RU2535799C1 - Method of diagnostics of plunger pair of diesel high-pressure fuel pump - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: invention relates to propulsion engineering, in particular, may be used to diagnose plunger pairs of high pressure fuel pumps (HPFP) of diesel engines. A method is proposed to diagnose a plunger pair of a diesel engine HPFP, consisting in cyclic supply of fuel from the above-plunger space of the HPFP plunger pair under pressure into the open reservoir of the device for diagnostics of the plunger pair until its total filling. They measure density of fuel, viscosity of fuel and actual volume of fuel with total filling of the reservoir, measurement of pressure of supplied fuel is carried out in real time mode. Using the produced measurements they produce dependence of pressure of supplied fuel on time of complete filling of the open reservoir, using which they determine rated volume of fuel with complete filling of the open reservoir, after which they determine difference V_ut of rated volume of fuel and actual volume of fuel that arrived into the open reservoir, by the value of which they decide on the value of wear of the plunger pair.

EFFECT: technical result consists in increased efficiency of determination of wear extent of an HPFP plunger pair.

1 dwg, 1 tbl

Description

The claimed invention relates to the field of testing of fuel equipment of diesel engines and can be used for bench-free diagnosis of the technical condition of the plunger pair of the high-pressure fuel pump of diesel engines.

It is well known that a high-pressure fuel pump is a plunger-bushing plunger pair located inside the pump casing. The pump housing is made with a fitting, one end of which is connected to the high pressure pipe, and the other is in contact with the valve for passing fuel from the above-plunger space into the high pressure pipe [G. Fedotov, G.I. Levin. Fuel systems of diesel diesel engines. - M .: Transport, 1983, p. 4-22]. The main unit of the diesel fuel system is a high-pressure fuel pump, the plunger pair of which pumps fuel into the nozzle in a strictly metered amount.

When fuel is supplied to the diesel nozzle, part of the fuel seeps through the gap between the plunger and the sleeve of the plunger pair, which increases during operation and may exceed the permissible level. About 80% of the plunger pairs are rejected due to an increase in the gap between the plunger and the bushing of the plunger pair above the permissible level.

Known bench and in-place methods for diagnosing a plunger pair of a diesel high pressure fuel pump, based on determining the wear of the plunger pair by various diagnostic parameters.

A known method for diagnosing a plunger pair of a diesel high pressure fuel pump is based on determining the wear of a plunger pair by a diagnostic parameter - the maximum pressure of the supplied fuel [RF patent 2303159, IPC F02M65 / 00. A device for diagnosing precision pairs of a fuel pump and diesel injectors / V.I. Chernoivanov, A.V. Kolchin, B.Sh. Kargiev, A.A. Dankov, G.G. Emelyanov D.V. Doronin (RF); State Scientific Institution All-Russian Scientific Research Technological Institute for Repair and Maintenance of the Machine and Tractor Park (GNU GOSNITI) (RF). - No. 2005136981/06; claimed 11/29/2005; published on July 20, 2007, bull. No. 20].

A known method for diagnosing a plunger pair of a diesel high-pressure fuel pump is to pre-prepare the high pressure fuel pump for measurements, to supply fuel from the diesel fuel supply system to the supra-plunger space of the plunger pair under pressure until a constant value is reached, to measure this pressure, the value of which the amount of wear of the plunger pair.

A device for diagnosing a plunger pair of a high pressure fuel pump used in the known method comprises a housing with a closed container and a pump located inside it, a fuel supply pressure sensor mounted on the housing of the diagnostic device, which is connected with the closed tank.

A method for diagnosing a plunger pair of a diesel high-pressure fuel pump is carried out directly on the diesel engine, while changing the direction of fuel supply to the plunger pair above the plunger space compared to the direction of fuel supply on a running diesel engine. Thus, for the diagnosis of the condition of the plunger pair requires the creation of special conditions other than operational.

A method for diagnosing a plunger pair of a diesel high pressure fuel pump starts with partial disassembly of the high pressure fuel pump by removing a valve from the fuel pump to pass fuel from the plunger space above the plunger pair and the high pressure pipe and installing a device for diagnosing the plunger pair of the fuel pump on the nozzle instead of the high pressure pipe high pressure, which is connected to the diesel fuel supply system.

