Inspection Angle (UUs) and Load In Diesel Engine

(Note: This article is general metering and is not tied to any car brand)

It is strange to hear the opinion of a specialist, a diagnostic, the repairman that injection advance angle in a diesel engine changes only depending on the frequency of rotation crankshaft.

Undoubtedly, the speed of rotation of the crankshaft is one of the main parameters (characteristics), accounted for when organizing combustion of the fuel-air mixture in the engine combustion chamber of both diesel and gasoline.

From the rotational speed of the crankshaft - the speed of the movement of the piston in the engine cylinder - the amount of working fluid in the engine combustion chamber and its temperature depends.

With an increase in the rotational speed of the crankshaft, the absolute durations of the flareliest delays (in milliseconds) are reduced, but the relative durations in degrees of the crankshaft turnover increase. It is not necessary to forget about this moment as the injection delay (time between the beginning of the fuel supply by the pump and the injection of fuel into the combustion chamber).

The higher the speed of rotation of the crankshaft, the earlier you need to be injected into the combustion chamber fuel and vice versa.

Is it possible when organizing combustion in the diesel engine cylinders to limit itself to the adjustment of the crankshaft rotation frequency? Or maybe there is something else that requires our attention?

Attention requires the features of mixing and burning in the combustion chamber of the diesel engine.

First of all, diesel refers to engines with internal mixing formation and fuel injection at the end of the compression tact. On the mixture is allocated to only 1 - 3 ms or 12 - 25 ° at the corner of the rotation of the crankshaft of the engine. It is 20 - 30 less than in the engines with external and internal (injection in the intake tact) mixture formation (most gasoline engines Work on homogeneous - homogeneous fuel-air mixtures).

The diesel engine is capable of working on depleted mixtures with an excess air coefficient on idling And at zero load \u003d 10. The value for dyssets with a superior at full load is within .. \u003d 1.15 - 2.0. That is, the composition of the fuel and air mixture varies from very poor to the poor.

Thanks to the heterogeneous (inhomogeneous) composition of the fuel-air mixture (TVS) in the combustion chamber of the diesel engine, there are areas with a rich and poor mixture, areas where air or only diesel fuel. And, of course, there are so necessary for timely ignition of the field of the fuel-air mixture (TVS) with a stoichiometric composition. That is, a whole set of mixtures.

These conditions are valid for both engines with separate combustion chambers and diesel engines with direct (straight) injection. It is the inhomogeneous composition of the fuel-air mixture (TVS) that allows a diesel engine to work on depleted mixtures.

On the other hand, the same inhomogeneous composition of the mixture (TVS) with smaller values is one of

the main disadvantages of diesel engines are the impossibility of complete and smokeless combustion of the fuel and air mixture (TVS).

In addition to visual confirmation written, I want to show you with the diagram of the main processes occurring in the combustion chamber of the diesel engine.

It will not be about the "explosions". We will talk about managed and controlled events that occur in time in parallel and consistently. You need to see this schedule and remember. Temperature changes are especially important.

Figure 1 presents a typical chart of changes in the press engine cylinder and the average temperature T of gases in the function of the angle F, shows the nature of the change in the amount of the amount of the amount of fuel combustion, the rate of its supply, the coefficient of active heat generation X and the heat generation rate

For clarity and simplicity of perception, the diagram is drawn in deployment. We need to consider it from left to right.

The piston moves to the upper dead point, the pressure and temperature of the working body grow, and if there is no fuel injection at point 1, then when the piston moves from the VMT to NMT, the pressure and temperature will decrease (designated by the dotted line).

Fuel supply starts at point 1, at point 2 the first flame languages \u200b\u200bappear.

This periodic delay of ignition and it is characterized by the fact that the piston is approaching the VMT, the volume of the combustion chamber is reduced, the temperature and pressure grow.

Fig. one

The amount of fuel Art during this period is slight, but at high speed

The temperature in the combustion chamber (due to injection) is somewhat reduced, and accordingly the pressure of the compressible air due to the cost of heat to heating and evaporation of fuel.

From point 2 to point 3 - the phase of rapid combustion

It is characterized by the fact that the piston "translates" the VMT, that is, the volume of the combustion chamber is first reduced, and then begins to increase.

Pressure when the piston movement from the NTT reaches the maximum values, the temperature continues to grow. This period characterizes the "rigidity" of the combustion process in the diesel.

During this period, the main amount of fuel st is injected into the combustion chamber with the maximum possible speed, The heat generation rate increases sharply and reaches maximum values, and then begins to decrease. The coefficient of active heat dissipation X is growing.

From point 3 to point 4 - Slow burning phase

It is characterized by the fact that the piston moves from the NMT to the NMT, the volume of the combustion chamber increases. The pressure p expanding gases decreases, and their temperature T reaches a maximum.

In this phase, fuel injection ends.

At the end of the delayed burning phase, there is some increase in the heat generation rate associated with an additional turbulus of charge at the beginning of the downstream piston. The coefficient of active heat dissipation X is growing.

From point 4 and before the discovery of the exhaust valve - the trigger phase

It is characterized by the fact that the piston moves to the NMT - the volume of the combustion chamber increases, pressure and temperature decrease. The coefficient of active heat dissipation X is stabilized (the coefficient of active heat generation X characterizes the relationship between the combustion processes and the use of the highlighting heat - see special literature).

