Measurement Case of Tubular Workpieces on Coordinate Measuring Machine
1. Workpiece to be Measured
The precision tubular workpiece measured in this case is mainly used in mechanical transmission systems. The dimensional accuracy and geometric tolerances of its inner bore and outer circle directly affect the assembly tightness and operational stability of the equipment, so full-featured, accurate inspection shall be completed using a coordinate measuring machine.
2. Probe Configuration
A Renishaw PH20 5-axis indexing touch probe with a TP20 stylus module is adopted, equipped with a slender ruby stylus. The infinite positioning function of the PH20 5-axis system allows flexible access to the inner bore of the tubular workpiece and avoids stylus interference. The TP20 module features high sensitivity, enabling accurate collection of point data for the inner bore and outer diameter. It balances measurement accuracy and efficiency, allowing full-feature inspection without frequent stylus changes.
3. Fixturing Tools
A universal fixture combination is used for clamping, which is compatible with various tube diameters. It prevents surface damage to the workpiece during clamping, ensures stability without displacement or deformation during measurement, and guarantees a unified measurement datum.
4. Coordinate Measuring Machine
A high-precision bridge-type coordinate measuring machine (CMM) with temperature compensation is selected. This function offsets the impact of ambient temperature variations in the workshop on measurement accuracy. The machine runs smoothly and, together with the PH20 probe, enables rapid point data acquisition for features such as the inner bore and outer diameter of tubular workpieces, meeting the requirements of batch inspection.
5. Software Operation Procedure
Import the CAD model of the tubular workpiece into the software, establish the workpiece coordinate system based on the end face and inner bore as datums, and run the corresponding measurement program. The probe collects data along the predefined path, while the software fits geometric elements and evaluates geometric tolerances in real time. Finally, a detailed inspection report including measured values and tolerance ranges is generated, facilitating quality traceability.
This solution, equipped with a coordinate measuring machine, enables efficient full-dimensional accuracy inspection of complex tubular castings, ensuring the workpieces meet design and assembly requirements.
