Engine knowledge introduction, electronically controlled high pressure common rail injection technology
Engine is one of the main parts on the excavator, it has often been compared to 'the heart of the excavator, engine fuel heat energy into mechanical energy, become the power source of the excavator.
Current excavator engine is mostly used by diesel engine, diesel engine than gasoline engine has the advantages of high thermal efficiency, good dynamic performance.
With the continuous development of engine manufacturing technology, engine manufacturers at home and abroad to launch a new type of high-tech products to meet the diverse needs of people.
In the field of industrial engine, a famous brand for isuzu, cummins, according to Mr. Tao, etc. , the manufacturer of diesel engine used in industry, widely used in the dynamic system of excavators and other construction machinery.
In general, the engine power system made up of two large institutions and five major systems: the crank connecting rod mechanism, with gas institutions, fuel supply system, lubrication system, cooling system, startup system and engine control system.
Throughout the use of the diesel engine in excavator product line isuzu diesel engine production occupies a great market share.
From another perspective, isuzu diesel engine is a typical product of the diesel engine.
Now, compare the new diesel engines are in the third generation of fuel oil supply system
Electronically controlled high pressure common rail injection technology.
Now in isuzu diesel engine fuel supply system, for example, to ask everybody to do the introduction.
The composition and working process of the fuel oil supply system: isuzu diesel engine fuel supply system is mainly composed of engine control module (
And high pressure oil pump, high pressure common rail pipe, electronic fuel injector and various sensors, etc.
Low pressure electromagnetic pump will enter the high pressure oil pump, fuel oil after high pressure oil pump pressure will supply to the high pressure common rail pipe, high pressure fuel engine control module (
Comprehensive information of various sensors, according to the running state of the machine to determine the appropriate injection period, the control of electronic fuel injector will fuel spray from the high pressure common rail pipe into the cylinder.
Due to very high pressure fuel injection holes and small, so the uniform fuel atomization, burning full, can output great power.
Engine control module (
: the engine control module (
Is the control core of diesel engine, which monitor send over the information from the various sensors, such as speed, load, transmission gear, crankshaft position, cooling water temperature, oil temperature, etc. , and to obtain the signal processing of decisions and issue instructions and to control the engine system.
Engine control module (
Also can carry on the diagnosis of system function, when the operation of the system and the fault detection and fault warning signal warnings operator and diagnose fault code will be recorded at the same time.
So that maintenance personnel can be used to identify the area of fault code to judge fault, maintenance work more effectively.
: all kinds of sensors in the more than 10 kinds of sensor on the diesel engine is similar to the body's nervous system, they will be the engine of the measured data in the form of electrical signals timely feedback to the ECM, so that the ECM to send out the corresponding control instruction according to the operation condition of the machine.
These sensors include the crankshaft position sensor, camshaft position sensor, coolant temperature sensor, fuel temperature sensor, atmospheric pressure sensor, common rail pressure sensor, the manifold pressure sensor, oil pressure sensor, pressurized air intake temperature sensor, air intake temperature sensor, and so on.
Electromagnetic pump: due to the fuel filter and prefilter used remote control, fuel oil supply from the tank to the function of the distance of the high pressure oil pump.
Therefore, in order to make the fuel from fuel tank out and easy to discharge the air in the renovation, thus adding the electromagnetic pump, to reduce the load of high pressure oil pump.
The rotary force of high pressure oil pump using the engine drive three plunger, fuel after dealing with the plunger compression pressure into a high pressure fuel, and then be sent to common rail.
Common rail pipe receiving oil pump fuel supply, and maintain a common rail fuel pressure (
And the fuel is assigned to each fuel injector.
Common rail are installed on common rail pressure sensor, flow regulator and pressure limiter.
Injector is installed on the cylinder head, injector according to the ECM instructions to make a certain amount of fuel into the cylinder, after get good atomization so as to promote the fuel ignition and combustion.
Control of injection timing and injection quantity is implemented by controlling the fuel injector.
At this stage of domestic oil extraction technology and the big gap between foreign domestic diesel with foreign purity, combined with the system maintenance cost of parts of expensive, caused the high pressure common rail diesel engine in domestic 'failed to sell' phenomenon.