The burning is a complex physicochemical process that flows in the gas phase. That is, first liquid fuel should turn into steam, and then as a result of chemical reactions, turn into a combustible mixture capable of making mechanical work.

The liquid fuel injected into the combustion chamber is crushed into small drops, it is distributed over it, heats up and evaporates. This is the essence of physical processes, and they proceed with the absorption of heat.

Oxidation processes are multi-stage and are chain. As a result of chemical reactions (proceed with heat release) a number of active intermediate chemical products (peroxides, aldehydes, alcohols, etc.) are formed.

Self-ignition is end result development of these reactions.

True sequence of elementary stages in oxidation and burning reactions motor fuel It is not yet fully studied, but the dependence of their velocities on temperature and pressure is characteristic of most chemical reactions.

The above does not mean at all that physical and chemical processes are carried out consistently. Everything happens almost simultaneously. The chemical component of the combustion process is somewhat lagged out due to the fact that first, it should appear in the combustion chamber liquid fuel. Smaller drops evaporate the first. As a rule, these small drops are grouped along the edges of the torch of the injected fuel injector. The dynamics of the fuel torch development in the mechanical system is such that it cannot instantly occupy the volume of the combustion chamber in the engine cylinder, first a slight amount of fuel under high pressure injected into the cylinder. This contributes to the law of fuel supply (each phase of burning its amount of fuel), expressed constructively in detail mechanical Systems Injection. The injection of diesel fuel in these systems is carried out continuously.

In distribution pumps with solenoid valves, the fuel injection is possible. Pump-nozzles of passenger cars provide pre-injection using a hydromechanical drive.

Rechargeable diesel fuel injection systems are advantageous from all previous systems by the fact that, in addition to preliminary and main injections, they also provide additional. In contrast to the two-stage injection used earlier on some brands, under continuous fuel supply in battery systems, the pre-injection is separate.

But now is not about it.

So, a preliminary amount of fuel at high speed is injected into a heated dense gas environment, collapsed and evaporates. Having a small kinetic energy, it is small (1-4 mm 3) the amount of fuel is not able to break through the dense air and remains in the area of \u200b\u200bnozzles and glow plugs. In the process of mixing formation, zones are always formed, where x \u003d 0.85 ... 0.9. These zones serve as centers of ignition of the surrounding more depleted mixture.

By the time of the main fuel injection, the fuel injected into the combustion chamber is predetermined, already ready for ignition and flammifies. In the combustion chamber, pressure and temperature are sharply rising, which contributes to a significant reduction in the delay in the inflammation of the main injection. Diesel fuel Under high pressure at the main injection, possessing greater kinetic energy, it makes its way through an increasingly sealing (already burning) gas environment to all the zones of the combustion chamber removed from the nozzle.

The movement of the air defined by the design of the intake manifold, the movement of the piston in the compression tact is repeatedly enhanced by moving on the ignition points in different directions by expanding combustion products. Air mass in turbulent motion, pulsating gas streams permeate fuel torches (holes in the sprayer can be from 4 to 10; in most cases - 6h-8.) Under these conditions, the fuel that continues to be injected, burns almost instantly.

The pressure in the cylinder increases in a timely, smoothly and without noise.

The speed of burning liquid fuel is determined

Speeds of its evaporation and mixing the resulting vapors with air

This is true for engines. internal combustionworking on lightweight and hard forms of liquid fuel.

Fuel injection into the combustion chamber of the diesel engine is entitled

the drop in temperature (fuel evaporation is accompanied by heat absorption).

The magnitude of the temperature drop depends on the load.

This is especially noticeable in transition modes associated with increasing load.

On page 58 of the first edition of the Bosch book "Management Systems diesel engines"(Translation from the German publishing house" Behind the wheel ", 2004 year) shows the characteristic of the start of injection, depending on the rotational speed of the crankshaft and the load on the engine a passenger car When cold start and operating temperature.

1) cold launch (<0 °С);

It is easy to see that at the speed of rotation of the crankshaft 1000 rpm, with partial loads (3) and full load (2), its corresponding load, fuel sows is required. That is, more fuel must be injected into the engine combustion chamber earlier in order for the peak of pressure expanding when combustion gases "hold" for NMT.

The cold launch of the diesel engine is not much different from gasoline. The lack of heat in the combustion chamber and, in connection with this, the bad conditions for evaporation of diesel fuel are compensated by its greater cyclic feed. More fuel (the desired concentration of vapors due to increased fuel supply), its earlier injection (1) and air heating systems - regular functions of all without exception of cold start acceleration systems.

Thus, when fuel injected in compression tact in the combustion chamber, temperature changes are observed.

There is a need to adjust the devices of diesel fuel.

When testing high-pressure fuel pumps on the stand, you must use tables or cards of specified control parameters. These include the conditions under which the TNVD tested must comply with tabular data.

Functions of the TNVD type VE that are subject to attention.

The health of the elements responsible for high pressure;

The health of the elements responsible for pressure in the TNVD;

Health of the elements of ahead of ahead;

Pump performance;

Work frequency controller.

These indicators are considered at specified rotation frequencies and full load.

In 1978, a disconnected adjustment device for the start of supply start-up appeared on the VE type.

