From steps S3B and S4G, it can be seen that the X-axis and Y-axis deviations of the actual center position of the guide vane shaft hole of the #1 top cover relative to the theoretical center position are, respectively, as follows: and Then there is Equation (3); S5L. According to formula (3) and Adjust the size and positive / negative relationship of the boring bar on the vertical lathe or machine tool. When the value is negative, the center of the boring bar should move away from the center of the top cover by a distance of [missing value]. ,when When the value is positive, the center of the boring bar should move towards the center of the top cover, and the distance moved is... ;when When the value is negative, the center of the boring bar should move away from the center of the top cover by a distance of [missing value]. ;when When the value is positive, the center of the boring bar should move towards the center of the top cover, and the moving distance is... ; S5M. After the boring bar stops moving, repeat steps S4E to S5I to calculate the actual positional deviation of the current position of the center of the guide vane shaft hole of #1. ; S5N. If After the machining of the guide vane shaft hole of #1 top cover is completed, the actual positional deviation of its current center position is: ;like Then continue repeating steps S5K to S5M until the requirements are met. Assume that the boring tool holder for the guide vane shaft hole of #1 top cover meets the requirements after n movements. The final center coordinate position deviation of the guide vane shaft hole of #1 top cover is... .

[0014] Furthermore, referring to the method for calculating and adjusting the positional deviation of the center coordinates of the guide vane shaft holes in the No. 1 top cover, repeat steps S4E~S5N to measure and index the remaining guide vane shaft holes in the top cover sequentially. Therefore, the true positional deviation of the center coordinates of all guide vane shaft holes in the top cover is: , i=1,2……N.

[0015] Furthermore, the step S3, which involves calculating and determining the theoretical coordinates of the center of each bottom ring guide vane shaft hole, specifically includes: S3a. Assume that the number of shaft holes of the bottom ring guide vane is N, the diameter of the center distribution circle of the shaft holes of the bottom ring guide vane is D, take the center of the distribution circle of the bottom ring guide vane shaft holes as the origin O and the line connecting the center of the shaft hole of the #1 bottom ring guide vane as the +X axis, and take the +X axis counterclockwise 90° as the +Y axis to establish a plane rectangular coordinate system OXY; S3b. Assume the theoretical coordinates of the centers of the guide vane shaft holes from bottom ring 1# to N# are as follows: , ... The theoretical coordinates of the center of the guide vane shaft hole of each bottom ring can be calculated by equation (4); Equation (4).

[0016] Furthermore, the specific steps for measuring and obtaining the center coordinates of the guide vane shaft hole of the #1 bottom ring in step S4 include: S4c. Select M points evenly and sequentially on the bottom ring opening surface and measure them using a laser tracker and a reflective target ball. The number of measuring points M should be no less than 6 and no greater than the number of guide vane shaft holes N on the bottom ring. Assume the measured coordinate values ​​of the M measuring points are as follows: , ... Then, the least squares method is used to fit the coordinates of the M measuring points into a plane R; S4d. Select S points evenly on the cylindrical surface of the bottom ring base and measure them using a laser tracker and a reflective target ball. The number of measurement points S should be no less than 6 and no greater than the number of guide vane shaft holes N in the bottom ring. Assume the measured coordinate values ​​of the S measurement points are as follows: , ... First, the coordinates of the S measuring points are projected onto plane R to obtain... , ... Then, these projected coordinate points are fitted into a circle using the least squares method to obtain the measured center coordinates of the base circle. ; S4e. Move the boring bar to above the center of the guide vane shaft hole of the #1 bottom ring. Adjust its position to ensure that all guide vane shaft holes have sufficient machining allowance. By controlling the vertical lathe or machine tool, slowly rotate the boring bar to select 8 points evenly on its circumference in sequence, stop, and measure the coordinates of each point. , ... After projecting the spatial coordinates of these 8 points onto the R-plane, the least squares method is used to fit a circle to obtain the measured center coordinates of the shaft hole of the No. 1 bottom ring guide vane. ; S4f. Using the measured coordinates of the base circle's center. With the origin, and The line connecting the centers of the circles is the +X-axis, and a planar rectangular coordinate system is established with the +X-axis rotated 90° counterclockwise as the +Y-axis. Therefore, in this coordinate system, the measured center coordinates of the guide vane shaft hole of the #1 bottom ring are: ; S4g. The steps established in S4f above. The coordinate system is a coordinate system that matches the theoretical coordinate system OXY, and the measured center coordinates of the guide vane shaft hole of the #1 bottom ring obtained from it are... Directly with theoretical coordinates Perform calculations and analysis to determine the true positional deviation of the current center position of the shaft hole.

