RU130005U1 - DEVICE FOR DIAGNOSTIC OF DIESEL SYSTEMS - Google Patents

Abstract

A device for diagnosing diesel systems, containing the base of the stand, on which the tested high pressure fuel pump (TNVD) is located, nozzles, graduated cylinders, fuel distributor, upper and lower fuel tanks, booster pump, fuel filter, pressure gauge damper, pressure gauge, fuel cylinder through which the high pressure fuel lines (HPT) pass, moreover, the fuel cylinder is connected to the high pressure accumulator of the fuel and to the damper of hydraulic vibrations of the fuel in the cylinder, on the test shaft of the injection pump, a disk is installed with a permanent magnet for controlling the opening of the damper damper for hydraulic vibrations of fuel and a permanent magnet of the top dead center marker (TDC) of the first cylinder, an electric circuit for detecting changes in fuel pressure in a fuel engine, containing a fuel pressure sensor located in the fuel cylinder and connected a switch and electrical circuits with a current amplifier, analog-to-digital converter (ADC), a port and a computer, the computer being connected to the display, electrically a circuit of the TDC marker of the first cylinder, comprising an electric coil located on the high pressure fuel pump housing and connected through an electric circuit to an electric unit; an electric control circuit for the spool of the fuel cylinder with a damper for hydraulic vibrations of fuel, consisting of an electric coil mounted on the injection pump housing, a DC amplifier and an electric coil for the spool of the fuel cylinder with a damper for hydraulic vibrations of fuel, a current sensor mounted on a wire

Description

The utility model relates to devices for measuring the parameters of the power system and the diesel electric starter starting system and can be used to diagnose fuel equipment, starter and starter circuit.

A device for diagnosing diesel fuel equipment (patent RU No. 2293206, IPC F02M 65/00 dated 02.10.2007) containing a stand base, on which the tested high pressure fuel pump (TNVD) is located, nozzles, graduated cylinders, distributor fuel, upper and lower fuel tanks, booster booster pump, fuel filter, pressure gauge damper, pressure gauge, fuel cylinder through which the high pressure fuel lines (HPT) pass, and the fuel cylinder is connected to the high pressure accumulator then a cylinder with a damper for hydraulic vibrations of the fuel in the cylinder, and a disk with a permanent magnet for controlling the opening of the damper of the damper for hydraulic vibrations of the fuel and a permanent magnet of the top dead center marker (TDC) of the first cylinder is mounted on the shaft of the test pump; A fuel engine containing a fuel pressure sensor located in the fuel cylinder and connected by a switch and electric circuits to a current amplifier, an analog-to-digital converter it (ADC), port and computer, moreover, the computer is connected to the display; an electric circuit of the TDC marker of the first cylinder, comprising an electric coil located on the high pressure fuel pump housing and connected through an electric circuit to an electric unit; an electric control circuit for the spool of the fuel cylinder with the damper of hydraulic vibrations of the fuel, consisting of an electric coil mounted on the injection pump housing, a direct current amplifier and an electric coil of the spool of the fuel cylinder with the damper of hydraulic vibrations of the fuel, interconnected by an electric circuit.

The disadvantage of this device is the small number of diagnosed parameters of the diesel engine, affecting its performance.

For diagnosing fuel equipment, starter and starter circuit, a device for diagnosing diesel systems is used (patent RU No. 2370745, МГЖ G01M 15/04, F02M 65/00 published: 20.10.2009), containing the base of the test bench, on which the tested high-pressure fuel pump is placed (TNVD), nozzles, graduated cylinders, a fuel distributor, upper and lower fuel tanks, a booster pump, a fuel filter, a pressure gauge damper, a pressure gauge, a fuel cylinder through which high-pressure fuel lines pass, and the second cylinder is connected to the fuel high-pressure accumulator and to the damper of the hydraulic vibrations of the fuel in the cylinder, and a disk with a permanent magnet for controlling the opening of the damper of the damper of the hydraulic vibrations of the fuel and a permanent magnet of the top dead center marker (TDC) of the first cylinder is mounted on the shaft of the tested high pressure fuel pump an electric circuit for detecting changes in fuel pressure in a fuel engine containing a fuel pressure sensor located in the fuel cylinder and connected by a switch and electric circuits with a current amplifier, analog-to-digital converter (ADC), a port and a computer, the computer being connected to the display; an electric circuit of the TDC marker of the first cylinder, containing an electric coil located on the injection pump housing and connected via an electric circuit to the electric unit, an electric control circuit for controlling the spool of the fuel cylinder with a hydraulic vibration damper, consisting of an electric coil fixed to the TNVD housing, a DC amplifier and an electric coil of the spool of the fuel cylinder with a damper of hydraulic vibrations of the fuel, interconnected chain, a DC voltmeter connected in parallel with the vehicle’s battery, and an ammeter with a current sensor mounted on a wire connecting the positive terminal of the battery to the starter and clasping it with its clamps, are fixed to the base of the stand.

