安全气囊（airbag）

安全气囊（airbag） 安全气囊(airbag) Graduation thesis Development and application of airbags Pick to Airbags are located in the front of the car (the front and rear), side side (front and back) and the top three. The "Supplemental Inflatable System" (SRS) is printed on the outside of the container equipped with the airbag System. The literal translation should be "auxiliary Inflatable Restraint System". To reduce the degree of damage caused by a secondary collision of inertia after a collision. As the auxiliary configuration of passive safety, people pay more attention to it. After the automobile collisions with obstacles, referred to as a collision, the occupants collision with the vehicle components, called secondary collision, airbag after a collision, secondary collision before quickly opened a gas cushion, make occupant moves because of its inertia "on a cushion of air" to soothe crew were hit and absorb collision energy, reduce the damage rate of the crew. Keywords: airbag; Passive safety; The degree of damage Orders to record Pick to the I 1 the introduction 1.1 vehicle safety 1 1.2 benefits of airbags 1 1.3 seat belt and airbag relationship 2 2. Action 2 3. Classification of airbag system 3.1 is structured form 3 3.1.1 electronic airbag 4 3.1.2 mechanical airbag 4 3.2 the protected object and azimuth 4 3.2.1 the driver USES airbag 4 3.2.2 anti-side impact airbag 5 3.2.3 front seat occupant used airbag 5 3.2.4 rear seat crew use airbag 6 3.2.5 the lower extremity use airbag development 6 4. Development and application of airbags 7 The U.S. and European airbags are 7 4.2 development of domestic airbags 5. Dismantle and discard 10 Conclusion 10 Reference 10 Thanks to 11 One, the introduction 1.1 automobile safety When the car speed from frontal crash during more than 30 km/h (collision Angle and motor axis into 30 ? Angle) or side collision, installed in the front or side collision sensors using collision inertia force, detect the collision time, vehicle deceleration impact strength. SRSECU will impact collision from sensor signals compared with ECU collision triggered data stored within, if the judge collision strength reach or exceed the specified value, the instruction on airbags detonating tube working circuit, detonating tube explosion burn quickly, and ignition gas generating agent in the gas generator. Combustion of gas generating agent is very intense, in the moment of release of gas, filling the folded airbag after filtering, cooling, the airbag within a very short time break pad ballooned into a flat ball. The driver or occupant head, chest or body due to the collision of recoil force rushed forward or sideways, summon up the balloon in the front of the pilot or crew or side body into elastic buffer cushion between hardware, using the damping effect of the gas itself or the air bag on the back of the vent exhaust throttle damping effect, absorb and disperse the pilot and the crew of the impact energy. The airbag bulges out of the airbag and then gets deflated from the hole in the back of the airbag. The soft airbag can effectively protect the head, chest and other parts of the body from damage or injury. 1.2 benefits of airbags Safety protection range of occupant can provide all kinds of collision accident and roll all-round protection in a car accident when severe frontal crash and side crash, the crew to provide effective protection to the head or chest The reliability of the equipment can be used to check the fault of the system at any time and rely on the diagnostic device for general failure inspection, but it can't carry out the nondestructive inspection of the system parts Ease of equipment need to wear and fastened, even if the automatic seat belts, there is a lot of constraints, the actions of crew can prevent crew from the seat, to passengers crew collision range smaller without any constraints, but in a car collision, occupant may be left out of the chair, over a wide range of collision with the vehicle equipment Maintenance convenience installation, maintenance, replacement are easy to repair more complicated, such as the large failure of the parts, the replacement of a complete airbag system Using the popularity and the cost of universal easy, low cost, no need to improve the total cost is popular the driver and the front car airbags, and as a car loading standard equipment, but the cost is high. Other forms of airbags are temporarily optional 1.3 relationship between seat belts and airbags Electronic control of the secure air bag system with the electronic control of the seat belt and the electronic control of multiple airbags. In the experimental analysis of the intelligent airbag system, the seat belt is found to be very weak in the protection of the driver's head, chest and knee. The airbag is particularly effective in protecting the head, chest and knee, greatly reducing the death rate of the crew and reducing the damage to the crew. It is worth pointing out that the airbag is only an auxiliary protection system, so it is necessary to wear a seat belt to achieve the desired protective