Further, fuel is supplied to the supra-plunger space of the plunger pair under pressure from the fuel supply system of the diesel engine by the pump of the device for diagnosing the plunger pair through the nozzle of the high-pressure fuel pump. In the process of its supply, the fuel completely fills the closed capacity of the device for diagnosing the plunger pair and the closed above-plunger space of the plunger pair of the high pressure fuel pump. Further fuel entry into these cavities leads to an increase in the fuel pressure in them, as determined by the pressure sensor of the supplied fuel. Fuel is supplied to the supra-plunger space of the plunger pair until the fuel pressure in it reaches a constant maximum value, the pressure stops growing and remains unchanged. When a constant fuel pressure is reached in the supra-plunger space of the plunger pair, the fuel supply to it is stopped. Stop supplying fuel to the supra-plunger space of the plunger pair and when the fuel pressure in the supra-plunger space of the plunger pair reaches 350 kgf / cm ² .

When fuel is supplied, part of the supplied fuel from the above-plunger space of the plunger pair seeps through the gap between its plunger and the sleeve. The amount of fuel leakage depends on the gap between the plunger and the sleeve of the plunger pair.

In the known method, the diagnostic parameter determining the wear of the plunger pair is the value of the maximum pressure of the supplied fuel into the plunger pair above the plunger. At the maximum pressure of the fuel supplied to the supraplunger space of the plunger pair, equal to 350 kgf / cm ² , a conclusion is made about the excellent condition of the plunger pair, at 300 kgf / cm ² - a conclusion is made about the working condition of the plunger pair.

The advantage of the known method for diagnosing a plunger pair of a diesel high pressure fuel pump is the ease of diagnosing the condition of the plunger pair.

A disadvantage of the known method for diagnosing a plunger pair of a diesel high pressure fuel pump is the low resolution of determining the degree of wear of the plunger pair. This is due to the fact that the gradation of determining the degree of wear of the plunger pair is limited by two states - the excellent condition of the plunger pair and the working condition. With this gradation, workable plunger pairs can be classified as inoperative.

The second disadvantage of this method is the partial disassembly of the high pressure fuel pump, which leads to increased wear of the plunger pair due to the ingress of abrasive particles into the plunger pair above the plunger space and into the gap between the plunger and the plunger pair sleeve during disassembly.

The closest in technical essence to the claimed solution is a method for diagnosing a plunger pair of a diesel high pressure fuel pump, based on determining the wear of the plunger pair by a diagnostic parameter - the value of the fuel pressure rise rate in a closed tank of a device for diagnosing a plunger pair of a high pressure fuel pump [RF patent 2456471 , IPC F02M 65/00, G01M 15/04. Method and device for bench-free diagnosis of high-pressure diesel fuel equipment / V.A. Chechet, A.M. Aliev (RF); Federal State Educational Establishment of Higher Professional Education "Moscow State Agroengineering University named after V.P. Goryachkina ”(RF). - No. 2011105759/06; claimed 02.17.2011; published on July 20, 2012, bull. No. 20].

A known method for diagnosing a plunger pair of a diesel engine high pressure fuel pump consists in cyclic supply of fuel under pressure from a diesel fuel supply system to the plunger pair above the plunger space with its subsequent supply to a closed container of a device for diagnosing a plunger pair of a high pressure fuel pump, in measuring the temperature of the supplied fuel, determining the actual volume of fuel supplied in one cycle, in determining the temperature coefficient, in determining the diagnostic parameter, the value of which is judged on the amount of wear of the plunger pair.

A method for diagnosing a plunger pair of a diesel high pressure fuel pump is carried out without disassembly. In the known method, the diagnostic parameter determining the wear of the plunger pair is the value of the rate of increase of the fuel pressure in the closed tank of the device for diagnosing the plunger pair of the high pressure fuel pump.

Used in the known method, a device for diagnosing a plunger pair of a high pressure fuel pump contains a housing with a closed tank, a pressure sensor of the supplied fuel mounted on the housing, which are associated with a closed tank.

A method for diagnosing a plunger pair of a diesel high-pressure fuel pump is carried out directly on the diesel engine, while changing the direction of the fuel supply: it enters the closed capacity of the diagnostic device, while on a running diesel engine it enters the diesel nozzle. Thus, for the diagnosis of the condition of the plunger pair requires the creation of special conditions other than operational.

Before diagnosing the plunger pair of the high pressure fuel pump, the high pressure pipe is removed from the nozzle of the high pressure fuel pump and a device for diagnosing the plunger pair of the high pressure fuel pump is installed on it.

