Brakes
We have many different brake products you can buy these online.
A brake is a device for slowing or stopping the motion of a machine or vehicle,
or alternatively a device to restrain it from starting to move again. The kinetic
energy lost by the moving part is usually translated to heat by friction. Alternatively,
in regenerative braking, much of the energy is recovered and stored in a flywheel,
capacitor or turned into alternating current by an alternator, then rectified and
stored in a battery for later use. Note that kinetic energy increases with the square
of the velocity (E = 1/2·m·v2 relationship). This means that if the speed of a vehicle
doubles, it has four times as much energy.
The brakes must therefore dissipate four times as much energy to stop it and consequently
the braking distance is four times as long. Brakes of some description are fitted
to most wheeled vehicles, including automobiles of all kinds, trucks, trains, motorcycles,
and bicycles. Baggage carts and shopping carts may have them for use on a moving
ramp. Some aeroplanes are fitted with wheel brakes on the undercarriage. Some aircraft
also feature air brakes designed to slow them down in flight. Notable examples include
gliders and some WWII-era fighter aircraft. These allow the aircraft to maintain
a safe speed in a steep descent. The Saab B 17 dive bomber used the deployed undercarriage
as an air brake.
Deceleration and avoiding acceleration when going downhill can also be achieved
by using a low gear; see engine braking. Friction brakes on cars store the heat
in the rotating part (drum brake or disc brake) during the brake application and
release it to the air gradually. Effects on noise pollution Brake lever on a horse-drawn
hearse Brake lever on a horse-drawn hearse Main article: Roadway noise The action
of braking for motor vehicles produces recognizable sound level emissions, varying
with the specific tire types and with the roadway surface type produces considerable
effect upon sound levels or noise pollution emanating from moving vehicles.There
is a considerable range in acoustical intensities produced depending upon the specific
tire tread design and the rapidity of deceleration required to slow the vehicle.
Modern airliner jets feature combined spoiler and airbrake controls. On landing,
the deployment of these spoilers causes a dramatic loss of lift and hence the weight
of the aircraft is transferred from the wings to the undercarriage, allowing the
wheels to be mechanically braked with much less chance of skidding. In addition,
the form drag created by the spoilers directly assists the braking effect. Reverse
thrust is also used to help slow the aircraft after landing.
Air brake's simplest form, called the straight air system, compressed air
pushes on a piston in a cylinder. The piston is connected through mechanical linkage
to brake shoes that can rub on the train wheels, using the resulting friction to
slow the train. The mechanical linkage can become quite elaborate, as it evenly
distributes force from one pressurized air cylinder to 8 or 12 wheels.
Disc brakes were most popular on sports cars when they were first introduced, since
these vehicles are more demanding about brake performance. Discs have now become
the more common form in most passenger vehicles, although many (particularly light
weight vehicles) use drum brakes on the rear wheels to keep costs and weight down
as well as to simplify the provisions for a parking brake. As the front brakes perform
most of the braking effort, this can be a reasonable compromise.
Volkswagen Adaptive Cruise Control represents an extension of the familiar cruise
control system with the addition of a radar sensor. The activated system maintains
a preset distance to the vehicle ahead and adjusts driving speed automatically.
In this way, Adaptive Cruise Control makes the driver’s task considerably easier
and more convenient.
The heart of the Adaptive Cruise Control system is a radar sensor with a mapping
range of up to 200 metres and a horizontal opening angle of 12 degrees. The radar
sensor and the control unit form a unit and are located, on the new Passat for example,
behind the Volkswagen brand emblem in the radiator grille. The advantage of radar
technology is that it functions reliably in all weather and road conditions. The
heart of the Adaptive Cruise Control system is a radar sensor with a mapping range
of up to 200 metres and a horizontal opening angle of 12 degrees. The radar sensor
and the control unit form a unit and are located, on the new Passat for example,
behind the Volkswagen brand emblem in the radiator grille. The advantage of radar
technology is that it functions reliably in all weather and road conditions.
Based on the radar sensor’s signals, the control unit calculates not only the distance
to the vehicle ahead, but also the relative speed of both vehicles and – if there
is more than one lane – the laterally offset position of the vehicle ahead. If there
are several vehicles simultaneously in the sensor’s range, the vehicle that is to
serve as the basis for the system’s calculations is selected from this information.
Stationary objects, e.g. the end of a traffic jam or crash barriers, however, cannot
be perceived by the radar sensor. Based on the radar sensor’s signals, the control
unit calculates not only the distance to the vehicle ahead, but also the relative
speed of both vehicles and – if there is more than one lane – the laterally offset
position of the vehicle ahead. If there are several vehicles simultaneously in the
sensor’s range, the vehicle that is to serve as the basis for the system’s calculations
is selected from this information. Stationary objects, e.g. the end of a traffic
jam or crash barriers, however, cannot be perceived by the radar sensor.
When approaching a vehicle ahead that is moving more slowly or cutting in, the Adaptive
Cruise Control system intervenes in the engine management and, if necessary, in
the brake system. If the necessary deceleration exceeds 30 percent of the maximum
deceleration, visual and acoustic warning signals instruct the driver to operate
the brakes. When approaching a vehicle ahead that is moving more slowly or cutting
in, the Adaptive Cruise Control system intervenes in the engine management and,
if necessary, in the brake system. If the necessary deceleration exceeds 30 percent
of the maximum deceleration, visual and acoustic warning signals instruct the driver
to operate the brakes.
Mercedes-Benz S-class luxury vehicle, the first passenger car equipped with a technology
called adaptive cruise control. The technology makes these adjustments even though
you haven't touch the brake or gas pedal. At a safe distance behind, your Mercedes
settles to a speed matching that of the driver in front of you. That's too slow,
so after a look in your rearview mirror you pull into the empty outside lane and
feel the acceleration as your car speeds up to the pre-set cruising speed. You still
haven't press the accelerator pedal.
|