Heating base supporting rod hole repairing accessory and repairing method

Abstract

The invention relates to the technical field of heating base equipment, in particular to a heating base supporting rod hole repairing accessory and method, and the heating base supporting rod hole repairing accessory comprises a heating base (1); a mounting hole (2) is formed in the heating base (1); a cold insert (3) and a limiting structure are respectively arranged in the mounting hole (2); the cold insert (3) is propped against the limiting structure; an original supporting rod hole area of the heating base is completely cut off, a mounting hole is machined in the cut-off area, meanwhile, a cold insert is designed and manufactured, and the cold insert is mounted in the mounting hole, so that repairing work can be completed; the rest structures of the heating base are completely reserved, so that the cost is greatly reduced; and meanwhile, after the supporting rod hole site on the cold insert is worn again, the damaged cold insert is taken out, and a new cold insert is mounted again, so that the heating base can recover to work, the service life of the heating base can be greatly prolonged, and meanwhile, the subsequent maintenance cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of heating base equipment, and in particular to a heating base support rod hole repair accessory and a repair method. Background Art

[0002] Susceptor (heating base) is one of the most important parts in CVD (chemical vapor deposition) related equipment. Its reference surface is in direct contact with the liquid crystal glass substrate to heat it. Since the process requires high precision, the processing accuracy of the reference surface is also very high. During frequent use, it is easy to produce peeling and a large number of dust particles, which pollute the CVD (chemical vapor deposition) chamber environment and cause many defects in product film formation. If similar defects occur, regeneration treatment must be carried out. Therefore, it is necessary to make a high temperature resistant, corrosion resistant, friction resistant, and insulating anodized film on the surface of the product. By regularly updating the film layer, an excellent film forming environment is provided and the service life of the cavity is increased.

[0003] In the process of updating the film layer, the old film layer, surface oxides and other contaminants need to be peeled off to achieve the purpose of cleaning, otherwise the film quality and use effect of the product will be seriously affected. This process will wear the metal substrate of the Susceptor (heating base), and the support rod hole (Golf Tee Hole) will also be worn synchronously, resulting in hole expansion, which will eventually exceed the normal use standard and cause MURA (uneven display brightness) caused by uneven film formation. The Susceptor (heating base) cannot work normally, and finally the product is scrapped, the cost of raw materials increases, and a lot of time and cost are wasted.

[0004] After searching, the applicant found that the Chinese patent document with publication number 103717784A disclosed on April 9, 2014 a CVD device, a method for manufacturing a base using the CVD device, and a base, which can dramatically improve the quality and productivity of a base formed with a coating of SiC, TaC, etc. without causing an increase in production costs and enlargement of the device, a mask portion (recessed portion) is arranged in the central portion of the back side of the carbonaceous substrate; the mask portion is composed of a first hole portion and a second hole portion; an internal thread portion is formed on the inner wall of the first hole portion; the external thread portion of the mask fixture is screwed into the internal thread portion; the mask fixture is fixed to a fixture for forming a coating; the device also cannot solve the above-mentioned technical problems.

[0005] Therefore, in order to improve or solve at least one of the above problems, it is necessary to provide a heating base support rod hole repair accessory and repair method that can efficiently repair the worn support rod hole and avoid uneven film formation of the product. Summary of the invention

[0006] The object of the present invention is to provide a heating base support rod hole repair accessory and a repair method that can efficiently repair worn support rod holes and avoid uneven film formation of products.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is: a heating base support rod hole repair accessory, including a heating base; a mounting hole is provided in the heating base; a cold insert and a limiting structure are respectively provided in the mounting hole; the cold insert is tightly pressed against the limiting structure.

[0008] The cold insert includes a larger end and a smaller end; the mounting hole includes a first mounting hole and a second mounting hole; the limiting structure includes a limiting block; the limiting block is arranged along the inner wall of the first mounting hole and connected to the top of the second mounting hole; the larger end is arranged in the first mounting hole; the smaller end is arranged in the second mounting hole.

[0009] A void groove is provided on one side of the heating base; a reference surface is provided on the other side of the heating base; the void groove is connected to the second mounting hole; a bushing mounting hole is provided in the smaller end portion; a bushing is provided in the bushing mounting hole; fixing bolt holes are respectively provided on both sides of the bushing mounting hole; a bolt is provided on the bushing, and the bolt is connected in the fixing bolt hole.

