Sunnen's new HTD tube hone goes to great lengths—and diameters—to deliver a 16-m stroke while handling parts of diameters up to 1000 mm. An electronically controlled, 30-kW spindle motor enables a stock-removal rate of 2500 cm3/h for fast honing of aircraft driveshafts, marine driveshafts, and similar components.
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 longest, most powerful in the six-machine line of Sunnen tube hones, the HTD uses an operator-friendly Windows-based controller for optimum control of bore geometry with functions for stroke position, motion, stone feed, and cutting pressure. It is particularly suited for controlling taper variation and drift in long bores using Sunnen's double- and triple-banked tools, which have up to triple the abrasive length of ordinary tools, according to the company. Available abrasives include aluminum oxide, silicon carbide, CBN, and diamond honing stones.
Sunnen is the world's largest producer of tube hones, having supplied nearly 500 machines built at plants in the U.S., Europe, and Asia. The company says its six tube-hone models can do everything from light-duty repair and resurfacing work to high-power, high-metal-removal applications on long, large parts. These machines handle bore diameters from 3 to 1000 mm, with stroke lengths of 2 to 14.5 m, providing stock removal rates of 130 to 2500 cm/h.
The HTA is an all-electric system for light-duty surfacing applications for flowmeter tubes and hydraulic cylinder repair, providing stock removal in the range of 0.76 mm. The HTA is available in 2- or 4-m stroke lengths; both configurations handle parts weighing up to 1815 kg. The HTA is able to mount ANR275-type tooling and is available for bore inside diameters of 63.5 to 533 mm and maximum part outside diameter of 610 mm.
The versatility of the model HTB makes it a good fit for job shops, according to Sunnen. It combines important capabilities, such as short stroke cycle and stroke dwell for blind holes, with a built-in load meter to indicate high and low spots; this allows operators to adjust the stroke for optimum cycle time. Available in 2-, 4-, 6-, and 8-m models, the HTB has a stroke range of 2000 to 8000 mm. It handles part diameters up to 600 mm and is suitable for sizing and finishing bores with inside diameters of 25 to 572 mm. The HTB's 3-W spindle removes stock at a rate of 400 cm3/h.
The HTH series adds a 10-m model to the sizes offered by the HTB series and uses the same control and tool feed system. A 6-W spindle removes 800 cm3 of material per hour. It has a maximum stroke length of up to 10 m and handles bore diameters from 25 to 1000 mm.
For hydraulic cylinders and similar small-diameter, large-part applications, the CNC-controlled HTC tube hone provides bore finishing solutions for diameters from 4.1 to 50 mm and bore lengths up to 2760 mm. The HTC uses a variety of honing tools including MMT multistone mandrels, which provide superior speed and accuracy for decreased cycle times and lower cost per part.
All HT series machines are operated electromechanically, providing more precise control of the stroke, without the heat, noise, and fluid leakage of hydraulic machines. Automation options for enhanced productivity include robotic integration for automated loading/unloading of parts.
Sunnen builds tube hones in the U.S., Switzerland, and China and has more than 400 machines installed globally.