5.3.1. Direct injection
Arrangement of elements of fuel system in a TDI engine compartment
| 1 - the valve of system of recirculation of the fulfilled gases 2 - perepuskny the valve of the soaking-up gate 3 - a nozzle with the sensor of movement of a needle 4 - monitor For system of direct injection of fuel. The sensor of height is built in the monitor. 5 - Ø/m the valve of vacuum management of recirculation of the fulfilled gases 6 - electromagnetic valve For restriction of pressure of the given air. 7 - measuring instrument of mass of air 8 - sensor of temperature of cooling liquid 9 - engine RPM meter 10 - shtekerny connection Sensor of movement of a needle. 11-shtekerny connection of the sensor of speed of the engine 12 - TNVD shtekerny connection For the sensor of temperature of cooling liquid, the control point adjustment of quantity, the sensor of movement of the adjusting gate, the valve of switching off of supply of fuel and the valve of the beginning of injection. 13 - the valve of the beginning of injection of fuel, for in oil pressure 14 - fuel supply shutdown valve |
15 - executive body of regulation of amount of the TNVD injectable fuel With the fuel temperature sensor, the quantity control point adjustment sensor of movement of the adjusting gate. 16 - the sensor of pressure of the soaked-up air with the sensor of temperature of the soaked-up air. Other details (are not represented). 17 - control unit of transmission 18 - heating element of the PSV system 19 - fuel temperature sensor, quality regulator, sensor of replacement of modulation of the piston And - the brake pedal switch In - the region of legs, at a brake pedal. In - the stoplight switch In - the region of legs, at a brake pedal. With - the sensor of position of the accelerator pedal In - the region of legs, at a brake pedal. D - coupling pedal switch In - the region of legs, at a coupling pedal. |
Vacuum pipelines of the turbodiesel engine (TDI)
| 1 - the valve of system of recirculation of the fulfilled gases 2 - to a vacuum box of regulation of pressure of the given air At a turbocompressor. 3 - to a vacuum box for the gate of the inlet pipeline 4 - the switching valve for the gate of the inlet pipeline The gate of the inlet pipeline reduces breakthroughs at an engine stop. At the AGR engine is established not always. 5 - the pipeline from a tee –7– 6 - the valve of adjustment of system of recirculation of the fulfilled gases |
7 - tee 8 - the electromagnetic valve of restriction of pressure of the given air 9 - backpressure valve 10 - from the amplifier of a brake 11 - air filter 12 - backpressure valve 13 - vacuum pump 14 - vacuum tank |
ATTENTION
Fuel pump of high pressure
| 1 - bolt, inhaling moment: 20 - N of m + ј turn (90 °) Surely replace. 2 - TNVD cogwheel 3 - nut To turn off it is not allowed. 4 - connecting union, 25 N of m For the giving pipeline, from the fuel filter. 5 - TNVD 6 - valve of interruption in supply of fuel, 40 N of m 7-connecting union For the returnable pipeline. 8 - returnable pipeline To the fuel filter. 9 - nut, 25 N of m 10 - pipelines of high pressure, 25 N of m 11 - connecting union, 45 N of m 12 - bolt, 25 N of m 13 - nozzle The nozzle of the third cylinder has the sensor of movement of a needle. |
14 - bolt, 20 N of m 15 - collar 16 - support 17 - heat-shielding consolidation Surely replace. 18 - bolt, 10 N of m 19 - valve of the beginning of injection of fuel 20 - grid 21 - sealing ring Surely replace. 22 - bolt, 25 N of m 23 - injection regulator cover 24 - the plug with a nut 25 - console 26 - bolt, 25 N of m |
Here TNVD directly injects fuel into the combustion chamber, namely, into a cavity in the piston. At the same time TNVD creates pressure of 900 bars and injects fuel into two steps.
Thanks to mnogosopelny nozzles and the two-spring holder of a nozzle at first the preliminary injection of a small amount of fuel which, burning down, creates favorable conditions for injection of the main amount of fuel is made. Such process of injection provides the soft and silent combustion similar to vortex-chamber combustion. The amount of injectable fuel is regulated by the electronic monitor. The advantage of such injection consists in decrease almost by 20% of fuel consumption. As the operating parameters of process of injection signals of various sensors are used. Treat them:
– The pedal sensor giving the monitor information on position of the accelerator pedal. The gas drive to TNVD is absent.
– Speed sensor.
– The sensor of movement of a needle at a nozzle. Thanks to this sensor the beginning of injection is defined and process of injection depending on loading and the speed of the engine is regulated.
– The sensor of pressure of the given air.
– The sensor of temperature of the given air.
– Sensor of temperature of cooling liquid.
– Fuel temperature sensor.
– A potentiometer of movement of the regulating gate. Signals are used by the monitor as feedback for exact positioning of the regulating gate in TNVD which is an indicator of the valid amount of injectable fuel.
For quality achievement of combustion of fuel the soaking-up channel is executed so that air on the way to the combustion chamber received a vortex trajectory. Owing to higher starting properties in a cold condition of the engine with direct injection preliminary heat is required only at a temperature below -10 °C.
Before getting to TNVD fuel passes through the fuel filter. In the filter fuel separates from water and pollution. Therefore it is important to delete water from fuel and to make timely replacement of the filtering element according to the plan of maintenance.
TNVD does not demand service. Details of the pump are greased with diesel fuel. The pump is given to rotation by a bent shaft through a gear belt.
Prevention: At work with fuel system of the diesel engine it is necessary to observe a security measure and purity.