Hottest non rotating driver airbag

2022-07-27
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Non rotating driver airbag

fmvss208, the federal motor vehicle safety standard of the United States, poses new challenges to vehicle designers, making them reconsider whether the shape of the driver's side airbag meets the new requirements. The latest tests suggest that the asymmetric design and non rotating driver airbag module, in particular, provide the possibility of improved crash protection for vehicles with solid cabs

up to now, the airbag of standard driver airbag has been designed in a symmetrical circular shape. This structure provides the same average protection capability in all steering states (when the steering wheel rotates, the airbag module also rotates)

however, recently adopted safety regulations such as federal motor vehicle safety standard (FMVSS) 208 and new vehicle design tend to use non rotating driver airbag modules with airbag bags that match each vehicle interior style

I. user testing and regulatory requirements

many vehicle manufacturing companies provide their products to the world and must meet all markets (North America, Europe, Asia Pacific). In various safety tests, the seat belt is used or not used; There are European new car assessment program (euron-cap) or American new car assessment program (usn-cap) and offset variable barrier (ODB) or rigidbarri er. These different kinds of tests put forward potential collision requirements for the construction of driver and passenger restraint system. Some manufacturing companies choose to develop constraint system components suitable for different markets in order to develop global resources more effectively and finely

during the development of the vehicle occupant restraint system, the designers used the doe:designofexperiments to investigate all the parameters that can affect the occupant restraint system until the optimal solution to minimize occupant injury was reached. These parameters include the performance of seat belt load limiter, seat belt pretensioner, airbag gas generator, overall dimensions of airbag airbag, airbag vent and steering column deformation characteristic values. However, the stiffness of vehicle structure is still one of the main factors affecting the performance of occupant restraint system

another important parameter is the airbag shape, which may play an important role in solving a series of collision problems. In the 40km/h0 ° test (using a 50th percentile dummy without safety belt) conducted in accordance with fmass208, by shifting the center of the circular airbag by 1oomm (forming an asymmetric airbag shape) in the vertical direction, the chest deceleration value can be improved to a level of 20%, which is lower than the previous limit value. At the same time, all other injury indicators can remain at their original levels. Asymmetric air bag has high-performance protection ability to improve damage value

a considerable number of vehicles are difficult to pass the crash test of the new fmass208 regulation without seat belts (see Figure 1). According to fmvss208 regulation, the 30 ° oblique impact simulation test of medium-sized vehicles in trwautomotive (Trinasolar Automotive Group) automotive safety system company shows that the maximum injury value improvement reaches 60%. This is the value obtained by changing the standard circular airbag of the symmetrical airbag (see Figure 2)

II. Determination of air bag shape of airbag

the air bag shape of airbag should be suitable for the interior decoration of the vehicle. According to the requirements of collision and OOP (outofposition), the geometry of air bag can be defined by data analysis method. The air bag is verified by actual static and dynamic tests (see Figure 3). Various optimization closed loops (Systems) are used to verify the most effective airbag shape with the help of data calculation methods (see Figure 4). The optimal airbag first determines different dynamic performance and 00P shape through data test in the whole restraint system. After the airbag shape is accurately corrected, the actual test phase begins (see Fig. 5 and Fig. 6)

any new airbag shape must meet and exceed the determined low injury values. These values are reached when other shapes are released and reinforced materials are used in the case of standard round airbags obtained through the new vehicle assessment program (usn-cap) and OOP test in the United States

the more advantage of the non rotating driver airbag is that the injury value will remain at the same level as all steering wheel positions, that is, the so-called "duecare" position

III. principle of non rotating driver airbag module

static airbag module and rotating steering wheel are installed in two devices. The patented cone wheel device (conegear) in the airbag compensates the rotation of the steering wheel, and thus often keeps the airbag at the 0 ° position. The center of the steering wheel is aligned with the center of the steering column (see Figure 7). The speed of the steering wheel and the steering column remains the same. Only one fixing point must be provided to the steering column switch. Another advantage of this working principle is that if it is not lit, the speed will not be displayed. The patented cone wheel device can only be used between the airbag module and the steering wheel as a guide mechanism. This means that the steering force acts directly on the steering column rather than on the cone gear. Therefore, the cone wheel device has the minimum wear, which is more convenient to meet the quality requirements of reliability

IV. comfort and design features

multi function switch is recommended for non rotating driver airbag module. When the steering wheel is turned, the driver will use the switch in the same position. The drop arm switch (used for turn signals, wipers, etc.) can be used as a multi-function switch integrated into the non rotating driver airbag module. The additional design unit and instrument panel display can also be integrated into the non rotating driver airbag module

v. improved safety performance and increased design freedom

the driver airbag module can provide greater design freedom, so that the shape of the airbag can be applicable to the internal layout of each vehicle

in the data analysis conducted by TRW, it is not easy to be damaged. In the actual test analysis, it shows that the asymmetric air bag can provide a greater ability to reduce injuries for drivers who do not use the safety belt. In the analysis and investigation, it is learned that the improvement level of the maximum injury value in the fmass20830 ° oblique angle test to prevent the head from colliding with the A-pillar has reached 60%. At the same time, the optimal injury value has hardly changed in the new car evaluation program and OOP static test in the United States

in addition to the better performance provided by the non rotating airbag, it also achieves better comfort and design features. The instrument panel display can be set in the driver airbag module. The steering arm switch can also be integrated into the non rotating airbag module as an auxiliary multi-function switch, which helps to reduce the additional cost

the asymmetric airbag first developed by TRW has been put into mass production this year and is used by European vehicle companies. (end)

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