The disadvantage of this device is the small number of diagnosed engine parameters that affect its performance, as well as the complexity of the work performed when determining these characteristics.

The technical result of the claimed utility model is to expand the functionality of the device, as well as the automation of calculation and indication of characteristics.

The specified technical result is achieved by the fact that the device for diagnosing a diesel engine containing the stand base, on which the tested high pressure fuel pump (TNVD), nozzles, graduated cylinders, fuel distributor, upper and lower fuel tanks, booster booster pump, fuel filter, damper are located pressure gauge, pressure gauge, fuel cylinder through which high pressure fuel lines (HPT) pass, moreover, the fuel cylinder is connected to the high pressure fuel accumulator and to the hydraulic damper In the case of fuel oscillations in the cylinder, a disk with a permanent magnet for controlling the opening of the damper of the hydraulic oil vibration damper and a permanent magnet of the top dead center marker (TDC) of the first cylinder is mounted on the shaft of the tested high-pressure fuel pump; an electric circuit for detecting changes in fuel pressure in the fuel engine containing a pressure sensor fuel, located in the fuel cylinder and connected by a switch and electric circuits with a current amplifier, analog-to-digital converter (ADC), port and computer, etc. whereby the computer is connected to the display, the electric circuit of the TDC marker of the first cylinder, containing an electric coil placed on the fuel pump housing and connected via an electric circuit to the electric unit, an electric control circuit for controlling the spool of the fuel cylinder with the hydraulic vibration damper, consisting of an electric coil fixed to the casing of the injection pump, a direct current amplifier and an electric coil of the spool of the fuel cylinder message with a damper for hydraulic vibrations of the fuel a current sensor installed on a wire connecting the positive terminal of the battery to the starter, interconnected by an electric circuit, according to the claimed technical solution, the device is additionally equipped with a computing unit based on a digital microcontroller with integrated ADC, one input of which is connected to the signal output of the current sensor, and the second is connected in parallel to the battery, a liquid crystal display (LCD), the inputs of which are connected to the outputs of the microcontroller, stabilized by the power supply Coupled circuits with the current sensor and a microcontroller.

The device is illustrated by drawings, where Figs. 1 and 2 show a device for diagnosing diesel systems, Fig. 3 is a diagram of a change in fuel pressure in a theater, depending on the angle of rotation of the camshaft.

A device for diagnosing diesel systems contains the base of stand 1, on which the test pump 2 is located, nozzles 3, graduated cylinders 4, a fuel distributor 5, upper 6 and lower 7 fuel tanks, a booster pump 8, a fuel filter 9, a pressure gauge damper 10, a pressure gauge 11 , the fuel cylinder 12, through which the theater 13 passes, is connected by a pipe 14 to a high-pressure fuel accumulator 15, and a pipe 16 is connected to a hydraulic vibration damper of the fuel 17 in the cylinder 12. The hydraulic vibration damper of the fuel 17 is made in the form of a joint a, connected by a pipe 16 to the fuel cylinder 12 through an opening 18 made in the spool 19, which is designed to communicate the hydraulic vibration damper 17 with the fuel cylinder 12 at intervals between the fuel supplies by separate sections of the injection pump 2. A return valve is placed in the housing 20 above the spool 19 spring 21, an electric coil 22 is installed over the other part of the spool 19, forming a solenoid. The electric coil 22 of the solenoid is connected by electric lines 23 and 24 through a DC rectifier 25 to an electric coil 26 mounted on the front of the injection pump 2. At the front end of the cam shaft 27 of the injection pump 2, a movable disk 28 is mounted together with four permanent magnets 29 mounted on it. Strain gauge the fuel pressure sensor 30, located in the fuel cylinder 12, is connected by electric circuits 31, 32, 33 and 34 to a current amplifier 35, an ADC 36, a port 37, a computer 38 and a display 39. The TDC meter of the first cylinder, consisting of electric ctric coil, connected by electric circuits 40, 32, 33 and 34 to ADC 36, port 37, computer 38 and display 39. All electrical circuits are switched on using switch 41. A current sensor 43, in which the Hall effect is used, is mounted on a wire connecting the positive terminal of the battery 44 with the starter 45. A digital microcontroller 46 with an integrated ADC, one input of which is connected to the signal output of the current sensor 43, and the second is connected in parallel with the battery 44, a liquid crystal display (LCD) 47, the inputs of which are connected to the output odes of the microcontroller. A stabilized power supply 48, connected by electrical circuits to a current sensor 43 and a microcontroller 46.