[0010] A bushing head mounting hole is provided on one side of the bushing mounting hole; a support rod head supporting hole is provided on one side of the bushing head mounting hole; a support rod head matching hole is provided on one side of the support rod head supporting hole; and the support rod head matching hole is connected to the reference surface.

[0011] A connecting section is provided on one side of the larger end portion; a connecting threaded hole is provided on the connecting section.

[0012] A method for repairing the heating base support rod hole repair accessory, the method comprising the following steps:

[0013] 1) preparing a cold insert; and immersing the cold insert in liquid nitrogen at normal pressure;

[0014] 2) removing the damaged support rod hole on the heating base and processing the mounting hole; performing rough processing and fine processing on the first mounting hole and the second mounting hole respectively;

[0015] 3) Installing the cold insert in the mounting hole; cutting off the connecting section, and processing the bushing mounting hole, the bushing head mounting hole, the support rod head supporting hole and the support rod head matching hole.

[0016] The step 1) comprises:

[0017] 11) The cold insert is made of AL6061 aluminum; the overall height of the cold insert is 53mm-70mm; the diameter of the larger end is 33mm-60mm, and the height is 10mm-47mm; the diameter of the smaller end is 29mm-56mm, and the height is 43mm-60mm; a connecting section is machined on one side of the larger end; a connecting threaded hole is machined on the connecting section; the cold insert is completely placed in liquid nitrogen at normal pressure, the liquid nitrogen level exceeds the top of the cold insert by at least 10mm, and the immersion time is more than 20 minutes.

[0018] The step 2) comprises:

[0019] 21) Use a D8-20mm roughing end mill to perform rough machining on the first mounting hole and the second mounting hole by plane profile milling or hole milling on the reference plane; the side margins of the first mounting hole and the second mounting hole are both 0.1mm-0.5mm; the diameter depth of the first mounting hole is 10mm-47mm, and the second mounting hole penetrates the air avoidance groove;

[0020] 22) Use a D12-20mm finishing end mill to remove the side margins of the first mounting hole and the second mounting hole by plane contour milling or hole milling.

[0021] The step 3) comprises:

[0022] 31) Take the cold insert out of the normal pressure liquid nitrogen and immediately install it in the installation hole. The installation process must be completed within 10 seconds, otherwise it will lead to installation failure;

[0023] 32) Use a D8-20mm rough machining end mill or face mill to cut the connecting section, and stop machining when the distance to the reference plane is 0.5mm-2mm; use a hammer to knock the edge of the larger end to rivet it with the first mounting hole;

[0024] 33) Use a D12-20mm finishing end mill or face mill to remove the residual material of the connecting section; the depth spacing between the surface of the larger end and the reference plane is ±0.02mm, and then use a D4-8mm finishing end mill to respectively process the bushing mounting hole, the bushing head mounting hole, the support rod head support hole and the support rod head matching hole.

[0025] The step 3) comprises:

[0026] 34) using a polishing machine to perform local polishing on the area of ​​about 100 mm from the center of the larger end;

[0027] 35) Use 20# sand material to manually perform local sandblasting on the larger end.

[0028] The beneficial effects of this application are:

[0029] The present application provides a method for repairing a support rod hole of a heating base and a cold insert structure used during the repair. After the support rod hole of the heating base is worn and expanded, continued production will cause uneven film formation of the product, resulting in product scrapping. Because the conventional heating base and the support rod hole are an integrated structure, it is usually chosen to directly replace the new heating base and directly scrap the old heating base. This solution leads to a significant increase in production costs.

[0030] In this application, the original support rod hole area is completely cut out, a mounting hole is machined in the cut-out area, and a cold insert is designed and manufactured at the same time, and the cold insert is installed in the mounting hole; support rod holes of the same specification are machined on the cold insert to complete the repair work; with this solution, the remaining structure of the heating base is completely retained, which greatly reduces the cost; at the same time, when the support rod hole on the cold insert is worn again, the damaged cold insert is removed and a new cold insert is reinstalled to resume work, which can greatly increase the service life of the heating base and reduce subsequent maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The specific embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings, wherein:

[0032] Figure 1 This is a schematic structural diagram of the cold insert of the heating base support rod hole repair accessory and repair method.