[0017] Furthermore, the specific steps for calculating and analyzing the current true position deviation of the center of the guide vane shaft hole in step S5 include: S5i. Analysis of steps S3b and S4g shows that the actual positional deviation of the current position of the center of the guide vane shaft hole of the #1 bottom ring is... Then there is Equation (5); S5j. If This indicates that the current position of the center of the #1 bottom ring guide vane shaft hole meets the design and process requirements and no further adjustment is needed. Control the vertical lathe or machine tool to begin boring the #1 bottom ring guide vane shaft hole until the hole diameter meets the drawing requirements. After machining, the actual positional deviation of the current center position of the #1 bottom ring guide vane shaft hole is... ; S5k. If This indicates that the current positional deviation of the center of the guide vane shaft hole of the #1 bottom ring does not meet the requirements and needs to be adjusted. From steps S3b and S4g, it can be seen that the X-axis and Y-axis deviations of the actual center position of the guide vane shaft hole of the #1 bottom ring relative to the theoretical center position are, respectively, as follows: and Then there is Equation (6); S5l. According to formula (6) and Adjust the size and positive / negative relationship of the boring bar on the vertical lathe or machine tool. When the value is negative, the center of the boring bar should move away from the center of the bottom ring by a distance of [missing value]. ,when When the value is positive, the center of the boring bar should move towards the center of the bottom ring, and the distance moved is... ;when When the value is negative, the center of the boring bar should move away from the center of the bottom ring by a distance of [missing value]. ;when When the value is positive, the center of the boring bar should move towards the center of the bottom ring, and the moving distance is... ; S5m. After the boring bar stops moving, repeat steps S4e to S5i to calculate the actual positional deviation of the current position of the center of the #1 bottom ring guide vane shaft hole. ; S5n. If After the machining of the guide vane shaft hole of the #1 bottom ring is completed, the actual positional deviation of its current center position is: ;like Then continue repeating steps S5k to S5m until the requirements are met. Assume that the boring tool holder for the #1 bottom ring guide vane shaft hole meets the requirements after n movements. The final center coordinate position deviation of the guide vane shaft hole of the #1 bottom ring is... .

[0018] Furthermore, referring to the method for calculating and adjusting the positional deviation of the center coordinates of the guide vane shaft holes of the #1 bottom ring, repeat steps S4e~S5n to measure and index the remaining bottom ring guide vane shaft holes in sequence. Therefore, the true positional deviation of the center coordinates of all guide vane shaft holes in the bottom ring is: , i=1,2……N.

[0019] The beneficial effects of this invention are as follows: 1. Compared with the traditional method of using a micrometer as a linear measuring tool to measure and calculate the deviation of the center position of the guide vane shaft hole, the new laser tracker three-dimensional measurement technology is more accurate, convenient and efficient, and can more easily and accurately determine the true spatial coordinates of the measurement target point. 2. The series of process methods and calculation methods proposed in this invention can quickly and accurately adjust the position of the tool holder to meet the design and process requirements for the center position deviation after shaft hole machining; 3. The three-dimensional measurement shaft hole indexing machining method of the present invention can not only avoid calculation system errors and indirect measurement errors, but also greatly reduce measurement errors. This makes the top cover and bottom ring have complete universal interchangeability, which greatly improves the flexibility in manufacturing process and on-site installation. This new processing method can significantly improve the coaxiality accuracy of the top cover and bottom ring guide vane shaft holes after processing, and can also greatly improve the alignment efficiency before shaft hole processing, shortening the preparation time before product processing. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the bottom ring structure of the water guide mechanism of the water turbine; Figure 2This is a schematic diagram of the top cover structure of the water guide mechanism of the water turbine; Figure 3 A schematic diagram of three-dimensional measurement and indexing machining of the guide vane shaft hole for the top cover; Figure 4 This is a schematic diagram of the boring tool holder structure; Figure 5 This is a schematic diagram showing the measurement of the opening surface of the top cover; Figure 6 A schematic diagram showing the measurement of the cylindrical surface of the top cover base and the No. 1 shaft hole; Figure reference numerals: 1-Bottom ring; 2-Bottom ring base cylindrical surface; 3-Bottom ring guide vane shaft hole; 4-Bottom ring opening surface; 5-Top cover; 6-Top cover base cylindrical surface; 7-Top cover guide vane shaft hole; 8-Top cover opening surface; 9-Vertical lathe; 10-Vertical lathe chuck; 11-Jack; 12-Claw; 13-Fixing fixture; 14-Laser tracker; 15-Vertical lathe tool post; 16-Boring tool holder; 17-Boring tool; 18-Reflective target ball; 19-Reflective target ball tool holder; 20-Holding screw. Detailed Implementation