effect. Traffic accident statistics show that "three-point seat belt + airbag" is the best protection, with an effective protection rate of up to 60%. With the use of seat belt only, the effective protection rate is 43 ~ 49%; Using only airbags, the effective protection rate dropped sharply to 18%. Citing these statistics helps us to eliminate two myths: first, airbags are not everything. Secondly, wearing seat belts is very important. The unified understanding is that the belt rate must be increased through compulsory measures. In low-speed collisions, the expansion of airbags reduces the likelihood of accidental injury and reduces the protection effect. Airbags have an obvious protective effect on the crew during a moderate or severe collision. Generally speaking, the occupant of the car will be severely injured in the collision of fixed walls with a speed of 20km/h without a seat belt. The occupant of the seat belt will be severely injured in a fixed wall collision of 30km/h. Gasbag internal filling gas in oppressed by the pilot or occupant recoil, able to buffer driver or occupants of collision impact, avoid the driver's head and body with auto parts hard collisions, Thereby reducing the degree of damage to the driver or occupant. But if the expansion of elasticity after the airbag was oppressed by a driver or occupants of recoil when not deflated flat, may be because of the driving personnel head buried can't breathe in the air, breath of death. Or the internal pressure gas allows a resilient air bag to bounce back, causing a secondary collision with other parts of the car, resulting in a secondary injury to the driver. Second, the process of action A. 0 ~ 10ms: device collision sensor at certain sensitive parts of the car. When the impact sensor is sufficiently charged, the signal is sent to the central electronic controller in a flash of 10ms. B. 10 to 20 ms: in the central electronic controller, mainly on the airbag system monitoring and control of the microprocessor, can trigger the sensor input signal immediately calculation, comparison and judgment. If the collision impulse exceeds the preset value, the central electronic controller immediately emits an electrical pulse that causes the detonator in the gas generator to explode rapidly. C. 20 ~ 60 ms: breakdown of detonator explosion of gas generator fuel box, fixed the fuel to ignite and generate high temperature and high pressure gas (nitrogen), quickly after filter cooling into the airbag. The air bag reaches the maximum volume within 20 ~ 60ms, forming a cushion between the occupant and the vehicle. In the same instant, the crew may rush out 150 ~ 200mm with the force of inertia, and the head, face and chest are in contact with the oncoming airbag. But the inflating energy of the airbag will "rebound" the occupant into the seat, which will damage the crew. D. 60 ~ 100ms: at the same time, the vent hole in the back of the airbag opens, the airbag deflates and shrinks. The damping effect of the gas absorbs the energy of the collision, alleviating the pressure on the occupant's head and face, allowing the occupant to slip into the softer airbag. Because the airbag separates the crew from the vehicle, the crew is protected. The last gasses are discharged from the vent and the air sacs are deflated. The whole collision -- the airbag expands the safety protection process of the crew, about 60 ~ 100ms. The process of protecting the airbag is an irreversible process. After completing the above procedure, it must replant the detonator, the gas generator and the folded air bag. Each airbag can only be used once, which means that the airbag will no longer have the ability to protect once it is detonated, nor can it be put back in use again, so that it will be returned to the factory for a new airbag. In the event of car crash, the specific ignition time of the detonator of the air bag detonator is a very important index to determine the performance of the SRS system. If a collision occurs, the detonation tube premature detonation ignition, rushes to the head and chest of the crew at the same time, the air is rapidly expanding, it could lead to crew, head and chest impact of high speed of the airbag, cause great crew casualties or damage. If the detonator detonates the ignition too late, the airbag has not inflated yet to protect it when the crew's head and chest have already bumped into the steering wheel or other auto parts of the car. The best ignition timing of the detonator detonation is when the balloon is filled with gas, and the person's head and chest are in contact with an expanding air bag. As the air balloon begins to swell from the ignition of the gas, it is only about 0.1 s, to be deflated quickly by the driver or crew. Airbags from full of gas expansion to frustrated only such a short time, so you must have very quickly complete air flushing and deflated action function, can effectively protect the driver and the safety of the crew. 3. Classification of airbag system 3.1 in the form of structure In the form of structure, airbags can be divided into two types: electronic and mechanical. Whether it is electronic or mechanical, the principle of work is roughly the same, and the difference is that the control system works differently. 