Automation clamps for machining and small batches

Clamping technology is changing noticeably in metalworking. Series are becoming smaller, components are changing more frequently and at the same time the pressure is increasing to run machines for longer and with as little manpower as possible.

In machining in particular, it is therefore not only the machine itself that determines productivity, but also the question of how workpieces are clamped, transferred and processed automatically.

Gressel large stroke clamps for flexible components

Gressel is showcasing a new hydraulic large-stroke clamp that is specially designed for automated production processes. At 230 bar, the system achieves a total clamping force of 80 kilonewtons and a stroke of 110 millimetres. This combination is particularly relevant when different components need to be covered with one clamping device. The large stroke makes it possible to accommodate several workpiece sizes within one clamping range. At the same time, the height ensures good accessibility on 5-axis machines. This is a key point in metal cutting, as workpieces need to be machined as freely as possible without clamping devices unnecessarily restricting the tool path. The clamp can be used in a variety of sectors - from the automotive industry to contract manufacturers and series production. The decisive factor is the ability to reliably position changing components.

Displacement sensor instead of control via oil quantity

One technical detail is the integrated displacement sensor. It enables the jaw position to be precisely recorded and pre-set via software. This distinguishes the system from solutions that work via the flow rate of the hydraulic oil. This accuracy is important for automated processes. The system must know where the clamping jaws are located and which component is being clamped. This is the only way to reliably process different workpieces without manual intervention.

Electric clamp with 120 millimetre stroke

In addition to the hydraulic large-stroke clamp, Gressel is also presenting an electric clamp. This works completely electrically, achieves a stroke of 120 millimetres and also achieves a total clamping force of 80 kilonewtons. The clamping force is distributed over 40 kilonewtons per side. The design is modular. By changing the spindle, different lengths can be realised while the stroke remains the same. The motor and electronics are integrated into the carriage and the power is supplied from below. This makes the electric clamp particularly suitable for applications where electrical control and flexible integration are required.

R-C2 module for robots and mechanical vice

Another focus is on automated workpiece handling. The R-C2 module is used on the robot and controls a mechanical vice. The vice performs several tasks simultaneously: it grips the workpiece, clamps it and also serves as a pallet. The process is designed for unmanned operation. The component is picked up at a transfer station, placed in the machine on a zero-point system and processed there. After machining from five sides, it is transferred to a second vice, returned to the machine and finished. The main advantages lie in the process chain:

• Workpiece pick-up directly from the tray
• Gripping and clamping with the same vice
• Machining of multiple sides without manual reclamping
• Use for small batches and recurring individual parts
• Low-manpower operation over longer running times

Automation with a shortage of skilled labour and small batch sizes

The importance of such solutions is a result of developments in manufacturing. Many companies no longer work with long, uniform series. Instead, different parts have to be produced in small quantities. At the same time, there is a shortage of skilled labour to carry out simple insertion and reclamping tasks. With automated clamping technology, a system can process several different components at night, while individual parts or more demanding tasks run on the same machine during the day. This does not replace the skilled worker, but relieves them of routine tasks.

Cleaning as part of the automated process

Cleaning is a point that is often underestimated. Chips and coolant must remain in the machine wherever possible. This is why the workpiece should already be cleaned inside the machining area - for example with blow nozzles, propeller solutions, air curtains or an additional blow box.

For Gressel, this step is part of automation. The process only remains stable if workpieces are transferred cleanly. Clamping technology, robot handling and cleaning therefore belong together if automated machining is to function reliably.