Later, correlates of the LFB type appeared (a device for changing the start of the fuel supply, depending on the load). These devices are designed to correct the start of the fuel supply, depending on the load to reduce noise and especially og emission.

What does the word correction mean? Correction - Amendments to the action of measuring instruments, regulators, etc. Depending on the change in the conditions of their operation.

When checking the TNVD, the traffic proofreaders and other reflective devices are checked.

Interesting results can be obtained by comparing the pressure in the TNTD type VE with the proofreader by load and without it on the minimum idle speed. So, with a proofreading pressure on the pump at idle -1.5Ch-2.0 BAR, and without a corrector - 2.5H-3.8 BAR. That is, the piston of the high-pressure fuel pump fuel pump without a corrector is already in the "earlier" position, calculating the increase in the cycle fuel supply.

You know that the pressure in the TNVD type VE affects the change in the UIs in the dynamics. The higher the frequency of rotation of the shaft-the higher the pressure in the fuel pump and the greater the distance moves the hydraulic piston of the ahead of the automatic ahead - before injection.

The main functions of the corrector

Increase pressure in the pump at a start;

Increase pressure in the pump with an increase in the load;

Reducing the pressure in the pump with a reduction in load.

The pressure in the TNVD varies within 1 H-2 BAR.

It allowed:

Provide earlier injection of diesel fuel when starting (thereby improving it);

Reduce pressure on the pump at idle and, as a result, reduce the noise of the diesel engine in this mode;

Variate between the provisions "earlier" or "later" depending on the load. With a decreasing load (from full to partial) and with the constant position of the fuel supply pedal, the start of the feed is shifted to the "later" position. With an increase in the load - to the "earlier" position. And, as a result, the operation of the engine becomes softer, and the toxicity of ogs in partial loads is reduced.

I admit honestly that until the fourth teach of the diagnostacles did not think about the peculiarities of the device for the advanced control coupling of the injection rapid TNVD. It seemed to me a natural understanding that the fuel injection advance angle depends on many factors. Including from the speed of rotation of the crankshaft of the engine and the load. With a more careful consideration of the issue of regulation of UOV, the question surfaced: How exactly is this regulation? Indeed, in the construction of the row TNVD there is only a regulator of the speed of rotation. The device for adjusting the angle of ahead of injection is made beyond the limits of the pump.

So here's about the coupling ... the coupling is like a coupling, nothing special: springs, cargo. Consists of two rolling poles with one center with one center (OM engine 602.911). And it works simply: the higher the speed of rotation of the crankshaft-shaft, the farther from the center of the coupling moves loads and rotate the second half of the coupling (along with the TNVD shaft) in the direction of rotation - before the fuel injection.

I thought about the corrector, but I did not find places that are convenient for its installation in this clutch. A difficult thing is an event in a row TNVD - to organize the adjustment of the loads by load. But with the advent of an inline TNVD with an additional (regulating) sleeve, it became a reality.

"... With the help of electronics, it is possible to introduce an additional (in comparison with standard TNVD) the correction of the operation of the diesel engine. ... "(p.177, the first edition of the Bosch Book" Diesel Engine Management Systems ", translation from the German publishing house" driving ", 2004).

With these examples, I want to say that it is constructively in elements of simple mechanical high-pressure fuel pumps that are responsible for regulating Us in the dynamics, temperature fluctuations in the engine combustion chamber, depending on the amount of fuel injected into it. At one time, such solutions were quite satisfied with car manufacturers and buyers.

Time goes - everything changes.

I believe that we consider all the processes occurring in the engine combustion chamber, depending on the rotational speed, are necessary separately from the processes occurring when the load changes.

To understand the essence of what is happening. It is impossible to divide these processes.

Changing the amount of working fluid entails a change in the rotational speed of the crankshaft. Even in zero load mode.

On page 58 of the first edition of the BOSCH book "Diesel Engine Management Systems", translation from the German publishing house "driving", 2004, it is said: "... The optimal values \u200b\u200bof the injection advance angles are changed depending on the engine load, which requires regulation. The required values \u200b\u200bare set separately for each type of engine and form a field of characteristics that determines the moment of starting the injection depending on the load on the engine, the rotational speed of the crankshaft and the temperature of the coolant ... ".

Thirty-eight years ago it was said about the adjustment of the UI, depending on the rotation frequency of the crankshaft and the load. The possibilities of organizing the optimal combustion of the fuel-air mixture in the engine cylinders at the time were completely different than today.

Vladimir Belonosov

The first and most important difference between the diesel unit from gasoline is the ignition system or, in other words, how the fuel is flammable in the engine.

In the motor that uses diesel fuel, ignition comes from the fact that the diesel engine is in contact with the air heated from compression, which accumulates inside the motor cylinder.

When they talk about the adjustment of the ignition system in the diesel engine, under these words, the process of changing the fuel injection angle is supplied to a specific point - at the very end of air compression.

If the angle is set incorrectly and significantly different from the required parameters, the fuel injection will occur in a non-time, which will prevent the normal operation of the engine and can cause the most sad effects of the consequences.

Also incorrectly exposed angle leads to incomplete combustion of fuel in the cylinders.

There is such a concept as earlier or later ignition.

In other words, the ignition system in the diesel engine is one of the most important components. For the supply of fuel in such an engine corresponds to a special high pressure pump - TNVD.

