A method for processing a wellhead eccentric connector

Abstract

The application relates to the technical field of machining processes, and discloses a wellhead eccentric connecting piece machining method for machining a reducing eccentric connecting piece in sealing connection with a tubing hanger, the eccentric connecting piece comprising a connecting rod and a flange part eccentrically arranged at one end, the method comprising the following steps: S10, rough machining of a connecting rod end face, an outer circle and a through hole; S20, fine machining of a flange part end face, an outer circle and an adjusting hole; S30, machining of a pressure test side hole, a pressure test inclined side hole and a clearance part; and S40, fine machining of the connecting rod and the flange part; wherein S10, S20 and S30 are machined on a machining center, and then transferred to a lathe to complete S40 fine machining; the problems of low machining precision of common turning, high cost of special machining center equipment and low cost performance in the prior art are solved.

Description

Technical Field

[0001] This invention relates to the field of machining technology, specifically to a method for machining an eccentric wellhead connector. Background Technology

[0002] To ensure safety during oil production, wellhead equipment needs to be designed with an eccentric structure, with the eccentric reducing connector playing a major connecting role. However, due to their small batch size, high precision requirements, and difficult processing, the eccentric reducing connector requires high-precision machining equipment and cutting tools, resulting in high processing costs. Machining high-precision eccentric shafts has always been a challenge in the machinery industry, especially on ordinary lathes. There are several common methods for machining eccentric parts on lathes: three-jaw self-centering chuck with shims, double-center method, and adjustable fixture method. The most common method is the three-jaw self-centering chuck with shims, but this method has low precision and requires repositioning after each workpiece, resulting in low efficiency. The double-center method requires complex auxiliary work, has a narrow application range, low machining efficiency, high labor intensity, and demands high operator skill. Adjustable fixture methods, such as the eccentric shaft machining process described in CN102848145A, improve machining accuracy by using a dedicated eccentric fixture, but the fixture structure is complex, has poor stability, high manufacturing costs, low machining accuracy, high specialization, and limited applicability. In summary, ordinary lathes cannot meet the machining accuracy requirements of eccentric reducing joints. To achieve high-precision machining, the entire process needs to be completed in a multi-axis machining center. However, due to the small batch size, the machining center equipment is expensive, the cutting tools are complex, and an investment of tens of millions of dollars is required, resulting in high costs and low cost-effectiveness. Therefore, it is urgent for those skilled in the art to provide a new machining method to solve the above problems. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a method for machining eccentric wellhead connectors, which simplifies the machining process, eliminates the need for investing heavily in complex and high-precision machining centers, ensures high-precision machining of workpieces, improves production efficiency, significantly reduces production costs, and facilitates mass production. It overcomes the problems of low precision in conventional turning and high cost and low cost-effectiveness in machining centers used in existing technologies.

[0004] To achieve the above objectives, this application adopts the following technical solution.

[0005] This invention relates to a method for processing an eccentric wellhead connector, used to process a differential eccentric connector for sealing connection with a tubing hanger. The eccentric connector includes: a connecting rod and a flange portion eccentrically disposed at one end; a threaded connection portion at the other end of the connecting rod; a clearance portion between the threaded connection portion and the flange portion; a through hole at the center of the connecting rod; a countersunk head on the side of the through hole near the flange portion; an adjustment hole on the flange portion corresponding to the clearance portion; a test pressure side hole and a test pressure inclined side hole on both sides of the adjustment hole; an annular surface and an annular sealing groove on the outer end face of the flange portion; and a stepped portion on the cylindrical surface of the flange portion. The processing method includes the following steps: S10: Rough machining of the connecting rod end face, outer circle, and through hole; S20: Finish machining of flange end face, outer circle and adjustment hole; S30: Machining test pressure side holes, test pressure oblique side holes, and clearance parts; S40: Finished connecting rod and flange section; S10, S20, and S30 are machined on a machining center, and then transferred to a lathe to complete the finishing of S40.

[0006] Further: S10: Place the small end of the blank on the V-shaped frame of the machining center for leveling, adjust the center of the small end to be aligned with the center of the spindle and clamp it, rough machine the outer circle, end face and through hole, and leave machining allowance.

[0007] Further: The lathe is a horizontal lathe.