[0021] Example 1 like Figure 1-6 As shown, a three-dimensional measurement and indexing machining method for the guide vane shaft hole of a turbine top cover or bottom ring is characterized by the following process steps for measuring the guide vane shaft hole of the turbine top cover or bottom ring: S1. Place the top cover 5 or bottom ring 1 on the machining worktable of the vertical lathe 9 or machine tool, and place the workpiece with the flow surface facing upward. Adjust the jack 11 to make the level of the top cover opening surface 8 or bottom ring opening surface 4 less than or equal to the set level. Adjust the locking claw 12 to keep the top cover 5 or bottom ring 1 fixed. S2. Place a fixed fixture 13 on the flow surface of the top cover 5 or bottom ring 1 to serve as the measurement host station of the laser tracker 14. Connect and fix the boring bar 16 for machining the guide vane shaft hole to the vertical lathe tool post 15 or the machine tool post. The reflective target ball tool holder 19 is fastened to the boring bar 16 by the connecting screw 20. The reflective target ball 18 is mounted on the reflective target ball tool holder 19. Adjust the height of the laser tracker 14 to ensure that the reflective target ball 18 on the boring bar 16 is within the measurement field of view of the laser tracker 14. S3. Calculate and determine the theoretical coordinates of the center of each top cover guide vane shaft hole 7 or bottom ring guide vane shaft hole 3 based on the design drawings of the top cover or bottom ring. S4. Using the laser tracker 14 and the reflective target ball 18, sequentially measure the top cover opening surface 8, the top cover base cylindrical surface 6, and the No. 1 top cover guide vane shaft hole, or the bottom ring opening surface 4, the bottom ring base cylindrical surface 2, and the No. 1 bottom ring guide vane shaft hole. Calculate the relevant plane and center coordinates based on the measured data, and establish a measurement coordinate system with the actual measured position of the top cover guide vane shaft hole 7 or the bottom ring guide vane shaft hole 3 as the reference. The actual measurement coordinate system is aligned and matched with the theoretical coordinate system. S5. The allowable positional deviation in the design process is: The analysis yields the current true positional deviation of the center of the guide vane shaft hole of the No. 1 top cover or the guide vane shaft hole of the No. 1 bottom ring. The position of the boring bar 16 is adjusted to reduce the positional deviation of the shaft hole center until the design process requirements are met. S6. Referring to the method for calculating and adjusting the position deviation of the center coordinates of the No. 1 top cover guide vane shaft hole or the No. 1 bottom ring guide vane shaft hole, measure and index the remaining top cover guide vane shaft holes 7 or bottom ring guide vane shaft holes 3 in sequence, and calculate and determine the final position deviation of the center coordinate system of all remaining guide vane shaft holes under the premise that the design and process requirements are met.

[0022] In step S1, the levelness is set to 0.05 mm.

[0023] In step S2, the reflective target ball tool holder has magnetic attraction properties and a spherical groove on top for placing the reflective target ball.

[0024] Example 2 Based on the operation steps of Embodiment 1, the No. 1 top cover guide vane shaft hole is one of the number of top cover guide vane shaft holes measured; The specific steps in step S3 for calculating and determining the theoretical coordinates of the center of each top cover guide vane shaft hole include: S3A. Assume that the number of guide vane shaft holes in the top cover is N, the diameter of the center distribution circle of the guide vane shaft holes in the top cover is D, take the center of the distribution circle of the guide vane shaft holes in the top cover as the origin O and the line connecting the center of the #1 guide vane shaft hole in the top cover as the +X axis, and take the +X axis counterclockwise 90° as the +Y axis to establish a plane rectangular coordinate system OXY; S3B. Assume the theoretical coordinates of the centers of the guide vane shaft holes from #1 to #N of the top cover are as follows: , ... The theoretical coordinates of the center of each top cover guide vane shaft hole can be calculated using equation (1); Equation (1).

[0025] Example 3 Based on the operation steps of Embodiment 2, the specific operation steps for measuring and obtaining the center coordinates of the guide vane shaft hole of the #1 top cover in step S4 include: S4C. Select M points evenly and sequentially on the top cover opening surface and measure them using a laser tracker and a reflective target ball. The number of measuring points M should be no less than 6 and no greater than the number of guide vane shaft holes N on the top cover. Assume the measured coordinate values ​​of the M measuring points are as follows: , ... Then, the least squares method is used to fit the coordinates of the M measuring points into a plane R; S4D. Select S points evenly and sequentially on the cylindrical surface of the top cover base and measure them using a laser tracker and a reflective target ball. The number of measurement points S should be no less than 6 and no greater than the number of guide vane shaft holes N on the top cover. Assume the measured coordinate values ​​of the S measurement points are as follows: , ... First, the coordinates of the S measuring points are projected onto plane R to obtain... , ... Then, these projected coordinate points are fitted into a circle using the least squares method to obtain the measured center coordinates of the base circle. ; S4E. Move the boring bar to above the center of the guide vane shaft hole of the #1 top cover. Adjust its position to ensure that all guide vane shaft holes have sufficient machining allowance. By controlling the vertical lathe or machine tool, slowly rotate the boring bar to select 8 points evenly on its circumference in sequence, stop, and measure the coordinates of each point. , ... After projecting the spatial coordinates of these 8 points onto the R-plane, the least squares method is used to fit a circle to obtain the measured center coordinates of the guide vane shaft hole of the #1 top cover. ; S4F. Based on the measured coordinates of the base circle's center. With the origin, and The line connecting the centers of the circles is the +X-axis, and a planar rectangular coordinate system is established with the +X-axis rotated 90° counterclockwise as the +Y-axis. Therefore, in this coordinate system, the measured center coordinates of the guide vane shaft hole of #1 top cover are: ; S4G. The steps established in S4F above. The coordinate system is a coordinate system that matches the theoretical coordinate system OXY, and the measured center coordinates of the guide vane shaft hole of the No. 1 top cover obtained from it are... Directly with theoretical coordinates Perform calculations and analysis to determine the true positional deviation of the current center position of the shaft hole.

