RU2672992C1 - Method for testing devices of high-pressure of diesel fuel system on working engine and device for implementation thereof - Google Patents

Abstract

FIELD: computer engineering.SUBSTANCE: invention relates to the technical diagnostics of "Common Rail" diesel fuel equipment. In the proposed method of testing electro-hydraulic injectors (EHI) 17 pressure and the amount of fuel passing through common return fuel line 3 is measured, spent on the management of EHI, and the calculation of the individual consumption for the management of each EHI as the most informative indicator of their technical condition.EFFECT: measurement of pressure and flow in the common return line is performed using a pressure sensor and fuel consumption sensor, located in device 1, connected to a common return fuel line and configured to transfer data to personal computer 9.2 cl, 1 dwg

Description

Method for testing high-pressure devices of a diesel fuel system on a running engine and device for its implementation

The invention relates to engine building, in particular to the technical diagnosis of diesel fuel equipment, with a high-pressure accumulator, type "Common Rail". The method and device for its implementation are designed to detect increased fuel consumption for controlling an electro-hydraulic nozzle (EHF), in the general balance of expenses, assessing its technical condition, by measuring and analyzing pressure and fuel consumption in a common return line of a diesel engine.

There are methods for assessing the technical state of EGF without dismantling from internal combustion engines, based on the simultaneous measurement of several parameters of their operation, and instruments for implementing these methods, made in a compact portable version.

There is a method of element-by-element diagnosis of EHF, in which for a certain time the amount of fuel consumption for control from each EHF is measured when the engine is running, for example, at idle: G. Gunter Diagnostics of diesel engines. - M.: “Behind the Wheel”, 2004. -176 p. Common features with the claimed invention is the measurement of the amount of fuel spent on the management of EGF and the determination of the individual consumption of EGF, management, as the most informative indicator of their technical condition.

This method is quite effective and accurate, however, is not feasible in the case when the nozzle is located under the valve cover and the direct measurement of the fuel volume for control from each EHF is very time-consuming or impractical.

The known method (DE19703891), patent, Germany F02D41 / 38, G01M3 / 26, F02D41 / 22, G01M3 / 00, G01L23 / 26, published on 08/06/1998, determination of faulty EHF, in which the flow rate through each section of the fuel pressure accumulator is determined by monitoring rise and fall of pressure using a pressure sensor. Common features with the claimed invention is the search and determination of a faulty nozzle. This method is characterized by low sensitivity to individual injector leaks, as as a result of the operation of the injectors and sections of the high-pressure fuel pump (TNVD), pressure waves arise that can overlap each other, as well as due to the smoothing of the pulsations of the fuel pressure using dampers installed in the fuel pressure accumulator (ADT).

The known method (US 5773716) patent, US G01M15 / 00, published 06/30/98, definitions of faulty EHF, in which increased leakage is determined for EHF in the jammed state. Common features with the claimed invention is the search and determination of faulty EHF. With its help, it is possible to track only increased leaks through the atomizer, but it is not possible to detect the leakage of each EHF into the common return line.

There is also known a method (US 7317983) patent, US G06F19 / 00, F02D41 / 14 F02D45 / 00, published 8.01.2008, defective EHF, in which the value of the individual correction of fuel supply when the engine is idling acts as a diagnostic parameter. Common features with the claimed invention is the search and determination of faulty EHF. This method has low sensitivity, because even with a large leak in the nozzle, the compensation value may change slightly, especially with an increase in the number of cylinders.

There is also a diagnostic method (US 6546912) patent, US F02D41 / 04 F02M51 / 00, published April 15, 2003, defining EGF, in which EHF is judged by the crankshaft speed at certain angular positions corresponding, for example, to the working cycle interval stroke, when there is a process of expansion of each of the cylinders, without compensation of the angular feed. Common features with the claimed invention is the search and determination of faulty EHF. This method has the same disadvantages as in the previous case, because only uniformity of cyclic feeds is diagnosed, and increased leaks to the return line cannot be unambiguously identified.

The known method (US 7937988) patent, USA G01M15 / 00, published on 05/10/2011, determination of faulty EHF, it is proposed to use the change in heating of the EHF housing, and, as a result, electrical characteristics, to localize individual leaks. Common features with the claimed invention is the search and determination of a faulty nozzle. The disadvantage is that when the EGF is located under the valve cover, the temperature factors of the internal combustion engine (ICE) will also affect accuracy.

The known method (US 8459234) patent, US F02M51 / 00, published 06/11/2013 diagnostics of EHF malfunctions, including individual leaks, in which the change in pressure in the nozzle supply cavity is analyzed by installing inside each sensor, and for each EHF an individual dependence is determined pressure changes for different characteristic modes, deviation from which allows fixing almost any malfunction. Common features with the claimed invention is the search and determination of faulty EHF. This method is promising, but technically difficult and not applicable for existing fuel supply systems.