[0033] Figure 2 This is a schematic diagram of the repair completion state of the heating base of the heating base support rod hole repair accessories and repair method.

[0034] Figure 3 This is a structural schematic diagram of the mounting hole of the heating base support rod hole repair accessory and repair method.

[0035] The marks in the above figure are:

[0036] The markings in the figure are:

[0037] 1. Heating base, 101. Air-avoiding groove, 102. Reference surface,

[0038] 2. Mounting hole, 201. First mounting hole, 202. Second mounting hole, 203. Limiting block,

[0039] 3. Cold inserts,

[0040] 4. Larger end, 401. Bushing head mounting hole, 402. Support rod head support hole, 403. Support rod head matching hole, 404. Connecting section, 405. Connecting threaded hole,

[0041] 5. Smaller end, 501. Bushing mounting hole, 502. Bushing, 503. Fixing bolt hole. DETAILED DESCRIPTION

[0042] The specific implementation methods of the present invention are further explained in detail below by describing the embodiments with reference to the accompanying drawings, with the aim of helping those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention and facilitating their implementation.

[0043] Figure 1 The heating base support rod hole repair accessory shown includes a heating base 1; a mounting hole 2 is provided in the heating base 1; a cold insert 3 and a limiting structure are respectively provided in the mounting hole 2; and the cold insert 3 is tightly pressed against the limiting structure.

[0044] The original support rod hole area of ​​the heating base 1 is completely cut out, and the mounting hole 2 is processed in the cut-out area. At the same time, a cold insert 3 is designed and manufactured, and the cold insert 3 is installed in the mounting hole 2 to complete the repair work; the remaining structure of the heating base 1 is completely retained, which greatly reduces the cost; at the same time, when the support rod hole on the cold insert 3 is worn again, the damaged cold insert 3 is taken out and a new cold insert 3 is reinstalled to resume work, which can greatly increase the service life of the heating base 1 and reduce the subsequent maintenance cost.

[0045] The cold insert 3 includes a larger end 4 and a smaller end 5; the mounting hole 2 includes a first mounting hole 201 and a second mounting hole 202; the limiting structure includes a limiting block 203; the limiting block 203 is arranged along the inner wall of the first mounting hole 201 and connected to the top of the second mounting hole 202; the larger end 4 is arranged in the first mounting hole 201; the smaller end 5 is arranged in the second mounting hole 202.

[0046] The larger end 4 and the smaller end 5 are an integral structure and are both cylindrical structures; the diameter of the first mounting hole 201 is larger than that of the second mounting hole 202; the limiting block 203 is arranged at the bottom of the first mounting hole 201 and is connected to the top of the second mounting hole 202, thereby forming a step structure between the first mounting hole 201 and the second mounting hole 202, and when the cold insert 3 is installed in the mounting hole 2, the bottom surface of the larger end 4 presses against the limiting block 203, thereby preventing the cold insert 3 from falling off from the bottom of the mounting hole 2 during operation.

[0047] A void groove 101 is provided on one side of the heating base 1; a reference surface 102 is provided on the other side of the heating base 1; the void groove 101 is connected to the second mounting hole 202; a bushing mounting hole 501 is provided in the smaller end 5; a bushing 502 is provided in the bushing mounting hole 501; fixing bolt holes 503 are respectively provided on both sides of the bushing mounting hole 501; bolts are provided on the bushing 502, and the bolts are connected to the fixing bolt holes 503.

[0048] The air avoidance groove 101 is arranged on the bottom surface of the heating base 1; the reference surface 102 is arranged on the top surface of the heating base 1 and is in direct contact with the liquid crystal glass substrate product; the bushing mounting hole 501 is a round hole; the bushing mounting hole 501 passes through the smaller end portion 5, and part of the bushing mounting hole 501 is arranged in the larger end portion 4; a bushing 502 is installed in the bushing mounting hole 501; the bushing 502 is a golf tee bushing, and its internal structure includes a short pin (a support rod supporting the liquid crystal glass substrate) and a small roller, and the short pin (the support rod supporting the liquid crystal glass substrate) and the small roller can slide up and down in the bushing 502; a bolt is connected to the bushing 502, and the bolt is installed in the fixing bolt hole 503, so that the bushing 502 can be stably fixed in the bushing mounting hole 501.

