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Mechanical and electrical technical requirements

2018-04-27

1. Remove scale from parts.
1. Remove scale from parts.
2. Parts processing surface, there should be no scratches, scratches and other defects on the surface of the parts.
3. Remove the burr and flash.
4. After conditioning, HRC50 ~ 55.
5. Parts for high-frequency quenching, 350~370 ℃ tempering, HRC40 ~ 45.
6. Carburizing depth 0.3mm.
7. High temperature aging treatment.
8. The unmarked shape tolerance shall meet the requirements of the GB1184-80.
9. The allowable deviation of unnoted length dimension is ± 0.5mm.
10. The casting tolerance zone is symmetrical to the basic size configuration of the rough casting.
11. Unnoted fillet radius R5.
12. All unnoted chamfers are 2 × 45 °.
13. The acute angle is obtuse.
14. Each seal must be saturated with oil before assembly.
15. The assembly of rolling bearings allows the use of oil heating for hot loading, the oil temperature shall not exceed 100 ℃.
20. After the gear is assembled, the contact spots and backlash on the tooth surface should meet the requirements of the GB10095 and GB11365.
21. When assembling the hydraulic system, it is allowed to use sealing packing or sealant, but it should be prevented from entering the system.
22. Parts and components (including purchased parts and outsourced parts) that enter the assembly must have the certificate of conformity of the inspection department before assembly.
23. The parts must be cleaned and cleaned before assembly, and there must be no burrs, flash, oxide skin, rust, chips, oil stains, colorants and dust.
24. Before assembly, the main matching dimensions of parts and components, especially the interference fit dimensions and related accuracy, shall be reviewed.
25. Parts shall not be knocked, touched, scratched or rusted during assembly.
26. When tightening screws, bolts and nuts, it is strictly forbidden to hit or use inappropriate screwdrivers and wrenches. The screw groove, nut, screw and bolt head shall not be damaged after fastening.
27. Fasteners with specified tightening torque requirements must be tightened with a torque wrench according to the specified tightening torque.
28. When the same part is fastened with multiple screws (bolts), the screws (bolts) shall be tightened crosswise, symmetrically, step by step and evenly.
29. When assembling the taper pin, the hole should be painted and checked, and its contact rate should not be less than 60% of the matching length, and should be evenly distributed.
30. The flat key shall be in uniform contact with both sides of the keyway on the shaft, and there shall be no gap between the mating surfaces.
31. The number of tooth surfaces contacted by spline assembly at the same time shall not be less than 2/3, and the contact rate shall not be less than 50% in the length and height directions of key teeth.
32. After the flat key (or spline) of sliding fit is assembled, the corresponding parts can move freely without uneven tightness.
33. After bonding, the excess adhesive flowing out should be removed.
34. The semi-circular holes of the bearing outer ring, the open bearing seat and the bearing cover are not allowed to be stuck.
35. The outer ring of the bearing should be in good contact with the semi-circular hole of the open bearing seat and the bearing cover. When the color is used for inspection, it should be in uniform contact with the bearing seat at 120 ° symmetrical to the centerline and with the bearing cover at 90 ° symmetrical to the centerline. When checking with a feeler gauge within the above range, the 0.03mm feeler gauge shall not be inserted into 1/3 of the width of the outer ring.
36. The bearing outer ring shall be in uniform contact with the end face of the bearing cover at the positioning end after assembly.
37. After the rolling bearing is installed, the rotation by hand should be flexible and stable.
38. The joint surfaces of the upper and lower bearing bushes should be closely attached and checked with a 0.05mm feeler gauge.
39. When fixing the shaft tile with a positioning pin, the hinge and pin shall be drilled under the condition of ensuring that the opening surface and end surface of the tile are flush with the opening and closing surface and end surface of the relevant bearing hole. The pin shall not be loose after driving.
40. The bearing body of the spherical bearing shall be in uniform contact with the bearing seat, and the contact shall not be less than 70% by coloring inspection.
41. Alloy bearing lining surface yellow is not allowed to use, in the specified contact angle is not allowed to have nuclear phenomenon, in the contact angle outside the nuclear area shall not be greater than 10% of the total area of the non-contact area.
42. The reference end face of the gear (worm wheel) and the shaft shoulder (or the end face of the positioning sleeve) should be attached and cannot be checked with a 0.05mm feeler gauge. And should ensure that the gear reference end face and the axis of the verticality requirements.
43. The joint surface of the gear box and the cover should be in good contact.
44. Strictly check and remove the sharp angles, burrs and foreign objects remaining during parts processing before assembly. Make sure that the seal is not scratched when it is installed.
