DEPARTMENT OF MECHANICAL ENGINEERING

ENGINE AUXILIARY SYSTEMS IGNITION SYSTEM The fuel feed system for the Spark ignition engines and Compression ignition engines are clearly discussed below.   Fuel Injection system for SI engines; Carburetion             Spark-ignition engines normally use volatile liquid fuels. Preparation of fuel-air mixture is done outside the engine cylinder and formation of a homogeneous mixture is normally not completed in the inlet manifold. Fuel droplets, which remain in suspension, continue to evaporate and mix with air even during suction and compression processes. The process of mixture preparation     here in this diagram we can see all the various parts of the system . 1.     The fuel starts moving from the fuel tank because of the pump working to suck in the fuel from the fuel tank 2.     After that the fuel travels through the filter , which filters out the unwanted materials from the liquid . ...

Errors in Threads       Errors in screw threads are related to the five elements of the screw threads. They are major diameter, minor diameter, pitch diameter, pitch and thread angle. If any errors are taking place in these five elements the produced screw is rejected. So, these elements are also be checked with proper gauging system carefully. The threads are produced by a point cutting tools.      The errors in major and minor diameter cause interference of the mating threads, less root section, less wall thickness and poor contact of the flanks, which ultimately cause the weak in strength of the component. The errors in effective diameter also cause the interference of the flanks.      The errors in pitch and thread angle also cause the progressive tightening of the mating parts due to the interference of the flank surfaces.      Let us discuss some important errors in thread forms. They are Drunken error Pitch errors ...

  Screw Threads Terminology Screw thread is a continuous helical groove of specified cross-section produced on the external or internal surface. A screw thread formed on a cylinder is known as straight or parallel screw thread, while screw thread formed on a cone or frustum is known as the tapered screw thread. Axis of a thread: This is an imaginary line running longitudinally through the center of the screw. Crest: Crest of the thread is the top most surface joining the two sides. Root: Root of the thread is the bottom of the groove between the two flanks. Flank: Flank of thread are straight edges which connect the crest with the root of the thread. Pitch: Pitch of a thread is the distance measured parallel to the axis from a point on a thread to the corresponding points on adjacent thread forms in the same axial plane and on the same side of the axis. Depth of thread: Depth of a thread is the distance between the crest and root of the thread. Major diameter: It is an imagi...

  Metal casting processes •      Casting is one of the oldest manufacturing process. It is the first step in making most of the products.   •      Steps: -      Making mould cavity -      Material is first liquefied by properly heating it in a suitable furnace. -      Liquid is poured into a prepared mould cavity -      allowed to solidify -      product is taken out of the mould cavity, trimmed and made to shape   We should concentrate on the following for successful casting operation: (i)Preparation of moulds of patterns (ii)Melting and pouring of the liquefied metal Solidification and further (iii)    cooling to room temperature (iv)Defects and inspection Advantages •     Molten material can flow into very...