This device together with nozzles and determines the dosage of the diesel fuel, which is supplied to the motor.

Often the driver has to face the fact that it is necessary to set ignition with his own hands, for example, if you need to replace the timing belt.

In the second case, the need to adjust the system appears in the case of dismantling the fuel pump.

With the analysis of the fuel equipment, the first thing is necessary to remember all tags. This can be easily done with a marker or paint. The main thing is to put the labels exactly where they are necessary.

Thanks to this, the assembly of the ignition system and the fuel system will be very simple, and it will also provide an opportunity to avoid complications with the launch of the engine.

Adjusting the ignition system can be carried out in different ways.

The first method is the installation of the angle exactly on the marked marks. The second method is a gradual selection of the correct position of the adjustment coupling.

The article will consider both methods.

When independent installation of the angle, it will be necessary to shift the pump for fuel supply. This method is more applicable for diesel engines with mechanical fuel supply equipment.

In order to adjust the injection advance, you need to smoothly rotate the high pressure pump drive clutch around the axis.

There is another option - this is the rotation of the camshaft pulley in relation to the hub. Such adjustment options are suitable for structures that do not have the hard attachment of these parts.

So, adjusting the ignition on the unit, the first thing you need to get to the rear of the engine, find the flywheel there and if required, release it from protective casing. After that, it is necessary to find a stopper and install it in a special slot, but still do not stop Mokhovik.

When this is done, with the help of a tool (key) you need to start scrolling the flywheel. When rotating, the crankshaft will be spinning together with it. You need to rotate until the flywheel does not stall.

After his stop, you need to pay close attention to the pump shaft. If after rotating the scale on the drive clutch occupied the position from above, it means that the label installed on the fuel pump flange is combined with a zero mark on the drive.

If the labels are combined, you can safely twist the fasteners bolts.

However, if after all the procedures they disagree, then it is required to raise the flywheel stopper again and continue the scrolling of the crankshaft, controlling the position of the drive on the drive.

If everything is done correctly, then after tightening the fastening bolts, the flywheel is released from the stopper and rotate the crankshaft 90 °. After that, the stopper is placed again in the groove.

Now you can set the handwheel protection back and try to start the engine. If the motor started working, you need to analyze how it does it. If everything was performed without errors, the engine will work very gently, without interrupting.

With the second method of adjusting the ignition, the angle is exhibited by an experimental way.

Suppose if the motor does not work, then the pulley of the high pressure pump slowly begin to scroll on a certain amount of teeth with respect to the timing belt. After this operation again try to start the motor. If it works calmly, without knocks, then everything is fine.

If there is an explicit knock, you can try to twist the pulley. The appearance of the smoke engine when starting the engine will mean that a late arbitrariness is set.

In this case, you need to turn the pulley exactly one to the tooth towards the rotation.

After each stage of adjustment, you need to try ignition and evaluate its operation.

The above methods of exposing the fuel injection angle on the diesel engine for many car owners are not difficult, however, if all of the above presents difficulty for you, contact a good motorist and it is not necessary to work in the car service.

Fuel in the engine burns not instantly. Diesel engine has the best power and economic performance indicators if fuel combines when finding a piston near the top of the dead point.

To ensure that this requirement is performed, you need to make the fuel injection served him with ahead, Before the piston arrival in the upper dead point.

The magnitude of the fuel supply in the diesel engine, expressed in degrees of the corner of the crankshaft rotation, call injection advance angle.

Each diesel engine, for the main mode of operation, a certain injection advance angle. When changing the angle of ahead, power and economic indicators are reduced Diesel.

The magnitude of the injection ahead depends on:

• injection pressure
• chemical composition of fuel
• air temperature at the end of the compression tact
• diesel revolutions
• the amount of fuel supplied.

Optimal conditions of combustion

If fuel injected into too early when the temperature of the compressible air is not high enough, the fuel will bad evaporate And part of it before self-ignition will have time to settle on the walls of the camera. In this case, the fuel burns in part and diesel work worsen. In addition, due to the combustion of fuel gas pressure rises in the chamber that will be counter move Piston, before coming to the upper dead point.

Diesel operation worsens also too late injection. Fuel in this case burns with expansion tactWhen the combustion rate decreases, and the surface of the contact of hot gases with the walls of the cylinder increases. In this case, a lot of heat will be given to the cooling water and discharged with the exhaust gases.

So that the nozzle is injected with the desired advance, fuel pump it is necessary to serve fuel even earlier.Since from the start of the fuel supply to the pump to injection from the nozzle takes some time.

An angle on which the crankshaft will turn from the position corresponding to the beginning of the fuel supply by the pump to the position in which the piston will come to the upper dead point, call feed lead angle.

The fuel lead advance angle, more injection ahead.
In the design or its drive is envisaged device that allows you to change angle Advanced fuel lead.

For each type of diesel engine, depending on operating modes, there are suitable ahead of ahead Fuel supply.

In the intake tact, the diesel engine admits only air. In the compression tact, this air is heated to a temperature so high that diesel fuel, injected into the cylinder at the end of the compression cycle, is flammable independently. The amount of fuel in the engine is dosed using high pressure fuel pump (TNVD). The fuel is injected under high pressure through the nozzle into the combustion chamber.

