Flange hole processing method and processing tooling

Abstract

The present application belongs to the technical field of large component flange hole processing, and discloses a flange hole processing method and processing tool, which comprises the following steps: positioning on the bed frame after the cable reel (1) is manufactured; inner circle (2) machining, determining the inner circle (2) reference; determining the center reference by using a laser tracker (4); setting the reference target (5) as a target point, and transferring the center reference to the target point; determining the center position of part of the upper and lower flange holes according to the center reference measurement positioning target (6) coordinates, and center positioning target; determining the remaining flange hole center position; repeating the sixth step until the flange hole center position is positioned; installing the processing tool (7) at the flange hole center position, adjusting the perpendicularity of the drill rod (8), and aligning the center of the flange hole; fixing the boring machine (10), and processing the flange hole. The present application ensures the positioning accuracy of double-layer flange holes, and the processing accuracy is far superior to that of traditional processes, and meets the high-end large cable reel assembly accuracy requirements.

Description

Technical Field

[0001] This invention belongs to the field of flange hole processing technology for large components, specifically a flange hole processing method and tooling. Background Technology

[0002] Large-diameter double-flange cable reels are major load-bearing components of marine vessels. The flange hole distribution circle diameter of the double-flange is 29600mm, and the center distance is 155±0.1mm. Machining flange holes on this large-diameter double-flange is a challenge. In existing technologies, the machining of flange holes on large-diameter cable reels mostly adopts a single-setup, single-point positioning, and single-station measurement machining mode. For double-flange hole machining, the accuracy of the double holes is generally difficult to guarantee. Traditional processes mostly involve machining one hole at a time with a single machine, which cannot be done in parallel. Due to the large number of large-diameter flange holes, the machining cycle is long.

[0003] The relevant reference CN106383496A discloses a method for machining flange holes on large-diameter spherical shells. This method uses laser tracking technology to measure the spatial coordinates of the entire spherical shell and the coordinates of the position of the flange hole relative to the normal of the spherical center. The target point is used for positioning. Then, a small CNC machining center is fixed to the position of the flange hole to be machined on the spherical shell using auxiliary clamping, so that the cutting rotation center axis of the tool coincides with the normal of the flange hole relative to the center of the spherical shell. Finally, the flange hole is cut out. This method improves the positional accuracy of flange hole positioning and machining. However, the accuracy of positioning double-layer holes is difficult to guarantee. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a machining method and tooling for machining flange holes that ensures the positioning accuracy of double-layer flange holes and improves machining efficiency.

[0005] To solve the above technical problems, the present invention provides a method for processing flange holes, comprising the following steps: Step 1: After the cable reel is manufactured, position it on the upper frame; one end of the cable reel is successively integrated with the upper flange and the lower flange; Step 2: Inner circle machining to determine the inner circle datum; the track surface at the bottom of the cable reel is the horizontal datum. Step 3: Use a laser tracker to measure the inner circle and determine the center reference of the cable reel; Step 4: Set up several reference targets (5) around the cable reel as target points, and transfer the central reference to the target points; Step 5: Using the center of the cable reel as a reference, the laser tracker measures the coordinates of the positioning target; based on the relative coordinates, hole distribution circle, hole diameter center distance, and angular deviation, determine the center position of some flange holes, mark the center positions of the upper flange holes and the lower flange holes together, and place the positioning target at the center position of the upper flange holes and the lower flange holes respectively. Step 6: Move the laser tracker to determine the center of the cable reel using the surrounding target points as a reference, and use this to determine the center positions of the flange holes on the remaining parts of the upper and lower flanges. Step 7: Repeat step 6 until the center positions of all flange holes are located. Step 8: Install the machining fixture at the center of the flange hole, adjust the verticality of the drill rod and align it with the center of the flange hole; according to manpower and project progress, configure the corresponding number of machining fixtures on the upper flange and process the flange hole simultaneously. One boring machine can complete about 20 flange holes per day. Step 9: Fix the boring machine. After machining the upper flange hole, replace it with an extended drill rod. Check the center position of the lower flange hole and then complete the machining of the lower flange hole.

[0006] The method eliminates datum offset and cumulative error throughout the process by machining the inner circle, fitting the entire range of the laser tracker, and transferring the center datum. Combined with tooling adjustment and secondary verification and positioning by replacing the drill rod with an extended one, it ensures the positioning accuracy of the double-layer flange hole. The machining accuracy is far superior to that of traditional processes and meets the assembly accuracy requirements of high-end large cable reel.

[0007] Preferably, in step three, the laser tracker uniformly collects the three-dimensional spatial coordinates of multiple measuring points on the inner wall of the inner circle of the cable reel; a standard circle is fitted from the measuring points on the same plane, and the computer calculates the geometric center coordinates and inner radius of the inner circle on the plane based on the measured data; the center of the fitted standard circle is the center reference of the cable reel.

