Established an integrated production system for spindles
As a basic component of machine tools, there is strong demand for high-precision spindles during machining and assembly. At the Iga Campus, we built a specialist spindle plant in August 2006 to start a new production system. Spindle production used to be done at two factories, the High-Precision Facility and the Assembly Plant, but during summer and winter, when the temperature difference between the inside and the outside of the factories was large, there was a possibility that the accuracy could be affected when the spindle components were carried from the High-Precision Facility to the Assembly Plant. For this reason, we changed the High-Precision Facility, where the temperature is controlled, into the Spindle Plant, to do everything from parts machining to assembly to inspection. This enabled us to maintain the high accuracy of our parts throughout the whole machining process. Also, spindle units are assembled in the clean room, in which temperature, humidity, dust are strictly controlled. During the final process, all spindles are checked using the spindle running table, just as we do when performing a shipping inspection. At the same time, we conduct break-in operation to find any abnormalities at an early stage. By making efforts like this, we are planning to raise our monthly production capacity by approx. 30% from 850 to 1,100 units in FY 2007.
In-house production of ball screws which support DCG®
DCG® (Driven at the Center of Gravity) represents Mori Seiki's original technologies. The core of this technology is the twin drive structure which uses two ball screws for its feed axes. In order to commercialize the twin drive, high standards are required for ball screws, such as quality, cost performance and delivery times, but Mori Seiki has satisfied all these criteria by producing our ball screws in-house. We conduct integrated production by using the Kanban method for everything from cutting regular size material, high-frequency induction hardening, and grinding, to assembly of ball screws, completing standard parts in 7 working days. We also conduct lead accuracy measurements and quality assurance on all units. We currently produce approximately 2,400 ball screws per month, which is enough for about 80% of all Mori Seiki machines shipped. At the same time as establishing this Spindle Plant, we also built a specialist Ball Screw Plant. In future, we will continue to strengthen equipment such as male thread grinding machines, etc, to raise our production capacity.
The Casting and Sheet Metal Plants start operation one after the other
We built the Sheet Metal Plant in August 2006 and the Casting Plant in October the same year, and they have both started full operation. The Sheet Metal Plant, with its increased equipment, has a processing capacity 5.5 times larger than before, and a coating capacity 7.7 times larger. It operates 24 hours a day, and processes which used to take 1 week have been shortened to 3 days. On the other hand, the Casting Plant, which was built with the purpose of reducing the time for developing test machines, is equipped with a 5-ton melting furnace, offering monthly production capacity of 200 tons. Delivery of castings used to be a bottleneck which prevented the development period for test machines from being shortened. However, Mori Seiki's Casting Plant uses the full mold method to reduce delivery times. This uses styrofoam molds instead of wooden patterns, and is ideal for manufacturing of test pieces or single items. The wooden molding process reduces casting processes which used to take 1.5 months to 2 weeks, and is also environmentally friendly since it collects dust, etc.