Machine Tool Worktable Castings

Support custom orders with images

Machine tool worktable castings are the core functional components that directly carry workpieces and achieve feed motion. Their performance and accuracy directly affect the quality of processed workpieces and occupy a key position in various types of machine tools. This type of casting requires a balance between high strength, wear resistance, and dimensional stability. Common materials include gray cast iron (HT250, HT300), ductile iron (QT500-7, QT600-3), and some heavy-duty machine tool workbenches use cast steel (ZG270-500) to meet different load and precision requirements.

From the perspective of performance requirements, worktable castings need to have three core characteristics: first, sufficient rigidity to withstand the weight and cutting force of the workpiece without significant deformation. For example, the maximum deflection of a horizontal milling machine worktable carrying 5 tons of workpiece needs to be controlled within 0.02mm/m; Secondly, it has excellent wear resistance. After quenching or nitriding treatment, the hardness of the tabletop needs to reach HB200-250 to resist friction loss during workpiece loading and unloading and processing, and extend its service life; The third is high-precision guidance. The straightness error of the table guide rail is ≤ 0.015mm/1000mm, and the parallelism error is ≤ 0.02mm, ensuring the smoothness of the feed motion.

In terms of manufacturing technology, worktable castings are often made using sand casting or lost foam casting. Sand casting ensures cavity accuracy through resin sand molding, making it suitable for mass production; Lost foam casting can form complex structures such as T-shaped grooves and positioning holes on the table as a whole, reducing the amount of subsequent processing. After casting, it needs to undergo aging treatment (natural aging for 6 months or artificial aging at 200 ℃ × 24h) to eliminate casting stress and avoid deformation during use. In the mechanical processing stage, the table needs to undergo rough milling, precision milling, grinding and other processes to achieve a surface roughness of Ra1.6-3.2 μ m, and the flatness error of key positioning surfaces should be controlled within 0.03mm/m.

The quality control process is particularly strict. Castings must undergo magnetic particle inspection to detect surface cracks, and there must be no air holes or shrinkage porosity with a diameter of ≥ 3mm inside. For the worktable of the CNC machining center, dynamic balance testing is also required, with an amplitude of ≤ 0.005mm at the highest feed rate to ensure stability during high-speed motion. In addition, the groove spacing tolerance of the T-shaped groove on the table should be controlled within ± 0.03mm to ensure the positioning accuracy of the workpiece clamping.

In application scenarios, the worktable castings of different types of machine tools have their own characteristics: the horizontal lathe worktable emphasizes rotation accuracy, and the perpendicularity error of the end face to the axis is ≤ 0.01mm/100mm; The milling machine worktable emphasizes feed stability, and the guide rail clearance needs to be adjusted to 0.01-0.03mm; while the coordinate boring machine worktable pursues ultimate positioning accuracy, and its tabletop coordinate error can be controlled within ± 0.005mm. These characteristics make worktable castings a "benchmark platform" for precision machining of machine tools, and an important indicator for measuring machine tool performance.