3.1.1 electronic airbag It is composed of electronic sensor, central electronic controller, gas generator and air bag. Sensor, after receiving signal collision would transmit the signals to the central electronic controller (ECU), signal after judgment, confirmed that to gas generator, gas generator spark ignition, inflatable balloon inflation. Electronic airbags can be classified into many kinds of situations. 3.1.2 mechanical airbags It is composed of mechanical sensor, gas generator and air bag. The air bag is placed inside the steering wheel liner, the gas generator under the air bag, the sensor under the gas generator. When the sensor is set (above) after the impulse of the sensor in the ball down, lead to dial the rod down and by turning, block also move, on the other side of the shifter lever up, oppression bias spring. A detonation device is ejected from the impact gas generator. Due to gas generator equipped with sodium azide in double-base fuel or high pressure gas, after the outbreak, coating the surface of the gas filled with airbags, inflated, forming a convex air cushion, absorb the impact of the human body, make human body injury degree of ease. In addition, according to the working principle of the gas generator can be divided into combustion type (such as sodium azide solid fuel explosion produces a large amount of nitrogen with airbag) and gas (high pressure cylinder valves open the door, release ChuHaoDe high-pressure nitrogen gas or inert gas mixture) in advance. 3.2 according to the protection object and orientation 3.2.1 the driver USES airbag The driver USES airbags, the earliest and most widely used airbags in the car, belonging to the car's protective airbag during a head-on collision. Drivers with airbag device in the middle of the steering wheel, in order to reduce the device after the airbag steering wheel assembly quality, and requirements to ensure that the steering wheel stiffness to reduce the vibration of the steering wheel, steering wheel shaft adopts metal die casting to manufacture. Drivers with airbag systems, such as airbags, detonator, gas generator, all in the middle of the steering wheel airbag box, bag liner is made of mesh nylon fabric, which when the airbag inflation and rushed out of the air liner must be quickly opened, and I can't harm the crew. The airbag is folded in a certain way in the airbag box and expands rapidly as it expands in the direction of the windshield. In the middle of the airbag, a detonator and a gas generator, etc., when a collision occurs, The airbag forms a cushion between the driver and the steering wheel. 3.2.2 anti-side impact airbag Collision accidents account for about 41 percent of the crashes, 12 percent of crashes and 47 percent of all kinds of side crashes. But in terms of casualty ratio, the casualty rate of the side collision of the car is far higher than the casualty rate of the head-on collision and tail collision. Analysis results indicate that the front of the car as the nacelle, back as the baggage compartment, in the event of a frontal impact collision or stern chase, engine compartment or trunk structure deformation and structure damage, can absorb a lot of impact energy. And seat belts and airbags can work effectively, which makes the crew's casualty rate substantially lower. However, the structural parts on the side of the car, whether in strength or stiffness, are far less than the strength and stiffness of the longitudinal structural parts of the car. There is not enough space on either side of the door to "buffer" the structure to absorb the energy of the collision. Seat belts are also much less protective of side impact. When the door, the door post and so on the collision, it is possible to cause direct injury to the crew, so that the occupant's casualty rate is greatly improved. Depending on the use requirements, the anti-side bump airbags can be mounted on the side beams of the doors, inside the doors, or the side of the seat. The side impact airbag is used to protect the occupant's head. The airbag is installed in the inside of the car door, and the airbag is used to protect the crew's chest, heart, lungs and other vital organs. 