Slider Crank and Slotted Lever Quick return motion mechanism

Slider Crank and Slotted Lever Quick return motion mechanism

 

 

Injection molding

Injection molding :-

Injection molding is a manufacturing process for producing parts by injecting material into a mold. Injection molding can be performed with a host of materials, including metals, glasses, elastomers, confections, and most commonly thermoplastic and thermosetting polymers.

Material for the part is fed into a heated barrel, mixed, and forced into a mold cavity where it cools and hardens to the configuration of the cavity.

Injection molding is used to create many things such as wire spools, packaging, bottle caps, automotive dashboards, pocket combs, some musical instruments (and parts of them), one-piece chairs and small tables, storage containers, mechanical parts (including gears), and most other plastic products available today. Injection molding is the most common modern method of part manufacturing; it is ideal for producing high volumes of the same object.

Thermoelectrically operated fan using a candle

Thermoelectrically operated fan using a candle.

( Operate a fan with the candle during power cuts/ villages where there is no power!!)

Innovation at its best.

Honing

Honing :
Honing is an abrasive machining process that produces a precision surface on a metal workpiece by scrubbing an abrasive stone against it along a controlled path. Honing is primarily used to improve the geometric form of a surface, but may also improve the surface texture.
Typical applications are the finishing of cylinders for internal combustion engines, air bearing spindles and gears. There are many types of hones but all consist of one or more abrasive stones that are held under pressure against the surface they are working on.
In terms of sharpening knives, a honing steel does not actually hone knives, but simply realigns the metal along the edge.

Direct injection

Direct injection:-

With direct injection, the fuel is injected directly into the combustion chamber which is usually formed by a cavity in the piston crown.

This cavity is carefully shaped to promote air swirl and the direction of the injector nozzle ensures that rapid mixing of the fuel and air assists complete combustion.

Advantages - It is claimed that direct injection gives higher thermal efficiency with lower fuel consumption. This is bought about by the fact that no heat is lost or power wasted in pumping air through a restricted opening into the separate chamber or in discharging the gases from the chamber. This gives easier starting and generally this type of engine does not require a starting aid device, such as glow plugs.

Disadvantages - This kind of injection is prone to “diesel knock”.
 

Stress Concentration

A stress concentration (often called stress raisers or stress risers) is a location in an object where stress is concentrated. An object is strongest when force is evenly distributed over its area, so a reduction in area, e.g., caused by a crack, results in a localized increase in stress. A material can fail, via a propagating crack, when a concentrated stress exceeds the material's theoretical cohesive strength. The real fracture strength of a material is always lower than the theoretical value because most materials contain small cracks or contaminants (especially foreign particles) that concentrate stress. Fatigue cracks always start at stress raisers, so removing such defects increases the fatigue strength.

Heat Treatment

Heat Treatment:-

Heat Treatment is the controlled heating and cooling of metals to alter their physical and mechanical properties without changing the product shape. Heat treatment is sometimes done inadvertently due to manufacturing processes that either heat or cool the metal such as welding or forming.

Heat Treatment is often associated with increasing the strength of material, but it can also be used to alter certain manufacturability objectives such as improve machining, improve formability, restore ductility after a cold working operation.Thus it is a very enabling manufacturing process that can not only help other manufacturing process, but can also improve product performance by increasing strength or other desirable characteristics.

Traction control system

Traction control system :-

A traction control system (TCS), is typically (but not necessarily) a secondary function of the anti-lock braking system (ABS) on production motor vehicles, designed to prevent loss of traction of driven road wheels. When invoked it therefore enhances driver control as throttle input applied is mis-matched to road surface conditions (due to varying factors) being unable to manage applied torque.

Intervention consists of one or more of the following:

>Reduces or suppress spark sequence to one or more cylinders
>Reduce fuel supply to one or more cylinders
>Brake force applied at one or more wheels
>Close the throttle, if the vehicle is fitted with drive by wire throttle
>In turbo-charged vehicles, a boost control solenoid can be actuated to reduce boost and therefore engine power.

