Operation of the car

This page describes the general operation of a Automobile , 2007, as well as different Organe S and components of this one.

A car is consisted of the following elements:

the Roue S which support and allow the mobility of the vehicle;
the Frame and the Carrosserie constitute a Habitacle provided with Siège S;
the suspensions: carry out the elastic connection between the frame and the wheels ;
the brake or Frein S ensures the deceleration and the stopping of the vehicle;
the Internal combustion engine and/or the electric motor S propel the vehicle;
the Organe S of transmission transmit the Couple driving to the wheels ;
instruments of controls and the orders (Stealing, Pedal S, Meter S, Gauge, Speed regulator…) allow the control of the car;
the tank of energy: tank of Fuel and/or the batteries give a certain autonomy to the vehicle;
the elements of Comfort and Sécurité are additional of number always growing.

Operation

Engine…

The function of the engine is to produce a force able to put moving the vehicle. See: Leitartikeces on the Driving S.

… thermal

the Internal combustion engine (called also wrongly in current language “spark-ignition Engine”) consumes a Carburant which is mixed with Air and rejects Gaz residues of combustion. Its output although being improving is always quite weak - about 15 with 20 %.
It also produces many Chaleur, which is evacuated in the surrounding air through exchanging S air/water, air/oil called Radiateur S.
a Muffler is used to reduce the sound level engine as well as the polluting emissions (Gaz and particle S) to a level in conformity with the Norme S in force.
the liquid fuel is brought tank in the engine by a electric Pompe through a drain and of a filter. When the fuel is gas, this one arrives at the engine through a Détendeur.
the engine involves, inter alia accessories, a Alternateur in charge of the electrical production low tension. This one supplies all the electric accessories of the vehicle, it reloads in parallel a battery, providing the electrical energy at the time of the shutdown.
It generates a circular motion or couple on its Arbre of exit.

… electric

The electrical motors draw their energy in accumulating S special for traction assembled out of battery.

During the phases of Accélération the engines transform electrical energy into work and, during the Freinage S transform the force of Inertie vehicle in electrical energy reloading the batteries. A bidirectional system of Régulation connects the engines to the batteries.
Of the alternatives under development uses a system of Combustible battery to provide electrical energy. These assemblies allow in theory an operation quiet, less pollutant and enough flexible to replace the spark-ignition engines in the long term.

… mixed or hybrid

The hybrid motorizations combine the advantages of the thermal engines and those of the electrical motors.

the two types of engines are assembled on the vehicle, a data-processing system embarked combined with an electronic of power manages the complementarity of the engines, as well as the Ressource S available according to the requests and of the constraints.
This type of motorization while being more complex to conceive and manufacture is particularly ecological (in theory) compared to the systems traditional thermics or electric. It only allows in particular a rejection of CO definitely lower than that of a thermal engine.
the most obvious advantage is the not pollution by exhaust fumes of the places where these rejections are the least desirable, the Ville S, since the thermal engine functions only starting from one certain speed, with less of course than the batteries are discharged.

See: Hybrid vehicle

Transmission

Gear box

The gear box is the body which makes it possible to modify the speed of a car even if the number of revolutions of the engine is constant and especially, in the case of the spark-ignition engine, to adapt the engine torque available to the needs. A gear box is an assembly of mobile and fixed pinions on axes, locked up in a tight Carter and lubricated by Barbotage, or under Pression. This system makes it possible to modify the essential report/ratio of reduction between the wheels and the engine, the spark-ignition engines not having a sufficient couple available to all the modes of rotation.

The ratio of reduction gearing indicates the relation between the number of revolutions of the engine and that of the wheels motrices
This gear box can be manual, robotized, automatic or with variation continues:

the manual gear box often comprises five to six reports/ratios goes from there front, (the fashion is with seven ), plus a step back.
Certains cross-country vehicles has an additional gear box (limps of transfer), offering a range of shorter reports/ratios intended for the evolutions in cross-country. This type of box imposes a rupture of traction on the change in short and long reports/ratios.
a box Robot ized is a manual box actuated by Moteur S or Actuateur S: Hydraulique S or electrotechnical S. the changes of report/ratio is ordered by the driver or is managed by a electronic Automate.
an automatic box offers an additional comfort, it does not impose an interruption of traction to change report/ratio. Management is entrusted to a electronic automat with the service of hydraulics.

a hydraulic Torque converter placed between the engine with the box, increases the couple available to low mode and filter the jolts.
the converter, as well as the automatic box, involves a light overconsumption for a considerable comfort of control.

a box with continuous variation (CVT) consists of a Courroie connecting two Poulie S: a driving side, a differential side, whose Diamètre S vary automatically adapting the couple provides by the engine to the request.

