Deploying of pyrofuse, function - GF91.60-P-2011GM

MODEL 164.195 

MODEL 164.8 with ENGINE 642 as of model year 2009 / YoM 08 

MODEL 164.8 with ENGINE 273 as of model year 2010 / YoM 09 

MODEL 164.1 with ENGINE 272 as of model year 2010 / YoM 09 

Function requirements, general 

Circuit 15R ON

Deploying a pyrofuse, general 

Except model 164.195: To avoid any possible fire hazard following a crash event, it is necessary to disconnect the starter (M1) and alternator (G2) quickly and reliably 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.

Except model 164.195: 

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

Deployment sequence:

- The deployment signal from the restraint systems control unit reaches the pyrotechnical separator and starts the deployment process (A).

- After t = 300 s, the piston movement starts (B).

- After t = 450 s, the busbar is cut (C)

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