TRAINING ON DIESEL AND GASOLINE SYSTEMS

Thirty - six students of final year students from Mechanical Engineering Department of Dronacharya Group of Institutions, Greater Noida, attended Training program on “Diesel and Gasoline System” at Bosch Training Centre from 21 - 24 September 2015. Mr. Parag kavthekar (Trainer , BOSCH ) and Ms Deepika Sharma (Trainer , BOSCH ) conducted the training at BOSCH Training Centre. They shared their immense knowledge in Diesel and Gasoline Systems.

About Bosch Training Centre

The Bosch Training Centre with state of the art facilities / equipments was established in the year 2005 and has facilities for training and testing various automotive products and vehicles besides diagnostics on vehicles fitted with Electronic Control Unit. Bosch Training Training Centre conducts a variety of training programmes to meet different customer requirements where the level of participants ranges from Mechanics to Managers / Proprietors and from Engineers to Senior Executives drawn from BOSCH Authorised Representatives, OE customers and their dealers, Defence Establishments, State Transport Undertakings, Fleet Operators as well as Educational Institutions. A variety of training films, cut - away and transparent models make learning interesting and enjoyable.

Content of Training Program

The training session on Diesel and Gasoline System was divided into different components as mentioned below:

1. Introduction to Basic of Engine and its classification

2. Components

3. Difference between Petrol and Diesel Engine

4. Practical Demonstration of Petrol engine and Diesel engine

i- Working of Petrol Engine

ii- Working of Diesel Engine

5. Introduction to Diesel Injector Pumps

6. Types of Pumps.

7. Sensors and its types.

8. Actuators.

9. Introduction to KTS and ESI (TRONICS).

About Training Session

INTRODUCTION TO BASIC OF ENGINE

First day of training session at Bosch Centre started with introduction to Basics of Engine.An Engine is a device which transforms one form of energy into another form. It is a machine with moving parts that converts power into motion. The Engine used in automobiles is Heat Engine. Heat engine is a device that transforms chemical energy of a fuel into thermal energy and utilizes the thermal energy to perform useful work. In other words heat engine is a system that converts heat or thermal energy and chemical energy to mechanical energy, which can then be used to do mechanical work.

Heat engine is broadly classified into two parts Internal combustion engine (IC engines) and External Combustion Engine (EC Engines). The engine is the heart of an automobile. The engine changes energy into motion. In Internal combustion the energy is derived from the controlled burning of fuel inside of the engine. Hence, we call it the internal combustion engine ( I C ENGINES) which is used in almost all vehicles.

Internal combustion engine ( I C ENGINES) are of two types : Two stroke I C engine and Four stroke I C engine.

1. Two stroke I C engine

A two - stroke, or two - cycle, engine is a type of internal combustion engine which completes a power cycle with two strokes (up and down movements) of the piston during only one crankshaft revolution. In a two - stroke engine, the end of the combustion stroke and the beginning of the compression stroke happen simultaneously, with the suction and exhaust functions occurring at the same time. Two stroke engines often have a high great power to weight ratio. The two stroke engine ignites every revolution of the crankshaft. These engines overlap operations to reduce parts while maintaining power. In two stroke engines the crankcase is a pressurization chamber to force fuel / oil / air into the cylinder. Here you mix oil and gas to lubricate internal parts. Simply put, in a two stroke engine you have only: Compression and Combustion , thus called two strokes.

2. Four stroke I C engine

In four stroke engines the crankcase is separate from the compression chamber. This allows the use of heavy oil for lubrication. A four - stroke engine is an internal combustion engine, which converts gasoline into motion. This is the most common car engine type which is relatively efficient and inexpensive. A four-stroke engine (also known as four cycle) is an internal combustion (IC) engine in which the piston completes four separate strokes while turning a crankshaft. A stroke refers to the full travel of the piston along the cylinder, in either direction. In four stroke engine , cycle is completed in four strokes of piston & in two revolution of crankshaft. Here heavier flywheel is needed and power produced for same size of engine is less, but the volumetric efficiency is more due to more time for induction.

COMPONENTS OF ENGINE

Components of Engine can be classified into following key parts :

Spark plug :- The spark plug supplies the spark that ignites the air / fuel mixture so that combustion can occur. The spark must happen at just the right moment for things to work properly.

Valves :- The intake and exhaust valves open at the proper time to let in air and fuel and to let out exhaust. Note that both valves are closed during compression and combustion so that the combustion chamber is sealed.

Piston :- A piston is a cylindrical piece of metal that moves up and down inside the cylinder.

Piston rings :- Piston rings provide a sliding seal between the outer edge of the piston and the inner edge of the cylinder. The rings serve two purposes:

1. They prevent the fuel / air mixture and exhaust in the combustion chamber from leaking into the sump during compression and combustion.

2. They keep oil in the sump from leaking into the combustion area, where it would be burned and lost.

Connecting rod :- The connecting rod connects the piston to the crankshaft. It can rotate at both ends so that its angle can change as the piston moves and the crankshaft rotates.

Crankshaft :- The crankshaft turns the piston's up and down motion into circular motion just like a crank on a jack-in-the-box does.