[0008] Further: S20 includes: S21: Keep the clamping in S10 unchanged, adjust the eccentricity to find the center of the large end flange and clamp it in place, and finish machine the inner end face of the flange. S22: Keeping the clamping unchanged, rotate the machining center table 180 degrees and machine a countersunk head that is coaxial with the through hole on the outer end face of the flange. S23: Keeping the clamping constant, perform precision machining on the outer circle, end face, and adjustment hole of the large end flange.

[0009] Further: S30 includes: S31: A circular groove concentric with the end face is machined on the flange end face; S32: Rotate the workpiece and machine the adjusting hole radial groove through the center of the flange face and the center of the adjusting hole; S33: Rotate the workpiece and machine the side pressure hole radial groove, the oblique side hole radial groove, the test pressure side hole, and the test pressure oblique side hole corresponding to the test pressure side hole and the test pressure oblique side hole through the center; S38: Adjust the adjustment hole ray groove to a horizontal state on the V-shaped frame, and machine the relief part corresponding to the adjustment hole on the connecting rod laterally and vertically.

[0010] Further: S33 includes: S34: Rotate the workpiece on the V-block, align the side pressure hole radial groove to a horizontal position, clamp it, process the test pressure side hole as required, and process the side hole platform surface set on the rear end face of the test pressure side hole; S36: Rotate the workpiece on the V-block, and clamp it after aligning the ray groove of the oblique side hole to a horizontal state. Rotate the worktable to align the tool with the axis of the test pressure oblique side hole, and process the test pressure oblique side hole as required. At the same time, process the oblique side hole platform surface and coaxial threaded hole on the rear end face of the test pressure oblique side hole.

[0011] Further: The test pressure side hole is composed of a straight hole at the front end of the flange and an oblique side hole at the rear end of the flange. After machining the test pressure side hole, the oblique side hole communicating with the straight hole is machined simultaneously. Since the central axis of the oblique side hole intersects with the central axis of the straight hole and the projections of the two axes are on the side pressure hole ray groove, the oblique side hole position is located with the leveled side pressure hole ray groove as a reference. The worktable is rotated to align the center of the tool with the center of the oblique side hole and the machining is completed. Then the side hole platform surface is machined.

[0012] Further: S40 includes: S41: Finishing the connecting rod: Place the workpiece completed in step S30 on the lathe, clamp the large diameter end with the lathe jaws and adjust the center of the small end, and then finish the outer cylindrical surface of the small end, the threads on the threaded connection part, the cylindrical annular groove, the through hole, the small end face and the small end face concave annular groove. S42: Maintain the above clamping, adjust and align the center of the large end, and finish machine the inner end face and step of the flange; S45: Finish machining of flange section: The workpiece is turned around, and the large diameter end is clamped and adjusted by the lathe jaws to align the center of the large end. The outer circular surface and end face of the flange section are finished, and the annular surface and annular sealing groove are removed. The machining reference datum composed of the annular groove, the adjusting hole radial groove, the side pressure hole radial groove and the oblique side hole radial groove are formed to form the abutment and installation limit groove of the oil pipe hanger.

[0013] Furthermore, the lathe chuck is designed as an eccentric chuck structure.

[0014] Compared with the prior art, the present invention has the following advantages: This application first performs rough milling on the small-diameter end on a conventional machining center, and then performs fine milling on the end face and outer circle reference for positioning of the large-diameter end. It provides an annular groove containing three holes: an adjustment hole, a test pressure side hole, and a test pressure oblique side hole, as well as three concentric radial grooves that are accurately positioned and machined on the connecting rod corresponding to the adjustment hole. The resulting "one circle and three rays" combined machining reference datum, which is at the same center, can accurately position and perform precise machining. Moreover, only one clamping and two centering adjustments are needed to complete the rough machining of the small end, the preliminary machining of the large end, and the positioning reference of the combination of various structures of the large end, as well as the machining of each hole. There is no need for repositioning; only the rotation and leveling of each reference ray groove is required for machining. This simplifies the machining process, reduces the cumulative error of repeated positioning, and thus improves the accuracy of product machining. The process is then transferred to a conventional lathe to machine the small and large diameter ends. This allows for efficient and accurate machining of relatively simple outer diameters and end faces. This method of using simple and commonly used milling and turning to simplify the process for machining complex workpieces eliminates the need for large and complex milling and turning machining centers, thus greatly saving on equipment investment costs. This process is both reasonable and simple. It can give full play to the advantages of high-precision positioning of CNC machining centers, and combine the high machining efficiency and good economy of ordinary lathes to process structures that are inconvenient to be machined by machining centers, such as the outer circle, end face, thread, gasket annular groove and end face sealing groove of eccentric connectors. This combined milling and turning method not only ensures high precision requirements and improves production efficiency, but also significantly reduces production costs, which helps to achieve mass production. Attached Figure Description

