1. Characteristic of engine

----DL08 diesel engine of Doosan uses overhead camshaft and turbine supercharger. It is an electric controlling engine by using cooling fan.

----The fuel is prepared for injection. It is stored in high pressure storage tank under pressure. The quantity fuel injected is confirmed by driver. Injection start-up and pressure are calculated through ECU according to stored data. ECU initiates sensor of electromagnetic valve on the cylinder of engine so that every injection device on it jets correspondingly.

----In order to come true the position of decreasing the temperature of prediction, oil channel cooling is used on engine piston. The design of channel, the design of nozzle, position and oil flow rate in channel are very important. The design of section Shape for channel should make oil flow fully so as to reach maximum cooling performance.

2. The advantage of common rail engine

----Common rail, fuel which is suitable to operate is controlled with ECU. The method of jet directly to fuel carrying compartment decreases the work efficiency of engine, reduces the emission of harmful substances.

----Common rail technology is a fuel supply style which separates production and process of injection pressure completely each other in the close-loop system composing with high pressure pumps, pressure sensors an ECU. It makes the oil pressure of public fuel supply tubes accurate control by transporting the pressure fuel from high pressure pumps to public fuel supply tubes. The size of high-pressure pipe is independent of the speed of engines. Common rail fuel injection is a high-end technology of diesel engine. The engine which has the technology of common rail fuel injection can establish higher injection pressure without the Restricted of diesel engine’s speed. And it reduces the vibration and noise which is occurred by connection of machines as possible.

3. The injection characteristic of common rail

----Has BOSCHCP3.3 fuel electric control high pressure pump, working pressure 1600bar, injection pressure flexible to adjust, jet accurately, dynamic properties

----To realize the optimization of mixing the fuel and air, save the fuel from 5% to 10%

----Electric control speed and output in the whole field

----Control the injection pressure and injection time of speed and output in the whole field

----Realize the optimization of injection, noise and combustion in many stages

4. Compose by 4 valve and common rail combustion system

----Electric control common rail

----4 valve / cylinder

----New combustion system (double-inlet / exhaust)

----Ax symmetric injection (8 holes)

Remarks: Realize the optimization of high-output, low-pollute harmful gas emission and fuel of environment,

5. Electric control system (ECU)

----To use in controlling the fuel supply of engine

----ECU connect with all kinds of sensor to control engine keeping the best state on the base of the engine with input value of digital

6. The mainly parts of common rail system

----ECU

----Crankshaft speed sensor

----Camshaft speed sensor

----Accelerated pedal sensor

----Fuel temperature sensor

----Air inlet pipe pressure and temperature sensor

----Common rail pressure sensor

----Cooling water temperature sensor

----Engine oil temperature sensor

By using these sensor to input the digital, ECU records the requirement of drivers and working performance of engine and vehicle,. On base of these information, ECU can regulating effect on intervening open loop control and closed-loop control of vehicle especially engines.

7. The characteristic of turbine turbocharger

Turbocharged intercooling system includes water-air intercooler and air-cooled. The air-cooled consists of sensor, air-air air-cooled, turbocharger lubricating oil filter core and corresponding inlet and outlet pipe. The water-air intercooler consists of sensor, water-air air-cooled, turbocharger lubricating oil filter core and corresponding inlet and outlet pipe. The sensor consists of exhausted gas turbine and compressors. Working principle: Using waste gas energy of diesel engine excretion, to drive the turbine high-speed rotate, drive the Compressor Impellers of Coaxial turbine high-speed rotate, the compressor compresses the air to engine combustion chamber, increases quantity of aeration of engine so that combustion will be more sufficiently and improves the power of engine, decreases the oil consumption, reduces the emission of harmful substances in the waste gas.

Supercharger can make diesel engine reach the purpose of increasing output power on the situation of the same displacement and increased weight.

The meaning of supercharger increase the air pressure is increasing the density of air, but air temperature will increase, too. The temperature of out tuyere of engine turbocharger will increase with pressure increasing , the increasing temperature will limit the density of air increasing. If we want to increase the density of air further, we should reduce the temperature of charger-air. According to experiment display, under a same air natural gas ratio, the temperature of charger-air each decreases 10 degree centigrade, the power of diesel engine will increase 3%~5%, and it will also reduce NOx in emission and improve the low-speed performance of engine. Therefore, intercooling technology appears. DL08 engine can cool the temperature of turbocharged air to 50~60 degree centigrade by using air-air air-cooled, through pipe compressed air to a radiator and provides cooling air to cool by fan.

Points for attention:

----Idle speed to run with 3~5 min after starting every time, supply oil engine should reach bearing step of turbocharger.

----Be care for the noise and vibration of turbocharger when it is running, check the sealing of every link, no leak phenomenon (If it happens leakage, pressure ratio will be effected so that the power will be reduced and fuel consumption will be increased). If it happens leakage, you should eliminate immediately.

----When it is running with high-speed and full-load, you must not stop immediately in special condition, you should decelerate gradually, reduce load and idle speed to run with 3~5 min before stopping so as to avoiding damage the turbocharger with lack of oil or gadget overheat. Meanwhile, you should avoid idling speed to run for a long time.

----It strictly forbids the driver to use the operation method of ‘acceleration-flameout-neutral position skidding’, because the engine will flameout suddenly under the high temperature of full-load, oil pump will stop working, lubricating oil can not take the heat of parts in the turbocharger away so that the turbocharger will be damaged by overheat.

8. Points for attention as you controlling:

----Necessary rules:

1.        It is necessary to read the instruction and guarantee repair handbook as vehicle unhouse.

2.        You should completely comprehend the mainly management project of content.

----Pay attention to battery leakage

1.        Open the door for a long time in the condition of automatic will lead to battery leakage.

2.        When the engine is stopped, please not keep the master switch with ‘ON’ for a long time.

----Running warning:

1.        If there is red warning lamp or warning sound in the instrument as the bus running, you should stop the bus marinate slowly, after find the fault, notify the vehicle manager, according to the indicator to measure..

2.        Negligence will lead to a serious accident.

----ABS warning lamp

1.        If ABS warning lamp is flashing as running, it just means rescind the function of ABS, the braking has already worked normally.

2.        The problem of ABS does not lead to other safety accidents.

----Start function will open the lamp in running operation:

1. ASR warning lamp, 2. Air dryer, 3. Parking brake equipment, 4. Engine preheating lamp, 5. Engine allowance brake, 6. Auto-lubricating system, 7. Speed limiting device