Sunnen SV-30 cylinder hone offers automatic step and repeat capability

2 mins read

The latest Sunnen SV-30 honing series is the company’s next generation of Cylinder King machines. Aimed at engine cylinder blocks, cylinder liners and other engine parts that require honing, six standard models, including four step-and-repeat capability versions, allow automatic bore-to-bore processing for in-line and V-block configurations. In addition, two models are available with a manual X axis. The SV-30’s cylinder diameter range is 19 to 200 mm depending on the tooling option. Sunnen’s GH-LF tooling is required for automatic step-and- repeat operations.

SV-30 machines include a PC control with simplified menus and storage for more than 1,000 set-ups. The SV-30 also features spindle reversal, standard bore oversize set-up and automatic tool protection at the top and bottom of the bore, which verifies an unobstructed stroke before starting a cycle. Models include either a variable speed 4.5 kW servo or 4.1 kW induction spindle motor, producing speeds from 50-600 rpm. A 2.5 kW servo ballscrew system produces up to 100 true vertical strokes per minute, with a stroke travel of up to 705 mm. The linear stroking drive maintains concentricity with the bore throughout the full stroke to produce a consistent diameter from top to bottom. A 1,219 by 760 mm work envelope allows versatility in processing larger parts.

The newly developed spindle reversal feature duplicates the capabilities of machines used by automotive OEMs. "Reversal can be used anytime in the process, but is especially helpful during finishing strokes," says Phil Hanna, Sunnen product manager. "Reversal helps to create a slightly rounder bore and aids in achieving the desired surface finish. It causes the honing stones to take out any less-than-round shape left after the initial passes, while shaping up and dressing the stones themselves. Reversing the spindle also helps in removing folded-over metal and cleaning debris from the valleys of the surface finish."

A Phoenix industrial PC control ensures automatic, consistent bore-to-bore geometry and finish, without constant adjustment by the operator. The 15” colour touchscreen with intuitive controls provides a real-time display of the full-bore cross section during the process. A programmable auto-dwell feature automatically corrects taper anywhere in the bore for unattended operation, while two-stage honing tools with diamond or CBN abrasives can complete roughing and finishing operations in a single pass.

Left/right positioning of the honing column on its 813 mm X axis is accomplished with a servomotor or manual hand wheel located immediately below the operator station (model dependent). The machine is equipped with a 208 litre internal coolant system featuring two standard steel canister cartridge filters, a heavy-duty pump and filter status gauge.

In addition to the GH-LF tooling (required for automatic step and repeat operations), the SV-30 is compatible with all of Sunnen's current large diameter tooling, including diamond abrasive hone heads and brushes, GHSS single-stage hone heads with CBN or diamond abrasives and brushes, and GHTS hone heads for two-stage honing with CBN or diamond abrasives.

The SV-30 is equipped with LED lighting in the work envelope and has the latest safety features, including light curtain, interlocked front door, stainless guarding around the work envelope, and safety PLC, which limits set-up speeds in all axes. Options include a T-slot base (for bespoke fixtures), heavy-duty manual rollover cradle for engine blocks, and a full-feature automation interface.