[0026] Example 4 Based on the operation steps of Embodiment 3, the specific operation steps for calculating and analyzing the current true position deviation of the center of the guide vane shaft hole of the #1 top cover in step S5 include: S5I. Analysis of steps S3B and S4G shows that the actual positional deviation of the current position of the center of the #1 top cover shaft hole is... Then there is Equation (2); S5J. If This indicates that the current position of the center of the guide vane shaft hole of the #1 top cover has met the design and process requirements, and no further adjustment is needed. Control the vertical lathe or machine tool to begin boring the guide vane shaft hole of the #1 top cover until the diameter of the hole meets the drawing requirements. After the machining of the guide vane shaft hole of the #1 top cover is completed, the actual positional deviation of its current center position is [value missing]. ; S5K. If This indicates that the current positional deviation of the center of the guide vane shaft hole of the #1 top cover does not meet the requirements and needs to be adjusted. From steps S3B and S4G, it can be seen that the X-axis and Y-axis deviations of the actual center position of the guide vane shaft hole of the #1 top cover relative to the theoretical center position are, respectively, as follows: and Then there is Equation (3); S5L. According to formula (3) and Adjust the size and positive / negative relationship of the boring tool holder on the vertical lathe or machine tool. When the value is negative, the center of the boring bar should move away from the center of the top cover by a distance of [missing value]. ,when When the value is positive, the center of the boring bar should move towards the center of the top cover, and the distance moved is... ;when When the value is negative, the center of the boring bar should move away from the center of the top cover by a distance of [missing value]. ;when When the value is positive, the center of the boring bar should move towards the center of the top cover, and the moving distance is... ; S5M. After the boring bar stops moving, repeat steps S4E to S5I to calculate the actual positional deviation of the current position of the center of the guide vane shaft hole of #1. ; S5N. If After the machining of the guide vane shaft hole of #1 top cover is completed, the actual positional deviation of its current center position is: ;like Then continue repeating steps S5K to S5M until the requirements are met. Assume that the boring tool holder for the guide vane shaft hole of #1 top cover meets the requirements after n movements. The final center coordinate position deviation of the guide vane shaft hole of #1 top cover is... .

[0027] Example 5 Based on the operation steps of Example 4, and referring to the method for calculating and adjusting the position deviation of the center coordinates of the guide vane shaft holes of the #1 top cover, steps S4E~S5N are repeated to measure and index the remaining guide vane shaft holes of the top cover in sequence. Therefore, the true position deviation of the center coordinates of all guide vane shaft holes in the top cover ring is: , i=1,2……N.

[0028] Example 6 Based on the operational structure of Embodiment 1, the No. 1 bottom ring guide vane shaft hole is one of the number of measured bottom ring guide vane shaft holes. The specific steps in step S3 to calculate and determine the theoretical coordinates of the center of each bottom ring guide vane shaft hole include: S3a. Assume that the number of shaft holes of the bottom ring guide vane is N, the diameter of the center distribution circle of the shaft holes of the bottom ring guide vane is D, take the center of the distribution circle of the bottom ring guide vane shaft holes as the origin O and the line connecting the center of the shaft hole of the #1 bottom ring guide vane as the +X axis, and take the +X axis counterclockwise 90° as the +Y axis to establish a plane rectangular coordinate system OXY; S3b. Assume the theoretical coordinates of the centers of the guide vane shaft holes from bottom ring 1# to N# are as follows: , ... The theoretical coordinates of the center of the guide vane shaft hole of each bottom ring can be calculated by equation (4); Equation (4).