[0015] Figure 1 This is a three-dimensional schematic diagram of one side of the eccentric connector of the present invention; Figure 2 This is a three-dimensional schematic diagram of the other side of the eccentric connector of the present invention; Figure 3 This is a partial cross-sectional view of the eccentric connector of the present invention; Figure 4 This is a schematic diagram of the assembly of the eccentric connector of the present invention; Figure 5 This is a schematic diagram of the rough machining of the small-diameter end by the machining center of this invention; Figure 6 This is a schematic diagram of the machining center for precision machining of the large-diameter end, various hole positions, and machining reference datum of the present invention; Figure 7 yes Figure 6 Front view; Figure 8 This is a schematic diagram of the small-diameter end being precision machined on a lathe according to the present invention; Figure 9 This is a schematic diagram of the large-diameter end clamping process of the present invention on a lathe.

[0016] Attached image labels: Connecting rod 1; threaded connection part 11; clearance part 12; through hole 13; countersunk head 131; 2. Flange section; 21. Adjustment hole; 22. Test pressure side hole; 23. Test pressure oblique side hole; 24. Annular face; 25. Annular sealing groove; 26. Step section; 221. Straight hole section; 222. Oblique side hole; 223. Side hole platform surface; 232. Oblique side hole platform surface; 3. Worktable; 31. V-block; 32. Clamping structure; 4. Lathe chuck; 6. Oil pipe hanger; 7. Oil head pipe; 9. Oil pipe head set screw inner oil pipe; 10. Pressure gauge; 10. Small diameter outer circle d0; Small diameter end face d1; Large diameter outer circle D0; End face D1; Annular groove D2; Adjustment hole radial groove D3; Oblique side hole radial groove D4; Side pressure hole radial groove D5. Detailed Implementation

[0017] To enhance understanding of the present invention, the invention will be further described in detail below with reference to the accompanying drawings. This embodiment is only used to explain the invention and does not constitute a limitation on the scope of protection of the invention.

[0018] In the description of this invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", 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 combination 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 this invention.

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] Figure 1-9The diagram illustrates a method for machining an eccentric wellhead connector, used to machine a differential eccentric connector for sealing connection with a tubing hanger 6. As shown in Figures 1-4, the eccentric connector includes: a connecting rod 1 and a flange 2 eccentrically positioned at one end. The other end of the connecting rod 1 has a threaded connection 11, with a clearance portion 12 between the threaded connection 11 and the flange 2. The connecting rod 1 has a through hole 13 at its center, and a countersunk head 131 near the flange 2. The flange 2 corresponding to the clearance portion 12 has an adjusting hole 21, with a test pressure side hole 22 and a test pressure inclined side hole 23 on both sides of the adjusting hole 21. The outer end face of the flange 2 has an annular surface 24 and an annular sealing groove 25, and the cylindrical surface of the flange 2 has a stepped portion 26. The differential eccentric connector, composed of the connecting rod 1 and the flange 2, has its flange 2's top surface abutting against one end of the tubing hanger 6, and is securely sealed to the external eccentric connector via a connecting flange on the external oil head pipe 7. The flange connecting pipe 7 is also equipped with a tubing head set screw 8 to ensure a sealed connection between the flange and the tubing head, preventing oil and gas leakage. When the pressure inside the well increases, the set screw is supported by additional force to prevent the tubing from being pushed out due to excessive pressure. Pressure gauges 10 are installed on the test pressure side hole 22 and the test pressure inclined side hole 23 to test the gas pressure values ​​in different areas, which can promptly detect gas leakage inside the connection. The through hole 13 is connected to the hole on the tubing hanger 6 for connecting the inner tubing 9. The adjustment hole 21 is set to correspond to and communicate with one side hole of the tubing hanger 6. During installation, a gauge is used to measure whether there is any error in the fit between the adjustment hole 21 and the one side hole of the tubing hanger 6 and to adjust it, thereby ensuring that the through hole 13 and the inner tubing 9 are installed coaxially, accurately and reliably.

