This volume explains the large equipment design of automation devices using the improved technology.

(1)Required performance for the large XY table

・Since many high-precision XY tables are commercially available as standard items, they can be referred to as an established technology in terms of the production technology.In this case example, the following requirements are added to the commercially available items in order to realize the high-speed driving and high-precision machining on a large-sized unit (long stroke):

* Large yet lightweight movable body is supported
* Made of materials that are insensitive to the long-term environmental fluctuation (such as temperature changes and vibration)
* Materials and structure are suitable for high-precision machining

・To meet these requirements, we developed our own model using granite stones, instead of adopting a commercially available XY table made of steel-based materials.

(2)Vital points in designing large XY table

The designer of the large automation device should consider design processes by acknowledging the following points.

<Vital points in designing large equipment>

1. It is important to select a structural material that is insensitive to thermal displacement and vibration while the deterioration with age is minimal.
   Description: Granite stones are those used in the surface plate of precision measuring equipment (Fig.1) and have the characteristics listed in (1).
2. Highly rigid structure (minimum deflection by the self-weight) --- See the next volume for details.
3. Structural design allowing effortless precision adjustment during assembly
   Description: After fine-polishing the granite stone, adjust the flatness, perpendicularity and parallelism by ultra-precision machining.
   Fig.2 illustrates the sectional shape accuracy of 1.4m-long linear guide rails. The parallelism of the bottom reference plane against the top side is 0.003; the parallelism of the side reference plane against the lateral face of the rail is 0.008.
4. Selecting inexpensive standard components that are compatible with large equipment design