SISTEMAS COMMON RAIL
COMMON RAIL, CRDIor "Common Rail Direct Injection", is the denomination of a system of direct injection of diesel fuel under high pressure in internal combustion engines. Developed in the middle of 1990, initially developed for heavy vehicles and later adapted for light automobiles. The Commo Rail injection system was developed aiming better performance, increases fuel efficiency and reduces gas emissions.
How the system works Common Rail Diesel consists of: The pressure generation is carried by a tube to the HIGH PRESSURE PUMP. The pump compresses the fuel and sends it to the RAIL orifice (distributor tube) through a high-pressure conduit, which acts as a common high-pressure accumulator for all INJECTORS.
INJECTORS COMMON RAIL
YouinjectorsCommon Rail receive pressurized diesel oil from the rail and inject it into the engine's combustion chamber. The injection is carried out commanded by the command box, which electrically actuates the solenoid of each injector. With pressure is always available on Rail.
A common rail injector plays an important role in the system, being responsible for the proper functioning of the vehicle. Its function is to inject fuel under high pressure into the engine cylinder with precision and correct pressures, determined by the module's electronic command.
HIGH PRESSURE PUMPS
Allhigh pressure pumpsCommon Rails have the same operating principle: a shaft connected to the engine moves an internal mechanism with elements similar to pistons, which receive diesel from the low pressure line and pump it under high pressure according to the demand of the injection system. The differentiation between them occurs in four aspects: pumping capacity (in liters/hour), low pressure pump concept (mechanical or electric), control device
rail pressure gauge (DRV or M.Prop valve) and possibility of repair
High pressure pumps can be divided into three different components: low pressure, high pressure and control.
TOOLS FOR COMMON RAIL SYSTEMS
Robiel has in its product line the complete tooling to carry out the Disassembly, Assembly and Lapping of High Pressure Pumps and Common Rail Injectors.
Bringing workshops across Brazil and the world more practicality and agility in repairing Common Rail systems.
Tools for Injectors It is High Pressure Pumps
Launched in 1989, theUP unitswere the firstdiesel electronic injection systemfor commercial vehicles on the market. Through this system, the dosage and injection of fuel are electronically controlled by a unit called the ECU (Electronic Control Unit). After this period, seeking an evolution, in 1994 the UI system was launched, which is characterized by the combination of the injection pump and the injection nozzle in a single unit.
Oneinjector unit(UI) is an integrated high pressure direct fuel injection system for diesel engines, combining the injector and injection pump into a single component. The plunger pump used is usually driven by a shared camshaft. In an injection unit, the device is usually lubricated and cooled by the fuel itself.
High pressure injection offers power and fuel consumption benefits over previous lower pressure fuel injection by injecting fuel as a larger spray giving a much higher surface area to volume ratio. This provides for improved vaporization of the surface of the fuel droplets and therefore a more efficient combination of atmospheric oxygen with the vaporized fuel, providing a more complete and cleaner combustion.
feeder pumpsare responsible for pumping fuel from the tank to feed the injector units. Feeder pumps have a simple operating principle, where two gears rotate in opposite directions, generating pressure in the diesel oil that directs it to the injector units.
Feeder pumps have a capacity to generate pressure and flow greater than electric pumps, and have a reinforced construction that guarantees repair instead of replacement.
TOOLS FOR INJECTOR UNITS AND FEED PUMPS
Robiel has in its product line the complete tooling to carry out the Disassembly, Assembly and Lapidary of Injector Units and Feeder Pumps.
Bringing repair shops across Brazil and the world more practicality and agility.
Tools for Injection Units It is Feeder Pumps
Injection Pump is a power supply subsystem dos diesel engines. The system initially used in stationary engines Rover is responsible for pumping de oil in high pressure, in generator sets and in large machines de ships, later on smaller vehicles like trucks e automobiles volkswagen TDI, with its development being the responsibility of the group Bosch.
Injection pump for diesel engines, refers to a mechanical pumping system with pistons that works immersed and lubricated in itself fuel oil thus avoiding large adjustments to small pistons.
