Component cleaning for metalworking in the tightest of spaces - Robotic tool change in the wet cell

Production solutions & processes

The systems and technologies supplied by Silberhorn form an essential part of the manufacturing process for any company that machines components, by removing burrs, oil, and grease and other contaminants. Although the company manufactures a wide range of standard cleaning solutions, many of the systems developed by Silberhorn are bespoke and tailored to meet the specific requirements of the individual customer and application. Following a detailed initial analysis and clarification of requirements Silberhorn will recommend the most appropriate process solution. Depending upon the application, the system configuration can differ, and operating pressures can vary greatly, with pressures often ranging from 100 bar up to 1800 bar. 

The challenge

Processing multiple part types within an arduous environment

A customer which machined both steel and aluminium parts required a system capable of  cleaning both materials equally well, which in itself is relatively unusual and a particular challenge. In addition, the customer required that the system was highly flexible in terms of dealing with the range of parts to be cleaned. This meant that the system would need to be designed in such a way that different parts could be cleaned without requiring major reconfiguration or set up when changing from one part type to the next.

Initially, the system would be required to process three component types. However, the customer required that the system should be flexible enough to accept a range of other component types at any time in the future. The steel parts initially identified to be cleaned weigh a maximum of around 7 kg, whilst the aluminium parts were somewhat heavier at a maximum of around 10 kg. The largest part was approximately 800 mm long and 600 mm wide.

The solution

Stäubli automatic tool changers provide a reliable and flexible solution

The solution identified by Silberhorn for this particular application comprised of a combination of robots and a continuous cleaning system. This system also was somewhat unique in the way in which it operated. Rather than gripping the component and presenting it to various cleaning units, as is usually the case, in this system the two robots within the cell hold and manipulate different cleaning instruments to process the components as they pass through the system. 

This is made possible through the use of special Stäubli tool changers giving the robots additional flexibility and allowing the customer to select between 5 cleaning tools per robot. The first robot in the system currently uses a single, permanently fixed tool. The second robot always has access to two different tools during its cycle. When the robot is not using the cleaning tools, they are stored above the robot. This ensures that minimum levels of contamination collect on the tools.

The arduous environment within which the tool changers would operate required an innovative approach for the Stäubli tool changers, including the selection of different materials and special coatings. As there are no electronic sensors in the wet area, the system recognises whether the robot is using a tool and if so, which one, via a pressure line. If there is no pressure, a pneumatic module signals "there is no tool on the changer" to an external pressure sensor. If pressure is present, the system can even recognise which of the various tools is currently in use by means of the difference in pressure.

The result 

A successful solution achieved with Stäubli cooperation and support

In the initial stages of this project Stäubli visited Silberhorn bringing samples of the automatic tool changer to open the discussions and demonstrated how the tool changer system operates. During the design phase, Stäubli worked closely with Silberhorn to identify and resolve the specific technical challenges associated with the application and the arduous operating environment. The result is a robust system which meets both the process and flexibility requirements of the end customer.