Fuel from the diesel fuel supply system is supplied under pressure to the plunger pair above the plunger. When the plunger is lifted once, the supplied fuel is displaced from the plunger pair above the plunger into the closed capacity of the diagnostic device, filling it. This process is repeated for a given number of cycles n _c diesel operation, for example 5-12 cycles.

In the process of supplying fuel, part of the supplied fuel from the above-plunger space of the plunger pair seeps through the gap between its plunger and sleeve. The amount of fuel leakage depends on the gap between the plunger and the sleeve of the plunger pair.

When filling the closed capacity of the device for diagnostics with fuel, a pressure is created in it, which is determined using the pressure sensor of the supplied fuel. With each subsequent cycle, the pressure in the closed tank increases, while the fuel leakage from the plunger pair above the plunger space also increases.

In the process of filling the closed capacity of the device for diagnosing the plunger pair of the high pressure fuel pump plunger with fuel, measure the temperature of the supplied fuel t, the value of which determines the temperature coefficient v _{° C} , according to the formula:

, $$v_{°C}=\frac{\mathrm{one}}{(\mathrm{one}-\mathrm{1,5}\cdot {10}^{{}_{-3}}\cdot \Delta t)}$$

,

where Δt = tt ₀ ,

t is the temperature of the supplied fuel, ° C,

t ₀ = 20 ° C.

(действительный объем топлива, подаваемого за один цикл), по величине которой определяют поправочный коэффициент активного хода плунжера v_h по формуле:Next, measure the cyclic fuel supply $$q_{a.x}^f$$

(actual volume of fuel supplied in one cycle), the value of which determines the correction factor of the active stroke of the plunger v _h according to the formula:

, $$v_h=\frac{q_{a.x}^n}{q_{a.x}^f}$$

,

- цикловая подача топлива эталонного топливного насоса высокого давления, г/цикл,Where $$q_{a.x}^n$$

- cyclic fuel supply reference fuel pump high pressure, g / cycle,

- цикловая подача топлива проверяемого топливного насоса высокого давления, г/цикл. $$q_{a.x}^f$$

- cyclic fuel supply of the tested high pressure fuel pump, g / cycle.

Then determine the diagnostic parameter - the rate of increase of fuel pressure in a closed tank of the device for diagnosing a plunger pair of a high pressure fuel pump according to the formula:

, $$\overline{p_{\max }}=\frac{p_{\max }}{n_c}\cdot v_h^a\cdot v_{°C}$$

,

where p _max is the maximum pressure of the supplied fuel in the above-plunger space of the plunger pair, Pa,

n _c - the number of cycles of the diesel engine (for example, 5-12 cycles),

v _h - correction factor of the active stroke of the plunger,

a is a power coefficient characterizing the degree of wear and microgeometry of the friction surfaces between the plunger and the sleeve of the plunger pair,

v _{° C} - temperature coefficient.

=180-200 кгс/см²/цикл (18-20 МПа/цикл) делают вывод об отличном состоянии плунжерной пары, при значении скорости нарастания давления в интервале $$\overline{p_{\max }}$$

=120-130 кгс/см²/цикл (12-13 МПа/цикл) делают вывод о предельно изношенном состоянии плунжерной пары.The magnitude of the diagnostic parameter is judged on the degree of wear of the plunger pair. With the value of the pressure rise rate in the range $$\overline{p_{\max }}$$

= 180-200 kgf / cm ² / cycle (18-20 MPa / cycle) conclude that the plunger pair is in excellent condition, with a pressure rise rate in the range $$\overline{p_{\max }}$$

= 120-130 kgf / cm ² / cycle (12-13 MPa / cycle) make a conclusion about the extremely worn condition of the plunger pair.

A known method for diagnosing a plunger pair of a diesel high pressure fuel pump allows diagnosing the condition of the plunger pair without disassembly, which is the advantage of the method.

A disadvantage of the known method for diagnosing a plunger pair of a diesel high pressure fuel pump is the low resolution of determining the degree of wear of the plunger pair. This is due to the fact that the gradation of determining the degree of wear of the plunger pair is limited to extreme conditions - a new plunger pair and extremely worn plunger pair. Therefore, plunger couples with an intermediate wear value will be assigned to one of the extreme states of the degree of wear of the plunger pair, which leads to the rejection of workable plunger couples.

