Roll bar crash deployment function - GF91.59-P-2001R

MODEL 230 

Fig 1: Identifying Roll Bar Crash Components

Courtesy of MERCEDES-BENZ USA

Roll bar crash deployment  occurs when:

• the sensor integrated in the RVC control module (N52)  signals that a vehicle tilting angle of 57° has been exceeded for more than 100 ms, or
• the vehicle acceleration in any direction is more than three times greater than normal g-force.

Function 

Automatic raising  of the roll bar takes place in a fraction of a second:

The RVC control module (N52)  actuates the roll bar deployment solenoid (Y57/1)  , which then separates the hydraulic cylinder (2) from the roll bar spring system. The roll bar then shoots to its limit position due to the spring power (5)  . This procedure is accompanied by a crunching noise  , since the locking pawl (4)  is not lifted during the raising procedure, but remains engaged in the gear rack.

Just before reaching the limit position the impact is cushioned by an oil damper. The gear rack with locking pawl locking prevents the roll bar from being pushed back into the body if the vehicle rolls over.

Reaching the upper limit position is signaled to the RVC control module (N52)  by the top/bottom roll bar limit switch(S83/10)  .

Crash deployment during manual operation 

Crash deployment has priority over manual operation.

Vario roof operation after roll bar crash deployment 

If the Vario roof switch (N72s16)  is operated after roll bar crash deployment, the roll bar is initially "captured  ". The motor (A7/5m1)  of the RVC hydraulic unit (A7/5)  is automatically switched on for a short time in order to guide the roll bar hydraulic cylinder (2)  to the roll bar so that the lock (7) of the roll bar hydraulic cylinder (2) can re-engage into the RVC deployment solenoid RVC (Y57/1)  .

Subsequently, normal Vario roof operation and roll bar manual operation are possible again.