[0021] The processing method includes the following steps: S10: Rough machining of the end face, outer diameter, and through hole 13 of connecting rod 1; as shown in the example. Figure 5 As shown, the small end of the blank is placed on the V-shaped frame 31 on the machining center worktable 3 for leveling. The center of the small end is adjusted to coincide with the center of the spindle and the small diameter end is clamped by the clamping structure 32. The small diameter outer circle d0, the small diameter end face d1 and the through hole 13 are rough machined, and a machining allowance is left. The outer diameter of the connecting rod 1 is rough machined to be 168mm, the length is 50mm, and the machining allowance is 3mm. S20: Finish-machine the flange end face D1, outer diameter D0, and adjusting hole 21; specifically: such as... Figure 6 As shown, S20 includes: S21: Keep the clamping in S10 unchanged, find the center of the large end flange 2 by eccentric adjustment and clamp it in place, and finish machine the inner end face of the flange 2. S22: Keeping the clamping unchanged, rotate the machining center worktable 3 180 degrees and machine a countersunk head 131 that is coaxial with the through hole 13 on the outer end face of the flange 2. S23: Keeping the clamping unchanged, finish machine the outer circle D0, end face D1 and adjustment hole 21 of the large end flange 2; the outer circle D0 has a machining length of 50mm and a diameter of 420mm; S30: Machining the test pressure side hole 22, the test pressure oblique side hole 23, and the clearance part 12; specifically: such as Figure 6 , 7 As shown, S30 includes: S31: A circular groove D2 concentric with the end face is machined on the flange end face; S32: Rotate the workpiece and machine the adjusting hole groove D3 through the center of the flange face and the center of the adjusting hole 21; S33: Rotate the workpiece and machine the side pressure hole radial groove D5, the oblique side hole radial groove D4, the test pressure side hole 22, and the test pressure oblique side hole 23 corresponding to the test pressure side hole 22 and the test pressure oblique side hole 23 through the center. S38: Adjust the adjustment hole ray groove D3 to a horizontal state on the V-shaped frame, and machine the relief part 12 corresponding to the adjustment hole 21 on the connecting rod 1 from the side vertical direction; S40: Finish machining of connecting rod 1 and flange 2; specifically: such as... Figure 8 As shown, S40 includes: S41: Finishing connecting rod 1: Place the workpiece completed in step S30 on the lathe, clamp the large diameter end with the lathe jaws and adjust the center of the small end, and then finish the outer cylindrical surface of the small end, the thread on the threaded connection part 11, the cylindrical annular groove, the through hole 13, the small end face and the small end face concave annular groove. S42: Finished stepped section: such as Figure 8 As shown, while maintaining the above clamping, adjust and align the center of the large end, and finish machine the inner end face of the flange 2 and the step 26; S45: Finished flange part 2: such as Figure 9 As shown, the workpiece is turned around, and the large-diameter end is clamped and adjusted by the lathe jaws to align the center of the large end. The outer circular surface of the flange 2, the annular surface 24 and the annular sealing groove 25 on the end face are precision machined. The machining reference datum composed of the annular groove D2, the adjusting hole radial groove D3, the side pressure hole radial groove D5 and the oblique side hole radial groove D4 is removed to form the abutment and installation limiting groove of the oil pipe hanger. S42 and S45 can be followed by workpiece re-machining after changing the head.

[0022] S10, S20, and S30 are machined on a machining center and then transferred to a lathe for finishing. The lathe is a horizontal lathe, preferably a Rongtian VR38-1700 from Taiwan, China. The machining center is a conventional milling machining center, preferably a Doosan 80 machining center from South Korea.

