RU2578019C2 - Device for determining characteristics of fuel injection of fuel supply equipment of diesel engines - Google Patents

Abstract

FIELD: engines.

SUBSTANCE: invention relates to propulsion engineering, particularly to devices for testing and adjusting injectors, and can be used plants for production of diesel engine fuel hardware, service centers and servicing stations. Apparatus comprises socket 3 mounted in first pressure sensor 2, line 1, connecting socket 3 and control unit 6, which is mounted in second sensor 8, pressure reducing valve 5 and solenoid valve 7. Control system comprises pulse-width modulator 9, electronic control unit 10, analog-digital converter 11 and monitor 12.

EFFECT: technical result consists in continuous adjustment of signal received from first pressure sensor in socket using a correction factor in proportional to propagation velocity of a pressure wave in pipe in real time.

1 cl, 2 dwg

Description

The invention relates to engine building, in particular to devices for testing and adjusting the fuel supply equipment of diesel engines, and can be used by factories for the production of diesel fuel equipment, in service centers and service stations.

A device is known that makes it possible to investigate the characteristic of fuel supply by diesel nozzles (RF patent No. 2433299, IPC F02M 65/00, published on November 10, 2011, “A device for studying fuel supply by fuel-supplying equipment in diesel engines”), containing a fitting for installing the tested nozzle mounted it has a pressure sensor, a pipeline connecting it to the control unit, in which a pressure reducing valve is mounted.

The disadvantage of the described device is the significant measurement error arising due to changes in the temperature of the fuel during the test, which affects the speed of wave propagation, and therefore, the formation and translation of the pressure curves taken from the pressure sensor in the fitting, in the injection characteristic.

The problem to which the invention is directed is to increase the accuracy of the conversion of the obtained curves to the injection characteristic over the entire range of fuel operating temperatures by automatically adjusting the signal recorded from the first sensor.

The solution to this problem is achieved by the fact that a second pressure sensor is installed in the control unit, which is connected through an analog-to-digital converter with an electronic control unit to record and process the received signals from the first and second pressure sensors in order to determine the travel time and velocity of propagation of the pressure wave in the pipeline in the current time mode to calculate the correction coefficient, which allows you to continuously translate the signal received from the first pressure sensor into the yawing fuel.

In FIG. 1 shows a functional diagram of the device. In FIG. Figure 2 shows the fuel pressure curves in the pipeline, taken from both pressure sensors.

The device comprises a fitting 3 with a receiving chamber, a first pressure sensor 2 mounted therein, a pipe 1 connecting a fitting 3 and a control unit 6 into which a second pressure sensor 8 is mounted, a pressure reducing valve 5 and an electromagnetic valve 7. The control system comprises a pulse-width modulator 9, an electronic control unit 10, an analog-to-digital converter 11, and a monitor 12.

The device operates as follows.

In the initial state, the analog-to-digital converter 11 and the pulse width modulator 9 are turned on and tuned. In the electronic control unit 10, a control program for the process of determining injection characteristics and data processing has been introduced. The test nozzle 4 is installed in the nozzle 3. In this case, the cavities of the nozzle 3, the pipeline 1 and the control unit 6 are filled with fuel.

At the operator’s command, the electronic control unit 10 determines the readiness of the analog-to-digital converter 11 to start the conversion and generates control signals for changing the parameters of the pulse-width modulator 9. When fuel is supplied to the nozzle 4, fuel is injected into the pipeline 1. The injected fuel causes a pressure wave to appear, propagating in the pipeline 1. In this case, the pressure change at the beginning of the pipeline is detected by the first pressure sensor 2 in the form of a pressure curve. Then, the pressure wave that appeared during fuel injection is sent through pipeline 1 to the channel of the control unit 6, where the second pressure sensor 8 also detects the pressure change. The received signals from both sensors are fed through an analog-to-digital converter 11 to an electronic control unit 10 for recording and processing them. The data obtained are processed by the embedded program, and the results are displayed on the monitor 12.

In FIG. Figure 2 shows the fuel pressure curves in the pipeline taken from both pressure sensors. To increase the accuracy of translating these signals into the injection characteristic, the current pressure values obtained from the first sensor are adjusted in proportion to the change in the wave propagation velocity using a coefficient experimentally determined for this device.

The correction factor changes in a function that depends on the speed of wave propagation:

k = f (V)

The correction coefficient k takes into account the velocity of the pressure wave propagating through the pipeline, determined by the beginning of the increase in pressure at the first and second sensors and calculated by the formula:

V = L / Δt,

where L is the distance between the first and second sensor;

Δt is the travel time of the pressure wave from the first to the second sensor, determined by the beginning of the change in pressure in the pipeline recorded by each sensor.

The use of a second pressure sensor will make it possible to determine the change in the velocity of propagation of the pressure wave in the pipeline, calculate the correction factor in the electronic control unit and, on this basis, automatically correct the signals taken from the first pressure sensor when converting them to the injection characteristic displayed on the monitor, which will increase accuracy and reduce the complexity of the measurement process.

Claims (1)

A device for determining the fuel injection characteristics of the diesel engine with fuel supply equipment, comprising a fitting for installing the test nozzle, a first pressure sensor mounted in it, a pipe connecting the fitting with a control unit, into which a pressure reducing valve and an electromagnetic valve are mounted, characterized in that a second is installed in the control unit a pressure sensor, which is connected through an analog-to-digital converter with an electronic control unit, for recording and processing received signals from the first- and second pressure sensors.

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