[0008] Preferably, in step three, the laser tracker uniformly collects the three-dimensional spatial coordinates of multiple measuring points on the inner wall of the inner circle of the cable reel; a standard circle is fitted to the measuring points on the same plane, and the computer calculates the geometric center coordinates and inner radius of the inner circle on the plane based on the measured data; the center of the fitted standard circle is the center reference of the cable reel; the three-dimensional coordinates of all the peripheral reference targets are measured one by one using the same set of measurement coordinate system.

[0009] Preferably, in step four, the reference targets are arranged symmetrically around the circumference, with equal diameters and radial orientation, and then affixed to the ground. All the reference targets together form an external virtual circle, the center of which is equal to the actual center of the cable reel.

[0010] Preferably, in step four, the laser tracker measures the coordinates of the reference targets, and a fixed spatial relative relationship of distance, azimuth, and elevation difference is formed between the center of the cable reel and each reference target; the center reference is transferred to the target point through coordinate conversion between the center coordinates and the coordinates of each reference target; after the laser tracker obtains the measured spatial coordinates of the positioning target, it calculates the center coordinates of the upper flange hole and the lower flange hole by combining the coordinate conversion between the reference target and the positioning target, in accordance with the drawing requirements.

[0011] Preferably, in step five, several cement blocks are set around the reference target, and the laser tracker is placed on several of the cement blocks.

[0012] Preferably, in step six, the laser tracker is moved to the remaining portion of the concrete block.

[0013] A machining fixture for processing flange holes includes a positioning target and a boring machine. The boring machine is equipped with a drill rod. The boring machine is mounted on one end face of an assembly plate, and a right-angled positioning plate is integrally formed on the other end face of the assembly plate. Fastening holes are formed on the positioning plate, and fasteners are installed in the fastening holes. There is a gap between the assembly plate and the positioning plate to accommodate an upper flange. Positioning targets are arranged on both the upper and lower flanges. The boring machine is mounted on the assembly plate, and the integrally formed right-angled positioning plate enables rapid clamping and locking of the flange. A laser tracker is used to accurately calibrate the position with the positioning targets, ensuring a unified reference and sufficient rigidity. This method effectively guarantees the precision machining requirements of the flange holes while simplifying the clamping and positioning processes and improving machining efficiency.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention eliminates reference offset and cumulative error throughout the process by internal circular machining, laser tracking full-range fitting, and center reference transfer. Combined with tooling adjustment and replacement of extended drill rods for secondary verification and positioning, it ensures the positioning accuracy of the double-layer flange holes. The hole position accuracy reaches Φ0.5mm, and the machining accuracy is far superior to traditional processes, meeting the precision requirements of high-end large cable reel assembly.

[0015] 2. This invention enables synchronous positioning of double-layer holes and parallel operation of multiple tooling, abandoning the single-hole sequential processing mode. One boring machine can process up to 20 flange holes per day, significantly improving overall processing efficiency and quickly adapting to various project schedule requirements.

[0016] 3. The machining fixture of this invention mounts the boring machine onto the assembly plate, and uses an integrated right-angle positioning plate to achieve rapid clamping and locking of the flange; the laser tracker and positioning target are used to accurately calibrate the position, ensuring a unified reference and sufficient rigidity. The fixture effectively guarantees the precision machining requirements of the flange hole, simplifies the clamping and positioning process, and improves machining efficiency. Attached Figure Description

[0017] Figure 1 This is a schematic diagram showing the arrangement of the cable reel, reference target, and laser tracker in this invention; Figure 2 This is a schematic diagram of the positioning target arrangement of the present invention; Figure 3 For the present invention Figure 2 A schematic diagram of the BB direction; Figure 4 For the present invention Figure 3 Enlarged view of point A in the middle.

[0018] Drawing numbers: 1. Cable reel, 2. Inner circle, 3. Track surface, 4. Laser tracker, 5. Reference target, 6. Positioning target, 7. Machining fixture, 8. Drill rod, 9. Upper flange, 10. Boring machine, 11. Assembly plate, 12. Positioning plate, 13. Fastening hole, 14. Fastener, 15. Lower flange, 16. Cement block. Detailed Implementation

[0019] like Figure 1-3 As shown, a method for machining a flange hole includes the following steps: Step 1: After the cable reel 1 is manufactured, the upper frame is positioned; the bottom of the cable reel 1 is sequentially integrated with the upper flange 9 and the lower flange 15.