The fuel high-pressure accumulator 15 is designed to maintain an excess fuel pressure of 150 MPa in the fuel cylinder 12. This amount of excess pressure eliminates both erosive destruction of the outer surfaces of the theater 13 due to the elimination of the occurrence of cavitation, and to increase the response speed of the electric circuit for registering pressure in the theater.

For a four-cylinder four-stroke diesel engine, the angles ϕ ₁ , ϕ ₂ , ϕ ₃ , ϕ ₄ between the permanent magnets 29 are 20 ° of the camshaft rotation, since it is known that the duration of the full supply of diesel engines does not exceed 40 ° of the crankshaft rotation or 20 ° of the camshaft rotation. Angles ϕ ₅ , ϕ ₆ , ϕ ₇ , ϕ ₈ are 70 ° of rotation of the camshaft. This value corresponds to the rotation angles of the camshaft of the injection pump 2 in the intervals between the fuel supply to the nozzles 3 by separate sections of the injection pump 2.

A device for diagnosing diesel systems operates in two modes: a diagnostic mode for starting diesel indicators and a diagnostic mode for fuel equipment.

A control program is recorded in the memory of the microcontroller. The initial data for the production of calculations using this program are analog signals from the current sensor and battery terminals, proportional to the values, respectively, of the discharge current and battery voltage. The incoming signals are digitized and their instantaneous values are used to determine the characteristics of the diesel electric start system. During the operation of the first operating mode, when the device is connected and in the absence of current in the circuit, the EMF of the battery 44 is determined. At the moment the car starter is turned on when the diesel engine is started, the starting current flows in the circuit and the program switches to calculation mode. When the starter is turned off, the program enters the data output mode on the screen. The calculated characteristics are displayed on the LCD. The calculations are performed at high speed in real time, without delays in processing the received information. The proposed model during the first mode performs the following functions:

- determination of electrical energy spent on launch;

- determination of the amount of electricity given by a chemical energy source to the load at startup, i.e. battery discharge;

- determination of the maximum power developed by the starter at startup;

- determination of the internal resistance of the battery;

- determination of the resistance of the starter;

- determination of the minimum voltage value of the energy source under load;

- determination of the maximum value of the starting current;

- determination of discharge time.