It offers an infinity of reports/ratios without jolts, nor rupture of the propulsion and a constant adaptation between the mode of rotation of the engine and its instantaneous load.
In spite of a mechanical output still slightly lower (but in progression) than that of a pinion box, the average consumption of fuel of road use approaches that of a mechanical box with a comfort of incomparable control.

Pont, differential and Cardan joint

A bridge (often in the same case as the gear box on front tractions) makes it possible to transmit the movement to the two wheels of the same axle. The bridge is connected to the wheels by two Arbre S or half transmissions provided with Cardan joint S.

A Différentiel is integrated into the bridge, it allows the difference in number of revolutions between the left and right wheel in the curves. Without this device, it would be very difficult to take a turn without rolling to the step. On the vehicles intended for the whole ground a blocking system differentials authorizes traction under conditions of null adherence of one or several wheels.

Traction

On a traction, the couple of the engine is transmitted to the nose gear wheels.

Propulsion

On a propulsion, in fact the aft wheels receive the engine torque. If the engine is not located at the back, the movement is transmitted thanks to a driveshaft. The bridge is positioned between the aft wheels.

4x4

On a vehicle with integral transmission the two systems coexist, in order to offer especially the maximum of motricity in any ground. On certain implementations, the tree connecting the axles before and back east provides with a differential making it possible to dynamically distribute the couple between these axles.

Braking

Deceleration

There exist three manners of slowing down a car:

the use of the driving brake which consists in changing report/ratio on the gear box, so as to put the engine at a mode where, being fed more while carburizing, it offers an unquestionable resistance;
a support on the Pédale of Frein starts the operation of the brakes;
a vehicle can be immobilized using the Brake hand. The handbrake lever to hand draws on a cable operating the brakes before or more often back, by a specific mechanism.

The principal brakes are most of the time with order Hydraulique, but start to appear the electric drives (very rare to date).

the brake pedals actuates an amplifier which pushes a Piston in a Cylindre fills up of a special Huile.
oil under pressure leaves the cylinder in direction of two cross circuits; one orders the nose gear wheel left and the right aft wheel, the other order the nose gear wheel right-hand side and the left aft wheel. This system preserves a minimum of braking balanced in the event of failure of one of the two circuits.
the brakes assembled on the wheels receive the water pressure and tighten fixed parts against the moving parts.
the part fixed called trimmings or plates are out of special material wearing gradually, resistant to the rise in temperature and ensuring a good mechanical contact.
the moving parts turning with the wheels are out of reinforced metal because they must dissipate all thermal energy resulting from the kinetic loss of energy of the vehicle.

In the case of a disc, the plates are tight on the two faces of the disc by one or more hydraulic pistons. The disc is autoventilé on the vehicles requesting the brakes hard.
With a drum, the trimmings are forced against the interior face of the drum by a double hydraulic piston.
the system ABS ( Antiblockiersystem ) removes blockings of wheel during brakings violent one and in condition of low adherence. He slackens the pressure in the brake system of a wheel as of the detection a number of revolutions lower than that of the other wheels. This device makes it possible the driver to keep the directional control of its vehicle, braking being then slightly attenuated.
the system Aide with emergency braking ( AFU ) makes it possible to slow down with the maximum power as of the first moments of an emergency braking, detected according to the speed of depression of the brake pedals. It is necessarily associated with a ABS .
the system ESP makes it possible to appreciably correct the trajectory while acting at the same time on the brake and the control of the engine output.

Brake of park

The system is made up: From a lever often with hand, sometimes from an additional pedal, this lever draws on a cable, which itself mechanically actuates the wheel braking system of the same axle very often the back and sometimes the front one.

Contact with the ground

The wheels are four, plus a not assembled spare wheel. The latter is sometimes replaced by an anti-puncture kit or, by a wheel equipped with a reduced tire, ( wafer allowing to roll at moderate speed to the next garage), for reasons for obstruction.