The problem solved by the invention is to develop a method for diagnosing a plunger pair of a diesel high-pressure fuel pump, which allows to increase the resolution of determining the degree of wear of the plunger pair by expanding the gradation of the degree of wear between the extreme conditions — a new plunger pair and extremely worn plunger pair while significantly improving accuracy diagnostics due to testing of the plunger pair directly under conditions corresponding to the conditions of its operation in Operating IU.

To solve the problem in a method for diagnosing a plunger pair of a diesel high pressure fuel pump, which consists in cyclic supply of fuel from the above-plunger space of a plunger pair of a high pressure fuel pump, in measuring pressure and the actual volume of fuel, in determining a diagnostic parameter that takes into account the recorded value of the fuel pressure , in it, as a diagnostic parameter that takes into account the recorded pressure, choose the difference in the calculated volume then the amount of fuel and the actual volume of fuel entering the open tank when it is full, the fuel is cycled from the supraplunger space of the plunger pair of the fuel pump under pressure to the open tank of the device for diagnosing the plunger pair until it is full, the density and viscosity of the fuel are measured, the actual volume is determined fuel when the open tank is fully filled, the pressure of the supplied fuel is measured in real time, according to the measurements obtained, the dependence of the pressure of the supplied fuel on the time of full filling of the open tank, which determines the estimated volume of fuel when the tank is completely filled according to the area of the flat figure, limited by the pressure dependence and coordinate axes, after which the difference V _{ut of the} estimated volume of fuel and the actual amount of fuel received open tank, the value of which is judged on the amount of wear of the plunger pair:

with a kinematic viscosity equal to v ₁ = 4-5 cSt and a difference between the calculated and actual volumes of fuel per unit volume within V _ut = 0.109-0.11 ml, a conclusion is made about the excellent condition of the plunger pair, within V _ut = 0.128- 0.131 ml - about the working condition of the plunger pair, within V _ut = 0.142-0.146 ml - about the satisfactory condition of the plunger pair, within V _ut = 0.171-0.18 ml - about the extremely worn condition of the plunger pair,

with a kinematic viscosity equal to v ₂ = 5-6 cSt and a difference between the calculated and actual volumes of fuel per 1 ml of fuel within V _ut = 0.108-0.109 ml, a conclusion is made about the excellent condition of the plunger pair, within V _ut = 0.124-0.128 ml - about the working condition of the plunger pair, within V _ut = 0.137-0.142 ml - about the satisfactory condition of the plunger pair, within V _ut = 0.163-0.171 ml - about the extremely worn condition of the plunger pair,

when the kinematic viscosity equal to v ₃ = 6-7 cSt and the difference between the calculated and actual volumes of fuel per 1 ml of fuel within V _ut = 0.107-0.108 ml, a conclusion is made about the excellent condition of the plunger pair, within V _ut = 0.12 -0.124 ml - about the working condition of the plunger pair, within V _ut = 0.132-0.137 ml - about the satisfactory condition of the plunger pair, within V _ut = 0.154-0.163 ml - about the extremely worn condition of the plunger pair,

at a kinematic viscosity equal to v ₄ = 7-8 cSt, and the difference between the calculated and actual volumes of fuel per 1 ml of fuel within V _ut = 0.106-0.107 ml, a conclusion is made about the excellent condition of the plunger pair, within V _ut = 0.115-0 , 12 ml - about the working condition of the plunger pair, within V _ut = 0.126-0.131 ml - about the satisfactory condition of the plunger pair, within V _ut = 0.145-0.154 ml - about the extremely worn condition of the plunger pair,

at a kinematic viscosity equal to v ₅ = 8-9 cSt, and the difference between the calculated and actual volumes of fuel per 1 ml of fuel within V _ut = 0.106-0.107 ml, a conclusion is made about the excellent condition of the plunger pair, within V _ut = 0.109-0.115 ml - about the working condition of the plunger pair, within V _ut = 0.12-0.126 ml - about the satisfactory condition of the plunger pair, within V _ut = 0.135-0.145 ml - about the extremely worn condition of the plunger pair.

The inventive method for diagnosing a plunger pair of a diesel high pressure fuel pump differs from the prototype in the introduction of new operations and a new sequence of their implementation in the method, the choice of a new diagnostic evaluation parameter, a new definition of its value. The presence of new significant distinguishing features indicates the compliance of the proposed solutions to the patentability criterion of the invention of "novelty."