3.2.3 front seat occupants use airbags Crew members on the front seats are major car seats, the crew of the front seats can be a tall man, also can be a baby, crew aboard posture is various, and has important influence on whether to wear a seat belt. In collision accident, the crew members on the front seats must be with the dashboard, before the wind window, window and door frames, such as collision, therefore, request the front seat occupants with airbags can in large range, the crew members on the front row seat to provide a safe protection. The front seat occupant USES airbags as shown in figure 6. The front seat occupants with airbag systems, such as airbags, detonator, gas generator, all hidden in the dashboard of airbags box, according to the structure of the car dashboard, its decorate a method is also different. The air bag liner is made of a sheet of polyurethane plastic that is embedded in a thin lead plate. When the airbag expands and runs out, it does not harm the crew of the front seat. The front seat occupant USES the airbag to be large, the airbag must be folded in a certain way in the upper bracket in the bag box. In air box on the lower bracket of detonator and the gas generator and so on, in the event of a collision, the initial air box guide airbag upward along the direction of the wind window before, and then along the airbag folding marks, orderly rapidly expand in the direction of the front seat occupants, timely in the front seat occupants and dashboard formed between buffering cushion. The volume of the front airbag is 170 l, but from tipping to secure air at the moment only 40 ~ 80 ms, solid fuel combustion of high temperature and high pressure gas quickly filled with airbags, in inflation has a great impact, It's possible to do harm to the occupants of the front seats. Usually in the design and calculation, to fuel combustion speed and the balloon to inflate pressure calculation, made at the beginning of the airbag filling, can control the speed of fuel combustion, the expansion of the airbag speed not too fast. When the airbag begins to contact with the crew, fuel combustion can be carried out at a rapid rate, which can output a large amount of gas to ensure that the airbag has enough pressure to separate the crew from the dashboard. And how in the front seat without a crew, when the car collision, the front seat occupants with airbags will not detonate, "mistaken detonation" accident or not, still need to solve and improve further. Sometimes in front row seats, fixed installation of child seats. When a child is seated in front of the room, the front seat passenger should use the airbag to detonate normally, but must control the explosive force to avoid harming the child. If children toward the sat, seat provide reliable safety protection can give children (above 90%), and this is the astronaut reverse take seat, able to withstand inspired great inertia force, to develop and design, the child seat. Therefore, when a car crashes, it is not necessary to detonate the front seat occupant to use the airbag, the whole operation is controlled by the intelligent airbag system. The front-row seat occupant used airbags. The rear seat crew USES airbags 后排座 usually can set safety protection devices, but in recent years to 后排座 occupant safety protection gradually be taken seriously, have a common ground on 后排座 device seat belts, and development and device 后排座 crew with airbags (including 后排座 crew with the side impact airbag). 后排座 commonly between the front seats have more capacious space, occupant is larger in space and the location of the foot, therefore, the volume 后排座 occupant with airbags, than the front seat occupants with airbag the large volume of more than 50%, generally can reach 100 l, 后排座 crew with the structure of airbag system and other safety air bag system basic same, most is installed in the front seat in the back of a chair, after the detonation 后排座 crew and forming a protective cushion between the front seats. In the rear air bag system, two collision sensors are required to detect the acceleration of the car before and after the collision. After the calculation and determination of the central electronic controller, the airbag of the rear seat can be detonated. 后排座 crew with airbag volume is very big, will cause a sharp changes in air pressure inside the car, and a strong vibration and noise, huge noise make occupant unbearable, serious still can damage the occupant of the eardrum. Effective measures are required to prevent. The detonation time of each airbag in the car is usually staggered, avoiding vibration and noise. 3.2.5 the lower extremity use airbag development Moton International has developed an airbag that protects a driver's lower limbs, made up of a 13L airbag gas generator, a newly developed airbag. Collision in a car, can effectively prevent the pilot of the lower extremities, calf and knee with all sorts of pedals, operating levers, such as collision, the driver of the lower extremities, calf and knee, for their own protection. When the lower limbs are opened with airbags, It can cause the front of the crew to raise a certain Angle upward to reduce the damage of the heel. And prevent the pilot's body forward, keep drivers' body in the right place, at the same time to absorb part of the collision of inertia force, make drivers to reduce the power of the femur by nearly 33%, reduced to about 5 kn can afford, and can reduce the driver and the driver with airbag collision force. The structure of the lower extremity airbag device in the front panel of the lower part of the dashboard is similar to that of other airbag systems. The development and application of airbags 4.1 comparison of airbags in the us and Europe In the United States, airbag systems require security for passengers