Report From JIMTOF

Following our own International Manufacturing Technology Show (IMTS) by less than 2 months, JIMTOF used to set itself apart by being the event at which many of the Japanese machine tool builders previewed the technological advances under development for future machine tool models. These prototypes or “concept machines” presented a glimpse of new directions in machine design.

This is less true today. Most of the new machines on display at JIMTOF had been shown at IMTS or another recent show. Those not shown elsewhere were typically developed specifically for the machine tool market in Japan. No doubt the Japanese machine tool builders are still investing heavily in research and development, but these projects were not emphasized at JIMTOF. Nevertheless, it’s significant that many of the main trends noted at IMTS were also apparent at the show in Japan.

The mood at JIMTOF, however, was somewhat tempered by concerns over the turmoil in the financial sector, a crisis that had already flared up before IMTS. Both exhibitors and attendees said they were quite busy with jobs and orders already on the books, but long-term prospects were suddenly rather shaky. At any rate, worries about the economy did not keep crowds away—more than 50,000 attendees passed through the gates on the peak day of the show.

Big machines for big parts were well represented. Wind turbine components, frames for construction equipment, engine casings for power generation and parts for large airliners are still in demand, and more machines are needed to produce them. Builders promoted the rigidity, high torque and thermal stability of these machines. Full five-axis capability was the norm rather than the exception.

Machine features designed to conserve energy were also getting attention. Some of the energy-saving provisions on display included gas-charged cylinders instead of hydraulic systems; axis motors with inverters that allow power regeneration; control systems that automatically turn off electrical devices (pumps, lights, motors) when not needed; and gear boxes in spindle drives that allow smaller motors than those used in direct-drive systems to achieve equivalent speed and torque.

Environmental safety was often bundled with energy efficiency as a key end-user benefit. For example, minimum quantity lubrication (MQL), a technique to deliver a fine mist of coolant precisely aimed at the cutting tool/workpiece interface, was promoted by many exhibitors as an “eco-friendly” practice. One booth showed a new toolholder that served as a self-contained MQL dispenser. It operates without connection to a machine’s built-in coolant delivery system.

Another common theme was machine tool automation. “Minimum operator involvement” was the goal for the same reasons it’s getting a lot of attention state-side: Good operators are hard to find, and it’s essential to maximize their contribution to the overall productivity of a machining system. Add-ons or accessories such as robotic part handlers are more likely to be included when new equipment is ordered by Japanese shop managers than not, several exhibitors said. Automation is not an option—it’s a must.

Interestingly, the need for automation is reaching deep into machine design and machining strategy. For example, an HMC from one builder is designed to move the spindle, rather than the worktable, in three axes. This configuration keeps the workpiece still so that it is simpler for a gantry loader/unloader or robotic arm to find it. Likewise, shifting prismatic work to turn-mill machines with bar feeders to take advantage of built-in workhandling/fixturing automation is a popular strategy among shops in Japan.

A remarkable number of machines from Japan claim accuracy to ±1 micron or less. Some builders stress that relying on traditional means of achieving such accuracy is a foundation upon which other strategies rest. Thus, they insist on hand-scraping ways and other critical surfaces. Another major focus is on controlling heat effectively. For example, thermally symmetrical machine structures help avoid distortions that occur when heat spreads unevenly. Isolating sources of heat from the rest of the machine is another design consideration. Removing heat that does get through by circulating chilled coolant is another option, as is compensating for its effects electronically by responding to sensor feedback.

A glance at the many cutting tool suppliers at JIMTOF finds small tools proliferating. One company showed a 0.01-mm-diameter end mill as a standard item, not as a special, indicating that prices are going down and availability is going up. Another company showed a 0.5-mm drill with a coolant hole in the center for work on diesel engine injection nozzles.