The system is sized to provide high pressure on the nozzle needle and thus defeat a back pressure of the air inside the cylinder already compressed. This operation that takes place at the time of compression is the exact moment that o piston do piston is found before neutral superior, a predetermined amount of fuel is sprayed.
In reality, it is the springs that press as valves closed doors that yield “under pressure” and release the oil trapped in the injector nozzle; this one enters atomized na combustion chamber and reacts with o oxygen compressed.
Inline injection pump - it is intended to send the diesel under pressure to each of the injectors in perfectly regulated quantities according to a acceleration of the engine and at the most convenient moment for its proper functioning.
The injection pump is built by: pump body com sump, visit window e collector power. In the crankcase is the camshaft (from the injection pump, which is not the camshaft of the engine), the feed pump and the impellers.
In the visit window is ruler rack and the pump elements which are made up of a cylinder, piston and liner with toothed sector. The check valves are located in the feed manifold and the automatic speed regulator is located at the end of the rack rail.
Rotary injection pumps - allows a fast operation and smaller dimensions than the in-line injection pumps, they are generally used in Diesel engines of low specific power and for automobiles, which are applications with low demand for use, since the rotary injection pumps have a volumetric injection capacity smaller than the pumps in line.
Fuel distribution is carried out using reciprocating pistons that distribute fuel to each of the engine injectors through a distributor. During operation, all its parts are lubricated by the fuel itself that goes to the injectors, not requiring any supplementary lubrication system.
Fuel distribution is carried out by displacing the two opposite pistons, located in a seat placed transversely inside the fixed element which is the hydraulic head. This impeller assembly and hydraulic head constitute the pump manifold. The opposing pistons are driven by the eccentrics that are in the housing of the body where the rotor moves. Usually in the housing of the pump body there is a number of eccentrics equal to the number of cylinders in the engine.
When the opposing pistons are driven by the eccentrics during the movement of the rotor, they send the fuel under high pressure to the channels that are part of the distributor, which coincide at well-defined intervals with holes in the hydraulic head to feed each of the injectors.
PARTS FOR TURBINE
To further increase the power and efficiency of engines, the industry developed the turbo compressor, or just turbo. This system, patented in 1905 by the Swiss Alfred Büchi, aims to supercharge engines with air, since the cylinder filling rate, caused by the depression created by the movement of the piston towards its bottom dead center, does not represent more than 80% of the 90% of the unit displacement of the cylinder.
In aspirated engines (without turbo), the opening and closing of the intake valves lead to the formation of pressure waves that cause a slight increase in the intake manifold, which makes it difficult for air to enter the cylinders.
The turbo compressor then serves to offer more power without having to increase the size of the engine. As efficiency is directly related to the mass of air that the engine can draw in per intake cycle, the turbo's mission is to compress the air before it is admitted, resulting in more air mass in the combustion chamber, and more air means more fuel can be added.
Therefore, more power is obtained from the explosions in each cylinder. A turbocharged engine produces more power than the same engine without the device. This can significantly improve the engine's power-to-weight ratio.
The turbo compressor, previously used only in large diesel vehicles and sports cars, is now used in all types, especially in those that need lower consumption. It is part of the “downsizing” concept, with smaller engines capable of delivering the same power as the larger ones, with benefits in terms of fuel consumption.
The use of turbines is especially important in diesel engines, because by increasing the pressure and temperature inside the cylinders, the risk of detonation is reduced. application on these engines.
Actuators | Relief Valve | Wastgate
The Actuator or wastegate is a valve responsible for controlling the pressure in the system, it is possible to find this valve in the vast majority of cars with turbo without variable geometry. This valve reacts to the pressure of the turbo allowing only a part of the exhaust gases to pass through the turbine, in order to control the maximum pressure.
With less gases passing through the turbine, the compressor rotates more slowly, stabilizing the turbo pressure. The Actuator forwards the remaining gases to the exhaust manifold. There are actuators internal or external to the turbo.
Normally, when cars are equipped with these valves and the turbo is moved or the maximum operating pressure is increased, the actuator actuation mechanism may not be sufficient to work at said pressures and the valve has to be replaced._cc781905-5cde- 3194-bb3b-136bad5cf58d_