Tuesday 11 April 2017

How does a Car work





When you’re riding in a car, you may not necessarily think about what’s making it go, aside from the grown-up in the driver’s seat. But in truth, cars get their power and their ability to move from their very special construction and from energy-filled substances that fuel them.

If you’ve ever been to the gas station, then you probably already know that cars need gasoline, or petroleum, to run. The car’s engine runs on a mixture of gasoline and air. Just like a hot fire gives off energy when it burns, so does the gasoline! The spark that gets the whole thing going comes from the car’s battery, which gets powered when the driver turns the key in the ignition.


Once the whole thing is going, the energy the car gets from the gas it burns moves the car forward! A special part of the car called the “transmission” passes all the energy from the engine to the wheels. The driver then uses the wheel to steer and guide the car in the direction in needs to go, and uses the car’s brakes to slow the car down when at a stoplight or when arriving at the destination!



The Transmission

Controls the power contained in the crankshaft before it goes to the wheels and allows a driver to control the speed/power of a car by providing different speed/power ratios known as gears.So first gear gives plenty of power but little speed whereas fifth gear provides little power but plenty of speed.The crankshaft only connects to the transmission when the car is in gear and the clutch is engaged. If you press down on the clutch the crankshaft disconnects from the transmission.The transmission is connected to the output shaft, which is connected to the axles, which are connected to the wheels. When the transmission rotates the output shaft this turns the axles, which in turn rotate the wheels.







How a Motor Engine Works

The more you understand about your car, the more capacities you will have to keep it running the correct way and to know where the trouble spots could be if it is not running as efficiently as you would like. If you want to ensure that your car keeps going the right way, one of the first things you want to understand is the motor and how it connects to everything in your vehicle. This will allow you to make adjustments needed and to have better knowledge of the vehicle that you have.




The motor of a car is like the heart of your vehicle. It is the one thing that connects everything together and ensures that your car continues to move. It’s main purpose is to transfer the gasoline that moves into the engine area and then to move it back out so that your vehicle as fuel to run on. The motor is what will propel the gasoline into the various areas of the car, pushing it into the motion that keeps everything running effectively.

Even further than this, everything that is connected to the engine also allows it to keep running at it’s best. The first of these is the set of spark plugs that moves into the engine. When the engine pushes up, it will hit the spark plugs. When this happens, it will cause the spark plugs to ignite and will turn on the engine. When this happens, the gasoline is then able to push up through the cylinder of the engine and releases into an exhaust pipe. This is the cycle that the motor will follow in order to release the energy to move.

In order to keep the motor engine completely functioning, there are other components that also allow the engine to continue to run smoothly. The first of these is the connecting rod, which is used as a support area as the piston rotates and releases the gas. The second is the crankshaft, which is used in order to keep the piston turning so that it can release the necessary gasoline at the right time. The last of these is the sump, which will collect the oil and lubricate the engine piston and other parts of the motor as they are turning, allowing for a smoother ride.



Take a close look of Internal combustion system:



1. Intake stroke – intake valve opens and the piston moves down allowing the fuel-air mix to enter the open space.

2. Compression stroke– the piston moves upwards. This compresses the fuel-air mix by forcing it into a smaller space. Compression makes the fuel-air mix explode with greater force.
3. Power cycle – spark from a spark plug ignites the fuel-air mix. The explosion forces the piston down the cylinder.

4. Exhaust cycle – the exhaust valve opens and the piston moves back to the top of the cylinder which forces the exhaust fumes out.

As these all move together, the motor is able to continue turning and allowing for the car to move forward with the fuel that it is given. By the continuous turns and movements of the motor is the ability to push your car forward with some simple steps that allow for the wheels on your car to keep turning.

The bottom of each piston is attached to the crankshaft.As the pistons are forced up and down they rotate the crankshaft, which after sending the power through the transmission, turns wheels.Most cars have at least four cylinders. More powerful cars have more. For example a V6 has six cylinders and a V8 has eight.The harder a driver presses on the accelerator pedal the more fuel-air mix is passed into the cylinders and the more power is produced.What Are Revolutions Per Minute?

The four-stroke cycle repeats itself thousand of times a minute. These repetitions are more commonly known as Revs.A rev counter tells you how many thousand times per minute the cycle is repeated.





Two Stroke & Four Stroke Engines 

Stroke refers to the movement of piston in the engine. 2 stroke engines make piston move twice and 4 stroke engines piston moves four times in all the directions. Each movement of the piston (stroke) is characterized by a unique activity of compression of fuel and generation of power. So what exactly is the difference between 2 and 4 stroke engines? Let us find out:

Piston moves only twice in a two stroke engine. The first movement is called the compression stroke and the second stroke is called the power stroke.
Compression stroke: Compression stroke is an act of compressing fuel. During compression stroke piston goes up compressing the fuel in to the engine.
Power stroke: Compression stroke is followed by power stroke. During a power stroke the fuel is ignited, which pushes the piston down producing a lot of power and torque. It also involves in taking new fuel and air to start compression again.

