7-8-toplivosnabzhenie-dizelnogo-dvigatelya-bazovaya-konstrukciya.html

7.8. Топливоснабжение the diesel engine – a base design

Contrary to petrol engines of system of injection in diesel engines work with high system pressure. Fuel pumps, including and regulating periphery, thoroughly differ from "petrol". Technically in diesel engines distributive fuel pumps, systems Common-Rail and "pump-atomizer" distinguish line ТНВД, плунжерные. Under cowls both Mondeo with diesel engines fuel giving it is direct in combustion chambers make плунжерные distributive fuel pumps (Bosch VP30/66 кВт/90 h.p.; Bosch VP44/85 кВт/115 h.p.) on pressure head pipelines and through atomizers with six apertures. The fuel pump in DuraTorg is resulted by means of a duplex chain from a cranked shaft.

Distributive ТНВД

Giving and fuel tap is made separately.

On the top party of the pump the electronic block of management of the pump (PCU) settles down. It uses the information of the gauge of an angle of rotation, and also the block of management of transmission (РСМ) and processes it for generating of operating signals for the electromagnetic valve of a high pressure and system of regulation of the beginning of giving of fuel.

Identical lengths – pipelines for fuel giving to atomizers

Fuel arrives to atomizers on pressure head pipelines of identical length. Nozzles are connected by tightening screws to a head of the block of cylinders. Copper condensing rings protect their ends from direct contact to surrounding details. Replacement of condensing washers usually is made after each dismantle of a nozzle.

Fuel giving

Atomizers Mondeo have rather thin design (штифтовая an atomizer). The direction of injection from six apertures is focused approximately in the centre on specially профилированную a cavity of the chamber of combustion in the piston in the cylinder. In 85-KW-engine other variants of atomizers in comparison with 66-KW-engine are used. Atomizers are differently calibrated that leads to various speeds of passage of fuel.

Electronics and mechanics

2,0-litre DuraTorg-DI-engines Ford work with modern regulating technics. Their blocks of management of transmission (РСМ) use the 32-bit tyre and the CAN-tyre for data transmission.

In detail – management of system of injection DuraTorg-DI

Gauges and актуаторы under a cowl of engine Mondeo with DuraTorg-DI 85 kw

The block of management of transmission (РСМ/PATS it is integrated): «the Central director's panel» control systems of engines DuraTorg-DI settles down sideways behind a lateral covering in space for feet in front on the right. The onboard computer with 104 codes processes current volume of the data from various zones of the engine and compares them to the fixed parametres established at factory. For the system analysis at stations Ford exclusively diagnostic device WDS is used. Its connection is made by means of a 16-polar diagnostic socket (DLC) in a motor compartment.

The temperature gauge of a head of the block of cylinders (СНТ): the SNT-GAUGE is from outside transmissions in a head of the block of cylinders. It does not carry out measurements of temperature of a cooling liquid, as usually in old engines Ford, and actual temperature of a head of the block of cylinders. Its signals influence injection volume, the injection beginning, frequency of rotation at idling, managements of candles накаливания, EGR-system, and also indication of temperature of a cooling liquid and management of the radiator fan.

The item gauge of a cranked shaft (СКР): the SKR-GAUGE registers is inductive exact angular position of a cranked shaft, and also current frequency of rotation of the engine. Its signals are significant for volume of an injected gas mixture and the injection beginning. The gauge settles down sideways on a transmission flange.

The gauge рециркуляции the fulfilled gas with the valve (EGR/only the engine of 66 kw): this gauge of position transfers on РСМ the information on current position of the EGR-valve. It forms separate constructive knot with the valve.

The gauge of absolute pressure in the inlet pipeline with the gauge of temperature of inlet air (T-MAR): It is in the soaking up pipeline between a cooler наддувочного air and an inlet collector and performs from the case work of the gauge of absolute pressure in the inlet pipeline and the gauge of temperature of inlet air. The T-T-gauge minimises taking place losses of capacity at movement on mountain district and inclined sites of roads thanks to that he instantly establishes a current working condition of the engine at idling and full loading. Measured value is barometric pressure in the inlet pipeline. This data writes down and processes РСМ as basic pressure for corresponding pressure in the inlet pipeline at various conditions of loading.