[0020] Step 2: Machining the inner circle 2 of cable reel 1 to determine the datum of the inner circle 2; the track surface 3 at the bottom of cable reel 1 is the horizontal datum. Step 3: Use laser tracker 4 to measure the inner circle 2 to determine the center reference of cable reel 1; Step four: Set up several reference targets 5 around the cable reel 1 as target points, such as... Figure 1 All target coordinates are uniformly calibrated with the central reference as the center, and the central reference is transferred to the target. Step 5: Using the center of cable reel 1 as a reference, the laser tracker 4 measures the coordinates of the positioning target 6; based on the relative coordinates, hole distribution circle, hole diameter center distance, and angular deviation, determine the center positions of some flange holes. Mark the center positions of the upper and lower flange holes together on the upper flange 9 and lower flange 15, respectively. Place the positioning target 6 at the center positions of the upper and lower flange holes, respectively. Figure 2 .

[0021] Step 6: Move the laser tracker 4 and use the surrounding target points as a reference to determine the center of the cable reel 1, and use this to determine the center position of the flange holes of the remaining parts on the upper flange 9 and lower flange 15. Step 7: Repeat step 6 until the center positions of all flange holes are located. Step 8: Install machining fixture 7 at the center of the flange hole, such as... Figure 3 Drill upper flange holes on upper flange 9 and lower flange holes on lower flange 15. Adjust the verticality of drill rod 8 and align it with the center of the flange holes. Based on manpower and project progress, configure a corresponding number of machining fixtures 7 on upper flange 9 to simultaneously process the flange holes. One boring machine 10 can complete about 20 flange holes per day. Step 9: Fix the boring machine 10, and after machining the upper flange hole, replace the extended drill rod 8, check the center position of the lower flange hole, and then complete the machining of the lower flange hole.

[0022] This invention eliminates reference offset and cumulative error throughout the process by machining the inner circle 2, fitting the entire range of the laser tracker 4, and transferring the center reference. Combined with tooling adjustment and secondary verification and positioning by replacing the extended drill rod 8, it ensures the positioning accuracy of the double-layer flange hole. The machining accuracy is far superior to that of traditional processes, meeting the assembly accuracy requirements of high-end large cable reel 1.

[0023] In step three, the laser tracker 4 uniformly collects the three-dimensional spatial coordinates of multiple measuring points on the inner wall of the inner circle 2 of the cable reel 1; a standard circle is fitted to the measuring points on the same plane, and the computer calculates the geometric center coordinates and radius of the inner circle 2 on the plane based on the measured data; the center of the fitted standard circle is the center reference of the cable reel 1; the three-dimensional coordinates of all the outer reference targets 5 are measured one by one using the same set of measurement coordinate system.

[0024] In step four, the reference targets 5 are arranged symmetrically around the circumference, with equal diameter and radial orientation, and affixed to the ground. All reference targets 5 together form an external virtual circle, the center of which is equal to the actual center of the cable reel 1. The laser tracker 4 measures the coordinates of the reference targets 5, establishing a fixed spatial relationship of distance, azimuth, and elevation difference between the center of the cable reel 1 and each reference target 5. The center reference is transferred to the target point through coordinate conversion between the center coordinates and the coordinates of each reference target 5. After obtaining the measured spatial coordinates of the positioning target 6, the laser tracker 4 calculates the center coordinates of the upper flange hole and the lower flange hole by combining the coordinate conversion between the reference targets 5 and the positioning target 6, in accordance with the drawing requirements.

[0025] A method for machining flange holes using machining fixtures, such as... Figure 4 As shown, the machining fixture 7 includes a positioning target 6 and a boring machine 10. The boring machine 10 is equipped with a drill rod 8. The boring machine 10 is installed on one end face of the assembly plate 11. The other end face of the assembly plate 11 is integrally formed with a right-angled positioning plate 12. The positioning plate 12 has a fastening hole 13, and a fastener 14 is installed in the fastening hole 13. There is a gap between the assembly plate 11 and the positioning plate 12 to accommodate the upper flange 9. Positioning targets 6 are arranged on both the upper flange 9 and the lower flange 15.

[0026] The boring machine 10 is mounted on the assembly plate 11, and together with the integrated right-angle positioning plate 12, the flange can be quickly clamped and locked. The laser tracker 4 and the positioning target 6 are used to accurately calibrate the position, ensuring a unified reference and sufficient rigidity. This effectively guarantees the precision machining requirements of the flange hole, simplifies the clamping and positioning process, and improves machining efficiency.

[0027] In step five, several cement blocks 16 are evenly arranged around the periphery of the reference target 5 to match the height for flange hole measurement and positioning. The laser tracker 4 is placed on several of these cement blocks 16. In step six, the laser tracker 4 is moved to the remaining cement blocks 16. The reference targets 5 are arranged symmetrically around the circumference, with equal diameters and radial orientation, and are affixed to the ground. All the reference targets 5 together form an circumscribed virtual circle, the center of which is equal to the actual center of the cable reel 1.

