Presentation on theme: "Cars so important in nowadays, and we can not live without it. Even so we must be careful when we use it because it can be so dangers. This presentation."— Presentation transcript:
Cars so important in nowadays, and we can not live without it. Even so we must be careful when we use it because it can be so dangers. This presentation will discuss the main car safety issue.
OUTLINE Tyres Traction control Brakes Crash avoidance Air bags Safe vehicle interiors Safety belts Seats Crush zones and safety cages Seeing and being seen Adjustability and comfort Risk
Tyres Tyres are one of a vehicle's most important safety features. Whenever a vehicle accelerates, corners or brakes, it imposes forces on its tyres. Good tyres grip the road to allow a vehicle to stop, go and corner safely, which can be crucial in avoiding crashes
Tyres ( cont.. ) Choosing the right tyre depends on the type of vehicle it will be fitted to and how the vehicle will be used. Tyres that may be suitable for a passenger car used for city driving could be unsuitable for a vehicle carrying heavy loads or used off-road.
Tyres ( cont.. ) Tyre inflation Having your tyres inflated properly could save your life and will certainly save you money. Correct tyre pressure is vital for balanced braking, maximum grip and long tyre life. Many accidents occurred because of the unbalanced pressure.
Tyres ( cont.. ) Tyre Rotation Car tires gets old with time and the type of use So rotation must be implemented on the four tires as show in the figure. This must be done every 5000km to achieve equal rate of wear. Front wheel car rear wheel car
Tyres ( cont.. ) How to buy a safe tyres for your vehicleHow to buy a safe tyres for your vehicle 1.Check the size 2.Speed Rating 3.Load Indices All of the above are imprinted on the sidewall of the tyre
Tyres ( cont.. ) How to buy a safe tyres for your vehicleHow to buy a safe tyres for your vehicle Check the size by ISO Metric Sizing System The International Standards Organization (ISO) Metric system combines the Metric system with a service description. The service description provides the load index along with the speed rating symbol.
Tyres ( cont.. ) How to buy a safe tyres for your vehicleHow to buy a safe tyres for your vehicle Speed Rating All tyres carry a speed symbol in the form of a letter indicating the maximum speed for which the tyre is intended. This indicates the maximum speed that the tyre can sustain for a ten minute endurance without coming to pieces and destroying itself and the car it is on. Speed Categor y Symbol Speed (km/h) Speed Categor y Symbol Speed (km/h) D65Q160 E70R170 F80S180 G90T190 J100U200 K110H210 L120V240 M130W270 N140Y300 P150Z300+
Tyres ( cont.. ) How to buy a safe tyres for your vehicleHow to buy a safe tyres for your vehicle Load Indices The load-index figure imprinted on the sidewall of the tyre denotes the maximum load capacity of a tyre when driven at maximum speed. LIKgLIKgLIKgLIKgLI 04540140804501201400160 146.241145814621211450161 247.542150824751221500162 348.743155834871231550163 45044160845001241600164 551.545165855151251650165 65346170865301261700166 754.547175875451271750167
Traction control Traction control helps limit tire slip in acceleration on slippery surfaces. In the past, drivers had to feather the gas pedal to prevent the drive wheels from spinning wildly on slippery pavement. Many of today's vehicles employ electronic controls to limit power delivery for the driver, eliminating wheel slip and helping the driver accelerate under control
Traction control Traction control deals specifically with lateral (front-to-back) loss of friction during acceleration. In other words, when your car accelerates from a dead stop, traction control works to ensure maximum contact between the road surface and your tires. For example, a wet or icy road surface will significantly reduce the friction (traction) between your tires and the pavement. And since your tires are the only part of your car that actually touches the ground, any resulting loss of friction can have serious consequences.
Traction control Let's say you're at a stoplight on wet pavement. The light turns green and you press too firmly on the accelerator pedal. There is slick asphalt under your tires and the wheels begin to spin. The traction control system instantaneously kicks in, sensing that the wheels have begun to slip. Within a fraction of a second, this data is fed back to the control unit, which adjusts throttle input and applies braking force to slow the wheels (some older systems also retarded engine spark). The wheels are thus prevented from spinning and the car maintains maximum traction.
Brakes ( ABS ) ANTI-LOCK BRAKE SYSTEM (A.B.S.) The vehicle's active safety is further increased by the latest in A.B.S. technology, which provides control of the vehicle and maximum tire grip even in panic braking and reduced road adherence (ice, snow, etc.). Experimental testing has determined the behavior of the vehicle during braking with different type of tires and surface conditions: it was noted that the maximum braking action is provided when a certain degree of tire slippage is reached, and suddenly decreases when this value is exceeded. The A.B.S. actuates right at this point, and provides the most effective braking action which can be obtained for the existing tire and road conditions
Crash avoidance The best way to not crash is by trying to avoid the crashes it self. And you can do it by 1.Turning the steering wheel to avoid the crash 2.Keep enough distance between the cars 3.Consternate in the driving
Air bags Air bags are standard equipment in most new cars and are planned to work as restraint system supplements to lap/shoulder belts for front-seat occupants in frontal collisions.
Air Bags Can Help or Harm:
How Air Bags Work: There are three parts to an air bag that help to accomplish this feat: 1.The bag itself is made of a thin, nylon fabric, which is folded into the steering wheel or dashboard or, more recently, the seat or door. 2.The sensor is the device that tells the bag to inflate. Inflation happens when there is a collision force equal to running into a brick wall at 10 to 15 miles per hour (16 to 24 km per hour). A mechanical switch is flipped when there is a mass shift that closes an electrical contact, telling the sensors that a crash has occurred. The sensors receive information from an accelerometer built into a microchip
How Air Bags Work: 3. The air bag's inflation system reacts sodium azide (NaN3) with potassium nitrate (KNO3) to produce nitrogen gas. Hot blasts of the nitrogen inflate the air bag, which literally bursts out of the steering wheel or dashboard as it expands. About a second later, the bag is already deflating (it has holes in it) in order to get out of your way
Safe vehicle interiors 1.Steering wheel and steering column 2.Padding and edges 3.Knee bolsters
Steering wheel and steering column Hitting the steering wheel can give drivers serious head injuries. An air bag and safety belt can help prevent these injuries, but the steering wheel can also be designed to lessen the impact Padding and edges All surfaces an occupant may strike in a crash should be as safe as possible. For example, the dashboard, door panels, roof, sun visors, mirrors, header rail and pillars should have thick energy-absorbing padding with no sharp edges underneath
Safety belts How safety belts protect you They prevent or minimise the impact of the occupants against the vehicle interior and each other. They stop the wearer from being thrown from the vehicle. They help absorb the wearer's inertial energy, allowing the wearer to slow at a rate similar to the occupant compartment
Seats A vehicle's seats can be very effective passive safety features. A seat should be comfortable, but must also be sturdy enough to withstand a lot of force and protect its occupant in a crash.
Crush zones and safety cages Crush zones: rear and offset crashes The front and rear Safety cages: strong pillars barriers Door locks and hinges
Seeing and being seen A safe cars features : Windows Lights
Seeing and being seen (cont..) Mirrors
Seeing and being seen (cont..) Wipers and demisters
Adjustability and comfort Mirrors Seats and safety belts The steering wheel Air-conditioning
Risk The risk of a pedestrian dying when hit by a vehicle travelling… at 30 km/h: 10 % at 50 km/h: 70 % at 60 km/h: 90 % at 70 km/h: 98 %