To consider influence of temperature on density наддувочного air, the IAT-gauge registers temperature наддувочного air. Its signals uses РСМ for reception of correcting parametres at calculation of pressure of pressurisation. In such union the T-T-gauge gives the information on РСМ on which basis the volume of air weight, наддуваемой in the engine pays off. All it makes impact also on quantity of injected fuel and system EGR.

Only for the engine on 85 kw

The 85-KW th a variant uses the MAR-SIGNAL in addition to management of pressure of pressurisation in variable турбонагнетателе. As soon as the actual measured value deviates from set on the parametrical characteristic in РСМ values, РСМ regulates pressure of pressurisation by means of the corresponding electromagnetic valve.

Air flowmeter (MAF): the MAF-gauge works by a principle нагретой a wire. It "is inserted" into an air pipe behind the air filter and basically operates EGR-system.

The gauge of position of a pedal of an accelerator (АРР): to change capacity of the engine according to position of a pedal of an accelerator, РСМ is guided by the data about ARR-GAUGE position. Basically this gauge works similarly to a potentiometer which by means of three sliding contacts measures angular movings of a pedal of an accelerator. At refusal of two contacts the engine works only on the raised turns of idling. The switch of idling and the foot switch is built in the ARR-GAUGE. РСМ compares a signal from the switch of idling to a potentiometer signal on reliability.

The gauge of pressure of air (BARO/only for the engine of 85 kw): the Gauge settles down in salon, in the left arm of an intensifying element of a forward rack, behind a guard of devices. In order to avoid a black smoke it supplies РСМ with current values of dominating pressure of air. On the basis of sent signals the onboard COMPUTER corrects pressure of pressurisation and actual volume of injection.

The switch of brake illumination and brake pedal (ВРР): the Signal from the switch of brake illumination includes brake lanterns and "supervises" the ARR-GAUGE (reliability check): at any process of braking frequency of rotation of the engine automatically falls to idling level.

Mondeo with system of regulation of speed

Not to stop system of regulation of speed already at "insignificant" pressure upon a brake pedal, upon the foreground the VRR-SWITCH with a long way of operation acts. In the beginning its signal arrives on the onboard COMPUTER which deduces system of regulation of speed from "game".

The switch of position of a pedal of coupling (СРР): This element signals РСМ about that, is available or there is no coupling. By pressing a coupling pedal the quantity of injected fuel quickly decreases to avoid engine jerks.

Mondeo with system of regulation of speed

In a combination with system of regulation of speed the second SRR-SWITCH is established. Its contacts by means of brake lanterns are connected with weight. In position of rest contacts are closed. Only at the pressed pedal of coupling the switch opens, therefore the system of regulation of speed does a pause in the work.

The electromagnetic valve рециркуляции the fulfilled gas (EGR): By means of the EGR-valve soaked up fresh air mixes up with a part of the fulfilled gas. It reduces the maintenance of oxides of nitrogen in the fulfilled gas. Mixing process operates РСМ: the electromagnetic valve will transform its clock signals to precisely set operating lowered pressure for mechanically working EGR-valve.

The electromagnetic valve of pressure of pressurisation (only in the engine of 85 kw): That optimal to co-ordinate pressure of pressurisation турбонагнетателя with a condition of loading of the engine, in 85-KW th the engine the supercharger with rigid directing blades and байпасным regulation, and the version with adjustable blades works not. That these blades constantly were in the certain position depending on a condition of loading of the engine, the electromagnetic valve of pressure of pressurisation receives clock signals with corresponding spatial parametrical characteristic РСМ. It will transform electric clock signals to the set operating lowered pressure which influences a component of low pressure for adjustment of pressure of pressurisation.

The electromagnetic valve заслонки the inlet pipeline: as soon as the engine stops, РСМ sends on the electromagnetic valve заслонки the inlet pipeline a corresponding signal. On its basis the valve operates according to a vacuum dose on заслонку the inlet pipeline and closes it for some seconds.

Having merged back in a fuel tank – superfluous fuel

Concerning quantity of fuel it is possible to tell that in systems of injection DuraTorg-DI constantly plies more fuel, than it is actually necessary. Atomizers also inject not all quantity of fuel into combustion chambers: superfluous fuel among the other is intended and to grease and cool moving details of the fuel pump and atomizers.