[0028] This invention eliminates reference offset and cumulative error throughout the process by machining the inner circle 2, fitting the entire range of the laser tracker 4, and transferring the center reference. Combined with tooling adjustment and replacement of the extended drill rod 8 for secondary verification and positioning, it ensures the positioning accuracy of the double-layer flange hole. The hole position accuracy reaches Φ0.5mm, and the machining accuracy is far superior to that of traditional processes, meeting the assembly accuracy requirements of high-end large cable reel 1.

[0029] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for machining flange holes, characterized in that: Includes the following steps: Step 1: After the cable reel (1) is made, the upper frame is positioned; one end of the cable reel (1) is successively integrated with the upper flange (9) and the lower flange (15). Step 2: Machining the inner circle (2) to determine the datum of the inner circle (2); the track surface (3) at the bottom of the cable reel (1) is the horizontal datum; Step 3: Use a laser tracker (4) to measure the inner circle (2) and determine the center reference of the cable reel (1); Step 4: Set up several reference targets (5) around the cable reel (1) as target points, and transfer the central reference to the target points; Step 5: Using the center of the cable reel (1) as a reference, the laser tracker (4) measures the coordinates of the positioning target (6); based on the relative coordinates, hole distribution circle, hole diameter center distance, and angle deviation, determine the center position of some flange holes, mark the center positions of the upper flange holes and the lower flange holes together, and place the positioning target (6) at the center positions of the upper flange holes and the lower flange holes respectively. Step 6: Move the laser tracker (4) to determine the center of the cable reel (1) with the surrounding target points as a reference, and use this to determine the center position of the flange holes of the remaining parts on the upper flange (9) and lower flange (15); Step 7: Repeat step 6 until the center positions of all flange holes are located. Step 8: Install the machining fixture (7) at the center of the flange hole, adjust the verticality of the drill rod (8) and align it with the center of the flange hole; according to manpower and project progress, configure the corresponding number of machining fixtures (7) on the upper flange (9) and process the flange hole simultaneously; Step 9: Fix the boring machine (10), after machining the upper flange hole, replace the extended drill rod (8), check the center position of the lower flange hole, and then complete the machining of the lower flange hole.

2. The method for machining flange holes according to claim 1, characterized in that: In step three, the laser tracker (4) uniformly collects the three-dimensional spatial coordinates of multiple measuring points on the inner wall of the inner circle (2) of the cable reel (1); the measuring points on the same plane fit a standard circle, and the computer calculates the geometric center coordinates and radius of the inner circle (2) of the plane based on the measured data; the center of the fitted standard circle is the center reference of the cable reel (1).

3. The method for machining flange holes according to claim 1, characterized in that: In step three, the laser tracker (4) uniformly collects the three-dimensional spatial coordinates of multiple measuring points on the inner wall of the inner circle (2) of the cable reel (1); the measuring points on the same plane fit a standard circle, and the computer calculates the geometric center coordinates and radius of the inner circle (2) of the plane based on the measured data; the center of the fitted standard circle is the center reference of the cable reel (1); using the same set of measurement coordinate system, the three-dimensional coordinates of all the outer reference targets (5) are measured one by one.

4. The method for machining flange holes according to claim 1, characterized in that: In step four, the reference target (5) is arranged symmetrically around the circumference, with equal diameter and radial orientation, and then pasted on the ground.

5. The method for machining a flange hole according to claim 4, characterized in that: In step four, the laser tracker (4) measures the coordinates of the reference target (5), and a fixed spatial relationship of distance, azimuth angle and height difference is formed between the center of the cable reel (1) and each reference target (5); the center coordinate and the coordinates of each reference target (5) are converted to transfer the center reference to the target point; after the laser tracker (4) obtains the measured spatial coordinates of the positioning target (6), it calculates the center coordinates of the upper flange hole and the lower flange hole by converting the coordinates between the reference target (5) and the positioning target (6) in accordance with the drawing requirements.

6. The method for machining flange holes according to claim 1, characterized in that: In step five, several cement blocks (16) are set around the reference target (5), and the laser tracker (4) is placed on several of the cement blocks (16).

7. A method for machining flange holes according to claim 1, characterized in that: In step six, the laser tracker (4) is moved to the remaining cement block (16).

8. The machining fixture used in the method for machining a flange hole according to any one of claims 1-7, comprising a positioning target (6) and a boring machine (10), characterized in that: The boring machine (10) is equipped with a drill rod (8); the boring machine (10) is installed on one end face of the assembly plate (11), and the other end face of the assembly plate (11) is integrally formed with a right-angled positioning plate (12), the positioning plate (12) is provided with a fastening hole (13), and a fastener (14) is provided in the fastening hole (13); there is a gap between the assembly plate (11) and the positioning plate (12) to accommodate the upper flange (9); positioning targets (6) are arranged on both the upper flange (9) and the lower flange (15).

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