Rolled pipe technology: precision processing technology for high-precision hydraulic cylinder barrels
Rolling pipe is a high-precision machining process for hydraulic cylinder barrels. The rolling tool continuously plastically deforms the inner hole surface to obtain ideal smoothness and geometric accuracy. Compared with traditional honing and boring processes, rolling processing has significant advantages such as high processing efficiency, good surface quality, and deep material hardening layer. It is widely used in the fields of hydraulic cylinder barrels, cylinder barrels, and precision machinery manufacturing.
The core principle of rolling processing is to use the rolling head to adhere to the inner hole wall of the workpiece under pressure, and through the rolling rolling of rollers or balls, plastic flow occurs on the metal surface, thereby eliminating microscopic peaks and valleys, reducing surface roughness, and forming a favorable residual compressive stress layer. This hardened layer can effectively improve the wear resistance and fatigue strength of the workpiece surface and extend its service life. The rolling process is especially suitable for cylinder parts with thin wall thickness, and can significantly improve the surface properties without changing the size of the workpiece.
From an equipment perspective, rolling pipe processing requires the use of special inner hole rolling tools, and the appropriate rolling force, rolling speed and feed amount are selected according to the workpiece material and processing requirements. Common types of rolling heads include single roller type, multi-roller type, and hydraulic automatic retreat type. The hydraulic automatic retreat rolling head can maintain a constant rolling force in mass processing and effectively avoid over-rolling problems caused by differences in workpiece wall thickness. It is currently the most widely used form.
In actual production, the quality control of rolled pipes involves multiple key indicators. The first is surface roughness. The surface roughness Ra value of the inner hole after rolling can usually reach 0.1-0.4μm, which is far better than ordinary boring and honing processes. Second is geometric accuracy, including roundness, cylindricity and wall thickness uniformity. In addition, attention should be paid to the depth and hardness distribution of the surface hardened layer, as well as whether there are hidden defects such as micro-cracks. In order to ensure the stability of rolling quality, strict material inspection and dimensional pre-processing of pipe materials are required before processing, and necessary cleaning and anti-rust treatment are required after processing.