Hydraulic Copying Attachment

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Hydraulic copying attachment

The mounting and working principle of hydraulic copying attachment for profileturning in centre lathe are schematically shown in Fig. 4.6.3. Here also, the stylus

moves along the template profile to replicate it on the job. In mechanical system (Fig.4.6.2) the heavy cutting force is transmitted at the tip of the stylus, which causesvibration, large friction and faster wear and tear. Such problems are almost absent inhydraulic copying, where the stylus works simply as a valve – spool against a lightspring and is not affected by the cutting force.

Hydraulic copying attachment is costlier than the mechanical type but works muchsmoothly and accurately. The cutting tool is rigidly fixed on the cross slide which alsoacts as a valve – cum – cylinder as shown. So long the stylus remains on a straightedge parallel to the lathe bed, the cylinder does not move transversely and the toolcauses straight turning. As soon as the stylus starts moving along a slope or profile,

i.e., in cross feed direction the ports open and the cylinder starts moving accordinglyagainst the piston fixed on the saddle. Again the movement of the cylinder i.e., theslide holding the tool, by same amount travelled by the stylus, and closes the ports.Repeating of such quick incremental movements of the tool, Äx and Äy result in the

profile with little surface roughness.

Adaptive Control System:





Hydraulic Amplifier:



Schematic View

Spool Valve Up



Spool Valve Down

Positional Servomechanism

-Closed loop control whose output is some mechanical position or velocity set by areference input- The reference input is the required output- Positional controllers include

1. antenna rotator systems2,rudder control in ships3. flap control in aircrafts4. Speed controllers include5. idle speed control of motor vehicle6. cruise control

We shall only consider the dc electromechanical servo, i.e. one where the actuator is adc motor. Other actuators are possible such as hydraulic actuator andPneumatic actuators.

A typical schematic representation of the dc servomechanism is shown in the figure below:



Scrub Radius:

Scrub radius is also known as steering offset, and scrub geometry. It is the distance between 2imaginary points on the road surface - the point of center contact between the road surface and the tire,and the point where the steering-axis center-line contacts the road surface.



• If these two points intersect at the center of the tire, at the road surface, then the scrub radius

is zero.

• If they intersect below the road surface, scrub radius is positive.

• If they intersect above the road surface, scrub radius is negative.

The effect of scrub radius - positive or negative - is to provide a turning moment which attempts to turn

the wheel away from the central position, when the vehicle is in motion.

On a rear-wheel-drive vehicle with positive scrub radius, the vehicle’s forward motion and the frictionbetween the tire and the road causes a force which tends to move the front wheels back. This wouldcause the wheels to toe-out.

If it has negative scrub radius, the front wheels again tend to move back, but this time, they toe-in.

On front-wheel-drive vehicles, the opposite occurs. Positive scrub radius causes toe-in, and negativecauses toe-out.

During braking, on any type of drive, if braking effort is greater on one side of the vehicle than theother, positive scrub radius will cause the vehicle to veer towards the side with the greater effort.

Negative scrub radius will cause the vehicle to veer away from the side of greatest effort. How much itveers depends on the size of the scrub radius.

This is why, vehicles with a diagonal-split brake system have negative scrub radius built into thesteering geometry. If one half of the brake system fails, then the vehicle will tend to pull up in a straightline.

Since the offset of the wheel rim determines where the centerline of the tire meets the road surface, itis important that the offset is not changed if wheels are being replaced.

Changing the rim offset changes the scrub radius, and also the predictability of the vehicle handling, if brakes should fail.





Clutch Plates Type:

Drive (friction) plate: The friction plate is ring shaped and coated with fiber. It

is a wear and tear part of clutch assembly. The friction plate surfaces interface

between the clutch basket tangs (gaps) and pressure plate. It has teethes on the

outside surfaces. These teethes fix on the cuto uts between clutch hub tangs

(gaps). It is coated with the same material as you see in brake pad (shoe).

Driven (steel) plate: It is ring shaped and made of steel and sometime of

aluminum. The surfaces of steel or aluminum plate interfaces between pressure

plate and clutch hub. It has teethes on inside surfaces. This teethes are fix on the

cut outs of clutch hub. Mostly steel plates are used in clutch assembly due to their



durability. The aluminum plates are used in Moto GP due to their lighter weight.

These plates are worn out very fast compare to steel plate.

Pressure Plate: It is the moving part of the clutch assembly which works

against clutch spring tension. It releases the clamping action on the clutch plates when the clutch lever is engaged.