[0049] A bushing head mounting hole 401 is provided on one side of the bushing mounting hole 501; a support rod head supporting hole 402 is provided on one side of the bushing head mounting hole 401; a support rod head matching hole 403 is provided on one side of the support rod head supporting hole 402; and the support rod head matching hole 403 is connected to the reference surface 102.

[0050] The bushing head mounting hole 401 is arranged at the top of the bushing mounting hole 501 and is connected with the bushing mounting hole 501; the support rod head support hole 402 is arranged between the bushing head mounting hole 401 and the support rod head matching hole 403, and is respectively connected with the bushing head mounting hole 401 and the support rod head matching hole 403; the diameter of the bushing head mounting hole 401 is smaller than the bushing mounting hole 501; the diameter of the support rod head support hole 402 is smaller than the bushing head mounting hole 401; the diameter of the support rod head matching hole 403 is larger than the support rod head support hole 402.

[0051] A connecting section 404 is provided on one side of the larger end portion 4 ; a connecting threaded hole 405 is provided on the connecting section 404 .

[0052] The connecting section 404 is an integral structure with the larger end 4 and is arranged at one end of the larger end 4 away from the smaller end 5; the cold insert 3 needs to be immersed in liquid nitrogen, and the connecting threaded hole 405 is connected to the threaded rod. The staff can hold the threaded rod to facilitate the transfer operation of the cold insert 3.

[0053] A method for repairing a heating base support rod hole repair accessory, the method comprising the following steps:

[0054] 1) preparing a cold insert 3; and immersing the cold insert 3 in liquid nitrogen at normal pressure;

[0055] 2) The damaged support rod hole on the heating base 1 is removed, and the mounting hole 2 is processed; the first mounting hole 201 and the second mounting hole 202 are respectively rough-processed and fine-processed in sequence;

[0056] 3) Install the cold insert 3 in the mounting hole 2; cut off the connecting section 404, and process the bushing mounting hole 501, the bushing head mounting hole 401, the support rod head support hole 402 and the support rod head matching hole 403.

[0057] The above steps illustrate the processing and installation method of the cold insert 3 and the mounting hole 2: the original support rod hole area of ​​the heating base 1 is completely cut out, the mounting hole 2 is processed in the cut-out area, and the cold insert 3 is designed and manufactured at the same time. The cold insert 3 is installed in the mounting hole 2 to complete the repair work; the remaining structure of the heating base 1 is completely retained, which greatly reduces the cost; at the same time, when the support rod hole on the cold insert 3 is worn again, the damaged cold insert 3 is removed and a new cold insert 3 is reinstalled to resume work, which can greatly increase the service life of the heating base 1 and reduce the subsequent maintenance cost.

[0058] Step 1) includes:

[0059] 11) The cold insert 3 is made of AL6061 aluminum; the overall height of the cold insert 3 is 53mm-70mm; the diameter of the larger end 4 is 33mm-60mm, and the height is 10mm-47mm; the diameter of the smaller end 5 is 29mm-56mm, and the height is 43mm-60mm; a connecting section 404 is machined on one side of the larger end 4; a connecting threaded hole 405 is machined on the connecting section 404; the cold insert 3 is completely placed in liquid nitrogen at normal pressure, the liquid nitrogen level exceeds the top of the cold insert 3 by at least 10mm, and the immersion time is more than 20 minutes.

[0060] The cold insert 3 is made of the same AL6061 aluminum material as the heating base 1; after the cold insert 3 is processed to its strict installation dimensions, it is placed in liquid nitrogen at normal pressure for cooling. At this time, the volume of the cold insert 3 will shrink, making it easier to install it in the installation hole 2; at room temperature, the cold insert 3 will restore its size to ensure that the cold insert 3 is tightly combined with the installation hole 2 without any gap.

[0061] Step 2) includes:

[0062] 21) Use a D8-20mm roughing end mill to perform rough machining on the first mounting hole 201 and the second mounting hole 202 by plane profile milling or hole milling on the reference surface 102; the side margins of the first mounting hole 201 and the second mounting hole 202 are both 0.1mm-0.5mm; the diameter depth of the first mounting hole 201 is 10mm-47mm, and the second mounting hole 202 penetrates the air avoidance groove 101;

[0063] 22) Use a D12-20 mm finishing end mill to remove the side margins of the first mounting hole 201 and the second mounting hole 202 by plane contour milling or hole milling.