[0029] Example 7 Based on the operation steps of Embodiment 6, the specific operation steps for measuring and obtaining the center coordinates of the #1 bottom ring guide vane shaft hole in step S4 include: S4c. Select M points evenly and sequentially on the bottom ring opening surface and measure them using a laser tracker and a reflective target ball. The number of measuring points M should be no less than 6 and no greater than the number of guide vane shaft holes N on the bottom ring. Assume the measured coordinate values ​​of the M measuring points are as follows: , ... Then, the least squares method is used to fit the coordinates of the M measuring points into a plane R; S4d. Select S points evenly on the cylindrical surface of the bottom ring base and measure them using a laser tracker and a reflective target ball. The number of measurement points S should be no less than 6 and no greater than the number of guide vane shaft holes N in the bottom ring. Assume the measured coordinate values ​​of the S measurement points are as follows: , ... First, the coordinates of the S measuring points are projected onto plane R to obtain... , ... Then, these projected coordinate points are fitted into a circle using the least squares method to obtain the measured center coordinates of the base circle. ; S4e. Move the boring bar to above the center of the guide vane shaft hole of the #1 bottom ring. Adjust its position to ensure that all guide vane shaft holes have sufficient machining allowance. By controlling the vertical lathe or machine tool, slowly rotate the boring bar to select 8 points evenly on its circumference in sequence, stop, and measure the coordinates of each point. , ... After projecting the spatial coordinates of these 8 points onto the R-plane, the least squares method is used to fit a circle to obtain the measured center coordinates of the shaft hole of the No. 1 bottom ring guide vane. ; S4f. Using the measured coordinates of the base circle's center. With the origin, and The line connecting the centers of the circles is the +X-axis, and a planar rectangular coordinate system is established with the +X-axis rotated 90° counterclockwise as the +Y-axis. Therefore, in this coordinate system, the measured center coordinates of the guide vane shaft hole of the #1 bottom ring are: ; S4g. The steps established in S4f above. The coordinate system is a coordinate system that matches the theoretical coordinate system OXY, and the measured center coordinates of the guide vane shaft hole of the #1 bottom ring obtained from it are... Directly with theoretical coordinates Perform calculations and analysis to determine the true positional deviation of the current center position of the shaft hole.

[0030] Example 8 Based on the operation steps of Embodiment 7, the specific operation steps for calculating and analyzing the current true position deviation of the center of the #1 bottom ring guide vane shaft hole in step S5 include: S5i. Analysis of steps S3b and S4g shows that the actual positional deviation of the current position of the center of the guide vane shaft hole of the #1 bottom ring is... Then there is Equation (5); S5j. If This indicates that the current position of the center of the #1 bottom ring guide vane shaft hole meets the design and process requirements and no further adjustment is needed. Control the vertical lathe or machine tool to begin boring the #1 bottom ring guide vane shaft hole until the hole diameter meets the drawing requirements. After machining, the actual positional deviation of the current center position of the #1 bottom ring guide vane shaft hole is... ; S5k. If This indicates that the current positional deviation of the center of the guide vane shaft hole of the #1 bottom ring does not meet the requirements and needs to be adjusted. From steps S3b and S4g, it can be seen that the X-axis and Y-axis deviations of the actual center position of the guide vane shaft hole of the #1 bottom ring relative to the theoretical center position are, respectively, as follows: and Then there is Equation (6); S5l. According to formula (6) and Adjust the size and positive / negative relationship of the boring bar on the vertical lathe or machine tool. When the value is negative, the center of the boring bar should move away from the center of the bottom ring by a distance of [missing value]. ,when When the value is positive, the center of the boring bar should move towards the center of the bottom ring, and the distance moved is... ;when When the value is negative, the center of the boring bar should move away from the center of the bottom ring by a distance of [missing value]. ;when When the value is positive, the center of the boring bar should move towards the center of the bottom ring, and the moving distance is... ; S5m. After the boring tool holder stops moving, repeat steps S4e to S5i to calculate the actual positional deviation of the current position of the center of the #1 bottom ring guide vane shaft hole. ; S5n. If After the machining of the guide vane shaft hole of the #1 bottom ring is completed, the actual positional deviation of its current center position is: ;like Then continue repeating steps S5k to S5m until the requirements are met. Assume that the boring tool holder for the #1 bottom ring guide vane shaft hole meets the requirements after n movements. The final center coordinate position deviation of the guide vane shaft hole of the #1 bottom ring is... .

[0031] Example 9 Based on the operation steps of Example 8, and referring to the method for calculating and adjusting the position deviation of the center coordinates of the guide vane shaft holes of the #1 bottom ring, steps S4e~S5n are repeated to measure and index the remaining bottom ring guide vane shaft holes in sequence. Therefore, the true position deviation of the center coordinates of all guide vane shaft holes of the bottom ring is: , i=1,2……N.