The presence of new significant distinguishing features in the method for diagnosing a plunger pair of a diesel high-pressure fuel pump leads, together with the remaining essential features of the method, to increase the resolution of determining the degree of wear of the plunger pair by expanding the gradation of the degree of wear between the extreme conditions — a new plunger pair and extremely worn plunger pair , and a significant increase in the accuracy of diagnostics by testing the plunger pair directly on the diesel engine in conditions that correspond to the conditions of its operation in operation mode.

This is due to the fact that the amount of leaks of the supplied fuel leaked from the plunger pair above the plunger space into the gap between the plunger and the plunger pair bushing is determined over a longer period of time when the plunger pair plunger pair is repeatedly filled with the supplied fuel, which makes it possible to more accurately estimate the amount of leaked fuel, by which they more accurately judge the performance of the plunger pair. Improving the accuracy of determining the state of the plunger pair in turn will expand the range of gradation of the degree of wear between the extreme states of the plunger pair.

Causal relationship “The choice as a diagnostic parameter of the difference between the calculated and actual volumes of fuel entering the open tank, the supply of fuel under pressure to the open tank until it is full, measuring the density and viscosity of the fuel, determining the actual volume of fuel when the open tank is full, measuring the pressure of the supplied fuel in real time, obtaining the dependence of the pressure of the supplied fuel on the time of full filling of the open tank, determining the estimated fuel volume by the area of a flat figure, limited by the pressure dependence and coordinate axes, by determining the difference between the calculated and actual volumes of fuel received in an open tank, the value of which is used to judge the amount of plunger pair wear, which increases the resolution to determine the degree of plunger pair wear due to expanding the gradation of the degree of wear between extreme states - a new plunger pair and extremely worn plunger pair, while at the same time a significant increase diagnostic accuracy due to testing the plunger pair under conditions corresponding to the conditions of its operation in the operating mode "is not found in the prior art and does not explicitly follow from it. It is new, which indicates the conformity of the proposed solution to the patentability criterion of "inventive step".

The drawing shows a diagram of a device for diagnosing a plunger pair of a high pressure fuel pump installed on a high pressure fuel pump, which allows to explain the operability of the inventive method for diagnosing a plunger pair of a diesel high pressure fuel pump and confirming its industrial applicability.

The inventive method for diagnosing a plunger pair of a diesel high pressure fuel pump is implemented directly on a diesel high pressure fuel pump, which is a pump housing 1 with a nozzle 2 of a high pressure fuel pump, a plunger pair 3 and a valve 4. Plunger pair 3 located inside the pump housing 1 represents a plunger 5 and a sleeve 6, between which a plunger space is formed 7. At the end of the sleeve 6, a valve 4 is installed for passing fuel from the plunger space 7 into the high pressure pipe 8.

For diagnostics, a device for diagnosing a plunger pair of a high pressure fuel pump is used, which contains an open container 9, an open type nozzle 10 connected to it by a high pressure pipe 8, and a pressure sensor 11 of the supplied fuel mounted on the high pressure pipe 8.

A method for diagnosing a plunger pair of a diesel engine high pressure fuel pump consists in cyclic supply of fuel under pressure from the diesel fuel supply system to the supraplunger space 7 of the plunger pair 6 with its subsequent supply to the open tank 9 until it is full, in measuring the pressure of the supplied fuel in real time, in measuring the density and viscosity, in obtaining the dependence of the supplied fuel on time to the full filling of the open tank 9, in measuring the actual volume of fuel at full filling the open tank 9, in determining the estimated volume of fuel when the open tank 9 is completely filled by the area of the flat figure, limited by the pressure dependence and coordinate axes, in determining the difference between the calculated and actual volumes of fuel entering the open tank 9, in determining the diagnostic parameter - the calculated and the actual amount of fuel, the value of which is judged on the amount of wear of the plunger pair.

A method for diagnosing a plunger pair of a diesel high pressure fuel pump is carried out without disassembling directly on the diesel engine under conditions that do not differ from operational conditions - the fuel supply process is carried out in the same way as on a running diesel engine.

In the inventive method, the diagnostic parameter that determines the wear of the plunger pair 3 is the difference between the calculated and actual volumes of fuel received in an open tank when it is full.

An example implementation of a method for diagnosing a plunger pair of a diesel high pressure fuel pump

Before diagnostics, from the nozzle 2 of the high-pressure fuel pump, a standard high-pressure pipe is removed and a device for diagnosing a plunger pair of the high-pressure fuel pump is installed on it.

