Modern Machine Shop
Sunnen’s all-electric HTA hone is designed to increase part capacity and stroker torque in applications such as bore resurfacing of hydraulic cylinders, extruder barrels and die casting shot tubes, manufacture of gas flow meter tubes, and repair of actuators for construction, mining, farming and forestry equipment.
The machine is available in two standard model sizes, one for 6.9-ft. (2.1-m) part lengths and one for 13.5-ft. (4.1-m) part lengths, accommodating true 2- or 4-m parts. Both models accommodate parts with bore IDs ranging from 2.5" to 21" (63.5 to 533 mm), maximum part OD measuring 24" (610 mm), and parts weighing as much as 8,000 lbs (3,628.7 kg). The machine also can be custom-configured for part lengths ranging to 65.6 ft. (20 m), or with a powered section only for unhindered part lengths. A stroker drive gearbox increases stroker torque capability by 35 percent over the previous HTA model, the company says. Width of the steel-impregnated polyurethane belt has been increased from 0.9" to 1.9" (22 to 50 mm).
The hone maybe used for resurfacing and repair work where light-duty stock removal up to 0.030" (0.76 mm) is needed to oversize deeply scratched bores. An electronically controlled, 3-hp (2.24-kW) AC gear motor powers the spindle at 20 to 300 rpm, while the servo-driven stroking system has a speed range of 5 to 90 ft./min. (1.52 to 27.4 m/min.). The all-electric machine eliminates the noise, leaks, valve adjustments and performance variability inherent to hydraulic systems, the company says.
The machine has a 55-gallon (208-L) coolant reservoir and paper-media coolant filtration unit for better coolant management. Set on casters for ease of maintenance, the coolant tank tucks under the machine frame to conserve floor space.
The system includes Siemens drives and PLC control with touchscreen HMI for setting all machine parameters, including stroke reversal point, spindle/stroking speeds and crosshatch angle calculation. The control features a digital load meter to determine areas of bore tightness, with capability for dwelling the tool in multiple areas to correct part geometry. It also has automatic tool tensioning, set through the PLC.