45. The surface of the casting is not allowed to have cold insulation, cracks, shrinkage and penetration defects and serious incomplete defects (such as under-casting, mechanical damage, etc.).
46. The casting shall be cleaned up without burrs or flash. The riser on the non-processing indication shall be cleaned up flush with the surface of the casting.
47. The casting characters and signs on the non-processed surface of the casting shall be clearly distinguishable, and the position and font shall meet the requirements of the drawing.
48. The roughness of the non-machined surface of the casting, sand casting R, is not more than 50μm.
49. Castings should be cleared of sprue, spines, etc. The residual amount of gate and riser on the non-processed surface should be leveled and polished to meet the surface quality requirements.
50. The casting sand, core sand and core bone should be removed.
51. The casting has inclined parts, and its size tolerance zone should be symmetrically arranged along the inclined surface.
52. The casting sand, core sand, core bone, fleshy, sticky sand, etc. should be shoveled and ground smoothly and cleaned.
53. The wrong type, boss casting deviation, etc. should be corrected to achieve a smooth transition, a guarantee of appearance quality.
54. The wrinkle on the non-machined surface of the casting shall have a depth of less than 2mm and a spacing of more than 100mm.
55. The non-machined surfaces of machine product castings are subject to shot peening or roller treatment to meet the requirements of cleanliness level Sa2 1/2.
56. Castings must be water-toughened.
57. The surface of the casting should be smooth, and the gate, burr, sticky sand, etc. should be removed.
58. Castings are not allowed to have casting defects such as cold insulation, cracks and holes that are detrimental to use.
59. Rust, oxide skin, grease, dust, soil, salt and dirt must be removed from all surfaces of steel and iron parts to be painted before painting.
60. Before derusting, remove grease and dirt on the surface of steel parts with organic solvents, lye, emulsifiers, steam, etc.
61. The time interval between the surface to be coated by shot peening or manual rust removal and the application of primer shall not be more than 6h.
62. The surfaces of riveting parts in contact with each other must be coated with a thickness of 30 ~ 40μm antirust paint before connection. Lap edges shall be closed with paint, putty or adhesive. Primer damaged due to processing or welding shall be recoated.
63. All pipes before assembly should be removed from the pipe end flash, burr and chamfer. Use compressed air or other methods to clear the debris and floating rust attached to the inner wall of the pipe.
64. Before assembly, all steel pipes (including prefabricated pipes) shall be degreased, pickled, neutralized, washed and rust-proof.
65. During assembly, tighten the parts fixed by threaded connection such as pipe clamps, supports, flanges and joints to prevent loosening.
66. The welding parts of the prefabricated pipe shall be subjected to pressure test.
67. When the pipe is replaced or transferred, the pipe separation port must be blocked and sealed with adhesive tape or plastic pipe to prevent any debris from entering, and the label must be fastened.
68. Defects must be completely removed before repair welding. The groove surface should be smooth and smooth without sharp corners.
69. According to the defects of cast steel parts, the defects in the repair welding area can be removed by shoveling, grinding, carbon arc gouging, gas cutting or machining.
70. The dirt such as sticky sand, oil, water and rust within 20mm around the repair welding area and groove must be thoroughly cleaned.
71. In the whole process of repair welding, the temperature of the preheating zone of cast steel parts shall not be lower than 350°C.
72. Where conditions permit, weld in a horizontal position as far as possible.
73. When repair welding, the welding rod should not do too much lateral swing.
74. When the surface of cast steel parts is stacked and welded, the overlap between welding passes shall not be less than 1/3 of the width of the welding pass.
75. The nozzle and riser of each ingot should have sufficient removal to ensure that the forgings are free of shrinkage and severe deflection.
76. Forgings should be forged on a forging press with sufficient capacity to ensure that the forgings are fully forged.
77. Forgings are not allowed to have visible cracks, folds and other appearance defects that affect the use. Local defects can be removed, but the depth of cleaning shall not exceed 75% of the machining allowance. Defects on the non-machined surface of forgings shall be cleaned and smooth.
78. Forgings are not allowed to have white spots, internal cracks and residual shrinkage holes.
81. The finished parts shall not be placed directly on the ground, and necessary support and protection measures shall be taken. The processing surface shall be free of rust, bumps, scratches and other defects that affect the performance, service life or appearance.
82. The surface of rolling finishing shall not have peeling phenomenon after rolling.
83. The surface of the part after the final process heat treatment should not have oxide skin. The finished mating surface and tooth surface shall not be annealed.
84. The processed thread surface is not allowed to have defects such as black skin, bumps, disorderly buckles and burrs.
85, blue, discoloration phenomenon