who are not wearing seat belts. Obviously, for passengers who are not wearing a seat belt, it is possible to do damage to crew members even when a car crashes at lower speeds. Therefore, when setting the range of the airbag starting speed, the vehicle will hit the fixed object at the speed of 18 ~ 20km/h, and the airbag can ignite and explode. Require speed in 18 ~ 20 km/h, airbag ignition initiating, requires the airbag system in the sensor and the electronic controller has the characteristics of collision with a high degree of recognition and high reliability. On some cars, due to the sensor and the electronic controller for cars in severe emergency brake or speed is 15 km/h the following slight collision, produce "judgment", and produce airbag "mistaken", make drivers by sudden fright, the bulging of the airbag will also cover the driver's line of sight, short time caused due to the sensor of impact properties identification capability and the reliability of the error caused by the accident. Of sensor and the electronic controller, therefore, have a high demand, because not to wear a seat belt of crew in the vehicle collision, the crew without seat belts constraints, and reduce the effect of inertia force, occupant may be left out of the chair, and in a larger scope of ferocious secondary to collide with the car's equipment. As a result, the airbag system requires larger airbags to separate the crew from the vehicle in larger areas. As a result, the driver USES the air bag to reach 60 ~ 80L, and the front seat occupant USES the air bag to reach 120 ~ 160L. In Europe, according to the rules and regulations, car seat belt must be assembled, and force all passengers must wear a seat belt, three-point seatbelt can completely in the car collision speed of 30 km/h, provide good tighten and protection for crew. However, the test results show that the seat belt can not provide effective protection for the driver and occupant's head and face when the collision speed exceeds 30km/h. On the basis of using the three-point belt, the airbag system is developed to improve the safety protection. When a car crashes, it is mainly safe to bring in the crew and bear the main inertial forces. The airbags are used to protect the head and face of the occupants. Airbag airbag starts up speed of 30 ~ 40km/h, making it less likely and less dangerous to produce "false explosion" of airbag. In this airbag system, single point sensor and other devices can be used to control the system, making its control system easier. As a result, The airbag system in Europe, the driver with airbag volume for 20 ~ 30 l, the volume of the front seat occupants with airbag is 60 ~ 80 l, the airbag system than the United States in the gasbag volume is much smaller and can realize miniaturization, more suitable for equipped with seat belts in medium and small cars equipped with air bags. From the above comparison, it can be seen that in the development of airbag system in the United States and Europe, the guiding ideology is different and there are obvious differences. The european-style airbag system is suitable for small and medium-sized cars fitted with seat belts, and a safety system for cars with seat belts. But in some of Europe's biggest luxury cars, they are also equipped with a us-style passive airbag system to meet export and market competition requirements. Some countries in the United States and Europe are the first countries and regions to develop and use airbags. Seatbelts and airbags form the vehicle auxiliary protection system. In the process of the development of the development of seat belts and airbags, around the seat belts and airbags in protecting occupant of the Lord, from the role of the relationship, between the United States and some European countries formed two different thoughts of development of airbag, and formed the two different kinds of airbag system - American airbag system and European airbag system. The two different arrangement of airbag system method, and the configuration of sensors, the performance parameters of the central controller, air volume and speed of airbag startup car, etc., have bigger difference, as shown in table 7. But the airbag system works basically the same way. 4.2. Development of domestic airbags In our country, car airbags started late in the late 1980s and early 1990s. During the research and development process of more than a decade, many universities and enterprises in China have begun to study and develop their products. Some of these research and technology are close to the international level. The development trend of airbag technology in the future will mainly develop in the following directions: (1) intelligence With the rapid development of electronic information technology, all kinds of intelligent technologies are widely used in automobiles. Intelligent airbag is one of them. It is made by adding sensors and matching computer software on the basis of ordinary airbags. Its weight sensor can according to the weight sensing passengers are adults or children, its infrared sensors can according