Sunnen has added to its tube honing line with the HTD, which features a 16-m (52-ft) stroke and handles parts with bore diameters up to 1000 mm (39 in). An electronically controlled, 30-kW (40.23 hp) spindle motor powers stock removal of 2500 cm³/h (150 in³/h). The machine is designed to correct bore geometry and size errors, as well as produce specific surface finishes and crosshatch angles to ensure correct sliding/sealing surfaces between mating parts.
The HTD, which Sunnen says is the longest and most powerful in its line of six tube hone machines, uses a Microsoft Windows-based controller for optimum control of bore geometry with functions for stroke position, motion, stone feed, and cutting pressure. The HTD—applicable for honing applications that include helicopter and marine driveshafts, submarine periscopes, bi-metallic tubes, and hydraulic cylinders—is particularly suited for controlling taper variation and drift in long bores via the use of Sunnen's double- and triple-banked tools, which are said to have up to triple the abrasive length of ordinary tools. Available abrasives include aluminum oxide, silicon carbide, CBN, and diamond honing stones.
Capabilities of Sunnen's tube hone lineup range from light-duty repair and resurfacing work to high-power, high-metal-removal applications on long, large parts. The family of machines can handle bore diameters from 3 to 1000 mm (0.12 to 39 in), with stroke lengths starting at 2 m (6.6 ft). Stock removal rates range from 130 to 2500 cm³/h (8 to 150 in³/h).
In terms of other machines in the lineup, the HTA is an all-electric system for light-duty surfacing applications for flow meter tubes and hydraulic cylinder repair. The HTA is available in 2- or 4-m (6.5- or 13.1-ft) stroke lengths. Both configurations handle parts weighing up to 1815 kg (4000 lb). The HTA is able to mount ANR275-type tooling and is available for bore inner diameters of 63.5 to 533 mm (2.5 to 21 in) and maximum outer diameters of 610 mm (24.0 in).
For hydraulic cylinders, gun barrels, precision tubing, and other small-diameter, long-part applications, the CNC-controlled HTC tube hone provides bore finishing solutions for diameters from 4.1 to 50 mm (0.16 to 2 in) and bore lengths up to 2760 mm (109 in). The HTC uses a variety of honing tools including MMT multistone mandrels, which provide enhanced speed and accuracy for decreased cycle times and lower cost per part.
All HT series machines are operated electromechanically for more precise control of the stroke, without the heat, noise, and fluid leakage of hydraulic machines, says Sunnen. Automation options for enhanced productivity include robotic integration for automated loading/unloading of parts.