Scavenging

Scavenging-

It is the process of pushing exhaustedgas-charge out of the cylinder and drawing in a fresh draught of air or fuel/ air mixture for the next cycle. This process is essential in having a smooth-running internal combustion engine. If scavenging is incomplete, the following stroke will begin with a mix of exhaust fumes rather than clean air. This may be inadequate for proper combustion, leading to poor running conditions such as four-stroking. Scavenging is equally important for both two- and four-stroke engines. However it
is more difficult to achieve in two-stroke engines, owing to the proximity, or even overlap, of their induction and exhaust
strokes. Scavenging is also equally important to both petrol and diesel engines. Modifying the exhaust system, (i.e. modifying the exhaust gas velocity by changing exhaust tube diameters) can
detract from the "ideal" scavenging effects, and reduce fuel efficiency and power if not properly planned out and executed.

Working Principle of AIRBAG

Working Principle of AIRBAG

NEW SPLIT-CYCLE ENGINE DESIGN TO IMPROVE FUEL ECONOMY BY 50 PERCENT

NEW SPLIT-CYCLE ENGINE DESIGN TO IMPROVE FUEL ECONOMY BY 50 PERCENT :


Split cycle engines—engines that split the functions of a normal four-cycle piston into two separate but adjacent and complementary pistons—have never been able to match the efficiency and overall function of traditional internal combustion engines, but a new design could change all that. By tweaking the standard split-cycle design with new features like a compressed air tank that captures wasted energy from the system, the Scuderi Group claim not only to have matched the efficiency of the standard four-cycle engine, but to have far surpassed it.
The Scuderi Group’s design has drawn interest from nine major carmakers, the company says, but has yet to prove the technology in real world prototype tests. But in computer simulations that install a Scuderi engine in a 2004 Chevy Cavalier, the split-cycle engine shows to reduce fuel consumption by 25 to 36 percent, translating roughly to a 50 percent improvement in overall fuel economy.
 

 

REGENERATIVE BRAKING SYSTEM

REGENERATIVE BRAKING SYSTEM:

Technically, you could generate energy by burning brake pads, but automotive engineers have managed to come up with a way to use brakes to generate energy without going up in flames. The technology is called regenerative braking. At the most basic level, regenerative braking means re-capturing the kinetic energy of the vehicle's motion and turning it into another type of energy. Commonly, this is done by converting kinetic energy into electricity and recharging the car's battery with it.

Know how a TurboJet, TurboFan, TurboProp and a TurboShaft Works !

Know how a TurboJet, TurboFan, TurboProp and a TurboShaft Works !

The core purpose of all these different types is to produce Thrust. The differences lie in how the engines produce thrust or power.

* Turbojet engines produce thrust by accelerating air through the core of the engine and out the exhaust. All of the air that enters the engine passes through the engine. It moves a small volume of air at high velocities.

* Turbofan engines produce thrust primarily by driving a large fan in front of the engine. Most of the air that goes through the fan actually goes around the core of the engine, with only a small amount of thrust created by the air leaving the exhaust. The fan moves a large volume of air at lower velocities than the air coming out of the exhaust.

* Turboprop engines produce thrust by driving a propeller. Little or no thrust is derived from the exhaust of the engine. The propeller is in line with the core of the engine and creates thrust the way any propeller does.

* Turboshaft engines produce power by driving a shaft, typically giving power to a gear box in the aircraft/ship/machinery that is being powered that powers something other than a propeller (helicopter rotors, generator, etc). 

Resistance Spot Welding

Resistance Spot Welding:

In spot welding the weld is effected by the heat produced due to resistance to the flow of current through two or more overlapping work pieces held pressed together between the electrodes. This is the simplest form of resistance welding and does not pose any problem for welding sheets ranging u to 12.5 mm in thickness. The majority of spot welding is however done with metal pieces less than 6 mm thick.

WHEEL ALIGNMENT

WHEEL ALIGNMENT:

A wheel alignment consists of adjusting the angles of the wheels so that they are perpendicular to the ground and parallel to each other. The purpose of these adjustments is maximum tire life and a vehicle that

tracks straight and true when driving along a straight and level road.

Wheel alignment is very important to ensuring your tires do not wear prematurely. A proper alignment also means less wear and tear on steering/suspension components. When a vehicles alignment is out of manufacturer recommended specification, it can cause the vehicle to drift/float or pull in different directions. This can pro

ve to be unsafe for you and the vehicle. Improper wheel alignment creates excessive friction on the road surface leading to uneven tire wear and unnecessary stress on steering/suspension components. This excessive drag will also reduce fuel economy.
 