During the second mode of operation, fuel is supplied to the injection pump 2 from the lower fuel tank 7 through the fuel distributor 5 and the fuel filter 9 using the fuel priming pump 8. The injection pump 2 delivers the fuel to the nozzles 3 under high pressure via the high pressure fuel pump 13. To diagnose the technical condition of the injection pump 2 , nozzles 3 and high pressure fuel pump 13, it is necessary to close the contacts of the switch 41. In this case, the electric control circuits of the control valve of the message of the fuel cylinder 12 with the damper of hydraulic vibrations of the fuel 17 will work, registration of pressure changes I have fuel in the theater 13 and the TDC meter of the first cylinder. The electrical control circuit for the control valve of the fuel cylinder 12 with the damper of the hydraulic vibrations of the fuel 17 operates as follows: when the fuel flows through the fuel assembly 13 with a variable pressure, they are subject to vibrations that are transmitted to the fuel in the fuel cylinder 12. Under the influence of vibrations of the fuel assembly 13 in the fuel wave phenomena that adversely affect the operation of the fuel pressure sensor 30. This occurs due to the occurrence of resonance during the addition of oscillations caused by vibrations of the fuel assembly 13, according to which th fuel is supplied to the injectors. When the movable disk 28 is rotated by an angle of 45 °, the permanent magnet 29 moves at the turns of the electric coil 26, in which an electric current occurs. The electric current through the electric circuits 24 and 23 through the current amplifier enters the electric coil 22. Under the influence of the electric field arising in the coil 22, the spool 19 moves to the left, compressing the return spring 21. In this case, the hole 18 in the spool 19 is aligned with the hole of the pipe 16. In this case, part of the fuel from the fuel cylinder 12 will flow into the ball 17, in which there is air. Due to the periodic compression of the air in the ball 17, the wave oscillations in the cylinder 12 are rapidly damped. When the cam shaft is rotated through the angles ϕ ₁ , ϕ ₃ , ϕ ₄ and ϕ ₂ , fuel is supplied to the first, third, second, and fourth sections of the high-pressure fuel pump 2 and to the first , third, second and fourth nozzles, respectively. At the same time, the hydraulic vibration damper 17 does not work. At intervals corresponding to the angles ϕ ₅ , ϕ ₆ , ϕ ₇ and ϕ ₈ , the ball 17 communicates through the hole 18 in the spool 19 with the fuel cylinder 12, in which the hydraulic oscillations in the fuel are damped.

Thus, the damping of wave phenomena arising in the fuel cylinder 12 due to vibrations of the fuel assembly 13 occurs in the time intervals between the fuel supply of the injection pump 2 to the nozzles 3.

The principle of operation of the electrical circuit for detecting changes in fuel pressure in the fuel assembly 13 is that the pressure change is recorded by the fuel pressure sensor 30, the electrical signal supplied to the sensor 30 is amplified by a current amplifier 35 and fed to the ADC 36, which converts the analog signal to its corresponding code . This code through port 37 enters the computer 38, the output of which is connected to the display 39, which displays information about the change in fuel pressure in the theater 13.

When the camshaft 27 of the injection pump 2 rotates, the fuel is pumped in sections under high pressure in the order of the diesel cylinders through the theater 13 to the nozzles 3. When the fuel flows through the section of the theater 13 located in the fuel cylinder 12, the fuel pressure pulse is transmitted through the walls of the theater 13 and fuel, being under pressure of 150 MPa in the fuel cylinder 12, to the pressure sensor 30, from which the electric signal is supplied through the electric circuit 31 to the current amplifier 35 and ADC 36. The accuracy of the registration of the fuel supply process is determined by the amplitude-frequency and the characteristics of measuring instruments, by which is generally understood transformation ratio signal dependent on the frequency. The idea of the necessary frequency spectrum describing the processes in the fuel equipment with a given accuracy can be obtained on the basis of triangular and rectangular pulses, the shape of which is close to the oscillograms of the processes studied in the fuel equipment (for example, the curve of the change in fuel injection pressure depending on the angle of rotation of the cam shaft Injection pump 2).

The limits of the necessary spectrum can be established by the example of the analysis of a triangular impulse described by a function in the form of a series:

where A ₀ is the value of the input signal;

a is the wavelength of the input signal;

k is the order of the considered harmonic.

When registering the fuel supply process with steep fronts, the necessary spectrum can be determined by the magnitude of the phase shift caused by the fact that the amplitude of the transmission pulse does not reach the nominal value immediately, but after some period ϕ _n , which is usually called the rise time. The largest increase in the fuel supply front is observed for pulses approaching rectangular in shape, and is described by the following expression in the form of a series:

The signal from the ADC 36 is supplied through electric circuits 32, 33 and 34 to port 37, computer 38 and to the display 39 as a graphical representation of the change in fuel pressure in the fuel assembly 13 from the angle of rotation of the camshaft of the injection pump 2 (Fig. 3). In the case of fuel supply by the first section of the injection pump 2, the electric circuit of the TDC marker of the first cylinder is triggered, since when the permanent magnet 39 moves near the electric coil 42, a magnetic flux Φ occurs in the gap between these parts, and at some point in time τ it reaches a maximum, and then decreases. In accordance with the change in magnetic flux, the magnitude of the EMF created in the coil 42, determined by the formula:

между которыми кривая ЭДС проходит через ВМТ.In accordance with expression (4), the EMF reaches its maximum value at maximum

between which the EMF curve passes through the TDC.

