Comparison between grinding and rolling of the hot

  • Detail

Comparison between inner hole grinding and rolling

1 overview

in actual production, for surface roughness ra0.04 μ m~Ra1.6 μ M, the common machining processes are grinding, rolling, broaching, honing, etc. Broaching cutting tools cost a lot, have high production efficiency, and are suitable for mass production; Honing for finishing surface roughness ra0.04 μ M above. Therefore, grinding and rolling are commonly used. The following is a comparison between grinding and rolling by analyzing the processing technology of a part

2 process analysis

the part is shown in the figure, inner diameter φ 140+0.0630, roughness Ra0.08 μ M roundness tolerance 0.045mm

the original processing technology of Jinan assay low-temperature groove: Turning rough grinding fine grinding, turning grinding allowance 0.2mm ~ 0.4mm. This process can ensure the technical requirements of parts. Field test results: surface roughness Ra0.08 μ m. Dimension within tolerance φ 140~ φ Within the range of 140.063mm, the roundness tolerance is distributed within the range of 0 ~ 0.025mm. Grinding is high-speed cutting, which can be dispersed, reduce the surface roughness of parts, and improve the dimensional accuracy and geometric accuracy of parts. However, during the grinding process, due to the high grinding speed, a large amount of grinding heat is generated and transmitted to the parts, which makes the temperature of the parts rise by dozens of degrees, and the workpiece shrinks and the aperture shrinks after cooling (affected by the ambient temperature). In order to ensure the dimensional accuracy, the finished size needs to be manually adjusted, so the machining size is scattered. The high temperature in the grinding area (the local surface temperature can reach 1000 ℃) produces surface residual tensile stress, grinding cracks, burns, etc., which are very harmful to the service performance of parts; However, in actual production, it is difficult to reduce grinding heat by inner hole grinding; Grinding efficiency is low

current processing technology: rough turning - semi fine turning - fine turning - rolling, the parts can be processed on the lathe, and this technology can also fully meet the technical requirements of the parts. Field measurement results: surface roughness Ra0.08 μ m; Size distribution in φ 140.02mm~ φ Between 140.04mm, the processing size is relatively concentrated; The roundness tolerance is distributed within the range of 0.01 ~ 0.03mm. In order to ensure the quality of parts in the process of process execution, the turning requirements are very high, and the surface roughness of finished parts is ra3.2 μ m. Size φ. 01+0.02。 Because the actual pressing amount of rolled parts is very small, and the processing depends on the self positioning of the machined surface of the parts, it can reduce the surface roughness of the parts and improve the dimensional accuracy, but the shape deviation of the parts will not be significantly improved. Therefore, the accuracy of the parts after rolling is mainly determined by the accuracy of the third-generation semiconductor design, materials, processes and utilization as the main target (turning) before the parts are rolled Surface roughness. Rolling processing is chip free processing without heating. The finished size is the forming size, and the processing size is easy to control. The surface layer of rolled parts produces residual compressive stress and cold hardening, which can improve the fatigue strength of parts and have high production efficiency. However, rolling tools need to be made

3 process comparison

inner hole grinding process and rolling process can be mentioned as widely used plastic packaging materials for carbonated beverages, beer, edible oil and so on; Electrical materials; High dimensional accuracy of parts and reduced surface roughness. However, there are the following differences:

inner hole grinding has low requirements for the previous process, and can achieve higher accuracy than rolling. In actual production, it is difficult to reduce the temperature in the grinding area during the internal hole grinding process. The residual tensile stress, grinding cracks, burns, etc. produced by the machined surface layer affect the service performance of parts, and the production efficiency is low

rolling processing has high requirements for the previous process and cannot improve the shape accuracy of parts. Because there is no heating in the processing process, the size is easy to control; The residual compressive stress and cold hardening produced by the machined surface layer of parts are conducive to improving the service performance of parts; High production efficiency

4 conclusion

through the above analysis and comparison, it can be seen that the inner hole roughness Ra0.08 μ m~Ra1.6 μ M range, finalized products, mass production, we should carefully understand the rolling process. Compared with grinding, the process has the following advantages:

the production efficiency is improved several times

simple process

the service performance of parts is improved

reducing the number of transfers is beneficial to prevent bumps. (end)

Copyright © 2011 JIN SHI