#
PRE-TENSIONER SEAT BELT CONSTRUCTION/OPERATION

BME081057630T01

## Construction

.

1 | Retainer
2 | Flywheel
3 | Hook spring
4 | Lock gear
5 | Pawl spring
6 | Torsion bar
7 | E-ring
8 | Locking base
9 | Pawl
10 | Stopper
11 | Spacer
12 | Housing
13 | Guide drum
14 | Holder
15 | Sensor case
16 | Weight
17 | Actuator
18 | Chamber
19 | Clutch gear
20 | Gas generator
21 | Case
22 | Sealing pin
23 | Pin holder
24 | Inlay
25 | Strip cutter
26 | Strip
27 | Clutch sleeve
28 | Clutch pin
29 | Chamber plate
30 | Spring case
31 | Bush
32 | Spring
33 | Spring cover

## Operation

### Before activation (Normal condition)

  • The clutch sleeve is separated from the movement of the clutch gear.
  • The clutch gear is connected to the torsion bar through in the guide drum, and rotates freely according to the movement of the belt.

1 | Strip
2 | Clutch sleeve
3 | Torsion bar
4 | Clutch gear
5 | Belt

### During activation

  • The pre-tensioner operates as follows.
  1. When the pre-tensioner receives a signal to operate from the SAS unit, the gas generator releases a gas, which increases the pressure of the chamber inner. This pushes the strip and causes it to expand.
  2. The clutch sleeve rotates counterclockwise according to the movement of the strip.
  3. The clutch pin engages the clutch gear by the rotation of the clutch sleeve, and then the clutch gear rotates the torsion bar and the guide drum together, and retracts the belt.

1 | Strip
2 | Clutch sleeve
3 | Torsion bar
4 | Clutch gear
5 | Belt
6 | Clutch pin
7 | Gas