[0064] The temperature of liquid nitrogen under normal pressure is -196°C, and the expansion coefficient of AL6061 is 23.6X10-6 1 / K. According to this condition, in step 21), the first mounting hole 201 and the second mounting hole 202 are roughly machined corresponding to the larger end 4 diameter and the smaller end 5 diameter of the cold insert 3 that become smaller after being immersed in liquid nitrogen, and then the first mounting hole 201 and the second mounting hole 202 are finely machined in step 22); the production efficiency and processing quality can be effectively improved; the excess material can be quickly removed by rough machining, which can reduce the time and cost of fine machining, and at the same time reduce tool wear and machine tool load.

[0065] Step 3) includes:

[0066] 31) Take out the cold insert 3 from the normal pressure liquid nitrogen and immediately install it in the installation hole 2. The installation process must be completed within 10 seconds, otherwise it will lead to installation failure;

[0067] 32) Use a D8-20mm roughing end mill or face mill to cut the connecting section 404, and stop processing when it is 0.5mm-2mm above the reference surface 102; use a hammer to knock the edge of the larger end 4 to rivet it with the first mounting hole 201;

[0068] 33) Use a D12-20mm finishing end mill or face mill to remove the residual material of the connecting section 404; the depth spacing between the surface of the larger end 4 and the reference plane 102 is ±0.02mm, and then use a D4-8mm finishing end mill to respectively process the bushing mounting hole 501, the bushing head mounting hole 401, the support rod head support hole 402 and the support rod head matching hole 403.

[0069] In step 31), after the cold insert 3 is taken out from the liquid nitrogen at normal pressure, it will restore its shape in a short time. If the installation is not completed within 10 seconds, it will not be able to be installed in the mounting hole 2; in step 32), after the connecting section 404 is cut off, the edge of the cold insert 3 is knocked and riveted with a hammer or other tool to strengthen the bonding between the cold insert 3 and the reference surface 102; in step 33), the top surface of the larger end 4 is finely processed to ensure that the surface of the larger end 4 is consistent with the flatness of the reference surface 102.

[0070] Step 3) includes:

[0071] 34) Use a polishing machine to perform local polishing on the area of ​​about 100 mm from the center of the larger end 4;

[0072] 35) Use 20# abrasive material to manually perform local sandblasting on the larger end 4.

[0073] In step 34), a pneumatic or electric polishing machine is used to locally polish the area near the installation position of the larger end 4 to ensure that the flatness of the larger end 4 is consistent with that of the reference surface 102; in step 35), the larger end 4 is locally sandblasted manually to ensure that the roughness of the larger end 4 is consistent with that of the reference surface 102.

[0074] The specific workflow of the present invention is as follows:

[0075] 1) preparing a cold insert 3; and immersing the cold insert 3 in liquid nitrogen at normal pressure;

[0076] 2) The damaged support rod hole on the heating base 1 is removed, and the mounting hole 2 is processed; the first mounting hole 201 and the second mounting hole 202 are respectively rough-processed and fine-processed in sequence;

[0077] 3) Install the cold insert 3 in the mounting hole 2; cut off the connecting section 404, and process the bushing mounting hole 501, the bushing head mounting hole 401, the support rod head support hole 402 and the support rod head matching hole 403.

[0078] The present invention is described above by way of example in conjunction with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-mentioned methods. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention; or the above concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A heating base support rod hole repair accessory, characterized in that: It comprises a heating base (1); a mounting hole (2) is provided in the heating base (1); a cold insert (3) and a limiting structure are respectively provided in the mounting hole (2); and the cold insert (3) is tightly pressed against the limiting structure.

2. A heating base support rod hole repair accessory according to claim 1, characterized in that: The cold insert (3) comprises a larger end (4) and a smaller end (5); the mounting hole (2) comprises a first mounting hole (201) and a second mounting hole (202); the limiting structure comprises a limiting block (203); the limiting block (203) is arranged along the inner wall of the first mounting hole (201) and is connected to the top of the second mounting hole (202); the larger end (4) is arranged in the first mounting hole (201); and the smaller end (5) is arranged in the second mounting hole (202).