Fuel from the diesel fuel supply system is supplied under pressure to the supraplunger space 7 of the plunger pair 3 of the high pressure fuel pump. With a single rise of the plunger 5, the supplied fuel from the above-plunger space 7 of the plunger pair 3 is forced into the open tank 9 of the device for diagnosing the plunger pair of the high pressure fuel pump, gradually filling it. This process is repeated until the open tank 9 is completely filled.

During the fuel supply, part of the supplied fuel from the above-plunger space 7 of the plunger pair 3 seeps through the gap between its plunger 5 and the sleeve 6. The amount of fuel leakage is determined by the size of the gap between the plunger 5 and the sleeve 6 of the plunger pair 3 of the high pressure fuel pump.

The pressure of the supplied fuel is measured in real time by the pressure sensor 11 of the supplied fuel in the process of filling the open tank 9 with fuel. According to the obtained data, the dependence of the supplied fuel pressure on time is obtained.

When the open tank 9 of the device for diagnosing the plunger pair of the high pressure fuel pump plunger is completely filled, the viscosity of the supplied fuel is measured with a viscometer, its density is measured with a beaker, the actual fuel volume V _d .

Next, determine the estimated volume of fuel supplied to the open tank 9. The estimated volume of fuel is determined by the area of a flat figure, limited by the dependence of pressure on time and coordinate axes, according to the well-known formula [A.I. Volodin. Computer simulation of diesel locomotive operation. - M .: Transport, 1985, S.156]:

$$V_m={\displaystyle \underset{r\mathrm{one}}{\overset{r2}{\int }}\mu F}\sqrt{\frac{2}{\rho }(p_{\mathrm{one}}-p_2)d\tau },$$

where F is the area of the nozzle holes of the spray, m ² ,

µ - expense coefficient,

ρ is the density of the supplied fuel, kg / m ³ ,

p ₁ is the fuel pressure in the high pressure pipe, Pa,

p ₂ is the fuel pressure in an open tank, Pa.

Next, determine the diagnostic parameter - the difference between the calculated and actual fuel volume V _ut = V _m -V _d .

The magnitude of the diagnostic parameter V _ut judge the degree of wear of the plunger pair.

with a kinematic viscosity equal to v ₁ = 4-5 cSt and a difference between the calculated and actual volumes of fuel per unit volume within V _ut = 0.109-0.11 ml, a conclusion is made about the excellent condition of the plunger pair, within V _ut = 0.128- 0.131 ml - about the working condition of the plunger pair, within V _ut = 0.142-0.146 ml - about the satisfactory condition of the plunger pair, within V _ut = 0.171-0.18 ml - about the extremely worn condition of the plunger pair,

with a kinematic viscosity equal to v ₂ = 5-6 cSt and a difference between the calculated and actual volumes of fuel per 1 ml of fuel within V _ut = 0.108-0.109 ml, a conclusion is made about the excellent condition of the plunger pair, within V _ut = 0.124-0.128 ml - about the working condition of the plunger pair, within V _ut = 0.137-0.142 ml - about the satisfactory condition of the plunger pair, within V _ut = 0.163-0.171 ml - about the extremely worn condition of the plunger pair,

when the kinematic viscosity equal to v ₃ = 6-7 cSt, and the difference between the calculated and actual volumes of fuel per 1 ml of fuel within v _ut = 0.107-0.108 ml conclude that the plunger pair is in excellent condition, within v _ut = 0.12 -0.124 ml - about the working condition of the plunger pair, within v _ut = 0.132-0.137 ml - about the satisfactory condition of the plunger pair, within v _ut = 0.154-0.163 ml - about the extremely worn condition of the plunger pair,

at a kinematic viscosity equal to v ₄ = 7-8 cSt, and the difference between the calculated and actual volumes of fuel per 1 ml of fuel within V _ut = 0.106-0.107 ml, a conclusion is made about the excellent condition of the plunger pair, within V _ut = 0.115-0 , 12 ml - about the working condition of the plunger pair, within V _ut = 0.126-0.131 ml - about the satisfactory condition of the plunger pair, within V _ut = 0.145-0.154 ml - about the extremely worn condition of the plunger pair,

at a kinematic viscosity equal to v ₅ = 8-9 cSt, and the difference between the calculated and actual volumes of fuel per 1 ml of fuel within V _ut = 0.106-0.107 ml, a conclusion is made about the excellent condition of the plunger pair, within V _ut = 0.109-0.115 ml - about the working condition of the plunger pair, within V _ut = 0.12-0.126 ml - about the satisfactory condition of the plunger pair, within V _ut = 0.135-0.145 ml - about the extremely worn condition of the plunger pair.

