Reducing the cycle time with FASTpress when assembling cylinder heads

Successful process monitoring…

With cylinder head assembly, the requirement is to be able to detect errors from the force/displacement characteristic curve produced when press-fitting the valve seats and to draw conclusions about their causes. The results of all the processes must be stored, so that they can be recalled when necessary. A central PLC is responsible for all machine control.

…with MP85A FASTpress controllers

The new MP85A is linked to the machine control via the industrial Profibus fieldbus. Parallel monitoring on a PC is via Ethernet. As the MP85A units also have Profibus DPV1 functionality, they can be specifically controlled by the PLC. The external tolerances of the cast body interfere with the actual press-fit displacement. Normally this would mean that you would need to increase the “not OK” (NOK) limits of the evaluation system to such an extent that sensitive error recognition would no longer be possible.

Although the external tolerances of the die-cast body are superimposed on the press-fit displacement, reproducible press-fit curves can now be obtained.

Probing the causes of errors

HBM's PME Assistant software offers a wide range of functions to detect errors. Each valve seat on the cylinder head can be assigned its own tolerance window with its own evaluation criteria for the press-fit process. This provides an overview of where on the cylinder head problems occur.