MECHANICAL ENGINEERING

Piston is reciprocating part in IC Engine.It's function is to transfer the pressure energy which is generated due to combustion to coneecting rod.Depression is provide in piston head if engine has valves.At the end of compression stroke both inlet as well as exhaust valve is closed but during exhaust stroke exhaust valve remains open untill the piston reaches the top dead cenre.During suction stroke inlet valve opens after top dead center.In IC engine to achieve a good efficiency high compression ratio is required.To maintain high compression ratio, very less space is left on the top of the piston when it is on the top dead centre.                                              so when valve is open they can hit with the piston.To avoid this we provide depression on piston.By doing so clearnce is minimized and piston valve interference is also eliminated. Manufacturer has to consider this during design and manufacturing of piston.

(1) Shaper is used for small job  whileplaner  work with large size of work piece. (2) Tool is the moving part in shaper machine while  Work piece is the moving part in planer. (3) Work piece remain stationary on this machine in shaper while t ool remains stationary in planer. (4)shaper is light duty machine while planner is heavy duty. (5)Shaper  uses single point cutting tool while planner uses multipoint cutting tool. (6)Shaper uses quick return mechanism while planner is driven by gear or hydraulic arrangement. (7)shaper has poor accuracy while planer has high accuracy.

Brake fluid is a type of hydraulic fluid used in hydraulic brake and hydraulic clutch applications in automobiles, motorcycles, light trucks, and some bicycles. It is used to transfer force into pressure, and to amplify braking force. It works because liquids are not appreciably compressible.                            CHARACTERISTICS OF BRAKE FLUID (1)Low Compressibility: Brake liquids must maintain low level of compressibility when temperatures and pressure changes. (2)HIgh boiling point:Boiling point should be high so that it doesn't boil during it's operation (3)Low freezing point:For dependable, predictable stopping mechanism operation, brake liquid must keep up a consistent thickness under an extensive variety of temperatures, including compelling chilly. (4)Anti corosion:Additives are added to make it corosion resistant.               TYPES OF BRAKE FLUID COMMONLY AVAILABLE 1)DOT 3 2)DOT 4 3)DOT 5 DOT 3 and DOT 4 are glycol based

NEED OF SUSPENSION IN TRACTOR Tractors other heavy commercial vehicles do not have suspension because of the following reasons: (1)While moving tractor is supposed to maintain a constant height for ploughing and digging.If there is a suspension system then it will oscillate in the direction of suspension.Thus it will be unable to maintain a constant depth. (2)Due to Suspension offroad stability is less. (3)While ploughing  there will be load trying to make the tractor stop as its inserted in the ground. This may cause the body of the tractor to tilt backwards   Note:   As the speed of the tractor is less and the tyres big(which absorbs more shocks),the need of suspension is felt less.