The fuel injection must occur as follows:

• with precisely dosed amount of fuel in accordance with the engine load;
• during the required period of time;
• in exactly a certain period of time;
• a method that corresponds to a specific combustion process.

Fig. Diesel engine fuel supply system diagram:
1. Fuel tank; 2. Fuel pumping pump (low pressure fuel pump); 3. Fuel filter; 4. Inline TNVD; 5. Device to advance the moment of injection; 6. Regulator; 7. The nozzle holder with the nozzle; 8. Return fuel line; 9. Gallery candle with a closed element; 10. Rechargeable battery; 11. Preheating switch and starter; 12. Pressure control unit.

TNVD and a regulator connected to the control (control) toothed rack are responsible for ensuring these conditions. The amount of fuel injected in one course of the pump plunger, approximately proportional to the torque of the engine.

If the engine is used on the engine (centrifugal) revolve number control, the control rake is connected to the accelerator pedal ("gas") through the regulator.

Fig. Closed control loop for a mechanical regulator:
1. diesel engine; 2. Inline TNVD; 3. Regulator; 4. Engine turnover; 5. The amount of fuel injected; 6. Accelerator pedal; 7. The course of the control rail; 8. Pressure of the supplied air; 9. The desired number of revolutions; 10. Atmospheric pressure; 11. Torque control; 12. Feed at full load; 13. Initial number.

The electronic regulator (EDC), the accelerator pedal is equipped with a sensor connected to an electronic control unit (ECU or ECU). When the driver presses the gas pedal, then moving is converted to the appropriate stroke of the rail, taking into account the engine speed at the moment.

Why do diesel engine need a regulator?

A diesel engine does not exist the position of the control rail, which would allow the diesel engine to accurately maintain its turnover without the help of the regulator. At idle, for example, without a regulator of the number of revolutions, the engine turnover will either fall until the engine stops, or will continue to increase that, in the end, will lead to self-dissemination of the engine.

The last possibility is obliged to the fact that diesel works with an excess of air, which means that there is a lack of effective throttling of the mixture entering the engine at an increase in its revolutions.

For example, if the cold engine was headed and stayed at idle, while the initial amount of fuel continues to be injected, then the characteristic friction will soon begin to decline. The same applies to the load of the engine from the aggregates given from it, such as a generator, air compressor, TNVD, etc. This means that if the position of the control reikist remains unchanged and the rake was not pulled to reduce the amount of fuel supplied (as the regulator would have done), the engine turnover will increase more and more (due to the above friction drop) until they reach the point self-destruction. In other words, it is obligatory that diesel is equipped with a regulator of the number of revolutions. Currently, either mechanical (centrifugal) regulators or an electronic control system of the diesel engine (EDC) are used for row pumps.

Pneumatic regulators controlled by the intake manifold pressure were installed earlier on small TNVD. They had to abandon them as a result of increased regulatory accuracy and regulator requirements.

There is no doubt that when the load is applied to the engine, the TNVD should always provide the engine with a necessary amount of fuel. All row pumps have a separate plunger pair (plunger (3) and sleeve (1)), called another injection section (element), for each engine cylinder.

The plunger moves in the direction of fuel supply using a cam shaft driven by motor, and returns back under the action of a return spring. Since the plunger's course cannot be changed, the amount of injected fuel can be adjusted only by changing the effective (active) plunger stroke.

Fig. Work regulator

Plungers are equipped with an inclined spiral cutout (channel), so that the required efficient move is selected by turning the plunger. Turning is carried out using a control gear rail (5), which is in engaging with the plunger and moves longitudinally with the help of the regulator. The rotation of the plunger moves the helix (cutout) (4) to control the moment the end of the feed (also known as reset or opening the hole in the sleeve) and the amount of feed. The feed starts at the moment when the upper edge of the plunger closes the inlet (2) in the wall of the sleeve.

In the case of maximum feed (c), the reset does not occur until the maximum efficient plunger's stroke, in other words, with the maximum possible amount of fuel supplied. With partial feed (b), the reset occurs earlier depending on the position of the plunger when turning. In the final position, which is required for zero feed (A), i.e. At the moment when the engine must be stopped, the longitudinal groove of the plunger is located directly opposite the inlet. This means that the discharge chamber over the plunger is connected to the fuel trunk during the entire passage of the plunger, i.e. Fuel is not served.

There are several different spiral configurations.

In the case of a plunger only with the bottom spiral (neck), the fuel supply begins at the same point of the plunger's progress, while the end of the feed occurs before or later, depending on the rotation of the plunger. When the plunger has an upper spiral (cutout), then the start of the feed may change. There are also plungers equipped both upper and lower.

Reducing the revolution of the regulator

Each engine has a curve (characteristic) of the torque in accordance with its maximum power efficiency. Each motor revolutions is associated with this maximum torque. If the load on the engine is removed in the data of the engine speed, and the control rail is not appropriately adjusted, the engine turnover can only increase within the controlled range to the number defined by the engine manufacturer (i.e., from NV revolutions at full load to N1 - low idle speed). The increase in engine speed is proportional to the load change, i.e. The greater the reduction in the engine load, the greater the increase in engine speed.

