Hydraulic cylinder barrel processing

Cylinder barrel is the main component of hydraulic cylinder, mining single prop, hydraulic support, gun barrel and other products. Its processing quality directly affects the life and reliability of the entire product. The cylinder barrel has high processing requirements, its internal surface roughness is Ra0.4~0.8&um, and the requirements for coaxiality and wear resistance are strict. The basic feature of cylinder barrel is deep hole processing, which has always troubled the processing personnel.
Rolling processing is adopted, because the surface layer has residual compressive stress, which is helpful to seal the surface micro-cracks and hinder the expansion of erosion. Thus, the corrosion resistance of the surface can be improved, and the generation or expansion of fatigue cracks can be delayed, thus improving the fatigue strength of the cylinder barrel. Through rolling forming, a cold work hardening layer is formed on the rolling surface, which reduces the elastic and plastic deformation of the contact surface of the grinding pair, thus improving the wear resistance of the inner wall of the cylinder barrel, and avoiding the burn caused by grinding. After rolling, the reduction of surface roughness value can improve the fit property.
Cylinder is the most important part of construction machinery. The traditional processing method is: broaching cylinder block - fine boring cylinder block - grinding cylinder block. The rolling method is: broaching the cylinder block - fine boring the cylinder block - rolling the cylinder block. The process is three parts, but the time comparison: grinding the cylinder block for 1 meter takes about 1-2 days, and rolling the cylinder block for 1 meter takes about 10-30 minutes. Investment comparison: grinding machine or quilting machine (tens of thousands to millions), rolling knife (tens of thousands to tens of thousands). After rolling, the surface roughness of the hole is reduced from Ra3.2~6.3um before rolling to Ra0.4~0.8&um, the surface hardness of the hole is increased by about 30%, and the fatigue strength of the inner surface of the cylinder barrel is increased by 25%. If the service life of the cylinder is only considered, it will increase by 2-3 times, and the efficiency of the boring and rolling process will increase by about 3 times compared with the grinding process. The above data show that the rolling process is efficient and can greatly improve the surface quality of the cylinder barrel.
After the oil cylinder is rolled, there is no sharp edge on the surface, and the long time movement friction will not damage the seal ring or seal, which is particularly important in the hydraulic industry.