22-06-2013, 01:05 PM
PROJECT PROFILE ON PISTON RING
PISTON RING.pdf (Size: 112.46 KB / Downloads: 134)
INTRODUCTION.
Piston ring is one of the most important part of the Deisel/Petrol engines.It is an open-ended ring that fits into a groove on the outer diameter of a piston in a reciprocating engine such as an internal combustion engine or steam engine. The principal function of the piston rings is to form a seal between the combustion chamber and the crankcase of the engine. The goal is to prevent combustion gases from passing into the crankcase and oil from passing into the combustion chamber
The three main functions of piston rings in reciprocating engines are:
1. Sealing the combustion/expansion chamber.
2. Supporting heat transfer from the piston to the cylinder wall.
3. Regulating engine oil consumption.
During the compression and power strokes, the compression ring seals the combustion gases and prevents blow-by. Although blow-by is not completely eliminated it is kept to an acceptable limit. During the compression and exhaust strokes the cylinder walls are lubricated with oil by throw off from the connecting rod bearings. Excess oil is wiped off by the piston rings. Not only does the oil ring have the responsibility of wiping the excess oil off the cylinder walls, but the job is also shared by all of the rings, leaving a fine layer of oil on the wall to provide lubrication for the following ring. As rings wear, the ability to perform these functions is decreased resulting in oil consumption and blow-by. When this happens it is time for a new set of rings.
MARKET POTENTIAL
Piston ring is the one of the most replaceble part of the diesel/petrol engines.It has great demand in the replaceble market as well as in new engines market.For the last few years there is noticeble increase in the automobile industry, which is the vast market for it. Piston rings are not only used in the automobile industry but also used in : Railway Engines Compressors Steam Hammers Cars Retaining Rings
BASIS AND PRESUMPTIONS
The information supplied is based on a standard type of manufacturing activity utilizing conventional techniques of production and optimum level of performance. 75% of the envisaged capacity is taken as efficiency on single working shift. Labour and wages are required as per present circumstances. The cost in respect of land & building, machine & equipment, raw material & selling price of finished product etc are those generally obtained at the time of preparation of project profile and may vary depeding upon the location, make and for variety of resons. The interest on total capital has been assumed @ 14% p.a
MANUFACTURING PROCESS
Piston rings are generally made up of cast iron. The blanks of cast rings of required size and desired properties are procured from the local foundries. After that blanks are cleaned and get ground. Then the blanks are undergone through various processes like facing, rough diameter, rough bore, finish diameter & finish bore. The rings are generally machined to the required shape by means of turning, a process in which the ring blank, already axially ground, is copy turned on the inside and outside diameters. After a segment equivalent to the free gap is cut from the ring it assumes the free shape that will give it the required radial pressure distribution when fitted into the cylinder..