Each wheel is formed of the assembly of a pneumatic assembled on a Jante. This unit forms a tight space, which is inflated, (fills up under pressure) Air and sometimes of Azote (for a less loss).
the tires play a very important part, because they alone ensure the contact between the ground and the vehicle, whatever the circumstances. For this reason, it is important to maintain the tires in good state and, with a pressure of adapted inflation. It is advised to check the pressure of the whole of the wheels, spare wheel included/understood, approximately every month; inflation with nitrogen makes it possible to lengthen the periodicity of the checking, but does not remove it to in no case.

Suspensions

A system of arms, associated with one or more Spring S coupled to a hydraulic Shock absorber, constitutes an elastic connection between each wheel and the frame of the véhicule.
This mechanical assembly is of very variable design according to the models and of the manufacturers. Some use complex and electronically assisted hydropneumatic systems. But the cost of such a suspension is such as it is reserved for the top-of-the-range vehicles.

There exist two principal types of suspension S:

Independent: each wheel can carry out movements without influencing the other wheel of the same axle. It is the type of suspension more used for the particular vehicles. It is comfortable and offers a good handling.
Rigid: The wheels of same axles are dependant in a rigid way, the movements of the influential one on the other. This type of suspensions is used for the heavy trucks because it makes it possible to support heavy loads. The rigid axles are still used on the cross-country vehicles for their robustness.

Particular case: on the vehicles recent heavy trucks, the cabin itself is suspended compared to the frame.

Orders

Direction

The system which makes it possible to direct a car is composed of several parts:

the control device, which is generally flying a circular, makes it possible the hands of the driver to apply a couple to the system of direction. The wheel, located vis-a-vis the driver, is in general adjustable as well as possible to adapt to the morphology and the practices of the drivers.
When the car goes in straight line the nose gear wheels are on the same axis parallel with that of the aft wheels but at the time of a turn the nose gear wheels are not parallel any more because their axes and that of the aft wheels must be Concourant S.
the transmission of the movement printed by the driver is done on the steering column fixed at the center of the wheel of order; it transmits the couple to the rods of direction (acting directly on the wheels) via a steering gear box.
the case is either a system pinion being geared on a toothed rack, or a system with screw with circulation of balls.
the assistance of the direction makes it possible the driver not to have to provide significant effort on the wheel. It is generally autoadaptive by more or less amplifying the forces printed at the wheel with the required efforts to direct the vehicle. These effort are naturally variable and inversely proportional to the speed of the vehicle.

the assistance is traditionally hydraulic. It is generally controlled at the speed, in order to increase stability at high-speed, without penalizing the handiness at low speed.
It can from now on be electric. The assistance by Electrical motor more economic, is seen that it is inactive in straight line, whereas a hydraulic system must always be under pressure.

Pedals

From left to right:

the pedal clutch , (presents only on the vehicles to manual box), allows the change of report/ratio in the gear box by disconnecting the latter of the engine, inducing a rupture of traction;
the brake pedals transmits to the brake a pressure proportional to the pressure exerted on this pedal;
the accelerator pedal makes it possible to control the power requested from the engine.

Electric drive

The driver has various orders gathered around the wheel, enabling him not to leave eyes the road and hands the volant.
The provision of these orders is not standardized, but the French manufacturers adopted the same provision with little thing near:

On the left:

One finds a lever with several positions to control the lighting and external indication (the startup of lighting is sometimes ordered by a button with rocker on the instrument panel).

On the right:

a lever allows the order of the windshield wiper S before and back.
Often, in withdrawal, a case with multiple orders makes it possible to control the Autoradio.

the sound signalling hooter is actuated while supporting in end of one of the levers or on the center of the wheel (according to the model of the vehicle).

Bill-posters

Under a cap integrated into the instrument panel (protecting the windshield from the luminous reflections), generally opposite the driver and, sometimes in the center of the Instrument panel, but turned towards the driver

a Speedometer of the vehicle, obligatory, comprises a meter or Odomètre, not réinitialisable, adding up Kilomètre S traversed by the vehicle, as well as a meter with restoring for a daily use.

a level gauge of fuel.
Of the luminous witnesses is laid out, under the same cap, recalling to the driver certain events: lighting of the night lights, codes, headlights, indicators and lighting and additional street signs.
Of the indicators of alarm: defect of oil pressure, excessive water temperature, defect of load of the battery and, indicator of operation of various accessories, are gathered in same space.
a Compte-tours indicating the number of rotations of the engine per minute is often present. It comprises a zone delimited in red indicating the number of revolutions of the engine not to be exceeded.
a Pendule makes it possible to effectively fill a vacuum in space of the instrument panel.
Various indicators: oil temperature, water temperature, temperature of air, oil pressure, pressure the turbo one, Voltmeter, Ampèremètre can be added.