[0023] This application first performs rough milling on the small-diameter end on a conventional machining center, and then performs fine milling on the end face and outer circle reference for positioning the large-diameter end. It provides a circular groove D2 containing three holes: an adjustment hole 21, a test pressure side hole 22, and a test pressure oblique side hole 23, as well as three concentric radial grooves that are accurately positioned and machined on the connecting rod corresponding to the adjustment hole 21. This forms a "one circle, three rays" combined machining reference datum with the same center, which can accurately position and perform precise machining. Moreover, only one clamping and two centering adjustments are needed to complete the rough machining of the small end, the preliminary machining of the large end, the positioning reference of the combination of various structures of the large end, and the machining of each hole. At the same time, there is no need to reposition; only the rotation and leveling of each reference ray groove is required for machining. This simplifies the machining process, reduces the cumulative error of repeated positioning, and thus improves the accuracy of product machining. The process is then transferred to a conventional lathe to machine the small and large diameter ends. This allows for efficient and accurate machining of relatively simple outer diameters and end faces. This method of using simple and commonly used milling and turning to simplify the process for machining complex workpieces eliminates the need for large and complex milling and turning machining centers, thus greatly saving on equipment investment costs. This process is both reasonable and simple. It can give full play to the advantages of high-precision positioning of CNC machining centers, and combine the high machining efficiency and good economy of ordinary lathes to process structures that are inconvenient to be machined by machining centers, such as the outer circle, end face, thread, gasket annular groove and end face sealing groove of eccentric connectors. This combined milling and turning method not only ensures high precision requirements and improves production efficiency, but also significantly reduces production costs, which helps to achieve mass production.

[0024] In one optional implementation, S33 includes: S34: Rotate the workpiece on the V-shaped frame, and clamp it after aligning the side pressure hole X-ray groove D5 to a horizontal state. Machin the test pressure side hole 22 as required, and machine the side hole platform surface 223 set on the rear end face of the test pressure side hole 22. S36: Rotate the workpiece on the V-block, and clamp it after aligning the oblique side hole radial groove D4 to a horizontal position. Rotate the worktable to align the tool with the axis of the test pressure oblique side hole 23, and process the test pressure oblique side hole 23 as required. At the same time, process the oblique side hole platform surface 232 and the coaxial threaded hole 231 on the rear end face of the test pressure oblique side hole 23.

[0025] In one optional embodiment, the test pressure side hole 22 is composed of a straight hole 221 provided at the front end of the flange 2 and an oblique side hole 222 provided at the rear end of the flange 2. After machining the test pressure side hole 22, the oblique side hole 222 communicating with the straight hole 221 is machined simultaneously. Since the central axis of the oblique side hole 222 intersects the central axis of the straight hole 221 and the projections of the two axes are both on the side pressure hole ray groove D5, the oblique side hole 222 is located with the leveled side pressure hole ray groove D5 as a reference. The worktable is rotated to align the center of the tool with the center of the oblique side hole 222 and the machining is completed. The oblique side hole 222 is a threaded hole. Then the side hole platform surface 223 is machined.

[0026] An optional implementation: the lathe jaw 4 is configured as an eccentric jaw structure; since the flange 2 is large in size and heavy in weight, in order to ensure clamping stability, the center of force is located at the center of the flange, and an eccentric four-jaw structure is preferred for clamping.

[0027] The embodiments disclosed herein are preferred embodiments, but are not limited thereto. Those skilled in the art can readily grasp the spirit of the present invention based on the above embodiments and make different extensions and variations, but as long as they do not depart from the spirit of the present invention, they are all within the protection scope of the present invention.