The closest technical solution adopted as a prototype is a method in which for a certain time the amount of fuel consumption for control from each EHF is measured when the engine is running, for example, at idle: G. Gunter, Diagnostics of diesel engines. - M.: “Behind the Wheel”, 2004. -176 p. The method is carried out by connecting the drain fitting of each EGF to an individual measured capacity. Thus, when the engine is idling and in other modes, the flow rate for controlling each EHF is measured and the cost balance is determined. This method is effective, informative and widely used in practice.

 Common features with the prototype is the determination of the balance of costs by measuring individual fuel consumption for EGF control.

The disadvantages of the prototype are:

- Inability to use if EHFs are located inside the engine (inside the cylinder head or under the valve cover);

- The inability to control the EGF adjustment parameters;

- Inability to monitor and record diagnostic data, including in vehicle driving mode.

The objective of the invention is aimed at improving the efficiency, informativeness and universalization of the method for the diagnosis of electro-hydraulic nozzles of battery fuel supply systems, fuel consumption for control, without dismantling from the engine.

The technical result of the invention lies in the possibility of promptly obtaining diagnostic data on the balance of expenses and individual fuel consumption for control, regardless of the structural arrangement of the EGF of a diesel engine.

The technical result of the invention is achieved by the fact that in the patented method of testing high-pressure devices of the diesel fuel system on a running engine, namely electro-hydraulic nozzles, including measuring fuel consumption for controlling each nozzle, characterized in that they connect to a common return line, which allows to determine the balance components fuel consumption in the common return line based on the measurement and analysis of data on pressure changes and the total consumption in the total return line Ali, wherein the pressure measurement and flow rate in the common return line is produced by the pressure sensor and the fuel flow sensor located in series in the common fuel return line.

A device for implementing a method for testing high-pressure devices of a diesel fuel system on a running engine, connected to a common return line of electro-hydraulic nozzles, according to the invention, contains a microcontroller, sensors for measuring fuel flow and pressure in a common return line, combined into one measuring channel configured to connect to the return line, using a connecting bolt-fitting, a control pulse sensor, for synchronization with the operation of electrohydra personal injectors, USB bus, for transferring data to a personal computer.

A device for implementing the inventive method contains sensors for measuring pressure and fuel consumption in the return line associated with the microcontroller, further comprises a sensor for measuring the phases of the engine, in the form of a current sensor based on the hall effect mounted on the control circuit of the electro-hydraulic nozzle (EHF). The pressure sensor and the fuel consumption sensor in the return line are combined into one measuring channel, configured to maintain pressure in it, using a valve controlled by pulse-width modulation, specified by the information processing device (microcontroller), to increase the information content of the pressure signal.

The invention relates to mechanical engineering, in particular to the field of technical diagnostics of high-pressure devices of diesel fuel equipment.

Power, economic and environmental indicators of diesel engines to a large extent depend on the technical condition of the high-pressure devices of the fuel system. In a battery-powered fuel supply system, the most critical and at the same time vulnerable component is the electro-hydraulic nozzle. During operation, the EHF operation parameters often go beyond the regulated values, the balance of fuel consumption for control and, accordingly, the flow rate in the common return line are violated. This necessitates periodic technical diagnostics of EGF during operation, without dismantling them from the engines. The difference from the prototype are:

- versatility, no dependence on the location of the EGF

- lack of measuring capacities;

- the ability to monitor and record data;

- design mobility;

- fewer connection points;

The presence of a new set of essential distinctive features from the prototype in the inventive device, for the diagnosis of individual leaks, the flow rate of the common return line, allows us to conclude that the claimed invention meets the criterion of "novelty."

An additional comparative analysis of patent and scientific and technical information did not reveal sources containing information about the popularity of the set of distinctive features of the proposed method for testing high-pressure devices of the diesel fuel system on a running engine, which indicates its compliance with the criterion of "inventive step".

The invention is illustrated by drawings, where in FIG. 1 schematically shows the functioning of the proposed device, as part of a battery fuel supply system of a diesel engine. The device 1 is connected using a special device 2 to the output of the common return line 3 with two rigid hoses: a supply hose 4 and a fuel return hose 5. The device 1 is connected, using special means of transmitting electrical signals 6 with a pulse sensor of the first cylinder 7 and a high pressure regulator 8 (to increase the information content of the method, if necessary). Additionally, device 1 is connected to a personal computer (PC) 9 using the USB 10 bus.

In addition, the diagram shows a fuel system circuit including a fuel tank 11 with a low pressure fuel supply line 12 included in the coarse fuel filter 13, then to the high pressure pump 14, which supplies fuel through the high pressure pipe 23 to the high pressure fuel accumulator 15 supplying fuel to the EHF 17, having an emergency valve 16, passing into the connector of the return lines 20, the electrical control circuit of the EGF 19, the connector of the drain lines 20, passing into a common drain pipe 24, returning conductive fuel to the fuel tank 11, as well as an electronic engine control unit (ECU) 18, connected via electrical circuits 19 EGF 17, motor 21 with the crankshaft 22.