Claims

1. A method for three-dimensional measurement and indexing machining of guide vane shaft holes in a turbine top cover or bottom ring, characterized in that: Measuring the shaft holes of the turbine top cover or bottom ring guide vanes includes the following steps: S1. Place the top cover (5) or bottom ring (1) on the machining worktable of the vertical lathe (9) or machine tool, and place the workpiece with the flow surface facing upward. Adjust the jack (11) so that the level of the top cover opening surface (8) or bottom ring opening surface (4) is less than or equal to the set level. Adjust the locking claw (12) so that the top cover (5) or bottom ring (1) remains fixed. S2. Place a fixed fixture (13) on the flow surface of the top cover (5) or bottom ring (1) to serve as the measurement host station of the laser tracker (14). Connect and fix the boring bar (16) for machining the guide vane shaft hole to the vertical lathe tool post (15) or the machine tool post. The reflective target ball tool seat (19) is fastened to the boring bar (16) by the connecting screw (20). The reflective target ball (18) is mounted on the reflective target ball tool seat (19). Adjust the height of the laser tracker (14) to ensure that the reflective target ball (18) on the boring bar (16) is within the measurement field of the laser tracker (14). S3. Based on the design drawings of the top cover or bottom ring, calculate and determine the theoretical coordinates of the center of each top cover guide vane shaft hole (7) or bottom ring guide vane shaft hole (3); S4. Using a laser tracker (14) and a reflective target ball (18), the top cover opening surface (8), the top cover base cylindrical surface (6), the No. 1 top cover guide vane shaft hole or the bottom ring opening surface (4), the bottom ring base cylindrical surface (2), and the No. 1 bottom ring guide vane shaft hole are measured sequentially. The relevant plane and center coordinates are calculated based on the measured data, and a measurement coordinate system is established with the actual measurement position of the top cover guide vane shaft hole (7) or the bottom ring guide vane shaft hole (3) as the reference. The actual measurement coordinate system is aligned and matched with the theoretical coordinate system. S5. The allowable positional deviation in the design process is: The analysis yields the current true positional deviation of the center of the guide vane shaft hole of the No. 1 top cover or the guide vane shaft hole of the No. 1 bottom ring. The position of the boring bar (16) is adjusted to reduce the positional deviation of the shaft hole center until the design process requirements are met. S6. Referring to the method of calculating and adjusting the position deviation of the center coordinates of the No. 1 top cover guide vane shaft hole or the No. 1 bottom ring guide vane shaft hole, measure and index the remaining top cover guide vane shaft holes (7) or bottom ring guide vane shaft holes (3) in sequence, and calculate and determine the final position deviation of the center coordinate system of all remaining guide vane shaft holes under the premise that the design and process requirements are met.

2. The method for three-dimensional measurement and indexing machining of the guide vane shaft hole of a turbine top cover or bottom ring according to claim 1, characterized in that: In step S1, the levelness is set to 0.05 mm.

3. The method for three-dimensional measurement and indexing machining of the guide vane shaft hole of a turbine top cover or bottom ring according to claim 1, characterized in that: In step S2, the reflective target ball tool holder (19) has magnetic attraction properties and a spherical groove on top for placing the reflective target ball (18).

4. The method for three-dimensional measurement and indexing machining of the guide vane shaft hole of a turbine top cover or bottom ring according to claim 1, characterized in that: The #1 top cover guide vane shaft hole is one of the number of top cover guide vane shaft holes (7) measured.

5. The method for three-dimensional measurement and indexing machining of the guide vane shaft hole of a turbine top cover or bottom ring according to claim 1, characterized in that: The #1 bottom ring guide vane shaft hole is one of the number of bottom ring guide vane shaft holes (3) measured.

6. The method for three-dimensional measurement and indexing machining of the guide vane shaft hole of a turbine top cover or bottom ring according to claim 4, characterized in that: The specific steps in step S3 for calculating and determining the theoretical coordinates of the center of each top cover guide vane shaft hole include: S3A. Assume that the number of guide vane shaft holes in the top cover is N, the diameter of the center distribution circle of the guide vane shaft holes in the top cover is D, take the center of the distribution circle of the guide vane shaft holes in the top cover as the origin O and the line connecting the center of the #1 guide vane shaft hole in the top cover as the +X axis, and take the +X axis counterclockwise 90° as the +Y axis to establish a plane rectangular coordinate system OXY; S3B. Assume the theoretical coordinates of the centers of the guide vane shaft holes from #1 to #N of the top cover are as follows: , ... The theoretical coordinates of the center of each top cover guide vane shaft hole can be calculated using equation (1); Equation (1).

7. The method for three-dimensional measurement and indexing machining of the guide vane shaft hole of a turbine top cover or bottom ring according to claim 6, characterized in that: The specific steps for measuring and obtaining the center coordinates of the guide vane shaft hole of the #1 top cover in step S4 include: S4C. Select M points evenly and sequentially on the top cover opening surface and measure them using a laser tracker and a reflective target ball. The number of measuring points M should be no less than 6 and no greater than the number of guide vane shaft holes N on the top cover. Assume the measured coordinate values ​​of the M measuring points are as follows: , ... Then, the least squares method is used to fit the coordinates of the M measuring points into a plane R; S4D. Select S points uniformly on the cylindrical surface of the top cover base and measure them using a laser tracker reflecting a target ball. The number of measurement points S should be no less than 6 and no greater than the number of guide vane shaft holes N on the top cover. Assume the measured coordinate values ​​of the S measurement points are as follows: , ... First, the coordinates of the S measuring points are projected onto plane R to obtain... , ... Then, these projected coordinate points are fitted into a circle using the least squares method to obtain the measured center coordinates of the base circle. ; S4E. Move the boring bar to above the center of the guide vane shaft hole of the #1 top cover. Adjust its position to ensure that all guide vane shaft holes have sufficient machining allowance. By controlling the vertical lathe or machine tool, slowly rotate the boring bar to select 8 points evenly on its circumference in sequence, stop, and measure the coordinates of each point. , ... After projecting the spatial coordinates of these 8 points onto the R-plane, the least squares method is used to fit a circle to obtain the measured center coordinates of the guide vane shaft hole of the #1 top cover. ; S4F. Based on the measured coordinates of the base circle's center. With the origin, and The line connecting the centers of the circles is the +X-axis, and a planar rectangular coordinate system is established with the +X-axis rotated 90° counterclockwise as the +Y-axis. Therefore, in this coordinate system, the measured center coordinates of the guide vane shaft hole of #1 top cover are: ; S4G. The steps established in S4F above. The coordinate system is a coordinate system that matches the theoretical coordinate system OXY, and the measured center coordinates of the guide vane shaft hole of the No. 1 top cover obtained from it are... Directly with theoretical coordinates Perform calculations and analysis to determine the true positional deviation of the current center position of the shaft hole.