In a four stroke engine, the piston moves 4 times i.e. two sets of ups and downs. The movements are characterized as follows:
Compression stroke:During this stroke fuel is compressed. The compressing is essential to generate power at the later stages.
Power stroke:The fuel ignites and moves the piston down. The act of moving down produces power and torque.
Exhaust Stroke:The piston again goes up and drives the power emitted and fuel out of the exhaust valve.
Intake stroke: The piston again goes down and draws new amount of fuel and air ready to compress again.

Thus as you can notice that two stroke engines involves only two moves and 4 stroke moves 4 times.

Basic Features: As a 2 stroke engine receives power stroke twice than that of four stroke engines they generate more power and torque. Also, 2 stroke engines are noisier when compared to four stroke engines.
2 stroke engines does all the act of exhausting and taking fuel in at a single stroke i.e. power stroke, it is more polluting.
2 stroke engines want more lubrication when compared to four stroke engines. One will have to keep the engine lubricated frequently (oiling) for smooth riding experience.
2 stroke engines are not suitable for long term as they tend to produce more noise and pollution simultaneously.
4 stroke engines are fuel efficient, smoother riding experience, less polluting and least noisy.
4 stroke engines do not emit as much smoke as 2 stroke ones do. They also have a long term life.

The Final Verdict: Though a two stroke engine emits more power and torque, they are not suited for the day to day activity. Moreover, they are not fuel efficient, have a short life, polluting agent and also noisier than 4 stroke ones. Therefore, 4 stoke engines should be preferred as they are more fuel efficient, less polluting, and affordable. 4 stroke bikes are ideal for day to day activities.


Anti-lock braking system (ABS)

Anti-lock braking system is an automotive safety system that allows the wheels on a motor vehicle to maintain tractive contact with the road surface according to driver inputs while braking preventing the wheels from locking up (ceasing rotation) and avoiding uncontrolled skidding. It is an automated system that uses the principles of threshold braking and cadence braking which were practiced by skillful drivers with previous generation braking systems. It does this at a much faster rate and with better control than a driver could manage.

The theory behind anti-lock brakes is simple. A skidding wheel(where the tire contact patch is sliding relative to the road) has less traction than a non-skidding wheel. If you have been stuck on ice, you know that if your wheels are spinning you have no traction. This is because the contact patch is sliding relative to the ice. By keeping the wheels from skidding while you slow down, anti-lock brakes benefit you in two ways: You’ll stop faster, and you’ll be able to steer while you stop.

There are five main components to an ABS system:

Speed sensors
Pump
Valves
Controller
Speed SensorsThe anti-lock braking system needs some way of knowing when a wheel is about to lock up. The speed sensors, which are located at each wheel, or in some cases in the differential, provide this information.


Valves

There is a valve in the brake line of each brake controlled by the ABS. On some systems, the valve has three positions:
In position one, the valve is open; pressure from the master cylinder is passed right through to the brake.
In position two, the valve blocks the line, isolating that brake from the master cylinder. This prevents the pressure from rising further should the driver push the brake pedal harder.
In position three, the valve releases some of the pressure from the brake.
Pump

Since the valve is able to release pressure from the brakes, there has to be some way to put that pressure back. That is what the pump does; when a valve reduces the pressure in a line, the pump is there to get the pressure back up.
Controller

The controller is a computer in the car. It watches the speed sensors and controls the valves.
ABS at Work

There are many different variations and control algorithms for ABS systems. We will discuss how one of the simpler systems works.

The controller monitors the speed sensors at all times. It is looking for decelerations in the wheel that are out of the ordinary. Right before a wheel locks up, it will experience a rapid deceleration. If left unchecked, the wheel would stop much more quickly than any car could. It might take a car five seconds to stop from 60 mph (96.6 kph) under ideal conditions, but a wheel that locks up could stop spinning in less than a second.

The ABS controller knows that such a rapid deceleration is impossible, so it reduces the pressure to that brake until it sees an acceleration, then it increases the pressure until it sees the deceleration again. It can do this very quickly, before the tire can actually significantly change speed. The result is that the tire slows down at the same rate as the car, with the brakes keeping the tires very near the point at which they will start to lock up. This gives the system maximum braking power.

When the ABS system is in operation you will feel a pulsing in the brake pedal; this comes from the rapid opening and closing of the valves. Some ABS systems can cycle up to 15 times per second.

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