The electric pulse from the electric coil 42 is transmitted through electrical circuits 40, 32, 33 and 34 to the display 39 in the form of a pulse 8 (figure 3). On the diagram of the change in pressure of fuel injection into the engine cylinders, depending on the angle of rotation of the camshaft (Fig. 3), point 1 corresponds to the beginning of the pressure increase coinciding with the rise of the discharge valve. At point 2, the fuel pressure reaches a value at which the torque of the nozzle spring is overcome, the needle breaks away from its seat and injection occurs. In section 3-4, there is a decrease in the rate of increase in injection pressure due to an increase in the volume in the atomizer when the nozzle needle is raised. At point 5, the injection pressure reaches its maximum value. Point 6 corresponds to the moment the nozzle needle fits into the saddle, and at point 7 the pressure valve fits into the saddle.

The diagram shows, as an example, measurements of fuel injection into cylinders in one working cycle of a four-stroke four-cylinder diesel engine. These diagrams can be compared with reference design diagrams and determine malfunctions in the operation of the injection pump sections and nozzles both on the stand and on the engine mounted on the stand or on the vehicle. For example, figure 3 shows that the injection pump section of the third cylinder has low pressures at points 1 and 7, which indicates a loose fit of the discharge valve in the seat and wear of the plunger pair. The section of the fourth cylinder has an insufficient tightening of the nozzle needle spring, which therefore rises earlier. The pressure at point 5 of this section does not reach the maximum value. This will lead to a deterioration in atomization of the fuel in the combustion chamber and to a deterioration in the flow of the combustion process.

The volume of fuel injected by the nozzles 3 (figure 1) is determined using graduated cylinders 4.

Thus, a device for diagnosing diesel systems in the modes of diagnosing diesel start-up indicators and diagnosing fuel equipment measures the electric energy spent on starting, the amount of electricity supplied by the chemical energy source to the load at startup, the maximum power developed by the starter at startup, the internal resistance of the battery, the resistance of the starter circuit, the minimum voltage value of the energy source under load, the maximum value of the starting current, in emya run, check that the fuel injection equipment. The number of monitored parameters is expanded, the determination of characteristics is carried out automatically.

Claims (1)

A device for diagnosing diesel systems, containing the base of the stand, on which the tested high pressure fuel pump (TNVD) is located, nozzles, graduated cylinders, fuel distributor, upper and lower fuel tanks, booster pump, fuel filter, pressure gauge damper, pressure gauge, fuel cylinder through which the high pressure fuel lines (HPT) pass, moreover, the fuel cylinder is connected to the high pressure accumulator of the fuel and to the damper of hydraulic vibrations of the fuel in the cylinder, on the test shaft of the injection pump, a disk is installed with a permanent magnet for controlling the opening of the damper damper for hydraulic vibrations of fuel and a permanent magnet of the top dead center marker (TDC) of the first cylinder, an electric circuit for detecting changes in fuel pressure in a fuel engine, containing a fuel pressure sensor located in the fuel cylinder and connected a switch and electrical circuits with a current amplifier, analog-to-digital converter (ADC), a port and a computer, the computer being connected to the display, electrically a circuit of the TDC marker of the first cylinder, comprising an electric coil located on the high pressure fuel pump housing and connected through an electric circuit to an electric unit; an electric control circuit for the spool of a fuel cylinder with a damper for hydraulic vibrations of fuel, consisting of an electric coil mounted on the injection pump housing, a direct current amplifier and an electric coil for a spool of a message of a fuel cylinder with a damper for hydraulic vibrations of fuel, a current sensor mounted on a wire connecting the battery positive lead batteries with a starter interconnected by an electric circuit, characterized in that in the design of the device conducted: a computing unit based on a digital microcontroller with an integrated ADC, one input of which is connected to the signal output of the current sensor, and the second is connected in parallel with the battery, a liquid crystal indicator, the inputs of which are connected to the outputs of the microcontroller, a stabilized power supply connected by electrical circuits to the current sensor and the microcontroller .

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