8. A three-dimensional measurement and indexing machining method for the guide vane shaft hole of a turbine top cover or bottom ring according to claim 7, characterized in that: The specific steps for calculating and analyzing the current true positional deviation of the center of the guide vane shaft hole of the #1 top cover in step S5 include: S5I. Analysis of steps S3B and S4G shows that the actual positional deviation of the current position of the center of the guide vane shaft hole of #1 is... Then there is Equation (2); S5J. If This indicates that the current position of the center of the guide vane shaft hole of the #1 top cover has met the design and process requirements, and no further adjustment is needed. Control the vertical lathe or machine tool to begin boring the guide vane shaft hole of the #1 top cover until the diameter of the hole meets the drawing requirements. After the machining of the guide vane shaft hole of the #1 top cover is completed, the actual positional deviation of its current center position is [value missing]. ; S5K. If This indicates that the current positional deviation of the center of the guide vane shaft hole of the #1 top cover does not meet the requirements and needs to be adjusted. From steps S3B and S4G, it can be seen that the X-axis and Y-axis deviations of the actual center position of the guide vane shaft hole of the #1 top cover relative to the theoretical center position are, respectively, as follows: and Then there is Equation (3); S5L. According to formula (3) and Adjust the size and positive / negative relationship of the boring bar on the vertical lathe or machine tool. When the value is negative, the center of the boring bar should move away from the center of the top cover by a distance of [missing value]. ,when When the value is positive, the center of the boring bar should move towards the center of the top cover, and the distance moved is... ;when When the value is negative, the center of the boring bar should move away from the center of the top cover by a distance of [missing value]. ;when When the value is positive, the center of the boring bar should move towards the center of the top cover, and the moving distance is... ; S5M. After the boring bar stops moving, repeat steps S4E to S5I to calculate the actual positional deviation of the current position of the center of the guide vane shaft hole of #1. ; S5N. If After the machining of the guide vane shaft hole of #1 top cover is completed, the actual positional deviation of its current center position is: ;like Then continue repeating steps S5K to S5M until the requirements are met. Assume that the boring tool holder for the guide vane shaft hole of #1 top cover meets the requirements after n movements. The final center coordinate position deviation of the guide vane shaft hole of the #1 top cover is... .

9. A three-dimensional measurement and indexing machining method for the guide vane shaft hole of a turbine top cover or bottom ring according to claim 8, characterized in that: Referring to the method for calculating and adjusting the positional deviation of the center coordinates of the guide vane shaft holes in the No. 1 top cover, repeat steps S4E~S5N to measure and index the remaining guide vane shaft holes in the top cover sequentially. Therefore, the true positional deviation of the center coordinates of all guide vane shaft holes in the top cover is: , i=1,2……N.

10. A three-dimensional measurement and indexing machining method for the guide vane shaft hole of a turbine top cover or bottom ring according to claim 5, characterized in that: The specific steps in step S3 for calculating and determining the theoretical coordinates of the center of each bottom ring guide vane shaft hole include: S3a. Assume that the number of shaft holes of the bottom ring guide vane is N, the diameter of the center distribution circle of the shaft holes of the bottom ring guide vane is D, take the center of the distribution circle of the bottom ring guide vane shaft holes as the origin O and the line connecting the center of the shaft hole of the #1 bottom ring guide vane as the +X axis, and take the +X axis counterclockwise 90° as the +Y axis to establish a plane rectangular coordinate system OXY; S3b. Assume the theoretical coordinates of the centers of the guide vane shaft holes from bottom ring 1# to N# are as follows: , ... The theoretical coordinates of the center of the guide vane shaft hole of each bottom ring can be calculated by equation (4); Equation (4).

