GF91.60-P-2011GM Deploying of Pyrofuse, Function

GF91.60-P-2011GM Deploying of pyrofuse, function
- with ENGINE 642 as of model year 2009 [164.8]
- as of SOP [model 164.195]






General function requirements
^ Circuit 15R ON

Deploying of pyrofuse, general
Model 164.8:
To avoid any possible fire hazard following a crash event, it is necessary to disconnect the battery (G1) quickly from the on-board electrical system.

Model 164.195:
To prevent possible hazards from electric shock and fire after a crash, it is necessary to switch off all energy-producing high voltage components..

Function sequence for triggering the pyrofuse
The pyrotechnical separator (K88) is deployed after a crash event has occurred. The restraint systems control unit (N2/7) actuates the pyrotechnical separator directly.

As the result of an electrically controlled pressure pulse (1), an insulated piston (2) located in the housing of the pyrotechnical separator moves against the predetermined fracture point of the busbar (3) and thereby cuts it quickly and reliably.

Model 164.8:
The main line to the battery is routed over this busbar inside the housing of the pyrotechnical separator.

Model 164.195:
The control line (circuit 30c) is routed over this busbar to the high voltage components inside the housing of the pyrotechnical separator.







Deployment sequence:
- The deployment signal from the restraint systems control unit reaches the pyrotechnical separator and starts the deployment process (A).
- After t = 300 microseconds, the piston movement starts (B).
- After t = 450 microseconds, the busbar is cut (C)

The illustrated deployment sequence shows the function over time and clearly illustrates the speed advantage compared with conventional fuses.