With this gradation of the degree of wear, the plunger pairs assigned to the group with satisfactory conditions are operational. When determining the degree of wear of the plunger pair in other ways, these plunger pairs will be assigned to the group with extremely worn condition.

In the laboratory "Thermal engines" of the department "Diesel locomotives and heat engines" DVGUPS tested the inventive method for diagnosing a plunger pair of a fuel pump of a high pressure diesel engine. In the device for diagnosing a plunger pair of a high-pressure fuel pump, a MIDA-DI-13P-1 pressure sensor, a VPZh-2 brand capillary glass viscometer, an ANT-1 brand hydrometer were used as an open type injector, a modified D49 diesel nozzle was used.

In the tests, 8 plunger pairs of D49 high-pressure fuel pumps were used.

The results of the experimental data obtained by testing 8 plunger pairs of D49 high-pressure fuel pumps are shown in the table.

The experimental data obtained when testing 8 plunger pairs of D49 high-pressure fuel pump fuel pumps show that an increase in the diagnostic resolution of the plunger pair diagnosis of a diesel high-pressure fuel pump allows 25% of plunger pairs to be considered excellent, 25% of plunger pairs working, 25% of plunger pairs satisfactory and 25% of the plunger pairs extremely worn, instead of 50% of the plunger pairs excellent and 50% of the plunger pairs extremely worn, as in the prototype. The inventive method for diagnosing a plunger pair of a diesel high-pressure fuel pump is more effective 1.5 times more efficient plunger pairs are detected.

Experimental data No. of punzher pair Kinematic viscosity, cSt The inventive method Prototype Diagnostic parameter V _ut , ml Output

, кгс/см²/цикл (МПа/цикл)Diagnostic parameter $$\overline{p_{\max }}$$

kgf / cm ² / cycle (MPa / cycle) Output one 2 5 6 3 3 one 4.6 0.109 excellent pp 182 (18.2) excellent pp 2 4.2 0.11 excellent pp 180 (18.0) excellent pp 3 4.1 0.130 working software 182 (18.2) excellent pp four 4,5 0.129 working software 181 (18.1) excellent pp 5 4.6 0.145 satisfactory PP 120 (12.0) extremely worn PP 6 4.8 0.143 satisfactory PP 121 (12.1) extremely worn PP 7 4.3 0.179 extremely worn PP 120 (12.0) extremely worn PP 8 4.3 0.174 extremely worn PP 120 (12.0) extremely worn PP one 5.2 0.109 excellent pp 184 (18.4) excellent pp 2 5,4 0.108 excellent pp 187 (18.7) excellent pp 3 5.8 0.128 working software 185 (18.5) excellent pp four 5.3 0.125 working software 186 (18.6) excellent pp 5 5.2 0.140 satisfactory PP 123 (12.3) extremely worn PP 6 5.3 0.138 satisfactory PP 122 (12.2) extremely worn PP 7 5.1 0.163 extremely worn PP 122 (12.2) extremely worn PP 8 5.5 0.172 extremely worn PP 123 (12.3) extremely worn PP

Table continuation one 2 3 four 5 6 one 6.3 0.108 excellent pp 189 (18.9) excellent pp 2 6.1 0.107 excellent pp 188 (18.8) excellent pp 3 6.6 0,120 working software 188 (18.8) excellent pp four 6.4 0.123 working software 190 (19.0) excellent pp 5 6.7 0.136 satisfactory PP 124 (12.4) extremely worn PP 6 6.3 0,132 satisfactory PP 125 (12.5) extremely worn PP 7 6.5 0.155 extremely worn PP 125 (12.5) extremely worn PP 8 6.5 0.159 extremely worn PP 124 (12.4) extremely worn PP one 7.4 0.107 excellent pp 195 (19.5) excellent pp 2 7.4 0.108 excellent pp 193 (19.3) excellent pp 3 7.6 0.116 working software 192 (19.2) excellent pp four 7.8 0.118 working software 193 (19.3) excellent pp 5 7.7 0.130 satisfactory PP 126 (12.6) extremely worn PP 6 7.2 0.129 satisfactory PP 127 (12.7) extremely worn PP 7 7.5 0.146 extremely worn PP 126 (12.6) extremely worn PP 8 7.4 0.151 extremely worn PP 126 (12.6) extremely worn PP one 8.3 0.106 excellent pp 196 (19.6) excellent pp 2 8.2 0.107 excellent pp 197 (19.7) excellent pp 3 8.3 0,110 working software 200 (20.0) excellent pp four 8.4 0.114 working software 199 (19.9) excellent pp 5 8.1 0.124 satisfactory PP 129 (12.9) extremely worn PP 6 8.6 0,126 satisfactory PP 130 (13.0) extremely worn PP 7 8.3 0.144 extremely worn PP 129 (12.9) extremely worn PP 8 8.1 0.138 extremely worn PP 128 (12.8) extremely worn PP