11. A three-dimensional measurement and indexing machining method for the guide vane shaft hole of a turbine top cover or bottom ring according to claim 10, characterized in that: The specific steps for measuring and obtaining the center coordinates of the #1 bottom ring guide vane shaft hole in step S4 include: S4c. Select M points evenly and sequentially on the bottom ring opening surface and measure them using a laser tracker and a reflective target ball. The number of measuring points M should be no less than 6 and no greater than the number of guide vane shaft holes N on the bottom ring. Assume the measured coordinate values ​​of the M measuring points are as follows: , ... Then, the least squares method is used to fit the coordinates of the M measuring points into a plane R; S4d. Select S points evenly on the cylindrical surface of the bottom ring base and measure them using a laser tracker and a reflective target ball. The number of measurement points S should be no less than 6 and no greater than the number of guide vane shaft holes N in the bottom ring. Assume the measured coordinate values ​​of the S measurement points are as follows: , ... First, the coordinates of the S measuring points are projected onto plane R to obtain... , ... Then, these projected coordinate points are fitted into a circle using the least squares method to obtain the measured center coordinates of the base circle. ; S4e. Move the boring bar to above the center of the guide vane shaft hole of the #1 bottom ring. Adjust its position to ensure that all guide vane shaft holes have sufficient machining allowance. By controlling the vertical lathe or machine tool, slowly rotate the boring bar to select 8 points evenly on its circumference in sequence, stop, and measure the coordinates of each point. , ... After projecting the spatial coordinates of these 8 points onto the R-plane, the least squares method is used to fit a circle to obtain the measured center coordinates of the shaft hole of the No. 1 bottom ring guide vane. ; S4f. Using the measured coordinates of the base circle's center. With the origin, and The line connecting the centers of the circles is the +X-axis, and a planar rectangular coordinate system is established with the +X-axis rotated 90° counterclockwise as the +Y-axis. Therefore, in this coordinate system, the measured center coordinates of the guide vane shaft hole of the #1 bottom ring are: ; S4g. The steps established in S4f above. The coordinate system is a coordinate system that matches the theoretical coordinate system OXY, and the measured center coordinates of the guide vane shaft hole of the #1 bottom ring obtained from it are... Directly with theoretical coordinates Perform calculations and analysis to determine the true positional deviation of the current center position of the shaft hole.

12. A three-dimensional measurement and indexing machining method for the guide vane shaft hole of a turbine top cover or bottom ring according to claim 11, characterized in that: The specific steps for calculating and analyzing the current true position deviation of the center of the #1 bottom ring guide vane shaft hole in step S5 include: S5i. Analysis of steps S3b and S4g shows that the actual positional deviation of the current position of the center of the guide vane shaft hole of the #1 bottom ring is... Then there is Equation (5); S5j. If This indicates that the current position of the center of the #1 bottom ring guide vane shaft hole meets the design and process requirements and no further adjustment is needed. Control the vertical lathe or machine tool to begin boring the #1 bottom ring guide vane shaft hole until the hole diameter meets the drawing requirements. After machining, the actual positional deviation of the current center position of the #1 bottom ring guide vane shaft hole is... ; S5k. If This indicates that the current positional deviation of the center of the guide vane shaft hole of the #1 bottom ring does not meet the requirements and needs to be adjusted. From steps S3b and S4g, it can be seen that the X-axis and Y-axis deviations of the actual center position of the guide vane shaft hole of the #1 bottom ring relative to the theoretical center position are, respectively, as follows: and Then there is Equation (6); S5l. According to formula (6) and Adjust the size and positive / negative relationship of the boring bar on the vertical lathe or machine tool. When the value is negative, the center of the boring bar should move away from the center of the bottom ring by a distance of [missing value]. ,when When the value is positive, the center of the boring bar should move towards the center of the bottom ring, and the distance moved is... ;when When the value is negative, the center of the boring bar should move away from the center of the bottom ring by a distance of [missing value]. ;when When the value is positive, the center of the boring bar should move towards the center of the bottom ring, and the moving distance is... ; S5m. After the boring bar stops moving, repeat steps S4e to S5i to calculate the actual positional deviation of the current position of the center of the #1 bottom ring guide vane shaft hole. ; S5n. If After the machining of the guide vane shaft hole of the #1 bottom ring is completed, the actual positional deviation of its current center position is: ;like Then continue repeating steps S5k to S5m until the requirements are met. Assume that the boring tool holder for the #1 bottom ring guide vane shaft hole meets the requirements after n movements. The final center coordinate position deviation of the guide vane shaft hole of the #1 bottom ring is... .

13. A three-dimensional measurement and indexing machining method for the guide vane shaft hole of a turbine top cover or bottom ring according to claim 12, characterized in that: Referring to the method for calculating and adjusting the positional deviation of the center coordinates of the guide vane shaft holes in the #1 bottom ring, repeat steps S4e~S5n to measure and index the remaining guide vane shaft holes in the bottom ring sequentially. Therefore, the true positional deviation of the center coordinates of all guide vane shaft holes in the bottom ring is: , i=1,2……N.

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