In engine DuraTorg-DI Mondeo there is, however, a function which prevents full опорожнение and by that "dry" work of installation. As soon as the solar oil stock will reach two percent, РСМ establishes the fuel pump on zero giving. Advantage: it is necessary to "air" usually Mondeo only after replacement of the fuel pump, otherwise it for you will execute a starter on the long period of start-up.

That at the working engine fuel could "travel" on system, diesel engines have accordingly submitting and drain pipelines. As well atomizers are integrated into them: they have a drain branch pipe and are with each other in contact by means шлангопровода (the pipeline for oil plum). From right concerning a direction of movement of an atomizer (the cylinder 1) fuel flows on the drain pipeline back to a fuel tank. The drain aperture of an atomizer of the fourth cylinder according to the given principle is condensed запорной with a stopper.

System of regulation of the engine

An engine food – so gets fuel to atomizers

The fuel pump forces on the closed system of pipelines (submitting and drain pipelines) diesel fuel from a tank through the fuel filter to ТНВД. In existing distributive ТНВД work of the fuel pump carries out шиберный the pump. It is in a round aperture directly in the pump case. As here it is a question of the soaking up pump and the compressor the same pump also transports diesel fuel in own zone of compression distributive ТНВД. Only in engine DuraTorg-DI of 85 kw «diesel goods turnover» in system supports additional electric топливоподкачивающий the pump, the maximum volume makes here 160 litres/hours.

"Cleaner" before ТНВД – the fuel filter with the adjusting valve working depending on temperature

The filtering element settles down in well accessible to works on servicing a place at the right punch of an amortisation rack under an engine cowl. In drain топливопроводе there is a regulating valve working depending on temperature. Advantage: superfluous diesel fuel gets now back to a fuel tank, if its temperature above 31 °С. As soon as fuel will be cooled to 15 °С, the valve brings superfluous fuel directly to the filter and supports thereby fuel to–35 °С without «additional warming up» in a fluidity.

Together with connecting pipelines the adjusting valve forms the separate block. A lack: in the service centres it is necessary to replace completely the valve together with pipelines. As, however, and the fuel filter – it cannot neither be dehydrated, nor to wash out: therefore it is necessary to replace the valve regularly, therefore for foresight from «water damages» take with itself in travel and distant trips on southern plains such spare element.

The standard only in DuraTorg-DI 85 kw – a fuel cooler

In comparison with VP 30 in ТНВД VP 44 the high pressure is realised more. Naturally this fact defines growth of temperatures of circulating diesel fuel. That temperature level even at high external temperatures was not beyond, the part of the drain pipeline is structurally executed in quality of "a cold pipe». It cools flowing down fuel to 10 – 12 °С.

Raises hydraulic efficiency – the fuel pump of a high pressure

In quality «раздатчика instructions» for all functions of pumps the management block (PCU) which is in "electric" contact to periphery of the engine and an accelerator pedal is used located with the top party of the pump. Bosch VP 30/VP 44 in Mondeo cope with the help of the electromagnetic valve of a high pressure which loads axial pistons. The valve works in a variable mode, opens and closed strictly according to the parametrical characteristic, хранимой in PCU.

However, the giving beginning in Mondeo already needle the mobile gauge any more does not order – the command «Go» directly proceeds from the block of management of the pump and gets through the electromagnetic gauge of a high pressure to hydraulic system. The beginning of giving of fuel is defined on a point of the moment of closing of the electromagnetic valve, the giving end is set by a point of the moment of opening, and the fuel volume is defined by a time interval during which the electromagnetic valve of a high pressure is closed.

Distributive ТНВД VP 30

The electromagnetic valve of a high pressure

Work distribution – a rotor of the gauge of operating impulses

That each cylinder in correct sequence and by the necessary moment of time has been fed", the rotor of the gauge of operating impulses and the gauge of an angle of rotation operate accordingly as the distributor. The rotor of the gauge of operating impulses is connected directly to an engine power shaft, and the gauge of an angle of rotation is strongly connected with a roller ring. As soon as the electromagnetic valve directs an injection regulator, the roller ring and by that the gauge of an angle of rotation in position"early"or"late"turns. The rotor of the gauge of operating impulses has on each cylinder« a hollow between teeths ». Desired"offer"for the gauge of an angle of rotation – it scans hollows and sends the corresponding information on PCU for the subsequent use. These signals are a basis for current angular position of a cranked shaft, current frequency of rotation ТНВД and system of regulation of the beginning of injection.