This effect is known as the effect of reducing revolutions and refers to regulators with a decrease in revolutions. The decrease in the revolutions of the regulator mainly refers to the maximum turnover at full load (normalized revolutions) and is calculated as follows:

b \u003d (N10-NV0) / NV0 or b (n10-nv0) / nv0 * 100%

where b is the coefficient of reducing revolutions, it is also called just a decrease in revolutions); N10 - elevated idle speed (maximum); NV0 - the number of maximum revolutions at full load.

Speaking in general, a sufficiently large decrease in revolutions increases the stability of the overall contour (chain) of the control (regulator, engine and the unit-driven unit or car). On the other hand, the reduction of revolutions is limited to the working conditions. For example: from about 0 to 5% - for generator installation engines and from about 6 to 15% - for automotive engines.

Fig. Turns with full load with an appropriate idle speed control:
1. MD torque; 2. Engine speed.

Fig. Increase the revolutions for various revolutions:
1. MD torque; 2. Engine turnover; Left - a small reduction of revolutions; Right is a big reducing revolutions.

Fig. Reducing the revolutions of the R Q V V:
1. Reducing revolutions; 2. TNVD turns

The drawings introduced the following notation:

• nVU - minimum turns at full load,
• nu - any value of revolutions at full load,
• nV0 - maximum turns with full load,
• n - Low speed at idle,
• n1 - any value of idle speed.
• n10 - Increased idling (maximum).

The figure shows the practical illustration of the effects of reducing revolutions. When installing the required engine speed at a fixed value, the actual number of engine speed changes within the speed of the revolutions when the engine load changes.

Fig. 1. MD torque; 2. Engine turnover, N; 3. Rapid reduction range; 4. Maximum difference in turnover; 5. Real revisions; 6. Full load; 7. Partial load; 8. Lack of load; 9. Time T; 10. Installation speed.

Regulator functions

The main task of each revolutions regulator is to limit the maximum engine speed. In other words, the regulator must ensure that the engine turnover never exceeds the maximum values \u200b\u200bprovided by the manufacturer. Depending on its type, the regulator may have other functions, such as maintaining certain engine speeds, for example, at idle or maintain the range of speeds between low and high idling (maximum). The regulator may also have other functions and functions performed by an electronic regulator (EDC) are much broader than the functions of a mechanical (centrifugal) regulator.

The various requirements for regulators caused the development of various types of regulators listed below:
Maximum revolutions regulators. These regulators are designed only to limit the maximum turns of the engine;
Regulators of minimum and maximum revolutions.

In addition to maximum revolutions, these regulators also control low idle turns, changeable revolutions. These regulators, in addition to maximum revolutions and low idle speed, also control turnover in the intermediate region, combined controls. They represent a combination of a regulator of maximum and minimum revolutions and regulators of changeable revolutions, regulators for stationary power plants. They are designed for generator installation engines in accordance with the German standard DIN 6280. In addition to its main task, this regulator also has several other control functions. They include automatic feeding and cut-off of the additional fuel required for starting and changing the fuel supply at full load depending on the engine speed (torque control), from the pressure of the injected air or atmospheric pressure. For these tasks, additional equipment is required.

Fig. Adjusting maximum revolutions:
1. The course of the control rail; 2. Stop; 3. Full load; 4. Controlled area; 5. Full load; 6. Without load; 7. Engine turnover.

Depending on the reduction of revolutions, when the load on the engine is removed, then the maximum revolutions at full load NV0 do not reach the value of N10 (increased idle speed - maximum). The regulator configures them to this desired value, moving the control rail in the stop direction (stopping the fuel supply). The control (adjustment) in the region between NVO and PU is called adjustment of maximum revolutions. The higher the reducing revolutions, the higher the increase in revolutions between NVO and N10.

When special use is required (for example, in vehicles with a power take-off box), the regulator can maintain the engine speed within the required area (2) between the idle turnover and increased idle speed (maximum), (1-control railway rail).

Fig. Adjustment of intermediate speed

Engine speeds (5), therefore, fluctuate only within the working area between NV. (Full load-3) and N1 (without load-4) depending on the load.

Regulation may also take place in the lowest engine speed.

Fig. Control low idle speed: 1. Proceedings of the control rail; 2. Management area; 3. Full load; 4. Without load; 5. Engine turnover.

After starting a cold engine when the control rail moves from the start position to the position of the friction, the resistance of the friction engine remains rather high, this means that the amount of fuel supplied for the stable operation of the engine will be slightly higher than that typically corresponds to the adjusting point L for low idle speed Stroke, and engine turns will be slightly lower. When warm up, the friction reduction will cause an increase in engine speed, and the control rail will move back to L. This is the installation of low idle speed for the engine located at operating temperature.

Turing torque management

Torque control is used to ensure complete use of air for combustion entered into the engine cylinder. In this case, the control process is not relevant, but more than one adjustment function is superimposed on the controller. It is designed for the amount of fuel supplied for the full load mode, i.e. For the maximum amount of fuel, injected in the engine load area and which can be burned without excessive smoke formation. In general, the need for atmospheric fuel (i.e. without boost) diesel engine decreases with an increase in engine speed (reduced relative air flow rate, temperature limit, changeable mixing formation). On the other hand, with the constant position of the control rail, the amount of fuel, injected TNVD, increases in a certain area when revolutions increase. This is due to the effect of throttling from the hole for the reset (drain hole) of the pump PNVD plunger. However, the injection of excess fuel leads to emissions of smoke and engine overheating. This means that the amount of fuel injected must be adapted to the engine needs in fuel.