Gear Box











Hydro pneumatic Suspension:

The purpose of this system is to provide a sensitive, dynamic and high-capacitysuspension that offers superior ride quality. A nitrogen reservoir with variable volumeyields a spring with non-linear force-deflection characteristics. In this way the

resulting system does not possess any eigen frequencies and associated dynamicinstabilities, which need to be suppressed through extensive damping in conventionalsuspension systems. The actuation of the nitrogen spring reservoir is performedthrough an incompressible hydraulic fluid inside a suspension cylinder. By adjustingthe filled fluid volume within the cylinder, a leveling functionality is implemented.The nitrogen gas within the suspension sphere is separated from the hydraulic oilthrough a rubber membrane.

This system uses a belt or camshaft driven pump from the engine to pressurise aspecial hydraulic fluid, which then powers the brakes, suspension and power steering.It can also power any number of features such as the clutch, turning headlamps and

even power windows. The suspension system usually features driver-variable rideheight, to provide extra clearance in rough terrain.

http://en.wikipedia.org/wiki/Ride_quality

http://en.wikipedia.org/wiki/Eigenfrequency#Vibration_analysis


http://en.wikipedia.org/wiki/Brake


http://en.wikipedia.org/wiki/Suspension_(vehicle)

http://en.wikipedia.org/wiki/Power_steering

http://en.wikipedia.org/wiki/Clutch


http://en.wikipedia.org/wiki/Citro%C3%ABn_DS


http://en.wikipedia.org/wiki/Power_windows

http://en.wikipedia.org/wiki/Height_adjustable_suspension

http://en.wikipedia.org/wiki/Ride_height



http://en.wikipedia.org/wiki/Ride_quality



http://en.wikipedia.org/wiki/Suspension_(vehicle)

http://en.wikipedia.org/wiki/Power_steering



http://en.wikipedia.org/wiki/Power_windows

http://en.wikipedia.org/wiki/Height_adjustable_suspension





There have been many improvements to this system over the years, including variableride firmness (Hydractive) and active control of body roll (Citroën Activa). The latestincarnation features a simplified single pump-accumulator sphere combination. Automanufacturers are still trying to catch up with the combination of features offered bythis 1954 suspension system, typically by adding layers of complexity to an ordinary

steel spring mechanical system.

At the heart of the system, acting as pressure sink as well as suspension elements, arethe so called spheres, five or six in all; one per wheel and one main accumulator aswell as a dedicated brake accumulator on some models. On later cars fitted withHydractive or Activa suspension, there may be as many as ten spheres. Spheresconsist of a hollow metal ball, open to the bottom, with a flexible desmopan rubber membrane, fixed at the 'equator' inside, separating top and bottom. The top is filledwith nitrogen at high pressure, up to 75 bar , the bottom connects to the car's hydraulic

fluid circuit. The high pressure pump, powered by the engine, pressurizes thehydraulic fluid (LHM) and an accumulator sphere maintains a reserve of hydraulic power. This part of the circuit is at between 150 and 180 bars. It powers the front brakes first, prioritised via a security valve, and depending on type of vehicle, can power the steering, clutch, gear selector, etc.

Pressure flows from the hydraulic circuit to the suspension cylinders, pressurizing the bottom part of the spheres and suspension cylinders. Suspension works by means of a piston forcing LHM into the sphere, compacting the nitrogen in the upper part of thesphere; damping is provided by a two-way 'leaf valve' in the opening of the sphere.LHM has to squeeze back and forth through this valve which causes resistance and

controls the suspension movements. It is the simplest damper and one of the mostefficient. Ride height correction (self levelling) is achieved by height corrector valvesconnected to the anti-roll bar, front and rear. When the car is too low, the heightcorrector valve opens to allow more fluid into the suspension cylinder (e.g., the car isloaded). When the car is too high (e.g. after unloading) fluid is returned to the systemreservoir via low-pressure return lines. Height correctors act with some delay in order not to correct regular suspension movements. The rear brakes are powered from therear suspension circuit. Because the pressure there is proportional to the load, so is the

braking power.