Safety

Protection of the passengers in the event of shock

Zones of deformation and cell of survival

The modern vehicles are designed so that a shock is deadened by the deformation of the peripheral zones (engine cowling, trunk, sides), to preserve the integrity of the cockpit which profits to him from a reinforced structure. On the level of the structure, parts are dimensioned to become deformed. In the event of frontal shock, the efforts will pass by the members on the one hand, the sides of case and the floor. For a side shock, the ways of effort are the foot medium, the floor and the house. In all the cases, one tries to make pass the shock by the " three ways of efforts".

Airbag

The Airbag or cushion of safety starts starting from a certain force of Décélération and a certain speed to limit the shock undergone by the occupants of the vehicle, by distributing it over a greater period of time (power of the shock being function of the reduction speed and the time necessary to decrease this speed). It can save lives until approximately 50 km/h at the time of the impact on a fixed obstacle.

Safety belt

The safety belt makes it possible to maintain the occupying one of a moving traffic on its seat at the time of a shock. It avoids its ejection out of the vehicle or its projection against part of the cockpit (instrument panel, windshield, etc). Equipped with a Prétensionneur and a Effort limiter, it makes it possible like the Airbag to minimize the power of the shock, by transferring energy from the shock in the fasteners of the belt.

Lighting and external street signs

Night lights or Side-lights to the four corners of the vehicle, (in Europe: before: White /back: Red )
Headlights dipped and the Main-beam headlamps ( white )
Fires stop , positioned with the back, lit at the time of a support on the brake pedals. ( red )
Fire (X) of retreat , positioned (S) with the back, lit (S) at the time of the passage of step back. ( white )
Feux Flickering S positioned to the four corner of the vehicle is used to indicate the changes of management of the vehicle to the other road users. ( orange )
Hazard warning lights is used to announce a danger, (abnormally stopped vehicle or circulating at abnormal speed). Flashing lights on the two sides at the same time. ( orange )
Indicating of gauge , lit permanently, they make more visible the vehicle in many environments. ( orange )
Front fog lamps is used to improve the visibility of the driver per time of fog. ( white )
Feu (X) of fog postpones improves (NT) per time of fog indication of the vehicle for the other users arriving by the back. ( red )

Sound signalling hooter

The motor vehicles are obligatorily equipped with a sound signalling Hooter, making it possible the driver to warn of a danger the people external with the vehicle.
It is of a regulated use, particularly in Agglomération.

Rear view mirrors

The rear view mirrors are accessories essential to the control of a car. They consist of a directional mirror making it possible the driver to see behind him without being turned over.

Interior rear view mirror

Generally placed in top of the windshield and median position vis-a-vis the driver, it makes it possible the driver to visualize what occurs behind its vehicle. This rear view mirror comprises two positions: for the day and, for the night, there a second mirror placed behind a Miroir without silvering allows to limit the dazzling by the prosecuting vehicles.

External rear view mirrors

The external rear view mirrors involve an overconsumption of approximately 3 % because of aerodynamic turbulences which they generate. Their replacement by a couple camera-screen is not authorized by the current technical standards.

Windshield wiper

The windshield wipers (also called essuie-panes) are rubber scrapers, assembled on arms actuated by a Electrical motor ordered since the cockpit, the arms plate the brushes with certain pressure on the Pare-brise.

They are of variable number, according to the size of the windshield and the design of their arms. They make it possible to clean the front windshield, as well as the rear window, without leaving the véhicule.
They are obligatorily associated with a lava freezes, electric Pompe, projecting water drawn from a tank, in order to help with the cleaning of surfaces glazed.

Automobile comfort

The principal elements of comfort are:

Car radio
Heating and air-conditioning manual/automatic
Toit opening
Raises pane electrically (electric or manual)
Allume Speed regulator cigar
automobile leather, adjustable and heating
Sellerie

Coffre with luggage

perfumery

See too

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