SU1239540A1 - Bed for testing internal combustion engine - Google Patents

Abstract

The invention relates to the field of engine construction, namely, automated bench test systems, and allows an increase in the accuracy of measuring the power of an internal combustion engine. The test bench contains a load device, a rotational speed sensor, a mechanical support meter, multipliers, a rotor current meter, a recorder, adders, a scaling block, a quad, a differentiation unit, a temperature deviation sensor for an electric machine, and a single signal source. The stand scheme allows taking into account the mechanical losses, the losses from heating the windings of the electrical maschine, which is the load device, during its operation when measuring the power on the motor shaft, while dynamically the loads occurring in transient speeds are also taken into account. 1 il.

Description

The invention relates to engine building, in particular to testing of internal combustion engine engines, namely, automated bench test systems.

The purpose of the invention is to improve the accuracy of measuring the power of an internal combustion engine.

The drawing shows a block diagram of a test bench for an internal combustion engine.

The stand contains a load device 1, made in the form of an asynchronous electric machine with a phase-rotor and connected to the shaft of an internal combustion engine 2 and also connected to the rotational speed sensor 3. The output of the rotational speed sensor 3 is connected to the inputs of the mechanical loss meter 4 and the differentiation unit 5, as well as to the first input of the first multiplication unit 6 i. The output of the mechanical loss meter 4 is connected to the first input of the second adder 7, and the output of the differentiation unit 5 through the first scaling unit 8 is connected to the second input of the third adder 7. The output of the latter is connected to the second input of the first multiplication unit 6, the output of which is connected with the first input of the first adder 9. The output of the adder 9 is connected to the registering device 10. The output of the meter 11 is the sum of the direct and inverse symmetrical components of the mains voltage connected to the second input of the second multiplication unit 12, the output of which is connected to the third input of the second adder 7. The rotor circuit of the electric machine 1 includes a current meter 13, the output of which is connected to the first input of the second multiplication unit 12 and the quad input 14. The output of the latter through the second scaling unit 15 is connected to the first input of the third block 16 intelligently, and the output of multiplier 16 is connected to the second input of the first adder 9. A source 17 of a single signal is connected to the first input of the third cz mmator 18, the output of which is connected to the second input of the third multiplication unit 16. A temperature deviation sensor 19 is mounted on the stator of the electric machine 1 and is connected through the third scaling unit 20 to the second input of the third adder 18.

The scheme works as follows.

When testing the engine 2 internal combustion electric machine 1 operates in the generator mode. The alternating voltage to the electric machine 1 is supplied from the phases Q, 6, c. the sum of the direct and inverse symmetric components of this voltage is determined by means of a meter 11 a

ten

395402

the rotor current is determined by the meter 13. The signals from the meters 11 and 13 are fed to the inputs of the multiplication unit 12, from whose output to the input of the second adder 7 a signal proportional in magnitude to the torque on the shaft of the electric machine is installed. The sensor 3 generates an electrical signal corresponding to the rotational speed of the engine and fed to the inputs of the mechanical loss meter 4 and the differentiation unit 5. The output signals of blocks 4 and 5 are fed to the inputs of the second adder a 7, and from block 4 the signal goes directly, the asblock 5 through the block. 8 scaling.

From the output of the second adder 7, the signal enters the second multiplication unit 6, the second input of which receives the signal from the rotation speed sensor 3.

As a result of the operations performed at the output of the second multiplier block 6, the signal corresponds to the power of the internal combustion engine, taking into account mechanical losses in established and transient high-speed modes of operation, but excluding electrical losses in copper.

15

20

25

To account for these losses, the signal is measurable; The rotor current 13 is also fed to the input of the quad 14, and from the last output passes through the second scaling unit 15 to the first input of the third multiplication unit 16, the second input of which receives a signal from the output of the third adder 18, summing the signals of the unit 17 signal and the signal c a temperature deviation sensor 19 supplied to the input of the adder via the third scaling unit 20. The signals from the outputs of blocks 6 and 16 are fed to the inputs of the first adder 9 and from it to the recording device.

Thus, the described stand scheme implements the expression

(u

.duJ.

lr

J. ) i - nn

.3, (1 - “- o (at),

Where

3

five

uJ to a oSpM "pJ -

R signal proportional to the engine power; shaft rotation frequency; coefficient; rotor current;

direct and reverse feed voltage components; mechanical losses; moment of inertia; . winding resistance at nominal temperature;

o (- temperature coefficient; dt - increment of the temperature of the windings of the electric machine,

and allows to take into account when measuring the power on the shaft 1, the internal h-motor, both asymmetrically applied voltage of the electric machine, mechanical losses, and psggeri, caused by heating the windings of the electric machine during its operation, by measuring the dynamic loads that occur in transient speeds.

Claims (1)

Invention Formula A test bench for testing an internal combustion engine containing a load device, a rotational speed sensor, a mechanical loss meter, first and second multipliers, a rotor current meter and a recorder, the load unit made in the form of an electric motor with a phase rotor and connected to the shaft connected with a frequency sensor connected to a mechanical loss meter and the first input of the second multiplication unit, a sum and forward sum of the symmetrical components of the supply network Whose output is connected to the WTO {Second input and 1M} gmnozheni unit, characterized in that, in order to increase 5404 Accuracy of measuring the power of the ntiyr-early combustion engines, the stenz additionally contains the first, second and third adders, the third multiplication unit, the first, second and third scaling units, the quad, the differential unit, the temperature deviation sensor of the electric machine and the source of a single signal, the output of the mechanical meter loss connected to the first input of the second adder, the input of the differentiation unit is connected to the output of the rotational speed sensor, and the output is through the first scaling unit to the second input of the second adder, the output of the second multiplication unit is connected to the third input of the second adder, the output of which is connected to the mountain of multiplication, the first input of the first adder is connected to the output of the first multiplication unit, the second input is connected to the output of the third multiplication unit, and the output is connected to the recorder, the input of the quadrator is connected to the first input of the second multiplication unit, and the output through the second mass stabilization unit is connected with the first input of the third multiplication unit, the source of the single signal is connected to the first input of the third adder, and the temperature deviation sensor of the electric machine through the third scaling unit is connected with the input of the third adder, the output of which is connected to the second input of the third multiplier unit . - “SJ tf a Lrl th: a oO-06 (Editor H. Dumb Compiled by P. Filippov Tehred I.Popovich Order 3386/40 Circulation 778 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. General Design, 4 Proofreader Sharoshi