C-frame
C-frame systems have always been a proven concept for realising punching and joining applications.
The drive systems can be hydraulic, pneumatic, pneumohydraulic, toggle lever kinematic or servo-electric. BTM has been manufacturing its C-frames in a modular design for decades, so that an extensive portfolio of frame sizes, tool carriers and connection options has been built up.
Joining processes usually require high forces. The advantage of a C-frame compared to a press bridge or an X-frame (also known as a scissor tong) is its simple design. This means that only a few machine elements and assembly work are required, which makes this design much simpler and therefore more cost-effective. The good accessibility (installation clearance) for the product is another decisive advantage.
The disadvantage of C-brackets lies in the physically induced bending of this ‘C’ geometry. The associated coaxiality errors (angular misalignment) can cause problems in critical joining processes. For this reason, large C-brackets are designed as lightweight brackets in a special lattice construction, which are designed in such a way that they only work with spring deflection in the Z-axis if possible.
Nevertheless, especially for robot-guided applications, C-frames with large projections are mainly required, which are designed as lattice frames, e.g. with weight-optimised recesses. The BTM spider frames are better able to keep the acceleration and deceleration forces acting on the robot under control due to their lower mass.
For these reasons, BTM has been using simulation and calculation methods (e.g. finite element method/FEM) for decades. Our C-brackets have been developed and manufactured for many years with a view to strength and deflection behaviour. The modular design enables us to exchange and switch between different drive types on the bracket.
We offer the right drive solution in each case, depending on the joining force, cycle time, number of punching or clinching processes/year, stroke or the machine concept in general.
C-frame systems with the following drive solutions are particularly suitable for clinching:
- Electric servo spindle drives (NC axis)
- Double and single-acting hydraulic cylinders
- Hydraulic cylinders with energy-optimised units (e.g. servo inverters, speed-controlled hydraulic pumps, intermittent operation)
- Pneumo-hydraulic drives (pressure intensifiers)