Casting

Casting:-

Casting is a manufacturing process by which a liquid material is usually poured into a mold, which contains a hollow cavity of the desired shape, and then allowed to solidify. The solidified part is also known as a casting, which is ejected or broken out of the mold to complete the process.Casting is most often used for making complex shapes that would be otherwise difficult or uneconomical to make by other methods.

Advantages:-

1.Size of cast objects vary over large range. An object from 5gm to 200 tonn, anything can be cast.

2.Casting can be effectively used for complex shaped objects.

3.Component made with casting process is lighter than the component made with other machining processes.

4.Casting provides versatility. Wide range of properties can be attained by adjusting percentage of alloying elements.

5.Casting can be made with hair like precision provided proper molding and casting technique is employed.


Disadvantages:-

1.Though casting is cheapest for MASS Production, it becomes non economical in case of JOB production.

2.Sand casting leaves rough surface which needs machining in most of cases. It adds up the cost in production.

3.Again in sand casting, poor dimensional accuracy is achieved.

4.Cast products are superior for compressive loads but they are very poor in tensile or shock loads.(They are brittle).

Connected Cars

Connected Cars

The U.S. Department of Transportation announced that all cars, trucks, and buses to be equipped with V2V (vehicle-to-vehicle) communication systems that let cars to be connected.
Vehicle-to-Vehicle Communications for Safety is the dynamic wireless exchange of data between nearby vehicles that offers the opportunity for significant safety improvements. By exchanging anonymous, vehicle-based data regarding position, speed, and location, V2V communications enables a vehicle to: sense threats and hazards with a 360 degree awareness of the position of other vehicles and the threat or hazard they present; calculate risk; issue driver advisories or warnings; or take pre-emptive actions to avoid and mitigate crashes.

According to research V2V communication system could save 82 % of automobile crashes and reduce CO2 emissions, by avoiding congested routes. The system will also improve self-driving cars.

What is Dynamic Stability?

What is Dynamic Stability?

If an aircraft is statically stable, it may undergo three types of oscillatory motion during flight. When imbalance occurs the airplane attempts to retain its position, and it reaches the equilibrium position through a series of decaying oscillations, and the aircraft is said to be dynamically stable. If the aircraft continues the oscillatory motion without decay in the magnitude, then the aircraft is said to be on dynamically neutral. If the magnitude oscillatory motion increases and the aircraft orientation start to change rapidly, then the aircraft is said to be dynamically unstable.

An aircraft that is both statically and dynamically stable can be flown hands off, unless the pilot desires to change the equilibrium condition of the aircraft.

What is the difference between Dynamic and Static Stability (of Aircrafts)?
• Static stability of an aircraft describes the tendency of and aircraft to retain its original position when subjected to unbalanced forces or moments acting on the aircraft.
• Dynamic stability describes the form of motion an aircraft in static stability undergoes when it tries to return to its original position

What is heat transfer and explain various modes of heat transfer?

Quick Notes:-

What is heat transfer and explain various modes of heat transfer?

Ans.-Heat transfer is a discipline of thermal engineering that concerns the generation, use, conversion, and exchange of thermal energy and heat between physical systems.

The three modes of heat transfer are:-

(i)Conduction

(ii)Convection

(iii)Radiation

(i)Conduction

Heat conduction occurs as hot, rapidly moving or vibrating atoms and molecules interact with neighboring atoms and molecules, transferring some of their energy (heat) to these neighboring particles.Conduction is the most significant means of heat transfer within a solid or between solid objects in thermal contact.

(ii)Convection

Convective heat transfer, or convection, is the transfer of heat from one place to another by the movement of fluids, a process that is essentially the transfer of heat via mass transfer.Convection is usually the dominant form of heat transfer in liquids and gases.

(iii)Radiation

Thermal radiation is energy emitted by matter as electromagnetic waves, due to the pool of thermal energy in all matter with a temperature above absolute zero. Thermal radiation propagates without the presence of matter through the vacuum of space.Thermal radiation is a direct result of the random movements of atoms and molecules in matter.

What is Deburring?

What is Deburring?

The raised particles and shavings that appear when metal blanks are machined are referred to as burrs, and the process by which they are removed is known as deburring.Deburring is important for quality, aesthetics, functionality, and the smooth operation of working parts.

There are many deburring processes, but the most common are mass-finishing, spindle finishing, media blasting, sanding, grinding, wire brushing, abrasive flow machining, electrochemical deburring, electropolishing, thermal energy method, machining, and manual deburring.