Cylinder Barrel Processing of Hydraulic Cylinder

Buffering Device

In the hydraulic system using hydraulic cylinder drive with a certain mass of the body, when the hydraulic cylinder movement to the end of the stroke has a large kinetic energy, such as not deceleration, hydraulic cylinder piston and cylinder head will occur mechanical collision, impact, noise, destructive. In order to moderate and prevent the occurrence of this hazard, so you can set up a deceleration device in the hydraulic circuit or set up a buffer device in the cylinder body. The hydraulic cylinder is part of the hydraulic parts.

Cylinder Processing

Hydraulic cylinder barrel as the main parts of hydraulic cylinder, mining monoblock pillar, hydraulic support, gun pipe and other products, its processing quality directly affects the life and reliability of the whole product. Cylinder barrel processing requirements are high, its internal surface roughness requirements for Ra0.4 ~ 0.8&um, strict requirements for coaxiality, wear resistance. The basic feature of cylinder barrel is deep hole processing, and its processing has been troubling the processors.

Adopting rolling processing, because the surface layer leaves surface residual compressive stress, it helps to close the surface tiny cracks and hinder the expansion of erosion effect. This improves the surface corrosion resistance and delays the generation or expansion of fatigue cracks, thus increasing the fatigue strength of the cylinder. Through roll forming, a cold work-hardened layer is formed on the rolled surface, which reduces the elastic and plastic deformation of the contact surface of the grinding sub, thus improving the wear resistance of the cylinder barrel inner wall and avoiding the burn caused by grinding at the same time. The reduction of surface roughness value after rolling improves the nature of the fit.

Cylinder is the most important part of construction machinery, the traditional processing method is: broaching cylinder block - fine boring cylinder block - grinding cylinder block. Using rolling method is: broaching cylinder block - fine boring cylinder block - rolling cylinder block, the process is 3 parts, but the time comparison: grinding cylinder block 1 meter in about 1-2 days time, rolling cylinder block 1 meter in about 10-30 minutes time. Input comparison: grinder or quilting mill (tens of thousands - millions), hobbing tool (1 thousand - tens of thousands). After rolling, the hole surface roughness is reduced from Ra3.2~6.3um to Ra0.4~0.8&um before block rolling, the surface hardness of the hole is increased about 30%, and the fatigue strength of the cylinder inner surface is increased 25%. The cylinder service life is increased by 2 to 3 times if only the influence of cylinder barrel is considered, and the boring and rolling process is about 3 times more efficient than the grinding process. The above data shows that the rolling process is efficient and can greatly improve the surface quality of the cylinder barrel.

After the cylinder is rolled, there is no sharp tiny edge on the surface, and the long time movement friction will not damage the seal or seals, which is especially important in the hydraulic industry.

The Undesirable Consequences of Scratching the Surface of the Bore of a Hydraulic Cylinder

1. Scratch groove extruded material chip foam will be embedded in the seal, and may cause new scratch area trace path while damaging the working part of the seal during operation.
2. Deteriorate the surface roughness of the cylinder inner wall, increase the friction, easy to produce crawling phenomenon.
3. aggravate the internal leakage of the hydraulic cylinder, so that the hydraulic cylinder efficiency is reduced.