Sump :- The sump surrounds the crankshaft. It contains some amount of oil, which collects in the bottom of the sump (the oil pan).

DIFFERENCE BETWEEN PETROL ENGINE AND DIESEL ENGINE

PRACTICAL DEMONSTRATION OF ENGINE

1. Working of Petrol Engine

A petrol engine ( known as a gasoline engine ) is an internal combustion engine with spark - ignition, designed to run on petrol (gasoline) and similar volatile fuels.In most petrol engines, the fuel and air are usually pre - mixed before compression (although some modern petrol engines now use cylinder - direct petrol injection). The pre - mixing was formerly done in a carburetor, but now it is done by electronically controlled fuel injection, except in small engines where the cost / complication of electronics does not justify the added engine efficiency.

2. Working of Diesel Engine

The only difference between diesel engine and a four - stroke gasoline engine is there is No sparkplug on Diesel engine, has a higher compression ratio and better fuel mileage. First, air is allowed into the cylinder and the piston compresses it. Compressing a air generates heat. Once the air is compressed, a mist of fuel is sprayed into the cylinder typically (in a modern engine) by an electronic fuel - injection system, which works a bit like a sophisticated aerosol can. (The amount of fuel injected varies, depending on how much power the driver wants the engine to produce.) The air is so hot that the fuel instantly ignites and explodes without any need for a spark plug. This controlled explosion makes the piston push back out of the cylinder, producing the power that drives the vehicle or machine in which the engine is mounted. When the piston goes back into the cylinder, the exhaust gases are pushed out through an exhaust valve and, the process repeats itself hundreds or thousands of times a minute.

INTRODUCTION TO DIESEL INJECTOR PUMPS

An Injection Pump is the device that pumps diesel (as the fuel) into the cylinders of a diesel engine. Traditionally, the injection pump is driven indirectly from the crankshaft by gears, chains or a toothed belt (often the timing belt) that also drives the camshaft. It rotates at half crankshaft speed in a conventional four - stroke diesel engine. Its timing is such that the fuel is injected only very slightly before top dead centre of that cylinder's compression stroke. It is also common for the pump belt on gasoline engines to be driven directly from the camshaft. In some systems injection pressures can be as high as 200 MPa.

TYPES OF DIESEL INJECTOR PUMPS

Various types of diesel injector pumps are as following :

1. PF (Single cylinder pumps) - A diesel engine injection pump is used to increase the pressure of the diesel fuel from very low values from the lift pump to the extremely high pressures needed for injection.

2. VE (Distributor (Rotary) pumps) - A distributor diesel injection pump is a high-pressure pump assembly with lines leading to each individual injector.

The high - pressure lines between the distributor and the injectors must be the exact same length to ensure proper injection timing.

3. CR systems (common rail systems) - Newer diesel engines use a fuel delivery system referred to as a high - pressure common rail (HPCR) design. Diesel fuel under high pressure, over 20,000 PSI (138,000 kPa), is applied to the injectors, which are opened by a solenoid controlled by the computer.

INTRODUCTION TO SENSORS AND ITS TYPES

Sensor is device which detects or measures a physical property and records, indicates, or otherwise responds to it. it is an object whose purpose is to detect events or changes in its environment, and then provide a corresponding output. A sensor is a type of transducer; sensors may provide various types of output, but typically use electrical or optical signals. The engine sensors are generally the electro-mechanical devices used to monitor various engine parameters. Different types of sensors are used in the engine; which primarily consists of Thermocouple, Resistance Temperature Detectors (RTDs), and Hall Effect sensors. A modern day car’s Engine Management System consists of a wide range of electronic and electrical components comprising of engine sensors, relays and actuators which work together to provide the car’s Engine Control Unit with vital data parameters essential to govern the various engine functions effectively.

WHAT IS ACTUATORS

Actuators are devices used to produce action or motion. Inputs are mainly electrical signal / Air/ Fluids which can be of lower or higher power. An actuator is a type of motor that is responsible for moving or controlling a mechanism or system. It is operated by a source of energy, typically electric current, hydraulic fluid pressure, or pneumatic pressure, and converts that energy into motion. An actuator is the mechanism by which a control system acts upon an environment. The control system can be simple (a fixed mechanical or electronic system), software - based (e.g. a printer driver, robot control system), a human, or any other input. Actuation can be from few microns to few meters.

INTRODUCTION TO ECU (ELECTRONIC CONTROL UNIT)

An engine control unit (ECU) is a type of electronic control unit that controls a series of actuators on an internal combustion engine to ensure optimal engine performance. In automotive electronics, electronic control unit (ECU) is a generic term for any embedded system that controls one or more of the electrical system or subsystems in a motor vehicle. The working of Electronic Control Unit include Control of air / fuel ratio, control of idle speed, control of variable valve timing , Electronic valve control. KTS is diagnostic equipment developed and produced by BOSCH long time back. Bosch's primary range of test equipment is the KTS 500, KTS 500C, KTS 520, KTS 550 and the KTS 650. The functionality of the KTS is dependent on a continued annual subscription to ES([tronic).

The Training program at BOSCH Training Centre not only enriched the technical knowledge of the students and participants, but also has unparsed the maturity of thorough knowledge and Vision.