Claims

1. A method for machining an eccentric wellhead connector, used for machining a differential eccentric connector for sealing connection with a tubing hanger, characterized in that: The eccentric connector includes: a connecting rod (1) and a flange (2) eccentrically disposed at one end. The other end of the connecting rod (1) is provided with a threaded connection (11). A clearance portion (12) is provided between the threaded connection portion (11) and the flange (2). A through hole (13) is provided at the center of the connecting rod (1). A countersunk head (131) is provided on the side of the through hole (13) near the flange (2). An adjustment hole (21) is provided on the flange (2) corresponding to the clearance portion (12). A test pressure side hole (22) and a test pressure inclined side hole (23) are provided on both sides of the adjustment hole (21). An annular surface (24) and an annular sealing groove (25) are provided on the outer end face of the flange (2). A stepped portion (26) is provided on the cylindrical surface of the flange (2). The processing method includes the following steps: S10: Rough machining of the end face, outer circle and through hole (13) of the connecting rod (1); S20: Finished flange part (2) end face, outer circle and adjustment hole (21); S30: Machining the test pressure side hole (22), the test pressure oblique side hole (23), and the relief part (12); S40: Finishing the connecting rod (1) and flange (2); S10, S20, and S30 are processed on a machining center, and then transferred to a lathe to complete the finishing of S40; S30 includes: S31: A circular groove (D2) concentric with the end face is machined on the flange end face; S32: Rotate the workpiece and machine the adjustment hole radial groove (D3) through the center of the flange face and the center of the adjustment hole (21); S33: Rotate the workpiece and machine the side pressure hole radial groove (D5), the oblique side hole radial groove (D4), the test pressure side hole (22), and the test pressure oblique side hole (23) corresponding to the test pressure side hole (22) and the test pressure oblique side hole (23) through the center. S38: Adjust the adjustment hole ray groove (D3) to a horizontal state on the V-shaped frame, and machine the relief part (12) corresponding to the adjustment hole (21) on the connecting rod (1) from the side vertical. S40 includes: S41: Finishing the connecting rod (1): Place the workpiece completed in step S30 on the lathe, clamp the large diameter end with the lathe jaws (4) and adjust the center of the small end. Then finish the small end outer cylindrical surface, the thread on the threaded connection part (11), the cylindrical annular groove, the through hole (13), the small end face and the small end face concave annular groove. S42: Maintain the above clamping, adjust and align the center of the large end, and finish the inner end face of the flange part (2) and the step part (26). S45: Finishing flange part (2): The workpiece is turned around, and the large diameter end is clamped and adjusted by the lathe jaws (4). The outer circle surface (24) and the annular sealing groove (25) on the end face of the flange part (2) are finished. The machining reference datum composed of the annular groove (D2), the adjustment hole radial groove (D3), the side pressure hole radial groove (D5) and the oblique side hole radial groove (D4) is removed to form the limit groove part that abuts against the oil pipe hanger.

2. The method for processing eccentric connectors according to claim 1, characterized in that: S10: Place the small end of the blank on the V-shaped frame of the machining center for leveling, adjust the center of the small end to coincide with the center of the spindle and clamp it, rough machine the outer circle, end face and through hole (13), and leave machining allowance.

3. The method for processing eccentric connectors according to claim 1, characterized in that: The lathe is a horizontal lathe.

4. The method for processing eccentric connectors according to claim 1, characterized in that: S20 includes: S21: Keep the clamping in S10 unchanged, adjust the eccentricity to find the center of the large end flange (2) and clamp it to fix it, and finish machine the inner end face of the flange (2); S22: Keep the clamping unchanged, rotate the machining center table 180 degrees, and machine a countersunk head (131) that is coaxial with the through hole (13) on the outer end face of the flange (2). S23: Keep the clamping unchanged and finish machine the outer circle, end face and adjustment hole (21) of the large end flange (2).

5. The method for processing eccentric connectors according to claim 1, characterized in that: S33 includes: S34: Rotate the workpiece on the V-shaped frame, and clamp the side pressure hole radial groove (D5) after it is aligned to a horizontal position. Then, process the test pressure side hole (22) as required, and process the side hole platform surface (223) set on the rear end face of the test pressure side hole (22). S36: Rotate the workpiece on the V-shaped frame, and clamp the inclined side hole radial groove (D4) after it is aligned to a horizontal position. Rotate the worktable to align the tool with the axis of the test pressure inclined side hole (23). Machin the test pressure inclined side hole (23) as required. At the same time, machine the inclined side hole platform surface (232) and the coaxial threaded hole (231) on the rear end face of the test pressure inclined side hole (23).

6. The method for processing eccentric connectors according to claim 5, characterized in that: The test pressure side hole (22) is composed of a straight hole (221) at the front end of the flange (2) and an oblique side hole (222) at the rear end of the flange (2). After machining the test pressure side hole (22), the oblique side hole (222) communicating with the straight hole (221) is machined simultaneously. Since the central axis of the oblique side hole (222) intersects the central axis of the straight hole (221) and the projections of the two axes are on the side pressure hole ray groove (D5), the oblique side hole (222) is located with the leveled side pressure hole ray groove (D5) as the reference. The worktable is rotated to align the center of the tool with the center of the oblique side hole (222) and the machining is completed. Then the side hole platform surface (223) is machined.

7. The method for processing eccentric connectors according to claim 1, characterized in that: The lathe chuck (4) is designed as an eccentric chuck structure.

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