The seat belt is the ideal role of the process: first, timely tightening, the first moment of the accident who did not hesitate to “press” in the seat. Then, appropriate to relax, to be past the peak impact force, or the air bag have to be protected, that proper seat belt to relax. Avoid too large to pull people injured ribs. Seat belts are the most advanced pre-tensioners and tension with a limiter, let us look at the functions of these two principles.
1, Seat Belt pre-tensioners when the accident occurred, the people forward, seat later, at this time if the seat belt too loose. The consequence is likely to be: Crew from the belt slipping out the following: or, who has met the air bags, seat belt at a time when tension over as excessive and failed to tighten, that is not as large as hoped in advance to eat out part of the momentum, but will have all the burden to the airbag. Both situations can cause the crew was seriously injured. But the problem is properly installed seat belts. The loosening of room come from? First, as the crew’s clothing has a certain thickness, another device in the seat belt is also much room for hiding some of the loose, this room can not eliminate, but true case of emergency, it should be possible to eliminate. How do? To this end there is such a seat-belt pre-tensioners which tighten the seat belt is responsible for providing instant. Its process is: first of all by a probe to collect crash information, and then release the electrical pulse, the pulse delivered to the gas generator, the detonation gas. Gas explosion rapid expansion in the pipe, pressure the ball to the so-called chain, so that the ball forward in the tube channeling, driving the ratchet disk transfer. Pawl plate with uranium as a single entity, seat belt on around the shaft. Simply put, that is, the gas pressure to the ball moving, ball transfer disk drive pawl, pawl pivot disk drive – an instant realization of the restraining belts. From the perceived tightening of the accident to complete the entire process of pre-seat belt lasted only thousandths of seconds. Cavity end of the pipe is a length, for accommodating the ball rolled along.
2, Seat Belt tension limiter after the accident, seat belt pre-tensioners in under the action had been tightened. But we hope that the force peak in the past, the seat belt tension strength decreased immediately to reduce the crew by force, the special task to be completed by the seat belt tension limiter: the seat belt device, such as the former one described pre-tightening device, under the paper around the seat belt. Inside is a steel shaft torsion bar. When the load for the intended situation, 3 point Seat Belt reverse the sticks began to distort, so that a certain extent, relaxed seat belts, seat belt force limiters implemented functions.
In the seat belt pre-tensioners and belt force limiter of working together, seat belt protection almost ideal conditions. The so-called spirit in every detail, see, does give advanced passenger seat belts to provide reliable security.