http://en.wikipedia.org/wiki/Hydractive

http://en.wikipedia.org/wiki/Citro%C3%ABn_Activa

http://en.wikipedia.org/wiki/Nitrogen

http://en.wikipedia.org/wiki/Bar_(unit)

http://en.wikipedia.org/wiki/Hydraulic_accumulator

http://en.wikipedia.org/wiki/Hydractive

http://en.wikipedia.org/wiki/Citro%C3%ABn_Activa

http://en.wikipedia.org/wiki/Nitrogen

http://en.wikipedia.org/wiki/Bar_(unit)

http://en.wikipedia.org/wiki/Hydraulic_accumulator



Rubber suspension

Rubber can be used as the suspension medium as well as for mountings andpivots. Its main advantage is that for sm a l l wh ee l mov em e n ts theri de is fai rl y so ft but it becomes harder as wheel movement

increases. It has the advantage of being small, light and compact,and wi l l absorb some of the energy passed to i t , unl ike a coi l

spring, which gives out almost as much energy as it re ce iv es .T he ru bber spr i n g i s a l so c ommon ly u sed on LGV s an d

trai le rs . A rubber susp ension unit i s shown in Fig .



Clutch Troubleshooting

Brakes Troubleshooting



Gear Box



Final Drive:



Brakes





LPG

Dashboard Instruments

A dashboard (also called dash, instrument panel, or fascia) is a control panel placed in

front of the driver of an automobile, housing instrumentation and controls for operation of the

vehicle.

The word originally applied to a barrier of wood or leather fixed at the front of a horse-

drawn carriage or sleigh to protect the driver from mud or other debris "dashed" (thrown) up

by the wheels and horses' hooves.

Dashboard Items:

Items located on the dashboard at first included the steering wheel and the instrument cluster.

The instrument cluster pictured to the right contains gauges such as

a speedometer , tachometer , odometer and fuel gauge, and indicators such as gearshift

position, seat belt warning light, parking-brake-engagement warning light [2] and an engine-

malfunction light. There may also be indicators for low fuel, low oil pressure, low tire pressure

and faults in the airbag (SRS) system. Heating and ventilation controls and vents, lighting

controls, audio equipment and automotive navigation systems are also mounted on the

dashboard.

The top of a dashboard may contain vents for the heating and air conditioning system and

speakers for an audio system. A glove compartment is commonly located on the passenger's

http://en.wikipedia.org/wiki/Automobile



http://en.wikipedia.org/wiki/Carriage#Body


http://en.wikipedia.org/wiki/Sled

http://en.wikipedia.org/wiki/Steering_wheel


http://en.wikipedia.org/wiki/Speedometer


http://en.wikipedia.org/wiki/Tachometer


http://en.wikipedia.org/wiki/Odometer

http://en.wikipedia.org/wiki/Fuel_gauge



http://en.wikipedia.org/wiki/Dashboard#cite_note-1

http://en.wikipedia.org/wiki/Automotive_navigation_system


http://en.wikipedia.org/wiki/Glove_compartment




http://en.wikipedia.org/wiki/Sled




http://en.wikipedia.org/wiki/Odometer







side. There may also be an ashtray and a cigarette lighter which can provide a power outlet

for other low-voltage appliances

Padding and safety

Padded dashboards were advocated in the 1940s by car safety pioneer Claire L. Straith.[4]

One of the safety enhancements of the 1970s was the widespread adoption of padded

dashboards. The padding is commonly polyurethane foam, while the surface is commonly

either polyvinyl chloride (PVC) or leather in the case of luxury models.

In the early and mid 1990s, airbags became a common feature of steering wheels and

dashboards.

Fashion In Instrumentation

In the 1940s through the 1960s, American car manufacturers and their imitators designed

unusually-shaped instruments on a dashboard laden with chrome and transparent plastic,

which could be less readable, but was often thought to be more stylish. Sunlight could cause

a bright glare on the chrome, particularly for a convertible.

With the coming of the LED in consumer electronics, some manufacturers used instruments

with digital readouts to make their cars appear more up to date, but this has faded from

practice. Some cars use a head-up display to project the speed of the car onto the

windscreen in imitation of fighter aircraft, but in a far less complex display.

