The seat belt tensioners (1) are installed on both front seats and are firmly connected to the belt buckle. In the event of a frontal collision, they ensure that the seat belt fits tightly to the body and prevents the front passenger from sliding under the belt. In the event of a severe frontal impact, the seat belt tensioner is triggered together with the airbag. Both tensioners are triggered simultaneously even if there is no passenger in the front seat.
When the tensioner is triggered, the charge in the capsule is ignited electrically. The released gases push the piston in the tube forward. A cable is attached to the piston, which pulls the seat belt buckle down through a rotary element. The belt is tensioned by 60 mm in about 0.005 seconds. Thanks to the locking mechanism in the housing, the piston is clamped in the forward position.
1. Seat belt buckle; 2. Piston; 3. Housing with locking mechanism; 4. Capsule with charge; 5. Ignition unit; 6. Pivot element/attachment point; 7. Tension cable.
(Original material on the website: www.MAZbook.ru)
The seat belt tensioner is not serviceable. After activation, both tensioners must be replaced as a unit. The activated tensioner can be identified by the locked seat belt, which no longer twists.
Precautions: Installation work on the front seat belts or tensioners should only be carried out in a workshop; before disposing of a faulty tensioner, it must be discharged in a workshop.