3. A heating base support rod hole repair accessory according to claim 2, characterized in that: A clearance groove (101) is provided on one side of the heating base (1); a reference surface (102) is provided on the other side of the heating base (1); the clearance groove (101) is communicated with the second mounting hole (202); a bushing mounting hole (501) is provided in the smaller end portion (5); a bushing (502) is provided in the bushing mounting hole (501); fixing bolt holes (503) are respectively provided on both sides of the bushing mounting hole (501); a bolt is provided on the bushing (502), and the bolt is connected to the fixing bolt hole (503).

4. A heating base support rod hole repair accessory according to claim 3, characterized in that: A bushing head mounting hole (401) is provided on one side of the bushing mounting hole (501); a support rod head supporting hole (402) is provided on one side of the bushing head mounting hole (401); a support rod head matching hole (403) is provided on one side of the support rod head supporting hole (402); and the support rod head matching hole (403) is connected to the reference surface (102).

5. A heating base support rod hole repair accessory according to any one of claims 2 to 4, characterized in that: A connecting section (404) is provided on one side of the larger end portion (4); a connecting threaded hole (405) is provided on the connecting section (404).

6. A method for repairing the heating base support rod hole repair accessory according to any one of claims 1 to 5, characterized in that: The repair method comprises the following steps: 1) preparing a cold insert (3); and immersing the cold insert (3) in liquid nitrogen at normal pressure; 2) removing the damaged support rod hole on the heating base (1) and machining a mounting hole (2); and performing rough machining and fine machining on the first mounting hole (201) and the second mounting hole (202) respectively; 3) installing the cold insert (3) in the mounting hole (2); cutting off the connecting section (404), and processing the bushing mounting hole (501), the bushing head mounting hole (401), the support rod head supporting hole (402) and the support rod head matching hole (403).

7. The repair method according to claim 6, characterized in that: The step 1) comprises: 11) The cold insert (3) is made of AL6061 aluminum material; the overall height of the cold insert (3) is 53mm-70mm; the diameter of the larger end (4) is 33mm-60mm, and the height is 10mm-47mm; the diameter of the smaller end (5) is 29mm-56mm, and the height is 43mm-60mm; a connecting section (404) is machined on one side of the larger end (4); a connecting threaded hole (405) is machined on the connecting section (404); the cold insert (3) is completely placed in liquid nitrogen at normal pressure, the liquid nitrogen level exceeds the top of the cold insert (3) by at least 10mm, and the immersion time is more than 20 minutes.

8. The repair method according to claim 7, characterized in that: The step 2) comprises: 21) using a D8-20mm roughing end mill to perform rough machining on the first mounting hole (201) and the second mounting hole (202) on the reference surface (102) by plane profile milling or hole milling; the side margins of the first mounting hole (201) and the second mounting hole (202) are both 0.1mm-0.5mm; the diameter depth of the first mounting hole (201) is 10mm-47mm, and the second mounting hole (202) penetrates the air avoidance groove (101); 22) Using a D12-20 mm finishing end mill to remove the side margins of the first mounting hole (201) and the second mounting hole (202) by plane contour milling or hole milling.

9. The repair method according to any one of claims 7-8, characterized in that: The step 3) comprises: 31) Take the cold insert (3) out of the normal pressure liquid nitrogen and immediately install it in the installation hole (2). The installation process must be completed within 10 seconds, otherwise it will lead to installation failure; 32) using a D8-20mm rough machining end mill or face mill to cut the connecting section (404), and pausing the machining when the distance from the connecting section to the reference surface (102) is 0.5mm-2mm; using a hammer to knock the edge of the larger end (4) to rivet it with the first mounting hole (201); 33) Use a D12-20mm finishing end mill or face mill to remove the residual material of the connecting section (404); the depth spacing between the surface of the larger end (4) and the reference plane (102) is ±0.02mm, and then use a D4-8mm finishing end mill to respectively process the bushing mounting hole (501), the bushing head mounting hole (401), the support rod head support hole (402) and the support rod head matching hole (403).

10. The repair method according to claim 9, characterized in that: The step 3) comprises: 34) using a polishing machine to perform local polishing on the area of ​​the larger end (4) with a central diffusion area of ​​about 100 mm; 35) Use 20# sand material to manually perform local sandblasting on the larger end (4).

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