to the heat detectors seat is people or goods, the ultrasonic sensor can proved the existence of the crew and location, etc. Computer software can according to the passenger's body, weight and whether the location and seat belts and car collision speed and the degree of impact, adjust the expansion time, speed and degree of airbag, the airbag for passengers to provide the most reasonable and effective protection. (2) environmental protection It is commonly used in automobile airbags. In terms of environmental protection and human health, sodium diazide is a toxic substance that is nearly 30 times more toxic than arsenic. In addition, from a security point of view, overlapping sodium nitride after being activated releasing gas rushed up the balloon at the same time, also generates solid sodium, sodium in the chemical nature very lively, especially when in contact with water can be burned directly. As a result, To avoid the use of potentially dangerous and toxic substances containing sodium, a new type of gas generation technology can be used to meet environmental protection requirements, which is a direction of the development of airbag airbags. (3) virtual technology A computer simulation of "virtual technology" is used to replace car object collision. It is a "virtual experiment" by a supercomputer that reduces human, physical and financial costs. On the other hand, the product development cycle is accelerated. Super computer is located in a room is equipped with sophisticated climate control system in the computer room, to simulate the collision test, on the one hand, the design of the measuring car to reduce the risk of drivers and passengers were injured can have how much effect, on the other hand the car by collision deformation, and such as seat belts and airbags protection system should be how to design, can achieve the best protection effect. And all sorts of operations are based on the kind of accidents that happen in real traffic. (4) small and light The airbag assembly will adopt a new type of gas generator with small volume, which USES a mixture gas generator with compressed gas and a pure gas generator with organic gas. In addition, the airbag as a highly integrated systems and modules, Delphi sensor company will launch the world's smallest airbag module, make the steering wheel is both beautiful and concise, and there is enough space to integrate more control system. Delphi's technology can provide a highly compact crew front to protect airbags, and the gap between the cover of the air bag system and the steering wheel is very small and almost invisible. The installation is also unique and the steering wheel looks more beautiful. (5) protecting the omni-directional Airbags are no longer limited to protecting drivers and former occupants. The modern car will also adopt the curtain of the side air bag, so that even if the side is hit, the safety of cabin crew can be fully guaranteed. Dismantling and scrapping To use time more than 10 years of automobile and airbag dismantling scrapped automobiles, or removed due to the need of experiment, on the outskirts of special need empty Spaces for waste airbag blasting, and under the professional operation. If the airbag is detonated by the operating procedure, the airbag should not be detonated normally (the squib), after at least 10min, after careful inspection, after troubleshooting, re-detonation. Staff must wear safety equipment. Any spare parts or equipment for airbags that have been scrapped shall be strictly prohibited to be reused. The airbag system is widely used in foreign countries, and it is also about to be used in a large number of cars in China. Airbag installation, especially the dismantling of airbags, for car repair shop, need to have a special place removal, and by the strict training of technical personnel to carry out, otherwise, will cause harm to personnel and has larger public nuisance. conclusion The airbag must be used with a seat belt. If you don't wear your seat belt during the drive, the balloon will cause a lot of damage to the crew when it pops up. 2. Notice the airbag switch in the vehicle. Some of the vehicle's co-pilot airbags have a manual switch, and if they are "closed", the airbag will not be opened when the vehicle crashes. Try not to put children in the passenger seat. Airbags have a powerful impact when they start to explode. Children are short and weak and vulnerable to unexpected injuries. Try not to wear frame glasses while driving. If the driver wears glasses during the ride, one but the airbag pops up, the broken lens material may cause serious damage to the eye. reference A Review [J]. A Review [J]. IEEE Trans. On Pattern Analysis and Machine Intelligence, 2000, 22 (1) : 4-38. [2], and so on. The working principle and maintenance technical points of the driver airbag. Inner Mongolia road and transport. [3] 16. Hu guanghui. The safety of airbags is first explored. Hunan transportation technology. [4] yellow ningjun, etc. The new development of car seat belt airbags. 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