Manufacturers such as BMW and Mercedes-Benz have included fuel-economy gauges in

some instrument clusters, showing fuel mileage in real time. The ammeter was the gauge of

choice for monitoring the state of the charging system until the 1970s. Later it was replacedby the voltmeter . Many vehicles have warning lights instead of voltmeters or oil pressure

gauges in their dashboard instrument clusters.

http://en.wikipedia.org/wiki/Automobile_safety

http://en.wikipedia.org/wiki/Claire_L._Straith




http://en.wikipedia.org/wiki/Polyurethane



http://en.wikipedia.org/wiki/Foam


http://en.wikipedia.org/wiki/Polyvinyl_chloride

http://en.wikipedia.org/wiki/Airbag



http://en.wikipedia.org/wiki/Light-emitting_diode

http://en.wikipedia.org/wiki/Head-up_display


http://en.wikipedia.org/wiki/BMW


http://en.wikipedia.org/wiki/Mercedes-Benz

http://en.wikipedia.org/wiki/Ammeter

http://en.wikipedia.org/wiki/Voltmeter


http://en.wikipedia.org/wiki/Automobile_safety





http://en.wikipedia.org/wiki/Polyvinyl_chloride


http://en.wikipedia.org/wiki/Light-emitting_diode



http://en.wikipedia.org/wiki/Mercedes-Benz

http://en.wikipedia.org/wiki/Ammeter






Evaporative Cooling VS Refrigerative Cooling Continued

If you are someone particularly concerned about the environment, evaporative cooling is the way to go.Refrigerative airconditioning or cooling has far higher carbon dioxide emissions than an evaporativecooling system. By selecting an evaporative airconditioning system, you are saving money, stayinghealthy and saving the environment.

Refrigerative airconditioners or coolers can remove the moitsure from the air you breath in your home.This can lead to dry eyes and noses, and irritated skin, as well as the loss of indoor plants from lack of moisture. Evaporative cooling systems are ideal for anyone, any age and any condition - the air is fresh,moist and clean and will not harm you or your family in any way.

Sleeping and resting during the hot, dry or humid summer months can be a difficult task if your home ishot and bothered. Children and adults will not sleep at their best when in hot conditions, especially if there is a noisy refrigerative cooling unit buzzing in their ear all night long. Evaporative cooler units andsystems are extremely quiet during their operation - meaning that you receive fresh, cool air to your lungs whilst sleeping soundly. No more restless nights, and no more waking to sneezing and dryness!

Refrigerative cooling units must be placed in a particular location or room in your home, and often this isthe only room that is kept cool. Evaporative cooling is a ducted system, that delivers the fresh, cool air to every room in the house that is fitted with a duct. There is no big bulky unit inside your home, hangingoff a wall - simply a small overhead duct that blows a nice, cool and fresh breeze. In those horrible heatwaves, your family will no longer have to cram themselves into one room to keep cool - they can go totheir bedrooms or other locations to take part in regular daily activities.





MOST:

Maynard Operation Sequence Technique (MOST)[1] is a predetermined motion time

system that is used primarily in industrial settings to set the standard time in which a worker

should perform a task. To calculate this, a task is broken down into individual motion

elements, and each is assigned a numerical time value in units known as time measurement

units, or TMUs, where 100,000 TMUs is equivalent to 1 hour. All the motion element times are

then added together and any allowances are added, and the result is the standard time. It is

much easier to use form of the older and now less common Methods Time

Measurement technique, better known as MTM.

The most commonly used form of MOST is BasicMOST, which was released in Sweden in

1972 and in the United States in 1974. Two other variations were released in 1980, called

MiniMOST and MaxiMOST. The difference between the three is their level of focus—the

motions recorded in BasicMOST are on the level of tens of TMUs, while MiniMOST uses

individual TMUs and MaxiMOST uses hundreds of TMUs. This allows for a variety of

applications—MiniMOST is commonly used for short (less than about a minute), repetitive

cycles, and MaxiMOST for longer (more than several minutes), non-repetitive operations.

BasicMOST is in the position between them, and can be used accurately for operations

ranging from less than a minute to about ten minutes.

Another variation of MOST is known as AdminMOST. Originally developed and released

under the name ClericalMOST in the 1970s, it was recently updated to include modern

administrative tasks and renamed. It is on the same level of focus as BasicMOST.

http://en.wikipedia.org/wiki/Maynard_Operation_Sequence_Technique#cite_note-0

http://en.wikipedia.org/wiki/Predetermined_motion_time_system


http://en.wikipedia.org/wiki/Standard_time_(manufacturing)


http://en.wikipedia.org/wiki/Allowance


http://en.wikipedia.org/wiki/Methods-Time_Measurement


http://en.wikipedia.org/wiki/Sweden


http://en.wikipedia.org/wiki/United_States

http://en.wikipedia.org/wiki/Maynard_Operation_Sequence_Technique#cite_note-0








http://en.wikipedia.org/wiki/United_States



Hydraulic Copying Attachment

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