Claims (1)

A method for diagnosing a plunger pair of a diesel high pressure fuel pump, which consists in cyclic supply of fuel from the above-plunger space of a plunger pair of a high pressure fuel pump, under pressure, in measuring the pressure and actual volume of fuel, in determining a diagnostic parameter that takes into account the recorded value of the fuel pressure, characterized in that as a diagnostic parameter that takes into account the recorded pressure, choose the difference between the estimated fuel volume and the actual of the total volume of fuel entering the open container when it is completely filled, the cyclic supply of fuel from the above-plunger space of the plunger pair of the fuel pump under pressure is carried out in the open tank of the device for diagnosing the plunger pair until it is full, the density of the fuel, the viscosity of the fuel and the actual volume of fuel at full filling of the open tank, the pressure measurement of the supplied fuel is carried out in real time, according to the measurements obtained, the pressure dependence given by the fuel on the time of complete filling of the open container, using which the estimated amount of fuel when full open capacity for the area of a plane figure bounded by the pressure dependence and coordinate axes, and then determine the difference V _ut rated fuel volume and the actual volume of fuel released to the open container , the value of which is judged on the amount of wear of the plunger pair:
with a kinematic viscosity equal to v ₁ = 4-5 cSt and a difference between the calculated and actual volumes of fuel per unit volume within V _ut = 0.109-0.11 ml, a conclusion is made about the excellent condition of the plunger pair, within V _ut = 0.128- 0.131 ml - about the working condition of the plunger pair, within V _ut = 0.142-0.146 ml - about the satisfactory condition of the plunger pair, within V _ut = 0.171-0.18 ml - about the extremely worn condition of the plunger pair,
with a kinematic viscosity equal to v ₂ = 5-6 cSt and a difference between the calculated and actual volumes of fuel per 1 ml of fuel within V _ut = 0.108-0.109 ml, a conclusion is made about the excellent condition of the plunger pair, within V _ut = 0.124-0.128 ml - about the working condition of the plunger pair, within V _ut = 0.137-0.142 ml - about the satisfactory condition of the plunger pair, within V _ut = 0.163-0.171 ml - about the extremely worn condition of the plunger pair,
when the kinematic viscosity equal to v ₃ = 6-7 cSt and the difference between the calculated and actual volumes of fuel per 1 ml of fuel within V _ut = 0.107-0.108 ml, a conclusion is made about the excellent condition of the plunger pair, within V _ut = 0.12 -0.124 ml - about the working condition of the plunger pair, within V _ut = 0.132-0.137 ml - about the satisfactory condition of the plunger pair, within V _ut = 0.154-0.163 ml - about the extremely worn condition of the plunger pair,
at a kinematic viscosity equal to v ₄ = 7-8 cSt, and the difference between the calculated and actual volumes of fuel per 1 ml of fuel within V _ut = 0.106-0.107 ml, a conclusion is made about the excellent condition of the plunger pair, within V _ut = 0.115-0 , 12 ml - about the working condition of the plunger pair, within V _ut = 0.126-0.131 ml - about the satisfactory condition of the plunger pair, within V _ut = 0.145-0.154 ml - about the extremely worn condition of the plunger pair,
at a kinematic viscosity equal to v ₅ = 8-9 cSt, and the difference between the calculated and actual volumes of fuel per 1 ml of fuel within V _ut = 0.106-0.107 ml, a conclusion is made about the excellent condition of the plunger pair, within V _ut = 0.109-0.115 ml - about the working condition of the plunger pair, within V _ut = 0.12-0.126 ml - about the satisfactory condition of the plunger pair, within V _ut = 0.135-0.145 ml - about the extremely worn condition of the plunger pair.