Fig. a) the need for the engine in fuel; b) fuel supply in full load mode without torque control; c) fuel supply in full load mode with torque control; 1. The amount of fuel supplied; 2. The beginning of the torque management; 3. End of torque management; 4. Scope of torque control; 5. Engine turnover.

Regulators of revolutions with torque control control rake moves in the torque control area on a fixed value (the so-called torque control rate) in the stop direction (fuel cut-off). Thus, when the revolutions increase (from N1, to N2), the amount of fuel supplied decreases (forced torque control or torque control in the direction of control). When the engine turnover is falling (from N2 to N1), the feed increases.

Fig. 1. Management of racks; 2. The beginning of the torque management; 3. End of torque management; 4. Torque control process; 5. Engine turnover.

The design and arrangement of instruments for controlling torque change in accordance with the type of regulator. The torque curve C and without torque control is shown in the figure. The maximum torque is achieved throughout the range of revolutions shown without exceeding the smoke limits.

Fig. 1. MD motor torque; 2. The beginning of the torque management; 3. End of torque management; 4. With the control of torque; 5. without torque control; 6. Engine turnover.

On the engines equipped with a turbocharger with an exhaust gases having a high boost rate, the need for fuel on the full load mode in the fields of low revolutions increases so much that the standard increase in fuel supply from the pump becomes insufficient. In such cases, the torque control should be regulated depending on the rotor of the engine or pressure of the injected air.

Depending on the prevailing conditions, this is carried out using either a regulator or pressure compensator in the intake manifold (LDA) or both of these devices.

Fig. Fuel Feed Characteristics:
a) the need for the engine in fuel; b) feed in full load mode without torque control; c) feed in full load mode with torque control; C1 - negative (free) torque control; C2 - forced (positive) torque control; 1. The amount of fuel supplied; 2. Torque control; 3. Negative; 4. Positive; 5. Engine turnover.

After replacing the timing belt or high pressure fuel pump (TNVD) on a diesel engine, a problem often arises with the search for tags for which the pulley of the pump should be set. Its incorrect position leads to a late supply of fuel and improper engine operation. To avoid this, you should act in proven way.

P & G placement sponsor Article on "How to set a moment of injection on a diesel engine" How to heated for the engine with your own hands How to remove air from the Kalina cooling system How to check DMRV on VAZ 2110

Instruction

First of all, unscrew the high pressure tube from the nozzle of the first cylinder of the engine. You put on it a transparent plastic tube so that it is directed upwards, and it was clearly visible to the level of fuel filling it. The tube must hold well on the nozzle. To secure it, use the screw clamp. Fuel should not flow!

Remove the belt of the gas distribution mechanism ...

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The principle common for all diesel engines be it BMW, Audi, FV, tractor or something else.

Here I will give two original text and my explanations. Unfortunately, I wrote to the forum, so comments are not in 3 face.

Text No.z

Sequence of the angle checking (torque) of the fuel supply: Clean from dirt and dust The body of the neck for filling the oil and the meter of hours, as well as the place of attachment of the high pressure tube of the first cylinder to the fuel pump;
Install the first cylinder piston in the corresponding termination of the compression tact (for this, they include a decompression mechanism and, rotating the crankshaft, combine the labels on the cover of the distribution gear and the leading pulley of the fan drive: when using the WTN pump with the fifth from the RISA tag "T", when applied ND-21/4 pump with the second, when using the ND-21/2 pump from the first);
Remove the body of the oil refining neck along with a motorcycle and toilize the slotted flange from the fuel gear ...

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You yourself will not exhibit it! You can even do not try!
on your experience I will tell you!

better looking for intelligent masters!

and to confirm my words ... Here is the advice:

The dynamic angle is measured by a special professional stroboscope during the engine operation on XX (740 rpm). Adjustable, naturally, on the stopped and checked again on the started. If it is necessary, the adjustment is repeated until the desired result is obtained. Professional stroboscopes have few people have, so nothing surprising that your masters have no place. It is not and here - too expensive thing. Therefore, there is a method of adjusting ahead in statics, i.e. on a fixed motor. In the static, ahead of your motor should be 24 degrees to the VMT. There are two advanced advance tuning technologies in statics.
1 - drip method. A discharge valve of 1 cylinder is removed from the pump. A discharge valve fitting returns to his place and a piece of tube is dressed on it ...

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That the fuel injection advance for diesel engines is very important, it is not necessary to explain to anyone. Naturally, for each engine speed optimally, there will be some definite angle of ahead, for example, for idling 800 rpm - this is 3 °, 1000 rpm - 4 °, 1500 rpm - 5 °, etc . To achieve such a dependence, which, by the way, is not linear, there is a special mechanism in the TNVD housing. However, it is just a piston (sometimes in the literature it is called a timer), which moves inside the fuel pressure and through a special leash on this or that angle unfolds a special washer with a wave profile. There will be a piston push further - the wave of the washers slightly takes the plunger to the plunger, he will start moving and earlier will begin to serve fuel to the nozzle. In other words, the injection advance angle depends on the fuel pressure inside the TNLD housing and on the degree of wear of the wave profile of the washer. With fuel pressure, as a rule, no problems happens. Well, unless ...

