SU1275236A1 - Device for estimating power of internal combustion engine - Google Patents

Abstract

The invention can be used for testing internal combustion engines under operating conditions and allows for the possibility of determining the power at stationary engine operating conditions. At idle the engine sets the specified rotational speed, controlled by the recorder 3. Tunable bandpass filter 5 regulate the transmission to the recorder 6 of the third and fourth harmonics of the acceleration of the motor shaft, the amplitude of which is recorded. Next, increase the load on the engine and, accordingly, increase its power while maintaining a predetermined rotational speed. In the working mode, the working value of the harmonic amplitude is recorded, and the engine power is determined by the mathematical formula given in the description of the invention. 4 il.

Description

one

The invention relates to a measurement technique and can be used when testing internal combustion engines under operational conditions.

The aim of the invention is to make it possible to determine the power at stationary engine operating conditions.

Figure 1 shows the structural diagram of the device; figure 2 is a graph of the indicator moment M from the angle of rotation of the engine shaft; Figs. 3 are graphs of the components of the acceleration of the motor shaft versus the angle of rotation of the motor shaft; figure 4 - view of the calibration curve. devices1.

The device for determining the power of the internal combustion engine contains a sensor 1 of the marks-angular position of the engine under test, connected through the converter 2 pulse frequency to voltage to the recorder 3 of the shaft rotation speed and to the acceleration calculation unit 4, the output of which is connected via a tunable band-pass filter 5 to the registrar 6.

The basis of the proposed device based on the relationship between the magnitude of the indicator moment M | and an effective power of Ng engine.

The magnitude of the indicator moment M within the operating cycle of the Z-cylinder of the engine varies within very wide limits (figure 2). In this case, the maximum positive value of the indicated moment Mj takes in the range of 20 - 40 ° from BhfT. Moreover, within the specified limits, the dependence of the indicator moment M on the angle of rotation of the shaft is close to sinusoidal and has a frequency of 3 or 4 times greater than the frequency of rotation of the shaft.

At a constant value of the inertial masses, reduced to the motor shaft 1 between the indicated moment Mj and acceleration; crankshaft there is a direct relationship.

Since the indicator M; is the sum of the components: gas, compression and inertia. Then, it corresponds to the acceleration j of the motor shaft, which is the sum of the components (fig.3t); gas (fig o For)

75236 .2

compression (fig.Zy) and inertia (Fig. 38).

In this case, the work of the inertial component of the indicator moment K;

5 during the working cycle is equal to zero, and the operation of the compression component of the indicator torque does not depend on the engine load and is determined by the frequency of rotation of the engine shaft.

О Thus, at a given speed mode, the engine power is determined by the gas component of the indicator moment, the maximum of which is at the angular position

5 shaft ranging from 20 to 40 from TDC. With increasing engine power at a constant speed, the amplitude of the gas component of the indicator moment M increases, and, accordingly, the amplitude of the gas component of the engine shaft acceleration within the operating cycle, i.e. by the amplitude of three or four harmonics of the acceleration of the motor shaft can be judged

25 about the power developed by him at a given frequency of rotation.

A device for determining the power of an internal combustion engine operates as follows.

30 Idling the engine, set the specified rotational speed, which is controlled by the recorder 3, the tunable band-pass filter 5 is controlled by

35 transmission to the recorder 6 of the third or fourth harmonics of the acceleration of the motor shaft, the amplitude of which A is recorded and stored.

Further, the engine load is increased and, accordingly, its power is increased while maintaining the specified rotational speed. When the operating mode is reached, the operating value of the accelerator harmonic of the accelerator 45 and Ap is recorded, and the engine power is determined by

N K. -f ---,

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Claims (1)

5 where K is the grading factor. For unbalanced motors, due to the influence of the inertial component, the dependence of a mlith of these harmonics on the power is nonlinear. In this case, 55, the engine mark of the engine must be traded (reference) with the help of the brake bench (figure 4). 312 claims An apparatus for determining the power of an internal combustion engine, comprising an engine crankshaft angle mark sensor connected via a pulse-to-voltage frequency converter to an acceleration calculator. 364 so that, in order to make it possible to determine the power at stationary engine operating conditions, a tunable band-pass filter is inserted in it that is connected between the acceleration calculator and the recorder, as well as an additional recorder connected to the output of the impex following frequency converter TO ISO / u, /   AW 10 20NW CPILZ.