The method of testing high-pressure devices of the diesel fuel system on a running engine is as follows. On an idle engine, using a special tool 2, through a feed hose 4 and a return hose 5, connect the device 1 to the fuel return circuit 3 and install the pulse sensor 7 on the EHF circuit 19 of the first or any other cylinder. Through connecting devices 6 TO, connect the diagnostic device with a pulse sensor 7, a high pressure regulator of fuel 8 and PC 9.

The engine 21 of the vehicle is started, the rotational speed of the crankshaft 22 is set equal to the idle speed or any other speed corresponding to the test plan previously stored in the computer memory. In this case, the total flow rate for control and pressure change in the common return line 3 is measured, after synchronization of the total flow rate over the engine operation cycles, the flow balance and the individual flow rate for control of each EGF 17 are determined. If necessary, to increase the information content of the method, set the pressure in the fuel accumulator high pressure regulator 8, using a microcontroller, by means of a PWM signal. The set values of the individual fuel consumption for controlling each EGF 17 are pre-stored in the computer 9. The signals coming from the sensors of the device 1 enter the microcontroller located inside the device 1, which serves to process the signals of the sensors and control the pressure in the measuring channel of the device 1 and communication with PC 9. The results are entered in the electronic test report, in the memory of PC 9.

Upon completion of the tests, based on the processing of the obtained measurement results on a PC, a diagram of the balance of expenses and individual expense for EHF control is displayed. This allows us to make a conclusion about the technical condition of electro-hydraulic nozzles and the need for repair or adjustment work.

The inventive method was tested in the conditions of a motor transport enterprise, for this a prototype of a device for measuring the parameters of fuel movement in a common return line was made, and a series of experiments was conducted aimed at identifying the most informative operating modes of the fuel supply system and device.

The prototype device for measuring the parameters of fuel movement in the common return line contained a housing with a pressure sensor, pressure regulator and fuel flow sensor located inside, combined into one measuring channel, located in series in the return fuel line circuit. Also inside the case was a power supply and a microcontroller. The external connection of the device was provided by rigid hoses for connecting to the return line, an EGF control pulse sensor, a USB bus, for connecting to a PC.

Example 1. On a 4-cylinder engine, operational EHFs were installed, with a fuel consumption of 10 ml / min for idle control.

Measurements were made in the “idle” mode, at a pressure in the automatic transfer tube of 30 MPa and a pressure in the return line of 0.1 MPa, and pressure and fuel consumption indicators in the common return line were obtained. According to the obtained indicators, the values of the pressure pulses at the flow rate for control from the EHF of each cylinder are the same - at the level of 0.5 MPa, the fuel consumption in the common return line is 40 ml / min, which indicates the serviceability of the installed EHF.

Example 2. On a 4-cylinder engine, on the third cylinder, a faulty EGF is installed, with increased fuel consumption for control, in the "idle" mode - 30 ml / min, previously tested on a specialized stand. The measurements were carried out in the “idle” mode, at a pressure in the ADT of 30 MPa and a pressure in the return line of 0.1 MPa, pressure and fuel consumption indicators in the common return line were obtained. According to the obtained indicators, the peak values of the pressure pulses are the same at a control flow from the EHF of the 1st, 2nd, 4th cylinders - at the level of 0.55 MPa, and the third cylinder - 0.3 MPa, the fuel consumption in the common return line is 70 ml / min, which indicates about the EGF malfunction of the third cylinder.

The implementation of this method of testing high-pressure devices of the diesel fuel system with a running engine and a device for its implementation can reduce the time and improve accuracy when diagnosing EGF diesel engines.

Claims (2)

1. A method of testing high-pressure devices of the diesel fuel system on a running engine, namely electro-hydraulic nozzles, including measuring fuel consumption for controlling each nozzle, characterized in that they are connected to a common return line, which allows to determine the components of the balance of fuel consumption in the common return line to based on the measurement and analysis of data on pressure changes and total flow in the common return line, moreover, pressure and flow measurement in the common return line produced using a pressure sensor and a fuel consumption sensor located in series in a common return fuel line. 2. A device for implementing a method for testing high-pressure devices of a diesel fuel system on a running engine, connected to a common return line of electro-hydraulic nozzles, characterized in that it contains a microcontroller, sensors for measuring fuel flow and pressure in a common return line, combined into one measuring channel, made with the ability to connect to the return line, using a connecting bolt fitting, a control pulse sensor for synchronization with the operation of the electric hydra Nozzle-crystal, USB bus for data transfer to a PC.

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