Schmidt servo presses deliver precision control, with forces ranging from 15kN to 250kN, and are capable of delivering high rates of acceleration and deceleration, with a positional resolution of less than 0.1 micron over ram strokes up to 500mm. In addition, Schmidt presses integrate powerful drive units with intelligent process feedback technology and highly responsive controls that deliver true closed-loop control for precise, predictable and repeatable results.
In practice, this translates into consistent load across the full ram stroke, plus the ability to adjust automatically for factors such as elasticity in the parts being handled, with virtually instant response, to changing pressure or force values. Additionally, the speed with which the ram reacts to the specified force, acceleration or dwell timing parameters is both exceptionally quick and repeatable - which is the key factor in high-volume production applications.
The latest Schmidt 5000 Press Control unit adds the capability for intuitive setup and simple operation, as well as real-time graphical and numerical analyses of process conditions. It also benefits from an interface with remote control systems for trend analysis, interaction with factory automation networks and offline programming.
These servo press systems are being used by many different customers around the world. For example, Schmidt 460 servo presses with 4000 control systems are being used by the UK division of Airbus Industries to boost productivity by over 50 per cent in the manufacture of wing stringer sections for the Airbus A320 and A380, while enhancing the control that production engineers have over what is a complex stage in the production of safety critical airframe components.
The presses use specially developed swivelling tooling to shape the wing stringers, using multiple bends to create a unique series of profiles that are precise to within several microns over their entire length. Additionally, the Press Control system is linked via Ethernet to allow all process parameters to be monitored and analysed as part of ongoing quality improvement programmes.
A similar custom-built servo press system is being used by Millipore to cut downtime on its membrane filter cutting lines at its facility in Ireland. The presses are also enabling the company to minimise scrap by optimising the number of elements produced from each roll of filter media, with the combined result that machine payback has been achieved in around nine months.
The presses use dedicated tooling, customised robotic loading and unloading stations, and machine safety and guarding systems. Schmidt Technology also provided programming expertise for the dedicated press controls. The presses cut individual filter discs for medical applications from rolls of specialised media, with extremely high levels of accuracy and repeatability, within +/-0.1mm. These presses handle a variety of media measuring between 150 and 320mm in width.
Pin insertion and inspection
A growing area of interest is compliant pin assembly and inspection, and Schmidt has developed special tooling to complement its servo presses for use in press-fit applications such as PCB assembly. These systems offer a simple and fast method of assembling circuit boards to connector pins using rotary index systems that are capable of producing up to 600 pieces per hour. The systems can also be configured to detect the presence of each pin prior to the press cycle, using laser sensors, continuity checks, cameras and barcode readers, and to offer post-press inspection to check that all pins are at an even height relative to each other.
Schmidt servo press systems are modular in design, use proven technology and, with the dedicated support of the company's UK custom build facility, offer both OEMs and end users an extensive range of options in many different applications. In each case, Schmidt presses can play an important role in enhancing product quality, improving process performance and increasing productivity.
In the UK, Schmidt Technology has a specialised operation for sales of standard servo-controlled presses and the development and production of custom-built automation systems.