The granite base is the core support and precision reference of the 2D imaging system, directly determining the equipment’s long-term stability, measurement accuracy, and environmental adaptability, serving as the “foundation” of precision measurement.
Гранитное основание
I. Core Role: Why Granite Must Be Used
Ultra-high Rigidity Extremely Low Deformation: 00-grade natural granite (such as Jinan Green) has high density and hardness (Shore hardness Hs70 ), strong compressive strength, and remains undeformed over the long term. It eliminates the aging deformation of cast iron/steel, ensuring an annual precision drift of ≤0.5μm.
Excellent Thermal Stability: It has an extremely low coefficient of linear expansion, with minimal thermal expansion and contraction during temperature fluctuations. In a standard workshop environment without strict constant temperature control, it can still stably maintain micron-level precision.
Strong Vibration Resistance and Absorption: Natural stone has good damping properties, effectively absorbing ground and operational vibrations to avoid imaging jitter and positioning deviations, making it particularly suitable for mass inspection scenarios.
Superior Flatness and Wear Resistance: The base/worktable is precision-ground to achieve 00-grade flatness. The surface is hard and scratch-resistant, maintaining the reference surface precision over long-term use, ensuring stable loading and clamping.
Corrosion Resistance and Long Lifespan: Resistant to acids and alkalis and rust-proof, it adapts to workshop environments with oil and dust. It has low maintenance costs and a service life far exceeding that of metal structures.
II. Structural Application: How the Base Supports the Entire Machine
Base (Main Machine Base): Supports the columns, worktable, guide rails, and transmission system, ensuring the perpendicularity and parallelism of the X/Y axis motion reference and suppressing overall machine deformation.
Columns / Beams: Integrated with or rigidly connected to the base, they support the CCD lens and Z-axis mechanism, eliminating cantilever sag and ensuring the perpendicularity of the Z-axis to the worktable.
Worktable: A double-layer granite structure that supports workpieces and optical glass, ensuring the leveling accuracy of the X/Y axes and avoiding local deformation caused by the workpiece’s own weight.
III. Precision Assurance: Key Value to Measurement
Basic Precision: Combined with grating scales (1μm resolution) and servo systems, it achieves a three-axis accuracy of ±1.5μm and a repeatability of ≤1μm.
Long-term Stability: Overcomes the “creep” problem of metal materials, ensuring that precision does not degrade over long-term use, making it suitable for high-precision mass inspection in molds, electronics, and hardware.
Environmental Adaptability: In workshop environments with temperature fluctuations and slight vibrations, it still stably outputs high-precision data, reducing the stringent requirements for the installation environment.
IV. Common Materials and Selection
Jinan Green (Most Common): High density, high hardness, good thermal stability, and high cost-performance, suitable for most standard machine models.
Indian Black / Zhangqiu Black: Higher precision and stronger stability, used for high-end/large-stroke machine models (such as gantry types).
Grade Requirements: 00-grade (the highest precision grade) must be selected, with flatness, parallelism, and perpendicularity strictly meeting standards.
V. Industry Application Scenarios
Precision Molds: Inspecting the dimensions and form/position tolerances of cavities, cores, and guide pillar holes to ensure mold consistency.
Electronic Components: 2D dimension and contour inspection of tiny parts such as mobile phone middle frames, camera modules, and connectors.
Precision Hardware / Stamped Parts: Position, concentricity, and straightness inspection of springs, screws, gears, etc.
Plastic Parts: Non-contact high-precision measurement of burrs, hole diameters, and spacing of injection-molded parts.
