Technical Knowledge Of Precision Machining

- Feb 19, 2019 -

Technical knowledge of Precision Machining:

1). Part contouring: 1. The tolerances of non-injection positions should conform to the requirements of GB1184-80. 2, the allowable deviation of length dimension without injection is ±0.5 mm. 3, without a circular radius R5. 4, without chamfering are all C2. 5, the sharp angle is obtuse. 6, sharp edge is obtuse, remove burr fly edge.

2). Part surface treatment: 1, parts on the surface of precision machining, there should be no scratch, scratch and other damage to the surface of the parts defects. 2, the thread surface is not allowed to have black skin, bumps, buckles and burrs and other defects. All iron and steel surfaces requiring painting must be removed from rust, oxide, grease, dust, soil, salt and dirt before painting. 3, before rust removal, use organic solvents, lye, emulsifier, steam and so on to remove oil and dirt on the surface of iron and steel parts. 4, the time interval between the primer and the surface to be finished by shot peening or manual rust removal shall not be more than 6 hours. 

3). Heat treatment of parts: 1, after conditioning, HRC50~55. 2, medium carbon steel: 45 or 40Cr parts are quenched at high frequency, tempered at 350 ℃, HRC40~45. 3, Carburizing depth 0.3mm. 4. High temperature aging treatment was carried out. 

4).The technical requirements after finishing: 1. The parts after finishing should not be placed directly on the ground, and the necessary support and protection measures should be taken. 2. No rusting or damage to performance, life or appearance, scratches, etc. 3, roll the finish of the surface, after rolling must not have peeling phenomenon. 4, the final process after the heat treatment of the parts, the surface should not be oxidized. After precision machining of the matching surface, the tooth surface should not be annealed.

5).Technical requirements of assembly: 1. Parts and components entering assembly must have qualified report from inspection department to assemble. 2. Parts must be cleaned and cleaned before assembly, without burrs, flashes, oxide skins, rust, chips, oil stains, colorants and dust. 3. Check the main matching dimensions and relative precision of parts and components before assembly. Parts are not allowed to knock, touch, scratch and rust during assembly.

 6). Sealing treatment of parts: 1. Oil must be soaked before the sealing parts are assembled. 2. Check and remove the remaining sharp angles, burrs and foreign bodies before assembly. Ensure that the seal is not scratched when it is loaded. 3. The excess adhesive should be removed after bonding.