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Everything is correct for the mechanical TNVD "Bosch" or his clone "Zixel Kiki", except that high pressure tubes need to weaken to the limit, and better remove. Otherwise, with force, it is necessary to rotate the pump in one direction or another, and because of this tube, then there are in one-sided voltage, and taking into account the fact that the tubes have vibration themselves by itself in the pulses of the fuel movement under pressure 127 kg / cm, then This is fraught with the emergence of microcracks on them, which not always successfully managed to brew, I tried, I know. The size of the lifting of the PTNVD Bosch plunger is usually the same on all and depends on the volume of the engine, for example for 1.6 liters. Turbo it is 0.75 ...

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How to set the moment of injection
on diesel.

It happens that after replacing the belt of the gas distribution mechanism (TRM) or fuel pump (TNVD) on the diesel engine, it is difficult to find tags for which you need to set the pulley of the pump to ensure timely fuel supply. How to be?

You can, of course, try to "catch" the desired position of the fuel pump pulley by the method of "scientific tyk", i.e. put in one position and try to start the engine.

I did not get started - check the pulley of the pump on 3-5 teeth relative to the toothed belt to any side and try again.

I got up, but badly knocks - the early injection, it means that it is necessary to turn the pulley for 1-2 tooth against the direction of rotation and start the engine again.

I got up, but smokes and works very softly - late injection, you need to check the pump pulley by 1 tooth in the direction of its rotation.

After the rearrangement of the belt can no longer achieve accurate adjustment, it is necessary to weaken the nuts of fastening of the pump and turning ...

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Check and regulating the ahead of the fuel feed or injection on the engine

Connecting labels on the drive parts are delivered for a new pump and engine. In the process of operation, plunger pairs and gears wear out and the injection advance angle varies. Consequently, after the tag connections, the pump must necessarily check the actual angle, injection advance and, if necessary, adjust it using the adjustment device in the drive mechanism. The nominal values \u200b\u200bof the injection advance angles are shown in Table 9. The advance angles directly measure it difficult. Therefore, for each engine, auxiliary values \u200b\u200bare given (for example, the length of the arc of the circular pulley of the fan), available for measurement.

By analogy with the pump adjustment on the stand, the fuel injection advance angle on the diesel engine is determined by the time the feed start and at the time of the beginning of the fuel injection.

In most diesel engines when checking the angle of the cooler; ethnya at the time of the start of the feed ...

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Check and adjust the fuel advance angle of the YMZ-238 fuel

To adjust the fuel injection advance angle on the flywheel crankcase, two hatches are provided (see Fig. 1), and the angles are applied on the flywheel in two places. For the lower pointer 3, these values \u200b\u200bare made on the flywheel in digital terms, and for the side pointer 4 - in letter expression, with the letter "A" corresponds to a value in digital expression 20 °; the letter "b" -15 °; the letter "in" -10 °; The letter "G" - 5 °.

Rotate the engine crankshaft clockwise (if you look from the fan side) to the combination of labels on the crankshaft pulley and the lid of the distribution gear or on the flywheel with the pointer corresponding to the installation angle of fuel injection -...

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Installing the fuel injection advance angle. All you need to know a non-small number of modern cars can ride on a diesel engine and therefore many motorists want to know about such a procedure as - setting the fuel injection advance angle. The definition and its correct installation has the cornerstone for high-quality diesel engine. It is worth noting the fact that a certain frequency of rotation has its own, universal.

There are already established indicators, for example, for 800 revolutions per minute, and this is idle, the advance angle will be 3 degrees, for 1000 revolutions it increases to 4 degrees, at 1500 it becomes 5 degrees.

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10

1 Engine ignition system - the difference between "diesel" from a gasoline engine

Due to the indicated differences in the process of igniting gasoline and diesel fuel in the engine, you can note the difference and in the ignition structure. Obviously, at least that such a system, as in a gasoline car, consisting of a distributor of a distributor, switch, or impulse sensors, no sensors in the diesel engine. However, in winter, it is sometimes difficult to start a diesel engine, due to the fact that the air is too cold, therefore establish a special preheating system to increase the air temperature in the combustion chamber.

It can be said that the installation of the ignition on the diesel engine is nothing but the choice of the fuel injection ahead. And this is achieved by adjusting the position of the piston, at the time of injection of "diesel" in the cylinder. It is very important, since with the wrong choice of angle injection will be untimely, and, as a result, the fuel will not burn until the end ....

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11

Glow plugs

Any carcar diesel, for a steady start, is equipped with heat candles. The main task is to warm up air and the fork meter before starting the engine. After the diesel started, the candles in the operation of the diesel engine are not involved. In some European and Japanese candle dieselms, the candles still work constantly or intermittently before the engine warming up and on hot but it is not necessary for sustainable work, but to reduce harmful emissions. If your forkar diesel does not start, then in 90 cases of 100, candles or heat relays are to blame. The easiest way to check the candles is disconnected from the output of the candle of the wires from the relay and touch this output by the wire from the plus of the battery. The main rule - it is necessary to concern briefly as the battery voltage of 12 - 13 volts, and the voltage supplied to the candle sometimes does not exceed six volts. In the presence of...

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