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Multi-Axis Robots Bring Significant Advantages in Production of Diesel Injector Valves

Stäubli Robotics

Multi-Axis Robots Bring Significant Advantages in Production of Diesel Injector Valves

The incorporation of multi-axis robots into the machine shop has tended to lag behind the investment in new machine tools. However the use of high precision industrial robots integrated alongside modern machine tools can offer significant benefits measured in reduced cycle times, lower floor space requirements and improvements in component quality that can transform the overall production efficiency of many machined parts.

One application where the use of multi-axis robots has brought significant advantages is in the production of diesel injector valves at Delphi Diesel Systems.

Douglas Curtis Machine Tools of Colchester were recently commissioned by Delphi to improve the production rates for these components at both the UK factory in Sudbury as well as at La Rochelle in France. The required operation was to extract part machined components from the input pallet, precision gauge (to sub-micron levels) including the option for SPC sampling, present to the 'Supfina' face grinding machine, unload, deburr and re-palletise all within the grinding cycle time. Not only was this achieved, the robots performance exceeded expectations. As Michael Scarfe the Project Manager at DCMT commented ' The robot operating speed had to be restricted to avoid extended dwell times during the cycle. The critical operation defining the overall production rate is now the actual grinding process.'

When confronted with this challenge Scarfe's initial reaction was to consider adapting the pick & place automation systems which they currently supply to Delphi. However, contact with Stäubli Robots Engineering and Application Support staff prompted the option of multi-axis robots to also be evaluated. The established view at DCMT was that these were too simple and straightforward tasks for the sophisticated abilities of the precision industrial robot and that the expenditure would be difficult to justify. In reality the use of Stäubli RX robots provided a less complex solution, requiring only 50% of the floor space of the pick & place system, coupled with improvements in cycles times, quality levels, repeatability and reliability that were just not achievable with any other system. The robot can also readily incorporate changes in the operational sequence in response to design changes and product developments at Delphi. All of these benefits and the systems were delivered at a lower overall cost!

DCMT selected the Stäubli RX60 robot for use in the Delphi application. To date three systems have been supplied, two into the UK factory followed in June 2000 with one to France.

Stäubli RX robots feature high speed and acceleration and are capable of following complex trajectories even at high speeds. Joint speed ranges up to 1125degrees per second. The high degree of accuracy and repeatability make the RX ideal for the performance of detailed, meticulous tasks. At the heart of each RX robot is the patented, unique, JCS gearbox providing zero backlash and consistent performance. In essence the embodiment of Swiss precision and reliability. They are compact having a minimal footprint and are suitable for floor, wall or ceiling mounting. The range includes models with load capacities from 1.5kg to 60kg with a reach at the wrist from 665mm to 2135mm.  The movement in 6 axes provides an extremely large work envelope. User friendly software permits easy programming as well as re-programming to bring the added degree of flexibility often of benefit in automated systems.

This successful experience with integrating Stäubli robots into the machine shop environment has changed the approach to automation now being taken at DCMT on a number of new projects. Multi-axis robots are now the first option that is considered. A system for grinding the edge on commercial vehicle wing mirrors has just been designed, built around a Stäubli RX90 robot. The development of a new process for the production of bearings for roller conveyors uses a loading/unloading system based on the Stäubli RX60 robot in place of the traditional pick & place option. In both cases the facility to modify and adjust the precise operation of the robot brings significant advantages particularly where process parameters and production methods are continually being reviewed.

Douglas Curtis Machine Tools started out in 1973 and have specialised in providing the machine tool user with special purpose machines mainly in the automation and test equipment application areas. In most cases these are tailored to specific customer requirements. A wide range of expertise and facilities are available in-house from initial project analysis and design through to manufacture, installation and commissioning. The success of the business is illustrated by the 20/25% p.a. growth achieved in recent years.

Working in association with Stäubli, the experts in multi-axis precision industrial robots has opened a wider field of applications to DCMT where the flexibility, accuracy and repeatability of RX robots are increasingly being appreciated by the end user. It is only through the increasing willingness of businesses like DCMT to fully evaluate the feasibility of using multi-axis robots and the quality of support available from Stäubli, that the UK's relatively poor performance on the integration of robots into manufacturing applications will be improved.

Stäubli Unimation is an international family owned group founded over 100 years ago in Switzerland employing 2400 world-wide. Robotic production is centred south of Geneva in the French Alps, with facilities across Europe, North and South America and the Far East, the UK base is in Telford.


For additional information, please contact
Marketing Manager
Stäubli Corporation - Robotics Division
201 Parkway West
Duncan, SC 29334
USA
Tel. 864-433-1980
Fax. 864-486-5497
robot.usa@staubli.com

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