Rotor of the gauge of operating impulses and the gauge of an angle of rotation

Does quick a cold diesel engine – the device for start-up of the cold engine

The device for start-up of the cold engine serves the same purpose, as the automatic device for gas mixture enrichment at start-up in petrol engines: these both systems help cold motors at a transitive stage. Thereby, however, similarity on it comes to an end. Though the device for start-up of the cold engine puts the use depending on dominating temperatures, nevertheless it does not reduce, for example, air giving in cylinders, and at once establishes a point of the moment of injection in a direction "early". Thereby the sprayed fuel has more time to ignite in compressed air and штифтовыми candles накаливания – the engine is started «more obediently and more exactly». Besides, the device for start-up of the cold engine increases frequency of rotation at idling a little and – depending on engine temperature – warms up for a known time interval. It reduces noise of the engine with direct injection of fuel, improves quality of idling and reduces issue of carbon in warming up.

Dispersion of diesel fuel – double spring atomizers

Atomizers are exclusively an ultimate authority of diesel system of injection. They spray fuel under a high pressure in the combustion chamber. To minimise noise arising at combustion and a little to "tame" explosive pressure jumps in cylinders, atomizers Mondeo are equipped with two springs. The course of the first spring is established thus, the atomizer needle already at 222 – 230 bar easily rose from the saddle. Thanks to it the small amount of fuel gets to the combustion chamber and ignites.

«Preliminary injection» is intended for smooth growth of pressure of combustion as it operates, somewhat as "match" during several milliseconds before the basic injection which occurs at 380 – 398 bar. In Mondeo these both processes of injection "smoothly" pass each other, the electromagnetic valve of a high pressure receives for this purpose the second operating impulse. After that the spray needle completely rises and lets in the basic volume of fuel through six apertures from injection system a cavity of the chamber of combustion. Caused by "preliminary combustion» air turbulence carries away fresh particles of fuel and almost homogeneous and easily combustible dizelno-air mix is formed. Influencing needles of sprays high elasticity of a spring interferes with that pressure of combustion has not answered with return blow on fuel system. As all volume of fuel is never injected, superfluous fuel flows down – as is already mentioned above – on the drain pipeline back in a fuel tank. Set time between the beginning of injection and the ignition moment makes 0,002 seconds. Thus it is clear, what even the slightest infringement of functioning, for example, "jamming" of a needle of a spray, will discompose physically balanced process of combustion. Capacity losses, the black smoke or strong «needle noise» (even at the heated-up engine) are doubtless and "heard" signs of that the diesel engine is in such "condition".

Business for experts – repair and correction of diesel system of injection

The skilled fan can find out a separate defective atomizer independently. For this purpose it is necessary to listen, as the engine idling "mutters", and at all atomizers of a number quickly to release накидную a nut of the pressure head pipeline. If for an atomizer, despite the removed pipeline, frequency of rotation remains to a constant the spray or the valve of the corresponding cylinder is considered defective. Damaged распылительные atomizers, besides, can be distinguished on following symptoms:

Regular defects in candles накаливания, Constant black smoke from an exhaust system, The raised expense, Often overheated engine, Rigid noise of combustion (loud movement of a needle), Recession of capacity, The over-expenditure.

If in your diesel Mondeo you have established presence of the above-stated troubles, look for a repair truck and on a place inform experts on the problems. They can give you the information on suitable counter-measures.

Dismantling of a spraying atomizer – charge this business to the expert

Without special check of a spray it is possible to judge its functioning only superficially. Naturally, it is possible to find out external damages or strong pollution. Direct deterioration, certainly, takes place in an atomizer, on a needle, in the case of a spray or a clamping spring. Here again you have not enough possibilities for corrections for for this purpose it is necessary to have the special test device with which help it is possible to "wring out" a nozzle, to establish «a stream picture» and to correct pressure of injection. In most cases it will be better to replace a spray completely. If you all the same are going to disassemble this detail its "interiors" should not be left for long time "opened" on a workbench: the surfaces of a needle of a spray processed with a split-hair accuracy and atomizer cases are very sensitive to dust and rust influence. Always establish new atomizers with new sealing rings in a head of the block of cylinders. The moment of an inhaling of the holder of an atomizer makes 24 Н·м.